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357 ]>
358
359 <specification label="JVM(TM) Tool Interface">
360 <title subtitle="Version">
361 <tm>JVM</tm> Tool Interface
362 </title>
363
364 <intro id="whatIs" label="What is the JVM Tool Interface?">
365 The <tm>JVM</tm> Tool Interface (<jvmti/>)
366 is a programming interface used by development and monitoring tools.
367 It provides both a way to inspect the state and
368 to control the execution of applications running in the
369 <tm>Java</tm> virtual machine (VM).
370 <p/>
371 <jvmti/> is intended to provide a VM interface for the full breadth of tools
372 that need access to VM state, including but not limited to: profiling,
373 debugging, monitoring, thread analysis, and coverage analysis tools.
374 <p/>
375 <jvmti/> may not be available in all implementations of the <tm>Java</tm> virtual
376 machine.
377 <p/>
378 <jvmti/> is a two-way interface.
379 A client of <jvmti/>, hereafter called an <i>agent</i>,
380 can be notified of
381 interesting occurrences through <internallink id="EventSection">events</internallink>.
382 <jvmti/>
383 can query and control the application through many
384 <internallink id="FunctionSection">functions</internallink>,
385 either in response to events or
386 independent of them.
387 <p/>
388 Agents run in the same process with and communicate directly with
389 the virtual machine executing
390 the application being examined. This communication is
391 through a native interface (<jvmti/>). The native in-process interface allows
392 maximal control with minimal intrusion on the part of a tool.
393 Typically, agents are relatively compact. They can be controlled
394 by a separate process which implements the bulk of a tool's
395 function without interfering with the target application's normal execution.
396 </intro>
397
398 <intro id="architecture" label="Architecture">
399 Tools can be written directly to <jvmti/> or indirectly
400 through higher level interfaces.
401 The Java Platform Debugger Architecture includes <jvmti/>, but also
402 contains higher-level, out-of-process debugger interfaces. The higher-level
403 interfaces are more appropriate than <jvmti/> for many tools.
404 For more information on the Java Platform Debugger Architecture,
405 see the
406 <externallink id="jpda/architecture.html">Java
407 Platform Debugger Architecture website</externallink>.
408 </intro>
409
410 <intro id="writingAgents" label="Writing Agents">
411 Agents can be written in any native language that supports C
412 language calling conventions and C or C++
413 definitions.
414 <p/>
415 The function, event, data type, and constant definitions needed for
416 using <jvmti/> are defined in the include file <code>jvmti.h</code>.
417 To use these definitions add the <tm>J2SE</tm> include directory
418 to your include path and add
419 <example>
420 #include <jvmti.h>
421 </example>
422 to your source code.
423 </intro>
424
425 <intro id="deployingAgents" label="Deploying Agents">
426 An agent is deployed in a platform specific manner but is typically the
427 platform equivalent of a dynamic library. On the <tm>Windows</tm> operating
428 system, for example, an agent library is a "Dynamic Linked Library" (DLL).
429 On <tm>Linux</tm> Operating Environment, an agent library is a shared object
430 (<code>.so</code> file).
431 <p/>
432
433 An agent may be started at VM startup by specifying the agent library
434 name using a <internallink id="starting">command line option</internallink>.
435 Some implementations may support a mechanism to <internallink id="onattach">
436 start agents</internallink> in the live <functionlink id="GetPhase">phase</functionlink>.
437 The details of how this is initiated are implementation specific.
438 </intro>
439
440 <intro id="entryPoint" label="Statically Linked Agents (since version 1.2.3)">
441
442 A native JVMTI Agent may be <i>statically linked</i> with the VM.
443 The manner in which the library and VM image are combined is
444 implementation-dependent.
445 An agent L whose image has been combined with the VM is defined as
446 <i>statically linked</i> if and only if the agent exports a function
447 called Agent_OnLoad_L.
448 <p/>
449 If a <i>statically linked</i> agent L exports a function called
450 Agent_OnLoad_L and a function called Agent_OnLoad, the Agent_OnLoad
451 function will be ignored.
452 If an agent L is <i>statically linked</i>, an Agent_OnLoad_L
453 function will be invoked with the same arguments and expected return
454 value as specified for the Agent_OnLoad function.
455 An agent L that is <i>statically linked</i> will prohibit an agent of
456 the same name from being loaded dynamically.
457 <p/>
458 The VM will invoke the Agent_OnUnload_L function of the agent, if such
459 a function is exported, at the same point during VM execution as it would
460 have called the dynamic entry point Agent_OnUnLoad. A statically loaded
461 agent cannot be unloaded. The Agent_OnUnload_L function will still be
462 called to do any other agent shutdown related tasks.
463 If a <i>statically linked</i> agent L exports a function called
464 Agent_OnUnLoad_L and a function called Agent_OnUnLoad, the Agent_OnUnLoad
465 function will be ignored.
466 <p/>
467 If an agent L is <i>statically linked</i>, an Agent_OnAttach_L function
468 will be invoked with the same arguments and expected return value as
469 specified for the Agent_OnAttach function.
470 If a <i>statically linked</i> agent L exports a function called
471 Agent_OnAttach_L and a function called Agent_OnAttach, the Agent_OnAttach
472 function will be ignored.
473 </intro>
474
475 <intro id="starting" label="Agent Command Line Options">
476 The term "command-line option" is used below to
477 mean options supplied in the <code>JavaVMInitArgs</code> argument
478 to the <code>JNI_CreateJavaVM</code> function of the JNI
479 Invocation API.
480 <p/>
481 One of the two following
482 command-line options is used on VM startup to
483 properly load and run agents.
484 These arguments identify the library containing
485 the agent as well as an options
486 string to be passed in at startup.
487 <dl>
488 <dt><code>-agentlib:</code><i><agent-lib-name></i><code>=</code><i><options></i></dt>
489 <dd>
490 The name following <code>-agentlib:</code> is the name of the
491 library to load. Lookup of the library, both its full name and location,
492 proceeds in a platform-specific manner.
493 Typically, the <i><agent-lib-name></i> is expanded to an
494 operating system specific file name.
495 The <i><options></i> will be passed to the agent on start-up.
496 For example, if the option
497 <code>-agentlib:foo=opt1,opt2</code> is specified, the VM will attempt to
498 load the shared library <code>foo.dll</code> from the system <code>PATH</code>
499 under <tm>Windows</tm> or <code>libfoo.so</code> from the
500 <code>LD_LIBRARY_PATH</code> under <tm>Linux</tm>.
501 If the agent library is statically linked into the executable
502 then no actual loading takes place.
503 <p/>
504 </dd>
505 <dt><code>-agentpath:</code><i><path-to-agent></i><code>=</code><i><options></i></dt>
506 <dd>
507 The path following <code>-agentpath:</code> is the absolute path from which
508 to load the library.
509 No library name expansion will occur.
510 The <i><options></i> will be passed to the agent on start-up.
511 For example, if the option
512 <code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code> is specified, the VM will attempt to
513 load the shared library <code>c:\myLibs\foo.dll</code>. If the agent
514 library is statically linked into the executable
515 then no actual loading takes place.
516 <p/>
517 </dd>
518 </dl>
519 For a dynamic shared library agent, the start-up routine
520 <internallink id="onload"><code>Agent_OnLoad</code></internallink>
521 in the library will be invoked. If the agent library is statically linked
522 into the executable then the system will attempt to invoke the
523 <code>Agent_OnLoad_<agent-lib-name></code> entry point where
524 <agent-lib-name> is the basename of the
525 agent. In the above example <code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code>,
526 the system will attempt to find and call the <code>Agent_OnLoad_foo</code> start-up routine.
527 <p/>
528 Libraries loaded with <code>-agentlib:</code> or <code>-agentpath:</code>
529 will be searched for JNI native method implementations to facilitate the
530 use of Java programming language code in tools, as is needed for
531 <internallink id="bci">bytecode instrumentation</internallink>.
532 <p/>
533 The agent libraries will be searched after all other libraries have been
534 searched (agents wishing to override or intercept the native method
535 implementations of non-agent methods can use the
536 <eventlink id="NativeMethodBind">NativeMethodBind event</eventlink>).
537 <p/>
538 These switches do the above and nothing more - they do not change the
539 state of the VM or <jvmti/>. No command line options are needed
540 to enable <jvmti/>
541 or aspects of <jvmti/>, this is handled programmatically
542 by the use of
543 <internallink id="capability">capabilities</internallink>.
544 </intro>
545
546 <intro id="startup" label="Agent Start-Up">
547 The VM starts each agent by invoking a start-up function.
548 If the agent is started in the <code>OnLoad</code>
549 <functionlink id="GetPhase">phase</functionlink> the function
550 <internallink id="onload"><code>Agent_OnLoad</code></internallink>
551 or <internallink id="onload"><code>Agent_OnLoad_L</code></internallink>
552 for statically linked agents will be invoked.
553 If the agent is started in the live
554 <functionlink id="GetPhase">phase</functionlink> the function
555 <internallink id="onattach"><code>Agent_OnAttach</code></internallink>
556 or <internallink id="onattach"><code>Agent_OnAttach_L</code></internallink>
557 for statically linked agents will be invoked.
558 Exactly one call to a start-up function is made per agent.
559 </intro>
560
561 <intro id="onload" label="Agent Start-Up (OnLoad phase)">
562 If an agent is started during the <code>OnLoad</code> phase then its
563 agent library must export a start-up function with the following prototype:
564 <example>
565 JNIEXPORT jint JNICALL
566 Agent_OnLoad(JavaVM *vm, char *options, void *reserved)</example>
567 Or for a statically linked agent named 'L':
568 <example>
569 JNIEXPORT jint JNICALL
570 Agent_OnLoad_L(JavaVM *vm, char *options, void *reserved)</example>
571
572 The VM will start the agent by calling this function.
573 It will be called early enough in VM initialization that:
574 <ul>
575 <li><functionlink id="SetSystemProperty">system properties</functionlink>
576 may be set before they have been used in the start-up of the VM</li>
577 <li>the full set of
578 <internallink id="capability">capabilities</internallink>
579 is still available (note that capabilities that configure the VM
580 may only be available at this time--see the
581 <internallink id="capability">Capability function section</internallink>)</li>
582 <li>no bytecodes have executed</li>
583 <li>no classes have been loaded</li>
584 <li>no objects have been created</li>
585 </ul>
586 <p/>
587 The VM will call the <code>Agent_OnLoad</code> or
588 <code>Agent_OnLoad_<agent-lib-name></code> function with
589 <i><options></i> as the second argument -
590 that is, using the command-line option examples,
591 <code>"opt1,opt2"</code> will be passed to the <code>char *options</code>
592 argument of <code>Agent_OnLoad</code>.
593 The <code>options</code> argument is encoded as a
594 <internallink id="mUTF">modified UTF-8</internallink> string.
595 If <i>=<options></i> is not specified,
596 a zero length string is passed to <code>options</code>.
597 The lifespan of the <code>options</code> string is the
598 <code>Agent_OnLoad</code> or <code>Agent_OnLoad_<agent-lib-name></code>
599 call. If needed beyond this time the string or parts of the string must
600 be copied.
601 The period between when <code>Agent_OnLoad</code> is called and when it
602 returns is called the <i>OnLoad phase</i>.
603 Since the VM is not initialized during the OnLoad
604 <functionlink id="GetPhase">phase</functionlink>,
605 the set of allowed operations
606 inside <code>Agent_OnLoad</code> is restricted (see the function descriptions for the
607 functionality available at this time).
608 The agent can safely process the options and set
609 event callbacks with <functionlink id="SetEventCallbacks"></functionlink>. Once
610 the VM initialization event is received
611 (that is, the <eventlink id="VMInit">VMInit</eventlink>
612 callback is invoked), the agent
613 can complete its initialization.
614 <rationale>
615 Early startup is required so that agents can set the desired capabilities,
616 many of which must be set before the VM is initialized.
617 In JVMDI, the -Xdebug command-line option provided
618 very coarse-grain control of capabilities.
619 JVMPI implementations use various tricks to provide a single "JVMPI on" switch.
620 No reasonable command-line
621 option could provide the fine-grain of control required to balance needed capabilities vs
622 performance impact.
623 Early startup is also needed so that agents can control the execution
624 environment - modifying the file system and system properties to install
625 their functionality.
626 </rationale>
627 <p/>
628 The return value from <code>Agent_OnLoad</code> or
629 <code>Agent_OnLoad_<agent-lib-name></code> is used to indicate an error.
630 Any value other than zero indicates an error and causes termination of the VM.
631 </intro>
632
633 <intro id="onattach" label="Agent Start-Up (Live phase)">
634 A VM may support a mechanism that allows agents to be started in the VM during the live
635 <functionlink id="GetPhase">phase</functionlink>. The details of how this is supported,
636 are implementation specific. For example, a tool may use some platform specific mechanism,
637 or implementation specific API, to attach to the running VM, and request it start a given
638 agent.
639 <p/>
640 If an agent is started during the live phase then its agent library
641 must export a start-up function
642 with the following prototype:
643 <example>
644 JNIEXPORT jint JNICALL
645 Agent_OnAttach(JavaVM* vm, char *options, void *reserved)</example>
646 Or for a statically linked agent named 'L':
647 <example>
648 JNIEXPORT jint JNICALL
649 Agent_OnAttach_L(JavaVM* vm, char *options, void *reserved)</example>
650
651 <p/>
652 The VM will start the agent by calling this function.
653 It will be called in the context of a thread
654 that is attached to the VM. The first argument <i><vm></i> is the Java VM.
655 The <i><options></i> argument is the startup options provided to the agent.
656 <i><options></i> is encoded as a <internallink id="mUTF">modified UTF-8
657 </internallink> string.
658 If startup options were not provided, a zero length string is passed to
659 <code>options</code>. The lifespan of the <code>options</code> string is the
660 <code>Agent_OnAttach</code> or <code>Agent_OnAttach_<agent-lib-name></code> call.
661 If needed beyond this time the string or parts of the string must be copied.
662 <p/>
663 Note that some <internallink id="capability">capabilities</internallink>
664 may not be available in the live phase.
665 <p/>
666 The <code>Agent_OnAttach</code> or <code>Agent_OnAttach_<agent-lib-name
667 ></code> function initializes the agent and returns a value
668 to the VM to indicate if an error occurred. Any value other than zero indicates an error.
669 An error does not cause the VM to terminate. Instead the VM ignores the error, or takes
670 some implementation specific action -- for example it might print an error to standard error,
671 or record the error in a system log.
672 </intro>
673
674 <intro id="onunload" label="Agent Shutdown">
675 The library may optionally export a
676 shutdown function with the following prototype:
677 <example>
678 JNIEXPORT void JNICALL
679 Agent_OnUnload(JavaVM *vm)</example>
680 Or for a statically linked agent named 'L':
681 <example>
682 JNIEXPORT void JNICALL
683 Agent_OnUnload_L(JavaVM *vm)</example>
684
685 This function will be called by the VM when the library is about to be unloaded.
686 The library will be unloaded (unless it is statically linked into the
687 executable) and this function will be called if some platform specific
688 mechanism causes the unload (an unload mechanism is not specified in this document)
689 or the library is (in effect) unloaded by the termination of the VM whether through
690 normal termination or VM failure, including start-up failure.
691 Uncontrolled shutdown is, of course, an exception to this rule.
692 Note the distinction between this function and the
693 <eventlink id="VMDeath">VM Death event</eventlink>: for the VM Death event
694 to be sent, the VM must have run at least to the point of initialization and a valid
695 <jvmti/> environment must exist which has set a callback for VMDeath
696 and enabled the event.
697 None of these are required for <code>Agent_OnUnload</code> or
698 <code>Agent_OnUnload_<agent-lib-name></code> and this function
699 is also called if the library is unloaded for other reasons.
700 In the case that a VM Death event is sent, it will be sent before this
701 function is called (assuming this function is called due to VM termination).
702 This function can be used to clean-up resources allocated by the agent.
703 </intro>
704
705 <intro id="tooloptions" label="JAVA_TOOL_OPTIONS">
706 Since the command-line cannot always be accessed or modified, for example in embedded VMs
707 or simply VMs launched deep within scripts, a <code>JAVA_TOOL_OPTIONS</code> variable is
708 provided so that agents may be launched in these cases.
709 <p/>
710 Platforms which support environment variables or other named strings, may support the
711 <code>JAVA_TOOL_OPTIONS</code> variable. This variable will be broken into options at white-space
712 boundaries. White-space characters include space, tab, carriage-return, new-line,
713 vertical-tab, and form-feed. Sequences of white-space characters are considered
714 equivalent to a single white-space character. No white-space is included in the options
715 unless quoted. Quoting is as follows:
716 <ul>
717 <li>All characters enclosed between a pair of single quote marks (''), except a single
718 quote, are quoted.</li>
719 <li>Double quote characters have no special meaning inside a pair of single quote marks.</li>
720 <li>All characters enclosed between a pair of double quote marks (""), except a double
721 quote, are quoted.</li>
722 <li>Single quote characters have no special meaning inside a pair of double quote marks.</li>
723 <li>A quoted part can start or end anywhere in the variable.</li>
724 <li>White-space characters have no special meaning when quoted -- they are included in
725 the option like any other character and do not mark white-space boundaries.</li>
726 <li>The pair of quote marks is not included in the option.</li>
727 </ul>
728 <code>JNI_CreateJavaVM</code> (in the JNI Invocation API) will prepend these options to the options supplied
729 in its <code>JavaVMInitArgs</code> argument. Platforms may disable this feature in cases where security is
730 a concern; for example, the Reference Implementation disables this feature on Unix systems when
731 the effective user or group ID differs from the real ID.
732 This feature is intended to support the initialization of tools -- specifically including the
733 launching of native or Java programming language agents. Multiple tools may wish to use this
734 feature, so the variable should not be overwritten, instead, options should be appended to
735 the variable. Note that since the variable is processed at the time of the JNI Invocation
736 API create VM call, options processed by a launcher (e.g., VM selection options) will not be handled.
737 </intro>
738
739 <intro id="environments" label="Environments">
740 The <jvmti/> specification supports the use of multiple simultaneous
741 <jvmti/> agents.
742 Each agent has its own <jvmti/> environment.
743 That is, the <jvmti/> state is
744 separate for each agent - changes to one environment do not affect the
745 others. The state of a <jvmti/>
746 environment includes:
747 <ul>
748 <li><functionlink id="SetEventCallbacks">the event callbacks</functionlink></li>
749 <li><functionlink id="SetEventNotificationMode">the set of events which are enabled</functionlink></li>
750 <li><internallink id="capability">the capabilities</internallink></li>
751 <li><internallink id="memory">the memory allocation/deallocation hooks</internallink></li>
752 </ul>
753 Although their <jvmti/> state
754 is separate, agents inspect and modify the shared state
755 of the VM, they also share the native environment in which they execute.
756 As such, an agent can perturb the results of other agents or cause them
757 to fail. It is the responsibility of the agent writer to specify the level
758 of compatibility with other agents. <jvmti/> implementations are not capable
759 of preventing destructive interactions between agents. Techniques to reduce
760 the likelihood of these occurrences are beyond the scope of this document.
761 <p/>
762 An agent creates a <jvmti/> environment
763 by passing a <jvmti/> version
764 as the interface ID to the JNI Invocation API function
765 <externallink id="jni/invocation.html#getenv">
766 <code>GetEnv</code></externallink>.
767 See <internallink id="jvmtiEnvAccess">Accessing <jvmti/> Functions</internallink>
768 for more details on the creation and use of
769 <jvmti/> environments.
770 Typically, <jvmti/> environments are created by calling <code>GetEnv</code> from
771 <internallink id="onload"><code>Agent_OnLoad</code></internallink>.
772 </intro>
773
774 <intro id="bci" label="Bytecode Instrumentation">
775 This interface does not include some events that one might expect in an interface with
776 profiling support. Some examples include full speed
777 method enter and exit events. The interface instead provides support for
778 <i>bytecode instrumentation</i>, the ability to alter the Java virtual machine
779 bytecode instructions which comprise the target program. Typically, these alterations
780 are to add "events" to the code of a method - for example, to add, at the beginning of a method,
781 a call to <code>MyProfiler.methodEntered()</code>.
782 Since the changes are purely additive, they do not modify application
783 state or behavior.
784 Because the inserted agent code is standard bytecodes, the VM can run at full speed,
785 optimizing not only the target program but also the instrumentation. If the
786 instrumentation does not involve switching from bytecode execution, no expensive
787 state transitions are needed. The result is high performance events.
788 This approach also provides complete control to the agent: instrumentation can be
789 restricted to "interesting" portions of the code (e.g., the end user's code) and
790 can be conditional. Instrumentation can run entirely in Java programming language
791 code or can call into the native agent. Instrumentation can simply maintain
792 counters or can statistically sample events.
793 <p/>
794 Instrumentation can be inserted in one of three ways:
795 <ul>
796 <li>
797 Static Instrumentation: The class file is instrumented before it
798 is loaded into the VM - for example, by creating a duplicate directory of
799 <code>*.class</code> files which have been modified to add the instrumentation.
800 This method is extremely awkward and, in general, an agent cannot know
801 the origin of the class files which will be loaded.
802 </li>
803 <li>
804 Load-Time Instrumentation: When a class file is loaded by the VM, the raw
805 bytes of the class file are sent for instrumentation to the agent.
806 The <eventlink id="ClassFileLoadHook"/>
807 event, triggered by the class load,
808 provides this functionality. This mechanism provides efficient
809 and complete access to one-time instrumentation.
810 </li>
811 <li>
812 Dynamic Instrumentation: A class which is already loaded (and possibly
813 even running) is modified. This optional feature is provided by the
814 <eventlink id="ClassFileLoadHook"/> event, triggered by calling the
815 <functionlink id="RetransformClasses"/> function.
816 Classes can be modified multiple times and can be returned to their
817 original state.
818 The mechanism allows instrumentation which changes during the
819 course of execution.
820 </li>
821 </ul>
822 <p/>
823 The class modification functionality provided in this interface
824 is intended to provide a mechanism for instrumentation
825 (the <eventlink id="ClassFileLoadHook"/> event
826 and the <functionlink id="RetransformClasses"/> function)
827 and, during development, for fix-and-continue debugging
828 (the <functionlink id="RedefineClasses"/> function).
829 <p/>
830 Care must be taken to avoid perturbing dependencies, especially when
831 instrumenting core classes. For example, an approach to getting notification
832 of every object allocation is to instrument the constructor on
833 <code>Object</code>. Assuming that the constructor is initially
834 empty, the constructor could be changed to:
835 <example>
836 public Object() {
837 MyProfiler.allocationTracker(this);
838 }
839 </example>
840 However, if this change was made using the
841 <eventlink id="ClassFileLoadHook"/>
842 event then this might impact a typical VM as follows:
843 the first created object will call the constructor causing a class load of
844 <code>MyProfiler</code>; which will then cause
845 object creation, and since <code>MyProfiler</code> isn't loaded yet,
846 infinite recursion; resulting in a stack overflow. A refinement of this
847 would be to delay invoking the tracking method until a safe time. For
848 example, <code>trackAllocations</code> could be set in the
849 handler for the <code>VMInit</code> event.
850 <example>
851 static boolean trackAllocations = false;
852
853 public Object() {
854 if (trackAllocations) {
855 MyProfiler.allocationTracker(this);
856 }
857 }
858 </example>
859 <p/>
860 The <functionlink id="SetNativeMethodPrefix"/> allows native methods
861 to be instrumented by the use of wrapper methods.
862 </intro>
863
864 <intro id="bcimodules" label="Bytecode Instrumentation of code in modules">
865 Agents can use the functions <functionlink id="AddModuleReads"/>,
866 <functionlink id="AddModuleExports"/>, <functionlink id="AddModuleOpens"/>,
867 <functionlink id="AddModuleUses"/> and <functionlink id="AddModuleProvides"/>
868 to update a module to expand the set of modules that it reads, the set of
869 packages that it exports or opens to other modules, or the services that it
870 uses and provides.
871 <p/>
872 As an aid to agents that deploy supporting classes on the search path of
873 the bootstrap class loader, or the search path of the class loader that
874 loads the main class, the Java virtual machine arranges for the module
875 of classes transformed by the <eventlink id="ClassFileLoadHook"/> event to
876 read the unnamed module of both class loaders.
877 </intro>
878
879 <intro id="mUTF" label="Modified UTF-8 String Encoding">
880 <jvmti/> uses modified UTF-8 to encode character strings.
881 This is the same encoding used by JNI.
882 Modified UTF-8 differs
883 from standard UTF-8 in the representation of supplementary characters
884 and of the null character. See the
885 <externallink id="jni/types.html#modified-utf-8-strings">
886 Modified UTF-8 Strings</externallink>
887 section of the JNI specification for details.
888 </intro>
889
890 <intro id="context" label="Specification Context">
891 Since this interface provides access to the state of applications running in the
892 Java virtual machine;
893 terminology refers to the Java platform and not the native
894 platform (unless stated otherwise). For example:
895 <ul>
896 <li>"thread" means Java programming language thread.</li>
897 <li>"stack frame" means Java virtual machine stack frame.</li>
898 <li>"class" means Java programming language class.</li>
899 <li>"heap" means Java virtual machine heap.</li>
900 <li>"monitor" means Java programming language object monitor.</li>
901 </ul>
902 <p/>
903 Sun, Sun Microsystems, the Sun logo, Java, and JVM
904 are trademarks or registered trademarks of Oracle
905 and/or its affiliates, in the U.S. and other countries.
906 </intro>
907
908
909 <functionsection label="Functions">
910 <intro id="jvmtiEnvAccess" label="Accessing Functions">
911 Native code accesses <jvmti/> features
912 by calling <jvmti/> functions.
913 Access to <jvmti/> functions is by use of an interface pointer
914 in the same manner as
915 <externallink id="jni/design.html">Java
916 Native Interface (JNI) functions</externallink> are accessed.
917 The <jvmti/> interface pointer is called the
918 <i>environment pointer</i>.
919 <p/>
920 An environment pointer is a pointer to an environment and has
921 the type <code>jvmtiEnv*</code>.
922 An environment has information about its <jvmti/> connection.
923 The first value in the environment is a pointer to the function table.
924 The function table is an array of pointers to <jvmti/> functions.
925 Every function pointer is at a predefined offset inside the
926 array.
927 <p/>
928 When used from the C language:
929 double indirection is used to access the functions;
930 the environment pointer provides context and is the first
931 parameter of each function call; for example:
932 <example>
933 jvmtiEnv *jvmti;
934 ...
935 jvmtiError err = (*jvmti)->GetLoadedClasses(jvmti, &class_count, &classes);
936 </example>
937 <p/>
938 When used from the C++ language:
939 functions are accessed as member functions of <code>jvmtiEnv</code>;
940 the environment pointer is not passed to the function call; for example:
941 <example>
942 jvmtiEnv *jvmti;
943 ...
944 jvmtiError err = jvmti->GetLoadedClasses(&class_count, &classes);
945 </example>
946 Unless otherwise stated, all examples and declarations in this
947 specification use the C language.
948 <p/>
949 A <jvmti/> environment can be obtained through the JNI Invocation API
950 <code>GetEnv</code> function:
951 <example>
952 jvmtiEnv *jvmti;
953 ...
954 (*jvm)->GetEnv(jvm, &jvmti, JVMTI_VERSION_1_0);
955 </example>
956 Each call to <code>GetEnv</code>
957 creates a new <jvmti/> connection and thus
958 a new <jvmti/> environment.
959 The <code>version</code> argument of <code>GetEnv</code> must be
960 a <jvmti/> version.
961 The returned environment may have a different version than the
962 requested version but the returned environment must be compatible.
963 <code>GetEnv</code> will return <code>JNI_EVERSION</code> if a
964 compatible version is not available, if <jvmti/> is not supported or
965 <jvmti/> is not supported in the current VM configuration.
966 Other interfaces may be added for creating <jvmti/> environments
967 in specific contexts.
968 Each environment has its own state (for example,
969 <functionlink id="SetEventNotificationMode">desired events</functionlink>,
970 <functionlink id="SetEventCallbacks">event handling functions</functionlink>, and
971 <functionlink id="AddCapabilities">capabilities</functionlink>).
972 An environment is released with
973 <functionlink id="DisposeEnvironment"></functionlink>.
974 Thus, unlike JNI which has one environment per thread, <jvmti/> environments work
975 across threads and are created dynamically.
976 </intro>
977
978 <intro id="functionReturn" label="Function Return Values">
979 <jvmti/> functions always return an
980 <internallink id="ErrorSection">error code</internallink> via the
981 <datalink id="jvmtiError"/> function return value.
982 Some functions can return additional
983 values through pointers provided by the calling function.
984 In some cases, <jvmti/> functions allocate memory that your program must
985 explicitly deallocate. This is indicated in the individual <jvmti/>
986 function descriptions. Empty lists, arrays, sequences, etc are
987 returned as <code>NULL</code>.
988 <p/>
989 In the event that the <jvmti/> function encounters
990 an error (any return value other than <code>JVMTI_ERROR_NONE</code>) the values
991 of memory referenced by argument pointers is undefined, but no memory
992 will have been allocated and no global references will have been allocated.
993 If the error occurs because of invalid input, no action will have occurred.
994 </intro>
995
996 <intro id="refs" label="Managing JNI Object References">
997 <jvmti/> functions identify objects with JNI references
998 (<datalink id="jobject"/> and <datalink id="jclass"/>)
999 and their derivatives
1000 (<datalink id="jthread"/> and <datalink id="jthreadGroup"/>).
1001 References passed to
1002 <jvmti/> functions can be either global or local, but they must be
1003 strong references. All references returned by <jvmti/> functions are
1004 local references--these local references are created
1005 during the <jvmti/> call.
1006 Local references are a resource that must be managed (see the
1007 <externallink id="jni/functions.html#local-references">
1008 JNI Documentation</externallink>).
1009 When threads return from native code all local references
1010 are freed. Note that some threads, including typical
1011 agent threads, will never return from native code.
1012 A thread is ensured the ability to create sixteen local
1013 references without the need for any explicit management.
1014 For threads executing a limited number of <jvmti/> calls before
1015 returning from native code
1016 (for example, threads processing events),
1017 it may be determined that no explicit management
1018 is needed.
1019 However, long running agent threads will need explicit
1020 local reference management--usually with the JNI functions
1021 <code>PushLocalFrame</code> and <code>PopLocalFrame</code>.
1022 Conversely, to preserve references beyond the
1023 return from native code, they must be converted to global references.
1024 These rules do not apply to <datalink id="jmethodID"/> and <datalink id="jfieldID"/>
1025 as they are not <datalink id="jobject"/>s.
1026 </intro>
1027
1028 <intro id="prereqState" label="Prerequisite State for Calling Functions">
1029 Unless the function explicitly states that the agent must bring
1030 a thread or the VM to a particular state (for example, suspended),
1031 the <jvmti/> implementation is responsible for bringing the VM to a
1032 safe and consistent state for performing the function.
1033 </intro>
1034
1035 <intro id="functionsExceptions" label="Exceptions and Functions">
1036 <jvmti/> functions never throw exceptions; error conditions are
1037 communicated via the
1038 <internallink id="functionReturn">function return value</internallink>.
1039 Any existing exception state is preserved across a call to a
1040 <jvmti/> function.
1041 See the
1042 <externallink
1043 id="jni/design.html#java-exceptions"
1044 >Java Exceptions</externallink>
1045 section of the JNI specification for information on handling exceptions.
1046 </intro>
1047
1048 <category id="memory" label="Memory Management">
1049 <intro>
1050 These functions provide for the allocation and deallocation of
1051 memory used by <jvmti/> functionality and can be used to provide
1052 working memory for agents.
1053 Memory managed by <jvmti/> is not compatible with other memory
1054 allocation libraries and mechanisms.
1055 </intro>
1056
1057 <function id="Allocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="46">
1058 <synopsis>Allocate</synopsis>
1059 <description>
1060 Allocate an area of memory through the <jvmti/> allocator.
1061 The allocated
1062 memory should be freed with <functionlink id="Deallocate"></functionlink>.
1063 </description>
1064 <origin>jvmdi</origin>
1065 <capabilities>
1066 </capabilities>
1067 <parameters>
1068 <param id="size">
1069 <jlong/>
1070 <description>
1071 The number of bytes to allocate.
1072 <rationale>
1073 <code>jlong</code> is used for compatibility with JVMDI.
1074 </rationale>
1075 </description>
1076 </param>
1077 <param id="mem_ptr">
1078 <allocbuf incount="size"><uchar/></allocbuf>
1079 <description>
1080 On return, a pointer to the beginning of the allocated memory.
1081 If <code>size</code> is zero, <code>NULL</code> is returned.
1082 </description>
1083 </param>
1084 </parameters>
1085 <errors>
1086 <error id="JVMTI_ERROR_OUT_OF_MEMORY">
1087 Memory request cannot be honored.
1088 </error>
1089 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
1090 <paramlink id="size"></paramlink> is less than zero.
1091 </error>
1092 </errors>
1093 </function>
1094
1095 <function id="Deallocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="47">
1096 <synopsis>Deallocate</synopsis>
1097 <description>
1098 Deallocate <code>mem</code> using the <jvmti/> allocator.
1099 This function should
1100 be used to deallocate any memory allocated and returned
1101 by a <jvmti/> function
1102 (including memory allocated with <functionlink id="Allocate"></functionlink>).
1103 All allocated memory must be deallocated
1104 or the memory cannot be reclaimed.
1105 </description>
1106 <origin>jvmdi</origin>
1107 <capabilities>
1108 </capabilities>
1109 <parameters>
1110 <param id="mem">
1111 <outbuf>
1112 <uchar/>
1113 <nullok>the call is ignored</nullok>
1114 </outbuf>
1115 <description>
1116 A pointer to the beginning of the allocated memory.
1117 Please ignore "On return, the elements are set."
1118 <todo>keep it from generating "On return, the elements are set"</todo>
1119 </description>
1120 </param>
1121 </parameters>
1122 <errors>
1123 </errors>
1124 </function>
1125 </category>
1126
1127 <category id="threadCategory" label="Thread">
1128 <intro>
1129 </intro>
1130
1131 <function id="GetThreadState" num="17">
1132 <synopsis>Get Thread State</synopsis>
1133 <description>
1134 Get the state of a thread. The state of the thread is represented by the
1135 answers to the hierarchical set of questions below:
1136 <ul type="circle">
1137 <li><i>Alive?</i>
1138 <ul>
1139 <li>Not alive.
1140 <ul type="circle">
1141 <li><i>Why not alive?</i>
1142 <ul>
1143 <li>New.</li>
1144 <li>Terminated (<datalink
1145 id="JVMTI_THREAD_STATE_TERMINATED"><code>JVMTI_THREAD_STATE_TERMINATED</code></datalink>)</li>
1146 </ul>
1147 </li>
1148 </ul>
1149 </li>
1150 <li>Alive (<datalink
1151 id="JVMTI_THREAD_STATE_ALIVE"><code>JVMTI_THREAD_STATE_ALIVE</code></datalink>)
1152 <ul type="circle">
1153 <li><i>Suspended?</i>
1154 <ul>
1155 <li>Suspended (<datalink
1156 id="JVMTI_THREAD_STATE_SUSPENDED"><code>JVMTI_THREAD_STATE_SUSPENDED</code></datalink>)</li>
1157 <li>Not suspended</li>
1158 </ul>
1159 </li>
1160 <li><i>Interrupted?</i>
1161 <ul>
1162 <li>Interrupted (<datalink
1163 id="JVMTI_THREAD_STATE_INTERRUPTED"><code>JVMTI_THREAD_STATE_INTERRUPTED</code></datalink>)</li>
1164 <li>Not interrupted.</li>
1165 </ul>
1166 </li>
1167 <li><i>In native?</i>
1168 <ul>
1169 <li>In native code (<datalink
1170 id="JVMTI_THREAD_STATE_IN_NATIVE"><code>JVMTI_THREAD_STATE_IN_NATIVE</code></datalink>)</li>
1171 <li>In Java programming language code</li>
1172 </ul>
1173 </li>
1174 <li><i>What alive state?</i>
1175 <ul>
1176 <li>Runnable (<datalink
1177 id="JVMTI_THREAD_STATE_RUNNABLE"><code>JVMTI_THREAD_STATE_RUNNABLE</code></datalink>)</li>
1178 <li>Blocked (<datalink
1179 id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER"><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></datalink>)</li>
1180 <li>Waiting (<datalink
1181 id="JVMTI_THREAD_STATE_WAITING"><code>JVMTI_THREAD_STATE_WAITING</code></datalink>)
1182 <ul type="circle">
1183 <li><i>Timed wait?</i>
1184 <ul>
1185 <li>Indefinite (<datalink
1186 id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY"><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></datalink></li>
1187 <li>Timed (<datalink
1188 id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT"><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></datalink>)</li>
1189 </ul>
1190 </li>
1191 <li><i>Why waiting?</i>
1192 <ul>
1193 <li>Object.wait (<datalink
1194 id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT"><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></datalink>)</li>
1195 <li>LockSupport.park (<datalink
1196 id="JVMTI_THREAD_STATE_PARKED"><code>JVMTI_THREAD_STATE_PARKED</code></datalink>)</li>
1197 <li>Sleeping (<datalink
1198 id="JVMTI_THREAD_STATE_SLEEPING"><code>JVMTI_THREAD_STATE_SLEEPING</code></datalink>)</li>
1199 </ul>
1200 </li>
1201 </ul>
1202 </li>
1203 </ul>
1204 </li>
1205 </ul>
1206 </li>
1207 </ul>
1208 </li>
1209 </ul>
1210 <p/>
1211 The answers are represented by the following bit vector.
1212 <constants id="jvmtiThreadState" label="Thread State Flags" kind="bits">
1213 <constant id="JVMTI_THREAD_STATE_ALIVE" num="0x0001">
1214 Thread is alive. Zero if thread is new (not started) or terminated.
1215 </constant>
1216 <constant id="JVMTI_THREAD_STATE_TERMINATED" num="0x0002">
1217 Thread has completed execution.
1218 </constant>
1219 <constant id="JVMTI_THREAD_STATE_RUNNABLE" num="0x0004">
1220 Thread is runnable.
1221 </constant>
1222 <constant id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER" num="0x0400">
1223 Thread is waiting to enter a synchronization block/method or,
1224 after an <code>Object.wait()</code>, waiting to re-enter a
1225 synchronization block/method.
1226 </constant>
1227 <constant id="JVMTI_THREAD_STATE_WAITING" num="0x0080">
1228 Thread is waiting.
1229 </constant>
1230 <constant id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY" num="0x0010">
1231 Thread is waiting without a timeout.
1232 For example, <code>Object.wait()</code>.
1233 </constant>
1234 <constant id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT" num="0x0020">
1235 Thread is waiting with a maximum time to wait specified.
1236 For example, <code>Object.wait(long)</code>.
1237 </constant>
1238 <constant id="JVMTI_THREAD_STATE_SLEEPING" num="0x0040">
1239 Thread is sleeping -- <code>Thread.sleep(long)</code>.
1240 </constant>
1241 <constant id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT" num="0x0100">
1242 Thread is waiting on an object monitor -- <code>Object.wait</code>.
1243 </constant>
1244 <constant id="JVMTI_THREAD_STATE_PARKED" num="0x0200">
1245 Thread is parked, for example: <code>LockSupport.park</code>,
1246 <code>LockSupport.parkUtil</code> and <code>LockSupport.parkNanos</code>.
1247 </constant>
1248 <constant id="JVMTI_THREAD_STATE_SUSPENDED" num="0x100000">
1249 Thread suspended.
1250 <code>java.lang.Thread.suspend()</code>
1251 or a <jvmti/> suspend function
1252 (such as <functionlink id="SuspendThread"></functionlink>)
1253 has been called on the thread. If this bit
1254 is set, the other bits refer to the thread state before suspension.
1255 </constant>
1256 <constant id="JVMTI_THREAD_STATE_INTERRUPTED" num="0x200000">
1257 Thread has been interrupted.
1258 </constant>
1259 <constant id="JVMTI_THREAD_STATE_IN_NATIVE" num="0x400000">
1260 Thread is in native code--that is, a native method is running
1261 which has not called back into the VM or Java programming
1262 language code.
1263 <p/>
1264 This flag is not set when running VM compiled Java programming
1265 language code nor is it set when running VM code or
1266 VM support code. Native VM interface functions, such as JNI and
1267 <jvmti/> functions, may be implemented as VM code.
1268 </constant>
1269 <constant id="JVMTI_THREAD_STATE_VENDOR_1" num="0x10000000">
1270 Defined by VM vendor.
1271 </constant>
1272 <constant id="JVMTI_THREAD_STATE_VENDOR_2" num="0x20000000">
1273 Defined by VM vendor.
1274 </constant>
1275 <constant id="JVMTI_THREAD_STATE_VENDOR_3" num="0x40000000">
1276 Defined by VM vendor.
1277 </constant>
1278 </constants>
1279 The following definitions are used to convert <jvmti/> thread state
1280 to <code>java.lang.Thread.State</code> style states.
1281 <constants id="jvmtiJavaLangThreadState" label="java.lang.Thread.State Conversion Masks" kind="bits">
1282 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_MASK"
1283 num="JVMTI_THREAD_STATE_TERMINATED | JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT">
1284 Mask the state with this before comparison
1285 </constant>
1286 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_NEW"
1287 num="0">
1288 <code>java.lang.Thread.State.NEW</code>
1289 </constant>
1290 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED"
1291 num="JVMTI_THREAD_STATE_TERMINATED">
1292 <code>java.lang.Thread.State.TERMINATED</code>
1293 </constant>
1294 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE"
1295 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE">
1296 <code>java.lang.Thread.State.RUNNABLE</code>
1297 </constant>
1298 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED"
1299 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER">
1300 <code>java.lang.Thread.State.BLOCKED</code>
1301 </constant>
1302 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_WAITING"
1303 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY">
1304 <code>java.lang.Thread.State.WAITING</code>
1305 </constant>
1306 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING"
1307 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT">
1308 <code>java.lang.Thread.State.TIMED_WAITING</code>
1309 </constant>
1310 </constants>
1311 <b>Rules</b>
1312 <p/>
1313 There can be no more than one answer to a question, although there can be no
1314 answer (because the answer is unknown, does not apply, or none of the answers is
1315 correct). An answer is set only when the enclosing answers match.
1316 That is, no more than one of
1317 <ul type="circle">
1318 <li><code>JVMTI_THREAD_STATE_RUNNABLE</code></li>
1319 <li><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></li>
1320 <li><code>JVMTI_THREAD_STATE_WAITING</code></li>
1321 </ul>
1322 can be set (a <tm>J2SE</tm> compliant implementation will always set
1323 one of these if <code>JVMTI_THREAD_STATE_ALIVE</code> is set).
1324 And if any of these are set, the enclosing answer
1325 <code>JVMTI_THREAD_STATE_ALIVE</code> is set.
1326 No more than one of
1327 <ul type="circle">
1328 <li><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></li>
1329 <li><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></li>
1330 </ul>
1331 can be set (a <tm>J2SE</tm> compliant implementation will always set
1332 one of these if <code>JVMTI_THREAD_STATE_WAITING</code> is set).
1333 And if either is set, the enclosing answers
1334 <code>JVMTI_THREAD_STATE_ALIVE</code> and
1335 <code>JVMTI_THREAD_STATE_WAITING</code> are set.
1336 No more than one of
1337 <ul type="circle">
1338 <li><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></li>
1339 <li><code>JVMTI_THREAD_STATE_PARKED</code></li>
1340 <li><code>JVMTI_THREAD_STATE_SLEEPING</code></li>
1341 </ul>
1342 can be set. And if any of these is set, the enclosing answers
1343 <code>JVMTI_THREAD_STATE_ALIVE</code> and
1344 <code>JVMTI_THREAD_STATE_WAITING</code> are set.
1345 Also, if <code>JVMTI_THREAD_STATE_SLEEPING</code> is set,
1346 then <code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code> is set.
1347 If a state <i>A</i> is implemented using the mechanism of
1348 state <i>B</i> then it is state <i>A</i> which
1349 is returned by this function.
1350 For example, if <code>Thread.sleep(long)</code>
1351 is implemented using <code>Object.wait(long)</code>
1352 then it is still <code>JVMTI_THREAD_STATE_SLEEPING</code>
1353 which is returned.
1354 More than one of
1355 <ul type="circle">
1356 <li><code>JVMTI_THREAD_STATE_SUSPENDED</code></li>
1357 <li><code>JVMTI_THREAD_STATE_INTERRUPTED</code></li>
1358 <li><code>JVMTI_THREAD_STATE_IN_NATIVE</code></li>
1359 </ul>
1360 can be set, but if any is set,
1361 <code>JVMTI_THREAD_STATE_ALIVE</code> is set.
1362 <p/>
1363 And finally,
1364 <code>JVMTI_THREAD_STATE_TERMINATED</code> cannot be set unless
1365 <code>JVMTI_THREAD_STATE_ALIVE</code> is not set.
1366 <p/>
1367 The thread state representation is designed for extension in future versions
1368 of the specification; thread state values should be used accordingly, that is
1369 they should not be used as ordinals.
1370 Most queries can be made by testing a single bit, if use in a switch statement is desired,
1371 the state bits should be masked with the interesting bits.
1372 All bits not defined above are reserved for future use.
1373 A VM, compliant to the current specification, must set reserved bits to zero.
1374 An agent should ignore reserved bits --
1375 they should not be assumed to be zero and thus should not be included in comparisons.
1376 <p/>
1377 <b>Examples</b>
1378 <p/>
1379 Note that the values below exclude reserved and vendor bits.
1380 <p/>
1381 The state of a thread blocked at a <code>synchronized</code>-statement would be:
1382 <example>
1383 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER
1384 </example>
1385 The state of a thread which hasn't started yet would be:
1386 <example>
1387 0
1388 </example>
1389 The state of a thread at a <code>Object.wait(3000)</code> would be:
1390 <example>
1391 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_WAITING +
1392 JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT +
1393 JVMTI_THREAD_STATE_MONITOR_WAITING
1394 </example>
1395 The state of a thread suspended while runnable would be:
1396 <example>
1397 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_RUNNABLE + JVMTI_THREAD_STATE_SUSPENDED
1398 </example>
1399 <p/>
1400 <b>Testing the State</b>
1401 <p/>
1402 In most cases, the thread state can be determined by testing the one bit corresponding
1403 to that question. For example, the code to test if a thread is sleeping:
1404 <example>
1405 jint state;
1406 jvmtiError err;
1407
1408 err = (*jvmti)->GetThreadState(jvmti, thread, &state);
1409 if (err == JVMTI_ERROR_NONE) {
1410 if (state & JVMTI_THREAD_STATE_SLEEPING) { ...
1411 </example>
1412 <p/>
1413 For waiting (that is, in <code>Object.wait</code>, parked, or sleeping) it would be:
1414 <example>
1415 if (state & JVMTI_THREAD_STATE_WAITING) { ...
1416 </example>
1417 For some states, more than one bit will need to be tested as is the case
1418 when testing if a thread has not yet been started:
1419 <example>
1420 if ((state & (JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_TERMINATED)) == 0) { ...
1421 </example>
1422 To distinguish timed from untimed <code>Object.wait</code>:
1423 <example>
1424 if (state & JVMTI_THREAD_STATE_IN_OBJECT_WAIT) {
1425 if (state & JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT) {
1426 printf("in Object.wait(long timeout)\n");
1427 } else {
1428 printf("in Object.wait()\n");
1429 }
1430 }
1431 </example>
1432 <p/>
1433 <b>Relationship to <code>java.lang.Thread.State</code></b>
1434 <p/>
1435 The thread state represented by <code>java.lang.Thread.State</code>
1436 returned from <code>java.lang.Thread.getState()</code> is a subset of the
1437 information returned from this function.
1438 The corresponding <code>java.lang.Thread.State</code> can be determined
1439 by using the provided conversion masks.
1440 For example, this returns the name of the <code>java.lang.Thread.State</code> thread state:
1441 <example>
1442 err = (*jvmti)->GetThreadState(jvmti, thread, &state);
1443 abortOnError(err);
1444 switch (state & JVMTI_JAVA_LANG_THREAD_STATE_MASK) {
1445 case JVMTI_JAVA_LANG_THREAD_STATE_NEW:
1446 return "NEW";
1447 case JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED:
1448 return "TERMINATED";
1449 case JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE:
1450 return "RUNNABLE";
1451 case JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED:
1452 return "BLOCKED";
1453 case JVMTI_JAVA_LANG_THREAD_STATE_WAITING:
1454 return "WAITING";
1455 case JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING:
1456 return "TIMED_WAITING";
1457 }
1458 </example>
1459 </description>
1460 <origin>new</origin>
1461 <capabilities>
1462 </capabilities>
1463 <parameters>
1464 <param id="thread">
1465 <jthread null="current" started="maybe" impl="noconvert"/>
1466 <description>
1467 The thread to query.
1468 </description>
1469 </param>
1470 <param id="thread_state_ptr">
1471 <outptr><jint/></outptr>
1472 <description>
1473 On return, points to state flags,
1474 as defined by the <internallink id="jvmtiThreadState">Thread State Flags</internallink>.
1475 </description>
1476 </param>
1477 </parameters>
1478 <errors>
1479 </errors>
1480 </function>
1481
1482 <function id="GetCurrentThread" phase="start" num="18" since="1.1">
1483 <synopsis>Get Current Thread</synopsis>
1484 <description>
1485 Get the current thread.
1486 The current thread is the Java programming language thread which has called the function.
1487 The function may return <code>NULL</code> in the start phase if the
1488 <internallink id="jvmtiCapabilities.can_generate_early_vmstart">
1489 <code>can_generate_early_vmstart</code></internallink> capability is enabled
1490 and the <code>java.lang.Thread</code> class has not been initialized yet.
1491 <p/>
1492 Note that most <jvmti/> functions that take a thread
1493 as an argument will accept <code>NULL</code> to mean
1494 the current thread.
1495 </description>
1496 <origin>new</origin>
1497 <capabilities>
1498 </capabilities>
1499 <parameters>
1500 <param id="thread_ptr">
1501 <outptr><jthread/></outptr>
1502 <description>
1503 On return, points to the current thread, or <code>NULL</code>.
1504 </description>
1505 </param>
1506 </parameters>
1507 <errors>
1508 </errors>
1509 </function>
1510
1511 <function id="GetAllThreads" num="4">
1512 <synopsis>Get All Threads</synopsis>
1513 <description>
1514 Get all live threads.
1515 The threads are Java programming language threads;
1516 that is, threads that are attached to the VM.
1517 A thread is live if <code>java.lang.Thread.isAlive()</code>
1518 would return <code>true</code>, that is, the thread has
1519 been started and has not yet died.
1520 The universe of threads is determined by the context of the <jvmti/>
1521 environment, which typically is all threads attached to the VM.
1522 Note that this includes <jvmti/> agent threads
1523 (see <functionlink id="RunAgentThread"/>).
1524 </description>
1525 <origin>jvmdi</origin>
1526 <capabilities>
1527 </capabilities>
1528 <parameters>
1529 <param id="threads_count_ptr">
1530 <outptr><jint/></outptr>
1531 <description>
1532 On return, points to the number of running threads.
1533 </description>
1534 </param>
1535 <param id="threads_ptr">
1536 <allocbuf outcount="threads_count_ptr"><jthread/></allocbuf>
1537 <description>
1538 On return, points to an array of references, one
1539 for each running thread.
1540 </description>
1541 </param>
1542 </parameters>
1543 <errors>
1544 </errors>
1545 </function>
1546
1547 <function id="SuspendThread" num="5">
1548 <synopsis>Suspend Thread</synopsis>
1549 <description>
1550 Suspend the specified thread. If the calling thread is specified,
1551 this function will not return until some other thread calls
1552 <functionlink id="ResumeThread"></functionlink>.
1553 If the thread is currently suspended, this function
1554 does nothing and returns an error.
1555 </description>
1556 <origin>jvmdi</origin>
1557 <capabilities>
1558 <required id="can_suspend"></required>
1559 </capabilities>
1560 <parameters>
1561 <param id="thread">
1562 <jthread null="current"/>
1563 <description>
1564 The thread to suspend.
1565 </description>
1566 </param>
1567 </parameters>
1568 <errors>
1569 <error id="JVMTI_ERROR_THREAD_SUSPENDED">
1570 Thread already suspended.
1571 </error>
1572 </errors>
1573 </function>
1574
1575 <elide>
1576 <function id="SuspendAllThreads" num="101">
1577 <synopsis>Suspend All Threads</synopsis>
1578 <description>
1579 <issue>
1580 There has been no explicit call for this function, and it will
1581 thus be removed if there is no interest.
1582 </issue>
1583 Suspend all live threads except:
1584 <ul>
1585 <li>already suspended threads</li>
1586 <li>those listed in <paramlink id="except_list"></paramlink></li>
1587 <li>certain system (non application) threads, as determined
1588 by the VM implementation</li>
1589 </ul>
1590 The threads are Java programming language threads;
1591 native threads which are not attached to the VM are not
1592 Java programming language threads.
1593 A thread is live if <code>java.lang.Thread.isAlive()</code>
1594 would return <code>true</code>, that is, the thread has
1595 been started and has not yet died.
1596 The universe of threads is determined
1597 by the context of the <jvmti/>
1598 environment, which, typically, is all threads attached to the VM,
1599 except critical VM internal threads and <jvmti/> agent threads
1600 (see <functionlink id="RunAgentThread"/>).
1601 <p/>
1602 If the calling thread is specified,
1603 all other threads are suspended first then the caller thread is suspended -
1604 this function will not return until some other thread calls
1605 <functionlink id="ResumeThread"></functionlink>.
1606 <p/>
1607 The list of actually
1608 suspended threads is returned in
1609 <paramlink id="suspended_list_ptr"></paramlink>.
1610 Suspension is as defined in <functionlink id="SuspendThread"></functionlink>.
1611 <functionlink id="ResumeThreadList"></functionlink>
1612 can be used to resume the suspended threads.
1613 </description>
1614 <origin>new</origin>
1615 <capabilities>
1616 <required id="can_suspend"></required>
1617 </capabilities>
1618 <parameters>
1619 <param id="except_count">
1620 <jint min="0"/>
1621 <description>
1622 The number of threads in the list of threads not to be suspended.
1623 </description>
1624 </param>
1625 <param id="except_list">
1626 <inbuf incount="except_count">
1627 <jthread/>
1628 <nullok>not an error if <code>except_count == 0</code></nullok>
1629 </inbuf>
1630 <description>
1631 The list of threads not to be suspended.
1632 </description>
1633 </param>
1634 <param id="suspended_count_ptr">
1635 <outptr><jint/></outptr>
1636 <description>
1637 On return, points to the number of threads suspended by this call.
1638 </description>
1639 </param>
1640 <param id="suspended_list_ptr">
1641 <allocbuf outcount="suspended_count_ptr"><jthread/></allocbuf>
1642 <description>
1643 On return, points to an array of references, one
1644 for each thread suspended.
1645 </description>
1646 </param>
1647 </parameters>
1648 <errors>
1649 <error id="JVMTI_ERROR_INVALID_THREAD">
1650 A thread in <paramlink id="except_list"></paramlink> was invalid.
1651 </error>
1652 <error id="JVMTI_ERROR_NULL_POINTER">
1653 Both <paramlink id="except_list"></paramlink> was <code>NULL</code>
1654 and <paramlink id="except_count"></paramlink> was non-zero.
1655 </error>
1656 </errors>
1657 </function>
1658 </elide>
1659
1660 <function id="SuspendThreadList" num="92">
1661 <synopsis>Suspend Thread List</synopsis>
1662 <description>
1663 Suspend the <paramlink id="request_count"></paramlink>
1664 threads specified in the
1665 <paramlink id="request_list"></paramlink> array.
1666 Threads may be resumed with
1667 <functionlink id="ResumeThreadList"></functionlink> or
1668 <functionlink id="ResumeThread"></functionlink>.
1669 If the calling thread is specified in the
1670 <paramlink id="request_list"></paramlink> array, this function will
1671 not return until some other thread resumes it.
1672 Errors encountered in the suspension of a thread
1673 are returned in the <paramlink id="results"></paramlink>
1674 array, <b>not</b> in the return value of this function.
1675 Threads that are currently suspended do not change state.
1676 </description>
1677 <origin>jvmdi</origin>
1678 <capabilities>
1679 <required id="can_suspend"></required>
1680 </capabilities>
1681 <parameters>
1682 <param id="request_count">
1683 <jint min="0"/>
1684 <description>
1685 The number of threads to suspend.
1686 </description>
1687 </param>
1688 <param id="request_list">
1689 <inbuf incount="request_count"><jthread/></inbuf>
1690 <description>
1691 The list of threads to suspend.
1692 </description>
1693 </param>
1694 <param id="results">
1695 <outbuf incount="request_count"><enum>jvmtiError</enum></outbuf>
1696 <description>
1697 An agent supplied array of
1698 <paramlink id="request_count"></paramlink> elements.
1699 On return, filled with the error code for
1700 the suspend of the corresponding thread.
1701 The error code will be
1702 <errorlink id="JVMTI_ERROR_NONE"></errorlink>
1703 if the thread was suspended by this call.
1704 Possible error codes are those specified
1705 for <functionlink id="SuspendThread"></functionlink>.
1706 </description>
1707 </param>
1708 </parameters>
1709 <errors>
1710 </errors>
1711 </function>
1712
1713 <function id="ResumeThread" num="6">
1714 <synopsis>Resume Thread</synopsis>
1715 <description>
1716 Resume a suspended thread.
1717 Any threads currently suspended through
1718 a <jvmti/> suspend function (eg.
1719 <functionlink id="SuspendThread"></functionlink>)
1720 or <code>java.lang.Thread.suspend()</code>
1721 will resume execution;
1722 all other threads are unaffected.
1723 </description>
1724 <origin>jvmdi</origin>
1725 <capabilities>
1726 <required id="can_suspend"></required>
1727 </capabilities>
1728 <parameters>
1729 <param id="thread">
1730 <jthread/>
1731 <description>
1732 The thread to resume.
1733 </description>
1734 </param>
1735 </parameters>
1736 <errors>
1737 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
1738 Thread was not suspended.
1739 </error>
1740 <error id="JVMTI_ERROR_INVALID_TYPESTATE">
1741 The state of the thread has been modified, and is now inconsistent.
1742 </error>
1743 </errors>
1744 </function>
1745
1746 <function id="ResumeThreadList" num="93">
1747 <synopsis>Resume Thread List</synopsis>
1748 <description>
1749 Resume the <paramlink id="request_count"></paramlink>
1750 threads specified in the
1751 <paramlink id="request_list"></paramlink> array.
1752 Any thread suspended through
1753 a <jvmti/> suspend function (eg.
1754 <functionlink id="SuspendThreadList"></functionlink>)
1755 or <code>java.lang.Thread.suspend()</code>
1756 will resume execution.
1757 </description>
1758 <origin>jvmdi</origin>
1759 <capabilities>
1760 <required id="can_suspend"></required>
1761 </capabilities>
1762 <parameters>
1763 <param id="request_count">
1764 <jint min="0"/>
1765 <description>
1766 The number of threads to resume.
1767 </description>
1768 </param>
1769 <param id="request_list">
1770 <inbuf incount="request_count"><jthread/></inbuf>
1771 <description>
1772 The threads to resume.
1773 </description>
1774 </param>
1775 <param id="results">
1776 <outbuf incount="request_count"><enum>jvmtiError</enum></outbuf>
1777 <description>
1778 An agent supplied array of
1779 <paramlink id="request_count"></paramlink> elements.
1780 On return, filled with the error code for
1781 the resume of the corresponding thread.
1782 The error code will be
1783 <errorlink id="JVMTI_ERROR_NONE"></errorlink>
1784 if the thread was suspended by this call.
1785 Possible error codes are those specified
1786 for <functionlink id="ResumeThread"></functionlink>.
1787 </description>
1788 </param>
1789 </parameters>
1790 <errors>
1791 </errors>
1792 </function>
1793
1794 <function id="StopThread" num="7">
1795 <synopsis>Stop Thread</synopsis>
1796 <description>
1797 Send the specified asynchronous exception to the specified thread.
1798 Normally, this function is used to kill the specified thread with an
1799 instance of the exception <code>ThreadDeath</code>, similar to
1800 <code>java.lang.Thread.stop</code>.
1801 </description>
1802 <origin>jvmdi</origin>
1803 <capabilities>
1804 <required id="can_signal_thread"></required>
1805 </capabilities>
1806 <parameters>
1807 <param id="thread">
1808 <jthread/>
1809 <description>
1810 The thread to stop.
1811 </description>
1812 </param>
1813 <param id="exception">
1814 <jobject/>
1815 <description>
1816 The asynchronous exception object.
1817 </description>
1818 </param>
1819 </parameters>
1820 <errors>
1821 </errors>
1822 </function>
1823
1824 <function id="InterruptThread" num="8">
1825 <synopsis>Interrupt Thread</synopsis>
1826 <description>
1827 Interrupt the specified thread
1828 (similar to <code>java.lang.Thread.interrupt</code>).
1829 </description>
1830 <origin>jvmdi</origin>
1831 <capabilities>
1832 <required id="can_signal_thread"></required>
1833 </capabilities>
1834 <parameters>
1835 <param id="thread">
1836 <jthread impl="noconvert"/>
1837 <description>
1838 The thread to interrupt.
1839 </description>
1840 </param>
1841 </parameters>
1842 <errors>
1843 </errors>
1844 </function>
1845
1846 <function id="GetThreadInfo" num="9">
1847 <synopsis>Get Thread Info</synopsis>
1848 <typedef id="jvmtiThreadInfo" label="Thread information structure">
1849 <field id="name">
1850 <allocfieldbuf><char/></allocfieldbuf>
1851 <description>
1852 The thread name, encoded as a
1853 <internallink id="mUTF">modified UTF-8</internallink> string.
1854 </description>
1855 </field>
1856 <field id="priority">
1857 <jint/>
1858 <description>
1859 The thread priority. See the thread priority constants:
1860 <datalink id="jvmtiThreadPriority"></datalink>.
1861 </description>
1862 </field>
1863 <field id="is_daemon">
1864 <jboolean/>
1865 <description>
1866 Is this a daemon thread?
1867 </description>
1868 </field>
1869 <field id="thread_group">
1870 <jthreadGroup/>
1871 <description>
1872 The thread group to which this thread belongs.
1873 <code>NULL</code> if the thread has died.
1874 </description>
1875 </field>
1876 <field id="context_class_loader">
1877 <jobject/>
1878 <description>
1879 The context class loader associated with this thread.
1880 </description>
1881 </field>
1882 </typedef>
1883 <description>
1884 Get thread information. The fields of the <datalink id="jvmtiThreadInfo"/> structure
1885 are filled in with details of the specified thread.
1886 </description>
1887 <origin>jvmdi</origin>
1888 <capabilities>
1889 </capabilities>
1890 <parameters>
1891 <param id="thread">
1892 <jthread null="current" impl="noconvert" started="maybe"/>
1893 <description>
1894 The thread to query.
1895 </description>
1896 </param>
1897 <param id="info_ptr">
1898 <outptr><struct>jvmtiThreadInfo</struct></outptr>
1899 <description>
1900 On return, filled with information describing the specified thread.
1901 </description>
1902 </param>
1903 </parameters>
1904 <errors>
1905 </errors>
1906 </function>
1907
1908 <function id="GetOwnedMonitorInfo" num="10">
1909 <synopsis>Get Owned Monitor Info</synopsis>
1910 <description>
1911 Get information about the monitors owned by the
1912 specified thread.
1913 </description>
1914 <origin>jvmdiClone</origin>
1915 <capabilities>
1916 <required id="can_get_owned_monitor_info"></required>
1917 </capabilities>
1918 <parameters>
1919 <param id="thread">
1920 <jthread null="current"/>
1921 <description>
1922 The thread to query.
1923 </description>
1924 </param>
1925 <param id="owned_monitor_count_ptr">
1926 <outptr><jint/></outptr>
1927 <description>
1928 The number of monitors returned.
1929 </description>
1930 </param>
1931 <param id="owned_monitors_ptr">
1932 <allocbuf outcount="owned_monitor_count_ptr"><jobject/></allocbuf>
1933 <description>
1934 The array of owned monitors.
1935 </description>
1936 </param>
1937 </parameters>
1938 <errors>
1939 </errors>
1940 </function>
1941
1942 <function id="GetOwnedMonitorStackDepthInfo" num="153" since="1.1">
1943 <synopsis>Get Owned Monitor Stack Depth Info</synopsis>
1944 <typedef id="jvmtiMonitorStackDepthInfo"
1945 label="Monitor stack depth information structure">
1946 <field id="monitor">
1947 <jobject/>
1948 <description>
1949 The owned monitor.
1950 </description>
1951 </field>
1952 <field id="stack_depth">
1953 <jint/>
1954 <description>
1955 The stack depth. Corresponds to the stack depth used in the
1956 <internallink id="stack">Stack Frame functions</internallink>.
1957 That is, zero is the current frame, one is the frame which
1958 called the current frame. And it is negative one if the
1959 implementation cannot determine the stack depth (e.g., for
1960 monitors acquired by JNI <code>MonitorEnter</code>).
1961 </description>
1962 </field>
1963 </typedef>
1964 <description>
1965 Get information about the monitors owned by the
1966 specified thread and the depth of the stack frame which locked them.
1967 </description>
1968 <origin>new</origin>
1969 <capabilities>
1970 <required id="can_get_owned_monitor_stack_depth_info"></required>
1971 </capabilities>
1972 <parameters>
1973 <param id="thread">
1974 <jthread null="current"/>
1975 <description>
1976 The thread to query.
1977 </description>
1978 </param>
1979 <param id="monitor_info_count_ptr">
1980 <outptr><jint/></outptr>
1981 <description>
1982 The number of monitors returned.
1983 </description>
1984 </param>
1985 <param id="monitor_info_ptr">
1986 <allocbuf outcount="monitor_info_count_ptr">
1987 <struct>jvmtiMonitorStackDepthInfo</struct>
1988 </allocbuf>
1989 <description>
1990 The array of owned monitor depth information.
1991 </description>
1992 </param>
1993 </parameters>
1994 <errors>
1995 </errors>
1996 </function>
1997
1998 <function id="GetCurrentContendedMonitor" num="11">
1999 <synopsis>Get Current Contended Monitor</synopsis>
2000 <description>
2001 Get the object, if any, whose monitor the specified thread is waiting to
2002 enter or waiting to regain through <code>java.lang.Object.wait</code>.
2003 </description>
2004 <origin>jvmdi</origin>
2005 <capabilities>
2006 <required id="can_get_current_contended_monitor"></required>
2007 </capabilities>
2008 <parameters>
2009 <param id="thread">
2010 <jthread null="current"/>
2011 <description>
2012 The thread to query.
2013 </description>
2014 </param>
2015 <param id="monitor_ptr">
2016 <outptr><jobject/></outptr>
2017 <description>
2018 On return, filled with the current contended monitor, or
2019 NULL if there is none.
2020 </description>
2021 </param>
2022 </parameters>
2023 <errors>
2024 </errors>
2025 </function>
2026
2027 <callback id="jvmtiStartFunction">
2028 <void/>
2029 <synopsis>Agent Start Function</synopsis>
2030 <description>
2031 Agent supplied callback function.
2032 This function is the entry point for an agent thread
2033 started with
2034 <functionlink id="RunAgentThread"></functionlink>.
2035 </description>
2036 <parameters>
2037 <param id="jvmti_env">
2038 <outptr>
2039 <struct>jvmtiEnv</struct>
2040 </outptr>
2041 <description>
2042 The <jvmti/> environment.
2043 </description>
2044 </param>
2045 <param id="jni_env">
2046 <outptr>
2047 <struct>JNIEnv</struct>
2048 </outptr>
2049 <description>
2050 The JNI environment.
2051 </description>
2052 </param>
2053 <param id="arg">
2054 <outptr>
2055 <void/>
2056 </outptr>
2057 <description>
2058 The <code>arg</code> parameter passed to
2059 <functionlink id="RunAgentThread"></functionlink>.
2060 </description>
2061 </param>
2062 </parameters>
2063 </callback>
2064
2065 <function id="RunAgentThread" num="12">
2066 <synopsis>Run Agent Thread</synopsis>
2067 <description>
2068 Starts the execution of an agent thread. with the specified native function.
2069 The parameter <paramlink id="arg"></paramlink> is forwarded on to the
2070 <functionlink id="jvmtiStartFunction">start function</functionlink>
2071 (specified with <paramlink id="proc"></paramlink>) as its single argument.
2072 This function allows the creation of agent threads
2073 for handling communication with another process or for handling events
2074 without the need to load a special subclass of <code>java.lang.Thread</code> or
2075 implementer of <code>java.lang.Runnable</code>.
2076 Instead, the created thread can run entirely in native code.
2077 However, the created thread does require a newly created instance
2078 of <code>java.lang.Thread</code> (referenced by the argument <code>thread</code>) to
2079 which it will be associated.
2080 The thread object can be created with JNI calls.
2081 <p/>
2082 The following common thread priorities are provided for your convenience:
2083 <constants id="jvmtiThreadPriority" label="Thread Priority Constants" kind="const">
2084 <constant id="JVMTI_THREAD_MIN_PRIORITY" num="1">
2085 Minimum possible thread priority
2086 </constant>
2087 <constant id="JVMTI_THREAD_NORM_PRIORITY" num="5">
2088 Normal thread priority
2089 </constant>
2090 <constant id="JVMTI_THREAD_MAX_PRIORITY" num="10">
2091 Maximum possible thread priority
2092 </constant>
2093 </constants>
2094 <p/>
2095 The new thread is started as a daemon thread with the specified
2096 <paramlink id="priority"></paramlink>.
2097 If enabled, a <eventlink id="ThreadStart"/> event will be sent.
2098 <p/>
2099 Since the thread has been started, the thread will be live when this function
2100 returns, unless the thread has died immediately.
2101 <p/>
2102 The thread group of the thread is ignored -- specifically, the thread is not
2103 added to the thread group and the thread is not seen on queries of the thread
2104 group at either the Java programming language or <jvmti/> levels.
2105 <p/>
2106 The thread is not visible to Java programming language queries but is
2107 included in <jvmti/> queries (for example,
2108 <functionlink id="GetAllThreads"/> and
2109 <functionlink id="GetAllStackTraces"/>).
2110 <p/>
2111 Upon execution of <code>proc</code>, the new thread will be attached to the
2112 VM -- see the JNI documentation on
2113 <externallink id="jni/invocation.html#attaching-to-the-vm"
2114 >Attaching to the VM</externallink>.
2115 </description>
2116 <origin>jvmdiClone</origin>
2117 <capabilities>
2118 </capabilities>
2119 <parameters>
2120 <param id="thread">
2121 <jthread impl="noconvert" started="no"/>
2122 <description>
2123 The thread to run.
2124 </description>
2125 </param>
2126 <param id="proc">
2127 <ptrtype>
2128 <struct>jvmtiStartFunction</struct>
2129 </ptrtype>
2130 <description>
2131 The start function.
2132 </description>
2133 </param>
2134 <param id="arg">
2135 <inbuf>
2136 <void/>
2137 <nullok><code>NULL</code> is passed to the start function</nullok>
2138 </inbuf>
2139 <description>
2140 The argument to the start function.
2141 </description>
2142 </param>
2143 <param id="priority">
2144 <jint/>
2145 <description>
2146 The priority of the started thread. Any thread
2147 priority allowed by <code>java.lang.Thread.setPriority</code> can be used including
2148 those in <datalink id="jvmtiThreadPriority"></datalink>.
2149 </description>
2150 </param>
2151 </parameters>
2152 <errors>
2153 <error id="JVMTI_ERROR_INVALID_PRIORITY">
2154 <paramlink id="priority"/> is less than
2155 <datalink id="JVMTI_THREAD_MIN_PRIORITY"/>
2156 or greater than
2157 <datalink id="JVMTI_THREAD_MAX_PRIORITY"/>
2158 </error>
2159 </errors>
2160 </function>
2161
2162 <function id="SetThreadLocalStorage" jkernel="yes" impl="notrace" phase="start" num="103">
2163 <synopsis>Set Thread Local Storage</synopsis>
2164 <description>
2165 The VM stores a pointer value associated with each environment-thread
2166 pair. This pointer value is called <i>thread-local storage</i>.
2167 This value is <code>NULL</code> unless set with this function.
2168 Agents can allocate memory in which they store thread specific
2169 information. By setting thread-local storage it can then be
2170 accessed with
2171 <functionlink id="GetThreadLocalStorage"></functionlink>.
2172 <p/>
2173 This function is called by the agent to set the value of the <jvmti/>
2174 thread-local storage. <jvmti/> supplies to the agent a pointer-size
2175 thread-local storage that can be used to record per-thread
2176 information.
2177 </description>
2178 <origin>jvmpi</origin>
2179 <capabilities>
2180 </capabilities>
2181 <parameters>
2182 <param id="thread">
2183 <jthread null="current"/>
2184 <description>
2185 Store to this thread.
2186 </description>
2187 </param>
2188 <param id="data">
2189 <inbuf>
2190 <void/>
2191 <nullok>value is set to <code>NULL</code></nullok>
2192 </inbuf>
2193 <description>
2194 The value to be entered into the thread-local storage.
2195 </description>
2196 </param>
2197 </parameters>
2198 <errors>
2199 </errors>
2200 </function>
2201
2202 <function id="GetThreadLocalStorage" jkernel="yes" impl="innative notrace" phase="start" num="102">
2203 <synopsis>Get Thread Local Storage</synopsis>
2204 <description>
2205 Called by the agent to get the value of the <jvmti/> thread-local
2206 storage.
2207 </description>
2208 <origin>jvmpi</origin>
2209 <capabilities>
2210 </capabilities>
2211 <parameters>
2212 <param id="thread">
2213 <jthread null="current" impl="noconvert"/>
2214 <description>
2215 Retrieve from this thread.
2216 </description>
2217 </param>
2218 <param id="data_ptr">
2219 <agentbuf><void/></agentbuf>
2220 <description>
2221 Pointer through which the value of the thread local
2222 storage is returned.
2223 If thread-local storage has not been set with
2224 <functionlink id="SetThreadLocalStorage"></functionlink> the returned
2225 pointer is <code>NULL</code>.
2226 </description>
2227 </param>
2228 </parameters>
2229 <errors>
2230 </errors>
2231 </function>
2232
2233 </category>
2234
2235 <category id="thread_groups" label="Thread Group">
2236 <intro>
2237 </intro>
2238
2239 <function id="GetTopThreadGroups" num="13">
2240 <synopsis>Get Top Thread Groups</synopsis>
2241 <description>
2242 Return all top-level (parentless) thread groups in the VM.
2243 </description>
2244 <origin>jvmdi</origin>
2245 <capabilities>
2246 </capabilities>
2247 <parameters>
2248 <param id="group_count_ptr">
2249 <outptr><jint/></outptr>
2250 <description>
2251 On return, points to the number of top-level thread groups.
2252 </description>
2253 </param>
2254 <param id="groups_ptr">
2255 <allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf>
2256 <description>
2257 On return, refers to a pointer to the top-level thread group array.
2258 </description>
2259 </param>
2260 </parameters>
2261 <errors>
2262 </errors>
2263 </function>
2264
2265 <function id="GetThreadGroupInfo" num="14">
2266 <synopsis>Get Thread Group Info</synopsis>
2267 <typedef id="jvmtiThreadGroupInfo" label="Thread group information structure">
2268 <field id="parent">
2269 <jthreadGroup/>
2270 <description>
2271 The parent thread group.
2272 </description>
2273 </field>
2274 <field id="name">
2275 <allocfieldbuf><char/></allocfieldbuf>
2276 <description>
2277 The thread group's name, encoded as a
2278 <internallink id="mUTF">modified UTF-8</internallink> string.
2279 </description>
2280 </field>
2281 <field id="max_priority">
2282 <jint/>
2283 <description>
2284 The maximum priority for this thread group.
2285 </description>
2286 </field>
2287 <field id="is_daemon">
2288 <jboolean/>
2289 <description>
2290 Is this a daemon thread group?
2291 </description>
2292 </field>
2293 </typedef>
2294 <description>
2295 Get information about the thread group. The fields of the
2296 <functionlink id="jvmtiThreadGroupInfo"></functionlink> structure
2297 are filled in with details of the specified thread group.
2298 </description>
2299 <origin>jvmdi</origin>
2300 <capabilities>
2301 </capabilities>
2302 <parameters>
2303 <param id="group">
2304 <jthreadGroup/>
2305 <description>
2306 The thread group to query.
2307 </description>
2308 </param>
2309 <param id="info_ptr">
2310 <outptr><struct>jvmtiThreadGroupInfo</struct></outptr>
2311 <description>
2312 On return, filled with information describing the specified
2313 thread group.
2314 </description>
2315 </param>
2316 </parameters>
2317 <errors>
2318 </errors>
2319 </function>
2320
2321 <function id="GetThreadGroupChildren" num="15">
2322 <synopsis>Get Thread Group Children</synopsis>
2323 <description>
2324 Get the live threads and active subgroups in this thread group.
2325 </description>
2326 <origin>jvmdi</origin>
2327 <capabilities>
2328 </capabilities>
2329 <parameters>
2330 <param id="group">
2331 <jthreadGroup/>
2332 <description>
2333 The group to query.
2334 </description>
2335 </param>
2336 <param id="thread_count_ptr">
2337 <outptr><jint/></outptr>
2338 <description>
2339 On return, points to the number of live threads in this thread group.
2340 </description>
2341 </param>
2342 <param id="threads_ptr">
2343 <allocbuf outcount="thread_count_ptr"><jthread/></allocbuf>
2344 <description>
2345 On return, points to an array of the live threads in this thread group.
2346 </description>
2347 </param>
2348 <param id="group_count_ptr">
2349 <outptr><jint/></outptr>
2350 <description>
2351 On return, points to the number of active child thread groups
2352 </description>
2353 </param>
2354 <param id="groups_ptr">
2355 <allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf>
2356 <description>
2357 On return, points to an array of the active child thread groups.
2358 </description>
2359 </param>
2360 </parameters>
2361 <errors>
2362 </errors>
2363 </function>
2364 </category>
2365
2366 <category id="stack" label="Stack Frame">
2367 <intro>
2368 These functions provide information about the stack of a thread.
2369 Stack frames are referenced by depth.
2370 The frame at depth zero is the current frame.
2371 <p/>
2372 Stack frames are as described in
2373 <vmspec chapter="3.6"/>,
2374 That is, they correspond to method
2375 invocations (including native methods) but do not correspond to platform native or
2376 VM internal frames.
2377 <p/>
2378 A <jvmti/> implementation may use method invocations to launch a thread and
2379 the corresponding frames may be included in the stack as presented by these functions --
2380 that is, there may be frames shown
2381 deeper than <code>main()</code> and <code>run()</code>.
2382 However this presentation must be consistent across all <jvmti/> functionality which
2383 uses stack frames or stack depth.
2384 </intro>
2385
2386 <typedef id="jvmtiFrameInfo" label="Stack frame information structure">
2387 <description>
2388 Information about a stack frame is returned in this structure.
2389 </description>
2390 <field id="method">
2391 <jmethodID/>
2392 <description>
2393 The method executing in this frame.
2394 </description>
2395 </field>
2396 <field id="location">
2397 <jlocation/>
2398 <description>
2399 The index of the instruction executing in this frame.
2400 <code>-1</code> if the frame is executing a native method.
2401 </description>
2402 </field>
2403 </typedef>
2404
2405 <typedef id="jvmtiStackInfo" label="Stack information structure">
2406 <description>
2407 Information about a set of stack frames is returned in this structure.
2408 </description>
2409 <field id="thread">
2410 <jthread/>
2411 <description>
2412 On return, the thread traced.
2413 </description>
2414 </field>
2415 <field id="state">
2416 <jint/>
2417 <description>
2418 On return, the thread state. See <functionlink id="GetThreadState"></functionlink>.
2419 </description>
2420 </field>
2421 <field id="frame_buffer">
2422 <outbuf incount="max_frame_count">
2423 <struct>jvmtiFrameInfo</struct>
2424 </outbuf>
2425 <description>
2426 On return, this agent allocated buffer is filled
2427 with stack frame information.
2428 </description>
2429 </field>
2430 <field id="frame_count">
2431 <jint/>
2432 <description>
2433 On return, the number of records filled into
2434 <code>frame_buffer</code>.
2435 This will be
2436 min(<code>max_frame_count</code>, <i>stackDepth</i>).
2437 </description>
2438 </field>
2439 </typedef>
2440
2441 <function id="GetStackTrace" num="104">
2442 <synopsis>Get Stack Trace</synopsis>
2443 <description>
2444 Get information about the stack of a thread.
2445 If <paramlink id="max_frame_count"></paramlink> is less than the depth of the stack,
2446 the <paramlink id="max_frame_count"></paramlink> topmost frames are returned,
2447 otherwise the entire stack is returned.
2448 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2449 <p/>
2450 The following example causes up to five of the topmost frames
2451 to be returned and (if there are any frames) the currently
2452 executing method name to be printed.
2453 <example>
2454 jvmtiFrameInfo frames[5];
2455 jint count;
2456 jvmtiError err;
2457
2458 err = (*jvmti)->GetStackTrace(jvmti, aThread, 0, 5,
2459 frames, &count);
2460 if (err == JVMTI_ERROR_NONE && count >= 1) {
2461 char *methodName;
2462 err = (*jvmti)->GetMethodName(jvmti, frames[0].method,
2463 &methodName, NULL, NULL);
2464 if (err == JVMTI_ERROR_NONE) {
2465 printf("Executing method: %s", methodName);
2466 }
2467 }
2468 </example>
2469 <todo>
2470 check example code.
2471 </todo>
2472 <p/>
2473 The <paramlink id="thread"></paramlink> need not be suspended
2474 to call this function.
2475 <p/>
2476 The <functionlink id="GetLineNumberTable"></functionlink>
2477 function can be used to map locations to line numbers. Note that
2478 this mapping can be done lazily.
2479 </description>
2480 <origin>jvmpi</origin>
2481 <capabilities>
2482 </capabilities>
2483 <parameters>
2484 <param id="thread">
2485 <jthread null="current"/>
2486 <description>
2487 Fetch the stack trace of this thread.
2488 </description>
2489 </param>
2490 <param id="start_depth">
2491 <jint/>
2492 <description>
2493 Begin retrieving frames at this depth.
2494 If non-negative, count from the current frame,
2495 the first frame retrieved is at depth <code>start_depth</code>.
2496 For example, if zero, start from the current frame; if one, start from the
2497 caller of the current frame; if two, start from the caller of the
2498 caller of the current frame; and so on.
2499 If negative, count from below the oldest frame,
2500 the first frame retrieved is at depth <i>stackDepth</i><code> + start_depth</code>,
2501 where <i>stackDepth</i> is the count of frames on the stack.
2502 For example, if negative one, only the oldest frame is retrieved;
2503 if negative two, start from the frame called by the oldest frame.
2504 </description>
2505 </param>
2506 <param id="max_frame_count">
2507 <jint min="0"/>
2508 <description>
2509 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve.
2510 </description>
2511 </param>
2512 <param id="frame_buffer">
2513 <outbuf incount="max_frame_count" outcount="count_ptr">
2514 <struct>jvmtiFrameInfo</struct>
2515 </outbuf>
2516 <description>
2517 On return, this agent allocated buffer is filled
2518 with stack frame information.
2519 </description>
2520 </param>
2521 <param id="count_ptr">
2522 <outptr><jint/></outptr>
2523 <description>
2524 On return, points to the number of records filled in.
2525 For non-negative <code>start_depth</code>, this will be
2526 min(<code>max_frame_count</code>, <i>stackDepth</i><code> - start_depth</code>).
2527 For negative <code>start_depth</code>, this will be
2528 min(<code>max_frame_count</code>, <code>-start_depth</code>).
2529 </description>
2530 </param>
2531 </parameters>
2532 <errors>
2533 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
2534 <paramlink id="start_depth"/> is positive and greater than or equal to <i>stackDepth</i>.
2535 Or <paramlink id="start_depth"/> is negative and less than <i>-stackDepth</i>.
2536 </error>
2537 </errors>
2538 </function>
2539
2540
2541 <function id="GetAllStackTraces" num="100">
2542 <synopsis>Get All Stack Traces</synopsis>
2543 <description>
2544 Get information about the stacks of all live threads
2545 (including <internallink id="RunAgentThread">agent threads</internallink>).
2546 If <paramlink id="max_frame_count"/> is less than the depth of a stack,
2547 the <paramlink id="max_frame_count"/> topmost frames are returned for that thread,
2548 otherwise the entire stack is returned.
2549 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2550 <p/>
2551 All stacks are collected simultaneously, that is, no changes will occur to the
2552 thread state or stacks between the sampling of one thread and the next.
2553 The threads need not be suspended.
2554
2555 <example>
2556 jvmtiStackInfo *stack_info;
2557 jint thread_count;
2558 int ti;
2559 jvmtiError err;
2560
2561 err = (*jvmti)->GetAllStackTraces(jvmti, MAX_FRAMES, &stack_info, &thread_count);
2562 if (err != JVMTI_ERROR_NONE) {
2563 ...
2564 }
2565 for (ti = 0; ti < thread_count; ++ti) {
2566 jvmtiStackInfo *infop = &stack_info[ti];
2567 jthread thread = infop->thread;
2568 jint state = infop->state;
2569 jvmtiFrameInfo *frames = infop->frame_buffer;
2570 int fi;
2571
2572 myThreadAndStatePrinter(thread, state);
2573 for (fi = 0; fi < infop->frame_count; fi++) {
2574 myFramePrinter(frames[fi].method, frames[fi].location);
2575 }
2576 }
2577 /* this one Deallocate call frees all data allocated by GetAllStackTraces */
2578 err = (*jvmti)->Deallocate(jvmti, stack_info);
2579 </example>
2580 <todo>
2581 check example code.
2582 </todo>
2583
2584 </description>
2585 <origin>new</origin>
2586 <capabilities>
2587 </capabilities>
2588 <parameters>
2589 <param id="max_frame_count">
2590 <jint min="0"/>
2591 <description>
2592 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread.
2593 </description>
2594 </param>
2595 <param id="stack_info_ptr">
2596 <allocbuf>
2597 <struct>jvmtiStackInfo</struct>
2598 </allocbuf>
2599 <description>
2600 On return, this buffer is filled
2601 with stack information for each thread.
2602 The number of <datalink id="jvmtiStackInfo"/> records is determined
2603 by <paramlink id="thread_count_ptr"/>.
2604 <p/>
2605 Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/>
2606 buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>.
2607 These buffers must not be separately deallocated.
2608 </description>
2609 </param>
2610 <param id="thread_count_ptr">
2611 <outptr><jint/></outptr>
2612 <description>
2613 The number of threads traced.
2614 </description>
2615 </param>
2616 </parameters>
2617 <errors>
2618 </errors>
2619 </function>
2620
2621 <function id="GetThreadListStackTraces" num="101">
2622 <synopsis>Get Thread List Stack Traces</synopsis>
2623 <description>
2624 Get information about the stacks of the supplied threads.
2625 If <paramlink id="max_frame_count"/> is less than the depth of a stack,
2626 the <paramlink id="max_frame_count"/> topmost frames are returned for that thread,
2627 otherwise the entire stack is returned.
2628 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2629 <p/>
2630 All stacks are collected simultaneously, that is, no changes will occur to the
2631 thread state or stacks between the sampling one thread and the next.
2632 The threads need not be suspended.
2633 <p/>
2634 If a thread has not yet started or terminates before the stack information is collected,
2635 a zero length stack (<datalink id="jvmtiStackInfo.frame_count"/> will be zero)
2636 will be returned and the thread <datalink id="jvmtiStackInfo.state"/> can be checked.
2637 <p/>
2638 See the example for the similar function
2639 <functionlink id="GetAllStackTraces"/>.
2640 </description>
2641 <origin>new</origin>
2642 <capabilities>
2643 </capabilities>
2644 <parameters>
2645 <param id="thread_count">
2646 <jint min="0"/>
2647 <description>
2648 The number of threads to trace.
2649 </description>
2650 </param>
2651 <param id="thread_list">
2652 <inbuf incount="thread_count"><jthread/></inbuf>
2653 <description>
2654 The list of threads to trace.
2655 </description>
2656 </param>
2657 <param id="max_frame_count">
2658 <jint min="0"/>
2659 <description>
2660 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread.
2661 </description>
2662 </param>
2663 <param id="stack_info_ptr">
2664 <allocbuf outcount="thread_count">
2665 <struct>jvmtiStackInfo</struct>
2666 </allocbuf>
2667 <description>
2668 On return, this buffer is filled
2669 with stack information for each thread.
2670 The number of <datalink id="jvmtiStackInfo"/> records is determined
2671 by <paramlink id="thread_count"/>.
2672 <p/>
2673 Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/>
2674 buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>.
2675 These buffers must not be separately deallocated.
2676 </description>
2677 </param>
2678 </parameters>
2679 <errors>
2680 <error id="JVMTI_ERROR_INVALID_THREAD">
2681 An element in <paramlink id="thread_list"/> is not a thread object.
2682 </error>
2683 </errors>
2684 </function>
2685
2686 <elide>
2687 <function id="AsyncGetStackTrace" num="1000">
2688 <synopsis>Get Stack Trace--Asynchronous</synopsis>
2689 <description>
2690 Get information about the entire stack of a thread (or a sub-section of it).
2691 This is the asynchronous version of <functionlink id="GetStackTrace"></functionlink>
2692 and is reentrant and safe to call
2693 from asynchronous signal handlers.
2694 The stack trace is returned only for the calling thread.
2695 <p/>
2696 The <functionlink id="GetLineNumberTable"></functionlink>
2697 function can be used to map locations to line numbers. Note that
2698 this mapping can be done lazily.
2699 </description>
2700 <origin>jvmpi</origin>
2701 <capabilities>
2702 <required id="can_get_async_stack_trace"></required>
2703 <capability id="can_show_JVM_spec_async_frames">
2704 If <code>false</code>,
2705 <paramlink id="use_java_stack"></paramlink>
2706 must be <code>false</code>.
2707 </capability>
2708 </capabilities>
2709 <parameters>
2710 <param id="use_java_stack">
2711 <jboolean/>
2712 <description>
2713 Return the stack showing <vmspec/>
2714 model of the stack;
2715 otherwise, show the internal representation of the stack with
2716 inlined and optimized methods missing. If the virtual machine
2717 is using the <i>Java Virtual Machine Specification</i> stack model
2718 internally, this flag is ignored.
2719 </description>
2720 </param>
2721 <param id="max_count">
2722 <jint min="0"/>
2723 <description>
2724 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve.
2725 Retrieve this many unless the stack depth is less than <code>max_count</code>.
2726 </description>
2727 </param>
2728 <param id="frame_buffer">
2729 <outbuf incount="max_count" outcount="count_ptr">
2730 <struct>jvmtiFrameInfo</struct>
2731 <nullok>this information is not returned</nullok>
2732 </outbuf>
2733 <description>
2734 The agent passes in a buffer
2735 large enough to hold <code>max_count</code> records of
2736 <datalink id="jvmtiFrameInfo"></datalink>. This buffer must be
2737 pre-allocated by the agent.
2738 </description>
2739 </param>
2740 <param id="count_ptr">
2741 <outptr><jint/></outptr>
2742 <description>
2743 On return, points to the number of records filled in..
2744 </description>
2745 </param>
2746 </parameters>
2747 <errors>
2748 <error id="JVMTI_ERROR_UNATTACHED_THREAD">
2749 The thread being used to call this function is not attached
2750 to the virtual machine. Calls must be made from attached threads.
2751 </error>
2752 </errors>
2753 </function>
2754 </elide>
2755
2756 <function id="GetFrameCount" num="16">
2757 <synopsis>Get Frame Count</synopsis>
2758 <description>
2759 Get the number of frames currently in the specified thread's call stack.
2760 <p/>
2761 If this function is called for a thread actively executing bytecodes (for example,
2762 not the current thread and not suspended), the information returned is transient.
2763 </description>
2764 <origin>jvmdi</origin>
2765 <capabilities>
2766 </capabilities>
2767 <parameters>
2768 <param id="thread">
2769 <jthread null="current"/>
2770 <description>
2771 The thread to query.
2772 </description>
2773 </param>
2774 <param id="count_ptr">
2775 <outptr><jint/></outptr>
2776 <description>
2777 On return, points to the number of frames in the call stack.
2778 </description>
2779 </param>
2780 </parameters>
2781 <errors>
2782 </errors>
2783 </function>
2784
2785 <function id="PopFrame" num="80">
2786 <synopsis>Pop Frame</synopsis>
2787 <description>
2788 Pop the current frame of <code>thread</code>'s stack.
2789 Popping a frame takes you to the previous frame.
2790 When the thread is resumed, the execution
2791 state of the thread is reset to the state
2792 immediately before the called method was invoked.
2793 That is (using <vmspec/> terminology):
2794 <ul>
2795 <li>the current frame is discarded as the previous frame becomes the current one</li>
2796 <li>the operand stack is restored--the argument values are added back
2797 and if the invoke was not <code>invokestatic</code>,
2798 <code>objectref</code> is added back as well</li>
2799 <li>the Java virtual machine PC is restored to the opcode
2800 of the invoke instruction</li>
2801 </ul>
2802 Note however, that any changes to the arguments, which
2803 occurred in the called method, remain;
2804 when execution continues, the first instruction to
2805 execute will be the invoke.
2806 <p/>
2807 Between calling <code>PopFrame</code> and resuming the
2808 thread the state of the stack is undefined.
2809 To pop frames beyond the first,
2810 these three steps must be repeated:
2811 <ul>
2812 <li>suspend the thread via an event (step, breakpoint, ...)</li>
2813 <li>call <code>PopFrame</code></li>
2814 <li>resume the thread</li>
2815 </ul>
2816 <p/>
2817 A lock acquired by calling the called method
2818 (if it is a <code>synchronized</code> method)
2819 and locks acquired by entering <code>synchronized</code>
2820 blocks within the called method are released.
2821 Note: this does not apply to native locks or
2822 <code>java.util.concurrent.locks</code> locks.
2823 <p/>
2824 Finally blocks are not executed.
2825 <p/>
2826 Changes to global state are not addressed and thus remain changed.
2827 <p/>
2828 The specified thread must be suspended or must be the current thread.
2829 <p/>
2830 Both the called method and calling method must be non-native Java programming
2831 language methods.
2832 <p/>
2833 No <jvmti/> events are generated by this function.
2834 </description>
2835 <origin>jvmdi</origin>
2836 <capabilities>
2837 <required id="can_pop_frame"></required>
2838 </capabilities>
2839 <parameters>
2840 <param id="thread">
2841 <jthread/>
2842 <description>
2843 The thread whose current frame is to be popped.
2844 </description>
2845 </param>
2846 </parameters>
2847 <errors>
2848 <error id="JVMTI_ERROR_OPAQUE_FRAME">
2849 Called or calling method is a native method.
2850 The implementation is unable to pop this frame.
2851 </error>
2852 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2853 Thread was not suspended and was not the current thread.
2854 </error>
2855 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
2856 There are less than two stack frames on the call stack.
2857 </error>
2858 </errors>
2859 </function>
2860
2861 <function id="GetFrameLocation" num="19">
2862 <synopsis>Get Frame Location</synopsis>
2863 <description>
2864 <p/>
2865 For a Java programming language frame, return the location of the instruction
2866 currently executing.
2867 </description>
2868 <origin>jvmdiClone</origin>
2869 <capabilities>
2870 </capabilities>
2871 <parameters>
2872 <param id="thread">
2873 <jthread null="current" frame="frame"/>
2874 <description>
2875 The thread of the frame to query.
2876 </description>
2877 </param>
2878 <param id="depth">
2879 <jframeID thread="thread"/>
2880 <description>
2881 The depth of the frame to query.
2882 </description>
2883 </param>
2884 <param id="method_ptr">
2885 <outptr><jmethodID/></outptr>
2886 <description>
2887 On return, points to the method for the current location.
2888 </description>
2889 </param>
2890 <param id="location_ptr">
2891 <outptr><jlocation/></outptr>
2892 <description>
2893 On return, points to the index of the currently
2894 executing instruction.
2895 Is set to <code>-1</code> if the frame is executing
2896 a native method.
2897 </description>
2898 </param>
2899 </parameters>
2900 <errors>
2901 </errors>
2902 </function>
2903
2904 <function id="NotifyFramePop" num="20">
2905 <synopsis>Notify Frame Pop</synopsis>
2906 <description>
2907 When the frame that is currently at <paramlink id="depth"></paramlink>
2908 is popped from the stack, generate a
2909 <eventlink id="FramePop"></eventlink> event. See the
2910 <eventlink id="FramePop"></eventlink> event for details.
2911 Only frames corresponding to non-native Java programming language
2912 methods can receive notification.
2913 <p/>
2914 The specified thread must be suspended or must be the current thread.
2915 </description>
2916 <origin>jvmdi</origin>
2917 <capabilities>
2918 <required id="can_generate_frame_pop_events"></required>
2919 </capabilities>
2920 <parameters>
2921 <param id="thread">
2922 <jthread null="current" frame="depth"/>
2923 <description>
2924 The thread of the frame for which the frame pop event will be generated.
2925 </description>
2926 </param>
2927 <param id="depth">
2928 <jframeID thread="thread"/>
2929 <description>
2930 The depth of the frame for which the frame pop event will be generated.
2931 </description>
2932 </param>
2933 </parameters>
2934 <errors>
2935 <error id="JVMTI_ERROR_OPAQUE_FRAME">
2936 The frame at <code>depth</code> is executing a
2937 native method.
2938 </error>
2939 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2940 Thread was not suspended and was not the current thread.
2941 </error>
2942 </errors>
2943 </function>
2944
2945 </category>
2946
2947 <category id="ForceEarlyReturn" label="Force Early Return">
2948 <intro>
2949 These functions allow an agent to force a method
2950 to return at any point during its execution.
2951 The method which will return early is referred to as the <i>called method</i>.
2952 The called method is the current method
2953 (as defined by
2954 <vmspec chapter="3.6"/>)
2955 for the specified thread at
2956 the time the function is called.
2957 <p/>
2958 The specified thread must be suspended or must be the current thread.
2959 The return occurs when execution of Java programming
2960 language code is resumed on this thread.
2961 Between calling one of these functions and resumption
2962 of thread execution, the state of the stack is undefined.
2963 <p/>
2964 No further instructions are executed in the called method.
2965 Specifically, finally blocks are not executed.
2966 Note: this can cause inconsistent states in the application.
2967 <p/>
2968 A lock acquired by calling the called method
2969 (if it is a <code>synchronized</code> method)
2970 and locks acquired by entering <code>synchronized</code>
2971 blocks within the called method are released.
2972 Note: this does not apply to native locks or
2973 <code>java.util.concurrent.locks</code> locks.
2974 <p/>
2975 Events, such as <eventlink id="MethodExit"></eventlink>,
2976 are generated as they would be in a normal return.
2977 <p/>
2978 The called method must be a non-native Java programming
2979 language method.
2980 Forcing return on a thread with only one frame on the
2981 stack causes the thread to exit when resumed.
2982 </intro>
2983
2984 <function id="ForceEarlyReturnObject" num="81" since="1.1">
2985 <synopsis>Force Early Return - Object</synopsis>
2986 <description>
2987 This function can be used to return from a method whose
2988 result type is <code>Object</code>
2989 or a subclass of <code>Object</code>.
2990 </description>
2991 <origin>new</origin>
2992 <capabilities>
2993 <required id="can_force_early_return"></required>
2994 </capabilities>
2995 <parameters>
2996 <param id="thread">
2997 <jthread null="current"/>
2998 <description>
2999 The thread whose current frame is to return early.
3000 </description>
3001 </param>
3002 <param id="value">
3003 <jobject/>
3004 <description>
3005 The return value for the called frame.
3006 An object or <code>NULL</code>.
3007 </description>
3008 </param>
3009 </parameters>
3010 <errors>
3011 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3012 Attempted to return early from a frame
3013 corresponding to a native method.
3014 Or the implementation is unable to provide
3015 this functionality on this frame.
3016 </error>
3017 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3018 The result type of the called method is not
3019 <code>Object</code> or a subclass of <code>Object</code>.
3020 </error>
3021 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3022 The supplied <paramlink id="value"/> is not compatible with the
3023 result type of the called method.
3024 </error>
3025 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3026 Thread was not suspended and was not the current thread.
3027 </error>
3028 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3029 There are no more frames on the call stack.
3030 </error>
3031 </errors>
3032 </function>
3033
3034 <function id="ForceEarlyReturnInt" num="82" since="1.1">
3035 <synopsis>Force Early Return - Int</synopsis>
3036 <description>
3037 This function can be used to return from a method whose
3038 result type is <code>int</code>, <code>short</code>,
3039 <code>char</code>, <code>byte</code>, or
3040 <code>boolean</code>.
3041 </description>
3042 <origin>new</origin>
3043 <capabilities>
3044 <required id="can_force_early_return"></required>
3045 </capabilities>
3046 <parameters>
3047 <param id="thread">
3048 <jthread null="current"/>
3049 <description>
3050 The thread whose current frame is to return early.
3051 </description>
3052 </param>
3053 <param id="value">
3054 <jint/>
3055 <description>
3056 The return value for the called frame.
3057 </description>
3058 </param>
3059 </parameters>
3060 <errors>
3061 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3062 Attempted to return early from a frame
3063 corresponding to a native method.
3064 Or the implementation is unable to provide
3065 this functionality on this frame.
3066 </error>
3067 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3068 The result type of the called method is not
3069 <code>int</code>, <code>short</code>,
3070 <code>char</code>, <code>byte</code>, or
3071 <code>boolean</code>.
3072 </error>
3073 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3074 Thread was not suspended and was not the current thread.
3075 </error>
3076 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3077 There are no frames on the call stack.
3078 </error>
3079 </errors>
3080 </function>
3081
3082 <function id="ForceEarlyReturnLong" num="83" since="1.1">
3083 <synopsis>Force Early Return - Long</synopsis>
3084 <description>
3085 This function can be used to return from a method whose
3086 result type is <code>long</code>.
3087 </description>
3088 <origin>new</origin>
3089 <capabilities>
3090 <required id="can_force_early_return"></required>
3091 </capabilities>
3092 <parameters>
3093 <param id="thread">
3094 <jthread null="current"/>
3095 <description>
3096 The thread whose current frame is to return early.
3097 </description>
3098 </param>
3099 <param id="value">
3100 <jlong/>
3101 <description>
3102 The return value for the called frame.
3103 </description>
3104 </param>
3105 </parameters>
3106 <errors>
3107 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3108 Attempted to return early from a frame
3109 corresponding to a native method.
3110 Or the implementation is unable to provide
3111 this functionality on this frame.
3112 </error>
3113 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3114 The result type of the called method is not <code>long</code>.
3115 </error>
3116 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3117 Thread was not suspended and was not the current thread.
3118 </error>
3119 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3120 There are no frames on the call stack.
3121 </error>
3122 </errors>
3123 </function>
3124
3125 <function id="ForceEarlyReturnFloat" num="84" since="1.1">
3126 <synopsis>Force Early Return - Float</synopsis>
3127 <description>
3128 This function can be used to return from a method whose
3129 result type is <code>float</code>.
3130 </description>
3131 <origin>new</origin>
3132 <capabilities>
3133 <required id="can_force_early_return"></required>
3134 </capabilities>
3135 <parameters>
3136 <param id="thread">
3137 <jthread null="current"/>
3138 <description>
3139 The thread whose current frame is to return early.
3140 </description>
3141 </param>
3142 <param id="value">
3143 <jfloat/>
3144 <description>
3145 The return value for the called frame.
3146 </description>
3147 </param>
3148 </parameters>
3149 <errors>
3150 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3151 Attempted to return early from a frame
3152 corresponding to a native method.
3153 Or the implementation is unable to provide
3154 this functionality on this frame.
3155 </error>
3156 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3157 The result type of the called method is not <code>float</code>.
3158 </error>
3159 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3160 Thread was not suspended and was not the current thread.
3161 </error>
3162 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3163 There are no frames on the call stack.
3164 </error>
3165 </errors>
3166 </function>
3167
3168 <function id="ForceEarlyReturnDouble" num="85" since="1.1">
3169 <synopsis>Force Early Return - Double</synopsis>
3170 <description>
3171 This function can be used to return from a method whose
3172 result type is <code>double</code>.
3173 </description>
3174 <origin>new</origin>
3175 <capabilities>
3176 <required id="can_force_early_return"></required>
3177 </capabilities>
3178 <parameters>
3179 <param id="thread">
3180 <jthread null="current"/>
3181 <description>
3182 The thread whose current frame is to return early.
3183 </description>
3184 </param>
3185 <param id="value">
3186 <jdouble/>
3187 <description>
3188 The return value for the called frame.
3189 </description>
3190 </param>
3191 </parameters>
3192 <errors>
3193 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3194 Attempted to return early from a frame corresponding to a native method.
3195 Or the implementation is unable to provide this functionality on this frame.
3196 </error>
3197 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3198 The result type of the called method is not <code>double</code>.
3199 </error>
3200 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3201 Thread was not suspended and was not the current thread.
3202 </error>
3203 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3204 There are no frames on the call stack.
3205 </error>
3206 </errors>
3207 </function>
3208
3209 <function id="ForceEarlyReturnVoid" num="86" since="1.1">
3210 <synopsis>Force Early Return - Void</synopsis>
3211 <description>
3212 This function can be used to return from a method with no result type.
3213 That is, the called method must be declared <code>void</code>.
3214 </description>
3215 <origin>new</origin>
3216 <capabilities>
3217 <required id="can_force_early_return"></required>
3218 </capabilities>
3219 <parameters>
3220 <param id="thread">
3221 <jthread null="current"/>
3222 <description>
3223 The thread whose current frame is to return early.
3224 </description>
3225 </param>
3226 </parameters>
3227 <errors>
3228 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3229 Attempted to return early from a frame
3230 corresponding to a native method.
3231 Or the implementation is unable to provide
3232 this functionality on this frame.
3233 </error>
3234 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3235 The called method has a result type.
3236 </error>
3237 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3238 Thread was not suspended and was not the current thread.
3239 </error>
3240 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3241 There are no frames on the call stack.
3242 </error>
3243 </errors>
3244 </function>
3245
3246 </category>
3247
3248 <category id="Heap" label="Heap">
3249 <intro>
3250 These functions are used to analyze the heap.
3251 Functionality includes the ability to view the objects in the
3252 heap and to tag these objects.
3253 </intro>
3254
3255 <intro id="objectTags" label="Object Tags">
3256 A <i>tag</i> is a value associated with an object.
3257 Tags are explicitly set by the agent using the
3258 <functionlink id="SetTag"></functionlink> function or by
3259 callback functions such as <functionlink id="jvmtiHeapIterationCallback"/>.
3260 <p/>
3261 Tags are local to the environment; that is, the tags of one
3262 environment are not visible in another.
3263 <p/>
3264 Tags are <code>jlong</code> values which can be used
3265 simply to mark an object or to store a pointer to more detailed
3266 information. Objects which have not been tagged have a
3267 tag of zero.
3268 Setting a tag to zero makes the object untagged.
3269 </intro>
3270
3271 <intro id="heapCallbacks" label="Heap Callback Functions">
3272 Heap functions which iterate through the heap and recursively
3273 follow object references use agent supplied callback functions
3274 to deliver the information.
3275 <p/>
3276 These heap callback functions must adhere to the following restrictions --
3277 These callbacks must not use JNI functions.
3278 These callbacks must not use <jvmti/> functions except
3279 <i>callback safe</i> functions which
3280 specifically allow such use (see the raw monitor, memory management,
3281 and environment local storage functions).
3282 <p/>
3283 An implementation may invoke a callback on an internal thread or
3284 the thread which called the iteration function.
3285 Heap callbacks are single threaded -- no more than one callback will
3286 be invoked at a time.
3287 <p/>
3288 The Heap Filter Flags can be used to prevent reporting
3289 based on the tag status of an object or its class.
3290 If no flags are set (the <code>jint</code> is zero), objects
3291 will not be filtered out.
3292
3293 <constants id="jvmtiHeapFilter" label="Heap Filter Flags" kind="bits">
3294 <constant id="JVMTI_HEAP_FILTER_TAGGED" num="0x4">
3295 Filter out tagged objects. Objects which are tagged are not included.
3296 </constant>
3297 <constant id="JVMTI_HEAP_FILTER_UNTAGGED" num="0x8">
3298 Filter out untagged objects. Objects which are not tagged are not included.
3299 </constant>
3300 <constant id="JVMTI_HEAP_FILTER_CLASS_TAGGED" num="0x10">
3301 Filter out objects with tagged classes. Objects whose class is tagged are not included.
3302 </constant>
3303 <constant id="JVMTI_HEAP_FILTER_CLASS_UNTAGGED" num="0x20">
3304 Filter out objects with untagged classes. Objects whose class is not tagged are not included.
3305 </constant>
3306 </constants>
3307
3308 <p/>
3309 The Heap Visit Control Flags are returned by the heap callbacks
3310 and can be used to abort the iteration. For the
3311 <functionlink id="jvmtiHeapReferenceCallback">Heap
3312 Reference Callback</functionlink>, it can also be used
3313 to prune the graph of traversed references
3314 (<code>JVMTI_VISIT_OBJECTS</code> is not set).
3315
3316 <constants id="jvmtiHeapVisitControl"
3317 label="Heap Visit Control Flags"
3318 kind="bits"
3319 since="1.1">
3320 <constant id="JVMTI_VISIT_OBJECTS" num="0x100">
3321 If we are visiting an object and if this callback
3322 was initiated by <functionlink id="FollowReferences"/>,
3323 traverse the references of this object.
3324 Otherwise ignored.
3325 </constant>
3326 <constant id="JVMTI_VISIT_ABORT" num="0x8000">
3327 Abort the iteration. Ignore all other bits.
3328 </constant>
3329 </constants>
3330
3331 <p/>
3332 The Heap Reference Enumeration is provided by the
3333 <functionlink id="jvmtiHeapReferenceCallback">Heap
3334 Reference Callback</functionlink> and
3335 <functionlink id="jvmtiPrimitiveFieldCallback">Primitive Field
3336 Callback</functionlink> to
3337 describe the kind of reference
3338 being reported.
3339
3340 <constants id="jvmtiHeapReferenceKind"
3341 label="Heap Reference Enumeration"
3342 kind="enum"
3343 since="1.1">
3344 <constant id="JVMTI_HEAP_REFERENCE_CLASS" num="1">
3345 Reference from an object to its class.
3346 </constant>
3347 <constant id="JVMTI_HEAP_REFERENCE_FIELD" num="2">
3348 Reference from an object to the value of one of its instance fields.
3349 </constant>
3350 <constant id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT" num="3">
3351 Reference from an array to one of its elements.
3352 </constant>
3353 <constant id="JVMTI_HEAP_REFERENCE_CLASS_LOADER" num="4">
3354 Reference from a class to its class loader.
3355 </constant>
3356 <constant id="JVMTI_HEAP_REFERENCE_SIGNERS" num="5">
3357 Reference from a class to its signers array.
3358 </constant>
3359 <constant id="JVMTI_HEAP_REFERENCE_PROTECTION_DOMAIN" num="6">
3360 Reference from a class to its protection domain.
3361 </constant>
3362 <constant id="JVMTI_HEAP_REFERENCE_INTERFACE" num="7">
3363 Reference from a class to one of its interfaces.
3364 Note: interfaces are defined via a constant pool reference,
3365 so the referenced interfaces may also be reported with a
3366 <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind.
3367 </constant>
3368 <constant id="JVMTI_HEAP_REFERENCE_STATIC_FIELD" num="8">
3369 Reference from a class to the value of one of its static fields.
3370 </constant>
3371 <constant id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL" num="9">
3372 Reference from a class to a resolved entry in the constant pool.
3373 </constant>
3374 <constant id="JVMTI_HEAP_REFERENCE_SUPERCLASS" num="10">
3375 Reference from a class to its superclass.
3376 A callback is not sent if the superclass is <code>java.lang.Object</code>.
3377 Note: loaded classes define superclasses via a constant pool
3378 reference, so the referenced superclass may also be reported with
3379 a <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind.
3380 </constant>
3381 <constant id="JVMTI_HEAP_REFERENCE_JNI_GLOBAL" num="21">
3382 Heap root reference: JNI global reference.
3383 </constant>
3384 <constant id="JVMTI_HEAP_REFERENCE_SYSTEM_CLASS" num="22">
3385 Heap root reference: System class.
3386 </constant>
3387 <constant id="JVMTI_HEAP_REFERENCE_MONITOR" num="23">
3388 Heap root reference: monitor.
3389 </constant>
3390 <constant id="JVMTI_HEAP_REFERENCE_STACK_LOCAL" num="24">
3391 Heap root reference: local variable on the stack.
3392 </constant>
3393 <constant id="JVMTI_HEAP_REFERENCE_JNI_LOCAL" num="25">
3394 Heap root reference: JNI local reference.
3395 </constant>
3396 <constant id="JVMTI_HEAP_REFERENCE_THREAD" num="26">
3397 Heap root reference: Thread.
3398 </constant>
3399 <constant id="JVMTI_HEAP_REFERENCE_OTHER" num="27">
3400 Heap root reference: other heap root reference.
3401 </constant>
3402 </constants>
3403
3404 <p/>
3405 Definitions for the single character type descriptors of
3406 primitive types.
3407
3408 <constants id="jvmtiPrimitiveType"
3409 label="Primitive Type Enumeration"
3410 kind="enum"
3411 since="1.1">
3412 <constant id="JVMTI_PRIMITIVE_TYPE_BOOLEAN" num="90">
3413 'Z' - Java programming language <code>boolean</code> - JNI <code>jboolean</code>
3414 </constant>
3415 <constant id="JVMTI_PRIMITIVE_TYPE_BYTE" num="66">
3416 'B' - Java programming language <code>byte</code> - JNI <code>jbyte</code>
3417 </constant>
3418 <constant id="JVMTI_PRIMITIVE_TYPE_CHAR" num="67">
3419 'C' - Java programming language <code>char</code> - JNI <code>jchar</code>
3420 </constant>
3421 <constant id="JVMTI_PRIMITIVE_TYPE_SHORT" num="83">
3422 'S' - Java programming language <code>short</code> - JNI <code>jshort</code>
3423 </constant>
3424 <constant id="JVMTI_PRIMITIVE_TYPE_INT" num="73">
3425 'I' - Java programming language <code>int</code> - JNI <code>jint</code>
3426 </constant>
3427 <constant id="JVMTI_PRIMITIVE_TYPE_LONG" num="74">
3428 'J' - Java programming language <code>long</code> - JNI <code>jlong</code>
3429 </constant>
3430 <constant id="JVMTI_PRIMITIVE_TYPE_FLOAT" num="70">
3431 'F' - Java programming language <code>float</code> - JNI <code>jfloat</code>
3432 </constant>
3433 <constant id="JVMTI_PRIMITIVE_TYPE_DOUBLE" num="68">
3434 'D' - Java programming language <code>double</code> - JNI <code>jdouble</code>
3435 </constant>
3436 </constants>
3437 </intro>
3438
3439 <typedef id="jvmtiHeapReferenceInfoField"
3440 label="Reference information structure for Field references"
3441 since="1.1">
3442 <description>
3443 Reference information returned for
3444 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> and
3445 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references.
3446 </description>
3447 <field id="index">
3448 <jint/>
3449 <description>
3450 For <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>, the
3451 referrer object is not a class or an interface.
3452 In this case, <code>index</code> is the index of the field
3453 in the class of the referrer object.
3454 This class is referred to below as <i>C</i>.
3455 <p/>
3456 For <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>,
3457 the referrer object is a class (referred to below as <i>C</i>)
3458 or an interface (referred to below as <i>I</i>).
3459 In this case, <code>index</code> is the index of the field in
3460 that class or interface.
3461 <p/>
3462 If the referrer object is not an interface, then the field
3463 indices are determined as follows:
3464 <ul>
3465 <li>make a list of all the fields in <i>C</i> and its
3466 superclasses, starting with all the fields in
3467 <code>java.lang.Object</code> and ending with all the
3468 fields in <i>C</i>.</li>
3469 <li>Within this list, put
3470 the fields for a given class in the order returned by
3471 <functionlink id="GetClassFields"/>.</li>
3472 <li>Assign the fields in this list indices
3473 <i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i>
3474 is the count of the fields in all the interfaces
3475 implemented by <i>C</i>.
3476 Note that <i>C</i> implements all interfaces
3477 directly implemented by its superclasses; as well
3478 as all superinterfaces of these interfaces.</li>
3479 </ul>
3480 If the referrer object is an interface, then the field
3481 indices are determined as follows:
3482 <ul>
3483 <li>make a list of the fields directly declared in
3484 <i>I</i>.</li>
3485 <li>Within this list, put
3486 the fields in the order returned by
3487 <functionlink id="GetClassFields"/>.</li>
3488 <li>Assign the fields in this list indices
3489 <i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i>
3490 is the count of the fields in all the superinterfaces
3491 of <i>I</i>.</li>
3492 </ul>
3493 All fields are included in this computation, regardless of
3494 field modifier (static, public, private, etc).
3495 <p/>
3496 For example, given the following classes and interfaces:
3497 <example>
3498 interface I0 {
3499 int p = 0;
3500 }
3501
3502 interface I1 extends I0 {
3503 int x = 1;
3504 }
3505
3506 interface I2 extends I0 {
3507 int y = 2;
3508 }
3509
3510 class C1 implements I1 {
3511 public static int a = 3;
3512 private int b = 4;
3513 }
3514
3515 class C2 extends C1 implements I2 {
3516 static int q = 5;
3517 final int r = 6;
3518 }
3519 </example>
3520 Assume that <functionlink id="GetClassFields"/> called on
3521 <code>C1</code> returns the fields of <code>C1</code> in the
3522 order: a, b; and that the fields of <code>C2</code> are
3523 returned in the order: q, r.
3524 An instance of class <code>C1</code> will have the
3525 following field indices:
3526 <blockquote><table>
3527 <tr class="bgLight">
3528 <th class="centered" scope="col">Field</th>
3529 <th class="centered" scope="col">Index</th>
3530 <th scope="col">Description</th>
3531 </tr>
3532 <tr>
3533 <th class="centered" scope="row">
3534 a
3535 </th>
3536 <td class="centered">
3537 2
3538 </td>
3539 <td>
3540 The count of the fields in the interfaces
3541 implemented by <code>C1</code> is two (<i>n</i>=2):
3542 <code>p</code> of <code>I0</code>
3543 and <code>x</code> of <code>I1</code>.
3544 </td>
3545 </tr>
3546 <tr>
3547 <th class="centered" scope="row">
3548 b
3549 </th>
3550 <td class="centered">
3551 3
3552 </td>
3553 <td>
3554 the subsequent index.
3555 </td>
3556 </tr>
3557 </table></blockquote>
3558 The class <code>C1</code> will have the same field indices.
3559 <p/>
3560 An instance of class <code>C2</code> will have the
3561 following field indices:
3562 <blockquote><table>
3563 <tr class="bgLight">
3564 <th class="centered" scope="col">Field</th>
3565 <th class="centered" scope="col">Index</th>
3566 <th scope="col">Description</th>
3567 </tr>
3568 <tr>
3569 <th class="centered" scope="row">
3570 a
3571 </th>
3572 <td class="centered">
3573 3
3574 </td>
3575 <td>
3576 The count of the fields in the interfaces
3577 implemented by <code>C2</code> is three (<i>n</i>=3):
3578 <code>p</code> of <code>I0</code>,
3579 <code>x</code> of <code>I1</code> and <code>y</code> of <code>I2</code>
3580 (an interface of <code>C2</code>). Note that the field <code>p</code>
3581 of <code>I0</code> is only included once.
3582 </td>
3583 </tr>
3584 <tr>
3585 <th class="centered" scope="row">
3586 b
3587 </th>
3588 <td class="centered">
3589 4
3590 </td>
3591 <td>
3592 the subsequent index to "a".
3593 </td>
3594 </tr>
3595 <tr>
3596 <th class="centered" scope="row">
3597 q
3598 </th>
3599 <td class="centered">
3600 5
3601 </td>
3602 <td>
3603 the subsequent index to "b".
3604 </td>
3605 </tr>
3606 <tr>
3607 <th class="centered" scope="row">
3608 r
3609 </th>
3610 <td class="centered">
3611 6
3612 </td>
3613 <td>
3614 the subsequent index to "q".
3615 </td>
3616 </tr>
3617 </table></blockquote>
3618 The class <code>C2</code> will have the same field indices.
3619 Note that a field may have a different index depending on the
3620 object that is viewing it -- for example field "a" above.
3621 Note also: not all field indices may be visible from the
3622 callbacks, but all indices are shown for illustrative purposes.
3623 <p/>
3624 The interface <code>I1</code> will have the
3625 following field indices:
3626 <blockquote><table>
3627 <tr class="bgLight">
3628 <th class="centered" scope="col">Field</th>
3629 <th class="centered" scope="col">Index</th>
3630 <th scope="col">Description</th>
3631 </tr>
3632 <tr>
3633 <th class="centered" scope="row">
3634 x
3635 </th>
3636 <td class="centered">
3637 1
3638 </td>
3639 <td>
3640 The count of the fields in the superinterfaces
3641 of <code>I1</code> is one (<i>n</i>=1):
3642 <code>p</code> of <code>I0</code>.
3643 </td>
3644 </tr>
3645 </table></blockquote>
3646 </description>
3647 </field>
3648 </typedef>
3649
3650 <typedef id="jvmtiHeapReferenceInfoArray"
3651 label="Reference information structure for Array references"
3652 since="1.1">
3653 <description>
3654 Reference information returned for
3655 <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references.
3656 </description>
3657 <field id="index">
3658 <jint/>
3659 <description>
3660 The array index.
3661 </description>
3662 </field>
3663 </typedef>
3664
3665 <typedef id="jvmtiHeapReferenceInfoConstantPool"
3666 label="Reference information structure for Constant Pool references"
3667 since="1.1">
3668 <description>
3669 Reference information returned for
3670 <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references.
3671 </description>
3672 <field id="index">
3673 <jint/>
3674 <description>
3675 The index into the constant pool of the class. See the description in
3676 <vmspec chapter="4.4"/>.
3677 </description>
3678 </field>
3679 </typedef>
3680
3681 <typedef id="jvmtiHeapReferenceInfoStackLocal"
3682 label="Reference information structure for Local Variable references"
3683 since="1.1">
3684 <description>
3685 Reference information returned for
3686 <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references.
3687 </description>
3688 <field id="thread_tag">
3689 <jlong/>
3690 <description>
3691 The tag of the thread corresponding to this stack, zero if not tagged.
3692 </description>
3693 </field>
3694 <field id="thread_id">
3695 <jlong/>
3696 <description>
3697 The unique thread ID of the thread corresponding to this stack.
3698 </description>
3699 </field>
3700 <field id="depth">
3701 <jint/>
3702 <description>
3703 The depth of the frame.
3704 </description>
3705 </field>
3706 <field id="method">
3707 <jmethodID/>
3708 <description>
3709 The method executing in this frame.
3710 </description>
3711 </field>
3712 <field id="location">
3713 <jlocation/>
3714 <description>
3715 The currently executing location in this frame.
3716 </description>
3717 </field>
3718 <field id="slot">
3719 <jint/>
3720 <description>
3721 The slot number of the local variable.
3722 </description>
3723 </field>
3724 </typedef>
3725
3726 <typedef id="jvmtiHeapReferenceInfoJniLocal"
3727 label="Reference information structure for JNI local references"
3728 since="1.1">
3729 <description>
3730 Reference information returned for
3731 <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references.
3732 </description>
3733 <field id="thread_tag">
3734 <jlong/>
3735 <description>
3736 The tag of the thread corresponding to this stack, zero if not tagged.
3737 </description>
3738 </field>
3739 <field id="thread_id">
3740 <jlong/>
3741 <description>
3742 The unique thread ID of the thread corresponding to this stack.
3743 </description>
3744 </field>
3745 <field id="depth">
3746 <jint/>
3747 <description>
3748 The depth of the frame.
3749 </description>
3750 </field>
3751 <field id="method">
3752 <jmethodID/>
3753 <description>
3754 The method executing in this frame.
3755 </description>
3756 </field>
3757 </typedef>
3758
3759 <typedef id="jvmtiHeapReferenceInfoReserved"
3760 label="Reference information structure for Other references"
3761 since="1.1">
3762 <description>
3763 Reference information returned for other references.
3764 </description>
3765 <field id="reserved1">
3766 <jlong/>
3767 <description>
3768 reserved for future use.
3769 </description>
3770 </field>
3771 <field id="reserved2">
3772 <jlong/>
3773 <description>
3774 reserved for future use.
3775 </description>
3776 </field>
3777 <field id="reserved3">
3778 <jlong/>
3779 <description>
3780 reserved for future use.
3781 </description>
3782 </field>
3783 <field id="reserved4">
3784 <jlong/>
3785 <description>
3786 reserved for future use.
3787 </description>
3788 </field>
3789 <field id="reserved5">
3790 <jlong/>
3791 <description>
3792 reserved for future use.
3793 </description>
3794 </field>
3795 <field id="reserved6">
3796 <jlong/>
3797 <description>
3798 reserved for future use.
3799 </description>
3800 </field>
3801 <field id="reserved7">
3802 <jlong/>
3803 <description>
3804 reserved for future use.
3805 </description>
3806 </field>
3807 <field id="reserved8">
3808 <jlong/>
3809 <description>
3810 reserved for future use.
3811 </description>
3812 </field>
3813 </typedef>
3814
3815 <uniontypedef id="jvmtiHeapReferenceInfo"
3816 label="Reference information structure"
3817 since="1.1">
3818 <description>
3819 The information returned about referrers.
3820 Represented as a union of the various kinds of reference information.
3821 </description>
3822 <field id="field">
3823 <struct>jvmtiHeapReferenceInfoField</struct>
3824 <description>
3825 The referrer information for
3826 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>
3827 and <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references.
3828 </description>
3829 </field>
3830 <field id="array">
3831 <struct>jvmtiHeapReferenceInfoArray</struct>
3832 <description>
3833 The referrer information for
3834 For <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references.
3835 </description>
3836 </field>
3837 <field id="constant_pool">
3838 <struct>jvmtiHeapReferenceInfoConstantPool</struct>
3839 <description>
3840 The referrer information for
3841 For <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references.
3842 </description>
3843 </field>
3844 <field id="stack_local">
3845 <struct>jvmtiHeapReferenceInfoStackLocal</struct>
3846 <description>
3847 The referrer information for
3848 For <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references.
3849 </description>
3850 </field>
3851 <field id="jni_local">
3852 <struct>jvmtiHeapReferenceInfoJniLocal</struct>
3853 <description>
3854 The referrer information for
3855 For <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references.
3856 </description>
3857 </field>
3858 <field id="other">
3859 <struct>jvmtiHeapReferenceInfoReserved</struct>
3860 <description>
3861 reserved for future use.
3862 </description>
3863 </field>
3864 </uniontypedef>
3865
3866 <typedef id="jvmtiHeapCallbacks"
3867 label="Heap callback function structure"
3868 since="1.1">
3869 <field id="heap_iteration_callback">
3870 <ptrtype>
3871 <struct>jvmtiHeapIterationCallback</struct>
3872 </ptrtype>
3873 <description>
3874 The callback to be called to describe an
3875 object in the heap. Used by the
3876 <functionlink id="IterateThroughHeap"/> function, ignored by the
3877 <functionlink id="FollowReferences"/> function.
3878 </description>
3879 </field>
3880 <field id="heap_reference_callback">
3881 <ptrtype>
3882 <struct>jvmtiHeapReferenceCallback</struct>
3883 </ptrtype>
3884 <description>
3885 The callback to be called to describe an
3886 object reference. Used by the
3887 <functionlink id="FollowReferences"/> function, ignored by the
3888 <functionlink id="IterateThroughHeap"/> function.
3889 </description>
3890 </field>
3891 <field id="primitive_field_callback">
3892 <ptrtype>
3893 <struct>jvmtiPrimitiveFieldCallback</struct>
3894 </ptrtype>
3895 <description>
3896 The callback to be called to describe a
3897 primitive field.
3898 </description>
3899 </field>
3900 <field id="array_primitive_value_callback">
3901 <ptrtype>
3902 <struct>jvmtiArrayPrimitiveValueCallback</struct>
3903 </ptrtype>
3904 <description>
3905 The callback to be called to describe an
3906 array of primitive values.
3907 </description>
3908 </field>
3909 <field id="string_primitive_value_callback">
3910 <ptrtype>
3911 <struct>jvmtiStringPrimitiveValueCallback</struct>
3912 </ptrtype>
3913 <description>
3914 The callback to be called to describe a String value.
3915 </description>
3916 </field>
3917 <field id="reserved5">
3918 <ptrtype>
3919 <struct>jvmtiReservedCallback</struct>
3920 </ptrtype>
3921 <description>
3922 Reserved for future use..
3923 </description>
3924 </field>
3925 <field id="reserved6">
3926 <ptrtype>
3927 <struct>jvmtiReservedCallback</struct>
3928 </ptrtype>
3929 <description>
3930 Reserved for future use..
3931 </description>
3932 </field>
3933 <field id="reserved7">
3934 <ptrtype>
3935 <struct>jvmtiReservedCallback</struct>
3936 </ptrtype>
3937 <description>
3938 Reserved for future use..
3939 </description>
3940 </field>
3941 <field id="reserved8">
3942 <ptrtype>
3943 <struct>jvmtiReservedCallback</struct>
3944 </ptrtype>
3945 <description>
3946 Reserved for future use..
3947 </description>
3948 </field>
3949 <field id="reserved9">
3950 <ptrtype>
3951 <struct>jvmtiReservedCallback</struct>
3952 </ptrtype>
3953 <description>
3954 Reserved for future use..
3955 </description>
3956 </field>
3957 <field id="reserved10">
3958 <ptrtype>
3959 <struct>jvmtiReservedCallback</struct>
3960 </ptrtype>
3961 <description>
3962 Reserved for future use..
3963 </description>
3964 </field>
3965 <field id="reserved11">
3966 <ptrtype>
3967 <struct>jvmtiReservedCallback</struct>
3968 </ptrtype>
3969 <description>
3970 Reserved for future use..
3971 </description>
3972 </field>
3973 <field id="reserved12">
3974 <ptrtype>
3975 <struct>jvmtiReservedCallback</struct>
3976 </ptrtype>
3977 <description>
3978 Reserved for future use..
3979 </description>
3980 </field>
3981 <field id="reserved13">
3982 <ptrtype>
3983 <struct>jvmtiReservedCallback</struct>
3984 </ptrtype>
3985 <description>
3986 Reserved for future use..
3987 </description>
3988 </field>
3989 <field id="reserved14">
3990 <ptrtype>
3991 <struct>jvmtiReservedCallback</struct>
3992 </ptrtype>
3993 <description>
3994 Reserved for future use..
3995 </description>
3996 </field>
3997 <field id="reserved15">
3998 <ptrtype>
3999 <struct>jvmtiReservedCallback</struct>
4000 </ptrtype>
4001 <description>
4002 Reserved for future use..
4003 </description>
4004 </field>
4005 </typedef>
4006
4007
4008 <intro>
4009 <rationale>
4010 The heap dumping functionality (below) uses a callback
4011 for each object. While it would seem that a buffered approach
4012 would provide better throughput, tests do
4013 not show this to be the case--possibly due to locality of
4014 memory reference or array access overhead.
4015 </rationale>
4016
4017 <issue>
4018 Still under investigation as to if java.lang.ref references
4019 are reported as a different type of reference.
4020 </issue>
4021
4022 <issue>
4023 Should or can an indication of the cost or relative cost of
4024 these operations be included?
4025 </issue>
4026
4027 </intro>
4028
4029 <callback id="jvmtiHeapIterationCallback" since="1.1">
4030 <jint/>
4031 <synopsis>Heap Iteration Callback</synopsis>
4032 <description>
4033 Agent supplied callback function.
4034 Describes (but does not pass in) an object in the heap.
4035 <p/>
4036 This function should return a bit vector of the desired
4037 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4038 This will determine if the entire iteration should be aborted
4039 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4040 <p/>
4041 See the <internallink id="heapCallbacks">heap callback
4042 function restrictions</internallink>.
4043 </description>
4044 <parameters>
4045 <param id="class_tag">
4046 <jlong/>
4047 <description>
4048 The tag of the class of object (zero if the class is not tagged).
4049 If the object represents a runtime class,
4050 the <code>class_tag</code> is the tag
4051 associated with <code>java.lang.Class</code>
4052 (zero if <code>java.lang.Class</code> is not tagged).
4053 </description>
4054 </param>
4055 <param id="size">
4056 <jlong/>
4057 <description>
4058 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
4059 </description>
4060 </param>
4061 <param id="tag_ptr">
4062 <outptr><jlong/></outptr>
4063 <description>
4064 The object tag value, or zero if the object is not tagged.
4065 To set the tag value to be associated with the object
4066 the agent sets the <code>jlong</code> pointed to by the parameter.
4067 </description>
4068 </param>
4069 <param id="length">
4070 <jint/>
4071 <description>
4072 If this object is an array, the length of the array. Otherwise negative one (-1).
4073 </description>
4074 </param>
4075 <param id="user_data">
4076 <outptr><void/></outptr>
4077 <description>
4078 The user supplied data that was passed into the iteration function.
4079 </description>
4080 </param>
4081 </parameters>
4082 </callback>
4083
4084 <callback id="jvmtiHeapReferenceCallback" since="1.1">
4085 <jint/>
4086 <synopsis>Heap Reference Callback</synopsis>
4087 <description>
4088 Agent supplied callback function.
4089 Describes a reference from an object or the VM (the referrer) to another object
4090 (the referree) or a heap root to a referree.
4091 <p/>
4092 This function should return a bit vector of the desired
4093 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4094 This will determine if the objects referenced by the referree
4095 should be visited or if the entire iteration should be aborted.
4096 <p/>
4097 See the <internallink id="heapCallbacks">heap callback
4098 function restrictions</internallink>.
4099 </description>
4100 <parameters>
4101 <param id="reference_kind">
4102 <enum>jvmtiHeapReferenceKind</enum>
4103 <description>
4104 The kind of reference.
4105 </description>
4106 </param>
4107 <param id="reference_info">
4108 <inptr>
4109 <struct>jvmtiHeapReferenceInfo</struct>
4110 </inptr>
4111 <description>
4112 Details about the reference.
4113 Set when the <datalink id="jvmtiHeapReferenceCallback.reference_kind">reference_kind</datalink> is
4114 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>,
4115 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>,
4116 <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/>,
4117 <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/>,
4118 <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/>,
4119 or <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/>.
4120 Otherwise <code>NULL</code>.
4121 </description>
4122 </param>
4123 <param id="class_tag">
4124 <jlong/>
4125 <description>
4126 The tag of the class of referree object (zero if the class is not tagged).
4127 If the referree object represents a runtime class,
4128 the <code>class_tag</code> is the tag
4129 associated with <code>java.lang.Class</code>
4130 (zero if <code>java.lang.Class</code> is not tagged).
4131 </description>
4132 </param>
4133 <param id="referrer_class_tag">
4134 <jlong/>
4135 <description>
4136 The tag of the class of the referrer object (zero if the class is not tagged
4137 or the referree is a heap root). If the referrer object represents a runtime
4138 class, the <code>referrer_class_tag</code> is the tag associated with
4139 the <code>java.lang.Class</code>
4140 (zero if <code>java.lang.Class</code> is not tagged).
4141 </description>
4142 </param>
4143 <param id="size">
4144 <jlong/>
4145 <description>
4146 Size of the referree object (in bytes).
4147 See <functionlink id="GetObjectSize"/>.
4148 </description>
4149 </param>
4150 <param id="tag_ptr">
4151 <outptr><jlong/></outptr>
4152 <description>
4153 Points to the referree object tag value, or zero if the object is not
4154 tagged.
4155 To set the tag value to be associated with the object
4156 the agent sets the <code>jlong</code> pointed to by the parameter.
4157 </description>
4158 </param>
4159 <param id="referrer_tag_ptr">
4160 <outptr><jlong/></outptr>
4161 <description>
4162 Points to the tag of the referrer object, or
4163 points to the zero if the referrer
4164 object is not tagged.
4165 <code>NULL</code> if the referrer in not an object (that is,
4166 this callback is reporting a heap root).
4167 To set the tag value to be associated with the referrer object
4168 the agent sets the <code>jlong</code> pointed to by the parameter.
4169 If this callback is reporting a reference from an object to itself,
4170 <code>referrer_tag_ptr == tag_ptr</code>.
4171 </description>
4172 </param>
4173 <param id="length">
4174 <jint/>
4175 <description>
4176 If this object is an array, the length of the array. Otherwise negative one (-1).
4177 </description>
4178 </param>
4179 <param id="user_data">
4180 <outptr><void/></outptr>
4181 <description>
4182 The user supplied data that was passed into the iteration function.
4183 </description>
4184 </param>
4185 </parameters>
4186 </callback>
4187
4188 <callback id="jvmtiPrimitiveFieldCallback" since="1.1">
4189 <jint/>
4190 <synopsis>Primitive Field Callback</synopsis>
4191 <description>
4192 Agent supplied callback function which
4193 describes a primitive field of an object (<i>the object</i>).
4194 A primitive field is a field whose type is a primitive type.
4195 This callback will describe a static field if the object is a class,
4196 and otherwise will describe an instance field.
4197 <p/>
4198 This function should return a bit vector of the desired
4199 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4200 This will determine if the entire iteration should be aborted
4201 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4202 <p/>
4203 See the <internallink id="heapCallbacks">heap callback
4204 function restrictions</internallink>.
4205 </description>
4206 <parameters>
4207 <param id="kind">
4208 <enum>jvmtiHeapReferenceKind</enum>
4209 <description>
4210 The kind of field -- instance or static (<datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> or
4211 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>).
4212 </description>
4213 </param>
4214 <param id="info">
4215 <inptr>
4216 <struct>jvmtiHeapReferenceInfo</struct>
4217 </inptr>
4218 <description>
4219 Which field (the field index).
4220 </description>
4221 </param>
4222 <param id="object_class_tag">
4223 <jlong/>
4224 <description>
4225 The tag of the class of the object (zero if the class is not tagged).
4226 If the object represents a runtime class, the
4227 <code>object_class_tag</code> is the tag
4228 associated with <code>java.lang.Class</code>
4229 (zero if <code>java.lang.Class</code> is not tagged).
4230 </description>
4231 </param>
4232 <param id="object_tag_ptr">
4233 <outptr><jlong/></outptr>
4234 <description>
4235 Points to the tag of the object, or zero if the object is not
4236 tagged.
4237 To set the tag value to be associated with the object
4238 the agent sets the <code>jlong</code> pointed to by the parameter.
4239 </description>
4240 </param>
4241 <param id="value">
4242 <jvalue/>
4243 <description>
4244 The value of the field.
4245 </description>
4246 </param>
4247 <param id="value_type">
4248 <enum>jvmtiPrimitiveType</enum>
4249 <description>
4250 The type of the field.
4251 </description>
4252 </param>
4253 <param id="user_data">
4254 <outptr><void/></outptr>
4255 <description>
4256 The user supplied data that was passed into the iteration function.
4257 </description>
4258 </param>
4259 </parameters>
4260 </callback>
4261
4262 <callback id="jvmtiArrayPrimitiveValueCallback" since="1.1">
4263 <jint/>
4264 <synopsis>Array Primitive Value Callback</synopsis>
4265 <description>
4266 Agent supplied callback function.
4267 Describes the values in an array of a primitive type.
4268 <p/>
4269 This function should return a bit vector of the desired
4270 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4271 This will determine if the entire iteration should be aborted
4272 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4273 <p/>
4274 See the <internallink id="heapCallbacks">heap callback
4275 function restrictions</internallink>.
4276 </description>
4277 <parameters>
4278 <param id="class_tag">
4279 <jlong/>
4280 <description>
4281 The tag of the class of the array object (zero if the class is not tagged).
4282 </description>
4283 </param>
4284 <param id="size">
4285 <jlong/>
4286 <description>
4287 Size of the array (in bytes).
4288 See <functionlink id="GetObjectSize"/>.
4289 </description>
4290 </param>
4291 <param id="tag_ptr">
4292 <outptr><jlong/></outptr>
4293 <description>
4294 Points to the tag of the array object, or zero if the object is not
4295 tagged.
4296 To set the tag value to be associated with the object
4297 the agent sets the <code>jlong</code> pointed to by the parameter.
4298 </description>
4299 </param>
4300 <param id="element_count">
4301 <jint/>
4302 <description>
4303 The length of the primitive array.
4304 </description>
4305 </param>
4306 <param id="element_type">
4307 <enum>jvmtiPrimitiveType</enum>
4308 <description>
4309 The type of the elements of the array.
4310 </description>
4311 </param>
4312 <param id="elements">
4313 <vmbuf><void/></vmbuf>
4314 <description>
4315 The elements of the array in a packed array of <code>element_count</code>
4316 items of <code>element_type</code> size each.
4317 </description>
4318 </param>
4319 <param id="user_data">
4320 <outptr><void/></outptr>
4321 <description>
4322 The user supplied data that was passed into the iteration function.
4323 </description>
4324 </param>
4325 </parameters>
4326 </callback>
4327
4328 <callback id="jvmtiStringPrimitiveValueCallback" since="1.1">
4329 <jint/>
4330 <synopsis>String Primitive Value Callback</synopsis>
4331 <description>
4332 Agent supplied callback function.
4333 Describes the value of a java.lang.String.
4334 <p/>
4335 This function should return a bit vector of the desired
4336 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4337 This will determine if the entire iteration should be aborted
4338 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4339 <p/>
4340 See the <internallink id="heapCallbacks">heap callback
4341 function restrictions</internallink>.
4342 </description>
4343 <parameters>
4344 <param id="class_tag">
4345 <jlong/>
4346 <description>
4347 The tag of the class of the String class (zero if the class is not tagged).
4348 <issue>Is this needed?</issue>
4349 </description>
4350 </param>
4351 <param id="size">
4352 <jlong/>
4353 <description>
4354 Size of the string (in bytes).
4355 See <functionlink id="GetObjectSize"/>.
4356 </description>
4357 </param>
4358 <param id="tag_ptr">
4359 <outptr><jlong/></outptr>
4360 <description>
4361 Points to the tag of the String object, or zero if the object is not
4362 tagged.
4363 To set the tag value to be associated with the object
4364 the agent sets the <code>jlong</code> pointed to by the parameter.
4365 </description>
4366 </param>
4367 <param id="value">
4368 <vmbuf><jchar/></vmbuf>
4369 <description>
4370 The value of the String, encoded as a Unicode string.
4371 </description>
4372 </param>
4373 <param id="value_length">
4374 <jint/>
4375 <description>
4376 The length of the string.
4377 The length is equal to the number of 16-bit Unicode
4378 characters in the string.
4379 </description>
4380 </param>
4381 <param id="user_data">
4382 <outptr><void/></outptr>
4383 <description>
4384 The user supplied data that was passed into the iteration function.
4385 </description>
4386 </param>
4387 </parameters>
4388 </callback>
4389
4390
4391 <callback id="jvmtiReservedCallback" since="1.1">
4392 <jint/>
4393 <synopsis>reserved for future use Callback</synopsis>
4394 <description>
4395 Placeholder -- reserved for future use.
4396 </description>
4397 <parameters>
4398 </parameters>
4399 </callback>
4400
4401 <function id="FollowReferences" num="115" since="1.1">
4402 <synopsis>Follow References</synopsis>
4403 <description>
4404 This function initiates a traversal over the objects that are
4405 directly and indirectly reachable from the specified object or,
4406 if <code>initial_object</code> is not specified, all objects
4407 reachable from the heap roots.
4408 The heap root are the set of system classes,
4409 JNI globals, references from thread stacks, and other objects used as roots
4410 for the purposes of garbage collection.
4411 <p/>
4412 This function operates by traversing the reference graph.
4413 Let <i>A</i>, <i>B</i>, ... represent objects.
4414 When a reference from <i>A</i> to <i>B</i> is traversed,
4415 when a reference from a heap root to <i>B</i> is traversed,
4416 or when <i>B</i> is specified as the <paramlink id="initial_object"/>,
4417 then <i>B</i> is said to be <i>visited</i>.
4418 A reference from <i>A</i> to <i>B</i> is not traversed until <i>A</i>
4419 is visited.
4420 References are reported in the same order that the references are traversed.
4421 Object references are reported by invoking the agent supplied
4422 callback function <functionlink id="jvmtiHeapReferenceCallback"/>.
4423 In a reference from <i>A</i> to <i>B</i>, <i>A</i> is known
4424 as the <i>referrer</i> and <i>B</i> as the <i>referree</i>.
4425 The callback is invoked exactly once for each reference from a referrer;
4426 this is true even if there are reference cycles or multiple paths to
4427 the referrer.
4428 There may be more than one reference between a referrer and a referree,
4429 each reference is reported.
4430 These references may be distinguished by examining the
4431 <datalink
4432 id="jvmtiHeapReferenceCallback.reference_kind"><code>reference_kind</code></datalink>
4433 and
4434 <datalink
4435 id="jvmtiHeapReferenceCallback.reference_info"><code>reference_info</code></datalink>
4436 parameters of the <functionlink id="jvmtiHeapReferenceCallback"/> callback.
4437 <p/>
4438 This function reports a Java programming language view of object references,
4439 not a virtual machine implementation view. The following object references
4440 are reported when they are non-null:
4441 <ul>
4442 <li>Instance objects report references to each non-primitive instance fields
4443 (including inherited fields).</li>
4444 <li>Instance objects report a reference to the object type (class).</li>
4445 <li>Classes report a reference to the superclass and directly
4446 implemented/extended interfaces.</li>
4447 <li>Classes report a reference to the class loader, protection domain,
4448 signers, and resolved entries in the constant pool.</li>
4449 <li>Classes report a reference to each directly declared non-primitive
4450 static field.</li>
4451 <li>Arrays report a reference to the array type (class) and each
4452 array element.</li>
4453 <li>Primitive arrays report a reference to the array type.</li>
4454 </ul>
4455 <p/>
4456 This function can also be used to examine primitive (non-object) values.
4457 The primitive value of an array or String
4458 is reported after the object has been visited;
4459 it is reported by invoking the agent supplied callback function
4460 <functionlink id="jvmtiArrayPrimitiveValueCallback"/> or
4461 <functionlink id="jvmtiStringPrimitiveValueCallback"/>.
4462 A primitive field
4463 is reported after the object with that field is visited;
4464 it is reported by invoking the agent supplied callback function
4465 <functionlink id="jvmtiPrimitiveFieldCallback"/>.
4466 <p/>
4467 Whether a callback is provided or is <code>NULL</code> only determines
4468 whether the callback will be invoked, it does not influence
4469 which objects are visited nor does it influence whether other callbacks
4470 will be invoked.
4471 However, the
4472 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>
4473 returned by <functionlink id="jvmtiHeapReferenceCallback"/>
4474 do determine if the objects referenced by the
4475 current object as visited.
4476 The <datalink id="jvmtiHeapFilter">heap filter flags</datalink>
4477 and <paramlink id="klass"/> provided as parameters to this function
4478 do not control which objects are visited but they do control which
4479 objects and primitive values are reported by the callbacks.
4480 For example, if the only callback that was set is
4481 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> and <code>klass</code>
4482 is set to the array of bytes class, then only arrays of byte will be
4483 reported.
4484 The table below summarizes this:
4485 <p/>
4486 <table>
4487 <tr class="bgLight">
4488 <th/>
4489 <th class="centered" scope="col">Controls objects visited</th>
4490 <th class="centered" scope="col">Controls objects reported</th>
4491 <th class="centered" scope="col">Controls primitives reported</th>
4492 </tr>
4493 <tr>
4494 <th scope="row">
4495 the
4496 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4497 returned by <functionlink id="jvmtiHeapReferenceCallback"/>
4498 </th>
4499 <td class="centered">
4500 <b>Yes</b>
4501 </td>
4502 <td class="centered">
4503 <b>Yes</b>, since visits are controlled
4504 </td>
4505 <td class="centered">
4506 <b>Yes</b>, since visits are controlled
4507 </td>
4508 </tr>
4509 <tr>
4510 <th scope="row">
4511 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/>
4512 in <paramlink id="callbacks"/> set
4513 </th>
4514 <td class="centered">
4515 No
4516 </td>
4517 <td class="centered">
4518 <b>Yes</b>
4519 </td>
4520 <td class="centered">
4521 No
4522 </td>
4523 </tr>
4524 <tr>
4525 <th scope="row">
4526 <paramlink id="heap_filter"/>
4527 </th>
4528 <td class="centered">
4529 No
4530 </td>
4531 <td class="centered">
4532 <b>Yes</b>
4533 </td>
4534 <td class="centered">
4535 <b>Yes</b>
4536 </td>
4537 </tr>
4538 <tr>
4539 <th scope="row">
4540 <paramlink id="klass"/>
4541 </th>
4542 <td class="centered">
4543 No
4544 </td>
4545 <td class="centered">
4546 <b>Yes</b>
4547 </td>
4548 <td class="centered">
4549 <b>Yes</b>
4550 </td>
4551 </tr>
4552 </table>
4553 <p/>
4554 During the execution of this function the state of the heap
4555 does not change: no objects are allocated, no objects are
4556 garbage collected, and the state of objects (including
4557 held values) does not change.
4558 As a result, threads executing Java
4559 programming language code, threads attempting to resume the
4560 execution of Java programming language code, and threads
4561 attempting to execute JNI functions are typically stalled.
4562 </description>
4563 <origin>new</origin>
4564 <capabilities>
4565 <required id="can_tag_objects"></required>
4566 </capabilities>
4567 <parameters>
4568 <param id="heap_filter">
4569 <jint/>
4570 <description>
4571 This bit vector of
4572 <datalink id="jvmtiHeapFilter">heap filter flags</datalink>.
4573 restricts the objects for which the callback function is called.
4574 This applies to both the object and primitive callbacks.
4575 </description>
4576 </param>
4577 <param id="klass">
4578 <ptrtype>
4579 <jclass/>
4580 <nullok>callbacks are not limited to instances of a particular
4581 class</nullok>
4582 </ptrtype>
4583 <description>
4584 Callbacks are only reported when the object is an instance of
4585 this class.
4586 Objects which are instances of a subclass of <code>klass</code>
4587 are not reported.
4588 If <code>klass</code> is an interface, no objects are reported.
4589 This applies to both the object and primitive callbacks.
4590 </description>
4591 </param>
4592 <param id="initial_object">
4593 <ptrtype>
4594 <jobject/>
4595 <nullok>references are followed from the heap roots</nullok>
4596 </ptrtype>
4597 <description>
4598 The object to follow
4599 </description>
4600 </param>
4601 <param id="callbacks">
4602 <inptr>
4603 <struct>jvmtiHeapCallbacks</struct>
4604 </inptr>
4605 <description>
4606 Structure defining the set of callback functions.
4607 </description>
4608 </param>
4609 <param id="user_data">
4610 <inbuf>
4611 <void/>
4612 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
4613 </inbuf>
4614 <description>
4615 User supplied data to be passed to the callback.
4616 </description>
4617 </param>
4618 </parameters>
4619 <errors>
4620 <error id="JVMTI_ERROR_INVALID_CLASS">
4621 <paramlink id="klass"/> is not a valid class.
4622 </error>
4623 <error id="JVMTI_ERROR_INVALID_OBJECT">
4624 <paramlink id="initial_object"/> is not a valid object.
4625 </error>
4626 </errors>
4627 </function>
4628
4629
4630 <function id="IterateThroughHeap" num="116" since="1.1">
4631 <synopsis>Iterate Through Heap</synopsis>
4632 <description>
4633 Initiate an iteration over all objects in the heap.
4634 This includes both reachable and
4635 unreachable objects. Objects are visited in no particular order.
4636 <p/>
4637 Heap objects are reported by invoking the agent supplied
4638 callback function <functionlink id="jvmtiHeapIterationCallback"/>.
4639 References between objects are not reported.
4640 If only reachable objects are desired, or if object reference information
4641 is needed, use <functionlink id="FollowReferences"/>.
4642 <p/>
4643 This function can also be used to examine primitive (non-object) values.
4644 The primitive value of an array or String
4645 is reported after the object has been visited;
4646 it is reported by invoking the agent supplied callback function
4647 <functionlink id="jvmtiArrayPrimitiveValueCallback"/> or
4648 <functionlink id="jvmtiStringPrimitiveValueCallback"/>.
4649 A primitive field
4650 is reported after the object with that field is visited;
4651 it is reported by invoking the agent supplied
4652 callback function
4653 <functionlink id="jvmtiPrimitiveFieldCallback"/>.
4654 <p/>
4655 Unless the iteration is aborted by the
4656 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4657 returned by a callback, all objects in the heap are visited.
4658 Whether a callback is provided or is <code>NULL</code> only determines
4659 whether the callback will be invoked, it does not influence
4660 which objects are visited nor does it influence whether other callbacks
4661 will be invoked.
4662 The <datalink id="jvmtiHeapFilter">heap filter flags</datalink>
4663 and <paramlink id="klass"/> provided as parameters to this function
4664 do not control which objects are visited but they do control which
4665 objects and primitive values are reported by the callbacks.
4666 For example, if the only callback that was set is
4667 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> and <code>klass</code>
4668 is set to the array of bytes class, then only arrays of byte will be
4669 reported. The table below summarizes this (contrast this with
4670 <functionlink id="FollowReferences"/>):
4671 <p/>
4672 <table>
4673 <tr class="bgLight">
4674 <th/>
4675 <th class="centered" scope="col">Controls objects visited</th>
4676 <th class="centered" scope="col">Controls objects reported</th>
4677 <th class="centered" scope="col">Controls primitives reported</th>
4678 </tr>
4679 <tr>
4680 <th scope="row">
4681 the
4682 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4683 returned by <functionlink id="jvmtiHeapIterationCallback"/>
4684 </th>
4685 <td class="centered">
4686 No<br/>(unless they abort the iteration)
4687 </td>
4688 <td class="centered">
4689 No<br/>(unless they abort the iteration)
4690 </td>
4691 <td class="centered">
4692 No<br/>(unless they abort the iteration)
4693 </td>
4694 </tr>
4695 <tr>
4696 <th scope="row">
4697 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/>
4698 in <paramlink id="callbacks"/> set
4699 </th>
4700 <td class="centered">
4701 No
4702 </td>
4703 <td class="centered">
4704 <b>Yes</b>
4705 </td>
4706 <td class="centered">
4707 No
4708 </td>
4709 </tr>
4710 <tr>
4711 <th scope="row">
4712 <paramlink id="heap_filter"/>
4713 </th>
4714 <td class="centered">
4715 No
4716 </td>
4717 <td class="centered">
4718 <b>Yes</b>
4719 </td>
4720 <td class="centered">
4721 <b>Yes</b>
4722 </td>
4723 </tr>
4724 <tr>
4725 <th scope="row">
4726 <paramlink id="klass"/>
4727 </th>
4728 <td class="centered">
4729 No
4730 </td>
4731 <td class="centered">
4732 <b>Yes</b>
4733 </td>
4734 <td class="centered">
4735 <b>Yes</b>
4736 </td>
4737 </tr>
4738 </table>
4739 <p/>
4740 During the execution of this function the state of the heap
4741 does not change: no objects are allocated, no objects are
4742 garbage collected, and the state of objects (including
4743 held values) does not change.
4744 As a result, threads executing Java
4745 programming language code, threads attempting to resume the
4746 execution of Java programming language code, and threads
4747 attempting to execute JNI functions are typically stalled.
4748 </description>
4749 <origin>new</origin>
4750 <capabilities>
4751 <required id="can_tag_objects"></required>
4752 </capabilities>
4753 <parameters>
4754 <param id="heap_filter">
4755 <jint/>
4756 <description>
4757 This bit vector of
4758 <datalink id="jvmtiHeapFilter">heap filter flags</datalink>.
4759 restricts the objects for which the callback function is called.
4760 This applies to both the object and primitive callbacks.
4761 </description>
4762 </param>
4763 <param id="klass">
4764 <ptrtype>
4765 <jclass/>
4766 <nullok>callbacks are not limited to instances of a particular class</nullok>
4767 </ptrtype>
4768 <description>
4769 Callbacks are only reported when the object is an instance of
4770 this class.
4771 Objects which are instances of a subclass of <code>klass</code>
4772 are not reported.
4773 If <code>klass</code> is an interface, no objects are reported.
4774 This applies to both the object and primitive callbacks.
4775 </description>
4776 </param>
4777 <param id="callbacks">
4778 <inptr>
4779 <struct>jvmtiHeapCallbacks</struct>
4780 </inptr>
4781 <description>
4782 Structure defining the set callback functions.
4783 </description>
4784 </param>
4785 <param id="user_data">
4786 <inbuf>
4787 <void/>
4788 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
4789 </inbuf>
4790 <description>
4791 User supplied data to be passed to the callback.
4792 </description>
4793 </param>
4794 </parameters>
4795 <errors>
4796 <error id="JVMTI_ERROR_INVALID_CLASS">
4797 <paramlink id="klass"/> is not a valid class.
4798 </error>
4799 </errors>
4800 </function>
4801
4802 <function id="GetTag" phase="start" num="106">
4803 <synopsis>Get Tag</synopsis>
4804 <description>
4805 Retrieve the tag associated with an object.
4806 The tag is a long value typically used to store a
4807 unique identifier or pointer to object information.
4808 The tag is set with
4809 <functionlink id="SetTag"></functionlink>.
4810 Objects for which no tags have been set return a
4811 tag value of zero.
4812 </description>
4813 <origin>new</origin>
4814 <capabilities>
4815 <required id="can_tag_objects"></required>
4816 </capabilities>
4817 <parameters>
4818 <param id="object">
4819 <jobject/>
4820 <description>
4821 The object whose tag is to be retrieved.
4822 </description>
4823 </param>
4824 <param id="tag_ptr">
4825 <outptr><jlong/></outptr>
4826 <description>
4827 On return, the referenced long is set to the value
4828 of the tag.
4829 </description>
4830 </param>
4831 </parameters>
4832 <errors>
4833 </errors>
4834 </function>
4835
4836 <function id="SetTag" phase="start" num="107">
4837 <synopsis>Set Tag</synopsis>
4838 <description>
4839 Set the tag associated with an object.
4840 The tag is a long value typically used to store a
4841 unique identifier or pointer to object information.
4842 The tag is visible with
4843 <functionlink id="GetTag"></functionlink>.
4844 </description>
4845 <origin>new</origin>
4846 <capabilities>
4847 <required id="can_tag_objects"></required>
4848 </capabilities>
4849 <parameters>
4850 <param id="object">
4851 <jobject/>
4852 <description>
4853 The object whose tag is to be set.
4854 </description>
4855 </param>
4856 <param id="tag">
4857 <jlong/>
4858 <description>
4859 The new value of the tag.
4860 </description>
4861 </param>
4862 </parameters>
4863 <errors>
4864 </errors>
4865 </function>
4866
4867 <function id="GetObjectsWithTags" num="114">
4868 <synopsis>Get Objects With Tags</synopsis>
4869 <description>
4870 Return objects in the heap with the specified tags.
4871 The format is parallel arrays of objects and tags.
4872 </description>
4873 <origin>new</origin>
4874 <capabilities>
4875 <required id="can_tag_objects"></required>
4876 </capabilities>
4877 <parameters>
4878 <param id="tag_count">
4879 <jint min="0"/>
4880 <description>
4881 Number of tags to scan for.
4882 </description>
4883 </param>
4884 <param id="tags">
4885 <inbuf incount="tag_count">
4886 <jlong/>
4887 </inbuf>
4888 <description>
4889 Scan for objects with these tags.
4890 Zero is not permitted in this array.
4891 </description>
4892 </param>
4893 <param id="count_ptr">
4894 <outptr>
4895 <jint/>
4896 </outptr>
4897 <description>
4898 Return the number of objects with any of the tags
4899 in <paramlink id="tags"/>.
4900 </description>
4901 </param>
4902 <param id="object_result_ptr">
4903 <allocbuf outcount="count_ptr">
4904 <jobject/>
4905 <nullok>this information is not returned</nullok>
4906 </allocbuf>
4907 <description>
4908 Returns the array of objects with any of the tags
4909 in <paramlink id="tags"/>.
4910 </description>
4911 </param>
4912 <param id="tag_result_ptr">
4913 <allocbuf outcount="count_ptr">
4914 <jlong/>
4915 <nullok>this information is not returned</nullok>
4916 </allocbuf>
4917 <description>
4918 For each object in <paramlink id="object_result_ptr"/>,
4919 return the tag at the corresponding index.
4920 </description>
4921 </param>
4922 </parameters>
4923 <errors>
4924 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
4925 Zero is present in <paramlink id="tags"></paramlink>.
4926 </error>
4927 </errors>
4928 </function>
4929
4930 <function id="ForceGarbageCollection" num="108">
4931 <synopsis>Force Garbage Collection</synopsis>
4932 <description>
4933 Force the VM to perform a garbage collection.
4934 The garbage collection is as complete as possible.
4935 This function does not cause finalizers to be run.
4936 This function does not return until the garbage collection
4937 is finished.
4938 <p/>
4939 Although garbage collection is as complete
4940 as possible there is no guarantee that all
4941 <eventlink id="ObjectFree"/>
4942 events will have been
4943 sent by the time that this function
4944 returns. In particular, an object may be
4945 prevented from being freed because it
4946 is awaiting finalization.
4947 </description>
4948 <origin>new</origin>
4949 <capabilities>
4950 </capabilities>
4951 <parameters>
4952 </parameters>
4953 <errors>
4954 </errors>
4955 </function>
4956
4957
4958 </category>
4959
4960 <category id="Heap_1_0" label="Heap (1.0)">
4961 <intro>
4962 <b>
4963 These functions and data types were introduced in the original
4964 <jvmti/> version 1.0 and have been superseded by more
4965 </b>
4966 <internallink id="Heap"><b>powerful and flexible versions</b></internallink>
4967 <b>
4968 which:
4969 </b>
4970 <ul>
4971 <li>
4972 <b>
4973 Allow access to primitive values (the value of Strings, arrays,
4974 and primitive fields)
4975 </b>
4976 </li>
4977 <li>
4978 <b>
4979 Allow the tag of the referrer to be set, thus enabling more
4980 efficient localized reference graph building
4981 </b>
4982 </li>
4983 <li>
4984 <b>
4985 Provide more extensive filtering abilities
4986 </b>
4987 </li>
4988 <li>
4989 <b>
4990 Are extensible, allowing their abilities to grow in future versions of <jvmti/>
4991 </b>
4992 </li>
4993 </ul>
4994 <p/>
4995 <b>Please use the </b>
4996 <internallink id="Heap"><b>current Heap functions</b></internallink>.
4997 <p/>
4998 <constants id="jvmtiHeapObjectFilter" label="Heap Object Filter Enumeration" kind="enum">
4999 <constant id="JVMTI_HEAP_OBJECT_TAGGED" num="1">
5000 Tagged objects only.
5001 </constant>
5002 <constant id="JVMTI_HEAP_OBJECT_UNTAGGED" num="2">
5003 Untagged objects only.
5004 </constant>
5005 <constant id="JVMTI_HEAP_OBJECT_EITHER" num="3">
5006 Either tagged or untagged objects.
5007 </constant>
5008 </constants>
5009
5010 <constants id="jvmtiHeapRootKind" label="Heap Root Kind Enumeration" kind="enum">
5011 <constant id="JVMTI_HEAP_ROOT_JNI_GLOBAL" num="1">
5012 JNI global reference.
5013 </constant>
5014 <constant id="JVMTI_HEAP_ROOT_SYSTEM_CLASS" num="2">
5015 System class.
5016 </constant>
5017 <constant id="JVMTI_HEAP_ROOT_MONITOR" num="3">
5018 Monitor.
5019 </constant>
5020 <constant id="JVMTI_HEAP_ROOT_STACK_LOCAL" num="4">
5021 Stack local.
5022 </constant>
5023 <constant id="JVMTI_HEAP_ROOT_JNI_LOCAL" num="5">
5024 JNI local reference.
5025 </constant>
5026 <constant id="JVMTI_HEAP_ROOT_THREAD" num="6">
5027 Thread.
5028 </constant>
5029 <constant id="JVMTI_HEAP_ROOT_OTHER" num="7">
5030 Other.
5031 </constant>
5032 </constants>
5033
5034 <constants id="jvmtiObjectReferenceKind" label="Object Reference Enumeration" kind="enum">
5035 <constant id="JVMTI_REFERENCE_CLASS" num="1">
5036 Reference from an object to its class.
5037 </constant>
5038 <constant id="JVMTI_REFERENCE_FIELD" num="2">
5039 Reference from an object to the value of one of its instance fields.
5040 For references of this kind the <code>referrer_index</code>
5041 parameter to the <internallink id="jvmtiObjectReferenceCallback">
5042 jvmtiObjectReferenceCallback</internallink> is the index of the
5043 the instance field. The index is based on the order of all the
5044 object's fields. This includes all fields of the directly declared
5045 static and instance fields in the class, and includes all fields (both
5046 public and private) fields declared in superclasses and superinterfaces.
5047 The index is thus calculated by summing the index of the field in the directly
5048 declared class (see <functionlink id="GetClassFields"/>), with the total
5049 number of fields (both public and private) declared in all superclasses
5050 and superinterfaces. The index starts at zero.
5051 </constant>
5052 <constant id="JVMTI_REFERENCE_ARRAY_ELEMENT" num="3">
5053 Reference from an array to one of its elements.
5054 For references of this kind the <code>referrer_index</code>
5055 parameter to the <internallink id="jvmtiObjectReferenceCallback">
5056 jvmtiObjectReferenceCallback</internallink> is the array index.
5057 </constant>
5058 <constant id="JVMTI_REFERENCE_CLASS_LOADER" num="4">
5059 Reference from a class to its class loader.
5060 </constant>
5061 <constant id="JVMTI_REFERENCE_SIGNERS" num="5">
5062 Reference from a class to its signers array.
5063 </constant>
5064 <constant id="JVMTI_REFERENCE_PROTECTION_DOMAIN" num="6">
5065 Reference from a class to its protection domain.
5066 </constant>
5067 <constant id="JVMTI_REFERENCE_INTERFACE" num="7">
5068 Reference from a class to one of its interfaces.
5069 </constant>
5070 <constant id="JVMTI_REFERENCE_STATIC_FIELD" num="8">
5071 Reference from a class to the value of one of its static fields.
5072 For references of this kind the <code>referrer_index</code>
5073 parameter to the <internallink id="jvmtiObjectReferenceCallback">
5074 jvmtiObjectReferenceCallback</internallink> is the index of the
5075 the static field. The index is based on the order of all the
5076 object's fields. This includes all fields of the directly declared
5077 static and instance fields in the class, and includes all fields (both
5078 public and private) fields declared in superclasses and superinterfaces.
5079 The index is thus calculated by summing the index of the field in the directly
5080 declared class (see <functionlink id="GetClassFields"/>), with the total
5081 number of fields (both public and private) declared in all superclasses
5082 and superinterfaces. The index starts at zero.
5083 Note: this definition differs from that in the <jvmti/> 1.0 Specification.
5084 <rationale>No known implementations used the 1.0 definition.</rationale>
5085 </constant>
5086 <constant id="JVMTI_REFERENCE_CONSTANT_POOL" num="9">
5087 Reference from a class to a resolved entry in the constant pool.
5088 For references of this kind the <code>referrer_index</code>
5089 parameter to the <internallink id="jvmtiObjectReferenceCallback">
5090 jvmtiObjectReferenceCallback</internallink> is the index into
5091 constant pool table of the class, starting at 1. See
5092 <vmspec chapter="4.4"/>.
5093 </constant>
5094 </constants>
5095
5096 <constants id="jvmtiIterationControl" label="Iteration Control Enumeration" kind="enum">
5097 <constant id="JVMTI_ITERATION_CONTINUE" num="1">
5098 Continue the iteration.
5099 If this is a reference iteration, follow the references of this object.
5100 </constant>
5101 <constant id="JVMTI_ITERATION_IGNORE" num="2">
5102 Continue the iteration.
5103 If this is a reference iteration, ignore the references of this object.
5104 </constant>
5105 <constant id="JVMTI_ITERATION_ABORT" num="0">
5106 Abort the iteration.
5107 </constant>
5108 </constants>
5109 </intro>
5110
5111 <callback id="jvmtiHeapObjectCallback">
5112 <enum>jvmtiIterationControl</enum>
5113 <synopsis>Heap Object Callback</synopsis>
5114 <description>
5115 Agent supplied callback function.
5116 Describes (but does not pass in) an object in the heap.
5117 <p/>
5118 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5119 or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5120 <p/>
5121 See the <internallink id="heapCallbacks">heap callback
5122 function restrictions</internallink>.
5123 </description>
5124 <parameters>
5125 <param id="class_tag">
5126 <jlong/>
5127 <description>
5128 The tag of the class of object (zero if the class is not tagged).
5129 If the object represents a runtime class,
5130 the <code>class_tag</code> is the tag
5131 associated with <code>java.lang.Class</code>
5132 (zero if <code>java.lang.Class</code> is not tagged).
5133 </description>
5134 </param>
5135 <param id="size">
5136 <jlong/>
5137 <description>
5138 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5139 </description>
5140 </param>
5141 <param id="tag_ptr">
5142 <outptr><jlong/></outptr>
5143 <description>
5144 The object tag value, or zero if the object is not tagged.
5145 To set the tag value to be associated with the object
5146 the agent sets the <code>jlong</code> pointed to by the parameter.
5147 </description>
5148 </param>
5149 <param id="user_data">
5150 <outptr><void/></outptr>
5151 <description>
5152 The user supplied data that was passed into the iteration function.
5153 </description>
5154 </param>
5155 </parameters>
5156 </callback>
5157
5158 <callback id="jvmtiHeapRootCallback">
5159 <enum>jvmtiIterationControl</enum>
5160 <synopsis>Heap Root Object Callback</synopsis>
5161 <description>
5162 Agent supplied callback function.
5163 Describes (but does not pass in) an object that is a root for the purposes
5164 of garbage collection.
5165 <p/>
5166 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5167 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5168 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5169 <p/>
5170 See the <internallink id="heapCallbacks">heap callback
5171 function restrictions</internallink>.
5172 </description>
5173 <parameters>
5174 <param id="root_kind">
5175 <enum>jvmtiHeapRootKind</enum>
5176 <description>
5177 The kind of heap root.
5178 </description>
5179 </param>
5180 <param id="class_tag">
5181 <jlong/>
5182 <description>
5183 The tag of the class of object (zero if the class is not tagged).
5184 If the object represents a runtime class, the <code>class_tag</code> is the tag
5185 associated with <code>java.lang.Class</code>
5186 (zero if <code>java.lang.Class</code> is not tagged).
5187 </description>
5188 </param>
5189 <param id="size">
5190 <jlong/>
5191 <description>
5192 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5193 </description>
5194 </param>
5195 <param id="tag_ptr">
5196 <outptr><jlong/></outptr>
5197 <description>
5198 The object tag value, or zero if the object is not tagged.
5199 To set the tag value to be associated with the object
5200 the agent sets the <code>jlong</code> pointed to by the parameter.
5201 </description>
5202 </param>
5203 <param id="user_data">
5204 <outptr><void/></outptr>
5205 <description>
5206 The user supplied data that was passed into the iteration function.
5207 </description>
5208 </param>
5209 </parameters>
5210 </callback>
5211
5212 <callback id="jvmtiStackReferenceCallback">
5213 <enum>jvmtiIterationControl</enum>
5214 <synopsis>Stack Reference Object Callback</synopsis>
5215 <description>
5216 Agent supplied callback function.
5217 Describes (but does not pass in) an object on the stack that is a root for
5218 the purposes of garbage collection.
5219 <p/>
5220 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5221 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5222 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5223 <p/>
5224 See the <internallink id="heapCallbacks">heap callback
5225 function restrictions</internallink>.
5226 </description>
5227 <parameters>
5228 <param id="root_kind">
5229 <enum>jvmtiHeapRootKind</enum>
5230 <description>
5231 The kind of root (either <code>JVMTI_HEAP_ROOT_STACK_LOCAL</code> or
5232 <code>JVMTI_HEAP_ROOT_JNI_LOCAL</code>).
5233 </description>
5234 </param>
5235 <param id="class_tag">
5236 <jlong/>
5237 <description>
5238 The tag of the class of object (zero if the class is not tagged).
5239 If the object represents a runtime class, the <code>class_tag</code> is the tag
5240 associated with <code>java.lang.Class</code>
5241 (zero if <code>java.lang.Class</code> is not tagged).
5242 </description>
5243 </param>
5244 <param id="size">
5245 <jlong/>
5246 <description>
5247 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5248 </description>
5249 </param>
5250 <param id="tag_ptr">
5251 <outptr><jlong/></outptr>
5252 <description>
5253 The object tag value, or zero if the object is not tagged.
5254 To set the tag value to be associated with the object
5255 the agent sets the <code>jlong</code> pointed to by the parameter.
5256 </description>
5257 </param>
5258 <param id="thread_tag">
5259 <jlong/>
5260 <description>
5261 The tag of the thread corresponding to this stack, zero if not tagged.
5262 </description>
5263 </param>
5264 <param id="depth">
5265 <jint/>
5266 <description>
5267 The depth of the frame.
5268 </description>
5269 </param>
5270 <param id="method">
5271 <jmethodID/>
5272 <description>
5273 The method executing in this frame.
5274 </description>
5275 </param>
5276 <param id="slot">
5277 <jint/>
5278 <description>
5279 The slot number.
5280 </description>
5281 </param>
5282 <param id="user_data">
5283 <outptr><void/></outptr>
5284 <description>
5285 The user supplied data that was passed into the iteration function.
5286 </description>
5287 </param>
5288 </parameters>
5289 </callback>
5290
5291 <callback id="jvmtiObjectReferenceCallback">
5292 <enum>jvmtiIterationControl</enum>
5293 <synopsis>Object Reference Callback</synopsis>
5294 <description>
5295 Agent supplied callback function.
5296 Describes a reference from an object (the referrer) to another object
5297 (the referree).
5298 <p/>
5299 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5300 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5301 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5302 <p/>
5303 See the <internallink id="heapCallbacks">heap callback
5304 function restrictions</internallink>.
5305 </description>
5306 <parameters>
5307 <param id="reference_kind">
5308 <enum>jvmtiObjectReferenceKind</enum>
5309 <description>
5310 The type of reference.
5311 </description>
5312 </param>
5313 <param id="class_tag">
5314 <jlong/>
5315 <description>
5316 The tag of the class of referree object (zero if the class is not tagged).
5317 If the referree object represents a runtime class,
5318 the <code>class_tag</code> is the tag
5319 associated with <code>java.lang.Class</code>
5320 (zero if <code>java.lang.Class</code> is not tagged).
5321 </description>
5322 </param>
5323 <param id="size">
5324 <jlong/>
5325 <description>
5326 Size of the referree object (in bytes).
5327 See <functionlink id="GetObjectSize"/>.
5328 </description>
5329 </param>
5330 <param id="tag_ptr">
5331 <outptr><jlong/></outptr>
5332 <description>
5333 The referree object tag value, or zero if the object is not
5334 tagged.
5335 To set the tag value to be associated with the object
5336 the agent sets the <code>jlong</code> pointed to by the parameter.
5337 </description>
5338 </param>
5339 <param id="referrer_tag">
5340 <jlong/>
5341 <description>
5342 The tag of the referrer object, or zero if the referrer
5343 object is not tagged.
5344 </description>
5345 </param>
5346 <param id="referrer_index">
5347 <jint/>
5348 <description>
5349 For references of type <code>JVMTI_REFERENCE_FIELD</code> or
5350 <code>JVMTI_REFERENCE_STATIC_FIELD</code> the index
5351 of the field in the referrer object. The index is based on the
5352 order of all the object's fields - see <internallink
5353 id="JVMTI_REFERENCE_FIELD">JVMTI_REFERENCE_FIELD</internallink>
5354 or <internallink
5355 id="JVMTI_REFERENCE_STATIC_FIELD">JVMTI_REFERENCE_STATIC_FIELD
5356 </internallink> for further description.
5357 <p/>
5358 For references of type <code>JVMTI_REFERENCE_ARRAY_ELEMENT</code>
5359 the array index - see <internallink id="JVMTI_REFERENCE_ARRAY_ELEMENT">
5360 JVMTI_REFERENCE_ARRAY_ELEMENT</internallink> for further description.
5361 <p/>
5362 For references of type <code>JVMTI_REFERENCE_CONSTANT_POOL</code>
5363 the index into the constant pool of the class - see
5364 <internallink id="JVMTI_REFERENCE_CONSTANT_POOL">
5365 JVMTI_REFERENCE_CONSTANT_POOL</internallink> for further
5366 description.
5367 <p/>
5368 For references of other kinds the <code>referrer_index</code> is
5369 <code>-1</code>.
5370 </description>
5371 </param>
5372 <param id="user_data">
5373 <outptr><void/></outptr>
5374 <description>
5375 The user supplied data that was passed into the iteration function.
5376 </description>
5377 </param>
5378 </parameters>
5379 </callback>
5380
5381 <function id="IterateOverObjectsReachableFromObject" num="109">
5382 <synopsis>Iterate Over Objects Reachable From Object</synopsis>
5383 <description>
5384 This function iterates over all objects that are directly
5385 and indirectly reachable from the specified object.
5386 For each object <i>A</i> (known
5387 as the referrer) with a reference to object <i>B</i> the specified
5388 callback function is called to describe the object reference.
5389 The callback is called exactly once for each reference from a referrer;
5390 this is true even if there are reference cycles or multiple paths to
5391 the referrer.
5392 There may be more than one reference between a referrer and a referree,
5393 These may be distinguished by the
5394 <datalink id="jvmtiObjectReferenceCallback.reference_kind"></datalink> and
5395 <datalink id="jvmtiObjectReferenceCallback.referrer_index"></datalink>.
5396 The callback for an object will always occur after the callback for
5397 its referrer.
5398 <p/>
5399 See <functionlink id="FollowReferences"/> for the object
5400 references which are reported.
5401 <p/>
5402 During the execution of this function the state of the heap
5403 does not change: no objects are allocated, no objects are
5404 garbage collected, and the state of objects (including
5405 held values) does not change.
5406 As a result, threads executing Java
5407 programming language code, threads attempting to resume the
5408 execution of Java programming language code, and threads
5409 attempting to execute JNI functions are typically stalled.
5410 </description>
5411 <origin>new</origin>
5412 <capabilities>
5413 <required id="can_tag_objects"></required>
5414 </capabilities>
5415 <parameters>
5416 <param id="object">
5417 <jobject/>
5418 <description>
5419 The object
5420 </description>
5421 </param>
5422 <param id="object_reference_callback">
5423 <ptrtype>
5424 <struct>jvmtiObjectReferenceCallback</struct>
5425 </ptrtype>
5426 <description>
5427 The callback to be called to describe each
5428 object reference.
5429 </description>
5430 </param>
5431 <param id="user_data">
5432 <inbuf>
5433 <void/>
5434 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
5435 </inbuf>
5436 <description>
5437 User supplied data to be passed to the callback.
5438 </description>
5439 </param>
5440 </parameters>
5441 <errors>
5442 </errors>
5443 </function>
5444
5445 <function id="IterateOverReachableObjects" num="110">
5446 <synopsis>Iterate Over Reachable Objects</synopsis>
5447 <description>
5448 This function iterates over the root objects and all objects that
5449 are directly and indirectly reachable from the root objects.
5450 The root objects comprise the set of system classes,
5451 JNI globals, references from thread stacks, and other objects used as roots
5452 for the purposes of garbage collection.
5453 <p/>
5454 For each root the <paramlink id="heap_root_callback"></paramlink>
5455 or <paramlink id="stack_ref_callback"></paramlink> callback is called.
5456 An object can be a root object for more than one reason and in that case
5457 the appropriate callback is called for each reason.
5458 <p/>
5459 For each object reference the <paramlink id="object_ref_callback"></paramlink>
5460 callback function is called to describe the object reference.
5461 The callback is called exactly once for each reference from a referrer;
5462 this is true even if there are reference cycles or multiple paths to
5463 the referrer.
5464 There may be more than one reference between a referrer and a referree,
5465 These may be distinguished by the
5466 <datalink id="jvmtiObjectReferenceCallback.reference_kind"></datalink> and
5467 <datalink id="jvmtiObjectReferenceCallback.referrer_index"></datalink>.
5468 The callback for an object will always occur after the callback for
5469 its referrer.
5470 <p/>
5471 See <functionlink id="FollowReferences"/> for the object
5472 references which are reported.
5473 <p/>
5474 Roots are always reported to the profiler before any object references
5475 are reported. In other words, the <paramlink id="object_ref_callback"></paramlink>
5476 callback will not be called until the appropriate callback has been called
5477 for all roots. If the <paramlink id="object_ref_callback"></paramlink> callback is
5478 specified as <code>NULL</code> then this function returns after
5479 reporting the root objects to the profiler.
5480 <p/>
5481 During the execution of this function the state of the heap
5482 does not change: no objects are allocated, no objects are
5483 garbage collected, and the state of objects (including
5484 held values) does not change.
5485 As a result, threads executing Java
5486 programming language code, threads attempting to resume the
5487 execution of Java programming language code, and threads
5488 attempting to execute JNI functions are typically stalled.
5489 </description>
5490 <origin>new</origin>
5491 <capabilities>
5492 <required id="can_tag_objects"></required>
5493 </capabilities>
5494 <parameters>
5495 <param id="heap_root_callback">
5496 <ptrtype>
5497 <struct>jvmtiHeapRootCallback</struct>
5498 <nullok>do not report heap roots</nullok>
5499 </ptrtype>
5500 <description>
5501 The callback function to be called for each heap root of type
5502 <code>JVMTI_HEAP_ROOT_JNI_GLOBAL</code>,
5503 <code>JVMTI_HEAP_ROOT_SYSTEM_CLASS</code>,
5504 <code>JVMTI_HEAP_ROOT_MONITOR</code>,
5505 <code>JVMTI_HEAP_ROOT_THREAD</code>, or
5506 <code>JVMTI_HEAP_ROOT_OTHER</code>.
5507 </description>
5508 </param>
5509 <param id="stack_ref_callback">
5510 <ptrtype>
5511 <struct>jvmtiStackReferenceCallback</struct>
5512 <nullok>do not report stack references</nullok>
5513 </ptrtype>
5514 <description>
5515 The callback function to be called for each heap root of
5516 <code>JVMTI_HEAP_ROOT_STACK_LOCAL</code> or
5517 <code>JVMTI_HEAP_ROOT_JNI_LOCAL</code>.
5518 </description>
5519 </param>
5520 <param id="object_ref_callback">
5521 <ptrtype>
5522 <struct>jvmtiObjectReferenceCallback</struct>
5523 <nullok>do not follow references from the root objects</nullok>
5524 </ptrtype>
5525 <description>
5526 The callback function to be called for each object reference.
5527 </description>
5528 </param>
5529 <param id="user_data">
5530 <inbuf>
5531 <void/>
5532 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
5533 </inbuf>
5534 <description>
5535 User supplied data to be passed to the callback.
5536 </description>
5537 </param>
5538 </parameters>
5539 <errors>
5540 </errors>
5541 </function>
5542
5543 <function id="IterateOverHeap" num="111">
5544 <synopsis>Iterate Over Heap</synopsis>
5545 <description>
5546 Iterate over all objects in the heap. This includes both reachable and
5547 unreachable objects.
5548 <p/>
5549 The <paramlink id="object_filter"></paramlink> parameter indicates the
5550 objects for which the callback function is called. If this parameter
5551 is <code>JVMTI_HEAP_OBJECT_TAGGED</code> then the callback will only be
5552 called for every object that is tagged. If the parameter is
5553 <code>JVMTI_HEAP_OBJECT_UNTAGGED</code> then the callback will only be
5554 for objects that are not tagged. If the parameter
5555 is <code>JVMTI_HEAP_OBJECT_EITHER</code> then the callback will be
5556 called for every object in the heap, irrespective of whether it is
5557 tagged or not.
5558 <p/>
5559 During the execution of this function the state of the heap
5560 does not change: no objects are allocated, no objects are
5561 garbage collected, and the state of objects (including
5562 held values) does not change.
5563 As a result, threads executing Java
5564 programming language code, threads attempting to resume the
5565 execution of Java programming language code, and threads
5566 attempting to execute JNI functions are typically stalled.
5567 </description>
5568 <origin>new</origin>
5569 <capabilities>
5570 <required id="can_tag_objects"></required>
5571 </capabilities>
5572 <parameters>
5573 <param id="object_filter">
5574 <enum>jvmtiHeapObjectFilter</enum>
5575 <description>
5576 Indicates the objects for which the callback function is called.
5577 </description>
5578 </param>
5579 <param id="heap_object_callback">
5580 <ptrtype>
5581 <struct>jvmtiHeapObjectCallback</struct>
5582 </ptrtype>
5583 <description>
5584 The iterator function to be called for each
5585 object matching the <paramlink id="object_filter"/>.
5586 </description>
5587 </param>
5588 <param id="user_data">
5589 <inbuf>
5590 <void/>
5591 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
5592 </inbuf>
5593 <description>
5594 User supplied data to be passed to the callback.
5595 </description>
5596 </param>
5597 </parameters>
5598 <errors>
5599 </errors>
5600 </function>
5601
5602 <function id="IterateOverInstancesOfClass" num="112">
5603 <synopsis>Iterate Over Instances Of Class</synopsis>
5604 <description>
5605 Iterate over all objects in the heap that are instances of the specified class.
5606 This includes direct instances of the specified class and
5607 instances of all subclasses of the specified class.
5608 This includes both reachable and unreachable objects.
5609 <p/>
5610 The <paramlink id="object_filter"></paramlink> parameter indicates the
5611 objects for which the callback function is called. If this parameter
5612 is <code>JVMTI_HEAP_OBJECT_TAGGED</code> then the callback will only be
5613 called for every object that is tagged. If the parameter is
5614 <code>JVMTI_HEAP_OBJECT_UNTAGGED</code> then the callback will only be
5615 called for objects that are not tagged. If the parameter
5616 is <code>JVMTI_HEAP_OBJECT_EITHER</code> then the callback will be
5617 called for every object in the heap, irrespective of whether it is
5618 tagged or not.
5619 <p/>
5620 During the execution of this function the state of the heap
5621 does not change: no objects are allocated, no objects are
5622 garbage collected, and the state of objects (including
5623 held values) does not change.
5624 As a result, threads executing Java
5625 programming language code, threads attempting to resume the
5626 execution of Java programming language code, and threads
5627 attempting to execute JNI functions are typically stalled.
5628 </description>
5629 <origin>new</origin>
5630 <capabilities>
5631 <required id="can_tag_objects"></required>
5632 </capabilities>
5633 <parameters>
5634 <param id="klass">
5635 <jclass/>
5636 <description>
5637 Iterate over objects of this class only.
5638 </description>
5639 </param>
5640 <param id="object_filter">
5641 <enum>jvmtiHeapObjectFilter</enum>
5642 <description>
5643 Indicates the objects for which the callback function is called.
5644 </description>
5645 </param>
5646 <param id="heap_object_callback">
5647 <ptrtype>
5648 <struct>jvmtiHeapObjectCallback</struct>
5649 </ptrtype>
5650 <description>
5651 The iterator function to be called for each
5652 <paramlink id="klass"/> instance matching
5653 the <paramlink id="object_filter"/>.
5654 </description>
5655 </param>
5656 <param id="user_data">
5657 <inbuf>
5658 <void/>
5659 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
5660 </inbuf>
5661 <description>
5662 User supplied data to be passed to the callback.
5663 </description>
5664 </param>
5665 </parameters>
5666 <errors>
5667 </errors>
5668 </function>
5669
5670 </category>
5671
5672 <category id="local" label="Local Variable">
5673
5674 <intro>
5675 These functions are used to retrieve or set the value of a local variable.
5676 The variable is identified by the depth of the frame containing its
5677 value and the variable's slot number within that frame.
5678 The mapping of variables to
5679 slot numbers can be obtained with the function
5680 <functionlink id="GetLocalVariableTable"></functionlink>.
5681 </intro>
5682
5683 <function id="GetLocalObject" num="21">
5684 <synopsis>Get Local Variable - Object</synopsis>
5685 <description>
5686 This function can be used to retrieve the value of a local
5687 variable whose type is <code>Object</code> or a subclass of <code>Object</code>.
5688 </description>
5689 <origin>jvmdi</origin>
5690 <capabilities>
5691 <required id="can_access_local_variables"></required>
5692 </capabilities>
5693 <parameters>
5694 <param id="thread">
5695 <jthread null="current" frame="frame"/>
5696 <description>
5697 The thread of the frame containing the variable's value.
5698 </description>
5699 </param>
5700 <param id="depth">
5701 <jframeID thread="thread"/>
5702 <description>
5703 The depth of the frame containing the variable's value.
5704 </description>
5705 </param>
5706 <param id="slot">
5707 <jint/>
5708 <description>
5709 The variable's slot number.
5710 </description>
5711 </param>
5712 <param id="value_ptr">
5713 <outptr><jobject/></outptr>
5714 <description>
5715 On return, points to the variable's value.
5716 </description>
5717 </param>
5718 </parameters>
5719 <errors>
5720 <error id="JVMTI_ERROR_INVALID_SLOT">
5721 Invalid <code>slot</code>.
5722 </error>
5723 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5724 The variable type is not
5725 <code>Object</code> or a subclass of <code>Object</code>.
5726 </error>
5727 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5728 Not a visible frame
5729 </error>
5730 </errors>
5731 </function>
5732
5733 <function id="GetLocalInstance" num="155" since="1.2">
5734 <synopsis>Get Local Instance</synopsis>
5735 <description>
5736 This function can be used to retrieve the value of the local object
5737 variable at slot 0 (the "<code>this</code>" object) from non-static
5738 frames. This function can retrieve the "<code>this</code>" object from
5739 native method frames, whereas <code>GetLocalObject()</code> would
5740 return <code>JVMTI_ERROR_OPAQUE_FRAME</code> in those cases.
5741 </description>
5742 <origin>new</origin>
5743 <capabilities>
5744 <required id="can_access_local_variables"></required>
5745 </capabilities>
5746 <parameters>
5747 <param id="thread">
5748 <jthread null="current" frame="frame"/>
5749 <description>
5750 The thread of the frame containing the variable's value.
5751 </description>
5752 </param>
5753 <param id="depth">
5754 <jframeID thread="thread"/>
5755 <description>
5756 The depth of the frame containing the variable's value.
5757 </description>
5758 </param>
5759 <param id="value_ptr">
5760 <outptr><jobject/></outptr>
5761 <description>
5762 On return, points to the variable's value.
5763 </description>
5764 </param>
5765 </parameters>
5766 <errors>
5767 <error id="JVMTI_ERROR_INVALID_SLOT">
5768 If the specified frame is a static method frame.
5769 </error>
5770 </errors>
5771 </function>
5772 <function id="GetLocalInt" num="22">
5773 <synopsis>Get Local Variable - Int</synopsis>
5774 <description>
5775 This function can be used to retrieve the value of a local
5776 variable whose type is <code>int</code>,
5777 <code>short</code>, <code>char</code>, <code>byte</code>, or
5778 <code>boolean</code>.
5779 </description>
5780 <origin>jvmdi</origin>
5781 <capabilities>
5782 <required id="can_access_local_variables"></required>
5783 </capabilities>
5784 <parameters>
5785 <param id="thread">
5786 <jthread null="current" frame="frame"/>
5787 <description>
5788 The thread of the frame containing the variable's value.
5789 </description>
5790 </param>
5791 <param id="depth">
5792 <jframeID thread="thread"/>
5793 <description>
5794 The depth of the frame containing the variable's value.
5795 </description>
5796 </param>
5797 <param id="slot">
5798 <jint/>
5799 <description>
5800 The variable's slot number.
5801 </description>
5802 </param>
5803 <param id="value_ptr">
5804 <outptr><jint/></outptr>
5805 <description>
5806 On return, points to the variable's value.
5807 </description>
5808 </param>
5809 </parameters>
5810 <errors>
5811 <error id="JVMTI_ERROR_INVALID_SLOT">
5812 Invalid <code>slot</code>.
5813 </error>
5814 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5815 The variable type is not
5816 <code>int</code>, <code>short</code>,
5817 <code>char</code>, <code>byte</code>, or
5818 <code>boolean</code>.
5819 </error>
5820 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5821 Not a visible frame
5822 </error>
5823 </errors>
5824 </function>
5825
5826 <function id="GetLocalLong" num="23">
5827 <synopsis>Get Local Variable - Long</synopsis>
5828 <description>
5829 This function can be used to retrieve the value of a local
5830 variable whose type is <code>long</code>.
5831 </description>
5832 <origin>jvmdi</origin>
5833 <capabilities>
5834 <required id="can_access_local_variables"></required>
5835 </capabilities>
5836 <parameters>
5837 <param id="thread">
5838 <jthread null="current" frame="frame"/>
5839 <description>
5840 The thread of the frame containing the variable's value.
5841 </description>
5842 </param>
5843 <param id="depth">
5844 <jframeID thread="thread"/>
5845 <description>
5846 The depth of the frame containing the variable's value.
5847 </description>
5848 </param>
5849 <param id="slot">
5850 <jint/>
5851 <description>
5852 The variable's slot number.
5853 </description>
5854 </param>
5855 <param id="value_ptr">
5856 <outptr><jlong/></outptr>
5857 <description>
5858 On return, points to the variable's value.
5859 </description>
5860 </param>
5861 </parameters>
5862 <errors>
5863 <error id="JVMTI_ERROR_INVALID_SLOT">
5864 Invalid <code>slot</code>.
5865 </error>
5866 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5867 The variable type is not <code>long</code>.
5868 </error>
5869 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5870 Not a visible frame
5871 </error>
5872 </errors>
5873 </function>
5874
5875 <function id="GetLocalFloat" num="24">
5876 <synopsis>Get Local Variable - Float</synopsis>
5877 <description>
5878 This function can be used to retrieve the value of a local
5879 variable whose type is <code>float</code>.
5880 </description>
5881 <origin>jvmdi</origin>
5882 <capabilities>
5883 <required id="can_access_local_variables"></required>
5884 </capabilities>
5885 <parameters>
5886 <param id="thread">
5887 <jthread null="current" frame="frame"/>
5888 <description>
5889 The thread of the frame containing the variable's value.
5890 </description>
5891 </param>
5892 <param id="depth">
5893 <jframeID thread="thread"/>
5894 <description>
5895 The depth of the frame containing the variable's value.
5896 </description>
5897 </param>
5898 <param id="slot">
5899 <jint/>
5900 <description>
5901 The variable's slot number.
5902 </description>
5903 </param>
5904 <param id="value_ptr">
5905 <outptr><jfloat/></outptr>
5906 <description>
5907 On return, points to the variable's value.
5908 </description>
5909 </param>
5910 </parameters>
5911 <errors>
5912 <error id="JVMTI_ERROR_INVALID_SLOT">
5913 Invalid <code>slot</code>.
5914 </error>
5915 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5916 The variable type is not <code>float</code>.
5917 </error>
5918 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5919 Not a visible frame
5920 </error>
5921 </errors>
5922 </function>
5923
5924 <function id="GetLocalDouble" num="25">
5925 <synopsis>Get Local Variable - Double</synopsis>
5926 <description>
5927 This function can be used to retrieve the value of a local
5928 variable whose type is <code>long</code>.
5929 </description>
5930 <origin>jvmdi</origin>
5931 <capabilities>
5932 <required id="can_access_local_variables"></required>
5933 </capabilities>
5934 <parameters>
5935 <param id="thread">
5936 <jthread null="current" frame="frame"/>
5937 <description>
5938 The thread of the frame containing the variable's value.
5939 </description>
5940 </param>
5941 <param id="depth">
5942 <jframeID thread="thread"/>
5943 <description>
5944 The depth of the frame containing the variable's value.
5945 </description>
5946 </param>
5947 <param id="slot">
5948 <jint/>
5949 <description>
5950 The variable's slot number.
5951 </description>
5952 </param>
5953 <param id="value_ptr">
5954 <outptr><jdouble/></outptr>
5955 <description>
5956 On return, points to the variable's value.
5957 </description>
5958 </param>
5959 </parameters>
5960 <errors>
5961 <error id="JVMTI_ERROR_INVALID_SLOT">
5962 Invalid <code>slot</code>.
5963 </error>
5964 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5965 The variable type is not <code>double</code>.
5966 </error>
5967 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5968 Not a visible frame
5969 </error>
5970 </errors>
5971 </function>
5972
5973 <function id="SetLocalObject" num="26">
5974 <synopsis>Set Local Variable - Object</synopsis>
5975 <description>
5976 This function can be used to set the value of a local
5977 variable whose type is <code>Object</code> or a subclass of <code>Object</code>.
5978 </description>
5979 <origin>jvmdi</origin>
5980 <capabilities>
5981 <required id="can_access_local_variables"></required>
5982 </capabilities>
5983 <parameters>
5984 <param id="thread">
5985 <jthread null="current" frame="frame"/>
5986 <description>
5987 The thread of the frame containing the variable's value.
5988 </description>
5989 </param>
5990 <param id="depth">
5991 <jframeID thread="thread"/>
5992 <description>
5993 The depth of the frame containing the variable's value.
5994 </description>
5995 </param>
5996 <param id="slot">
5997 <jint/>
5998 <description>
5999 The variable's slot number.
6000 </description>
6001 </param>
6002 <param id="value">
6003 <jobject/>
6004 <description>
6005 The new value for the variable.
6006 </description>
6007 </param>
6008 </parameters>
6009 <errors>
6010 <error id="JVMTI_ERROR_INVALID_SLOT">
6011 Invalid <code>slot</code>.
6012 </error>
6013 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6014 The variable type is not
6015 <code>Object</code> or a subclass of <code>Object</code>.
6016 </error>
6017 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6018 The supplied <paramlink id="value"/> is not compatible
6019 with the variable type.
6020 </error>
6021 <error id="JVMTI_ERROR_OPAQUE_FRAME">
6022 Not a visible frame
6023 </error>
6024 </errors>
6025 </function>
6026
6027 <function id="SetLocalInt" num="27">
6028 <synopsis>Set Local Variable - Int</synopsis>
6029 <description>
6030 This function can be used to set the value of a local
6031 variable whose type is <code>int</code>,
6032 <code>short</code>, <code>char</code>, <code>byte</code>, or
6033 <code>boolean</code>.
6034 </description>
6035 <origin>jvmdi</origin>
6036 <capabilities>
6037 <required id="can_access_local_variables"></required>
6038 </capabilities>
6039 <parameters>
6040 <param id="thread">
6041 <jthread null="current" frame="frame"/>
6042 <description>
6043 The thread of the frame containing the variable's value.
6044 </description>
6045 </param>
6046 <param id="depth">
6047 <jframeID thread="thread"/>
6048 <description>
6049 The depth of the frame containing the variable's value.
6050 </description>
6051 </param>
6052 <param id="slot">
6053 <jint/>
6054 <description>
6055 The variable's slot number.
6056 </description>
6057 </param>
6058 <param id="value">
6059 <jint/>
6060 <description>
6061 The new value for the variable.
6062 </description>
6063 </param>
6064 </parameters>
6065 <errors>
6066 <error id="JVMTI_ERROR_INVALID_SLOT">
6067 Invalid <code>slot</code>.
6068 </error>
6069 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6070 The variable type is not
6071 <code>int</code>, <code>short</code>,
6072 <code>char</code>, <code>byte</code>, or
6073 <code>boolean</code>.
6074 </error>
6075 <error id="JVMTI_ERROR_OPAQUE_FRAME">
6076 Not a visible frame
6077 </error>
6078 </errors>
6079 </function>
6080
6081 <function id="SetLocalLong" num="28">
6082 <synopsis>Set Local Variable - Long</synopsis>
6083 <description>
6084 This function can be used to set the value of a local
6085 variable whose type is <code>long</code>.
6086 </description>
6087 <origin>jvmdi</origin>
6088 <capabilities>
6089 <required id="can_access_local_variables"></required>
6090 </capabilities>
6091 <parameters>
6092 <param id="thread">
6093 <jthread null="current" frame="frame"/>
6094 <description>
6095 The thread of the frame containing the variable's value.
6096 </description>
6097 </param>
6098 <param id="depth">
6099 <jframeID thread="thread"/>
6100 <description>
6101 The depth of the frame containing the variable's value.
6102 </description>
6103 </param>
6104 <param id="slot">
6105 <jint/>
6106 <description>
6107 The variable's slot number.
6108 </description>
6109 </param>
6110 <param id="value">
6111 <jlong/>
6112 <description>
6113 The new value for the variable.
6114 </description>
6115 </param>
6116 </parameters>
6117 <errors>
6118 <error id="JVMTI_ERROR_INVALID_SLOT">
6119 Invalid <code>slot</code>.
6120 </error>
6121 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6122 The variable type is not <code>long</code>.
6123 </error>
6124 <error id="JVMTI_ERROR_OPAQUE_FRAME">
6125 Not a visible frame
6126 </error>
6127 </errors>
6128 </function>
6129
6130 <function id="SetLocalFloat" num="29">
6131 <synopsis>Set Local Variable - Float</synopsis>
6132 <description>
6133 This function can be used to set the value of a local
6134 variable whose type is <code>float</code>.
6135 </description>
6136 <origin>jvmdi</origin>
6137 <capabilities>
6138 <required id="can_access_local_variables"></required>
6139 </capabilities>
6140 <parameters>
6141 <param id="thread">
6142 <jthread null="current" frame="frame"/>
6143 <description>
6144 The thread of the frame containing the variable's value.
6145 </description>
6146 </param>
6147 <param id="depth">
6148 <jframeID thread="thread"/>
6149 <description>
6150 The depth of the frame containing the variable's value.
6151 </description>
6152 </param>
6153 <param id="slot">
6154 <jint/>
6155 <description>
6156 The variable's slot number.
6157 </description>
6158 </param>
6159 <param id="value">
6160 <jfloat/>
6161 <description>
6162 The new value for the variable.
6163 </description>
6164 </param>
6165 </parameters>
6166 <errors>
6167 <error id="JVMTI_ERROR_INVALID_SLOT">
6168 Invalid <code>slot</code>.
6169 </error>
6170 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6171 The variable type is not <code>float</code>.
6172 </error>
6173 <error id="JVMTI_ERROR_OPAQUE_FRAME">
6174 Not a visible frame
6175 </error>
6176 </errors>
6177 </function>
6178
6179 <function id="SetLocalDouble" num="30">
6180 <synopsis>Set Local Variable - Double</synopsis>
6181 <description>
6182 This function can be used to set the value of a local
6183 variable whose type is <code>double</code>.
6184 </description>
6185 <origin>jvmdi</origin>
6186 <capabilities>
6187 <required id="can_access_local_variables"></required>
6188 </capabilities>
6189 <parameters>
6190 <param id="thread">
6191 <jthread null="current" frame="frame"/>
6192 <description>
6193 The thread of the frame containing the variable's value.
6194 </description>
6195 </param>
6196 <param id="depth">
6197 <jframeID thread="thread"/>
6198 <description>
6199 The depth of the frame containing the variable's value.
6200 </description>
6201 </param>
6202 <param id="slot">
6203 <jint/>
6204 <description>
6205 The variable's slot number.
6206 </description>
6207 </param>
6208 <param id="value">
6209 <jdouble/>
6210 <description>
6211 The new value for the variable.
6212 </description>
6213 </param>
6214 </parameters>
6215 <errors>
6216 <error id="JVMTI_ERROR_INVALID_SLOT">
6217 Invalid <code>slot</code>.
6218 </error>
6219 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6220 The variable type is not <code>double</code>.
6221 </error>
6222 <error id="JVMTI_ERROR_OPAQUE_FRAME">
6223 Not a visible frame
6224 </error>
6225 </errors>
6226 </function>
6227 </category>
6228
6229 <category id="breakpointCategory" label="Breakpoint">
6230
6231 <intro>
6232 </intro>
6233
6234 <function id="SetBreakpoint" num="38">
6235 <synopsis>Set Breakpoint</synopsis>
6236 <description>
6237 Set a breakpoint at the instruction indicated by
6238 <code>method</code> and <code>location</code>.
6239 An instruction can only have one breakpoint.
6240 <p/>
6241 Whenever the designated instruction is about to be executed, a
6242 <eventlink id="Breakpoint"></eventlink> event is generated.
6243 </description>
6244 <origin>jvmdi</origin>
6245 <capabilities>
6246 <required id="can_generate_breakpoint_events"></required>
6247 </capabilities>
6248 <parameters>
6249 <param id="klass">
6250 <jclass method="method"/>
6251 <description>
6252 The class in which to set the breakpoint
6253 </description>
6254 </param>
6255 <param id="method">
6256 <jmethodID class="klass"/>
6257 <description>
6258 The method in which to set the breakpoint
6259 </description>
6260 </param>
6261 <param id="location">
6262 <jlocation/>
6263 <description>
6264 the index of the instruction at which to set the breakpoint
6265
6266 </description>
6267 </param>
6268 </parameters>
6269 <errors>
6270 <error id="JVMTI_ERROR_DUPLICATE">
6271 The designated bytecode already has a breakpoint.
6272 </error>
6273 </errors>
6274 </function>
6275
6276 <function id="ClearBreakpoint" num="39">
6277 <synopsis>Clear Breakpoint</synopsis>
6278 <description>
6279 Clear the breakpoint at the bytecode indicated by
6280 <code>method</code> and <code>location</code>.
6281 </description>
6282 <origin>jvmdi</origin>
6283 <capabilities>
6284 <required id="can_generate_breakpoint_events"></required>
6285 </capabilities>
6286 <parameters>
6287 <param id="klass">
6288 <jclass method="method"/>
6289 <description>
6290 The class in which to clear the breakpoint
6291 </description>
6292 </param>
6293 <param id="method">
6294 <jmethodID class="klass"/>
6295 <description>
6296 The method in which to clear the breakpoint
6297 </description>
6298 </param>
6299 <param id="location">
6300 <jlocation/>
6301 <description>
6302 the index of the instruction at which to clear the breakpoint
6303 </description>
6304 </param>
6305 </parameters>
6306 <errors>
6307 <error id="JVMTI_ERROR_NOT_FOUND">
6308 There's no breakpoint at the designated bytecode.
6309 </error>
6310 </errors>
6311 </function>
6312
6313 </category>
6314
6315 <category id="fieldWatch" label="Watched Field">
6316
6317 <intro>
6318 </intro>
6319
6320 <function id="SetFieldAccessWatch" num="41">
6321 <synopsis>Set Field Access Watch</synopsis>
6322 <description>
6323 Generate a <eventlink id="FieldAccess"></eventlink> event
6324 when the field specified
6325 by <code>klass</code> and
6326 <code>field</code> is about to be accessed.
6327 An event will be generated for each access of the field
6328 until it is canceled with
6329 <functionlink id="ClearFieldAccessWatch"></functionlink>.
6330 Field accesses from Java programming language code or from JNI code are watched,
6331 fields modified by other means are not watched.
6332 Note that <jvmti/> users should be aware that their own field accesses
6333 will trigger the watch.
6334 A field can only have one field access watch set.
6335 Modification of a field is not considered an access--use
6336 <functionlink id="SetFieldModificationWatch"></functionlink>
6337 to monitor modifications.
6338 </description>
6339 <origin>jvmdi</origin>
6340 <capabilities>
6341 <required id="can_generate_field_access_events"></required>
6342 </capabilities>
6343 <parameters>
6344 <param id="klass">
6345 <jclass field="field"/>
6346 <description>
6347 The class containing the field to watch
6348 </description>
6349 </param>
6350 <param id="field">
6351 <jfieldID class="klass"/>
6352 <description>
6353 The field to watch
6354
6355 </description>
6356 </param>
6357 </parameters>
6358 <errors>
6359 <error id="JVMTI_ERROR_DUPLICATE">
6360 The designated field is already being watched for accesses.
6361 </error>
6362 </errors>
6363 </function>
6364
6365 <function id="ClearFieldAccessWatch" num="42">
6366 <synopsis>Clear Field Access Watch</synopsis>
6367 <description>
6368 Cancel a field access watch previously set by
6369 <functionlink id="SetFieldAccessWatch"></functionlink>, on the
6370 field specified
6371 by <code>klass</code> and
6372 <code>field</code>.
6373 </description>
6374 <origin>jvmdi</origin>
6375 <capabilities>
6376 <required id="can_generate_field_access_events"></required>
6377 </capabilities>
6378 <parameters>
6379 <param id="klass">
6380 <jclass field="field"/>
6381 <description>
6382 The class containing the field to watch
6383 </description>
6384 </param>
6385 <param id="field">
6386 <jfieldID class="klass"/>
6387 <description>
6388 The field to watch
6389
6390 </description>
6391 </param>
6392 </parameters>
6393 <errors>
6394 <error id="JVMTI_ERROR_NOT_FOUND">
6395 The designated field is not being watched for accesses.
6396 </error>
6397 </errors>
6398 </function>
6399
6400 <function id="SetFieldModificationWatch" num="43">
6401 <synopsis>Set Field Modification Watch</synopsis>
6402 <description>
6403 Generate a <eventlink id="FieldModification"></eventlink> event
6404 when the field specified
6405 by <code>klass</code> and
6406 <code>field</code> is about to be modified.
6407 An event will be generated for each modification of the field
6408 until it is canceled with
6409 <functionlink id="ClearFieldModificationWatch"></functionlink>.
6410 Field modifications from Java programming language code or from JNI code are watched,
6411 fields modified by other means are not watched.
6412 Note that <jvmti/> users should be aware that their own field modifications
6413 will trigger the watch.
6414 A field can only have one field modification watch set.
6415 </description>
6416 <origin>jvmdi</origin>
6417 <capabilities>
6418 <required id="can_generate_field_modification_events"></required>
6419 </capabilities>
6420 <parameters>
6421 <param id="klass">
6422 <jclass field="field"/>
6423 <description>
6424 The class containing the field to watch
6425 </description>
6426 </param>
6427 <param id="field">
6428 <jfieldID class="klass"/>
6429 <description>
6430 The field to watch
6431
6432 </description>
6433 </param>
6434 </parameters>
6435 <errors>
6436 <error id="JVMTI_ERROR_DUPLICATE">
6437 The designated field is already being watched for modifications.
6438 </error>
6439 </errors>
6440 </function>
6441
6442 <function id="ClearFieldModificationWatch" num="44">
6443 <synopsis>Clear Field Modification Watch</synopsis>
6444 <description>
6445
6446 Cancel a field modification watch previously set by
6447 <functionlink id="SetFieldModificationWatch"></functionlink>, on the
6448 field specified
6449 by <code>klass</code> and
6450 <code>field</code>.
6451 </description>
6452 <origin>jvmdi</origin>
6453 <capabilities>
6454 <required id="can_generate_field_modification_events"></required>
6455 </capabilities>
6456 <parameters>
6457 <param id="klass">
6458 <jclass field="field"/>
6459 <description>
6460 The class containing the field to watch
6461 </description>
6462 </param>
6463 <param id="field">
6464 <jfieldID class="klass"/>
6465 <description>
6466 The field to watch
6467
6468 </description>
6469 </param>
6470 </parameters>
6471 <errors>
6472 <error id="JVMTI_ERROR_NOT_FOUND">
6473 The designated field is not being watched for modifications.
6474 </error>
6475 </errors>
6476 </function>
6477 </category>
6478
6479 <category id="module" label="Module">
6480
6481 <intro>
6482 </intro>
6483
6484 <function id="GetAllModules" num="3" since="9">
6485 <synopsis>Get All Modules</synopsis>
6486 <description>
6487 Return an array of all modules loaded in the virtual machine.
6488 The array includes the unnamed module for each class loader.
6489 The number of modules in the array is returned via
6490 <code>module_count_ptr</code>, and the array itself via
6491 <code>modules_ptr</code>.
6492 <p/>
6493 </description>
6494 <origin>new</origin>
6495 <capabilities>
6496 </capabilities>
6497 <parameters>
6498 <param id="module_count_ptr">
6499 <outptr><jint/></outptr>
6500 <description>
6501 On return, points to the number of returned modules.
6502 </description>
6503 </param>
6504 <param id="modules_ptr">
6505 <allocbuf outcount="module_count_ptr"><jobject/></allocbuf>
6506 <description>
6507 On return, points to an array of references, one
6508 for each module.
6509 </description>
6510 </param>
6511 </parameters>
6512 <errors>
6513 </errors>
6514 </function>
6515
6516 <function id="GetNamedModule" num="40" since="9">
6517 <synopsis>Get Named Module</synopsis>
6518 <description>
6519 Return the <code>java.lang.Module</code> object for a named
6520 module defined to a class loader that contains a given package.
6521 The module is returned via <code>module_ptr</code>.
6522 <p/>
6523 If a named module is defined to the class loader and it
6524 contains the package then that named module is returned,
6525 otherwise <code>NULL</code> is returned.
6526 <p/>
6527 </description>
6528 <origin>new</origin>
6529 <capabilities>
6530 </capabilities>
6531 <parameters>
6532 <param id="class_loader">
6533 <ptrtype>
6534 <jobject/>
6535 <nullok>the bootstrap loader is assumed</nullok>
6536 </ptrtype>
6537 <description>
6538 A class loader.
6539 If the <code>class_loader</code> is not <code>NULL</code>
6540 or a subclass of <code>java.lang.ClassLoader</code>
6541 this function returns
6542 <errorlink id="JVMTI_ERROR_ILLEGAL_ARGUMENT"></errorlink>.
6543 </description>
6544 </param>
6545 <param id="package_name">
6546 <inbuf><char/></inbuf>
6547 <description>
6548 The name of the package, encoded as a
6549 <internallink id="mUTF">modified UTF-8</internallink> string.
6550 The package name is in internal form (JVMS 4.2.1);
6551 identifiers are separated by forward slashes rather than periods.
6552 </description>
6553 </param>
6554 <param id="module_ptr">
6555 <outptr><jobject/></outptr>
6556 <description>
6557 On return, points to a <code>java.lang.Module</code> object
6558 or points to <code>NULL</code>.
6559 </description>
6560 </param>
6561 </parameters>
6562 <errors>
6563 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
6564 If class loader is not <code>NULL</code> and is not a class loader object.
6565 </error>
6566 </errors>
6567 </function>
6568
6569 <function id="AddModuleReads" num="94" since="9">
6570 <synopsis>Add Module Reads</synopsis>
6571 <description>
6572 Update a module to read another module. This function is a no-op
6573 when <paramlink id="module"></paramlink> is an unnamed module.
6574 This function facilitates the instrumentation of code
6575 in named modules where that instrumentation requires
6576 expanding the set of modules that a module reads.
6577 </description>
6578 <origin>new</origin>
6579 <capabilities>
6580 </capabilities>
6581 <parameters>
6582 <param id="module">
6583 <ptrtype><jobject/></ptrtype>
6584 <description>
6585 The module to update.
6586 </description>
6587 </param>
6588 <param id="to_module">
6589 <ptrtype><jobject/></ptrtype>
6590 <description>
6591 The additional module to read.
6592 </description>
6593 </param>
6594 </parameters>
6595 <errors>
6596 <error id="JVMTI_ERROR_INVALID_MODULE">
6597 If <paramlink id="module"></paramlink> is not a module object.
6598 </error>
6599 <error id="JVMTI_ERROR_INVALID_MODULE">
6600 If <paramlink id="to_module"></paramlink> is not a module object.
6601 </error>
6602 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE">
6603 if the module cannot be modified.
6604 See <functionlink id="IsModifiableModule"/>.
6605 </error>
6606 </errors>
6607 </function>
6608
6609 <function id="AddModuleExports" num="95" since="9">
6610 <synopsis>Add Module Exports</synopsis>
6611 <description>
6612 Update a module to export a package to another module.
6613 This function is a no-op when <paramlink id="module"></paramlink>
6614 is an unnamed module or an open module.
6615 This function facilitates the instrumentation of code
6616 in named modules where that instrumentation requires
6617 expanding the set of packages that a module exports.
6618 </description>
6619 <origin>new</origin>
6620 <capabilities>
6621 </capabilities>
6622 <parameters>
6623 <param id="module">
6624 <ptrtype><jobject/></ptrtype>
6625 <description>
6626 The module to update.
6627 </description>
6628 </param>
6629 <param id="pkg_name">
6630 <inbuf><char/></inbuf>
6631 <description>
6632 The exported package name.
6633 </description>
6634 </param>
6635 <param id="to_module">
6636 <ptrtype><jobject/></ptrtype>
6637 <description>
6638 The module the package is exported to.
6639 If the <code>to_module</code> is not a subclass of
6640 <code>java.lang.Module</code> this function returns
6641 <errorlink id="JVMTI_ERROR_INVALID_MODULE"></errorlink>.
6642 </description>
6643 </param>
6644 </parameters>
6645 <errors>
6646 <error id="JVMTI_ERROR_INVALID_MODULE">
6647 If <paramlink id="module"></paramlink> is not a module object.
6648 </error>
6649 <error id="JVMTI_ERROR_INVALID_MODULE">
6650 If <paramlink id="to_module"></paramlink> is not a module object.
6651 </error>
6652 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
6653 If the package <paramlink id="pkg_name"></paramlink>
6654 does not belong to the module.
6655 </error>
6656 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE">
6657 if the module cannot be modified.
6658 See <functionlink id="IsModifiableModule"/>.
6659 </error>
6660 </errors>
6661 </function>
6662
6663 <function id="AddModuleOpens" num="96" since="9">
6664 <synopsis>Add Module Opens</synopsis>
6665 <description>
6666 Update a module to open a package to another module.
6667 This function is a no-op when <paramlink id="module"></paramlink>
6668 is an unnamed module or an open module.
6669 This function facilitates the instrumentation of code
6670 in modules where that instrumentation requires
6671 expanding the set of packages that a module opens to
6672 other modules.
6673 </description>
6674 <origin>new</origin>
6675 <capabilities>
6676 </capabilities>
6677 <parameters>
6678 <param id="module">
6679 <ptrtype><jobject/></ptrtype>
6680 <description>
6681 The module to update.
6682 </description>
6683 </param>
6684 <param id="pkg_name">
6685 <inbuf><char/></inbuf>
6686 <description>
6687 The package name of the package to open.
6688 </description>
6689 </param>
6690 <param id="to_module">
6691 <ptrtype><jobject/></ptrtype>
6692 <description>
6693 The module with the package to open.
6694 If the <code>to_module</code> is not a subclass of
6695 <code>java.lang.Module</code> this function returns
6696 <errorlink id="JVMTI_ERROR_INVALID_MODULE"></errorlink>.
6697 </description>
6698 </param>
6699 </parameters>
6700 <errors>
6701 <error id="JVMTI_ERROR_INVALID_MODULE">
6702 If <paramlink id="module"></paramlink> is not a module object.
6703 </error>
6704 <error id="JVMTI_ERROR_INVALID_MODULE">
6705 If <paramlink id="to_module"></paramlink> is not a module object.
6706 </error>
6707 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
6708 If the package <paramlink id="pkg_name"></paramlink>
6709 does not belong to the module.
6710 </error>
6711 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE">
6712 if the module cannot be modified.
6713 See <functionlink id="IsModifiableModule"/>.
6714 </error>
6715 </errors>
6716 </function>
6717
6718 <function id="AddModuleUses" num="97" since="9">
6719 <synopsis>Add Module Uses</synopsis>
6720 <description>
6721 Updates a module to add a service to the set of services that
6722 a module uses. This function is a no-op when the module
6723 is an unnamed module.
6724 This function facilitates the instrumentation of code
6725 in named modules where that instrumentation requires
6726 expanding the set of services that a module is using.
6727 </description>
6728 <origin>new</origin>
6729 <capabilities>
6730 </capabilities>
6731 <parameters>
6732 <param id="module">
6733 <ptrtype><jobject/></ptrtype>
6734 <description>
6735 The module to update.
6736 </description>
6737 </param>
6738 <param id="service">
6739 <ptrtype><jclass/></ptrtype>
6740 <description>
6741 The service to use.
6742 </description>
6743 </param>
6744 </parameters>
6745 <errors>
6746 <error id="JVMTI_ERROR_INVALID_MODULE">
6747 If <paramlink id="module"></paramlink> is not a module object.
6748 </error>
6749 <error id="JVMTI_ERROR_INVALID_CLASS">
6750 If <paramlink id="service"></paramlink> is not a class object.
6751 </error>
6752 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE">
6753 if the module cannot be modified.
6754 See <functionlink id="IsModifiableModule"/>.
6755 </error>
6756 </errors>
6757 </function>
6758
6759 <function id="AddModuleProvides" num="98" since="9">
6760 <synopsis>Add Module Provides</synopsis>
6761 <description>
6762 Updates a module to add a service to the set of services that
6763 a module provides. This function is a no-op when the module
6764 is an unnamed module.
6765 This function facilitates the instrumentation of code
6766 in named modules where that instrumentation requires
6767 changes to the services that are provided.
6768 </description>
6769 <origin>new</origin>
6770 <capabilities>
6771 </capabilities>
6772 <parameters>
6773 <param id="module">
6774 <ptrtype><jobject/></ptrtype>
6775 <description>
6776 The module to update.
6777 </description>
6778 </param>
6779 <param id="service">
6780 <ptrtype><jclass/></ptrtype>
6781 <description>
6782 The service to provide.
6783 </description>
6784 </param>
6785 <param id="impl_class">
6786 <ptrtype><jclass/></ptrtype>
6787 <description>
6788 The implementation class for the provided service.
6789 </description>
6790 </param>
6791 </parameters>
6792 <errors>
6793 <error id="JVMTI_ERROR_INVALID_MODULE">
6794 If <paramlink id="module"></paramlink> is not a module object.
6795 </error>
6796 <error id="JVMTI_ERROR_INVALID_CLASS">
6797 If <paramlink id="service"></paramlink> is not a class object.
6798 </error>
6799 <error id="JVMTI_ERROR_INVALID_CLASS">
6800 If <paramlink id="impl_class"></paramlink> is not a class object.
6801 </error>
6802 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE">
6803 if the module cannot be modified.
6804 See <functionlink id="IsModifiableModule"/>.
6805 </error>
6806 </errors>
6807 </function>
6808
6809 <function id="IsModifiableModule" num="99" since="9">
6810 <synopsis>Is Modifiable Module</synopsis>
6811 <description>
6812 Determines whether a module is modifiable.
6813 If a module is modifiable then this module can be updated with
6814 <functionlink id="AddModuleReads"/>, <functionlink id="AddModuleExports"/>,
6815 <functionlink id="AddModuleOpens"/>, <functionlink id="AddModuleUses"/>,
6816 and <functionlink id="AddModuleProvides"/>. If a module is not modifiable
6817 then the module can not be updated with these functions. The result of
6818 this function is always <code>JNI_TRUE</code> when called to determine
6819 if an unnamed module is modifiable.
6820 </description>
6821 <origin>new</origin>
6822 <capabilities>
6823 </capabilities>
6824 <parameters>
6825 <param id="module">
6826 <ptrtype><jobject/></ptrtype>
6827 <description>
6828 The module to query.
6829 </description>
6830 </param>
6831 <param id="is_modifiable_module_ptr">
6832 <outptr><jboolean/></outptr>
6833 <description>
6834 On return, points to the boolean result of this function.
6835 </description>
6836 </param>
6837 </parameters>
6838 <errors>
6839 <error id="JVMTI_ERROR_INVALID_MODULE">
6840 If <paramlink id="module"></paramlink> is not a module object.
6841 </error>
6842 </errors>
6843 </function>
6844
6845 </category>
6846
6847 <category id="class" label="Class">
6848 <function id="GetLoadedClasses" jkernel="yes" num="78">
6849 <synopsis>Get Loaded Classes</synopsis>
6850 <description>
6851 Return an array of all classes loaded in the virtual machine.
6852 The number of classes in the array is returned via
6853 <code>class_count_ptr</code>, and the array itself via
6854 <code>classes_ptr</code>.
6855 <p/>
6856 A class or interface creation can be triggered by one of the following:
6857 <ul>
6858 <li>By loading and deriving a class from a <code>class</code> file representation
6859 using a class loader (see <vmspec chapter="5.3"/>).</li>
6860 <li>By invoking <externallink id="../api/java.base/java/lang/invoke/MethodHandles.Lookup.html#defineHiddenClass(byte[],boolean,java.lang.invoke.MethodHandles.Lookup.ClassOption...)">Lookup::defineHiddenClass</externallink>
6861 that creates a hidden class or interface from a <code>class</code> file representation.</li>
6862 <li>By invoking methods in certain Java SE Platform APIs such as reflection.</li>
6863 </ul>
6864 <p/>
6865 An array class is created directly by the Java virtual machine. The creation
6866 can be triggered by using class loaders or by invoking methods in certain
6867 Java SE Platform APIs such as reflection.
6868 <p/>
6869 The returned list includes all classes and interfaces, including
6870 <externallink id="../api/java.base/java/lang/Class.html#isHidden()">
6871 hidden classes or interfaces</externallink>,
6872 and also array classes of all types
6873 (including arrays of primitive types).
6874 Primitive classes (for example, <code>java.lang.Integer.TYPE</code>) are
6875 <i>not</i> included in the returned list.
6876 </description>
6877 <origin>jvmdi</origin>
6878 <capabilities>
6879 </capabilities>
6880 <parameters>
6881 <param id="class_count_ptr">
6882 <outptr><jint/></outptr>
6883 <description>
6884 On return, points to the number of classes.
6885 </description>
6886 </param>
6887 <param id="classes_ptr">
6888 <allocbuf outcount="class_count_ptr"><jclass/></allocbuf>
6889 <description>
6890 On return, points to an array of references, one
6891 for each class.
6892 </description>
6893 </param>
6894 </parameters>
6895 <errors>
6896 </errors>
6897 </function>
6898
6899 <function id="GetClassLoaderClasses" jkernel="yes" num="79">
6900 <synopsis>Get Classloader Classes</synopsis>
6901 <description>
6902 Returns an array of all classes which this class loader
6903 can find by name via
6904 <externallink id="../api/java.base/java/lang/ClassLoader.html#loadClass(java.lang.String,boolean)">ClassLoader::loadClass</externallink>,
6905 <externallink id="../api/java.base/java/lang/Class.html#forName(java.lang.String,boolean,java.lang.ClassLoader)">Class::forName</externallink> and bytecode linkage.
6906 That is, all classes for which <code>initiating_loader</code>
6907 has been recorded as an initiating loader.
6908 Each class in the returned array was created by this class loader,
6909 either by defining it directly or by delegation to another class loader.
6910 See <vmspec chapter="5.3"/>.
6911 <p/>
6912 The returned list does not include
6913 <externallink id="../api/java.base/java/lang/Class.html#isHidden()">hidden
6914 classes or interfaces</externallink> or array classes whose
6915 element type is a hidden class or interface as they cannot be discovered
6916 by any class loader.
6917 <p/>
6918 The number of classes in the array is returned via
6919 <code>class_count_ptr</code>, and the array itself via
6920 <code>classes_ptr</code>.
6921 <p/>
6922 See <externallink id="../api/java.base/java/lang/invoke/MethodHandles.Lookup.html#defineHiddenClass(byte[],boolean,java.lang.invoke.MethodHandles.Lookup.ClassOption...)">Lookup::defineHiddenClass</externallink>.
6923 </description>
6924 <origin>jvmdi</origin>
6925 <capabilities>
6926 </capabilities>
6927 <parameters>
6928 <param id="initiating_loader">
6929 <ptrtype>
6930 <jobject/>
6931 <nullok>the classes initiated by the bootstrap loader will be returned</nullok>
6932 </ptrtype>
6933 <description>
6934 An initiating class loader.
6935 </description>
6936 </param>
6937 <param id="class_count_ptr">
6938 <outptr><jint/></outptr>
6939 <description>
6940 On return, points to the number of classes.
6941 </description>
6942 </param>
6943 <param id="classes_ptr">
6944 <allocbuf outcount="class_count_ptr"><jclass/></allocbuf>
6945 <description>
6946 On return, points to an array of references, one
6947 for each class.
6948 </description>
6949 </param>
6950 </parameters>
6951 <errors>
6952 </errors>
6953 </function>
6954
6955 <function id="GetClassSignature" phase="start" num="48">
6956 <synopsis>Get Class Signature</synopsis>
6957 <description>
6958 Return the name and the generic signature of the class indicated by <code>klass</code>.
6959 <p/>
6960 If the class is a class or interface, then:
6961 <ul>
6962 <li>If the class or interface is not <externallink id="../api/java.base/java/lang/Class.html#isHidden()">hidden</externallink>,
6963 then the returned name is the <externallink id="jni/types.html#type-signatures">
6964 JNI type signature</externallink>.
6965 For example, java.util.List is "Ljava/util/List;"
6966 </li>
6967 <li>If the class or interface is <externallink id="../api/java.base/java/lang/Class.html#isHidden()">hidden</externallink>,
6968 then the returned name is a string of the form:
6969 <code>"L" + N + "." + S + ";"</code>
6970 where <code>N</code> is the binary name encoded in internal form (JVMS 4.2.1)
6971 indicated by the <code>class</code> file passed to
6972 <externallink id="../api/java.base/java/lang/invoke/MethodHandles.Lookup.html#defineHiddenClass(byte[],boolean,java.lang.invoke.MethodHandles.Lookup.ClassOption...)">Lookup::defineHiddenClass</externallink>,
6973 and <code>S</code> is an unqualified name.
6974 The returned name is not a type descriptor and does not conform to JVMS 4.3.2.
6975 For example, com.foo.Foo/AnySuffix is "Lcom/foo/Foo.AnySuffix;"
6976 </li>
6977 </ul>
6978 <p/>
6979 If the class indicated by <code>klass</code> represents an array class, then
6980 the returned name is a string consisting of one or more "<code>[</code>" characters
6981 representing the depth of the array nesting, followed by the class signature
6982 of the element type. For example the class signature of java.lang.String[] is
6983 "[Ljava/lang/String;" and that of int[] is "[I".
6984 <p/>
6985 If the class indicated by <code>klass</code> represents primitive type or <code>void</code>,
6986 then the returned name is the <externallink id="jni/types.html#type-signatures">
6987 type signature character of the corresponding primitive type</externallink>.
6988 For example, java.lang.Integer.TYPE is "I".
6989 </description>
6990 <origin>jvmdiClone</origin>
6991 <capabilities>
6992 </capabilities>
6993 <parameters>
6994 <param id="klass">
6995 <jclass/>
6996 <description>
6997 The class to query.
6998 </description>
6999 </param>
7000 <param id="signature_ptr">
7001 <allocbuf>
7002 <char/>
7003 <nullok>the signature is not returned</nullok>
7004 </allocbuf>
7005 <description>
7006 On return, points to the JNI type signature of the class, encoded as a
7007 <internallink id="mUTF">modified UTF-8</internallink> string.
7008 </description>
7009 </param>
7010 <param id="generic_ptr">
7011 <allocbuf>
7012 <char/>
7013 <nullok>the generic signature is not returned</nullok>
7014 </allocbuf>
7015 <description>
7016 On return, points to the generic signature of the class, encoded as a
7017 <internallink id="mUTF">modified UTF-8</internallink> string.
7018 If there is no generic signature attribute for the class, then,
7019 on return, points to <code>NULL</code>.
7020 </description>
7021 </param>
7022 </parameters>
7023 <errors>
7024 </errors>
7025 </function>
7026
7027 <function id="GetClassStatus" phase="start" num="49">
7028 <synopsis>Get Class Status</synopsis>
7029 <description>
7030 Get the status of the class. Zero or more of the following bits can be
7031 set.
7032 <constants id="jvmtiClassStatus" label="Class Status Flags" kind="bits">
7033 <constant id="JVMTI_CLASS_STATUS_VERIFIED" num="1">
7034 Class bytecodes have been verified
7035 </constant>
7036 <constant id="JVMTI_CLASS_STATUS_PREPARED" num="2">
7037 Class preparation is complete
7038 </constant>
7039 <constant id="JVMTI_CLASS_STATUS_INITIALIZED" num="4">
7040 Class initialization is complete. Static initializer has been run.
7041 </constant>
7042 <constant id="JVMTI_CLASS_STATUS_ERROR" num="8">
7043 Error during initialization makes class unusable
7044 </constant>
7045 <constant id="JVMTI_CLASS_STATUS_ARRAY" num="16">
7046 Class is an array. If set, all other bits are zero.
7047 </constant>
7048 <constant id="JVMTI_CLASS_STATUS_PRIMITIVE" num="32">
7049 Class is a primitive class (for example, <code>java.lang.Integer.TYPE</code>).
7050 If set, all other bits are zero.
7051 </constant>
7052 </constants>
7053 </description>
7054 <origin>jvmdi</origin>
7055 <capabilities>
7056 </capabilities>
7057 <parameters>
7058 <param id="klass">
7059 <jclass/>
7060 <description>
7061 The class to query.
7062 </description>
7063 </param>
7064 <param id="status_ptr">
7065 <outptr><jint/></outptr>
7066 <description>
7067 On return, points to the current state of this class as one or
7068 more of the <internallink id="jvmtiClassStatus">class status flags</internallink>.
7069 </description>
7070 </param>
7071 </parameters>
7072 <errors>
7073 </errors>
7074 </function>
7075
7076 <function id="GetSourceFileName" phase="start" num="50">
7077 <synopsis>Get Source File Name</synopsis>
7078 <description>
7079 For the class indicated by <code>klass</code>, return the source file
7080 name via <code>source_name_ptr</code>. The returned string
7081 is a file name only and never contains a directory name.
7082 <p/>
7083 For primitive classes (for example, <code>java.lang.Integer.TYPE</code>)
7084 and for arrays this function returns
7085 <errorlink id="JVMTI_ERROR_ABSENT_INFORMATION"></errorlink>.
7086 </description>
7087 <origin>jvmdi</origin>
7088 <capabilities>
7089 <required id="can_get_source_file_name"></required>
7090 </capabilities>
7091 <parameters>
7092 <param id="klass">
7093 <jclass/>
7094 <description>
7095 The class to query.
7096 </description>
7097 </param>
7098 <param id="source_name_ptr">
7099 <allocbuf><char/></allocbuf>
7100 <description>
7101 On return, points to the class's source file name, encoded as a
7102 <internallink id="mUTF">modified UTF-8</internallink> string.
7103 </description>
7104 </param>
7105 </parameters>
7106 <errors>
7107 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7108 Class information does not include a source file name. This includes
7109 cases where the class is an array class or primitive class.
7110 </error>
7111 </errors>
7112 </function>
7113
7114 <function id="GetClassModifiers" phase="start" num="51">
7115 <synopsis>Get Class Modifiers</synopsis>
7116 <description>
7117 For the class indicated by <code>klass</code>, return the access
7118 flags
7119 via <code>modifiers_ptr</code>.
7120 Access flags are defined in <vmspec chapter="4"/>.
7121 <p/>
7122 If the class is an array class, then its public, private, and protected
7123 modifiers are the same as those of its component type. For arrays of
7124 primitives, this component type is represented by one of the primitive
7125 classes (for example, <code>java.lang.Integer.TYPE</code>).
7126 <p/>
7127 If the class is a primitive class, its public modifier is always true,
7128 and its protected and private modifiers are always false.
7129 <p/>
7130 If the class is an array class or a primitive class then its final
7131 modifier is always true and its interface modifier is always false.
7132 The values of its other modifiers are not determined by this specification.
7133
7134 </description>
7135 <origin>jvmdi</origin>
7136 <capabilities>
7137 </capabilities>
7138 <parameters>
7139 <param id="klass">
7140 <jclass/>
7141 <description>
7142 The class to query.
7143 </description>
7144 </param>
7145 <param id="modifiers_ptr">
7146 <outptr><jint/></outptr>
7147 <description>
7148 On return, points to the current access flags of this class.
7149
7150 </description>
7151 </param>
7152 </parameters>
7153 <errors>
7154 </errors>
7155 </function>
7156
7157 <function id="GetClassMethods" phase="start" num="52">
7158 <synopsis>Get Class Methods</synopsis>
7159 <description>
7160 For the class indicated by <code>klass</code>, return a count of
7161 methods via <code>method_count_ptr</code> and a list of
7162 method IDs via <code>methods_ptr</code>. The method list contains
7163 constructors and static initializers as well as true methods.
7164 Only directly declared methods are returned (not inherited methods).
7165 An empty method list is returned for array classes and primitive classes
7166 (for example, <code>java.lang.Integer.TYPE</code>).
7167 </description>
7168 <origin>jvmdi</origin>
7169 <capabilities>
7170 <capability id="can_maintain_original_method_order"/>
7171 </capabilities>
7172 <parameters>
7173 <param id="klass">
7174 <jclass/>
7175 <description>
7176 The class to query.
7177 </description>
7178 </param>
7179 <param id="method_count_ptr">
7180 <outptr><jint/></outptr>
7181 <description>
7182 On return, points to the number of methods declared in this class.
7183 </description>
7184 </param>
7185 <param id="methods_ptr">
7186 <allocbuf outcount="method_count_ptr"><jmethodID class="klass"/></allocbuf>
7187 <description>
7188 On return, points to the method ID array.
7189 </description>
7190 </param>
7191 </parameters>
7192 <errors>
7193 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
7194 <paramlink id="klass"></paramlink> is not prepared.
7195 </error>
7196 </errors>
7197 </function>
7198
7199 <function id="GetClassFields" phase="start" num="53">
7200 <synopsis>Get Class Fields</synopsis>
7201 <description>
7202 For the class indicated by <code>klass</code>, return a count of fields
7203 via <code>field_count_ptr</code> and a list of field IDs via
7204 <code>fields_ptr</code>.
7205 Only directly declared fields are returned (not inherited fields).
7206 Fields are returned in the order they occur in the class file.
7207 An empty field list is returned for array classes and primitive classes
7208 (for example, <code>java.lang.Integer.TYPE</code>).
7209 Use JNI to determine the length of an array.
7210 </description>
7211 <origin>jvmdi</origin>
7212 <capabilities>
7213 </capabilities>
7214 <parameters>
7215 <param id="klass">
7216 <jclass/>
7217 <description>
7218 The class to query.
7219 </description>
7220 </param>
7221 <param id="field_count_ptr">
7222 <outptr><jint/></outptr>
7223 <description>
7224 On return, points to the number of fields declared in this class.
7225 </description>
7226 </param>
7227 <param id="fields_ptr">
7228 <allocbuf outcount="field_count_ptr"><jfieldID/></allocbuf>
7229 <description>
7230 On return, points to the field ID array.
7231 </description>
7232 </param>
7233 </parameters>
7234 <errors>
7235 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
7236 <paramlink id="klass"></paramlink> is not prepared.
7237 </error>
7238 </errors>
7239 </function>
7240
7241 <function id="GetImplementedInterfaces" phase="start" num="54">
7242 <synopsis>Get Implemented Interfaces</synopsis>
7243 <description>
7244 Return the direct super-interfaces of this class. For a class, this
7245 function returns the interfaces declared in its <code>implements</code>
7246 clause. For an interface, this function returns the interfaces declared in
7247 its <code>extends</code> clause.
7248 An empty interface list is returned for array classes and primitive classes
7249 (for example, <code>java.lang.Integer.TYPE</code>).
7250 </description>
7251 <origin>jvmdi</origin>
7252 <capabilities>
7253 </capabilities>
7254 <parameters>
7255 <param id="klass">
7256 <jclass/>
7257 <description>
7258 The class to query.
7259 </description>
7260 </param>
7261 <param id="interface_count_ptr">
7262 <outptr><jint/></outptr>
7263 <description>
7264 On return, points to the number of interfaces.
7265 </description>
7266 </param>
7267 <param id="interfaces_ptr">
7268 <allocbuf outcount="interface_count_ptr"><jclass/></allocbuf>
7269 <description>
7270 On return, points to the interface array.
7271 </description>
7272 </param>
7273 </parameters>
7274 <errors>
7275 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
7276 <paramlink id="klass"></paramlink> is not prepared.
7277 </error>
7278 </errors>
7279 </function>
7280
7281 <function id="GetClassVersionNumbers" phase="start" num="145" since="1.1">
7282 <synopsis>Get Class Version Numbers</synopsis>
7283 <description>
7284 For the class indicated by <code>klass</code>,
7285 return the minor and major version numbers,
7286 as defined in
7287 <vmspec chapter="4"/>.
7288 </description>
7289 <origin>new</origin>
7290 <capabilities>
7291 </capabilities>
7292 <parameters>
7293 <param id="klass">
7294 <jclass/>
7295 <description>
7296 The class to query.
7297 </description>
7298 </param>
7299 <param id="minor_version_ptr">
7300 <outptr><jint/></outptr>
7301 <description>
7302 On return, points to the value of the
7303 <code>minor_version</code> item of the
7304 Class File Format.
7305 Note: to be consistent with the Class File Format,
7306 the minor version number is the first parameter.
7307 </description>
7308 </param>
7309 <param id="major_version_ptr">
7310 <outptr><jint/></outptr>
7311 <description>
7312 On return, points to the value of the
7313 <code>major_version</code> item of the
7314 Class File Format.
7315 </description>
7316 </param>
7317 </parameters>
7318 <errors>
7319 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7320 The class is a primitive or array class.
7321 </error>
7322 </errors>
7323 </function>
7324
7325 <function id="GetConstantPool" phase="start" num="146" since="1.1">
7326 <synopsis>Get Constant Pool</synopsis>
7327 <description>
7328 For the class indicated by <code>klass</code>,
7329 return the raw bytes of the constant pool in the format of the
7330 <code>constant_pool</code> item of
7331 <vmspec chapter="4"/>.
7332 The format of the constant pool may differ between versions
7333 of the Class File Format, so, the
7334 <functionlink id="GetClassVersionNumbers">minor and major
7335 class version numbers</functionlink> should be checked for
7336 compatibility.
7337 <p/>
7338 The returned constant pool might not have the same layout or
7339 contents as the constant pool in the defining class file.
7340 The constant pool returned by GetConstantPool() may have
7341 more or fewer entries than the defining constant pool.
7342 Entries may be in a different order.
7343 The constant pool returned by GetConstantPool() will match the
7344 constant pool used by
7345 <functionlink id="GetBytecodes">GetBytecodes()</functionlink>.
7346 That is, the bytecodes returned by GetBytecodes() will have
7347 constant pool indices which refer to constant pool entries returned
7348 by GetConstantPool().
7349 Note that since <functionlink id="RetransformClasses"/>
7350 and <functionlink id="RedefineClasses"/> can change
7351 the constant pool, the constant pool returned by this function
7352 can change accordingly. Thus, the correspondence between
7353 GetConstantPool() and GetBytecodes() does not hold if there
7354 is an intervening class retransformation or redefinition.
7355 The value of a constant pool entry used by a given bytecode will
7356 match that of the defining class file (even if the indices don't match).
7357 Constant pool entries which are not used directly or indirectly by
7358 bytecodes (for example, UTF-8 strings associated with annotations) are
7359 not required to exist in the returned constant pool.
7360 </description>
7361 <origin>new</origin>
7362 <capabilities>
7363 <required id="can_get_constant_pool"></required>
7364 </capabilities>
7365 <parameters>
7366 <param id="klass">
7367 <jclass/>
7368 <description>
7369 The class to query.
7370 </description>
7371 </param>
7372 <param id="constant_pool_count_ptr">
7373 <outptr><jint/></outptr>
7374 <description>
7375 On return, points to the number of entries
7376 in the constant pool table plus one.
7377 This corresponds to the <code>constant_pool_count</code>
7378 item of the Class File Format.
7379 </description>
7380 </param>
7381 <param id="constant_pool_byte_count_ptr">
7382 <outptr><jint/></outptr>
7383 <description>
7384 On return, points to the number of bytes
7385 in the returned raw constant pool.
7386 </description>
7387 </param>
7388 <param id="constant_pool_bytes_ptr">
7389 <allocbuf outcount="constant_pool_byte_count_ptr"><uchar/></allocbuf>
7390 <description>
7391 On return, points to the raw constant pool, that is the bytes
7392 defined by the <code>constant_pool</code> item of the
7393 Class File Format
7394 </description>
7395 </param>
7396 </parameters>
7397 <errors>
7398 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7399 The class is a primitive or array class.
7400 </error>
7401 </errors>
7402 </function>
7403
7404 <function id="IsInterface" phase="start" num="55">
7405 <synopsis>Is Interface</synopsis>
7406 <description>
7407 Determines whether a class object reference represents an interface.
7408 The <code>jboolean</code> result is
7409 <code>JNI_TRUE</code> if the "class" is actually an interface,
7410 <code>JNI_FALSE</code> otherwise.
7411 </description>
7412 <origin>jvmdi</origin>
7413 <capabilities>
7414 </capabilities>
7415 <parameters>
7416 <param id="klass">
7417 <jclass/>
7418 <description>
7419 The class to query.
7420 </description>
7421 </param>
7422 <param id="is_interface_ptr">
7423 <outptr><jboolean/></outptr>
7424 <description>
7425 On return, points to the boolean result of this function.
7426
7427 </description>
7428 </param>
7429 </parameters>
7430 <errors>
7431 </errors>
7432 </function>
7433
7434 <function id="IsArrayClass" phase="start" num="56">
7435 <synopsis>Is Array Class</synopsis>
7436 <description>
7437 Determines whether a class object reference represents an array.
7438 The <code>jboolean</code> result is
7439 <code>JNI_TRUE</code> if the class is an array,
7440 <code>JNI_FALSE</code> otherwise.
7441 </description>
7442 <origin>jvmdi</origin>
7443 <capabilities>
7444 </capabilities>
7445 <parameters>
7446 <param id="klass">
7447 <jclass/>
7448 <description>
7449 The class to query.
7450 </description>
7451 </param>
7452 <param id="is_array_class_ptr">
7453 <outptr><jboolean/></outptr>
7454 <description>
7455 On return, points to the boolean result of this function.
7456
7457 </description>
7458 </param>
7459 </parameters>
7460 <errors>
7461 </errors>
7462 </function>
7463
7464 <function id="IsModifiableClass" jkernel="yes" phase="start" num="45" since="1.1">
7465 <synopsis>Is Modifiable Class</synopsis>
7466 <description>
7467 Determines whether a class is modifiable.
7468 If a class is modifiable (<paramlink id="is_modifiable_class_ptr"/>
7469 returns <code>JNI_TRUE</code>) the class can be
7470 redefined with <functionlink id="RedefineClasses"/> (assuming
7471 the agent possesses the
7472 <fieldlink id="can_redefine_classes" struct="jvmtiCapabilities"/>
7473 capability) or
7474 retransformed with <functionlink id="RetransformClasses"/> (assuming
7475 the agent possesses the
7476 <fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/>
7477 capability).
7478 If a class is not modifiable (<paramlink id="is_modifiable_class_ptr"/>
7479 returns <code>JNI_FALSE</code>) the class can be neither
7480 redefined nor retransformed.
7481 <p/>
7482 Primitive classes (for example, <code>java.lang.Integer.TYPE</code>),
7483 array classes, and some implementation defined classes are never modifiable.
7484 <p/>
7485 </description>
7486 <origin>new</origin>
7487 <capabilities>
7488 <capability id="can_redefine_any_class">
7489 If possessed then all classes (except primitive, array, and some implementation defined
7490 classes) are modifiable with <functionlink id="RedefineClasses"/>.
7491 </capability>
7492 <capability id="can_retransform_any_class">
7493 If possessed then all classes (except primitive, array, and some implementation defined
7494 classes) are modifiable with <functionlink id="RetransformClasses"/>.
7495 </capability>
7496 <capability id="can_redefine_classes">
7497 No effect on the result of the function.
7498 But must additionally be possessed to modify the class with
7499 <functionlink id="RedefineClasses"/>.
7500 </capability>
7501 <capability id="can_retransform_classes">
7502 No effect on the result of the function.
7503 But must additionally be possessed to modify the class with
7504 <functionlink id="RetransformClasses"/>.
7505 </capability>
7506 </capabilities>
7507 <parameters>
7508 <param id="klass">
7509 <jclass/>
7510 <description>
7511 The class to query.
7512 </description>
7513 </param>
7514 <param id="is_modifiable_class_ptr">
7515 <outptr><jboolean/></outptr>
7516 <description>
7517 On return, points to the boolean result of this function.
7518 </description>
7519 </param>
7520 </parameters>
7521 <errors>
7522 </errors>
7523 </function>
7524
7525 <function id="GetClassLoader" phase="start" num="57">
7526 <synopsis>Get Class Loader</synopsis>
7527 <description>
7528 For the class indicated by <code>klass</code>, return via
7529 <code>classloader_ptr</code> a reference to the class loader for the
7530 class.
7531 </description>
7532 <origin>jvmdi</origin>
7533 <capabilities>
7534 </capabilities>
7535 <parameters>
7536 <param id="klass">
7537 <jclass/>
7538 <description>
7539 The class to query.
7540 </description>
7541 </param>
7542 <param id="classloader_ptr">
7543 <outptr><jobject/></outptr>
7544 <description>
7545 On return, points to the class loader that loaded
7546 this class.
7547 If the class was not created by a class loader
7548 or if the class loader is the bootstrap class loader,
7549 points to <code>NULL</code>.
7550 </description>
7551 </param>
7552 </parameters>
7553 <errors>
7554 </errors>
7555
7556 </function>
7557
7558 <function id="GetSourceDebugExtension" phase="start" num="90">
7559 <synopsis>Get Source Debug Extension</synopsis>
7560 <description>
7561 For the class indicated by <code>klass</code>, return the debug
7562 extension via <code>source_debug_extension_ptr</code>.
7563 The returned string
7564 contains exactly the debug extension information present in the
7565 class file of <code>klass</code>.
7566 </description>
7567 <origin>jvmdi</origin>
7568 <capabilities>
7569 <required id="can_get_source_debug_extension"></required>
7570 </capabilities>
7571 <parameters>
7572 <param id="klass">
7573 <jclass/>
7574 <description>
7575 The class to query.
7576 </description>
7577 </param>
7578 <param id="source_debug_extension_ptr">
7579 <allocbuf><char/></allocbuf>
7580 <description>
7581 On return, points to the class's debug extension, encoded as a
7582 <internallink id="mUTF">modified UTF-8</internallink> string.
7583 </description>
7584 </param>
7585 </parameters>
7586 <errors>
7587 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7588 Class information does not include a debug extension.
7589 </error>
7590 </errors>
7591 </function>
7592
7593 <function id="RetransformClasses" jkernel="yes" num="152" since="1.1">
7594 <synopsis>Retransform Classes</synopsis>
7595 <description>
7596 This function facilitates the
7597 <internallink id="bci">bytecode instrumentation</internallink>
7598 of already loaded classes.
7599 To replace the class definition without reference to the existing
7600 bytecodes, as one might do when recompiling from source for
7601 fix-and-continue debugging, <functionlink id="RedefineClasses"/>
7602 function should be used instead.
7603 <p/>
7604 When classes are initially loaded or when they are
7605 <functionlink id="RedefineClasses">redefined</functionlink>,
7606 the initial class file bytes can be transformed with the
7607 <eventlink id="ClassFileLoadHook"/> event.
7608 This function reruns the transformation process
7609 (whether or not a transformation has previously occurred).
7610 This retransformation follows these steps:
7611 <ul>
7612 <li>starting from the initial class file bytes
7613 </li>
7614 <li>for each <fieldlink id="can_retransform_classes"
7615 struct="jvmtiCapabilities">retransformation
7616 incapable</fieldlink>
7617 agent which received a
7618 <code>ClassFileLoadHook</code> event during the previous
7619 load or redefine, the bytes it returned
7620 (via the <code>new_class_data</code> parameter)
7621 are reused as the output of the transformation;
7622 note that this is equivalent to reapplying
7623 the previous transformation, unaltered. except that
7624 the <code>ClassFileLoadHook</code> event
7625 is <b>not</b> sent to these agents
7626 </li>
7627 <li>for each <fieldlink id="can_retransform_classes"
7628 struct="jvmtiCapabilities">retransformation
7629 capable</fieldlink>
7630 agent, the <code>ClassFileLoadHook</code> event is sent,
7631 allowing a new transformation to be applied
7632 </li>
7633 <li>the transformed class file bytes are installed as the new
7634 definition of the class
7635 </li>
7636 </ul>
7637 See the <eventlink id="ClassFileLoadHook"/> event for more details.
7638 <p/>
7639 The initial class file bytes represent the bytes passed to
7640 <code>ClassLoader.defineClass</code>
7641 or <code>RedefineClasses</code> (before any transformations
7642 were applied), however they may not exactly match them.
7643 The constant pool may differ in ways described in
7644 <functionlink id="GetConstantPool"/>.
7645 Constant pool indices in the bytecodes of methods will correspond.
7646 Some attributes may not be present.
7647 Where order is not meaningful, for example the order of methods,
7648 order may not be preserved.
7649 <p/>
7650 Retransformation can cause new versions of methods to be installed.
7651 Old method versions may become
7652 <internallink id="obsoleteMethods">obsolete</internallink>
7653 The new method version will be used on new invokes.
7654 If a method has active stack frames, those active frames continue to
7655 run the bytecodes of the original method version.
7656 <p/>
7657 This function does not cause any initialization except that which
7658 would occur under the customary JVM semantics.
7659 In other words, retransforming a class does not cause its initializers to be
7660 run. The values of static fields will remain as they were
7661 prior to the call.
7662 <p/>
7663 Threads need not be suspended.
7664 <p/>
7665 All breakpoints in the class are cleared.
7666 <p/>
7667 All attributes are updated.
7668 <p/>
7669 Instances of the retransformed class are not affected -- fields retain their
7670 previous values.
7671 <functionlink id="GetTag">Tags</functionlink> on the instances are
7672 also unaffected.
7673 <p/>
7674 In response to this call, no events other than the
7675 <eventlink id="ClassFileLoadHook"/> event
7676 will be sent.
7677 <p/>
7678 The retransformation may change method bodies, the constant pool and attributes
7679 (unless explicitly prohibited).
7680 The retransformation must not add, remove or rename fields or methods, change the
7681 signatures of methods, change modifiers, or change inheritance.
7682 The retransformation must not change the <code>NestHost</code>,
7683 <code>NestMembers</code>, or <code>Record</code> attributes.
7684 These restrictions may be lifted in future versions.
7685 See the error return description below for information on error codes
7686 returned if an unsupported retransformation is attempted.
7687 The class file bytes are not verified or installed until they have passed
7688 through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the
7689 returned error code reflects the result of the transformations.
7690 If any error code is returned other than <code>JVMTI_ERROR_NONE</code>,
7691 none of the classes to be retransformed will have a new definition installed.
7692 When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>)
7693 all of the classes to be retransformed will have their new definitions installed.
7694 </description>
7695 <origin>new</origin>
7696 <capabilities>
7697 <required id="can_retransform_classes"></required>
7698 <capability id="can_retransform_any_class"></capability>
7699 </capabilities>
7700 <parameters>
7701 <param id="class_count">
7702 <jint min="0"/>
7703 <description>
7704 The number of classes to be retransformed.
7705 </description>
7706 </param>
7707 <param id="classes">
7708 <inbuf incount="class_count"><jclass/></inbuf>
7709 <description>
7710 The array of classes to be retransformed.
7711 </description>
7712 </param>
7713 </parameters>
7714 <errors>
7715 <error id="JVMTI_ERROR_UNMODIFIABLE_CLASS">
7716 One of the <paramlink id="classes"/> cannot be modified.
7717 See <functionlink id="IsModifiableClass"/>.
7718 </error>
7719 <error id="JVMTI_ERROR_INVALID_CLASS">
7720 One of the <paramlink id="classes"/> is not a valid class.
7721 </error>
7722 <error id="JVMTI_ERROR_UNSUPPORTED_VERSION">
7723 A retransformed class file has a version number not supported by this VM.
7724 </error>
7725 <error id="JVMTI_ERROR_INVALID_CLASS_FORMAT">
7726 A retransformed class file is malformed (The VM would return a <code>ClassFormatError</code>).
7727 </error>
7728 <error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION">
7729 The retransformed class file definitions would lead to a circular definition
7730 (the VM would return a <code>ClassCircularityError</code>).
7731 </error>
7732 <error id="JVMTI_ERROR_FAILS_VERIFICATION">
7733 The retransformed class file bytes fail verification.
7734 </error>
7735 <error id="JVMTI_ERROR_NAMES_DONT_MATCH">
7736 The class name defined in a retransformed class file is
7737 different from the name in the old class object.
7738 </error>
7739 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED">
7740 A retransformed class file would require adding a method.
7741 </error>
7742 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED">
7743 A retransformed class file changes a field.
7744 </error>
7745 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED">
7746 A direct superclass is different for a retransformed class file,
7747 or the set of directly implemented
7748 interfaces is different.
7749 </error>
7750 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED">
7751 A retransformed class file does not declare a method
7752 declared in the old class version.
7753 </error>
7754 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_ATTRIBUTE_CHANGED">
7755 A retransformed class file has unsupported differences in class attributes.
7756 </error>
7757 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED">
7758 A retransformed class file has different class modifiers.
7759 </error>
7760 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED">
7761 A method in the retransformed class file has different modifiers
7762 than its counterpart in the old class version.
7763 </error>
7764 </errors>
7765 </function>
7766
7767 <function id="RedefineClasses" jkernel="yes" num="87">
7768 <synopsis>Redefine Classes</synopsis>
7769 <typedef id="jvmtiClassDefinition" label="Class redefinition description">
7770 <field id="klass">
7771 <jclass/>
7772 <description>
7773 Class object for this class
7774 </description>
7775 </field>
7776 <field id="class_byte_count">
7777 <jint/>
7778 <description>
7779 Number of bytes defining class (below)
7780 </description>
7781 </field>
7782 <field id="class_bytes">
7783 <inbuf incount="class_byte_count"><uchar/></inbuf>
7784 <description>
7785 Bytes defining class (in <vmspec chapter="4"/>)
7786 </description>
7787 </field>
7788 </typedef>
7789 <description>
7790 All classes given are redefined according to the definitions
7791 supplied.
7792 This function is used to replace the definition of a class
7793 with a new definition, as might be needed in fix-and-continue
7794 debugging.
7795 Where the existing class file bytes are to be transformed, for
7796 example in
7797 <internallink id="bci">bytecode instrumentation</internallink>,
7798 <functionlink id="RetransformClasses"/> should be used.
7799 <p/>
7800 Redefinition can cause new versions of methods to be installed.
7801 Old method versions may become
7802 <internallink id="obsoleteMethods">obsolete</internallink>
7803 The new method version will be used on new invokes.
7804 If a method has active stack frames, those active frames continue to
7805 run the bytecodes of the original method version.
7806 If resetting of stack frames is desired, use
7807 <functionlink id="PopFrame"></functionlink>
7808 to pop frames with obsolete method versions.
7809 <p/>
7810 This function does not cause any initialization except that which
7811 would occur under the customary JVM semantics.
7812 In other words, redefining a class does not cause its initializers to be
7813 run. The values of static fields will remain as they were
7814 prior to the call.
7815 <p/>
7816 Threads need not be suspended.
7817 <p/>
7818 All breakpoints in the class are cleared.
7819 <p/>
7820 All attributes are updated.
7821 <p/>
7822 Instances of the redefined class are not affected -- fields retain their
7823 previous values.
7824 <functionlink id="GetTag">Tags</functionlink> on the instances are
7825 also unaffected.
7826 <p/>
7827 In response to this call, the <jvmti/> event
7828 <eventlink id="ClassFileLoadHook">Class File Load Hook</eventlink>
7829 will be sent (if enabled), but no other <jvmti/> events will be sent.
7830 <p/>
7831 The redefinition may change method bodies, the constant pool and attributes
7832 (unless explicitly prohibited).
7833 The redefinition must not add, remove or rename fields or methods, change the
7834 signatures of methods, change modifiers, or change inheritance.
7835 The redefinition must not change the <code>NestHost</code>,
7836 <code>NestMembers</code>, or <code>Record</code> attributes.
7837 These restrictions may be lifted in future versions.
7838 See the error return description below for information on error codes
7839 returned if an unsupported redefinition is attempted.
7840 The class file bytes are not verified or installed until they have passed
7841 through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the
7842 returned error code reflects the result of the transformations applied
7843 to the bytes passed into <paramlink id="class_definitions"/>.
7844 If any error code is returned other than <code>JVMTI_ERROR_NONE</code>,
7845 none of the classes to be redefined will have a new definition installed.
7846 When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>)
7847 all of the classes to be redefined will have their new definitions installed.
7848 </description>
7849 <origin>jvmdi</origin>
7850 <capabilities>
7851 <required id="can_redefine_classes"></required>
7852 <capability id="can_redefine_any_class"></capability>
7853 </capabilities>
7854 <parameters>
7855 <param id="class_count">
7856 <jint min="0"/>
7857 <description>
7858 The number of classes specified in <code>class_definitions</code>
7859 </description>
7860 </param>
7861 <param id="class_definitions">
7862 <inbuf incount="class_count"><struct>jvmtiClassDefinition</struct></inbuf>
7863 <description>
7864 The array of new class definitions
7865 </description>
7866 </param>
7867 </parameters>
7868 <errors>
7869 <error id="JVMTI_ERROR_NULL_POINTER">
7870 One of <code>class_bytes</code> is <code>NULL</code>.
7871 </error>
7872 <error id="JVMTI_ERROR_UNMODIFIABLE_CLASS">
7873 An element of <code>class_definitions</code> cannot be modified.
7874 See <functionlink id="IsModifiableClass"/>.
7875 </error>
7876 <error id="JVMTI_ERROR_INVALID_CLASS">
7877 An element of <code>class_definitions</code> is not a valid class.
7878 </error>
7879 <error id="JVMTI_ERROR_UNSUPPORTED_VERSION">
7880 A new class file has a version number not supported by this VM.
7881 </error>
7882 <error id="JVMTI_ERROR_INVALID_CLASS_FORMAT">
7883 A new class file is malformed (The VM would return a <code>ClassFormatError</code>).
7884 </error>
7885 <error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION">
7886 The new class file definitions would lead to a circular definition
7887 (the VM would return a <code>ClassCircularityError</code>).
7888 </error>
7889 <error id="JVMTI_ERROR_FAILS_VERIFICATION">
7890 The class bytes fail verification.
7891 </error>
7892 <error id="JVMTI_ERROR_NAMES_DONT_MATCH">
7893 The class name defined in a new class file is
7894 different from the name in the old class object.
7895 </error>
7896 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED">
7897 A new class file would require adding a method.
7898 </error>
7899 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED">
7900 A new class version changes a field.
7901 </error>
7902 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED">
7903 A direct superclass is different for a new class
7904 version, or the set of directly implemented
7905 interfaces is different.
7906 </error>
7907 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED">
7908 A new class version does not declare a method
7909 declared in the old class version.
7910 </error>
7911 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_ATTRIBUTE_CHANGED">
7912 A new class version has unsupported differences in class attributes.
7913 </error>
7914 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED">
7915 A new class version has different modifiers.
7916 </error>
7917 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED">
7918 A method in the new class version has different modifiers
7919 than its counterpart in the old class version.
7920 </error>
7921 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE">
7922 A module cannot be modified.
7923 See <functionlink id="IsModifiableModule"/>.
7924 </error>
7925 </errors>
7926 </function>
7927
7928 </category>
7929
7930 <category id="object" label="Object">
7931
7932 <function id="GetObjectSize" jkernel="yes" phase="start" num="154">
7933 <synopsis>Get Object Size</synopsis>
7934 <description>
7935 For the object indicated by <code>object</code>,
7936 return via <code>size_ptr</code> the size of the object.
7937 This size is an implementation-specific approximation of
7938 the amount of storage consumed by this object.
7939 It may include some or all of the object's overhead, and thus
7940 is useful for comparison within an implementation but not
7941 between implementations.
7942 The estimate may change during a single invocation of the JVM.
7943 </description>
7944 <origin>new</origin>
7945 <capabilities>
7946 </capabilities>
7947 <parameters>
7948 <param id="object">
7949 <jobject/>
7950 <description>
7951 The object to query.
7952 </description>
7953 </param>
7954 <param id="size_ptr">
7955 <outptr><jlong/></outptr>
7956 <description>
7957 On return, points to the object's size in bytes.
7958 </description>
7959 </param>
7960 </parameters>
7961 <errors>
7962 </errors>
7963 </function>
7964
7965 <function id="GetObjectHashCode" phase="start" num="58">
7966 <synopsis>Get Object Hash Code</synopsis>
7967 <description>
7968 For the object indicated by <code>object</code>,
7969 return via <code>hash_code_ptr</code> a hash code.
7970 This hash code could be used to maintain a hash table of object references,
7971 however, on some implementations this can cause significant performance
7972 impacts--in most cases
7973 <internallink id="Heap">tags</internallink>
7974 will be a more efficient means of associating information with objects.
7975 This function guarantees
7976 the same hash code value for a particular object throughout its life
7977 </description>
7978 <origin>jvmdi</origin>
7979 <capabilities>
7980 </capabilities>
7981 <parameters>
7982 <param id="object">
7983 <jobject/>
7984 <description>
7985 The object to query.
7986 </description>
7987 </param>
7988 <param id="hash_code_ptr">
7989 <outptr><jint/></outptr>
7990 <description>
7991 On return, points to the object's hash code.
7992 </description>
7993 </param>
7994 </parameters>
7995 <errors>
7996 </errors>
7997 </function>
7998
7999 <function id="GetObjectMonitorUsage" num="59">
8000 <synopsis>Get Object Monitor Usage</synopsis>
8001 <typedef id="jvmtiMonitorUsage" label="Object monitor usage information">
8002 <field id="owner">
8003 <jthread/>
8004 <description>
8005 The thread owning this monitor, or <code>NULL</code> if unused
8006 </description>
8007 </field>
8008 <field id="entry_count">
8009 <jint/>
8010 <description>
8011 The number of times the owning thread has entered the monitor
8012 </description>
8013 </field>
8014 <field id="waiter_count">
8015 <jint/>
8016 <description>
8017 The number of threads waiting to own this monitor
8018 </description>
8019 </field>
8020 <field id="waiters">
8021 <allocfieldbuf><jthread/></allocfieldbuf>
8022 <description>
8023 The <code>waiter_count</code> waiting threads
8024 </description>
8025 </field>
8026 <field id="notify_waiter_count">
8027 <jint/>
8028 <description>
8029 The number of threads waiting to be notified by this monitor
8030 </description>
8031 </field>
8032 <field id="notify_waiters">
8033 <allocfieldbuf><jthread/></allocfieldbuf>
8034 <description>
8035 The <code>notify_waiter_count</code> threads waiting to be notified
8036 </description>
8037 </field>
8038 </typedef>
8039 <description>
8040 Get information about the object's monitor.
8041 The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure
8042 are filled in with information about usage of the monitor.
8043 <todo>
8044 Decide and then clarify suspend requirements.
8045 </todo>
8046 </description>
8047 <origin>jvmdi</origin>
8048 <capabilities>
8049 <required id="can_get_monitor_info"></required>
8050 </capabilities>
8051 <parameters>
8052 <param id="object">
8053 <jobject/>
8054 <description>
8055 The object to query.
8056 </description>
8057 </param>
8058 <param id="info_ptr">
8059 <outptr><struct>jvmtiMonitorUsage</struct></outptr>
8060 <description>
8061 On return, filled with monitor information for the
8062 specified object.
8063 </description>
8064 </param>
8065 </parameters>
8066 <errors>
8067 </errors>
8068 </function>
8069
8070 <elide>
8071 <function id="GetObjectMonitors" num="116">
8072 <synopsis>Get Object Monitors</synopsis>
8073 <description>
8074 Return the list of object monitors.
8075 <p/>
8076 Note: details about each monitor can be examined with
8077 <functionlink id="GetObjectMonitorUsage"></functionlink>.
8078 </description>
8079 <origin>new</origin>
8080 <capabilities>
8081 <required id="can_get_monitor_info"></required>
8082 </capabilities>
8083 <parameters>
8084 <param id="monitorCnt">
8085 <outptr><jint/></outptr>
8086 <description>
8087 On return, pointer to the number
8088 of monitors returned in <code>monitors_ptr</code>.
8089 </description>
8090 </param>
8091 <param id="monitors_ptr">
8092 <allocbuf outcount="monitorCnt"><jobject/></allocbuf>
8093 <description>
8094 On return, pointer to the monitor list.
8095 </description>
8096 </param>
8097 </parameters>
8098 <errors>
8099 </errors>
8100 </function>
8101 </elide>
8102
8103 </category>
8104
8105 <category id="fieldCategory" label="Field">
8106
8107 <intro>
8108 </intro>
8109
8110 <function id="GetFieldName" phase="start" num="60">
8111 <synopsis>Get Field Name (and Signature)</synopsis>
8112 <description>
8113 For the field indicated by <paramlink id="klass"/> and <paramlink id="field"/>,
8114 return the field name via <paramlink id="name_ptr"/> and field signature via
8115 <paramlink id="signature_ptr"/>.
8116 <p/>
8117 Field signatures are defined in the
8118 <externallink id="jni/index.html">JNI Specification</externallink>
8119 and are referred to as <code>field descriptors</code> in
8120 <vmspec chapter="4.3.2"/>.
8121 </description>
8122 <origin>jvmdiClone</origin>
8123 <capabilities>
8124 </capabilities>
8125 <parameters>
8126 <param id="klass">
8127 <jclass field="field"/>
8128 <description>
8129 The class of the field to query.
8130 </description>
8131 </param>
8132 <param id="field">
8133 <jfieldID class="klass"/>
8134 <description>
8135 The field to query.
8136 </description>
8137 </param>
8138 <param id="name_ptr">
8139 <allocbuf>
8140 <char/>
8141 <nullok>the name is not returned</nullok>
8142 </allocbuf>
8143 <description>
8144 On return, points to the field name, encoded as a
8145 <internallink id="mUTF">modified UTF-8</internallink> string.
8146 </description>
8147 </param>
8148 <param id="signature_ptr">
8149 <allocbuf>
8150 <char/>
8151 <nullok>the signature is not returned</nullok>
8152 </allocbuf>
8153 <description>
8154 On return, points to the field signature, encoded as a
8155 <internallink id="mUTF">modified UTF-8</internallink> string.
8156 </description>
8157 </param>
8158 <param id="generic_ptr">
8159 <allocbuf>
8160 <char/>
8161 <nullok>the generic signature is not returned</nullok>
8162 </allocbuf>
8163 <description>
8164 On return, points to the generic signature of the field, encoded as a
8165 <internallink id="mUTF">modified UTF-8</internallink> string.
8166 If there is no generic signature attribute for the field, then,
8167 on return, points to <code>NULL</code>.
8168 </description>
8169 </param>
8170 </parameters>
8171 <errors>
8172 </errors>
8173 </function>
8174
8175 <function id="GetFieldDeclaringClass" phase="start" num="61">
8176 <synopsis>Get Field Declaring Class</synopsis>
8177 <description>
8178 For the field indicated by <code>klass</code> and <code>field</code>
8179 return the class that defined it via <code>declaring_class_ptr</code>.
8180 The declaring class will either be <code>klass</code>, a superclass, or
8181 an implemented interface.
8182 </description>
8183 <origin>jvmdi</origin>
8184 <capabilities>
8185 </capabilities>
8186 <parameters>
8187 <param id="klass">
8188 <jclass field="field"/>
8189 <description>
8190 The class to query.
8191 </description>
8192 </param>
8193 <param id="field">
8194 <jfieldID class="klass"/>
8195 <description>
8196 The field to query.
8197 </description>
8198 </param>
8199 <param id="declaring_class_ptr">
8200 <outptr><jclass/></outptr>
8201 <description>
8202 On return, points to the declaring class
8203 </description>
8204 </param>
8205 </parameters>
8206 <errors>
8207 </errors>
8208 </function>
8209
8210 <function id="GetFieldModifiers" phase="start" num="62">
8211 <synopsis>Get Field Modifiers</synopsis>
8212 <description>
8213 For the field indicated by <code>klass</code> and <code>field</code>
8214 return the access flags via <code>modifiers_ptr</code>.
8215 Access flags are defined in <vmspec chapter="4"/>.
8216 </description>
8217 <origin>jvmdi</origin>
8218 <capabilities>
8219 </capabilities>
8220 <parameters>
8221 <param id="klass">
8222 <jclass field="field"/>
8223 <description>
8224 The class to query.
8225 </description>
8226 </param>
8227 <param id="field">
8228 <jfieldID class="klass"/>
8229 <description>
8230 The field to query.
8231 </description>
8232 </param>
8233 <param id="modifiers_ptr">
8234 <outptr><jint/></outptr>
8235 <description>
8236 On return, points to the access flags.
8237 </description>
8238 </param>
8239 </parameters>
8240 <errors>
8241 </errors>
8242 </function>
8243
8244 <function id="IsFieldSynthetic" phase="start" num="63">
8245 <synopsis>Is Field Synthetic</synopsis>
8246 <description>
8247 For the field indicated by <code>klass</code> and <code>field</code>, return a
8248 value indicating whether the field is synthetic via <code>is_synthetic_ptr</code>.
8249 Synthetic fields are generated by the compiler but not present in the
8250 original source code.
8251 </description>
8252 <origin>jvmdi</origin>
8253 <capabilities>
8254 <required id="can_get_synthetic_attribute"></required>
8255 </capabilities>
8256 <parameters>
8257 <param id="klass">
8258 <jclass field="field"/>
8259 <description>
8260 The class of the field to query.
8261 </description>
8262 </param>
8263 <param id="field">
8264 <jfieldID class="klass"/>
8265 <description>
8266 The field to query.
8267 </description>
8268 </param>
8269 <param id="is_synthetic_ptr">
8270 <outptr><jboolean/></outptr>
8271 <description>
8272 On return, points to the boolean result of this function.
8273 </description>
8274 </param>
8275 </parameters>
8276 <errors>
8277 </errors>
8278 </function>
8279
8280 </category>
8281
8282 <category id="method" label="Method">
8283
8284 <intro>
8285 These functions provide information about a method (represented as a
8286 <typelink id="jmethodID"/>) and set how methods are processed.
8287 </intro>
8288
8289 <intro id="obsoleteMethods" label="Obsolete Methods">
8290 The functions <functionlink id="RetransformClasses"/> and
8291 <functionlink id="RedefineClasses"/> can cause new versions
8292 of methods to be installed.
8293 An original version of a method is considered equivalent
8294 to the new version if:
8295 <ul>
8296 <li>their bytecodes are the same except for indices into the
8297 constant pool and </li>
8298 <li>the referenced constants are equal.</li>
8299 </ul>
8300 An original method version which is not equivalent to the
8301 new method version is called obsolete and is assigned a new method ID;
8302 the original method ID now refers to the new method version.
8303 A method ID can be tested for obsolescence with
8304 <functionlink id="IsMethodObsolete"/>.
8305 </intro>
8306
8307 <function id="GetMethodName" phase="start" num="64">
8308 <synopsis>Get Method Name (and Signature)</synopsis>
8309 <description>
8310 For the method indicated by <code>method</code>,
8311 return the method name via <code>name_ptr</code> and method signature via
8312 <code>signature_ptr</code>.
8313 <p/>
8314 Method signatures are defined in the
8315 <externallink id="jni/index.html">JNI Specification</externallink>
8316 and are referred to as <code>method descriptors</code> in
8317 <vmspec chapter="4.3.3"/>.
8318 Note this is different
8319 than method signatures as defined in the <i>Java Language Specification</i>.
8320 </description>
8321 <origin>jvmdiClone</origin>
8322 <capabilities>
8323 </capabilities>
8324 <parameters>
8325 <param id="method">
8326 <jmethodID/>
8327 <description>
8328 The method to query.
8329 </description>
8330 </param>
8331 <param id="name_ptr">
8332 <allocbuf>
8333 <char/>
8334 <nullok>the name is not returned</nullok>
8335 </allocbuf>
8336 <description>
8337 On return, points to the method name, encoded as a
8338 <internallink id="mUTF">modified UTF-8</internallink> string.
8339 </description>
8340 </param>
8341 <param id="signature_ptr">
8342 <allocbuf>
8343 <char/>
8344 <nullok>the signature is not returned</nullok>
8345 </allocbuf>
8346 <description>
8347 On return, points to the method signature, encoded as a
8348 <internallink id="mUTF">modified UTF-8</internallink> string.
8349 </description>
8350 </param>
8351 <param id="generic_ptr">
8352 <allocbuf>
8353 <char/>
8354 <nullok>the generic signature is not returned</nullok>
8355 </allocbuf>
8356 <description>
8357 On return, points to the generic signature of the method, encoded as a
8358 <internallink id="mUTF">modified UTF-8</internallink> string.
8359 If there is no generic signature attribute for the method, then,
8360 on return, points to <code>NULL</code>.
8361 </description>
8362 </param>
8363 </parameters>
8364 <errors>
8365 </errors>
8366 </function>
8367
8368 <function id="GetMethodDeclaringClass" phase="start" num="65">
8369 <synopsis>Get Method Declaring Class</synopsis>
8370 <description>
8371 For the method indicated by <code>method</code>,
8372 return the class that defined it via <code>declaring_class_ptr</code>.
8373 </description>
8374 <origin>jvmdi</origin>
8375 <capabilities>
8376 </capabilities>
8377 <parameters>
8378 <param id="klass">
8379 <jclass method="method"/>
8380 <description>
8381 The class to query.
8382 </description>
8383 </param>
8384 <param id="method">
8385 <jmethodID class="klass"/>
8386 <description>
8387 The method to query.
8388 </description>
8389 </param>
8390 <param id="declaring_class_ptr">
8391 <outptr><jclass/></outptr>
8392 <description>
8393 On return, points to the declaring class
8394 </description>
8395 </param>
8396 </parameters>
8397 <errors>
8398 </errors>
8399 </function>
8400
8401 <function id="GetMethodModifiers" phase="start" num="66">
8402 <synopsis>Get Method Modifiers</synopsis>
8403 <description>
8404 For the method indicated by <code>method</code>,
8405 return the access flags via <code>modifiers_ptr</code>.
8406 Access flags are defined in <vmspec chapter="4"/>.
8407 </description>
8408 <origin>jvmdi</origin>
8409 <capabilities>
8410 </capabilities>
8411 <parameters>
8412 <param id="klass">
8413 <jclass method="method"/>
8414 <description>
8415 The class to query.
8416 </description>
8417 </param>
8418 <param id="method">
8419 <jmethodID class="klass"/>
8420 <description>
8421 The method to query.
8422 </description>
8423 </param>
8424 <param id="modifiers_ptr">
8425 <outptr><jint/></outptr>
8426 <description>
8427 On return, points to the access flags.
8428 </description>
8429 </param>
8430 </parameters>
8431 <errors>
8432 </errors>
8433 </function>
8434
8435 <function id="GetMaxLocals" phase="start" num="68">
8436 <synopsis>Get Max Locals</synopsis>
8437 <description>
8438 For the method indicated by <code>method</code>,
8439 return the number of local variable slots used by the method,
8440 including the local variables used to pass parameters to the
8441 method on its invocation.
8442 <p/>
8443 See <code>max_locals</code> in <vmspec chapter="4.7.3"/>.
8444 </description>
8445 <origin>jvmdi</origin>
8446 <capabilities>
8447 </capabilities>
8448 <parameters>
8449 <param id="klass">
8450 <jclass method="method"/>
8451 <description>
8452 The class to query.
8453 </description>
8454 </param>
8455 <param id="method">
8456 <jmethodID class="klass" native="error"/>
8457 <description>
8458 The method to query.
8459 </description>
8460 </param>
8461 <param id="max_ptr">
8462 <outptr><jint/></outptr>
8463 <description>
8464 On return, points to the maximum number of local slots
8465 </description>
8466 </param>
8467 </parameters>
8468 <errors>
8469 </errors>
8470 </function>
8471
8472 <function id="GetArgumentsSize" phase="start" num="69">
8473 <synopsis>Get Arguments Size</synopsis>
8474 <description>
8475 For the method indicated by <code>method</code>,
8476 return via <code>max_ptr</code> the number of local variable slots used
8477 by the method's arguments.
8478 Note that two-word arguments use two slots.
8479 </description>
8480 <origin>jvmdi</origin>
8481 <capabilities>
8482 </capabilities>
8483 <parameters>
8484 <param id="klass">
8485 <jclass method="method"/>
8486 <description>
8487 The class to query.
8488 </description>
8489 </param>
8490 <param id="method">
8491 <jmethodID class="klass" native="error"/>
8492 <description>
8493 The method to query.
8494 </description>
8495 </param>
8496 <param id="size_ptr">
8497 <outptr><jint/></outptr>
8498 <description>
8499 On return, points to the number of argument slots
8500 </description>
8501 </param>
8502 </parameters>
8503 <errors>
8504 </errors>
8505 </function>
8506
8507 <function id="GetLineNumberTable" phase="start" num="70">
8508 <synopsis>Get Line Number Table</synopsis>
8509 <typedef id="jvmtiLineNumberEntry" label="Line number table entry">
8510 <field id="start_location">
8511 <jlocation/>
8512 <description>
8513 the <datalink id="jlocation"></datalink> where the line begins
8514 </description>
8515 </field>
8516 <field id="line_number">
8517 <jint/>
8518 <description>
8519 the line number
8520 </description>
8521 </field>
8522 </typedef>
8523 <description>
8524 For the method indicated by <code>method</code>,
8525 return a table of source line number entries. The size of the table is
8526 returned via <code>entry_count_ptr</code> and the table itself is
8527 returned via <code>table_ptr</code>.
8528 </description>
8529 <origin>jvmdi</origin>
8530 <capabilities>
8531 <required id="can_get_line_numbers"></required>
8532 </capabilities>
8533 <parameters>
8534 <param id="klass">
8535 <jclass method="method"/>
8536 <description>
8537 The class to query.
8538 </description>
8539 </param>
8540 <param id="method">
8541 <jmethodID class="klass" native="error"/>
8542 <description>
8543 The method to query.
8544 </description>
8545 </param>
8546 <param id="entry_count_ptr">
8547 <outptr><jint/></outptr>
8548 <description>
8549 On return, points to the number of entries in the table
8550 </description>
8551 </param>
8552 <param id="table_ptr">
8553 <allocbuf outcount="entry_count_ptr"><struct>jvmtiLineNumberEntry</struct></allocbuf>
8554 <description>
8555 On return, points to the line number table pointer.
8556 </description>
8557 </param>
8558 </parameters>
8559 <errors>
8560 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8561 Class information does not include line numbers.
8562 </error>
8563 </errors>
8564 </function>
8565
8566 <function id="GetMethodLocation" phase="start" num="71">
8567 <synopsis>Get Method Location</synopsis>
8568 <description>
8569 For the method indicated by <code>method</code>,
8570 return the beginning and ending addresses through
8571 <code>start_location_ptr</code> and <code>end_location_ptr</code>. In a
8572 conventional bytecode indexing scheme,
8573 <code>start_location_ptr</code> will always point to zero
8574 and <code>end_location_ptr</code>
8575 will always point to the bytecode count minus one.
8576 </description>
8577 <origin>jvmdi</origin>
8578 <capabilities>
8579 </capabilities>
8580 <parameters>
8581 <param id="klass">
8582 <jclass method="method"/>
8583 <description>
8584 The class to query.
8585 </description>
8586 </param>
8587 <param id="method">
8588 <jmethodID class="klass" native="error"/>
8589 <description>
8590 The method to query.
8591 </description>
8592 </param>
8593 <param id="start_location_ptr">
8594 <outptr><jlocation/></outptr>
8595 <description>
8596 On return, points to the first location, or
8597 <code>-1</code> if location information is not available.
8598 If the information is available and
8599 <functionlink id="GetJLocationFormat"></functionlink>
8600 returns <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>
8601 then this will always be zero.
8602 </description>
8603 </param>
8604 <param id="end_location_ptr">
8605 <outptr><jlocation/></outptr>
8606 <description>
8607 On return, points to the last location,
8608 or <code>-1</code> if location information is not available.
8609 </description>
8610 </param>
8611 </parameters>
8612 <errors>
8613 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8614 Class information does not include method sizes.
8615 </error>
8616 </errors>
8617 </function>
8618
8619 <function id="GetLocalVariableTable" num="72">
8620 <synopsis>Get Local Variable Table</synopsis>
8621 <typedef id="jvmtiLocalVariableEntry" label="Local variable table entry">
8622 <field id="start_location">
8623 <jlocation/>
8624 <description>
8625 The code array index where the local variable is first valid
8626 (that is, where it must have a value).
8627 </description>
8628 </field>
8629 <field id="length">
8630 <jint/>
8631 <description>
8632 The length of the valid section for this local variable.
8633 The last code array index where the local variable is valid
8634 is <code>start_location + length</code>.
8635 </description>
8636 </field>
8637 <field id="name">
8638 <allocfieldbuf><char/></allocfieldbuf>
8639 <description>
8640 The local variable name, encoded as a
8641 <internallink id="mUTF">modified UTF-8</internallink> string.
8642 </description>
8643 </field>
8644 <field id="signature">
8645 <allocfieldbuf><char/></allocfieldbuf>
8646 <description>
8647 The local variable's type signature, encoded as a
8648 <internallink id="mUTF">modified UTF-8</internallink> string.
8649 The signature format is the same as that defined in
8650 <vmspec chapter="4.3.2"/>.
8651 </description>
8652 </field>
8653 <field id="generic_signature">
8654 <allocfieldbuf><char/></allocfieldbuf>
8655 <description>
8656 The local variable's generic signature, encoded as a
8657 <internallink id="mUTF">modified UTF-8</internallink> string.
8658 The value of this field will be <code>NULL</code> for any local
8659 variable which does not have a generic type.
8660 </description>
8661 </field>
8662 <field id="slot">
8663 <jint/>
8664 <description>
8665 The local variable's slot. See <internallink id="local">Local Variables</internallink>.
8666 </description>
8667 </field>
8668 </typedef>
8669 <description>
8670 Return local variable information.
8671 </description>
8672 <origin>jvmdiClone</origin>
8673 <capabilities>
8674 <required id="can_access_local_variables"></required>
8675 </capabilities>
8676 <parameters>
8677 <param id="method">
8678 <jmethodID native="error"/>
8679 <description>
8680 The method to query.
8681 </description>
8682 </param>
8683 <param id="entry_count_ptr">
8684 <outptr><jint/></outptr>
8685 <description>
8686 On return, points to the number of entries in the table
8687 </description>
8688 </param>
8689 <param id="table_ptr">
8690 <allocbuf outcount="entry_count_ptr"><struct>jvmtiLocalVariableEntry</struct></allocbuf>
8691 <description>
8692 On return, points to an array of local variable table entries.
8693 </description>
8694 </param>
8695 </parameters>
8696 <errors>
8697 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8698 Class information does not include local variable
8699 information.
8700 </error>
8701 </errors>
8702 </function>
8703
8704 <function id="GetBytecodes" phase="start" num="75">
8705 <synopsis>Get Bytecodes</synopsis>
8706 <description>
8707 For the method indicated by <code>method</code>,
8708 return the bytecodes that implement the method. The number of
8709 bytecodes is returned via <code>bytecode_count_ptr</code>. The bytecodes
8710 themselves are returned via <code>bytecodes_ptr</code>.
8711 </description>
8712 <origin>jvmdi</origin>
8713 <capabilities>
8714 <required id="can_get_bytecodes"></required>
8715 </capabilities>
8716 <parameters>
8717 <param id="klass">
8718 <jclass method="method"/>
8719 <description>
8720 The class to query.
8721 </description>
8722 </param>
8723 <param id="method">
8724 <jmethodID class="klass" native="error"/>
8725 <description>
8726 The method to query.
8727 </description>
8728 </param>
8729 <param id="bytecode_count_ptr">
8730 <outptr><jint/></outptr>
8731 <description>
8732 On return, points to the length of the bytecode array
8733 </description>
8734 </param>
8735 <param id="bytecodes_ptr">
8736 <allocbuf outcount="bytecode_count_ptr"><uchar/></allocbuf>
8737 <description>
8738 On return, points to the pointer to the bytecode array
8739 </description>
8740 </param>
8741 </parameters>
8742 <errors>
8743 </errors>
8744 </function>
8745
8746 <function id="IsMethodNative" phase="start" num="76">
8747 <synopsis>Is Method Native</synopsis>
8748 <description>
8749 For the method indicated by <code>method</code>, return a
8750 value indicating whether the method is native via <code>is_native_ptr</code>
8751 </description>
8752 <origin>jvmdi</origin>
8753 <capabilities>
8754 </capabilities>
8755 <parameters>
8756 <param id="klass">
8757 <jclass method="method"/>
8758 <description>
8759 The class to query.
8760 </description>
8761 </param>
8762 <param id="method">
8763 <jmethodID class="klass"/>
8764 <description>
8765 The method to query.
8766 </description>
8767 </param>
8768 <param id="is_native_ptr">
8769 <outptr><jboolean/></outptr>
8770 <description>
8771 On return, points to the boolean result of this function.
8772 </description>
8773 </param>
8774 </parameters>
8775 <errors>
8776 </errors>
8777 </function>
8778
8779 <function id="IsMethodSynthetic" phase="start" num="77">
8780 <synopsis>Is Method Synthetic</synopsis>
8781 <description>
8782 For the method indicated by <code>method</code>, return a
8783 value indicating whether the method is synthetic via <code>is_synthetic_ptr</code>.
8784 Synthetic methods are generated by the compiler but not present in the
8785 original source code.
8786 </description>
8787 <origin>jvmdi</origin>
8788 <capabilities>
8789 <required id="can_get_synthetic_attribute"></required>
8790 </capabilities>
8791 <parameters>
8792 <param id="klass">
8793 <jclass method="method"/>
8794 <description>
8795 The class to query.
8796 </description>
8797 </param>
8798 <param id="method">
8799 <jmethodID class="klass"/>
8800 <description>
8801 The method to query.
8802 </description>
8803 </param>
8804 <param id="is_synthetic_ptr">
8805 <outptr><jboolean/></outptr>
8806 <description>
8807 On return, points to the boolean result of this function.
8808 </description>
8809 </param>
8810 </parameters>
8811 <errors>
8812 </errors>
8813 </function>
8814
8815 <function id="IsMethodObsolete" phase="start" num="91">
8816 <synopsis>Is Method Obsolete</synopsis>
8817 <description>
8818 Determine if a method ID refers to an
8819 <internallink id="obsoleteMethods">obsolete</internallink>
8820 method version.
8821 </description>
8822 <origin>jvmdi</origin>
8823 <capabilities>
8824 </capabilities>
8825 <parameters>
8826 <param id="klass">
8827 <jclass method="method"/>
8828 <description>
8829 The class to query.
8830 </description>
8831 </param>
8832 <param id="method">
8833 <jmethodID class="klass"/>
8834 <description>
8835 The method ID to query.
8836 </description>
8837 </param>
8838 <param id="is_obsolete_ptr">
8839 <outptr><jboolean/></outptr>
8840 <description>
8841 On return, points to the boolean result of this function.
8842 </description>
8843 </param>
8844 </parameters>
8845 <errors>
8846 </errors>
8847 </function>
8848
8849 <function id="SetNativeMethodPrefix" jkernel="yes" phase="any" num="73" since="1.1">
8850 <synopsis>Set Native Method Prefix</synopsis>
8851 <description>
8852 This function modifies the failure handling of
8853 native method resolution by allowing retry
8854 with a prefix applied to the name.
8855 When used with the
8856 <eventlink id="ClassFileLoadHook">ClassFileLoadHook
8857 event</eventlink>, it enables native methods to be
8858 <internallink id="bci">instrumented</internallink>.
8859 <p/>
8860 Since native methods cannot be directly instrumented
8861 (they have no bytecodes), they must be wrapped with
8862 a non-native method which can be instrumented.
8863 For example, if we had:
8864 <example>
8865 native boolean foo(int x);</example>
8866 <p/>
8867 We could transform the class file (with the
8868 ClassFileLoadHook event) so that this becomes:
8869 <example>
8870 boolean foo(int x) {
8871 <i>... record entry to foo ...</i>
8872 return wrapped_foo(x);
8873 }
8874
8875 native boolean wrapped_foo(int x);</example>
8876 <p/>
8877 Where foo becomes a wrapper for the actual native method
8878 with the appended prefix "wrapped_". Note that
8879 "wrapped_" would be a poor choice of prefix since it
8880 might conceivably form the name of an existing method
8881 thus something like "$$$MyAgentWrapped$$$_" would be
8882 better but would make these examples less readable.
8883 <p/>
8884 The wrapper will allow data to be collected on the native
8885 method call, but now the problem becomes linking up the
8886 wrapped method with the native implementation.
8887 That is, the method <code>wrapped_foo</code> needs to be
8888 resolved to the native implementation of <code>foo</code>,
8889 which might be:
8890 <example>
8891 Java_somePackage_someClass_foo(JNIEnv* env, jint x)</example>
8892 <p/>
8893 This function allows the prefix to be specified and the
8894 proper resolution to occur.
8895 Specifically, when the standard resolution fails, the
8896 resolution is retried taking the prefix into consideration.
8897 There are two ways that resolution occurs, explicit
8898 resolution with the JNI function <code>RegisterNatives</code>
8899 and the normal automatic resolution. For
8900 <code>RegisterNatives</code>, the VM will attempt this
8901 association:
8902 <example>
8903 method(foo) -> nativeImplementation(foo)</example>
8904 <p/>
8905 When this fails, the resolution will be retried with
8906 the specified prefix prepended to the method name,
8907 yielding the correct resolution:
8908 <example>
8909 method(wrapped_foo) -> nativeImplementation(foo)</example>
8910 <p/>
8911 For automatic resolution, the VM will attempt:
8912 <example>
8913 method(wrapped_foo) -> nativeImplementation(wrapped_foo)</example>
8914 <p/>
8915 When this fails, the resolution will be retried with
8916 the specified prefix deleted from the implementation name,
8917 yielding the correct resolution:
8918 <example>
8919 method(wrapped_foo) -> nativeImplementation(foo)</example>
8920 <p/>
8921 Note that since the prefix is only used when standard
8922 resolution fails, native methods can be wrapped selectively.
8923 <p/>
8924 Since each <jvmti/> environment is independent and
8925 can do its own transformation of the bytecodes, more
8926 than one layer of wrappers may be applied. Thus each
8927 environment needs its own prefix. Since transformations
8928 are applied in order, the prefixes, if applied, will
8929 be applied in the same order.
8930 The order of transformation application is described in
8931 the <eventlink id="ClassFileLoadHook"/> event.
8932 Thus if three environments applied
8933 wrappers, <code>foo</code> might become
8934 <code>$env3_$env2_$env1_foo</code>. But if, say,
8935 the second environment did not apply a wrapper to
8936 <code>foo</code> it would be just
8937 <code>$env3_$env1_foo</code>. To be able to
8938 efficiently determine the sequence of prefixes,
8939 an intermediate prefix is only applied if its non-native
8940 wrapper exists. Thus, in the last example, even though
8941 <code>$env1_foo</code> is not a native method, the
8942 <code>$env1_</code> prefix is applied since
8943 <code>$env1_foo</code> exists.
8944 <p/>
8945 Since the prefixes are used at resolution time
8946 and since resolution may be arbitrarily delayed, a
8947 native method prefix must remain set as long as there
8948 are corresponding prefixed native methods.
8949 </description>
8950 <origin>new</origin>
8951 <capabilities>
8952 <required id="can_set_native_method_prefix"></required>
8953 </capabilities>
8954 <parameters>
8955 <param id="prefix">
8956 <inbuf>
8957 <char/>
8958 <nullok>
8959 any existing prefix in this environment is cancelled
8960 </nullok>
8961 </inbuf>
8962 <description>
8963 The prefix to apply, encoded as a
8964 <internallink id="mUTF">modified UTF-8</internallink> string.
8965 </description>
8966 </param>
8967 </parameters>
8968 <errors>
8969 </errors>
8970 </function>
8971
8972 <function id="SetNativeMethodPrefixes" jkernel="yes" phase="any" num="74" since="1.1">
8973 <synopsis>Set Native Method Prefixes</synopsis>
8974 <description>
8975 For a normal agent, <functionlink id="SetNativeMethodPrefix"/>
8976 will provide all needed native method prefixing.
8977 For a meta-agent that performs multiple independent class
8978 file transformations (for example as a proxy for another
8979 layer of agents) this function allows each transformation
8980 to have its own prefix.
8981 The prefixes are applied in the order supplied and are
8982 processed in the same manner as described for the
8983 application of prefixes from multiple <jvmti/> environments
8984 in <functionlink id="SetNativeMethodPrefix"/>.
8985 <p/>
8986 Any previous prefixes are replaced. Thus, calling this
8987 function with a <paramlink id="prefix_count"/> of <code>0</code>
8988 disables prefixing in this environment.
8989 <p/>
8990 <functionlink id="SetNativeMethodPrefix"/> and this function
8991 are the two ways to set the prefixes.
8992 Calling <code>SetNativeMethodPrefix</code> with
8993 a prefix is the same as calling this function with
8994 <paramlink id="prefix_count"/> of <code>1</code>.
8995 Calling <code>SetNativeMethodPrefix</code> with
8996 <code>NULL</code> is the same as calling this function with
8997 <paramlink id="prefix_count"/> of <code>0</code>.
8998 </description>
8999 <origin>new</origin>
9000 <capabilities>
9001 <required id="can_set_native_method_prefix"></required>
9002 </capabilities>
9003 <parameters>
9004 <param id="prefix_count">
9005 <jint min="0"/>
9006 <description>
9007 The number of prefixes to apply.
9008 </description>
9009 </param>
9010 <param id="prefixes">
9011 <agentbuf>
9012 <char/>
9013 </agentbuf>
9014 <description>
9015 The prefixes to apply for this environment, each encoded as a
9016 <internallink id="mUTF">modified UTF-8</internallink> string.
9017 </description>
9018 </param>
9019 </parameters>
9020 <errors>
9021 </errors>
9022 </function>
9023
9024 </category>
9025
9026 <category id="RawMonitors" label="Raw Monitor">
9027
9028 <function id="CreateRawMonitor" phase="onload" callbacksafe="safe" num="31">
9029 <synopsis>Create Raw Monitor</synopsis>
9030 <description>
9031 Create a raw monitor.
9032 </description>
9033 <origin>jvmdi</origin>
9034 <capabilities>
9035 </capabilities>
9036 <parameters>
9037 <param id="name">
9038 <inbuf><char/></inbuf>
9039 <description>
9040 A name to identify the monitor, encoded as a
9041 <internallink id="mUTF">modified UTF-8</internallink> string.
9042 </description>
9043 </param>
9044 <param id="monitor_ptr">
9045 <outptr><jrawMonitorID/></outptr>
9046 <description>
9047 On return, points to the created monitor.
9048 </description>
9049 </param>
9050 </parameters>
9051 <errors>
9052 </errors>
9053 </function>
9054
9055 <function id="DestroyRawMonitor" phase="onload" callbacksafe="safe" num="32">
9056 <synopsis>Destroy Raw Monitor</synopsis>
9057 <description>
9058 Destroy the raw monitor.
9059 If the monitor being destroyed has been entered by this thread, it will be
9060 exited before it is destroyed.
9061 If the monitor being destroyed has been entered by another thread,
9062 an error will be returned and the monitor will not be destroyed.
9063 </description>
9064 <origin>jvmdi</origin>
9065 <capabilities>
9066 </capabilities>
9067 <parameters>
9068 <param id="monitor">
9069 <jrawMonitorID/>
9070 <description>
9071 The monitor
9072 </description>
9073 </param>
9074 </parameters>
9075 <errors>
9076 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9077 Not monitor owner
9078 </error>
9079 </errors>
9080 </function>
9081
9082 <function id="RawMonitorEnter" phase="any" callbacksafe="safe" impl="innative notrace" num="33">
9083 <synopsis>Raw Monitor Enter</synopsis>
9084 <description>
9085 Gain exclusive ownership of a raw monitor.
9086 The same thread may enter a monitor more then once.
9087 The thread must
9088 <functionlink id="RawMonitorExit">exit</functionlink>
9089 the monitor the same number of times as it is entered.
9090 If a monitor is entered during <code>OnLoad</code> (before attached threads exist)
9091 and has not exited when attached threads come into existence, the enter
9092 is considered to have occurred on the main thread.
9093 </description>
9094 <origin>jvmdi</origin>
9095 <capabilities>
9096 </capabilities>
9097 <parameters>
9098 <param id="monitor">
9099 <jrawMonitorID/>
9100 <description>
9101 The monitor
9102 </description>
9103 </param>
9104 </parameters>
9105 <errors>
9106 </errors>
9107 </function>
9108
9109 <function id="RawMonitorExit" phase="any" callbacksafe="safe" impl="innative notrace" num="34">
9110 <synopsis>Raw Monitor Exit</synopsis>
9111 <description>
9112 Release exclusive ownership of a raw monitor.
9113 </description>
9114 <origin>jvmdi</origin>
9115 <capabilities>
9116 </capabilities>
9117 <parameters>
9118 <param id="monitor">
9119 <jrawMonitorID/>
9120 <description>
9121 The monitor
9122 </description>
9123 </param>
9124 </parameters>
9125 <errors>
9126 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9127 Not monitor owner
9128 </error>
9129 </errors>
9130 </function>
9131
9132 <function id="RawMonitorWait" phase="any" callbacksafe="safe" impl="innative notrace" num="35">
9133 <synopsis>Raw Monitor Wait</synopsis>
9134 <description>
9135 Wait for notification of the raw monitor.
9136 <p/>
9137 Causes the current thread to wait until either another thread calls
9138 <functionlink id="RawMonitorNotify"/> or
9139 <functionlink id="RawMonitorNotifyAll"/>
9140 for the specified raw monitor, or the specified
9141 <paramlink id="millis">timeout</paramlink>
9142 has elapsed.
9143 </description>
9144 <origin>jvmdi</origin>
9145 <capabilities>
9146 </capabilities>
9147 <parameters>
9148 <param id="monitor">
9149 <jrawMonitorID/>
9150 <description>
9151 The monitor
9152 </description>
9153 </param>
9154 <param id="millis">
9155 <jlong/>
9156 <description>
9157 The timeout, in milliseconds. If the timeout is
9158 zero, then real time is not taken into consideration
9159 and the thread simply waits until notified.
9160 </description>
9161 </param>
9162 </parameters>
9163 <errors>
9164 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9165 Not monitor owner
9166 </error>
9167 <error id="JVMTI_ERROR_INTERRUPT">
9168 Wait was interrupted, try again
9169 </error>
9170 </errors>
9171 </function>
9172
9173 <function id="RawMonitorNotify" phase="any" callbacksafe="safe" impl="notrace" num="36">
9174 <synopsis>Raw Monitor Notify</synopsis>
9175 <description>
9176 Notify a single thread waiting on the raw monitor.
9177 </description>
9178 <origin>jvmdi</origin>
9179 <capabilities>
9180 </capabilities>
9181 <parameters>
9182 <param id="monitor">
9183 <jrawMonitorID/>
9184 <description>
9185 The monitor
9186 </description>
9187 </param>
9188 </parameters>
9189 <errors>
9190 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9191 Not monitor owner
9192 </error>
9193 </errors>
9194 </function>
9195
9196 <function id="RawMonitorNotifyAll" phase="any" callbacksafe="safe" impl="notrace" num="37">
9197 <synopsis>Raw Monitor Notify All</synopsis>
9198 <description>
9199 Notify all threads waiting on the raw monitor.
9200 </description>
9201 <origin>jvmdi</origin>
9202 <capabilities>
9203 </capabilities>
9204 <parameters>
9205 <param id="monitor">
9206 <jrawMonitorID/>
9207 <description>
9208 The monitor
9209 </description>
9210 </param>
9211 </parameters>
9212 <errors>
9213 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9214 Not monitor owner
9215 </error>
9216 </errors>
9217 </function>
9218
9219 <elide>
9220 <function id="GetRawMonitorUse" num="118">
9221 <synopsis>Get Raw Monitor Use</synopsis>
9222 <description>
9223 The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure
9224 are filled in with information about usage of the raw monitor.
9225 </description>
9226 <origin>new</origin>
9227 <capabilities>
9228 <required id="can_get_raw_monitor_usage"></required>
9229 </capabilities>
9230 <parameters>
9231 <param id="monitor">
9232 <jrawMonitorID/>
9233 <description>
9234 the raw monitor to query.
9235 </description>
9236 </param>
9237 <param id="info_ptr">
9238 <outptr><struct>jvmtiMonitorUsage</struct></outptr>
9239 <description>
9240 On return, filled with monitor information for the
9241 specified raw monitor.
9242 </description>
9243 </param>
9244 </parameters>
9245 <errors>
9246 </errors>
9247 </function>
9248
9249 <function id="GetRawMonitors" num="119">
9250 <synopsis>Get Raw Monitors</synopsis>
9251 <description>
9252 Return the list of raw monitors.
9253 <p/>
9254 Note: details about each monitor can be examined with
9255 <functionlink id="GetRawMonitorUse"></functionlink>.
9256 </description>
9257 <origin>new</origin>
9258 <capabilities>
9259 <required id="can_get_raw_monitor_usage"></required>
9260 </capabilities>
9261 <parameters>
9262 <param id="monitorCnt">
9263 <outptr><jint/></outptr>
9264 <description>
9265 On return, pointer to the number
9266 of monitors returned in <code>monitors_ptr</code>.
9267 </description>
9268 </param>
9269 <param id="monitors_ptr">
9270 <allocbuf outcount="monitorCnt"><jrawMonitorID/></allocbuf>
9271 <description>
9272 On return, pointer to the monitor list.
9273 </description>
9274 </param>
9275 </parameters>
9276 <errors>
9277 </errors>
9278 </function>
9279 </elide>
9280 </category>
9281
9282 <category id="jniIntercept" label="JNI Function Interception">
9283
9284 <intro>
9285 Provides the ability to intercept and resend
9286 Java Native Interface (JNI) function calls
9287 by manipulating the JNI function table.
9288 See <externallink id="jni/functions.html">JNI
9289 Functions</externallink> in the <i>Java Native Interface Specification</i>.
9290 <p/>
9291 The following example illustrates intercepting the
9292 <code>NewGlobalRef</code> JNI call in order to count reference
9293 creation.
9294 <example>
9295 JNIEnv original_jni_Functions;
9296 JNIEnv redirected_jni_Functions;
9297 int my_global_ref_count = 0;
9298
9299 jobject
9300 MyNewGlobalRef(JNIEnv *jni_env, jobject lobj) {
9301 ++my_global_ref_count;
9302 return originalJNIFunctions->NewGlobalRef(env, lobj);
9303 }
9304
9305 void
9306 myInit() {
9307 jvmtiError err;
9308
9309 err = (*jvmti_env)->GetJNIFunctionTable(jvmti_env, &original_jni_Functions);
9310 if (err != JVMTI_ERROR_NONE) {
9311 die();
9312 }
9313 err = (*jvmti_env)->GetJNIFunctionTable(jvmti_env, &redirected_jni_Functions);
9314 if (err != JVMTI_ERROR_NONE) {
9315 die();
9316 }
9317 redirectedJNIFunctions->NewGlobalRef = MyNewGlobalRef;
9318 err = (*jvmti_env)->SetJNIFunctionTable(jvmti_env, redirected_jni_Functions);
9319 if (err != JVMTI_ERROR_NONE) {
9320 die();
9321 }
9322 }
9323 </example>
9324 Sometime after <code>myInit</code> is called the user's JNI
9325 code is executed which makes the call to create a new global
9326 reference. Instead of going to the normal JNI implementation
9327 the call goes to <code>myNewGlobalRef</code>. Note that a
9328 copy of the original function table is kept so that the normal
9329 JNI function can be called after the data is collected.
9330 Note also that any JNI functions which are not overwritten
9331 will behave normally.
9332 <todo>
9333 check that the example compiles and executes.
9334 </todo>
9335 </intro>
9336
9337 <function id="SetJNIFunctionTable" phase="start" num="120">
9338 <synopsis>Set JNI Function Table</synopsis>
9339 <description>
9340 Set the JNI function table
9341 in all current and future JNI environments.
9342 As a result, all future JNI calls are directed to the specified functions.
9343 Use <functionlink id="GetJNIFunctionTable"></functionlink> to get the
9344 function table to pass to this function.
9345 For this function to take effect the the updated table entries must be
9346 used by the JNI clients.
9347 Since the table is defined <code>const</code> some compilers may optimize
9348 away the access to the table, thus preventing this function from taking
9349 effect.
9350 The table is copied--changes to the local copy of the
9351 table have no effect.
9352 This function affects only the function table, all other aspects of the environment are
9353 unaffected.
9354 See the examples <internallink id="jniIntercept">above</internallink>.
9355 </description>
9356 <origin>new</origin>
9357 <capabilities>
9358 </capabilities>
9359 <parameters>
9360 <param id="function_table">
9361 <inptr>
9362 <struct>jniNativeInterface</struct>
9363 </inptr>
9364 <description>
9365 Points to the new JNI function table.
9366 </description>
9367 </param>
9368 </parameters>
9369 <errors>
9370 </errors>
9371 </function>
9372
9373 <function id="GetJNIFunctionTable" phase="start" num="121">
9374 <synopsis>Get JNI Function Table</synopsis>
9375 <description>
9376 Get the JNI function table.
9377 The JNI function table is copied into allocated memory.
9378 If <functionlink id="SetJNIFunctionTable"></functionlink>
9379 has been called, the modified (not the original) function
9380 table is returned.
9381 Only the function table is copied, no other aspects of the environment
9382 are copied.
9383 See the examples <internallink id="jniIntercept">above</internallink>.
9384 </description>
9385 <origin>new</origin>
9386 <capabilities>
9387 </capabilities>
9388 <parameters>
9389 <param id="function_table">
9390 <allocbuf>
9391 <struct>jniNativeInterface</struct>
9392 </allocbuf>
9393 <description>
9394 On return, <code>*function_table</code>
9395 points a newly allocated copy of the JNI function table.
9396 </description>
9397 </param>
9398 </parameters>
9399 <errors>
9400 </errors>
9401 </function>
9402
9403 </category>
9404
9405 <category id="eventManagement" label="Event Management">
9406
9407 <function id="SetEventCallbacks" jkernel="yes" phase="onload" num="122">
9408 <synopsis>Set Event Callbacks</synopsis>
9409 <description>
9410 Set the functions to be called for each event.
9411 The callbacks are specified by supplying a replacement function table.
9412 The function table is copied--changes to the local copy of the
9413 table have no effect.
9414 This is an atomic action, all callbacks are set at once.
9415 No events are sent before this function is called.
9416 When an entry is <code>NULL</code> or when the event is beyond
9417 <paramlink id="size_of_callbacks"></paramlink> no event is sent.
9418 Details on events are
9419 described <internallink id="EventSection">later</internallink> in this document.
9420 An event must be enabled and have a callback in order to be
9421 sent--the order in which this function and
9422 <functionlink id="SetEventNotificationMode"></functionlink>
9423 are called does not affect the result.
9424 </description>
9425 <origin>new</origin>
9426 <capabilities>
9427 </capabilities>
9428 <parameters>
9429 <param id="callbacks">
9430 <inptr>
9431 <struct>jvmtiEventCallbacks</struct>
9432 <nullok>remove the existing callbacks</nullok>
9433 </inptr>
9434 <description>
9435 The new event callbacks.
9436 </description>
9437 </param>
9438 <param id="size_of_callbacks">
9439 <jint min="0"/>
9440 <description>
9441 <code>sizeof(jvmtiEventCallbacks)</code>--for version
9442 compatibility.
9443 </description>
9444 </param>
9445 </parameters>
9446 <errors>
9447 </errors>
9448 </function>
9449
9450 <function id="SetEventNotificationMode" jkernel="yes" phase="onload" num="2">
9451 <synopsis>Set Event Notification Mode</synopsis>
9452 <description>
9453 Control the generation of events.
9454 <constants id="jvmtiEventMode" label="Event Enable/Disable" kind="enum">
9455 <constant id="JVMTI_ENABLE" num="1">
9456 If <paramlink id="mode"></paramlink> is <code>JVMTI_ENABLE</code>,
9457 the event <paramlink id="event_type"></paramlink> will be enabled
9458 </constant>
9459 <constant id="JVMTI_DISABLE" num="0">
9460 If <paramlink id="mode"></paramlink> is <code>JVMTI_DISABLE</code>,
9461 the event <paramlink id="event_type"></paramlink> will be disabled
9462 </constant>
9463 </constants>
9464 If <code>event_thread</code> is <code>NULL</code>,
9465 the event is enabled or disabled globally; otherwise, it is
9466 enabled or disabled for a particular thread.
9467 An event is generated for
9468 a particular thread if it is enabled either at the thread or global
9469 levels.
9470 <p/>
9471 See <internallink id="EventIndex">below</internallink> for information on specific events.
9472 <p/>
9473 The following events cannot be controlled at the thread
9474 level through this function.
9475 <ul>
9476 <li><eventlink id="VMInit"></eventlink></li>
9477 <li><eventlink id="VMStart"></eventlink></li>
9478 <li><eventlink id="VMDeath"></eventlink></li>
9479 <li><eventlink id="ThreadStart"></eventlink></li>
9480 <li><eventlink id="CompiledMethodLoad"></eventlink></li>
9481 <li><eventlink id="CompiledMethodUnload"></eventlink></li>
9482 <li><eventlink id="DynamicCodeGenerated"></eventlink></li>
9483 <li><eventlink id="DataDumpRequest"></eventlink></li>
9484 </ul>
9485 <p/>
9486 Initially, no events are enabled at either the thread level
9487 or the global level.
9488 <p/>
9489 Any needed capabilities (see Event Enabling Capabilities below) must be possessed
9490 before calling this function.
9491 <p/>
9492 Details on events are
9493 described <internallink id="EventSection">below</internallink>.
9494 </description>
9495 <origin>jvmdiClone</origin>
9496 <eventcapabilities></eventcapabilities>
9497 <parameters>
9498 <param id="mode">
9499 <enum>jvmtiEventMode</enum>
9500 <description>
9501 <code>JVMTI_ENABLE</code> or <code>JVMTI_DISABLE</code>
9502 </description>
9503 </param>
9504 <param id="event_type">
9505 <enum>jvmtiEvent</enum>
9506 <description>
9507 the event to control
9508 </description>
9509 </param>
9510 <param id="event_thread">
9511 <ptrtype>
9512 <jthread impl="noconvert"/>
9513 <nullok>event is controlled at the global level</nullok>
9514 </ptrtype>
9515 <description>
9516 The thread to control
9517 </description>
9518 </param>
9519 <param id="...">
9520 <varargs/>
9521 <description>
9522 for future expansion
9523 </description>
9524 </param>
9525 </parameters>
9526 <errors>
9527 <error id="JVMTI_ERROR_INVALID_THREAD">
9528 <paramlink id="event_thread"/> is non-<code>NULL</code> and is not a valid thread.
9529 </error>
9530 <error id="JVMTI_ERROR_THREAD_NOT_ALIVE">
9531 <paramlink id="event_thread"/> is non-<code>NULL</code> and is not live (has not been started or is now dead).
9532 </error>
9533 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9534 thread level control was attempted on events which do not
9535 permit thread level control.
9536 </error>
9537 <error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY">
9538 The Required Event Enabling Capability is not possessed.
9539 </error>
9540 </errors>
9541 </function>
9542
9543 <function id="GenerateEvents" num="123">
9544 <synopsis>Generate Events</synopsis>
9545 <description>
9546 Generate events to represent the current state of the VM.
9547 For example, if <paramlink id="event_type"/> is
9548 <code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code>,
9549 a <eventlink id="CompiledMethodLoad"></eventlink> event will be
9550 sent for each currently compiled method.
9551 Methods that were loaded and now have been unloaded are not sent.
9552 The history of what events have previously been sent does not
9553 effect what events are sent by this function--for example,
9554 all currently compiled methods
9555 will be sent each time this function is called.
9556 <p/>
9557 This function is useful when
9558 events may have been missed due to the agent attaching after program
9559 execution begins; this function generates the missed events.
9560 <p/>
9561 Attempts to execute Java programming language code or
9562 JNI functions may be paused until this function returns -
9563 so neither should be called from the thread sending the event.
9564 This function returns only after the missed events have been
9565 sent, processed and have returned.
9566 The event may be sent on a different thread than the thread
9567 on which the event occurred.
9568 The callback for the event must be set with
9569 <functionlink id="SetEventCallbacks"></functionlink>
9570 and the event must be enabled with
9571 <functionlink id="SetEventNotificationMode"></functionlink>
9572 or the events will not occur.
9573 If the VM no longer has the information to generate some or
9574 all of the requested events, the events are simply not sent -
9575 no error is returned.
9576 <p/>
9577 Only the following events are supported:
9578 <ul>
9579 <li><eventlink id="CompiledMethodLoad"></eventlink></li>
9580 <li><eventlink id="DynamicCodeGenerated"></eventlink></li>
9581 </ul>
9582 </description>
9583 <origin>new</origin>
9584 <capabilities>
9585 <capability id="can_generate_compiled_method_load_events"></capability>
9586 </capabilities>
9587 <parameters>
9588 <param id="event_type">
9589 <enum>jvmtiEvent</enum>
9590 <description>
9591 The type of event to generate. Must be one of these:
9592 <ul>
9593 <li><eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink></li>
9594 <li><eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink></li>
9595 </ul>
9596 </description>
9597 </param>
9598 </parameters>
9599 <errors>
9600 <error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY">
9601 <paramlink id="event_type"/> is
9602 <eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink>
9603 and <fieldlink id="can_generate_compiled_method_load_events" struct="jvmtiCapabilities"></fieldlink>
9604 is <code>false</code>.
9605 </error>
9606 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9607 <paramlink id="event_type"/> is other than
9608 <eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink>
9609 or <eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink>.
9610 </error>
9611 </errors>
9612 </function>
9613
9614 </category>
9615
9616 <category id="extension" label="Extension Mechanism">
9617
9618 <intro>
9619 These functions
9620 allow a <jvmti/> implementation to provide functions and events
9621 beyond those defined in this specification.
9622 <p/>
9623 Both extension functions and extension events have parameters
9624 each of which has a 'type' and 'kind' chosen from the following tables:
9625
9626 <constants id="jvmtiParamTypes" label="Extension Function/Event Parameter Types" kind="enum">
9627 <constant id="JVMTI_TYPE_JBYTE" num="101">
9628 Java programming language primitive type - <code>byte</code>.
9629 JNI type <code>jbyte</code>.
9630 </constant>
9631 <constant id="JVMTI_TYPE_JCHAR" num="102">
9632 Java programming language primitive type - <code>char</code>.
9633 JNI type <code>jchar</code>.
9634 </constant>
9635 <constant id="JVMTI_TYPE_JSHORT" num="103">
9636 Java programming language primitive type - <code>short</code>.
9637 JNI type <code>jshort</code>.
9638 </constant>
9639 <constant id="JVMTI_TYPE_JINT" num="104">
9640 Java programming language primitive type - <code>int</code>.
9641 JNI type <datalink id="jint"></datalink>.
9642 </constant>
9643 <constant id="JVMTI_TYPE_JLONG" num="105">
9644 Java programming language primitive type - <code>long</code>.
9645 JNI type <datalink id="jlong"></datalink>.
9646 </constant>
9647 <constant id="JVMTI_TYPE_JFLOAT" num="106">
9648 Java programming language primitive type - <code>float</code>.
9649 JNI type <datalink id="jfloat"></datalink>.
9650 </constant>
9651 <constant id="JVMTI_TYPE_JDOUBLE" num="107">
9652 Java programming language primitive type - <code>double</code>.
9653 JNI type <datalink id="jdouble"></datalink>.
9654 </constant>
9655 <constant id="JVMTI_TYPE_JBOOLEAN" num="108">
9656 Java programming language primitive type - <code>boolean</code>.
9657 JNI type <datalink id="jboolean"></datalink>.
9658 </constant>
9659 <constant id="JVMTI_TYPE_JOBJECT" num="109">
9660 Java programming language object type - <code>java.lang.Object</code>.
9661 JNI type <datalink id="jobject"></datalink>.
9662 Returned values are JNI local references and must be managed.
9663 </constant>
9664 <constant id="JVMTI_TYPE_JTHREAD" num="110">
9665 Java programming language object type - <code>java.lang.Thread</code>.
9666 <jvmti/> type <datalink id="jthread"></datalink>.
9667 Returned values are JNI local references and must be managed.
9668 </constant>
9669 <constant id="JVMTI_TYPE_JCLASS" num="111">
9670 Java programming language object type - <code>java.lang.Class</code>.
9671 JNI type <datalink id="jclass"></datalink>.
9672 Returned values are JNI local references and must be managed.
9673 </constant>
9674 <constant id="JVMTI_TYPE_JVALUE" num="112">
9675 Union of all Java programming language primitive and object types -
9676 JNI type <datalink id="jvalue"></datalink>.
9677 Returned values which represent object types are JNI local references and must be managed.
9678 </constant>
9679 <constant id="JVMTI_TYPE_JFIELDID" num="113">
9680 Java programming language field identifier -
9681 JNI type <datalink id="jfieldID"></datalink>.
9682 </constant>
9683 <constant id="JVMTI_TYPE_JMETHODID" num="114">
9684 Java programming language method identifier -
9685 JNI type <datalink id="jmethodID"></datalink>.
9686 </constant>
9687 <constant id="JVMTI_TYPE_CCHAR" num="115">
9688 C programming language type - <code>char</code>.
9689 </constant>
9690 <constant id="JVMTI_TYPE_CVOID" num="116">
9691 C programming language type - <code>void</code>.
9692 </constant>
9693 <constant id="JVMTI_TYPE_JNIENV" num="117">
9694 JNI environment - <code>JNIEnv</code>.
9695 Should be used with the correct <datalink id="jvmtiParamKind"/> to make it a pointer type.
9696 </constant>
9697 </constants>
9698
9699 <constants id="jvmtiParamKind" label="Extension Function/Event Parameter Kinds" kind="enum">
9700 <constant id="JVMTI_KIND_IN" num="91">
9701 Ingoing argument - <code>foo</code>.
9702 </constant>
9703 <constant id="JVMTI_KIND_IN_PTR" num="92">
9704 Ingoing pointer argument - <code>const foo*</code>.
9705 </constant>
9706 <constant id="JVMTI_KIND_IN_BUF" num="93">
9707 Ingoing array argument - <code>const foo*</code>.
9708 </constant>
9709 <constant id="JVMTI_KIND_ALLOC_BUF" num="94">
9710 Outgoing allocated array argument - <code>foo**</code>.
9711 Free with <code>Deallocate</code>.
9712 </constant>
9713 <constant id="JVMTI_KIND_ALLOC_ALLOC_BUF" num="95">
9714 Outgoing allocated array of allocated arrays argument - <code>foo***</code>.
9715 Free with <code>Deallocate</code>.
9716 </constant>
9717 <constant id="JVMTI_KIND_OUT" num="96">
9718 Outgoing argument - <code>foo*</code>.
9719 </constant>
9720 <constant id="JVMTI_KIND_OUT_BUF" num="97">
9721 Outgoing array argument (pre-allocated by agent) - <code>foo*</code>.
9722 Do not <code>Deallocate</code>.
9723 </constant>
9724 </constants>
9725
9726 </intro>
9727
9728 <typedef id="jvmtiParamInfo" label="Extension Function/Event Parameter Info">
9729 <field id="name">
9730 <allocfieldbuf><char/></allocfieldbuf>
9731 <description>
9732 The parameter name, encoded as a
9733 <internallink id="mUTF">modified UTF-8</internallink> string
9734 </description>
9735 </field>
9736 <field id="kind">
9737 <enum>jvmtiParamKind</enum>
9738 <description>
9739 The kind of the parameter - type modifiers
9740 </description>
9741 </field>
9742 <field id="base_type">
9743 <enum>jvmtiParamTypes</enum>
9744 <description>
9745 The base type of the parameter - modified by <code>kind</code>
9746 </description>
9747 </field>
9748 <field id="null_ok">
9749 <jboolean/>
9750 <description>
9751 Is a <code>NULL</code> argument permitted? Applies only to pointer and object types.
9752 </description>
9753 </field>
9754 </typedef>
9755
9756 <callback id="jvmtiExtensionFunction">
9757 <enum>jvmtiError</enum>
9758 <synopsis>Extension Function</synopsis>
9759 <description>
9760 This is the implementation-specific extension function.
9761 </description>
9762 <parameters>
9763 <param id="jvmti_env">
9764 <outptr>
9765 <struct>jvmtiEnv</struct>
9766 </outptr>
9767 <description>
9768 The <jvmti/> environment is the only fixed parameter for extension functions.
9769 </description>
9770 </param>
9771 <param id="...">
9772 <varargs/>
9773 <description>
9774 The extension function-specific parameters
9775 </description>
9776 </param>
9777 </parameters>
9778 </callback>
9779
9780 <function id="GetExtensionFunctions" phase="onload" num="124">
9781 <synopsis>Get Extension Functions</synopsis>
9782
9783 <typedef id="jvmtiExtensionFunctionInfo" label="Extension Function Info">
9784 <field id="func">
9785 <ptrtype>
9786 <struct>jvmtiExtensionFunction</struct>
9787 </ptrtype>
9788 <description>
9789 The actual function to call
9790 </description>
9791 </field>
9792 <field id="id">
9793 <allocfieldbuf><char/></allocfieldbuf>
9794 <description>
9795 The identifier for the extension function, encoded as a
9796 <internallink id="mUTF">modified UTF-8</internallink> string.
9797 Uses package name conventions.
9798 For example, <code>com.sun.hotspot.bar</code>
9799 </description>
9800 </field>
9801 <field id="short_description">
9802 <allocfieldbuf><char/></allocfieldbuf>
9803 <description>
9804 A one sentence description of the function, encoded as a
9805 <internallink id="mUTF">modified UTF-8</internallink> string.
9806 </description>
9807 </field>
9808 <field id="param_count">
9809 <jint/>
9810 <description>
9811 The number of parameters excluding <code>jvmtiEnv *jvmti_env</code>
9812 </description>
9813 </field>
9814 <field id="params">
9815 <allocfieldbuf outcount="param_count">
9816 <struct>jvmtiParamInfo</struct>
9817 </allocfieldbuf>
9818 <description>
9819 Array of
9820 <fieldlink id="param_count" struct="jvmtiExtensionFunctionInfo"></fieldlink>
9821 parameters (<code>jvmtiEnv *jvmti_env</code> excluded)
9822 </description>
9823 </field>
9824 <field id="error_count">
9825 <jint/>
9826 <description>
9827 The number of possible error returns (excluding universal errors)
9828 </description>
9829 </field>
9830 <field id="errors">
9831 <allocfieldbuf outcount="error_count">
9832 <enum>jvmtiError</enum>
9833 </allocfieldbuf>
9834 <description>
9835 Array of <fieldlink id="error_count" struct="jvmtiExtensionFunctionInfo"></fieldlink>
9836 possible errors
9837 </description>
9838 </field>
9839 </typedef>
9840
9841 <description>
9842 Returns the set of extension functions.
9843 </description>
9844 <origin>new</origin>
9845 <capabilities>
9846 </capabilities>
9847 <parameters>
9848 <param id="extension_count_ptr">
9849 <outptr><jint/></outptr>
9850 <description>
9851 On return, points to the number of extension functions
9852 </description>
9853 </param>
9854 <param id="extensions">
9855 <allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionFunctionInfo</struct></allocbuf>
9856 <description>
9857 Returns an array of extension function info, one per function
9858 </description>
9859 </param>
9860 </parameters>
9861 <errors>
9862 </errors>
9863 </function>
9864
9865 <function id="GetExtensionEvents" phase="onload" num="125">
9866 <synopsis>Get Extension Events</synopsis>
9867
9868 <typedef id="jvmtiExtensionEventInfo" label="Extension Event Info">
9869 <field id="extension_event_index">
9870 <jint/>
9871 <description>
9872 The identifying index of the event
9873 </description>
9874 </field>
9875 <field id="id">
9876 <allocfieldbuf><char/></allocfieldbuf>
9877 <description>
9878 The identifier for the extension event, encoded as a
9879 <internallink id="mUTF">modified UTF-8</internallink> string.
9880 Uses package name conventions.
9881 For example, <code>com.sun.hotspot.bar</code>
9882 </description>
9883 </field>
9884 <field id="short_description">
9885 <allocfieldbuf><char/></allocfieldbuf>
9886 <description>
9887 A one sentence description of the event, encoded as a
9888 <internallink id="mUTF">modified UTF-8</internallink> string.
9889 </description>
9890 </field>
9891 <field id="param_count">
9892 <jint/>
9893 <description>
9894 The number of parameters excluding <code>jvmtiEnv *jvmti_env</code>
9895 </description>
9896 </field>
9897 <field id="params">
9898 <allocfieldbuf outcount="param_count">
9899 <struct>jvmtiParamInfo</struct>
9900 </allocfieldbuf>
9901 <description>
9902 Array of
9903 <fieldlink id="param_count" struct="jvmtiExtensionEventInfo"></fieldlink>
9904 parameters (<code>jvmtiEnv *jvmti_env</code> excluded)
9905 </description>
9906 </field>
9907 </typedef>
9908
9909 <description>
9910 Returns the set of extension events.
9911 </description>
9912 <origin>new</origin>
9913 <capabilities>
9914 </capabilities>
9915 <parameters>
9916 <param id="extension_count_ptr">
9917 <outptr><jint/></outptr>
9918 <description>
9919 On return, points to the number of extension events
9920 </description>
9921 </param>
9922 <param id="extensions">
9923 <allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionEventInfo</struct></allocbuf>
9924 <description>
9925 Returns an array of extension event info, one per event
9926 </description>
9927 </param>
9928 </parameters>
9929 <errors>
9930 </errors>
9931 </function>
9932
9933 <callback id="jvmtiExtensionEvent">
9934 <void/>
9935 <synopsis>Extension Event</synopsis>
9936 <description>
9937 This is the implementation-specific event.
9938 The event handler is set with
9939 <functionlink id="SetExtensionEventCallback"/>.
9940 <p/>
9941 Event handlers for extension events must be declared varargs to match this definition.
9942 Failure to do so could result in calling convention mismatch and undefined behavior
9943 on some platforms.
9944 <p/>
9945 For example, if the <code>jvmtiParamInfo</code>
9946 returned by <functionlink id="GetExtensionEvents"/> indicates that
9947 there is a <code>jint</code> parameter, the event handler should be
9948 declared:
9949 <example>
9950 void JNICALL myHandler(jvmtiEnv* jvmti_env, jint myInt, ...)
9951 </example>
9952 Note the terminal "<code>...</code>" which indicates varargs.
9953 </description>
9954 <parameters>
9955 <param id="jvmti_env">
9956 <outptr>
9957 <struct>jvmtiEnv</struct>
9958 </outptr>
9959 <description>
9960 The <jvmti/> environment is the only fixed parameter for extension events.
9961 </description>
9962 </param>
9963 <param id="...">
9964 <varargs/>
9965 <description>
9966 The extension event-specific parameters
9967 </description>
9968 </param>
9969 </parameters>
9970 </callback>
9971
9972 <function id="SetExtensionEventCallback" phase="onload" num="126">
9973 <synopsis>Set Extension Event Callback</synopsis>
9974
9975 <description>
9976 Sets the callback function for an extension event and
9977 enables the event. Or, if the callback is <code>NULL</code>, disables
9978 the event. Note that unlike standard events, setting
9979 the callback and enabling the event are a single operation.
9980 </description>
9981 <origin>new</origin>
9982 <capabilities>
9983 </capabilities>
9984 <parameters>
9985 <param id="extension_event_index">
9986 <jint/>
9987 <description>
9988 Identifies which callback to set.
9989 This index is the
9990 <fieldlink id="extension_event_index" struct="jvmtiExtensionEventInfo"></fieldlink>
9991 field of
9992 <datalink id="jvmtiExtensionEventInfo"/>.
9993 </description>
9994 </param>
9995 <param id="callback">
9996 <ptrtype>
9997 <struct>jvmtiExtensionEvent</struct>
9998 <nullok>disable the event</nullok>
9999 </ptrtype>
10000 <description>
10001 If <code>callback</code> is non-<code>NULL</code>,
10002 set <code>callback</code> to be the event callback function
10003 and enable the event.
10004 </description>
10005 </param>
10006 </parameters>
10007 <errors>
10008 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
10009 <paramlink id="extension_event_index"/> is not an
10010 <fieldlink id="extension_event_index"
10011 struct="jvmtiExtensionEventInfo"/>
10012 returned by
10013 <functionlink id="GetExtensionEvents"/>
10014 </error>
10015 </errors>
10016 </function>
10017
10018 </category>
10019
10020 <category id="capability" label="Capability">
10021
10022 <intro>
10023 The capabilities functions allow you to change the
10024 functionality available to <jvmti/>--that is,
10025 which <jvmti/>
10026 functions can be called, what events can be generated,
10027 and what functionality these events and functions can
10028 provide.
10029 <p/>
10030 The "Capabilities" section of each function and event describe which
10031 capabilities, if any, they are associated with. "Required Functionality"
10032 means it is available for use and no capabilities must be added to use it.
10033 "Optional Functionality" means the agent must possess the capability
10034 before it can be used.
10035 To possess a capability, the agent must
10036 <functionlink id="AddCapabilities">add the capability</functionlink>.
10037 "Optional Features" describe capabilities which,
10038 if added, extend the feature set.
10039 <p/>
10040 The potentially available capabilities of each <jvmti/> implementation are different.
10041 Depending on the implementation, a capability:
10042 <ul>
10043 <li>may never be added</li>
10044 <li>may be added in either the <code>OnLoad</code> or live phase in any environment</li>
10045 <li>may be added only during the <code>OnLoad</code> phase</li>
10046 <li>may be possessed by only one environment at a time</li>
10047 <li>may be possessed by only one environment at a time,
10048 and only during the <code>OnLoad</code> phase</li>
10049 <li>and so on ...</li>
10050 </ul>
10051 Frequently, the addition of a capability may incur a cost in execution speed, start up
10052 time, and/or memory footprint. Note that the overhead of using a capability
10053 is completely different than the overhead of possessing a capability.
10054 Take single stepping as an example. When single stepping is on (that
10055 is, when the event is enabled and thus actively sending events)
10056 the overhead of sending and processing an event
10057 on each instruction is huge in any implementation.
10058 However, the overhead of possessing the capability may be small or large,
10059 depending on the implementation. Also, when and if a capability is potentially
10060 available depends on the implementation. Some examples:
10061 <ul>
10062 <li>One VM might perform all execution by compiling bytecodes into
10063 native code and be unable to generate single step instructions.
10064 In this implementation the capability can not be added.</li>
10065 <li>Another VM may be able to switch execution to a single stepping
10066 interpreter at any time. In this implementation, having the capability has no
10067 overhead and could be added at any time.</li>
10068 <li>Yet another VM might be able to choose a bytecode compiling or single stepping capable interpreted
10069 execution engine at start up, but be unable to switch between them.
10070 In this implementation the capability would need to be added
10071 during the <code>OnLoad</code> phase (before bytecode
10072 execution begins) and would have a large impact on execution speed
10073 even if single stepping was never used.</li>
10074 <li>Still another VM might be able to add an "is single stepping on" check
10075 into compiled bytecodes or a generated interpreter. Again in this implementation
10076 the capability would need to be added during the <code>OnLoad</code> phase but the overhead (a test
10077 and branch on each instruction) would be considerably less.</li>
10078 </ul>
10079 <p/>
10080 Each <jvmti/> <internallink id="environments">environment</internallink>
10081 has its own set of capabilities.
10082 Initially, that set is empty.
10083 Any desired capability must be added.
10084 If possible, capabilities should be added during the <code>OnLoad</code> phase. For most
10085 virtual machines certain capabilities require special set up for
10086 the virtual machine and this set up must happen
10087 during the <code>OnLoad</code> phase, before the virtual machine begins execution.
10088 Once a capability is added, it can
10089 only be removed if explicitly relinquished by the environment.
10090 <p/>
10091 The agent can,
10092 <functionlink id="GetPotentialCapabilities">determine what
10093 capabilities this VM can potentially provide</functionlink>,
10094 <functionlink id="AddCapabilities">add the capabilities
10095 to be used</functionlink>,
10096 <functionlink id="RelinquishCapabilities">release capabilities
10097 which are no longer needed</functionlink>, and
10098 <functionlink id="GetCapabilities">examine the currently available
10099 capabilities</functionlink>.
10100 </intro>
10101
10102 <intro id="capabilityExamples" label="Capability Examples">
10103 For example, a freshly started agent (in the <code>OnLoad</code> function)
10104 wants to enable all possible capabilities.
10105 Note that, in general, this is not advisable as the agent may suffer
10106 a performance penalty for functionality it is not using.
10107 The code might look like this in C:
10108 <example>
10109 jvmtiCapabilities capa;
10110 jvmtiError err;
10111
10112 err = (*jvmti)->GetPotentialCapabilities(jvmti, &capa);
10113 if (err == JVMTI_ERROR_NONE) {
10114 err = (*jvmti)->AddCapabilities(jvmti, &capa);
10115 </example>
10116 For example, if an agent wants to check if it can get
10117 the bytecodes of a method (that is, it wants to check
10118 if it previously added this capability and has not
10119 relinquished it), the code might
10120 look like this in C:
10121 <example>
10122 jvmtiCapabilities capa;
10123 jvmtiError err;
10124
10125 err = (*jvmti)->GetCapabilities(jvmti, &capa);
10126 if (err == JVMTI_ERROR_NONE) {
10127 if (capa.can_get_bytecodes) { ... } }
10128 </example>
10129 </intro>
10130
10131 <capabilitiestypedef id="jvmtiCapabilities" label="The Capabilities Structure">
10132 <description>
10133 The functions in this category use this capabilities structure
10134 which contains boolean flags corresponding to each capability:
10135 </description>
10136 <capabilityfield id="can_tag_objects">
10137 <description>
10138 Can set and get tags, as described in the
10139 <internallink id="Heap">Heap category</internallink>.
10140 </description>
10141 </capabilityfield>
10142 <capabilityfield id="can_generate_field_modification_events">
10143 <description>
10144 Can set watchpoints on field modification -
10145 <functionlink id="SetFieldModificationWatch"></functionlink>
10146 </description>
10147 </capabilityfield>
10148 <capabilityfield id="can_generate_field_access_events">
10149 <description>
10150 Can set watchpoints on field access -
10151 <functionlink id="SetFieldAccessWatch"></functionlink>
10152 </description>
10153 </capabilityfield>
10154 <capabilityfield id="can_get_bytecodes">
10155 <description>
10156 Can get bytecodes of a method <functionlink id="GetBytecodes"></functionlink>
10157 </description>
10158 </capabilityfield>
10159 <capabilityfield id="can_get_synthetic_attribute">
10160 <description>
10161 Can test if a field or method is synthetic -
10162 <functionlink id="IsFieldSynthetic"></functionlink> and
10163 <functionlink id="IsMethodSynthetic"></functionlink>
10164 </description>
10165 </capabilityfield>
10166 <capabilityfield id="can_get_owned_monitor_info">
10167 <description>
10168 Can get information about ownership of monitors -
10169 <functionlink id="GetOwnedMonitorInfo"></functionlink>
10170 </description>
10171 </capabilityfield>
10172 <capabilityfield id="can_get_current_contended_monitor">
10173 <description>
10174 Can <functionlink id="GetCurrentContendedMonitor"></functionlink>
10175 </description>
10176 </capabilityfield>
10177 <capabilityfield id="can_get_monitor_info">
10178 <description>
10179 Can <functionlink id="GetObjectMonitorUsage"></functionlink>
10180 </description>
10181 </capabilityfield>
10182 <capabilityfield id="can_pop_frame">
10183 <description>
10184 Can pop frames off the stack - <functionlink id="PopFrame"></functionlink>
10185 </description>
10186 </capabilityfield>
10187 <capabilityfield id="can_redefine_classes">
10188 <description>
10189 Can redefine classes with <functionlink id="RedefineClasses"/>.
10190 </description>
10191 </capabilityfield>
10192 <capabilityfield id="can_signal_thread">
10193 <description>
10194 Can send stop or interrupt to threads
10195 </description>
10196 </capabilityfield>
10197 <capabilityfield id="can_get_source_file_name">
10198 <description>
10199 Can get the source file name of a class
10200 </description>
10201 </capabilityfield>
10202 <capabilityfield id="can_get_line_numbers">
10203 <description>
10204 Can get the line number table of a method
10205 </description>
10206 </capabilityfield>
10207 <capabilityfield id="can_get_source_debug_extension">
10208 <description>
10209 Can get the source debug extension of a class
10210 </description>
10211 </capabilityfield>
10212 <capabilityfield id="can_access_local_variables">
10213 <description>
10214 Can set and get local variables
10215 </description>
10216 </capabilityfield>
10217 <capabilityfield id="can_maintain_original_method_order">
10218 <description>
10219 Can return methods in the order they occur in the class file
10220 </description>
10221 </capabilityfield>
10222 <capabilityfield id="can_generate_single_step_events">
10223 <description>
10224 Can get <eventlink id="SingleStep">single step</eventlink> events
10225 </description>
10226 </capabilityfield>
10227 <capabilityfield id="can_generate_exception_events">
10228 <description>
10229 Can get <eventlink id="Exception">exception thrown</eventlink> and
10230 <eventlink id="ExceptionCatch">exception catch</eventlink> events
10231 </description>
10232 </capabilityfield>
10233 <capabilityfield id="can_generate_frame_pop_events">
10234 <description>
10235 Can <functionlink id="NotifyFramePop">set</functionlink> and thus get
10236 <eventlink id="FramePop"></eventlink> events
10237 </description>
10238 </capabilityfield>
10239 <capabilityfield id="can_generate_breakpoint_events">
10240 <description>
10241 Can <functionlink id="SetBreakpoint">set</functionlink> and thus get
10242 <eventlink id="Breakpoint"></eventlink> events
10243 </description>
10244 </capabilityfield>
10245 <capabilityfield id="can_suspend">
10246 <description>
10247 Can suspend and resume threads
10248 </description>
10249 </capabilityfield>
10250 <capabilityfield id="can_redefine_any_class">
10251 <description>
10252 <functionlink id="RedefineClasses"/> can be called on any modifiable class.
10253 See <functionlink id="IsModifiableClass"/>.
10254 (<fieldlink id="can_redefine_classes" struct="jvmtiCapabilities"/>
10255 must also be set)
10256 </description>
10257 </capabilityfield>
10258 <capabilityfield id="can_get_current_thread_cpu_time">
10259 <description>
10260 Can <functionlink id="GetCurrentThreadCpuTime">get</functionlink>
10261 current thread CPU time
10262 </description>
10263 </capabilityfield>
10264 <capabilityfield id="can_get_thread_cpu_time">
10265 <description>
10266 Can <functionlink id="GetThreadCpuTime">get</functionlink>
10267 thread CPU time
10268 </description>
10269 </capabilityfield>
10270 <capabilityfield id="can_generate_method_entry_events"
10271 disp1="can_generate" disp2="_method_entry_events"
10272 >
10273 <description>
10274 Can generate method entry events on entering a method
10275 </description>
10276 </capabilityfield>
10277 <capabilityfield id="can_generate_method_exit_events"
10278 disp1="can_generate" disp2="_method_exit_events"
10279 >
10280 <description>
10281 Can generate method exit events on leaving a method
10282 </description>
10283 </capabilityfield>
10284 <capabilityfield id="can_generate_all_class_hook_events"
10285 disp1="can_generate" disp2="_all_class_hook_events"
10286 >
10287 <description>
10288 Can generate ClassFileLoadHook events for every loaded class.
10289 </description>
10290 </capabilityfield>
10291 <capabilityfield id="can_generate_compiled_method_load_events"
10292 disp1="can_generate" disp2="_compiled_method_load_events"
10293 >
10294 <description>
10295 Can generate events when a method is compiled or unloaded
10296 </description>
10297 </capabilityfield>
10298 <capabilityfield id="can_generate_monitor_events"
10299 disp1="can_generate" disp2="_monitor_events"
10300 >
10301 <description>
10302 Can generate events on monitor activity
10303 </description>
10304 </capabilityfield>
10305 <capabilityfield id="can_generate_vm_object_alloc_events"
10306 disp1="can_generate" disp2="_vm_object_alloc_events"
10307 >
10308 <description>
10309 Can generate events on VM allocation of an object
10310 </description>
10311 </capabilityfield>
10312 <capabilityfield id="can_generate_native_method_bind_events"
10313 disp1="can_generate" disp2="_native_method_bind_events"
10314 >
10315 <description>
10316 Can generate events when a native method is bound to its
10317 implementation
10318 </description>
10319 </capabilityfield>
10320 <capabilityfield id="can_generate_garbage_collection_events"
10321 disp1="can_generate" disp2="_garbage_collection_events"
10322 >
10323 <description>
10324 Can generate events when garbage collection begins or ends
10325 </description>
10326 </capabilityfield>
10327 <capabilityfield id="can_generate_object_free_events"
10328 disp1="can_generate" disp2="_object_free_events"
10329 >
10330 <description>
10331 Can generate events when the garbage collector frees an object
10332 </description>
10333 </capabilityfield>
10334 <capabilityfield id="can_force_early_return" since="1.1">
10335 <description>
10336 Can return early from a method, as described in the
10337 <internallink id="ForceEarlyReturn">Force Early Return category</internallink>.
10338 </description>
10339 </capabilityfield>
10340 <capabilityfield id="can_get_owned_monitor_stack_depth_info" since="1.1">
10341 <description>
10342 Can get information about owned monitors with stack depth -
10343 <functionlink id="GetOwnedMonitorStackDepthInfo"></functionlink>
10344 </description>
10345 </capabilityfield>
10346 <capabilityfield id="can_get_constant_pool" since="1.1">
10347 <description>
10348 Can get the constant pool of a class -
10349 <functionlink id="GetConstantPool"></functionlink>
10350 </description>
10351 </capabilityfield>
10352 <capabilityfield id="can_set_native_method_prefix" since="1.1">
10353 <description>
10354 Can set prefix to be applied when native method cannot be resolved -
10355 <functionlink id="SetNativeMethodPrefix"/> and
10356 <functionlink id="SetNativeMethodPrefixes"/>
10357 </description>
10358 </capabilityfield>
10359 <capabilityfield id="can_retransform_classes" since="1.1">
10360 <description>
10361 Can retransform classes with <functionlink id="RetransformClasses"/>.
10362 In addition to the restrictions imposed by the specific
10363 implementation on this capability (see the
10364 <internallink id="capability">Capability</internallink> section),
10365 this capability must be set before the
10366 <eventlink id="ClassFileLoadHook"/> event is enabled for the
10367 first time in this environment.
10368 An environment that possesses this capability at the time that
10369 <code>ClassFileLoadHook</code> is enabled for the first time is
10370 said to be <i>retransformation capable</i>.
10371 An environment that does not possess this capability at the time that
10372 <code>ClassFileLoadHook</code> is enabled for the first time is
10373 said to be <i>retransformation incapable</i>.
10374 </description>
10375 </capabilityfield>
10376 <capabilityfield id="can_retransform_any_class" since="1.1">
10377 <description>
10378 <functionlink id="RetransformClasses"/> can be called on any modifiable class.
10379 See <functionlink id="IsModifiableClass"/>.
10380 (<fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/>
10381 must also be set)
10382 </description>
10383 </capabilityfield>
10384 <capabilityfield id="can_generate_resource_exhaustion_heap_events" since="1.1">
10385 <description>
10386 Can generate events when the VM is unable to allocate memory from
10387 the <tm>Java</tm> platform heap.
10388 See <eventlink id="ResourceExhausted"/>.
10389 </description>
10390 </capabilityfield>
10391 <capabilityfield id="can_generate_resource_exhaustion_threads_events" since="1.1">
10392 <description>
10393 Can generate events when the VM is unable to create a thread.
10394 See <eventlink id="ResourceExhausted"/>.
10395 </description>
10396 </capabilityfield>
10397 <capabilityfield id="can_generate_early_vmstart" since="9">
10398 <description>
10399 Can generate the <code>VMStart</code> event early.
10400 See <eventlink id="VMStart"/>.
10401 </description>
10402 </capabilityfield>
10403 <capabilityfield id="can_generate_early_class_hook_events" since="9">
10404 <description>
10405 Can generate the <eventlink id="ClassFileLoadHook"/> events
10406 in the primordial phase. If this capability and
10407 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events">
10408 <code>can_generate_all_class_hook_events</code></internallink>
10409 are enabled then the <eventlink id="ClassFileLoadHook"/> events
10410 can be posted for classes loaded in the primordial phase.
10411 See <eventlink id="ClassFileLoadHook"/>.
10412 </description>
10413 </capabilityfield>
10414 <capabilityfield id="can_generate_sampled_object_alloc_events" since="11">
10415 <description>
10416 Can generate sampled allocation events.
10417 If this capability is enabled then the heap sampling method
10418 <functionlink id="SetHeapSamplingInterval"></functionlink> can be
10419 called and <eventlink id="SampledObjectAlloc"></eventlink> events can be generated.
10420 </description>
10421 </capabilityfield>
10422 </capabilitiestypedef>
10423
10424 <function id="GetPotentialCapabilities" jkernel="yes" phase="onload" num="140">
10425 <synopsis>Get Potential Capabilities</synopsis>
10426 <description>
10427 Returns via <paramlink id="capabilities_ptr"></paramlink> the <jvmti/>
10428 features that can potentially be possessed by this environment
10429 at this time.
10430 The returned capabilities differ from the complete set of capabilities
10431 implemented by the VM in two cases: another environment possesses
10432 capabilities that can only be possessed by one environment, or the
10433 current <functionlink id="GetPhase">phase</functionlink> is live,
10434 and certain capabilities can only be added during the <code>OnLoad</code> phase.
10435 The <functionlink id="AddCapabilities"></functionlink> function
10436 may be used to set any or all or these capabilities.
10437 Currently possessed capabilities are included.
10438 <p/>
10439 Typically this function is used in the <code>OnLoad</code> function.
10440 Some virtual machines may allow a limited set of capabilities to be
10441 added in the live phase.
10442 In this case, the set of potentially available capabilities
10443 will likely differ from the <code>OnLoad</code> phase set.
10444 <p/>
10445 See the
10446 <internallink id="capabilityExamples">Capability Examples</internallink>.
10447 </description>
10448 <origin>new</origin>
10449 <capabilities>
10450 </capabilities>
10451 <parameters>
10452 <param id="capabilities_ptr">
10453 <outptr><struct>jvmtiCapabilities</struct></outptr>
10454 <description>
10455 On return, points to the <jvmti/> capabilities that may be added.
10456 </description>
10457 </param>
10458 </parameters>
10459 <errors>
10460 </errors>
10461 </function>
10462
10463 <elide>
10464 <function id="EstimateCostOfCapabilities" phase="onload" num="141">
10465 <synopsis>Estimate Cost Of Capabilities</synopsis>
10466 <description>
10467 <issue>There is strong opposition to this function. The concern is
10468 that it would be difficult or impossible to provide meaningful
10469 numbers, as the amount of impact is conditional on many factors
10470 that a single number could not represent. There is doubt that
10471 conditional implementations would be used or are even a good idea.
10472 The thought is that release documentation for the implementation
10473 would be the best means of exposing this information.
10474 Unless new arguments are presented, I intend to remove this
10475 function in the next revision.
10476 </issue>
10477 <p/>
10478 Return via the <paramlink id="time_impact_ptr"></paramlink> and
10479 <paramlink id="space_impact_ptr"></paramlink> an estimate of the impact
10480 of adding the capabilities pointed to by
10481 <paramlink id="capabilities_ptr"></paramlink>.
10482 The returned estimates are in percentage of additional overhead, thus
10483 a time impact of 100 mean the application might run
10484 at half the speed.
10485 The estimates are very rough approximations and are not guaranteed.
10486 Note also, that the estimates are of the impact of having the
10487 capability available--when and if it is used the impact may be
10488 much greater.
10489 Estimates can be for a single capability or for a set of
10490 capabilities. Note that the costs are not necessarily additive,
10491 adding support for one capability might make another available
10492 for free or conversely having two capabilities at once may
10493 have multiplicative impact.
10494 Estimates are relative to the current set of capabilities -
10495 that is, how much more impact given the currently possessed capabilities.
10496 <p/>
10497 Typically this function is used in the OnLoad function,
10498 some virtual machines may allow a limited set of capabilities to be
10499 added in the live phase.
10500 In this case, the set of potentially available capabilities
10501 will likely differ from the OnLoad phase set.
10502 <p/>
10503 See the
10504 <internallink id="capabilityExamples">Capability Examples</internallink>.
10505 </description>
10506 <origin>new</origin>
10507 <capabilities>
10508 </capabilities>
10509 <parameters>
10510 <param id="capabilities_ptr">
10511 <inptr><struct>jvmtiCapabilities</struct></inptr>
10512 <description>
10513 points to the <jvmti/> capabilities to evaluate.
10514 </description>
10515 </param>
10516 <param id="time_impact_ptr">
10517 <outptr><jint/></outptr>
10518 <description>
10519 On return, points to the estimated percentage increase in
10520 run time if this capability was added.
10521 </description>
10522 </param>
10523 <param id="space_impact_ptr">
10524 <outptr><jint/></outptr>
10525 <description>
10526 On return, points to the estimated percentage increase in
10527 memory space used if this capability was added.
10528 </description>
10529 </param>
10530 </parameters>
10531 <errors>
10532 <error id="JVMTI_ERROR_NOT_AVAILABLE">
10533 The desired capabilities are not even potentially available.
10534 </error>
10535 </errors>
10536 </function>
10537 </elide>
10538
10539 <function id="AddCapabilities" jkernel="yes" phase="onload" num="142">
10540 <synopsis>Add Capabilities</synopsis>
10541 <description>
10542 Set new capabilities by adding the capabilities
10543 whose values are set to one (<code>1</code>) in
10544 <code>*</code><paramlink id="capabilities_ptr"></paramlink>.
10545 All previous capabilities are retained.
10546 Typically this function is used in the <code>OnLoad</code> function.
10547 Some virtual machines may allow a limited set of capabilities to be
10548 added in the live phase.
10549 <p/>
10550 See the
10551 <internallink id="capabilityExamples">Capability Examples</internallink>.
10552 </description>
10553 <origin>new</origin>
10554 <capabilities>
10555 </capabilities>
10556 <parameters>
10557 <param id="capabilities_ptr">
10558 <inptr><struct>jvmtiCapabilities</struct></inptr>
10559 <description>
10560 Points to the <jvmti/> capabilities to add.
10561 </description>
10562 </param>
10563 </parameters>
10564 <errors>
10565 <error id="JVMTI_ERROR_NOT_AVAILABLE">
10566 The desired capabilities are not even potentially available.
10567 </error>
10568 </errors>
10569 </function>
10570
10571
10572 <function id="RelinquishCapabilities" phase="onload" num="143">
10573 <synopsis>Relinquish Capabilities</synopsis>
10574 <description>
10575 Relinquish the capabilities
10576 whose values are set to one (<code>1</code>) in
10577 <code>*</code><paramlink id="capabilities_ptr"></paramlink>.
10578 Some implementations may allow only one environment to have a capability
10579 (see the <internallink id="capability">capability introduction</internallink>).
10580 This function releases capabilities
10581 so that they may be used by other agents.
10582 All other capabilities are retained.
10583 The capability will no longer be present in <functionlink id="GetCapabilities"></functionlink>.
10584 Attempting to relinquish a capability that the agent does not possess is not an error.
10585 <issue>
10586 It is possible for the agent to be actively using capabilities
10587 which are being relinquished. For example, a thread is currently
10588 suspended and can_suspend is being relinquished or an event is currently
10589 enabled and can_generate_whatever is being relinquished.
10590 There are three possible ways we could spec this:
10591 <ul>
10592 <li>relinquish automatically releases them</li>
10593 <li>relinquish checks and returns some error code if held</li>
10594 <li>it is the agent's responsibility and it is not checked</li>
10595 </ul>
10596 One of these should be chosen.
10597 </issue>
10598 </description>
10599 <origin>new</origin>
10600 <capabilities>
10601 </capabilities>
10602 <parameters>
10603 <param id="capabilities_ptr">
10604 <inptr><struct>jvmtiCapabilities</struct></inptr>
10605 <description>
10606 Points to the <jvmti/> capabilities to relinquish.
10607 </description>
10608 </param>
10609 </parameters>
10610 <errors>
10611 </errors>
10612 </function>
10613
10614
10615
10616 <function id="GetCapabilities" jkernel="yes" phase="any" num="89">
10617 <synopsis>Get Capabilities</synopsis>
10618 <description>
10619 Returns via <paramlink id="capabilities_ptr"></paramlink> the optional <jvmti/>
10620 features which this environment currently possesses.
10621 Each possessed capability is indicated by a one (<code>1</code>) in the
10622 corresponding field of the <internallink id="jvmtiCapabilities">capabilities
10623 structure</internallink>.
10624 An environment does not possess a capability unless it has been successfully added with
10625 <functionlink id="AddCapabilities"/>.
10626 An environment only loses possession of a capability if it has been relinquished with
10627 <functionlink id="RelinquishCapabilities"/>. Thus, this function returns the net result
10628 of the <code>AddCapabilities</code> and <code>RelinquishCapabilities</code> calls which
10629 have been made.
10630 <p/>
10631 See the
10632 <internallink id="capabilityExamples">Capability Examples</internallink>.
10633 </description>
10634 <origin>jvmdiClone</origin>
10635 <capabilities>
10636 </capabilities>
10637 <parameters>
10638 <param id="capabilities_ptr">
10639 <outptr><struct>jvmtiCapabilities</struct></outptr>
10640 <description>
10641 On return, points to the <jvmti/> capabilities.
10642 </description>
10643 </param>
10644 </parameters>
10645 <errors>
10646 </errors>
10647 </function>
10648
10649 </category>
10650
10651
10652 <category id="timers" label="Timers">
10653
10654 <intro>
10655 These functions provide timing information.
10656 The resolution at which the time is updated is not specified.
10657 They provides nanosecond precision, but not necessarily nanosecond accuracy.
10658 Details about the timers, such as their maximum values, can be accessed with
10659 the timer information functions.
10660 </intro>
10661
10662 <typedef id="jvmtiTimerInfo" label="Timer Info">
10663 <description>
10664 The information function for each timer returns this data structure.
10665 </description>
10666 <field id="max_value">
10667 <jlong/>
10668 <description>
10669 The maximum value the timer can reach.
10670 After this value is reached the timer wraps back to zero.
10671 This is an unsigned value. If tested or printed as a jlong (signed value)
10672 it may appear to be a negative number.
10673 </description>
10674 </field>
10675 <field id="may_skip_forward">
10676 <jboolean/>
10677 <description>
10678 If true, the timer can be externally adjusted and as a result skip forward.
10679 If false, the timer value will never increase faster than real time.
10680 </description>
10681 </field>
10682 <field id="may_skip_backward">
10683 <jboolean/>
10684 <description>
10685 If true, the timer can be externally adjusted and as a result skip backward.
10686 If false, the timer value will be monotonically increasing.
10687 </description>
10688 </field>
10689 <field id="kind">
10690 <enum>jvmtiTimerKind</enum>
10691 <description>
10692 The kind of timer.
10693 On a platform that does not distinguish between user and system time, <datalink
10694 id="JVMTI_TIMER_TOTAL_CPU"><code>JVMTI_TIMER_TOTAL_CPU</code></datalink>
10695 is returned.
10696 </description>
10697 </field>
10698 <field id="reserved1">
10699 <jlong/>
10700 <description>
10701 Reserved for future use.
10702 </description>
10703 </field>
10704 <field id="reserved2">
10705 <jlong/>
10706 <description>
10707 Reserved for future use.
10708 </description>
10709 </field>
10710 </typedef>
10711
10712 <intro>
10713 Where the timer kind is --
10714
10715 <constants id="jvmtiTimerKind" label="Timer Kinds" kind="enum">
10716 <constant id="JVMTI_TIMER_USER_CPU" num="30">
10717 CPU time that a thread is in user mode.
10718 </constant>
10719 <constant id="JVMTI_TIMER_TOTAL_CPU" num="31">
10720 CPU time that a thread is in user or system mode.
10721 </constant>
10722 <constant id="JVMTI_TIMER_ELAPSED" num="32">
10723 Elapsed time.
10724 </constant>
10725 </constants>
10726 </intro>
10727
10728 <function id="GetCurrentThreadCpuTimerInfo" callbacksafe="safe" impl="innative notrace" phase="start" num="134">
10729 <synopsis>Get Current Thread CPU Timer Information</synopsis>
10730 <description>
10731 Get information about the
10732 <functionlink id="GetCurrentThreadCpuTime"/> timer.
10733 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10734 are filled in with details about the timer.
10735 This information is specific to the platform and the implementation of
10736 <functionlink id="GetCurrentThreadCpuTime"/> and thus
10737 does not vary by thread nor does it vary
10738 during a particular invocation of the VM.
10739 <p/>
10740 Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/>
10741 and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values
10742 returned by <code>GetCurrentThreadCpuTimerInfo</code>
10743 and <functionlink id="GetThreadCpuTimerInfo"/>
10744 may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information.
10745 </description>
10746 <origin>new</origin>
10747 <capabilities>
10748 <required id="can_get_current_thread_cpu_time">
10749 Can get current thread CPU time.
10750 </required>
10751 </capabilities>
10752 <parameters>
10753 <param id="info_ptr">
10754 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10755 <description>
10756 On return, filled with information describing the time
10757 returned by <functionlink id="GetCurrentThreadCpuTime"/>.
10758 </description>
10759 </param>
10760 </parameters>
10761 <errors>
10762 </errors>
10763 </function>
10764
10765 <function id="GetCurrentThreadCpuTime" callbacksafe="safe" impl="innative notrace" phase="start" num="135">
10766 <synopsis>Get Current Thread CPU Time</synopsis>
10767 <description>
10768 Return the CPU time utilized by the current thread.
10769 <p/>
10770 Note that the <functionlink id="GetThreadCpuTime"/>
10771 function provides CPU time for any thread, including
10772 the current thread. <code>GetCurrentThreadCpuTime</code>
10773 exists to support platforms which cannot
10774 supply CPU time for threads other than the current
10775 thread or which have more accurate information for
10776 the current thread (see
10777 <functionlink id="GetCurrentThreadCpuTimerInfo"/> vs
10778 <functionlink id="GetThreadCpuTimerInfo"/>).
10779 On many platforms this call will be equivalent to:
10780 <example>
10781 GetThreadCpuTime(env, NULL, nanos_ptr)
10782 </example>
10783 </description>
10784 <origin>new</origin>
10785 <capabilities>
10786 <required id="can_get_current_thread_cpu_time">
10787 Can get current thread CPU time.
10788 <p/>
10789 If this capability is enabled after threads have started,
10790 the implementation may choose any time up
10791 to and including the time that the capability is enabled
10792 as the point where CPU time collection starts.
10793 <p/>
10794 This capability must be potentially available on any
10795 platform where
10796 <internallink id="jvmtiCapabilities.can_get_thread_cpu_time"><code>can_get_thread_cpu_time</code></internallink>
10797 is potentially available.
10798 </required>
10799 </capabilities>
10800 <parameters>
10801 <param id="nanos_ptr">
10802 <outptr><jlong/></outptr>
10803 <description>
10804 On return, points to the CPU time used by this thread
10805 in nanoseconds.
10806 This is an unsigned value. If tested or printed as a jlong (signed value)
10807 it may appear to be a negative number.
10808 </description>
10809 </param>
10810 </parameters>
10811 <errors>
10812 </errors>
10813 </function>
10814
10815 <function id="GetThreadCpuTimerInfo" num="136">
10816 <synopsis>Get Thread CPU Timer Information</synopsis>
10817 <description>
10818 Get information about the
10819 <functionlink id="GetThreadCpuTime"/> timer.
10820 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10821 are filled in with details about the timer.
10822 This information is specific to the platform and the implementation of
10823 <functionlink id="GetThreadCpuTime"/> and thus
10824 does not vary by thread nor does it vary
10825 during a particular invocation of the VM.
10826 <p/>
10827 Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/>
10828 and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values
10829 returned by <functionlink id="GetCurrentThreadCpuTimerInfo"/>
10830 and <code>GetThreadCpuTimerInfo</code>
10831 may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information.
10832 </description>
10833 <origin>new</origin>
10834 <capabilities>
10835 <required id="can_get_thread_cpu_time">
10836 Can get thread CPU time.
10837 </required>
10838 </capabilities>
10839 <parameters>
10840 <param id="info_ptr">
10841 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10842 <description>
10843 On return, filled with information describing the time
10844 returned by <functionlink id="GetThreadCpuTime"/>.
10845 </description>
10846 </param>
10847 </parameters>
10848 <errors>
10849 </errors>
10850 </function>
10851
10852 <function id="GetThreadCpuTime" num="137">
10853 <synopsis>Get Thread CPU Time</synopsis>
10854 <description>
10855 Return the CPU time utilized by the specified thread.
10856 <p/>
10857 Get information about this timer with
10858 <functionlink id="GetThreadCpuTimerInfo"/>.
10859 </description>
10860 <origin>new</origin>
10861 <capabilities>
10862 <required id="can_get_thread_cpu_time">
10863 Can get thread CPU time.
10864 <p/>
10865 If this capability is enabled after threads have started,
10866 the implementation may choose any time up
10867 to and including the time that the capability is enabled
10868 as the point where CPU time collection starts.
10869 </required>
10870 </capabilities>
10871 <parameters>
10872 <param id="thread">
10873 <jthread null="current"/>
10874 <description>
10875 The thread to query.
10876 </description>
10877 </param>
10878 <param id="nanos_ptr">
10879 <outptr><jlong/></outptr>
10880 <description>
10881 On return, points to the CPU time used by the specified thread
10882 in nanoseconds.
10883 This is an unsigned value. If tested or printed as a jlong (signed value)
10884 it may appear to be a negative number.
10885 </description>
10886 </param>
10887 </parameters>
10888 <errors>
10889 </errors>
10890 </function>
10891
10892 <function id="GetTimerInfo" phase="any" callbacksafe="safe" num="138">
10893 <synopsis>Get Timer Information</synopsis>
10894 <description>
10895 Get information about the
10896 <functionlink id="GetTime"/> timer.
10897 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10898 are filled in with details about the timer.
10899 This information will not change during a particular invocation of the VM.
10900 </description>
10901 <origin>new</origin>
10902 <capabilities>
10903 </capabilities>
10904 <parameters>
10905 <param id="info_ptr">
10906 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10907 <description>
10908 On return, filled with information describing the time
10909 returned by <functionlink id="GetTime"/>.
10910 </description>
10911 </param>
10912 </parameters>
10913 <errors>
10914 </errors>
10915 </function>
10916
10917 <function id="GetTime" phase="any" callbacksafe="safe" num="139">
10918 <synopsis>Get Time</synopsis>
10919 <description>
10920 Return the current value of the system timer, in nanoseconds.
10921 <p/>
10922 The value returned represents nanoseconds since some fixed but
10923 arbitrary time (perhaps in the future, so values may be
10924 negative). This function provides nanosecond precision, but not
10925 necessarily nanosecond accuracy. No guarantees are made about
10926 how frequently values change.
10927 <p/>
10928 Get information about this timer with
10929 <functionlink id="GetTimerInfo"/>.
10930 </description>
10931 <origin>new</origin>
10932 <capabilities>
10933 </capabilities>
10934 <parameters>
10935 <param id="nanos_ptr">
10936 <outptr><jlong/></outptr>
10937 <description>
10938 On return, points to the time in nanoseconds.
10939 This is an unsigned value. If tested or printed as a jlong (signed value)
10940 it may appear to be a negative number.
10941 </description>
10942 </param>
10943 </parameters>
10944 <errors>
10945 </errors>
10946 </function>
10947
10948 <function id="GetAvailableProcessors" phase="any" num="144">
10949 <synopsis>Get Available Processors</synopsis>
10950 <description>
10951 Returns the number of processors available to the Java virtual machine.
10952 <p/>
10953 This value may change during a particular invocation of the virtual machine.
10954 Applications that are sensitive to the number of available processors should
10955 therefore occasionally poll this property.
10956 </description>
10957 <origin>new</origin>
10958 <capabilities>
10959 </capabilities>
10960 <parameters>
10961 <param id="processor_count_ptr">
10962 <outptr><jint/></outptr>
10963 <description>
10964 On return, points to the maximum number of processors available to the
10965 virtual machine; never smaller than one.
10966 </description>
10967 </param>
10968 </parameters>
10969 <errors>
10970 </errors>
10971 </function>
10972
10973 </category>
10974
10975
10976 <category id="classLoaderSearch" label="Class Loader Search">
10977
10978 <intro>
10979 These functions allow the agent to add to the locations that a class loader searches for a class.
10980 This is useful for installing instrumentation under the correct class loader.
10981 </intro>
10982
10983 <function id="AddToBootstrapClassLoaderSearch" jkernel="yes" phase="onload" num="149">
10984 <synopsis>Add To Bootstrap Class Loader Search</synopsis>
10985 <description>
10986 This function can be used to cause instrumentation classes to be defined by the
10987 bootstrap class loader. See <vmspec chapter="5.3.1"/>.
10988 After the bootstrap
10989 class loader unsuccessfully searches for a class, the specified platform-dependent
10990 search path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in
10991 the <paramlink id="segment"/>. This function may be called multiple times to add multiple segments,
10992 the segments will be searched in the order that this function was called.
10993 <p/>
10994 In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent
10995 search path segment to be searched after the bootstrap class loader unsuccessfully searches
10996 for a class. The segment is typically a directory or JAR file.
10997 <p/>
10998 In the live phase the <paramlink id="segment"/> may be used to specify any platform-dependent
10999 path to a <externallink id="jar/jar.html">
11000 JAR file</externallink>. The agent should take care that the JAR file does not
11001 contain any classes or resources other than those to be defined by the bootstrap
11002 class loader for the purposes of instrumentation.
11003 <p/>
11004 <vmspec/> specifies that a subsequent attempt to resolve a symbolic
11005 reference that the Java virtual machine has previously unsuccessfully attempted
11006 to resolve always fails with the same error that was thrown as a result of the
11007 initial resolution attempt. Consequently, if the JAR file contains an entry
11008 that corresponds to a class for which the Java virtual machine has
11009 unsuccessfully attempted to resolve a reference, then subsequent attempts to
11010 resolve that reference will fail with the same error as the initial attempt.
11011 </description>
11012 <origin>new</origin>
11013 <capabilities>
11014 </capabilities>
11015 <parameters>
11016 <param id="segment">
11017 <inbuf><char/></inbuf>
11018 <description>
11019 The platform-dependent search path segment, encoded as a
11020 <internallink id="mUTF">modified UTF-8</internallink> string.
11021 </description>
11022 </param>
11023 </parameters>
11024 <errors>
11025 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
11026 <paramlink id="segment"/> is an invalid path. In the live phase, anything other than an
11027 existing JAR file is an invalid path.
11028 </error>
11029 </errors>
11030 </function>
11031
11032 <function id="AddToSystemClassLoaderSearch" jkernel="yes" phase="onload" num="151" since="1.1">
11033 <synopsis>Add To System Class Loader Search</synopsis>
11034 <description>
11035 This function can be used to cause instrumentation classes to be
11036 defined by the system class loader. See <vmspec chapter="5.3.2"/>.
11037 After the class loader unsuccessfully searches for a class, the specified platform-dependent search
11038 path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in the
11039 <paramlink id="segment"/>. This function may be called multiple times to add multiple segments, the
11040 segments will be searched in the order that this function was called.
11041 <p/>
11042 In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent
11043 search path segment to be searched after the system class loader unsuccessfully searches
11044 for a class. The segment is typically a directory or JAR file.
11045 <p/>
11046 In the live phase the <paramlink id="segment"/> is a platform-dependent path to a
11047 <externallink id="jar/jar.html">JAR file</externallink> to be
11048 searched after the system class loader unsuccessfully searches for a class. The agent should
11049 take care that the JAR file does not contain any classes or resources other than those to be
11050 defined by the system class loader for the purposes of instrumentation.
11051 <p/>
11052 In the live phase the system class loader supports adding a JAR file to be searched if
11053 the system class loader implements a method name <code>appendToClassPathForInstrumentation</code>
11054 which takes a single parameter of type <code>java.lang.String</code>. The method is not required
11055 to have <code>public</code> access.
11056 <p/>
11057 <vmspec/> specifies that a subsequent attempt to resolve a symbolic
11058 reference that the Java virtual machine has previously unsuccessfully attempted
11059 to resolve always fails with the same error that was thrown as a result of the
11060 initial resolution attempt. Consequently, if the JAR file contains an entry
11061 that corresponds to a class for which the Java virtual machine has
11062 unsuccessfully attempted to resolve a reference, then subsequent attempts to
11063 resolve that reference will fail with the same error as the initial attempt.
11064 </description>
11065 <origin>new</origin>
11066 <capabilities>
11067 </capabilities>
11068 <parameters>
11069 <param id="segment">
11070 <inbuf><char/></inbuf>
11071 <description>
11072 The platform-dependent search path segment, encoded as a
11073 <internallink id="mUTF">modified UTF-8</internallink> string.
11074 </description>
11075 </param>
11076 </parameters>
11077 <errors>
11078 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
11079 <paramlink id="segment"/> is an invalid path. In the live phase, anything other than an
11080 existing JAR file is an invalid path.
11081 </error>
11082 <error id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED">
11083 Operation not supported by the system class loader.
11084 </error>
11085 </errors>
11086 </function>
11087
11088 </category>
11089
11090
11091 <category id="props" label="System Properties">
11092
11093 <intro>
11094 These functions get and set system properties.
11095 </intro>
11096
11097 <function id="GetSystemProperties" phase="onload" num="130">
11098 <synopsis>Get System Properties</synopsis>
11099 <description>
11100 The list of VM system property keys which may be used with
11101 <functionlink id="GetSystemProperty"/> is returned.
11102 It is strongly recommended that virtual machines provide the
11103 following property keys:
11104 <ul>
11105 <li><code>java.vm.vendor</code></li>
11106 <li><code>java.vm.version</code></li>
11107 <li><code>java.vm.name</code></li>
11108 <li><code>java.vm.info</code></li>
11109 <li><code>java.library.path</code></li>
11110 <li><code>java.class.path</code></li>
11111 </ul>
11112 Provides access to system properties defined by and used
11113 by the VM.
11114 Properties set on the command-line are included.
11115 This allows getting and setting of these properties
11116 before the VM even begins executing bytecodes.
11117 Since this is a VM view of system properties, the set of available
11118 properties will usually be different than that
11119 in <code>java.lang.System.getProperties</code>.
11120 JNI method invocation may be used to access
11121 <code>java.lang.System.getProperties</code>.
11122 <p/>
11123 The set of properties may grow during execution.
11124 </description>
11125 <origin>new</origin>
11126 <capabilities>
11127 </capabilities>
11128 <parameters>
11129 <param id="count_ptr">
11130 <outptr><jint/></outptr>
11131 <description>
11132 On return, points to the number of property keys returned.
11133 </description>
11134 </param>
11135 <param id="property_ptr">
11136 <allocallocbuf outcount="count_ptr"><char/></allocallocbuf>
11137 <description>
11138 On return, points to an array of property keys, encoded as
11139 <internallink id="mUTF">modified UTF-8</internallink> strings.
11140 </description>
11141 </param>
11142 </parameters>
11143 <errors>
11144 </errors>
11145 </function>
11146
11147 <function id="GetSystemProperty" phase="onload" num="131">
11148 <synopsis>Get System Property</synopsis>
11149 <description>
11150 Return a VM system property value given the property key.
11151 <p/>
11152 The function <functionlink id="GetSystemProperties"/>
11153 returns the set of property keys which may be used.
11154 The properties which can be retrieved may grow during
11155 execution.
11156 <p/>
11157 Since this is a VM view of system properties, the values
11158 of properties may differ from that returned by
11159 <code>java.lang.System.getProperty(String)</code>.
11160 A typical VM might copy the values of the VM system
11161 properties into the <code>Properties</code> held by
11162 <code>java.lang.System</code> during the initialization
11163 of that class. Thereafter any changes to the VM system
11164 properties (with <functionlink id="SetSystemProperty"/>)
11165 or the <code>java.lang.System</code> system properties
11166 (with <code>java.lang.System.setProperty(String,String)</code>)
11167 would cause the values to diverge.
11168 JNI method invocation may be used to access
11169 <code>java.lang.System.getProperty(String)</code>.
11170 </description>
11171 <origin>new</origin>
11172 <capabilities>
11173 </capabilities>
11174 <parameters>
11175 <param id="property">
11176 <inbuf><char/></inbuf>
11177 <description>
11178 The key of the property to retrieve, encoded as a
11179 <internallink id="mUTF">modified UTF-8</internallink> string.
11180 </description>
11181 </param>
11182 <param id="value_ptr">
11183 <allocbuf><char/></allocbuf>
11184 <description>
11185 On return, points to the property value, encoded as a
11186 <internallink id="mUTF">modified UTF-8</internallink> string.
11187 </description>
11188 </param>
11189 </parameters>
11190 <errors>
11191 <error id="JVMTI_ERROR_NOT_AVAILABLE">
11192 This property is not available.
11193 Use <functionlink id="GetSystemProperties"/> to find available properties.
11194 </error>
11195 </errors>
11196 </function>
11197
11198 <function id="SetSystemProperty" phase="onloadOnly" num="132">
11199 <synopsis>Set System Property</synopsis>
11200 <description>
11201 Set a VM system property value.
11202 <p/>
11203 The function <functionlink id="GetSystemProperties"/>
11204 returns the set of property keys, some of these may be settable.
11205 See <functionlink id="GetSystemProperty"/>.
11206 </description>
11207 <origin>new</origin>
11208 <capabilities>
11209 </capabilities>
11210 <parameters>
11211 <param id="property">
11212 <inbuf><char/></inbuf>
11213 <description>
11214 The key of the property, encoded as a
11215 <internallink id="mUTF">modified UTF-8</internallink> string.
11216 </description>
11217 </param>
11218 <param id="value_ptr">
11219 <inbuf>
11220 <char/>
11221 <nullok>
11222 do not set the value, but return <errorlink id="JVMTI_ERROR_NOT_AVAILABLE"/>
11223 if the property is not writeable
11224 </nullok>
11225 </inbuf>
11226 <description>
11227 The property value to set, encoded as a
11228 <internallink id="mUTF">modified UTF-8</internallink> string.
11229 </description>
11230 </param>
11231 </parameters>
11232 <errors>
11233 <error id="JVMTI_ERROR_NOT_AVAILABLE">
11234 This property is not available or is not writeable.
11235 </error>
11236 </errors>
11237 </function>
11238
11239 </category>
11240
11241 <category id="general" label="General">
11242
11243 <intro>
11244 </intro>
11245
11246 <function id="GetPhase" jkernel="yes" phase="any" num="133">
11247 <synopsis>Get Phase</synopsis>
11248 <description>
11249 Return the current phase of VM execution.
11250 The phases proceed in sequence:
11251 <constants id="jvmtiPhase" label="Phases of execution" kind="enum">
11252 <constant id="JVMTI_PHASE_ONLOAD" num="1">
11253 <code>OnLoad</code> phase: while in the
11254 <internallink id="onload"><code>Agent_OnLoad</code></internallink>
11255 or, for statically linked agents, the <internallink id="onload">
11256 <code>Agent_OnLoad_<agent-lib-name>
11257 </code></internallink> function.
11258 </constant>
11259 <constant id="JVMTI_PHASE_PRIMORDIAL" num="2">
11260 Primordial phase: between return from <code>Agent_OnLoad</code>
11261 or <code>Agent_OnLoad_<agent-lib-name></code> and the
11262 <code>VMStart</code> event.
11263 </constant>
11264 <constant id="JVMTI_PHASE_START" num="6">
11265 Start phase: when the <eventlink id="VMStart"><code>VMStart</code></eventlink> event
11266 is sent and until the <code>VMInit</code> event is sent.
11267 </constant>
11268 <constant id="JVMTI_PHASE_LIVE" num="4">
11269 Live phase: when the <eventlink id="VMInit"><code>VMInit</code></eventlink> event is sent
11270 and until the <eventlink id="VMDeath"></eventlink> event returns.
11271 </constant>
11272 <constant id="JVMTI_PHASE_DEAD" num="8">
11273 Dead phase: after the <eventlink id="VMDeath"></eventlink> event returns or after
11274 start-up failure.
11275 </constant>
11276 </constants>
11277 In the case of start-up failure the VM will proceed directly to the dead
11278 phase skipping intermediate phases and neither a <code>VMInit</code> nor
11279 <code>VMDeath</code> event will be sent.
11280 <p/>
11281 Most <jvmti/> functions operate only in the live phase.
11282 The following functions operate in either the <code>OnLoad</code> or live phases:
11283 <functionphaselist phase="onload"/>
11284 The following functions operate in only the <code>OnLoad</code> phase:
11285 <functionphaselist phase="onloadOnly"/>
11286 The following functions operate in the start or live phases:
11287 <functionphaselist phase="start"/>
11288 The following functions operate in any phase:
11289 <functionphaselist phase="any"/>
11290 JNI functions (except the Invocation API) must only be used in the start or live phases.
11291 <p/>
11292 Most <jvmti/> events are sent only in the live phase.
11293 The following events operate in others phases:
11294 <eventphaselist phase="start"/>
11295 <eventphaselist phase="any"/>
11296 </description>
11297 <origin>new</origin>
11298 <capabilities>
11299 </capabilities>
11300 <parameters>
11301 <param id="phase_ptr">
11302 <outptr><enum>jvmtiPhase</enum></outptr>
11303 <description>
11304 On return, points to the phase.
11305 </description>
11306 </param>
11307 </parameters>
11308 <errors>
11309 </errors>
11310 </function>
11311
11312 <function id="DisposeEnvironment" jkernel="yes" phase="any" num="127">
11313 <synopsis>Dispose Environment</synopsis>
11314 <description>
11315 Shutdown a <jvmti/> connection created with JNI <code>GetEnv</code>
11316 (see <internallink id="environments"><jvmti/> Environments</internallink>).
11317 Dispose of any resources held by the environment.
11318 <issue>
11319 What resources are reclaimed? What is undone?
11320 Breakpoints,watchpoints removed?
11321 </issue>
11322 Threads suspended by this environment are not resumed by this call,
11323 this must be done explicitly by the agent.
11324 Memory allocated by this environment via calls to <jvmti/> functions
11325 is not released, this can be done explicitly by the agent
11326 by calling <functionlink id="Deallocate"/>.
11327 Raw monitors created by this environment are not destroyed,
11328 this can be done explicitly by the agent
11329 by calling <functionlink id="DestroyRawMonitor"/>.
11330 The state of threads waiting on raw monitors created by this environment
11331 are not affected.
11332 <p/>
11333 Any <functionlink id="SetNativeMethodPrefix">native method
11334 prefixes</functionlink> for this environment will be unset;
11335 the agent must remove any prefixed native methods before
11336 dispose is called.
11337 <p/>
11338 Any <internallink id="capability">capabilities</internallink>
11339 held by this environment are relinquished.
11340 <p/>
11341 Events enabled by this environment will no longer be sent, however
11342 event handlers currently running will continue to run. Caution must
11343 be exercised in the design of event handlers whose environment may
11344 be disposed and thus become invalid during their execution.
11345 <p/>
11346 This environment may not be used after this call.
11347 This call returns to the caller.
11348 </description>
11349 <origin>new</origin>
11350 <capabilities>
11351 </capabilities>
11352 <parameters>
11353 </parameters>
11354 <errors>
11355 </errors>
11356 </function>
11357
11358 <function id="SetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="148">
11359 <synopsis>Set Environment Local Storage</synopsis>
11360 <description>
11361 The VM stores a pointer value associated with each environment.
11362 This pointer value is called <i>environment-local storage</i>.
11363 This value is <code>NULL</code> unless set with this function.
11364 Agents can allocate memory in which they store environment specific
11365 information. By setting environment-local storage it can then be
11366 accessed with
11367 <functionlink id="GetEnvironmentLocalStorage"></functionlink>.
11368 <p/>
11369 Called by the agent to set the value of the <jvmti/>
11370 environment-local storage. <jvmti/> supplies to the agent a pointer-size
11371 environment-local storage that can be used to record per-environment
11372 information.
11373 </description>
11374 <origin>new</origin>
11375 <capabilities>
11376 </capabilities>
11377 <parameters>
11378 <param id="data">
11379 <inbuf>
11380 <void/>
11381 <nullok>value is set to <code>NULL</code></nullok>
11382 </inbuf>
11383 <description>
11384 The value to be entered into the environment-local storage.
11385 </description>
11386 </param>
11387 </parameters>
11388 <errors>
11389 </errors>
11390 </function>
11391
11392 <function id="GetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="147">
11393 <synopsis>Get Environment Local Storage</synopsis>
11394 <description>
11395 Called by the agent to get the value of the <jvmti/> environment-local
11396 storage.
11397 </description>
11398 <origin>new</origin>
11399 <capabilities>
11400 </capabilities>
11401 <parameters>
11402 <param id="data_ptr">
11403 <agentbuf><void/></agentbuf>
11404 <description>
11405 Pointer through which the value of the environment local
11406 storage is returned.
11407 If environment-local storage has not been set with
11408 <functionlink id="SetEnvironmentLocalStorage"></functionlink> returned
11409 pointer is <code>NULL</code>.
11410 </description>
11411 </param>
11412 </parameters>
11413 <errors>
11414 </errors>
11415 </function>
11416
11417 <function id="GetVersionNumber" jkernel="yes" phase="any" num="88">
11418 <synopsis>Get Version Number</synopsis>
11419 <description>
11420 Return the <jvmti/> version via <code>version_ptr</code>.
11421 The return value is the version identifier.
11422 The version identifier includes major, minor and micro
11423 version as well as the interface type.
11424 <constants id="jvmtiVersionInterfaceTypes" label="Version Interface Types" kind="bits">
11425 <constant id="JVMTI_VERSION_INTERFACE_JNI" num="0x00000000">
11426 Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for JNI.
11427 </constant>
11428 <constant id="JVMTI_VERSION_INTERFACE_JVMTI" num="0x30000000">
11429 Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for <jvmti/>.
11430 </constant>
11431 </constants>
11432 <constants id="jvmtiVersionMasks" label="Version Masks" kind="bits">
11433 <constant id="JVMTI_VERSION_MASK_INTERFACE_TYPE" num="0x70000000">
11434 Mask to extract interface type.
11435 The value of the version returned by this function masked with
11436 <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> is always
11437 <code>JVMTI_VERSION_INTERFACE_JVMTI</code>
11438 since this is a <jvmti/> function.
11439 </constant>
11440 <constant id="JVMTI_VERSION_MASK_MAJOR" num="0x0FFF0000">
11441 Mask to extract major version number.
11442 </constant>
11443 <constant id="JVMTI_VERSION_MASK_MINOR" num="0x0000FF00">
11444 Mask to extract minor version number.
11445 </constant>
11446 <constant id="JVMTI_VERSION_MASK_MICRO" num="0x000000FF">
11447 Mask to extract micro version number.
11448 </constant>
11449 </constants>
11450 <constants id="jvmtiVersionShifts" label="Version Shifts" kind="bits">
11451 <constant id="JVMTI_VERSION_SHIFT_MAJOR" num="16">
11452 Shift to extract major version number.
11453 </constant>
11454 <constant id="JVMTI_VERSION_SHIFT_MINOR" num="8">
11455 Shift to extract minor version number.
11456 </constant>
11457 <constant id="JVMTI_VERSION_SHIFT_MICRO" num="0">
11458 Shift to extract micro version number.
11459 </constant>
11460 </constants>
11461 </description>
11462 <origin>jvmdi</origin>
11463 <capabilities>
11464 </capabilities>
11465 <parameters>
11466 <param id="version_ptr">
11467 <outptr><jint/></outptr>
11468 <description>
11469 On return, points to the <jvmti/> version.
11470 </description>
11471 </param>
11472 </parameters>
11473 <errors>
11474 </errors>
11475 </function>
11476
11477
11478 <function id="GetErrorName" phase="any" num="128">
11479 <synopsis>Get Error Name</synopsis>
11480 <description>
11481 Return the symbolic name for an
11482 <internallink id="ErrorSection">error code</internallink>.
11483 <p/>
11484 For example
11485 <code>GetErrorName(env, JVMTI_ERROR_NONE, &err_name)</code>
11486 would return in <code>err_name</code> the string
11487 <code>"JVMTI_ERROR_NONE"</code>.
11488 </description>
11489 <origin>new</origin>
11490 <capabilities>
11491 </capabilities>
11492 <parameters>
11493 <param id="error">
11494 <enum>jvmtiError</enum>
11495 <description>
11496 The error code.
11497 </description>
11498 </param>
11499 <param id="name_ptr">
11500 <allocbuf><char/></allocbuf>
11501 <description>
11502 On return, points to the error name.
11503 The name is encoded as a
11504 <internallink id="mUTF">modified UTF-8</internallink> string,
11505 but is restricted to the ASCII subset.
11506 </description>
11507 </param>
11508 </parameters>
11509 <errors>
11510 </errors>
11511 </function>
11512
11513 <function id="SetVerboseFlag" phase="any" num="150">
11514 <synopsis>Set Verbose Flag</synopsis>
11515 <description>
11516 <constants id="jvmtiVerboseFlag" label="Verbose Flag Enumeration" kind="enum">
11517 <constant id="JVMTI_VERBOSE_OTHER" num="0">
11518 Verbose output other than the below.
11519 </constant>
11520 <constant id="JVMTI_VERBOSE_GC" num="1">
11521 Verbose garbage collector output, like that specified with <code>-verbose:gc</code>.
11522 </constant>
11523 <constant id="JVMTI_VERBOSE_CLASS" num="2">
11524 Verbose class loading output, like that specified with <code>-verbose:class</code>.
11525 </constant>
11526 <constant id="JVMTI_VERBOSE_JNI" num="4">
11527 Verbose JNI output, like that specified with <code>-verbose:jni</code>.
11528 </constant>
11529 </constants>
11530 Control verbose output.
11531 This is the output which typically is sent to <code>stderr</code>.
11532 </description>
11533 <origin>new</origin>
11534 <capabilities>
11535 </capabilities>
11536 <parameters>
11537 <param id="flag">
11538 <enum>jvmtiVerboseFlag</enum>
11539 <description>
11540 Which verbose flag to set.
11541 </description>
11542 </param>
11543 <param id="value">
11544 <jboolean/>
11545 <description>
11546 New value of the flag.
11547 </description>
11548 </param>
11549 </parameters>
11550 <errors>
11551 </errors>
11552 </function>
11553
11554
11555 <function id="GetJLocationFormat" phase="any" num="129">
11556 <synopsis>Get JLocation Format</synopsis>
11557 <description>
11558 Although the greatest functionality is achieved with location information
11559 referencing the virtual machine bytecode index, the definition of
11560 <code>jlocation</code> has intentionally been left unconstrained to allow VM
11561 implementations that do not have this information.
11562 <p/>
11563 This function describes the representation of <code>jlocation</code> used in this VM.
11564 If the returned format is <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>,
11565 <code>jlocation</code>s can
11566 be used as in indices into the array returned by
11567 <functionlink id="GetBytecodes"></functionlink>.
11568 <constants id="jvmtiJlocationFormat" label="JLocation Format Enumeration" kind="enum">
11569 <constant id="JVMTI_JLOCATION_JVMBCI" num="1">
11570 <code>jlocation</code> values represent virtual machine
11571 bytecode indices--that is, offsets into the
11572 virtual machine code for a method.
11573 </constant>
11574 <constant id="JVMTI_JLOCATION_MACHINEPC" num="2">
11575 <code>jlocation</code> values represent native machine
11576 program counter values.
11577 </constant>
11578 <constant id="JVMTI_JLOCATION_OTHER" num="0">
11579 <code>jlocation</code> values have some other representation.
11580 </constant>
11581 </constants>
11582 </description>
11583 <origin>new</origin>
11584 <capabilities>
11585 </capabilities>
11586 <parameters>
11587 <param id="format_ptr">
11588 <outptr><enum>jvmtiJlocationFormat</enum></outptr>
11589 <description>
11590 On return, points to the format identifier for <code>jlocation</code> values.
11591 </description>
11592 </param>
11593 </parameters>
11594 <errors>
11595 </errors>
11596 </function>
11597
11598 </category>
11599
11600 <category id="heap_monitoring" label="Heap Monitoring">
11601 <function id="SetHeapSamplingInterval" phase="onload" num="156" since="11">
11602 <synopsis>Set Heap Sampling Interval</synopsis>
11603 <description>
11604 Generate a <eventlink id="SampledObjectAlloc"/> event when objects are allocated.
11605 Each thread keeps a counter of bytes allocated. The event will only be generated
11606 when that counter exceeds an average of <paramlink id="sampling_interval"></paramlink>
11607 since the last sample.
11608 <p/>
11609 Setting <paramlink id="sampling_interval"></paramlink> to 0 will cause an event to be
11610 generated by each allocation supported by the system once the new interval is taken into account.
11611 <p/>
11612 Note that updating the new sampling interval might take various number of allocations
11613 to provoke internal data structure updates. Therefore it is important to
11614 consider the sampling interval as an average. This includes the interval 0, where events
11615 might not be generated straight away for each allocation.
11616 </description>
11617 <origin>new</origin>
11618 <capabilities>
11619 <required id="can_generate_sampled_object_alloc_events"></required>
11620 </capabilities>
11621 <parameters>
11622 <param id="sampling_interval">
11623 <jint/>
11624 <description>
11625 The sampling interval in bytes. The sampler uses a statistical approach to
11626 generate an event, on average, once for every <paramlink id="sampling_interval"/> bytes of
11627 memory allocated by a given thread.
11628 <p/>
11629 Once the new sampling interval is taken into account, 0 as a sampling interval will generate
11630 a sample for every allocation.
11631 <p/>
11632 Note: The overhead of this feature is directly correlated with the sampling interval.
11633 A high sampling interval, such as 1024 bytes, will incur a high overhead.
11634 A lower interval, such as 1024KB, will have a much lower overhead. Sampling should only
11635 be used with an understanding that it may impact performance.
11636 </description>
11637 </param>
11638 </parameters>
11639 <errors>
11640 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
11641 <paramlink id="sampling_interval"></paramlink> is less than zero.
11642 </error>
11643 </errors>
11644 </function>
11645 </category>
11646
11647 </functionsection>
11648
11649 <errorsection label="Error Reference">
11650 <intro>
11651 Every <jvmti/> function returns a <b><code>jvmtiError</code></b> error code.
11652 <p/>
11653 It is the responsibility of the agent to call <jvmti/> functions with
11654 valid parameters and in the proper context (calling thread is attached,
11655 phase is correct, etc.).
11656 Detecting some error conditions may be difficult, inefficient, or
11657 impossible for an implementation.
11658 The errors listed in
11659 <internallink id="reqerrors">Function Specific Required Errors</internallink>
11660 must be detected by the implementation.
11661 All other errors represent the recommended response to the error
11662 condition.
11663 </intro>
11664
11665 <errorcategory id="universal-error" label="Universal Errors">
11666 <intro>
11667 The following errors may be returned by any function
11668 </intro>
11669
11670 <errorid id="JVMTI_ERROR_NONE" num="0">
11671 No error has occurred. This is the error code that is returned
11672 on successful completion of the function.
11673 </errorid>
11674 <errorid id="JVMTI_ERROR_NULL_POINTER" num="100">
11675 Pointer is unexpectedly <code>NULL</code>.
11676 </errorid>
11677 <errorid id="JVMTI_ERROR_OUT_OF_MEMORY" num="110">
11678 The function attempted to allocate memory and no more memory was
11679 available for allocation.
11680 </errorid>
11681 <errorid id="JVMTI_ERROR_ACCESS_DENIED" num="111">
11682 The desired functionality has not been enabled in this virtual machine.
11683 </errorid>
11684 <errorid id="JVMTI_ERROR_UNATTACHED_THREAD" num="115">
11685 The thread being used to call this function is not attached
11686 to the virtual machine. Calls must be made from attached threads.
11687 See <code>AttachCurrentThread</code> in the JNI invocation API.
11688 </errorid>
11689 <errorid id="JVMTI_ERROR_INVALID_ENVIRONMENT" num="116">
11690 The <jvmti/> environment provided is no longer connected or is
11691 not an environment.
11692 </errorid>
11693 <errorid id="JVMTI_ERROR_WRONG_PHASE" num="112">
11694 The desired functionality is not available in the current
11695 <functionlink id="GetPhase">phase</functionlink>.
11696 Always returned if the virtual machine has completed running.
11697 </errorid>
11698 <errorid id="JVMTI_ERROR_INTERNAL" num="113">
11699 An unexpected internal error has occurred.
11700 </errorid>
11701 </errorcategory>
11702
11703 <errorcategory id="reqerrors" label="Function Specific Required Errors">
11704 <intro>
11705 The following errors are returned by some <jvmti/> functions and must
11706 be returned by the implementation when the condition occurs.
11707 </intro>
11708
11709 <errorid id="JVMTI_ERROR_INVALID_PRIORITY" num="12">
11710 Invalid priority.
11711 </errorid>
11712 <errorid id="JVMTI_ERROR_THREAD_NOT_SUSPENDED" num="13">
11713 Thread was not suspended.
11714 </errorid>
11715 <errorid id="JVMTI_ERROR_THREAD_SUSPENDED" num="14">
11716 Thread already suspended.
11717 </errorid>
11718 <errorid id="JVMTI_ERROR_THREAD_NOT_ALIVE" num="15">
11719 This operation requires the thread to be alive--that is,
11720 it must be started and not yet have died.
11721 </errorid>
11722 <errorid id="JVMTI_ERROR_CLASS_NOT_PREPARED" num="22">
11723 The class has been loaded but not yet prepared.
11724 </errorid>
11725 <errorid id="JVMTI_ERROR_NO_MORE_FRAMES" num="31">
11726 There are no Java programming language or JNI stack frames at the specified depth.
11727 </errorid>
11728 <errorid id="JVMTI_ERROR_OPAQUE_FRAME" num="32">
11729 Information about the frame is not available (e.g. for native frames).
11730 </errorid>
11731 <errorid id="JVMTI_ERROR_DUPLICATE" num="40">
11732 Item already set.
11733 </errorid>
11734 <errorid id="JVMTI_ERROR_NOT_FOUND" num="41">
11735 Desired element (e.g. field or breakpoint) not found
11736 </errorid>
11737 <errorid id="JVMTI_ERROR_NOT_MONITOR_OWNER" num="51">
11738 This thread doesn't own the raw monitor.
11739 </errorid>
11740 <errorid id="JVMTI_ERROR_INTERRUPT" num="52">
11741 The call has been interrupted before completion.
11742 </errorid>
11743 <errorid id="JVMTI_ERROR_UNMODIFIABLE_CLASS" num="79">
11744 The class cannot be modified.
11745 </errorid>
11746 <errorid id="JVMTI_ERROR_UNMODIFIABLE_MODULE" num="80">
11747 The module cannot be modified.
11748 </errorid>
11749 <errorid id="JVMTI_ERROR_NOT_AVAILABLE" num="98">
11750 The functionality is not available in this virtual machine.
11751 </errorid>
11752 <errorid id="JVMTI_ERROR_ABSENT_INFORMATION" num="101">
11753 The requested information is not available.
11754 </errorid>
11755 <errorid id="JVMTI_ERROR_INVALID_EVENT_TYPE" num="102">
11756 The specified event type ID is not recognized.
11757 </errorid>
11758 <errorid id="JVMTI_ERROR_NATIVE_METHOD" num="104">
11759 The requested information is not available for native method.
11760 </errorid>
11761 <errorid id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED" num="106">
11762 The class loader does not support this operation.
11763 </errorid>
11764 </errorcategory>
11765
11766 <errorcategory id="function-specific-errors" label="Function Specific Agent Errors">
11767 <intro>
11768 The following errors are returned by some <jvmti/> functions.
11769 They are returned in the event of invalid parameters passed by the
11770 agent or usage in an invalid context.
11771 An implementation is not required to detect these errors.
11772 </intro>
11773
11774 <errorid id="JVMTI_ERROR_INVALID_THREAD" num="10">
11775 The passed thread is not a valid thread.
11776 </errorid>
11777 <errorid id="JVMTI_ERROR_INVALID_FIELDID" num="25">
11778 Invalid field.
11779 </errorid>
11780 <errorid id="JVMTI_ERROR_INVALID_MODULE" num="26">
11781 Invalid module.
11782 </errorid>
11783 <errorid id="JVMTI_ERROR_INVALID_METHODID" num="23">
11784 Invalid method.
11785 </errorid>
11786 <errorid id="JVMTI_ERROR_INVALID_LOCATION" num="24">
11787 Invalid location.
11788 </errorid>
11789 <errorid id="JVMTI_ERROR_INVALID_OBJECT" num="20">
11790 Invalid object.
11791 </errorid>
11792 <errorid id="JVMTI_ERROR_INVALID_CLASS" num="21">
11793 Invalid class.
11794 </errorid>
11795 <errorid id="JVMTI_ERROR_TYPE_MISMATCH" num="34">
11796 The variable is not an appropriate type for the function used.
11797 </errorid>
11798 <errorid id="JVMTI_ERROR_INVALID_SLOT" num="35">
11799 Invalid slot.
11800 </errorid>
11801 <errorid id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY" num="99">
11802 The capability being used is false in this environment.
11803 </errorid>
11804 <errorid id="JVMTI_ERROR_INVALID_THREAD_GROUP" num="11">
11805 Thread group invalid.
11806 </errorid>
11807 <errorid id="JVMTI_ERROR_INVALID_MONITOR" num="50">
11808 Invalid raw monitor.
11809 </errorid>
11810 <errorid id="JVMTI_ERROR_ILLEGAL_ARGUMENT" num="103">
11811 Illegal argument.
11812 </errorid>
11813 <errorid id="JVMTI_ERROR_INVALID_TYPESTATE" num="65">
11814 The state of the thread has been modified, and is now inconsistent.
11815 </errorid>
11816 <errorid id="JVMTI_ERROR_UNSUPPORTED_VERSION" num="68">
11817 A new class file has a version number not supported by this VM.
11818 </errorid>
11819 <errorid id="JVMTI_ERROR_INVALID_CLASS_FORMAT" num="60">
11820 A new class file is malformed (the VM would return a <code>ClassFormatError</code>).
11821 </errorid>
11822 <errorid id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION" num="61">
11823 The new class file definitions would lead to a circular
11824 definition (the VM would return a <code>ClassCircularityError</code>).
11825 </errorid>
11826 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED" num="63">
11827 A new class file would require adding a method.
11828 </errorid>
11829 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED" num="64">
11830 A new class version changes a field.
11831 </errorid>
11832 <errorid id="JVMTI_ERROR_FAILS_VERIFICATION" num="62">
11833 The class bytes fail verification.
11834 </errorid>
11835 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED" num="66">
11836 A direct superclass is different for the new class
11837 version, or the set of directly implemented
11838 interfaces is different.
11839 </errorid>
11840 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED" num="67">
11841 A new class version does not declare a method
11842 declared in the old class version.
11843 </errorid>
11844 <errorid id="JVMTI_ERROR_NAMES_DONT_MATCH" num="69">
11845 The class name defined in the new class file is
11846 different from the name in the old class object.
11847 </errorid>
11848 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED" num="70">
11849 A new class version has different modifiers.
11850 </errorid>
11851 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED" num="71">
11852 A method in the new class version has different modifiers
11853 than its counterpart in the old class version.
11854 </errorid>
11855 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_ATTRIBUTE_CHANGED" num="72">
11856 A new class version has unsupported differences in class attributes.
11857 </errorid>
11858 </errorcategory>
11859 </errorsection>
11860
11861 <eventsection label="Events">
11862 <intro label="Handling Events" id="eventIntro">
11863 Agents can be informed of many events that occur in application
11864 programs.
11865 <p/>
11866 To handle events, designate a set of callback functions with
11867 <functionlink id="SetEventCallbacks"></functionlink>.
11868 For each event the corresponding callback function will be
11869 called.
11870 Arguments to the callback function provide additional
11871 information about the event.
11872 <p/>
11873 The callback function is usually called from within an application
11874 thread. The <jvmti/> implementation does not
11875 queue events in any way. This means
11876 that event callback functions must be written
11877 carefully. Here are some general guidelines. See
11878 the individual event descriptions for further
11879 suggestions.
11880 <p/>
11881 <ul>
11882 <li>Any exception thrown during the execution of an event callback can
11883 overwrite any current pending exception in the current application thread.
11884 Care must be taken to preserve a pending exception
11885 when an event callback makes a JNI call that might generate an exception.
11886 </li>
11887 <li>Event callback functions must be re-entrant. The <jvmti/> implementation does
11888 not queue events. If an agent needs to process events one at a time, it
11889 can use a raw monitor inside the
11890 event callback functions to serialize event processing.
11891 </li>
11892 <li>Event callback functions that execute JNI's FindClass function to load
11893 classes need to note that FindClass locates the class loader associated
11894 with the current native method. For the purposes of class loading, an
11895 event callback that includes a JNI environment as a parameter to the
11896 callback will treated as if it is a native call, where the native method
11897 is in the class of the event thread's current frame.
11898 </li>
11899 </ul>
11900 <p/>
11901 Some <jvmti/> events identify objects with JNI references.
11902 All references
11903 in <jvmti/> events are JNI local references and will become invalid
11904 after the event callback returns.
11905 Unless stated otherwise, memory referenced by pointers sent in event
11906 callbacks may not be referenced after the event callback returns.
11907 <p/>
11908 Except where stated otherwise, events are delivered on the thread
11909 that caused the event.
11910 Events are sent at the time they occur.
11911 The specification for each event includes the set of
11912 <functionlink id="GetPhase">phases</functionlink> in which it can be sent;
11913 if an event triggering activity occurs during another phase, no event
11914 is sent.
11915 <p/>
11916 A thread that generates an event does not change its execution status
11917 (for example, the event does not cause the thread to be suspended).
11918 If an agent wishes the event to result in suspension, then the agent
11919 is responsible for explicitly suspending the thread with
11920 <functionlink id="SuspendThread"></functionlink>.
11921 <p/>
11922 If an event is enabled in multiple environments, the event will be sent
11923 to each agent in the order that the environments were created.
11924 </intro>
11925
11926 <intro label="Enabling Events" id="enablingevents">
11927 All events are initially disabled. In order to receive any
11928 event:
11929 <ul>
11930 <li>
11931 If the event requires a capability, that capability must
11932 be added with
11933 <functionlink id="AddCapabilities"></functionlink>.
11934 </li>
11935 <li>
11936 A callback for the event must be set with
11937 <functionlink id="SetEventCallbacks"></functionlink>.
11938 </li>
11939 <li>
11940 The event must be enabled with
11941 <functionlink id="SetEventNotificationMode"></functionlink>.
11942 </li>
11943 </ul>
11944 </intro>
11945
11946 <intro label="Multiple Co-located Events" id="eventorder">
11947 In many situations it is possible for multiple events to occur
11948 at the same location in one thread. When this happens, all the events
11949 are reported through the event callbacks in the order specified in this section.
11950 <p/>
11951 If the current location is at the entry point of a method, the
11952 <eventlink id="MethodEntry"></eventlink> event is reported before
11953 any other event at the current location in the same thread.
11954 <p/>
11955 If an exception catch has been detected at the current location,
11956 either because it is the beginning of a catch clause or a native method
11957 that cleared a pending exception has returned, the
11958 <code>exceptionCatch</code> event is reported before
11959 any other event at the current location in the same thread.
11960 <p/>
11961 If a <code>singleStep</code> event or
11962 <code>breakpoint</code> event is triggered at the
11963 current location, the event is defined to occur
11964 immediately before the code at the current location is executed.
11965 These events are reported before any events which are triggered
11966 by the execution of code at the current location in the same
11967 thread (specifically:
11968 <code>exception</code>,
11969 <code>fieldAccess</code>, and
11970 <code>fieldModification</code>).
11971 If both a step and breakpoint event are triggered for the same thread and
11972 location, the step event is reported before the breakpoint event.
11973 <p/>
11974 If the current location is the exit point of a method (that is, the last
11975 location before returning to the caller), the
11976 <eventlink id="MethodExit"></eventlink> event and
11977 the <eventlink id="FramePop"></eventlink> event (if requested)
11978 are reported after all other events at the current location in the same
11979 thread. There is no specified ordering of these two events
11980 with respect to each other.
11981 <p/>
11982 Co-located events can be triggered during the processing of some other
11983 event by the agent at the same location in the same thread.
11984 If such an event, of type <i>y</i>, is triggered during the processing of
11985 an event of type <i>x</i>, and if <i>x</i>
11986 precedes <i>y</i> in the ordering specified above, the co-located event
11987 <i>y</i> is reported for the current thread and location. If <i>x</i> does not precede
11988 <i>y</i>, <i>y</i> is not reported for the current thread and location.
11989 For example, if a breakpoint is set at the current location
11990 during the processing of <eventlink id="SingleStep"></eventlink>,
11991 that breakpoint will be reported before the thread moves off the current
11992 location.
11993 <p/>The following events are never considered to be co-located with
11994 other events.
11995 <ul>
11996 <li><eventlink id="VMStart"></eventlink></li>
11997 <li><eventlink id="VMInit"></eventlink></li>
11998 <li><eventlink id="VMDeath"></eventlink></li>
11999 <li><eventlink id="ThreadStart"></eventlink></li>
12000 <li><eventlink id="ThreadEnd"></eventlink></li>
12001 <li><eventlink id="ClassLoad"></eventlink></li>
12002 <li><eventlink id="ClassPrepare"></eventlink></li>
12003 </ul>
12004 </intro>
12005
12006 <intro label="Event Callbacks" id="jvmtiEventCallbacks">
12007 The event callback structure below is used to specify the handler function
12008 for events. It is set with the
12009 <functionlink id="SetEventCallbacks"></functionlink> function.
12010 </intro>
12011
12012 <event label="Single Step"
12013 id="SingleStep" const="JVMTI_EVENT_SINGLE_STEP" filtered="thread" num="60">
12014 <description>
12015 Single step events allow the agent to trace thread execution
12016 at the finest granularity allowed by the VM. A single step event is
12017 generated whenever a thread reaches a new location.
12018 Typically, single step events represent the completion of one VM
12019 instruction as defined in <vmspec/>. However, some implementations
12020 may define locations differently. In any case the
12021 <code>method</code> and <code>location</code>
12022 parameters uniquely identify the current location and allow
12023 the mapping to source file and line number when that information is
12024 available.
12025 <p/>
12026 No single step events are generated from within native methods.
12027 </description>
12028 <origin>jvmdi</origin>
12029 <capabilities>
12030 <required id="can_generate_single_step_events"></required>
12031 </capabilities>
12032 <parameters>
12033 <param id="jni_env">
12034 <outptr>
12035 <struct>JNIEnv</struct>
12036 </outptr>
12037 <description>
12038 The JNI environment of the event (current) thread
12039 </description>
12040 </param>
12041 <param id="thread">
12042 <jthread/>
12043 <description>
12044 Thread about to execution a new instruction
12045 </description>
12046 </param>
12047 <param id="klass">
12048 <jclass method="method"/>
12049 <description>
12050 Class of the method about to execute a new instruction
12051 </description>
12052 </param>
12053 <param id="method">
12054 <jmethodID class="klass"/>
12055 <description>
12056 Method about to execute a new instruction
12057 </description>
12058 </param>
12059 <param id="location">
12060 <jlocation/>
12061 <description>
12062 Location of the new instruction
12063 </description>
12064 </param>
12065 </parameters>
12066 </event>
12067
12068 <event label="Breakpoint"
12069 id="Breakpoint" const="JVMTI_EVENT_BREAKPOINT" filtered="thread" num="62">
12070 <description>
12071 Breakpoint events are generated whenever a thread reaches a location
12072 designated as a breakpoint with <functionlink id="SetBreakpoint"></functionlink>.
12073 The <code>method</code> and <code>location</code>
12074 parameters uniquely identify the current location and allow
12075 the mapping to source file and line number when that information is
12076 available.
12077 </description>
12078 <origin>jvmdi</origin>
12079 <capabilities>
12080 <required id="can_generate_breakpoint_events"></required>
12081 </capabilities>
12082 <parameters>
12083 <param id="jni_env">
12084 <outptr>
12085 <struct>JNIEnv</struct>
12086 </outptr>
12087 <description>
12088 The JNI environment of the event (current) thread.
12089 </description>
12090 </param>
12091 <param id="thread">
12092 <jthread/>
12093 <description>
12094 Thread that hit the breakpoint
12095 </description>
12096 </param>
12097 <param id="klass">
12098 <jclass method="method"/>
12099 <description>
12100 Class of the method that hit the breakpoint
12101 </description>
12102 </param>
12103 <param id="method">
12104 <jmethodID class="klass"/>
12105 <description>
12106 Method that hit the breakpoint
12107 </description>
12108 </param>
12109 <param id="location">
12110 <jlocation/>
12111 <description>
12112 location of the breakpoint
12113 </description>
12114 </param>
12115 </parameters>
12116 </event>
12117
12118 <event label="Field Access"
12119 id="FieldAccess" const="JVMTI_EVENT_FIELD_ACCESS" filtered="thread" num="63">
12120 <description>
12121 Field access events are generated whenever a thread accesses
12122 a field that was designated as a watchpoint
12123 with <functionlink id="SetFieldAccessWatch"></functionlink>.
12124 The <code>method</code> and <code>location</code>
12125 parameters uniquely identify the current location and allow
12126 the mapping to source file and line number when that information is
12127 available.
12128 </description>
12129 <origin>jvmdi</origin>
12130 <capabilities>
12131 <required id="can_generate_field_access_events"></required>
12132 </capabilities>
12133 <parameters>
12134 <param id="jni_env">
12135 <outptr>
12136 <struct>JNIEnv</struct>
12137 </outptr>
12138 <description>
12139 The JNI environment of the event (current) thread
12140 </description>
12141 </param>
12142 <param id="thread">
12143 <jthread/>
12144 <description>
12145 Thread accessing the field
12146 </description>
12147 </param>
12148 <param id="klass">
12149 <jclass method="method"/>
12150 <description>
12151 Class of the method where the access is occurring
12152 </description>
12153 </param>
12154 <param id="method">
12155 <jmethodID class="klass"/>
12156 <description>
12157 Method where the access is occurring
12158 </description>
12159 </param>
12160 <param id="location">
12161 <jlocation/>
12162 <description>
12163 Location where the access is occurring
12164 </description>
12165 </param>
12166 <param id="field_klass">
12167 <jclass field="field"/>
12168 <description>
12169 Class of the field being accessed
12170 </description>
12171 </param>
12172 <param id="object">
12173 <jobject/>
12174 <description>
12175 Object with the field being accessed if the field is an
12176 instance field; <code>NULL</code> otherwise
12177 </description>
12178 </param>
12179 <param id="field">
12180 <jfieldID class="field_klass"/>
12181 <description>
12182 Field being accessed
12183 </description>
12184 </param>
12185 </parameters>
12186 </event>
12187
12188 <event label="Field Modification"
12189 id="FieldModification" const="JVMTI_EVENT_FIELD_MODIFICATION" filtered="thread" num="64">
12190 <description>
12191 Field modification events are generated whenever a thread modifies
12192 a field that was designated as a watchpoint
12193 with <functionlink id="SetFieldModificationWatch"></functionlink>.
12194 The <code>method</code> and <code>location</code>
12195 parameters uniquely identify the current location and allow
12196 the mapping to source file and line number when that information is
12197 available.
12198 </description>
12199 <origin>jvmdi</origin>
12200 <capabilities>
12201 <required id="can_generate_field_modification_events"></required>
12202 </capabilities>
12203 <parameters>
12204 <param id="jni_env">
12205 <outptr>
12206 <struct>JNIEnv</struct>
12207 </outptr>
12208 <description>
12209 The JNI environment of the event (current) thread
12210 </description>
12211 </param>
12212 <param id="thread">
12213 <jthread/>
12214 <description>
12215 Thread modifying the field
12216 </description>
12217 </param>
12218 <param id="klass">
12219 <jclass method="method"/>
12220 <description>
12221 Class of the method where the modification is occurring
12222 </description>
12223 </param>
12224 <param id="method">
12225 <jmethodID class="klass"/>
12226 <description>
12227 Method where the modification is occurring
12228 </description>
12229 </param>
12230 <param id="location">
12231 <jlocation/>
12232 <description>
12233 Location where the modification is occurring
12234 </description>
12235 </param>
12236 <param id="field_klass">
12237 <jclass field="field"/>
12238 <description>
12239 Class of the field being modified
12240 </description>
12241 </param>
12242 <param id="object">
12243 <jobject/>
12244 <description>
12245 Object with the field being modified if the field is an
12246 instance field; <code>NULL</code> otherwise
12247 </description>
12248 </param>
12249 <param id="field">
12250 <jfieldID class="field_klass"/>
12251 <description>
12252 Field being modified
12253 </description>
12254 </param>
12255 <param id="signature_type">
12256 <char/>
12257 <description>
12258 Signature type of the new value
12259 </description>
12260 </param>
12261 <param id="new_value">
12262 <jvalue/>
12263 <description>
12264 The new value
12265 </description>
12266 </param>
12267 </parameters>
12268 </event>
12269
12270 <event label="Frame Pop"
12271 id="FramePop" const="JVMTI_EVENT_FRAME_POP" filtered="thread" num="61">
12272 <description>
12273 Frame pop events are generated upon exit from a single method
12274 in a single frame as specified
12275 in a call to <functionlink id="NotifyFramePop"></functionlink>.
12276 This is true whether termination is caused by
12277 executing its return instruction
12278 or by throwing an exception to its caller
12279 (see <paramlink id="was_popped_by_exception"></paramlink>).
12280 However, frame pops caused by the <functionlink id="PopFrame"/>
12281 function are not reported.
12282 <p/>
12283 The location reported by <functionlink id="GetFrameLocation"></functionlink>
12284 identifies the executable location in the returning method,
12285 immediately prior to the return.
12286 </description>
12287 <origin>jvmdi</origin>
12288 <capabilities>
12289 <required id="can_generate_frame_pop_events"></required>
12290 </capabilities>
12291 <parameters>
12292 <param id="jni_env">
12293 <outptr>
12294 <struct>JNIEnv</struct>
12295 </outptr>
12296 <description>
12297 The JNI environment of the event (current) thread
12298 </description>
12299 </param>
12300 <param id="thread">
12301 <jthread/>
12302 <description>
12303 Thread that is popping the frame
12304 </description>
12305 </param>
12306 <param id="klass">
12307 <jclass method="method"/>
12308 <description>
12309 Class of the method being popped
12310 </description>
12311 </param>
12312 <param id="method">
12313 <jmethodID class="klass"/>
12314 <description>
12315 Method being popped
12316 </description>
12317 </param>
12318 <param id="was_popped_by_exception">
12319 <jboolean/>
12320 <description>
12321 True if frame was popped by a thrown exception.
12322 False if method exited through its return instruction.
12323 </description>
12324 </param>
12325 </parameters>
12326 </event>
12327
12328 <event label="Method Entry"
12329 id="MethodEntry" const="JVMTI_EVENT_METHOD_ENTRY" filtered="thread" num="65">
12330 <description>
12331 Method entry events are generated upon entry of Java
12332 programming language methods (including native methods).
12333 <p/>
12334 The location reported by <functionlink id="GetFrameLocation"></functionlink>
12335 identifies the initial executable location in
12336 the method.
12337 <p/>
12338 Enabling method
12339 entry or exit events will significantly degrade performance on many platforms and is thus
12340 not advised for performance critical usage (such as profiling).
12341 <internallink id="bci">Bytecode instrumentation</internallink> should be
12342 used in these cases.
12343 </description>
12344 <origin>jvmdi</origin>
12345 <capabilities>
12346 <required id="can_generate_method_entry_events"></required>
12347 </capabilities>
12348 <parameters>
12349 <param id="jni_env">
12350 <outptr>
12351 <struct>JNIEnv</struct>
12352 </outptr>
12353 <description>
12354 The JNI environment of the event (current) thread
12355 </description>
12356 </param>
12357 <param id="thread">
12358 <jthread/>
12359 <description>
12360 Thread entering the method
12361 </description>
12362 </param>
12363 <param id="klass">
12364 <jclass method="method"/>
12365 <description>
12366 Class of the method being entered
12367 </description>
12368 </param>
12369 <param id="method">
12370 <jmethodID class="klass"/>
12371 <description>
12372 Method being entered
12373 </description>
12374 </param>
12375 </parameters>
12376 </event>
12377
12378 <event label="Method Exit"
12379 id="MethodExit" const="JVMTI_EVENT_METHOD_EXIT" filtered="thread" num="66">
12380 <description>
12381 Method exit events are generated upon exit from Java
12382 programming language methods (including native methods).
12383 This is true whether termination is caused by
12384 executing its return instruction
12385 or by throwing an exception to its caller
12386 (see <paramlink id="was_popped_by_exception"></paramlink>).
12387 <p/>
12388 The <code>method</code> field uniquely identifies the
12389 method being entered or exited. The <code>frame</code> field provides
12390 access to the stack frame for the method.
12391 <p/>
12392 The location reported by <functionlink id="GetFrameLocation"></functionlink>
12393 identifies the executable location in the returning method
12394 immediately prior to the return.
12395 <p/>
12396 Enabling method
12397 entry or exit events will significantly degrade performance on many platforms and is thus
12398 not advised for performance critical usage (such as profiling).
12399 <internallink id="bci">Bytecode instrumentation</internallink> should be
12400 used in these cases.
12401 </description>
12402 <origin>jvmdi</origin>
12403 <capabilities>
12404 <required id="can_generate_method_exit_events"></required>
12405 </capabilities>
12406 <parameters>
12407 <param id="jni_env">
12408 <outptr>
12409 <struct>JNIEnv</struct>
12410 </outptr>
12411 <description>
12412 The JNI environment of the event (current) thread
12413 </description>
12414 </param>
12415 <param id="thread">
12416 <jthread/>
12417 <description>
12418 Thread exiting the method
12419 </description>
12420 </param>
12421 <param id="klass">
12422 <jclass method="method"/>
12423 <description>
12424 Class of the method being exited
12425 </description>
12426 </param>
12427 <param id="method">
12428 <jmethodID class="klass"/>
12429 <description>
12430 Method being exited
12431 </description>
12432 </param>
12433 <param id="was_popped_by_exception">
12434 <jboolean/>
12435 <description>
12436 True if frame was popped by a thrown exception.
12437 False if method exited through its return instruction.
12438 </description>
12439 </param>
12440 <param id="return_value">
12441 <jvalue/>
12442 <description>
12443 The return value of the method being exited.
12444 Undefined and should not be used if
12445 <paramlink id="was_popped_by_exception"></paramlink>
12446 is true.
12447 </description>
12448 </param>
12449 </parameters>
12450 </event>
12451
12452 <event label="Native Method Bind" phase="any"
12453 id="NativeMethodBind" const="JVMTI_EVENT_NATIVE_METHOD_BIND" num="67">
12454 <description>
12455 A Native Method Bind event is sent when a VM binds a
12456 Java programming language native method
12457 to the address of a function that implements the native method.
12458 This will occur when the native method is called for the first time
12459 and also occurs when the JNI function <code>RegisterNatives</code> is called.
12460 This event allows the bind to be redirected to an agent-specified
12461 proxy function.
12462 This event is not sent when the native method is unbound.
12463 Typically, this proxy function will need to be specific to a
12464 particular method or, to handle the general case, automatically
12465 generated assembly code, since after instrumentation code is
12466 executed the function at the original binding
12467 address will usually be invoked.
12468 The original binding can be restored or the redirection changed
12469 by use of the JNI function <code>RegisterNatives</code>.
12470 Some events may be sent during the primordial phase, JNI and
12471 most of <jvmti/> cannot be used at this time but the method and
12472 address can be saved for use later.
12473 </description>
12474 <origin>new</origin>
12475 <capabilities>
12476 <required id="can_generate_native_method_bind_events"></required>
12477 </capabilities>
12478 <parameters>
12479 <param id="jni_env">
12480 <outptr>
12481 <struct>JNIEnv</struct>
12482 </outptr>
12483 <description>
12484 The JNI environment of the event (current) thread
12485 Will be <code>NULL</code> if sent during the primordial
12486 <functionlink id="GetPhase">phase</functionlink>.
12487 </description>
12488 </param>
12489 <param id="thread">
12490 <jthread/>
12491 <description>
12492 Thread requesting the bind
12493 </description>
12494 </param>
12495 <param id="klass">
12496 <jclass method="method"/>
12497 <description>
12498 Class of the method being bound
12499 </description>
12500 </param>
12501 <param id="method">
12502 <jmethodID class="klass"/>
12503 <description>
12504 Native method being bound
12505 </description>
12506 </param>
12507 <param id="address">
12508 <outptr><void/></outptr>
12509 <description>
12510 The address the VM is about to bind to--that is, the
12511 address of the implementation of the native method
12512 </description>
12513 </param>
12514 <param id="new_address_ptr">
12515 <agentbuf><void/></agentbuf>
12516 <description>
12517 if the referenced address is changed (that is, if
12518 <code>*new_address_ptr</code> is set), the binding
12519 will instead be made to the supplied address.
12520 </description>
12521 </param>
12522 </parameters>
12523 </event>
12524
12525 <event label="Exception"
12526 id="Exception" const="JVMTI_EVENT_EXCEPTION" filtered="thread" num="58">
12527 <description>
12528 Exception events are generated whenever an exception is first detected
12529 in a Java programming language method.
12530 Where "exception" means any <code>java.lang.Throwable</code>.
12531 The exception may have been thrown by a Java programming language or native
12532 method, but in the case of native methods, the event is not generated
12533 until the exception is first seen by a Java programming language method. If an exception is
12534 set and cleared in a native method (and thus is never visible to Java programming language code),
12535 no exception event is generated.
12536 <p/>
12537 The <code>method</code> and <code>location</code>
12538 parameters uniquely identify the current location
12539 (where the exception was detected) and allow
12540 the mapping to source file and line number when that information is
12541 available. The <code>exception</code> field identifies the thrown
12542 exception object. The <code>catch_method</code>
12543 and <code>catch_location</code> identify the location of the catch clause,
12544 if any, that handles the thrown exception. If there is no such catch clause,
12545 each field is set to 0. There is no guarantee that the thread will ever
12546 reach this catch clause. If there are native methods on the call stack
12547 between the throw location and the catch clause, the exception may
12548 be reset by one of those native methods.
12549 Similarly, exceptions that are reported as uncaught (<code>catch_klass</code>
12550 et al. set to 0) may in fact be caught by native code.
12551 Agents can check for these occurrences by monitoring
12552 <eventlink id="ExceptionCatch"></eventlink> events.
12553 Note that finally clauses are implemented as catch and re-throw. Therefore they
12554 will be reported in the catch location.
12555 </description>
12556 <origin>jvmdi</origin>
12557 <capabilities>
12558 <required id="can_generate_exception_events"></required>
12559 </capabilities>
12560 <parameters>
12561 <param id="jni_env">
12562 <outptr>
12563 <struct>JNIEnv</struct>
12564 </outptr>
12565 <description>
12566 The JNI environment of the event (current) thread
12567 </description>
12568 </param>
12569 <param id="thread">
12570 <jthread/>
12571 <description>
12572 Thread generating the exception
12573 </description>
12574 </param>
12575 <param id="klass">
12576 <jclass method="method"/>
12577 <description>
12578 Class generating the exception
12579 </description>
12580 </param>
12581 <param id="method">
12582 <jmethodID class="klass"/>
12583 <description>
12584 Method generating the exception
12585 </description>
12586 </param>
12587 <param id="location">
12588 <jlocation/>
12589 <description>
12590 Location where exception occurred
12591 </description>
12592 </param>
12593 <param id="exception">
12594 <jobject/>
12595 <description>
12596 The exception being thrown
12597 </description>
12598 </param>
12599 <param id="catch_klass">
12600 <jclass method="catch_method"/>
12601 <description>
12602 Class that will catch the exception, or <code>NULL</code> if no known catch
12603 </description>
12604 </param>
12605 <param id="catch_method">
12606 <jmethodID class="catch_klass"/>
12607 <description>
12608 Method that will catch the exception, or <code>NULL</code> if no known catch
12609 </description>
12610 </param>
12611 <param id="catch_location">
12612 <jlocation/>
12613 <description>
12614 location which will catch the exception or zero if no known catch
12615 </description>
12616 </param>
12617 </parameters>
12618 </event>
12619
12620 <event label="Exception Catch"
12621 id="ExceptionCatch" const="JVMTI_EVENT_EXCEPTION_CATCH" filtered="thread" num="59">
12622 <description>
12623 Exception catch events are generated whenever a thrown exception is caught.
12624 Where "exception" means any <code>java.lang.Throwable</code>.
12625 If the exception is caught in a Java programming language method, the event is generated
12626 when the catch clause is reached. If the exception is caught in a native
12627 method, the event is generated as soon as control is returned to a Java programming language
12628 method. Exception catch events are generated for any exception for which
12629 a throw was detected in a Java programming language method.
12630 Note that finally clauses are implemented as catch and re-throw. Therefore they
12631 will generate exception catch events.
12632 <p/>
12633 The <code>method</code> and <code>location</code>
12634 parameters uniquely identify the current location
12635 and allow the mapping to source file and line number when that information is
12636 available. For exceptions caught in a Java programming language method, the
12637 <code>exception</code> object identifies the exception object. Exceptions
12638 caught in native methods are not necessarily available by the time the
12639 exception catch is reported, so the <code>exception</code> field is set
12640 to <code>NULL</code>.
12641 </description>
12642 <origin>jvmdi</origin>
12643 <capabilities>
12644 <required id="can_generate_exception_events"></required>
12645 </capabilities>
12646 <parameters>
12647 <param id="jni_env">
12648 <outptr>
12649 <struct>JNIEnv</struct>
12650 </outptr>
12651 <description>
12652 The JNI environment of the event (current) thread
12653 </description>
12654 </param>
12655 <param id="thread">
12656 <jthread/>
12657 <description>
12658 Thread catching the exception
12659 </description>
12660 </param>
12661 <param id="klass">
12662 <jclass method="method"/>
12663 <description>
12664 Class catching the exception
12665 </description>
12666 </param>
12667 <param id="method">
12668 <jmethodID class="klass"/>
12669 <description>
12670 Method catching the exception
12671 </description>
12672 </param>
12673 <param id="location">
12674 <jlocation/>
12675 <description>
12676 Location where exception is being caught
12677 </description>
12678 </param>
12679 <param id="exception">
12680 <jobject/>
12681 <description>
12682 Exception being caught
12683 </description>
12684 </param>
12685 </parameters>
12686 </event>
12687
12688 <event label="Thread Start"
12689 id="ThreadStart" const="JVMTI_EVENT_THREAD_START" num="52" phase="start">
12690 <description>
12691 Thread start events are generated by a new thread before its initial
12692 method executes.
12693 <p/>
12694 A thread may be listed in the array returned by
12695 <functionlink id="GetAllThreads"></functionlink>
12696 before its thread start event is generated.
12697 It is possible for other events to be generated
12698 on a thread before its thread start event.
12699 <p/>
12700 The event is sent on the newly started <paramlink id="thread"></paramlink>.
12701 </description>
12702 <origin>jvmdi</origin>
12703 <capabilities>
12704 </capabilities>
12705 <parameters>
12706 <param id="jni_env">
12707 <outptr>
12708 <struct>JNIEnv</struct>
12709 </outptr>
12710 <description>
12711 The JNI environment of the event (current) thread.
12712 </description>
12713 </param>
12714 <param id="thread">
12715 <jthread/>
12716 <description>
12717 Thread starting
12718 </description>
12719 </param>
12720 </parameters>
12721 </event>
12722
12723 <event label="Thread End"
12724 id="ThreadEnd" const="JVMTI_EVENT_THREAD_END" filtered="thread" num="53" phase="start">
12725 <description>
12726 Thread end events are generated by a terminating thread
12727 after its initial method has finished execution.
12728 <p/>
12729 A thread may be listed in the array returned by
12730 <functionlink id="GetAllThreads"></functionlink>
12731 after its thread end event is generated.
12732 No events are generated on a thread
12733 after its thread end event.
12734 <p/>
12735 The event is sent on the dying <paramlink id="thread"></paramlink>.
12736 </description>
12737 <origin>jvmdi</origin>
12738 <capabilities>
12739 </capabilities>
12740 <parameters>
12741 <param id="jni_env">
12742 <outptr>
12743 <struct>JNIEnv</struct>
12744 </outptr>
12745 <description>
12746 The JNI environment of the event (current) thread.
12747 </description>
12748 </param>
12749 <param id="thread">
12750 <jthread/>
12751 <description>
12752 Thread ending
12753 </description>
12754 </param>
12755 </parameters>
12756 </event>
12757
12758 <event label="Class Load"
12759 id="ClassLoad" const="JVMTI_EVENT_CLASS_LOAD" filtered="thread" phase="start" num="55">
12760 <description>
12761 A class load event is generated
12762 <functionlink id="GetLoadedClasses">when a class or interface is created.</functionlink>.
12763 <p/>
12764 Array class creation does not generate a class load event.
12765 The creation of a primitive class (for example, java.lang.Integer.TYPE)
12766 does not generate a class load event.
12767 <p/>
12768 The order of class load events generated by a particular thread is guaranteed
12769 to match the order of class loading within that thread.
12770 <p/>
12771 This event is sent at an early stage in loading the class. As
12772 a result the class should be used carefully. Note, for example,
12773 that methods and fields are not yet loaded, so queries for methods,
12774 fields, subclasses, and so on will not give correct results.
12775 See "Loading of Classes and Interfaces" in the <i>Java Language
12776 Specification</i>. For most
12777 purposes the <eventlink id="ClassPrepare"></eventlink> event will
12778 be more useful.
12779 </description>
12780 <origin>jvmdi</origin>
12781 <capabilities>
12782 </capabilities>
12783 <parameters>
12784 <param id="jni_env">
12785 <outptr>
12786 <struct>JNIEnv</struct>
12787 </outptr>
12788 <description>
12789 The JNI environment of the event (current) thread
12790 </description>
12791 </param>
12792 <param id="thread">
12793 <jthread/>
12794 <description>
12795 Thread loading the class
12796 </description>
12797 </param>
12798 <param id="klass">
12799 <jclass/>
12800 <description>
12801 Class being loaded
12802 </description>
12803 </param>
12804 </parameters>
12805 </event>
12806
12807 <elide>
12808 <event label="Class Unload"
12809 id="ClassUnload" const="JVMTI_EVENT_CLASS_UNLOAD" num="57">
12810 <description>
12811 A class unload event is generated when the class is about to be unloaded.
12812 Class unload events take place during garbage collection and must be
12813 handled extremely carefully. The garbage collector holds many locks
12814 and has suspended all other threads, so the event handler cannot depend
12815 on the ability to acquire any locks. The class unload event handler should
12816 do as little as possible, perhaps by queuing information to be processed
12817 later. In particular, the <code>jclass</code> should be used only in
12818 the JNI function <code>isSameObject</code> or in the following <jvmti/> functions:
12819 <ul>
12820 <li><functionlink id="GetClassSignature"></functionlink></li>
12821 <li><functionlink id="GetSourceFileName"></functionlink></li>
12822 <li><functionlink id="IsInterface"></functionlink></li>
12823 <li><functionlink id="IsArrayClass"></functionlink></li>
12824 </ul>
12825 </description>
12826 <origin>jvmdi</origin>
12827 <capabilities>
12828 </capabilities>
12829 <parameters>
12830 <param id="jni_env">
12831 <outptr>
12832 <struct>JNIEnv</struct>
12833 </outptr>
12834 <description>
12835 The JNI environment of the event (current) thread
12836 </description>
12837 </param>
12838 <param id="thread">
12839 <jthread/>
12840 <description>
12841 Thread generating the class unload
12842 </description>
12843 </param>
12844 <param id="klass">
12845 <jclass/>
12846 <description>
12847 Class being unloaded
12848 </description>
12849 </param>
12850 </parameters>
12851 </event>
12852 </elide>
12853
12854 <event label="Class Prepare"
12855 id="ClassPrepare" const="JVMTI_EVENT_CLASS_PREPARE" filtered="thread" phase="start" num="56">
12856 <description>
12857 A class prepare event is generated when class preparation is complete.
12858 At this point, class fields, methods, and implemented interfaces are
12859 available, and no code from the class has been executed. Since array
12860 classes never have fields or methods, class prepare events are not
12861 generated for them. Class prepare events are not generated for
12862 primitive classes (for example, <code>java.lang.Integer.TYPE</code>).
12863 </description>
12864 <origin>jvmdi</origin>
12865 <capabilities>
12866 </capabilities>
12867 <parameters>
12868 <param id="jni_env">
12869 <outptr>
12870 <struct>JNIEnv</struct>
12871 </outptr>
12872 <description>
12873 The JNI environment of the event (current) thread
12874 </description>
12875 </param>
12876 <param id="thread">
12877 <jthread/>
12878 <description>
12879 Thread generating the class prepare
12880 </description>
12881 </param>
12882 <param id="klass">
12883 <jclass/>
12884 <description>
12885 Class being prepared
12886 </description>
12887 </param>
12888 </parameters>
12889 </event>
12890
12891 <event label="Class File Load Hook" phase="any"
12892 id="ClassFileLoadHook" const="JVMTI_EVENT_CLASS_FILE_LOAD_HOOK" num="54">
12893 <description>
12894 This event is sent when the VM obtains class file data,
12895 but before it constructs
12896 the in-memory representation for that class.
12897 This event is also sent when the class is being modified by the
12898 <functionlink id="RetransformClasses"/> function or
12899 the <functionlink id="RedefineClasses"/> function,
12900 called in any <jvmti/> environment.
12901 The agent can instrument
12902 the existing class file data sent by the VM to include profiling/debugging hooks.
12903 See the description of
12904 <internallink id="bci">bytecode instrumentation</internallink>
12905 for usage information.
12906 <p/>
12907 When the capabilities
12908 <internallink id="jvmtiCapabilities.can_generate_early_class_hook_events">
12909 <code>can_generate_early_class_hook_events</code></internallink> and
12910 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events">
12911 <code>can_generate_all_class_hook_events</code></internallink>
12912 are enabled then this event may be sent in the primordial phase.
12913 Otherwise, this event may be sent before the VM is initialized (the start
12914 <functionlink id="GetPhase">phase</functionlink>).
12915 Some classes might not be compatible
12916 with the function (eg. ROMized classes or implementation defined classes) and this event will
12917 not be generated for these classes.
12918 <p/>
12919 The agent must allocate the space for the modified
12920 class file data buffer
12921 using the memory allocation function
12922 <functionlink id="Allocate"></functionlink> because the
12923 VM is responsible for freeing the new class file data buffer
12924 using <functionlink id="Deallocate"></functionlink>.
12925 <p/>
12926 If the agent wishes to modify the class file, it must set
12927 <code>new_class_data</code> to point
12928 to the newly instrumented class file data buffer and set
12929 <code>new_class_data_len</code> to the length of that
12930 buffer before returning
12931 from this call. If no modification is desired, the agent simply
12932 does not set <code>new_class_data</code>. If multiple agents
12933 have enabled this event the results are chained. That is, if
12934 <code>new_class_data</code> has been set, it becomes the
12935 <code>class_data</code> for the next agent.
12936 <p/>
12937 When handling a class load in the live phase, then the
12938 <functionlink id="GetNamedModule"></functionlink>
12939 function can be used to map class loader and a package name to a module.
12940 When a class is being redefined or retransformed then
12941 <code>class_being_redefined</code> is non <code>NULL</code> and so
12942 the JNI <code>GetModule</code> function can also be used
12943 to obtain the Module.
12944 <p/>
12945 The order that this event is sent to each environment differs
12946 from other events.
12947 This event is sent to environments in the following order:
12948 <ul>
12949 <li><fieldlink id="can_retransform_classes"
12950 struct="jvmtiCapabilities">retransformation
12951 incapable</fieldlink>
12952 environments, in the
12953 order in which they were created
12954 </li>
12955 <li><fieldlink id="can_retransform_classes"
12956 struct="jvmtiCapabilities">retransformation
12957 capable</fieldlink>
12958 environments, in the
12959 order in which they were created
12960 </li>
12961 </ul>
12962 When triggered by <functionlink id="RetransformClasses"/>,
12963 this event is sent only to <fieldlink id="can_retransform_classes"
12964 struct="jvmtiCapabilities">retransformation
12965 capable</fieldlink>
12966 environments.
12967 </description>
12968 <origin>jvmpi</origin>
12969 <capabilities>
12970 <capability id="can_generate_all_class_hook_events"></capability>
12971 <capability id="can_generate_early_class_hook_events"></capability>
12972 </capabilities>
12973 <parameters>
12974 <param id="jni_env">
12975 <outptr>
12976 <struct>JNIEnv</struct>
12977 </outptr>
12978 <description>
12979 The JNI environment of the event (current) thread.
12980 </description>
12981 </param>
12982 <param id="class_being_redefined">
12983 <jclass/>
12984 <description>
12985 The class being
12986 <functionlink id="RedefineClasses">redefined</functionlink> or
12987 <functionlink id="RetransformClasses">retransformed</functionlink>.
12988 <code>NULL</code> if sent by class load.
12989 </description>
12990 </param>
12991 <param id="loader">
12992 <jobject/>
12993 <description>
12994 The class loader loading the class.
12995 <code>NULL</code> if the bootstrap class loader.
12996 </description>
12997 </param>
12998 <param id="name">
12999 <vmbuf><char/></vmbuf>
13000 <description>
13001 Name of class being loaded as a VM internal qualified name
13002 (for example, "java/util/List"), encoded as a
13003 <internallink id="mUTF">modified UTF-8</internallink> string.
13004 Note: if the class is defined with a <code>NULL</code> name or
13005 without a name specified, <code>name</code> will be <code>NULL</code>.
13006 </description>
13007 </param>
13008 <param id="protection_domain">
13009 <jobject/>
13010 <description>
13011 The <code>ProtectionDomain</code> of the class.
13012 </description>
13013 </param>
13014 <param id="class_data_len">
13015 <jint/>
13016 <description>
13017 Length of current class file data buffer.
13018 </description>
13019 </param>
13020 <param id="class_data">
13021 <vmbuf><uchar/></vmbuf>
13022 <description>
13023 Pointer to the current class file data buffer.
13024 </description>
13025 </param>
13026 <param id="new_class_data_len">
13027 <outptr><jint/></outptr>
13028 <description>
13029 Pointer to the length of the new class file data buffer.
13030 </description>
13031 </param>
13032 <param id="new_class_data">
13033 <agentbuf incount="new_class_data_len"><uchar/></agentbuf>
13034 <description>
13035 Pointer to the pointer to the instrumented class file data buffer.
13036 </description>
13037 </param>
13038 </parameters>
13039 </event>
13040
13041 <event label="VM Start Event"
13042 id="VMStart" const="JVMTI_EVENT_VM_START" num="57" phase="start">
13043 <description>
13044 The VM start event signals the start of the VM.
13045 At this time JNI is live but the VM is not yet fully initialized.
13046 Once this event is generated, the agent is free to call any JNI function.
13047 This event signals the beginning of the start phase,
13048 <jvmti/> functions permitted in the start phase may be called.
13049 <p/>
13050 The timing of this event may depend on whether the agent has added the
13051 <internallink id="jvmtiCapabilities.can_generate_early_vmstart">
13052 <code>can_generate_early_vmstart</code></internallink> capability or not.
13053 If the capability has been added then the VM posts the event as early
13054 as possible. The VM is capable of executing bytecode but it may not have
13055 initialized to the point where it can load classes in modules other than
13056 <code>java.base</code>, or even arbitrary classes in <code>java.base</code>.
13057 Agents that do load-time instrumentation in this
13058 phase must take great care when instrumenting code that potentially
13059 executes in this phase. Extreme care should also be taken with JNI
13060 <code>FindClass</code> as it may not be possible to load classes and attempts
13061 to do so may result in unpredictable behavior, maybe even stability issues
13062 on some VM implementations.
13063 If the capability has not been added then the VM delays posting this
13064 event until it is capable of loading classes in modules other than
13065 <code>java.base</code> or the VM has completed its initialization.
13066 Agents that create more than one JVM TI environment, where the
13067 capability is added to some but not all environments, may observe the
13068 start phase beginning earlier in the JVM TI environments that possess
13069 the capability.
13070 <p/>
13071 In the case of VM start-up failure, this event will not be sent.
13072 </description>
13073 <origin>jvmdi</origin>
13074 <capabilities>
13075 </capabilities>
13076 <parameters>
13077 <param id="jni_env">
13078 <outptr>
13079 <struct>JNIEnv</struct>
13080 </outptr>
13081 <description>
13082 The JNI environment of the event (current) thread.
13083 </description>
13084 </param>
13085 </parameters>
13086 </event>
13087
13088 <event label="VM Initialization Event"
13089 id="VMInit" const="JVMTI_EVENT_VM_INIT" num="50">
13090 <description>
13091 The VM initialization event signals the completion of VM initialization. Once
13092 this event is generated, the agent is free to call any JNI or <jvmti/>
13093 function. The VM initialization event can be preceded by or can be concurrent
13094 with other events, but
13095 the preceding events should be handled carefully, if at all, because the
13096 VM has not completed its initialization. The thread start event for the
13097 main application thread is guaranteed not to occur until after the
13098 handler for the VM initialization event returns.
13099 <p/>
13100 In the case of VM start-up failure, this event will not be sent.
13101 </description>
13102 <origin>jvmdi</origin>
13103 <capabilities>
13104 </capabilities>
13105 <parameters>
13106 <param id="jni_env">
13107 <outptr>
13108 <struct>JNIEnv</struct>
13109 </outptr>
13110 <description>
13111 The JNI environment of the event (current) thread.
13112 </description>
13113 </param>
13114 <param id="thread">
13115 <jthread/>
13116 <description>
13117 The initial thread
13118 </description>
13119 </param>
13120 </parameters>
13121 </event>
13122
13123 <event label="VM Death Event"
13124 id="VMDeath" const="JVMTI_EVENT_VM_DEATH" num="51">
13125 <description>
13126 The VM death event notifies the agent of the termination of the VM.
13127 No events will occur after the VMDeath event.
13128 <p/>
13129 In the case of VM start-up failure, this event will not be sent.
13130 Note that <internallink id="onunload">Agent_OnUnload</internallink>
13131 will still be called in these cases.
13132 </description>
13133 <origin>jvmdi</origin>
13134 <capabilities>
13135 </capabilities>
13136 <parameters>
13137 <param id="jni_env">
13138 <outptr>
13139 <struct>JNIEnv</struct>
13140 </outptr>
13141 <description>
13142 The JNI environment of the event (current) thread
13143 </description>
13144 </param>
13145 </parameters>
13146 </event>
13147
13148 <event label="Compiled Method Load" phase="start"
13149 id="CompiledMethodLoad" const="JVMTI_EVENT_COMPILED_METHOD_LOAD" num="68">
13150 <description>
13151 Sent when a method is compiled and loaded into memory by the VM.
13152 If it is unloaded, the <eventlink id="CompiledMethodUnload"/> event is sent.
13153 If it is moved, the <eventlink id="CompiledMethodUnload"/> event is sent,
13154 followed by a new <code>CompiledMethodLoad</code> event.
13155 Note that a single method may have multiple compiled forms, and that
13156 this event will be sent for each form.
13157 Note also that several methods may be inlined into a single
13158 address range, and that this event will be sent for each method.
13159 <p/>
13160 These events can be sent after their initial occurrence with
13161 <functionlink id="GenerateEvents"></functionlink>.
13162 </description>
13163 <origin>jvmpi</origin>
13164 <typedef id="jvmtiAddrLocationMap" label="Native address to location entry">
13165 <field id="start_address">
13166 <vmbuf><void/></vmbuf>
13167 <description>
13168 Starting native address of code corresponding to a location
13169 </description>
13170 </field>
13171 <field id="location">
13172 <jlocation/>
13173 <description>
13174 Corresponding location. See
13175 <functionlink id="GetJLocationFormat"></functionlink>
13176 for the meaning of location.
13177 </description>
13178 </field>
13179 </typedef>
13180 <capabilities>
13181 <required id="can_generate_compiled_method_load_events"></required>
13182 </capabilities>
13183 <parameters>
13184 <param id="klass">
13185 <jclass method="method"/>
13186 <description>
13187 Class of the method being compiled and loaded
13188 </description>
13189 </param>
13190 <param id="method">
13191 <jmethodID class="klass"/>
13192 <description>
13193 Method being compiled and loaded
13194 </description>
13195 </param>
13196 <param id="code_size">
13197 <jint/>
13198 <description>
13199 Size of compiled code
13200 </description>
13201 </param>
13202 <param id="code_addr">
13203 <vmbuf><void/></vmbuf>
13204 <description>
13205 Address where compiled method code is loaded
13206 </description>
13207 </param>
13208 <param id="map_length">
13209 <jint/>
13210 <description>
13211 Number of <typelink id="jvmtiAddrLocationMap"></typelink>
13212 entries in the address map.
13213 Zero if mapping information cannot be supplied.
13214 </description>
13215 </param>
13216 <param id="map">
13217 <vmbuf><struct>jvmtiAddrLocationMap</struct></vmbuf>
13218 <description>
13219 Map from native addresses to location.
13220 The native address range of each entry is from
13221 <fieldlink id="start_address" struct="jvmtiAddrLocationMap"></fieldlink>
13222 to <code>start_address-1</code> of the next entry.
13223 <code>NULL</code> if mapping information cannot be supplied.
13224 </description>
13225 </param>
13226 <param id="compile_info">
13227 <vmbuf><void/></vmbuf>
13228 <description>
13229 VM-specific compilation information.
13230 The referenced compile information is managed by the VM
13231 and must not depend on the agent for collection.
13232 A VM implementation defines the content and lifetime
13233 of the information.
13234 </description>
13235 </param>
13236 </parameters>
13237 </event>
13238
13239 <event label="Compiled Method Unload" phase="start"
13240 id="CompiledMethodUnload" const="JVMTI_EVENT_COMPILED_METHOD_UNLOAD" num="69">
13241 <description>
13242 Sent when a compiled method is unloaded from memory.
13243 This event might not be sent on the thread which performed the unload.
13244 This event may be sent sometime after the unload occurs, but
13245 will be sent before the memory is reused
13246 by a newly generated compiled method. This event may be sent after
13247 the class is unloaded.
13248 </description>
13249 <origin>jvmpi</origin>
13250 <capabilities>
13251 <required id="can_generate_compiled_method_load_events"></required>
13252 </capabilities>
13253 <parameters>
13254 <param id="klass">
13255 <jclass method="method"/>
13256 <description>
13257 Class of the compiled method being unloaded.
13258 </description>
13259 </param>
13260 <param id="method">
13261 <jmethodID class="klass"/>
13262 <description>
13263 Compiled method being unloaded.
13264 For identification of the compiled method only -- the class
13265 may be unloaded and therefore the method should not be used
13266 as an argument to further JNI or <jvmti/> functions.
13267 </description>
13268 </param>
13269 <param id="code_addr">
13270 <vmbuf><void/></vmbuf>
13271 <description>
13272 Address where compiled method code was loaded.
13273 For identification of the compiled method only --
13274 the space may have been reclaimed.
13275 </description>
13276 </param>
13277 </parameters>
13278 </event>
13279
13280 <event label="Dynamic Code Generated" phase="any"
13281 id="DynamicCodeGenerated" const="JVMTI_EVENT_DYNAMIC_CODE_GENERATED" num="70">
13282 <description>
13283 Sent when a component of the virtual machine is generated dynamically.
13284 This does not correspond to Java programming language code that is
13285 compiled--see <eventlink id="CompiledMethodLoad"></eventlink>.
13286 This is for native code--for example, an interpreter that is generated
13287 differently depending on command-line options.
13288 <p/>
13289 Note that this event has no controlling capability.
13290 If a VM cannot generate these events, it simply does not send any.
13291 <p/>
13292 These events can be sent after their initial occurrence with
13293 <functionlink id="GenerateEvents"></functionlink>.
13294 </description>
13295 <origin>jvmpi</origin>
13296 <capabilities>
13297 </capabilities>
13298 <parameters>
13299 <param id="name">
13300 <vmbuf><char/></vmbuf>
13301 <description>
13302 Name of the code, encoded as a
13303 <internallink id="mUTF">modified UTF-8</internallink> string.
13304 Intended for display to an end-user.
13305 The name might not be unique.
13306 </description>
13307 </param>
13308 <param id="address">
13309 <vmbuf><void/></vmbuf>
13310 <description>
13311 Native address of the code
13312 </description>
13313 </param>
13314 <param id="length">
13315 <jint/>
13316 <description>
13317 Length in bytes of the code
13318 </description>
13319 </param>
13320 </parameters>
13321 </event>
13322
13323 <event label="Data Dump Request"
13324 id="DataDumpRequest" const="JVMTI_EVENT_DATA_DUMP_REQUEST" num="71">
13325 <description>
13326 Sent by the VM to request the agent to dump its data. This
13327 is just a hint and the agent need not react to this event.
13328 This is useful for processing command-line signals from users. For
13329 example, in the Java 2 SDK a CTRL-Break on Win32 and a CTRL-\ on Linux
13330 causes the VM to send this event to the agent.
13331 </description>
13332 <origin>jvmpi</origin>
13333 <capabilities>
13334 </capabilities>
13335 <parameters>
13336 </parameters>
13337 </event>
13338
13339 <event label="Monitor Contended Enter"
13340 id="MonitorContendedEnter" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTER" filtered="thread" num="75">
13341 <description>
13342 Sent when a thread is attempting to enter a Java programming language
13343 monitor already acquired by another thread.
13344 </description>
13345 <origin>jvmpi</origin>
13346 <capabilities>
13347 <required id="can_generate_monitor_events"></required>
13348 </capabilities>
13349 <parameters>
13350 <param id="jni_env">
13351 <outptr>
13352 <struct>JNIEnv</struct>
13353 </outptr>
13354 <description>
13355 The JNI environment of the event (current) thread
13356 </description>
13357 </param>
13358 <param id="thread">
13359 <jthread/>
13360 <description>
13361 JNI local reference to the thread
13362 attempting to enter the monitor
13363 </description>
13364 </param>
13365 <param id="object">
13366 <jobject/>
13367 <description>
13368 JNI local reference to the monitor
13369 </description>
13370 </param>
13371 </parameters>
13372 </event>
13373
13374 <event label="Monitor Contended Entered"
13375 id="MonitorContendedEntered" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTERED" filtered="thread" num="76">
13376 <description>
13377 Sent when a thread enters a Java programming language
13378 monitor after waiting for it to be released by another thread.
13379 </description>
13380 <origin>jvmpi</origin>
13381 <capabilities>
13382 <required id="can_generate_monitor_events"></required>
13383 </capabilities>
13384 <parameters>
13385 <param id="jni_env">
13386 <outptr>
13387 <struct>JNIEnv</struct>
13388 </outptr>
13389 <description>
13390 The JNI environment of the event (current) thread
13391 </description>
13392 </param>
13393 <param id="thread">
13394 <jthread/>
13395 <description>
13396 JNI local reference to the thread entering
13397 the monitor
13398 </description>
13399 </param>
13400 <param id="object">
13401 <jobject/>
13402 <description>
13403 JNI local reference to the monitor
13404 </description>
13405 </param>
13406 </parameters>
13407 </event>
13408
13409 <event label="Monitor Wait"
13410 id="MonitorWait" const="JVMTI_EVENT_MONITOR_WAIT" filtered="thread" num="73">
13411 <description>
13412 Sent when a thread is about to wait on an object.
13413 </description>
13414 <origin>jvmpi</origin>
13415 <capabilities>
13416 <required id="can_generate_monitor_events"></required>
13417 </capabilities>
13418 <parameters>
13419 <param id="jni_env">
13420 <outptr>
13421 <struct>JNIEnv</struct>
13422 </outptr>
13423 <description>
13424 The JNI environment of the event (current) thread
13425 </description>
13426 </param>
13427 <param id="thread">
13428 <jthread/>
13429 <description>
13430 JNI local reference to the thread about to wait
13431 </description>
13432 </param>
13433 <param id="object">
13434 <jobject/>
13435 <description>
13436 JNI local reference to the monitor
13437 </description>
13438 </param>
13439 <param id="timeout">
13440 <jlong/>
13441 <description>
13442 The number of milliseconds the thread will wait
13443 </description>
13444 </param>
13445 </parameters>
13446 </event>
13447
13448 <event label="Monitor Waited"
13449 id="MonitorWaited" const="JVMTI_EVENT_MONITOR_WAITED" filtered="thread" num="74">
13450 <description>
13451 Sent when a thread finishes waiting on an object.
13452 </description>
13453 <origin>jvmpi</origin>
13454 <capabilities>
13455 <required id="can_generate_monitor_events"></required>
13456 </capabilities>
13457 <parameters>
13458 <param id="jni_env">
13459 <outptr>
13460 <struct>JNIEnv</struct>
13461 </outptr>
13462 <description>
13463 The JNI environment of the event (current) thread
13464 </description>
13465 </param>
13466 <param id="thread">
13467 <jthread/>
13468 <description>
13469 JNI local reference to the thread that was finished waiting
13470 </description>
13471 </param>
13472 <param id="object">
13473 <jobject/>
13474 <description>
13475 JNI local reference to the monitor.
13476 </description>
13477 </param>
13478 <param id="timed_out">
13479 <jboolean/>
13480 <description>
13481 True if the monitor timed out
13482 </description>
13483 </param>
13484 </parameters>
13485 </event>
13486
13487 <event label="Resource Exhausted"
13488 id="ResourceExhausted" const="JVMTI_EVENT_RESOURCE_EXHAUSTED" num="80"
13489 since="1.1">
13490 <description>
13491 Sent when a VM resource needed by a running application has been exhausted.
13492 Except as required by the optional capabilities, the set of resources
13493 which report exhaustion is implementation dependent.
13494 <p/>
13495 The following bit flags define the properties of the resource exhaustion:
13496 <constants id="jvmtiResourceExhaustionFlags"
13497 label="Resource Exhaustion Flags"
13498 kind="bits"
13499 since="1.1">
13500 <constant id="JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR" num="0x0001">
13501 After this event returns, the VM will throw a
13502 <code>java.lang.OutOfMemoryError</code>.
13503 </constant>
13504 <constant id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP" num="0x0002">
13505 The VM was unable to allocate memory from the <tm>Java</tm>
13506 platform <i>heap</i>.
13507 The <i>heap</i> is the runtime
13508 data area from which memory for all class instances and
13509 arrays are allocated.
13510 </constant>
13511 <constant id="JVMTI_RESOURCE_EXHAUSTED_THREADS" num="0x0004">
13512 The VM was unable to create a thread.
13513 </constant>
13514 </constants>
13515 </description>
13516 <origin>new</origin>
13517 <capabilities>
13518 <capability id="can_generate_resource_exhaustion_heap_events">
13519 Can generate events when the VM is unable to allocate memory from the
13520 <internallink id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP">heap</internallink>.
13521 </capability>
13522 <capability id="can_generate_resource_exhaustion_threads_events">
13523 Can generate events when the VM is unable to
13524 <internallink id="JVMTI_RESOURCE_EXHAUSTED_THREADS">create
13525 a thread</internallink>.
13526 </capability>
13527 </capabilities>
13528 <parameters>
13529 <param id="jni_env">
13530 <outptr>
13531 <struct>JNIEnv</struct>
13532 </outptr>
13533 <description>
13534 The JNI environment of the event (current) thread
13535 </description>
13536 </param>
13537 <param id="flags">
13538 <jint/>
13539 <description>
13540 Flags defining the properties of the of resource exhaustion
13541 as specified by the
13542 <internallink id="jvmtiResourceExhaustionFlags">Resource
13543 Exhaustion Flags</internallink>.
13544 </description>
13545 </param>
13546 <param id="reserved">
13547 <vmbuf><void/></vmbuf>
13548 <description>
13549 Reserved.
13550 </description>
13551 </param>
13552 <param id="description">
13553 <vmbuf><char/></vmbuf>
13554 <description>
13555 Description of the resource exhaustion, encoded as a
13556 <internallink id="mUTF">modified UTF-8</internallink> string.
13557 </description>
13558 </param>
13559 </parameters>
13560 </event>
13561
13562 <event label="VM Object Allocation"
13563 id="VMObjectAlloc" const="JVMTI_EVENT_VM_OBJECT_ALLOC" num="84">
13564 <description>
13565 Sent when a method causes the virtual machine to directly allocate an
13566 Object visible to Java programming language code.
13567 Generally object allocation should be detected by instrumenting
13568 the bytecodes of allocating methods.
13569 Object allocation generated in native code by JNI function
13570 calls should be detected using
13571 <internallink id="jniIntercept">JNI function interception</internallink>.
13572 Some methods might not have associated bytecodes and are not
13573 native methods, they instead are executed directly by the
13574 VM. These methods should send this event.
13575 Virtual machines which are incapable of bytecode instrumentation
13576 for some or all of their methods can send this event.
13577
13578 Note that the <internallink
13579 id="SampledObjectAlloc">SampledObjectAlloc</internallink>
13580 event is triggered on all Java object allocations, including those
13581 caused by bytecode method execution, JNI method execution, and
13582 directly by VM methods.
13583 <p/>
13584 Typical examples where this event might be sent:
13585 <ul>
13586 <li>Reflection -- for example, <code>java.lang.Class.newInstance()</code></li>
13587 <li>Methods not represented by bytecodes -- for example, VM intrinsics and
13588 J2ME preloaded classes</li>
13589 </ul>
13590 Cases where this event would not be generated:
13591 <ul>
13592 <li>Allocation due to bytecodes -- for example, the <code>new</code>
13593 and <code>newarray</code> VM instructions</li>
13594 <li>Allocation due to JNI function calls -- for example,
13595 <code>AllocObject</code></li>
13596 <li>Allocations during VM initialization</li>
13597 <li>VM internal objects</li>
13598 </ul>
13599 </description>
13600 <origin>new</origin>
13601 <capabilities>
13602 <required id="can_generate_vm_object_alloc_events"></required>
13603 </capabilities>
13604 <parameters>
13605 <param id="jni_env">
13606 <outptr>
13607 <struct>JNIEnv</struct>
13608 </outptr>
13609 <description>
13610 The JNI environment of the event (current) thread
13611 </description>
13612 </param>
13613 <param id="thread">
13614 <jthread/>
13615 <description>
13616 Thread allocating the object.
13617 </description>
13618 </param>
13619 <param id="object">
13620 <jobject/>
13621 <description>
13622 JNI local reference to the object that was allocated.
13623 </description>
13624 </param>
13625 <param id="object_klass">
13626 <jclass/>
13627 <description>
13628 JNI local reference to the class of the object.
13629 </description>
13630 </param>
13631 <param id="size">
13632 <jlong/>
13633 <description>
13634 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
13635 </description>
13636 </param>
13637 </parameters>
13638 </event>
13639
13640 <event label="Sampled Object Allocation"
13641 id="SampledObjectAlloc" const="JVMTI_EVENT_SAMPLED_OBJECT_ALLOC" filtered="thread" num="86" since="11">
13642 <description>
13643 Sent when an allocated object is sampled.
13644 By default, the sampling interval is set to 512KB. The sampling is semi-random to avoid
13645 pattern-based bias and provides an approximate overall average interval over long periods of
13646 sampling.
13647 <p/>
13648 Each thread tracks how many bytes it has allocated since it sent the last event.
13649 When the number of bytes exceeds the sampling interval, it will send another event.
13650 This implies that, on average, one object will be sampled every time a thread has
13651 allocated 512KB bytes since the last sample.
13652 <p/>
13653 Note that the sampler is pseudo-random: it will not sample every 512KB precisely.
13654 The goal of this is to ensure high quality sampling even if allocation is
13655 happening in a fixed pattern (i.e., the same set of objects are being allocated
13656 every 512KB).
13657 <p/>
13658 If another sampling interval is required, the user can call
13659 <functionlink id="SetHeapSamplingInterval"></functionlink> with a strictly positive integer value,
13660 representing the new sampling interval.
13661 <p/>
13662 This event is sent once the sampled allocation has been performed. It provides the object, stack trace
13663 of the allocation, the thread allocating, the size of allocation, and the object's class.
13664 <p/>
13665 A typical use case of this system is to determine where heap allocations originate.
13666 In conjunction with weak references and the function
13667 <functionlink id="GetStackTrace"></functionlink>, a user can track which objects were allocated from which
13668 stack trace, and which are still live during the execution of the program.
13669 </description>
13670 <origin>new</origin>
13671 <capabilities>
13672 <required id="can_generate_sampled_object_alloc_events"></required>
13673 </capabilities>
13674 <parameters>
13675 <param id="jni_env">
13676 <outptr>
13677 <struct>JNIEnv</struct>
13678 </outptr>
13679 <description>
13680 The JNI environment of the event (current) thread.
13681 </description>
13682 </param>
13683 <param id="thread">
13684 <jthread/>
13685 <description>
13686 Thread allocating the object.
13687 </description>
13688 </param>
13689 <param id="object">
13690 <jobject/>
13691 <description>
13692 JNI local reference to the object that was allocated.
13693 </description>
13694 </param>
13695 <param id="object_klass">
13696 <jclass/>
13697 <description>
13698 JNI local reference to the class of the object
13699 </description>
13700 </param>
13701 <param id="size">
13702 <jlong/>
13703 <description>
13704 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
13705 </description>
13706 </param>
13707 </parameters>
13708 </event>
13709
13710 <event label="Object Free"
13711 id="ObjectFree" const="JVMTI_EVENT_OBJECT_FREE" num="83">
13712 <description>
13713 An Object Free event is sent when the garbage collector frees an object.
13714 Events are only sent for tagged objects--see
13715 <internallink id="Heap">heap functions</internallink>.
13716 <p/>
13717 The event handler must not use JNI functions and
13718 must not use <jvmti/> functions except those which
13719 specifically allow such use (see the raw monitor, memory management,
13720 and environment local storage functions).
13721 </description>
13722 <origin>new</origin>
13723 <capabilities>
13724 <required id="can_generate_object_free_events"></required>
13725 </capabilities>
13726 <parameters>
13727 <param id="tag">
13728 <jlong/>
13729 <description>
13730 The freed object's tag
13731 </description>
13732 </param>
13733 </parameters>
13734 </event>
13735
13736 <event label="Garbage Collection Start"
13737 id="GarbageCollectionStart" const="JVMTI_EVENT_GARBAGE_COLLECTION_START" num="81">
13738 <description>
13739 A Garbage Collection Start event is sent when a
13740 garbage collection pause begins.
13741 Only stop-the-world collections are reported--that is, collections during
13742 which all threads cease to modify the state of the Java virtual machine.
13743 This means that some collectors will never generate these events.
13744 This event is sent while the VM is still stopped, thus
13745 the event handler must not use JNI functions and
13746 must not use <jvmti/> functions except those which
13747 specifically allow such use (see the raw monitor, memory management,
13748 and environment local storage functions).
13749 <p/>
13750 This event is always sent as a matched pair with
13751 <eventlink id="GarbageCollectionFinish"/>
13752 (assuming both events are enabled) and no garbage collection
13753 events will occur between them.
13754 </description>
13755 <origin>new</origin>
13756 <capabilities>
13757 <required id="can_generate_garbage_collection_events"></required>
13758 </capabilities>
13759 <parameters>
13760 </parameters>
13761 </event>
13762
13763 <event label="Garbage Collection Finish"
13764 id="GarbageCollectionFinish" const="JVMTI_EVENT_GARBAGE_COLLECTION_FINISH" num="82">
13765 <description>
13766 A Garbage Collection Finish event is sent when a
13767 garbage collection pause ends.
13768 This event is sent while the VM is still stopped, thus
13769 the event handler must not use JNI functions and
13770 must not use <jvmti/> functions except those which
13771 specifically allow such use (see the raw monitor, memory management,
13772 and environment local storage functions).
13773 <p/>
13774 Some agents may need to do post garbage collection operations that
13775 require the use of the disallowed <jvmti/> or JNI functions. For these
13776 cases an agent thread can be created which waits on a raw monitor,
13777 and the handler for the Garbage Collection Finish event simply
13778 notifies the raw monitor
13779 <p/>
13780 This event is always sent as a matched pair with
13781 <eventlink id="GarbageCollectionStart"/> (assuming both events are enabled).
13782 <issue>
13783 The most important use of this event is to provide timing information,
13784 and thus additional information is not required. However,
13785 information about the collection which is "free" should be included -
13786 what that information is needs to be determined.
13787 </issue>
13788 </description>
13789 <origin>new</origin>
13790 <capabilities>
13791 <required id="can_generate_garbage_collection_events"></required>
13792 </capabilities>
13793 <parameters>
13794 </parameters>
13795 </event>
13796
13797 <elide>
13798 <event label="Verbose Output" phase="any"
13799 id="VerboseOutput" const="JVMTI_EVENT_VERBOSE_OUTPUT" num="85">
13800 <description>
13801 Send verbose messages as strings.
13802 <issue>
13803 This format is extremely fragile, as it can change with each
13804 platform, collector and version. Alternatives include:
13805 <ul>
13806 <li>building off Java programming language M and M APIs</li>
13807 <li>XML</li>
13808 <li>key/value pairs</li>
13809 <li>removing it</li>
13810 </ul>
13811 </issue>
13812 <issue>
13813 Though this seemed trivial to implement.
13814 In the RI it appears this will be quite complex.
13815 </issue>
13816 </description>
13817 <origin>new</origin>
13818 <capabilities>
13819 </capabilities>
13820 <parameters>
13821 <param id="flag">
13822 <enum>jvmtiVerboseFlag</enum>
13823 <description>
13824 Which verbose output is being sent.
13825 </description>
13826 </param>
13827 <param id="message">
13828 <vmbuf><char/></vmbuf>
13829 <description>
13830 Message text, encoded as a
13831 <internallink id="mUTF">modified UTF-8</internallink> string.
13832 </description>
13833 </param>
13834 </parameters>
13835 </event>
13836 </elide>
13837
13838 </eventsection>
13839
13840 <datasection>
13841 <intro>
13842 <jvmti/> extends the data types defined by JNI.
13843 </intro>
13844 <basetypes id="jniTypes" label="JNI Types Used in the JVM Tool Interface">
13845 <basetype id="jboolean">
13846 <description>
13847 Holds a Java programming language <code>boolean</code>.
13848 Unsigned 8 bits.
13849 </description>
13850 </basetype>
13851 <basetype id="jchar">
13852 <description>
13853 Holds a Java programming language <code>char</code>.
13854 Unsigned 16 bits.
13855 </description>
13856 </basetype>
13857 <basetype id="jint">
13858 <description>
13859 Holds a Java programming language <code>int</code>.
13860 Signed 32 bits.
13861 </description>
13862 </basetype>
13863 <basetype id="jlong">
13864 <description>
13865 Holds a Java programming language <code>long</code>.
13866 Signed 64 bits.
13867 </description>
13868 </basetype>
13869 <basetype id="jfloat">
13870 <description>
13871 Holds a Java programming language <code>float</code>.
13872 32 bits.
13873 </description>
13874 </basetype>
13875 <basetype id="jdouble">
13876 <description>
13877 Holds a Java programming language <code>double</code>.
13878 64 bits.
13879 </description>
13880 </basetype>
13881 <basetype id="jobject">
13882 <description>
13883 Holds a Java programming language object.
13884 </description>
13885 </basetype>
13886 <basetype id="jclass">
13887 <description>
13888 Holds a Java programming language class.
13889 </description>
13890 </basetype>
13891 <basetype id="jvalue">
13892 <description>
13893 Is a union of all primitive types and <code>jobject</code>. Thus, holds any Java
13894 programming language value.
13895 </description>
13896 </basetype>
13897 <basetype id="jfieldID">
13898 <description>
13899 Identifies a Java programming language field.
13900 <code>jfieldID</code>s returned by <jvmti/> functions and events may be
13901 safely stored.
13902 </description>
13903 </basetype>
13904 <basetype id="jmethodID">
13905 <description>
13906 Identifies a Java programming language method, initializer, or constructor.
13907 <code>jmethodID</code>s returned by <jvmti/> functions and events may be
13908 safely stored. However, if the class is unloaded, they become invalid
13909 and must not be used.
13910 </description>
13911 </basetype>
13912 <basetype id="JNIEnv">
13913 <description>
13914 Pointer to the JNI function table. Pointer to this (<code>JNIEnv *</code>)
13915 is a JNI environment.
13916 </description>
13917 </basetype>
13918 </basetypes>
13919
13920 <basetypes id="jvmtiTypes" label="JVM Tool Interface Base Types">
13921 <basetype id="jvmtiEnv">
13922 <description>
13923 The <jvmti/> <internallink id="environments">environment</internallink> pointer.
13924 See the <internallink id="FunctionSection">Function Section</internallink>.
13925 <code>jvmtiEnv</code> points to the
13926 <internallink id="FunctionTable">function table</internallink> pointer.
13927 </description>
13928 </basetype>
13929 <basetype id="jthread">
13930 <definition>typedef jobject jthread;</definition>
13931 <description>
13932 Subtype of <datalink id="jobject"></datalink> that holds a thread.
13933 </description>
13934 </basetype>
13935 <basetype id="jthreadGroup">
13936 <definition>typedef jobject jthreadGroup;</definition>
13937 <description>
13938 Subtype of <datalink id="jobject"></datalink> that holds a thread group.
13939 </description>
13940 </basetype>
13941 <basetype id="jlocation">
13942 <definition>typedef jlong jlocation;</definition>
13943 <description>
13944 A 64 bit value, representing a monotonically increasing
13945 executable position within a method.
13946 <code>-1</code> indicates a native method.
13947 See <functionlink id="GetJLocationFormat"></functionlink> for the format on a
13948 given VM.
13949 </description>
13950 </basetype>
13951 <basetype id="jrawMonitorID">
13952 <definition>struct _jrawMonitorID;
13953 typedef struct _jrawMonitorID *jrawMonitorID;</definition>
13954 <description>
13955 A raw monitor.
13956 </description>
13957 </basetype>
13958 <basetype id="jvmtiError">
13959 <description>
13960 Holds an error return code.
13961 See the <internallink id="ErrorSection">Error section</internallink> for possible values.
13962 <example>
13963 typedef enum {
13964 JVMTI_ERROR_NONE = 0,
13965 JVMTI_ERROR_INVALID_THREAD = 10,
13966 ...
13967 } jvmtiError;
13968 </example>
13969 </description>
13970 </basetype>
13971 <basetype id="jvmtiEvent">
13972 <description>
13973 An identifier for an event type.
13974 See the <internallink id="EventSection">Event section</internallink> for possible values.
13975 It is guaranteed that future versions of this specification will
13976 never assign zero as an event type identifier.
13977 <example>
13978 typedef enum {
13979 JVMTI_EVENT_SINGLE_STEP = 1,
13980 JVMTI_EVENT_BREAKPOINT = 2,
13981 ...
13982 } jvmtiEvent;
13983 </example>
13984 </description>
13985 </basetype>
13986 <basetype id="jvmtiEventCallbacks" name="eventCallbacks">
13987 <description>
13988 The callbacks used for events.
13989 <example>
13990 typedef struct {
13991 jvmtiEventVMInit VMInit;
13992 jvmtiEventVMDeath VMDeath;
13993 ...
13994 } jvmtiEventCallbacks;
13995 </example>
13996 See <internallink id="jvmtiEventCallbacks">event callbacks</internallink>
13997 for the complete structure.
13998 <p/>
13999 Where, for example, the VM initialization callback is defined:
14000 <example>
14001 typedef void (JNICALL *jvmtiEventVMInit)
14002 (jvmtiEnv *jvmti_env,
14003 JNIEnv* jni_env,
14004 jthread thread);
14005 </example>
14006 See the individual events for the callback function definition.
14007 </description>
14008 </basetype>
14009 <basetype id="jniNativeInterface">
14010 <definition>typedef struct JNINativeInterface_ jniNativeInterface;</definition>
14011 <description>
14012 Typedef for the JNI function table <code>JNINativeInterface</code>
14013 defined in the
14014 <externallink id="jni/functions.html#interface-function-table">
14015 JNI Specification</externallink>.
14016 The JNI reference implementation defines this with an underscore.
14017 </description>
14018 </basetype>
14019 </basetypes>
14020
14021 </datasection>
14022
14023 <issuessection label="Issues">
14024 <intro id="suspendRequired" label="Resolved Issue: Suspend - Required or Automatic">
14025 JVMDI requires that the agent suspend threads before calling
14026 certain sensitive functions. JVMPI requires garbage collection to be
14027 disabled before calling certain sensitive functions.
14028 It was suggested that rather than have this requirement, that
14029 VM place itself in a suitable state before performing an
14030 operation. This makes considerable sense since each VM
14031 knows its requirements and can most easily arrange a
14032 safe state.
14033 <p/>
14034 The ability to externally suspend/resume threads will, of
14035 course, remain. The ability to enable/disable garbage collection will not.
14036 <p/>
14037 This issue is resolved--suspend will not
14038 be required. The spec has been updated to reflect this.
14039 </intro>
14040
14041 <intro id="stackSampling" label="Resolved Issue: Call Stack Sampling">
14042 There are a variety of approaches to sampling call stacks.
14043 The biggest bifurcation is between VM controlled and agent
14044 controlled.
14045 <p/>
14046 This issue is resolved--agent controlled
14047 sampling will be the approach.
14048 </intro>
14049
14050 <intro id="threadRepresentation" label="Resolved Issue: Thread Representation">
14051 JVMDI represents threads as jthread. JVMPI primarily
14052 uses JNIEnv* to represent threads.
14053 <p/>
14054 The Expert Group has chosen jthread as the representation
14055 for threads in <jvmti/>.
14056 JNIEnv* is sent by
14057 events since it is needed to JNI functions. JNIEnv, per the
14058 JNI spec, are not supposed to be used outside their thread.
14059 </intro>
14060
14061 <intro id="design" label="Resolved Issue: Method Representation">
14062 The JNI spec allows an implementation to depend on jclass/jmethodID
14063 pairs, rather than simply a jmethodID, to reference a method.
14064 JVMDI, for consistency, choose the same representation.
14065 JVMPI, however, specifies that a jmethodID alone maps to a
14066 method. Both of the Sun <tm>J2SE</tm> virtual machines (Classic and <tm>HotSpot</tm>) store
14067 pointers in jmethodIDs, and as a result, a jmethodID is sufficient.
14068 In fact, any JVM implementation that supports JVMPI must have
14069 such a representation.
14070 <jvmti/> will use jmethodID as a unique representation of a method
14071 (no jclass is used).
14072 There should be efficiency gains, particularly in
14073 functionality like stack dumping, to this representation.
14074 <p/>
14075 Note that fields were not used in JVMPI and that the access profile
14076 of fields differs from methods--for implementation efficiency
14077 reasons, a jclass/jfieldID pair will still be needed for field
14078 reference.
14079 </intro>
14080
14081 <intro id="localReferenceIssue" label="Resolved Issue: Local References">
14082 Functions return local references.
14083 </intro>
14084
14085 <intro id="frameRep" label="Resolved Issue: Representation of frames">
14086 In JVMDI, a frame ID is used to represent a frame. Problem with this
14087 is that a VM must track when a frame becomes invalid, a far better
14088 approach, and the one used in <jvmti/>, is to reference frames by depth.
14089 </intro>
14090
14091 <intro id="requiredCapabilities" label="Issue: Required Capabilities">
14092 Currently, having a required capabilities means that the functionality
14093 is optional. Capabilities are useful even for required functionality
14094 since they can inform the VM is needed set-up. Thus, there should be
14095 a set of capabilities that a conformant implementation must provide
14096 (if requested during Agent_OnLoad).
14097 </intro>
14098
14099 <intro id="taghint" label="Proposal: add tag hint function">
14100 A hint of the percentage of objects that will be tagged would
14101 help the VM pick a good implementation.
14102 </intro>
14103
14104 <intro id="moreMonitorQueries" label="Request: More Monitor Quires">
14105 How difficult or easy would be to extend the monitor_info category to include
14106 <pre>
14107 - current number of monitors
14108 - enumeration of monitors
14109 - enumeration of threads waiting on a given monitor
14110 </pre>
14111 The reason for my question is the fact that current get_monitor_info support
14112 requires the agent to specify a given thread to get the info which is probably
14113 OK in the profiling/debugging space, while in the monitoring space the agent
14114 could be watching the monitor list and then decide which thread to ask for
14115 the info. You might ask why is this important for monitoring .... I think it
14116 can aid in the detection/prediction of application contention caused by hot-locks.
14117 </intro>
14118 </issuessection>
14119
14120 <changehistory id="ChangeHistory" update="09/05/07">
14121 <intro>
14122 The <jvmti/> specification is an evolving document with major, minor,
14123 and micro version numbers.
14124 A released version of the specification is uniquely identified
14125 by its major and minor version.
14126 The functions, events, and capabilities in this specification
14127 indicate a "Since" value which is the major and minor version in
14128 which it was introduced.
14129 The version of the specification implemented by the VM can
14130 be retrieved at runtime with the <functionlink id="GetVersionNumber"/>
14131 function.
14132 </intro>
14133 <change date="14 Nov 2002">
14134 Converted to XML document.
14135 </change>
14136 <change date="14 Nov 2002">
14137 Elided heap dump functions (for now) since what was there
14138 was wrong.
14139 </change>
14140 <change date="18 Nov 2002">
14141 Added detail throughout.
14142 </change>
14143 <change date="18 Nov 2002">
14144 Changed JVMTI_THREAD_STATUS_RUNNING to JVMTI_THREAD_STATUS_RUNNABLE.
14145 </change>
14146 <change date="19 Nov 2002">
14147 Added AsyncGetStackTrace.
14148 </change>
14149 <change date="19 Nov 2002">
14150 Added jframeID return to GetStackTrace.
14151 </change>
14152 <change date="19 Nov 2002">
14153 Elided GetCurrentFrame and GetCallingFrame functions (for now) since what was there
14154 since they are redundant with GetStackTrace.
14155 </change>
14156 <change date="19 Nov 2002">
14157 Elided ClearAllBreakpoints since it has always been redundant.
14158 </change>
14159 <change date="19 Nov 2002">
14160 Added GetSystemProperties.
14161 </change>
14162 <change date="19 Nov 2002">
14163 Changed the thread local storage functions to use jthread.
14164 </change>
14165 <change date="20 Nov 2002">
14166 Added GetJLocationFormat.
14167 </change>
14168 <change date="22 Nov 2002">
14169 Added events and introductory text.
14170 </change>
14171 <change date="22 Nov 2002">
14172 Cross reference type and constant definitions.
14173 </change>
14174 <change date="24 Nov 2002">
14175 Added DTD.
14176 </change>
14177 <change date="24 Nov 2002">
14178 Added capabilities function section.
14179 </change>
14180 <change date="29 Nov 2002">
14181 Assign capabilities to each function and event.
14182 </change>
14183 <change date="29 Nov 2002">
14184 Add <internallink id="jniIntercept">JNI interception functions</internallink>.
14185 </change>
14186 <change date="30 Nov 2002">
14187 Auto generate SetEventNotificationMode capabilities.
14188 </change>
14189 <change date="30 Nov 2002">
14190 Add <eventlink id="VMObjectAlloc"></eventlink> event.
14191 </change>
14192 <change date="30 Nov 2002">
14193 Add <eventlink id="DynamicCodeGenerated"></eventlink> event.
14194 </change>
14195 <change date="30 Nov 2002">
14196 Add const to declarations.
14197 </change>
14198 <change date="30 Nov 2002">
14199 Change method exit and frame pop to send on exception.
14200 </change>
14201 <change date="1 Dec 2002">
14202 Add ForceGarbageCollection.
14203 </change>
14204 <change date="2 Dec 2002">
14205 Redo Xrun section; clarify GetStackTrace and add example;
14206 Fix width problems; use "agent" consistently.
14207 </change>
14208 <change date="8 Dec 2002">
14209 Remove previous start-up intro.
14210 Add <internallink id="environments"><jvmti/> Environments</internallink>
14211 section.
14212 </change>
14213 <change date="8 Dec 2002">
14214 Add <functionlink id="DisposeEnvironment"></functionlink>.
14215 </change>
14216 <change date="9 Dec 2002">
14217 Numerous minor updates.
14218 </change>
14219 <change date="15 Dec 2002">
14220 Add heap profiling functions added:
14221 get/set annotation, iterate live objects/heap.
14222 Add heap profiling functions place holder added:
14223 heap roots.
14224 Heap profiling event added: object free.
14225 Heap profiling event redesigned: vm object allocation.
14226 Heap profiling event placeholders added: garbage collection start/finish.
14227 Native method bind event added.
14228 </change>
14229 <change date="19 Dec 2002">
14230 Revamp suspend/resume functions.
14231 Add origin information with jvmdi tag.
14232 Misc fixes.
14233 </change>
14234 <change date="24 Dec 2002">
14235 Add semantics to types.
14236 </change>
14237 <change date="27 Dec 2002">
14238 Add local reference section.
14239 Autogenerate parameter descriptions from types.
14240 </change>
14241 <change date="28 Dec 2002">
14242 Document that RunAgentThread sends threadStart.
14243 </change>
14244 <change date="29 Dec 2002">
14245 Remove redundant local ref and dealloc warning.
14246 Convert GetRawMonitorName to allocated buffer.
14247 Add GenerateEvents.
14248 </change>
14249 <change date="30 Dec 2002">
14250 Make raw monitors a type and rename to "jrawMonitorID".
14251 </change>
14252 <change date="1 Jan 2003">
14253 Include origin information.
14254 Clean-up JVMDI issue references.
14255 Remove Deallocate warnings which are now automatically generated.
14256 </change>
14257 <change date="2 Jan 2003">
14258 Fix representation issues for jthread.
14259 </change>
14260 <change date="3 Jan 2003">
14261 Make capabilities buffered out to 64 bits - and do it automatically.
14262 </change>
14263 <change date="4 Jan 2003">
14264 Make constants which are enumeration into enum types.
14265 Parameters now of enum type.
14266 Clean-up and index type section.
14267 Replace remaining datadef entities with callback.
14268 </change>
14269 <change date="7 Jan 2003">
14270 Correct GenerateEvents description.
14271 More internal semantics work.
14272 </change>
14273 <change date="9 Jan 2003">
14274 Replace previous GetSystemProperties with two functions
14275 which use allocated information instead fixed.
14276 Add SetSystemProperty.
14277 More internal semantics work.
14278 </change>
14279 <change date="12 Jan 2003">
14280 Add varargs to end of SetEventNotificationMode.
14281 </change>
14282 <change date="20 Jan 2003">
14283 Finish fixing spec to reflect that alloc sizes are jlong.
14284 </change>
14285 <change date="22 Jan 2003">
14286 Allow NULL as RunAgentThread arg.
14287 </change>
14288 <change date="22 Jan 2003">
14289 Fixed names to standardized naming convention
14290 Removed AsyncGetStackTrace.
14291 </change>
14292 <change date="29 Jan 2003">
14293 Since we are using jthread, removed GetThread.
14294 </change>
14295 <change date="31 Jan 2003">
14296 Change GetFieldName to allow NULLs like GetMethodName.
14297 </change>
14298 <change date="29 Feb 2003" version="v40">
14299 Rewrite the introductory text, adding sections on
14300 start-up, environments and bytecode instrumentation.
14301 Change the command line arguments per EG discussions.
14302 Add an introduction to the capabilities section.
14303 Add the extension mechanism category and functions.
14304 Mark for deletion, but clarified anyhow, SuspendAllThreads.
14305 Rename IterateOverLiveObjects to IterateOverReachableObjects and
14306 change the text accordingly.
14307 Clarify IterateOverHeap.
14308 Clarify CompiledMethodLoad.
14309 Discuss prerequisite state for Calling Functions.
14310 Clarify SetAllocationHooks.
14311 Added issues ("To be resolved:") through-out.
14312 And so on...
14313 </change>
14314 <change date="6 Mar 2003" version="v41">
14315 Remove struct from the call to GetOwnedMonitorInfo.
14316 Automatically generate most error documentation, remove
14317 (rather broken) hand written error doc.
14318 Better describe capability use (empty initial set).
14319 Add min value to jint params.
14320 Remove the capability can_access_thread_local_storage.
14321 Rename error JVMTI_ERROR_NOT_IMPLEMENTED to JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
14322 same for *NOT_IMPLEMENTED.
14323 Description fixes.
14324 </change>
14325 <change date="8 Mar 2003" version="v42">
14326 Rename GetClassSignature to GetClassName.
14327 Rename IterateOverClassObjects to IterateOverInstancesOfClass.
14328 Remove GetMaxStack (operand stack isn't used in <jvmti/>).
14329 Description fixes: define launch-time, remove native frame pop
14330 from PopFrame, and assorted clarifications.
14331 </change>
14332 <change date="8 Mar 2003" version="v43">
14333 Fix minor editing problem.
14334 </change>
14335 <change date="10 Mar 2003" version="v44">
14336 Add phase information.
14337 Remap (compact) event numbers.
14338 </change>
14339 <change date="11 Mar 2003" version="v45">
14340 More phase information - allow "any".
14341 Elide raw monitor queries and events.
14342 Minor description fixes.
14343 </change>
14344 <change date="12 Mar 2003" version="v46">
14345 Add GetPhase.
14346 Use "phase" through document.
14347 Elide GetRawMonitorName.
14348 Elide GetObjectMonitors.
14349 </change>
14350 <change date="12 Mar 2003" version="v47">
14351 Fixes from link, XML, and spell checking.
14352 Auto-generate the callback structure.
14353 </change>
14354 <change date="13 Mar 2003" version="v48">
14355 One character XML fix.
14356 </change>
14357 <change date="13 Mar 2003" version="v49">
14358 Change function parameter names to be consistent with
14359 event parameters (fooBarBaz becomes foo_bar_baz).
14360 </change>
14361 <change date="14 Mar 2003" version="v50">
14362 Fix broken link. Fix thread markers.
14363 </change>
14364 <change date="14 Mar 2003" version="v51">
14365 Change constants so they are under 128 to workaround
14366 compiler problems.
14367 </change>
14368 <change date="23 Mar 2003" version="v52">
14369 Overhaul capabilities. Separate GetStackTrace into
14370 GetStackTrace and GetStackFrames.
14371 </change>
14372 <change date="8 Apr 2003" version="v54">
14373 Use depth instead of jframeID to reference frames.
14374 Remove the now irrelevant GetCurrentFrame, GetCallerFrame and GetStackFrames.
14375 Remove frame arg from events.
14376 </change>
14377 <change date="9 Apr 2003" version="v55">
14378 Remove GetObjectWithAnnotation since tests show bufferred approach more efficient.
14379 Add missing annotation_count to GetObjectsWithAnnotations
14380 </change>
14381 <change date="10 Apr 2003" version="v56">
14382 Remove confusing parenthetical statement in GetObjectsWithAnnotations
14383 </change>
14384 <change date="13 Apr 2003" version="v58">
14385 Replace jclass/jmethodID representation of method with simply jmethodID;
14386 Pass JvmtiEnv* as first arg of every event; remove JNIEnv* where inappropriate.
14387 Replace can_access_frames with can_access_local_variables; remove from purely stack access.
14388 Use can_get_synthetic_attribute; fix description.
14389 Clarify that zero length arrays must be deallocated.
14390 Clarify RelinquishCapabilities.
14391 Generalize JVMTI_ERROR_VM_DEAD to JVMTI_ERROR_WRONG_PHASE.
14392 </change>
14393 <change date="27 Apr 2003" version="v59">
14394 Remove lingering indirect references to OBSOLETE_METHOD_ID.
14395 </change>
14396 <change date="4 May 2003" version="v60">
14397 Allow DestroyRawMonitor during OnLoad.
14398 </change>
14399 <change date="7 May 2003" version="v61">
14400 Added not monitor owner error return to DestroyRawMonitor.
14401 </change>
14402 <change date="13 May 2003" version="v62">
14403 Clarify semantics of raw monitors.
14404 Change flags on <code>GetThreadStatus</code>.
14405 <code>GetClassLoader</code> return NULL for the bootstrap class loader.
14406 Add <code>GetClassName</code> issue.
14407 Define local variable signature.
14408 Disallow zero in annotations array of <code>GetObjectsWithAnnotations</code>.
14409 Remove over specification in <code>GetObjectsWithAnnotations</code>.
14410 Elide <code>SetAllocationHooks</code>.
14411 Elide <code>SuspendAllThreads</code>.
14412 </change>
14413 <change date="14 May 2003" version="v63">
14414 Define the data type <code>jvmtiEventCallbacks</code>.
14415 Zero length allocations return NULL.
14416 Keep SetAllocationHooks in JVMDI, but remove from <jvmti/>.
14417 Add JVMTI_THREAD_STATUS_FLAG_INTERRUPTED.
14418 </change>
14419 <change date="15 May 2003" version="v64">
14420 Better wording, per review.
14421 </change>
14422 <change date="15 May 2003" version="v65">
14423 First Alpha.
14424 Make jmethodID and jfieldID unique, jclass not used.
14425 </change>
14426 <change date="27 May 2003" version="v66">
14427 Fix minor XSLT errors.
14428 </change>
14429 <change date="13 June 2003" version="v67">
14430 Undo making jfieldID unique (jmethodID still is).
14431 </change>
14432 <change date="17 June 2003" version="v68">
14433 Changes per June 11th Expert Group meeting --
14434 Overhaul Heap functionality: single callback,
14435 remove GetHeapRoots, add reachable iterators,
14436 and rename "annotation" to "tag".
14437 NULL thread parameter on most functions is current
14438 thread.
14439 Add timers.
14440 Remove ForceExit.
14441 Add GetEnvironmentLocalStorage.
14442 Add verbose flag and event.
14443 Add AddToBootstrapClassLoaderSearch.
14444 Update ClassFileLoadHook.
14445 </change>
14446 <change date="18 June 2003" version="v69">
14447 Clean up issues sections.
14448 Rename GetClassName back to GetClassSignature and
14449 fix description.
14450 Add generic signature to GetClassSignature,
14451 GetFieldSignature, GetMethodSignature, and
14452 GetLocalVariableTable.
14453 Elide EstimateCostOfCapabilities.
14454 Clarify that the system property functions operate
14455 on the VM view of system properties.
14456 Clarify Agent_OnLoad.
14457 Remove "const" from JNIEnv* in events.
14458 Add metadata accessors.
14459 </change>
14460 <change date="18 June 2003" version="v70">
14461 Add start_depth to GetStackTrace.
14462 Move system properties to a new category.
14463 Add GetObjectSize.
14464 Remove "X" from command line flags.
14465 XML, HTML, and spell check corrections.
14466 </change>
14467 <change date="19 June 2003" version="v71">
14468 Fix JVMTI_HEAP_ROOT_THREAD to be 6.
14469 Make each synopsis match the function name.
14470 Fix unclear wording.
14471 </change>
14472 <change date="26 June 2003" version="v72">
14473 SetThreadLocalStorage and SetEnvironmentLocalStorage should allow value
14474 to be set to NULL.
14475 NotifyFramePop, GetFrameLocationm and all the local variable operations
14476 needed to have their wording about frames fixed.
14477 Grammar and clarity need to be fixed throughout.
14478 Capitalization and puntuation need to be consistent.
14479 Need micro version number and masks for accessing major, minor, and micro.
14480 The error code lists should indicate which must be returned by
14481 an implementation.
14482 The command line properties should be visible in the properties functions.
14483 Disallow popping from the current thread.
14484 Allow implementations to return opaque frame error when they cannot pop.
14485 The NativeMethodBind event should be sent during any phase.
14486 The DynamicCodeGenerated event should be sent during any phase.
14487 The following functions should be allowed to operate before VMInit:
14488 Set/GetEnvironmentLocalStorage
14489 GetMethodDeclaringClass
14490 GetClassSignature
14491 GetClassModifiers
14492 IsInterface
14493 IsArrayClass
14494 GetMethodName
14495 GetMethodModifiers
14496 GetMaxLocals
14497 GetArgumentsSize
14498 GetLineNumberTable
14499 GetMethodLocation
14500 IsMethodNative
14501 IsMethodSynthetic.
14502 Other changes (to XSL):
14503 Argument description should show asterisk after not before pointers.
14504 NotifyFramePop, GetFrameLocationm and all the local variable operations
14505 should hsve the NO_MORE_FRAMES error added.
14506 Not alive threads should have a different error return than invalid thread.
14507 </change>
14508 <change date="7 July 2003" version="v73">
14509 VerboseOutput event was missing message parameter.
14510 Minor fix-ups.
14511 </change>
14512 <change date="14 July 2003" version="v74">
14513 Technical Publications Department corrections.
14514 Allow thread and environment local storage to be set to NULL.
14515 </change>
14516 <change date="23 July 2003" version="v75">
14517 Use new Agent_OnLoad rather than overloaded JVM_OnLoad.
14518 Add JNICALL to callbacks (XSL).
14519 Document JNICALL requirement for both events and callbacks (XSL).
14520 Restrict RedefineClasses to methods and attributes.
14521 Elide the VerboseOutput event.
14522 VMObjectAlloc: restrict when event is sent and remove method parameter.
14523 Finish loose ends from Tech Pubs edit.
14524 </change>
14525 <change date="24 July 2003" version="v76">
14526 Change ClassFileLoadHook event to send the class instead of a boolean of redefine.
14527 </change>
14528 <change date="24 July 2003" version="v77">
14529 XML fixes.
14530 Minor text clarifications and corrections.
14531 </change>
14532 <change date="24 July 2003" version="v78">
14533 Remove GetExceptionHandlerTable and GetThrownExceptions from <jvmti/>.
14534 Clarify that stack frames are JVM Spec frames.
14535 Split can_get_source_info into can_get_source_file_name, can_get_line_numbers,
14536 and can_get_source_debug_extension.
14537 PopFrame cannot have a native calling method.
14538 Removed incorrect statement in GetClassloaderClasses
14539 (see <vmspec chapter="4.4"/>).
14540 </change>
14541 <change date="24 July 2003" version="v79">
14542 XML and text fixes.
14543 Move stack frame description into Stack Frame category.
14544 </change>
14545 <change date="26 July 2003" version="v80">
14546 Allow NULL (means bootstrap loader) for GetClassloaderClasses.
14547 Add new heap reference kinds for references from classes.
14548 Add timer information struct and query functions.
14549 Add AvailableProcessors.
14550 Rename GetOtherThreadCpuTime to GetThreadCpuTime.
14551 Explicitly add JVMTI_ERROR_INVALID_THREAD and JVMTI_ERROR_THREAD_NOT_ALIVE
14552 to SetEventNotification mode.
14553 Add initial thread to the VM_INIT event.
14554 Remove platform assumptions from AddToBootstrapClassLoaderSearch.
14555 </change>
14556 <change date="26 July 2003" version="v81">
14557 Grammar and clarity changes per review.
14558 </change>
14559 <change date="27 July 2003" version="v82">
14560 More grammar and clarity changes per review.
14561 Add Agent_OnUnload.
14562 </change>
14563 <change date="28 July 2003" version="v83">
14564 Change return type of Agent_OnUnload to void.
14565 </change>
14566 <change date="28 July 2003" version="v84">
14567 Rename JVMTI_REFERENCE_ARRAY to JVMTI_REFERENCE_ARRAY_ELEMENT.
14568 </change>
14569 <change date="28 July 2003" version="v85">
14570 Steal java.lang.Runtime.availableProcessors() wording for
14571 AvailableProcessors().
14572 Guarantee that zero will never be an event ID.
14573 Remove some issues which are no longer issues.
14574 Per review, rename and more completely document the timer
14575 information functions.
14576 </change>
14577 <change date="29 July 2003" version="v86">
14578 Non-spec visible change to XML controlled implementation:
14579 SetThreadLocalStorage must run in VM mode.
14580 </change>
14581 <change date="5 August 2003" version="0.1.87">
14582 Add GetErrorName.
14583 Add varargs warning to jvmtiExtensionEvent.
14584 Remove "const" on the jvmtiEnv* of jvmtiExtensionEvent.
14585 Remove unused can_get_exception_info capability.
14586 Pass jvmtiEnv* and JNIEnv* to the jvmtiStartFunction.
14587 Fix jvmtiExtensionFunctionInfo.func declared type.
14588 Extension function returns error code.
14589 Use new version numbering.
14590 </change>
14591 <change date="5 August 2003" version="0.2.88">
14592 Remove the ClassUnload event.
14593 </change>
14594 <change date="8 August 2003" version="0.2.89">
14595 Heap reference iterator callbacks return an enum that
14596 allows outgoing object references to be ignored.
14597 Allow JNIEnv as a param type to extension events/functions.
14598 </change>
14599 <change date="15 August 2003" version="0.2.90">
14600 Fix a typo.
14601 </change>
14602 <change date="2 September 2003" version="0.2.91">
14603 Remove all metadata functions: GetClassMetadata,
14604 GetFieldMetadata, and GetMethodMetadata.
14605 </change>
14606 <change date="1 October 2003" version="0.2.92">
14607 Mark the functions Allocate. Deallocate, RawMonitor*,
14608 SetEnvironmentLocalStorage, and GetEnvironmentLocalStorage
14609 as safe for use in heap callbacks and GC events.
14610 </change>
14611 <change date="24 November 2003" version="0.2.93">
14612 Add pass through opaque user data pointer to heap iterate
14613 functions and callbacks.
14614 In the CompiledMethodUnload event, send the code address.
14615 Add GarbageCollectionOccurred event.
14616 Add constant pool reference kind.
14617 Mark the functions CreateRawMonitor and DestroyRawMonitor
14618 as safe for use in heap callbacks and GC events.
14619 Clarify: VMDeath, GetCurrentThreadCpuTimerInfo,
14620 GetThreadCpuTimerInfo, IterateOverReachableObjects,
14621 IterateOverObjectsReachableFromObject, GetTime and
14622 JVMTI_ERROR_NULL_POINTER.
14623 Add missing errors to: GenerateEvents and
14624 AddToBootstrapClassLoaderSearch.
14625 Fix description of ClassFileLoadHook name parameter.
14626 In heap callbacks and GC/ObjectFree events, specify
14627 that only explicitly allowed functions can be called.
14628 Allow GetCurrentThreadCpuTimerInfo, GetCurrentThreadCpuTime,
14629 GetTimerInfo, and GetTime during callback.
14630 Allow calling SetTag/GetTag during the onload phase.
14631 SetEventNotificationMode, add: error attempted inappropriate
14632 thread level control.
14633 Remove jvmtiExceptionHandlerEntry.
14634 Fix handling of native methods on the stack --
14635 location_ptr param of GetFrameLocation, remove
14636 JVMTI_ERROR_OPAQUE_FRAME from GetFrameLocation,
14637 jvmtiFrameInfo.location, and jlocation.
14638 Remove typo (from JVMPI) implying that the MonitorWaited
14639 event is sent on sleep.
14640 </change>
14641 <change date="25 November 2003" version="0.2.94">
14642 Clarifications and typos.
14643 </change>
14644 <change date="3 December 2003" version="0.2.95">
14645 Allow NULL user_data in heap iterators.
14646 </change>
14647 <change date="28 January 2004" version="0.2.97">
14648 Add GetThreadState, deprecate GetThreadStatus.
14649 </change>
14650 <change date="29 January 2004" version="0.2.98">
14651 INVALID_SLOT and TYPE_MISMATCH errors should be optional.
14652 </change>
14653 <change date="12 February 2004" version="0.2.102">
14654 Remove MonitorContendedExit.
14655 Added JNIEnv parameter to VMObjectAlloc.
14656 Clarified definition of class_tag and referrer_index
14657 parameters to heap callbacks.
14658 </change>
14659 <change date="16 Febuary 2004" version="0.2.103">
14660 Document JAVA_TOOL_OPTIONS.
14661 </change>
14662 <change date="17 Febuary 2004" version="0.2.105">
14663 Divide start phase into primordial and start.
14664 Add VMStart event
14665 Change phase associations of functions and events.
14666 </change>
14667 <change date="18 Febuary 2004" version="0.3.6">
14668 Elide deprecated GetThreadStatus.
14669 Bump minor version, subtract 100 from micro version
14670 </change>
14671 <change date="18 Febuary 2004" version="0.3.7">
14672 Document that timer nanosecond values are unsigned.
14673 Clarify text having to do with native methods.
14674 </change>
14675 <change date="19 Febuary 2004" version="0.3.8">
14676 Fix typos.
14677 Remove elided deprecated GetThreadStatus.
14678 </change>
14679 <change date="23 Febuary 2004" version="0.3.9">
14680 Require NotifyFramePop to act on suspended threads.
14681 </change>
14682 <change date="24 Febuary 2004" version="0.3.10">
14683 Add capabilities
14684 (<internallink id="jvmtiCapabilities.can_redefine_any_class"
14685 ><code>can_redefine_any_class</code></internallink>
14686 and
14687 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events"
14688 ><code>can_generate_all_class_hook_events</code></internallink>)
14689 and an error (<errorlink id="JVMTI_ERROR_UNMODIFIABLE_CLASS"></errorlink>)
14690 which allow some classes to be unmodifiable.
14691 </change>
14692 <change date="28 Febuary 2004" version="0.3.11">
14693 Add JVMTI_ERROR_MUST_POSSESS_CAPABILITY to SetEventNotificationMode.
14694 </change>
14695 <change date="8 March 2004" version="0.3.12">
14696 Clarified CompiledMethodUnload so that it is clear the event
14697 may be posted after the class has been unloaded.
14698 </change>
14699 <change date="5 March 2004" version="0.3.13">
14700 Change the size parameter of VMObjectAlloc to jlong to match GetObjectSize.
14701 </change>
14702 <change date="13 March 2004" version="0.3.14">
14703 Added guideline for the use of the JNI FindClass function in event
14704 callback functions.
14705 </change>
14706 <change date="15 March 2004" version="0.3.15">
14707 Add GetAllStackTraces and GetThreadListStackTraces.
14708 </change>
14709 <change date="19 March 2004" version="0.3.16">
14710 ClassLoad and ClassPrepare events can be posted during start phase.
14711 </change>
14712 <change date="25 March 2004" version="0.3.17">
14713 Add JVMTI_ERROR_NATIVE_METHOD to GetLineNumberTable, GetLocalVariableTable,
14714 GetMaxLocals, GetArgumentsSize, GetMethodLocation, GetBytecodes.
14715 </change>
14716 <change date="29 March 2004" version="0.3.18">
14717 Return the timer kind in the timer information structure.
14718 </change>
14719 <change date="31 March 2004" version="0.3.19">
14720 Spec clarifications:
14721 JVMTI_THREAD_STATE_IN_NATIVE might not include JNI or <jvmti/>.
14722 ForceGarbageCollection does not run finalizers.
14723 The context of the specification is the Java platform.
14724 Warn about early instrumentation.
14725 </change>
14726 <change date="1 April 2004" version="0.3.20">
14727 Refinements to the above clarifications and
14728 Clarify that an error returned by Agent_OnLoad terminates the VM.
14729 </change>
14730 <change date="1 April 2004" version="0.3.21">
14731 Array class creation does not generate a class load event.
14732 </change>
14733 <change date="7 April 2004" version="0.3.22">
14734 Align thread state hierarchy more closely with java.lang.Thread.State.
14735 </change>
14736 <change date="12 April 2004" version="0.3.23">
14737 Clarify the documentation of thread state.
14738 </change>
14739 <change date="19 April 2004" version="0.3.24">
14740 Remove GarbageCollectionOccurred event -- can be done by agent.
14741 </change>
14742 <change date="22 April 2004" version="0.3.25">
14743 Define "command-line option".
14744 </change>
14745 <change date="29 April 2004" version="0.3.26">
14746 Describe the intended use of bytecode instrumentation.
14747 Fix description of extension event first parameter.
14748 </change>
14749 <change date="30 April 2004" version="0.3.27">
14750 Clarification and typos.
14751 </change>
14752 <change date="18 May 2004" version="0.3.28">
14753 Remove DataDumpRequest event.
14754 </change>
14755 <change date="18 May 2004" version="0.3.29">
14756 Clarify RawMonitorWait with zero timeout.
14757 Clarify thread state after RunAgentThread.
14758 </change>
14759 <change date="24 May 2004" version="0.3.30">
14760 Clean-up: fix bad/old links, etc.
14761 </change>
14762 <change date="30 May 2004" version="0.3.31">
14763 Clarifications including:
14764 All character strings are modified UTF-8.
14765 Agent thread visibiity.
14766 Meaning of obsolete method version.
14767 Thread invoking heap callbacks,
14768 </change>
14769 <change date="1 June 2004" version="1.0.32">
14770 Bump major.minor version numbers to "1.0".
14771 </change>
14772 <change date="2 June 2004" version="1.0.33">
14773 Clarify interaction between ForceGarbageCollection
14774 and ObjectFree.
14775 </change>
14776 <change date="6 June 2004" version="1.0.34">
14777 Restrict AddToBootstrapClassLoaderSearch and
14778 SetSystemProperty to the OnLoad phase only.
14779 </change>
14780 <change date="11 June 2004" version="1.0.35">
14781 Fix typo in SetTag.
14782 </change>
14783 <change date="18 June 2004" version="1.0.36">
14784 Fix trademarks.
14785 Add missing parameter in example GetThreadState usage.
14786 </change>
14787 <change date="4 August 2004" version="1.0.37">
14788 Copyright updates.
14789 </change>
14790 <change date="5 November 2004" version="1.0.38">
14791 Add missing function table layout.
14792 Add missing description of C++ member function format of functions.
14793 Clarify that name in CFLH can be NULL.
14794 Released as part of <tm>J2SE</tm> 5.0.
14795 </change>
14796 <change date="24 April 2005" version="1.1.47">
14797 Bump major.minor version numbers to "1.1".
14798 Add ForceEarlyReturn* functions.
14799 Add GetOwnedMonitorStackDepthInfo function.
14800 Add GetCurrentThread function.
14801 Add "since" version marker.
14802 Add AddToSystemClassLoaderSearch.
14803 Allow AddToBootstrapClassLoaderSearch be used in live phase.
14804 Fix historic rubbish in the descriptions of the heap_object_callback
14805 parameter of IterateOverHeap and IterateOverInstancesOfClass functions;
14806 disallow NULL for this parameter.
14807 Clarify, correct and make consistent: wording about current thread,
14808 opaque frames and insufficient number of frames in PopFrame.
14809 Consistently use "current frame" rather than "topmost".
14810 Clarify the JVMTI_ERROR_TYPE_MISMATCH errors in GetLocal* and SetLocal*
14811 by making them compatible with those in ForceEarlyReturn*.
14812 Many other clarifications and wording clean ups.
14813 </change>
14814 <change date="25 April 2005" version="1.1.48">
14815 Add GetConstantPool.
14816 Switch references to the first edition of the VM Spec, to the seconds edition.
14817 </change>
14818 <change date="26 April 2005" version="1.1.49">
14819 Clarify minor/major version order in GetConstantPool.
14820 </change>
14821 <change date="26 April 2005" version="1.1.50">
14822 Add SetNativeMethodPrefix and SetNativeMethodPrefixes.
14823 Reassign GetOwnedMonitorStackDepthInfo to position 153.
14824 Break out Class Loader Search in its own documentation category.
14825 Deal with overly long lines in XML source.
14826 </change>
14827 <change date="29 April 2005" version="1.1.51">
14828 Allow agents be started in the live phase.
14829 Added paragraph about deploying agents.
14830 </change>
14831 <change date="30 April 2005" version="1.1.52">
14832 Add specification description to SetNativeMethodPrefix(es).
14833 Better define the conditions on GetConstantPool.
14834 </change>
14835 <change date="30 April 2005" version="1.1.53">
14836 Break out the GetClassVersionNumber function from GetConstantPool.
14837 Clean-up the references to the VM Spec.
14838 </change>
14839 <change date="1 May 2005" version="1.1.54">
14840 Allow SetNativeMethodPrefix(es) in any phase.
14841 Add clarifications about the impact of redefinition on GetConstantPool.
14842 </change>
14843 <change date="2 May 2005" version="1.1.56">
14844 Various clarifications to SetNativeMethodPrefix(es).
14845 </change>
14846 <change date="2 May 2005" version="1.1.57">
14847 Add missing performance warning to the method entry event.
14848 </change>
14849 <change date="5 May 2005" version="1.1.58">
14850 Remove internal JVMDI support.
14851 </change>
14852 <change date="8 May 2005" version="1.1.59">
14853 Add <functionlink id="RetransformClasses"/>.
14854 Revamp the bytecode instrumentation documentation.
14855 Change <functionlink id="IsMethodObsolete"/> to no longer
14856 require the can_redefine_classes capability.
14857 </change>
14858 <change date="11 May 2005" version="1.1.63">
14859 Clarifications for retransformation.
14860 </change>
14861 <change date="11 May 2005" version="1.1.64">
14862 Clarifications for retransformation, per review.
14863 Lock "retransformation (in)capable" at class load enable time.
14864 </change>
14865 <change date="4 June 2005" version="1.1.67">
14866 Add new heap functionity which supports reporting primitive values,
14867 allows setting the referrer tag, and has more powerful filtering:
14868 FollowReferences, IterateThroughHeap, and their associated
14869 callbacks, structs, enums, and constants.
14870 </change>
14871 <change date="4 June 2005" version="1.1.68">
14872 Clarification.
14873 </change>
14874 <change date="6 June 2005" version="1.1.69">
14875 FollowReferences, IterateThroughHeap: Put callbacks in a struct;
14876 Add missing error codes; reduce bits in the visit control flags.
14877 </change>
14878 <change date="14 June 2005" version="1.1.70">
14879 More on new heap functionity: spec clean-up per review.
14880 </change>
14881 <change date="15 June 2005" version="1.1.71">
14882 More on new heap functionity: Rename old heap section to Heap (1.0).
14883 </change>
14884 <change date="21 June 2005" version="1.1.72">
14885 Fix typos.
14886 </change>
14887 <change date="27 June 2005" version="1.1.73">
14888 Make referrer info structure a union.
14889 </change>
14890 <change date="9 September 2005" version="1.1.74">
14891 In new heap functions:
14892 Add missing superclass reference kind.
14893 Use a single scheme for computing field indexes.
14894 Remove outdated references to struct based referrer info.
14895 </change>
14896 <change date="12 September 2005" version="1.1.75">
14897 Don't callback during FollowReferences on frivolous java.lang.Object superclass.
14898 </change>
14899 <change date="13 September 2005" version="1.1.76">
14900 In string primitive callback, length now Unicode length.
14901 In array and string primitive callbacks, value now "const".
14902 Note possible compiler impacts on setting JNI function table.
14903 </change>
14904 <change date="13 September 2005" version="1.1.77">
14905 GetClassVersionNumbers() and GetConstantPool() should return
14906 error on array or primitive class.
14907 </change>
14908 <change date="14 September 2005" version="1.1.78">
14909 Grammar fixes.
14910 </change>
14911 <change date="26 September 2005" version="1.1.79">
14912 Add IsModifiableClass query.
14913 </change>
14914 <change date="9 February 2006" version="1.1.81">
14915 Add referrer_class_tag parameter to jvmtiHeapReferenceCallback.
14916 </change>
14917 <change date="13 February 2006" version="1.1.82">
14918 Doc fixes: update can_redefine_any_class to include retransform.
14919 Clarify that exception events cover all Throwables.
14920 In GetStackTrace, no test is done for start_depth too big if start_depth is zero,
14921 Clarify fields reported in Primitive Field Callback -- static vs instance.
14922 Repair confusing names of heap types, including callback names.
14923 Require consistent usage of stack depth in the face of thread launch methods.
14924 Note incompatibility of <jvmti/> memory management with other systems.
14925 </change>
14926 <change date="14 February 2006" version="1.1.85">
14927 Fix typos and missing renames.
14928 </change>
14929 <change date="13 March 2006" version="1.1.86">
14930 Clarify that jmethodIDs and jfieldIDs can be saved.
14931 Clarify that Iterate Over Instances Of Class includes subclasses.
14932 </change>
14933 <change date="14 March 2006" version="1.1.87">
14934 Better phrasing.
14935 </change>
14936 <change date="16 March 2006" version="1.1.88">
14937 Match the referrer_index for static fields in Object Reference Callback
14938 with the Reference Implementation (and all other known implementations);
14939 that is, make it match the definition for instance fields.
14940 In GetThreadListStackTraces, add JVMTI_ERROR_INVALID_THREAD to cover
14941 an invalid thread in the list; and specify that not started threads
14942 return empty stacks.
14943 </change>
14944 <change date="17 March 2006" version="1.1.89">
14945 Typo.
14946 </change>
14947 <change date="25 March 2006" version="1.1.90">
14948 Typo.
14949 </change>
14950 <change date="6 April 2006" version="1.1.91">
14951 Remove restrictions on AddToBootstrapClassLoaderSearch and
14952 AddToSystemClassLoaderSearch.
14953 </change>
14954 <change date="1 May 2006" version="1.1.93">
14955 Changed spec to return -1 for monitor stack depth for the
14956 implementation which can not determine stack depth.
14957 </change>
14958 <change date="3 May 2006" version="1.1.94">
14959 Corrections for readability and accuracy courtesy of Alan Pratt of IBM.
14960 List the object relationships reported in FollowReferences.
14961 </change>
14962 <change date="5 May 2006" version="1.1.95">
14963 Clarify the object relationships reported in FollowReferences.
14964 </change>
14965 <change date="28 June 2006" version="1.1.98">
14966 Clarify DisposeEnvironment; add warning.
14967 Fix typos in SetLocalXXX "retrieve" => "set".
14968 Clarify that native method prefixes must remain set while used.
14969 Clarify that exactly one Agent_OnXXX is called per agent.
14970 Clarify that library loading is independent from start-up.
14971 Remove ambiguous reference to Agent_OnLoad in the Agent_OnUnload spec.
14972 </change>
14973 <change date="31 July 2006" version="1.1.99">
14974 Clarify the interaction between functions and exceptions.
14975 Clarify and give examples of field indices.
14976 Remove confusing "That is" sentence from MonitorWait and MonitorWaited events.
14977 Update links to point to Java 6.
14978 </change>
14979 <change date="6 August 2006" version="1.1.102">
14980 Add ResourceExhaustedEvent.
14981 </change>
14982 <change date="11 October 2012" version="1.2.2">
14983 Fixed the "HTTP" and "Missing Anchor" errors reported by the LinkCheck tool.
14984 </change>
14985 <change date="19 June 2013" version="1.2.3">
14986 Added support for statically linked agents.
14987 </change>
14988 <change date="13 October 2016" version="9.0.0">
14989 Support for modules:
14990 - The majorversion is 9 now
14991 - The ClassFileLoadHook events are not sent during the primordial phase anymore.
14992 - Allow CompiledMethodLoad events at start phase
14993 - Add new capabilities:
14994 - can_generate_early_vmstart
14995 - can_generate_early_class_hook_events
14996 - Add new functions:
14997 - GetAllModules
14998 - AddModuleReads, AddModuleExports, AddModuleOpens, AddModuleUses, AddModuleProvides
14999 - IsModifiableModule
15000 Clarified can_redefine_any_classes, can_retransform_any_classes and IsModifiableClass API to
15001 disallow some implementation defined classes.
15002 </change>
15003 <change date="12 February 2017" version="9.0.0">
15004 Minor update for GetCurrentThread function:
15005 - The function may return NULL in the start phase if the
15006 can_generate_early_vmstart capability is enabled.
15007 </change>
15008 <change date="7 February 2018" version="11.0.0">
15009 Minor update for new class file NestHost and NestMembers attributes:
15010 - Specify that RedefineClasses and RetransformClasses are not allowed
15011 to change the class file NestHost and NestMembers attributes.
15012 - Add new error JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_ATTRIBUTE_CHANGED
15013 that can be returned by RedefineClasses and RetransformClasses.
15014 </change>
15015 <change date="20 May 2019" version="13.0.0">
15016 Minor spec update for the capability "can_redefine_any_class".
15017 It now says:
15018 "RedefineClasses can be called on any modifiable class. See IsModifiableClass.
15019 (can_redefine_classes must also be set)"
15020 </change>
15021 <change date="5 June 2019" version="13.0.0">
15022 Minor PopFrame spec update:
15023 - The specified thread must be suspended or must be the current thread.
15024 (It was not allowed to be the current thread before.)
15025 </change>
15026 <change date="10 October 2019" version="14.0.0">
15027 Minor update for new class file Record attribute:
15028 - Specify that RedefineClasses and RetransformClasses are not allowed
15029 to change the class file Record attribute.
15030 </change>
15031 </changehistory>
15032
15033 </specification>
15034 <!-- Keep this comment at the end of the file
15035 Local variables:
15036 mode: sgml
15037 sgml-omittag:t
15038 sgml-shorttag:t
15039 sgml-namecase-general:t
15040 sgml-general-insert-case:lower
15041 sgml-minimize-attributes:nil
15042 sgml-always-quote-attributes:t
15043 sgml-indent-step:2
15044 sgml-indent-data:t
15045 sgml-parent-document:nil
15046 sgml-exposed-tags:nil
15047 sgml-local-catalogs:nil
15048 sgml-local-ecat-files:nil
15049 End:
15050 -->