1 <?xml version="1.0" encoding="ISO-8859-1"?>
2 <?xml-stylesheet type="text/xsl" href="jvmti.xsl"?>
3 <!--
4 Copyright (c) 2002, 2017, Oracle and/or its affiliates. All rights reserved.
5 DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6
7 This code is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License version 2 only, as
9 published by the Free Software Foundation.
10
11 This code is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 version 2 for more details (a copy is included in the LICENSE file that
15 accompanied this code).
16
17 You should have received a copy of the GNU General Public License version
18 2 along with this work; if not, write to the Free Software Foundation,
19 Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20
21 Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 or visit www.oracle.com if you need additional information or have any
23 questions.
24 -->
25
26 <!DOCTYPE specification [
27 <!ELEMENT specification (title, intro*, functionsection, errorsection,
28 eventsection, datasection, issuessection, changehistory)>
29 <!ATTLIST specification label CDATA #REQUIRED
30 majorversion CDATA #REQUIRED
31 minorversion CDATA #REQUIRED
32 microversion CDATA #REQUIRED>
33
34 <!ELEMENT title (#PCDATA|jvmti|tm)*>
35 <!ATTLIST title subtitle CDATA #REQUIRED>
36
37 <!ELEMENT intro ANY>
38 <!ATTLIST intro id CDATA #IMPLIED
39 label CDATA "">
40
41 <!ELEMENT functionsection (intro*, category*)>
42 <!ATTLIST functionsection label CDATA #REQUIRED>
43
44 <!ELEMENT category ((intro|typedef|uniontypedef|capabilitiestypedef)*,
45 (function|callback|elide)*)>
46 <!ATTLIST category id CDATA #REQUIRED
47 label CDATA #REQUIRED>
48
49 <!ELEMENT function (synopsis, typedef*, description?, origin,
50 (capabilities|eventcapabilities),
51 parameters, errors)>
52 <!ATTLIST function id CDATA #REQUIRED
53 num CDATA #REQUIRED
54 phase (onload|onloadOnly|start|live|any) #IMPLIED
55 callbacksafe (safe|unsafe) #IMPLIED
56 impl CDATA #IMPLIED
57 hide CDATA #IMPLIED
58 jkernel (yes|no) #IMPLIED
59 since CDATA "1.0">
60
61 <!ELEMENT callback ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
62 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void),
63 synopsis, description?, parameters)>
64 <!ATTLIST callback id CDATA #REQUIRED
65 since CDATA "1.0">
66
67 <!ELEMENT synopsis (#PCDATA|jvmti)*>
68
69 <!ELEMENT typedef (description?, field*)>
70 <!ATTLIST typedef id CDATA #REQUIRED
71 label CDATA #REQUIRED
72 since CDATA "1.0">
73
74 <!ELEMENT uniontypedef (description?, field*)>
75 <!ATTLIST uniontypedef id CDATA #REQUIRED
76 label CDATA #REQUIRED
77 since CDATA "1.0">
78
79 <!ELEMENT field ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
80 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void|allocfieldbuf|inptr|inbuf|outbuf|vmbuf|ptrtype|struct),
81 description)>
82 <!ATTLIST field id CDATA #REQUIRED>
83
84 <!ELEMENT capabilitiestypedef (description?, capabilityfield*)>
85 <!ATTLIST capabilitiestypedef id CDATA #REQUIRED
86 label CDATA #REQUIRED>
87
88 <!ELEMENT capabilityfield (description)>
89 <!ATTLIST capabilityfield id CDATA #REQUIRED
90 disp1 CDATA ""
91 disp2 CDATA ""
92 since CDATA "1.0">
93
94 <!ELEMENT description ANY>
95
96 <!ELEMENT capabilities (required*, capability*)>
97
98 <!ELEMENT eventcapabilities EMPTY>
99
100 <!ELEMENT required ANY>
101 <!ATTLIST required id CDATA #REQUIRED>
102
103 <!ELEMENT capability ANY>
104 <!ATTLIST capability id CDATA #REQUIRED>
105
106 <!ELEMENT parameters (param*)>
107
108 <!ELEMENT param ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
109 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void|varargs|struct|ptrtype|
110 outptr|allocbuf|allocallocbuf|inptr|inbuf|outbuf|vmbuf|agentbuf),
111 description)>
112 <!ATTLIST param id CDATA #REQUIRED>
113
114 <!ELEMENT jmethodID EMPTY>
115 <!ATTLIST jmethodID class CDATA #IMPLIED
116 native CDATA #IMPLIED>
117
118 <!ELEMENT jfieldID EMPTY>
119 <!ATTLIST jfieldID class CDATA #IMPLIED>
120
121 <!ELEMENT jclass EMPTY>
122 <!ATTLIST jclass method CDATA #IMPLIED
123 field CDATA #IMPLIED>
124
125 <!ELEMENT jframeID EMPTY>
126 <!ATTLIST jframeID thread CDATA #IMPLIED>
127
128 <!ELEMENT jrawMonitorID EMPTY>
129
130 <!ELEMENT jthread EMPTY>
131 <!ATTLIST jthread started CDATA #IMPLIED
132 null CDATA #IMPLIED
133 frame CDATA #IMPLIED
134 impl CDATA #IMPLIED>
135
136 <!ELEMENT varargs EMPTY>
137
138 <!ELEMENT jthreadGroup EMPTY>
139 <!ELEMENT jobject EMPTY>
140 <!ELEMENT jvalue EMPTY>
141 <!ELEMENT jchar EMPTY>
142 <!ELEMENT jint EMPTY>
143 <!ATTLIST jint min CDATA #IMPLIED>
144 <!ELEMENT jlong EMPTY>
145 <!ELEMENT jfloat EMPTY>
146 <!ELEMENT jdouble EMPTY>
147 <!ELEMENT jlocation EMPTY>
148 <!ELEMENT jboolean EMPTY>
149 <!ELEMENT char EMPTY>
150 <!ELEMENT uchar EMPTY>
151 <!ELEMENT size_t EMPTY>
152 <!ELEMENT void EMPTY>
153 <!ELEMENT enum (#PCDATA)*>
154 <!ELEMENT struct (#PCDATA)*>
155
156 <!ELEMENT nullok ANY>
157
158 <!ELEMENT ptrtype ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
159 jthreadGroup|jobject|jvalue), nullok?)>
160
161 <!ELEMENT outptr ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
162 jthreadGroup|jobject|jvalue|enum|jchar|jint|jlong|jfloat|jdouble|
163 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
164
165 <!ELEMENT allocbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
166 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
167 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
168 <!ATTLIST allocbuf incount CDATA #IMPLIED
169 outcount CDATA #IMPLIED>
170
171 <!ELEMENT allocallocbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
172 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
173 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
174 <!ATTLIST allocallocbuf incount CDATA #IMPLIED
175 outcount CDATA #IMPLIED>
176
177 <!ELEMENT inptr (struct, nullok?)>
178
179 <!ELEMENT inbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
180 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
181 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
182 <!ATTLIST inbuf incount CDATA #IMPLIED>
183
184 <!ELEMENT outbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
185 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
186 jlocation|jboolean|char|uchar|size_t|void|outbuf), nullok?)>
187 <!ATTLIST outbuf incount CDATA #IMPLIED
188 outcount CDATA #IMPLIED>
189
190 <!ELEMENT vmbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
191 jthreadGroup|jobject|jvalue|enum|jchar|jint|jlong|jfloat|jdouble|
192 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
193 <!ATTLIST vmbuf incount CDATA #IMPLIED
194 outcount CDATA #IMPLIED>
195
196 <!ELEMENT agentbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
197 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
198 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
199 <!ATTLIST agentbuf incount CDATA #IMPLIED
200 outcount CDATA #IMPLIED>
201
202 <!ELEMENT allocfieldbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
203 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
204 jlocation|jboolean|char|uchar|size_t|void))>
205 <!ATTLIST allocfieldbuf outcount CDATA #IMPLIED>
206
207 <!ELEMENT errors (error*)>
208
209 <!ELEMENT error ANY>
210 <!ATTLIST error id CDATA #REQUIRED>
211
212 <!ELEMENT errorsection (intro*, errorcategory*)>
213 <!ATTLIST errorsection label CDATA #REQUIRED>
214
215 <!ELEMENT errorcategory (intro*, errorid*)>
216 <!ATTLIST errorcategory id CDATA #REQUIRED
217 label CDATA #REQUIRED>
218
219 <!ELEMENT errorid ANY>
220 <!ATTLIST errorid id CDATA #REQUIRED
221 num CDATA #REQUIRED>
222
223 <!ELEMENT datasection (intro*, basetypes*)>
224
225 <!ELEMENT basetypes (intro*, basetype*)>
226 <!ATTLIST basetypes id CDATA #REQUIRED
227 label CDATA #REQUIRED>
228
229 <!ELEMENT basetype (definition?,description)>
230 <!ATTLIST basetype id CDATA #REQUIRED>
231
232 <!ELEMENT definition (#PCDATA|jvmti)*>
233
234 <!ELEMENT eventsection (intro*, (event|elide)*)>
235 <!ATTLIST eventsection label CDATA #REQUIRED>
236
237 <!ELEMENT event (description, origin, typedef*, capabilities, parameters)>
238 <!ATTLIST event id CDATA #REQUIRED
239 label CDATA #REQUIRED
240 const CDATA #REQUIRED
241 num CDATA #REQUIRED
242 phase (onload|start|live|any) #IMPLIED
243 filtered (thread|global) #IMPLIED
244 since CDATA "1.0">
245
246 <!ELEMENT issuessection (intro*)>
247 <!ATTLIST issuessection label CDATA #REQUIRED>
248
249 <!ELEMENT changehistory (intro*, change*)>
250 <!ATTLIST changehistory update CDATA #REQUIRED
251 id CDATA #REQUIRED>
252
253 <!ELEMENT change ANY>
254 <!ATTLIST change date CDATA #REQUIRED
255 version CDATA #IMPLIED>
256
257 <!ELEMENT functionlink (#PCDATA|jvmti|code|i|b)*>
258 <!ATTLIST functionlink id CDATA #REQUIRED>
259
260 <!ELEMENT datalink (#PCDATA|jvmti|code|i|b)*>
261 <!ATTLIST datalink id CDATA #REQUIRED>
262
263 <!ELEMENT typelink (#PCDATA|jvmti|code|i|b)*>
264 <!ATTLIST typelink id CDATA #REQUIRED>
265
266 <!ELEMENT fieldlink (#PCDATA|jvmti|code|i|b)*>
267 <!ATTLIST fieldlink id CDATA #REQUIRED
268 struct CDATA #REQUIRED>
269
270 <!ELEMENT paramlink (#PCDATA|jvmti|code|i|b)*>
271 <!ATTLIST paramlink id CDATA #REQUIRED>
272
273 <!ELEMENT eventlink (#PCDATA|jvmti|code|i|b)*>
274 <!ATTLIST eventlink id CDATA #REQUIRED>
275
276 <!ELEMENT errorlink (#PCDATA|jvmti|code|i|b|tm)*>
277 <!ATTLIST errorlink id CDATA #REQUIRED>
278
279 <!ELEMENT externallink (#PCDATA|jvmti|code|i|b|tm)*>
280 <!ATTLIST externallink id CDATA #REQUIRED>
281
282 <!ELEMENT vmspec EMPTY>
283 <!ATTLIST vmspec chapter CDATA #IMPLIED>
284
285 <!ELEMENT internallink (#PCDATA|jvmti|code|i|b)*>
286 <!ATTLIST internallink id CDATA #REQUIRED>
287
288 <!ELEMENT functionphaselist EMPTY>
289 <!ATTLIST functionphaselist phase (onload|onloadOnly|start|live|any) #REQUIRED>
290
291 <!ELEMENT eventphaselist EMPTY>
292 <!ATTLIST eventphaselist phase (onload|start|live|any) #REQUIRED>
293
294 <!ELEMENT issue ANY>
295
296 <!ELEMENT rationale ANY>
297
298 <!ELEMENT todo ANY>
299
300 <!ELEMENT origin (#PCDATA)*>
301
302 <!ELEMENT elide (intro|function|callback|event)*>
303 <!ATTLIST elide why CDATA #IMPLIED>
304
305 <!ELEMENT constants (constant*)>
306 <!ATTLIST constants id CDATA #REQUIRED
307 label CDATA #REQUIRED
308 kind (enum|bits|const) #REQUIRED
309 since CDATA "1.0">
310
311 <!ELEMENT constant ANY>
312 <!ATTLIST constant id CDATA #REQUIRED
313 num CDATA #REQUIRED>
314
315 <!ELEMENT tm (#PCDATA)>
316
317 <!ELEMENT i (#PCDATA|jvmti|tm)*>
318
319 <!ELEMENT b (#PCDATA|jvmti|code)*>
320
321 <!ELEMENT code (#PCDATA|space)*>
322
323 <!ELEMENT pre ANY>
324
325 <!ELEMENT space EMPTY>
326
327 <!ELEMENT jvmti EMPTY>
328
329 <!ELEMENT example (#PCDATA|i)*>
330
331 <!ELEMENT br EMPTY>
332
333 <!ELEMENT p EMPTY>
334
335 <!ELEMENT dl (dt|dd)+>
336
337 <!ELEMENT dd ANY>
338
339 <!ELEMENT dt (#PCDATA|jvmti|code|i|b)*>
340
341 <!ELEMENT table (tr)+>
342
343 <!ELEMENT tr (td|th)*>
344
345 <!ELEMENT td ANY>
346 <!ATTLIST td align (left|right|center) "center">
347
348 <!ELEMENT th ANY>
349 <!ATTLIST th align (left|right|center) "center">
350
351 <!ELEMENT ul (li)+>
352 <!ATTLIST ul type (disc|circle|square) "disc">
353
354 <!ELEMENT li ANY>
355 ]>
356
357 <specification label="JVM(TM) Tool Interface"
358 majorversion="9"
359 minorversion="0"
360 microversion="0">
361 <title subtitle="Version">
362 <tm>JVM</tm> Tool Interface
363 </title>
364
365 <intro id="whatIs" label="What is the JVM Tool Interface?">
366 The <tm>JVM</tm> Tool Interface (<jvmti/>)
367 is a programming interface used by development and monitoring tools.
368 It provides both a way to inspect the state and
369 to control the execution of applications running in the
370 <tm>Java</tm> virtual machine (VM).
371 <p/>
372 <jvmti/> is intended to provide a VM interface for the full breadth of tools
373 that need access to VM state, including but not limited to: profiling,
374 debugging, monitoring, thread analysis, and coverage analysis tools.
375 <p/>
376 <jvmti/> may not be available in all implementations of the <tm>Java</tm> virtual
377 machine.
378 <p/>
379 <jvmti/> is a two-way interface.
380 A client of <jvmti/>, hereafter called an <i>agent</i>,
381 can be notified of
382 interesting occurrences through <internallink id="EventSection">events</internallink>.
383 <jvmti/>
384 can query and control the application through many
385 <internallink id="FunctionSection">functions</internallink>,
386 either in response to events or
387 independent of them.
388 <p/>
389 Agents run in the same process with and communicate directly with
390 the virtual machine executing
391 the application being examined. This communication is
392 through a native interface (<jvmti/>). The native in-process interface allows
393 maximal control with minimal intrusion on the part of a tool.
394 Typically, agents are relatively compact. They can be controlled
395 by a separate process which implements the bulk of a tool's
396 function without interfering with the target application's normal execution.
397 </intro>
398
399 <intro id="architecture" label="Architecture">
400 Tools can be written directly to <jvmti/> or indirectly
401 through higher level interfaces.
402 The Java Platform Debugger Architecture includes <jvmti/>, but also
403 contains higher-level, out-of-process debugger interfaces. The higher-level
404 interfaces are more appropriate than <jvmti/> for many tools.
405 For more information on the Java Platform Debugger Architecture,
406 see the
407 <externallink id="docs/technotes/guides/jpda/architecture.html">Java
408 Platform Debugger Architecture website</externallink>.
409 </intro>
410
411 <intro id="writingAgents" label="Writing Agents">
412 Agents can be written in any native language that supports C
413 language calling conventions and C or C++
414 definitions.
415 <p/>
416 The function, event, data type, and constant definitions needed for
417 using <jvmti/> are defined in the include file <code>jvmti.h</code>.
418 To use these definitions add the <tm>J2SE</tm> include directory
419 to your include path and add
420 <example>
421 #include <jvmti.h>
422 </example>
423 to your source code.
424 </intro>
425
426 <intro id="deployingAgents" label="Deploying Agents">
427 An agent is deployed in a platform specific manner but is typically the
428 platform equivalent of a dynamic library. On the <tm>Windows</tm> operating
429 system, for example, an agent library is a "Dynamic Linked Library" (DLL).
430 On the <tm>Solaris</tm> Operating Environment, an agent library is a shared
431 object (<code>.so</code> file).
432 <p/>
433
434 An agent may be started at VM startup by specifying the agent library
435 name using a <internallink id="starting">command line option</internallink>.
436 Some implementations may support a mechanism to <internallink id="onattach">
437 start agents</internallink> in the live <functionlink id="GetPhase">phase</functionlink>.
438 The details of how this is initiated are implementation specific.
439 </intro>
440
441 <intro id="entry point" label="Statically Linked Agents (since version 1.2.3)">
442
443 A native JVMTI Agent may be <i>statically linked</i> with the VM.
444 The manner in which the library and VM image are combined is
445 implementation-dependent.
446 An agent L whose image has been combined with the VM is defined as
447 <i>statically linked</i> if and only if the agent exports a function
448 called Agent_OnLoad_L.
449 <p/>
450 If a <i>statically linked</i> agent L exports a function called
451 Agent_OnLoad_L and a function called Agent_OnLoad, the Agent_OnLoad
452 function will be ignored.
453 If an agent L is <i>statically linked</i>, an Agent_OnLoad_L
454 function will be invoked with the same arguments and expected return
455 value as specified for the Agent_OnLoad function.
456 An agent L that is <i>statically linked</i> will prohibit an agent of
457 the same name from being loaded dynamically.
458 <p/>
459 The VM will invoke the Agent_OnUnload_L function of the agent, if such
460 a function is exported, at the same point during VM execution as it would
461 have called the dynamic entry point Agent_OnUnLoad. A statically loaded
462 agent cannot be unloaded. The Agent_OnUnload_L function will still be
463 called to do any other agent shutdown related tasks.
464 If a <i>statically linked</i> agent L exports a function called
465 Agent_OnUnLoad_L and a function called Agent_OnUnLoad, the Agent_OnUnLoad
466 function will be ignored.
467 <p/>
468 If an agent L is <i>statically linked</i>, an Agent_OnAttach_L function
469 will be invoked with the same arguments and expected return value as
470 specified for the Agent_OnAttach function.
471 If a <i>statically linked</i> agent L exports a function called
472 Agent_OnAttach_L and a function called Agent_OnAttach, the Agent_OnAttach
473 function will be ignored.
474 </intro>
475
476 <intro id="starting" label="Agent Command Line Options">
477 The term "command-line option" is used below to
478 mean options supplied in the <code>JavaVMInitArgs</code> argument
479 to the <code>JNI_CreateJavaVM</code> function of the JNI
480 Invocation API.
481 <p/>
482 One of the two following
483 command-line options is used on VM startup to
484 properly load and run agents.
485 These arguments identify the library containing
486 the agent as well as an options
487 string to be passed in at startup.
488 <dl>
489 <dt><code>-agentlib:</code><i><agent-lib-name></i><code>=</code><i><options></i></dt>
490 <dd>
491 The name following <code>-agentlib:</code> is the name of the
492 library to load. Lookup of the library, both its full name and location,
493 proceeds in a platform-specific manner.
494 Typically, the <i><agent-lib-name></i> is expanded to an
495 operating system specific file name.
496 The <i><options></i> will be passed to the agent on start-up.
497 For example, if the option
498 <code>-agentlib:foo=opt1,opt2</code> is specified, the VM will attempt to
499 load the shared library <code>foo.dll</code> from the system <code>PATH</code>
500 under <tm>Windows</tm> or <code>libfoo.so</code> from the
501 <code>LD_LIBRARY_PATH</code> under the <tm>Solaris</tm> operating
502 environment.
503 If the agent library is statically linked into the executable
504 then no actual loading takes place.
505 <p/>
506 </dd>
507 <dt><code>-agentpath:</code><i><path-to-agent></i><code>=</code><i><options></i></dt>
508 <dd>
509 The path following <code>-agentpath:</code> is the absolute path from which
510 to load the library.
511 No library name expansion will occur.
512 The <i><options></i> will be passed to the agent on start-up.
513 For example, if the option
514 <code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code> is specified, the VM will attempt to
515 load the shared library <code>c:\myLibs\foo.dll</code>. If the agent
516 library is statically linked into the executable
517 then no actual loading takes place.
518 <p/>
519 </dd>
520 </dl>
521 For a dynamic shared library agent, the start-up routine
522 <internallink id="onload"><code>Agent_OnLoad</code></internallink>
523 in the library will be invoked. If the agent library is statically linked
524 into the executable then the system will attempt to invoke the
525 <code>Agent_OnLoad_<agent-lib-name></code> entry point where
526 <agent-lib-name> is the basename of the
527 agent. In the above example <code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code>,
528 the system will attempt to find and call the <code>Agent_OnLoad_foo</code> start-up routine.
529 <p/>
530 Libraries loaded with <code>-agentlib:</code> or <code>-agentpath:</code>
531 will be searched for JNI native method implementations to facilitate the
532 use of Java programming language code in tools, as is needed for
533 <internallink id="bci">bytecode instrumentation</internallink>.
534 <p/>
535 The agent libraries will be searched after all other libraries have been
536 searched (agents wishing to override or intercept the native method
537 implementations of non-agent methods can use the
538 <eventlink id="NativeMethodBind">NativeMethodBind event</eventlink>).
539 <p/>
540 These switches do the above and nothing more - they do not change the
541 state of the VM or <jvmti/>. No command line options are needed
542 to enable <jvmti/>
543 or aspects of <jvmti/>, this is handled programmatically
544 by the use of
545 <internallink id="capability">capabilities</internallink>.
546 </intro>
547
548 <intro id="startup" label="Agent Start-Up">
549 The VM starts each agent by invoking a start-up function.
550 If the agent is started in the <code>OnLoad</code>
551 <functionlink id="GetPhase">phase</functionlink> the function
552 <internallink id="onload"><code>Agent_OnLoad</code></internallink>
553 or <internallink id="onload"><code>Agent_OnLoad_L</code></internallink>
554 for statically linked agents will be invoked.
555 If the agent is started in the live
556 <functionlink id="GetPhase">phase</functionlink> the function
557 <internallink id="onattach"><code>Agent_OnAttach</code></internallink>
558 or <internallink id="onattach"><code>Agent_OnAttach_L</code></internallink>
559 for statically linked agents will be invoked.
560 Exactly one call to a start-up function is made per agent.
561 </intro>
562
563 <intro id="onload" label="Agent Start-Up (OnLoad phase)">
564 If an agent is started during the <code>OnLoad</code> phase then its
565 agent library must export a start-up function with the following prototype:
566 <example>
567 JNIEXPORT jint JNICALL
568 Agent_OnLoad(JavaVM *vm, char *options, void *reserved)</example>
569 Or for a statically linked agent named 'L':
570 <example>
571 JNIEXPORT jint JNICALL
572 Agent_OnLoad_L(JavaVM *vm, char *options, void *reserved)</example>
573
574 The VM will start the agent by calling this function.
575 It will be called early enough in VM initialization that:
576 <ul>
577 <li><functionlink id="SetSystemProperty">system properties</functionlink>
578 may be set before they have been used in the start-up of the VM</li>
579 <li>the full set of
580 <internallink id="capability">capabilities</internallink>
581 is still available (note that capabilities that configure the VM
582 may only be available at this time--see the
583 <internallink id="capability">Capability function section</internallink>)</li>
584 <li>no bytecodes have executed</li>
585 <li>no classes have been loaded</li>
586 <li>no objects have been created</li>
587 </ul>
588 <p/>
589 The VM will call the <code>Agent_OnLoad</code> or
590 <code>Agent_OnLoad_<agent-lib-name></code> function with
591 <i><options></i> as the second argument -
592 that is, using the command-line option examples,
593 <code>"opt1,opt2"</code> will be passed to the <code>char *options</code>
594 argument of <code>Agent_OnLoad</code>.
595 The <code>options</code> argument is encoded as a
596 <internallink id="mUTF">modified UTF-8</internallink> string.
597 If <i>=<options></i> is not specified,
598 a zero length string is passed to <code>options</code>.
599 The lifespan of the <code>options</code> string is the
600 <code>Agent_OnLoad</code> or <code>Agent_OnLoad_<agent-lib-name></code>
601 call. If needed beyond this time the string or parts of the string must
602 be copied.
603 The period between when <code>Agent_OnLoad</code> is called and when it
604 returns is called the <i>OnLoad phase</i>.
605 Since the VM is not initialized during the OnLoad
606 <functionlink id="GetPhase">phase</functionlink>,
607 the set of allowed operations
608 inside <code>Agent_OnLoad</code> is restricted (see the function descriptions for the
609 functionality available at this time).
610 The agent can safely process the options and set
611 event callbacks with <functionlink id="SetEventCallbacks"></functionlink>. Once
612 the VM initialization event is received
613 (that is, the <eventlink id="VMInit">VMInit</eventlink>
614 callback is invoked), the agent
615 can complete its initialization.
616 <rationale>
617 Early startup is required so that agents can set the desired capabilities,
618 many of which must be set before the VM is initialized.
619 In JVMDI, the -Xdebug command-line option provided
620 very coarse-grain control of capabilities.
621 JVMPI implementations use various tricks to provide a single "JVMPI on" switch.
622 No reasonable command-line
623 option could provide the fine-grain of control required to balance needed capabilities vs
624 performance impact.
625 Early startup is also needed so that agents can control the execution
626 environment - modifying the file system and system properties to install
627 their functionality.
628 </rationale>
629 <p/>
630 The return value from <code>Agent_OnLoad</code> or
631 <code>Agent_OnLoad_<agent-lib-name></code> is used to indicate an error.
632 Any value other than zero indicates an error and causes termination of the VM.
633 </intro>
634
635 <intro id="onattach" label="Agent Start-Up (Live phase)">
636 A VM may support a mechanism that allows agents to be started in the VM during the live
637 <functionlink id="GetPhase">phase</functionlink>. The details of how this is supported,
638 are implementation specific. For example, a tool may use some platform specific mechanism,
639 or implementation specific API, to attach to the running VM, and request it start a given
640 agent.
641 <p/>
642 If an agent is started during the live phase then its agent library
643 must export a start-up function
644 with the following prototype:
645 <example>
646 JNIEXPORT jint JNICALL
647 Agent_OnAttach(JavaVM* vm, char *options, void *reserved)</example>
648 Or for a statically linked agent named 'L':
649 <example>
650 JNIEXPORT jint JNICALL
651 Agent_OnAttach_L(JavaVM* vm, char *options, void *reserved)</example>
652
653 <p/>
654 The VM will start the agent by calling this function.
655 It will be called in the context of a thread
656 that is attached to the VM. The first argument <i><vm></i> is the Java VM.
657 The <i><options></i> argument is the startup options provided to the agent.
658 <i><options></i> is encoded as a <internallink id="mUTF">modified UTF-8
659 </internallink> string.
660 If startup options were not provided, a zero length string is passed to
661 <code>options</code>. The lifespan of the <code>options</code> string is the
662 <code>Agent_OnAttach</code> or <code>Agent_OnAttach_<agent-lib-name></code> call.
663 If needed beyond this time the string or parts of the string must be copied.
664 <p/>
665 Note that some <internallink id="capability">capabilities</internallink>
666 may not be available in the live phase.
667 <p/>
668 The <code>Agent_OnAttach</code> or <code>Agent_OnAttach_<agent-lib-name
669 ></code> function initializes the agent and returns a value
670 to the VM to indicate if an error occurred. Any value other than zero indicates an error.
671 An error does not cause the VM to terminate. Instead the VM ignores the error, or takes
672 some implementation specific action -- for example it might print an error to standard error,
673 or record the error in a system log.
674 </intro>
675
676 <intro id="onunload" label="Agent Shutdown">
677 The library may optionally export a
678 shutdown function with the following prototype:
679 <example>
680 JNIEXPORT void JNICALL
681 Agent_OnUnload(JavaVM *vm)</example>
682 Or for a statically linked agent named 'L':
683 <example>
684 JNIEXPORT void JNICALL
685 Agent_OnUnload_L(JavaVM *vm)</example>
686
687 This function will be called by the VM when the library is about to be unloaded.
688 The library will be unloaded (unless it is statically linked into the
689 executable) and this function will be called if some platform specific
690 mechanism causes the unload (an unload mechanism is not specified in this document)
691 or the library is (in effect) unloaded by the termination of the VM whether through
692 normal termination or VM failure, including start-up failure.
693 Uncontrolled shutdown is, of couse, an exception to this rule.
694 Note the distinction between this function and the
695 <eventlink id="VMDeath">VM Death event</eventlink>: for the VM Death event
696 to be sent, the VM must have run at least to the point of initialization and a valid
697 <jvmti/> environment must exist which has set a callback for VMDeath
698 and enabled the event.
699 None of these are required for <code>Agent_OnUnload</code> or
700 <code>Agent_OnUnload_<agent-lib-name></code> and this function
701 is also called if the library is unloaded for other reasons.
702 In the case that a VM Death event is sent, it will be sent before this
703 function is called (assuming this function is called due to VM termination).
704 This function can be used to clean-up resources allocated by the agent.
705 </intro>
706
707 <intro id="tooloptions" label="JAVA_TOOL_OPTIONS">
708 Since the command-line cannot always be accessed or modified, for example in embedded VMs
709 or simply VMs launched deep within scripts, a <code>JAVA_TOOL_OPTIONS</code> variable is
710 provided so that agents may be launched in these cases.
711 <p/>
712 Platforms which support environment variables or other named strings, may support the
713 <code>JAVA_TOOL_OPTIONS</code> variable. This variable will be broken into options at white-space
714 boundaries. White-space characters include space, tab, carriage-return, new-line,
715 vertical-tab, and form-feed. Sequences of white-space characters are considered
716 equivalent to a single white-space character. No white-space is included in the options
717 unless quoted. Quoting is as follows:
718 <ul>
719 <li>All characters enclosed between a pair of single quote marks (''), except a single
720 quote, are quoted.</li>
721 <li>Double quote characters have no special meaning inside a pair of single quote marks.</li>
722 <li>All characters enclosed between a pair of double quote marks (""), except a double
723 quote, are quoted.</li>
724 <li>Single quote characters have no special meaning inside a pair of double quote marks.</li>
725 <li>A quoted part can start or end anywhere in the variable.</li>
726 <li>White-space characters have no special meaning when quoted -- they are included in
727 the option like any other character and do not mark white-space boundaries.</li>
728 <li>The pair of quote marks is not included in the option.</li>
729 </ul>
730 <code>JNI_CreateJavaVM</code> (in the JNI Invocation API) will prepend these options to the options supplied
731 in its <code>JavaVMInitArgs</code> argument. Platforms may disable this feature in cases where security is
732 a concern; for example, the Reference Implementation disables this feature on Unix systems when
733 the effective user or group ID differs from the real ID.
734 This feature is intended to support the initialization of tools -- specifically including the
735 launching of native or Java programming language agents. Multiple tools may wish to use this
736 feature, so the variable should not be overwritten, instead, options should be appended to
737 the variable. Note that since the variable is processed at the time of the JNI Invocation
738 API create VM call, options processed by a launcher (e.g., VM selection options) will not be handled.
739 </intro>
740
741 <intro id="environments" label="Environments">
742 The <jvmti/> specification supports the use of multiple simultaneous
743 <jvmti/> agents.
744 Each agent has its own <jvmti/> environment.
745 That is, the <jvmti/> state is
746 separate for each agent - changes to one environment do not affect the
747 others. The state of a <jvmti/>
748 environment includes:
749 <ul>
750 <li><functionlink id="SetEventCallbacks">the event callbacks</functionlink></li>
751 <li><functionlink id="SetEventNotificationMode">the set of events which are enabled</functionlink></li>
752 <li><internallink id="capability">the capabilities</internallink></li>
753 <li><internallink id="memory">the memory allocation/deallocation hooks</internallink></li>
754 </ul>
755 Although their <jvmti/> state
756 is separate, agents inspect and modify the shared state
757 of the VM, they also share the native environment in which they execute.
758 As such, an agent can perturb the results of other agents or cause them
759 to fail. It is the responsibility of the agent writer to specify the level
760 of compatibility with other agents. <jvmti/> implementations are not capable
761 of preventing destructive interactions between agents. Techniques to reduce
762 the likelihood of these occurrences are beyond the scope of this document.
763 <p/>
764 An agent creates a <jvmti/> environment
765 by passing a <jvmti/> version
766 as the interface ID to the JNI Invocation API function
767 <externallink id="docs/technotes/guides/jni/spec/invocation.html#GetEnv">
768 <code>GetEnv</code></externallink>.
769 See <internallink id="jvmtiEnvAccess">Accessing <jvmti/> Functions</internallink>
770 for more details on the creation and use of
771 <jvmti/> environments.
772 Typically, <jvmti/> environments are created by calling <code>GetEnv</code> from
773 <internallink id="onload"><code>Agent_OnLoad</code></internallink>.
774 </intro>
775
776 <intro id="bci" label="Bytecode Instrumentation">
777 This interface does not include some events that one might expect in an interface with
778 profiling support. Some examples include object allocation events and full speed
779 method enter and exit events. The interface instead provides support for
780 <i>bytecode instrumentation</i>, the ability to alter the Java virtual machine
781 bytecode instructions which comprise the target program. Typically, these alterations
782 are to add "events" to the code of a method - for example, to add, at the beginning of a method,
783 a call to <code>MyProfiler.methodEntered()</code>.
784 Since the changes are purely additive, they do not modify application
785 state or behavior.
786 Because the inserted agent code is standard bytecodes, the VM can run at full speed,
787 optimizing not only the target program but also the instrumentation. If the
788 instrumentation does not involve switching from bytecode execution, no expensive
789 state transitions are needed. The result is high performance events.
790 This approach also provides complete control to the agent: instrumentation can be
791 restricted to "interesting" portions of the code (e.g., the end user's code) and
792 can be conditional. Instrumentation can run entirely in Java programming language
793 code or can call into the native agent. Instrumentation can simply maintain
794 counters or can statistically sample events.
795 <p/>
796 Instrumentation can be inserted in one of three ways:
797 <ul>
798 <li>
799 Static Instrumentation: The class file is instrumented before it
800 is loaded into the VM - for example, by creating a duplicate directory of
801 <code>*.class</code> files which have been modified to add the instrumentation.
802 This method is extremely awkward and, in general, an agent cannot know
803 the origin of the class files which will be loaded.
804 </li>
805 <li>
806 Load-Time Instrumentation: When a class file is loaded by the VM, the raw
807 bytes of the class file are sent for instrumentation to the agent.
808 The <eventlink id="ClassFileLoadHook"/>
809 event, triggered by the class load,
810 provides this functionality. This mechanism provides efficient
811 and complete access to one-time instrumentation.
812 </li>
813 <li>
814 Dynamic Instrumentation: A class which is already loaded (and possibly
815 even running) is modified. This optional feature is provided by the
816 <eventlink id="ClassFileLoadHook"/> event, triggered by calling the
817 <functionlink id="RetransformClasses"/> function.
818 Classes can be modified multiple times and can be returned to their
819 original state.
820 The mechanism allows instrumentation which changes during the
821 course of execution.
822 </li>
823 </ul>
824 <p/>
825 The class modification functionality provided in this interface
826 is intended to provide a mechanism for instrumentation
827 (the <eventlink id="ClassFileLoadHook"/> event
828 and the <functionlink id="RetransformClasses"/> function)
829 and, during development, for fix-and-continue debugging
830 (the <functionlink id="RedefineClasses"/> function).
831 <p/>
832 Care must be taken to avoid perturbing dependencies, especially when
833 instrumenting core classes. For example, an approach to getting notification
834 of every object allocation is to instrument the constructor on
835 <code>Object</code>. Assuming that the constructor is initially
836 empty, the constructor could be changed to:
837 <example>
838 public Object() {
839 MyProfiler.allocationTracker(this);
840 }
841 </example>
842 However, if this change was made using the
843 <eventlink id="ClassFileLoadHook"/>
844 event then this might impact a typical VM as follows:
845 the first created object will call the constructor causing a class load of
846 <code>MyProfiler</code>; which will then cause
847 object creation, and since <code>MyProfiler</code> isn't loaded yet,
848 infinite recursion; resulting in a stack overflow. A refinement of this
849 would be to delay invoking the tracking method until a safe time. For
850 example, <code>trackAllocations</code> could be set in the
851 handler for the <code>VMInit</code> event.
852 <example>
853 static boolean trackAllocations = false;
854
855 public Object() {
856 if (trackAllocations) {
857 MyProfiler.allocationTracker(this);
858 }
859 }
860 </example>
861 <p/>
862 The <functionlink id="SetNativeMethodPrefix"/> allows native methods
863 to be instrumented by the use of wrapper methods.
864 </intro>
865
866 <intro id="bcimodules" label="Bytecode Instrumentation of code in modules">
867 Agents can use the functions <functionlink id="AddModuleReads"/>,
868 <functionlink id="AddModuleExports"/>, <functionlink id="AddModuleOpens"/>,
869 <functionlink id="AddModuleUses"/> and <functionlink id="AddModuleProvides"/>
870 to update a module to expand the set of modules that it reads, the set of
871 packages that it exports or opens to other modules, or the services that it
872 uses and provides.
873 <p/>
874 As an aid to agents that deploy supporting classes on the search path of
875 the bootstrap class loader, or the search path of the class loader that
876 loads the main class, the Java virtual machine arranges for the module
877 of classes transformed by the <eventlink id="ClassFileLoadHook"/> event to
878 read the unnamed module of both class loaders.
879 </intro>
880
881 <intro id="mUTF" label="Modified UTF-8 String Encoding">
882 <jvmti/> uses modified UTF-8 to encode character strings.
883 This is the same encoding used by JNI.
884 Modified UTF-8 differs
885 from standard UTF-8 in the representation of supplementary characters
886 and of the null character. See the
887 <externallink id="docs/technotes/guides/jni/spec/types.html#modified_utf_8_strings">
888 Modified UTF-8 Strings</externallink>
889 section of the JNI specification for details.
890 </intro>
891
892 <intro id="context" label="Specification Context">
893 Since this interface provides access to the state of applications running in the
894 Java virtual machine;
895 terminology refers to the Java platform and not the native
896 platform (unless stated otherwise). For example:
897 <ul>
898 <li>"thread" means Java programming language thread.</li>
899 <li>"stack frame" means Java virtual machine stack frame.</li>
900 <li>"class" means Java programming language class.</li>
901 <li>"heap" means Java virtual machine heap.</li>
902 <li>"monitor" means Java programming language object monitor.</li>
903 </ul>
904 <p/>
905 Sun, Sun Microsystems, the Sun logo, Java, and JVM
906 are trademarks or registered trademarks of Oracle
907 and/or its affiliates, in the U.S. and other countries.
908 </intro>
909
910
911 <functionsection label="Functions">
912 <intro id="jvmtiEnvAccess" label="Accessing Functions">
913 Native code accesses <jvmti/> features
914 by calling <jvmti/> functions.
915 Access to <jvmti/> functions is by use of an interface pointer
916 in the same manner as
917 <externallink id="docs/technotes/guides/jni/spec/design.html">Java
918 Native Interface (JNI) functions</externallink> are accessed.
919 The <jvmti/> interface pointer is called the
920 <i>environment pointer</i>.
921 <p/>
922 An environment pointer is a pointer to an environment and has
923 the type <code>jvmtiEnv*</code>.
924 An environment has information about its <jvmti/> connection.
925 The first value in the environment is a pointer to the function table.
926 The function table is an array of pointers to <jvmti/> functions.
927 Every function pointer is at a predefined offset inside the
928 array.
929 <p/>
930 When used from the C language:
931 double indirection is used to access the functions;
932 the environment pointer provides context and is the first
933 parameter of each function call; for example:
934 <example>
935 jvmtiEnv *jvmti;
936 ...
937 jvmtiError err = (*jvmti)->GetLoadedClasses(jvmti, &class_count, &classes);
938 </example>
939 <p/>
940 When used from the C++ language:
941 functions are accessed as member functions of <code>jvmtiEnv</code>;
942 the environment pointer is not passed to the function call; for example:
943 <example>
944 jvmtiEnv *jvmti;
945 ...
946 jvmtiError err = jvmti->GetLoadedClasses(&class_count, &classes);
947 </example>
948 Unless otherwise stated, all examples and declarations in this
949 specification use the C language.
950 <p/>
951 A <jvmti/> environment can be obtained through the JNI Invocation API
952 <code>GetEnv</code> function:
953 <example>
954 jvmtiEnv *jvmti;
955 ...
956 (*jvm)->GetEnv(jvm, &jvmti, JVMTI_VERSION_1_0);
957 </example>
958 Each call to <code>GetEnv</code>
959 creates a new <jvmti/> connection and thus
960 a new <jvmti/> environment.
961 The <code>version</code> argument of <code>GetEnv</code> must be
962 a <jvmti/> version.
963 The returned environment may have a different version than the
964 requested version but the returned environment must be compatible.
965 <code>GetEnv</code> will return <code>JNI_EVERSION</code> if a
966 compatible version is not available, if <jvmti/> is not supported or
967 <jvmti/> is not supported in the current VM configuration.
968 Other interfaces may be added for creating <jvmti/> environments
969 in specific contexts.
970 Each environment has its own state (for example,
971 <functionlink id="SetEventNotificationMode">desired events</functionlink>,
972 <functionlink id="SetEventCallbacks">event handling functions</functionlink>, and
973 <functionlink id="AddCapabilities">capabilities</functionlink>).
974 An environment is released with
975 <functionlink id="DisposeEnvironment"></functionlink>.
976 Thus, unlike JNI which has one environment per thread, <jvmti/> environments work
977 across threads and are created dynamically.
978 </intro>
979
980 <intro id="functionReturn" label="Function Return Values">
981 <jvmti/> functions always return an
982 <internallink id="ErrorSection">error code</internallink> via the
983 <datalink id="jvmtiError"/> function return value.
984 Some functions can return additional
985 values through pointers provided by the calling function.
986 In some cases, <jvmti/> functions allocate memory that your program must
987 explicitly deallocate. This is indicated in the individual <jvmti/>
988 function descriptions. Empty lists, arrays, sequences, etc are
989 returned as <code>NULL</code>.
990 <p/>
991 In the event that the <jvmti/> function encounters
992 an error (any return value other than <code>JVMTI_ERROR_NONE</code>) the values
993 of memory referenced by argument pointers is undefined, but no memory
994 will have been allocated and no global references will have been allocated.
995 If the error occurs because of invalid input, no action will have occurred.
996 </intro>
997
998 <intro id="refs" label="Managing JNI Object References">
999 <jvmti/> functions identify objects with JNI references
1000 (<datalink id="jobject"/> and <datalink id="jclass"/>)
1001 and their derivatives
1002 (<datalink id="jthread"/> and <datalink id="jthreadGroup"/>).
1003 References passed to
1004 <jvmti/> functions can be either global or local, but they must be
1005 strong references. All references returned by <jvmti/> functions are
1006 local references--these local references are created
1007 during the <jvmti/> call.
1008 Local references are a resource that must be managed (see the
1009 <externallink id="docs/technotes/guides/jni/spec/functions.html#local_references">
1010 JNI Documentation</externallink>).
1011 When threads return from native code all local references
1012 are freed. Note that some threads, including typical
1013 agent threads, will never return from native code.
1014 A thread is ensured the ability to create sixteen local
1015 references without the need for any explicit management.
1016 For threads executing a limited number of <jvmti/> calls before
1017 returning from native code
1018 (for example, threads processing events),
1019 it may be determined that no explicit management
1020 is needed.
1021 However, long running agent threads will need explicit
1022 local reference management--usually with the JNI functions
1023 <code>PushLocalFrame</code> and <code>PopLocalFrame</code>.
1024 Conversely, to preserve references beyond the
1025 return from native code, they must be converted to global references.
1026 These rules do not apply to <datalink id="jmethodID"/> and <datalink id="jfieldID"/>
1027 as they are not <datalink id="jobject"/>s.
1028 </intro>
1029
1030 <intro id="prereqState" label="Prerequisite State for Calling Functions">
1031 Unless the function explicitly states that the agent must bring
1032 a thread or the VM to a particular state (for example, suspended),
1033 the <jvmti/> implementation is responsible for bringing the VM to a
1034 safe and consistent state for performing the function.
1035 </intro>
1036
1037 <intro id="functionsExceptions" label="Exceptions and Functions">
1038 <jvmti/> functions never throw exceptions; error conditions are
1039 communicated via the
1040 <internallink id="functionReturn">function return value</internallink>.
1041 Any existing exception state is preserved across a call to a
1042 <jvmti/> function.
1043 See the
1044 <externallink
1045 id="docs/technotes/guides/jni/spec/design.html#java_exceptions"
1046 >Java Exceptions</externallink>
1047 section of the JNI specification for information on handling exceptions.
1048 </intro>
1049
1050 <category id="memory" label="Memory Management">
1051 <intro>
1052 These functions provide for the allocation and deallocation of
1053 memory used by <jvmti/> functionality and can be used to provide
1054 working memory for agents.
1055 Memory managed by <jvmti/> is not compatible with other memory
1056 allocation libraries and mechanisms.
1057 </intro>
1058
1059 <function id="Allocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="46">
1060 <synopsis>Allocate</synopsis>
1061 <description>
1062 Allocate an area of memory through the <jvmti/> allocator.
1063 The allocated
1064 memory should be freed with <functionlink id="Deallocate"></functionlink>.
1065 </description>
1066 <origin>jvmdi</origin>
1067 <capabilities>
1068 </capabilities>
1069 <parameters>
1070 <param id="size">
1071 <jlong/>
1072 <description>
1073 The number of bytes to allocate.
1074 <rationale>
1075 <code>jlong</code> is used for compatibility with JVMDI.
1076 </rationale>
1077 </description>
1078 </param>
1079 <param id="mem_ptr">
1080 <allocbuf incount="size"><uchar/></allocbuf>
1081 <description>
1082 On return, a pointer to the beginning of the allocated memory.
1083 If <code>size</code> is zero, <code>NULL</code> is returned.
1084 </description>
1085 </param>
1086 </parameters>
1087 <errors>
1088 <error id="JVMTI_ERROR_OUT_OF_MEMORY">
1089 Memory request cannot be honored.
1090 </error>
1091 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
1092 <paramlink id="size"></paramlink> is less than zero.
1093 </error>
1094 </errors>
1095 </function>
1096
1097 <function id="Deallocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="47">
1098 <synopsis>Deallocate</synopsis>
1099 <description>
1100 Deallocate <code>mem</code> using the <jvmti/> allocator.
1101 This function should
1102 be used to deallocate any memory allocated and returned
1103 by a <jvmti/> function
1104 (including memory allocated with <functionlink id="Allocate"></functionlink>).
1105 All allocated memory must be deallocated
1106 or the memory cannot be reclaimed.
1107 </description>
1108 <origin>jvmdi</origin>
1109 <capabilities>
1110 </capabilities>
1111 <parameters>
1112 <param id="mem">
1113 <outbuf>
1114 <uchar/>
1115 <nullok>the call is ignored</nullok>
1116 </outbuf>
1117 <description>
1118 A pointer to the beginning of the allocated memory.
1119 Please ignore "On return, the elements are set."
1120 <todo>keep it from generating "On return, the elements are set"</todo>
1121 </description>
1122 </param>
1123 </parameters>
1124 <errors>
1125 </errors>
1126 </function>
1127 </category>
1128
1129 <category id="threadCategory" label="Thread">
1130 <intro>
1131 </intro>
1132
1133 <function id="GetThreadState" num="17">
1134 <synopsis>Get Thread State</synopsis>
1135 <description>
1136 Get the state of a thread. The state of the thread is represented by the
1137 answers to the hierarchical set of questions below:
1138 <ul type="circle">
1139 <li><i>Alive?</i>
1140 <ul>
1141 <li>Not alive.
1142 <ul type="circle">
1143 <li><i>Why not alive?</i>
1144 <ul>
1145 <li>New.</li>
1146 <li>Terminated (<datalink
1147 id="JVMTI_THREAD_STATE_TERMINATED"><code>JVMTI_THREAD_STATE_TERMINATED</code></datalink>)</li>
1148 </ul>
1149 </li>
1150 </ul>
1151 </li>
1152 <li>Alive (<datalink
1153 id="JVMTI_THREAD_STATE_ALIVE"><code>JVMTI_THREAD_STATE_ALIVE</code></datalink>)
1154 <ul type="circle">
1155 <li><i>Suspended?</i>
1156 <ul>
1157 <li>Suspended (<datalink
1158 id="JVMTI_THREAD_STATE_SUSPENDED"><code>JVMTI_THREAD_STATE_SUSPENDED</code></datalink>)</li>
1159 <li>Not suspended</li>
1160 </ul>
1161 </li>
1162 <li><i>Interrupted?</i>
1163 <ul>
1164 <li>Interrupted (<datalink
1165 id="JVMTI_THREAD_STATE_INTERRUPTED"><code>JVMTI_THREAD_STATE_INTERRUPTED</code></datalink>)</li>
1166 <li>Not interrupted.</li>
1167 </ul>
1168 </li>
1169 <li><i>In native?</i>
1170 <ul>
1171 <li>In native code (<datalink
1172 id="JVMTI_THREAD_STATE_IN_NATIVE"><code>JVMTI_THREAD_STATE_IN_NATIVE</code></datalink>)</li>
1173 <li>In Java programming language code</li>
1174 </ul>
1175 </li>
1176 <li><i>What alive state?</i>
1177 <ul>
1178 <li>Runnable (<datalink
1179 id="JVMTI_THREAD_STATE_RUNNABLE"><code>JVMTI_THREAD_STATE_RUNNABLE</code></datalink>)</li>
1180 <li>Blocked (<datalink
1181 id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER"><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></datalink>)</li>
1182 <li>Waiting (<datalink
1183 id="JVMTI_THREAD_STATE_WAITING"><code>JVMTI_THREAD_STATE_WAITING</code></datalink>)
1184 <ul type="circle">
1185 <li><i>Timed wait?</i>
1186 <ul>
1187 <li>Indefinite (<datalink
1188 id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY"><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></datalink></li>
1189 <li>Timed (<datalink
1190 id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT"><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></datalink>)</li>
1191 </ul>
1192 </li>
1193 <li><i>Why waiting?</i>
1194 <ul>
1195 <li>Object.wait (<datalink
1196 id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT"><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></datalink>)</li>
1197 <li>LockSupport.park (<datalink
1198 id="JVMTI_THREAD_STATE_PARKED"><code>JVMTI_THREAD_STATE_PARKED</code></datalink>)</li>
1199 <li>Sleeping (<datalink
1200 id="JVMTI_THREAD_STATE_SLEEPING"><code>JVMTI_THREAD_STATE_SLEEPING</code></datalink>)</li>
1201 </ul>
1202 </li>
1203 </ul>
1204 </li>
1205 </ul>
1206 </li>
1207 </ul>
1208 </li>
1209 </ul>
1210 </li>
1211 </ul>
1212 <p/>
1213 The answers are represented by the following bit vector.
1214 <constants id="jvmtiThreadState" label="Thread State Flags" kind="bits">
1215 <constant id="JVMTI_THREAD_STATE_ALIVE" num="0x0001">
1216 Thread is alive. Zero if thread is new (not started) or terminated.
1217 </constant>
1218 <constant id="JVMTI_THREAD_STATE_TERMINATED" num="0x0002">
1219 Thread has completed execution.
1220 </constant>
1221 <constant id="JVMTI_THREAD_STATE_RUNNABLE" num="0x0004">
1222 Thread is runnable.
1223 </constant>
1224 <constant id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER" num="0x0400">
1225 Thread is waiting to enter a synchronization block/method or,
1226 after an <code>Object.wait()</code>, waiting to re-enter a
1227 synchronization block/method.
1228 </constant>
1229 <constant id="JVMTI_THREAD_STATE_WAITING" num="0x0080">
1230 Thread is waiting.
1231 </constant>
1232 <constant id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY" num="0x0010">
1233 Thread is waiting without a timeout.
1234 For example, <code>Object.wait()</code>.
1235 </constant>
1236 <constant id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT" num="0x0020">
1237 Thread is waiting with a maximum time to wait specified.
1238 For example, <code>Object.wait(long)</code>.
1239 </constant>
1240 <constant id="JVMTI_THREAD_STATE_SLEEPING" num="0x0040">
1241 Thread is sleeping -- <code>Thread.sleep(long)</code>.
1242 </constant>
1243 <constant id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT" num="0x0100">
1244 Thread is waiting on an object monitor -- <code>Object.wait</code>.
1245 </constant>
1246 <constant id="JVMTI_THREAD_STATE_PARKED" num="0x0200">
1247 Thread is parked, for example: <code>LockSupport.park</code>,
1248 <code>LockSupport.parkUtil</code> and <code>LockSupport.parkNanos</code>.
1249 </constant>
1250 <constant id="JVMTI_THREAD_STATE_SUSPENDED" num="0x100000">
1251 Thread suspended.
1252 <code>java.lang.Thread.suspend()</code>
1253 or a <jvmti/> suspend function
1254 (such as <functionlink id="SuspendThread"></functionlink>)
1255 has been called on the thread. If this bit
1256 is set, the other bits refer to the thread state before suspension.
1257 </constant>
1258 <constant id="JVMTI_THREAD_STATE_INTERRUPTED" num="0x200000">
1259 Thread has been interrupted.
1260 </constant>
1261 <constant id="JVMTI_THREAD_STATE_IN_NATIVE" num="0x400000">
1262 Thread is in native code--that is, a native method is running
1263 which has not called back into the VM or Java programming
1264 language code.
1265 <p/>
1266 This flag is not set when running VM compiled Java programming
1267 language code nor is it set when running VM code or
1268 VM support code. Native VM interface functions, such as JNI and
1269 <jvmti/> functions, may be implemented as VM code.
1270 </constant>
1271 <constant id="JVMTI_THREAD_STATE_VENDOR_1" num="0x10000000">
1272 Defined by VM vendor.
1273 </constant>
1274 <constant id="JVMTI_THREAD_STATE_VENDOR_2" num="0x20000000">
1275 Defined by VM vendor.
1276 </constant>
1277 <constant id="JVMTI_THREAD_STATE_VENDOR_3" num="0x40000000">
1278 Defined by VM vendor.
1279 </constant>
1280 </constants>
1281 The following definitions are used to convert <jvmti/> thread state
1282 to <code>java.lang.Thread.State</code> style states.
1283 <constants id="jvmtiJavaLangThreadState" label="java.lang.Thread.State Conversion Masks" kind="bits">
1284 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_MASK"
1285 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">
1286 Mask the state with this before comparison
1287 </constant>
1288 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_NEW"
1289 num="0">
1290 <code>java.lang.Thread.State.NEW</code>
1291 </constant>
1292 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED"
1293 num="JVMTI_THREAD_STATE_TERMINATED">
1294 <code>java.lang.Thread.State.TERMINATED</code>
1295 </constant>
1296 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE"
1297 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE">
1298 <code>java.lang.Thread.State.RUNNABLE</code>
1299 </constant>
1300 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED"
1301 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER">
1302 <code>java.lang.Thread.State.BLOCKED</code>
1303 </constant>
1304 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_WAITING"
1305 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY">
1306 <code>java.lang.Thread.State.WAITING</code>
1307 </constant>
1308 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING"
1309 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT">
1310 <code>java.lang.Thread.State.TIMED_WAITING</code>
1311 </constant>
1312 </constants>
1313 <b>Rules</b>
1314 <p/>
1315 There can be no more than one answer to a question, although there can be no
1316 answer (because the answer is unknown, does not apply, or none of the answers is
1317 correct). An answer is set only when the enclosing answers match.
1318 That is, no more than one of
1319 <ul type="circle">
1320 <li><code>JVMTI_THREAD_STATE_RUNNABLE</code></li>
1321 <li><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></li>
1322 <li><code>JVMTI_THREAD_STATE_WAITING</code></li>
1323 </ul>
1324 can be set (a <tm>J2SE</tm> compliant implementation will always set
1325 one of these if <code>JVMTI_THREAD_STATE_ALIVE</code> is set).
1326 And if any of these are set, the enclosing answer
1327 <code>JVMTI_THREAD_STATE_ALIVE</code> is set.
1328 No more than one of
1329 <ul type="circle">
1330 <li><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></li>
1331 <li><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></li>
1332 </ul>
1333 can be set (a <tm>J2SE</tm> compliant implementation will always set
1334 one of these if <code>JVMTI_THREAD_STATE_WAITING</code> is set).
1335 And if either is set, the enclosing answers
1336 <code>JVMTI_THREAD_STATE_ALIVE</code> and
1337 <code>JVMTI_THREAD_STATE_WAITING</code> are set.
1338 No more than one of
1339 <ul type="circle">
1340 <li><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></li>
1341 <li><code>JVMTI_THREAD_STATE_PARKED</code></li>
1342 <li><code>JVMTI_THREAD_STATE_SLEEPING</code></li>
1343 </ul>
1344 can be set. And if any of these is set, the enclosing answers
1345 <code>JVMTI_THREAD_STATE_ALIVE</code> and
1346 <code>JVMTI_THREAD_STATE_WAITING</code> are set.
1347 Also, if <code>JVMTI_THREAD_STATE_SLEEPING</code> is set,
1348 then <code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code> is set.
1349 If a state <i>A</i> is implemented using the mechanism of
1350 state <i>B</i> then it is state <i>A</i> which
1351 is returned by this function.
1352 For example, if <code>Thread.sleep(long)</code>
1353 is implemented using <code>Object.wait(long)</code>
1354 then it is still <code>JVMTI_THREAD_STATE_SLEEPING</code>
1355 which is returned.
1356 More than one of
1357 <ul type="circle">
1358 <li><code>JVMTI_THREAD_STATE_SUSPENDED</code></li>
1359 <li><code>JVMTI_THREAD_STATE_INTERRUPTED</code></li>
1360 <li><code>JVMTI_THREAD_STATE_IN_NATIVE</code></li>
1361 </ul>
1362 can be set, but if any is set,
1363 <code>JVMTI_THREAD_STATE_ALIVE</code> is set.
1364 <p/>
1365 And finally,
1366 <code>JVMTI_THREAD_STATE_TERMINATED</code> cannot be set unless
1367 <code>JVMTI_THREAD_STATE_ALIVE</code> is not set.
1368 <p/>
1369 The thread state representation is designed for extension in future versions
1370 of the specification; thread state values should be used accordingly, that is
1371 they should not be used as ordinals.
1372 Most queries can be made by testing a single bit, if use in a switch statement is desired,
1373 the state bits should be masked with the interesting bits.
1374 All bits not defined above are reserved for future use.
1375 A VM, compliant to the current specification, must set reserved bits to zero.
1376 An agent should ignore reserved bits --
1377 they should not be assumed to be zero and thus should not be included in comparisons.
1378 <p/>
1379 <b>Examples</b>
1380 <p/>
1381 Note that the values below exclude reserved and vendor bits.
1382 <p/>
1383 The state of a thread blocked at a <code>synchronized</code>-statement would be:
1384 <example>
1385 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER
1386 </example>
1387 The state of a thread which hasn't started yet would be:
1388 <example>
1389 0
1390 </example>
1391 The state of a thread at a <code>Object.wait(3000)</code> would be:
1392 <example>
1393 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_WAITING +
1394 JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT +
1395 JVMTI_THREAD_STATE_MONITOR_WAITING
1396 </example>
1397 The state of a thread suspended while runnable would be:
1398 <example>
1399 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_RUNNABLE + JVMTI_THREAD_STATE_SUSPENDED
1400 </example>
1401 <p/>
1402 <b>Testing the State</b>
1403 <p/>
1404 In most cases, the thread state can be determined by testing the one bit corresponding
1405 to that question. For example, the code to test if a thread is sleeping:
1406 <example>
1407 jint state;
1408 jvmtiError err;
1409
1410 err = (*jvmti)->GetThreadState(jvmti, thread, &state);
1411 if (err == JVMTI_ERROR_NONE) {
1412 if (state & JVMTI_THREAD_STATE_SLEEPING) { ...
1413 </example>
1414 <p/>
1415 For waiting (that is, in <code>Object.wait</code>, parked, or sleeping) it would be:
1416 <example>
1417 if (state & JVMTI_THREAD_STATE_WAITING) { ...
1418 </example>
1419 For some states, more than one bit will need to be tested as is the case
1420 when testing if a thread has not yet been started:
1421 <example>
1422 if ((state & (JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_TERMINATED)) == 0) { ...
1423 </example>
1424 To distinguish timed from untimed <code>Object.wait</code>:
1425 <example>
1426 if (state & JVMTI_THREAD_STATE_IN_OBJECT_WAIT) {
1427 if (state & JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT) {
1428 printf("in Object.wait(long timeout)\n");
1429 } else {
1430 printf("in Object.wait()\n");
1431 }
1432 }
1433 </example>
1434 <p/>
1435 <b>Relationship to <code>java.lang.Thread.State</code></b>
1436 <p/>
1437 The thread state represented by <code>java.lang.Thread.State</code>
1438 returned from <code>java.lang.Thread.getState()</code> is a subset of the
1439 information returned from this function.
1440 The corresponding <code>java.lang.Thread.State</code> can be determined
1441 by using the provided conversion masks.
1442 For example, this returns the name of the <code>java.lang.Thread.State</code> thread state:
1443 <example>
1444 err = (*jvmti)->GetThreadState(jvmti, thread, &state);
1445 abortOnError(err);
1446 switch (state & JVMTI_JAVA_LANG_THREAD_STATE_MASK) {
1447 case JVMTI_JAVA_LANG_THREAD_STATE_NEW:
1448 return "NEW";
1449 case JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED:
1450 return "TERMINATED";
1451 case JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE:
1452 return "RUNNABLE";
1453 case JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED:
1454 return "BLOCKED";
1455 case JVMTI_JAVA_LANG_THREAD_STATE_WAITING:
1456 return "WAITING";
1457 case JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING:
1458 return "TIMED_WAITING";
1459 }
1460 </example>
1461 </description>
1462 <origin>new</origin>
1463 <capabilities>
1464 </capabilities>
1465 <parameters>
1466 <param id="thread">
1467 <jthread null="current" started="maybe" impl="noconvert"/>
1468 <description>
1469 The thread to query.
1470 </description>
1471 </param>
1472 <param id="thread_state_ptr">
1473 <outptr><jint/></outptr>
1474 <description>
1475 On return, points to state flags,
1476 as defined by the <internallink id="jvmtiThreadState">Thread State Flags</internallink>.
1477 </description>
1478 </param>
1479 </parameters>
1480 <errors>
1481 </errors>
1482 </function>
1483
1484 <function id="GetCurrentThread" phase="start" num="18" since="1.1">
1485 <synopsis>Get Current Thread</synopsis>
1486 <description>
1487 Get the current thread.
1488 The current thread is the Java programming language thread which has called the function.
1489 The function may return <code>NULL</code> in the start phase if the
1490 <internallink id="jvmtiCapabilities.can_generate_early_vmstart">
1491 <code>can_generate_early_vmstart</code></internallink> capability is enabled
1492 and the <code>java.lang.Thread</code> class has not been initialized yet.
1493 <p/>
1494 Note that most <jvmti/> functions that take a thread
1495 as an argument will accept <code>NULL</code> to mean
1496 the current thread.
1497 </description>
1498 <origin>new</origin>
1499 <capabilities>
1500 </capabilities>
1501 <parameters>
1502 <param id="thread_ptr">
1503 <outptr><jthread/></outptr>
1504 <description>
1505 On return, points to the current thread, or <code>NULL</code>.
1506 </description>
1507 </param>
1508 </parameters>
1509 <errors>
1510 </errors>
1511 </function>
1512
1513 <function id="GetAllThreads" num="4">
1514 <synopsis>Get All Threads</synopsis>
1515 <description>
1516 Get all live threads.
1517 The threads are Java programming language threads;
1518 that is, threads that are attached to the VM.
1519 A thread is live if <code>java.lang.Thread.isAlive()</code>
1520 would return <code>true</code>, that is, the thread has
1521 been started and has not yet died.
1522 The universe of threads is determined by the context of the <jvmti/>
1523 environment, which typically is all threads attached to the VM.
1524 Note that this includes <jvmti/> agent threads
1525 (see <functionlink id="RunAgentThread"/>).
1526 </description>
1527 <origin>jvmdi</origin>
1528 <capabilities>
1529 </capabilities>
1530 <parameters>
1531 <param id="threads_count_ptr">
1532 <outptr><jint/></outptr>
1533 <description>
1534 On return, points to the number of running threads.
1535 </description>
1536 </param>
1537 <param id="threads_ptr">
1538 <allocbuf outcount="threads_count_ptr"><jthread/></allocbuf>
1539 <description>
1540 On return, points to an array of references, one
1541 for each running thread.
1542 </description>
1543 </param>
1544 </parameters>
1545 <errors>
1546 </errors>
1547 </function>
1548
1549 <function id="SuspendThread" num="5">
1550 <synopsis>Suspend Thread</synopsis>
1551 <description>
1552 Suspend the specified thread. If the calling thread is specified,
1553 this function will not return until some other thread calls
1554 <functionlink id="ResumeThread"></functionlink>.
1555 If the thread is currently suspended, this function
1556 does nothing and returns an error.
1557 </description>
1558 <origin>jvmdi</origin>
1559 <capabilities>
1560 <required id="can_suspend"></required>
1561 </capabilities>
1562 <parameters>
1563 <param id="thread">
1564 <jthread null="current"/>
1565 <description>
1566 The thread to suspend.
1567 </description>
1568 </param>
1569 </parameters>
1570 <errors>
1571 <error id="JVMTI_ERROR_THREAD_SUSPENDED">
1572 Thread already suspended.
1573 </error>
1574 </errors>
1575 </function>
1576
1577 <elide>
1578 <function id="SuspendAllThreads" num="101">
1579 <synopsis>Suspend All Threads</synopsis>
1580 <description>
1581 <issue>
1582 There has been no explicit call for this function, and it will
1583 thus be removed if there is no interest.
1584 </issue>
1585 Suspend all live threads except:
1586 <ul>
1587 <li>already suspended threads</li>
1588 <li>those listed in <paramlink id="except_list"></paramlink></li>
1589 <li>certain system (non application) threads, as determined
1590 by the VM implementation</li>
1591 </ul>
1592 The threads are Java programming language threads;
1593 native threads which are not attached to the VM are not
1594 Java programming language threads.
1595 A thread is live if <code>java.lang.Thread.isAlive()</code>
1596 would return <code>true</code>, that is, the thread has
1597 been started and has not yet died.
1598 The universe of threads is determined
1599 by the context of the <jvmti/>
1600 environment, which, typically, is all threads attached to the VM,
1601 except critical VM internal threads and <jvmti/> agent threads
1602 (see <functionlink id="RunAgentThread"/>).
1603 <p/>
1604 If the calling thread is specified,
1605 all other threads are suspended first then the caller thread is suspended -
1606 this function will not return until some other thread calls
1607 <functionlink id="ResumeThread"></functionlink>.
1608 <p/>
1609 The list of actually
1610 suspended threads is returned in
1611 <paramlink id="suspended_list_ptr"></paramlink>.
1612 Suspension is as defined in <functionlink id="SuspendThread"></functionlink>.
1613 <functionlink id="ResumeThreadList"></functionlink>
1614 can be used to resume the suspended threads.
1615 </description>
1616 <origin>new</origin>
1617 <capabilities>
1618 <required id="can_suspend"></required>
1619 </capabilities>
1620 <parameters>
1621 <param id="except_count">
1622 <jint min="0"/>
1623 <description>
1624 The number of threads in the list of threads not to be suspended.
1625 </description>
1626 </param>
1627 <param id="except_list">
1628 <inbuf incount="except_count">
1629 <jthread/>
1630 <nullok>not an error if <code>except_count == 0</code></nullok>
1631 </inbuf>
1632 <description>
1633 The list of threads not to be suspended.
1634 </description>
1635 </param>
1636 <param id="suspended_count_ptr">
1637 <outptr><jint/></outptr>
1638 <description>
1639 On return, points to the number of threads suspended by this call.
1640 </description>
1641 </param>
1642 <param id="suspended_list_ptr">
1643 <allocbuf outcount="suspended_count_ptr"><jthread/></allocbuf>
1644 <description>
1645 On return, points to an array of references, one
1646 for each thread suspended.
1647 </description>
1648 </param>
1649 </parameters>
1650 <errors>
1651 <error id="JVMTI_ERROR_INVALID_THREAD">
1652 A thread in <paramlink id="except_list"></paramlink> was invalid.
1653 </error>
1654 <error id="JVMTI_ERROR_NULL_POINTER">
1655 Both <paramlink id="except_list"></paramlink> was <code>NULL</code>
1656 and <paramlink id="except_count"></paramlink> was non-zero.
1657 </error>
1658 </errors>
1659 </function>
1660 </elide>
1661
1662 <function id="SuspendThreadList" num="92">
1663 <synopsis>Suspend Thread List</synopsis>
1664 <description>
1665 Suspend the <paramlink id="request_count"></paramlink>
1666 threads specified in the
1667 <paramlink id="request_list"></paramlink> array.
1668 Threads may be resumed with
1669 <functionlink id="ResumeThreadList"></functionlink> or
1670 <functionlink id="ResumeThread"></functionlink>.
1671 If the calling thread is specified in the
1672 <paramlink id="request_list"></paramlink> array, this function will
1673 not return until some other thread resumes it.
1674 Errors encountered in the suspension of a thread
1675 are returned in the <paramlink id="results"></paramlink>
1676 array, <b>not</b> in the return value of this function.
1677 Threads that are currently suspended do not change state.
1678 </description>
1679 <origin>jvmdi</origin>
1680 <capabilities>
1681 <required id="can_suspend"></required>
1682 </capabilities>
1683 <parameters>
1684 <param id="request_count">
1685 <jint min="0"/>
1686 <description>
1687 The number of threads to suspend.
1688 </description>
1689 </param>
1690 <param id="request_list">
1691 <inbuf incount="request_count"><jthread/></inbuf>
1692 <description>
1693 The list of threads to suspend.
1694 </description>
1695 </param>
1696 <param id="results">
1697 <outbuf incount="request_count"><enum>jvmtiError</enum></outbuf>
1698 <description>
1699 An agent supplied array of
1700 <paramlink id="request_count"></paramlink> elements.
1701 On return, filled with the error code for
1702 the suspend of the corresponding thread.
1703 The error code will be
1704 <errorlink id="JVMTI_ERROR_NONE"></errorlink>
1705 if the thread was suspended by this call.
1706 Possible error codes are those specified
1707 for <functionlink id="SuspendThread"></functionlink>.
1708 </description>
1709 </param>
1710 </parameters>
1711 <errors>
1712 </errors>
1713 </function>
1714
1715 <function id="ResumeThread" num="6">
1716 <synopsis>Resume Thread</synopsis>
1717 <description>
1718 Resume a suspended thread.
1719 Any threads currently suspended through
1720 a <jvmti/> suspend function (eg.
1721 <functionlink id="SuspendThread"></functionlink>)
1722 or <code>java.lang.Thread.suspend()</code>
1723 will resume execution;
1724 all other threads are unaffected.
1725 </description>
1726 <origin>jvmdi</origin>
1727 <capabilities>
1728 <required id="can_suspend"></required>
1729 </capabilities>
1730 <parameters>
1731 <param id="thread">
1732 <jthread/>
1733 <description>
1734 The thread to resume.
1735 </description>
1736 </param>
1737 </parameters>
1738 <errors>
1739 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
1740 Thread was not suspended.
1741 </error>
1742 <error id="JVMTI_ERROR_INVALID_TYPESTATE">
1743 The state of the thread has been modified, and is now inconsistent.
1744 </error>
1745 </errors>
1746 </function>
1747
1748 <function id="ResumeThreadList" num="93">
1749 <synopsis>Resume Thread List</synopsis>
1750 <description>
1751 Resume the <paramlink id="request_count"></paramlink>
1752 threads specified in the
1753 <paramlink id="request_list"></paramlink> array.
1754 Any thread suspended through
1755 a <jvmti/> suspend function (eg.
1756 <functionlink id="SuspendThreadList"></functionlink>)
1757 or <code>java.lang.Thread.suspend()</code>
1758 will resume execution.
1759 </description>
1760 <origin>jvmdi</origin>
1761 <capabilities>
1762 <required id="can_suspend"></required>
1763 </capabilities>
1764 <parameters>
1765 <param id="request_count">
1766 <jint min="0"/>
1767 <description>
1768 The number of threads to resume.
1769 </description>
1770 </param>
1771 <param id="request_list">
1772 <inbuf incount="request_count"><jthread/></inbuf>
1773 <description>
1774 The threads to resume.
1775 </description>
1776 </param>
1777 <param id="results">
1778 <outbuf incount="request_count"><enum>jvmtiError</enum></outbuf>
1779 <description>
1780 An agent supplied array of
1781 <paramlink id="request_count"></paramlink> elements.
1782 On return, filled with the error code for
1783 the resume of the corresponding thread.
1784 The error code will be
1785 <errorlink id="JVMTI_ERROR_NONE"></errorlink>
1786 if the thread was suspended by this call.
1787 Possible error codes are those specified
1788 for <functionlink id="ResumeThread"></functionlink>.
1789 </description>
1790 </param>
1791 </parameters>
1792 <errors>
1793 </errors>
1794 </function>
1795
1796 <function id="StopThread" num="7">
1797 <synopsis>Stop Thread</synopsis>
1798 <description>
1799 Send the specified asynchronous exception to the specified thread
1800 (similar to <code>java.lang.Thread.stop</code>).
1801 Normally, this function is used to kill the specified thread with an
1802 instance of the exception <code>ThreadDeath</code>.
1803 </description>
1804 <origin>jvmdi</origin>
1805 <capabilities>
1806 <required id="can_signal_thread"></required>
1807 </capabilities>
1808 <parameters>
1809 <param id="thread">
1810 <jthread/>
1811 <description>
1812 The thread to stop.
1813 </description>
1814 </param>
1815 <param id="exception">
1816 <jobject/>
1817 <description>
1818 The asynchronous exception object.
1819 </description>
1820 </param>
1821 </parameters>
1822 <errors>
1823 </errors>
1824 </function>
1825
1826 <function id="InterruptThread" num="8">
1827 <synopsis>Interrupt Thread</synopsis>
1828 <description>
1829 Interrupt the specified thread
1830 (similar to <code>java.lang.Thread.interrupt</code>).
1831 </description>
1832 <origin>jvmdi</origin>
1833 <capabilities>
1834 <required id="can_signal_thread"></required>
1835 </capabilities>
1836 <parameters>
1837 <param id="thread">
1838 <jthread impl="noconvert"/>
1839 <description>
1840 The thread to interrupt.
1841 </description>
1842 </param>
1843 </parameters>
1844 <errors>
1845 </errors>
1846 </function>
1847
1848 <function id="GetThreadInfo" num="9">
1849 <synopsis>Get Thread Info</synopsis>
1850 <typedef id="jvmtiThreadInfo" label="Thread information structure">
1851 <field id="name">
1852 <allocfieldbuf><char/></allocfieldbuf>
1853 <description>
1854 The thread name, encoded as a
1855 <internallink id="mUTF">modified UTF-8</internallink> string.
1856 </description>
1857 </field>
1858 <field id="priority">
1859 <jint/>
1860 <description>
1861 The thread priority. See the thread priority constants:
1862 <datalink id="jvmtiThreadPriority"></datalink>.
1863 </description>
1864 </field>
1865 <field id="is_daemon">
1866 <jboolean/>
1867 <description>
1868 Is this a daemon thread?
1869 </description>
1870 </field>
1871 <field id="thread_group">
1872 <jthreadGroup/>
1873 <description>
1874 The thread group to which this thread belongs.
1875 <code>NULL</code> if the thread has died.
1876 </description>
1877 </field>
1878 <field id="context_class_loader">
1879 <jobject/>
1880 <description>
1881 The context class loader associated with this thread.
1882 </description>
1883 </field>
1884 </typedef>
1885 <description>
1886 Get thread information. The fields of the <datalink id="jvmtiThreadInfo"/> structure
1887 are filled in with details of the specified thread.
1888 </description>
1889 <origin>jvmdi</origin>
1890 <capabilities>
1891 </capabilities>
1892 <parameters>
1893 <param id="thread">
1894 <jthread null="current" impl="noconvert" started="maybe"/>
1895 <description>
1896 The thread to query.
1897 </description>
1898 </param>
1899 <param id="info_ptr">
1900 <outptr><struct>jvmtiThreadInfo</struct></outptr>
1901 <description>
1902 On return, filled with information describing the specified thread.
1903 </description>
1904 </param>
1905 </parameters>
1906 <errors>
1907 </errors>
1908 </function>
1909
1910 <function id="GetOwnedMonitorInfo" num="10">
1911 <synopsis>Get Owned Monitor Info</synopsis>
1912 <description>
1913 Get information about the monitors owned by the
1914 specified thread.
1915 </description>
1916 <origin>jvmdiClone</origin>
1917 <capabilities>
1918 <required id="can_get_owned_monitor_info"></required>
1919 </capabilities>
1920 <parameters>
1921 <param id="thread">
1922 <jthread null="current"/>
1923 <description>
1924 The thread to query.
1925 </description>
1926 </param>
1927 <param id="owned_monitor_count_ptr">
1928 <outptr><jint/></outptr>
1929 <description>
1930 The number of monitors returned.
1931 </description>
1932 </param>
1933 <param id="owned_monitors_ptr">
1934 <allocbuf outcount="owned_monitor_count_ptr"><jobject/></allocbuf>
1935 <description>
1936 The array of owned monitors.
1937 </description>
1938 </param>
1939 </parameters>
1940 <errors>
1941 </errors>
1942 </function>
1943
1944 <function id="GetOwnedMonitorStackDepthInfo" num="153" since="1.1">
1945 <synopsis>Get Owned Monitor Stack Depth Info</synopsis>
1946 <typedef id="jvmtiMonitorStackDepthInfo"
1947 label="Monitor stack depth information structure">
1948 <field id="monitor">
1949 <jobject/>
1950 <description>
1951 The owned monitor.
1952 </description>
1953 </field>
1954 <field id="stack_depth">
1955 <jint/>
1956 <description>
1957 The stack depth. Corresponds to the stack depth used in the
1958 <internallink id="stack">Stack Frame functions</internallink>.
1959 That is, zero is the current frame, one is the frame which
1960 called the current frame. And it is negative one if the
1961 implementation cannot determine the stack depth (e.g., for
1962 monitors acquired by JNI <code>MonitorEnter</code>).
1963 </description>
1964 </field>
1965 </typedef>
1966 <description>
1967 Get information about the monitors owned by the
1968 specified thread and the depth of the stack frame which locked them.
1969 </description>
1970 <origin>new</origin>
1971 <capabilities>
1972 <required id="can_get_owned_monitor_stack_depth_info"></required>
1973 </capabilities>
1974 <parameters>
1975 <param id="thread">
1976 <jthread null="current"/>
1977 <description>
1978 The thread to query.
1979 </description>
1980 </param>
1981 <param id="monitor_info_count_ptr">
1982 <outptr><jint/></outptr>
1983 <description>
1984 The number of monitors returned.
1985 </description>
1986 </param>
1987 <param id="monitor_info_ptr">
1988 <allocbuf outcount="monitor_info_count_ptr">
1989 <struct>jvmtiMonitorStackDepthInfo</struct>
1990 </allocbuf>
1991 <description>
1992 The array of owned monitor depth information.
1993 </description>
1994 </param>
1995 </parameters>
1996 <errors>
1997 </errors>
1998 </function>
1999
2000 <function id="GetCurrentContendedMonitor" num="11">
2001 <synopsis>Get Current Contended Monitor</synopsis>
2002 <description>
2003 Get the object, if any, whose monitor the specified thread is waiting to
2004 enter or waiting to regain through <code>java.lang.Object.wait</code>.
2005 </description>
2006 <origin>jvmdi</origin>
2007 <capabilities>
2008 <required id="can_get_current_contended_monitor"></required>
2009 </capabilities>
2010 <parameters>
2011 <param id="thread">
2012 <jthread null="current"/>
2013 <description>
2014 The thread to query.
2015 </description>
2016 </param>
2017 <param id="monitor_ptr">
2018 <outptr><jobject/></outptr>
2019 <description>
2020 On return, filled with the current contended monitor, or
2021 NULL if there is none.
2022 </description>
2023 </param>
2024 </parameters>
2025 <errors>
2026 </errors>
2027 </function>
2028
2029 <callback id="jvmtiStartFunction">
2030 <void/>
2031 <synopsis>Agent Start Function</synopsis>
2032 <description>
2033 Agent supplied callback function.
2034 This function is the entry point for an agent thread
2035 started with
2036 <functionlink id="RunAgentThread"></functionlink>.
2037 </description>
2038 <parameters>
2039 <param id="jvmti_env">
2040 <outptr>
2041 <struct>jvmtiEnv</struct>
2042 </outptr>
2043 <description>
2044 The <jvmti/> environment.
2045 </description>
2046 </param>
2047 <param id="jni_env">
2048 <outptr>
2049 <struct>JNIEnv</struct>
2050 </outptr>
2051 <description>
2052 The JNI environment.
2053 </description>
2054 </param>
2055 <param id="arg">
2056 <outptr>
2057 <void/>
2058 </outptr>
2059 <description>
2060 The <code>arg</code> parameter passed to
2061 <functionlink id="RunAgentThread"></functionlink>.
2062 </description>
2063 </param>
2064 </parameters>
2065 </callback>
2066
2067 <function id="RunAgentThread" num="12">
2068 <synopsis>Run Agent Thread</synopsis>
2069 <description>
2070 Starts the execution of an agent thread. with the specified native function.
2071 The parameter <paramlink id="arg"></paramlink> is forwarded on to the
2072 <functionlink id="jvmtiStartFunction">start function</functionlink>
2073 (specified with <paramlink id="proc"></paramlink>) as its single argument.
2074 This function allows the creation of agent threads
2075 for handling communication with another process or for handling events
2076 without the need to load a special subclass of <code>java.lang.Thread</code> or
2077 implementer of <code>java.lang.Runnable</code>.
2078 Instead, the created thread can run entirely in native code.
2079 However, the created thread does require a newly created instance
2080 of <code>java.lang.Thread</code> (referenced by the argument <code>thread</code>) to
2081 which it will be associated.
2082 The thread object can be created with JNI calls.
2083 <p/>
2084 The following common thread priorities are provided for your convenience:
2085 <constants id="jvmtiThreadPriority" label="Thread Priority Constants" kind="const">
2086 <constant id="JVMTI_THREAD_MIN_PRIORITY" num="1">
2087 Minimum possible thread priority
2088 </constant>
2089 <constant id="JVMTI_THREAD_NORM_PRIORITY" num="5">
2090 Normal thread priority
2091 </constant>
2092 <constant id="JVMTI_THREAD_MAX_PRIORITY" num="10">
2093 Maximum possible thread priority
2094 </constant>
2095 </constants>
2096 <p/>
2097 The new thread is started as a daemon thread with the specified
2098 <paramlink id="priority"></paramlink>.
2099 If enabled, a <eventlink id="ThreadStart"/> event will be sent.
2100 <p/>
2101 Since the thread has been started, the thread will be live when this function
2102 returns, unless the thread has died immediately.
2103 <p/>
2104 The thread group of the thread is ignored -- specifically, the thread is not
2105 added to the thread group and the thread is not seen on queries of the thread
2106 group at either the Java programming language or <jvmti/> levels.
2107 <p/>
2108 The thread is not visible to Java programming language queries but is
2109 included in <jvmti/> queries (for example,
2110 <functionlink id="GetAllThreads"/> and
2111 <functionlink id="GetAllStackTraces"/>).
2112 <p/>
2113 Upon execution of <code>proc</code>, the new thread will be attached to the
2114 VM -- see the JNI documentation on
2115 <externallink id="docs/technotes/guides/jni/spec/invocation.html#attaching_to_the_vm"
2116 >Attaching to the VM</externallink>.
2117 </description>
2118 <origin>jvmdiClone</origin>
2119 <capabilities>
2120 </capabilities>
2121 <parameters>
2122 <param id="thread">
2123 <jthread impl="noconvert" started="no"/>
2124 <description>
2125 The thread to run.
2126 </description>
2127 </param>
2128 <param id="proc">
2129 <ptrtype>
2130 <struct>jvmtiStartFunction</struct>
2131 </ptrtype>
2132 <description>
2133 The start function.
2134 </description>
2135 </param>
2136 <param id="arg">
2137 <inbuf>
2138 <void/>
2139 <nullok><code>NULL</code> is passed to the start function</nullok>
2140 </inbuf>
2141 <description>
2142 The argument to the start function.
2143 </description>
2144 </param>
2145 <param id="priority">
2146 <jint/>
2147 <description>
2148 The priority of the started thread. Any thread
2149 priority allowed by <code>java.lang.Thread.setPriority</code> can be used including
2150 those in <datalink id="jvmtiThreadPriority"></datalink>.
2151 </description>
2152 </param>
2153 </parameters>
2154 <errors>
2155 <error id="JVMTI_ERROR_INVALID_PRIORITY">
2156 <paramlink id="priority"/> is less than
2157 <datalink id="JVMTI_THREAD_MIN_PRIORITY"/>
2158 or greater than
2159 <datalink id="JVMTI_THREAD_MAX_PRIORITY"/>
2160 </error>
2161 </errors>
2162 </function>
2163
2164 <function id="SetThreadLocalStorage" jkernel="yes" impl="notrace" phase="start" num="103">
2165 <synopsis>Set Thread Local Storage</synopsis>
2166 <description>
2167 The VM stores a pointer value associated with each environment-thread
2168 pair. This pointer value is called <i>thread-local storage</i>.
2169 This value is <code>NULL</code> unless set with this function.
2170 Agents can allocate memory in which they store thread specific
2171 information. By setting thread-local storage it can then be
2172 accessed with
2173 <functionlink id="GetThreadLocalStorage"></functionlink>.
2174 <p/>
2175 This function is called by the agent to set the value of the <jvmti/>
2176 thread-local storage. <jvmti/> supplies to the agent a pointer-size
2177 thread-local storage that can be used to record per-thread
2178 information.
2179 </description>
2180 <origin>jvmpi</origin>
2181 <capabilities>
2182 </capabilities>
2183 <parameters>
2184 <param id="thread">
2185 <jthread null="current"/>
2186 <description>
2187 Store to this thread.
2188 </description>
2189 </param>
2190 <param id="data">
2191 <inbuf>
2192 <void/>
2193 <nullok>value is set to <code>NULL</code></nullok>
2194 </inbuf>
2195 <description>
2196 The value to be entered into the thread-local storage.
2197 </description>
2198 </param>
2199 </parameters>
2200 <errors>
2201 </errors>
2202 </function>
2203
2204 <function id="GetThreadLocalStorage" jkernel="yes" impl="innative notrace" phase="start" num="102">
2205 <synopsis>Get Thread Local Storage</synopsis>
2206 <description>
2207 Called by the agent to get the value of the <jvmti/> thread-local
2208 storage.
2209 </description>
2210 <origin>jvmpi</origin>
2211 <capabilities>
2212 </capabilities>
2213 <parameters>
2214 <param id="thread">
2215 <jthread null="current" impl="noconvert"/>
2216 <description>
2217 Retrieve from this thread.
2218 </description>
2219 </param>
2220 <param id="data_ptr">
2221 <agentbuf><void/></agentbuf>
2222 <description>
2223 Pointer through which the value of the thread local
2224 storage is returned.
2225 If thread-local storage has not been set with
2226 <functionlink id="SetThreadLocalStorage"></functionlink> the returned
2227 pointer is <code>NULL</code>.
2228 </description>
2229 </param>
2230 </parameters>
2231 <errors>
2232 </errors>
2233 </function>
2234
2235 </category>
2236
2237 <category id="thread_groups" label="Thread Group">
2238 <intro>
2239 </intro>
2240
2241 <function id="GetTopThreadGroups" num="13">
2242 <synopsis>Get Top Thread Groups</synopsis>
2243 <description>
2244 Return all top-level (parentless) thread groups in the VM.
2245 </description>
2246 <origin>jvmdi</origin>
2247 <capabilities>
2248 </capabilities>
2249 <parameters>
2250 <param id="group_count_ptr">
2251 <outptr><jint/></outptr>
2252 <description>
2253 On return, points to the number of top-level thread groups.
2254 </description>
2255 </param>
2256 <param id="groups_ptr">
2257 <allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf>
2258 <description>
2259 On return, refers to a pointer to the top-level thread group array.
2260 </description>
2261 </param>
2262 </parameters>
2263 <errors>
2264 </errors>
2265 </function>
2266
2267 <function id="GetThreadGroupInfo" num="14">
2268 <synopsis>Get Thread Group Info</synopsis>
2269 <typedef id="jvmtiThreadGroupInfo" label="Thread group information structure">
2270 <field id="parent">
2271 <jthreadGroup/>
2272 <description>
2273 The parent thread group.
2274 </description>
2275 </field>
2276 <field id="name">
2277 <allocfieldbuf><char/></allocfieldbuf>
2278 <description>
2279 The thread group's name, encoded as a
2280 <internallink id="mUTF">modified UTF-8</internallink> string.
2281 </description>
2282 </field>
2283 <field id="max_priority">
2284 <jint/>
2285 <description>
2286 The maximum priority for this thread group.
2287 </description>
2288 </field>
2289 <field id="is_daemon">
2290 <jboolean/>
2291 <description>
2292 Is this a daemon thread group?
2293 </description>
2294 </field>
2295 </typedef>
2296 <description>
2297 Get information about the thread group. The fields of the
2298 <functionlink id="jvmtiThreadGroupInfo"></functionlink> structure
2299 are filled in with details of the specified thread group.
2300 </description>
2301 <origin>jvmdi</origin>
2302 <capabilities>
2303 </capabilities>
2304 <parameters>
2305 <param id="group">
2306 <jthreadGroup/>
2307 <description>
2308 The thread group to query.
2309 </description>
2310 </param>
2311 <param id="info_ptr">
2312 <outptr><struct>jvmtiThreadGroupInfo</struct></outptr>
2313 <description>
2314 On return, filled with information describing the specified
2315 thread group.
2316 </description>
2317 </param>
2318 </parameters>
2319 <errors>
2320 </errors>
2321 </function>
2322
2323 <function id="GetThreadGroupChildren" num="15">
2324 <synopsis>Get Thread Group Children</synopsis>
2325 <description>
2326 Get the live threads and active subgroups in this thread group.
2327 </description>
2328 <origin>jvmdi</origin>
2329 <capabilities>
2330 </capabilities>
2331 <parameters>
2332 <param id="group">
2333 <jthreadGroup/>
2334 <description>
2335 The group to query.
2336 </description>
2337 </param>
2338 <param id="thread_count_ptr">
2339 <outptr><jint/></outptr>
2340 <description>
2341 On return, points to the number of live threads in this thread group.
2342 </description>
2343 </param>
2344 <param id="threads_ptr">
2345 <allocbuf outcount="thread_count_ptr"><jthread/></allocbuf>
2346 <description>
2347 On return, points to an array of the live threads in this thread group.
2348 </description>
2349 </param>
2350 <param id="group_count_ptr">
2351 <outptr><jint/></outptr>
2352 <description>
2353 On return, points to the number of active child thread groups
2354 </description>
2355 </param>
2356 <param id="groups_ptr">
2357 <allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf>
2358 <description>
2359 On return, points to an array of the active child thread groups.
2360 </description>
2361 </param>
2362 </parameters>
2363 <errors>
2364 </errors>
2365 </function>
2366 </category>
2367
2368 <category id="stack" label="Stack Frame">
2369 <intro>
2370 These functions provide information about the stack of a thread.
2371 Stack frames are referenced by depth.
2372 The frame at depth zero is the current frame.
2373 <p/>
2374 Stack frames are as described in
2375 <vmspec chapter="3.6"/>,
2376 That is, they correspond to method
2377 invocations (including native methods) but do not correspond to platform native or
2378 VM internal frames.
2379 <p/>
2380 A <jvmti/> implementation may use method invocations to launch a thread and
2381 the corresponding frames may be included in the stack as presented by these functions --
2382 that is, there may be frames shown
2383 deeper than <code>main()</code> and <code>run()</code>.
2384 However this presentation must be consistent across all <jvmti/> functionality which
2385 uses stack frames or stack depth.
2386 </intro>
2387
2388 <typedef id="jvmtiFrameInfo" label="Stack frame information structure">
2389 <description>
2390 Information about a stack frame is returned in this structure.
2391 </description>
2392 <field id="method">
2393 <jmethodID/>
2394 <description>
2395 The method executing in this frame.
2396 </description>
2397 </field>
2398 <field id="location">
2399 <jlocation/>
2400 <description>
2401 The index of the instruction executing in this frame.
2402 <code>-1</code> if the frame is executing a native method.
2403 </description>
2404 </field>
2405 </typedef>
2406
2407 <typedef id="jvmtiStackInfo" label="Stack information structure">
2408 <description>
2409 Information about a set of stack frames is returned in this structure.
2410 </description>
2411 <field id="thread">
2412 <jthread/>
2413 <description>
2414 On return, the thread traced.
2415 </description>
2416 </field>
2417 <field id="state">
2418 <jint/>
2419 <description>
2420 On return, the thread state. See <functionlink id="GetThreadState"></functionlink>.
2421 </description>
2422 </field>
2423 <field id="frame_buffer">
2424 <outbuf incount="max_frame_count">
2425 <struct>jvmtiFrameInfo</struct>
2426 </outbuf>
2427 <description>
2428 On return, this agent allocated buffer is filled
2429 with stack frame information.
2430 </description>
2431 </field>
2432 <field id="frame_count">
2433 <jint/>
2434 <description>
2435 On return, the number of records filled into
2436 <code>frame_buffer</code>.
2437 This will be
2438 min(<code>max_frame_count</code>, <i>stackDepth</i>).
2439 </description>
2440 </field>
2441 </typedef>
2442
2443 <function id="GetStackTrace" num="104">
2444 <synopsis>Get Stack Trace</synopsis>
2445 <description>
2446 Get information about the stack of a thread.
2447 If <paramlink id="max_frame_count"></paramlink> is less than the depth of the stack,
2448 the <paramlink id="max_frame_count"></paramlink> topmost frames are returned,
2449 otherwise the entire stack is returned.
2450 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2451 <p/>
2452 The following example causes up to five of the topmost frames
2453 to be returned and (if there are any frames) the currently
2454 executing method name to be printed.
2455 <example>
2456 jvmtiFrameInfo frames[5];
2457 jint count;
2458 jvmtiError err;
2459
2460 err = (*jvmti)->GetStackTrace(jvmti, aThread, 0, 5,
2461 frames, &count);
2462 if (err == JVMTI_ERROR_NONE && count >= 1) {
2463 char *methodName;
2464 err = (*jvmti)->GetMethodName(jvmti, frames[0].method,
2465 &methodName, NULL, NULL);
2466 if (err == JVMTI_ERROR_NONE) {
2467 printf("Executing method: %s", methodName);
2468 }
2469 }
2470 </example>
2471 <todo>
2472 check example code.
2473 </todo>
2474 <p/>
2475 The <paramlink id="thread"></paramlink> need not be suspended
2476 to call this function.
2477 <p/>
2478 The <functionlink id="GetLineNumberTable"></functionlink>
2479 function can be used to map locations to line numbers. Note that
2480 this mapping can be done lazily.
2481 </description>
2482 <origin>jvmpi</origin>
2483 <capabilities>
2484 </capabilities>
2485 <parameters>
2486 <param id="thread">
2487 <jthread null="current"/>
2488 <description>
2489 Fetch the stack trace of this thread.
2490 </description>
2491 </param>
2492 <param id="start_depth">
2493 <jint/>
2494 <description>
2495 Begin retrieving frames at this depth.
2496 If non-negative, count from the current frame,
2497 the first frame retrieved is at depth <code>start_depth</code>.
2498 For example, if zero, start from the current frame; if one, start from the
2499 caller of the current frame; if two, start from the caller of the
2500 caller of the current frame; and so on.
2501 If negative, count from below the oldest frame,
2502 the first frame retrieved is at depth <i>stackDepth</i><code> + start_depth</code>,
2503 where <i>stackDepth</i> is the count of frames on the stack.
2504 For example, if negative one, only the oldest frame is retrieved;
2505 if negative two, start from the frame called by the oldest frame.
2506 </description>
2507 </param>
2508 <param id="max_frame_count">
2509 <jint min="0"/>
2510 <description>
2511 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve.
2512 </description>
2513 </param>
2514 <param id="frame_buffer">
2515 <outbuf incount="max_frame_count" outcount="count_ptr">
2516 <struct>jvmtiFrameInfo</struct>
2517 </outbuf>
2518 <description>
2519 On return, this agent allocated buffer is filled
2520 with stack frame information.
2521 </description>
2522 </param>
2523 <param id="count_ptr">
2524 <outptr><jint/></outptr>
2525 <description>
2526 On return, points to the number of records filled in.
2527 For non-negative <code>start_depth</code>, this will be
2528 min(<code>max_frame_count</code>, <i>stackDepth</i><code> - start_depth</code>).
2529 For negative <code>start_depth</code>, this will be
2530 min(<code>max_frame_count</code>, <code>-start_depth</code>).
2531 </description>
2532 </param>
2533 </parameters>
2534 <errors>
2535 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
2536 <paramlink id="start_depth"/> is positive and greater than or equal to <i>stackDepth</i>.
2537 Or <paramlink id="start_depth"/> is negative and less than <i>-stackDepth</i>.
2538 </error>
2539 </errors>
2540 </function>
2541
2542
2543 <function id="GetAllStackTraces" num="100">
2544 <synopsis>Get All Stack Traces</synopsis>
2545 <description>
2546 Get information about the stacks of all live threads
2547 (including <internallink id="RunAgentThread">agent threads</internallink>).
2548 If <paramlink id="max_frame_count"/> is less than the depth of a stack,
2549 the <paramlink id="max_frame_count"/> topmost frames are returned for that thread,
2550 otherwise the entire stack is returned.
2551 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2552 <p/>
2553 All stacks are collected simultaneously, that is, no changes will occur to the
2554 thread state or stacks between the sampling of one thread and the next.
2555 The threads need not be suspended.
2556
2557 <example>
2558 jvmtiStackInfo *stack_info;
2559 jint thread_count;
2560 int ti;
2561 jvmtiError err;
2562
2563 err = (*jvmti)->GetAllStackTraces(jvmti, MAX_FRAMES, &stack_info, &thread_count);
2564 if (err != JVMTI_ERROR_NONE) {
2565 ...
2566 }
2567 for (ti = 0; ti < thread_count; ++ti) {
2568 jvmtiStackInfo *infop = &stack_info[ti];
2569 jthread thread = infop->thread;
2570 jint state = infop->state;
2571 jvmtiFrameInfo *frames = infop->frame_buffer;
2572 int fi;
2573
2574 myThreadAndStatePrinter(thread, state);
2575 for (fi = 0; fi < infop->frame_count; fi++) {
2576 myFramePrinter(frames[fi].method, frames[fi].location);
2577 }
2578 }
2579 /* this one Deallocate call frees all data allocated by GetAllStackTraces */
2580 err = (*jvmti)->Deallocate(jvmti, stack_info);
2581 </example>
2582 <todo>
2583 check example code.
2584 </todo>
2585
2586 </description>
2587 <origin>new</origin>
2588 <capabilities>
2589 </capabilities>
2590 <parameters>
2591 <param id="max_frame_count">
2592 <jint min="0"/>
2593 <description>
2594 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread.
2595 </description>
2596 </param>
2597 <param id="stack_info_ptr">
2598 <allocbuf>
2599 <struct>jvmtiStackInfo</struct>
2600 </allocbuf>
2601 <description>
2602 On return, this buffer is filled
2603 with stack information for each thread.
2604 The number of <datalink id="jvmtiStackInfo"/> records is determined
2605 by <paramlink id="thread_count_ptr"/>.
2606 <p/>
2607 Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/>
2608 buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>.
2609 These buffers must not be separately deallocated.
2610 </description>
2611 </param>
2612 <param id="thread_count_ptr">
2613 <outptr><jint/></outptr>
2614 <description>
2615 The number of threads traced.
2616 </description>
2617 </param>
2618 </parameters>
2619 <errors>
2620 </errors>
2621 </function>
2622
2623 <function id="GetThreadListStackTraces" num="101">
2624 <synopsis>Get Thread List Stack Traces</synopsis>
2625 <description>
2626 Get information about the stacks of the supplied threads.
2627 If <paramlink id="max_frame_count"/> is less than the depth of a stack,
2628 the <paramlink id="max_frame_count"/> topmost frames are returned for that thread,
2629 otherwise the entire stack is returned.
2630 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2631 <p/>
2632 All stacks are collected simultaneously, that is, no changes will occur to the
2633 thread state or stacks between the sampling one thread and the next.
2634 The threads need not be suspended.
2635 <p/>
2636 If a thread has not yet started or terminates before the stack information is collected,
2637 a zero length stack (<datalink id="jvmtiStackInfo.frame_count"/> will be zero)
2638 will be returned and the thread <datalink id="jvmtiStackInfo.state"/> can be checked.
2639 <p/>
2640 See the example for the similar function
2641 <functionlink id="GetAllStackTraces"/>.
2642 </description>
2643 <origin>new</origin>
2644 <capabilities>
2645 </capabilities>
2646 <parameters>
2647 <param id="thread_count">
2648 <jint min="0"/>
2649 <description>
2650 The number of threads to trace.
2651 </description>
2652 </param>
2653 <param id="thread_list">
2654 <inbuf incount="thread_count"><jthread/></inbuf>
2655 <description>
2656 The list of threads to trace.
2657 </description>
2658 </param>
2659 <param id="max_frame_count">
2660 <jint min="0"/>
2661 <description>
2662 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread.
2663 </description>
2664 </param>
2665 <param id="stack_info_ptr">
2666 <allocbuf outcount="thread_count">
2667 <struct>jvmtiStackInfo</struct>
2668 </allocbuf>
2669 <description>
2670 On return, this buffer is filled
2671 with stack information for each thread.
2672 The number of <datalink id="jvmtiStackInfo"/> records is determined
2673 by <paramlink id="thread_count"/>.
2674 <p/>
2675 Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/>
2676 buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>.
2677 These buffers must not be separately deallocated.
2678 </description>
2679 </param>
2680 </parameters>
2681 <errors>
2682 <error id="JVMTI_ERROR_INVALID_THREAD">
2683 An element in <paramlink id="thread_list"/> is not a thread object.
2684 </error>
2685 </errors>
2686 </function>
2687
2688 <elide>
2689 <function id="AsyncGetStackTrace" num="1000">
2690 <synopsis>Get Stack Trace--Asynchronous</synopsis>
2691 <description>
2692 Get information about the entire stack of a thread (or a sub-section of it).
2693 This is the asynchronous version of <functionlink id="GetStackTrace"></functionlink>
2694 and is reentrant and safe to call
2695 from asynchronous signal handlers.
2696 The stack trace is returned only for the calling thread.
2697 <p/>
2698 The <functionlink id="GetLineNumberTable"></functionlink>
2699 function can be used to map locations to line numbers. Note that
2700 this mapping can be done lazily.
2701 </description>
2702 <origin>jvmpi</origin>
2703 <capabilities>
2704 <required id="can_get_async_stack_trace"></required>
2705 <capability id="can_show_JVM_spec_async_frames">
2706 If <code>false</code>,
2707 <paramlink id="use_java_stack"></paramlink>
2708 must be <code>false</code>.
2709 </capability>
2710 </capabilities>
2711 <parameters>
2712 <param id="use_java_stack">
2713 <jboolean/>
2714 <description>
2715 Return the stack showing <vmspec/>
2716 model of the stack;
2717 otherwise, show the internal representation of the stack with
2718 inlined and optimized methods missing. If the virtual machine
2719 is using the <i>Java Virtual Machine Specification</i> stack model
2720 internally, this flag is ignored.
2721 </description>
2722 </param>
2723 <param id="max_count">
2724 <jint min="0"/>
2725 <description>
2726 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve.
2727 Retrieve this many unless the stack depth is less than <code>max_count</code>.
2728 </description>
2729 </param>
2730 <param id="frame_buffer">
2731 <outbuf incount="max_count" outcount="count_ptr">
2732 <struct>jvmtiFrameInfo</struct>
2733 <nullok>this information is not returned</nullok>
2734 </outbuf>
2735 <description>
2736 The agent passes in a buffer
2737 large enough to hold <code>max_count</code> records of
2738 <datalink id="jvmtiFrameInfo"></datalink>. This buffer must be
2739 pre-allocated by the agent.
2740 </description>
2741 </param>
2742 <param id="count_ptr">
2743 <outptr><jint/></outptr>
2744 <description>
2745 On return, points to the number of records filled in..
2746 </description>
2747 </param>
2748 </parameters>
2749 <errors>
2750 <error id="JVMTI_ERROR_UNATTACHED_THREAD">
2751 The thread being used to call this function is not attached
2752 to the virtual machine. Calls must be made from attached threads.
2753 </error>
2754 </errors>
2755 </function>
2756 </elide>
2757
2758 <function id="GetFrameCount" num="16">
2759 <synopsis>Get Frame Count</synopsis>
2760 <description>
2761 Get the number of frames currently in the specified thread's call stack.
2762 <p/>
2763 If this function is called for a thread actively executing bytecodes (for example,
2764 not the current thread and not suspended), the information returned is transient.
2765 </description>
2766 <origin>jvmdi</origin>
2767 <capabilities>
2768 </capabilities>
2769 <parameters>
2770 <param id="thread">
2771 <jthread null="current"/>
2772 <description>
2773 The thread to query.
2774 </description>
2775 </param>
2776 <param id="count_ptr">
2777 <outptr><jint/></outptr>
2778 <description>
2779 On return, points to the number of frames in the call stack.
2780 </description>
2781 </param>
2782 </parameters>
2783 <errors>
2784 </errors>
2785 </function>
2786
2787 <function id="PopFrame" num="80">
2788 <synopsis>Pop Frame</synopsis>
2789 <description>
2790 Pop the current frame of <code>thread</code>'s stack.
2791 Popping a frame takes you to the previous frame.
2792 When the thread is resumed, the execution
2793 state of the thread is reset to the state
2794 immediately before the called method was invoked.
2795 That is (using <vmspec/> terminology):
2796 <ul>
2797 <li>the current frame is discarded as the previous frame becomes the current one</li>
2798 <li>the operand stack is restored--the argument values are added back
2799 and if the invoke was not <code>invokestatic</code>,
2800 <code>objectref</code> is added back as well</li>
2801 <li>the Java virtual machine PC is restored to the opcode
2802 of the invoke instruction</li>
2803 </ul>
2804 Note however, that any changes to the arguments, which
2805 occurred in the called method, remain;
2806 when execution continues, the first instruction to
2807 execute will be the invoke.
2808 <p/>
2809 Between calling <code>PopFrame</code> and resuming the
2810 thread the state of the stack is undefined.
2811 To pop frames beyond the first,
2812 these three steps must be repeated:
2813 <ul>
2814 <li>suspend the thread via an event (step, breakpoint, ...)</li>
2815 <li>call <code>PopFrame</code></li>
2816 <li>resume the thread</li>
2817 </ul>
2818 <p/>
2819 A lock acquired by calling the called method
2820 (if it is a <code>synchronized</code> method)
2821 and locks acquired by entering <code>synchronized</code>
2822 blocks within the called method are released.
2823 Note: this does not apply to native locks or
2824 <code>java.util.concurrent.locks</code> locks.
2825 <p/>
2826 Finally blocks are not executed.
2827 <p/>
2828 Changes to global state are not addressed and thus remain changed.
2829 <p/>
2830 The specified thread must be suspended (which implies it cannot be the current thread).
2831 <p/>
2832 Both the called method and calling method must be non-native Java programming
2833 language methods.
2834 <p/>
2835 No <jvmti/> events are generated by this function.
2836 </description>
2837 <origin>jvmdi</origin>
2838 <capabilities>
2839 <required id="can_pop_frame"></required>
2840 </capabilities>
2841 <parameters>
2842 <param id="thread">
2843 <jthread/>
2844 <description>
2845 The thread whose current frame is to be popped.
2846 </description>
2847 </param>
2848 </parameters>
2849 <errors>
2850 <error id="JVMTI_ERROR_OPAQUE_FRAME">
2851 Called or calling method is a native method.
2852 The implementation is unable to pop this frame.
2853 </error>
2854 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2855 Thread was not suspended.
2856 </error>
2857 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
2858 There are less than two stack frames on the call stack.
2859 </error>
2860 </errors>
2861 </function>
2862
2863 <function id="GetFrameLocation" num="19">
2864 <synopsis>Get Frame Location</synopsis>
2865 <description>
2866 <p/>
2867 For a Java programming language frame, return the location of the instruction
2868 currently executing.
2869 </description>
2870 <origin>jvmdiClone</origin>
2871 <capabilities>
2872 </capabilities>
2873 <parameters>
2874 <param id="thread">
2875 <jthread null="current" frame="frame"/>
2876 <description>
2877 The thread of the frame to query.
2878 </description>
2879 </param>
2880 <param id="depth">
2881 <jframeID thread="thread"/>
2882 <description>
2883 The depth of the frame to query.
2884 </description>
2885 </param>
2886 <param id="method_ptr">
2887 <outptr><jmethodID/></outptr>
2888 <description>
2889 On return, points to the method for the current location.
2890 </description>
2891 </param>
2892 <param id="location_ptr">
2893 <outptr><jlocation/></outptr>
2894 <description>
2895 On return, points to the index of the currently
2896 executing instruction.
2897 Is set to <code>-1</code> if the frame is executing
2898 a native method.
2899 </description>
2900 </param>
2901 </parameters>
2902 <errors>
2903 </errors>
2904 </function>
2905
2906 <function id="NotifyFramePop" num="20">
2907 <synopsis>Notify Frame Pop</synopsis>
2908 <description>
2909 When the frame that is currently at <paramlink id="depth"></paramlink>
2910 is popped from the stack, generate a
2911 <eventlink id="FramePop"></eventlink> event. See the
2912 <eventlink id="FramePop"></eventlink> event for details.
2913 Only frames corresponding to non-native Java programming language
2914 methods can receive notification.
2915 <p/>
2916 The specified thread must either be the current thread
2917 or the thread must be suspended.
2918 </description>
2919 <origin>jvmdi</origin>
2920 <capabilities>
2921 <required id="can_generate_frame_pop_events"></required>
2922 </capabilities>
2923 <parameters>
2924 <param id="thread">
2925 <jthread null="current" frame="depth"/>
2926 <description>
2927 The thread of the frame for which the frame pop event will be generated.
2928 </description>
2929 </param>
2930 <param id="depth">
2931 <jframeID thread="thread"/>
2932 <description>
2933 The depth of the frame for which the frame pop event will be generated.
2934 </description>
2935 </param>
2936 </parameters>
2937 <errors>
2938 <error id="JVMTI_ERROR_OPAQUE_FRAME">
2939 The frame at <code>depth</code> is executing a
2940 native method.
2941 </error>
2942 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2943 Thread was not suspended and was not the current thread.
2944 </error>
2945 </errors>
2946 </function>
2947
2948 </category>
2949
2950 <category id="ForceEarlyReturn" label="Force Early Return">
2951 <intro>
2952 These functions allow an agent to force a method
2953 to return at any point during its execution.
2954 The method which will return early is referred to as the <i>called method</i>.
2955 The called method is the current method
2956 (as defined by
2957 <vmspec chapter="3.6"/>)
2958 for the specified thread at
2959 the time the function is called.
2960 <p/>
2961 The specified thread must be suspended or must be the current thread.
2962 The return occurs when execution of Java programming
2963 language code is resumed on this thread.
2964 Between calling one of these functions and resumption
2965 of thread execution, the state of the stack is undefined.
2966 <p/>
2967 No further instructions are executed in the called method.
2968 Specifically, finally blocks are not executed.
2969 Note: this can cause inconsistent states in the application.
2970 <p/>
2971 A lock acquired by calling the called method
2972 (if it is a <code>synchronized</code> method)
2973 and locks acquired by entering <code>synchronized</code>
2974 blocks within the called method are released.
2975 Note: this does not apply to native locks or
2976 <code>java.util.concurrent.locks</code> locks.
2977 <p/>
2978 Events, such as <eventlink id="MethodExit"></eventlink>,
2979 are generated as they would be in a normal return.
2980 <p/>
2981 The called method must be a non-native Java programming
2982 language method.
2983 Forcing return on a thread with only one frame on the
2984 stack causes the thread to exit when resumed.
2985 </intro>
2986
2987 <function id="ForceEarlyReturnObject" num="81" since="1.1">
2988 <synopsis>Force Early Return - Object</synopsis>
2989 <description>
2990 This function can be used to return from a method whose
2991 result type is <code>Object</code>
2992 or a subclass of <code>Object</code>.
2993 </description>
2994 <origin>new</origin>
2995 <capabilities>
2996 <required id="can_force_early_return"></required>
2997 </capabilities>
2998 <parameters>
2999 <param id="thread">
3000 <jthread null="current"/>
3001 <description>
3002 The thread whose current frame is to return early.
3003 </description>
3004 </param>
3005 <param id="value">
3006 <jobject/>
3007 <description>
3008 The return value for the called frame.
3009 An object or <code>NULL</code>.
3010 </description>
3011 </param>
3012 </parameters>
3013 <errors>
3014 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3015 Attempted to return early from a frame
3016 corresponding to a native method.
3017 Or the implementation is unable to provide
3018 this functionality on this frame.
3019 </error>
3020 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3021 The result type of the called method is not
3022 <code>Object</code> or a subclass of <code>Object</code>.
3023 </error>
3024 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3025 The supplied <paramlink id="value"/> is not compatible with the
3026 result type of the called method.
3027 </error>
3028 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3029 Thread was not the current thread and was not suspended.
3030 </error>
3031 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3032 There are no more frames on the call stack.
3033 </error>
3034 </errors>
3035 </function>
3036
3037 <function id="ForceEarlyReturnInt" num="82" since="1.1">
3038 <synopsis>Force Early Return - Int</synopsis>
3039 <description>
3040 This function can be used to return from a method whose
3041 result type is <code>int</code>, <code>short</code>,
3042 <code>char</code>, <code>byte</code>, or
3043 <code>boolean</code>.
3044 </description>
3045 <origin>new</origin>
3046 <capabilities>
3047 <required id="can_force_early_return"></required>
3048 </capabilities>
3049 <parameters>
3050 <param id="thread">
3051 <jthread null="current"/>
3052 <description>
3053 The thread whose current frame is to return early.
3054 </description>
3055 </param>
3056 <param id="value">
3057 <jint/>
3058 <description>
3059 The return value for the called frame.
3060 </description>
3061 </param>
3062 </parameters>
3063 <errors>
3064 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3065 Attempted to return early from a frame
3066 corresponding to a native method.
3067 Or the implementation is unable to provide
3068 this functionality on this frame.
3069 </error>
3070 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3071 The result type of the called method is not
3072 <code>int</code>, <code>short</code>,
3073 <code>char</code>, <code>byte</code>, or
3074 <code>boolean</code>.
3075 </error>
3076 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3077 Thread was not the current thread and was not suspended.
3078 </error>
3079 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3080 There are no frames on the call stack.
3081 </error>
3082 </errors>
3083 </function>
3084
3085 <function id="ForceEarlyReturnLong" num="83" since="1.1">
3086 <synopsis>Force Early Return - Long</synopsis>
3087 <description>
3088 This function can be used to return from a method whose
3089 result type is <code>long</code>.
3090 </description>
3091 <origin>new</origin>
3092 <capabilities>
3093 <required id="can_force_early_return"></required>
3094 </capabilities>
3095 <parameters>
3096 <param id="thread">
3097 <jthread null="current"/>
3098 <description>
3099 The thread whose current frame is to return early.
3100 </description>
3101 </param>
3102 <param id="value">
3103 <jlong/>
3104 <description>
3105 The return value for the called frame.
3106 </description>
3107 </param>
3108 </parameters>
3109 <errors>
3110 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3111 Attempted to return early from a frame
3112 corresponding to a native method.
3113 Or the implementation is unable to provide
3114 this functionality on this frame.
3115 </error>
3116 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3117 The result type of the called method is not <code>long</code>.
3118 </error>
3119 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3120 Thread was not the current thread and was not suspended.
3121 </error>
3122 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3123 There are no frames on the call stack.
3124 </error>
3125 </errors>
3126 </function>
3127
3128 <function id="ForceEarlyReturnFloat" num="84" since="1.1">
3129 <synopsis>Force Early Return - Float</synopsis>
3130 <description>
3131 This function can be used to return from a method whose
3132 result type is <code>float</code>.
3133 </description>
3134 <origin>new</origin>
3135 <capabilities>
3136 <required id="can_force_early_return"></required>
3137 </capabilities>
3138 <parameters>
3139 <param id="thread">
3140 <jthread null="current"/>
3141 <description>
3142 The thread whose current frame is to return early.
3143 </description>
3144 </param>
3145 <param id="value">
3146 <jfloat/>
3147 <description>
3148 The return value for the called frame.
3149 </description>
3150 </param>
3151 </parameters>
3152 <errors>
3153 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3154 Attempted to return early from a frame
3155 corresponding to a native method.
3156 Or the implementation is unable to provide
3157 this functionality on this frame.
3158 </error>
3159 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3160 The result type of the called method is not <code>float</code>.
3161 </error>
3162 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3163 Thread was not the current thread and was not suspended.
3164 </error>
3165 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3166 There are no frames on the call stack.
3167 </error>
3168 </errors>
3169 </function>
3170
3171 <function id="ForceEarlyReturnDouble" num="85" since="1.1">
3172 <synopsis>Force Early Return - Double</synopsis>
3173 <description>
3174 This function can be used to return from a method whose
3175 result type is <code>double</code>.
3176 </description>
3177 <origin>new</origin>
3178 <capabilities>
3179 <required id="can_force_early_return"></required>
3180 </capabilities>
3181 <parameters>
3182 <param id="thread">
3183 <jthread null="current"/>
3184 <description>
3185 The thread whose current frame is to return early.
3186 </description>
3187 </param>
3188 <param id="value">
3189 <jdouble/>
3190 <description>
3191 The return value for the called frame.
3192 </description>
3193 </param>
3194 </parameters>
3195 <errors>
3196 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3197 Attempted to return early from a frame corresponding to a native method.
3198 Or the implementation is unable to provide this functionality on this frame.
3199 </error>
3200 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3201 The result type of the called method is not <code>double</code>.
3202 </error>
3203 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3204 Thread was not the current thread and was not suspended.
3205 </error>
3206 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3207 There are no frames on the call stack.
3208 </error>
3209 </errors>
3210 </function>
3211
3212 <function id="ForceEarlyReturnVoid" num="86" since="1.1">
3213 <synopsis>Force Early Return - Void</synopsis>
3214 <description>
3215 This function can be used to return from a method with no result type.
3216 That is, the called method must be declared <code>void</code>.
3217 </description>
3218 <origin>new</origin>
3219 <capabilities>
3220 <required id="can_force_early_return"></required>
3221 </capabilities>
3222 <parameters>
3223 <param id="thread">
3224 <jthread null="current"/>
3225 <description>
3226 The thread whose current frame is to return early.
3227 </description>
3228 </param>
3229 </parameters>
3230 <errors>
3231 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3232 Attempted to return early from a frame
3233 corresponding to a native method.
3234 Or the implementation is unable to provide
3235 this functionality on this frame.
3236 </error>
3237 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3238 The called method has a result type.
3239 </error>
3240 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3241 Thread was not the current thread and was not suspended.
3242 </error>
3243 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3244 There are no frames on the call stack.
3245 </error>
3246 </errors>
3247 </function>
3248
3249 </category>
3250
3251 <category id="Heap" label="Heap">
3252 <intro>
3253 These functions are used to analyze the heap.
3254 Functionality includes the ability to view the objects in the
3255 heap and to tag these objects.
3256 </intro>
3257
3258 <intro id="objectTags" label="Object Tags">
3259 A <i>tag</i> is a value associated with an object.
3260 Tags are explicitly set by the agent using the
3261 <functionlink id="SetTag"></functionlink> function or by
3262 callback functions such as <functionlink id="jvmtiHeapIterationCallback"/>.
3263 <p/>
3264 Tags are local to the environment; that is, the tags of one
3265 environment are not visible in another.
3266 <p/>
3267 Tags are <code>jlong</code> values which can be used
3268 simply to mark an object or to store a pointer to more detailed
3269 information. Objects which have not been tagged have a
3270 tag of zero.
3271 Setting a tag to zero makes the object untagged.
3272 </intro>
3273
3274 <intro id="heapCallbacks" label="Heap Callback Functions">
3275 Heap functions which iterate through the heap and recursively
3276 follow object references use agent supplied callback functions
3277 to deliver the information.
3278 <p/>
3279 These heap callback functions must adhere to the following restrictions --
3280 These callbacks must not use JNI functions.
3281 These callbacks must not use <jvmti/> functions except
3282 <i>callback safe</i> functions which
3283 specifically allow such use (see the raw monitor, memory management,
3284 and environment local storage functions).
3285 <p/>
3286 An implementation may invoke a callback on an internal thread or
3287 the thread which called the iteration function.
3288 Heap callbacks are single threaded -- no more than one callback will
3289 be invoked at a time.
3290 <p/>
3291 The Heap Filter Flags can be used to prevent reporting
3292 based on the tag status of an object or its class.
3293 If no flags are set (the <code>jint</code> is zero), objects
3294 will not be filtered out.
3295
3296 <constants id="jvmtiHeapFilter" label="Heap Filter Flags" kind="bits">
3297 <constant id="JVMTI_HEAP_FILTER_TAGGED" num="0x4">
3298 Filter out tagged objects. Objects which are tagged are not included.
3299 </constant>
3300 <constant id="JVMTI_HEAP_FILTER_UNTAGGED" num="0x8">
3301 Filter out untagged objects. Objects which are not tagged are not included.
3302 </constant>
3303 <constant id="JVMTI_HEAP_FILTER_CLASS_TAGGED" num="0x10">
3304 Filter out objects with tagged classes. Objects whose class is tagged are not included.
3305 </constant>
3306 <constant id="JVMTI_HEAP_FILTER_CLASS_UNTAGGED" num="0x20">
3307 Filter out objects with untagged classes. Objects whose class is not tagged are not included.
3308 </constant>
3309 </constants>
3310
3311 <p/>
3312 The Heap Visit Control Flags are returned by the heap callbacks
3313 and can be used to abort the iteration. For the
3314 <functionlink id="jvmtiHeapReferenceCallback">Heap
3315 Reference Callback</functionlink>, it can also be used
3316 to prune the graph of traversed references
3317 (<code>JVMTI_VISIT_OBJECTS</code> is not set).
3318
3319 <constants id="jvmtiHeapVisitControl"
3320 label="Heap Visit Control Flags"
3321 kind="bits"
3322 since="1.1">
3323 <constant id="JVMTI_VISIT_OBJECTS" num="0x100">
3324 If we are visiting an object and if this callback
3325 was initiated by <functionlink id="FollowReferences"/>,
3326 traverse the references of this object.
3327 Otherwise ignored.
3328 </constant>
3329 <constant id="JVMTI_VISIT_ABORT" num="0x8000">
3330 Abort the iteration. Ignore all other bits.
3331 </constant>
3332 </constants>
3333
3334 <p/>
3335 The Heap Reference Enumeration is provided by the
3336 <functionlink id="jvmtiHeapReferenceCallback">Heap
3337 Reference Callback</functionlink> and
3338 <functionlink id="jvmtiPrimitiveFieldCallback">Primitive Field
3339 Callback</functionlink> to
3340 describe the kind of reference
3341 being reported.
3342
3343 <constants id="jvmtiHeapReferenceKind"
3344 label="Heap Reference Enumeration"
3345 kind="enum"
3346 since="1.1">
3347 <constant id="JVMTI_HEAP_REFERENCE_CLASS" num="1">
3348 Reference from an object to its class.
3349 </constant>
3350 <constant id="JVMTI_HEAP_REFERENCE_FIELD" num="2">
3351 Reference from an object to the value of one of its instance fields.
3352 </constant>
3353 <constant id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT" num="3">
3354 Reference from an array to one of its elements.
3355 </constant>
3356 <constant id="JVMTI_HEAP_REFERENCE_CLASS_LOADER" num="4">
3357 Reference from a class to its class loader.
3358 </constant>
3359 <constant id="JVMTI_HEAP_REFERENCE_SIGNERS" num="5">
3360 Reference from a class to its signers array.
3361 </constant>
3362 <constant id="JVMTI_HEAP_REFERENCE_PROTECTION_DOMAIN" num="6">
3363 Reference from a class to its protection domain.
3364 </constant>
3365 <constant id="JVMTI_HEAP_REFERENCE_INTERFACE" num="7">
3366 Reference from a class to one of its interfaces.
3367 Note: interfaces are defined via a constant pool reference,
3368 so the referenced interfaces may also be reported with a
3369 <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind.
3370 </constant>
3371 <constant id="JVMTI_HEAP_REFERENCE_STATIC_FIELD" num="8">
3372 Reference from a class to the value of one of its static fields.
3373 </constant>
3374 <constant id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL" num="9">
3375 Reference from a class to a resolved entry in the constant pool.
3376 </constant>
3377 <constant id="JVMTI_HEAP_REFERENCE_SUPERCLASS" num="10">
3378 Reference from a class to its superclass.
3379 A callback is not sent if the superclass is <code>java.lang.Object</code>.
3380 Note: loaded classes define superclasses via a constant pool
3381 reference, so the referenced superclass may also be reported with
3382 a <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind.
3383 </constant>
3384 <constant id="JVMTI_HEAP_REFERENCE_JNI_GLOBAL" num="21">
3385 Heap root reference: JNI global reference.
3386 </constant>
3387 <constant id="JVMTI_HEAP_REFERENCE_SYSTEM_CLASS" num="22">
3388 Heap root reference: System class.
3389 </constant>
3390 <constant id="JVMTI_HEAP_REFERENCE_MONITOR" num="23">
3391 Heap root reference: monitor.
3392 </constant>
3393 <constant id="JVMTI_HEAP_REFERENCE_STACK_LOCAL" num="24">
3394 Heap root reference: local variable on the stack.
3395 </constant>
3396 <constant id="JVMTI_HEAP_REFERENCE_JNI_LOCAL" num="25">
3397 Heap root reference: JNI local reference.
3398 </constant>
3399 <constant id="JVMTI_HEAP_REFERENCE_THREAD" num="26">
3400 Heap root reference: Thread.
3401 </constant>
3402 <constant id="JVMTI_HEAP_REFERENCE_OTHER" num="27">
3403 Heap root reference: other heap root reference.
3404 </constant>
3405 </constants>
3406
3407 <p/>
3408 Definitions for the single character type descriptors of
3409 primitive types.
3410
3411 <constants id="jvmtiPrimitiveType"
3412 label="Primitive Type Enumeration"
3413 kind="enum"
3414 since="1.1">
3415 <constant id="JVMTI_PRIMITIVE_TYPE_BOOLEAN" num="90">
3416 'Z' - Java programming language <code>boolean</code> - JNI <code>jboolean</code>
3417 </constant>
3418 <constant id="JVMTI_PRIMITIVE_TYPE_BYTE" num="66">
3419 'B' - Java programming language <code>byte</code> - JNI <code>jbyte</code>
3420 </constant>
3421 <constant id="JVMTI_PRIMITIVE_TYPE_CHAR" num="67">
3422 'C' - Java programming language <code>char</code> - JNI <code>jchar</code>
3423 </constant>
3424 <constant id="JVMTI_PRIMITIVE_TYPE_SHORT" num="83">
3425 'S' - Java programming language <code>short</code> - JNI <code>jshort</code>
3426 </constant>
3427 <constant id="JVMTI_PRIMITIVE_TYPE_INT" num="73">
3428 'I' - Java programming language <code>int</code> - JNI <code>jint</code>
3429 </constant>
3430 <constant id="JVMTI_PRIMITIVE_TYPE_LONG" num="74">
3431 'J' - Java programming language <code>long</code> - JNI <code>jlong</code>
3432 </constant>
3433 <constant id="JVMTI_PRIMITIVE_TYPE_FLOAT" num="70">
3434 'F' - Java programming language <code>float</code> - JNI <code>jfloat</code>
3435 </constant>
3436 <constant id="JVMTI_PRIMITIVE_TYPE_DOUBLE" num="68">
3437 'D' - Java programming language <code>double</code> - JNI <code>jdouble</code>
3438 </constant>
3439 </constants>
3440 </intro>
3441
3442 <typedef id="jvmtiHeapReferenceInfoField"
3443 label="Reference information structure for Field references"
3444 since="1.1">
3445 <description>
3446 Reference information returned for
3447 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> and
3448 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references.
3449 </description>
3450 <field id="index">
3451 <jint/>
3452 <description>
3453 For <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>, the
3454 referrer object is not a class or an inteface.
3455 In this case, <code>index</code> is the index of the field
3456 in the class of the referrer object.
3457 This class is referred to below as <i>C</i>.
3458 <p/>
3459 For <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>,
3460 the referrer object is a class (referred to below as <i>C</i>)
3461 or an interface (referred to below as <i>I</i>).
3462 In this case, <code>index</code> is the index of the field in
3463 that class or interface.
3464 <p/>
3465 If the referrer object is not an interface, then the field
3466 indices are determined as follows:
3467 <ul>
3468 <li>make a list of all the fields in <i>C</i> and its
3469 superclasses, starting with all the fields in
3470 <code>java.lang.Object</code> and ending with all the
3471 fields in <i>C</i>.</li>
3472 <li>Within this list, put
3473 the fields for a given class in the order returned by
3474 <functionlink id="GetClassFields"/>.</li>
3475 <li>Assign the fields in this list indices
3476 <i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i>
3477 is the count of the fields in all the interfaces
3478 implemented by <i>C</i>.
3479 Note that <i>C</i> implements all interfaces
3480 directly implemented by its superclasses; as well
3481 as all superinterfaces of these interfaces.</li>
3482 </ul>
3483 If the referrer object is an interface, then the field
3484 indices are determined as follows:
3485 <ul>
3486 <li>make a list of the fields directly declared in
3487 <i>I</i>.</li>
3488 <li>Within this list, put
3489 the fields in the order returned by
3490 <functionlink id="GetClassFields"/>.</li>
3491 <li>Assign the fields in this list indices
3492 <i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i>
3493 is the count of the fields in all the superinterfaces
3494 of <i>I</i>.</li>
3495 </ul>
3496 All fields are included in this computation, regardless of
3497 field modifier (static, public, private, etc).
3498 <p/>
3499 For example, given the following classes and interfaces:
3500 <example>
3501 interface I0 {
3502 int p = 0;
3503 }
3504
3505 interface I1 extends I0 {
3506 int x = 1;
3507 }
3508
3509 interface I2 extends I0 {
3510 int y = 2;
3511 }
3512
3513 class C1 implements I1 {
3514 public static int a = 3;
3515 private int b = 4;
3516 }
3517
3518 class C2 extends C1 implements I2 {
3519 static int q = 5;
3520 final int r = 6;
3521 }
3522 </example>
3523 Assume that <functionlink id="GetClassFields"/> called on
3524 <code>C1</code> returns the fields of <code>C1</code> in the
3525 order: a, b; and that the fields of <code>C2</code> are
3526 returned in the order: q, r.
3527 An instance of class <code>C1</code> will have the
3528 following field indices:
3529 <dl><dd><table>
3530 <tr>
3531 <td>
3532 a
3533 </td>
3534 <td>
3535 2
3536 </td>
3537 <td align="left">
3538 The count of the fields in the interfaces
3539 implemented by <code>C1</code> is two (<i>n</i>=2):
3540 <code>p</code> of <code>I0</code>
3541 and <code>x</code> of <code>I1</code>.
3542 </td>
3543 </tr>
3544 <tr>
3545 <td>
3546 b
3547 </td>
3548 <td>
3549 3
3550 </td>
3551 <td align="left">
3552 the subsequent index.
3553 </td>
3554 </tr>
3555 </table></dd></dl>
3556 The class <code>C1</code> will have the same field indices.
3557 <p/>
3558 An instance of class <code>C2</code> will have the
3559 following field indices:
3560 <dl><dd><table>
3561 <tr>
3562 <td>
3563 a
3564 </td>
3565 <td>
3566 3
3567 </td>
3568 <td align="left">
3569 The count of the fields in the interfaces
3570 implemented by <code>C2</code> is three (<i>n</i>=3):
3571 <code>p</code> of <code>I0</code>,
3572 <code>x</code> of <code>I1</code> and <code>y</code> of <code>I2</code>
3573 (an interface of <code>C2</code>). Note that the field <code>p</code>
3574 of <code>I0</code> is only included once.
3575 </td>
3576 </tr>
3577 <tr>
3578 <td>
3579 b
3580 </td>
3581 <td>
3582 4
3583 </td>
3584 <td align="left">
3585 the subsequent index to "a".
3586 </td>
3587 </tr>
3588 <tr>
3589 <td>
3590 q
3591 </td>
3592 <td>
3593 5
3594 </td>
3595 <td align="left">
3596 the subsequent index to "b".
3597 </td>
3598 </tr>
3599 <tr>
3600 <td>
3601 r
3602 </td>
3603 <td>
3604 6
3605 </td>
3606 <td align="left">
3607 the subsequent index to "q".
3608 </td>
3609 </tr>
3610 </table></dd></dl>
3611 The class <code>C2</code> will have the same field indices.
3612 Note that a field may have a different index depending on the
3613 object that is viewing it -- for example field "a" above.
3614 Note also: not all field indices may be visible from the
3615 callbacks, but all indices are shown for illustrative purposes.
3616 <p/>
3617 The interface <code>I1</code> will have the
3618 following field indices:
3619 <dl><dd><table>
3620 <tr>
3621 <td>
3622 x
3623 </td>
3624 <td>
3625 1
3626 </td>
3627 <td align="left">
3628 The count of the fields in the superinterfaces
3629 of <code>I1</code> is one (<i>n</i>=1):
3630 <code>p</code> of <code>I0</code>.
3631 </td>
3632 </tr>
3633 </table></dd></dl>
3634 </description>
3635 </field>
3636 </typedef>
3637
3638 <typedef id="jvmtiHeapReferenceInfoArray"
3639 label="Reference information structure for Array references"
3640 since="1.1">
3641 <description>
3642 Reference information returned for
3643 <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references.
3644 </description>
3645 <field id="index">
3646 <jint/>
3647 <description>
3648 The array index.
3649 </description>
3650 </field>
3651 </typedef>
3652
3653 <typedef id="jvmtiHeapReferenceInfoConstantPool"
3654 label="Reference information structure for Constant Pool references"
3655 since="1.1">
3656 <description>
3657 Reference information returned for
3658 <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references.
3659 </description>
3660 <field id="index">
3661 <jint/>
3662 <description>
3663 The index into the constant pool of the class. See the description in
3664 <vmspec chapter="4.4"/>.
3665 </description>
3666 </field>
3667 </typedef>
3668
3669 <typedef id="jvmtiHeapReferenceInfoStackLocal"
3670 label="Reference information structure for Local Variable references"
3671 since="1.1">
3672 <description>
3673 Reference information returned for
3674 <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references.
3675 </description>
3676 <field id="thread_tag">
3677 <jlong/>
3678 <description>
3679 The tag of the thread corresponding to this stack, zero if not tagged.
3680 </description>
3681 </field>
3682 <field id="thread_id">
3683 <jlong/>
3684 <description>
3685 The unique thread ID of the thread corresponding to this stack.
3686 </description>
3687 </field>
3688 <field id="depth">
3689 <jint/>
3690 <description>
3691 The depth of the frame.
3692 </description>
3693 </field>
3694 <field id="method">
3695 <jmethodID/>
3696 <description>
3697 The method executing in this frame.
3698 </description>
3699 </field>
3700 <field id="location">
3701 <jlocation/>
3702 <description>
3703 The currently executing location in this frame.
3704 </description>
3705 </field>
3706 <field id="slot">
3707 <jint/>
3708 <description>
3709 The slot number of the local variable.
3710 </description>
3711 </field>
3712 </typedef>
3713
3714 <typedef id="jvmtiHeapReferenceInfoJniLocal"
3715 label="Reference information structure for JNI local references"
3716 since="1.1">
3717 <description>
3718 Reference information returned for
3719 <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references.
3720 </description>
3721 <field id="thread_tag">
3722 <jlong/>
3723 <description>
3724 The tag of the thread corresponding to this stack, zero if not tagged.
3725 </description>
3726 </field>
3727 <field id="thread_id">
3728 <jlong/>
3729 <description>
3730 The unique thread ID of the thread corresponding to this stack.
3731 </description>
3732 </field>
3733 <field id="depth">
3734 <jint/>
3735 <description>
3736 The depth of the frame.
3737 </description>
3738 </field>
3739 <field id="method">
3740 <jmethodID/>
3741 <description>
3742 The method executing in this frame.
3743 </description>
3744 </field>
3745 </typedef>
3746
3747 <typedef id="jvmtiHeapReferenceInfoReserved"
3748 label="Reference information structure for Other references"
3749 since="1.1">
3750 <description>
3751 Reference information returned for other references.
3752 </description>
3753 <field id="reserved1">
3754 <jlong/>
3755 <description>
3756 reserved for future use.
3757 </description>
3758 </field>
3759 <field id="reserved2">
3760 <jlong/>
3761 <description>
3762 reserved for future use.
3763 </description>
3764 </field>
3765 <field id="reserved3">
3766 <jlong/>
3767 <description>
3768 reserved for future use.
3769 </description>
3770 </field>
3771 <field id="reserved4">
3772 <jlong/>
3773 <description>
3774 reserved for future use.
3775 </description>
3776 </field>
3777 <field id="reserved5">
3778 <jlong/>
3779 <description>
3780 reserved for future use.
3781 </description>
3782 </field>
3783 <field id="reserved6">
3784 <jlong/>
3785 <description>
3786 reserved for future use.
3787 </description>
3788 </field>
3789 <field id="reserved7">
3790 <jlong/>
3791 <description>
3792 reserved for future use.
3793 </description>
3794 </field>
3795 <field id="reserved8">
3796 <jlong/>
3797 <description>
3798 reserved for future use.
3799 </description>
3800 </field>
3801 </typedef>
3802
3803 <uniontypedef id="jvmtiHeapReferenceInfo"
3804 label="Reference information structure"
3805 since="1.1">
3806 <description>
3807 The information returned about referrers.
3808 Represented as a union of the various kinds of reference information.
3809 </description>
3810 <field id="field">
3811 <struct>jvmtiHeapReferenceInfoField</struct>
3812 <description>
3813 The referrer information for
3814 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>
3815 and <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references.
3816 </description>
3817 </field>
3818 <field id="array">
3819 <struct>jvmtiHeapReferenceInfoArray</struct>
3820 <description>
3821 The referrer information for
3822 For <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references.
3823 </description>
3824 </field>
3825 <field id="constant_pool">
3826 <struct>jvmtiHeapReferenceInfoConstantPool</struct>
3827 <description>
3828 The referrer information for
3829 For <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references.
3830 </description>
3831 </field>
3832 <field id="stack_local">
3833 <struct>jvmtiHeapReferenceInfoStackLocal</struct>
3834 <description>
3835 The referrer information for
3836 For <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references.
3837 </description>
3838 </field>
3839 <field id="jni_local">
3840 <struct>jvmtiHeapReferenceInfoJniLocal</struct>
3841 <description>
3842 The referrer information for
3843 For <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references.
3844 </description>
3845 </field>
3846 <field id="other">
3847 <struct>jvmtiHeapReferenceInfoReserved</struct>
3848 <description>
3849 reserved for future use.
3850 </description>
3851 </field>
3852 </uniontypedef>
3853
3854 <typedef id="jvmtiHeapCallbacks"
3855 label="Heap callback function structure"
3856 since="1.1">
3857 <field id="heap_iteration_callback">
3858 <ptrtype>
3859 <struct>jvmtiHeapIterationCallback</struct>
3860 </ptrtype>
3861 <description>
3862 The callback to be called to describe an
3863 object in the heap. Used by the
3864 <functionlink id="IterateThroughHeap"/> function, ignored by the
3865 <functionlink id="FollowReferences"/> function.
3866 </description>
3867 </field>
3868 <field id="heap_reference_callback">
3869 <ptrtype>
3870 <struct>jvmtiHeapReferenceCallback</struct>
3871 </ptrtype>
3872 <description>
3873 The callback to be called to describe an
3874 object reference. Used by the
3875 <functionlink id="FollowReferences"/> function, ignored by the
3876 <functionlink id="IterateThroughHeap"/> function.
3877 </description>
3878 </field>
3879 <field id="primitive_field_callback">
3880 <ptrtype>
3881 <struct>jvmtiPrimitiveFieldCallback</struct>
3882 </ptrtype>
3883 <description>
3884 The callback to be called to describe a
3885 primitive field.
3886 </description>
3887 </field>
3888 <field id="array_primitive_value_callback">
3889 <ptrtype>
3890 <struct>jvmtiArrayPrimitiveValueCallback</struct>
3891 </ptrtype>
3892 <description>
3893 The callback to be called to describe an
3894 array of primitive values.
3895 </description>
3896 </field>
3897 <field id="string_primitive_value_callback">
3898 <ptrtype>
3899 <struct>jvmtiStringPrimitiveValueCallback</struct>
3900 </ptrtype>
3901 <description>
3902 The callback to be called to describe a String value.
3903 </description>
3904 </field>
3905 <field id="reserved5">
3906 <ptrtype>
3907 <struct>jvmtiReservedCallback</struct>
3908 </ptrtype>
3909 <description>
3910 Reserved for future use..
3911 </description>
3912 </field>
3913 <field id="reserved6">
3914 <ptrtype>
3915 <struct>jvmtiReservedCallback</struct>
3916 </ptrtype>
3917 <description>
3918 Reserved for future use..
3919 </description>
3920 </field>
3921 <field id="reserved7">
3922 <ptrtype>
3923 <struct>jvmtiReservedCallback</struct>
3924 </ptrtype>
3925 <description>
3926 Reserved for future use..
3927 </description>
3928 </field>
3929 <field id="reserved8">
3930 <ptrtype>
3931 <struct>jvmtiReservedCallback</struct>
3932 </ptrtype>
3933 <description>
3934 Reserved for future use..
3935 </description>
3936 </field>
3937 <field id="reserved9">
3938 <ptrtype>
3939 <struct>jvmtiReservedCallback</struct>
3940 </ptrtype>
3941 <description>
3942 Reserved for future use..
3943 </description>
3944 </field>
3945 <field id="reserved10">
3946 <ptrtype>
3947 <struct>jvmtiReservedCallback</struct>
3948 </ptrtype>
3949 <description>
3950 Reserved for future use..
3951 </description>
3952 </field>
3953 <field id="reserved11">
3954 <ptrtype>
3955 <struct>jvmtiReservedCallback</struct>
3956 </ptrtype>
3957 <description>
3958 Reserved for future use..
3959 </description>
3960 </field>
3961 <field id="reserved12">
3962 <ptrtype>
3963 <struct>jvmtiReservedCallback</struct>
3964 </ptrtype>
3965 <description>
3966 Reserved for future use..
3967 </description>
3968 </field>
3969 <field id="reserved13">
3970 <ptrtype>
3971 <struct>jvmtiReservedCallback</struct>
3972 </ptrtype>
3973 <description>
3974 Reserved for future use..
3975 </description>
3976 </field>
3977 <field id="reserved14">
3978 <ptrtype>
3979 <struct>jvmtiReservedCallback</struct>
3980 </ptrtype>
3981 <description>
3982 Reserved for future use..
3983 </description>
3984 </field>
3985 <field id="reserved15">
3986 <ptrtype>
3987 <struct>jvmtiReservedCallback</struct>
3988 </ptrtype>
3989 <description>
3990 Reserved for future use..
3991 </description>
3992 </field>
3993 </typedef>
3994
3995
3996 <intro>
3997 <rationale>
3998 The heap dumping functionality (below) uses a callback
3999 for each object. While it would seem that a buffered approach
4000 would provide better throughput, tests do
4001 not show this to be the case--possibly due to locality of
4002 memory reference or array access overhead.
4003 </rationale>
4004
4005 <issue>
4006 Still under investigation as to if java.lang.ref references
4007 are reported as a different type of reference.
4008 </issue>
4009
4010 <issue>
4011 Should or can an indication of the cost or relative cost of
4012 these operations be included?
4013 </issue>
4014
4015 </intro>
4016
4017 <callback id="jvmtiHeapIterationCallback" since="1.1">
4018 <jint/>
4019 <synopsis>Heap Iteration Callback</synopsis>
4020 <description>
4021 Agent supplied callback function.
4022 Describes (but does not pass in) an object in the heap.
4023 <p/>
4024 This function should return a bit vector of the desired
4025 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4026 This will determine if the entire iteration should be aborted
4027 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4028 <p/>
4029 See the <internallink id="heapCallbacks">heap callback
4030 function restrictions</internallink>.
4031 </description>
4032 <parameters>
4033 <param id="class_tag">
4034 <jlong/>
4035 <description>
4036 The tag of the class of object (zero if the class is not tagged).
4037 If the object represents a runtime class,
4038 the <code>class_tag</code> is the tag
4039 associated with <code>java.lang.Class</code>
4040 (zero if <code>java.lang.Class</code> is not tagged).
4041 </description>
4042 </param>
4043 <param id="size">
4044 <jlong/>
4045 <description>
4046 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
4047 </description>
4048 </param>
4049 <param id="tag_ptr">
4050 <outptr><jlong/></outptr>
4051 <description>
4052 The object tag value, or zero if the object is not tagged.
4053 To set the tag value to be associated with the object
4054 the agent sets the <code>jlong</code> pointed to by the parameter.
4055 </description>
4056 </param>
4057 <param id="length">
4058 <jint/>
4059 <description>
4060 If this object is an array, the length of the array. Otherwise negative one (-1).
4061 </description>
4062 </param>
4063 <param id="user_data">
4064 <outptr><void/></outptr>
4065 <description>
4066 The user supplied data that was passed into the iteration function.
4067 </description>
4068 </param>
4069 </parameters>
4070 </callback>
4071
4072 <callback id="jvmtiHeapReferenceCallback" since="1.1">
4073 <jint/>
4074 <synopsis>Heap Reference Callback</synopsis>
4075 <description>
4076 Agent supplied callback function.
4077 Describes a reference from an object or the VM (the referrer) to another object
4078 (the referree) or a heap root to a referree.
4079 <p/>
4080 This function should return a bit vector of the desired
4081 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4082 This will determine if the objects referenced by the referree
4083 should be visited or if the entire iteration should be aborted.
4084 <p/>
4085 See the <internallink id="heapCallbacks">heap callback
4086 function restrictions</internallink>.
4087 </description>
4088 <parameters>
4089 <param id="reference_kind">
4090 <enum>jvmtiHeapReferenceKind</enum>
4091 <description>
4092 The kind of reference.
4093 </description>
4094 </param>
4095 <param id="reference_info">
4096 <inptr>
4097 <struct>jvmtiHeapReferenceInfo</struct>
4098 </inptr>
4099 <description>
4100 Details about the reference.
4101 Set when the <datalink id="jvmtiHeapReferenceCallback.reference_kind">reference_kind</datalink> is
4102 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>,
4103 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>,
4104 <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/>,
4105 <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/>,
4106 <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/>,
4107 or <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/>.
4108 Otherwise <code>NULL</code>.
4109 </description>
4110 </param>
4111 <param id="class_tag">
4112 <jlong/>
4113 <description>
4114 The tag of the class of referree object (zero if the class is not tagged).
4115 If the referree object represents a runtime class,
4116 the <code>class_tag</code> is the tag
4117 associated with <code>java.lang.Class</code>
4118 (zero if <code>java.lang.Class</code> is not tagged).
4119 </description>
4120 </param>
4121 <param id="referrer_class_tag">
4122 <jlong/>
4123 <description>
4124 The tag of the class of the referrer object (zero if the class is not tagged
4125 or the referree is a heap root). If the referrer object represents a runtime
4126 class, the <code>referrer_class_tag</code> is the tag associated with
4127 the <code>java.lang.Class</code>
4128 (zero if <code>java.lang.Class</code> is not tagged).
4129 </description>
4130 </param>
4131 <param id="size">
4132 <jlong/>
4133 <description>
4134 Size of the referree object (in bytes).
4135 See <functionlink id="GetObjectSize"/>.
4136 </description>
4137 </param>
4138 <param id="tag_ptr">
4139 <outptr><jlong/></outptr>
4140 <description>
4141 Points to the referree object tag value, or zero if the object is not
4142 tagged.
4143 To set the tag value to be associated with the object
4144 the agent sets the <code>jlong</code> pointed to by the parameter.
4145 </description>
4146 </param>
4147 <param id="referrer_tag_ptr">
4148 <outptr><jlong/></outptr>
4149 <description>
4150 Points to the tag of the referrer object, or
4151 points to the zero if the referrer
4152 object is not tagged.
4153 <code>NULL</code> if the referrer in not an object (that is,
4154 this callback is reporting a heap root).
4155 To set the tag value to be associated with the referrer object
4156 the agent sets the <code>jlong</code> pointed to by the parameter.
4157 If this callback is reporting a reference from an object to itself,
4158 <code>referrer_tag_ptr == tag_ptr</code>.
4159 </description>
4160 </param>
4161 <param id="length">
4162 <jint/>
4163 <description>
4164 If this object is an array, the length of the array. Otherwise negative one (-1).
4165 </description>
4166 </param>
4167 <param id="user_data">
4168 <outptr><void/></outptr>
4169 <description>
4170 The user supplied data that was passed into the iteration function.
4171 </description>
4172 </param>
4173 </parameters>
4174 </callback>
4175
4176 <callback id="jvmtiPrimitiveFieldCallback" since="1.1">
4177 <jint/>
4178 <synopsis>Primitive Field Callback</synopsis>
4179 <description>
4180 Agent supplied callback function which
4181 describes a primitive field of an object (<i>the object</i>).
4182 A primitive field is a field whose type is a primitive type.
4183 This callback will describe a static field if the object is a class,
4184 and otherwise will describe an instance field.
4185 <p/>
4186 This function should return a bit vector of the desired
4187 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4188 This will determine if the entire iteration should be aborted
4189 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4190 <p/>
4191 See the <internallink id="heapCallbacks">heap callback
4192 function restrictions</internallink>.
4193 </description>
4194 <parameters>
4195 <param id="kind">
4196 <enum>jvmtiHeapReferenceKind</enum>
4197 <description>
4198 The kind of field -- instance or static (<datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> or
4199 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>).
4200 </description>
4201 </param>
4202 <param id="info">
4203 <inptr>
4204 <struct>jvmtiHeapReferenceInfo</struct>
4205 </inptr>
4206 <description>
4207 Which field (the field index).
4208 </description>
4209 </param>
4210 <param id="object_class_tag">
4211 <jlong/>
4212 <description>
4213 The tag of the class of the object (zero if the class is not tagged).
4214 If the object represents a runtime class, the
4215 <code>object_class_tag</code> is the tag
4216 associated with <code>java.lang.Class</code>
4217 (zero if <code>java.lang.Class</code> is not tagged).
4218 </description>
4219 </param>
4220 <param id="object_tag_ptr">
4221 <outptr><jlong/></outptr>
4222 <description>
4223 Points to the tag of the object, or zero if the object is not
4224 tagged.
4225 To set the tag value to be associated with the object
4226 the agent sets the <code>jlong</code> pointed to by the parameter.
4227 </description>
4228 </param>
4229 <param id="value">
4230 <jvalue/>
4231 <description>
4232 The value of the field.
4233 </description>
4234 </param>
4235 <param id="value_type">
4236 <enum>jvmtiPrimitiveType</enum>
4237 <description>
4238 The type of the field.
4239 </description>
4240 </param>
4241 <param id="user_data">
4242 <outptr><void/></outptr>
4243 <description>
4244 The user supplied data that was passed into the iteration function.
4245 </description>
4246 </param>
4247 </parameters>
4248 </callback>
4249
4250 <callback id="jvmtiArrayPrimitiveValueCallback" since="1.1">
4251 <jint/>
4252 <synopsis>Array Primitive Value Callback</synopsis>
4253 <description>
4254 Agent supplied callback function.
4255 Describes the values in an array of a primitive type.
4256 <p/>
4257 This function should return a bit vector of the desired
4258 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4259 This will determine if the entire iteration should be aborted
4260 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4261 <p/>
4262 See the <internallink id="heapCallbacks">heap callback
4263 function restrictions</internallink>.
4264 </description>
4265 <parameters>
4266 <param id="class_tag">
4267 <jlong/>
4268 <description>
4269 The tag of the class of the array object (zero if the class is not tagged).
4270 </description>
4271 </param>
4272 <param id="size">
4273 <jlong/>
4274 <description>
4275 Size of the array (in bytes).
4276 See <functionlink id="GetObjectSize"/>.
4277 </description>
4278 </param>
4279 <param id="tag_ptr">
4280 <outptr><jlong/></outptr>
4281 <description>
4282 Points to the tag of the array object, or zero if the object is not
4283 tagged.
4284 To set the tag value to be associated with the object
4285 the agent sets the <code>jlong</code> pointed to by the parameter.
4286 </description>
4287 </param>
4288 <param id="element_count">
4289 <jint/>
4290 <description>
4291 The length of the primitive array.
4292 </description>
4293 </param>
4294 <param id="element_type">
4295 <enum>jvmtiPrimitiveType</enum>
4296 <description>
4297 The type of the elements of the array.
4298 </description>
4299 </param>
4300 <param id="elements">
4301 <vmbuf><void/></vmbuf>
4302 <description>
4303 The elements of the array in a packed array of <code>element_count</code>
4304 items of <code>element_type</code> size each.
4305 </description>
4306 </param>
4307 <param id="user_data">
4308 <outptr><void/></outptr>
4309 <description>
4310 The user supplied data that was passed into the iteration function.
4311 </description>
4312 </param>
4313 </parameters>
4314 </callback>
4315
4316 <callback id="jvmtiStringPrimitiveValueCallback" since="1.1">
4317 <jint/>
4318 <synopsis>String Primitive Value Callback</synopsis>
4319 <description>
4320 Agent supplied callback function.
4321 Describes the value of a java.lang.String.
4322 <p/>
4323 This function should return a bit vector of the desired
4324 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4325 This will determine if the entire iteration should be aborted
4326 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4327 <p/>
4328 See the <internallink id="heapCallbacks">heap callback
4329 function restrictions</internallink>.
4330 </description>
4331 <parameters>
4332 <param id="class_tag">
4333 <jlong/>
4334 <description>
4335 The tag of the class of the String class (zero if the class is not tagged).
4336 <issue>Is this needed?</issue>
4337 </description>
4338 </param>
4339 <param id="size">
4340 <jlong/>
4341 <description>
4342 Size of the string (in bytes).
4343 See <functionlink id="GetObjectSize"/>.
4344 </description>
4345 </param>
4346 <param id="tag_ptr">
4347 <outptr><jlong/></outptr>
4348 <description>
4349 Points to the tag of the String object, or zero if the object is not
4350 tagged.
4351 To set the tag value to be associated with the object
4352 the agent sets the <code>jlong</code> pointed to by the parameter.
4353 </description>
4354 </param>
4355 <param id="value">
4356 <vmbuf><jchar/></vmbuf>
4357 <description>
4358 The value of the String, encoded as a Unicode string.
4359 </description>
4360 </param>
4361 <param id="value_length">
4362 <jint/>
4363 <description>
4364 The length of the string.
4365 The length is equal to the number of 16-bit Unicode
4366 characters in the string.
4367 </description>
4368 </param>
4369 <param id="user_data">
4370 <outptr><void/></outptr>
4371 <description>
4372 The user supplied data that was passed into the iteration function.
4373 </description>
4374 </param>
4375 </parameters>
4376 </callback>
4377
4378
4379 <callback id="jvmtiReservedCallback" since="1.1">
4380 <jint/>
4381 <synopsis>reserved for future use Callback</synopsis>
4382 <description>
4383 Placeholder -- reserved for future use.
4384 </description>
4385 <parameters>
4386 </parameters>
4387 </callback>
4388
4389 <function id="FollowReferences" num="115" since="1.1">
4390 <synopsis>Follow References</synopsis>
4391 <description>
4392 This function initiates a traversal over the objects that are
4393 directly and indirectly reachable from the specified object or,
4394 if <code>initial_object</code> is not specified, all objects
4395 reachable from the heap roots.
4396 The heap root are the set of system classes,
4397 JNI globals, references from thread stacks, and other objects used as roots
4398 for the purposes of garbage collection.
4399 <p/>
4400 This function operates by traversing the reference graph.
4401 Let <i>A</i>, <i>B</i>, ... represent objects.
4402 When a reference from <i>A</i> to <i>B</i> is traversed,
4403 when a reference from a heap root to <i>B</i> is traversed,
4404 or when <i>B</i> is specified as the <paramlink id="initial_object"/>,
4405 then <i>B</i> is said to be <i>visited</i>.
4406 A reference from <i>A</i> to <i>B</i> is not traversed until <i>A</i>
4407 is visited.
4408 References are reported in the same order that the references are traversed.
4409 Object references are reported by invoking the agent supplied
4410 callback function <functionlink id="jvmtiHeapReferenceCallback"/>.
4411 In a reference from <i>A</i> to <i>B</i>, <i>A</i> is known
4412 as the <i>referrer</i> and <i>B</i> as the <i>referree</i>.
4413 The callback is invoked exactly once for each reference from a referrer;
4414 this is true even if there are reference cycles or multiple paths to
4415 the referrer.
4416 There may be more than one reference between a referrer and a referree,
4417 each reference is reported.
4418 These references may be distinguished by examining the
4419 <datalink
4420 id="jvmtiHeapReferenceCallback.reference_kind"><code>reference_kind</code></datalink>
4421 and
4422 <datalink
4423 id="jvmtiHeapReferenceCallback.reference_info"><code>reference_info</code></datalink>
4424 parameters of the <functionlink id="jvmtiHeapReferenceCallback"/> callback.
4425 <p/>
4426 This function reports a Java programming language view of object references,
4427 not a virtual machine implementation view. The following object references
4428 are reported when they are non-null:
4429 <ul>
4430 <li>Instance objects report references to each non-primitive instance fields
4431 (including inherited fields).</li>
4432 <li>Instance objects report a reference to the object type (class).</li>
4433 <li>Classes report a reference to the superclass and directly
4434 implemented/extended interfaces.</li>
4435 <li>Classes report a reference to the class loader, protection domain,
4436 signers, and resolved entries in the constant pool.</li>
4437 <li>Classes report a reference to each directly declared non-primitive
4438 static field.</li>
4439 <li>Arrays report a reference to the array type (class) and each
4440 array element.</li>
4441 <li>Primitive arrays report a reference to the array type.</li>
4442 </ul>
4443 <p/>
4444 This function can also be used to examine primitive (non-object) values.
4445 The primitive value of an array or String
4446 is reported after the object has been visited;
4447 it is reported by invoking the agent supplied callback function
4448 <functionlink id="jvmtiArrayPrimitiveValueCallback"/> or
4449 <functionlink id="jvmtiStringPrimitiveValueCallback"/>.
4450 A primitive field
4451 is reported after the object with that field is visited;
4452 it is reported by invoking the agent supplied callback function
4453 <functionlink id="jvmtiPrimitiveFieldCallback"/>.
4454 <p/>
4455 Whether a callback is provided or is <code>NULL</code> only determines
4456 whether the callback will be invoked, it does not influence
4457 which objects are visited nor does it influence whether other callbacks
4458 will be invoked.
4459 However, the
4460 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>
4461 returned by <functionlink id="jvmtiHeapReferenceCallback"/>
4462 do determine if the objects referenced by the
4463 current object as visited.
4464 The <datalink id="jvmtiHeapFilter">heap filter flags</datalink>
4465 and <paramlink id="klass"/> provided as parameters to this function
4466 do not control which objects are visited but they do control which
4467 objects and primitive values are reported by the callbacks.
4468 For example, if the only callback that was set is
4469 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> and <code>klass</code>
4470 is set to the array of bytes class, then only arrays of byte will be
4471 reported.
4472 The table below summarizes this:
4473 <p/>
4474 <table>
4475 <tr>
4476 <th/>
4477 <th>
4478 Controls objects visited
4479 </th>
4480 <th>
4481 Controls objects reported
4482 </th>
4483 <th>
4484 Controls primitives reported
4485 </th>
4486 </tr>
4487 <tr>
4488 <th align="left">
4489 the
4490 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4491 returned by <functionlink id="jvmtiHeapReferenceCallback"/>
4492 </th>
4493 <td>
4494 <b>Yes</b>
4495 </td>
4496 <td>
4497 <b>Yes</b>, since visits are controlled
4498 </td>
4499 <td>
4500 <b>Yes</b>, since visits are controlled
4501 </td>
4502 </tr>
4503 <tr>
4504 <th align="left">
4505 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/>
4506 in <paramlink id="callbacks"/> set
4507 </th>
4508 <td>
4509 No
4510 </td>
4511 <td>
4512 <b>Yes</b>
4513 </td>
4514 <td>
4515 No
4516 </td>
4517 </tr>
4518 <tr>
4519 <th align="left">
4520 <paramlink id="heap_filter"/>
4521 </th>
4522 <td>
4523 No
4524 </td>
4525 <td>
4526 <b>Yes</b>
4527 </td>
4528 <td>
4529 <b>Yes</b>
4530 </td>
4531 </tr>
4532 <tr>
4533 <th align="left">
4534 <paramlink id="klass"/>
4535 </th>
4536 <td>
4537 No
4538 </td>
4539 <td>
4540 <b>Yes</b>
4541 </td>
4542 <td>
4543 <b>Yes</b>
4544 </td>
4545 </tr>
4546 </table>
4547 <p/>
4548 During the execution of this function the state of the heap
4549 does not change: no objects are allocated, no objects are
4550 garbage collected, and the state of objects (including
4551 held values) does not change.
4552 As a result, threads executing Java
4553 programming language code, threads attempting to resume the
4554 execution of Java programming language code, and threads
4555 attempting to execute JNI functions are typically stalled.
4556 </description>
4557 <origin>new</origin>
4558 <capabilities>
4559 <required id="can_tag_objects"></required>
4560 </capabilities>
4561 <parameters>
4562 <param id="heap_filter">
4563 <jint/>
4564 <description>
4565 This bit vector of
4566 <datalink id="jvmtiHeapFilter">heap filter flags</datalink>.
4567 restricts the objects for which the callback function is called.
4568 This applies to both the object and primitive callbacks.
4569 </description>
4570 </param>
4571 <param id="klass">
4572 <ptrtype>
4573 <jclass/>
4574 <nullok>callbacks are not limited to instances of a particular
4575 class</nullok>
4576 </ptrtype>
4577 <description>
4578 Callbacks are only reported when the object is an instance of
4579 this class.
4580 Objects which are instances of a subclass of <code>klass</code>
4581 are not reported.
4582 If <code>klass</code> is an interface, no objects are reported.
4583 This applies to both the object and primitive callbacks.
4584 </description>
4585 </param>
4586 <param id="initial_object">
4587 <ptrtype>
4588 <jobject/>
4589 <nullok>references are followed from the heap roots</nullok>
4590 </ptrtype>
4591 <description>
4592 The object to follow
4593 </description>
4594 </param>
4595 <param id="callbacks">
4596 <inptr>
4597 <struct>jvmtiHeapCallbacks</struct>
4598 </inptr>
4599 <description>
4600 Structure defining the set of callback functions.
4601 </description>
4602 </param>
4603 <param id="user_data">
4604 <inbuf>
4605 <void/>
4606 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
4607 </inbuf>
4608 <description>
4609 User supplied data to be passed to the callback.
4610 </description>
4611 </param>
4612 </parameters>
4613 <errors>
4614 <error id="JVMTI_ERROR_INVALID_CLASS">
4615 <paramlink id="klass"/> is not a valid class.
4616 </error>
4617 <error id="JVMTI_ERROR_INVALID_OBJECT">
4618 <paramlink id="initial_object"/> is not a valid object.
4619 </error>
4620 </errors>
4621 </function>
4622
4623
4624 <function id="IterateThroughHeap" num="116" since="1.1">
4625 <synopsis>Iterate Through Heap</synopsis>
4626 <description>
4627 Initiate an iteration over all objects in the heap.
4628 This includes both reachable and
4629 unreachable objects. Objects are visited in no particular order.
4630 <p/>
4631 Heap objects are reported by invoking the agent supplied
4632 callback function <functionlink id="jvmtiHeapIterationCallback"/>.
4633 References between objects are not reported.
4634 If only reachable objects are desired, or if object reference information
4635 is needed, use <functionlink id="FollowReferences"/>.
4636 <p/>
4637 This function can also be used to examine primitive (non-object) values.
4638 The primitive value of an array or String
4639 is reported after the object has been visited;
4640 it is reported by invoking the agent supplied callback function
4641 <functionlink id="jvmtiArrayPrimitiveValueCallback"/> or
4642 <functionlink id="jvmtiStringPrimitiveValueCallback"/>.
4643 A primitive field
4644 is reported after the object with that field is visited;
4645 it is reported by invoking the agent supplied
4646 callback function
4647 <functionlink id="jvmtiPrimitiveFieldCallback"/>.
4648 <p/>
4649 Unless the iteration is aborted by the
4650 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4651 returned by a callback, all objects in the heap are visited.
4652 Whether a callback is provided or is <code>NULL</code> only determines
4653 whether the callback will be invoked, it does not influence
4654 which objects are visited nor does it influence whether other callbacks
4655 will be invoked.
4656 The <datalink id="jvmtiHeapFilter">heap filter flags</datalink>
4657 and <paramlink id="klass"/> provided as parameters to this function
4658 do not control which objects are visited but they do control which
4659 objects and primitive values are reported by the callbacks.
4660 For example, if the only callback that was set is
4661 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> and <code>klass</code>
4662 is set to the array of bytes class, then only arrays of byte will be
4663 reported. The table below summarizes this (contrast this with
4664 <functionlink id="FollowReferences"/>):
4665 <p/>
4666 <table>
4667 <tr>
4668 <th/>
4669 <th>
4670 Controls objects visited
4671 </th>
4672 <th>
4673 Controls objects reported
4674 </th>
4675 <th>
4676 Controls primitives reported
4677 </th>
4678 </tr>
4679 <tr>
4680 <th align="left">
4681 the
4682 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4683 returned by <functionlink id="jvmtiHeapIterationCallback"/>
4684 </th>
4685 <td>
4686 No<br/>(unless they abort the iteration)
4687 </td>
4688 <td>
4689 No<br/>(unless they abort the iteration)
4690 </td>
4691 <td>
4692 No<br/>(unless they abort the iteration)
4693 </td>
4694 </tr>
4695 <tr>
4696 <th align="left">
4697 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/>
4698 in <paramlink id="callbacks"/> set
4699 </th>
4700 <td>
4701 No
4702 </td>
4703 <td>
4704 <b>Yes</b>
4705 </td>
4706 <td>
4707 No
4708 </td>
4709 </tr>
4710 <tr>
4711 <th align="left">
4712 <paramlink id="heap_filter"/>
4713 </th>
4714 <td>
4715 No
4716 </td>
4717 <td>
4718 <b>Yes</b>
4719 </td>
4720 <td>
4721 <b>Yes</b>
4722 </td>
4723 </tr>
4724 <tr>
4725 <th align="left">
4726 <paramlink id="klass"/>
4727 </th>
4728 <td>
4729 No
4730 </td>
4731 <td>
4732 <b>Yes</b>
4733 </td>
4734 <td>
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_modules"></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_modules"></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.
6818 </description>
6819 <origin>new</origin>
6820 <capabilities>
6821 </capabilities>
6822 <parameters>
6823 <param id="module">
6824 <ptrtype><jobject/></ptrtype>
6825 <description>
6826 The module to query.
6827 </description>
6828 </param>
6829 <param id="is_modifiable_module_ptr">
6830 <outptr><jboolean/></outptr>
6831 <description>
6832 On return, points to the boolean result of this function.
6833 </description>
6834 </param>
6835 </parameters>
6836 <errors>
6837 <error id="JVMTI_ERROR_INVALID_MODULE">
6838 If <paramlink id="module"></paramlink> is not a module object.
6839 </error>
6840 </errors>
6841 </function>
6842
6843 </category>
6844
6845 <category id="class" label="Class">
6846
6847 <intro>
6848 </intro>
6849
6850 <function id="GetLoadedClasses" jkernel="yes" num="78">
6851 <synopsis>Get Loaded Classes</synopsis>
6852 <description>
6853 Return an array of all classes loaded in the virtual machine.
6854 The number of classes in the array is returned via
6855 <code>class_count_ptr</code>, and the array itself via
6856 <code>classes_ptr</code>.
6857 <p/>
6858 Array classes of all types (including arrays of primitive types) are
6859 included in the returned list. Primitive classes (for example,
6860 <code>java.lang.Integer.TYPE</code>) are <i>not</i> included in this list.
6861 </description>
6862 <origin>jvmdi</origin>
6863 <capabilities>
6864 </capabilities>
6865 <parameters>
6866 <param id="class_count_ptr">
6867 <outptr><jint/></outptr>
6868 <description>
6869 On return, points to the number of classes.
6870 </description>
6871 </param>
6872 <param id="classes_ptr">
6873 <allocbuf outcount="class_count_ptr"><jclass/></allocbuf>
6874 <description>
6875 On return, points to an array of references, one
6876 for each class.
6877 </description>
6878 </param>
6879 </parameters>
6880 <errors>
6881 </errors>
6882 </function>
6883
6884 <function id="GetClassLoaderClasses" jkernel="yes" num="79">
6885 <synopsis>Get Classloader Classes</synopsis>
6886 <description>
6887 Returns an array of those classes for which this class loader has
6888 been recorded as an initiating loader. Each
6889 class in the returned array was created by this class loader,
6890 either by defining it directly or by delegation to another class loader.
6891 See <vmspec chapter="5.3"/>.
6892 <p/>
6893 The number of classes in the array is returned via
6894 <code>class_count_ptr</code>, and the array itself via
6895 <code>classes_ptr</code>.
6896 </description>
6897 <origin>jvmdi</origin>
6898 <capabilities>
6899 </capabilities>
6900 <parameters>
6901 <param id="initiating_loader">
6902 <ptrtype>
6903 <jobject/>
6904 <nullok>the classes initiated by the bootstrap loader will be returned</nullok>
6905 </ptrtype>
6906 <description>
6907 An initiating class loader.
6908 </description>
6909 </param>
6910 <param id="class_count_ptr">
6911 <outptr><jint/></outptr>
6912 <description>
6913 On return, points to the number of classes.
6914 </description>
6915 </param>
6916 <param id="classes_ptr">
6917 <allocbuf outcount="class_count_ptr"><jclass/></allocbuf>
6918 <description>
6919 On return, points to an array of references, one
6920 for each class.
6921 </description>
6922 </param>
6923 </parameters>
6924 <errors>
6925 </errors>
6926 </function>
6927
6928 <function id="GetClassSignature" phase="start" num="48">
6929 <synopsis>Get Class Signature</synopsis>
6930 <description>
6931 For the class indicated by <code>klass</code>, return the
6932 <externallink id="docs/technotes/guides/jni/spec/types.html#type_signatures">JNI
6933 type signature</externallink>
6934 and the generic signature of the class.
6935 For example, <code>java.util.List</code> is <code>"Ljava/util/List;"</code>
6936 and <code>int[]</code> is <code>"[I"</code>
6937 The returned name for primitive classes
6938 is the type signature character of the corresponding primitive type.
6939 For example, <code>java.lang.Integer.TYPE</code> is <code>"I"</code>.
6940 </description>
6941 <origin>jvmdiClone</origin>
6942 <capabilities>
6943 </capabilities>
6944 <parameters>
6945 <param id="klass">
6946 <jclass/>
6947 <description>
6948 The class to query.
6949 </description>
6950 </param>
6951 <param id="signature_ptr">
6952 <allocbuf>
6953 <char/>
6954 <nullok>the signature is not returned</nullok>
6955 </allocbuf>
6956 <description>
6957 On return, points to the JNI type signature of the class, encoded as a
6958 <internallink id="mUTF">modified UTF-8</internallink> string.
6959 </description>
6960 </param>
6961 <param id="generic_ptr">
6962 <allocbuf>
6963 <char/>
6964 <nullok>the generic signature is not returned</nullok>
6965 </allocbuf>
6966 <description>
6967 On return, points to the generic signature of the class, encoded as a
6968 <internallink id="mUTF">modified UTF-8</internallink> string.
6969 If there is no generic signature attribute for the class, then,
6970 on return, points to <code>NULL</code>.
6971 </description>
6972 </param>
6973 </parameters>
6974 <errors>
6975 </errors>
6976 </function>
6977
6978 <function id="GetClassStatus" phase="start" num="49">
6979 <synopsis>Get Class Status</synopsis>
6980 <description>
6981 Get the status of the class. Zero or more of the following bits can be
6982 set.
6983 <constants id="jvmtiClassStatus" label="Class Status Flags" kind="bits">
6984 <constant id="JVMTI_CLASS_STATUS_VERIFIED" num="1">
6985 Class bytecodes have been verified
6986 </constant>
6987 <constant id="JVMTI_CLASS_STATUS_PREPARED" num="2">
6988 Class preparation is complete
6989 </constant>
6990 <constant id="JVMTI_CLASS_STATUS_INITIALIZED" num="4">
6991 Class initialization is complete. Static initializer has been run.
6992 </constant>
6993 <constant id="JVMTI_CLASS_STATUS_ERROR" num="8">
6994 Error during initialization makes class unusable
6995 </constant>
6996 <constant id="JVMTI_CLASS_STATUS_ARRAY" num="16">
6997 Class is an array. If set, all other bits are zero.
6998 </constant>
6999 <constant id="JVMTI_CLASS_STATUS_PRIMITIVE" num="32">
7000 Class is a primitive class (for example, <code>java.lang.Integer.TYPE</code>).
7001 If set, all other bits are zero.
7002 </constant>
7003 </constants>
7004 </description>
7005 <origin>jvmdi</origin>
7006 <capabilities>
7007 </capabilities>
7008 <parameters>
7009 <param id="klass">
7010 <jclass/>
7011 <description>
7012 The class to query.
7013 </description>
7014 </param>
7015 <param id="status_ptr">
7016 <outptr><jint/></outptr>
7017 <description>
7018 On return, points to the current state of this class as one or
7019 more of the <internallink id="jvmtiClassStatus">class status flags</internallink>.
7020 </description>
7021 </param>
7022 </parameters>
7023 <errors>
7024 </errors>
7025 </function>
7026
7027 <function id="GetSourceFileName" phase="start" num="50">
7028 <synopsis>Get Source File Name</synopsis>
7029 <description>
7030 For the class indicated by <code>klass</code>, return the source file
7031 name via <code>source_name_ptr</code>. The returned string
7032 is a file name only and never contains a directory name.
7033 <p/>
7034 For primitive classes (for example, <code>java.lang.Integer.TYPE</code>)
7035 and for arrays this function returns
7036 <errorlink id="JVMTI_ERROR_ABSENT_INFORMATION"></errorlink>.
7037 </description>
7038 <origin>jvmdi</origin>
7039 <capabilities>
7040 <required id="can_get_source_file_name"></required>
7041 </capabilities>
7042 <parameters>
7043 <param id="klass">
7044 <jclass/>
7045 <description>
7046 The class to query.
7047 </description>
7048 </param>
7049 <param id="source_name_ptr">
7050 <allocbuf><char/></allocbuf>
7051 <description>
7052 On return, points to the class's source file name, encoded as a
7053 <internallink id="mUTF">modified UTF-8</internallink> string.
7054 </description>
7055 </param>
7056 </parameters>
7057 <errors>
7058 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7059 Class information does not include a source file name. This includes
7060 cases where the class is an array class or primitive class.
7061 </error>
7062 </errors>
7063 </function>
7064
7065 <function id="GetClassModifiers" phase="start" num="51">
7066 <synopsis>Get Class Modifiers</synopsis>
7067 <description>
7068 For the class indicated by <code>klass</code>, return the access
7069 flags
7070 via <code>modifiers_ptr</code>.
7071 Access flags are defined in <vmspec chapter="4"/>.
7072 <p/>
7073 If the class is an array class, then its public, private, and protected
7074 modifiers are the same as those of its component type. For arrays of
7075 primitives, this component type is represented by one of the primitive
7076 classes (for example, <code>java.lang.Integer.TYPE</code>).
7077 <p/>
7078 If the class is a primitive class, its public modifier is always true,
7079 and its protected and private modifiers are always false.
7080 <p/>
7081 If the class is an array class or a primitive class then its final
7082 modifier is always true and its interface modifier is always false.
7083 The values of its other modifiers are not determined by this specification.
7084
7085 </description>
7086 <origin>jvmdi</origin>
7087 <capabilities>
7088 </capabilities>
7089 <parameters>
7090 <param id="klass">
7091 <jclass/>
7092 <description>
7093 The class to query.
7094 </description>
7095 </param>
7096 <param id="modifiers_ptr">
7097 <outptr><jint/></outptr>
7098 <description>
7099 On return, points to the current access flags of this class.
7100
7101 </description>
7102 </param>
7103 </parameters>
7104 <errors>
7105 </errors>
7106 </function>
7107
7108 <function id="GetClassMethods" phase="start" num="52">
7109 <synopsis>Get Class Methods</synopsis>
7110 <description>
7111 For the class indicated by <code>klass</code>, return a count of
7112 methods via <code>method_count_ptr</code> and a list of
7113 method IDs via <code>methods_ptr</code>. The method list contains
7114 constructors and static initializers as well as true methods.
7115 Only directly declared methods are returned (not inherited methods).
7116 An empty method list is returned for array classes and primitive classes
7117 (for example, <code>java.lang.Integer.TYPE</code>).
7118 </description>
7119 <origin>jvmdi</origin>
7120 <capabilities>
7121 <capability id="can_maintain_original_method_order"/>
7122 </capabilities>
7123 <parameters>
7124 <param id="klass">
7125 <jclass/>
7126 <description>
7127 The class to query.
7128 </description>
7129 </param>
7130 <param id="method_count_ptr">
7131 <outptr><jint/></outptr>
7132 <description>
7133 On return, points to the number of methods declared in this class.
7134 </description>
7135 </param>
7136 <param id="methods_ptr">
7137 <allocbuf outcount="method_count_ptr"><jmethodID class="klass"/></allocbuf>
7138 <description>
7139 On return, points to the method ID array.
7140 </description>
7141 </param>
7142 </parameters>
7143 <errors>
7144 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
7145 <paramlink id="klass"></paramlink> is not prepared.
7146 </error>
7147 </errors>
7148 </function>
7149
7150 <function id="GetClassFields" phase="start" num="53">
7151 <synopsis>Get Class Fields</synopsis>
7152 <description>
7153 For the class indicated by <code>klass</code>, return a count of fields
7154 via <code>field_count_ptr</code> and a list of field IDs via
7155 <code>fields_ptr</code>.
7156 Only directly declared fields are returned (not inherited fields).
7157 Fields are returned in the order they occur in the class file.
7158 An empty field list is returned for array classes and primitive classes
7159 (for example, <code>java.lang.Integer.TYPE</code>).
7160 Use JNI to determine the length of an array.
7161 </description>
7162 <origin>jvmdi</origin>
7163 <capabilities>
7164 </capabilities>
7165 <parameters>
7166 <param id="klass">
7167 <jclass/>
7168 <description>
7169 The class to query.
7170 </description>
7171 </param>
7172 <param id="field_count_ptr">
7173 <outptr><jint/></outptr>
7174 <description>
7175 On return, points to the number of fields declared in this class.
7176 </description>
7177 </param>
7178 <param id="fields_ptr">
7179 <allocbuf outcount="field_count_ptr"><jfieldID/></allocbuf>
7180 <description>
7181 On return, points to the field ID array.
7182 </description>
7183 </param>
7184 </parameters>
7185 <errors>
7186 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
7187 <paramlink id="klass"></paramlink> is not prepared.
7188 </error>
7189 </errors>
7190 </function>
7191
7192 <function id="GetImplementedInterfaces" phase="start" num="54">
7193 <synopsis>Get Implemented Interfaces</synopsis>
7194 <description>
7195 Return the direct super-interfaces of this class. For a class, this
7196 function returns the interfaces declared in its <code>implements</code>
7197 clause. For an interface, this function returns the interfaces declared in
7198 its <code>extends</code> clause.
7199 An empty interface list is returned for array classes and primitive classes
7200 (for example, <code>java.lang.Integer.TYPE</code>).
7201 </description>
7202 <origin>jvmdi</origin>
7203 <capabilities>
7204 </capabilities>
7205 <parameters>
7206 <param id="klass">
7207 <jclass/>
7208 <description>
7209 The class to query.
7210 </description>
7211 </param>
7212 <param id="interface_count_ptr">
7213 <outptr><jint/></outptr>
7214 <description>
7215 On return, points to the number of interfaces.
7216 </description>
7217 </param>
7218 <param id="interfaces_ptr">
7219 <allocbuf outcount="interface_count_ptr"><jclass/></allocbuf>
7220 <description>
7221 On return, points to the interface array.
7222 </description>
7223 </param>
7224 </parameters>
7225 <errors>
7226 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
7227 <paramlink id="klass"></paramlink> is not prepared.
7228 </error>
7229 </errors>
7230 </function>
7231
7232 <function id="GetClassVersionNumbers" phase="start" num="145" since="1.1">
7233 <synopsis>Get Class Version Numbers</synopsis>
7234 <description>
7235 For the class indicated by <code>klass</code>,
7236 return the minor and major version numbers,
7237 as defined in
7238 <vmspec chapter="4"/>.
7239 </description>
7240 <origin>new</origin>
7241 <capabilities>
7242 </capabilities>
7243 <parameters>
7244 <param id="klass">
7245 <jclass/>
7246 <description>
7247 The class to query.
7248 </description>
7249 </param>
7250 <param id="minor_version_ptr">
7251 <outptr><jint/></outptr>
7252 <description>
7253 On return, points to the value of the
7254 <code>minor_version</code> item of the
7255 Class File Format.
7256 Note: to be consistent with the Class File Format,
7257 the minor version number is the first parameter.
7258 </description>
7259 </param>
7260 <param id="major_version_ptr">
7261 <outptr><jint/></outptr>
7262 <description>
7263 On return, points to the value of the
7264 <code>major_version</code> item of the
7265 Class File Format.
7266 </description>
7267 </param>
7268 </parameters>
7269 <errors>
7270 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7271 The class is a primitive or array class.
7272 </error>
7273 </errors>
7274 </function>
7275
7276 <function id="GetConstantPool" phase="start" num="146" since="1.1">
7277 <synopsis>Get Constant Pool</synopsis>
7278 <description>
7279 For the class indicated by <code>klass</code>,
7280 return the raw bytes of the constant pool in the format of the
7281 <code>constant_pool</code> item of
7282 <vmspec chapter="4"/>.
7283 The format of the constant pool may differ between versions
7284 of the Class File Format, so, the
7285 <functionlink id="GetClassVersionNumbers">minor and major
7286 class version numbers</functionlink> should be checked for
7287 compatibility.
7288 <p/>
7289 The returned constant pool might not have the same layout or
7290 contents as the constant pool in the defining class file.
7291 The constant pool returned by GetConstantPool() may have
7292 more or fewer entries than the defining constant pool.
7293 Entries may be in a different order.
7294 The constant pool returned by GetConstantPool() will match the
7295 constant pool used by
7296 <functionlink id="GetBytecodes">GetBytecodes()</functionlink>.
7297 That is, the bytecodes returned by GetBytecodes() will have
7298 constant pool indices which refer to constant pool entries returned
7299 by GetConstantPool().
7300 Note that since <functionlink id="RetransformClasses"/>
7301 and <functionlink id="RedefineClasses"/> can change
7302 the constant pool, the constant pool returned by this function
7303 can change accordingly. Thus, the correspondence between
7304 GetConstantPool() and GetBytecodes() does not hold if there
7305 is an intervening class retransformation or redefinition.
7306 The value of a constant pool entry used by a given bytecode will
7307 match that of the defining class file (even if the indices don't match).
7308 Constant pool entries which are not used directly or indirectly by
7309 bytecodes (for example, UTF-8 strings associated with annotations) are
7310 not required to exist in the returned constant pool.
7311 </description>
7312 <origin>new</origin>
7313 <capabilities>
7314 <required id="can_get_constant_pool"></required>
7315 </capabilities>
7316 <parameters>
7317 <param id="klass">
7318 <jclass/>
7319 <description>
7320 The class to query.
7321 </description>
7322 </param>
7323 <param id="constant_pool_count_ptr">
7324 <outptr><jint/></outptr>
7325 <description>
7326 On return, points to the number of entries
7327 in the constant pool table plus one.
7328 This corresponds to the <code>constant_pool_count</code>
7329 item of the Class File Format.
7330 </description>
7331 </param>
7332 <param id="constant_pool_byte_count_ptr">
7333 <outptr><jint/></outptr>
7334 <description>
7335 On return, points to the number of bytes
7336 in the returned raw constant pool.
7337 </description>
7338 </param>
7339 <param id="constant_pool_bytes_ptr">
7340 <allocbuf outcount="constant_pool_byte_count_ptr"><uchar/></allocbuf>
7341 <description>
7342 On return, points to the raw constant pool, that is the bytes
7343 defined by the <code>constant_pool</code> item of the
7344 Class File Format
7345 </description>
7346 </param>
7347 </parameters>
7348 <errors>
7349 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7350 The class is a primitive or array class.
7351 </error>
7352 </errors>
7353 </function>
7354
7355 <function id="IsInterface" phase="start" num="55">
7356 <synopsis>Is Interface</synopsis>
7357 <description>
7358 Determines whether a class object reference represents an interface.
7359 The <code>jboolean</code> result is
7360 <code>JNI_TRUE</code> if the "class" is actually an interface,
7361 <code>JNI_FALSE</code> otherwise.
7362 </description>
7363 <origin>jvmdi</origin>
7364 <capabilities>
7365 </capabilities>
7366 <parameters>
7367 <param id="klass">
7368 <jclass/>
7369 <description>
7370 The class to query.
7371 </description>
7372 </param>
7373 <param id="is_interface_ptr">
7374 <outptr><jboolean/></outptr>
7375 <description>
7376 On return, points to the boolean result of this function.
7377
7378 </description>
7379 </param>
7380 </parameters>
7381 <errors>
7382 </errors>
7383 </function>
7384
7385 <function id="IsArrayClass" phase="start" num="56">
7386 <synopsis>Is Array Class</synopsis>
7387 <description>
7388 Determines whether a class object reference represents an array.
7389 The <code>jboolean</code> result is
7390 <code>JNI_TRUE</code> if the class is an array,
7391 <code>JNI_FALSE</code> otherwise.
7392 </description>
7393 <origin>jvmdi</origin>
7394 <capabilities>
7395 </capabilities>
7396 <parameters>
7397 <param id="klass">
7398 <jclass/>
7399 <description>
7400 The class to query.
7401 </description>
7402 </param>
7403 <param id="is_array_class_ptr">
7404 <outptr><jboolean/></outptr>
7405 <description>
7406 On return, points to the boolean result of this function.
7407
7408 </description>
7409 </param>
7410 </parameters>
7411 <errors>
7412 </errors>
7413 </function>
7414
7415 <function id="IsModifiableClass" jkernel="yes" phase="start" num="45" since="1.1">
7416 <synopsis>Is Modifiable Class</synopsis>
7417 <description>
7418 Determines whether a class is modifiable.
7419 If a class is modifiable (<paramlink id="is_modifiable_class_ptr"/>
7420 returns <code>JNI_TRUE</code>) the class can be
7421 redefined with <functionlink id="RedefineClasses"/> (assuming
7422 the agent possesses the
7423 <fieldlink id="can_redefine_classes" struct="jvmtiCapabilities"/>
7424 capability) or
7425 retransformed with <functionlink id="RetransformClasses"/> (assuming
7426 the agent possesses the
7427 <fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/>
7428 capability).
7429 If a class is not modifiable (<paramlink id="is_modifiable_class_ptr"/>
7430 returns <code>JNI_FALSE</code>) the class can be neither
7431 redefined nor retransformed.
7432 <p/>
7433 Primitive classes (for example, <code>java.lang.Integer.TYPE</code>),
7434 array classes, and some implementation defined classes are never modifiable.
7435 <p/>
7436 </description>
7437 <origin>new</origin>
7438 <capabilities>
7439 <capability id="can_redefine_any_class">
7440 If possessed then all classes (except primitive, array, and some implementation defined
7441 classes) are modifiable (redefine or retransform).
7442 </capability>
7443 <capability id="can_retransform_any_class">
7444 If possessed then all classes (except primitive, array, and some implementation defined
7445 classes) are modifiable with <functionlink id="RetransformClasses"/>.
7446 </capability>
7447 <capability id="can_redefine_classes">
7448 No effect on the result of the function.
7449 But must additionally be possessed to modify the class with
7450 <functionlink id="RedefineClasses"/>.
7451 </capability>
7452 <capability id="can_retransform_classes">
7453 No effect on the result of the function.
7454 But must additionally be possessed to modify the class with
7455 <functionlink id="RetransformClasses"/>.
7456 </capability>
7457 </capabilities>
7458 <parameters>
7459 <param id="klass">
7460 <jclass/>
7461 <description>
7462 The class to query.
7463 </description>
7464 </param>
7465 <param id="is_modifiable_class_ptr">
7466 <outptr><jboolean/></outptr>
7467 <description>
7468 On return, points to the boolean result of this function.
7469 </description>
7470 </param>
7471 </parameters>
7472 <errors>
7473 </errors>
7474 </function>
7475
7476 <function id="GetClassLoader" phase="start" num="57">
7477 <synopsis>Get Class Loader</synopsis>
7478 <description>
7479 For the class indicated by <code>klass</code>, return via
7480 <code>classloader_ptr</code> a reference to the class loader for the
7481 class.
7482 </description>
7483 <origin>jvmdi</origin>
7484 <capabilities>
7485 </capabilities>
7486 <parameters>
7487 <param id="klass">
7488 <jclass/>
7489 <description>
7490 The class to query.
7491 </description>
7492 </param>
7493 <param id="classloader_ptr">
7494 <outptr><jobject/></outptr>
7495 <description>
7496 On return, points to the class loader that loaded
7497 this class.
7498 If the class was not created by a class loader
7499 or if the class loader is the bootstrap class loader,
7500 points to <code>NULL</code>.
7501 </description>
7502 </param>
7503 </parameters>
7504 <errors>
7505 </errors>
7506
7507 </function>
7508
7509 <function id="GetSourceDebugExtension" phase="start" num="90">
7510 <synopsis>Get Source Debug Extension</synopsis>
7511 <description>
7512 For the class indicated by <code>klass</code>, return the debug
7513 extension via <code>source_debug_extension_ptr</code>.
7514 The returned string
7515 contains exactly the debug extension information present in the
7516 class file of <code>klass</code>.
7517 </description>
7518 <origin>jvmdi</origin>
7519 <capabilities>
7520 <required id="can_get_source_debug_extension"></required>
7521 </capabilities>
7522 <parameters>
7523 <param id="klass">
7524 <jclass/>
7525 <description>
7526 The class to query.
7527 </description>
7528 </param>
7529 <param id="source_debug_extension_ptr">
7530 <allocbuf><char/></allocbuf>
7531 <description>
7532 On return, points to the class's debug extension, encoded as a
7533 <internallink id="mUTF">modified UTF-8</internallink> string.
7534 </description>
7535 </param>
7536 </parameters>
7537 <errors>
7538 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7539 Class information does not include a debug extension.
7540 </error>
7541 </errors>
7542 </function>
7543
7544 <function id="RetransformClasses" jkernel="yes" num="152" since="1.1">
7545 <synopsis>Retransform Classes</synopsis>
7546 <description>
7547 This function facilitates the
7548 <internallink id="bci">bytecode instrumentation</internallink>
7549 of already loaded classes.
7550 To replace the class definition without reference to the existing
7551 bytecodes, as one might do when recompiling from source for
7552 fix-and-continue debugging, <functionlink id="RedefineClasses"/>
7553 function should be used instead.
7554 <p/>
7555 When classes are initially loaded or when they are
7556 <functionlink id="RedefineClasses">redefined</functionlink>,
7557 the initial class file bytes can be transformed with the
7558 <eventlink id="ClassFileLoadHook"/> event.
7559 This function reruns the transformation process
7560 (whether or not a transformation has previously occurred).
7561 This retransformation follows these steps:
7562 <ul>
7563 <li>starting from the initial class file bytes
7564 </li>
7565 <li>for each <fieldlink id="can_retransform_classes"
7566 struct="jvmtiCapabilities">retransformation
7567 incapable</fieldlink>
7568 agent which received a
7569 <code>ClassFileLoadHook</code> event during the previous
7570 load or redefine, the bytes it returned
7571 (via the <code>new_class_data</code> parameter)
7572 are reused as the output of the transformation;
7573 note that this is equivalent to reapplying
7574 the previous transformation, unaltered. except that
7575 the <code>ClassFileLoadHook</code> event
7576 is <b>not</b> sent to these agents
7577 </li>
7578 <li>for each <fieldlink id="can_retransform_classes"
7579 struct="jvmtiCapabilities">retransformation
7580 capable</fieldlink>
7581 agent, the <code>ClassFileLoadHook</code> event is sent,
7582 allowing a new transformation to be applied
7583 </li>
7584 <li>the transformed class file bytes are installed as the new
7585 definition of the class
7586 </li>
7587 </ul>
7588 See the <eventlink id="ClassFileLoadHook"/> event for more details.
7589 <p/>
7590 The initial class file bytes represent the bytes passed to
7591 <code>ClassLoader.defineClass</code>
7592 or <code>RedefineClasses</code> (before any transformations
7593 were applied), however they may not exactly match them.
7594 The constant pool may differ in ways described in
7595 <functionlink id="GetConstantPool"/>.
7596 Constant pool indices in the bytecodes of methods will correspond.
7597 Some attributes may not be present.
7598 Where order is not meaningful, for example the order of methods,
7599 order may not be preserved.
7600 <p/>
7601 Retransformation can cause new versions of methods to be installed.
7602 Old method versions may become
7603 <internallink id="obsoleteMethods">obsolete</internallink>
7604 The new method version will be used on new invokes.
7605 If a method has active stack frames, those active frames continue to
7606 run the bytecodes of the original method version.
7607 <p/>
7608 This function does not cause any initialization except that which
7609 would occur under the customary JVM semantics.
7610 In other words, retransforming a class does not cause its initializers to be
7611 run. The values of static fields will remain as they were
7612 prior to the call.
7613 <p/>
7614 Threads need not be suspended.
7615 <p/>
7616 All breakpoints in the class are cleared.
7617 <p/>
7618 All attributes are updated.
7619 <p/>
7620 Instances of the retransformed class are not affected -- fields retain their
7621 previous values.
7622 <functionlink id="GetTag">Tags</functionlink> on the instances are
7623 also unaffected.
7624 <p/>
7625 In response to this call, no events other than the
7626 <eventlink id="ClassFileLoadHook"/> event
7627 will be sent.
7628 <p/>
7629 The retransformation may change method bodies, the constant pool and attributes.
7630 The retransformation must not add, remove or rename fields or methods, change the
7631 signatures of methods, change modifiers, or change inheritance.
7632 These restrictions may be lifted in future versions.
7633 See the error return description below for information on error codes
7634 returned if an unsupported retransformation is attempted.
7635 The class file bytes are not verified or installed until they have passed
7636 through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the
7637 returned error code reflects the result of the transformations.
7638 If any error code is returned other than <code>JVMTI_ERROR_NONE</code>,
7639 none of the classes to be retransformed will have a new definition installed.
7640 When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>)
7641 all of the classes to be retransformed will have their new definitions installed.
7642 </description>
7643 <origin>new</origin>
7644 <capabilities>
7645 <required id="can_retransform_classes"></required>
7646 <capability id="can_retransform_any_class"></capability>
7647 </capabilities>
7648 <parameters>
7649 <param id="class_count">
7650 <jint min="0"/>
7651 <description>
7652 The number of classes to be retransformed.
7653 </description>
7654 </param>
7655 <param id="classes">
7656 <inbuf incount="class_count"><jclass/></inbuf>
7657 <description>
7658 The array of classes to be retransformed.
7659 </description>
7660 </param>
7661 </parameters>
7662 <errors>
7663 <error id="JVMTI_ERROR_UNMODIFIABLE_CLASS">
7664 One of the <paramlink id="classes"/> cannot be modified.
7665 See <functionlink id="IsModifiableClass"/>.
7666 </error>
7667 <error id="JVMTI_ERROR_INVALID_CLASS">
7668 One of the <paramlink id="classes"/> is not a valid class.
7669 </error>
7670 <error id="JVMTI_ERROR_UNSUPPORTED_VERSION">
7671 A retransformed class file has a version number not supported by this VM.
7672 </error>
7673 <error id="JVMTI_ERROR_INVALID_CLASS_FORMAT">
7674 A retransformed class file is malformed (The VM would return a <code>ClassFormatError</code>).
7675 </error>
7676 <error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION">
7677 The retransformed class file definitions would lead to a circular definition
7678 (the VM would return a <code>ClassCircularityError</code>).
7679 </error>
7680 <error id="JVMTI_ERROR_FAILS_VERIFICATION">
7681 The retransformed class file bytes fail verification.
7682 </error>
7683 <error id="JVMTI_ERROR_NAMES_DONT_MATCH">
7684 The class name defined in a retransformed class file is
7685 different from the name in the old class object.
7686 </error>
7687 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED">
7688 A retransformed class file would require adding a method.
7689 </error>
7690 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED">
7691 A retransformed class file changes a field.
7692 </error>
7693 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED">
7694 A direct superclass is different for a retransformed class file,
7695 or the set of directly implemented
7696 interfaces is different.
7697 </error>
7698 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED">
7699 A retransformed class file does not declare a method
7700 declared in the old class version.
7701 </error>
7702 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED">
7703 A retransformed class file has different class modifiers.
7704 </error>
7705 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED">
7706 A method in the retransformed class file has different modifiers
7707 than its counterpart in the old class version.
7708 </error>
7709 </errors>
7710 </function>
7711
7712 <function id="RedefineClasses" jkernel="yes" num="87">
7713 <synopsis>Redefine Classes</synopsis>
7714 <typedef id="jvmtiClassDefinition" label="Class redefinition description">
7715 <field id="klass">
7716 <jclass/>
7717 <description>
7718 Class object for this class
7719 </description>
7720 </field>
7721 <field id="class_byte_count">
7722 <jint/>
7723 <description>
7724 Number of bytes defining class (below)
7725 </description>
7726 </field>
7727 <field id="class_bytes">
7728 <inbuf incount="class_byte_count"><uchar/></inbuf>
7729 <description>
7730 Bytes defining class (in <vmspec chapter="4"/>)
7731 </description>
7732 </field>
7733 </typedef>
7734 <description>
7735 All classes given are redefined according to the definitions
7736 supplied.
7737 This function is used to replace the definition of a class
7738 with a new definition, as might be needed in fix-and-continue
7739 debugging.
7740 Where the existing class file bytes are to be transformed, for
7741 example in
7742 <internallink id="bci">bytecode instrumentation</internallink>,
7743 <functionlink id="RetransformClasses"/> should be used.
7744 <p/>
7745 Redefinition can cause new versions of methods to be installed.
7746 Old method versions may become
7747 <internallink id="obsoleteMethods">obsolete</internallink>
7748 The new method version will be used on new invokes.
7749 If a method has active stack frames, those active frames continue to
7750 run the bytecodes of the original method version.
7751 If resetting of stack frames is desired, use
7752 <functionlink id="PopFrame"></functionlink>
7753 to pop frames with obsolete method versions.
7754 <p/>
7755 This function does not cause any initialization except that which
7756 would occur under the customary JVM semantics.
7757 In other words, redefining a class does not cause its initializers to be
7758 run. The values of static fields will remain as they were
7759 prior to the call.
7760 <p/>
7761 Threads need not be suspended.
7762 <p/>
7763 All breakpoints in the class are cleared.
7764 <p/>
7765 All attributes are updated.
7766 <p/>
7767 Instances of the redefined class are not affected -- fields retain their
7768 previous values.
7769 <functionlink id="GetTag">Tags</functionlink> on the instances are
7770 also unaffected.
7771 <p/>
7772 In response to this call, the <jvmti/> event
7773 <eventlink id="ClassFileLoadHook">Class File Load Hook</eventlink>
7774 will be sent (if enabled), but no other <jvmti/> events will be sent.
7775 <p/>
7776 The redefinition may change method bodies, the constant pool and attributes.
7777 The redefinition must not add, remove or rename fields or methods, change the
7778 signatures of methods, change modifiers, or change inheritance.
7779 These restrictions may be lifted in future versions.
7780 See the error return description below for information on error codes
7781 returned if an unsupported redefinition is attempted.
7782 The class file bytes are not verified or installed until they have passed
7783 through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the
7784 returned error code reflects the result of the transformations applied
7785 to the bytes passed into <paramlink id="class_definitions"/>.
7786 If any error code is returned other than <code>JVMTI_ERROR_NONE</code>,
7787 none of the classes to be redefined will have a new definition installed.
7788 When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>)
7789 all of the classes to be redefined will have their new definitions installed.
7790 </description>
7791 <origin>jvmdi</origin>
7792 <capabilities>
7793 <required id="can_redefine_classes"></required>
7794 <capability id="can_redefine_any_class"></capability>
7795 </capabilities>
7796 <parameters>
7797 <param id="class_count">
7798 <jint min="0"/>
7799 <description>
7800 The number of classes specified in <code>class_definitions</code>
7801 </description>
7802 </param>
7803 <param id="class_definitions">
7804 <inbuf incount="class_count"><struct>jvmtiClassDefinition</struct></inbuf>
7805 <description>
7806 The array of new class definitions
7807 </description>
7808 </param>
7809 </parameters>
7810 <errors>
7811 <error id="JVMTI_ERROR_NULL_POINTER">
7812 One of <code>class_bytes</code> is <code>NULL</code>.
7813 </error>
7814 <error id="JVMTI_ERROR_UNMODIFIABLE_CLASS">
7815 An element of <code>class_definitions</code> cannot be modified.
7816 See <functionlink id="IsModifiableClass"/>.
7817 </error>
7818 <error id="JVMTI_ERROR_INVALID_CLASS">
7819 An element of <code>class_definitions</code> is not a valid class.
7820 </error>
7821 <error id="JVMTI_ERROR_UNSUPPORTED_VERSION">
7822 A new class file has a version number not supported by this VM.
7823 </error>
7824 <error id="JVMTI_ERROR_INVALID_CLASS_FORMAT">
7825 A new class file is malformed (The VM would return a <code>ClassFormatError</code>).
7826 </error>
7827 <error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION">
7828 The new class file definitions would lead to a circular definition
7829 (the VM would return a <code>ClassCircularityError</code>).
7830 </error>
7831 <error id="JVMTI_ERROR_FAILS_VERIFICATION">
7832 The class bytes fail verification.
7833 </error>
7834 <error id="JVMTI_ERROR_NAMES_DONT_MATCH">
7835 The class name defined in a new class file is
7836 different from the name in the old class object.
7837 </error>
7838 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED">
7839 A new class file would require adding a method.
7840 </error>
7841 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED">
7842 A new class version changes a field.
7843 </error>
7844 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED">
7845 A direct superclass is different for a new class
7846 version, or the set of directly implemented
7847 interfaces is different.
7848 </error>
7849 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED">
7850 A new class version does not declare a method
7851 declared in the old class version.
7852 </error>
7853 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED">
7854 A new class version has different modifiers.
7855 </error>
7856 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED">
7857 A method in the new class version has different modifiers
7858 than its counterpart in the old class version.
7859 </error>
7860 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE">
7861 A module cannot be modified.
7862 See <functionlink id="IsModifiableModule"/>.
7863 </error>
7864 </errors>
7865 </function>
7866
7867 </category>
7868
7869 <category id="object" label="Object">
7870
7871 <function id="GetObjectSize" jkernel="yes" phase="start" num="154">
7872 <synopsis>Get Object Size</synopsis>
7873 <description>
7874 For the object indicated by <code>object</code>,
7875 return via <code>size_ptr</code> the size of the object.
7876 This size is an implementation-specific approximation of
7877 the amount of storage consumed by this object.
7878 It may include some or all of the object's overhead, and thus
7879 is useful for comparison within an implementation but not
7880 between implementations.
7881 The estimate may change during a single invocation of the JVM.
7882 </description>
7883 <origin>new</origin>
7884 <capabilities>
7885 </capabilities>
7886 <parameters>
7887 <param id="object">
7888 <jobject/>
7889 <description>
7890 The object to query.
7891 </description>
7892 </param>
7893 <param id="size_ptr">
7894 <outptr><jlong/></outptr>
7895 <description>
7896 On return, points to the object's size in bytes.
7897 </description>
7898 </param>
7899 </parameters>
7900 <errors>
7901 </errors>
7902 </function>
7903
7904 <function id="GetObjectHashCode" phase="start" num="58">
7905 <synopsis>Get Object Hash Code</synopsis>
7906 <description>
7907 For the object indicated by <code>object</code>,
7908 return via <code>hash_code_ptr</code> a hash code.
7909 This hash code could be used to maintain a hash table of object references,
7910 however, on some implementations this can cause significant performance
7911 impacts--in most cases
7912 <internallink id="Heap">tags</internallink>
7913 will be a more efficient means of associating information with objects.
7914 This function guarantees
7915 the same hash code value for a particular object throughout its life
7916 </description>
7917 <origin>jvmdi</origin>
7918 <capabilities>
7919 </capabilities>
7920 <parameters>
7921 <param id="object">
7922 <jobject/>
7923 <description>
7924 The object to query.
7925 </description>
7926 </param>
7927 <param id="hash_code_ptr">
7928 <outptr><jint/></outptr>
7929 <description>
7930 On return, points to the object's hash code.
7931 </description>
7932 </param>
7933 </parameters>
7934 <errors>
7935 </errors>
7936 </function>
7937
7938 <function id="GetObjectMonitorUsage" num="59">
7939 <synopsis>Get Object Monitor Usage</synopsis>
7940 <typedef id="jvmtiMonitorUsage" label="Object monitor usage information">
7941 <field id="owner">
7942 <jthread/>
7943 <description>
7944 The thread owning this monitor, or <code>NULL</code> if unused
7945 </description>
7946 </field>
7947 <field id="entry_count">
7948 <jint/>
7949 <description>
7950 The number of times the owning thread has entered the monitor
7951 </description>
7952 </field>
7953 <field id="waiter_count">
7954 <jint/>
7955 <description>
7956 The number of threads waiting to own this monitor
7957 </description>
7958 </field>
7959 <field id="waiters">
7960 <allocfieldbuf><jthread/></allocfieldbuf>
7961 <description>
7962 The <code>waiter_count</code> waiting threads
7963 </description>
7964 </field>
7965 <field id="notify_waiter_count">
7966 <jint/>
7967 <description>
7968 The number of threads waiting to be notified by this monitor
7969 </description>
7970 </field>
7971 <field id="notify_waiters">
7972 <allocfieldbuf><jthread/></allocfieldbuf>
7973 <description>
7974 The <code>notify_waiter_count</code> threads waiting to be notified
7975 </description>
7976 </field>
7977 </typedef>
7978 <description>
7979 Get information about the object's monitor.
7980 The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure
7981 are filled in with information about usage of the monitor.
7982 <todo>
7983 Decide and then clarify suspend requirements.
7984 </todo>
7985 </description>
7986 <origin>jvmdi</origin>
7987 <capabilities>
7988 <required id="can_get_monitor_info"></required>
7989 </capabilities>
7990 <parameters>
7991 <param id="object">
7992 <jobject/>
7993 <description>
7994 The object to query.
7995 </description>
7996 </param>
7997 <param id="info_ptr">
7998 <outptr><struct>jvmtiMonitorUsage</struct></outptr>
7999 <description>
8000 On return, filled with monitor information for the
8001 specified object.
8002 </description>
8003 </param>
8004 </parameters>
8005 <errors>
8006 </errors>
8007 </function>
8008
8009 <elide>
8010 <function id="GetObjectMonitors" num="116">
8011 <synopsis>Get Object Monitors</synopsis>
8012 <description>
8013 Return the list of object monitors.
8014 <p/>
8015 Note: details about each monitor can be examined with
8016 <functionlink id="GetObjectMonitorUsage"></functionlink>.
8017 </description>
8018 <origin>new</origin>
8019 <capabilities>
8020 <required id="can_get_monitor_info"></required>
8021 </capabilities>
8022 <parameters>
8023 <param id="monitorCnt">
8024 <outptr><jint/></outptr>
8025 <description>
8026 On return, pointer to the number
8027 of monitors returned in <code>monitors_ptr</code>.
8028 </description>
8029 </param>
8030 <param id="monitors_ptr">
8031 <allocbuf outcount="monitorCnt"><jobject/></allocbuf>
8032 <description>
8033 On return, pointer to the monitor list.
8034 </description>
8035 </param>
8036 </parameters>
8037 <errors>
8038 </errors>
8039 </function>
8040 </elide>
8041
8042 </category>
8043
8044 <category id="fieldCategory" label="Field">
8045
8046 <intro>
8047 </intro>
8048
8049 <function id="GetFieldName" phase="start" num="60">
8050 <synopsis>Get Field Name (and Signature)</synopsis>
8051 <description>
8052 For the field indicated by <paramlink id="klass"/> and <paramlink id="field"/>,
8053 return the field name via <paramlink id="name_ptr"/> and field signature via
8054 <paramlink id="signature_ptr"/>.
8055 <p/>
8056 Field signatures are defined in the
8057 <externallink id="docs/technotes/guides/jni/spec/jniTOC.html">JNI Specification</externallink>
8058 and are referred to as <code>field descriptors</code> in
8059 <vmspec chapter="4.3.2"/>.
8060 </description>
8061 <origin>jvmdiClone</origin>
8062 <capabilities>
8063 </capabilities>
8064 <parameters>
8065 <param id="klass">
8066 <jclass field="field"/>
8067 <description>
8068 The class of the field to query.
8069 </description>
8070 </param>
8071 <param id="field">
8072 <jfieldID class="klass"/>
8073 <description>
8074 The field to query.
8075 </description>
8076 </param>
8077 <param id="name_ptr">
8078 <allocbuf>
8079 <char/>
8080 <nullok>the name is not returned</nullok>
8081 </allocbuf>
8082 <description>
8083 On return, points to the field name, encoded as a
8084 <internallink id="mUTF">modified UTF-8</internallink> string.
8085 </description>
8086 </param>
8087 <param id="signature_ptr">
8088 <allocbuf>
8089 <char/>
8090 <nullok>the signature is not returned</nullok>
8091 </allocbuf>
8092 <description>
8093 On return, points to the field signature, encoded as a
8094 <internallink id="mUTF">modified UTF-8</internallink> string.
8095 </description>
8096 </param>
8097 <param id="generic_ptr">
8098 <allocbuf>
8099 <char/>
8100 <nullok>the generic signature is not returned</nullok>
8101 </allocbuf>
8102 <description>
8103 On return, points to the generic signature of the field, encoded as a
8104 <internallink id="mUTF">modified UTF-8</internallink> string.
8105 If there is no generic signature attribute for the field, then,
8106 on return, points to <code>NULL</code>.
8107 </description>
8108 </param>
8109 </parameters>
8110 <errors>
8111 </errors>
8112 </function>
8113
8114 <function id="GetFieldDeclaringClass" phase="start" num="61">
8115 <synopsis>Get Field Declaring Class</synopsis>
8116 <description>
8117 For the field indicated by <code>klass</code> and <code>field</code>
8118 return the class that defined it via <code>declaring_class_ptr</code>.
8119 The declaring class will either be <code>klass</code>, a superclass, or
8120 an implemented interface.
8121 </description>
8122 <origin>jvmdi</origin>
8123 <capabilities>
8124 </capabilities>
8125 <parameters>
8126 <param id="klass">
8127 <jclass field="field"/>
8128 <description>
8129 The class 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="declaring_class_ptr">
8139 <outptr><jclass/></outptr>
8140 <description>
8141 On return, points to the declaring class
8142 </description>
8143 </param>
8144 </parameters>
8145 <errors>
8146 </errors>
8147 </function>
8148
8149 <function id="GetFieldModifiers" phase="start" num="62">
8150 <synopsis>Get Field Modifiers</synopsis>
8151 <description>
8152 For the field indicated by <code>klass</code> and <code>field</code>
8153 return the access flags via <code>modifiers_ptr</code>.
8154 Access flags are defined in <vmspec chapter="4"/>.
8155 </description>
8156 <origin>jvmdi</origin>
8157 <capabilities>
8158 </capabilities>
8159 <parameters>
8160 <param id="klass">
8161 <jclass field="field"/>
8162 <description>
8163 The class to query.
8164 </description>
8165 </param>
8166 <param id="field">
8167 <jfieldID class="klass"/>
8168 <description>
8169 The field to query.
8170 </description>
8171 </param>
8172 <param id="modifiers_ptr">
8173 <outptr><jint/></outptr>
8174 <description>
8175 On return, points to the access flags.
8176 </description>
8177 </param>
8178 </parameters>
8179 <errors>
8180 </errors>
8181 </function>
8182
8183 <function id="IsFieldSynthetic" phase="start" num="63">
8184 <synopsis>Is Field Synthetic</synopsis>
8185 <description>
8186 For the field indicated by <code>klass</code> and <code>field</code>, return a
8187 value indicating whether the field is synthetic via <code>is_synthetic_ptr</code>.
8188 Synthetic fields are generated by the compiler but not present in the
8189 original source code.
8190 </description>
8191 <origin>jvmdi</origin>
8192 <capabilities>
8193 <required id="can_get_synthetic_attribute"></required>
8194 </capabilities>
8195 <parameters>
8196 <param id="klass">
8197 <jclass field="field"/>
8198 <description>
8199 The class of the field to query.
8200 </description>
8201 </param>
8202 <param id="field">
8203 <jfieldID class="klass"/>
8204 <description>
8205 The field to query.
8206 </description>
8207 </param>
8208 <param id="is_synthetic_ptr">
8209 <outptr><jboolean/></outptr>
8210 <description>
8211 On return, points to the boolean result of this function.
8212 </description>
8213 </param>
8214 </parameters>
8215 <errors>
8216 </errors>
8217 </function>
8218
8219 </category>
8220
8221 <category id="method" label="Method">
8222
8223 <intro>
8224 These functions provide information about a method (represented as a
8225 <typelink id="jmethodID"/>) and set how methods are processed.
8226 </intro>
8227
8228 <intro id="obsoleteMethods" label="Obsolete Methods">
8229 The functions <functionlink id="RetransformClasses"/> and
8230 <functionlink id="RedefineClasses"/> can cause new versions
8231 of methods to be installed.
8232 An original version of a method is considered equivalent
8233 to the new version if:
8234 <ul>
8235 <li>their bytecodes are the same except for indices into the
8236 constant pool and </li>
8237 <li>the referenced constants are equal.</li>
8238 </ul>
8239 An original method version which is not equivalent to the
8240 new method version is called obsolete and is assigned a new method ID;
8241 the original method ID now refers to the new method version.
8242 A method ID can be tested for obsolescence with
8243 <functionlink id="IsMethodObsolete"/>.
8244 </intro>
8245
8246 <function id="GetMethodName" phase="start" num="64">
8247 <synopsis>Get Method Name (and Signature)</synopsis>
8248 <description>
8249 For the method indicated by <code>method</code>,
8250 return the method name via <code>name_ptr</code> and method signature via
8251 <code>signature_ptr</code>.
8252 <p/>
8253 Method signatures are defined in the
8254 <externallink id="docs/technotes/guides/jni/spec/jniTOC.html">JNI Specification</externallink>
8255 and are referred to as <code>method descriptors</code> in
8256 <vmspec chapter="4.3.3"/>.
8257 Note this is different
8258 than method signatures as defined in the <i>Java Language Specification</i>.
8259 </description>
8260 <origin>jvmdiClone</origin>
8261 <capabilities>
8262 </capabilities>
8263 <parameters>
8264 <param id="method">
8265 <jmethodID/>
8266 <description>
8267 The method to query.
8268 </description>
8269 </param>
8270 <param id="name_ptr">
8271 <allocbuf>
8272 <char/>
8273 <nullok>the name is not returned</nullok>
8274 </allocbuf>
8275 <description>
8276 On return, points to the method name, encoded as a
8277 <internallink id="mUTF">modified UTF-8</internallink> string.
8278 </description>
8279 </param>
8280 <param id="signature_ptr">
8281 <allocbuf>
8282 <char/>
8283 <nullok>the signature is not returned</nullok>
8284 </allocbuf>
8285 <description>
8286 On return, points to the method signature, encoded as a
8287 <internallink id="mUTF">modified UTF-8</internallink> string.
8288 </description>
8289 </param>
8290 <param id="generic_ptr">
8291 <allocbuf>
8292 <char/>
8293 <nullok>the generic signature is not returned</nullok>
8294 </allocbuf>
8295 <description>
8296 On return, points to the generic signature of the method, encoded as a
8297 <internallink id="mUTF">modified UTF-8</internallink> string.
8298 If there is no generic signature attribute for the method, then,
8299 on return, points to <code>NULL</code>.
8300 </description>
8301 </param>
8302 </parameters>
8303 <errors>
8304 </errors>
8305 </function>
8306
8307 <function id="GetMethodDeclaringClass" phase="start" num="65">
8308 <synopsis>Get Method Declaring Class</synopsis>
8309 <description>
8310 For the method indicated by <code>method</code>,
8311 return the class that defined it via <code>declaring_class_ptr</code>.
8312 </description>
8313 <origin>jvmdi</origin>
8314 <capabilities>
8315 </capabilities>
8316 <parameters>
8317 <param id="klass">
8318 <jclass method="method"/>
8319 <description>
8320 The class to query.
8321 </description>
8322 </param>
8323 <param id="method">
8324 <jmethodID class="klass"/>
8325 <description>
8326 The method to query.
8327 </description>
8328 </param>
8329 <param id="declaring_class_ptr">
8330 <outptr><jclass/></outptr>
8331 <description>
8332 On return, points to the declaring class
8333 </description>
8334 </param>
8335 </parameters>
8336 <errors>
8337 </errors>
8338 </function>
8339
8340 <function id="GetMethodModifiers" phase="start" num="66">
8341 <synopsis>Get Method Modifiers</synopsis>
8342 <description>
8343 For the method indicated by <code>method</code>,
8344 return the access flags via <code>modifiers_ptr</code>.
8345 Access flags are defined in <vmspec chapter="4"/>.
8346 </description>
8347 <origin>jvmdi</origin>
8348 <capabilities>
8349 </capabilities>
8350 <parameters>
8351 <param id="klass">
8352 <jclass method="method"/>
8353 <description>
8354 The class to query.
8355 </description>
8356 </param>
8357 <param id="method">
8358 <jmethodID class="klass"/>
8359 <description>
8360 The method to query.
8361 </description>
8362 </param>
8363 <param id="modifiers_ptr">
8364 <outptr><jint/></outptr>
8365 <description>
8366 On return, points to the access flags.
8367 </description>
8368 </param>
8369 </parameters>
8370 <errors>
8371 </errors>
8372 </function>
8373
8374 <function id="GetMaxLocals" phase="start" num="68">
8375 <synopsis>Get Max Locals</synopsis>
8376 <description>
8377 For the method indicated by <code>method</code>,
8378 return the number of local variable slots used by the method,
8379 including the local variables used to pass parameters to the
8380 method on its invocation.
8381 <p/>
8382 See <code>max_locals</code> in <vmspec chapter="4.7.3"/>.
8383 </description>
8384 <origin>jvmdi</origin>
8385 <capabilities>
8386 </capabilities>
8387 <parameters>
8388 <param id="klass">
8389 <jclass method="method"/>
8390 <description>
8391 The class to query.
8392 </description>
8393 </param>
8394 <param id="method">
8395 <jmethodID class="klass" native="error"/>
8396 <description>
8397 The method to query.
8398 </description>
8399 </param>
8400 <param id="max_ptr">
8401 <outptr><jint/></outptr>
8402 <description>
8403 On return, points to the maximum number of local slots
8404 </description>
8405 </param>
8406 </parameters>
8407 <errors>
8408 </errors>
8409 </function>
8410
8411 <function id="GetArgumentsSize" phase="start" num="69">
8412 <synopsis>Get Arguments Size</synopsis>
8413 <description>
8414 For the method indicated by <code>method</code>,
8415 return via <code>max_ptr</code> the number of local variable slots used
8416 by the method's arguments.
8417 Note that two-word arguments use two slots.
8418 </description>
8419 <origin>jvmdi</origin>
8420 <capabilities>
8421 </capabilities>
8422 <parameters>
8423 <param id="klass">
8424 <jclass method="method"/>
8425 <description>
8426 The class to query.
8427 </description>
8428 </param>
8429 <param id="method">
8430 <jmethodID class="klass" native="error"/>
8431 <description>
8432 The method to query.
8433 </description>
8434 </param>
8435 <param id="size_ptr">
8436 <outptr><jint/></outptr>
8437 <description>
8438 On return, points to the number of argument slots
8439 </description>
8440 </param>
8441 </parameters>
8442 <errors>
8443 </errors>
8444 </function>
8445
8446 <function id="GetLineNumberTable" phase="start" num="70">
8447 <synopsis>Get Line Number Table</synopsis>
8448 <typedef id="jvmtiLineNumberEntry" label="Line number table entry">
8449 <field id="start_location">
8450 <jlocation/>
8451 <description>
8452 the <datalink id="jlocation"></datalink> where the line begins
8453 </description>
8454 </field>
8455 <field id="line_number">
8456 <jint/>
8457 <description>
8458 the line number
8459 </description>
8460 </field>
8461 </typedef>
8462 <description>
8463 For the method indicated by <code>method</code>,
8464 return a table of source line number entries. The size of the table is
8465 returned via <code>entry_count_ptr</code> and the table itself is
8466 returned via <code>table_ptr</code>.
8467 </description>
8468 <origin>jvmdi</origin>
8469 <capabilities>
8470 <required id="can_get_line_numbers"></required>
8471 </capabilities>
8472 <parameters>
8473 <param id="klass">
8474 <jclass method="method"/>
8475 <description>
8476 The class to query.
8477 </description>
8478 </param>
8479 <param id="method">
8480 <jmethodID class="klass" native="error"/>
8481 <description>
8482 The method to query.
8483 </description>
8484 </param>
8485 <param id="entry_count_ptr">
8486 <outptr><jint/></outptr>
8487 <description>
8488 On return, points to the number of entries in the table
8489 </description>
8490 </param>
8491 <param id="table_ptr">
8492 <allocbuf outcount="entry_count_ptr"><struct>jvmtiLineNumberEntry</struct></allocbuf>
8493 <description>
8494 On return, points to the line number table pointer.
8495 </description>
8496 </param>
8497 </parameters>
8498 <errors>
8499 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8500 Class information does not include line numbers.
8501 </error>
8502 </errors>
8503 </function>
8504
8505 <function id="GetMethodLocation" phase="start" num="71">
8506 <synopsis>Get Method Location</synopsis>
8507 <description>
8508 For the method indicated by <code>method</code>,
8509 return the beginning and ending addresses through
8510 <code>start_location_ptr</code> and <code>end_location_ptr</code>. In a
8511 conventional byte code indexing scheme,
8512 <code>start_location_ptr</code> will always point to zero
8513 and <code>end_location_ptr</code>
8514 will always point to the byte code count minus one.
8515 </description>
8516 <origin>jvmdi</origin>
8517 <capabilities>
8518 </capabilities>
8519 <parameters>
8520 <param id="klass">
8521 <jclass method="method"/>
8522 <description>
8523 The class to query.
8524 </description>
8525 </param>
8526 <param id="method">
8527 <jmethodID class="klass" native="error"/>
8528 <description>
8529 The method to query.
8530 </description>
8531 </param>
8532 <param id="start_location_ptr">
8533 <outptr><jlocation/></outptr>
8534 <description>
8535 On return, points to the first location, or
8536 <code>-1</code> if location information is not available.
8537 If the information is available and
8538 <functionlink id="GetJLocationFormat"></functionlink>
8539 returns <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>
8540 then this will always be zero.
8541 </description>
8542 </param>
8543 <param id="end_location_ptr">
8544 <outptr><jlocation/></outptr>
8545 <description>
8546 On return, points to the last location,
8547 or <code>-1</code> if location information is not available.
8548 </description>
8549 </param>
8550 </parameters>
8551 <errors>
8552 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8553 Class information does not include method sizes.
8554 </error>
8555 </errors>
8556 </function>
8557
8558 <function id="GetLocalVariableTable" num="72">
8559 <synopsis>Get Local Variable Table</synopsis>
8560 <typedef id="jvmtiLocalVariableEntry" label="Local variable table entry">
8561 <field id="start_location">
8562 <jlocation/>
8563 <description>
8564 The code array index where the local variable is first valid
8565 (that is, where it must have a value).
8566 </description>
8567 </field>
8568 <field id="length">
8569 <jint/>
8570 <description>
8571 The length of the valid section for this local variable.
8572 The last code array index where the local variable is valid
8573 is <code>start_location + length</code>.
8574 </description>
8575 </field>
8576 <field id="name">
8577 <allocfieldbuf><char/></allocfieldbuf>
8578 <description>
8579 The local variable name, encoded as a
8580 <internallink id="mUTF">modified UTF-8</internallink> string.
8581 </description>
8582 </field>
8583 <field id="signature">
8584 <allocfieldbuf><char/></allocfieldbuf>
8585 <description>
8586 The local variable's type signature, encoded as a
8587 <internallink id="mUTF">modified UTF-8</internallink> string.
8588 The signature format is the same as that defined in
8589 <vmspec chapter="4.3.2"/>.
8590 </description>
8591 </field>
8592 <field id="generic_signature">
8593 <allocfieldbuf><char/></allocfieldbuf>
8594 <description>
8595 The local variable's generic signature, encoded as a
8596 <internallink id="mUTF">modified UTF-8</internallink> string.
8597 The value of this field will be <code>NULL</code> for any local
8598 variable which does not have a generic type.
8599 </description>
8600 </field>
8601 <field id="slot">
8602 <jint/>
8603 <description>
8604 The local variable's slot. See <internallink id="local">Local Variables</internallink>.
8605 </description>
8606 </field>
8607 </typedef>
8608 <description>
8609 Return local variable information.
8610 </description>
8611 <origin>jvmdiClone</origin>
8612 <capabilities>
8613 <required id="can_access_local_variables"></required>
8614 </capabilities>
8615 <parameters>
8616 <param id="method">
8617 <jmethodID native="error"/>
8618 <description>
8619 The method to query.
8620 </description>
8621 </param>
8622 <param id="entry_count_ptr">
8623 <outptr><jint/></outptr>
8624 <description>
8625 On return, points to the number of entries in the table
8626 </description>
8627 </param>
8628 <param id="table_ptr">
8629 <allocbuf outcount="entry_count_ptr"><struct>jvmtiLocalVariableEntry</struct></allocbuf>
8630 <description>
8631 On return, points to an array of local variable table entries.
8632 </description>
8633 </param>
8634 </parameters>
8635 <errors>
8636 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8637 Class information does not include local variable
8638 information.
8639 </error>
8640 </errors>
8641 </function>
8642
8643 <function id="GetBytecodes" phase="start" num="75">
8644 <synopsis>Get Bytecodes</synopsis>
8645 <description>
8646 For the method indicated by <code>method</code>,
8647 return the byte codes that implement the method. The number of
8648 bytecodes is returned via <code>bytecode_count_ptr</code>. The byte codes
8649 themselves are returned via <code>bytecodes_ptr</code>.
8650 </description>
8651 <origin>jvmdi</origin>
8652 <capabilities>
8653 <required id="can_get_bytecodes"></required>
8654 </capabilities>
8655 <parameters>
8656 <param id="klass">
8657 <jclass method="method"/>
8658 <description>
8659 The class to query.
8660 </description>
8661 </param>
8662 <param id="method">
8663 <jmethodID class="klass" native="error"/>
8664 <description>
8665 The method to query.
8666 </description>
8667 </param>
8668 <param id="bytecode_count_ptr">
8669 <outptr><jint/></outptr>
8670 <description>
8671 On return, points to the length of the byte code array
8672 </description>
8673 </param>
8674 <param id="bytecodes_ptr">
8675 <allocbuf outcount="bytecode_count_ptr"><uchar/></allocbuf>
8676 <description>
8677 On return, points to the pointer to the byte code array
8678 </description>
8679 </param>
8680 </parameters>
8681 <errors>
8682 </errors>
8683 </function>
8684
8685 <function id="IsMethodNative" phase="start" num="76">
8686 <synopsis>Is Method Native</synopsis>
8687 <description>
8688 For the method indicated by <code>method</code>, return a
8689 value indicating whether the method is native via <code>is_native_ptr</code>
8690 </description>
8691 <origin>jvmdi</origin>
8692 <capabilities>
8693 </capabilities>
8694 <parameters>
8695 <param id="klass">
8696 <jclass method="method"/>
8697 <description>
8698 The class to query.
8699 </description>
8700 </param>
8701 <param id="method">
8702 <jmethodID class="klass"/>
8703 <description>
8704 The method to query.
8705 </description>
8706 </param>
8707 <param id="is_native_ptr">
8708 <outptr><jboolean/></outptr>
8709 <description>
8710 On return, points to the boolean result of this function.
8711 </description>
8712 </param>
8713 </parameters>
8714 <errors>
8715 </errors>
8716 </function>
8717
8718 <function id="IsMethodSynthetic" phase="start" num="77">
8719 <synopsis>Is Method Synthetic</synopsis>
8720 <description>
8721 For the method indicated by <code>method</code>, return a
8722 value indicating whether the method is synthetic via <code>is_synthetic_ptr</code>.
8723 Synthetic methods are generated by the compiler but not present in the
8724 original source code.
8725 </description>
8726 <origin>jvmdi</origin>
8727 <capabilities>
8728 <required id="can_get_synthetic_attribute"></required>
8729 </capabilities>
8730 <parameters>
8731 <param id="klass">
8732 <jclass method="method"/>
8733 <description>
8734 The class to query.
8735 </description>
8736 </param>
8737 <param id="method">
8738 <jmethodID class="klass"/>
8739 <description>
8740 The method to query.
8741 </description>
8742 </param>
8743 <param id="is_synthetic_ptr">
8744 <outptr><jboolean/></outptr>
8745 <description>
8746 On return, points to the boolean result of this function.
8747 </description>
8748 </param>
8749 </parameters>
8750 <errors>
8751 </errors>
8752 </function>
8753
8754 <function id="IsMethodObsolete" phase="start" num="91">
8755 <synopsis>Is Method Obsolete</synopsis>
8756 <description>
8757 Determine if a method ID refers to an
8758 <internallink id="obsoleteMethods">obsolete</internallink>
8759 method version.
8760 </description>
8761 <origin>jvmdi</origin>
8762 <capabilities>
8763 </capabilities>
8764 <parameters>
8765 <param id="klass">
8766 <jclass method="method"/>
8767 <description>
8768 The class to query.
8769 </description>
8770 </param>
8771 <param id="method">
8772 <jmethodID class="klass"/>
8773 <description>
8774 The method ID to query.
8775 </description>
8776 </param>
8777 <param id="is_obsolete_ptr">
8778 <outptr><jboolean/></outptr>
8779 <description>
8780 On return, points to the boolean result of this function.
8781 </description>
8782 </param>
8783 </parameters>
8784 <errors>
8785 </errors>
8786 </function>
8787
8788 <function id="SetNativeMethodPrefix" jkernel="yes" phase="any" num="73" since="1.1">
8789 <synopsis>Set Native Method Prefix</synopsis>
8790 <description>
8791 This function modifies the failure handling of
8792 native method resolution by allowing retry
8793 with a prefix applied to the name.
8794 When used with the
8795 <eventlink id="ClassFileLoadHook">ClassFileLoadHook
8796 event</eventlink>, it enables native methods to be
8797 <internallink id="bci">instrumented</internallink>.
8798 <p/>
8799 Since native methods cannot be directly instrumented
8800 (they have no bytecodes), they must be wrapped with
8801 a non-native method which can be instrumented.
8802 For example, if we had:
8803 <example>
8804 native boolean foo(int x);</example>
8805 <p/>
8806 We could transform the class file (with the
8807 ClassFileLoadHook event) so that this becomes:
8808 <example>
8809 boolean foo(int x) {
8810 <i>... record entry to foo ...</i>
8811 return wrapped_foo(x);
8812 }
8813
8814 native boolean wrapped_foo(int x);</example>
8815 <p/>
8816 Where foo becomes a wrapper for the actual native method
8817 with the appended prefix "wrapped_". Note that
8818 "wrapped_" would be a poor choice of prefix since it
8819 might conceivably form the name of an existing method
8820 thus something like "$$$MyAgentWrapped$$$_" would be
8821 better but would make these examples less readable.
8822 <p/>
8823 The wrapper will allow data to be collected on the native
8824 method call, but now the problem becomes linking up the
8825 wrapped method with the native implementation.
8826 That is, the method <code>wrapped_foo</code> needs to be
8827 resolved to the native implementation of <code>foo</code>,
8828 which might be:
8829 <example>
8830 Java_somePackage_someClass_foo(JNIEnv* env, jint x)</example>
8831 <p/>
8832 This function allows the prefix to be specified and the
8833 proper resolution to occur.
8834 Specifically, when the standard resolution fails, the
8835 resolution is retried taking the prefix into consideration.
8836 There are two ways that resolution occurs, explicit
8837 resolution with the JNI function <code>RegisterNatives</code>
8838 and the normal automatic resolution. For
8839 <code>RegisterNatives</code>, the VM will attempt this
8840 association:
8841 <example>
8842 method(foo) -> nativeImplementation(foo)</example>
8843 <p/>
8844 When this fails, the resolution will be retried with
8845 the specified prefix prepended to the method name,
8846 yielding the correct resolution:
8847 <example>
8848 method(wrapped_foo) -> nativeImplementation(foo)</example>
8849 <p/>
8850 For automatic resolution, the VM will attempt:
8851 <example>
8852 method(wrapped_foo) -> nativeImplementation(wrapped_foo)</example>
8853 <p/>
8854 When this fails, the resolution will be retried with
8855 the specified prefix deleted from the implementation name,
8856 yielding the correct resolution:
8857 <example>
8858 method(wrapped_foo) -> nativeImplementation(foo)</example>
8859 <p/>
8860 Note that since the prefix is only used when standard
8861 resolution fails, native methods can be wrapped selectively.
8862 <p/>
8863 Since each <jvmti/> environment is independent and
8864 can do its own transformation of the bytecodes, more
8865 than one layer of wrappers may be applied. Thus each
8866 environment needs its own prefix. Since transformations
8867 are applied in order, the prefixes, if applied, will
8868 be applied in the same order.
8869 The order of transformation application is described in
8870 the <eventlink id="ClassFileLoadHook"/> event.
8871 Thus if three environments applied
8872 wrappers, <code>foo</code> might become
8873 <code>$env3_$env2_$env1_foo</code>. But if, say,
8874 the second environment did not apply a wrapper to
8875 <code>foo</code> it would be just
8876 <code>$env3_$env1_foo</code>. To be able to
8877 efficiently determine the sequence of prefixes,
8878 an intermediate prefix is only applied if its non-native
8879 wrapper exists. Thus, in the last example, even though
8880 <code>$env1_foo</code> is not a native method, the
8881 <code>$env1_</code> prefix is applied since
8882 <code>$env1_foo</code> exists.
8883 <p/>
8884 Since the prefixes are used at resolution time
8885 and since resolution may be arbitrarily delayed, a
8886 native method prefix must remain set as long as there
8887 are corresponding prefixed native methods.
8888 </description>
8889 <origin>new</origin>
8890 <capabilities>
8891 <required id="can_set_native_method_prefix"></required>
8892 </capabilities>
8893 <parameters>
8894 <param id="prefix">
8895 <inbuf>
8896 <char/>
8897 <nullok>
8898 any existing prefix in this environment is cancelled
8899 </nullok>
8900 </inbuf>
8901 <description>
8902 The prefix to apply, encoded as a
8903 <internallink id="mUTF">modified UTF-8</internallink> string.
8904 </description>
8905 </param>
8906 </parameters>
8907 <errors>
8908 </errors>
8909 </function>
8910
8911 <function id="SetNativeMethodPrefixes" jkernel="yes" phase="any" num="74" since="1.1">
8912 <synopsis>Set Native Method Prefixes</synopsis>
8913 <description>
8914 For a normal agent, <functionlink id="SetNativeMethodPrefix"/>
8915 will provide all needed native method prefixing.
8916 For a meta-agent that performs multiple independent class
8917 file transformations (for example as a proxy for another
8918 layer of agents) this function allows each transformation
8919 to have its own prefix.
8920 The prefixes are applied in the order supplied and are
8921 processed in the same manor as described for the
8922 application of prefixes from multiple <jvmti/> environments
8923 in <functionlink id="SetNativeMethodPrefix"/>.
8924 <p/>
8925 Any previous prefixes are replaced. Thus, calling this
8926 function with a <paramlink id="prefix_count"/> of <code>0</code>
8927 disables prefixing in this environment.
8928 <p/>
8929 <functionlink id="SetNativeMethodPrefix"/> and this function
8930 are the two ways to set the prefixes.
8931 Calling <code>SetNativeMethodPrefix</code> with
8932 a prefix is the same as calling this function with
8933 <paramlink id="prefix_count"/> of <code>1</code>.
8934 Calling <code>SetNativeMethodPrefix</code> with
8935 <code>NULL</code> is the same as calling this function with
8936 <paramlink id="prefix_count"/> of <code>0</code>.
8937 </description>
8938 <origin>new</origin>
8939 <capabilities>
8940 <required id="can_set_native_method_prefix"></required>
8941 </capabilities>
8942 <parameters>
8943 <param id="prefix_count">
8944 <jint min="0"/>
8945 <description>
8946 The number of prefixes to apply.
8947 </description>
8948 </param>
8949 <param id="prefixes">
8950 <agentbuf>
8951 <char/>
8952 </agentbuf>
8953 <description>
8954 The prefixes to apply for this environment, each encoded as a
8955 <internallink id="mUTF">modified UTF-8</internallink> string.
8956 </description>
8957 </param>
8958 </parameters>
8959 <errors>
8960 </errors>
8961 </function>
8962
8963 </category>
8964
8965 <category id="RawMonitors" label="Raw Monitor">
8966
8967 <function id="CreateRawMonitor" phase="onload" callbacksafe="safe" num="31">
8968 <synopsis>Create Raw Monitor</synopsis>
8969 <description>
8970 Create a raw monitor.
8971 </description>
8972 <origin>jvmdi</origin>
8973 <capabilities>
8974 </capabilities>
8975 <parameters>
8976 <param id="name">
8977 <inbuf><char/></inbuf>
8978 <description>
8979 A name to identify the monitor, encoded as a
8980 <internallink id="mUTF">modified UTF-8</internallink> string.
8981 </description>
8982 </param>
8983 <param id="monitor_ptr">
8984 <outptr><jrawMonitorID/></outptr>
8985 <description>
8986 On return, points to the created monitor.
8987 </description>
8988 </param>
8989 </parameters>
8990 <errors>
8991 </errors>
8992 </function>
8993
8994 <function id="DestroyRawMonitor" phase="onload" callbacksafe="safe" num="32">
8995 <synopsis>Destroy Raw Monitor</synopsis>
8996 <description>
8997 Destroy the raw monitor.
8998 If the monitor being destroyed has been entered by this thread, it will be
8999 exited before it is destroyed.
9000 If the monitor being destroyed has been entered by another thread,
9001 an error will be returned and the monitor will not be destroyed.
9002 </description>
9003 <origin>jvmdi</origin>
9004 <capabilities>
9005 </capabilities>
9006 <parameters>
9007 <param id="monitor">
9008 <jrawMonitorID/>
9009 <description>
9010 The monitor
9011 </description>
9012 </param>
9013 </parameters>
9014 <errors>
9015 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9016 Not monitor owner
9017 </error>
9018 </errors>
9019 </function>
9020
9021 <function id="RawMonitorEnter" phase="any" callbacksafe="safe" impl="innative notrace" num="33">
9022 <synopsis>Raw Monitor Enter</synopsis>
9023 <description>
9024 Gain exclusive ownership of a raw monitor.
9025 The same thread may enter a monitor more then once.
9026 The thread must
9027 <functionlink id="RawMonitorExit">exit</functionlink>
9028 the monitor the same number of times as it is entered.
9029 If a monitor is entered during <code>OnLoad</code> (before attached threads exist)
9030 and has not exited when attached threads come into existence, the enter
9031 is considered to have occurred on the main thread.
9032 </description>
9033 <origin>jvmdi</origin>
9034 <capabilities>
9035 </capabilities>
9036 <parameters>
9037 <param id="monitor">
9038 <jrawMonitorID/>
9039 <description>
9040 The monitor
9041 </description>
9042 </param>
9043 </parameters>
9044 <errors>
9045 </errors>
9046 </function>
9047
9048 <function id="RawMonitorExit" phase="any" callbacksafe="safe" impl="innative notrace" num="34">
9049 <synopsis>Raw Monitor Exit</synopsis>
9050 <description>
9051 Release exclusive ownership of a raw monitor.
9052 </description>
9053 <origin>jvmdi</origin>
9054 <capabilities>
9055 </capabilities>
9056 <parameters>
9057 <param id="monitor">
9058 <jrawMonitorID/>
9059 <description>
9060 The monitor
9061 </description>
9062 </param>
9063 </parameters>
9064 <errors>
9065 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9066 Not monitor owner
9067 </error>
9068 </errors>
9069 </function>
9070
9071 <function id="RawMonitorWait" phase="any" callbacksafe="safe" impl="innative notrace" num="35">
9072 <synopsis>Raw Monitor Wait</synopsis>
9073 <description>
9074 Wait for notification of the raw monitor.
9075 <p/>
9076 Causes the current thread to wait until either another thread calls
9077 <functionlink id="RawMonitorNotify"/> or
9078 <functionlink id="RawMonitorNotifyAll"/>
9079 for the specified raw monitor, or the specified
9080 <paramlink id="millis">timeout</paramlink>
9081 has elapsed.
9082 </description>
9083 <origin>jvmdi</origin>
9084 <capabilities>
9085 </capabilities>
9086 <parameters>
9087 <param id="monitor">
9088 <jrawMonitorID/>
9089 <description>
9090 The monitor
9091 </description>
9092 </param>
9093 <param id="millis">
9094 <jlong/>
9095 <description>
9096 The timeout, in milliseconds. If the timeout is
9097 zero, then real time is not taken into consideration
9098 and the thread simply waits until notified.
9099 </description>
9100 </param>
9101 </parameters>
9102 <errors>
9103 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9104 Not monitor owner
9105 </error>
9106 <error id="JVMTI_ERROR_INTERRUPT">
9107 Wait was interrupted, try again
9108 </error>
9109 </errors>
9110 </function>
9111
9112 <function id="RawMonitorNotify" phase="any" callbacksafe="safe" impl="notrace" num="36">
9113 <synopsis>Raw Monitor Notify</synopsis>
9114 <description>
9115 Notify a single thread waiting on the raw monitor.
9116 </description>
9117 <origin>jvmdi</origin>
9118 <capabilities>
9119 </capabilities>
9120 <parameters>
9121 <param id="monitor">
9122 <jrawMonitorID/>
9123 <description>
9124 The monitor
9125 </description>
9126 </param>
9127 </parameters>
9128 <errors>
9129 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9130 Not monitor owner
9131 </error>
9132 </errors>
9133 </function>
9134
9135 <function id="RawMonitorNotifyAll" phase="any" callbacksafe="safe" impl="notrace" num="37">
9136 <synopsis>Raw Monitor Notify All</synopsis>
9137 <description>
9138 Notify all threads waiting on the raw monitor.
9139 </description>
9140 <origin>jvmdi</origin>
9141 <capabilities>
9142 </capabilities>
9143 <parameters>
9144 <param id="monitor">
9145 <jrawMonitorID/>
9146 <description>
9147 The monitor
9148 </description>
9149 </param>
9150 </parameters>
9151 <errors>
9152 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
9153 Not monitor owner
9154 </error>
9155 </errors>
9156 </function>
9157
9158 <elide>
9159 <function id="GetRawMonitorUse" num="118">
9160 <synopsis>Get Raw Monitor Use</synopsis>
9161 <description>
9162 The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure
9163 are filled in with information about usage of the raw monitor.
9164 </description>
9165 <origin>new</origin>
9166 <capabilities>
9167 <required id="can_get_raw_monitor_usage"></required>
9168 </capabilities>
9169 <parameters>
9170 <param id="monitor">
9171 <jrawMonitorID/>
9172 <description>
9173 the raw monitor to query.
9174 </description>
9175 </param>
9176 <param id="info_ptr">
9177 <outptr><struct>jvmtiMonitorUsage</struct></outptr>
9178 <description>
9179 On return, filled with monitor information for the
9180 specified raw monitor.
9181 </description>
9182 </param>
9183 </parameters>
9184 <errors>
9185 </errors>
9186 </function>
9187
9188 <function id="GetRawMonitors" num="119">
9189 <synopsis>Get Raw Monitors</synopsis>
9190 <description>
9191 Return the list of raw monitors.
9192 <p/>
9193 Note: details about each monitor can be examined with
9194 <functionlink id="GetRawMonitorUse"></functionlink>.
9195 </description>
9196 <origin>new</origin>
9197 <capabilities>
9198 <required id="can_get_raw_monitor_usage"></required>
9199 </capabilities>
9200 <parameters>
9201 <param id="monitorCnt">
9202 <outptr><jint/></outptr>
9203 <description>
9204 On return, pointer to the number
9205 of monitors returned in <code>monitors_ptr</code>.
9206 </description>
9207 </param>
9208 <param id="monitors_ptr">
9209 <allocbuf outcount="monitorCnt"><jrawMonitorID/></allocbuf>
9210 <description>
9211 On return, pointer to the monitor list.
9212 </description>
9213 </param>
9214 </parameters>
9215 <errors>
9216 </errors>
9217 </function>
9218 </elide>
9219 </category>
9220
9221 <category id="jniIntercept" label="JNI Function Interception">
9222
9223 <intro>
9224 Provides the ability to intercept and resend
9225 Java Native Interface (JNI) function calls
9226 by manipulating the JNI function table.
9227 See <externallink id="docs/technotes/guides/jni/spec/functions.html">JNI
9228 Functions</externallink> in the <i>Java Native Interface Specification</i>.
9229 <p/>
9230 The following example illustrates intercepting the
9231 <code>NewGlobalRef</code> JNI call in order to count reference
9232 creation.
9233 <example>
9234 JNIEnv original_jni_Functions;
9235 JNIEnv redirected_jni_Functions;
9236 int my_global_ref_count = 0;
9237
9238 jobject
9239 MyNewGlobalRef(JNIEnv *jni_env, jobject lobj) {
9240 ++my_global_ref_count;
9241 return originalJNIFunctions->NewGlobalRef(env, lobj);
9242 }
9243
9244 void
9245 myInit() {
9246 jvmtiError err;
9247
9248 err = (*jvmti_env)->GetJNIFunctionTable(jvmti_env, &original_jni_Functions);
9249 if (err != JVMTI_ERROR_NONE) {
9250 die();
9251 }
9252 err = (*jvmti_env)->GetJNIFunctionTable(jvmti_env, &redirected_jni_Functions);
9253 if (err != JVMTI_ERROR_NONE) {
9254 die();
9255 }
9256 redirectedJNIFunctions->NewGlobalRef = MyNewGlobalRef;
9257 err = (*jvmti_env)->SetJNIFunctionTable(jvmti_env, redirected_jni_Functions);
9258 if (err != JVMTI_ERROR_NONE) {
9259 die();
9260 }
9261 }
9262 </example>
9263 Sometime after <code>myInit</code> is called the user's JNI
9264 code is executed which makes the call to create a new global
9265 reference. Instead of going to the normal JNI implementation
9266 the call goes to <code>myNewGlobalRef</code>. Note that a
9267 copy of the original function table is kept so that the normal
9268 JNI function can be called after the data is collected.
9269 Note also that any JNI functions which are not overwritten
9270 will behave normally.
9271 <todo>
9272 check that the example compiles and executes.
9273 </todo>
9274 </intro>
9275
9276 <function id="SetJNIFunctionTable" phase="start" num="120">
9277 <synopsis>Set JNI Function Table</synopsis>
9278 <description>
9279 Set the JNI function table
9280 in all current and future JNI environments.
9281 As a result, all future JNI calls are directed to the specified functions.
9282 Use <functionlink id="GetJNIFunctionTable"></functionlink> to get the
9283 function table to pass to this function.
9284 For this function to take effect the the updated table entries must be
9285 used by the JNI clients.
9286 Since the table is defined <code>const</code> some compilers may optimize
9287 away the access to the table, thus preventing this function from taking
9288 effect.
9289 The table is copied--changes to the local copy of the
9290 table have no effect.
9291 This function affects only the function table, all other aspects of the environment are
9292 unaffected.
9293 See the examples <internallink id="jniIntercept">above</internallink>.
9294 </description>
9295 <origin>new</origin>
9296 <capabilities>
9297 </capabilities>
9298 <parameters>
9299 <param id="function_table">
9300 <inptr>
9301 <struct>jniNativeInterface</struct>
9302 </inptr>
9303 <description>
9304 Points to the new JNI function table.
9305 </description>
9306 </param>
9307 </parameters>
9308 <errors>
9309 </errors>
9310 </function>
9311
9312 <function id="GetJNIFunctionTable" phase="start" num="121">
9313 <synopsis>Get JNI Function Table</synopsis>
9314 <description>
9315 Get the JNI function table.
9316 The JNI function table is copied into allocated memory.
9317 If <functionlink id="SetJNIFunctionTable"></functionlink>
9318 has been called, the modified (not the original) function
9319 table is returned.
9320 Only the function table is copied, no other aspects of the environment
9321 are copied.
9322 See the examples <internallink id="jniIntercept">above</internallink>.
9323 </description>
9324 <origin>new</origin>
9325 <capabilities>
9326 </capabilities>
9327 <parameters>
9328 <param id="function_table">
9329 <allocbuf>
9330 <struct>jniNativeInterface</struct>
9331 </allocbuf>
9332 <description>
9333 On return, <code>*function_table</code>
9334 points a newly allocated copy of the JNI function table.
9335 </description>
9336 </param>
9337 </parameters>
9338 <errors>
9339 </errors>
9340 </function>
9341
9342 </category>
9343
9344 <category id="eventManagement" label="Event Management">
9345
9346 <function id="SetEventCallbacks" jkernel="yes" phase="onload" num="122">
9347 <synopsis>Set Event Callbacks</synopsis>
9348 <description>
9349 Set the functions to be called for each event.
9350 The callbacks are specified by supplying a replacement function table.
9351 The function table is copied--changes to the local copy of the
9352 table have no effect.
9353 This is an atomic action, all callbacks are set at once.
9354 No events are sent before this function is called.
9355 When an entry is <code>NULL</code> or when the event is beyond
9356 <paramlink id="size_of_callbacks"></paramlink> no event is sent.
9357 Details on events are
9358 described <internallink id="EventSection">later</internallink> in this document.
9359 An event must be enabled and have a callback in order to be
9360 sent--the order in which this function and
9361 <functionlink id="SetEventNotificationMode"></functionlink>
9362 are called does not affect the result.
9363 </description>
9364 <origin>new</origin>
9365 <capabilities>
9366 </capabilities>
9367 <parameters>
9368 <param id="callbacks">
9369 <inptr>
9370 <struct>jvmtiEventCallbacks</struct>
9371 <nullok>remove the existing callbacks</nullok>
9372 </inptr>
9373 <description>
9374 The new event callbacks.
9375 </description>
9376 </param>
9377 <param id="size_of_callbacks">
9378 <jint min="0"/>
9379 <description>
9380 <code>sizeof(jvmtiEventCallbacks)</code>--for version
9381 compatibility.
9382 </description>
9383 </param>
9384 </parameters>
9385 <errors>
9386 </errors>
9387 </function>
9388
9389 <function id="SetEventNotificationMode" jkernel="yes" phase="onload" num="2">
9390 <synopsis>Set Event Notification Mode</synopsis>
9391 <description>
9392 Control the generation of events.
9393 <constants id="jvmtiEventMode" label="Event Enable/Disable" kind="enum">
9394 <constant id="JVMTI_ENABLE" num="1">
9395 If <paramlink id="mode"></paramlink> is <code>JVMTI_ENABLE</code>,
9396 the event <paramlink id="event_type"></paramlink> will be enabled
9397 </constant>
9398 <constant id="JVMTI_DISABLE" num="0">
9399 If <paramlink id="mode"></paramlink> is <code>JVMTI_DISABLE</code>,
9400 the event <paramlink id="event_type"></paramlink> will be disabled
9401 </constant>
9402 </constants>
9403 If <code>thread</code> is <code>NULL</code>,
9404 the event is enabled or disabled globally; otherwise, it is
9405 enabled or disabled for a particular thread.
9406 An event is generated for
9407 a particular thread if it is enabled either at the thread or global
9408 levels.
9409 <p/>
9410 See <internallink id="EventIndex">below</internallink> for information on specific events.
9411 <p/>
9412 The following events cannot be controlled at the thread
9413 level through this function.
9414 <ul>
9415 <li><eventlink id="VMInit"></eventlink></li>
9416 <li><eventlink id="VMStart"></eventlink></li>
9417 <li><eventlink id="VMDeath"></eventlink></li>
9418 <li><eventlink id="ThreadStart"></eventlink></li>
9419 <li><eventlink id="CompiledMethodLoad"></eventlink></li>
9420 <li><eventlink id="CompiledMethodUnload"></eventlink></li>
9421 <li><eventlink id="DynamicCodeGenerated"></eventlink></li>
9422 <li><eventlink id="DataDumpRequest"></eventlink></li>
9423 </ul>
9424 <p/>
9425 Initially, no events are enabled at either the thread level
9426 or the global level.
9427 <p/>
9428 Any needed capabilities (see Event Enabling Capabilities below) must be possessed
9429 before calling this function.
9430 <p/>
9431 Details on events are
9432 described <internallink id="EventSection">below</internallink>.
9433 </description>
9434 <origin>jvmdiClone</origin>
9435 <eventcapabilities></eventcapabilities>
9436 <parameters>
9437 <param id="mode">
9438 <enum>jvmtiEventMode</enum>
9439 <description>
9440 <code>JVMTI_ENABLE</code> or <code>JVMTI_DISABLE</code>
9441 </description>
9442 </param>
9443 <param id="event_type">
9444 <enum>jvmtiEvent</enum>
9445 <description>
9446 the event to control
9447 </description>
9448 </param>
9449 <param id="event_thread">
9450 <ptrtype>
9451 <jthread impl="noconvert"/>
9452 <nullok>event is controlled at the global level</nullok>
9453 </ptrtype>
9454 <description>
9455 The thread to control
9456 </description>
9457 </param>
9458 <param id="...">
9459 <varargs/>
9460 <description>
9461 for future expansion
9462 </description>
9463 </param>
9464 </parameters>
9465 <errors>
9466 <error id="JVMTI_ERROR_INVALID_THREAD">
9467 <paramlink id="event_thread"/> is non-<code>NULL</code> and is not a valid thread.
9468 </error>
9469 <error id="JVMTI_ERROR_THREAD_NOT_ALIVE">
9470 <paramlink id="event_thread"/> is non-<code>NULL</code> and is not live (has not been started or is now dead).
9471 </error>
9472 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9473 thread level control was attempted on events which do not
9474 permit thread level control.
9475 </error>
9476 <error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY">
9477 The Required Event Enabling Capability is not possessed.
9478 </error>
9479 </errors>
9480 </function>
9481
9482 <function id="GenerateEvents" num="123">
9483 <synopsis>Generate Events</synopsis>
9484 <description>
9485 Generate events to represent the current state of the VM.
9486 For example, if <paramlink id="event_type"/> is
9487 <code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code>,
9488 a <eventlink id="CompiledMethodLoad"></eventlink> event will be
9489 sent for each currently compiled method.
9490 Methods that were loaded and now have been unloaded are not sent.
9491 The history of what events have previously been sent does not
9492 effect what events are sent by this function--for example,
9493 all currently compiled methods
9494 will be sent each time this function is called.
9495 <p/>
9496 This function is useful when
9497 events may have been missed due to the agent attaching after program
9498 execution begins; this function generates the missed events.
9499 <p/>
9500 Attempts to execute Java programming language code or
9501 JNI functions may be paused until this function returns -
9502 so neither should be called from the thread sending the event.
9503 This function returns only after the missed events have been
9504 sent, processed and have returned.
9505 The event may be sent on a different thread than the thread
9506 on which the event occurred.
9507 The callback for the event must be set with
9508 <functionlink id="SetEventCallbacks"></functionlink>
9509 and the event must be enabled with
9510 <functionlink id="SetEventNotificationMode"></functionlink>
9511 or the events will not occur.
9512 If the VM no longer has the information to generate some or
9513 all of the requested events, the events are simply not sent -
9514 no error is returned.
9515 <p/>
9516 Only the following events are supported:
9517 <ul>
9518 <li><eventlink id="CompiledMethodLoad"></eventlink></li>
9519 <li><eventlink id="DynamicCodeGenerated"></eventlink></li>
9520 </ul>
9521 </description>
9522 <origin>new</origin>
9523 <capabilities>
9524 <capability id="can_generate_compiled_method_load_events"></capability>
9525 </capabilities>
9526 <parameters>
9527 <param id="event_type">
9528 <enum>jvmtiEvent</enum>
9529 <description>
9530 The type of event to generate. Must be one of these:
9531 <ul>
9532 <li><eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink></li>
9533 <li><eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink></li>
9534 </ul>
9535 </description>
9536 </param>
9537 </parameters>
9538 <errors>
9539 <error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY">
9540 <paramlink id="event_type"/> is
9541 <eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink>
9542 and <fieldlink id="can_generate_compiled_method_load_events" struct="jvmtiCapabilities"></fieldlink>
9543 is <code>false</code>.
9544 </error>
9545 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9546 <paramlink id="event_type"/> is other than
9547 <eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink>
9548 or <eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink>.
9549 </error>
9550 </errors>
9551 </function>
9552
9553 </category>
9554
9555 <category id="extension" label="Extension Mechanism">
9556
9557 <intro>
9558 These functions
9559 allow a <jvmti/> implementation to provide functions and events
9560 beyond those defined in this specification.
9561 <p/>
9562 Both extension functions and extension events have parameters
9563 each of which has a 'type' and 'kind' chosen from the following tables:
9564
9565 <constants id="jvmtiParamTypes" label="Extension Function/Event Parameter Types" kind="enum">
9566 <constant id="JVMTI_TYPE_JBYTE" num="101">
9567 Java programming language primitive type - <code>byte</code>.
9568 JNI type <code>jbyte</code>.
9569 </constant>
9570 <constant id="JVMTI_TYPE_JCHAR" num="102">
9571 Java programming language primitive type - <code>char</code>.
9572 JNI type <code>jchar</code>.
9573 </constant>
9574 <constant id="JVMTI_TYPE_JSHORT" num="103">
9575 Java programming language primitive type - <code>short</code>.
9576 JNI type <code>jshort</code>.
9577 </constant>
9578 <constant id="JVMTI_TYPE_JINT" num="104">
9579 Java programming language primitive type - <code>int</code>.
9580 JNI type <datalink id="jint"></datalink>.
9581 </constant>
9582 <constant id="JVMTI_TYPE_JLONG" num="105">
9583 Java programming language primitive type - <code>long</code>.
9584 JNI type <datalink id="jlong"></datalink>.
9585 </constant>
9586 <constant id="JVMTI_TYPE_JFLOAT" num="106">
9587 Java programming language primitive type - <code>float</code>.
9588 JNI type <datalink id="jfloat"></datalink>.
9589 </constant>
9590 <constant id="JVMTI_TYPE_JDOUBLE" num="107">
9591 Java programming language primitive type - <code>double</code>.
9592 JNI type <datalink id="jdouble"></datalink>.
9593 </constant>
9594 <constant id="JVMTI_TYPE_JBOOLEAN" num="108">
9595 Java programming language primitive type - <code>boolean</code>.
9596 JNI type <datalink id="jboolean"></datalink>.
9597 </constant>
9598 <constant id="JVMTI_TYPE_JOBJECT" num="109">
9599 Java programming language object type - <code>java.lang.Object</code>.
9600 JNI type <datalink id="jobject"></datalink>.
9601 Returned values are JNI local references and must be managed.
9602 </constant>
9603 <constant id="JVMTI_TYPE_JTHREAD" num="110">
9604 Java programming language object type - <code>java.lang.Thread</code>.
9605 <jvmti/> type <datalink id="jthread"></datalink>.
9606 Returned values are JNI local references and must be managed.
9607 </constant>
9608 <constant id="JVMTI_TYPE_JCLASS" num="111">
9609 Java programming language object type - <code>java.lang.Class</code>.
9610 JNI type <datalink id="jclass"></datalink>.
9611 Returned values are JNI local references and must be managed.
9612 </constant>
9613 <constant id="JVMTI_TYPE_JVALUE" num="112">
9614 Union of all Java programming language primitive and object types -
9615 JNI type <datalink id="jvalue"></datalink>.
9616 Returned values which represent object types are JNI local references and must be managed.
9617 </constant>
9618 <constant id="JVMTI_TYPE_JFIELDID" num="113">
9619 Java programming language field identifier -
9620 JNI type <datalink id="jfieldID"></datalink>.
9621 </constant>
9622 <constant id="JVMTI_TYPE_JMETHODID" num="114">
9623 Java programming language method identifier -
9624 JNI type <datalink id="jmethodID"></datalink>.
9625 </constant>
9626 <constant id="JVMTI_TYPE_CCHAR" num="115">
9627 C programming language type - <code>char</code>.
9628 </constant>
9629 <constant id="JVMTI_TYPE_CVOID" num="116">
9630 C programming language type - <code>void</code>.
9631 </constant>
9632 <constant id="JVMTI_TYPE_JNIENV" num="117">
9633 JNI environment - <code>JNIEnv</code>.
9634 Should be used with the correct <datalink id="jvmtiParamKind"/> to make it a pointer type.
9635 </constant>
9636 </constants>
9637
9638 <constants id="jvmtiParamKind" label="Extension Function/Event Parameter Kinds" kind="enum">
9639 <constant id="JVMTI_KIND_IN" num="91">
9640 Ingoing argument - <code>foo</code>.
9641 </constant>
9642 <constant id="JVMTI_KIND_IN_PTR" num="92">
9643 Ingoing pointer argument - <code>const foo*</code>.
9644 </constant>
9645 <constant id="JVMTI_KIND_IN_BUF" num="93">
9646 Ingoing array argument - <code>const foo*</code>.
9647 </constant>
9648 <constant id="JVMTI_KIND_ALLOC_BUF" num="94">
9649 Outgoing allocated array argument - <code>foo**</code>.
9650 Free with <code>Deallocate</code>.
9651 </constant>
9652 <constant id="JVMTI_KIND_ALLOC_ALLOC_BUF" num="95">
9653 Outgoing allocated array of allocated arrays argument - <code>foo***</code>.
9654 Free with <code>Deallocate</code>.
9655 </constant>
9656 <constant id="JVMTI_KIND_OUT" num="96">
9657 Outgoing argument - <code>foo*</code>.
9658 </constant>
9659 <constant id="JVMTI_KIND_OUT_BUF" num="97">
9660 Outgoing array argument (pre-allocated by agent) - <code>foo*</code>.
9661 Do not <code>Deallocate</code>.
9662 </constant>
9663 </constants>
9664
9665 </intro>
9666
9667 <typedef id="jvmtiParamInfo" label="Extension Function/Event Parameter Info">
9668 <field id="name">
9669 <allocfieldbuf><char/></allocfieldbuf>
9670 <description>
9671 The parameter name, encoded as a
9672 <internallink id="mUTF">modified UTF-8</internallink> string
9673 </description>
9674 </field>
9675 <field id="kind">
9676 <enum>jvmtiParamKind</enum>
9677 <description>
9678 The kind of the parameter - type modifiers
9679 </description>
9680 </field>
9681 <field id="base_type">
9682 <enum>jvmtiParamTypes</enum>
9683 <description>
9684 The base type of the parameter - modified by <code>kind</code>
9685 </description>
9686 </field>
9687 <field id="null_ok">
9688 <jboolean/>
9689 <description>
9690 Is a <code>NULL</code> argument permitted? Applies only to pointer and object types.
9691 </description>
9692 </field>
9693 </typedef>
9694
9695 <callback id="jvmtiExtensionFunction">
9696 <enum>jvmtiError</enum>
9697 <synopsis>Extension Function</synopsis>
9698 <description>
9699 This is the implementation-specific extension function.
9700 </description>
9701 <parameters>
9702 <param id="jvmti_env">
9703 <outptr>
9704 <struct>jvmtiEnv</struct>
9705 </outptr>
9706 <description>
9707 The <jvmti/> environment is the only fixed parameter for extension functions.
9708 </description>
9709 </param>
9710 <param id="...">
9711 <varargs/>
9712 <description>
9713 The extension function-specific parameters
9714 </description>
9715 </param>
9716 </parameters>
9717 </callback>
9718
9719 <function id="GetExtensionFunctions" phase="onload" num="124">
9720 <synopsis>Get Extension Functions</synopsis>
9721
9722 <typedef id="jvmtiExtensionFunctionInfo" label="Extension Function Info">
9723 <field id="func">
9724 <ptrtype>
9725 <struct>jvmtiExtensionFunction</struct>
9726 </ptrtype>
9727 <description>
9728 The actual function to call
9729 </description>
9730 </field>
9731 <field id="id">
9732 <allocfieldbuf><char/></allocfieldbuf>
9733 <description>
9734 The identifier for the extension function, encoded as a
9735 <internallink id="mUTF">modified UTF-8</internallink> string.
9736 Uses package name conventions.
9737 For example, <code>com.sun.hotspot.bar</code>
9738 </description>
9739 </field>
9740 <field id="short_description">
9741 <allocfieldbuf><char/></allocfieldbuf>
9742 <description>
9743 A one sentence description of the function, encoded as a
9744 <internallink id="mUTF">modified UTF-8</internallink> string.
9745 </description>
9746 </field>
9747 <field id="param_count">
9748 <jint/>
9749 <description>
9750 The number of parameters excluding <code>jvmtiEnv *jvmti_env</code>
9751 </description>
9752 </field>
9753 <field id="params">
9754 <allocfieldbuf outcount="param_count">
9755 <struct>jvmtiParamInfo</struct>
9756 </allocfieldbuf>
9757 <description>
9758 Array of
9759 <fieldlink id="param_count" struct="jvmtiExtensionFunctionInfo"></fieldlink>
9760 parameters (<code>jvmtiEnv *jvmti_env</code> excluded)
9761 </description>
9762 </field>
9763 <field id="error_count">
9764 <jint/>
9765 <description>
9766 The number of possible error returns (excluding universal errors)
9767 </description>
9768 </field>
9769 <field id="errors">
9770 <allocfieldbuf outcount="error_count">
9771 <enum>jvmtiError</enum>
9772 </allocfieldbuf>
9773 <description>
9774 Array of <fieldlink id="error_count" struct="jvmtiExtensionFunctionInfo"></fieldlink>
9775 possible errors
9776 </description>
9777 </field>
9778 </typedef>
9779
9780 <description>
9781 Returns the set of extension functions.
9782 </description>
9783 <origin>new</origin>
9784 <capabilities>
9785 </capabilities>
9786 <parameters>
9787 <param id="extension_count_ptr">
9788 <outptr><jint/></outptr>
9789 <description>
9790 On return, points to the number of extension functions
9791 </description>
9792 </param>
9793 <param id="extensions">
9794 <allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionFunctionInfo</struct></allocbuf>
9795 <description>
9796 Returns an array of extension function info, one per function
9797 </description>
9798 </param>
9799 </parameters>
9800 <errors>
9801 </errors>
9802 </function>
9803
9804 <function id="GetExtensionEvents" phase="onload" num="125">
9805 <synopsis>Get Extension Events</synopsis>
9806
9807 <typedef id="jvmtiExtensionEventInfo" label="Extension Event Info">
9808 <field id="extension_event_index">
9809 <jint/>
9810 <description>
9811 The identifying index of the event
9812 </description>
9813 </field>
9814 <field id="id">
9815 <allocfieldbuf><char/></allocfieldbuf>
9816 <description>
9817 The identifier for the extension event, encoded as a
9818 <internallink id="mUTF">modified UTF-8</internallink> string.
9819 Uses package name conventions.
9820 For example, <code>com.sun.hotspot.bar</code>
9821 </description>
9822 </field>
9823 <field id="short_description">
9824 <allocfieldbuf><char/></allocfieldbuf>
9825 <description>
9826 A one sentence description of the event, encoded as a
9827 <internallink id="mUTF">modified UTF-8</internallink> string.
9828 </description>
9829 </field>
9830 <field id="param_count">
9831 <jint/>
9832 <description>
9833 The number of parameters excluding <code>jvmtiEnv *jvmti_env</code>
9834 </description>
9835 </field>
9836 <field id="params">
9837 <allocfieldbuf outcount="param_count">
9838 <struct>jvmtiParamInfo</struct>
9839 </allocfieldbuf>
9840 <description>
9841 Array of
9842 <fieldlink id="param_count" struct="jvmtiExtensionEventInfo"></fieldlink>
9843 parameters (<code>jvmtiEnv *jvmti_env</code> excluded)
9844 </description>
9845 </field>
9846 </typedef>
9847
9848 <description>
9849 Returns the set of extension events.
9850 </description>
9851 <origin>new</origin>
9852 <capabilities>
9853 </capabilities>
9854 <parameters>
9855 <param id="extension_count_ptr">
9856 <outptr><jint/></outptr>
9857 <description>
9858 On return, points to the number of extension events
9859 </description>
9860 </param>
9861 <param id="extensions">
9862 <allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionEventInfo</struct></allocbuf>
9863 <description>
9864 Returns an array of extension event info, one per event
9865 </description>
9866 </param>
9867 </parameters>
9868 <errors>
9869 </errors>
9870 </function>
9871
9872 <callback id="jvmtiExtensionEvent">
9873 <void/>
9874 <synopsis>Extension Event</synopsis>
9875 <description>
9876 This is the implementation-specific event.
9877 The event handler is set with
9878 <functionlink id="SetExtensionEventCallback"/>.
9879 <p/>
9880 Event handlers for extension events must be declared varargs to match this definition.
9881 Failure to do so could result in calling convention mismatch and undefined behavior
9882 on some platforms.
9883 <p/>
9884 For example, if the <code>jvmtiParamInfo</code>
9885 returned by <functionlink id="GetExtensionEvents"/> indicates that
9886 there is a <code>jint</code> parameter, the event handler should be
9887 declared:
9888 <example>
9889 void JNICALL myHandler(jvmtiEnv* jvmti_env, jint myInt, ...)
9890 </example>
9891 Note the terminal "<code>...</code>" which indicates varargs.
9892 </description>
9893 <parameters>
9894 <param id="jvmti_env">
9895 <outptr>
9896 <struct>jvmtiEnv</struct>
9897 </outptr>
9898 <description>
9899 The <jvmti/> environment is the only fixed parameter for extension events.
9900 </description>
9901 </param>
9902 <param id="...">
9903 <varargs/>
9904 <description>
9905 The extension event-specific parameters
9906 </description>
9907 </param>
9908 </parameters>
9909 </callback>
9910
9911 <function id="SetExtensionEventCallback" phase="onload" num="126">
9912 <synopsis>Set Extension Event Callback</synopsis>
9913
9914 <description>
9915 Sets the callback function for an extension event and
9916 enables the event. Or, if the callback is <code>NULL</code>, disables
9917 the event. Note that unlike standard events, setting
9918 the callback and enabling the event are a single operation.
9919 </description>
9920 <origin>new</origin>
9921 <capabilities>
9922 </capabilities>
9923 <parameters>
9924 <param id="extension_event_index">
9925 <jint/>
9926 <description>
9927 Identifies which callback to set.
9928 This index is the
9929 <fieldlink id="extension_event_index" struct="jvmtiExtensionEventInfo"></fieldlink>
9930 field of
9931 <datalink id="jvmtiExtensionEventInfo"/>.
9932 </description>
9933 </param>
9934 <param id="callback">
9935 <ptrtype>
9936 <struct>jvmtiExtensionEvent</struct>
9937 <nullok>disable the event</nullok>
9938 </ptrtype>
9939 <description>
9940 If <code>callback</code> is non-<code>NULL</code>,
9941 set <code>callback</code> to be the event callback function
9942 and enable the event.
9943 </description>
9944 </param>
9945 </parameters>
9946 <errors>
9947 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9948 <paramlink id="extension_event_index"/> is not an
9949 <fieldlink id="extension_event_index"
9950 struct="jvmtiExtensionEventInfo"/>
9951 returned by
9952 <functionlink id="GetExtensionEvents"/>
9953 </error>
9954 </errors>
9955 </function>
9956
9957 </category>
9958
9959 <category id="capability" label="Capability">
9960
9961 <intro>
9962 The capabilities functions allow you to change the
9963 functionality available to <jvmti/>--that is,
9964 which <jvmti/>
9965 functions can be called, what events can be generated,
9966 and what functionality these events and functions can
9967 provide.
9968 <p/>
9969 The "Capabilities" section of each function and event describe which
9970 capabilities, if any, they are associated with. "Required Functionality"
9971 means it is available for use and no capabilities must be added to use it.
9972 "Optional Functionality" means the agent must possess the capability
9973 before it can be used.
9974 To possess a capability, the agent must
9975 <functionlink id="AddCapabilities">add the capability</functionlink>.
9976 "Optional Features" describe capabilities which,
9977 if added, extend the feature set.
9978 <p/>
9979 The potentially available capabilities of each <jvmti/> implementation are different.
9980 Depending on the implementation, a capability:
9981 <ul>
9982 <li>may never be added</li>
9983 <li>may be added in either the <code>OnLoad</code> or live phase in any environment</li>
9984 <li>may be added only during the <code>OnLoad</code> phase</li>
9985 <li>may be possessed by only one environment at a time</li>
9986 <li>may be possessed by only one environment at a time,
9987 and only during the <code>OnLoad</code> phase</li>
9988 <li>and so on ...</li>
9989 </ul>
9990 Frequently, the addition of a capability may incur a cost in execution speed, start up
9991 time, and/or memory footprint. Note that the overhead of using a capability
9992 is completely different than the overhead of possessing a capability.
9993 Take single stepping as an example. When single stepping is on (that
9994 is, when the event is enabled and thus actively sending events)
9995 the overhead of sending and processing an event
9996 on each instruction is huge in any implementation.
9997 However, the overhead of possessing the capability may be small or large,
9998 depending on the implementation. Also, when and if a capability is potentially
9999 available depends on the implementation. Some examples:
10000 <ul>
10001 <li>One VM might perform all execution by compiling bytecodes into
10002 native code and be unable to generate single step instructions.
10003 In this implementation the capability can not be added.</li>
10004 <li>Another VM may be able to switch execution to a single stepping
10005 interpreter at any time. In this implementation, having the capability has no
10006 overhead and could be added at any time.</li>
10007 <li>Yet another VM might be able to choose a bytecode compiling or single stepping capable interpreted
10008 execution engine at start up, but be unable to switch between them.
10009 In this implementation the capability would need to be added
10010 during the <code>OnLoad</code> phase (before bytecode
10011 execution begins) and would have a large impact on execution speed
10012 even if single stepping was never used.</li>
10013 <li>Still another VM might be able to add an "is single stepping on" check
10014 into compiled bytecodes or a generated interpreter. Again in this implementation
10015 the capability would need to be added during the <code>OnLoad</code> phase but the overhead (a test
10016 and branch on each instruction) would be considerably less.</li>
10017 </ul>
10018 <p/>
10019 Each <jvmti/> <internallink id="environments">environment</internallink>
10020 has its own set of capabilities.
10021 Initially, that set is empty.
10022 Any desired capability must be added.
10023 If possible, capabilities should be added during the <code>OnLoad</code> phase. For most
10024 virtual machines certain capabilities require special set up for
10025 the virtual machine and this set up must happen
10026 during the <code>OnLoad</code> phase, before the virtual machine begins execution.
10027 Once a capability is added, it can
10028 only be removed if explicitly relinquished by the environment.
10029 <p/>
10030 The agent can,
10031 <functionlink id="GetPotentialCapabilities">determine what
10032 capabilities this VM can potentially provide</functionlink>,
10033 <functionlink id="AddCapabilities">add the capabilities
10034 to be used</functionlink>,
10035 <functionlink id="RelinquishCapabilities">release capabilities
10036 which are no longer needed</functionlink>, and
10037 <functionlink id="GetCapabilities">examine the currently available
10038 capabilities</functionlink>.
10039 </intro>
10040
10041 <intro id="capabilityExamples" label="Capability Examples">
10042 For example, a freshly started agent (in the <code>OnLoad</code> function)
10043 wants to enable all possible capabilities.
10044 Note that, in general, this is not advisable as the agent may suffer
10045 a performance penalty for functionality it is not using.
10046 The code might look like this in C:
10047 <example>
10048 jvmtiCapabilities capa;
10049 jvmtiError err;
10050
10051 err = (*jvmti)->GetPotentialCapabilities(jvmti, &capa);
10052 if (err == JVMTI_ERROR_NONE) {
10053 err = (*jvmti)->AddCapabilities(jvmti, &capa);
10054 </example>
10055 For example, if an agent wants to check if it can get
10056 the bytecodes of a method (that is, it wants to check
10057 if it previously added this capability and has not
10058 relinquished it), the code might
10059 look like this in C:
10060 <example>
10061 jvmtiCapabilities capa;
10062 jvmtiError err;
10063
10064 err = (*jvmti)->GetCapabilities(jvmti, &capa);
10065 if (err == JVMTI_ERROR_NONE) {
10066 if (capa.can_get_bytecodes) { ... } }
10067 </example>
10068 </intro>
10069
10070 <capabilitiestypedef id="jvmtiCapabilities" label="The Capabilities Structure">
10071 <description>
10072 The functions in this category use this capabilities structure
10073 which contains boolean flags corresponding to each capability:
10074 </description>
10075 <capabilityfield id="can_tag_objects">
10076 <description>
10077 Can set and get tags, as described in the
10078 <internallink id="Heap">Heap category</internallink>.
10079 </description>
10080 </capabilityfield>
10081 <capabilityfield id="can_generate_field_modification_events">
10082 <description>
10083 Can set watchpoints on field modification -
10084 <functionlink id="SetFieldModificationWatch"></functionlink>
10085 </description>
10086 </capabilityfield>
10087 <capabilityfield id="can_generate_field_access_events">
10088 <description>
10089 Can set watchpoints on field access -
10090 <functionlink id="SetFieldAccessWatch"></functionlink>
10091 </description>
10092 </capabilityfield>
10093 <capabilityfield id="can_get_bytecodes">
10094 <description>
10095 Can get bytecodes of a method <functionlink id="GetBytecodes"></functionlink>
10096 </description>
10097 </capabilityfield>
10098 <capabilityfield id="can_get_synthetic_attribute">
10099 <description>
10100 Can test if a field or method is synthetic -
10101 <functionlink id="IsFieldSynthetic"></functionlink> and
10102 <functionlink id="IsMethodSynthetic"></functionlink>
10103 </description>
10104 </capabilityfield>
10105 <capabilityfield id="can_get_owned_monitor_info">
10106 <description>
10107 Can get information about ownership of monitors -
10108 <functionlink id="GetOwnedMonitorInfo"></functionlink>
10109 </description>
10110 </capabilityfield>
10111 <capabilityfield id="can_get_current_contended_monitor">
10112 <description>
10113 Can <functionlink id="GetCurrentContendedMonitor"></functionlink>
10114 </description>
10115 </capabilityfield>
10116 <capabilityfield id="can_get_monitor_info">
10117 <description>
10118 Can <functionlink id="GetObjectMonitorUsage"></functionlink>
10119 </description>
10120 </capabilityfield>
10121 <capabilityfield id="can_pop_frame">
10122 <description>
10123 Can pop frames off the stack - <functionlink id="PopFrame"></functionlink>
10124 </description>
10125 </capabilityfield>
10126 <capabilityfield id="can_redefine_classes">
10127 <description>
10128 Can redefine classes with <functionlink id="RedefineClasses"/>.
10129 </description>
10130 </capabilityfield>
10131 <capabilityfield id="can_signal_thread">
10132 <description>
10133 Can send stop or interrupt to threads
10134 </description>
10135 </capabilityfield>
10136 <capabilityfield id="can_get_source_file_name">
10137 <description>
10138 Can get the source file name of a class
10139 </description>
10140 </capabilityfield>
10141 <capabilityfield id="can_get_line_numbers">
10142 <description>
10143 Can get the line number table of a method
10144 </description>
10145 </capabilityfield>
10146 <capabilityfield id="can_get_source_debug_extension">
10147 <description>
10148 Can get the source debug extension of a class
10149 </description>
10150 </capabilityfield>
10151 <capabilityfield id="can_access_local_variables">
10152 <description>
10153 Can set and get local variables
10154 </description>
10155 </capabilityfield>
10156 <capabilityfield id="can_maintain_original_method_order">
10157 <description>
10158 Can return methods in the order they occur in the class file
10159 </description>
10160 </capabilityfield>
10161 <capabilityfield id="can_generate_single_step_events">
10162 <description>
10163 Can get <eventlink id="SingleStep">single step</eventlink> events
10164 </description>
10165 </capabilityfield>
10166 <capabilityfield id="can_generate_exception_events">
10167 <description>
10168 Can get <eventlink id="Exception">exception thrown</eventlink> and
10169 <eventlink id="ExceptionCatch">exception catch</eventlink> events
10170 </description>
10171 </capabilityfield>
10172 <capabilityfield id="can_generate_frame_pop_events">
10173 <description>
10174 Can <functionlink id="NotifyFramePop">set</functionlink> and thus get
10175 <eventlink id="FramePop"></eventlink> events
10176 </description>
10177 </capabilityfield>
10178 <capabilityfield id="can_generate_breakpoint_events">
10179 <description>
10180 Can <functionlink id="SetBreakpoint">set</functionlink> and thus get
10181 <eventlink id="Breakpoint"></eventlink> events
10182 </description>
10183 </capabilityfield>
10184 <capabilityfield id="can_suspend">
10185 <description>
10186 Can suspend and resume threads
10187 </description>
10188 </capabilityfield>
10189 <capabilityfield id="can_redefine_any_class">
10190 <description>
10191 Can modify (retransform or redefine) any modifiable class.
10192 See <functionlink id="IsModifiableClass"/>.
10193 </description>
10194 </capabilityfield>
10195 <capabilityfield id="can_get_current_thread_cpu_time">
10196 <description>
10197 Can <functionlink id="GetCurrentThreadCpuTime">get</functionlink>
10198 current thread CPU time
10199 </description>
10200 </capabilityfield>
10201 <capabilityfield id="can_get_thread_cpu_time">
10202 <description>
10203 Can <functionlink id="GetThreadCpuTime">get</functionlink>
10204 thread CPU time
10205 </description>
10206 </capabilityfield>
10207 <capabilityfield id="can_generate_method_entry_events"
10208 disp1="can_generate" disp2="_method_entry_events"
10209 >
10210 <description>
10211 Can generate method entry events on entering a method
10212 </description>
10213 </capabilityfield>
10214 <capabilityfield id="can_generate_method_exit_events"
10215 disp1="can_generate" disp2="_method_exit_events"
10216 >
10217 <description>
10218 Can generate method exit events on leaving a method
10219 </description>
10220 </capabilityfield>
10221 <capabilityfield id="can_generate_all_class_hook_events"
10222 disp1="can_generate" disp2="_all_class_hook_events"
10223 >
10224 <description>
10225 Can generate ClassFileLoadHook events for every loaded class.
10226 </description>
10227 </capabilityfield>
10228 <capabilityfield id="can_generate_compiled_method_load_events"
10229 disp1="can_generate" disp2="_compiled_method_load_events"
10230 >
10231 <description>
10232 Can generate events when a method is compiled or unloaded
10233 </description>
10234 </capabilityfield>
10235 <capabilityfield id="can_generate_monitor_events"
10236 disp1="can_generate" disp2="_monitor_events"
10237 >
10238 <description>
10239 Can generate events on monitor activity
10240 </description>
10241 </capabilityfield>
10242 <capabilityfield id="can_generate_vm_object_alloc_events"
10243 disp1="can_generate" disp2="_vm_object_alloc_events"
10244 >
10245 <description>
10246 Can generate events on VM allocation of an object
10247 </description>
10248 </capabilityfield>
10249 <capabilityfield id="can_generate_native_method_bind_events"
10250 disp1="can_generate" disp2="_native_method_bind_events"
10251 >
10252 <description>
10253 Can generate events when a native method is bound to its
10254 implementation
10255 </description>
10256 </capabilityfield>
10257 <capabilityfield id="can_generate_garbage_collection_events"
10258 disp1="can_generate" disp2="_garbage_collection_events"
10259 >
10260 <description>
10261 Can generate events when garbage collection begins or ends
10262 </description>
10263 </capabilityfield>
10264 <capabilityfield id="can_generate_object_free_events"
10265 disp1="can_generate" disp2="_object_free_events"
10266 >
10267 <description>
10268 Can generate events when the garbage collector frees an object
10269 </description>
10270 </capabilityfield>
10271 <capabilityfield id="can_force_early_return" since="1.1">
10272 <description>
10273 Can return early from a method, as described in the
10274 <internallink id="ForceEarlyReturn">Force Early Return category</internallink>.
10275 </description>
10276 </capabilityfield>
10277 <capabilityfield id="can_get_owned_monitor_stack_depth_info" since="1.1">
10278 <description>
10279 Can get information about owned monitors with stack depth -
10280 <functionlink id="GetOwnedMonitorStackDepthInfo"></functionlink>
10281 </description>
10282 </capabilityfield>
10283 <capabilityfield id="can_get_constant_pool" since="1.1">
10284 <description>
10285 Can get the constant pool of a class -
10286 <functionlink id="GetConstantPool"></functionlink>
10287 </description>
10288 </capabilityfield>
10289 <capabilityfield id="can_set_native_method_prefix" since="1.1">
10290 <description>
10291 Can set prefix to be applied when native method cannot be resolved -
10292 <functionlink id="SetNativeMethodPrefix"/> and
10293 <functionlink id="SetNativeMethodPrefixes"/>
10294 </description>
10295 </capabilityfield>
10296 <capabilityfield id="can_retransform_classes" since="1.1">
10297 <description>
10298 Can retransform classes with <functionlink id="RetransformClasses"/>.
10299 In addition to the restrictions imposed by the specific
10300 implementation on this capability (see the
10301 <internallink id="capability">Capability</internallink> section),
10302 this capability must be set before the
10303 <eventlink id="ClassFileLoadHook"/> event is enabled for the
10304 first time in this environment.
10305 An environment that possesses this capability at the time that
10306 <code>ClassFileLoadHook</code> is enabled for the first time is
10307 said to be <i>retransformation capable</i>.
10308 An environment that does not possess this capability at the time that
10309 <code>ClassFileLoadHook</code> is enabled for the first time is
10310 said to be <i>retransformation incapable</i>.
10311 </description>
10312 </capabilityfield>
10313 <capabilityfield id="can_retransform_any_class" since="1.1">
10314 <description>
10315 <functionlink id="RetransformClasses"/> can be called on any modifiable class.
10316 See <functionlink id="IsModifiableClass"/>.
10317 (<fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/>
10318 must also be set)
10319 </description>
10320 </capabilityfield>
10321 <capabilityfield id="can_generate_resource_exhaustion_heap_events" since="1.1">
10322 <description>
10323 Can generate events when the VM is unable to allocate memory from
10324 the <tm>Java</tm> platform heap.
10325 See <eventlink id="ResourceExhausted"/>.
10326 </description>
10327 </capabilityfield>
10328 <capabilityfield id="can_generate_resource_exhaustion_threads_events" since="1.1">
10329 <description>
10330 Can generate events when the VM is unable to create a thread.
10331 See <eventlink id="ResourceExhausted"/>.
10332 </description>
10333 </capabilityfield>
10334 <capabilityfield id="can_generate_early_vmstart" since="9">
10335 <description>
10336 Can generate the <code>VMStart</code> event early.
10337 See <eventlink id="VMStart"/>.
10338 </description>
10339 </capabilityfield>
10340 <capabilityfield id="can_generate_early_class_hook_events" since="9">
10341 <description>
10342 Can generate the <eventlink id="ClassFileLoadHook"/> events
10343 in the primordial phase. If this capability and
10344 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events">
10345 <code>can_generate_all_class_hook_events</code></internallink>
10346 are enabled then the <eventlink id="ClassFileLoadHook"/> events
10347 can be posted for classes loaded in the primordial phase.
10348 See <eventlink id="ClassFileLoadHook"/>.
10349 </description>
10350 </capabilityfield>
10351 </capabilitiestypedef>
10352
10353 <function id="GetPotentialCapabilities" jkernel="yes" phase="onload" num="140">
10354 <synopsis>Get Potential Capabilities</synopsis>
10355 <description>
10356 Returns via <paramlink id="capabilities_ptr"></paramlink> the <jvmti/>
10357 features that can potentially be possessed by this environment
10358 at this time.
10359 The returned capabilities differ from the complete set of capabilities
10360 implemented by the VM in two cases: another environment possesses
10361 capabilities that can only be possessed by one environment, or the
10362 current <functionlink id="GetPhase">phase</functionlink> is live,
10363 and certain capabilities can only be added during the <code>OnLoad</code> phase.
10364 The <functionlink id="AddCapabilities"></functionlink> function
10365 may be used to set any or all or these capabilities.
10366 Currently possessed capabilities are included.
10367 <p/>
10368 Typically this function is used in the <code>OnLoad</code> function.
10369 Some virtual machines may allow a limited set of capabilities to be
10370 added in the live phase.
10371 In this case, the set of potentially available capabilities
10372 will likely differ from the <code>OnLoad</code> phase set.
10373 <p/>
10374 See the
10375 <internallink id="capabilityExamples">Capability Examples</internallink>.
10376 </description>
10377 <origin>new</origin>
10378 <capabilities>
10379 </capabilities>
10380 <parameters>
10381 <param id="capabilities_ptr">
10382 <outptr><struct>jvmtiCapabilities</struct></outptr>
10383 <description>
10384 On return, points to the <jvmti/> capabilities that may be added.
10385 </description>
10386 </param>
10387 </parameters>
10388 <errors>
10389 </errors>
10390 </function>
10391
10392 <elide>
10393 <function id="EstimateCostOfCapabilities" phase="onload" num="141">
10394 <synopsis>Estimate Cost Of Capabilities</synopsis>
10395 <description>
10396 <issue>There is strong opposition to this function. The concern is
10397 that it would be difficult or impossible to provide meaningful
10398 numbers, as the amount of impact is conditional on many factors
10399 that a single number could not represent. There is doubt that
10400 conditional implementations would be used or are even a good idea.
10401 The thought is that release documentation for the implementation
10402 would be the best means of exposing this information.
10403 Unless new arguments are presented, I intend to remove this
10404 function in the next revision.
10405 </issue>
10406 <p/>
10407 Return via the <paramlink id="time_impact_ptr"></paramlink> and
10408 <paramlink id="space_impact_ptr"></paramlink> an estimate of the impact
10409 of adding the capabilities pointed to by
10410 <paramlink id="capabilities_ptr"></paramlink>.
10411 The returned estimates are in percentage of additional overhead, thus
10412 a time impact of 100 mean the application might run
10413 at half the speed.
10414 The estimates are very rough approximations and are not guaranteed.
10415 Note also, that the estimates are of the impact of having the
10416 capability available--when and if it is used the impact may be
10417 much greater.
10418 Estimates can be for a single capability or for a set of
10419 capabilities. Note that the costs are not necessarily additive,
10420 adding support for one capability might make another available
10421 for free or conversely having two capabilities at once may
10422 have multiplicative impact.
10423 Estimates are relative to the current set of capabilities -
10424 that is, how much more impact given the currently possessed capabilities.
10425 <p/>
10426 Typically this function is used in the OnLoad function,
10427 some virtual machines may allow a limited set of capabilities to be
10428 added in the live phase.
10429 In this case, the set of potentially available capabilities
10430 will likely differ from the OnLoad phase set.
10431 <p/>
10432 See the
10433 <internallink id="capabilityExamples">Capability Examples</internallink>.
10434 </description>
10435 <origin>new</origin>
10436 <capabilities>
10437 </capabilities>
10438 <parameters>
10439 <param id="capabilities_ptr">
10440 <inptr><struct>jvmtiCapabilities</struct></inptr>
10441 <description>
10442 points to the <jvmti/> capabilities to evaluate.
10443 </description>
10444 </param>
10445 <param id="time_impact_ptr">
10446 <outptr><jint/></outptr>
10447 <description>
10448 On return, points to the estimated percentage increase in
10449 run time if this capability was added.
10450 </description>
10451 </param>
10452 <param id="space_impact_ptr">
10453 <outptr><jint/></outptr>
10454 <description>
10455 On return, points to the estimated percentage increase in
10456 memory space used if this capability was added.
10457 </description>
10458 </param>
10459 </parameters>
10460 <errors>
10461 <error id="JVMTI_ERROR_NOT_AVAILABLE">
10462 The desired capabilities are not even potentially available.
10463 </error>
10464 </errors>
10465 </function>
10466 </elide>
10467
10468 <function id="AddCapabilities" jkernel="yes" phase="onload" num="142">
10469 <synopsis>Add Capabilities</synopsis>
10470 <description>
10471 Set new capabilities by adding the capabilities
10472 whose values are set to one (<code>1</code>) in
10473 <code>*</code><paramlink id="capabilities_ptr"></paramlink>.
10474 All previous capabilities are retained.
10475 Typically this function is used in the <code>OnLoad</code> function.
10476 Some virtual machines may allow a limited set of capabilities to be
10477 added in the live phase.
10478 <p/>
10479 See the
10480 <internallink id="capabilityExamples">Capability Examples</internallink>.
10481 </description>
10482 <origin>new</origin>
10483 <capabilities>
10484 </capabilities>
10485 <parameters>
10486 <param id="capabilities_ptr">
10487 <inptr><struct>jvmtiCapabilities</struct></inptr>
10488 <description>
10489 Points to the <jvmti/> capabilities to add.
10490 </description>
10491 </param>
10492 </parameters>
10493 <errors>
10494 <error id="JVMTI_ERROR_NOT_AVAILABLE">
10495 The desired capabilities are not even potentially available.
10496 </error>
10497 </errors>
10498 </function>
10499
10500
10501 <function id="RelinquishCapabilities" phase="onload" num="143">
10502 <synopsis>Relinquish Capabilities</synopsis>
10503 <description>
10504 Relinquish the capabilities
10505 whose values are set to one (<code>1</code>) in
10506 <code>*</code><paramlink id="capabilities_ptr"></paramlink>.
10507 Some implementations may allow only one environment to have a capability
10508 (see the <internallink id="capability">capability introduction</internallink>).
10509 This function releases capabilities
10510 so that they may be used by other agents.
10511 All other capabilities are retained.
10512 The capability will no longer be present in <functionlink id="GetCapabilities"></functionlink>.
10513 Attempting to relinquish a capability that the agent does not possess is not an error.
10514 <issue>
10515 It is possible for the agent to be actively using capabilities
10516 which are being relinquished. For example, a thread is currently
10517 suspended and can_suspend is being relinquished or an event is currently
10518 enabled and can_generate_whatever is being relinquished.
10519 There are three possible ways we could spec this:
10520 <ul>
10521 <li>relinquish automatically releases them</li>
10522 <li>relinquish checks and returns some error code if held</li>
10523 <li>it is the agent's responsibility and it is not checked</li>
10524 </ul>
10525 One of these should be chosen.
10526 </issue>
10527 </description>
10528 <origin>new</origin>
10529 <capabilities>
10530 </capabilities>
10531 <parameters>
10532 <param id="capabilities_ptr">
10533 <inptr><struct>jvmtiCapabilities</struct></inptr>
10534 <description>
10535 Points to the <jvmti/> capabilities to relinquish.
10536 </description>
10537 </param>
10538 </parameters>
10539 <errors>
10540 </errors>
10541 </function>
10542
10543
10544
10545 <function id="GetCapabilities" jkernel="yes" phase="any" num="89">
10546 <synopsis>Get Capabilities</synopsis>
10547 <description>
10548 Returns via <paramlink id="capabilities_ptr"></paramlink> the optional <jvmti/>
10549 features which this environment currently possesses.
10550 Each possessed capability is indicated by a one (<code>1</code>) in the
10551 corresponding field of the <internallink id="jvmtiCapabilities">capabilities
10552 structure</internallink>.
10553 An environment does not possess a capability unless it has been successfully added with
10554 <functionlink id="AddCapabilities"/>.
10555 An environment only loses possession of a capability if it has been relinquished with
10556 <functionlink id="RelinquishCapabilities"/>. Thus, this function returns the net result
10557 of the <code>AddCapabilities</code> and <code>RelinquishCapabilities</code> calls which
10558 have been made.
10559 <p/>
10560 See the
10561 <internallink id="capabilityExamples">Capability Examples</internallink>.
10562 </description>
10563 <origin>jvmdiClone</origin>
10564 <capabilities>
10565 </capabilities>
10566 <parameters>
10567 <param id="capabilities_ptr">
10568 <outptr><struct>jvmtiCapabilities</struct></outptr>
10569 <description>
10570 On return, points to the <jvmti/> capabilities.
10571 </description>
10572 </param>
10573 </parameters>
10574 <errors>
10575 </errors>
10576 </function>
10577
10578 </category>
10579
10580
10581 <category id="timers" label="Timers">
10582
10583 <intro>
10584 These functions provide timing information.
10585 The resolution at which the time is updated is not specified.
10586 They provides nanosecond precision, but not necessarily nanosecond accuracy.
10587 Details about the timers, such as their maximum values, can be accessed with
10588 the timer information functions.
10589 </intro>
10590
10591 <typedef id="jvmtiTimerInfo" label="Timer Info">
10592 <description>
10593 The information function for each timer returns this data structure.
10594 </description>
10595 <field id="max_value">
10596 <jlong/>
10597 <description>
10598 The maximum value the timer can reach.
10599 After this value is reached the timer wraps back to zero.
10600 This is an unsigned value. If tested or printed as a jlong (signed value)
10601 it may appear to be a negative number.
10602 </description>
10603 </field>
10604 <field id="may_skip_forward">
10605 <jboolean/>
10606 <description>
10607 If true, the timer can be externally adjusted and as a result skip forward.
10608 If false, the timer value will never increase faster than real time.
10609 </description>
10610 </field>
10611 <field id="may_skip_backward">
10612 <jboolean/>
10613 <description>
10614 If true, the timer can be externally adjusted and as a result skip backward.
10615 If false, the timer value will be monotonically increasing.
10616 </description>
10617 </field>
10618 <field id="kind">
10619 <enum>jvmtiTimerKind</enum>
10620 <description>
10621 The kind of timer.
10622 On a platform that does not distinguish between user and system time, <datalink
10623 id="JVMTI_TIMER_TOTAL_CPU"><code>JVMTI_TIMER_TOTAL_CPU</code></datalink>
10624 is returned.
10625 </description>
10626 </field>
10627 <field id="reserved1">
10628 <jlong/>
10629 <description>
10630 Reserved for future use.
10631 </description>
10632 </field>
10633 <field id="reserved2">
10634 <jlong/>
10635 <description>
10636 Reserved for future use.
10637 </description>
10638 </field>
10639 </typedef>
10640
10641 <intro>
10642 Where the timer kind is --
10643
10644 <constants id="jvmtiTimerKind" label="Timer Kinds" kind="enum">
10645 <constant id="JVMTI_TIMER_USER_CPU" num="30">
10646 CPU time that a thread is in user mode.
10647 </constant>
10648 <constant id="JVMTI_TIMER_TOTAL_CPU" num="31">
10649 CPU time that a thread is in user or system mode.
10650 </constant>
10651 <constant id="JVMTI_TIMER_ELAPSED" num="32">
10652 Elapsed time.
10653 </constant>
10654 </constants>
10655 </intro>
10656
10657 <function id="GetCurrentThreadCpuTimerInfo" callbacksafe="safe" impl="innative notrace" phase="start" num="134">
10658 <synopsis>Get Current Thread CPU Timer Information</synopsis>
10659 <description>
10660 Get information about the
10661 <functionlink id="GetCurrentThreadCpuTime"/> timer.
10662 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10663 are filled in with details about the timer.
10664 This information is specific to the platform and the implementation of
10665 <functionlink id="GetCurrentThreadCpuTime"/> and thus
10666 does not vary by thread nor does it vary
10667 during a particular invocation of the VM.
10668 <p/>
10669 Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/>
10670 and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values
10671 returned by <code>GetCurrentThreadCpuTimerInfo</code>
10672 and <functionlink id="GetThreadCpuTimerInfo"/>
10673 may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information.
10674 </description>
10675 <origin>new</origin>
10676 <capabilities>
10677 <required id="can_get_current_thread_cpu_time">
10678 Can get current thread CPU time.
10679 </required>
10680 </capabilities>
10681 <parameters>
10682 <param id="info_ptr">
10683 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10684 <description>
10685 On return, filled with information describing the time
10686 returned by <functionlink id="GetCurrentThreadCpuTime"/>.
10687 </description>
10688 </param>
10689 </parameters>
10690 <errors>
10691 </errors>
10692 </function>
10693
10694 <function id="GetCurrentThreadCpuTime" callbacksafe="safe" impl="innative notrace" phase="start" num="135">
10695 <synopsis>Get Current Thread CPU Time</synopsis>
10696 <description>
10697 Return the CPU time utilized by the current thread.
10698 <p/>
10699 Note that the <functionlink id="GetThreadCpuTime"/>
10700 function provides CPU time for any thread, including
10701 the current thread. <code>GetCurrentThreadCpuTime</code>
10702 exists to support platforms which cannot
10703 supply CPU time for threads other than the current
10704 thread or which have more accurate information for
10705 the current thread (see
10706 <functionlink id="GetCurrentThreadCpuTimerInfo"/> vs
10707 <functionlink id="GetThreadCpuTimerInfo"/>).
10708 On many platforms this call will be equivalent to:
10709 <example>
10710 GetThreadCpuTime(env, NULL, nanos_ptr)
10711 </example>
10712 </description>
10713 <origin>new</origin>
10714 <capabilities>
10715 <required id="can_get_current_thread_cpu_time">
10716 Can get current thread CPU time.
10717 <p/>
10718 If this capability is enabled after threads have started,
10719 the implementation may choose any time up
10720 to and including the time that the capability is enabled
10721 as the point where CPU time collection starts.
10722 <p/>
10723 This capability must be potentially available on any
10724 platform where
10725 <internallink id="jvmtiCapabilities.can_get_thread_cpu_time"><code>can_get_thread_cpu_time</code></internallink>
10726 is potentially available.
10727 </required>
10728 </capabilities>
10729 <parameters>
10730 <param id="nanos_ptr">
10731 <outptr><jlong/></outptr>
10732 <description>
10733 On return, points to the CPU time used by this thread
10734 in nanoseconds.
10735 This is an unsigned value. If tested or printed as a jlong (signed value)
10736 it may appear to be a negative number.
10737 </description>
10738 </param>
10739 </parameters>
10740 <errors>
10741 </errors>
10742 </function>
10743
10744 <function id="GetThreadCpuTimerInfo" num="136">
10745 <synopsis>Get Thread CPU Timer Information</synopsis>
10746 <description>
10747 Get information about the
10748 <functionlink id="GetThreadCpuTime"/> timer.
10749 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10750 are filled in with details about the timer.
10751 This information is specific to the platform and the implementation of
10752 <functionlink id="GetThreadCpuTime"/> and thus
10753 does not vary by thread nor does it vary
10754 during a particular invocation of the VM.
10755 <p/>
10756 Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/>
10757 and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values
10758 returned by <functionlink id="GetCurrentThreadCpuTimerInfo"/>
10759 and <code>GetThreadCpuTimerInfo</code>
10760 may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information.
10761 </description>
10762 <origin>new</origin>
10763 <capabilities>
10764 <required id="can_get_thread_cpu_time">
10765 Can get thread CPU time.
10766 </required>
10767 </capabilities>
10768 <parameters>
10769 <param id="info_ptr">
10770 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10771 <description>
10772 On return, filled with information describing the time
10773 returned by <functionlink id="GetThreadCpuTime"/>.
10774 </description>
10775 </param>
10776 </parameters>
10777 <errors>
10778 </errors>
10779 </function>
10780
10781 <function id="GetThreadCpuTime" num="137">
10782 <synopsis>Get Thread CPU Time</synopsis>
10783 <description>
10784 Return the CPU time utilized by the specified thread.
10785 <p/>
10786 Get information about this timer with
10787 <functionlink id="GetThreadCpuTimerInfo"/>.
10788 </description>
10789 <origin>new</origin>
10790 <capabilities>
10791 <required id="can_get_thread_cpu_time">
10792 Can get thread CPU time.
10793 <p/>
10794 If this capability is enabled after threads have started,
10795 the implementation may choose any time up
10796 to and including the time that the capability is enabled
10797 as the point where CPU time collection starts.
10798 </required>
10799 </capabilities>
10800 <parameters>
10801 <param id="thread">
10802 <jthread null="current"/>
10803 <description>
10804 The thread to query.
10805 </description>
10806 </param>
10807 <param id="nanos_ptr">
10808 <outptr><jlong/></outptr>
10809 <description>
10810 On return, points to the CPU time used by the specified thread
10811 in nanoseconds.
10812 This is an unsigned value. If tested or printed as a jlong (signed value)
10813 it may appear to be a negative number.
10814 </description>
10815 </param>
10816 </parameters>
10817 <errors>
10818 </errors>
10819 </function>
10820
10821 <function id="GetTimerInfo" phase="any" callbacksafe="safe" num="138">
10822 <synopsis>Get Timer Information</synopsis>
10823 <description>
10824 Get information about the
10825 <functionlink id="GetTime"/> timer.
10826 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10827 are filled in with details about the timer.
10828 This information will not change during a particular invocation of the VM.
10829 </description>
10830 <origin>new</origin>
10831 <capabilities>
10832 </capabilities>
10833 <parameters>
10834 <param id="info_ptr">
10835 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10836 <description>
10837 On return, filled with information describing the time
10838 returned by <functionlink id="GetTime"/>.
10839 </description>
10840 </param>
10841 </parameters>
10842 <errors>
10843 </errors>
10844 </function>
10845
10846 <function id="GetTime" phase="any" callbacksafe="safe" num="139">
10847 <synopsis>Get Time</synopsis>
10848 <description>
10849 Return the current value of the system timer, in nanoseconds.
10850 <p/>
10851 The value returned represents nanoseconds since some fixed but
10852 arbitrary time (perhaps in the future, so values may be
10853 negative). This function provides nanosecond precision, but not
10854 necessarily nanosecond accuracy. No guarantees are made about
10855 how frequently values change.
10856 <p/>
10857 Get information about this timer with
10858 <functionlink id="GetTimerInfo"/>.
10859 </description>
10860 <origin>new</origin>
10861 <capabilities>
10862 </capabilities>
10863 <parameters>
10864 <param id="nanos_ptr">
10865 <outptr><jlong/></outptr>
10866 <description>
10867 On return, points to the time in nanoseconds.
10868 This is an unsigned value. If tested or printed as a jlong (signed value)
10869 it may appear to be a negative number.
10870 </description>
10871 </param>
10872 </parameters>
10873 <errors>
10874 </errors>
10875 </function>
10876
10877 <function id="GetAvailableProcessors" phase="any" num="144">
10878 <synopsis>Get Available Processors</synopsis>
10879 <description>
10880 Returns the number of processors available to the Java virtual machine.
10881 <p/>
10882 This value may change during a particular invocation of the virtual machine.
10883 Applications that are sensitive to the number of available processors should
10884 therefore occasionally poll this property.
10885 </description>
10886 <origin>new</origin>
10887 <capabilities>
10888 </capabilities>
10889 <parameters>
10890 <param id="processor_count_ptr">
10891 <outptr><jint/></outptr>
10892 <description>
10893 On return, points to the maximum number of processors available to the
10894 virtual machine; never smaller than one.
10895 </description>
10896 </param>
10897 </parameters>
10898 <errors>
10899 </errors>
10900 </function>
10901
10902 </category>
10903
10904
10905 <category id="classLoaderSearch" label="Class Loader Search">
10906
10907 <intro>
10908 These functions allow the agent to add to the locations that a class loader searches for a class.
10909 This is useful for installing instrumentation under the correct class loader.
10910 </intro>
10911
10912 <function id="AddToBootstrapClassLoaderSearch" jkernel="yes" phase="onload" num="149">
10913 <synopsis>Add To Bootstrap Class Loader Search</synopsis>
10914 <description>
10915 This function can be used to cause instrumentation classes to be defined by the
10916 bootstrap class loader. See <vmspec chapter="5.3.1"/>.
10917 After the bootstrap
10918 class loader unsuccessfully searches for a class, the specified platform-dependent
10919 search path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in
10920 the <paramlink id="segment"/>. This function may be called multiple times to add multiple segments,
10921 the segments will be searched in the order that this function was called.
10922 <p/>
10923 In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent
10924 search path segment to be searched after the bootstrap class loader unsuccessfully searches
10925 for a class. The segment is typically a directory or JAR file.
10926 <p/>
10927 In the live phase the <paramlink id="segment"/> may be used to specify any platform-dependent
10928 path to a <externallink id="docs/technotes/guides/jar/jar.html">
10929 JAR file</externallink>. The agent should take care that the JAR file does not
10930 contain any classes or resources other than those to be defined by the bootstrap
10931 class loader for the purposes of instrumentation.
10932 <p/>
10933 <vmspec/> specifies that a subsequent attempt to resolve a symbolic
10934 reference that the Java virtual machine has previously unsuccessfully attempted
10935 to resolve always fails with the same error that was thrown as a result of the
10936 initial resolution attempt. Consequently, if the JAR file contains an entry
10937 that corresponds to a class for which the Java virtual machine has
10938 unsuccessfully attempted to resolve a reference, then subsequent attempts to
10939 resolve that reference will fail with the same error as the initial attempt.
10940 </description>
10941 <origin>new</origin>
10942 <capabilities>
10943 </capabilities>
10944 <parameters>
10945 <param id="segment">
10946 <inbuf><char/></inbuf>
10947 <description>
10948 The platform-dependent search path segment, encoded as a
10949 <internallink id="mUTF">modified UTF-8</internallink> string.
10950 </description>
10951 </param>
10952 </parameters>
10953 <errors>
10954 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
10955 <paramlink id="segment"/> is an invalid path. In the live phase, anything other than an
10956 existing JAR file is an invalid path.
10957 </error>
10958 </errors>
10959 </function>
10960
10961 <function id="AddToSystemClassLoaderSearch" jkernel="yes" phase="onload" num="151" since="1.1">
10962 <synopsis>Add To System Class Loader Search</synopsis>
10963 <description>
10964 This function can be used to cause instrumentation classes to be
10965 defined by the system class loader. See <vmspec chapter="5.3.2"/>.
10966 After the class loader unsuccessfully searches for a class, the specified platform-dependent search
10967 path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in the
10968 <paramlink id="segment"/>. This function may be called multiple times to add multiple segments, the
10969 segments will be searched in the order that this function was called.
10970 <p/>
10971 In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent
10972 search path segment to be searched after the system class loader unsuccessfully searches
10973 for a class. The segment is typically a directory or JAR file.
10974 <p/>
10975 In the live phase the <paramlink id="segment"/> is a platform-dependent path to a
10976 <externallink id="docs/technotes/guides/jar/jar.html">JAR file</externallink> to be
10977 searched after the system class loader unsuccessfully searches for a class. The agent should
10978 take care that the JAR file does not contain any classes or resources other than those to be
10979 defined by the system class loader for the purposes of instrumentation.
10980 <p/>
10981 In the live phase the system class loader supports adding a JAR file to be searched if
10982 the system class loader implements a method name <code>appendToClassPathForInstrumentation</code>
10983 which takes a single parameter of type <code>java.lang.String</code>. The method is not required
10984 to have <code>public</code> access.
10985 <p/>
10986 <vmspec/> specifies that a subsequent attempt to resolve a symbolic
10987 reference that the Java virtual machine has previously unsuccessfully attempted
10988 to resolve always fails with the same error that was thrown as a result of the
10989 initial resolution attempt. Consequently, if the JAR file contains an entry
10990 that corresponds to a class for which the Java virtual machine has
10991 unsuccessfully attempted to resolve a reference, then subsequent attempts to
10992 resolve that reference will fail with the same error as the initial attempt.
10993 </description>
10994 <origin>new</origin>
10995 <capabilities>
10996 </capabilities>
10997 <parameters>
10998 <param id="segment">
10999 <inbuf><char/></inbuf>
11000 <description>
11001 The platform-dependent search path segment, encoded as a
11002 <internallink id="mUTF">modified UTF-8</internallink> string.
11003 </description>
11004 </param>
11005 </parameters>
11006 <errors>
11007 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
11008 <paramlink id="segment"/> is an invalid path. In the live phase, anything other than an
11009 existing JAR file is an invalid path.
11010 </error>
11011 <error id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED">
11012 Operation not supported by the system class loader.
11013 </error>
11014 </errors>
11015 </function>
11016
11017 </category>
11018
11019
11020 <category id="props" label="System Properties">
11021
11022 <intro>
11023 These functions get and set system properties.
11024 </intro>
11025
11026 <function id="GetSystemProperties" phase="onload" num="130">
11027 <synopsis>Get System Properties</synopsis>
11028 <description>
11029 The list of VM system property keys which may be used with
11030 <functionlink id="GetSystemProperty"/> is returned.
11031 It is strongly recommended that virtual machines provide the
11032 following property keys:
11033 <ul>
11034 <li><code>java.vm.vendor</code></li>
11035 <li><code>java.vm.version</code></li>
11036 <li><code>java.vm.name</code></li>
11037 <li><code>java.vm.info</code></li>
11038 <li><code>java.library.path</code></li>
11039 <li><code>java.class.path</code></li>
11040 </ul>
11041 Provides access to system properties defined by and used
11042 by the VM.
11043 Properties set on the command-line are included.
11044 This allows getting and setting of these properties
11045 before the VM even begins executing bytecodes.
11046 Since this is a VM view of system properties, the set of available
11047 properties will usually be different than that
11048 in <code>java.lang.System.getProperties</code>.
11049 JNI method invocation may be used to access
11050 <code>java.lang.System.getProperties</code>.
11051 <p/>
11052 The set of properties may grow during execution.
11053 </description>
11054 <origin>new</origin>
11055 <capabilities>
11056 </capabilities>
11057 <parameters>
11058 <param id="count_ptr">
11059 <outptr><jint/></outptr>
11060 <description>
11061 On return, points to the number of property keys returned.
11062 </description>
11063 </param>
11064 <param id="property_ptr">
11065 <allocallocbuf outcount="count_ptr"><char/></allocallocbuf>
11066 <description>
11067 On return, points to an array of property keys, encoded as
11068 <internallink id="mUTF">modified UTF-8</internallink> strings.
11069 </description>
11070 </param>
11071 </parameters>
11072 <errors>
11073 </errors>
11074 </function>
11075
11076 <function id="GetSystemProperty" phase="onload" num="131">
11077 <synopsis>Get System Property</synopsis>
11078 <description>
11079 Return a VM system property value given the property key.
11080 <p/>
11081 The function <functionlink id="GetSystemProperties"/>
11082 returns the set of property keys which may be used.
11083 The properties which can be retrieved may grow during
11084 execution.
11085 <p/>
11086 Since this is a VM view of system properties, the values
11087 of properties may differ from that returned by
11088 <code>java.lang.System.getProperty(String)</code>.
11089 A typical VM might copy the values of the VM system
11090 properties into the <code>Properties</code> held by
11091 <code>java.lang.System</code> during the initialization
11092 of that class. Thereafter any changes to the VM system
11093 properties (with <functionlink id="SetSystemProperty"/>)
11094 or the <code>java.lang.System</code> system properties
11095 (with <code>java.lang.System.setProperty(String,String)</code>)
11096 would cause the values to diverge.
11097 JNI method invocation may be used to access
11098 <code>java.lang.System.getProperty(String)</code>.
11099 </description>
11100 <origin>new</origin>
11101 <capabilities>
11102 </capabilities>
11103 <parameters>
11104 <param id="property">
11105 <inbuf><char/></inbuf>
11106 <description>
11107 The key of the property to retrieve, encoded as a
11108 <internallink id="mUTF">modified UTF-8</internallink> string.
11109 </description>
11110 </param>
11111 <param id="value_ptr">
11112 <allocbuf><char/></allocbuf>
11113 <description>
11114 On return, points to the property value, encoded as a
11115 <internallink id="mUTF">modified UTF-8</internallink> string.
11116 </description>
11117 </param>
11118 </parameters>
11119 <errors>
11120 <error id="JVMTI_ERROR_NOT_AVAILABLE">
11121 This property is not available.
11122 Use <functionlink id="GetSystemProperties"/> to find available properties.
11123 </error>
11124 </errors>
11125 </function>
11126
11127 <function id="SetSystemProperty" phase="onloadOnly" num="132">
11128 <synopsis>Set System Property</synopsis>
11129 <description>
11130 Set a VM system property value.
11131 <p/>
11132 The function <functionlink id="GetSystemProperties"/>
11133 returns the set of property keys, some of these may be settable.
11134 See <functionlink id="GetSystemProperty"/>.
11135 </description>
11136 <origin>new</origin>
11137 <capabilities>
11138 </capabilities>
11139 <parameters>
11140 <param id="property">
11141 <inbuf><char/></inbuf>
11142 <description>
11143 The key of the property, encoded as a
11144 <internallink id="mUTF">modified UTF-8</internallink> string.
11145 </description>
11146 </param>
11147 <param id="value_ptr">
11148 <inbuf>
11149 <char/>
11150 <nullok>
11151 do not set the value, but return <errorlink id="JVMTI_ERROR_NOT_AVAILABLE"/>
11152 if the property is not writeable
11153 </nullok>
11154 </inbuf>
11155 <description>
11156 The property value to set, encoded as a
11157 <internallink id="mUTF">modified UTF-8</internallink> string.
11158 </description>
11159 </param>
11160 </parameters>
11161 <errors>
11162 <error id="JVMTI_ERROR_NOT_AVAILABLE">
11163 This property is not available or is not writeable.
11164 </error>
11165 </errors>
11166 </function>
11167
11168 </category>
11169
11170 <category id="general" label="General">
11171
11172 <intro>
11173 </intro>
11174
11175 <function id="GetPhase" jkernel="yes" phase="any" num="133">
11176 <synopsis>Get Phase</synopsis>
11177 <description>
11178 Return the current phase of VM execution.
11179 The phases proceed in sequence:
11180 <constants id="jvmtiPhase" label="Phases of execution" kind="enum">
11181 <constant id="JVMTI_PHASE_ONLOAD" num="1">
11182 <code>OnLoad</code> phase: while in the
11183 <internallink id="onload"><code>Agent_OnLoad</code></internallink>
11184 or, for statically linked agents, the <internallink id="onload">
11185 <code>Agent_OnLoad_<agent-lib-name>
11186 </code></internallink> function.
11187 </constant>
11188 <constant id="JVMTI_PHASE_PRIMORDIAL" num="2">
11189 Primordial phase: between return from <code>Agent_OnLoad</code>
11190 or <code>Agent_OnLoad_<agent-lib-name></code> and the
11191 <code>VMStart</code> event.
11192 </constant>
11193 <constant id="JVMTI_PHASE_START" num="6">
11194 Start phase: when the <eventlink id="VMStart"><code>VMStart</code></eventlink> event
11195 is sent and until the <code>VMInit</code> event is sent.
11196 </constant>
11197 <constant id="JVMTI_PHASE_LIVE" num="4">
11198 Live phase: when the <eventlink id="VMInit"><code>VMInit</code></eventlink> event is sent
11199 and until the <eventlink id="VMDeath"></eventlink> event returns.
11200 </constant>
11201 <constant id="JVMTI_PHASE_DEAD" num="8">
11202 Dead phase: after the <eventlink id="VMDeath"></eventlink> event returns or after
11203 start-up failure.
11204 </constant>
11205 </constants>
11206 In the case of start-up failure the VM will proceed directly to the dead
11207 phase skipping intermediate phases and neither a <code>VMInit</code> nor
11208 <code>VMDeath</code> event will be sent.
11209 <p/>
11210 Most <jvmti/> functions operate only in the live phase.
11211 The following functions operate in either the <code>OnLoad</code> or live phases:
11212 <functionphaselist phase="onload"/>
11213 The following functions operate in only the <code>OnLoad</code> phase:
11214 <functionphaselist phase="onloadOnly"/>
11215 The following functions operate in the start or live phases:
11216 <functionphaselist phase="start"/>
11217 The following functions operate in any phase:
11218 <functionphaselist phase="any"/>
11219 JNI functions (except the Invocation API) must only be used in the start or live phases.
11220 <p/>
11221 Most <jvmti/> events are sent only in the live phase.
11222 The following events operate in others phases:
11223 <eventphaselist phase="start"/>
11224 <eventphaselist phase="any"/>
11225 </description>
11226 <origin>new</origin>
11227 <capabilities>
11228 </capabilities>
11229 <parameters>
11230 <param id="phase_ptr">
11231 <outptr><enum>jvmtiPhase</enum></outptr>
11232 <description>
11233 On return, points to the phase.
11234 </description>
11235 </param>
11236 </parameters>
11237 <errors>
11238 </errors>
11239 </function>
11240
11241 <function id="DisposeEnvironment" jkernel="yes" phase="any" num="127">
11242 <synopsis>Dispose Environment</synopsis>
11243 <description>
11244 Shutdown a <jvmti/> connection created with JNI <code>GetEnv</code>
11245 (see <internallink id="environments"><jvmti/> Environments</internallink>).
11246 Dispose of any resources held by the environment.
11247 <issue>
11248 What resources are reclaimed? What is undone?
11249 Breakpoints,watchpoints removed?
11250 </issue>
11251 Threads suspended by this environment are not resumed by this call,
11252 this must be done explicitly by the agent.
11253 Memory allocated by this environment via calls to <jvmti/> functions
11254 is not released, this can be done explicitly by the agent
11255 by calling <functionlink id="Deallocate"/>.
11256 Raw monitors created by this environment are not destroyed,
11257 this can be done explicitly by the agent
11258 by calling <functionlink id="DestroyRawMonitor"/>.
11259 The state of threads waiting on raw monitors created by this environment
11260 are not affected.
11261 <p/>
11262 Any <functionlink id="SetNativeMethodPrefix">native method
11263 prefixes</functionlink> for this environment will be unset;
11264 the agent must remove any prefixed native methods before
11265 dispose is called.
11266 <p/>
11267 Any <internallink id="capability">capabilities</internallink>
11268 held by this environment are relinquished.
11269 <p/>
11270 Events enabled by this environment will no longer be sent, however
11271 event handlers currently running will continue to run. Caution must
11272 be exercised in the design of event handlers whose environment may
11273 be disposed and thus become invalid during their execution.
11274 <p/>
11275 This environment may not be used after this call.
11276 This call returns to the caller.
11277 </description>
11278 <origin>new</origin>
11279 <capabilities>
11280 </capabilities>
11281 <parameters>
11282 </parameters>
11283 <errors>
11284 </errors>
11285 </function>
11286
11287 <function id="SetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="148">
11288 <synopsis>Set Environment Local Storage</synopsis>
11289 <description>
11290 The VM stores a pointer value associated with each environment.
11291 This pointer value is called <i>environment-local storage</i>.
11292 This value is <code>NULL</code> unless set with this function.
11293 Agents can allocate memory in which they store environment specific
11294 information. By setting environment-local storage it can then be
11295 accessed with
11296 <functionlink id="GetEnvironmentLocalStorage"></functionlink>.
11297 <p/>
11298 Called by the agent to set the value of the <jvmti/>
11299 environment-local storage. <jvmti/> supplies to the agent a pointer-size
11300 environment-local storage that can be used to record per-environment
11301 information.
11302 </description>
11303 <origin>new</origin>
11304 <capabilities>
11305 </capabilities>
11306 <parameters>
11307 <param id="data">
11308 <inbuf>
11309 <void/>
11310 <nullok>value is set to <code>NULL</code></nullok>
11311 </inbuf>
11312 <description>
11313 The value to be entered into the environment-local storage.
11314 </description>
11315 </param>
11316 </parameters>
11317 <errors>
11318 </errors>
11319 </function>
11320
11321 <function id="GetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="147">
11322 <synopsis>Get Environment Local Storage</synopsis>
11323 <description>
11324 Called by the agent to get the value of the <jvmti/> environment-local
11325 storage.
11326 </description>
11327 <origin>new</origin>
11328 <capabilities>
11329 </capabilities>
11330 <parameters>
11331 <param id="data_ptr">
11332 <agentbuf><void/></agentbuf>
11333 <description>
11334 Pointer through which the value of the environment local
11335 storage is returned.
11336 If environment-local storage has not been set with
11337 <functionlink id="SetEnvironmentLocalStorage"></functionlink> returned
11338 pointer is <code>NULL</code>.
11339 </description>
11340 </param>
11341 </parameters>
11342 <errors>
11343 </errors>
11344 </function>
11345
11346 <function id="GetVersionNumber" jkernel="yes" phase="any" num="88">
11347 <synopsis>Get Version Number</synopsis>
11348 <description>
11349 Return the <jvmti/> version via <code>version_ptr</code>.
11350 The return value is the version identifier.
11351 The version identifier includes major, minor and micro
11352 version as well as the interface type.
11353 <constants id="jvmtiVersionInterfaceTypes" label="Version Interface Types" kind="bits">
11354 <constant id="JVMTI_VERSION_INTERFACE_JNI" num="0x00000000">
11355 Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for JNI.
11356 </constant>
11357 <constant id="JVMTI_VERSION_INTERFACE_JVMTI" num="0x30000000">
11358 Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for <jvmti/>.
11359 </constant>
11360 </constants>
11361 <constants id="jvmtiVersionMasks" label="Version Masks" kind="bits">
11362 <constant id="JVMTI_VERSION_MASK_INTERFACE_TYPE" num="0x70000000">
11363 Mask to extract interface type.
11364 The value of the version returned by this function masked with
11365 <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> is always
11366 <code>JVMTI_VERSION_INTERFACE_JVMTI</code>
11367 since this is a <jvmti/> function.
11368 </constant>
11369 <constant id="JVMTI_VERSION_MASK_MAJOR" num="0x0FFF0000">
11370 Mask to extract major version number.
11371 </constant>
11372 <constant id="JVMTI_VERSION_MASK_MINOR" num="0x0000FF00">
11373 Mask to extract minor version number.
11374 </constant>
11375 <constant id="JVMTI_VERSION_MASK_MICRO" num="0x000000FF">
11376 Mask to extract micro version number.
11377 </constant>
11378 </constants>
11379 <constants id="jvmtiVersionShifts" label="Version Shifts" kind="bits">
11380 <constant id="JVMTI_VERSION_SHIFT_MAJOR" num="16">
11381 Shift to extract major version number.
11382 </constant>
11383 <constant id="JVMTI_VERSION_SHIFT_MINOR" num="8">
11384 Shift to extract minor version number.
11385 </constant>
11386 <constant id="JVMTI_VERSION_SHIFT_MICRO" num="0">
11387 Shift to extract micro version number.
11388 </constant>
11389 </constants>
11390 </description>
11391 <origin>jvmdi</origin>
11392 <capabilities>
11393 </capabilities>
11394 <parameters>
11395 <param id="version_ptr">
11396 <outptr><jint/></outptr>
11397 <description>
11398 On return, points to the <jvmti/> version.
11399 </description>
11400 </param>
11401 </parameters>
11402 <errors>
11403 </errors>
11404 </function>
11405
11406
11407 <function id="GetErrorName" phase="any" num="128">
11408 <synopsis>Get Error Name</synopsis>
11409 <description>
11410 Return the symbolic name for an
11411 <internallink id="ErrorSection">error code</internallink>.
11412 <p/>
11413 For example
11414 <code>GetErrorName(env, JVMTI_ERROR_NONE, &err_name)</code>
11415 would return in <code>err_name</code> the string
11416 <code>"JVMTI_ERROR_NONE"</code>.
11417 </description>
11418 <origin>new</origin>
11419 <capabilities>
11420 </capabilities>
11421 <parameters>
11422 <param id="error">
11423 <enum>jvmtiError</enum>
11424 <description>
11425 The error code.
11426 </description>
11427 </param>
11428 <param id="name_ptr">
11429 <allocbuf><char/></allocbuf>
11430 <description>
11431 On return, points to the error name.
11432 The name is encoded as a
11433 <internallink id="mUTF">modified UTF-8</internallink> string,
11434 but is restricted to the ASCII subset.
11435 </description>
11436 </param>
11437 </parameters>
11438 <errors>
11439 </errors>
11440 </function>
11441
11442 <function id="SetVerboseFlag" phase="any" num="150">
11443 <synopsis>Set Verbose Flag</synopsis>
11444 <description>
11445 <constants id="jvmtiVerboseFlag" label="Verbose Flag Enumeration" kind="enum">
11446 <constant id="JVMTI_VERBOSE_OTHER" num="0">
11447 Verbose output other than the below.
11448 </constant>
11449 <constant id="JVMTI_VERBOSE_GC" num="1">
11450 Verbose garbage collector output, like that specified with <code>-verbose:gc</code>.
11451 </constant>
11452 <constant id="JVMTI_VERBOSE_CLASS" num="2">
11453 Verbose class loading output, like that specified with <code>-verbose:class</code>.
11454 </constant>
11455 <constant id="JVMTI_VERBOSE_JNI" num="4">
11456 Verbose JNI output, like that specified with <code>-verbose:jni</code>.
11457 </constant>
11458 </constants>
11459 Control verbose output.
11460 This is the output which typically is sent to <code>stderr</code>.
11461 </description>
11462 <origin>new</origin>
11463 <capabilities>
11464 </capabilities>
11465 <parameters>
11466 <param id="flag">
11467 <enum>jvmtiVerboseFlag</enum>
11468 <description>
11469 Which verbose flag to set.
11470 </description>
11471 </param>
11472 <param id="value">
11473 <jboolean/>
11474 <description>
11475 New value of the flag.
11476 </description>
11477 </param>
11478 </parameters>
11479 <errors>
11480 </errors>
11481 </function>
11482
11483
11484 <function id="GetJLocationFormat" phase="any" num="129">
11485 <synopsis>Get JLocation Format</synopsis>
11486 <description>
11487 Although the greatest functionality is achieved with location information
11488 referencing the virtual machine bytecode index, the definition of
11489 <code>jlocation</code> has intentionally been left unconstrained to allow VM
11490 implementations that do not have this information.
11491 <p/>
11492 This function describes the representation of <code>jlocation</code> used in this VM.
11493 If the returned format is <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>,
11494 <code>jlocation</code>s can
11495 be used as in indices into the array returned by
11496 <functionlink id="GetBytecodes"></functionlink>.
11497 <constants id="jvmtiJlocationFormat" label="JLocation Format Enumeration" kind="enum">
11498 <constant id="JVMTI_JLOCATION_JVMBCI" num="1">
11499 <code>jlocation</code> values represent virtual machine
11500 bytecode indices--that is, offsets into the
11501 virtual machine code for a method.
11502 </constant>
11503 <constant id="JVMTI_JLOCATION_MACHINEPC" num="2">
11504 <code>jlocation</code> values represent native machine
11505 program counter values.
11506 </constant>
11507 <constant id="JVMTI_JLOCATION_OTHER" num="0">
11508 <code>jlocation</code> values have some other representation.
11509 </constant>
11510 </constants>
11511 </description>
11512 <origin>new</origin>
11513 <capabilities>
11514 </capabilities>
11515 <parameters>
11516 <param id="format_ptr">
11517 <outptr><enum>jvmtiJlocationFormat</enum></outptr>
11518 <description>
11519 On return, points to the format identifier for <code>jlocation</code> values.
11520 </description>
11521 </param>
11522 </parameters>
11523 <errors>
11524 </errors>
11525 </function>
11526
11527 </category>
11528
11529 </functionsection>
11530
11531 <errorsection label="Error Reference">
11532 <intro>
11533 Every <jvmti/> function returns a <b><code>jvmtiError</code></b> error code.
11534 <p/>
11535 It is the responsibility of the agent to call <jvmti/> functions with
11536 valid parameters and in the proper context (calling thread is attached,
11537 phase is correct, etc.).
11538 Detecting some error conditions may be difficult, inefficient, or
11539 impossible for an implementation.
11540 The errors listed in
11541 <internallink id="reqerrors">Function Specific Required Errors</internallink>
11542 must be detected by the implementation.
11543 All other errors represent the recommended response to the error
11544 condition.
11545 </intro>
11546
11547 <errorcategory id="universal-error" label="Universal Errors">
11548 <intro>
11549 The following errors may be returned by any function
11550 </intro>
11551
11552 <errorid id="JVMTI_ERROR_NONE" num="0">
11553 No error has occurred. This is the error code that is returned
11554 on successful completion of the function.
11555 </errorid>
11556 <errorid id="JVMTI_ERROR_NULL_POINTER" num="100">
11557 Pointer is unexpectedly <code>NULL</code>.
11558 </errorid>
11559 <errorid id="JVMTI_ERROR_OUT_OF_MEMORY" num="110">
11560 The function attempted to allocate memory and no more memory was
11561 available for allocation.
11562 </errorid>
11563 <errorid id="JVMTI_ERROR_ACCESS_DENIED" num="111">
11564 The desired functionality has not been enabled in this virtual machine.
11565 </errorid>
11566 <errorid id="JVMTI_ERROR_UNATTACHED_THREAD" num="115">
11567 The thread being used to call this function is not attached
11568 to the virtual machine. Calls must be made from attached threads.
11569 See <code>AttachCurrentThread</code> in the JNI invocation API.
11570 </errorid>
11571 <errorid id="JVMTI_ERROR_INVALID_ENVIRONMENT" num="116">
11572 The <jvmti/> environment provided is no longer connected or is
11573 not an environment.
11574 </errorid>
11575 <errorid id="JVMTI_ERROR_WRONG_PHASE" num="112">
11576 The desired functionality is not available in the current
11577 <functionlink id="GetPhase">phase</functionlink>.
11578 Always returned if the virtual machine has completed running.
11579 </errorid>
11580 <errorid id="JVMTI_ERROR_INTERNAL" num="113">
11581 An unexpected internal error has occurred.
11582 </errorid>
11583 </errorcategory>
11584
11585 <errorcategory id="reqerrors" label="Function Specific Required Errors">
11586 <intro>
11587 The following errors are returned by some <jvmti/> functions and must
11588 be returned by the implementation when the condition occurs.
11589 </intro>
11590
11591 <errorid id="JVMTI_ERROR_INVALID_PRIORITY" num="12">
11592 Invalid priority.
11593 </errorid>
11594 <errorid id="JVMTI_ERROR_THREAD_NOT_SUSPENDED" num="13">
11595 Thread was not suspended.
11596 </errorid>
11597 <errorid id="JVMTI_ERROR_THREAD_SUSPENDED" num="14">
11598 Thread already suspended.
11599 </errorid>
11600 <errorid id="JVMTI_ERROR_THREAD_NOT_ALIVE" num="15">
11601 This operation requires the thread to be alive--that is,
11602 it must be started and not yet have died.
11603 </errorid>
11604 <errorid id="JVMTI_ERROR_CLASS_NOT_PREPARED" num="22">
11605 The class has been loaded but not yet prepared.
11606 </errorid>
11607 <errorid id="JVMTI_ERROR_NO_MORE_FRAMES" num="31">
11608 There are no Java programming language or JNI stack frames at the specified depth.
11609 </errorid>
11610 <errorid id="JVMTI_ERROR_OPAQUE_FRAME" num="32">
11611 Information about the frame is not available (e.g. for native frames).
11612 </errorid>
11613 <errorid id="JVMTI_ERROR_DUPLICATE" num="40">
11614 Item already set.
11615 </errorid>
11616 <errorid id="JVMTI_ERROR_NOT_FOUND" num="41">
11617 Desired element (e.g. field or breakpoint) not found
11618 </errorid>
11619 <errorid id="JVMTI_ERROR_NOT_MONITOR_OWNER" num="51">
11620 This thread doesn't own the raw monitor.
11621 </errorid>
11622 <errorid id="JVMTI_ERROR_INTERRUPT" num="52">
11623 The call has been interrupted before completion.
11624 </errorid>
11625 <errorid id="JVMTI_ERROR_UNMODIFIABLE_CLASS" num="79">
11626 The class cannot be modified.
11627 </errorid>
11628 <errorid id="JVMTI_ERROR_UNMODIFIABLE_MODULE" num="80">
11629 The module cannot be modified.
11630 </errorid>
11631 <errorid id="JVMTI_ERROR_NOT_AVAILABLE" num="98">
11632 The functionality is not available in this virtual machine.
11633 </errorid>
11634 <errorid id="JVMTI_ERROR_ABSENT_INFORMATION" num="101">
11635 The requested information is not available.
11636 </errorid>
11637 <errorid id="JVMTI_ERROR_INVALID_EVENT_TYPE" num="102">
11638 The specified event type ID is not recognized.
11639 </errorid>
11640 <errorid id="JVMTI_ERROR_NATIVE_METHOD" num="104">
11641 The requested information is not available for native method.
11642 </errorid>
11643 <errorid id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED" num="106">
11644 The class loader does not support this operation.
11645 </errorid>
11646 </errorcategory>
11647
11648 <errorcategory id="function-specific-errors" label="Function Specific Agent Errors">
11649 <intro>
11650 The following errors are returned by some <jvmti/> functions.
11651 They are returned in the event of invalid parameters passed by the
11652 agent or usage in an invalid context.
11653 An implementation is not required to detect these errors.
11654 </intro>
11655
11656 <errorid id="JVMTI_ERROR_INVALID_THREAD" num="10">
11657 The passed thread is not a valid thread.
11658 </errorid>
11659 <errorid id="JVMTI_ERROR_INVALID_FIELDID" num="25">
11660 Invalid field.
11661 </errorid>
11662 <errorid id="JVMTI_ERROR_INVALID_MODULE" num="26">
11663 Invalid module.
11664 </errorid>
11665 <errorid id="JVMTI_ERROR_INVALID_METHODID" num="23">
11666 Invalid method.
11667 </errorid>
11668 <errorid id="JVMTI_ERROR_INVALID_LOCATION" num="24">
11669 Invalid location.
11670 </errorid>
11671 <errorid id="JVMTI_ERROR_INVALID_OBJECT" num="20">
11672 Invalid object.
11673 </errorid>
11674 <errorid id="JVMTI_ERROR_INVALID_CLASS" num="21">
11675 Invalid class.
11676 </errorid>
11677 <errorid id="JVMTI_ERROR_TYPE_MISMATCH" num="34">
11678 The variable is not an appropriate type for the function used.
11679 </errorid>
11680 <errorid id="JVMTI_ERROR_INVALID_SLOT" num="35">
11681 Invalid slot.
11682 </errorid>
11683 <errorid id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY" num="99">
11684 The capability being used is false in this environment.
11685 </errorid>
11686 <errorid id="JVMTI_ERROR_INVALID_THREAD_GROUP" num="11">
11687 Thread group invalid.
11688 </errorid>
11689 <errorid id="JVMTI_ERROR_INVALID_MONITOR" num="50">
11690 Invalid raw monitor.
11691 </errorid>
11692 <errorid id="JVMTI_ERROR_ILLEGAL_ARGUMENT" num="103">
11693 Illegal argument.
11694 </errorid>
11695 <errorid id="JVMTI_ERROR_INVALID_TYPESTATE" num="65">
11696 The state of the thread has been modified, and is now inconsistent.
11697 </errorid>
11698 <errorid id="JVMTI_ERROR_UNSUPPORTED_VERSION" num="68">
11699 A new class file has a version number not supported by this VM.
11700 </errorid>
11701 <errorid id="JVMTI_ERROR_INVALID_CLASS_FORMAT" num="60">
11702 A new class file is malformed (the VM would return a <code>ClassFormatError</code>).
11703 </errorid>
11704 <errorid id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION" num="61">
11705 The new class file definitions would lead to a circular
11706 definition (the VM would return a <code>ClassCircularityError</code>).
11707 </errorid>
11708 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED" num="63">
11709 A new class file would require adding a method.
11710 </errorid>
11711 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED" num="64">
11712 A new class version changes a field.
11713 </errorid>
11714 <errorid id="JVMTI_ERROR_FAILS_VERIFICATION" num="62">
11715 The class bytes fail verification.
11716 </errorid>
11717 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED" num="66">
11718 A direct superclass is different for the new class
11719 version, or the set of directly implemented
11720 interfaces is different.
11721 </errorid>
11722 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED" num="67">
11723 A new class version does not declare a method
11724 declared in the old class version.
11725 </errorid>
11726 <errorid id="JVMTI_ERROR_NAMES_DONT_MATCH" num="69">
11727 The class name defined in the new class file is
11728 different from the name in the old class object.
11729 </errorid>
11730 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED" num="70">
11731 A new class version has different modifiers.
11732 </errorid>
11733 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED" num="71">
11734 A method in the new class version has different modifiers
11735 than its counterpart in the old class version.
11736 </errorid>
11737 </errorcategory>
11738 </errorsection>
11739
11740 <eventsection label="Events">
11741 <intro label="Handling Events" id="eventIntro">
11742 Agents can be informed of many events that occur in application
11743 programs.
11744 <p/>
11745 To handle events, designate a set of callback functions with
11746 <functionlink id="SetEventCallbacks"></functionlink>.
11747 For each event the corresponding callback function will be
11748 called.
11749 Arguments to the callback function provide additional
11750 information about the event.
11751 <p/>
11752 The callback function is usually called from within an application
11753 thread. The <jvmti/> implementation does not
11754 queue events in any way. This means
11755 that event callback functions must be written
11756 carefully. Here are some general guidelines. See
11757 the individual event descriptions for further
11758 suggestions.
11759 <p/>
11760 <ul>
11761 <li>Any exception thrown during the execution of an event callback can
11762 overwrite any current pending exception in the current application thread.
11763 Care must be taken to preserve a pending exception
11764 when an event callback makes a JNI call that might generate an exception.
11765 </li>
11766 <li>Event callback functions must be re-entrant. The <jvmti/> implementation does
11767 not queue events. If an agent needs to process events one at a time, it
11768 can use a raw monitor inside the
11769 event callback functions to serialize event processing.
11770 </li>
11771 <li>Event callback functions that execute JNI's FindClass function to load
11772 classes need to note that FindClass locates the class loader associated
11773 with the current native method. For the purposes of class loading, an
11774 event callback that includes a JNI environment as a parameter to the
11775 callback will treated as if it is a native call, where the native method
11776 is in the class of the event thread's current frame.
11777 </li>
11778 </ul>
11779 <p/>
11780 Some <jvmti/> events identify objects with JNI references.
11781 All references
11782 in <jvmti/> events are JNI local references and will become invalid
11783 after the event callback returns.
11784 Unless stated otherwise, memory referenced by pointers sent in event
11785 callbacks may not be referenced after the event callback returns.
11786 <p/>
11787 Except where stated otherwise, events are delivered on the thread
11788 that caused the event.
11789 Events are sent at the time they occur.
11790 The specification for each event includes the set of
11791 <functionlink id="GetPhase">phases</functionlink> in which it can be sent;
11792 if an event triggering activity occurs during another phase, no event
11793 is sent.
11794 <p/>
11795 A thread that generates an event does not change its execution status
11796 (for example, the event does not cause the thread to be suspended).
11797 If an agent wishes the event to result in suspension, then the agent
11798 is responsible for explicitly suspending the thread with
11799 <functionlink id="SuspendThread"></functionlink>.
11800 <p/>
11801 If an event is enabled in multiple environments, the event will be sent
11802 to each agent in the order that the environments were created.
11803 </intro>
11804
11805 <intro label="Enabling Events" id="enablingevents">
11806 All events are initially disabled. In order to receive any
11807 event:
11808 <ul>
11809 <li>
11810 If the event requires a capability, that capability must
11811 be added with
11812 <functionlink id="AddCapabilities"></functionlink>.
11813 </li>
11814 <li>
11815 A callback for the event must be set with
11816 <functionlink id="SetEventCallbacks"></functionlink>.
11817 </li>
11818 <li>
11819 The event must be enabled with
11820 <functionlink id="SetEventNotificationMode"></functionlink>.
11821 </li>
11822 </ul>
11823 </intro>
11824
11825 <intro label="Multiple Co-located Events" id="eventorder">
11826 In many situations it is possible for multiple events to occur
11827 at the same location in one thread. When this happens, all the events
11828 are reported through the event callbacks in the order specified in this section.
11829 <p/>
11830 If the current location is at the entry point of a method, the
11831 <eventlink id="MethodEntry"></eventlink> event is reported before
11832 any other event at the current location in the same thread.
11833 <p/>
11834 If an exception catch has been detected at the current location,
11835 either because it is the beginning of a catch clause or a native method
11836 that cleared a pending exception has returned, the
11837 <code>exceptionCatch</code> event is reported before
11838 any other event at the current location in the same thread.
11839 <p/>
11840 If a <code>singleStep</code> event or
11841 <code>breakpoint</code> event is triggered at the
11842 current location, the event is defined to occur
11843 immediately before the code at the current location is executed.
11844 These events are reported before any events which are triggered
11845 by the execution of code at the current location in the same
11846 thread (specifically:
11847 <code>exception</code>,
11848 <code>fieldAccess</code>, and
11849 <code>fieldModification</code>).
11850 If both a step and breakpoint event are triggered for the same thread and
11851 location, the step event is reported before the breakpoint event.
11852 <p/>
11853 If the current location is the exit point of a method (that is, the last
11854 location before returning to the caller), the
11855 <eventlink id="MethodExit"></eventlink> event and
11856 the <eventlink id="FramePop"></eventlink> event (if requested)
11857 are reported after all other events at the current location in the same
11858 thread. There is no specified ordering of these two events
11859 with respect to each other.
11860 <p/>
11861 Co-located events can be triggered during the processing of some other
11862 event by the agent at the same location in the same thread.
11863 If such an event, of type <i>y</i>, is triggered during the processing of
11864 an event of type <i>x</i>, and if <i>x</i>
11865 precedes <i>y</i> in the ordering specified above, the co-located event
11866 <i>y</i> is reported for the current thread and location. If <i>x</i> does not precede
11867 <i>y</i>, <i>y</i> is not reported for the current thread and location.
11868 For example, if a breakpoint is set at the current location
11869 during the processing of <eventlink id="SingleStep"></eventlink>,
11870 that breakpoint will be reported before the thread moves off the current
11871 location.
11872 <p/>The following events are never considered to be co-located with
11873 other events.
11874 <ul>
11875 <li><eventlink id="VMStart"></eventlink></li>
11876 <li><eventlink id="VMInit"></eventlink></li>
11877 <li><eventlink id="VMDeath"></eventlink></li>
11878 <li><eventlink id="ThreadStart"></eventlink></li>
11879 <li><eventlink id="ThreadEnd"></eventlink></li>
11880 <li><eventlink id="ClassLoad"></eventlink></li>
11881 <li><eventlink id="ClassPrepare"></eventlink></li>
11882 </ul>
11883 </intro>
11884
11885 <intro label="Event Callbacks" id="jvmtiEventCallbacks">
11886 The event callback structure below is used to specify the handler function
11887 for events. It is set with the
11888 <functionlink id="SetEventCallbacks"></functionlink> function.
11889 </intro>
11890
11891 <event label="Single Step"
11892 id="SingleStep" const="JVMTI_EVENT_SINGLE_STEP" filtered="thread" num="60">
11893 <description>
11894 Single step events allow the agent to trace thread execution
11895 at the finest granularity allowed by the VM. A single step event is
11896 generated whenever a thread reaches a new location.
11897 Typically, single step events represent the completion of one VM
11898 instruction as defined in <vmspec/>. However, some implementations
11899 may define locations differently. In any case the
11900 <code>method</code> and <code>location</code>
11901 parameters uniquely identify the current location and allow
11902 the mapping to source file and line number when that information is
11903 available.
11904 <p/>
11905 No single step events are generated from within native methods.
11906 </description>
11907 <origin>jvmdi</origin>
11908 <capabilities>
11909 <required id="can_generate_single_step_events"></required>
11910 </capabilities>
11911 <parameters>
11912 <param id="jni_env">
11913 <outptr>
11914 <struct>JNIEnv</struct>
11915 </outptr>
11916 <description>
11917 The JNI environment of the event (current) thread
11918 </description>
11919 </param>
11920 <param id="thread">
11921 <jthread/>
11922 <description>
11923 Thread about to execution a new instruction
11924 </description>
11925 </param>
11926 <param id="klass">
11927 <jclass method="method"/>
11928 <description>
11929 Class of the method about to execute a new instruction
11930 </description>
11931 </param>
11932 <param id="method">
11933 <jmethodID class="klass"/>
11934 <description>
11935 Method about to execute a new instruction
11936 </description>
11937 </param>
11938 <param id="location">
11939 <jlocation/>
11940 <description>
11941 Location of the new instruction
11942 </description>
11943 </param>
11944 </parameters>
11945 </event>
11946
11947 <event label="Breakpoint"
11948 id="Breakpoint" const="JVMTI_EVENT_BREAKPOINT" filtered="thread" num="62">
11949 <description>
11950 Breakpoint events are generated whenever a thread reaches a location
11951 designated as a breakpoint with <functionlink id="SetBreakpoint"></functionlink>.
11952 The <code>method</code> and <code>location</code>
11953 parameters uniquely identify the current location and allow
11954 the mapping to source file and line number when that information is
11955 available.
11956 </description>
11957 <origin>jvmdi</origin>
11958 <capabilities>
11959 <required id="can_generate_breakpoint_events"></required>
11960 </capabilities>
11961 <parameters>
11962 <param id="jni_env">
11963 <outptr>
11964 <struct>JNIEnv</struct>
11965 </outptr>
11966 <description>
11967 The JNI environment of the event (current) thread.
11968 </description>
11969 </param>
11970 <param id="thread">
11971 <jthread/>
11972 <description>
11973 Thread that hit the breakpoint
11974 </description>
11975 </param>
11976 <param id="klass">
11977 <jclass method="method"/>
11978 <description>
11979 Class of the method that hit the breakpoint
11980 </description>
11981 </param>
11982 <param id="method">
11983 <jmethodID class="klass"/>
11984 <description>
11985 Method that hit the breakpoint
11986 </description>
11987 </param>
11988 <param id="location">
11989 <jlocation/>
11990 <description>
11991 location of the breakpoint
11992 </description>
11993 </param>
11994 </parameters>
11995 </event>
11996
11997 <event label="Field Access"
11998 id="FieldAccess" const="JVMTI_EVENT_FIELD_ACCESS" filtered="thread" num="63">
11999 <description>
12000 Field access events are generated whenever a thread accesses
12001 a field that was designated as a watchpoint
12002 with <functionlink id="SetFieldAccessWatch"></functionlink>.
12003 The <code>method</code> and <code>location</code>
12004 parameters uniquely identify the current location and allow
12005 the mapping to source file and line number when that information is
12006 available.
12007 </description>
12008 <origin>jvmdi</origin>
12009 <capabilities>
12010 <required id="can_generate_field_access_events"></required>
12011 </capabilities>
12012 <parameters>
12013 <param id="jni_env">
12014 <outptr>
12015 <struct>JNIEnv</struct>
12016 </outptr>
12017 <description>
12018 The JNI environment of the event (current) thread
12019 </description>
12020 </param>
12021 <param id="thread">
12022 <jthread/>
12023 <description>
12024 Thread accessing the field
12025 </description>
12026 </param>
12027 <param id="klass">
12028 <jclass method="method"/>
12029 <description>
12030 Class of the method where the access is occurring
12031 </description>
12032 </param>
12033 <param id="method">
12034 <jmethodID class="klass"/>
12035 <description>
12036 Method where the access is occurring
12037 </description>
12038 </param>
12039 <param id="location">
12040 <jlocation/>
12041 <description>
12042 Location where the access is occurring
12043 </description>
12044 </param>
12045 <param id="field_klass">
12046 <jclass field="field"/>
12047 <description>
12048 Class of the field being accessed
12049 </description>
12050 </param>
12051 <param id="object">
12052 <jobject/>
12053 <description>
12054 Object with the field being accessed if the field is an
12055 instance field; <code>NULL</code> otherwise
12056 </description>
12057 </param>
12058 <param id="field">
12059 <jfieldID class="field_klass"/>
12060 <description>
12061 Field being accessed
12062 </description>
12063 </param>
12064 </parameters>
12065 </event>
12066
12067 <event label="Field Modification"
12068 id="FieldModification" const="JVMTI_EVENT_FIELD_MODIFICATION" filtered="thread" num="64">
12069 <description>
12070 Field modification events are generated whenever a thread modifies
12071 a field that was designated as a watchpoint
12072 with <functionlink id="SetFieldModificationWatch"></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_field_modification_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 modifying the field
12095 </description>
12096 </param>
12097 <param id="klass">
12098 <jclass method="method"/>
12099 <description>
12100 Class of the method where the modification is occurring
12101 </description>
12102 </param>
12103 <param id="method">
12104 <jmethodID class="klass"/>
12105 <description>
12106 Method where the modification is occurring
12107 </description>
12108 </param>
12109 <param id="location">
12110 <jlocation/>
12111 <description>
12112 Location where the modification is occurring
12113 </description>
12114 </param>
12115 <param id="field_klass">
12116 <jclass field="field"/>
12117 <description>
12118 Class of the field being modified
12119 </description>
12120 </param>
12121 <param id="object">
12122 <jobject/>
12123 <description>
12124 Object with the field being modified if the field is an
12125 instance field; <code>NULL</code> otherwise
12126 </description>
12127 </param>
12128 <param id="field">
12129 <jfieldID class="field_klass"/>
12130 <description>
12131 Field being modified
12132 </description>
12133 </param>
12134 <param id="signature_type">
12135 <char/>
12136 <description>
12137 Signature type of the new value
12138 </description>
12139 </param>
12140 <param id="new_value">
12141 <jvalue/>
12142 <description>
12143 The new value
12144 </description>
12145 </param>
12146 </parameters>
12147 </event>
12148
12149 <event label="Frame Pop"
12150 id="FramePop" const="JVMTI_EVENT_FRAME_POP" filtered="thread" num="61">
12151 <description>
12152 Frame pop events are generated upon exit from a single method
12153 in a single frame as specified
12154 in a call to <functionlink id="NotifyFramePop"></functionlink>.
12155 This is true whether termination is caused by
12156 executing its return instruction
12157 or by throwing an exception to its caller
12158 (see <paramlink id="was_popped_by_exception"></paramlink>).
12159 However, frame pops caused by the <functionlink id="PopFrame"/>
12160 function are not reported.
12161 <p/>
12162 The location reported by <functionlink id="GetFrameLocation"></functionlink>
12163 identifies the executable location in the returning method,
12164 immediately prior to the return.
12165 </description>
12166 <origin>jvmdi</origin>
12167 <capabilities>
12168 <required id="can_generate_frame_pop_events"></required>
12169 </capabilities>
12170 <parameters>
12171 <param id="jni_env">
12172 <outptr>
12173 <struct>JNIEnv</struct>
12174 </outptr>
12175 <description>
12176 The JNI environment of the event (current) thread
12177 </description>
12178 </param>
12179 <param id="thread">
12180 <jthread/>
12181 <description>
12182 Thread that is popping the frame
12183 </description>
12184 </param>
12185 <param id="klass">
12186 <jclass method="method"/>
12187 <description>
12188 Class of the method being popped
12189 </description>
12190 </param>
12191 <param id="method">
12192 <jmethodID class="klass"/>
12193 <description>
12194 Method being popped
12195 </description>
12196 </param>
12197 <param id="was_popped_by_exception">
12198 <jboolean/>
12199 <description>
12200 True if frame was popped by a thrown exception.
12201 False if method exited through its return instruction.
12202 </description>
12203 </param>
12204 </parameters>
12205 </event>
12206
12207 <event label="Method Entry"
12208 id="MethodEntry" const="JVMTI_EVENT_METHOD_ENTRY" filtered="thread" num="65">
12209 <description>
12210 Method entry events are generated upon entry of Java
12211 programming language methods (including native methods).
12212 <p/>
12213 The location reported by <functionlink id="GetFrameLocation"></functionlink>
12214 identifies the initial executable location in
12215 the method.
12216 <p/>
12217 Enabling method
12218 entry or exit events will significantly degrade performance on many platforms and is thus
12219 not advised for performance critical usage (such as profiling).
12220 <internallink id="bci">Bytecode instrumentation</internallink> should be
12221 used in these cases.
12222 </description>
12223 <origin>jvmdi</origin>
12224 <capabilities>
12225 <required id="can_generate_method_entry_events"></required>
12226 </capabilities>
12227 <parameters>
12228 <param id="jni_env">
12229 <outptr>
12230 <struct>JNIEnv</struct>
12231 </outptr>
12232 <description>
12233 The JNI environment of the event (current) thread
12234 </description>
12235 </param>
12236 <param id="thread">
12237 <jthread/>
12238 <description>
12239 Thread entering the method
12240 </description>
12241 </param>
12242 <param id="klass">
12243 <jclass method="method"/>
12244 <description>
12245 Class of the method being entered
12246 </description>
12247 </param>
12248 <param id="method">
12249 <jmethodID class="klass"/>
12250 <description>
12251 Method being entered
12252 </description>
12253 </param>
12254 </parameters>
12255 </event>
12256
12257 <event label="Method Exit"
12258 id="MethodExit" const="JVMTI_EVENT_METHOD_EXIT" filtered="thread" num="66">
12259 <description>
12260 Method exit events are generated upon exit from Java
12261 programming language methods (including native methods).
12262 This is true whether termination is caused by
12263 executing its return instruction
12264 or by throwing an exception to its caller
12265 (see <paramlink id="was_popped_by_exception"></paramlink>).
12266 <p/>
12267 The <code>method</code> field uniquely identifies the
12268 method being entered or exited. The <code>frame</code> field provides
12269 access to the stack frame for the method.
12270 <p/>
12271 The location reported by <functionlink id="GetFrameLocation"></functionlink>
12272 identifies the executable location in the returning method
12273 immediately prior to the return.
12274 <p/>
12275 Enabling method
12276 entry or exit events will significantly degrade performance on many platforms and is thus
12277 not advised for performance critical usage (such as profiling).
12278 <internallink id="bci">Bytecode instrumentation</internallink> should be
12279 used in these cases.
12280 </description>
12281 <origin>jvmdi</origin>
12282 <capabilities>
12283 <required id="can_generate_method_exit_events"></required>
12284 </capabilities>
12285 <parameters>
12286 <param id="jni_env">
12287 <outptr>
12288 <struct>JNIEnv</struct>
12289 </outptr>
12290 <description>
12291 The JNI environment of the event (current) thread
12292 </description>
12293 </param>
12294 <param id="thread">
12295 <jthread/>
12296 <description>
12297 Thread exiting the method
12298 </description>
12299 </param>
12300 <param id="klass">
12301 <jclass method="method"/>
12302 <description>
12303 Class of the method being exited
12304 </description>
12305 </param>
12306 <param id="method">
12307 <jmethodID class="klass"/>
12308 <description>
12309 Method being exited
12310 </description>
12311 </param>
12312 <param id="was_popped_by_exception">
12313 <jboolean/>
12314 <description>
12315 True if frame was popped by a thrown exception.
12316 False if method exited through its return instruction.
12317 </description>
12318 </param>
12319 <param id="return_value">
12320 <jvalue/>
12321 <description>
12322 The return value of the method being exited.
12323 Undefined and should not be used if
12324 <paramlink id="was_popped_by_exception"></paramlink>
12325 is true.
12326 </description>
12327 </param>
12328 </parameters>
12329 </event>
12330
12331 <event label="Native Method Bind" phase="any"
12332 id="NativeMethodBind" const="JVMTI_EVENT_NATIVE_METHOD_BIND" num="67">
12333 <description>
12334 A Native Method Bind event is sent when a VM binds a
12335 Java programming language native method
12336 to the address of a function that implements the native method.
12337 This will occur when the native method is called for the first time
12338 and also occurs when the JNI function <code>RegisterNatives</code> is called.
12339 This event allows the bind to be redirected to an agent-specified
12340 proxy function.
12341 This event is not sent when the native method is unbound.
12342 Typically, this proxy function will need to be specific to a
12343 particular method or, to handle the general case, automatically
12344 generated assembly code, since after instrumentation code is
12345 executed the function at the original binding
12346 address will usually be invoked.
12347 The original binding can be restored or the redirection changed
12348 by use of the JNI function <code>RegisterNatives</code>.
12349 Some events may be sent during the primordial phase, JNI and
12350 most of <jvmti/> cannot be used at this time but the method and
12351 address can be saved for use later.
12352 </description>
12353 <origin>new</origin>
12354 <capabilities>
12355 <required id="can_generate_native_method_bind_events"></required>
12356 </capabilities>
12357 <parameters>
12358 <param id="jni_env">
12359 <outptr>
12360 <struct>JNIEnv</struct>
12361 </outptr>
12362 <description>
12363 The JNI environment of the event (current) thread
12364 Will be <code>NULL</code> if sent during the primordial
12365 <functionlink id="GetPhase">phase</functionlink>.
12366 </description>
12367 </param>
12368 <param id="thread">
12369 <jthread/>
12370 <description>
12371 Thread requesting the bind
12372 </description>
12373 </param>
12374 <param id="klass">
12375 <jclass method="method"/>
12376 <description>
12377 Class of the method being bound
12378 </description>
12379 </param>
12380 <param id="method">
12381 <jmethodID class="klass"/>
12382 <description>
12383 Native method being bound
12384 </description>
12385 </param>
12386 <param id="address">
12387 <outptr><void/></outptr>
12388 <description>
12389 The address the VM is about to bind to--that is, the
12390 address of the implementation of the native method
12391 </description>
12392 </param>
12393 <param id="new_address_ptr">
12394 <agentbuf><void/></agentbuf>
12395 <description>
12396 if the referenced address is changed (that is, if
12397 <code>*new_address_ptr</code> is set), the binding
12398 will instead be made to the supplied address.
12399 </description>
12400 </param>
12401 </parameters>
12402 </event>
12403
12404 <event label="Exception"
12405 id="Exception" const="JVMTI_EVENT_EXCEPTION" filtered="thread" num="58">
12406 <description>
12407 Exception events are generated whenever an exception is first detected
12408 in a Java programming language method.
12409 Where "exception" means any <code>java.lang.Throwable</code>.
12410 The exception may have been thrown by a Java programming language or native
12411 method, but in the case of native methods, the event is not generated
12412 until the exception is first seen by a Java programming language method. If an exception is
12413 set and cleared in a native method (and thus is never visible to Java programming language code),
12414 no exception event is generated.
12415 <p/>
12416 The <code>method</code> and <code>location</code>
12417 parameters uniquely identify the current location
12418 (where the exception was detected) and allow
12419 the mapping to source file and line number when that information is
12420 available. The <code>exception</code> field identifies the thrown
12421 exception object. The <code>catch_method</code>
12422 and <code>catch_location</code> identify the location of the catch clause,
12423 if any, that handles the thrown exception. If there is no such catch clause,
12424 each field is set to 0. There is no guarantee that the thread will ever
12425 reach this catch clause. If there are native methods on the call stack
12426 between the throw location and the catch clause, the exception may
12427 be reset by one of those native methods.
12428 Similarly, exceptions that are reported as uncaught (<code>catch_klass</code>
12429 et al. set to 0) may in fact be caught by native code.
12430 Agents can check for these occurrences by monitoring
12431 <eventlink id="ExceptionCatch"></eventlink> events.
12432 Note that finally clauses are implemented as catch and re-throw. Therefore they
12433 will be reported in the catch location.
12434 </description>
12435 <origin>jvmdi</origin>
12436 <capabilities>
12437 <required id="can_generate_exception_events"></required>
12438 </capabilities>
12439 <parameters>
12440 <param id="jni_env">
12441 <outptr>
12442 <struct>JNIEnv</struct>
12443 </outptr>
12444 <description>
12445 The JNI environment of the event (current) thread
12446 </description>
12447 </param>
12448 <param id="thread">
12449 <jthread/>
12450 <description>
12451 Thread generating the exception
12452 </description>
12453 </param>
12454 <param id="klass">
12455 <jclass method="method"/>
12456 <description>
12457 Class generating the exception
12458 </description>
12459 </param>
12460 <param id="method">
12461 <jmethodID class="klass"/>
12462 <description>
12463 Method generating the exception
12464 </description>
12465 </param>
12466 <param id="location">
12467 <jlocation/>
12468 <description>
12469 Location where exception occurred
12470 </description>
12471 </param>
12472 <param id="exception">
12473 <jobject/>
12474 <description>
12475 The exception being thrown
12476 </description>
12477 </param>
12478 <param id="catch_klass">
12479 <jclass method="catch_method"/>
12480 <description>
12481 Class that will catch the exception, or <code>NULL</code> if no known catch
12482 </description>
12483 </param>
12484 <param id="catch_method">
12485 <jmethodID class="catch_klass"/>
12486 <description>
12487 Method that will catch the exception, or <code>NULL</code> if no known catch
12488 </description>
12489 </param>
12490 <param id="catch_location">
12491 <jlocation/>
12492 <description>
12493 location which will catch the exception or zero if no known catch
12494 </description>
12495 </param>
12496 </parameters>
12497 </event>
12498
12499 <event label="Exception Catch"
12500 id="ExceptionCatch" const="JVMTI_EVENT_EXCEPTION_CATCH" filtered="thread" num="59">
12501 <description>
12502 Exception catch events are generated whenever a thrown exception is caught.
12503 Where "exception" means any <code>java.lang.Throwable</code>.
12504 If the exception is caught in a Java programming language method, the event is generated
12505 when the catch clause is reached. If the exception is caught in a native
12506 method, the event is generated as soon as control is returned to a Java programming language
12507 method. Exception catch events are generated for any exception for which
12508 a throw was detected in a Java programming language method.
12509 Note that finally clauses are implemented as catch and re-throw. Therefore they
12510 will generate exception catch events.
12511 <p/>
12512 The <code>method</code> and <code>location</code>
12513 parameters uniquely identify the current location
12514 and allow the mapping to source file and line number when that information is
12515 available. For exceptions caught in a Java programming language method, the
12516 <code>exception</code> object identifies the exception object. Exceptions
12517 caught in native methods are not necessarily available by the time the
12518 exception catch is reported, so the <code>exception</code> field is set
12519 to <code>NULL</code>.
12520 </description>
12521 <origin>jvmdi</origin>
12522 <capabilities>
12523 <required id="can_generate_exception_events"></required>
12524 </capabilities>
12525 <parameters>
12526 <param id="jni_env">
12527 <outptr>
12528 <struct>JNIEnv</struct>
12529 </outptr>
12530 <description>
12531 The JNI environment of the event (current) thread
12532 </description>
12533 </param>
12534 <param id="thread">
12535 <jthread/>
12536 <description>
12537 Thread catching the exception
12538 </description>
12539 </param>
12540 <param id="klass">
12541 <jclass method="method"/>
12542 <description>
12543 Class catching the exception
12544 </description>
12545 </param>
12546 <param id="method">
12547 <jmethodID class="klass"/>
12548 <description>
12549 Method catching the exception
12550 </description>
12551 </param>
12552 <param id="location">
12553 <jlocation/>
12554 <description>
12555 Location where exception is being caught
12556 </description>
12557 </param>
12558 <param id="exception">
12559 <jobject/>
12560 <description>
12561 Exception being caught
12562 </description>
12563 </param>
12564 </parameters>
12565 </event>
12566
12567 <event label="Thread Start"
12568 id="ThreadStart" const="JVMTI_EVENT_THREAD_START" num="52" phase="start">
12569 <description>
12570 Thread start events are generated by a new thread before its initial
12571 method executes.
12572 <p/>
12573 A thread may be listed in the array returned by
12574 <functionlink id="GetAllThreads"></functionlink>
12575 before its thread start event is generated.
12576 It is possible for other events to be generated
12577 on a thread before its thread start event.
12578 <p/>
12579 The event is sent on the newly started <paramlink id="thread"></paramlink>.
12580 </description>
12581 <origin>jvmdi</origin>
12582 <capabilities>
12583 </capabilities>
12584 <parameters>
12585 <param id="jni_env">
12586 <outptr>
12587 <struct>JNIEnv</struct>
12588 </outptr>
12589 <description>
12590 The JNI environment of the event (current) thread.
12591 </description>
12592 </param>
12593 <param id="thread">
12594 <jthread/>
12595 <description>
12596 Thread starting
12597 </description>
12598 </param>
12599 </parameters>
12600 </event>
12601
12602 <event label="Thread End"
12603 id="ThreadEnd" const="JVMTI_EVENT_THREAD_END" filtered="thread" num="53" phase="start">
12604 <description>
12605 Thread end events are generated by a terminating thread
12606 after its initial method has finished execution.
12607 <p/>
12608 A thread may be listed in the array returned by
12609 <functionlink id="GetAllThreads"></functionlink>
12610 after its thread end event is generated.
12611 No events are generated on a thread
12612 after its thread end event.
12613 <p/>
12614 The event is sent on the dying <paramlink id="thread"></paramlink>.
12615 </description>
12616 <origin>jvmdi</origin>
12617 <capabilities>
12618 </capabilities>
12619 <parameters>
12620 <param id="jni_env">
12621 <outptr>
12622 <struct>JNIEnv</struct>
12623 </outptr>
12624 <description>
12625 The JNI environment of the event (current) thread.
12626 </description>
12627 </param>
12628 <param id="thread">
12629 <jthread/>
12630 <description>
12631 Thread ending
12632 </description>
12633 </param>
12634 </parameters>
12635 </event>
12636
12637 <event label="Class Load"
12638 id="ClassLoad" const="JVMTI_EVENT_CLASS_LOAD" filtered="thread" phase="start" num="55">
12639 <description>
12640 A class load event is generated when a class is first loaded. The order
12641 of class load events generated by a particular thread are guaranteed
12642 to match the order of class loading within that thread.
12643 Array class creation does not generate a class load event.
12644 The creation of a primitive class (for example, java.lang.Integer.TYPE)
12645 does not generate a class load event.
12646 <p/>
12647 This event is sent at an early stage in loading the class. As
12648 a result the class should be used carefully. Note, for example,
12649 that methods and fields are not yet loaded, so queries for methods,
12650 fields, subclasses, and so on will not give correct results.
12651 See "Loading of Classes and Interfaces" in the <i>Java Language
12652 Specification</i>. For most
12653 purposes the <eventlink id="ClassPrepare"></eventlink> event will
12654 be more useful.
12655 </description>
12656 <origin>jvmdi</origin>
12657 <capabilities>
12658 </capabilities>
12659 <parameters>
12660 <param id="jni_env">
12661 <outptr>
12662 <struct>JNIEnv</struct>
12663 </outptr>
12664 <description>
12665 The JNI environment of the event (current) thread
12666 </description>
12667 </param>
12668 <param id="thread">
12669 <jthread/>
12670 <description>
12671 Thread loading the class
12672 </description>
12673 </param>
12674 <param id="klass">
12675 <jclass/>
12676 <description>
12677 Class being loaded
12678 </description>
12679 </param>
12680 </parameters>
12681 </event>
12682
12683 <elide>
12684 <event label="Class Unload"
12685 id="ClassUnload" const="JVMTI_EVENT_CLASS_UNLOAD" num="57">
12686 <description>
12687 A class unload event is generated when the class is about to be unloaded.
12688 Class unload events take place during garbage collection and must be
12689 handled extremely carefully. The garbage collector holds many locks
12690 and has suspended all other threads, so the event handler cannot depend
12691 on the ability to acquire any locks. The class unload event handler should
12692 do as little as possible, perhaps by queuing information to be processed
12693 later. In particular, the <code>jclass</code> should be used only in
12694 the JNI function <code>isSameObject</code> or in the following <jvmti/> functions:
12695 <ul>
12696 <li><functionlink id="GetClassSignature"></functionlink></li>
12697 <li><functionlink id="GetSourceFileName"></functionlink></li>
12698 <li><functionlink id="IsInterface"></functionlink></li>
12699 <li><functionlink id="IsArrayClass"></functionlink></li>
12700 </ul>
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 generating the class unload
12718 </description>
12719 </param>
12720 <param id="klass">
12721 <jclass/>
12722 <description>
12723 Class being unloaded
12724 </description>
12725 </param>
12726 </parameters>
12727 </event>
12728 </elide>
12729
12730 <event label="Class Prepare"
12731 id="ClassPrepare" const="JVMTI_EVENT_CLASS_PREPARE" filtered="thread" phase="start" num="56">
12732 <description>
12733 A class prepare event is generated when class preparation is complete.
12734 At this point, class fields, methods, and implemented interfaces are
12735 available, and no code from the class has been executed. Since array
12736 classes never have fields or methods, class prepare events are not
12737 generated for them. Class prepare events are not generated for
12738 primitive classes (for example, <code>java.lang.Integer.TYPE</code>).
12739 </description>
12740 <origin>jvmdi</origin>
12741 <capabilities>
12742 </capabilities>
12743 <parameters>
12744 <param id="jni_env">
12745 <outptr>
12746 <struct>JNIEnv</struct>
12747 </outptr>
12748 <description>
12749 The JNI environment of the event (current) thread
12750 </description>
12751 </param>
12752 <param id="thread">
12753 <jthread/>
12754 <description>
12755 Thread generating the class prepare
12756 </description>
12757 </param>
12758 <param id="klass">
12759 <jclass/>
12760 <description>
12761 Class being prepared
12762 </description>
12763 </param>
12764 </parameters>
12765 </event>
12766
12767 <event label="Class File Load Hook" phase="any"
12768 id="ClassFileLoadHook" const="JVMTI_EVENT_CLASS_FILE_LOAD_HOOK" num="54">
12769 <description>
12770 This event is sent when the VM obtains class file data,
12771 but before it constructs
12772 the in-memory representation for that class.
12773 This event is also sent when the class is being modified by the
12774 <functionlink id="RetransformClasses"/> function or
12775 the <functionlink id="RedefineClasses"/> function,
12776 called in any <jvmti/> environment.
12777 The agent can instrument
12778 the existing class file data sent by the VM to include profiling/debugging hooks.
12779 See the description of
12780 <internallink id="bci">bytecode instrumentation</internallink>
12781 for usage information.
12782 <p/>
12783 When the capabilities
12784 <internallink id="jvmtiCapabilities.can_generate_early_class_hook_events">
12785 <code>can_generate_early_class_hook_events</code></internallink> and
12786 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events">
12787 <code>can_generate_all_class_hook_events</code></internallink>
12788 are enabled then this event may be sent in the primordial phase.
12789 Otherwise, this event may be sent before the VM is initialized (the start
12790 <functionlink id="GetPhase">phase</functionlink>).
12791 Some classes might not be compatible
12792 with the function (eg. ROMized classes or implementation defined classes) and this event will
12793 not be generated for these classes.
12794 <p/>
12795 The agent must allocate the space for the modified
12796 class file data buffer
12797 using the memory allocation function
12798 <functionlink id="Allocate"></functionlink> because the
12799 VM is responsible for freeing the new class file data buffer
12800 using <functionlink id="Deallocate"></functionlink>.
12801 <p/>
12802 If the agent wishes to modify the class file, it must set
12803 <code>new_class_data</code> to point
12804 to the newly instrumented class file data buffer and set
12805 <code>new_class_data_len</code> to the length of that
12806 buffer before returning
12807 from this call. If no modification is desired, the agent simply
12808 does not set <code>new_class_data</code>. If multiple agents
12809 have enabled this event the results are chained. That is, if
12810 <code>new_class_data</code> has been set, it becomes the
12811 <code>class_data</code> for the next agent.
12812 <p/>
12813 When handling a class load in the live phase, then the
12814 <functionlink id="GetNamedModule"></functionlink>
12815 function can be used to map class loader and a package name to a module.
12816 When a class is being redefined or retransformed then
12817 <code>class_being_redefined</code> is non <code>NULL</code> and so
12818 the JNI <code>GetModule</code> function can also be used
12819 to obtain the Module.
12820 <p/>
12821 The order that this event is sent to each environment differs
12822 from other events.
12823 This event is sent to environments in the following order:
12824 <ul>
12825 <li><fieldlink id="can_retransform_classes"
12826 struct="jvmtiCapabilities">retransformation
12827 incapable</fieldlink>
12828 environments, in the
12829 order in which they were created
12830 </li>
12831 <li><fieldlink id="can_retransform_classes"
12832 struct="jvmtiCapabilities">retransformation
12833 capable</fieldlink>
12834 environments, in the
12835 order in which they were created
12836 </li>
12837 </ul>
12838 When triggered by <functionlink id="RetransformClasses"/>,
12839 this event is sent only to <fieldlink id="can_retransform_classes"
12840 struct="jvmtiCapabilities">retransformation
12841 capable</fieldlink>
12842 environments.
12843 </description>
12844 <origin>jvmpi</origin>
12845 <capabilities>
12846 <capability id="can_generate_all_class_hook_events"></capability>
12847 <capability id="can_generate_early_class_hook_events"></capability>
12848 </capabilities>
12849 <parameters>
12850 <param id="jni_env">
12851 <outptr>
12852 <struct>JNIEnv</struct>
12853 </outptr>
12854 <description>
12855 The JNI environment of the event (current) thread.
12856 </description>
12857 </param>
12858 <param id="class_being_redefined">
12859 <jclass/>
12860 <description>
12861 The class being
12862 <functionlink id="RedefineClasses">redefined</functionlink> or
12863 <functionlink id="RetransformClasses">retransformed</functionlink>.
12864 <code>NULL</code> if sent by class load.
12865 </description>
12866 </param>
12867 <param id="loader">
12868 <jobject/>
12869 <description>
12870 The class loader loading the class.
12871 <code>NULL</code> if the bootstrap class loader.
12872 </description>
12873 </param>
12874 <param id="name">
12875 <vmbuf><char/></vmbuf>
12876 <description>
12877 Name of class being loaded as a VM internal qualified name
12878 (for example, "java/util/List"), encoded as a
12879 <internallink id="mUTF">modified UTF-8</internallink> string.
12880 Note: if the class is defined with a <code>NULL</code> name or
12881 without a name specified, <code>name</code> will be <code>NULL</code>.
12882 </description>
12883 </param>
12884 <param id="protection_domain">
12885 <jobject/>
12886 <description>
12887 The <code>ProtectionDomain</code> of the class.
12888 </description>
12889 </param>
12890 <param id="class_data_len">
12891 <jint/>
12892 <description>
12893 Length of current class file data buffer.
12894 </description>
12895 </param>
12896 <param id="class_data">
12897 <vmbuf><uchar/></vmbuf>
12898 <description>
12899 Pointer to the current class file data buffer.
12900 </description>
12901 </param>
12902 <param id="new_class_data_len">
12903 <outptr><jint/></outptr>
12904 <description>
12905 Pointer to the length of the new class file data buffer.
12906 </description>
12907 </param>
12908 <param id="new_class_data">
12909 <agentbuf incount="new_class_data_len"><uchar/></agentbuf>
12910 <description>
12911 Pointer to the pointer to the instrumented class file data buffer.
12912 </description>
12913 </param>
12914 </parameters>
12915 </event>
12916
12917 <event label="VM Start Event"
12918 id="VMStart" const="JVMTI_EVENT_VM_START" num="57" phase="start">
12919 <description>
12920 The VM start event signals the start of the VM.
12921 At this time JNI is live but the VM is not yet fully initialized.
12922 Once this event is generated, the agent is free to call any JNI function.
12923 This event signals the beginning of the start phase,
12924 <jvmti/> functions permitted in the start phase may be called.
12925 <p/>
12926 The timing of this event may depend on whether the agent has added the
12927 <internallink id="jvmtiCapabilities.can_generate_early_vmstart">
12928 <code>can_generate_early_vmstart</code></internallink> capability or not.
12929 If the capability has been added then the VM posts the event as early
12930 as possible. The VM is capable of executing bytecode but it may not have
12931 initialized to the point where it can load classes in modules other than
12932 <code>java.base</code>, or even arbitrary classes in <code>java.base</code>.
12933 Agents that do load-time instrumentation in this
12934 phase must take great care when instrumenting code that potentially
12935 executes in this phase. Extreme care should also be taken with JNI
12936 <code>FindClass</code> as it may not be possible to load classes and attempts
12937 to do so may result in unpredictable behavior, maybe even stability issues
12938 on some VM implementations.
12939 If the capability has not been added then the VM delays posting this
12940 event until it is capable of loading classes in modules other than
12941 <code>java.base</code> or the VM has completed its initialization.
12942 Agents that create more than one JVM TI environment, where the
12943 capability is added to some but not all environments, may observe the
12944 start phase beginning earlier in the JVM TI environments that possess
12945 the capabilty.
12946 <p/>
12947 In the case of VM start-up failure, this event will not be sent.
12948 </description>
12949 <origin>jvmdi</origin>
12950 <capabilities>
12951 </capabilities>
12952 <parameters>
12953 <param id="jni_env">
12954 <outptr>
12955 <struct>JNIEnv</struct>
12956 </outptr>
12957 <description>
12958 The JNI environment of the event (current) thread.
12959 </description>
12960 </param>
12961 </parameters>
12962 </event>
12963
12964 <event label="VM Initialization Event"
12965 id="VMInit" const="JVMTI_EVENT_VM_INIT" num="50">
12966 <description>
12967 The VM initialization event signals the completion of VM initialization. Once
12968 this event is generated, the agent is free to call any JNI or <jvmti/>
12969 function. The VM initialization event can be preceded by or can be concurrent
12970 with other events, but
12971 the preceding events should be handled carefully, if at all, because the
12972 VM has not completed its initialization. The thread start event for the
12973 main application thread is guaranteed not to occur until after the
12974 handler for the VM initialization event returns.
12975 <p/>
12976 In the case of VM start-up failure, this event will not be sent.
12977 </description>
12978 <origin>jvmdi</origin>
12979 <capabilities>
12980 </capabilities>
12981 <parameters>
12982 <param id="jni_env">
12983 <outptr>
12984 <struct>JNIEnv</struct>
12985 </outptr>
12986 <description>
12987 The JNI environment of the event (current) thread.
12988 </description>
12989 </param>
12990 <param id="thread">
12991 <jthread/>
12992 <description>
12993 The initial thread
12994 </description>
12995 </param>
12996 </parameters>
12997 </event>
12998
12999 <event label="VM Death Event"
13000 id="VMDeath" const="JVMTI_EVENT_VM_DEATH" num="51">
13001 <description>
13002 The VM death event notifies the agent of the termination of the VM.
13003 No events will occur after the VMDeath event.
13004 <p/>
13005 In the case of VM start-up failure, this event will not be sent.
13006 Note that <internallink id="onunload">Agent_OnUnload</internallink>
13007 will still be called in these cases.
13008 </description>
13009 <origin>jvmdi</origin>
13010 <capabilities>
13011 </capabilities>
13012 <parameters>
13013 <param id="jni_env">
13014 <outptr>
13015 <struct>JNIEnv</struct>
13016 </outptr>
13017 <description>
13018 The JNI environment of the event (current) thread
13019 </description>
13020 </param>
13021 </parameters>
13022 </event>
13023
13024 <event label="Compiled Method Load" phase="start"
13025 id="CompiledMethodLoad" const="JVMTI_EVENT_COMPILED_METHOD_LOAD" num="68">
13026 <description>
13027 Sent when a method is compiled and loaded into memory by the VM.
13028 If it is unloaded, the <eventlink id="CompiledMethodUnload"/> event is sent.
13029 If it is moved, the <eventlink id="CompiledMethodUnload"/> event is sent,
13030 followed by a new <code>CompiledMethodLoad</code> event.
13031 Note that a single method may have multiple compiled forms, and that
13032 this event will be sent for each form.
13033 Note also that several methods may be inlined into a single
13034 address range, and that this event will be sent for each method.
13035 <p/>
13036 These events can be sent after their initial occurrence with
13037 <functionlink id="GenerateEvents"></functionlink>.
13038 </description>
13039 <origin>jvmpi</origin>
13040 <typedef id="jvmtiAddrLocationMap" label="Native address to location entry">
13041 <field id="start_address">
13042 <vmbuf><void/></vmbuf>
13043 <description>
13044 Starting native address of code corresponding to a location
13045 </description>
13046 </field>
13047 <field id="location">
13048 <jlocation/>
13049 <description>
13050 Corresponding location. See
13051 <functionlink id="GetJLocationFormat"></functionlink>
13052 for the meaning of location.
13053 </description>
13054 </field>
13055 </typedef>
13056 <capabilities>
13057 <required id="can_generate_compiled_method_load_events"></required>
13058 </capabilities>
13059 <parameters>
13060 <param id="klass">
13061 <jclass method="method"/>
13062 <description>
13063 Class of the method being compiled and loaded
13064 </description>
13065 </param>
13066 <param id="method">
13067 <jmethodID class="klass"/>
13068 <description>
13069 Method being compiled and loaded
13070 </description>
13071 </param>
13072 <param id="code_size">
13073 <jint/>
13074 <description>
13075 Size of compiled code
13076 </description>
13077 </param>
13078 <param id="code_addr">
13079 <vmbuf><void/></vmbuf>
13080 <description>
13081 Address where compiled method code is loaded
13082 </description>
13083 </param>
13084 <param id="map_length">
13085 <jint/>
13086 <description>
13087 Number of <typelink id="jvmtiAddrLocationMap"></typelink>
13088 entries in the address map.
13089 Zero if mapping information cannot be supplied.
13090 </description>
13091 </param>
13092 <param id="map">
13093 <vmbuf><struct>jvmtiAddrLocationMap</struct></vmbuf>
13094 <description>
13095 Map from native addresses to location.
13096 The native address range of each entry is from
13097 <fieldlink id="start_address" struct="jvmtiAddrLocationMap"></fieldlink>
13098 to <code>start_address-1</code> of the next entry.
13099 <code>NULL</code> if mapping information cannot be supplied.
13100 </description>
13101 </param>
13102 <param id="compile_info">
13103 <vmbuf><void/></vmbuf>
13104 <description>
13105 VM-specific compilation information.
13106 The referenced compile information is managed by the VM
13107 and must not depend on the agent for collection.
13108 A VM implementation defines the content and lifetime
13109 of the information.
13110 </description>
13111 </param>
13112 </parameters>
13113 </event>
13114
13115 <event label="Compiled Method Unload" phase="start"
13116 id="CompiledMethodUnload" const="JVMTI_EVENT_COMPILED_METHOD_UNLOAD" num="69">
13117 <description>
13118 Sent when a compiled method is unloaded from memory.
13119 This event might not be sent on the thread which performed the unload.
13120 This event may be sent sometime after the unload occurs, but
13121 will be sent before the memory is reused
13122 by a newly generated compiled method. This event may be sent after
13123 the class is unloaded.
13124 </description>
13125 <origin>jvmpi</origin>
13126 <capabilities>
13127 <required id="can_generate_compiled_method_load_events"></required>
13128 </capabilities>
13129 <parameters>
13130 <param id="klass">
13131 <jclass method="method"/>
13132 <description>
13133 Class of the compiled method being unloaded.
13134 </description>
13135 </param>
13136 <param id="method">
13137 <jmethodID class="klass"/>
13138 <description>
13139 Compiled method being unloaded.
13140 For identification of the compiled method only -- the class
13141 may be unloaded and therefore the method should not be used
13142 as an argument to further JNI or <jvmti/> functions.
13143 </description>
13144 </param>
13145 <param id="code_addr">
13146 <vmbuf><void/></vmbuf>
13147 <description>
13148 Address where compiled method code was loaded.
13149 For identification of the compiled method only --
13150 the space may have been reclaimed.
13151 </description>
13152 </param>
13153 </parameters>
13154 </event>
13155
13156 <event label="Dynamic Code Generated" phase="any"
13157 id="DynamicCodeGenerated" const="JVMTI_EVENT_DYNAMIC_CODE_GENERATED" num="70">
13158 <description>
13159 Sent when a component of the virtual machine is generated dynamically.
13160 This does not correspond to Java programming language code that is
13161 compiled--see <eventlink id="CompiledMethodLoad"></eventlink>.
13162 This is for native code--for example, an interpreter that is generated
13163 differently depending on command-line options.
13164 <p/>
13165 Note that this event has no controlling capability.
13166 If a VM cannot generate these events, it simply does not send any.
13167 <p/>
13168 These events can be sent after their initial occurrence with
13169 <functionlink id="GenerateEvents"></functionlink>.
13170 </description>
13171 <origin>jvmpi</origin>
13172 <capabilities>
13173 </capabilities>
13174 <parameters>
13175 <param id="name">
13176 <vmbuf><char/></vmbuf>
13177 <description>
13178 Name of the code, encoded as a
13179 <internallink id="mUTF">modified UTF-8</internallink> string.
13180 Intended for display to an end-user.
13181 The name might not be unique.
13182 </description>
13183 </param>
13184 <param id="address">
13185 <vmbuf><void/></vmbuf>
13186 <description>
13187 Native address of the code
13188 </description>
13189 </param>
13190 <param id="length">
13191 <jint/>
13192 <description>
13193 Length in bytes of the code
13194 </description>
13195 </param>
13196 </parameters>
13197 </event>
13198
13199 <event label="Data Dump Request"
13200 id="DataDumpRequest" const="JVMTI_EVENT_DATA_DUMP_REQUEST" num="71">
13201 <description>
13202 Sent by the VM to request the agent to dump its data. This
13203 is just a hint and the agent need not react to this event.
13204 This is useful for processing command-line signals from users. For
13205 example, in the Java 2 SDK a CTRL-Break on Win32 and a CTRL-\ on Solaris
13206 causes the VM to send this event to the agent.
13207 </description>
13208 <origin>jvmpi</origin>
13209 <capabilities>
13210 </capabilities>
13211 <parameters>
13212 </parameters>
13213 </event>
13214
13215 <event label="Monitor Contended Enter"
13216 id="MonitorContendedEnter" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTER" filtered="thread" num="75">
13217 <description>
13218 Sent when a thread is attempting to enter a Java programming language
13219 monitor already acquired by another thread.
13220 </description>
13221 <origin>jvmpi</origin>
13222 <capabilities>
13223 <required id="can_generate_monitor_events"></required>
13224 </capabilities>
13225 <parameters>
13226 <param id="jni_env">
13227 <outptr>
13228 <struct>JNIEnv</struct>
13229 </outptr>
13230 <description>
13231 The JNI environment of the event (current) thread
13232 </description>
13233 </param>
13234 <param id="thread">
13235 <jthread/>
13236 <description>
13237 JNI local reference to the thread
13238 attempting to enter the monitor
13239 </description>
13240 </param>
13241 <param id="object">
13242 <jobject/>
13243 <description>
13244 JNI local reference to the monitor
13245 </description>
13246 </param>
13247 </parameters>
13248 </event>
13249
13250 <event label="Monitor Contended Entered"
13251 id="MonitorContendedEntered" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTERED" filtered="thread" num="76">
13252 <description>
13253 Sent when a thread enters a Java programming language
13254 monitor after waiting for it to be released by another thread.
13255 </description>
13256 <origin>jvmpi</origin>
13257 <capabilities>
13258 <required id="can_generate_monitor_events"></required>
13259 </capabilities>
13260 <parameters>
13261 <param id="jni_env">
13262 <outptr>
13263 <struct>JNIEnv</struct>
13264 </outptr>
13265 <description>
13266 The JNI environment of the event (current) thread
13267 </description>
13268 </param>
13269 <param id="thread">
13270 <jthread/>
13271 <description>
13272 JNI local reference to the thread entering
13273 the monitor
13274 </description>
13275 </param>
13276 <param id="object">
13277 <jobject/>
13278 <description>
13279 JNI local reference to the monitor
13280 </description>
13281 </param>
13282 </parameters>
13283 </event>
13284
13285 <event label="Monitor Wait"
13286 id="MonitorWait" const="JVMTI_EVENT_MONITOR_WAIT" filtered="thread" num="73">
13287 <description>
13288 Sent when a thread is about to wait on an object.
13289 </description>
13290 <origin>jvmpi</origin>
13291 <capabilities>
13292 <required id="can_generate_monitor_events"></required>
13293 </capabilities>
13294 <parameters>
13295 <param id="jni_env">
13296 <outptr>
13297 <struct>JNIEnv</struct>
13298 </outptr>
13299 <description>
13300 The JNI environment of the event (current) thread
13301 </description>
13302 </param>
13303 <param id="thread">
13304 <jthread/>
13305 <description>
13306 JNI local reference to the thread about to wait
13307 </description>
13308 </param>
13309 <param id="object">
13310 <jobject/>
13311 <description>
13312 JNI local reference to the monitor
13313 </description>
13314 </param>
13315 <param id="timeout">
13316 <jlong/>
13317 <description>
13318 The number of milliseconds the thread will wait
13319 </description>
13320 </param>
13321 </parameters>
13322 </event>
13323
13324 <event label="Monitor Waited"
13325 id="MonitorWaited" const="JVMTI_EVENT_MONITOR_WAITED" filtered="thread" num="74">
13326 <description>
13327 Sent when a thread finishes waiting on an object.
13328 </description>
13329 <origin>jvmpi</origin>
13330 <capabilities>
13331 <required id="can_generate_monitor_events"></required>
13332 </capabilities>
13333 <parameters>
13334 <param id="jni_env">
13335 <outptr>
13336 <struct>JNIEnv</struct>
13337 </outptr>
13338 <description>
13339 The JNI environment of the event (current) thread
13340 </description>
13341 </param>
13342 <param id="thread">
13343 <jthread/>
13344 <description>
13345 JNI local reference to the thread that was finished waiting
13346 </description>
13347 </param>
13348 <param id="object">
13349 <jobject/>
13350 <description>
13351 JNI local reference to the monitor.
13352 </description>
13353 </param>
13354 <param id="timed_out">
13355 <jboolean/>
13356 <description>
13357 True if the monitor timed out
13358 </description>
13359 </param>
13360 </parameters>
13361 </event>
13362
13363 <event label="Resource Exhausted"
13364 id="ResourceExhausted" const="JVMTI_EVENT_RESOURCE_EXHAUSTED" num="80"
13365 since="1.1">
13366 <description>
13367 Sent when a VM resource needed by a running application has been exhausted.
13368 Except as required by the optional capabilities, the set of resources
13369 which report exhaustion is implementation dependent.
13370 <p/>
13371 The following bit flags define the properties of the resource exhaustion:
13372 <constants id="jvmtiResourceExhaustionFlags"
13373 label="Resource Exhaustion Flags"
13374 kind="bits"
13375 since="1.1">
13376 <constant id="JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR" num="0x0001">
13377 After this event returns, the VM will throw a
13378 <code>java.lang.OutOfMemoryError</code>.
13379 </constant>
13380 <constant id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP" num="0x0002">
13381 The VM was unable to allocate memory from the <tm>Java</tm>
13382 platform <i>heap</i>.
13383 The <i>heap</i> is the runtime
13384 data area from which memory for all class instances and
13385 arrays are allocated.
13386 </constant>
13387 <constant id="JVMTI_RESOURCE_EXHAUSTED_THREADS" num="0x0004">
13388 The VM was unable to create a thread.
13389 </constant>
13390 </constants>
13391 </description>
13392 <origin>new</origin>
13393 <capabilities>
13394 <capability id="can_generate_resource_exhaustion_heap_events">
13395 Can generate events when the VM is unable to allocate memory from the
13396 <internallink id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP">heap</internallink>.
13397 </capability>
13398 <capability id="can_generate_resource_exhaustion_threads_events">
13399 Can generate events when the VM is unable to
13400 <internallink id="JVMTI_RESOURCE_EXHAUSTED_THREADS">create
13401 a thread</internallink>.
13402 </capability>
13403 </capabilities>
13404 <parameters>
13405 <param id="jni_env">
13406 <outptr>
13407 <struct>JNIEnv</struct>
13408 </outptr>
13409 <description>
13410 The JNI environment of the event (current) thread
13411 </description>
13412 </param>
13413 <param id="flags">
13414 <jint/>
13415 <description>
13416 Flags defining the properties of the of resource exhaustion
13417 as specified by the
13418 <internallink id="jvmtiResourceExhaustionFlags">Resource
13419 Exhaustion Flags</internallink>.
13420 </description>
13421 </param>
13422 <param id="reserved">
13423 <vmbuf><void/></vmbuf>
13424 <description>
13425 Reserved.
13426 </description>
13427 </param>
13428 <param id="description">
13429 <vmbuf><char/></vmbuf>
13430 <description>
13431 Description of the resource exhaustion, encoded as a
13432 <internallink id="mUTF">modified UTF-8</internallink> string.
13433 </description>
13434 </param>
13435 </parameters>
13436 </event>
13437
13438 <event label="VM Object Allocation"
13439 id="VMObjectAlloc" const="JVMTI_EVENT_VM_OBJECT_ALLOC" num="84">
13440 <description>
13441 Sent when a method causes the virtual machine to allocate an
13442 Object visible to Java programming language code and the
13443 allocation is not detectable by other intrumentation mechanisms.
13444 Generally object allocation should be detected by instrumenting
13445 the bytecodes of allocating methods.
13446 Object allocation generated in native code by JNI function
13447 calls should be detected using
13448 <internallink id="jniIntercept">JNI function interception</internallink>.
13449 Some methods might not have associated bytecodes and are not
13450 native methods, they instead are executed directly by the
13451 VM. These methods should send this event.
13452 Virtual machines which are incapable of bytecode instrumentation
13453 for some or all of their methods can send this event.
13454 <p/>
13455 Typical examples where this event might be sent:
13456 <ul>
13457 <li>Reflection -- for example, <code>java.lang.Class.newInstance()</code></li>
13458 <li>Methods not represented by bytecodes -- for example, VM intrinsics and
13459 J2ME preloaded classes</li>
13460 </ul>
13461 Cases where this event would not be generated:
13462 <ul>
13463 <li>Allocation due to bytecodes -- for example, the <code>new</code>
13464 and <code>newarray</code> VM instructions</li>
13465 <li>Allocation due to JNI function calls -- for example,
13466 <code>AllocObject</code></li>
13467 <li>Allocations during VM initialization</li>
13468 <li>VM internal objects</li>
13469 </ul>
13470 </description>
13471 <origin>new</origin>
13472 <capabilities>
13473 <required id="can_generate_vm_object_alloc_events"></required>
13474 </capabilities>
13475 <parameters>
13476 <param id="jni_env">
13477 <outptr>
13478 <struct>JNIEnv</struct>
13479 </outptr>
13480 <description>
13481 The JNI environment of the event (current) thread
13482 </description>
13483 </param>
13484 <param id="thread">
13485 <jthread/>
13486 <description>
13487 Thread allocating the object.
13488 </description>
13489 </param>
13490 <param id="object">
13491 <jobject/>
13492 <description>
13493 JNI local reference to the object that was allocated
13494 </description>
13495 </param>
13496 <param id="object_klass">
13497 <jclass/>
13498 <description>
13499 JNI local reference to the class of the object
13500 </description>
13501 </param>
13502 <param id="size">
13503 <jlong/>
13504 <description>
13505 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
13506 </description>
13507 </param>
13508 </parameters>
13509 </event>
13510
13511 <event label="Object Free"
13512 id="ObjectFree" const="JVMTI_EVENT_OBJECT_FREE" num="83">
13513 <description>
13514 An Object Free event is sent when the garbage collector frees an object.
13515 Events are only sent for tagged objects--see
13516 <internallink id="Heap">heap functions</internallink>.
13517 <p/>
13518 The event handler must not use JNI functions and
13519 must not use <jvmti/> functions except those which
13520 specifically allow such use (see the raw monitor, memory management,
13521 and environment local storage functions).
13522 </description>
13523 <origin>new</origin>
13524 <capabilities>
13525 <required id="can_generate_object_free_events"></required>
13526 </capabilities>
13527 <parameters>
13528 <param id="tag">
13529 <jlong/>
13530 <description>
13531 The freed object's tag
13532 </description>
13533 </param>
13534 </parameters>
13535 </event>
13536
13537 <event label="Garbage Collection Start"
13538 id="GarbageCollectionStart" const="JVMTI_EVENT_GARBAGE_COLLECTION_START" num="81">
13539 <description>
13540 A Garbage Collection Start event is sent when a
13541 garbage collection pause begins.
13542 Only stop-the-world collections are reported--that is, collections during
13543 which all threads cease to modify the state of the Java virtual machine.
13544 This means that some collectors will never generate these events.
13545 This event is sent while the VM is still stopped, thus
13546 the event handler must not use JNI functions and
13547 must not use <jvmti/> functions except those which
13548 specifically allow such use (see the raw monitor, memory management,
13549 and environment local storage functions).
13550 <p/>
13551 This event is always sent as a matched pair with
13552 <eventlink id="GarbageCollectionFinish"/>
13553 (assuming both events are enabled) and no garbage collection
13554 events will occur between them.
13555 </description>
13556 <origin>new</origin>
13557 <capabilities>
13558 <required id="can_generate_garbage_collection_events"></required>
13559 </capabilities>
13560 <parameters>
13561 </parameters>
13562 </event>
13563
13564 <event label="Garbage Collection Finish"
13565 id="GarbageCollectionFinish" const="JVMTI_EVENT_GARBAGE_COLLECTION_FINISH" num="82">
13566 <description>
13567 A Garbage Collection Finish event is sent when a
13568 garbage collection pause ends.
13569 This event is sent while the VM is still stopped, thus
13570 the event handler must not use JNI functions and
13571 must not use <jvmti/> functions except those which
13572 specifically allow such use (see the raw monitor, memory management,
13573 and environment local storage functions).
13574 <p/>
13575 Some agents may need to do post garbage collection operations that
13576 require the use of the disallowed <jvmti/> or JNI functions. For these
13577 cases an agent thread can be created which waits on a raw monitor,
13578 and the handler for the Garbage Collection Finish event simply
13579 notifies the raw monitor
13580 <p/>
13581 This event is always sent as a matched pair with
13582 <eventlink id="GarbageCollectionStart"/> (assuming both events are enabled).
13583 <issue>
13584 The most important use of this event is to provide timing information,
13585 and thus additional information is not required. However,
13586 information about the collection which is "free" should be included -
13587 what that information is needs to be determined.
13588 </issue>
13589 </description>
13590 <origin>new</origin>
13591 <capabilities>
13592 <required id="can_generate_garbage_collection_events"></required>
13593 </capabilities>
13594 <parameters>
13595 </parameters>
13596 </event>
13597
13598 <elide>
13599 <event label="Verbose Output" phase="any"
13600 id="VerboseOutput" const="JVMTI_EVENT_VERBOSE_OUTPUT" num="85">
13601 <description>
13602 Send verbose messages as strings.
13603 <issue>
13604 This format is extremely fragile, as it can change with each
13605 platform, collector and version. Alternatives include:
13606 <ul>
13607 <li>building off Java programming language M and M APIs</li>
13608 <li>XML</li>
13609 <li>key/value pairs</li>
13610 <li>removing it</li>
13611 </ul>
13612 </issue>
13613 <issue>
13614 Though this seemed trivial to implement.
13615 In the RI it appears this will be quite complex.
13616 </issue>
13617 </description>
13618 <origin>new</origin>
13619 <capabilities>
13620 </capabilities>
13621 <parameters>
13622 <param id="flag">
13623 <enum>jvmtiVerboseFlag</enum>
13624 <description>
13625 Which verbose output is being sent.
13626 </description>
13627 </param>
13628 <param id="message">
13629 <vmbuf><char/></vmbuf>
13630 <description>
13631 Message text, encoded as a
13632 <internallink id="mUTF">modified UTF-8</internallink> string.
13633 </description>
13634 </param>
13635 </parameters>
13636 </event>
13637 </elide>
13638
13639 </eventsection>
13640
13641 <datasection>
13642 <intro>
13643 <jvmti/> extends the data types defined by JNI.
13644 </intro>
13645 <basetypes id="jniTypes" label="JNI Types Used in the JVM Tool Interface">
13646 <basetype id="jboolean">
13647 <description>
13648 Holds a Java programming language <code>boolean</code>.
13649 Unsigned 8 bits.
13650 </description>
13651 </basetype>
13652 <basetype id="jchar">
13653 <description>
13654 Holds a Java programming language <code>char</code>.
13655 Unsigned 16 bits.
13656 </description>
13657 </basetype>
13658 <basetype id="jint">
13659 <description>
13660 Holds a Java programming language <code>int</code>.
13661 Signed 32 bits.
13662 </description>
13663 </basetype>
13664 <basetype id="jlong">
13665 <description>
13666 Holds a Java programming language <code>long</code>.
13667 Signed 64 bits.
13668 </description>
13669 </basetype>
13670 <basetype id="jfloat">
13671 <description>
13672 Holds a Java programming language <code>float</code>.
13673 32 bits.
13674 </description>
13675 </basetype>
13676 <basetype id="jdouble">
13677 <description>
13678 Holds a Java programming language <code>double</code>.
13679 64 bits.
13680 </description>
13681 </basetype>
13682 <basetype id="jobject">
13683 <description>
13684 Holds a Java programming language object.
13685 </description>
13686 </basetype>
13687 <basetype id="jclass">
13688 <description>
13689 Holds a Java programming language class.
13690 </description>
13691 </basetype>
13692 <basetype id="jvalue">
13693 <description>
13694 Is a union of all primitive types and <code>jobject</code>. Thus, holds any Java
13695 programming language value.
13696 </description>
13697 </basetype>
13698 <basetype id="jfieldID">
13699 <description>
13700 Identifies a Java programming language field.
13701 <code>jfieldID</code>s returned by <jvmti/> functions and events may be
13702 safely stored.
13703 </description>
13704 </basetype>
13705 <basetype id="jmethodID">
13706 <description>
13707 Identifies a Java programming language method, initializer, or constructor.
13708 <code>jmethodID</code>s returned by <jvmti/> functions and events may be
13709 safely stored. However, if the class is unloaded, they become invalid
13710 and must not be used.
13711 </description>
13712 </basetype>
13713 <basetype id="JNIEnv">
13714 <description>
13715 Pointer to the JNI function table. Pointer to this (<code>JNIEnv *</code>)
13716 is a JNI environment.
13717 </description>
13718 </basetype>
13719 </basetypes>
13720
13721 <basetypes id="jvmtiTypes" label="JVM Tool Interface Base Types">
13722 <basetype id="jvmtiEnv">
13723 <description>
13724 The <jvmti/> <internallink id="environments">environment</internallink> pointer.
13725 See the <internallink id="FunctionSection">Function Section</internallink>.
13726 <code>jvmtiEnv</code> points to the
13727 <internallink id="FunctionTable">function table</internallink> pointer.
13728 </description>
13729 </basetype>
13730 <basetype id="jthread">
13731 <definition>typedef jobject jthread;</definition>
13732 <description>
13733 Subtype of <datalink id="jobject"></datalink> that holds a thread.
13734 </description>
13735 </basetype>
13736 <basetype id="jthreadGroup">
13737 <definition>typedef jobject jthreadGroup;</definition>
13738 <description>
13739 Subtype of <datalink id="jobject"></datalink> that holds a thread group.
13740 </description>
13741 </basetype>
13742 <basetype id="jlocation">
13743 <definition>typedef jlong jlocation;</definition>
13744 <description>
13745 A 64 bit value, representing a monotonically increasing
13746 executable position within a method.
13747 <code>-1</code> indicates a native method.
13748 See <functionlink id="GetJLocationFormat"></functionlink> for the format on a
13749 given VM.
13750 </description>
13751 </basetype>
13752 <basetype id="jrawMonitorID">
13753 <definition>struct _jrawMonitorID;
13754 typedef struct _jrawMonitorID *jrawMonitorID;</definition>
13755 <description>
13756 A raw monitor.
13757 </description>
13758 </basetype>
13759 <basetype id="jvmtiError">
13760 <description>
13761 Holds an error return code.
13762 See the <internallink id="ErrorSection">Error section</internallink> for possible values.
13763 <example>
13764 typedef enum {
13765 JVMTI_ERROR_NONE = 0,
13766 JVMTI_ERROR_INVALID_THREAD = 10,
13767 ...
13768 } jvmtiError;
13769 </example>
13770 </description>
13771 </basetype>
13772 <basetype id="jvmtiEvent">
13773 <description>
13774 An identifier for an event type.
13775 See the <internallink id="EventSection">Event section</internallink> for possible values.
13776 It is guaranteed that future versions of this specification will
13777 never assign zero as an event type identifier.
13778 <example>
13779 typedef enum {
13780 JVMTI_EVENT_SINGLE_STEP = 1,
13781 JVMTI_EVENT_BREAKPOINT = 2,
13782 ...
13783 } jvmtiEvent;
13784 </example>
13785 </description>
13786 </basetype>
13787 <basetype id="jvmtiEventCallbacks">
13788 <description>
13789 The callbacks used for events.
13790 <example>
13791 typedef struct {
13792 jvmtiEventVMInit VMInit;
13793 jvmtiEventVMDeath VMDeath;
13794 ...
13795 } jvmtiEventCallbacks;
13796 </example>
13797 See <internallink id="jvmtiEventCallbacks">event callbacks</internallink>
13798 for the complete structure.
13799 <p/>
13800 Where, for example, the VM initialization callback is defined:
13801 <example>
13802 typedef void (JNICALL *jvmtiEventVMInit)
13803 (jvmtiEnv *jvmti_env,
13804 JNIEnv* jni_env,
13805 jthread thread);
13806 </example>
13807 See the individual events for the callback function definition.
13808 </description>
13809 </basetype>
13810 <basetype id="jniNativeInterface">
13811 <definition>typedef struct JNINativeInterface_ jniNativeInterface;</definition>
13812 <description>
13813 Typedef for the JNI function table <code>JNINativeInterface</code>
13814 defined in the
13815 <externallink id="docs/technotes/guides/jni/spec/functions.html#interface_function_table">
13816 JNI Specification</externallink>.
13817 The JNI reference implementation defines this with an underscore.
13818 </description>
13819 </basetype>
13820 </basetypes>
13821
13822 </datasection>
13823
13824 <issuessection label="Issues">
13825 <intro id="suspendRequired" label="Resolved Issue: Suspend - Required or Automatic">
13826 JVMDI requires that the agent suspend threads before calling
13827 certain sensitive functions. JVMPI requires garbage collection to be
13828 disabled before calling certain sensitive functions.
13829 It was suggested that rather than have this requirement, that
13830 VM place itself in a suitable state before performing an
13831 operation. This makes considerable sense since each VM
13832 knows its requirements and can most easily arrange a
13833 safe state.
13834 <p/>
13835 The ability to externally suspend/resume threads will, of
13836 course, remain. The ability to enable/disable garbage collection will not.
13837 <p/>
13838 This issue is resolved--suspend will not
13839 be required. The spec has been updated to reflect this.
13840 </intro>
13841
13842 <intro id="stackSampling" label="Resolved Issue: Call Stack Sampling">
13843 There are a variety of approaches to sampling call stacks.
13844 The biggest bifurcation is between VM controlled and agent
13845 controlled.
13846 <p/>
13847 This issue is resolved--agent controlled
13848 sampling will be the approach.
13849 </intro>
13850
13851 <intro id="threadRepresentation" label="Resolved Issue: Thread Representation">
13852 JVMDI represents threads as jthread. JVMPI primarily
13853 uses JNIEnv* to represent threads.
13854 <p/>
13855 The Expert Group has chosen jthread as the representation
13856 for threads in <jvmti/>.
13857 JNIEnv* is sent by
13858 events since it is needed to JNI functions. JNIEnv, per the
13859 JNI spec, are not supposed to be used outside their thread.
13860 </intro>
13861
13862 <intro id="design" label="Resolved Issue: Method Representation">
13863 The JNI spec allows an implementation to depend on jclass/jmethodID
13864 pairs, rather than simply a jmethodID, to reference a method.
13865 JVMDI, for consistency, choose the same representation.
13866 JVMPI, however, specifies that a jmethodID alone maps to a
13867 method. Both of the Sun <tm>J2SE</tm> virtual machines (Classic and <tm>HotSpot</tm>) store
13868 pointers in jmethodIDs, and as a result, a jmethodID is sufficient.
13869 In fact, any JVM implementation that supports JVMPI must have
13870 such a representation.
13871 <jvmti/> will use jmethodID as a unique representation of a method
13872 (no jclass is used).
13873 There should be efficiency gains, particularly in
13874 functionality like stack dumping, to this representation.
13875 <p/>
13876 Note that fields were not used in JVMPI and that the access profile
13877 of fields differs from methods--for implementation efficiency
13878 reasons, a jclass/jfieldID pair will still be needed for field
13879 reference.
13880 </intro>
13881
13882 <intro id="localReferenceIssue" label="Resolved Issue: Local References">
13883 Functions return local references.
13884 </intro>
13885
13886 <intro id="frameRep" label="Resolved Issue: Representation of frames">
13887 In JVMDI, a frame ID is used to represent a frame. Problem with this
13888 is that a VM must track when a frame becomes invalid, a far better
13889 approach, and the one used in <jvmti/>, is to reference frames by depth.
13890 </intro>
13891
13892 <intro id="requiredCapabilities" label="Issue: Required Capabilities">
13893 Currently, having a required capabilities means that the functionality
13894 is optional. Capabilities are useful even for required functionality
13895 since they can inform the VM is needed set-up. Thus, there should be
13896 a set of capabilities that a conformant implementation must provide
13897 (if requested during Agent_OnLoad).
13898 </intro>
13899
13900 <intro id="taghint" label="Proposal: add tag hint function">
13901 A hint of the percentage of objects that will be tagged would
13902 help the VM pick a good implementation.
13903 </intro>
13904
13905 <intro id="moreMonitorQueries" label="Request: More Monitor Quires">
13906 How difficult or easy would be to extend the monitor_info category to include
13907 <pre>
13908 - current number of monitors
13909 - enumeration of monitors
13910 - enumeration of threads waiting on a given monitor
13911 </pre>
13912 The reason for my question is the fact that current get_monitor_info support
13913 requires the agent to specify a given thread to get the info which is probably
13914 OK in the profiling/debugging space, while in the monitoring space the agent
13915 could be watching the monitor list and then decide which thread to ask for
13916 the info. You might ask why is this important for monitoring .... I think it
13917 can aid in the detection/prediction of application contention caused by hot-locks.
13918 </intro>
13919 </issuessection>
13920
13921 <changehistory id="ChangeHistory" update="09/05/07">
13922 <intro>
13923 The <jvmti/> specification is an evolving document with major, minor,
13924 and micro version numbers.
13925 A released version of the specification is uniquely identified
13926 by its major and minor version.
13927 The functions, events, and capabilities in this specification
13928 indicate a "Since" value which is the major and minor version in
13929 which it was introduced.
13930 The version of the specification implemented by the VM can
13931 be retrieved at runtime with the <functionlink id="GetVersionNumber"/>
13932 function.
13933 </intro>
13934 <change date="14 Nov 2002">
13935 Converted to XML document.
13936 </change>
13937 <change date="14 Nov 2002">
13938 Elided heap dump functions (for now) since what was there
13939 was wrong.
13940 </change>
13941 <change date="18 Nov 2002">
13942 Added detail throughout.
13943 </change>
13944 <change date="18 Nov 2002">
13945 Changed JVMTI_THREAD_STATUS_RUNNING to JVMTI_THREAD_STATUS_RUNNABLE.
13946 </change>
13947 <change date="19 Nov 2002">
13948 Added AsyncGetStackTrace.
13949 </change>
13950 <change date="19 Nov 2002">
13951 Added jframeID return to GetStackTrace.
13952 </change>
13953 <change date="19 Nov 2002">
13954 Elided GetCurrentFrame and GetCallingFrame functions (for now) since what was there
13955 since they are redundant with GetStackTrace.
13956 </change>
13957 <change date="19 Nov 2002">
13958 Elided ClearAllBreakpoints since it has always been redundant.
13959 </change>
13960 <change date="19 Nov 2002">
13961 Added GetSystemProperties.
13962 </change>
13963 <change date="19 Nov 2002">
13964 Changed the thread local storage functions to use jthread.
13965 </change>
13966 <change date="20 Nov 2002">
13967 Added GetJLocationFormat.
13968 </change>
13969 <change date="22 Nov 2002">
13970 Added events and introductory text.
13971 </change>
13972 <change date="22 Nov 2002">
13973 Cross reference type and constant definitions.
13974 </change>
13975 <change date="24 Nov 2002">
13976 Added DTD.
13977 </change>
13978 <change date="24 Nov 2002">
13979 Added capabilities function section.
13980 </change>
13981 <change date="29 Nov 2002">
13982 Assign capabilities to each function and event.
13983 </change>
13984 <change date="29 Nov 2002">
13985 Add <internallink id="jniIntercept">JNI interception functions</internallink>.
13986 </change>
13987 <change date="30 Nov 2002">
13988 Auto generate SetEventNotificationMode capabilities.
13989 </change>
13990 <change date="30 Nov 2002">
13991 Add <eventlink id="VMObjectAlloc"></eventlink> event.
13992 </change>
13993 <change date="30 Nov 2002">
13994 Add <eventlink id="DynamicCodeGenerated"></eventlink> event.
13995 </change>
13996 <change date="30 Nov 2002">
13997 Add const to declarations.
13998 </change>
13999 <change date="30 Nov 2002">
14000 Change method exit and frame pop to send on exception.
14001 </change>
14002 <change date="1 Dec 2002">
14003 Add ForceGarbageCollection.
14004 </change>
14005 <change date="2 Dec 2002">
14006 Redo Xrun section; clarify GetStackTrace and add example;
14007 Fix width problems; use "agent" consistently.
14008 </change>
14009 <change date="8 Dec 2002">
14010 Remove previous start-up intro.
14011 Add <internallink id="environments"><jvmti/> Environments</internallink>
14012 section.
14013 </change>
14014 <change date="8 Dec 2002">
14015 Add <functionlink id="DisposeEnvironment"></functionlink>.
14016 </change>
14017 <change date="9 Dec 2002">
14018 Numerous minor updates.
14019 </change>
14020 <change date="15 Dec 2002">
14021 Add heap profiling functions added:
14022 get/set annotation, iterate live objects/heap.
14023 Add heap profiling functions place holder added:
14024 heap roots.
14025 Heap profiling event added: object free.
14026 Heap profiling event redesigned: vm object allocation.
14027 Heap profiling event placeholders added: garbage collection start/finish.
14028 Native method bind event added.
14029 </change>
14030 <change date="19 Dec 2002">
14031 Revamp suspend/resume functions.
14032 Add origin information with jvmdi tag.
14033 Misc fixes.
14034 </change>
14035 <change date="24 Dec 2002">
14036 Add semantics to types.
14037 </change>
14038 <change date="27 Dec 2002">
14039 Add local reference section.
14040 Autogenerate parameter descriptions from types.
14041 </change>
14042 <change date="28 Dec 2002">
14043 Document that RunAgentThread sends threadStart.
14044 </change>
14045 <change date="29 Dec 2002">
14046 Remove redundant local ref and dealloc warning.
14047 Convert GetRawMonitorName to allocated buffer.
14048 Add GenerateEvents.
14049 </change>
14050 <change date="30 Dec 2002">
14051 Make raw monitors a type and rename to "jrawMonitorID".
14052 </change>
14053 <change date="1 Jan 2003">
14054 Include origin information.
14055 Clean-up JVMDI issue references.
14056 Remove Deallocate warnings which are now automatically generated.
14057 </change>
14058 <change date="2 Jan 2003">
14059 Fix representation issues for jthread.
14060 </change>
14061 <change date="3 Jan 2003">
14062 Make capabilities buffered out to 64 bits - and do it automatically.
14063 </change>
14064 <change date="4 Jan 2003">
14065 Make constants which are enumeration into enum types.
14066 Parameters now of enum type.
14067 Clean-up and index type section.
14068 Replace remaining datadef entities with callback.
14069 </change>
14070 <change date="7 Jan 2003">
14071 Correct GenerateEvents description.
14072 More internal semantics work.
14073 </change>
14074 <change date="9 Jan 2003">
14075 Replace previous GetSystemProperties with two functions
14076 which use allocated information instead fixed.
14077 Add SetSystemProperty.
14078 More internal semantics work.
14079 </change>
14080 <change date="12 Jan 2003">
14081 Add varargs to end of SetEventNotificationMode.
14082 </change>
14083 <change date="20 Jan 2003">
14084 Finish fixing spec to reflect that alloc sizes are jlong.
14085 </change>
14086 <change date="22 Jan 2003">
14087 Allow NULL as RunAgentThread arg.
14088 </change>
14089 <change date="22 Jan 2003">
14090 Fixed names to standardized naming convention
14091 Removed AsyncGetStackTrace.
14092 </change>
14093 <change date="29 Jan 2003">
14094 Since we are using jthread, removed GetThread.
14095 </change>
14096 <change date="31 Jan 2003">
14097 Change GetFieldName to allow NULLs like GetMethodName.
14098 </change>
14099 <change date="29 Feb 2003" version="v40">
14100 Rewrite the introductory text, adding sections on
14101 start-up, environments and bytecode instrumentation.
14102 Change the command line arguments per EG discussions.
14103 Add an introduction to the capabilities section.
14104 Add the extension mechanism category and functions.
14105 Mark for deletion, but clarified anyhow, SuspendAllThreads.
14106 Rename IterateOverLiveObjects to IterateOverReachableObjects and
14107 change the text accordingly.
14108 Clarify IterateOverHeap.
14109 Clarify CompiledMethodLoad.
14110 Discuss prerequisite state for Calling Functions.
14111 Clarify SetAllocationHooks.
14112 Added issues ("To be resolved:") through-out.
14113 And so on...
14114 </change>
14115 <change date="6 Mar 2003" version="v41">
14116 Remove struct from the call to GetOwnedMonitorInfo.
14117 Automatically generate most error documentation, remove
14118 (rather broken) hand written error doc.
14119 Better describe capability use (empty initial set).
14120 Add min value to jint params.
14121 Remove the capability can_access_thread_local_storage.
14122 Rename error JVMTI_ERROR_NOT_IMPLEMENTED to JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
14123 same for *NOT_IMPLEMENTED.
14124 Description fixes.
14125 </change>
14126 <change date="8 Mar 2003" version="v42">
14127 Rename GetClassSignature to GetClassName.
14128 Rename IterateOverClassObjects to IterateOverInstancesOfClass.
14129 Remove GetMaxStack (operand stack isn't used in <jvmti/>).
14130 Description fixes: define launch-time, remove native frame pop
14131 from PopFrame, and assorted clarifications.
14132 </change>
14133 <change date="8 Mar 2003" version="v43">
14134 Fix minor editing problem.
14135 </change>
14136 <change date="10 Mar 2003" version="v44">
14137 Add phase information.
14138 Remap (compact) event numbers.
14139 </change>
14140 <change date="11 Mar 2003" version="v45">
14141 More phase information - allow "any".
14142 Elide raw monitor queries and events.
14143 Minor description fixes.
14144 </change>
14145 <change date="12 Mar 2003" version="v46">
14146 Add GetPhase.
14147 Use "phase" through document.
14148 Elide GetRawMonitorName.
14149 Elide GetObjectMonitors.
14150 </change>
14151 <change date="12 Mar 2003" version="v47">
14152 Fixes from link, XML, and spell checking.
14153 Auto-generate the callback structure.
14154 </change>
14155 <change date="13 Mar 2003" version="v48">
14156 One character XML fix.
14157 </change>
14158 <change date="13 Mar 2003" version="v49">
14159 Change function parameter names to be consistent with
14160 event parameters (fooBarBaz becomes foo_bar_baz).
14161 </change>
14162 <change date="14 Mar 2003" version="v50">
14163 Fix broken link. Fix thread markers.
14164 </change>
14165 <change date="14 Mar 2003" version="v51">
14166 Change constants so they are under 128 to workaround
14167 compiler problems.
14168 </change>
14169 <change date="23 Mar 2003" version="v52">
14170 Overhaul capabilities. Separate GetStackTrace into
14171 GetStackTrace and GetStackFrames.
14172 </change>
14173 <change date="8 Apr 2003" version="v54">
14174 Use depth instead of jframeID to reference frames.
14175 Remove the now irrelevant GetCurrentFrame, GetCallerFrame and GetStackFrames.
14176 Remove frame arg from events.
14177 </change>
14178 <change date="9 Apr 2003" version="v55">
14179 Remove GetObjectWithAnnotation since tests show bufferred approach more efficient.
14180 Add missing annotation_count to GetObjectsWithAnnotations
14181 </change>
14182 <change date="10 Apr 2003" version="v56">
14183 Remove confusing parenthetical statement in GetObjectsWithAnnotations
14184 </change>
14185 <change date="13 Apr 2003" version="v58">
14186 Replace jclass/jmethodID representation of method with simply jmethodID;
14187 Pass JvmtiEnv* as first arg of every event; remove JNIEnv* where inappropriate.
14188 Replace can_access_frames with can_access_local_variables; remove from purely stack access.
14189 Use can_get_synthetic_attribute; fix description.
14190 Clarify that zero length arrays must be deallocated.
14191 Clarify RelinquishCapabilities.
14192 Generalize JVMTI_ERROR_VM_DEAD to JVMTI_ERROR_WRONG_PHASE.
14193 </change>
14194 <change date="27 Apr 2003" version="v59">
14195 Remove lingering indirect references to OBSOLETE_METHOD_ID.
14196 </change>
14197 <change date="4 May 2003" version="v60">
14198 Allow DestroyRawMonitor during OnLoad.
14199 </change>
14200 <change date="7 May 2003" version="v61">
14201 Added not monitor owner error return to DestroyRawMonitor.
14202 </change>
14203 <change date="13 May 2003" version="v62">
14204 Clarify semantics of raw monitors.
14205 Change flags on <code>GetThreadStatus</code>.
14206 <code>GetClassLoader</code> return NULL for the bootstrap class loader.
14207 Add <code>GetClassName</code> issue.
14208 Define local variable signature.
14209 Disallow zero in annotations array of <code>GetObjectsWithAnnotations</code>.
14210 Remove over specification in <code>GetObjectsWithAnnotations</code>.
14211 Elide <code>SetAllocationHooks</code>.
14212 Elide <code>SuspendAllThreads</code>.
14213 </change>
14214 <change date="14 May 2003" version="v63">
14215 Define the data type <code>jvmtiEventCallbacks</code>.
14216 Zero length allocations return NULL.
14217 Keep SetAllocationHooks in JVMDI, but remove from <jvmti/>.
14218 Add JVMTI_THREAD_STATUS_FLAG_INTERRUPTED.
14219 </change>
14220 <change date="15 May 2003" version="v64">
14221 Better wording, per review.
14222 </change>
14223 <change date="15 May 2003" version="v65">
14224 First Alpha.
14225 Make jmethodID and jfieldID unique, jclass not used.
14226 </change>
14227 <change date="27 May 2003" version="v66">
14228 Fix minor XSLT errors.
14229 </change>
14230 <change date="13 June 2003" version="v67">
14231 Undo making jfieldID unique (jmethodID still is).
14232 </change>
14233 <change date="17 June 2003" version="v68">
14234 Changes per June 11th Expert Group meeting --
14235 Overhaul Heap functionality: single callback,
14236 remove GetHeapRoots, add reachable iterators,
14237 and rename "annotation" to "tag".
14238 NULL thread parameter on most functions is current
14239 thread.
14240 Add timers.
14241 Remove ForceExit.
14242 Add GetEnvironmentLocalStorage.
14243 Add verbose flag and event.
14244 Add AddToBootstrapClassLoaderSearch.
14245 Update ClassFileLoadHook.
14246 </change>
14247 <change date="18 June 2003" version="v69">
14248 Clean up issues sections.
14249 Rename GetClassName back to GetClassSignature and
14250 fix description.
14251 Add generic signature to GetClassSignature,
14252 GetFieldSignature, GetMethodSignature, and
14253 GetLocalVariableTable.
14254 Elide EstimateCostOfCapabilities.
14255 Clarify that the system property functions operate
14256 on the VM view of system properties.
14257 Clarify Agent_OnLoad.
14258 Remove "const" from JNIEnv* in events.
14259 Add metadata accessors.
14260 </change>
14261 <change date="18 June 2003" version="v70">
14262 Add start_depth to GetStackTrace.
14263 Move system properties to a new category.
14264 Add GetObjectSize.
14265 Remove "X" from command line flags.
14266 XML, HTML, and spell check corrections.
14267 </change>
14268 <change date="19 June 2003" version="v71">
14269 Fix JVMTI_HEAP_ROOT_THREAD to be 6.
14270 Make each synopsis match the function name.
14271 Fix unclear wording.
14272 </change>
14273 <change date="26 June 2003" version="v72">
14274 SetThreadLocalStorage and SetEnvironmentLocalStorage should allow value
14275 to be set to NULL.
14276 NotifyFramePop, GetFrameLocationm and all the local variable operations
14277 needed to have their wording about frames fixed.
14278 Grammar and clarity need to be fixed throughout.
14279 Capitalization and puntuation need to be consistent.
14280 Need micro version number and masks for accessing major, minor, and micro.
14281 The error code lists should indicate which must be returned by
14282 an implementation.
14283 The command line properties should be visible in the properties functions.
14284 Disallow popping from the current thread.
14285 Allow implementations to return opaque frame error when they cannot pop.
14286 The NativeMethodBind event should be sent during any phase.
14287 The DynamicCodeGenerated event should be sent during any phase.
14288 The following functions should be allowed to operate before VMInit:
14289 Set/GetEnvironmentLocalStorage
14290 GetMethodDeclaringClass
14291 GetClassSignature
14292 GetClassModifiers
14293 IsInterface
14294 IsArrayClass
14295 GetMethodName
14296 GetMethodModifiers
14297 GetMaxLocals
14298 GetArgumentsSize
14299 GetLineNumberTable
14300 GetMethodLocation
14301 IsMethodNative
14302 IsMethodSynthetic.
14303 Other changes (to XSL):
14304 Argument description should show asterisk after not before pointers.
14305 NotifyFramePop, GetFrameLocationm and all the local variable operations
14306 should hsve the NO_MORE_FRAMES error added.
14307 Not alive threads should have a different error return than invalid thread.
14308 </change>
14309 <change date="7 July 2003" version="v73">
14310 VerboseOutput event was missing message parameter.
14311 Minor fix-ups.
14312 </change>
14313 <change date="14 July 2003" version="v74">
14314 Technical Publications Department corrections.
14315 Allow thread and environment local storage to be set to NULL.
14316 </change>
14317 <change date="23 July 2003" version="v75">
14318 Use new Agent_OnLoad rather than overloaded JVM_OnLoad.
14319 Add JNICALL to callbacks (XSL).
14320 Document JNICALL requirement for both events and callbacks (XSL).
14321 Restrict RedefineClasses to methods and attributes.
14322 Elide the VerboseOutput event.
14323 VMObjectAlloc: restrict when event is sent and remove method parameter.
14324 Finish loose ends from Tech Pubs edit.
14325 </change>
14326 <change date="24 July 2003" version="v76">
14327 Change ClassFileLoadHook event to send the class instead of a boolean of redefine.
14328 </change>
14329 <change date="24 July 2003" version="v77">
14330 XML fixes.
14331 Minor text clarifications and corrections.
14332 </change>
14333 <change date="24 July 2003" version="v78">
14334 Remove GetExceptionHandlerTable and GetThrownExceptions from <jvmti/>.
14335 Clarify that stack frames are JVM Spec frames.
14336 Split can_get_source_info into can_get_source_file_name, can_get_line_numbers,
14337 and can_get_source_debug_extension.
14338 PopFrame cannot have a native calling method.
14339 Removed incorrect statement in GetClassloaderClasses
14340 (see <vmspec chapter="4.4"/>).
14341 </change>
14342 <change date="24 July 2003" version="v79">
14343 XML and text fixes.
14344 Move stack frame description into Stack Frame category.
14345 </change>
14346 <change date="26 July 2003" version="v80">
14347 Allow NULL (means bootstrap loader) for GetClassloaderClasses.
14348 Add new heap reference kinds for references from classes.
14349 Add timer information struct and query functions.
14350 Add AvailableProcessors.
14351 Rename GetOtherThreadCpuTime to GetThreadCpuTime.
14352 Explicitly add JVMTI_ERROR_INVALID_THREAD and JVMTI_ERROR_THREAD_NOT_ALIVE
14353 to SetEventNotification mode.
14354 Add initial thread to the VM_INIT event.
14355 Remove platform assumptions from AddToBootstrapClassLoaderSearch.
14356 </change>
14357 <change date="26 July 2003" version="v81">
14358 Grammar and clarity changes per review.
14359 </change>
14360 <change date="27 July 2003" version="v82">
14361 More grammar and clarity changes per review.
14362 Add Agent_OnUnload.
14363 </change>
14364 <change date="28 July 2003" version="v83">
14365 Change return type of Agent_OnUnload to void.
14366 </change>
14367 <change date="28 July 2003" version="v84">
14368 Rename JVMTI_REFERENCE_ARRAY to JVMTI_REFERENCE_ARRAY_ELEMENT.
14369 </change>
14370 <change date="28 July 2003" version="v85">
14371 Steal java.lang.Runtime.availableProcessors() wording for
14372 AvailableProcessors().
14373 Guarantee that zero will never be an event ID.
14374 Remove some issues which are no longer issues.
14375 Per review, rename and more completely document the timer
14376 information functions.
14377 </change>
14378 <change date="29 July 2003" version="v86">
14379 Non-spec visible change to XML controlled implementation:
14380 SetThreadLocalStorage must run in VM mode.
14381 </change>
14382 <change date="5 August 2003" version="0.1.87">
14383 Add GetErrorName.
14384 Add varargs warning to jvmtiExtensionEvent.
14385 Remove "const" on the jvmtiEnv* of jvmtiExtensionEvent.
14386 Remove unused can_get_exception_info capability.
14387 Pass jvmtiEnv* and JNIEnv* to the jvmtiStartFunction.
14388 Fix jvmtiExtensionFunctionInfo.func declared type.
14389 Extension function returns error code.
14390 Use new version numbering.
14391 </change>
14392 <change date="5 August 2003" version="0.2.88">
14393 Remove the ClassUnload event.
14394 </change>
14395 <change date="8 August 2003" version="0.2.89">
14396 Heap reference iterator callbacks return an enum that
14397 allows outgoing object references to be ignored.
14398 Allow JNIEnv as a param type to extension events/functions.
14399 </change>
14400 <change date="15 August 2003" version="0.2.90">
14401 Fix a typo.
14402 </change>
14403 <change date="2 September 2003" version="0.2.91">
14404 Remove all metadata functions: GetClassMetadata,
14405 GetFieldMetadata, and GetMethodMetadata.
14406 </change>
14407 <change date="1 October 2003" version="0.2.92">
14408 Mark the functions Allocate. Deallocate, RawMonitor*,
14409 SetEnvironmentLocalStorage, and GetEnvironmentLocalStorage
14410 as safe for use in heap callbacks and GC events.
14411 </change>
14412 <change date="24 November 2003" version="0.2.93">
14413 Add pass through opaque user data pointer to heap iterate
14414 functions and callbacks.
14415 In the CompiledMethodUnload event, send the code address.
14416 Add GarbageCollectionOccurred event.
14417 Add constant pool reference kind.
14418 Mark the functions CreateRawMonitor and DestroyRawMonitor
14419 as safe for use in heap callbacks and GC events.
14420 Clarify: VMDeath, GetCurrentThreadCpuTimerInfo,
14421 GetThreadCpuTimerInfo, IterateOverReachableObjects,
14422 IterateOverObjectsReachableFromObject, GetTime and
14423 JVMTI_ERROR_NULL_POINTER.
14424 Add missing errors to: GenerateEvents and
14425 AddToBootstrapClassLoaderSearch.
14426 Fix description of ClassFileLoadHook name parameter.
14427 In heap callbacks and GC/ObjectFree events, specify
14428 that only explicitly allowed functions can be called.
14429 Allow GetCurrentThreadCpuTimerInfo, GetCurrentThreadCpuTime,
14430 GetTimerInfo, and GetTime during callback.
14431 Allow calling SetTag/GetTag during the onload phase.
14432 SetEventNotificationMode, add: error attempted inappropriate
14433 thread level control.
14434 Remove jvmtiExceptionHandlerEntry.
14435 Fix handling of native methods on the stack --
14436 location_ptr param of GetFrameLocation, remove
14437 JVMTI_ERROR_OPAQUE_FRAME from GetFrameLocation,
14438 jvmtiFrameInfo.location, and jlocation.
14439 Remove typo (from JVMPI) implying that the MonitorWaited
14440 event is sent on sleep.
14441 </change>
14442 <change date="25 November 2003" version="0.2.94">
14443 Clarifications and typos.
14444 </change>
14445 <change date="3 December 2003" version="0.2.95">
14446 Allow NULL user_data in heap iterators.
14447 </change>
14448 <change date="28 January 2004" version="0.2.97">
14449 Add GetThreadState, deprecate GetThreadStatus.
14450 </change>
14451 <change date="29 January 2004" version="0.2.98">
14452 INVALID_SLOT and TYPE_MISMATCH errors should be optional.
14453 </change>
14454 <change date="12 February 2004" version="0.2.102">
14455 Remove MonitorContendedExit.
14456 Added JNIEnv parameter to VMObjectAlloc.
14457 Clarified definition of class_tag and referrer_index
14458 parameters to heap callbacks.
14459 </change>
14460 <change date="16 Febuary 2004" version="0.2.103">
14461 Document JAVA_TOOL_OPTIONS.
14462 </change>
14463 <change date="17 Febuary 2004" version="0.2.105">
14464 Divide start phase into primordial and start.
14465 Add VMStart event
14466 Change phase associations of functions and events.
14467 </change>
14468 <change date="18 Febuary 2004" version="0.3.6">
14469 Elide deprecated GetThreadStatus.
14470 Bump minor version, subtract 100 from micro version
14471 </change>
14472 <change date="18 Febuary 2004" version="0.3.7">
14473 Document that timer nanosecond values are unsigned.
14474 Clarify text having to do with native methods.
14475 </change>
14476 <change date="19 Febuary 2004" version="0.3.8">
14477 Fix typos.
14478 Remove elided deprecated GetThreadStatus.
14479 </change>
14480 <change date="23 Febuary 2004" version="0.3.9">
14481 Require NotifyFramePop to act on suspended threads.
14482 </change>
14483 <change date="24 Febuary 2004" version="0.3.10">
14484 Add capabilities
14485 (<internallink id="jvmtiCapabilities.can_redefine_any_class"
14486 ><code>can_redefine_any_class</code></internallink>
14487 and
14488 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events"
14489 ><code>can_generate_all_class_hook_events</code></internallink>)
14490 and an error (<errorlink id="JVMTI_ERROR_UNMODIFIABLE_CLASS"></errorlink>)
14491 which allow some classes to be unmodifiable.
14492 </change>
14493 <change date="28 Febuary 2004" version="0.3.11">
14494 Add JVMTI_ERROR_MUST_POSSESS_CAPABILITY to SetEventNotificationMode.
14495 </change>
14496 <change date="8 March 2004" version="0.3.12">
14497 Clarified CompiledMethodUnload so that it is clear the event
14498 may be posted after the class has been unloaded.
14499 </change>
14500 <change date="5 March 2004" version="0.3.13">
14501 Change the size parameter of VMObjectAlloc to jlong to match GetObjectSize.
14502 </change>
14503 <change date="13 March 2004" version="0.3.14">
14504 Added guideline for the use of the JNI FindClass function in event
14505 callback functions.
14506 </change>
14507 <change date="15 March 2004" version="0.3.15">
14508 Add GetAllStackTraces and GetThreadListStackTraces.
14509 </change>
14510 <change date="19 March 2004" version="0.3.16">
14511 ClassLoad and ClassPrepare events can be posted during start phase.
14512 </change>
14513 <change date="25 March 2004" version="0.3.17">
14514 Add JVMTI_ERROR_NATIVE_METHOD to GetLineNumberTable, GetLocalVariableTable,
14515 GetMaxLocals, GetArgumentsSize, GetMethodLocation, GetBytecodes.
14516 </change>
14517 <change date="29 March 2004" version="0.3.18">
14518 Return the timer kind in the timer information structure.
14519 </change>
14520 <change date="31 March 2004" version="0.3.19">
14521 Spec clarifications:
14522 JVMTI_THREAD_STATE_IN_NATIVE might not include JNI or <jvmti/>.
14523 ForceGarbageCollection does not run finalizers.
14524 The context of the specification is the Java platform.
14525 Warn about early instrumentation.
14526 </change>
14527 <change date="1 April 2004" version="0.3.20">
14528 Refinements to the above clarifications and
14529 Clarify that an error returned by Agent_OnLoad terminates the VM.
14530 </change>
14531 <change date="1 April 2004" version="0.3.21">
14532 Array class creation does not generate a class load event.
14533 </change>
14534 <change date="7 April 2004" version="0.3.22">
14535 Align thread state hierarchy more closely with java.lang.Thread.State.
14536 </change>
14537 <change date="12 April 2004" version="0.3.23">
14538 Clarify the documentation of thread state.
14539 </change>
14540 <change date="19 April 2004" version="0.3.24">
14541 Remove GarbageCollectionOccurred event -- can be done by agent.
14542 </change>
14543 <change date="22 April 2004" version="0.3.25">
14544 Define "command-line option".
14545 </change>
14546 <change date="29 April 2004" version="0.3.26">
14547 Describe the intended use of bytecode instrumentation.
14548 Fix description of extension event first parameter.
14549 </change>
14550 <change date="30 April 2004" version="0.3.27">
14551 Clarification and typos.
14552 </change>
14553 <change date="18 May 2004" version="0.3.28">
14554 Remove DataDumpRequest event.
14555 </change>
14556 <change date="18 May 2004" version="0.3.29">
14557 Clarify RawMonitorWait with zero timeout.
14558 Clarify thread state after RunAgentThread.
14559 </change>
14560 <change date="24 May 2004" version="0.3.30">
14561 Clean-up: fix bad/old links, etc.
14562 </change>
14563 <change date="30 May 2004" version="0.3.31">
14564 Clarifications including:
14565 All character strings are modified UTF-8.
14566 Agent thread visibiity.
14567 Meaning of obsolete method version.
14568 Thread invoking heap callbacks,
14569 </change>
14570 <change date="1 June 2004" version="1.0.32">
14571 Bump major.minor version numbers to "1.0".
14572 </change>
14573 <change date="2 June 2004" version="1.0.33">
14574 Clarify interaction between ForceGarbageCollection
14575 and ObjectFree.
14576 </change>
14577 <change date="6 June 2004" version="1.0.34">
14578 Restrict AddToBootstrapClassLoaderSearch and
14579 SetSystemProperty to the OnLoad phase only.
14580 </change>
14581 <change date="11 June 2004" version="1.0.35">
14582 Fix typo in SetTag.
14583 </change>
14584 <change date="18 June 2004" version="1.0.36">
14585 Fix trademarks.
14586 Add missing parameter in example GetThreadState usage.
14587 </change>
14588 <change date="4 August 2004" version="1.0.37">
14589 Copyright updates.
14590 </change>
14591 <change date="5 November 2004" version="1.0.38">
14592 Add missing function table layout.
14593 Add missing description of C++ member function format of functions.
14594 Clarify that name in CFLH can be NULL.
14595 Released as part of <tm>J2SE</tm> 5.0.
14596 </change>
14597 <change date="24 April 2005" version="1.1.47">
14598 Bump major.minor version numbers to "1.1".
14599 Add ForceEarlyReturn* functions.
14600 Add GetOwnedMonitorStackDepthInfo function.
14601 Add GetCurrentThread function.
14602 Add "since" version marker.
14603 Add AddToSystemClassLoaderSearch.
14604 Allow AddToBootstrapClassLoaderSearch be used in live phase.
14605 Fix historic rubbish in the descriptions of the heap_object_callback
14606 parameter of IterateOverHeap and IterateOverInstancesOfClass functions;
14607 disallow NULL for this parameter.
14608 Clarify, correct and make consistent: wording about current thread,
14609 opaque frames and insufficient number of frames in PopFrame.
14610 Consistently use "current frame" rather than "topmost".
14611 Clarify the JVMTI_ERROR_TYPE_MISMATCH errors in GetLocal* and SetLocal*
14612 by making them compatible with those in ForceEarlyReturn*.
14613 Many other clarifications and wording clean ups.
14614 </change>
14615 <change date="25 April 2005" version="1.1.48">
14616 Add GetConstantPool.
14617 Switch references to the first edition of the VM Spec, to the seconds edition.
14618 </change>
14619 <change date="26 April 2005" version="1.1.49">
14620 Clarify minor/major version order in GetConstantPool.
14621 </change>
14622 <change date="26 April 2005" version="1.1.50">
14623 Add SetNativeMethodPrefix and SetNativeMethodPrefixes.
14624 Reassign GetOwnedMonitorStackDepthInfo to position 153.
14625 Break out Class Loader Search in its own documentation category.
14626 Deal with overly long lines in XML source.
14627 </change>
14628 <change date="29 April 2005" version="1.1.51">
14629 Allow agents be started in the live phase.
14630 Added paragraph about deploying agents.
14631 </change>
14632 <change date="30 April 2005" version="1.1.52">
14633 Add specification description to SetNativeMethodPrefix(es).
14634 Better define the conditions on GetConstantPool.
14635 </change>
14636 <change date="30 April 2005" version="1.1.53">
14637 Break out the GetClassVersionNumber function from GetConstantPool.
14638 Clean-up the references to the VM Spec.
14639 </change>
14640 <change date="1 May 2005" version="1.1.54">
14641 Allow SetNativeMethodPrefix(es) in any phase.
14642 Add clarifications about the impact of redefinition on GetConstantPool.
14643 </change>
14644 <change date="2 May 2005" version="1.1.56">
14645 Various clarifications to SetNativeMethodPrefix(es).
14646 </change>
14647 <change date="2 May 2005" version="1.1.57">
14648 Add missing performance warning to the method entry event.
14649 </change>
14650 <change date="5 May 2005" version="1.1.58">
14651 Remove internal JVMDI support.
14652 </change>
14653 <change date="8 May 2005" version="1.1.59">
14654 Add <functionlink id="RetransformClasses"/>.
14655 Revamp the bytecode instrumentation documentation.
14656 Change <functionlink id="IsMethodObsolete"/> to no longer
14657 require the can_redefine_classes capability.
14658 </change>
14659 <change date="11 May 2005" version="1.1.63">
14660 Clarifications for retransformation.
14661 </change>
14662 <change date="11 May 2005" version="1.1.64">
14663 Clarifications for retransformation, per review.
14664 Lock "retransformation (in)capable" at class load enable time.
14665 </change>
14666 <change date="4 June 2005" version="1.1.67">
14667 Add new heap functionity which supports reporting primitive values,
14668 allows setting the referrer tag, and has more powerful filtering:
14669 FollowReferences, IterateThroughHeap, and their associated
14670 callbacks, structs, enums, and constants.
14671 </change>
14672 <change date="4 June 2005" version="1.1.68">
14673 Clarification.
14674 </change>
14675 <change date="6 June 2005" version="1.1.69">
14676 FollowReferences, IterateThroughHeap: Put callbacks in a struct;
14677 Add missing error codes; reduce bits in the visit control flags.
14678 </change>
14679 <change date="14 June 2005" version="1.1.70">
14680 More on new heap functionity: spec clean-up per review.
14681 </change>
14682 <change date="15 June 2005" version="1.1.71">
14683 More on new heap functionity: Rename old heap section to Heap (1.0).
14684 </change>
14685 <change date="21 June 2005" version="1.1.72">
14686 Fix typos.
14687 </change>
14688 <change date="27 June 2005" version="1.1.73">
14689 Make referrer info structure a union.
14690 </change>
14691 <change date="9 September 2005" version="1.1.74">
14692 In new heap functions:
14693 Add missing superclass reference kind.
14694 Use a single scheme for computing field indexes.
14695 Remove outdated references to struct based referrer info.
14696 </change>
14697 <change date="12 September 2005" version="1.1.75">
14698 Don't callback during FollowReferences on frivolous java.lang.Object superclass.
14699 </change>
14700 <change date="13 September 2005" version="1.1.76">
14701 In string primitive callback, length now Unicode length.
14702 In array and string primitive callbacks, value now "const".
14703 Note possible compiler impacts on setting JNI function table.
14704 </change>
14705 <change date="13 September 2005" version="1.1.77">
14706 GetClassVersionNumbers() and GetConstantPool() should return
14707 error on array or primitive class.
14708 </change>
14709 <change date="14 September 2005" version="1.1.78">
14710 Grammar fixes.
14711 </change>
14712 <change date="26 September 2005" version="1.1.79">
14713 Add IsModifiableClass query.
14714 </change>
14715 <change date="9 February 2006" version="1.1.81">
14716 Add referrer_class_tag parameter to jvmtiHeapReferenceCallback.
14717 </change>
14718 <change date="13 February 2006" version="1.1.82">
14719 Doc fixes: update can_redefine_any_class to include retransform.
14720 Clarify that exception events cover all Throwables.
14721 In GetStackTrace, no test is done for start_depth too big if start_depth is zero,
14722 Clarify fields reported in Primitive Field Callback -- static vs instance.
14723 Repair confusing names of heap types, including callback names.
14724 Require consistent usage of stack depth in the face of thread launch methods.
14725 Note incompatibility of <jvmti/> memory management with other systems.
14726 </change>
14727 <change date="14 February 2006" version="1.1.85">
14728 Fix typos and missing renames.
14729 </change>
14730 <change date="13 March 2006" version="1.1.86">
14731 Clarify that jmethodIDs and jfieldIDs can be saved.
14732 Clarify that Iterate Over Instances Of Class includes subclasses.
14733 </change>
14734 <change date="14 March 2006" version="1.1.87">
14735 Better phrasing.
14736 </change>
14737 <change date="16 March 2006" version="1.1.88">
14738 Match the referrer_index for static fields in Object Reference Callback
14739 with the Reference Implementation (and all other known implementations);
14740 that is, make it match the definition for instance fields.
14741 In GetThreadListStackTraces, add JVMTI_ERROR_INVALID_THREAD to cover
14742 an invalid thread in the list; and specify that not started threads
14743 return empty stacks.
14744 </change>
14745 <change date="17 March 2006" version="1.1.89">
14746 Typo.
14747 </change>
14748 <change date="25 March 2006" version="1.1.90">
14749 Typo.
14750 </change>
14751 <change date="6 April 2006" version="1.1.91">
14752 Remove restrictions on AddToBootstrapClassLoaderSearch and
14753 AddToSystemClassLoaderSearch.
14754 </change>
14755 <change date="1 May 2006" version="1.1.93">
14756 Changed spec to return -1 for monitor stack depth for the
14757 implementation which can not determine stack depth.
14758 </change>
14759 <change date="3 May 2006" version="1.1.94">
14760 Corrections for readability and accuracy courtesy of Alan Pratt of IBM.
14761 List the object relationships reported in FollowReferences.
14762 </change>
14763 <change date="5 May 2006" version="1.1.95">
14764 Clarify the object relationships reported in FollowReferences.
14765 </change>
14766 <change date="28 June 2006" version="1.1.98">
14767 Clarify DisposeEnvironment; add warning.
14768 Fix typos in SetLocalXXX "retrieve" => "set".
14769 Clarify that native method prefixes must remain set while used.
14770 Clarify that exactly one Agent_OnXXX is called per agent.
14771 Clarify that library loading is independent from start-up.
14772 Remove ambiguous reference to Agent_OnLoad in the Agent_OnUnload spec.
14773 </change>
14774 <change date="31 July 2006" version="1.1.99">
14775 Clarify the interaction between functions and exceptions.
14776 Clarify and give examples of field indices.
14777 Remove confusing "That is" sentence from MonitorWait and MonitorWaited events.
14778 Update links to point to Java 6.
14779 </change>
14780 <change date="6 August 2006" version="1.1.102">
14781 Add ResourceExhaustedEvent.
14782 </change>
14783 <change date="11 October 2012" version="1.2.2">
14784 Fixed the "HTTP" and "Missing Anchor" errors reported by the LinkCheck tool.
14785 </change>
14786 <change date="19 June 2013" version="1.2.3">
14787 Added support for statically linked agents.
14788 </change>
14789 <change date="13 October 2016" version="9.0.0">
14790 Support for modules:
14791 - The majorversion is 9 now
14792 - The ClassFileLoadHook events are not sent during the primordial phase anymore.
14793 - Allow CompiledMethodLoad events at start phase
14794 - Add new capabilities:
14795 - can_generate_early_vmstart
14796 - can_generate_early_class_hook_events
14797 - Add new functions:
14798 - GetAllModules
14799 - AddModuleReads, AddModuleExports, AddModuleOpens, AddModuleUses, AddModuleProvides
14800 - IsModifiableModule
14801 Clarified can_redefine_any_classes, can_retransform_any_classes and IsModifiableClass API to
14802 disallow some implementation defined classes.
14803 </change>
14804 <change date="12 February 2017" version="9.0.0">
14805 Minor update for GetCurrentThread function:
14806 - The function may return NULL in the start phase if the
14807 can_generate_early_vmstart capability is enabled.
14808 </change>
14809 </changehistory>
14810
14811 </specification>
14812 <!-- Keep this comment at the end of the file
14813 Local variables:
14814 mode: sgml
14815 sgml-omittag:t
14816 sgml-shorttag:t
14817 sgml-namecase-general:t
14818 sgml-general-insert-case:lower
14819 sgml-minimize-attributes:nil
14820 sgml-always-quote-attributes:t
14821 sgml-indent-step:2
14822 sgml-indent-data:t
14823 sgml-parent-document:nil
14824 sgml-exposed-tags:nil
14825 sgml-local-catalogs:nil
14826 sgml-local-ecat-files:nil
14827 End:
14828 -->