/* * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ class ThreadSafepointState; class ThreadProfiler; class JvmtiThreadState; class JvmtiGetLoadedClassesClosure; class ThreadStatistics; class ConcurrentLocksDump; class ParkEvent ; class ciEnv; class CompileThread; class CompileLog; class CompileTask; class CompileQueue; class CompilerCounters; class vframeArray; class DeoptResourceMark; class jvmtiDeferredLocalVariableSet; class GCTaskQueue; class ThreadClosure; class IdealGraphPrinter; // Class hierarchy // - Thread // - NamedThread // - VMThread // - ConcurrentGCThread // - WorkerThread // - GangWorker // - GCTaskThread // - JavaThread // - WatcherThread class Thread: public ThreadShadow { friend class VMStructs; private: // Exception handling // (Note: _pending_exception and friends are in ThreadShadow) //oop _pending_exception; // pending exception for current thread // const char* _exception_file; // file information for exception (debugging only) // int _exception_line; // line information for exception (debugging only) // Support for forcing alignment of thread objects for biased locking void* _real_malloc_address; public: void* operator new(size_t size); void operator delete(void* p); private: // *************************************************************** // Suspend and resume support // *************************************************************** // // VM suspend/resume no longer exists - it was once used for various // things including safepoints but was deprecated and finally removed // in Java 7. Because VM suspension was considered "internal" Java-level // suspension was considered "external", and this legacy naming scheme // remains. // // External suspend/resume requests come from JVM_SuspendThread, // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI // ResumeThread. External // suspend requests cause _external_suspend to be set and external // resume requests cause _external_suspend to be cleared. // External suspend requests do not nest on top of other external // suspend requests. The higher level APIs reject suspend requests // for already suspended threads. // // The external_suspend // flag is checked by has_special_runtime_exit_condition() and java thread // will self-suspend when handle_special_runtime_exit_condition() is // called. Most uses of the _thread_blocked state in JavaThreads are // considered the same as being externally suspended; if the blocking // condition lifts, the JavaThread will self-suspend. Other places // where VM checks for external_suspend include: // + mutex granting (do not enter monitors when thread is suspended) // + state transitions from _thread_in_native // // In general, java_suspend() does not wait for an external suspend // request to complete. When it returns, the only guarantee is that // the _external_suspend field is true. // // wait_for_ext_suspend_completion() is used to wait for an external // suspend request to complete. External suspend requests are usually // followed by some other interface call that requires the thread to // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into // the interface that requires quiescence, we give the JavaThread a // chance to self-suspend before we need it to be quiescent. This // improves overall suspend/query performance. // // _suspend_flags controls the behavior of java_ suspend/resume. // It must be set under the protection of SR_lock. Read from the flag is // OK without SR_lock as long as the value is only used as a hint. // (e.g., check _external_suspend first without lock and then recheck // inside SR_lock and finish the suspension) // // _suspend_flags is also overloaded for other "special conditions" so // that a single check indicates whether any special action is needed // eg. for async exceptions. // ------------------------------------------------------------------- // Notes: // 1. The suspend/resume logic no longer uses ThreadState in OSThread // but we still update its value to keep other part of the system (mainly // JVMTI) happy. ThreadState is legacy code (see notes in // osThread.hpp). // // 2. It would be more natural if set_external_suspend() is private and // part of java_suspend(), but that probably would affect the suspend/query // performance. Need more investigation on this. // // suspend/resume lock: used for self-suspend Monitor* _SR_lock; protected: enum SuspendFlags { // NOTE: avoid using the sign-bit as cc generates different test code // when the sign-bit is used, and sometimes incorrectly - see CR 6398077 _external_suspend = 0x20000000U, // thread is asked to self suspend _ext_suspended = 0x40000000U, // thread has self-suspended _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt _has_async_exception = 0x00000001U // there is a pending async exception }; // various suspension related flags - atomically updated // overloaded for async exception checking in check_special_condition_for_native_trans. volatile uint32_t _suspend_flags; private: int _num_nested_signal; public: void enter_signal_handler() { _num_nested_signal++; } void leave_signal_handler() { _num_nested_signal--; } bool is_inside_signal_handler() const { return _num_nested_signal > 0; } private: // Debug tracing static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN; // Active_handles points to a block of handles JNIHandleBlock* _active_handles; // One-element thread local free list JNIHandleBlock* _free_handle_block; // Point to the last handle mark HandleMark* _last_handle_mark; // The parity of the last strong_roots iteration in which this thread was // claimed as a task. jint _oops_do_parity; public: void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; } HandleMark* last_handle_mark() const { return _last_handle_mark; } private: // debug support for checking if code does allow safepoints or not // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on // mutex, or blocking on an object synchronizer (Java locking). // If !allow_safepoint(), then an assertion failure will happen in any of the above cases // If !allow_allocation(), then an assertion failure will happen during allocation // (Hence, !allow_safepoint() => !allow_allocation()). // // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters. // NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen debug_only (int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops. // Used by SkipGCALot class. NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot? // Record when GC is locked out via the GC_locker mechanism CHECK_UNHANDLED_OOPS_ONLY(int _gc_locked_out_count;) friend class No_Alloc_Verifier; friend class No_Safepoint_Verifier; friend class Pause_No_Safepoint_Verifier; friend class ThreadLocalStorage; friend class GC_locker; ThreadLocalAllocBuffer _tlab; // Thread-local eden int _vm_operation_started_count; // VM_Operation support int _vm_operation_completed_count; // VM_Operation support ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread // is waiting to lock bool _current_pending_monitor_is_from_java; // locking is from Java code // ObjectMonitor on which this thread called Object.wait() ObjectMonitor* _current_waiting_monitor; // Private thread-local objectmonitor list - a simple cache organized as a SLL. public: ObjectMonitor * omFreeList ; int omFreeCount ; // length of omFreeList int omFreeProvision ; // reload chunk size public: enum { is_definitely_current_thread = true }; // Constructor Thread(); virtual ~Thread(); // initializtion void initialize_thread_local_storage(); // thread entry point virtual void run(); // Testers virtual bool is_VM_thread() const { return false; } virtual bool is_Java_thread() const { return false; } // Remove this ifdef when C1 is ported to the compiler interface. virtual bool is_Compiler_thread() const { return false; } virtual bool is_hidden_from_external_view() const { return false; } virtual bool is_jvmti_agent_thread() const { return false; } // True iff the thread can perform GC operations at a safepoint. // Generally will be true only of VM thread and parallel GC WorkGang // threads. virtual bool is_GC_task_thread() const { return false; } virtual bool is_Watcher_thread() const { return false; } virtual bool is_ConcurrentGC_thread() const { return false; } virtual bool is_Named_thread() const { return false; } virtual char* name() const { return (char*)"Unknown thread"; } // Returns the current thread static inline Thread* current(); // Common thread operations static void set_priority(Thread* thread, ThreadPriority priority); static ThreadPriority get_priority(const Thread* const thread); static void start(Thread* thread); static void interrupt(Thread* thr); static bool is_interrupted(Thread* thr, bool clear_interrupted); Monitor* SR_lock() const { return _SR_lock; } bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; } void set_suspend_flag(SuspendFlags f) { assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch"); uint32_t flags; do { flags = _suspend_flags; } while (Atomic::cmpxchg((jint)(flags | f), (volatile jint*)&_suspend_flags, (jint)flags) != (jint)flags); } void clear_suspend_flag(SuspendFlags f) { assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch"); uint32_t flags; do { flags = _suspend_flags; } while (Atomic::cmpxchg((jint)(flags & ~f), (volatile jint*)&_suspend_flags, (jint)flags) != (jint)flags); } void set_has_async_exception() { set_suspend_flag(_has_async_exception); } void clear_has_async_exception() { clear_suspend_flag(_has_async_exception); } // Support for Unhandled Oop detection #ifdef CHECK_UNHANDLED_OOPS private: UnhandledOops *_unhandled_oops; public: UnhandledOops* unhandled_oops() { return _unhandled_oops; } // Mark oop safe for gc. It may be stack allocated but won't move. void allow_unhandled_oop(oop *op) { if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op); } // Clear oops at safepoint so crashes point to unhandled oop violator void clear_unhandled_oops() { if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops(); } bool is_gc_locked_out() { return _gc_locked_out_count > 0; } #endif // CHECK_UNHANDLED_OOPS #ifndef PRODUCT bool skip_gcalot() { return _skip_gcalot; } void set_skip_gcalot(bool v) { _skip_gcalot = v; } #endif public: // Installs a pending exception to be inserted later static void send_async_exception(oop thread_oop, oop java_throwable); // Resource area ResourceArea* resource_area() const { return _resource_area; } void set_resource_area(ResourceArea* area) { _resource_area = area; } OSThread* osthread() const { return _osthread; } void set_osthread(OSThread* thread) { _osthread = thread; } // JNI handle support JNIHandleBlock* active_handles() const { return _active_handles; } void set_active_handles(JNIHandleBlock* block) { _active_handles = block; } JNIHandleBlock* free_handle_block() const { return _free_handle_block; } void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; } // Internal handle support HandleArea* handle_area() const { return _handle_area; } void set_handle_area(HandleArea* area) { _handle_area = area; } // Thread-Local Allocation Buffer (TLAB) support ThreadLocalAllocBuffer& tlab() { return _tlab; } void initialize_tlab() { if (UseTLAB) { tlab().initialize(); } } // VM operation support int vm_operation_ticket() { return ++_vm_operation_started_count; } int vm_operation_completed_count() { return _vm_operation_completed_count; } void increment_vm_operation_completed_count() { _vm_operation_completed_count++; } // For tracking the heavyweight monitor the thread is pending on. ObjectMonitor* current_pending_monitor() { return _current_pending_monitor; } void set_current_pending_monitor(ObjectMonitor* monitor) { _current_pending_monitor = monitor; } void set_current_pending_monitor_is_from_java(bool from_java) { _current_pending_monitor_is_from_java = from_java; } bool current_pending_monitor_is_from_java() { return _current_pending_monitor_is_from_java; } // For tracking the ObjectMonitor on which this thread called Object.wait() ObjectMonitor* current_waiting_monitor() { return _current_waiting_monitor; } void set_current_waiting_monitor(ObjectMonitor* monitor) { _current_waiting_monitor = monitor; } // GC support // Apply "f->do_oop" to all root oops in "this". // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames void oops_do(OopClosure* f, CodeBlobClosure* cf); // Handles the parallel case for the method below. private: bool claim_oops_do_par_case(int collection_parity); public: // Requires that "collection_parity" is that of the current strong roots // iteration. If "is_par" is false, sets the parity of "this" to // "collection_parity", and returns "true". If "is_par" is true, // uses an atomic instruction to set the current threads parity to // "collection_parity", if it is not already. Returns "true" iff the // calling thread does the update, this indicates that the calling thread // has claimed the thread's stack as a root groop in the current // collection. bool claim_oops_do(bool is_par, int collection_parity) { if (!is_par) { _oops_do_parity = collection_parity; return true; } else { return claim_oops_do_par_case(collection_parity); } } // Sweeper support void nmethods_do(CodeBlobClosure* cf); // Tells if adr belong to this thread. This is used // for checking if a lock is owned by the running thread. // Used by fast lock support virtual bool is_lock_owned(address adr) const; // Check if address is in the stack of the thread (not just for locks). // Warning: the method can only be used on the running thread bool is_in_stack(address adr) const; // Sets this thread as starting thread. Returns failure if thread // creation fails due to lack of memory, too many threads etc. bool set_as_starting_thread(); protected: // OS data associated with the thread OSThread* _osthread; // Platform-specific thread information // Thread local resource area for temporary allocation within the VM ResourceArea* _resource_area; // Thread local handle area for allocation of handles within the VM HandleArea* _handle_area; // Support for stack overflow handling, get_thread, etc. address _stack_base; size_t _stack_size; uintptr_t _self_raw_id; // used by get_thread (mutable) int _lgrp_id; public: // Stack overflow support address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; } void set_stack_base(address base) { _stack_base = base; } size_t stack_size() const { return _stack_size; } void set_stack_size(size_t size) { _stack_size = size; } void record_stack_base_and_size(); int lgrp_id() const { return _lgrp_id; } void set_lgrp_id(int value) { _lgrp_id = value; } // Printing void print_on(outputStream* st) const; void print() const { print_on(tty); } virtual void print_on_error(outputStream* st, char* buf, int buflen) const; // Debug-only code #ifdef ASSERT private: // Deadlock detection support for Mutex locks. List of locks own by thread. Monitor *_owned_locks; // Mutex::set_owner_implementation is the only place where _owned_locks is modified, // thus the friendship friend class Mutex; friend class Monitor; public: void print_owned_locks_on(outputStream* st) const; void print_owned_locks() const { print_owned_locks_on(tty); } Monitor * owned_locks() const { return _owned_locks; } bool owns_locks() const { return owned_locks() != NULL; } bool owns_locks_but_compiled_lock() const; // Deadlock detection bool allow_allocation() { return _allow_allocation_count == 0; } #endif void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN; private: volatile int _jvmti_env_iteration_count; public: void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; } void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; } bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; } // Code generation static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file ); } static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line ); } static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles ); } static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base ); } static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size ); } static ByteSize omFreeList_offset() { return byte_offset_of(Thread, omFreeList); } #define TLAB_FIELD_OFFSET(name) \ static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); } TLAB_FIELD_OFFSET(start) TLAB_FIELD_OFFSET(end) TLAB_FIELD_OFFSET(top) TLAB_FIELD_OFFSET(pf_top) TLAB_FIELD_OFFSET(size) // desired_size TLAB_FIELD_OFFSET(refill_waste_limit) TLAB_FIELD_OFFSET(number_of_refills) TLAB_FIELD_OFFSET(fast_refill_waste) TLAB_FIELD_OFFSET(slow_allocations) #undef TLAB_FIELD_OFFSET public: volatile intptr_t _Stalled ; volatile int _TypeTag ; ParkEvent * _ParkEvent ; // for synchronized() ParkEvent * _SleepEvent ; // for Thread.sleep ParkEvent * _MutexEvent ; // for native internal Mutex/Monitor ParkEvent * _MuxEvent ; // for low-level muxAcquire-muxRelease int NativeSyncRecursion ; // diagnostic volatile int _OnTrap ; // Resume-at IP delta jint _hashStateW ; // Marsaglia Shift-XOR thread-local RNG jint _hashStateX ; // thread-specific hashCode generator state jint _hashStateY ; jint _hashStateZ ; void * _schedctl ; intptr_t _ScratchA, _ScratchB ; // Scratch locations for fast-path sync code static ByteSize ScratchA_offset() { return byte_offset_of(Thread, _ScratchA ); } static ByteSize ScratchB_offset() { return byte_offset_of(Thread, _ScratchB ); } volatile jint rng [4] ; // RNG for spin loop // Low-level leaf-lock primitives used to implement synchronization // and native monitor-mutex infrastructure. // Not for general synchronization use. static void SpinAcquire (volatile int * Lock, const char * Name) ; static void SpinRelease (volatile int * Lock) ; static void muxAcquire (volatile intptr_t * Lock, const char * Name) ; static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ; static void muxRelease (volatile intptr_t * Lock) ; }; // Inline implementation of Thread::current() // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of // startup. // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same // period. This is inlined in thread_.inline.hpp. inline Thread* Thread::current() { #ifdef ASSERT // This function is very high traffic. Define PARANOID to enable expensive // asserts. #ifdef PARANOID // Signal handler should call ThreadLocalStorage::get_thread_slow() Thread* t = ThreadLocalStorage::get_thread_slow(); assert(t != NULL && !t->is_inside_signal_handler(), "Don't use Thread::current() inside signal handler"); #endif #endif Thread* thread = ThreadLocalStorage::thread(); assert(thread != NULL, "just checking"); return thread; } // Name support for threads. non-JavaThread subclasses with multiple // uniquely named instances should derive from this. class NamedThread: public Thread { friend class VMStructs; enum { max_name_len = 64 }; private: char* _name; // log JavaThread being processed by oops_do JavaThread* _processed_thread; public: NamedThread(); ~NamedThread(); // May only be called once per thread. void set_name(const char* format, ...); virtual bool is_Named_thread() const { return true; } virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; } JavaThread *processed_thread() { return _processed_thread; } void set_processed_thread(JavaThread *thread) { _processed_thread = thread; } }; // Worker threads are named and have an id of an assigned work. class WorkerThread: public NamedThread { private: uint _id; public: WorkerThread() : _id(0) { } void set_id(uint work_id) { _id = work_id; } uint id() const { return _id; } }; // A single WatcherThread is used for simulating timer interrupts. class WatcherThread: public Thread { friend class VMStructs; public: virtual void run(); private: static WatcherThread* _watcher_thread; static bool _should_terminate; public: enum SomeConstants { delay_interval = 10 // interrupt delay in milliseconds }; // Constructor WatcherThread(); // Tester bool is_Watcher_thread() const { return true; } // Printing char* name() const { return (char*)"VM Periodic Task Thread"; } void print_on(outputStream* st) const; void print() const { print_on(tty); } // Returns the single instance of WatcherThread static WatcherThread* watcher_thread() { return _watcher_thread; } // Create and start the single instance of WatcherThread, or stop it on shutdown static void start(); static void stop(); }; class CompilerThread; typedef void (*ThreadFunction)(JavaThread*, TRAPS); class JavaThread: public Thread { friend class VMStructs; private: JavaThread* _next; // The next thread in the Threads list oop _threadObj; // The Java level thread object #ifdef ASSERT private: int _java_call_counter; public: int java_call_counter() { return _java_call_counter; } void inc_java_call_counter() { _java_call_counter++; } void dec_java_call_counter() { assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper"); _java_call_counter--; } private: // restore original namespace restriction #endif // ifdef ASSERT #ifndef PRODUCT public: enum { jump_ring_buffer_size = 16 }; private: // restore original namespace restriction #endif JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state ThreadFunction _entry_point; JNIEnv _jni_environment; // Deopt support DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we // transition out of native vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays vframeArray* _vframe_array_last; // Holds last vFrameArray we popped // Because deoptimization is lazy we must save jvmti requests to set locals // in compiled frames until we deoptimize and we have an interpreter frame. // This holds the pointer to array (yeah like there might be more than one) of // description of compiled vframes that have locals that need to be updated. GrowableArray* _deferred_locals_updates; // Handshake value for fixing 6243940. We need a place for the i2c // adapter to store the callee methodOop. This value is NEVER live // across a gc point so it does NOT have to be gc'd // The handshake is open ended since we can't be certain that it will // be NULLed. This is because we rarely ever see the race and end up // in handle_wrong_method which is the backend of the handshake. See // code in i2c adapters and handle_wrong_method. methodOop _callee_target; // Oop results of VM runtime calls oop _vm_result; // Used to pass back an oop result into Java code, GC-preserved oop _vm_result_2; // Used to pass back an oop result into Java code, GC-preserved // See ReduceInitialCardMarks: this holds the precise space interval of // the most recent slow path allocation for which compiled code has // elided card-marks for performance along the fast-path. MemRegion _deferred_card_mark; MonitorChunk* _monitor_chunks; // Contains the off stack monitors // allocated during deoptimization // and by JNI_MonitorEnter/Exit // Async. requests support enum AsyncRequests { _no_async_condition = 0, _async_exception, _async_unsafe_access_error }; AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request oop _pending_async_exception; // Safepoint support public: // Expose _thread_state for SafeFetchInt() volatile JavaThreadState _thread_state; private: ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened // JavaThread termination support enum TerminatedTypes { _not_terminated = 0xDEAD - 2, _thread_exiting, // JavaThread::exit() has been called for this thread _thread_terminated, // JavaThread is removed from thread list _vm_exited // JavaThread is still executing native code, but VM is terminated // only VM_Exit can set _vm_exited }; // In general a JavaThread's _terminated field transitions as follows: // // _not_terminated => _thread_exiting => _thread_terminated // // _vm_exited is a special value to cover the case of a JavaThread // executing native code after the VM itself is terminated. TerminatedTypes _terminated; // suspend/resume support volatile bool _suspend_equivalent; // Suspend equivalent condition jint _in_deopt_handler; // count of deoptimization // handlers thread is in volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was // never locked) when throwing an exception. Used by interpreter only. // Flag to mark a JNI thread in the process of attaching - See CR 6404306 // This flag is never set true other than at construction, and in that case // is shortly thereafter set false volatile bool _is_attaching; public: // State of the stack guard pages for this thread. enum StackGuardState { stack_guard_unused, // not needed stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow stack_guard_enabled // enabled }; private: StackGuardState _stack_guard_state; // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is // used to temp. parsing values into and out of the runtime system during exception handling for compiled // code) volatile oop _exception_oop; // Exception thrown in compiled code volatile address _exception_pc; // PC where exception happened volatile address _exception_handler_pc; // PC for handler of exception volatile int _exception_stack_size; // Size of frame where exception happened volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site. // support for compilation bool _is_compiling; // is true if a compilation is active inthis thread (one compilation per thread possible) // support for JNI critical regions jint _jni_active_critical; // count of entries into JNI critical region // For deadlock detection. int _depth_first_number; // JVMTI PopFrame support // This is set to popframe_pending to signal that top Java frame should be popped immediately int _popframe_condition; #ifndef PRODUCT int _jmp_ring_index; struct { // We use intptr_t instead of address so debugger doesn't try and display strings intptr_t _target; intptr_t _instruction; const char* _file; int _line; } _jmp_ring[ jump_ring_buffer_size ]; #endif /* PRODUCT */ #ifndef SERIALGC // Support for G1 barriers ObjPtrQueue _satb_mark_queue; // Thread-local log for SATB barrier. // Set of all such queues. static SATBMarkQueueSet _satb_mark_queue_set; DirtyCardQueue _dirty_card_queue; // Thread-local log for dirty cards. // Set of all such queues. static DirtyCardQueueSet _dirty_card_queue_set; void flush_barrier_queues(); #endif // !SERIALGC friend class VMThread; friend class ThreadWaitTransition; friend class VM_Exit; void initialize(); // Initialized the instance variables public: // Constructor JavaThread(bool is_attaching = false); // for main thread and JNI attached threads JavaThread(ThreadFunction entry_point, size_t stack_size = 0); ~JavaThread(); #ifdef ASSERT // verify this JavaThread hasn't be published in the Threads::list yet void verify_not_published(); #endif //JNI functiontable getter/setter for JVMTI jni function table interception API. void set_jni_functions(struct JNINativeInterface_* functionTable) { _jni_environment.functions = functionTable; } struct JNINativeInterface_* get_jni_functions() { return (struct JNINativeInterface_ *)_jni_environment.functions; } // Executes Shutdown.shutdown() void invoke_shutdown_hooks(); // Cleanup on thread exit enum ExitType { normal_exit, jni_detach }; void exit(bool destroy_vm, ExitType exit_type = normal_exit); void cleanup_failed_attach_current_thread(); // Testers virtual bool is_Java_thread() const { return true; } // compilation void set_is_compiling(bool f) { _is_compiling = f; } bool is_compiling() const { return _is_compiling; } // Thread chain operations JavaThread* next() const { return _next; } void set_next(JavaThread* p) { _next = p; } // Thread oop. threadObj() can be NULL for initial JavaThread // (or for threads attached via JNI) oop threadObj() const { return _threadObj; } void set_threadObj(oop p) { _threadObj = p; } ThreadPriority java_priority() const; // Read from threadObj() // Prepare thread and add to priority queue. If a priority is // not specified, use the priority of the thread object. Threads_lock // must be held while this function is called. void prepare(jobject jni_thread, ThreadPriority prio=NoPriority); void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; } address saved_exception_pc() { return _saved_exception_pc; } ThreadFunction entry_point() const { return _entry_point; } // Allocates a new Java level thread object for this thread. thread_name may be NULL. void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS); // Last frame anchor routines JavaFrameAnchor* frame_anchor(void) { return &_anchor; } // last_Java_sp bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); } intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); } // last_Java_pc address last_Java_pc(void) { return _anchor.last_Java_pc(); } // Safepoint support JavaThreadState thread_state() const { return _thread_state; } void set_thread_state(JavaThreadState s) { _thread_state=s; } ThreadSafepointState *safepoint_state() const { return _safepoint_state; } void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; } bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); } // thread has called JavaThread::exit() or is terminated bool is_exiting() { return _terminated == _thread_exiting || is_terminated(); } // thread is terminated (no longer on the threads list); we compare // against the two non-terminated values so that a freed JavaThread // will also be considered terminated. bool is_terminated() { return _terminated != _not_terminated && _terminated != _thread_exiting; } void set_terminated(TerminatedTypes t) { _terminated = t; } // special for Threads::remove() which is static: void set_terminated_value() { _terminated = _thread_terminated; } void block_if_vm_exited(); bool doing_unsafe_access() { return _doing_unsafe_access; } void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; } bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; } void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; } // Suspend/resume support for JavaThread private: void set_ext_suspended() { set_suspend_flag (_ext_suspended); } void clear_ext_suspended() { clear_suspend_flag(_ext_suspended); } public: void java_suspend(); void java_resume(); int java_suspend_self(); void check_and_wait_while_suspended() { assert(JavaThread::current() == this, "sanity check"); bool do_self_suspend; do { // were we externally suspended while we were waiting? do_self_suspend = handle_special_suspend_equivalent_condition(); if (do_self_suspend) { // don't surprise the thread that suspended us by returning java_suspend_self(); set_suspend_equivalent(); } } while (do_self_suspend); } static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread); // Check for async exception in addition to safepoint and suspend request. static void check_special_condition_for_native_trans(JavaThread *thread); bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits); bool is_ext_suspend_completed_with_lock(uint32_t *bits) { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); // Warning: is_ext_suspend_completed() may temporarily drop the // SR_lock to allow the thread to reach a stable thread state if // it is currently in a transient thread state. return is_ext_suspend_completed(false /*!called_by_wait */, SuspendRetryDelay, bits); } // We cannot allow wait_for_ext_suspend_completion() to run forever or // we could hang. SuspendRetryCount and SuspendRetryDelay are normally // passed as the count and delay parameters. Experiments with specific // calls to wait_for_ext_suspend_completion() can be done by passing // other values in the code. Experiments with all calls can be done // via the appropriate -XX options. bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits); void set_external_suspend() { set_suspend_flag (_external_suspend); } void clear_external_suspend() { clear_suspend_flag(_external_suspend); } void set_deopt_suspend() { set_suspend_flag (_deopt_suspend); } void clear_deopt_suspend() { clear_suspend_flag(_deopt_suspend); } bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; } bool is_external_suspend() const { return (_suspend_flags & _external_suspend) != 0; } // Whenever a thread transitions from native to vm/java it must suspend // if external|deopt suspend is present. bool is_suspend_after_native() const { return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0; } // external suspend request is completed bool is_ext_suspended() const { return (_suspend_flags & _ext_suspended) != 0; } bool is_external_suspend_with_lock() const { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); return is_external_suspend(); } // Special method to handle a pending external suspend request // when a suspend equivalent condition lifts. bool handle_special_suspend_equivalent_condition() { assert(is_suspend_equivalent(), "should only be called in a suspend equivalence condition"); MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); bool ret = is_external_suspend(); if (!ret) { // not about to self-suspend so clear suspend equivalence clear_suspend_equivalent(); } // implied else: // We have a pending external suspend request so we leave the // suspend_equivalent flag set until java_suspend_self() sets // the ext_suspended flag and clears the suspend_equivalent // flag. This insures that wait_for_ext_suspend_completion() // will return consistent values. return ret; } // utility methods to see if we are doing some kind of suspension bool is_being_ext_suspended() const { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); return is_ext_suspended() || is_external_suspend(); } bool is_suspend_equivalent() const { return _suspend_equivalent; } void set_suspend_equivalent() { _suspend_equivalent = true; }; void clear_suspend_equivalent() { _suspend_equivalent = false; }; // Thread.stop support void send_thread_stop(oop throwable); AsyncRequests clear_special_runtime_exit_condition() { AsyncRequests x = _special_runtime_exit_condition; _special_runtime_exit_condition = _no_async_condition; return x; } // Are any async conditions present? bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); } void check_and_handle_async_exceptions(bool check_unsafe_error = true); // these next two are also used for self-suspension and async exception support void handle_special_runtime_exit_condition(bool check_asyncs = true); // Return true if JavaThread has an asynchronous condition or // if external suspension is requested. bool has_special_runtime_exit_condition() { // We call is_external_suspend() last since external suspend should // be less common. Because we don't use is_external_suspend_with_lock // it is possible that we won't see an asynchronous external suspend // request that has just gotten started, i.e., SR_lock grabbed but // _external_suspend field change either not made yet or not visible // yet. However, this is okay because the request is asynchronous and // we will see the new flag value the next time through. It's also // possible that the external suspend request is dropped after // we have checked is_external_suspend(), we will recheck its value // under SR_lock in java_suspend_self(). return (_special_runtime_exit_condition != _no_async_condition) || is_external_suspend() || is_deopt_suspend(); } void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; } void set_pending_async_exception(oop e) { _pending_async_exception = e; _special_runtime_exit_condition = _async_exception; set_has_async_exception(); } // Fast-locking support bool is_lock_owned(address adr) const; // Accessors for vframe array top // The linked list of vframe arrays are sorted on sp. This means when we // unpack the head must contain the vframe array to unpack. void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; } vframeArray* vframe_array_head() const { return _vframe_array_head; } // Side structure for defering update of java frame locals until deopt occurs GrowableArray* deferred_locals() const { return _deferred_locals_updates; } void set_deferred_locals(GrowableArray* vf) { _deferred_locals_updates = vf; } // These only really exist to make debugging deopt problems simpler void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; } vframeArray* vframe_array_last() const { return _vframe_array_last; } // The special resourceMark used during deoptimization void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; } DeoptResourceMark* deopt_mark(void) { return _deopt_mark; } intptr_t* must_deopt_id() { return _must_deopt_id; } void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; } void clear_must_deopt_id() { _must_deopt_id = NULL; } methodOop callee_target() const { return _callee_target; } void set_callee_target (methodOop x) { _callee_target = x; } // Oop results of vm runtime calls oop vm_result() const { return _vm_result; } void set_vm_result (oop x) { _vm_result = x; } oop vm_result_2() const { return _vm_result_2; } void set_vm_result_2 (oop x) { _vm_result_2 = x; } MemRegion deferred_card_mark() const { return _deferred_card_mark; } void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; } // Exception handling for compiled methods oop exception_oop() const { return _exception_oop; } int exception_stack_size() const { return _exception_stack_size; } address exception_pc() const { return _exception_pc; } address exception_handler_pc() const { return _exception_handler_pc; } bool is_method_handle_return() const { return _is_method_handle_return == 1; } void set_exception_oop(oop o) { _exception_oop = o; } void set_exception_pc(address a) { _exception_pc = a; } void set_exception_handler_pc(address a) { _exception_handler_pc = a; } void set_exception_stack_size(int size) { _exception_stack_size = size; } void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; } // Stack overflow support inline size_t stack_available(address cur_sp); address stack_yellow_zone_base() { return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); } size_t stack_yellow_zone_size() { return StackYellowPages * os::vm_page_size(); } address stack_red_zone_base() { return (address)(stack_base() - (stack_size() - stack_red_zone_size())); } size_t stack_red_zone_size() { return StackRedPages * os::vm_page_size(); } bool in_stack_yellow_zone(address a) { return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); } bool in_stack_red_zone(address a) { return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); } void create_stack_guard_pages(); void remove_stack_guard_pages(); void enable_stack_yellow_zone(); void disable_stack_yellow_zone(); void enable_stack_red_zone(); void disable_stack_red_zone(); inline bool stack_yellow_zone_disabled(); inline bool stack_yellow_zone_enabled(); // Attempt to reguard the stack after a stack overflow may have occurred. // Returns true if (a) guard pages are not needed on this thread, (b) the // pages are already guarded, or (c) the pages were successfully reguarded. // Returns false if there is not enough stack space to reguard the pages, in // which case the caller should unwind a frame and try again. The argument // should be the caller's (approximate) sp. bool reguard_stack(address cur_sp); // Similar to above but see if current stackpoint is out of the guard area // and reguard if possible. bool reguard_stack(void); // Misc. accessors/mutators void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; } void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; } bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; } #ifndef PRODUCT void record_jump(address target, address instr, const char* file, int line); #endif /* PRODUCT */ // For assembly stub generation static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj ); } #ifndef PRODUCT static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index ); } static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring ); } #endif /* PRODUCT */ static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment ); } static ByteSize last_Java_sp_offset() { return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset(); } static ByteSize last_Java_pc_offset() { return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset(); } static ByteSize frame_anchor_offset() { return byte_offset_of(JavaThread, _anchor); } static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target ); } static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result ); } static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2 ); } static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state ); } static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc ); } static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread ); } static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop ); } static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc ); } static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); } static ByteSize exception_stack_size_offset() { return byte_offset_of(JavaThread, _exception_stack_size); } static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); } static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state ); } static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags ); } static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); } static ByteSize should_post_on_exceptions_flag_offset() { return byte_offset_of(JavaThread, _should_post_on_exceptions_flag); } #ifndef SERIALGC static ByteSize satb_mark_queue_offset() { return byte_offset_of(JavaThread, _satb_mark_queue); } static ByteSize dirty_card_queue_offset() { return byte_offset_of(JavaThread, _dirty_card_queue); } #endif // !SERIALGC // Returns the jni environment for this thread JNIEnv* jni_environment() { return &_jni_environment; } static JavaThread* thread_from_jni_environment(JNIEnv* env) { JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset())); // Only return NULL if thread is off the thread list; starting to // exit should not return NULL. if (thread_from_jni_env->is_terminated()) { thread_from_jni_env->block_if_vm_exited(); return NULL; } else { return thread_from_jni_env; } } // JNI critical regions. These can nest. bool in_critical() { return _jni_active_critical > 0; } void enter_critical() { assert(Thread::current() == this, "this must be current thread"); _jni_active_critical++; } void exit_critical() { assert(Thread::current() == this, "this must be current thread"); _jni_active_critical--; assert(_jni_active_critical >= 0, "JNI critical nesting problem?"); } // For deadlock detection int depth_first_number() { return _depth_first_number; } void set_depth_first_number(int dfn) { _depth_first_number = dfn; } private: void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; } public: MonitorChunk* monitor_chunks() const { return _monitor_chunks; } void add_monitor_chunk(MonitorChunk* chunk); void remove_monitor_chunk(MonitorChunk* chunk); bool in_deopt_handler() const { return _in_deopt_handler > 0; } void inc_in_deopt_handler() { _in_deopt_handler++; } void dec_in_deopt_handler() { assert(_in_deopt_handler > 0, "mismatched deopt nesting"); if (_in_deopt_handler > 0) { // robustness _in_deopt_handler--; } } private: void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; } public: // Frame iteration; calls the function f for all frames on the stack void frames_do(void f(frame*, const RegisterMap*)); // Memory operations void oops_do(OopClosure* f, CodeBlobClosure* cf); // Sweeper operations void nmethods_do(CodeBlobClosure* cf); // Memory management operations void gc_epilogue(); void gc_prologue(); // Misc. operations char* name() const { return (char*)get_thread_name(); } void print_on(outputStream* st) const; void print() const { print_on(tty); } void print_value(); void print_thread_state_on(outputStream* ) const PRODUCT_RETURN; void print_thread_state() const PRODUCT_RETURN; void print_on_error(outputStream* st, char* buf, int buflen) const; void verify(); const char* get_thread_name() const; private: // factor out low-level mechanics for use in both normal and error cases const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const; public: const char* get_threadgroup_name() const; const char* get_parent_name() const; // Accessing frames frame last_frame() { _anchor.make_walkable(this); return pd_last_frame(); } javaVFrame* last_java_vframe(RegisterMap* reg_map); // Returns method at 'depth' java or native frames down the stack // Used for security checks klassOop security_get_caller_class(int depth); // Print stack trace in external format void print_stack_on(outputStream* st); void print_stack() { print_stack_on(tty); } // Print stack traces in various internal formats void trace_stack() PRODUCT_RETURN; void trace_stack_from(vframe* start_vf) PRODUCT_RETURN; void trace_frames() PRODUCT_RETURN; // Returns the number of stack frames on the stack int depth() const; // Function for testing deoptimization void deoptimize(); void make_zombies(); void deoptimized_wrt_marked_nmethods(); // Profiling operation (see fprofile.cpp) public: bool profile_last_Java_frame(frame* fr); private: ThreadProfiler* _thread_profiler; private: friend class FlatProfiler; // uses both [gs]et_thread_profiler. friend class FlatProfilerTask; // uses get_thread_profiler. friend class ThreadProfilerMark; // uses get_thread_profiler. ThreadProfiler* get_thread_profiler() { return _thread_profiler; } ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) { ThreadProfiler* result = _thread_profiler; _thread_profiler = tp; return result; } // Static operations public: // Returns the running thread as a JavaThread static inline JavaThread* current(); // Returns the active Java thread. Do not use this if you know you are calling // from a JavaThread, as it's slower than JavaThread::current. If called from // the VMThread, it also returns the JavaThread that instigated the VMThread's // operation. You may not want that either. static JavaThread* active(); inline CompilerThread* as_CompilerThread(); public: virtual void run(); void thread_main_inner(); private: // PRIVILEGED STACK PrivilegedElement* _privileged_stack_top; GrowableArray* _array_for_gc; public: // Returns the privileged_stack information. PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; } void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; } void register_array_for_gc(GrowableArray* array) { _array_for_gc = array; } public: // Thread local information maintained by JVMTI. void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; } // A JvmtiThreadState is lazily allocated. This jvmti_thread_state() // getter is used to get this JavaThread's JvmtiThreadState if it has // one which means NULL can be returned. JvmtiThreadState::state_for() // is used to get the specified JavaThread's JvmtiThreadState if it has // one or it allocates a new JvmtiThreadState for the JavaThread and // returns it. JvmtiThreadState::state_for() will return NULL only if // the specified JavaThread is exiting. JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; } static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); } void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; } JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; } // JVMTI PopFrame support // Setting and clearing popframe_condition // All of these enumerated values are bits. popframe_pending // indicates that a PopFrame() has been requested and not yet been // completed. popframe_processing indicates that that PopFrame() is in // the process of being completed. popframe_force_deopt_reexecution_bit // indicates that special handling is required when returning to a // deoptimized caller. enum PopCondition { popframe_inactive = 0x00, popframe_pending_bit = 0x01, popframe_processing_bit = 0x02, popframe_force_deopt_reexecution_bit = 0x04 }; PopCondition popframe_condition() { return (PopCondition) _popframe_condition; } void set_popframe_condition(PopCondition c) { _popframe_condition = c; } void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; } void clear_popframe_condition() { _popframe_condition = popframe_inactive; } static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); } bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; } bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; } void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; } #ifdef CC_INTERP bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); } void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; } bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); } void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; } void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; } #endif private: // Saved incoming arguments to popped frame. // Used only when popped interpreted frame returns to deoptimized frame. void* _popframe_preserved_args; int _popframe_preserved_args_size; public: void popframe_preserve_args(ByteSize size_in_bytes, void* start); void* popframe_preserved_args(); ByteSize popframe_preserved_args_size(); WordSize popframe_preserved_args_size_in_words(); void popframe_free_preserved_args(); private: JvmtiThreadState *_jvmti_thread_state; JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure; // Used by the interpreter in fullspeed mode for frame pop, method // entry, method exit and single stepping support. This field is // only set to non-zero by the VM_EnterInterpOnlyMode VM operation. // It can be set to zero asynchronously (i.e., without a VM operation // or a lock) so we have to be very careful. int _interp_only_mode; public: // used by the interpreter for fullspeed debugging support (see above) static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); } bool is_interp_only_mode() { return (_interp_only_mode != 0); } int get_interp_only_mode() { return _interp_only_mode; } void increment_interp_only_mode() { ++_interp_only_mode; } void decrement_interp_only_mode() { --_interp_only_mode; } // support for cached flag that indicates whether exceptions need to be posted for this thread // if this is false, we can avoid deoptimizing when events are thrown // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything private: int _should_post_on_exceptions_flag; public: int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; } void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; } private: ThreadStatistics *_thread_stat; public: ThreadStatistics* get_thread_stat() const { return _thread_stat; } // Return a blocker object for which this thread is blocked parking. oop current_park_blocker(); private: static size_t _stack_size_at_create; public: static inline size_t stack_size_at_create(void) { return _stack_size_at_create; } static inline void set_stack_size_at_create(size_t value) { _stack_size_at_create = value; } #ifndef SERIALGC // SATB marking queue support ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; } static SATBMarkQueueSet& satb_mark_queue_set() { return _satb_mark_queue_set; } // Dirty card queue support DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; } static DirtyCardQueueSet& dirty_card_queue_set() { return _dirty_card_queue_set; } #endif // !SERIALGC // Machine dependent stuff #include "incls/_thread_pd.hpp.incl" public: void set_blocked_on_compilation(bool value) { _blocked_on_compilation = value; } bool blocked_on_compilation() { return _blocked_on_compilation; } protected: bool _blocked_on_compilation; // JSR166 per-thread parker private: Parker* _parker; public: Parker* parker() { return _parker; } // Biased locking support private: GrowableArray* _cached_monitor_info; public: GrowableArray* cached_monitor_info() { return _cached_monitor_info; } void set_cached_monitor_info(GrowableArray* info) { _cached_monitor_info = info; } // clearing/querying jni attach status bool is_attaching() const { return _is_attaching; } void set_attached() { _is_attaching = false; OrderAccess::fence(); } private: // This field is used to determine if a thread has claimed // a par_id: it is -1 if the thread has not claimed a par_id; // otherwise its value is the par_id that has been claimed. int _claimed_par_id; public: int get_claimed_par_id() { return _claimed_par_id; } void set_claimed_par_id(int id) { _claimed_par_id = id;} }; // Inline implementation of JavaThread::current inline JavaThread* JavaThread::current() { Thread* thread = ThreadLocalStorage::thread(); assert(thread != NULL && thread->is_Java_thread(), "just checking"); return (JavaThread*)thread; } inline CompilerThread* JavaThread::as_CompilerThread() { assert(is_Compiler_thread(), "just checking"); return (CompilerThread*)this; } inline bool JavaThread::stack_yellow_zone_disabled() { return _stack_guard_state == stack_guard_yellow_disabled; } inline bool JavaThread::stack_yellow_zone_enabled() { #ifdef ASSERT if (os::uses_stack_guard_pages()) { assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use"); } #endif return _stack_guard_state == stack_guard_enabled; } inline size_t JavaThread::stack_available(address cur_sp) { // This code assumes java stacks grow down address low_addr; // Limit on the address for deepest stack depth if ( _stack_guard_state == stack_guard_unused) { low_addr = stack_base() - stack_size(); } else { low_addr = stack_yellow_zone_base(); } return cur_sp > low_addr ? cur_sp - low_addr : 0; } // A JavaThread for low memory detection support class LowMemoryDetectorThread : public JavaThread { friend class VMStructs; public: LowMemoryDetectorThread(ThreadFunction entry_point) : JavaThread(entry_point) {}; // Hide this thread from external view. bool is_hidden_from_external_view() const { return true; } }; // A thread used for Compilation. class CompilerThread : public JavaThread { friend class VMStructs; private: CompilerCounters* _counters; ciEnv* _env; CompileLog* _log; CompileTask* _task; CompileQueue* _queue; BufferBlob* _buffer_blob; public: static CompilerThread* current(); CompilerThread(CompileQueue* queue, CompilerCounters* counters); bool is_Compiler_thread() const { return true; } // Hide this compiler thread from external view. bool is_hidden_from_external_view() const { return true; } CompileQueue* queue() { return _queue; } CompilerCounters* counters() { return _counters; } // Get/set the thread's compilation environment. ciEnv* env() { return _env; } void set_env(ciEnv* env) { _env = env; } BufferBlob* get_buffer_blob() { return _buffer_blob; } void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }; // Get/set the thread's logging information CompileLog* log() { return _log; } void init_log(CompileLog* log) { // Set once, for good. assert(_log == NULL, "set only once"); _log = log; } #ifndef PRODUCT private: IdealGraphPrinter *_ideal_graph_printer; public: IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; } void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; } #endif // Get/set the thread's current task CompileTask* task() { return _task; } void set_task(CompileTask* task) { _task = task; } }; inline CompilerThread* CompilerThread::current() { return JavaThread::current()->as_CompilerThread(); } // The active thread queue. It also keeps track of the current used // thread priorities. class Threads: AllStatic { friend class VMStructs; private: static JavaThread* _thread_list; static int _number_of_threads; static int _number_of_non_daemon_threads; static int _return_code; public: // Thread management // force_daemon is a concession to JNI, where we may need to add a // thread to the thread list before allocating its thread object static void add(JavaThread* p, bool force_daemon = false); static void remove(JavaThread* p); static bool includes(JavaThread* p); static JavaThread* first() { return _thread_list; } static void threads_do(ThreadClosure* tc); // Initializes the vm and creates the vm thread static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain); static void convert_vm_init_libraries_to_agents(); static void create_vm_init_libraries(); static void create_vm_init_agents(); static void shutdown_vm_agents(); static bool destroy_vm(); // Supported VM versions via JNI // Includes JNI_VERSION_1_1 static jboolean is_supported_jni_version_including_1_1(jint version); // Does not include JNI_VERSION_1_1 static jboolean is_supported_jni_version(jint version); // Garbage collection static void follow_other_roots(void f(oop*)); // Apply "f->do_oop" to all root oops in all threads. // This version may only be called by sequential code. static void oops_do(OopClosure* f, CodeBlobClosure* cf); // This version may be called by sequential or parallel code. static void possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf); // This creates a list of GCTasks, one per thread. static void create_thread_roots_tasks(GCTaskQueue* q); // This creates a list of GCTasks, one per thread, for marking objects. static void create_thread_roots_marking_tasks(GCTaskQueue* q); // Apply "f->do_oop" to roots in all threads that // are part of compiled frames static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf); static void convert_hcode_pointers(); static void restore_hcode_pointers(); // Sweeper static void nmethods_do(CodeBlobClosure* cf); static void gc_epilogue(); static void gc_prologue(); // Verification static void verify(); static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks); static void print(bool print_stacks, bool internal_format) { // this function is only used by debug.cpp print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */); } static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen); // Get Java threads that are waiting to enter a monitor. If doLock // is true, then Threads_lock is grabbed as needed. Otherwise, the // VM needs to be at a safepoint. static GrowableArray* get_pending_threads(int count, address monitor, bool doLock); // Get owning Java thread from the monitor's owner field. If doLock // is true, then Threads_lock is grabbed as needed. Otherwise, the // VM needs to be at a safepoint. static JavaThread *owning_thread_from_monitor_owner(address owner, bool doLock); // Number of threads on the active threads list static int number_of_threads() { return _number_of_threads; } // Number of non-daemon threads on the active threads list static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; } // Deoptimizes all frames tied to marked nmethods static void deoptimized_wrt_marked_nmethods(); }; // Thread iterator class ThreadClosure: public StackObj { public: virtual void do_thread(Thread* thread) = 0; }; class SignalHandlerMark: public StackObj { private: Thread* _thread; public: SignalHandlerMark(Thread* t) { _thread = t; if (_thread) _thread->enter_signal_handler(); } ~SignalHandlerMark() { if (_thread) _thread->leave_signal_handler(); _thread = NULL; } }; // ParkEvents are type-stable and immortal. // // Lifecycle: Once a ParkEvent is associated with a thread that ParkEvent remains // associated with the thread for the thread's entire lifetime - the relationship is // stable. A thread will be associated at most one ParkEvent. When the thread // expires, the ParkEvent moves to the EventFreeList. New threads attempt to allocate from // the EventFreeList before creating a new Event. Type-stability frees us from // worrying about stale Event or Thread references in the objectMonitor subsystem. // (A reference to ParkEvent is always valid, even though the event may no longer be associated // with the desired or expected thread. A key aspect of this design is that the callers of // park, unpark, etc must tolerate stale references and spurious wakeups). // // Only the "associated" thread can block (park) on the ParkEvent, although // any other thread can unpark a reachable parkevent. Park() is allowed to // return spuriously. In fact park-unpark a really just an optimization to // avoid unbounded spinning and surrender the CPU to be a polite system citizen. // A degenerate albeit "impolite" park-unpark implementation could simply return. // See http://blogs.sun.com/dave for more details. // // Eventually I'd like to eliminate Events and ObjectWaiters, both of which serve as // thread proxies, and simply make the THREAD structure type-stable and persistent. // Currently, we unpark events associated with threads, but ideally we'd just // unpark threads. // // The base-class, PlatformEvent, is platform-specific while the ParkEvent is // platform-independent. PlatformEvent provides park(), unpark(), etc., and // is abstract -- that is, a PlatformEvent should never be instantiated except // as part of a ParkEvent. // Equivalently we could have defined a platform-independent base-class that // exported Allocate(), Release(), etc. The platform-specific class would extend // that base-class, adding park(), unpark(), etc. // // A word of caution: The JVM uses 2 very similar constructs: // 1. ParkEvent are used for Java-level "monitor" synchronization. // 2. Parkers are used by JSR166-JUC park-unpark. // // We'll want to eventually merge these redundant facilities and use ParkEvent. class ParkEvent : public os::PlatformEvent { private: ParkEvent * FreeNext ; // Current association Thread * AssociatedWith ; intptr_t RawThreadIdentity ; // LWPID etc volatile int Incarnation ; // diagnostic : keep track of last thread to wake this thread. // this is useful for construction of dependency graphs. void * LastWaker ; public: // MCS-CLH list linkage and Native Mutex/Monitor ParkEvent * volatile ListNext ; ParkEvent * volatile ListPrev ; volatile intptr_t OnList ; volatile int TState ; volatile int Notified ; // for native monitor construct volatile int IsWaiting ; // Enqueued on WaitSet private: static ParkEvent * volatile FreeList ; static volatile int ListLock ; // It's prudent to mark the dtor as "private" // ensuring that it's not visible outside the package. // Unfortunately gcc warns about such usage, so // we revert to the less desirable "protected" visibility. // The other compilers accept private dtors. protected: // Ensure dtor is never invoked ~ParkEvent() { guarantee (0, "invariant") ; } ParkEvent() : PlatformEvent() { AssociatedWith = NULL ; FreeNext = NULL ; ListNext = NULL ; ListPrev = NULL ; OnList = 0 ; TState = 0 ; Notified = 0 ; IsWaiting = 0 ; } // We use placement-new to force ParkEvent instances to be // aligned on 256-byte address boundaries. This ensures that the least // significant byte of a ParkEvent address is always 0. void * operator new (size_t sz) ; void operator delete (void * a) ; public: static ParkEvent * Allocate (Thread * t) ; static void Release (ParkEvent * e) ; } ;