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5 * This code is free software; you can redistribute it and/or modify it
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25 # include "incls/_precompiled.incl"
26 # include "incls/_thread.cpp.incl"
30 // Only bother with this argument setup if dtrace is available
32 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin);
33 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end);
34 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t,
35 intptr_t, intptr_t, bool);
36 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t,
37 intptr_t, intptr_t, bool);
39 #define DTRACE_THREAD_PROBE(probe, javathread) \
41 ResourceMark rm(this); \
43 const char* name = (javathread)->get_thread_name(); \
45 HS_DTRACE_PROBE5(hotspot, thread__##probe, \
47 java_lang_Thread::thread_id((javathread)->threadObj()), \
48 (javathread)->osthread()->thread_id(), \
49 java_lang_Thread::is_daemon((javathread)->threadObj())); \
52 #else // ndef DTRACE_ENABLED
54 #define DTRACE_THREAD_PROBE(probe, javathread)
56 #endif // ndef DTRACE_ENABLED
62 // - ConcurrentMarkSweepThread
66 // ======= Thread ========
68 // Support for forcing alignment of thread objects for biased locking
69 void* Thread::operator new(size_t size) {
70 if (UseBiasedLocking) {
71 const int alignment = markOopDesc::biased_lock_alignment;
72 size_t aligned_size = size + (alignment - sizeof(intptr_t));
73 void* real_malloc_addr = CHeapObj::operator new(aligned_size);
74 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment);
75 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
76 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
77 "JavaThread alignment code overflowed allocated storage");
78 if (TraceBiasedLocking) {
79 if (aligned_addr != real_malloc_addr)
80 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
81 real_malloc_addr, aligned_addr);
83 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
86 return CHeapObj::operator new(size);
90 void Thread::operator delete(void* p) {
91 if (UseBiasedLocking) {
92 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
93 CHeapObj::operator delete(real_malloc_addr);
95 CHeapObj::operator delete(p);
100 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
112 // allocated data structures
113 set_resource_area(new ResourceArea());
114 set_handle_area(new HandleArea(NULL));
115 set_active_handles(NULL);
116 set_free_handle_block(NULL);
117 set_last_handle_mark(NULL);
120 // This initial value ==> never claimed.
123 // the handle mark links itself to last_handle_mark
124 new HandleMark(this);
126 // plain initialization
127 debug_only(_owned_locks = NULL;)
128 debug_only(_allow_allocation_count = 0;)
129 NOT_PRODUCT(_allow_safepoint_count = 0;)
130 NOT_PRODUCT(_skip_gcalot = false;)
131 CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;)
132 _jvmti_env_iteration_count = 0;
133 _vm_operation_started_count = 0;
134 _vm_operation_completed_count = 0;
135 _current_pending_monitor = NULL;
136 _current_pending_monitor_is_from_java = true;
137 _current_waiting_monitor = NULL;
138 _num_nested_signal = 0;
141 omFreeProvision = 32 ;
143 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
146 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
147 _hashStateX = os::random() ;
148 _hashStateY = 842502087 ;
149 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
150 _hashStateW = 273326509 ;
157 // Many of the following fields are effectively final - immutable
158 // Note that nascent threads can't use the Native Monitor-Mutex
159 // construct until the _MutexEvent is initialized ...
160 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
161 // we might instead use a stack of ParkEvents that we could provision on-demand.
162 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
164 _ParkEvent = ParkEvent::Allocate (this) ;
165 _SleepEvent = ParkEvent::Allocate (this) ;
166 _MutexEvent = ParkEvent::Allocate (this) ;
167 _MuxEvent = ParkEvent::Allocate (this) ;
169 #ifdef CHECK_UNHANDLED_OOPS
170 if (CheckUnhandledOops) {
171 _unhandled_oops = new UnhandledOops(this);
173 #endif // CHECK_UNHANDLED_OOPS
175 if (UseBiasedLocking) {
176 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
177 assert(this == _real_malloc_address ||
178 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
179 "bug in forced alignment of thread objects");
184 void Thread::initialize_thread_local_storage() {
185 // Note: Make sure this method only calls
186 // non-blocking operations. Otherwise, it might not work
187 // with the thread-startup/safepoint interaction.
189 // During Java thread startup, safepoint code should allow this
190 // method to complete because it may need to allocate memory to
191 // store information for the new thread.
193 // initialize structure dependent on thread local storage
194 ThreadLocalStorage::set_thread(this);
196 // set up any platform-specific state.
197 os::initialize_thread();
201 void Thread::record_stack_base_and_size() {
202 set_stack_base(os::current_stack_base());
203 set_stack_size(os::current_stack_size());
208 // Reclaim the objectmonitors from the omFreeList of the moribund thread.
209 ObjectSynchronizer::omFlush (this) ;
211 // deallocate data structures
212 delete resource_area();
213 // since the handle marks are using the handle area, we have to deallocated the root
214 // handle mark before deallocating the thread's handle area,
215 assert(last_handle_mark() != NULL, "check we have an element");
216 delete last_handle_mark();
217 assert(last_handle_mark() == NULL, "check we have reached the end");
219 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
220 // We NULL out the fields for good hygiene.
221 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
222 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
223 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
224 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
226 delete handle_area();
228 // osthread() can be NULL, if creation of thread failed.
229 if (osthread() != NULL) os::free_thread(osthread());
233 // clear thread local storage if the Thread is deleting itself
234 if (this == Thread::current()) {
235 ThreadLocalStorage::set_thread(NULL);
237 // In the case where we're not the current thread, invalidate all the
238 // caches in case some code tries to get the current thread or the
239 // thread that was destroyed, and gets stale information.
240 ThreadLocalStorage::invalidate_all();
242 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
245 // NOTE: dummy function for assertion purpose.
247 ShouldNotReachHere();
251 // Private method to check for dangling thread pointer
252 void check_for_dangling_thread_pointer(Thread *thread) {
253 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
254 "possibility of dangling Thread pointer");
260 // Tracing method for basic thread operations
261 void Thread::trace(const char* msg, const Thread* const thread) {
262 if (!TraceThreadEvents) return;
265 const char *name = "non-Java thread";
267 if (thread->is_Java_thread()
268 && !thread->is_Compiler_thread()) {
269 // The Threads_lock must be held to get information about
270 // this thread but may not be in some situations when
271 // tracing thread events.
272 bool release_Threads_lock = false;
273 if (!Threads_lock->owned_by_self()) {
274 Threads_lock->lock();
275 release_Threads_lock = true;
277 JavaThread* jt = (JavaThread *)thread;
278 name = (char *)jt->get_thread_name();
279 oop thread_oop = jt->threadObj();
280 if (thread_oop != NULL) {
281 prio = java_lang_Thread::priority(thread_oop);
283 if (release_Threads_lock) {
284 Threads_lock->unlock();
287 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
292 ThreadPriority Thread::get_priority(const Thread* const thread) {
293 trace("get priority", thread);
294 ThreadPriority priority;
295 // Can return an error!
296 (void)os::get_priority(thread, priority);
297 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
301 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
302 trace("set priority", thread);
303 debug_only(check_for_dangling_thread_pointer(thread);)
304 // Can return an error!
305 (void)os::set_priority(thread, priority);
309 void Thread::start(Thread* thread) {
310 trace("start", thread);
311 // Start is different from resume in that its safety is guaranteed by context or
312 // being called from a Java method synchronized on the Thread object.
313 if (!DisableStartThread) {
314 if (thread->is_Java_thread()) {
315 // Initialize the thread state to RUNNABLE before starting this thread.
316 // Can not set it after the thread started because we do not know the
317 // exact thread state at that time. It could be in MONITOR_WAIT or
318 // in SLEEPING or some other state.
319 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
320 java_lang_Thread::RUNNABLE);
322 os::start_thread(thread);
326 // Enqueue a VM_Operation to do the job for us - sometime later
327 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
328 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
329 VMThread::execute(vm_stop);
334 // Check if an external suspend request has completed (or has been
335 // cancelled). Returns true if the thread is externally suspended and
338 // The bits parameter returns information about the code path through
339 // the routine. Useful for debugging:
341 // set in is_ext_suspend_completed():
342 // 0x00000001 - routine was entered
343 // 0x00000010 - routine return false at end
344 // 0x00000100 - thread exited (return false)
345 // 0x00000200 - suspend request cancelled (return false)
346 // 0x00000400 - thread suspended (return true)
347 // 0x00001000 - thread is in a suspend equivalent state (return true)
348 // 0x00002000 - thread is native and walkable (return true)
349 // 0x00004000 - thread is native_trans and walkable (needed retry)
351 // set in wait_for_ext_suspend_completion():
352 // 0x00010000 - routine was entered
353 // 0x00020000 - suspend request cancelled before loop (return false)
354 // 0x00040000 - thread suspended before loop (return true)
355 // 0x00080000 - suspend request cancelled in loop (return false)
356 // 0x00100000 - thread suspended in loop (return true)
357 // 0x00200000 - suspend not completed during retry loop (return false)
360 // Helper class for tracing suspend wait debug bits.
362 // 0x00000100 indicates that the target thread exited before it could
363 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
364 // 0x00080000 each indicate a cancelled suspend request so they don't
365 // count as wait failures either.
366 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
368 class TraceSuspendDebugBits : public StackObj {
372 bool called_by_wait; // meaningful when !is_wait
376 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
380 called_by_wait = _called_by_wait;
384 ~TraceSuspendDebugBits() {
387 // By default, don't trace bits for is_ext_suspend_completed() calls.
388 // That trace is very chatty.
391 if (!called_by_wait) {
392 // If tracing for is_ext_suspend_completed() is enabled, then only
393 // trace calls to it from wait_for_ext_suspend_completion()
399 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
400 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
401 MutexLocker ml(Threads_lock); // needed for get_thread_name()
405 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
406 jt->get_thread_name(), *bits);
408 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
413 #undef DEBUG_FALSE_BITS
416 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
417 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
419 bool did_trans_retry = false; // only do thread_in_native_trans retry once
420 bool do_trans_retry; // flag to force the retry
425 do_trans_retry = false;
428 // Thread is in the process of exiting. This is always checked
429 // first to reduce the risk of dereferencing a freed JavaThread.
434 if (!is_external_suspend()) {
435 // Suspend request is cancelled. This is always checked before
436 // is_ext_suspended() to reduce the risk of a rogue resume
437 // confusing the thread that made the suspend request.
442 if (is_ext_suspended()) {
443 // thread is suspended
448 // Now that we no longer do hard suspends of threads running
449 // native code, the target thread can be changing thread state
450 // while we are in this routine:
452 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
454 // We save a copy of the thread state as observed at this moment
455 // and make our decision about suspend completeness based on the
456 // copy. This closes the race where the thread state is seen as
457 // _thread_in_native_trans in the if-thread_blocked check, but is
458 // seen as _thread_blocked in if-thread_in_native_trans check.
459 JavaThreadState save_state = thread_state();
461 if (save_state == _thread_blocked && is_suspend_equivalent()) {
462 // If the thread's state is _thread_blocked and this blocking
463 // condition is known to be equivalent to a suspend, then we can
464 // consider the thread to be externally suspended. This means that
465 // the code that sets _thread_blocked has been modified to do
466 // self-suspension if the blocking condition releases. We also
467 // used to check for CONDVAR_WAIT here, but that is now covered by
468 // the _thread_blocked with self-suspension check.
470 // Return true since we wouldn't be here unless there was still an
471 // external suspend request.
474 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
475 // Threads running native code will self-suspend on native==>VM/Java
476 // transitions. If its stack is walkable (should always be the case
477 // unless this function is called before the actual java_suspend()
478 // call), then the wait is done.
481 } else if (!called_by_wait && !did_trans_retry &&
482 save_state == _thread_in_native_trans &&
483 frame_anchor()->walkable()) {
484 // The thread is transitioning from thread_in_native to another
485 // thread state. check_safepoint_and_suspend_for_native_trans()
486 // will force the thread to self-suspend. If it hasn't gotten
487 // there yet we may have caught the thread in-between the native
488 // code check above and the self-suspend. Lucky us. If we were
489 // called by wait_for_ext_suspend_completion(), then it
490 // will be doing the retries so we don't have to.
492 // Since we use the saved thread state in the if-statement above,
493 // there is a chance that the thread has already transitioned to
494 // _thread_blocked by the time we get here. In that case, we will
495 // make a single unnecessary pass through the logic below. This
496 // doesn't hurt anything since we still do the trans retry.
500 // Once the thread leaves thread_in_native_trans for another
501 // thread state, we break out of this retry loop. We shouldn't
502 // need this flag to prevent us from getting back here, but
503 // sometimes paranoia is good.
504 did_trans_retry = true;
506 // We wait for the thread to transition to a more usable state.
507 for (int i = 1; i <= SuspendRetryCount; i++) {
508 // We used to do an "os::yield_all(i)" call here with the intention
509 // that yielding would increase on each retry. However, the parameter
510 // is ignored on Linux which means the yield didn't scale up. Waiting
511 // on the SR_lock below provides a much more predictable scale up for
512 // the delay. It also provides a simple/direct point to check for any
513 // safepoint requests from the VMThread
515 // temporarily drops SR_lock while doing wait with safepoint check
516 // (if we're a JavaThread - the WatcherThread can also call this)
517 // and increase delay with each retry
518 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
520 // check the actual thread state instead of what we saved above
521 if (thread_state() != _thread_in_native_trans) {
522 // the thread has transitioned to another thread state so
523 // try all the checks (except this one) one more time.
524 do_trans_retry = true;
531 } while (do_trans_retry);
538 // Wait for an external suspend request to complete (or be cancelled).
539 // Returns true if the thread is externally suspended and false otherwise.
541 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
543 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
544 false /* !called_by_wait */, bits);
546 // local flag copies to minimize SR_lock hold time
551 // set a marker so is_ext_suspend_completed() knows we are the caller
554 // We use reset_bits to reinitialize the bits value at the top of
555 // each retry loop. This allows the caller to make use of any
556 // unused bits for their own marking purposes.
560 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
561 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
563 pending = is_external_suspend();
565 // must release SR_lock to allow suspension to complete
568 // A cancelled suspend request is the only false return from
569 // is_ext_suspend_completed() that keeps us from entering the
580 for (int i = 1; i <= retries; i++) {
581 *bits = reset_bits; // reinit to only track last retry
583 // We used to do an "os::yield_all(i)" call here with the intention
584 // that yielding would increase on each retry. However, the parameter
585 // is ignored on Linux which means the yield didn't scale up. Waiting
586 // on the SR_lock below provides a much more predictable scale up for
587 // the delay. It also provides a simple/direct point to check for any
588 // safepoint requests from the VMThread
591 MutexLocker ml(SR_lock());
592 // wait with safepoint check (if we're a JavaThread - the WatcherThread
593 // can also call this) and increase delay with each retry
594 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
596 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
599 // It is possible for the external suspend request to be cancelled
600 // (by a resume) before the actual suspend operation is completed.
601 // Refresh our local copy to see if we still need to wait.
602 pending = is_external_suspend();
606 // A cancelled suspend request is the only false return from
607 // is_ext_suspend_completed() that keeps us from staying in the
619 // thread did not suspend after all our retries
625 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
627 // This should not need to be atomic as the only way for simultaneous
628 // updates is via interrupts. Even then this should be rare or non-existant
629 // and we don't care that much anyway.
631 int index = _jmp_ring_index;
632 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
633 _jmp_ring[index]._target = (intptr_t) target;
634 _jmp_ring[index]._instruction = (intptr_t) instr;
635 _jmp_ring[index]._file = file;
636 _jmp_ring[index]._line = line;
640 // Called by flat profiler
641 // Callers have already called wait_for_ext_suspend_completion
642 // The assertion for that is currently too complex to put here:
643 bool JavaThread::profile_last_Java_frame(frame* _fr) {
644 bool gotframe = false;
645 // self suspension saves needed state.
646 if (has_last_Java_frame() && _anchor.walkable()) {
647 *_fr = pd_last_frame();
653 void Thread::interrupt(Thread* thread) {
654 trace("interrupt", thread);
655 debug_only(check_for_dangling_thread_pointer(thread);)
656 os::interrupt(thread);
659 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
660 trace("is_interrupted", thread);
661 debug_only(check_for_dangling_thread_pointer(thread);)
662 // Note: If clear_interrupted==false, this simply fetches and
663 // returns the value of the field osthread()->interrupted().
664 return os::is_interrupted(thread, clear_interrupted);
669 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
670 jint thread_parity = _oops_do_parity;
671 if (thread_parity != strong_roots_parity) {
672 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
673 if (res == thread_parity) return true;
675 guarantee(res == strong_roots_parity, "Or else what?");
676 assert(SharedHeap::heap()->n_par_threads() > 0,
677 "Should only fail when parallel.");
681 assert(SharedHeap::heap()->n_par_threads() > 0,
682 "Should only fail when parallel.");
686 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
687 active_handles()->oops_do(f);
688 // Do oop for ThreadShadow
689 f->do_oop((oop*)&_pending_exception);
690 handle_area()->oops_do(f);
693 void Thread::nmethods_do(CodeBlobClosure* cf) {
694 // no nmethods in a generic thread...
697 void Thread::print_on(outputStream* st) const {
698 // get_priority assumes osthread initialized
699 if (osthread() != NULL) {
700 st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this);
701 osthread()->print_on(st);
703 debug_only(if (WizardMode) print_owned_locks_on(st);)
706 // Thread::print_on_error() is called by fatal error handler. Don't use
707 // any lock or allocate memory.
708 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
709 if (is_VM_thread()) st->print("VMThread");
710 else if (is_Compiler_thread()) st->print("CompilerThread");
711 else if (is_Java_thread()) st->print("JavaThread");
712 else if (is_GC_task_thread()) st->print("GCTaskThread");
713 else if (is_Watcher_thread()) st->print("WatcherThread");
714 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
715 else st->print("Thread");
717 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
718 _stack_base - _stack_size, _stack_base);
721 st->print(" [id=%d]", osthread()->thread_id());
726 void Thread::print_owned_locks_on(outputStream* st) const {
727 Monitor *cur = _owned_locks;
729 st->print(" (no locks) ");
731 st->print_cr(" Locks owned:");
739 static int ref_use_count = 0;
741 bool Thread::owns_locks_but_compiled_lock() const {
742 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
743 if (cur != Compile_lock) return true;
753 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
754 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
755 // no threads which allow_vm_block's are held
756 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
757 // Check if current thread is allowed to block at a safepoint
758 if (!(_allow_safepoint_count == 0))
759 fatal("Possible safepoint reached by thread that does not allow it");
760 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
761 fatal("LEAF method calling lock?");
765 if (potential_vm_operation && is_Java_thread()
766 && !Universe::is_bootstrapping()) {
767 // Make sure we do not hold any locks that the VM thread also uses.
768 // This could potentially lead to deadlocks
769 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
770 // Threads_lock is special, since the safepoint synchronization will not start before this is
771 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
772 // since it is used to transfer control between JavaThreads and the VMThread
773 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
774 if ( (cur->allow_vm_block() &&
775 cur != Threads_lock &&
776 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
777 cur != VMOperationRequest_lock &&
778 cur != VMOperationQueue_lock) ||
779 cur->rank() == Mutex::special) {
780 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
785 if (GCALotAtAllSafepoints) {
786 // We could enter a safepoint here and thus have a gc
787 InterfaceSupport::check_gc_alot();
793 bool Thread::is_in_stack(address adr) const {
794 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
795 address end = os::current_stack_pointer();
796 if (stack_base() >= adr && adr >= end) return true;
802 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
803 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
804 // used for compilation in the future. If that change is made, the need for these methods
805 // should be revisited, and they should be removed if possible.
807 bool Thread::is_lock_owned(address adr) const {
808 return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
811 bool Thread::set_as_starting_thread() {
812 // NOTE: this must be called inside the main thread.
813 return os::create_main_thread((JavaThread*)this);
816 static void initialize_class(symbolHandle class_name, TRAPS) {
817 klassOop klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
818 instanceKlass::cast(klass)->initialize(CHECK);
822 // Creates the initial ThreadGroup
823 static Handle create_initial_thread_group(TRAPS) {
824 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH);
825 instanceKlassHandle klass (THREAD, k);
827 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
829 JavaValue result(T_VOID);
830 JavaCalls::call_special(&result,
833 vmSymbolHandles::object_initializer_name(),
834 vmSymbolHandles::void_method_signature(),
837 Universe::set_system_thread_group(system_instance());
839 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
841 JavaValue result(T_VOID);
842 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
843 JavaCalls::call_special(&result,
846 vmSymbolHandles::object_initializer_name(),
847 vmSymbolHandles::threadgroup_string_void_signature(),
852 return main_instance;
855 // Creates the initial Thread
856 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
857 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL);
858 instanceKlassHandle klass (THREAD, k);
859 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
861 java_lang_Thread::set_thread(thread_oop(), thread);
862 java_lang_Thread::set_priority(thread_oop(), NormPriority);
863 thread->set_threadObj(thread_oop());
865 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
867 JavaValue result(T_VOID);
868 JavaCalls::call_special(&result, thread_oop,
870 vmSymbolHandles::object_initializer_name(),
871 vmSymbolHandles::threadgroup_string_void_signature(),
878 static void call_initializeSystemClass(TRAPS) {
879 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
880 instanceKlassHandle klass (THREAD, k);
882 JavaValue result(T_VOID);
883 JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(),
884 vmSymbolHandles::void_method_signature(), CHECK);
887 static void reset_vm_info_property(TRAPS) {
888 // the vm info string
889 ResourceMark rm(THREAD);
890 const char *vm_info = VM_Version::vm_info_string();
892 // java.lang.System class
893 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
894 instanceKlassHandle klass (THREAD, k);
896 // setProperty arguments
897 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
898 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
901 JavaValue r(T_OBJECT);
903 // public static String setProperty(String key, String value);
904 JavaCalls::call_static(&r,
906 vmSymbolHandles::setProperty_name(),
907 vmSymbolHandles::string_string_string_signature(),
914 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
915 assert(thread_group.not_null(), "thread group should be specified");
916 assert(threadObj() == NULL, "should only create Java thread object once");
918 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
919 instanceKlassHandle klass (THREAD, k);
920 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
922 java_lang_Thread::set_thread(thread_oop(), this);
923 java_lang_Thread::set_priority(thread_oop(), NormPriority);
924 set_threadObj(thread_oop());
926 JavaValue result(T_VOID);
927 if (thread_name != NULL) {
928 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
929 // Thread gets assigned specified name and null target
930 JavaCalls::call_special(&result,
933 vmSymbolHandles::object_initializer_name(),
934 vmSymbolHandles::threadgroup_string_void_signature(),
935 thread_group, // Argument 1
939 // Thread gets assigned name "Thread-nnn" and null target
940 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
941 JavaCalls::call_special(&result,
944 vmSymbolHandles::object_initializer_name(),
945 vmSymbolHandles::threadgroup_runnable_void_signature(),
946 thread_group, // Argument 1
947 Handle(), // Argument 2
953 java_lang_Thread::set_daemon(thread_oop());
956 if (HAS_PENDING_EXCEPTION) {
960 KlassHandle group(this, SystemDictionary::threadGroup_klass());
961 Handle threadObj(this, this->threadObj());
963 JavaCalls::call_special(&result,
966 vmSymbolHandles::add_method_name(),
967 vmSymbolHandles::thread_void_signature(),
974 // NamedThread -- non-JavaThread subclasses with multiple
975 // uniquely named instances should derive from this.
976 NamedThread::NamedThread() : Thread() {
980 NamedThread::~NamedThread() {
982 FREE_C_HEAP_ARRAY(char, _name);
987 void NamedThread::set_name(const char* format, ...) {
988 guarantee(_name == NULL, "Only get to set name once.");
989 _name = NEW_C_HEAP_ARRAY(char, max_name_len);
990 guarantee(_name != NULL, "alloc failure");
992 va_start(ap, format);
993 jio_vsnprintf(_name, max_name_len, format, ap);
997 // ======= WatcherThread ========
999 // The watcher thread exists to simulate timer interrupts. It should
1000 // be replaced by an abstraction over whatever native support for
1001 // timer interrupts exists on the platform.
1003 WatcherThread* WatcherThread::_watcher_thread = NULL;
1004 bool WatcherThread::_should_terminate = false;
1006 WatcherThread::WatcherThread() : Thread() {
1007 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1008 if (os::create_thread(this, os::watcher_thread)) {
1009 _watcher_thread = this;
1011 // Set the watcher thread to the highest OS priority which should not be
1012 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1013 // is created. The only normal thread using this priority is the reference
1014 // handler thread, which runs for very short intervals only.
1015 // If the VMThread's priority is not lower than the WatcherThread profiling
1016 // will be inaccurate.
1017 os::set_priority(this, MaxPriority);
1018 if (!DisableStartThread) {
1019 os::start_thread(this);
1024 void WatcherThread::run() {
1025 assert(this == watcher_thread(), "just checking");
1027 this->record_stack_base_and_size();
1028 this->initialize_thread_local_storage();
1029 this->set_active_handles(JNIHandleBlock::allocate_block());
1030 while(!_should_terminate) {
1031 assert(watcher_thread() == Thread::current(), "thread consistency check");
1032 assert(watcher_thread() == this, "thread consistency check");
1034 // Calculate how long it'll be until the next PeriodicTask work
1035 // should be done, and sleep that amount of time.
1036 const size_t time_to_wait = PeriodicTask::time_to_wait();
1037 os::sleep(this, time_to_wait, false);
1039 if (is_error_reported()) {
1040 // A fatal error has happened, the error handler(VMError::report_and_die)
1041 // should abort JVM after creating an error log file. However in some
1042 // rare cases, the error handler itself might deadlock. Here we try to
1043 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1045 // This code is in WatcherThread because WatcherThread wakes up
1046 // periodically so the fatal error handler doesn't need to do anything;
1047 // also because the WatcherThread is less likely to crash than other
1051 if (!ShowMessageBoxOnError
1052 && (OnError == NULL || OnError[0] == '\0')
1053 && Arguments::abort_hook() == NULL) {
1054 os::sleep(this, 2 * 60 * 1000, false);
1055 fdStream err(defaultStream::output_fd());
1056 err.print_raw_cr("# [ timer expired, abort... ]");
1057 // skip atexit/vm_exit/vm_abort hooks
1061 // Wake up 5 seconds later, the fatal handler may reset OnError or
1062 // ShowMessageBoxOnError when it is ready to abort.
1063 os::sleep(this, 5 * 1000, false);
1067 PeriodicTask::real_time_tick(time_to_wait);
1069 // If we have no more tasks left due to dynamic disenrollment,
1070 // shut down the thread since we don't currently support dynamic enrollment
1071 if (PeriodicTask::num_tasks() == 0) {
1072 _should_terminate = true;
1076 // Signal that it is terminated
1078 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1079 _watcher_thread = NULL;
1080 Terminator_lock->notify();
1083 // Thread destructor usually does this..
1084 ThreadLocalStorage::set_thread(NULL);
1087 void WatcherThread::start() {
1088 if (watcher_thread() == NULL) {
1089 _should_terminate = false;
1090 // Create the single instance of WatcherThread
1091 new WatcherThread();
1095 void WatcherThread::stop() {
1096 // it is ok to take late safepoints here, if needed
1097 MutexLocker mu(Terminator_lock);
1098 _should_terminate = true;
1099 while(watcher_thread() != NULL) {
1100 // This wait should make safepoint checks, wait without a timeout,
1101 // and wait as a suspend-equivalent condition.
1103 // Note: If the FlatProfiler is running, then this thread is waiting
1104 // for the WatcherThread to terminate and the WatcherThread, via the
1105 // FlatProfiler task, is waiting for the external suspend request on
1106 // this thread to complete. wait_for_ext_suspend_completion() will
1107 // eventually timeout, but that takes time. Making this wait a
1108 // suspend-equivalent condition solves that timeout problem.
1110 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1111 Mutex::_as_suspend_equivalent_flag);
1115 void WatcherThread::print_on(outputStream* st) const {
1116 st->print("\"%s\" ", name());
1117 Thread::print_on(st);
1121 // ======= JavaThread ========
1123 // A JavaThread is a normal Java thread
1125 void JavaThread::initialize() {
1126 // Initialize fields
1128 // Set the claimed par_id to -1 (ie not claiming any par_ids)
1129 set_claimed_par_id(-1);
1131 set_saved_exception_pc(NULL);
1132 set_threadObj(NULL);
1134 set_entry_point(NULL);
1135 set_jni_functions(jni_functions());
1136 set_callee_target(NULL);
1137 set_vm_result(NULL);
1138 set_vm_result_2(NULL);
1139 set_vframe_array_head(NULL);
1140 set_vframe_array_last(NULL);
1141 set_deferred_locals(NULL);
1142 set_deopt_mark(NULL);
1143 clear_must_deopt_id();
1144 set_monitor_chunks(NULL);
1146 set_thread_state(_thread_new);
1147 _terminated = _not_terminated;
1148 _privileged_stack_top = NULL;
1149 _array_for_gc = NULL;
1150 _suspend_equivalent = false;
1151 _in_deopt_handler = 0;
1152 _doing_unsafe_access = false;
1153 _stack_guard_state = stack_guard_unused;
1154 _exception_oop = NULL;
1156 _exception_handler_pc = 0;
1157 _exception_stack_size = 0;
1158 _jvmti_thread_state= NULL;
1159 _jvmti_get_loaded_classes_closure = NULL;
1160 _interp_only_mode = 0;
1161 _special_runtime_exit_condition = _no_async_condition;
1162 _pending_async_exception = NULL;
1163 _is_compiling = false;
1164 _thread_stat = NULL;
1165 _thread_stat = new ThreadStatistics();
1166 _blocked_on_compilation = false;
1167 _jni_active_critical = 0;
1168 _do_not_unlock_if_synchronized = false;
1169 _cached_monitor_info = NULL;
1170 _parker = Parker::Allocate(this) ;
1173 _jmp_ring_index = 0;
1174 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1175 record_jump(NULL, NULL, NULL, 0);
1177 #endif /* PRODUCT */
1179 set_thread_profiler(NULL);
1180 if (FlatProfiler::is_active()) {
1181 // This is where we would decide to either give each thread it's own profiler
1182 // or use one global one from FlatProfiler,
1183 // or up to some count of the number of profiled threads, etc.
1184 ThreadProfiler* pp = new ThreadProfiler();
1186 set_thread_profiler(pp);
1189 // Setup safepoint state info for this thread
1190 ThreadSafepointState::create(this);
1192 debug_only(_java_call_counter = 0);
1194 // JVMTI PopFrame support
1195 _popframe_condition = popframe_inactive;
1196 _popframe_preserved_args = NULL;
1197 _popframe_preserved_args_size = 0;
1203 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1204 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1207 JavaThread::JavaThread(bool is_attaching) :
1210 , _satb_mark_queue(&_satb_mark_queue_set),
1211 _dirty_card_queue(&_dirty_card_queue_set)
1215 _is_attaching = is_attaching;
1216 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor");
1219 bool JavaThread::reguard_stack(address cur_sp) {
1220 if (_stack_guard_state != stack_guard_yellow_disabled) {
1221 return true; // Stack already guarded or guard pages not needed.
1224 if (register_stack_overflow()) {
1225 // For those architectures which have separate register and
1226 // memory stacks, we must check the register stack to see if
1227 // it has overflowed.
1231 // Java code never executes within the yellow zone: the latter is only
1232 // there to provoke an exception during stack banging. If java code
1233 // is executing there, either StackShadowPages should be larger, or
1234 // some exception code in c1, c2 or the interpreter isn't unwinding
1236 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1238 enable_stack_yellow_zone();
1242 bool JavaThread::reguard_stack(void) {
1243 return reguard_stack(os::current_stack_pointer());
1247 void JavaThread::block_if_vm_exited() {
1248 if (_terminated == _vm_exited) {
1249 // _vm_exited is set at safepoint, and Threads_lock is never released
1250 // we will block here forever
1251 Threads_lock->lock_without_safepoint_check();
1252 ShouldNotReachHere();
1257 // Remove this ifdef when C1 is ported to the compiler interface.
1258 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1260 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1263 , _satb_mark_queue(&_satb_mark_queue_set),
1264 _dirty_card_queue(&_dirty_card_queue_set)
1267 if (TraceThreadEvents) {
1268 tty->print_cr("creating thread %p", this);
1271 _is_attaching = false;
1272 set_entry_point(entry_point);
1273 // Create the native thread itself.
1275 os::ThreadType thr_type = os::java_thread;
1276 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1278 os::create_thread(this, thr_type, stack_sz);
1280 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1281 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1282 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1283 // the exception consists of creating the exception object & initializing it, initialization
1284 // will leave the VM via a JavaCall and then all locks must be unlocked).
1286 // The thread is still suspended when we reach here. Thread must be explicit started
1287 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1288 // by calling Threads:add. The reason why this is not done here, is because the thread
1289 // object must be fully initialized (take a look at JVM_Start)
1292 JavaThread::~JavaThread() {
1293 if (TraceThreadEvents) {
1294 tty->print_cr("terminate thread %p", this);
1297 // JSR166 -- return the parker to the free list
1298 Parker::Release(_parker);
1301 // Free any remaining previous UnrollBlock
1302 vframeArray* old_array = vframe_array_last();
1304 if (old_array != NULL) {
1305 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1306 old_array->set_unroll_block(NULL);
1311 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1312 if (deferred != NULL) {
1313 // This can only happen if thread is destroyed before deoptimization occurs.
1314 assert(deferred->length() != 0, "empty array!");
1316 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1317 deferred->remove_at(0);
1318 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1320 } while (deferred->length() != 0);
1324 // All Java related clean up happens in exit
1325 ThreadSafepointState::destroy(this);
1326 if (_thread_profiler != NULL) delete _thread_profiler;
1327 if (_thread_stat != NULL) delete _thread_stat;
1331 // The first routine called by a new Java thread
1332 void JavaThread::run() {
1333 // initialize thread-local alloc buffer related fields
1334 this->initialize_tlab();
1336 // used to test validitity of stack trace backs
1337 this->record_base_of_stack_pointer();
1339 // Record real stack base and size.
1340 this->record_stack_base_and_size();
1342 // Initialize thread local storage; set before calling MutexLocker
1343 this->initialize_thread_local_storage();
1345 this->create_stack_guard_pages();
1347 // Thread is now sufficient initialized to be handled by the safepoint code as being
1348 // in the VM. Change thread state from _thread_new to _thread_in_vm
1349 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1351 assert(JavaThread::current() == this, "sanity check");
1352 assert(!Thread::current()->owns_locks(), "sanity check");
1354 DTRACE_THREAD_PROBE(start, this);
1356 // This operation might block. We call that after all safepoint checks for a new thread has
1358 this->set_active_handles(JNIHandleBlock::allocate_block());
1360 if (JvmtiExport::should_post_thread_life()) {
1361 JvmtiExport::post_thread_start(this);
1364 // We call another function to do the rest so we are sure that the stack addresses used
1365 // from there will be lower than the stack base just computed
1366 thread_main_inner();
1368 // Note, thread is no longer valid at this point!
1372 void JavaThread::thread_main_inner() {
1373 assert(JavaThread::current() == this, "sanity check");
1374 assert(this->threadObj() != NULL, "just checking");
1376 // Execute thread entry point. If this thread is being asked to restart,
1377 // or has been stopped before starting, do not reexecute entry point.
1378 // Note: Due to JVM_StopThread we can have pending exceptions already!
1379 if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) {
1380 // enter the thread's entry point only if we have no pending exceptions
1381 HandleMark hm(this);
1382 this->entry_point()(this, this);
1385 DTRACE_THREAD_PROBE(stop, this);
1392 static void ensure_join(JavaThread* thread) {
1393 // We do not need to grap the Threads_lock, since we are operating on ourself.
1394 Handle threadObj(thread, thread->threadObj());
1395 assert(threadObj.not_null(), "java thread object must exist");
1396 ObjectLocker lock(threadObj, thread);
1397 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1398 thread->clear_pending_exception();
1399 // It is of profound importance that we set the stillborn bit and reset the thread object,
1400 // before we do the notify. Since, changing these two variable will make JVM_IsAlive return
1401 // false. So in case another thread is doing a join on this thread , it will detect that the thread
1402 // is dead when it gets notified.
1403 java_lang_Thread::set_stillborn(threadObj());
1404 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1405 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1406 java_lang_Thread::set_thread(threadObj(), NULL);
1407 lock.notify_all(thread);
1408 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1409 thread->clear_pending_exception();
1413 // For any new cleanup additions, please check to see if they need to be applied to
1414 // cleanup_failed_attach_current_thread as well.
1415 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1416 assert(this == JavaThread::current(), "thread consistency check");
1417 if (!InitializeJavaLangSystem) return;
1419 HandleMark hm(this);
1420 Handle uncaught_exception(this, this->pending_exception());
1421 this->clear_pending_exception();
1422 Handle threadObj(this, this->threadObj());
1423 assert(threadObj.not_null(), "Java thread object should be created");
1425 if (get_thread_profiler() != NULL) {
1426 get_thread_profiler()->disengage();
1428 get_thread_profiler()->print(get_thread_name());
1432 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1436 CLEAR_PENDING_EXCEPTION;
1438 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1439 // has to be fixed by a runtime query method
1440 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1441 // JSR-166: change call from from ThreadGroup.uncaughtException to
1442 // java.lang.Thread.dispatchUncaughtException
1443 if (uncaught_exception.not_null()) {
1444 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1445 Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT",
1446 (address)uncaught_exception(), (address)threadObj(), (address)group());
1449 // Check if the method Thread.dispatchUncaughtException() exists. If so
1450 // call it. Otherwise we have an older library without the JSR-166 changes,
1451 // so call ThreadGroup.uncaughtException()
1452 KlassHandle recvrKlass(THREAD, threadObj->klass());
1454 KlassHandle thread_klass(THREAD, SystemDictionary::thread_klass());
1455 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1456 vmSymbolHandles::dispatchUncaughtException_name(),
1457 vmSymbolHandles::throwable_void_signature(),
1458 KlassHandle(), false, false, THREAD);
1459 CLEAR_PENDING_EXCEPTION;
1460 methodHandle method = callinfo.selected_method();
1461 if (method.not_null()) {
1462 JavaValue result(T_VOID);
1463 JavaCalls::call_virtual(&result,
1464 threadObj, thread_klass,
1465 vmSymbolHandles::dispatchUncaughtException_name(),
1466 vmSymbolHandles::throwable_void_signature(),
1470 KlassHandle thread_group(THREAD, SystemDictionary::threadGroup_klass());
1471 JavaValue result(T_VOID);
1472 JavaCalls::call_virtual(&result,
1473 group, thread_group,
1474 vmSymbolHandles::uncaughtException_name(),
1475 vmSymbolHandles::thread_throwable_void_signature(),
1477 uncaught_exception, // Arg 2
1480 CLEAR_PENDING_EXCEPTION;
1484 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1485 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1486 // is deprecated anyhow.
1488 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1490 JavaValue result(T_VOID);
1491 KlassHandle thread_klass(THREAD, SystemDictionary::thread_klass());
1492 JavaCalls::call_virtual(&result,
1493 threadObj, thread_klass,
1494 vmSymbolHandles::exit_method_name(),
1495 vmSymbolHandles::void_method_signature(),
1497 CLEAR_PENDING_EXCEPTION;
1502 if (JvmtiExport::should_post_thread_life()) {
1503 JvmtiExport::post_thread_end(this);
1506 // We have notified the agents that we are exiting, before we go on,
1507 // we must check for a pending external suspend request and honor it
1508 // in order to not surprise the thread that made the suspend request.
1511 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1512 if (!is_external_suspend()) {
1513 set_terminated(_thread_exiting);
1514 ThreadService::current_thread_exiting(this);
1518 // Things get a little tricky here. We have a pending external
1519 // suspend request, but we are holding the SR_lock so we
1520 // can't just self-suspend. So we temporarily drop the lock
1521 // and then self-suspend.
1524 ThreadBlockInVM tbivm(this);
1525 java_suspend_self();
1527 // We're done with this suspend request, but we have to loop around
1528 // and check again. Eventually we will get SR_lock without a pending
1529 // external suspend request and will be able to mark ourselves as
1532 // no more external suspends are allowed at this point
1534 // before_exit() has already posted JVMTI THREAD_END events
1537 // Notify waiters on thread object. This has to be done after exit() is called
1538 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1539 // group should have the destroyed bit set before waiters are notified).
1541 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1543 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1544 // held by this thread must be released. A detach operation must only
1545 // get here if there are no Java frames on the stack. Therefore, any
1546 // owned monitors at this point MUST be JNI-acquired monitors which are
1547 // pre-inflated and in the monitor cache.
1549 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1550 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1551 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1552 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1553 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1556 // These things needs to be done while we are still a Java Thread. Make sure that thread
1557 // is in a consistent state, in case GC happens
1558 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1560 if (active_handles() != NULL) {
1561 JNIHandleBlock* block = active_handles();
1562 set_active_handles(NULL);
1563 JNIHandleBlock::release_block(block);
1566 if (free_handle_block() != NULL) {
1567 JNIHandleBlock* block = free_handle_block();
1568 set_free_handle_block(NULL);
1569 JNIHandleBlock::release_block(block);
1572 // These have to be removed while this is still a valid thread.
1573 remove_stack_guard_pages();
1576 tlab().make_parsable(true); // retire TLAB
1579 if (jvmti_thread_state() != NULL) {
1580 JvmtiExport::cleanup_thread(this);
1584 // We must flush G1-related buffers before removing a thread from
1585 // the list of active threads.
1587 flush_barrier_queues();
1591 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1592 Threads::remove(this);
1596 // Flush G1-related queues.
1597 void JavaThread::flush_barrier_queues() {
1598 satb_mark_queue().flush();
1599 dirty_card_queue().flush();
1603 void JavaThread::cleanup_failed_attach_current_thread() {
1604 if (get_thread_profiler() != NULL) {
1605 get_thread_profiler()->disengage();
1607 get_thread_profiler()->print(get_thread_name());
1610 if (active_handles() != NULL) {
1611 JNIHandleBlock* block = active_handles();
1612 set_active_handles(NULL);
1613 JNIHandleBlock::release_block(block);
1616 if (free_handle_block() != NULL) {
1617 JNIHandleBlock* block = free_handle_block();
1618 set_free_handle_block(NULL);
1619 JNIHandleBlock::release_block(block);
1623 tlab().make_parsable(true); // retire TLAB, if any
1628 flush_barrier_queues();
1632 Threads::remove(this);
1639 JavaThread* JavaThread::active() {
1640 Thread* thread = ThreadLocalStorage::thread();
1641 assert(thread != NULL, "just checking");
1642 if (thread->is_Java_thread()) {
1643 return (JavaThread*) thread;
1645 assert(thread->is_VM_thread(), "this must be a vm thread");
1646 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1647 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1648 assert(ret->is_Java_thread(), "must be a Java thread");
1653 bool JavaThread::is_lock_owned(address adr) const {
1654 if (Thread::is_lock_owned(adr)) return true;
1656 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1657 if (chunk->contains(adr)) return true;
1664 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1665 chunk->set_next(monitor_chunks());
1666 set_monitor_chunks(chunk);
1669 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1670 guarantee(monitor_chunks() != NULL, "must be non empty");
1671 if (monitor_chunks() == chunk) {
1672 set_monitor_chunks(chunk->next());
1674 MonitorChunk* prev = monitor_chunks();
1675 while (prev->next() != chunk) prev = prev->next();
1676 prev->set_next(chunk->next());
1682 // Note: this function shouldn't block if it's called in
1683 // _thread_in_native_trans state (such as from
1684 // check_special_condition_for_native_trans()).
1685 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
1687 if (has_last_Java_frame() && has_async_condition()) {
1688 // If we are at a polling page safepoint (not a poll return)
1689 // then we must defer async exception because live registers
1690 // will be clobbered by the exception path. Poll return is
1691 // ok because the call we a returning from already collides
1692 // with exception handling registers and so there is no issue.
1693 // (The exception handling path kills call result registers but
1694 // this is ok since the exception kills the result anyway).
1696 if (is_at_poll_safepoint()) {
1697 // if the code we are returning to has deoptimized we must defer
1698 // the exception otherwise live registers get clobbered on the
1699 // exception path before deoptimization is able to retrieve them.
1701 RegisterMap map(this, false);
1702 frame caller_fr = last_frame().sender(&map);
1703 assert(caller_fr.is_compiled_frame(), "what?");
1704 if (caller_fr.is_deoptimized_frame()) {
1705 if (TraceExceptions) {
1707 tty->print_cr("deferred async exception at compiled safepoint");
1714 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
1715 if (condition == _no_async_condition) {
1716 // Conditions have changed since has_special_runtime_exit_condition()
1718 // - if we were here only because of an external suspend request,
1719 // then that was taken care of above (or cancelled) so we are done
1720 // - if we were here because of another async request, then it has
1721 // been cleared between the has_special_runtime_exit_condition()
1722 // and now so again we are done
1726 // Check for pending async. exception
1727 if (_pending_async_exception != NULL) {
1728 // Only overwrite an already pending exception, if it is not a threadDeath.
1729 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::threaddeath_klass())) {
1731 // We cannot call Exceptions::_throw(...) here because we cannot block
1732 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1734 if (TraceExceptions) {
1736 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
1737 if (has_last_Java_frame() ) {
1738 frame f = last_frame();
1739 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
1741 tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1743 _pending_async_exception = NULL;
1744 clear_has_async_exception();
1748 if (check_unsafe_error &&
1749 condition == _async_unsafe_access_error && !has_pending_exception()) {
1750 condition = _no_async_condition; // done
1751 switch (thread_state()) {
1754 JavaThread* THREAD = this;
1755 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1757 case _thread_in_native:
1759 ThreadInVMfromNative tiv(this);
1760 JavaThread* THREAD = this;
1761 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1763 case _thread_in_Java:
1765 ThreadInVMfromJava tiv(this);
1766 JavaThread* THREAD = this;
1767 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1770 ShouldNotReachHere();
1774 assert(condition == _no_async_condition || has_pending_exception() ||
1775 (!check_unsafe_error && condition == _async_unsafe_access_error),
1776 "must have handled the async condition, if no exception");
1779 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1781 // Check for pending external suspend. Internal suspend requests do
1782 // not use handle_special_runtime_exit_condition().
1783 // If JNIEnv proxies are allowed, don't self-suspend if the target
1784 // thread is not the current thread. In older versions of jdbx, jdbx
1785 // threads could call into the VM with another thread's JNIEnv so we
1786 // can be here operating on behalf of a suspended thread (4432884).
1787 bool do_self_suspend = is_external_suspend_with_lock();
1788 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
1790 // Because thread is external suspended the safepoint code will count
1791 // thread as at a safepoint. This can be odd because we can be here
1792 // as _thread_in_Java which would normally transition to _thread_blocked
1793 // at a safepoint. We would like to mark the thread as _thread_blocked
1794 // before calling java_suspend_self like all other callers of it but
1795 // we must then observe proper safepoint protocol. (We can't leave
1796 // _thread_blocked with a safepoint in progress). However we can be
1797 // here as _thread_in_native_trans so we can't use a normal transition
1798 // constructor/destructor pair because they assert on that type of
1799 // transition. We could do something like:
1801 // JavaThreadState state = thread_state();
1802 // set_thread_state(_thread_in_vm);
1804 // ThreadBlockInVM tbivm(this);
1805 // java_suspend_self()
1807 // set_thread_state(_thread_in_vm_trans);
1808 // if (safepoint) block;
1809 // set_thread_state(state);
1811 // but that is pretty messy. Instead we just go with the way the
1812 // code has worked before and note that this is the only path to
1813 // java_suspend_self that doesn't put the thread in _thread_blocked
1816 frame_anchor()->make_walkable(this);
1817 java_suspend_self();
1819 // We might be here for reasons in addition to the self-suspend request
1820 // so check for other async requests.
1824 check_and_handle_async_exceptions();
1828 void JavaThread::send_thread_stop(oop java_throwable) {
1829 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
1830 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
1831 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1833 // Do not throw asynchronous exceptions against the compiler thread
1834 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1835 if (is_Compiler_thread()) return;
1837 // This is a change from JDK 1.1, but JDK 1.2 will also do it:
1838 if (java_throwable->is_a(SystemDictionary::threaddeath_klass())) {
1839 java_lang_Thread::set_stillborn(threadObj());
1843 // Actually throw the Throwable against the target Thread - however
1844 // only if there is no thread death exception installed already.
1845 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::threaddeath_klass())) {
1846 // If the topmost frame is a runtime stub, then we are calling into
1847 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1848 // must deoptimize the caller before continuing, as the compiled exception handler table
1850 if (has_last_Java_frame()) {
1851 frame f = last_frame();
1852 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1853 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
1854 RegisterMap reg_map(this, UseBiasedLocking);
1855 frame compiled_frame = f.sender(®_map);
1856 if (compiled_frame.can_be_deoptimized()) {
1857 Deoptimization::deoptimize(this, compiled_frame, ®_map);
1862 // Set async. pending exception in thread.
1863 set_pending_async_exception(java_throwable);
1865 if (TraceExceptions) {
1867 tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1869 // for AbortVMOnException flag
1870 NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name()));
1875 // Interrupt thread so it will wake up from a potential wait()
1876 Thread::interrupt(this);
1879 // External suspension mechanism.
1881 // Tell the VM to suspend a thread when ever it knows that it does not hold on
1882 // to any VM_locks and it is at a transition
1883 // Self-suspension will happen on the transition out of the vm.
1884 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
1886 // Guarantees on return:
1887 // + Target thread will not execute any new bytecode (that's why we need to
1888 // force a safepoint)
1889 // + Target thread will not enter any new monitors
1891 void JavaThread::java_suspend() {
1892 { MutexLocker mu(Threads_lock);
1893 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
1898 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1899 if (!is_external_suspend()) {
1900 // a racing resume has cancelled us; bail out now
1905 uint32_t debug_bits = 0;
1906 // Warning: is_ext_suspend_completed() may temporarily drop the
1907 // SR_lock to allow the thread to reach a stable thread state if
1908 // it is currently in a transient thread state.
1909 if (is_ext_suspend_completed(false /* !called_by_wait */,
1910 SuspendRetryDelay, &debug_bits) ) {
1915 VM_ForceSafepoint vm_suspend;
1916 VMThread::execute(&vm_suspend);
1919 // Part II of external suspension.
1920 // A JavaThread self suspends when it detects a pending external suspend
1921 // request. This is usually on transitions. It is also done in places
1922 // where continuing to the next transition would surprise the caller,
1923 // e.g., monitor entry.
1925 // Returns the number of times that the thread self-suspended.
1927 // Note: DO NOT call java_suspend_self() when you just want to block current
1928 // thread. java_suspend_self() is the second stage of cooperative
1929 // suspension for external suspend requests and should only be used
1930 // to complete an external suspend request.
1932 int JavaThread::java_suspend_self() {
1935 // we are in the process of exiting so don't suspend
1937 clear_external_suspend();
1941 assert(_anchor.walkable() ||
1942 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
1943 "must have walkable stack");
1945 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1947 assert(!this->is_ext_suspended(),
1948 "a thread trying to self-suspend should not already be suspended");
1950 if (this->is_suspend_equivalent()) {
1951 // If we are self-suspending as a result of the lifting of a
1952 // suspend equivalent condition, then the suspend_equivalent
1953 // flag is not cleared until we set the ext_suspended flag so
1954 // that wait_for_ext_suspend_completion() returns consistent
1956 this->clear_suspend_equivalent();
1959 // A racing resume may have cancelled us before we grabbed SR_lock
1960 // above. Or another external suspend request could be waiting for us
1961 // by the time we return from SR_lock()->wait(). The thread
1962 // that requested the suspension may already be trying to walk our
1963 // stack and if we return now, we can change the stack out from under
1964 // it. This would be a "bad thing (TM)" and cause the stack walker
1965 // to crash. We stay self-suspended until there are no more pending
1966 // external suspend requests.
1967 while (is_external_suspend()) {
1969 this->set_ext_suspended();
1971 // _ext_suspended flag is cleared by java_resume()
1972 while (is_ext_suspended()) {
1973 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
1981 // verify the JavaThread has not yet been published in the Threads::list, and
1982 // hence doesn't need protection from concurrent access at this stage
1983 void JavaThread::verify_not_published() {
1984 if (!Threads_lock->owned_by_self()) {
1985 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
1986 assert( !Threads::includes(this),
1987 "java thread shouldn't have been published yet!");
1990 assert( !Threads::includes(this),
1991 "java thread shouldn't have been published yet!");
1996 // Slow path when the native==>VM/Java barriers detect a safepoint is in
1997 // progress or when _suspend_flags is non-zero.
1998 // Current thread needs to self-suspend if there is a suspend request and/or
1999 // block if a safepoint is in progress.
2000 // Async exception ISN'T checked.
2001 // Note only the ThreadInVMfromNative transition can call this function
2002 // directly and when thread state is _thread_in_native_trans
2003 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2004 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2006 JavaThread *curJT = JavaThread::current();
2007 bool do_self_suspend = thread->is_external_suspend();
2009 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2011 // If JNIEnv proxies are allowed, don't self-suspend if the target
2012 // thread is not the current thread. In older versions of jdbx, jdbx
2013 // threads could call into the VM with another thread's JNIEnv so we
2014 // can be here operating on behalf of a suspended thread (4432884).
2015 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2016 JavaThreadState state = thread->thread_state();
2018 // We mark this thread_blocked state as a suspend-equivalent so
2019 // that a caller to is_ext_suspend_completed() won't be confused.
2020 // The suspend-equivalent state is cleared by java_suspend_self().
2021 thread->set_suspend_equivalent();
2023 // If the safepoint code sees the _thread_in_native_trans state, it will
2024 // wait until the thread changes to other thread state. There is no
2025 // guarantee on how soon we can obtain the SR_lock and complete the
2026 // self-suspend request. It would be a bad idea to let safepoint wait for
2027 // too long. Temporarily change the state to _thread_blocked to
2028 // let the VM thread know that this thread is ready for GC. The problem
2029 // of changing thread state is that safepoint could happen just after
2030 // java_suspend_self() returns after being resumed, and VM thread will
2031 // see the _thread_blocked state. We must check for safepoint
2032 // after restoring the state and make sure we won't leave while a safepoint
2034 thread->set_thread_state(_thread_blocked);
2035 thread->java_suspend_self();
2036 thread->set_thread_state(state);
2037 // Make sure new state is seen by VM thread
2040 // Force a fence between the write above and read below
2041 OrderAccess::fence();
2043 // Must use this rather than serialization page in particular on Windows
2044 InterfaceSupport::serialize_memory(thread);
2049 if (SafepointSynchronize::do_call_back()) {
2050 // If we are safepointing, then block the caller which may not be
2051 // the same as the target thread (see above).
2052 SafepointSynchronize::block(curJT);
2055 if (thread->is_deopt_suspend()) {
2056 thread->clear_deopt_suspend();
2057 RegisterMap map(thread, false);
2058 frame f = thread->last_frame();
2059 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2062 if (f.id() == thread->must_deopt_id()) {
2063 thread->clear_must_deopt_id();
2064 // Since we know we're safe to deopt the current state is a safe state
2065 f.deoptimize(thread, true);
2067 fatal("missed deoptimization!");
2072 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2073 // progress or when _suspend_flags is non-zero.
2074 // Current thread needs to self-suspend if there is a suspend request and/or
2075 // block if a safepoint is in progress.
2076 // Also check for pending async exception (not including unsafe access error).
2077 // Note only the native==>VM/Java barriers can call this function and when
2078 // thread state is _thread_in_native_trans.
2079 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2080 check_safepoint_and_suspend_for_native_trans(thread);
2082 if (thread->has_async_exception()) {
2083 // We are in _thread_in_native_trans state, don't handle unsafe
2084 // access error since that may block.
2085 thread->check_and_handle_async_exceptions(false);
2089 // We need to guarantee the Threads_lock here, since resumes are not
2090 // allowed during safepoint synchronization
2091 // Can only resume from an external suspension
2092 void JavaThread::java_resume() {
2093 assert_locked_or_safepoint(Threads_lock);
2095 // Sanity check: thread is gone, has started exiting or the thread
2096 // was not externally suspended.
2097 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2101 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2103 clear_external_suspend();
2105 if (is_ext_suspended()) {
2106 clear_ext_suspended();
2107 SR_lock()->notify_all();
2111 void JavaThread::create_stack_guard_pages() {
2112 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2113 address low_addr = stack_base() - stack_size();
2114 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2116 int allocate = os::allocate_stack_guard_pages();
2117 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2119 if (allocate && !os::commit_memory((char *) low_addr, len)) {
2120 warning("Attempt to allocate stack guard pages failed.");
2124 if (os::guard_memory((char *) low_addr, len)) {
2125 _stack_guard_state = stack_guard_enabled;
2127 warning("Attempt to protect stack guard pages failed.");
2128 if (os::uncommit_memory((char *) low_addr, len)) {
2129 warning("Attempt to deallocate stack guard pages failed.");
2134 void JavaThread::remove_stack_guard_pages() {
2135 if (_stack_guard_state == stack_guard_unused) return;
2136 address low_addr = stack_base() - stack_size();
2137 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2139 if (os::allocate_stack_guard_pages()) {
2140 if (os::uncommit_memory((char *) low_addr, len)) {
2141 _stack_guard_state = stack_guard_unused;
2143 warning("Attempt to deallocate stack guard pages failed.");
2146 if (_stack_guard_state == stack_guard_unused) return;
2147 if (os::unguard_memory((char *) low_addr, len)) {
2148 _stack_guard_state = stack_guard_unused;
2150 warning("Attempt to unprotect stack guard pages failed.");
2155 void JavaThread::enable_stack_yellow_zone() {
2156 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2157 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2159 // The base notation is from the stacks point of view, growing downward.
2160 // We need to adjust it to work correctly with guard_memory()
2161 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2163 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2164 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2166 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2167 _stack_guard_state = stack_guard_enabled;
2169 warning("Attempt to guard stack yellow zone failed.");
2171 enable_register_stack_guard();
2174 void JavaThread::disable_stack_yellow_zone() {
2175 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2176 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2178 // Simply return if called for a thread that does not use guard pages.
2179 if (_stack_guard_state == stack_guard_unused) return;
2181 // The base notation is from the stacks point of view, growing downward.
2182 // We need to adjust it to work correctly with guard_memory()
2183 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2185 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2186 _stack_guard_state = stack_guard_yellow_disabled;
2188 warning("Attempt to unguard stack yellow zone failed.");
2190 disable_register_stack_guard();
2193 void JavaThread::enable_stack_red_zone() {
2194 // The base notation is from the stacks point of view, growing downward.
2195 // We need to adjust it to work correctly with guard_memory()
2196 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2197 address base = stack_red_zone_base() - stack_red_zone_size();
2199 guarantee(base < stack_base(),"Error calculating stack red zone");
2200 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2202 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2203 warning("Attempt to guard stack red zone failed.");
2207 void JavaThread::disable_stack_red_zone() {
2208 // The base notation is from the stacks point of view, growing downward.
2209 // We need to adjust it to work correctly with guard_memory()
2210 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2211 address base = stack_red_zone_base() - stack_red_zone_size();
2212 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2213 warning("Attempt to unguard stack red zone failed.");
2217 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2218 // ignore is there is no stack
2219 if (!has_last_Java_frame()) return;
2220 // traverse the stack frames. Starts from top frame.
2221 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2222 frame* fr = fst.current();
2223 f(fr, fst.register_map());
2230 // Function for testing deoptimization
2231 void JavaThread::deoptimize() {
2232 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2233 StackFrameStream fst(this, UseBiasedLocking);
2234 bool deopt = false; // Dump stack only if a deopt actually happens.
2235 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2236 // Iterate over all frames in the thread and deoptimize
2237 for(; !fst.is_done(); fst.next()) {
2238 if(fst.current()->can_be_deoptimized()) {
2241 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2242 // consists of comma or carriage return separated numbers so
2243 // search for the current bci in that string.
2244 address pc = fst.current()->pc();
2245 nmethod* nm = (nmethod*) fst.current()->cb();
2246 ScopeDesc* sd = nm->scope_desc_at( pc);
2248 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2249 size_t len = strlen(buffer);
2250 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2251 while (found != NULL) {
2252 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2253 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2254 // Check that the bci found is bracketed by terminators.
2257 found = strstr(found + 1, buffer);
2264 if (DebugDeoptimization && !deopt) {
2265 deopt = true; // One-time only print before deopt
2266 tty->print_cr("[BEFORE Deoptimization]");
2270 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2274 if (DebugDeoptimization && deopt) {
2275 tty->print_cr("[AFTER Deoptimization]");
2282 void JavaThread::make_zombies() {
2283 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2284 if (fst.current()->can_be_deoptimized()) {
2285 // it is a Java nmethod
2286 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2287 nm->make_not_entrant();
2294 void JavaThread::deoptimized_wrt_marked_nmethods() {
2295 if (!has_last_Java_frame()) return;
2296 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2297 StackFrameStream fst(this, UseBiasedLocking);
2298 for(; !fst.is_done(); fst.next()) {
2299 if (fst.current()->should_be_deoptimized()) {
2300 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2307 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2309 void JavaThread::gc_epilogue() {
2310 frames_do(frame_gc_epilogue);
2314 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2316 void JavaThread::gc_prologue() {
2317 frames_do(frame_gc_prologue);
2321 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2322 // Flush deferred store-barriers, if any, associated with
2323 // initializing stores done by this JavaThread in the current epoch.
2324 Universe::heap()->flush_deferred_store_barrier(this);
2326 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2327 // since there may be more than one thread using each ThreadProfiler.
2329 // Traverse the GCHandles
2330 Thread::oops_do(f, cf);
2332 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2333 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2335 if (has_last_Java_frame()) {
2337 // Traverse the privileged stack
2338 if (_privileged_stack_top != NULL) {
2339 _privileged_stack_top->oops_do(f);
2342 // traverse the registered growable array
2343 if (_array_for_gc != NULL) {
2344 for (int index = 0; index < _array_for_gc->length(); index++) {
2345 f->do_oop(_array_for_gc->adr_at(index));
2349 // Traverse the monitor chunks
2350 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2354 // Traverse the execution stack
2355 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2356 fst.current()->oops_do(f, cf, fst.register_map());
2360 // callee_target is never live across a gc point so NULL it here should
2361 // it still contain a methdOop.
2363 set_callee_target(NULL);
2365 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2366 // If we have deferred set_locals there might be oops waiting to be
2368 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2370 for (int i = 0; i < list->length(); i++) {
2371 list->at(i)->oops_do(f);
2375 // Traverse instance variables at the end since the GC may be moving things
2376 // around using this function
2377 f->do_oop((oop*) &_threadObj);
2378 f->do_oop((oop*) &_vm_result);
2379 f->do_oop((oop*) &_vm_result_2);
2380 f->do_oop((oop*) &_exception_oop);
2381 f->do_oop((oop*) &_pending_async_exception);
2383 if (jvmti_thread_state() != NULL) {
2384 jvmti_thread_state()->oops_do(f);
2388 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2389 Thread::nmethods_do(cf); // (super method is a no-op)
2391 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2392 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2394 if (has_last_Java_frame()) {
2395 // Traverse the execution stack
2396 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2397 fst.current()->nmethods_do(cf);
2403 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2404 switch (_thread_state) {
2405 case _thread_uninitialized: return "_thread_uninitialized";
2406 case _thread_new: return "_thread_new";
2407 case _thread_new_trans: return "_thread_new_trans";
2408 case _thread_in_native: return "_thread_in_native";
2409 case _thread_in_native_trans: return "_thread_in_native_trans";
2410 case _thread_in_vm: return "_thread_in_vm";
2411 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2412 case _thread_in_Java: return "_thread_in_Java";
2413 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2414 case _thread_blocked: return "_thread_blocked";
2415 case _thread_blocked_trans: return "_thread_blocked_trans";
2416 default: return "unknown thread state";
2421 void JavaThread::print_thread_state_on(outputStream *st) const {
2422 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2424 void JavaThread::print_thread_state() const {
2425 print_thread_state_on(tty);
2429 // Called by Threads::print() for VM_PrintThreads operation
2430 void JavaThread::print_on(outputStream *st) const {
2431 st->print("\"%s\" ", get_thread_name());
2432 oop thread_oop = threadObj();
2433 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2434 Thread::print_on(st);
2435 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2436 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2437 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2438 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2441 print_thread_state_on(st);
2442 _safepoint_state->print_on(st);
2446 // Called by fatal error handler. The difference between this and
2447 // JavaThread::print() is that we can't grab lock or allocate memory.
2448 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2449 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2450 oop thread_obj = threadObj();
2451 if (thread_obj != NULL) {
2452 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2455 st->print("%s", _get_thread_state_name(_thread_state));
2457 st->print(", id=%d", osthread()->thread_id());
2459 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2460 _stack_base - _stack_size, _stack_base);
2467 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2469 void JavaThread::verify() {
2470 // Verify oops in the thread.
2471 oops_do(&VerifyOopClosure::verify_oop, NULL);
2473 // Verify the stack frames.
2474 frames_do(frame_verify);
2477 // CR 6300358 (sub-CR 2137150)
2478 // Most callers of this method assume that it can't return NULL but a
2479 // thread may not have a name whilst it is in the process of attaching to
2480 // the VM - see CR 6412693, and there are places where a JavaThread can be
2481 // seen prior to having it's threadObj set (eg JNI attaching threads and
2482 // if vm exit occurs during initialization). These cases can all be accounted
2483 // for such that this method never returns NULL.
2484 const char* JavaThread::get_thread_name() const {
2486 // early safepoints can hit while current thread does not yet have TLS
2487 if (!SafepointSynchronize::is_at_safepoint()) {
2488 Thread *cur = Thread::current();
2489 if (!(cur->is_Java_thread() && cur == this)) {
2490 // Current JavaThreads are allowed to get their own name without
2491 // the Threads_lock.
2492 assert_locked_or_safepoint(Threads_lock);
2496 return get_thread_name_string();
2499 // Returns a non-NULL representation of this thread's name, or a suitable
2500 // descriptive string if there is no set name
2501 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2502 const char* name_str;
2503 oop thread_obj = threadObj();
2504 if (thread_obj != NULL) {
2505 typeArrayOop name = java_lang_Thread::name(thread_obj);
2508 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2511 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2514 else if (is_attaching()) { // workaround for 6412693 - see 6404306
2515 name_str = "<no-name - thread is attaching>";
2518 name_str = Thread::name();
2522 name_str = Thread::name();
2524 assert(name_str != NULL, "unexpected NULL thread name");
2529 const char* JavaThread::get_threadgroup_name() const {
2530 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2531 oop thread_obj = threadObj();
2532 if (thread_obj != NULL) {
2533 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2534 if (thread_group != NULL) {
2535 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2536 // ThreadGroup.name can be null
2538 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2546 const char* JavaThread::get_parent_name() const {
2547 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2548 oop thread_obj = threadObj();
2549 if (thread_obj != NULL) {
2550 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2551 if (thread_group != NULL) {
2552 oop parent = java_lang_ThreadGroup::parent(thread_group);
2553 if (parent != NULL) {
2554 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2555 // ThreadGroup.name can be null
2557 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2566 ThreadPriority JavaThread::java_priority() const {
2567 oop thr_oop = threadObj();
2568 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2569 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2570 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2574 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2576 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2577 // Link Java Thread object <-> C++ Thread
2579 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2580 // and put it into a new Handle. The Handle "thread_oop" can then
2581 // be used to pass the C++ thread object to other methods.
2583 // Set the Java level thread object (jthread) field of the
2584 // new thread (a JavaThread *) to C++ thread object using the
2585 // "thread_oop" handle.
2587 // Set the thread field (a JavaThread *) of the
2588 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2590 Handle thread_oop(Thread::current(),
2591 JNIHandles::resolve_non_null(jni_thread));
2592 assert(instanceKlass::cast(thread_oop->klass())->is_linked(),
2593 "must be initialized");
2594 set_threadObj(thread_oop());
2595 java_lang_Thread::set_thread(thread_oop(), this);
2597 if (prio == NoPriority) {
2598 prio = java_lang_Thread::priority(thread_oop());
2599 assert(prio != NoPriority, "A valid priority should be present");
2602 // Push the Java priority down to the native thread; needs Threads_lock
2603 Thread::set_priority(this, prio);
2605 // Add the new thread to the Threads list and set it in motion.
2606 // We must have threads lock in order to call Threads::add.
2607 // It is crucial that we do not block before the thread is
2608 // added to the Threads list for if a GC happens, then the java_thread oop
2609 // will not be visited by GC.
2613 oop JavaThread::current_park_blocker() {
2614 // Support for JSR-166 locks
2615 oop thread_oop = threadObj();
2616 if (thread_oop != NULL &&
2617 JDK_Version::current().supports_thread_park_blocker()) {
2618 return java_lang_Thread::park_blocker(thread_oop);
2624 void JavaThread::print_stack_on(outputStream* st) {
2625 if (!has_last_Java_frame()) return;
2629 RegisterMap reg_map(this);
2630 vframe* start_vf = last_java_vframe(®_map);
2632 for (vframe* f = start_vf; f; f = f->sender() ) {
2633 if (f->is_java_frame()) {
2634 javaVFrame* jvf = javaVFrame::cast(f);
2635 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2637 // Print out lock information
2638 if (JavaMonitorsInStackTrace) {
2639 jvf->print_lock_info_on(st, count);
2642 // Ignore non-Java frames
2645 // Bail-out case for too deep stacks
2647 if (MaxJavaStackTraceDepth == count) return;
2652 // JVMTI PopFrame support
2653 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2654 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2655 if (in_bytes(size_in_bytes) != 0) {
2656 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes));
2657 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2658 Copy::conjoint_bytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2662 void* JavaThread::popframe_preserved_args() {
2663 return _popframe_preserved_args;
2666 ByteSize JavaThread::popframe_preserved_args_size() {
2667 return in_ByteSize(_popframe_preserved_args_size);
2670 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2671 int sz = in_bytes(popframe_preserved_args_size());
2672 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2673 return in_WordSize(sz / wordSize);
2676 void JavaThread::popframe_free_preserved_args() {
2677 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2678 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args);
2679 _popframe_preserved_args = NULL;
2680 _popframe_preserved_args_size = 0;
2685 void JavaThread::trace_frames() {
2686 tty->print_cr("[Describe stack]");
2688 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2689 tty->print(" %d. ", frame_no++);
2690 fst.current()->print_value_on(tty,this);
2696 void JavaThread::trace_stack_from(vframe* start_vf) {
2699 for (vframe* f = start_vf; f; f = f->sender() ) {
2700 if (f->is_java_frame()) {
2701 javaVFrame::cast(f)->print_activation(vframe_no++);
2705 if (vframe_no > StackPrintLimit) {
2706 tty->print_cr("...<more frames>...");
2713 void JavaThread::trace_stack() {
2714 if (!has_last_Java_frame()) return;
2717 RegisterMap reg_map(this);
2718 trace_stack_from(last_java_vframe(®_map));
2725 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2726 assert(reg_map != NULL, "a map must be given");
2727 frame f = last_frame();
2728 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
2729 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2735 klassOop JavaThread::security_get_caller_class(int depth) {
2736 vframeStream vfst(this);
2737 vfst.security_get_caller_frame(depth);
2738 if (!vfst.at_end()) {
2739 return vfst.method()->method_holder();
2744 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
2745 assert(thread->is_Compiler_thread(), "must be compiler thread");
2746 CompileBroker::compiler_thread_loop();
2749 // Create a CompilerThread
2750 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
2751 : JavaThread(&compiler_thread_entry) {
2756 _counters = counters;
2759 _ideal_graph_printer = NULL;
2764 // ======= Threads ========
2766 // The Threads class links together all active threads, and provides
2767 // operations over all threads. It is protected by its own Mutex
2768 // lock, which is also used in other contexts to protect thread
2769 // operations from having the thread being operated on from exiting
2770 // and going away unexpectedly (e.g., safepoint synchronization)
2772 JavaThread* Threads::_thread_list = NULL;
2773 int Threads::_number_of_threads = 0;
2774 int Threads::_number_of_non_daemon_threads = 0;
2775 int Threads::_return_code = 0;
2776 size_t JavaThread::_stack_size_at_create = 0;
2779 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
2783 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
2784 void Threads::threads_do(ThreadClosure* tc) {
2785 assert_locked_or_safepoint(Threads_lock);
2786 // ALL_JAVA_THREADS iterates through all JavaThreads
2787 ALL_JAVA_THREADS(p) {
2790 // Someday we could have a table or list of all non-JavaThreads.
2791 // For now, just manually iterate through them.
2792 tc->do_thread(VMThread::vm_thread());
2793 Universe::heap()->gc_threads_do(tc);
2794 WatcherThread *wt = WatcherThread::watcher_thread();
2795 // Strictly speaking, the following NULL check isn't sufficient to make sure
2796 // the data for WatcherThread is still valid upon being examined. However,
2797 // considering that WatchThread terminates when the VM is on the way to
2798 // exit at safepoint, the chance of the above is extremely small. The right
2799 // way to prevent termination of WatcherThread would be to acquire
2800 // Terminator_lock, but we can't do that without violating the lock rank
2801 // checking in some cases.
2805 // If CompilerThreads ever become non-JavaThreads, add them here
2808 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2810 extern void JDK_Version_init();
2813 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2815 // Initialize the output stream module
2818 // Process java launcher properties.
2819 Arguments::process_sun_java_launcher_properties(args);
2821 // Initialize the os module before using TLS
2824 // Initialize system properties.
2825 Arguments::init_system_properties();
2827 // So that JDK version can be used as a discrimintor when parsing arguments
2831 jint parse_result = Arguments::parse(args);
2832 if (parse_result != JNI_OK) return parse_result;
2834 if (PauseAtStartup) {
2838 HS_DTRACE_PROBE(hotspot, vm__init__begin);
2840 // Record VM creation timing statistics
2841 TraceVmCreationTime create_vm_timer;
2842 create_vm_timer.start();
2844 // Timing (must come after argument parsing)
2845 TraceTime timer("Create VM", TraceStartupTime);
2847 // Initialize the os module after parsing the args
2848 jint os_init_2_result = os::init_2();
2849 if (os_init_2_result != JNI_OK) return os_init_2_result;
2851 // Initialize output stream logging
2854 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2855 // Must be before create_vm_init_agents()
2856 if (Arguments::init_libraries_at_startup()) {
2857 convert_vm_init_libraries_to_agents();
2860 // Launch -agentlib/-agentpath and converted -Xrun agents
2861 if (Arguments::init_agents_at_startup()) {
2862 create_vm_init_agents();
2865 // Initialize Threads state
2866 _thread_list = NULL;
2867 _number_of_threads = 0;
2868 _number_of_non_daemon_threads = 0;
2871 ThreadLocalStorage::init();
2873 // Initialize global data structures and create system classes in heap
2876 // Attach the main thread to this os thread
2877 JavaThread* main_thread = new JavaThread();
2878 main_thread->set_thread_state(_thread_in_vm);
2879 // must do this before set_active_handles and initialize_thread_local_storage
2880 // Note: on solaris initialize_thread_local_storage() will (indirectly)
2881 // change the stack size recorded here to one based on the java thread
2882 // stacksize. This adjusted size is what is used to figure the placement
2883 // of the guard pages.
2884 main_thread->record_stack_base_and_size();
2885 main_thread->initialize_thread_local_storage();
2887 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2889 if (!main_thread->set_as_starting_thread()) {
2890 vm_shutdown_during_initialization(
2891 "Failed necessary internal allocation. Out of swap space");
2893 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2897 // Enable guard page *after* os::create_main_thread(), otherwise it would
2898 // crash Linux VM, see notes in os_linux.cpp.
2899 main_thread->create_stack_guard_pages();
2901 // Initialize Java-Leve synchronization subsystem
2902 ObjectSynchronizer::Initialize() ;
2904 // Initialize global modules
2905 jint status = init_globals();
2906 if (status != JNI_OK) {
2908 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2914 { MutexLocker mu(Threads_lock);
2915 Threads::add(main_thread);
2918 // Any JVMTI raw monitors entered in onload will transition into
2919 // real raw monitor. VM is setup enough here for raw monitor enter.
2920 JvmtiExport::transition_pending_onload_raw_monitors();
2922 if (VerifyBeforeGC &&
2923 Universe::heap()->total_collections() >= VerifyGCStartAt) {
2924 Universe::heap()->prepare_for_verify();
2925 Universe::verify(); // make sure we're starting with a clean slate
2928 // Create the VMThread
2929 { TraceTime timer("Start VMThread", TraceStartupTime);
2931 Thread* vmthread = VMThread::vm_thread();
2933 if (!os::create_thread(vmthread, os::vm_thread))
2934 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
2936 // Wait for the VM thread to become ready, and VMThread::run to initialize
2937 // Monitors can have spurious returns, must always check another state flag
2939 MutexLocker ml(Notify_lock);
2940 os::start_thread(vmthread);
2941 while (vmthread->active_handles() == NULL) {
2942 Notify_lock->wait();
2947 assert (Universe::is_fully_initialized(), "not initialized");
2950 // At this point, the Universe is initialized, but we have not executed
2951 // any byte code. Now is a good time (the only time) to dump out the
2952 // internal state of the JVM for sharing.
2954 if (DumpSharedSpaces) {
2955 Universe::heap()->preload_and_dump(CHECK_0);
2956 ShouldNotReachHere();
2959 // Always call even when there are not JVMTI environments yet, since environments
2960 // may be attached late and JVMTI must track phases of VM execution
2961 JvmtiExport::enter_start_phase();
2963 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
2964 JvmtiExport::post_vm_start();
2967 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
2969 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
2970 create_vm_init_libraries();
2973 if (InitializeJavaLangString) {
2974 initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0);
2976 warning("java.lang.String not initialized");
2979 if (AggressiveOpts) {
2981 // Forcibly initialize java/util/HashMap and mutate the private
2982 // static final "frontCacheEnabled" field before we start creating instances
2984 klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
2985 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
2987 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
2988 KlassHandle k = KlassHandle(THREAD, k_o);
2989 guarantee(k.not_null(), "Must find java/util/HashMap");
2990 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
2991 ik->initialize(CHECK_0);
2993 // Possible we might not find this field; if so, don't break
2994 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
2995 k()->bool_field_put(fd.offset(), true);
2999 if (UseStringCache) {
3000 // Forcibly initialize java/lang/StringValue and mutate the private
3001 // static final "stringCacheEnabled" field before we start creating instances
3002 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3003 // Possible that StringValue isn't present: if so, silently don't break
3005 KlassHandle k = KlassHandle(THREAD, k_o);
3006 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3007 ik->initialize(CHECK_0);
3009 // Possible we might not find this field: if so, silently don't break
3010 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3011 k()->bool_field_put(fd.offset(), true);
3017 // Initialize java_lang.System (needed before creating the thread)
3018 if (InitializeJavaLangSystem) {
3019 initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0);
3020 initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0);
3021 Handle thread_group = create_initial_thread_group(CHECK_0);
3022 Universe::set_main_thread_group(thread_group());
3023 initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0);
3024 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3025 main_thread->set_threadObj(thread_object);
3026 // Set thread status to running since main thread has
3027 // been started and running.
3028 java_lang_Thread::set_thread_status(thread_object,
3029 java_lang_Thread::RUNNABLE);
3031 // The VM preresolve methods to these classes. Make sure that get initialized
3032 initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0);
3033 initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0);
3034 // The VM creates & returns objects of this class. Make sure it's initialized.
3035 initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0);
3036 call_initializeSystemClass(CHECK_0);
3038 warning("java.lang.System not initialized");
3041 // an instance of OutOfMemory exception has been allocated earlier
3042 if (InitializeJavaLangExceptionsErrors) {
3043 initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0);
3044 initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0);
3045 initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0);
3046 initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0);
3047 initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0);
3048 initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0);
3049 initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0);
3051 warning("java.lang.OutOfMemoryError has not been initialized");
3052 warning("java.lang.NullPointerException has not been initialized");
3053 warning("java.lang.ClassCastException has not been initialized");
3054 warning("java.lang.ArrayStoreException has not been initialized");
3055 warning("java.lang.ArithmeticException has not been initialized");
3056 warning("java.lang.StackOverflowError has not been initialized");
3060 // See : bugid 4211085.
3061 // Background : the static initializer of java.lang.Compiler tries to read
3062 // property"java.compiler" and read & write property "java.vm.info".
3063 // When a security manager is installed through the command line
3064 // option "-Djava.security.manager", the above properties are not
3065 // readable and the static initializer for java.lang.Compiler fails
3066 // resulting in a NoClassDefFoundError. This can happen in any
3067 // user code which calls methods in java.lang.Compiler.
3068 // Hack : the hack is to pre-load and initialize this class, so that only
3069 // system domains are on the stack when the properties are read.
3070 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3071 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3072 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3073 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3074 // Once that is done, we should remove this hack.
3075 initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0);
3077 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3078 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3079 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3080 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3081 // This should also be taken out as soon as 4211383 gets fixed.
3082 reset_vm_info_property(CHECK_0);
3084 quicken_jni_functions();
3086 // Set flag that basic i