1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 # include "incls/_precompiled.incl"
26 # include "incls/_thread.cpp.incl"
27
28 #ifdef DTRACE_ENABLED
29
30 // Only bother with this argument setup if dtrace is available
31
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);
38
39 #define DTRACE_THREAD_PROBE(probe, javathread) \
40 { \
41 ResourceMark rm(this); \
42 int len = 0; \
43 const char* name = (javathread)->get_thread_name(); \
44 len = strlen(name); \
45 HS_DTRACE_PROBE5(hotspot, thread__##probe, \
46 name, len, \
47 java_lang_Thread::thread_id((javathread)->threadObj()), \
48 (javathread)->osthread()->thread_id(), \
49 java_lang_Thread::is_daemon((javathread)->threadObj())); \
50 }
51
52 #else // ndef DTRACE_ENABLED
53
54 #define DTRACE_THREAD_PROBE(probe, javathread)
55
56 #endif // ndef DTRACE_ENABLED
57
58 // Class hierarchy
59 // - Thread
60 // - VMThread
61 // - WatcherThread
62 // - ConcurrentMarkSweepThread
63 // - JavaThread
64 // - CompilerThread
65
66 // ======= Thread ========
67
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);
82 }
83 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
84 return aligned_addr;
85 } else {
86 return CHeapObj::operator new(size);
87 }
88 }
89
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);
94 } else {
95 CHeapObj::operator delete(p);
96 }
97 }
98
99
100 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
101 // JavaThread
102
103
104 Thread::Thread() {
105 // stack
106 _stack_base = NULL;
107 _stack_size = 0;
108 _self_raw_id = 0;
109 _lgrp_id = -1;
110 _osthread = NULL;
111
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);
118 set_osthread(NULL);
119
120 // This initial value ==> never claimed.
121 _oops_do_parity = 0;
122
123 // the handle mark links itself to last_handle_mark
124 new HandleMark(this);
125
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;
139 omFreeList = NULL ;
140 omFreeCount = 0 ;
141 omFreeProvision = 32 ;
142 omInUseList = NULL ;
143 omInUseCount = 0 ;
144
145 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
146 _suspend_flags = 0;
147
148 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
149 _hashStateX = os::random() ;
150 _hashStateY = 842502087 ;
151 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
152 _hashStateW = 273326509 ;
153
154 _OnTrap = 0 ;
155 _schedctl = NULL ;
156 _Stalled = 0 ;
157 _TypeTag = 0x2BAD ;
158
159 // Many of the following fields are effectively final - immutable
160 // Note that nascent threads can't use the Native Monitor-Mutex
161 // construct until the _MutexEvent is initialized ...
162 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
163 // we might instead use a stack of ParkEvents that we could provision on-demand.
164 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
165 // and ::Release()
166 _ParkEvent = ParkEvent::Allocate (this) ;
167 _SleepEvent = ParkEvent::Allocate (this) ;
168 _MutexEvent = ParkEvent::Allocate (this) ;
169 _MuxEvent = ParkEvent::Allocate (this) ;
170
171 #ifdef CHECK_UNHANDLED_OOPS
172 if (CheckUnhandledOops) {
173 _unhandled_oops = new UnhandledOops(this);
174 }
175 #endif // CHECK_UNHANDLED_OOPS
176 #ifdef ASSERT
177 if (UseBiasedLocking) {
178 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
179 assert(this == _real_malloc_address ||
180 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
181 "bug in forced alignment of thread objects");
182 }
183 #endif /* ASSERT */
184 }
185
186 void Thread::initialize_thread_local_storage() {
187 // Note: Make sure this method only calls
188 // non-blocking operations. Otherwise, it might not work
189 // with the thread-startup/safepoint interaction.
190
191 // During Java thread startup, safepoint code should allow this
192 // method to complete because it may need to allocate memory to
193 // store information for the new thread.
194
195 // initialize structure dependent on thread local storage
196 ThreadLocalStorage::set_thread(this);
197
198 // set up any platform-specific state.
199 os::initialize_thread();
200
201 }
202
203 void Thread::record_stack_base_and_size() {
204 set_stack_base(os::current_stack_base());
205 set_stack_size(os::current_stack_size());
206 }
207
208
209 Thread::~Thread() {
210 // Reclaim the objectmonitors from the omFreeList of the moribund thread.
211 ObjectSynchronizer::omFlush (this) ;
212
213 // deallocate data structures
214 delete resource_area();
215 // since the handle marks are using the handle area, we have to deallocated the root
216 // handle mark before deallocating the thread's handle area,
217 assert(last_handle_mark() != NULL, "check we have an element");
218 delete last_handle_mark();
219 assert(last_handle_mark() == NULL, "check we have reached the end");
220
221 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
222 // We NULL out the fields for good hygiene.
223 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
224 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
225 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
226 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
227
228 delete handle_area();
229
230 // osthread() can be NULL, if creation of thread failed.
231 if (osthread() != NULL) os::free_thread(osthread());
232
233 delete _SR_lock;
234
235 // clear thread local storage if the Thread is deleting itself
236 if (this == Thread::current()) {
237 ThreadLocalStorage::set_thread(NULL);
238 } else {
239 // In the case where we're not the current thread, invalidate all the
240 // caches in case some code tries to get the current thread or the
241 // thread that was destroyed, and gets stale information.
242 ThreadLocalStorage::invalidate_all();
243 }
244 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
245 }
246
247 // NOTE: dummy function for assertion purpose.
248 void Thread::run() {
249 ShouldNotReachHere();
250 }
251
252 #ifdef ASSERT
253 // Private method to check for dangling thread pointer
254 void check_for_dangling_thread_pointer(Thread *thread) {
255 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
256 "possibility of dangling Thread pointer");
257 }
258 #endif
259
260
261 #ifndef PRODUCT
262 // Tracing method for basic thread operations
263 void Thread::trace(const char* msg, const Thread* const thread) {
264 if (!TraceThreadEvents) return;
265 ResourceMark rm;
266 ThreadCritical tc;
267 const char *name = "non-Java thread";
268 int prio = -1;
269 if (thread->is_Java_thread()
270 && !thread->is_Compiler_thread()) {
271 // The Threads_lock must be held to get information about
272 // this thread but may not be in some situations when
273 // tracing thread events.
274 bool release_Threads_lock = false;
275 if (!Threads_lock->owned_by_self()) {
276 Threads_lock->lock();
277 release_Threads_lock = true;
278 }
279 JavaThread* jt = (JavaThread *)thread;
280 name = (char *)jt->get_thread_name();
281 oop thread_oop = jt->threadObj();
282 if (thread_oop != NULL) {
283 prio = java_lang_Thread::priority(thread_oop);
284 }
285 if (release_Threads_lock) {
286 Threads_lock->unlock();
287 }
288 }
289 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
290 }
291 #endif
292
293
294 ThreadPriority Thread::get_priority(const Thread* const thread) {
295 trace("get priority", thread);
296 ThreadPriority priority;
297 // Can return an error!
298 (void)os::get_priority(thread, priority);
299 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
300 return priority;
301 }
302
303 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
304 trace("set priority", thread);
305 debug_only(check_for_dangling_thread_pointer(thread);)
306 // Can return an error!
307 (void)os::set_priority(thread, priority);
308 }
309
310
311 void Thread::start(Thread* thread) {
312 trace("start", thread);
313 // Start is different from resume in that its safety is guaranteed by context or
314 // being called from a Java method synchronized on the Thread object.
315 if (!DisableStartThread) {
316 if (thread->is_Java_thread()) {
317 // Initialize the thread state to RUNNABLE before starting this thread.
318 // Can not set it after the thread started because we do not know the
319 // exact thread state at that time. It could be in MONITOR_WAIT or
320 // in SLEEPING or some other state.
321 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
322 java_lang_Thread::RUNNABLE);
323 }
324 os::start_thread(thread);
325 }
326 }
327
328 // Enqueue a VM_Operation to do the job for us - sometime later
329 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
330 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
331 VMThread::execute(vm_stop);
332 }
333
334
335 //
336 // Check if an external suspend request has completed (or has been
337 // cancelled). Returns true if the thread is externally suspended and
338 // false otherwise.
339 //
340 // The bits parameter returns information about the code path through
341 // the routine. Useful for debugging:
342 //
343 // set in is_ext_suspend_completed():
344 // 0x00000001 - routine was entered
345 // 0x00000010 - routine return false at end
346 // 0x00000100 - thread exited (return false)
347 // 0x00000200 - suspend request cancelled (return false)
348 // 0x00000400 - thread suspended (return true)
349 // 0x00001000 - thread is in a suspend equivalent state (return true)
350 // 0x00002000 - thread is native and walkable (return true)
351 // 0x00004000 - thread is native_trans and walkable (needed retry)
352 //
353 // set in wait_for_ext_suspend_completion():
354 // 0x00010000 - routine was entered
355 // 0x00020000 - suspend request cancelled before loop (return false)
356 // 0x00040000 - thread suspended before loop (return true)
357 // 0x00080000 - suspend request cancelled in loop (return false)
358 // 0x00100000 - thread suspended in loop (return true)
359 // 0x00200000 - suspend not completed during retry loop (return false)
360 //
361
362 // Helper class for tracing suspend wait debug bits.
363 //
364 // 0x00000100 indicates that the target thread exited before it could
365 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
366 // 0x00080000 each indicate a cancelled suspend request so they don't
367 // count as wait failures either.
368 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
369
370 class TraceSuspendDebugBits : public StackObj {
371 private:
372 JavaThread * jt;
373 bool is_wait;
374 bool called_by_wait; // meaningful when !is_wait
375 uint32_t * bits;
376
377 public:
378 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
379 uint32_t *_bits) {
380 jt = _jt;
381 is_wait = _is_wait;
382 called_by_wait = _called_by_wait;
383 bits = _bits;
384 }
385
386 ~TraceSuspendDebugBits() {
387 if (!is_wait) {
388 #if 1
389 // By default, don't trace bits for is_ext_suspend_completed() calls.
390 // That trace is very chatty.
391 return;
392 #else
393 if (!called_by_wait) {
394 // If tracing for is_ext_suspend_completed() is enabled, then only
395 // trace calls to it from wait_for_ext_suspend_completion()
396 return;
397 }
398 #endif
399 }
400
401 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
402 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
403 MutexLocker ml(Threads_lock); // needed for get_thread_name()
404 ResourceMark rm;
405
406 tty->print_cr(
407 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
408 jt->get_thread_name(), *bits);
409
410 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
411 }
412 }
413 }
414 };
415 #undef DEBUG_FALSE_BITS
416
417
418 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
419 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
420
421 bool did_trans_retry = false; // only do thread_in_native_trans retry once
422 bool do_trans_retry; // flag to force the retry
423
424 *bits |= 0x00000001;
425
426 do {
427 do_trans_retry = false;
428
429 if (is_exiting()) {
430 // Thread is in the process of exiting. This is always checked
431 // first to reduce the risk of dereferencing a freed JavaThread.
432 *bits |= 0x00000100;
433 return false;
434 }
435
436 if (!is_external_suspend()) {
437 // Suspend request is cancelled. This is always checked before
438 // is_ext_suspended() to reduce the risk of a rogue resume
439 // confusing the thread that made the suspend request.
440 *bits |= 0x00000200;
441 return false;
442 }
443
444 if (is_ext_suspended()) {
445 // thread is suspended
446 *bits |= 0x00000400;
447 return true;
448 }
449
450 // Now that we no longer do hard suspends of threads running
451 // native code, the target thread can be changing thread state
452 // while we are in this routine:
453 //
454 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
455 //
456 // We save a copy of the thread state as observed at this moment
457 // and make our decision about suspend completeness based on the
458 // copy. This closes the race where the thread state is seen as
459 // _thread_in_native_trans in the if-thread_blocked check, but is
460 // seen as _thread_blocked in if-thread_in_native_trans check.
461 JavaThreadState save_state = thread_state();
462
463 if (save_state == _thread_blocked && is_suspend_equivalent()) {
464 // If the thread's state is _thread_blocked and this blocking
465 // condition is known to be equivalent to a suspend, then we can
466 // consider the thread to be externally suspended. This means that
467 // the code that sets _thread_blocked has been modified to do
468 // self-suspension if the blocking condition releases. We also
469 // used to check for CONDVAR_WAIT here, but that is now covered by
470 // the _thread_blocked with self-suspension check.
471 //
472 // Return true since we wouldn't be here unless there was still an
473 // external suspend request.
474 *bits |= 0x00001000;
475 return true;
476 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
477 // Threads running native code will self-suspend on native==>VM/Java
478 // transitions. If its stack is walkable (should always be the case
479 // unless this function is called before the actual java_suspend()
480 // call), then the wait is done.
481 *bits |= 0x00002000;
482 return true;
483 } else if (!called_by_wait && !did_trans_retry &&
484 save_state == _thread_in_native_trans &&
485 frame_anchor()->walkable()) {
486 // The thread is transitioning from thread_in_native to another
487 // thread state. check_safepoint_and_suspend_for_native_trans()
488 // will force the thread to self-suspend. If it hasn't gotten
489 // there yet we may have caught the thread in-between the native
490 // code check above and the self-suspend. Lucky us. If we were
491 // called by wait_for_ext_suspend_completion(), then it
492 // will be doing the retries so we don't have to.
493 //
494 // Since we use the saved thread state in the if-statement above,
495 // there is a chance that the thread has already transitioned to
496 // _thread_blocked by the time we get here. In that case, we will
497 // make a single unnecessary pass through the logic below. This
498 // doesn't hurt anything since we still do the trans retry.
499
500 *bits |= 0x00004000;
501
502 // Once the thread leaves thread_in_native_trans for another
503 // thread state, we break out of this retry loop. We shouldn't
504 // need this flag to prevent us from getting back here, but
505 // sometimes paranoia is good.
506 did_trans_retry = true;
507
508 // We wait for the thread to transition to a more usable state.
509 for (int i = 1; i <= SuspendRetryCount; i++) {
510 // We used to do an "os::yield_all(i)" call here with the intention
511 // that yielding would increase on each retry. However, the parameter
512 // is ignored on Linux which means the yield didn't scale up. Waiting
513 // on the SR_lock below provides a much more predictable scale up for
514 // the delay. It also provides a simple/direct point to check for any
515 // safepoint requests from the VMThread
516
517 // temporarily drops SR_lock while doing wait with safepoint check
518 // (if we're a JavaThread - the WatcherThread can also call this)
519 // and increase delay with each retry
520 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
521
522 // check the actual thread state instead of what we saved above
523 if (thread_state() != _thread_in_native_trans) {
524 // the thread has transitioned to another thread state so
525 // try all the checks (except this one) one more time.
526 do_trans_retry = true;
527 break;
528 }
529 } // end retry loop
530
531
532 }
533 } while (do_trans_retry);
534
535 *bits |= 0x00000010;
536 return false;
537 }
538
539 //
540 // Wait for an external suspend request to complete (or be cancelled).
541 // Returns true if the thread is externally suspended and false otherwise.
542 //
543 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
544 uint32_t *bits) {
545 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
546 false /* !called_by_wait */, bits);
547
548 // local flag copies to minimize SR_lock hold time
549 bool is_suspended;
550 bool pending;
551 uint32_t reset_bits;
552
553 // set a marker so is_ext_suspend_completed() knows we are the caller
554 *bits |= 0x00010000;
555
556 // We use reset_bits to reinitialize the bits value at the top of
557 // each retry loop. This allows the caller to make use of any
558 // unused bits for their own marking purposes.
559 reset_bits = *bits;
560
561 {
562 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
563 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
564 delay, bits);
565 pending = is_external_suspend();
566 }
567 // must release SR_lock to allow suspension to complete
568
569 if (!pending) {
570 // A cancelled suspend request is the only false return from
571 // is_ext_suspend_completed() that keeps us from entering the
572 // retry loop.
573 *bits |= 0x00020000;
574 return false;
575 }
576
577 if (is_suspended) {
578 *bits |= 0x00040000;
579 return true;
580 }
581
582 for (int i = 1; i <= retries; i++) {
583 *bits = reset_bits; // reinit to only track last retry
584
585 // We used to do an "os::yield_all(i)" call here with the intention
586 // that yielding would increase on each retry. However, the parameter
587 // is ignored on Linux which means the yield didn't scale up. Waiting
588 // on the SR_lock below provides a much more predictable scale up for
589 // the delay. It also provides a simple/direct point to check for any
590 // safepoint requests from the VMThread
591
592 {
593 MutexLocker ml(SR_lock());
594 // wait with safepoint check (if we're a JavaThread - the WatcherThread
595 // can also call this) and increase delay with each retry
596 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
597
598 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
599 delay, bits);
600
601 // It is possible for the external suspend request to be cancelled
602 // (by a resume) before the actual suspend operation is completed.
603 // Refresh our local copy to see if we still need to wait.
604 pending = is_external_suspend();
605 }
606
607 if (!pending) {
608 // A cancelled suspend request is the only false return from
609 // is_ext_suspend_completed() that keeps us from staying in the
610 // retry loop.
611 *bits |= 0x00080000;
612 return false;
613 }
614
615 if (is_suspended) {
616 *bits |= 0x00100000;
617 return true;
618 }
619 } // end retry loop
620
621 // thread did not suspend after all our retries
622 *bits |= 0x00200000;
623 return false;
624 }
625
626 #ifndef PRODUCT
627 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
628
629 // This should not need to be atomic as the only way for simultaneous
630 // updates is via interrupts. Even then this should be rare or non-existant
631 // and we don't care that much anyway.
632
633 int index = _jmp_ring_index;
634 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
635 _jmp_ring[index]._target = (intptr_t) target;
636 _jmp_ring[index]._instruction = (intptr_t) instr;
637 _jmp_ring[index]._file = file;
638 _jmp_ring[index]._line = line;
639 }
640 #endif /* PRODUCT */
641
642 // Called by flat profiler
643 // Callers have already called wait_for_ext_suspend_completion
644 // The assertion for that is currently too complex to put here:
645 bool JavaThread::profile_last_Java_frame(frame* _fr) {
646 bool gotframe = false;
647 // self suspension saves needed state.
648 if (has_last_Java_frame() && _anchor.walkable()) {
649 *_fr = pd_last_frame();
650 gotframe = true;
651 }
652 return gotframe;
653 }
654
655 void Thread::interrupt(Thread* thread) {
656 trace("interrupt", thread);
657 debug_only(check_for_dangling_thread_pointer(thread);)
658 os::interrupt(thread);
659 }
660
661 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
662 trace("is_interrupted", thread);
663 debug_only(check_for_dangling_thread_pointer(thread);)
664 // Note: If clear_interrupted==false, this simply fetches and
665 // returns the value of the field osthread()->interrupted().
666 return os::is_interrupted(thread, clear_interrupted);
667 }
668
669
670 // GC Support
671 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
672 jint thread_parity = _oops_do_parity;
673 if (thread_parity != strong_roots_parity) {
674 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
675 if (res == thread_parity) return true;
676 else {
677 guarantee(res == strong_roots_parity, "Or else what?");
678 assert(SharedHeap::heap()->n_par_threads() > 0,
679 "Should only fail when parallel.");
680 return false;
681 }
682 }
683 assert(SharedHeap::heap()->n_par_threads() > 0,
684 "Should only fail when parallel.");
685 return false;
686 }
687
688 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
689 active_handles()->oops_do(f);
690 // Do oop for ThreadShadow
691 f->do_oop((oop*)&_pending_exception);
692 handle_area()->oops_do(f);
693 }
694
695 void Thread::nmethods_do(CodeBlobClosure* cf) {
696 // no nmethods in a generic thread...
697 }
698
699 void Thread::print_on(outputStream* st) const {
700 // get_priority assumes osthread initialized
701 if (osthread() != NULL) {
702 st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this);
703 osthread()->print_on(st);
704 }
705 debug_only(if (WizardMode) print_owned_locks_on(st);)
706 }
707
708 // Thread::print_on_error() is called by fatal error handler. Don't use
709 // any lock or allocate memory.
710 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
711 if (is_VM_thread()) st->print("VMThread");
712 else if (is_Compiler_thread()) st->print("CompilerThread");
713 else if (is_Java_thread()) st->print("JavaThread");
714 else if (is_GC_task_thread()) st->print("GCTaskThread");
715 else if (is_Watcher_thread()) st->print("WatcherThread");
716 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
717 else st->print("Thread");
718
719 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
720 _stack_base - _stack_size, _stack_base);
721
722 if (osthread()) {
723 st->print(" [id=%d]", osthread()->thread_id());
724 }
725 }
726
727 #ifdef ASSERT
728 void Thread::print_owned_locks_on(outputStream* st) const {
729 Monitor *cur = _owned_locks;
730 if (cur == NULL) {
731 st->print(" (no locks) ");
732 } else {
733 st->print_cr(" Locks owned:");
734 while(cur) {
735 cur->print_on(st);
736 cur = cur->next();
737 }
738 }
739 }
740
741 static int ref_use_count = 0;
742
743 bool Thread::owns_locks_but_compiled_lock() const {
744 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
745 if (cur != Compile_lock) return true;
746 }
747 return false;
748 }
749
750
751 #endif
752
753 #ifndef PRODUCT
754
755 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
756 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
757 // no threads which allow_vm_block's are held
758 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
759 // Check if current thread is allowed to block at a safepoint
760 if (!(_allow_safepoint_count == 0))
761 fatal("Possible safepoint reached by thread that does not allow it");
762 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
763 fatal("LEAF method calling lock?");
764 }
765
766 #ifdef ASSERT
767 if (potential_vm_operation && is_Java_thread()
768 && !Universe::is_bootstrapping()) {
769 // Make sure we do not hold any locks that the VM thread also uses.
770 // This could potentially lead to deadlocks
771 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
772 // Threads_lock is special, since the safepoint synchronization will not start before this is
773 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
774 // since it is used to transfer control between JavaThreads and the VMThread
775 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
776 if ( (cur->allow_vm_block() &&
777 cur != Threads_lock &&
778 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
779 cur != VMOperationRequest_lock &&
780 cur != VMOperationQueue_lock) ||
781 cur->rank() == Mutex::special) {
782 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
783 }
784 }
785 }
786
787 if (GCALotAtAllSafepoints) {
788 // We could enter a safepoint here and thus have a gc
789 InterfaceSupport::check_gc_alot();
790 }
791 #endif
792 }
793 #endif
794
795 bool Thread::is_in_stack(address adr) const {
796 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
797 address end = os::current_stack_pointer();
798 if (stack_base() >= adr && adr >= end) return true;
799
800 return false;
801 }
802
803
804 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
805 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
806 // used for compilation in the future. If that change is made, the need for these methods
807 // should be revisited, and they should be removed if possible.
808
809 bool Thread::is_lock_owned(address adr) const {
810 return on_local_stack(adr);
811 }
812
813 bool Thread::set_as_starting_thread() {
814 // NOTE: this must be called inside the main thread.
815 return os::create_main_thread((JavaThread*)this);
816 }
817
818 static void initialize_class(symbolHandle class_name, TRAPS) {
819 klassOop klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
820 instanceKlass::cast(klass)->initialize(CHECK);
821 }
822
823
824 // Creates the initial ThreadGroup
825 static Handle create_initial_thread_group(TRAPS) {
826 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH);
827 instanceKlassHandle klass (THREAD, k);
828
829 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
830 {
831 JavaValue result(T_VOID);
832 JavaCalls::call_special(&result,
833 system_instance,
834 klass,
835 vmSymbolHandles::object_initializer_name(),
836 vmSymbolHandles::void_method_signature(),
837 CHECK_NH);
838 }
839 Universe::set_system_thread_group(system_instance());
840
841 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
842 {
843 JavaValue result(T_VOID);
844 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
845 JavaCalls::call_special(&result,
846 main_instance,
847 klass,
848 vmSymbolHandles::object_initializer_name(),
849 vmSymbolHandles::threadgroup_string_void_signature(),
850 system_instance,
851 string,
852 CHECK_NH);
853 }
854 return main_instance;
855 }
856
857 // Creates the initial Thread
858 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
859 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL);
860 instanceKlassHandle klass (THREAD, k);
861 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
862
863 java_lang_Thread::set_thread(thread_oop(), thread);
864 java_lang_Thread::set_priority(thread_oop(), NormPriority);
865 thread->set_threadObj(thread_oop());
866
867 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
868
869 JavaValue result(T_VOID);
870 JavaCalls::call_special(&result, thread_oop,
871 klass,
872 vmSymbolHandles::object_initializer_name(),
873 vmSymbolHandles::threadgroup_string_void_signature(),
874 thread_group,
875 string,
876 CHECK_NULL);
877 return thread_oop();
878 }
879
880 static void call_initializeSystemClass(TRAPS) {
881 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
882 instanceKlassHandle klass (THREAD, k);
883
884 JavaValue result(T_VOID);
885 JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(),
886 vmSymbolHandles::void_method_signature(), CHECK);
887 }
888
889 #ifdef KERNEL
890 static void set_jkernel_boot_classloader_hook(TRAPS) {
891 klassOop k = SystemDictionary::sun_jkernel_DownloadManager_klass();
892 instanceKlassHandle klass (THREAD, k);
893
894 if (k == NULL) {
895 // sun.jkernel.DownloadManager may not present in the JDK; just return
896 return;
897 }
898
899 JavaValue result(T_VOID);
900 JavaCalls::call_static(&result, klass, vmSymbolHandles::setBootClassLoaderHook_name(),
901 vmSymbolHandles::void_method_signature(), CHECK);
902 }
903 #endif // KERNEL
904
905 static void reset_vm_info_property(TRAPS) {
906 // the vm info string
907 ResourceMark rm(THREAD);
908 const char *vm_info = VM_Version::vm_info_string();
909
910 // java.lang.System class
911 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
912 instanceKlassHandle klass (THREAD, k);
913
914 // setProperty arguments
915 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
916 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
917
918 // return value
919 JavaValue r(T_OBJECT);
920
921 // public static String setProperty(String key, String value);
922 JavaCalls::call_static(&r,
923 klass,
924 vmSymbolHandles::setProperty_name(),
925 vmSymbolHandles::string_string_string_signature(),
926 key_str,
927 value_str,
928 CHECK);
929 }
930
931
932 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
933 assert(thread_group.not_null(), "thread group should be specified");
934 assert(threadObj() == NULL, "should only create Java thread object once");
935
936 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
937 instanceKlassHandle klass (THREAD, k);
938 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
939
940 java_lang_Thread::set_thread(thread_oop(), this);
941 java_lang_Thread::set_priority(thread_oop(), NormPriority);
942 set_threadObj(thread_oop());
943
944 JavaValue result(T_VOID);
945 if (thread_name != NULL) {
946 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
947 // Thread gets assigned specified name and null target
948 JavaCalls::call_special(&result,
949 thread_oop,
950 klass,
951 vmSymbolHandles::object_initializer_name(),
952 vmSymbolHandles::threadgroup_string_void_signature(),
953 thread_group, // Argument 1
954 name, // Argument 2
955 THREAD);
956 } else {
957 // Thread gets assigned name "Thread-nnn" and null target
958 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
959 JavaCalls::call_special(&result,
960 thread_oop,
961 klass,
962 vmSymbolHandles::object_initializer_name(),
963 vmSymbolHandles::threadgroup_runnable_void_signature(),
964 thread_group, // Argument 1
965 Handle(), // Argument 2
966 THREAD);
967 }
968
969
970 if (daemon) {
971 java_lang_Thread::set_daemon(thread_oop());
972 }
973
974 if (HAS_PENDING_EXCEPTION) {
975 return;
976 }
977
978 KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
979 Handle threadObj(this, this->threadObj());
980
981 JavaCalls::call_special(&result,
982 thread_group,
983 group,
984 vmSymbolHandles::add_method_name(),
985 vmSymbolHandles::thread_void_signature(),
986 threadObj, // Arg 1
987 THREAD);
988
989
990 }
991
992 // NamedThread -- non-JavaThread subclasses with multiple
993 // uniquely named instances should derive from this.
994 NamedThread::NamedThread() : Thread() {
995 _name = NULL;
996 _processed_thread = NULL;
997 }
998
999 NamedThread::~NamedThread() {
1000 if (_name != NULL) {
1001 FREE_C_HEAP_ARRAY(char, _name);
1002 _name = NULL;
1003 }
1004 }
1005
1006 void NamedThread::set_name(const char* format, ...) {
1007 guarantee(_name == NULL, "Only get to set name once.");
1008 _name = NEW_C_HEAP_ARRAY(char, max_name_len);
1009 guarantee(_name != NULL, "alloc failure");
1010 va_list ap;
1011 va_start(ap, format);
1012 jio_vsnprintf(_name, max_name_len, format, ap);
1013 va_end(ap);
1014 }
1015
1016 // ======= WatcherThread ========
1017
1018 // The watcher thread exists to simulate timer interrupts. It should
1019 // be replaced by an abstraction over whatever native support for
1020 // timer interrupts exists on the platform.
1021
1022 WatcherThread* WatcherThread::_watcher_thread = NULL;
1023 volatile bool WatcherThread::_should_terminate = false;
1024
1025 WatcherThread::WatcherThread() : Thread() {
1026 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1027 if (os::create_thread(this, os::watcher_thread)) {
1028 _watcher_thread = this;
1029
1030 // Set the watcher thread to the highest OS priority which should not be
1031 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1032 // is created. The only normal thread using this priority is the reference
1033 // handler thread, which runs for very short intervals only.
1034 // If the VMThread's priority is not lower than the WatcherThread profiling
1035 // will be inaccurate.
1036 os::set_priority(this, MaxPriority);
1037 if (!DisableStartThread) {
1038 os::start_thread(this);
1039 }
1040 }
1041 }
1042
1043 void WatcherThread::run() {
1044 assert(this == watcher_thread(), "just checking");
1045
1046 this->record_stack_base_and_size();
1047 this->initialize_thread_local_storage();
1048 this->set_active_handles(JNIHandleBlock::allocate_block());
1049 while(!_should_terminate) {
1050 assert(watcher_thread() == Thread::current(), "thread consistency check");
1051 assert(watcher_thread() == this, "thread consistency check");
1052
1053 // Calculate how long it'll be until the next PeriodicTask work
1054 // should be done, and sleep that amount of time.
1055 size_t time_to_wait = PeriodicTask::time_to_wait();
1056
1057 // we expect this to timeout - we only ever get unparked when
1058 // we should terminate
1059 {
1060 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1061
1062 jlong prev_time = os::javaTimeNanos();
1063 for (;;) {
1064 int res= _SleepEvent->park(time_to_wait);
1065 if (res == OS_TIMEOUT || _should_terminate)
1066 break;
1067 // spurious wakeup of some kind
1068 jlong now = os::javaTimeNanos();
1069 time_to_wait -= (now - prev_time) / 1000000;
1070 if (time_to_wait <= 0)
1071 break;
1072 prev_time = now;
1073 }
1074 }
1075
1076 if (is_error_reported()) {
1077 // A fatal error has happened, the error handler(VMError::report_and_die)
1078 // should abort JVM after creating an error log file. However in some
1079 // rare cases, the error handler itself might deadlock. Here we try to
1080 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1081 //
1082 // This code is in WatcherThread because WatcherThread wakes up
1083 // periodically so the fatal error handler doesn't need to do anything;
1084 // also because the WatcherThread is less likely to crash than other
1085 // threads.
1086
1087 for (;;) {
1088 if (!ShowMessageBoxOnError
1089 && (OnError == NULL || OnError[0] == '\0')
1090 && Arguments::abort_hook() == NULL) {
1091 os::sleep(this, 2 * 60 * 1000, false);
1092 fdStream err(defaultStream::output_fd());
1093 err.print_raw_cr("# [ timer expired, abort... ]");
1094 // skip atexit/vm_exit/vm_abort hooks
1095 os::die();
1096 }
1097
1098 // Wake up 5 seconds later, the fatal handler may reset OnError or
1099 // ShowMessageBoxOnError when it is ready to abort.
1100 os::sleep(this, 5 * 1000, false);
1101 }
1102 }
1103
1104 PeriodicTask::real_time_tick(time_to_wait);
1105
1106 // If we have no more tasks left due to dynamic disenrollment,
1107 // shut down the thread since we don't currently support dynamic enrollment
1108 if (PeriodicTask::num_tasks() == 0) {
1109 _should_terminate = true;
1110 }
1111 }
1112
1113 // Signal that it is terminated
1114 {
1115 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1116 _watcher_thread = NULL;
1117 Terminator_lock->notify();
1118 }
1119
1120 // Thread destructor usually does this..
1121 ThreadLocalStorage::set_thread(NULL);
1122 }
1123
1124 void WatcherThread::start() {
1125 if (watcher_thread() == NULL) {
1126 _should_terminate = false;
1127 // Create the single instance of WatcherThread
1128 new WatcherThread();
1129 }
1130 }
1131
1132 void WatcherThread::stop() {
1133 // it is ok to take late safepoints here, if needed
1134 MutexLocker mu(Terminator_lock);
1135 _should_terminate = true;
1136 OrderAccess::fence(); // ensure WatcherThread sees update in main loop
1137
1138 Thread* watcher = watcher_thread();
1139 if (watcher != NULL)
1140 watcher->_SleepEvent->unpark();
1141
1142 while(watcher_thread() != NULL) {
1143 // This wait should make safepoint checks, wait without a timeout,
1144 // and wait as a suspend-equivalent condition.
1145 //
1146 // Note: If the FlatProfiler is running, then this thread is waiting
1147 // for the WatcherThread to terminate and the WatcherThread, via the
1148 // FlatProfiler task, is waiting for the external suspend request on
1149 // this thread to complete. wait_for_ext_suspend_completion() will
1150 // eventually timeout, but that takes time. Making this wait a
1151 // suspend-equivalent condition solves that timeout problem.
1152 //
1153 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1154 Mutex::_as_suspend_equivalent_flag);
1155 }
1156 }
1157
1158 void WatcherThread::print_on(outputStream* st) const {
1159 st->print("\"%s\" ", name());
1160 Thread::print_on(st);
1161 st->cr();
1162 }
1163
1164 // ======= JavaThread ========
1165
1166 // A JavaThread is a normal Java thread
1167
1168 void JavaThread::initialize() {
1169 // Initialize fields
1170
1171 // Set the claimed par_id to -1 (ie not claiming any par_ids)
1172 set_claimed_par_id(-1);
1173
1174 set_saved_exception_pc(NULL);
1175 set_threadObj(NULL);
1176 _anchor.clear();
1177 set_entry_point(NULL);
1178 set_jni_functions(jni_functions());
1179 set_callee_target(NULL);
1180 set_vm_result(NULL);
1181 set_vm_result_2(NULL);
1182 set_vframe_array_head(NULL);
1183 set_vframe_array_last(NULL);
1184 set_deferred_locals(NULL);
1185 set_deopt_mark(NULL);
1186 clear_must_deopt_id();
1187 set_monitor_chunks(NULL);
1188 set_next(NULL);
1189 set_thread_state(_thread_new);
1190 _terminated = _not_terminated;
1191 _privileged_stack_top = NULL;
1192 _array_for_gc = NULL;
1193 _suspend_equivalent = false;
1194 _in_deopt_handler = 0;
1195 _doing_unsafe_access = false;
1196 _stack_guard_state = stack_guard_unused;
1197 _exception_oop = NULL;
1198 _exception_pc = 0;
1199 _exception_handler_pc = 0;
1200 _exception_stack_size = 0;
1201 _jvmti_thread_state= NULL;
1202 _should_post_on_exceptions_flag = JNI_FALSE;
1203 _jvmti_get_loaded_classes_closure = NULL;
1204 _interp_only_mode = 0;
1205 _special_runtime_exit_condition = _no_async_condition;
1206 _pending_async_exception = NULL;
1207 _is_compiling = false;
1208 _thread_stat = NULL;
1209 _thread_stat = new ThreadStatistics();
1210 _blocked_on_compilation = false;
1211 _jni_active_critical = 0;
1212 _do_not_unlock_if_synchronized = false;
1213 _cached_monitor_info = NULL;
1214 _parker = Parker::Allocate(this) ;
1215
1216 #ifndef PRODUCT
1217 _jmp_ring_index = 0;
1218 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1219 record_jump(NULL, NULL, NULL, 0);
1220 }
1221 #endif /* PRODUCT */
1222
1223 set_thread_profiler(NULL);
1224 if (FlatProfiler::is_active()) {
1225 // This is where we would decide to either give each thread it's own profiler
1226 // or use one global one from FlatProfiler,
1227 // or up to some count of the number of profiled threads, etc.
1228 ThreadProfiler* pp = new ThreadProfiler();
1229 pp->engage();
1230 set_thread_profiler(pp);
1231 }
1232
1233 // Setup safepoint state info for this thread
1234 ThreadSafepointState::create(this);
1235
1236 debug_only(_java_call_counter = 0);
1237
1238 // JVMTI PopFrame support
1239 _popframe_condition = popframe_inactive;
1240 _popframe_preserved_args = NULL;
1241 _popframe_preserved_args_size = 0;
1242
1243 pd_initialize();
1244 }
1245
1246 #ifndef SERIALGC
1247 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1248 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1249 #endif // !SERIALGC
1250
1251 JavaThread::JavaThread(bool is_attaching) :
1252 Thread()
1253 #ifndef SERIALGC
1254 , _satb_mark_queue(&_satb_mark_queue_set),
1255 _dirty_card_queue(&_dirty_card_queue_set)
1256 #endif // !SERIALGC
1257 {
1258 initialize();
1259 _is_attaching = is_attaching;
1260 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor");
1261 }
1262
1263 bool JavaThread::reguard_stack(address cur_sp) {
1264 if (_stack_guard_state != stack_guard_yellow_disabled) {
1265 return true; // Stack already guarded or guard pages not needed.
1266 }
1267
1268 if (register_stack_overflow()) {
1269 // For those architectures which have separate register and
1270 // memory stacks, we must check the register stack to see if
1271 // it has overflowed.
1272 return false;
1273 }
1274
1275 // Java code never executes within the yellow zone: the latter is only
1276 // there to provoke an exception during stack banging. If java code
1277 // is executing there, either StackShadowPages should be larger, or
1278 // some exception code in c1, c2 or the interpreter isn't unwinding
1279 // when it should.
1280 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1281
1282 enable_stack_yellow_zone();
1283 return true;
1284 }
1285
1286 bool JavaThread::reguard_stack(void) {
1287 return reguard_stack(os::current_stack_pointer());
1288 }
1289
1290
1291 void JavaThread::block_if_vm_exited() {
1292 if (_terminated == _vm_exited) {
1293 // _vm_exited is set at safepoint, and Threads_lock is never released
1294 // we will block here forever
1295 Threads_lock->lock_without_safepoint_check();
1296 ShouldNotReachHere();
1297 }
1298 }
1299
1300
1301 // Remove this ifdef when C1 is ported to the compiler interface.
1302 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1303
1304 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1305 Thread()
1306 #ifndef SERIALGC
1307 , _satb_mark_queue(&_satb_mark_queue_set),
1308 _dirty_card_queue(&_dirty_card_queue_set)
1309 #endif // !SERIALGC
1310 {
1311 if (TraceThreadEvents) {
1312 tty->print_cr("creating thread %p", this);
1313 }
1314 initialize();
1315 _is_attaching = false;
1316 set_entry_point(entry_point);
1317 // Create the native thread itself.
1318 // %note runtime_23
1319 os::ThreadType thr_type = os::java_thread;
1320 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1321 os::java_thread;
1322 os::create_thread(this, thr_type, stack_sz);
1323
1324 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1325 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1326 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1327 // the exception consists of creating the exception object & initializing it, initialization
1328 // will leave the VM via a JavaCall and then all locks must be unlocked).
1329 //
1330 // The thread is still suspended when we reach here. Thread must be explicit started
1331 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1332 // by calling Threads:add. The reason why this is not done here, is because the thread
1333 // object must be fully initialized (take a look at JVM_Start)
1334 }
1335
1336 JavaThread::~JavaThread() {
1337 if (TraceThreadEvents) {
1338 tty->print_cr("terminate thread %p", this);
1339 }
1340
1341 // JSR166 -- return the parker to the free list
1342 Parker::Release(_parker);
1343 _parker = NULL ;
1344
1345 // Free any remaining previous UnrollBlock
1346 vframeArray* old_array = vframe_array_last();
1347
1348 if (old_array != NULL) {
1349 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1350 old_array->set_unroll_block(NULL);
1351 delete old_info;
1352 delete old_array;
1353 }
1354
1355 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1356 if (deferred != NULL) {
1357 // This can only happen if thread is destroyed before deoptimization occurs.
1358 assert(deferred->length() != 0, "empty array!");
1359 do {
1360 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1361 deferred->remove_at(0);
1362 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1363 delete dlv;
1364 } while (deferred->length() != 0);
1365 delete deferred;
1366 }
1367
1368 // All Java related clean up happens in exit
1369 ThreadSafepointState::destroy(this);
1370 if (_thread_profiler != NULL) delete _thread_profiler;
1371 if (_thread_stat != NULL) delete _thread_stat;
1372 }
1373
1374
1375 // The first routine called by a new Java thread
1376 void JavaThread::run() {
1377 // initialize thread-local alloc buffer related fields
1378 this->initialize_tlab();
1379
1380 // used to test validitity of stack trace backs
1381 this->record_base_of_stack_pointer();
1382
1383 // Record real stack base and size.
1384 this->record_stack_base_and_size();
1385
1386 // Initialize thread local storage; set before calling MutexLocker
1387 this->initialize_thread_local_storage();
1388
1389 this->create_stack_guard_pages();
1390
1391 this->cache_global_variables();
1392
1393 // Thread is now sufficient initialized to be handled by the safepoint code as being
1394 // in the VM. Change thread state from _thread_new to _thread_in_vm
1395 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1396
1397 assert(JavaThread::current() == this, "sanity check");
1398 assert(!Thread::current()->owns_locks(), "sanity check");
1399
1400 DTRACE_THREAD_PROBE(start, this);
1401
1402 // This operation might block. We call that after all safepoint checks for a new thread has
1403 // been completed.
1404 this->set_active_handles(JNIHandleBlock::allocate_block());
1405
1406 if (JvmtiExport::should_post_thread_life()) {
1407 JvmtiExport::post_thread_start(this);
1408 }
1409
1410 // We call another function to do the rest so we are sure that the stack addresses used
1411 // from there will be lower than the stack base just computed
1412 thread_main_inner();
1413
1414 // Note, thread is no longer valid at this point!
1415 }
1416
1417
1418 void JavaThread::thread_main_inner() {
1419 assert(JavaThread::current() == this, "sanity check");
1420 assert(this->threadObj() != NULL, "just checking");
1421
1422 // Execute thread entry point. If this thread is being asked to restart,
1423 // or has been stopped before starting, do not reexecute entry point.
1424 // Note: Due to JVM_StopThread we can have pending exceptions already!
1425 if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) {
1426 // enter the thread's entry point only if we have no pending exceptions
1427 HandleMark hm(this);
1428 this->entry_point()(this, this);
1429 }
1430
1431 DTRACE_THREAD_PROBE(stop, this);
1432
1433 this->exit(false);
1434 delete this;
1435 }
1436
1437
1438 static void ensure_join(JavaThread* thread) {
1439 // We do not need to grap the Threads_lock, since we are operating on ourself.
1440 Handle threadObj(thread, thread->threadObj());
1441 assert(threadObj.not_null(), "java thread object must exist");
1442 ObjectLocker lock(threadObj, thread);
1443 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1444 thread->clear_pending_exception();
1445 // It is of profound importance that we set the stillborn bit and reset the thread object,
1446 // before we do the notify. Since, changing these two variable will make JVM_IsAlive return
1447 // false. So in case another thread is doing a join on this thread , it will detect that the thread
1448 // is dead when it gets notified.
1449 java_lang_Thread::set_stillborn(threadObj());
1450 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1451 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1452 java_lang_Thread::set_thread(threadObj(), NULL);
1453 lock.notify_all(thread);
1454 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1455 thread->clear_pending_exception();
1456 }
1457
1458
1459 // For any new cleanup additions, please check to see if they need to be applied to
1460 // cleanup_failed_attach_current_thread as well.
1461 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1462 assert(this == JavaThread::current(), "thread consistency check");
1463 if (!InitializeJavaLangSystem) return;
1464
1465 HandleMark hm(this);
1466 Handle uncaught_exception(this, this->pending_exception());
1467 this->clear_pending_exception();
1468 Handle threadObj(this, this->threadObj());
1469 assert(threadObj.not_null(), "Java thread object should be created");
1470
1471 if (get_thread_profiler() != NULL) {
1472 get_thread_profiler()->disengage();
1473 ResourceMark rm;
1474 get_thread_profiler()->print(get_thread_name());
1475 }
1476
1477
1478 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1479 {
1480 EXCEPTION_MARK;
1481
1482 CLEAR_PENDING_EXCEPTION;
1483 }
1484 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1485 // has to be fixed by a runtime query method
1486 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1487 // JSR-166: change call from from ThreadGroup.uncaughtException to
1488 // java.lang.Thread.dispatchUncaughtException
1489 if (uncaught_exception.not_null()) {
1490 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1491 Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT",
1492 (address)uncaught_exception(), (address)threadObj(), (address)group());
1493 {
1494 EXCEPTION_MARK;
1495 // Check if the method Thread.dispatchUncaughtException() exists. If so
1496 // call it. Otherwise we have an older library without the JSR-166 changes,
1497 // so call ThreadGroup.uncaughtException()
1498 KlassHandle recvrKlass(THREAD, threadObj->klass());
1499 CallInfo callinfo;
1500 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1501 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1502 vmSymbolHandles::dispatchUncaughtException_name(),
1503 vmSymbolHandles::throwable_void_signature(),
1504 KlassHandle(), false, false, THREAD);
1505 CLEAR_PENDING_EXCEPTION;
1506 methodHandle method = callinfo.selected_method();
1507 if (method.not_null()) {
1508 JavaValue result(T_VOID);
1509 JavaCalls::call_virtual(&result,
1510 threadObj, thread_klass,
1511 vmSymbolHandles::dispatchUncaughtException_name(),
1512 vmSymbolHandles::throwable_void_signature(),
1513 uncaught_exception,
1514 THREAD);
1515 } else {
1516 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1517 JavaValue result(T_VOID);
1518 JavaCalls::call_virtual(&result,
1519 group, thread_group,
1520 vmSymbolHandles::uncaughtException_name(),
1521 vmSymbolHandles::thread_throwable_void_signature(),
1522 threadObj, // Arg 1
1523 uncaught_exception, // Arg 2
1524 THREAD);
1525 }
1526 CLEAR_PENDING_EXCEPTION;
1527 }
1528 }
1529
1530 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1531 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1532 // is deprecated anyhow.
1533 { int count = 3;
1534 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1535 EXCEPTION_MARK;
1536 JavaValue result(T_VOID);
1537 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1538 JavaCalls::call_virtual(&result,
1539 threadObj, thread_klass,
1540 vmSymbolHandles::exit_method_name(),
1541 vmSymbolHandles::void_method_signature(),
1542 THREAD);
1543 CLEAR_PENDING_EXCEPTION;
1544 }
1545 }
1546
1547 // notify JVMTI
1548 if (JvmtiExport::should_post_thread_life()) {
1549 JvmtiExport::post_thread_end(this);
1550 }
1551
1552 // We have notified the agents that we are exiting, before we go on,
1553 // we must check for a pending external suspend request and honor it
1554 // in order to not surprise the thread that made the suspend request.
1555 while (true) {
1556 {
1557 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1558 if (!is_external_suspend()) {
1559 set_terminated(_thread_exiting);
1560 ThreadService::current_thread_exiting(this);
1561 break;
1562 }
1563 // Implied else:
1564 // Things get a little tricky here. We have a pending external
1565 // suspend request, but we are holding the SR_lock so we
1566 // can't just self-suspend. So we temporarily drop the lock
1567 // and then self-suspend.
1568 }
1569
1570 ThreadBlockInVM tbivm(this);
1571 java_suspend_self();
1572
1573 // We're done with this suspend request, but we have to loop around
1574 // and check again. Eventually we will get SR_lock without a pending
1575 // external suspend request and will be able to mark ourselves as
1576 // exiting.
1577 }
1578 // no more external suspends are allowed at this point
1579 } else {
1580 // before_exit() has already posted JVMTI THREAD_END events
1581 }
1582
1583 // Notify waiters on thread object. This has to be done after exit() is called
1584 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1585 // group should have the destroyed bit set before waiters are notified).
1586 ensure_join(this);
1587 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1588
1589 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1590 // held by this thread must be released. A detach operation must only
1591 // get here if there are no Java frames on the stack. Therefore, any
1592 // owned monitors at this point MUST be JNI-acquired monitors which are
1593 // pre-inflated and in the monitor cache.
1594 //
1595 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1596 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1597 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1598 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1599 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1600 }
1601
1602 // These things needs to be done while we are still a Java Thread. Make sure that thread
1603 // is in a consistent state, in case GC happens
1604 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1605
1606 if (active_handles() != NULL) {
1607 JNIHandleBlock* block = active_handles();
1608 set_active_handles(NULL);
1609 JNIHandleBlock::release_block(block);
1610 }
1611
1612 if (free_handle_block() != NULL) {
1613 JNIHandleBlock* block = free_handle_block();
1614 set_free_handle_block(NULL);
1615 JNIHandleBlock::release_block(block);
1616 }
1617
1618 // These have to be removed while this is still a valid thread.
1619 remove_stack_guard_pages();
1620
1621 if (UseTLAB) {
1622 tlab().make_parsable(true); // retire TLAB
1623 }
1624
1625 if (jvmti_thread_state() != NULL) {
1626 JvmtiExport::cleanup_thread(this);
1627 }
1628
1629 #ifndef SERIALGC
1630 // We must flush G1-related buffers before removing a thread from
1631 // the list of active threads.
1632 if (UseG1GC) {
1633 flush_barrier_queues();
1634 }
1635 #endif
1636
1637 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1638 Threads::remove(this);
1639 }
1640
1641 #ifndef SERIALGC
1642 // Flush G1-related queues.
1643 void JavaThread::flush_barrier_queues() {
1644 satb_mark_queue().flush();
1645 dirty_card_queue().flush();
1646 }
1647 #endif
1648
1649 void JavaThread::cleanup_failed_attach_current_thread() {
1650 if (get_thread_profiler() != NULL) {
1651 get_thread_profiler()->disengage();
1652 ResourceMark rm;
1653 get_thread_profiler()->print(get_thread_name());
1654 }
1655
1656 if (active_handles() != NULL) {
1657 JNIHandleBlock* block = active_handles();
1658 set_active_handles(NULL);
1659 JNIHandleBlock::release_block(block);
1660 }
1661
1662 if (free_handle_block() != NULL) {
1663 JNIHandleBlock* block = free_handle_block();
1664 set_free_handle_block(NULL);
1665 JNIHandleBlock::release_block(block);
1666 }
1667
1668 // These have to be removed while this is still a valid thread.
1669 remove_stack_guard_pages();
1670
1671 if (UseTLAB) {
1672 tlab().make_parsable(true); // retire TLAB, if any
1673 }
1674
1675 #ifndef SERIALGC
1676 if (UseG1GC) {
1677 flush_barrier_queues();
1678 }
1679 #endif
1680
1681 Threads::remove(this);
1682 delete this;
1683 }
1684
1685
1686
1687
1688 JavaThread* JavaThread::active() {
1689 Thread* thread = ThreadLocalStorage::thread();
1690 assert(thread != NULL, "just checking");
1691 if (thread->is_Java_thread()) {
1692 return (JavaThread*) thread;
1693 } else {
1694 assert(thread->is_VM_thread(), "this must be a vm thread");
1695 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1696 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1697 assert(ret->is_Java_thread(), "must be a Java thread");
1698 return ret;
1699 }
1700 }
1701
1702 bool JavaThread::is_lock_owned(address adr) const {
1703 if (Thread::is_lock_owned(adr)) return true;
1704
1705 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1706 if (chunk->contains(adr)) return true;
1707 }
1708
1709 return false;
1710 }
1711
1712
1713 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1714 chunk->set_next(monitor_chunks());
1715 set_monitor_chunks(chunk);
1716 }
1717
1718 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1719 guarantee(monitor_chunks() != NULL, "must be non empty");
1720 if (monitor_chunks() == chunk) {
1721 set_monitor_chunks(chunk->next());
1722 } else {
1723 MonitorChunk* prev = monitor_chunks();
1724 while (prev->next() != chunk) prev = prev->next();
1725 prev->set_next(chunk->next());
1726 }
1727 }
1728
1729 // JVM support.
1730
1731 // Note: this function shouldn't block if it's called in
1732 // _thread_in_native_trans state (such as from
1733 // check_special_condition_for_native_trans()).
1734 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
1735
1736 if (has_last_Java_frame() && has_async_condition()) {
1737 // If we are at a polling page safepoint (not a poll return)
1738 // then we must defer async exception because live registers
1739 // will be clobbered by the exception path. Poll return is
1740 // ok because the call we a returning from already collides
1741 // with exception handling registers and so there is no issue.
1742 // (The exception handling path kills call result registers but
1743 // this is ok since the exception kills the result anyway).
1744
1745 if (is_at_poll_safepoint()) {
1746 // if the code we are returning to has deoptimized we must defer
1747 // the exception otherwise live registers get clobbered on the
1748 // exception path before deoptimization is able to retrieve them.
1749 //
1750 RegisterMap map(this, false);
1751 frame caller_fr = last_frame().sender(&map);
1752 assert(caller_fr.is_compiled_frame(), "what?");
1753 if (caller_fr.is_deoptimized_frame()) {
1754 if (TraceExceptions) {
1755 ResourceMark rm;
1756 tty->print_cr("deferred async exception at compiled safepoint");
1757 }
1758 return;
1759 }
1760 }
1761 }
1762
1763 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
1764 if (condition == _no_async_condition) {
1765 // Conditions have changed since has_special_runtime_exit_condition()
1766 // was called:
1767 // - if we were here only because of an external suspend request,
1768 // then that was taken care of above (or cancelled) so we are done
1769 // - if we were here because of another async request, then it has
1770 // been cleared between the has_special_runtime_exit_condition()
1771 // and now so again we are done
1772 return;
1773 }
1774
1775 // Check for pending async. exception
1776 if (_pending_async_exception != NULL) {
1777 // Only overwrite an already pending exception, if it is not a threadDeath.
1778 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
1779
1780 // We cannot call Exceptions::_throw(...) here because we cannot block
1781 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1782
1783 if (TraceExceptions) {
1784 ResourceMark rm;
1785 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
1786 if (has_last_Java_frame() ) {
1787 frame f = last_frame();
1788 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
1789 }
1790 tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1791 }
1792 _pending_async_exception = NULL;
1793 clear_has_async_exception();
1794 }
1795 }
1796
1797 if (check_unsafe_error &&
1798 condition == _async_unsafe_access_error && !has_pending_exception()) {
1799 condition = _no_async_condition; // done
1800 switch (thread_state()) {
1801 case _thread_in_vm:
1802 {
1803 JavaThread* THREAD = this;
1804 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1805 }
1806 case _thread_in_native:
1807 {
1808 ThreadInVMfromNative tiv(this);
1809 JavaThread* THREAD = this;
1810 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1811 }
1812 case _thread_in_Java:
1813 {
1814 ThreadInVMfromJava tiv(this);
1815 JavaThread* THREAD = this;
1816 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1817 }
1818 default:
1819 ShouldNotReachHere();
1820 }
1821 }
1822
1823 assert(condition == _no_async_condition || has_pending_exception() ||
1824 (!check_unsafe_error && condition == _async_unsafe_access_error),
1825 "must have handled the async condition, if no exception");
1826 }
1827
1828 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1829 //
1830 // Check for pending external suspend. Internal suspend requests do
1831 // not use handle_special_runtime_exit_condition().
1832 // If JNIEnv proxies are allowed, don't self-suspend if the target
1833 // thread is not the current thread. In older versions of jdbx, jdbx
1834 // threads could call into the VM with another thread's JNIEnv so we
1835 // can be here operating on behalf of a suspended thread (4432884).
1836 bool do_self_suspend = is_external_suspend_with_lock();
1837 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
1838 //
1839 // Because thread is external suspended the safepoint code will count
1840 // thread as at a safepoint. This can be odd because we can be here
1841 // as _thread_in_Java which would normally transition to _thread_blocked
1842 // at a safepoint. We would like to mark the thread as _thread_blocked
1843 // before calling java_suspend_self like all other callers of it but
1844 // we must then observe proper safepoint protocol. (We can't leave
1845 // _thread_blocked with a safepoint in progress). However we can be
1846 // here as _thread_in_native_trans so we can't use a normal transition
1847 // constructor/destructor pair because they assert on that type of
1848 // transition. We could do something like:
1849 //
1850 // JavaThreadState state = thread_state();
1851 // set_thread_state(_thread_in_vm);
1852 // {
1853 // ThreadBlockInVM tbivm(this);
1854 // java_suspend_self()
1855 // }
1856 // set_thread_state(_thread_in_vm_trans);
1857 // if (safepoint) block;
1858 // set_thread_state(state);
1859 //
1860 // but that is pretty messy. Instead we just go with the way the
1861 // code has worked before and note that this is the only path to
1862 // java_suspend_self that doesn't put the thread in _thread_blocked
1863 // mode.
1864
1865 frame_anchor()->make_walkable(this);
1866 java_suspend_self();
1867
1868 // We might be here for reasons in addition to the self-suspend request
1869 // so check for other async requests.
1870 }
1871
1872 if (check_asyncs) {
1873 check_and_handle_async_exceptions();
1874 }
1875 }
1876
1877 void JavaThread::send_thread_stop(oop java_throwable) {
1878 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
1879 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
1880 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1881
1882 // Do not throw asynchronous exceptions against the compiler thread
1883 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1884 if (is_Compiler_thread()) return;
1885
1886 // This is a change from JDK 1.1, but JDK 1.2 will also do it:
1887 if (java_throwable->is_a(SystemDictionary::ThreadDeath_klass())) {
1888 java_lang_Thread::set_stillborn(threadObj());
1889 }
1890
1891 {
1892 // Actually throw the Throwable against the target Thread - however
1893 // only if there is no thread death exception installed already.
1894 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
1895 // If the topmost frame is a runtime stub, then we are calling into
1896 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1897 // must deoptimize the caller before continuing, as the compiled exception handler table
1898 // may not be valid
1899 if (has_last_Java_frame()) {
1900 frame f = last_frame();
1901 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1902 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
1903 RegisterMap reg_map(this, UseBiasedLocking);
1904 frame compiled_frame = f.sender(®_map);
1905 if (compiled_frame.can_be_deoptimized()) {
1906 Deoptimization::deoptimize(this, compiled_frame, ®_map);
1907 }
1908 }
1909 }
1910
1911 // Set async. pending exception in thread.
1912 set_pending_async_exception(java_throwable);
1913
1914 if (TraceExceptions) {
1915 ResourceMark rm;
1916 tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1917 }
1918 // for AbortVMOnException flag
1919 NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name()));
1920 }
1921 }
1922
1923
1924 // Interrupt thread so it will wake up from a potential wait()
1925 Thread::interrupt(this);
1926 }
1927
1928 // External suspension mechanism.
1929 //
1930 // Tell the VM to suspend a thread when ever it knows that it does not hold on
1931 // to any VM_locks and it is at a transition
1932 // Self-suspension will happen on the transition out of the vm.
1933 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
1934 //
1935 // Guarantees on return:
1936 // + Target thread will not execute any new bytecode (that's why we need to
1937 // force a safepoint)
1938 // + Target thread will not enter any new monitors
1939 //
1940 void JavaThread::java_suspend() {
1941 { MutexLocker mu(Threads_lock);
1942 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
1943 return;
1944 }
1945 }
1946
1947 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1948 if (!is_external_suspend()) {
1949 // a racing resume has cancelled us; bail out now
1950 return;
1951 }
1952
1953 // suspend is done
1954 uint32_t debug_bits = 0;
1955 // Warning: is_ext_suspend_completed() may temporarily drop the
1956 // SR_lock to allow the thread to reach a stable thread state if
1957 // it is currently in a transient thread state.
1958 if (is_ext_suspend_completed(false /* !called_by_wait */,
1959 SuspendRetryDelay, &debug_bits) ) {
1960 return;
1961 }
1962 }
1963
1964 VM_ForceSafepoint vm_suspend;
1965 VMThread::execute(&vm_suspend);
1966 }
1967
1968 // Part II of external suspension.
1969 // A JavaThread self suspends when it detects a pending external suspend
1970 // request. This is usually on transitions. It is also done in places
1971 // where continuing to the next transition would surprise the caller,
1972 // e.g., monitor entry.
1973 //
1974 // Returns the number of times that the thread self-suspended.
1975 //
1976 // Note: DO NOT call java_suspend_self() when you just want to block current
1977 // thread. java_suspend_self() is the second stage of cooperative
1978 // suspension for external suspend requests and should only be used
1979 // to complete an external suspend request.
1980 //
1981 int JavaThread::java_suspend_self() {
1982 int ret = 0;
1983
1984 // we are in the process of exiting so don't suspend
1985 if (is_exiting()) {
1986 clear_external_suspend();
1987 return ret;
1988 }
1989
1990 assert(_anchor.walkable() ||
1991 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
1992 "must have walkable stack");
1993
1994 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1995
1996 assert(!this->is_ext_suspended(),
1997 "a thread trying to self-suspend should not already be suspended");
1998
1999 if (this->is_suspend_equivalent()) {
2000 // If we are self-suspending as a result of the lifting of a
2001 // suspend equivalent condition, then the suspend_equivalent
2002 // flag is not cleared until we set the ext_suspended flag so
2003 // that wait_for_ext_suspend_completion() returns consistent
2004 // results.
2005 this->clear_suspend_equivalent();
2006 }
2007
2008 // A racing resume may have cancelled us before we grabbed SR_lock
2009 // above. Or another external suspend request could be waiting for us
2010 // by the time we return from SR_lock()->wait(). The thread
2011 // that requested the suspension may already be trying to walk our
2012 // stack and if we return now, we can change the stack out from under
2013 // it. This would be a "bad thing (TM)" and cause the stack walker
2014 // to crash. We stay self-suspended until there are no more pending
2015 // external suspend requests.
2016 while (is_external_suspend()) {
2017 ret++;
2018 this->set_ext_suspended();
2019
2020 // _ext_suspended flag is cleared by java_resume()
2021 while (is_ext_suspended()) {
2022 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2023 }
2024 }
2025
2026 return ret;
2027 }
2028
2029 #ifdef ASSERT
2030 // verify the JavaThread has not yet been published in the Threads::list, and
2031 // hence doesn't need protection from concurrent access at this stage
2032 void JavaThread::verify_not_published() {
2033 if (!Threads_lock->owned_by_self()) {
2034 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2035 assert( !Threads::includes(this),
2036 "java thread shouldn't have been published yet!");
2037 }
2038 else {
2039 assert( !Threads::includes(this),
2040 "java thread shouldn't have been published yet!");
2041 }
2042 }
2043 #endif
2044
2045 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2046 // progress or when _suspend_flags is non-zero.
2047 // Current thread needs to self-suspend if there is a suspend request and/or
2048 // block if a safepoint is in progress.
2049 // Async exception ISN'T checked.
2050 // Note only the ThreadInVMfromNative transition can call this function
2051 // directly and when thread state is _thread_in_native_trans
2052 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2053 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2054
2055 JavaThread *curJT = JavaThread::current();
2056 bool do_self_suspend = thread->is_external_suspend();
2057
2058 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2059
2060 // If JNIEnv proxies are allowed, don't self-suspend if the target
2061 // thread is not the current thread. In older versions of jdbx, jdbx
2062 // threads could call into the VM with another thread's JNIEnv so we
2063 // can be here operating on behalf of a suspended thread (4432884).
2064 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2065 JavaThreadState state = thread->thread_state();
2066
2067 // We mark this thread_blocked state as a suspend-equivalent so
2068 // that a caller to is_ext_suspend_completed() won't be confused.
2069 // The suspend-equivalent state is cleared by java_suspend_self().
2070 thread->set_suspend_equivalent();
2071
2072 // If the safepoint code sees the _thread_in_native_trans state, it will
2073 // wait until the thread changes to other thread state. There is no
2074 // guarantee on how soon we can obtain the SR_lock and complete the
2075 // self-suspend request. It would be a bad idea to let safepoint wait for
2076 // too long. Temporarily change the state to _thread_blocked to
2077 // let the VM thread know that this thread is ready for GC. The problem
2078 // of changing thread state is that safepoint could happen just after
2079 // java_suspend_self() returns after being resumed, and VM thread will
2080 // see the _thread_blocked state. We must check for safepoint
2081 // after restoring the state and make sure we won't leave while a safepoint
2082 // is in progress.
2083 thread->set_thread_state(_thread_blocked);
2084 thread->java_suspend_self();
2085 thread->set_thread_state(state);
2086 // Make sure new state is seen by VM thread
2087 if (os::is_MP()) {
2088 if (UseMembar) {
2089 // Force a fence between the write above and read below
2090 OrderAccess::fence();
2091 } else {
2092 // Must use this rather than serialization page in particular on Windows
2093 InterfaceSupport::serialize_memory(thread);
2094 }
2095 }
2096 }
2097
2098 if (SafepointSynchronize::do_call_back()) {
2099 // If we are safepointing, then block the caller which may not be
2100 // the same as the target thread (see above).
2101 SafepointSynchronize::block(curJT);
2102 }
2103
2104 if (thread->is_deopt_suspend()) {
2105 thread->clear_deopt_suspend();
2106 RegisterMap map(thread, false);
2107 frame f = thread->last_frame();
2108 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2109 f = f.sender(&map);
2110 }
2111 if (f.id() == thread->must_deopt_id()) {
2112 thread->clear_must_deopt_id();
2113 f.deoptimize(thread);
2114 } else {
2115 fatal("missed deoptimization!");
2116 }
2117 }
2118 }
2119
2120 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2121 // progress or when _suspend_flags is non-zero.
2122 // Current thread needs to self-suspend if there is a suspend request and/or
2123 // block if a safepoint is in progress.
2124 // Also check for pending async exception (not including unsafe access error).
2125 // Note only the native==>VM/Java barriers can call this function and when
2126 // thread state is _thread_in_native_trans.
2127 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2128 check_safepoint_and_suspend_for_native_trans(thread);
2129
2130 if (thread->has_async_exception()) {
2131 // We are in _thread_in_native_trans state, don't handle unsafe
2132 // access error since that may block.
2133 thread->check_and_handle_async_exceptions(false);
2134 }
2135 }
2136
2137 // We need to guarantee the Threads_lock here, since resumes are not
2138 // allowed during safepoint synchronization
2139 // Can only resume from an external suspension
2140 void JavaThread::java_resume() {
2141 assert_locked_or_safepoint(Threads_lock);
2142
2143 // Sanity check: thread is gone, has started exiting or the thread
2144 // was not externally suspended.
2145 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2146 return;
2147 }
2148
2149 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2150
2151 clear_external_suspend();
2152
2153 if (is_ext_suspended()) {
2154 clear_ext_suspended();
2155 SR_lock()->notify_all();
2156 }
2157 }
2158
2159 void JavaThread::create_stack_guard_pages() {
2160 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2161 address low_addr = stack_base() - stack_size();
2162 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2163
2164 int allocate = os::allocate_stack_guard_pages();
2165 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2166
2167 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
2168 warning("Attempt to allocate stack guard pages failed.");
2169 return;
2170 }
2171
2172 if (os::guard_memory((char *) low_addr, len)) {
2173 _stack_guard_state = stack_guard_enabled;
2174 } else {
2175 warning("Attempt to protect stack guard pages failed.");
2176 if (os::uncommit_memory((char *) low_addr, len)) {
2177 warning("Attempt to deallocate stack guard pages failed.");
2178 }
2179 }
2180 }
2181
2182 void JavaThread::remove_stack_guard_pages() {
2183 if (_stack_guard_state == stack_guard_unused) return;
2184 address low_addr = stack_base() - stack_size();
2185 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2186
2187 if (os::allocate_stack_guard_pages()) {
2188 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2189 _stack_guard_state = stack_guard_unused;
2190 } else {
2191 warning("Attempt to deallocate stack guard pages failed.");
2192 }
2193 } else {
2194 if (_stack_guard_state == stack_guard_unused) return;
2195 if (os::unguard_memory((char *) low_addr, len)) {
2196 _stack_guard_state = stack_guard_unused;
2197 } else {
2198 warning("Attempt to unprotect stack guard pages failed.");
2199 }
2200 }
2201 }
2202
2203 void JavaThread::enable_stack_yellow_zone() {
2204 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2205 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2206
2207 // The base notation is from the stacks point of view, growing downward.
2208 // We need to adjust it to work correctly with guard_memory()
2209 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2210
2211 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2212 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2213
2214 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2215 _stack_guard_state = stack_guard_enabled;
2216 } else {
2217 warning("Attempt to guard stack yellow zone failed.");
2218 }
2219 enable_register_stack_guard();
2220 }
2221
2222 void JavaThread::disable_stack_yellow_zone() {
2223 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2224 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2225
2226 // Simply return if called for a thread that does not use guard pages.
2227 if (_stack_guard_state == stack_guard_unused) return;
2228
2229 // The base notation is from the stacks point of view, growing downward.
2230 // We need to adjust it to work correctly with guard_memory()
2231 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2232
2233 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2234 _stack_guard_state = stack_guard_yellow_disabled;
2235 } else {
2236 warning("Attempt to unguard stack yellow zone failed.");
2237 }
2238 disable_register_stack_guard();
2239 }
2240
2241 void JavaThread::enable_stack_red_zone() {
2242 // The base notation is from the stacks point of view, growing downward.
2243 // We need to adjust it to work correctly with guard_memory()
2244 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2245 address base = stack_red_zone_base() - stack_red_zone_size();
2246
2247 guarantee(base < stack_base(),"Error calculating stack red zone");
2248 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2249
2250 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2251 warning("Attempt to guard stack red zone failed.");
2252 }
2253 }
2254
2255 void JavaThread::disable_stack_red_zone() {
2256 // The base notation is from the stacks point of view, growing downward.
2257 // We need to adjust it to work correctly with guard_memory()
2258 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2259 address base = stack_red_zone_base() - stack_red_zone_size();
2260 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2261 warning("Attempt to unguard stack red zone failed.");
2262 }
2263 }
2264
2265 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2266 // ignore is there is no stack
2267 if (!has_last_Java_frame()) return;
2268 // traverse the stack frames. Starts from top frame.
2269 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2270 frame* fr = fst.current();
2271 f(fr, fst.register_map());
2272 }
2273 }
2274
2275
2276 #ifndef PRODUCT
2277 // Deoptimization
2278 // Function for testing deoptimization
2279 void JavaThread::deoptimize() {
2280 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2281 StackFrameStream fst(this, UseBiasedLocking);
2282 bool deopt = false; // Dump stack only if a deopt actually happens.
2283 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2284 // Iterate over all frames in the thread and deoptimize
2285 for(; !fst.is_done(); fst.next()) {
2286 if(fst.current()->can_be_deoptimized()) {
2287
2288 if (only_at) {
2289 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2290 // consists of comma or carriage return separated numbers so
2291 // search for the current bci in that string.
2292 address pc = fst.current()->pc();
2293 nmethod* nm = (nmethod*) fst.current()->cb();
2294 ScopeDesc* sd = nm->scope_desc_at( pc);
2295 char buffer[8];
2296 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2297 size_t len = strlen(buffer);
2298 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2299 while (found != NULL) {
2300 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2301 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2302 // Check that the bci found is bracketed by terminators.
2303 break;
2304 }
2305 found = strstr(found + 1, buffer);
2306 }
2307 if (!found) {
2308 continue;
2309 }
2310 }
2311
2312 if (DebugDeoptimization && !deopt) {
2313 deopt = true; // One-time only print before deopt
2314 tty->print_cr("[BEFORE Deoptimization]");
2315 trace_frames();
2316 trace_stack();
2317 }
2318 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2319 }
2320 }
2321
2322 if (DebugDeoptimization && deopt) {
2323 tty->print_cr("[AFTER Deoptimization]");
2324 trace_frames();
2325 }
2326 }
2327
2328
2329 // Make zombies
2330 void JavaThread::make_zombies() {
2331 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2332 if (fst.current()->can_be_deoptimized()) {
2333 // it is a Java nmethod
2334 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2335 nm->make_not_entrant();
2336 }
2337 }
2338 }
2339 #endif // PRODUCT
2340
2341
2342 void JavaThread::deoptimized_wrt_marked_nmethods() {
2343 if (!has_last_Java_frame()) return;
2344 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2345 StackFrameStream fst(this, UseBiasedLocking);
2346 for(; !fst.is_done(); fst.next()) {
2347 if (fst.current()->should_be_deoptimized()) {
2348 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2349 }
2350 }
2351 }
2352
2353
2354 // GC support
2355 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2356
2357 void JavaThread::gc_epilogue() {
2358 frames_do(frame_gc_epilogue);
2359 }
2360
2361
2362 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2363
2364 void JavaThread::gc_prologue() {
2365 frames_do(frame_gc_prologue);
2366 }
2367
2368 // If the caller is a NamedThread, then remember, in the current scope,
2369 // the given JavaThread in its _processed_thread field.
2370 class RememberProcessedThread: public StackObj {
2371 NamedThread* _cur_thr;
2372 public:
2373 RememberProcessedThread(JavaThread* jthr) {
2374 Thread* thread = Thread::current();
2375 if (thread->is_Named_thread()) {
2376 _cur_thr = (NamedThread *)thread;
2377 _cur_thr->set_processed_thread(jthr);
2378 } else {
2379 _cur_thr = NULL;
2380 }
2381 }
2382
2383 ~RememberProcessedThread() {
2384 if (_cur_thr) {
2385 _cur_thr->set_processed_thread(NULL);
2386 }
2387 }
2388 };
2389
2390 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2391 // Verify that the deferred card marks have been flushed.
2392 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2393
2394 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2395 // since there may be more than one thread using each ThreadProfiler.
2396
2397 // Traverse the GCHandles
2398 Thread::oops_do(f, cf);
2399
2400 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2401 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2402
2403 if (has_last_Java_frame()) {
2404 // Record JavaThread to GC thread
2405 RememberProcessedThread rpt(this);
2406
2407 // Traverse the privileged stack
2408 if (_privileged_stack_top != NULL) {
2409 _privileged_stack_top->oops_do(f);
2410 }
2411
2412 // traverse the registered growable array
2413 if (_array_for_gc != NULL) {
2414 for (int index = 0; index < _array_for_gc->length(); index++) {
2415 f->do_oop(_array_for_gc->adr_at(index));
2416 }
2417 }
2418
2419 // Traverse the monitor chunks
2420 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2421 chunk->oops_do(f);
2422 }
2423
2424 // Traverse the execution stack
2425 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2426 fst.current()->oops_do(f, cf, fst.register_map());
2427 }
2428 }
2429
2430 // callee_target is never live across a gc point so NULL it here should
2431 // it still contain a methdOop.
2432
2433 set_callee_target(NULL);
2434
2435 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2436 // If we have deferred set_locals there might be oops waiting to be
2437 // written
2438 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2439 if (list != NULL) {
2440 for (int i = 0; i < list->length(); i++) {
2441 list->at(i)->oops_do(f);
2442 }
2443 }
2444
2445 // Traverse instance variables at the end since the GC may be moving things
2446 // around using this function
2447 f->do_oop((oop*) &_threadObj);
2448 f->do_oop((oop*) &_vm_result);
2449 f->do_oop((oop*) &_vm_result_2);
2450 f->do_oop((oop*) &_exception_oop);
2451 f->do_oop((oop*) &_pending_async_exception);
2452
2453 if (jvmti_thread_state() != NULL) {
2454 jvmti_thread_state()->oops_do(f);
2455 }
2456 }
2457
2458 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2459 Thread::nmethods_do(cf); // (super method is a no-op)
2460
2461 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2462 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2463
2464 if (has_last_Java_frame()) {
2465 // Traverse the execution stack
2466 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2467 fst.current()->nmethods_do(cf);
2468 }
2469 }
2470 }
2471
2472 // Printing
2473 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2474 switch (_thread_state) {
2475 case _thread_uninitialized: return "_thread_uninitialized";
2476 case _thread_new: return "_thread_new";
2477 case _thread_new_trans: return "_thread_new_trans";
2478 case _thread_in_native: return "_thread_in_native";
2479 case _thread_in_native_trans: return "_thread_in_native_trans";
2480 case _thread_in_vm: return "_thread_in_vm";
2481 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2482 case _thread_in_Java: return "_thread_in_Java";
2483 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2484 case _thread_blocked: return "_thread_blocked";
2485 case _thread_blocked_trans: return "_thread_blocked_trans";
2486 default: return "unknown thread state";
2487 }
2488 }
2489
2490 #ifndef PRODUCT
2491 void JavaThread::print_thread_state_on(outputStream *st) const {
2492 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2493 };
2494 void JavaThread::print_thread_state() const {
2495 print_thread_state_on(tty);
2496 };
2497 #endif // PRODUCT
2498
2499 // Called by Threads::print() for VM_PrintThreads operation
2500 void JavaThread::print_on(outputStream *st) const {
2501 st->print("\"%s\" ", get_thread_name());
2502 oop thread_oop = threadObj();
2503 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2504 Thread::print_on(st);
2505 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2506 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2507 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2508 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2509 }
2510 #ifndef PRODUCT
2511 print_thread_state_on(st);
2512 _safepoint_state->print_on(st);
2513 #endif // PRODUCT
2514 }
2515
2516 // Called by fatal error handler. The difference between this and
2517 // JavaThread::print() is that we can't grab lock or allocate memory.
2518 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2519 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2520 oop thread_obj = threadObj();
2521 if (thread_obj != NULL) {
2522 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2523 }
2524 st->print(" [");
2525 st->print("%s", _get_thread_state_name(_thread_state));
2526 if (osthread()) {
2527 st->print(", id=%d", osthread()->thread_id());
2528 }
2529 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2530 _stack_base - _stack_size, _stack_base);
2531 st->print("]");
2532 return;
2533 }
2534
2535 // Verification
2536
2537 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2538
2539 void JavaThread::verify() {
2540 // Verify oops in the thread.
2541 oops_do(&VerifyOopClosure::verify_oop, NULL);
2542
2543 // Verify the stack frames.
2544 frames_do(frame_verify);
2545 }
2546
2547 // CR 6300358 (sub-CR 2137150)
2548 // Most callers of this method assume that it can't return NULL but a
2549 // thread may not have a name whilst it is in the process of attaching to
2550 // the VM - see CR 6412693, and there are places where a JavaThread can be
2551 // seen prior to having it's threadObj set (eg JNI attaching threads and
2552 // if vm exit occurs during initialization). These cases can all be accounted
2553 // for such that this method never returns NULL.
2554 const char* JavaThread::get_thread_name() const {
2555 #ifdef ASSERT
2556 // early safepoints can hit while current thread does not yet have TLS
2557 if (!SafepointSynchronize::is_at_safepoint()) {
2558 Thread *cur = Thread::current();
2559 if (!(cur->is_Java_thread() && cur == this)) {
2560 // Current JavaThreads are allowed to get their own name without
2561 // the Threads_lock.
2562 assert_locked_or_safepoint(Threads_lock);
2563 }
2564 }
2565 #endif // ASSERT
2566 return get_thread_name_string();
2567 }
2568
2569 // Returns a non-NULL representation of this thread's name, or a suitable
2570 // descriptive string if there is no set name
2571 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2572 const char* name_str;
2573 oop thread_obj = threadObj();
2574 if (thread_obj != NULL) {
2575 typeArrayOop name = java_lang_Thread::name(thread_obj);
2576 if (name != NULL) {
2577 if (buf == NULL) {
2578 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2579 }
2580 else {
2581 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2582 }
2583 }
2584 else if (is_attaching()) { // workaround for 6412693 - see 6404306
2585 name_str = "<no-name - thread is attaching>";
2586 }
2587 else {
2588 name_str = Thread::name();
2589 }
2590 }
2591 else {
2592 name_str = Thread::name();
2593 }
2594 assert(name_str != NULL, "unexpected NULL thread name");
2595 return name_str;
2596 }
2597
2598
2599 const char* JavaThread::get_threadgroup_name() const {
2600 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2601 oop thread_obj = threadObj();
2602 if (thread_obj != NULL) {
2603 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2604 if (thread_group != NULL) {
2605 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2606 // ThreadGroup.name can be null
2607 if (name != NULL) {
2608 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2609 return str;
2610 }
2611 }
2612 }
2613 return NULL;
2614 }
2615
2616 const char* JavaThread::get_parent_name() const {
2617 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2618 oop thread_obj = threadObj();
2619 if (thread_obj != NULL) {
2620 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2621 if (thread_group != NULL) {
2622 oop parent = java_lang_ThreadGroup::parent(thread_group);
2623 if (parent != NULL) {
2624 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2625 // ThreadGroup.name can be null
2626 if (name != NULL) {
2627 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2628 return str;
2629 }
2630 }
2631 }
2632 }
2633 return NULL;
2634 }
2635
2636 ThreadPriority JavaThread::java_priority() const {
2637 oop thr_oop = threadObj();
2638 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2639 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2640 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2641 return priority;
2642 }
2643
2644 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2645
2646 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2647 // Link Java Thread object <-> C++ Thread
2648
2649 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2650 // and put it into a new Handle. The Handle "thread_oop" can then
2651 // be used to pass the C++ thread object to other methods.
2652
2653 // Set the Java level thread object (jthread) field of the
2654 // new thread (a JavaThread *) to C++ thread object using the
2655 // "thread_oop" handle.
2656
2657 // Set the thread field (a JavaThread *) of the
2658 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2659
2660 Handle thread_oop(Thread::current(),
2661 JNIHandles::resolve_non_null(jni_thread));
2662 assert(instanceKlass::cast(thread_oop->klass())->is_linked(),
2663 "must be initialized");
2664 set_threadObj(thread_oop());
2665 java_lang_Thread::set_thread(thread_oop(), this);
2666
2667 if (prio == NoPriority) {
2668 prio = java_lang_Thread::priority(thread_oop());
2669 assert(prio != NoPriority, "A valid priority should be present");
2670 }
2671
2672 // Push the Java priority down to the native thread; needs Threads_lock
2673 Thread::set_priority(this, prio);
2674
2675 // Add the new thread to the Threads list and set it in motion.
2676 // We must have threads lock in order to call Threads::add.
2677 // It is crucial that we do not block before the thread is
2678 // added to the Threads list for if a GC happens, then the java_thread oop
2679 // will not be visited by GC.
2680 Threads::add(this);
2681 }
2682
2683 oop JavaThread::current_park_blocker() {
2684 // Support for JSR-166 locks
2685 oop thread_oop = threadObj();
2686 if (thread_oop != NULL &&
2687 JDK_Version::current().supports_thread_park_blocker()) {
2688 return java_lang_Thread::park_blocker(thread_oop);
2689 }
2690 return NULL;
2691 }
2692
2693
2694 void JavaThread::print_stack_on(outputStream* st) {
2695 if (!has_last_Java_frame()) return;
2696 ResourceMark rm;
2697 HandleMark hm;
2698
2699 RegisterMap reg_map(this);
2700 vframe* start_vf = last_java_vframe(®_map);
2701 int count = 0;
2702 for (vframe* f = start_vf; f; f = f->sender() ) {
2703 if (f->is_java_frame()) {
2704 javaVFrame* jvf = javaVFrame::cast(f);
2705 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2706
2707 // Print out lock information
2708 if (JavaMonitorsInStackTrace) {
2709 jvf->print_lock_info_on(st, count);
2710 }
2711 } else {
2712 // Ignore non-Java frames
2713 }
2714
2715 // Bail-out case for too deep stacks
2716 count++;
2717 if (MaxJavaStackTraceDepth == count) return;
2718 }
2719 }
2720
2721
2722 // JVMTI PopFrame support
2723 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2724 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2725 if (in_bytes(size_in_bytes) != 0) {
2726 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes));
2727 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2728 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2729 }
2730 }
2731
2732 void* JavaThread::popframe_preserved_args() {
2733 return _popframe_preserved_args;
2734 }
2735
2736 ByteSize JavaThread::popframe_preserved_args_size() {
2737 return in_ByteSize(_popframe_preserved_args_size);
2738 }
2739
2740 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2741 int sz = in_bytes(popframe_preserved_args_size());
2742 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2743 return in_WordSize(sz / wordSize);
2744 }
2745
2746 void JavaThread::popframe_free_preserved_args() {
2747 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2748 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args);
2749 _popframe_preserved_args = NULL;
2750 _popframe_preserved_args_size = 0;
2751 }
2752
2753 #ifndef PRODUCT
2754
2755 void JavaThread::trace_frames() {
2756 tty->print_cr("[Describe stack]");
2757 int frame_no = 1;
2758 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2759 tty->print(" %d. ", frame_no++);
2760 fst.current()->print_value_on(tty,this);
2761 tty->cr();
2762 }
2763 }
2764
2765
2766 void JavaThread::trace_stack_from(vframe* start_vf) {
2767 ResourceMark rm;
2768 int vframe_no = 1;
2769 for (vframe* f = start_vf; f; f = f->sender() ) {
2770 if (f->is_java_frame()) {
2771 javaVFrame::cast(f)->print_activation(vframe_no++);
2772 } else {
2773 f->print();
2774 }
2775 if (vframe_no > StackPrintLimit) {
2776 tty->print_cr("...<more frames>...");
2777 return;
2778 }
2779 }
2780 }
2781
2782
2783 void JavaThread::trace_stack() {
2784 if (!has_last_Java_frame()) return;
2785 ResourceMark rm;
2786 HandleMark hm;
2787 RegisterMap reg_map(this);
2788 trace_stack_from(last_java_vframe(®_map));
2789 }
2790
2791
2792 #endif // PRODUCT
2793
2794
2795 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2796 assert(reg_map != NULL, "a map must be given");
2797 frame f = last_frame();
2798 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
2799 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2800 }
2801 return NULL;
2802 }
2803
2804
2805 klassOop JavaThread::security_get_caller_class(int depth) {
2806 vframeStream vfst(this);
2807 vfst.security_get_caller_frame(depth);
2808 if (!vfst.at_end()) {
2809 return vfst.method()->method_holder();
2810 }
2811 return NULL;
2812 }
2813
2814 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
2815 assert(thread->is_Compiler_thread(), "must be compiler thread");
2816 CompileBroker::compiler_thread_loop();
2817 }
2818
2819 // Create a CompilerThread
2820 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
2821 : JavaThread(&compiler_thread_entry) {
2822 _env = NULL;
2823 _log = NULL;
2824 _task = NULL;
2825 _queue = queue;
2826 _counters = counters;
2827 _buffer_blob = NULL;
2828
2829 #ifndef PRODUCT
2830 _ideal_graph_printer = NULL;
2831 #endif
2832 }
2833
2834
2835 // ======= Threads ========
2836
2837 // The Threads class links together all active threads, and provides
2838 // operations over all threads. It is protected by its own Mutex
2839 // lock, which is also used in other contexts to protect thread
2840 // operations from having the thread being operated on from exiting
2841 // and going away unexpectedly (e.g., safepoint synchronization)
2842
2843 JavaThread* Threads::_thread_list = NULL;
2844 int Threads::_number_of_threads = 0;
2845 int Threads::_number_of_non_daemon_threads = 0;
2846 int Threads::_return_code = 0;
2847 size_t JavaThread::_stack_size_at_create = 0;
2848
2849 // All JavaThreads
2850 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
2851
2852 void os_stream();
2853
2854 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
2855 void Threads::threads_do(ThreadClosure* tc) {
2856 assert_locked_or_safepoint(Threads_lock);
2857 // ALL_JAVA_THREADS iterates through all JavaThreads
2858 ALL_JAVA_THREADS(p) {
2859 tc->do_thread(p);
2860 }
2861 // Someday we could have a table or list of all non-JavaThreads.
2862 // For now, just manually iterate through them.
2863 tc->do_thread(VMThread::vm_thread());
2864 Universe::heap()->gc_threads_do(tc);
2865 WatcherThread *wt = WatcherThread::watcher_thread();
2866 // Strictly speaking, the following NULL check isn't sufficient to make sure
2867 // the data for WatcherThread is still valid upon being examined. However,
2868 // considering that WatchThread terminates when the VM is on the way to
2869 // exit at safepoint, the chance of the above is extremely small. The right
2870 // way to prevent termination of WatcherThread would be to acquire
2871 // Terminator_lock, but we can't do that without violating the lock rank
2872 // checking in some cases.
2873 if (wt != NULL)
2874 tc->do_thread(wt);
2875
2876 // If CompilerThreads ever become non-JavaThreads, add them here
2877 }
2878
2879 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2880
2881 extern void JDK_Version_init();
2882
2883 // Check version
2884 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2885
2886 // Initialize the output stream module
2887 ostream_init();
2888
2889 // Process java launcher properties.
2890 Arguments::process_sun_java_launcher_properties(args);
2891
2892 // Initialize the os module before using TLS
2893 os::init();
2894
2895 // Initialize system properties.
2896 Arguments::init_system_properties();
2897
2898 // So that JDK version can be used as a discrimintor when parsing arguments
2899 JDK_Version_init();
2900
2901 // Update/Initialize System properties after JDK version number is known
2902 Arguments::init_version_specific_system_properties();
2903
2904 // Parse arguments
2905 jint parse_result = Arguments::parse(args);
2906 if (parse_result != JNI_OK) return parse_result;
2907
2908 if (PauseAtStartup) {
2909 os::pause();
2910 }
2911
2912 HS_DTRACE_PROBE(hotspot, vm__init__begin);
2913
2914 // Record VM creation timing statistics
2915 TraceVmCreationTime create_vm_timer;
2916 create_vm_timer.start();
2917
2918 // Timing (must come after argument parsing)
2919 TraceTime timer("Create VM", TraceStartupTime);
2920
2921 // Initialize the os module after parsing the args
2922 jint os_init_2_result = os::init_2();
2923 if (os_init_2_result != JNI_OK) return os_init_2_result;
2924
2925 // Initialize output stream logging
2926 ostream_init_log();
2927
2928 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2929 // Must be before create_vm_init_agents()
2930 if (Arguments::init_libraries_at_startup()) {
2931 convert_vm_init_libraries_to_agents();
2932 }
2933
2934 // Launch -agentlib/-agentpath and converted -Xrun agents
2935 if (Arguments::init_agents_at_startup()) {
2936 create_vm_init_agents();
2937 }
2938
2939 // Initialize Threads state
2940 _thread_list = NULL;
2941 _number_of_threads = 0;
2942 _number_of_non_daemon_threads = 0;
2943
2944 // Initialize TLS
2945 ThreadLocalStorage::init();
2946
2947 // Initialize global data structures and create system classes in heap
2948 vm_init_globals();
2949
2950 // Attach the main thread to this os thread
2951 JavaThread* main_thread = new JavaThread();
2952 main_thread->set_thread_state(_thread_in_vm);
2953 // must do this before set_active_handles and initialize_thread_local_storage
2954 // Note: on solaris initialize_thread_local_storage() will (indirectly)
2955 // change the stack size recorded here to one based on the java thread
2956 // stacksize. This adjusted size is what is used to figure the placement
2957 // of the guard pages.
2958 main_thread->record_stack_base_and_size();
2959 main_thread->initialize_thread_local_storage();
2960
2961 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2962
2963 if (!main_thread->set_as_starting_thread()) {
2964 vm_shutdown_during_initialization(
2965 "Failed necessary internal allocation. Out of swap space");
2966 delete main_thread;
2967 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2968 return JNI_ENOMEM;
2969 }
2970
2971 // Enable guard page *after* os::create_main_thread(), otherwise it would
2972 // crash Linux VM, see notes in os_linux.cpp.
2973 main_thread->create_stack_guard_pages();
2974
2975 // Initialize Java-Leve synchronization subsystem
2976 ObjectSynchronizer::Initialize() ;
2977
2978 // Initialize global modules
2979 jint status = init_globals();
2980 if (status != JNI_OK) {
2981 delete main_thread;
2982 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2983 return status;
2984 }
2985
2986 // Should be done after the heap is fully created
2987 main_thread->cache_global_variables();
2988
2989 HandleMark hm;
2990
2991 { MutexLocker mu(Threads_lock);
2992 Threads::add(main_thread);
2993 }
2994
2995 // Any JVMTI raw monitors entered in onload will transition into
2996 // real raw monitor. VM is setup enough here for raw monitor enter.
2997 JvmtiExport::transition_pending_onload_raw_monitors();
2998
2999 if (VerifyBeforeGC &&
3000 Universe::heap()->total_collections() >= VerifyGCStartAt) {
3001 Universe::heap()->prepare_for_verify();
3002 Universe::verify(); // make sure we're starting with a clean slate
3003 }
3004
3005 // Create the VMThread
3006 { TraceTime timer("Start VMThread", TraceStartupTime);
3007 VMThread::create();
3008 Thread* vmthread = VMThread::vm_thread();
3009
3010 if (!os::create_thread(vmthread, os::vm_thread))
3011 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
3012
3013 // Wait for the VM thread to become ready, and VMThread::run to initialize
3014 // Monitors can have spurious returns, must always check another state flag
3015 {
3016 MutexLocker ml(Notify_lock);
3017 os::start_thread(vmthread);
3018 while (vmthread->active_handles() == NULL) {
3019 Notify_lock->wait();
3020 }
3021 }
3022 }
3023
3024 assert (Universe::is_fully_initialized(), "not initialized");
3025 EXCEPTION_MARK;
3026
3027 // At this point, the Universe is initialized, but we have not executed
3028 // any byte code. Now is a good time (the only time) to dump out the
3029 // internal state of the JVM for sharing.
3030
3031 if (DumpSharedSpaces) {
3032 Universe::heap()->preload_and_dump(CHECK_0);
3033 ShouldNotReachHere();
3034 }
3035
3036 // Always call even when there are not JVMTI environments yet, since environments
3037 // may be attached late and JVMTI must track phases of VM execution
3038 JvmtiExport::enter_start_phase();
3039
3040 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3041 JvmtiExport::post_vm_start();
3042
3043 {
3044 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3045
3046 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3047 create_vm_init_libraries();
3048 }
3049
3050 if (InitializeJavaLangString) {
3051 initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0);
3052 } else {
3053 warning("java.lang.String not initialized");
3054 }
3055
3056 if (AggressiveOpts) {
3057 {
3058 // Forcibly initialize java/util/HashMap and mutate the private
3059 // static final "frontCacheEnabled" field before we start creating instances
3060 #ifdef ASSERT
3061 klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3062 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
3063 #endif
3064 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3065 KlassHandle k = KlassHandle(THREAD, k_o);
3066 guarantee(k.not_null(), "Must find java/util/HashMap");
3067 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3068 ik->initialize(CHECK_0);
3069 fieldDescriptor fd;
3070 // Possible we might not find this field; if so, don't break
3071 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3072 k()->bool_field_put(fd.offset(), true);
3073 }
3074 }
3075
3076 if (UseStringCache) {
3077 // Forcibly initialize java/lang/StringValue and mutate the private
3078 // static final "stringCacheEnabled" field before we start creating instances
3079 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3080 // Possible that StringValue isn't present: if so, silently don't break
3081 if (k_o != NULL) {
3082 KlassHandle k = KlassHandle(THREAD, k_o);
3083 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3084 ik->initialize(CHECK_0);
3085 fieldDescriptor fd;
3086 // Possible we might not find this field: if so, silently don't break
3087 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3088 k()->bool_field_put(fd.offset(), true);
3089 }
3090 }
3091 }
3092 }
3093
3094 // Initialize java_lang.System (needed before creating the thread)
3095 if (InitializeJavaLangSystem) {
3096 initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0);
3097 initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0);
3098 Handle thread_group = create_initial_thread_group(CHECK_0);
3099 Universe::set_main_thread_group(thread_group());
3100 initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0);
3101 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3102 main_thread->set_threadObj(thread_object);
3103 // Set thread status to running since main thread has
3104 // been started and running.
3105 java_lang_Thread::set_thread_status(thread_object,
3106 java_lang_Thread::RUNNABLE);
3107
3108 // The VM preresolve methods to these classes. Make sure that get initialized
3109 initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0);
3110 initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0);
3111 // The VM creates & returns objects of this class. Make sure it's initialized.
3112 initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0);
3113 call_initializeSystemClass(CHECK_0);
3114 } else {
3115 warning("java.lang.System not initialized");
3116 }
3117
3118 // an instance of OutOfMemory exception has been allocated earlier
3119 if (InitializeJavaLangExceptionsErrors) {
3120 initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0);
3121 initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0);
3122 initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0);
3123 initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0);
3124 initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0);
3125 initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0);
3126 initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0);
3127 } else {
3128 warning("java.lang.OutOfMemoryError has not been initialized");
3129 warning("java.lang.NullPointerException has not been initialized");
3130 warning("java.lang.ClassCastException has not been initialized");
3131 warning("java.lang.ArrayStoreException has not been initialized");
3132 warning("java.lang.ArithmeticException has not been initialized");
3133 warning("java.lang.StackOverflowError has not been initialized");
3134 }
3135
3136 if (EnableInvokeDynamic) {
3137 // JSR 292: An intialized java.dyn.InvokeDynamic is required in
3138 // the compiler.
3139 initialize_class(vmSymbolHandles::java_dyn_InvokeDynamic(), CHECK_0);
3140 }
3141 }
3142
3143 // See : bugid 4211085.
3144 // Background : the static initializer of java.lang.Compiler tries to read
3145 // property"java.compiler" and read & write property "java.vm.info".
3146 // When a security manager is installed through the command line
3147 // option "-Djava.security.manager", the above properties are not
3148 // readable and the static initializer for java.lang.Compiler fails
3149 // resulting in a NoClassDefFoundError. This can happen in any
3150 // user code which calls methods in java.lang.Compiler.
3151 // Hack : the hack is to pre-load and initialize this class, so that only
3152 // system domains are on the stack when the properties are read.
3153 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3154 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3155 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3156 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3157 // Once that is done, we should remove this hack.
3158 initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0);
3159
3160 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3161 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3162 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3163 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3164 // This should also be taken out as soon as 4211383 gets fixed.
3165 reset_vm_info_property(CHECK_0);
3166
3167 quicken_jni_functions();
3168
3169 // Set flag that basic initialization has completed. Used by exceptions and various
3170 // debug stuff, that does not work until all basic classes have been initialized.
3171 set_init_completed();
3172
3173 HS_DTRACE_PROBE(hotspot, vm__init__end);
3174
3175 // record VM initialization completion time
3176 Management::record_vm_init_completed();
3177
3178 // Compute system loader. Note that this has to occur after set_init_completed, since
3179 // valid exceptions may be thrown in the process.
3180 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3181 // set_init_completed has just been called, causing exceptions not to be shortcut
3182 // anymore. We call vm_exit_during_initialization directly instead.
3183 SystemDictionary::compute_java_system_loader(THREAD);
3184 if (HAS_PENDING_EXCEPTION) {
3185 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3186 }
3187
3188 #ifdef KERNEL
3189 if (JDK_Version::is_gte_jdk17x_version()) {
3190 set_jkernel_boot_classloader_hook(THREAD);
3191 }
3192 #endif // KERNEL
3193
3194 #ifndef SERIALGC
3195 // Support for ConcurrentMarkSweep. This should be cleaned up
3196 // and better encapsulated. The ugly nested if test would go away
3197 // once things are properly refactored. XXX YSR
3198 if (UseConcMarkSweepGC || UseG1GC) {
3199 if (UseConcMarkSweepGC) {
3200 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3201 } else {
3202 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3203 }
3204 if (HAS_PENDING_EXCEPTION) {
3205 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3206 }
3207 }
3208 #endif // SERIALGC
3209
3210 // Always call even when there are not JVMTI environments yet, since environments
3211 // may be attached late and JVMTI must track phases of VM execution
3212 JvmtiExport::enter_live_phase();
3213
3214 // Signal Dispatcher needs to be started before VMInit event is posted
3215 os::signal_init();
3216
3217 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3218 if (!DisableAttachMechanism) {
3219 if (StartAttachListener || AttachListener::init_at_startup()) {
3220 AttachListener::init();
3221 }
3222 }
3223
3224 // Launch -Xrun agents
3225 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3226 // back-end can launch with -Xdebug -Xrunjdwp.
3227 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3228 create_vm_init_libraries();
3229 }
3230
3231 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3232 JvmtiExport::post_vm_initialized();
3233
3234 Chunk::start_chunk_pool_cleaner_task();
3235
3236 // initialize compiler(s)
3237 CompileBroker::compilation_init();
3238
3239 Management::initialize(THREAD);
3240 if (HAS_PENDING_EXCEPTION) {
3241 // management agent fails to start possibly due to
3242 // configuration problem and is responsible for printing
3243 // stack trace if appropriate. Simply exit VM.
3244 vm_exit(1);
3245 }
3246
3247 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3248 if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
3249 if (MemProfiling) MemProfiler::engage();
3250 StatSampler::engage();
3251 if (CheckJNICalls) JniPeriodicChecker::engage();
3252
3253 BiasedLocking::init();
3254
3255
3256 // Start up the WatcherThread if there are any periodic tasks
3257 // NOTE: All PeriodicTasks should be registered by now. If they
3258 // aren't, late joiners might appear to start slowly (we might
3259 // take a while to process their first tick).
3260 if (PeriodicTask::num_tasks() > 0) {
3261 WatcherThread::start();
3262 }
3263
3264 // Give os specific code one last chance to start
3265 os::init_3();
3266
3267 create_vm_timer.end();
3268 return JNI_OK;
3269 }
3270
3271 // type for the Agent_OnLoad and JVM_OnLoad entry points
3272 extern "C" {
3273 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3274 }
3275 // Find a command line agent library and return its entry point for
3276 // -agentlib: -agentpath: -Xrun
3277 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3278 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3279 OnLoadEntry_t on_load_entry = NULL;
3280 void *library = agent->os_lib(); // check if we have looked it up before
3281
3282 if (library == NULL) {
3283 char buffer[JVM_MAXPATHLEN];
3284 char ebuf[1024];
3285 const char *name = agent->name();
3286 const char *msg = "Could not find agent library ";
3287
3288 if (agent->is_absolute_path()) {
3289 library = hpi::dll_load(name, ebuf, sizeof ebuf);
3290 if (library == NULL) {
3291 const char *sub_msg = " in absolute path, with error: ";
3292 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3293 char *buf = NEW_C_HEAP_ARRAY(char, len);
3294 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3295 // If we can't find the agent, exit.
3296 vm_exit_during_initialization(buf, NULL);
3297 FREE_C_HEAP_ARRAY(char, buf);
3298 }
3299 } else {
3300 // Try to load the agent from the standard dll directory
3301 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name);
3302 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3303 #ifdef KERNEL
3304 // Download instrument dll
3305 if (library == NULL && strcmp(name, "instrument") == 0) {
3306 char *props = Arguments::get_kernel_properties();
3307 char *home = Arguments::get_java_home();
3308 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false"
3309 " sun.jkernel.DownloadManager -download client_jvm";
3310 size_t length = strlen(props) + strlen(home) + strlen(fmt) + 1;
3311 char *cmd = NEW_C_HEAP_ARRAY(char, length);
3312 jio_snprintf(cmd, length, fmt, home, props);
3313 int status = os::fork_and_exec(cmd);
3314 FreeHeap(props);
3315 if (status == -1) {
3316 warning(cmd);
3317 vm_exit_during_initialization("fork_and_exec failed: %s",
3318 strerror(errno));
3319 }
3320 FREE_C_HEAP_ARRAY(char, cmd);
3321 // when this comes back the instrument.dll should be where it belongs.
3322 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3323 }
3324 #endif // KERNEL
3325 if (library == NULL) { // Try the local directory
3326 char ns[1] = {0};
3327 hpi::dll_build_name(buffer, sizeof(buffer), ns, name);
3328 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3329 if (library == NULL) {
3330 const char *sub_msg = " on the library path, with error: ";
3331 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3332 char *buf = NEW_C_HEAP_ARRAY(char, len);
3333 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3334 // If we can't find the agent, exit.
3335 vm_exit_during_initialization(buf, NULL);
3336 FREE_C_HEAP_ARRAY(char, buf);
3337 }
3338 }
3339 }
3340 agent->set_os_lib(library);
3341 }
3342
3343 // Find the OnLoad function.
3344 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
3345 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index]));
3346 if (on_load_entry != NULL) break;
3347 }
3348 return on_load_entry;
3349 }
3350
3351 // Find the JVM_OnLoad entry point
3352 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3353 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3354 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3355 }
3356
3357 // Find the Agent_OnLoad entry point
3358 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3359 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3360 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3361 }
3362
3363 // For backwards compatibility with -Xrun
3364 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3365 // treated like -agentpath:
3366 // Must be called before agent libraries are created
3367 void Threads::convert_vm_init_libraries_to_agents() {
3368 AgentLibrary* agent;
3369 AgentLibrary* next;
3370
3371 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3372 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3373 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3374
3375 // If there is an JVM_OnLoad function it will get called later,
3376 // otherwise see if there is an Agent_OnLoad
3377 if (on_load_entry == NULL) {
3378 on_load_entry = lookup_agent_on_load(agent);
3379 if (on_load_entry != NULL) {
3380 // switch it to the agent list -- so that Agent_OnLoad will be called,
3381 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3382 Arguments::convert_library_to_agent(agent);
3383 } else {
3384 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3385 }
3386 }
3387 }
3388 }
3389
3390 // Create agents for -agentlib: -agentpath: and converted -Xrun
3391 // Invokes Agent_OnLoad
3392 // Called very early -- before JavaThreads exist
3393 void Threads::create_vm_init_agents() {
3394 extern struct JavaVM_ main_vm;
3395 AgentLibrary* agent;
3396
3397 JvmtiExport::enter_onload_phase();
3398 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3399 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3400
3401 if (on_load_entry != NULL) {
3402 // Invoke the Agent_OnLoad function
3403 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3404 if (err != JNI_OK) {
3405 vm_exit_during_initialization("agent library failed to init", agent->name());
3406 }
3407 } else {
3408 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3409 }
3410 }
3411 JvmtiExport::enter_primordial_phase();
3412 }
3413
3414 extern "C" {
3415 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3416 }
3417
3418 void Threads::shutdown_vm_agents() {
3419 // Send any Agent_OnUnload notifications
3420 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3421 extern struct JavaVM_ main_vm;
3422 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3423
3424 // Find the Agent_OnUnload function.
3425 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
3426 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3427 hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
3428
3429 // Invoke the Agent_OnUnload function
3430 if (unload_entry != NULL) {
3431 JavaThread* thread = JavaThread::current();
3432 ThreadToNativeFromVM ttn(thread);
3433 HandleMark hm(thread);
3434 (*unload_entry)(&main_vm);
3435 break;
3436 }
3437 }
3438 }
3439 }
3440
3441 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3442 // Invokes JVM_OnLoad
3443 void Threads::create_vm_init_libraries() {
3444 extern struct JavaVM_ main_vm;
3445 AgentLibrary* agent;
3446
3447 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3448 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3449
3450 if (on_load_entry != NULL) {
3451 // Invoke the JVM_OnLoad function
3452 JavaThread* thread = JavaThread::current();
3453 ThreadToNativeFromVM ttn(thread);
3454 HandleMark hm(thread);
3455 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3456 if (err != JNI_OK) {
3457 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3458 }
3459 } else {
3460 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3461 }
3462 }
3463 }
3464
3465 // Last thread running calls java.lang.Shutdown.shutdown()
3466 void JavaThread::invoke_shutdown_hooks() {
3467 HandleMark hm(this);
3468
3469 // We could get here with a pending exception, if so clear it now.
3470 if (this->has_pending_exception()) {
3471 this->clear_pending_exception();
3472 }
3473
3474 EXCEPTION_MARK;
3475 klassOop k =
3476 SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(),
3477 THREAD);
3478 if (k != NULL) {
3479 // SystemDictionary::resolve_or_null will return null if there was
3480 // an exception. If we cannot load the Shutdown class, just don't
3481 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3482 // and finalizers (if runFinalizersOnExit is set) won't be run.
3483 // Note that if a shutdown hook was registered or runFinalizersOnExit
3484 // was called, the Shutdown class would have already been loaded
3485 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3486 instanceKlassHandle shutdown_klass (THREAD, k);
3487 JavaValue result(T_VOID);
3488 JavaCalls::call_static(&result,
3489 shutdown_klass,
3490 vmSymbolHandles::shutdown_method_name(),
3491 vmSymbolHandles::void_method_signature(),
3492 THREAD);
3493 }
3494 CLEAR_PENDING_EXCEPTION;
3495 }
3496
3497 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3498 // the program falls off the end of main(). Another VM exit path is through
3499 // vm_exit() when the program calls System.exit() to return a value or when
3500 // there is a serious error in VM. The two shutdown paths are not exactly
3501 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3502 // and VM_Exit op at VM level.
3503 //
3504 // Shutdown sequence:
3505 // + Wait until we are the last non-daemon thread to execute
3506 // <-- every thing is still working at this moment -->
3507 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3508 // shutdown hooks, run finalizers if finalization-on-exit
3509 // + Call before_exit(), prepare for VM exit
3510 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3511 // currently the only user of this mechanism is File.deleteOnExit())
3512 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3513 // post thread end and vm death events to JVMTI,
3514 // stop signal thread
3515 // + Call JavaThread::exit(), it will:
3516 // > release JNI handle blocks, remove stack guard pages
3517 // > remove this thread from Threads list
3518 // <-- no more Java code from this thread after this point -->
3519 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3520 // the compiler threads at safepoint
3521 // <-- do not use anything that could get blocked by Safepoint -->
3522 // + Disable tracing at JNI/JVM barriers
3523 // + Set _vm_exited flag for threads that are still running native code
3524 // + Delete this thread
3525 // + Call exit_globals()
3526 // > deletes tty
3527 // > deletes PerfMemory resources
3528 // + Return to caller
3529
3530 bool Threads::destroy_vm() {
3531 JavaThread* thread = JavaThread::current();
3532
3533 // Wait until we are the last non-daemon thread to execute
3534 { MutexLocker nu(Threads_lock);
3535 while (Threads::number_of_non_daemon_threads() > 1 )
3536 // This wait should make safepoint checks, wait without a timeout,
3537 // and wait as a suspend-equivalent condition.
3538 //
3539 // Note: If the FlatProfiler is running and this thread is waiting
3540 // for another non-daemon thread to finish, then the FlatProfiler
3541 // is waiting for the external suspend request on this thread to
3542 // complete. wait_for_ext_suspend_completion() will eventually
3543 // timeout, but that takes time. Making this wait a suspend-
3544 // equivalent condition solves that timeout problem.
3545 //
3546 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
3547 Mutex::_as_suspend_equivalent_flag);
3548 }
3549
3550 // Hang forever on exit if we are reporting an error.
3551 if (ShowMessageBoxOnError && is_error_reported()) {
3552 os::infinite_sleep();
3553 }
3554
3555 if (JDK_Version::is_jdk12x_version()) {
3556 // We are the last thread running, so check if finalizers should be run.
3557 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
3558 HandleMark rm(thread);
3559 Universe::run_finalizers_on_exit();
3560 } else {
3561 // run Java level shutdown hooks
3562 thread->invoke_shutdown_hooks();
3563 }
3564
3565 before_exit(thread);
3566
3567 thread->exit(true);
3568
3569 // Stop VM thread.
3570 {
3571 // 4945125 The vm thread comes to a safepoint during exit.
3572 // GC vm_operations can get caught at the safepoint, and the
3573 // heap is unparseable if they are caught. Grab the Heap_lock
3574 // to prevent this. The GC vm_operations will not be able to
3575 // queue until after the vm thread is dead.
3576 MutexLocker ml(Heap_lock);
3577
3578 VMThread::wait_for_vm_thread_exit();
3579 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3580 VMThread::destroy();
3581 }
3582
3583 // clean up ideal graph printers
3584 #if defined(COMPILER2) && !defined(PRODUCT)
3585 IdealGraphPrinter::clean_up();
3586 #endif
3587
3588 // Now, all Java threads are gone except daemon threads. Daemon threads
3589 // running Java code or in VM are stopped by the Safepoint. However,
3590 // daemon threads executing native code are still running. But they
3591 // will be stopped at native=>Java/VM barriers. Note that we can't
3592 // simply kill or suspend them, as it is inherently deadlock-prone.
3593
3594 #ifndef PRODUCT
3595 // disable function tracing at JNI/JVM barriers
3596 TraceHPI = false;
3597 TraceJNICalls = false;
3598 TraceJVMCalls = false;
3599 TraceRuntimeCalls = false;
3600 #endif
3601
3602 VM_Exit::set_vm_exited();
3603
3604 notify_vm_shutdown();
3605
3606 delete thread;
3607
3608 // exit_globals() will delete tty
3609 exit_globals();
3610
3611 return true;
3612 }
3613
3614
3615 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3616 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3617 return is_supported_jni_version(version);
3618 }
3619
3620
3621 jboolean Threads::is_supported_jni_version(jint version) {
3622 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3623 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3624 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3625 return JNI_FALSE;
3626 }
3627
3628
3629 void Threads::add(JavaThread* p, bool force_daemon) {
3630 // The threads lock must be owned at this point
3631 assert_locked_or_safepoint(Threads_lock);
3632 p->set_next(_thread_list);
3633 _thread_list = p;
3634 _number_of_threads++;
3635 oop threadObj = p->threadObj();
3636 bool daemon = true;
3637 // Bootstrapping problem: threadObj can be null for initial
3638 // JavaThread (or for threads attached via JNI)
3639 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
3640 _number_of_non_daemon_threads++;
3641 daemon = false;
3642 }
3643
3644 ThreadService::add_thread(p, daemon);
3645
3646 // Possible GC point.
3647 Events::log("Thread added: " INTPTR_FORMAT, p);
3648 }
3649
3650 void Threads::remove(JavaThread* p) {
3651 // Extra scope needed for Thread_lock, so we can check
3652 // that we do not remove thread without safepoint code notice
3653 { MutexLocker ml(Threads_lock);
3654
3655 assert(includes(p), "p must be present");
3656
3657 JavaThread* current = _thread_list;
3658 JavaThread* prev = NULL;
3659
3660 while (current != p) {
3661 prev = current;
3662 current = current->next();
3663 }
3664
3665 if (prev) {
3666 prev->set_next(current->next());
3667 } else {
3668 _thread_list = p->next();
3669 }
3670 _number_of_threads--;
3671 oop threadObj = p->threadObj();
3672 bool daemon = true;
3673 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
3674 _number_of_non_daemon_threads--;
3675 daemon = false;
3676
3677 // Only one thread left, do a notify on the Threads_lock so a thread waiting
3678 // on destroy_vm will wake up.
3679 if (number_of_non_daemon_threads() == 1)
3680 Threads_lock->notify_all();
3681 }
3682 ThreadService::remove_thread(p, daemon);
3683
3684 // Make sure that safepoint code disregard this thread. This is needed since
3685 // the thread might mess around with locks after this point. This can cause it
3686 // to do callbacks into the safepoint code. However, the safepoint code is not aware
3687 // of this thread since it is removed from the queue.
3688 p->set_terminated_value();
3689 } // unlock Threads_lock
3690
3691 // Since Events::log uses a lock, we grab it outside the Threads_lock
3692 Events::log("Thread exited: " INTPTR_FORMAT, p);
3693 }
3694
3695 // Threads_lock must be held when this is called (or must be called during a safepoint)
3696 bool Threads::includes(JavaThread* p) {
3697 assert(Threads_lock->is_locked(), "sanity check");
3698 ALL_JAVA_THREADS(q) {
3699 if (q == p ) {
3700 return true;
3701 }
3702 }
3703 return false;
3704 }
3705
3706 // Operations on the Threads list for GC. These are not explicitly locked,
3707 // but the garbage collector must provide a safe context for them to run.
3708 // In particular, these things should never be called when the Threads_lock
3709 // is held by some other thread. (Note: the Safepoint abstraction also
3710 // uses the Threads_lock to gurantee this property. It also makes sure that
3711 // all threads gets blocked when exiting or starting).
3712
3713 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3714 ALL_JAVA_THREADS(p) {
3715 p->oops_do(f, cf);
3716 }
3717 VMThread::vm_thread()->oops_do(f, cf);
3718 }
3719
3720 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) {
3721 // Introduce a mechanism allowing parallel threads to claim threads as
3722 // root groups. Overhead should be small enough to use all the time,
3723 // even in sequential code.
3724 SharedHeap* sh = SharedHeap::heap();
3725 bool is_par = (sh->n_par_threads() > 0);
3726 int cp = SharedHeap::heap()->strong_roots_parity();
3727 ALL_JAVA_THREADS(p) {
3728 if (p->claim_oops_do(is_par, cp)) {
3729 p->oops_do(f, cf);
3730 }
3731 }
3732 VMThread* vmt = VMThread::vm_thread();
3733 if (vmt->claim_oops_do(is_par, cp))
3734 vmt->oops_do(f, cf);
3735 }
3736
3737 #ifndef SERIALGC
3738 // Used by ParallelScavenge
3739 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
3740 ALL_JAVA_THREADS(p) {
3741 q->enqueue(new ThreadRootsTask(p));
3742 }
3743 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
3744 }
3745
3746 // Used by Parallel Old
3747 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
3748 ALL_JAVA_THREADS(p) {
3749 q->enqueue(new ThreadRootsMarkingTask(p));
3750 }
3751 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
3752 }
3753 #endif // SERIALGC
3754
3755 void Threads::nmethods_do(CodeBlobClosure* cf) {
3756 ALL_JAVA_THREADS(p) {
3757 p->nmethods_do(cf);
3758 }
3759 VMThread::vm_thread()->nmethods_do(cf);
3760 }
3761
3762 void Threads::gc_epilogue() {
3763 ALL_JAVA_THREADS(p) {
3764 p->gc_epilogue();
3765 }
3766 }
3767
3768 void Threads::gc_prologue() {
3769 ALL_JAVA_THREADS(p) {
3770 p->gc_prologue();
3771 }
3772 }
3773
3774 void Threads::deoptimized_wrt_marked_nmethods() {
3775 ALL_JAVA_THREADS(p) {
3776 p->deoptimized_wrt_marked_nmethods();
3777 }
3778 }
3779
3780
3781 // Get count Java threads that are waiting to enter the specified monitor.
3782 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
3783 address monitor, bool doLock) {
3784 assert(doLock || SafepointSynchronize::is_at_safepoint(),
3785 "must grab Threads_lock or be at safepoint");
3786 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
3787
3788 int i = 0;
3789 {
3790 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3791 ALL_JAVA_THREADS(p) {
3792 if (p->is_Compiler_thread()) continue;
3793
3794 address pending = (address)p->current_pending_monitor();
3795 if (pending == monitor) { // found a match
3796 if (i < count) result->append(p); // save the first count matches
3797 i++;
3798 }
3799 }
3800 }
3801 return result;
3802 }
3803
3804
3805 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
3806 assert(doLock ||
3807 Threads_lock->owned_by_self() ||
3808 SafepointSynchronize::is_at_safepoint(),
3809 "must grab Threads_lock or be at safepoint");
3810
3811 // NULL owner means not locked so we can skip the search
3812 if (owner == NULL) return NULL;
3813
3814 {
3815 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3816 ALL_JAVA_THREADS(p) {
3817 // first, see if owner is the address of a Java thread
3818 if (owner == (address)p) return p;
3819 }
3820 }
3821 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
3822 if (UseHeavyMonitors) return NULL;
3823
3824 //
3825 // If we didn't find a matching Java thread and we didn't force use of
3826 // heavyweight monitors, then the owner is the stack address of the
3827 // Lock Word in the owning Java thread's stack.
3828 //
3829 JavaThread* the_owner = NULL;
3830 {
3831 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3832 ALL_JAVA_THREADS(q) {
3833 if (q->is_lock_owned(owner)) {
3834 the_owner = q;
3835 break;
3836 }
3837 }
3838 }
3839 assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
3840 return the_owner;
3841 }
3842
3843 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
3844 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
3845 char buf[32];
3846 st->print_cr(os::local_time_string(buf, sizeof(buf)));
3847
3848 st->print_cr("Full thread dump %s (%s %s):",
3849 Abstract_VM_Version::vm_name(),
3850 Abstract_VM_Version::vm_release(),
3851 Abstract_VM_Version::vm_info_string()
3852 );
3853 st->cr();
3854
3855 #ifndef SERIALGC
3856 // Dump concurrent locks
3857 ConcurrentLocksDump concurrent_locks;
3858 if (print_concurrent_locks) {
3859 concurrent_locks.dump_at_safepoint();
3860 }
3861 #endif // SERIALGC
3862
3863 ALL_JAVA_THREADS(p) {
3864 ResourceMark rm;
3865 p->print_on(st);
3866 if (print_stacks) {
3867 if (internal_format) {
3868 p->trace_stack();
3869 } else {
3870 p->print_stack_on(st);
3871 }
3872 }
3873 st->cr();
3874 #ifndef SERIALGC
3875 if (print_concurrent_locks) {
3876 concurrent_locks.print_locks_on(p, st);
3877 }
3878 #endif // SERIALGC
3879 }
3880
3881 VMThread::vm_thread()->print_on(st);
3882 st->cr();
3883 Universe::heap()->print_gc_threads_on(st);
3884 WatcherThread* wt = WatcherThread::watcher_thread();
3885 if (wt != NULL) wt->print_on(st);
3886 st->cr();
3887 CompileBroker::print_compiler_threads_on(st);
3888 st->flush();
3889 }
3890
3891 // Threads::print_on_error() is called by fatal error handler. It's possible
3892 // that VM is not at safepoint and/or current thread is inside signal handler.
3893 // Don't print stack trace, as the stack may not be walkable. Don't allocate
3894 // memory (even in resource area), it might deadlock the error handler.
3895 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
3896 bool found_current = false;
3897 st->print_cr("Java Threads: ( => current thread )");
3898 ALL_JAVA_THREADS(thread) {
3899 bool is_current = (current == thread);
3900 found_current = found_current || is_current;
3901
3902 st->print("%s", is_current ? "=>" : " ");
3903
3904 st->print(PTR_FORMAT, thread);
3905 st->print(" ");
3906 thread->print_on_error(st, buf, buflen);
3907 st->cr();
3908 }
3909 st->cr();
3910
3911 st->print_cr("Other Threads:");
3912 if (VMThread::vm_thread()) {
3913 bool is_current = (current == VMThread::vm_thread());
3914 found_current = found_current || is_current;
3915 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
3916
3917 st->print(PTR_FORMAT, VMThread::vm_thread());
3918 st->print(" ");
3919 VMThread::vm_thread()->print_on_error(st, buf, buflen);
3920 st->cr();
3921 }
3922 WatcherThread* wt = WatcherThread::watcher_thread();
3923 if (wt != NULL) {
3924 bool is_current = (current == wt);
3925 found_current = found_current || is_current;
3926 st->print("%s", is_current ? "=>" : " ");
3927
3928 st->print(PTR_FORMAT, wt);
3929 st->print(" ");
3930 wt->print_on_error(st, buf, buflen);
3931 st->cr();
3932 }
3933 if (!found_current) {
3934 st->cr();
3935 st->print("=>" PTR_FORMAT " (exited) ", current);
3936 current->print_on_error(st, buf, buflen);
3937 st->cr();
3938 }
3939 }
3940
3941
3942 // Lifecycle management for TSM ParkEvents.
3943 // ParkEvents are type-stable (TSM).
3944 // In our particular implementation they happen to be immortal.
3945 //
3946 // We manage concurrency on the FreeList with a CAS-based
3947 // detach-modify-reattach idiom that avoids the ABA problems
3948 // that would otherwise be present in a simple CAS-based
3949 // push-pop implementation. (push-one and pop-all)
3950 //
3951 // Caveat: Allocate() and Release() may be called from threads
3952 // other than the thread associated with the Event!
3953 // If we need to call Allocate() when running as the thread in
3954 // question then look for the PD calls to initialize native TLS.
3955 // Native TLS (Win32/Linux/Solaris) can only be initialized or
3956 // accessed by the associated thread.
3957 // See also pd_initialize().
3958 //
3959 // Note that we could defer associating a ParkEvent with a thread
3960 // until the 1st time the thread calls park(). unpark() calls to
3961 // an unprovisioned thread would be ignored. The first park() call
3962 // for a thread would allocate and associate a ParkEvent and return
3963 // immediately.
3964
3965 volatile int ParkEvent::ListLock = 0 ;
3966 ParkEvent * volatile ParkEvent::FreeList = NULL ;
3967
3968 ParkEvent * ParkEvent::Allocate (Thread * t) {
3969 // In rare cases -- JVM_RawMonitor* operations -- we can find t == null.
3970 ParkEvent * ev ;
3971
3972 // Start by trying to recycle an existing but unassociated
3973 // ParkEvent from the global free list.
3974 for (;;) {
3975 ev = FreeList ;
3976 if (ev == NULL) break ;
3977 // 1: Detach - sequester or privatize the list
3978 // Tantamount to ev = Swap (&FreeList, NULL)
3979 if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) {
3980 continue ;
3981 }
3982
3983 // We've detached the list. The list in-hand is now
3984 // local to this thread. This thread can operate on the
3985 // list without risk of interference from other threads.
3986 // 2: Extract -- pop the 1st element from the list.
3987 ParkEvent * List = ev->FreeNext ;
3988 if (List == NULL) break ;
3989 for (;;) {
3990 // 3: Try to reattach the residual list
3991 guarantee (List != NULL, "invariant") ;
3992 ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
3993 if (Arv == NULL) break ;
3994
3995 // New nodes arrived. Try to detach the recent arrivals.
3996 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
3997 continue ;
3998 }
3999 guarantee (Arv != NULL, "invariant") ;
4000 // 4: Merge Arv into List
4001 ParkEvent * Tail = List ;
4002 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
4003 Tail->FreeNext = Arv ;
4004 }
4005 break ;
4006 }
4007
4008 if (ev != NULL) {
4009 guarantee (ev->AssociatedWith == NULL, "invariant") ;
4010 } else {
4011 // Do this the hard way -- materialize a new ParkEvent.
4012 // In rare cases an allocating thread might detach a long list --
4013 // installing null into FreeList -- and then stall or be obstructed.
4014 // A 2nd thread calling Allocate() would see FreeList == null.
4015 // The list held privately by the 1st thread is unavailable to the 2nd thread.
4016 // In that case the 2nd thread would have to materialize a new ParkEvent,
4017 // even though free ParkEvents existed in the system. In this case we end up
4018 // with more ParkEvents in circulation than we need, but the race is
4019 // rare and the outcome is benign. Ideally, the # of extant ParkEvents
4020 // is equal to the maximum # of threads that existed at any one time.
4021 // Because of the race mentioned above, segments of the freelist
4022 // can be transiently inaccessible. At worst we may end up with the
4023 // # of ParkEvents in circulation slightly above the ideal.
4024 // Note that if we didn't have the TSM/immortal constraint, then
4025 // when reattaching, above, we could trim the list.
4026 ev = new ParkEvent () ;
4027 guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ;
4028 }
4029 ev->reset() ; // courtesy to caller
4030 ev->AssociatedWith = t ; // Associate ev with t
4031 ev->FreeNext = NULL ;
4032 return ev ;
4033 }
4034
4035 void ParkEvent::Release (ParkEvent * ev) {
4036 if (ev == NULL) return ;
4037 guarantee (ev->FreeNext == NULL , "invariant") ;
4038 ev->AssociatedWith = NULL ;
4039 for (;;) {
4040 // Push ev onto FreeList
4041 // The mechanism is "half" lock-free.
4042 ParkEvent * List = FreeList ;
4043 ev->FreeNext = List ;
4044 if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ;
4045 }
4046 }
4047
4048 // Override operator new and delete so we can ensure that the
4049 // least significant byte of ParkEvent addresses is 0.
4050 // Beware that excessive address alignment is undesirable
4051 // as it can result in D$ index usage imbalance as
4052 // well as bank access imbalance on Niagara-like platforms,
4053 // although Niagara's hash function should help.
4054
4055 void * ParkEvent::operator new (size_t sz) {
4056 return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ;
4057 }
4058
4059 void ParkEvent::operator delete (void * a) {
4060 // ParkEvents are type-stable and immortal ...
4061 ShouldNotReachHere();
4062 }
4063
4064
4065 // 6399321 As a temporary measure we copied & modified the ParkEvent::
4066 // allocate() and release() code for use by Parkers. The Parker:: forms
4067 // will eventually be removed as we consolide and shift over to ParkEvents
4068 // for both builtin synchronization and JSR166 operations.
4069
4070 volatile int Parker::ListLock = 0 ;
4071 Parker * volatile Parker::FreeList = NULL ;
4072
4073 Parker * Parker::Allocate (JavaThread * t) {
4074 guarantee (t != NULL, "invariant") ;
4075 Parker * p ;
4076
4077 // Start by trying to recycle an existing but unassociated
4078 // Parker from the global free list.
4079 for (;;) {
4080 p = FreeList ;
4081 if (p == NULL) break ;
4082 // 1: Detach
4083 // Tantamount to p = Swap (&FreeList, NULL)
4084 if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) {
4085 continue ;
4086 }
4087
4088 // We've detached the list. The list in-hand is now
4089 // local to this thread. This thread can operate on the
4090 // list without risk of interference from other threads.
4091 // 2: Extract -- pop the 1st element from the list.
4092 Parker * List = p->FreeNext ;
4093 if (List == NULL) break ;
4094 for (;;) {
4095 // 3: Try to reattach the residual list
4096 guarantee (List != NULL, "invariant") ;
4097 Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
4098 if (Arv == NULL) break ;
4099
4100 // New nodes arrived. Try to detach the recent arrivals.
4101 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
4102 continue ;
4103 }
4104 guarantee (Arv != NULL, "invariant") ;
4105 // 4: Merge Arv into List
4106 Parker * Tail = List ;
4107 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
4108 Tail->FreeNext = Arv ;
4109 }
4110 break ;
4111 }
4112
4113 if (p != NULL) {
4114 guarantee (p->AssociatedWith == NULL, "invariant") ;
4115 } else {
4116 // Do this the hard way -- materialize a new Parker..
4117 // In rare cases an allocating thread might detach
4118 // a long list -- installing null into FreeList --and
4119 // then stall. Another thread calling Allocate() would see
4120 // FreeList == null and then invoke the ctor. In this case we
4121 // end up with more Parkers in circulation than we need, but
4122 // the race is rare and the outcome is benign.
4123 // Ideally, the # of extant Parkers is equal to the
4124 // maximum # of threads that existed at any one time.
4125 // Because of the race mentioned above, segments of the
4126 // freelist can be transiently inaccessible. At worst
4127 // we may end up with the # of Parkers in circulation
4128 // slightly above the ideal.
4129 p = new Parker() ;
4130 }
4131 p->AssociatedWith = t ; // Associate p with t
4132 p->FreeNext = NULL ;
4133 return p ;
4134 }
4135
4136
4137 void Parker::Release (Parker * p) {
4138 if (p == NULL) return ;
4139 guarantee (p->AssociatedWith != NULL, "invariant") ;
4140 guarantee (p->FreeNext == NULL , "invariant") ;
4141 p->AssociatedWith = NULL ;
4142 for (;;) {
4143 // Push p onto FreeList
4144 Parker * List = FreeList ;
4145 p->FreeNext = List ;
4146 if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ;
4147 }
4148 }
4149
4150 void Threads::verify() {
4151 ALL_JAVA_THREADS(p) {
4152 p->verify();
4153 }
4154 VMThread* thread = VMThread::vm_thread();
4155 if (thread != NULL) thread->verify();
4156 }