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 set_deopt_nmethod(NULL);
1187 clear_must_deopt_id();
1188 set_monitor_chunks(NULL);
1189 set_next(NULL);
1190 set_thread_state(_thread_new);
1191 _terminated = _not_terminated;
1192 _privileged_stack_top = NULL;
1193 _array_for_gc = NULL;
1194 _suspend_equivalent = false;
1195 _in_deopt_handler = 0;
1196 _doing_unsafe_access = false;
1197 _stack_guard_state = stack_guard_unused;
1198 _exception_oop = NULL;
1199 _exception_pc = 0;
1200 _exception_handler_pc = 0;
1201 _exception_stack_size = 0;
1202 _jvmti_thread_state= NULL;
1203 _should_post_on_exceptions_flag = JNI_FALSE;
1204 _jvmti_get_loaded_classes_closure = NULL;
1205 _interp_only_mode = 0;
1206 _special_runtime_exit_condition = _no_async_condition;
1207 _pending_async_exception = NULL;
1208 _is_compiling = false;
1209 _thread_stat = NULL;
1210 _thread_stat = new ThreadStatistics();
1211 _blocked_on_compilation = false;
1212 _jni_active_critical = 0;
1213 _do_not_unlock_if_synchronized = false;
1214 _cached_monitor_info = NULL;
1215 _parker = Parker::Allocate(this) ;
1216
1217 #ifndef PRODUCT
1218 _jmp_ring_index = 0;
1219 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1220 record_jump(NULL, NULL, NULL, 0);
1221 }
1222 #endif /* PRODUCT */
1223
1224 set_thread_profiler(NULL);
1225 if (FlatProfiler::is_active()) {
1226 // This is where we would decide to either give each thread it's own profiler
1227 // or use one global one from FlatProfiler,
1228 // or up to some count of the number of profiled threads, etc.
1229 ThreadProfiler* pp = new ThreadProfiler();
1230 pp->engage();
1231 set_thread_profiler(pp);
1232 }
1233
1234 // Setup safepoint state info for this thread
1235 ThreadSafepointState::create(this);
1236
1237 debug_only(_java_call_counter = 0);
1238
1239 // JVMTI PopFrame support
1240 _popframe_condition = popframe_inactive;
1241 _popframe_preserved_args = NULL;
1242 _popframe_preserved_args_size = 0;
1243
1244 pd_initialize();
1245 }
1246
1247 #ifndef SERIALGC
1248 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1249 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1250 #endif // !SERIALGC
1251
1252 JavaThread::JavaThread(bool is_attaching) :
1253 Thread()
1254 #ifndef SERIALGC
1255 , _satb_mark_queue(&_satb_mark_queue_set),
1256 _dirty_card_queue(&_dirty_card_queue_set)
1257 #endif // !SERIALGC
1258 {
1259 initialize();
1260 _is_attaching = is_attaching;
1261 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor");
1262 }
1263
1264 bool JavaThread::reguard_stack(address cur_sp) {
1265 if (_stack_guard_state != stack_guard_yellow_disabled) {
1266 return true; // Stack already guarded or guard pages not needed.
1267 }
1268
1269 if (register_stack_overflow()) {
1270 // For those architectures which have separate register and
1271 // memory stacks, we must check the register stack to see if
1272 // it has overflowed.
1273 return false;
1274 }
1275
1276 // Java code never executes within the yellow zone: the latter is only
1277 // there to provoke an exception during stack banging. If java code
1278 // is executing there, either StackShadowPages should be larger, or
1279 // some exception code in c1, c2 or the interpreter isn't unwinding
1280 // when it should.
1281 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1282
1283 enable_stack_yellow_zone();
1284 return true;
1285 }
1286
1287 bool JavaThread::reguard_stack(void) {
1288 return reguard_stack(os::current_stack_pointer());
1289 }
1290
1291
1292 void JavaThread::block_if_vm_exited() {
1293 if (_terminated == _vm_exited) {
1294 // _vm_exited is set at safepoint, and Threads_lock is never released
1295 // we will block here forever
1296 Threads_lock->lock_without_safepoint_check();
1297 ShouldNotReachHere();
1298 }
1299 }
1300
1301
1302 // Remove this ifdef when C1 is ported to the compiler interface.
1303 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1304
1305 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1306 Thread()
1307 #ifndef SERIALGC
1308 , _satb_mark_queue(&_satb_mark_queue_set),
1309 _dirty_card_queue(&_dirty_card_queue_set)
1310 #endif // !SERIALGC
1311 {
1312 if (TraceThreadEvents) {
1313 tty->print_cr("creating thread %p", this);
1314 }
1315 initialize();
1316 _is_attaching = false;
1317 set_entry_point(entry_point);
1318 // Create the native thread itself.
1319 // %note runtime_23
1320 os::ThreadType thr_type = os::java_thread;
1321 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1322 os::java_thread;
1323 os::create_thread(this, thr_type, stack_sz);
1324
1325 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1326 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1327 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1328 // the exception consists of creating the exception object & initializing it, initialization
1329 // will leave the VM via a JavaCall and then all locks must be unlocked).
1330 //
1331 // The thread is still suspended when we reach here. Thread must be explicit started
1332 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1333 // by calling Threads:add. The reason why this is not done here, is because the thread
1334 // object must be fully initialized (take a look at JVM_Start)
1335 }
1336
1337 JavaThread::~JavaThread() {
1338 if (TraceThreadEvents) {
1339 tty->print_cr("terminate thread %p", this);
1340 }
1341
1342 // JSR166 -- return the parker to the free list
1343 Parker::Release(_parker);
1344 _parker = NULL ;
1345
1346 // Free any remaining previous UnrollBlock
1347 vframeArray* old_array = vframe_array_last();
1348
1349 if (old_array != NULL) {
1350 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1351 old_array->set_unroll_block(NULL);
1352 delete old_info;
1353 delete old_array;
1354 }
1355
1356 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1357 if (deferred != NULL) {
1358 // This can only happen if thread is destroyed before deoptimization occurs.
1359 assert(deferred->length() != 0, "empty array!");
1360 do {
1361 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1362 deferred->remove_at(0);
1363 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1364 delete dlv;
1365 } while (deferred->length() != 0);
1366 delete deferred;
1367 }
1368
1369 // All Java related clean up happens in exit
1370 ThreadSafepointState::destroy(this);
1371 if (_thread_profiler != NULL) delete _thread_profiler;
1372 if (_thread_stat != NULL) delete _thread_stat;
1373 }
1374
1375
1376 // The first routine called by a new Java thread
1377 void JavaThread::run() {
1378 // initialize thread-local alloc buffer related fields
1379 this->initialize_tlab();
1380
1381 // used to test validitity of stack trace backs
1382 this->record_base_of_stack_pointer();
1383
1384 // Record real stack base and size.
1385 this->record_stack_base_and_size();
1386
1387 // Initialize thread local storage; set before calling MutexLocker
1388 this->initialize_thread_local_storage();
1389
1390 this->create_stack_guard_pages();
1391
1392 this->cache_global_variables();
1393
1394 // Thread is now sufficient initialized to be handled by the safepoint code as being
1395 // in the VM. Change thread state from _thread_new to _thread_in_vm
1396 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1397
1398 assert(JavaThread::current() == this, "sanity check");
1399 assert(!Thread::current()->owns_locks(), "sanity check");
1400
1401 DTRACE_THREAD_PROBE(start, this);
1402
1403 // This operation might block. We call that after all safepoint checks for a new thread has
1404 // been completed.
1405 this->set_active_handles(JNIHandleBlock::allocate_block());
1406
1407 if (JvmtiExport::should_post_thread_life()) {
1408 JvmtiExport::post_thread_start(this);
1409 }
1410
1411 // We call another function to do the rest so we are sure that the stack addresses used
1412 // from there will be lower than the stack base just computed
1413 thread_main_inner();
1414
1415 // Note, thread is no longer valid at this point!
1416 }
1417
1418
1419 void JavaThread::thread_main_inner() {
1420 assert(JavaThread::current() == this, "sanity check");
1421 assert(this->threadObj() != NULL, "just checking");
1422
1423 // Execute thread entry point. If this thread is being asked to restart,
1424 // or has been stopped before starting, do not reexecute entry point.
1425 // Note: Due to JVM_StopThread we can have pending exceptions already!
1426 if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) {
1427 // enter the thread's entry point only if we have no pending exceptions
1428 HandleMark hm(this);
1429 this->entry_point()(this, this);
1430 }
1431
1432 DTRACE_THREAD_PROBE(stop, this);
1433
1434 this->exit(false);
1435 delete this;
1436 }
1437
1438
1439 static void ensure_join(JavaThread* thread) {
1440 // We do not need to grap the Threads_lock, since we are operating on ourself.
1441 Handle threadObj(thread, thread->threadObj());
1442 assert(threadObj.not_null(), "java thread object must exist");
1443 ObjectLocker lock(threadObj, thread);
1444 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1445 thread->clear_pending_exception();
1446 // It is of profound importance that we set the stillborn bit and reset the thread object,
1447 // before we do the notify. Since, changing these two variable will make JVM_IsAlive return
1448 // false. So in case another thread is doing a join on this thread , it will detect that the thread
1449 // is dead when it gets notified.
1450 java_lang_Thread::set_stillborn(threadObj());
1451 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1452 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1453 java_lang_Thread::set_thread(threadObj(), NULL);
1454 lock.notify_all(thread);
1455 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1456 thread->clear_pending_exception();
1457 }
1458
1459
1460 // For any new cleanup additions, please check to see if they need to be applied to
1461 // cleanup_failed_attach_current_thread as well.
1462 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1463 assert(this == JavaThread::current(), "thread consistency check");
1464 if (!InitializeJavaLangSystem) return;
1465
1466 HandleMark hm(this);
1467 Handle uncaught_exception(this, this->pending_exception());
1468 this->clear_pending_exception();
1469 Handle threadObj(this, this->threadObj());
1470 assert(threadObj.not_null(), "Java thread object should be created");
1471
1472 if (get_thread_profiler() != NULL) {
1473 get_thread_profiler()->disengage();
1474 ResourceMark rm;
1475 get_thread_profiler()->print(get_thread_name());
1476 }
1477
1478
1479 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1480 {
1481 EXCEPTION_MARK;
1482
1483 CLEAR_PENDING_EXCEPTION;
1484 }
1485 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1486 // has to be fixed by a runtime query method
1487 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1488 // JSR-166: change call from from ThreadGroup.uncaughtException to
1489 // java.lang.Thread.dispatchUncaughtException
1490 if (uncaught_exception.not_null()) {
1491 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1492 Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT",
1493 (address)uncaught_exception(), (address)threadObj(), (address)group());
1494 {
1495 EXCEPTION_MARK;
1496 // Check if the method Thread.dispatchUncaughtException() exists. If so
1497 // call it. Otherwise we have an older library without the JSR-166 changes,
1498 // so call ThreadGroup.uncaughtException()
1499 KlassHandle recvrKlass(THREAD, threadObj->klass());
1500 CallInfo callinfo;
1501 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1502 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1503 vmSymbolHandles::dispatchUncaughtException_name(),
1504 vmSymbolHandles::throwable_void_signature(),
1505 KlassHandle(), false, false, THREAD);
1506 CLEAR_PENDING_EXCEPTION;
1507 methodHandle method = callinfo.selected_method();
1508 if (method.not_null()) {
1509 JavaValue result(T_VOID);
1510 JavaCalls::call_virtual(&result,
1511 threadObj, thread_klass,
1512 vmSymbolHandles::dispatchUncaughtException_name(),
1513 vmSymbolHandles::throwable_void_signature(),
1514 uncaught_exception,
1515 THREAD);
1516 } else {
1517 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1518 JavaValue result(T_VOID);
1519 JavaCalls::call_virtual(&result,
1520 group, thread_group,
1521 vmSymbolHandles::uncaughtException_name(),
1522 vmSymbolHandles::thread_throwable_void_signature(),
1523 threadObj, // Arg 1
1524 uncaught_exception, // Arg 2
1525 THREAD);
1526 }
1527 CLEAR_PENDING_EXCEPTION;
1528 }
1529 }
1530
1531 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1532 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1533 // is deprecated anyhow.
1534 { int count = 3;
1535 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1536 EXCEPTION_MARK;
1537 JavaValue result(T_VOID);
1538 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1539 JavaCalls::call_virtual(&result,
1540 threadObj, thread_klass,
1541 vmSymbolHandles::exit_method_name(),
1542 vmSymbolHandles::void_method_signature(),
1543 THREAD);
1544 CLEAR_PENDING_EXCEPTION;
1545 }
1546 }
1547
1548 // notify JVMTI
1549 if (JvmtiExport::should_post_thread_life()) {
1550 JvmtiExport::post_thread_end(this);
1551 }
1552
1553 // We have notified the agents that we are exiting, before we go on,
1554 // we must check for a pending external suspend request and honor it
1555 // in order to not surprise the thread that made the suspend request.
1556 while (true) {
1557 {
1558 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1559 if (!is_external_suspend()) {
1560 set_terminated(_thread_exiting);
1561 ThreadService::current_thread_exiting(this);
1562 break;
1563 }
1564 // Implied else:
1565 // Things get a little tricky here. We have a pending external
1566 // suspend request, but we are holding the SR_lock so we
1567 // can't just self-suspend. So we temporarily drop the lock
1568 // and then self-suspend.
1569 }
1570
1571 ThreadBlockInVM tbivm(this);
1572 java_suspend_self();
1573
1574 // We're done with this suspend request, but we have to loop around
1575 // and check again. Eventually we will get SR_lock without a pending
1576 // external suspend request and will be able to mark ourselves as
1577 // exiting.
1578 }
1579 // no more external suspends are allowed at this point
1580 } else {
1581 // before_exit() has already posted JVMTI THREAD_END events
1582 }
1583
1584 // Notify waiters on thread object. This has to be done after exit() is called
1585 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1586 // group should have the destroyed bit set before waiters are notified).
1587 ensure_join(this);
1588 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1589
1590 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1591 // held by this thread must be released. A detach operation must only
1592 // get here if there are no Java frames on the stack. Therefore, any
1593 // owned monitors at this point MUST be JNI-acquired monitors which are
1594 // pre-inflated and in the monitor cache.
1595 //
1596 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1597 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1598 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1599 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1600 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1601 }
1602
1603 // These things needs to be done while we are still a Java Thread. Make sure that thread
1604 // is in a consistent state, in case GC happens
1605 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1606
1607 if (active_handles() != NULL) {
1608 JNIHandleBlock* block = active_handles();
1609 set_active_handles(NULL);
1610 JNIHandleBlock::release_block(block);
1611 }
1612
1613 if (free_handle_block() != NULL) {
1614 JNIHandleBlock* block = free_handle_block();
1615 set_free_handle_block(NULL);
1616 JNIHandleBlock::release_block(block);
1617 }
1618
1619 // These have to be removed while this is still a valid thread.
1620 remove_stack_guard_pages();
1621
1622 if (UseTLAB) {
1623 tlab().make_parsable(true); // retire TLAB
1624 }
1625
1626 if (jvmti_thread_state() != NULL) {
1627 JvmtiExport::cleanup_thread(this);
1628 }
1629
1630 #ifndef SERIALGC
1631 // We must flush G1-related buffers before removing a thread from
1632 // the list of active threads.
1633 if (UseG1GC) {
1634 flush_barrier_queues();
1635 }
1636 #endif
1637
1638 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1639 Threads::remove(this);
1640 }
1641
1642 #ifndef SERIALGC
1643 // Flush G1-related queues.
1644 void JavaThread::flush_barrier_queues() {
1645 satb_mark_queue().flush();
1646 dirty_card_queue().flush();
1647 }
1648 #endif
1649
1650 void JavaThread::cleanup_failed_attach_current_thread() {
1651 if (get_thread_profiler() != NULL) {
1652 get_thread_profiler()->disengage();
1653 ResourceMark rm;
1654 get_thread_profiler()->print(get_thread_name());
1655 }
1656
1657 if (active_handles() != NULL) {
1658 JNIHandleBlock* block = active_handles();
1659 set_active_handles(NULL);
1660 JNIHandleBlock::release_block(block);
1661 }
1662
1663 if (free_handle_block() != NULL) {
1664 JNIHandleBlock* block = free_handle_block();
1665 set_free_handle_block(NULL);
1666 JNIHandleBlock::release_block(block);
1667 }
1668
1669 // These have to be removed while this is still a valid thread.
1670 remove_stack_guard_pages();
1671
1672 if (UseTLAB) {
1673 tlab().make_parsable(true); // retire TLAB, if any
1674 }
1675
1676 #ifndef SERIALGC
1677 if (UseG1GC) {
1678 flush_barrier_queues();
1679 }
1680 #endif
1681
1682 Threads::remove(this);
1683 delete this;
1684 }
1685
1686
1687
1688
1689 JavaThread* JavaThread::active() {
1690 Thread* thread = ThreadLocalStorage::thread();
1691 assert(thread != NULL, "just checking");
1692 if (thread->is_Java_thread()) {
1693 return (JavaThread*) thread;
1694 } else {
1695 assert(thread->is_VM_thread(), "this must be a vm thread");
1696 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1697 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1698 assert(ret->is_Java_thread(), "must be a Java thread");
1699 return ret;
1700 }
1701 }
1702
1703 bool JavaThread::is_lock_owned(address adr) const {
1704 if (Thread::is_lock_owned(adr)) return true;
1705
1706 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1707 if (chunk->contains(adr)) return true;
1708 }
1709
1710 return false;
1711 }
1712
1713
1714 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1715 chunk->set_next(monitor_chunks());
1716 set_monitor_chunks(chunk);
1717 }
1718
1719 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1720 guarantee(monitor_chunks() != NULL, "must be non empty");
1721 if (monitor_chunks() == chunk) {
1722 set_monitor_chunks(chunk->next());
1723 } else {
1724 MonitorChunk* prev = monitor_chunks();
1725 while (prev->next() != chunk) prev = prev->next();
1726 prev->set_next(chunk->next());
1727 }
1728 }
1729
1730 // JVM support.
1731
1732 // Note: this function shouldn't block if it's called in
1733 // _thread_in_native_trans state (such as from
1734 // check_special_condition_for_native_trans()).
1735 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
1736
1737 if (has_last_Java_frame() && has_async_condition()) {
1738 // If we are at a polling page safepoint (not a poll return)
1739 // then we must defer async exception because live registers
1740 // will be clobbered by the exception path. Poll return is
1741 // ok because the call we a returning from already collides
1742 // with exception handling registers and so there is no issue.
1743 // (The exception handling path kills call result registers but
1744 // this is ok since the exception kills the result anyway).
1745
1746 if (is_at_poll_safepoint()) {
1747 // if the code we are returning to has deoptimized we must defer
1748 // the exception otherwise live registers get clobbered on the
1749 // exception path before deoptimization is able to retrieve them.
1750 //
1751 RegisterMap map(this, false);
1752 frame caller_fr = last_frame().sender(&map);
1753 assert(caller_fr.is_compiled_frame(), "what?");
1754 if (caller_fr.is_deoptimized_frame()) {
1755 if (TraceExceptions) {
1756 ResourceMark rm;
1757 tty->print_cr("deferred async exception at compiled safepoint");
1758 }
1759 return;
1760 }
1761 }
1762 }
1763
1764 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
1765 if (condition == _no_async_condition) {
1766 // Conditions have changed since has_special_runtime_exit_condition()
1767 // was called:
1768 // - if we were here only because of an external suspend request,
1769 // then that was taken care of above (or cancelled) so we are done
1770 // - if we were here because of another async request, then it has
1771 // been cleared between the has_special_runtime_exit_condition()
1772 // and now so again we are done
1773 return;
1774 }
1775
1776 // Check for pending async. exception
1777 if (_pending_async_exception != NULL) {
1778 // Only overwrite an already pending exception, if it is not a threadDeath.
1779 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
1780
1781 // We cannot call Exceptions::_throw(...) here because we cannot block
1782 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1783
1784 if (TraceExceptions) {
1785 ResourceMark rm;
1786 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
1787 if (has_last_Java_frame() ) {
1788 frame f = last_frame();
1789 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
1790 }
1791 tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1792 }
1793 _pending_async_exception = NULL;
1794 clear_has_async_exception();
1795 }
1796 }
1797
1798 if (check_unsafe_error &&
1799 condition == _async_unsafe_access_error && !has_pending_exception()) {
1800 condition = _no_async_condition; // done
1801 switch (thread_state()) {
1802 case _thread_in_vm:
1803 {
1804 JavaThread* THREAD = this;
1805 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1806 }
1807 case _thread_in_native:
1808 {
1809 ThreadInVMfromNative tiv(this);
1810 JavaThread* THREAD = this;
1811 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1812 }
1813 case _thread_in_Java:
1814 {
1815 ThreadInVMfromJava tiv(this);
1816 JavaThread* THREAD = this;
1817 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1818 }
1819 default:
1820 ShouldNotReachHere();
1821 }
1822 }
1823
1824 assert(condition == _no_async_condition || has_pending_exception() ||
1825 (!check_unsafe_error && condition == _async_unsafe_access_error),
1826 "must have handled the async condition, if no exception");
1827 }
1828
1829 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1830 //
1831 // Check for pending external suspend. Internal suspend requests do
1832 // not use handle_special_runtime_exit_condition().
1833 // If JNIEnv proxies are allowed, don't self-suspend if the target
1834 // thread is not the current thread. In older versions of jdbx, jdbx
1835 // threads could call into the VM with another thread's JNIEnv so we
1836 // can be here operating on behalf of a suspended thread (4432884).
1837 bool do_self_suspend = is_external_suspend_with_lock();
1838 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
1839 //
1840 // Because thread is external suspended the safepoint code will count
1841 // thread as at a safepoint. This can be odd because we can be here
1842 // as _thread_in_Java which would normally transition to _thread_blocked
1843 // at a safepoint. We would like to mark the thread as _thread_blocked
1844 // before calling java_suspend_self like all other callers of it but
1845 // we must then observe proper safepoint protocol. (We can't leave
1846 // _thread_blocked with a safepoint in progress). However we can be
1847 // here as _thread_in_native_trans so we can't use a normal transition
1848 // constructor/destructor pair because they assert on that type of
1849 // transition. We could do something like:
1850 //
1851 // JavaThreadState state = thread_state();
1852 // set_thread_state(_thread_in_vm);
1853 // {
1854 // ThreadBlockInVM tbivm(this);
1855 // java_suspend_self()
1856 // }
1857 // set_thread_state(_thread_in_vm_trans);
1858 // if (safepoint) block;
1859 // set_thread_state(state);
1860 //
1861 // but that is pretty messy. Instead we just go with the way the
1862 // code has worked before and note that this is the only path to
1863 // java_suspend_self that doesn't put the thread in _thread_blocked
1864 // mode.
1865
1866 frame_anchor()->make_walkable(this);
1867 java_suspend_self();
1868
1869 // We might be here for reasons in addition to the self-suspend request
1870 // so check for other async requests.
1871 }
1872
1873 if (check_asyncs) {
1874 check_and_handle_async_exceptions();
1875 }
1876 }
1877
1878 void JavaThread::send_thread_stop(oop java_throwable) {
1879 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
1880 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
1881 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1882
1883 // Do not throw asynchronous exceptions against the compiler thread
1884 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1885 if (is_Compiler_thread()) return;
1886
1887 // This is a change from JDK 1.1, but JDK 1.2 will also do it:
1888 if (java_throwable->is_a(SystemDictionary::ThreadDeath_klass())) {
1889 java_lang_Thread::set_stillborn(threadObj());
1890 }
1891
1892 {
1893 // Actually throw the Throwable against the target Thread - however
1894 // only if there is no thread death exception installed already.
1895 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
1896 // If the topmost frame is a runtime stub, then we are calling into
1897 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1898 // must deoptimize the caller before continuing, as the compiled exception handler table
1899 // may not be valid
1900 if (has_last_Java_frame()) {
1901 frame f = last_frame();
1902 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1903 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
1904 RegisterMap reg_map(this, UseBiasedLocking);
1905 frame compiled_frame = f.sender(®_map);
1906 if (compiled_frame.can_be_deoptimized()) {
1907 Deoptimization::deoptimize(this, compiled_frame, ®_map);
1908 }
1909 }
1910 }
1911
1912 // Set async. pending exception in thread.
1913 set_pending_async_exception(java_throwable);
1914
1915 if (TraceExceptions) {
1916 ResourceMark rm;
1917 tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1918 }
1919 // for AbortVMOnException flag
1920 NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name()));
1921 }
1922 }
1923
1924
1925 // Interrupt thread so it will wake up from a potential wait()
1926 Thread::interrupt(this);
1927 }
1928
1929 // External suspension mechanism.
1930 //
1931 // Tell the VM to suspend a thread when ever it knows that it does not hold on
1932 // to any VM_locks and it is at a transition
1933 // Self-suspension will happen on the transition out of the vm.
1934 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
1935 //
1936 // Guarantees on return:
1937 // + Target thread will not execute any new bytecode (that's why we need to
1938 // force a safepoint)
1939 // + Target thread will not enter any new monitors
1940 //
1941 void JavaThread::java_suspend() {
1942 { MutexLocker mu(Threads_lock);
1943 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
1944 return;
1945 }
1946 }
1947
1948 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1949 if (!is_external_suspend()) {
1950 // a racing resume has cancelled us; bail out now
1951 return;
1952 }
1953
1954 // suspend is done
1955 uint32_t debug_bits = 0;
1956 // Warning: is_ext_suspend_completed() may temporarily drop the
1957 // SR_lock to allow the thread to reach a stable thread state if
1958 // it is currently in a transient thread state.
1959 if (is_ext_suspend_completed(false /* !called_by_wait */,
1960 SuspendRetryDelay, &debug_bits) ) {
1961 return;
1962 }
1963 }
1964
1965 VM_ForceSafepoint vm_suspend;
1966 VMThread::execute(&vm_suspend);
1967 }
1968
1969 // Part II of external suspension.
1970 // A JavaThread self suspends when it detects a pending external suspend
1971 // request. This is usually on transitions. It is also done in places
1972 // where continuing to the next transition would surprise the caller,
1973 // e.g., monitor entry.
1974 //
1975 // Returns the number of times that the thread self-suspended.
1976 //
1977 // Note: DO NOT call java_suspend_self() when you just want to block current
1978 // thread. java_suspend_self() is the second stage of cooperative
1979 // suspension for external suspend requests and should only be used
1980 // to complete an external suspend request.
1981 //
1982 int JavaThread::java_suspend_self() {
1983 int ret = 0;
1984
1985 // we are in the process of exiting so don't suspend
1986 if (is_exiting()) {
1987 clear_external_suspend();
1988 return ret;
1989 }
1990
1991 assert(_anchor.walkable() ||
1992 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
1993 "must have walkable stack");
1994
1995 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1996
1997 assert(!this->is_ext_suspended(),
1998 "a thread trying to self-suspend should not already be suspended");
1999
2000 if (this->is_suspend_equivalent()) {
2001 // If we are self-suspending as a result of the lifting of a
2002 // suspend equivalent condition, then the suspend_equivalent
2003 // flag is not cleared until we set the ext_suspended flag so
2004 // that wait_for_ext_suspend_completion() returns consistent
2005 // results.
2006 this->clear_suspend_equivalent();
2007 }
2008
2009 // A racing resume may have cancelled us before we grabbed SR_lock
2010 // above. Or another external suspend request could be waiting for us
2011 // by the time we return from SR_lock()->wait(). The thread
2012 // that requested the suspension may already be trying to walk our
2013 // stack and if we return now, we can change the stack out from under
2014 // it. This would be a "bad thing (TM)" and cause the stack walker
2015 // to crash. We stay self-suspended until there are no more pending
2016 // external suspend requests.
2017 while (is_external_suspend()) {
2018 ret++;
2019 this->set_ext_suspended();
2020
2021 // _ext_suspended flag is cleared by java_resume()
2022 while (is_ext_suspended()) {
2023 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2024 }
2025 }
2026
2027 return ret;
2028 }
2029
2030 #ifdef ASSERT
2031 // verify the JavaThread has not yet been published in the Threads::list, and
2032 // hence doesn't need protection from concurrent access at this stage
2033 void JavaThread::verify_not_published() {
2034 if (!Threads_lock->owned_by_self()) {
2035 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2036 assert( !Threads::includes(this),
2037 "java thread shouldn't have been published yet!");
2038 }
2039 else {
2040 assert( !Threads::includes(this),
2041 "java thread shouldn't have been published yet!");
2042 }
2043 }
2044 #endif
2045
2046 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2047 // progress or when _suspend_flags is non-zero.
2048 // Current thread needs to self-suspend if there is a suspend request and/or
2049 // block if a safepoint is in progress.
2050 // Async exception ISN'T checked.
2051 // Note only the ThreadInVMfromNative transition can call this function
2052 // directly and when thread state is _thread_in_native_trans
2053 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2054 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2055
2056 JavaThread *curJT = JavaThread::current();
2057 bool do_self_suspend = thread->is_external_suspend();
2058
2059 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2060
2061 // If JNIEnv proxies are allowed, don't self-suspend if the target
2062 // thread is not the current thread. In older versions of jdbx, jdbx
2063 // threads could call into the VM with another thread's JNIEnv so we
2064 // can be here operating on behalf of a suspended thread (4432884).
2065 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2066 JavaThreadState state = thread->thread_state();
2067
2068 // We mark this thread_blocked state as a suspend-equivalent so
2069 // that a caller to is_ext_suspend_completed() won't be confused.
2070 // The suspend-equivalent state is cleared by java_suspend_self().
2071 thread->set_suspend_equivalent();
2072
2073 // If the safepoint code sees the _thread_in_native_trans state, it will
2074 // wait until the thread changes to other thread state. There is no
2075 // guarantee on how soon we can obtain the SR_lock and complete the
2076 // self-suspend request. It would be a bad idea to let safepoint wait for
2077 // too long. Temporarily change the state to _thread_blocked to
2078 // let the VM thread know that this thread is ready for GC. The problem
2079 // of changing thread state is that safepoint could happen just after
2080 // java_suspend_self() returns after being resumed, and VM thread will
2081 // see the _thread_blocked state. We must check for safepoint
2082 // after restoring the state and make sure we won't leave while a safepoint
2083 // is in progress.
2084 thread->set_thread_state(_thread_blocked);
2085 thread->java_suspend_self();
2086 thread->set_thread_state(state);
2087 // Make sure new state is seen by VM thread
2088 if (os::is_MP()) {
2089 if (UseMembar) {
2090 // Force a fence between the write above and read below
2091 OrderAccess::fence();
2092 } else {
2093 // Must use this rather than serialization page in particular on Windows
2094 InterfaceSupport::serialize_memory(thread);
2095 }
2096 }
2097 }
2098
2099 if (SafepointSynchronize::do_call_back()) {
2100 // If we are safepointing, then block the caller which may not be
2101 // the same as the target thread (see above).
2102 SafepointSynchronize::block(curJT);
2103 }
2104
2105 if (thread->is_deopt_suspend()) {
2106 thread->clear_deopt_suspend();
2107 RegisterMap map(thread, false);
2108 frame f = thread->last_frame();
2109 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2110 f = f.sender(&map);
2111 }
2112 if (f.id() == thread->must_deopt_id()) {
2113 thread->clear_must_deopt_id();
2114 f.deoptimize(thread);
2115 } else {
2116 fatal("missed deoptimization!");
2117 }
2118 }
2119 }
2120
2121 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2122 // progress or when _suspend_flags is non-zero.
2123 // Current thread needs to self-suspend if there is a suspend request and/or
2124 // block if a safepoint is in progress.
2125 // Also check for pending async exception (not including unsafe access error).
2126 // Note only the native==>VM/Java barriers can call this function and when
2127 // thread state is _thread_in_native_trans.
2128 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2129 check_safepoint_and_suspend_for_native_trans(thread);
2130
2131 if (thread->has_async_exception()) {
2132 // We are in _thread_in_native_trans state, don't handle unsafe
2133 // access error since that may block.
2134 thread->check_and_handle_async_exceptions(false);
2135 }
2136 }
2137
2138 // We need to guarantee the Threads_lock here, since resumes are not
2139 // allowed during safepoint synchronization
2140 // Can only resume from an external suspension
2141 void JavaThread::java_resume() {
2142 assert_locked_or_safepoint(Threads_lock);
2143
2144 // Sanity check: thread is gone, has started exiting or the thread
2145 // was not externally suspended.
2146 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2147 return;
2148 }
2149
2150 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2151
2152 clear_external_suspend();
2153
2154 if (is_ext_suspended()) {
2155 clear_ext_suspended();
2156 SR_lock()->notify_all();
2157 }
2158 }
2159
2160 void JavaThread::create_stack_guard_pages() {
2161 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2162 address low_addr = stack_base() - stack_size();
2163 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2164
2165 int allocate = os::allocate_stack_guard_pages();
2166 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2167
2168 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
2169 warning("Attempt to allocate stack guard pages failed.");
2170 return;
2171 }
2172
2173 if (os::guard_memory((char *) low_addr, len)) {
2174 _stack_guard_state = stack_guard_enabled;
2175 } else {
2176 warning("Attempt to protect stack guard pages failed.");
2177 if (os::uncommit_memory((char *) low_addr, len)) {
2178 warning("Attempt to deallocate stack guard pages failed.");
2179 }
2180 }
2181 }
2182
2183 void JavaThread::remove_stack_guard_pages() {
2184 if (_stack_guard_state == stack_guard_unused) return;
2185 address low_addr = stack_base() - stack_size();
2186 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2187
2188 if (os::allocate_stack_guard_pages()) {
2189 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2190 _stack_guard_state = stack_guard_unused;
2191 } else {
2192 warning("Attempt to deallocate stack guard pages failed.");
2193 }
2194 } else {
2195 if (_stack_guard_state == stack_guard_unused) return;
2196 if (os::unguard_memory((char *) low_addr, len)) {
2197 _stack_guard_state = stack_guard_unused;
2198 } else {
2199 warning("Attempt to unprotect stack guard pages failed.");
2200 }
2201 }
2202 }
2203
2204 void JavaThread::enable_stack_yellow_zone() {
2205 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2206 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2207
2208 // The base notation is from the stacks point of view, growing downward.
2209 // We need to adjust it to work correctly with guard_memory()
2210 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2211
2212 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2213 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2214
2215 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2216 _stack_guard_state = stack_guard_enabled;
2217 } else {
2218 warning("Attempt to guard stack yellow zone failed.");
2219 }
2220 enable_register_stack_guard();
2221 }
2222
2223 void JavaThread::disable_stack_yellow_zone() {
2224 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2225 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2226
2227 // Simply return if called for a thread that does not use guard pages.
2228 if (_stack_guard_state == stack_guard_unused) return;
2229
2230 // The base notation is from the stacks point of view, growing downward.
2231 // We need to adjust it to work correctly with guard_memory()
2232 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2233
2234 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2235 _stack_guard_state = stack_guard_yellow_disabled;
2236 } else {
2237 warning("Attempt to unguard stack yellow zone failed.");
2238 }
2239 disable_register_stack_guard();
2240 }
2241
2242 void JavaThread::enable_stack_red_zone() {
2243 // The base notation is from the stacks point of view, growing downward.
2244 // We need to adjust it to work correctly with guard_memory()
2245 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2246 address base = stack_red_zone_base() - stack_red_zone_size();
2247
2248 guarantee(base < stack_base(),"Error calculating stack red zone");
2249 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2250
2251 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2252 warning("Attempt to guard stack red zone failed.");
2253 }
2254 }
2255
2256 void JavaThread::disable_stack_red_zone() {
2257 // The base notation is from the stacks point of view, growing downward.
2258 // We need to adjust it to work correctly with guard_memory()
2259 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2260 address base = stack_red_zone_base() - stack_red_zone_size();
2261 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2262 warning("Attempt to unguard stack red zone failed.");
2263 }
2264 }
2265
2266 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2267 // ignore is there is no stack
2268 if (!has_last_Java_frame()) return;
2269 // traverse the stack frames. Starts from top frame.
2270 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2271 frame* fr = fst.current();
2272 f(fr, fst.register_map());
2273 }
2274 }
2275
2276
2277 #ifndef PRODUCT
2278 // Deoptimization
2279 // Function for testing deoptimization
2280 void JavaThread::deoptimize() {
2281 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2282 StackFrameStream fst(this, UseBiasedLocking);
2283 bool deopt = false; // Dump stack only if a deopt actually happens.
2284 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2285 // Iterate over all frames in the thread and deoptimize
2286 for(; !fst.is_done(); fst.next()) {
2287 if(fst.current()->can_be_deoptimized()) {
2288
2289 if (only_at) {
2290 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2291 // consists of comma or carriage return separated numbers so
2292 // search for the current bci in that string.
2293 address pc = fst.current()->pc();
2294 nmethod* nm = (nmethod*) fst.current()->cb();
2295 ScopeDesc* sd = nm->scope_desc_at( pc);
2296 char buffer[8];
2297 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2298 size_t len = strlen(buffer);
2299 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2300 while (found != NULL) {
2301 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2302 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2303 // Check that the bci found is bracketed by terminators.
2304 break;
2305 }
2306 found = strstr(found + 1, buffer);
2307 }
2308 if (!found) {
2309 continue;
2310 }
2311 }
2312
2313 if (DebugDeoptimization && !deopt) {
2314 deopt = true; // One-time only print before deopt
2315 tty->print_cr("[BEFORE Deoptimization]");
2316 trace_frames();
2317 trace_stack();
2318 }
2319 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2320 }
2321 }
2322
2323 if (DebugDeoptimization && deopt) {
2324 tty->print_cr("[AFTER Deoptimization]");
2325 trace_frames();
2326 }
2327 }
2328
2329
2330 // Make zombies
2331 void JavaThread::make_zombies() {
2332 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2333 if (fst.current()->can_be_deoptimized()) {
2334 // it is a Java nmethod
2335 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2336 nm->make_not_entrant();
2337 }
2338 }
2339 }
2340 #endif // PRODUCT
2341
2342
2343 void JavaThread::deoptimized_wrt_marked_nmethods() {
2344 if (!has_last_Java_frame()) return;
2345 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2346 StackFrameStream fst(this, UseBiasedLocking);
2347 for(; !fst.is_done(); fst.next()) {
2348 if (fst.current()->should_be_deoptimized()) {
2349 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2350 }
2351 }
2352 }
2353
2354
2355 // GC support
2356 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2357
2358 void JavaThread::gc_epilogue() {
2359 frames_do(frame_gc_epilogue);
2360 }
2361
2362
2363 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2364
2365 void JavaThread::gc_prologue() {
2366 frames_do(frame_gc_prologue);
2367 }
2368
2369 // If the caller is a NamedThread, then remember, in the current scope,
2370 // the given JavaThread in its _processed_thread field.
2371 class RememberProcessedThread: public StackObj {
2372 NamedThread* _cur_thr;
2373 public:
2374 RememberProcessedThread(JavaThread* jthr) {
2375 Thread* thread = Thread::current();
2376 if (thread->is_Named_thread()) {
2377 _cur_thr = (NamedThread *)thread;
2378 _cur_thr->set_processed_thread(jthr);
2379 } else {
2380 _cur_thr = NULL;
2381 }
2382 }
2383
2384 ~RememberProcessedThread() {
2385 if (_cur_thr) {
2386 _cur_thr->set_processed_thread(NULL);
2387 }
2388 }
2389 };
2390
2391 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2392 // Verify that the deferred card marks have been flushed.
2393 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2394
2395 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2396 // since there may be more than one thread using each ThreadProfiler.
2397
2398 // Traverse the GCHandles
2399 Thread::oops_do(f, cf);
2400
2401 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2402 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2403
2404 if (has_last_Java_frame()) {
2405 // Record JavaThread to GC thread
2406 RememberProcessedThread rpt(this);
2407
2408 // Traverse the privileged stack
2409 if (_privileged_stack_top != NULL) {
2410 _privileged_stack_top->oops_do(f);
2411 }
2412
2413 // traverse the registered growable array
2414 if (_array_for_gc != NULL) {
2415 for (int index = 0; index < _array_for_gc->length(); index++) {
2416 f->do_oop(_array_for_gc->adr_at(index));
2417 }
2418 }
2419
2420 // Traverse the monitor chunks
2421 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2422 chunk->oops_do(f);
2423 }
2424
2425 // Traverse the execution stack
2426 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2427 fst.current()->oops_do(f, cf, fst.register_map());
2428 }
2429 }
2430
2431 // callee_target is never live across a gc point so NULL it here should
2432 // it still contain a methdOop.
2433
2434 set_callee_target(NULL);
2435
2436 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2437 // If we have deferred set_locals there might be oops waiting to be
2438 // written
2439 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2440 if (list != NULL) {
2441 for (int i = 0; i < list->length(); i++) {
2442 list->at(i)->oops_do(f);
2443 }
2444 }
2445
2446 // Traverse instance variables at the end since the GC may be moving things
2447 // around using this function
2448 f->do_oop((oop*) &_threadObj);
2449 f->do_oop((oop*) &_vm_result);
2450 f->do_oop((oop*) &_vm_result_2);
2451 f->do_oop((oop*) &_exception_oop);
2452 f->do_oop((oop*) &_pending_async_exception);
2453
2454 if (jvmti_thread_state() != NULL) {
2455 jvmti_thread_state()->oops_do(f);
2456 }
2457 }
2458
2459 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2460 Thread::nmethods_do(cf); // (super method is a no-op)
2461
2462 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2463 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2464
2465 if (has_last_Java_frame()) {
2466 // Traverse the execution stack
2467 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2468 fst.current()->nmethods_do(cf);
2469 }
2470 }
2471 }
2472
2473 // Printing
2474 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2475 switch (_thread_state) {
2476 case _thread_uninitialized: return "_thread_uninitialized";
2477 case _thread_new: return "_thread_new";
2478 case _thread_new_trans: return "_thread_new_trans";
2479 case _thread_in_native: return "_thread_in_native";
2480 case _thread_in_native_trans: return "_thread_in_native_trans";
2481 case _thread_in_vm: return "_thread_in_vm";
2482 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2483 case _thread_in_Java: return "_thread_in_Java";
2484 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2485 case _thread_blocked: return "_thread_blocked";
2486 case _thread_blocked_trans: return "_thread_blocked_trans";
2487 default: return "unknown thread state";
2488 }
2489 }
2490
2491 #ifndef PRODUCT
2492 void JavaThread::print_thread_state_on(outputStream *st) const {
2493 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2494 };
2495 void JavaThread::print_thread_state() const {
2496 print_thread_state_on(tty);
2497 };
2498 #endif // PRODUCT
2499
2500 // Called by Threads::print() for VM_PrintThreads operation
2501 void JavaThread::print_on(outputStream *st) const {
2502 st->print("\"%s\" ", get_thread_name());
2503 oop thread_oop = threadObj();
2504 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2505 Thread::print_on(st);
2506 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2507 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2508 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2509 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2510 }
2511 #ifndef PRODUCT
2512 print_thread_state_on(st);
2513 _safepoint_state->print_on(st);
2514 #endif // PRODUCT
2515 }
2516
2517 // Called by fatal error handler. The difference between this and
2518 // JavaThread::print() is that we can't grab lock or allocate memory.
2519 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2520 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2521 oop thread_obj = threadObj();
2522 if (thread_obj != NULL) {
2523 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2524 }
2525 st->print(" [");
2526 st->print("%s", _get_thread_state_name(_thread_state));
2527 if (osthread()) {
2528 st->print(", id=%d", osthread()->thread_id());
2529 }
2530 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2531 _stack_base - _stack_size, _stack_base);
2532 st->print("]");
2533 return;
2534 }
2535
2536 // Verification
2537
2538 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2539
2540 void JavaThread::verify() {
2541 // Verify oops in the thread.
2542 oops_do(&VerifyOopClosure::verify_oop, NULL);
2543
2544 // Verify the stack frames.
2545 frames_do(frame_verify);
2546 }
2547
2548 // CR 6300358 (sub-CR 2137150)
2549 // Most callers of this method assume that it can't return NULL but a
2550 // thread may not have a name whilst it is in the process of attaching to
2551 // the VM - see CR 6412693, and there are places where a JavaThread can be
2552 // seen prior to having it's threadObj set (eg JNI attaching threads and
2553 // if vm exit occurs during initialization). These cases can all be accounted
2554 // for such that this method never returns NULL.
2555 const char* JavaThread::get_thread_name() const {
2556 #ifdef ASSERT
2557 // early safepoints can hit while current thread does not yet have TLS
2558 if (!SafepointSynchronize::is_at_safepoint()) {
2559 Thread *cur = Thread::current();
2560 if (!(cur->is_Java_thread() && cur == this)) {
2561 // Current JavaThreads are allowed to get their own name without
2562 // the Threads_lock.
2563 assert_locked_or_safepoint(Threads_lock);
2564 }
2565 }
2566 #endif // ASSERT
2567 return get_thread_name_string();
2568 }
2569
2570 // Returns a non-NULL representation of this thread's name, or a suitable
2571 // descriptive string if there is no set name
2572 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2573 const char* name_str;
2574 oop thread_obj = threadObj();
2575 if (thread_obj != NULL) {
2576 typeArrayOop name = java_lang_Thread::name(thread_obj);
2577 if (name != NULL) {
2578 if (buf == NULL) {
2579 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2580 }
2581 else {
2582 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2583 }
2584 }
2585 else if (is_attaching()) { // workaround for 6412693 - see 6404306
2586 name_str = "<no-name - thread is attaching>";
2587 }
2588 else {
2589 name_str = Thread::name();
2590 }
2591 }
2592 else {
2593 name_str = Thread::name();
2594 }
2595 assert(name_str != NULL, "unexpected NULL thread name");
2596 return name_str;
2597 }
2598
2599
2600 const char* JavaThread::get_threadgroup_name() const {
2601 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2602 oop thread_obj = threadObj();
2603 if (thread_obj != NULL) {
2604 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2605 if (thread_group != NULL) {
2606 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2607 // ThreadGroup.name can be null
2608 if (name != NULL) {
2609 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2610 return str;
2611 }
2612 }
2613 }
2614 return NULL;
2615 }
2616
2617 const char* JavaThread::get_parent_name() const {
2618 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2619 oop thread_obj = threadObj();
2620 if (thread_obj != NULL) {
2621 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2622 if (thread_group != NULL) {
2623 oop parent = java_lang_ThreadGroup::parent(thread_group);
2624 if (parent != NULL) {
2625 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2626 // ThreadGroup.name can be null
2627 if (name != NULL) {
2628 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2629 return str;
2630 }
2631 }
2632 }
2633 }
2634 return NULL;
2635 }
2636
2637 ThreadPriority JavaThread::java_priority() const {
2638 oop thr_oop = threadObj();
2639 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2640 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2641 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2642 return priority;
2643 }
2644
2645 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2646
2647 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2648 // Link Java Thread object <-> C++ Thread
2649
2650 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2651 // and put it into a new Handle. The Handle "thread_oop" can then
2652 // be used to pass the C++ thread object to other methods.
2653
2654 // Set the Java level thread object (jthread) field of the
2655 // new thread (a JavaThread *) to C++ thread object using the
2656 // "thread_oop" handle.
2657
2658 // Set the thread field (a JavaThread *) of the
2659 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2660
2661 Handle thread_oop(Thread::current(),
2662 JNIHandles::resolve_non_null(jni_thread));
2663 assert(instanceKlass::cast(thread_oop->klass())->is_linked(),
2664 "must be initialized");
2665 set_threadObj(thread_oop());
2666 java_lang_Thread::set_thread(thread_oop(), this);
2667
2668 if (prio == NoPriority) {
2669 prio = java_lang_Thread::priority(thread_oop());
2670 assert(prio != NoPriority, "A valid priority should be present");
2671 }
2672
2673 // Push the Java priority down to the native thread; needs Threads_lock
2674 Thread::set_priority(this, prio);
2675
2676 // Add the new thread to the Threads list and set it in motion.
2677 // We must have threads lock in order to call Threads::add.
2678 // It is crucial that we do not block before the thread is
2679 // added to the Threads list for if a GC happens, then the java_thread oop
2680 // will not be visited by GC.
2681 Threads::add(this);
2682 }
2683
2684 oop JavaThread::current_park_blocker() {
2685 // Support for JSR-166 locks
2686 oop thread_oop = threadObj();
2687 if (thread_oop != NULL &&
2688 JDK_Version::current().supports_thread_park_blocker()) {
2689 return java_lang_Thread::park_blocker(thread_oop);
2690 }
2691 return NULL;
2692 }
2693
2694
2695 void JavaThread::print_stack_on(outputStream* st) {
2696 if (!has_last_Java_frame()) return;
2697 ResourceMark rm;
2698 HandleMark hm;
2699
2700 RegisterMap reg_map(this);
2701 vframe* start_vf = last_java_vframe(®_map);
2702 int count = 0;
2703 for (vframe* f = start_vf; f; f = f->sender() ) {
2704 if (f->is_java_frame()) {
2705 javaVFrame* jvf = javaVFrame::cast(f);
2706 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2707
2708 // Print out lock information
2709 if (JavaMonitorsInStackTrace) {
2710 jvf->print_lock_info_on(st, count);
2711 }
2712 } else {
2713 // Ignore non-Java frames
2714 }
2715
2716 // Bail-out case for too deep stacks
2717 count++;
2718 if (MaxJavaStackTraceDepth == count) return;
2719 }
2720 }
2721
2722
2723 // JVMTI PopFrame support
2724 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2725 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2726 if (in_bytes(size_in_bytes) != 0) {
2727 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes));
2728 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2729 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2730 }
2731 }
2732
2733 void* JavaThread::popframe_preserved_args() {
2734 return _popframe_preserved_args;
2735 }
2736
2737 ByteSize JavaThread::popframe_preserved_args_size() {
2738 return in_ByteSize(_popframe_preserved_args_size);
2739 }
2740
2741 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2742 int sz = in_bytes(popframe_preserved_args_size());
2743 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2744 return in_WordSize(sz / wordSize);
2745 }
2746
2747 void JavaThread::popframe_free_preserved_args() {
2748 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2749 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args);
2750 _popframe_preserved_args = NULL;
2751 _popframe_preserved_args_size = 0;
2752 }
2753
2754 #ifndef PRODUCT
2755
2756 void JavaThread::trace_frames() {
2757 tty->print_cr("[Describe stack]");
2758 int frame_no = 1;
2759 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2760 tty->print(" %d. ", frame_no++);
2761 fst.current()->print_value_on(tty,this);
2762 tty->cr();
2763 }
2764 }
2765
2766
2767 void JavaThread::trace_stack_from(vframe* start_vf) {
2768 ResourceMark rm;
2769 int vframe_no = 1;
2770 for (vframe* f = start_vf; f; f = f->sender() ) {
2771 if (f->is_java_frame()) {
2772 javaVFrame::cast(f)->print_activation(vframe_no++);
2773 } else {
2774 f->print();
2775 }
2776 if (vframe_no > StackPrintLimit) {
2777 tty->print_cr("...<more frames>...");
2778 return;
2779 }
2780 }
2781 }
2782
2783
2784 void JavaThread::trace_stack() {
2785 if (!has_last_Java_frame()) return;
2786 ResourceMark rm;
2787 HandleMark hm;
2788 RegisterMap reg_map(this);
2789 trace_stack_from(last_java_vframe(®_map));
2790 }
2791
2792
2793 #endif // PRODUCT
2794
2795
2796 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2797 assert(reg_map != NULL, "a map must be given");
2798 frame f = last_frame();
2799 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
2800 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2801 }
2802 return NULL;
2803 }
2804
2805
2806 klassOop JavaThread::security_get_caller_class(int depth) {
2807 vframeStream vfst(this);
2808 vfst.security_get_caller_frame(depth);
2809 if (!vfst.at_end()) {
2810 return vfst.method()->method_holder();
2811 }
2812 return NULL;
2813 }
2814
2815 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
2816 assert(thread->is_Compiler_thread(), "must be compiler thread");
2817 CompileBroker::compiler_thread_loop();
2818 }
2819
2820 // Create a CompilerThread
2821 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
2822 : JavaThread(&compiler_thread_entry) {
2823 _env = NULL;
2824 _log = NULL;
2825 _task = NULL;
2826 _queue = queue;
2827 _counters = counters;
2828 _buffer_blob = NULL;
2829
2830 #ifndef PRODUCT
2831 _ideal_graph_printer = NULL;
2832 #endif
2833 }
2834
2835
2836 // ======= Threads ========
2837
2838 // The Threads class links together all active threads, and provides
2839 // operations over all threads. It is protected by its own Mutex
2840 // lock, which is also used in other contexts to protect thread
2841 // operations from having the thread being operated on from exiting
2842 // and going away unexpectedly (e.g., safepoint synchronization)
2843
2844 JavaThread* Threads::_thread_list = NULL;
2845 int Threads::_number_of_threads = 0;
2846 int Threads::_number_of_non_daemon_threads = 0;
2847 int Threads::_return_code = 0;
2848 size_t JavaThread::_stack_size_at_create = 0;
2849
2850 // All JavaThreads
2851 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
2852
2853 void os_stream();
2854
2855 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
2856 void Threads::threads_do(ThreadClosure* tc) {
2857 assert_locked_or_safepoint(Threads_lock);
2858 // ALL_JAVA_THREADS iterates through all JavaThreads
2859 ALL_JAVA_THREADS(p) {
2860 tc->do_thread(p);
2861 }
2862 // Someday we could have a table or list of all non-JavaThreads.
2863 // For now, just manually iterate through them.
2864 tc->do_thread(VMThread::vm_thread());
2865 Universe::heap()->gc_threads_do(tc);
2866 WatcherThread *wt = WatcherThread::watcher_thread();
2867 // Strictly speaking, the following NULL check isn't sufficient to make sure
2868 // the data for WatcherThread is still valid upon being examined. However,
2869 // considering that WatchThread terminates when the VM is on the way to
2870 // exit at safepoint, the chance of the above is extremely small. The right
2871 // way to prevent termination of WatcherThread would be to acquire
2872 // Terminator_lock, but we can't do that without violating the lock rank
2873 // checking in some cases.
2874 if (wt != NULL)
2875 tc->do_thread(wt);
2876
2877 // If CompilerThreads ever become non-JavaThreads, add them here
2878 }
2879
2880 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2881
2882 extern void JDK_Version_init();
2883
2884 // Check version
2885 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2886
2887 // Initialize the output stream module
2888 ostream_init();
2889
2890 // Process java launcher properties.
2891 Arguments::process_sun_java_launcher_properties(args);
2892
2893 // Initialize the os module before using TLS
2894 os::init();
2895
2896 // Initialize system properties.
2897 Arguments::init_system_properties();
2898
2899 // So that JDK version can be used as a discrimintor when parsing arguments
2900 JDK_Version_init();
2901
2902 // Parse arguments
2903 jint parse_result = Arguments::parse(args);
2904 if (parse_result != JNI_OK) return parse_result;
2905
2906 if (PauseAtStartup) {
2907 os::pause();
2908 }
2909
2910 HS_DTRACE_PROBE(hotspot, vm__init__begin);
2911
2912 // Record VM creation timing statistics
2913 TraceVmCreationTime create_vm_timer;
2914 create_vm_timer.start();
2915
2916 // Timing (must come after argument parsing)
2917 TraceTime timer("Create VM", TraceStartupTime);
2918
2919 // Initialize the os module after parsing the args
2920 jint os_init_2_result = os::init_2();
2921 if (os_init_2_result != JNI_OK) return os_init_2_result;
2922
2923 // Initialize output stream logging
2924 ostream_init_log();
2925
2926 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2927 // Must be before create_vm_init_agents()
2928 if (Arguments::init_libraries_at_startup()) {
2929 convert_vm_init_libraries_to_agents();
2930 }
2931
2932 // Launch -agentlib/-agentpath and converted -Xrun agents
2933 if (Arguments::init_agents_at_startup()) {
2934 create_vm_init_agents();
2935 }
2936
2937 // Initialize Threads state
2938 _thread_list = NULL;
2939 _number_of_threads = 0;
2940 _number_of_non_daemon_threads = 0;
2941
2942 // Initialize TLS
2943 ThreadLocalStorage::init();
2944
2945 // Initialize global data structures and create system classes in heap
2946 vm_init_globals();
2947
2948 // Attach the main thread to this os thread
2949 JavaThread* main_thread = new JavaThread();
2950 main_thread->set_thread_state(_thread_in_vm);
2951 // must do this before set_active_handles and initialize_thread_local_storage
2952 // Note: on solaris initialize_thread_local_storage() will (indirectly)
2953 // change the stack size recorded here to one based on the java thread
2954 // stacksize. This adjusted size is what is used to figure the placement
2955 // of the guard pages.
2956 main_thread->record_stack_base_and_size();
2957 main_thread->initialize_thread_local_storage();
2958
2959 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2960
2961 if (!main_thread->set_as_starting_thread()) {
2962 vm_shutdown_during_initialization(
2963 "Failed necessary internal allocation. Out of swap space");
2964 delete main_thread;
2965 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2966 return JNI_ENOMEM;
2967 }
2968
2969 // Enable guard page *after* os::create_main_thread(), otherwise it would
2970 // crash Linux VM, see notes in os_linux.cpp.
2971 main_thread->create_stack_guard_pages();
2972
2973 // Initialize Java-Leve synchronization subsystem
2974 ObjectSynchronizer::Initialize() ;
2975
2976 // Initialize global modules
2977 jint status = init_globals();
2978 if (status != JNI_OK) {
2979 delete main_thread;
2980 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2981 return status;
2982 }
2983
2984 // Should be done after the heap is fully created
2985 main_thread->cache_global_variables();
2986
2987 HandleMark hm;
2988
2989 { MutexLocker mu(Threads_lock);
2990 Threads::add(main_thread);
2991 }
2992
2993 // Any JVMTI raw monitors entered in onload will transition into
2994 // real raw monitor. VM is setup enough here for raw monitor enter.
2995 JvmtiExport::transition_pending_onload_raw_monitors();
2996
2997 if (VerifyBeforeGC &&
2998 Universe::heap()->total_collections() >= VerifyGCStartAt) {
2999 Universe::heap()->prepare_for_verify();
3000 Universe::verify(); // make sure we're starting with a clean slate
3001 }
3002
3003 // Create the VMThread
3004 { TraceTime timer("Start VMThread", TraceStartupTime);
3005 VMThread::create();
3006 Thread* vmthread = VMThread::vm_thread();
3007
3008 if (!os::create_thread(vmthread, os::vm_thread))
3009 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
3010
3011 // Wait for the VM thread to become ready, and VMThread::run to initialize
3012 // Monitors can have spurious returns, must always check another state flag
3013 {
3014 MutexLocker ml(Notify_lock);
3015 os::start_thread(vmthread);
3016 while (vmthread->active_handles() == NULL) {
3017 Notify_lock->wait();
3018 }
3019 }
3020 }
3021
3022 assert (Universe::is_fully_initialized(), "not initialized");
3023 EXCEPTION_MARK;
3024
3025 // At this point, the Universe is initialized, but we have not executed
3026 // any byte code. Now is a good time (the only time) to dump out the
3027 // internal state of the JVM for sharing.
3028
3029 if (DumpSharedSpaces) {
3030 Universe::heap()->preload_and_dump(CHECK_0);
3031 ShouldNotReachHere();
3032 }
3033
3034 // Always call even when there are not JVMTI environments yet, since environments
3035 // may be attached late and JVMTI must track phases of VM execution
3036 JvmtiExport::enter_start_phase();
3037
3038 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3039 JvmtiExport::post_vm_start();
3040
3041 {
3042 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3043
3044 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3045 create_vm_init_libraries();
3046 }
3047
3048 if (InitializeJavaLangString) {
3049 initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0);
3050 } else {
3051 warning("java.lang.String not initialized");
3052 }
3053
3054 if (AggressiveOpts) {
3055 {
3056 // Forcibly initialize java/util/HashMap and mutate the private
3057 // static final "frontCacheEnabled" field before we start creating instances
3058 #ifdef ASSERT
3059 klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3060 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
3061 #endif
3062 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3063 KlassHandle k = KlassHandle(THREAD, k_o);
3064 guarantee(k.not_null(), "Must find java/util/HashMap");
3065 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3066 ik->initialize(CHECK_0);
3067 fieldDescriptor fd;
3068 // Possible we might not find this field; if so, don't break
3069 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3070 k()->bool_field_put(fd.offset(), true);
3071 }
3072 }
3073
3074 if (UseStringCache) {
3075 // Forcibly initialize java/lang/StringValue and mutate the private
3076 // static final "stringCacheEnabled" field before we start creating instances
3077 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3078 // Possible that StringValue isn't present: if so, silently don't break
3079 if (k_o != NULL) {
3080 KlassHandle k = KlassHandle(THREAD, k_o);
3081 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3082 ik->initialize(CHECK_0);
3083 fieldDescriptor fd;
3084 // Possible we might not find this field: if so, silently don't break
3085 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3086 k()->bool_field_put(fd.offset(), true);
3087 }
3088 }
3089 }
3090 }
3091
3092 // Initialize java_lang.System (needed before creating the thread)
3093 if (InitializeJavaLangSystem) {
3094 initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0);
3095 initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0);
3096 Handle thread_group = create_initial_thread_group(CHECK_0);
3097 Universe::set_main_thread_group(thread_group());
3098 initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0);
3099 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3100 main_thread->set_threadObj(thread_object);
3101 // Set thread status to running since main thread has
3102 // been started and running.
3103 java_lang_Thread::set_thread_status(thread_object,
3104 java_lang_Thread::RUNNABLE);
3105
3106 // The VM preresolve methods to these classes. Make sure that get initialized
3107 initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0);
3108 initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0);
3109 // The VM creates & returns objects of this class. Make sure it's initialized.
3110 initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0);
3111 call_initializeSystemClass(CHECK_0);
3112 } else {
3113 warning("java.lang.System not initialized");
3114 }
3115
3116 // an instance of OutOfMemory exception has been allocated earlier
3117 if (InitializeJavaLangExceptionsErrors) {
3118 initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0);
3119 initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0);
3120 initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0);
3121 initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0);
3122 initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0);
3123 initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0);
3124 initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0);
3125 } else {
3126 warning("java.lang.OutOfMemoryError has not been initialized");
3127 warning("java.lang.NullPointerException has not been initialized");
3128 warning("java.lang.ClassCastException has not been initialized");
3129 warning("java.lang.ArrayStoreException has not been initialized");
3130 warning("java.lang.ArithmeticException has not been initialized");
3131 warning("java.lang.StackOverflowError has not been initialized");
3132 }
3133
3134 if (EnableInvokeDynamic) {
3135 // JSR 292: An intialized java.dyn.InvokeDynamic is required in
3136 // the compiler.
3137 initialize_class(vmSymbolHandles::java_dyn_InvokeDynamic(), CHECK_0);
3138 }
3139 }
3140
3141 // See : bugid 4211085.
3142 // Background : the static initializer of java.lang.Compiler tries to read
3143 // property"java.compiler" and read & write property "java.vm.info".
3144 // When a security manager is installed through the command line
3145 // option "-Djava.security.manager", the above properties are not
3146 // readable and the static initializer for java.lang.Compiler fails
3147 // resulting in a NoClassDefFoundError. This can happen in any
3148 // user code which calls methods in java.lang.Compiler.
3149 // Hack : the hack is to pre-load and initialize this class, so that only
3150 // system domains are on the stack when the properties are read.
3151 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3152 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3153 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3154 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3155 // Once that is done, we should remove this hack.
3156 initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0);
3157
3158 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3159 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3160 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3161 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3162 // This should also be taken out as soon as 4211383 gets fixed.
3163 reset_vm_info_property(CHECK_0);
3164
3165 quicken_jni_functions();
3166
3167 // Set flag that basic initialization has completed. Used by exceptions and various
3168 // debug stuff, that does not work until all basic classes have been initialized.
3169 set_init_completed();
3170
3171 HS_DTRACE_PROBE(hotspot, vm__init__end);
3172
3173 // record VM initialization completion time
3174 Management::record_vm_init_completed();
3175
3176 // Compute system loader. Note that this has to occur after set_init_completed, since
3177 // valid exceptions may be thrown in the process.
3178 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3179 // set_init_completed has just been called, causing exceptions not to be shortcut
3180 // anymore. We call vm_exit_during_initialization directly instead.
3181 SystemDictionary::compute_java_system_loader(THREAD);
3182 if (HAS_PENDING_EXCEPTION) {
3183 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3184 }
3185
3186 #ifdef KERNEL
3187 if (JDK_Version::is_gte_jdk17x_version()) {
3188 set_jkernel_boot_classloader_hook(THREAD);
3189 }
3190 #endif // KERNEL
3191
3192 #ifndef SERIALGC
3193 // Support for ConcurrentMarkSweep. This should be cleaned up
3194 // and better encapsulated. The ugly nested if test would go away
3195 // once things are properly refactored. XXX YSR
3196 if (UseConcMarkSweepGC || UseG1GC) {
3197 if (UseConcMarkSweepGC) {
3198 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3199 } else {
3200 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3201 }
3202 if (HAS_PENDING_EXCEPTION) {
3203 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3204 }
3205 }
3206 #endif // SERIALGC
3207
3208 // Always call even when there are not JVMTI environments yet, since environments
3209 // may be attached late and JVMTI must track phases of VM execution
3210 JvmtiExport::enter_live_phase();
3211
3212 // Signal Dispatcher needs to be started before VMInit event is posted
3213 os::signal_init();
3214
3215 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3216 if (!DisableAttachMechanism) {
3217 if (StartAttachListener || AttachListener::init_at_startup()) {
3218 AttachListener::init();
3219 }
3220 }
3221
3222 // Launch -Xrun agents
3223 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3224 // back-end can launch with -Xdebug -Xrunjdwp.
3225 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3226 create_vm_init_libraries();
3227 }
3228
3229 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3230 JvmtiExport::post_vm_initialized();
3231
3232 Chunk::start_chunk_pool_cleaner_task();
3233
3234 // initialize compiler(s)
3235 CompileBroker::compilation_init();
3236
3237 Management::initialize(THREAD);
3238 if (HAS_PENDING_EXCEPTION) {
3239 // management agent fails to start possibly due to
3240 // configuration problem and is responsible for printing
3241 // stack trace if appropriate. Simply exit VM.
3242 vm_exit(1);
3243 }
3244
3245 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3246 if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
3247 if (MemProfiling) MemProfiler::engage();
3248 StatSampler::engage();
3249 if (CheckJNICalls) JniPeriodicChecker::engage();
3250
3251 BiasedLocking::init();
3252
3253
3254 // Start up the WatcherThread if there are any periodic tasks
3255 // NOTE: All PeriodicTasks should be registered by now. If they
3256 // aren't, late joiners might appear to start slowly (we might
3257 // take a while to process their first tick).
3258 if (PeriodicTask::num_tasks() > 0) {
3259 WatcherThread::start();
3260 }
3261
3262 // Give os specific code one last chance to start
3263 os::init_3();
3264
3265 create_vm_timer.end();
3266 return JNI_OK;
3267 }
3268
3269 // type for the Agent_OnLoad and JVM_OnLoad entry points
3270 extern "C" {
3271 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3272 }
3273 // Find a command line agent library and return its entry point for
3274 // -agentlib: -agentpath: -Xrun
3275 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3276 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3277 OnLoadEntry_t on_load_entry = NULL;
3278 void *library = agent->os_lib(); // check if we have looked it up before
3279
3280 if (library == NULL) {
3281 char buffer[JVM_MAXPATHLEN];
3282 char ebuf[1024];
3283 const char *name = agent->name();
3284 const char *msg = "Could not find agent library ";
3285
3286 if (agent->is_absolute_path()) {
3287 library = hpi::dll_load(name, ebuf, sizeof ebuf);
3288 if (library == NULL) {
3289 const char *sub_msg = " in absolute path, with error: ";
3290 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3291 char *buf = NEW_C_HEAP_ARRAY(char, len);
3292 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3293 // If we can't find the agent, exit.
3294 vm_exit_during_initialization(buf, NULL);
3295 FREE_C_HEAP_ARRAY(char, buf);
3296 }
3297 } else {
3298 // Try to load the agent from the standard dll directory
3299 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name);
3300 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3301 #ifdef KERNEL
3302 // Download instrument dll
3303 if (library == NULL && strcmp(name, "instrument") == 0) {
3304 char *props = Arguments::get_kernel_properties();
3305 char *home = Arguments::get_java_home();
3306 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false"
3307 " sun.jkernel.DownloadManager -download client_jvm";
3308 size_t length = strlen(props) + strlen(home) + strlen(fmt) + 1;
3309 char *cmd = NEW_C_HEAP_ARRAY(char, length);
3310 jio_snprintf(cmd, length, fmt, home, props);
3311 int status = os::fork_and_exec(cmd);
3312 FreeHeap(props);
3313 if (status == -1) {
3314 warning(cmd);
3315 vm_exit_during_initialization("fork_and_exec failed: %s",
3316 strerror(errno));
3317 }
3318 FREE_C_HEAP_ARRAY(char, cmd);
3319 // when this comes back the instrument.dll should be where it belongs.
3320 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3321 }
3322 #endif // KERNEL
3323 if (library == NULL) { // Try the local directory
3324 char ns[1] = {0};
3325 hpi::dll_build_name(buffer, sizeof(buffer), ns, name);
3326 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3327 if (library == NULL) {
3328 const char *sub_msg = " on the library path, with error: ";
3329 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3330 char *buf = NEW_C_HEAP_ARRAY(char, len);
3331 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3332 // If we can't find the agent, exit.
3333 vm_exit_during_initialization(buf, NULL);
3334 FREE_C_HEAP_ARRAY(char, buf);
3335 }
3336 }
3337 }
3338 agent->set_os_lib(library);
3339 }
3340
3341 // Find the OnLoad function.
3342 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
3343 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index]));
3344 if (on_load_entry != NULL) break;
3345 }
3346 return on_load_entry;
3347 }
3348
3349 // Find the JVM_OnLoad entry point
3350 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3351 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3352 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3353 }
3354
3355 // Find the Agent_OnLoad entry point
3356 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3357 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3358 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3359 }
3360
3361 // For backwards compatibility with -Xrun
3362 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3363 // treated like -agentpath:
3364 // Must be called before agent libraries are created
3365 void Threads::convert_vm_init_libraries_to_agents() {
3366 AgentLibrary* agent;
3367 AgentLibrary* next;
3368
3369 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3370 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3371 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3372
3373 // If there is an JVM_OnLoad function it will get called later,
3374 // otherwise see if there is an Agent_OnLoad
3375 if (on_load_entry == NULL) {
3376 on_load_entry = lookup_agent_on_load(agent);
3377 if (on_load_entry != NULL) {
3378 // switch it to the agent list -- so that Agent_OnLoad will be called,
3379 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3380 Arguments::convert_library_to_agent(agent);
3381 } else {
3382 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3383 }
3384 }
3385 }
3386 }
3387
3388 // Create agents for -agentlib: -agentpath: and converted -Xrun
3389 // Invokes Agent_OnLoad
3390 // Called very early -- before JavaThreads exist
3391 void Threads::create_vm_init_agents() {
3392 extern struct JavaVM_ main_vm;
3393 AgentLibrary* agent;
3394
3395 JvmtiExport::enter_onload_phase();
3396 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3397 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3398
3399 if (on_load_entry != NULL) {
3400 // Invoke the Agent_OnLoad function
3401 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3402 if (err != JNI_OK) {
3403 vm_exit_during_initialization("agent library failed to init", agent->name());
3404 }
3405 } else {
3406 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3407 }
3408 }
3409 JvmtiExport::enter_primordial_phase();
3410 }
3411
3412 extern "C" {
3413 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3414 }
3415
3416 void Threads::shutdown_vm_agents() {
3417 // Send any Agent_OnUnload notifications
3418 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3419 extern struct JavaVM_ main_vm;
3420 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3421
3422 // Find the Agent_OnUnload function.
3423 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
3424 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3425 hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
3426
3427 // Invoke the Agent_OnUnload function
3428 if (unload_entry != NULL) {
3429 JavaThread* thread = JavaThread::current();
3430 ThreadToNativeFromVM ttn(thread);
3431 HandleMark hm(thread);
3432 (*unload_entry)(&main_vm);
3433 break;
3434 }
3435 }
3436 }
3437 }
3438
3439 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3440 // Invokes JVM_OnLoad
3441 void Threads::create_vm_init_libraries() {
3442 extern struct JavaVM_ main_vm;
3443 AgentLibrary* agent;
3444
3445 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3446 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3447
3448 if (on_load_entry != NULL) {
3449 // Invoke the JVM_OnLoad function
3450 JavaThread* thread = JavaThread::current();
3451 ThreadToNativeFromVM ttn(thread);
3452 HandleMark hm(thread);
3453 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3454 if (err != JNI_OK) {
3455 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3456 }
3457 } else {
3458 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3459 }
3460 }
3461 }
3462
3463 // Last thread running calls java.lang.Shutdown.shutdown()
3464 void JavaThread::invoke_shutdown_hooks() {
3465 HandleMark hm(this);
3466
3467 // We could get here with a pending exception, if so clear it now.
3468 if (this->has_pending_exception()) {
3469 this->clear_pending_exception();
3470 }
3471
3472 EXCEPTION_MARK;
3473 klassOop k =
3474 SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(),
3475 THREAD);
3476 if (k != NULL) {
3477 // SystemDictionary::resolve_or_null will return null if there was
3478 // an exception. If we cannot load the Shutdown class, just don't
3479 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3480 // and finalizers (if runFinalizersOnExit is set) won't be run.
3481 // Note that if a shutdown hook was registered or runFinalizersOnExit
3482 // was called, the Shutdown class would have already been loaded
3483 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3484 instanceKlassHandle shutdown_klass (THREAD, k);
3485 JavaValue result(T_VOID);
3486 JavaCalls::call_static(&result,
3487 shutdown_klass,
3488 vmSymbolHandles::shutdown_method_name(),
3489 vmSymbolHandles::void_method_signature(),
3490 THREAD);
3491 }
3492 CLEAR_PENDING_EXCEPTION;
3493 }
3494
3495 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3496 // the program falls off the end of main(). Another VM exit path is through
3497 // vm_exit() when the program calls System.exit() to return a value or when
3498 // there is a serious error in VM. The two shutdown paths are not exactly
3499 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3500 // and VM_Exit op at VM level.
3501 //
3502 // Shutdown sequence:
3503 // + Wait until we are the last non-daemon thread to execute
3504 // <-- every thing is still working at this moment -->
3505 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3506 // shutdown hooks, run finalizers if finalization-on-exit
3507 // + Call before_exit(), prepare for VM exit
3508 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3509 // currently the only user of this mechanism is File.deleteOnExit())
3510 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3511 // post thread end and vm death events to JVMTI,
3512 // stop signal thread
3513 // + Call JavaThread::exit(), it will:
3514 // > release JNI handle blocks, remove stack guard pages
3515 // > remove this thread from Threads list
3516 // <-- no more Java code from this thread after this point -->
3517 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3518 // the compiler threads at safepoint
3519 // <-- do not use anything that could get blocked by Safepoint -->
3520 // + Disable tracing at JNI/JVM barriers
3521 // + Set _vm_exited flag for threads that are still running native code
3522 // + Delete this thread
3523 // + Call exit_globals()
3524 // > deletes tty
3525 // > deletes PerfMemory resources
3526 // + Return to caller
3527
3528 bool Threads::destroy_vm() {
3529 JavaThread* thread = JavaThread::current();
3530
3531 // Wait until we are the last non-daemon thread to execute
3532 { MutexLocker nu(Threads_lock);
3533 while (Threads::number_of_non_daemon_threads() > 1 )
3534 // This wait should make safepoint checks, wait without a timeout,
3535 // and wait as a suspend-equivalent condition.
3536 //
3537 // Note: If the FlatProfiler is running and this thread is waiting
3538 // for another non-daemon thread to finish, then the FlatProfiler
3539 // is waiting for the external suspend request on this thread to
3540 // complete. wait_for_ext_suspend_completion() will eventually
3541 // timeout, but that takes time. Making this wait a suspend-
3542 // equivalent condition solves that timeout problem.
3543 //
3544 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
3545 Mutex::_as_suspend_equivalent_flag);
3546 }
3547
3548 // Hang forever on exit if we are reporting an error.
3549 if (ShowMessageBoxOnError && is_error_reported()) {
3550 os::infinite_sleep();
3551 }
3552
3553 if (JDK_Version::is_jdk12x_version()) {
3554 // We are the last thread running, so check if finalizers should be run.
3555 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
3556 HandleMark rm(thread);
3557 Universe::run_finalizers_on_exit();
3558 } else {
3559 // run Java level shutdown hooks
3560 thread->invoke_shutdown_hooks();
3561 }
3562
3563 before_exit(thread);
3564
3565 thread->exit(true);
3566
3567 // Stop VM thread.
3568 {
3569 // 4945125 The vm thread comes to a safepoint during exit.
3570 // GC vm_operations can get caught at the safepoint, and the
3571 // heap is unparseable if they are caught. Grab the Heap_lock
3572 // to prevent this. The GC vm_operations will not be able to
3573 // queue until after the vm thread is dead.
3574 MutexLocker ml(Heap_lock);
3575
3576 VMThread::wait_for_vm_thread_exit();
3577 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3578 VMThread::destroy();
3579 }
3580
3581 // clean up ideal graph printers
3582 #if defined(COMPILER2) && !defined(PRODUCT)
3583 IdealGraphPrinter::clean_up();
3584 #endif
3585
3586 // Now, all Java threads are gone except daemon threads. Daemon threads
3587 // running Java code or in VM are stopped by the Safepoint. However,
3588 // daemon threads executing native code are still running. But they
3589 // will be stopped at native=>Java/VM barriers. Note that we can't
3590 // simply kill or suspend them, as it is inherently deadlock-prone.
3591
3592 #ifndef PRODUCT
3593 // disable function tracing at JNI/JVM barriers
3594 TraceHPI = false;
3595 TraceJNICalls = false;
3596 TraceJVMCalls = false;
3597 TraceRuntimeCalls = false;
3598 #endif
3599
3600 VM_Exit::set_vm_exited();
3601
3602 notify_vm_shutdown();
3603
3604 delete thread;
3605
3606 // exit_globals() will delete tty
3607 exit_globals();
3608
3609 return true;
3610 }
3611
3612
3613 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3614 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3615 return is_supported_jni_version(version);
3616 }
3617
3618
3619 jboolean Threads::is_supported_jni_version(jint version) {
3620 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3621 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3622 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3623 return JNI_FALSE;
3624 }
3625
3626
3627 void Threads::add(JavaThread* p, bool force_daemon) {
3628 // The threads lock must be owned at this point
3629 assert_locked_or_safepoint(Threads_lock);
3630 p->set_next(_thread_list);
3631 _thread_list = p;
3632 _number_of_threads++;
3633 oop threadObj = p->threadObj();
3634 bool daemon = true;
3635 // Bootstrapping problem: threadObj can be null for initial
3636 // JavaThread (or for threads attached via JNI)
3637 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
3638 _number_of_non_daemon_threads++;
3639 daemon = false;
3640 }
3641
3642 ThreadService::add_thread(p, daemon);
3643
3644 // Possible GC point.
3645 Events::log("Thread added: " INTPTR_FORMAT, p);
3646 }
3647
3648 void Threads::remove(JavaThread* p) {
3649 // Extra scope needed for Thread_lock, so we can check
3650 // that we do not remove thread without safepoint code notice
3651 { MutexLocker ml(Threads_lock);
3652
3653 assert(includes(p), "p must be present");
3654
3655 JavaThread* current = _thread_list;
3656 JavaThread* prev = NULL;
3657
3658 while (current != p) {
3659 prev = current;
3660 current = current->next();
3661 }
3662
3663 if (prev) {
3664 prev->set_next(current->next());
3665 } else {
3666 _thread_list = p->next();
3667 }
3668 _number_of_threads--;
3669 oop threadObj = p->threadObj();
3670 bool daemon = true;
3671 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
3672 _number_of_non_daemon_threads--;
3673 daemon = false;
3674
3675 // Only one thread left, do a notify on the Threads_lock so a thread waiting
3676 // on destroy_vm will wake up.
3677 if (number_of_non_daemon_threads() == 1)
3678 Threads_lock->notify_all();
3679 }
3680 ThreadService::remove_thread(p, daemon);
3681
3682 // Make sure that safepoint code disregard this thread. This is needed since
3683 // the thread might mess around with locks after this point. This can cause it
3684 // to do callbacks into the safepoint code. However, the safepoint code is not aware
3685 // of this thread since it is removed from the queue.
3686 p->set_terminated_value();
3687 } // unlock Threads_lock
3688
3689 // Since Events::log uses a lock, we grab it outside the Threads_lock
3690 Events::log("Thread exited: " INTPTR_FORMAT, p);
3691 }
3692
3693 // Threads_lock must be held when this is called (or must be called during a safepoint)
3694 bool Threads::includes(JavaThread* p) {
3695 assert(Threads_lock->is_locked(), "sanity check");
3696 ALL_JAVA_THREADS(q) {
3697 if (q == p ) {
3698 return true;
3699 }
3700 }
3701 return false;
3702 }
3703
3704 // Operations on the Threads list for GC. These are not explicitly locked,
3705 // but the garbage collector must provide a safe context for them to run.
3706 // In particular, these things should never be called when the Threads_lock
3707 // is held by some other thread. (Note: the Safepoint abstraction also
3708 // uses the Threads_lock to gurantee this property. It also makes sure that
3709 // all threads gets blocked when exiting or starting).
3710
3711 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3712 ALL_JAVA_THREADS(p) {
3713 p->oops_do(f, cf);
3714 }
3715 VMThread::vm_thread()->oops_do(f, cf);
3716 }
3717
3718 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) {
3719 // Introduce a mechanism allowing parallel threads to claim threads as
3720 // root groups. Overhead should be small enough to use all the time,
3721 // even in sequential code.
3722 SharedHeap* sh = SharedHeap::heap();
3723 bool is_par = (sh->n_par_threads() > 0);
3724 int cp = SharedHeap::heap()->strong_roots_parity();
3725 ALL_JAVA_THREADS(p) {
3726 if (p->claim_oops_do(is_par, cp)) {
3727 p->oops_do(f, cf);
3728 }
3729 }
3730 VMThread* vmt = VMThread::vm_thread();
3731 if (vmt->claim_oops_do(is_par, cp))
3732 vmt->oops_do(f, cf);
3733 }
3734
3735 #ifndef SERIALGC
3736 // Used by ParallelScavenge
3737 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
3738 ALL_JAVA_THREADS(p) {
3739 q->enqueue(new ThreadRootsTask(p));
3740 }
3741 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
3742 }
3743
3744 // Used by Parallel Old
3745 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
3746 ALL_JAVA_THREADS(p) {
3747 q->enqueue(new ThreadRootsMarkingTask(p));
3748 }
3749 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
3750 }
3751 #endif // SERIALGC
3752
3753 void Threads::nmethods_do(CodeBlobClosure* cf) {
3754 ALL_JAVA_THREADS(p) {
3755 p->nmethods_do(cf);
3756 }
3757 VMThread::vm_thread()->nmethods_do(cf);
3758 }
3759
3760 void Threads::gc_epilogue() {
3761 ALL_JAVA_THREADS(p) {
3762 p->gc_epilogue();
3763 }
3764 }
3765
3766 void Threads::gc_prologue() {
3767 ALL_JAVA_THREADS(p) {
3768 p->gc_prologue();
3769 }
3770 }
3771
3772 void Threads::deoptimized_wrt_marked_nmethods() {
3773 ALL_JAVA_THREADS(p) {
3774 p->deoptimized_wrt_marked_nmethods();
3775 }
3776 }
3777
3778
3779 // Get count Java threads that are waiting to enter the specified monitor.
3780 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
3781 address monitor, bool doLock) {
3782 assert(doLock || SafepointSynchronize::is_at_safepoint(),
3783 "must grab Threads_lock or be at safepoint");
3784 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
3785
3786 int i = 0;
3787 {
3788 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3789 ALL_JAVA_THREADS(p) {
3790 if (p->is_Compiler_thread()) continue;
3791
3792 address pending = (address)p->current_pending_monitor();
3793 if (pending == monitor) { // found a match
3794 if (i < count) result->append(p); // save the first count matches
3795 i++;
3796 }
3797 }
3798 }
3799 return result;
3800 }
3801
3802
3803 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
3804 assert(doLock ||
3805 Threads_lock->owned_by_self() ||
3806 SafepointSynchronize::is_at_safepoint(),
3807 "must grab Threads_lock or be at safepoint");
3808
3809 // NULL owner means not locked so we can skip the search
3810 if (owner == NULL) return NULL;
3811
3812 {
3813 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3814 ALL_JAVA_THREADS(p) {
3815 // first, see if owner is the address of a Java thread
3816 if (owner == (address)p) return p;
3817 }
3818 }
3819 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
3820 if (UseHeavyMonitors) return NULL;
3821
3822 //
3823 // If we didn't find a matching Java thread and we didn't force use of
3824 // heavyweight monitors, then the owner is the stack address of the
3825 // Lock Word in the owning Java thread's stack.
3826 //
3827 JavaThread* the_owner = NULL;
3828 {
3829 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3830 ALL_JAVA_THREADS(q) {
3831 if (q->is_lock_owned(owner)) {
3832 the_owner = q;
3833 break;
3834 }
3835 }
3836 }
3837 assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
3838 return the_owner;
3839 }
3840
3841 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
3842 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
3843 char buf[32];
3844 st->print_cr(os::local_time_string(buf, sizeof(buf)));
3845
3846 st->print_cr("Full thread dump %s (%s %s):",
3847 Abstract_VM_Version::vm_name(),
3848 Abstract_VM_Version::vm_release(),
3849 Abstract_VM_Version::vm_info_string()
3850 );
3851 st->cr();
3852
3853 #ifndef SERIALGC
3854 // Dump concurrent locks
3855 ConcurrentLocksDump concurrent_locks;
3856 if (print_concurrent_locks) {
3857 concurrent_locks.dump_at_safepoint();
3858 }
3859 #endif // SERIALGC
3860
3861 ALL_JAVA_THREADS(p) {
3862 ResourceMark rm;
3863 p->print_on(st);
3864 if (print_stacks) {
3865 if (internal_format) {
3866 p->trace_stack();
3867 } else {
3868 p->print_stack_on(st);
3869 }
3870 }
3871 st->cr();
3872 #ifndef SERIALGC
3873 if (print_concurrent_locks) {
3874 concurrent_locks.print_locks_on(p, st);
3875 }
3876 #endif // SERIALGC
3877 }
3878
3879 VMThread::vm_thread()->print_on(st);
3880 st->cr();
3881 Universe::heap()->print_gc_threads_on(st);
3882 WatcherThread* wt = WatcherThread::watcher_thread();
3883 if (wt != NULL) wt->print_on(st);
3884 st->cr();
3885 CompileBroker::print_compiler_threads_on(st);
3886 st->flush();
3887 }
3888
3889 // Threads::print_on_error() is called by fatal error handler. It's possible
3890 // that VM is not at safepoint and/or current thread is inside signal handler.
3891 // Don't print stack trace, as the stack may not be walkable. Don't allocate
3892 // memory (even in resource area), it might deadlock the error handler.
3893 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
3894 bool found_current = false;
3895 st->print_cr("Java Threads: ( => current thread )");
3896 ALL_JAVA_THREADS(thread) {
3897 bool is_current = (current == thread);
3898 found_current = found_current || is_current;
3899
3900 st->print("%s", is_current ? "=>" : " ");
3901
3902 st->print(PTR_FORMAT, thread);
3903 st->print(" ");
3904 thread->print_on_error(st, buf, buflen);
3905 st->cr();
3906 }
3907 st->cr();
3908
3909 st->print_cr("Other Threads:");
3910 if (VMThread::vm_thread()) {
3911 bool is_current = (current == VMThread::vm_thread());
3912 found_current = found_current || is_current;
3913 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
3914
3915 st->print(PTR_FORMAT, VMThread::vm_thread());
3916 st->print(" ");
3917 VMThread::vm_thread()->print_on_error(st, buf, buflen);
3918 st->cr();
3919 }
3920 WatcherThread* wt = WatcherThread::watcher_thread();
3921 if (wt != NULL) {
3922 bool is_current = (current == wt);
3923 found_current = found_current || is_current;
3924 st->print("%s", is_current ? "=>" : " ");
3925
3926 st->print(PTR_FORMAT, wt);
3927 st->print(" ");
3928 wt->print_on_error(st, buf, buflen);
3929 st->cr();
3930 }
3931 if (!found_current) {
3932 st->cr();
3933 st->print("=>" PTR_FORMAT " (exited) ", current);
3934 current->print_on_error(st, buf, buflen);
3935 st->cr();
3936 }
3937 }
3938
3939
3940 // Lifecycle management for TSM ParkEvents.
3941 // ParkEvents are type-stable (TSM).
3942 // In our particular implementation they happen to be immortal.
3943 //
3944 // We manage concurrency on the FreeList with a CAS-based
3945 // detach-modify-reattach idiom that avoids the ABA problems
3946 // that would otherwise be present in a simple CAS-based
3947 // push-pop implementation. (push-one and pop-all)
3948 //
3949 // Caveat: Allocate() and Release() may be called from threads
3950 // other than the thread associated with the Event!
3951 // If we need to call Allocate() when running as the thread in
3952 // question then look for the PD calls to initialize native TLS.
3953 // Native TLS (Win32/Linux/Solaris) can only be initialized or
3954 // accessed by the associated thread.
3955 // See also pd_initialize().
3956 //
3957 // Note that we could defer associating a ParkEvent with a thread
3958 // until the 1st time the thread calls park(). unpark() calls to
3959 // an unprovisioned thread would be ignored. The first park() call
3960 // for a thread would allocate and associate a ParkEvent and return
3961 // immediately.
3962
3963 volatile int ParkEvent::ListLock = 0 ;
3964 ParkEvent * volatile ParkEvent::FreeList = NULL ;
3965
3966 ParkEvent * ParkEvent::Allocate (Thread * t) {
3967 // In rare cases -- JVM_RawMonitor* operations -- we can find t == null.
3968 ParkEvent * ev ;
3969
3970 // Start by trying to recycle an existing but unassociated
3971 // ParkEvent from the global free list.
3972 for (;;) {
3973 ev = FreeList ;
3974 if (ev == NULL) break ;
3975 // 1: Detach - sequester or privatize the list
3976 // Tantamount to ev = Swap (&FreeList, NULL)
3977 if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) {
3978 continue ;
3979 }
3980
3981 // We've detached the list. The list in-hand is now
3982 // local to this thread. This thread can operate on the
3983 // list without risk of interference from other threads.
3984 // 2: Extract -- pop the 1st element from the list.
3985 ParkEvent * List = ev->FreeNext ;
3986 if (List == NULL) break ;
3987 for (;;) {
3988 // 3: Try to reattach the residual list
3989 guarantee (List != NULL, "invariant") ;
3990 ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
3991 if (Arv == NULL) break ;
3992
3993 // New nodes arrived. Try to detach the recent arrivals.
3994 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
3995 continue ;
3996 }
3997 guarantee (Arv != NULL, "invariant") ;
3998 // 4: Merge Arv into List
3999 ParkEvent * Tail = List ;
4000 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
4001 Tail->FreeNext = Arv ;
4002 }
4003 break ;
4004 }
4005
4006 if (ev != NULL) {
4007 guarantee (ev->AssociatedWith == NULL, "invariant") ;
4008 } else {
4009 // Do this the hard way -- materialize a new ParkEvent.
4010 // In rare cases an allocating thread might detach a long list --
4011 // installing null into FreeList -- and then stall or be obstructed.
4012 // A 2nd thread calling Allocate() would see FreeList == null.
4013 // The list held privately by the 1st thread is unavailable to the 2nd thread.
4014 // In that case the 2nd thread would have to materialize a new ParkEvent,
4015 // even though free ParkEvents existed in the system. In this case we end up
4016 // with more ParkEvents in circulation than we need, but the race is
4017 // rare and the outcome is benign. Ideally, the # of extant ParkEvents
4018 // is equal to the maximum # of threads that existed at any one time.
4019 // Because of the race mentioned above, segments of the freelist
4020 // can be transiently inaccessible. At worst we may end up with the
4021 // # of ParkEvents in circulation slightly above the ideal.
4022 // Note that if we didn't have the TSM/immortal constraint, then
4023 // when reattaching, above, we could trim the list.
4024 ev = new ParkEvent () ;
4025 guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ;
4026 }
4027 ev->reset() ; // courtesy to caller
4028 ev->AssociatedWith = t ; // Associate ev with t
4029 ev->FreeNext = NULL ;
4030 return ev ;
4031 }
4032
4033 void ParkEvent::Release (ParkEvent * ev) {
4034 if (ev == NULL) return ;
4035 guarantee (ev->FreeNext == NULL , "invariant") ;
4036 ev->AssociatedWith = NULL ;
4037 for (;;) {
4038 // Push ev onto FreeList
4039 // The mechanism is "half" lock-free.
4040 ParkEvent * List = FreeList ;
4041 ev->FreeNext = List ;
4042 if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ;
4043 }
4044 }
4045
4046 // Override operator new and delete so we can ensure that the
4047 // least significant byte of ParkEvent addresses is 0.
4048 // Beware that excessive address alignment is undesirable
4049 // as it can result in D$ index usage imbalance as
4050 // well as bank access imbalance on Niagara-like platforms,
4051 // although Niagara's hash function should help.
4052
4053 void * ParkEvent::operator new (size_t sz) {
4054 return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ;
4055 }
4056
4057 void ParkEvent::operator delete (void * a) {
4058 // ParkEvents are type-stable and immortal ...
4059 ShouldNotReachHere();
4060 }
4061
4062
4063 // 6399321 As a temporary measure we copied & modified the ParkEvent::
4064 // allocate() and release() code for use by Parkers. The Parker:: forms
4065 // will eventually be removed as we consolide and shift over to ParkEvents
4066 // for both builtin synchronization and JSR166 operations.
4067
4068 volatile int Parker::ListLock = 0 ;
4069 Parker * volatile Parker::FreeList = NULL ;
4070
4071 Parker * Parker::Allocate (JavaThread * t) {
4072 guarantee (t != NULL, "invariant") ;
4073 Parker * p ;
4074
4075 // Start by trying to recycle an existing but unassociated
4076 // Parker from the global free list.
4077 for (;;) {
4078 p = FreeList ;
4079 if (p == NULL) break ;
4080 // 1: Detach
4081 // Tantamount to p = Swap (&FreeList, NULL)
4082 if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) {
4083 continue ;
4084 }
4085
4086 // We've detached the list. The list in-hand is now
4087 // local to this thread. This thread can operate on the
4088 // list without risk of interference from other threads.
4089 // 2: Extract -- pop the 1st element from the list.
4090 Parker * List = p->FreeNext ;
4091 if (List == NULL) break ;
4092 for (;;) {
4093 // 3: Try to reattach the residual list
4094 guarantee (List != NULL, "invariant") ;
4095 Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
4096 if (Arv == NULL) break ;
4097
4098 // New nodes arrived. Try to detach the recent arrivals.
4099 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
4100 continue ;
4101 }
4102 guarantee (Arv != NULL, "invariant") ;
4103 // 4: Merge Arv into List
4104 Parker * Tail = List ;
4105 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
4106 Tail->FreeNext = Arv ;
4107 }
4108 break ;
4109 }
4110
4111 if (p != NULL) {
4112 guarantee (p->AssociatedWith == NULL, "invariant") ;
4113 } else {
4114 // Do this the hard way -- materialize a new Parker..
4115 // In rare cases an allocating thread might detach
4116 // a long list -- installing null into FreeList --and
4117 // then stall. Another thread calling Allocate() would see
4118 // FreeList == null and then invoke the ctor. In this case we
4119 // end up with more Parkers in circulation than we need, but
4120 // the race is rare and the outcome is benign.
4121 // Ideally, the # of extant Parkers is equal to the
4122 // maximum # of threads that existed at any one time.
4123 // Because of the race mentioned above, segments of the
4124 // freelist can be transiently inaccessible. At worst
4125 // we may end up with the # of Parkers in circulation
4126 // slightly above the ideal.
4127 p = new Parker() ;
4128 }
4129 p->AssociatedWith = t ; // Associate p with t
4130 p->FreeNext = NULL ;
4131 return p ;
4132 }
4133
4134
4135 void Parker::Release (Parker * p) {
4136 if (p == NULL) return ;
4137 guarantee (p->AssociatedWith != NULL, "invariant") ;
4138 guarantee (p->FreeNext == NULL , "invariant") ;
4139 p->AssociatedWith = NULL ;
4140 for (;;) {
4141 // Push p onto FreeList
4142 Parker * List = FreeList ;
4143 p->FreeNext = List ;
4144 if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ;
4145 }
4146 }
4147
4148 void Threads::verify() {
4149 ALL_JAVA_THREADS(p) {
4150 p->verify();
4151 }
4152 VMThread* thread = VMThread::vm_thread();
4153 if (thread != NULL) thread->verify();
4154 }