1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any 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
143 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
144 _suspend_flags = 0;
145
146 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
147 _hashStateX = os::random() ;
148 _hashStateY = 842502087 ;
149 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
150 _hashStateW = 273326509 ;
151
152 _OnTrap = 0 ;
153 _schedctl = NULL ;
154 _Stalled = 0 ;
155 _TypeTag = 0x2BAD ;
156
157 // Many of the following fields are effectively final - immutable
158 // Note that nascent threads can't use the Native Monitor-Mutex
159 // construct until the _MutexEvent is initialized ...
160 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
161 // we might instead use a stack of ParkEvents that we could provision on-demand.
162 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
163 // and ::Release()
164 _ParkEvent = ParkEvent::Allocate (this) ;
165 _SleepEvent = ParkEvent::Allocate (this) ;
166 _MutexEvent = ParkEvent::Allocate (this) ;
167 _MuxEvent = ParkEvent::Allocate (this) ;
168
169 #ifdef CHECK_UNHANDLED_OOPS
170 if (CheckUnhandledOops) {
171 _unhandled_oops = new UnhandledOops(this);
172 }
173 #endif // CHECK_UNHANDLED_OOPS
174 #ifdef ASSERT
175 if (UseBiasedLocking) {
176 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
177 assert(this == _real_malloc_address ||
178 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
179 "bug in forced alignment of thread objects");
180 }
181 #endif /* ASSERT */
182 }
183
184 void Thread::initialize_thread_local_storage() {
185 // Note: Make sure this method only calls
186 // non-blocking operations. Otherwise, it might not work
187 // with the thread-startup/safepoint interaction.
188
189 // During Java thread startup, safepoint code should allow this
190 // method to complete because it may need to allocate memory to
191 // store information for the new thread.
192
193 // initialize structure dependent on thread local storage
194 ThreadLocalStorage::set_thread(this);
195
196 // set up any platform-specific state.
197 os::initialize_thread();
198
199 }
200
201 void Thread::record_stack_base_and_size() {
202 set_stack_base(os::current_stack_base());
203 set_stack_size(os::current_stack_size());
204 }
205
206
207 Thread::~Thread() {
208 // Reclaim the objectmonitors from the omFreeList of the moribund thread.
209 ObjectSynchronizer::omFlush (this) ;
210
211 // deallocate data structures
212 delete resource_area();
213 // since the handle marks are using the handle area, we have to deallocated the root
214 // handle mark before deallocating the thread's handle area,
215 assert(last_handle_mark() != NULL, "check we have an element");
216 delete last_handle_mark();
217 assert(last_handle_mark() == NULL, "check we have reached the end");
218
219 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
220 // We NULL out the fields for good hygiene.
221 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
222 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
223 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
224 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
225
226 delete handle_area();
227
228 // osthread() can be NULL, if creation of thread failed.
229 if (osthread() != NULL) os::free_thread(osthread());
230
231 delete _SR_lock;
232
233 // clear thread local storage if the Thread is deleting itself
234 if (this == Thread::current()) {
235 ThreadLocalStorage::set_thread(NULL);
236 } else {
237 // In the case where we're not the current thread, invalidate all the
238 // caches in case some code tries to get the current thread or the
239 // thread that was destroyed, and gets stale information.
240 ThreadLocalStorage::invalidate_all();
241 }
242 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
243 }
244
245 // NOTE: dummy function for assertion purpose.
246 void Thread::run() {
247 ShouldNotReachHere();
248 }
249
250 #ifdef ASSERT
251 // Private method to check for dangling thread pointer
252 void check_for_dangling_thread_pointer(Thread *thread) {
253 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
254 "possibility of dangling Thread pointer");
255 }
256 #endif
257
258
259 #ifndef PRODUCT
260 // Tracing method for basic thread operations
261 void Thread::trace(const char* msg, const Thread* const thread) {
262 if (!TraceThreadEvents) return;
263 ResourceMark rm;
264 ThreadCritical tc;
265 const char *name = "non-Java thread";
266 int prio = -1;
267 if (thread->is_Java_thread()
268 && !thread->is_Compiler_thread()) {
269 // The Threads_lock must be held to get information about
270 // this thread but may not be in some situations when
271 // tracing thread events.
272 bool release_Threads_lock = false;
273 if (!Threads_lock->owned_by_self()) {
274 Threads_lock->lock();
275 release_Threads_lock = true;
276 }
277 JavaThread* jt = (JavaThread *)thread;
278 name = (char *)jt->get_thread_name();
279 oop thread_oop = jt->threadObj();
280 if (thread_oop != NULL) {
281 prio = java_lang_Thread::priority(thread_oop);
282 }
283 if (release_Threads_lock) {
284 Threads_lock->unlock();
285 }
286 }
287 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
288 }
289 #endif
290
291
292 ThreadPriority Thread::get_priority(const Thread* const thread) {
293 trace("get priority", thread);
294 ThreadPriority priority;
295 // Can return an error!
296 (void)os::get_priority(thread, priority);
297 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
298 return priority;
299 }
300
301 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
302 trace("set priority", thread);
303 debug_only(check_for_dangling_thread_pointer(thread);)
304 // Can return an error!
305 (void)os::set_priority(thread, priority);
306 }
307
308
309 void Thread::start(Thread* thread) {
310 trace("start", thread);
311 // Start is different from resume in that its safety is guaranteed by context or
312 // being called from a Java method synchronized on the Thread object.
313 if (!DisableStartThread) {
314 if (thread->is_Java_thread()) {
315 // Initialize the thread state to RUNNABLE before starting this thread.
316 // Can not set it after the thread started because we do not know the
317 // exact thread state at that time. It could be in MONITOR_WAIT or
318 // in SLEEPING or some other state.
319 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
320 java_lang_Thread::RUNNABLE);
321 }
322 os::start_thread(thread);
323 }
324 }
325
326 // Enqueue a VM_Operation to do the job for us - sometime later
327 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
328 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
329 VMThread::execute(vm_stop);
330 }
331
332
333 //
334 // Check if an external suspend request has completed (or has been
335 // cancelled). Returns true if the thread is externally suspended and
336 // false otherwise.
337 //
338 // The bits parameter returns information about the code path through
339 // the routine. Useful for debugging:
340 //
341 // set in is_ext_suspend_completed():
342 // 0x00000001 - routine was entered
343 // 0x00000010 - routine return false at end
344 // 0x00000100 - thread exited (return false)
345 // 0x00000200 - suspend request cancelled (return false)
346 // 0x00000400 - thread suspended (return true)
347 // 0x00001000 - thread is in a suspend equivalent state (return true)
348 // 0x00002000 - thread is native and walkable (return true)
349 // 0x00004000 - thread is native_trans and walkable (needed retry)
350 //
351 // set in wait_for_ext_suspend_completion():
352 // 0x00010000 - routine was entered
353 // 0x00020000 - suspend request cancelled before loop (return false)
354 // 0x00040000 - thread suspended before loop (return true)
355 // 0x00080000 - suspend request cancelled in loop (return false)
356 // 0x00100000 - thread suspended in loop (return true)
357 // 0x00200000 - suspend not completed during retry loop (return false)
358 //
359
360 // Helper class for tracing suspend wait debug bits.
361 //
362 // 0x00000100 indicates that the target thread exited before it could
363 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
364 // 0x00080000 each indicate a cancelled suspend request so they don't
365 // count as wait failures either.
366 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
367
368 class TraceSuspendDebugBits : public StackObj {
369 private:
370 JavaThread * jt;
371 bool is_wait;
372 bool called_by_wait; // meaningful when !is_wait
373 uint32_t * bits;
374
375 public:
376 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
377 uint32_t *_bits) {
378 jt = _jt;
379 is_wait = _is_wait;
380 called_by_wait = _called_by_wait;
381 bits = _bits;
382 }
383
384 ~TraceSuspendDebugBits() {
385 if (!is_wait) {
386 #if 1
387 // By default, don't trace bits for is_ext_suspend_completed() calls.
388 // That trace is very chatty.
389 return;
390 #else
391 if (!called_by_wait) {
392 // If tracing for is_ext_suspend_completed() is enabled, then only
393 // trace calls to it from wait_for_ext_suspend_completion()
394 return;
395 }
396 #endif
397 }
398
399 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
400 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
401 MutexLocker ml(Threads_lock); // needed for get_thread_name()
402 ResourceMark rm;
403
404 tty->print_cr(
405 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
406 jt->get_thread_name(), *bits);
407
408 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
409 }
410 }
411 }
412 };
413 #undef DEBUG_FALSE_BITS
414
415
416 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
417 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
418
419 bool did_trans_retry = false; // only do thread_in_native_trans retry once
420 bool do_trans_retry; // flag to force the retry
421
422 *bits |= 0x00000001;
423
424 do {
425 do_trans_retry = false;
426
427 if (is_exiting()) {
428 // Thread is in the process of exiting. This is always checked
429 // first to reduce the risk of dereferencing a freed JavaThread.
430 *bits |= 0x00000100;
431 return false;
432 }
433
434 if (!is_external_suspend()) {
435 // Suspend request is cancelled. This is always checked before
436 // is_ext_suspended() to reduce the risk of a rogue resume
437 // confusing the thread that made the suspend request.
438 *bits |= 0x00000200;
439 return false;
440 }
441
442 if (is_ext_suspended()) {
443 // thread is suspended
444 *bits |= 0x00000400;
445 return true;
446 }
447
448 // Now that we no longer do hard suspends of threads running
449 // native code, the target thread can be changing thread state
450 // while we are in this routine:
451 //
452 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
453 //
454 // We save a copy of the thread state as observed at this moment
455 // and make our decision about suspend completeness based on the
456 // copy. This closes the race where the thread state is seen as
457 // _thread_in_native_trans in the if-thread_blocked check, but is
458 // seen as _thread_blocked in if-thread_in_native_trans check.
459 JavaThreadState save_state = thread_state();
460
461 if (save_state == _thread_blocked && is_suspend_equivalent()) {
462 // If the thread's state is _thread_blocked and this blocking
463 // condition is known to be equivalent to a suspend, then we can
464 // consider the thread to be externally suspended. This means that
465 // the code that sets _thread_blocked has been modified to do
466 // self-suspension if the blocking condition releases. We also
467 // used to check for CONDVAR_WAIT here, but that is now covered by
468 // the _thread_blocked with self-suspension check.
469 //
470 // Return true since we wouldn't be here unless there was still an
471 // external suspend request.
472 *bits |= 0x00001000;
473 return true;
474 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
475 // Threads running native code will self-suspend on native==>VM/Java
476 // transitions. If its stack is walkable (should always be the case
477 // unless this function is called before the actual java_suspend()
478 // call), then the wait is done.
479 *bits |= 0x00002000;
480 return true;
481 } else if (!called_by_wait && !did_trans_retry &&
482 save_state == _thread_in_native_trans &&
483 frame_anchor()->walkable()) {
484 // The thread is transitioning from thread_in_native to another
485 // thread state. check_safepoint_and_suspend_for_native_trans()
486 // will force the thread to self-suspend. If it hasn't gotten
487 // there yet we may have caught the thread in-between the native
488 // code check above and the self-suspend. Lucky us. If we were
489 // called by wait_for_ext_suspend_completion(), then it
490 // will be doing the retries so we don't have to.
491 //
492 // Since we use the saved thread state in the if-statement above,
493 // there is a chance that the thread has already transitioned to
494 // _thread_blocked by the time we get here. In that case, we will
495 // make a single unnecessary pass through the logic below. This
496 // doesn't hurt anything since we still do the trans retry.
497
498 *bits |= 0x00004000;
499
500 // Once the thread leaves thread_in_native_trans for another
501 // thread state, we break out of this retry loop. We shouldn't
502 // need this flag to prevent us from getting back here, but
503 // sometimes paranoia is good.
504 did_trans_retry = true;
505
506 // We wait for the thread to transition to a more usable state.
507 for (int i = 1; i <= SuspendRetryCount; i++) {
508 // We used to do an "os::yield_all(i)" call here with the intention
509 // that yielding would increase on each retry. However, the parameter
510 // is ignored on Linux which means the yield didn't scale up. Waiting
511 // on the SR_lock below provides a much more predictable scale up for
512 // the delay. It also provides a simple/direct point to check for any
513 // safepoint requests from the VMThread
514
515 // temporarily drops SR_lock while doing wait with safepoint check
516 // (if we're a JavaThread - the WatcherThread can also call this)
517 // and increase delay with each retry
518 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
519
520 // check the actual thread state instead of what we saved above
521 if (thread_state() != _thread_in_native_trans) {
522 // the thread has transitioned to another thread state so
523 // try all the checks (except this one) one more time.
524 do_trans_retry = true;
525 break;
526 }
527 } // end retry loop
528
529
530 }
531 } while (do_trans_retry);
532
533 *bits |= 0x00000010;
534 return false;
535 }
536
537 //
538 // Wait for an external suspend request to complete (or be cancelled).
539 // Returns true if the thread is externally suspended and false otherwise.
540 //
541 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
542 uint32_t *bits) {
543 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
544 false /* !called_by_wait */, bits);
545
546 // local flag copies to minimize SR_lock hold time
547 bool is_suspended;
548 bool pending;
549 uint32_t reset_bits;
550
551 // set a marker so is_ext_suspend_completed() knows we are the caller
552 *bits |= 0x00010000;
553
554 // We use reset_bits to reinitialize the bits value at the top of
555 // each retry loop. This allows the caller to make use of any
556 // unused bits for their own marking purposes.
557 reset_bits = *bits;
558
559 {
560 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
561 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
562 delay, bits);
563 pending = is_external_suspend();
564 }
565 // must release SR_lock to allow suspension to complete
566
567 if (!pending) {
568 // A cancelled suspend request is the only false return from
569 // is_ext_suspend_completed() that keeps us from entering the
570 // retry loop.
571 *bits |= 0x00020000;
572 return false;
573 }
574
575 if (is_suspended) {
576 *bits |= 0x00040000;
577 return true;
578 }
579
580 for (int i = 1; i <= retries; i++) {
581 *bits = reset_bits; // reinit to only track last retry
582
583 // We used to do an "os::yield_all(i)" call here with the intention
584 // that yielding would increase on each retry. However, the parameter
585 // is ignored on Linux which means the yield didn't scale up. Waiting
586 // on the SR_lock below provides a much more predictable scale up for
587 // the delay. It also provides a simple/direct point to check for any
588 // safepoint requests from the VMThread
589
590 {
591 MutexLocker ml(SR_lock());
592 // wait with safepoint check (if we're a JavaThread - the WatcherThread
593 // can also call this) and increase delay with each retry
594 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
595
596 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
597 delay, bits);
598
599 // It is possible for the external suspend request to be cancelled
600 // (by a resume) before the actual suspend operation is completed.
601 // Refresh our local copy to see if we still need to wait.
602 pending = is_external_suspend();
603 }
604
605 if (!pending) {
606 // A cancelled suspend request is the only false return from
607 // is_ext_suspend_completed() that keeps us from staying in the
608 // retry loop.
609 *bits |= 0x00080000;
610 return false;
611 }
612
613 if (is_suspended) {
614 *bits |= 0x00100000;
615 return true;
616 }
617 } // end retry loop
618
619 // thread did not suspend after all our retries
620 *bits |= 0x00200000;
621 return false;
622 }
623
624 #ifndef PRODUCT
625 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
626
627 // This should not need to be atomic as the only way for simultaneous
628 // updates is via interrupts. Even then this should be rare or non-existant
629 // and we don't care that much anyway.
630
631 int index = _jmp_ring_index;
632 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
633 _jmp_ring[index]._target = (intptr_t) target;
634 _jmp_ring[index]._instruction = (intptr_t) instr;
635 _jmp_ring[index]._file = file;
636 _jmp_ring[index]._line = line;
637 }
638 #endif /* PRODUCT */
639
640 // Called by flat profiler
641 // Callers have already called wait_for_ext_suspend_completion
642 // The assertion for that is currently too complex to put here:
643 bool JavaThread::profile_last_Java_frame(frame* _fr) {
644 bool gotframe = false;
645 // self suspension saves needed state.
646 if (has_last_Java_frame() && _anchor.walkable()) {
647 *_fr = pd_last_frame();
648 gotframe = true;
649 }
650 return gotframe;
651 }
652
653 void Thread::interrupt(Thread* thread) {
654 trace("interrupt", thread);
655 debug_only(check_for_dangling_thread_pointer(thread);)
656 os::interrupt(thread);
657 }
658
659 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
660 trace("is_interrupted", thread);
661 debug_only(check_for_dangling_thread_pointer(thread);)
662 // Note: If clear_interrupted==false, this simply fetches and
663 // returns the value of the field osthread()->interrupted().
664 return os::is_interrupted(thread, clear_interrupted);
665 }
666
667
668 // GC Support
669 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
670 jint thread_parity = _oops_do_parity;
671 if (thread_parity != strong_roots_parity) {
672 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
673 if (res == thread_parity) return true;
674 else {
675 guarantee(res == strong_roots_parity, "Or else what?");
676 assert(SharedHeap::heap()->n_par_threads() > 0,
677 "Should only fail when parallel.");
678 return false;
679 }
680 }
681 assert(SharedHeap::heap()->n_par_threads() > 0,
682 "Should only fail when parallel.");
683 return false;
684 }
685
686 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
687 active_handles()->oops_do(f);
688 // Do oop for ThreadShadow
689 f->do_oop((oop*)&_pending_exception);
690 handle_area()->oops_do(f);
691 }
692
693 void Thread::nmethods_do(CodeBlobClosure* cf) {
694 // no nmethods in a generic thread...
695 }
696
697 void Thread::print_on(outputStream* st) const {
698 // get_priority assumes osthread initialized
699 if (osthread() != NULL) {
700 st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this);
701 osthread()->print_on(st);
702 }
703 debug_only(if (WizardMode) print_owned_locks_on(st);)
704 }
705
706 // Thread::print_on_error() is called by fatal error handler. Don't use
707 // any lock or allocate memory.
708 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
709 if (is_VM_thread()) st->print("VMThread");
710 else if (is_Compiler_thread()) st->print("CompilerThread");
711 else if (is_Java_thread()) st->print("JavaThread");
712 else if (is_GC_task_thread()) st->print("GCTaskThread");
713 else if (is_Watcher_thread()) st->print("WatcherThread");
714 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
715 else st->print("Thread");
716
717 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
718 _stack_base - _stack_size, _stack_base);
719
720 if (osthread()) {
721 st->print(" [id=%d]", osthread()->thread_id());
722 }
723 }
724
725 #ifdef ASSERT
726 void Thread::print_owned_locks_on(outputStream* st) const {
727 Monitor *cur = _owned_locks;
728 if (cur == NULL) {
729 st->print(" (no locks) ");
730 } else {
731 st->print_cr(" Locks owned:");
732 while(cur) {
733 cur->print_on(st);
734 cur = cur->next();
735 }
736 }
737 }
738
739 static int ref_use_count = 0;
740
741 bool Thread::owns_locks_but_compiled_lock() const {
742 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
743 if (cur != Compile_lock) return true;
744 }
745 return false;
746 }
747
748
749 #endif
750
751 #ifndef PRODUCT
752
753 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
754 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
755 // no threads which allow_vm_block's are held
756 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
757 // Check if current thread is allowed to block at a safepoint
758 if (!(_allow_safepoint_count == 0))
759 fatal("Possible safepoint reached by thread that does not allow it");
760 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
761 fatal("LEAF method calling lock?");
762 }
763
764 #ifdef ASSERT
765 if (potential_vm_operation && is_Java_thread()
766 && !Universe::is_bootstrapping()) {
767 // Make sure we do not hold any locks that the VM thread also uses.
768 // This could potentially lead to deadlocks
769 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
770 // Threads_lock is special, since the safepoint synchronization will not start before this is
771 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
772 // since it is used to transfer control between JavaThreads and the VMThread
773 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
774 if ( (cur->allow_vm_block() &&
775 cur != Threads_lock &&
776 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
777 cur != VMOperationRequest_lock &&
778 cur != VMOperationQueue_lock) ||
779 cur->rank() == Mutex::special) {
780 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
781 }
782 }
783 }
784
785 if (GCALotAtAllSafepoints) {
786 // We could enter a safepoint here and thus have a gc
787 InterfaceSupport::check_gc_alot();
788 }
789 #endif
790 }
791 #endif
792
793 bool Thread::is_in_stack(address adr) const {
794 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
795 address end = os::current_stack_pointer();
796 if (stack_base() >= adr && adr >= end) return true;
797
798 return false;
799 }
800
801
802 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
803 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
804 // used for compilation in the future. If that change is made, the need for these methods
805 // should be revisited, and they should be removed if possible.
806
807 bool Thread::is_lock_owned(address adr) const {
808 return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
809 }
810
811 bool Thread::set_as_starting_thread() {
812 // NOTE: this must be called inside the main thread.
813 return os::create_main_thread((JavaThread*)this);
814 }
815
816 static void initialize_class(symbolHandle class_name, TRAPS) {
817 klassOop klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
818 instanceKlass::cast(klass)->initialize(CHECK);
819 }
820
821
822 // Creates the initial ThreadGroup
823 static Handle create_initial_thread_group(TRAPS) {
824 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH);
825 instanceKlassHandle klass (THREAD, k);
826
827 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
828 {
829 JavaValue result(T_VOID);
830 JavaCalls::call_special(&result,
831 system_instance,
832 klass,
833 vmSymbolHandles::object_initializer_name(),
834 vmSymbolHandles::void_method_signature(),
835 CHECK_NH);
836 }
837 Universe::set_system_thread_group(system_instance());
838
839 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
840 {
841 JavaValue result(T_VOID);
842 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
843 JavaCalls::call_special(&result,
844 main_instance,
845 klass,
846 vmSymbolHandles::object_initializer_name(),
847 vmSymbolHandles::threadgroup_string_void_signature(),
848 system_instance,
849 string,
850 CHECK_NH);
851 }
852 return main_instance;
853 }
854
855 // Creates the initial Thread
856 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
857 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL);
858 instanceKlassHandle klass (THREAD, k);
859 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
860
861 java_lang_Thread::set_thread(thread_oop(), thread);
862 java_lang_Thread::set_priority(thread_oop(), NormPriority);
863 thread->set_threadObj(thread_oop());
864
865 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
866
867 JavaValue result(T_VOID);
868 JavaCalls::call_special(&result, thread_oop,
869 klass,
870 vmSymbolHandles::object_initializer_name(),
871 vmSymbolHandles::threadgroup_string_void_signature(),
872 thread_group,
873 string,
874 CHECK_NULL);
875 return thread_oop();
876 }
877
878 static void call_initializeSystemClass(TRAPS) {
879 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
880 instanceKlassHandle klass (THREAD, k);
881
882 JavaValue result(T_VOID);
883 JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(),
884 vmSymbolHandles::void_method_signature(), CHECK);
885 }
886
887 #ifdef KERNEL
888 static void set_jkernel_boot_classloader_hook(TRAPS) {
889 klassOop k = SystemDictionary::sun_jkernel_DownloadManager_klass();
890 instanceKlassHandle klass (THREAD, k);
891
892 if (k == NULL) {
893 // sun.jkernel.DownloadManager may not present in the JDK; just return
894 return;
895 }
896
897 JavaValue result(T_VOID);
898 JavaCalls::call_static(&result, klass, vmSymbolHandles::setBootClassLoaderHook_name(),
899 vmSymbolHandles::void_method_signature(), CHECK);
900 }
901 #endif // KERNEL
902
903 static void reset_vm_info_property(TRAPS) {
904 // the vm info string
905 ResourceMark rm(THREAD);
906 const char *vm_info = VM_Version::vm_info_string();
907
908 // java.lang.System class
909 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
910 instanceKlassHandle klass (THREAD, k);
911
912 // setProperty arguments
913 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
914 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
915
916 // return value
917 JavaValue r(T_OBJECT);
918
919 // public static String setProperty(String key, String value);
920 JavaCalls::call_static(&r,
921 klass,
922 vmSymbolHandles::setProperty_name(),
923 vmSymbolHandles::string_string_string_signature(),
924 key_str,
925 value_str,
926 CHECK);
927 }
928
929
930 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
931 assert(thread_group.not_null(), "thread group should be specified");
932 assert(threadObj() == NULL, "should only create Java thread object once");
933
934 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
935 instanceKlassHandle klass (THREAD, k);
936 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
937
938 java_lang_Thread::set_thread(thread_oop(), this);
939 java_lang_Thread::set_priority(thread_oop(), NormPriority);
940 set_threadObj(thread_oop());
941
942 JavaValue result(T_VOID);
943 if (thread_name != NULL) {
944 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
945 // Thread gets assigned specified name and null target
946 JavaCalls::call_special(&result,
947 thread_oop,
948 klass,
949 vmSymbolHandles::object_initializer_name(),
950 vmSymbolHandles::threadgroup_string_void_signature(),
951 thread_group, // Argument 1
952 name, // Argument 2
953 THREAD);
954 } else {
955 // Thread gets assigned name "Thread-nnn" and null target
956 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
957 JavaCalls::call_special(&result,
958 thread_oop,
959 klass,
960 vmSymbolHandles::object_initializer_name(),
961 vmSymbolHandles::threadgroup_runnable_void_signature(),
962 thread_group, // Argument 1
963 Handle(), // Argument 2
964 THREAD);
965 }
966
967
968 if (daemon) {
969 java_lang_Thread::set_daemon(thread_oop());
970 }
971
972 if (HAS_PENDING_EXCEPTION) {
973 return;
974 }
975
976 KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
977 Handle threadObj(this, this->threadObj());
978
979 JavaCalls::call_special(&result,
980 thread_group,
981 group,
982 vmSymbolHandles::add_method_name(),
983 vmSymbolHandles::thread_void_signature(),
984 threadObj, // Arg 1
985 THREAD);
986
987
988 }
989
990 // NamedThread -- non-JavaThread subclasses with multiple
991 // uniquely named instances should derive from this.
992 NamedThread::NamedThread() : Thread() {
993 _name = NULL;
994 _processed_thread = NULL;
995 }
996
997 NamedThread::~NamedThread() {
998 if (_name != NULL) {
999 FREE_C_HEAP_ARRAY(char, _name);
1000 _name = NULL;
1001 }
1002 }
1003
1004 void NamedThread::set_name(const char* format, ...) {
1005 guarantee(_name == NULL, "Only get to set name once.");
1006 _name = NEW_C_HEAP_ARRAY(char, max_name_len);
1007 guarantee(_name != NULL, "alloc failure");
1008 va_list ap;
1009 va_start(ap, format);
1010 jio_vsnprintf(_name, max_name_len, format, ap);
1011 va_end(ap);
1012 }
1013
1014 // ======= WatcherThread ========
1015
1016 // The watcher thread exists to simulate timer interrupts. It should
1017 // be replaced by an abstraction over whatever native support for
1018 // timer interrupts exists on the platform.
1019
1020 WatcherThread* WatcherThread::_watcher_thread = NULL;
1021 bool WatcherThread::_should_terminate = false;
1022
1023 WatcherThread::WatcherThread() : Thread() {
1024 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1025 if (os::create_thread(this, os::watcher_thread)) {
1026 _watcher_thread = this;
1027
1028 // Set the watcher thread to the highest OS priority which should not be
1029 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1030 // is created. The only normal thread using this priority is the reference
1031 // handler thread, which runs for very short intervals only.
1032 // If the VMThread's priority is not lower than the WatcherThread profiling
1033 // will be inaccurate.
1034 os::set_priority(this, MaxPriority);
1035 if (!DisableStartThread) {
1036 os::start_thread(this);
1037 }
1038 }
1039 }
1040
1041 void WatcherThread::run() {
1042 assert(this == watcher_thread(), "just checking");
1043
1044 this->record_stack_base_and_size();
1045 this->initialize_thread_local_storage();
1046 this->set_active_handles(JNIHandleBlock::allocate_block());
1047 while(!_should_terminate) {
1048 assert(watcher_thread() == Thread::current(), "thread consistency check");
1049 assert(watcher_thread() == this, "thread consistency check");
1050
1051 // Calculate how long it'll be until the next PeriodicTask work
1052 // should be done, and sleep that amount of time.
1053 const size_t time_to_wait = PeriodicTask::time_to_wait();
1054 os::sleep(this, time_to_wait, false);
1055
1056 if (is_error_reported()) {
1057 // A fatal error has happened, the error handler(VMError::report_and_die)
1058 // should abort JVM after creating an error log file. However in some
1059 // rare cases, the error handler itself might deadlock. Here we try to
1060 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1061 //
1062 // This code is in WatcherThread because WatcherThread wakes up
1063 // periodically so the fatal error handler doesn't need to do anything;
1064 // also because the WatcherThread is less likely to crash than other
1065 // threads.
1066
1067 for (;;) {
1068 if (!ShowMessageBoxOnError
1069 && (OnError == NULL || OnError[0] == '\0')
1070 && Arguments::abort_hook() == NULL) {
1071 os::sleep(this, 2 * 60 * 1000, false);
1072 fdStream err(defaultStream::output_fd());
1073 err.print_raw_cr("# [ timer expired, abort... ]");
1074 // skip atexit/vm_exit/vm_abort hooks
1075 os::die();
1076 }
1077
1078 // Wake up 5 seconds later, the fatal handler may reset OnError or
1079 // ShowMessageBoxOnError when it is ready to abort.
1080 os::sleep(this, 5 * 1000, false);
1081 }
1082 }
1083
1084 PeriodicTask::real_time_tick(time_to_wait);
1085
1086 // If we have no more tasks left due to dynamic disenrollment,
1087 // shut down the thread since we don't currently support dynamic enrollment
1088 if (PeriodicTask::num_tasks() == 0) {
1089 _should_terminate = true;
1090 }
1091 }
1092
1093 // Signal that it is terminated
1094 {
1095 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1096 _watcher_thread = NULL;
1097 Terminator_lock->notify();
1098 }
1099
1100 // Thread destructor usually does this..
1101 ThreadLocalStorage::set_thread(NULL);
1102 }
1103
1104 void WatcherThread::start() {
1105 if (watcher_thread() == NULL) {
1106 _should_terminate = false;
1107 // Create the single instance of WatcherThread
1108 new WatcherThread();
1109 }
1110 }
1111
1112 void WatcherThread::stop() {
1113 // it is ok to take late safepoints here, if needed
1114 MutexLocker mu(Terminator_lock);
1115 _should_terminate = true;
1116 while(watcher_thread() != NULL) {
1117 // This wait should make safepoint checks, wait without a timeout,
1118 // and wait as a suspend-equivalent condition.
1119 //
1120 // Note: If the FlatProfiler is running, then this thread is waiting
1121 // for the WatcherThread to terminate and the WatcherThread, via the
1122 // FlatProfiler task, is waiting for the external suspend request on
1123 // this thread to complete. wait_for_ext_suspend_completion() will
1124 // eventually timeout, but that takes time. Making this wait a
1125 // suspend-equivalent condition solves that timeout problem.
1126 //
1127 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1128 Mutex::_as_suspend_equivalent_flag);
1129 }
1130 }
1131
1132 void WatcherThread::print_on(outputStream* st) const {
1133 st->print("\"%s\" ", name());
1134 Thread::print_on(st);
1135 st->cr();
1136 }
1137
1138 // ======= JavaThread ========
1139
1140 // A JavaThread is a normal Java thread
1141
1142 void JavaThread::initialize() {
1143 // Initialize fields
1144
1145 // Set the claimed par_id to -1 (ie not claiming any par_ids)
1146 set_claimed_par_id(-1);
1147
1148 set_saved_exception_pc(NULL);
1149 set_threadObj(NULL);
1150 _anchor.clear();
1151 set_entry_point(NULL);
1152 set_jni_functions(jni_functions());
1153 set_callee_target(NULL);
1154 set_vm_result(NULL);
1155 set_vm_result_2(NULL);
1156 set_vframe_array_head(NULL);
1157 set_vframe_array_last(NULL);
1158 set_deferred_locals(NULL);
1159 set_deopt_mark(NULL);
1160 clear_must_deopt_id();
1161 set_monitor_chunks(NULL);
1162 set_next(NULL);
1163 set_thread_state(_thread_new);
1164 _terminated = _not_terminated;
1165 _privileged_stack_top = NULL;
1166 _array_for_gc = NULL;
1167 _suspend_equivalent = false;
1168 _in_deopt_handler = 0;
1169 _doing_unsafe_access = false;
1170 _stack_guard_state = stack_guard_unused;
1171 _exception_oop = NULL;
1172 _exception_pc = 0;
1173 _exception_handler_pc = 0;
1174 _exception_stack_size = 0;
1175 _jvmti_thread_state= NULL;
1176 _should_post_on_exceptions_flag = JNI_FALSE;
1177 _jvmti_get_loaded_classes_closure = NULL;
1178 _interp_only_mode = 0;
1179 _special_runtime_exit_condition = _no_async_condition;
1180 _pending_async_exception = NULL;
1181 _is_compiling = false;
1182 _thread_stat = NULL;
1183 _thread_stat = new ThreadStatistics();
1184 _blocked_on_compilation = false;
1185 _jni_active_critical = 0;
1186 _do_not_unlock_if_synchronized = false;
1187 _cached_monitor_info = NULL;
1188 _parker = Parker::Allocate(this) ;
1189
1190 #ifndef PRODUCT
1191 _jmp_ring_index = 0;
1192 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1193 record_jump(NULL, NULL, NULL, 0);
1194 }
1195 #endif /* PRODUCT */
1196
1197 set_thread_profiler(NULL);
1198 if (FlatProfiler::is_active()) {
1199 // This is where we would decide to either give each thread it's own profiler
1200 // or use one global one from FlatProfiler,
1201 // or up to some count of the number of profiled threads, etc.
1202 ThreadProfiler* pp = new ThreadProfiler();
1203 pp->engage();
1204 set_thread_profiler(pp);
1205 }
1206
1207 // Setup safepoint state info for this thread
1208 ThreadSafepointState::create(this);
1209
1210 debug_only(_java_call_counter = 0);
1211
1212 // JVMTI PopFrame support
1213 _popframe_condition = popframe_inactive;
1214 _popframe_preserved_args = NULL;
1215 _popframe_preserved_args_size = 0;
1216
1217 pd_initialize();
1218 }
1219
1220 #ifndef SERIALGC
1221 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1222 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1223 #endif // !SERIALGC
1224
1225 JavaThread::JavaThread(bool is_attaching) :
1226 Thread()
1227 #ifndef SERIALGC
1228 , _satb_mark_queue(&_satb_mark_queue_set),
1229 _dirty_card_queue(&_dirty_card_queue_set)
1230 #endif // !SERIALGC
1231 {
1232 initialize();
1233 _is_attaching = is_attaching;
1234 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor");
1235 }
1236
1237 bool JavaThread::reguard_stack(address cur_sp) {
1238 if (_stack_guard_state != stack_guard_yellow_disabled) {
1239 return true; // Stack already guarded or guard pages not needed.
1240 }
1241
1242 if (register_stack_overflow()) {
1243 // For those architectures which have separate register and
1244 // memory stacks, we must check the register stack to see if
1245 // it has overflowed.
1246 return false;
1247 }
1248
1249 // Java code never executes within the yellow zone: the latter is only
1250 // there to provoke an exception during stack banging. If java code
1251 // is executing there, either StackShadowPages should be larger, or
1252 // some exception code in c1, c2 or the interpreter isn't unwinding
1253 // when it should.
1254 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1255
1256 enable_stack_yellow_zone();
1257 return true;
1258 }
1259
1260 bool JavaThread::reguard_stack(void) {
1261 return reguard_stack(os::current_stack_pointer());
1262 }
1263
1264
1265 void JavaThread::block_if_vm_exited() {
1266 if (_terminated == _vm_exited) {
1267 // _vm_exited is set at safepoint, and Threads_lock is never released
1268 // we will block here forever
1269 Threads_lock->lock_without_safepoint_check();
1270 ShouldNotReachHere();
1271 }
1272 }
1273
1274
1275 // Remove this ifdef when C1 is ported to the compiler interface.
1276 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1277
1278 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1279 Thread()
1280 #ifndef SERIALGC
1281 , _satb_mark_queue(&_satb_mark_queue_set),
1282 _dirty_card_queue(&_dirty_card_queue_set)
1283 #endif // !SERIALGC
1284 {
1285 if (TraceThreadEvents) {
1286 tty->print_cr("creating thread %p", this);
1287 }
1288 initialize();
1289 _is_attaching = false;
1290 set_entry_point(entry_point);
1291 // Create the native thread itself.
1292 // %note runtime_23
1293 os::ThreadType thr_type = os::java_thread;
1294 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1295 os::java_thread;
1296 os::create_thread(this, thr_type, stack_sz);
1297
1298 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1299 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1300 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1301 // the exception consists of creating the exception object & initializing it, initialization
1302 // will leave the VM via a JavaCall and then all locks must be unlocked).
1303 //
1304 // The thread is still suspended when we reach here. Thread must be explicit started
1305 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1306 // by calling Threads:add. The reason why this is not done here, is because the thread
1307 // object must be fully initialized (take a look at JVM_Start)
1308 }
1309
1310 JavaThread::~JavaThread() {
1311 if (TraceThreadEvents) {
1312 tty->print_cr("terminate thread %p", this);
1313 }
1314
1315 // JSR166 -- return the parker to the free list
1316 Parker::Release(_parker);
1317 _parker = NULL ;
1318
1319 // Free any remaining previous UnrollBlock
1320 vframeArray* old_array = vframe_array_last();
1321
1322 if (old_array != NULL) {
1323 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1324 old_array->set_unroll_block(NULL);
1325 delete old_info;
1326 delete old_array;
1327 }
1328
1329 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1330 if (deferred != NULL) {
1331 // This can only happen if thread is destroyed before deoptimization occurs.
1332 assert(deferred->length() != 0, "empty array!");
1333 do {
1334 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1335 deferred->remove_at(0);
1336 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1337 delete dlv;
1338 } while (deferred->length() != 0);
1339 delete deferred;
1340 }
1341
1342 // All Java related clean up happens in exit
1343 ThreadSafepointState::destroy(this);
1344 if (_thread_profiler != NULL) delete _thread_profiler;
1345 if (_thread_stat != NULL) delete _thread_stat;
1346 }
1347
1348
1349 // The first routine called by a new Java thread
1350 void JavaThread::run() {
1351 // initialize thread-local alloc buffer related fields
1352 this->initialize_tlab();
1353
1354 // used to test validitity of stack trace backs
1355 this->record_base_of_stack_pointer();
1356
1357 // Record real stack base and size.
1358 this->record_stack_base_and_size();
1359
1360 // Initialize thread local storage; set before calling MutexLocker
1361 this->initialize_thread_local_storage();
1362
1363 this->create_stack_guard_pages();
1364
1365 // Thread is now sufficient initialized to be handled by the safepoint code as being
1366 // in the VM. Change thread state from _thread_new to _thread_in_vm
1367 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1368
1369 assert(JavaThread::current() == this, "sanity check");
1370 assert(!Thread::current()->owns_locks(), "sanity check");
1371
1372 DTRACE_THREAD_PROBE(start, this);
1373
1374 // This operation might block. We call that after all safepoint checks for a new thread has
1375 // been completed.
1376 this->set_active_handles(JNIHandleBlock::allocate_block());
1377
1378 if (JvmtiExport::should_post_thread_life()) {
1379 JvmtiExport::post_thread_start(this);
1380 }
1381
1382 // We call another function to do the rest so we are sure that the stack addresses used
1383 // from there will be lower than the stack base just computed
1384 thread_main_inner();
1385
1386 // Note, thread is no longer valid at this point!
1387 }
1388
1389
1390 void JavaThread::thread_main_inner() {
1391 assert(JavaThread::current() == this, "sanity check");
1392 assert(this->threadObj() != NULL, "just checking");
1393
1394 // Execute thread entry point. If this thread is being asked to restart,
1395 // or has been stopped before starting, do not reexecute entry point.
1396 // Note: Due to JVM_StopThread we can have pending exceptions already!
1397 if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) {
1398 // enter the thread's entry point only if we have no pending exceptions
1399 HandleMark hm(this);
1400 this->entry_point()(this, this);
1401 }
1402
1403 DTRACE_THREAD_PROBE(stop, this);
1404
1405 this->exit(false);
1406 delete this;
1407 }
1408
1409
1410 static void ensure_join(JavaThread* thread) {
1411 // We do not need to grap the Threads_lock, since we are operating on ourself.
1412 Handle threadObj(thread, thread->threadObj());
1413 assert(threadObj.not_null(), "java thread object must exist");
1414 ObjectLocker lock(threadObj, thread);
1415 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1416 thread->clear_pending_exception();
1417 // It is of profound importance that we set the stillborn bit and reset the thread object,
1418 // before we do the notify. Since, changing these two variable will make JVM_IsAlive return
1419 // false. So in case another thread is doing a join on this thread , it will detect that the thread
1420 // is dead when it gets notified.
1421 java_lang_Thread::set_stillborn(threadObj());
1422 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1423 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1424 java_lang_Thread::set_thread(threadObj(), NULL);
1425 lock.notify_all(thread);
1426 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1427 thread->clear_pending_exception();
1428 }
1429
1430
1431 // For any new cleanup additions, please check to see if they need to be applied to
1432 // cleanup_failed_attach_current_thread as well.
1433 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1434 assert(this == JavaThread::current(), "thread consistency check");
1435 if (!InitializeJavaLangSystem) return;
1436
1437 HandleMark hm(this);
1438 Handle uncaught_exception(this, this->pending_exception());
1439 this->clear_pending_exception();
1440 Handle threadObj(this, this->threadObj());
1441 assert(threadObj.not_null(), "Java thread object should be created");
1442
1443 if (get_thread_profiler() != NULL) {
1444 get_thread_profiler()->disengage();
1445 ResourceMark rm;
1446 get_thread_profiler()->print(get_thread_name());
1447 }
1448
1449
1450 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1451 {
1452 EXCEPTION_MARK;
1453
1454 CLEAR_PENDING_EXCEPTION;
1455 }
1456 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1457 // has to be fixed by a runtime query method
1458 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1459 // JSR-166: change call from from ThreadGroup.uncaughtException to
1460 // java.lang.Thread.dispatchUncaughtException
1461 if (uncaught_exception.not_null()) {
1462 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1463 Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT",
1464 (address)uncaught_exception(), (address)threadObj(), (address)group());
1465 {
1466 EXCEPTION_MARK;
1467 // Check if the method Thread.dispatchUncaughtException() exists. If so
1468 // call it. Otherwise we have an older library without the JSR-166 changes,
1469 // so call ThreadGroup.uncaughtException()
1470 KlassHandle recvrKlass(THREAD, threadObj->klass());
1471 CallInfo callinfo;
1472 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1473 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1474 vmSymbolHandles::dispatchUncaughtException_name(),
1475 vmSymbolHandles::throwable_void_signature(),
1476 KlassHandle(), false, false, THREAD);
1477 CLEAR_PENDING_EXCEPTION;
1478 methodHandle method = callinfo.selected_method();
1479 if (method.not_null()) {
1480 JavaValue result(T_VOID);
1481 JavaCalls::call_virtual(&result,
1482 threadObj, thread_klass,
1483 vmSymbolHandles::dispatchUncaughtException_name(),
1484 vmSymbolHandles::throwable_void_signature(),
1485 uncaught_exception,
1486 THREAD);
1487 } else {
1488 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1489 JavaValue result(T_VOID);
1490 JavaCalls::call_virtual(&result,
1491 group, thread_group,
1492 vmSymbolHandles::uncaughtException_name(),
1493 vmSymbolHandles::thread_throwable_void_signature(),
1494 threadObj, // Arg 1
1495 uncaught_exception, // Arg 2
1496 THREAD);
1497 }
1498 CLEAR_PENDING_EXCEPTION;
1499 }
1500 }
1501
1502 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1503 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1504 // is deprecated anyhow.
1505 { int count = 3;
1506 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1507 EXCEPTION_MARK;
1508 JavaValue result(T_VOID);
1509 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1510 JavaCalls::call_virtual(&result,
1511 threadObj, thread_klass,
1512 vmSymbolHandles::exit_method_name(),
1513 vmSymbolHandles::void_method_signature(),
1514 THREAD);
1515 CLEAR_PENDING_EXCEPTION;
1516 }
1517 }
1518
1519 // notify JVMTI
1520 if (JvmtiExport::should_post_thread_life()) {
1521 JvmtiExport::post_thread_end(this);
1522 }
1523
1524 // We have notified the agents that we are exiting, before we go on,
1525 // we must check for a pending external suspend request and honor it
1526 // in order to not surprise the thread that made the suspend request.
1527 while (true) {
1528 {
1529 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1530 if (!is_external_suspend()) {
1531 set_terminated(_thread_exiting);
1532 ThreadService::current_thread_exiting(this);
1533 break;
1534 }
1535 // Implied else:
1536 // Things get a little tricky here. We have a pending external
1537 // suspend request, but we are holding the SR_lock so we
1538 // can't just self-suspend. So we temporarily drop the lock
1539 // and then self-suspend.
1540 }
1541
1542 ThreadBlockInVM tbivm(this);
1543 java_suspend_self();
1544
1545 // We're done with this suspend request, but we have to loop around
1546 // and check again. Eventually we will get SR_lock without a pending
1547 // external suspend request and will be able to mark ourselves as
1548 // exiting.
1549 }
1550 // no more external suspends are allowed at this point
1551 } else {
1552 // before_exit() has already posted JVMTI THREAD_END events
1553 }
1554
1555 // Notify waiters on thread object. This has to be done after exit() is called
1556 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1557 // group should have the destroyed bit set before waiters are notified).
1558 ensure_join(this);
1559 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1560
1561 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1562 // held by this thread must be released. A detach operation must only
1563 // get here if there are no Java frames on the stack. Therefore, any
1564 // owned monitors at this point MUST be JNI-acquired monitors which are
1565 // pre-inflated and in the monitor cache.
1566 //
1567 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1568 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1569 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1570 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1571 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1572 }
1573
1574 // These things needs to be done while we are still a Java Thread. Make sure that thread
1575 // is in a consistent state, in case GC happens
1576 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1577
1578 if (active_handles() != NULL) {
1579 JNIHandleBlock* block = active_handles();
1580 set_active_handles(NULL);
1581 JNIHandleBlock::release_block(block);
1582 }
1583
1584 if (free_handle_block() != NULL) {
1585 JNIHandleBlock* block = free_handle_block();
1586 set_free_handle_block(NULL);
1587 JNIHandleBlock::release_block(block);
1588 }
1589
1590 // These have to be removed while this is still a valid thread.
1591 remove_stack_guard_pages();
1592
1593 if (UseTLAB) {
1594 tlab().make_parsable(true); // retire TLAB
1595 }
1596
1597 if (jvmti_thread_state() != NULL) {
1598 JvmtiExport::cleanup_thread(this);
1599 }
1600
1601 #ifndef SERIALGC
1602 // We must flush G1-related buffers before removing a thread from
1603 // the list of active threads.
1604 if (UseG1GC) {
1605 flush_barrier_queues();
1606 }
1607 #endif
1608
1609 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1610 Threads::remove(this);
1611 }
1612
1613 #ifndef SERIALGC
1614 // Flush G1-related queues.
1615 void JavaThread::flush_barrier_queues() {
1616 satb_mark_queue().flush();
1617 dirty_card_queue().flush();
1618 }
1619 #endif
1620
1621 void JavaThread::cleanup_failed_attach_current_thread() {
1622 if (get_thread_profiler() != NULL) {
1623 get_thread_profiler()->disengage();
1624 ResourceMark rm;
1625 get_thread_profiler()->print(get_thread_name());
1626 }
1627
1628 if (active_handles() != NULL) {
1629 JNIHandleBlock* block = active_handles();
1630 set_active_handles(NULL);
1631 JNIHandleBlock::release_block(block);
1632 }
1633
1634 if (free_handle_block() != NULL) {
1635 JNIHandleBlock* block = free_handle_block();
1636 set_free_handle_block(NULL);
1637 JNIHandleBlock::release_block(block);
1638 }
1639
1640 if (UseTLAB) {
1641 tlab().make_parsable(true); // retire TLAB, if any
1642 }
1643
1644 #ifndef SERIALGC
1645 if (UseG1GC) {
1646 flush_barrier_queues();
1647 }
1648 #endif
1649
1650 Threads::remove(this);
1651 delete this;
1652 }
1653
1654
1655
1656
1657 JavaThread* JavaThread::active() {
1658 Thread* thread = ThreadLocalStorage::thread();
1659 assert(thread != NULL, "just checking");
1660 if (thread->is_Java_thread()) {
1661 return (JavaThread*) thread;
1662 } else {
1663 assert(thread->is_VM_thread(), "this must be a vm thread");
1664 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1665 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1666 assert(ret->is_Java_thread(), "must be a Java thread");
1667 return ret;
1668 }
1669 }
1670
1671 bool JavaThread::is_lock_owned(address adr) const {
1672 if (Thread::is_lock_owned(adr)) return true;
1673
1674 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1675 if (chunk->contains(adr)) return true;
1676 }
1677
1678 return false;
1679 }
1680
1681
1682 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1683 chunk->set_next(monitor_chunks());
1684 set_monitor_chunks(chunk);
1685 }
1686
1687 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1688 guarantee(monitor_chunks() != NULL, "must be non empty");
1689 if (monitor_chunks() == chunk) {
1690 set_monitor_chunks(chunk->next());
1691 } else {
1692 MonitorChunk* prev = monitor_chunks();
1693 while (prev->next() != chunk) prev = prev->next();
1694 prev->set_next(chunk->next());
1695 }
1696 }
1697
1698 // JVM support.
1699
1700 // Note: this function shouldn't block if it's called in
1701 // _thread_in_native_trans state (such as from
1702 // check_special_condition_for_native_trans()).
1703 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
1704
1705 if (has_last_Java_frame() && has_async_condition()) {
1706 // If we are at a polling page safepoint (not a poll return)
1707 // then we must defer async exception because live registers
1708 // will be clobbered by the exception path. Poll return is
1709 // ok because the call we a returning from already collides
1710 // with exception handling registers and so there is no issue.
1711 // (The exception handling path kills call result registers but
1712 // this is ok since the exception kills the result anyway).
1713
1714 if (is_at_poll_safepoint()) {
1715 // if the code we are returning to has deoptimized we must defer
1716 // the exception otherwise live registers get clobbered on the
1717 // exception path before deoptimization is able to retrieve them.
1718 //
1719 RegisterMap map(this, false);
1720 frame caller_fr = last_frame().sender(&map);
1721 assert(caller_fr.is_compiled_frame(), "what?");
1722 if (caller_fr.is_deoptimized_frame()) {
1723 if (TraceExceptions) {
1724 ResourceMark rm;
1725 tty->print_cr("deferred async exception at compiled safepoint");
1726 }
1727 return;
1728 }
1729 }
1730 }
1731
1732 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
1733 if (condition == _no_async_condition) {
1734 // Conditions have changed since has_special_runtime_exit_condition()
1735 // was called:
1736 // - if we were here only because of an external suspend request,
1737 // then that was taken care of above (or cancelled) so we are done
1738 // - if we were here because of another async request, then it has
1739 // been cleared between the has_special_runtime_exit_condition()
1740 // and now so again we are done
1741 return;
1742 }
1743
1744 // Check for pending async. exception
1745 if (_pending_async_exception != NULL) {
1746 // Only overwrite an already pending exception, if it is not a threadDeath.
1747 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
1748
1749 // We cannot call Exceptions::_throw(...) here because we cannot block
1750 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1751
1752 if (TraceExceptions) {
1753 ResourceMark rm;
1754 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
1755 if (has_last_Java_frame() ) {
1756 frame f = last_frame();
1757 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
1758 }
1759 tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1760 }
1761 _pending_async_exception = NULL;
1762 clear_has_async_exception();
1763 }
1764 }
1765
1766 if (check_unsafe_error &&
1767 condition == _async_unsafe_access_error && !has_pending_exception()) {
1768 condition = _no_async_condition; // done
1769 switch (thread_state()) {
1770 case _thread_in_vm:
1771 {
1772 JavaThread* THREAD = this;
1773 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1774 }
1775 case _thread_in_native:
1776 {
1777 ThreadInVMfromNative tiv(this);
1778 JavaThread* THREAD = this;
1779 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1780 }
1781 case _thread_in_Java:
1782 {
1783 ThreadInVMfromJava tiv(this);
1784 JavaThread* THREAD = this;
1785 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1786 }
1787 default:
1788 ShouldNotReachHere();
1789 }
1790 }
1791
1792 assert(condition == _no_async_condition || has_pending_exception() ||
1793 (!check_unsafe_error && condition == _async_unsafe_access_error),
1794 "must have handled the async condition, if no exception");
1795 }
1796
1797 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1798 //
1799 // Check for pending external suspend. Internal suspend requests do
1800 // not use handle_special_runtime_exit_condition().
1801 // If JNIEnv proxies are allowed, don't self-suspend if the target
1802 // thread is not the current thread. In older versions of jdbx, jdbx
1803 // threads could call into the VM with another thread's JNIEnv so we
1804 // can be here operating on behalf of a suspended thread (4432884).
1805 bool do_self_suspend = is_external_suspend_with_lock();
1806 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
1807 //
1808 // Because thread is external suspended the safepoint code will count
1809 // thread as at a safepoint. This can be odd because we can be here
1810 // as _thread_in_Java which would normally transition to _thread_blocked
1811 // at a safepoint. We would like to mark the thread as _thread_blocked
1812 // before calling java_suspend_self like all other callers of it but
1813 // we must then observe proper safepoint protocol. (We can't leave
1814 // _thread_blocked with a safepoint in progress). However we can be
1815 // here as _thread_in_native_trans so we can't use a normal transition
1816 // constructor/destructor pair because they assert on that type of
1817 // transition. We could do something like:
1818 //
1819 // JavaThreadState state = thread_state();
1820 // set_thread_state(_thread_in_vm);
1821 // {
1822 // ThreadBlockInVM tbivm(this);
1823 // java_suspend_self()
1824 // }
1825 // set_thread_state(_thread_in_vm_trans);
1826 // if (safepoint) block;
1827 // set_thread_state(state);
1828 //
1829 // but that is pretty messy. Instead we just go with the way the
1830 // code has worked before and note that this is the only path to
1831 // java_suspend_self that doesn't put the thread in _thread_blocked
1832 // mode.
1833
1834 frame_anchor()->make_walkable(this);
1835 java_suspend_self();
1836
1837 // We might be here for reasons in addition to the self-suspend request
1838 // so check for other async requests.
1839 }
1840
1841 if (check_asyncs) {
1842 check_and_handle_async_exceptions();
1843 }
1844 }
1845
1846 void JavaThread::send_thread_stop(oop java_throwable) {
1847 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
1848 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
1849 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1850
1851 // Do not throw asynchronous exceptions against the compiler thread
1852 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1853 if (is_Compiler_thread()) return;
1854
1855 // This is a change from JDK 1.1, but JDK 1.2 will also do it:
1856 if (java_throwable->is_a(SystemDictionary::ThreadDeath_klass())) {
1857 java_lang_Thread::set_stillborn(threadObj());
1858 }
1859
1860 {
1861 // Actually throw the Throwable against the target Thread - however
1862 // only if there is no thread death exception installed already.
1863 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
1864 // If the topmost frame is a runtime stub, then we are calling into
1865 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1866 // must deoptimize the caller before continuing, as the compiled exception handler table
1867 // may not be valid
1868 if (has_last_Java_frame()) {
1869 frame f = last_frame();
1870 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1871 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
1872 RegisterMap reg_map(this, UseBiasedLocking);
1873 frame compiled_frame = f.sender(®_map);
1874 if (compiled_frame.can_be_deoptimized()) {
1875 Deoptimization::deoptimize(this, compiled_frame, ®_map);
1876 }
1877 }
1878 }
1879
1880 // Set async. pending exception in thread.
1881 set_pending_async_exception(java_throwable);
1882
1883 if (TraceExceptions) {
1884 ResourceMark rm;
1885 tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1886 }
1887 // for AbortVMOnException flag
1888 NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name()));
1889 }
1890 }
1891
1892
1893 // Interrupt thread so it will wake up from a potential wait()
1894 Thread::interrupt(this);
1895 }
1896
1897 // External suspension mechanism.
1898 //
1899 // Tell the VM to suspend a thread when ever it knows that it does not hold on
1900 // to any VM_locks and it is at a transition
1901 // Self-suspension will happen on the transition out of the vm.
1902 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
1903 //
1904 // Guarantees on return:
1905 // + Target thread will not execute any new bytecode (that's why we need to
1906 // force a safepoint)
1907 // + Target thread will not enter any new monitors
1908 //
1909 void JavaThread::java_suspend() {
1910 { MutexLocker mu(Threads_lock);
1911 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
1912 return;
1913 }
1914 }
1915
1916 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1917 if (!is_external_suspend()) {
1918 // a racing resume has cancelled us; bail out now
1919 return;
1920 }
1921
1922 // suspend is done
1923 uint32_t debug_bits = 0;
1924 // Warning: is_ext_suspend_completed() may temporarily drop the
1925 // SR_lock to allow the thread to reach a stable thread state if
1926 // it is currently in a transient thread state.
1927 if (is_ext_suspend_completed(false /* !called_by_wait */,
1928 SuspendRetryDelay, &debug_bits) ) {
1929 return;
1930 }
1931 }
1932
1933 VM_ForceSafepoint vm_suspend;
1934 VMThread::execute(&vm_suspend);
1935 }
1936
1937 // Part II of external suspension.
1938 // A JavaThread self suspends when it detects a pending external suspend
1939 // request. This is usually on transitions. It is also done in places
1940 // where continuing to the next transition would surprise the caller,
1941 // e.g., monitor entry.
1942 //
1943 // Returns the number of times that the thread self-suspended.
1944 //
1945 // Note: DO NOT call java_suspend_self() when you just want to block current
1946 // thread. java_suspend_self() is the second stage of cooperative
1947 // suspension for external suspend requests and should only be used
1948 // to complete an external suspend request.
1949 //
1950 int JavaThread::java_suspend_self() {
1951 int ret = 0;
1952
1953 // we are in the process of exiting so don't suspend
1954 if (is_exiting()) {
1955 clear_external_suspend();
1956 return ret;
1957 }
1958
1959 assert(_anchor.walkable() ||
1960 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
1961 "must have walkable stack");
1962
1963 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1964
1965 assert(!this->is_ext_suspended(),
1966 "a thread trying to self-suspend should not already be suspended");
1967
1968 if (this->is_suspend_equivalent()) {
1969 // If we are self-suspending as a result of the lifting of a
1970 // suspend equivalent condition, then the suspend_equivalent
1971 // flag is not cleared until we set the ext_suspended flag so
1972 // that wait_for_ext_suspend_completion() returns consistent
1973 // results.
1974 this->clear_suspend_equivalent();
1975 }
1976
1977 // A racing resume may have cancelled us before we grabbed SR_lock
1978 // above. Or another external suspend request could be waiting for us
1979 // by the time we return from SR_lock()->wait(). The thread
1980 // that requested the suspension may already be trying to walk our
1981 // stack and if we return now, we can change the stack out from under
1982 // it. This would be a "bad thing (TM)" and cause the stack walker
1983 // to crash. We stay self-suspended until there are no more pending
1984 // external suspend requests.
1985 while (is_external_suspend()) {
1986 ret++;
1987 this->set_ext_suspended();
1988
1989 // _ext_suspended flag is cleared by java_resume()
1990 while (is_ext_suspended()) {
1991 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
1992 }
1993 }
1994
1995 return ret;
1996 }
1997
1998 #ifdef ASSERT
1999 // verify the JavaThread has not yet been published in the Threads::list, and
2000 // hence doesn't need protection from concurrent access at this stage
2001 void JavaThread::verify_not_published() {
2002 if (!Threads_lock->owned_by_self()) {
2003 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2004 assert( !Threads::includes(this),
2005 "java thread shouldn't have been published yet!");
2006 }
2007 else {
2008 assert( !Threads::includes(this),
2009 "java thread shouldn't have been published yet!");
2010 }
2011 }
2012 #endif
2013
2014 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2015 // progress or when _suspend_flags is non-zero.
2016 // Current thread needs to self-suspend if there is a suspend request and/or
2017 // block if a safepoint is in progress.
2018 // Async exception ISN'T checked.
2019 // Note only the ThreadInVMfromNative transition can call this function
2020 // directly and when thread state is _thread_in_native_trans
2021 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2022 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2023
2024 JavaThread *curJT = JavaThread::current();
2025 bool do_self_suspend = thread->is_external_suspend();
2026
2027 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2028
2029 // If JNIEnv proxies are allowed, don't self-suspend if the target
2030 // thread is not the current thread. In older versions of jdbx, jdbx
2031 // threads could call into the VM with another thread's JNIEnv so we
2032 // can be here operating on behalf of a suspended thread (4432884).
2033 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2034 JavaThreadState state = thread->thread_state();
2035
2036 // We mark this thread_blocked state as a suspend-equivalent so
2037 // that a caller to is_ext_suspend_completed() won't be confused.
2038 // The suspend-equivalent state is cleared by java_suspend_self().
2039 thread->set_suspend_equivalent();
2040
2041 // If the safepoint code sees the _thread_in_native_trans state, it will
2042 // wait until the thread changes to other thread state. There is no
2043 // guarantee on how soon we can obtain the SR_lock and complete the
2044 // self-suspend request. It would be a bad idea to let safepoint wait for
2045 // too long. Temporarily change the state to _thread_blocked to
2046 // let the VM thread know that this thread is ready for GC. The problem
2047 // of changing thread state is that safepoint could happen just after
2048 // java_suspend_self() returns after being resumed, and VM thread will
2049 // see the _thread_blocked state. We must check for safepoint
2050 // after restoring the state and make sure we won't leave while a safepoint
2051 // is in progress.
2052 thread->set_thread_state(_thread_blocked);
2053 thread->java_suspend_self();
2054 thread->set_thread_state(state);
2055 // Make sure new state is seen by VM thread
2056 if (os::is_MP()) {
2057 if (UseMembar) {
2058 // Force a fence between the write above and read below
2059 OrderAccess::fence();
2060 } else {
2061 // Must use this rather than serialization page in particular on Windows
2062 InterfaceSupport::serialize_memory(thread);
2063 }
2064 }
2065 }
2066
2067 if (SafepointSynchronize::do_call_back()) {
2068 // If we are safepointing, then block the caller which may not be
2069 // the same as the target thread (see above).
2070 SafepointSynchronize::block(curJT);
2071 }
2072
2073 if (thread->is_deopt_suspend()) {
2074 thread->clear_deopt_suspend();
2075 RegisterMap map(thread, false);
2076 frame f = thread->last_frame();
2077 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2078 f = f.sender(&map);
2079 }
2080 if (f.id() == thread->must_deopt_id()) {
2081 thread->clear_must_deopt_id();
2082 // Since we know we're safe to deopt the current state is a safe state
2083 f.deoptimize(thread, true);
2084 } else {
2085 fatal("missed deoptimization!");
2086 }
2087 }
2088 }
2089
2090 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2091 // progress or when _suspend_flags is non-zero.
2092 // Current thread needs to self-suspend if there is a suspend request and/or
2093 // block if a safepoint is in progress.
2094 // Also check for pending async exception (not including unsafe access error).
2095 // Note only the native==>VM/Java barriers can call this function and when
2096 // thread state is _thread_in_native_trans.
2097 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2098 check_safepoint_and_suspend_for_native_trans(thread);
2099
2100 if (thread->has_async_exception()) {
2101 // We are in _thread_in_native_trans state, don't handle unsafe
2102 // access error since that may block.
2103 thread->check_and_handle_async_exceptions(false);
2104 }
2105 }
2106
2107 // We need to guarantee the Threads_lock here, since resumes are not
2108 // allowed during safepoint synchronization
2109 // Can only resume from an external suspension
2110 void JavaThread::java_resume() {
2111 assert_locked_or_safepoint(Threads_lock);
2112
2113 // Sanity check: thread is gone, has started exiting or the thread
2114 // was not externally suspended.
2115 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2116 return;
2117 }
2118
2119 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2120
2121 clear_external_suspend();
2122
2123 if (is_ext_suspended()) {
2124 clear_ext_suspended();
2125 SR_lock()->notify_all();
2126 }
2127 }
2128
2129 void JavaThread::create_stack_guard_pages() {
2130 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2131 address low_addr = stack_base() - stack_size();
2132 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2133
2134 int allocate = os::allocate_stack_guard_pages();
2135 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2136
2137 if (allocate && !os::commit_memory((char *) low_addr, len)) {
2138 warning("Attempt to allocate stack guard pages failed.");
2139 return;
2140 }
2141
2142 if (os::guard_memory((char *) low_addr, len)) {
2143 _stack_guard_state = stack_guard_enabled;
2144 } else {
2145 warning("Attempt to protect stack guard pages failed.");
2146 if (os::uncommit_memory((char *) low_addr, len)) {
2147 warning("Attempt to deallocate stack guard pages failed.");
2148 }
2149 }
2150 }
2151
2152 void JavaThread::remove_stack_guard_pages() {
2153 if (_stack_guard_state == stack_guard_unused) return;
2154 address low_addr = stack_base() - stack_size();
2155 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2156
2157 if (os::allocate_stack_guard_pages()) {
2158 if (os::uncommit_memory((char *) low_addr, len)) {
2159 _stack_guard_state = stack_guard_unused;
2160 } else {
2161 warning("Attempt to deallocate stack guard pages failed.");
2162 }
2163 } else {
2164 if (_stack_guard_state == stack_guard_unused) return;
2165 if (os::unguard_memory((char *) low_addr, len)) {
2166 _stack_guard_state = stack_guard_unused;
2167 } else {
2168 warning("Attempt to unprotect stack guard pages failed.");
2169 }
2170 }
2171 }
2172
2173 void JavaThread::enable_stack_yellow_zone() {
2174 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2175 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2176
2177 // The base notation is from the stacks point of view, growing downward.
2178 // We need to adjust it to work correctly with guard_memory()
2179 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2180
2181 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2182 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2183
2184 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2185 _stack_guard_state = stack_guard_enabled;
2186 } else {
2187 warning("Attempt to guard stack yellow zone failed.");
2188 }
2189 enable_register_stack_guard();
2190 }
2191
2192 void JavaThread::disable_stack_yellow_zone() {
2193 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2194 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2195
2196 // Simply return if called for a thread that does not use guard pages.
2197 if (_stack_guard_state == stack_guard_unused) return;
2198
2199 // The base notation is from the stacks point of view, growing downward.
2200 // We need to adjust it to work correctly with guard_memory()
2201 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2202
2203 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2204 _stack_guard_state = stack_guard_yellow_disabled;
2205 } else {
2206 warning("Attempt to unguard stack yellow zone failed.");
2207 }
2208 disable_register_stack_guard();
2209 }
2210
2211 void JavaThread::enable_stack_red_zone() {
2212 // The base notation is from the stacks point of view, growing downward.
2213 // We need to adjust it to work correctly with guard_memory()
2214 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2215 address base = stack_red_zone_base() - stack_red_zone_size();
2216
2217 guarantee(base < stack_base(),"Error calculating stack red zone");
2218 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2219
2220 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2221 warning("Attempt to guard stack red zone failed.");
2222 }
2223 }
2224
2225 void JavaThread::disable_stack_red_zone() {
2226 // The base notation is from the stacks point of view, growing downward.
2227 // We need to adjust it to work correctly with guard_memory()
2228 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2229 address base = stack_red_zone_base() - stack_red_zone_size();
2230 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2231 warning("Attempt to unguard stack red zone failed.");
2232 }
2233 }
2234
2235 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2236 // ignore is there is no stack
2237 if (!has_last_Java_frame()) return;
2238 // traverse the stack frames. Starts from top frame.
2239 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2240 frame* fr = fst.current();
2241 f(fr, fst.register_map());
2242 }
2243 }
2244
2245
2246 #ifndef PRODUCT
2247 // Deoptimization
2248 // Function for testing deoptimization
2249 void JavaThread::deoptimize() {
2250 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2251 StackFrameStream fst(this, UseBiasedLocking);
2252 bool deopt = false; // Dump stack only if a deopt actually happens.
2253 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2254 // Iterate over all frames in the thread and deoptimize
2255 for(; !fst.is_done(); fst.next()) {
2256 if(fst.current()->can_be_deoptimized()) {
2257
2258 if (only_at) {
2259 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2260 // consists of comma or carriage return separated numbers so
2261 // search for the current bci in that string.
2262 address pc = fst.current()->pc();
2263 nmethod* nm = (nmethod*) fst.current()->cb();
2264 ScopeDesc* sd = nm->scope_desc_at( pc);
2265 char buffer[8];
2266 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2267 size_t len = strlen(buffer);
2268 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2269 while (found != NULL) {
2270 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2271 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2272 // Check that the bci found is bracketed by terminators.
2273 break;
2274 }
2275 found = strstr(found + 1, buffer);
2276 }
2277 if (!found) {
2278 continue;
2279 }
2280 }
2281
2282 if (DebugDeoptimization && !deopt) {
2283 deopt = true; // One-time only print before deopt
2284 tty->print_cr("[BEFORE Deoptimization]");
2285 trace_frames();
2286 trace_stack();
2287 }
2288 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2289 }
2290 }
2291
2292 if (DebugDeoptimization && deopt) {
2293 tty->print_cr("[AFTER Deoptimization]");
2294 trace_frames();
2295 }
2296 }
2297
2298
2299 // Make zombies
2300 void JavaThread::make_zombies() {
2301 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2302 if (fst.current()->can_be_deoptimized()) {
2303 // it is a Java nmethod
2304 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2305 nm->make_not_entrant();
2306 }
2307 }
2308 }
2309 #endif // PRODUCT
2310
2311
2312 void JavaThread::deoptimized_wrt_marked_nmethods() {
2313 if (!has_last_Java_frame()) return;
2314 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2315 StackFrameStream fst(this, UseBiasedLocking);
2316 for(; !fst.is_done(); fst.next()) {
2317 if (fst.current()->should_be_deoptimized()) {
2318 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2319 }
2320 }
2321 }
2322
2323
2324 // GC support
2325 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2326
2327 void JavaThread::gc_epilogue() {
2328 frames_do(frame_gc_epilogue);
2329 }
2330
2331
2332 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2333
2334 void JavaThread::gc_prologue() {
2335 frames_do(frame_gc_prologue);
2336 }
2337
2338 // If the caller is a NamedThread, then remember, in the current scope,
2339 // the given JavaThread in its _processed_thread field.
2340 class RememberProcessedThread: public StackObj {
2341 NamedThread* _cur_thr;
2342 public:
2343 RememberProcessedThread(JavaThread* jthr) {
2344 Thread* thread = Thread::current();
2345 if (thread->is_Named_thread()) {
2346 _cur_thr = (NamedThread *)thread;
2347 _cur_thr->set_processed_thread(jthr);
2348 } else {
2349 _cur_thr = NULL;
2350 }
2351 }
2352
2353 ~RememberProcessedThread() {
2354 if (_cur_thr) {
2355 _cur_thr->set_processed_thread(NULL);
2356 }
2357 }
2358 };
2359
2360 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2361 // Flush deferred store-barriers, if any, associated with
2362 // initializing stores done by this JavaThread in the current epoch.
2363 Universe::heap()->flush_deferred_store_barrier(this);
2364
2365 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2366 // since there may be more than one thread using each ThreadProfiler.
2367
2368 // Traverse the GCHandles
2369 Thread::oops_do(f, cf);
2370
2371 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2372 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2373
2374 if (has_last_Java_frame()) {
2375 // Record JavaThread to GC thread
2376 RememberProcessedThread rpt(this);
2377
2378 // Traverse the privileged stack
2379 if (_privileged_stack_top != NULL) {
2380 _privileged_stack_top->oops_do(f);
2381 }
2382
2383 // traverse the registered growable array
2384 if (_array_for_gc != NULL) {
2385 for (int index = 0; index < _array_for_gc->length(); index++) {
2386 f->do_oop(_array_for_gc->adr_at(index));
2387 }
2388 }
2389
2390 // Traverse the monitor chunks
2391 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2392 chunk->oops_do(f);
2393 }
2394
2395 // Traverse the execution stack
2396 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2397 fst.current()->oops_do(f, cf, fst.register_map());
2398 }
2399 }
2400
2401 // callee_target is never live across a gc point so NULL it here should
2402 // it still contain a methdOop.
2403
2404 set_callee_target(NULL);
2405
2406 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2407 // If we have deferred set_locals there might be oops waiting to be
2408 // written
2409 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2410 if (list != NULL) {
2411 for (int i = 0; i < list->length(); i++) {
2412 list->at(i)->oops_do(f);
2413 }
2414 }
2415
2416 // Traverse instance variables at the end since the GC may be moving things
2417 // around using this function
2418 f->do_oop((oop*) &_threadObj);
2419 f->do_oop((oop*) &_vm_result);
2420 f->do_oop((oop*) &_vm_result_2);
2421 f->do_oop((oop*) &_exception_oop);
2422 f->do_oop((oop*) &_pending_async_exception);
2423
2424 if (jvmti_thread_state() != NULL) {
2425 jvmti_thread_state()->oops_do(f);
2426 }
2427 }
2428
2429 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2430 Thread::nmethods_do(cf); // (super method is a no-op)
2431
2432 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2433 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2434
2435 if (has_last_Java_frame()) {
2436 // Traverse the execution stack
2437 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2438 fst.current()->nmethods_do(cf);
2439 }
2440 }
2441 }
2442
2443 // Printing
2444 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2445 switch (_thread_state) {
2446 case _thread_uninitialized: return "_thread_uninitialized";
2447 case _thread_new: return "_thread_new";
2448 case _thread_new_trans: return "_thread_new_trans";
2449 case _thread_in_native: return "_thread_in_native";
2450 case _thread_in_native_trans: return "_thread_in_native_trans";
2451 case _thread_in_vm: return "_thread_in_vm";
2452 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2453 case _thread_in_Java: return "_thread_in_Java";
2454 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2455 case _thread_blocked: return "_thread_blocked";
2456 case _thread_blocked_trans: return "_thread_blocked_trans";
2457 default: return "unknown thread state";
2458 }
2459 }
2460
2461 #ifndef PRODUCT
2462 void JavaThread::print_thread_state_on(outputStream *st) const {
2463 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2464 };
2465 void JavaThread::print_thread_state() const {
2466 print_thread_state_on(tty);
2467 };
2468 #endif // PRODUCT
2469
2470 // Called by Threads::print() for VM_PrintThreads operation
2471 void JavaThread::print_on(outputStream *st) const {
2472 st->print("\"%s\" ", get_thread_name());
2473 oop thread_oop = threadObj();
2474 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2475 Thread::print_on(st);
2476 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2477 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2478 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2479 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2480 }
2481 #ifndef PRODUCT
2482 print_thread_state_on(st);
2483 _safepoint_state->print_on(st);
2484 #endif // PRODUCT
2485 }
2486
2487 // Called by fatal error handler. The difference between this and
2488 // JavaThread::print() is that we can't grab lock or allocate memory.
2489 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2490 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2491 oop thread_obj = threadObj();
2492 if (thread_obj != NULL) {
2493 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2494 }
2495 st->print(" [");
2496 st->print("%s", _get_thread_state_name(_thread_state));
2497 if (osthread()) {
2498 st->print(", id=%d", osthread()->thread_id());
2499 }
2500 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2501 _stack_base - _stack_size, _stack_base);
2502 st->print("]");
2503 return;
2504 }
2505
2506 // Verification
2507
2508 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2509
2510 void JavaThread::verify() {
2511 // Verify oops in the thread.
2512 oops_do(&VerifyOopClosure::verify_oop, NULL);
2513
2514 // Verify the stack frames.
2515 frames_do(frame_verify);
2516 }
2517
2518 // CR 6300358 (sub-CR 2137150)
2519 // Most callers of this method assume that it can't return NULL but a
2520 // thread may not have a name whilst it is in the process of attaching to
2521 // the VM - see CR 6412693, and there are places where a JavaThread can be
2522 // seen prior to having it's threadObj set (eg JNI attaching threads and
2523 // if vm exit occurs during initialization). These cases can all be accounted
2524 // for such that this method never returns NULL.
2525 const char* JavaThread::get_thread_name() const {
2526 #ifdef ASSERT
2527 // early safepoints can hit while current thread does not yet have TLS
2528 if (!SafepointSynchronize::is_at_safepoint()) {
2529 Thread *cur = Thread::current();
2530 if (!(cur->is_Java_thread() && cur == this)) {
2531 // Current JavaThreads are allowed to get their own name without
2532 // the Threads_lock.
2533 assert_locked_or_safepoint(Threads_lock);
2534 }
2535 }
2536 #endif // ASSERT
2537 return get_thread_name_string();
2538 }
2539
2540 // Returns a non-NULL representation of this thread's name, or a suitable
2541 // descriptive string if there is no set name
2542 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2543 const char* name_str;
2544 oop thread_obj = threadObj();
2545 if (thread_obj != NULL) {
2546 typeArrayOop name = java_lang_Thread::name(thread_obj);
2547 if (name != NULL) {
2548 if (buf == NULL) {
2549 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2550 }
2551 else {
2552 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2553 }
2554 }
2555 else if (is_attaching()) { // workaround for 6412693 - see 6404306
2556 name_str = "<no-name - thread is attaching>";
2557 }
2558 else {
2559 name_str = Thread::name();
2560 }
2561 }
2562 else {
2563 name_str = Thread::name();
2564 }
2565 assert(name_str != NULL, "unexpected NULL thread name");
2566 return name_str;
2567 }
2568
2569
2570 const char* JavaThread::get_threadgroup_name() const {
2571 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2572 oop thread_obj = threadObj();
2573 if (thread_obj != NULL) {
2574 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2575 if (thread_group != NULL) {
2576 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2577 // ThreadGroup.name can be null
2578 if (name != NULL) {
2579 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2580 return str;
2581 }
2582 }
2583 }
2584 return NULL;
2585 }
2586
2587 const char* JavaThread::get_parent_name() const {
2588 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2589 oop thread_obj = threadObj();
2590 if (thread_obj != NULL) {
2591 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2592 if (thread_group != NULL) {
2593 oop parent = java_lang_ThreadGroup::parent(thread_group);
2594 if (parent != NULL) {
2595 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2596 // ThreadGroup.name can be null
2597 if (name != NULL) {
2598 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2599 return str;
2600 }
2601 }
2602 }
2603 }
2604 return NULL;
2605 }
2606
2607 ThreadPriority JavaThread::java_priority() const {
2608 oop thr_oop = threadObj();
2609 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2610 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2611 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2612 return priority;
2613 }
2614
2615 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2616
2617 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2618 // Link Java Thread object <-> C++ Thread
2619
2620 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2621 // and put it into a new Handle. The Handle "thread_oop" can then
2622 // be used to pass the C++ thread object to other methods.
2623
2624 // Set the Java level thread object (jthread) field of the
2625 // new thread (a JavaThread *) to C++ thread object using the
2626 // "thread_oop" handle.
2627
2628 // Set the thread field (a JavaThread *) of the
2629 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2630
2631 Handle thread_oop(Thread::current(),
2632 JNIHandles::resolve_non_null(jni_thread));
2633 assert(instanceKlass::cast(thread_oop->klass())->is_linked(),
2634 "must be initialized");
2635 set_threadObj(thread_oop());
2636 java_lang_Thread::set_thread(thread_oop(), this);
2637
2638 if (prio == NoPriority) {
2639 prio = java_lang_Thread::priority(thread_oop());
2640 assert(prio != NoPriority, "A valid priority should be present");
2641 }
2642
2643 // Push the Java priority down to the native thread; needs Threads_lock
2644 Thread::set_priority(this, prio);
2645
2646 // Add the new thread to the Threads list and set it in motion.
2647 // We must have threads lock in order to call Threads::add.
2648 // It is crucial that we do not block before the thread is
2649 // added to the Threads list for if a GC happens, then the java_thread oop
2650 // will not be visited by GC.
2651 Threads::add(this);
2652 }
2653
2654 oop JavaThread::current_park_blocker() {
2655 // Support for JSR-166 locks
2656 oop thread_oop = threadObj();
2657 if (thread_oop != NULL &&
2658 JDK_Version::current().supports_thread_park_blocker()) {
2659 return java_lang_Thread::park_blocker(thread_oop);
2660 }
2661 return NULL;
2662 }
2663
2664
2665 void JavaThread::print_stack_on(outputStream* st) {
2666 if (!has_last_Java_frame()) return;
2667 ResourceMark rm;
2668 HandleMark hm;
2669
2670 RegisterMap reg_map(this);
2671 vframe* start_vf = last_java_vframe(®_map);
2672 int count = 0;
2673 for (vframe* f = start_vf; f; f = f->sender() ) {
2674 if (f->is_java_frame()) {
2675 javaVFrame* jvf = javaVFrame::cast(f);
2676 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2677
2678 // Print out lock information
2679 if (JavaMonitorsInStackTrace) {
2680 jvf->print_lock_info_on(st, count);
2681 }
2682 } else {
2683 // Ignore non-Java frames
2684 }
2685
2686 // Bail-out case for too deep stacks
2687 count++;
2688 if (MaxJavaStackTraceDepth == count) return;
2689 }
2690 }
2691
2692
2693 // JVMTI PopFrame support
2694 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2695 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2696 if (in_bytes(size_in_bytes) != 0) {
2697 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes));
2698 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2699 Copy::conjoint_bytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2700 }
2701 }
2702
2703 void* JavaThread::popframe_preserved_args() {
2704 return _popframe_preserved_args;
2705 }
2706
2707 ByteSize JavaThread::popframe_preserved_args_size() {
2708 return in_ByteSize(_popframe_preserved_args_size);
2709 }
2710
2711 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2712 int sz = in_bytes(popframe_preserved_args_size());
2713 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2714 return in_WordSize(sz / wordSize);
2715 }
2716
2717 void JavaThread::popframe_free_preserved_args() {
2718 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2719 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args);
2720 _popframe_preserved_args = NULL;
2721 _popframe_preserved_args_size = 0;
2722 }
2723
2724 #ifndef PRODUCT
2725
2726 void JavaThread::trace_frames() {
2727 tty->print_cr("[Describe stack]");
2728 int frame_no = 1;
2729 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2730 tty->print(" %d. ", frame_no++);
2731 fst.current()->print_value_on(tty,this);
2732 tty->cr();
2733 }
2734 }
2735
2736
2737 void JavaThread::trace_stack_from(vframe* start_vf) {
2738 ResourceMark rm;
2739 int vframe_no = 1;
2740 for (vframe* f = start_vf; f; f = f->sender() ) {
2741 if (f->is_java_frame()) {
2742 javaVFrame::cast(f)->print_activation(vframe_no++);
2743 } else {
2744 f->print();
2745 }
2746 if (vframe_no > StackPrintLimit) {
2747 tty->print_cr("...<more frames>...");
2748 return;
2749 }
2750 }
2751 }
2752
2753
2754 void JavaThread::trace_stack() {
2755 if (!has_last_Java_frame()) return;
2756 ResourceMark rm;
2757 HandleMark hm;
2758 RegisterMap reg_map(this);
2759 trace_stack_from(last_java_vframe(®_map));
2760 }
2761
2762
2763 #endif // PRODUCT
2764
2765
2766 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2767 assert(reg_map != NULL, "a map must be given");
2768 frame f = last_frame();
2769 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
2770 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2771 }
2772 return NULL;
2773 }
2774
2775
2776 klassOop JavaThread::security_get_caller_class(int depth) {
2777 vframeStream vfst(this);
2778 vfst.security_get_caller_frame(depth);
2779 if (!vfst.at_end()) {
2780 return vfst.method()->method_holder();
2781 }
2782 return NULL;
2783 }
2784
2785 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
2786 assert(thread->is_Compiler_thread(), "must be compiler thread");
2787 CompileBroker::compiler_thread_loop();
2788 }
2789
2790 // Create a CompilerThread
2791 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
2792 : JavaThread(&compiler_thread_entry) {
2793 _env = NULL;
2794 _log = NULL;
2795 _task = NULL;
2796 _queue = queue;
2797 _counters = counters;
2798
2799 #ifndef PRODUCT
2800 _ideal_graph_printer = NULL;
2801 #endif
2802 }
2803
2804
2805 // ======= Threads ========
2806
2807 // The Threads class links together all active threads, and provides
2808 // operations over all threads. It is protected by its own Mutex
2809 // lock, which is also used in other contexts to protect thread
2810 // operations from having the thread being operated on from exiting
2811 // and going away unexpectedly (e.g., safepoint synchronization)
2812
2813 JavaThread* Threads::_thread_list = NULL;
2814 int Threads::_number_of_threads = 0;
2815 int Threads::_number_of_non_daemon_threads = 0;
2816 int Threads::_return_code = 0;
2817 size_t JavaThread::_stack_size_at_create = 0;
2818
2819 // All JavaThreads
2820 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
2821
2822 void os_stream();
2823
2824 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
2825 void Threads::threads_do(ThreadClosure* tc) {
2826 assert_locked_or_safepoint(Threads_lock);
2827 // ALL_JAVA_THREADS iterates through all JavaThreads
2828 ALL_JAVA_THREADS(p) {
2829 tc->do_thread(p);
2830 }
2831 // Someday we could have a table or list of all non-JavaThreads.
2832 // For now, just manually iterate through them.
2833 tc->do_thread(VMThread::vm_thread());
2834 Universe::heap()->gc_threads_do(tc);
2835 WatcherThread *wt = WatcherThread::watcher_thread();
2836 // Strictly speaking, the following NULL check isn't sufficient to make sure
2837 // the data for WatcherThread is still valid upon being examined. However,
2838 // considering that WatchThread terminates when the VM is on the way to
2839 // exit at safepoint, the chance of the above is extremely small. The right
2840 // way to prevent termination of WatcherThread would be to acquire
2841 // Terminator_lock, but we can't do that without violating the lock rank
2842 // checking in some cases.
2843 if (wt != NULL)
2844 tc->do_thread(wt);
2845
2846 // If CompilerThreads ever become non-JavaThreads, add them here
2847 }
2848
2849 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2850
2851 extern void JDK_Version_init();
2852
2853 // Check version
2854 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2855
2856 // Initialize the output stream module
2857 ostream_init();
2858
2859 // Process java launcher properties.
2860 Arguments::process_sun_java_launcher_properties(args);
2861
2862 // Initialize the os module before using TLS
2863 os::init();
2864
2865 // Initialize system properties.
2866 Arguments::init_system_properties();
2867
2868 // So that JDK version can be used as a discrimintor when parsing arguments
2869 JDK_Version_init();
2870
2871 // Parse arguments
2872 jint parse_result = Arguments::parse(args);
2873 if (parse_result != JNI_OK) return parse_result;
2874
2875 if (PauseAtStartup) {
2876 os::pause();
2877 }
2878
2879 HS_DTRACE_PROBE(hotspot, vm__init__begin);
2880
2881 // Record VM creation timing statistics
2882 TraceVmCreationTime create_vm_timer;
2883 create_vm_timer.start();
2884
2885 // Timing (must come after argument parsing)
2886 TraceTime timer("Create VM", TraceStartupTime);
2887
2888 // Initialize the os module after parsing the args
2889 jint os_init_2_result = os::init_2();
2890 if (os_init_2_result != JNI_OK) return os_init_2_result;
2891
2892 // Initialize output stream logging
2893 ostream_init_log();
2894
2895 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2896 // Must be before create_vm_init_agents()
2897 if (Arguments::init_libraries_at_startup()) {
2898 convert_vm_init_libraries_to_agents();
2899 }
2900
2901 // Launch -agentlib/-agentpath and converted -Xrun agents
2902 if (Arguments::init_agents_at_startup()) {
2903 create_vm_init_agents();
2904 }
2905
2906 // Initialize Threads state
2907 _thread_list = NULL;
2908 _number_of_threads = 0;
2909 _number_of_non_daemon_threads = 0;
2910
2911 // Initialize TLS
2912 ThreadLocalStorage::init();
2913
2914 // Initialize global data structures and create system classes in heap
2915 vm_init_globals();
2916
2917 // Attach the main thread to this os thread
2918 JavaThread* main_thread = new JavaThread();
2919 main_thread->set_thread_state(_thread_in_vm);
2920 // must do this before set_active_handles and initialize_thread_local_storage
2921 // Note: on solaris initialize_thread_local_storage() will (indirectly)
2922 // change the stack size recorded here to one based on the java thread
2923 // stacksize. This adjusted size is what is used to figure the placement
2924 // of the guard pages.
2925 main_thread->record_stack_base_and_size();
2926 main_thread->initialize_thread_local_storage();
2927
2928 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2929
2930 if (!main_thread->set_as_starting_thread()) {
2931 vm_shutdown_during_initialization(
2932 "Failed necessary internal allocation. Out of swap space");
2933 delete main_thread;
2934 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2935 return JNI_ENOMEM;
2936 }
2937
2938 // Enable guard page *after* os::create_main_thread(), otherwise it would
2939 // crash Linux VM, see notes in os_linux.cpp.
2940 main_thread->create_stack_guard_pages();
2941
2942 // Initialize Java-Leve synchronization subsystem
2943 ObjectSynchronizer::Initialize() ;
2944
2945 // Initialize global modules
2946 jint status = init_globals();
2947 if (status != JNI_OK) {
2948 delete main_thread;
2949 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2950 return status;
2951 }
2952
2953 HandleMark hm;
2954
2955 { MutexLocker mu(Threads_lock);
2956 Threads::add(main_thread);
2957 }
2958
2959 // Any JVMTI raw monitors entered in onload will transition into
2960 // real raw monitor. VM is setup enough here for raw monitor enter.
2961 JvmtiExport::transition_pending_onload_raw_monitors();
2962
2963 if (VerifyBeforeGC &&
2964 Universe::heap()->total_collections() >= VerifyGCStartAt) {
2965 Universe::heap()->prepare_for_verify();
2966 Universe::verify(); // make sure we're starting with a clean slate
2967 }
2968
2969 // Create the VMThread
2970 { TraceTime timer("Start VMThread", TraceStartupTime);
2971 VMThread::create();
2972 Thread* vmthread = VMThread::vm_thread();
2973
2974 if (!os::create_thread(vmthread, os::vm_thread))
2975 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
2976
2977 // Wait for the VM thread to become ready, and VMThread::run to initialize
2978 // Monitors can have spurious returns, must always check another state flag
2979 {
2980 MutexLocker ml(Notify_lock);
2981 os::start_thread(vmthread);
2982 while (vmthread->active_handles() == NULL) {
2983 Notify_lock->wait();
2984 }
2985 }
2986 }
2987
2988 assert (Universe::is_fully_initialized(), "not initialized");
2989 EXCEPTION_MARK;
2990
2991 // At this point, the Universe is initialized, but we have not executed
2992 // any byte code. Now is a good time (the only time) to dump out the
2993 // internal state of the JVM for sharing.
2994
2995 if (DumpSharedSpaces) {
2996 Universe::heap()->preload_and_dump(CHECK_0);
2997 ShouldNotReachHere();
2998 }
2999
3000 // Always call even when there are not JVMTI environments yet, since environments
3001 // may be attached late and JVMTI must track phases of VM execution
3002 JvmtiExport::enter_start_phase();
3003
3004 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3005 JvmtiExport::post_vm_start();
3006
3007 {
3008 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3009
3010 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3011 create_vm_init_libraries();
3012 }
3013
3014 if (InitializeJavaLangString) {
3015 initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0);
3016 } else {
3017 warning("java.lang.String not initialized");
3018 }
3019
3020 if (AggressiveOpts) {
3021 {
3022 // Forcibly initialize java/util/HashMap and mutate the private
3023 // static final "frontCacheEnabled" field before we start creating instances
3024 #ifdef ASSERT
3025 klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3026 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
3027 #endif
3028 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3029 KlassHandle k = KlassHandle(THREAD, k_o);
3030 guarantee(k.not_null(), "Must find java/util/HashMap");
3031 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3032 ik->initialize(CHECK_0);
3033 fieldDescriptor fd;
3034 // Possible we might not find this field; if so, don't break
3035 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3036 k()->bool_field_put(fd.offset(), true);
3037 }
3038 }
3039
3040 if (UseStringCache) {
3041 // Forcibly initialize java/lang/StringValue and mutate the private
3042 // static final "stringCacheEnabled" field before we start creating instances
3043 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3044 // Possible that StringValue isn't present: if so, silently don't break
3045 if (k_o != NULL) {
3046 KlassHandle k = KlassHandle(THREAD, k_o);
3047 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3048 ik->initialize(CHECK_0);
3049 fieldDescriptor fd;
3050 // Possible we might not find this field: if so, silently don't break
3051 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3052 k()->bool_field_put(fd.offset(), true);
3053 }
3054 }
3055 }
3056 }
3057
3058 // Initialize java_lang.System (needed before creating the thread)
3059 if (InitializeJavaLangSystem) {
3060 initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0);
3061 initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0);
3062 Handle thread_group = create_initial_thread_group(CHECK_0);
3063 Universe::set_main_thread_group(thread_group());
3064 initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0);
3065 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3066 main_thread->set_threadObj(thread_object);
3067 // Set thread status to running since main thread has
3068 // been started and running.
3069 java_lang_Thread::set_thread_status(thread_object,
3070 java_lang_Thread::RUNNABLE);
3071
3072 // The VM preresolve methods to these classes. Make sure that get initialized
3073 initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0);
3074 initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0);
3075 // The VM creates & returns objects of this class. Make sure it's initialized.
3076 initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0);
3077 call_initializeSystemClass(CHECK_0);
3078 } else {
3079 warning("java.lang.System not initialized");
3080 }
3081
3082 // an instance of OutOfMemory exception has been allocated earlier
3083 if (InitializeJavaLangExceptionsErrors) {
3084 initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0);
3085 initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0);
3086 initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0);
3087 initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0);
3088 initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0);
3089 initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0);
3090 initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0);
3091 } else {
3092 warning("java.lang.OutOfMemoryError has not been initialized");
3093 warning("java.lang.NullPointerException has not been initialized");
3094 warning("java.lang.ClassCastException has not been initialized");
3095 warning("java.lang.ArrayStoreException has not been initialized");
3096 warning("java.lang.ArithmeticException has not been initialized");
3097 warning("java.lang.StackOverflowError has not been initialized");
3098 }
3099
3100 if (EnableInvokeDynamic) {
3101 // JSR 292: An intialized java.dyn.InvokeDynamic is required in
3102 // the compiler.
3103 initialize_class(vmSymbolHandles::java_dyn_InvokeDynamic(), CHECK_0);
3104 }
3105 }
3106
3107 // See : bugid 4211085.
3108 // Background : the static initializer of java.lang.Compiler tries to read
3109 // property"java.compiler" and read & write property "java.vm.info".
3110 // When a security manager is installed through the command line
3111 // option "-Djava.security.manager", the above properties are not
3112 // readable and the static initializer for java.lang.Compiler fails
3113 // resulting in a NoClassDefFoundError. This can happen in any
3114 // user code which calls methods in java.lang.Compiler.
3115 // Hack : the hack is to pre-load and initialize this class, so that only
3116 // system domains are on the stack when the properties are read.
3117 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3118 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3119 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3120 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3121 // Once that is done, we should remove this hack.
3122 initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0);
3123
3124 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3125 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3126 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3127 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3128 // This should also be taken out as soon as 4211383 gets fixed.
3129 reset_vm_info_property(CHECK_0);
3130
3131 quicken_jni_functions();
3132
3133 // Set flag that basic initialization has completed. Used by exceptions and various
3134 // debug stuff, that does not work until all basic classes have been initialized.
3135 set_init_completed();
3136
3137 HS_DTRACE_PROBE(hotspot, vm__init__end);
3138
3139 // record VM initialization completion time
3140 Management::record_vm_init_completed();
3141
3142 // Compute system loader. Note that this has to occur after set_init_completed, since
3143 // valid exceptions may be thrown in the process.
3144 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3145 // set_init_completed has just been called, causing exceptions not to be shortcut
3146 // anymore. We call vm_exit_during_initialization directly instead.
3147 SystemDictionary::compute_java_system_loader(THREAD);
3148 if (HAS_PENDING_EXCEPTION) {
3149 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3150 }
3151
3152 #ifdef KERNEL
3153 if (JDK_Version::is_gte_jdk17x_version()) {
3154 set_jkernel_boot_classloader_hook(THREAD);
3155 }
3156 #endif // KERNEL
3157
3158 #ifndef SERIALGC
3159 // Support for ConcurrentMarkSweep. This should be cleaned up
3160 // and better encapsulated. The ugly nested if test would go away
3161 // once things are properly refactored. XXX YSR
3162 if (UseConcMarkSweepGC || UseG1GC) {
3163 if (UseConcMarkSweepGC) {
3164 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3165 } else {
3166 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3167 }
3168 if (HAS_PENDING_EXCEPTION) {
3169 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3170 }
3171 }
3172 #endif // SERIALGC
3173
3174 // Always call even when there are not JVMTI environments yet, since environments
3175 // may be attached late and JVMTI must track phases of VM execution
3176 JvmtiExport::enter_live_phase();
3177
3178 // Signal Dispatcher needs to be started before VMInit event is posted
3179 os::signal_init();
3180
3181 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3182 if (!DisableAttachMechanism) {
3183 if (StartAttachListener || AttachListener::init_at_startup()) {
3184 AttachListener::init();
3185 }
3186 }
3187
3188 // Launch -Xrun agents
3189 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3190 // back-end can launch with -Xdebug -Xrunjdwp.
3191 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3192 create_vm_init_libraries();
3193 }
3194
3195 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3196 JvmtiExport::post_vm_initialized();
3197
3198 Chunk::start_chunk_pool_cleaner_task();
3199
3200 // initialize compiler(s)
3201 CompileBroker::compilation_init();
3202
3203 Management::initialize(THREAD);
3204 if (HAS_PENDING_EXCEPTION) {
3205 // management agent fails to start possibly due to
3206 // configuration problem and is responsible for printing
3207 // stack trace if appropriate. Simply exit VM.
3208 vm_exit(1);
3209 }
3210
3211 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3212 if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
3213 if (MemProfiling) MemProfiler::engage();
3214 StatSampler::engage();
3215 if (CheckJNICalls) JniPeriodicChecker::engage();
3216
3217 BiasedLocking::init();
3218
3219
3220 // Start up the WatcherThread if there are any periodic tasks
3221 // NOTE: All PeriodicTasks should be registered by now. If they
3222 // aren't, late joiners might appear to start slowly (we might
3223 // take a while to process their first tick).
3224 if (PeriodicTask::num_tasks() > 0) {
3225 WatcherThread::start();
3226 }
3227
3228 create_vm_timer.end();
3229 return JNI_OK;
3230 }
3231
3232 // type for the Agent_OnLoad and JVM_OnLoad entry points
3233 extern "C" {
3234 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3235 }
3236 // Find a command line agent library and return its entry point for
3237 // -agentlib: -agentpath: -Xrun
3238 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3239 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3240 OnLoadEntry_t on_load_entry = NULL;
3241 void *library = agent->os_lib(); // check if we have looked it up before
3242
3243 if (library == NULL) {
3244 char buffer[JVM_MAXPATHLEN];
3245 char ebuf[1024];
3246 const char *name = agent->name();
3247
3248 if (agent->is_absolute_path()) {
3249 library = hpi::dll_load(name, ebuf, sizeof ebuf);
3250 if (library == NULL) {
3251 // If we can't find the agent, exit.
3252 vm_exit_during_initialization("Could not find agent library in absolute path", name);
3253 }
3254 } else {
3255 // Try to load the agent from the standard dll directory
3256 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name);
3257 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3258 #ifdef KERNEL
3259 // Download instrument dll
3260 if (library == NULL && strcmp(name, "instrument") == 0) {
3261 char *props = Arguments::get_kernel_properties();
3262 char *home = Arguments::get_java_home();
3263 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false"
3264 " sun.jkernel.DownloadManager -download client_jvm";
3265 int length = strlen(props) + strlen(home) + strlen(fmt) + 1;
3266 char *cmd = AllocateHeap(length);
3267 jio_snprintf(cmd, length, fmt, home, props);
3268 int status = os::fork_and_exec(cmd);
3269 FreeHeap(props);
3270 FreeHeap(cmd);
3271 if (status == -1) {
3272 warning(cmd);
3273 vm_exit_during_initialization("fork_and_exec failed: %s",
3274 strerror(errno));
3275 }
3276 // when this comes back the instrument.dll should be where it belongs.
3277 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3278 }
3279 #endif // KERNEL
3280 if (library == NULL) { // Try the local directory
3281 char ns[1] = {0};
3282 hpi::dll_build_name(buffer, sizeof(buffer), ns, name);
3283 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3284 if (library == NULL) {
3285 // If we can't find the agent, exit.
3286 vm_exit_during_initialization("Could not find agent library on the library path or in the local directory", name);
3287 }
3288 }
3289 }
3290 agent->set_os_lib(library);
3291 }
3292
3293 // Find the OnLoad function.
3294 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
3295 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index]));
3296 if (on_load_entry != NULL) break;
3297 }
3298 return on_load_entry;
3299 }
3300
3301 // Find the JVM_OnLoad entry point
3302 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3303 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3304 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3305 }
3306
3307 // Find the Agent_OnLoad entry point
3308 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3309 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3310 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3311 }
3312
3313 // For backwards compatibility with -Xrun
3314 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3315 // treated like -agentpath:
3316 // Must be called before agent libraries are created
3317 void Threads::convert_vm_init_libraries_to_agents() {
3318 AgentLibrary* agent;
3319 AgentLibrary* next;
3320
3321 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3322 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3323 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3324
3325 // If there is an JVM_OnLoad function it will get called later,
3326 // otherwise see if there is an Agent_OnLoad
3327 if (on_load_entry == NULL) {
3328 on_load_entry = lookup_agent_on_load(agent);
3329 if (on_load_entry != NULL) {
3330 // switch it to the agent list -- so that Agent_OnLoad will be called,
3331 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3332 Arguments::convert_library_to_agent(agent);
3333 } else {
3334 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3335 }
3336 }
3337 }
3338 }
3339
3340 // Create agents for -agentlib: -agentpath: and converted -Xrun
3341 // Invokes Agent_OnLoad
3342 // Called very early -- before JavaThreads exist
3343 void Threads::create_vm_init_agents() {
3344 extern struct JavaVM_ main_vm;
3345 AgentLibrary* agent;
3346
3347 JvmtiExport::enter_onload_phase();
3348 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3349 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3350
3351 if (on_load_entry != NULL) {
3352 // Invoke the Agent_OnLoad function
3353 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3354 if (err != JNI_OK) {
3355 vm_exit_during_initialization("agent library failed to init", agent->name());
3356 }
3357 } else {
3358 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3359 }
3360 }
3361 JvmtiExport::enter_primordial_phase();
3362 }
3363
3364 extern "C" {
3365 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3366 }
3367
3368 void Threads::shutdown_vm_agents() {
3369 // Send any Agent_OnUnload notifications
3370 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3371 extern struct JavaVM_ main_vm;
3372 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3373
3374 // Find the Agent_OnUnload function.
3375 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
3376 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3377 hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
3378
3379 // Invoke the Agent_OnUnload function
3380 if (unload_entry != NULL) {
3381 JavaThread* thread = JavaThread::current();
3382 ThreadToNativeFromVM ttn(thread);
3383 HandleMark hm(thread);
3384 (*unload_entry)(&main_vm);
3385 break;
3386 }
3387 }
3388 }
3389 }
3390
3391 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3392 // Invokes JVM_OnLoad
3393 void Threads::create_vm_init_libraries() {
3394 extern struct JavaVM_ main_vm;
3395 AgentLibrary* agent;
3396
3397 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3398 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3399
3400 if (on_load_entry != NULL) {
3401 // Invoke the JVM_OnLoad function
3402 JavaThread* thread = JavaThread::current();
3403 ThreadToNativeFromVM ttn(thread);
3404 HandleMark hm(thread);
3405 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3406 if (err != JNI_OK) {
3407 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3408 }
3409 } else {
3410 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3411 }
3412 }
3413 }
3414
3415 // Last thread running calls java.lang.Shutdown.shutdown()
3416 void JavaThread::invoke_shutdown_hooks() {
3417 HandleMark hm(this);
3418
3419 // We could get here with a pending exception, if so clear it now.
3420 if (this->has_pending_exception()) {
3421 this->clear_pending_exception();
3422 }
3423
3424 EXCEPTION_MARK;
3425 klassOop k =
3426 SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(),
3427 THREAD);
3428 if (k != NULL) {
3429 // SystemDictionary::resolve_or_null will return null if there was
3430 // an exception. If we cannot load the Shutdown class, just don't
3431 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3432 // and finalizers (if runFinalizersOnExit is set) won't be run.
3433 // Note that if a shutdown hook was registered or runFinalizersOnExit
3434 // was called, the Shutdown class would have already been loaded
3435 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3436 instanceKlassHandle shutdown_klass (THREAD, k);
3437 JavaValue result(T_VOID);
3438 JavaCalls::call_static(&result,
3439 shutdown_klass,
3440 vmSymbolHandles::shutdown_method_name(),
3441 vmSymbolHandles::void_method_signature(),
3442 THREAD);
3443 }
3444 CLEAR_PENDING_EXCEPTION;
3445 }
3446
3447 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3448 // the program falls off the end of main(). Another VM exit path is through
3449 // vm_exit() when the program calls System.exit() to return a value or when
3450 // there is a serious error in VM. The two shutdown paths are not exactly
3451 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3452 // and VM_Exit op at VM level.
3453 //
3454 // Shutdown sequence:
3455 // + Wait until we are the last non-daemon thread to execute
3456 // <-- every thing is still working at this moment -->
3457 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3458 // shutdown hooks, run finalizers if finalization-on-exit
3459 // + Call before_exit(), prepare for VM exit
3460 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3461 // currently the only user of this mechanism is File.deleteOnExit())
3462 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3463 // post thread end and vm death events to JVMTI,
3464 // stop signal thread
3465 // + Call JavaThread::exit(), it will:
3466 // > release JNI handle blocks, remove stack guard pages
3467 // > remove this thread from Threads list
3468 // <-- no more Java code from this thread after this point -->
3469 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3470 // the compiler threads at safepoint
3471 // <-- do not use anything that could get blocked by Safepoint -->
3472 // + Disable tracing at JNI/JVM barriers
3473 // + Set _vm_exited flag for threads that are still running native code
3474 // + Delete this thread
3475 // + Call exit_globals()
3476 // > deletes tty
3477 // > deletes PerfMemory resources
3478 // + Return to caller
3479
3480 bool Threads::destroy_vm() {
3481 JavaThread* thread = JavaThread::current();
3482
3483 // Wait until we are the last non-daemon thread to execute
3484 { MutexLocker nu(Threads_lock);
3485 while (Threads::number_of_non_daemon_threads() > 1 )
3486 // This wait should make safepoint checks, wait without a timeout,
3487 // and wait as a suspend-equivalent condition.
3488 //
3489 // Note: If the FlatProfiler is running and this thread is waiting
3490 // for another non-daemon thread to finish, then the FlatProfiler
3491 // is waiting for the external suspend request on this thread to
3492 // complete. wait_for_ext_suspend_completion() will eventually
3493 // timeout, but that takes time. Making this wait a suspend-
3494 // equivalent condition solves that timeout problem.
3495 //
3496 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
3497 Mutex::_as_suspend_equivalent_flag);
3498 }
3499
3500 // Hang forever on exit if we are reporting an error.
3501 if (ShowMessageBoxOnError && is_error_reported()) {
3502 os::infinite_sleep();
3503 }
3504
3505 if (JDK_Version::is_jdk12x_version()) {
3506 // We are the last thread running, so check if finalizers should be run.
3507 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
3508 HandleMark rm(thread);
3509 Universe::run_finalizers_on_exit();
3510 } else {
3511 // run Java level shutdown hooks
3512 thread->invoke_shutdown_hooks();
3513 }
3514
3515 before_exit(thread);
3516
3517 thread->exit(true);
3518
3519 // Stop VM thread.
3520 {
3521 // 4945125 The vm thread comes to a safepoint during exit.
3522 // GC vm_operations can get caught at the safepoint, and the
3523 // heap is unparseable if they are caught. Grab the Heap_lock
3524 // to prevent this. The GC vm_operations will not be able to
3525 // queue until after the vm thread is dead.
3526 MutexLocker ml(Heap_lock);
3527
3528 VMThread::wait_for_vm_thread_exit();
3529 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3530 VMThread::destroy();
3531 }
3532
3533 // clean up ideal graph printers
3534 #if defined(COMPILER2) && !defined(PRODUCT)
3535 IdealGraphPrinter::clean_up();
3536 #endif
3537
3538 // Now, all Java threads are gone except daemon threads. Daemon threads
3539 // running Java code or in VM are stopped by the Safepoint. However,
3540 // daemon threads executing native code are still running. But they
3541 // will be stopped at native=>Java/VM barriers. Note that we can't
3542 // simply kill or suspend them, as it is inherently deadlock-prone.
3543
3544 #ifndef PRODUCT
3545 // disable function tracing at JNI/JVM barriers
3546 TraceHPI = false;
3547 TraceJNICalls = false;
3548 TraceJVMCalls = false;
3549 TraceRuntimeCalls = false;
3550 #endif
3551
3552 VM_Exit::set_vm_exited();
3553
3554 notify_vm_shutdown();
3555
3556 delete thread;
3557
3558 // exit_globals() will delete tty
3559 exit_globals();
3560
3561 return true;
3562 }
3563
3564
3565 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3566 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3567 return is_supported_jni_version(version);
3568 }
3569
3570
3571 jboolean Threads::is_supported_jni_version(jint version) {
3572 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3573 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3574 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3575 return JNI_FALSE;
3576 }
3577
3578
3579 void Threads::add(JavaThread* p, bool force_daemon) {
3580 // The threads lock must be owned at this point
3581 assert_locked_or_safepoint(Threads_lock);
3582 p->set_next(_thread_list);
3583 _thread_list = p;
3584 _number_of_threads++;
3585 oop threadObj = p->threadObj();
3586 bool daemon = true;
3587 // Bootstrapping problem: threadObj can be null for initial
3588 // JavaThread (or for threads attached via JNI)
3589 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
3590 _number_of_non_daemon_threads++;
3591 daemon = false;
3592 }
3593
3594 ThreadService::add_thread(p, daemon);
3595
3596 // Possible GC point.
3597 Events::log("Thread added: " INTPTR_FORMAT, p);
3598 }
3599
3600 void Threads::remove(JavaThread* p) {
3601 // Extra scope needed for Thread_lock, so we can check
3602 // that we do not remove thread without safepoint code notice
3603 { MutexLocker ml(Threads_lock);
3604
3605 assert(includes(p), "p must be present");
3606
3607 JavaThread* current = _thread_list;
3608 JavaThread* prev = NULL;
3609
3610 while (current != p) {
3611 prev = current;
3612 current = current->next();
3613 }
3614
3615 if (prev) {
3616 prev->set_next(current->next());
3617 } else {
3618 _thread_list = p->next();
3619 }
3620 _number_of_threads--;
3621 oop threadObj = p->threadObj();
3622 bool daemon = true;
3623 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
3624 _number_of_non_daemon_threads--;
3625 daemon = false;
3626
3627 // Only one thread left, do a notify on the Threads_lock so a thread waiting
3628 // on destroy_vm will wake up.
3629 if (number_of_non_daemon_threads() == 1)
3630 Threads_lock->notify_all();
3631 }
3632 ThreadService::remove_thread(p, daemon);
3633
3634 // Make sure that safepoint code disregard this thread. This is needed since
3635 // the thread might mess around with locks after this point. This can cause it
3636 // to do callbacks into the safepoint code. However, the safepoint code is not aware
3637 // of this thread since it is removed from the queue.
3638 p->set_terminated_value();
3639 } // unlock Threads_lock
3640
3641 // Since Events::log uses a lock, we grab it outside the Threads_lock
3642 Events::log("Thread exited: " INTPTR_FORMAT, p);
3643 }
3644
3645 // Threads_lock must be held when this is called (or must be called during a safepoint)
3646 bool Threads::includes(JavaThread* p) {
3647 assert(Threads_lock->is_locked(), "sanity check");
3648 ALL_JAVA_THREADS(q) {
3649 if (q == p ) {
3650 return true;
3651 }
3652 }
3653 return false;
3654 }
3655
3656 // Operations on the Threads list for GC. These are not explicitly locked,
3657 // but the garbage collector must provide a safe context for them to run.
3658 // In particular, these things should never be called when the Threads_lock
3659 // is held by some other thread. (Note: the Safepoint abstraction also
3660 // uses the Threads_lock to gurantee this property. It also makes sure that
3661 // all threads gets blocked when exiting or starting).
3662
3663 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3664 ALL_JAVA_THREADS(p) {
3665 p->oops_do(f, cf);
3666 }
3667 VMThread::vm_thread()->oops_do(f, cf);
3668 }
3669
3670 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) {
3671 // Introduce a mechanism allowing parallel threads to claim threads as
3672 // root groups. Overhead should be small enough to use all the time,
3673 // even in sequential code.
3674 SharedHeap* sh = SharedHeap::heap();
3675 bool is_par = (sh->n_par_threads() > 0);
3676 int cp = SharedHeap::heap()->strong_roots_parity();
3677 ALL_JAVA_THREADS(p) {
3678 if (p->claim_oops_do(is_par, cp)) {
3679 p->oops_do(f, cf);
3680 }
3681 }
3682 VMThread* vmt = VMThread::vm_thread();
3683 if (vmt->claim_oops_do(is_par, cp))
3684 vmt->oops_do(f, cf);
3685 }
3686
3687 #ifndef SERIALGC
3688 // Used by ParallelScavenge
3689 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
3690 ALL_JAVA_THREADS(p) {
3691 q->enqueue(new ThreadRootsTask(p));
3692 }
3693 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
3694 }
3695
3696 // Used by Parallel Old
3697 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
3698 ALL_JAVA_THREADS(p) {
3699 q->enqueue(new ThreadRootsMarkingTask(p));
3700 }
3701 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
3702 }
3703 #endif // SERIALGC
3704
3705 void Threads::nmethods_do(CodeBlobClosure* cf) {
3706 ALL_JAVA_THREADS(p) {
3707 p->nmethods_do(cf);
3708 }
3709 VMThread::vm_thread()->nmethods_do(cf);
3710 }
3711
3712 void Threads::gc_epilogue() {
3713 ALL_JAVA_THREADS(p) {
3714 p->gc_epilogue();
3715 }
3716 }
3717
3718 void Threads::gc_prologue() {
3719 ALL_JAVA_THREADS(p) {
3720 p->gc_prologue();
3721 }
3722 }
3723
3724 void Threads::deoptimized_wrt_marked_nmethods() {
3725 ALL_JAVA_THREADS(p) {
3726 p->deoptimized_wrt_marked_nmethods();
3727 }
3728 }
3729
3730
3731 // Get count Java threads that are waiting to enter the specified monitor.
3732 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
3733 address monitor, bool doLock) {
3734 assert(doLock || SafepointSynchronize::is_at_safepoint(),
3735 "must grab Threads_lock or be at safepoint");
3736 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
3737
3738 int i = 0;
3739 {
3740 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3741 ALL_JAVA_THREADS(p) {
3742 if (p->is_Compiler_thread()) continue;
3743
3744 address pending = (address)p->current_pending_monitor();
3745 if (pending == monitor) { // found a match
3746 if (i < count) result->append(p); // save the first count matches
3747 i++;
3748 }
3749 }
3750 }
3751 return result;
3752 }
3753
3754
3755 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
3756 assert(doLock ||
3757 Threads_lock->owned_by_self() ||
3758 SafepointSynchronize::is_at_safepoint(),
3759 "must grab Threads_lock or be at safepoint");
3760
3761 // NULL owner means not locked so we can skip the search
3762 if (owner == NULL) return NULL;
3763
3764 {
3765 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3766 ALL_JAVA_THREADS(p) {
3767 // first, see if owner is the address of a Java thread
3768 if (owner == (address)p) return p;
3769 }
3770 }
3771 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
3772 if (UseHeavyMonitors) return NULL;
3773
3774 //
3775 // If we didn't find a matching Java thread and we didn't force use of
3776 // heavyweight monitors, then the owner is the stack address of the
3777 // Lock Word in the owning Java thread's stack.
3778 //
3779 JavaThread* the_owner = NULL;
3780 {
3781 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3782 ALL_JAVA_THREADS(q) {
3783 if (q->is_lock_owned(owner)) {
3784 the_owner = q;
3785 break;
3786 }
3787 }
3788 }
3789 assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
3790 return the_owner;
3791 }
3792
3793 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
3794 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
3795 char buf[32];
3796 st->print_cr(os::local_time_string(buf, sizeof(buf)));
3797
3798 st->print_cr("Full thread dump %s (%s %s):",
3799 Abstract_VM_Version::vm_name(),
3800 Abstract_VM_Version::vm_release(),
3801 Abstract_VM_Version::vm_info_string()
3802 );
3803 st->cr();
3804
3805 #ifndef SERIALGC
3806 // Dump concurrent locks
3807 ConcurrentLocksDump concurrent_locks;
3808 if (print_concurrent_locks) {
3809 concurrent_locks.dump_at_safepoint();
3810 }
3811 #endif // SERIALGC
3812
3813 ALL_JAVA_THREADS(p) {
3814 ResourceMark rm;
3815 p->print_on(st);
3816 if (print_stacks) {
3817 if (internal_format) {
3818 p->trace_stack();
3819 } else {
3820 p->print_stack_on(st);
3821 }
3822 }
3823 st->cr();
3824 #ifndef SERIALGC
3825 if (print_concurrent_locks) {
3826 concurrent_locks.print_locks_on(p, st);
3827 }
3828 #endif // SERIALGC
3829 }
3830
3831 VMThread::vm_thread()->print_on(st);
3832 st->cr();
3833 Universe::heap()->print_gc_threads_on(st);
3834 WatcherThread* wt = WatcherThread::watcher_thread();
3835 if (wt != NULL) wt->print_on(st);
3836 st->cr();
3837 CompileBroker::print_compiler_threads_on(st);
3838 st->flush();
3839 }
3840
3841 // Threads::print_on_error() is called by fatal error handler. It's possible
3842 // that VM is not at safepoint and/or current thread is inside signal handler.
3843 // Don't print stack trace, as the stack may not be walkable. Don't allocate
3844 // memory (even in resource area), it might deadlock the error handler.
3845 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
3846 bool found_current = false;
3847 st->print_cr("Java Threads: ( => current thread )");
3848 ALL_JAVA_THREADS(thread) {
3849 bool is_current = (current == thread);
3850 found_current = found_current || is_current;
3851
3852 st->print("%s", is_current ? "=>" : " ");
3853
3854 st->print(PTR_FORMAT, thread);
3855 st->print(" ");
3856 thread->print_on_error(st, buf, buflen);
3857 st->cr();
3858 }
3859 st->cr();
3860
3861 st->print_cr("Other Threads:");
3862 if (VMThread::vm_thread()) {
3863 bool is_current = (current == VMThread::vm_thread());
3864 found_current = found_current || is_current;
3865 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
3866
3867 st->print(PTR_FORMAT, VMThread::vm_thread());
3868 st->print(" ");
3869 VMThread::vm_thread()->print_on_error(st, buf, buflen);
3870 st->cr();
3871 }
3872 WatcherThread* wt = WatcherThread::watcher_thread();
3873 if (wt != NULL) {
3874 bool is_current = (current == wt);
3875 found_current = found_current || is_current;
3876 st->print("%s", is_current ? "=>" : " ");
3877
3878 st->print(PTR_FORMAT, wt);
3879 st->print(" ");
3880 wt->print_on_error(st, buf, buflen);
3881 st->cr();
3882 }
3883 if (!found_current) {
3884 st->cr();
3885 st->print("=>" PTR_FORMAT " (exited) ", current);
3886 current->print_on_error(st, buf, buflen);
3887 st->cr();
3888 }
3889 }
3890
3891
3892 // Lifecycle management for TSM ParkEvents.
3893 // ParkEvents are type-stable (TSM).
3894 // In our particular implementation they happen to be immortal.
3895 //
3896 // We manage concurrency on the FreeList with a CAS-based
3897 // detach-modify-reattach idiom that avoids the ABA problems
3898 // that would otherwise be present in a simple CAS-based
3899 // push-pop implementation. (push-one and pop-all)
3900 //
3901 // Caveat: Allocate() and Release() may be called from threads
3902 // other than the thread associated with the Event!
3903 // If we need to call Allocate() when running as the thread in
3904 // question then look for the PD calls to initialize native TLS.
3905 // Native TLS (Win32/Linux/Solaris) can only be initialized or
3906 // accessed by the associated thread.
3907 // See also pd_initialize().
3908 //
3909 // Note that we could defer associating a ParkEvent with a thread
3910 // until the 1st time the thread calls park(). unpark() calls to
3911 // an unprovisioned thread would be ignored. The first park() call
3912 // for a thread would allocate and associate a ParkEvent and return
3913 // immediately.
3914
3915 volatile int ParkEvent::ListLock = 0 ;
3916 ParkEvent * volatile ParkEvent::FreeList = NULL ;
3917
3918 ParkEvent * ParkEvent::Allocate (Thread * t) {
3919 // In rare cases -- JVM_RawMonitor* operations -- we can find t == null.
3920 ParkEvent * ev ;
3921
3922 // Start by trying to recycle an existing but unassociated
3923 // ParkEvent from the global free list.
3924 for (;;) {
3925 ev = FreeList ;
3926 if (ev == NULL) break ;
3927 // 1: Detach - sequester or privatize the list
3928 // Tantamount to ev = Swap (&FreeList, NULL)
3929 if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) {
3930 continue ;
3931 }
3932
3933 // We've detached the list. The list in-hand is now
3934 // local to this thread. This thread can operate on the
3935 // list without risk of interference from other threads.
3936 // 2: Extract -- pop the 1st element from the list.
3937 ParkEvent * List = ev->FreeNext ;
3938 if (List == NULL) break ;
3939 for (;;) {
3940 // 3: Try to reattach the residual list
3941 guarantee (List != NULL, "invariant") ;
3942 ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
3943 if (Arv == NULL) break ;
3944
3945 // New nodes arrived. Try to detach the recent arrivals.
3946 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
3947 continue ;
3948 }
3949 guarantee (Arv != NULL, "invariant") ;
3950 // 4: Merge Arv into List
3951 ParkEvent * Tail = List ;
3952 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
3953 Tail->FreeNext = Arv ;
3954 }
3955 break ;
3956 }
3957
3958 if (ev != NULL) {
3959 guarantee (ev->AssociatedWith == NULL, "invariant") ;
3960 } else {
3961 // Do this the hard way -- materialize a new ParkEvent.
3962 // In rare cases an allocating thread might detach a long list --
3963 // installing null into FreeList -- and then stall or be obstructed.
3964 // A 2nd thread calling Allocate() would see FreeList == null.
3965 // The list held privately by the 1st thread is unavailable to the 2nd thread.
3966 // In that case the 2nd thread would have to materialize a new ParkEvent,
3967 // even though free ParkEvents existed in the system. In this case we end up
3968 // with more ParkEvents in circulation than we need, but the race is
3969 // rare and the outcome is benign. Ideally, the # of extant ParkEvents
3970 // is equal to the maximum # of threads that existed at any one time.
3971 // Because of the race mentioned above, segments of the freelist
3972 // can be transiently inaccessible. At worst we may end up with the
3973 // # of ParkEvents in circulation slightly above the ideal.
3974 // Note that if we didn't have the TSM/immortal constraint, then
3975 // when reattaching, above, we could trim the list.
3976 ev = new ParkEvent () ;
3977 guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ;
3978 }
3979 ev->reset() ; // courtesy to caller
3980 ev->AssociatedWith = t ; // Associate ev with t
3981 ev->FreeNext = NULL ;
3982 return ev ;
3983 }
3984
3985 void ParkEvent::Release (ParkEvent * ev) {
3986 if (ev == NULL) return ;
3987 guarantee (ev->FreeNext == NULL , "invariant") ;
3988 ev->AssociatedWith = NULL ;
3989 for (;;) {
3990 // Push ev onto FreeList
3991 // The mechanism is "half" lock-free.
3992 ParkEvent * List = FreeList ;
3993 ev->FreeNext = List ;
3994 if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ;
3995 }
3996 }
3997
3998 // Override operator new and delete so we can ensure that the
3999 // least significant byte of ParkEvent addresses is 0.
4000 // Beware that excessive address alignment is undesirable
4001 // as it can result in D$ index usage imbalance as
4002 // well as bank access imbalance on Niagara-like platforms,
4003 // although Niagara's hash function should help.
4004
4005 void * ParkEvent::operator new (size_t sz) {
4006 return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ;
4007 }
4008
4009 void ParkEvent::operator delete (void * a) {
4010 // ParkEvents are type-stable and immortal ...
4011 ShouldNotReachHere();
4012 }
4013
4014
4015 // 6399321 As a temporary measure we copied & modified the ParkEvent::
4016 // allocate() and release() code for use by Parkers. The Parker:: forms
4017 // will eventually be removed as we consolide and shift over to ParkEvents
4018 // for both builtin synchronization and JSR166 operations.
4019
4020 volatile int Parker::ListLock = 0 ;
4021 Parker * volatile Parker::FreeList = NULL ;
4022
4023 Parker * Parker::Allocate (JavaThread * t) {
4024 guarantee (t != NULL, "invariant") ;
4025 Parker * p ;
4026
4027 // Start by trying to recycle an existing but unassociated
4028 // Parker from the global free list.
4029 for (;;) {
4030 p = FreeList ;
4031 if (p == NULL) break ;
4032 // 1: Detach
4033 // Tantamount to p = Swap (&FreeList, NULL)
4034 if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) {
4035 continue ;
4036 }
4037
4038 // We've detached the list. The list in-hand is now
4039 // local to this thread. This thread can operate on the
4040 // list without risk of interference from other threads.
4041 // 2: Extract -- pop the 1st element from the list.
4042 Parker * List = p->FreeNext ;
4043 if (List == NULL) break ;
4044 for (;;) {
4045 // 3: Try to reattach the residual list
4046 guarantee (List != NULL, "invariant") ;
4047 Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
4048 if (Arv == NULL) break ;
4049
4050 // New nodes arrived. Try to detach the recent arrivals.
4051 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
4052 continue ;
4053 }
4054 guarantee (Arv != NULL, "invariant") ;
4055 // 4: Merge Arv into List
4056 Parker * Tail = List ;
4057 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
4058 Tail->FreeNext = Arv ;
4059 }
4060 break ;
4061 }
4062
4063 if (p != NULL) {
4064 guarantee (p->AssociatedWith == NULL, "invariant") ;
4065 } else {
4066 // Do this the hard way -- materialize a new Parker..
4067 // In rare cases an allocating thread might detach
4068 // a long list -- installing null into FreeList --and
4069 // then stall. Another thread calling Allocate() would see
4070 // FreeList == null and then invoke the ctor. In this case we
4071 // end up with more Parkers in circulation than we need, but
4072 // the race is rare and the outcome is benign.
4073 // Ideally, the # of extant Parkers is equal to the
4074 // maximum # of threads that existed at any one time.
4075 // Because of the race mentioned above, segments of the
4076 // freelist can be transiently inaccessible. At worst
4077 // we may end up with the # of Parkers in circulation
4078 // slightly above the ideal.
4079 p = new Parker() ;
4080 }
4081 p->AssociatedWith = t ; // Associate p with t
4082 p->FreeNext = NULL ;
4083 return p ;
4084 }
4085
4086
4087 void Parker::Release (Parker * p) {
4088 if (p == NULL) return ;
4089 guarantee (p->AssociatedWith != NULL, "invariant") ;
4090 guarantee (p->FreeNext == NULL , "invariant") ;
4091 p->AssociatedWith = NULL ;
4092 for (;;) {
4093 // Push p onto FreeList
4094 Parker * List = FreeList ;
4095 p->FreeNext = List ;
4096 if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ;
4097 }
4098 }
4099
4100 void Threads::verify() {
4101 ALL_JAVA_THREADS(p) {
4102 p->verify();
4103 }
4104 VMThread* thread = VMThread::vm_thread();
4105 if (thread != NULL) thread->verify();
4106 }