1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 # include "incls/_precompiled.incl"
26 # include "incls/_thread.cpp.incl"
27
28 #ifdef DTRACE_ENABLED
29
30 // Only bother with this argument setup if dtrace is available
31
32 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin);
33 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end);
34 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t,
35 intptr_t, intptr_t, bool);
36 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t,
37 intptr_t, intptr_t, bool);
38
39 #define DTRACE_THREAD_PROBE(probe, javathread) \
40 { \
41 ResourceMark rm(this); \
42 int len = 0; \
43 const char* name = (javathread)->get_thread_name(); \
44 len = strlen(name); \
45 HS_DTRACE_PROBE5(hotspot, thread__##probe, \
46 name, len, \
47 java_lang_Thread::thread_id((javathread)->threadObj()), \
48 (javathread)->osthread()->thread_id(), \
49 java_lang_Thread::is_daemon((javathread)->threadObj())); \
50 }
51
52 #else // ndef DTRACE_ENABLED
53
54 #define DTRACE_THREAD_PROBE(probe, javathread)
55
56 #endif // ndef DTRACE_ENABLED
57
58 // Class hierarchy
59 // - Thread
60 // - VMThread
61 // - WatcherThread
62 // - ConcurrentMarkSweepThread
63 // - JavaThread
64 // - CompilerThread
65
66 // ======= Thread ========
67
68 // Support for forcing alignment of thread objects for biased locking
69 void* Thread::operator new(size_t size) {
70 if (UseBiasedLocking) {
71 const int alignment = markOopDesc::biased_lock_alignment;
72 size_t aligned_size = size + (alignment - sizeof(intptr_t));
73 void* real_malloc_addr = CHeapObj::operator new(aligned_size);
74 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment);
75 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
76 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
77 "JavaThread alignment code overflowed allocated storage");
78 if (TraceBiasedLocking) {
79 if (aligned_addr != real_malloc_addr)
80 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
81 real_malloc_addr, aligned_addr);
82 }
83 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
84 return aligned_addr;
85 } else {
86 return CHeapObj::operator new(size);
87 }
88 }
89
90 void Thread::operator delete(void* p) {
91 if (UseBiasedLocking) {
92 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
93 CHeapObj::operator delete(real_malloc_addr);
94 } else {
95 CHeapObj::operator delete(p);
96 }
97 }
98
99
100 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
101 // JavaThread
102
103
104 Thread::Thread() {
105 // stack
106 _stack_base = NULL;
107 _stack_size = 0;
108 _self_raw_id = 0;
109 _lgrp_id = -1;
110 _osthread = NULL;
111
112 // allocated data structures
113 set_resource_area(new ResourceArea());
114 set_handle_area(new HandleArea(NULL));
115 set_active_handles(NULL);
116 set_free_handle_block(NULL);
117 set_last_handle_mark(NULL);
118 set_osthread(NULL);
119
120 // This initial value ==> never claimed.
121 _oops_do_parity = 0;
122
123 // the handle mark links itself to last_handle_mark
124 new HandleMark(this);
125
126 // plain initialization
127 debug_only(_owned_locks = NULL;)
128 debug_only(_allow_allocation_count = 0;)
129 NOT_PRODUCT(_allow_safepoint_count = 0;)
130 NOT_PRODUCT(_skip_gcalot = false;)
131 CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;)
132 _jvmti_env_iteration_count = 0;
133 _vm_operation_started_count = 0;
134 _vm_operation_completed_count = 0;
135 _current_pending_monitor = NULL;
136 _current_pending_monitor_is_from_java = true;
137 _current_waiting_monitor = NULL;
138 _num_nested_signal = 0;
139 omFreeList = NULL ;
140 omFreeCount = 0 ;
141 omFreeProvision = 32 ;
142 omInUseList = NULL ;
143 omInUseCount = 0 ;
144
145 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
146 _suspend_flags = 0;
147
148 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
149 _hashStateX = os::random() ;
150 _hashStateY = 842502087 ;
151 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
152 _hashStateW = 273326509 ;
153
154 _OnTrap = 0 ;
155 _schedctl = NULL ;
156 _Stalled = 0 ;
157 _TypeTag = 0x2BAD ;
158
159 // Many of the following fields are effectively final - immutable
160 // Note that nascent threads can't use the Native Monitor-Mutex
161 // construct until the _MutexEvent is initialized ...
162 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
163 // we might instead use a stack of ParkEvents that we could provision on-demand.
164 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
165 // and ::Release()
166 _ParkEvent = ParkEvent::Allocate (this) ;
167 _SleepEvent = ParkEvent::Allocate (this) ;
168 _MutexEvent = ParkEvent::Allocate (this) ;
169 _MuxEvent = ParkEvent::Allocate (this) ;
170
171 #ifdef CHECK_UNHANDLED_OOPS
172 if (CheckUnhandledOops) {
173 _unhandled_oops = new UnhandledOops(this);
174 }
175 #endif // CHECK_UNHANDLED_OOPS
176 #ifdef ASSERT
177 if (UseBiasedLocking) {
178 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
179 assert(this == _real_malloc_address ||
180 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
181 "bug in forced alignment of thread objects");
182 }
183 #endif /* ASSERT */
184 }
185
186 void Thread::initialize_thread_local_storage() {
187 // Note: Make sure this method only calls
188 // non-blocking operations. Otherwise, it might not work
189 // with the thread-startup/safepoint interaction.
190
191 // During Java thread startup, safepoint code should allow this
192 // method to complete because it may need to allocate memory to
193 // store information for the new thread.
194
195 // initialize structure dependent on thread local storage
196 ThreadLocalStorage::set_thread(this);
197
198 // set up any platform-specific state.
199 os::initialize_thread();
200
201 }
202
203 void Thread::record_stack_base_and_size() {
204 set_stack_base(os::current_stack_base());
205 set_stack_size(os::current_stack_size());
206 }
207
208
209 Thread::~Thread() {
210 // Reclaim the objectmonitors from the omFreeList of the moribund thread.
211 ObjectSynchronizer::omFlush (this) ;
212
213 // deallocate data structures
214 delete resource_area();
215 // since the handle marks are using the handle area, we have to deallocated the root
216 // handle mark before deallocating the thread's handle area,
217 assert(last_handle_mark() != NULL, "check we have an element");
218 delete last_handle_mark();
219 assert(last_handle_mark() == NULL, "check we have reached the end");
220
221 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
222 // We NULL out the fields for good hygiene.
223 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
224 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
225 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
226 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
227
228 delete handle_area();
229
230 // osthread() can be NULL, if creation of thread failed.
231 if (osthread() != NULL) os::free_thread(osthread());
232
233 delete _SR_lock;
234
235 // clear thread local storage if the Thread is deleting itself
236 if (this == Thread::current()) {
237 ThreadLocalStorage::set_thread(NULL);
238 } else {
239 // In the case where we're not the current thread, invalidate all the
240 // caches in case some code tries to get the current thread or the
241 // thread that was destroyed, and gets stale information.
242 ThreadLocalStorage::invalidate_all();
243 }
244 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
245 }
246
247 // NOTE: dummy function for assertion purpose.
248 void Thread::run() {
249 ShouldNotReachHere();
250 }
251
252 #ifdef ASSERT
253 // Private method to check for dangling thread pointer
254 void check_for_dangling_thread_pointer(Thread *thread) {
255 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
256 "possibility of dangling Thread pointer");
257 }
258 #endif
259
260
261 #ifndef PRODUCT
262 // Tracing method for basic thread operations
263 void Thread::trace(const char* msg, const Thread* const thread) {
264 if (!TraceThreadEvents) return;
265 ResourceMark rm;
266 ThreadCritical tc;
267 const char *name = "non-Java thread";
268 int prio = -1;
269 if (thread->is_Java_thread()
270 && !thread->is_Compiler_thread()) {
271 // The Threads_lock must be held to get information about
272 // this thread but may not be in some situations when
273 // tracing thread events.
274 bool release_Threads_lock = false;
275 if (!Threads_lock->owned_by_self()) {
276 Threads_lock->lock();
277 release_Threads_lock = true;
278 }
279 JavaThread* jt = (JavaThread *)thread;
280 name = (char *)jt->get_thread_name();
281 oop thread_oop = jt->threadObj();
282 if (thread_oop != NULL) {
283 prio = java_lang_Thread::priority(thread_oop);
284 }
285 if (release_Threads_lock) {
286 Threads_lock->unlock();
287 }
288 }
289 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
290 }
291 #endif
292
293
294 ThreadPriority Thread::get_priority(const Thread* const thread) {
295 trace("get priority", thread);
296 ThreadPriority priority;
297 // Can return an error!
298 (void)os::get_priority(thread, priority);
299 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
300 return priority;
301 }
302
303 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
304 trace("set priority", thread);
305 debug_only(check_for_dangling_thread_pointer(thread);)
306 // Can return an error!
307 (void)os::set_priority(thread, priority);
308 }
309
310
311 void Thread::start(Thread* thread) {
312 trace("start", thread);
313 // Start is different from resume in that its safety is guaranteed by context or
314 // being called from a Java method synchronized on the Thread object.
315 if (!DisableStartThread) {
316 if (thread->is_Java_thread()) {
317 // Initialize the thread state to RUNNABLE before starting this thread.
318 // Can not set it after the thread started because we do not know the
319 // exact thread state at that time. It could be in MONITOR_WAIT or
320 // in SLEEPING or some other state.
321 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
322 java_lang_Thread::RUNNABLE);
323 }
324 os::start_thread(thread);
325 }
326 }
327
328 // Enqueue a VM_Operation to do the job for us - sometime later
329 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
330 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
331 VMThread::execute(vm_stop);
332 }
333
334
335 //
336 // Check if an external suspend request has completed (or has been
337 // cancelled). Returns true if the thread is externally suspended and
338 // false otherwise.
339 //
340 // The bits parameter returns information about the code path through
341 // the routine. Useful for debugging:
342 //
343 // set in is_ext_suspend_completed():
344 // 0x00000001 - routine was entered
345 // 0x00000010 - routine return false at end
346 // 0x00000100 - thread exited (return false)
347 // 0x00000200 - suspend request cancelled (return false)
348 // 0x00000400 - thread suspended (return true)
349 // 0x00001000 - thread is in a suspend equivalent state (return true)
350 // 0x00002000 - thread is native and walkable (return true)
351 // 0x00004000 - thread is native_trans and walkable (needed retry)
352 //
353 // set in wait_for_ext_suspend_completion():
354 // 0x00010000 - routine was entered
355 // 0x00020000 - suspend request cancelled before loop (return false)
356 // 0x00040000 - thread suspended before loop (return true)
357 // 0x00080000 - suspend request cancelled in loop (return false)
358 // 0x00100000 - thread suspended in loop (return true)
359 // 0x00200000 - suspend not completed during retry loop (return false)
360 //
361
362 // Helper class for tracing suspend wait debug bits.
363 //
364 // 0x00000100 indicates that the target thread exited before it could
365 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
366 // 0x00080000 each indicate a cancelled suspend request so they don't
367 // count as wait failures either.
368 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
369
370 class TraceSuspendDebugBits : public StackObj {
371 private:
372 JavaThread * jt;
373 bool is_wait;
374 bool called_by_wait; // meaningful when !is_wait
375 uint32_t * bits;
376
377 public:
378 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
379 uint32_t *_bits) {
380 jt = _jt;
381 is_wait = _is_wait;
382 called_by_wait = _called_by_wait;
383 bits = _bits;
384 }
385
386 ~TraceSuspendDebugBits() {
387 if (!is_wait) {
388 #if 1
389 // By default, don't trace bits for is_ext_suspend_completed() calls.
390 // That trace is very chatty.
391 return;
392 #else
393 if (!called_by_wait) {
394 // If tracing for is_ext_suspend_completed() is enabled, then only
395 // trace calls to it from wait_for_ext_suspend_completion()
396 return;
397 }
398 #endif
399 }
400
401 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
402 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
403 MutexLocker ml(Threads_lock); // needed for get_thread_name()
404 ResourceMark rm;
405
406 tty->print_cr(
407 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
408 jt->get_thread_name(), *bits);
409
410 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
411 }
412 }
413 }
414 };
415 #undef DEBUG_FALSE_BITS
416
417
418 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
419 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
420
421 bool did_trans_retry = false; // only do thread_in_native_trans retry once
422 bool do_trans_retry; // flag to force the retry
423
424 *bits |= 0x00000001;
425
426 do {
427 do_trans_retry = false;
428
429 if (is_exiting()) {
430 // Thread is in the process of exiting. This is always checked
431 // first to reduce the risk of dereferencing a freed JavaThread.
432 *bits |= 0x00000100;
433 return false;
434 }
435
436 if (!is_external_suspend()) {
437 // Suspend request is cancelled. This is always checked before
438 // is_ext_suspended() to reduce the risk of a rogue resume
439 // confusing the thread that made the suspend request.
440 *bits |= 0x00000200;
441 return false;
442 }
443
444 if (is_ext_suspended()) {
445 // thread is suspended
446 *bits |= 0x00000400;
447 return true;
448 }
449
450 // Now that we no longer do hard suspends of threads running
451 // native code, the target thread can be changing thread state
452 // while we are in this routine:
453 //
454 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
455 //
456 // We save a copy of the thread state as observed at this moment
457 // and make our decision about suspend completeness based on the
458 // copy. This closes the race where the thread state is seen as
459 // _thread_in_native_trans in the if-thread_blocked check, but is
460 // seen as _thread_blocked in if-thread_in_native_trans check.
461 JavaThreadState save_state = thread_state();
462
463 if (save_state == _thread_blocked && is_suspend_equivalent()) {
464 // If the thread's state is _thread_blocked and this blocking
465 // condition is known to be equivalent to a suspend, then we can
466 // consider the thread to be externally suspended. This means that
467 // the code that sets _thread_blocked has been modified to do
468 // self-suspension if the blocking condition releases. We also
469 // used to check for CONDVAR_WAIT here, but that is now covered by
470 // the _thread_blocked with self-suspension check.
471 //
472 // Return true since we wouldn't be here unless there was still an
473 // external suspend request.
474 *bits |= 0x00001000;
475 return true;
476 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
477 // Threads running native code will self-suspend on native==>VM/Java
478 // transitions. If its stack is walkable (should always be the case
479 // unless this function is called before the actual java_suspend()
480 // call), then the wait is done.
481 *bits |= 0x00002000;
482 return true;
483 } else if (!called_by_wait && !did_trans_retry &&
484 save_state == _thread_in_native_trans &&
485 frame_anchor()->walkable()) {
486 // The thread is transitioning from thread_in_native to another
487 // thread state. check_safepoint_and_suspend_for_native_trans()
488 // will force the thread to self-suspend. If it hasn't gotten
489 // there yet we may have caught the thread in-between the native
490 // code check above and the self-suspend. Lucky us. If we were
491 // called by wait_for_ext_suspend_completion(), then it
492 // will be doing the retries so we don't have to.
493 //
494 // Since we use the saved thread state in the if-statement above,
495 // there is a chance that the thread has already transitioned to
496 // _thread_blocked by the time we get here. In that case, we will
497 // make a single unnecessary pass through the logic below. This
498 // doesn't hurt anything since we still do the trans retry.
499
500 *bits |= 0x00004000;
501
502 // Once the thread leaves thread_in_native_trans for another
503 // thread state, we break out of this retry loop. We shouldn't
504 // need this flag to prevent us from getting back here, but
505 // sometimes paranoia is good.
506 did_trans_retry = true;
507
508 // We wait for the thread to transition to a more usable state.
509 for (int i = 1; i <= SuspendRetryCount; i++) {
510 // We used to do an "os::yield_all(i)" call here with the intention
511 // that yielding would increase on each retry. However, the parameter
512 // is ignored on Linux which means the yield didn't scale up. Waiting
513 // on the SR_lock below provides a much more predictable scale up for
514 // the delay. It also provides a simple/direct point to check for any
515 // safepoint requests from the VMThread
516
517 // temporarily drops SR_lock while doing wait with safepoint check
518 // (if we're a JavaThread - the WatcherThread can also call this)
519 // and increase delay with each retry
520 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
521
522 // check the actual thread state instead of what we saved above
523 if (thread_state() != _thread_in_native_trans) {
524 // the thread has transitioned to another thread state so
525 // try all the checks (except this one) one more time.
526 do_trans_retry = true;
527 break;
528 }
529 } // end retry loop
530
531
532 }
533 } while (do_trans_retry);
534
535 *bits |= 0x00000010;
536 return false;
537 }
538
539 //
540 // Wait for an external suspend request to complete (or be cancelled).
541 // Returns true if the thread is externally suspended and false otherwise.
542 //
543 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
544 uint32_t *bits) {
545 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
546 false /* !called_by_wait */, bits);
547
548 // local flag copies to minimize SR_lock hold time
549 bool is_suspended;
550 bool pending;
551 uint32_t reset_bits;
552
553 // set a marker so is_ext_suspend_completed() knows we are the caller
554 *bits |= 0x00010000;
555
556 // We use reset_bits to reinitialize the bits value at the top of
557 // each retry loop. This allows the caller to make use of any
558 // unused bits for their own marking purposes.
559 reset_bits = *bits;
560
561 {
562 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
563 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
564 delay, bits);
565 pending = is_external_suspend();
566 }
567 // must release SR_lock to allow suspension to complete
568
569 if (!pending) {
570 // A cancelled suspend request is the only false return from
571 // is_ext_suspend_completed() that keeps us from entering the
572 // retry loop.
573 *bits |= 0x00020000;
574 return false;
575 }
576
577 if (is_suspended) {
578 *bits |= 0x00040000;
579 return true;
580 }
581
582 for (int i = 1; i <= retries; i++) {
583 *bits = reset_bits; // reinit to only track last retry
584
585 // We used to do an "os::yield_all(i)" call here with the intention
586 // that yielding would increase on each retry. However, the parameter
587 // is ignored on Linux which means the yield didn't scale up. Waiting
588 // on the SR_lock below provides a much more predictable scale up for
589 // the delay. It also provides a simple/direct point to check for any
590 // safepoint requests from the VMThread
591
592 {
593 MutexLocker ml(SR_lock());
594 // wait with safepoint check (if we're a JavaThread - the WatcherThread
595 // can also call this) and increase delay with each retry
596 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
597
598 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
599 delay, bits);
600
601 // It is possible for the external suspend request to be cancelled
602 // (by a resume) before the actual suspend operation is completed.
603 // Refresh our local copy to see if we still need to wait.
604 pending = is_external_suspend();
605 }
606
607 if (!pending) {
608 // A cancelled suspend request is the only false return from
609 // is_ext_suspend_completed() that keeps us from staying in the
610 // retry loop.
611 *bits |= 0x00080000;
612 return false;
613 }
614
615 if (is_suspended) {
616 *bits |= 0x00100000;
617 return true;
618 }
619 } // end retry loop
620
621 // thread did not suspend after all our retries
622 *bits |= 0x00200000;
623 return false;
624 }
625
626 #ifndef PRODUCT
627 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
628
629 // This should not need to be atomic as the only way for simultaneous
630 // updates is via interrupts. Even then this should be rare or non-existant
631 // and we don't care that much anyway.
632
633 int index = _jmp_ring_index;
634 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
635 _jmp_ring[index]._target = (intptr_t) target;
636 _jmp_ring[index]._instruction = (intptr_t) instr;
637 _jmp_ring[index]._file = file;
638 _jmp_ring[index]._line = line;
639 }
640 #endif /* PRODUCT */
641
642 // Called by flat profiler
643 // Callers have already called wait_for_ext_suspend_completion
644 // The assertion for that is currently too complex to put here:
645 bool JavaThread::profile_last_Java_frame(frame* _fr) {
646 bool gotframe = false;
647 // self suspension saves needed state.
648 if (has_last_Java_frame() && _anchor.walkable()) {
649 *_fr = pd_last_frame();
650 gotframe = true;
651 }
652 return gotframe;
653 }
654
655 void Thread::interrupt(Thread* thread) {
656 trace("interrupt", thread);
657 debug_only(check_for_dangling_thread_pointer(thread);)
658 os::interrupt(thread);
659 }
660
661 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
662 trace("is_interrupted", thread);
663 debug_only(check_for_dangling_thread_pointer(thread);)
664 // Note: If clear_interrupted==false, this simply fetches and
665 // returns the value of the field osthread()->interrupted().
666 return os::is_interrupted(thread, clear_interrupted);
667 }
668
669
670 // GC Support
671 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
672 jint thread_parity = _oops_do_parity;
673 if (thread_parity != strong_roots_parity) {
674 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
675 if (res == thread_parity) return true;
676 else {
677 guarantee(res == strong_roots_parity, "Or else what?");
678 assert(SharedHeap::heap()->n_par_threads() > 0,
679 "Should only fail when parallel.");
680 return false;
681 }
682 }
683 assert(SharedHeap::heap()->n_par_threads() > 0,
684 "Should only fail when parallel.");
685 return false;
686 }
687
688 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
689 active_handles()->oops_do(f);
690 // Do oop for ThreadShadow
691 f->do_oop((oop*)&_pending_exception);
692 handle_area()->oops_do(f);
693 }
694
695 void Thread::nmethods_do(CodeBlobClosure* cf) {
696 // no nmethods in a generic thread...
697 }
698
699 void Thread::print_on(outputStream* st) const {
700 // get_priority assumes osthread initialized
701 if (osthread() != NULL) {
702 st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this);
703 osthread()->print_on(st);
704 }
705 debug_only(if (WizardMode) print_owned_locks_on(st);)
706 }
707
708 // Thread::print_on_error() is called by fatal error handler. Don't use
709 // any lock or allocate memory.
710 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
711 if (is_VM_thread()) st->print("VMThread");
712 else if (is_Compiler_thread()) st->print("CompilerThread");
713 else if (is_Java_thread()) st->print("JavaThread");
714 else if (is_GC_task_thread()) st->print("GCTaskThread");
715 else if (is_Watcher_thread()) st->print("WatcherThread");
716 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
717 else st->print("Thread");
718
719 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
720 _stack_base - _stack_size, _stack_base);
721
722 if (osthread()) {
723 st->print(" [id=%d]", osthread()->thread_id());
724 }
725 }
726
727 #ifdef ASSERT
728 void Thread::print_owned_locks_on(outputStream* st) const {
729 Monitor *cur = _owned_locks;
730 if (cur == NULL) {
731 st->print(" (no locks) ");
732 } else {
733 st->print_cr(" Locks owned:");
734 while(cur) {
735 cur->print_on(st);
736 cur = cur->next();
737 }
738 }
739 }
740
741 static int ref_use_count = 0;
742
743 bool Thread::owns_locks_but_compiled_lock() const {
744 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
745 if (cur != Compile_lock) return true;
746 }
747 return false;
748 }
749
750
751 #endif
752
753 #ifndef PRODUCT
754
755 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
756 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
757 // no threads which allow_vm_block's are held
758 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
759 // Check if current thread is allowed to block at a safepoint
760 if (!(_allow_safepoint_count == 0))
761 fatal("Possible safepoint reached by thread that does not allow it");
762 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
763 fatal("LEAF method calling lock?");
764 }
765
766 #ifdef ASSERT
767 if (potential_vm_operation && is_Java_thread()
768 && !Universe::is_bootstrapping()) {
769 // Make sure we do not hold any locks that the VM thread also uses.
770 // This could potentially lead to deadlocks
771 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
772 // Threads_lock is special, since the safepoint synchronization will not start before this is
773 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
774 // since it is used to transfer control between JavaThreads and the VMThread
775 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
776 if ( (cur->allow_vm_block() &&
777 cur != Threads_lock &&
778 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
779 cur != VMOperationRequest_lock &&
780 cur != VMOperationQueue_lock) ||
781 cur->rank() == Mutex::special) {
782 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
783 }
784 }
785 }
786
787 if (GCALotAtAllSafepoints) {
788 // We could enter a safepoint here and thus have a gc
789 InterfaceSupport::check_gc_alot();
790 }
791 #endif
792 }
793 #endif
794
795 bool Thread::is_in_stack(address adr) const {
796 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
797 address end = os::current_stack_pointer();
798 if (stack_base() >= adr && adr >= end) return true;
799
800 return false;
801 }
802
803
804 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
805 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
806 // used for compilation in the future. If that change is made, the need for these methods
807 // should be revisited, and they should be removed if possible.
808
809 bool Thread::is_lock_owned(address adr) const {
810 return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
811 }
812
813 bool Thread::set_as_starting_thread() {
814 // NOTE: this must be called inside the main thread.
815 return os::create_main_thread((JavaThread*)this);
816 }
817
818 static void initialize_class(symbolHandle class_name, TRAPS) {
819 klassOop klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
820 instanceKlass::cast(klass)->initialize(CHECK);
821 }
822
823
824 // Creates the initial ThreadGroup
825 static Handle create_initial_thread_group(TRAPS) {
826 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH);
827 instanceKlassHandle klass (THREAD, k);
828
829 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
830 {
831 JavaValue result(T_VOID);
832 JavaCalls::call_special(&result,
833 system_instance,
834 klass,
835 vmSymbolHandles::object_initializer_name(),
836 vmSymbolHandles::void_method_signature(),
837 CHECK_NH);
838 }
839 Universe::set_system_thread_group(system_instance());
840
841 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
842 {
843 JavaValue result(T_VOID);
844 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
845 JavaCalls::call_special(&result,
846 main_instance,
847 klass,
848 vmSymbolHandles::object_initializer_name(),
849 vmSymbolHandles::threadgroup_string_void_signature(),
850 system_instance,
851 string,
852 CHECK_NH);
853 }
854 return main_instance;
855 }
856
857 // Creates the initial Thread
858 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
859 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL);
860 instanceKlassHandle klass (THREAD, k);
861 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
862
863 java_lang_Thread::set_thread(thread_oop(), thread);
864 java_lang_Thread::set_priority(thread_oop(), NormPriority);
865 thread->set_threadObj(thread_oop());
866
867 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
868
869 JavaValue result(T_VOID);
870 JavaCalls::call_special(&result, thread_oop,
871 klass,
872 vmSymbolHandles::object_initializer_name(),
873 vmSymbolHandles::threadgroup_string_void_signature(),
874 thread_group,
875 string,
876 CHECK_NULL);
877 return thread_oop();
878 }
879
880 static void call_initializeSystemClass(TRAPS) {
881 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
882 instanceKlassHandle klass (THREAD, k);
883
884 JavaValue result(T_VOID);
885 JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(),
886 vmSymbolHandles::void_method_signature(), CHECK);
887 }
888
889 #ifdef KERNEL
890 static void set_jkernel_boot_classloader_hook(TRAPS) {
891 klassOop k = SystemDictionary::sun_jkernel_DownloadManager_klass();
892 instanceKlassHandle klass (THREAD, k);
893
894 if (k == NULL) {
895 // sun.jkernel.DownloadManager may not present in the JDK; just return
896 return;
897 }
898
899 JavaValue result(T_VOID);
900 JavaCalls::call_static(&result, klass, vmSymbolHandles::setBootClassLoaderHook_name(),
901 vmSymbolHandles::void_method_signature(), CHECK);
902 }
903 #endif // KERNEL
904
905 static void reset_vm_info_property(TRAPS) {
906 // the vm info string
907 ResourceMark rm(THREAD);
908 const char *vm_info = VM_Version::vm_info_string();
909
910 // java.lang.System class
911 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
912 instanceKlassHandle klass (THREAD, k);
913
914 // setProperty arguments
915 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
916 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
917
918 // return value
919 JavaValue r(T_OBJECT);
920
921 // public static String setProperty(String key, String value);
922 JavaCalls::call_static(&r,
923 klass,
924 vmSymbolHandles::setProperty_name(),
925 vmSymbolHandles::string_string_string_signature(),
926 key_str,
927 value_str,
928 CHECK);
929 }
930
931
932 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
933 assert(thread_group.not_null(), "thread group should be specified");
934 assert(threadObj() == NULL, "should only create Java thread object once");
935
936 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
937 instanceKlassHandle klass (THREAD, k);
938 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
939
940 java_lang_Thread::set_thread(thread_oop(), this);
941 java_lang_Thread::set_priority(thread_oop(), NormPriority);
942 set_threadObj(thread_oop());
943
944 JavaValue result(T_VOID);
945 if (thread_name != NULL) {
946 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
947 // Thread gets assigned specified name and null target
948 JavaCalls::call_special(&result,
949 thread_oop,
950 klass,
951 vmSymbolHandles::object_initializer_name(),
952 vmSymbolHandles::threadgroup_string_void_signature(),
953 thread_group, // Argument 1
954 name, // Argument 2
955 THREAD);
956 } else {
957 // Thread gets assigned name "Thread-nnn" and null target
958 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
959 JavaCalls::call_special(&result,
960 thread_oop,
961 klass,
962 vmSymbolHandles::object_initializer_name(),
963 vmSymbolHandles::threadgroup_runnable_void_signature(),
964 thread_group, // Argument 1
965 Handle(), // Argument 2
966 THREAD);
967 }
968
969
970 if (daemon) {
971 java_lang_Thread::set_daemon(thread_oop());
972 }
973
974 if (HAS_PENDING_EXCEPTION) {
975 return;
976 }
977
978 KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
979 Handle threadObj(this, this->threadObj());
980
981 JavaCalls::call_special(&result,
982 thread_group,
983 group,
984 vmSymbolHandles::add_method_name(),
985 vmSymbolHandles::thread_void_signature(),
986 threadObj, // Arg 1
987 THREAD);
988
989
990 }
991
992 // NamedThread -- non-JavaThread subclasses with multiple
993 // uniquely named instances should derive from this.
994 NamedThread::NamedThread() : Thread() {
995 _name = NULL;
996 _processed_thread = NULL;
997 }
998
999 NamedThread::~NamedThread() {
1000 if (_name != NULL) {
1001 FREE_C_HEAP_ARRAY(char, _name);
1002 _name = NULL;
1003 }
1004 }
1005
1006 void NamedThread::set_name(const char* format, ...) {
1007 guarantee(_name == NULL, "Only get to set name once.");
1008 _name = NEW_C_HEAP_ARRAY(char, max_name_len);
1009 guarantee(_name != NULL, "alloc failure");
1010 va_list ap;
1011 va_start(ap, format);
1012 jio_vsnprintf(_name, max_name_len, format, ap);
1013 va_end(ap);
1014 }
1015
1016 // ======= WatcherThread ========
1017
1018 // The watcher thread exists to simulate timer interrupts. It should
1019 // be replaced by an abstraction over whatever native support for
1020 // timer interrupts exists on the platform.
1021
1022 WatcherThread* WatcherThread::_watcher_thread = NULL;
1023 bool WatcherThread::_should_terminate = false;
1024
1025 WatcherThread::WatcherThread() : Thread() {
1026 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1027 if (os::create_thread(this, os::watcher_thread)) {
1028 _watcher_thread = this;
1029
1030 // Set the watcher thread to the highest OS priority which should not be
1031 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1032 // is created. The only normal thread using this priority is the reference
1033 // handler thread, which runs for very short intervals only.
1034 // If the VMThread's priority is not lower than the WatcherThread profiling
1035 // will be inaccurate.
1036 os::set_priority(this, MaxPriority);
1037 if (!DisableStartThread) {
1038 os::start_thread(this);
1039 }
1040 }
1041 }
1042
1043 void WatcherThread::run() {
1044 assert(this == watcher_thread(), "just checking");
1045
1046 this->record_stack_base_and_size();
1047 this->initialize_thread_local_storage();
1048 this->set_active_handles(JNIHandleBlock::allocate_block());
1049 while(!_should_terminate) {
1050 assert(watcher_thread() == Thread::current(), "thread consistency check");
1051 assert(watcher_thread() == this, "thread consistency check");
1052
1053 // Calculate how long it'll be until the next PeriodicTask work
1054 // should be done, and sleep that amount of time.
1055 const size_t time_to_wait = PeriodicTask::time_to_wait();
1056 os::sleep(this, time_to_wait, false);
1057
1058 if (is_error_reported()) {
1059 // A fatal error has happened, the error handler(VMError::report_and_die)
1060 // should abort JVM after creating an error log file. However in some
1061 // rare cases, the error handler itself might deadlock. Here we try to
1062 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1063 //
1064 // This code is in WatcherThread because WatcherThread wakes up
1065 // periodically so the fatal error handler doesn't need to do anything;
1066 // also because the WatcherThread is less likely to crash than other
1067 // threads.
1068
1069 for (;;) {
1070 if (!ShowMessageBoxOnError
1071 && (OnError == NULL || OnError[0] == '\0')
1072 && Arguments::abort_hook() == NULL) {
1073 os::sleep(this, 2 * 60 * 1000, false);
1074 fdStream err(defaultStream::output_fd());
1075 err.print_raw_cr("# [ timer expired, abort... ]");
1076 // skip atexit/vm_exit/vm_abort hooks
1077 os::die();
1078 }
1079
1080 // Wake up 5 seconds later, the fatal handler may reset OnError or
1081 // ShowMessageBoxOnError when it is ready to abort.
1082 os::sleep(this, 5 * 1000, false);
1083 }
1084 }
1085
1086 PeriodicTask::real_time_tick(time_to_wait);
1087
1088 // If we have no more tasks left due to dynamic disenrollment,
1089 // shut down the thread since we don't currently support dynamic enrollment
1090 if (PeriodicTask::num_tasks() == 0) {
1091 _should_terminate = true;
1092 }
1093 }
1094
1095 // Signal that it is terminated
1096 {
1097 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1098 _watcher_thread = NULL;
1099 Terminator_lock->notify();
1100 }
1101
1102 // Thread destructor usually does this..
1103 ThreadLocalStorage::set_thread(NULL);
1104 }
1105
1106 void WatcherThread::start() {
1107 if (watcher_thread() == NULL) {
1108 _should_terminate = false;
1109 // Create the single instance of WatcherThread
1110 new WatcherThread();
1111 }
1112 }
1113
1114 void WatcherThread::stop() {
1115 // it is ok to take late safepoints here, if needed
1116 MutexLocker mu(Terminator_lock);
1117 _should_terminate = true;
1118 while(watcher_thread() != NULL) {
1119 // This wait should make safepoint checks, wait without a timeout,
1120 // and wait as a suspend-equivalent condition.
1121 //
1122 // Note: If the FlatProfiler is running, then this thread is waiting
1123 // for the WatcherThread to terminate and the WatcherThread, via the
1124 // FlatProfiler task, is waiting for the external suspend request on
1125 // this thread to complete. wait_for_ext_suspend_completion() will
1126 // eventually timeout, but that takes time. Making this wait a
1127 // suspend-equivalent condition solves that timeout problem.
1128 //
1129 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1130 Mutex::_as_suspend_equivalent_flag);
1131 }
1132 }
1133
1134 void WatcherThread::print_on(outputStream* st) const {
1135 st->print("\"%s\" ", name());
1136 Thread::print_on(st);
1137 st->cr();
1138 }
1139
1140 // ======= JavaThread ========
1141
1142 // A JavaThread is a normal Java thread
1143
1144 void JavaThread::initialize() {
1145 // Initialize fields
1146
1147 // Set the claimed par_id to -1 (ie not claiming any par_ids)
1148 set_claimed_par_id(-1);
1149
1150 set_saved_exception_pc(NULL);
1151 set_threadObj(NULL);
1152 _anchor.clear();
1153 set_entry_point(NULL);
1154 set_jni_functions(jni_functions());
1155 set_callee_target(NULL);
1156 set_vm_result(NULL);
1157 set_vm_result_2(NULL);
1158 set_vframe_array_head(NULL);
1159 set_vframe_array_last(NULL);
1160 set_deferred_locals(NULL);
1161 set_deopt_mark(NULL);
1162 clear_must_deopt_id();
1163 set_monitor_chunks(NULL);
1164 set_next(NULL);
1165 set_thread_state(_thread_new);
1166 _terminated = _not_terminated;
1167 _privileged_stack_top = NULL;
1168 _array_for_gc = NULL;
1169 _suspend_equivalent = false;
1170 _in_deopt_handler = 0;
1171 _doing_unsafe_access = false;
1172 _stack_guard_state = stack_guard_unused;
1173 _exception_oop = NULL;
1174 _exception_pc = 0;
1175 _exception_handler_pc = 0;
1176 _exception_stack_size = 0;
1177 _jvmti_thread_state= NULL;
1178 _should_post_on_exceptions_flag = JNI_FALSE;
1179 _jvmti_get_loaded_classes_closure = NULL;
1180 _interp_only_mode = 0;
1181 _special_runtime_exit_condition = _no_async_condition;
1182 _pending_async_exception = NULL;
1183 _is_compiling = false;
1184 _thread_stat = NULL;
1185 _thread_stat = new ThreadStatistics();
1186 _blocked_on_compilation = false;
1187 _jni_active_critical = 0;
1188 _do_not_unlock_if_synchronized = false;
1189 _cached_monitor_info = NULL;
1190 _parker = Parker::Allocate(this) ;
1191
1192 #ifndef PRODUCT
1193 _jmp_ring_index = 0;
1194 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1195 record_jump(NULL, NULL, NULL, 0);
1196 }
1197 #endif /* PRODUCT */
1198
1199 set_thread_profiler(NULL);
1200 if (FlatProfiler::is_active()) {
1201 // This is where we would decide to either give each thread it's own profiler
1202 // or use one global one from FlatProfiler,
1203 // or up to some count of the number of profiled threads, etc.
1204 ThreadProfiler* pp = new ThreadProfiler();
1205 pp->engage();
1206 set_thread_profiler(pp);
1207 }
1208
1209 // Setup safepoint state info for this thread
1210 ThreadSafepointState::create(this);
1211
1212 debug_only(_java_call_counter = 0);
1213
1214 // JVMTI PopFrame support
1215 _popframe_condition = popframe_inactive;
1216 _popframe_preserved_args = NULL;
1217 _popframe_preserved_args_size = 0;
1218
1219 pd_initialize();
1220 }
1221
1222 #ifndef SERIALGC
1223 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1224 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1225 #endif // !SERIALGC
1226
1227 JavaThread::JavaThread(bool is_attaching) :
1228 Thread()
1229 #ifndef SERIALGC
1230 , _satb_mark_queue(&_satb_mark_queue_set),
1231 _dirty_card_queue(&_dirty_card_queue_set)
1232 #endif // !SERIALGC
1233 {
1234 initialize();
1235 _is_attaching = is_attaching;
1236 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor");
1237 }
1238
1239 bool JavaThread::reguard_stack(address cur_sp) {
1240 if (_stack_guard_state != stack_guard_yellow_disabled) {
1241 return true; // Stack already guarded or guard pages not needed.
1242 }
1243
1244 if (register_stack_overflow()) {
1245 // For those architectures which have separate register and
1246 // memory stacks, we must check the register stack to see if
1247 // it has overflowed.
1248 return false;
1249 }
1250
1251 // Java code never executes within the yellow zone: the latter is only
1252 // there to provoke an exception during stack banging. If java code
1253 // is executing there, either StackShadowPages should be larger, or
1254 // some exception code in c1, c2 or the interpreter isn't unwinding
1255 // when it should.
1256 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1257
1258 enable_stack_yellow_zone();
1259 return true;
1260 }
1261
1262 bool JavaThread::reguard_stack(void) {
1263 return reguard_stack(os::current_stack_pointer());
1264 }
1265
1266
1267 void JavaThread::block_if_vm_exited() {
1268 if (_terminated == _vm_exited) {
1269 // _vm_exited is set at safepoint, and Threads_lock is never released
1270 // we will block here forever
1271 Threads_lock->lock_without_safepoint_check();
1272 ShouldNotReachHere();
1273 }
1274 }
1275
1276
1277 // Remove this ifdef when C1 is ported to the compiler interface.
1278 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1279
1280 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1281 Thread()
1282 #ifndef SERIALGC
1283 , _satb_mark_queue(&_satb_mark_queue_set),
1284 _dirty_card_queue(&_dirty_card_queue_set)
1285 #endif // !SERIALGC
1286 {
1287 if (TraceThreadEvents) {
1288 tty->print_cr("creating thread %p", this);
1289 }
1290 initialize();
1291 _is_attaching = false;
1292 set_entry_point(entry_point);
1293 // Create the native thread itself.
1294 // %note runtime_23
1295 os::ThreadType thr_type = os::java_thread;
1296 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1297 os::java_thread;
1298 os::create_thread(this, thr_type, stack_sz);
1299
1300 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1301 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1302 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1303 // the exception consists of creating the exception object & initializing it, initialization
1304 // will leave the VM via a JavaCall and then all locks must be unlocked).
1305 //
1306 // The thread is still suspended when we reach here. Thread must be explicit started
1307 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1308 // by calling Threads:add. The reason why this is not done here, is because the thread
1309 // object must be fully initialized (take a look at JVM_Start)
1310 }
1311
1312 JavaThread::~JavaThread() {
1313 if (TraceThreadEvents) {
1314 tty->print_cr("terminate thread %p", this);
1315 }
1316
1317 // JSR166 -- return the parker to the free list
1318 Parker::Release(_parker);
1319 _parker = NULL ;
1320
1321 // Free any remaining previous UnrollBlock
1322 vframeArray* old_array = vframe_array_last();
1323
1324 if (old_array != NULL) {
1325 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1326 old_array->set_unroll_block(NULL);
1327 delete old_info;
1328 delete old_array;
1329 }
1330
1331 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1332 if (deferred != NULL) {
1333 // This can only happen if thread is destroyed before deoptimization occurs.
1334 assert(deferred->length() != 0, "empty array!");
1335 do {
1336 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1337 deferred->remove_at(0);
1338 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1339 delete dlv;
1340 } while (deferred->length() != 0);
1341 delete deferred;
1342 }
1343
1344 // All Java related clean up happens in exit
1345 ThreadSafepointState::destroy(this);
1346 if (_thread_profiler != NULL) delete _thread_profiler;
1347 if (_thread_stat != NULL) delete _thread_stat;
1348 }
1349
1350
1351 // The first routine called by a new Java thread
1352 void JavaThread::run() {
1353 // initialize thread-local alloc buffer related fields
1354 this->initialize_tlab();
1355
1356 // used to test validitity of stack trace backs
1357 this->record_base_of_stack_pointer();
1358
1359 // Record real stack base and size.
1360 this->record_stack_base_and_size();
1361
1362 // Initialize thread local storage; set before calling MutexLocker
1363 this->initialize_thread_local_storage();
1364
1365 this->create_stack_guard_pages();
1366
1367 // Thread is now sufficient initialized to be handled by the safepoint code as being
1368 // in the VM. Change thread state from _thread_new to _thread_in_vm
1369 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1370
1371 assert(JavaThread::current() == this, "sanity check");
1372 assert(!Thread::current()->owns_locks(), "sanity check");
1373
1374 DTRACE_THREAD_PROBE(start, this);
1375
1376 // This operation might block. We call that after all safepoint checks for a new thread has
1377 // been completed.
1378 this->set_active_handles(JNIHandleBlock::allocate_block());
1379
1380 if (JvmtiExport::should_post_thread_life()) {
1381 JvmtiExport::post_thread_start(this);
1382 }
1383
1384 // We call another function to do the rest so we are sure that the stack addresses used
1385 // from there will be lower than the stack base just computed
1386 thread_main_inner();
1387
1388 // Note, thread is no longer valid at this point!
1389 }
1390
1391
1392 void JavaThread::thread_main_inner() {
1393 assert(JavaThread::current() == this, "sanity check");
1394 assert(this->threadObj() != NULL, "just checking");
1395
1396 // Execute thread entry point. If this thread is being asked to restart,
1397 // or has been stopped before starting, do not reexecute entry point.
1398 // Note: Due to JVM_StopThread we can have pending exceptions already!
1399 if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) {
1400 // enter the thread's entry point only if we have no pending exceptions
1401 HandleMark hm(this);
1402 this->entry_point()(this, this);
1403 }
1404
1405 DTRACE_THREAD_PROBE(stop, this);
1406
1407 this->exit(false);
1408 delete this;
1409 }
1410
1411
1412 static void ensure_join(JavaThread* thread) {
1413 // We do not need to grap the Threads_lock, since we are operating on ourself.
1414 Handle threadObj(thread, thread->threadObj());
1415 assert(threadObj.not_null(), "java thread object must exist");
1416 ObjectLocker lock(threadObj, thread);
1417 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1418 thread->clear_pending_exception();
1419 // It is of profound importance that we set the stillborn bit and reset the thread object,
1420 // before we do the notify. Since, changing these two variable will make JVM_IsAlive return
1421 // false. So in case another thread is doing a join on this thread , it will detect that the thread
1422 // is dead when it gets notified.
1423 java_lang_Thread::set_stillborn(threadObj());
1424 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1425 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1426 java_lang_Thread::set_thread(threadObj(), NULL);
1427 lock.notify_all(thread);
1428 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1429 thread->clear_pending_exception();
1430 }
1431
1432
1433 // For any new cleanup additions, please check to see if they need to be applied to
1434 // cleanup_failed_attach_current_thread as well.
1435 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1436 assert(this == JavaThread::current(), "thread consistency check");
1437 if (!InitializeJavaLangSystem) return;
1438
1439 HandleMark hm(this);
1440 Handle uncaught_exception(this, this->pending_exception());
1441 this->clear_pending_exception();
1442 Handle threadObj(this, this->threadObj());
1443 assert(threadObj.not_null(), "Java thread object should be created");
1444
1445 if (get_thread_profiler() != NULL) {
1446 get_thread_profiler()->disengage();
1447 ResourceMark rm;
1448 get_thread_profiler()->print(get_thread_name());
1449 }
1450
1451
1452 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1453 {
1454 EXCEPTION_MARK;
1455
1456 CLEAR_PENDING_EXCEPTION;
1457 }
1458 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1459 // has to be fixed by a runtime query method
1460 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1461 // JSR-166: change call from from ThreadGroup.uncaughtException to
1462 // java.lang.Thread.dispatchUncaughtException
1463 if (uncaught_exception.not_null()) {
1464 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1465 Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT",
1466 (address)uncaught_exception(), (address)threadObj(), (address)group());
1467 {
1468 EXCEPTION_MARK;
1469 // Check if the method Thread.dispatchUncaughtException() exists. If so
1470 // call it. Otherwise we have an older library without the JSR-166 changes,
1471 // so call ThreadGroup.uncaughtException()
1472 KlassHandle recvrKlass(THREAD, threadObj->klass());
1473 CallInfo callinfo;
1474 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1475 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1476 vmSymbolHandles::dispatchUncaughtException_name(),
1477 vmSymbolHandles::throwable_void_signature(),
1478 KlassHandle(), false, false, THREAD);
1479 CLEAR_PENDING_EXCEPTION;
1480 methodHandle method = callinfo.selected_method();
1481 if (method.not_null()) {
1482 JavaValue result(T_VOID);
1483 JavaCalls::call_virtual(&result,
1484 threadObj, thread_klass,
1485 vmSymbolHandles::dispatchUncaughtException_name(),
1486 vmSymbolHandles::throwable_void_signature(),
1487 uncaught_exception,
1488 THREAD);
1489 } else {
1490 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1491 JavaValue result(T_VOID);
1492 JavaCalls::call_virtual(&result,
1493 group, thread_group,
1494 vmSymbolHandles::uncaughtException_name(),
1495 vmSymbolHandles::thread_throwable_void_signature(),
1496 threadObj, // Arg 1
1497 uncaught_exception, // Arg 2
1498 THREAD);
1499 }
1500 CLEAR_PENDING_EXCEPTION;
1501 }
1502 }
1503
1504 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1505 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1506 // is deprecated anyhow.
1507 { int count = 3;
1508 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1509 EXCEPTION_MARK;
1510 JavaValue result(T_VOID);
1511 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1512 JavaCalls::call_virtual(&result,
1513 threadObj, thread_klass,
1514 vmSymbolHandles::exit_method_name(),
1515 vmSymbolHandles::void_method_signature(),
1516 THREAD);
1517 CLEAR_PENDING_EXCEPTION;
1518 }
1519 }
1520
1521 // notify JVMTI
1522 if (JvmtiExport::should_post_thread_life()) {
1523 JvmtiExport::post_thread_end(this);
1524 }
1525
1526 // We have notified the agents that we are exiting, before we go on,
1527 // we must check for a pending external suspend request and honor it
1528 // in order to not surprise the thread that made the suspend request.
1529 while (true) {
1530 {
1531 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1532 if (!is_external_suspend()) {
1533 set_terminated(_thread_exiting);
1534 ThreadService::current_thread_exiting(this);
1535 break;
1536 }
1537 // Implied else:
1538 // Things get a little tricky here. We have a pending external
1539 // suspend request, but we are holding the SR_lock so we
1540 // can't just self-suspend. So we temporarily drop the lock
1541 // and then self-suspend.
1542 }
1543
1544 ThreadBlockInVM tbivm(this);
1545 java_suspend_self();
1546
1547 // We're done with this suspend request, but we have to loop around
1548 // and check again. Eventually we will get SR_lock without a pending
1549 // external suspend request and will be able to mark ourselves as
1550 // exiting.
1551 }
1552 // no more external suspends are allowed at this point
1553 } else {
1554 // before_exit() has already posted JVMTI THREAD_END events
1555 }
1556
1557 // Notify waiters on thread object. This has to be done after exit() is called
1558 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1559 // group should have the destroyed bit set before waiters are notified).
1560 ensure_join(this);
1561 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1562
1563 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1564 // held by this thread must be released. A detach operation must only
1565 // get here if there are no Java frames on the stack. Therefore, any
1566 // owned monitors at this point MUST be JNI-acquired monitors which are
1567 // pre-inflated and in the monitor cache.
1568 //
1569 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1570 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1571 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1572 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1573 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1574 }
1575
1576 // These things needs to be done while we are still a Java Thread. Make sure that thread
1577 // is in a consistent state, in case GC happens
1578 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1579
1580 if (active_handles() != NULL) {
1581 JNIHandleBlock* block = active_handles();
1582 set_active_handles(NULL);
1583 JNIHandleBlock::release_block(block);
1584 }
1585
1586 if (free_handle_block() != NULL) {
1587 JNIHandleBlock* block = free_handle_block();
1588 set_free_handle_block(NULL);
1589 JNIHandleBlock::release_block(block);
1590 }
1591
1592 // These have to be removed while this is still a valid thread.
1593 remove_stack_guard_pages();
1594
1595 if (UseTLAB) {
1596 tlab().make_parsable(true); // retire TLAB
1597 }
1598
1599 if (jvmti_thread_state() != NULL) {
1600 JvmtiExport::cleanup_thread(this);
1601 }
1602
1603 #ifndef SERIALGC
1604 // We must flush G1-related buffers before removing a thread from
1605 // the list of active threads.
1606 if (UseG1GC) {
1607 flush_barrier_queues();
1608 }
1609 #endif
1610
1611 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1612 Threads::remove(this);
1613 }
1614
1615 #ifndef SERIALGC
1616 // Flush G1-related queues.
1617 void JavaThread::flush_barrier_queues() {
1618 satb_mark_queue().flush();
1619 dirty_card_queue().flush();
1620 }
1621 #endif
1622
1623 void JavaThread::cleanup_failed_attach_current_thread() {
1624 if (get_thread_profiler() != NULL) {
1625 get_thread_profiler()->disengage();
1626 ResourceMark rm;
1627 get_thread_profiler()->print(get_thread_name());
1628 }
1629
1630 if (active_handles() != NULL) {
1631 JNIHandleBlock* block = active_handles();
1632 set_active_handles(NULL);
1633 JNIHandleBlock::release_block(block);
1634 }
1635
1636 if (free_handle_block() != NULL) {
1637 JNIHandleBlock* block = free_handle_block();
1638 set_free_handle_block(NULL);
1639 JNIHandleBlock::release_block(block);
1640 }
1641
1642 // These have to be removed while this is still a valid thread.
1643 remove_stack_guard_pages();
1644
1645 if (UseTLAB) {
1646 tlab().make_parsable(true); // retire TLAB, if any
1647 }
1648
1649 #ifndef SERIALGC
1650 if (UseG1GC) {
1651 flush_barrier_queues();
1652 }
1653 #endif
1654
1655 Threads::remove(this);
1656 delete this;
1657 }
1658
1659
1660
1661
1662 JavaThread* JavaThread::active() {
1663 Thread* thread = ThreadLocalStorage::thread();
1664 assert(thread != NULL, "just checking");
1665 if (thread->is_Java_thread()) {
1666 return (JavaThread*) thread;
1667 } else {
1668 assert(thread->is_VM_thread(), "this must be a vm thread");
1669 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1670 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1671 assert(ret->is_Java_thread(), "must be a Java thread");
1672 return ret;
1673 }
1674 }
1675
1676 bool JavaThread::is_lock_owned(address adr) const {
1677 if (Thread::is_lock_owned(adr)) return true;
1678
1679 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1680 if (chunk->contains(adr)) return true;
1681 }
1682
1683 return false;
1684 }
1685
1686
1687 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1688 chunk->set_next(monitor_chunks());
1689 set_monitor_chunks(chunk);
1690 }
1691
1692 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1693 guarantee(monitor_chunks() != NULL, "must be non empty");
1694 if (monitor_chunks() == chunk) {
1695 set_monitor_chunks(chunk->next());
1696 } else {
1697 MonitorChunk* prev = monitor_chunks();
1698 while (prev->next() != chunk) prev = prev->next();
1699 prev->set_next(chunk->next());
1700 }
1701 }
1702
1703 // JVM support.
1704
1705 // Note: this function shouldn't block if it's called in
1706 // _thread_in_native_trans state (such as from
1707 // check_special_condition_for_native_trans()).
1708 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
1709
1710 if (has_last_Java_frame() && has_async_condition()) {
1711 // If we are at a polling page safepoint (not a poll return)
1712 // then we must defer async exception because live registers
1713 // will be clobbered by the exception path. Poll return is
1714 // ok because the call we a returning from already collides
1715 // with exception handling registers and so there is no issue.
1716 // (The exception handling path kills call result registers but
1717 // this is ok since the exception kills the result anyway).
1718
1719 if (is_at_poll_safepoint()) {
1720 // if the code we are returning to has deoptimized we must defer
1721 // the exception otherwise live registers get clobbered on the
1722 // exception path before deoptimization is able to retrieve them.
1723 //
1724 RegisterMap map(this, false);
1725 frame caller_fr = last_frame().sender(&map);
1726 assert(caller_fr.is_compiled_frame(), "what?");
1727 if (caller_fr.is_deoptimized_frame()) {
1728 if (TraceExceptions) {
1729 ResourceMark rm;
1730 tty->print_cr("deferred async exception at compiled safepoint");
1731 }
1732 return;
1733 }
1734 }
1735 }
1736
1737 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
1738 if (condition == _no_async_condition) {
1739 // Conditions have changed since has_special_runtime_exit_condition()
1740 // was called:
1741 // - if we were here only because of an external suspend request,
1742 // then that was taken care of above (or cancelled) so we are done
1743 // - if we were here because of another async request, then it has
1744 // been cleared between the has_special_runtime_exit_condition()
1745 // and now so again we are done
1746 return;
1747 }
1748
1749 // Check for pending async. exception
1750 if (_pending_async_exception != NULL) {
1751 // Only overwrite an already pending exception, if it is not a threadDeath.
1752 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
1753
1754 // We cannot call Exceptions::_throw(...) here because we cannot block
1755 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1756
1757 if (TraceExceptions) {
1758 ResourceMark rm;
1759 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
1760 if (has_last_Java_frame() ) {
1761 frame f = last_frame();
1762 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
1763 }
1764 tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1765 }
1766 _pending_async_exception = NULL;
1767 clear_has_async_exception();
1768 }
1769 }
1770
1771 if (check_unsafe_error &&
1772 condition == _async_unsafe_access_error && !has_pending_exception()) {
1773 condition = _no_async_condition; // done
1774 switch (thread_state()) {
1775 case _thread_in_vm:
1776 {
1777 JavaThread* THREAD = this;
1778 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1779 }
1780 case _thread_in_native:
1781 {
1782 ThreadInVMfromNative tiv(this);
1783 JavaThread* THREAD = this;
1784 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1785 }
1786 case _thread_in_Java:
1787 {
1788 ThreadInVMfromJava tiv(this);
1789 JavaThread* THREAD = this;
1790 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1791 }
1792 default:
1793 ShouldNotReachHere();
1794 }
1795 }
1796
1797 assert(condition == _no_async_condition || has_pending_exception() ||
1798 (!check_unsafe_error && condition == _async_unsafe_access_error),
1799 "must have handled the async condition, if no exception");
1800 }
1801
1802 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1803 //
1804 // Check for pending external suspend. Internal suspend requests do
1805 // not use handle_special_runtime_exit_condition().
1806 // If JNIEnv proxies are allowed, don't self-suspend if the target
1807 // thread is not the current thread. In older versions of jdbx, jdbx
1808 // threads could call into the VM with another thread's JNIEnv so we
1809 // can be here operating on behalf of a suspended thread (4432884).
1810 bool do_self_suspend = is_external_suspend_with_lock();
1811 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
1812 //
1813 // Because thread is external suspended the safepoint code will count
1814 // thread as at a safepoint. This can be odd because we can be here
1815 // as _thread_in_Java which would normally transition to _thread_blocked
1816 // at a safepoint. We would like to mark the thread as _thread_blocked
1817 // before calling java_suspend_self like all other callers of it but
1818 // we must then observe proper safepoint protocol. (We can't leave
1819 // _thread_blocked with a safepoint in progress). However we can be
1820 // here as _thread_in_native_trans so we can't use a normal transition
1821 // constructor/destructor pair because they assert on that type of
1822 // transition. We could do something like:
1823 //
1824 // JavaThreadState state = thread_state();
1825 // set_thread_state(_thread_in_vm);
1826 // {
1827 // ThreadBlockInVM tbivm(this);
1828 // java_suspend_self()
1829 // }
1830 // set_thread_state(_thread_in_vm_trans);
1831 // if (safepoint) block;
1832 // set_thread_state(state);
1833 //
1834 // but that is pretty messy. Instead we just go with the way the
1835 // code has worked before and note that this is the only path to
1836 // java_suspend_self that doesn't put the thread in _thread_blocked
1837 // mode.
1838
1839 frame_anchor()->make_walkable(this);
1840 java_suspend_self();
1841
1842 // We might be here for reasons in addition to the self-suspend request
1843 // so check for other async requests.
1844 }
1845
1846 if (check_asyncs) {
1847 check_and_handle_async_exceptions();
1848 }
1849 }
1850
1851 void JavaThread::send_thread_stop(oop java_throwable) {
1852 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
1853 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
1854 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1855
1856 // Do not throw asynchronous exceptions against the compiler thread
1857 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1858 if (is_Compiler_thread()) return;
1859
1860 // This is a change from JDK 1.1, but JDK 1.2 will also do it:
1861 if (java_throwable->is_a(SystemDictionary::ThreadDeath_klass())) {
1862 java_lang_Thread::set_stillborn(threadObj());
1863 }
1864
1865 {
1866 // Actually throw the Throwable against the target Thread - however
1867 // only if there is no thread death exception installed already.
1868 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
1869 // If the topmost frame is a runtime stub, then we are calling into
1870 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1871 // must deoptimize the caller before continuing, as the compiled exception handler table
1872 // may not be valid
1873 if (has_last_Java_frame()) {
1874 frame f = last_frame();
1875 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1876 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
1877 RegisterMap reg_map(this, UseBiasedLocking);
1878 frame compiled_frame = f.sender(®_map);
1879 if (compiled_frame.can_be_deoptimized()) {
1880 Deoptimization::deoptimize(this, compiled_frame, ®_map);
1881 }
1882 }
1883 }
1884
1885 // Set async. pending exception in thread.
1886 set_pending_async_exception(java_throwable);
1887
1888 if (TraceExceptions) {
1889 ResourceMark rm;
1890 tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
1891 }
1892 // for AbortVMOnException flag
1893 NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name()));
1894 }
1895 }
1896
1897
1898 // Interrupt thread so it will wake up from a potential wait()
1899 Thread::interrupt(this);
1900 }
1901
1902 // External suspension mechanism.
1903 //
1904 // Tell the VM to suspend a thread when ever it knows that it does not hold on
1905 // to any VM_locks and it is at a transition
1906 // Self-suspension will happen on the transition out of the vm.
1907 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
1908 //
1909 // Guarantees on return:
1910 // + Target thread will not execute any new bytecode (that's why we need to
1911 // force a safepoint)
1912 // + Target thread will not enter any new monitors
1913 //
1914 void JavaThread::java_suspend() {
1915 { MutexLocker mu(Threads_lock);
1916 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
1917 return;
1918 }
1919 }
1920
1921 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1922 if (!is_external_suspend()) {
1923 // a racing resume has cancelled us; bail out now
1924 return;
1925 }
1926
1927 // suspend is done
1928 uint32_t debug_bits = 0;
1929 // Warning: is_ext_suspend_completed() may temporarily drop the
1930 // SR_lock to allow the thread to reach a stable thread state if
1931 // it is currently in a transient thread state.
1932 if (is_ext_suspend_completed(false /* !called_by_wait */,
1933 SuspendRetryDelay, &debug_bits) ) {
1934 return;
1935 }
1936 }
1937
1938 VM_ForceSafepoint vm_suspend;
1939 VMThread::execute(&vm_suspend);
1940 }
1941
1942 // Part II of external suspension.
1943 // A JavaThread self suspends when it detects a pending external suspend
1944 // request. This is usually on transitions. It is also done in places
1945 // where continuing to the next transition would surprise the caller,
1946 // e.g., monitor entry.
1947 //
1948 // Returns the number of times that the thread self-suspended.
1949 //
1950 // Note: DO NOT call java_suspend_self() when you just want to block current
1951 // thread. java_suspend_self() is the second stage of cooperative
1952 // suspension for external suspend requests and should only be used
1953 // to complete an external suspend request.
1954 //
1955 int JavaThread::java_suspend_self() {
1956 int ret = 0;
1957
1958 // we are in the process of exiting so don't suspend
1959 if (is_exiting()) {
1960 clear_external_suspend();
1961 return ret;
1962 }
1963
1964 assert(_anchor.walkable() ||
1965 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
1966 "must have walkable stack");
1967
1968 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1969
1970 assert(!this->is_ext_suspended(),
1971 "a thread trying to self-suspend should not already be suspended");
1972
1973 if (this->is_suspend_equivalent()) {
1974 // If we are self-suspending as a result of the lifting of a
1975 // suspend equivalent condition, then the suspend_equivalent
1976 // flag is not cleared until we set the ext_suspended flag so
1977 // that wait_for_ext_suspend_completion() returns consistent
1978 // results.
1979 this->clear_suspend_equivalent();
1980 }
1981
1982 // A racing resume may have cancelled us before we grabbed SR_lock
1983 // above. Or another external suspend request could be waiting for us
1984 // by the time we return from SR_lock()->wait(). The thread
1985 // that requested the suspension may already be trying to walk our
1986 // stack and if we return now, we can change the stack out from under
1987 // it. This would be a "bad thing (TM)" and cause the stack walker
1988 // to crash. We stay self-suspended until there are no more pending
1989 // external suspend requests.
1990 while (is_external_suspend()) {
1991 ret++;
1992 this->set_ext_suspended();
1993
1994 // _ext_suspended flag is cleared by java_resume()
1995 while (is_ext_suspended()) {
1996 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
1997 }
1998 }
1999
2000 return ret;
2001 }
2002
2003 #ifdef ASSERT
2004 // verify the JavaThread has not yet been published in the Threads::list, and
2005 // hence doesn't need protection from concurrent access at this stage
2006 void JavaThread::verify_not_published() {
2007 if (!Threads_lock->owned_by_self()) {
2008 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2009 assert( !Threads::includes(this),
2010 "java thread shouldn't have been published yet!");
2011 }
2012 else {
2013 assert( !Threads::includes(this),
2014 "java thread shouldn't have been published yet!");
2015 }
2016 }
2017 #endif
2018
2019 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2020 // progress or when _suspend_flags is non-zero.
2021 // Current thread needs to self-suspend if there is a suspend request and/or
2022 // block if a safepoint is in progress.
2023 // Async exception ISN'T checked.
2024 // Note only the ThreadInVMfromNative transition can call this function
2025 // directly and when thread state is _thread_in_native_trans
2026 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2027 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2028
2029 JavaThread *curJT = JavaThread::current();
2030 bool do_self_suspend = thread->is_external_suspend();
2031
2032 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2033
2034 // If JNIEnv proxies are allowed, don't self-suspend if the target
2035 // thread is not the current thread. In older versions of jdbx, jdbx
2036 // threads could call into the VM with another thread's JNIEnv so we
2037 // can be here operating on behalf of a suspended thread (4432884).
2038 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2039 JavaThreadState state = thread->thread_state();
2040
2041 // We mark this thread_blocked state as a suspend-equivalent so
2042 // that a caller to is_ext_suspend_completed() won't be confused.
2043 // The suspend-equivalent state is cleared by java_suspend_self().
2044 thread->set_suspend_equivalent();
2045
2046 // If the safepoint code sees the _thread_in_native_trans state, it will
2047 // wait until the thread changes to other thread state. There is no
2048 // guarantee on how soon we can obtain the SR_lock and complete the
2049 // self-suspend request. It would be a bad idea to let safepoint wait for
2050 // too long. Temporarily change the state to _thread_blocked to
2051 // let the VM thread know that this thread is ready for GC. The problem
2052 // of changing thread state is that safepoint could happen just after
2053 // java_suspend_self() returns after being resumed, and VM thread will
2054 // see the _thread_blocked state. We must check for safepoint
2055 // after restoring the state and make sure we won't leave while a safepoint
2056 // is in progress.
2057 thread->set_thread_state(_thread_blocked);
2058 thread->java_suspend_self();
2059 thread->set_thread_state(state);
2060 // Make sure new state is seen by VM thread
2061 if (os::is_MP()) {
2062 if (UseMembar) {
2063 // Force a fence between the write above and read below
2064 OrderAccess::fence();
2065 } else {
2066 // Must use this rather than serialization page in particular on Windows
2067 InterfaceSupport::serialize_memory(thread);
2068 }
2069 }
2070 }
2071
2072 if (SafepointSynchronize::do_call_back()) {
2073 // If we are safepointing, then block the caller which may not be
2074 // the same as the target thread (see above).
2075 SafepointSynchronize::block(curJT);
2076 }
2077
2078 if (thread->is_deopt_suspend()) {
2079 thread->clear_deopt_suspend();
2080 RegisterMap map(thread, false);
2081 frame f = thread->last_frame();
2082 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2083 f = f.sender(&map);
2084 }
2085 if (f.id() == thread->must_deopt_id()) {
2086 thread->clear_must_deopt_id();
2087 // Since we know we're safe to deopt the current state is a safe state
2088 f.deoptimize(thread, true);
2089 } else {
2090 fatal("missed deoptimization!");
2091 }
2092 }
2093 }
2094
2095 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2096 // progress or when _suspend_flags is non-zero.
2097 // Current thread needs to self-suspend if there is a suspend request and/or
2098 // block if a safepoint is in progress.
2099 // Also check for pending async exception (not including unsafe access error).
2100 // Note only the native==>VM/Java barriers can call this function and when
2101 // thread state is _thread_in_native_trans.
2102 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2103 check_safepoint_and_suspend_for_native_trans(thread);
2104
2105 if (thread->has_async_exception()) {
2106 // We are in _thread_in_native_trans state, don't handle unsafe
2107 // access error since that may block.
2108 thread->check_and_handle_async_exceptions(false);
2109 }
2110 }
2111
2112 // We need to guarantee the Threads_lock here, since resumes are not
2113 // allowed during safepoint synchronization
2114 // Can only resume from an external suspension
2115 void JavaThread::java_resume() {
2116 assert_locked_or_safepoint(Threads_lock);
2117
2118 // Sanity check: thread is gone, has started exiting or the thread
2119 // was not externally suspended.
2120 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2121 return;
2122 }
2123
2124 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2125
2126 clear_external_suspend();
2127
2128 if (is_ext_suspended()) {
2129 clear_ext_suspended();
2130 SR_lock()->notify_all();
2131 }
2132 }
2133
2134 void JavaThread::create_stack_guard_pages() {
2135 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2136 address low_addr = stack_base() - stack_size();
2137 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2138
2139 int allocate = os::allocate_stack_guard_pages();
2140 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2141
2142 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
2143 warning("Attempt to allocate stack guard pages failed.");
2144 return;
2145 }
2146
2147 if (os::guard_memory((char *) low_addr, len)) {
2148 _stack_guard_state = stack_guard_enabled;
2149 } else {
2150 warning("Attempt to protect stack guard pages failed.");
2151 if (os::uncommit_memory((char *) low_addr, len)) {
2152 warning("Attempt to deallocate stack guard pages failed.");
2153 }
2154 }
2155 }
2156
2157 void JavaThread::remove_stack_guard_pages() {
2158 if (_stack_guard_state == stack_guard_unused) return;
2159 address low_addr = stack_base() - stack_size();
2160 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2161
2162 if (os::allocate_stack_guard_pages()) {
2163 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2164 _stack_guard_state = stack_guard_unused;
2165 } else {
2166 warning("Attempt to deallocate stack guard pages failed.");
2167 }
2168 } else {
2169 if (_stack_guard_state == stack_guard_unused) return;
2170 if (os::unguard_memory((char *) low_addr, len)) {
2171 _stack_guard_state = stack_guard_unused;
2172 } else {
2173 warning("Attempt to unprotect stack guard pages failed.");
2174 }
2175 }
2176 }
2177
2178 void JavaThread::enable_stack_yellow_zone() {
2179 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2180 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2181
2182 // The base notation is from the stacks point of view, growing downward.
2183 // We need to adjust it to work correctly with guard_memory()
2184 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2185
2186 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2187 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2188
2189 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2190 _stack_guard_state = stack_guard_enabled;
2191 } else {
2192 warning("Attempt to guard stack yellow zone failed.");
2193 }
2194 enable_register_stack_guard();
2195 }
2196
2197 void JavaThread::disable_stack_yellow_zone() {
2198 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2199 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2200
2201 // Simply return if called for a thread that does not use guard pages.
2202 if (_stack_guard_state == stack_guard_unused) return;
2203
2204 // The base notation is from the stacks point of view, growing downward.
2205 // We need to adjust it to work correctly with guard_memory()
2206 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2207
2208 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2209 _stack_guard_state = stack_guard_yellow_disabled;
2210 } else {
2211 warning("Attempt to unguard stack yellow zone failed.");
2212 }
2213 disable_register_stack_guard();
2214 }
2215
2216 void JavaThread::enable_stack_red_zone() {
2217 // The base notation is from the stacks point of view, growing downward.
2218 // We need to adjust it to work correctly with guard_memory()
2219 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2220 address base = stack_red_zone_base() - stack_red_zone_size();
2221
2222 guarantee(base < stack_base(),"Error calculating stack red zone");
2223 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2224
2225 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2226 warning("Attempt to guard stack red zone failed.");
2227 }
2228 }
2229
2230 void JavaThread::disable_stack_red_zone() {
2231 // The base notation is from the stacks point of view, growing downward.
2232 // We need to adjust it to work correctly with guard_memory()
2233 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2234 address base = stack_red_zone_base() - stack_red_zone_size();
2235 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2236 warning("Attempt to unguard stack red zone failed.");
2237 }
2238 }
2239
2240 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2241 // ignore is there is no stack
2242 if (!has_last_Java_frame()) return;
2243 // traverse the stack frames. Starts from top frame.
2244 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2245 frame* fr = fst.current();
2246 f(fr, fst.register_map());
2247 }
2248 }
2249
2250
2251 #ifndef PRODUCT
2252 // Deoptimization
2253 // Function for testing deoptimization
2254 void JavaThread::deoptimize() {
2255 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2256 StackFrameStream fst(this, UseBiasedLocking);
2257 bool deopt = false; // Dump stack only if a deopt actually happens.
2258 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2259 // Iterate over all frames in the thread and deoptimize
2260 for(; !fst.is_done(); fst.next()) {
2261 if(fst.current()->can_be_deoptimized()) {
2262
2263 if (only_at) {
2264 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2265 // consists of comma or carriage return separated numbers so
2266 // search for the current bci in that string.
2267 address pc = fst.current()->pc();
2268 nmethod* nm = (nmethod*) fst.current()->cb();
2269 ScopeDesc* sd = nm->scope_desc_at( pc);
2270 char buffer[8];
2271 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2272 size_t len = strlen(buffer);
2273 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2274 while (found != NULL) {
2275 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2276 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2277 // Check that the bci found is bracketed by terminators.
2278 break;
2279 }
2280 found = strstr(found + 1, buffer);
2281 }
2282 if (!found) {
2283 continue;
2284 }
2285 }
2286
2287 if (DebugDeoptimization && !deopt) {
2288 deopt = true; // One-time only print before deopt
2289 tty->print_cr("[BEFORE Deoptimization]");
2290 trace_frames();
2291 trace_stack();
2292 }
2293 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2294 }
2295 }
2296
2297 if (DebugDeoptimization && deopt) {
2298 tty->print_cr("[AFTER Deoptimization]");
2299 trace_frames();
2300 }
2301 }
2302
2303
2304 // Make zombies
2305 void JavaThread::make_zombies() {
2306 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2307 if (fst.current()->can_be_deoptimized()) {
2308 // it is a Java nmethod
2309 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2310 nm->make_not_entrant();
2311 }
2312 }
2313 }
2314 #endif // PRODUCT
2315
2316
2317 void JavaThread::deoptimized_wrt_marked_nmethods() {
2318 if (!has_last_Java_frame()) return;
2319 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2320 StackFrameStream fst(this, UseBiasedLocking);
2321 for(; !fst.is_done(); fst.next()) {
2322 if (fst.current()->should_be_deoptimized()) {
2323 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2324 }
2325 }
2326 }
2327
2328
2329 // GC support
2330 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2331
2332 void JavaThread::gc_epilogue() {
2333 frames_do(frame_gc_epilogue);
2334 }
2335
2336
2337 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2338
2339 void JavaThread::gc_prologue() {
2340 frames_do(frame_gc_prologue);
2341 }
2342
2343 // If the caller is a NamedThread, then remember, in the current scope,
2344 // the given JavaThread in its _processed_thread field.
2345 class RememberProcessedThread: public StackObj {
2346 NamedThread* _cur_thr;
2347 public:
2348 RememberProcessedThread(JavaThread* jthr) {
2349 Thread* thread = Thread::current();
2350 if (thread->is_Named_thread()) {
2351 _cur_thr = (NamedThread *)thread;
2352 _cur_thr->set_processed_thread(jthr);
2353 } else {
2354 _cur_thr = NULL;
2355 }
2356 }
2357
2358 ~RememberProcessedThread() {
2359 if (_cur_thr) {
2360 _cur_thr->set_processed_thread(NULL);
2361 }
2362 }
2363 };
2364
2365 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2366 // Verify that the deferred card marks have been flushed.
2367 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2368
2369 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2370 // since there may be more than one thread using each ThreadProfiler.
2371
2372 // Traverse the GCHandles
2373 Thread::oops_do(f, cf);
2374
2375 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2376 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2377
2378 if (has_last_Java_frame()) {
2379 // Record JavaThread to GC thread
2380 RememberProcessedThread rpt(this);
2381
2382 // Traverse the privileged stack
2383 if (_privileged_stack_top != NULL) {
2384 _privileged_stack_top->oops_do(f);
2385 }
2386
2387 // traverse the registered growable array
2388 if (_array_for_gc != NULL) {
2389 for (int index = 0; index < _array_for_gc->length(); index++) {
2390 f->do_oop(_array_for_gc->adr_at(index));
2391 }
2392 }
2393
2394 // Traverse the monitor chunks
2395 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2396 chunk->oops_do(f);
2397 }
2398
2399 // Traverse the execution stack
2400 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2401 fst.current()->oops_do(f, cf, fst.register_map());
2402 }
2403 }
2404
2405 // callee_target is never live across a gc point so NULL it here should
2406 // it still contain a methdOop.
2407
2408 set_callee_target(NULL);
2409
2410 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2411 // If we have deferred set_locals there might be oops waiting to be
2412 // written
2413 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2414 if (list != NULL) {
2415 for (int i = 0; i < list->length(); i++) {
2416 list->at(i)->oops_do(f);
2417 }
2418 }
2419
2420 // Traverse instance variables at the end since the GC may be moving things
2421 // around using this function
2422 f->do_oop((oop*) &_threadObj);
2423 f->do_oop((oop*) &_vm_result);
2424 f->do_oop((oop*) &_vm_result_2);
2425 f->do_oop((oop*) &_exception_oop);
2426 f->do_oop((oop*) &_pending_async_exception);
2427
2428 if (jvmti_thread_state() != NULL) {
2429 jvmti_thread_state()->oops_do(f);
2430 }
2431 }
2432
2433 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2434 Thread::nmethods_do(cf); // (super method is a no-op)
2435
2436 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2437 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2438
2439 if (has_last_Java_frame()) {
2440 // Traverse the execution stack
2441 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2442 fst.current()->nmethods_do(cf);
2443 }
2444 }
2445 }
2446
2447 // Printing
2448 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2449 switch (_thread_state) {
2450 case _thread_uninitialized: return "_thread_uninitialized";
2451 case _thread_new: return "_thread_new";
2452 case _thread_new_trans: return "_thread_new_trans";
2453 case _thread_in_native: return "_thread_in_native";
2454 case _thread_in_native_trans: return "_thread_in_native_trans";
2455 case _thread_in_vm: return "_thread_in_vm";
2456 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2457 case _thread_in_Java: return "_thread_in_Java";
2458 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2459 case _thread_blocked: return "_thread_blocked";
2460 case _thread_blocked_trans: return "_thread_blocked_trans";
2461 default: return "unknown thread state";
2462 }
2463 }
2464
2465 #ifndef PRODUCT
2466 void JavaThread::print_thread_state_on(outputStream *st) const {
2467 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2468 };
2469 void JavaThread::print_thread_state() const {
2470 print_thread_state_on(tty);
2471 };
2472 #endif // PRODUCT
2473
2474 // Called by Threads::print() for VM_PrintThreads operation
2475 void JavaThread::print_on(outputStream *st) const {
2476 st->print("\"%s\" ", get_thread_name());
2477 oop thread_oop = threadObj();
2478 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2479 Thread::print_on(st);
2480 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2481 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2482 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2483 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2484 }
2485 #ifndef PRODUCT
2486 print_thread_state_on(st);
2487 _safepoint_state->print_on(st);
2488 #endif // PRODUCT
2489 }
2490
2491 // Called by fatal error handler. The difference between this and
2492 // JavaThread::print() is that we can't grab lock or allocate memory.
2493 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2494 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2495 oop thread_obj = threadObj();
2496 if (thread_obj != NULL) {
2497 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2498 }
2499 st->print(" [");
2500 st->print("%s", _get_thread_state_name(_thread_state));
2501 if (osthread()) {
2502 st->print(", id=%d", osthread()->thread_id());
2503 }
2504 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2505 _stack_base - _stack_size, _stack_base);
2506 st->print("]");
2507 return;
2508 }
2509
2510 // Verification
2511
2512 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2513
2514 void JavaThread::verify() {
2515 // Verify oops in the thread.
2516 oops_do(&VerifyOopClosure::verify_oop, NULL);
2517
2518 // Verify the stack frames.
2519 frames_do(frame_verify);
2520 }
2521
2522 // CR 6300358 (sub-CR 2137150)
2523 // Most callers of this method assume that it can't return NULL but a
2524 // thread may not have a name whilst it is in the process of attaching to
2525 // the VM - see CR 6412693, and there are places where a JavaThread can be
2526 // seen prior to having it's threadObj set (eg JNI attaching threads and
2527 // if vm exit occurs during initialization). These cases can all be accounted
2528 // for such that this method never returns NULL.
2529 const char* JavaThread::get_thread_name() const {
2530 #ifdef ASSERT
2531 // early safepoints can hit while current thread does not yet have TLS
2532 if (!SafepointSynchronize::is_at_safepoint()) {
2533 Thread *cur = Thread::current();
2534 if (!(cur->is_Java_thread() && cur == this)) {
2535 // Current JavaThreads are allowed to get their own name without
2536 // the Threads_lock.
2537 assert_locked_or_safepoint(Threads_lock);
2538 }
2539 }
2540 #endif // ASSERT
2541 return get_thread_name_string();
2542 }
2543
2544 // Returns a non-NULL representation of this thread's name, or a suitable
2545 // descriptive string if there is no set name
2546 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2547 const char* name_str;
2548 oop thread_obj = threadObj();
2549 if (thread_obj != NULL) {
2550 typeArrayOop name = java_lang_Thread::name(thread_obj);
2551 if (name != NULL) {
2552 if (buf == NULL) {
2553 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2554 }
2555 else {
2556 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2557 }
2558 }
2559 else if (is_attaching()) { // workaround for 6412693 - see 6404306
2560 name_str = "<no-name - thread is attaching>";
2561 }
2562 else {
2563 name_str = Thread::name();
2564 }
2565 }
2566 else {
2567 name_str = Thread::name();
2568 }
2569 assert(name_str != NULL, "unexpected NULL thread name");
2570 return name_str;
2571 }
2572
2573
2574 const char* JavaThread::get_threadgroup_name() const {
2575 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2576 oop thread_obj = threadObj();
2577 if (thread_obj != NULL) {
2578 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2579 if (thread_group != NULL) {
2580 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2581 // ThreadGroup.name can be null
2582 if (name != NULL) {
2583 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2584 return str;
2585 }
2586 }
2587 }
2588 return NULL;
2589 }
2590
2591 const char* JavaThread::get_parent_name() const {
2592 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2593 oop thread_obj = threadObj();
2594 if (thread_obj != NULL) {
2595 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2596 if (thread_group != NULL) {
2597 oop parent = java_lang_ThreadGroup::parent(thread_group);
2598 if (parent != NULL) {
2599 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2600 // ThreadGroup.name can be null
2601 if (name != NULL) {
2602 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2603 return str;
2604 }
2605 }
2606 }
2607 }
2608 return NULL;
2609 }
2610
2611 ThreadPriority JavaThread::java_priority() const {
2612 oop thr_oop = threadObj();
2613 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2614 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2615 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2616 return priority;
2617 }
2618
2619 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2620
2621 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2622 // Link Java Thread object <-> C++ Thread
2623
2624 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2625 // and put it into a new Handle. The Handle "thread_oop" can then
2626 // be used to pass the C++ thread object to other methods.
2627
2628 // Set the Java level thread object (jthread) field of the
2629 // new thread (a JavaThread *) to C++ thread object using the
2630 // "thread_oop" handle.
2631
2632 // Set the thread field (a JavaThread *) of the
2633 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2634
2635 Handle thread_oop(Thread::current(),
2636 JNIHandles::resolve_non_null(jni_thread));
2637 assert(instanceKlass::cast(thread_oop->klass())->is_linked(),
2638 "must be initialized");
2639 set_threadObj(thread_oop());
2640 java_lang_Thread::set_thread(thread_oop(), this);
2641
2642 if (prio == NoPriority) {
2643 prio = java_lang_Thread::priority(thread_oop());
2644 assert(prio != NoPriority, "A valid priority should be present");
2645 }
2646
2647 // Push the Java priority down to the native thread; needs Threads_lock
2648 Thread::set_priority(this, prio);
2649
2650 // Add the new thread to the Threads list and set it in motion.
2651 // We must have threads lock in order to call Threads::add.
2652 // It is crucial that we do not block before the thread is
2653 // added to the Threads list for if a GC happens, then the java_thread oop
2654 // will not be visited by GC.
2655 Threads::add(this);
2656 }
2657
2658 oop JavaThread::current_park_blocker() {
2659 // Support for JSR-166 locks
2660 oop thread_oop = threadObj();
2661 if (thread_oop != NULL &&
2662 JDK_Version::current().supports_thread_park_blocker()) {
2663 return java_lang_Thread::park_blocker(thread_oop);
2664 }
2665 return NULL;
2666 }
2667
2668
2669 void JavaThread::print_stack_on(outputStream* st) {
2670 if (!has_last_Java_frame()) return;
2671 ResourceMark rm;
2672 HandleMark hm;
2673
2674 RegisterMap reg_map(this);
2675 vframe* start_vf = last_java_vframe(®_map);
2676 int count = 0;
2677 for (vframe* f = start_vf; f; f = f->sender() ) {
2678 if (f->is_java_frame()) {
2679 javaVFrame* jvf = javaVFrame::cast(f);
2680 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2681
2682 // Print out lock information
2683 if (JavaMonitorsInStackTrace) {
2684 jvf->print_lock_info_on(st, count);
2685 }
2686 } else {
2687 // Ignore non-Java frames
2688 }
2689
2690 // Bail-out case for too deep stacks
2691 count++;
2692 if (MaxJavaStackTraceDepth == count) return;
2693 }
2694 }
2695
2696
2697 // JVMTI PopFrame support
2698 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2699 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2700 if (in_bytes(size_in_bytes) != 0) {
2701 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes));
2702 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2703 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2704 }
2705 }
2706
2707 void* JavaThread::popframe_preserved_args() {
2708 return _popframe_preserved_args;
2709 }
2710
2711 ByteSize JavaThread::popframe_preserved_args_size() {
2712 return in_ByteSize(_popframe_preserved_args_size);
2713 }
2714
2715 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2716 int sz = in_bytes(popframe_preserved_args_size());
2717 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2718 return in_WordSize(sz / wordSize);
2719 }
2720
2721 void JavaThread::popframe_free_preserved_args() {
2722 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2723 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args);
2724 _popframe_preserved_args = NULL;
2725 _popframe_preserved_args_size = 0;
2726 }
2727
2728 #ifndef PRODUCT
2729
2730 void JavaThread::trace_frames() {
2731 tty->print_cr("[Describe stack]");
2732 int frame_no = 1;
2733 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2734 tty->print(" %d. ", frame_no++);
2735 fst.current()->print_value_on(tty,this);
2736 tty->cr();
2737 }
2738 }
2739
2740
2741 void JavaThread::trace_stack_from(vframe* start_vf) {
2742 ResourceMark rm;
2743 int vframe_no = 1;
2744 for (vframe* f = start_vf; f; f = f->sender() ) {
2745 if (f->is_java_frame()) {
2746 javaVFrame::cast(f)->print_activation(vframe_no++);
2747 } else {
2748 f->print();
2749 }
2750 if (vframe_no > StackPrintLimit) {
2751 tty->print_cr("...<more frames>...");
2752 return;
2753 }
2754 }
2755 }
2756
2757
2758 void JavaThread::trace_stack() {
2759 if (!has_last_Java_frame()) return;
2760 ResourceMark rm;
2761 HandleMark hm;
2762 RegisterMap reg_map(this);
2763 trace_stack_from(last_java_vframe(®_map));
2764 }
2765
2766
2767 #endif // PRODUCT
2768
2769
2770 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2771 assert(reg_map != NULL, "a map must be given");
2772 frame f = last_frame();
2773 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
2774 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2775 }
2776 return NULL;
2777 }
2778
2779
2780 klassOop JavaThread::security_get_caller_class(int depth) {
2781 vframeStream vfst(this);
2782 vfst.security_get_caller_frame(depth);
2783 if (!vfst.at_end()) {
2784 return vfst.method()->method_holder();
2785 }
2786 return NULL;
2787 }
2788
2789 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
2790 assert(thread->is_Compiler_thread(), "must be compiler thread");
2791 CompileBroker::compiler_thread_loop();
2792 }
2793
2794 // Create a CompilerThread
2795 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
2796 : JavaThread(&compiler_thread_entry) {
2797 _env = NULL;
2798 _log = NULL;
2799 _task = NULL;
2800 _queue = queue;
2801 _counters = counters;
2802 _buffer_blob = NULL;
2803
2804 #ifndef PRODUCT
2805 _ideal_graph_printer = NULL;
2806 #endif
2807 }
2808
2809
2810 // ======= Threads ========
2811
2812 // The Threads class links together all active threads, and provides
2813 // operations over all threads. It is protected by its own Mutex
2814 // lock, which is also used in other contexts to protect thread
2815 // operations from having the thread being operated on from exiting
2816 // and going away unexpectedly (e.g., safepoint synchronization)
2817
2818 JavaThread* Threads::_thread_list = NULL;
2819 int Threads::_number_of_threads = 0;
2820 int Threads::_number_of_non_daemon_threads = 0;
2821 int Threads::_return_code = 0;
2822 size_t JavaThread::_stack_size_at_create = 0;
2823
2824 // All JavaThreads
2825 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
2826
2827 void os_stream();
2828
2829 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
2830 void Threads::threads_do(ThreadClosure* tc) {
2831 assert_locked_or_safepoint(Threads_lock);
2832 // ALL_JAVA_THREADS iterates through all JavaThreads
2833 ALL_JAVA_THREADS(p) {
2834 tc->do_thread(p);
2835 }
2836 // Someday we could have a table or list of all non-JavaThreads.
2837 // For now, just manually iterate through them.
2838 tc->do_thread(VMThread::vm_thread());
2839 Universe::heap()->gc_threads_do(tc);
2840 WatcherThread *wt = WatcherThread::watcher_thread();
2841 // Strictly speaking, the following NULL check isn't sufficient to make sure
2842 // the data for WatcherThread is still valid upon being examined. However,
2843 // considering that WatchThread terminates when the VM is on the way to
2844 // exit at safepoint, the chance of the above is extremely small. The right
2845 // way to prevent termination of WatcherThread would be to acquire
2846 // Terminator_lock, but we can't do that without violating the lock rank
2847 // checking in some cases.
2848 if (wt != NULL)
2849 tc->do_thread(wt);
2850
2851 // If CompilerThreads ever become non-JavaThreads, add them here
2852 }
2853
2854 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2855
2856 extern void JDK_Version_init();
2857
2858 // Check version
2859 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2860
2861 // Initialize the output stream module
2862 ostream_init();
2863
2864 // Process java launcher properties.
2865 Arguments::process_sun_java_launcher_properties(args);
2866
2867 // Initialize the os module before using TLS
2868 os::init();
2869
2870 // Initialize system properties.
2871 Arguments::init_system_properties();
2872
2873 // So that JDK version can be used as a discrimintor when parsing arguments
2874 JDK_Version_init();
2875
2876 // Parse arguments
2877 jint parse_result = Arguments::parse(args);
2878 if (parse_result != JNI_OK) return parse_result;
2879
2880 if (PauseAtStartup) {
2881 os::pause();
2882 }
2883
2884 HS_DTRACE_PROBE(hotspot, vm__init__begin);
2885
2886 // Record VM creation timing statistics
2887 TraceVmCreationTime create_vm_timer;
2888 create_vm_timer.start();
2889
2890 // Timing (must come after argument parsing)
2891 TraceTime timer("Create VM", TraceStartupTime);
2892
2893 // Initialize the os module after parsing the args
2894 jint os_init_2_result = os::init_2();
2895 if (os_init_2_result != JNI_OK) return os_init_2_result;
2896
2897 // Initialize output stream logging
2898 ostream_init_log();
2899
2900 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2901 // Must be before create_vm_init_agents()
2902 if (Arguments::init_libraries_at_startup()) {
2903 convert_vm_init_libraries_to_agents();
2904 }
2905
2906 // Launch -agentlib/-agentpath and converted -Xrun agents
2907 if (Arguments::init_agents_at_startup()) {
2908 create_vm_init_agents();
2909 }
2910
2911 // Initialize Threads state
2912 _thread_list = NULL;
2913 _number_of_threads = 0;
2914 _number_of_non_daemon_threads = 0;
2915
2916 // Initialize TLS
2917 ThreadLocalStorage::init();
2918
2919 // Initialize global data structures and create system classes in heap
2920 vm_init_globals();
2921
2922 // Attach the main thread to this os thread
2923 JavaThread* main_thread = new JavaThread();
2924 main_thread->set_thread_state(_thread_in_vm);
2925 // must do this before set_active_handles and initialize_thread_local_storage
2926 // Note: on solaris initialize_thread_local_storage() will (indirectly)
2927 // change the stack size recorded here to one based on the java thread
2928 // stacksize. This adjusted size is what is used to figure the placement
2929 // of the guard pages.
2930 main_thread->record_stack_base_and_size();
2931 main_thread->initialize_thread_local_storage();
2932
2933 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2934
2935 if (!main_thread->set_as_starting_thread()) {
2936 vm_shutdown_during_initialization(
2937 "Failed necessary internal allocation. Out of swap space");
2938 delete main_thread;
2939 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2940 return JNI_ENOMEM;
2941 }
2942
2943 // Enable guard page *after* os::create_main_thread(), otherwise it would
2944 // crash Linux VM, see notes in os_linux.cpp.
2945 main_thread->create_stack_guard_pages();
2946
2947 // Initialize Java-Leve synchronization subsystem
2948 ObjectSynchronizer::Initialize() ;
2949
2950 // Initialize global modules
2951 jint status = init_globals();
2952 if (status != JNI_OK) {
2953 delete main_thread;
2954 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2955 return status;
2956 }
2957
2958 HandleMark hm;
2959
2960 { MutexLocker mu(Threads_lock);
2961 Threads::add(main_thread);
2962 }
2963
2964 // Any JVMTI raw monitors entered in onload will transition into
2965 // real raw monitor. VM is setup enough here for raw monitor enter.
2966 JvmtiExport::transition_pending_onload_raw_monitors();
2967
2968 if (VerifyBeforeGC &&
2969 Universe::heap()->total_collections() >= VerifyGCStartAt) {
2970 Universe::heap()->prepare_for_verify();
2971 Universe::verify(); // make sure we're starting with a clean slate
2972 }
2973
2974 // Create the VMThread
2975 { TraceTime timer("Start VMThread", TraceStartupTime);
2976 VMThread::create();
2977 Thread* vmthread = VMThread::vm_thread();
2978
2979 if (!os::create_thread(vmthread, os::vm_thread))
2980 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
2981
2982 // Wait for the VM thread to become ready, and VMThread::run to initialize
2983 // Monitors can have spurious returns, must always check another state flag
2984 {
2985 MutexLocker ml(Notify_lock);
2986 os::start_thread(vmthread);
2987 while (vmthread->active_handles() == NULL) {
2988 Notify_lock->wait();
2989 }
2990 }
2991 }
2992
2993 assert (Universe::is_fully_initialized(), "not initialized");
2994 EXCEPTION_MARK;
2995
2996 // At this point, the Universe is initialized, but we have not executed
2997 // any byte code. Now is a good time (the only time) to dump out the
2998 // internal state of the JVM for sharing.
2999
3000 if (DumpSharedSpaces) {
3001 Universe::heap()->preload_and_dump(CHECK_0);
3002 ShouldNotReachHere();
3003 }
3004
3005 // Always call even when there are not JVMTI environments yet, since environments
3006 // may be attached late and JVMTI must track phases of VM execution
3007 JvmtiExport::enter_start_phase();
3008
3009 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3010 JvmtiExport::post_vm_start();
3011
3012 {
3013 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3014
3015 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3016 create_vm_init_libraries();
3017 }
3018
3019 if (InitializeJavaLangString) {
3020 initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0);
3021 } else {
3022 warning("java.lang.String not initialized");
3023 }
3024
3025 if (AggressiveOpts) {
3026 {
3027 // Forcibly initialize java/util/HashMap and mutate the private
3028 // static final "frontCacheEnabled" field before we start creating instances
3029 #ifdef ASSERT
3030 klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3031 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
3032 #endif
3033 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3034 KlassHandle k = KlassHandle(THREAD, k_o);
3035 guarantee(k.not_null(), "Must find java/util/HashMap");
3036 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3037 ik->initialize(CHECK_0);
3038 fieldDescriptor fd;
3039 // Possible we might not find this field; if so, don't break
3040 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3041 k()->bool_field_put(fd.offset(), true);
3042 }
3043 }
3044
3045 if (UseStringCache) {
3046 // Forcibly initialize java/lang/StringValue and mutate the private
3047 // static final "stringCacheEnabled" field before we start creating instances
3048 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3049 // Possible that StringValue isn't present: if so, silently don't break
3050 if (k_o != NULL) {
3051 KlassHandle k = KlassHandle(THREAD, k_o);
3052 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3053 ik->initialize(CHECK_0);
3054 fieldDescriptor fd;
3055 // Possible we might not find this field: if so, silently don't break
3056 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3057 k()->bool_field_put(fd.offset(), true);
3058 }
3059 }
3060 }
3061 }
3062
3063 // Initialize java_lang.System (needed before creating the thread)
3064 if (InitializeJavaLangSystem) {
3065 initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0);
3066 initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0);
3067 Handle thread_group = create_initial_thread_group(CHECK_0);
3068 Universe::set_main_thread_group(thread_group());
3069 initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0);
3070 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3071 main_thread->set_threadObj(thread_object);
3072 // Set thread status to running since main thread has
3073 // been started and running.
3074 java_lang_Thread::set_thread_status(thread_object,
3075 java_lang_Thread::RUNNABLE);
3076
3077 // The VM preresolve methods to these classes. Make sure that get initialized
3078 initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0);
3079 initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0);
3080 // The VM creates & returns objects of this class. Make sure it's initialized.
3081 initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0);
3082 call_initializeSystemClass(CHECK_0);
3083 } else {
3084 warning("java.lang.System not initialized");
3085 }
3086
3087 // an instance of OutOfMemory exception has been allocated earlier
3088 if (InitializeJavaLangExceptionsErrors) {
3089 initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0);
3090 initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0);
3091 initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0);
3092 initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0);
3093 initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0);
3094 initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0);
3095 initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0);
3096 } else {
3097 warning("java.lang.OutOfMemoryError has not been initialized");
3098 warning("java.lang.NullPointerException has not been initialized");
3099 warning("java.lang.ClassCastException has not been initialized");
3100 warning("java.lang.ArrayStoreException has not been initialized");
3101 warning("java.lang.ArithmeticException has not been initialized");
3102 warning("java.lang.StackOverflowError has not been initialized");
3103 }
3104
3105 if (EnableInvokeDynamic) {
3106 // JSR 292: An intialized java.dyn.InvokeDynamic is required in
3107 // the compiler.
3108 initialize_class(vmSymbolHandles::java_dyn_InvokeDynamic(), CHECK_0);
3109 }
3110 }
3111
3112 // See : bugid 4211085.
3113 // Background : the static initializer of java.lang.Compiler tries to read
3114 // property"java.compiler" and read & write property "java.vm.info".
3115 // When a security manager is installed through the command line
3116 // option "-Djava.security.manager", the above properties are not
3117 // readable and the static initializer for java.lang.Compiler fails
3118 // resulting in a NoClassDefFoundError. This can happen in any
3119 // user code which calls methods in java.lang.Compiler.
3120 // Hack : the hack is to pre-load and initialize this class, so that only
3121 // system domains are on the stack when the properties are read.
3122 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3123 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3124 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3125 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3126 // Once that is done, we should remove this hack.
3127 initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0);
3128
3129 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3130 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3131 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3132 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3133 // This should also be taken out as soon as 4211383 gets fixed.
3134 reset_vm_info_property(CHECK_0);
3135
3136 quicken_jni_functions();
3137
3138 // Set flag that basic initialization has completed. Used by exceptions and various
3139 // debug stuff, that does not work until all basic classes have been initialized.
3140 set_init_completed();
3141
3142 HS_DTRACE_PROBE(hotspot, vm__init__end);
3143
3144 // record VM initialization completion time
3145 Management::record_vm_init_completed();
3146
3147 // Compute system loader. Note that this has to occur after set_init_completed, since
3148 // valid exceptions may be thrown in the process.
3149 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3150 // set_init_completed has just been called, causing exceptions not to be shortcut
3151 // anymore. We call vm_exit_during_initialization directly instead.
3152 SystemDictionary::compute_java_system_loader(THREAD);
3153 if (HAS_PENDING_EXCEPTION) {
3154 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3155 }
3156
3157 #ifdef KERNEL
3158 if (JDK_Version::is_gte_jdk17x_version()) {
3159 set_jkernel_boot_classloader_hook(THREAD);
3160 }
3161 #endif // KERNEL
3162
3163 #ifndef SERIALGC
3164 // Support for ConcurrentMarkSweep. This should be cleaned up
3165 // and better encapsulated. The ugly nested if test would go away
3166 // once things are properly refactored. XXX YSR
3167 if (UseConcMarkSweepGC || UseG1GC) {
3168 if (UseConcMarkSweepGC) {
3169 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3170 } else {
3171 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3172 }
3173 if (HAS_PENDING_EXCEPTION) {
3174 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3175 }
3176 }
3177 #endif // SERIALGC
3178
3179 // Always call even when there are not JVMTI environments yet, since environments
3180 // may be attached late and JVMTI must track phases of VM execution
3181 JvmtiExport::enter_live_phase();
3182
3183 // Signal Dispatcher needs to be started before VMInit event is posted
3184 os::signal_init();
3185
3186 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3187 if (!DisableAttachMechanism) {
3188 if (StartAttachListener || AttachListener::init_at_startup()) {
3189 AttachListener::init();
3190 }
3191 }
3192
3193 // Launch -Xrun agents
3194 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3195 // back-end can launch with -Xdebug -Xrunjdwp.
3196 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3197 create_vm_init_libraries();
3198 }
3199
3200 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3201 JvmtiExport::post_vm_initialized();
3202
3203 Chunk::start_chunk_pool_cleaner_task();
3204
3205 // initialize compiler(s)
3206 CompileBroker::compilation_init();
3207
3208 Management::initialize(THREAD);
3209 if (HAS_PENDING_EXCEPTION) {
3210 // management agent fails to start possibly due to
3211 // configuration problem and is responsible for printing
3212 // stack trace if appropriate. Simply exit VM.
3213 vm_exit(1);
3214 }
3215
3216 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3217 if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
3218 if (MemProfiling) MemProfiler::engage();
3219 StatSampler::engage();
3220 if (CheckJNICalls) JniPeriodicChecker::engage();
3221
3222 BiasedLocking::init();
3223
3224
3225 // Start up the WatcherThread if there are any periodic tasks
3226 // NOTE: All PeriodicTasks should be registered by now. If they
3227 // aren't, late joiners might appear to start slowly (we might
3228 // take a while to process their first tick).
3229 if (PeriodicTask::num_tasks() > 0) {
3230 WatcherThread::start();
3231 }
3232
3233 create_vm_timer.end();
3234 return JNI_OK;
3235 }
3236
3237 // type for the Agent_OnLoad and JVM_OnLoad entry points
3238 extern "C" {
3239 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3240 }
3241 // Find a command line agent library and return its entry point for
3242 // -agentlib: -agentpath: -Xrun
3243 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3244 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3245 OnLoadEntry_t on_load_entry = NULL;
3246 void *library = agent->os_lib(); // check if we have looked it up before
3247
3248 if (library == NULL) {
3249 char buffer[JVM_MAXPATHLEN];
3250 char ebuf[1024];
3251 const char *name = agent->name();
3252
3253 if (agent->is_absolute_path()) {
3254 library = hpi::dll_load(name, ebuf, sizeof ebuf);
3255 if (library == NULL) {
3256 // If we can't find the agent, exit.
3257 vm_exit_during_initialization("Could not find agent library in absolute path", name);
3258 }
3259 } else {
3260 // Try to load the agent from the standard dll directory
3261 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name);
3262 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3263 #ifdef KERNEL
3264 // Download instrument dll
3265 if (library == NULL && strcmp(name, "instrument") == 0) {
3266 char *props = Arguments::get_kernel_properties();
3267 char *home = Arguments::get_java_home();
3268 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false"
3269 " sun.jkernel.DownloadManager -download client_jvm";
3270 int length = strlen(props) + strlen(home) + strlen(fmt) + 1;
3271 char *cmd = AllocateHeap(length);
3272 jio_snprintf(cmd, length, fmt, home, props);
3273 int status = os::fork_and_exec(cmd);
3274 FreeHeap(props);
3275 FreeHeap(cmd);
3276 if (status == -1) {
3277 warning(cmd);
3278 vm_exit_during_initialization("fork_and_exec failed: %s",
3279 strerror(errno));
3280 }
3281 // when this comes back the instrument.dll should be where it belongs.
3282 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3283 }
3284 #endif // KERNEL
3285 if (library == NULL) { // Try the local directory
3286 char ns[1] = {0};
3287 hpi::dll_build_name(buffer, sizeof(buffer), ns, name);
3288 library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
3289 if (library == NULL) {
3290 // If we can't find the agent, exit.
3291 vm_exit_during_initialization("Could not find agent library on the library path or in the local directory", name);
3292 }
3293 }
3294 }
3295 agent->set_os_lib(library);
3296 }
3297
3298 // Find the OnLoad function.
3299 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
3300 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index]));
3301 if (on_load_entry != NULL) break;
3302 }
3303 return on_load_entry;
3304 }
3305
3306 // Find the JVM_OnLoad entry point
3307 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3308 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3309 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3310 }
3311
3312 // Find the Agent_OnLoad entry point
3313 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3314 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3315 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3316 }
3317
3318 // For backwards compatibility with -Xrun
3319 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3320 // treated like -agentpath:
3321 // Must be called before agent libraries are created
3322 void Threads::convert_vm_init_libraries_to_agents() {
3323 AgentLibrary* agent;
3324 AgentLibrary* next;
3325
3326 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3327 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3328 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3329
3330 // If there is an JVM_OnLoad function it will get called later,
3331 // otherwise see if there is an Agent_OnLoad
3332 if (on_load_entry == NULL) {
3333 on_load_entry = lookup_agent_on_load(agent);
3334 if (on_load_entry != NULL) {
3335 // switch it to the agent list -- so that Agent_OnLoad will be called,
3336 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3337 Arguments::convert_library_to_agent(agent);
3338 } else {
3339 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3340 }
3341 }
3342 }
3343 }
3344
3345 // Create agents for -agentlib: -agentpath: and converted -Xrun
3346 // Invokes Agent_OnLoad
3347 // Called very early -- before JavaThreads exist
3348 void Threads::create_vm_init_agents() {
3349 extern struct JavaVM_ main_vm;
3350 AgentLibrary* agent;
3351
3352 JvmtiExport::enter_onload_phase();
3353 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3354 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3355
3356 if (on_load_entry != NULL) {
3357 // Invoke the Agent_OnLoad function
3358 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3359 if (err != JNI_OK) {
3360 vm_exit_during_initialization("agent library failed to init", agent->name());
3361 }
3362 } else {
3363 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3364 }
3365 }
3366 JvmtiExport::enter_primordial_phase();
3367 }
3368
3369 extern "C" {
3370 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3371 }
3372
3373 void Threads::shutdown_vm_agents() {
3374 // Send any Agent_OnUnload notifications
3375 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3376 extern struct JavaVM_ main_vm;
3377 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3378
3379 // Find the Agent_OnUnload function.
3380 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
3381 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3382 hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
3383
3384 // Invoke the Agent_OnUnload function
3385 if (unload_entry != NULL) {
3386 JavaThread* thread = JavaThread::current();
3387 ThreadToNativeFromVM ttn(thread);
3388 HandleMark hm(thread);
3389 (*unload_entry)(&main_vm);
3390 break;
3391 }
3392 }
3393 }
3394 }
3395
3396 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3397 // Invokes JVM_OnLoad
3398 void Threads::create_vm_init_libraries() {
3399 extern struct JavaVM_ main_vm;
3400 AgentLibrary* agent;
3401
3402 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3403 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3404
3405 if (on_load_entry != NULL) {
3406 // Invoke the JVM_OnLoad function
3407 JavaThread* thread = JavaThread::current();
3408 ThreadToNativeFromVM ttn(thread);
3409 HandleMark hm(thread);
3410 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3411 if (err != JNI_OK) {
3412 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3413 }
3414 } else {
3415 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3416 }
3417 }
3418 }
3419
3420 // Last thread running calls java.lang.Shutdown.shutdown()
3421 void JavaThread::invoke_shutdown_hooks() {
3422 HandleMark hm(this);
3423
3424 // We could get here with a pending exception, if so clear it now.
3425 if (this->has_pending_exception()) {
3426 this->clear_pending_exception();
3427 }
3428
3429 EXCEPTION_MARK;
3430 klassOop k =
3431 SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(),
3432 THREAD);
3433 if (k != NULL) {
3434 // SystemDictionary::resolve_or_null will return null if there was
3435 // an exception. If we cannot load the Shutdown class, just don't
3436 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3437 // and finalizers (if runFinalizersOnExit is set) won't be run.
3438 // Note that if a shutdown hook was registered or runFinalizersOnExit
3439 // was called, the Shutdown class would have already been loaded
3440 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3441 instanceKlassHandle shutdown_klass (THREAD, k);
3442 JavaValue result(T_VOID);
3443 JavaCalls::call_static(&result,
3444 shutdown_klass,
3445 vmSymbolHandles::shutdown_method_name(),
3446 vmSymbolHandles::void_method_signature(),
3447 THREAD);
3448 }
3449 CLEAR_PENDING_EXCEPTION;
3450 }
3451
3452 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3453 // the program falls off the end of main(). Another VM exit path is through
3454 // vm_exit() when the program calls System.exit() to return a value or when
3455 // there is a serious error in VM. The two shutdown paths are not exactly
3456 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3457 // and VM_Exit op at VM level.
3458 //
3459 // Shutdown sequence:
3460 // + Wait until we are the last non-daemon thread to execute
3461 // <-- every thing is still working at this moment -->
3462 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3463 // shutdown hooks, run finalizers if finalization-on-exit
3464 // + Call before_exit(), prepare for VM exit
3465 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3466 // currently the only user of this mechanism is File.deleteOnExit())
3467 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3468 // post thread end and vm death events to JVMTI,
3469 // stop signal thread
3470 // + Call JavaThread::exit(), it will:
3471 // > release JNI handle blocks, remove stack guard pages
3472 // > remove this thread from Threads list
3473 // <-- no more Java code from this thread after this point -->
3474 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3475 // the compiler threads at safepoint
3476 // <-- do not use anything that could get blocked by Safepoint -->
3477 // + Disable tracing at JNI/JVM barriers
3478 // + Set _vm_exited flag for threads that are still running native code
3479 // + Delete this thread
3480 // + Call exit_globals()
3481 // > deletes tty
3482 // > deletes PerfMemory resources
3483 // + Return to caller
3484
3485 bool Threads::destroy_vm() {
3486 JavaThread* thread = JavaThread::current();
3487
3488 // Wait until we are the last non-daemon thread to execute
3489 { MutexLocker nu(Threads_lock);
3490 while (Threads::number_of_non_daemon_threads() > 1 )
3491 // This wait should make safepoint checks, wait without a timeout,
3492 // and wait as a suspend-equivalent condition.
3493 //
3494 // Note: If the FlatProfiler is running and this thread is waiting
3495 // for another non-daemon thread to finish, then the FlatProfiler
3496 // is waiting for the external suspend request on this thread to
3497 // complete. wait_for_ext_suspend_completion() will eventually
3498 // timeout, but that takes time. Making this wait a suspend-
3499 // equivalent condition solves that timeout problem.
3500 //
3501 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
3502 Mutex::_as_suspend_equivalent_flag);
3503 }
3504
3505 // Hang forever on exit if we are reporting an error.
3506 if (ShowMessageBoxOnError && is_error_reported()) {
3507 os::infinite_sleep();
3508 }
3509
3510 if (JDK_Version::is_jdk12x_version()) {
3511 // We are the last thread running, so check if finalizers should be run.
3512 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
3513 HandleMark rm(thread);
3514 Universe::run_finalizers_on_exit();
3515 } else {
3516 // run Java level shutdown hooks
3517 thread->invoke_shutdown_hooks();
3518 }
3519
3520 before_exit(thread);
3521
3522 thread->exit(true);
3523
3524 // Stop VM thread.
3525 {
3526 // 4945125 The vm thread comes to a safepoint during exit.
3527 // GC vm_operations can get caught at the safepoint, and the
3528 // heap is unparseable if they are caught. Grab the Heap_lock
3529 // to prevent this. The GC vm_operations will not be able to
3530 // queue until after the vm thread is dead.
3531 MutexLocker ml(Heap_lock);
3532
3533 VMThread::wait_for_vm_thread_exit();
3534 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3535 VMThread::destroy();
3536 }
3537
3538 // clean up ideal graph printers
3539 #if defined(COMPILER2) && !defined(PRODUCT)
3540 IdealGraphPrinter::clean_up();
3541 #endif
3542
3543 // Now, all Java threads are gone except daemon threads. Daemon threads
3544 // running Java code or in VM are stopped by the Safepoint. However,
3545 // daemon threads executing native code are still running. But they
3546 // will be stopped at native=>Java/VM barriers. Note that we can't
3547 // simply kill or suspend them, as it is inherently deadlock-prone.
3548
3549 #ifndef PRODUCT
3550 // disable function tracing at JNI/JVM barriers
3551 TraceHPI = false;
3552 TraceJNICalls = false;
3553 TraceJVMCalls = false;
3554 TraceRuntimeCalls = false;
3555 #endif
3556
3557 VM_Exit::set_vm_exited();
3558
3559 notify_vm_shutdown();
3560
3561 delete thread;
3562
3563 // exit_globals() will delete tty
3564 exit_globals();
3565
3566 return true;
3567 }
3568
3569
3570 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3571 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3572 return is_supported_jni_version(version);
3573 }
3574
3575
3576 jboolean Threads::is_supported_jni_version(jint version) {
3577 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3578 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3579 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3580 return JNI_FALSE;
3581 }
3582
3583
3584 void Threads::add(JavaThread* p, bool force_daemon) {
3585 // The threads lock must be owned at this point
3586 assert_locked_or_safepoint(Threads_lock);
3587 p->set_next(_thread_list);
3588 _thread_list = p;
3589 _number_of_threads++;
3590 oop threadObj = p->threadObj();
3591 bool daemon = true;
3592 // Bootstrapping problem: threadObj can be null for initial
3593 // JavaThread (or for threads attached via JNI)
3594 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
3595 _number_of_non_daemon_threads++;
3596 daemon = false;
3597 }
3598
3599 ThreadService::add_thread(p, daemon);
3600
3601 // Possible GC point.
3602 Events::log("Thread added: " INTPTR_FORMAT, p);
3603 }
3604
3605 void Threads::remove(JavaThread* p) {
3606 // Extra scope needed for Thread_lock, so we can check
3607 // that we do not remove thread without safepoint code notice
3608 { MutexLocker ml(Threads_lock);
3609
3610 assert(includes(p), "p must be present");
3611
3612 JavaThread* current = _thread_list;
3613 JavaThread* prev = NULL;
3614
3615 while (current != p) {
3616 prev = current;
3617 current = current->next();
3618 }
3619
3620 if (prev) {
3621 prev->set_next(current->next());
3622 } else {
3623 _thread_list = p->next();
3624 }
3625 _number_of_threads--;
3626 oop threadObj = p->threadObj();
3627 bool daemon = true;
3628 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
3629 _number_of_non_daemon_threads--;
3630 daemon = false;
3631
3632 // Only one thread left, do a notify on the Threads_lock so a thread waiting
3633 // on destroy_vm will wake up.
3634 if (number_of_non_daemon_threads() == 1)
3635 Threads_lock->notify_all();
3636 }
3637 ThreadService::remove_thread(p, daemon);
3638
3639 // Make sure that safepoint code disregard this thread. This is needed since
3640 // the thread might mess around with locks after this point. This can cause it
3641 // to do callbacks into the safepoint code. However, the safepoint code is not aware
3642 // of this thread since it is removed from the queue.
3643 p->set_terminated_value();
3644 } // unlock Threads_lock
3645
3646 // Since Events::log uses a lock, we grab it outside the Threads_lock
3647 Events::log("Thread exited: " INTPTR_FORMAT, p);
3648 }
3649
3650 // Threads_lock must be held when this is called (or must be called during a safepoint)
3651 bool Threads::includes(JavaThread* p) {
3652 assert(Threads_lock->is_locked(), "sanity check");
3653 ALL_JAVA_THREADS(q) {
3654 if (q == p ) {
3655 return true;
3656 }
3657 }
3658 return false;
3659 }
3660
3661 // Operations on the Threads list for GC. These are not explicitly locked,
3662 // but the garbage collector must provide a safe context for them to run.
3663 // In particular, these things should never be called when the Threads_lock
3664 // is held by some other thread. (Note: the Safepoint abstraction also
3665 // uses the Threads_lock to gurantee this property. It also makes sure that
3666 // all threads gets blocked when exiting or starting).
3667
3668 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3669 ALL_JAVA_THREADS(p) {
3670 p->oops_do(f, cf);
3671 }
3672 VMThread::vm_thread()->oops_do(f, cf);
3673 }
3674
3675 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) {
3676 // Introduce a mechanism allowing parallel threads to claim threads as
3677 // root groups. Overhead should be small enough to use all the time,
3678 // even in sequential code.
3679 SharedHeap* sh = SharedHeap::heap();
3680 bool is_par = (sh->n_par_threads() > 0);
3681 int cp = SharedHeap::heap()->strong_roots_parity();
3682 ALL_JAVA_THREADS(p) {
3683 if (p->claim_oops_do(is_par, cp)) {
3684 p->oops_do(f, cf);
3685 }
3686 }
3687 VMThread* vmt = VMThread::vm_thread();
3688 if (vmt->claim_oops_do(is_par, cp))
3689 vmt->oops_do(f, cf);
3690 }
3691
3692 #ifndef SERIALGC
3693 // Used by ParallelScavenge
3694 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
3695 ALL_JAVA_THREADS(p) {
3696 q->enqueue(new ThreadRootsTask(p));
3697 }
3698 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
3699 }
3700
3701 // Used by Parallel Old
3702 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
3703 ALL_JAVA_THREADS(p) {
3704 q->enqueue(new ThreadRootsMarkingTask(p));
3705 }
3706 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
3707 }
3708 #endif // SERIALGC
3709
3710 void Threads::nmethods_do(CodeBlobClosure* cf) {
3711 ALL_JAVA_THREADS(p) {
3712 p->nmethods_do(cf);
3713 }
3714 VMThread::vm_thread()->nmethods_do(cf);
3715 }
3716
3717 void Threads::gc_epilogue() {
3718 ALL_JAVA_THREADS(p) {
3719 p->gc_epilogue();
3720 }
3721 }
3722
3723 void Threads::gc_prologue() {
3724 ALL_JAVA_THREADS(p) {
3725 p->gc_prologue();
3726 }
3727 }
3728
3729 void Threads::deoptimized_wrt_marked_nmethods() {
3730 ALL_JAVA_THREADS(p) {
3731 p->deoptimized_wrt_marked_nmethods();
3732 }
3733 }
3734
3735
3736 // Get count Java threads that are waiting to enter the specified monitor.
3737 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
3738 address monitor, bool doLock) {
3739 assert(doLock || SafepointSynchronize::is_at_safepoint(),
3740 "must grab Threads_lock or be at safepoint");
3741 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
3742
3743 int i = 0;
3744 {
3745 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3746 ALL_JAVA_THREADS(p) {
3747 if (p->is_Compiler_thread()) continue;
3748
3749 address pending = (address)p->current_pending_monitor();
3750 if (pending == monitor) { // found a match
3751 if (i < count) result->append(p); // save the first count matches
3752 i++;
3753 }
3754 }
3755 }
3756 return result;
3757 }
3758
3759
3760 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
3761 assert(doLock ||
3762 Threads_lock->owned_by_self() ||
3763 SafepointSynchronize::is_at_safepoint(),
3764 "must grab Threads_lock or be at safepoint");
3765
3766 // NULL owner means not locked so we can skip the search
3767 if (owner == NULL) return NULL;
3768
3769 {
3770 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3771 ALL_JAVA_THREADS(p) {
3772 // first, see if owner is the address of a Java thread
3773 if (owner == (address)p) return p;
3774 }
3775 }
3776 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
3777 if (UseHeavyMonitors) return NULL;
3778
3779 //
3780 // If we didn't find a matching Java thread and we didn't force use of
3781 // heavyweight monitors, then the owner is the stack address of the
3782 // Lock Word in the owning Java thread's stack.
3783 //
3784 JavaThread* the_owner = NULL;
3785 {
3786 MutexLockerEx ml(doLock ? Threads_lock : NULL);
3787 ALL_JAVA_THREADS(q) {
3788 if (q->is_lock_owned(owner)) {
3789 the_owner = q;
3790 break;
3791 }
3792 }
3793 }
3794 assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
3795 return the_owner;
3796 }
3797
3798 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
3799 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
3800 char buf[32];
3801 st->print_cr(os::local_time_string(buf, sizeof(buf)));
3802
3803 st->print_cr("Full thread dump %s (%s %s):",
3804 Abstract_VM_Version::vm_name(),
3805 Abstract_VM_Version::vm_release(),
3806 Abstract_VM_Version::vm_info_string()
3807 );
3808 st->cr();
3809
3810 #ifndef SERIALGC
3811 // Dump concurrent locks
3812 ConcurrentLocksDump concurrent_locks;
3813 if (print_concurrent_locks) {
3814 concurrent_locks.dump_at_safepoint();
3815 }
3816 #endif // SERIALGC
3817
3818 ALL_JAVA_THREADS(p) {
3819 ResourceMark rm;
3820 p->print_on(st);
3821 if (print_stacks) {
3822 if (internal_format) {
3823 p->trace_stack();
3824 } else {
3825 p->print_stack_on(st);
3826 }
3827 }
3828 st->cr();
3829 #ifndef SERIALGC
3830 if (print_concurrent_locks) {
3831 concurrent_locks.print_locks_on(p, st);
3832 }
3833 #endif // SERIALGC
3834 }
3835
3836 VMThread::vm_thread()->print_on(st);
3837 st->cr();
3838 Universe::heap()->print_gc_threads_on(st);
3839 WatcherThread* wt = WatcherThread::watcher_thread();
3840 if (wt != NULL) wt->print_on(st);
3841 st->cr();
3842 CompileBroker::print_compiler_threads_on(st);
3843 st->flush();
3844 }
3845
3846 // Threads::print_on_error() is called by fatal error handler. It's possible
3847 // that VM is not at safepoint and/or current thread is inside signal handler.
3848 // Don't print stack trace, as the stack may not be walkable. Don't allocate
3849 // memory (even in resource area), it might deadlock the error handler.
3850 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
3851 bool found_current = false;
3852 st->print_cr("Java Threads: ( => current thread )");
3853 ALL_JAVA_THREADS(thread) {
3854 bool is_current = (current == thread);
3855 found_current = found_current || is_current;
3856
3857 st->print("%s", is_current ? "=>" : " ");
3858
3859 st->print(PTR_FORMAT, thread);
3860 st->print(" ");
3861 thread->print_on_error(st, buf, buflen);
3862 st->cr();
3863 }
3864 st->cr();
3865
3866 st->print_cr("Other Threads:");
3867 if (VMThread::vm_thread()) {
3868 bool is_current = (current == VMThread::vm_thread());
3869 found_current = found_current || is_current;
3870 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
3871
3872 st->print(PTR_FORMAT, VMThread::vm_thread());
3873 st->print(" ");
3874 VMThread::vm_thread()->print_on_error(st, buf, buflen);
3875 st->cr();
3876 }
3877 WatcherThread* wt = WatcherThread::watcher_thread();
3878 if (wt != NULL) {
3879 bool is_current = (current == wt);
3880 found_current = found_current || is_current;
3881 st->print("%s", is_current ? "=>" : " ");
3882
3883 st->print(PTR_FORMAT, wt);
3884 st->print(" ");
3885 wt->print_on_error(st, buf, buflen);
3886 st->cr();
3887 }
3888 if (!found_current) {
3889 st->cr();
3890 st->print("=>" PTR_FORMAT " (exited) ", current);
3891 current->print_on_error(st, buf, buflen);
3892 st->cr();
3893 }
3894 }
3895
3896
3897 // Lifecycle management for TSM ParkEvents.
3898 // ParkEvents are type-stable (TSM).
3899 // In our particular implementation they happen to be immortal.
3900 //
3901 // We manage concurrency on the FreeList with a CAS-based
3902 // detach-modify-reattach idiom that avoids the ABA problems
3903 // that would otherwise be present in a simple CAS-based
3904 // push-pop implementation. (push-one and pop-all)
3905 //
3906 // Caveat: Allocate() and Release() may be called from threads
3907 // other than the thread associated with the Event!
3908 // If we need to call Allocate() when running as the thread in
3909 // question then look for the PD calls to initialize native TLS.
3910 // Native TLS (Win32/Linux/Solaris) can only be initialized or
3911 // accessed by the associated thread.
3912 // See also pd_initialize().
3913 //
3914 // Note that we could defer associating a ParkEvent with a thread
3915 // until the 1st time the thread calls park(). unpark() calls to
3916 // an unprovisioned thread would be ignored. The first park() call
3917 // for a thread would allocate and associate a ParkEvent and return
3918 // immediately.
3919
3920 volatile int ParkEvent::ListLock = 0 ;
3921 ParkEvent * volatile ParkEvent::FreeList = NULL ;
3922
3923 ParkEvent * ParkEvent::Allocate (Thread * t) {
3924 // In rare cases -- JVM_RawMonitor* operations -- we can find t == null.
3925 ParkEvent * ev ;
3926
3927 // Start by trying to recycle an existing but unassociated
3928 // ParkEvent from the global free list.
3929 for (;;) {
3930 ev = FreeList ;
3931 if (ev == NULL) break ;
3932 // 1: Detach - sequester or privatize the list
3933 // Tantamount to ev = Swap (&FreeList, NULL)
3934 if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) {
3935 continue ;
3936 }
3937
3938 // We've detached the list. The list in-hand is now
3939 // local to this thread. This thread can operate on the
3940 // list without risk of interference from other threads.
3941 // 2: Extract -- pop the 1st element from the list.
3942 ParkEvent * List = ev->FreeNext ;
3943 if (List == NULL) break ;
3944 for (;;) {
3945 // 3: Try to reattach the residual list
3946 guarantee (List != NULL, "invariant") ;
3947 ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
3948 if (Arv == NULL) break ;
3949
3950 // New nodes arrived. Try to detach the recent arrivals.
3951 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
3952 continue ;
3953 }
3954 guarantee (Arv != NULL, "invariant") ;
3955 // 4: Merge Arv into List
3956 ParkEvent * Tail = List ;
3957 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
3958 Tail->FreeNext = Arv ;
3959 }
3960 break ;
3961 }
3962
3963 if (ev != NULL) {
3964 guarantee (ev->AssociatedWith == NULL, "invariant") ;
3965 } else {
3966 // Do this the hard way -- materialize a new ParkEvent.
3967 // In rare cases an allocating thread might detach a long list --
3968 // installing null into FreeList -- and then stall or be obstructed.
3969 // A 2nd thread calling Allocate() would see FreeList == null.
3970 // The list held privately by the 1st thread is unavailable to the 2nd thread.
3971 // In that case the 2nd thread would have to materialize a new ParkEvent,
3972 // even though free ParkEvents existed in the system. In this case we end up
3973 // with more ParkEvents in circulation than we need, but the race is
3974 // rare and the outcome is benign. Ideally, the # of extant ParkEvents
3975 // is equal to the maximum # of threads that existed at any one time.
3976 // Because of the race mentioned above, segments of the freelist
3977 // can be transiently inaccessible. At worst we may end up with the
3978 // # of ParkEvents in circulation slightly above the ideal.
3979 // Note that if we didn't have the TSM/immortal constraint, then
3980 // when reattaching, above, we could trim the list.
3981 ev = new ParkEvent () ;
3982 guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ;
3983 }
3984 ev->reset() ; // courtesy to caller
3985 ev->AssociatedWith = t ; // Associate ev with t
3986 ev->FreeNext = NULL ;
3987 return ev ;
3988 }
3989
3990 void ParkEvent::Release (ParkEvent * ev) {
3991 if (ev == NULL) return ;
3992 guarantee (ev->FreeNext == NULL , "invariant") ;
3993 ev->AssociatedWith = NULL ;
3994 for (;;) {
3995 // Push ev onto FreeList
3996 // The mechanism is "half" lock-free.
3997 ParkEvent * List = FreeList ;
3998 ev->FreeNext = List ;
3999 if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ;
4000 }
4001 }
4002
4003 // Override operator new and delete so we can ensure that the
4004 // least significant byte of ParkEvent addresses is 0.
4005 // Beware that excessive address alignment is undesirable
4006 // as it can result in D$ index usage imbalance as
4007 // well as bank access imbalance on Niagara-like platforms,
4008 // although Niagara's hash function should help.
4009
4010 void * ParkEvent::operator new (size_t sz) {
4011 return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ;
4012 }
4013
4014 void ParkEvent::operator delete (void * a) {
4015 // ParkEvents are type-stable and immortal ...
4016 ShouldNotReachHere();
4017 }
4018
4019
4020 // 6399321 As a temporary measure we copied & modified the ParkEvent::
4021 // allocate() and release() code for use by Parkers. The Parker:: forms
4022 // will eventually be removed as we consolide and shift over to ParkEvents
4023 // for both builtin synchronization and JSR166 operations.
4024
4025 volatile int Parker::ListLock = 0 ;
4026 Parker * volatile Parker::FreeList = NULL ;
4027
4028 Parker * Parker::Allocate (JavaThread * t) {
4029 guarantee (t != NULL, "invariant") ;
4030 Parker * p ;
4031
4032 // Start by trying to recycle an existing but unassociated
4033 // Parker from the global free list.
4034 for (;;) {
4035 p = FreeList ;
4036 if (p == NULL) break ;
4037 // 1: Detach
4038 // Tantamount to p = Swap (&FreeList, NULL)
4039 if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) {
4040 continue ;
4041 }
4042
4043 // We've detached the list. The list in-hand is now
4044 // local to this thread. This thread can operate on the
4045 // list without risk of interference from other threads.
4046 // 2: Extract -- pop the 1st element from the list.
4047 Parker * List = p->FreeNext ;
4048 if (List == NULL) break ;
4049 for (;;) {
4050 // 3: Try to reattach the residual list
4051 guarantee (List != NULL, "invariant") ;
4052 Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
4053 if (Arv == NULL) break ;
4054
4055 // New nodes arrived. Try to detach the recent arrivals.
4056 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
4057 continue ;
4058 }
4059 guarantee (Arv != NULL, "invariant") ;
4060 // 4: Merge Arv into List
4061 Parker * Tail = List ;
4062 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
4063 Tail->FreeNext = Arv ;
4064 }
4065 break ;
4066 }
4067
4068 if (p != NULL) {
4069 guarantee (p->AssociatedWith == NULL, "invariant") ;
4070 } else {
4071 // Do this the hard way -- materialize a new Parker..
4072 // In rare cases an allocating thread might detach
4073 // a long list -- installing null into FreeList --and
4074 // then stall. Another thread calling Allocate() would see
4075 // FreeList == null and then invoke the ctor. In this case we
4076 // end up with more Parkers in circulation than we need, but
4077 // the race is rare and the outcome is benign.
4078 // Ideally, the # of extant Parkers is equal to the
4079 // maximum # of threads that existed at any one time.
4080 // Because of the race mentioned above, segments of the
4081 // freelist can be transiently inaccessible. At worst
4082 // we may end up with the # of Parkers in circulation
4083 // slightly above the ideal.
4084 p = new Parker() ;
4085 }
4086 p->AssociatedWith = t ; // Associate p with t
4087 p->FreeNext = NULL ;
4088 return p ;
4089 }
4090
4091
4092 void Parker::Release (Parker * p) {
4093 if (p == NULL) return ;
4094 guarantee (p->AssociatedWith != NULL, "invariant") ;
4095 guarantee (p->FreeNext == NULL , "invariant") ;
4096 p->AssociatedWith = NULL ;
4097 for (;;) {
4098 // Push p onto FreeList
4099 Parker * List = FreeList ;
4100 p->FreeNext = List ;
4101 if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ;
4102 }
4103 }
4104
4105 void Threads::verify() {
4106 ALL_JAVA_THREADS(p) {
4107 p->verify();
4108 }
4109 VMThread* thread = VMThread::vm_thread();
4110 if (thread != NULL) thread->verify();
4111 }