1 /*
2 * Copyright (c) 1997, 2012, 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 "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "compiler/compileBroker.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/linkResolver.hpp"
34 #include "interpreter/oopMapCache.hpp"
35 #include "jvmtifiles/jvmtiEnv.hpp"
36 #include "memory/gcLocker.inline.hpp"
37 #include "memory/metaspaceShared.hpp"
38 #include "memory/oopFactory.hpp"
39 #include "memory/universe.inline.hpp"
40 #include "oops/instanceKlass.hpp"
41 #include "oops/objArrayOop.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/symbol.hpp"
44 #include "prims/jvm_misc.hpp"
45 #include "prims/jvmtiExport.hpp"
46 #include "prims/jvmtiThreadState.hpp"
47 #include "prims/privilegedStack.hpp"
48 #include "runtime/aprofiler.hpp"
49 #include "runtime/arguments.hpp"
50 #include "runtime/biasedLocking.hpp"
51 #include "runtime/deoptimization.hpp"
52 #include "runtime/fprofiler.hpp"
53 #include "runtime/frame.inline.hpp"
54 #include "runtime/init.hpp"
55 #include "runtime/interfaceSupport.hpp"
56 #include "runtime/java.hpp"
57 #include "runtime/javaCalls.hpp"
58 #include "runtime/jniPeriodicChecker.hpp"
59 #include "runtime/memprofiler.hpp"
60 #include "runtime/mutexLocker.hpp"
61 #include "runtime/objectMonitor.hpp"
62 #include "runtime/osThread.hpp"
63 #include "runtime/safepoint.hpp"
64 #include "runtime/sharedRuntime.hpp"
65 #include "runtime/statSampler.hpp"
66 #include "runtime/stubRoutines.hpp"
67 #include "runtime/task.hpp"
68 #include "runtime/threadCritical.hpp"
69 #include "runtime/threadLocalStorage.hpp"
70 #include "runtime/vframe.hpp"
71 #include "runtime/vframeArray.hpp"
72 #include "runtime/vframe_hp.hpp"
73 #include "runtime/vmThread.hpp"
74 #include "runtime/vm_operations.hpp"
75 #include "services/attachListener.hpp"
76 #include "services/management.hpp"
77 #include "services/memTracker.hpp"
78 #include "services/threadService.hpp"
79 #include "trace/traceEventTypes.hpp"
80 #include "utilities/defaultStream.hpp"
81 #include "utilities/dtrace.hpp"
82 #include "utilities/events.hpp"
83 #include "utilities/preserveException.hpp"
84 #ifdef TARGET_OS_FAMILY_linux
85 # include "os_linux.inline.hpp"
86 # include "thread_linux.inline.hpp"
87 #endif
88 #ifdef TARGET_OS_FAMILY_solaris
89 # include "os_solaris.inline.hpp"
90 # include "thread_solaris.inline.hpp"
91 #endif
92 #ifdef TARGET_OS_FAMILY_windows
93 # include "os_windows.inline.hpp"
94 # include "thread_windows.inline.hpp"
95 #endif
96 #ifdef TARGET_OS_FAMILY_bsd
97 # include "os_bsd.inline.hpp"
98 # include "thread_bsd.inline.hpp"
99 #endif
100 #ifndef SERIALGC
101 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
102 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
103 #include "gc_implementation/parallelScavenge/pcTasks.hpp"
104 #endif
105 #ifdef COMPILER1
106 #include "c1/c1_Compiler.hpp"
107 #endif
108 #ifdef COMPILER2
109 #include "opto/c2compiler.hpp"
110 #include "opto/idealGraphPrinter.hpp"
111 #endif
112
113 #ifdef DTRACE_ENABLED
114
115 // Only bother with this argument setup if dtrace is available
116
117 #ifndef USDT2
118 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin);
119 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end);
120 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t,
121 intptr_t, intptr_t, bool);
122 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t,
123 intptr_t, intptr_t, bool);
124
125 #define DTRACE_THREAD_PROBE(probe, javathread) \
126 { \
127 ResourceMark rm(this); \
128 int len = 0; \
129 const char* name = (javathread)->get_thread_name(); \
130 len = strlen(name); \
131 HS_DTRACE_PROBE5(hotspot, thread__##probe, \
132 name, len, \
133 java_lang_Thread::thread_id((javathread)->threadObj()), \
134 (javathread)->osthread()->thread_id(), \
135 java_lang_Thread::is_daemon((javathread)->threadObj())); \
136 }
137
138 #else /* USDT2 */
139
140 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_PROBE_START
141 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_PROBE_STOP
142
143 #define DTRACE_THREAD_PROBE(probe, javathread) \
144 { \
145 ResourceMark rm(this); \
146 int len = 0; \
147 const char* name = (javathread)->get_thread_name(); \
148 len = strlen(name); \
149 HOTSPOT_THREAD_PROBE_##probe( /* probe = start, stop */ \
150 (char *) name, len, \
151 java_lang_Thread::thread_id((javathread)->threadObj()), \
152 (uintptr_t) (javathread)->osthread()->thread_id(), \
153 java_lang_Thread::is_daemon((javathread)->threadObj())); \
154 }
155
156 #endif /* USDT2 */
157
158 #else // ndef DTRACE_ENABLED
159
160 #define DTRACE_THREAD_PROBE(probe, javathread)
161
162 #endif // ndef DTRACE_ENABLED
163
164
165 // Class hierarchy
166 // - Thread
167 // - VMThread
168 // - WatcherThread
169 // - ConcurrentMarkSweepThread
170 // - JavaThread
171 // - CompilerThread
172
173 // ======= Thread ========
174 // Support for forcing alignment of thread objects for biased locking
175 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
176 if (UseBiasedLocking) {
177 const int alignment = markOopDesc::biased_lock_alignment;
178 size_t aligned_size = size + (alignment - sizeof(intptr_t));
179 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
180 : os::malloc(aligned_size, flags, CURRENT_PC);
181 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment);
182 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
183 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
184 "JavaThread alignment code overflowed allocated storage");
185 if (TraceBiasedLocking) {
186 if (aligned_addr != real_malloc_addr)
187 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
188 real_malloc_addr, aligned_addr);
189 }
190 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
191 return aligned_addr;
192 } else {
193 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
194 : os::malloc(size, flags, CURRENT_PC);
195 }
196 }
197
198 void Thread::operator delete(void* p) {
199 if (UseBiasedLocking) {
200 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
201 FreeHeap(real_malloc_addr, mtThread);
202 } else {
203 FreeHeap(p, mtThread);
204 }
205 }
206
207
208 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
209 // JavaThread
210
211
212 Thread::Thread() {
213 // stack and get_thread
214 set_stack_base(NULL);
215 set_stack_size(0);
216 set_self_raw_id(0);
217 set_lgrp_id(-1);
218
219 // allocated data structures
220 set_osthread(NULL);
221 set_resource_area(new (mtThread)ResourceArea());
222 set_handle_area(new (mtThread) HandleArea(NULL));
223 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(300, true));
224 set_active_handles(NULL);
225 set_free_handle_block(NULL);
226 set_last_handle_mark(NULL);
227
228 // This initial value ==> never claimed.
229 _oops_do_parity = 0;
230
231 // the handle mark links itself to last_handle_mark
232 new HandleMark(this);
233
234 // plain initialization
235 debug_only(_owned_locks = NULL;)
236 debug_only(_allow_allocation_count = 0;)
237 NOT_PRODUCT(_allow_safepoint_count = 0;)
238 NOT_PRODUCT(_skip_gcalot = false;)
239 CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;)
240 _jvmti_env_iteration_count = 0;
241 set_allocated_bytes(0);
242 set_trace_buffer(NULL);
243 _vm_operation_started_count = 0;
244 _vm_operation_completed_count = 0;
245 _current_pending_monitor = NULL;
246 _current_pending_monitor_is_from_java = true;
247 _current_waiting_monitor = NULL;
248 _num_nested_signal = 0;
249 omFreeList = NULL ;
250 omFreeCount = 0 ;
251 omFreeProvision = 32 ;
252 omInUseList = NULL ;
253 omInUseCount = 0 ;
254
255 #ifdef ASSERT
256 _visited_for_critical_count = false;
257 #endif
258
259 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
260 _suspend_flags = 0;
261
262 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
263 _hashStateX = os::random() ;
264 _hashStateY = 842502087 ;
265 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
266 _hashStateW = 273326509 ;
267
268 _OnTrap = 0 ;
269 _schedctl = NULL ;
270 _Stalled = 0 ;
271 _TypeTag = 0x2BAD ;
272
273 // Many of the following fields are effectively final - immutable
274 // Note that nascent threads can't use the Native Monitor-Mutex
275 // construct until the _MutexEvent is initialized ...
276 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
277 // we might instead use a stack of ParkEvents that we could provision on-demand.
278 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
279 // and ::Release()
280 _ParkEvent = ParkEvent::Allocate (this) ;
281 _SleepEvent = ParkEvent::Allocate (this) ;
282 _MutexEvent = ParkEvent::Allocate (this) ;
283 _MuxEvent = ParkEvent::Allocate (this) ;
284
285 #ifdef CHECK_UNHANDLED_OOPS
286 if (CheckUnhandledOops) {
287 _unhandled_oops = new UnhandledOops(this);
288 }
289 #endif // CHECK_UNHANDLED_OOPS
290 #ifdef ASSERT
291 if (UseBiasedLocking) {
292 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
293 assert(this == _real_malloc_address ||
294 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
295 "bug in forced alignment of thread objects");
296 }
297 #endif /* ASSERT */
298 }
299
300 void Thread::initialize_thread_local_storage() {
301 // Note: Make sure this method only calls
302 // non-blocking operations. Otherwise, it might not work
303 // with the thread-startup/safepoint interaction.
304
305 // During Java thread startup, safepoint code should allow this
306 // method to complete because it may need to allocate memory to
307 // store information for the new thread.
308
309 // initialize structure dependent on thread local storage
310 ThreadLocalStorage::set_thread(this);
311
312 // set up any platform-specific state.
313 os::initialize_thread();
314 }
315
316 void Thread::record_stack_base_and_size() {
317 set_stack_base(os::current_stack_base());
318 set_stack_size(os::current_stack_size());
319
320 // record thread's native stack, stack grows downward
321 address low_stack_addr = stack_base() - stack_size();
322 MemTracker::record_thread_stack(low_stack_addr, stack_size(), this,
323 CURRENT_PC);
324 }
325
326
327 Thread::~Thread() {
328 // Reclaim the objectmonitors from the omFreeList of the moribund thread.
329 ObjectSynchronizer::omFlush (this) ;
330
331 // stack_base can be NULL if the thread is never started or exited before
332 // record_stack_base_and_size called. Although, we would like to ensure
333 // that all started threads do call record_stack_base_and_size(), there is
334 // not proper way to enforce that.
335 if (_stack_base != NULL) {
336 address low_stack_addr = stack_base() - stack_size();
337 MemTracker::release_thread_stack(low_stack_addr, stack_size(), this);
338 }
339
340 // deallocate data structures
341 delete resource_area();
342 // since the handle marks are using the handle area, we have to deallocated the root
343 // handle mark before deallocating the thread's handle area,
344 assert(last_handle_mark() != NULL, "check we have an element");
345 delete last_handle_mark();
346 assert(last_handle_mark() == NULL, "check we have reached the end");
347
348 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
349 // We NULL out the fields for good hygiene.
350 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
351 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
352 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
353 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
354
355 delete handle_area();
356 delete metadata_handles();
357
358 // osthread() can be NULL, if creation of thread failed.
359 if (osthread() != NULL) os::free_thread(osthread());
360
361 delete _SR_lock;
362
363 // clear thread local storage if the Thread is deleting itself
364 if (this == Thread::current()) {
365 ThreadLocalStorage::set_thread(NULL);
366 } else {
367 // In the case where we're not the current thread, invalidate all the
368 // caches in case some code tries to get the current thread or the
369 // thread that was destroyed, and gets stale information.
370 ThreadLocalStorage::invalidate_all();
371 }
372 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
373 }
374
375 // NOTE: dummy function for assertion purpose.
376 void Thread::run() {
377 ShouldNotReachHere();
378 }
379
380 #ifdef ASSERT
381 // Private method to check for dangling thread pointer
382 void check_for_dangling_thread_pointer(Thread *thread) {
383 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
384 "possibility of dangling Thread pointer");
385 }
386 #endif
387
388
389 #ifndef PRODUCT
390 // Tracing method for basic thread operations
391 void Thread::trace(const char* msg, const Thread* const thread) {
392 if (!TraceThreadEvents) return;
393 ResourceMark rm;
394 ThreadCritical tc;
395 const char *name = "non-Java thread";
396 int prio = -1;
397 if (thread->is_Java_thread()
398 && !thread->is_Compiler_thread()) {
399 // The Threads_lock must be held to get information about
400 // this thread but may not be in some situations when
401 // tracing thread events.
402 bool release_Threads_lock = false;
403 if (!Threads_lock->owned_by_self()) {
404 Threads_lock->lock();
405 release_Threads_lock = true;
406 }
407 JavaThread* jt = (JavaThread *)thread;
408 name = (char *)jt->get_thread_name();
409 oop thread_oop = jt->threadObj();
410 if (thread_oop != NULL) {
411 prio = java_lang_Thread::priority(thread_oop);
412 }
413 if (release_Threads_lock) {
414 Threads_lock->unlock();
415 }
416 }
417 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
418 }
419 #endif
420
421
422 ThreadPriority Thread::get_priority(const Thread* const thread) {
423 trace("get priority", thread);
424 ThreadPriority priority;
425 // Can return an error!
426 (void)os::get_priority(thread, priority);
427 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
428 return priority;
429 }
430
431 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
432 trace("set priority", thread);
433 debug_only(check_for_dangling_thread_pointer(thread);)
434 // Can return an error!
435 (void)os::set_priority(thread, priority);
436 }
437
438
439 void Thread::start(Thread* thread) {
440 trace("start", thread);
441 // Start is different from resume in that its safety is guaranteed by context or
442 // being called from a Java method synchronized on the Thread object.
443 if (!DisableStartThread) {
444 if (thread->is_Java_thread()) {
445 // Initialize the thread state to RUNNABLE before starting this thread.
446 // Can not set it after the thread started because we do not know the
447 // exact thread state at that time. It could be in MONITOR_WAIT or
448 // in SLEEPING or some other state.
449 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
450 java_lang_Thread::RUNNABLE);
451 }
452 os::start_thread(thread);
453 }
454 }
455
456 // Enqueue a VM_Operation to do the job for us - sometime later
457 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
458 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
459 VMThread::execute(vm_stop);
460 }
461
462
463 //
464 // Check if an external suspend request has completed (or has been
465 // cancelled). Returns true if the thread is externally suspended and
466 // false otherwise.
467 //
468 // The bits parameter returns information about the code path through
469 // the routine. Useful for debugging:
470 //
471 // set in is_ext_suspend_completed():
472 // 0x00000001 - routine was entered
473 // 0x00000010 - routine return false at end
474 // 0x00000100 - thread exited (return false)
475 // 0x00000200 - suspend request cancelled (return false)
476 // 0x00000400 - thread suspended (return true)
477 // 0x00001000 - thread is in a suspend equivalent state (return true)
478 // 0x00002000 - thread is native and walkable (return true)
479 // 0x00004000 - thread is native_trans and walkable (needed retry)
480 //
481 // set in wait_for_ext_suspend_completion():
482 // 0x00010000 - routine was entered
483 // 0x00020000 - suspend request cancelled before loop (return false)
484 // 0x00040000 - thread suspended before loop (return true)
485 // 0x00080000 - suspend request cancelled in loop (return false)
486 // 0x00100000 - thread suspended in loop (return true)
487 // 0x00200000 - suspend not completed during retry loop (return false)
488 //
489
490 // Helper class for tracing suspend wait debug bits.
491 //
492 // 0x00000100 indicates that the target thread exited before it could
493 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
494 // 0x00080000 each indicate a cancelled suspend request so they don't
495 // count as wait failures either.
496 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
497
498 class TraceSuspendDebugBits : public StackObj {
499 private:
500 JavaThread * jt;
501 bool is_wait;
502 bool called_by_wait; // meaningful when !is_wait
503 uint32_t * bits;
504
505 public:
506 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
507 uint32_t *_bits) {
508 jt = _jt;
509 is_wait = _is_wait;
510 called_by_wait = _called_by_wait;
511 bits = _bits;
512 }
513
514 ~TraceSuspendDebugBits() {
515 if (!is_wait) {
516 #if 1
517 // By default, don't trace bits for is_ext_suspend_completed() calls.
518 // That trace is very chatty.
519 return;
520 #else
521 if (!called_by_wait) {
522 // If tracing for is_ext_suspend_completed() is enabled, then only
523 // trace calls to it from wait_for_ext_suspend_completion()
524 return;
525 }
526 #endif
527 }
528
529 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
530 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
531 MutexLocker ml(Threads_lock); // needed for get_thread_name()
532 ResourceMark rm;
533
534 tty->print_cr(
535 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
536 jt->get_thread_name(), *bits);
537
538 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
539 }
540 }
541 }
542 };
543 #undef DEBUG_FALSE_BITS
544
545
546 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
547 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
548
549 bool did_trans_retry = false; // only do thread_in_native_trans retry once
550 bool do_trans_retry; // flag to force the retry
551
552 *bits |= 0x00000001;
553
554 do {
555 do_trans_retry = false;
556
557 if (is_exiting()) {
558 // Thread is in the process of exiting. This is always checked
559 // first to reduce the risk of dereferencing a freed JavaThread.
560 *bits |= 0x00000100;
561 return false;
562 }
563
564 if (!is_external_suspend()) {
565 // Suspend request is cancelled. This is always checked before
566 // is_ext_suspended() to reduce the risk of a rogue resume
567 // confusing the thread that made the suspend request.
568 *bits |= 0x00000200;
569 return false;
570 }
571
572 if (is_ext_suspended()) {
573 // thread is suspended
574 *bits |= 0x00000400;
575 return true;
576 }
577
578 // Now that we no longer do hard suspends of threads running
579 // native code, the target thread can be changing thread state
580 // while we are in this routine:
581 //
582 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
583 //
584 // We save a copy of the thread state as observed at this moment
585 // and make our decision about suspend completeness based on the
586 // copy. This closes the race where the thread state is seen as
587 // _thread_in_native_trans in the if-thread_blocked check, but is
588 // seen as _thread_blocked in if-thread_in_native_trans check.
589 JavaThreadState save_state = thread_state();
590
591 if (save_state == _thread_blocked && is_suspend_equivalent()) {
592 // If the thread's state is _thread_blocked and this blocking
593 // condition is known to be equivalent to a suspend, then we can
594 // consider the thread to be externally suspended. This means that
595 // the code that sets _thread_blocked has been modified to do
596 // self-suspension if the blocking condition releases. We also
597 // used to check for CONDVAR_WAIT here, but that is now covered by
598 // the _thread_blocked with self-suspension check.
599 //
600 // Return true since we wouldn't be here unless there was still an
601 // external suspend request.
602 *bits |= 0x00001000;
603 return true;
604 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
605 // Threads running native code will self-suspend on native==>VM/Java
606 // transitions. If its stack is walkable (should always be the case
607 // unless this function is called before the actual java_suspend()
608 // call), then the wait is done.
609 *bits |= 0x00002000;
610 return true;
611 } else if (!called_by_wait && !did_trans_retry &&
612 save_state == _thread_in_native_trans &&
613 frame_anchor()->walkable()) {
614 // The thread is transitioning from thread_in_native to another
615 // thread state. check_safepoint_and_suspend_for_native_trans()
616 // will force the thread to self-suspend. If it hasn't gotten
617 // there yet we may have caught the thread in-between the native
618 // code check above and the self-suspend. Lucky us. If we were
619 // called by wait_for_ext_suspend_completion(), then it
620 // will be doing the retries so we don't have to.
621 //
622 // Since we use the saved thread state in the if-statement above,
623 // there is a chance that the thread has already transitioned to
624 // _thread_blocked by the time we get here. In that case, we will
625 // make a single unnecessary pass through the logic below. This
626 // doesn't hurt anything since we still do the trans retry.
627
628 *bits |= 0x00004000;
629
630 // Once the thread leaves thread_in_native_trans for another
631 // thread state, we break out of this retry loop. We shouldn't
632 // need this flag to prevent us from getting back here, but
633 // sometimes paranoia is good.
634 did_trans_retry = true;
635
636 // We wait for the thread to transition to a more usable state.
637 for (int i = 1; i <= SuspendRetryCount; i++) {
638 // We used to do an "os::yield_all(i)" call here with the intention
639 // that yielding would increase on each retry. However, the parameter
640 // is ignored on Linux which means the yield didn't scale up. Waiting
641 // on the SR_lock below provides a much more predictable scale up for
642 // the delay. It also provides a simple/direct point to check for any
643 // safepoint requests from the VMThread
644
645 // temporarily drops SR_lock while doing wait with safepoint check
646 // (if we're a JavaThread - the WatcherThread can also call this)
647 // and increase delay with each retry
648 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
649
650 // check the actual thread state instead of what we saved above
651 if (thread_state() != _thread_in_native_trans) {
652 // the thread has transitioned to another thread state so
653 // try all the checks (except this one) one more time.
654 do_trans_retry = true;
655 break;
656 }
657 } // end retry loop
658
659
660 }
661 } while (do_trans_retry);
662
663 *bits |= 0x00000010;
664 return false;
665 }
666
667 //
668 // Wait for an external suspend request to complete (or be cancelled).
669 // Returns true if the thread is externally suspended and false otherwise.
670 //
671 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
672 uint32_t *bits) {
673 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
674 false /* !called_by_wait */, bits);
675
676 // local flag copies to minimize SR_lock hold time
677 bool is_suspended;
678 bool pending;
679 uint32_t reset_bits;
680
681 // set a marker so is_ext_suspend_completed() knows we are the caller
682 *bits |= 0x00010000;
683
684 // We use reset_bits to reinitialize the bits value at the top of
685 // each retry loop. This allows the caller to make use of any
686 // unused bits for their own marking purposes.
687 reset_bits = *bits;
688
689 {
690 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
691 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
692 delay, bits);
693 pending = is_external_suspend();
694 }
695 // must release SR_lock to allow suspension to complete
696
697 if (!pending) {
698 // A cancelled suspend request is the only false return from
699 // is_ext_suspend_completed() that keeps us from entering the
700 // retry loop.
701 *bits |= 0x00020000;
702 return false;
703 }
704
705 if (is_suspended) {
706 *bits |= 0x00040000;
707 return true;
708 }
709
710 for (int i = 1; i <= retries; i++) {
711 *bits = reset_bits; // reinit to only track last retry
712
713 // We used to do an "os::yield_all(i)" call here with the intention
714 // that yielding would increase on each retry. However, the parameter
715 // is ignored on Linux which means the yield didn't scale up. Waiting
716 // on the SR_lock below provides a much more predictable scale up for
717 // the delay. It also provides a simple/direct point to check for any
718 // safepoint requests from the VMThread
719
720 {
721 MutexLocker ml(SR_lock());
722 // wait with safepoint check (if we're a JavaThread - the WatcherThread
723 // can also call this) and increase delay with each retry
724 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
725
726 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
727 delay, bits);
728
729 // It is possible for the external suspend request to be cancelled
730 // (by a resume) before the actual suspend operation is completed.
731 // Refresh our local copy to see if we still need to wait.
732 pending = is_external_suspend();
733 }
734
735 if (!pending) {
736 // A cancelled suspend request is the only false return from
737 // is_ext_suspend_completed() that keeps us from staying in the
738 // retry loop.
739 *bits |= 0x00080000;
740 return false;
741 }
742
743 if (is_suspended) {
744 *bits |= 0x00100000;
745 return true;
746 }
747 } // end retry loop
748
749 // thread did not suspend after all our retries
750 *bits |= 0x00200000;
751 return false;
752 }
753
754 #ifndef PRODUCT
755 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
756
757 // This should not need to be atomic as the only way for simultaneous
758 // updates is via interrupts. Even then this should be rare or non-existant
759 // and we don't care that much anyway.
760
761 int index = _jmp_ring_index;
762 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
763 _jmp_ring[index]._target = (intptr_t) target;
764 _jmp_ring[index]._instruction = (intptr_t) instr;
765 _jmp_ring[index]._file = file;
766 _jmp_ring[index]._line = line;
767 }
768 #endif /* PRODUCT */
769
770 // Called by flat profiler
771 // Callers have already called wait_for_ext_suspend_completion
772 // The assertion for that is currently too complex to put here:
773 bool JavaThread::profile_last_Java_frame(frame* _fr) {
774 bool gotframe = false;
775 // self suspension saves needed state.
776 if (has_last_Java_frame() && _anchor.walkable()) {
777 *_fr = pd_last_frame();
778 gotframe = true;
779 }
780 return gotframe;
781 }
782
783 void Thread::interrupt(Thread* thread) {
784 trace("interrupt", thread);
785 debug_only(check_for_dangling_thread_pointer(thread);)
786 os::interrupt(thread);
787 }
788
789 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
790 trace("is_interrupted", thread);
791 debug_only(check_for_dangling_thread_pointer(thread);)
792 // Note: If clear_interrupted==false, this simply fetches and
793 // returns the value of the field osthread()->interrupted().
794 return os::is_interrupted(thread, clear_interrupted);
795 }
796
797
798 // GC Support
799 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
800 jint thread_parity = _oops_do_parity;
801 if (thread_parity != strong_roots_parity) {
802 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
803 if (res == thread_parity) {
804 return true;
805 } else {
806 guarantee(res == strong_roots_parity, "Or else what?");
807 assert(SharedHeap::heap()->workers()->active_workers() > 0,
808 "Should only fail when parallel.");
809 return false;
810 }
811 }
812 assert(SharedHeap::heap()->workers()->active_workers() > 0,
813 "Should only fail when parallel.");
814 return false;
815 }
816
817 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
818 active_handles()->oops_do(f);
819 // Do oop for ThreadShadow
820 f->do_oop((oop*)&_pending_exception);
821 handle_area()->oops_do(f);
822 }
823
824 void Thread::nmethods_do(CodeBlobClosure* cf) {
825 // no nmethods in a generic thread...
826 }
827
828 void Thread::metadata_do(void f(Metadata*)) {
829 if (metadata_handles() != NULL) {
830 for (int i = 0; i< metadata_handles()->length(); i++) {
831 f(metadata_handles()->at(i));
832 }
833 }
834 }
835
836 void Thread::print_on(outputStream* st) const {
837 // get_priority assumes osthread initialized
838 if (osthread() != NULL) {
839 st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this);
840 osthread()->print_on(st);
841 }
842 debug_only(if (WizardMode) print_owned_locks_on(st);)
843 }
844
845 // Thread::print_on_error() is called by fatal error handler. Don't use
846 // any lock or allocate memory.
847 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
848 if (is_VM_thread()) st->print("VMThread");
849 else if (is_Compiler_thread()) st->print("CompilerThread");
850 else if (is_Java_thread()) st->print("JavaThread");
851 else if (is_GC_task_thread()) st->print("GCTaskThread");
852 else if (is_Watcher_thread()) st->print("WatcherThread");
853 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
854 else st->print("Thread");
855
856 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
857 _stack_base - _stack_size, _stack_base);
858
859 if (osthread()) {
860 st->print(" [id=%d]", osthread()->thread_id());
861 }
862 }
863
864 #ifdef ASSERT
865 void Thread::print_owned_locks_on(outputStream* st) const {
866 Monitor *cur = _owned_locks;
867 if (cur == NULL) {
868 st->print(" (no locks) ");
869 } else {
870 st->print_cr(" Locks owned:");
871 while(cur) {
872 cur->print_on(st);
873 cur = cur->next();
874 }
875 }
876 }
877
878 static int ref_use_count = 0;
879
880 bool Thread::owns_locks_but_compiled_lock() const {
881 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
882 if (cur != Compile_lock) return true;
883 }
884 return false;
885 }
886
887
888 #endif
889
890 #ifndef PRODUCT
891
892 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
893 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
894 // no threads which allow_vm_block's are held
895 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
896 // Check if current thread is allowed to block at a safepoint
897 if (!(_allow_safepoint_count == 0))
898 fatal("Possible safepoint reached by thread that does not allow it");
899 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
900 fatal("LEAF method calling lock?");
901 }
902
903 #ifdef ASSERT
904 if (potential_vm_operation && is_Java_thread()
905 && !Universe::is_bootstrapping()) {
906 // Make sure we do not hold any locks that the VM thread also uses.
907 // This could potentially lead to deadlocks
908 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
909 // Threads_lock is special, since the safepoint synchronization will not start before this is
910 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
911 // since it is used to transfer control between JavaThreads and the VMThread
912 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
913 if ( (cur->allow_vm_block() &&
914 cur != Threads_lock &&
915 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
916 cur != VMOperationRequest_lock &&
917 cur != VMOperationQueue_lock) ||
918 cur->rank() == Mutex::special) {
919 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
920 }
921 }
922 }
923
924 if (GCALotAtAllSafepoints) {
925 // We could enter a safepoint here and thus have a gc
926 InterfaceSupport::check_gc_alot();
927 }
928 #endif
929 }
930 #endif
931
932 bool Thread::is_in_stack(address adr) const {
933 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
934 address end = os::current_stack_pointer();
935 // Allow non Java threads to call this without stack_base
936 if (_stack_base == NULL) return true;
937 if (stack_base() >= adr && adr >= end) return true;
938
939 return false;
940 }
941
942
943 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
944 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
945 // used for compilation in the future. If that change is made, the need for these methods
946 // should be revisited, and they should be removed if possible.
947
948 bool Thread::is_lock_owned(address adr) const {
949 return on_local_stack(adr);
950 }
951
952 bool Thread::set_as_starting_thread() {
953 // NOTE: this must be called inside the main thread.
954 return os::create_main_thread((JavaThread*)this);
955 }
956
957 static void initialize_class(Symbol* class_name, TRAPS) {
958 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
959 InstanceKlass::cast(klass)->initialize(CHECK);
960 }
961
962
963 // Creates the initial ThreadGroup
964 static Handle create_initial_thread_group(TRAPS) {
965 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
966 instanceKlassHandle klass (THREAD, k);
967
968 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
969 {
970 JavaValue result(T_VOID);
971 JavaCalls::call_special(&result,
972 system_instance,
973 klass,
974 vmSymbols::object_initializer_name(),
975 vmSymbols::void_method_signature(),
976 CHECK_NH);
977 }
978 Universe::set_system_thread_group(system_instance());
979
980 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
981 {
982 JavaValue result(T_VOID);
983 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
984 JavaCalls::call_special(&result,
985 main_instance,
986 klass,
987 vmSymbols::object_initializer_name(),
988 vmSymbols::threadgroup_string_void_signature(),
989 system_instance,
990 string,
991 CHECK_NH);
992 }
993 return main_instance;
994 }
995
996 // Creates the initial Thread
997 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
998 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
999 instanceKlassHandle klass (THREAD, k);
1000 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
1001
1002 java_lang_Thread::set_thread(thread_oop(), thread);
1003 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1004 thread->set_threadObj(thread_oop());
1005
1006 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
1007
1008 JavaValue result(T_VOID);
1009 JavaCalls::call_special(&result, thread_oop,
1010 klass,
1011 vmSymbols::object_initializer_name(),
1012 vmSymbols::threadgroup_string_void_signature(),
1013 thread_group,
1014 string,
1015 CHECK_NULL);
1016 return thread_oop();
1017 }
1018
1019 static void call_initializeSystemClass(TRAPS) {
1020 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1021 instanceKlassHandle klass (THREAD, k);
1022
1023 JavaValue result(T_VOID);
1024 JavaCalls::call_static(&result, klass, vmSymbols::initializeSystemClass_name(),
1025 vmSymbols::void_method_signature(), CHECK);
1026 }
1027
1028 char java_runtime_name[128] = "";
1029
1030 // extract the JRE name from sun.misc.Version.java_runtime_name
1031 static const char* get_java_runtime_name(TRAPS) {
1032 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1033 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1034 fieldDescriptor fd;
1035 bool found = k != NULL &&
1036 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(),
1037 vmSymbols::string_signature(), &fd);
1038 if (found) {
1039 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1040 if (name_oop == NULL)
1041 return NULL;
1042 const char* name = java_lang_String::as_utf8_string(name_oop,
1043 java_runtime_name,
1044 sizeof(java_runtime_name));
1045 return name;
1046 } else {
1047 return NULL;
1048 }
1049 }
1050
1051 // General purpose hook into Java code, run once when the VM is initialized.
1052 // The Java library method itself may be changed independently from the VM.
1053 static void call_postVMInitHook(TRAPS) {
1054 Klass* k = SystemDictionary::PostVMInitHook_klass();
1055 instanceKlassHandle klass (THREAD, k);
1056 if (klass.not_null()) {
1057 JavaValue result(T_VOID);
1058 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
1059 vmSymbols::void_method_signature(),
1060 CHECK);
1061 }
1062 }
1063
1064 static void reset_vm_info_property(TRAPS) {
1065 // the vm info string
1066 ResourceMark rm(THREAD);
1067 const char *vm_info = VM_Version::vm_info_string();
1068
1069 // java.lang.System class
1070 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1071 instanceKlassHandle klass (THREAD, k);
1072
1073 // setProperty arguments
1074 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
1075 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
1076
1077 // return value
1078 JavaValue r(T_OBJECT);
1079
1080 // public static String setProperty(String key, String value);
1081 JavaCalls::call_static(&r,
1082 klass,
1083 vmSymbols::setProperty_name(),
1084 vmSymbols::string_string_string_signature(),
1085 key_str,
1086 value_str,
1087 CHECK);
1088 }
1089
1090
1091 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
1092 assert(thread_group.not_null(), "thread group should be specified");
1093 assert(threadObj() == NULL, "should only create Java thread object once");
1094
1095 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
1096 instanceKlassHandle klass (THREAD, k);
1097 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
1098
1099 java_lang_Thread::set_thread(thread_oop(), this);
1100 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1101 set_threadObj(thread_oop());
1102
1103 JavaValue result(T_VOID);
1104 if (thread_name != NULL) {
1105 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
1106 // Thread gets assigned specified name and null target
1107 JavaCalls::call_special(&result,
1108 thread_oop,
1109 klass,
1110 vmSymbols::object_initializer_name(),
1111 vmSymbols::threadgroup_string_void_signature(),
1112 thread_group, // Argument 1
1113 name, // Argument 2
1114 THREAD);
1115 } else {
1116 // Thread gets assigned name "Thread-nnn" and null target
1117 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
1118 JavaCalls::call_special(&result,
1119 thread_oop,
1120 klass,
1121 vmSymbols::object_initializer_name(),
1122 vmSymbols::threadgroup_runnable_void_signature(),
1123 thread_group, // Argument 1
1124 Handle(), // Argument 2
1125 THREAD);
1126 }
1127
1128
1129 if (daemon) {
1130 java_lang_Thread::set_daemon(thread_oop());
1131 }
1132
1133 if (HAS_PENDING_EXCEPTION) {
1134 return;
1135 }
1136
1137 KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
1138 Handle threadObj(this, this->threadObj());
1139
1140 JavaCalls::call_special(&result,
1141 thread_group,
1142 group,
1143 vmSymbols::add_method_name(),
1144 vmSymbols::thread_void_signature(),
1145 threadObj, // Arg 1
1146 THREAD);
1147
1148
1149 }
1150
1151 // NamedThread -- non-JavaThread subclasses with multiple
1152 // uniquely named instances should derive from this.
1153 NamedThread::NamedThread() : Thread() {
1154 _name = NULL;
1155 _processed_thread = NULL;
1156 }
1157
1158 NamedThread::~NamedThread() {
1159 if (_name != NULL) {
1160 FREE_C_HEAP_ARRAY(char, _name, mtThread);
1161 _name = NULL;
1162 }
1163 }
1164
1165 void NamedThread::set_name(const char* format, ...) {
1166 guarantee(_name == NULL, "Only get to set name once.");
1167 _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);
1168 guarantee(_name != NULL, "alloc failure");
1169 va_list ap;
1170 va_start(ap, format);
1171 jio_vsnprintf(_name, max_name_len, format, ap);
1172 va_end(ap);
1173 }
1174
1175 // ======= WatcherThread ========
1176
1177 // The watcher thread exists to simulate timer interrupts. It should
1178 // be replaced by an abstraction over whatever native support for
1179 // timer interrupts exists on the platform.
1180
1181 WatcherThread* WatcherThread::_watcher_thread = NULL;
1182 volatile bool WatcherThread::_should_terminate = false;
1183
1184 WatcherThread::WatcherThread() : Thread() {
1185 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1186 if (os::create_thread(this, os::watcher_thread)) {
1187 _watcher_thread = this;
1188
1189 // Set the watcher thread to the highest OS priority which should not be
1190 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1191 // is created. The only normal thread using this priority is the reference
1192 // handler thread, which runs for very short intervals only.
1193 // If the VMThread's priority is not lower than the WatcherThread profiling
1194 // will be inaccurate.
1195 os::set_priority(this, MaxPriority);
1196 if (!DisableStartThread) {
1197 os::start_thread(this);
1198 }
1199 }
1200 }
1201
1202 void WatcherThread::run() {
1203 assert(this == watcher_thread(), "just checking");
1204
1205 this->record_stack_base_and_size();
1206 this->initialize_thread_local_storage();
1207 this->set_active_handles(JNIHandleBlock::allocate_block());
1208 while(!_should_terminate) {
1209 assert(watcher_thread() == Thread::current(), "thread consistency check");
1210 assert(watcher_thread() == this, "thread consistency check");
1211
1212 // Calculate how long it'll be until the next PeriodicTask work
1213 // should be done, and sleep that amount of time.
1214 size_t time_to_wait = PeriodicTask::time_to_wait();
1215
1216 // we expect this to timeout - we only ever get unparked when
1217 // we should terminate
1218 {
1219 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1220
1221 jlong prev_time = os::javaTimeNanos();
1222 for (;;) {
1223 int res= _SleepEvent->park(time_to_wait);
1224 if (res == OS_TIMEOUT || _should_terminate)
1225 break;
1226 // spurious wakeup of some kind
1227 jlong now = os::javaTimeNanos();
1228 time_to_wait -= (now - prev_time) / 1000000;
1229 if (time_to_wait <= 0)
1230 break;
1231 prev_time = now;
1232 }
1233 }
1234
1235 if (is_error_reported()) {
1236 // A fatal error has happened, the error handler(VMError::report_and_die)
1237 // should abort JVM after creating an error log file. However in some
1238 // rare cases, the error handler itself might deadlock. Here we try to
1239 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1240 //
1241 // This code is in WatcherThread because WatcherThread wakes up
1242 // periodically so the fatal error handler doesn't need to do anything;
1243 // also because the WatcherThread is less likely to crash than other
1244 // threads.
1245
1246 for (;;) {
1247 if (!ShowMessageBoxOnError
1248 && (OnError == NULL || OnError[0] == '\0')
1249 && Arguments::abort_hook() == NULL) {
1250 os::sleep(this, 2 * 60 * 1000, false);
1251 fdStream err(defaultStream::output_fd());
1252 err.print_raw_cr("# [ timer expired, abort... ]");
1253 // skip atexit/vm_exit/vm_abort hooks
1254 os::die();
1255 }
1256
1257 // Wake up 5 seconds later, the fatal handler may reset OnError or
1258 // ShowMessageBoxOnError when it is ready to abort.
1259 os::sleep(this, 5 * 1000, false);
1260 }
1261 }
1262
1263 PeriodicTask::real_time_tick(time_to_wait);
1264
1265 // If we have no more tasks left due to dynamic disenrollment,
1266 // shut down the thread since we don't currently support dynamic enrollment
1267 if (PeriodicTask::num_tasks() == 0) {
1268 _should_terminate = true;
1269 }
1270 }
1271
1272 // Signal that it is terminated
1273 {
1274 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1275 _watcher_thread = NULL;
1276 Terminator_lock->notify();
1277 }
1278
1279 // Thread destructor usually does this..
1280 ThreadLocalStorage::set_thread(NULL);
1281 }
1282
1283 void WatcherThread::start() {
1284 if (watcher_thread() == NULL) {
1285 _should_terminate = false;
1286 // Create the single instance of WatcherThread
1287 new WatcherThread();
1288 }
1289 }
1290
1291 void WatcherThread::stop() {
1292 // it is ok to take late safepoints here, if needed
1293 MutexLocker mu(Terminator_lock);
1294 _should_terminate = true;
1295 OrderAccess::fence(); // ensure WatcherThread sees update in main loop
1296
1297 Thread* watcher = watcher_thread();
1298 if (watcher != NULL)
1299 watcher->_SleepEvent->unpark();
1300
1301 while(watcher_thread() != NULL) {
1302 // This wait should make safepoint checks, wait without a timeout,
1303 // and wait as a suspend-equivalent condition.
1304 //
1305 // Note: If the FlatProfiler is running, then this thread is waiting
1306 // for the WatcherThread to terminate and the WatcherThread, via the
1307 // FlatProfiler task, is waiting for the external suspend request on
1308 // this thread to complete. wait_for_ext_suspend_completion() will
1309 // eventually timeout, but that takes time. Making this wait a
1310 // suspend-equivalent condition solves that timeout problem.
1311 //
1312 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1313 Mutex::_as_suspend_equivalent_flag);
1314 }
1315 }
1316
1317 void WatcherThread::print_on(outputStream* st) const {
1318 st->print("\"%s\" ", name());
1319 Thread::print_on(st);
1320 st->cr();
1321 }
1322
1323 // ======= JavaThread ========
1324
1325 // A JavaThread is a normal Java thread
1326
1327 void JavaThread::initialize() {
1328 // Initialize fields
1329
1330 // Set the claimed par_id to -1 (ie not claiming any par_ids)
1331 set_claimed_par_id(-1);
1332
1333 set_saved_exception_pc(NULL);
1334 set_threadObj(NULL);
1335 _anchor.clear();
1336 set_entry_point(NULL);
1337 set_jni_functions(jni_functions());
1338 set_callee_target(NULL);
1339 set_vm_result(NULL);
1340 set_vm_result_2(NULL);
1341 set_vframe_array_head(NULL);
1342 set_vframe_array_last(NULL);
1343 set_deferred_locals(NULL);
1344 set_deopt_mark(NULL);
1345 set_deopt_nmethod(NULL);
1346 clear_must_deopt_id();
1347 set_monitor_chunks(NULL);
1348 set_next(NULL);
1349 set_thread_state(_thread_new);
1350 set_recorder(NULL);
1351 _terminated = _not_terminated;
1352 _privileged_stack_top = NULL;
1353 _array_for_gc = NULL;
1354 _suspend_equivalent = false;
1355 _in_deopt_handler = 0;
1356 _doing_unsafe_access = false;
1357 _stack_guard_state = stack_guard_unused;
1358 _exception_oop = NULL;
1359 _exception_pc = 0;
1360 _exception_handler_pc = 0;
1361 _is_method_handle_return = 0;
1362 _jvmti_thread_state= NULL;
1363 _should_post_on_exceptions_flag = JNI_FALSE;
1364 _jvmti_get_loaded_classes_closure = NULL;
1365 _interp_only_mode = 0;
1366 _special_runtime_exit_condition = _no_async_condition;
1367 _pending_async_exception = NULL;
1368 _is_compiling = false;
1369 _thread_stat = NULL;
1370 _thread_stat = new ThreadStatistics();
1371 _blocked_on_compilation = false;
1372 _jni_active_critical = 0;
1373 _do_not_unlock_if_synchronized = false;
1374 _cached_monitor_info = NULL;
1375 _parker = Parker::Allocate(this) ;
1376
1377 #ifndef PRODUCT
1378 _jmp_ring_index = 0;
1379 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1380 record_jump(NULL, NULL, NULL, 0);
1381 }
1382 #endif /* PRODUCT */
1383
1384 set_thread_profiler(NULL);
1385 if (FlatProfiler::is_active()) {
1386 // This is where we would decide to either give each thread it's own profiler
1387 // or use one global one from FlatProfiler,
1388 // or up to some count of the number of profiled threads, etc.
1389 ThreadProfiler* pp = new ThreadProfiler();
1390 pp->engage();
1391 set_thread_profiler(pp);
1392 }
1393
1394 // Setup safepoint state info for this thread
1395 ThreadSafepointState::create(this);
1396
1397 debug_only(_java_call_counter = 0);
1398
1399 // JVMTI PopFrame support
1400 _popframe_condition = popframe_inactive;
1401 _popframe_preserved_args = NULL;
1402 _popframe_preserved_args_size = 0;
1403
1404 pd_initialize();
1405 }
1406
1407 #ifndef SERIALGC
1408 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1409 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1410 #endif // !SERIALGC
1411
1412 JavaThread::JavaThread(bool is_attaching_via_jni) :
1413 Thread()
1414 #ifndef SERIALGC
1415 , _satb_mark_queue(&_satb_mark_queue_set),
1416 _dirty_card_queue(&_dirty_card_queue_set)
1417 #endif // !SERIALGC
1418 {
1419 initialize();
1420 if (is_attaching_via_jni) {
1421 _jni_attach_state = _attaching_via_jni;
1422 } else {
1423 _jni_attach_state = _not_attaching_via_jni;
1424 }
1425 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor");
1426 _safepoint_visible = false;
1427 }
1428
1429 bool JavaThread::reguard_stack(address cur_sp) {
1430 if (_stack_guard_state != stack_guard_yellow_disabled) {
1431 return true; // Stack already guarded or guard pages not needed.
1432 }
1433
1434 if (register_stack_overflow()) {
1435 // For those architectures which have separate register and
1436 // memory stacks, we must check the register stack to see if
1437 // it has overflowed.
1438 return false;
1439 }
1440
1441 // Java code never executes within the yellow zone: the latter is only
1442 // there to provoke an exception during stack banging. If java code
1443 // is executing there, either StackShadowPages should be larger, or
1444 // some exception code in c1, c2 or the interpreter isn't unwinding
1445 // when it should.
1446 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1447
1448 enable_stack_yellow_zone();
1449 return true;
1450 }
1451
1452 bool JavaThread::reguard_stack(void) {
1453 return reguard_stack(os::current_stack_pointer());
1454 }
1455
1456
1457 void JavaThread::block_if_vm_exited() {
1458 if (_terminated == _vm_exited) {
1459 // _vm_exited is set at safepoint, and Threads_lock is never released
1460 // we will block here forever
1461 Threads_lock->lock_without_safepoint_check();
1462 ShouldNotReachHere();
1463 }
1464 }
1465
1466
1467 // Remove this ifdef when C1 is ported to the compiler interface.
1468 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1469
1470 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1471 Thread()
1472 #ifndef SERIALGC
1473 , _satb_mark_queue(&_satb_mark_queue_set),
1474 _dirty_card_queue(&_dirty_card_queue_set)
1475 #endif // !SERIALGC
1476 {
1477 if (TraceThreadEvents) {
1478 tty->print_cr("creating thread %p", this);
1479 }
1480 initialize();
1481 _jni_attach_state = _not_attaching_via_jni;
1482 set_entry_point(entry_point);
1483 // Create the native thread itself.
1484 // %note runtime_23
1485 os::ThreadType thr_type = os::java_thread;
1486 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1487 os::java_thread;
1488 os::create_thread(this, thr_type, stack_sz);
1489 _safepoint_visible = false;
1490 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1491 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1492 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1493 // the exception consists of creating the exception object & initializing it, initialization
1494 // will leave the VM via a JavaCall and then all locks must be unlocked).
1495 //
1496 // The thread is still suspended when we reach here. Thread must be explicit started
1497 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1498 // by calling Threads:add. The reason why this is not done here, is because the thread
1499 // object must be fully initialized (take a look at JVM_Start)
1500 }
1501
1502 JavaThread::~JavaThread() {
1503 if (TraceThreadEvents) {
1504 tty->print_cr("terminate thread %p", this);
1505 }
1506
1507 // Info NMT that this JavaThread is exiting, its memory
1508 // recorder should be collected
1509 assert(!is_safepoint_visible(), "wrong state");
1510 MemTracker::thread_exiting(this);
1511
1512 // JSR166 -- return the parker to the free list
1513 Parker::Release(_parker);
1514 _parker = NULL ;
1515
1516 // Free any remaining previous UnrollBlock
1517 vframeArray* old_array = vframe_array_last();
1518
1519 if (old_array != NULL) {
1520 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1521 old_array->set_unroll_block(NULL);
1522 delete old_info;
1523 delete old_array;
1524 }
1525
1526 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1527 if (deferred != NULL) {
1528 // This can only happen if thread is destroyed before deoptimization occurs.
1529 assert(deferred->length() != 0, "empty array!");
1530 do {
1531 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1532 deferred->remove_at(0);
1533 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1534 delete dlv;
1535 } while (deferred->length() != 0);
1536 delete deferred;
1537 }
1538
1539 // All Java related clean up happens in exit
1540 ThreadSafepointState::destroy(this);
1541 if (_thread_profiler != NULL) delete _thread_profiler;
1542 if (_thread_stat != NULL) delete _thread_stat;
1543 }
1544
1545
1546 // The first routine called by a new Java thread
1547 void JavaThread::run() {
1548 // initialize thread-local alloc buffer related fields
1549 this->initialize_tlab();
1550
1551 // used to test validitity of stack trace backs
1552 this->record_base_of_stack_pointer();
1553
1554 // Record real stack base and size.
1555 this->record_stack_base_and_size();
1556
1557 // Initialize thread local storage; set before calling MutexLocker
1558 this->initialize_thread_local_storage();
1559
1560 this->create_stack_guard_pages();
1561
1562 this->cache_global_variables();
1563
1564 // Thread is now sufficient initialized to be handled by the safepoint code as being
1565 // in the VM. Change thread state from _thread_new to _thread_in_vm
1566 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1567
1568 assert(JavaThread::current() == this, "sanity check");
1569 assert(!Thread::current()->owns_locks(), "sanity check");
1570
1571 DTRACE_THREAD_PROBE(start, this);
1572
1573 // This operation might block. We call that after all safepoint checks for a new thread has
1574 // been completed.
1575 this->set_active_handles(JNIHandleBlock::allocate_block());
1576
1577 if (JvmtiExport::should_post_thread_life()) {
1578 JvmtiExport::post_thread_start(this);
1579 }
1580
1581 EVENT_BEGIN(TraceEventThreadStart, event);
1582 EVENT_COMMIT(event,
1583 EVENT_SET(event, javalangthread, java_lang_Thread::thread_id(this->threadObj())));
1584
1585 // We call another function to do the rest so we are sure that the stack addresses used
1586 // from there will be lower than the stack base just computed
1587 thread_main_inner();
1588
1589 // Note, thread is no longer valid at this point!
1590 }
1591
1592
1593 void JavaThread::thread_main_inner() {
1594 assert(JavaThread::current() == this, "sanity check");
1595 assert(this->threadObj() != NULL, "just checking");
1596
1597 // Execute thread entry point unless this thread has a pending exception
1598 // or has been stopped before starting.
1599 // Note: Due to JVM_StopThread we can have pending exceptions already!
1600 if (!this->has_pending_exception() &&
1601 !java_lang_Thread::is_stillborn(this->threadObj())) {
1602 {
1603 ResourceMark rm(this);
1604 this->set_native_thread_name(this->get_thread_name());
1605 }
1606 HandleMark hm(this);
1607 this->entry_point()(this, this);
1608 }
1609
1610 DTRACE_THREAD_PROBE(stop, this);
1611
1612 this->exit(false);
1613 delete this;
1614 }
1615
1616
1617 static void ensure_join(JavaThread* thread) {
1618 // We do not need to grap the Threads_lock, since we are operating on ourself.
1619 Handle threadObj(thread, thread->threadObj());
1620 assert(threadObj.not_null(), "java thread object must exist");
1621 ObjectLocker lock(threadObj, thread);
1622 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1623 thread->clear_pending_exception();
1624 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1625 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1626 // Clear the native thread instance - this makes isAlive return false and allows the join()
1627 // to complete once we've done the notify_all below
1628 java_lang_Thread::set_thread(threadObj(), NULL);
1629 lock.notify_all(thread);
1630 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1631 thread->clear_pending_exception();
1632 }
1633
1634
1635 // For any new cleanup additions, please check to see if they need to be applied to
1636 // cleanup_failed_attach_current_thread as well.
1637 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1638 assert(this == JavaThread::current(), "thread consistency check");
1639 if (!InitializeJavaLangSystem) return;
1640
1641 HandleMark hm(this);
1642 Handle uncaught_exception(this, this->pending_exception());
1643 this->clear_pending_exception();
1644 Handle threadObj(this, this->threadObj());
1645 assert(threadObj.not_null(), "Java thread object should be created");
1646
1647 if (get_thread_profiler() != NULL) {
1648 get_thread_profiler()->disengage();
1649 ResourceMark rm;
1650 get_thread_profiler()->print(get_thread_name());
1651 }
1652
1653
1654 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1655 {
1656 EXCEPTION_MARK;
1657
1658 CLEAR_PENDING_EXCEPTION;
1659 }
1660 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1661 // has to be fixed by a runtime query method
1662 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1663 // JSR-166: change call from from ThreadGroup.uncaughtException to
1664 // java.lang.Thread.dispatchUncaughtException
1665 if (uncaught_exception.not_null()) {
1666 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1667 {
1668 EXCEPTION_MARK;
1669 // Check if the method Thread.dispatchUncaughtException() exists. If so
1670 // call it. Otherwise we have an older library without the JSR-166 changes,
1671 // so call ThreadGroup.uncaughtException()
1672 KlassHandle recvrKlass(THREAD, threadObj->klass());
1673 CallInfo callinfo;
1674 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1675 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1676 vmSymbols::dispatchUncaughtException_name(),
1677 vmSymbols::throwable_void_signature(),
1678 KlassHandle(), false, false, THREAD);
1679 CLEAR_PENDING_EXCEPTION;
1680 methodHandle method = callinfo.selected_method();
1681 if (method.not_null()) {
1682 JavaValue result(T_VOID);
1683 JavaCalls::call_virtual(&result,
1684 threadObj, thread_klass,
1685 vmSymbols::dispatchUncaughtException_name(),
1686 vmSymbols::throwable_void_signature(),
1687 uncaught_exception,
1688 THREAD);
1689 } else {
1690 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1691 JavaValue result(T_VOID);
1692 JavaCalls::call_virtual(&result,
1693 group, thread_group,
1694 vmSymbols::uncaughtException_name(),
1695 vmSymbols::thread_throwable_void_signature(),
1696 threadObj, // Arg 1
1697 uncaught_exception, // Arg 2
1698 THREAD);
1699 }
1700 if (HAS_PENDING_EXCEPTION) {
1701 ResourceMark rm(this);
1702 jio_fprintf(defaultStream::error_stream(),
1703 "\nException: %s thrown from the UncaughtExceptionHandler"
1704 " in thread \"%s\"\n",
1705 Klass::cast(pending_exception()->klass())->external_name(),
1706 get_thread_name());
1707 CLEAR_PENDING_EXCEPTION;
1708 }
1709 }
1710 }
1711
1712 // Called before the java thread exit since we want to read info
1713 // from java_lang_Thread object
1714 EVENT_BEGIN(TraceEventThreadEnd, event);
1715 EVENT_COMMIT(event,
1716 EVENT_SET(event, javalangthread, java_lang_Thread::thread_id(this->threadObj())));
1717
1718 // Call after last event on thread
1719 EVENT_THREAD_EXIT(this);
1720
1721 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1722 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1723 // is deprecated anyhow.
1724 { int count = 3;
1725 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1726 EXCEPTION_MARK;
1727 JavaValue result(T_VOID);
1728 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1729 JavaCalls::call_virtual(&result,
1730 threadObj, thread_klass,
1731 vmSymbols::exit_method_name(),
1732 vmSymbols::void_method_signature(),
1733 THREAD);
1734 CLEAR_PENDING_EXCEPTION;
1735 }
1736 }
1737
1738 // notify JVMTI
1739 if (JvmtiExport::should_post_thread_life()) {
1740 JvmtiExport::post_thread_end(this);
1741 }
1742
1743 // We have notified the agents that we are exiting, before we go on,
1744 // we must check for a pending external suspend request and honor it
1745 // in order to not surprise the thread that made the suspend request.
1746 while (true) {
1747 {
1748 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1749 if (!is_external_suspend()) {
1750 set_terminated(_thread_exiting);
1751 ThreadService::current_thread_exiting(this);
1752 break;
1753 }
1754 // Implied else:
1755 // Things get a little tricky here. We have a pending external
1756 // suspend request, but we are holding the SR_lock so we
1757 // can't just self-suspend. So we temporarily drop the lock
1758 // and then self-suspend.
1759 }
1760
1761 ThreadBlockInVM tbivm(this);
1762 java_suspend_self();
1763
1764 // We're done with this suspend request, but we have to loop around
1765 // and check again. Eventually we will get SR_lock without a pending
1766 // external suspend request and will be able to mark ourselves as
1767 // exiting.
1768 }
1769 // no more external suspends are allowed at this point
1770 } else {
1771 // before_exit() has already posted JVMTI THREAD_END events
1772 }
1773
1774 // Notify waiters on thread object. This has to be done after exit() is called
1775 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1776 // group should have the destroyed bit set before waiters are notified).
1777 ensure_join(this);
1778 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1779
1780 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1781 // held by this thread must be released. A detach operation must only
1782 // get here if there are no Java frames on the stack. Therefore, any
1783 // owned monitors at this point MUST be JNI-acquired monitors which are
1784 // pre-inflated and in the monitor cache.
1785 //
1786 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1787 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1788 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1789 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1790 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1791 }
1792
1793 // These things needs to be done while we are still a Java Thread. Make sure that thread
1794 // is in a consistent state, in case GC happens
1795 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1796
1797 if (active_handles() != NULL) {
1798 JNIHandleBlock* block = active_handles();
1799 set_active_handles(NULL);
1800 JNIHandleBlock::release_block(block);
1801 }
1802
1803 if (free_handle_block() != NULL) {
1804 JNIHandleBlock* block = free_handle_block();
1805 set_free_handle_block(NULL);
1806 JNIHandleBlock::release_block(block);
1807 }
1808
1809 // These have to be removed while this is still a valid thread.
1810 remove_stack_guard_pages();
1811
1812 if (UseTLAB) {
1813 tlab().make_parsable(true); // retire TLAB
1814 }
1815
1816 if (JvmtiEnv::environments_might_exist()) {
1817 JvmtiExport::cleanup_thread(this);
1818 }
1819
1820 #ifndef SERIALGC
1821 // We must flush G1-related buffers before removing a thread from
1822 // the list of active threads.
1823 if (UseG1GC) {
1824 flush_barrier_queues();
1825 }
1826 #endif
1827
1828 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1829 Threads::remove(this);
1830 }
1831
1832 #ifndef SERIALGC
1833 // Flush G1-related queues.
1834 void JavaThread::flush_barrier_queues() {
1835 satb_mark_queue().flush();
1836 dirty_card_queue().flush();
1837 }
1838
1839 void JavaThread::initialize_queues() {
1840 assert(!SafepointSynchronize::is_at_safepoint(),
1841 "we should not be at a safepoint");
1842
1843 ObjPtrQueue& satb_queue = satb_mark_queue();
1844 SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
1845 // The SATB queue should have been constructed with its active
1846 // field set to false.
1847 assert(!satb_queue.is_active(), "SATB queue should not be active");
1848 assert(satb_queue.is_empty(), "SATB queue should be empty");
1849 // If we are creating the thread during a marking cycle, we should
1850 // set the active field of the SATB queue to true.
1851 if (satb_queue_set.is_active()) {
1852 satb_queue.set_active(true);
1853 }
1854
1855 DirtyCardQueue& dirty_queue = dirty_card_queue();
1856 // The dirty card queue should have been constructed with its
1857 // active field set to true.
1858 assert(dirty_queue.is_active(), "dirty card queue should be active");
1859 }
1860 #endif // !SERIALGC
1861
1862 void JavaThread::cleanup_failed_attach_current_thread() {
1863 if (get_thread_profiler() != NULL) {
1864 get_thread_profiler()->disengage();
1865 ResourceMark rm;
1866 get_thread_profiler()->print(get_thread_name());
1867 }
1868
1869 if (active_handles() != NULL) {
1870 JNIHandleBlock* block = active_handles();
1871 set_active_handles(NULL);
1872 JNIHandleBlock::release_block(block);
1873 }
1874
1875 if (free_handle_block() != NULL) {
1876 JNIHandleBlock* block = free_handle_block();
1877 set_free_handle_block(NULL);
1878 JNIHandleBlock::release_block(block);
1879 }
1880
1881 // These have to be removed while this is still a valid thread.
1882 remove_stack_guard_pages();
1883
1884 if (UseTLAB) {
1885 tlab().make_parsable(true); // retire TLAB, if any
1886 }
1887
1888 #ifndef SERIALGC
1889 if (UseG1GC) {
1890 flush_barrier_queues();
1891 }
1892 #endif
1893
1894 Threads::remove(this);
1895 delete this;
1896 }
1897
1898
1899
1900
1901 JavaThread* JavaThread::active() {
1902 Thread* thread = ThreadLocalStorage::thread();
1903 assert(thread != NULL, "just checking");
1904 if (thread->is_Java_thread()) {
1905 return (JavaThread*) thread;
1906 } else {
1907 assert(thread->is_VM_thread(), "this must be a vm thread");
1908 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1909 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1910 assert(ret->is_Java_thread(), "must be a Java thread");
1911 return ret;
1912 }
1913 }
1914
1915 bool JavaThread::is_lock_owned(address adr) const {
1916 if (Thread::is_lock_owned(adr)) return true;
1917
1918 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1919 if (chunk->contains(adr)) return true;
1920 }
1921
1922 return false;
1923 }
1924
1925
1926 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1927 chunk->set_next(monitor_chunks());
1928 set_monitor_chunks(chunk);
1929 }
1930
1931 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1932 guarantee(monitor_chunks() != NULL, "must be non empty");
1933 if (monitor_chunks() == chunk) {
1934 set_monitor_chunks(chunk->next());
1935 } else {
1936 MonitorChunk* prev = monitor_chunks();
1937 while (prev->next() != chunk) prev = prev->next();
1938 prev->set_next(chunk->next());
1939 }
1940 }
1941
1942 // JVM support.
1943
1944 // Note: this function shouldn't block if it's called in
1945 // _thread_in_native_trans state (such as from
1946 // check_special_condition_for_native_trans()).
1947 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
1948
1949 if (has_last_Java_frame() && has_async_condition()) {
1950 // If we are at a polling page safepoint (not a poll return)
1951 // then we must defer async exception because live registers
1952 // will be clobbered by the exception path. Poll return is
1953 // ok because the call we a returning from already collides
1954 // with exception handling registers and so there is no issue.
1955 // (The exception handling path kills call result registers but
1956 // this is ok since the exception kills the result anyway).
1957
1958 if (is_at_poll_safepoint()) {
1959 // if the code we are returning to has deoptimized we must defer
1960 // the exception otherwise live registers get clobbered on the
1961 // exception path before deoptimization is able to retrieve them.
1962 //
1963 RegisterMap map(this, false);
1964 frame caller_fr = last_frame().sender(&map);
1965 assert(caller_fr.is_compiled_frame(), "what?");
1966 if (caller_fr.is_deoptimized_frame()) {
1967 if (TraceExceptions) {
1968 ResourceMark rm;
1969 tty->print_cr("deferred async exception at compiled safepoint");
1970 }
1971 return;
1972 }
1973 }
1974 }
1975
1976 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
1977 if (condition == _no_async_condition) {
1978 // Conditions have changed since has_special_runtime_exit_condition()
1979 // was called:
1980 // - if we were here only because of an external suspend request,
1981 // then that was taken care of above (or cancelled) so we are done
1982 // - if we were here because of another async request, then it has
1983 // been cleared between the has_special_runtime_exit_condition()
1984 // and now so again we are done
1985 return;
1986 }
1987
1988 // Check for pending async. exception
1989 if (_pending_async_exception != NULL) {
1990 // Only overwrite an already pending exception, if it is not a threadDeath.
1991 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
1992
1993 // We cannot call Exceptions::_throw(...) here because we cannot block
1994 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1995
1996 if (TraceExceptions) {
1997 ResourceMark rm;
1998 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
1999 if (has_last_Java_frame() ) {
2000 frame f = last_frame();
2001 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
2002 }
2003 tty->print_cr(" of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2004 }
2005 _pending_async_exception = NULL;
2006 clear_has_async_exception();
2007 }
2008 }
2009
2010 if (check_unsafe_error &&
2011 condition == _async_unsafe_access_error && !has_pending_exception()) {
2012 condition = _no_async_condition; // done
2013 switch (thread_state()) {
2014 case _thread_in_vm:
2015 {
2016 JavaThread* THREAD = this;
2017 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2018 }
2019 case _thread_in_native:
2020 {
2021 ThreadInVMfromNative tiv(this);
2022 JavaThread* THREAD = this;
2023 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2024 }
2025 case _thread_in_Java:
2026 {
2027 ThreadInVMfromJava tiv(this);
2028 JavaThread* THREAD = this;
2029 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
2030 }
2031 default:
2032 ShouldNotReachHere();
2033 }
2034 }
2035
2036 assert(condition == _no_async_condition || has_pending_exception() ||
2037 (!check_unsafe_error && condition == _async_unsafe_access_error),
2038 "must have handled the async condition, if no exception");
2039 }
2040
2041 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
2042 //
2043 // Check for pending external suspend. Internal suspend requests do
2044 // not use handle_special_runtime_exit_condition().
2045 // If JNIEnv proxies are allowed, don't self-suspend if the target
2046 // thread is not the current thread. In older versions of jdbx, jdbx
2047 // threads could call into the VM with another thread's JNIEnv so we
2048 // can be here operating on behalf of a suspended thread (4432884).
2049 bool do_self_suspend = is_external_suspend_with_lock();
2050 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
2051 //
2052 // Because thread is external suspended the safepoint code will count
2053 // thread as at a safepoint. This can be odd because we can be here
2054 // as _thread_in_Java which would normally transition to _thread_blocked
2055 // at a safepoint. We would like to mark the thread as _thread_blocked
2056 // before calling java_suspend_self like all other callers of it but
2057 // we must then observe proper safepoint protocol. (We can't leave
2058 // _thread_blocked with a safepoint in progress). However we can be
2059 // here as _thread_in_native_trans so we can't use a normal transition
2060 // constructor/destructor pair because they assert on that type of
2061 // transition. We could do something like:
2062 //
2063 // JavaThreadState state = thread_state();
2064 // set_thread_state(_thread_in_vm);
2065 // {
2066 // ThreadBlockInVM tbivm(this);
2067 // java_suspend_self()
2068 // }
2069 // set_thread_state(_thread_in_vm_trans);
2070 // if (safepoint) block;
2071 // set_thread_state(state);
2072 //
2073 // but that is pretty messy. Instead we just go with the way the
2074 // code has worked before and note that this is the only path to
2075 // java_suspend_self that doesn't put the thread in _thread_blocked
2076 // mode.
2077
2078 frame_anchor()->make_walkable(this);
2079 java_suspend_self();
2080
2081 // We might be here for reasons in addition to the self-suspend request
2082 // so check for other async requests.
2083 }
2084
2085 if (check_asyncs) {
2086 check_and_handle_async_exceptions();
2087 }
2088 }
2089
2090 void JavaThread::send_thread_stop(oop java_throwable) {
2091 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
2092 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
2093 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
2094
2095 // Do not throw asynchronous exceptions against the compiler thread
2096 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
2097 if (is_Compiler_thread()) return;
2098
2099 {
2100 // Actually throw the Throwable against the target Thread - however
2101 // only if there is no thread death exception installed already.
2102 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
2103 // If the topmost frame is a runtime stub, then we are calling into
2104 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
2105 // must deoptimize the caller before continuing, as the compiled exception handler table
2106 // may not be valid
2107 if (has_last_Java_frame()) {
2108 frame f = last_frame();
2109 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
2110 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2111 RegisterMap reg_map(this, UseBiasedLocking);
2112 frame compiled_frame = f.sender(®_map);
2113 if (compiled_frame.can_be_deoptimized()) {
2114 Deoptimization::deoptimize(this, compiled_frame, ®_map);
2115 }
2116 }
2117 }
2118
2119 // Set async. pending exception in thread.
2120 set_pending_async_exception(java_throwable);
2121
2122 if (TraceExceptions) {
2123 ResourceMark rm;
2124 tty->print_cr("Pending Async. exception installed of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2125 }
2126 // for AbortVMOnException flag
2127 NOT_PRODUCT(Exceptions::debug_check_abort(InstanceKlass::cast(_pending_async_exception->klass())->external_name()));
2128 }
2129 }
2130
2131
2132 // Interrupt thread so it will wake up from a potential wait()
2133 Thread::interrupt(this);
2134 }
2135
2136 // External suspension mechanism.
2137 //
2138 // Tell the VM to suspend a thread when ever it knows that it does not hold on
2139 // to any VM_locks and it is at a transition
2140 // Self-suspension will happen on the transition out of the vm.
2141 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
2142 //
2143 // Guarantees on return:
2144 // + Target thread will not execute any new bytecode (that's why we need to
2145 // force a safepoint)
2146 // + Target thread will not enter any new monitors
2147 //
2148 void JavaThread::java_suspend() {
2149 { MutexLocker mu(Threads_lock);
2150 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
2151 return;
2152 }
2153 }
2154
2155 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2156 if (!is_external_suspend()) {
2157 // a racing resume has cancelled us; bail out now
2158 return;
2159 }
2160
2161 // suspend is done
2162 uint32_t debug_bits = 0;
2163 // Warning: is_ext_suspend_completed() may temporarily drop the
2164 // SR_lock to allow the thread to reach a stable thread state if
2165 // it is currently in a transient thread state.
2166 if (is_ext_suspend_completed(false /* !called_by_wait */,
2167 SuspendRetryDelay, &debug_bits) ) {
2168 return;
2169 }
2170 }
2171
2172 VM_ForceSafepoint vm_suspend;
2173 VMThread::execute(&vm_suspend);
2174 }
2175
2176 // Part II of external suspension.
2177 // A JavaThread self suspends when it detects a pending external suspend
2178 // request. This is usually on transitions. It is also done in places
2179 // where continuing to the next transition would surprise the caller,
2180 // e.g., monitor entry.
2181 //
2182 // Returns the number of times that the thread self-suspended.
2183 //
2184 // Note: DO NOT call java_suspend_self() when you just want to block current
2185 // thread. java_suspend_self() is the second stage of cooperative
2186 // suspension for external suspend requests and should only be used
2187 // to complete an external suspend request.
2188 //
2189 int JavaThread::java_suspend_self() {
2190 int ret = 0;
2191
2192 // we are in the process of exiting so don't suspend
2193 if (is_exiting()) {
2194 clear_external_suspend();
2195 return ret;
2196 }
2197
2198 assert(_anchor.walkable() ||
2199 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
2200 "must have walkable stack");
2201
2202 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2203
2204 assert(!this->is_ext_suspended(),
2205 "a thread trying to self-suspend should not already be suspended");
2206
2207 if (this->is_suspend_equivalent()) {
2208 // If we are self-suspending as a result of the lifting of a
2209 // suspend equivalent condition, then the suspend_equivalent
2210 // flag is not cleared until we set the ext_suspended flag so
2211 // that wait_for_ext_suspend_completion() returns consistent
2212 // results.
2213 this->clear_suspend_equivalent();
2214 }
2215
2216 // A racing resume may have cancelled us before we grabbed SR_lock
2217 // above. Or another external suspend request could be waiting for us
2218 // by the time we return from SR_lock()->wait(). The thread
2219 // that requested the suspension may already be trying to walk our
2220 // stack and if we return now, we can change the stack out from under
2221 // it. This would be a "bad thing (TM)" and cause the stack walker
2222 // to crash. We stay self-suspended until there are no more pending
2223 // external suspend requests.
2224 while (is_external_suspend()) {
2225 ret++;
2226 this->set_ext_suspended();
2227
2228 // _ext_suspended flag is cleared by java_resume()
2229 while (is_ext_suspended()) {
2230 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2231 }
2232 }
2233
2234 return ret;
2235 }
2236
2237 #ifdef ASSERT
2238 // verify the JavaThread has not yet been published in the Threads::list, and
2239 // hence doesn't need protection from concurrent access at this stage
2240 void JavaThread::verify_not_published() {
2241 if (!Threads_lock->owned_by_self()) {
2242 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2243 assert( !Threads::includes(this),
2244 "java thread shouldn't have been published yet!");
2245 }
2246 else {
2247 assert( !Threads::includes(this),
2248 "java thread shouldn't have been published yet!");
2249 }
2250 }
2251 #endif
2252
2253 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2254 // progress or when _suspend_flags is non-zero.
2255 // Current thread needs to self-suspend if there is a suspend request and/or
2256 // block if a safepoint is in progress.
2257 // Async exception ISN'T checked.
2258 // Note only the ThreadInVMfromNative transition can call this function
2259 // directly and when thread state is _thread_in_native_trans
2260 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2261 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2262
2263 JavaThread *curJT = JavaThread::current();
2264 bool do_self_suspend = thread->is_external_suspend();
2265
2266 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2267
2268 // If JNIEnv proxies are allowed, don't self-suspend if the target
2269 // thread is not the current thread. In older versions of jdbx, jdbx
2270 // threads could call into the VM with another thread's JNIEnv so we
2271 // can be here operating on behalf of a suspended thread (4432884).
2272 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2273 JavaThreadState state = thread->thread_state();
2274
2275 // We mark this thread_blocked state as a suspend-equivalent so
2276 // that a caller to is_ext_suspend_completed() won't be confused.
2277 // The suspend-equivalent state is cleared by java_suspend_self().
2278 thread->set_suspend_equivalent();
2279
2280 // If the safepoint code sees the _thread_in_native_trans state, it will
2281 // wait until the thread changes to other thread state. There is no
2282 // guarantee on how soon we can obtain the SR_lock and complete the
2283 // self-suspend request. It would be a bad idea to let safepoint wait for
2284 // too long. Temporarily change the state to _thread_blocked to
2285 // let the VM thread know that this thread is ready for GC. The problem
2286 // of changing thread state is that safepoint could happen just after
2287 // java_suspend_self() returns after being resumed, and VM thread will
2288 // see the _thread_blocked state. We must check for safepoint
2289 // after restoring the state and make sure we won't leave while a safepoint
2290 // is in progress.
2291 thread->set_thread_state(_thread_blocked);
2292 thread->java_suspend_self();
2293 thread->set_thread_state(state);
2294 // Make sure new state is seen by VM thread
2295 if (os::is_MP()) {
2296 if (UseMembar) {
2297 // Force a fence between the write above and read below
2298 OrderAccess::fence();
2299 } else {
2300 // Must use this rather than serialization page in particular on Windows
2301 InterfaceSupport::serialize_memory(thread);
2302 }
2303 }
2304 }
2305
2306 if (SafepointSynchronize::do_call_back()) {
2307 // If we are safepointing, then block the caller which may not be
2308 // the same as the target thread (see above).
2309 SafepointSynchronize::block(curJT);
2310 }
2311
2312 if (thread->is_deopt_suspend()) {
2313 thread->clear_deopt_suspend();
2314 RegisterMap map(thread, false);
2315 frame f = thread->last_frame();
2316 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2317 f = f.sender(&map);
2318 }
2319 if (f.id() == thread->must_deopt_id()) {
2320 thread->clear_must_deopt_id();
2321 f.deoptimize(thread);
2322 } else {
2323 fatal("missed deoptimization!");
2324 }
2325 }
2326 }
2327
2328 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2329 // progress or when _suspend_flags is non-zero.
2330 // Current thread needs to self-suspend if there is a suspend request and/or
2331 // block if a safepoint is in progress.
2332 // Also check for pending async exception (not including unsafe access error).
2333 // Note only the native==>VM/Java barriers can call this function and when
2334 // thread state is _thread_in_native_trans.
2335 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2336 check_safepoint_and_suspend_for_native_trans(thread);
2337
2338 if (thread->has_async_exception()) {
2339 // We are in _thread_in_native_trans state, don't handle unsafe
2340 // access error since that may block.
2341 thread->check_and_handle_async_exceptions(false);
2342 }
2343 }
2344
2345 // This is a variant of the normal
2346 // check_special_condition_for_native_trans with slightly different
2347 // semantics for use by critical native wrappers. It does all the
2348 // normal checks but also performs the transition back into
2349 // thread_in_Java state. This is required so that critical natives
2350 // can potentially block and perform a GC if they are the last thread
2351 // exiting the GC_locker.
2352 void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) {
2353 check_special_condition_for_native_trans(thread);
2354
2355 // Finish the transition
2356 thread->set_thread_state(_thread_in_Java);
2357
2358 if (thread->do_critical_native_unlock()) {
2359 ThreadInVMfromJavaNoAsyncException tiv(thread);
2360 GC_locker::unlock_critical(thread);
2361 thread->clear_critical_native_unlock();
2362 }
2363 }
2364
2365 // We need to guarantee the Threads_lock here, since resumes are not
2366 // allowed during safepoint synchronization
2367 // Can only resume from an external suspension
2368 void JavaThread::java_resume() {
2369 assert_locked_or_safepoint(Threads_lock);
2370
2371 // Sanity check: thread is gone, has started exiting or the thread
2372 // was not externally suspended.
2373 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2374 return;
2375 }
2376
2377 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2378
2379 clear_external_suspend();
2380
2381 if (is_ext_suspended()) {
2382 clear_ext_suspended();
2383 SR_lock()->notify_all();
2384 }
2385 }
2386
2387 void JavaThread::create_stack_guard_pages() {
2388 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2389 address low_addr = stack_base() - stack_size();
2390 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2391
2392 int allocate = os::allocate_stack_guard_pages();
2393 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2394
2395 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
2396 warning("Attempt to allocate stack guard pages failed.");
2397 return;
2398 }
2399
2400 if (os::guard_memory((char *) low_addr, len)) {
2401 _stack_guard_state = stack_guard_enabled;
2402 } else {
2403 warning("Attempt to protect stack guard pages failed.");
2404 if (os::uncommit_memory((char *) low_addr, len)) {
2405 warning("Attempt to deallocate stack guard pages failed.");
2406 }
2407 }
2408 }
2409
2410 void JavaThread::remove_stack_guard_pages() {
2411 if (_stack_guard_state == stack_guard_unused) return;
2412 address low_addr = stack_base() - stack_size();
2413 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2414
2415 if (os::allocate_stack_guard_pages()) {
2416 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2417 _stack_guard_state = stack_guard_unused;
2418 } else {
2419 warning("Attempt to deallocate stack guard pages failed.");
2420 }
2421 } else {
2422 if (_stack_guard_state == stack_guard_unused) return;
2423 if (os::unguard_memory((char *) low_addr, len)) {
2424 _stack_guard_state = stack_guard_unused;
2425 } else {
2426 warning("Attempt to unprotect stack guard pages failed.");
2427 }
2428 }
2429 }
2430
2431 void JavaThread::enable_stack_yellow_zone() {
2432 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2433 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2434
2435 // The base notation is from the stacks point of view, growing downward.
2436 // We need to adjust it to work correctly with guard_memory()
2437 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2438
2439 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2440 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2441
2442 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2443 _stack_guard_state = stack_guard_enabled;
2444 } else {
2445 warning("Attempt to guard stack yellow zone failed.");
2446 }
2447 enable_register_stack_guard();
2448 }
2449
2450 void JavaThread::disable_stack_yellow_zone() {
2451 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2452 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2453
2454 // Simply return if called for a thread that does not use guard pages.
2455 if (_stack_guard_state == stack_guard_unused) return;
2456
2457 // The base notation is from the stacks point of view, growing downward.
2458 // We need to adjust it to work correctly with guard_memory()
2459 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2460
2461 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2462 _stack_guard_state = stack_guard_yellow_disabled;
2463 } else {
2464 warning("Attempt to unguard stack yellow zone failed.");
2465 }
2466 disable_register_stack_guard();
2467 }
2468
2469 void JavaThread::enable_stack_red_zone() {
2470 // The base notation is from the stacks point of view, growing downward.
2471 // We need to adjust it to work correctly with guard_memory()
2472 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2473 address base = stack_red_zone_base() - stack_red_zone_size();
2474
2475 guarantee(base < stack_base(),"Error calculating stack red zone");
2476 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2477
2478 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2479 warning("Attempt to guard stack red zone failed.");
2480 }
2481 }
2482
2483 void JavaThread::disable_stack_red_zone() {
2484 // The base notation is from the stacks point of view, growing downward.
2485 // We need to adjust it to work correctly with guard_memory()
2486 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2487 address base = stack_red_zone_base() - stack_red_zone_size();
2488 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2489 warning("Attempt to unguard stack red zone failed.");
2490 }
2491 }
2492
2493 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2494 // ignore is there is no stack
2495 if (!has_last_Java_frame()) return;
2496 // traverse the stack frames. Starts from top frame.
2497 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2498 frame* fr = fst.current();
2499 f(fr, fst.register_map());
2500 }
2501 }
2502
2503
2504 #ifndef PRODUCT
2505 // Deoptimization
2506 // Function for testing deoptimization
2507 void JavaThread::deoptimize() {
2508 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2509 StackFrameStream fst(this, UseBiasedLocking);
2510 bool deopt = false; // Dump stack only if a deopt actually happens.
2511 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2512 // Iterate over all frames in the thread and deoptimize
2513 for(; !fst.is_done(); fst.next()) {
2514 if(fst.current()->can_be_deoptimized()) {
2515
2516 if (only_at) {
2517 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2518 // consists of comma or carriage return separated numbers so
2519 // search for the current bci in that string.
2520 address pc = fst.current()->pc();
2521 nmethod* nm = (nmethod*) fst.current()->cb();
2522 ScopeDesc* sd = nm->scope_desc_at( pc);
2523 char buffer[8];
2524 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2525 size_t len = strlen(buffer);
2526 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2527 while (found != NULL) {
2528 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2529 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2530 // Check that the bci found is bracketed by terminators.
2531 break;
2532 }
2533 found = strstr(found + 1, buffer);
2534 }
2535 if (!found) {
2536 continue;
2537 }
2538 }
2539
2540 if (DebugDeoptimization && !deopt) {
2541 deopt = true; // One-time only print before deopt
2542 tty->print_cr("[BEFORE Deoptimization]");
2543 trace_frames();
2544 trace_stack();
2545 }
2546 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2547 }
2548 }
2549
2550 if (DebugDeoptimization && deopt) {
2551 tty->print_cr("[AFTER Deoptimization]");
2552 trace_frames();
2553 }
2554 }
2555
2556
2557 // Make zombies
2558 void JavaThread::make_zombies() {
2559 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2560 if (fst.current()->can_be_deoptimized()) {
2561 // it is a Java nmethod
2562 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2563 nm->make_not_entrant();
2564 }
2565 }
2566 }
2567 #endif // PRODUCT
2568
2569
2570 void JavaThread::deoptimized_wrt_marked_nmethods() {
2571 if (!has_last_Java_frame()) return;
2572 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2573 StackFrameStream fst(this, UseBiasedLocking);
2574 for(; !fst.is_done(); fst.next()) {
2575 if (fst.current()->should_be_deoptimized()) {
2576 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2577 }
2578 }
2579 }
2580
2581
2582 // GC support
2583 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2584
2585 void JavaThread::gc_epilogue() {
2586 frames_do(frame_gc_epilogue);
2587 }
2588
2589
2590 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2591
2592 void JavaThread::gc_prologue() {
2593 frames_do(frame_gc_prologue);
2594 }
2595
2596 // If the caller is a NamedThread, then remember, in the current scope,
2597 // the given JavaThread in its _processed_thread field.
2598 class RememberProcessedThread: public StackObj {
2599 NamedThread* _cur_thr;
2600 public:
2601 RememberProcessedThread(JavaThread* jthr) {
2602 Thread* thread = Thread::current();
2603 if (thread->is_Named_thread()) {
2604 _cur_thr = (NamedThread *)thread;
2605 _cur_thr->set_processed_thread(jthr);
2606 } else {
2607 _cur_thr = NULL;
2608 }
2609 }
2610
2611 ~RememberProcessedThread() {
2612 if (_cur_thr) {
2613 _cur_thr->set_processed_thread(NULL);
2614 }
2615 }
2616 };
2617
2618 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2619 // Verify that the deferred card marks have been flushed.
2620 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2621
2622 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2623 // since there may be more than one thread using each ThreadProfiler.
2624
2625 // Traverse the GCHandles
2626 Thread::oops_do(f, cf);
2627
2628 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2629 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2630
2631 if (has_last_Java_frame()) {
2632 // Record JavaThread to GC thread
2633 RememberProcessedThread rpt(this);
2634
2635 // Traverse the privileged stack
2636 if (_privileged_stack_top != NULL) {
2637 _privileged_stack_top->oops_do(f);
2638 }
2639
2640 // traverse the registered growable array
2641 if (_array_for_gc != NULL) {
2642 for (int index = 0; index < _array_for_gc->length(); index++) {
2643 f->do_oop(_array_for_gc->adr_at(index));
2644 }
2645 }
2646
2647 // Traverse the monitor chunks
2648 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2649 chunk->oops_do(f);
2650 }
2651
2652 // Traverse the execution stack
2653 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2654 fst.current()->oops_do(f, cf, fst.register_map());
2655 }
2656 }
2657
2658 // callee_target is never live across a gc point so NULL it here should
2659 // it still contain a methdOop.
2660
2661 set_callee_target(NULL);
2662
2663 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2664 // If we have deferred set_locals there might be oops waiting to be
2665 // written
2666 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2667 if (list != NULL) {
2668 for (int i = 0; i < list->length(); i++) {
2669 list->at(i)->oops_do(f);
2670 }
2671 }
2672
2673 // Traverse instance variables at the end since the GC may be moving things
2674 // around using this function
2675 f->do_oop((oop*) &_threadObj);
2676 f->do_oop((oop*) &_vm_result);
2677 f->do_oop((oop*) &_exception_oop);
2678 f->do_oop((oop*) &_pending_async_exception);
2679
2680 if (jvmti_thread_state() != NULL) {
2681 jvmti_thread_state()->oops_do(f);
2682 }
2683 }
2684
2685 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2686 Thread::nmethods_do(cf); // (super method is a no-op)
2687
2688 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2689 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2690
2691 if (has_last_Java_frame()) {
2692 // Traverse the execution stack
2693 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2694 fst.current()->nmethods_do(cf);
2695 }
2696 }
2697 }
2698
2699 void JavaThread::metadata_do(void f(Metadata*)) {
2700 Thread::metadata_do(f);
2701 if (has_last_Java_frame()) {
2702 // Traverse the execution stack to call f() on the methods in the stack
2703 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2704 fst.current()->metadata_do(f);
2705 }
2706 } else if (is_Compiler_thread()) {
2707 // need to walk ciMetadata in current compile tasks to keep alive.
2708 CompilerThread* ct = (CompilerThread*)this;
2709 if (ct->env() != NULL) {
2710 ct->env()->metadata_do(f);
2711 }
2712 }
2713 }
2714
2715 // Printing
2716 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2717 switch (_thread_state) {
2718 case _thread_uninitialized: return "_thread_uninitialized";
2719 case _thread_new: return "_thread_new";
2720 case _thread_new_trans: return "_thread_new_trans";
2721 case _thread_in_native: return "_thread_in_native";
2722 case _thread_in_native_trans: return "_thread_in_native_trans";
2723 case _thread_in_vm: return "_thread_in_vm";
2724 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2725 case _thread_in_Java: return "_thread_in_Java";
2726 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2727 case _thread_blocked: return "_thread_blocked";
2728 case _thread_blocked_trans: return "_thread_blocked_trans";
2729 default: return "unknown thread state";
2730 }
2731 }
2732
2733 #ifndef PRODUCT
2734 void JavaThread::print_thread_state_on(outputStream *st) const {
2735 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2736 };
2737 void JavaThread::print_thread_state() const {
2738 print_thread_state_on(tty);
2739 };
2740 #endif // PRODUCT
2741
2742 // Called by Threads::print() for VM_PrintThreads operation
2743 void JavaThread::print_on(outputStream *st) const {
2744 st->print("\"%s\" ", get_thread_name());
2745 oop thread_oop = threadObj();
2746 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2747 Thread::print_on(st);
2748 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2749 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2750 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2751 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2752 }
2753 #ifndef PRODUCT
2754 print_thread_state_on(st);
2755 _safepoint_state->print_on(st);
2756 #endif // PRODUCT
2757 }
2758
2759 // Called by fatal error handler. The difference between this and
2760 // JavaThread::print() is that we can't grab lock or allocate memory.
2761 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2762 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2763 oop thread_obj = threadObj();
2764 if (thread_obj != NULL) {
2765 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2766 }
2767 st->print(" [");
2768 st->print("%s", _get_thread_state_name(_thread_state));
2769 if (osthread()) {
2770 st->print(", id=%d", osthread()->thread_id());
2771 }
2772 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2773 _stack_base - _stack_size, _stack_base);
2774 st->print("]");
2775 return;
2776 }
2777
2778 // Verification
2779
2780 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2781
2782 void JavaThread::verify() {
2783 // Verify oops in the thread.
2784 oops_do(&VerifyOopClosure::verify_oop, NULL);
2785
2786 // Verify the stack frames.
2787 frames_do(frame_verify);
2788 }
2789
2790 // CR 6300358 (sub-CR 2137150)
2791 // Most callers of this method assume that it can't return NULL but a
2792 // thread may not have a name whilst it is in the process of attaching to
2793 // the VM - see CR 6412693, and there are places where a JavaThread can be
2794 // seen prior to having it's threadObj set (eg JNI attaching threads and
2795 // if vm exit occurs during initialization). These cases can all be accounted
2796 // for such that this method never returns NULL.
2797 const char* JavaThread::get_thread_name() const {
2798 #ifdef ASSERT
2799 // early safepoints can hit while current thread does not yet have TLS
2800 if (!SafepointSynchronize::is_at_safepoint()) {
2801 Thread *cur = Thread::current();
2802 if (!(cur->is_Java_thread() && cur == this)) {
2803 // Current JavaThreads are allowed to get their own name without
2804 // the Threads_lock.
2805 assert_locked_or_safepoint(Threads_lock);
2806 }
2807 }
2808 #endif // ASSERT
2809 return get_thread_name_string();
2810 }
2811
2812 // Returns a non-NULL representation of this thread's name, or a suitable
2813 // descriptive string if there is no set name
2814 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2815 const char* name_str;
2816 oop thread_obj = threadObj();
2817 if (thread_obj != NULL) {
2818 typeArrayOop name = java_lang_Thread::name(thread_obj);
2819 if (name != NULL) {
2820 if (buf == NULL) {
2821 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2822 }
2823 else {
2824 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2825 }
2826 }
2827 else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2828 name_str = "<no-name - thread is attaching>";
2829 }
2830 else {
2831 name_str = Thread::name();
2832 }
2833 }
2834 else {
2835 name_str = Thread::name();
2836 }
2837 assert(name_str != NULL, "unexpected NULL thread name");
2838 return name_str;
2839 }
2840
2841
2842 const char* JavaThread::get_threadgroup_name() const {
2843 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2844 oop thread_obj = threadObj();
2845 if (thread_obj != NULL) {
2846 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2847 if (thread_group != NULL) {
2848 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2849 // ThreadGroup.name can be null
2850 if (name != NULL) {
2851 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2852 return str;
2853 }
2854 }
2855 }
2856 return NULL;
2857 }
2858
2859 const char* JavaThread::get_parent_name() const {
2860 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2861 oop thread_obj = threadObj();
2862 if (thread_obj != NULL) {
2863 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2864 if (thread_group != NULL) {
2865 oop parent = java_lang_ThreadGroup::parent(thread_group);
2866 if (parent != NULL) {
2867 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2868 // ThreadGroup.name can be null
2869 if (name != NULL) {
2870 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2871 return str;
2872 }
2873 }
2874 }
2875 }
2876 return NULL;
2877 }
2878
2879 ThreadPriority JavaThread::java_priority() const {
2880 oop thr_oop = threadObj();
2881 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2882 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2883 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2884 return priority;
2885 }
2886
2887 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2888
2889 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2890 // Link Java Thread object <-> C++ Thread
2891
2892 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2893 // and put it into a new Handle. The Handle "thread_oop" can then
2894 // be used to pass the C++ thread object to other methods.
2895
2896 // Set the Java level thread object (jthread) field of the
2897 // new thread (a JavaThread *) to C++ thread object using the
2898 // "thread_oop" handle.
2899
2900 // Set the thread field (a JavaThread *) of the
2901 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2902
2903 Handle thread_oop(Thread::current(),
2904 JNIHandles::resolve_non_null(jni_thread));
2905 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
2906 "must be initialized");
2907 set_threadObj(thread_oop());
2908 java_lang_Thread::set_thread(thread_oop(), this);
2909
2910 if (prio == NoPriority) {
2911 prio = java_lang_Thread::priority(thread_oop());
2912 assert(prio != NoPriority, "A valid priority should be present");
2913 }
2914
2915 // Push the Java priority down to the native thread; needs Threads_lock
2916 Thread::set_priority(this, prio);
2917
2918 // Add the new thread to the Threads list and set it in motion.
2919 // We must have threads lock in order to call Threads::add.
2920 // It is crucial that we do not block before the thread is
2921 // added to the Threads list for if a GC happens, then the java_thread oop
2922 // will not be visited by GC.
2923 Threads::add(this);
2924 }
2925
2926 oop JavaThread::current_park_blocker() {
2927 // Support for JSR-166 locks
2928 oop thread_oop = threadObj();
2929 if (thread_oop != NULL &&
2930 JDK_Version::current().supports_thread_park_blocker()) {
2931 return java_lang_Thread::park_blocker(thread_oop);
2932 }
2933 return NULL;
2934 }
2935
2936
2937 void JavaThread::print_stack_on(outputStream* st) {
2938 if (!has_last_Java_frame()) return;
2939 ResourceMark rm;
2940 HandleMark hm;
2941
2942 RegisterMap reg_map(this);
2943 vframe* start_vf = last_java_vframe(®_map);
2944 int count = 0;
2945 for (vframe* f = start_vf; f; f = f->sender() ) {
2946 if (f->is_java_frame()) {
2947 javaVFrame* jvf = javaVFrame::cast(f);
2948 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2949
2950 // Print out lock information
2951 if (JavaMonitorsInStackTrace) {
2952 jvf->print_lock_info_on(st, count);
2953 }
2954 } else {
2955 // Ignore non-Java frames
2956 }
2957
2958 // Bail-out case for too deep stacks
2959 count++;
2960 if (MaxJavaStackTraceDepth == count) return;
2961 }
2962 }
2963
2964
2965 // JVMTI PopFrame support
2966 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2967 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2968 if (in_bytes(size_in_bytes) != 0) {
2969 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
2970 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2971 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2972 }
2973 }
2974
2975 void* JavaThread::popframe_preserved_args() {
2976 return _popframe_preserved_args;
2977 }
2978
2979 ByteSize JavaThread::popframe_preserved_args_size() {
2980 return in_ByteSize(_popframe_preserved_args_size);
2981 }
2982
2983 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2984 int sz = in_bytes(popframe_preserved_args_size());
2985 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2986 return in_WordSize(sz / wordSize);
2987 }
2988
2989 void JavaThread::popframe_free_preserved_args() {
2990 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2991 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args, mtThread);
2992 _popframe_preserved_args = NULL;
2993 _popframe_preserved_args_size = 0;
2994 }
2995
2996 #ifndef PRODUCT
2997
2998 void JavaThread::trace_frames() {
2999 tty->print_cr("[Describe stack]");
3000 int frame_no = 1;
3001 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
3002 tty->print(" %d. ", frame_no++);
3003 fst.current()->print_value_on(tty,this);
3004 tty->cr();
3005 }
3006 }
3007
3008 class PrintAndVerifyOopClosure: public OopClosure {
3009 protected:
3010 template <class T> inline void do_oop_work(T* p) {
3011 oop obj = oopDesc::load_decode_heap_oop(p);
3012 if (obj == NULL) return;
3013 tty->print(INTPTR_FORMAT ": ", p);
3014 if (obj->is_oop_or_null()) {
3015 if (obj->is_objArray()) {
3016 tty->print_cr("valid objArray: " INTPTR_FORMAT, (oopDesc*) obj);
3017 } else {
3018 obj->print();
3019 }
3020 } else {
3021 tty->print_cr("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj);
3022 }
3023 tty->cr();
3024 }
3025 public:
3026 virtual void do_oop(oop* p) { do_oop_work(p); }
3027 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
3028 };
3029
3030
3031 static void oops_print(frame* f, const RegisterMap *map) {
3032 PrintAndVerifyOopClosure print;
3033 f->print_value();
3034 f->oops_do(&print, NULL, (RegisterMap*)map);
3035 }
3036
3037 // Print our all the locations that contain oops and whether they are
3038 // valid or not. This useful when trying to find the oldest frame
3039 // where an oop has gone bad since the frame walk is from youngest to
3040 // oldest.
3041 void JavaThread::trace_oops() {
3042 tty->print_cr("[Trace oops]");
3043 frames_do(oops_print);
3044 }
3045
3046
3047 #ifdef ASSERT
3048 // Print or validate the layout of stack frames
3049 void JavaThread::print_frame_layout(int depth, bool validate_only) {
3050 ResourceMark rm;
3051 PRESERVE_EXCEPTION_MARK;
3052 FrameValues values;
3053 int frame_no = 0;
3054 for(StackFrameStream fst(this, false); !fst.is_done(); fst.next()) {
3055 fst.current()->describe(values, ++frame_no);
3056 if (depth == frame_no) break;
3057 }
3058 if (validate_only) {
3059 values.validate();
3060 } else {
3061 tty->print_cr("[Describe stack layout]");
3062 values.print(this);
3063 }
3064 }
3065 #endif
3066
3067 void JavaThread::trace_stack_from(vframe* start_vf) {
3068 ResourceMark rm;
3069 int vframe_no = 1;
3070 for (vframe* f = start_vf; f; f = f->sender() ) {
3071 if (f->is_java_frame()) {
3072 javaVFrame::cast(f)->print_activation(vframe_no++);
3073 } else {
3074 f->print();
3075 }
3076 if (vframe_no > StackPrintLimit) {
3077 tty->print_cr("...<more frames>...");
3078 return;
3079 }
3080 }
3081 }
3082
3083
3084 void JavaThread::trace_stack() {
3085 if (!has_last_Java_frame()) return;
3086 ResourceMark rm;
3087 HandleMark hm;
3088 RegisterMap reg_map(this);
3089 trace_stack_from(last_java_vframe(®_map));
3090 }
3091
3092
3093 #endif // PRODUCT
3094
3095
3096 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
3097 assert(reg_map != NULL, "a map must be given");
3098 frame f = last_frame();
3099 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
3100 if (vf->is_java_frame()) return javaVFrame::cast(vf);
3101 }
3102 return NULL;
3103 }
3104
3105
3106 Klass* JavaThread::security_get_caller_class(int depth) {
3107 vframeStream vfst(this);
3108 vfst.security_get_caller_frame(depth);
3109 if (!vfst.at_end()) {
3110 return vfst.method()->method_holder();
3111 }
3112 return NULL;
3113 }
3114
3115 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
3116 assert(thread->is_Compiler_thread(), "must be compiler thread");
3117 CompileBroker::compiler_thread_loop();
3118 }
3119
3120 // Create a CompilerThread
3121 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
3122 : JavaThread(&compiler_thread_entry) {
3123 _env = NULL;
3124 _log = NULL;
3125 _task = NULL;
3126 _queue = queue;
3127 _counters = counters;
3128 _buffer_blob = NULL;
3129 _scanned_nmethod = NULL;
3130
3131 #ifndef PRODUCT
3132 _ideal_graph_printer = NULL;
3133 #endif
3134 }
3135
3136 void CompilerThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3137 JavaThread::oops_do(f, cf);
3138 if (_scanned_nmethod != NULL && cf != NULL) {
3139 // Safepoints can occur when the sweeper is scanning an nmethod so
3140 // process it here to make sure it isn't unloaded in the middle of
3141 // a scan.
3142 cf->do_code_blob(_scanned_nmethod);
3143 }
3144 }
3145
3146 // ======= Threads ========
3147
3148 // The Threads class links together all active threads, and provides
3149 // operations over all threads. It is protected by its own Mutex
3150 // lock, which is also used in other contexts to protect thread
3151 // operations from having the thread being operated on from exiting
3152 // and going away unexpectedly (e.g., safepoint synchronization)
3153
3154 JavaThread* Threads::_thread_list = NULL;
3155 int Threads::_number_of_threads = 0;
3156 int Threads::_number_of_non_daemon_threads = 0;
3157 int Threads::_return_code = 0;
3158 size_t JavaThread::_stack_size_at_create = 0;
3159 #ifdef ASSERT
3160 bool Threads::_vm_complete = false;
3161 #endif
3162
3163 // All JavaThreads
3164 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
3165
3166 void os_stream();
3167
3168 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
3169 void Threads::threads_do(ThreadClosure* tc) {
3170 assert_locked_or_safepoint(Threads_lock);
3171 // ALL_JAVA_THREADS iterates through all JavaThreads
3172 ALL_JAVA_THREADS(p) {
3173 tc->do_thread(p);
3174 }
3175 // Someday we could have a table or list of all non-JavaThreads.
3176 // For now, just manually iterate through them.
3177 tc->do_thread(VMThread::vm_thread());
3178 Universe::heap()->gc_threads_do(tc);
3179 WatcherThread *wt = WatcherThread::watcher_thread();
3180 // Strictly speaking, the following NULL check isn't sufficient to make sure
3181 // the data for WatcherThread is still valid upon being examined. However,
3182 // considering that WatchThread terminates when the VM is on the way to
3183 // exit at safepoint, the chance of the above is extremely small. The right
3184 // way to prevent termination of WatcherThread would be to acquire
3185 // Terminator_lock, but we can't do that without violating the lock rank
3186 // checking in some cases.
3187 if (wt != NULL)
3188 tc->do_thread(wt);
3189
3190 // If CompilerThreads ever become non-JavaThreads, add them here
3191 }
3192
3193 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
3194
3195 extern void JDK_Version_init();
3196
3197 // Check version
3198 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
3199
3200 // Initialize the output stream module
3201 ostream_init();
3202
3203 // Process java launcher properties.
3204 Arguments::process_sun_java_launcher_properties(args);
3205
3206 // Initialize the os module before using TLS
3207 os::init();
3208
3209 // Initialize system properties.
3210 Arguments::init_system_properties();
3211
3212 // So that JDK version can be used as a discrimintor when parsing arguments
3213 JDK_Version_init();
3214
3215 // Update/Initialize System properties after JDK version number is known
3216 Arguments::init_version_specific_system_properties();
3217
3218 // Parse arguments
3219 jint parse_result = Arguments::parse(args);
3220 if (parse_result != JNI_OK) return parse_result;
3221
3222 if (PauseAtStartup) {
3223 os::pause();
3224 }
3225
3226 #ifndef USDT2
3227 HS_DTRACE_PROBE(hotspot, vm__init__begin);
3228 #else /* USDT2 */
3229 HOTSPOT_VM_INIT_BEGIN();
3230 #endif /* USDT2 */
3231
3232 // Record VM creation timing statistics
3233 TraceVmCreationTime create_vm_timer;
3234 create_vm_timer.start();
3235
3236 // Timing (must come after argument parsing)
3237 TraceTime timer("Create VM", TraceStartupTime);
3238
3239 // Initialize the os module after parsing the args
3240 jint os_init_2_result = os::init_2();
3241 if (os_init_2_result != JNI_OK) return os_init_2_result;
3242
3243 // intialize TLS
3244 ThreadLocalStorage::init();
3245
3246 // Bootstrap native memory tracking, so it can start recording memory
3247 // activities before worker thread is started. This is the first phase
3248 // of bootstrapping, VM is currently running in single-thread mode.
3249 MemTracker::bootstrap_single_thread();
3250
3251 // Initialize output stream logging
3252 ostream_init_log();
3253
3254 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
3255 // Must be before create_vm_init_agents()
3256 if (Arguments::init_libraries_at_startup()) {
3257 convert_vm_init_libraries_to_agents();
3258 }
3259
3260 // Launch -agentlib/-agentpath and converted -Xrun agents
3261 if (Arguments::init_agents_at_startup()) {
3262 create_vm_init_agents();
3263 }
3264
3265 // Initialize Threads state
3266 _thread_list = NULL;
3267 _number_of_threads = 0;
3268 _number_of_non_daemon_threads = 0;
3269
3270 // Initialize global data structures and create system classes in heap
3271 vm_init_globals();
3272
3273 // Attach the main thread to this os thread
3274 JavaThread* main_thread = new JavaThread();
3275 main_thread->set_thread_state(_thread_in_vm);
3276 // must do this before set_active_handles and initialize_thread_local_storage
3277 // Note: on solaris initialize_thread_local_storage() will (indirectly)
3278 // change the stack size recorded here to one based on the java thread
3279 // stacksize. This adjusted size is what is used to figure the placement
3280 // of the guard pages.
3281 main_thread->record_stack_base_and_size();
3282 main_thread->initialize_thread_local_storage();
3283
3284 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
3285
3286 if (!main_thread->set_as_starting_thread()) {
3287 vm_shutdown_during_initialization(
3288 "Failed necessary internal allocation. Out of swap space");
3289 delete main_thread;
3290 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3291 return JNI_ENOMEM;
3292 }
3293
3294 // Enable guard page *after* os::create_main_thread(), otherwise it would
3295 // crash Linux VM, see notes in os_linux.cpp.
3296 main_thread->create_stack_guard_pages();
3297
3298 // Initialize Java-Level synchronization subsystem
3299 ObjectMonitor::Initialize() ;
3300
3301 // Second phase of bootstrapping, VM is about entering multi-thread mode
3302 MemTracker::bootstrap_multi_thread();
3303
3304 // Initialize global modules
3305 jint status = init_globals();
3306 if (status != JNI_OK) {
3307 delete main_thread;
3308 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3309 return status;
3310 }
3311
3312 // Should be done after the heap is fully created
3313 main_thread->cache_global_variables();
3314
3315 HandleMark hm;
3316
3317 { MutexLocker mu(Threads_lock);
3318 Threads::add(main_thread);
3319 }
3320
3321 // Any JVMTI raw monitors entered in onload will transition into
3322 // real raw monitor. VM is setup enough here for raw monitor enter.
3323 JvmtiExport::transition_pending_onload_raw_monitors();
3324
3325 if (VerifyBeforeGC &&
3326 Universe::heap()->total_collections() >= VerifyGCStartAt) {
3327 Universe::heap()->prepare_for_verify();
3328 Universe::verify(); // make sure we're starting with a clean slate
3329 }
3330
3331 // Fully start NMT
3332 MemTracker::start();
3333
3334 // Create the VMThread
3335 { TraceTime timer("Start VMThread", TraceStartupTime);
3336 VMThread::create();
3337 Thread* vmthread = VMThread::vm_thread();
3338
3339 if (!os::create_thread(vmthread, os::vm_thread))
3340 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
3341
3342 // Wait for the VM thread to become ready, and VMThread::run to initialize
3343 // Monitors can have spurious returns, must always check another state flag
3344 {
3345 MutexLocker ml(Notify_lock);
3346 os::start_thread(vmthread);
3347 while (vmthread->active_handles() == NULL) {
3348 Notify_lock->wait();
3349 }
3350 }
3351 }
3352
3353 assert (Universe::is_fully_initialized(), "not initialized");
3354 EXCEPTION_MARK;
3355
3356 // At this point, the Universe is initialized, but we have not executed
3357 // any byte code. Now is a good time (the only time) to dump out the
3358 // internal state of the JVM for sharing.
3359 if (DumpSharedSpaces) {
3360 MetaspaceShared::preload_and_dump(CHECK_0);
3361 ShouldNotReachHere();
3362 }
3363
3364 // Always call even when there are not JVMTI environments yet, since environments
3365 // may be attached late and JVMTI must track phases of VM execution
3366 JvmtiExport::enter_start_phase();
3367
3368 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3369 JvmtiExport::post_vm_start();
3370
3371 {
3372 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3373
3374 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3375 create_vm_init_libraries();
3376 }
3377
3378 if (InitializeJavaLangString) {
3379 initialize_class(vmSymbols::java_lang_String(), CHECK_0);
3380 } else {
3381 warning("java.lang.String not initialized");
3382 }
3383
3384 if (AggressiveOpts) {
3385 {
3386 // Forcibly initialize java/util/HashMap and mutate the private
3387 // static final "frontCacheEnabled" field before we start creating instances
3388 #ifdef ASSERT
3389 Klass* tmp_k = SystemDictionary::find(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3390 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
3391 #endif
3392 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3393 KlassHandle k = KlassHandle(THREAD, k_o);
3394 guarantee(k.not_null(), "Must find java/util/HashMap");
3395 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3396 ik->initialize(CHECK_0);
3397 fieldDescriptor fd;
3398 // Possible we might not find this field; if so, don't break
3399 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3400 k()->java_mirror()->bool_field_put(fd.offset(), true);
3401 }
3402 }
3403
3404 if (UseStringCache) {
3405 // Forcibly initialize java/lang/StringValue and mutate the private
3406 // static final "stringCacheEnabled" field before we start creating instances
3407 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3408 // Possible that StringValue isn't present: if so, silently don't break
3409 if (k_o != NULL) {
3410 KlassHandle k = KlassHandle(THREAD, k_o);
3411 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3412 ik->initialize(CHECK_0);
3413 fieldDescriptor fd;
3414 // Possible we might not find this field: if so, silently don't break
3415 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3416 k()->java_mirror()->bool_field_put(fd.offset(), true);
3417 }
3418 }
3419 }
3420 }
3421
3422 // Initialize java_lang.System (needed before creating the thread)
3423 if (InitializeJavaLangSystem) {
3424 initialize_class(vmSymbols::java_lang_System(), CHECK_0);
3425 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK_0);
3426 Handle thread_group = create_initial_thread_group(CHECK_0);
3427 Universe::set_main_thread_group(thread_group());
3428 initialize_class(vmSymbols::java_lang_Thread(), CHECK_0);
3429 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3430 main_thread->set_threadObj(thread_object);
3431 // Set thread status to running since main thread has
3432 // been started and running.
3433 java_lang_Thread::set_thread_status(thread_object,
3434 java_lang_Thread::RUNNABLE);
3435
3436 // The VM preresolve methods to these classes. Make sure that get initialized
3437 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK_0);
3438 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK_0);
3439 // The VM creates & returns objects of this class. Make sure it's initialized.
3440 initialize_class(vmSymbols::java_lang_Class(), CHECK_0);
3441 call_initializeSystemClass(CHECK_0);
3442
3443 // get the Java runtime name after java.lang.System is initialized
3444 JDK_Version::set_runtime_name(get_java_runtime_name(THREAD));
3445 } else {
3446 warning("java.lang.System not initialized");
3447 }
3448
3449 // an instance of OutOfMemory exception has been allocated earlier
3450 if (InitializeJavaLangExceptionsErrors) {
3451 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK_0);
3452 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK_0);
3453 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK_0);
3454 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK_0);
3455 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK_0);
3456 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK_0);
3457 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK_0);
3458 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK_0);
3459 } else {
3460 warning("java.lang.OutOfMemoryError has not been initialized");
3461 warning("java.lang.NullPointerException has not been initialized");
3462 warning("java.lang.ClassCastException has not been initialized");
3463 warning("java.lang.ArrayStoreException has not been initialized");
3464 warning("java.lang.ArithmeticException has not been initialized");
3465 warning("java.lang.StackOverflowError has not been initialized");
3466 warning("java.lang.IllegalArgumentException has not been initialized");
3467 }
3468 }
3469
3470 // See : bugid 4211085.
3471 // Background : the static initializer of java.lang.Compiler tries to read
3472 // property"java.compiler" and read & write property "java.vm.info".
3473 // When a security manager is installed through the command line
3474 // option "-Djava.security.manager", the above properties are not
3475 // readable and the static initializer for java.lang.Compiler fails
3476 // resulting in a NoClassDefFoundError. This can happen in any
3477 // user code which calls methods in java.lang.Compiler.
3478 // Hack : the hack is to pre-load and initialize this class, so that only
3479 // system domains are on the stack when the properties are read.
3480 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3481 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3482 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3483 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3484 // Once that is done, we should remove this hack.
3485 initialize_class(vmSymbols::java_lang_Compiler(), CHECK_0);
3486
3487 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3488 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3489 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3490 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3491 // This should also be taken out as soon as 4211383 gets fixed.
3492 reset_vm_info_property(CHECK_0);
3493
3494 quicken_jni_functions();
3495
3496 // Must be run after init_ft which initializes ft_enabled
3497 if (TRACE_INITIALIZE() != JNI_OK) {
3498 vm_exit_during_initialization("Failed to initialize tracing backend");
3499 }
3500
3501 // Set flag that basic initialization has completed. Used by exceptions and various
3502 // debug stuff, that does not work until all basic classes have been initialized.
3503 set_init_completed();
3504
3505 #ifndef USDT2
3506 HS_DTRACE_PROBE(hotspot, vm__init__end);
3507 #else /* USDT2 */
3508 HOTSPOT_VM_INIT_END();
3509 #endif /* USDT2 */
3510
3511 // record VM initialization completion time
3512 Management::record_vm_init_completed();
3513
3514 // Compute system loader. Note that this has to occur after set_init_completed, since
3515 // valid exceptions may be thrown in the process.
3516 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3517 // set_init_completed has just been called, causing exceptions not to be shortcut
3518 // anymore. We call vm_exit_during_initialization directly instead.
3519 SystemDictionary::compute_java_system_loader(THREAD);
3520 if (HAS_PENDING_EXCEPTION) {
3521 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3522 }
3523
3524 #ifndef SERIALGC
3525 // Support for ConcurrentMarkSweep. This should be cleaned up
3526 // and better encapsulated. The ugly nested if test would go away
3527 // once things are properly refactored. XXX YSR
3528 if (UseConcMarkSweepGC || UseG1GC) {
3529 if (UseConcMarkSweepGC) {
3530 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3531 } else {
3532 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3533 }
3534 if (HAS_PENDING_EXCEPTION) {
3535 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3536 }
3537 }
3538 #endif // SERIALGC
3539
3540 // Always call even when there are not JVMTI environments yet, since environments
3541 // may be attached late and JVMTI must track phases of VM execution
3542 JvmtiExport::enter_live_phase();
3543
3544 // Signal Dispatcher needs to be started before VMInit event is posted
3545 os::signal_init();
3546
3547 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3548 if (!DisableAttachMechanism) {
3549 if (StartAttachListener || AttachListener::init_at_startup()) {
3550 AttachListener::init();
3551 }
3552 }
3553
3554 // Launch -Xrun agents
3555 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3556 // back-end can launch with -Xdebug -Xrunjdwp.
3557 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3558 create_vm_init_libraries();
3559 }
3560
3561 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3562 JvmtiExport::post_vm_initialized();
3563
3564 if (!TRACE_START()) {
3565 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3566 }
3567
3568 if (CleanChunkPoolAsync) {
3569 Chunk::start_chunk_pool_cleaner_task();
3570 }
3571
3572 // initialize compiler(s)
3573 CompileBroker::compilation_init();
3574
3575 Management::initialize(THREAD);
3576 if (HAS_PENDING_EXCEPTION) {
3577 // management agent fails to start possibly due to
3578 // configuration problem and is responsible for printing
3579 // stack trace if appropriate. Simply exit VM.
3580 vm_exit(1);
3581 }
3582
3583 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3584 if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
3585 if (MemProfiling) MemProfiler::engage();
3586 StatSampler::engage();
3587 if (CheckJNICalls) JniPeriodicChecker::engage();
3588
3589 BiasedLocking::init();
3590
3591 if (JDK_Version::current().post_vm_init_hook_enabled()) {
3592 call_postVMInitHook(THREAD);
3593 // The Java side of PostVMInitHook.run must deal with all
3594 // exceptions and provide means of diagnosis.
3595 if (HAS_PENDING_EXCEPTION) {
3596 CLEAR_PENDING_EXCEPTION;
3597 }
3598 }
3599
3600 // Start up the WatcherThread if there are any periodic tasks
3601 // NOTE: All PeriodicTasks should be registered by now. If they
3602 // aren't, late joiners might appear to start slowly (we might
3603 // take a while to process their first tick).
3604 if (PeriodicTask::num_tasks() > 0) {
3605 WatcherThread::start();
3606 }
3607
3608 // Give os specific code one last chance to start
3609 os::init_3();
3610
3611 create_vm_timer.end();
3612 #ifdef ASSERT
3613 _vm_complete = true;
3614 #endif
3615 return JNI_OK;
3616 }
3617
3618 // type for the Agent_OnLoad and JVM_OnLoad entry points
3619 extern "C" {
3620 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3621 }
3622 // Find a command line agent library and return its entry point for
3623 // -agentlib: -agentpath: -Xrun
3624 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3625 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3626 OnLoadEntry_t on_load_entry = NULL;
3627 void *library = agent->os_lib(); // check if we have looked it up before
3628
3629 if (library == NULL) {
3630 char buffer[JVM_MAXPATHLEN];
3631 char ebuf[1024];
3632 const char *name = agent->name();
3633 const char *msg = "Could not find agent library ";
3634
3635 if (agent->is_absolute_path()) {
3636 library = os::dll_load(name, ebuf, sizeof ebuf);
3637 if (library == NULL) {
3638 const char *sub_msg = " in absolute path, with error: ";
3639 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3640 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3641 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3642 // If we can't find the agent, exit.
3643 vm_exit_during_initialization(buf, NULL);
3644 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3645 }
3646 } else {
3647 // Try to load the agent from the standard dll directory
3648 os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name);
3649 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3650 #ifdef KERNEL
3651 // Download instrument dll
3652 if (library == NULL && strcmp(name, "instrument") == 0) {
3653 char *props = Arguments::get_kernel_properties();
3654 char *home = Arguments::get_java_home();
3655 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false"
3656 " sun.jkernel.DownloadManager -download client_jvm";
3657 size_t length = strlen(props) + strlen(home) + strlen(fmt) + 1;
3658 char *cmd = NEW_C_HEAP_ARRAY(char, length, mtThread);
3659 jio_snprintf(cmd, length, fmt, home, props);
3660 int status = os::fork_and_exec(cmd);
3661 FreeHeap(props);
3662 if (status == -1) {
3663 warning(cmd);
3664 vm_exit_during_initialization("fork_and_exec failed: %s",
3665 strerror(errno));
3666 }
3667 FREE_C_HEAP_ARRAY(char, cmd, mtThread);
3668 // when this comes back the instrument.dll should be where it belongs.
3669 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3670 }
3671 #endif // KERNEL
3672 if (library == NULL) { // Try the local directory
3673 char ns[1] = {0};
3674 os::dll_build_name(buffer, sizeof(buffer), ns, name);
3675 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3676 if (library == NULL) {
3677 const char *sub_msg = " on the library path, with error: ";
3678 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3679 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3680 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3681 // If we can't find the agent, exit.
3682 vm_exit_during_initialization(buf, NULL);
3683 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3684 }
3685 }
3686 }
3687 agent->set_os_lib(library);
3688 }
3689
3690 // Find the OnLoad function.
3691 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
3692 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, os::dll_lookup(library, on_load_symbols[symbol_index]));
3693 if (on_load_entry != NULL) break;
3694 }
3695 return on_load_entry;
3696 }
3697
3698 // Find the JVM_OnLoad entry point
3699 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3700 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3701 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3702 }
3703
3704 // Find the Agent_OnLoad entry point
3705 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3706 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3707 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3708 }
3709
3710 // For backwards compatibility with -Xrun
3711 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3712 // treated like -agentpath:
3713 // Must be called before agent libraries are created
3714 void Threads::convert_vm_init_libraries_to_agents() {
3715 AgentLibrary* agent;
3716 AgentLibrary* next;
3717
3718 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3719 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3720 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3721
3722 // If there is an JVM_OnLoad function it will get called later,
3723 // otherwise see if there is an Agent_OnLoad
3724 if (on_load_entry == NULL) {
3725 on_load_entry = lookup_agent_on_load(agent);
3726 if (on_load_entry != NULL) {
3727 // switch it to the agent list -- so that Agent_OnLoad will be called,
3728 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3729 Arguments::convert_library_to_agent(agent);
3730 } else {
3731 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3732 }
3733 }
3734 }
3735 }
3736
3737 // Create agents for -agentlib: -agentpath: and converted -Xrun
3738 // Invokes Agent_OnLoad
3739 // Called very early -- before JavaThreads exist
3740 void Threads::create_vm_init_agents() {
3741 extern struct JavaVM_ main_vm;
3742 AgentLibrary* agent;
3743
3744 JvmtiExport::enter_onload_phase();
3745 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3746 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3747
3748 if (on_load_entry != NULL) {
3749 // Invoke the Agent_OnLoad function
3750 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3751 if (err != JNI_OK) {
3752 vm_exit_during_initialization("agent library failed to init", agent->name());
3753 }
3754 } else {
3755 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3756 }
3757 }
3758 JvmtiExport::enter_primordial_phase();
3759 }
3760
3761 extern "C" {
3762 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3763 }
3764
3765 void Threads::shutdown_vm_agents() {
3766 // Send any Agent_OnUnload notifications
3767 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3768 extern struct JavaVM_ main_vm;
3769 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3770
3771 // Find the Agent_OnUnload function.
3772 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
3773 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3774 os::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
3775
3776 // Invoke the Agent_OnUnload function
3777 if (unload_entry != NULL) {
3778 JavaThread* thread = JavaThread::current();
3779 ThreadToNativeFromVM ttn(thread);
3780 HandleMark hm(thread);
3781 (*unload_entry)(&main_vm);
3782 break;
3783 }
3784 }
3785 }
3786 }
3787
3788 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3789 // Invokes JVM_OnLoad
3790 void Threads::create_vm_init_libraries() {
3791 extern struct JavaVM_ main_vm;
3792 AgentLibrary* agent;
3793
3794 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3795 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3796
3797 if (on_load_entry != NULL) {
3798 // Invoke the JVM_OnLoad function
3799 JavaThread* thread = JavaThread::current();
3800 ThreadToNativeFromVM ttn(thread);
3801 HandleMark hm(thread);
3802 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3803 if (err != JNI_OK) {
3804 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3805 }
3806 } else {
3807 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3808 }
3809 }
3810 }
3811
3812 // Last thread running calls java.lang.Shutdown.shutdown()
3813 void JavaThread::invoke_shutdown_hooks() {
3814 HandleMark hm(this);
3815
3816 // We could get here with a pending exception, if so clear it now.
3817 if (this->has_pending_exception()) {
3818 this->clear_pending_exception();
3819 }
3820
3821 EXCEPTION_MARK;
3822 Klass* k =
3823 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3824 THREAD);
3825 if (k != NULL) {
3826 // SystemDictionary::resolve_or_null will return null if there was
3827 // an exception. If we cannot load the Shutdown class, just don't
3828 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3829 // and finalizers (if runFinalizersOnExit is set) won't be run.
3830 // Note that if a shutdown hook was registered or runFinalizersOnExit
3831 // was called, the Shutdown class would have already been loaded
3832 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3833 instanceKlassHandle shutdown_klass (THREAD, k);
3834 JavaValue result(T_VOID);
3835 JavaCalls::call_static(&result,
3836 shutdown_klass,
3837 vmSymbols::shutdown_method_name(),
3838 vmSymbols::void_method_signature(),
3839 THREAD);
3840 }
3841 CLEAR_PENDING_EXCEPTION;
3842 }
3843
3844 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3845 // the program falls off the end of main(). Another VM exit path is through
3846 // vm_exit() when the program calls System.exit() to return a value or when
3847 // there is a serious error in VM. The two shutdown paths are not exactly
3848 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3849 // and VM_Exit op at VM level.
3850 //
3851 // Shutdown sequence:
3852 // + Shutdown native memory tracking if it is on
3853 // + Wait until we are the last non-daemon thread to execute
3854 // <-- every thing is still working at this moment -->
3855 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3856 // shutdown hooks, run finalizers if finalization-on-exit
3857 // + Call before_exit(), prepare for VM exit
3858 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3859 // currently the only user of this mechanism is File.deleteOnExit())
3860 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3861 // post thread end and vm death events to JVMTI,
3862 // stop signal thread
3863 // + Call JavaThread::exit(), it will:
3864 // > release JNI handle blocks, remove stack guard pages
3865 // > remove this thread from Threads list
3866 // <-- no more Java code from this thread after this point -->
3867 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3868 // the compiler threads at safepoint
3869 // <-- do not use anything that could get blocked by Safepoint -->
3870 // + Disable tracing at JNI/JVM barriers
3871 // + Set _vm_exited flag for threads that are still running native code
3872 // + Delete this thread
3873 // + Call exit_globals()
3874 // > deletes tty
3875 // > deletes PerfMemory resources
3876 // + Return to caller
3877
3878 bool Threads::destroy_vm() {
3879 JavaThread* thread = JavaThread::current();
3880
3881 #ifdef ASSERT
3882 _vm_complete = false;
3883 #endif
3884 // Wait until we are the last non-daemon thread to execute
3885 { MutexLocker nu(Threads_lock);
3886 while (Threads::number_of_non_daemon_threads() > 1 )
3887 // This wait should make safepoint checks, wait without a timeout,
3888 // and wait as a suspend-equivalent condition.
3889 //
3890 // Note: If the FlatProfiler is running and this thread is waiting
3891 // for another non-daemon thread to finish, then the FlatProfiler
3892 // is waiting for the external suspend request on this thread to
3893 // complete. wait_for_ext_suspend_completion() will eventually
3894 // timeout, but that takes time. Making this wait a suspend-
3895 // equivalent condition solves that timeout problem.
3896 //
3897 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
3898 Mutex::_as_suspend_equivalent_flag);
3899 }
3900
3901 // Shutdown NMT before exit. Otherwise,
3902 // it will run into trouble when system destroys static variables.
3903 MemTracker::shutdown(MemTracker::NMT_normal);
3904
3905 // Hang forever on exit if we are reporting an error.
3906 if (ShowMessageBoxOnError && is_error_reported()) {
3907 os::infinite_sleep();
3908 }
3909 os::wait_for_keypress_at_exit();
3910
3911 if (JDK_Version::is_jdk12x_version()) {
3912 // We are the last thread running, so check if finalizers should be run.
3913 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
3914 HandleMark rm(thread);
3915 Universe::run_finalizers_on_exit();
3916 } else {
3917 // run Java level shutdown hooks
3918 thread->invoke_shutdown_hooks();
3919 }
3920
3921 before_exit(thread);
3922
3923 thread->exit(true);
3924
3925 // Stop VM thread.
3926 {
3927 // 4945125 The vm thread comes to a safepoint during exit.
3928 // GC vm_operations can get caught at the safepoint, and the
3929 // heap is unparseable if they are caught. Grab the Heap_lock
3930 // to prevent this. The GC vm_operations will not be able to
3931 // queue until after the vm thread is dead.
3932 // After this point, we'll never emerge out of the safepoint before
3933 // the VM exits, so concurrent GC threads do not need to be explicitly
3934 // stopped; they remain inactive until the process exits.
3935 // Note: some concurrent G1 threads may be running during a safepoint,
3936 // but these will not be accessing the heap, just some G1-specific side
3937 // data structures that are not accessed by any other threads but them
3938 // after this point in a terminal safepoint.
3939
3940 MutexLocker ml(Heap_lock);
3941
3942 VMThread::wait_for_vm_thread_exit();
3943 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3944 VMThread::destroy();
3945 }
3946
3947 // clean up ideal graph printers
3948 #if defined(COMPILER2) && !defined(PRODUCT)
3949 IdealGraphPrinter::clean_up();
3950 #endif
3951
3952 // Now, all Java threads are gone except daemon threads. Daemon threads
3953 // running Java code or in VM are stopped by the Safepoint. However,
3954 // daemon threads executing native code are still running. But they
3955 // will be stopped at native=>Java/VM barriers. Note that we can't
3956 // simply kill or suspend them, as it is inherently deadlock-prone.
3957
3958 #ifndef PRODUCT
3959 // disable function tracing at JNI/JVM barriers
3960 TraceJNICalls = false;
3961 TraceJVMCalls = false;
3962 TraceRuntimeCalls = false;
3963 #endif
3964
3965 VM_Exit::set_vm_exited();
3966
3967 notify_vm_shutdown();
3968
3969 delete thread;
3970
3971 // exit_globals() will delete tty
3972 exit_globals();
3973
3974 return true;
3975 }
3976
3977
3978 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3979 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3980 return is_supported_jni_version(version);
3981 }
3982
3983
3984 jboolean Threads::is_supported_jni_version(jint version) {
3985 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3986 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3987 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3988 return JNI_FALSE;
3989 }
3990
3991
3992 void Threads::add(JavaThread* p, bool force_daemon) {
3993 // The threads lock must be owned at this point
3994 assert_locked_or_safepoint(Threads_lock);
3995
3996 // See the comment for this method in thread.hpp for its purpose and
3997 // why it is called here.
3998 p->initialize_queues();
3999 p->set_next(_thread_list);
4000 _thread_list = p;
4001 _number_of_threads++;
4002 oop threadObj = p->threadObj();
4003 bool daemon = true;
4004 // Bootstrapping problem: threadObj can be null for initial
4005 // JavaThread (or for threads attached via JNI)
4006 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
4007 _number_of_non_daemon_threads++;
4008 daemon = false;
4009 }
4010
4011 p->set_safepoint_visible(true);
4012
4013 ThreadService::add_thread(p, daemon);
4014
4015 // Possible GC point.
4016 Events::log(p, "Thread added: " INTPTR_FORMAT, p);
4017 }
4018
4019 void Threads::remove(JavaThread* p) {
4020 // Extra scope needed for Thread_lock, so we can check
4021 // that we do not remove thread without safepoint code notice
4022 { MutexLocker ml(Threads_lock);
4023
4024 assert(includes(p), "p must be present");
4025
4026 JavaThread* current = _thread_list;
4027 JavaThread* prev = NULL;
4028
4029 while (current != p) {
4030 prev = current;
4031 current = current->next();
4032 }
4033
4034 if (prev) {
4035 prev->set_next(current->next());
4036 } else {
4037 _thread_list = p->next();
4038 }
4039 _number_of_threads--;
4040 oop threadObj = p->threadObj();
4041 bool daemon = true;
4042 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
4043 _number_of_non_daemon_threads--;
4044 daemon = false;
4045
4046 // Only one thread left, do a notify on the Threads_lock so a thread waiting
4047 // on destroy_vm will wake up.
4048 if (number_of_non_daemon_threads() == 1)
4049 Threads_lock->notify_all();
4050 }
4051 ThreadService::remove_thread(p, daemon);
4052
4053 // Make sure that safepoint code disregard this thread. This is needed since
4054 // the thread might mess around with locks after this point. This can cause it
4055 // to do callbacks into the safepoint code. However, the safepoint code is not aware
4056 // of this thread since it is removed from the queue.
4057 p->set_terminated_value();
4058
4059 // Now, this thread is not visible to safepoint
4060 p->set_safepoint_visible(false);
4061
4062 } // unlock Threads_lock
4063
4064 // Since Events::log uses a lock, we grab it outside the Threads_lock
4065 Events::log(p, "Thread exited: " INTPTR_FORMAT, p);
4066 }
4067
4068 // Threads_lock must be held when this is called (or must be called during a safepoint)
4069 bool Threads::includes(JavaThread* p) {
4070 assert(Threads_lock->is_locked(), "sanity check");
4071 ALL_JAVA_THREADS(q) {
4072 if (q == p ) {
4073 return true;
4074 }
4075 }
4076 return false;
4077 }
4078
4079 // Operations on the Threads list for GC. These are not explicitly locked,
4080 // but the garbage collector must provide a safe context for them to run.
4081 // In particular, these things should never be called when the Threads_lock
4082 // is held by some other thread. (Note: the Safepoint abstraction also
4083 // uses the Threads_lock to gurantee this property. It also makes sure that
4084 // all threads gets blocked when exiting or starting).
4085
4086 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
4087 ALL_JAVA_THREADS(p) {
4088 p->oops_do(f, cf);
4089 }
4090 VMThread::vm_thread()->oops_do(f, cf);
4091 }
4092
4093 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) {
4094 // Introduce a mechanism allowing parallel threads to claim threads as
4095 // root groups. Overhead should be small enough to use all the time,
4096 // even in sequential code.
4097 SharedHeap* sh = SharedHeap::heap();
4098 // Cannot yet substitute active_workers for n_par_threads
4099 // because of G1CollectedHeap::verify() use of
4100 // SharedHeap::process_strong_roots(). n_par_threads == 0 will
4101 // turn off parallelism in process_strong_roots while active_workers
4102 // is being used for parallelism elsewhere.
4103 bool is_par = sh->n_par_threads() > 0;
4104 assert(!is_par ||
4105 (SharedHeap::heap()->n_par_threads() ==
4106 SharedHeap::heap()->workers()->active_workers()), "Mismatch");
4107 int cp = SharedHeap::heap()->strong_roots_parity();
4108 ALL_JAVA_THREADS(p) {
4109 if (p->claim_oops_do(is_par, cp)) {
4110 p->oops_do(f, cf);
4111 }
4112 }
4113 VMThread* vmt = VMThread::vm_thread();
4114 if (vmt->claim_oops_do(is_par, cp)) {
4115 vmt->oops_do(f, cf);
4116 }
4117 }
4118
4119 #ifndef SERIALGC
4120 // Used by ParallelScavenge
4121 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
4122 ALL_JAVA_THREADS(p) {
4123 q->enqueue(new ThreadRootsTask(p));
4124 }
4125 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
4126 }
4127
4128 // Used by Parallel Old
4129 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
4130 ALL_JAVA_THREADS(p) {
4131 q->enqueue(new ThreadRootsMarkingTask(p));
4132 }
4133 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
4134 }
4135 #endif // SERIALGC
4136
4137 void Threads::nmethods_do(CodeBlobClosure* cf) {
4138 ALL_JAVA_THREADS(p) {
4139 p->nmethods_do(cf);
4140 }
4141 VMThread::vm_thread()->nmethods_do(cf);
4142 }
4143
4144 void Threads::metadata_do(void f(Metadata*)) {
4145 ALL_JAVA_THREADS(p) {
4146 p->metadata_do(f);
4147 }
4148 }
4149
4150 void Threads::gc_epilogue() {
4151 ALL_JAVA_THREADS(p) {
4152 p->gc_epilogue();
4153 }
4154 }
4155
4156 void Threads::gc_prologue() {
4157 ALL_JAVA_THREADS(p) {
4158 p->gc_prologue();
4159 }
4160 }
4161
4162 void Threads::deoptimized_wrt_marked_nmethods() {
4163 ALL_JAVA_THREADS(p) {
4164 p->deoptimized_wrt_marked_nmethods();
4165 }
4166 }
4167
4168
4169 // Get count Java threads that are waiting to enter the specified monitor.
4170 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
4171 address monitor, bool doLock) {
4172 assert(doLock || SafepointSynchronize::is_at_safepoint(),
4173 "must grab Threads_lock or be at safepoint");
4174 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
4175
4176 int i = 0;
4177 {
4178 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4179 ALL_JAVA_THREADS(p) {
4180 if (p->is_Compiler_thread()) continue;
4181
4182 address pending = (address)p->current_pending_monitor();
4183 if (pending == monitor) { // found a match
4184 if (i < count) result->append(p); // save the first count matches
4185 i++;
4186 }
4187 }
4188 }
4189 return result;
4190 }
4191
4192
4193 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
4194 assert(doLock ||
4195 Threads_lock->owned_by_self() ||
4196 SafepointSynchronize::is_at_safepoint(),
4197 "must grab Threads_lock or be at safepoint");
4198
4199 // NULL owner means not locked so we can skip the search
4200 if (owner == NULL) return NULL;
4201
4202 {
4203 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4204 ALL_JAVA_THREADS(p) {
4205 // first, see if owner is the address of a Java thread
4206 if (owner == (address)p) return p;
4207 }
4208 }
4209 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
4210 if (UseHeavyMonitors) return NULL;
4211
4212 //
4213 // If we didn't find a matching Java thread and we didn't force use of
4214 // heavyweight monitors, then the owner is the stack address of the
4215 // Lock Word in the owning Java thread's stack.
4216 //
4217 JavaThread* the_owner = NULL;
4218 {
4219 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4220 ALL_JAVA_THREADS(q) {
4221 if (q->is_lock_owned(owner)) {
4222 the_owner = q;
4223 break;
4224 }
4225 }
4226 }
4227 assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
4228 return the_owner;
4229 }
4230
4231 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
4232 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
4233 char buf[32];
4234 st->print_cr(os::local_time_string(buf, sizeof(buf)));
4235
4236 st->print_cr("Full thread dump %s (%s %s):",
4237 Abstract_VM_Version::vm_name(),
4238 Abstract_VM_Version::vm_release(),
4239 Abstract_VM_Version::vm_info_string()
4240 );
4241 st->cr();
4242
4243 #ifndef SERIALGC
4244 // Dump concurrent locks
4245 ConcurrentLocksDump concurrent_locks;
4246 if (print_concurrent_locks) {
4247 concurrent_locks.dump_at_safepoint();
4248 }
4249 #endif // SERIALGC
4250
4251 ALL_JAVA_THREADS(p) {
4252 ResourceMark rm;
4253 p->print_on(st);
4254 if (print_stacks) {
4255 if (internal_format) {
4256 p->trace_stack();
4257 } else {
4258 p->print_stack_on(st);
4259 }
4260 }
4261 st->cr();
4262 #ifndef SERIALGC
4263 if (print_concurrent_locks) {
4264 concurrent_locks.print_locks_on(p, st);
4265 }
4266 #endif // SERIALGC
4267 }
4268
4269 VMThread::vm_thread()->print_on(st);
4270 st->cr();
4271 Universe::heap()->print_gc_threads_on(st);
4272 WatcherThread* wt = WatcherThread::watcher_thread();
4273 if (wt != NULL) wt->print_on(st);
4274 st->cr();
4275 CompileBroker::print_compiler_threads_on(st);
4276 st->flush();
4277 }
4278
4279 // Threads::print_on_error() is called by fatal error handler. It's possible
4280 // that VM is not at safepoint and/or current thread is inside signal handler.
4281 // Don't print stack trace, as the stack may not be walkable. Don't allocate
4282 // memory (even in resource area), it might deadlock the error handler.
4283 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
4284 bool found_current = false;
4285 st->print_cr("Java Threads: ( => current thread )");
4286 ALL_JAVA_THREADS(thread) {
4287 bool is_current = (current == thread);
4288 found_current = found_current || is_current;
4289
4290 st->print("%s", is_current ? "=>" : " ");
4291
4292 st->print(PTR_FORMAT, thread);
4293 st->print(" ");
4294 thread->print_on_error(st, buf, buflen);
4295 st->cr();
4296 }
4297 st->cr();
4298
4299 st->print_cr("Other Threads:");
4300 if (VMThread::vm_thread()) {
4301 bool is_current = (current == VMThread::vm_thread());
4302 found_current = found_current || is_current;
4303 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
4304
4305 st->print(PTR_FORMAT, VMThread::vm_thread());
4306 st->print(" ");
4307 VMThread::vm_thread()->print_on_error(st, buf, buflen);
4308 st->cr();
4309 }
4310 WatcherThread* wt = WatcherThread::watcher_thread();
4311 if (wt != NULL) {
4312 bool is_current = (current == wt);
4313 found_current = found_current || is_current;
4314 st->print("%s", is_current ? "=>" : " ");
4315
4316 st->print(PTR_FORMAT, wt);
4317 st->print(" ");
4318 wt->print_on_error(st, buf, buflen);
4319 st->cr();
4320 }
4321 if (!found_current) {
4322 st->cr();
4323 st->print("=>" PTR_FORMAT " (exited) ", current);
4324 current->print_on_error(st, buf, buflen);
4325 st->cr();
4326 }
4327 }
4328
4329 // Internal SpinLock and Mutex
4330 // Based on ParkEvent
4331
4332 // Ad-hoc mutual exclusion primitives: SpinLock and Mux
4333 //
4334 // We employ SpinLocks _only for low-contention, fixed-length
4335 // short-duration critical sections where we're concerned
4336 // about native mutex_t or HotSpot Mutex:: latency.
4337 // The mux construct provides a spin-then-block mutual exclusion
4338 // mechanism.
4339 //
4340 // Testing has shown that contention on the ListLock guarding gFreeList
4341 // is common. If we implement ListLock as a simple SpinLock it's common
4342 // for the JVM to devolve to yielding with little progress. This is true
4343 // despite the fact that the critical sections protected by ListLock are
4344 // extremely short.
4345 //
4346 // TODO-FIXME: ListLock should be of type SpinLock.
4347 // We should make this a 1st-class type, integrated into the lock
4348 // hierarchy as leaf-locks. Critically, the SpinLock structure
4349 // should have sufficient padding to avoid false-sharing and excessive
4350 // cache-coherency traffic.
4351
4352
4353 typedef volatile int SpinLockT ;
4354
4355 void Thread::SpinAcquire (volatile int * adr, const char * LockName) {
4356 if (Atomic::cmpxchg (1, adr, 0) == 0) {
4357 return ; // normal fast-path return
4358 }
4359
4360 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
4361 TEVENT (SpinAcquire - ctx) ;
4362 int ctr = 0 ;
4363 int Yields = 0 ;
4364 for (;;) {
4365 while (*adr != 0) {
4366 ++ctr ;
4367 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
4368 if (Yields > 5) {
4369 // Consider using a simple NakedSleep() instead.
4370 // Then SpinAcquire could be called by non-JVM threads
4371 Thread::current()->_ParkEvent->park(1) ;
4372 } else {
4373 os::NakedYield() ;
4374 ++Yields ;
4375 }
4376 } else {
4377 SpinPause() ;
4378 }
4379 }
4380 if (Atomic::cmpxchg (1, adr, 0) == 0) return ;
4381 }
4382 }
4383
4384 void Thread::SpinRelease (volatile int * adr) {
4385 assert (*adr != 0, "invariant") ;
4386 OrderAccess::fence() ; // guarantee at least release consistency.
4387 // Roach-motel semantics.
4388 // It's safe if subsequent LDs and STs float "up" into the critical section,
4389 // but prior LDs and STs within the critical section can't be allowed
4390 // to reorder or float past the ST that releases the lock.
4391 *adr = 0 ;
4392 }
4393
4394 // muxAcquire and muxRelease:
4395 //
4396 // * muxAcquire and muxRelease support a single-word lock-word construct.
4397 // The LSB of the word is set IFF the lock is held.
4398 // The remainder of the word points to the head of a singly-linked list
4399 // of threads blocked on the lock.
4400 //
4401 // * The current implementation of muxAcquire-muxRelease uses its own
4402 // dedicated Thread._MuxEvent instance. If we're interested in
4403 // minimizing the peak number of extant ParkEvent instances then
4404 // we could eliminate _MuxEvent and "borrow" _ParkEvent as long
4405 // as certain invariants were satisfied. Specifically, care would need
4406 // to be taken with regards to consuming unpark() "permits".
4407 // A safe rule of thumb is that a thread would never call muxAcquire()
4408 // if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently
4409 // park(). Otherwise the _ParkEvent park() operation in muxAcquire() could
4410 // consume an unpark() permit intended for monitorenter, for instance.
4411 // One way around this would be to widen the restricted-range semaphore
4412 // implemented in park(). Another alternative would be to provide
4413 // multiple instances of the PlatformEvent() for each thread. One
4414 // instance would be dedicated to muxAcquire-muxRelease, for instance.
4415 //
4416 // * Usage:
4417 // -- Only as leaf locks
4418 // -- for short-term locking only as muxAcquire does not perform
4419 // thread state transitions.
4420 //
4421 // Alternatives:
4422 // * We could implement muxAcquire and muxRelease with MCS or CLH locks
4423 // but with parking or spin-then-park instead of pure spinning.
4424 // * Use Taura-Oyama-Yonenzawa locks.
4425 // * It's possible to construct a 1-0 lock if we encode the lockword as
4426 // (List,LockByte). Acquire will CAS the full lockword while Release
4427 // will STB 0 into the LockByte. The 1-0 scheme admits stranding, so
4428 // acquiring threads use timers (ParkTimed) to detect and recover from
4429 // the stranding window. Thread/Node structures must be aligned on 256-byte
4430 // boundaries by using placement-new.
4431 // * Augment MCS with advisory back-link fields maintained with CAS().
4432 // Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner.
4433 // The validity of the backlinks must be ratified before we trust the value.
4434 // If the backlinks are invalid the exiting thread must back-track through the
4435 // the forward links, which are always trustworthy.
4436 // * Add a successor indication. The LockWord is currently encoded as
4437 // (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable
4438 // to provide the usual futile-wakeup optimization.
4439 // See RTStt for details.
4440 // * Consider schedctl.sc_nopreempt to cover the critical section.
4441 //
4442
4443
4444 typedef volatile intptr_t MutexT ; // Mux Lock-word
4445 enum MuxBits { LOCKBIT = 1 } ;
4446
4447 void Thread::muxAcquire (volatile intptr_t * Lock, const char * LockName) {
4448 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4449 if (w == 0) return ;
4450 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4451 return ;
4452 }
4453
4454 TEVENT (muxAcquire - Contention) ;
4455 ParkEvent * const Self = Thread::current()->_MuxEvent ;
4456 assert ((intptr_t(Self) & LOCKBIT) == 0, "invariant") ;
4457 for (;;) {
4458 int its = (os::is_MP() ? 100 : 0) + 1 ;
4459
4460 // Optional spin phase: spin-then-park strategy
4461 while (--its >= 0) {
4462 w = *Lock ;
4463 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4464 return ;
4465 }
4466 }
4467
4468 Self->reset() ;
4469 Self->OnList = intptr_t(Lock) ;
4470 // The following fence() isn't _strictly necessary as the subsequent
4471 // CAS() both serializes execution and ratifies the fetched *Lock value.
4472 OrderAccess::fence();
4473 for (;;) {
4474 w = *Lock ;
4475 if ((w & LOCKBIT) == 0) {
4476 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4477 Self->OnList = 0 ; // hygiene - allows stronger asserts
4478 return ;
4479 }
4480 continue ; // Interference -- *Lock changed -- Just retry
4481 }
4482 assert (w & LOCKBIT, "invariant") ;
4483 Self->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4484 if (Atomic::cmpxchg_ptr (intptr_t(Self)|LOCKBIT, Lock, w) == w) break ;
4485 }
4486
4487 while (Self->OnList != 0) {
4488 Self->park() ;
4489 }
4490 }
4491 }
4492
4493 void Thread::muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) {
4494 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4495 if (w == 0) return ;
4496 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4497 return ;
4498 }
4499
4500 TEVENT (muxAcquire - Contention) ;
4501 ParkEvent * ReleaseAfter = NULL ;
4502 if (ev == NULL) {
4503 ev = ReleaseAfter = ParkEvent::Allocate (NULL) ;
4504 }
4505 assert ((intptr_t(ev) & LOCKBIT) == 0, "invariant") ;
4506 for (;;) {
4507 guarantee (ev->OnList == 0, "invariant") ;
4508 int its = (os::is_MP() ? 100 : 0) + 1 ;
4509
4510 // Optional spin phase: spin-then-park strategy
4511 while (--its >= 0) {
4512 w = *Lock ;
4513 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4514 if (ReleaseAfter != NULL) {
4515 ParkEvent::Release (ReleaseAfter) ;
4516 }
4517 return ;
4518 }
4519 }
4520
4521 ev->reset() ;
4522 ev->OnList = intptr_t(Lock) ;
4523 // The following fence() isn't _strictly necessary as the subsequent
4524 // CAS() both serializes execution and ratifies the fetched *Lock value.
4525 OrderAccess::fence();
4526 for (;;) {
4527 w = *Lock ;
4528 if ((w & LOCKBIT) == 0) {
4529 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4530 ev->OnList = 0 ;
4531 // We call ::Release while holding the outer lock, thus
4532 // artificially lengthening the critical section.
4533 // Consider deferring the ::Release() until the subsequent unlock(),
4534 // after we've dropped the outer lock.
4535 if (ReleaseAfter != NULL) {
4536 ParkEvent::Release (ReleaseAfter) ;
4537 }
4538 return ;
4539 }
4540 continue ; // Interference -- *Lock changed -- Just retry
4541 }
4542 assert (w & LOCKBIT, "invariant") ;
4543 ev->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4544 if (Atomic::cmpxchg_ptr (intptr_t(ev)|LOCKBIT, Lock, w) == w) break ;
4545 }
4546
4547 while (ev->OnList != 0) {
4548 ev->park() ;
4549 }
4550 }
4551 }
4552
4553 // Release() must extract a successor from the list and then wake that thread.
4554 // It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme
4555 // similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based
4556 // Release() would :
4557 // (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list.
4558 // (B) Extract a successor from the private list "in-hand"
4559 // (C) attempt to CAS() the residual back into *Lock over null.
4560 // If there were any newly arrived threads and the CAS() would fail.
4561 // In that case Release() would detach the RATs, re-merge the list in-hand
4562 // with the RATs and repeat as needed. Alternately, Release() might
4563 // detach and extract a successor, but then pass the residual list to the wakee.
4564 // The wakee would be responsible for reattaching and remerging before it
4565 // competed for the lock.
4566 //
4567 // Both "pop" and DMR are immune from ABA corruption -- there can be
4568 // multiple concurrent pushers, but only one popper or detacher.
4569 // This implementation pops from the head of the list. This is unfair,
4570 // but tends to provide excellent throughput as hot threads remain hot.
4571 // (We wake recently run threads first).
4572
4573 void Thread::muxRelease (volatile intptr_t * Lock) {
4574 for (;;) {
4575 const intptr_t w = Atomic::cmpxchg_ptr (0, Lock, LOCKBIT) ;
4576 assert (w & LOCKBIT, "invariant") ;
4577 if (w == LOCKBIT) return ;
4578 ParkEvent * List = (ParkEvent *) (w & ~LOCKBIT) ;
4579 assert (List != NULL, "invariant") ;
4580 assert (List->OnList == intptr_t(Lock), "invariant") ;
4581 ParkEvent * nxt = List->ListNext ;
4582
4583 // The following CAS() releases the lock and pops the head element.
4584 if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) {
4585 continue ;
4586 }
4587 List->OnList = 0 ;
4588 OrderAccess::fence() ;
4589 List->unpark () ;
4590 return ;
4591 }
4592 }
4593
4594
4595 void Threads::verify() {
4596 ALL_JAVA_THREADS(p) {
4597 p->verify();
4598 }
4599 VMThread* thread = VMThread::vm_thread();
4600 if (thread != NULL) thread->verify();
4601 }