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 int os_prio;
840 if (os::get_native_priority(this, &os_prio) == OS_OK) {
841 st->print("os_prio=%d ", os_prio);
842 }
843 st->print("tid=" INTPTR_FORMAT " ", this);
844 osthread()->print_on(st);
845 }
846 debug_only(if (WizardMode) print_owned_locks_on(st);)
847 }
848
849 // Thread::print_on_error() is called by fatal error handler. Don't use
850 // any lock or allocate memory.
851 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
852 if (is_VM_thread()) st->print("VMThread");
853 else if (is_Compiler_thread()) st->print("CompilerThread");
854 else if (is_Java_thread()) st->print("JavaThread");
855 else if (is_GC_task_thread()) st->print("GCTaskThread");
856 else if (is_Watcher_thread()) st->print("WatcherThread");
857 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
858 else st->print("Thread");
859
860 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
861 _stack_base - _stack_size, _stack_base);
862
863 if (osthread()) {
864 st->print(" [id=%d]", osthread()->thread_id());
865 }
866 }
867
868 #ifdef ASSERT
869 void Thread::print_owned_locks_on(outputStream* st) const {
870 Monitor *cur = _owned_locks;
871 if (cur == NULL) {
872 st->print(" (no locks) ");
873 } else {
874 st->print_cr(" Locks owned:");
875 while(cur) {
876 cur->print_on(st);
877 cur = cur->next();
878 }
879 }
880 }
881
882 static int ref_use_count = 0;
883
884 bool Thread::owns_locks_but_compiled_lock() const {
885 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
886 if (cur != Compile_lock) return true;
887 }
888 return false;
889 }
890
891
892 #endif
893
894 #ifndef PRODUCT
895
896 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
897 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
898 // no threads which allow_vm_block's are held
899 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
900 // Check if current thread is allowed to block at a safepoint
901 if (!(_allow_safepoint_count == 0))
902 fatal("Possible safepoint reached by thread that does not allow it");
903 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
904 fatal("LEAF method calling lock?");
905 }
906
907 #ifdef ASSERT
908 if (potential_vm_operation && is_Java_thread()
909 && !Universe::is_bootstrapping()) {
910 // Make sure we do not hold any locks that the VM thread also uses.
911 // This could potentially lead to deadlocks
912 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
913 // Threads_lock is special, since the safepoint synchronization will not start before this is
914 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
915 // since it is used to transfer control between JavaThreads and the VMThread
916 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
917 if ( (cur->allow_vm_block() &&
918 cur != Threads_lock &&
919 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
920 cur != VMOperationRequest_lock &&
921 cur != VMOperationQueue_lock) ||
922 cur->rank() == Mutex::special) {
923 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
924 }
925 }
926 }
927
928 if (GCALotAtAllSafepoints) {
929 // We could enter a safepoint here and thus have a gc
930 InterfaceSupport::check_gc_alot();
931 }
932 #endif
933 }
934 #endif
935
936 bool Thread::is_in_stack(address adr) const {
937 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
938 address end = os::current_stack_pointer();
939 // Allow non Java threads to call this without stack_base
940 if (_stack_base == NULL) return true;
941 if (stack_base() >= adr && adr >= end) return true;
942
943 return false;
944 }
945
946
947 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
948 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
949 // used for compilation in the future. If that change is made, the need for these methods
950 // should be revisited, and they should be removed if possible.
951
952 bool Thread::is_lock_owned(address adr) const {
953 return on_local_stack(adr);
954 }
955
956 bool Thread::set_as_starting_thread() {
957 // NOTE: this must be called inside the main thread.
958 return os::create_main_thread((JavaThread*)this);
959 }
960
961 static void initialize_class(Symbol* class_name, TRAPS) {
962 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
963 InstanceKlass::cast(klass)->initialize(CHECK);
964 }
965
966
967 // Creates the initial ThreadGroup
968 static Handle create_initial_thread_group(TRAPS) {
969 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
970 instanceKlassHandle klass (THREAD, k);
971
972 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
973 {
974 JavaValue result(T_VOID);
975 JavaCalls::call_special(&result,
976 system_instance,
977 klass,
978 vmSymbols::object_initializer_name(),
979 vmSymbols::void_method_signature(),
980 CHECK_NH);
981 }
982 Universe::set_system_thread_group(system_instance());
983
984 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
985 {
986 JavaValue result(T_VOID);
987 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
988 JavaCalls::call_special(&result,
989 main_instance,
990 klass,
991 vmSymbols::object_initializer_name(),
992 vmSymbols::threadgroup_string_void_signature(),
993 system_instance,
994 string,
995 CHECK_NH);
996 }
997 return main_instance;
998 }
999
1000 // Creates the initial Thread
1001 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
1002 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
1003 instanceKlassHandle klass (THREAD, k);
1004 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
1005
1006 java_lang_Thread::set_thread(thread_oop(), thread);
1007 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1008 thread->set_threadObj(thread_oop());
1009
1010 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
1011
1012 JavaValue result(T_VOID);
1013 JavaCalls::call_special(&result, thread_oop,
1014 klass,
1015 vmSymbols::object_initializer_name(),
1016 vmSymbols::threadgroup_string_void_signature(),
1017 thread_group,
1018 string,
1019 CHECK_NULL);
1020 return thread_oop();
1021 }
1022
1023 static void call_initializeSystemClass(TRAPS) {
1024 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1025 instanceKlassHandle klass (THREAD, k);
1026
1027 JavaValue result(T_VOID);
1028 JavaCalls::call_static(&result, klass, vmSymbols::initializeSystemClass_name(),
1029 vmSymbols::void_method_signature(), CHECK);
1030 }
1031
1032 char java_runtime_name[128] = "";
1033
1034 // extract the JRE name from sun.misc.Version.java_runtime_name
1035 static const char* get_java_runtime_name(TRAPS) {
1036 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1037 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1038 fieldDescriptor fd;
1039 bool found = k != NULL &&
1040 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(),
1041 vmSymbols::string_signature(), &fd);
1042 if (found) {
1043 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1044 if (name_oop == NULL)
1045 return NULL;
1046 const char* name = java_lang_String::as_utf8_string(name_oop,
1047 java_runtime_name,
1048 sizeof(java_runtime_name));
1049 return name;
1050 } else {
1051 return NULL;
1052 }
1053 }
1054
1055 // General purpose hook into Java code, run once when the VM is initialized.
1056 // The Java library method itself may be changed independently from the VM.
1057 static void call_postVMInitHook(TRAPS) {
1058 Klass* k = SystemDictionary::PostVMInitHook_klass();
1059 instanceKlassHandle klass (THREAD, k);
1060 if (klass.not_null()) {
1061 JavaValue result(T_VOID);
1062 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
1063 vmSymbols::void_method_signature(),
1064 CHECK);
1065 }
1066 }
1067
1068 static void reset_vm_info_property(TRAPS) {
1069 // the vm info string
1070 ResourceMark rm(THREAD);
1071 const char *vm_info = VM_Version::vm_info_string();
1072
1073 // java.lang.System class
1074 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1075 instanceKlassHandle klass (THREAD, k);
1076
1077 // setProperty arguments
1078 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
1079 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
1080
1081 // return value
1082 JavaValue r(T_OBJECT);
1083
1084 // public static String setProperty(String key, String value);
1085 JavaCalls::call_static(&r,
1086 klass,
1087 vmSymbols::setProperty_name(),
1088 vmSymbols::string_string_string_signature(),
1089 key_str,
1090 value_str,
1091 CHECK);
1092 }
1093
1094
1095 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
1096 assert(thread_group.not_null(), "thread group should be specified");
1097 assert(threadObj() == NULL, "should only create Java thread object once");
1098
1099 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
1100 instanceKlassHandle klass (THREAD, k);
1101 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
1102
1103 java_lang_Thread::set_thread(thread_oop(), this);
1104 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1105 set_threadObj(thread_oop());
1106
1107 JavaValue result(T_VOID);
1108 if (thread_name != NULL) {
1109 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
1110 // Thread gets assigned specified name and null target
1111 JavaCalls::call_special(&result,
1112 thread_oop,
1113 klass,
1114 vmSymbols::object_initializer_name(),
1115 vmSymbols::threadgroup_string_void_signature(),
1116 thread_group, // Argument 1
1117 name, // Argument 2
1118 THREAD);
1119 } else {
1120 // Thread gets assigned name "Thread-nnn" and null target
1121 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
1122 JavaCalls::call_special(&result,
1123 thread_oop,
1124 klass,
1125 vmSymbols::object_initializer_name(),
1126 vmSymbols::threadgroup_runnable_void_signature(),
1127 thread_group, // Argument 1
1128 Handle(), // Argument 2
1129 THREAD);
1130 }
1131
1132
1133 if (daemon) {
1134 java_lang_Thread::set_daemon(thread_oop());
1135 }
1136
1137 if (HAS_PENDING_EXCEPTION) {
1138 return;
1139 }
1140
1141 KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
1142 Handle threadObj(this, this->threadObj());
1143
1144 JavaCalls::call_special(&result,
1145 thread_group,
1146 group,
1147 vmSymbols::add_method_name(),
1148 vmSymbols::thread_void_signature(),
1149 threadObj, // Arg 1
1150 THREAD);
1151
1152
1153 }
1154
1155 // NamedThread -- non-JavaThread subclasses with multiple
1156 // uniquely named instances should derive from this.
1157 NamedThread::NamedThread() : Thread() {
1158 _name = NULL;
1159 _processed_thread = NULL;
1160 }
1161
1162 NamedThread::~NamedThread() {
1163 if (_name != NULL) {
1164 FREE_C_HEAP_ARRAY(char, _name, mtThread);
1165 _name = NULL;
1166 }
1167 }
1168
1169 void NamedThread::set_name(const char* format, ...) {
1170 guarantee(_name == NULL, "Only get to set name once.");
1171 _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);
1172 guarantee(_name != NULL, "alloc failure");
1173 va_list ap;
1174 va_start(ap, format);
1175 jio_vsnprintf(_name, max_name_len, format, ap);
1176 va_end(ap);
1177 }
1178
1179 // ======= WatcherThread ========
1180
1181 // The watcher thread exists to simulate timer interrupts. It should
1182 // be replaced by an abstraction over whatever native support for
1183 // timer interrupts exists on the platform.
1184
1185 WatcherThread* WatcherThread::_watcher_thread = NULL;
1186 volatile bool WatcherThread::_should_terminate = false;
1187
1188 WatcherThread::WatcherThread() : Thread() {
1189 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1190 if (os::create_thread(this, os::watcher_thread)) {
1191 _watcher_thread = this;
1192
1193 // Set the watcher thread to the highest OS priority which should not be
1194 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1195 // is created. The only normal thread using this priority is the reference
1196 // handler thread, which runs for very short intervals only.
1197 // If the VMThread's priority is not lower than the WatcherThread profiling
1198 // will be inaccurate.
1199 os::set_priority(this, MaxPriority);
1200 if (!DisableStartThread) {
1201 os::start_thread(this);
1202 }
1203 }
1204 }
1205
1206 void WatcherThread::run() {
1207 assert(this == watcher_thread(), "just checking");
1208
1209 this->record_stack_base_and_size();
1210 this->initialize_thread_local_storage();
1211 this->set_active_handles(JNIHandleBlock::allocate_block());
1212 while(!_should_terminate) {
1213 assert(watcher_thread() == Thread::current(), "thread consistency check");
1214 assert(watcher_thread() == this, "thread consistency check");
1215
1216 // Calculate how long it'll be until the next PeriodicTask work
1217 // should be done, and sleep that amount of time.
1218 size_t time_to_wait = PeriodicTask::time_to_wait();
1219
1220 // we expect this to timeout - we only ever get unparked when
1221 // we should terminate
1222 {
1223 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1224
1225 jlong prev_time = os::javaTimeNanos();
1226 for (;;) {
1227 int res= _SleepEvent->park(time_to_wait);
1228 if (res == OS_TIMEOUT || _should_terminate)
1229 break;
1230 // spurious wakeup of some kind
1231 jlong now = os::javaTimeNanos();
1232 time_to_wait -= (now - prev_time) / 1000000;
1233 if (time_to_wait <= 0)
1234 break;
1235 prev_time = now;
1236 }
1237 }
1238
1239 if (is_error_reported()) {
1240 // A fatal error has happened, the error handler(VMError::report_and_die)
1241 // should abort JVM after creating an error log file. However in some
1242 // rare cases, the error handler itself might deadlock. Here we try to
1243 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1244 //
1245 // This code is in WatcherThread because WatcherThread wakes up
1246 // periodically so the fatal error handler doesn't need to do anything;
1247 // also because the WatcherThread is less likely to crash than other
1248 // threads.
1249
1250 for (;;) {
1251 if (!ShowMessageBoxOnError
1252 && (OnError == NULL || OnError[0] == '\0')
1253 && Arguments::abort_hook() == NULL) {
1254 os::sleep(this, 2 * 60 * 1000, false);
1255 fdStream err(defaultStream::output_fd());
1256 err.print_raw_cr("# [ timer expired, abort... ]");
1257 // skip atexit/vm_exit/vm_abort hooks
1258 os::die();
1259 }
1260
1261 // Wake up 5 seconds later, the fatal handler may reset OnError or
1262 // ShowMessageBoxOnError when it is ready to abort.
1263 os::sleep(this, 5 * 1000, false);
1264 }
1265 }
1266
1267 PeriodicTask::real_time_tick(time_to_wait);
1268
1269 // If we have no more tasks left due to dynamic disenrollment,
1270 // shut down the thread since we don't currently support dynamic enrollment
1271 if (PeriodicTask::num_tasks() == 0) {
1272 _should_terminate = true;
1273 }
1274 }
1275
1276 // Signal that it is terminated
1277 {
1278 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1279 _watcher_thread = NULL;
1280 Terminator_lock->notify();
1281 }
1282
1283 // Thread destructor usually does this..
1284 ThreadLocalStorage::set_thread(NULL);
1285 }
1286
1287 void WatcherThread::start() {
1288 if (watcher_thread() == NULL) {
1289 _should_terminate = false;
1290 // Create the single instance of WatcherThread
1291 new WatcherThread();
1292 }
1293 }
1294
1295 void WatcherThread::stop() {
1296 // it is ok to take late safepoints here, if needed
1297 MutexLocker mu(Terminator_lock);
1298 _should_terminate = true;
1299 OrderAccess::fence(); // ensure WatcherThread sees update in main loop
1300
1301 Thread* watcher = watcher_thread();
1302 if (watcher != NULL)
1303 watcher->_SleepEvent->unpark();
1304
1305 while(watcher_thread() != NULL) {
1306 // This wait should make safepoint checks, wait without a timeout,
1307 // and wait as a suspend-equivalent condition.
1308 //
1309 // Note: If the FlatProfiler is running, then this thread is waiting
1310 // for the WatcherThread to terminate and the WatcherThread, via the
1311 // FlatProfiler task, is waiting for the external suspend request on
1312 // this thread to complete. wait_for_ext_suspend_completion() will
1313 // eventually timeout, but that takes time. Making this wait a
1314 // suspend-equivalent condition solves that timeout problem.
1315 //
1316 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1317 Mutex::_as_suspend_equivalent_flag);
1318 }
1319 }
1320
1321 void WatcherThread::print_on(outputStream* st) const {
1322 st->print("\"%s\" ", name());
1323 Thread::print_on(st);
1324 st->cr();
1325 }
1326
1327 // ======= JavaThread ========
1328
1329 // A JavaThread is a normal Java thread
1330
1331 void JavaThread::initialize() {
1332 // Initialize fields
1333
1334 // Set the claimed par_id to -1 (ie not claiming any par_ids)
1335 set_claimed_par_id(-1);
1336
1337 set_saved_exception_pc(NULL);
1338 set_threadObj(NULL);
1339 _anchor.clear();
1340 set_entry_point(NULL);
1341 set_jni_functions(jni_functions());
1342 set_callee_target(NULL);
1343 set_vm_result(NULL);
1344 set_vm_result_2(NULL);
1345 set_vframe_array_head(NULL);
1346 set_vframe_array_last(NULL);
1347 set_deferred_locals(NULL);
1348 set_deopt_mark(NULL);
1349 set_deopt_nmethod(NULL);
1350 clear_must_deopt_id();
1351 set_monitor_chunks(NULL);
1352 set_next(NULL);
1353 set_thread_state(_thread_new);
1354 set_recorder(NULL);
1355 _terminated = _not_terminated;
1356 _privileged_stack_top = NULL;
1357 _array_for_gc = NULL;
1358 _suspend_equivalent = false;
1359 _in_deopt_handler = 0;
1360 _doing_unsafe_access = false;
1361 _stack_guard_state = stack_guard_unused;
1362 _exception_oop = NULL;
1363 _exception_pc = 0;
1364 _exception_handler_pc = 0;
1365 _is_method_handle_return = 0;
1366 _jvmti_thread_state= NULL;
1367 _should_post_on_exceptions_flag = JNI_FALSE;
1368 _jvmti_get_loaded_classes_closure = NULL;
1369 _interp_only_mode = 0;
1370 _special_runtime_exit_condition = _no_async_condition;
1371 _pending_async_exception = NULL;
1372 _is_compiling = false;
1373 _thread_stat = NULL;
1374 _thread_stat = new ThreadStatistics();
1375 _blocked_on_compilation = false;
1376 _jni_active_critical = 0;
1377 _do_not_unlock_if_synchronized = false;
1378 _cached_monitor_info = NULL;
1379 _parker = Parker::Allocate(this) ;
1380
1381 #ifndef PRODUCT
1382 _jmp_ring_index = 0;
1383 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1384 record_jump(NULL, NULL, NULL, 0);
1385 }
1386 #endif /* PRODUCT */
1387
1388 set_thread_profiler(NULL);
1389 if (FlatProfiler::is_active()) {
1390 // This is where we would decide to either give each thread it's own profiler
1391 // or use one global one from FlatProfiler,
1392 // or up to some count of the number of profiled threads, etc.
1393 ThreadProfiler* pp = new ThreadProfiler();
1394 pp->engage();
1395 set_thread_profiler(pp);
1396 }
1397
1398 // Setup safepoint state info for this thread
1399 ThreadSafepointState::create(this);
1400
1401 debug_only(_java_call_counter = 0);
1402
1403 // JVMTI PopFrame support
1404 _popframe_condition = popframe_inactive;
1405 _popframe_preserved_args = NULL;
1406 _popframe_preserved_args_size = 0;
1407
1408 pd_initialize();
1409 }
1410
1411 #ifndef SERIALGC
1412 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1413 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1414 #endif // !SERIALGC
1415
1416 JavaThread::JavaThread(bool is_attaching_via_jni) :
1417 Thread()
1418 #ifndef SERIALGC
1419 , _satb_mark_queue(&_satb_mark_queue_set),
1420 _dirty_card_queue(&_dirty_card_queue_set)
1421 #endif // !SERIALGC
1422 {
1423 initialize();
1424 if (is_attaching_via_jni) {
1425 _jni_attach_state = _attaching_via_jni;
1426 } else {
1427 _jni_attach_state = _not_attaching_via_jni;
1428 }
1429 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor");
1430 _safepoint_visible = false;
1431 }
1432
1433 bool JavaThread::reguard_stack(address cur_sp) {
1434 if (_stack_guard_state != stack_guard_yellow_disabled) {
1435 return true; // Stack already guarded or guard pages not needed.
1436 }
1437
1438 if (register_stack_overflow()) {
1439 // For those architectures which have separate register and
1440 // memory stacks, we must check the register stack to see if
1441 // it has overflowed.
1442 return false;
1443 }
1444
1445 // Java code never executes within the yellow zone: the latter is only
1446 // there to provoke an exception during stack banging. If java code
1447 // is executing there, either StackShadowPages should be larger, or
1448 // some exception code in c1, c2 or the interpreter isn't unwinding
1449 // when it should.
1450 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1451
1452 enable_stack_yellow_zone();
1453 return true;
1454 }
1455
1456 bool JavaThread::reguard_stack(void) {
1457 return reguard_stack(os::current_stack_pointer());
1458 }
1459
1460
1461 void JavaThread::block_if_vm_exited() {
1462 if (_terminated == _vm_exited) {
1463 // _vm_exited is set at safepoint, and Threads_lock is never released
1464 // we will block here forever
1465 Threads_lock->lock_without_safepoint_check();
1466 ShouldNotReachHere();
1467 }
1468 }
1469
1470
1471 // Remove this ifdef when C1 is ported to the compiler interface.
1472 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1473
1474 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1475 Thread()
1476 #ifndef SERIALGC
1477 , _satb_mark_queue(&_satb_mark_queue_set),
1478 _dirty_card_queue(&_dirty_card_queue_set)
1479 #endif // !SERIALGC
1480 {
1481 if (TraceThreadEvents) {
1482 tty->print_cr("creating thread %p", this);
1483 }
1484 initialize();
1485 _jni_attach_state = _not_attaching_via_jni;
1486 set_entry_point(entry_point);
1487 // Create the native thread itself.
1488 // %note runtime_23
1489 os::ThreadType thr_type = os::java_thread;
1490 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1491 os::java_thread;
1492 os::create_thread(this, thr_type, stack_sz);
1493 _safepoint_visible = false;
1494 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1495 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1496 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1497 // the exception consists of creating the exception object & initializing it, initialization
1498 // will leave the VM via a JavaCall and then all locks must be unlocked).
1499 //
1500 // The thread is still suspended when we reach here. Thread must be explicit started
1501 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1502 // by calling Threads:add. The reason why this is not done here, is because the thread
1503 // object must be fully initialized (take a look at JVM_Start)
1504 }
1505
1506 JavaThread::~JavaThread() {
1507 if (TraceThreadEvents) {
1508 tty->print_cr("terminate thread %p", this);
1509 }
1510
1511 // Info NMT that this JavaThread is exiting, its memory
1512 // recorder should be collected
1513 assert(!is_safepoint_visible(), "wrong state");
1514 MemTracker::thread_exiting(this);
1515
1516 // JSR166 -- return the parker to the free list
1517 Parker::Release(_parker);
1518 _parker = NULL ;
1519
1520 // Free any remaining previous UnrollBlock
1521 vframeArray* old_array = vframe_array_last();
1522
1523 if (old_array != NULL) {
1524 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1525 old_array->set_unroll_block(NULL);
1526 delete old_info;
1527 delete old_array;
1528 }
1529
1530 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1531 if (deferred != NULL) {
1532 // This can only happen if thread is destroyed before deoptimization occurs.
1533 assert(deferred->length() != 0, "empty array!");
1534 do {
1535 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1536 deferred->remove_at(0);
1537 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1538 delete dlv;
1539 } while (deferred->length() != 0);
1540 delete deferred;
1541 }
1542
1543 // All Java related clean up happens in exit
1544 ThreadSafepointState::destroy(this);
1545 if (_thread_profiler != NULL) delete _thread_profiler;
1546 if (_thread_stat != NULL) delete _thread_stat;
1547 }
1548
1549
1550 // The first routine called by a new Java thread
1551 void JavaThread::run() {
1552 // initialize thread-local alloc buffer related fields
1553 this->initialize_tlab();
1554
1555 // used to test validitity of stack trace backs
1556 this->record_base_of_stack_pointer();
1557
1558 // Record real stack base and size.
1559 this->record_stack_base_and_size();
1560
1561 // Initialize thread local storage; set before calling MutexLocker
1562 this->initialize_thread_local_storage();
1563
1564 this->create_stack_guard_pages();
1565
1566 this->cache_global_variables();
1567
1568 // Thread is now sufficient initialized to be handled by the safepoint code as being
1569 // in the VM. Change thread state from _thread_new to _thread_in_vm
1570 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1571
1572 assert(JavaThread::current() == this, "sanity check");
1573 assert(!Thread::current()->owns_locks(), "sanity check");
1574
1575 DTRACE_THREAD_PROBE(start, this);
1576
1577 // This operation might block. We call that after all safepoint checks for a new thread has
1578 // been completed.
1579 this->set_active_handles(JNIHandleBlock::allocate_block());
1580
1581 if (JvmtiExport::should_post_thread_life()) {
1582 JvmtiExport::post_thread_start(this);
1583 }
1584
1585 EVENT_BEGIN(TraceEventThreadStart, event);
1586 EVENT_COMMIT(event,
1587 EVENT_SET(event, javalangthread, java_lang_Thread::thread_id(this->threadObj())));
1588
1589 // We call another function to do the rest so we are sure that the stack addresses used
1590 // from there will be lower than the stack base just computed
1591 thread_main_inner();
1592
1593 // Note, thread is no longer valid at this point!
1594 }
1595
1596
1597 void JavaThread::thread_main_inner() {
1598 assert(JavaThread::current() == this, "sanity check");
1599 assert(this->threadObj() != NULL, "just checking");
1600
1601 // Execute thread entry point unless this thread has a pending exception
1602 // or has been stopped before starting.
1603 // Note: Due to JVM_StopThread we can have pending exceptions already!
1604 if (!this->has_pending_exception() &&
1605 !java_lang_Thread::is_stillborn(this->threadObj())) {
1606 {
1607 ResourceMark rm(this);
1608 this->set_native_thread_name(this->get_thread_name());
1609 }
1610 HandleMark hm(this);
1611 this->entry_point()(this, this);
1612 }
1613
1614 DTRACE_THREAD_PROBE(stop, this);
1615
1616 this->exit(false);
1617 delete this;
1618 }
1619
1620
1621 static void ensure_join(JavaThread* thread) {
1622 // We do not need to grap the Threads_lock, since we are operating on ourself.
1623 Handle threadObj(thread, thread->threadObj());
1624 assert(threadObj.not_null(), "java thread object must exist");
1625 ObjectLocker lock(threadObj, thread);
1626 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1627 thread->clear_pending_exception();
1628 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1629 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1630 // Clear the native thread instance - this makes isAlive return false and allows the join()
1631 // to complete once we've done the notify_all below
1632 java_lang_Thread::set_thread(threadObj(), NULL);
1633 lock.notify_all(thread);
1634 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1635 thread->clear_pending_exception();
1636 }
1637
1638
1639 // For any new cleanup additions, please check to see if they need to be applied to
1640 // cleanup_failed_attach_current_thread as well.
1641 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1642 assert(this == JavaThread::current(), "thread consistency check");
1643 if (!InitializeJavaLangSystem) return;
1644
1645 HandleMark hm(this);
1646 Handle uncaught_exception(this, this->pending_exception());
1647 this->clear_pending_exception();
1648 Handle threadObj(this, this->threadObj());
1649 assert(threadObj.not_null(), "Java thread object should be created");
1650
1651 if (get_thread_profiler() != NULL) {
1652 get_thread_profiler()->disengage();
1653 ResourceMark rm;
1654 get_thread_profiler()->print(get_thread_name());
1655 }
1656
1657
1658 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1659 {
1660 EXCEPTION_MARK;
1661
1662 CLEAR_PENDING_EXCEPTION;
1663 }
1664 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1665 // has to be fixed by a runtime query method
1666 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1667 // JSR-166: change call from from ThreadGroup.uncaughtException to
1668 // java.lang.Thread.dispatchUncaughtException
1669 if (uncaught_exception.not_null()) {
1670 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1671 {
1672 EXCEPTION_MARK;
1673 // Check if the method Thread.dispatchUncaughtException() exists. If so
1674 // call it. Otherwise we have an older library without the JSR-166 changes,
1675 // so call ThreadGroup.uncaughtException()
1676 KlassHandle recvrKlass(THREAD, threadObj->klass());
1677 CallInfo callinfo;
1678 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1679 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1680 vmSymbols::dispatchUncaughtException_name(),
1681 vmSymbols::throwable_void_signature(),
1682 KlassHandle(), false, false, THREAD);
1683 CLEAR_PENDING_EXCEPTION;
1684 methodHandle method = callinfo.selected_method();
1685 if (method.not_null()) {
1686 JavaValue result(T_VOID);
1687 JavaCalls::call_virtual(&result,
1688 threadObj, thread_klass,
1689 vmSymbols::dispatchUncaughtException_name(),
1690 vmSymbols::throwable_void_signature(),
1691 uncaught_exception,
1692 THREAD);
1693 } else {
1694 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1695 JavaValue result(T_VOID);
1696 JavaCalls::call_virtual(&result,
1697 group, thread_group,
1698 vmSymbols::uncaughtException_name(),
1699 vmSymbols::thread_throwable_void_signature(),
1700 threadObj, // Arg 1
1701 uncaught_exception, // Arg 2
1702 THREAD);
1703 }
1704 if (HAS_PENDING_EXCEPTION) {
1705 ResourceMark rm(this);
1706 jio_fprintf(defaultStream::error_stream(),
1707 "\nException: %s thrown from the UncaughtExceptionHandler"
1708 " in thread \"%s\"\n",
1709 Klass::cast(pending_exception()->klass())->external_name(),
1710 get_thread_name());
1711 CLEAR_PENDING_EXCEPTION;
1712 }
1713 }
1714 }
1715
1716 // Called before the java thread exit since we want to read info
1717 // from java_lang_Thread object
1718 EVENT_BEGIN(TraceEventThreadEnd, event);
1719 EVENT_COMMIT(event,
1720 EVENT_SET(event, javalangthread, java_lang_Thread::thread_id(this->threadObj())));
1721
1722 // Call after last event on thread
1723 EVENT_THREAD_EXIT(this);
1724
1725 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1726 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1727 // is deprecated anyhow.
1728 { int count = 3;
1729 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1730 EXCEPTION_MARK;
1731 JavaValue result(T_VOID);
1732 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1733 JavaCalls::call_virtual(&result,
1734 threadObj, thread_klass,
1735 vmSymbols::exit_method_name(),
1736 vmSymbols::void_method_signature(),
1737 THREAD);
1738 CLEAR_PENDING_EXCEPTION;
1739 }
1740 }
1741
1742 // notify JVMTI
1743 if (JvmtiExport::should_post_thread_life()) {
1744 JvmtiExport::post_thread_end(this);
1745 }
1746
1747 // We have notified the agents that we are exiting, before we go on,
1748 // we must check for a pending external suspend request and honor it
1749 // in order to not surprise the thread that made the suspend request.
1750 while (true) {
1751 {
1752 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1753 if (!is_external_suspend()) {
1754 set_terminated(_thread_exiting);
1755 ThreadService::current_thread_exiting(this);
1756 break;
1757 }
1758 // Implied else:
1759 // Things get a little tricky here. We have a pending external
1760 // suspend request, but we are holding the SR_lock so we
1761 // can't just self-suspend. So we temporarily drop the lock
1762 // and then self-suspend.
1763 }
1764
1765 ThreadBlockInVM tbivm(this);
1766 java_suspend_self();
1767
1768 // We're done with this suspend request, but we have to loop around
1769 // and check again. Eventually we will get SR_lock without a pending
1770 // external suspend request and will be able to mark ourselves as
1771 // exiting.
1772 }
1773 // no more external suspends are allowed at this point
1774 } else {
1775 // before_exit() has already posted JVMTI THREAD_END events
1776 }
1777
1778 // Notify waiters on thread object. This has to be done after exit() is called
1779 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1780 // group should have the destroyed bit set before waiters are notified).
1781 ensure_join(this);
1782 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1783
1784 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1785 // held by this thread must be released. A detach operation must only
1786 // get here if there are no Java frames on the stack. Therefore, any
1787 // owned monitors at this point MUST be JNI-acquired monitors which are
1788 // pre-inflated and in the monitor cache.
1789 //
1790 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1791 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1792 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1793 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1794 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1795 }
1796
1797 // These things needs to be done while we are still a Java Thread. Make sure that thread
1798 // is in a consistent state, in case GC happens
1799 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1800
1801 if (active_handles() != NULL) {
1802 JNIHandleBlock* block = active_handles();
1803 set_active_handles(NULL);
1804 JNIHandleBlock::release_block(block);
1805 }
1806
1807 if (free_handle_block() != NULL) {
1808 JNIHandleBlock* block = free_handle_block();
1809 set_free_handle_block(NULL);
1810 JNIHandleBlock::release_block(block);
1811 }
1812
1813 // These have to be removed while this is still a valid thread.
1814 remove_stack_guard_pages();
1815
1816 if (UseTLAB) {
1817 tlab().make_parsable(true); // retire TLAB
1818 }
1819
1820 if (JvmtiEnv::environments_might_exist()) {
1821 JvmtiExport::cleanup_thread(this);
1822 }
1823
1824 #ifndef SERIALGC
1825 // We must flush G1-related buffers before removing a thread from
1826 // the list of active threads.
1827 if (UseG1GC) {
1828 flush_barrier_queues();
1829 }
1830 #endif
1831
1832 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1833 Threads::remove(this);
1834 }
1835
1836 #ifndef SERIALGC
1837 // Flush G1-related queues.
1838 void JavaThread::flush_barrier_queues() {
1839 satb_mark_queue().flush();
1840 dirty_card_queue().flush();
1841 }
1842
1843 void JavaThread::initialize_queues() {
1844 assert(!SafepointSynchronize::is_at_safepoint(),
1845 "we should not be at a safepoint");
1846
1847 ObjPtrQueue& satb_queue = satb_mark_queue();
1848 SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
1849 // The SATB queue should have been constructed with its active
1850 // field set to false.
1851 assert(!satb_queue.is_active(), "SATB queue should not be active");
1852 assert(satb_queue.is_empty(), "SATB queue should be empty");
1853 // If we are creating the thread during a marking cycle, we should
1854 // set the active field of the SATB queue to true.
1855 if (satb_queue_set.is_active()) {
1856 satb_queue.set_active(true);
1857 }
1858
1859 DirtyCardQueue& dirty_queue = dirty_card_queue();
1860 // The dirty card queue should have been constructed with its
1861 // active field set to true.
1862 assert(dirty_queue.is_active(), "dirty card queue should be active");
1863 }
1864 #endif // !SERIALGC
1865
1866 void JavaThread::cleanup_failed_attach_current_thread() {
1867 if (get_thread_profiler() != NULL) {
1868 get_thread_profiler()->disengage();
1869 ResourceMark rm;
1870 get_thread_profiler()->print(get_thread_name());
1871 }
1872
1873 if (active_handles() != NULL) {
1874 JNIHandleBlock* block = active_handles();
1875 set_active_handles(NULL);
1876 JNIHandleBlock::release_block(block);
1877 }
1878
1879 if (free_handle_block() != NULL) {
1880 JNIHandleBlock* block = free_handle_block();
1881 set_free_handle_block(NULL);
1882 JNIHandleBlock::release_block(block);
1883 }
1884
1885 // These have to be removed while this is still a valid thread.
1886 remove_stack_guard_pages();
1887
1888 if (UseTLAB) {
1889 tlab().make_parsable(true); // retire TLAB, if any
1890 }
1891
1892 #ifndef SERIALGC
1893 if (UseG1GC) {
1894 flush_barrier_queues();
1895 }
1896 #endif
1897
1898 Threads::remove(this);
1899 delete this;
1900 }
1901
1902
1903
1904
1905 JavaThread* JavaThread::active() {
1906 Thread* thread = ThreadLocalStorage::thread();
1907 assert(thread != NULL, "just checking");
1908 if (thread->is_Java_thread()) {
1909 return (JavaThread*) thread;
1910 } else {
1911 assert(thread->is_VM_thread(), "this must be a vm thread");
1912 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1913 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1914 assert(ret->is_Java_thread(), "must be a Java thread");
1915 return ret;
1916 }
1917 }
1918
1919 bool JavaThread::is_lock_owned(address adr) const {
1920 if (Thread::is_lock_owned(adr)) return true;
1921
1922 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1923 if (chunk->contains(adr)) return true;
1924 }
1925
1926 return false;
1927 }
1928
1929
1930 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1931 chunk->set_next(monitor_chunks());
1932 set_monitor_chunks(chunk);
1933 }
1934
1935 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1936 guarantee(monitor_chunks() != NULL, "must be non empty");
1937 if (monitor_chunks() == chunk) {
1938 set_monitor_chunks(chunk->next());
1939 } else {
1940 MonitorChunk* prev = monitor_chunks();
1941 while (prev->next() != chunk) prev = prev->next();
1942 prev->set_next(chunk->next());
1943 }
1944 }
1945
1946 // JVM support.
1947
1948 // Note: this function shouldn't block if it's called in
1949 // _thread_in_native_trans state (such as from
1950 // check_special_condition_for_native_trans()).
1951 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
1952
1953 if (has_last_Java_frame() && has_async_condition()) {
1954 // If we are at a polling page safepoint (not a poll return)
1955 // then we must defer async exception because live registers
1956 // will be clobbered by the exception path. Poll return is
1957 // ok because the call we a returning from already collides
1958 // with exception handling registers and so there is no issue.
1959 // (The exception handling path kills call result registers but
1960 // this is ok since the exception kills the result anyway).
1961
1962 if (is_at_poll_safepoint()) {
1963 // if the code we are returning to has deoptimized we must defer
1964 // the exception otherwise live registers get clobbered on the
1965 // exception path before deoptimization is able to retrieve them.
1966 //
1967 RegisterMap map(this, false);
1968 frame caller_fr = last_frame().sender(&map);
1969 assert(caller_fr.is_compiled_frame(), "what?");
1970 if (caller_fr.is_deoptimized_frame()) {
1971 if (TraceExceptions) {
1972 ResourceMark rm;
1973 tty->print_cr("deferred async exception at compiled safepoint");
1974 }
1975 return;
1976 }
1977 }
1978 }
1979
1980 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
1981 if (condition == _no_async_condition) {
1982 // Conditions have changed since has_special_runtime_exit_condition()
1983 // was called:
1984 // - if we were here only because of an external suspend request,
1985 // then that was taken care of above (or cancelled) so we are done
1986 // - if we were here because of another async request, then it has
1987 // been cleared between the has_special_runtime_exit_condition()
1988 // and now so again we are done
1989 return;
1990 }
1991
1992 // Check for pending async. exception
1993 if (_pending_async_exception != NULL) {
1994 // Only overwrite an already pending exception, if it is not a threadDeath.
1995 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
1996
1997 // We cannot call Exceptions::_throw(...) here because we cannot block
1998 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1999
2000 if (TraceExceptions) {
2001 ResourceMark rm;
2002 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
2003 if (has_last_Java_frame() ) {
2004 frame f = last_frame();
2005 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
2006 }
2007 tty->print_cr(" of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2008 }
2009 _pending_async_exception = NULL;
2010 clear_has_async_exception();
2011 }
2012 }
2013
2014 if (check_unsafe_error &&
2015 condition == _async_unsafe_access_error && !has_pending_exception()) {
2016 condition = _no_async_condition; // done
2017 switch (thread_state()) {
2018 case _thread_in_vm:
2019 {
2020 JavaThread* THREAD = this;
2021 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2022 }
2023 case _thread_in_native:
2024 {
2025 ThreadInVMfromNative tiv(this);
2026 JavaThread* THREAD = this;
2027 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2028 }
2029 case _thread_in_Java:
2030 {
2031 ThreadInVMfromJava tiv(this);
2032 JavaThread* THREAD = this;
2033 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
2034 }
2035 default:
2036 ShouldNotReachHere();
2037 }
2038 }
2039
2040 assert(condition == _no_async_condition || has_pending_exception() ||
2041 (!check_unsafe_error && condition == _async_unsafe_access_error),
2042 "must have handled the async condition, if no exception");
2043 }
2044
2045 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
2046 //
2047 // Check for pending external suspend. Internal suspend requests do
2048 // not use handle_special_runtime_exit_condition().
2049 // If JNIEnv proxies are allowed, don't self-suspend if the target
2050 // thread is not the current thread. In older versions of jdbx, jdbx
2051 // threads could call into the VM with another thread's JNIEnv so we
2052 // can be here operating on behalf of a suspended thread (4432884).
2053 bool do_self_suspend = is_external_suspend_with_lock();
2054 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
2055 //
2056 // Because thread is external suspended the safepoint code will count
2057 // thread as at a safepoint. This can be odd because we can be here
2058 // as _thread_in_Java which would normally transition to _thread_blocked
2059 // at a safepoint. We would like to mark the thread as _thread_blocked
2060 // before calling java_suspend_self like all other callers of it but
2061 // we must then observe proper safepoint protocol. (We can't leave
2062 // _thread_blocked with a safepoint in progress). However we can be
2063 // here as _thread_in_native_trans so we can't use a normal transition
2064 // constructor/destructor pair because they assert on that type of
2065 // transition. We could do something like:
2066 //
2067 // JavaThreadState state = thread_state();
2068 // set_thread_state(_thread_in_vm);
2069 // {
2070 // ThreadBlockInVM tbivm(this);
2071 // java_suspend_self()
2072 // }
2073 // set_thread_state(_thread_in_vm_trans);
2074 // if (safepoint) block;
2075 // set_thread_state(state);
2076 //
2077 // but that is pretty messy. Instead we just go with the way the
2078 // code has worked before and note that this is the only path to
2079 // java_suspend_self that doesn't put the thread in _thread_blocked
2080 // mode.
2081
2082 frame_anchor()->make_walkable(this);
2083 java_suspend_self();
2084
2085 // We might be here for reasons in addition to the self-suspend request
2086 // so check for other async requests.
2087 }
2088
2089 if (check_asyncs) {
2090 check_and_handle_async_exceptions();
2091 }
2092 }
2093
2094 void JavaThread::send_thread_stop(oop java_throwable) {
2095 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
2096 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
2097 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
2098
2099 // Do not throw asynchronous exceptions against the compiler thread
2100 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
2101 if (is_Compiler_thread()) return;
2102
2103 {
2104 // Actually throw the Throwable against the target Thread - however
2105 // only if there is no thread death exception installed already.
2106 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
2107 // If the topmost frame is a runtime stub, then we are calling into
2108 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
2109 // must deoptimize the caller before continuing, as the compiled exception handler table
2110 // may not be valid
2111 if (has_last_Java_frame()) {
2112 frame f = last_frame();
2113 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
2114 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2115 RegisterMap reg_map(this, UseBiasedLocking);
2116 frame compiled_frame = f.sender(®_map);
2117 if (compiled_frame.can_be_deoptimized()) {
2118 Deoptimization::deoptimize(this, compiled_frame, ®_map);
2119 }
2120 }
2121 }
2122
2123 // Set async. pending exception in thread.
2124 set_pending_async_exception(java_throwable);
2125
2126 if (TraceExceptions) {
2127 ResourceMark rm;
2128 tty->print_cr("Pending Async. exception installed of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2129 }
2130 // for AbortVMOnException flag
2131 NOT_PRODUCT(Exceptions::debug_check_abort(InstanceKlass::cast(_pending_async_exception->klass())->external_name()));
2132 }
2133 }
2134
2135
2136 // Interrupt thread so it will wake up from a potential wait()
2137 Thread::interrupt(this);
2138 }
2139
2140 // External suspension mechanism.
2141 //
2142 // Tell the VM to suspend a thread when ever it knows that it does not hold on
2143 // to any VM_locks and it is at a transition
2144 // Self-suspension will happen on the transition out of the vm.
2145 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
2146 //
2147 // Guarantees on return:
2148 // + Target thread will not execute any new bytecode (that's why we need to
2149 // force a safepoint)
2150 // + Target thread will not enter any new monitors
2151 //
2152 void JavaThread::java_suspend() {
2153 { MutexLocker mu(Threads_lock);
2154 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
2155 return;
2156 }
2157 }
2158
2159 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2160 if (!is_external_suspend()) {
2161 // a racing resume has cancelled us; bail out now
2162 return;
2163 }
2164
2165 // suspend is done
2166 uint32_t debug_bits = 0;
2167 // Warning: is_ext_suspend_completed() may temporarily drop the
2168 // SR_lock to allow the thread to reach a stable thread state if
2169 // it is currently in a transient thread state.
2170 if (is_ext_suspend_completed(false /* !called_by_wait */,
2171 SuspendRetryDelay, &debug_bits) ) {
2172 return;
2173 }
2174 }
2175
2176 VM_ForceSafepoint vm_suspend;
2177 VMThread::execute(&vm_suspend);
2178 }
2179
2180 // Part II of external suspension.
2181 // A JavaThread self suspends when it detects a pending external suspend
2182 // request. This is usually on transitions. It is also done in places
2183 // where continuing to the next transition would surprise the caller,
2184 // e.g., monitor entry.
2185 //
2186 // Returns the number of times that the thread self-suspended.
2187 //
2188 // Note: DO NOT call java_suspend_self() when you just want to block current
2189 // thread. java_suspend_self() is the second stage of cooperative
2190 // suspension for external suspend requests and should only be used
2191 // to complete an external suspend request.
2192 //
2193 int JavaThread::java_suspend_self() {
2194 int ret = 0;
2195
2196 // we are in the process of exiting so don't suspend
2197 if (is_exiting()) {
2198 clear_external_suspend();
2199 return ret;
2200 }
2201
2202 assert(_anchor.walkable() ||
2203 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
2204 "must have walkable stack");
2205
2206 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2207
2208 assert(!this->is_ext_suspended(),
2209 "a thread trying to self-suspend should not already be suspended");
2210
2211 if (this->is_suspend_equivalent()) {
2212 // If we are self-suspending as a result of the lifting of a
2213 // suspend equivalent condition, then the suspend_equivalent
2214 // flag is not cleared until we set the ext_suspended flag so
2215 // that wait_for_ext_suspend_completion() returns consistent
2216 // results.
2217 this->clear_suspend_equivalent();
2218 }
2219
2220 // A racing resume may have cancelled us before we grabbed SR_lock
2221 // above. Or another external suspend request could be waiting for us
2222 // by the time we return from SR_lock()->wait(). The thread
2223 // that requested the suspension may already be trying to walk our
2224 // stack and if we return now, we can change the stack out from under
2225 // it. This would be a "bad thing (TM)" and cause the stack walker
2226 // to crash. We stay self-suspended until there are no more pending
2227 // external suspend requests.
2228 while (is_external_suspend()) {
2229 ret++;
2230 this->set_ext_suspended();
2231
2232 // _ext_suspended flag is cleared by java_resume()
2233 while (is_ext_suspended()) {
2234 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2235 }
2236 }
2237
2238 return ret;
2239 }
2240
2241 #ifdef ASSERT
2242 // verify the JavaThread has not yet been published in the Threads::list, and
2243 // hence doesn't need protection from concurrent access at this stage
2244 void JavaThread::verify_not_published() {
2245 if (!Threads_lock->owned_by_self()) {
2246 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2247 assert( !Threads::includes(this),
2248 "java thread shouldn't have been published yet!");
2249 }
2250 else {
2251 assert( !Threads::includes(this),
2252 "java thread shouldn't have been published yet!");
2253 }
2254 }
2255 #endif
2256
2257 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2258 // progress or when _suspend_flags is non-zero.
2259 // Current thread needs to self-suspend if there is a suspend request and/or
2260 // block if a safepoint is in progress.
2261 // Async exception ISN'T checked.
2262 // Note only the ThreadInVMfromNative transition can call this function
2263 // directly and when thread state is _thread_in_native_trans
2264 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2265 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2266
2267 JavaThread *curJT = JavaThread::current();
2268 bool do_self_suspend = thread->is_external_suspend();
2269
2270 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2271
2272 // If JNIEnv proxies are allowed, don't self-suspend if the target
2273 // thread is not the current thread. In older versions of jdbx, jdbx
2274 // threads could call into the VM with another thread's JNIEnv so we
2275 // can be here operating on behalf of a suspended thread (4432884).
2276 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2277 JavaThreadState state = thread->thread_state();
2278
2279 // We mark this thread_blocked state as a suspend-equivalent so
2280 // that a caller to is_ext_suspend_completed() won't be confused.
2281 // The suspend-equivalent state is cleared by java_suspend_self().
2282 thread->set_suspend_equivalent();
2283
2284 // If the safepoint code sees the _thread_in_native_trans state, it will
2285 // wait until the thread changes to other thread state. There is no
2286 // guarantee on how soon we can obtain the SR_lock and complete the
2287 // self-suspend request. It would be a bad idea to let safepoint wait for
2288 // too long. Temporarily change the state to _thread_blocked to
2289 // let the VM thread know that this thread is ready for GC. The problem
2290 // of changing thread state is that safepoint could happen just after
2291 // java_suspend_self() returns after being resumed, and VM thread will
2292 // see the _thread_blocked state. We must check for safepoint
2293 // after restoring the state and make sure we won't leave while a safepoint
2294 // is in progress.
2295 thread->set_thread_state(_thread_blocked);
2296 thread->java_suspend_self();
2297 thread->set_thread_state(state);
2298 // Make sure new state is seen by VM thread
2299 if (os::is_MP()) {
2300 if (UseMembar) {
2301 // Force a fence between the write above and read below
2302 OrderAccess::fence();
2303 } else {
2304 // Must use this rather than serialization page in particular on Windows
2305 InterfaceSupport::serialize_memory(thread);
2306 }
2307 }
2308 }
2309
2310 if (SafepointSynchronize::do_call_back()) {
2311 // If we are safepointing, then block the caller which may not be
2312 // the same as the target thread (see above).
2313 SafepointSynchronize::block(curJT);
2314 }
2315
2316 if (thread->is_deopt_suspend()) {
2317 thread->clear_deopt_suspend();
2318 RegisterMap map(thread, false);
2319 frame f = thread->last_frame();
2320 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2321 f = f.sender(&map);
2322 }
2323 if (f.id() == thread->must_deopt_id()) {
2324 thread->clear_must_deopt_id();
2325 f.deoptimize(thread);
2326 } else {
2327 fatal("missed deoptimization!");
2328 }
2329 }
2330 }
2331
2332 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2333 // progress or when _suspend_flags is non-zero.
2334 // Current thread needs to self-suspend if there is a suspend request and/or
2335 // block if a safepoint is in progress.
2336 // Also check for pending async exception (not including unsafe access error).
2337 // Note only the native==>VM/Java barriers can call this function and when
2338 // thread state is _thread_in_native_trans.
2339 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2340 check_safepoint_and_suspend_for_native_trans(thread);
2341
2342 if (thread->has_async_exception()) {
2343 // We are in _thread_in_native_trans state, don't handle unsafe
2344 // access error since that may block.
2345 thread->check_and_handle_async_exceptions(false);
2346 }
2347 }
2348
2349 // This is a variant of the normal
2350 // check_special_condition_for_native_trans with slightly different
2351 // semantics for use by critical native wrappers. It does all the
2352 // normal checks but also performs the transition back into
2353 // thread_in_Java state. This is required so that critical natives
2354 // can potentially block and perform a GC if they are the last thread
2355 // exiting the GC_locker.
2356 void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) {
2357 check_special_condition_for_native_trans(thread);
2358
2359 // Finish the transition
2360 thread->set_thread_state(_thread_in_Java);
2361
2362 if (thread->do_critical_native_unlock()) {
2363 ThreadInVMfromJavaNoAsyncException tiv(thread);
2364 GC_locker::unlock_critical(thread);
2365 thread->clear_critical_native_unlock();
2366 }
2367 }
2368
2369 // We need to guarantee the Threads_lock here, since resumes are not
2370 // allowed during safepoint synchronization
2371 // Can only resume from an external suspension
2372 void JavaThread::java_resume() {
2373 assert_locked_or_safepoint(Threads_lock);
2374
2375 // Sanity check: thread is gone, has started exiting or the thread
2376 // was not externally suspended.
2377 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2378 return;
2379 }
2380
2381 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2382
2383 clear_external_suspend();
2384
2385 if (is_ext_suspended()) {
2386 clear_ext_suspended();
2387 SR_lock()->notify_all();
2388 }
2389 }
2390
2391 void JavaThread::create_stack_guard_pages() {
2392 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2393 address low_addr = stack_base() - stack_size();
2394 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2395
2396 int allocate = os::allocate_stack_guard_pages();
2397 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2398
2399 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
2400 warning("Attempt to allocate stack guard pages failed.");
2401 return;
2402 }
2403
2404 if (os::guard_memory((char *) low_addr, len)) {
2405 _stack_guard_state = stack_guard_enabled;
2406 } else {
2407 warning("Attempt to protect stack guard pages failed.");
2408 if (os::uncommit_memory((char *) low_addr, len)) {
2409 warning("Attempt to deallocate stack guard pages failed.");
2410 }
2411 }
2412 }
2413
2414 void JavaThread::remove_stack_guard_pages() {
2415 if (_stack_guard_state == stack_guard_unused) return;
2416 address low_addr = stack_base() - stack_size();
2417 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2418
2419 if (os::allocate_stack_guard_pages()) {
2420 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2421 _stack_guard_state = stack_guard_unused;
2422 } else {
2423 warning("Attempt to deallocate stack guard pages failed.");
2424 }
2425 } else {
2426 if (_stack_guard_state == stack_guard_unused) return;
2427 if (os::unguard_memory((char *) low_addr, len)) {
2428 _stack_guard_state = stack_guard_unused;
2429 } else {
2430 warning("Attempt to unprotect stack guard pages failed.");
2431 }
2432 }
2433 }
2434
2435 void JavaThread::enable_stack_yellow_zone() {
2436 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2437 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2438
2439 // The base notation is from the stacks point of view, growing downward.
2440 // We need to adjust it to work correctly with guard_memory()
2441 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2442
2443 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2444 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2445
2446 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2447 _stack_guard_state = stack_guard_enabled;
2448 } else {
2449 warning("Attempt to guard stack yellow zone failed.");
2450 }
2451 enable_register_stack_guard();
2452 }
2453
2454 void JavaThread::disable_stack_yellow_zone() {
2455 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2456 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2457
2458 // Simply return if called for a thread that does not use guard pages.
2459 if (_stack_guard_state == stack_guard_unused) return;
2460
2461 // The base notation is from the stacks point of view, growing downward.
2462 // We need to adjust it to work correctly with guard_memory()
2463 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2464
2465 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2466 _stack_guard_state = stack_guard_yellow_disabled;
2467 } else {
2468 warning("Attempt to unguard stack yellow zone failed.");
2469 }
2470 disable_register_stack_guard();
2471 }
2472
2473 void JavaThread::enable_stack_red_zone() {
2474 // The base notation is from the stacks point of view, growing downward.
2475 // We need to adjust it to work correctly with guard_memory()
2476 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2477 address base = stack_red_zone_base() - stack_red_zone_size();
2478
2479 guarantee(base < stack_base(),"Error calculating stack red zone");
2480 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2481
2482 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2483 warning("Attempt to guard stack red zone failed.");
2484 }
2485 }
2486
2487 void JavaThread::disable_stack_red_zone() {
2488 // The base notation is from the stacks point of view, growing downward.
2489 // We need to adjust it to work correctly with guard_memory()
2490 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2491 address base = stack_red_zone_base() - stack_red_zone_size();
2492 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2493 warning("Attempt to unguard stack red zone failed.");
2494 }
2495 }
2496
2497 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2498 // ignore is there is no stack
2499 if (!has_last_Java_frame()) return;
2500 // traverse the stack frames. Starts from top frame.
2501 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2502 frame* fr = fst.current();
2503 f(fr, fst.register_map());
2504 }
2505 }
2506
2507
2508 #ifndef PRODUCT
2509 // Deoptimization
2510 // Function for testing deoptimization
2511 void JavaThread::deoptimize() {
2512 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2513 StackFrameStream fst(this, UseBiasedLocking);
2514 bool deopt = false; // Dump stack only if a deopt actually happens.
2515 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2516 // Iterate over all frames in the thread and deoptimize
2517 for(; !fst.is_done(); fst.next()) {
2518 if(fst.current()->can_be_deoptimized()) {
2519
2520 if (only_at) {
2521 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2522 // consists of comma or carriage return separated numbers so
2523 // search for the current bci in that string.
2524 address pc = fst.current()->pc();
2525 nmethod* nm = (nmethod*) fst.current()->cb();
2526 ScopeDesc* sd = nm->scope_desc_at( pc);
2527 char buffer[8];
2528 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2529 size_t len = strlen(buffer);
2530 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2531 while (found != NULL) {
2532 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2533 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2534 // Check that the bci found is bracketed by terminators.
2535 break;
2536 }
2537 found = strstr(found + 1, buffer);
2538 }
2539 if (!found) {
2540 continue;
2541 }
2542 }
2543
2544 if (DebugDeoptimization && !deopt) {
2545 deopt = true; // One-time only print before deopt
2546 tty->print_cr("[BEFORE Deoptimization]");
2547 trace_frames();
2548 trace_stack();
2549 }
2550 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2551 }
2552 }
2553
2554 if (DebugDeoptimization && deopt) {
2555 tty->print_cr("[AFTER Deoptimization]");
2556 trace_frames();
2557 }
2558 }
2559
2560
2561 // Make zombies
2562 void JavaThread::make_zombies() {
2563 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2564 if (fst.current()->can_be_deoptimized()) {
2565 // it is a Java nmethod
2566 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2567 nm->make_not_entrant();
2568 }
2569 }
2570 }
2571 #endif // PRODUCT
2572
2573
2574 void JavaThread::deoptimized_wrt_marked_nmethods() {
2575 if (!has_last_Java_frame()) return;
2576 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2577 StackFrameStream fst(this, UseBiasedLocking);
2578 for(; !fst.is_done(); fst.next()) {
2579 if (fst.current()->should_be_deoptimized()) {
2580 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2581 }
2582 }
2583 }
2584
2585
2586 // GC support
2587 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2588
2589 void JavaThread::gc_epilogue() {
2590 frames_do(frame_gc_epilogue);
2591 }
2592
2593
2594 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2595
2596 void JavaThread::gc_prologue() {
2597 frames_do(frame_gc_prologue);
2598 }
2599
2600 // If the caller is a NamedThread, then remember, in the current scope,
2601 // the given JavaThread in its _processed_thread field.
2602 class RememberProcessedThread: public StackObj {
2603 NamedThread* _cur_thr;
2604 public:
2605 RememberProcessedThread(JavaThread* jthr) {
2606 Thread* thread = Thread::current();
2607 if (thread->is_Named_thread()) {
2608 _cur_thr = (NamedThread *)thread;
2609 _cur_thr->set_processed_thread(jthr);
2610 } else {
2611 _cur_thr = NULL;
2612 }
2613 }
2614
2615 ~RememberProcessedThread() {
2616 if (_cur_thr) {
2617 _cur_thr->set_processed_thread(NULL);
2618 }
2619 }
2620 };
2621
2622 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2623 // Verify that the deferred card marks have been flushed.
2624 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2625
2626 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2627 // since there may be more than one thread using each ThreadProfiler.
2628
2629 // Traverse the GCHandles
2630 Thread::oops_do(f, cf);
2631
2632 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2633 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2634
2635 if (has_last_Java_frame()) {
2636 // Record JavaThread to GC thread
2637 RememberProcessedThread rpt(this);
2638
2639 // Traverse the privileged stack
2640 if (_privileged_stack_top != NULL) {
2641 _privileged_stack_top->oops_do(f);
2642 }
2643
2644 // traverse the registered growable array
2645 if (_array_for_gc != NULL) {
2646 for (int index = 0; index < _array_for_gc->length(); index++) {
2647 f->do_oop(_array_for_gc->adr_at(index));
2648 }
2649 }
2650
2651 // Traverse the monitor chunks
2652 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2653 chunk->oops_do(f);
2654 }
2655
2656 // Traverse the execution stack
2657 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2658 fst.current()->oops_do(f, cf, fst.register_map());
2659 }
2660 }
2661
2662 // callee_target is never live across a gc point so NULL it here should
2663 // it still contain a methdOop.
2664
2665 set_callee_target(NULL);
2666
2667 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2668 // If we have deferred set_locals there might be oops waiting to be
2669 // written
2670 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2671 if (list != NULL) {
2672 for (int i = 0; i < list->length(); i++) {
2673 list->at(i)->oops_do(f);
2674 }
2675 }
2676
2677 // Traverse instance variables at the end since the GC may be moving things
2678 // around using this function
2679 f->do_oop((oop*) &_threadObj);
2680 f->do_oop((oop*) &_vm_result);
2681 f->do_oop((oop*) &_exception_oop);
2682 f->do_oop((oop*) &_pending_async_exception);
2683
2684 if (jvmti_thread_state() != NULL) {
2685 jvmti_thread_state()->oops_do(f);
2686 }
2687 }
2688
2689 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2690 Thread::nmethods_do(cf); // (super method is a no-op)
2691
2692 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2693 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2694
2695 if (has_last_Java_frame()) {
2696 // Traverse the execution stack
2697 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2698 fst.current()->nmethods_do(cf);
2699 }
2700 }
2701 }
2702
2703 void JavaThread::metadata_do(void f(Metadata*)) {
2704 Thread::metadata_do(f);
2705 if (has_last_Java_frame()) {
2706 // Traverse the execution stack to call f() on the methods in the stack
2707 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2708 fst.current()->metadata_do(f);
2709 }
2710 } else if (is_Compiler_thread()) {
2711 // need to walk ciMetadata in current compile tasks to keep alive.
2712 CompilerThread* ct = (CompilerThread*)this;
2713 if (ct->env() != NULL) {
2714 ct->env()->metadata_do(f);
2715 }
2716 }
2717 }
2718
2719 // Printing
2720 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2721 switch (_thread_state) {
2722 case _thread_uninitialized: return "_thread_uninitialized";
2723 case _thread_new: return "_thread_new";
2724 case _thread_new_trans: return "_thread_new_trans";
2725 case _thread_in_native: return "_thread_in_native";
2726 case _thread_in_native_trans: return "_thread_in_native_trans";
2727 case _thread_in_vm: return "_thread_in_vm";
2728 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2729 case _thread_in_Java: return "_thread_in_Java";
2730 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2731 case _thread_blocked: return "_thread_blocked";
2732 case _thread_blocked_trans: return "_thread_blocked_trans";
2733 default: return "unknown thread state";
2734 }
2735 }
2736
2737 #ifndef PRODUCT
2738 void JavaThread::print_thread_state_on(outputStream *st) const {
2739 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2740 };
2741 void JavaThread::print_thread_state() const {
2742 print_thread_state_on(tty);
2743 };
2744 #endif // PRODUCT
2745
2746 // Called by Threads::print() for VM_PrintThreads operation
2747 void JavaThread::print_on(outputStream *st) const {
2748 st->print("\"%s\" ", get_thread_name());
2749 oop thread_oop = threadObj();
2750 if (thread_oop != NULL) {
2751 st->print("#" INT64_FORMAT " ", java_lang_Thread::thread_id(thread_oop));
2752 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2753 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2754 }
2755 Thread::print_on(st);
2756 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2757 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2758 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2759 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2760 }
2761 #ifndef PRODUCT
2762 print_thread_state_on(st);
2763 _safepoint_state->print_on(st);
2764 #endif // PRODUCT
2765 }
2766
2767 // Called by fatal error handler. The difference between this and
2768 // JavaThread::print() is that we can't grab lock or allocate memory.
2769 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2770 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2771 oop thread_obj = threadObj();
2772 if (thread_obj != NULL) {
2773 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2774 }
2775 st->print(" [");
2776 st->print("%s", _get_thread_state_name(_thread_state));
2777 if (osthread()) {
2778 st->print(", id=%d", osthread()->thread_id());
2779 }
2780 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2781 _stack_base - _stack_size, _stack_base);
2782 st->print("]");
2783 return;
2784 }
2785
2786 // Verification
2787
2788 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2789
2790 void JavaThread::verify() {
2791 // Verify oops in the thread.
2792 oops_do(&VerifyOopClosure::verify_oop, NULL);
2793
2794 // Verify the stack frames.
2795 frames_do(frame_verify);
2796 }
2797
2798 // CR 6300358 (sub-CR 2137150)
2799 // Most callers of this method assume that it can't return NULL but a
2800 // thread may not have a name whilst it is in the process of attaching to
2801 // the VM - see CR 6412693, and there are places where a JavaThread can be
2802 // seen prior to having it's threadObj set (eg JNI attaching threads and
2803 // if vm exit occurs during initialization). These cases can all be accounted
2804 // for such that this method never returns NULL.
2805 const char* JavaThread::get_thread_name() const {
2806 #ifdef ASSERT
2807 // early safepoints can hit while current thread does not yet have TLS
2808 if (!SafepointSynchronize::is_at_safepoint()) {
2809 Thread *cur = Thread::current();
2810 if (!(cur->is_Java_thread() && cur == this)) {
2811 // Current JavaThreads are allowed to get their own name without
2812 // the Threads_lock.
2813 assert_locked_or_safepoint(Threads_lock);
2814 }
2815 }
2816 #endif // ASSERT
2817 return get_thread_name_string();
2818 }
2819
2820 // Returns a non-NULL representation of this thread's name, or a suitable
2821 // descriptive string if there is no set name
2822 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2823 const char* name_str;
2824 oop thread_obj = threadObj();
2825 if (thread_obj != NULL) {
2826 typeArrayOop name = java_lang_Thread::name(thread_obj);
2827 if (name != NULL) {
2828 if (buf == NULL) {
2829 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2830 }
2831 else {
2832 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2833 }
2834 }
2835 else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2836 name_str = "<no-name - thread is attaching>";
2837 }
2838 else {
2839 name_str = Thread::name();
2840 }
2841 }
2842 else {
2843 name_str = Thread::name();
2844 }
2845 assert(name_str != NULL, "unexpected NULL thread name");
2846 return name_str;
2847 }
2848
2849
2850 const char* JavaThread::get_threadgroup_name() const {
2851 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2852 oop thread_obj = threadObj();
2853 if (thread_obj != NULL) {
2854 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2855 if (thread_group != NULL) {
2856 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2857 // ThreadGroup.name can be null
2858 if (name != NULL) {
2859 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2860 return str;
2861 }
2862 }
2863 }
2864 return NULL;
2865 }
2866
2867 const char* JavaThread::get_parent_name() const {
2868 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2869 oop thread_obj = threadObj();
2870 if (thread_obj != NULL) {
2871 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2872 if (thread_group != NULL) {
2873 oop parent = java_lang_ThreadGroup::parent(thread_group);
2874 if (parent != NULL) {
2875 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2876 // ThreadGroup.name can be null
2877 if (name != NULL) {
2878 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2879 return str;
2880 }
2881 }
2882 }
2883 }
2884 return NULL;
2885 }
2886
2887 ThreadPriority JavaThread::java_priority() const {
2888 oop thr_oop = threadObj();
2889 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2890 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2891 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2892 return priority;
2893 }
2894
2895 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2896
2897 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2898 // Link Java Thread object <-> C++ Thread
2899
2900 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2901 // and put it into a new Handle. The Handle "thread_oop" can then
2902 // be used to pass the C++ thread object to other methods.
2903
2904 // Set the Java level thread object (jthread) field of the
2905 // new thread (a JavaThread *) to C++ thread object using the
2906 // "thread_oop" handle.
2907
2908 // Set the thread field (a JavaThread *) of the
2909 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2910
2911 Handle thread_oop(Thread::current(),
2912 JNIHandles::resolve_non_null(jni_thread));
2913 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
2914 "must be initialized");
2915 set_threadObj(thread_oop());
2916 java_lang_Thread::set_thread(thread_oop(), this);
2917
2918 if (prio == NoPriority) {
2919 prio = java_lang_Thread::priority(thread_oop());
2920 assert(prio != NoPriority, "A valid priority should be present");
2921 }
2922
2923 // Push the Java priority down to the native thread; needs Threads_lock
2924 Thread::set_priority(this, prio);
2925
2926 // Add the new thread to the Threads list and set it in motion.
2927 // We must have threads lock in order to call Threads::add.
2928 // It is crucial that we do not block before the thread is
2929 // added to the Threads list for if a GC happens, then the java_thread oop
2930 // will not be visited by GC.
2931 Threads::add(this);
2932 }
2933
2934 oop JavaThread::current_park_blocker() {
2935 // Support for JSR-166 locks
2936 oop thread_oop = threadObj();
2937 if (thread_oop != NULL &&
2938 JDK_Version::current().supports_thread_park_blocker()) {
2939 return java_lang_Thread::park_blocker(thread_oop);
2940 }
2941 return NULL;
2942 }
2943
2944
2945 void JavaThread::print_stack_on(outputStream* st) {
2946 if (!has_last_Java_frame()) return;
2947 ResourceMark rm;
2948 HandleMark hm;
2949
2950 RegisterMap reg_map(this);
2951 vframe* start_vf = last_java_vframe(®_map);
2952 int count = 0;
2953 for (vframe* f = start_vf; f; f = f->sender() ) {
2954 if (f->is_java_frame()) {
2955 javaVFrame* jvf = javaVFrame::cast(f);
2956 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2957
2958 // Print out lock information
2959 if (JavaMonitorsInStackTrace) {
2960 jvf->print_lock_info_on(st, count);
2961 }
2962 } else {
2963 // Ignore non-Java frames
2964 }
2965
2966 // Bail-out case for too deep stacks
2967 count++;
2968 if (MaxJavaStackTraceDepth == count) return;
2969 }
2970 }
2971
2972
2973 // JVMTI PopFrame support
2974 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2975 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2976 if (in_bytes(size_in_bytes) != 0) {
2977 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
2978 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2979 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2980 }
2981 }
2982
2983 void* JavaThread::popframe_preserved_args() {
2984 return _popframe_preserved_args;
2985 }
2986
2987 ByteSize JavaThread::popframe_preserved_args_size() {
2988 return in_ByteSize(_popframe_preserved_args_size);
2989 }
2990
2991 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2992 int sz = in_bytes(popframe_preserved_args_size());
2993 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2994 return in_WordSize(sz / wordSize);
2995 }
2996
2997 void JavaThread::popframe_free_preserved_args() {
2998 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2999 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args, mtThread);
3000 _popframe_preserved_args = NULL;
3001 _popframe_preserved_args_size = 0;
3002 }
3003
3004 #ifndef PRODUCT
3005
3006 void JavaThread::trace_frames() {
3007 tty->print_cr("[Describe stack]");
3008 int frame_no = 1;
3009 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
3010 tty->print(" %d. ", frame_no++);
3011 fst.current()->print_value_on(tty,this);
3012 tty->cr();
3013 }
3014 }
3015
3016 class PrintAndVerifyOopClosure: public OopClosure {
3017 protected:
3018 template <class T> inline void do_oop_work(T* p) {
3019 oop obj = oopDesc::load_decode_heap_oop(p);
3020 if (obj == NULL) return;
3021 tty->print(INTPTR_FORMAT ": ", p);
3022 if (obj->is_oop_or_null()) {
3023 if (obj->is_objArray()) {
3024 tty->print_cr("valid objArray: " INTPTR_FORMAT, (oopDesc*) obj);
3025 } else {
3026 obj->print();
3027 }
3028 } else {
3029 tty->print_cr("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj);
3030 }
3031 tty->cr();
3032 }
3033 public:
3034 virtual void do_oop(oop* p) { do_oop_work(p); }
3035 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
3036 };
3037
3038
3039 static void oops_print(frame* f, const RegisterMap *map) {
3040 PrintAndVerifyOopClosure print;
3041 f->print_value();
3042 f->oops_do(&print, NULL, (RegisterMap*)map);
3043 }
3044
3045 // Print our all the locations that contain oops and whether they are
3046 // valid or not. This useful when trying to find the oldest frame
3047 // where an oop has gone bad since the frame walk is from youngest to
3048 // oldest.
3049 void JavaThread::trace_oops() {
3050 tty->print_cr("[Trace oops]");
3051 frames_do(oops_print);
3052 }
3053
3054
3055 #ifdef ASSERT
3056 // Print or validate the layout of stack frames
3057 void JavaThread::print_frame_layout(int depth, bool validate_only) {
3058 ResourceMark rm;
3059 PRESERVE_EXCEPTION_MARK;
3060 FrameValues values;
3061 int frame_no = 0;
3062 for(StackFrameStream fst(this, false); !fst.is_done(); fst.next()) {
3063 fst.current()->describe(values, ++frame_no);
3064 if (depth == frame_no) break;
3065 }
3066 if (validate_only) {
3067 values.validate();
3068 } else {
3069 tty->print_cr("[Describe stack layout]");
3070 values.print(this);
3071 }
3072 }
3073 #endif
3074
3075 void JavaThread::trace_stack_from(vframe* start_vf) {
3076 ResourceMark rm;
3077 int vframe_no = 1;
3078 for (vframe* f = start_vf; f; f = f->sender() ) {
3079 if (f->is_java_frame()) {
3080 javaVFrame::cast(f)->print_activation(vframe_no++);
3081 } else {
3082 f->print();
3083 }
3084 if (vframe_no > StackPrintLimit) {
3085 tty->print_cr("...<more frames>...");
3086 return;
3087 }
3088 }
3089 }
3090
3091
3092 void JavaThread::trace_stack() {
3093 if (!has_last_Java_frame()) return;
3094 ResourceMark rm;
3095 HandleMark hm;
3096 RegisterMap reg_map(this);
3097 trace_stack_from(last_java_vframe(®_map));
3098 }
3099
3100
3101 #endif // PRODUCT
3102
3103
3104 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
3105 assert(reg_map != NULL, "a map must be given");
3106 frame f = last_frame();
3107 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
3108 if (vf->is_java_frame()) return javaVFrame::cast(vf);
3109 }
3110 return NULL;
3111 }
3112
3113
3114 Klass* JavaThread::security_get_caller_class(int depth) {
3115 vframeStream vfst(this);
3116 vfst.security_get_caller_frame(depth);
3117 if (!vfst.at_end()) {
3118 return vfst.method()->method_holder();
3119 }
3120 return NULL;
3121 }
3122
3123 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
3124 assert(thread->is_Compiler_thread(), "must be compiler thread");
3125 CompileBroker::compiler_thread_loop();
3126 }
3127
3128 // Create a CompilerThread
3129 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
3130 : JavaThread(&compiler_thread_entry) {
3131 _env = NULL;
3132 _log = NULL;
3133 _task = NULL;
3134 _queue = queue;
3135 _counters = counters;
3136 _buffer_blob = NULL;
3137 _scanned_nmethod = NULL;
3138
3139 #ifndef PRODUCT
3140 _ideal_graph_printer = NULL;
3141 #endif
3142 }
3143
3144 void CompilerThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3145 JavaThread::oops_do(f, cf);
3146 if (_scanned_nmethod != NULL && cf != NULL) {
3147 // Safepoints can occur when the sweeper is scanning an nmethod so
3148 // process it here to make sure it isn't unloaded in the middle of
3149 // a scan.
3150 cf->do_code_blob(_scanned_nmethod);
3151 }
3152 }
3153
3154 // ======= Threads ========
3155
3156 // The Threads class links together all active threads, and provides
3157 // operations over all threads. It is protected by its own Mutex
3158 // lock, which is also used in other contexts to protect thread
3159 // operations from having the thread being operated on from exiting
3160 // and going away unexpectedly (e.g., safepoint synchronization)
3161
3162 JavaThread* Threads::_thread_list = NULL;
3163 int Threads::_number_of_threads = 0;
3164 int Threads::_number_of_non_daemon_threads = 0;
3165 int Threads::_return_code = 0;
3166 size_t JavaThread::_stack_size_at_create = 0;
3167 #ifdef ASSERT
3168 bool Threads::_vm_complete = false;
3169 #endif
3170
3171 // All JavaThreads
3172 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
3173
3174 void os_stream();
3175
3176 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
3177 void Threads::threads_do(ThreadClosure* tc) {
3178 assert_locked_or_safepoint(Threads_lock);
3179 // ALL_JAVA_THREADS iterates through all JavaThreads
3180 ALL_JAVA_THREADS(p) {
3181 tc->do_thread(p);
3182 }
3183 // Someday we could have a table or list of all non-JavaThreads.
3184 // For now, just manually iterate through them.
3185 tc->do_thread(VMThread::vm_thread());
3186 Universe::heap()->gc_threads_do(tc);
3187 WatcherThread *wt = WatcherThread::watcher_thread();
3188 // Strictly speaking, the following NULL check isn't sufficient to make sure
3189 // the data for WatcherThread is still valid upon being examined. However,
3190 // considering that WatchThread terminates when the VM is on the way to
3191 // exit at safepoint, the chance of the above is extremely small. The right
3192 // way to prevent termination of WatcherThread would be to acquire
3193 // Terminator_lock, but we can't do that without violating the lock rank
3194 // checking in some cases.
3195 if (wt != NULL)
3196 tc->do_thread(wt);
3197
3198 // If CompilerThreads ever become non-JavaThreads, add them here
3199 }
3200
3201 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
3202
3203 extern void JDK_Version_init();
3204
3205 // Check version
3206 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
3207
3208 // Initialize the output stream module
3209 ostream_init();
3210
3211 // Process java launcher properties.
3212 Arguments::process_sun_java_launcher_properties(args);
3213
3214 // Initialize the os module before using TLS
3215 os::init();
3216
3217 // Initialize system properties.
3218 Arguments::init_system_properties();
3219
3220 // So that JDK version can be used as a discrimintor when parsing arguments
3221 JDK_Version_init();
3222
3223 // Update/Initialize System properties after JDK version number is known
3224 Arguments::init_version_specific_system_properties();
3225
3226 // Parse arguments
3227 jint parse_result = Arguments::parse(args);
3228 if (parse_result != JNI_OK) return parse_result;
3229
3230 if (PauseAtStartup) {
3231 os::pause();
3232 }
3233
3234 #ifndef USDT2
3235 HS_DTRACE_PROBE(hotspot, vm__init__begin);
3236 #else /* USDT2 */
3237 HOTSPOT_VM_INIT_BEGIN();
3238 #endif /* USDT2 */
3239
3240 // Record VM creation timing statistics
3241 TraceVmCreationTime create_vm_timer;
3242 create_vm_timer.start();
3243
3244 // Timing (must come after argument parsing)
3245 TraceTime timer("Create VM", TraceStartupTime);
3246
3247 // Initialize the os module after parsing the args
3248 jint os_init_2_result = os::init_2();
3249 if (os_init_2_result != JNI_OK) return os_init_2_result;
3250
3251 // intialize TLS
3252 ThreadLocalStorage::init();
3253
3254 // Bootstrap native memory tracking, so it can start recording memory
3255 // activities before worker thread is started. This is the first phase
3256 // of bootstrapping, VM is currently running in single-thread mode.
3257 MemTracker::bootstrap_single_thread();
3258
3259 // Initialize output stream logging
3260 ostream_init_log();
3261
3262 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
3263 // Must be before create_vm_init_agents()
3264 if (Arguments::init_libraries_at_startup()) {
3265 convert_vm_init_libraries_to_agents();
3266 }
3267
3268 // Launch -agentlib/-agentpath and converted -Xrun agents
3269 if (Arguments::init_agents_at_startup()) {
3270 create_vm_init_agents();
3271 }
3272
3273 // Initialize Threads state
3274 _thread_list = NULL;
3275 _number_of_threads = 0;
3276 _number_of_non_daemon_threads = 0;
3277
3278 // Initialize global data structures and create system classes in heap
3279 vm_init_globals();
3280
3281 // Attach the main thread to this os thread
3282 JavaThread* main_thread = new JavaThread();
3283 main_thread->set_thread_state(_thread_in_vm);
3284 // must do this before set_active_handles and initialize_thread_local_storage
3285 // Note: on solaris initialize_thread_local_storage() will (indirectly)
3286 // change the stack size recorded here to one based on the java thread
3287 // stacksize. This adjusted size is what is used to figure the placement
3288 // of the guard pages.
3289 main_thread->record_stack_base_and_size();
3290 main_thread->initialize_thread_local_storage();
3291
3292 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
3293
3294 if (!main_thread->set_as_starting_thread()) {
3295 vm_shutdown_during_initialization(
3296 "Failed necessary internal allocation. Out of swap space");
3297 delete main_thread;
3298 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3299 return JNI_ENOMEM;
3300 }
3301
3302 // Enable guard page *after* os::create_main_thread(), otherwise it would
3303 // crash Linux VM, see notes in os_linux.cpp.
3304 main_thread->create_stack_guard_pages();
3305
3306 // Initialize Java-Level synchronization subsystem
3307 ObjectMonitor::Initialize() ;
3308
3309 // Second phase of bootstrapping, VM is about entering multi-thread mode
3310 MemTracker::bootstrap_multi_thread();
3311
3312 // Initialize global modules
3313 jint status = init_globals();
3314 if (status != JNI_OK) {
3315 delete main_thread;
3316 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3317 return status;
3318 }
3319
3320 // Should be done after the heap is fully created
3321 main_thread->cache_global_variables();
3322
3323 HandleMark hm;
3324
3325 { MutexLocker mu(Threads_lock);
3326 Threads::add(main_thread);
3327 }
3328
3329 // Any JVMTI raw monitors entered in onload will transition into
3330 // real raw monitor. VM is setup enough here for raw monitor enter.
3331 JvmtiExport::transition_pending_onload_raw_monitors();
3332
3333 if (VerifyBeforeGC &&
3334 Universe::heap()->total_collections() >= VerifyGCStartAt) {
3335 Universe::heap()->prepare_for_verify();
3336 Universe::verify(); // make sure we're starting with a clean slate
3337 }
3338
3339 // Fully start NMT
3340 MemTracker::start();
3341
3342 // Create the VMThread
3343 { TraceTime timer("Start VMThread", TraceStartupTime);
3344 VMThread::create();
3345 Thread* vmthread = VMThread::vm_thread();
3346
3347 if (!os::create_thread(vmthread, os::vm_thread))
3348 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
3349
3350 // Wait for the VM thread to become ready, and VMThread::run to initialize
3351 // Monitors can have spurious returns, must always check another state flag
3352 {
3353 MutexLocker ml(Notify_lock);
3354 os::start_thread(vmthread);
3355 while (vmthread->active_handles() == NULL) {
3356 Notify_lock->wait();
3357 }
3358 }
3359 }
3360
3361 assert (Universe::is_fully_initialized(), "not initialized");
3362 EXCEPTION_MARK;
3363
3364 // At this point, the Universe is initialized, but we have not executed
3365 // any byte code. Now is a good time (the only time) to dump out the
3366 // internal state of the JVM for sharing.
3367 if (DumpSharedSpaces) {
3368 MetaspaceShared::preload_and_dump(CHECK_0);
3369 ShouldNotReachHere();
3370 }
3371
3372 // Always call even when there are not JVMTI environments yet, since environments
3373 // may be attached late and JVMTI must track phases of VM execution
3374 JvmtiExport::enter_start_phase();
3375
3376 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3377 JvmtiExport::post_vm_start();
3378
3379 {
3380 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3381
3382 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3383 create_vm_init_libraries();
3384 }
3385
3386 if (InitializeJavaLangString) {
3387 initialize_class(vmSymbols::java_lang_String(), CHECK_0);
3388 } else {
3389 warning("java.lang.String not initialized");
3390 }
3391
3392 if (AggressiveOpts) {
3393 {
3394 // Forcibly initialize java/util/HashMap and mutate the private
3395 // static final "frontCacheEnabled" field before we start creating instances
3396 #ifdef ASSERT
3397 Klass* tmp_k = SystemDictionary::find(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3398 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
3399 #endif
3400 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3401 KlassHandle k = KlassHandle(THREAD, k_o);
3402 guarantee(k.not_null(), "Must find java/util/HashMap");
3403 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3404 ik->initialize(CHECK_0);
3405 fieldDescriptor fd;
3406 // Possible we might not find this field; if so, don't break
3407 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3408 k()->java_mirror()->bool_field_put(fd.offset(), true);
3409 }
3410 }
3411
3412 if (UseStringCache) {
3413 // Forcibly initialize java/lang/StringValue and mutate the private
3414 // static final "stringCacheEnabled" field before we start creating instances
3415 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3416 // Possible that StringValue isn't present: if so, silently don't break
3417 if (k_o != NULL) {
3418 KlassHandle k = KlassHandle(THREAD, k_o);
3419 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3420 ik->initialize(CHECK_0);
3421 fieldDescriptor fd;
3422 // Possible we might not find this field: if so, silently don't break
3423 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3424 k()->java_mirror()->bool_field_put(fd.offset(), true);
3425 }
3426 }
3427 }
3428 }
3429
3430 // Initialize java_lang.System (needed before creating the thread)
3431 if (InitializeJavaLangSystem) {
3432 initialize_class(vmSymbols::java_lang_System(), CHECK_0);
3433 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK_0);
3434 Handle thread_group = create_initial_thread_group(CHECK_0);
3435 Universe::set_main_thread_group(thread_group());
3436 initialize_class(vmSymbols::java_lang_Thread(), CHECK_0);
3437 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3438 main_thread->set_threadObj(thread_object);
3439 // Set thread status to running since main thread has
3440 // been started and running.
3441 java_lang_Thread::set_thread_status(thread_object,
3442 java_lang_Thread::RUNNABLE);
3443
3444 // The VM preresolve methods to these classes. Make sure that get initialized
3445 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK_0);
3446 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK_0);
3447 // The VM creates & returns objects of this class. Make sure it's initialized.
3448 initialize_class(vmSymbols::java_lang_Class(), CHECK_0);
3449 call_initializeSystemClass(CHECK_0);
3450
3451 // get the Java runtime name after java.lang.System is initialized
3452 JDK_Version::set_runtime_name(get_java_runtime_name(THREAD));
3453 } else {
3454 warning("java.lang.System not initialized");
3455 }
3456
3457 // an instance of OutOfMemory exception has been allocated earlier
3458 if (InitializeJavaLangExceptionsErrors) {
3459 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK_0);
3460 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK_0);
3461 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK_0);
3462 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK_0);
3463 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK_0);
3464 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK_0);
3465 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK_0);
3466 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK_0);
3467 } else {
3468 warning("java.lang.OutOfMemoryError has not been initialized");
3469 warning("java.lang.NullPointerException has not been initialized");
3470 warning("java.lang.ClassCastException has not been initialized");
3471 warning("java.lang.ArrayStoreException has not been initialized");
3472 warning("java.lang.ArithmeticException has not been initialized");
3473 warning("java.lang.StackOverflowError has not been initialized");
3474 warning("java.lang.IllegalArgumentException has not been initialized");
3475 }
3476 }
3477
3478 // See : bugid 4211085.
3479 // Background : the static initializer of java.lang.Compiler tries to read
3480 // property"java.compiler" and read & write property "java.vm.info".
3481 // When a security manager is installed through the command line
3482 // option "-Djava.security.manager", the above properties are not
3483 // readable and the static initializer for java.lang.Compiler fails
3484 // resulting in a NoClassDefFoundError. This can happen in any
3485 // user code which calls methods in java.lang.Compiler.
3486 // Hack : the hack is to pre-load and initialize this class, so that only
3487 // system domains are on the stack when the properties are read.
3488 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3489 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3490 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3491 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3492 // Once that is done, we should remove this hack.
3493 initialize_class(vmSymbols::java_lang_Compiler(), CHECK_0);
3494
3495 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3496 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3497 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3498 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3499 // This should also be taken out as soon as 4211383 gets fixed.
3500 reset_vm_info_property(CHECK_0);
3501
3502 quicken_jni_functions();
3503
3504 // Must be run after init_ft which initializes ft_enabled
3505 if (TRACE_INITIALIZE() != JNI_OK) {
3506 vm_exit_during_initialization("Failed to initialize tracing backend");
3507 }
3508
3509 // Set flag that basic initialization has completed. Used by exceptions and various
3510 // debug stuff, that does not work until all basic classes have been initialized.
3511 set_init_completed();
3512
3513 #ifndef USDT2
3514 HS_DTRACE_PROBE(hotspot, vm__init__end);
3515 #else /* USDT2 */
3516 HOTSPOT_VM_INIT_END();
3517 #endif /* USDT2 */
3518
3519 // record VM initialization completion time
3520 Management::record_vm_init_completed();
3521
3522 // Compute system loader. Note that this has to occur after set_init_completed, since
3523 // valid exceptions may be thrown in the process.
3524 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3525 // set_init_completed has just been called, causing exceptions not to be shortcut
3526 // anymore. We call vm_exit_during_initialization directly instead.
3527 SystemDictionary::compute_java_system_loader(THREAD);
3528 if (HAS_PENDING_EXCEPTION) {
3529 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3530 }
3531
3532 #ifndef SERIALGC
3533 // Support for ConcurrentMarkSweep. This should be cleaned up
3534 // and better encapsulated. The ugly nested if test would go away
3535 // once things are properly refactored. XXX YSR
3536 if (UseConcMarkSweepGC || UseG1GC) {
3537 if (UseConcMarkSweepGC) {
3538 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3539 } else {
3540 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3541 }
3542 if (HAS_PENDING_EXCEPTION) {
3543 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3544 }
3545 }
3546 #endif // SERIALGC
3547
3548 // Always call even when there are not JVMTI environments yet, since environments
3549 // may be attached late and JVMTI must track phases of VM execution
3550 JvmtiExport::enter_live_phase();
3551
3552 // Signal Dispatcher needs to be started before VMInit event is posted
3553 os::signal_init();
3554
3555 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3556 if (!DisableAttachMechanism) {
3557 if (StartAttachListener || AttachListener::init_at_startup()) {
3558 AttachListener::init();
3559 }
3560 }
3561
3562 // Launch -Xrun agents
3563 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3564 // back-end can launch with -Xdebug -Xrunjdwp.
3565 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3566 create_vm_init_libraries();
3567 }
3568
3569 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3570 JvmtiExport::post_vm_initialized();
3571
3572 if (!TRACE_START()) {
3573 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3574 }
3575
3576 if (CleanChunkPoolAsync) {
3577 Chunk::start_chunk_pool_cleaner_task();
3578 }
3579
3580 // initialize compiler(s)
3581 CompileBroker::compilation_init();
3582
3583 Management::initialize(THREAD);
3584 if (HAS_PENDING_EXCEPTION) {
3585 // management agent fails to start possibly due to
3586 // configuration problem and is responsible for printing
3587 // stack trace if appropriate. Simply exit VM.
3588 vm_exit(1);
3589 }
3590
3591 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3592 if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
3593 if (MemProfiling) MemProfiler::engage();
3594 StatSampler::engage();
3595 if (CheckJNICalls) JniPeriodicChecker::engage();
3596
3597 BiasedLocking::init();
3598
3599 if (JDK_Version::current().post_vm_init_hook_enabled()) {
3600 call_postVMInitHook(THREAD);
3601 // The Java side of PostVMInitHook.run must deal with all
3602 // exceptions and provide means of diagnosis.
3603 if (HAS_PENDING_EXCEPTION) {
3604 CLEAR_PENDING_EXCEPTION;
3605 }
3606 }
3607
3608 // Start up the WatcherThread if there are any periodic tasks
3609 // NOTE: All PeriodicTasks should be registered by now. If they
3610 // aren't, late joiners might appear to start slowly (we might
3611 // take a while to process their first tick).
3612 if (PeriodicTask::num_tasks() > 0) {
3613 WatcherThread::start();
3614 }
3615
3616 // Give os specific code one last chance to start
3617 os::init_3();
3618
3619 create_vm_timer.end();
3620 #ifdef ASSERT
3621 _vm_complete = true;
3622 #endif
3623 return JNI_OK;
3624 }
3625
3626 // type for the Agent_OnLoad and JVM_OnLoad entry points
3627 extern "C" {
3628 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3629 }
3630 // Find a command line agent library and return its entry point for
3631 // -agentlib: -agentpath: -Xrun
3632 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3633 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3634 OnLoadEntry_t on_load_entry = NULL;
3635 void *library = agent->os_lib(); // check if we have looked it up before
3636
3637 if (library == NULL) {
3638 char buffer[JVM_MAXPATHLEN];
3639 char ebuf[1024];
3640 const char *name = agent->name();
3641 const char *msg = "Could not find agent library ";
3642
3643 if (agent->is_absolute_path()) {
3644 library = os::dll_load(name, ebuf, sizeof ebuf);
3645 if (library == NULL) {
3646 const char *sub_msg = " in absolute path, with error: ";
3647 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3648 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3649 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3650 // If we can't find the agent, exit.
3651 vm_exit_during_initialization(buf, NULL);
3652 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3653 }
3654 } else {
3655 // Try to load the agent from the standard dll directory
3656 os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name);
3657 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3658 #ifdef KERNEL
3659 // Download instrument dll
3660 if (library == NULL && strcmp(name, "instrument") == 0) {
3661 char *props = Arguments::get_kernel_properties();
3662 char *home = Arguments::get_java_home();
3663 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false"
3664 " sun.jkernel.DownloadManager -download client_jvm";
3665 size_t length = strlen(props) + strlen(home) + strlen(fmt) + 1;
3666 char *cmd = NEW_C_HEAP_ARRAY(char, length, mtThread);
3667 jio_snprintf(cmd, length, fmt, home, props);
3668 int status = os::fork_and_exec(cmd);
3669 FreeHeap(props);
3670 if (status == -1) {
3671 warning(cmd);
3672 vm_exit_during_initialization("fork_and_exec failed: %s",
3673 strerror(errno));
3674 }
3675 FREE_C_HEAP_ARRAY(char, cmd, mtThread);
3676 // when this comes back the instrument.dll should be where it belongs.
3677 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3678 }
3679 #endif // KERNEL
3680 if (library == NULL) { // Try the local directory
3681 char ns[1] = {0};
3682 os::dll_build_name(buffer, sizeof(buffer), ns, name);
3683 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3684 if (library == NULL) {
3685 const char *sub_msg = " on the library path, with error: ";
3686 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3687 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3688 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3689 // If we can't find the agent, exit.
3690 vm_exit_during_initialization(buf, NULL);
3691 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3692 }
3693 }
3694 }
3695 agent->set_os_lib(library);
3696 }
3697
3698 // Find the OnLoad function.
3699 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
3700 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, os::dll_lookup(library, on_load_symbols[symbol_index]));
3701 if (on_load_entry != NULL) break;
3702 }
3703 return on_load_entry;
3704 }
3705
3706 // Find the JVM_OnLoad entry point
3707 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3708 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3709 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3710 }
3711
3712 // Find the Agent_OnLoad entry point
3713 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3714 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3715 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3716 }
3717
3718 // For backwards compatibility with -Xrun
3719 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3720 // treated like -agentpath:
3721 // Must be called before agent libraries are created
3722 void Threads::convert_vm_init_libraries_to_agents() {
3723 AgentLibrary* agent;
3724 AgentLibrary* next;
3725
3726 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3727 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3728 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3729
3730 // If there is an JVM_OnLoad function it will get called later,
3731 // otherwise see if there is an Agent_OnLoad
3732 if (on_load_entry == NULL) {
3733 on_load_entry = lookup_agent_on_load(agent);
3734 if (on_load_entry != NULL) {
3735 // switch it to the agent list -- so that Agent_OnLoad will be called,
3736 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3737 Arguments::convert_library_to_agent(agent);
3738 } else {
3739 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3740 }
3741 }
3742 }
3743 }
3744
3745 // Create agents for -agentlib: -agentpath: and converted -Xrun
3746 // Invokes Agent_OnLoad
3747 // Called very early -- before JavaThreads exist
3748 void Threads::create_vm_init_agents() {
3749 extern struct JavaVM_ main_vm;
3750 AgentLibrary* agent;
3751
3752 JvmtiExport::enter_onload_phase();
3753 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3754 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3755
3756 if (on_load_entry != NULL) {
3757 // Invoke the Agent_OnLoad function
3758 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3759 if (err != JNI_OK) {
3760 vm_exit_during_initialization("agent library failed to init", agent->name());
3761 }
3762 } else {
3763 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3764 }
3765 }
3766 JvmtiExport::enter_primordial_phase();
3767 }
3768
3769 extern "C" {
3770 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3771 }
3772
3773 void Threads::shutdown_vm_agents() {
3774 // Send any Agent_OnUnload notifications
3775 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3776 extern struct JavaVM_ main_vm;
3777 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3778
3779 // Find the Agent_OnUnload function.
3780 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
3781 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3782 os::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
3783
3784 // Invoke the Agent_OnUnload function
3785 if (unload_entry != NULL) {
3786 JavaThread* thread = JavaThread::current();
3787 ThreadToNativeFromVM ttn(thread);
3788 HandleMark hm(thread);
3789 (*unload_entry)(&main_vm);
3790 break;
3791 }
3792 }
3793 }
3794 }
3795
3796 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3797 // Invokes JVM_OnLoad
3798 void Threads::create_vm_init_libraries() {
3799 extern struct JavaVM_ main_vm;
3800 AgentLibrary* agent;
3801
3802 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3803 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3804
3805 if (on_load_entry != NULL) {
3806 // Invoke the JVM_OnLoad function
3807 JavaThread* thread = JavaThread::current();
3808 ThreadToNativeFromVM ttn(thread);
3809 HandleMark hm(thread);
3810 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3811 if (err != JNI_OK) {
3812 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3813 }
3814 } else {
3815 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3816 }
3817 }
3818 }
3819
3820 // Last thread running calls java.lang.Shutdown.shutdown()
3821 void JavaThread::invoke_shutdown_hooks() {
3822 HandleMark hm(this);
3823
3824 // We could get here with a pending exception, if so clear it now.
3825 if (this->has_pending_exception()) {
3826 this->clear_pending_exception();
3827 }
3828
3829 EXCEPTION_MARK;
3830 Klass* k =
3831 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3832 THREAD);
3833 if (k != NULL) {
3834 // SystemDictionary::resolve_or_null will return null if there was
3835 // an exception. If we cannot load the Shutdown class, just don't
3836 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3837 // and finalizers (if runFinalizersOnExit is set) won't be run.
3838 // Note that if a shutdown hook was registered or runFinalizersOnExit
3839 // was called, the Shutdown class would have already been loaded
3840 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3841 instanceKlassHandle shutdown_klass (THREAD, k);
3842 JavaValue result(T_VOID);
3843 JavaCalls::call_static(&result,
3844 shutdown_klass,
3845 vmSymbols::shutdown_method_name(),
3846 vmSymbols::void_method_signature(),
3847 THREAD);
3848 }
3849 CLEAR_PENDING_EXCEPTION;
3850 }
3851
3852 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3853 // the program falls off the end of main(). Another VM exit path is through
3854 // vm_exit() when the program calls System.exit() to return a value or when
3855 // there is a serious error in VM. The two shutdown paths are not exactly
3856 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3857 // and VM_Exit op at VM level.
3858 //
3859 // Shutdown sequence:
3860 // + Shutdown native memory tracking if it is on
3861 // + Wait until we are the last non-daemon thread to execute
3862 // <-- every thing is still working at this moment -->
3863 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3864 // shutdown hooks, run finalizers if finalization-on-exit
3865 // + Call before_exit(), prepare for VM exit
3866 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3867 // currently the only user of this mechanism is File.deleteOnExit())
3868 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3869 // post thread end and vm death events to JVMTI,
3870 // stop signal thread
3871 // + Call JavaThread::exit(), it will:
3872 // > release JNI handle blocks, remove stack guard pages
3873 // > remove this thread from Threads list
3874 // <-- no more Java code from this thread after this point -->
3875 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3876 // the compiler threads at safepoint
3877 // <-- do not use anything that could get blocked by Safepoint -->
3878 // + Disable tracing at JNI/JVM barriers
3879 // + Set _vm_exited flag for threads that are still running native code
3880 // + Delete this thread
3881 // + Call exit_globals()
3882 // > deletes tty
3883 // > deletes PerfMemory resources
3884 // + Return to caller
3885
3886 bool Threads::destroy_vm() {
3887 JavaThread* thread = JavaThread::current();
3888
3889 #ifdef ASSERT
3890 _vm_complete = false;
3891 #endif
3892 // Wait until we are the last non-daemon thread to execute
3893 { MutexLocker nu(Threads_lock);
3894 while (Threads::number_of_non_daemon_threads() > 1 )
3895 // This wait should make safepoint checks, wait without a timeout,
3896 // and wait as a suspend-equivalent condition.
3897 //
3898 // Note: If the FlatProfiler is running and this thread is waiting
3899 // for another non-daemon thread to finish, then the FlatProfiler
3900 // is waiting for the external suspend request on this thread to
3901 // complete. wait_for_ext_suspend_completion() will eventually
3902 // timeout, but that takes time. Making this wait a suspend-
3903 // equivalent condition solves that timeout problem.
3904 //
3905 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
3906 Mutex::_as_suspend_equivalent_flag);
3907 }
3908
3909 // Shutdown NMT before exit. Otherwise,
3910 // it will run into trouble when system destroys static variables.
3911 MemTracker::shutdown(MemTracker::NMT_normal);
3912
3913 // Hang forever on exit if we are reporting an error.
3914 if (ShowMessageBoxOnError && is_error_reported()) {
3915 os::infinite_sleep();
3916 }
3917 os::wait_for_keypress_at_exit();
3918
3919 if (JDK_Version::is_jdk12x_version()) {
3920 // We are the last thread running, so check if finalizers should be run.
3921 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
3922 HandleMark rm(thread);
3923 Universe::run_finalizers_on_exit();
3924 } else {
3925 // run Java level shutdown hooks
3926 thread->invoke_shutdown_hooks();
3927 }
3928
3929 before_exit(thread);
3930
3931 thread->exit(true);
3932
3933 // Stop VM thread.
3934 {
3935 // 4945125 The vm thread comes to a safepoint during exit.
3936 // GC vm_operations can get caught at the safepoint, and the
3937 // heap is unparseable if they are caught. Grab the Heap_lock
3938 // to prevent this. The GC vm_operations will not be able to
3939 // queue until after the vm thread is dead.
3940 // After this point, we'll never emerge out of the safepoint before
3941 // the VM exits, so concurrent GC threads do not need to be explicitly
3942 // stopped; they remain inactive until the process exits.
3943 // Note: some concurrent G1 threads may be running during a safepoint,
3944 // but these will not be accessing the heap, just some G1-specific side
3945 // data structures that are not accessed by any other threads but them
3946 // after this point in a terminal safepoint.
3947
3948 MutexLocker ml(Heap_lock);
3949
3950 VMThread::wait_for_vm_thread_exit();
3951 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3952 VMThread::destroy();
3953 }
3954
3955 // clean up ideal graph printers
3956 #if defined(COMPILER2) && !defined(PRODUCT)
3957 IdealGraphPrinter::clean_up();
3958 #endif
3959
3960 // Now, all Java threads are gone except daemon threads. Daemon threads
3961 // running Java code or in VM are stopped by the Safepoint. However,
3962 // daemon threads executing native code are still running. But they
3963 // will be stopped at native=>Java/VM barriers. Note that we can't
3964 // simply kill or suspend them, as it is inherently deadlock-prone.
3965
3966 #ifndef PRODUCT
3967 // disable function tracing at JNI/JVM barriers
3968 TraceJNICalls = false;
3969 TraceJVMCalls = false;
3970 TraceRuntimeCalls = false;
3971 #endif
3972
3973 VM_Exit::set_vm_exited();
3974
3975 notify_vm_shutdown();
3976
3977 delete thread;
3978
3979 // exit_globals() will delete tty
3980 exit_globals();
3981
3982 return true;
3983 }
3984
3985
3986 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3987 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3988 return is_supported_jni_version(version);
3989 }
3990
3991
3992 jboolean Threads::is_supported_jni_version(jint version) {
3993 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3994 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3995 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3996 return JNI_FALSE;
3997 }
3998
3999
4000 void Threads::add(JavaThread* p, bool force_daemon) {
4001 // The threads lock must be owned at this point
4002 assert_locked_or_safepoint(Threads_lock);
4003
4004 // See the comment for this method in thread.hpp for its purpose and
4005 // why it is called here.
4006 p->initialize_queues();
4007 p->set_next(_thread_list);
4008 _thread_list = p;
4009 _number_of_threads++;
4010 oop threadObj = p->threadObj();
4011 bool daemon = true;
4012 // Bootstrapping problem: threadObj can be null for initial
4013 // JavaThread (or for threads attached via JNI)
4014 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
4015 _number_of_non_daemon_threads++;
4016 daemon = false;
4017 }
4018
4019 p->set_safepoint_visible(true);
4020
4021 ThreadService::add_thread(p, daemon);
4022
4023 // Possible GC point.
4024 Events::log(p, "Thread added: " INTPTR_FORMAT, p);
4025 }
4026
4027 void Threads::remove(JavaThread* p) {
4028 // Extra scope needed for Thread_lock, so we can check
4029 // that we do not remove thread without safepoint code notice
4030 { MutexLocker ml(Threads_lock);
4031
4032 assert(includes(p), "p must be present");
4033
4034 JavaThread* current = _thread_list;
4035 JavaThread* prev = NULL;
4036
4037 while (current != p) {
4038 prev = current;
4039 current = current->next();
4040 }
4041
4042 if (prev) {
4043 prev->set_next(current->next());
4044 } else {
4045 _thread_list = p->next();
4046 }
4047 _number_of_threads--;
4048 oop threadObj = p->threadObj();
4049 bool daemon = true;
4050 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
4051 _number_of_non_daemon_threads--;
4052 daemon = false;
4053
4054 // Only one thread left, do a notify on the Threads_lock so a thread waiting
4055 // on destroy_vm will wake up.
4056 if (number_of_non_daemon_threads() == 1)
4057 Threads_lock->notify_all();
4058 }
4059 ThreadService::remove_thread(p, daemon);
4060
4061 // Make sure that safepoint code disregard this thread. This is needed since
4062 // the thread might mess around with locks after this point. This can cause it
4063 // to do callbacks into the safepoint code. However, the safepoint code is not aware
4064 // of this thread since it is removed from the queue.
4065 p->set_terminated_value();
4066
4067 // Now, this thread is not visible to safepoint
4068 p->set_safepoint_visible(false);
4069
4070 } // unlock Threads_lock
4071
4072 // Since Events::log uses a lock, we grab it outside the Threads_lock
4073 Events::log(p, "Thread exited: " INTPTR_FORMAT, p);
4074 }
4075
4076 // Threads_lock must be held when this is called (or must be called during a safepoint)
4077 bool Threads::includes(JavaThread* p) {
4078 assert(Threads_lock->is_locked(), "sanity check");
4079 ALL_JAVA_THREADS(q) {
4080 if (q == p ) {
4081 return true;
4082 }
4083 }
4084 return false;
4085 }
4086
4087 // Operations on the Threads list for GC. These are not explicitly locked,
4088 // but the garbage collector must provide a safe context for them to run.
4089 // In particular, these things should never be called when the Threads_lock
4090 // is held by some other thread. (Note: the Safepoint abstraction also
4091 // uses the Threads_lock to gurantee this property. It also makes sure that
4092 // all threads gets blocked when exiting or starting).
4093
4094 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
4095 ALL_JAVA_THREADS(p) {
4096 p->oops_do(f, cf);
4097 }
4098 VMThread::vm_thread()->oops_do(f, cf);
4099 }
4100
4101 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) {
4102 // Introduce a mechanism allowing parallel threads to claim threads as
4103 // root groups. Overhead should be small enough to use all the time,
4104 // even in sequential code.
4105 SharedHeap* sh = SharedHeap::heap();
4106 // Cannot yet substitute active_workers for n_par_threads
4107 // because of G1CollectedHeap::verify() use of
4108 // SharedHeap::process_strong_roots(). n_par_threads == 0 will
4109 // turn off parallelism in process_strong_roots while active_workers
4110 // is being used for parallelism elsewhere.
4111 bool is_par = sh->n_par_threads() > 0;
4112 assert(!is_par ||
4113 (SharedHeap::heap()->n_par_threads() ==
4114 SharedHeap::heap()->workers()->active_workers()), "Mismatch");
4115 int cp = SharedHeap::heap()->strong_roots_parity();
4116 ALL_JAVA_THREADS(p) {
4117 if (p->claim_oops_do(is_par, cp)) {
4118 p->oops_do(f, cf);
4119 }
4120 }
4121 VMThread* vmt = VMThread::vm_thread();
4122 if (vmt->claim_oops_do(is_par, cp)) {
4123 vmt->oops_do(f, cf);
4124 }
4125 }
4126
4127 #ifndef SERIALGC
4128 // Used by ParallelScavenge
4129 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
4130 ALL_JAVA_THREADS(p) {
4131 q->enqueue(new ThreadRootsTask(p));
4132 }
4133 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
4134 }
4135
4136 // Used by Parallel Old
4137 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
4138 ALL_JAVA_THREADS(p) {
4139 q->enqueue(new ThreadRootsMarkingTask(p));
4140 }
4141 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
4142 }
4143 #endif // SERIALGC
4144
4145 void Threads::nmethods_do(CodeBlobClosure* cf) {
4146 ALL_JAVA_THREADS(p) {
4147 p->nmethods_do(cf);
4148 }
4149 VMThread::vm_thread()->nmethods_do(cf);
4150 }
4151
4152 void Threads::metadata_do(void f(Metadata*)) {
4153 ALL_JAVA_THREADS(p) {
4154 p->metadata_do(f);
4155 }
4156 }
4157
4158 void Threads::gc_epilogue() {
4159 ALL_JAVA_THREADS(p) {
4160 p->gc_epilogue();
4161 }
4162 }
4163
4164 void Threads::gc_prologue() {
4165 ALL_JAVA_THREADS(p) {
4166 p->gc_prologue();
4167 }
4168 }
4169
4170 void Threads::deoptimized_wrt_marked_nmethods() {
4171 ALL_JAVA_THREADS(p) {
4172 p->deoptimized_wrt_marked_nmethods();
4173 }
4174 }
4175
4176
4177 // Get count Java threads that are waiting to enter the specified monitor.
4178 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
4179 address monitor, bool doLock) {
4180 assert(doLock || SafepointSynchronize::is_at_safepoint(),
4181 "must grab Threads_lock or be at safepoint");
4182 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
4183
4184 int i = 0;
4185 {
4186 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4187 ALL_JAVA_THREADS(p) {
4188 if (p->is_Compiler_thread()) continue;
4189
4190 address pending = (address)p->current_pending_monitor();
4191 if (pending == monitor) { // found a match
4192 if (i < count) result->append(p); // save the first count matches
4193 i++;
4194 }
4195 }
4196 }
4197 return result;
4198 }
4199
4200
4201 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
4202 assert(doLock ||
4203 Threads_lock->owned_by_self() ||
4204 SafepointSynchronize::is_at_safepoint(),
4205 "must grab Threads_lock or be at safepoint");
4206
4207 // NULL owner means not locked so we can skip the search
4208 if (owner == NULL) return NULL;
4209
4210 {
4211 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4212 ALL_JAVA_THREADS(p) {
4213 // first, see if owner is the address of a Java thread
4214 if (owner == (address)p) return p;
4215 }
4216 }
4217 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
4218 if (UseHeavyMonitors) return NULL;
4219
4220 //
4221 // If we didn't find a matching Java thread and we didn't force use of
4222 // heavyweight monitors, then the owner is the stack address of the
4223 // Lock Word in the owning Java thread's stack.
4224 //
4225 JavaThread* the_owner = NULL;
4226 {
4227 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4228 ALL_JAVA_THREADS(q) {
4229 if (q->is_lock_owned(owner)) {
4230 the_owner = q;
4231 break;
4232 }
4233 }
4234 }
4235 assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
4236 return the_owner;
4237 }
4238
4239 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
4240 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
4241 char buf[32];
4242 st->print_cr(os::local_time_string(buf, sizeof(buf)));
4243
4244 st->print_cr("Full thread dump %s (%s %s):",
4245 Abstract_VM_Version::vm_name(),
4246 Abstract_VM_Version::vm_release(),
4247 Abstract_VM_Version::vm_info_string()
4248 );
4249 st->cr();
4250
4251 #ifndef SERIALGC
4252 // Dump concurrent locks
4253 ConcurrentLocksDump concurrent_locks;
4254 if (print_concurrent_locks) {
4255 concurrent_locks.dump_at_safepoint();
4256 }
4257 #endif // SERIALGC
4258
4259 ALL_JAVA_THREADS(p) {
4260 ResourceMark rm;
4261 p->print_on(st);
4262 if (print_stacks) {
4263 if (internal_format) {
4264 p->trace_stack();
4265 } else {
4266 p->print_stack_on(st);
4267 }
4268 }
4269 st->cr();
4270 #ifndef SERIALGC
4271 if (print_concurrent_locks) {
4272 concurrent_locks.print_locks_on(p, st);
4273 }
4274 #endif // SERIALGC
4275 }
4276
4277 VMThread::vm_thread()->print_on(st);
4278 st->cr();
4279 Universe::heap()->print_gc_threads_on(st);
4280 WatcherThread* wt = WatcherThread::watcher_thread();
4281 if (wt != NULL) {
4282 wt->print_on(st);
4283 st->cr();
4284 }
4285 CompileBroker::print_compiler_threads_on(st);
4286 st->flush();
4287 }
4288
4289 // Threads::print_on_error() is called by fatal error handler. It's possible
4290 // that VM is not at safepoint and/or current thread is inside signal handler.
4291 // Don't print stack trace, as the stack may not be walkable. Don't allocate
4292 // memory (even in resource area), it might deadlock the error handler.
4293 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
4294 bool found_current = false;
4295 st->print_cr("Java Threads: ( => current thread )");
4296 ALL_JAVA_THREADS(thread) {
4297 bool is_current = (current == thread);
4298 found_current = found_current || is_current;
4299
4300 st->print("%s", is_current ? "=>" : " ");
4301
4302 st->print(PTR_FORMAT, thread);
4303 st->print(" ");
4304 thread->print_on_error(st, buf, buflen);
4305 st->cr();
4306 }
4307 st->cr();
4308
4309 st->print_cr("Other Threads:");
4310 if (VMThread::vm_thread()) {
4311 bool is_current = (current == VMThread::vm_thread());
4312 found_current = found_current || is_current;
4313 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
4314
4315 st->print(PTR_FORMAT, VMThread::vm_thread());
4316 st->print(" ");
4317 VMThread::vm_thread()->print_on_error(st, buf, buflen);
4318 st->cr();
4319 }
4320 WatcherThread* wt = WatcherThread::watcher_thread();
4321 if (wt != NULL) {
4322 bool is_current = (current == wt);
4323 found_current = found_current || is_current;
4324 st->print("%s", is_current ? "=>" : " ");
4325
4326 st->print(PTR_FORMAT, wt);
4327 st->print(" ");
4328 wt->print_on_error(st, buf, buflen);
4329 st->cr();
4330 }
4331 if (!found_current) {
4332 st->cr();
4333 st->print("=>" PTR_FORMAT " (exited) ", current);
4334 current->print_on_error(st, buf, buflen);
4335 st->cr();
4336 }
4337 }
4338
4339 // Internal SpinLock and Mutex
4340 // Based on ParkEvent
4341
4342 // Ad-hoc mutual exclusion primitives: SpinLock and Mux
4343 //
4344 // We employ SpinLocks _only for low-contention, fixed-length
4345 // short-duration critical sections where we're concerned
4346 // about native mutex_t or HotSpot Mutex:: latency.
4347 // The mux construct provides a spin-then-block mutual exclusion
4348 // mechanism.
4349 //
4350 // Testing has shown that contention on the ListLock guarding gFreeList
4351 // is common. If we implement ListLock as a simple SpinLock it's common
4352 // for the JVM to devolve to yielding with little progress. This is true
4353 // despite the fact that the critical sections protected by ListLock are
4354 // extremely short.
4355 //
4356 // TODO-FIXME: ListLock should be of type SpinLock.
4357 // We should make this a 1st-class type, integrated into the lock
4358 // hierarchy as leaf-locks. Critically, the SpinLock structure
4359 // should have sufficient padding to avoid false-sharing and excessive
4360 // cache-coherency traffic.
4361
4362
4363 typedef volatile int SpinLockT ;
4364
4365 void Thread::SpinAcquire (volatile int * adr, const char * LockName) {
4366 if (Atomic::cmpxchg (1, adr, 0) == 0) {
4367 return ; // normal fast-path return
4368 }
4369
4370 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
4371 TEVENT (SpinAcquire - ctx) ;
4372 int ctr = 0 ;
4373 int Yields = 0 ;
4374 for (;;) {
4375 while (*adr != 0) {
4376 ++ctr ;
4377 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
4378 if (Yields > 5) {
4379 // Consider using a simple NakedSleep() instead.
4380 // Then SpinAcquire could be called by non-JVM threads
4381 Thread::current()->_ParkEvent->park(1) ;
4382 } else {
4383 os::NakedYield() ;
4384 ++Yields ;
4385 }
4386 } else {
4387 SpinPause() ;
4388 }
4389 }
4390 if (Atomic::cmpxchg (1, adr, 0) == 0) return ;
4391 }
4392 }
4393
4394 void Thread::SpinRelease (volatile int * adr) {
4395 assert (*adr != 0, "invariant") ;
4396 OrderAccess::fence() ; // guarantee at least release consistency.
4397 // Roach-motel semantics.
4398 // It's safe if subsequent LDs and STs float "up" into the critical section,
4399 // but prior LDs and STs within the critical section can't be allowed
4400 // to reorder or float past the ST that releases the lock.
4401 *adr = 0 ;
4402 }
4403
4404 // muxAcquire and muxRelease:
4405 //
4406 // * muxAcquire and muxRelease support a single-word lock-word construct.
4407 // The LSB of the word is set IFF the lock is held.
4408 // The remainder of the word points to the head of a singly-linked list
4409 // of threads blocked on the lock.
4410 //
4411 // * The current implementation of muxAcquire-muxRelease uses its own
4412 // dedicated Thread._MuxEvent instance. If we're interested in
4413 // minimizing the peak number of extant ParkEvent instances then
4414 // we could eliminate _MuxEvent and "borrow" _ParkEvent as long
4415 // as certain invariants were satisfied. Specifically, care would need
4416 // to be taken with regards to consuming unpark() "permits".
4417 // A safe rule of thumb is that a thread would never call muxAcquire()
4418 // if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently
4419 // park(). Otherwise the _ParkEvent park() operation in muxAcquire() could
4420 // consume an unpark() permit intended for monitorenter, for instance.
4421 // One way around this would be to widen the restricted-range semaphore
4422 // implemented in park(). Another alternative would be to provide
4423 // multiple instances of the PlatformEvent() for each thread. One
4424 // instance would be dedicated to muxAcquire-muxRelease, for instance.
4425 //
4426 // * Usage:
4427 // -- Only as leaf locks
4428 // -- for short-term locking only as muxAcquire does not perform
4429 // thread state transitions.
4430 //
4431 // Alternatives:
4432 // * We could implement muxAcquire and muxRelease with MCS or CLH locks
4433 // but with parking or spin-then-park instead of pure spinning.
4434 // * Use Taura-Oyama-Yonenzawa locks.
4435 // * It's possible to construct a 1-0 lock if we encode the lockword as
4436 // (List,LockByte). Acquire will CAS the full lockword while Release
4437 // will STB 0 into the LockByte. The 1-0 scheme admits stranding, so
4438 // acquiring threads use timers (ParkTimed) to detect and recover from
4439 // the stranding window. Thread/Node structures must be aligned on 256-byte
4440 // boundaries by using placement-new.
4441 // * Augment MCS with advisory back-link fields maintained with CAS().
4442 // Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner.
4443 // The validity of the backlinks must be ratified before we trust the value.
4444 // If the backlinks are invalid the exiting thread must back-track through the
4445 // the forward links, which are always trustworthy.
4446 // * Add a successor indication. The LockWord is currently encoded as
4447 // (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable
4448 // to provide the usual futile-wakeup optimization.
4449 // See RTStt for details.
4450 // * Consider schedctl.sc_nopreempt to cover the critical section.
4451 //
4452
4453
4454 typedef volatile intptr_t MutexT ; // Mux Lock-word
4455 enum MuxBits { LOCKBIT = 1 } ;
4456
4457 void Thread::muxAcquire (volatile intptr_t * Lock, const char * LockName) {
4458 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4459 if (w == 0) return ;
4460 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4461 return ;
4462 }
4463
4464 TEVENT (muxAcquire - Contention) ;
4465 ParkEvent * const Self = Thread::current()->_MuxEvent ;
4466 assert ((intptr_t(Self) & LOCKBIT) == 0, "invariant") ;
4467 for (;;) {
4468 int its = (os::is_MP() ? 100 : 0) + 1 ;
4469
4470 // Optional spin phase: spin-then-park strategy
4471 while (--its >= 0) {
4472 w = *Lock ;
4473 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4474 return ;
4475 }
4476 }
4477
4478 Self->reset() ;
4479 Self->OnList = intptr_t(Lock) ;
4480 // The following fence() isn't _strictly necessary as the subsequent
4481 // CAS() both serializes execution and ratifies the fetched *Lock value.
4482 OrderAccess::fence();
4483 for (;;) {
4484 w = *Lock ;
4485 if ((w & LOCKBIT) == 0) {
4486 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4487 Self->OnList = 0 ; // hygiene - allows stronger asserts
4488 return ;
4489 }
4490 continue ; // Interference -- *Lock changed -- Just retry
4491 }
4492 assert (w & LOCKBIT, "invariant") ;
4493 Self->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4494 if (Atomic::cmpxchg_ptr (intptr_t(Self)|LOCKBIT, Lock, w) == w) break ;
4495 }
4496
4497 while (Self->OnList != 0) {
4498 Self->park() ;
4499 }
4500 }
4501 }
4502
4503 void Thread::muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) {
4504 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4505 if (w == 0) return ;
4506 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4507 return ;
4508 }
4509
4510 TEVENT (muxAcquire - Contention) ;
4511 ParkEvent * ReleaseAfter = NULL ;
4512 if (ev == NULL) {
4513 ev = ReleaseAfter = ParkEvent::Allocate (NULL) ;
4514 }
4515 assert ((intptr_t(ev) & LOCKBIT) == 0, "invariant") ;
4516 for (;;) {
4517 guarantee (ev->OnList == 0, "invariant") ;
4518 int its = (os::is_MP() ? 100 : 0) + 1 ;
4519
4520 // Optional spin phase: spin-then-park strategy
4521 while (--its >= 0) {
4522 w = *Lock ;
4523 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4524 if (ReleaseAfter != NULL) {
4525 ParkEvent::Release (ReleaseAfter) ;
4526 }
4527 return ;
4528 }
4529 }
4530
4531 ev->reset() ;
4532 ev->OnList = intptr_t(Lock) ;
4533 // The following fence() isn't _strictly necessary as the subsequent
4534 // CAS() both serializes execution and ratifies the fetched *Lock value.
4535 OrderAccess::fence();
4536 for (;;) {
4537 w = *Lock ;
4538 if ((w & LOCKBIT) == 0) {
4539 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4540 ev->OnList = 0 ;
4541 // We call ::Release while holding the outer lock, thus
4542 // artificially lengthening the critical section.
4543 // Consider deferring the ::Release() until the subsequent unlock(),
4544 // after we've dropped the outer lock.
4545 if (ReleaseAfter != NULL) {
4546 ParkEvent::Release (ReleaseAfter) ;
4547 }
4548 return ;
4549 }
4550 continue ; // Interference -- *Lock changed -- Just retry
4551 }
4552 assert (w & LOCKBIT, "invariant") ;
4553 ev->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4554 if (Atomic::cmpxchg_ptr (intptr_t(ev)|LOCKBIT, Lock, w) == w) break ;
4555 }
4556
4557 while (ev->OnList != 0) {
4558 ev->park() ;
4559 }
4560 }
4561 }
4562
4563 // Release() must extract a successor from the list and then wake that thread.
4564 // It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme
4565 // similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based
4566 // Release() would :
4567 // (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list.
4568 // (B) Extract a successor from the private list "in-hand"
4569 // (C) attempt to CAS() the residual back into *Lock over null.
4570 // If there were any newly arrived threads and the CAS() would fail.
4571 // In that case Release() would detach the RATs, re-merge the list in-hand
4572 // with the RATs and repeat as needed. Alternately, Release() might
4573 // detach and extract a successor, but then pass the residual list to the wakee.
4574 // The wakee would be responsible for reattaching and remerging before it
4575 // competed for the lock.
4576 //
4577 // Both "pop" and DMR are immune from ABA corruption -- there can be
4578 // multiple concurrent pushers, but only one popper or detacher.
4579 // This implementation pops from the head of the list. This is unfair,
4580 // but tends to provide excellent throughput as hot threads remain hot.
4581 // (We wake recently run threads first).
4582
4583 void Thread::muxRelease (volatile intptr_t * Lock) {
4584 for (;;) {
4585 const intptr_t w = Atomic::cmpxchg_ptr (0, Lock, LOCKBIT) ;
4586 assert (w & LOCKBIT, "invariant") ;
4587 if (w == LOCKBIT) return ;
4588 ParkEvent * List = (ParkEvent *) (w & ~LOCKBIT) ;
4589 assert (List != NULL, "invariant") ;
4590 assert (List->OnList == intptr_t(Lock), "invariant") ;
4591 ParkEvent * nxt = List->ListNext ;
4592
4593 // The following CAS() releases the lock and pops the head element.
4594 if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) {
4595 continue ;
4596 }
4597 List->OnList = 0 ;
4598 OrderAccess::fence() ;
4599 List->unpark () ;
4600 return ;
4601 }
4602 }
4603
4604
4605 void Threads::verify() {
4606 ALL_JAVA_THREADS(p) {
4607 p->verify();
4608 }
4609 VMThread* thread = VMThread::vm_thread();
4610 if (thread != NULL) thread->verify();
4611 }