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 : AllocateHeap(aligned_size, flags, CURRENT_PC,
181 AllocFailStrategy::RETURN_NULL);
182 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment);
183 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
184 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
185 "JavaThread alignment code overflowed allocated storage");
186 if (TraceBiasedLocking) {
187 if (aligned_addr != real_malloc_addr)
188 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
189 real_malloc_addr, aligned_addr);
190 }
191 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
192 return aligned_addr;
193 } else {
194 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
195 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
196 }
197 }
198
199 void Thread::operator delete(void* p) {
200 if (UseBiasedLocking) {
201 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
202 FreeHeap(real_malloc_addr, mtThread);
203 } else {
204 FreeHeap(p, mtThread);
205 }
206 }
207
208
209 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
210 // JavaThread
211
212
213 Thread::Thread() {
214 // stack and get_thread
215 set_stack_base(NULL);
216 set_stack_size(0);
217 set_self_raw_id(0);
218 set_lgrp_id(-1);
219
220 // allocated data structures
221 set_osthread(NULL);
222 set_resource_area(new (mtThread)ResourceArea());
223 set_handle_area(new (mtThread) HandleArea(NULL));
224 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(300, true));
225 set_active_handles(NULL);
226 set_free_handle_block(NULL);
227 set_last_handle_mark(NULL);
228
229 // This initial value ==> never claimed.
230 _oops_do_parity = 0;
231
232 // the handle mark links itself to last_handle_mark
233 new HandleMark(this);
234
235 // plain initialization
236 debug_only(_owned_locks = NULL;)
237 debug_only(_allow_allocation_count = 0;)
238 NOT_PRODUCT(_allow_safepoint_count = 0;)
239 NOT_PRODUCT(_skip_gcalot = false;)
240 CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;)
241 _jvmti_env_iteration_count = 0;
242 set_allocated_bytes(0);
243 set_trace_buffer(NULL);
244 _vm_operation_started_count = 0;
245 _vm_operation_completed_count = 0;
246 _current_pending_monitor = NULL;
247 _current_pending_monitor_is_from_java = true;
248 _current_waiting_monitor = NULL;
249 _num_nested_signal = 0;
250 omFreeList = NULL ;
251 omFreeCount = 0 ;
252 omFreeProvision = 32 ;
253 omInUseList = NULL ;
254 omInUseCount = 0 ;
255
256 #ifdef ASSERT
257 _visited_for_critical_count = false;
258 #endif
259
260 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
261 _suspend_flags = 0;
262
263 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
264 _hashStateX = os::random() ;
265 _hashStateY = 842502087 ;
266 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
267 _hashStateW = 273326509 ;
268
269 _OnTrap = 0 ;
270 _schedctl = NULL ;
271 _Stalled = 0 ;
272 _TypeTag = 0x2BAD ;
273
274 // Many of the following fields are effectively final - immutable
275 // Note that nascent threads can't use the Native Monitor-Mutex
276 // construct until the _MutexEvent is initialized ...
277 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
278 // we might instead use a stack of ParkEvents that we could provision on-demand.
279 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
280 // and ::Release()
281 _ParkEvent = ParkEvent::Allocate (this) ;
282 _SleepEvent = ParkEvent::Allocate (this) ;
283 _MutexEvent = ParkEvent::Allocate (this) ;
284 _MuxEvent = ParkEvent::Allocate (this) ;
285
286 #ifdef CHECK_UNHANDLED_OOPS
287 if (CheckUnhandledOops) {
288 _unhandled_oops = new UnhandledOops(this);
289 }
290 #endif // CHECK_UNHANDLED_OOPS
291 #ifdef ASSERT
292 if (UseBiasedLocking) {
293 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
294 assert(this == _real_malloc_address ||
295 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
296 "bug in forced alignment of thread objects");
297 }
298 #endif /* ASSERT */
299 }
300
301 void Thread::initialize_thread_local_storage() {
302 // Note: Make sure this method only calls
303 // non-blocking operations. Otherwise, it might not work
304 // with the thread-startup/safepoint interaction.
305
306 // During Java thread startup, safepoint code should allow this
307 // method to complete because it may need to allocate memory to
308 // store information for the new thread.
309
310 // initialize structure dependent on thread local storage
311 ThreadLocalStorage::set_thread(this);
312 }
313
314 void Thread::record_stack_base_and_size() {
315 set_stack_base(os::current_stack_base());
316 set_stack_size(os::current_stack_size());
317 // CR 7190089: on Solaris, primordial thread's stack is adjusted
318 // in initialize_thread(). Without the adjustment, stack size is
319 // incorrect if stack is set to unlimited (ulimit -s unlimited).
320 // So far, only Solaris has real implementation of initialize_thread().
321 //
322 // set up any platform-specific state.
323 os::initialize_thread(this);
324
325 #if INCLUDE_NMT
326 // record thread's native stack, stack grows downward
327 address stack_low_addr = stack_base() - stack_size();
328 MemTracker::record_thread_stack(stack_low_addr, stack_size(), this,
329 CURRENT_PC);
330 #endif // INCLUDE_NMT
331 }
332
333
334 Thread::~Thread() {
335 // Reclaim the objectmonitors from the omFreeList of the moribund thread.
336 ObjectSynchronizer::omFlush (this) ;
337
338 // stack_base can be NULL if the thread is never started or exited before
339 // record_stack_base_and_size called. Although, we would like to ensure
340 // that all started threads do call record_stack_base_and_size(), there is
341 // not proper way to enforce that.
342 #if INCLUDE_NMT
343 if (_stack_base != NULL) {
344 address low_stack_addr = stack_base() - stack_size();
345 MemTracker::release_thread_stack(low_stack_addr, stack_size(), this);
346 #ifdef ASSERT
347 set_stack_base(NULL);
348 #endif
349 }
350 #endif // INCLUDE_NMT
351
352 // deallocate data structures
353 delete resource_area();
354 // since the handle marks are using the handle area, we have to deallocated the root
355 // handle mark before deallocating the thread's handle area,
356 assert(last_handle_mark() != NULL, "check we have an element");
357 delete last_handle_mark();
358 assert(last_handle_mark() == NULL, "check we have reached the end");
359
360 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
361 // We NULL out the fields for good hygiene.
362 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
363 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
364 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
365 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
366
367 delete handle_area();
368 delete metadata_handles();
369
370 // osthread() can be NULL, if creation of thread failed.
371 if (osthread() != NULL) os::free_thread(osthread());
372
373 delete _SR_lock;
374
375 // clear thread local storage if the Thread is deleting itself
376 if (this == Thread::current()) {
377 ThreadLocalStorage::set_thread(NULL);
378 } else {
379 // In the case where we're not the current thread, invalidate all the
380 // caches in case some code tries to get the current thread or the
381 // thread that was destroyed, and gets stale information.
382 ThreadLocalStorage::invalidate_all();
383 }
384 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
385 }
386
387 // NOTE: dummy function for assertion purpose.
388 void Thread::run() {
389 ShouldNotReachHere();
390 }
391
392 #ifdef ASSERT
393 // Private method to check for dangling thread pointer
394 void check_for_dangling_thread_pointer(Thread *thread) {
395 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
396 "possibility of dangling Thread pointer");
397 }
398 #endif
399
400
401 #ifndef PRODUCT
402 // Tracing method for basic thread operations
403 void Thread::trace(const char* msg, const Thread* const thread) {
404 if (!TraceThreadEvents) return;
405 ResourceMark rm;
406 ThreadCritical tc;
407 const char *name = "non-Java thread";
408 int prio = -1;
409 if (thread->is_Java_thread()
410 && !thread->is_Compiler_thread()) {
411 // The Threads_lock must be held to get information about
412 // this thread but may not be in some situations when
413 // tracing thread events.
414 bool release_Threads_lock = false;
415 if (!Threads_lock->owned_by_self()) {
416 Threads_lock->lock();
417 release_Threads_lock = true;
418 }
419 JavaThread* jt = (JavaThread *)thread;
420 name = (char *)jt->get_thread_name();
421 oop thread_oop = jt->threadObj();
422 if (thread_oop != NULL) {
423 prio = java_lang_Thread::priority(thread_oop);
424 }
425 if (release_Threads_lock) {
426 Threads_lock->unlock();
427 }
428 }
429 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
430 }
431 #endif
432
433
434 ThreadPriority Thread::get_priority(const Thread* const thread) {
435 trace("get priority", thread);
436 ThreadPriority priority;
437 // Can return an error!
438 (void)os::get_priority(thread, priority);
439 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
440 return priority;
441 }
442
443 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
444 trace("set priority", thread);
445 debug_only(check_for_dangling_thread_pointer(thread);)
446 // Can return an error!
447 (void)os::set_priority(thread, priority);
448 }
449
450
451 void Thread::start(Thread* thread) {
452 trace("start", thread);
453 // Start is different from resume in that its safety is guaranteed by context or
454 // being called from a Java method synchronized on the Thread object.
455 if (!DisableStartThread) {
456 if (thread->is_Java_thread()) {
457 // Initialize the thread state to RUNNABLE before starting this thread.
458 // Can not set it after the thread started because we do not know the
459 // exact thread state at that time. It could be in MONITOR_WAIT or
460 // in SLEEPING or some other state.
461 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
462 java_lang_Thread::RUNNABLE);
463 }
464 os::start_thread(thread);
465 }
466 }
467
468 // Enqueue a VM_Operation to do the job for us - sometime later
469 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
470 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
471 VMThread::execute(vm_stop);
472 }
473
474
475 //
476 // Check if an external suspend request has completed (or has been
477 // cancelled). Returns true if the thread is externally suspended and
478 // false otherwise.
479 //
480 // The bits parameter returns information about the code path through
481 // the routine. Useful for debugging:
482 //
483 // set in is_ext_suspend_completed():
484 // 0x00000001 - routine was entered
485 // 0x00000010 - routine return false at end
486 // 0x00000100 - thread exited (return false)
487 // 0x00000200 - suspend request cancelled (return false)
488 // 0x00000400 - thread suspended (return true)
489 // 0x00001000 - thread is in a suspend equivalent state (return true)
490 // 0x00002000 - thread is native and walkable (return true)
491 // 0x00004000 - thread is native_trans and walkable (needed retry)
492 //
493 // set in wait_for_ext_suspend_completion():
494 // 0x00010000 - routine was entered
495 // 0x00020000 - suspend request cancelled before loop (return false)
496 // 0x00040000 - thread suspended before loop (return true)
497 // 0x00080000 - suspend request cancelled in loop (return false)
498 // 0x00100000 - thread suspended in loop (return true)
499 // 0x00200000 - suspend not completed during retry loop (return false)
500 //
501
502 // Helper class for tracing suspend wait debug bits.
503 //
504 // 0x00000100 indicates that the target thread exited before it could
505 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
506 // 0x00080000 each indicate a cancelled suspend request so they don't
507 // count as wait failures either.
508 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
509
510 class TraceSuspendDebugBits : public StackObj {
511 private:
512 JavaThread * jt;
513 bool is_wait;
514 bool called_by_wait; // meaningful when !is_wait
515 uint32_t * bits;
516
517 public:
518 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
519 uint32_t *_bits) {
520 jt = _jt;
521 is_wait = _is_wait;
522 called_by_wait = _called_by_wait;
523 bits = _bits;
524 }
525
526 ~TraceSuspendDebugBits() {
527 if (!is_wait) {
528 #if 1
529 // By default, don't trace bits for is_ext_suspend_completed() calls.
530 // That trace is very chatty.
531 return;
532 #else
533 if (!called_by_wait) {
534 // If tracing for is_ext_suspend_completed() is enabled, then only
535 // trace calls to it from wait_for_ext_suspend_completion()
536 return;
537 }
538 #endif
539 }
540
541 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
542 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
543 MutexLocker ml(Threads_lock); // needed for get_thread_name()
544 ResourceMark rm;
545
546 tty->print_cr(
547 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
548 jt->get_thread_name(), *bits);
549
550 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
551 }
552 }
553 }
554 };
555 #undef DEBUG_FALSE_BITS
556
557
558 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
559 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
560
561 bool did_trans_retry = false; // only do thread_in_native_trans retry once
562 bool do_trans_retry; // flag to force the retry
563
564 *bits |= 0x00000001;
565
566 do {
567 do_trans_retry = false;
568
569 if (is_exiting()) {
570 // Thread is in the process of exiting. This is always checked
571 // first to reduce the risk of dereferencing a freed JavaThread.
572 *bits |= 0x00000100;
573 return false;
574 }
575
576 if (!is_external_suspend()) {
577 // Suspend request is cancelled. This is always checked before
578 // is_ext_suspended() to reduce the risk of a rogue resume
579 // confusing the thread that made the suspend request.
580 *bits |= 0x00000200;
581 return false;
582 }
583
584 if (is_ext_suspended()) {
585 // thread is suspended
586 *bits |= 0x00000400;
587 return true;
588 }
589
590 // Now that we no longer do hard suspends of threads running
591 // native code, the target thread can be changing thread state
592 // while we are in this routine:
593 //
594 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
595 //
596 // We save a copy of the thread state as observed at this moment
597 // and make our decision about suspend completeness based on the
598 // copy. This closes the race where the thread state is seen as
599 // _thread_in_native_trans in the if-thread_blocked check, but is
600 // seen as _thread_blocked in if-thread_in_native_trans check.
601 JavaThreadState save_state = thread_state();
602
603 if (save_state == _thread_blocked && is_suspend_equivalent()) {
604 // If the thread's state is _thread_blocked and this blocking
605 // condition is known to be equivalent to a suspend, then we can
606 // consider the thread to be externally suspended. This means that
607 // the code that sets _thread_blocked has been modified to do
608 // self-suspension if the blocking condition releases. We also
609 // used to check for CONDVAR_WAIT here, but that is now covered by
610 // the _thread_blocked with self-suspension check.
611 //
612 // Return true since we wouldn't be here unless there was still an
613 // external suspend request.
614 *bits |= 0x00001000;
615 return true;
616 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
617 // Threads running native code will self-suspend on native==>VM/Java
618 // transitions. If its stack is walkable (should always be the case
619 // unless this function is called before the actual java_suspend()
620 // call), then the wait is done.
621 *bits |= 0x00002000;
622 return true;
623 } else if (!called_by_wait && !did_trans_retry &&
624 save_state == _thread_in_native_trans &&
625 frame_anchor()->walkable()) {
626 // The thread is transitioning from thread_in_native to another
627 // thread state. check_safepoint_and_suspend_for_native_trans()
628 // will force the thread to self-suspend. If it hasn't gotten
629 // there yet we may have caught the thread in-between the native
630 // code check above and the self-suspend. Lucky us. If we were
631 // called by wait_for_ext_suspend_completion(), then it
632 // will be doing the retries so we don't have to.
633 //
634 // Since we use the saved thread state in the if-statement above,
635 // there is a chance that the thread has already transitioned to
636 // _thread_blocked by the time we get here. In that case, we will
637 // make a single unnecessary pass through the logic below. This
638 // doesn't hurt anything since we still do the trans retry.
639
640 *bits |= 0x00004000;
641
642 // Once the thread leaves thread_in_native_trans for another
643 // thread state, we break out of this retry loop. We shouldn't
644 // need this flag to prevent us from getting back here, but
645 // sometimes paranoia is good.
646 did_trans_retry = true;
647
648 // We wait for the thread to transition to a more usable state.
649 for (int i = 1; i <= SuspendRetryCount; i++) {
650 // We used to do an "os::yield_all(i)" call here with the intention
651 // that yielding would increase on each retry. However, the parameter
652 // is ignored on Linux which means the yield didn't scale up. Waiting
653 // on the SR_lock below provides a much more predictable scale up for
654 // the delay. It also provides a simple/direct point to check for any
655 // safepoint requests from the VMThread
656
657 // temporarily drops SR_lock while doing wait with safepoint check
658 // (if we're a JavaThread - the WatcherThread can also call this)
659 // and increase delay with each retry
660 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
661
662 // check the actual thread state instead of what we saved above
663 if (thread_state() != _thread_in_native_trans) {
664 // the thread has transitioned to another thread state so
665 // try all the checks (except this one) one more time.
666 do_trans_retry = true;
667 break;
668 }
669 } // end retry loop
670
671
672 }
673 } while (do_trans_retry);
674
675 *bits |= 0x00000010;
676 return false;
677 }
678
679 //
680 // Wait for an external suspend request to complete (or be cancelled).
681 // Returns true if the thread is externally suspended and false otherwise.
682 //
683 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
684 uint32_t *bits) {
685 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
686 false /* !called_by_wait */, bits);
687
688 // local flag copies to minimize SR_lock hold time
689 bool is_suspended;
690 bool pending;
691 uint32_t reset_bits;
692
693 // set a marker so is_ext_suspend_completed() knows we are the caller
694 *bits |= 0x00010000;
695
696 // We use reset_bits to reinitialize the bits value at the top of
697 // each retry loop. This allows the caller to make use of any
698 // unused bits for their own marking purposes.
699 reset_bits = *bits;
700
701 {
702 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
703 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
704 delay, bits);
705 pending = is_external_suspend();
706 }
707 // must release SR_lock to allow suspension to complete
708
709 if (!pending) {
710 // A cancelled suspend request is the only false return from
711 // is_ext_suspend_completed() that keeps us from entering the
712 // retry loop.
713 *bits |= 0x00020000;
714 return false;
715 }
716
717 if (is_suspended) {
718 *bits |= 0x00040000;
719 return true;
720 }
721
722 for (int i = 1; i <= retries; i++) {
723 *bits = reset_bits; // reinit to only track last retry
724
725 // We used to do an "os::yield_all(i)" call here with the intention
726 // that yielding would increase on each retry. However, the parameter
727 // is ignored on Linux which means the yield didn't scale up. Waiting
728 // on the SR_lock below provides a much more predictable scale up for
729 // the delay. It also provides a simple/direct point to check for any
730 // safepoint requests from the VMThread
731
732 {
733 MutexLocker ml(SR_lock());
734 // wait with safepoint check (if we're a JavaThread - the WatcherThread
735 // can also call this) and increase delay with each retry
736 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
737
738 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
739 delay, bits);
740
741 // It is possible for the external suspend request to be cancelled
742 // (by a resume) before the actual suspend operation is completed.
743 // Refresh our local copy to see if we still need to wait.
744 pending = is_external_suspend();
745 }
746
747 if (!pending) {
748 // A cancelled suspend request is the only false return from
749 // is_ext_suspend_completed() that keeps us from staying in the
750 // retry loop.
751 *bits |= 0x00080000;
752 return false;
753 }
754
755 if (is_suspended) {
756 *bits |= 0x00100000;
757 return true;
758 }
759 } // end retry loop
760
761 // thread did not suspend after all our retries
762 *bits |= 0x00200000;
763 return false;
764 }
765
766 #ifndef PRODUCT
767 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
768
769 // This should not need to be atomic as the only way for simultaneous
770 // updates is via interrupts. Even then this should be rare or non-existant
771 // and we don't care that much anyway.
772
773 int index = _jmp_ring_index;
774 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
775 _jmp_ring[index]._target = (intptr_t) target;
776 _jmp_ring[index]._instruction = (intptr_t) instr;
777 _jmp_ring[index]._file = file;
778 _jmp_ring[index]._line = line;
779 }
780 #endif /* PRODUCT */
781
782 // Called by flat profiler
783 // Callers have already called wait_for_ext_suspend_completion
784 // The assertion for that is currently too complex to put here:
785 bool JavaThread::profile_last_Java_frame(frame* _fr) {
786 bool gotframe = false;
787 // self suspension saves needed state.
788 if (has_last_Java_frame() && _anchor.walkable()) {
789 *_fr = pd_last_frame();
790 gotframe = true;
791 }
792 return gotframe;
793 }
794
795 void Thread::interrupt(Thread* thread) {
796 trace("interrupt", thread);
797 debug_only(check_for_dangling_thread_pointer(thread);)
798 os::interrupt(thread);
799 }
800
801 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
802 trace("is_interrupted", thread);
803 debug_only(check_for_dangling_thread_pointer(thread);)
804 // Note: If clear_interrupted==false, this simply fetches and
805 // returns the value of the field osthread()->interrupted().
806 return os::is_interrupted(thread, clear_interrupted);
807 }
808
809
810 // GC Support
811 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
812 jint thread_parity = _oops_do_parity;
813 if (thread_parity != strong_roots_parity) {
814 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
815 if (res == thread_parity) {
816 return true;
817 } else {
818 guarantee(res == strong_roots_parity, "Or else what?");
819 assert(SharedHeap::heap()->workers()->active_workers() > 0,
820 "Should only fail when parallel.");
821 return false;
822 }
823 }
824 assert(SharedHeap::heap()->workers()->active_workers() > 0,
825 "Should only fail when parallel.");
826 return false;
827 }
828
829 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
830 active_handles()->oops_do(f);
831 // Do oop for ThreadShadow
832 f->do_oop((oop*)&_pending_exception);
833 handle_area()->oops_do(f);
834 }
835
836 void Thread::nmethods_do(CodeBlobClosure* cf) {
837 // no nmethods in a generic thread...
838 }
839
840 void Thread::metadata_do(void f(Metadata*)) {
841 if (metadata_handles() != NULL) {
842 for (int i = 0; i< metadata_handles()->length(); i++) {
843 f(metadata_handles()->at(i));
844 }
845 }
846 }
847
848 void Thread::print_on(outputStream* st) const {
849 // get_priority assumes osthread initialized
850 if (osthread() != NULL) {
851 int os_prio;
852 if (os::get_native_priority(this, &os_prio) == OS_OK) {
853 st->print("os_prio=%d ", os_prio);
854 }
855 st->print("tid=" INTPTR_FORMAT " ", this);
856 osthread()->print_on(st);
857 }
858 debug_only(if (WizardMode) print_owned_locks_on(st);)
859 }
860
861 // Thread::print_on_error() is called by fatal error handler. Don't use
862 // any lock or allocate memory.
863 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
864 if (is_VM_thread()) st->print("VMThread");
865 else if (is_Compiler_thread()) st->print("CompilerThread");
866 else if (is_Java_thread()) st->print("JavaThread");
867 else if (is_GC_task_thread()) st->print("GCTaskThread");
868 else if (is_Watcher_thread()) st->print("WatcherThread");
869 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
870 else st->print("Thread");
871
872 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
873 _stack_base - _stack_size, _stack_base);
874
875 if (osthread()) {
876 st->print(" [id=%d]", osthread()->thread_id());
877 }
878 }
879
880 #ifdef ASSERT
881 void Thread::print_owned_locks_on(outputStream* st) const {
882 Monitor *cur = _owned_locks;
883 if (cur == NULL) {
884 st->print(" (no locks) ");
885 } else {
886 st->print_cr(" Locks owned:");
887 while(cur) {
888 cur->print_on(st);
889 cur = cur->next();
890 }
891 }
892 }
893
894 static int ref_use_count = 0;
895
896 bool Thread::owns_locks_but_compiled_lock() const {
897 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
898 if (cur != Compile_lock) return true;
899 }
900 return false;
901 }
902
903
904 #endif
905
906 #ifndef PRODUCT
907
908 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
909 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
910 // no threads which allow_vm_block's are held
911 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
912 // Check if current thread is allowed to block at a safepoint
913 if (!(_allow_safepoint_count == 0))
914 fatal("Possible safepoint reached by thread that does not allow it");
915 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
916 fatal("LEAF method calling lock?");
917 }
918
919 #ifdef ASSERT
920 if (potential_vm_operation && is_Java_thread()
921 && !Universe::is_bootstrapping()) {
922 // Make sure we do not hold any locks that the VM thread also uses.
923 // This could potentially lead to deadlocks
924 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
925 // Threads_lock is special, since the safepoint synchronization will not start before this is
926 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
927 // since it is used to transfer control between JavaThreads and the VMThread
928 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
929 if ( (cur->allow_vm_block() &&
930 cur != Threads_lock &&
931 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
932 cur != VMOperationRequest_lock &&
933 cur != VMOperationQueue_lock) ||
934 cur->rank() == Mutex::special) {
935 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
936 }
937 }
938 }
939
940 if (GCALotAtAllSafepoints) {
941 // We could enter a safepoint here and thus have a gc
942 InterfaceSupport::check_gc_alot();
943 }
944 #endif
945 }
946 #endif
947
948 bool Thread::is_in_stack(address adr) const {
949 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
950 address end = os::current_stack_pointer();
951 // Allow non Java threads to call this without stack_base
952 if (_stack_base == NULL) return true;
953 if (stack_base() >= adr && adr >= end) return true;
954
955 return false;
956 }
957
958
959 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
960 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
961 // used for compilation in the future. If that change is made, the need for these methods
962 // should be revisited, and they should be removed if possible.
963
964 bool Thread::is_lock_owned(address adr) const {
965 return on_local_stack(adr);
966 }
967
968 bool Thread::set_as_starting_thread() {
969 // NOTE: this must be called inside the main thread.
970 return os::create_main_thread((JavaThread*)this);
971 }
972
973 static void initialize_class(Symbol* class_name, TRAPS) {
974 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
975 InstanceKlass::cast(klass)->initialize(CHECK);
976 }
977
978
979 // Creates the initial ThreadGroup
980 static Handle create_initial_thread_group(TRAPS) {
981 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
982 instanceKlassHandle klass (THREAD, k);
983
984 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
985 {
986 JavaValue result(T_VOID);
987 JavaCalls::call_special(&result,
988 system_instance,
989 klass,
990 vmSymbols::object_initializer_name(),
991 vmSymbols::void_method_signature(),
992 CHECK_NH);
993 }
994 Universe::set_system_thread_group(system_instance());
995
996 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
997 {
998 JavaValue result(T_VOID);
999 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
1000 JavaCalls::call_special(&result,
1001 main_instance,
1002 klass,
1003 vmSymbols::object_initializer_name(),
1004 vmSymbols::threadgroup_string_void_signature(),
1005 system_instance,
1006 string,
1007 CHECK_NH);
1008 }
1009 return main_instance;
1010 }
1011
1012 // Creates the initial Thread
1013 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
1014 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
1015 instanceKlassHandle klass (THREAD, k);
1016 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
1017
1018 java_lang_Thread::set_thread(thread_oop(), thread);
1019 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1020 thread->set_threadObj(thread_oop());
1021
1022 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
1023
1024 JavaValue result(T_VOID);
1025 JavaCalls::call_special(&result, thread_oop,
1026 klass,
1027 vmSymbols::object_initializer_name(),
1028 vmSymbols::threadgroup_string_void_signature(),
1029 thread_group,
1030 string,
1031 CHECK_NULL);
1032 return thread_oop();
1033 }
1034
1035 static void call_initializeSystemClass(TRAPS) {
1036 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1037 instanceKlassHandle klass (THREAD, k);
1038
1039 JavaValue result(T_VOID);
1040 JavaCalls::call_static(&result, klass, vmSymbols::initializeSystemClass_name(),
1041 vmSymbols::void_method_signature(), CHECK);
1042 }
1043
1044 char java_runtime_name[128] = "";
1045 char java_runtime_version[128] = "";
1046
1047 // extract the JRE name from sun.misc.Version.java_runtime_name
1048 static const char* get_java_runtime_name(TRAPS) {
1049 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1050 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1051 fieldDescriptor fd;
1052 bool found = k != NULL &&
1053 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(),
1054 vmSymbols::string_signature(), &fd);
1055 if (found) {
1056 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1057 if (name_oop == NULL)
1058 return NULL;
1059 const char* name = java_lang_String::as_utf8_string(name_oop,
1060 java_runtime_name,
1061 sizeof(java_runtime_name));
1062 return name;
1063 } else {
1064 return NULL;
1065 }
1066 }
1067
1068 // extract the JRE version from sun.misc.Version.java_runtime_version
1069 static const char* get_java_runtime_version(TRAPS) {
1070 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1071 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1072 fieldDescriptor fd;
1073 bool found = k != NULL &&
1074 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_version_name(),
1075 vmSymbols::string_signature(), &fd);
1076 if (found) {
1077 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1078 if (name_oop == NULL)
1079 return NULL;
1080 const char* name = java_lang_String::as_utf8_string(name_oop,
1081 java_runtime_version,
1082 sizeof(java_runtime_version));
1083 return name;
1084 } else {
1085 return NULL;
1086 }
1087 }
1088
1089 // General purpose hook into Java code, run once when the VM is initialized.
1090 // The Java library method itself may be changed independently from the VM.
1091 static void call_postVMInitHook(TRAPS) {
1092 Klass* k = SystemDictionary::PostVMInitHook_klass();
1093 instanceKlassHandle klass (THREAD, k);
1094 if (klass.not_null()) {
1095 JavaValue result(T_VOID);
1096 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
1097 vmSymbols::void_method_signature(),
1098 CHECK);
1099 }
1100 }
1101
1102 static void reset_vm_info_property(TRAPS) {
1103 // the vm info string
1104 ResourceMark rm(THREAD);
1105 const char *vm_info = VM_Version::vm_info_string();
1106
1107 // java.lang.System class
1108 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1109 instanceKlassHandle klass (THREAD, k);
1110
1111 // setProperty arguments
1112 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
1113 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
1114
1115 // return value
1116 JavaValue r(T_OBJECT);
1117
1118 // public static String setProperty(String key, String value);
1119 JavaCalls::call_static(&r,
1120 klass,
1121 vmSymbols::setProperty_name(),
1122 vmSymbols::string_string_string_signature(),
1123 key_str,
1124 value_str,
1125 CHECK);
1126 }
1127
1128
1129 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
1130 assert(thread_group.not_null(), "thread group should be specified");
1131 assert(threadObj() == NULL, "should only create Java thread object once");
1132
1133 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
1134 instanceKlassHandle klass (THREAD, k);
1135 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
1136
1137 java_lang_Thread::set_thread(thread_oop(), this);
1138 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1139 set_threadObj(thread_oop());
1140
1141 JavaValue result(T_VOID);
1142 if (thread_name != NULL) {
1143 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
1144 // Thread gets assigned specified name and null target
1145 JavaCalls::call_special(&result,
1146 thread_oop,
1147 klass,
1148 vmSymbols::object_initializer_name(),
1149 vmSymbols::threadgroup_string_void_signature(),
1150 thread_group, // Argument 1
1151 name, // Argument 2
1152 THREAD);
1153 } else {
1154 // Thread gets assigned name "Thread-nnn" and null target
1155 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
1156 JavaCalls::call_special(&result,
1157 thread_oop,
1158 klass,
1159 vmSymbols::object_initializer_name(),
1160 vmSymbols::threadgroup_runnable_void_signature(),
1161 thread_group, // Argument 1
1162 Handle(), // Argument 2
1163 THREAD);
1164 }
1165
1166
1167 if (daemon) {
1168 java_lang_Thread::set_daemon(thread_oop());
1169 }
1170
1171 if (HAS_PENDING_EXCEPTION) {
1172 return;
1173 }
1174
1175 KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
1176 Handle threadObj(this, this->threadObj());
1177
1178 JavaCalls::call_special(&result,
1179 thread_group,
1180 group,
1181 vmSymbols::add_method_name(),
1182 vmSymbols::thread_void_signature(),
1183 threadObj, // Arg 1
1184 THREAD);
1185
1186
1187 }
1188
1189 // NamedThread -- non-JavaThread subclasses with multiple
1190 // uniquely named instances should derive from this.
1191 NamedThread::NamedThread() : Thread() {
1192 _name = NULL;
1193 _processed_thread = NULL;
1194 }
1195
1196 NamedThread::~NamedThread() {
1197 if (_name != NULL) {
1198 FREE_C_HEAP_ARRAY(char, _name, mtThread);
1199 _name = NULL;
1200 }
1201 }
1202
1203 void NamedThread::set_name(const char* format, ...) {
1204 guarantee(_name == NULL, "Only get to set name once.");
1205 _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);
1206 guarantee(_name != NULL, "alloc failure");
1207 va_list ap;
1208 va_start(ap, format);
1209 jio_vsnprintf(_name, max_name_len, format, ap);
1210 va_end(ap);
1211 }
1212
1213 // ======= WatcherThread ========
1214
1215 // The watcher thread exists to simulate timer interrupts. It should
1216 // be replaced by an abstraction over whatever native support for
1217 // timer interrupts exists on the platform.
1218
1219 WatcherThread* WatcherThread::_watcher_thread = NULL;
1220 bool WatcherThread::_startable = false;
1221 volatile bool WatcherThread::_should_terminate = false;
1222
1223 WatcherThread::WatcherThread() : Thread() {
1224 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1225 if (os::create_thread(this, os::watcher_thread)) {
1226 _watcher_thread = this;
1227
1228 // Set the watcher thread to the highest OS priority which should not be
1229 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1230 // is created. The only normal thread using this priority is the reference
1231 // handler thread, which runs for very short intervals only.
1232 // If the VMThread's priority is not lower than the WatcherThread profiling
1233 // will be inaccurate.
1234 os::set_priority(this, MaxPriority);
1235 if (!DisableStartThread) {
1236 os::start_thread(this);
1237 }
1238 }
1239 }
1240
1241 int WatcherThread::sleep() const {
1242 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1243
1244 // remaining will be zero if there are no tasks,
1245 // causing the WatcherThread to sleep until a task is
1246 // enrolled
1247 int remaining = PeriodicTask::time_to_wait();
1248 int time_slept = 0;
1249
1250 // we expect this to timeout - we only ever get unparked when
1251 // we should terminate or when a new task has been enrolled
1252 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1253
1254 jlong time_before_loop = os::javaTimeNanos();
1255
1256 for (;;) {
1257 bool timedout = PeriodicTask_lock->wait(Mutex::_no_safepoint_check_flag, remaining);
1258 jlong now = os::javaTimeNanos();
1259
1260 if (remaining == 0) {
1261 // if we didn't have any tasks we could have waited for a long time
1262 // consider the time_slept zero and reset time_before_loop
1263 time_slept = 0;
1264 time_before_loop = now;
1265 } else {
1266 // need to recalulate since we might have new tasks in _tasks
1267 time_slept = (int) ((now - time_before_loop) / 1000000);
1268 }
1269
1270 // Change to task list or spurious wakeup of some kind
1271 if (timedout || _should_terminate) {
1272 break;
1273 }
1274
1275 remaining = PeriodicTask::time_to_wait();
1276 if (remaining == 0) {
1277 // Last task was just disenrolled so loop around and wait until
1278 // another task gets enrolled
1279 continue;
1280 }
1281
1282 remaining -= time_slept;
1283 if (remaining <= 0)
1284 break;
1285 }
1286
1287 return time_slept;
1288 }
1289
1290 void WatcherThread::run() {
1291 assert(this == watcher_thread(), "just checking");
1292
1293 this->record_stack_base_and_size();
1294 this->initialize_thread_local_storage();
1295 this->set_active_handles(JNIHandleBlock::allocate_block());
1296 while(!_should_terminate) {
1297 assert(watcher_thread() == Thread::current(), "thread consistency check");
1298 assert(watcher_thread() == this, "thread consistency check");
1299
1300 // Calculate how long it'll be until the next PeriodicTask work
1301 // should be done, and sleep that amount of time.
1302 int time_waited = sleep();
1303
1304 if (is_error_reported()) {
1305 // A fatal error has happened, the error handler(VMError::report_and_die)
1306 // should abort JVM after creating an error log file. However in some
1307 // rare cases, the error handler itself might deadlock. Here we try to
1308 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1309 //
1310 // This code is in WatcherThread because WatcherThread wakes up
1311 // periodically so the fatal error handler doesn't need to do anything;
1312 // also because the WatcherThread is less likely to crash than other
1313 // threads.
1314
1315 for (;;) {
1316 if (!ShowMessageBoxOnError
1317 && (OnError == NULL || OnError[0] == '\0')
1318 && Arguments::abort_hook() == NULL) {
1319 os::sleep(this, 2 * 60 * 1000, false);
1320 fdStream err(defaultStream::output_fd());
1321 err.print_raw_cr("# [ timer expired, abort... ]");
1322 // skip atexit/vm_exit/vm_abort hooks
1323 os::die();
1324 }
1325
1326 // Wake up 5 seconds later, the fatal handler may reset OnError or
1327 // ShowMessageBoxOnError when it is ready to abort.
1328 os::sleep(this, 5 * 1000, false);
1329 }
1330 }
1331
1332 PeriodicTask::real_time_tick(time_waited);
1333 }
1334
1335 // Signal that it is terminated
1336 {
1337 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1338 _watcher_thread = NULL;
1339 Terminator_lock->notify();
1340 }
1341
1342 // Thread destructor usually does this..
1343 ThreadLocalStorage::set_thread(NULL);
1344 }
1345
1346 void WatcherThread::start() {
1347 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1348
1349 if (watcher_thread() == NULL && _startable) {
1350 _should_terminate = false;
1351 // Create the single instance of WatcherThread
1352 new WatcherThread();
1353 }
1354 }
1355
1356 void WatcherThread::make_startable() {
1357 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1358 _startable = true;
1359 }
1360
1361 void WatcherThread::stop() {
1362 {
1363 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1364 _should_terminate = true;
1365 OrderAccess::fence(); // ensure WatcherThread sees update in main loop
1366
1367 WatcherThread* watcher = watcher_thread();
1368 if (watcher != NULL)
1369 watcher->unpark();
1370 }
1371
1372 // it is ok to take late safepoints here, if needed
1373 MutexLocker mu(Terminator_lock);
1374
1375 while(watcher_thread() != NULL) {
1376 // This wait should make safepoint checks, wait without a timeout,
1377 // and wait as a suspend-equivalent condition.
1378 //
1379 // Note: If the FlatProfiler is running, then this thread is waiting
1380 // for the WatcherThread to terminate and the WatcherThread, via the
1381 // FlatProfiler task, is waiting for the external suspend request on
1382 // this thread to complete. wait_for_ext_suspend_completion() will
1383 // eventually timeout, but that takes time. Making this wait a
1384 // suspend-equivalent condition solves that timeout problem.
1385 //
1386 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1387 Mutex::_as_suspend_equivalent_flag);
1388 }
1389 }
1390
1391 void WatcherThread::unpark() {
1392 MutexLockerEx ml(PeriodicTask_lock->owned_by_self() ? NULL : PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1393 PeriodicTask_lock->notify();
1394 }
1395
1396 void WatcherThread::print_on(outputStream* st) const {
1397 st->print("\"%s\" ", name());
1398 Thread::print_on(st);
1399 st->cr();
1400 }
1401
1402 // ======= JavaThread ========
1403
1404 // A JavaThread is a normal Java thread
1405
1406 void JavaThread::initialize() {
1407 // Initialize fields
1408
1409 // Set the claimed par_id to -1 (ie not claiming any par_ids)
1410 set_claimed_par_id(-1);
1411
1412 set_saved_exception_pc(NULL);
1413 set_threadObj(NULL);
1414 _anchor.clear();
1415 set_entry_point(NULL);
1416 set_jni_functions(jni_functions());
1417 set_callee_target(NULL);
1418 set_vm_result(NULL);
1419 set_vm_result_2(NULL);
1420 set_vframe_array_head(NULL);
1421 set_vframe_array_last(NULL);
1422 set_deferred_locals(NULL);
1423 set_deopt_mark(NULL);
1424 set_deopt_nmethod(NULL);
1425 clear_must_deopt_id();
1426 set_monitor_chunks(NULL);
1427 set_next(NULL);
1428 set_thread_state(_thread_new);
1429 #if INCLUDE_NMT
1430 set_recorder(NULL);
1431 #endif
1432 _terminated = _not_terminated;
1433 _privileged_stack_top = NULL;
1434 _array_for_gc = NULL;
1435 _suspend_equivalent = false;
1436 _in_deopt_handler = 0;
1437 _doing_unsafe_access = false;
1438 _stack_guard_state = stack_guard_unused;
1439 _exception_oop = NULL;
1440 _exception_pc = 0;
1441 _exception_handler_pc = 0;
1442 _is_method_handle_return = 0;
1443 _jvmti_thread_state= NULL;
1444 _should_post_on_exceptions_flag = JNI_FALSE;
1445 _jvmti_get_loaded_classes_closure = NULL;
1446 _interp_only_mode = 0;
1447 _special_runtime_exit_condition = _no_async_condition;
1448 _pending_async_exception = NULL;
1449 _is_compiling = false;
1450 _thread_stat = NULL;
1451 _thread_stat = new ThreadStatistics();
1452 _blocked_on_compilation = false;
1453 _jni_active_critical = 0;
1454 _do_not_unlock_if_synchronized = false;
1455 _cached_monitor_info = NULL;
1456 _parker = Parker::Allocate(this) ;
1457
1458 #ifndef PRODUCT
1459 _jmp_ring_index = 0;
1460 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1461 record_jump(NULL, NULL, NULL, 0);
1462 }
1463 #endif /* PRODUCT */
1464
1465 set_thread_profiler(NULL);
1466 if (FlatProfiler::is_active()) {
1467 // This is where we would decide to either give each thread it's own profiler
1468 // or use one global one from FlatProfiler,
1469 // or up to some count of the number of profiled threads, etc.
1470 ThreadProfiler* pp = new ThreadProfiler();
1471 pp->engage();
1472 set_thread_profiler(pp);
1473 }
1474
1475 // Setup safepoint state info for this thread
1476 ThreadSafepointState::create(this);
1477
1478 debug_only(_java_call_counter = 0);
1479
1480 // JVMTI PopFrame support
1481 _popframe_condition = popframe_inactive;
1482 _popframe_preserved_args = NULL;
1483 _popframe_preserved_args_size = 0;
1484
1485 pd_initialize();
1486 }
1487
1488 #ifndef SERIALGC
1489 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1490 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1491 #endif // !SERIALGC
1492
1493 JavaThread::JavaThread(bool is_attaching_via_jni) :
1494 Thread()
1495 #ifndef SERIALGC
1496 , _satb_mark_queue(&_satb_mark_queue_set),
1497 _dirty_card_queue(&_dirty_card_queue_set)
1498 #endif // !SERIALGC
1499 {
1500 initialize();
1501 if (is_attaching_via_jni) {
1502 _jni_attach_state = _attaching_via_jni;
1503 } else {
1504 _jni_attach_state = _not_attaching_via_jni;
1505 }
1506 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor");
1507 _safepoint_visible = false;
1508 }
1509
1510 bool JavaThread::reguard_stack(address cur_sp) {
1511 if (_stack_guard_state != stack_guard_yellow_disabled) {
1512 return true; // Stack already guarded or guard pages not needed.
1513 }
1514
1515 if (register_stack_overflow()) {
1516 // For those architectures which have separate register and
1517 // memory stacks, we must check the register stack to see if
1518 // it has overflowed.
1519 return false;
1520 }
1521
1522 // Java code never executes within the yellow zone: the latter is only
1523 // there to provoke an exception during stack banging. If java code
1524 // is executing there, either StackShadowPages should be larger, or
1525 // some exception code in c1, c2 or the interpreter isn't unwinding
1526 // when it should.
1527 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1528
1529 enable_stack_yellow_zone();
1530 return true;
1531 }
1532
1533 bool JavaThread::reguard_stack(void) {
1534 return reguard_stack(os::current_stack_pointer());
1535 }
1536
1537
1538 void JavaThread::block_if_vm_exited() {
1539 if (_terminated == _vm_exited) {
1540 // _vm_exited is set at safepoint, and Threads_lock is never released
1541 // we will block here forever
1542 Threads_lock->lock_without_safepoint_check();
1543 ShouldNotReachHere();
1544 }
1545 }
1546
1547
1548 // Remove this ifdef when C1 is ported to the compiler interface.
1549 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1550
1551 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1552 Thread()
1553 #ifndef SERIALGC
1554 , _satb_mark_queue(&_satb_mark_queue_set),
1555 _dirty_card_queue(&_dirty_card_queue_set)
1556 #endif // !SERIALGC
1557 {
1558 if (TraceThreadEvents) {
1559 tty->print_cr("creating thread %p", this);
1560 }
1561 initialize();
1562 _jni_attach_state = _not_attaching_via_jni;
1563 set_entry_point(entry_point);
1564 // Create the native thread itself.
1565 // %note runtime_23
1566 os::ThreadType thr_type = os::java_thread;
1567 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1568 os::java_thread;
1569 os::create_thread(this, thr_type, stack_sz);
1570 _safepoint_visible = false;
1571 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1572 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1573 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1574 // the exception consists of creating the exception object & initializing it, initialization
1575 // will leave the VM via a JavaCall and then all locks must be unlocked).
1576 //
1577 // The thread is still suspended when we reach here. Thread must be explicit started
1578 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1579 // by calling Threads:add. The reason why this is not done here, is because the thread
1580 // object must be fully initialized (take a look at JVM_Start)
1581 }
1582
1583 JavaThread::~JavaThread() {
1584 if (TraceThreadEvents) {
1585 tty->print_cr("terminate thread %p", this);
1586 }
1587
1588 // By now, this thread should already be invisible to safepoint,
1589 // and its per-thread recorder also collected.
1590 assert(!is_safepoint_visible(), "wrong state");
1591 #if INCLUDE_NMT
1592 assert(get_recorder() == NULL, "Already collected");
1593 #endif // INCLUDE_NMT
1594
1595 // JSR166 -- return the parker to the free list
1596 Parker::Release(_parker);
1597 _parker = NULL ;
1598
1599 // Free any remaining previous UnrollBlock
1600 vframeArray* old_array = vframe_array_last();
1601
1602 if (old_array != NULL) {
1603 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1604 old_array->set_unroll_block(NULL);
1605 delete old_info;
1606 delete old_array;
1607 }
1608
1609 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1610 if (deferred != NULL) {
1611 // This can only happen if thread is destroyed before deoptimization occurs.
1612 assert(deferred->length() != 0, "empty array!");
1613 do {
1614 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1615 deferred->remove_at(0);
1616 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1617 delete dlv;
1618 } while (deferred->length() != 0);
1619 delete deferred;
1620 }
1621
1622 // All Java related clean up happens in exit
1623 ThreadSafepointState::destroy(this);
1624 if (_thread_profiler != NULL) delete _thread_profiler;
1625 if (_thread_stat != NULL) delete _thread_stat;
1626 }
1627
1628
1629 // The first routine called by a new Java thread
1630 void JavaThread::run() {
1631 // initialize thread-local alloc buffer related fields
1632 this->initialize_tlab();
1633
1634 // used to test validitity of stack trace backs
1635 this->record_base_of_stack_pointer();
1636
1637 // Record real stack base and size.
1638 this->record_stack_base_and_size();
1639
1640 // Initialize thread local storage; set before calling MutexLocker
1641 this->initialize_thread_local_storage();
1642
1643 this->create_stack_guard_pages();
1644
1645 this->cache_global_variables();
1646
1647 // Thread is now sufficient initialized to be handled by the safepoint code as being
1648 // in the VM. Change thread state from _thread_new to _thread_in_vm
1649 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1650
1651 assert(JavaThread::current() == this, "sanity check");
1652 assert(!Thread::current()->owns_locks(), "sanity check");
1653
1654 DTRACE_THREAD_PROBE(start, this);
1655
1656 // This operation might block. We call that after all safepoint checks for a new thread has
1657 // been completed.
1658 this->set_active_handles(JNIHandleBlock::allocate_block());
1659
1660 if (JvmtiExport::should_post_thread_life()) {
1661 JvmtiExport::post_thread_start(this);
1662 }
1663
1664 EVENT_BEGIN(TraceEventThreadStart, event);
1665 EVENT_COMMIT(event,
1666 EVENT_SET(event, javalangthread, java_lang_Thread::thread_id(this->threadObj())));
1667
1668 // We call another function to do the rest so we are sure that the stack addresses used
1669 // from there will be lower than the stack base just computed
1670 thread_main_inner();
1671
1672 // Note, thread is no longer valid at this point!
1673 }
1674
1675
1676 void JavaThread::thread_main_inner() {
1677 assert(JavaThread::current() == this, "sanity check");
1678 assert(this->threadObj() != NULL, "just checking");
1679
1680 // Execute thread entry point unless this thread has a pending exception
1681 // or has been stopped before starting.
1682 // Note: Due to JVM_StopThread we can have pending exceptions already!
1683 if (!this->has_pending_exception() &&
1684 !java_lang_Thread::is_stillborn(this->threadObj())) {
1685 {
1686 ResourceMark rm(this);
1687 this->set_native_thread_name(this->get_thread_name());
1688 }
1689 HandleMark hm(this);
1690 this->entry_point()(this, this);
1691 }
1692
1693 DTRACE_THREAD_PROBE(stop, this);
1694
1695 this->exit(false);
1696 delete this;
1697 }
1698
1699
1700 static void ensure_join(JavaThread* thread) {
1701 // We do not need to grap the Threads_lock, since we are operating on ourself.
1702 Handle threadObj(thread, thread->threadObj());
1703 assert(threadObj.not_null(), "java thread object must exist");
1704 ObjectLocker lock(threadObj, thread);
1705 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1706 thread->clear_pending_exception();
1707 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1708 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1709 // Clear the native thread instance - this makes isAlive return false and allows the join()
1710 // to complete once we've done the notify_all below
1711 java_lang_Thread::set_thread(threadObj(), NULL);
1712 lock.notify_all(thread);
1713 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1714 thread->clear_pending_exception();
1715 }
1716
1717
1718 // For any new cleanup additions, please check to see if they need to be applied to
1719 // cleanup_failed_attach_current_thread as well.
1720 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1721 assert(this == JavaThread::current(), "thread consistency check");
1722 if (!InitializeJavaLangSystem) return;
1723
1724 HandleMark hm(this);
1725 Handle uncaught_exception(this, this->pending_exception());
1726 this->clear_pending_exception();
1727 Handle threadObj(this, this->threadObj());
1728 assert(threadObj.not_null(), "Java thread object should be created");
1729
1730 if (get_thread_profiler() != NULL) {
1731 get_thread_profiler()->disengage();
1732 ResourceMark rm;
1733 get_thread_profiler()->print(get_thread_name());
1734 }
1735
1736
1737 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1738 {
1739 EXCEPTION_MARK;
1740
1741 CLEAR_PENDING_EXCEPTION;
1742 }
1743 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1744 // has to be fixed by a runtime query method
1745 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1746 // JSR-166: change call from from ThreadGroup.uncaughtException to
1747 // java.lang.Thread.dispatchUncaughtException
1748 if (uncaught_exception.not_null()) {
1749 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1750 {
1751 EXCEPTION_MARK;
1752 // Check if the method Thread.dispatchUncaughtException() exists. If so
1753 // call it. Otherwise we have an older library without the JSR-166 changes,
1754 // so call ThreadGroup.uncaughtException()
1755 KlassHandle recvrKlass(THREAD, threadObj->klass());
1756 CallInfo callinfo;
1757 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1758 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1759 vmSymbols::dispatchUncaughtException_name(),
1760 vmSymbols::throwable_void_signature(),
1761 KlassHandle(), false, false, THREAD);
1762 CLEAR_PENDING_EXCEPTION;
1763 methodHandle method = callinfo.selected_method();
1764 if (method.not_null()) {
1765 JavaValue result(T_VOID);
1766 JavaCalls::call_virtual(&result,
1767 threadObj, thread_klass,
1768 vmSymbols::dispatchUncaughtException_name(),
1769 vmSymbols::throwable_void_signature(),
1770 uncaught_exception,
1771 THREAD);
1772 } else {
1773 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1774 JavaValue result(T_VOID);
1775 JavaCalls::call_virtual(&result,
1776 group, thread_group,
1777 vmSymbols::uncaughtException_name(),
1778 vmSymbols::thread_throwable_void_signature(),
1779 threadObj, // Arg 1
1780 uncaught_exception, // Arg 2
1781 THREAD);
1782 }
1783 if (HAS_PENDING_EXCEPTION) {
1784 ResourceMark rm(this);
1785 jio_fprintf(defaultStream::error_stream(),
1786 "\nException: %s thrown from the UncaughtExceptionHandler"
1787 " in thread \"%s\"\n",
1788 pending_exception()->klass()->external_name(),
1789 get_thread_name());
1790 CLEAR_PENDING_EXCEPTION;
1791 }
1792 }
1793 }
1794
1795 // Called before the java thread exit since we want to read info
1796 // from java_lang_Thread object
1797 EVENT_BEGIN(TraceEventThreadEnd, event);
1798 EVENT_COMMIT(event,
1799 EVENT_SET(event, javalangthread, java_lang_Thread::thread_id(this->threadObj())));
1800
1801 // Call after last event on thread
1802 EVENT_THREAD_EXIT(this);
1803
1804 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1805 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1806 // is deprecated anyhow.
1807 { int count = 3;
1808 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1809 EXCEPTION_MARK;
1810 JavaValue result(T_VOID);
1811 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1812 JavaCalls::call_virtual(&result,
1813 threadObj, thread_klass,
1814 vmSymbols::exit_method_name(),
1815 vmSymbols::void_method_signature(),
1816 THREAD);
1817 CLEAR_PENDING_EXCEPTION;
1818 }
1819 }
1820
1821 // notify JVMTI
1822 if (JvmtiExport::should_post_thread_life()) {
1823 JvmtiExport::post_thread_end(this);
1824 }
1825
1826 // We have notified the agents that we are exiting, before we go on,
1827 // we must check for a pending external suspend request and honor it
1828 // in order to not surprise the thread that made the suspend request.
1829 while (true) {
1830 {
1831 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1832 if (!is_external_suspend()) {
1833 set_terminated(_thread_exiting);
1834 ThreadService::current_thread_exiting(this);
1835 break;
1836 }
1837 // Implied else:
1838 // Things get a little tricky here. We have a pending external
1839 // suspend request, but we are holding the SR_lock so we
1840 // can't just self-suspend. So we temporarily drop the lock
1841 // and then self-suspend.
1842 }
1843
1844 ThreadBlockInVM tbivm(this);
1845 java_suspend_self();
1846
1847 // We're done with this suspend request, but we have to loop around
1848 // and check again. Eventually we will get SR_lock without a pending
1849 // external suspend request and will be able to mark ourselves as
1850 // exiting.
1851 }
1852 // no more external suspends are allowed at this point
1853 } else {
1854 // before_exit() has already posted JVMTI THREAD_END events
1855 }
1856
1857 // Notify waiters on thread object. This has to be done after exit() is called
1858 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1859 // group should have the destroyed bit set before waiters are notified).
1860 ensure_join(this);
1861 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1862
1863 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1864 // held by this thread must be released. A detach operation must only
1865 // get here if there are no Java frames on the stack. Therefore, any
1866 // owned monitors at this point MUST be JNI-acquired monitors which are
1867 // pre-inflated and in the monitor cache.
1868 //
1869 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1870 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1871 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1872 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1873 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1874 }
1875
1876 // These things needs to be done while we are still a Java Thread. Make sure that thread
1877 // is in a consistent state, in case GC happens
1878 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1879
1880 if (active_handles() != NULL) {
1881 JNIHandleBlock* block = active_handles();
1882 set_active_handles(NULL);
1883 JNIHandleBlock::release_block(block);
1884 }
1885
1886 if (free_handle_block() != NULL) {
1887 JNIHandleBlock* block = free_handle_block();
1888 set_free_handle_block(NULL);
1889 JNIHandleBlock::release_block(block);
1890 }
1891
1892 // These have to be removed while this is still a valid thread.
1893 remove_stack_guard_pages();
1894
1895 if (UseTLAB) {
1896 tlab().make_parsable(true); // retire TLAB
1897 }
1898
1899 if (JvmtiEnv::environments_might_exist()) {
1900 JvmtiExport::cleanup_thread(this);
1901 }
1902
1903 #ifndef SERIALGC
1904 // We must flush G1-related buffers before removing a thread from
1905 // the list of active threads.
1906 if (UseG1GC) {
1907 flush_barrier_queues();
1908 }
1909 #endif
1910
1911 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1912 Threads::remove(this);
1913 }
1914
1915 #ifndef SERIALGC
1916 // Flush G1-related queues.
1917 void JavaThread::flush_barrier_queues() {
1918 satb_mark_queue().flush();
1919 dirty_card_queue().flush();
1920 }
1921
1922 void JavaThread::initialize_queues() {
1923 assert(!SafepointSynchronize::is_at_safepoint(),
1924 "we should not be at a safepoint");
1925
1926 ObjPtrQueue& satb_queue = satb_mark_queue();
1927 SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
1928 // The SATB queue should have been constructed with its active
1929 // field set to false.
1930 assert(!satb_queue.is_active(), "SATB queue should not be active");
1931 assert(satb_queue.is_empty(), "SATB queue should be empty");
1932 // If we are creating the thread during a marking cycle, we should
1933 // set the active field of the SATB queue to true.
1934 if (satb_queue_set.is_active()) {
1935 satb_queue.set_active(true);
1936 }
1937
1938 DirtyCardQueue& dirty_queue = dirty_card_queue();
1939 // The dirty card queue should have been constructed with its
1940 // active field set to true.
1941 assert(dirty_queue.is_active(), "dirty card queue should be active");
1942 }
1943 #endif // !SERIALGC
1944
1945 void JavaThread::cleanup_failed_attach_current_thread() {
1946 if (get_thread_profiler() != NULL) {
1947 get_thread_profiler()->disengage();
1948 ResourceMark rm;
1949 get_thread_profiler()->print(get_thread_name());
1950 }
1951
1952 if (active_handles() != NULL) {
1953 JNIHandleBlock* block = active_handles();
1954 set_active_handles(NULL);
1955 JNIHandleBlock::release_block(block);
1956 }
1957
1958 if (free_handle_block() != NULL) {
1959 JNIHandleBlock* block = free_handle_block();
1960 set_free_handle_block(NULL);
1961 JNIHandleBlock::release_block(block);
1962 }
1963
1964 // These have to be removed while this is still a valid thread.
1965 remove_stack_guard_pages();
1966
1967 if (UseTLAB) {
1968 tlab().make_parsable(true); // retire TLAB, if any
1969 }
1970
1971 #ifndef SERIALGC
1972 if (UseG1GC) {
1973 flush_barrier_queues();
1974 }
1975 #endif
1976
1977 Threads::remove(this);
1978 delete this;
1979 }
1980
1981
1982
1983
1984 JavaThread* JavaThread::active() {
1985 Thread* thread = ThreadLocalStorage::thread();
1986 assert(thread != NULL, "just checking");
1987 if (thread->is_Java_thread()) {
1988 return (JavaThread*) thread;
1989 } else {
1990 assert(thread->is_VM_thread(), "this must be a vm thread");
1991 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1992 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1993 assert(ret->is_Java_thread(), "must be a Java thread");
1994 return ret;
1995 }
1996 }
1997
1998 bool JavaThread::is_lock_owned(address adr) const {
1999 if (Thread::is_lock_owned(adr)) return true;
2000
2001 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2002 if (chunk->contains(adr)) return true;
2003 }
2004
2005 return false;
2006 }
2007
2008
2009 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
2010 chunk->set_next(monitor_chunks());
2011 set_monitor_chunks(chunk);
2012 }
2013
2014 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
2015 guarantee(monitor_chunks() != NULL, "must be non empty");
2016 if (monitor_chunks() == chunk) {
2017 set_monitor_chunks(chunk->next());
2018 } else {
2019 MonitorChunk* prev = monitor_chunks();
2020 while (prev->next() != chunk) prev = prev->next();
2021 prev->set_next(chunk->next());
2022 }
2023 }
2024
2025 // JVM support.
2026
2027 // Note: this function shouldn't block if it's called in
2028 // _thread_in_native_trans state (such as from
2029 // check_special_condition_for_native_trans()).
2030 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
2031
2032 if (has_last_Java_frame() && has_async_condition()) {
2033 // If we are at a polling page safepoint (not a poll return)
2034 // then we must defer async exception because live registers
2035 // will be clobbered by the exception path. Poll return is
2036 // ok because the call we a returning from already collides
2037 // with exception handling registers and so there is no issue.
2038 // (The exception handling path kills call result registers but
2039 // this is ok since the exception kills the result anyway).
2040
2041 if (is_at_poll_safepoint()) {
2042 // if the code we are returning to has deoptimized we must defer
2043 // the exception otherwise live registers get clobbered on the
2044 // exception path before deoptimization is able to retrieve them.
2045 //
2046 RegisterMap map(this, false);
2047 frame caller_fr = last_frame().sender(&map);
2048 assert(caller_fr.is_compiled_frame(), "what?");
2049 if (caller_fr.is_deoptimized_frame()) {
2050 if (TraceExceptions) {
2051 ResourceMark rm;
2052 tty->print_cr("deferred async exception at compiled safepoint");
2053 }
2054 return;
2055 }
2056 }
2057 }
2058
2059 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
2060 if (condition == _no_async_condition) {
2061 // Conditions have changed since has_special_runtime_exit_condition()
2062 // was called:
2063 // - if we were here only because of an external suspend request,
2064 // then that was taken care of above (or cancelled) so we are done
2065 // - if we were here because of another async request, then it has
2066 // been cleared between the has_special_runtime_exit_condition()
2067 // and now so again we are done
2068 return;
2069 }
2070
2071 // Check for pending async. exception
2072 if (_pending_async_exception != NULL) {
2073 // Only overwrite an already pending exception, if it is not a threadDeath.
2074 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
2075
2076 // We cannot call Exceptions::_throw(...) here because we cannot block
2077 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
2078
2079 if (TraceExceptions) {
2080 ResourceMark rm;
2081 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
2082 if (has_last_Java_frame() ) {
2083 frame f = last_frame();
2084 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
2085 }
2086 tty->print_cr(" of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2087 }
2088 _pending_async_exception = NULL;
2089 clear_has_async_exception();
2090 }
2091 }
2092
2093 if (check_unsafe_error &&
2094 condition == _async_unsafe_access_error && !has_pending_exception()) {
2095 condition = _no_async_condition; // done
2096 switch (thread_state()) {
2097 case _thread_in_vm:
2098 {
2099 JavaThread* THREAD = this;
2100 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2101 }
2102 case _thread_in_native:
2103 {
2104 ThreadInVMfromNative tiv(this);
2105 JavaThread* THREAD = this;
2106 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2107 }
2108 case _thread_in_Java:
2109 {
2110 ThreadInVMfromJava tiv(this);
2111 JavaThread* THREAD = this;
2112 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
2113 }
2114 default:
2115 ShouldNotReachHere();
2116 }
2117 }
2118
2119 assert(condition == _no_async_condition || has_pending_exception() ||
2120 (!check_unsafe_error && condition == _async_unsafe_access_error),
2121 "must have handled the async condition, if no exception");
2122 }
2123
2124 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
2125 //
2126 // Check for pending external suspend. Internal suspend requests do
2127 // not use handle_special_runtime_exit_condition().
2128 // If JNIEnv proxies are allowed, don't self-suspend if the target
2129 // thread is not the current thread. In older versions of jdbx, jdbx
2130 // threads could call into the VM with another thread's JNIEnv so we
2131 // can be here operating on behalf of a suspended thread (4432884).
2132 bool do_self_suspend = is_external_suspend_with_lock();
2133 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
2134 //
2135 // Because thread is external suspended the safepoint code will count
2136 // thread as at a safepoint. This can be odd because we can be here
2137 // as _thread_in_Java which would normally transition to _thread_blocked
2138 // at a safepoint. We would like to mark the thread as _thread_blocked
2139 // before calling java_suspend_self like all other callers of it but
2140 // we must then observe proper safepoint protocol. (We can't leave
2141 // _thread_blocked with a safepoint in progress). However we can be
2142 // here as _thread_in_native_trans so we can't use a normal transition
2143 // constructor/destructor pair because they assert on that type of
2144 // transition. We could do something like:
2145 //
2146 // JavaThreadState state = thread_state();
2147 // set_thread_state(_thread_in_vm);
2148 // {
2149 // ThreadBlockInVM tbivm(this);
2150 // java_suspend_self()
2151 // }
2152 // set_thread_state(_thread_in_vm_trans);
2153 // if (safepoint) block;
2154 // set_thread_state(state);
2155 //
2156 // but that is pretty messy. Instead we just go with the way the
2157 // code has worked before and note that this is the only path to
2158 // java_suspend_self that doesn't put the thread in _thread_blocked
2159 // mode.
2160
2161 frame_anchor()->make_walkable(this);
2162 java_suspend_self();
2163
2164 // We might be here for reasons in addition to the self-suspend request
2165 // so check for other async requests.
2166 }
2167
2168 if (check_asyncs) {
2169 check_and_handle_async_exceptions();
2170 }
2171 }
2172
2173 void JavaThread::send_thread_stop(oop java_throwable) {
2174 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
2175 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
2176 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
2177
2178 // Do not throw asynchronous exceptions against the compiler thread
2179 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
2180 if (is_Compiler_thread()) return;
2181
2182 {
2183 // Actually throw the Throwable against the target Thread - however
2184 // only if there is no thread death exception installed already.
2185 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
2186 // If the topmost frame is a runtime stub, then we are calling into
2187 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
2188 // must deoptimize the caller before continuing, as the compiled exception handler table
2189 // may not be valid
2190 if (has_last_Java_frame()) {
2191 frame f = last_frame();
2192 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
2193 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2194 RegisterMap reg_map(this, UseBiasedLocking);
2195 frame compiled_frame = f.sender(®_map);
2196 if (compiled_frame.can_be_deoptimized()) {
2197 Deoptimization::deoptimize(this, compiled_frame, ®_map);
2198 }
2199 }
2200 }
2201
2202 // Set async. pending exception in thread.
2203 set_pending_async_exception(java_throwable);
2204
2205 if (TraceExceptions) {
2206 ResourceMark rm;
2207 tty->print_cr("Pending Async. exception installed of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2208 }
2209 // for AbortVMOnException flag
2210 NOT_PRODUCT(Exceptions::debug_check_abort(InstanceKlass::cast(_pending_async_exception->klass())->external_name()));
2211 }
2212 }
2213
2214
2215 // Interrupt thread so it will wake up from a potential wait()
2216 Thread::interrupt(this);
2217 }
2218
2219 // External suspension mechanism.
2220 //
2221 // Tell the VM to suspend a thread when ever it knows that it does not hold on
2222 // to any VM_locks and it is at a transition
2223 // Self-suspension will happen on the transition out of the vm.
2224 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
2225 //
2226 // Guarantees on return:
2227 // + Target thread will not execute any new bytecode (that's why we need to
2228 // force a safepoint)
2229 // + Target thread will not enter any new monitors
2230 //
2231 void JavaThread::java_suspend() {
2232 { MutexLocker mu(Threads_lock);
2233 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
2234 return;
2235 }
2236 }
2237
2238 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2239 if (!is_external_suspend()) {
2240 // a racing resume has cancelled us; bail out now
2241 return;
2242 }
2243
2244 // suspend is done
2245 uint32_t debug_bits = 0;
2246 // Warning: is_ext_suspend_completed() may temporarily drop the
2247 // SR_lock to allow the thread to reach a stable thread state if
2248 // it is currently in a transient thread state.
2249 if (is_ext_suspend_completed(false /* !called_by_wait */,
2250 SuspendRetryDelay, &debug_bits) ) {
2251 return;
2252 }
2253 }
2254
2255 VM_ForceSafepoint vm_suspend;
2256 VMThread::execute(&vm_suspend);
2257 }
2258
2259 // Part II of external suspension.
2260 // A JavaThread self suspends when it detects a pending external suspend
2261 // request. This is usually on transitions. It is also done in places
2262 // where continuing to the next transition would surprise the caller,
2263 // e.g., monitor entry.
2264 //
2265 // Returns the number of times that the thread self-suspended.
2266 //
2267 // Note: DO NOT call java_suspend_self() when you just want to block current
2268 // thread. java_suspend_self() is the second stage of cooperative
2269 // suspension for external suspend requests and should only be used
2270 // to complete an external suspend request.
2271 //
2272 int JavaThread::java_suspend_self() {
2273 int ret = 0;
2274
2275 // we are in the process of exiting so don't suspend
2276 if (is_exiting()) {
2277 clear_external_suspend();
2278 return ret;
2279 }
2280
2281 assert(_anchor.walkable() ||
2282 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
2283 "must have walkable stack");
2284
2285 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2286
2287 assert(!this->is_ext_suspended(),
2288 "a thread trying to self-suspend should not already be suspended");
2289
2290 if (this->is_suspend_equivalent()) {
2291 // If we are self-suspending as a result of the lifting of a
2292 // suspend equivalent condition, then the suspend_equivalent
2293 // flag is not cleared until we set the ext_suspended flag so
2294 // that wait_for_ext_suspend_completion() returns consistent
2295 // results.
2296 this->clear_suspend_equivalent();
2297 }
2298
2299 // A racing resume may have cancelled us before we grabbed SR_lock
2300 // above. Or another external suspend request could be waiting for us
2301 // by the time we return from SR_lock()->wait(). The thread
2302 // that requested the suspension may already be trying to walk our
2303 // stack and if we return now, we can change the stack out from under
2304 // it. This would be a "bad thing (TM)" and cause the stack walker
2305 // to crash. We stay self-suspended until there are no more pending
2306 // external suspend requests.
2307 while (is_external_suspend()) {
2308 ret++;
2309 this->set_ext_suspended();
2310
2311 // _ext_suspended flag is cleared by java_resume()
2312 while (is_ext_suspended()) {
2313 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2314 }
2315 }
2316
2317 return ret;
2318 }
2319
2320 #ifdef ASSERT
2321 // verify the JavaThread has not yet been published in the Threads::list, and
2322 // hence doesn't need protection from concurrent access at this stage
2323 void JavaThread::verify_not_published() {
2324 if (!Threads_lock->owned_by_self()) {
2325 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2326 assert( !Threads::includes(this),
2327 "java thread shouldn't have been published yet!");
2328 }
2329 else {
2330 assert( !Threads::includes(this),
2331 "java thread shouldn't have been published yet!");
2332 }
2333 }
2334 #endif
2335
2336 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2337 // progress or when _suspend_flags is non-zero.
2338 // Current thread needs to self-suspend if there is a suspend request and/or
2339 // block if a safepoint is in progress.
2340 // Async exception ISN'T checked.
2341 // Note only the ThreadInVMfromNative transition can call this function
2342 // directly and when thread state is _thread_in_native_trans
2343 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2344 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2345
2346 JavaThread *curJT = JavaThread::current();
2347 bool do_self_suspend = thread->is_external_suspend();
2348
2349 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2350
2351 // If JNIEnv proxies are allowed, don't self-suspend if the target
2352 // thread is not the current thread. In older versions of jdbx, jdbx
2353 // threads could call into the VM with another thread's JNIEnv so we
2354 // can be here operating on behalf of a suspended thread (4432884).
2355 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2356 JavaThreadState state = thread->thread_state();
2357
2358 // We mark this thread_blocked state as a suspend-equivalent so
2359 // that a caller to is_ext_suspend_completed() won't be confused.
2360 // The suspend-equivalent state is cleared by java_suspend_self().
2361 thread->set_suspend_equivalent();
2362
2363 // If the safepoint code sees the _thread_in_native_trans state, it will
2364 // wait until the thread changes to other thread state. There is no
2365 // guarantee on how soon we can obtain the SR_lock and complete the
2366 // self-suspend request. It would be a bad idea to let safepoint wait for
2367 // too long. Temporarily change the state to _thread_blocked to
2368 // let the VM thread know that this thread is ready for GC. The problem
2369 // of changing thread state is that safepoint could happen just after
2370 // java_suspend_self() returns after being resumed, and VM thread will
2371 // see the _thread_blocked state. We must check for safepoint
2372 // after restoring the state and make sure we won't leave while a safepoint
2373 // is in progress.
2374 thread->set_thread_state(_thread_blocked);
2375 thread->java_suspend_self();
2376 thread->set_thread_state(state);
2377 // Make sure new state is seen by VM thread
2378 if (os::is_MP()) {
2379 if (UseMembar) {
2380 // Force a fence between the write above and read below
2381 OrderAccess::fence();
2382 } else {
2383 // Must use this rather than serialization page in particular on Windows
2384 InterfaceSupport::serialize_memory(thread);
2385 }
2386 }
2387 }
2388
2389 if (SafepointSynchronize::do_call_back()) {
2390 // If we are safepointing, then block the caller which may not be
2391 // the same as the target thread (see above).
2392 SafepointSynchronize::block(curJT);
2393 }
2394
2395 if (thread->is_deopt_suspend()) {
2396 thread->clear_deopt_suspend();
2397 RegisterMap map(thread, false);
2398 frame f = thread->last_frame();
2399 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2400 f = f.sender(&map);
2401 }
2402 if (f.id() == thread->must_deopt_id()) {
2403 thread->clear_must_deopt_id();
2404 f.deoptimize(thread);
2405 } else {
2406 fatal("missed deoptimization!");
2407 }
2408 }
2409 }
2410
2411 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2412 // progress or when _suspend_flags is non-zero.
2413 // Current thread needs to self-suspend if there is a suspend request and/or
2414 // block if a safepoint is in progress.
2415 // Also check for pending async exception (not including unsafe access error).
2416 // Note only the native==>VM/Java barriers can call this function and when
2417 // thread state is _thread_in_native_trans.
2418 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2419 check_safepoint_and_suspend_for_native_trans(thread);
2420
2421 if (thread->has_async_exception()) {
2422 // We are in _thread_in_native_trans state, don't handle unsafe
2423 // access error since that may block.
2424 thread->check_and_handle_async_exceptions(false);
2425 }
2426 }
2427
2428 // This is a variant of the normal
2429 // check_special_condition_for_native_trans with slightly different
2430 // semantics for use by critical native wrappers. It does all the
2431 // normal checks but also performs the transition back into
2432 // thread_in_Java state. This is required so that critical natives
2433 // can potentially block and perform a GC if they are the last thread
2434 // exiting the GC_locker.
2435 void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) {
2436 check_special_condition_for_native_trans(thread);
2437
2438 // Finish the transition
2439 thread->set_thread_state(_thread_in_Java);
2440
2441 if (thread->do_critical_native_unlock()) {
2442 ThreadInVMfromJavaNoAsyncException tiv(thread);
2443 GC_locker::unlock_critical(thread);
2444 thread->clear_critical_native_unlock();
2445 }
2446 }
2447
2448 // We need to guarantee the Threads_lock here, since resumes are not
2449 // allowed during safepoint synchronization
2450 // Can only resume from an external suspension
2451 void JavaThread::java_resume() {
2452 assert_locked_or_safepoint(Threads_lock);
2453
2454 // Sanity check: thread is gone, has started exiting or the thread
2455 // was not externally suspended.
2456 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2457 return;
2458 }
2459
2460 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2461
2462 clear_external_suspend();
2463
2464 if (is_ext_suspended()) {
2465 clear_ext_suspended();
2466 SR_lock()->notify_all();
2467 }
2468 }
2469
2470 void JavaThread::create_stack_guard_pages() {
2471 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2472 address low_addr = stack_base() - stack_size();
2473 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2474
2475 int allocate = os::allocate_stack_guard_pages();
2476 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2477
2478 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
2479 warning("Attempt to allocate stack guard pages failed.");
2480 return;
2481 }
2482
2483 if (os::guard_memory((char *) low_addr, len)) {
2484 _stack_guard_state = stack_guard_enabled;
2485 } else {
2486 warning("Attempt to protect stack guard pages failed.");
2487 if (os::uncommit_memory((char *) low_addr, len)) {
2488 warning("Attempt to deallocate stack guard pages failed.");
2489 }
2490 }
2491 }
2492
2493 void JavaThread::remove_stack_guard_pages() {
2494 assert(Thread::current() == this, "from different thread");
2495 if (_stack_guard_state == stack_guard_unused) return;
2496 address low_addr = stack_base() - stack_size();
2497 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2498
2499 if (os::allocate_stack_guard_pages()) {
2500 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2501 _stack_guard_state = stack_guard_unused;
2502 } else {
2503 warning("Attempt to deallocate stack guard pages failed.");
2504 }
2505 } else {
2506 if (_stack_guard_state == stack_guard_unused) return;
2507 if (os::unguard_memory((char *) low_addr, len)) {
2508 _stack_guard_state = stack_guard_unused;
2509 } else {
2510 warning("Attempt to unprotect stack guard pages failed.");
2511 }
2512 }
2513 }
2514
2515 void JavaThread::enable_stack_yellow_zone() {
2516 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2517 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2518
2519 // The base notation is from the stacks point of view, growing downward.
2520 // We need to adjust it to work correctly with guard_memory()
2521 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2522
2523 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2524 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2525
2526 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2527 _stack_guard_state = stack_guard_enabled;
2528 } else {
2529 warning("Attempt to guard stack yellow zone failed.");
2530 }
2531 enable_register_stack_guard();
2532 }
2533
2534 void JavaThread::disable_stack_yellow_zone() {
2535 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2536 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2537
2538 // Simply return if called for a thread that does not use guard pages.
2539 if (_stack_guard_state == stack_guard_unused) return;
2540
2541 // The base notation is from the stacks point of view, growing downward.
2542 // We need to adjust it to work correctly with guard_memory()
2543 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2544
2545 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2546 _stack_guard_state = stack_guard_yellow_disabled;
2547 } else {
2548 warning("Attempt to unguard stack yellow zone failed.");
2549 }
2550 disable_register_stack_guard();
2551 }
2552
2553 void JavaThread::enable_stack_red_zone() {
2554 // The base notation is from the stacks point of view, growing downward.
2555 // We need to adjust it to work correctly with guard_memory()
2556 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2557 address base = stack_red_zone_base() - stack_red_zone_size();
2558
2559 guarantee(base < stack_base(),"Error calculating stack red zone");
2560 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2561
2562 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2563 warning("Attempt to guard stack red zone failed.");
2564 }
2565 }
2566
2567 void JavaThread::disable_stack_red_zone() {
2568 // The base notation is from the stacks point of view, growing downward.
2569 // We need to adjust it to work correctly with guard_memory()
2570 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2571 address base = stack_red_zone_base() - stack_red_zone_size();
2572 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2573 warning("Attempt to unguard stack red zone failed.");
2574 }
2575 }
2576
2577 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2578 // ignore is there is no stack
2579 if (!has_last_Java_frame()) return;
2580 // traverse the stack frames. Starts from top frame.
2581 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2582 frame* fr = fst.current();
2583 f(fr, fst.register_map());
2584 }
2585 }
2586
2587
2588 #ifndef PRODUCT
2589 // Deoptimization
2590 // Function for testing deoptimization
2591 void JavaThread::deoptimize() {
2592 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2593 StackFrameStream fst(this, UseBiasedLocking);
2594 bool deopt = false; // Dump stack only if a deopt actually happens.
2595 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2596 // Iterate over all frames in the thread and deoptimize
2597 for(; !fst.is_done(); fst.next()) {
2598 if(fst.current()->can_be_deoptimized()) {
2599
2600 if (only_at) {
2601 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2602 // consists of comma or carriage return separated numbers so
2603 // search for the current bci in that string.
2604 address pc = fst.current()->pc();
2605 nmethod* nm = (nmethod*) fst.current()->cb();
2606 ScopeDesc* sd = nm->scope_desc_at( pc);
2607 char buffer[8];
2608 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2609 size_t len = strlen(buffer);
2610 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2611 while (found != NULL) {
2612 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2613 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2614 // Check that the bci found is bracketed by terminators.
2615 break;
2616 }
2617 found = strstr(found + 1, buffer);
2618 }
2619 if (!found) {
2620 continue;
2621 }
2622 }
2623
2624 if (DebugDeoptimization && !deopt) {
2625 deopt = true; // One-time only print before deopt
2626 tty->print_cr("[BEFORE Deoptimization]");
2627 trace_frames();
2628 trace_stack();
2629 }
2630 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2631 }
2632 }
2633
2634 if (DebugDeoptimization && deopt) {
2635 tty->print_cr("[AFTER Deoptimization]");
2636 trace_frames();
2637 }
2638 }
2639
2640
2641 // Make zombies
2642 void JavaThread::make_zombies() {
2643 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2644 if (fst.current()->can_be_deoptimized()) {
2645 // it is a Java nmethod
2646 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2647 nm->make_not_entrant();
2648 }
2649 }
2650 }
2651 #endif // PRODUCT
2652
2653
2654 void JavaThread::deoptimized_wrt_marked_nmethods() {
2655 if (!has_last_Java_frame()) return;
2656 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2657 StackFrameStream fst(this, UseBiasedLocking);
2658 for(; !fst.is_done(); fst.next()) {
2659 if (fst.current()->should_be_deoptimized()) {
2660 if (LogCompilation && xtty != NULL) {
2661 nmethod* nm = fst.current()->cb()->as_nmethod_or_null();
2662 xtty->elem("deoptimized thread='" UINTX_FORMAT "' compile_id='%d'",
2663 this->name(), nm != NULL ? nm->compile_id() : -1);
2664 }
2665
2666 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2667 }
2668 }
2669 }
2670
2671
2672 // GC support
2673 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2674
2675 void JavaThread::gc_epilogue() {
2676 frames_do(frame_gc_epilogue);
2677 }
2678
2679
2680 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2681
2682 void JavaThread::gc_prologue() {
2683 frames_do(frame_gc_prologue);
2684 }
2685
2686 // If the caller is a NamedThread, then remember, in the current scope,
2687 // the given JavaThread in its _processed_thread field.
2688 class RememberProcessedThread: public StackObj {
2689 NamedThread* _cur_thr;
2690 public:
2691 RememberProcessedThread(JavaThread* jthr) {
2692 Thread* thread = Thread::current();
2693 if (thread->is_Named_thread()) {
2694 _cur_thr = (NamedThread *)thread;
2695 _cur_thr->set_processed_thread(jthr);
2696 } else {
2697 _cur_thr = NULL;
2698 }
2699 }
2700
2701 ~RememberProcessedThread() {
2702 if (_cur_thr) {
2703 _cur_thr->set_processed_thread(NULL);
2704 }
2705 }
2706 };
2707
2708 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2709 // Verify that the deferred card marks have been flushed.
2710 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2711
2712 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2713 // since there may be more than one thread using each ThreadProfiler.
2714
2715 // Traverse the GCHandles
2716 Thread::oops_do(f, cf);
2717
2718 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2719 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2720
2721 if (has_last_Java_frame()) {
2722 // Record JavaThread to GC thread
2723 RememberProcessedThread rpt(this);
2724
2725 // Traverse the privileged stack
2726 if (_privileged_stack_top != NULL) {
2727 _privileged_stack_top->oops_do(f);
2728 }
2729
2730 // traverse the registered growable array
2731 if (_array_for_gc != NULL) {
2732 for (int index = 0; index < _array_for_gc->length(); index++) {
2733 f->do_oop(_array_for_gc->adr_at(index));
2734 }
2735 }
2736
2737 // Traverse the monitor chunks
2738 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2739 chunk->oops_do(f);
2740 }
2741
2742 // Traverse the execution stack
2743 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2744 fst.current()->oops_do(f, cf, fst.register_map());
2745 }
2746 }
2747
2748 // callee_target is never live across a gc point so NULL it here should
2749 // it still contain a methdOop.
2750
2751 set_callee_target(NULL);
2752
2753 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2754 // If we have deferred set_locals there might be oops waiting to be
2755 // written
2756 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2757 if (list != NULL) {
2758 for (int i = 0; i < list->length(); i++) {
2759 list->at(i)->oops_do(f);
2760 }
2761 }
2762
2763 // Traverse instance variables at the end since the GC may be moving things
2764 // around using this function
2765 f->do_oop((oop*) &_threadObj);
2766 f->do_oop((oop*) &_vm_result);
2767 f->do_oop((oop*) &_exception_oop);
2768 f->do_oop((oop*) &_pending_async_exception);
2769
2770 if (jvmti_thread_state() != NULL) {
2771 jvmti_thread_state()->oops_do(f);
2772 }
2773 }
2774
2775 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2776 Thread::nmethods_do(cf); // (super method is a no-op)
2777
2778 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2779 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2780
2781 if (has_last_Java_frame()) {
2782 // Traverse the execution stack
2783 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2784 fst.current()->nmethods_do(cf);
2785 }
2786 }
2787 }
2788
2789 void JavaThread::metadata_do(void f(Metadata*)) {
2790 Thread::metadata_do(f);
2791 if (has_last_Java_frame()) {
2792 // Traverse the execution stack to call f() on the methods in the stack
2793 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2794 fst.current()->metadata_do(f);
2795 }
2796 } else if (is_Compiler_thread()) {
2797 // need to walk ciMetadata in current compile tasks to keep alive.
2798 CompilerThread* ct = (CompilerThread*)this;
2799 if (ct->env() != NULL) {
2800 ct->env()->metadata_do(f);
2801 }
2802 }
2803 }
2804
2805 // Printing
2806 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2807 switch (_thread_state) {
2808 case _thread_uninitialized: return "_thread_uninitialized";
2809 case _thread_new: return "_thread_new";
2810 case _thread_new_trans: return "_thread_new_trans";
2811 case _thread_in_native: return "_thread_in_native";
2812 case _thread_in_native_trans: return "_thread_in_native_trans";
2813 case _thread_in_vm: return "_thread_in_vm";
2814 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2815 case _thread_in_Java: return "_thread_in_Java";
2816 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2817 case _thread_blocked: return "_thread_blocked";
2818 case _thread_blocked_trans: return "_thread_blocked_trans";
2819 default: return "unknown thread state";
2820 }
2821 }
2822
2823 #ifndef PRODUCT
2824 void JavaThread::print_thread_state_on(outputStream *st) const {
2825 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2826 };
2827 void JavaThread::print_thread_state() const {
2828 print_thread_state_on(tty);
2829 };
2830 #endif // PRODUCT
2831
2832 // Called by Threads::print() for VM_PrintThreads operation
2833 void JavaThread::print_on(outputStream *st) const {
2834 st->print("\"%s\" ", get_thread_name());
2835 oop thread_oop = threadObj();
2836 if (thread_oop != NULL) {
2837 st->print("#" INT64_FORMAT " ", java_lang_Thread::thread_id(thread_oop));
2838 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2839 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2840 }
2841 Thread::print_on(st);
2842 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2843 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2844 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2845 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2846 }
2847 #ifndef PRODUCT
2848 print_thread_state_on(st);
2849 _safepoint_state->print_on(st);
2850 #endif // PRODUCT
2851 }
2852
2853 // Called by fatal error handler. The difference between this and
2854 // JavaThread::print() is that we can't grab lock or allocate memory.
2855 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2856 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2857 oop thread_obj = threadObj();
2858 if (thread_obj != NULL) {
2859 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2860 }
2861 st->print(" [");
2862 st->print("%s", _get_thread_state_name(_thread_state));
2863 if (osthread()) {
2864 st->print(", id=%d", osthread()->thread_id());
2865 }
2866 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2867 _stack_base - _stack_size, _stack_base);
2868 st->print("]");
2869 return;
2870 }
2871
2872 // Verification
2873
2874 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2875
2876 void JavaThread::verify() {
2877 // Verify oops in the thread.
2878 oops_do(&VerifyOopClosure::verify_oop, NULL);
2879
2880 // Verify the stack frames.
2881 frames_do(frame_verify);
2882 }
2883
2884 // CR 6300358 (sub-CR 2137150)
2885 // Most callers of this method assume that it can't return NULL but a
2886 // thread may not have a name whilst it is in the process of attaching to
2887 // the VM - see CR 6412693, and there are places where a JavaThread can be
2888 // seen prior to having it's threadObj set (eg JNI attaching threads and
2889 // if vm exit occurs during initialization). These cases can all be accounted
2890 // for such that this method never returns NULL.
2891 const char* JavaThread::get_thread_name() const {
2892 #ifdef ASSERT
2893 // early safepoints can hit while current thread does not yet have TLS
2894 if (!SafepointSynchronize::is_at_safepoint()) {
2895 Thread *cur = Thread::current();
2896 if (!(cur->is_Java_thread() && cur == this)) {
2897 // Current JavaThreads are allowed to get their own name without
2898 // the Threads_lock.
2899 assert_locked_or_safepoint(Threads_lock);
2900 }
2901 }
2902 #endif // ASSERT
2903 return get_thread_name_string();
2904 }
2905
2906 // Returns a non-NULL representation of this thread's name, or a suitable
2907 // descriptive string if there is no set name
2908 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2909 const char* name_str;
2910 oop thread_obj = threadObj();
2911 if (thread_obj != NULL) {
2912 typeArrayOop name = java_lang_Thread::name(thread_obj);
2913 if (name != NULL) {
2914 if (buf == NULL) {
2915 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2916 }
2917 else {
2918 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2919 }
2920 }
2921 else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2922 name_str = "<no-name - thread is attaching>";
2923 }
2924 else {
2925 name_str = Thread::name();
2926 }
2927 }
2928 else {
2929 name_str = Thread::name();
2930 }
2931 assert(name_str != NULL, "unexpected NULL thread name");
2932 return name_str;
2933 }
2934
2935
2936 const char* JavaThread::get_threadgroup_name() const {
2937 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2938 oop thread_obj = threadObj();
2939 if (thread_obj != NULL) {
2940 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2941 if (thread_group != NULL) {
2942 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2943 // ThreadGroup.name can be null
2944 if (name != NULL) {
2945 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2946 return str;
2947 }
2948 }
2949 }
2950 return NULL;
2951 }
2952
2953 const char* JavaThread::get_parent_name() const {
2954 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2955 oop thread_obj = threadObj();
2956 if (thread_obj != NULL) {
2957 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2958 if (thread_group != NULL) {
2959 oop parent = java_lang_ThreadGroup::parent(thread_group);
2960 if (parent != NULL) {
2961 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2962 // ThreadGroup.name can be null
2963 if (name != NULL) {
2964 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2965 return str;
2966 }
2967 }
2968 }
2969 }
2970 return NULL;
2971 }
2972
2973 ThreadPriority JavaThread::java_priority() const {
2974 oop thr_oop = threadObj();
2975 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2976 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2977 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2978 return priority;
2979 }
2980
2981 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2982
2983 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2984 // Link Java Thread object <-> C++ Thread
2985
2986 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2987 // and put it into a new Handle. The Handle "thread_oop" can then
2988 // be used to pass the C++ thread object to other methods.
2989
2990 // Set the Java level thread object (jthread) field of the
2991 // new thread (a JavaThread *) to C++ thread object using the
2992 // "thread_oop" handle.
2993
2994 // Set the thread field (a JavaThread *) of the
2995 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2996
2997 Handle thread_oop(Thread::current(),
2998 JNIHandles::resolve_non_null(jni_thread));
2999 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
3000 "must be initialized");
3001 set_threadObj(thread_oop());
3002 java_lang_Thread::set_thread(thread_oop(), this);
3003
3004 if (prio == NoPriority) {
3005 prio = java_lang_Thread::priority(thread_oop());
3006 assert(prio != NoPriority, "A valid priority should be present");
3007 }
3008
3009 // Push the Java priority down to the native thread; needs Threads_lock
3010 Thread::set_priority(this, prio);
3011
3012 // Add the new thread to the Threads list and set it in motion.
3013 // We must have threads lock in order to call Threads::add.
3014 // It is crucial that we do not block before the thread is
3015 // added to the Threads list for if a GC happens, then the java_thread oop
3016 // will not be visited by GC.
3017 Threads::add(this);
3018 }
3019
3020 oop JavaThread::current_park_blocker() {
3021 // Support for JSR-166 locks
3022 oop thread_oop = threadObj();
3023 if (thread_oop != NULL &&
3024 JDK_Version::current().supports_thread_park_blocker()) {
3025 return java_lang_Thread::park_blocker(thread_oop);
3026 }
3027 return NULL;
3028 }
3029
3030
3031 void JavaThread::print_stack_on(outputStream* st) {
3032 if (!has_last_Java_frame()) return;
3033 ResourceMark rm;
3034 HandleMark hm;
3035
3036 RegisterMap reg_map(this);
3037 vframe* start_vf = last_java_vframe(®_map);
3038 int count = 0;
3039 for (vframe* f = start_vf; f; f = f->sender() ) {
3040 if (f->is_java_frame()) {
3041 javaVFrame* jvf = javaVFrame::cast(f);
3042 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
3043
3044 // Print out lock information
3045 if (JavaMonitorsInStackTrace) {
3046 jvf->print_lock_info_on(st, count);
3047 }
3048 } else {
3049 // Ignore non-Java frames
3050 }
3051
3052 // Bail-out case for too deep stacks
3053 count++;
3054 if (MaxJavaStackTraceDepth == count) return;
3055 }
3056 }
3057
3058
3059 // JVMTI PopFrame support
3060 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
3061 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
3062 if (in_bytes(size_in_bytes) != 0) {
3063 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
3064 _popframe_preserved_args_size = in_bytes(size_in_bytes);
3065 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
3066 }
3067 }
3068
3069 void* JavaThread::popframe_preserved_args() {
3070 return _popframe_preserved_args;
3071 }
3072
3073 ByteSize JavaThread::popframe_preserved_args_size() {
3074 return in_ByteSize(_popframe_preserved_args_size);
3075 }
3076
3077 WordSize JavaThread::popframe_preserved_args_size_in_words() {
3078 int sz = in_bytes(popframe_preserved_args_size());
3079 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
3080 return in_WordSize(sz / wordSize);
3081 }
3082
3083 void JavaThread::popframe_free_preserved_args() {
3084 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
3085 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args, mtThread);
3086 _popframe_preserved_args = NULL;
3087 _popframe_preserved_args_size = 0;
3088 }
3089
3090 #ifndef PRODUCT
3091
3092 void JavaThread::trace_frames() {
3093 tty->print_cr("[Describe stack]");
3094 int frame_no = 1;
3095 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
3096 tty->print(" %d. ", frame_no++);
3097 fst.current()->print_value_on(tty,this);
3098 tty->cr();
3099 }
3100 }
3101
3102 class PrintAndVerifyOopClosure: public OopClosure {
3103 protected:
3104 template <class T> inline void do_oop_work(T* p) {
3105 oop obj = oopDesc::load_decode_heap_oop(p);
3106 if (obj == NULL) return;
3107 tty->print(INTPTR_FORMAT ": ", p);
3108 if (obj->is_oop_or_null()) {
3109 if (obj->is_objArray()) {
3110 tty->print_cr("valid objArray: " INTPTR_FORMAT, (oopDesc*) obj);
3111 } else {
3112 obj->print();
3113 }
3114 } else {
3115 tty->print_cr("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj);
3116 }
3117 tty->cr();
3118 }
3119 public:
3120 virtual void do_oop(oop* p) { do_oop_work(p); }
3121 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
3122 };
3123
3124
3125 static void oops_print(frame* f, const RegisterMap *map) {
3126 PrintAndVerifyOopClosure print;
3127 f->print_value();
3128 f->oops_do(&print, NULL, (RegisterMap*)map);
3129 }
3130
3131 // Print our all the locations that contain oops and whether they are
3132 // valid or not. This useful when trying to find the oldest frame
3133 // where an oop has gone bad since the frame walk is from youngest to
3134 // oldest.
3135 void JavaThread::trace_oops() {
3136 tty->print_cr("[Trace oops]");
3137 frames_do(oops_print);
3138 }
3139
3140
3141 #ifdef ASSERT
3142 // Print or validate the layout of stack frames
3143 void JavaThread::print_frame_layout(int depth, bool validate_only) {
3144 ResourceMark rm;
3145 PRESERVE_EXCEPTION_MARK;
3146 FrameValues values;
3147 int frame_no = 0;
3148 for(StackFrameStream fst(this, false); !fst.is_done(); fst.next()) {
3149 fst.current()->describe(values, ++frame_no);
3150 if (depth == frame_no) break;
3151 }
3152 if (validate_only) {
3153 values.validate();
3154 } else {
3155 tty->print_cr("[Describe stack layout]");
3156 values.print(this);
3157 }
3158 }
3159 #endif
3160
3161 void JavaThread::trace_stack_from(vframe* start_vf) {
3162 ResourceMark rm;
3163 int vframe_no = 1;
3164 for (vframe* f = start_vf; f; f = f->sender() ) {
3165 if (f->is_java_frame()) {
3166 javaVFrame::cast(f)->print_activation(vframe_no++);
3167 } else {
3168 f->print();
3169 }
3170 if (vframe_no > StackPrintLimit) {
3171 tty->print_cr("...<more frames>...");
3172 return;
3173 }
3174 }
3175 }
3176
3177
3178 void JavaThread::trace_stack() {
3179 if (!has_last_Java_frame()) return;
3180 ResourceMark rm;
3181 HandleMark hm;
3182 RegisterMap reg_map(this);
3183 trace_stack_from(last_java_vframe(®_map));
3184 }
3185
3186
3187 #endif // PRODUCT
3188
3189
3190 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
3191 assert(reg_map != NULL, "a map must be given");
3192 frame f = last_frame();
3193 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
3194 if (vf->is_java_frame()) return javaVFrame::cast(vf);
3195 }
3196 return NULL;
3197 }
3198
3199
3200 Klass* JavaThread::security_get_caller_class(int depth) {
3201 vframeStream vfst(this);
3202 vfst.security_get_caller_frame(depth);
3203 if (!vfst.at_end()) {
3204 return vfst.method()->method_holder();
3205 }
3206 return NULL;
3207 }
3208
3209 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
3210 assert(thread->is_Compiler_thread(), "must be compiler thread");
3211 CompileBroker::compiler_thread_loop();
3212 }
3213
3214 // Create a CompilerThread
3215 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
3216 : JavaThread(&compiler_thread_entry) {
3217 _env = NULL;
3218 _log = NULL;
3219 _task = NULL;
3220 _queue = queue;
3221 _counters = counters;
3222 _buffer_blob = NULL;
3223 _scanned_nmethod = NULL;
3224
3225 #ifndef PRODUCT
3226 _ideal_graph_printer = NULL;
3227 #endif
3228 }
3229
3230 void CompilerThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3231 JavaThread::oops_do(f, cf);
3232 if (_scanned_nmethod != NULL && cf != NULL) {
3233 // Safepoints can occur when the sweeper is scanning an nmethod so
3234 // process it here to make sure it isn't unloaded in the middle of
3235 // a scan.
3236 cf->do_code_blob(_scanned_nmethod);
3237 }
3238 }
3239
3240 // ======= Threads ========
3241
3242 // The Threads class links together all active threads, and provides
3243 // operations over all threads. It is protected by its own Mutex
3244 // lock, which is also used in other contexts to protect thread
3245 // operations from having the thread being operated on from exiting
3246 // and going away unexpectedly (e.g., safepoint synchronization)
3247
3248 JavaThread* Threads::_thread_list = NULL;
3249 int Threads::_number_of_threads = 0;
3250 int Threads::_number_of_non_daemon_threads = 0;
3251 int Threads::_return_code = 0;
3252 size_t JavaThread::_stack_size_at_create = 0;
3253 #ifdef ASSERT
3254 bool Threads::_vm_complete = false;
3255 #endif
3256
3257 // All JavaThreads
3258 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
3259
3260 void os_stream();
3261
3262 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
3263 void Threads::threads_do(ThreadClosure* tc) {
3264 assert_locked_or_safepoint(Threads_lock);
3265 // ALL_JAVA_THREADS iterates through all JavaThreads
3266 ALL_JAVA_THREADS(p) {
3267 tc->do_thread(p);
3268 }
3269 // Someday we could have a table or list of all non-JavaThreads.
3270 // For now, just manually iterate through them.
3271 tc->do_thread(VMThread::vm_thread());
3272 Universe::heap()->gc_threads_do(tc);
3273 WatcherThread *wt = WatcherThread::watcher_thread();
3274 // Strictly speaking, the following NULL check isn't sufficient to make sure
3275 // the data for WatcherThread is still valid upon being examined. However,
3276 // considering that WatchThread terminates when the VM is on the way to
3277 // exit at safepoint, the chance of the above is extremely small. The right
3278 // way to prevent termination of WatcherThread would be to acquire
3279 // Terminator_lock, but we can't do that without violating the lock rank
3280 // checking in some cases.
3281 if (wt != NULL)
3282 tc->do_thread(wt);
3283
3284 // If CompilerThreads ever become non-JavaThreads, add them here
3285 }
3286
3287 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
3288
3289 extern void JDK_Version_init();
3290
3291 // Check version
3292 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
3293
3294 // Initialize the output stream module
3295 ostream_init();
3296
3297 // Process java launcher properties.
3298 Arguments::process_sun_java_launcher_properties(args);
3299
3300 // Initialize the os module before using TLS
3301 os::init();
3302
3303 // Initialize system properties.
3304 Arguments::init_system_properties();
3305
3306 // So that JDK version can be used as a discrimintor when parsing arguments
3307 JDK_Version_init();
3308
3309 // Update/Initialize System properties after JDK version number is known
3310 Arguments::init_version_specific_system_properties();
3311
3312 // Parse arguments
3313 jint parse_result = Arguments::parse(args);
3314 if (parse_result != JNI_OK) return parse_result;
3315
3316 if (PauseAtStartup) {
3317 os::pause();
3318 }
3319
3320 #ifndef USDT2
3321 HS_DTRACE_PROBE(hotspot, vm__init__begin);
3322 #else /* USDT2 */
3323 HOTSPOT_VM_INIT_BEGIN();
3324 #endif /* USDT2 */
3325
3326 // Record VM creation timing statistics
3327 TraceVmCreationTime create_vm_timer;
3328 create_vm_timer.start();
3329
3330 // Timing (must come after argument parsing)
3331 TraceTime timer("Create VM", TraceStartupTime);
3332
3333 // Initialize the os module after parsing the args
3334 jint os_init_2_result = os::init_2();
3335 if (os_init_2_result != JNI_OK) return os_init_2_result;
3336
3337 // intialize TLS
3338 ThreadLocalStorage::init();
3339
3340 // Bootstrap native memory tracking, so it can start recording memory
3341 // activities before worker thread is started. This is the first phase
3342 // of bootstrapping, VM is currently running in single-thread mode.
3343 MemTracker::bootstrap_single_thread();
3344
3345 // Initialize output stream logging
3346 ostream_init_log();
3347
3348 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
3349 // Must be before create_vm_init_agents()
3350 if (Arguments::init_libraries_at_startup()) {
3351 convert_vm_init_libraries_to_agents();
3352 }
3353
3354 // Launch -agentlib/-agentpath and converted -Xrun agents
3355 if (Arguments::init_agents_at_startup()) {
3356 create_vm_init_agents();
3357 }
3358
3359 // Initialize Threads state
3360 _thread_list = NULL;
3361 _number_of_threads = 0;
3362 _number_of_non_daemon_threads = 0;
3363
3364 // Initialize global data structures and create system classes in heap
3365 vm_init_globals();
3366
3367 // Attach the main thread to this os thread
3368 JavaThread* main_thread = new JavaThread();
3369 main_thread->set_thread_state(_thread_in_vm);
3370 // must do this before set_active_handles and initialize_thread_local_storage
3371 // Note: on solaris initialize_thread_local_storage() will (indirectly)
3372 // change the stack size recorded here to one based on the java thread
3373 // stacksize. This adjusted size is what is used to figure the placement
3374 // of the guard pages.
3375 main_thread->record_stack_base_and_size();
3376 main_thread->initialize_thread_local_storage();
3377
3378 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
3379
3380 if (!main_thread->set_as_starting_thread()) {
3381 vm_shutdown_during_initialization(
3382 "Failed necessary internal allocation. Out of swap space");
3383 delete main_thread;
3384 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3385 return JNI_ENOMEM;
3386 }
3387
3388 // Enable guard page *after* os::create_main_thread(), otherwise it would
3389 // crash Linux VM, see notes in os_linux.cpp.
3390 main_thread->create_stack_guard_pages();
3391
3392 // Initialize Java-Level synchronization subsystem
3393 ObjectMonitor::Initialize() ;
3394
3395 // Second phase of bootstrapping, VM is about entering multi-thread mode
3396 MemTracker::bootstrap_multi_thread();
3397
3398 // Initialize global modules
3399 jint status = init_globals();
3400 if (status != JNI_OK) {
3401 delete main_thread;
3402 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3403 return status;
3404 }
3405
3406 // Should be done after the heap is fully created
3407 main_thread->cache_global_variables();
3408
3409 HandleMark hm;
3410
3411 { MutexLocker mu(Threads_lock);
3412 Threads::add(main_thread);
3413 }
3414
3415 // Any JVMTI raw monitors entered in onload will transition into
3416 // real raw monitor. VM is setup enough here for raw monitor enter.
3417 JvmtiExport::transition_pending_onload_raw_monitors();
3418
3419 if (VerifyBeforeGC &&
3420 Universe::heap()->total_collections() >= VerifyGCStartAt) {
3421 Universe::heap()->prepare_for_verify();
3422 Universe::verify(); // make sure we're starting with a clean slate
3423 }
3424
3425 // Fully start NMT
3426 MemTracker::start();
3427
3428 // Create the VMThread
3429 { TraceTime timer("Start VMThread", TraceStartupTime);
3430 VMThread::create();
3431 Thread* vmthread = VMThread::vm_thread();
3432
3433 if (!os::create_thread(vmthread, os::vm_thread))
3434 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
3435
3436 // Wait for the VM thread to become ready, and VMThread::run to initialize
3437 // Monitors can have spurious returns, must always check another state flag
3438 {
3439 MutexLocker ml(Notify_lock);
3440 os::start_thread(vmthread);
3441 while (vmthread->active_handles() == NULL) {
3442 Notify_lock->wait();
3443 }
3444 }
3445 }
3446
3447 assert (Universe::is_fully_initialized(), "not initialized");
3448 EXCEPTION_MARK;
3449
3450 // At this point, the Universe is initialized, but we have not executed
3451 // any byte code. Now is a good time (the only time) to dump out the
3452 // internal state of the JVM for sharing.
3453 if (DumpSharedSpaces) {
3454 MetaspaceShared::preload_and_dump(CHECK_0);
3455 ShouldNotReachHere();
3456 }
3457
3458 // Always call even when there are not JVMTI environments yet, since environments
3459 // may be attached late and JVMTI must track phases of VM execution
3460 JvmtiExport::enter_start_phase();
3461
3462 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3463 JvmtiExport::post_vm_start();
3464
3465 {
3466 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3467
3468 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3469 create_vm_init_libraries();
3470 }
3471
3472 if (InitializeJavaLangString) {
3473 initialize_class(vmSymbols::java_lang_String(), CHECK_0);
3474 } else {
3475 warning("java.lang.String not initialized");
3476 }
3477
3478 if (AggressiveOpts) {
3479 {
3480 // Forcibly initialize java/util/HashMap and mutate the private
3481 // static final "frontCacheEnabled" field before we start creating instances
3482 #ifdef ASSERT
3483 Klass* tmp_k = SystemDictionary::find(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3484 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
3485 #endif
3486 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3487 KlassHandle k = KlassHandle(THREAD, k_o);
3488 guarantee(k.not_null(), "Must find java/util/HashMap");
3489 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3490 ik->initialize(CHECK_0);
3491 fieldDescriptor fd;
3492 // Possible we might not find this field; if so, don't break
3493 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3494 k()->java_mirror()->bool_field_put(fd.offset(), true);
3495 }
3496 }
3497
3498 if (UseStringCache) {
3499 // Forcibly initialize java/lang/StringValue and mutate the private
3500 // static final "stringCacheEnabled" field before we start creating instances
3501 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3502 // Possible that StringValue isn't present: if so, silently don't break
3503 if (k_o != NULL) {
3504 KlassHandle k = KlassHandle(THREAD, k_o);
3505 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3506 ik->initialize(CHECK_0);
3507 fieldDescriptor fd;
3508 // Possible we might not find this field: if so, silently don't break
3509 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3510 k()->java_mirror()->bool_field_put(fd.offset(), true);
3511 }
3512 }
3513 }
3514 }
3515
3516 // Initialize java_lang.System (needed before creating the thread)
3517 if (InitializeJavaLangSystem) {
3518 initialize_class(vmSymbols::java_lang_System(), CHECK_0);
3519 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK_0);
3520 Handle thread_group = create_initial_thread_group(CHECK_0);
3521 Universe::set_main_thread_group(thread_group());
3522 initialize_class(vmSymbols::java_lang_Thread(), CHECK_0);
3523 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3524 main_thread->set_threadObj(thread_object);
3525 // Set thread status to running since main thread has
3526 // been started and running.
3527 java_lang_Thread::set_thread_status(thread_object,
3528 java_lang_Thread::RUNNABLE);
3529
3530 // The VM preresolve methods to these classes. Make sure that get initialized
3531 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK_0);
3532 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK_0);
3533 // The VM creates & returns objects of this class. Make sure it's initialized.
3534 initialize_class(vmSymbols::java_lang_Class(), CHECK_0);
3535 call_initializeSystemClass(CHECK_0);
3536
3537 // get the Java runtime name after java.lang.System is initialized
3538 JDK_Version::set_runtime_name(get_java_runtime_name(THREAD));
3539 JDK_Version::set_runtime_version(get_java_runtime_version(THREAD));
3540 } else {
3541 warning("java.lang.System not initialized");
3542 }
3543
3544 // an instance of OutOfMemory exception has been allocated earlier
3545 if (InitializeJavaLangExceptionsErrors) {
3546 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK_0);
3547 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK_0);
3548 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK_0);
3549 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK_0);
3550 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK_0);
3551 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK_0);
3552 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK_0);
3553 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK_0);
3554 } else {
3555 warning("java.lang.OutOfMemoryError has not been initialized");
3556 warning("java.lang.NullPointerException has not been initialized");
3557 warning("java.lang.ClassCastException has not been initialized");
3558 warning("java.lang.ArrayStoreException has not been initialized");
3559 warning("java.lang.ArithmeticException has not been initialized");
3560 warning("java.lang.StackOverflowError has not been initialized");
3561 warning("java.lang.IllegalArgumentException has not been initialized");
3562 }
3563 }
3564
3565 // See : bugid 4211085.
3566 // Background : the static initializer of java.lang.Compiler tries to read
3567 // property"java.compiler" and read & write property "java.vm.info".
3568 // When a security manager is installed through the command line
3569 // option "-Djava.security.manager", the above properties are not
3570 // readable and the static initializer for java.lang.Compiler fails
3571 // resulting in a NoClassDefFoundError. This can happen in any
3572 // user code which calls methods in java.lang.Compiler.
3573 // Hack : the hack is to pre-load and initialize this class, so that only
3574 // system domains are on the stack when the properties are read.
3575 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3576 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3577 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3578 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3579 // Once that is done, we should remove this hack.
3580 initialize_class(vmSymbols::java_lang_Compiler(), CHECK_0);
3581
3582 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3583 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3584 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3585 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3586 // This should also be taken out as soon as 4211383 gets fixed.
3587 reset_vm_info_property(CHECK_0);
3588
3589 quicken_jni_functions();
3590
3591 // Must be run after init_ft which initializes ft_enabled
3592 if (TRACE_INITIALIZE() != JNI_OK) {
3593 vm_exit_during_initialization("Failed to initialize tracing backend");
3594 }
3595
3596 // Set flag that basic initialization has completed. Used by exceptions and various
3597 // debug stuff, that does not work until all basic classes have been initialized.
3598 set_init_completed();
3599
3600 #ifndef USDT2
3601 HS_DTRACE_PROBE(hotspot, vm__init__end);
3602 #else /* USDT2 */
3603 HOTSPOT_VM_INIT_END();
3604 #endif /* USDT2 */
3605
3606 // record VM initialization completion time
3607 #if INCLUDE_MANAGEMENT
3608 Management::record_vm_init_completed();
3609 #endif // INCLUDE_MANAGEMENT
3610
3611 // Compute system loader. Note that this has to occur after set_init_completed, since
3612 // valid exceptions may be thrown in the process.
3613 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3614 // set_init_completed has just been called, causing exceptions not to be shortcut
3615 // anymore. We call vm_exit_during_initialization directly instead.
3616 SystemDictionary::compute_java_system_loader(THREAD);
3617 if (HAS_PENDING_EXCEPTION) {
3618 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3619 }
3620
3621 #ifndef SERIALGC
3622 // Support for ConcurrentMarkSweep. This should be cleaned up
3623 // and better encapsulated. The ugly nested if test would go away
3624 // once things are properly refactored. XXX YSR
3625 if (UseConcMarkSweepGC || UseG1GC) {
3626 if (UseConcMarkSweepGC) {
3627 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3628 } else {
3629 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3630 }
3631 if (HAS_PENDING_EXCEPTION) {
3632 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3633 }
3634 }
3635 #endif // SERIALGC
3636
3637 // Always call even when there are not JVMTI environments yet, since environments
3638 // may be attached late and JVMTI must track phases of VM execution
3639 JvmtiExport::enter_live_phase();
3640
3641 // Signal Dispatcher needs to be started before VMInit event is posted
3642 os::signal_init();
3643
3644 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3645 if (!DisableAttachMechanism) {
3646 if (StartAttachListener || AttachListener::init_at_startup()) {
3647 AttachListener::init();
3648 }
3649 }
3650
3651 // Launch -Xrun agents
3652 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3653 // back-end can launch with -Xdebug -Xrunjdwp.
3654 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3655 create_vm_init_libraries();
3656 }
3657
3658 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3659 JvmtiExport::post_vm_initialized();
3660
3661 if (!TRACE_START()) {
3662 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3663 }
3664
3665 if (CleanChunkPoolAsync) {
3666 Chunk::start_chunk_pool_cleaner_task();
3667 }
3668
3669 // initialize compiler(s)
3670 #if defined(COMPILER1) || defined(COMPILER2) || defined(SHARK)
3671 CompileBroker::compilation_init();
3672 #endif
3673
3674 #if INCLUDE_MANAGEMENT
3675 Management::initialize(THREAD);
3676 #endif // INCLUDE_MANAGEMENT
3677
3678 if (HAS_PENDING_EXCEPTION) {
3679 // management agent fails to start possibly due to
3680 // configuration problem and is responsible for printing
3681 // stack trace if appropriate. Simply exit VM.
3682 vm_exit(1);
3683 }
3684
3685 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3686 if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
3687 if (MemProfiling) MemProfiler::engage();
3688 StatSampler::engage();
3689 if (CheckJNICalls) JniPeriodicChecker::engage();
3690
3691 BiasedLocking::init();
3692
3693 if (JDK_Version::current().post_vm_init_hook_enabled()) {
3694 call_postVMInitHook(THREAD);
3695 // The Java side of PostVMInitHook.run must deal with all
3696 // exceptions and provide means of diagnosis.
3697 if (HAS_PENDING_EXCEPTION) {
3698 CLEAR_PENDING_EXCEPTION;
3699 }
3700 }
3701
3702 {
3703 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
3704 // Make sure the watcher thread can be started by WatcherThread::start()
3705 // or by dynamic enrollment.
3706 WatcherThread::make_startable();
3707 // Start up the WatcherThread if there are any periodic tasks
3708 // NOTE: All PeriodicTasks should be registered by now. If they
3709 // aren't, late joiners might appear to start slowly (we might
3710 // take a while to process their first tick).
3711 if (PeriodicTask::num_tasks() > 0) {
3712 WatcherThread::start();
3713 }
3714 }
3715
3716 // Give os specific code one last chance to start
3717 os::init_3();
3718
3719 create_vm_timer.end();
3720 #ifdef ASSERT
3721 _vm_complete = true;
3722 #endif
3723 return JNI_OK;
3724 }
3725
3726 // type for the Agent_OnLoad and JVM_OnLoad entry points
3727 extern "C" {
3728 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3729 }
3730 // Find a command line agent library and return its entry point for
3731 // -agentlib: -agentpath: -Xrun
3732 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3733 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3734 OnLoadEntry_t on_load_entry = NULL;
3735 void *library = agent->os_lib(); // check if we have looked it up before
3736
3737 if (library == NULL) {
3738 char buffer[JVM_MAXPATHLEN];
3739 char ebuf[1024];
3740 const char *name = agent->name();
3741 const char *msg = "Could not find agent library ";
3742
3743 if (agent->is_absolute_path()) {
3744 library = os::dll_load(name, ebuf, sizeof ebuf);
3745 if (library == NULL) {
3746 const char *sub_msg = " in absolute path, with error: ";
3747 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3748 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3749 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3750 // If we can't find the agent, exit.
3751 vm_exit_during_initialization(buf, NULL);
3752 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3753 }
3754 } else {
3755 // Try to load the agent from the standard dll directory
3756 if (os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
3757 name)) {
3758 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3759 }
3760 #ifdef KERNEL
3761 // Download instrument dll
3762 if (library == NULL && strcmp(name, "instrument") == 0) {
3763 char *props = Arguments::get_kernel_properties();
3764 char *home = Arguments::get_java_home();
3765 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false"
3766 " sun.jkernel.DownloadManager -download client_jvm";
3767 size_t length = strlen(props) + strlen(home) + strlen(fmt) + 1;
3768 char *cmd = NEW_C_HEAP_ARRAY(char, length, mtThread);
3769 jio_snprintf(cmd, length, fmt, home, props);
3770 int status = os::fork_and_exec(cmd);
3771 FreeHeap(props);
3772 if (status == -1) {
3773 warning(cmd);
3774 vm_exit_during_initialization("fork_and_exec failed: %s",
3775 strerror(errno));
3776 }
3777 FREE_C_HEAP_ARRAY(char, cmd, mtThread);
3778 // when this comes back the instrument.dll should be where it belongs.
3779 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3780 }
3781 #endif // KERNEL
3782 if (library == NULL) { // Try the local directory
3783 char ns[1] = {0};
3784 if (os::dll_build_name(buffer, sizeof(buffer), ns, name)) {
3785 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3786 }
3787 if (library == NULL) {
3788 const char *sub_msg = " on the library path, with error: ";
3789 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3790 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3791 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3792 // If we can't find the agent, exit.
3793 vm_exit_during_initialization(buf, NULL);
3794 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3795 }
3796 }
3797 }
3798 agent->set_os_lib(library);
3799 }
3800
3801 // Find the OnLoad function.
3802 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
3803 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, os::dll_lookup(library, on_load_symbols[symbol_index]));
3804 if (on_load_entry != NULL) break;
3805 }
3806 return on_load_entry;
3807 }
3808
3809 // Find the JVM_OnLoad entry point
3810 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3811 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3812 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3813 }
3814
3815 // Find the Agent_OnLoad entry point
3816 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3817 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3818 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3819 }
3820
3821 // For backwards compatibility with -Xrun
3822 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3823 // treated like -agentpath:
3824 // Must be called before agent libraries are created
3825 void Threads::convert_vm_init_libraries_to_agents() {
3826 AgentLibrary* agent;
3827 AgentLibrary* next;
3828
3829 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3830 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3831 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3832
3833 // If there is an JVM_OnLoad function it will get called later,
3834 // otherwise see if there is an Agent_OnLoad
3835 if (on_load_entry == NULL) {
3836 on_load_entry = lookup_agent_on_load(agent);
3837 if (on_load_entry != NULL) {
3838 // switch it to the agent list -- so that Agent_OnLoad will be called,
3839 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3840 Arguments::convert_library_to_agent(agent);
3841 } else {
3842 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3843 }
3844 }
3845 }
3846 }
3847
3848 // Create agents for -agentlib: -agentpath: and converted -Xrun
3849 // Invokes Agent_OnLoad
3850 // Called very early -- before JavaThreads exist
3851 void Threads::create_vm_init_agents() {
3852 extern struct JavaVM_ main_vm;
3853 AgentLibrary* agent;
3854
3855 JvmtiExport::enter_onload_phase();
3856
3857 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3858 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3859
3860 if (on_load_entry != NULL) {
3861 // Invoke the Agent_OnLoad function
3862 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3863 if (err != JNI_OK) {
3864 vm_exit_during_initialization("agent library failed to init", agent->name());
3865 }
3866 } else {
3867 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3868 }
3869 }
3870 JvmtiExport::enter_primordial_phase();
3871 }
3872
3873 extern "C" {
3874 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3875 }
3876
3877 void Threads::shutdown_vm_agents() {
3878 // Send any Agent_OnUnload notifications
3879 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3880 extern struct JavaVM_ main_vm;
3881 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3882
3883 // Find the Agent_OnUnload function.
3884 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
3885 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3886 os::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
3887
3888 // Invoke the Agent_OnUnload function
3889 if (unload_entry != NULL) {
3890 JavaThread* thread = JavaThread::current();
3891 ThreadToNativeFromVM ttn(thread);
3892 HandleMark hm(thread);
3893 (*unload_entry)(&main_vm);
3894 break;
3895 }
3896 }
3897 }
3898 }
3899
3900 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3901 // Invokes JVM_OnLoad
3902 void Threads::create_vm_init_libraries() {
3903 extern struct JavaVM_ main_vm;
3904 AgentLibrary* agent;
3905
3906 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3907 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3908
3909 if (on_load_entry != NULL) {
3910 // Invoke the JVM_OnLoad function
3911 JavaThread* thread = JavaThread::current();
3912 ThreadToNativeFromVM ttn(thread);
3913 HandleMark hm(thread);
3914 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3915 if (err != JNI_OK) {
3916 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3917 }
3918 } else {
3919 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3920 }
3921 }
3922 }
3923
3924 // Last thread running calls java.lang.Shutdown.shutdown()
3925 void JavaThread::invoke_shutdown_hooks() {
3926 HandleMark hm(this);
3927
3928 // We could get here with a pending exception, if so clear it now.
3929 if (this->has_pending_exception()) {
3930 this->clear_pending_exception();
3931 }
3932
3933 EXCEPTION_MARK;
3934 Klass* k =
3935 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3936 THREAD);
3937 if (k != NULL) {
3938 // SystemDictionary::resolve_or_null will return null if there was
3939 // an exception. If we cannot load the Shutdown class, just don't
3940 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3941 // and finalizers (if runFinalizersOnExit is set) won't be run.
3942 // Note that if a shutdown hook was registered or runFinalizersOnExit
3943 // was called, the Shutdown class would have already been loaded
3944 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3945 instanceKlassHandle shutdown_klass (THREAD, k);
3946 JavaValue result(T_VOID);
3947 JavaCalls::call_static(&result,
3948 shutdown_klass,
3949 vmSymbols::shutdown_method_name(),
3950 vmSymbols::void_method_signature(),
3951 THREAD);
3952 }
3953 CLEAR_PENDING_EXCEPTION;
3954 }
3955
3956 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3957 // the program falls off the end of main(). Another VM exit path is through
3958 // vm_exit() when the program calls System.exit() to return a value or when
3959 // there is a serious error in VM. The two shutdown paths are not exactly
3960 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3961 // and VM_Exit op at VM level.
3962 //
3963 // Shutdown sequence:
3964 // + Shutdown native memory tracking if it is on
3965 // + Wait until we are the last non-daemon thread to execute
3966 // <-- every thing is still working at this moment -->
3967 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3968 // shutdown hooks, run finalizers if finalization-on-exit
3969 // + Call before_exit(), prepare for VM exit
3970 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3971 // currently the only user of this mechanism is File.deleteOnExit())
3972 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3973 // post thread end and vm death events to JVMTI,
3974 // stop signal thread
3975 // + Call JavaThread::exit(), it will:
3976 // > release JNI handle blocks, remove stack guard pages
3977 // > remove this thread from Threads list
3978 // <-- no more Java code from this thread after this point -->
3979 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3980 // the compiler threads at safepoint
3981 // <-- do not use anything that could get blocked by Safepoint -->
3982 // + Disable tracing at JNI/JVM barriers
3983 // + Set _vm_exited flag for threads that are still running native code
3984 // + Delete this thread
3985 // + Call exit_globals()
3986 // > deletes tty
3987 // > deletes PerfMemory resources
3988 // + Return to caller
3989
3990 bool Threads::destroy_vm() {
3991 JavaThread* thread = JavaThread::current();
3992
3993 #ifdef ASSERT
3994 _vm_complete = false;
3995 #endif
3996 // Wait until we are the last non-daemon thread to execute
3997 { MutexLocker nu(Threads_lock);
3998 while (Threads::number_of_non_daemon_threads() > 1 )
3999 // This wait should make safepoint checks, wait without a timeout,
4000 // and wait as a suspend-equivalent condition.
4001 //
4002 // Note: If the FlatProfiler is running and this thread is waiting
4003 // for another non-daemon thread to finish, then the FlatProfiler
4004 // is waiting for the external suspend request on this thread to
4005 // complete. wait_for_ext_suspend_completion() will eventually
4006 // timeout, but that takes time. Making this wait a suspend-
4007 // equivalent condition solves that timeout problem.
4008 //
4009 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
4010 Mutex::_as_suspend_equivalent_flag);
4011 }
4012
4013 // Shutdown NMT before exit. Otherwise,
4014 // it will run into trouble when system destroys static variables.
4015 MemTracker::shutdown(MemTracker::NMT_normal);
4016
4017 // Hang forever on exit if we are reporting an error.
4018 if (ShowMessageBoxOnError && is_error_reported()) {
4019 os::infinite_sleep();
4020 }
4021 os::wait_for_keypress_at_exit();
4022
4023 if (JDK_Version::is_jdk12x_version()) {
4024 // We are the last thread running, so check if finalizers should be run.
4025 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
4026 HandleMark rm(thread);
4027 Universe::run_finalizers_on_exit();
4028 } else {
4029 // run Java level shutdown hooks
4030 thread->invoke_shutdown_hooks();
4031 }
4032
4033 before_exit(thread);
4034
4035 thread->exit(true);
4036
4037 // Stop VM thread.
4038 {
4039 // 4945125 The vm thread comes to a safepoint during exit.
4040 // GC vm_operations can get caught at the safepoint, and the
4041 // heap is unparseable if they are caught. Grab the Heap_lock
4042 // to prevent this. The GC vm_operations will not be able to
4043 // queue until after the vm thread is dead.
4044 // After this point, we'll never emerge out of the safepoint before
4045 // the VM exits, so concurrent GC threads do not need to be explicitly
4046 // stopped; they remain inactive until the process exits.
4047 // Note: some concurrent G1 threads may be running during a safepoint,
4048 // but these will not be accessing the heap, just some G1-specific side
4049 // data structures that are not accessed by any other threads but them
4050 // after this point in a terminal safepoint.
4051
4052 MutexLocker ml(Heap_lock);
4053
4054 VMThread::wait_for_vm_thread_exit();
4055 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
4056 VMThread::destroy();
4057 }
4058
4059 // clean up ideal graph printers
4060 #if defined(COMPILER2) && !defined(PRODUCT)
4061 IdealGraphPrinter::clean_up();
4062 #endif
4063
4064 // Now, all Java threads are gone except daemon threads. Daemon threads
4065 // running Java code or in VM are stopped by the Safepoint. However,
4066 // daemon threads executing native code are still running. But they
4067 // will be stopped at native=>Java/VM barriers. Note that we can't
4068 // simply kill or suspend them, as it is inherently deadlock-prone.
4069
4070 #ifndef PRODUCT
4071 // disable function tracing at JNI/JVM barriers
4072 TraceJNICalls = false;
4073 TraceJVMCalls = false;
4074 TraceRuntimeCalls = false;
4075 #endif
4076
4077 VM_Exit::set_vm_exited();
4078
4079 notify_vm_shutdown();
4080
4081 delete thread;
4082
4083 // exit_globals() will delete tty
4084 exit_globals();
4085
4086 return true;
4087 }
4088
4089
4090 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
4091 if (version == JNI_VERSION_1_1) return JNI_TRUE;
4092 return is_supported_jni_version(version);
4093 }
4094
4095
4096 jboolean Threads::is_supported_jni_version(jint version) {
4097 if (version == JNI_VERSION_1_2) return JNI_TRUE;
4098 if (version == JNI_VERSION_1_4) return JNI_TRUE;
4099 if (version == JNI_VERSION_1_6) return JNI_TRUE;
4100 return JNI_FALSE;
4101 }
4102
4103
4104 void Threads::add(JavaThread* p, bool force_daemon) {
4105 // The threads lock must be owned at this point
4106 assert_locked_or_safepoint(Threads_lock);
4107
4108 // See the comment for this method in thread.hpp for its purpose and
4109 // why it is called here.
4110 p->initialize_queues();
4111 p->set_next(_thread_list);
4112 _thread_list = p;
4113 _number_of_threads++;
4114 oop threadObj = p->threadObj();
4115 bool daemon = true;
4116 // Bootstrapping problem: threadObj can be null for initial
4117 // JavaThread (or for threads attached via JNI)
4118 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
4119 _number_of_non_daemon_threads++;
4120 daemon = false;
4121 }
4122
4123 p->set_safepoint_visible(true);
4124
4125 ThreadService::add_thread(p, daemon);
4126
4127 // Possible GC point.
4128 Events::log(p, "Thread added: " INTPTR_FORMAT, p);
4129 }
4130
4131 void Threads::remove(JavaThread* p) {
4132 // Extra scope needed for Thread_lock, so we can check
4133 // that we do not remove thread without safepoint code notice
4134 { MutexLocker ml(Threads_lock);
4135
4136 assert(includes(p), "p must be present");
4137
4138 JavaThread* current = _thread_list;
4139 JavaThread* prev = NULL;
4140
4141 while (current != p) {
4142 prev = current;
4143 current = current->next();
4144 }
4145
4146 if (prev) {
4147 prev->set_next(current->next());
4148 } else {
4149 _thread_list = p->next();
4150 }
4151 _number_of_threads--;
4152 oop threadObj = p->threadObj();
4153 bool daemon = true;
4154 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
4155 _number_of_non_daemon_threads--;
4156 daemon = false;
4157
4158 // Only one thread left, do a notify on the Threads_lock so a thread waiting
4159 // on destroy_vm will wake up.
4160 if (number_of_non_daemon_threads() == 1)
4161 Threads_lock->notify_all();
4162 }
4163 ThreadService::remove_thread(p, daemon);
4164
4165 // Make sure that safepoint code disregard this thread. This is needed since
4166 // the thread might mess around with locks after this point. This can cause it
4167 // to do callbacks into the safepoint code. However, the safepoint code is not aware
4168 // of this thread since it is removed from the queue.
4169 p->set_terminated_value();
4170
4171 // Now, this thread is not visible to safepoint
4172 p->set_safepoint_visible(false);
4173 // once the thread becomes safepoint invisible, we can not use its per-thread
4174 // recorder. And Threads::do_threads() no longer walks this thread, so we have
4175 // to release its per-thread recorder here.
4176 MemTracker::thread_exiting(p);
4177 } // unlock Threads_lock
4178
4179 // Since Events::log uses a lock, we grab it outside the Threads_lock
4180 Events::log(p, "Thread exited: " INTPTR_FORMAT, p);
4181 }
4182
4183 // Threads_lock must be held when this is called (or must be called during a safepoint)
4184 bool Threads::includes(JavaThread* p) {
4185 assert(Threads_lock->is_locked(), "sanity check");
4186 ALL_JAVA_THREADS(q) {
4187 if (q == p ) {
4188 return true;
4189 }
4190 }
4191 return false;
4192 }
4193
4194 // Operations on the Threads list for GC. These are not explicitly locked,
4195 // but the garbage collector must provide a safe context for them to run.
4196 // In particular, these things should never be called when the Threads_lock
4197 // is held by some other thread. (Note: the Safepoint abstraction also
4198 // uses the Threads_lock to gurantee this property. It also makes sure that
4199 // all threads gets blocked when exiting or starting).
4200
4201 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
4202 ALL_JAVA_THREADS(p) {
4203 p->oops_do(f, cf);
4204 }
4205 VMThread::vm_thread()->oops_do(f, cf);
4206 }
4207
4208 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) {
4209 // Introduce a mechanism allowing parallel threads to claim threads as
4210 // root groups. Overhead should be small enough to use all the time,
4211 // even in sequential code.
4212 SharedHeap* sh = SharedHeap::heap();
4213 // Cannot yet substitute active_workers for n_par_threads
4214 // because of G1CollectedHeap::verify() use of
4215 // SharedHeap::process_strong_roots(). n_par_threads == 0 will
4216 // turn off parallelism in process_strong_roots while active_workers
4217 // is being used for parallelism elsewhere.
4218 bool is_par = sh->n_par_threads() > 0;
4219 assert(!is_par ||
4220 (SharedHeap::heap()->n_par_threads() ==
4221 SharedHeap::heap()->workers()->active_workers()), "Mismatch");
4222 int cp = SharedHeap::heap()->strong_roots_parity();
4223 ALL_JAVA_THREADS(p) {
4224 if (p->claim_oops_do(is_par, cp)) {
4225 p->oops_do(f, cf);
4226 }
4227 }
4228 VMThread* vmt = VMThread::vm_thread();
4229 if (vmt->claim_oops_do(is_par, cp)) {
4230 vmt->oops_do(f, cf);
4231 }
4232 }
4233
4234 #ifndef SERIALGC
4235 // Used by ParallelScavenge
4236 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
4237 ALL_JAVA_THREADS(p) {
4238 q->enqueue(new ThreadRootsTask(p));
4239 }
4240 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
4241 }
4242
4243 // Used by Parallel Old
4244 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
4245 ALL_JAVA_THREADS(p) {
4246 q->enqueue(new ThreadRootsMarkingTask(p));
4247 }
4248 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
4249 }
4250 #endif // SERIALGC
4251
4252 void Threads::nmethods_do(CodeBlobClosure* cf) {
4253 ALL_JAVA_THREADS(p) {
4254 p->nmethods_do(cf);
4255 }
4256 VMThread::vm_thread()->nmethods_do(cf);
4257 }
4258
4259 void Threads::metadata_do(void f(Metadata*)) {
4260 ALL_JAVA_THREADS(p) {
4261 p->metadata_do(f);
4262 }
4263 }
4264
4265 void Threads::gc_epilogue() {
4266 ALL_JAVA_THREADS(p) {
4267 p->gc_epilogue();
4268 }
4269 }
4270
4271 void Threads::gc_prologue() {
4272 ALL_JAVA_THREADS(p) {
4273 p->gc_prologue();
4274 }
4275 }
4276
4277 void Threads::deoptimized_wrt_marked_nmethods() {
4278 ALL_JAVA_THREADS(p) {
4279 p->deoptimized_wrt_marked_nmethods();
4280 }
4281 }
4282
4283
4284 // Get count Java threads that are waiting to enter the specified monitor.
4285 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
4286 address monitor, bool doLock) {
4287 assert(doLock || SafepointSynchronize::is_at_safepoint(),
4288 "must grab Threads_lock or be at safepoint");
4289 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
4290
4291 int i = 0;
4292 {
4293 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4294 ALL_JAVA_THREADS(p) {
4295 if (p->is_Compiler_thread()) continue;
4296
4297 address pending = (address)p->current_pending_monitor();
4298 if (pending == monitor) { // found a match
4299 if (i < count) result->append(p); // save the first count matches
4300 i++;
4301 }
4302 }
4303 }
4304 return result;
4305 }
4306
4307
4308 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
4309 assert(doLock ||
4310 Threads_lock->owned_by_self() ||
4311 SafepointSynchronize::is_at_safepoint(),
4312 "must grab Threads_lock or be at safepoint");
4313
4314 // NULL owner means not locked so we can skip the search
4315 if (owner == NULL) return NULL;
4316
4317 {
4318 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4319 ALL_JAVA_THREADS(p) {
4320 // first, see if owner is the address of a Java thread
4321 if (owner == (address)p) return p;
4322 }
4323 }
4324 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
4325 if (UseHeavyMonitors) return NULL;
4326
4327 //
4328 // If we didn't find a matching Java thread and we didn't force use of
4329 // heavyweight monitors, then the owner is the stack address of the
4330 // Lock Word in the owning Java thread's stack.
4331 //
4332 JavaThread* the_owner = NULL;
4333 {
4334 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4335 ALL_JAVA_THREADS(q) {
4336 if (q->is_lock_owned(owner)) {
4337 the_owner = q;
4338 break;
4339 }
4340 }
4341 }
4342 assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
4343 return the_owner;
4344 }
4345
4346 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
4347 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
4348 char buf[32];
4349 st->print_cr(os::local_time_string(buf, sizeof(buf)));
4350
4351 st->print_cr("Full thread dump %s (%s %s):",
4352 Abstract_VM_Version::vm_name(),
4353 Abstract_VM_Version::vm_release(),
4354 Abstract_VM_Version::vm_info_string()
4355 );
4356 st->cr();
4357
4358 #ifndef SERIALGC
4359 // Dump concurrent locks
4360 ConcurrentLocksDump concurrent_locks;
4361 if (print_concurrent_locks) {
4362 concurrent_locks.dump_at_safepoint();
4363 }
4364 #endif // SERIALGC
4365
4366 ALL_JAVA_THREADS(p) {
4367 ResourceMark rm;
4368 p->print_on(st);
4369 if (print_stacks) {
4370 if (internal_format) {
4371 p->trace_stack();
4372 } else {
4373 p->print_stack_on(st);
4374 }
4375 }
4376 st->cr();
4377 #ifndef SERIALGC
4378 if (print_concurrent_locks) {
4379 concurrent_locks.print_locks_on(p, st);
4380 }
4381 #endif // SERIALGC
4382 }
4383
4384 VMThread::vm_thread()->print_on(st);
4385 st->cr();
4386 Universe::heap()->print_gc_threads_on(st);
4387 WatcherThread* wt = WatcherThread::watcher_thread();
4388 if (wt != NULL) {
4389 wt->print_on(st);
4390 st->cr();
4391 }
4392 CompileBroker::print_compiler_threads_on(st);
4393 st->flush();
4394 }
4395
4396 // Threads::print_on_error() is called by fatal error handler. It's possible
4397 // that VM is not at safepoint and/or current thread is inside signal handler.
4398 // Don't print stack trace, as the stack may not be walkable. Don't allocate
4399 // memory (even in resource area), it might deadlock the error handler.
4400 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
4401 bool found_current = false;
4402 st->print_cr("Java Threads: ( => current thread )");
4403 ALL_JAVA_THREADS(thread) {
4404 bool is_current = (current == thread);
4405 found_current = found_current || is_current;
4406
4407 st->print("%s", is_current ? "=>" : " ");
4408
4409 st->print(PTR_FORMAT, thread);
4410 st->print(" ");
4411 thread->print_on_error(st, buf, buflen);
4412 st->cr();
4413 }
4414 st->cr();
4415
4416 st->print_cr("Other Threads:");
4417 if (VMThread::vm_thread()) {
4418 bool is_current = (current == VMThread::vm_thread());
4419 found_current = found_current || is_current;
4420 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
4421
4422 st->print(PTR_FORMAT, VMThread::vm_thread());
4423 st->print(" ");
4424 VMThread::vm_thread()->print_on_error(st, buf, buflen);
4425 st->cr();
4426 }
4427 WatcherThread* wt = WatcherThread::watcher_thread();
4428 if (wt != NULL) {
4429 bool is_current = (current == wt);
4430 found_current = found_current || is_current;
4431 st->print("%s", is_current ? "=>" : " ");
4432
4433 st->print(PTR_FORMAT, wt);
4434 st->print(" ");
4435 wt->print_on_error(st, buf, buflen);
4436 st->cr();
4437 }
4438 if (!found_current) {
4439 st->cr();
4440 st->print("=>" PTR_FORMAT " (exited) ", current);
4441 current->print_on_error(st, buf, buflen);
4442 st->cr();
4443 }
4444 }
4445
4446 // Internal SpinLock and Mutex
4447 // Based on ParkEvent
4448
4449 // Ad-hoc mutual exclusion primitives: SpinLock and Mux
4450 //
4451 // We employ SpinLocks _only for low-contention, fixed-length
4452 // short-duration critical sections where we're concerned
4453 // about native mutex_t or HotSpot Mutex:: latency.
4454 // The mux construct provides a spin-then-block mutual exclusion
4455 // mechanism.
4456 //
4457 // Testing has shown that contention on the ListLock guarding gFreeList
4458 // is common. If we implement ListLock as a simple SpinLock it's common
4459 // for the JVM to devolve to yielding with little progress. This is true
4460 // despite the fact that the critical sections protected by ListLock are
4461 // extremely short.
4462 //
4463 // TODO-FIXME: ListLock should be of type SpinLock.
4464 // We should make this a 1st-class type, integrated into the lock
4465 // hierarchy as leaf-locks. Critically, the SpinLock structure
4466 // should have sufficient padding to avoid false-sharing and excessive
4467 // cache-coherency traffic.
4468
4469
4470 typedef volatile int SpinLockT ;
4471
4472 void Thread::SpinAcquire (volatile int * adr, const char * LockName) {
4473 if (Atomic::cmpxchg (1, adr, 0) == 0) {
4474 return ; // normal fast-path return
4475 }
4476
4477 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
4478 TEVENT (SpinAcquire - ctx) ;
4479 int ctr = 0 ;
4480 int Yields = 0 ;
4481 for (;;) {
4482 while (*adr != 0) {
4483 ++ctr ;
4484 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
4485 if (Yields > 5) {
4486 // Consider using a simple NakedSleep() instead.
4487 // Then SpinAcquire could be called by non-JVM threads
4488 Thread::current()->_ParkEvent->park(1) ;
4489 } else {
4490 os::NakedYield() ;
4491 ++Yields ;
4492 }
4493 } else {
4494 SpinPause() ;
4495 }
4496 }
4497 if (Atomic::cmpxchg (1, adr, 0) == 0) return ;
4498 }
4499 }
4500
4501 void Thread::SpinRelease (volatile int * adr) {
4502 assert (*adr != 0, "invariant") ;
4503 OrderAccess::fence() ; // guarantee at least release consistency.
4504 // Roach-motel semantics.
4505 // It's safe if subsequent LDs and STs float "up" into the critical section,
4506 // but prior LDs and STs within the critical section can't be allowed
4507 // to reorder or float past the ST that releases the lock.
4508 *adr = 0 ;
4509 }
4510
4511 // muxAcquire and muxRelease:
4512 //
4513 // * muxAcquire and muxRelease support a single-word lock-word construct.
4514 // The LSB of the word is set IFF the lock is held.
4515 // The remainder of the word points to the head of a singly-linked list
4516 // of threads blocked on the lock.
4517 //
4518 // * The current implementation of muxAcquire-muxRelease uses its own
4519 // dedicated Thread._MuxEvent instance. If we're interested in
4520 // minimizing the peak number of extant ParkEvent instances then
4521 // we could eliminate _MuxEvent and "borrow" _ParkEvent as long
4522 // as certain invariants were satisfied. Specifically, care would need
4523 // to be taken with regards to consuming unpark() "permits".
4524 // A safe rule of thumb is that a thread would never call muxAcquire()
4525 // if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently
4526 // park(). Otherwise the _ParkEvent park() operation in muxAcquire() could
4527 // consume an unpark() permit intended for monitorenter, for instance.
4528 // One way around this would be to widen the restricted-range semaphore
4529 // implemented in park(). Another alternative would be to provide
4530 // multiple instances of the PlatformEvent() for each thread. One
4531 // instance would be dedicated to muxAcquire-muxRelease, for instance.
4532 //
4533 // * Usage:
4534 // -- Only as leaf locks
4535 // -- for short-term locking only as muxAcquire does not perform
4536 // thread state transitions.
4537 //
4538 // Alternatives:
4539 // * We could implement muxAcquire and muxRelease with MCS or CLH locks
4540 // but with parking or spin-then-park instead of pure spinning.
4541 // * Use Taura-Oyama-Yonenzawa locks.
4542 // * It's possible to construct a 1-0 lock if we encode the lockword as
4543 // (List,LockByte). Acquire will CAS the full lockword while Release
4544 // will STB 0 into the LockByte. The 1-0 scheme admits stranding, so
4545 // acquiring threads use timers (ParkTimed) to detect and recover from
4546 // the stranding window. Thread/Node structures must be aligned on 256-byte
4547 // boundaries by using placement-new.
4548 // * Augment MCS with advisory back-link fields maintained with CAS().
4549 // Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner.
4550 // The validity of the backlinks must be ratified before we trust the value.
4551 // If the backlinks are invalid the exiting thread must back-track through the
4552 // the forward links, which are always trustworthy.
4553 // * Add a successor indication. The LockWord is currently encoded as
4554 // (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable
4555 // to provide the usual futile-wakeup optimization.
4556 // See RTStt for details.
4557 // * Consider schedctl.sc_nopreempt to cover the critical section.
4558 //
4559
4560
4561 typedef volatile intptr_t MutexT ; // Mux Lock-word
4562 enum MuxBits { LOCKBIT = 1 } ;
4563
4564 void Thread::muxAcquire (volatile intptr_t * Lock, const char * LockName) {
4565 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4566 if (w == 0) return ;
4567 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4568 return ;
4569 }
4570
4571 TEVENT (muxAcquire - Contention) ;
4572 ParkEvent * const Self = Thread::current()->_MuxEvent ;
4573 assert ((intptr_t(Self) & LOCKBIT) == 0, "invariant") ;
4574 for (;;) {
4575 int its = (os::is_MP() ? 100 : 0) + 1 ;
4576
4577 // Optional spin phase: spin-then-park strategy
4578 while (--its >= 0) {
4579 w = *Lock ;
4580 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4581 return ;
4582 }
4583 }
4584
4585 Self->reset() ;
4586 Self->OnList = intptr_t(Lock) ;
4587 // The following fence() isn't _strictly necessary as the subsequent
4588 // CAS() both serializes execution and ratifies the fetched *Lock value.
4589 OrderAccess::fence();
4590 for (;;) {
4591 w = *Lock ;
4592 if ((w & LOCKBIT) == 0) {
4593 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4594 Self->OnList = 0 ; // hygiene - allows stronger asserts
4595 return ;
4596 }
4597 continue ; // Interference -- *Lock changed -- Just retry
4598 }
4599 assert (w & LOCKBIT, "invariant") ;
4600 Self->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4601 if (Atomic::cmpxchg_ptr (intptr_t(Self)|LOCKBIT, Lock, w) == w) break ;
4602 }
4603
4604 while (Self->OnList != 0) {
4605 Self->park() ;
4606 }
4607 }
4608 }
4609
4610 void Thread::muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) {
4611 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4612 if (w == 0) return ;
4613 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4614 return ;
4615 }
4616
4617 TEVENT (muxAcquire - Contention) ;
4618 ParkEvent * ReleaseAfter = NULL ;
4619 if (ev == NULL) {
4620 ev = ReleaseAfter = ParkEvent::Allocate (NULL) ;
4621 }
4622 assert ((intptr_t(ev) & LOCKBIT) == 0, "invariant") ;
4623 for (;;) {
4624 guarantee (ev->OnList == 0, "invariant") ;
4625 int its = (os::is_MP() ? 100 : 0) + 1 ;
4626
4627 // Optional spin phase: spin-then-park strategy
4628 while (--its >= 0) {
4629 w = *Lock ;
4630 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4631 if (ReleaseAfter != NULL) {
4632 ParkEvent::Release (ReleaseAfter) ;
4633 }
4634 return ;
4635 }
4636 }
4637
4638 ev->reset() ;
4639 ev->OnList = intptr_t(Lock) ;
4640 // The following fence() isn't _strictly necessary as the subsequent
4641 // CAS() both serializes execution and ratifies the fetched *Lock value.
4642 OrderAccess::fence();
4643 for (;;) {
4644 w = *Lock ;
4645 if ((w & LOCKBIT) == 0) {
4646 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4647 ev->OnList = 0 ;
4648 // We call ::Release while holding the outer lock, thus
4649 // artificially lengthening the critical section.
4650 // Consider deferring the ::Release() until the subsequent unlock(),
4651 // after we've dropped the outer lock.
4652 if (ReleaseAfter != NULL) {
4653 ParkEvent::Release (ReleaseAfter) ;
4654 }
4655 return ;
4656 }
4657 continue ; // Interference -- *Lock changed -- Just retry
4658 }
4659 assert (w & LOCKBIT, "invariant") ;
4660 ev->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4661 if (Atomic::cmpxchg_ptr (intptr_t(ev)|LOCKBIT, Lock, w) == w) break ;
4662 }
4663
4664 while (ev->OnList != 0) {
4665 ev->park() ;
4666 }
4667 }
4668 }
4669
4670 // Release() must extract a successor from the list and then wake that thread.
4671 // It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme
4672 // similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based
4673 // Release() would :
4674 // (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list.
4675 // (B) Extract a successor from the private list "in-hand"
4676 // (C) attempt to CAS() the residual back into *Lock over null.
4677 // If there were any newly arrived threads and the CAS() would fail.
4678 // In that case Release() would detach the RATs, re-merge the list in-hand
4679 // with the RATs and repeat as needed. Alternately, Release() might
4680 // detach and extract a successor, but then pass the residual list to the wakee.
4681 // The wakee would be responsible for reattaching and remerging before it
4682 // competed for the lock.
4683 //
4684 // Both "pop" and DMR are immune from ABA corruption -- there can be
4685 // multiple concurrent pushers, but only one popper or detacher.
4686 // This implementation pops from the head of the list. This is unfair,
4687 // but tends to provide excellent throughput as hot threads remain hot.
4688 // (We wake recently run threads first).
4689
4690 void Thread::muxRelease (volatile intptr_t * Lock) {
4691 for (;;) {
4692 const intptr_t w = Atomic::cmpxchg_ptr (0, Lock, LOCKBIT) ;
4693 assert (w & LOCKBIT, "invariant") ;
4694 if (w == LOCKBIT) return ;
4695 ParkEvent * List = (ParkEvent *) (w & ~LOCKBIT) ;
4696 assert (List != NULL, "invariant") ;
4697 assert (List->OnList == intptr_t(Lock), "invariant") ;
4698 ParkEvent * nxt = List->ListNext ;
4699
4700 // The following CAS() releases the lock and pops the head element.
4701 if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) {
4702 continue ;
4703 }
4704 List->OnList = 0 ;
4705 OrderAccess::fence() ;
4706 List->unpark () ;
4707 return ;
4708 }
4709 }
4710
4711
4712 void Threads::verify() {
4713 ALL_JAVA_THREADS(p) {
4714 p->verify();
4715 }
4716 VMThread* thread = VMThread::vm_thread();
4717 if (thread != NULL) thread->verify();
4718 }