Thu, 24 May 2018 19:24:53 +0800
#7046 Disable the compilation when branch offset is beyond short branch
Contributed-by: fujie, aoqi
1 /*
2 * Copyright (c) 1997, 2016, 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 */
25 /*
26 * This file has been modified by Loongson Technology in 2015. These
27 * modifications are Copyright (c) 2015 Loongson Technology, and are made
28 * available on the same license terms set forth above.
29 */
31 #include "precompiled.hpp"
32 #include "classfile/classLoader.hpp"
33 #include "classfile/javaClasses.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "classfile/vmSymbols.hpp"
36 #include "code/scopeDesc.hpp"
37 #include "compiler/compileBroker.hpp"
38 #include "interpreter/interpreter.hpp"
39 #include "interpreter/linkResolver.hpp"
40 #include "interpreter/oopMapCache.hpp"
41 #include "jvmtifiles/jvmtiEnv.hpp"
42 #include "memory/gcLocker.inline.hpp"
43 #include "memory/metaspaceShared.hpp"
44 #include "memory/oopFactory.hpp"
45 #include "memory/universe.inline.hpp"
46 #include "oops/instanceKlass.hpp"
47 #include "oops/objArrayOop.hpp"
48 #include "oops/oop.inline.hpp"
49 #include "oops/symbol.hpp"
50 #include "prims/jvm_misc.hpp"
51 #include "prims/jvmtiExport.hpp"
52 #include "prims/jvmtiThreadState.hpp"
53 #include "prims/privilegedStack.hpp"
54 #include "runtime/arguments.hpp"
55 #include "runtime/biasedLocking.hpp"
56 #include "runtime/deoptimization.hpp"
57 #include "runtime/fprofiler.hpp"
58 #include "runtime/frame.inline.hpp"
59 #include "runtime/init.hpp"
60 #include "runtime/interfaceSupport.hpp"
61 #include "runtime/java.hpp"
62 #include "runtime/javaCalls.hpp"
63 #include "runtime/jniPeriodicChecker.hpp"
64 #include "runtime/memprofiler.hpp"
65 #include "runtime/mutexLocker.hpp"
66 #include "runtime/objectMonitor.hpp"
67 #include "runtime/orderAccess.inline.hpp"
68 #include "runtime/osThread.hpp"
69 #include "runtime/safepoint.hpp"
70 #include "runtime/sharedRuntime.hpp"
71 #include "runtime/statSampler.hpp"
72 #include "runtime/stubRoutines.hpp"
73 #include "runtime/task.hpp"
74 #include "runtime/thread.inline.hpp"
75 #include "runtime/threadCritical.hpp"
76 #include "runtime/threadLocalStorage.hpp"
77 #include "runtime/vframe.hpp"
78 #include "runtime/vframeArray.hpp"
79 #include "runtime/vframe_hp.hpp"
80 #include "runtime/vmThread.hpp"
81 #include "runtime/vm_operations.hpp"
82 #include "services/attachListener.hpp"
83 #include "services/management.hpp"
84 #include "services/memTracker.hpp"
85 #include "services/threadService.hpp"
86 #include "trace/tracing.hpp"
87 #include "trace/traceMacros.hpp"
88 #include "utilities/defaultStream.hpp"
89 #include "utilities/dtrace.hpp"
90 #include "utilities/events.hpp"
91 #include "utilities/preserveException.hpp"
92 #include "utilities/macros.hpp"
93 #ifdef TARGET_OS_FAMILY_linux
94 # include "os_linux.inline.hpp"
95 #endif
96 #ifdef TARGET_OS_FAMILY_solaris
97 # include "os_solaris.inline.hpp"
98 #endif
99 #ifdef TARGET_OS_FAMILY_windows
100 # include "os_windows.inline.hpp"
101 #endif
102 #ifdef TARGET_OS_FAMILY_bsd
103 # include "os_bsd.inline.hpp"
104 #endif
105 #if INCLUDE_ALL_GCS
106 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
107 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
108 #include "gc_implementation/parallelScavenge/pcTasks.hpp"
109 #endif // INCLUDE_ALL_GCS
110 #ifdef COMPILER1
111 #include "c1/c1_Compiler.hpp"
112 #endif
113 #ifdef COMPILER2
114 #include "opto/c2compiler.hpp"
115 #include "opto/idealGraphPrinter.hpp"
116 #endif
117 #if INCLUDE_RTM_OPT
118 #include "runtime/rtmLocking.hpp"
119 #endif
121 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
123 #ifdef DTRACE_ENABLED
125 // Only bother with this argument setup if dtrace is available
127 #ifndef USDT2
128 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin);
129 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end);
130 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t,
131 intptr_t, intptr_t, bool);
132 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t,
133 intptr_t, intptr_t, bool);
135 #define DTRACE_THREAD_PROBE(probe, javathread) \
136 { \
137 ResourceMark rm(this); \
138 int len = 0; \
139 const char* name = (javathread)->get_thread_name(); \
140 len = strlen(name); \
141 HS_DTRACE_PROBE5(hotspot, thread__##probe, \
142 name, len, \
143 java_lang_Thread::thread_id((javathread)->threadObj()), \
144 (javathread)->osthread()->thread_id(), \
145 java_lang_Thread::is_daemon((javathread)->threadObj())); \
146 }
148 #else /* USDT2 */
150 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
151 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
153 #define DTRACE_THREAD_PROBE(probe, javathread) \
154 { \
155 ResourceMark rm(this); \
156 int len = 0; \
157 const char* name = (javathread)->get_thread_name(); \
158 len = strlen(name); \
159 HOTSPOT_THREAD_PROBE_##probe( /* probe = start, stop */ \
160 (char *) name, len, \
161 java_lang_Thread::thread_id((javathread)->threadObj()), \
162 (uintptr_t) (javathread)->osthread()->thread_id(), \
163 java_lang_Thread::is_daemon((javathread)->threadObj())); \
164 }
166 #endif /* USDT2 */
168 #else // ndef DTRACE_ENABLED
170 #define DTRACE_THREAD_PROBE(probe, javathread)
172 #endif // ndef DTRACE_ENABLED
175 // Class hierarchy
176 // - Thread
177 // - VMThread
178 // - WatcherThread
179 // - ConcurrentMarkSweepThread
180 // - JavaThread
181 // - CompilerThread
183 // ======= Thread ========
184 // Support for forcing alignment of thread objects for biased locking
185 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
186 if (UseBiasedLocking) {
187 const int alignment = markOopDesc::biased_lock_alignment;
188 size_t aligned_size = size + (alignment - sizeof(intptr_t));
189 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
190 : AllocateHeap(aligned_size, flags, CURRENT_PC,
191 AllocFailStrategy::RETURN_NULL);
192 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment);
193 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
194 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
195 "JavaThread alignment code overflowed allocated storage");
196 if (TraceBiasedLocking) {
197 if (aligned_addr != real_malloc_addr)
198 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
199 real_malloc_addr, aligned_addr);
200 }
201 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
202 return aligned_addr;
203 } else {
204 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
205 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
206 }
207 }
209 void Thread::operator delete(void* p) {
210 if (UseBiasedLocking) {
211 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
212 FreeHeap(real_malloc_addr, mtThread);
213 } else {
214 FreeHeap(p, mtThread);
215 }
216 }
219 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
220 // JavaThread
223 Thread::Thread() {
224 // stack and get_thread
225 set_stack_base(NULL);
226 set_stack_size(0);
227 set_self_raw_id(0);
228 set_lgrp_id(-1);
230 // allocated data structures
231 set_osthread(NULL);
232 set_resource_area(new (mtThread)ResourceArea());
233 DEBUG_ONLY(_current_resource_mark = NULL;)
234 set_handle_area(new (mtThread) HandleArea(NULL));
235 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, true));
236 set_active_handles(NULL);
237 set_free_handle_block(NULL);
238 set_last_handle_mark(NULL);
240 // This initial value ==> never claimed.
241 _oops_do_parity = 0;
243 _metadata_on_stack_buffer = NULL;
245 // the handle mark links itself to last_handle_mark
246 new HandleMark(this);
248 // plain initialization
249 debug_only(_owned_locks = NULL;)
250 debug_only(_allow_allocation_count = 0;)
251 NOT_PRODUCT(_allow_safepoint_count = 0;)
252 NOT_PRODUCT(_skip_gcalot = false;)
253 _jvmti_env_iteration_count = 0;
254 set_allocated_bytes(0);
255 _vm_operation_started_count = 0;
256 _vm_operation_completed_count = 0;
257 _current_pending_monitor = NULL;
258 _current_pending_monitor_is_from_java = true;
259 _current_waiting_monitor = NULL;
260 _num_nested_signal = 0;
261 omFreeList = NULL ;
262 omFreeCount = 0 ;
263 omFreeProvision = 32 ;
264 omInUseList = NULL ;
265 omInUseCount = 0 ;
267 #ifdef ASSERT
268 _visited_for_critical_count = false;
269 #endif
271 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
272 _suspend_flags = 0;
274 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
275 _hashStateX = os::random() ;
276 _hashStateY = 842502087 ;
277 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
278 _hashStateW = 273326509 ;
280 _OnTrap = 0 ;
281 _schedctl = NULL ;
282 _Stalled = 0 ;
283 _TypeTag = 0x2BAD ;
285 // Many of the following fields are effectively final - immutable
286 // Note that nascent threads can't use the Native Monitor-Mutex
287 // construct until the _MutexEvent is initialized ...
288 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
289 // we might instead use a stack of ParkEvents that we could provision on-demand.
290 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
291 // and ::Release()
292 _ParkEvent = ParkEvent::Allocate (this) ;
293 _SleepEvent = ParkEvent::Allocate (this) ;
294 _MutexEvent = ParkEvent::Allocate (this) ;
295 _MuxEvent = ParkEvent::Allocate (this) ;
297 #ifdef CHECK_UNHANDLED_OOPS
298 if (CheckUnhandledOops) {
299 _unhandled_oops = new UnhandledOops(this);
300 }
301 #endif // CHECK_UNHANDLED_OOPS
302 #ifdef ASSERT
303 if (UseBiasedLocking) {
304 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
305 assert(this == _real_malloc_address ||
306 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
307 "bug in forced alignment of thread objects");
308 }
309 #endif /* ASSERT */
310 }
312 void Thread::initialize_thread_local_storage() {
313 // Note: Make sure this method only calls
314 // non-blocking operations. Otherwise, it might not work
315 // with the thread-startup/safepoint interaction.
317 // During Java thread startup, safepoint code should allow this
318 // method to complete because it may need to allocate memory to
319 // store information for the new thread.
321 // initialize structure dependent on thread local storage
322 ThreadLocalStorage::set_thread(this);
323 }
325 void Thread::record_stack_base_and_size() {
326 set_stack_base(os::current_stack_base());
327 set_stack_size(os::current_stack_size());
328 if (is_Java_thread()) {
329 ((JavaThread*) this)->set_stack_overflow_limit();
330 }
331 // CR 7190089: on Solaris, primordial thread's stack is adjusted
332 // in initialize_thread(). Without the adjustment, stack size is
333 // incorrect if stack is set to unlimited (ulimit -s unlimited).
334 // So far, only Solaris has real implementation of initialize_thread().
335 //
336 // set up any platform-specific state.
337 os::initialize_thread(this);
339 #if INCLUDE_NMT
340 // record thread's native stack, stack grows downward
341 address stack_low_addr = stack_base() - stack_size();
342 MemTracker::record_thread_stack(stack_low_addr, stack_size());
343 #endif // INCLUDE_NMT
344 }
347 Thread::~Thread() {
348 // Reclaim the objectmonitors from the omFreeList of the moribund thread.
349 ObjectSynchronizer::omFlush (this) ;
351 EVENT_THREAD_DESTRUCT(this);
353 // stack_base can be NULL if the thread is never started or exited before
354 // record_stack_base_and_size called. Although, we would like to ensure
355 // that all started threads do call record_stack_base_and_size(), there is
356 // not proper way to enforce that.
357 #if INCLUDE_NMT
358 if (_stack_base != NULL) {
359 address low_stack_addr = stack_base() - stack_size();
360 MemTracker::release_thread_stack(low_stack_addr, stack_size());
361 #ifdef ASSERT
362 set_stack_base(NULL);
363 #endif
364 }
365 #endif // INCLUDE_NMT
367 // deallocate data structures
368 delete resource_area();
369 // since the handle marks are using the handle area, we have to deallocated the root
370 // handle mark before deallocating the thread's handle area,
371 assert(last_handle_mark() != NULL, "check we have an element");
372 delete last_handle_mark();
373 assert(last_handle_mark() == NULL, "check we have reached the end");
375 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
376 // We NULL out the fields for good hygiene.
377 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
378 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
379 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
380 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
382 delete handle_area();
383 delete metadata_handles();
385 // osthread() can be NULL, if creation of thread failed.
386 if (osthread() != NULL) os::free_thread(osthread());
388 delete _SR_lock;
390 // clear thread local storage if the Thread is deleting itself
391 if (this == Thread::current()) {
392 ThreadLocalStorage::set_thread(NULL);
393 } else {
394 // In the case where we're not the current thread, invalidate all the
395 // caches in case some code tries to get the current thread or the
396 // thread that was destroyed, and gets stale information.
397 ThreadLocalStorage::invalidate_all();
398 }
399 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
400 }
402 // NOTE: dummy function for assertion purpose.
403 void Thread::run() {
404 ShouldNotReachHere();
405 }
407 #ifdef ASSERT
408 // Private method to check for dangling thread pointer
409 void check_for_dangling_thread_pointer(Thread *thread) {
410 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
411 "possibility of dangling Thread pointer");
412 }
413 #endif
416 #ifndef PRODUCT
417 // Tracing method for basic thread operations
418 void Thread::trace(const char* msg, const Thread* const thread) {
419 if (!TraceThreadEvents) return;
420 ResourceMark rm;
421 ThreadCritical tc;
422 const char *name = "non-Java thread";
423 int prio = -1;
424 if (thread->is_Java_thread()
425 && !thread->is_Compiler_thread()) {
426 // The Threads_lock must be held to get information about
427 // this thread but may not be in some situations when
428 // tracing thread events.
429 bool release_Threads_lock = false;
430 if (!Threads_lock->owned_by_self()) {
431 Threads_lock->lock();
432 release_Threads_lock = true;
433 }
434 JavaThread* jt = (JavaThread *)thread;
435 name = (char *)jt->get_thread_name();
436 oop thread_oop = jt->threadObj();
437 if (thread_oop != NULL) {
438 prio = java_lang_Thread::priority(thread_oop);
439 }
440 if (release_Threads_lock) {
441 Threads_lock->unlock();
442 }
443 }
444 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
445 }
446 #endif
449 ThreadPriority Thread::get_priority(const Thread* const thread) {
450 trace("get priority", thread);
451 ThreadPriority priority;
452 // Can return an error!
453 (void)os::get_priority(thread, priority);
454 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
455 return priority;
456 }
458 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
459 trace("set priority", thread);
460 debug_only(check_for_dangling_thread_pointer(thread);)
461 // Can return an error!
462 (void)os::set_priority(thread, priority);
463 }
466 void Thread::start(Thread* thread) {
467 trace("start", thread);
468 // Start is different from resume in that its safety is guaranteed by context or
469 // being called from a Java method synchronized on the Thread object.
470 if (!DisableStartThread) {
471 if (thread->is_Java_thread()) {
472 // Initialize the thread state to RUNNABLE before starting this thread.
473 // Can not set it after the thread started because we do not know the
474 // exact thread state at that time. It could be in MONITOR_WAIT or
475 // in SLEEPING or some other state.
476 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
477 java_lang_Thread::RUNNABLE);
478 }
479 os::start_thread(thread);
480 }
481 }
483 // Enqueue a VM_Operation to do the job for us - sometime later
484 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
485 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
486 VMThread::execute(vm_stop);
487 }
490 //
491 // Check if an external suspend request has completed (or has been
492 // cancelled). Returns true if the thread is externally suspended and
493 // false otherwise.
494 //
495 // The bits parameter returns information about the code path through
496 // the routine. Useful for debugging:
497 //
498 // set in is_ext_suspend_completed():
499 // 0x00000001 - routine was entered
500 // 0x00000010 - routine return false at end
501 // 0x00000100 - thread exited (return false)
502 // 0x00000200 - suspend request cancelled (return false)
503 // 0x00000400 - thread suspended (return true)
504 // 0x00001000 - thread is in a suspend equivalent state (return true)
505 // 0x00002000 - thread is native and walkable (return true)
506 // 0x00004000 - thread is native_trans and walkable (needed retry)
507 //
508 // set in wait_for_ext_suspend_completion():
509 // 0x00010000 - routine was entered
510 // 0x00020000 - suspend request cancelled before loop (return false)
511 // 0x00040000 - thread suspended before loop (return true)
512 // 0x00080000 - suspend request cancelled in loop (return false)
513 // 0x00100000 - thread suspended in loop (return true)
514 // 0x00200000 - suspend not completed during retry loop (return false)
515 //
517 // Helper class for tracing suspend wait debug bits.
518 //
519 // 0x00000100 indicates that the target thread exited before it could
520 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
521 // 0x00080000 each indicate a cancelled suspend request so they don't
522 // count as wait failures either.
523 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
525 class TraceSuspendDebugBits : public StackObj {
526 private:
527 JavaThread * jt;
528 bool is_wait;
529 bool called_by_wait; // meaningful when !is_wait
530 uint32_t * bits;
532 public:
533 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
534 uint32_t *_bits) {
535 jt = _jt;
536 is_wait = _is_wait;
537 called_by_wait = _called_by_wait;
538 bits = _bits;
539 }
541 ~TraceSuspendDebugBits() {
542 if (!is_wait) {
543 #if 1
544 // By default, don't trace bits for is_ext_suspend_completed() calls.
545 // That trace is very chatty.
546 return;
547 #else
548 if (!called_by_wait) {
549 // If tracing for is_ext_suspend_completed() is enabled, then only
550 // trace calls to it from wait_for_ext_suspend_completion()
551 return;
552 }
553 #endif
554 }
556 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
557 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
558 MutexLocker ml(Threads_lock); // needed for get_thread_name()
559 ResourceMark rm;
561 tty->print_cr(
562 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
563 jt->get_thread_name(), *bits);
565 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
566 }
567 }
568 }
569 };
570 #undef DEBUG_FALSE_BITS
573 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
574 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
576 bool did_trans_retry = false; // only do thread_in_native_trans retry once
577 bool do_trans_retry; // flag to force the retry
579 *bits |= 0x00000001;
581 do {
582 do_trans_retry = false;
584 if (is_exiting()) {
585 // Thread is in the process of exiting. This is always checked
586 // first to reduce the risk of dereferencing a freed JavaThread.
587 *bits |= 0x00000100;
588 return false;
589 }
591 if (!is_external_suspend()) {
592 // Suspend request is cancelled. This is always checked before
593 // is_ext_suspended() to reduce the risk of a rogue resume
594 // confusing the thread that made the suspend request.
595 *bits |= 0x00000200;
596 return false;
597 }
599 if (is_ext_suspended()) {
600 // thread is suspended
601 *bits |= 0x00000400;
602 return true;
603 }
605 // Now that we no longer do hard suspends of threads running
606 // native code, the target thread can be changing thread state
607 // while we are in this routine:
608 //
609 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
610 //
611 // We save a copy of the thread state as observed at this moment
612 // and make our decision about suspend completeness based on the
613 // copy. This closes the race where the thread state is seen as
614 // _thread_in_native_trans in the if-thread_blocked check, but is
615 // seen as _thread_blocked in if-thread_in_native_trans check.
616 JavaThreadState save_state = thread_state();
618 if (save_state == _thread_blocked && is_suspend_equivalent()) {
619 // If the thread's state is _thread_blocked and this blocking
620 // condition is known to be equivalent to a suspend, then we can
621 // consider the thread to be externally suspended. This means that
622 // the code that sets _thread_blocked has been modified to do
623 // self-suspension if the blocking condition releases. We also
624 // used to check for CONDVAR_WAIT here, but that is now covered by
625 // the _thread_blocked with self-suspension check.
626 //
627 // Return true since we wouldn't be here unless there was still an
628 // external suspend request.
629 *bits |= 0x00001000;
630 return true;
631 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
632 // Threads running native code will self-suspend on native==>VM/Java
633 // transitions. If its stack is walkable (should always be the case
634 // unless this function is called before the actual java_suspend()
635 // call), then the wait is done.
636 *bits |= 0x00002000;
637 return true;
638 } else if (!called_by_wait && !did_trans_retry &&
639 save_state == _thread_in_native_trans &&
640 frame_anchor()->walkable()) {
641 // The thread is transitioning from thread_in_native to another
642 // thread state. check_safepoint_and_suspend_for_native_trans()
643 // will force the thread to self-suspend. If it hasn't gotten
644 // there yet we may have caught the thread in-between the native
645 // code check above and the self-suspend. Lucky us. If we were
646 // called by wait_for_ext_suspend_completion(), then it
647 // will be doing the retries so we don't have to.
648 //
649 // Since we use the saved thread state in the if-statement above,
650 // there is a chance that the thread has already transitioned to
651 // _thread_blocked by the time we get here. In that case, we will
652 // make a single unnecessary pass through the logic below. This
653 // doesn't hurt anything since we still do the trans retry.
655 *bits |= 0x00004000;
657 // Once the thread leaves thread_in_native_trans for another
658 // thread state, we break out of this retry loop. We shouldn't
659 // need this flag to prevent us from getting back here, but
660 // sometimes paranoia is good.
661 did_trans_retry = true;
663 // We wait for the thread to transition to a more usable state.
664 for (int i = 1; i <= SuspendRetryCount; i++) {
665 // We used to do an "os::yield_all(i)" call here with the intention
666 // that yielding would increase on each retry. However, the parameter
667 // is ignored on Linux which means the yield didn't scale up. Waiting
668 // on the SR_lock below provides a much more predictable scale up for
669 // the delay. It also provides a simple/direct point to check for any
670 // safepoint requests from the VMThread
672 // temporarily drops SR_lock while doing wait with safepoint check
673 // (if we're a JavaThread - the WatcherThread can also call this)
674 // and increase delay with each retry
675 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
677 // check the actual thread state instead of what we saved above
678 if (thread_state() != _thread_in_native_trans) {
679 // the thread has transitioned to another thread state so
680 // try all the checks (except this one) one more time.
681 do_trans_retry = true;
682 break;
683 }
684 } // end retry loop
687 }
688 } while (do_trans_retry);
690 *bits |= 0x00000010;
691 return false;
692 }
694 //
695 // Wait for an external suspend request to complete (or be cancelled).
696 // Returns true if the thread is externally suspended and false otherwise.
697 //
698 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
699 uint32_t *bits) {
700 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
701 false /* !called_by_wait */, bits);
703 // local flag copies to minimize SR_lock hold time
704 bool is_suspended;
705 bool pending;
706 uint32_t reset_bits;
708 // set a marker so is_ext_suspend_completed() knows we are the caller
709 *bits |= 0x00010000;
711 // We use reset_bits to reinitialize the bits value at the top of
712 // each retry loop. This allows the caller to make use of any
713 // unused bits for their own marking purposes.
714 reset_bits = *bits;
716 {
717 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
718 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
719 delay, bits);
720 pending = is_external_suspend();
721 }
722 // must release SR_lock to allow suspension to complete
724 if (!pending) {
725 // A cancelled suspend request is the only false return from
726 // is_ext_suspend_completed() that keeps us from entering the
727 // retry loop.
728 *bits |= 0x00020000;
729 return false;
730 }
732 if (is_suspended) {
733 *bits |= 0x00040000;
734 return true;
735 }
737 for (int i = 1; i <= retries; i++) {
738 *bits = reset_bits; // reinit to only track last retry
740 // We used to do an "os::yield_all(i)" call here with the intention
741 // that yielding would increase on each retry. However, the parameter
742 // is ignored on Linux which means the yield didn't scale up. Waiting
743 // on the SR_lock below provides a much more predictable scale up for
744 // the delay. It also provides a simple/direct point to check for any
745 // safepoint requests from the VMThread
747 {
748 MutexLocker ml(SR_lock());
749 // wait with safepoint check (if we're a JavaThread - the WatcherThread
750 // can also call this) and increase delay with each retry
751 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
753 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
754 delay, bits);
756 // It is possible for the external suspend request to be cancelled
757 // (by a resume) before the actual suspend operation is completed.
758 // Refresh our local copy to see if we still need to wait.
759 pending = is_external_suspend();
760 }
762 if (!pending) {
763 // A cancelled suspend request is the only false return from
764 // is_ext_suspend_completed() that keeps us from staying in the
765 // retry loop.
766 *bits |= 0x00080000;
767 return false;
768 }
770 if (is_suspended) {
771 *bits |= 0x00100000;
772 return true;
773 }
774 } // end retry loop
776 // thread did not suspend after all our retries
777 *bits |= 0x00200000;
778 return false;
779 }
781 #ifndef PRODUCT
782 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
784 // This should not need to be atomic as the only way for simultaneous
785 // updates is via interrupts. Even then this should be rare or non-existant
786 // and we don't care that much anyway.
788 int index = _jmp_ring_index;
789 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
790 _jmp_ring[index]._target = (intptr_t) target;
791 _jmp_ring[index]._instruction = (intptr_t) instr;
792 _jmp_ring[index]._file = file;
793 _jmp_ring[index]._line = line;
794 }
795 #endif /* PRODUCT */
797 // Called by flat profiler
798 // Callers have already called wait_for_ext_suspend_completion
799 // The assertion for that is currently too complex to put here:
800 bool JavaThread::profile_last_Java_frame(frame* _fr) {
801 bool gotframe = false;
802 // self suspension saves needed state.
803 if (has_last_Java_frame() && _anchor.walkable()) {
804 *_fr = pd_last_frame();
805 gotframe = true;
806 }
807 return gotframe;
808 }
810 void Thread::interrupt(Thread* thread) {
811 trace("interrupt", thread);
812 debug_only(check_for_dangling_thread_pointer(thread);)
813 os::interrupt(thread);
814 }
816 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
817 trace("is_interrupted", thread);
818 debug_only(check_for_dangling_thread_pointer(thread);)
819 // Note: If clear_interrupted==false, this simply fetches and
820 // returns the value of the field osthread()->interrupted().
821 return os::is_interrupted(thread, clear_interrupted);
822 }
825 // GC Support
826 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
827 jint thread_parity = _oops_do_parity;
828 if (thread_parity != strong_roots_parity) {
829 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
830 if (res == thread_parity) {
831 return true;
832 } else {
833 guarantee(res == strong_roots_parity, "Or else what?");
834 assert(SharedHeap::heap()->workers()->active_workers() > 0,
835 "Should only fail when parallel.");
836 return false;
837 }
838 }
839 assert(SharedHeap::heap()->workers()->active_workers() > 0,
840 "Should only fail when parallel.");
841 return false;
842 }
844 void Thread::oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf) {
845 active_handles()->oops_do(f);
846 // Do oop for ThreadShadow
847 f->do_oop((oop*)&_pending_exception);
848 handle_area()->oops_do(f);
849 }
851 void Thread::nmethods_do(CodeBlobClosure* cf) {
852 // no nmethods in a generic thread...
853 }
855 void Thread::metadata_do(void f(Metadata*)) {
856 if (metadata_handles() != NULL) {
857 for (int i = 0; i< metadata_handles()->length(); i++) {
858 f(metadata_handles()->at(i));
859 }
860 }
861 }
863 void Thread::print_on(outputStream* st) const {
864 // get_priority assumes osthread initialized
865 if (osthread() != NULL) {
866 int os_prio;
867 if (os::get_native_priority(this, &os_prio) == OS_OK) {
868 st->print("os_prio=%d ", os_prio);
869 }
870 st->print("tid=" INTPTR_FORMAT " ", this);
871 ext().print_on(st);
872 osthread()->print_on(st);
873 }
874 debug_only(if (WizardMode) print_owned_locks_on(st);)
875 }
877 // Thread::print_on_error() is called by fatal error handler. Don't use
878 // any lock or allocate memory.
879 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
880 if (is_VM_thread()) st->print("VMThread");
881 else if (is_Compiler_thread()) st->print("CompilerThread");
882 else if (is_Java_thread()) st->print("JavaThread");
883 else if (is_GC_task_thread()) st->print("GCTaskThread");
884 else if (is_Watcher_thread()) st->print("WatcherThread");
885 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
886 else st->print("Thread");
888 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
889 _stack_base - _stack_size, _stack_base);
891 if (osthread()) {
892 st->print(" [id=%d]", osthread()->thread_id());
893 }
894 }
896 #ifdef ASSERT
897 void Thread::print_owned_locks_on(outputStream* st) const {
898 Monitor *cur = _owned_locks;
899 if (cur == NULL) {
900 st->print(" (no locks) ");
901 } else {
902 st->print_cr(" Locks owned:");
903 while(cur) {
904 cur->print_on(st);
905 cur = cur->next();
906 }
907 }
908 }
910 static int ref_use_count = 0;
912 bool Thread::owns_locks_but_compiled_lock() const {
913 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
914 if (cur != Compile_lock) return true;
915 }
916 return false;
917 }
920 #endif
922 #ifndef PRODUCT
924 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
925 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
926 // no threads which allow_vm_block's are held
927 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
928 // Check if current thread is allowed to block at a safepoint
929 if (!(_allow_safepoint_count == 0))
930 fatal("Possible safepoint reached by thread that does not allow it");
931 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
932 fatal("LEAF method calling lock?");
933 }
935 #ifdef ASSERT
936 if (potential_vm_operation && is_Java_thread()
937 && !Universe::is_bootstrapping()) {
938 // Make sure we do not hold any locks that the VM thread also uses.
939 // This could potentially lead to deadlocks
940 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
941 // Threads_lock is special, since the safepoint synchronization will not start before this is
942 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
943 // since it is used to transfer control between JavaThreads and the VMThread
944 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
945 if ( (cur->allow_vm_block() &&
946 cur != Threads_lock &&
947 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
948 cur != VMOperationRequest_lock &&
949 cur != VMOperationQueue_lock) ||
950 cur->rank() == Mutex::special) {
951 fatal(err_msg("Thread holding lock at safepoint that vm can block on: %s", cur->name()));
952 }
953 }
954 }
956 if (GCALotAtAllSafepoints) {
957 // We could enter a safepoint here and thus have a gc
958 InterfaceSupport::check_gc_alot();
959 }
960 #endif
961 }
962 #endif
964 bool Thread::is_in_stack(address adr) const {
965 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
966 address end = os::current_stack_pointer();
967 // Allow non Java threads to call this without stack_base
968 if (_stack_base == NULL) return true;
969 if (stack_base() >= adr && adr >= end) return true;
971 return false;
972 }
975 bool Thread::is_in_usable_stack(address adr) const {
976 size_t stack_guard_size = os::uses_stack_guard_pages() ? (StackYellowPages + StackRedPages) * os::vm_page_size() : 0;
977 size_t usable_stack_size = _stack_size - stack_guard_size;
979 return ((adr < stack_base()) && (adr >= stack_base() - usable_stack_size));
980 }
983 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
984 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
985 // used for compilation in the future. If that change is made, the need for these methods
986 // should be revisited, and they should be removed if possible.
988 bool Thread::is_lock_owned(address adr) const {
989 return on_local_stack(adr);
990 }
992 bool Thread::set_as_starting_thread() {
993 // NOTE: this must be called inside the main thread.
994 return os::create_main_thread((JavaThread*)this);
995 }
997 static void initialize_class(Symbol* class_name, TRAPS) {
998 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
999 InstanceKlass::cast(klass)->initialize(CHECK);
1000 }
1003 // Creates the initial ThreadGroup
1004 static Handle create_initial_thread_group(TRAPS) {
1005 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
1006 instanceKlassHandle klass (THREAD, k);
1008 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
1009 {
1010 JavaValue result(T_VOID);
1011 JavaCalls::call_special(&result,
1012 system_instance,
1013 klass,
1014 vmSymbols::object_initializer_name(),
1015 vmSymbols::void_method_signature(),
1016 CHECK_NH);
1017 }
1018 Universe::set_system_thread_group(system_instance());
1020 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
1021 {
1022 JavaValue result(T_VOID);
1023 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
1024 JavaCalls::call_special(&result,
1025 main_instance,
1026 klass,
1027 vmSymbols::object_initializer_name(),
1028 vmSymbols::threadgroup_string_void_signature(),
1029 system_instance,
1030 string,
1031 CHECK_NH);
1032 }
1033 return main_instance;
1034 }
1036 // Creates the initial Thread
1037 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
1038 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
1039 instanceKlassHandle klass (THREAD, k);
1040 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
1042 java_lang_Thread::set_thread(thread_oop(), thread);
1043 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1044 thread->set_threadObj(thread_oop());
1046 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
1048 JavaValue result(T_VOID);
1049 JavaCalls::call_special(&result, thread_oop,
1050 klass,
1051 vmSymbols::object_initializer_name(),
1052 vmSymbols::threadgroup_string_void_signature(),
1053 thread_group,
1054 string,
1055 CHECK_NULL);
1056 return thread_oop();
1057 }
1059 static void call_initializeSystemClass(TRAPS) {
1060 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1061 instanceKlassHandle klass (THREAD, k);
1063 JavaValue result(T_VOID);
1064 JavaCalls::call_static(&result, klass, vmSymbols::initializeSystemClass_name(),
1065 vmSymbols::void_method_signature(), CHECK);
1066 }
1068 char java_runtime_name[128] = "";
1069 char java_runtime_version[128] = "";
1071 // extract the JRE name from sun.misc.Version.java_runtime_name
1072 static const char* get_java_runtime_name(TRAPS) {
1073 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1074 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1075 fieldDescriptor fd;
1076 bool found = k != NULL &&
1077 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(),
1078 vmSymbols::string_signature(), &fd);
1079 if (found) {
1080 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1081 if (name_oop == NULL)
1082 return NULL;
1083 const char* name = java_lang_String::as_utf8_string(name_oop,
1084 java_runtime_name,
1085 sizeof(java_runtime_name));
1086 return name;
1087 } else {
1088 return NULL;
1089 }
1090 }
1092 // extract the JRE version from sun.misc.Version.java_runtime_version
1093 static const char* get_java_runtime_version(TRAPS) {
1094 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1095 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1096 fieldDescriptor fd;
1097 bool found = k != NULL &&
1098 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_version_name(),
1099 vmSymbols::string_signature(), &fd);
1100 if (found) {
1101 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1102 if (name_oop == NULL)
1103 return NULL;
1104 const char* name = java_lang_String::as_utf8_string(name_oop,
1105 java_runtime_version,
1106 sizeof(java_runtime_version));
1107 return name;
1108 } else {
1109 return NULL;
1110 }
1111 }
1113 // General purpose hook into Java code, run once when the VM is initialized.
1114 // The Java library method itself may be changed independently from the VM.
1115 static void call_postVMInitHook(TRAPS) {
1116 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_PostVMInitHook(), THREAD);
1117 instanceKlassHandle klass (THREAD, k);
1118 if (klass.not_null()) {
1119 JavaValue result(T_VOID);
1120 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
1121 vmSymbols::void_method_signature(),
1122 CHECK);
1123 }
1124 }
1126 static void reset_vm_info_property(TRAPS) {
1127 // the vm info string
1128 ResourceMark rm(THREAD);
1129 const char *vm_info = VM_Version::vm_info_string();
1131 // java.lang.System class
1132 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1133 instanceKlassHandle klass (THREAD, k);
1135 // setProperty arguments
1136 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
1137 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
1139 // return value
1140 JavaValue r(T_OBJECT);
1142 // public static String setProperty(String key, String value);
1143 JavaCalls::call_static(&r,
1144 klass,
1145 vmSymbols::setProperty_name(),
1146 vmSymbols::string_string_string_signature(),
1147 key_str,
1148 value_str,
1149 CHECK);
1150 }
1153 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
1154 assert(thread_group.not_null(), "thread group should be specified");
1155 assert(threadObj() == NULL, "should only create Java thread object once");
1157 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
1158 instanceKlassHandle klass (THREAD, k);
1159 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
1161 java_lang_Thread::set_thread(thread_oop(), this);
1162 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1163 set_threadObj(thread_oop());
1165 JavaValue result(T_VOID);
1166 if (thread_name != NULL) {
1167 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
1168 // Thread gets assigned specified name and null target
1169 JavaCalls::call_special(&result,
1170 thread_oop,
1171 klass,
1172 vmSymbols::object_initializer_name(),
1173 vmSymbols::threadgroup_string_void_signature(),
1174 thread_group, // Argument 1
1175 name, // Argument 2
1176 THREAD);
1177 } else {
1178 // Thread gets assigned name "Thread-nnn" and null target
1179 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
1180 JavaCalls::call_special(&result,
1181 thread_oop,
1182 klass,
1183 vmSymbols::object_initializer_name(),
1184 vmSymbols::threadgroup_runnable_void_signature(),
1185 thread_group, // Argument 1
1186 Handle(), // Argument 2
1187 THREAD);
1188 }
1191 if (daemon) {
1192 java_lang_Thread::set_daemon(thread_oop());
1193 }
1195 if (HAS_PENDING_EXCEPTION) {
1196 return;
1197 }
1199 KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
1200 Handle threadObj(this, this->threadObj());
1202 JavaCalls::call_special(&result,
1203 thread_group,
1204 group,
1205 vmSymbols::add_method_name(),
1206 vmSymbols::thread_void_signature(),
1207 threadObj, // Arg 1
1208 THREAD);
1211 }
1213 // NamedThread -- non-JavaThread subclasses with multiple
1214 // uniquely named instances should derive from this.
1215 NamedThread::NamedThread() : Thread() {
1216 _name = NULL;
1217 _processed_thread = NULL;
1218 }
1220 NamedThread::~NamedThread() {
1221 if (_name != NULL) {
1222 FREE_C_HEAP_ARRAY(char, _name, mtThread);
1223 _name = NULL;
1224 }
1225 }
1227 void NamedThread::set_name(const char* format, ...) {
1228 guarantee(_name == NULL, "Only get to set name once.");
1229 _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);
1230 guarantee(_name != NULL, "alloc failure");
1231 va_list ap;
1232 va_start(ap, format);
1233 jio_vsnprintf(_name, max_name_len, format, ap);
1234 va_end(ap);
1235 }
1237 // ======= WatcherThread ========
1239 // The watcher thread exists to simulate timer interrupts. It should
1240 // be replaced by an abstraction over whatever native support for
1241 // timer interrupts exists on the platform.
1243 WatcherThread* WatcherThread::_watcher_thread = NULL;
1244 bool WatcherThread::_startable = false;
1245 volatile bool WatcherThread::_should_terminate = false;
1247 WatcherThread::WatcherThread() : Thread(), _crash_protection(NULL) {
1248 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1249 if (os::create_thread(this, os::watcher_thread)) {
1250 _watcher_thread = this;
1252 // Set the watcher thread to the highest OS priority which should not be
1253 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1254 // is created. The only normal thread using this priority is the reference
1255 // handler thread, which runs for very short intervals only.
1256 // If the VMThread's priority is not lower than the WatcherThread profiling
1257 // will be inaccurate.
1258 os::set_priority(this, MaxPriority);
1259 if (!DisableStartThread) {
1260 os::start_thread(this);
1261 }
1262 }
1263 }
1265 int WatcherThread::sleep() const {
1266 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1268 // remaining will be zero if there are no tasks,
1269 // causing the WatcherThread to sleep until a task is
1270 // enrolled
1271 int remaining = PeriodicTask::time_to_wait();
1272 int time_slept = 0;
1274 // we expect this to timeout - we only ever get unparked when
1275 // we should terminate or when a new task has been enrolled
1276 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1278 jlong time_before_loop = os::javaTimeNanos();
1280 for (;;) {
1281 bool timedout = PeriodicTask_lock->wait(Mutex::_no_safepoint_check_flag, remaining);
1282 jlong now = os::javaTimeNanos();
1284 if (remaining == 0) {
1285 // if we didn't have any tasks we could have waited for a long time
1286 // consider the time_slept zero and reset time_before_loop
1287 time_slept = 0;
1288 time_before_loop = now;
1289 } else {
1290 // need to recalulate since we might have new tasks in _tasks
1291 time_slept = (int) ((now - time_before_loop) / 1000000);
1292 }
1294 // Change to task list or spurious wakeup of some kind
1295 if (timedout || _should_terminate) {
1296 break;
1297 }
1299 remaining = PeriodicTask::time_to_wait();
1300 if (remaining == 0) {
1301 // Last task was just disenrolled so loop around and wait until
1302 // another task gets enrolled
1303 continue;
1304 }
1306 remaining -= time_slept;
1307 if (remaining <= 0)
1308 break;
1309 }
1311 return time_slept;
1312 }
1314 void WatcherThread::run() {
1315 assert(this == watcher_thread(), "just checking");
1317 this->record_stack_base_and_size();
1318 this->initialize_thread_local_storage();
1319 this->set_active_handles(JNIHandleBlock::allocate_block());
1320 while(!_should_terminate) {
1321 assert(watcher_thread() == Thread::current(), "thread consistency check");
1322 assert(watcher_thread() == this, "thread consistency check");
1324 // Calculate how long it'll be until the next PeriodicTask work
1325 // should be done, and sleep that amount of time.
1326 int time_waited = sleep();
1328 if (is_error_reported()) {
1329 // A fatal error has happened, the error handler(VMError::report_and_die)
1330 // should abort JVM after creating an error log file. However in some
1331 // rare cases, the error handler itself might deadlock. Here we try to
1332 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1333 //
1334 // This code is in WatcherThread because WatcherThread wakes up
1335 // periodically so the fatal error handler doesn't need to do anything;
1336 // also because the WatcherThread is less likely to crash than other
1337 // threads.
1339 for (;;) {
1340 if (!ShowMessageBoxOnError
1341 && (OnError == NULL || OnError[0] == '\0')
1342 && Arguments::abort_hook() == NULL) {
1343 os::sleep(this, 2 * 60 * 1000, false);
1344 fdStream err(defaultStream::output_fd());
1345 err.print_raw_cr("# [ timer expired, abort... ]");
1346 // skip atexit/vm_exit/vm_abort hooks
1347 os::die();
1348 }
1350 // Wake up 5 seconds later, the fatal handler may reset OnError or
1351 // ShowMessageBoxOnError when it is ready to abort.
1352 os::sleep(this, 5 * 1000, false);
1353 }
1354 }
1356 PeriodicTask::real_time_tick(time_waited);
1357 }
1359 // Signal that it is terminated
1360 {
1361 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1362 _watcher_thread = NULL;
1363 Terminator_lock->notify();
1364 }
1366 // Thread destructor usually does this..
1367 ThreadLocalStorage::set_thread(NULL);
1368 }
1370 void WatcherThread::start() {
1371 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1373 if (watcher_thread() == NULL && _startable) {
1374 _should_terminate = false;
1375 // Create the single instance of WatcherThread
1376 new WatcherThread();
1377 }
1378 }
1380 void WatcherThread::make_startable() {
1381 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1382 _startable = true;
1383 }
1385 void WatcherThread::stop() {
1386 {
1387 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1388 _should_terminate = true;
1389 OrderAccess::fence(); // ensure WatcherThread sees update in main loop
1391 WatcherThread* watcher = watcher_thread();
1392 if (watcher != NULL)
1393 watcher->unpark();
1394 }
1396 // it is ok to take late safepoints here, if needed
1397 MutexLocker mu(Terminator_lock);
1399 while(watcher_thread() != NULL) {
1400 // This wait should make safepoint checks, wait without a timeout,
1401 // and wait as a suspend-equivalent condition.
1402 //
1403 // Note: If the FlatProfiler is running, then this thread is waiting
1404 // for the WatcherThread to terminate and the WatcherThread, via the
1405 // FlatProfiler task, is waiting for the external suspend request on
1406 // this thread to complete. wait_for_ext_suspend_completion() will
1407 // eventually timeout, but that takes time. Making this wait a
1408 // suspend-equivalent condition solves that timeout problem.
1409 //
1410 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1411 Mutex::_as_suspend_equivalent_flag);
1412 }
1413 }
1415 void WatcherThread::unpark() {
1416 MutexLockerEx ml(PeriodicTask_lock->owned_by_self() ? NULL : PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1417 PeriodicTask_lock->notify();
1418 }
1420 void WatcherThread::print_on(outputStream* st) const {
1421 st->print("\"%s\" ", name());
1422 Thread::print_on(st);
1423 st->cr();
1424 }
1426 // ======= JavaThread ========
1428 // A JavaThread is a normal Java thread
1430 void JavaThread::initialize() {
1431 // Initialize fields
1433 // Set the claimed par_id to UINT_MAX (ie not claiming any par_ids)
1434 set_claimed_par_id(UINT_MAX);
1436 set_saved_exception_pc(NULL);
1437 set_threadObj(NULL);
1438 _anchor.clear();
1439 set_entry_point(NULL);
1440 set_jni_functions(jni_functions());
1441 set_callee_target(NULL);
1442 set_vm_result(NULL);
1443 set_vm_result_2(NULL);
1444 set_vframe_array_head(NULL);
1445 set_vframe_array_last(NULL);
1446 set_deferred_locals(NULL);
1447 set_deopt_mark(NULL);
1448 set_deopt_nmethod(NULL);
1449 clear_must_deopt_id();
1450 set_monitor_chunks(NULL);
1451 set_next(NULL);
1452 set_thread_state(_thread_new);
1453 _terminated = _not_terminated;
1454 _privileged_stack_top = NULL;
1455 _array_for_gc = NULL;
1456 _suspend_equivalent = false;
1457 _in_deopt_handler = 0;
1458 _doing_unsafe_access = false;
1459 _stack_guard_state = stack_guard_unused;
1460 (void)const_cast<oop&>(_exception_oop = NULL);
1461 _exception_pc = 0;
1462 _exception_handler_pc = 0;
1463 _is_method_handle_return = 0;
1464 _jvmti_thread_state= NULL;
1465 _should_post_on_exceptions_flag = JNI_FALSE;
1466 _jvmti_get_loaded_classes_closure = NULL;
1467 _interp_only_mode = 0;
1468 _special_runtime_exit_condition = _no_async_condition;
1469 _pending_async_exception = NULL;
1470 _thread_stat = NULL;
1471 _thread_stat = new ThreadStatistics();
1472 _blocked_on_compilation = false;
1473 _jni_active_critical = 0;
1474 _pending_jni_exception_check_fn = NULL;
1475 _do_not_unlock_if_synchronized = false;
1476 _cached_monitor_info = NULL;
1477 _parker = Parker::Allocate(this) ;
1479 #ifndef PRODUCT
1480 _jmp_ring_index = 0;
1481 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1482 record_jump(NULL, NULL, NULL, 0);
1483 }
1484 #endif /* PRODUCT */
1486 set_thread_profiler(NULL);
1487 if (FlatProfiler::is_active()) {
1488 // This is where we would decide to either give each thread it's own profiler
1489 // or use one global one from FlatProfiler,
1490 // or up to some count of the number of profiled threads, etc.
1491 ThreadProfiler* pp = new ThreadProfiler();
1492 pp->engage();
1493 set_thread_profiler(pp);
1494 }
1496 // Setup safepoint state info for this thread
1497 ThreadSafepointState::create(this);
1499 debug_only(_java_call_counter = 0);
1501 // JVMTI PopFrame support
1502 _popframe_condition = popframe_inactive;
1503 _popframe_preserved_args = NULL;
1504 _popframe_preserved_args_size = 0;
1505 _frames_to_pop_failed_realloc = 0;
1507 pd_initialize();
1508 }
1510 #if INCLUDE_ALL_GCS
1511 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1512 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1513 #endif // INCLUDE_ALL_GCS
1515 JavaThread::JavaThread(bool is_attaching_via_jni) :
1516 Thread()
1517 #if INCLUDE_ALL_GCS
1518 , _satb_mark_queue(&_satb_mark_queue_set),
1519 _dirty_card_queue(&_dirty_card_queue_set)
1520 #endif // INCLUDE_ALL_GCS
1521 {
1522 initialize();
1523 if (is_attaching_via_jni) {
1524 _jni_attach_state = _attaching_via_jni;
1525 } else {
1526 _jni_attach_state = _not_attaching_via_jni;
1527 }
1528 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
1529 }
1531 bool JavaThread::reguard_stack(address cur_sp) {
1532 if (_stack_guard_state != stack_guard_yellow_disabled) {
1533 return true; // Stack already guarded or guard pages not needed.
1534 }
1536 if (register_stack_overflow()) {
1537 // For those architectures which have separate register and
1538 // memory stacks, we must check the register stack to see if
1539 // it has overflowed.
1540 return false;
1541 }
1543 // Java code never executes within the yellow zone: the latter is only
1544 // there to provoke an exception during stack banging. If java code
1545 // is executing there, either StackShadowPages should be larger, or
1546 // some exception code in c1, c2 or the interpreter isn't unwinding
1547 // when it should.
1548 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1550 enable_stack_yellow_zone();
1551 return true;
1552 }
1554 bool JavaThread::reguard_stack(void) {
1555 return reguard_stack(os::current_stack_pointer());
1556 }
1559 void JavaThread::block_if_vm_exited() {
1560 if (_terminated == _vm_exited) {
1561 // _vm_exited is set at safepoint, and Threads_lock is never released
1562 // we will block here forever
1563 Threads_lock->lock_without_safepoint_check();
1564 ShouldNotReachHere();
1565 }
1566 }
1569 // Remove this ifdef when C1 is ported to the compiler interface.
1570 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1572 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1573 Thread()
1574 #if INCLUDE_ALL_GCS
1575 , _satb_mark_queue(&_satb_mark_queue_set),
1576 _dirty_card_queue(&_dirty_card_queue_set)
1577 #endif // INCLUDE_ALL_GCS
1578 {
1579 if (TraceThreadEvents) {
1580 tty->print_cr("creating thread %p", this);
1581 }
1582 initialize();
1583 _jni_attach_state = _not_attaching_via_jni;
1584 set_entry_point(entry_point);
1585 // Create the native thread itself.
1586 // %note runtime_23
1587 os::ThreadType thr_type = os::java_thread;
1588 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1589 os::java_thread;
1590 os::create_thread(this, thr_type, stack_sz);
1591 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1592 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1593 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1594 // the exception consists of creating the exception object & initializing it, initialization
1595 // will leave the VM via a JavaCall and then all locks must be unlocked).
1596 //
1597 // The thread is still suspended when we reach here. Thread must be explicit started
1598 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1599 // by calling Threads:add. The reason why this is not done here, is because the thread
1600 // object must be fully initialized (take a look at JVM_Start)
1601 }
1603 JavaThread::~JavaThread() {
1604 if (TraceThreadEvents) {
1605 tty->print_cr("terminate thread %p", this);
1606 }
1608 // JSR166 -- return the parker to the free list
1609 Parker::Release(_parker);
1610 _parker = NULL ;
1612 // Free any remaining previous UnrollBlock
1613 vframeArray* old_array = vframe_array_last();
1615 if (old_array != NULL) {
1616 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1617 old_array->set_unroll_block(NULL);
1618 delete old_info;
1619 delete old_array;
1620 }
1622 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1623 if (deferred != NULL) {
1624 // This can only happen if thread is destroyed before deoptimization occurs.
1625 assert(deferred->length() != 0, "empty array!");
1626 do {
1627 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1628 deferred->remove_at(0);
1629 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1630 delete dlv;
1631 } while (deferred->length() != 0);
1632 delete deferred;
1633 }
1635 // All Java related clean up happens in exit
1636 ThreadSafepointState::destroy(this);
1637 if (_thread_profiler != NULL) delete _thread_profiler;
1638 if (_thread_stat != NULL) delete _thread_stat;
1639 }
1642 // The first routine called by a new Java thread
1643 void JavaThread::run() {
1644 // initialize thread-local alloc buffer related fields
1645 this->initialize_tlab();
1647 // used to test validitity of stack trace backs
1648 this->record_base_of_stack_pointer();
1650 // Record real stack base and size.
1651 this->record_stack_base_and_size();
1653 // Initialize thread local storage; set before calling MutexLocker
1654 this->initialize_thread_local_storage();
1656 this->create_stack_guard_pages();
1658 this->cache_global_variables();
1660 // Thread is now sufficient initialized to be handled by the safepoint code as being
1661 // in the VM. Change thread state from _thread_new to _thread_in_vm
1662 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1664 assert(JavaThread::current() == this, "sanity check");
1665 assert(!Thread::current()->owns_locks(), "sanity check");
1667 DTRACE_THREAD_PROBE(start, this);
1669 // This operation might block. We call that after all safepoint checks for a new thread has
1670 // been completed.
1671 this->set_active_handles(JNIHandleBlock::allocate_block());
1673 if (JvmtiExport::should_post_thread_life()) {
1674 JvmtiExport::post_thread_start(this);
1675 }
1677 EventThreadStart event;
1678 if (event.should_commit()) {
1679 event.set_javalangthread(java_lang_Thread::thread_id(this->threadObj()));
1680 event.commit();
1681 }
1683 // We call another function to do the rest so we are sure that the stack addresses used
1684 // from there will be lower than the stack base just computed
1685 thread_main_inner();
1687 // Note, thread is no longer valid at this point!
1688 }
1691 void JavaThread::thread_main_inner() {
1692 assert(JavaThread::current() == this, "sanity check");
1693 assert(this->threadObj() != NULL, "just checking");
1695 // Execute thread entry point unless this thread has a pending exception
1696 // or has been stopped before starting.
1697 // Note: Due to JVM_StopThread we can have pending exceptions already!
1698 if (!this->has_pending_exception() &&
1699 !java_lang_Thread::is_stillborn(this->threadObj())) {
1700 {
1701 ResourceMark rm(this);
1702 this->set_native_thread_name(this->get_thread_name());
1703 }
1704 HandleMark hm(this);
1705 this->entry_point()(this, this);
1706 }
1708 DTRACE_THREAD_PROBE(stop, this);
1710 this->exit(false);
1711 delete this;
1712 }
1715 static void ensure_join(JavaThread* thread) {
1716 // We do not need to grap the Threads_lock, since we are operating on ourself.
1717 Handle threadObj(thread, thread->threadObj());
1718 assert(threadObj.not_null(), "java thread object must exist");
1719 ObjectLocker lock(threadObj, thread);
1720 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1721 thread->clear_pending_exception();
1722 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1723 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1724 // Clear the native thread instance - this makes isAlive return false and allows the join()
1725 // to complete once we've done the notify_all below
1726 java_lang_Thread::set_thread(threadObj(), NULL);
1727 lock.notify_all(thread);
1728 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1729 thread->clear_pending_exception();
1730 }
1733 // For any new cleanup additions, please check to see if they need to be applied to
1734 // cleanup_failed_attach_current_thread as well.
1735 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1736 assert(this == JavaThread::current(), "thread consistency check");
1738 HandleMark hm(this);
1739 Handle uncaught_exception(this, this->pending_exception());
1740 this->clear_pending_exception();
1741 Handle threadObj(this, this->threadObj());
1742 assert(threadObj.not_null(), "Java thread object should be created");
1744 if (get_thread_profiler() != NULL) {
1745 get_thread_profiler()->disengage();
1746 ResourceMark rm;
1747 get_thread_profiler()->print(get_thread_name());
1748 }
1751 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1752 {
1753 EXCEPTION_MARK;
1755 CLEAR_PENDING_EXCEPTION;
1756 }
1757 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1758 // has to be fixed by a runtime query method
1759 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1760 // JSR-166: change call from from ThreadGroup.uncaughtException to
1761 // java.lang.Thread.dispatchUncaughtException
1762 if (uncaught_exception.not_null()) {
1763 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1764 {
1765 EXCEPTION_MARK;
1766 // Check if the method Thread.dispatchUncaughtException() exists. If so
1767 // call it. Otherwise we have an older library without the JSR-166 changes,
1768 // so call ThreadGroup.uncaughtException()
1769 KlassHandle recvrKlass(THREAD, threadObj->klass());
1770 CallInfo callinfo;
1771 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1772 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1773 vmSymbols::dispatchUncaughtException_name(),
1774 vmSymbols::throwable_void_signature(),
1775 KlassHandle(), false, false, THREAD);
1776 CLEAR_PENDING_EXCEPTION;
1777 methodHandle method = callinfo.selected_method();
1778 if (method.not_null()) {
1779 JavaValue result(T_VOID);
1780 JavaCalls::call_virtual(&result,
1781 threadObj, thread_klass,
1782 vmSymbols::dispatchUncaughtException_name(),
1783 vmSymbols::throwable_void_signature(),
1784 uncaught_exception,
1785 THREAD);
1786 } else {
1787 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1788 JavaValue result(T_VOID);
1789 JavaCalls::call_virtual(&result,
1790 group, thread_group,
1791 vmSymbols::uncaughtException_name(),
1792 vmSymbols::thread_throwable_void_signature(),
1793 threadObj, // Arg 1
1794 uncaught_exception, // Arg 2
1795 THREAD);
1796 }
1797 if (HAS_PENDING_EXCEPTION) {
1798 ResourceMark rm(this);
1799 jio_fprintf(defaultStream::error_stream(),
1800 "\nException: %s thrown from the UncaughtExceptionHandler"
1801 " in thread \"%s\"\n",
1802 pending_exception()->klass()->external_name(),
1803 get_thread_name());
1804 CLEAR_PENDING_EXCEPTION;
1805 }
1806 }
1807 }
1809 // Called before the java thread exit since we want to read info
1810 // from java_lang_Thread object
1811 EventThreadEnd event;
1812 if (event.should_commit()) {
1813 event.set_javalangthread(java_lang_Thread::thread_id(this->threadObj()));
1814 event.commit();
1815 }
1817 // Call after last event on thread
1818 EVENT_THREAD_EXIT(this);
1820 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1821 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1822 // is deprecated anyhow.
1823 if (!is_Compiler_thread()) {
1824 int count = 3;
1825 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1826 EXCEPTION_MARK;
1827 JavaValue result(T_VOID);
1828 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1829 JavaCalls::call_virtual(&result,
1830 threadObj, thread_klass,
1831 vmSymbols::exit_method_name(),
1832 vmSymbols::void_method_signature(),
1833 THREAD);
1834 CLEAR_PENDING_EXCEPTION;
1835 }
1836 }
1837 // notify JVMTI
1838 if (JvmtiExport::should_post_thread_life()) {
1839 JvmtiExport::post_thread_end(this);
1840 }
1842 // We have notified the agents that we are exiting, before we go on,
1843 // we must check for a pending external suspend request and honor it
1844 // in order to not surprise the thread that made the suspend request.
1845 while (true) {
1846 {
1847 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1848 if (!is_external_suspend()) {
1849 set_terminated(_thread_exiting);
1850 ThreadService::current_thread_exiting(this);
1851 break;
1852 }
1853 // Implied else:
1854 // Things get a little tricky here. We have a pending external
1855 // suspend request, but we are holding the SR_lock so we
1856 // can't just self-suspend. So we temporarily drop the lock
1857 // and then self-suspend.
1858 }
1860 ThreadBlockInVM tbivm(this);
1861 java_suspend_self();
1863 // We're done with this suspend request, but we have to loop around
1864 // and check again. Eventually we will get SR_lock without a pending
1865 // external suspend request and will be able to mark ourselves as
1866 // exiting.
1867 }
1868 // no more external suspends are allowed at this point
1869 } else {
1870 // before_exit() has already posted JVMTI THREAD_END events
1871 }
1873 // Notify waiters on thread object. This has to be done after exit() is called
1874 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1875 // group should have the destroyed bit set before waiters are notified).
1876 ensure_join(this);
1877 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1879 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1880 // held by this thread must be released. A detach operation must only
1881 // get here if there are no Java frames on the stack. Therefore, any
1882 // owned monitors at this point MUST be JNI-acquired monitors which are
1883 // pre-inflated and in the monitor cache.
1884 //
1885 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1886 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1887 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1888 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1889 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1890 }
1892 // These things needs to be done while we are still a Java Thread. Make sure that thread
1893 // is in a consistent state, in case GC happens
1894 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1896 if (active_handles() != NULL) {
1897 JNIHandleBlock* block = active_handles();
1898 set_active_handles(NULL);
1899 JNIHandleBlock::release_block(block);
1900 }
1902 if (free_handle_block() != NULL) {
1903 JNIHandleBlock* block = free_handle_block();
1904 set_free_handle_block(NULL);
1905 JNIHandleBlock::release_block(block);
1906 }
1908 // These have to be removed while this is still a valid thread.
1909 remove_stack_guard_pages();
1911 if (UseTLAB) {
1912 tlab().make_parsable(true); // retire TLAB
1913 }
1915 if (JvmtiEnv::environments_might_exist()) {
1916 JvmtiExport::cleanup_thread(this);
1917 }
1919 // We must flush any deferred card marks before removing a thread from
1920 // the list of active threads.
1921 Universe::heap()->flush_deferred_store_barrier(this);
1922 assert(deferred_card_mark().is_empty(), "Should have been flushed");
1924 #if INCLUDE_ALL_GCS
1925 // We must flush the G1-related buffers before removing a thread
1926 // from the list of active threads. We must do this after any deferred
1927 // card marks have been flushed (above) so that any entries that are
1928 // added to the thread's dirty card queue as a result are not lost.
1929 if (UseG1GC) {
1930 flush_barrier_queues();
1931 }
1932 #endif // INCLUDE_ALL_GCS
1934 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1935 Threads::remove(this);
1936 }
1938 #if INCLUDE_ALL_GCS
1939 // Flush G1-related queues.
1940 void JavaThread::flush_barrier_queues() {
1941 satb_mark_queue().flush();
1942 dirty_card_queue().flush();
1943 }
1945 void JavaThread::initialize_queues() {
1946 assert(!SafepointSynchronize::is_at_safepoint(),
1947 "we should not be at a safepoint");
1949 ObjPtrQueue& satb_queue = satb_mark_queue();
1950 SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
1951 // The SATB queue should have been constructed with its active
1952 // field set to false.
1953 assert(!satb_queue.is_active(), "SATB queue should not be active");
1954 assert(satb_queue.is_empty(), "SATB queue should be empty");
1955 // If we are creating the thread during a marking cycle, we should
1956 // set the active field of the SATB queue to true.
1957 if (satb_queue_set.is_active()) {
1958 satb_queue.set_active(true);
1959 }
1961 DirtyCardQueue& dirty_queue = dirty_card_queue();
1962 // The dirty card queue should have been constructed with its
1963 // active field set to true.
1964 assert(dirty_queue.is_active(), "dirty card queue should be active");
1965 }
1966 #endif // INCLUDE_ALL_GCS
1968 void JavaThread::cleanup_failed_attach_current_thread() {
1969 if (get_thread_profiler() != NULL) {
1970 get_thread_profiler()->disengage();
1971 ResourceMark rm;
1972 get_thread_profiler()->print(get_thread_name());
1973 }
1975 if (active_handles() != NULL) {
1976 JNIHandleBlock* block = active_handles();
1977 set_active_handles(NULL);
1978 JNIHandleBlock::release_block(block);
1979 }
1981 if (free_handle_block() != NULL) {
1982 JNIHandleBlock* block = free_handle_block();
1983 set_free_handle_block(NULL);
1984 JNIHandleBlock::release_block(block);
1985 }
1987 // These have to be removed while this is still a valid thread.
1988 remove_stack_guard_pages();
1990 if (UseTLAB) {
1991 tlab().make_parsable(true); // retire TLAB, if any
1992 }
1994 #if INCLUDE_ALL_GCS
1995 if (UseG1GC) {
1996 flush_barrier_queues();
1997 }
1998 #endif // INCLUDE_ALL_GCS
2000 Threads::remove(this);
2001 delete this;
2002 }
2007 JavaThread* JavaThread::active() {
2008 Thread* thread = ThreadLocalStorage::thread();
2009 assert(thread != NULL, "just checking");
2010 if (thread->is_Java_thread()) {
2011 return (JavaThread*) thread;
2012 } else {
2013 assert(thread->is_VM_thread(), "this must be a vm thread");
2014 VM_Operation* op = ((VMThread*) thread)->vm_operation();
2015 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
2016 assert(ret->is_Java_thread(), "must be a Java thread");
2017 return ret;
2018 }
2019 }
2021 bool JavaThread::is_lock_owned(address adr) const {
2022 if (Thread::is_lock_owned(adr)) return true;
2024 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2025 if (chunk->contains(adr)) return true;
2026 }
2028 return false;
2029 }
2032 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
2033 chunk->set_next(monitor_chunks());
2034 set_monitor_chunks(chunk);
2035 }
2037 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
2038 guarantee(monitor_chunks() != NULL, "must be non empty");
2039 if (monitor_chunks() == chunk) {
2040 set_monitor_chunks(chunk->next());
2041 } else {
2042 MonitorChunk* prev = monitor_chunks();
2043 while (prev->next() != chunk) prev = prev->next();
2044 prev->set_next(chunk->next());
2045 }
2046 }
2048 // JVM support.
2050 // Note: this function shouldn't block if it's called in
2051 // _thread_in_native_trans state (such as from
2052 // check_special_condition_for_native_trans()).
2053 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
2055 if (has_last_Java_frame() && has_async_condition()) {
2056 // If we are at a polling page safepoint (not a poll return)
2057 // then we must defer async exception because live registers
2058 // will be clobbered by the exception path. Poll return is
2059 // ok because the call we a returning from already collides
2060 // with exception handling registers and so there is no issue.
2061 // (The exception handling path kills call result registers but
2062 // this is ok since the exception kills the result anyway).
2064 if (is_at_poll_safepoint()) {
2065 // if the code we are returning to has deoptimized we must defer
2066 // the exception otherwise live registers get clobbered on the
2067 // exception path before deoptimization is able to retrieve them.
2068 //
2069 RegisterMap map(this, false);
2070 frame caller_fr = last_frame().sender(&map);
2071 assert(caller_fr.is_compiled_frame(), "what?");
2072 if (caller_fr.is_deoptimized_frame()) {
2073 if (TraceExceptions) {
2074 ResourceMark rm;
2075 tty->print_cr("deferred async exception at compiled safepoint");
2076 }
2077 return;
2078 }
2079 }
2080 }
2082 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
2083 if (condition == _no_async_condition) {
2084 // Conditions have changed since has_special_runtime_exit_condition()
2085 // was called:
2086 // - if we were here only because of an external suspend request,
2087 // then that was taken care of above (or cancelled) so we are done
2088 // - if we were here because of another async request, then it has
2089 // been cleared between the has_special_runtime_exit_condition()
2090 // and now so again we are done
2091 return;
2092 }
2094 // Check for pending async. exception
2095 if (_pending_async_exception != NULL) {
2096 // Only overwrite an already pending exception, if it is not a threadDeath.
2097 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
2099 // We cannot call Exceptions::_throw(...) here because we cannot block
2100 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
2102 if (TraceExceptions) {
2103 ResourceMark rm;
2104 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
2105 if (has_last_Java_frame() ) {
2106 frame f = last_frame();
2107 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
2108 }
2109 tty->print_cr(" of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2110 }
2111 _pending_async_exception = NULL;
2112 clear_has_async_exception();
2113 }
2114 }
2116 if (check_unsafe_error &&
2117 condition == _async_unsafe_access_error && !has_pending_exception()) {
2118 condition = _no_async_condition; // done
2119 switch (thread_state()) {
2120 case _thread_in_vm:
2121 {
2122 JavaThread* THREAD = this;
2123 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2124 }
2125 case _thread_in_native:
2126 {
2127 ThreadInVMfromNative tiv(this);
2128 JavaThread* THREAD = this;
2129 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2130 }
2131 case _thread_in_Java:
2132 {
2133 ThreadInVMfromJava tiv(this);
2134 JavaThread* THREAD = this;
2135 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
2136 }
2137 default:
2138 ShouldNotReachHere();
2139 }
2140 }
2142 assert(condition == _no_async_condition || has_pending_exception() ||
2143 (!check_unsafe_error && condition == _async_unsafe_access_error),
2144 "must have handled the async condition, if no exception");
2145 }
2147 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
2148 //
2149 // Check for pending external suspend. Internal suspend requests do
2150 // not use handle_special_runtime_exit_condition().
2151 // If JNIEnv proxies are allowed, don't self-suspend if the target
2152 // thread is not the current thread. In older versions of jdbx, jdbx
2153 // threads could call into the VM with another thread's JNIEnv so we
2154 // can be here operating on behalf of a suspended thread (4432884).
2155 bool do_self_suspend = is_external_suspend_with_lock();
2156 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
2157 //
2158 // Because thread is external suspended the safepoint code will count
2159 // thread as at a safepoint. This can be odd because we can be here
2160 // as _thread_in_Java which would normally transition to _thread_blocked
2161 // at a safepoint. We would like to mark the thread as _thread_blocked
2162 // before calling java_suspend_self like all other callers of it but
2163 // we must then observe proper safepoint protocol. (We can't leave
2164 // _thread_blocked with a safepoint in progress). However we can be
2165 // here as _thread_in_native_trans so we can't use a normal transition
2166 // constructor/destructor pair because they assert on that type of
2167 // transition. We could do something like:
2168 //
2169 // JavaThreadState state = thread_state();
2170 // set_thread_state(_thread_in_vm);
2171 // {
2172 // ThreadBlockInVM tbivm(this);
2173 // java_suspend_self()
2174 // }
2175 // set_thread_state(_thread_in_vm_trans);
2176 // if (safepoint) block;
2177 // set_thread_state(state);
2178 //
2179 // but that is pretty messy. Instead we just go with the way the
2180 // code has worked before and note that this is the only path to
2181 // java_suspend_self that doesn't put the thread in _thread_blocked
2182 // mode.
2184 frame_anchor()->make_walkable(this);
2185 java_suspend_self();
2187 // We might be here for reasons in addition to the self-suspend request
2188 // so check for other async requests.
2189 }
2191 if (check_asyncs) {
2192 check_and_handle_async_exceptions();
2193 }
2194 }
2196 void JavaThread::send_thread_stop(oop java_throwable) {
2197 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
2198 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
2199 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
2201 // Do not throw asynchronous exceptions against the compiler thread
2202 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
2203 if (is_Compiler_thread()) return;
2205 {
2206 // Actually throw the Throwable against the target Thread - however
2207 // only if there is no thread death exception installed already.
2208 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
2209 // If the topmost frame is a runtime stub, then we are calling into
2210 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
2211 // must deoptimize the caller before continuing, as the compiled exception handler table
2212 // may not be valid
2213 if (has_last_Java_frame()) {
2214 frame f = last_frame();
2215 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
2216 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2217 RegisterMap reg_map(this, UseBiasedLocking);
2218 frame compiled_frame = f.sender(®_map);
2219 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
2220 Deoptimization::deoptimize(this, compiled_frame, ®_map);
2221 }
2222 }
2223 }
2225 // Set async. pending exception in thread.
2226 set_pending_async_exception(java_throwable);
2228 if (TraceExceptions) {
2229 ResourceMark rm;
2230 tty->print_cr("Pending Async. exception installed of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2231 }
2232 // for AbortVMOnException flag
2233 NOT_PRODUCT(Exceptions::debug_check_abort(InstanceKlass::cast(_pending_async_exception->klass())->external_name()));
2234 }
2235 }
2238 // Interrupt thread so it will wake up from a potential wait()
2239 Thread::interrupt(this);
2240 }
2242 // External suspension mechanism.
2243 //
2244 // Tell the VM to suspend a thread when ever it knows that it does not hold on
2245 // to any VM_locks and it is at a transition
2246 // Self-suspension will happen on the transition out of the vm.
2247 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
2248 //
2249 // Guarantees on return:
2250 // + Target thread will not execute any new bytecode (that's why we need to
2251 // force a safepoint)
2252 // + Target thread will not enter any new monitors
2253 //
2254 void JavaThread::java_suspend() {
2255 { MutexLocker mu(Threads_lock);
2256 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
2257 return;
2258 }
2259 }
2261 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2262 if (!is_external_suspend()) {
2263 // a racing resume has cancelled us; bail out now
2264 return;
2265 }
2267 // suspend is done
2268 uint32_t debug_bits = 0;
2269 // Warning: is_ext_suspend_completed() may temporarily drop the
2270 // SR_lock to allow the thread to reach a stable thread state if
2271 // it is currently in a transient thread state.
2272 if (is_ext_suspend_completed(false /* !called_by_wait */,
2273 SuspendRetryDelay, &debug_bits) ) {
2274 return;
2275 }
2276 }
2278 VM_ForceSafepoint vm_suspend;
2279 VMThread::execute(&vm_suspend);
2280 }
2282 // Part II of external suspension.
2283 // A JavaThread self suspends when it detects a pending external suspend
2284 // request. This is usually on transitions. It is also done in places
2285 // where continuing to the next transition would surprise the caller,
2286 // e.g., monitor entry.
2287 //
2288 // Returns the number of times that the thread self-suspended.
2289 //
2290 // Note: DO NOT call java_suspend_self() when you just want to block current
2291 // thread. java_suspend_self() is the second stage of cooperative
2292 // suspension for external suspend requests and should only be used
2293 // to complete an external suspend request.
2294 //
2295 int JavaThread::java_suspend_self() {
2296 int ret = 0;
2298 // we are in the process of exiting so don't suspend
2299 if (is_exiting()) {
2300 clear_external_suspend();
2301 return ret;
2302 }
2304 assert(_anchor.walkable() ||
2305 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
2306 "must have walkable stack");
2308 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2310 assert(!this->is_ext_suspended(),
2311 "a thread trying to self-suspend should not already be suspended");
2313 if (this->is_suspend_equivalent()) {
2314 // If we are self-suspending as a result of the lifting of a
2315 // suspend equivalent condition, then the suspend_equivalent
2316 // flag is not cleared until we set the ext_suspended flag so
2317 // that wait_for_ext_suspend_completion() returns consistent
2318 // results.
2319 this->clear_suspend_equivalent();
2320 }
2322 // A racing resume may have cancelled us before we grabbed SR_lock
2323 // above. Or another external suspend request could be waiting for us
2324 // by the time we return from SR_lock()->wait(). The thread
2325 // that requested the suspension may already be trying to walk our
2326 // stack and if we return now, we can change the stack out from under
2327 // it. This would be a "bad thing (TM)" and cause the stack walker
2328 // to crash. We stay self-suspended until there are no more pending
2329 // external suspend requests.
2330 while (is_external_suspend()) {
2331 ret++;
2332 this->set_ext_suspended();
2334 // _ext_suspended flag is cleared by java_resume()
2335 while (is_ext_suspended()) {
2336 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2337 }
2338 }
2340 return ret;
2341 }
2343 #ifdef ASSERT
2344 // verify the JavaThread has not yet been published in the Threads::list, and
2345 // hence doesn't need protection from concurrent access at this stage
2346 void JavaThread::verify_not_published() {
2347 if (!Threads_lock->owned_by_self()) {
2348 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2349 assert( !Threads::includes(this),
2350 "java thread shouldn't have been published yet!");
2351 }
2352 else {
2353 assert( !Threads::includes(this),
2354 "java thread shouldn't have been published yet!");
2355 }
2356 }
2357 #endif
2359 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2360 // progress or when _suspend_flags is non-zero.
2361 // Current thread needs to self-suspend if there is a suspend request and/or
2362 // block if a safepoint is in progress.
2363 // Async exception ISN'T checked.
2364 // Note only the ThreadInVMfromNative transition can call this function
2365 // directly and when thread state is _thread_in_native_trans
2366 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2367 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2369 JavaThread *curJT = JavaThread::current();
2370 bool do_self_suspend = thread->is_external_suspend();
2372 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2374 // If JNIEnv proxies are allowed, don't self-suspend if the target
2375 // thread is not the current thread. In older versions of jdbx, jdbx
2376 // threads could call into the VM with another thread's JNIEnv so we
2377 // can be here operating on behalf of a suspended thread (4432884).
2378 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2379 JavaThreadState state = thread->thread_state();
2381 // We mark this thread_blocked state as a suspend-equivalent so
2382 // that a caller to is_ext_suspend_completed() won't be confused.
2383 // The suspend-equivalent state is cleared by java_suspend_self().
2384 thread->set_suspend_equivalent();
2386 // If the safepoint code sees the _thread_in_native_trans state, it will
2387 // wait until the thread changes to other thread state. There is no
2388 // guarantee on how soon we can obtain the SR_lock and complete the
2389 // self-suspend request. It would be a bad idea to let safepoint wait for
2390 // too long. Temporarily change the state to _thread_blocked to
2391 // let the VM thread know that this thread is ready for GC. The problem
2392 // of changing thread state is that safepoint could happen just after
2393 // java_suspend_self() returns after being resumed, and VM thread will
2394 // see the _thread_blocked state. We must check for safepoint
2395 // after restoring the state and make sure we won't leave while a safepoint
2396 // is in progress.
2397 thread->set_thread_state(_thread_blocked);
2398 thread->java_suspend_self();
2399 thread->set_thread_state(state);
2400 // Make sure new state is seen by VM thread
2401 if (os::is_MP()) {
2402 if (UseMembar) {
2403 // Force a fence between the write above and read below
2404 OrderAccess::fence();
2405 } else {
2406 // Must use this rather than serialization page in particular on Windows
2407 InterfaceSupport::serialize_memory(thread);
2408 }
2409 }
2410 }
2412 if (SafepointSynchronize::do_call_back()) {
2413 // If we are safepointing, then block the caller which may not be
2414 // the same as the target thread (see above).
2415 SafepointSynchronize::block(curJT);
2416 }
2418 if (thread->is_deopt_suspend()) {
2419 thread->clear_deopt_suspend();
2420 RegisterMap map(thread, false);
2421 frame f = thread->last_frame();
2422 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2423 f = f.sender(&map);
2424 }
2425 if (f.id() == thread->must_deopt_id()) {
2426 thread->clear_must_deopt_id();
2427 f.deoptimize(thread);
2428 } else {
2429 fatal("missed deoptimization!");
2430 }
2431 }
2432 }
2434 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2435 // progress or when _suspend_flags is non-zero.
2436 // Current thread needs to self-suspend if there is a suspend request and/or
2437 // block if a safepoint is in progress.
2438 // Also check for pending async exception (not including unsafe access error).
2439 // Note only the native==>VM/Java barriers can call this function and when
2440 // thread state is _thread_in_native_trans.
2441 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2442 check_safepoint_and_suspend_for_native_trans(thread);
2444 if (thread->has_async_exception()) {
2445 // We are in _thread_in_native_trans state, don't handle unsafe
2446 // access error since that may block.
2447 thread->check_and_handle_async_exceptions(false);
2448 }
2449 }
2451 // This is a variant of the normal
2452 // check_special_condition_for_native_trans with slightly different
2453 // semantics for use by critical native wrappers. It does all the
2454 // normal checks but also performs the transition back into
2455 // thread_in_Java state. This is required so that critical natives
2456 // can potentially block and perform a GC if they are the last thread
2457 // exiting the GC_locker.
2458 void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) {
2459 check_special_condition_for_native_trans(thread);
2461 // Finish the transition
2462 thread->set_thread_state(_thread_in_Java);
2464 if (thread->do_critical_native_unlock()) {
2465 ThreadInVMfromJavaNoAsyncException tiv(thread);
2466 GC_locker::unlock_critical(thread);
2467 thread->clear_critical_native_unlock();
2468 }
2469 }
2471 // We need to guarantee the Threads_lock here, since resumes are not
2472 // allowed during safepoint synchronization
2473 // Can only resume from an external suspension
2474 void JavaThread::java_resume() {
2475 assert_locked_or_safepoint(Threads_lock);
2477 // Sanity check: thread is gone, has started exiting or the thread
2478 // was not externally suspended.
2479 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2480 return;
2481 }
2483 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2485 clear_external_suspend();
2487 if (is_ext_suspended()) {
2488 clear_ext_suspended();
2489 SR_lock()->notify_all();
2490 }
2491 }
2493 void JavaThread::create_stack_guard_pages() {
2494 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2495 address low_addr = stack_base() - stack_size();
2496 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2498 int allocate = os::allocate_stack_guard_pages();
2499 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2501 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
2502 warning("Attempt to allocate stack guard pages failed.");
2503 return;
2504 }
2506 if (os::guard_memory((char *) low_addr, len)) {
2507 _stack_guard_state = stack_guard_enabled;
2508 } else {
2509 warning("Attempt to protect stack guard pages failed.");
2510 if (os::uncommit_memory((char *) low_addr, len)) {
2511 warning("Attempt to deallocate stack guard pages failed.");
2512 }
2513 }
2514 }
2516 void JavaThread::remove_stack_guard_pages() {
2517 assert(Thread::current() == this, "from different thread");
2518 if (_stack_guard_state == stack_guard_unused) return;
2519 address low_addr = stack_base() - stack_size();
2520 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2522 if (os::allocate_stack_guard_pages()) {
2523 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2524 _stack_guard_state = stack_guard_unused;
2525 } else {
2526 warning("Attempt to deallocate stack guard pages failed.");
2527 }
2528 } else {
2529 if (_stack_guard_state == stack_guard_unused) return;
2530 if (os::unguard_memory((char *) low_addr, len)) {
2531 _stack_guard_state = stack_guard_unused;
2532 } else {
2533 warning("Attempt to unprotect stack guard pages failed.");
2534 }
2535 }
2536 }
2538 void JavaThread::enable_stack_yellow_zone() {
2539 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2540 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2542 // The base notation is from the stacks point of view, growing downward.
2543 // We need to adjust it to work correctly with guard_memory()
2544 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2546 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2547 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2549 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2550 _stack_guard_state = stack_guard_enabled;
2551 } else {
2552 warning("Attempt to guard stack yellow zone failed.");
2553 }
2554 enable_register_stack_guard();
2555 }
2557 void JavaThread::disable_stack_yellow_zone() {
2558 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2559 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2561 // Simply return if called for a thread that does not use guard pages.
2562 if (_stack_guard_state == stack_guard_unused) return;
2564 // The base notation is from the stacks point of view, growing downward.
2565 // We need to adjust it to work correctly with guard_memory()
2566 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2568 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2569 _stack_guard_state = stack_guard_yellow_disabled;
2570 } else {
2571 warning("Attempt to unguard stack yellow zone failed.");
2572 }
2573 disable_register_stack_guard();
2574 }
2576 void JavaThread::enable_stack_red_zone() {
2577 // The base notation is from the stacks point of view, growing downward.
2578 // We need to adjust it to work correctly with guard_memory()
2579 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2580 address base = stack_red_zone_base() - stack_red_zone_size();
2582 guarantee(base < stack_base(),"Error calculating stack red zone");
2583 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2585 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2586 warning("Attempt to guard stack red zone failed.");
2587 }
2588 }
2590 void JavaThread::disable_stack_red_zone() {
2591 // The base notation is from the stacks point of view, growing downward.
2592 // We need to adjust it to work correctly with guard_memory()
2593 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2594 address base = stack_red_zone_base() - stack_red_zone_size();
2595 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2596 warning("Attempt to unguard stack red zone failed.");
2597 }
2598 }
2600 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2601 // ignore is there is no stack
2602 if (!has_last_Java_frame()) return;
2603 // traverse the stack frames. Starts from top frame.
2604 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2605 frame* fr = fst.current();
2606 f(fr, fst.register_map());
2607 }
2608 }
2611 #ifndef PRODUCT
2612 // Deoptimization
2613 // Function for testing deoptimization
2614 void JavaThread::deoptimize() {
2615 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2616 StackFrameStream fst(this, UseBiasedLocking);
2617 bool deopt = false; // Dump stack only if a deopt actually happens.
2618 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2619 // Iterate over all frames in the thread and deoptimize
2620 for(; !fst.is_done(); fst.next()) {
2621 if(fst.current()->can_be_deoptimized()) {
2623 if (only_at) {
2624 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2625 // consists of comma or carriage return separated numbers so
2626 // search for the current bci in that string.
2627 address pc = fst.current()->pc();
2628 nmethod* nm = (nmethod*) fst.current()->cb();
2629 ScopeDesc* sd = nm->scope_desc_at( pc);
2630 char buffer[8];
2631 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2632 size_t len = strlen(buffer);
2633 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2634 while (found != NULL) {
2635 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2636 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2637 // Check that the bci found is bracketed by terminators.
2638 break;
2639 }
2640 found = strstr(found + 1, buffer);
2641 }
2642 if (!found) {
2643 continue;
2644 }
2645 }
2647 if (DebugDeoptimization && !deopt) {
2648 deopt = true; // One-time only print before deopt
2649 tty->print_cr("[BEFORE Deoptimization]");
2650 trace_frames();
2651 trace_stack();
2652 }
2653 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2654 }
2655 }
2657 if (DebugDeoptimization && deopt) {
2658 tty->print_cr("[AFTER Deoptimization]");
2659 trace_frames();
2660 }
2661 }
2664 // Make zombies
2665 void JavaThread::make_zombies() {
2666 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2667 if (fst.current()->can_be_deoptimized()) {
2668 // it is a Java nmethod
2669 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2670 nm->make_not_entrant();
2671 }
2672 }
2673 }
2674 #endif // PRODUCT
2677 void JavaThread::deoptimized_wrt_marked_nmethods() {
2678 if (!has_last_Java_frame()) return;
2679 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2680 StackFrameStream fst(this, UseBiasedLocking);
2681 for(; !fst.is_done(); fst.next()) {
2682 if (fst.current()->should_be_deoptimized()) {
2683 if (LogCompilation && xtty != NULL) {
2684 nmethod* nm = fst.current()->cb()->as_nmethod_or_null();
2685 xtty->elem("deoptimized thread='" UINTX_FORMAT "' compile_id='%d'",
2686 this->name(), nm != NULL ? nm->compile_id() : -1);
2687 }
2689 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2690 }
2691 }
2692 }
2695 // GC support
2696 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2698 void JavaThread::gc_epilogue() {
2699 frames_do(frame_gc_epilogue);
2700 }
2703 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2705 void JavaThread::gc_prologue() {
2706 frames_do(frame_gc_prologue);
2707 }
2709 // If the caller is a NamedThread, then remember, in the current scope,
2710 // the given JavaThread in its _processed_thread field.
2711 class RememberProcessedThread: public StackObj {
2712 NamedThread* _cur_thr;
2713 public:
2714 RememberProcessedThread(JavaThread* jthr) {
2715 Thread* thread = Thread::current();
2716 if (thread->is_Named_thread()) {
2717 _cur_thr = (NamedThread *)thread;
2718 _cur_thr->set_processed_thread(jthr);
2719 } else {
2720 _cur_thr = NULL;
2721 }
2722 }
2724 ~RememberProcessedThread() {
2725 if (_cur_thr) {
2726 _cur_thr->set_processed_thread(NULL);
2727 }
2728 }
2729 };
2731 void JavaThread::oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf) {
2732 // Verify that the deferred card marks have been flushed.
2733 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2735 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2736 // since there may be more than one thread using each ThreadProfiler.
2738 // Traverse the GCHandles
2739 Thread::oops_do(f, cld_f, cf);
2741 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2742 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2744 if (has_last_Java_frame()) {
2745 // Record JavaThread to GC thread
2746 RememberProcessedThread rpt(this);
2748 // Traverse the privileged stack
2749 if (_privileged_stack_top != NULL) {
2750 _privileged_stack_top->oops_do(f);
2751 }
2753 // traverse the registered growable array
2754 if (_array_for_gc != NULL) {
2755 for (int index = 0; index < _array_for_gc->length(); index++) {
2756 f->do_oop(_array_for_gc->adr_at(index));
2757 }
2758 }
2760 // Traverse the monitor chunks
2761 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2762 chunk->oops_do(f);
2763 }
2765 // Traverse the execution stack
2766 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2767 fst.current()->oops_do(f, cld_f, cf, fst.register_map());
2768 }
2769 }
2771 // callee_target is never live across a gc point so NULL it here should
2772 // it still contain a methdOop.
2774 set_callee_target(NULL);
2776 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2777 // If we have deferred set_locals there might be oops waiting to be
2778 // written
2779 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2780 if (list != NULL) {
2781 for (int i = 0; i < list->length(); i++) {
2782 list->at(i)->oops_do(f);
2783 }
2784 }
2786 // Traverse instance variables at the end since the GC may be moving things
2787 // around using this function
2788 f->do_oop((oop*) &_threadObj);
2789 f->do_oop((oop*) &_vm_result);
2790 f->do_oop((oop*) &_exception_oop);
2791 f->do_oop((oop*) &_pending_async_exception);
2793 if (jvmti_thread_state() != NULL) {
2794 jvmti_thread_state()->oops_do(f);
2795 }
2796 }
2798 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2799 Thread::nmethods_do(cf); // (super method is a no-op)
2801 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2802 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2804 if (has_last_Java_frame()) {
2805 // Traverse the execution stack
2806 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2807 fst.current()->nmethods_do(cf);
2808 }
2809 }
2810 }
2812 void JavaThread::metadata_do(void f(Metadata*)) {
2813 Thread::metadata_do(f);
2814 if (has_last_Java_frame()) {
2815 // Traverse the execution stack to call f() on the methods in the stack
2816 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2817 fst.current()->metadata_do(f);
2818 }
2819 } else if (is_Compiler_thread()) {
2820 // need to walk ciMetadata in current compile tasks to keep alive.
2821 CompilerThread* ct = (CompilerThread*)this;
2822 if (ct->env() != NULL) {
2823 ct->env()->metadata_do(f);
2824 }
2825 }
2826 }
2828 // Printing
2829 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2830 switch (_thread_state) {
2831 case _thread_uninitialized: return "_thread_uninitialized";
2832 case _thread_new: return "_thread_new";
2833 case _thread_new_trans: return "_thread_new_trans";
2834 case _thread_in_native: return "_thread_in_native";
2835 case _thread_in_native_trans: return "_thread_in_native_trans";
2836 case _thread_in_vm: return "_thread_in_vm";
2837 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2838 case _thread_in_Java: return "_thread_in_Java";
2839 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2840 case _thread_blocked: return "_thread_blocked";
2841 case _thread_blocked_trans: return "_thread_blocked_trans";
2842 default: return "unknown thread state";
2843 }
2844 }
2846 #ifndef PRODUCT
2847 void JavaThread::print_thread_state_on(outputStream *st) const {
2848 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2849 };
2850 void JavaThread::print_thread_state() const {
2851 print_thread_state_on(tty);
2852 };
2853 #endif // PRODUCT
2855 // Called by Threads::print() for VM_PrintThreads operation
2856 void JavaThread::print_on(outputStream *st) const {
2857 st->print("\"%s\" ", get_thread_name());
2858 oop thread_oop = threadObj();
2859 if (thread_oop != NULL) {
2860 st->print("#" INT64_FORMAT " ", java_lang_Thread::thread_id(thread_oop));
2861 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2862 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2863 }
2864 Thread::print_on(st);
2865 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2866 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2867 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2868 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2869 }
2870 #ifndef PRODUCT
2871 print_thread_state_on(st);
2872 _safepoint_state->print_on(st);
2873 #endif // PRODUCT
2874 }
2876 // Called by fatal error handler. The difference between this and
2877 // JavaThread::print() is that we can't grab lock or allocate memory.
2878 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2879 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2880 oop thread_obj = threadObj();
2881 if (thread_obj != NULL) {
2882 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2883 }
2884 st->print(" [");
2885 st->print("%s", _get_thread_state_name(_thread_state));
2886 if (osthread()) {
2887 st->print(", id=%d", osthread()->thread_id());
2888 }
2889 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2890 _stack_base - _stack_size, _stack_base);
2891 st->print("]");
2892 return;
2893 }
2895 // Verification
2897 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2899 void JavaThread::verify() {
2900 // Verify oops in the thread.
2901 oops_do(&VerifyOopClosure::verify_oop, NULL, NULL);
2903 // Verify the stack frames.
2904 frames_do(frame_verify);
2905 }
2907 // CR 6300358 (sub-CR 2137150)
2908 // Most callers of this method assume that it can't return NULL but a
2909 // thread may not have a name whilst it is in the process of attaching to
2910 // the VM - see CR 6412693, and there are places where a JavaThread can be
2911 // seen prior to having it's threadObj set (eg JNI attaching threads and
2912 // if vm exit occurs during initialization). These cases can all be accounted
2913 // for such that this method never returns NULL.
2914 const char* JavaThread::get_thread_name() const {
2915 #ifdef ASSERT
2916 // early safepoints can hit while current thread does not yet have TLS
2917 if (!SafepointSynchronize::is_at_safepoint()) {
2918 Thread *cur = Thread::current();
2919 if (!(cur->is_Java_thread() && cur == this)) {
2920 // Current JavaThreads are allowed to get their own name without
2921 // the Threads_lock.
2922 assert_locked_or_safepoint(Threads_lock);
2923 }
2924 }
2925 #endif // ASSERT
2926 return get_thread_name_string();
2927 }
2929 // Returns a non-NULL representation of this thread's name, or a suitable
2930 // descriptive string if there is no set name
2931 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2932 const char* name_str;
2933 oop thread_obj = threadObj();
2934 if (thread_obj != NULL) {
2935 oop name = java_lang_Thread::name(thread_obj);
2936 if (name != NULL) {
2937 if (buf == NULL) {
2938 name_str = java_lang_String::as_utf8_string(name);
2939 }
2940 else {
2941 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
2942 }
2943 }
2944 else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2945 name_str = "<no-name - thread is attaching>";
2946 }
2947 else {
2948 name_str = Thread::name();
2949 }
2950 }
2951 else {
2952 name_str = Thread::name();
2953 }
2954 assert(name_str != NULL, "unexpected NULL thread name");
2955 return name_str;
2956 }
2959 const char* JavaThread::get_threadgroup_name() const {
2960 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2961 oop thread_obj = threadObj();
2962 if (thread_obj != NULL) {
2963 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2964 if (thread_group != NULL) {
2965 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2966 // ThreadGroup.name can be null
2967 if (name != NULL) {
2968 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2969 return str;
2970 }
2971 }
2972 }
2973 return NULL;
2974 }
2976 const char* JavaThread::get_parent_name() const {
2977 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2978 oop thread_obj = threadObj();
2979 if (thread_obj != NULL) {
2980 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2981 if (thread_group != NULL) {
2982 oop parent = java_lang_ThreadGroup::parent(thread_group);
2983 if (parent != NULL) {
2984 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2985 // ThreadGroup.name can be null
2986 if (name != NULL) {
2987 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2988 return str;
2989 }
2990 }
2991 }
2992 }
2993 return NULL;
2994 }
2996 ThreadPriority JavaThread::java_priority() const {
2997 oop thr_oop = threadObj();
2998 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2999 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
3000 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
3001 return priority;
3002 }
3004 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
3006 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
3007 // Link Java Thread object <-> C++ Thread
3009 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
3010 // and put it into a new Handle. The Handle "thread_oop" can then
3011 // be used to pass the C++ thread object to other methods.
3013 // Set the Java level thread object (jthread) field of the
3014 // new thread (a JavaThread *) to C++ thread object using the
3015 // "thread_oop" handle.
3017 // Set the thread field (a JavaThread *) of the
3018 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
3020 Handle thread_oop(Thread::current(),
3021 JNIHandles::resolve_non_null(jni_thread));
3022 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
3023 "must be initialized");
3024 set_threadObj(thread_oop());
3025 java_lang_Thread::set_thread(thread_oop(), this);
3027 if (prio == NoPriority) {
3028 prio = java_lang_Thread::priority(thread_oop());
3029 assert(prio != NoPriority, "A valid priority should be present");
3030 }
3032 // Push the Java priority down to the native thread; needs Threads_lock
3033 Thread::set_priority(this, prio);
3035 prepare_ext();
3037 // Add the new thread to the Threads list and set it in motion.
3038 // We must have threads lock in order to call Threads::add.
3039 // It is crucial that we do not block before the thread is
3040 // added to the Threads list for if a GC happens, then the java_thread oop
3041 // will not be visited by GC.
3042 Threads::add(this);
3043 }
3045 oop JavaThread::current_park_blocker() {
3046 // Support for JSR-166 locks
3047 oop thread_oop = threadObj();
3048 if (thread_oop != NULL &&
3049 JDK_Version::current().supports_thread_park_blocker()) {
3050 return java_lang_Thread::park_blocker(thread_oop);
3051 }
3052 return NULL;
3053 }
3056 void JavaThread::print_stack_on(outputStream* st) {
3057 if (!has_last_Java_frame()) return;
3058 ResourceMark rm;
3059 HandleMark hm;
3061 RegisterMap reg_map(this);
3062 vframe* start_vf = last_java_vframe(®_map);
3063 int count = 0;
3064 for (vframe* f = start_vf; f; f = f->sender() ) {
3065 if (f->is_java_frame()) {
3066 javaVFrame* jvf = javaVFrame::cast(f);
3067 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
3069 // Print out lock information
3070 if (JavaMonitorsInStackTrace) {
3071 jvf->print_lock_info_on(st, count);
3072 }
3073 } else {
3074 // Ignore non-Java frames
3075 }
3077 // Bail-out case for too deep stacks
3078 count++;
3079 if (MaxJavaStackTraceDepth == count) return;
3080 }
3081 }
3084 // JVMTI PopFrame support
3085 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
3086 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
3087 if (in_bytes(size_in_bytes) != 0) {
3088 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
3089 _popframe_preserved_args_size = in_bytes(size_in_bytes);
3090 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
3091 }
3092 }
3094 void* JavaThread::popframe_preserved_args() {
3095 return _popframe_preserved_args;
3096 }
3098 ByteSize JavaThread::popframe_preserved_args_size() {
3099 return in_ByteSize(_popframe_preserved_args_size);
3100 }
3102 WordSize JavaThread::popframe_preserved_args_size_in_words() {
3103 int sz = in_bytes(popframe_preserved_args_size());
3104 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
3105 return in_WordSize(sz / wordSize);
3106 }
3108 void JavaThread::popframe_free_preserved_args() {
3109 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
3110 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args, mtThread);
3111 _popframe_preserved_args = NULL;
3112 _popframe_preserved_args_size = 0;
3113 }
3115 #ifndef PRODUCT
3117 void JavaThread::trace_frames() {
3118 tty->print_cr("[Describe stack]");
3119 int frame_no = 1;
3120 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
3121 tty->print(" %d. ", frame_no++);
3122 fst.current()->print_value_on(tty,this);
3123 tty->cr();
3124 }
3125 }
3127 class PrintAndVerifyOopClosure: public OopClosure {
3128 protected:
3129 template <class T> inline void do_oop_work(T* p) {
3130 oop obj = oopDesc::load_decode_heap_oop(p);
3131 if (obj == NULL) return;
3132 tty->print(INTPTR_FORMAT ": ", p);
3133 if (obj->is_oop_or_null()) {
3134 if (obj->is_objArray()) {
3135 tty->print_cr("valid objArray: " INTPTR_FORMAT, (oopDesc*) obj);
3136 } else {
3137 obj->print();
3138 }
3139 } else {
3140 tty->print_cr("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj);
3141 }
3142 tty->cr();
3143 }
3144 public:
3145 virtual void do_oop(oop* p) { do_oop_work(p); }
3146 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
3147 };
3150 static void oops_print(frame* f, const RegisterMap *map) {
3151 PrintAndVerifyOopClosure print;
3152 f->print_value();
3153 f->oops_do(&print, NULL, NULL, (RegisterMap*)map);
3154 }
3156 // Print our all the locations that contain oops and whether they are
3157 // valid or not. This useful when trying to find the oldest frame
3158 // where an oop has gone bad since the frame walk is from youngest to
3159 // oldest.
3160 void JavaThread::trace_oops() {
3161 tty->print_cr("[Trace oops]");
3162 frames_do(oops_print);
3163 }
3166 #ifdef ASSERT
3167 // Print or validate the layout of stack frames
3168 void JavaThread::print_frame_layout(int depth, bool validate_only) {
3169 ResourceMark rm;
3170 PRESERVE_EXCEPTION_MARK;
3171 FrameValues values;
3172 int frame_no = 0;
3173 for(StackFrameStream fst(this, false); !fst.is_done(); fst.next()) {
3174 fst.current()->describe(values, ++frame_no);
3175 if (depth == frame_no) break;
3176 }
3177 if (validate_only) {
3178 values.validate();
3179 } else {
3180 tty->print_cr("[Describe stack layout]");
3181 values.print(this);
3182 }
3183 }
3184 #endif
3186 void JavaThread::trace_stack_from(vframe* start_vf) {
3187 ResourceMark rm;
3188 int vframe_no = 1;
3189 for (vframe* f = start_vf; f; f = f->sender() ) {
3190 if (f->is_java_frame()) {
3191 javaVFrame::cast(f)->print_activation(vframe_no++);
3192 } else {
3193 f->print();
3194 }
3195 if (vframe_no > StackPrintLimit) {
3196 tty->print_cr("...<more frames>...");
3197 return;
3198 }
3199 }
3200 }
3203 void JavaThread::trace_stack() {
3204 if (!has_last_Java_frame()) return;
3205 ResourceMark rm;
3206 HandleMark hm;
3207 RegisterMap reg_map(this);
3208 trace_stack_from(last_java_vframe(®_map));
3209 }
3212 #endif // PRODUCT
3215 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
3216 assert(reg_map != NULL, "a map must be given");
3217 frame f = last_frame();
3218 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
3219 if (vf->is_java_frame()) return javaVFrame::cast(vf);
3220 }
3221 return NULL;
3222 }
3225 Klass* JavaThread::security_get_caller_class(int depth) {
3226 vframeStream vfst(this);
3227 vfst.security_get_caller_frame(depth);
3228 if (!vfst.at_end()) {
3229 return vfst.method()->method_holder();
3230 }
3231 return NULL;
3232 }
3234 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
3235 assert(thread->is_Compiler_thread(), "must be compiler thread");
3236 CompileBroker::compiler_thread_loop();
3237 }
3239 // Create a CompilerThread
3240 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
3241 : JavaThread(&compiler_thread_entry) {
3242 _env = NULL;
3243 _log = NULL;
3244 _task = NULL;
3245 _queue = queue;
3246 _counters = counters;
3247 _buffer_blob = NULL;
3248 _scanned_nmethod = NULL;
3249 _compiler = NULL;
3251 #ifndef PRODUCT
3252 _ideal_graph_printer = NULL;
3253 #endif
3254 }
3256 void CompilerThread::oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf) {
3257 JavaThread::oops_do(f, cld_f, cf);
3258 if (_scanned_nmethod != NULL && cf != NULL) {
3259 // Safepoints can occur when the sweeper is scanning an nmethod so
3260 // process it here to make sure it isn't unloaded in the middle of
3261 // a scan.
3262 cf->do_code_blob(_scanned_nmethod);
3263 }
3264 }
3267 // ======= Threads ========
3269 // The Threads class links together all active threads, and provides
3270 // operations over all threads. It is protected by its own Mutex
3271 // lock, which is also used in other contexts to protect thread
3272 // operations from having the thread being operated on from exiting
3273 // and going away unexpectedly (e.g., safepoint synchronization)
3275 JavaThread* Threads::_thread_list = NULL;
3276 int Threads::_number_of_threads = 0;
3277 int Threads::_number_of_non_daemon_threads = 0;
3278 int Threads::_return_code = 0;
3279 size_t JavaThread::_stack_size_at_create = 0;
3280 #ifdef ASSERT
3281 bool Threads::_vm_complete = false;
3282 #endif
3284 // All JavaThreads
3285 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
3287 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
3288 void Threads::threads_do(ThreadClosure* tc) {
3289 assert_locked_or_safepoint(Threads_lock);
3290 // ALL_JAVA_THREADS iterates through all JavaThreads
3291 ALL_JAVA_THREADS(p) {
3292 tc->do_thread(p);
3293 }
3294 // Someday we could have a table or list of all non-JavaThreads.
3295 // For now, just manually iterate through them.
3296 tc->do_thread(VMThread::vm_thread());
3297 Universe::heap()->gc_threads_do(tc);
3298 WatcherThread *wt = WatcherThread::watcher_thread();
3299 // Strictly speaking, the following NULL check isn't sufficient to make sure
3300 // the data for WatcherThread is still valid upon being examined. However,
3301 // considering that WatchThread terminates when the VM is on the way to
3302 // exit at safepoint, the chance of the above is extremely small. The right
3303 // way to prevent termination of WatcherThread would be to acquire
3304 // Terminator_lock, but we can't do that without violating the lock rank
3305 // checking in some cases.
3306 if (wt != NULL)
3307 tc->do_thread(wt);
3309 // If CompilerThreads ever become non-JavaThreads, add them here
3310 }
3312 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
3314 extern void JDK_Version_init();
3316 // Preinitialize version info.
3317 VM_Version::early_initialize();
3319 // Check version
3320 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
3322 // Initialize the output stream module
3323 ostream_init();
3325 // Process java launcher properties.
3326 Arguments::process_sun_java_launcher_properties(args);
3328 // Initialize the os module before using TLS
3329 os::init();
3331 // Initialize system properties.
3332 Arguments::init_system_properties();
3334 // So that JDK version can be used as a discrimintor when parsing arguments
3335 JDK_Version_init();
3337 // Update/Initialize System properties after JDK version number is known
3338 Arguments::init_version_specific_system_properties();
3340 // Parse arguments
3341 jint parse_result = Arguments::parse(args);
3342 if (parse_result != JNI_OK) return parse_result;
3344 os::init_before_ergo();
3346 jint ergo_result = Arguments::apply_ergo();
3347 if (ergo_result != JNI_OK) return ergo_result;
3349 if (PauseAtStartup) {
3350 os::pause();
3351 }
3353 #ifndef USDT2
3354 HS_DTRACE_PROBE(hotspot, vm__init__begin);
3355 #else /* USDT2 */
3356 HOTSPOT_VM_INIT_BEGIN();
3357 #endif /* USDT2 */
3359 // Record VM creation timing statistics
3360 TraceVmCreationTime create_vm_timer;
3361 create_vm_timer.start();
3363 // Timing (must come after argument parsing)
3364 TraceTime timer("Create VM", TraceStartupTime);
3366 // Initialize the os module after parsing the args
3367 jint os_init_2_result = os::init_2();
3368 if (os_init_2_result != JNI_OK) return os_init_2_result;
3370 jint adjust_after_os_result = Arguments::adjust_after_os();
3371 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
3373 // intialize TLS
3374 ThreadLocalStorage::init();
3376 // Initialize output stream logging
3377 ostream_init_log();
3379 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
3380 // Must be before create_vm_init_agents()
3381 if (Arguments::init_libraries_at_startup()) {
3382 convert_vm_init_libraries_to_agents();
3383 }
3385 // Launch -agentlib/-agentpath and converted -Xrun agents
3386 if (Arguments::init_agents_at_startup()) {
3387 create_vm_init_agents();
3388 }
3390 // Initialize Threads state
3391 _thread_list = NULL;
3392 _number_of_threads = 0;
3393 _number_of_non_daemon_threads = 0;
3395 // Initialize global data structures and create system classes in heap
3396 vm_init_globals();
3398 // Attach the main thread to this os thread
3399 JavaThread* main_thread = new JavaThread();
3400 main_thread->set_thread_state(_thread_in_vm);
3401 // must do this before set_active_handles and initialize_thread_local_storage
3402 // Note: on solaris initialize_thread_local_storage() will (indirectly)
3403 // change the stack size recorded here to one based on the java thread
3404 // stacksize. This adjusted size is what is used to figure the placement
3405 // of the guard pages.
3406 main_thread->record_stack_base_and_size();
3407 main_thread->initialize_thread_local_storage();
3409 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
3411 if (!main_thread->set_as_starting_thread()) {
3412 vm_shutdown_during_initialization(
3413 "Failed necessary internal allocation. Out of swap space");
3414 delete main_thread;
3415 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3416 return JNI_ENOMEM;
3417 }
3419 // Enable guard page *after* os::create_main_thread(), otherwise it would
3420 // crash Linux VM, see notes in os_linux.cpp.
3421 main_thread->create_stack_guard_pages();
3423 // Initialize Java-Level synchronization subsystem
3424 ObjectMonitor::Initialize() ;
3426 // Initialize global modules
3427 jint status = init_globals();
3428 if (status != JNI_OK) {
3429 delete main_thread;
3430 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3431 return status;
3432 }
3434 #ifdef MIPS64
3435 /* 2013/11/5 Jin: To be accessed in NativeGeneralJump::patch_verified_entry() */
3436 main_thread->set_handle_wrong_method_stub(SharedRuntime::get_handle_wrong_method_stub());
3437 #endif
3439 // Should be done after the heap is fully created
3440 main_thread->cache_global_variables();
3442 HandleMark hm;
3444 { MutexLocker mu(Threads_lock);
3445 Threads::add(main_thread);
3446 }
3448 // Any JVMTI raw monitors entered in onload will transition into
3449 // real raw monitor. VM is setup enough here for raw monitor enter.
3450 JvmtiExport::transition_pending_onload_raw_monitors();
3452 // Create the VMThread
3453 { TraceTime timer("Start VMThread", TraceStartupTime);
3454 VMThread::create();
3455 Thread* vmthread = VMThread::vm_thread();
3457 if (!os::create_thread(vmthread, os::vm_thread))
3458 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
3460 // Wait for the VM thread to become ready, and VMThread::run to initialize
3461 // Monitors can have spurious returns, must always check another state flag
3462 {
3463 MutexLocker ml(Notify_lock);
3464 os::start_thread(vmthread);
3465 while (vmthread->active_handles() == NULL) {
3466 Notify_lock->wait();
3467 }
3468 }
3469 }
3471 assert (Universe::is_fully_initialized(), "not initialized");
3472 if (VerifyDuringStartup) {
3473 // Make sure we're starting with a clean slate.
3474 VM_Verify verify_op;
3475 VMThread::execute(&verify_op);
3476 }
3478 EXCEPTION_MARK;
3480 // At this point, the Universe is initialized, but we have not executed
3481 // any byte code. Now is a good time (the only time) to dump out the
3482 // internal state of the JVM for sharing.
3483 if (DumpSharedSpaces) {
3484 MetaspaceShared::preload_and_dump(CHECK_0);
3485 ShouldNotReachHere();
3486 }
3488 // Always call even when there are not JVMTI environments yet, since environments
3489 // may be attached late and JVMTI must track phases of VM execution
3490 JvmtiExport::enter_start_phase();
3492 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3493 JvmtiExport::post_vm_start();
3495 {
3496 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3498 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3499 create_vm_init_libraries();
3500 }
3502 initialize_class(vmSymbols::java_lang_String(), CHECK_0);
3504 // Initialize java_lang.System (needed before creating the thread)
3505 initialize_class(vmSymbols::java_lang_System(), CHECK_0);
3506 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK_0);
3507 Handle thread_group = create_initial_thread_group(CHECK_0);
3508 Universe::set_main_thread_group(thread_group());
3509 initialize_class(vmSymbols::java_lang_Thread(), CHECK_0);
3510 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3511 main_thread->set_threadObj(thread_object);
3512 // Set thread status to running since main thread has
3513 // been started and running.
3514 java_lang_Thread::set_thread_status(thread_object,
3515 java_lang_Thread::RUNNABLE);
3517 // The VM creates & returns objects of this class. Make sure it's initialized.
3518 initialize_class(vmSymbols::java_lang_Class(), CHECK_0);
3520 // The VM preresolves methods to these classes. Make sure that they get initialized
3521 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK_0);
3522 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK_0);
3523 call_initializeSystemClass(CHECK_0);
3525 // get the Java runtime name after java.lang.System is initialized
3526 JDK_Version::set_runtime_name(get_java_runtime_name(THREAD));
3527 JDK_Version::set_runtime_version(get_java_runtime_version(THREAD));
3529 // an instance of OutOfMemory exception has been allocated earlier
3530 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK_0);
3531 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK_0);
3532 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK_0);
3533 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK_0);
3534 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK_0);
3535 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK_0);
3536 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK_0);
3537 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK_0);
3538 }
3540 // See : bugid 4211085.
3541 // Background : the static initializer of java.lang.Compiler tries to read
3542 // property"java.compiler" and read & write property "java.vm.info".
3543 // When a security manager is installed through the command line
3544 // option "-Djava.security.manager", the above properties are not
3545 // readable and the static initializer for java.lang.Compiler fails
3546 // resulting in a NoClassDefFoundError. This can happen in any
3547 // user code which calls methods in java.lang.Compiler.
3548 // Hack : the hack is to pre-load and initialize this class, so that only
3549 // system domains are on the stack when the properties are read.
3550 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3551 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3552 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3553 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3554 // Once that is done, we should remove this hack.
3555 initialize_class(vmSymbols::java_lang_Compiler(), CHECK_0);
3557 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3558 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3559 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3560 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3561 // This should also be taken out as soon as 4211383 gets fixed.
3562 reset_vm_info_property(CHECK_0);
3564 quicken_jni_functions();
3566 // Must be run after init_ft which initializes ft_enabled
3567 if (TRACE_INITIALIZE() != JNI_OK) {
3568 vm_exit_during_initialization("Failed to initialize tracing backend");
3569 }
3571 // Set flag that basic initialization has completed. Used by exceptions and various
3572 // debug stuff, that does not work until all basic classes have been initialized.
3573 set_init_completed();
3575 Metaspace::post_initialize();
3577 #ifndef USDT2
3578 HS_DTRACE_PROBE(hotspot, vm__init__end);
3579 #else /* USDT2 */
3580 HOTSPOT_VM_INIT_END();
3581 #endif /* USDT2 */
3583 // record VM initialization completion time
3584 #if INCLUDE_MANAGEMENT
3585 Management::record_vm_init_completed();
3586 #endif // INCLUDE_MANAGEMENT
3588 // Compute system loader. Note that this has to occur after set_init_completed, since
3589 // valid exceptions may be thrown in the process.
3590 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3591 // set_init_completed has just been called, causing exceptions not to be shortcut
3592 // anymore. We call vm_exit_during_initialization directly instead.
3593 SystemDictionary::compute_java_system_loader(THREAD);
3594 if (HAS_PENDING_EXCEPTION) {
3595 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3596 }
3598 #if INCLUDE_ALL_GCS
3599 // Support for ConcurrentMarkSweep. This should be cleaned up
3600 // and better encapsulated. The ugly nested if test would go away
3601 // once things are properly refactored. XXX YSR
3602 if (UseConcMarkSweepGC || UseG1GC) {
3603 if (UseConcMarkSweepGC) {
3604 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3605 } else {
3606 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3607 }
3608 if (HAS_PENDING_EXCEPTION) {
3609 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3610 }
3611 }
3612 #endif // INCLUDE_ALL_GCS
3614 // Always call even when there are not JVMTI environments yet, since environments
3615 // may be attached late and JVMTI must track phases of VM execution
3616 JvmtiExport::enter_live_phase();
3618 // Signal Dispatcher needs to be started before VMInit event is posted
3619 os::signal_init();
3621 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3622 if (!DisableAttachMechanism) {
3623 AttachListener::vm_start();
3624 if (StartAttachListener || AttachListener::init_at_startup()) {
3625 AttachListener::init();
3626 }
3627 }
3629 // Launch -Xrun agents
3630 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3631 // back-end can launch with -Xdebug -Xrunjdwp.
3632 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3633 create_vm_init_libraries();
3634 }
3636 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3637 JvmtiExport::post_vm_initialized();
3639 if (TRACE_START() != JNI_OK) {
3640 vm_exit_during_initialization("Failed to start tracing backend.");
3641 }
3643 if (CleanChunkPoolAsync) {
3644 Chunk::start_chunk_pool_cleaner_task();
3645 }
3647 // initialize compiler(s)
3648 #if defined(COMPILER1) || defined(COMPILER2) || defined(SHARK)
3649 CompileBroker::compilation_init();
3650 #endif
3652 if (EnableInvokeDynamic) {
3653 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
3654 // It is done after compilers are initialized, because otherwise compilations of
3655 // signature polymorphic MH intrinsics can be missed
3656 // (see SystemDictionary::find_method_handle_intrinsic).
3657 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK_0);
3658 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK_0);
3659 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK_0);
3660 }
3662 #if INCLUDE_MANAGEMENT
3663 Management::initialize(THREAD);
3664 #endif // INCLUDE_MANAGEMENT
3666 if (HAS_PENDING_EXCEPTION) {
3667 // management agent fails to start possibly due to
3668 // configuration problem and is responsible for printing
3669 // stack trace if appropriate. Simply exit VM.
3670 vm_exit(1);
3671 }
3673 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3674 if (MemProfiling) MemProfiler::engage();
3675 StatSampler::engage();
3676 if (CheckJNICalls) JniPeriodicChecker::engage();
3678 BiasedLocking::init();
3680 #if INCLUDE_RTM_OPT
3681 RTMLockingCounters::init();
3682 #endif
3684 if (JDK_Version::current().post_vm_init_hook_enabled()) {
3685 call_postVMInitHook(THREAD);
3686 // The Java side of PostVMInitHook.run must deal with all
3687 // exceptions and provide means of diagnosis.
3688 if (HAS_PENDING_EXCEPTION) {
3689 CLEAR_PENDING_EXCEPTION;
3690 }
3691 }
3693 {
3694 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
3695 // Make sure the watcher thread can be started by WatcherThread::start()
3696 // or by dynamic enrollment.
3697 WatcherThread::make_startable();
3698 // Start up the WatcherThread if there are any periodic tasks
3699 // NOTE: All PeriodicTasks should be registered by now. If they
3700 // aren't, late joiners might appear to start slowly (we might
3701 // take a while to process their first tick).
3702 if (PeriodicTask::num_tasks() > 0) {
3703 WatcherThread::start();
3704 }
3705 }
3707 create_vm_timer.end();
3708 #ifdef ASSERT
3709 _vm_complete = true;
3710 #endif
3711 return JNI_OK;
3712 }
3714 // type for the Agent_OnLoad and JVM_OnLoad entry points
3715 extern "C" {
3716 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3717 }
3718 // Find a command line agent library and return its entry point for
3719 // -agentlib: -agentpath: -Xrun
3720 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3721 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3722 OnLoadEntry_t on_load_entry = NULL;
3723 void *library = NULL;
3725 if (!agent->valid()) {
3726 char buffer[JVM_MAXPATHLEN];
3727 char ebuf[1024];
3728 const char *name = agent->name();
3729 const char *msg = "Could not find agent library ";
3731 // First check to see if agent is statically linked into executable
3732 if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
3733 library = agent->os_lib();
3734 } else if (agent->is_absolute_path()) {
3735 library = os::dll_load(name, ebuf, sizeof ebuf);
3736 if (library == NULL) {
3737 const char *sub_msg = " in absolute path, with error: ";
3738 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3739 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3740 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3741 // If we can't find the agent, exit.
3742 vm_exit_during_initialization(buf, NULL);
3743 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3744 }
3745 } else {
3746 // Try to load the agent from the standard dll directory
3747 if (os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
3748 name)) {
3749 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3750 }
3751 if (library == NULL) { // Try the local directory
3752 char ns[1] = {0};
3753 if (os::dll_build_name(buffer, sizeof(buffer), ns, name)) {
3754 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3755 }
3756 if (library == NULL) {
3757 const char *sub_msg = " on the library path, with error: ";
3758 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3759 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3760 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3761 // If we can't find the agent, exit.
3762 vm_exit_during_initialization(buf, NULL);
3763 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3764 }
3765 }
3766 }
3767 agent->set_os_lib(library);
3768 agent->set_valid();
3769 }
3771 // Find the OnLoad function.
3772 on_load_entry =
3773 CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
3774 false,
3775 on_load_symbols,
3776 num_symbol_entries));
3777 return on_load_entry;
3778 }
3780 // Find the JVM_OnLoad entry point
3781 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3782 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3783 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3784 }
3786 // Find the Agent_OnLoad entry point
3787 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3788 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3789 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3790 }
3792 // For backwards compatibility with -Xrun
3793 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3794 // treated like -agentpath:
3795 // Must be called before agent libraries are created
3796 void Threads::convert_vm_init_libraries_to_agents() {
3797 AgentLibrary* agent;
3798 AgentLibrary* next;
3800 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3801 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3802 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3804 // If there is an JVM_OnLoad function it will get called later,
3805 // otherwise see if there is an Agent_OnLoad
3806 if (on_load_entry == NULL) {
3807 on_load_entry = lookup_agent_on_load(agent);
3808 if (on_load_entry != NULL) {
3809 // switch it to the agent list -- so that Agent_OnLoad will be called,
3810 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3811 Arguments::convert_library_to_agent(agent);
3812 } else {
3813 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3814 }
3815 }
3816 }
3817 }
3819 // Create agents for -agentlib: -agentpath: and converted -Xrun
3820 // Invokes Agent_OnLoad
3821 // Called very early -- before JavaThreads exist
3822 void Threads::create_vm_init_agents() {
3823 extern struct JavaVM_ main_vm;
3824 AgentLibrary* agent;
3826 JvmtiExport::enter_onload_phase();
3828 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3829 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3831 if (on_load_entry != NULL) {
3832 // Invoke the Agent_OnLoad function
3833 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3834 if (err != JNI_OK) {
3835 vm_exit_during_initialization("agent library failed to init", agent->name());
3836 }
3837 } else {
3838 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3839 }
3840 }
3841 JvmtiExport::enter_primordial_phase();
3842 }
3844 extern "C" {
3845 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3846 }
3848 void Threads::shutdown_vm_agents() {
3849 // Send any Agent_OnUnload notifications
3850 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3851 size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
3852 extern struct JavaVM_ main_vm;
3853 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3855 // Find the Agent_OnUnload function.
3856 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3857 os::find_agent_function(agent,
3858 false,
3859 on_unload_symbols,
3860 num_symbol_entries));
3862 // Invoke the Agent_OnUnload function
3863 if (unload_entry != NULL) {
3864 JavaThread* thread = JavaThread::current();
3865 ThreadToNativeFromVM ttn(thread);
3866 HandleMark hm(thread);
3867 (*unload_entry)(&main_vm);
3868 }
3869 }
3870 }
3872 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3873 // Invokes JVM_OnLoad
3874 void Threads::create_vm_init_libraries() {
3875 extern struct JavaVM_ main_vm;
3876 AgentLibrary* agent;
3878 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3879 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3881 if (on_load_entry != NULL) {
3882 // Invoke the JVM_OnLoad function
3883 JavaThread* thread = JavaThread::current();
3884 ThreadToNativeFromVM ttn(thread);
3885 HandleMark hm(thread);
3886 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3887 if (err != JNI_OK) {
3888 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3889 }
3890 } else {
3891 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3892 }
3893 }
3894 }
3896 JavaThread* Threads::find_java_thread_from_java_tid(jlong java_tid) {
3897 assert(Threads_lock->owned_by_self(), "Must hold Threads_lock");
3899 JavaThread* java_thread = NULL;
3900 // Sequential search for now. Need to do better optimization later.
3901 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
3902 oop tobj = thread->threadObj();
3903 if (!thread->is_exiting() &&
3904 tobj != NULL &&
3905 java_tid == java_lang_Thread::thread_id(tobj)) {
3906 java_thread = thread;
3907 break;
3908 }
3909 }
3910 return java_thread;
3911 }
3914 // Last thread running calls java.lang.Shutdown.shutdown()
3915 void JavaThread::invoke_shutdown_hooks() {
3916 HandleMark hm(this);
3918 // We could get here with a pending exception, if so clear it now.
3919 if (this->has_pending_exception()) {
3920 this->clear_pending_exception();
3921 }
3923 EXCEPTION_MARK;
3924 Klass* k =
3925 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3926 THREAD);
3927 if (k != NULL) {
3928 // SystemDictionary::resolve_or_null will return null if there was
3929 // an exception. If we cannot load the Shutdown class, just don't
3930 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3931 // and finalizers (if runFinalizersOnExit is set) won't be run.
3932 // Note that if a shutdown hook was registered or runFinalizersOnExit
3933 // was called, the Shutdown class would have already been loaded
3934 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3935 instanceKlassHandle shutdown_klass (THREAD, k);
3936 JavaValue result(T_VOID);
3937 JavaCalls::call_static(&result,
3938 shutdown_klass,
3939 vmSymbols::shutdown_method_name(),
3940 vmSymbols::void_method_signature(),
3941 THREAD);
3942 }
3943 CLEAR_PENDING_EXCEPTION;
3944 }
3946 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3947 // the program falls off the end of main(). Another VM exit path is through
3948 // vm_exit() when the program calls System.exit() to return a value or when
3949 // there is a serious error in VM. The two shutdown paths are not exactly
3950 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3951 // and VM_Exit op at VM level.
3952 //
3953 // Shutdown sequence:
3954 // + Shutdown native memory tracking if it is on
3955 // + Wait until we are the last non-daemon thread to execute
3956 // <-- every thing is still working at this moment -->
3957 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3958 // shutdown hooks, run finalizers if finalization-on-exit
3959 // + Call before_exit(), prepare for VM exit
3960 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3961 // currently the only user of this mechanism is File.deleteOnExit())
3962 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3963 // post thread end and vm death events to JVMTI,
3964 // stop signal thread
3965 // + Call JavaThread::exit(), it will:
3966 // > release JNI handle blocks, remove stack guard pages
3967 // > remove this thread from Threads list
3968 // <-- no more Java code from this thread after this point -->
3969 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3970 // the compiler threads at safepoint
3971 // <-- do not use anything that could get blocked by Safepoint -->
3972 // + Disable tracing at JNI/JVM barriers
3973 // + Set _vm_exited flag for threads that are still running native code
3974 // + Delete this thread
3975 // + Call exit_globals()
3976 // > deletes tty
3977 // > deletes PerfMemory resources
3978 // + Return to caller
3980 bool Threads::destroy_vm() {
3981 JavaThread* thread = JavaThread::current();
3983 #ifdef ASSERT
3984 _vm_complete = false;
3985 #endif
3986 // Wait until we are the last non-daemon thread to execute
3987 { MutexLocker nu(Threads_lock);
3988 while (Threads::number_of_non_daemon_threads() > 1 )
3989 // This wait should make safepoint checks, wait without a timeout,
3990 // and wait as a suspend-equivalent condition.
3991 //
3992 // Note: If the FlatProfiler is running and this thread is waiting
3993 // for another non-daemon thread to finish, then the FlatProfiler
3994 // is waiting for the external suspend request on this thread to
3995 // complete. wait_for_ext_suspend_completion() will eventually
3996 // timeout, but that takes time. Making this wait a suspend-
3997 // equivalent condition solves that timeout problem.
3998 //
3999 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
4000 Mutex::_as_suspend_equivalent_flag);
4001 }
4003 // Hang forever on exit if we are reporting an error.
4004 if (ShowMessageBoxOnError && is_error_reported()) {
4005 os::infinite_sleep();
4006 }
4007 os::wait_for_keypress_at_exit();
4009 if (JDK_Version::is_jdk12x_version()) {
4010 // We are the last thread running, so check if finalizers should be run.
4011 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
4012 HandleMark rm(thread);
4013 Universe::run_finalizers_on_exit();
4014 } else {
4015 // run Java level shutdown hooks
4016 thread->invoke_shutdown_hooks();
4017 }
4019 before_exit(thread);
4021 thread->exit(true);
4023 // Stop VM thread.
4024 {
4025 // 4945125 The vm thread comes to a safepoint during exit.
4026 // GC vm_operations can get caught at the safepoint, and the
4027 // heap is unparseable if they are caught. Grab the Heap_lock
4028 // to prevent this. The GC vm_operations will not be able to
4029 // queue until after the vm thread is dead. After this point,
4030 // we'll never emerge out of the safepoint before the VM exits.
4032 MutexLocker ml(Heap_lock);
4034 VMThread::wait_for_vm_thread_exit();
4035 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
4036 VMThread::destroy();
4037 }
4039 // clean up ideal graph printers
4040 #if defined(COMPILER2) && !defined(PRODUCT)
4041 IdealGraphPrinter::clean_up();
4042 #endif
4044 // Now, all Java threads are gone except daemon threads. Daemon threads
4045 // running Java code or in VM are stopped by the Safepoint. However,
4046 // daemon threads executing native code are still running. But they
4047 // will be stopped at native=>Java/VM barriers. Note that we can't
4048 // simply kill or suspend them, as it is inherently deadlock-prone.
4050 #ifndef PRODUCT
4051 // disable function tracing at JNI/JVM barriers
4052 TraceJNICalls = false;
4053 TraceJVMCalls = false;
4054 TraceRuntimeCalls = false;
4055 #endif
4057 VM_Exit::set_vm_exited();
4059 notify_vm_shutdown();
4061 delete thread;
4063 // exit_globals() will delete tty
4064 exit_globals();
4066 return true;
4067 }
4070 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
4071 if (version == JNI_VERSION_1_1) return JNI_TRUE;
4072 return is_supported_jni_version(version);
4073 }
4076 jboolean Threads::is_supported_jni_version(jint version) {
4077 if (version == JNI_VERSION_1_2) return JNI_TRUE;
4078 if (version == JNI_VERSION_1_4) return JNI_TRUE;
4079 if (version == JNI_VERSION_1_6) return JNI_TRUE;
4080 if (version == JNI_VERSION_1_8) return JNI_TRUE;
4081 return JNI_FALSE;
4082 }
4085 void Threads::add(JavaThread* p, bool force_daemon) {
4086 // The threads lock must be owned at this point
4087 assert_locked_or_safepoint(Threads_lock);
4089 // See the comment for this method in thread.hpp for its purpose and
4090 // why it is called here.
4091 p->initialize_queues();
4092 p->set_next(_thread_list);
4093 _thread_list = p;
4094 _number_of_threads++;
4095 oop threadObj = p->threadObj();
4096 bool daemon = true;
4097 // Bootstrapping problem: threadObj can be null for initial
4098 // JavaThread (or for threads attached via JNI)
4099 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
4100 _number_of_non_daemon_threads++;
4101 daemon = false;
4102 }
4104 ThreadService::add_thread(p, daemon);
4106 // Possible GC point.
4107 Events::log(p, "Thread added: " INTPTR_FORMAT, p);
4108 }
4110 void Threads::remove(JavaThread* p) {
4111 // Extra scope needed for Thread_lock, so we can check
4112 // that we do not remove thread without safepoint code notice
4113 { MutexLocker ml(Threads_lock);
4115 assert(includes(p), "p must be present");
4117 JavaThread* current = _thread_list;
4118 JavaThread* prev = NULL;
4120 while (current != p) {
4121 prev = current;
4122 current = current->next();
4123 }
4125 if (prev) {
4126 prev->set_next(current->next());
4127 } else {
4128 _thread_list = p->next();
4129 }
4130 _number_of_threads--;
4131 oop threadObj = p->threadObj();
4132 bool daemon = true;
4133 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
4134 _number_of_non_daemon_threads--;
4135 daemon = false;
4137 // Only one thread left, do a notify on the Threads_lock so a thread waiting
4138 // on destroy_vm will wake up.
4139 if (number_of_non_daemon_threads() == 1)
4140 Threads_lock->notify_all();
4141 }
4142 ThreadService::remove_thread(p, daemon);
4144 // Make sure that safepoint code disregard this thread. This is needed since
4145 // the thread might mess around with locks after this point. This can cause it
4146 // to do callbacks into the safepoint code. However, the safepoint code is not aware
4147 // of this thread since it is removed from the queue.
4148 p->set_terminated_value();
4149 } // unlock Threads_lock
4151 // Since Events::log uses a lock, we grab it outside the Threads_lock
4152 Events::log(p, "Thread exited: " INTPTR_FORMAT, p);
4153 }
4155 // Threads_lock must be held when this is called (or must be called during a safepoint)
4156 bool Threads::includes(JavaThread* p) {
4157 assert(Threads_lock->is_locked(), "sanity check");
4158 ALL_JAVA_THREADS(q) {
4159 if (q == p ) {
4160 return true;
4161 }
4162 }
4163 return false;
4164 }
4166 // Operations on the Threads list for GC. These are not explicitly locked,
4167 // but the garbage collector must provide a safe context for them to run.
4168 // In particular, these things should never be called when the Threads_lock
4169 // is held by some other thread. (Note: the Safepoint abstraction also
4170 // uses the Threads_lock to gurantee this property. It also makes sure that
4171 // all threads gets blocked when exiting or starting).
4173 void Threads::oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf) {
4174 ALL_JAVA_THREADS(p) {
4175 p->oops_do(f, cld_f, cf);
4176 }
4177 VMThread::vm_thread()->oops_do(f, cld_f, cf);
4178 }
4180 void Threads::possibly_parallel_oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf) {
4181 // Introduce a mechanism allowing parallel threads to claim threads as
4182 // root groups. Overhead should be small enough to use all the time,
4183 // even in sequential code.
4184 SharedHeap* sh = SharedHeap::heap();
4185 // Cannot yet substitute active_workers for n_par_threads
4186 // because of G1CollectedHeap::verify() use of
4187 // SharedHeap::process_roots(). n_par_threads == 0 will
4188 // turn off parallelism in process_roots while active_workers
4189 // is being used for parallelism elsewhere.
4190 bool is_par = sh->n_par_threads() > 0;
4191 assert(!is_par ||
4192 (SharedHeap::heap()->n_par_threads() ==
4193 SharedHeap::heap()->workers()->active_workers()), "Mismatch");
4194 int cp = SharedHeap::heap()->strong_roots_parity();
4195 ALL_JAVA_THREADS(p) {
4196 if (p->claim_oops_do(is_par, cp)) {
4197 p->oops_do(f, cld_f, cf);
4198 }
4199 }
4200 VMThread* vmt = VMThread::vm_thread();
4201 if (vmt->claim_oops_do(is_par, cp)) {
4202 vmt->oops_do(f, cld_f, cf);
4203 }
4204 }
4206 #if INCLUDE_ALL_GCS
4207 // Used by ParallelScavenge
4208 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
4209 ALL_JAVA_THREADS(p) {
4210 q->enqueue(new ThreadRootsTask(p));
4211 }
4212 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
4213 }
4215 // Used by Parallel Old
4216 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
4217 ALL_JAVA_THREADS(p) {
4218 q->enqueue(new ThreadRootsMarkingTask(p));
4219 }
4220 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
4221 }
4222 #endif // INCLUDE_ALL_GCS
4224 void Threads::nmethods_do(CodeBlobClosure* cf) {
4225 ALL_JAVA_THREADS(p) {
4226 p->nmethods_do(cf);
4227 }
4228 VMThread::vm_thread()->nmethods_do(cf);
4229 }
4231 void Threads::metadata_do(void f(Metadata*)) {
4232 ALL_JAVA_THREADS(p) {
4233 p->metadata_do(f);
4234 }
4235 }
4237 void Threads::gc_epilogue() {
4238 ALL_JAVA_THREADS(p) {
4239 p->gc_epilogue();
4240 }
4241 }
4243 void Threads::gc_prologue() {
4244 ALL_JAVA_THREADS(p) {
4245 p->gc_prologue();
4246 }
4247 }
4249 void Threads::deoptimized_wrt_marked_nmethods() {
4250 ALL_JAVA_THREADS(p) {
4251 p->deoptimized_wrt_marked_nmethods();
4252 }
4253 }
4256 // Get count Java threads that are waiting to enter the specified monitor.
4257 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
4258 address monitor, bool doLock) {
4259 assert(doLock || SafepointSynchronize::is_at_safepoint(),
4260 "must grab Threads_lock or be at safepoint");
4261 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
4263 int i = 0;
4264 {
4265 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4266 ALL_JAVA_THREADS(p) {
4267 if (p->is_Compiler_thread()) continue;
4269 address pending = (address)p->current_pending_monitor();
4270 if (pending == monitor) { // found a match
4271 if (i < count) result->append(p); // save the first count matches
4272 i++;
4273 }
4274 }
4275 }
4276 return result;
4277 }
4280 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
4281 assert(doLock ||
4282 Threads_lock->owned_by_self() ||
4283 SafepointSynchronize::is_at_safepoint(),
4284 "must grab Threads_lock or be at safepoint");
4286 // NULL owner means not locked so we can skip the search
4287 if (owner == NULL) return NULL;
4289 {
4290 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4291 ALL_JAVA_THREADS(p) {
4292 // first, see if owner is the address of a Java thread
4293 if (owner == (address)p) return p;
4294 }
4295 }
4296 // Cannot assert on lack of success here since this function may be
4297 // used by code that is trying to report useful problem information
4298 // like deadlock detection.
4299 if (UseHeavyMonitors) return NULL;
4301 //
4302 // If we didn't find a matching Java thread and we didn't force use of
4303 // heavyweight monitors, then the owner is the stack address of the
4304 // Lock Word in the owning Java thread's stack.
4305 //
4306 JavaThread* the_owner = NULL;
4307 {
4308 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4309 ALL_JAVA_THREADS(q) {
4310 if (q->is_lock_owned(owner)) {
4311 the_owner = q;
4312 break;
4313 }
4314 }
4315 }
4316 // cannot assert on lack of success here; see above comment
4317 return the_owner;
4318 }
4320 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
4321 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
4322 char buf[32];
4323 st->print_cr("%s", os::local_time_string(buf, sizeof(buf)));
4325 st->print_cr("Full thread dump %s (%s %s):",
4326 Abstract_VM_Version::vm_name(),
4327 Abstract_VM_Version::vm_release(),
4328 Abstract_VM_Version::vm_info_string()
4329 );
4330 st->cr();
4332 #if INCLUDE_ALL_GCS
4333 // Dump concurrent locks
4334 ConcurrentLocksDump concurrent_locks;
4335 if (print_concurrent_locks) {
4336 concurrent_locks.dump_at_safepoint();
4337 }
4338 #endif // INCLUDE_ALL_GCS
4340 ALL_JAVA_THREADS(p) {
4341 ResourceMark rm;
4342 p->print_on(st);
4343 if (print_stacks) {
4344 if (internal_format) {
4345 p->trace_stack();
4346 } else {
4347 p->print_stack_on(st);
4348 }
4349 }
4350 st->cr();
4351 #if INCLUDE_ALL_GCS
4352 if (print_concurrent_locks) {
4353 concurrent_locks.print_locks_on(p, st);
4354 }
4355 #endif // INCLUDE_ALL_GCS
4356 }
4358 VMThread::vm_thread()->print_on(st);
4359 st->cr();
4360 Universe::heap()->print_gc_threads_on(st);
4361 WatcherThread* wt = WatcherThread::watcher_thread();
4362 if (wt != NULL) {
4363 wt->print_on(st);
4364 st->cr();
4365 }
4366 CompileBroker::print_compiler_threads_on(st);
4367 st->flush();
4368 }
4370 // Threads::print_on_error() is called by fatal error handler. It's possible
4371 // that VM is not at safepoint and/or current thread is inside signal handler.
4372 // Don't print stack trace, as the stack may not be walkable. Don't allocate
4373 // memory (even in resource area), it might deadlock the error handler.
4374 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
4375 bool found_current = false;
4376 st->print_cr("Java Threads: ( => current thread )");
4377 ALL_JAVA_THREADS(thread) {
4378 bool is_current = (current == thread);
4379 found_current = found_current || is_current;
4381 st->print("%s", is_current ? "=>" : " ");
4383 st->print(PTR_FORMAT, thread);
4384 st->print(" ");
4385 thread->print_on_error(st, buf, buflen);
4386 st->cr();
4387 }
4388 st->cr();
4390 st->print_cr("Other Threads:");
4391 if (VMThread::vm_thread()) {
4392 bool is_current = (current == VMThread::vm_thread());
4393 found_current = found_current || is_current;
4394 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
4396 st->print(PTR_FORMAT, VMThread::vm_thread());
4397 st->print(" ");
4398 VMThread::vm_thread()->print_on_error(st, buf, buflen);
4399 st->cr();
4400 }
4401 WatcherThread* wt = WatcherThread::watcher_thread();
4402 if (wt != NULL) {
4403 bool is_current = (current == wt);
4404 found_current = found_current || is_current;
4405 st->print("%s", is_current ? "=>" : " ");
4407 st->print(PTR_FORMAT, wt);
4408 st->print(" ");
4409 wt->print_on_error(st, buf, buflen);
4410 st->cr();
4411 }
4412 if (!found_current) {
4413 st->cr();
4414 st->print("=>" PTR_FORMAT " (exited) ", current);
4415 current->print_on_error(st, buf, buflen);
4416 st->cr();
4417 }
4418 }
4420 // Internal SpinLock and Mutex
4421 // Based on ParkEvent
4423 // Ad-hoc mutual exclusion primitives: SpinLock and Mux
4424 //
4425 // We employ SpinLocks _only for low-contention, fixed-length
4426 // short-duration critical sections where we're concerned
4427 // about native mutex_t or HotSpot Mutex:: latency.
4428 // The mux construct provides a spin-then-block mutual exclusion
4429 // mechanism.
4430 //
4431 // Testing has shown that contention on the ListLock guarding gFreeList
4432 // is common. If we implement ListLock as a simple SpinLock it's common
4433 // for the JVM to devolve to yielding with little progress. This is true
4434 // despite the fact that the critical sections protected by ListLock are
4435 // extremely short.
4436 //
4437 // TODO-FIXME: ListLock should be of type SpinLock.
4438 // We should make this a 1st-class type, integrated into the lock
4439 // hierarchy as leaf-locks. Critically, the SpinLock structure
4440 // should have sufficient padding to avoid false-sharing and excessive
4441 // cache-coherency traffic.
4444 typedef volatile int SpinLockT ;
4446 void Thread::SpinAcquire (volatile int * adr, const char * LockName) {
4447 if (Atomic::cmpxchg (1, adr, 0) == 0) {
4448 return ; // normal fast-path return
4449 }
4451 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
4452 TEVENT (SpinAcquire - ctx) ;
4453 int ctr = 0 ;
4454 int Yields = 0 ;
4455 for (;;) {
4456 while (*adr != 0) {
4457 ++ctr ;
4458 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
4459 if (Yields > 5) {
4460 os::naked_short_sleep(1);
4461 } else {
4462 os::NakedYield() ;
4463 ++Yields ;
4464 }
4465 } else {
4466 SpinPause() ;
4467 }
4468 }
4469 if (Atomic::cmpxchg (1, adr, 0) == 0) return ;
4470 }
4471 }
4473 void Thread::SpinRelease (volatile int * adr) {
4474 assert (*adr != 0, "invariant") ;
4475 OrderAccess::fence() ; // guarantee at least release consistency.
4476 // Roach-motel semantics.
4477 // It's safe if subsequent LDs and STs float "up" into the critical section,
4478 // but prior LDs and STs within the critical section can't be allowed
4479 // to reorder or float past the ST that releases the lock.
4480 *adr = 0 ;
4481 }
4483 // muxAcquire and muxRelease:
4484 //
4485 // * muxAcquire and muxRelease support a single-word lock-word construct.
4486 // The LSB of the word is set IFF the lock is held.
4487 // The remainder of the word points to the head of a singly-linked list
4488 // of threads blocked on the lock.
4489 //
4490 // * The current implementation of muxAcquire-muxRelease uses its own
4491 // dedicated Thread._MuxEvent instance. If we're interested in
4492 // minimizing the peak number of extant ParkEvent instances then
4493 // we could eliminate _MuxEvent and "borrow" _ParkEvent as long
4494 // as certain invariants were satisfied. Specifically, care would need
4495 // to be taken with regards to consuming unpark() "permits".
4496 // A safe rule of thumb is that a thread would never call muxAcquire()
4497 // if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently
4498 // park(). Otherwise the _ParkEvent park() operation in muxAcquire() could
4499 // consume an unpark() permit intended for monitorenter, for instance.
4500 // One way around this would be to widen the restricted-range semaphore
4501 // implemented in park(). Another alternative would be to provide
4502 // multiple instances of the PlatformEvent() for each thread. One
4503 // instance would be dedicated to muxAcquire-muxRelease, for instance.
4504 //
4505 // * Usage:
4506 // -- Only as leaf locks
4507 // -- for short-term locking only as muxAcquire does not perform
4508 // thread state transitions.
4509 //
4510 // Alternatives:
4511 // * We could implement muxAcquire and muxRelease with MCS or CLH locks
4512 // but with parking or spin-then-park instead of pure spinning.
4513 // * Use Taura-Oyama-Yonenzawa locks.
4514 // * It's possible to construct a 1-0 lock if we encode the lockword as
4515 // (List,LockByte). Acquire will CAS the full lockword while Release
4516 // will STB 0 into the LockByte. The 1-0 scheme admits stranding, so
4517 // acquiring threads use timers (ParkTimed) to detect and recover from
4518 // the stranding window. Thread/Node structures must be aligned on 256-byte
4519 // boundaries by using placement-new.
4520 // * Augment MCS with advisory back-link fields maintained with CAS().
4521 // Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner.
4522 // The validity of the backlinks must be ratified before we trust the value.
4523 // If the backlinks are invalid the exiting thread must back-track through the
4524 // the forward links, which are always trustworthy.
4525 // * Add a successor indication. The LockWord is currently encoded as
4526 // (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable
4527 // to provide the usual futile-wakeup optimization.
4528 // See RTStt for details.
4529 // * Consider schedctl.sc_nopreempt to cover the critical section.
4530 //
4533 typedef volatile intptr_t MutexT ; // Mux Lock-word
4534 enum MuxBits { LOCKBIT = 1 } ;
4536 void Thread::muxAcquire (volatile intptr_t * Lock, const char * LockName) {
4537 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4538 if (w == 0) return ;
4539 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4540 return ;
4541 }
4543 TEVENT (muxAcquire - Contention) ;
4544 ParkEvent * const Self = Thread::current()->_MuxEvent ;
4545 assert ((intptr_t(Self) & LOCKBIT) == 0, "invariant") ;
4546 for (;;) {
4547 int its = (os::is_MP() ? 100 : 0) + 1 ;
4549 // Optional spin phase: spin-then-park strategy
4550 while (--its >= 0) {
4551 w = *Lock ;
4552 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4553 return ;
4554 }
4555 }
4557 Self->reset() ;
4558 Self->OnList = intptr_t(Lock) ;
4559 // The following fence() isn't _strictly necessary as the subsequent
4560 // CAS() both serializes execution and ratifies the fetched *Lock value.
4561 OrderAccess::fence();
4562 for (;;) {
4563 w = *Lock ;
4564 if ((w & LOCKBIT) == 0) {
4565 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4566 Self->OnList = 0 ; // hygiene - allows stronger asserts
4567 return ;
4568 }
4569 continue ; // Interference -- *Lock changed -- Just retry
4570 }
4571 assert (w & LOCKBIT, "invariant") ;
4572 Self->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4573 if (Atomic::cmpxchg_ptr (intptr_t(Self)|LOCKBIT, Lock, w) == w) break ;
4574 }
4576 while (Self->OnList != 0) {
4577 Self->park() ;
4578 }
4579 }
4580 }
4582 void Thread::muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) {
4583 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4584 if (w == 0) return ;
4585 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4586 return ;
4587 }
4589 TEVENT (muxAcquire - Contention) ;
4590 ParkEvent * ReleaseAfter = NULL ;
4591 if (ev == NULL) {
4592 ev = ReleaseAfter = ParkEvent::Allocate (NULL) ;
4593 }
4594 assert ((intptr_t(ev) & LOCKBIT) == 0, "invariant") ;
4595 for (;;) {
4596 guarantee (ev->OnList == 0, "invariant") ;
4597 int its = (os::is_MP() ? 100 : 0) + 1 ;
4599 // Optional spin phase: spin-then-park strategy
4600 while (--its >= 0) {
4601 w = *Lock ;
4602 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4603 if (ReleaseAfter != NULL) {
4604 ParkEvent::Release (ReleaseAfter) ;
4605 }
4606 return ;
4607 }
4608 }
4610 ev->reset() ;
4611 ev->OnList = intptr_t(Lock) ;
4612 // The following fence() isn't _strictly necessary as the subsequent
4613 // CAS() both serializes execution and ratifies the fetched *Lock value.
4614 OrderAccess::fence();
4615 for (;;) {
4616 w = *Lock ;
4617 if ((w & LOCKBIT) == 0) {
4618 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4619 ev->OnList = 0 ;
4620 // We call ::Release while holding the outer lock, thus
4621 // artificially lengthening the critical section.
4622 // Consider deferring the ::Release() until the subsequent unlock(),
4623 // after we've dropped the outer lock.
4624 if (ReleaseAfter != NULL) {
4625 ParkEvent::Release (ReleaseAfter) ;
4626 }
4627 return ;
4628 }
4629 continue ; // Interference -- *Lock changed -- Just retry
4630 }
4631 assert (w & LOCKBIT, "invariant") ;
4632 ev->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4633 if (Atomic::cmpxchg_ptr (intptr_t(ev)|LOCKBIT, Lock, w) == w) break ;
4634 }
4636 while (ev->OnList != 0) {
4637 ev->park() ;
4638 }
4639 }
4640 }
4642 // Release() must extract a successor from the list and then wake that thread.
4643 // It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme
4644 // similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based
4645 // Release() would :
4646 // (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list.
4647 // (B) Extract a successor from the private list "in-hand"
4648 // (C) attempt to CAS() the residual back into *Lock over null.
4649 // If there were any newly arrived threads and the CAS() would fail.
4650 // In that case Release() would detach the RATs, re-merge the list in-hand
4651 // with the RATs and repeat as needed. Alternately, Release() might
4652 // detach and extract a successor, but then pass the residual list to the wakee.
4653 // The wakee would be responsible for reattaching and remerging before it
4654 // competed for the lock.
4655 //
4656 // Both "pop" and DMR are immune from ABA corruption -- there can be
4657 // multiple concurrent pushers, but only one popper or detacher.
4658 // This implementation pops from the head of the list. This is unfair,
4659 // but tends to provide excellent throughput as hot threads remain hot.
4660 // (We wake recently run threads first).
4662 void Thread::muxRelease (volatile intptr_t * Lock) {
4663 for (;;) {
4664 const intptr_t w = Atomic::cmpxchg_ptr (0, Lock, LOCKBIT) ;
4665 assert (w & LOCKBIT, "invariant") ;
4666 if (w == LOCKBIT) return ;
4667 ParkEvent * List = (ParkEvent *) (w & ~LOCKBIT) ;
4668 assert (List != NULL, "invariant") ;
4669 assert (List->OnList == intptr_t(Lock), "invariant") ;
4670 ParkEvent * nxt = List->ListNext ;
4672 // The following CAS() releases the lock and pops the head element.
4673 if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) {
4674 continue ;
4675 }
4676 List->OnList = 0 ;
4677 OrderAccess::fence() ;
4678 List->unpark () ;
4679 return ;
4680 }
4681 }
4684 void Threads::verify() {
4685 ALL_JAVA_THREADS(p) {
4686 p->verify();
4687 }
4688 VMThread* thread = VMThread::vm_thread();
4689 if (thread != NULL) thread->verify();
4690 }