1 /*
2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/moduleEntry.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "code/codeCache.hpp"
32 #include "code/scopeDesc.hpp"
33 #include "compiler/compileBroker.hpp"
34 #include "compiler/compileTask.hpp"
35 #include "gc/shared/gcId.hpp"
36 #include "gc/shared/gcLocker.inline.hpp"
37 #include "gc/shared/workgroup.hpp"
38 #include "interpreter/interpreter.hpp"
39 #include "interpreter/linkResolver.hpp"
40 #include "interpreter/oopMapCache.hpp"
41 #include "jvmtifiles/jvmtiEnv.hpp"
42 #include "logging/log.hpp"
43 #include "logging/logConfiguration.hpp"
44 #include "memory/metaspaceShared.hpp"
45 #include "memory/oopFactory.hpp"
46 #include "memory/resourceArea.hpp"
47 #include "memory/universe.inline.hpp"
48 #include "oops/instanceKlass.hpp"
49 #include "oops/objArrayOop.hpp"
50 #include "oops/oop.inline.hpp"
51 #include "oops/symbol.hpp"
52 #include "oops/verifyOopClosure.hpp"
53 #include "prims/jvm.h"
54 #include "prims/jvm_misc.hpp"
55 #include "prims/jvmtiExport.hpp"
56 #include "prims/jvmtiThreadState.hpp"
57 #include "prims/privilegedStack.hpp"
58 #include "runtime/arguments.hpp"
59 #include "runtime/atomic.hpp"
60 #include "runtime/biasedLocking.hpp"
61 #include "runtime/commandLineFlagConstraintList.hpp"
62 #include "runtime/commandLineFlagWriteableList.hpp"
63 #include "runtime/commandLineFlagRangeList.hpp"
64 #include "runtime/deoptimization.hpp"
65 #include "runtime/frame.inline.hpp"
66 #include "runtime/globals.hpp"
67 #include "runtime/init.hpp"
68 #include "runtime/interfaceSupport.hpp"
69 #include "runtime/java.hpp"
70 #include "runtime/javaCalls.hpp"
71 #include "runtime/jniPeriodicChecker.hpp"
72 #include "runtime/timerTrace.hpp"
73 #include "runtime/memprofiler.hpp"
74 #include "runtime/mutexLocker.hpp"
75 #include "runtime/objectMonitor.hpp"
76 #include "runtime/orderAccess.inline.hpp"
77 #include "runtime/osThread.hpp"
78 #include "runtime/safepoint.hpp"
79 #include "runtime/sharedRuntime.hpp"
80 #include "runtime/statSampler.hpp"
81 #include "runtime/stubRoutines.hpp"
82 #include "runtime/sweeper.hpp"
83 #include "runtime/task.hpp"
84 #include "runtime/thread.inline.hpp"
85 #include "runtime/threadCritical.hpp"
86 #include "runtime/vframe.hpp"
87 #include "runtime/vframeArray.hpp"
88 #include "runtime/vframe_hp.hpp"
89 #include "runtime/vmThread.hpp"
90 #include "runtime/vm_operations.hpp"
91 #include "runtime/vm_version.hpp"
92 #include "services/attachListener.hpp"
93 #include "services/management.hpp"
94 #include "services/memTracker.hpp"
95 #include "services/threadService.hpp"
96 #include "trace/traceMacros.hpp"
97 #include "trace/tracing.hpp"
98 #include "utilities/align.hpp"
99 #include "utilities/defaultStream.hpp"
100 #include "utilities/dtrace.hpp"
101 #include "utilities/events.hpp"
102 #include "utilities/macros.hpp"
103 #include "utilities/preserveException.hpp"
104 #include "utilities/vmError.hpp"
105 #if INCLUDE_ALL_GCS
106 #include "gc/cms/concurrentMarkSweepThread.hpp"
107 #include "gc/g1/concurrentMarkThread.inline.hpp"
108 #include "gc/parallel/pcTasks.hpp"
109 #endif // INCLUDE_ALL_GCS
110 #if INCLUDE_JVMCI
111 #include "jvmci/jvmciCompiler.hpp"
112 #include "jvmci/jvmciRuntime.hpp"
113 #endif
114 #ifdef COMPILER1
115 #include "c1/c1_Compiler.hpp"
116 #endif
117 #ifdef COMPILER2
118 #include "opto/c2compiler.hpp"
119 #include "opto/idealGraphPrinter.hpp"
120 #endif
121 #if INCLUDE_RTM_OPT
122 #include "runtime/rtmLocking.hpp"
123 #endif
124
125 // Initialization after module runtime initialization
126 void universe_post_module_init(); // must happen after call_initPhase2
127
128 #ifdef DTRACE_ENABLED
129
130 // Only bother with this argument setup if dtrace is available
131
132 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
133 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
134
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 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
142 (char *) name, len, \
143 java_lang_Thread::thread_id((javathread)->threadObj()), \
144 (uintptr_t) (javathread)->osthread()->thread_id(), \
145 java_lang_Thread::is_daemon((javathread)->threadObj())); \
146 }
147
148 #else // ndef DTRACE_ENABLED
149
150 #define DTRACE_THREAD_PROBE(probe, javathread)
151
152 #endif // ndef DTRACE_ENABLED
153
154 #ifndef USE_LIBRARY_BASED_TLS_ONLY
155 // Current thread is maintained as a thread-local variable
156 THREAD_LOCAL_DECL Thread* Thread::_thr_current = NULL;
157 #endif
158 // Class hierarchy
159 // - Thread
160 // - VMThread
161 // - WatcherThread
162 // - ConcurrentMarkSweepThread
163 // - JavaThread
164 // - CompilerThread
165
166 // ======= Thread ========
167 // Support for forcing alignment of thread objects for biased locking
168 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
169 if (UseBiasedLocking) {
170 const int alignment = markOopDesc::biased_lock_alignment;
171 size_t aligned_size = size + (alignment - sizeof(intptr_t));
172 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
173 : AllocateHeap(aligned_size, flags, CURRENT_PC,
174 AllocFailStrategy::RETURN_NULL);
175 void* aligned_addr = align_up(real_malloc_addr, alignment);
176 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
177 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
178 "JavaThread alignment code overflowed allocated storage");
179 if (aligned_addr != real_malloc_addr) {
180 log_info(biasedlocking)("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
181 p2i(real_malloc_addr),
182 p2i(aligned_addr));
183 }
184 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
185 return aligned_addr;
186 } else {
187 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
188 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
189 }
190 }
191
192 void Thread::operator delete(void* p) {
193 if (UseBiasedLocking) {
194 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
195 FreeHeap(real_malloc_addr);
196 } else {
197 FreeHeap(p);
198 }
199 }
200
201
202 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
203 // JavaThread
204
205
206 Thread::Thread() {
207 // stack and get_thread
208 set_stack_base(NULL);
209 set_stack_size(0);
210 set_self_raw_id(0);
211 set_lgrp_id(-1);
212 DEBUG_ONLY(clear_suspendible_thread();)
213
214 // allocated data structures
215 set_osthread(NULL);
216 set_resource_area(new (mtThread)ResourceArea());
217 DEBUG_ONLY(_current_resource_mark = NULL;)
218 set_handle_area(new (mtThread) HandleArea(NULL));
219 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, true));
220 set_active_handles(NULL);
221 set_free_handle_block(NULL);
222 set_last_handle_mark(NULL);
223
224 // This initial value ==> never claimed.
225 _oops_do_parity = 0;
226
227 // the handle mark links itself to last_handle_mark
228 new HandleMark(this);
229
230 // plain initialization
231 debug_only(_owned_locks = NULL;)
232 debug_only(_allow_allocation_count = 0;)
233 NOT_PRODUCT(_allow_safepoint_count = 0;)
234 NOT_PRODUCT(_skip_gcalot = false;)
235 _jvmti_env_iteration_count = 0;
236 set_allocated_bytes(0);
237 _vm_operation_started_count = 0;
238 _vm_operation_completed_count = 0;
239 _current_pending_monitor = NULL;
240 _current_pending_monitor_is_from_java = true;
241 _current_waiting_monitor = NULL;
242 _num_nested_signal = 0;
243 omFreeList = NULL;
244 omFreeCount = 0;
245 omFreeProvision = 32;
246 omInUseList = NULL;
247 omInUseCount = 0;
248
249 #ifdef ASSERT
250 _visited_for_critical_count = false;
251 #endif
252
253 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true,
254 Monitor::_safepoint_check_sometimes);
255 _suspend_flags = 0;
256
257 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
258 _hashStateX = os::random();
259 _hashStateY = 842502087;
260 _hashStateZ = 0x8767; // (int)(3579807591LL & 0xffff) ;
261 _hashStateW = 273326509;
262
263 _OnTrap = 0;
264 _schedctl = NULL;
265 _Stalled = 0;
266 _TypeTag = 0x2BAD;
267
268 // Many of the following fields are effectively final - immutable
269 // Note that nascent threads can't use the Native Monitor-Mutex
270 // construct until the _MutexEvent is initialized ...
271 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
272 // we might instead use a stack of ParkEvents that we could provision on-demand.
273 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
274 // and ::Release()
275 _ParkEvent = ParkEvent::Allocate(this);
276 _SleepEvent = ParkEvent::Allocate(this);
277 _MutexEvent = ParkEvent::Allocate(this);
278 _MuxEvent = ParkEvent::Allocate(this);
279
280 #ifdef CHECK_UNHANDLED_OOPS
281 if (CheckUnhandledOops) {
282 _unhandled_oops = new UnhandledOops(this);
283 }
284 #endif // CHECK_UNHANDLED_OOPS
285 #ifdef ASSERT
286 if (UseBiasedLocking) {
287 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
288 assert(this == _real_malloc_address ||
289 this == align_up(_real_malloc_address, (int)markOopDesc::biased_lock_alignment),
290 "bug in forced alignment of thread objects");
291 }
292 #endif // ASSERT
293 }
294
295 void Thread::initialize_thread_current() {
296 #ifndef USE_LIBRARY_BASED_TLS_ONLY
297 assert(_thr_current == NULL, "Thread::current already initialized");
298 _thr_current = this;
299 #endif
300 assert(ThreadLocalStorage::thread() == NULL, "ThreadLocalStorage::thread already initialized");
301 ThreadLocalStorage::set_thread(this);
302 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
303 }
304
305 void Thread::clear_thread_current() {
306 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
307 #ifndef USE_LIBRARY_BASED_TLS_ONLY
308 _thr_current = NULL;
309 #endif
310 ThreadLocalStorage::set_thread(NULL);
311 }
312
313 void Thread::record_stack_base_and_size() {
314 set_stack_base(os::current_stack_base());
315 set_stack_size(os::current_stack_size());
316 // CR 7190089: on Solaris, primordial thread's stack is adjusted
317 // in initialize_thread(). Without the adjustment, stack size is
318 // incorrect if stack is set to unlimited (ulimit -s unlimited).
319 // So far, only Solaris has real implementation of initialize_thread().
320 //
321 // set up any platform-specific state.
322 os::initialize_thread(this);
323
324 // Set stack limits after thread is initialized.
325 if (is_Java_thread()) {
326 ((JavaThread*) this)->set_stack_overflow_limit();
327 ((JavaThread*) this)->set_reserved_stack_activation(stack_base());
328 }
329 #if INCLUDE_NMT
330 // record thread's native stack, stack grows downward
331 MemTracker::record_thread_stack(stack_end(), stack_size());
332 #endif // INCLUDE_NMT
333 log_debug(os, thread)("Thread " UINTX_FORMAT " stack dimensions: "
334 PTR_FORMAT "-" PTR_FORMAT " (" SIZE_FORMAT "k).",
335 os::current_thread_id(), p2i(stack_base() - stack_size()),
336 p2i(stack_base()), stack_size()/1024);
337 }
338
339
340 Thread::~Thread() {
341 EVENT_THREAD_DESTRUCT(this);
342
343 // stack_base can be NULL if the thread is never started or exited before
344 // record_stack_base_and_size called. Although, we would like to ensure
345 // that all started threads do call record_stack_base_and_size(), there is
346 // not proper way to enforce that.
347 #if INCLUDE_NMT
348 if (_stack_base != NULL) {
349 MemTracker::release_thread_stack(stack_end(), stack_size());
350 #ifdef ASSERT
351 set_stack_base(NULL);
352 #endif
353 }
354 #endif // INCLUDE_NMT
355
356 // deallocate data structures
357 delete resource_area();
358 // since the handle marks are using the handle area, we have to deallocated the root
359 // handle mark before deallocating the thread's handle area,
360 assert(last_handle_mark() != NULL, "check we have an element");
361 delete last_handle_mark();
362 assert(last_handle_mark() == NULL, "check we have reached the end");
363
364 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
365 // We NULL out the fields for good hygiene.
366 ParkEvent::Release(_ParkEvent); _ParkEvent = NULL;
367 ParkEvent::Release(_SleepEvent); _SleepEvent = NULL;
368 ParkEvent::Release(_MutexEvent); _MutexEvent = NULL;
369 ParkEvent::Release(_MuxEvent); _MuxEvent = NULL;
370
371 delete handle_area();
372 delete metadata_handles();
373
374 // SR_handler uses this as a termination indicator -
375 // needs to happen before os::free_thread()
376 delete _SR_lock;
377 _SR_lock = NULL;
378
379 // osthread() can be NULL, if creation of thread failed.
380 if (osthread() != NULL) os::free_thread(osthread());
381
382 // clear Thread::current if thread is deleting itself.
383 // Needed to ensure JNI correctly detects non-attached threads.
384 if (this == Thread::current()) {
385 clear_thread_current();
386 }
387
388 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
389 }
390
391 // NOTE: dummy function for assertion purpose.
392 void Thread::run() {
393 ShouldNotReachHere();
394 }
395
396 #ifdef ASSERT
397 // Private method to check for dangling thread pointer
398 void check_for_dangling_thread_pointer(Thread *thread) {
399 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
400 "possibility of dangling Thread pointer");
401 }
402 #endif
403
404 ThreadPriority Thread::get_priority(const Thread* const thread) {
405 ThreadPriority priority;
406 // Can return an error!
407 (void)os::get_priority(thread, priority);
408 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
409 return priority;
410 }
411
412 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
413 debug_only(check_for_dangling_thread_pointer(thread);)
414 // Can return an error!
415 (void)os::set_priority(thread, priority);
416 }
417
418
419 void Thread::start(Thread* thread) {
420 // Start is different from resume in that its safety is guaranteed by context or
421 // being called from a Java method synchronized on the Thread object.
422 if (!DisableStartThread) {
423 if (thread->is_Java_thread()) {
424 // Initialize the thread state to RUNNABLE before starting this thread.
425 // Can not set it after the thread started because we do not know the
426 // exact thread state at that time. It could be in MONITOR_WAIT or
427 // in SLEEPING or some other state.
428 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
429 java_lang_Thread::RUNNABLE);
430 }
431 os::start_thread(thread);
432 }
433 }
434
435 // Enqueue a VM_Operation to do the job for us - sometime later
436 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
437 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
438 VMThread::execute(vm_stop);
439 }
440
441
442 // Check if an external suspend request has completed (or has been
443 // cancelled). Returns true if the thread is externally suspended and
444 // false otherwise.
445 //
446 // The bits parameter returns information about the code path through
447 // the routine. Useful for debugging:
448 //
449 // set in is_ext_suspend_completed():
450 // 0x00000001 - routine was entered
451 // 0x00000010 - routine return false at end
452 // 0x00000100 - thread exited (return false)
453 // 0x00000200 - suspend request cancelled (return false)
454 // 0x00000400 - thread suspended (return true)
455 // 0x00001000 - thread is in a suspend equivalent state (return true)
456 // 0x00002000 - thread is native and walkable (return true)
457 // 0x00004000 - thread is native_trans and walkable (needed retry)
458 //
459 // set in wait_for_ext_suspend_completion():
460 // 0x00010000 - routine was entered
461 // 0x00020000 - suspend request cancelled before loop (return false)
462 // 0x00040000 - thread suspended before loop (return true)
463 // 0x00080000 - suspend request cancelled in loop (return false)
464 // 0x00100000 - thread suspended in loop (return true)
465 // 0x00200000 - suspend not completed during retry loop (return false)
466
467 // Helper class for tracing suspend wait debug bits.
468 //
469 // 0x00000100 indicates that the target thread exited before it could
470 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
471 // 0x00080000 each indicate a cancelled suspend request so they don't
472 // count as wait failures either.
473 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
474
475 class TraceSuspendDebugBits : public StackObj {
476 private:
477 JavaThread * jt;
478 bool is_wait;
479 bool called_by_wait; // meaningful when !is_wait
480 uint32_t * bits;
481
482 public:
483 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
484 uint32_t *_bits) {
485 jt = _jt;
486 is_wait = _is_wait;
487 called_by_wait = _called_by_wait;
488 bits = _bits;
489 }
490
491 ~TraceSuspendDebugBits() {
492 if (!is_wait) {
493 #if 1
494 // By default, don't trace bits for is_ext_suspend_completed() calls.
495 // That trace is very chatty.
496 return;
497 #else
498 if (!called_by_wait) {
499 // If tracing for is_ext_suspend_completed() is enabled, then only
500 // trace calls to it from wait_for_ext_suspend_completion()
501 return;
502 }
503 #endif
504 }
505
506 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
507 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
508 MutexLocker ml(Threads_lock); // needed for get_thread_name()
509 ResourceMark rm;
510
511 tty->print_cr(
512 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
513 jt->get_thread_name(), *bits);
514
515 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
516 }
517 }
518 }
519 };
520 #undef DEBUG_FALSE_BITS
521
522
523 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay,
524 uint32_t *bits) {
525 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
526
527 bool did_trans_retry = false; // only do thread_in_native_trans retry once
528 bool do_trans_retry; // flag to force the retry
529
530 *bits |= 0x00000001;
531
532 do {
533 do_trans_retry = false;
534
535 if (is_exiting()) {
536 // Thread is in the process of exiting. This is always checked
537 // first to reduce the risk of dereferencing a freed JavaThread.
538 *bits |= 0x00000100;
539 return false;
540 }
541
542 if (!is_external_suspend()) {
543 // Suspend request is cancelled. This is always checked before
544 // is_ext_suspended() to reduce the risk of a rogue resume
545 // confusing the thread that made the suspend request.
546 *bits |= 0x00000200;
547 return false;
548 }
549
550 if (is_ext_suspended()) {
551 // thread is suspended
552 *bits |= 0x00000400;
553 return true;
554 }
555
556 // Now that we no longer do hard suspends of threads running
557 // native code, the target thread can be changing thread state
558 // while we are in this routine:
559 //
560 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
561 //
562 // We save a copy of the thread state as observed at this moment
563 // and make our decision about suspend completeness based on the
564 // copy. This closes the race where the thread state is seen as
565 // _thread_in_native_trans in the if-thread_blocked check, but is
566 // seen as _thread_blocked in if-thread_in_native_trans check.
567 JavaThreadState save_state = thread_state();
568
569 if (save_state == _thread_blocked && is_suspend_equivalent()) {
570 // If the thread's state is _thread_blocked and this blocking
571 // condition is known to be equivalent to a suspend, then we can
572 // consider the thread to be externally suspended. This means that
573 // the code that sets _thread_blocked has been modified to do
574 // self-suspension if the blocking condition releases. We also
575 // used to check for CONDVAR_WAIT here, but that is now covered by
576 // the _thread_blocked with self-suspension check.
577 //
578 // Return true since we wouldn't be here unless there was still an
579 // external suspend request.
580 *bits |= 0x00001000;
581 return true;
582 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
583 // Threads running native code will self-suspend on native==>VM/Java
584 // transitions. If its stack is walkable (should always be the case
585 // unless this function is called before the actual java_suspend()
586 // call), then the wait is done.
587 *bits |= 0x00002000;
588 return true;
589 } else if (!called_by_wait && !did_trans_retry &&
590 save_state == _thread_in_native_trans &&
591 frame_anchor()->walkable()) {
592 // The thread is transitioning from thread_in_native to another
593 // thread state. check_safepoint_and_suspend_for_native_trans()
594 // will force the thread to self-suspend. If it hasn't gotten
595 // there yet we may have caught the thread in-between the native
596 // code check above and the self-suspend. Lucky us. If we were
597 // called by wait_for_ext_suspend_completion(), then it
598 // will be doing the retries so we don't have to.
599 //
600 // Since we use the saved thread state in the if-statement above,
601 // there is a chance that the thread has already transitioned to
602 // _thread_blocked by the time we get here. In that case, we will
603 // make a single unnecessary pass through the logic below. This
604 // doesn't hurt anything since we still do the trans retry.
605
606 *bits |= 0x00004000;
607
608 // Once the thread leaves thread_in_native_trans for another
609 // thread state, we break out of this retry loop. We shouldn't
610 // need this flag to prevent us from getting back here, but
611 // sometimes paranoia is good.
612 did_trans_retry = true;
613
614 // We wait for the thread to transition to a more usable state.
615 for (int i = 1; i <= SuspendRetryCount; i++) {
616 // We used to do an "os::yield_all(i)" call here with the intention
617 // that yielding would increase on each retry. However, the parameter
618 // is ignored on Linux which means the yield didn't scale up. Waiting
619 // on the SR_lock below provides a much more predictable scale up for
620 // the delay. It also provides a simple/direct point to check for any
621 // safepoint requests from the VMThread
622
623 // temporarily drops SR_lock while doing wait with safepoint check
624 // (if we're a JavaThread - the WatcherThread can also call this)
625 // and increase delay with each retry
626 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
627
628 // check the actual thread state instead of what we saved above
629 if (thread_state() != _thread_in_native_trans) {
630 // the thread has transitioned to another thread state so
631 // try all the checks (except this one) one more time.
632 do_trans_retry = true;
633 break;
634 }
635 } // end retry loop
636
637
638 }
639 } while (do_trans_retry);
640
641 *bits |= 0x00000010;
642 return false;
643 }
644
645 // Wait for an external suspend request to complete (or be cancelled).
646 // Returns true if the thread is externally suspended and false otherwise.
647 //
648 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
649 uint32_t *bits) {
650 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
651 false /* !called_by_wait */, bits);
652
653 // local flag copies to minimize SR_lock hold time
654 bool is_suspended;
655 bool pending;
656 uint32_t reset_bits;
657
658 // set a marker so is_ext_suspend_completed() knows we are the caller
659 *bits |= 0x00010000;
660
661 // We use reset_bits to reinitialize the bits value at the top of
662 // each retry loop. This allows the caller to make use of any
663 // unused bits for their own marking purposes.
664 reset_bits = *bits;
665
666 {
667 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
668 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
669 delay, bits);
670 pending = is_external_suspend();
671 }
672 // must release SR_lock to allow suspension to complete
673
674 if (!pending) {
675 // A cancelled suspend request is the only false return from
676 // is_ext_suspend_completed() that keeps us from entering the
677 // retry loop.
678 *bits |= 0x00020000;
679 return false;
680 }
681
682 if (is_suspended) {
683 *bits |= 0x00040000;
684 return true;
685 }
686
687 for (int i = 1; i <= retries; i++) {
688 *bits = reset_bits; // reinit to only track last retry
689
690 // We used to do an "os::yield_all(i)" call here with the intention
691 // that yielding would increase on each retry. However, the parameter
692 // is ignored on Linux which means the yield didn't scale up. Waiting
693 // on the SR_lock below provides a much more predictable scale up for
694 // the delay. It also provides a simple/direct point to check for any
695 // safepoint requests from the VMThread
696
697 {
698 MutexLocker ml(SR_lock());
699 // wait with safepoint check (if we're a JavaThread - the WatcherThread
700 // can also call this) and increase delay with each retry
701 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
702
703 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
704 delay, bits);
705
706 // It is possible for the external suspend request to be cancelled
707 // (by a resume) before the actual suspend operation is completed.
708 // Refresh our local copy to see if we still need to wait.
709 pending = is_external_suspend();
710 }
711
712 if (!pending) {
713 // A cancelled suspend request is the only false return from
714 // is_ext_suspend_completed() that keeps us from staying in the
715 // retry loop.
716 *bits |= 0x00080000;
717 return false;
718 }
719
720 if (is_suspended) {
721 *bits |= 0x00100000;
722 return true;
723 }
724 } // end retry loop
725
726 // thread did not suspend after all our retries
727 *bits |= 0x00200000;
728 return false;
729 }
730
731 #ifndef PRODUCT
732 void JavaThread::record_jump(address target, address instr, const char* file,
733 int line) {
734
735 // This should not need to be atomic as the only way for simultaneous
736 // updates is via interrupts. Even then this should be rare or non-existent
737 // and we don't care that much anyway.
738
739 int index = _jmp_ring_index;
740 _jmp_ring_index = (index + 1) & (jump_ring_buffer_size - 1);
741 _jmp_ring[index]._target = (intptr_t) target;
742 _jmp_ring[index]._instruction = (intptr_t) instr;
743 _jmp_ring[index]._file = file;
744 _jmp_ring[index]._line = line;
745 }
746 #endif // PRODUCT
747
748 void Thread::interrupt(Thread* thread) {
749 debug_only(check_for_dangling_thread_pointer(thread);)
750 os::interrupt(thread);
751 }
752
753 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
754 debug_only(check_for_dangling_thread_pointer(thread);)
755 // Note: If clear_interrupted==false, this simply fetches and
756 // returns the value of the field osthread()->interrupted().
757 return os::is_interrupted(thread, clear_interrupted);
758 }
759
760
761 // GC Support
762 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
763 jint thread_parity = _oops_do_parity;
764 if (thread_parity != strong_roots_parity) {
765 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
766 if (res == thread_parity) {
767 return true;
768 } else {
769 guarantee(res == strong_roots_parity, "Or else what?");
770 return false;
771 }
772 }
773 return false;
774 }
775
776 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
777 active_handles()->oops_do(f);
778 // Do oop for ThreadShadow
779 f->do_oop((oop*)&_pending_exception);
780 handle_area()->oops_do(f);
781
782 if (MonitorInUseLists) {
783 // When using thread local monitor lists, we scan them here,
784 // and the remaining global monitors in ObjectSynchronizer::oops_do().
785 ObjectSynchronizer::thread_local_used_oops_do(this, f);
786 }
787 }
788
789 void Thread::metadata_handles_do(void f(Metadata*)) {
790 // Only walk the Handles in Thread.
791 if (metadata_handles() != NULL) {
792 for (int i = 0; i< metadata_handles()->length(); i++) {
793 f(metadata_handles()->at(i));
794 }
795 }
796 }
797
798 void Thread::print_on(outputStream* st) const {
799 // get_priority assumes osthread initialized
800 if (osthread() != NULL) {
801 int os_prio;
802 if (os::get_native_priority(this, &os_prio) == OS_OK) {
803 st->print("os_prio=%d ", os_prio);
804 }
805 st->print("tid=" INTPTR_FORMAT " ", p2i(this));
806 ext().print_on(st);
807 osthread()->print_on(st);
808 }
809 debug_only(if (WizardMode) print_owned_locks_on(st);)
810 }
811
812 // Thread::print_on_error() is called by fatal error handler. Don't use
813 // any lock or allocate memory.
814 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
815 assert(!(is_Compiler_thread() || is_Java_thread()), "Can't call name() here if it allocates");
816
817 if (is_VM_thread()) { st->print("VMThread"); }
818 else if (is_GC_task_thread()) { st->print("GCTaskThread"); }
819 else if (is_Watcher_thread()) { st->print("WatcherThread"); }
820 else if (is_ConcurrentGC_thread()) { st->print("ConcurrentGCThread"); }
821 else { st->print("Thread"); }
822
823 if (is_Named_thread()) {
824 st->print(" \"%s\"", name());
825 }
826
827 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
828 p2i(stack_end()), p2i(stack_base()));
829
830 if (osthread()) {
831 st->print(" [id=%d]", osthread()->thread_id());
832 }
833 }
834
835 #ifdef ASSERT
836 void Thread::print_owned_locks_on(outputStream* st) const {
837 Monitor *cur = _owned_locks;
838 if (cur == NULL) {
839 st->print(" (no locks) ");
840 } else {
841 st->print_cr(" Locks owned:");
842 while (cur) {
843 cur->print_on(st);
844 cur = cur->next();
845 }
846 }
847 }
848
849 static int ref_use_count = 0;
850
851 bool Thread::owns_locks_but_compiled_lock() const {
852 for (Monitor *cur = _owned_locks; cur; cur = cur->next()) {
853 if (cur != Compile_lock) return true;
854 }
855 return false;
856 }
857
858
859 #endif
860
861 #ifndef PRODUCT
862
863 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
864 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
865 // no threads which allow_vm_block's are held
866 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
867 // Check if current thread is allowed to block at a safepoint
868 if (!(_allow_safepoint_count == 0)) {
869 fatal("Possible safepoint reached by thread that does not allow it");
870 }
871 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
872 fatal("LEAF method calling lock?");
873 }
874
875 #ifdef ASSERT
876 if (potential_vm_operation && is_Java_thread()
877 && !Universe::is_bootstrapping()) {
878 // Make sure we do not hold any locks that the VM thread also uses.
879 // This could potentially lead to deadlocks
880 for (Monitor *cur = _owned_locks; cur; cur = cur->next()) {
881 // Threads_lock is special, since the safepoint synchronization will not start before this is
882 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
883 // since it is used to transfer control between JavaThreads and the VMThread
884 // Do not *exclude* any locks unless you are absolutely sure it is correct. Ask someone else first!
885 if ((cur->allow_vm_block() &&
886 cur != Threads_lock &&
887 cur != Compile_lock && // Temporary: should not be necessary when we get separate compilation
888 cur != VMOperationRequest_lock &&
889 cur != VMOperationQueue_lock) ||
890 cur->rank() == Mutex::special) {
891 fatal("Thread holding lock at safepoint that vm can block on: %s", cur->name());
892 }
893 }
894 }
895
896 if (GCALotAtAllSafepoints) {
897 // We could enter a safepoint here and thus have a gc
898 InterfaceSupport::check_gc_alot();
899 }
900 #endif
901 }
902 #endif
903
904 bool Thread::is_in_stack(address adr) const {
905 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
906 address end = os::current_stack_pointer();
907 // Allow non Java threads to call this without stack_base
908 if (_stack_base == NULL) return true;
909 if (stack_base() >= adr && adr >= end) return true;
910
911 return false;
912 }
913
914 bool Thread::is_in_usable_stack(address adr) const {
915 size_t stack_guard_size = os::uses_stack_guard_pages() ? JavaThread::stack_guard_zone_size() : 0;
916 size_t usable_stack_size = _stack_size - stack_guard_size;
917
918 return ((adr < stack_base()) && (adr >= stack_base() - usable_stack_size));
919 }
920
921
922 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
923 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
924 // used for compilation in the future. If that change is made, the need for these methods
925 // should be revisited, and they should be removed if possible.
926
927 bool Thread::is_lock_owned(address adr) const {
928 return on_local_stack(adr);
929 }
930
931 bool Thread::set_as_starting_thread() {
932 // NOTE: this must be called inside the main thread.
933 return os::create_main_thread((JavaThread*)this);
934 }
935
936 static void initialize_class(Symbol* class_name, TRAPS) {
937 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
938 InstanceKlass::cast(klass)->initialize(CHECK);
939 }
940
941
942 // Creates the initial ThreadGroup
943 static Handle create_initial_thread_group(TRAPS) {
944 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
945 InstanceKlass* ik = InstanceKlass::cast(k);
946
947 Handle system_instance = ik->allocate_instance_handle(CHECK_NH);
948 {
949 JavaValue result(T_VOID);
950 JavaCalls::call_special(&result,
951 system_instance,
952 ik,
953 vmSymbols::object_initializer_name(),
954 vmSymbols::void_method_signature(),
955 CHECK_NH);
956 }
957 Universe::set_system_thread_group(system_instance());
958
959 Handle main_instance = ik->allocate_instance_handle(CHECK_NH);
960 {
961 JavaValue result(T_VOID);
962 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
963 JavaCalls::call_special(&result,
964 main_instance,
965 ik,
966 vmSymbols::object_initializer_name(),
967 vmSymbols::threadgroup_string_void_signature(),
968 system_instance,
969 string,
970 CHECK_NH);
971 }
972 return main_instance;
973 }
974
975 // Creates the initial Thread
976 static oop create_initial_thread(Handle thread_group, JavaThread* thread,
977 TRAPS) {
978 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
979 InstanceKlass* ik = InstanceKlass::cast(k);
980 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK_NULL);
981
982 java_lang_Thread::set_thread(thread_oop(), thread);
983 java_lang_Thread::set_priority(thread_oop(), NormPriority);
984 thread->set_threadObj(thread_oop());
985
986 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
987
988 JavaValue result(T_VOID);
989 JavaCalls::call_special(&result, thread_oop,
990 ik,
991 vmSymbols::object_initializer_name(),
992 vmSymbols::threadgroup_string_void_signature(),
993 thread_group,
994 string,
995 CHECK_NULL);
996 return thread_oop();
997 }
998
999 char java_runtime_name[128] = "";
1000 char java_runtime_version[128] = "";
1001
1002 // extract the JRE name from java.lang.VersionProps.java_runtime_name
1003 static const char* get_java_runtime_name(TRAPS) {
1004 Klass* k = SystemDictionary::find(vmSymbols::java_lang_VersionProps(),
1005 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1006 fieldDescriptor fd;
1007 bool found = k != NULL &&
1008 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(),
1009 vmSymbols::string_signature(), &fd);
1010 if (found) {
1011 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1012 if (name_oop == NULL) {
1013 return NULL;
1014 }
1015 const char* name = java_lang_String::as_utf8_string(name_oop,
1016 java_runtime_name,
1017 sizeof(java_runtime_name));
1018 return name;
1019 } else {
1020 return NULL;
1021 }
1022 }
1023
1024 // extract the JRE version from java.lang.VersionProps.java_runtime_version
1025 static const char* get_java_runtime_version(TRAPS) {
1026 Klass* k = SystemDictionary::find(vmSymbols::java_lang_VersionProps(),
1027 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1028 fieldDescriptor fd;
1029 bool found = k != NULL &&
1030 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_version_name(),
1031 vmSymbols::string_signature(), &fd);
1032 if (found) {
1033 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1034 if (name_oop == NULL) {
1035 return NULL;
1036 }
1037 const char* name = java_lang_String::as_utf8_string(name_oop,
1038 java_runtime_version,
1039 sizeof(java_runtime_version));
1040 return name;
1041 } else {
1042 return NULL;
1043 }
1044 }
1045
1046 // General purpose hook into Java code, run once when the VM is initialized.
1047 // The Java library method itself may be changed independently from the VM.
1048 static void call_postVMInitHook(TRAPS) {
1049 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
1050 if (klass != NULL) {
1051 JavaValue result(T_VOID);
1052 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
1053 vmSymbols::void_method_signature(),
1054 CHECK);
1055 }
1056 }
1057
1058 static void reset_vm_info_property(TRAPS) {
1059 // the vm info string
1060 ResourceMark rm(THREAD);
1061 const char *vm_info = VM_Version::vm_info_string();
1062
1063 // java.lang.System class
1064 Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1065
1066 // setProperty arguments
1067 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
1068 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
1069
1070 // return value
1071 JavaValue r(T_OBJECT);
1072
1073 // public static String setProperty(String key, String value);
1074 JavaCalls::call_static(&r,
1075 klass,
1076 vmSymbols::setProperty_name(),
1077 vmSymbols::string_string_string_signature(),
1078 key_str,
1079 value_str,
1080 CHECK);
1081 }
1082
1083
1084 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
1085 bool daemon, TRAPS) {
1086 assert(thread_group.not_null(), "thread group should be specified");
1087 assert(threadObj() == NULL, "should only create Java thread object once");
1088
1089 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
1090 InstanceKlass* ik = InstanceKlass::cast(k);
1091 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
1092
1093 java_lang_Thread::set_thread(thread_oop(), this);
1094 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1095 set_threadObj(thread_oop());
1096
1097 JavaValue result(T_VOID);
1098 if (thread_name != NULL) {
1099 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
1100 // Thread gets assigned specified name and null target
1101 JavaCalls::call_special(&result,
1102 thread_oop,
1103 ik,
1104 vmSymbols::object_initializer_name(),
1105 vmSymbols::threadgroup_string_void_signature(),
1106 thread_group, // Argument 1
1107 name, // Argument 2
1108 THREAD);
1109 } else {
1110 // Thread gets assigned name "Thread-nnn" and null target
1111 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
1112 JavaCalls::call_special(&result,
1113 thread_oop,
1114 ik,
1115 vmSymbols::object_initializer_name(),
1116 vmSymbols::threadgroup_runnable_void_signature(),
1117 thread_group, // Argument 1
1118 Handle(), // Argument 2
1119 THREAD);
1120 }
1121
1122
1123 if (daemon) {
1124 java_lang_Thread::set_daemon(thread_oop());
1125 }
1126
1127 if (HAS_PENDING_EXCEPTION) {
1128 return;
1129 }
1130
1131 Klass* group = SystemDictionary::ThreadGroup_klass();
1132 Handle threadObj(THREAD, this->threadObj());
1133
1134 JavaCalls::call_special(&result,
1135 thread_group,
1136 group,
1137 vmSymbols::add_method_name(),
1138 vmSymbols::thread_void_signature(),
1139 threadObj, // Arg 1
1140 THREAD);
1141 }
1142
1143 // NamedThread -- non-JavaThread subclasses with multiple
1144 // uniquely named instances should derive from this.
1145 NamedThread::NamedThread() : Thread() {
1146 _name = NULL;
1147 _processed_thread = NULL;
1148 _gc_id = GCId::undefined();
1149 }
1150
1151 NamedThread::~NamedThread() {
1152 if (_name != NULL) {
1153 FREE_C_HEAP_ARRAY(char, _name);
1154 _name = NULL;
1155 }
1156 }
1157
1158 void NamedThread::set_name(const char* format, ...) {
1159 guarantee(_name == NULL, "Only get to set name once.");
1160 _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);
1161 guarantee(_name != NULL, "alloc failure");
1162 va_list ap;
1163 va_start(ap, format);
1164 jio_vsnprintf(_name, max_name_len, format, ap);
1165 va_end(ap);
1166 }
1167
1168 void NamedThread::initialize_named_thread() {
1169 set_native_thread_name(name());
1170 }
1171
1172 void NamedThread::print_on(outputStream* st) const {
1173 st->print("\"%s\" ", name());
1174 Thread::print_on(st);
1175 st->cr();
1176 }
1177
1178
1179 // ======= WatcherThread ========
1180
1181 // The watcher thread exists to simulate timer interrupts. It should
1182 // be replaced by an abstraction over whatever native support for
1183 // timer interrupts exists on the platform.
1184
1185 WatcherThread* WatcherThread::_watcher_thread = NULL;
1186 bool WatcherThread::_startable = false;
1187 volatile bool WatcherThread::_should_terminate = false;
1188
1189 WatcherThread::WatcherThread() : Thread(), _crash_protection(NULL) {
1190 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1191 if (os::create_thread(this, os::watcher_thread)) {
1192 _watcher_thread = this;
1193
1194 // Set the watcher thread to the highest OS priority which should not be
1195 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1196 // is created. The only normal thread using this priority is the reference
1197 // handler thread, which runs for very short intervals only.
1198 // If the VMThread's priority is not lower than the WatcherThread profiling
1199 // will be inaccurate.
1200 os::set_priority(this, MaxPriority);
1201 if (!DisableStartThread) {
1202 os::start_thread(this);
1203 }
1204 }
1205 }
1206
1207 int WatcherThread::sleep() const {
1208 // The WatcherThread does not participate in the safepoint protocol
1209 // for the PeriodicTask_lock because it is not a JavaThread.
1210 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1211
1212 if (_should_terminate) {
1213 // check for termination before we do any housekeeping or wait
1214 return 0; // we did not sleep.
1215 }
1216
1217 // remaining will be zero if there are no tasks,
1218 // causing the WatcherThread to sleep until a task is
1219 // enrolled
1220 int remaining = PeriodicTask::time_to_wait();
1221 int time_slept = 0;
1222
1223 // we expect this to timeout - we only ever get unparked when
1224 // we should terminate or when a new task has been enrolled
1225 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1226
1227 jlong time_before_loop = os::javaTimeNanos();
1228
1229 while (true) {
1230 bool timedout = PeriodicTask_lock->wait(Mutex::_no_safepoint_check_flag,
1231 remaining);
1232 jlong now = os::javaTimeNanos();
1233
1234 if (remaining == 0) {
1235 // if we didn't have any tasks we could have waited for a long time
1236 // consider the time_slept zero and reset time_before_loop
1237 time_slept = 0;
1238 time_before_loop = now;
1239 } else {
1240 // need to recalculate since we might have new tasks in _tasks
1241 time_slept = (int) ((now - time_before_loop) / 1000000);
1242 }
1243
1244 // Change to task list or spurious wakeup of some kind
1245 if (timedout || _should_terminate) {
1246 break;
1247 }
1248
1249 remaining = PeriodicTask::time_to_wait();
1250 if (remaining == 0) {
1251 // Last task was just disenrolled so loop around and wait until
1252 // another task gets enrolled
1253 continue;
1254 }
1255
1256 remaining -= time_slept;
1257 if (remaining <= 0) {
1258 break;
1259 }
1260 }
1261
1262 return time_slept;
1263 }
1264
1265 void WatcherThread::run() {
1266 assert(this == watcher_thread(), "just checking");
1267
1268 this->record_stack_base_and_size();
1269 this->set_native_thread_name(this->name());
1270 this->set_active_handles(JNIHandleBlock::allocate_block());
1271 while (true) {
1272 assert(watcher_thread() == Thread::current(), "thread consistency check");
1273 assert(watcher_thread() == this, "thread consistency check");
1274
1275 // Calculate how long it'll be until the next PeriodicTask work
1276 // should be done, and sleep that amount of time.
1277 int time_waited = sleep();
1278
1279 if (VMError::is_error_reported()) {
1280 // A fatal error has happened, the error handler(VMError::report_and_die)
1281 // should abort JVM after creating an error log file. However in some
1282 // rare cases, the error handler itself might deadlock. Here periodically
1283 // check for error reporting timeouts, and if it happens, just proceed to
1284 // abort the VM.
1285
1286 // This code is in WatcherThread because WatcherThread wakes up
1287 // periodically so the fatal error handler doesn't need to do anything;
1288 // also because the WatcherThread is less likely to crash than other
1289 // threads.
1290
1291 for (;;) {
1292 // Note: we use naked sleep in this loop because we want to avoid using
1293 // any kind of VM infrastructure which may be broken at this point.
1294 if (VMError::check_timeout()) {
1295 // We hit error reporting timeout. Error reporting was interrupted and
1296 // will be wrapping things up now (closing files etc). Give it some more
1297 // time, then quit the VM.
1298 os::naked_short_sleep(200);
1299 // Print a message to stderr.
1300 fdStream err(defaultStream::output_fd());
1301 err.print_raw_cr("# [ timer expired, abort... ]");
1302 // skip atexit/vm_exit/vm_abort hooks
1303 os::die();
1304 }
1305
1306 // Wait a second, then recheck for timeout.
1307 os::naked_short_sleep(999);
1308 }
1309 }
1310
1311 if (_should_terminate) {
1312 // check for termination before posting the next tick
1313 break;
1314 }
1315
1316 PeriodicTask::real_time_tick(time_waited);
1317 }
1318
1319 // Signal that it is terminated
1320 {
1321 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1322 _watcher_thread = NULL;
1323 Terminator_lock->notify();
1324 }
1325 }
1326
1327 void WatcherThread::start() {
1328 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1329
1330 if (watcher_thread() == NULL && _startable) {
1331 _should_terminate = false;
1332 // Create the single instance of WatcherThread
1333 new WatcherThread();
1334 }
1335 }
1336
1337 void WatcherThread::make_startable() {
1338 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1339 _startable = true;
1340 }
1341
1342 void WatcherThread::stop() {
1343 {
1344 // Follow normal safepoint aware lock enter protocol since the
1345 // WatcherThread is stopped by another JavaThread.
1346 MutexLocker ml(PeriodicTask_lock);
1347 _should_terminate = true;
1348
1349 WatcherThread* watcher = watcher_thread();
1350 if (watcher != NULL) {
1351 // unpark the WatcherThread so it can see that it should terminate
1352 watcher->unpark();
1353 }
1354 }
1355
1356 MutexLocker mu(Terminator_lock);
1357
1358 while (watcher_thread() != NULL) {
1359 // This wait should make safepoint checks, wait without a timeout,
1360 // and wait as a suspend-equivalent condition.
1361 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1362 Mutex::_as_suspend_equivalent_flag);
1363 }
1364 }
1365
1366 void WatcherThread::unpark() {
1367 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1368 PeriodicTask_lock->notify();
1369 }
1370
1371 void WatcherThread::print_on(outputStream* st) const {
1372 st->print("\"%s\" ", name());
1373 Thread::print_on(st);
1374 st->cr();
1375 }
1376
1377 // ======= JavaThread ========
1378
1379 #if INCLUDE_JVMCI
1380
1381 jlong* JavaThread::_jvmci_old_thread_counters;
1382
1383 bool jvmci_counters_include(JavaThread* thread) {
1384 oop threadObj = thread->threadObj();
1385 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
1386 }
1387
1388 void JavaThread::collect_counters(typeArrayOop array) {
1389 if (JVMCICounterSize > 0) {
1390 MutexLocker tl(Threads_lock);
1391 for (int i = 0; i < array->length(); i++) {
1392 array->long_at_put(i, _jvmci_old_thread_counters[i]);
1393 }
1394 for (JavaThread* tp = Threads::first(); tp != NULL; tp = tp->next()) {
1395 if (jvmci_counters_include(tp)) {
1396 for (int i = 0; i < array->length(); i++) {
1397 array->long_at_put(i, array->long_at(i) + tp->_jvmci_counters[i]);
1398 }
1399 }
1400 }
1401 }
1402 }
1403
1404 #endif // INCLUDE_JVMCI
1405
1406 // A JavaThread is a normal Java thread
1407
1408 void JavaThread::initialize() {
1409 // Initialize fields
1410
1411 set_saved_exception_pc(NULL);
1412 set_threadObj(NULL);
1413 _anchor.clear();
1414 set_entry_point(NULL);
1415 set_jni_functions(jni_functions());
1416 set_callee_target(NULL);
1417 set_vm_result(NULL);
1418 set_vm_result_2(NULL);
1419 set_vframe_array_head(NULL);
1420 set_vframe_array_last(NULL);
1421 set_deferred_locals(NULL);
1422 set_deopt_mark(NULL);
1423 set_deopt_compiled_method(NULL);
1424 clear_must_deopt_id();
1425 set_monitor_chunks(NULL);
1426 set_next(NULL);
1427 set_thread_state(_thread_new);
1428 _terminated = _not_terminated;
1429 _privileged_stack_top = NULL;
1430 _array_for_gc = NULL;
1431 _suspend_equivalent = false;
1432 _in_deopt_handler = 0;
1433 _doing_unsafe_access = false;
1434 _stack_guard_state = stack_guard_unused;
1435 #if INCLUDE_JVMCI
1436 _pending_monitorenter = false;
1437 _pending_deoptimization = -1;
1438 _pending_failed_speculation = NULL;
1439 _pending_transfer_to_interpreter = false;
1440 _adjusting_comp_level = false;
1441 _jvmci._alternate_call_target = NULL;
1442 assert(_jvmci._implicit_exception_pc == NULL, "must be");
1443 if (JVMCICounterSize > 0) {
1444 _jvmci_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtInternal);
1445 memset(_jvmci_counters, 0, sizeof(jlong) * JVMCICounterSize);
1446 } else {
1447 _jvmci_counters = NULL;
1448 }
1449 #endif // INCLUDE_JVMCI
1450 _reserved_stack_activation = NULL; // stack base not known yet
1451 (void)const_cast<oop&>(_exception_oop = oop(NULL));
1452 _exception_pc = 0;
1453 _exception_handler_pc = 0;
1454 _is_method_handle_return = 0;
1455 _jvmti_thread_state= NULL;
1456 _should_post_on_exceptions_flag = JNI_FALSE;
1457 _jvmti_get_loaded_classes_closure = NULL;
1458 _interp_only_mode = 0;
1459 _special_runtime_exit_condition = _no_async_condition;
1460 _pending_async_exception = NULL;
1461 _thread_stat = NULL;
1462 _thread_stat = new ThreadStatistics();
1463 _blocked_on_compilation = false;
1464 _jni_active_critical = 0;
1465 _pending_jni_exception_check_fn = NULL;
1466 _do_not_unlock_if_synchronized = false;
1467 _cached_monitor_info = NULL;
1468 _parker = Parker::Allocate(this);
1469
1470 #ifndef PRODUCT
1471 _jmp_ring_index = 0;
1472 for (int ji = 0; ji < jump_ring_buffer_size; ji++) {
1473 record_jump(NULL, NULL, NULL, 0);
1474 }
1475 #endif // PRODUCT
1476
1477 // Setup safepoint state info for this thread
1478 ThreadSafepointState::create(this);
1479
1480 debug_only(_java_call_counter = 0);
1481
1482 // JVMTI PopFrame support
1483 _popframe_condition = popframe_inactive;
1484 _popframe_preserved_args = NULL;
1485 _popframe_preserved_args_size = 0;
1486 _frames_to_pop_failed_realloc = 0;
1487
1488 pd_initialize();
1489 }
1490
1491 #if INCLUDE_ALL_GCS
1492 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1493 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1494 #endif // INCLUDE_ALL_GCS
1495
1496 JavaThread::JavaThread(bool is_attaching_via_jni) :
1497 Thread()
1498 #if INCLUDE_ALL_GCS
1499 , _satb_mark_queue(&_satb_mark_queue_set),
1500 _dirty_card_queue(&_dirty_card_queue_set)
1501 #endif // INCLUDE_ALL_GCS
1502 {
1503 initialize();
1504 if (is_attaching_via_jni) {
1505 _jni_attach_state = _attaching_via_jni;
1506 } else {
1507 _jni_attach_state = _not_attaching_via_jni;
1508 }
1509 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
1510 }
1511
1512 bool JavaThread::reguard_stack(address cur_sp) {
1513 if (_stack_guard_state != stack_guard_yellow_reserved_disabled
1514 && _stack_guard_state != stack_guard_reserved_disabled) {
1515 return true; // Stack already guarded or guard pages not needed.
1516 }
1517
1518 if (register_stack_overflow()) {
1519 // For those architectures which have separate register and
1520 // memory stacks, we must check the register stack to see if
1521 // it has overflowed.
1522 return false;
1523 }
1524
1525 // Java code never executes within the yellow zone: the latter is only
1526 // there to provoke an exception during stack banging. If java code
1527 // is executing there, either StackShadowPages should be larger, or
1528 // some exception code in c1, c2 or the interpreter isn't unwinding
1529 // when it should.
1530 guarantee(cur_sp > stack_reserved_zone_base(),
1531 "not enough space to reguard - increase StackShadowPages");
1532 if (_stack_guard_state == stack_guard_yellow_reserved_disabled) {
1533 enable_stack_yellow_reserved_zone();
1534 if (reserved_stack_activation() != stack_base()) {
1535 set_reserved_stack_activation(stack_base());
1536 }
1537 } else if (_stack_guard_state == stack_guard_reserved_disabled) {
1538 set_reserved_stack_activation(stack_base());
1539 enable_stack_reserved_zone();
1540 }
1541 return true;
1542 }
1543
1544 bool JavaThread::reguard_stack(void) {
1545 return reguard_stack(os::current_stack_pointer());
1546 }
1547
1548
1549 void JavaThread::block_if_vm_exited() {
1550 if (_terminated == _vm_exited) {
1551 // _vm_exited is set at safepoint, and Threads_lock is never released
1552 // we will block here forever
1553 Threads_lock->lock_without_safepoint_check();
1554 ShouldNotReachHere();
1555 }
1556 }
1557
1558
1559 // Remove this ifdef when C1 is ported to the compiler interface.
1560 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1561 static void sweeper_thread_entry(JavaThread* thread, TRAPS);
1562
1563 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1564 Thread()
1565 #if INCLUDE_ALL_GCS
1566 , _satb_mark_queue(&_satb_mark_queue_set),
1567 _dirty_card_queue(&_dirty_card_queue_set)
1568 #endif // INCLUDE_ALL_GCS
1569 {
1570 initialize();
1571 _jni_attach_state = _not_attaching_via_jni;
1572 set_entry_point(entry_point);
1573 // Create the native thread itself.
1574 // %note runtime_23
1575 os::ThreadType thr_type = os::java_thread;
1576 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1577 os::java_thread;
1578 os::create_thread(this, thr_type, stack_sz);
1579 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1580 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1581 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1582 // the exception consists of creating the exception object & initializing it, initialization
1583 // will leave the VM via a JavaCall and then all locks must be unlocked).
1584 //
1585 // The thread is still suspended when we reach here. Thread must be explicit started
1586 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1587 // by calling Threads:add. The reason why this is not done here, is because the thread
1588 // object must be fully initialized (take a look at JVM_Start)
1589 }
1590
1591 JavaThread::~JavaThread() {
1592
1593 // JSR166 -- return the parker to the free list
1594 Parker::Release(_parker);
1595 _parker = NULL;
1596
1597 // Free any remaining previous UnrollBlock
1598 vframeArray* old_array = vframe_array_last();
1599
1600 if (old_array != NULL) {
1601 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1602 old_array->set_unroll_block(NULL);
1603 delete old_info;
1604 delete old_array;
1605 }
1606
1607 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1608 if (deferred != NULL) {
1609 // This can only happen if thread is destroyed before deoptimization occurs.
1610 assert(deferred->length() != 0, "empty array!");
1611 do {
1612 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1613 deferred->remove_at(0);
1614 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1615 delete dlv;
1616 } while (deferred->length() != 0);
1617 delete deferred;
1618 }
1619
1620 // All Java related clean up happens in exit
1621 ThreadSafepointState::destroy(this);
1622 if (_thread_stat != NULL) delete _thread_stat;
1623
1624 #if INCLUDE_JVMCI
1625 if (JVMCICounterSize > 0) {
1626 if (jvmci_counters_include(this)) {
1627 for (int i = 0; i < JVMCICounterSize; i++) {
1628 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
1629 }
1630 }
1631 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
1632 }
1633 #endif // INCLUDE_JVMCI
1634 }
1635
1636
1637 // The first routine called by a new Java thread
1638 void JavaThread::run() {
1639 // initialize thread-local alloc buffer related fields
1640 this->initialize_tlab();
1641
1642 // used to test validity of stack trace backs
1643 this->record_base_of_stack_pointer();
1644
1645 // Record real stack base and size.
1646 this->record_stack_base_and_size();
1647
1648 this->create_stack_guard_pages();
1649
1650 this->cache_global_variables();
1651
1652 // Thread is now sufficient initialized to be handled by the safepoint code as being
1653 // in the VM. Change thread state from _thread_new to _thread_in_vm
1654 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1655
1656 assert(JavaThread::current() == this, "sanity check");
1657 assert(!Thread::current()->owns_locks(), "sanity check");
1658
1659 DTRACE_THREAD_PROBE(start, this);
1660
1661 // This operation might block. We call that after all safepoint checks for a new thread has
1662 // been completed.
1663 this->set_active_handles(JNIHandleBlock::allocate_block());
1664
1665 if (JvmtiExport::should_post_thread_life()) {
1666 JvmtiExport::post_thread_start(this);
1667 }
1668
1669 EventThreadStart event;
1670 if (event.should_commit()) {
1671 event.set_thread(THREAD_TRACE_ID(this));
1672 event.commit();
1673 }
1674
1675 // We call another function to do the rest so we are sure that the stack addresses used
1676 // from there will be lower than the stack base just computed
1677 thread_main_inner();
1678
1679 // Note, thread is no longer valid at this point!
1680 }
1681
1682
1683 void JavaThread::thread_main_inner() {
1684 assert(JavaThread::current() == this, "sanity check");
1685 assert(this->threadObj() != NULL, "just checking");
1686
1687 // Execute thread entry point unless this thread has a pending exception
1688 // or has been stopped before starting.
1689 // Note: Due to JVM_StopThread we can have pending exceptions already!
1690 if (!this->has_pending_exception() &&
1691 !java_lang_Thread::is_stillborn(this->threadObj())) {
1692 {
1693 ResourceMark rm(this);
1694 this->set_native_thread_name(this->get_thread_name());
1695 }
1696 HandleMark hm(this);
1697 this->entry_point()(this, this);
1698 }
1699
1700 DTRACE_THREAD_PROBE(stop, this);
1701
1702 this->exit(false);
1703 delete this;
1704 }
1705
1706
1707 static void ensure_join(JavaThread* thread) {
1708 // We do not need to grap the Threads_lock, since we are operating on ourself.
1709 Handle threadObj(thread, thread->threadObj());
1710 assert(threadObj.not_null(), "java thread object must exist");
1711 ObjectLocker lock(threadObj, thread);
1712 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1713 thread->clear_pending_exception();
1714 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1715 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1716 // Clear the native thread instance - this makes isAlive return false and allows the join()
1717 // to complete once we've done the notify_all below
1718 java_lang_Thread::set_thread(threadObj(), NULL);
1719 lock.notify_all(thread);
1720 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1721 thread->clear_pending_exception();
1722 }
1723
1724
1725 // For any new cleanup additions, please check to see if they need to be applied to
1726 // cleanup_failed_attach_current_thread as well.
1727 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1728 assert(this == JavaThread::current(), "thread consistency check");
1729
1730 HandleMark hm(this);
1731 Handle uncaught_exception(this, this->pending_exception());
1732 this->clear_pending_exception();
1733 Handle threadObj(this, this->threadObj());
1734 assert(threadObj.not_null(), "Java thread object should be created");
1735
1736 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1737 {
1738 EXCEPTION_MARK;
1739
1740 CLEAR_PENDING_EXCEPTION;
1741 }
1742 if (!destroy_vm) {
1743 if (uncaught_exception.not_null()) {
1744 EXCEPTION_MARK;
1745 // Call method Thread.dispatchUncaughtException().
1746 Klass* thread_klass = SystemDictionary::Thread_klass();
1747 JavaValue result(T_VOID);
1748 JavaCalls::call_virtual(&result,
1749 threadObj, thread_klass,
1750 vmSymbols::dispatchUncaughtException_name(),
1751 vmSymbols::throwable_void_signature(),
1752 uncaught_exception,
1753 THREAD);
1754 if (HAS_PENDING_EXCEPTION) {
1755 ResourceMark rm(this);
1756 jio_fprintf(defaultStream::error_stream(),
1757 "\nException: %s thrown from the UncaughtExceptionHandler"
1758 " in thread \"%s\"\n",
1759 pending_exception()->klass()->external_name(),
1760 get_thread_name());
1761 CLEAR_PENDING_EXCEPTION;
1762 }
1763 }
1764
1765 // Called before the java thread exit since we want to read info
1766 // from java_lang_Thread object
1767 EventThreadEnd event;
1768 if (event.should_commit()) {
1769 event.set_thread(THREAD_TRACE_ID(this));
1770 event.commit();
1771 }
1772
1773 // Call after last event on thread
1774 EVENT_THREAD_EXIT(this);
1775
1776 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1777 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1778 // is deprecated anyhow.
1779 if (!is_Compiler_thread()) {
1780 int count = 3;
1781 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1782 EXCEPTION_MARK;
1783 JavaValue result(T_VOID);
1784 Klass* thread_klass = SystemDictionary::Thread_klass();
1785 JavaCalls::call_virtual(&result,
1786 threadObj, thread_klass,
1787 vmSymbols::exit_method_name(),
1788 vmSymbols::void_method_signature(),
1789 THREAD);
1790 CLEAR_PENDING_EXCEPTION;
1791 }
1792 }
1793 // notify JVMTI
1794 if (JvmtiExport::should_post_thread_life()) {
1795 JvmtiExport::post_thread_end(this);
1796 }
1797
1798 // We have notified the agents that we are exiting, before we go on,
1799 // we must check for a pending external suspend request and honor it
1800 // in order to not surprise the thread that made the suspend request.
1801 while (true) {
1802 {
1803 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1804 if (!is_external_suspend()) {
1805 set_terminated(_thread_exiting);
1806 ThreadService::current_thread_exiting(this);
1807 break;
1808 }
1809 // Implied else:
1810 // Things get a little tricky here. We have a pending external
1811 // suspend request, but we are holding the SR_lock so we
1812 // can't just self-suspend. So we temporarily drop the lock
1813 // and then self-suspend.
1814 }
1815
1816 ThreadBlockInVM tbivm(this);
1817 java_suspend_self();
1818
1819 // We're done with this suspend request, but we have to loop around
1820 // and check again. Eventually we will get SR_lock without a pending
1821 // external suspend request and will be able to mark ourselves as
1822 // exiting.
1823 }
1824 // no more external suspends are allowed at this point
1825 } else {
1826 // before_exit() has already posted JVMTI THREAD_END events
1827 }
1828
1829 // Notify waiters on thread object. This has to be done after exit() is called
1830 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1831 // group should have the destroyed bit set before waiters are notified).
1832 ensure_join(this);
1833 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1834
1835 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1836 // held by this thread must be released. The spec does not distinguish
1837 // between JNI-acquired and regular Java monitors. We can only see
1838 // regular Java monitors here if monitor enter-exit matching is broken.
1839 //
1840 // Optionally release any monitors for regular JavaThread exits. This
1841 // is provided as a work around for any bugs in monitor enter-exit
1842 // matching. This can be expensive so it is not enabled by default.
1843 //
1844 // ensure_join() ignores IllegalThreadStateExceptions, and so does
1845 // ObjectSynchronizer::release_monitors_owned_by_thread().
1846 if (exit_type == jni_detach || ObjectMonitor::Knob_ExitRelease) {
1847 // Sanity check even though JNI DetachCurrentThread() would have
1848 // returned JNI_ERR if there was a Java frame. JavaThread exit
1849 // should be done executing Java code by the time we get here.
1850 assert(!this->has_last_Java_frame(),
1851 "should not have a Java frame when detaching or exiting");
1852 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1853 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1854 }
1855
1856 // These things needs to be done while we are still a Java Thread. Make sure that thread
1857 // is in a consistent state, in case GC happens
1858 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1859
1860 if (active_handles() != NULL) {
1861 JNIHandleBlock* block = active_handles();
1862 set_active_handles(NULL);
1863 JNIHandleBlock::release_block(block);
1864 }
1865
1866 if (free_handle_block() != NULL) {
1867 JNIHandleBlock* block = free_handle_block();
1868 set_free_handle_block(NULL);
1869 JNIHandleBlock::release_block(block);
1870 }
1871
1872 // These have to be removed while this is still a valid thread.
1873 remove_stack_guard_pages();
1874
1875 if (UseTLAB) {
1876 tlab().make_parsable(true); // retire TLAB
1877 }
1878
1879 if (JvmtiEnv::environments_might_exist()) {
1880 JvmtiExport::cleanup_thread(this);
1881 }
1882
1883 // We must flush any deferred card marks before removing a thread from
1884 // the list of active threads.
1885 Universe::heap()->flush_deferred_store_barrier(this);
1886 assert(deferred_card_mark().is_empty(), "Should have been flushed");
1887
1888 #if INCLUDE_ALL_GCS
1889 // We must flush the G1-related buffers before removing a thread
1890 // from the list of active threads. We must do this after any deferred
1891 // card marks have been flushed (above) so that any entries that are
1892 // added to the thread's dirty card queue as a result are not lost.
1893 if (UseG1GC) {
1894 flush_barrier_queues();
1895 }
1896 #endif // INCLUDE_ALL_GCS
1897
1898 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
1899 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
1900 os::current_thread_id());
1901
1902 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1903 Threads::remove(this);
1904 }
1905
1906 #if INCLUDE_ALL_GCS
1907 // Flush G1-related queues.
1908 void JavaThread::flush_barrier_queues() {
1909 satb_mark_queue().flush();
1910 dirty_card_queue().flush();
1911 }
1912
1913 void JavaThread::initialize_queues() {
1914 assert(!SafepointSynchronize::is_at_safepoint(),
1915 "we should not be at a safepoint");
1916
1917 SATBMarkQueue& satb_queue = satb_mark_queue();
1918 SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
1919 // The SATB queue should have been constructed with its active
1920 // field set to false.
1921 assert(!satb_queue.is_active(), "SATB queue should not be active");
1922 assert(satb_queue.is_empty(), "SATB queue should be empty");
1923 // If we are creating the thread during a marking cycle, we should
1924 // set the active field of the SATB queue to true.
1925 if (satb_queue_set.is_active()) {
1926 satb_queue.set_active(true);
1927 }
1928
1929 DirtyCardQueue& dirty_queue = dirty_card_queue();
1930 // The dirty card queue should have been constructed with its
1931 // active field set to true.
1932 assert(dirty_queue.is_active(), "dirty card queue should be active");
1933 }
1934 #endif // INCLUDE_ALL_GCS
1935
1936 void JavaThread::cleanup_failed_attach_current_thread() {
1937 if (active_handles() != NULL) {
1938 JNIHandleBlock* block = active_handles();
1939 set_active_handles(NULL);
1940 JNIHandleBlock::release_block(block);
1941 }
1942
1943 if (free_handle_block() != NULL) {
1944 JNIHandleBlock* block = free_handle_block();
1945 set_free_handle_block(NULL);
1946 JNIHandleBlock::release_block(block);
1947 }
1948
1949 // These have to be removed while this is still a valid thread.
1950 remove_stack_guard_pages();
1951
1952 if (UseTLAB) {
1953 tlab().make_parsable(true); // retire TLAB, if any
1954 }
1955
1956 #if INCLUDE_ALL_GCS
1957 if (UseG1GC) {
1958 flush_barrier_queues();
1959 }
1960 #endif // INCLUDE_ALL_GCS
1961
1962 Threads::remove(this);
1963 delete this;
1964 }
1965
1966
1967
1968
1969 JavaThread* JavaThread::active() {
1970 Thread* thread = Thread::current();
1971 if (thread->is_Java_thread()) {
1972 return (JavaThread*) thread;
1973 } else {
1974 assert(thread->is_VM_thread(), "this must be a vm thread");
1975 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1976 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1977 assert(ret->is_Java_thread(), "must be a Java thread");
1978 return ret;
1979 }
1980 }
1981
1982 bool JavaThread::is_lock_owned(address adr) const {
1983 if (Thread::is_lock_owned(adr)) return true;
1984
1985 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1986 if (chunk->contains(adr)) return true;
1987 }
1988
1989 return false;
1990 }
1991
1992
1993 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1994 chunk->set_next(monitor_chunks());
1995 set_monitor_chunks(chunk);
1996 }
1997
1998 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1999 guarantee(monitor_chunks() != NULL, "must be non empty");
2000 if (monitor_chunks() == chunk) {
2001 set_monitor_chunks(chunk->next());
2002 } else {
2003 MonitorChunk* prev = monitor_chunks();
2004 while (prev->next() != chunk) prev = prev->next();
2005 prev->set_next(chunk->next());
2006 }
2007 }
2008
2009 // JVM support.
2010
2011 // Note: this function shouldn't block if it's called in
2012 // _thread_in_native_trans state (such as from
2013 // check_special_condition_for_native_trans()).
2014 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
2015
2016 if (has_last_Java_frame() && has_async_condition()) {
2017 // If we are at a polling page safepoint (not a poll return)
2018 // then we must defer async exception because live registers
2019 // will be clobbered by the exception path. Poll return is
2020 // ok because the call we a returning from already collides
2021 // with exception handling registers and so there is no issue.
2022 // (The exception handling path kills call result registers but
2023 // this is ok since the exception kills the result anyway).
2024
2025 if (is_at_poll_safepoint()) {
2026 // if the code we are returning to has deoptimized we must defer
2027 // the exception otherwise live registers get clobbered on the
2028 // exception path before deoptimization is able to retrieve them.
2029 //
2030 RegisterMap map(this, false);
2031 frame caller_fr = last_frame().sender(&map);
2032 assert(caller_fr.is_compiled_frame(), "what?");
2033 if (caller_fr.is_deoptimized_frame()) {
2034 log_info(exceptions)("deferred async exception at compiled safepoint");
2035 return;
2036 }
2037 }
2038 }
2039
2040 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
2041 if (condition == _no_async_condition) {
2042 // Conditions have changed since has_special_runtime_exit_condition()
2043 // was called:
2044 // - if we were here only because of an external suspend request,
2045 // then that was taken care of above (or cancelled) so we are done
2046 // - if we were here because of another async request, then it has
2047 // been cleared between the has_special_runtime_exit_condition()
2048 // and now so again we are done
2049 return;
2050 }
2051
2052 // Check for pending async. exception
2053 if (_pending_async_exception != NULL) {
2054 // Only overwrite an already pending exception, if it is not a threadDeath.
2055 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
2056
2057 // We cannot call Exceptions::_throw(...) here because we cannot block
2058 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
2059
2060 if (log_is_enabled(Info, exceptions)) {
2061 ResourceMark rm;
2062 outputStream* logstream = Log(exceptions)::info_stream();
2063 logstream->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
2064 if (has_last_Java_frame()) {
2065 frame f = last_frame();
2066 logstream->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
2067 }
2068 logstream->print_cr(" of type: %s", _pending_async_exception->klass()->external_name());
2069 }
2070 _pending_async_exception = NULL;
2071 clear_has_async_exception();
2072 }
2073 }
2074
2075 if (check_unsafe_error &&
2076 condition == _async_unsafe_access_error && !has_pending_exception()) {
2077 condition = _no_async_condition; // done
2078 switch (thread_state()) {
2079 case _thread_in_vm: {
2080 JavaThread* THREAD = this;
2081 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2082 }
2083 case _thread_in_native: {
2084 ThreadInVMfromNative tiv(this);
2085 JavaThread* THREAD = this;
2086 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2087 }
2088 case _thread_in_Java: {
2089 ThreadInVMfromJava tiv(this);
2090 JavaThread* THREAD = this;
2091 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
2092 }
2093 default:
2094 ShouldNotReachHere();
2095 }
2096 }
2097
2098 assert(condition == _no_async_condition || has_pending_exception() ||
2099 (!check_unsafe_error && condition == _async_unsafe_access_error),
2100 "must have handled the async condition, if no exception");
2101 }
2102
2103 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
2104 //
2105 // Check for pending external suspend. Internal suspend requests do
2106 // not use handle_special_runtime_exit_condition().
2107 // If JNIEnv proxies are allowed, don't self-suspend if the target
2108 // thread is not the current thread. In older versions of jdbx, jdbx
2109 // threads could call into the VM with another thread's JNIEnv so we
2110 // can be here operating on behalf of a suspended thread (4432884).
2111 bool do_self_suspend = is_external_suspend_with_lock();
2112 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
2113 //
2114 // Because thread is external suspended the safepoint code will count
2115 // thread as at a safepoint. This can be odd because we can be here
2116 // as _thread_in_Java which would normally transition to _thread_blocked
2117 // at a safepoint. We would like to mark the thread as _thread_blocked
2118 // before calling java_suspend_self like all other callers of it but
2119 // we must then observe proper safepoint protocol. (We can't leave
2120 // _thread_blocked with a safepoint in progress). However we can be
2121 // here as _thread_in_native_trans so we can't use a normal transition
2122 // constructor/destructor pair because they assert on that type of
2123 // transition. We could do something like:
2124 //
2125 // JavaThreadState state = thread_state();
2126 // set_thread_state(_thread_in_vm);
2127 // {
2128 // ThreadBlockInVM tbivm(this);
2129 // java_suspend_self()
2130 // }
2131 // set_thread_state(_thread_in_vm_trans);
2132 // if (safepoint) block;
2133 // set_thread_state(state);
2134 //
2135 // but that is pretty messy. Instead we just go with the way the
2136 // code has worked before and note that this is the only path to
2137 // java_suspend_self that doesn't put the thread in _thread_blocked
2138 // mode.
2139
2140 frame_anchor()->make_walkable(this);
2141 java_suspend_self();
2142
2143 // We might be here for reasons in addition to the self-suspend request
2144 // so check for other async requests.
2145 }
2146
2147 if (check_asyncs) {
2148 check_and_handle_async_exceptions();
2149 }
2150 }
2151
2152 void JavaThread::send_thread_stop(oop java_throwable) {
2153 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
2154 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
2155 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
2156
2157 // Do not throw asynchronous exceptions against the compiler thread
2158 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
2159 if (!can_call_java()) return;
2160
2161 {
2162 // Actually throw the Throwable against the target Thread - however
2163 // only if there is no thread death exception installed already.
2164 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
2165 // If the topmost frame is a runtime stub, then we are calling into
2166 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
2167 // must deoptimize the caller before continuing, as the compiled exception handler table
2168 // may not be valid
2169 if (has_last_Java_frame()) {
2170 frame f = last_frame();
2171 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
2172 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2173 RegisterMap reg_map(this, UseBiasedLocking);
2174 frame compiled_frame = f.sender(®_map);
2175 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
2176 Deoptimization::deoptimize(this, compiled_frame, ®_map);
2177 }
2178 }
2179 }
2180
2181 // Set async. pending exception in thread.
2182 set_pending_async_exception(java_throwable);
2183
2184 if (log_is_enabled(Info, exceptions)) {
2185 ResourceMark rm;
2186 log_info(exceptions)("Pending Async. exception installed of type: %s",
2187 InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2188 }
2189 // for AbortVMOnException flag
2190 Exceptions::debug_check_abort(_pending_async_exception->klass()->external_name());
2191 }
2192 }
2193
2194
2195 // Interrupt thread so it will wake up from a potential wait()
2196 Thread::interrupt(this);
2197 }
2198
2199 // External suspension mechanism.
2200 //
2201 // Tell the VM to suspend a thread when ever it knows that it does not hold on
2202 // to any VM_locks and it is at a transition
2203 // Self-suspension will happen on the transition out of the vm.
2204 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
2205 //
2206 // Guarantees on return:
2207 // + Target thread will not execute any new bytecode (that's why we need to
2208 // force a safepoint)
2209 // + Target thread will not enter any new monitors
2210 //
2211 void JavaThread::java_suspend() {
2212 { MutexLocker mu(Threads_lock);
2213 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
2214 return;
2215 }
2216 }
2217
2218 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2219 if (!is_external_suspend()) {
2220 // a racing resume has cancelled us; bail out now
2221 return;
2222 }
2223
2224 // suspend is done
2225 uint32_t debug_bits = 0;
2226 // Warning: is_ext_suspend_completed() may temporarily drop the
2227 // SR_lock to allow the thread to reach a stable thread state if
2228 // it is currently in a transient thread state.
2229 if (is_ext_suspend_completed(false /* !called_by_wait */,
2230 SuspendRetryDelay, &debug_bits)) {
2231 return;
2232 }
2233 }
2234
2235 VM_ThreadSuspend vm_suspend;
2236 VMThread::execute(&vm_suspend);
2237 }
2238
2239 // Part II of external suspension.
2240 // A JavaThread self suspends when it detects a pending external suspend
2241 // request. This is usually on transitions. It is also done in places
2242 // where continuing to the next transition would surprise the caller,
2243 // e.g., monitor entry.
2244 //
2245 // Returns the number of times that the thread self-suspended.
2246 //
2247 // Note: DO NOT call java_suspend_self() when you just want to block current
2248 // thread. java_suspend_self() is the second stage of cooperative
2249 // suspension for external suspend requests and should only be used
2250 // to complete an external suspend request.
2251 //
2252 int JavaThread::java_suspend_self() {
2253 int ret = 0;
2254
2255 // we are in the process of exiting so don't suspend
2256 if (is_exiting()) {
2257 clear_external_suspend();
2258 return ret;
2259 }
2260
2261 assert(_anchor.walkable() ||
2262 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
2263 "must have walkable stack");
2264
2265 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2266
2267 assert(!this->is_ext_suspended(),
2268 "a thread trying to self-suspend should not already be suspended");
2269
2270 if (this->is_suspend_equivalent()) {
2271 // If we are self-suspending as a result of the lifting of a
2272 // suspend equivalent condition, then the suspend_equivalent
2273 // flag is not cleared until we set the ext_suspended flag so
2274 // that wait_for_ext_suspend_completion() returns consistent
2275 // results.
2276 this->clear_suspend_equivalent();
2277 }
2278
2279 // A racing resume may have cancelled us before we grabbed SR_lock
2280 // above. Or another external suspend request could be waiting for us
2281 // by the time we return from SR_lock()->wait(). The thread
2282 // that requested the suspension may already be trying to walk our
2283 // stack and if we return now, we can change the stack out from under
2284 // it. This would be a "bad thing (TM)" and cause the stack walker
2285 // to crash. We stay self-suspended until there are no more pending
2286 // external suspend requests.
2287 while (is_external_suspend()) {
2288 ret++;
2289 this->set_ext_suspended();
2290
2291 // _ext_suspended flag is cleared by java_resume()
2292 while (is_ext_suspended()) {
2293 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2294 }
2295 }
2296
2297 return ret;
2298 }
2299
2300 #ifdef ASSERT
2301 // verify the JavaThread has not yet been published in the Threads::list, and
2302 // hence doesn't need protection from concurrent access at this stage
2303 void JavaThread::verify_not_published() {
2304 if (!Threads_lock->owned_by_self()) {
2305 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2306 assert(!Threads::includes(this),
2307 "java thread shouldn't have been published yet!");
2308 } else {
2309 assert(!Threads::includes(this),
2310 "java thread shouldn't have been published yet!");
2311 }
2312 }
2313 #endif
2314
2315 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2316 // progress or when _suspend_flags is non-zero.
2317 // Current thread needs to self-suspend if there is a suspend request and/or
2318 // block if a safepoint is in progress.
2319 // Async exception ISN'T checked.
2320 // Note only the ThreadInVMfromNative transition can call this function
2321 // directly and when thread state is _thread_in_native_trans
2322 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2323 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2324
2325 JavaThread *curJT = JavaThread::current();
2326 bool do_self_suspend = thread->is_external_suspend();
2327
2328 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2329
2330 // If JNIEnv proxies are allowed, don't self-suspend if the target
2331 // thread is not the current thread. In older versions of jdbx, jdbx
2332 // threads could call into the VM with another thread's JNIEnv so we
2333 // can be here operating on behalf of a suspended thread (4432884).
2334 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2335 JavaThreadState state = thread->thread_state();
2336
2337 // We mark this thread_blocked state as a suspend-equivalent so
2338 // that a caller to is_ext_suspend_completed() won't be confused.
2339 // The suspend-equivalent state is cleared by java_suspend_self().
2340 thread->set_suspend_equivalent();
2341
2342 // If the safepoint code sees the _thread_in_native_trans state, it will
2343 // wait until the thread changes to other thread state. There is no
2344 // guarantee on how soon we can obtain the SR_lock and complete the
2345 // self-suspend request. It would be a bad idea to let safepoint wait for
2346 // too long. Temporarily change the state to _thread_blocked to
2347 // let the VM thread know that this thread is ready for GC. The problem
2348 // of changing thread state is that safepoint could happen just after
2349 // java_suspend_self() returns after being resumed, and VM thread will
2350 // see the _thread_blocked state. We must check for safepoint
2351 // after restoring the state and make sure we won't leave while a safepoint
2352 // is in progress.
2353 thread->set_thread_state(_thread_blocked);
2354 thread->java_suspend_self();
2355 thread->set_thread_state(state);
2356
2357 InterfaceSupport::serialize_thread_state_with_handler(thread);
2358 }
2359
2360 if (SafepointSynchronize::do_call_back()) {
2361 // If we are safepointing, then block the caller which may not be
2362 // the same as the target thread (see above).
2363 SafepointSynchronize::block(curJT);
2364 }
2365
2366 if (thread->is_deopt_suspend()) {
2367 thread->clear_deopt_suspend();
2368 RegisterMap map(thread, false);
2369 frame f = thread->last_frame();
2370 while (f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2371 f = f.sender(&map);
2372 }
2373 if (f.id() == thread->must_deopt_id()) {
2374 thread->clear_must_deopt_id();
2375 f.deoptimize(thread);
2376 } else {
2377 fatal("missed deoptimization!");
2378 }
2379 }
2380 }
2381
2382 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2383 // progress or when _suspend_flags is non-zero.
2384 // Current thread needs to self-suspend if there is a suspend request and/or
2385 // block if a safepoint is in progress.
2386 // Also check for pending async exception (not including unsafe access error).
2387 // Note only the native==>VM/Java barriers can call this function and when
2388 // thread state is _thread_in_native_trans.
2389 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2390 check_safepoint_and_suspend_for_native_trans(thread);
2391
2392 if (thread->has_async_exception()) {
2393 // We are in _thread_in_native_trans state, don't handle unsafe
2394 // access error since that may block.
2395 thread->check_and_handle_async_exceptions(false);
2396 }
2397 }
2398
2399 // This is a variant of the normal
2400 // check_special_condition_for_native_trans with slightly different
2401 // semantics for use by critical native wrappers. It does all the
2402 // normal checks but also performs the transition back into
2403 // thread_in_Java state. This is required so that critical natives
2404 // can potentially block and perform a GC if they are the last thread
2405 // exiting the GCLocker.
2406 void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) {
2407 check_special_condition_for_native_trans(thread);
2408
2409 // Finish the transition
2410 thread->set_thread_state(_thread_in_Java);
2411
2412 if (thread->do_critical_native_unlock()) {
2413 ThreadInVMfromJavaNoAsyncException tiv(thread);
2414 GCLocker::unlock_critical(thread);
2415 thread->clear_critical_native_unlock();
2416 }
2417 }
2418
2419 // We need to guarantee the Threads_lock here, since resumes are not
2420 // allowed during safepoint synchronization
2421 // Can only resume from an external suspension
2422 void JavaThread::java_resume() {
2423 assert_locked_or_safepoint(Threads_lock);
2424
2425 // Sanity check: thread is gone, has started exiting or the thread
2426 // was not externally suspended.
2427 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2428 return;
2429 }
2430
2431 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2432
2433 clear_external_suspend();
2434
2435 if (is_ext_suspended()) {
2436 clear_ext_suspended();
2437 SR_lock()->notify_all();
2438 }
2439 }
2440
2441 size_t JavaThread::_stack_red_zone_size = 0;
2442 size_t JavaThread::_stack_yellow_zone_size = 0;
2443 size_t JavaThread::_stack_reserved_zone_size = 0;
2444 size_t JavaThread::_stack_shadow_zone_size = 0;
2445
2446 void JavaThread::create_stack_guard_pages() {
2447 if (!os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) { return; }
2448 address low_addr = stack_end();
2449 size_t len = stack_guard_zone_size();
2450
2451 int must_commit = os::must_commit_stack_guard_pages();
2452 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2453
2454 if (must_commit && !os::create_stack_guard_pages((char *) low_addr, len)) {
2455 log_warning(os, thread)("Attempt to allocate stack guard pages failed.");
2456 return;
2457 }
2458
2459 if (os::guard_memory((char *) low_addr, len)) {
2460 _stack_guard_state = stack_guard_enabled;
2461 } else {
2462 log_warning(os, thread)("Attempt to protect stack guard pages failed ("
2463 PTR_FORMAT "-" PTR_FORMAT ").", p2i(low_addr), p2i(low_addr + len));
2464 if (os::uncommit_memory((char *) low_addr, len)) {
2465 log_warning(os, thread)("Attempt to deallocate stack guard pages failed.");
2466 }
2467 return;
2468 }
2469
2470 log_debug(os, thread)("Thread " UINTX_FORMAT " stack guard pages activated: "
2471 PTR_FORMAT "-" PTR_FORMAT ".",
2472 os::current_thread_id(), p2i(low_addr), p2i(low_addr + len));
2473 }
2474
2475 void JavaThread::remove_stack_guard_pages() {
2476 assert(Thread::current() == this, "from different thread");
2477 if (_stack_guard_state == stack_guard_unused) return;
2478 address low_addr = stack_end();
2479 size_t len = stack_guard_zone_size();
2480
2481 if (os::must_commit_stack_guard_pages()) {
2482 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2483 _stack_guard_state = stack_guard_unused;
2484 } else {
2485 log_warning(os, thread)("Attempt to deallocate stack guard pages failed ("
2486 PTR_FORMAT "-" PTR_FORMAT ").", p2i(low_addr), p2i(low_addr + len));
2487 return;
2488 }
2489 } else {
2490 if (_stack_guard_state == stack_guard_unused) return;
2491 if (os::unguard_memory((char *) low_addr, len)) {
2492 _stack_guard_state = stack_guard_unused;
2493 } else {
2494 log_warning(os, thread)("Attempt to unprotect stack guard pages failed ("
2495 PTR_FORMAT "-" PTR_FORMAT ").", p2i(low_addr), p2i(low_addr + len));
2496 return;
2497 }
2498 }
2499
2500 log_debug(os, thread)("Thread " UINTX_FORMAT " stack guard pages removed: "
2501 PTR_FORMAT "-" PTR_FORMAT ".",
2502 os::current_thread_id(), p2i(low_addr), p2i(low_addr + len));
2503 }
2504
2505 void JavaThread::enable_stack_reserved_zone() {
2506 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2507 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2508
2509 // The base notation is from the stack's point of view, growing downward.
2510 // We need to adjust it to work correctly with guard_memory()
2511 address base = stack_reserved_zone_base() - stack_reserved_zone_size();
2512
2513 guarantee(base < stack_base(),"Error calculating stack reserved zone");
2514 guarantee(base < os::current_stack_pointer(),"Error calculating stack reserved zone");
2515
2516 if (os::guard_memory((char *) base, stack_reserved_zone_size())) {
2517 _stack_guard_state = stack_guard_enabled;
2518 } else {
2519 warning("Attempt to guard stack reserved zone failed.");
2520 }
2521 enable_register_stack_guard();
2522 }
2523
2524 void JavaThread::disable_stack_reserved_zone() {
2525 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2526 assert(_stack_guard_state != stack_guard_reserved_disabled, "already disabled");
2527
2528 // Simply return if called for a thread that does not use guard pages.
2529 if (_stack_guard_state == stack_guard_unused) return;
2530
2531 // The base notation is from the stack's point of view, growing downward.
2532 // We need to adjust it to work correctly with guard_memory()
2533 address base = stack_reserved_zone_base() - stack_reserved_zone_size();
2534
2535 if (os::unguard_memory((char *)base, stack_reserved_zone_size())) {
2536 _stack_guard_state = stack_guard_reserved_disabled;
2537 } else {
2538 warning("Attempt to unguard stack reserved zone failed.");
2539 }
2540 disable_register_stack_guard();
2541 }
2542
2543 void JavaThread::enable_stack_yellow_reserved_zone() {
2544 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2545 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2546
2547 // The base notation is from the stacks point of view, growing downward.
2548 // We need to adjust it to work correctly with guard_memory()
2549 address base = stack_red_zone_base();
2550
2551 guarantee(base < stack_base(), "Error calculating stack yellow zone");
2552 guarantee(base < os::current_stack_pointer(), "Error calculating stack yellow zone");
2553
2554 if (os::guard_memory((char *) base, stack_yellow_reserved_zone_size())) {
2555 _stack_guard_state = stack_guard_enabled;
2556 } else {
2557 warning("Attempt to guard stack yellow zone failed.");
2558 }
2559 enable_register_stack_guard();
2560 }
2561
2562 void JavaThread::disable_stack_yellow_reserved_zone() {
2563 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2564 assert(_stack_guard_state != stack_guard_yellow_reserved_disabled, "already disabled");
2565
2566 // Simply return if called for a thread that does not use guard pages.
2567 if (_stack_guard_state == stack_guard_unused) return;
2568
2569 // The base notation is from the stacks point of view, growing downward.
2570 // We need to adjust it to work correctly with guard_memory()
2571 address base = stack_red_zone_base();
2572
2573 if (os::unguard_memory((char *)base, stack_yellow_reserved_zone_size())) {
2574 _stack_guard_state = stack_guard_yellow_reserved_disabled;
2575 } else {
2576 warning("Attempt to unguard stack yellow zone failed.");
2577 }
2578 disable_register_stack_guard();
2579 }
2580
2581 void JavaThread::enable_stack_red_zone() {
2582 // The base notation is from the stacks point of view, growing downward.
2583 // We need to adjust it to work correctly with guard_memory()
2584 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2585 address base = stack_red_zone_base() - stack_red_zone_size();
2586
2587 guarantee(base < stack_base(), "Error calculating stack red zone");
2588 guarantee(base < os::current_stack_pointer(), "Error calculating stack red zone");
2589
2590 if (!os::guard_memory((char *) base, stack_red_zone_size())) {
2591 warning("Attempt to guard stack red zone failed.");
2592 }
2593 }
2594
2595 void JavaThread::disable_stack_red_zone() {
2596 // The base notation is from the stacks point of view, growing downward.
2597 // We need to adjust it to work correctly with guard_memory()
2598 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2599 address base = stack_red_zone_base() - stack_red_zone_size();
2600 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2601 warning("Attempt to unguard stack red zone failed.");
2602 }
2603 }
2604
2605 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2606 // ignore is there is no stack
2607 if (!has_last_Java_frame()) return;
2608 // traverse the stack frames. Starts from top frame.
2609 for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2610 frame* fr = fst.current();
2611 f(fr, fst.register_map());
2612 }
2613 }
2614
2615
2616 #ifndef PRODUCT
2617 // Deoptimization
2618 // Function for testing deoptimization
2619 void JavaThread::deoptimize() {
2620 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2621 StackFrameStream fst(this, UseBiasedLocking);
2622 bool deopt = false; // Dump stack only if a deopt actually happens.
2623 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2624 // Iterate over all frames in the thread and deoptimize
2625 for (; !fst.is_done(); fst.next()) {
2626 if (fst.current()->can_be_deoptimized()) {
2627
2628 if (only_at) {
2629 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2630 // consists of comma or carriage return separated numbers so
2631 // search for the current bci in that string.
2632 address pc = fst.current()->pc();
2633 nmethod* nm = (nmethod*) fst.current()->cb();
2634 ScopeDesc* sd = nm->scope_desc_at(pc);
2635 char buffer[8];
2636 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2637 size_t len = strlen(buffer);
2638 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2639 while (found != NULL) {
2640 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2641 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2642 // Check that the bci found is bracketed by terminators.
2643 break;
2644 }
2645 found = strstr(found + 1, buffer);
2646 }
2647 if (!found) {
2648 continue;
2649 }
2650 }
2651
2652 if (DebugDeoptimization && !deopt) {
2653 deopt = true; // One-time only print before deopt
2654 tty->print_cr("[BEFORE Deoptimization]");
2655 trace_frames();
2656 trace_stack();
2657 }
2658 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2659 }
2660 }
2661
2662 if (DebugDeoptimization && deopt) {
2663 tty->print_cr("[AFTER Deoptimization]");
2664 trace_frames();
2665 }
2666 }
2667
2668
2669 // Make zombies
2670 void JavaThread::make_zombies() {
2671 for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2672 if (fst.current()->can_be_deoptimized()) {
2673 // it is a Java nmethod
2674 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2675 nm->make_not_entrant();
2676 }
2677 }
2678 }
2679 #endif // PRODUCT
2680
2681
2682 void JavaThread::deoptimized_wrt_marked_nmethods() {
2683 if (!has_last_Java_frame()) return;
2684 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2685 StackFrameStream fst(this, UseBiasedLocking);
2686 for (; !fst.is_done(); fst.next()) {
2687 if (fst.current()->should_be_deoptimized()) {
2688 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2689 }
2690 }
2691 }
2692
2693
2694 // If the caller is a NamedThread, then remember, in the current scope,
2695 // the given JavaThread in its _processed_thread field.
2696 class RememberProcessedThread: public StackObj {
2697 NamedThread* _cur_thr;
2698 public:
2699 RememberProcessedThread(JavaThread* jthr) {
2700 Thread* thread = Thread::current();
2701 if (thread->is_Named_thread()) {
2702 _cur_thr = (NamedThread *)thread;
2703 _cur_thr->set_processed_thread(jthr);
2704 } else {
2705 _cur_thr = NULL;
2706 }
2707 }
2708
2709 ~RememberProcessedThread() {
2710 if (_cur_thr) {
2711 _cur_thr->set_processed_thread(NULL);
2712 }
2713 }
2714 };
2715
2716 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
2717 // Verify that the deferred card marks have been flushed.
2718 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2719
2720 // Traverse the GCHandles
2721 Thread::oops_do(f, cf);
2722
2723 JVMCI_ONLY(f->do_oop((oop*)&_pending_failed_speculation);)
2724
2725 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
2726 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2727
2728 if (has_last_Java_frame()) {
2729 // Record JavaThread to GC thread
2730 RememberProcessedThread rpt(this);
2731
2732 // Traverse the privileged stack
2733 if (_privileged_stack_top != NULL) {
2734 _privileged_stack_top->oops_do(f);
2735 }
2736
2737 // traverse the registered growable array
2738 if (_array_for_gc != NULL) {
2739 for (int index = 0; index < _array_for_gc->length(); index++) {
2740 f->do_oop(_array_for_gc->adr_at(index));
2741 }
2742 }
2743
2744 // Traverse the monitor chunks
2745 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2746 chunk->oops_do(f);
2747 }
2748
2749 // Traverse the execution stack
2750 for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2751 fst.current()->oops_do(f, cf, fst.register_map());
2752 }
2753 }
2754
2755 // callee_target is never live across a gc point so NULL it here should
2756 // it still contain a methdOop.
2757
2758 set_callee_target(NULL);
2759
2760 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2761 // If we have deferred set_locals there might be oops waiting to be
2762 // written
2763 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2764 if (list != NULL) {
2765 for (int i = 0; i < list->length(); i++) {
2766 list->at(i)->oops_do(f);
2767 }
2768 }
2769
2770 // Traverse instance variables at the end since the GC may be moving things
2771 // around using this function
2772 f->do_oop((oop*) &_threadObj);
2773 f->do_oop((oop*) &_vm_result);
2774 f->do_oop((oop*) &_exception_oop);
2775 f->do_oop((oop*) &_pending_async_exception);
2776
2777 if (jvmti_thread_state() != NULL) {
2778 jvmti_thread_state()->oops_do(f);
2779 }
2780 }
2781
2782 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2783 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
2784 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2785
2786 if (has_last_Java_frame()) {
2787 // Traverse the execution stack
2788 for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2789 fst.current()->nmethods_do(cf);
2790 }
2791 }
2792 }
2793
2794 void JavaThread::metadata_do(void f(Metadata*)) {
2795 if (has_last_Java_frame()) {
2796 // Traverse the execution stack to call f() on the methods in the stack
2797 for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2798 fst.current()->metadata_do(f);
2799 }
2800 } else if (is_Compiler_thread()) {
2801 // need to walk ciMetadata in current compile tasks to keep alive.
2802 CompilerThread* ct = (CompilerThread*)this;
2803 if (ct->env() != NULL) {
2804 ct->env()->metadata_do(f);
2805 }
2806 if (ct->task() != NULL) {
2807 ct->task()->metadata_do(f);
2808 }
2809 }
2810 }
2811
2812 // Printing
2813 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2814 switch (_thread_state) {
2815 case _thread_uninitialized: return "_thread_uninitialized";
2816 case _thread_new: return "_thread_new";
2817 case _thread_new_trans: return "_thread_new_trans";
2818 case _thread_in_native: return "_thread_in_native";
2819 case _thread_in_native_trans: return "_thread_in_native_trans";
2820 case _thread_in_vm: return "_thread_in_vm";
2821 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2822 case _thread_in_Java: return "_thread_in_Java";
2823 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2824 case _thread_blocked: return "_thread_blocked";
2825 case _thread_blocked_trans: return "_thread_blocked_trans";
2826 default: return "unknown thread state";
2827 }
2828 }
2829
2830 #ifndef PRODUCT
2831 void JavaThread::print_thread_state_on(outputStream *st) const {
2832 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2833 };
2834 void JavaThread::print_thread_state() const {
2835 print_thread_state_on(tty);
2836 }
2837 #endif // PRODUCT
2838
2839 // Called by Threads::print() for VM_PrintThreads operation
2840 void JavaThread::print_on(outputStream *st) const {
2841 st->print_raw("\"");
2842 st->print_raw(get_thread_name());
2843 st->print_raw("\" ");
2844 oop thread_oop = threadObj();
2845 if (thread_oop != NULL) {
2846 st->print("#" INT64_FORMAT " ", (int64_t)java_lang_Thread::thread_id(thread_oop));
2847 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2848 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2849 }
2850 Thread::print_on(st);
2851 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2852 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2853 if (thread_oop != NULL) {
2854 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2855 }
2856 #ifndef PRODUCT
2857 print_thread_state_on(st);
2858 _safepoint_state->print_on(st);
2859 #endif // PRODUCT
2860 if (is_Compiler_thread()) {
2861 CompilerThread* ct = (CompilerThread*)this;
2862 if (ct->task() != NULL) {
2863 st->print(" Compiling: ");
2864 ct->task()->print(st, NULL, true, false);
2865 } else {
2866 st->print(" No compile task");
2867 }
2868 st->cr();
2869 }
2870 }
2871
2872 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
2873 st->print("%s", get_thread_name_string(buf, buflen));
2874 }
2875
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 p2i(stack_end()), p2i(stack_base()));
2891 st->print("]");
2892 return;
2893 }
2894
2895 // Verification
2896
2897 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2898
2899 void JavaThread::verify() {
2900 // Verify oops in the thread.
2901 oops_do(&VerifyOopClosure::verify_oop, NULL);
2902
2903 // Verify the stack frames.
2904 frames_do(frame_verify);
2905 }
2906
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 }
2928
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 } else {
2940 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
2941 }
2942 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2943 name_str = "<no-name - thread is attaching>";
2944 } else {
2945 name_str = Thread::name();
2946 }
2947 } else {
2948 name_str = Thread::name();
2949 }
2950 assert(name_str != NULL, "unexpected NULL thread name");
2951 return name_str;
2952 }
2953
2954
2955 const char* JavaThread::get_threadgroup_name() const {
2956 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2957 oop thread_obj = threadObj();
2958 if (thread_obj != NULL) {
2959 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2960 if (thread_group != NULL) {
2961 // ThreadGroup.name can be null
2962 return java_lang_ThreadGroup::name(thread_group);
2963 }
2964 }
2965 return NULL;
2966 }
2967
2968 const char* JavaThread::get_parent_name() const {
2969 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2970 oop thread_obj = threadObj();
2971 if (thread_obj != NULL) {
2972 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2973 if (thread_group != NULL) {
2974 oop parent = java_lang_ThreadGroup::parent(thread_group);
2975 if (parent != NULL) {
2976 // ThreadGroup.name can be null
2977 return java_lang_ThreadGroup::name(parent);
2978 }
2979 }
2980 }
2981 return NULL;
2982 }
2983
2984 ThreadPriority JavaThread::java_priority() const {
2985 oop thr_oop = threadObj();
2986 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2987 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2988 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2989 return priority;
2990 }
2991
2992 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2993
2994 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2995 // Link Java Thread object <-> C++ Thread
2996
2997 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2998 // and put it into a new Handle. The Handle "thread_oop" can then
2999 // be used to pass the C++ thread object to other methods.
3000
3001 // Set the Java level thread object (jthread) field of the
3002 // new thread (a JavaThread *) to C++ thread object using the
3003 // "thread_oop" handle.
3004
3005 // Set the thread field (a JavaThread *) of the
3006 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
3007
3008 Handle thread_oop(Thread::current(),
3009 JNIHandles::resolve_non_null(jni_thread));
3010 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
3011 "must be initialized");
3012 set_threadObj(thread_oop());
3013 java_lang_Thread::set_thread(thread_oop(), this);
3014
3015 if (prio == NoPriority) {
3016 prio = java_lang_Thread::priority(thread_oop());
3017 assert(prio != NoPriority, "A valid priority should be present");
3018 }
3019
3020 // Push the Java priority down to the native thread; needs Threads_lock
3021 Thread::set_priority(this, prio);
3022
3023 prepare_ext();
3024
3025 // Add the new thread to the Threads list and set it in motion.
3026 // We must have threads lock in order to call Threads::add.
3027 // It is crucial that we do not block before the thread is
3028 // added to the Threads list for if a GC happens, then the java_thread oop
3029 // will not be visited by GC.
3030 Threads::add(this);
3031 }
3032
3033 oop JavaThread::current_park_blocker() {
3034 // Support for JSR-166 locks
3035 oop thread_oop = threadObj();
3036 if (thread_oop != NULL &&
3037 JDK_Version::current().supports_thread_park_blocker()) {
3038 return java_lang_Thread::park_blocker(thread_oop);
3039 }
3040 return NULL;
3041 }
3042
3043
3044 void JavaThread::print_stack_on(outputStream* st) {
3045 if (!has_last_Java_frame()) return;
3046 ResourceMark rm;
3047 HandleMark hm;
3048
3049 RegisterMap reg_map(this);
3050 vframe* start_vf = last_java_vframe(®_map);
3051 int count = 0;
3052 for (vframe* f = start_vf; f; f = f->sender()) {
3053 if (f->is_java_frame()) {
3054 javaVFrame* jvf = javaVFrame::cast(f);
3055 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
3056
3057 // Print out lock information
3058 if (JavaMonitorsInStackTrace) {
3059 jvf->print_lock_info_on(st, count);
3060 }
3061 } else {
3062 // Ignore non-Java frames
3063 }
3064
3065 // Bail-out case for too deep stacks
3066 count++;
3067 if (MaxJavaStackTraceDepth == count) return;
3068 }
3069 }
3070
3071
3072 // JVMTI PopFrame support
3073 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
3074 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
3075 if (in_bytes(size_in_bytes) != 0) {
3076 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
3077 _popframe_preserved_args_size = in_bytes(size_in_bytes);
3078 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
3079 }
3080 }
3081
3082 void* JavaThread::popframe_preserved_args() {
3083 return _popframe_preserved_args;
3084 }
3085
3086 ByteSize JavaThread::popframe_preserved_args_size() {
3087 return in_ByteSize(_popframe_preserved_args_size);
3088 }
3089
3090 WordSize JavaThread::popframe_preserved_args_size_in_words() {
3091 int sz = in_bytes(popframe_preserved_args_size());
3092 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
3093 return in_WordSize(sz / wordSize);
3094 }
3095
3096 void JavaThread::popframe_free_preserved_args() {
3097 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
3098 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args);
3099 _popframe_preserved_args = NULL;
3100 _popframe_preserved_args_size = 0;
3101 }
3102
3103 #ifndef PRODUCT
3104
3105 void JavaThread::trace_frames() {
3106 tty->print_cr("[Describe stack]");
3107 int frame_no = 1;
3108 for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
3109 tty->print(" %d. ", frame_no++);
3110 fst.current()->print_value_on(tty, this);
3111 tty->cr();
3112 }
3113 }
3114
3115 class PrintAndVerifyOopClosure: public OopClosure {
3116 protected:
3117 template <class T> inline void do_oop_work(T* p) {
3118 oop obj = oopDesc::load_decode_heap_oop(p);
3119 if (obj == NULL) return;
3120 tty->print(INTPTR_FORMAT ": ", p2i(p));
3121 if (obj->is_oop_or_null()) {
3122 if (obj->is_objArray()) {
3123 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
3124 } else {
3125 obj->print();
3126 }
3127 } else {
3128 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
3129 }
3130 tty->cr();
3131 }
3132 public:
3133 virtual void do_oop(oop* p) { do_oop_work(p); }
3134 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
3135 };
3136
3137
3138 static void oops_print(frame* f, const RegisterMap *map) {
3139 PrintAndVerifyOopClosure print;
3140 f->print_value();
3141 f->oops_do(&print, NULL, (RegisterMap*)map);
3142 }
3143
3144 // Print our all the locations that contain oops and whether they are
3145 // valid or not. This useful when trying to find the oldest frame
3146 // where an oop has gone bad since the frame walk is from youngest to
3147 // oldest.
3148 void JavaThread::trace_oops() {
3149 tty->print_cr("[Trace oops]");
3150 frames_do(oops_print);
3151 }
3152
3153
3154 #ifdef ASSERT
3155 // Print or validate the layout of stack frames
3156 void JavaThread::print_frame_layout(int depth, bool validate_only) {
3157 ResourceMark rm;
3158 PRESERVE_EXCEPTION_MARK;
3159 FrameValues values;
3160 int frame_no = 0;
3161 for (StackFrameStream fst(this, false); !fst.is_done(); fst.next()) {
3162 fst.current()->describe(values, ++frame_no);
3163 if (depth == frame_no) break;
3164 }
3165 if (validate_only) {
3166 values.validate();
3167 } else {
3168 tty->print_cr("[Describe stack layout]");
3169 values.print(this);
3170 }
3171 }
3172 #endif
3173
3174 void JavaThread::trace_stack_from(vframe* start_vf) {
3175 ResourceMark rm;
3176 int vframe_no = 1;
3177 for (vframe* f = start_vf; f; f = f->sender()) {
3178 if (f->is_java_frame()) {
3179 javaVFrame::cast(f)->print_activation(vframe_no++);
3180 } else {
3181 f->print();
3182 }
3183 if (vframe_no > StackPrintLimit) {
3184 tty->print_cr("...<more frames>...");
3185 return;
3186 }
3187 }
3188 }
3189
3190
3191 void JavaThread::trace_stack() {
3192 if (!has_last_Java_frame()) return;
3193 ResourceMark rm;
3194 HandleMark hm;
3195 RegisterMap reg_map(this);
3196 trace_stack_from(last_java_vframe(®_map));
3197 }
3198
3199
3200 #endif // PRODUCT
3201
3202
3203 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
3204 assert(reg_map != NULL, "a map must be given");
3205 frame f = last_frame();
3206 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
3207 if (vf->is_java_frame()) return javaVFrame::cast(vf);
3208 }
3209 return NULL;
3210 }
3211
3212
3213 Klass* JavaThread::security_get_caller_class(int depth) {
3214 vframeStream vfst(this);
3215 vfst.security_get_caller_frame(depth);
3216 if (!vfst.at_end()) {
3217 return vfst.method()->method_holder();
3218 }
3219 return NULL;
3220 }
3221
3222 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
3223 assert(thread->is_Compiler_thread(), "must be compiler thread");
3224 CompileBroker::compiler_thread_loop();
3225 }
3226
3227 static void sweeper_thread_entry(JavaThread* thread, TRAPS) {
3228 NMethodSweeper::sweeper_loop();
3229 }
3230
3231 // Create a CompilerThread
3232 CompilerThread::CompilerThread(CompileQueue* queue,
3233 CompilerCounters* counters)
3234 : JavaThread(&compiler_thread_entry) {
3235 _env = NULL;
3236 _log = NULL;
3237 _task = NULL;
3238 _queue = queue;
3239 _counters = counters;
3240 _buffer_blob = NULL;
3241 _compiler = NULL;
3242
3243 #ifndef PRODUCT
3244 _ideal_graph_printer = NULL;
3245 #endif
3246 }
3247
3248 bool CompilerThread::can_call_java() const {
3249 return _compiler != NULL && _compiler->is_jvmci();
3250 }
3251
3252 // Create sweeper thread
3253 CodeCacheSweeperThread::CodeCacheSweeperThread()
3254 : JavaThread(&sweeper_thread_entry) {
3255 _scanned_compiled_method = NULL;
3256 }
3257
3258 void CodeCacheSweeperThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3259 JavaThread::oops_do(f, cf);
3260 if (_scanned_compiled_method != NULL && cf != NULL) {
3261 // Safepoints can occur when the sweeper is scanning an nmethod so
3262 // process it here to make sure it isn't unloaded in the middle of
3263 // a scan.
3264 cf->do_code_blob(_scanned_compiled_method);
3265 }
3266 }
3267
3268 void CodeCacheSweeperThread::nmethods_do(CodeBlobClosure* cf) {
3269 JavaThread::nmethods_do(cf);
3270 if (_scanned_compiled_method != NULL && cf != NULL) {
3271 // Safepoints can occur when the sweeper is scanning an nmethod so
3272 // process it here to make sure it isn't unloaded in the middle of
3273 // a scan.
3274 cf->do_code_blob(_scanned_compiled_method);
3275 }
3276 }
3277
3278
3279 // ======= Threads ========
3280
3281 // The Threads class links together all active threads, and provides
3282 // operations over all threads. It is protected by its own Mutex
3283 // lock, which is also used in other contexts to protect thread
3284 // operations from having the thread being operated on from exiting
3285 // and going away unexpectedly (e.g., safepoint synchronization)
3286
3287 JavaThread* Threads::_thread_list = NULL;
3288 int Threads::_number_of_threads = 0;
3289 int Threads::_number_of_non_daemon_threads = 0;
3290 int Threads::_return_code = 0;
3291 int Threads::_thread_claim_parity = 0;
3292 size_t JavaThread::_stack_size_at_create = 0;
3293 #ifdef ASSERT
3294 bool Threads::_vm_complete = false;
3295 #endif
3296
3297 // All JavaThreads
3298 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
3299
3300 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
3301 void Threads::threads_do(ThreadClosure* tc) {
3302 assert_locked_or_safepoint(Threads_lock);
3303 // ALL_JAVA_THREADS iterates through all JavaThreads
3304 ALL_JAVA_THREADS(p) {
3305 tc->do_thread(p);
3306 }
3307 // Someday we could have a table or list of all non-JavaThreads.
3308 // For now, just manually iterate through them.
3309 tc->do_thread(VMThread::vm_thread());
3310 Universe::heap()->gc_threads_do(tc);
3311 WatcherThread *wt = WatcherThread::watcher_thread();
3312 // Strictly speaking, the following NULL check isn't sufficient to make sure
3313 // the data for WatcherThread is still valid upon being examined. However,
3314 // considering that WatchThread terminates when the VM is on the way to
3315 // exit at safepoint, the chance of the above is extremely small. The right
3316 // way to prevent termination of WatcherThread would be to acquire
3317 // Terminator_lock, but we can't do that without violating the lock rank
3318 // checking in some cases.
3319 if (wt != NULL) {
3320 tc->do_thread(wt);
3321 }
3322
3323 // If CompilerThreads ever become non-JavaThreads, add them here
3324 }
3325
3326 // The system initialization in the library has three phases.
3327 //
3328 // Phase 1: java.lang.System class initialization
3329 // java.lang.System is a primordial class loaded and initialized
3330 // by the VM early during startup. java.lang.System.<clinit>
3331 // only does registerNatives and keeps the rest of the class
3332 // initialization work later until thread initialization completes.
3333 //
3334 // System.initPhase1 initializes the system properties, the static
3335 // fields in, out, and err. Set up java signal handlers, OS-specific
3336 // system settings, and thread group of the main thread.
3337 static void call_initPhase1(TRAPS) {
3338 Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
3339 JavaValue result(T_VOID);
3340 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
3341 vmSymbols::void_method_signature(), CHECK);
3342 }
3343
3344 // Phase 2. Module system initialization
3345 // This will initialize the module system. Only java.base classes
3346 // can be loaded until phase 2 completes.
3347 //
3348 // Call System.initPhase2 after the compiler initialization and jsr292
3349 // classes get initialized because module initialization runs a lot of java
3350 // code, that for performance reasons, should be compiled. Also, this will
3351 // enable the startup code to use lambda and other language features in this
3352 // phase and onward.
3353 //
3354 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
3355 static void call_initPhase2(TRAPS) {
3356 TraceTime timer("Phase2 initialization", TRACETIME_LOG(Info, module, startuptime));
3357
3358 Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
3359
3360 JavaValue result(T_INT);
3361 JavaCallArguments args;
3362 args.push_int(DisplayVMOutputToStderr);
3363 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
3364 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
3365 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
3366 if (result.get_jint() != JNI_OK) {
3367 vm_exit_during_initialization(); // no message or exception
3368 }
3369
3370 universe_post_module_init();
3371 }
3372
3373 // Phase 3. final setup - set security manager, system class loader and TCCL
3374 //
3375 // This will instantiate and set the security manager, set the system class
3376 // loader as well as the thread context class loader. The security manager
3377 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
3378 // other modules or the application's classpath.
3379 static void call_initPhase3(TRAPS) {
3380 Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
3381 JavaValue result(T_VOID);
3382 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
3383 vmSymbols::void_method_signature(), CHECK);
3384 }
3385
3386 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
3387 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
3388
3389 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3390 create_vm_init_libraries();
3391 }
3392
3393 initialize_class(vmSymbols::java_lang_String(), CHECK);
3394
3395 // Inject CompactStrings value after the static initializers for String ran.
3396 java_lang_String::set_compact_strings(CompactStrings);
3397
3398 // Initialize java_lang.System (needed before creating the thread)
3399 initialize_class(vmSymbols::java_lang_System(), CHECK);
3400 // The VM creates & returns objects of this class. Make sure it's initialized.
3401 initialize_class(vmSymbols::java_lang_Class(), CHECK);
3402 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
3403 Handle thread_group = create_initial_thread_group(CHECK);
3404 Universe::set_main_thread_group(thread_group());
3405 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
3406 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK);
3407 main_thread->set_threadObj(thread_object);
3408 // Set thread status to running since main thread has
3409 // been started and running.
3410 java_lang_Thread::set_thread_status(thread_object,
3411 java_lang_Thread::RUNNABLE);
3412
3413 // The VM creates objects of this class.
3414 initialize_class(vmSymbols::java_lang_Module(), CHECK);
3415
3416 // The VM preresolves methods to these classes. Make sure that they get initialized
3417 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
3418 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
3419
3420 // Phase 1 of the system initialization in the library, java.lang.System class initialization
3421 call_initPhase1(CHECK);
3422
3423 // get the Java runtime name after java.lang.System is initialized
3424 JDK_Version::set_runtime_name(get_java_runtime_name(THREAD));
3425 JDK_Version::set_runtime_version(get_java_runtime_version(THREAD));
3426
3427 // an instance of OutOfMemory exception has been allocated earlier
3428 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
3429 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
3430 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
3431 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
3432 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
3433 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
3434 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
3435 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
3436 }
3437
3438 void Threads::initialize_jsr292_core_classes(TRAPS) {
3439 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
3440
3441 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
3442 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
3443 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
3444 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
3445 }
3446
3447 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
3448 extern void JDK_Version_init();
3449
3450 // Preinitialize version info.
3451 VM_Version::early_initialize();
3452
3453 // Check version
3454 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
3455
3456 // Initialize library-based TLS
3457 ThreadLocalStorage::init();
3458
3459 // Initialize the output stream module
3460 ostream_init();
3461
3462 // Process java launcher properties.
3463 Arguments::process_sun_java_launcher_properties(args);
3464
3465 // Initialize the os module
3466 os::init();
3467
3468 // Record VM creation timing statistics
3469 TraceVmCreationTime create_vm_timer;
3470 create_vm_timer.start();
3471
3472 // Initialize system properties.
3473 Arguments::init_system_properties();
3474
3475 // So that JDK version can be used as a discriminator when parsing arguments
3476 JDK_Version_init();
3477
3478 // Update/Initialize System properties after JDK version number is known
3479 Arguments::init_version_specific_system_properties();
3480
3481 // Make sure to initialize log configuration *before* parsing arguments
3482 LogConfiguration::initialize(create_vm_timer.begin_time());
3483
3484 // Parse arguments
3485 jint parse_result = Arguments::parse(args);
3486 if (parse_result != JNI_OK) return parse_result;
3487
3488 os::init_before_ergo();
3489
3490 jint ergo_result = Arguments::apply_ergo();
3491 if (ergo_result != JNI_OK) return ergo_result;
3492
3493 // Final check of all ranges after ergonomics which may change values.
3494 if (!CommandLineFlagRangeList::check_ranges()) {
3495 return JNI_EINVAL;
3496 }
3497
3498 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
3499 bool constraint_result = CommandLineFlagConstraintList::check_constraints(CommandLineFlagConstraint::AfterErgo);
3500 if (!constraint_result) {
3501 return JNI_EINVAL;
3502 }
3503
3504 CommandLineFlagWriteableList::mark_startup();
3505
3506 if (PauseAtStartup) {
3507 os::pause();
3508 }
3509
3510 HOTSPOT_VM_INIT_BEGIN();
3511
3512 // Timing (must come after argument parsing)
3513 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
3514
3515 // Initialize the os module after parsing the args
3516 jint os_init_2_result = os::init_2();
3517 if (os_init_2_result != JNI_OK) return os_init_2_result;
3518
3519 jint adjust_after_os_result = Arguments::adjust_after_os();
3520 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
3521
3522 // Initialize output stream logging
3523 ostream_init_log();
3524
3525 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
3526 // Must be before create_vm_init_agents()
3527 if (Arguments::init_libraries_at_startup()) {
3528 convert_vm_init_libraries_to_agents();
3529 }
3530
3531 // Launch -agentlib/-agentpath and converted -Xrun agents
3532 if (Arguments::init_agents_at_startup()) {
3533 create_vm_init_agents();
3534 }
3535
3536 // Initialize Threads state
3537 _thread_list = NULL;
3538 _number_of_threads = 0;
3539 _number_of_non_daemon_threads = 0;
3540
3541 // Initialize global data structures and create system classes in heap
3542 vm_init_globals();
3543
3544 #if INCLUDE_JVMCI
3545 if (JVMCICounterSize > 0) {
3546 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtInternal);
3547 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
3548 } else {
3549 JavaThread::_jvmci_old_thread_counters = NULL;
3550 }
3551 #endif // INCLUDE_JVMCI
3552
3553 // Attach the main thread to this os thread
3554 JavaThread* main_thread = new JavaThread();
3555 main_thread->set_thread_state(_thread_in_vm);
3556 main_thread->initialize_thread_current();
3557 // must do this before set_active_handles
3558 main_thread->record_stack_base_and_size();
3559 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
3560
3561 if (!main_thread->set_as_starting_thread()) {
3562 vm_shutdown_during_initialization(
3563 "Failed necessary internal allocation. Out of swap space");
3564 delete main_thread;
3565 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3566 return JNI_ENOMEM;
3567 }
3568
3569 // Enable guard page *after* os::create_main_thread(), otherwise it would
3570 // crash Linux VM, see notes in os_linux.cpp.
3571 main_thread->create_stack_guard_pages();
3572
3573 // Initialize Java-Level synchronization subsystem
3574 ObjectMonitor::Initialize();
3575
3576 // Initialize global modules
3577 jint status = init_globals();
3578 if (status != JNI_OK) {
3579 delete main_thread;
3580 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3581 return status;
3582 }
3583
3584 if (TRACE_INITIALIZE() != JNI_OK) {
3585 vm_exit_during_initialization("Failed to initialize tracing backend");
3586 }
3587
3588 // Should be done after the heap is fully created
3589 main_thread->cache_global_variables();
3590
3591 HandleMark hm;
3592
3593 { MutexLocker mu(Threads_lock);
3594 Threads::add(main_thread);
3595 }
3596
3597 // Any JVMTI raw monitors entered in onload will transition into
3598 // real raw monitor. VM is setup enough here for raw monitor enter.
3599 JvmtiExport::transition_pending_onload_raw_monitors();
3600
3601 // Create the VMThread
3602 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
3603
3604 VMThread::create();
3605 Thread* vmthread = VMThread::vm_thread();
3606
3607 if (!os::create_thread(vmthread, os::vm_thread)) {
3608 vm_exit_during_initialization("Cannot create VM thread. "
3609 "Out of system resources.");
3610 }
3611
3612 // Wait for the VM thread to become ready, and VMThread::run to initialize
3613 // Monitors can have spurious returns, must always check another state flag
3614 {
3615 MutexLocker ml(Notify_lock);
3616 os::start_thread(vmthread);
3617 while (vmthread->active_handles() == NULL) {
3618 Notify_lock->wait();
3619 }
3620 }
3621 }
3622
3623 assert(Universe::is_fully_initialized(), "not initialized");
3624 if (VerifyDuringStartup) {
3625 // Make sure we're starting with a clean slate.
3626 VM_Verify verify_op;
3627 VMThread::execute(&verify_op);
3628 }
3629
3630 Thread* THREAD = Thread::current();
3631
3632 // At this point, the Universe is initialized, but we have not executed
3633 // any byte code. Now is a good time (the only time) to dump out the
3634 // internal state of the JVM for sharing.
3635 if (DumpSharedSpaces) {
3636 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
3637 ShouldNotReachHere();
3638 }
3639
3640 // Always call even when there are not JVMTI environments yet, since environments
3641 // may be attached late and JVMTI must track phases of VM execution
3642 JvmtiExport::enter_early_start_phase();
3643
3644 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3645 JvmtiExport::post_early_vm_start();
3646
3647 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
3648
3649 // We need this for ClassDataSharing - the initial vm.info property is set
3650 // with the default value of CDS "sharing" which may be reset through
3651 // command line options.
3652 reset_vm_info_property(CHECK_JNI_ERR);
3653
3654 quicken_jni_functions();
3655
3656 // No more stub generation allowed after that point.
3657 StubCodeDesc::freeze();
3658
3659 // Set flag that basic initialization has completed. Used by exceptions and various
3660 // debug stuff, that does not work until all basic classes have been initialized.
3661 set_init_completed();
3662
3663 LogConfiguration::post_initialize();
3664 Metaspace::post_initialize();
3665
3666 HOTSPOT_VM_INIT_END();
3667
3668 // record VM initialization completion time
3669 #if INCLUDE_MANAGEMENT
3670 Management::record_vm_init_completed();
3671 #endif // INCLUDE_MANAGEMENT
3672
3673 // Signal Dispatcher needs to be started before VMInit event is posted
3674 os::signal_init(CHECK_JNI_ERR);
3675
3676 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3677 if (!DisableAttachMechanism) {
3678 AttachListener::vm_start();
3679 if (StartAttachListener || AttachListener::init_at_startup()) {
3680 AttachListener::init();
3681 }
3682 }
3683
3684 // Launch -Xrun agents
3685 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3686 // back-end can launch with -Xdebug -Xrunjdwp.
3687 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3688 create_vm_init_libraries();
3689 }
3690
3691 if (CleanChunkPoolAsync) {
3692 Chunk::start_chunk_pool_cleaner_task();
3693 }
3694
3695 // initialize compiler(s)
3696 #if defined(COMPILER1) || defined(COMPILER2) || defined(SHARK) || INCLUDE_JVMCI
3697 CompileBroker::compilation_init(CHECK_JNI_ERR);
3698 #endif
3699
3700 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
3701 // It is done after compilers are initialized, because otherwise compilations of
3702 // signature polymorphic MH intrinsics can be missed
3703 // (see SystemDictionary::find_method_handle_intrinsic).
3704 initialize_jsr292_core_classes(CHECK_JNI_ERR);
3705
3706 // This will initialize the module system. Only java.base classes can be
3707 // loaded until phase 2 completes
3708 call_initPhase2(CHECK_JNI_ERR);
3709
3710 // Always call even when there are not JVMTI environments yet, since environments
3711 // may be attached late and JVMTI must track phases of VM execution
3712 JvmtiExport::enter_start_phase();
3713
3714 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3715 JvmtiExport::post_vm_start();
3716
3717 // Final system initialization including security manager and system class loader
3718 call_initPhase3(CHECK_JNI_ERR);
3719
3720 // cache the system class loader
3721 SystemDictionary::compute_java_system_loader(CHECK_(JNI_ERR));
3722
3723 #if INCLUDE_JVMCI
3724 if (EnableJVMCI) {
3725 // Initialize JVMCI eagerly if JVMCIPrintProperties is enabled.
3726 // The JVMCI Java initialization code will read this flag and
3727 // do the printing if it's set.
3728 bool init = JVMCIPrintProperties;
3729
3730 if (!init) {
3731 // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking
3732 // compilations via JVMCI will not actually block until JVMCI is initialized.
3733 init = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation);
3734 }
3735
3736 if (init) {
3737 JVMCIRuntime::force_initialization(CHECK_JNI_ERR);
3738 }
3739 }
3740 #endif
3741
3742 // Always call even when there are not JVMTI environments yet, since environments
3743 // may be attached late and JVMTI must track phases of VM execution
3744 JvmtiExport::enter_live_phase();
3745
3746 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3747 JvmtiExport::post_vm_initialized();
3748
3749 if (TRACE_START() != JNI_OK) {
3750 vm_exit_during_initialization("Failed to start tracing backend.");
3751 }
3752
3753 #if INCLUDE_MANAGEMENT
3754 Management::initialize(THREAD);
3755
3756 if (HAS_PENDING_EXCEPTION) {
3757 // management agent fails to start possibly due to
3758 // configuration problem and is responsible for printing
3759 // stack trace if appropriate. Simply exit VM.
3760 vm_exit(1);
3761 }
3762 #endif // INCLUDE_MANAGEMENT
3763
3764 if (MemProfiling) MemProfiler::engage();
3765 StatSampler::engage();
3766 if (CheckJNICalls) JniPeriodicChecker::engage();
3767
3768 BiasedLocking::init();
3769
3770 #if INCLUDE_RTM_OPT
3771 RTMLockingCounters::init();
3772 #endif
3773
3774 if (JDK_Version::current().post_vm_init_hook_enabled()) {
3775 call_postVMInitHook(THREAD);
3776 // The Java side of PostVMInitHook.run must deal with all
3777 // exceptions and provide means of diagnosis.
3778 if (HAS_PENDING_EXCEPTION) {
3779 CLEAR_PENDING_EXCEPTION;
3780 }
3781 }
3782
3783 {
3784 MutexLocker ml(PeriodicTask_lock);
3785 // Make sure the WatcherThread can be started by WatcherThread::start()
3786 // or by dynamic enrollment.
3787 WatcherThread::make_startable();
3788 // Start up the WatcherThread if there are any periodic tasks
3789 // NOTE: All PeriodicTasks should be registered by now. If they
3790 // aren't, late joiners might appear to start slowly (we might
3791 // take a while to process their first tick).
3792 if (PeriodicTask::num_tasks() > 0) {
3793 WatcherThread::start();
3794 }
3795 }
3796
3797 create_vm_timer.end();
3798 #ifdef ASSERT
3799 _vm_complete = true;
3800 #endif
3801 return JNI_OK;
3802 }
3803
3804 // type for the Agent_OnLoad and JVM_OnLoad entry points
3805 extern "C" {
3806 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3807 }
3808 // Find a command line agent library and return its entry point for
3809 // -agentlib: -agentpath: -Xrun
3810 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3811 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent,
3812 const char *on_load_symbols[],
3813 size_t num_symbol_entries) {
3814 OnLoadEntry_t on_load_entry = NULL;
3815 void *library = NULL;
3816
3817 if (!agent->valid()) {
3818 char buffer[JVM_MAXPATHLEN];
3819 char ebuf[1024] = "";
3820 const char *name = agent->name();
3821 const char *msg = "Could not find agent library ";
3822
3823 // First check to see if agent is statically linked into executable
3824 if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
3825 library = agent->os_lib();
3826 } else if (agent->is_absolute_path()) {
3827 library = os::dll_load(name, ebuf, sizeof ebuf);
3828 if (library == NULL) {
3829 const char *sub_msg = " in absolute path, with error: ";
3830 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3831 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3832 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3833 // If we can't find the agent, exit.
3834 vm_exit_during_initialization(buf, NULL);
3835 FREE_C_HEAP_ARRAY(char, buf);
3836 }
3837 } else {
3838 // Try to load the agent from the standard dll directory
3839 if (os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
3840 name)) {
3841 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3842 }
3843 if (library == NULL) { // Try the local directory
3844 char ns[1] = {0};
3845 if (os::dll_build_name(buffer, sizeof(buffer), ns, name)) {
3846 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3847 }
3848 if (library == NULL) {
3849 const char *sub_msg = " on the library path, with error: ";
3850 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3851 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3852 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3853 // If we can't find the agent, exit.
3854 vm_exit_during_initialization(buf, NULL);
3855 FREE_C_HEAP_ARRAY(char, buf);
3856 }
3857 }
3858 }
3859 agent->set_os_lib(library);
3860 agent->set_valid();
3861 }
3862
3863 // Find the OnLoad function.
3864 on_load_entry =
3865 CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
3866 false,
3867 on_load_symbols,
3868 num_symbol_entries));
3869 return on_load_entry;
3870 }
3871
3872 // Find the JVM_OnLoad entry point
3873 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3874 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3875 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3876 }
3877
3878 // Find the Agent_OnLoad entry point
3879 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3880 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3881 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3882 }
3883
3884 // For backwards compatibility with -Xrun
3885 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3886 // treated like -agentpath:
3887 // Must be called before agent libraries are created
3888 void Threads::convert_vm_init_libraries_to_agents() {
3889 AgentLibrary* agent;
3890 AgentLibrary* next;
3891
3892 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3893 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3894 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3895
3896 // If there is an JVM_OnLoad function it will get called later,
3897 // otherwise see if there is an Agent_OnLoad
3898 if (on_load_entry == NULL) {
3899 on_load_entry = lookup_agent_on_load(agent);
3900 if (on_load_entry != NULL) {
3901 // switch it to the agent list -- so that Agent_OnLoad will be called,
3902 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3903 Arguments::convert_library_to_agent(agent);
3904 } else {
3905 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3906 }
3907 }
3908 }
3909 }
3910
3911 // Create agents for -agentlib: -agentpath: and converted -Xrun
3912 // Invokes Agent_OnLoad
3913 // Called very early -- before JavaThreads exist
3914 void Threads::create_vm_init_agents() {
3915 extern struct JavaVM_ main_vm;
3916 AgentLibrary* agent;
3917
3918 JvmtiExport::enter_onload_phase();
3919
3920 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3921 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3922
3923 if (on_load_entry != NULL) {
3924 // Invoke the Agent_OnLoad function
3925 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3926 if (err != JNI_OK) {
3927 vm_exit_during_initialization("agent library failed to init", agent->name());
3928 }
3929 } else {
3930 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3931 }
3932 }
3933 JvmtiExport::enter_primordial_phase();
3934 }
3935
3936 extern "C" {
3937 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3938 }
3939
3940 void Threads::shutdown_vm_agents() {
3941 // Send any Agent_OnUnload notifications
3942 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3943 size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
3944 extern struct JavaVM_ main_vm;
3945 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3946
3947 // Find the Agent_OnUnload function.
3948 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3949 os::find_agent_function(agent,
3950 false,
3951 on_unload_symbols,
3952 num_symbol_entries));
3953
3954 // Invoke the Agent_OnUnload function
3955 if (unload_entry != NULL) {
3956 JavaThread* thread = JavaThread::current();
3957 ThreadToNativeFromVM ttn(thread);
3958 HandleMark hm(thread);
3959 (*unload_entry)(&main_vm);
3960 }
3961 }
3962 }
3963
3964 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3965 // Invokes JVM_OnLoad
3966 void Threads::create_vm_init_libraries() {
3967 extern struct JavaVM_ main_vm;
3968 AgentLibrary* agent;
3969
3970 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3971 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3972
3973 if (on_load_entry != NULL) {
3974 // Invoke the JVM_OnLoad function
3975 JavaThread* thread = JavaThread::current();
3976 ThreadToNativeFromVM ttn(thread);
3977 HandleMark hm(thread);
3978 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3979 if (err != JNI_OK) {
3980 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3981 }
3982 } else {
3983 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3984 }
3985 }
3986 }
3987
3988 JavaThread* Threads::find_java_thread_from_java_tid(jlong java_tid) {
3989 assert(Threads_lock->owned_by_self(), "Must hold Threads_lock");
3990
3991 JavaThread* java_thread = NULL;
3992 // Sequential search for now. Need to do better optimization later.
3993 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
3994 oop tobj = thread->threadObj();
3995 if (!thread->is_exiting() &&
3996 tobj != NULL &&
3997 java_tid == java_lang_Thread::thread_id(tobj)) {
3998 java_thread = thread;
3999 break;
4000 }
4001 }
4002 return java_thread;
4003 }
4004
4005
4006 // Last thread running calls java.lang.Shutdown.shutdown()
4007 void JavaThread::invoke_shutdown_hooks() {
4008 HandleMark hm(this);
4009
4010 // We could get here with a pending exception, if so clear it now.
4011 if (this->has_pending_exception()) {
4012 this->clear_pending_exception();
4013 }
4014
4015 EXCEPTION_MARK;
4016 Klass* shutdown_klass =
4017 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
4018 THREAD);
4019 if (shutdown_klass != NULL) {
4020 // SystemDictionary::resolve_or_null will return null if there was
4021 // an exception. If we cannot load the Shutdown class, just don't
4022 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
4023 // and finalizers (if runFinalizersOnExit is set) won't be run.
4024 // Note that if a shutdown hook was registered or runFinalizersOnExit
4025 // was called, the Shutdown class would have already been loaded
4026 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
4027 JavaValue result(T_VOID);
4028 JavaCalls::call_static(&result,
4029 shutdown_klass,
4030 vmSymbols::shutdown_method_name(),
4031 vmSymbols::void_method_signature(),
4032 THREAD);
4033 }
4034 CLEAR_PENDING_EXCEPTION;
4035 }
4036
4037 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
4038 // the program falls off the end of main(). Another VM exit path is through
4039 // vm_exit() when the program calls System.exit() to return a value or when
4040 // there is a serious error in VM. The two shutdown paths are not exactly
4041 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
4042 // and VM_Exit op at VM level.
4043 //
4044 // Shutdown sequence:
4045 // + Shutdown native memory tracking if it is on
4046 // + Wait until we are the last non-daemon thread to execute
4047 // <-- every thing is still working at this moment -->
4048 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
4049 // shutdown hooks, run finalizers if finalization-on-exit
4050 // + Call before_exit(), prepare for VM exit
4051 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
4052 // currently the only user of this mechanism is File.deleteOnExit())
4053 // > stop StatSampler, watcher thread, CMS threads,
4054 // post thread end and vm death events to JVMTI,
4055 // stop signal thread
4056 // + Call JavaThread::exit(), it will:
4057 // > release JNI handle blocks, remove stack guard pages
4058 // > remove this thread from Threads list
4059 // <-- no more Java code from this thread after this point -->
4060 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
4061 // the compiler threads at safepoint
4062 // <-- do not use anything that could get blocked by Safepoint -->
4063 // + Disable tracing at JNI/JVM barriers
4064 // + Set _vm_exited flag for threads that are still running native code
4065 // + Delete this thread
4066 // + Call exit_globals()
4067 // > deletes tty
4068 // > deletes PerfMemory resources
4069 // + Return to caller
4070
4071 bool Threads::destroy_vm() {
4072 JavaThread* thread = JavaThread::current();
4073
4074 #ifdef ASSERT
4075 _vm_complete = false;
4076 #endif
4077 // Wait until we are the last non-daemon thread to execute
4078 { MutexLocker nu(Threads_lock);
4079 while (Threads::number_of_non_daemon_threads() > 1)
4080 // This wait should make safepoint checks, wait without a timeout,
4081 // and wait as a suspend-equivalent condition.
4082 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
4083 Mutex::_as_suspend_equivalent_flag);
4084 }
4085
4086 // Hang forever on exit if we are reporting an error.
4087 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
4088 os::infinite_sleep();
4089 }
4090 os::wait_for_keypress_at_exit();
4091
4092 // run Java level shutdown hooks
4093 thread->invoke_shutdown_hooks();
4094
4095 before_exit(thread);
4096
4097 thread->exit(true);
4098
4099 // Stop VM thread.
4100 {
4101 // 4945125 The vm thread comes to a safepoint during exit.
4102 // GC vm_operations can get caught at the safepoint, and the
4103 // heap is unparseable if they are caught. Grab the Heap_lock
4104 // to prevent this. The GC vm_operations will not be able to
4105 // queue until after the vm thread is dead. After this point,
4106 // we'll never emerge out of the safepoint before the VM exits.
4107
4108 MutexLocker ml(Heap_lock);
4109
4110 VMThread::wait_for_vm_thread_exit();
4111 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
4112 VMThread::destroy();
4113 }
4114
4115 // clean up ideal graph printers
4116 #if defined(COMPILER2) && !defined(PRODUCT)
4117 IdealGraphPrinter::clean_up();
4118 #endif
4119
4120 // Now, all Java threads are gone except daemon threads. Daemon threads
4121 // running Java code or in VM are stopped by the Safepoint. However,
4122 // daemon threads executing native code are still running. But they
4123 // will be stopped at native=>Java/VM barriers. Note that we can't
4124 // simply kill or suspend them, as it is inherently deadlock-prone.
4125
4126 VM_Exit::set_vm_exited();
4127
4128 notify_vm_shutdown();
4129
4130 delete thread;
4131
4132 #if INCLUDE_JVMCI
4133 if (JVMCICounterSize > 0) {
4134 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
4135 }
4136 #endif
4137
4138 // exit_globals() will delete tty
4139 exit_globals();
4140
4141 LogConfiguration::finalize();
4142
4143 return true;
4144 }
4145
4146
4147 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
4148 if (version == JNI_VERSION_1_1) return JNI_TRUE;
4149 return is_supported_jni_version(version);
4150 }
4151
4152
4153 jboolean Threads::is_supported_jni_version(jint version) {
4154 if (version == JNI_VERSION_1_2) return JNI_TRUE;
4155 if (version == JNI_VERSION_1_4) return JNI_TRUE;
4156 if (version == JNI_VERSION_1_6) return JNI_TRUE;
4157 if (version == JNI_VERSION_1_8) return JNI_TRUE;
4158 if (version == JNI_VERSION_9) return JNI_TRUE;
4159 return JNI_FALSE;
4160 }
4161
4162
4163 void Threads::add(JavaThread* p, bool force_daemon) {
4164 // The threads lock must be owned at this point
4165 assert_locked_or_safepoint(Threads_lock);
4166
4167 // See the comment for this method in thread.hpp for its purpose and
4168 // why it is called here.
4169 p->initialize_queues();
4170 p->set_next(_thread_list);
4171 _thread_list = p;
4172 _number_of_threads++;
4173 oop threadObj = p->threadObj();
4174 bool daemon = true;
4175 // Bootstrapping problem: threadObj can be null for initial
4176 // JavaThread (or for threads attached via JNI)
4177 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
4178 _number_of_non_daemon_threads++;
4179 daemon = false;
4180 }
4181
4182 ThreadService::add_thread(p, daemon);
4183
4184 // Possible GC point.
4185 Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
4186 }
4187
4188 void Threads::remove(JavaThread* p) {
4189
4190 // Reclaim the objectmonitors from the omInUseList and omFreeList of the moribund thread.
4191 ObjectSynchronizer::omFlush(p);
4192
4193 // Extra scope needed for Thread_lock, so we can check
4194 // that we do not remove thread without safepoint code notice
4195 { MutexLocker ml(Threads_lock);
4196
4197 assert(includes(p), "p must be present");
4198
4199 JavaThread* current = _thread_list;
4200 JavaThread* prev = NULL;
4201
4202 while (current != p) {
4203 prev = current;
4204 current = current->next();
4205 }
4206
4207 if (prev) {
4208 prev->set_next(current->next());
4209 } else {
4210 _thread_list = p->next();
4211 }
4212 _number_of_threads--;
4213 oop threadObj = p->threadObj();
4214 bool daemon = true;
4215 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
4216 _number_of_non_daemon_threads--;
4217 daemon = false;
4218
4219 // Only one thread left, do a notify on the Threads_lock so a thread waiting
4220 // on destroy_vm will wake up.
4221 if (number_of_non_daemon_threads() == 1) {
4222 Threads_lock->notify_all();
4223 }
4224 }
4225 ThreadService::remove_thread(p, daemon);
4226
4227 // Make sure that safepoint code disregard this thread. This is needed since
4228 // the thread might mess around with locks after this point. This can cause it
4229 // to do callbacks into the safepoint code. However, the safepoint code is not aware
4230 // of this thread since it is removed from the queue.
4231 p->set_terminated_value();
4232 } // unlock Threads_lock
4233
4234 // Since Events::log uses a lock, we grab it outside the Threads_lock
4235 Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
4236 }
4237
4238 // Threads_lock must be held when this is called (or must be called during a safepoint)
4239 bool Threads::includes(JavaThread* p) {
4240 assert(Threads_lock->is_locked(), "sanity check");
4241 ALL_JAVA_THREADS(q) {
4242 if (q == p) {
4243 return true;
4244 }
4245 }
4246 return false;
4247 }
4248
4249 // Operations on the Threads list for GC. These are not explicitly locked,
4250 // but the garbage collector must provide a safe context for them to run.
4251 // In particular, these things should never be called when the Threads_lock
4252 // is held by some other thread. (Note: the Safepoint abstraction also
4253 // uses the Threads_lock to guarantee this property. It also makes sure that
4254 // all threads gets blocked when exiting or starting).
4255
4256 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
4257 ALL_JAVA_THREADS(p) {
4258 p->oops_do(f, cf);
4259 }
4260 VMThread::vm_thread()->oops_do(f, cf);
4261 }
4262
4263 void Threads::change_thread_claim_parity() {
4264 // Set the new claim parity.
4265 assert(_thread_claim_parity >= 0 && _thread_claim_parity <= 2,
4266 "Not in range.");
4267 _thread_claim_parity++;
4268 if (_thread_claim_parity == 3) _thread_claim_parity = 1;
4269 assert(_thread_claim_parity >= 1 && _thread_claim_parity <= 2,
4270 "Not in range.");
4271 }
4272
4273 #ifdef ASSERT
4274 void Threads::assert_all_threads_claimed() {
4275 ALL_JAVA_THREADS(p) {
4276 const int thread_parity = p->oops_do_parity();
4277 assert((thread_parity == _thread_claim_parity),
4278 "Thread " PTR_FORMAT " has incorrect parity %d != %d", p2i(p), thread_parity, _thread_claim_parity);
4279 }
4280 }
4281 #endif // ASSERT
4282
4283 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) {
4284 int cp = Threads::thread_claim_parity();
4285 ALL_JAVA_THREADS(p) {
4286 if (p->claim_oops_do(is_par, cp)) {
4287 p->oops_do(f, cf);
4288 }
4289 }
4290 VMThread* vmt = VMThread::vm_thread();
4291 if (vmt->claim_oops_do(is_par, cp)) {
4292 vmt->oops_do(f, cf);
4293 }
4294 }
4295
4296 #if INCLUDE_ALL_GCS
4297 // Used by ParallelScavenge
4298 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
4299 ALL_JAVA_THREADS(p) {
4300 q->enqueue(new ThreadRootsTask(p));
4301 }
4302 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
4303 }
4304
4305 // Used by Parallel Old
4306 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
4307 ALL_JAVA_THREADS(p) {
4308 q->enqueue(new ThreadRootsMarkingTask(p));
4309 }
4310 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
4311 }
4312 #endif // INCLUDE_ALL_GCS
4313
4314 void Threads::nmethods_do(CodeBlobClosure* cf) {
4315 ALL_JAVA_THREADS(p) {
4316 // This is used by the code cache sweeper to mark nmethods that are active
4317 // on the stack of a Java thread. Ignore the sweeper thread itself to avoid
4318 // marking CodeCacheSweeperThread::_scanned_compiled_method as active.
4319 if(!p->is_Code_cache_sweeper_thread()) {
4320 p->nmethods_do(cf);
4321 }
4322 }
4323 }
4324
4325 void Threads::metadata_do(void f(Metadata*)) {
4326 ALL_JAVA_THREADS(p) {
4327 p->metadata_do(f);
4328 }
4329 }
4330
4331 class ThreadHandlesClosure : public ThreadClosure {
4332 void (*_f)(Metadata*);
4333 public:
4334 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
4335 virtual void do_thread(Thread* thread) {
4336 thread->metadata_handles_do(_f);
4337 }
4338 };
4339
4340 void Threads::metadata_handles_do(void f(Metadata*)) {
4341 // Only walk the Handles in Thread.
4342 ThreadHandlesClosure handles_closure(f);
4343 threads_do(&handles_closure);
4344 }
4345
4346 void Threads::deoptimized_wrt_marked_nmethods() {
4347 ALL_JAVA_THREADS(p) {
4348 p->deoptimized_wrt_marked_nmethods();
4349 }
4350 }
4351
4352
4353 // Get count Java threads that are waiting to enter the specified monitor.
4354 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
4355 address monitor,
4356 bool doLock) {
4357 assert(doLock || SafepointSynchronize::is_at_safepoint(),
4358 "must grab Threads_lock or be at safepoint");
4359 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
4360
4361 int i = 0;
4362 {
4363 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4364 ALL_JAVA_THREADS(p) {
4365 if (!p->can_call_java()) continue;
4366
4367 address pending = (address)p->current_pending_monitor();
4368 if (pending == monitor) { // found a match
4369 if (i < count) result->append(p); // save the first count matches
4370 i++;
4371 }
4372 }
4373 }
4374 return result;
4375 }
4376
4377
4378 JavaThread *Threads::owning_thread_from_monitor_owner(address owner,
4379 bool doLock) {
4380 assert(doLock ||
4381 Threads_lock->owned_by_self() ||
4382 SafepointSynchronize::is_at_safepoint(),
4383 "must grab Threads_lock or be at safepoint");
4384
4385 // NULL owner means not locked so we can skip the search
4386 if (owner == NULL) return NULL;
4387
4388 {
4389 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4390 ALL_JAVA_THREADS(p) {
4391 // first, see if owner is the address of a Java thread
4392 if (owner == (address)p) return p;
4393 }
4394 }
4395 // Cannot assert on lack of success here since this function may be
4396 // used by code that is trying to report useful problem information
4397 // like deadlock detection.
4398 if (UseHeavyMonitors) return NULL;
4399
4400 // If we didn't find a matching Java thread and we didn't force use of
4401 // heavyweight monitors, then the owner is the stack address of the
4402 // Lock Word in the owning Java thread's stack.
4403 //
4404 JavaThread* the_owner = NULL;
4405 {
4406 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4407 ALL_JAVA_THREADS(q) {
4408 if (q->is_lock_owned(owner)) {
4409 the_owner = q;
4410 break;
4411 }
4412 }
4413 }
4414 // cannot assert on lack of success here; see above comment
4415 return the_owner;
4416 }
4417
4418 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
4419 void Threads::print_on(outputStream* st, bool print_stacks,
4420 bool internal_format, bool print_concurrent_locks) {
4421 char buf[32];
4422 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
4423
4424 st->print_cr("Full thread dump %s (%s %s):",
4425 Abstract_VM_Version::vm_name(),
4426 Abstract_VM_Version::vm_release(),
4427 Abstract_VM_Version::vm_info_string());
4428 st->cr();
4429
4430 #if INCLUDE_SERVICES
4431 // Dump concurrent locks
4432 ConcurrentLocksDump concurrent_locks;
4433 if (print_concurrent_locks) {
4434 concurrent_locks.dump_at_safepoint();
4435 }
4436 #endif // INCLUDE_SERVICES
4437
4438 ALL_JAVA_THREADS(p) {
4439 ResourceMark rm;
4440 p->print_on(st);
4441 if (print_stacks) {
4442 if (internal_format) {
4443 p->trace_stack();
4444 } else {
4445 p->print_stack_on(st);
4446 }
4447 }
4448 st->cr();
4449 #if INCLUDE_SERVICES
4450 if (print_concurrent_locks) {
4451 concurrent_locks.print_locks_on(p, st);
4452 }
4453 #endif // INCLUDE_SERVICES
4454 }
4455
4456 VMThread::vm_thread()->print_on(st);
4457 st->cr();
4458 Universe::heap()->print_gc_threads_on(st);
4459 WatcherThread* wt = WatcherThread::watcher_thread();
4460 if (wt != NULL) {
4461 wt->print_on(st);
4462 st->cr();
4463 }
4464 st->flush();
4465 }
4466
4467 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
4468 int buflen, bool* found_current) {
4469 if (this_thread != NULL) {
4470 bool is_current = (current == this_thread);
4471 *found_current = *found_current || is_current;
4472 st->print("%s", is_current ? "=>" : " ");
4473
4474 st->print(PTR_FORMAT, p2i(this_thread));
4475 st->print(" ");
4476 this_thread->print_on_error(st, buf, buflen);
4477 st->cr();
4478 }
4479 }
4480
4481 class PrintOnErrorClosure : public ThreadClosure {
4482 outputStream* _st;
4483 Thread* _current;
4484 char* _buf;
4485 int _buflen;
4486 bool* _found_current;
4487 public:
4488 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
4489 int buflen, bool* found_current) :
4490 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
4491
4492 virtual void do_thread(Thread* thread) {
4493 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
4494 }
4495 };
4496
4497 // Threads::print_on_error() is called by fatal error handler. It's possible
4498 // that VM is not at safepoint and/or current thread is inside signal handler.
4499 // Don't print stack trace, as the stack may not be walkable. Don't allocate
4500 // memory (even in resource area), it might deadlock the error handler.
4501 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
4502 int buflen) {
4503 bool found_current = false;
4504 st->print_cr("Java Threads: ( => current thread )");
4505 ALL_JAVA_THREADS(thread) {
4506 print_on_error(thread, st, current, buf, buflen, &found_current);
4507 }
4508 st->cr();
4509
4510 st->print_cr("Other Threads:");
4511 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
4512 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
4513
4514 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
4515 Universe::heap()->gc_threads_do(&print_closure);
4516
4517 if (!found_current) {
4518 st->cr();
4519 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
4520 current->print_on_error(st, buf, buflen);
4521 st->cr();
4522 }
4523 st->cr();
4524 st->print_cr("Threads with active compile tasks:");
4525 print_threads_compiling(st, buf, buflen);
4526 }
4527
4528 void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen) {
4529 ALL_JAVA_THREADS(thread) {
4530 if (thread->is_Compiler_thread()) {
4531 CompilerThread* ct = (CompilerThread*) thread;
4532 if (ct->task() != NULL) {
4533 thread->print_name_on_error(st, buf, buflen);
4534 ct->task()->print(st, NULL, true, true);
4535 }
4536 }
4537 }
4538 }
4539
4540
4541 // Internal SpinLock and Mutex
4542 // Based on ParkEvent
4543
4544 // Ad-hoc mutual exclusion primitives: SpinLock and Mux
4545 //
4546 // We employ SpinLocks _only for low-contention, fixed-length
4547 // short-duration critical sections where we're concerned
4548 // about native mutex_t or HotSpot Mutex:: latency.
4549 // The mux construct provides a spin-then-block mutual exclusion
4550 // mechanism.
4551 //
4552 // Testing has shown that contention on the ListLock guarding gFreeList
4553 // is common. If we implement ListLock as a simple SpinLock it's common
4554 // for the JVM to devolve to yielding with little progress. This is true
4555 // despite the fact that the critical sections protected by ListLock are
4556 // extremely short.
4557 //
4558 // TODO-FIXME: ListLock should be of type SpinLock.
4559 // We should make this a 1st-class type, integrated into the lock
4560 // hierarchy as leaf-locks. Critically, the SpinLock structure
4561 // should have sufficient padding to avoid false-sharing and excessive
4562 // cache-coherency traffic.
4563
4564
4565 typedef volatile int SpinLockT;
4566
4567 void Thread::SpinAcquire(volatile int * adr, const char * LockName) {
4568 if (Atomic::cmpxchg (1, adr, 0) == 0) {
4569 return; // normal fast-path return
4570 }
4571
4572 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
4573 TEVENT(SpinAcquire - ctx);
4574 int ctr = 0;
4575 int Yields = 0;
4576 for (;;) {
4577 while (*adr != 0) {
4578 ++ctr;
4579 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
4580 if (Yields > 5) {
4581 os::naked_short_sleep(1);
4582 } else {
4583 os::naked_yield();
4584 ++Yields;
4585 }
4586 } else {
4587 SpinPause();
4588 }
4589 }
4590 if (Atomic::cmpxchg(1, adr, 0) == 0) return;
4591 }
4592 }
4593
4594 void Thread::SpinRelease(volatile int * adr) {
4595 assert(*adr != 0, "invariant");
4596 OrderAccess::fence(); // guarantee at least release consistency.
4597 // Roach-motel semantics.
4598 // It's safe if subsequent LDs and STs float "up" into the critical section,
4599 // but prior LDs and STs within the critical section can't be allowed
4600 // to reorder or float past the ST that releases the lock.
4601 // Loads and stores in the critical section - which appear in program
4602 // order before the store that releases the lock - must also appear
4603 // before the store that releases the lock in memory visibility order.
4604 // Conceptually we need a #loadstore|#storestore "release" MEMBAR before
4605 // the ST of 0 into the lock-word which releases the lock, so fence
4606 // more than covers this on all platforms.
4607 *adr = 0;
4608 }
4609
4610 // muxAcquire and muxRelease:
4611 //
4612 // * muxAcquire and muxRelease support a single-word lock-word construct.
4613 // The LSB of the word is set IFF the lock is held.
4614 // The remainder of the word points to the head of a singly-linked list
4615 // of threads blocked on the lock.
4616 //
4617 // * The current implementation of muxAcquire-muxRelease uses its own
4618 // dedicated Thread._MuxEvent instance. If we're interested in
4619 // minimizing the peak number of extant ParkEvent instances then
4620 // we could eliminate _MuxEvent and "borrow" _ParkEvent as long
4621 // as certain invariants were satisfied. Specifically, care would need
4622 // to be taken with regards to consuming unpark() "permits".
4623 // A safe rule of thumb is that a thread would never call muxAcquire()
4624 // if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently
4625 // park(). Otherwise the _ParkEvent park() operation in muxAcquire() could
4626 // consume an unpark() permit intended for monitorenter, for instance.
4627 // One way around this would be to widen the restricted-range semaphore
4628 // implemented in park(). Another alternative would be to provide
4629 // multiple instances of the PlatformEvent() for each thread. One
4630 // instance would be dedicated to muxAcquire-muxRelease, for instance.
4631 //
4632 // * Usage:
4633 // -- Only as leaf locks
4634 // -- for short-term locking only as muxAcquire does not perform
4635 // thread state transitions.
4636 //
4637 // Alternatives:
4638 // * We could implement muxAcquire and muxRelease with MCS or CLH locks
4639 // but with parking or spin-then-park instead of pure spinning.
4640 // * Use Taura-Oyama-Yonenzawa locks.
4641 // * It's possible to construct a 1-0 lock if we encode the lockword as
4642 // (List,LockByte). Acquire will CAS the full lockword while Release
4643 // will STB 0 into the LockByte. The 1-0 scheme admits stranding, so
4644 // acquiring threads use timers (ParkTimed) to detect and recover from
4645 // the stranding window. Thread/Node structures must be aligned on 256-byte
4646 // boundaries by using placement-new.
4647 // * Augment MCS with advisory back-link fields maintained with CAS().
4648 // Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner.
4649 // The validity of the backlinks must be ratified before we trust the value.
4650 // If the backlinks are invalid the exiting thread must back-track through the
4651 // the forward links, which are always trustworthy.
4652 // * Add a successor indication. The LockWord is currently encoded as
4653 // (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable
4654 // to provide the usual futile-wakeup optimization.
4655 // See RTStt for details.
4656 // * Consider schedctl.sc_nopreempt to cover the critical section.
4657 //
4658
4659
4660 typedef volatile intptr_t MutexT; // Mux Lock-word
4661 enum MuxBits { LOCKBIT = 1 };
4662
4663 void Thread::muxAcquire(volatile intptr_t * Lock, const char * LockName) {
4664 intptr_t w = Atomic::cmpxchg_ptr(LOCKBIT, Lock, 0);
4665 if (w == 0) return;
4666 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4667 return;
4668 }
4669
4670 TEVENT(muxAcquire - Contention);
4671 ParkEvent * const Self = Thread::current()->_MuxEvent;
4672 assert((intptr_t(Self) & LOCKBIT) == 0, "invariant");
4673 for (;;) {
4674 int its = (os::is_MP() ? 100 : 0) + 1;
4675
4676 // Optional spin phase: spin-then-park strategy
4677 while (--its >= 0) {
4678 w = *Lock;
4679 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4680 return;
4681 }
4682 }
4683
4684 Self->reset();
4685 Self->OnList = intptr_t(Lock);
4686 // The following fence() isn't _strictly necessary as the subsequent
4687 // CAS() both serializes execution and ratifies the fetched *Lock value.
4688 OrderAccess::fence();
4689 for (;;) {
4690 w = *Lock;
4691 if ((w & LOCKBIT) == 0) {
4692 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4693 Self->OnList = 0; // hygiene - allows stronger asserts
4694 return;
4695 }
4696 continue; // Interference -- *Lock changed -- Just retry
4697 }
4698 assert(w & LOCKBIT, "invariant");
4699 Self->ListNext = (ParkEvent *) (w & ~LOCKBIT);
4700 if (Atomic::cmpxchg_ptr(intptr_t(Self)|LOCKBIT, Lock, w) == w) break;
4701 }
4702
4703 while (Self->OnList != 0) {
4704 Self->park();
4705 }
4706 }
4707 }
4708
4709 void Thread::muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev) {
4710 intptr_t w = Atomic::cmpxchg_ptr(LOCKBIT, Lock, 0);
4711 if (w == 0) return;
4712 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4713 return;
4714 }
4715
4716 TEVENT(muxAcquire - Contention);
4717 ParkEvent * ReleaseAfter = NULL;
4718 if (ev == NULL) {
4719 ev = ReleaseAfter = ParkEvent::Allocate(NULL);
4720 }
4721 assert((intptr_t(ev) & LOCKBIT) == 0, "invariant");
4722 for (;;) {
4723 guarantee(ev->OnList == 0, "invariant");
4724 int its = (os::is_MP() ? 100 : 0) + 1;
4725
4726 // Optional spin phase: spin-then-park strategy
4727 while (--its >= 0) {
4728 w = *Lock;
4729 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4730 if (ReleaseAfter != NULL) {
4731 ParkEvent::Release(ReleaseAfter);
4732 }
4733 return;
4734 }
4735 }
4736
4737 ev->reset();
4738 ev->OnList = intptr_t(Lock);
4739 // The following fence() isn't _strictly necessary as the subsequent
4740 // CAS() both serializes execution and ratifies the fetched *Lock value.
4741 OrderAccess::fence();
4742 for (;;) {
4743 w = *Lock;
4744 if ((w & LOCKBIT) == 0) {
4745 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4746 ev->OnList = 0;
4747 // We call ::Release while holding the outer lock, thus
4748 // artificially lengthening the critical section.
4749 // Consider deferring the ::Release() until the subsequent unlock(),
4750 // after we've dropped the outer lock.
4751 if (ReleaseAfter != NULL) {
4752 ParkEvent::Release(ReleaseAfter);
4753 }
4754 return;
4755 }
4756 continue; // Interference -- *Lock changed -- Just retry
4757 }
4758 assert(w & LOCKBIT, "invariant");
4759 ev->ListNext = (ParkEvent *) (w & ~LOCKBIT);
4760 if (Atomic::cmpxchg_ptr(intptr_t(ev)|LOCKBIT, Lock, w) == w) break;
4761 }
4762
4763 while (ev->OnList != 0) {
4764 ev->park();
4765 }
4766 }
4767 }
4768
4769 // Release() must extract a successor from the list and then wake that thread.
4770 // It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme
4771 // similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based
4772 // Release() would :
4773 // (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list.
4774 // (B) Extract a successor from the private list "in-hand"
4775 // (C) attempt to CAS() the residual back into *Lock over null.
4776 // If there were any newly arrived threads and the CAS() would fail.
4777 // In that case Release() would detach the RATs, re-merge the list in-hand
4778 // with the RATs and repeat as needed. Alternately, Release() might
4779 // detach and extract a successor, but then pass the residual list to the wakee.
4780 // The wakee would be responsible for reattaching and remerging before it
4781 // competed for the lock.
4782 //
4783 // Both "pop" and DMR are immune from ABA corruption -- there can be
4784 // multiple concurrent pushers, but only one popper or detacher.
4785 // This implementation pops from the head of the list. This is unfair,
4786 // but tends to provide excellent throughput as hot threads remain hot.
4787 // (We wake recently run threads first).
4788 //
4789 // All paths through muxRelease() will execute a CAS.
4790 // Release consistency -- We depend on the CAS in muxRelease() to provide full
4791 // bidirectional fence/MEMBAR semantics, ensuring that all prior memory operations
4792 // executed within the critical section are complete and globally visible before the
4793 // store (CAS) to the lock-word that releases the lock becomes globally visible.
4794 void Thread::muxRelease(volatile intptr_t * Lock) {
4795 for (;;) {
4796 const intptr_t w = Atomic::cmpxchg_ptr(0, Lock, LOCKBIT);
4797 assert(w & LOCKBIT, "invariant");
4798 if (w == LOCKBIT) return;
4799 ParkEvent * const List = (ParkEvent *) (w & ~LOCKBIT);
4800 assert(List != NULL, "invariant");
4801 assert(List->OnList == intptr_t(Lock), "invariant");
4802 ParkEvent * const nxt = List->ListNext;
4803 guarantee((intptr_t(nxt) & LOCKBIT) == 0, "invariant");
4804
4805 // The following CAS() releases the lock and pops the head element.
4806 // The CAS() also ratifies the previously fetched lock-word value.
4807 if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) {
4808 continue;
4809 }
4810 List->OnList = 0;
4811 OrderAccess::fence();
4812 List->unpark();
4813 return;
4814 }
4815 }
4816
4817
4818 void Threads::verify() {
4819 ALL_JAVA_THREADS(p) {
4820 p->verify();
4821 }
4822 VMThread* thread = VMThread::vm_thread();
4823 if (thread != NULL) thread->verify();
4824 }