1 /*
2 * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "jvm.h"
28 #include "cds/dynamicArchive.hpp"
29 #include "cds/metaspaceShared.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/javaClasses.hpp"
32 #include "classfile/javaThreadStatus.hpp"
33 #include "classfile/systemDictionary.hpp"
34 #include "classfile/vmClasses.hpp"
35 #include "classfile/vmSymbols.hpp"
36 #include "code/codeCache.hpp"
37 #include "code/scopeDesc.hpp"
38 #include "compiler/compileBroker.hpp"
39 #include "compiler/compileTask.hpp"
40 #include "compiler/compilerThread.hpp"
41 #include "gc/shared/barrierSet.hpp"
42 #include "gc/shared/collectedHeap.hpp"
43 #include "gc/shared/gcId.hpp"
44 #include "gc/shared/gcLocker.inline.hpp"
45 #include "gc/shared/gcVMOperations.hpp"
46 #include "gc/shared/oopStorage.hpp"
47 #include "gc/shared/oopStorageSet.hpp"
48 #include "gc/shared/stringdedup/stringDedup.hpp"
49 #include "gc/shared/tlab_globals.hpp"
50 #include "interpreter/interpreter.hpp"
51 #include "interpreter/linkResolver.hpp"
52 #include "interpreter/oopMapCache.hpp"
53 #include "jfr/jfrEvents.hpp"
54 #include "jvmtifiles/jvmtiEnv.hpp"
55 #include "logging/log.hpp"
56 #include "logging/logAsyncWriter.hpp"
57 #include "logging/logConfiguration.hpp"
58 #include "logging/logStream.hpp"
59 #include "memory/allocation.inline.hpp"
60 #include "memory/iterator.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "oops/access.inline.hpp"
65 #include "oops/instanceKlass.hpp"
66 #include "oops/klass.inline.hpp"
67 #include "oops/objArrayOop.hpp"
68 #include "oops/oop.inline.hpp"
69 #include "oops/oopHandle.inline.hpp"
70 #include "oops/symbol.hpp"
71 #include "oops/typeArrayOop.inline.hpp"
72 #include "oops/verifyOopClosure.hpp"
73 #include "prims/jvm_misc.hpp"
74 #include "prims/jvmtiDeferredUpdates.hpp"
75 #include "prims/jvmtiExport.hpp"
76 #include "prims/jvmtiThreadState.hpp"
77 #include "runtime/arguments.hpp"
78 #include "runtime/atomic.hpp"
79 #include "runtime/biasedLocking.hpp"
80 #include "runtime/fieldDescriptor.inline.hpp"
81 #include "runtime/flags/jvmFlagLimit.hpp"
82 #include "runtime/deoptimization.hpp"
83 #include "runtime/frame.inline.hpp"
84 #include "runtime/handles.inline.hpp"
85 #include "runtime/handshake.hpp"
86 #include "runtime/init.hpp"
87 #include "runtime/interfaceSupport.inline.hpp"
88 #include "runtime/java.hpp"
89 #include "runtime/javaCalls.hpp"
90 #include "runtime/jniHandles.inline.hpp"
91 #include "runtime/jniPeriodicChecker.hpp"
92 #include "runtime/monitorDeflationThread.hpp"
93 #include "runtime/mutexLocker.hpp"
94 #include "runtime/nonJavaThread.hpp"
95 #include "runtime/objectMonitor.hpp"
96 #include "runtime/orderAccess.hpp"
97 #include "runtime/osThread.hpp"
98 #include "runtime/prefetch.inline.hpp"
99 #include "runtime/safepoint.hpp"
100 #include "runtime/safepointMechanism.inline.hpp"
101 #include "runtime/safepointVerifiers.hpp"
102 #include "runtime/serviceThread.hpp"
103 #include "runtime/sharedRuntime.hpp"
104 #include "runtime/stackFrameStream.inline.hpp"
105 #include "runtime/stackWatermarkSet.hpp"
106 #include "runtime/statSampler.hpp"
107 #include "runtime/task.hpp"
108 #include "runtime/thread.inline.hpp"
109 #include "runtime/threadCritical.hpp"
110 #include "runtime/threadSMR.inline.hpp"
111 #include "runtime/threadStatisticalInfo.hpp"
112 #include "runtime/threadWXSetters.inline.hpp"
113 #include "runtime/timer.hpp"
114 #include "runtime/timerTrace.hpp"
115 #include "runtime/vframe.inline.hpp"
116 #include "runtime/vframeArray.hpp"
117 #include "runtime/vframe_hp.hpp"
118 #include "runtime/vmThread.hpp"
119 #include "runtime/vmOperations.hpp"
120 #include "runtime/vm_version.hpp"
121 #include "services/attachListener.hpp"
122 #include "services/management.hpp"
123 #include "services/memTracker.hpp"
124 #include "services/threadService.hpp"
125 #include "utilities/align.hpp"
126 #include "utilities/copy.hpp"
127 #include "utilities/defaultStream.hpp"
128 #include "utilities/dtrace.hpp"
129 #include "utilities/events.hpp"
130 #include "utilities/macros.hpp"
131 #include "utilities/preserveException.hpp"
132 #include "utilities/spinYield.hpp"
133 #include "utilities/vmError.hpp"
134 #if INCLUDE_JVMCI
135 #include "jvmci/jvmci.hpp"
136 #include "jvmci/jvmciEnv.hpp"
137 #endif
138 #ifdef COMPILER1
139 #include "c1/c1_Compiler.hpp"
140 #endif
141 #ifdef COMPILER2
142 #include "opto/c2compiler.hpp"
143 #include "opto/idealGraphPrinter.hpp"
144 #endif
145 #if INCLUDE_RTM_OPT
146 #include "runtime/rtmLocking.hpp"
147 #endif
148 #if INCLUDE_JFR
149 #include "jfr/jfr.hpp"
150 #endif
151
152 // Initialization after module runtime initialization
153 void universe_post_module_init(); // must happen after call_initPhase2
154
155 #ifdef DTRACE_ENABLED
156
157 // Only bother with this argument setup if dtrace is available
158
159 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
160 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
161
162 #define DTRACE_THREAD_PROBE(probe, javathread) \
163 { \
164 ResourceMark rm(this); \
165 int len = 0; \
166 const char* name = (javathread)->get_thread_name(); \
167 len = strlen(name); \
168 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
169 (char *) name, len, \
170 java_lang_Thread::thread_id((javathread)->threadObj()), \
171 (uintptr_t) (javathread)->osthread()->thread_id(), \
172 java_lang_Thread::is_daemon((javathread)->threadObj())); \
173 }
174
175 #else // ndef DTRACE_ENABLED
176
177 #define DTRACE_THREAD_PROBE(probe, javathread)
178
179 #endif // ndef DTRACE_ENABLED
180
181 #ifndef USE_LIBRARY_BASED_TLS_ONLY
182 // Current thread is maintained as a thread-local variable
183 THREAD_LOCAL Thread* Thread::_thr_current = NULL;
184 #endif
185
186 // ======= Thread ========
187 // Support for forcing alignment of thread objects for biased locking
188 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
189 if (UseBiasedLocking) {
190 const size_t alignment = markWord::biased_lock_alignment;
191 size_t aligned_size = size + (alignment - sizeof(intptr_t));
192 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
193 : AllocateHeap(aligned_size, flags, CURRENT_PC,
194 AllocFailStrategy::RETURN_NULL);
195 void* aligned_addr = align_up(real_malloc_addr, alignment);
196 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
197 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
198 "JavaThread alignment code overflowed allocated storage");
199 if (aligned_addr != real_malloc_addr) {
200 log_info(biasedlocking)("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
201 p2i(real_malloc_addr),
202 p2i(aligned_addr));
203 }
204 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
205 return aligned_addr;
206 } else {
207 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
208 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
209 }
210 }
211
212 void Thread::operator delete(void* p) {
213 if (UseBiasedLocking) {
214 FreeHeap(((Thread*) p)->_real_malloc_address);
215 } else {
216 FreeHeap(p);
217 }
218 }
219
220 void JavaThread::smr_delete() {
221 if (_on_thread_list) {
222 ThreadsSMRSupport::smr_delete(this);
223 } else {
224 delete this;
225 }
226 }
227
228 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
229 // JavaThread
230
231 DEBUG_ONLY(Thread* Thread::_starting_thread = NULL;)
232
233 Thread::Thread() {
234
235 DEBUG_ONLY(_run_state = PRE_CALL_RUN;)
236
237 // stack and get_thread
238 set_stack_base(NULL);
239 set_stack_size(0);
240 set_lgrp_id(-1);
241 DEBUG_ONLY(clear_suspendible_thread();)
242
243 // allocated data structures
244 set_osthread(NULL);
245 set_resource_area(new (mtThread)ResourceArea());
246 DEBUG_ONLY(_current_resource_mark = NULL;)
247 set_handle_area(new (mtThread) HandleArea(NULL));
248 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, mtClass));
249 set_active_handles(NULL);
250 set_free_handle_block(NULL);
251 set_last_handle_mark(NULL);
252 DEBUG_ONLY(_missed_ic_stub_refill_verifier = NULL);
253
254 // Initial value of zero ==> never claimed.
255 _threads_do_token = 0;
256 _threads_hazard_ptr = NULL;
257 _threads_list_ptr = NULL;
258 _nested_threads_hazard_ptr_cnt = 0;
259 _rcu_counter = 0;
260
261 // the handle mark links itself to last_handle_mark
262 new HandleMark(this);
263
264 // plain initialization
265 debug_only(_owned_locks = NULL;)
266 NOT_PRODUCT(_skip_gcalot = false;)
267 _jvmti_env_iteration_count = 0;
268 set_allocated_bytes(0);
269 _current_pending_raw_monitor = NULL;
270
271 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
272 _hashStateX = os::random();
273 _hashStateY = 842502087;
274 _hashStateZ = 0x8767; // (int)(3579807591LL & 0xffff) ;
275 _hashStateW = 273326509;
276
277 // Many of the following fields are effectively final - immutable
278 // Note that nascent threads can't use the Native Monitor-Mutex
279 // construct until the _MutexEvent is initialized ...
280 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
281 // we might instead use a stack of ParkEvents that we could provision on-demand.
282 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
283 // and ::Release()
284 _ParkEvent = ParkEvent::Allocate(this);
285
286 #ifdef CHECK_UNHANDLED_OOPS
287 if (CheckUnhandledOops) {
288 _unhandled_oops = new UnhandledOops(this);
289 }
290 #endif // CHECK_UNHANDLED_OOPS
291 #ifdef ASSERT
292 if (UseBiasedLocking) {
293 assert(is_aligned(this, markWord::biased_lock_alignment), "forced alignment of thread object failed");
294 assert(this == _real_malloc_address ||
295 this == align_up(_real_malloc_address, markWord::biased_lock_alignment),
296 "bug in forced alignment of thread objects");
297 }
298 #endif // ASSERT
299
300 // Notify the barrier set that a thread is being created. The initial
301 // thread is created before the barrier set is available. The call to
302 // BarrierSet::on_thread_create() for this thread is therefore deferred
303 // to BarrierSet::set_barrier_set().
304 BarrierSet* const barrier_set = BarrierSet::barrier_set();
305 if (barrier_set != NULL) {
306 barrier_set->on_thread_create(this);
307 } else {
308 // Only the main thread should be created before the barrier set
309 // and that happens just before Thread::current is set. No other thread
310 // can attach as the VM is not created yet, so they can't execute this code.
311 // If the main thread creates other threads before the barrier set that is an error.
312 assert(Thread::current_or_null() == NULL, "creating thread before barrier set");
313 }
314
315 MACOS_AARCH64_ONLY(DEBUG_ONLY(_wx_init = false));
316 }
317
318 void Thread::initialize_tlab() {
319 if (UseTLAB) {
320 tlab().initialize();
321 }
322 }
323
324 void Thread::initialize_thread_current() {
325 #ifndef USE_LIBRARY_BASED_TLS_ONLY
326 assert(_thr_current == NULL, "Thread::current already initialized");
327 _thr_current = this;
328 #endif
329 assert(ThreadLocalStorage::thread() == NULL, "ThreadLocalStorage::thread already initialized");
330 ThreadLocalStorage::set_thread(this);
331 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
332 }
333
334 void Thread::clear_thread_current() {
335 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
336 #ifndef USE_LIBRARY_BASED_TLS_ONLY
337 _thr_current = NULL;
338 #endif
339 ThreadLocalStorage::set_thread(NULL);
340 }
341
342 void Thread::record_stack_base_and_size() {
343 // Note: at this point, Thread object is not yet initialized. Do not rely on
344 // any members being initialized. Do not rely on Thread::current() being set.
345 // If possible, refrain from doing anything which may crash or assert since
346 // quite probably those crash dumps will be useless.
347 set_stack_base(os::current_stack_base());
348 set_stack_size(os::current_stack_size());
349
350 // Set stack limits after thread is initialized.
351 if (is_Java_thread()) {
352 as_Java_thread()->stack_overflow_state()->initialize(stack_base(), stack_end());
353 }
354 }
355
356 #if INCLUDE_NMT
357 void Thread::register_thread_stack_with_NMT() {
358 MemTracker::record_thread_stack(stack_end(), stack_size());
359 }
360
361 void Thread::unregister_thread_stack_with_NMT() {
362 MemTracker::release_thread_stack(stack_end(), stack_size());
363 }
364 #endif // INCLUDE_NMT
365
366 void Thread::call_run() {
367 DEBUG_ONLY(_run_state = CALL_RUN;)
368
369 // At this point, Thread object should be fully initialized and
370 // Thread::current() should be set.
371
372 assert(Thread::current_or_null() != NULL, "current thread is unset");
373 assert(Thread::current_or_null() == this, "current thread is wrong");
374
375 // Perform common initialization actions
376
377 MACOS_AARCH64_ONLY(this->init_wx());
378
379 register_thread_stack_with_NMT();
380
381 JFR_ONLY(Jfr::on_thread_start(this);)
382
383 log_debug(os, thread)("Thread " UINTX_FORMAT " stack dimensions: "
384 PTR_FORMAT "-" PTR_FORMAT " (" SIZE_FORMAT "k).",
385 os::current_thread_id(), p2i(stack_end()),
386 p2i(stack_base()), stack_size()/1024);
387
388 // Perform <ChildClass> initialization actions
389 DEBUG_ONLY(_run_state = PRE_RUN;)
390 this->pre_run();
391
392 // Invoke <ChildClass>::run()
393 DEBUG_ONLY(_run_state = RUN;)
394 this->run();
395 // Returned from <ChildClass>::run(). Thread finished.
396
397 // Perform common tear-down actions
398
399 assert(Thread::current_or_null() != NULL, "current thread is unset");
400 assert(Thread::current_or_null() == this, "current thread is wrong");
401
402 // Perform <ChildClass> tear-down actions
403 DEBUG_ONLY(_run_state = POST_RUN;)
404 this->post_run();
405
406 // Note: at this point the thread object may already have deleted itself,
407 // so from here on do not dereference *this*. Not all thread types currently
408 // delete themselves when they terminate. But no thread should ever be deleted
409 // asynchronously with respect to its termination - that is what _run_state can
410 // be used to check.
411
412 assert(Thread::current_or_null() == NULL, "current thread still present");
413 }
414
415 Thread::~Thread() {
416
417 // Attached threads will remain in PRE_CALL_RUN, as will threads that don't actually
418 // get started due to errors etc. Any active thread should at least reach post_run
419 // before it is deleted (usually in post_run()).
420 assert(_run_state == PRE_CALL_RUN ||
421 _run_state == POST_RUN, "Active Thread deleted before post_run(): "
422 "_run_state=%d", (int)_run_state);
423
424 // Notify the barrier set that a thread is being destroyed. Note that a barrier
425 // set might not be available if we encountered errors during bootstrapping.
426 BarrierSet* const barrier_set = BarrierSet::barrier_set();
427 if (barrier_set != NULL) {
428 barrier_set->on_thread_destroy(this);
429 }
430
431 // deallocate data structures
432 delete resource_area();
433 // since the handle marks are using the handle area, we have to deallocated the root
434 // handle mark before deallocating the thread's handle area,
435 assert(last_handle_mark() != NULL, "check we have an element");
436 delete last_handle_mark();
437 assert(last_handle_mark() == NULL, "check we have reached the end");
438
439 ParkEvent::Release(_ParkEvent);
440 // Set to NULL as a termination indicator for has_terminated().
441 Atomic::store(&_ParkEvent, (ParkEvent*)NULL);
442
443 delete handle_area();
444 delete metadata_handles();
445
446 // osthread() can be NULL, if creation of thread failed.
447 if (osthread() != NULL) os::free_thread(osthread());
448
449 // Clear Thread::current if thread is deleting itself and it has not
450 // already been done. This must be done before the memory is deallocated.
451 // Needed to ensure JNI correctly detects non-attached threads.
452 if (this == Thread::current_or_null()) {
453 Thread::clear_thread_current();
454 }
455
456 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
457 }
458
459 #ifdef ASSERT
460 // A JavaThread is considered dangling if it not handshake-safe with respect to
461 // the current thread, it is not on a ThreadsList, or not at safepoint.
462 void Thread::check_for_dangling_thread_pointer(Thread *thread) {
463 assert(!thread->is_Java_thread() ||
464 thread->as_Java_thread()->is_handshake_safe_for(Thread::current()) ||
465 !thread->as_Java_thread()->on_thread_list() ||
466 SafepointSynchronize::is_at_safepoint() ||
467 ThreadsSMRSupport::is_a_protected_JavaThread_with_lock(thread->as_Java_thread()),
468 "possibility of dangling Thread pointer");
469 }
470 #endif
471
472 // Is the target JavaThread protected by the calling Thread
473 // or by some other mechanism:
474 bool Thread::is_JavaThread_protected(const JavaThread* p) {
475 // Do the simplest check first:
476 if (SafepointSynchronize::is_at_safepoint()) {
477 // The target is protected since JavaThreads cannot exit
478 // while we're at a safepoint.
479 return true;
480 }
481
482 // If the target hasn't been started yet then it is trivially
483 // "protected". We assume the caller is the thread that will do
484 // the starting.
485 if (p->osthread() == NULL || p->osthread()->get_state() <= INITIALIZED) {
486 return true;
487 }
488
489 // Now make the simple checks based on who the caller is:
490 Thread* current_thread = Thread::current();
491 if (current_thread == p || Threads_lock->owner() == current_thread) {
492 // Target JavaThread is self or calling thread owns the Threads_lock.
493 // Second check is the same as Threads_lock->owner_is_self(),
494 // but we already have the current thread so check directly.
495 return true;
496 }
497
498 // Check the ThreadsLists associated with the calling thread (if any)
499 // to see if one of them protects the target JavaThread:
500 for (SafeThreadsListPtr* stlp = current_thread->_threads_list_ptr;
501 stlp != NULL; stlp = stlp->previous()) {
502 if (stlp->list()->includes(p)) {
503 // The target JavaThread is protected by this ThreadsList:
504 return true;
505 }
506 }
507
508 // Use this debug code with -XX:+UseNewCode to diagnose locations that
509 // are missing a ThreadsListHandle or other protection mechanism:
510 // guarantee(!UseNewCode, "current_thread=" INTPTR_FORMAT " is not protecting p="
511 // INTPTR_FORMAT, p2i(current_thread), p2i(p));
512
513 // Note: Since 'p' isn't protected by a TLH, the call to
514 // p->is_handshake_safe_for() may crash, but we have debug bits so
515 // we'll be able to figure out what protection mechanism is missing.
516 assert(p->is_handshake_safe_for(current_thread), "JavaThread=" INTPTR_FORMAT
517 " is not protected and not handshake safe.", p2i(p));
518
519 // The target JavaThread is not protected so it is not safe to query:
520 return false;
521 }
522
523 ThreadPriority Thread::get_priority(const Thread* const thread) {
524 ThreadPriority priority;
525 // Can return an error!
526 (void)os::get_priority(thread, priority);
527 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
528 return priority;
529 }
530
531 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
532 debug_only(check_for_dangling_thread_pointer(thread);)
533 // Can return an error!
534 (void)os::set_priority(thread, priority);
535 }
536
537
538 void Thread::start(Thread* thread) {
539 // Start is different from resume in that its safety is guaranteed by context or
540 // being called from a Java method synchronized on the Thread object.
541 if (thread->is_Java_thread()) {
542 // Initialize the thread state to RUNNABLE before starting this thread.
543 // Can not set it after the thread started because we do not know the
544 // exact thread state at that time. It could be in MONITOR_WAIT or
545 // in SLEEPING or some other state.
546 java_lang_Thread::set_thread_status(thread->as_Java_thread()->threadObj(),
547 JavaThreadStatus::RUNNABLE);
548 }
549 os::start_thread(thread);
550 }
551
552 // GC Support
553 bool Thread::claim_par_threads_do(uintx claim_token) {
554 uintx token = _threads_do_token;
555 if (token != claim_token) {
556 uintx res = Atomic::cmpxchg(&_threads_do_token, token, claim_token);
557 if (res == token) {
558 return true;
559 }
560 guarantee(res == claim_token, "invariant");
561 }
562 return false;
563 }
564
565 void Thread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
566 if (active_handles() != NULL) {
567 active_handles()->oops_do(f);
568 }
569 // Do oop for ThreadShadow
570 f->do_oop((oop*)&_pending_exception);
571 handle_area()->oops_do(f);
572 }
573
574 // If the caller is a NamedThread, then remember, in the current scope,
575 // the given JavaThread in its _processed_thread field.
576 class RememberProcessedThread: public StackObj {
577 NamedThread* _cur_thr;
578 public:
579 RememberProcessedThread(Thread* thread) {
580 Thread* self = Thread::current();
581 if (self->is_Named_thread()) {
582 _cur_thr = (NamedThread *)self;
583 assert(_cur_thr->processed_thread() == NULL, "nesting not supported");
584 _cur_thr->set_processed_thread(thread);
585 } else {
586 _cur_thr = NULL;
587 }
588 }
589
590 ~RememberProcessedThread() {
591 if (_cur_thr) {
592 assert(_cur_thr->processed_thread() != NULL, "nesting not supported");
593 _cur_thr->set_processed_thread(NULL);
594 }
595 }
596 };
597
598 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
599 // Record JavaThread to GC thread
600 RememberProcessedThread rpt(this);
601 oops_do_no_frames(f, cf);
602 oops_do_frames(f, cf);
603 }
604
605 void Thread::metadata_handles_do(void f(Metadata*)) {
606 // Only walk the Handles in Thread.
607 if (metadata_handles() != NULL) {
608 for (int i = 0; i< metadata_handles()->length(); i++) {
609 f(metadata_handles()->at(i));
610 }
611 }
612 }
613
614 void Thread::print_on(outputStream* st, bool print_extended_info) const {
615 // get_priority assumes osthread initialized
616 if (osthread() != NULL) {
617 int os_prio;
618 if (os::get_native_priority(this, &os_prio) == OS_OK) {
619 st->print("os_prio=%d ", os_prio);
620 }
621
622 st->print("cpu=%.2fms ",
623 os::thread_cpu_time(const_cast<Thread*>(this), true) / 1000000.0
624 );
625 st->print("elapsed=%.2fs ",
626 _statistical_info.getElapsedTime() / 1000.0
627 );
628 if (is_Java_thread() && (PrintExtendedThreadInfo || print_extended_info)) {
629 size_t allocated_bytes = (size_t) const_cast<Thread*>(this)->cooked_allocated_bytes();
630 st->print("allocated=" SIZE_FORMAT "%s ",
631 byte_size_in_proper_unit(allocated_bytes),
632 proper_unit_for_byte_size(allocated_bytes)
633 );
634 st->print("defined_classes=" INT64_FORMAT " ", _statistical_info.getDefineClassCount());
635 }
636
637 st->print("tid=" INTPTR_FORMAT " ", p2i(this));
638 osthread()->print_on(st);
639 }
640 ThreadsSMRSupport::print_info_on(this, st);
641 st->print(" ");
642 debug_only(if (WizardMode) print_owned_locks_on(st);)
643 }
644
645 void Thread::print() const { print_on(tty); }
646
647 // Thread::print_on_error() is called by fatal error handler. Don't use
648 // any lock or allocate memory.
649 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
650 assert(!(is_Compiler_thread() || is_Java_thread()), "Can't call name() here if it allocates");
651
652 if (is_VM_thread()) { st->print("VMThread"); }
653 else if (is_GC_task_thread()) { st->print("GCTaskThread"); }
654 else if (is_Watcher_thread()) { st->print("WatcherThread"); }
655 else if (is_ConcurrentGC_thread()) { st->print("ConcurrentGCThread"); }
656 else { st->print("Thread"); }
657
658 if (is_Named_thread()) {
659 st->print(" \"%s\"", name());
660 }
661
662 OSThread* os_thr = osthread();
663 if (os_thr != NULL) {
664 if (os_thr->get_state() != ZOMBIE) {
665 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
666 p2i(stack_end()), p2i(stack_base()));
667 st->print(" [id=%d]", osthread()->thread_id());
668 } else {
669 st->print(" terminated");
670 }
671 } else {
672 st->print(" unknown state (no osThread)");
673 }
674 ThreadsSMRSupport::print_info_on(this, st);
675 }
676
677 void Thread::print_value_on(outputStream* st) const {
678 if (is_Named_thread()) {
679 st->print(" \"%s\" ", name());
680 }
681 st->print(INTPTR_FORMAT, p2i(this)); // print address
682 }
683
684 #ifdef ASSERT
685 void Thread::print_owned_locks_on(outputStream* st) const {
686 Mutex* cur = _owned_locks;
687 if (cur == NULL) {
688 st->print(" (no locks) ");
689 } else {
690 st->print_cr(" Locks owned:");
691 while (cur) {
692 cur->print_on(st);
693 cur = cur->next();
694 }
695 }
696 }
697 #endif // ASSERT
698
699 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
700 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
701 // used for compilation in the future. If that change is made, the need for these methods
702 // should be revisited, and they should be removed if possible.
703
704 bool Thread::is_lock_owned(address adr) const {
705 return is_in_full_stack(adr);
706 }
707
708 bool Thread::set_as_starting_thread() {
709 assert(_starting_thread == NULL, "already initialized: "
710 "_starting_thread=" INTPTR_FORMAT, p2i(_starting_thread));
711 // NOTE: this must be called inside the main thread.
712 DEBUG_ONLY(_starting_thread = this;)
713 return os::create_main_thread(this->as_Java_thread());
714 }
715
716 static void initialize_class(Symbol* class_name, TRAPS) {
717 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
718 InstanceKlass::cast(klass)->initialize(CHECK);
719 }
720
721
722 // Creates the initial ThreadGroup
723 static Handle create_initial_thread_group(TRAPS) {
724 Handle system_instance = JavaCalls::construct_new_instance(
725 vmClasses::ThreadGroup_klass(),
726 vmSymbols::void_method_signature(),
727 CHECK_NH);
728 Universe::set_system_thread_group(system_instance());
729
730 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
731 Handle main_instance = JavaCalls::construct_new_instance(
732 vmClasses::ThreadGroup_klass(),
733 vmSymbols::threadgroup_string_void_signature(),
734 system_instance,
735 string,
736 CHECK_NH);
737 return main_instance;
738 }
739
740 // Creates the initial Thread, and sets it to running.
741 static void create_initial_thread(Handle thread_group, JavaThread* thread,
742 TRAPS) {
743 InstanceKlass* ik = vmClasses::Thread_klass();
744 assert(ik->is_initialized(), "must be");
745 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
746
747 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
748 // constructor calls Thread.current(), which must be set here for the
749 // initial thread.
750 java_lang_Thread::set_thread(thread_oop(), thread);
751 java_lang_Thread::set_priority(thread_oop(), NormPriority);
752 thread->set_threadObj(thread_oop());
753
754 Handle string = java_lang_String::create_from_str("main", CHECK);
755
756 JavaValue result(T_VOID);
757 JavaCalls::call_special(&result, thread_oop,
758 ik,
759 vmSymbols::object_initializer_name(),
760 vmSymbols::threadgroup_string_void_signature(),
761 thread_group,
762 string,
763 CHECK);
764
765 // Set thread status to running since main thread has
766 // been started and running.
767 java_lang_Thread::set_thread_status(thread_oop(),
768 JavaThreadStatus::RUNNABLE);
769 }
770
771 // Extract version and vendor specific information from
772 // java.lang.VersionProps fields.
773 // Returned char* is allocated in the thread's resource area
774 // so must be copied for permanency.
775 static const char* get_java_version_info(InstanceKlass* ik,
776 Symbol* field_name) {
777 fieldDescriptor fd;
778 bool found = ik != NULL &&
779 ik->find_local_field(field_name,
780 vmSymbols::string_signature(), &fd);
781 if (found) {
782 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
783 if (name_oop == NULL) {
784 return NULL;
785 }
786 const char* name = java_lang_String::as_utf8_string(name_oop);
787 return name;
788 } else {
789 return NULL;
790 }
791 }
792
793 // General purpose hook into Java code, run once when the VM is initialized.
794 // The Java library method itself may be changed independently from the VM.
795 static void call_postVMInitHook(TRAPS) {
796 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
797 if (klass != NULL) {
798 JavaValue result(T_VOID);
799 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
800 vmSymbols::void_method_signature(),
801 CHECK);
802 }
803 }
804
805 // Initialized by VMThread at vm_global_init
806 static OopStorage* _thread_oop_storage = NULL;
807
808 oop JavaThread::threadObj() const {
809 return _threadObj.resolve();
810 }
811
812 void JavaThread::set_threadObj(oop p) {
813 assert(_thread_oop_storage != NULL, "not yet initialized");
814 _threadObj = OopHandle(_thread_oop_storage, p);
815 }
816
817 OopStorage* JavaThread::thread_oop_storage() {
818 assert(_thread_oop_storage != NULL, "not yet initialized");
819 return _thread_oop_storage;
820 }
821
822 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
823 bool daemon, TRAPS) {
824 assert(thread_group.not_null(), "thread group should be specified");
825 assert(threadObj() == NULL, "should only create Java thread object once");
826
827 InstanceKlass* ik = vmClasses::Thread_klass();
828 assert(ik->is_initialized(), "must be");
829 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
830
831 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
832 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
833 // constructor calls Thread.current(), which must be set here.
834 java_lang_Thread::set_thread(thread_oop(), this);
835 java_lang_Thread::set_priority(thread_oop(), NormPriority);
836 set_threadObj(thread_oop());
837
838 JavaValue result(T_VOID);
839 if (thread_name != NULL) {
840 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
841 // Thread gets assigned specified name and null target
842 JavaCalls::call_special(&result,
843 thread_oop,
844 ik,
845 vmSymbols::object_initializer_name(),
846 vmSymbols::threadgroup_string_void_signature(),
847 thread_group,
848 name,
849 THREAD);
850 } else {
851 // Thread gets assigned name "Thread-nnn" and null target
852 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
853 JavaCalls::call_special(&result,
854 thread_oop,
855 ik,
856 vmSymbols::object_initializer_name(),
857 vmSymbols::threadgroup_runnable_void_signature(),
858 thread_group,
859 Handle(),
860 THREAD);
861 }
862
863
864 if (daemon) {
865 java_lang_Thread::set_daemon(thread_oop());
866 }
867
868 if (HAS_PENDING_EXCEPTION) {
869 return;
870 }
871
872 Klass* group = vmClasses::ThreadGroup_klass();
873 Handle threadObj(THREAD, this->threadObj());
874
875 JavaCalls::call_special(&result,
876 thread_group,
877 group,
878 vmSymbols::add_method_name(),
879 vmSymbols::thread_void_signature(),
880 threadObj, // Arg 1
881 THREAD);
882 }
883
884 // ======= JavaThread ========
885
886 #if INCLUDE_JVMCI
887
888 jlong* JavaThread::_jvmci_old_thread_counters;
889
890 bool jvmci_counters_include(JavaThread* thread) {
891 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
892 }
893
894 void JavaThread::collect_counters(jlong* array, int length) {
895 assert(length == JVMCICounterSize, "wrong value");
896 for (int i = 0; i < length; i++) {
897 array[i] = _jvmci_old_thread_counters[i];
898 }
899 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *tp = jtiwh.next(); ) {
900 if (jvmci_counters_include(tp)) {
901 for (int i = 0; i < length; i++) {
902 array[i] += tp->_jvmci_counters[i];
903 }
904 }
905 }
906 }
907
908 // Attempt to enlarge the array for per thread counters.
909 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
910 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
911 if (new_counters == NULL) {
912 return NULL;
913 }
914 if (old_counters == NULL) {
915 old_counters = new_counters;
916 memset(old_counters, 0, sizeof(jlong) * new_size);
917 } else {
918 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
919 new_counters[i] = old_counters[i];
920 }
921 if (new_size > current_size) {
922 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
923 }
924 FREE_C_HEAP_ARRAY(jlong, old_counters);
925 }
926 return new_counters;
927 }
928
929 // Attempt to enlarge the array for per thread counters.
930 bool JavaThread::resize_counters(int current_size, int new_size) {
931 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
932 if (new_counters == NULL) {
933 return false;
934 } else {
935 _jvmci_counters = new_counters;
936 return true;
937 }
938 }
939
940 class VM_JVMCIResizeCounters : public VM_Operation {
941 private:
942 int _new_size;
943 bool _failed;
944
945 public:
946 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
947 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
948 bool allow_nested_vm_operations() const { return true; }
949 void doit() {
950 // Resize the old thread counters array
951 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
952 if (new_counters == NULL) {
953 _failed = true;
954 return;
955 } else {
956 JavaThread::_jvmci_old_thread_counters = new_counters;
957 }
958
959 // Now resize each threads array
960 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *tp = jtiwh.next(); ) {
961 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
962 _failed = true;
963 break;
964 }
965 }
966 if (!_failed) {
967 JVMCICounterSize = _new_size;
968 }
969 }
970
971 bool failed() { return _failed; }
972 };
973
974 bool JavaThread::resize_all_jvmci_counters(int new_size) {
975 VM_JVMCIResizeCounters op(new_size);
976 VMThread::execute(&op);
977 return !op.failed();
978 }
979
980 #endif // INCLUDE_JVMCI
981
982 #ifdef ASSERT
983 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
984 void JavaThread::check_possible_safepoint() {
985 if (_no_safepoint_count > 0) {
986 print_owned_locks();
987 assert(false, "Possible safepoint reached by thread that does not allow it");
988 }
989 #ifdef CHECK_UNHANDLED_OOPS
990 // Clear unhandled oops in JavaThreads so we get a crash right away.
991 clear_unhandled_oops();
992 #endif // CHECK_UNHANDLED_OOPS
993 }
994
995 void JavaThread::check_for_valid_safepoint_state() {
996 // Check NoSafepointVerifier, which is implied by locks taken that can be
997 // shared with the VM thread. This makes sure that no locks with allow_vm_block
998 // are held.
999 check_possible_safepoint();
1000
1001 if (thread_state() != _thread_in_vm) {
1002 fatal("LEAF method calling lock?");
1003 }
1004
1005 if (GCALotAtAllSafepoints) {
1006 // We could enter a safepoint here and thus have a gc
1007 InterfaceSupport::check_gc_alot();
1008 }
1009 }
1010 #endif // ASSERT
1011
1012 // A JavaThread is a normal Java thread
1013
1014 JavaThread::JavaThread() :
1015 // Initialize fields
1016
1017 _in_asgct(false),
1018 _on_thread_list(false),
1019 DEBUG_ONLY(_java_call_counter(0) COMMA)
1020 _entry_point(nullptr),
1021 _deopt_mark(nullptr),
1022 _deopt_nmethod(nullptr),
1023 _vframe_array_head(nullptr),
1024 _vframe_array_last(nullptr),
1025 _jvmti_deferred_updates(nullptr),
1026 _callee_target(nullptr),
1027 _vm_result(nullptr),
1028 _vm_result_2(nullptr),
1029
1030 _current_pending_monitor(NULL),
1031 _current_pending_monitor_is_from_java(true),
1032 _current_waiting_monitor(NULL),
1033 _Stalled(0),
1034
1035 _monitor_chunks(nullptr),
1036
1037 _suspend_flags(0),
1038 _async_exception_condition(_no_async_condition),
1039 _pending_async_exception(nullptr),
1040
1041 _thread_state(_thread_new),
1042 _saved_exception_pc(nullptr),
1043 #ifdef ASSERT
1044 _no_safepoint_count(0),
1045 _visited_for_critical_count(false),
1046 #endif
1047
1048 _terminated(_not_terminated),
1049 _in_deopt_handler(0),
1050 _doing_unsafe_access(false),
1051 _do_not_unlock_if_synchronized(false),
1052 _jni_attach_state(_not_attaching_via_jni),
1053 #if INCLUDE_JVMCI
1054 _pending_deoptimization(-1),
1055 _pending_monitorenter(false),
1056 _pending_transfer_to_interpreter(false),
1057 _in_retryable_allocation(false),
1058 _pending_failed_speculation(0),
1059 _jvmci{nullptr},
1060 _jvmci_counters(nullptr),
1061 _jvmci_reserved0(0),
1062 _jvmci_reserved1(0),
1063 _jvmci_reserved_oop0(nullptr),
1064 #endif // INCLUDE_JVMCI
1065
1066 _exception_oop(oop()),
1067 _exception_pc(0),
1068 _exception_handler_pc(0),
1069 _is_method_handle_return(0),
1070
1071 _jni_active_critical(0),
1072 _pending_jni_exception_check_fn(nullptr),
1073 _depth_first_number(0),
1074
1075 // JVMTI PopFrame support
1076 _popframe_condition(popframe_inactive),
1077 _frames_to_pop_failed_realloc(0),
1078
1079 _handshake(this),
1080
1081 _popframe_preserved_args(nullptr),
1082 _popframe_preserved_args_size(0),
1083
1084 _jvmti_thread_state(nullptr),
1085 _interp_only_mode(0),
1086 _should_post_on_exceptions_flag(JNI_FALSE),
1087 _thread_stat(new ThreadStatistics()),
1088
1089 _parker(),
1090 _cached_monitor_info(nullptr),
1091
1092 _class_to_be_initialized(nullptr),
1093
1094 _SleepEvent(ParkEvent::Allocate(this))
1095 {
1096 set_jni_functions(jni_functions());
1097
1098 #if INCLUDE_JVMCI
1099 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
1100 if (JVMCICounterSize > 0) {
1101 resize_counters(0, (int) JVMCICounterSize);
1102 }
1103 #endif // INCLUDE_JVMCI
1104
1105 // Setup safepoint state info for this thread
1106 ThreadSafepointState::create(this);
1107
1108 SafepointMechanism::initialize_header(this);
1109
1110 set_requires_cross_modify_fence(false);
1111
1112 pd_initialize();
1113 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
1114 }
1115
1116 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
1117 if (is_attaching_via_jni) {
1118 _jni_attach_state = _attaching_via_jni;
1119 }
1120 }
1121
1122
1123 // interrupt support
1124
1125 void JavaThread::interrupt() {
1126 // All callers should have 'this' thread protected by a
1127 // ThreadsListHandle so that it cannot terminate and deallocate
1128 // itself.
1129 debug_only(check_for_dangling_thread_pointer(this);)
1130
1131 // For Windows _interrupt_event
1132 osthread()->set_interrupted(true);
1133
1134 // For Thread.sleep
1135 _SleepEvent->unpark();
1136
1137 // For JSR166 LockSupport.park
1138 parker()->unpark();
1139
1140 // For ObjectMonitor and JvmtiRawMonitor
1141 _ParkEvent->unpark();
1142 }
1143
1144
1145 bool JavaThread::is_interrupted(bool clear_interrupted) {
1146 debug_only(check_for_dangling_thread_pointer(this);)
1147
1148 if (_threadObj.peek() == NULL) {
1149 // If there is no j.l.Thread then it is impossible to have
1150 // been interrupted. We can find NULL during VM initialization
1151 // or when a JNI thread is still in the process of attaching.
1152 // In such cases this must be the current thread.
1153 assert(this == Thread::current(), "invariant");
1154 return false;
1155 }
1156
1157 bool interrupted = java_lang_Thread::interrupted(threadObj());
1158
1159 // NOTE that since there is no "lock" around the interrupt and
1160 // is_interrupted operations, there is the possibility that the
1161 // interrupted flag will be "false" but that the
1162 // low-level events will be in the signaled state. This is
1163 // intentional. The effect of this is that Object.wait() and
1164 // LockSupport.park() will appear to have a spurious wakeup, which
1165 // is allowed and not harmful, and the possibility is so rare that
1166 // it is not worth the added complexity to add yet another lock.
1167 // For the sleep event an explicit reset is performed on entry
1168 // to JavaThread::sleep, so there is no early return. It has also been
1169 // recommended not to put the interrupted flag into the "event"
1170 // structure because it hides the issue.
1171 // Also, because there is no lock, we must only clear the interrupt
1172 // state if we are going to report that we were interrupted; otherwise
1173 // an interrupt that happens just after we read the field would be lost.
1174 if (interrupted && clear_interrupted) {
1175 assert(this == Thread::current(), "only the current thread can clear");
1176 java_lang_Thread::set_interrupted(threadObj(), false);
1177 osthread()->set_interrupted(false);
1178 }
1179
1180 return interrupted;
1181 }
1182
1183 void JavaThread::block_if_vm_exited() {
1184 if (_terminated == _vm_exited) {
1185 // _vm_exited is set at safepoint, and Threads_lock is never released
1186 // we will block here forever.
1187 // Here we can be doing a jump from a safe state to an unsafe state without
1188 // proper transition, but it happens after the final safepoint has begun.
1189 set_thread_state(_thread_in_vm);
1190 Threads_lock->lock();
1191 ShouldNotReachHere();
1192 }
1193 }
1194
1195 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
1196 _jni_attach_state = _not_attaching_via_jni;
1197 set_entry_point(entry_point);
1198 // Create the native thread itself.
1199 // %note runtime_23
1200 os::ThreadType thr_type = os::java_thread;
1201 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
1202 os::java_thread;
1203 os::create_thread(this, thr_type, stack_sz);
1204 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1205 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1206 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1207 // the exception consists of creating the exception object & initializing it, initialization
1208 // will leave the VM via a JavaCall and then all locks must be unlocked).
1209 //
1210 // The thread is still suspended when we reach here. Thread must be explicit started
1211 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1212 // by calling Threads:add. The reason why this is not done here, is because the thread
1213 // object must be fully initialized (take a look at JVM_Start)
1214 }
1215
1216 JavaThread::~JavaThread() {
1217
1218 // Ask ServiceThread to release the threadObj OopHandle
1219 ServiceThread::add_oop_handle_release(_threadObj);
1220
1221 // Return the sleep event to the free list
1222 ParkEvent::Release(_SleepEvent);
1223 _SleepEvent = NULL;
1224
1225 // Free any remaining previous UnrollBlock
1226 vframeArray* old_array = vframe_array_last();
1227
1228 if (old_array != NULL) {
1229 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1230 old_array->set_unroll_block(NULL);
1231 delete old_info;
1232 delete old_array;
1233 }
1234
1235 JvmtiDeferredUpdates* updates = deferred_updates();
1236 if (updates != NULL) {
1237 // This can only happen if thread is destroyed before deoptimization occurs.
1238 assert(updates->count() > 0, "Updates holder not deleted");
1239 // free deferred updates.
1240 delete updates;
1241 set_deferred_updates(NULL);
1242 }
1243
1244 // All Java related clean up happens in exit
1245 ThreadSafepointState::destroy(this);
1246 if (_thread_stat != NULL) delete _thread_stat;
1247
1248 #if INCLUDE_JVMCI
1249 if (JVMCICounterSize > 0) {
1250 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
1251 }
1252 #endif // INCLUDE_JVMCI
1253 }
1254
1255
1256 // First JavaThread specific code executed by a new Java thread.
1257 void JavaThread::pre_run() {
1258 // empty - see comments in run()
1259 }
1260
1261 // The main routine called by a new Java thread. This isn't overridden
1262 // by subclasses, instead different subclasses define a different "entry_point"
1263 // which defines the actual logic for that kind of thread.
1264 void JavaThread::run() {
1265 // initialize thread-local alloc buffer related fields
1266 initialize_tlab();
1267
1268 _stack_overflow_state.create_stack_guard_pages();
1269
1270 cache_global_variables();
1271
1272 // Thread is now sufficiently initialized to be handled by the safepoint code as being
1273 // in the VM. Change thread state from _thread_new to _thread_in_vm
1274 ThreadStateTransition::transition(this, _thread_new, _thread_in_vm);
1275 // Before a thread is on the threads list it is always safe, so after leaving the
1276 // _thread_new we should emit a instruction barrier. The distance to modified code
1277 // from here is probably far enough, but this is consistent and safe.
1278 OrderAccess::cross_modify_fence();
1279
1280 assert(JavaThread::current() == this, "sanity check");
1281 assert(!Thread::current()->owns_locks(), "sanity check");
1282
1283 DTRACE_THREAD_PROBE(start, this);
1284
1285 // This operation might block. We call that after all safepoint checks for a new thread has
1286 // been completed.
1287 set_active_handles(JNIHandleBlock::allocate_block());
1288
1289 if (JvmtiExport::should_post_thread_life()) {
1290 JvmtiExport::post_thread_start(this);
1291
1292 }
1293
1294 // We call another function to do the rest so we are sure that the stack addresses used
1295 // from there will be lower than the stack base just computed.
1296 thread_main_inner();
1297 }
1298
1299 void JavaThread::thread_main_inner() {
1300 assert(JavaThread::current() == this, "sanity check");
1301 assert(_threadObj.peek() != NULL, "just checking");
1302
1303 // Execute thread entry point unless this thread has a pending exception
1304 // or has been stopped before starting.
1305 // Note: Due to JVM_StopThread we can have pending exceptions already!
1306 if (!this->has_pending_exception() &&
1307 !java_lang_Thread::is_stillborn(this->threadObj())) {
1308 {
1309 ResourceMark rm(this);
1310 this->set_native_thread_name(this->get_thread_name());
1311 }
1312 HandleMark hm(this);
1313 this->entry_point()(this, this);
1314 }
1315
1316 DTRACE_THREAD_PROBE(stop, this);
1317
1318 // Cleanup is handled in post_run()
1319 }
1320
1321 // Shared teardown for all JavaThreads
1322 void JavaThread::post_run() {
1323 this->exit(false);
1324 this->unregister_thread_stack_with_NMT();
1325 // Defer deletion to here to ensure 'this' is still referenceable in call_run
1326 // for any shared tear-down.
1327 this->smr_delete();
1328 }
1329
1330 static void ensure_join(JavaThread* thread) {
1331 // We do not need to grab the Threads_lock, since we are operating on ourself.
1332 Handle threadObj(thread, thread->threadObj());
1333 assert(threadObj.not_null(), "java thread object must exist");
1334 ObjectLocker lock(threadObj, thread);
1335 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1336 thread->clear_pending_exception();
1337 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1338 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
1339 // Clear the native thread instance - this makes isAlive return false and allows the join()
1340 // to complete once we've done the notify_all below
1341 java_lang_Thread::set_thread(threadObj(), NULL);
1342 lock.notify_all(thread);
1343 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1344 thread->clear_pending_exception();
1345 }
1346
1347 static bool is_daemon(oop threadObj) {
1348 return (threadObj != NULL && java_lang_Thread::is_daemon(threadObj));
1349 }
1350
1351 // For any new cleanup additions, please check to see if they need to be applied to
1352 // cleanup_failed_attach_current_thread as well.
1353 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1354 assert(this == JavaThread::current(), "thread consistency check");
1355
1356 elapsedTimer _timer_exit_phase1;
1357 elapsedTimer _timer_exit_phase2;
1358 elapsedTimer _timer_exit_phase3;
1359 elapsedTimer _timer_exit_phase4;
1360
1361 if (log_is_enabled(Debug, os, thread, timer)) {
1362 _timer_exit_phase1.start();
1363 }
1364
1365 HandleMark hm(this);
1366 Handle uncaught_exception(this, this->pending_exception());
1367 this->clear_pending_exception();
1368 Handle threadObj(this, this->threadObj());
1369 assert(threadObj.not_null(), "Java thread object should be created");
1370
1371 if (!destroy_vm) {
1372 if (uncaught_exception.not_null()) {
1373 EXCEPTION_MARK;
1374 // Call method Thread.dispatchUncaughtException().
1375 Klass* thread_klass = vmClasses::Thread_klass();
1376 JavaValue result(T_VOID);
1377 JavaCalls::call_virtual(&result,
1378 threadObj, thread_klass,
1379 vmSymbols::dispatchUncaughtException_name(),
1380 vmSymbols::throwable_void_signature(),
1381 uncaught_exception,
1382 THREAD);
1383 if (HAS_PENDING_EXCEPTION) {
1384 ResourceMark rm(this);
1385 jio_fprintf(defaultStream::error_stream(),
1386 "\nException: %s thrown from the UncaughtExceptionHandler"
1387 " in thread \"%s\"\n",
1388 pending_exception()->klass()->external_name(),
1389 get_thread_name());
1390 CLEAR_PENDING_EXCEPTION;
1391 }
1392 }
1393
1394 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1395 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1396 // is deprecated anyhow.
1397 if (!is_Compiler_thread()) {
1398 int count = 3;
1399 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1400 EXCEPTION_MARK;
1401 JavaValue result(T_VOID);
1402 Klass* thread_klass = vmClasses::Thread_klass();
1403 JavaCalls::call_virtual(&result,
1404 threadObj, thread_klass,
1405 vmSymbols::exit_method_name(),
1406 vmSymbols::void_method_signature(),
1407 THREAD);
1408 CLEAR_PENDING_EXCEPTION;
1409 }
1410 }
1411 // notify JVMTI
1412 if (JvmtiExport::should_post_thread_life()) {
1413 JvmtiExport::post_thread_end(this);
1414 }
1415
1416 // The careful dance between thread suspension and exit is handled here.
1417 // Since we are in thread_in_vm state and suspension is done with handshakes,
1418 // we can just put in the exiting state and it will be correctly handled.
1419 set_terminated(_thread_exiting);
1420
1421 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
1422 } else {
1423 assert(!is_terminated() && !is_exiting(), "must not be exiting");
1424 // before_exit() has already posted JVMTI THREAD_END events
1425 }
1426
1427 if (log_is_enabled(Debug, os, thread, timer)) {
1428 _timer_exit_phase1.stop();
1429 _timer_exit_phase2.start();
1430 }
1431
1432 // Capture daemon status before the thread is marked as terminated.
1433 bool daemon = is_daemon(threadObj());
1434
1435 // Notify waiters on thread object. This has to be done after exit() is called
1436 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1437 // group should have the destroyed bit set before waiters are notified).
1438 ensure_join(this);
1439 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1440
1441 if (log_is_enabled(Debug, os, thread, timer)) {
1442 _timer_exit_phase2.stop();
1443 _timer_exit_phase3.start();
1444 }
1445 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1446 // held by this thread must be released. The spec does not distinguish
1447 // between JNI-acquired and regular Java monitors. We can only see
1448 // regular Java monitors here if monitor enter-exit matching is broken.
1449 //
1450 // ensure_join() ignores IllegalThreadStateExceptions, and so does
1451 // ObjectSynchronizer::release_monitors_owned_by_thread().
1452 if (exit_type == jni_detach) {
1453 // Sanity check even though JNI DetachCurrentThread() would have
1454 // returned JNI_ERR if there was a Java frame. JavaThread exit
1455 // should be done executing Java code by the time we get here.
1456 assert(!this->has_last_Java_frame(),
1457 "should not have a Java frame when detaching or exiting");
1458 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1459 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1460 }
1461
1462 // These things needs to be done while we are still a Java Thread. Make sure that thread
1463 // is in a consistent state, in case GC happens
1464 JFR_ONLY(Jfr::on_thread_exit(this);)
1465
1466 if (active_handles() != NULL) {
1467 JNIHandleBlock* block = active_handles();
1468 set_active_handles(NULL);
1469 JNIHandleBlock::release_block(block);
1470 }
1471
1472 if (free_handle_block() != NULL) {
1473 JNIHandleBlock* block = free_handle_block();
1474 set_free_handle_block(NULL);
1475 JNIHandleBlock::release_block(block);
1476 }
1477
1478 // These have to be removed while this is still a valid thread.
1479 _stack_overflow_state.remove_stack_guard_pages();
1480
1481 if (UseTLAB) {
1482 tlab().retire();
1483 }
1484
1485 if (JvmtiEnv::environments_might_exist()) {
1486 JvmtiExport::cleanup_thread(this);
1487 }
1488
1489 // We need to cache the thread name for logging purposes below as once
1490 // we have called on_thread_detach this thread must not access any oops.
1491 char* thread_name = NULL;
1492 if (log_is_enabled(Debug, os, thread, timer)) {
1493 ResourceMark rm(this);
1494 thread_name = os::strdup(get_thread_name());
1495 }
1496
1497 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
1498 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
1499 os::current_thread_id());
1500
1501 if (log_is_enabled(Debug, os, thread, timer)) {
1502 _timer_exit_phase3.stop();
1503 _timer_exit_phase4.start();
1504 }
1505
1506 #if INCLUDE_JVMCI
1507 if (JVMCICounterSize > 0) {
1508 if (jvmci_counters_include(this)) {
1509 for (int i = 0; i < JVMCICounterSize; i++) {
1510 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
1511 }
1512 }
1513 }
1514 #endif // INCLUDE_JVMCI
1515
1516 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1517 Threads::remove(this, daemon);
1518
1519 if (log_is_enabled(Debug, os, thread, timer)) {
1520 _timer_exit_phase4.stop();
1521 log_debug(os, thread, timer)("name='%s'"
1522 ", exit-phase1=" JLONG_FORMAT
1523 ", exit-phase2=" JLONG_FORMAT
1524 ", exit-phase3=" JLONG_FORMAT
1525 ", exit-phase4=" JLONG_FORMAT,
1526 thread_name,
1527 _timer_exit_phase1.milliseconds(),
1528 _timer_exit_phase2.milliseconds(),
1529 _timer_exit_phase3.milliseconds(),
1530 _timer_exit_phase4.milliseconds());
1531 os::free(thread_name);
1532 }
1533 }
1534
1535 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
1536 if (active_handles() != NULL) {
1537 JNIHandleBlock* block = active_handles();
1538 set_active_handles(NULL);
1539 JNIHandleBlock::release_block(block);
1540 }
1541
1542 if (free_handle_block() != NULL) {
1543 JNIHandleBlock* block = free_handle_block();
1544 set_free_handle_block(NULL);
1545 JNIHandleBlock::release_block(block);
1546 }
1547
1548 // These have to be removed while this is still a valid thread.
1549 _stack_overflow_state.remove_stack_guard_pages();
1550
1551 if (UseTLAB) {
1552 tlab().retire();
1553 }
1554
1555 Threads::remove(this, is_daemon);
1556 this->smr_delete();
1557 }
1558
1559 JavaThread* JavaThread::active() {
1560 Thread* thread = Thread::current();
1561 if (thread->is_Java_thread()) {
1562 return thread->as_Java_thread();
1563 } else {
1564 assert(thread->is_VM_thread(), "this must be a vm thread");
1565 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1566 JavaThread *ret = op == NULL ? NULL : op->calling_thread()->as_Java_thread();
1567 return ret;
1568 }
1569 }
1570
1571 bool JavaThread::is_lock_owned(address adr) const {
1572 if (Thread::is_lock_owned(adr)) return true;
1573
1574 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1575 if (chunk->contains(adr)) return true;
1576 }
1577
1578 return false;
1579 }
1580
1581 oop JavaThread::exception_oop() const {
1582 return Atomic::load(&_exception_oop);
1583 }
1584
1585 void JavaThread::set_exception_oop(oop o) {
1586 Atomic::store(&_exception_oop, o);
1587 }
1588
1589 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1590 chunk->set_next(monitor_chunks());
1591 set_monitor_chunks(chunk);
1592 }
1593
1594 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1595 guarantee(monitor_chunks() != NULL, "must be non empty");
1596 if (monitor_chunks() == chunk) {
1597 set_monitor_chunks(chunk->next());
1598 } else {
1599 MonitorChunk* prev = monitor_chunks();
1600 while (prev->next() != chunk) prev = prev->next();
1601 prev->set_next(chunk->next());
1602 }
1603 }
1604
1605
1606 // Asynchronous exceptions support
1607 //
1608 // Note: this function shouldn't block if it's called in
1609 // _thread_in_native_trans state (such as from
1610 // check_special_condition_for_native_trans()).
1611 void JavaThread::check_and_handle_async_exceptions() {
1612 if (has_last_Java_frame() && has_async_exception_condition()) {
1613 // If we are at a polling page safepoint (not a poll return)
1614 // then we must defer async exception because live registers
1615 // will be clobbered by the exception path. Poll return is
1616 // ok because the call we a returning from already collides
1617 // with exception handling registers and so there is no issue.
1618 // (The exception handling path kills call result registers but
1619 // this is ok since the exception kills the result anyway).
1620
1621 if (is_at_poll_safepoint()) {
1622 // if the code we are returning to has deoptimized we must defer
1623 // the exception otherwise live registers get clobbered on the
1624 // exception path before deoptimization is able to retrieve them.
1625 //
1626 RegisterMap map(this, false);
1627 frame caller_fr = last_frame().sender(&map);
1628 assert(caller_fr.is_compiled_frame(), "what?");
1629 if (caller_fr.is_deoptimized_frame()) {
1630 log_info(exceptions)("deferred async exception at compiled safepoint");
1631 return;
1632 }
1633 }
1634 }
1635
1636 AsyncExceptionCondition condition = clear_async_exception_condition();
1637 if (condition == _no_async_condition) {
1638 // Conditions have changed since has_special_runtime_exit_condition()
1639 // was called:
1640 // - if we were here only because of an external suspend request,
1641 // then that was taken care of above (or cancelled) so we are done
1642 // - if we were here because of another async request, then it has
1643 // been cleared between the has_special_runtime_exit_condition()
1644 // and now so again we are done
1645 return;
1646 }
1647
1648 // Check for pending async. exception
1649 if (_pending_async_exception != NULL) {
1650 // Only overwrite an already pending exception, if it is not a threadDeath.
1651 if (!has_pending_exception() || !pending_exception()->is_a(vmClasses::ThreadDeath_klass())) {
1652
1653 // We cannot call Exceptions::_throw(...) here because we cannot block
1654 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1655
1656 LogTarget(Info, exceptions) lt;
1657 if (lt.is_enabled()) {
1658 ResourceMark rm;
1659 LogStream ls(lt);
1660 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1661 if (has_last_Java_frame()) {
1662 frame f = last_frame();
1663 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1664 }
1665 ls.print_cr(" of type: %s", _pending_async_exception->klass()->external_name());
1666 }
1667 _pending_async_exception = NULL;
1668 // Clear condition from _suspend_flags since we have finished processing it.
1669 clear_suspend_flag(_has_async_exception);
1670 }
1671 }
1672
1673 if (condition == _async_unsafe_access_error && !has_pending_exception()) {
1674 // We may be at method entry which requires we save the do-not-unlock flag.
1675 UnlockFlagSaver fs(this);
1676 switch (thread_state()) {
1677 case _thread_in_vm: {
1678 JavaThread* THREAD = this;
1679 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in an unsafe memory access operation");
1680 return;
1681 }
1682 case _thread_in_native: {
1683 ThreadInVMfromNative tiv(this);
1684 JavaThread* THREAD = this;
1685 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in an unsafe memory access operation");
1686 return;
1687 }
1688 case _thread_in_Java: {
1689 ThreadInVMfromJava tiv(this);
1690 JavaThread* THREAD = this;
1691 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1692 return;
1693 }
1694 default:
1695 ShouldNotReachHere();
1696 }
1697 }
1698
1699 assert(has_pending_exception(), "must have handled the async condition if no exception");
1700 }
1701
1702 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1703
1704 if (is_obj_deopt_suspend()) {
1705 frame_anchor()->make_walkable();
1706 wait_for_object_deoptimization();
1707 }
1708
1709 // We might be here for reasons in addition to the self-suspend request
1710 // so check for other async requests.
1711 if (check_asyncs) {
1712 check_and_handle_async_exceptions();
1713 }
1714
1715 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1716 }
1717
1718 class InstallAsyncExceptionClosure : public HandshakeClosure {
1719 Handle _throwable; // The Throwable thrown at the target Thread
1720 public:
1721 InstallAsyncExceptionClosure(Handle throwable) : HandshakeClosure("InstallAsyncException"), _throwable(throwable) {}
1722
1723 void do_thread(Thread* thr) {
1724 JavaThread* target = thr->as_Java_thread();
1725 // Note that this now allows multiple ThreadDeath exceptions to be
1726 // thrown at a thread.
1727 // The target thread has run and has not exited yet.
1728 target->send_thread_stop(_throwable());
1729 }
1730 };
1731
1732 void JavaThread::send_async_exception(oop java_thread, oop java_throwable) {
1733 Handle throwable(Thread::current(), java_throwable);
1734 JavaThread* target = java_lang_Thread::thread(java_thread);
1735 InstallAsyncExceptionClosure vm_stop(throwable);
1736 Handshake::execute(&vm_stop, target);
1737 }
1738
1739 void JavaThread::send_thread_stop(oop java_throwable) {
1740 ResourceMark rm;
1741 assert(is_handshake_safe_for(Thread::current()),
1742 "should be self or handshakee");
1743
1744 // Do not throw asynchronous exceptions against the compiler thread
1745 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1746 if (!can_call_java()) return;
1747
1748 {
1749 // Actually throw the Throwable against the target Thread - however
1750 // only if there is no thread death exception installed already.
1751 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(vmClasses::ThreadDeath_klass())) {
1752 // If the topmost frame is a runtime stub, then we are calling into
1753 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1754 // must deoptimize the caller before continuing, as the compiled exception handler table
1755 // may not be valid
1756 if (has_last_Java_frame()) {
1757 frame f = last_frame();
1758 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1759 RegisterMap reg_map(this, false);
1760 frame compiled_frame = f.sender(®_map);
1761 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1762 Deoptimization::deoptimize(this, compiled_frame);
1763 }
1764 }
1765 }
1766
1767 // Set async. pending exception in thread.
1768 set_pending_async_exception(java_throwable);
1769
1770 if (log_is_enabled(Info, exceptions)) {
1771 ResourceMark rm;
1772 log_info(exceptions)("Pending Async. exception installed of type: %s",
1773 InstanceKlass::cast(_pending_async_exception->klass())->external_name());
1774 }
1775 // for AbortVMOnException flag
1776 Exceptions::debug_check_abort(_pending_async_exception->klass()->external_name());
1777 }
1778 }
1779
1780
1781 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1782 java_lang_Thread::set_interrupted(threadObj(), true);
1783 this->interrupt();
1784 }
1785
1786
1787 // External suspension mechanism.
1788 //
1789 // Guarantees on return (for a valid target thread):
1790 // - Target thread will not execute any new bytecode.
1791 // - Target thread will not enter any new monitors.
1792 //
1793 bool JavaThread::java_suspend() {
1794 ThreadsListHandle tlh;
1795 if (!tlh.includes(this)) {
1796 log_trace(thread, suspend)("JavaThread:" INTPTR_FORMAT " not on ThreadsList, no suspension", p2i(this));
1797 return false;
1798 }
1799 return this->handshake_state()->suspend();
1800 }
1801
1802 bool JavaThread::java_resume() {
1803 ThreadsListHandle tlh;
1804 if (!tlh.includes(this)) {
1805 log_trace(thread, suspend)("JavaThread:" INTPTR_FORMAT " not on ThreadsList, nothing to resume", p2i(this));
1806 return false;
1807 }
1808 return this->handshake_state()->resume();
1809 }
1810
1811 // Wait for another thread to perform object reallocation and relocking on behalf of
1812 // this thread.
1813 // Raw thread state transition to _thread_blocked and back again to the original
1814 // state before returning are performed. The current thread is required to
1815 // change to _thread_blocked in order to be seen to be safepoint/handshake safe
1816 // whilst suspended and only after becoming handshake safe, the other thread can
1817 // complete the handshake used to synchronize with this thread and then perform
1818 // the reallocation and relocking. We cannot use the thread state transition
1819 // helpers because we arrive here in various states and also because the helpers
1820 // indirectly call this method. After leaving _thread_blocked we have to check
1821 // for safepoint/handshake, except if _thread_in_native. The thread is safe
1822 // without blocking then. Allowed states are enumerated in
1823 // SafepointSynchronize::block(). See also EscapeBarrier::sync_and_suspend_*()
1824
1825 void JavaThread::wait_for_object_deoptimization() {
1826 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1827 assert(this == Thread::current(), "invariant");
1828 JavaThreadState state = thread_state();
1829
1830 bool spin_wait = os::is_MP();
1831 do {
1832 set_thread_state(_thread_blocked);
1833 // Wait for object deoptimization if requested.
1834 if (spin_wait) {
1835 // A single deoptimization is typically very short. Microbenchmarks
1836 // showed 5% better performance when spinning.
1837 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1838 SpinYield spin(spin_limit);
1839 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1840 spin.wait();
1841 }
1842 // Spin just once
1843 spin_wait = false;
1844 } else {
1845 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1846 if (is_obj_deopt_suspend()) {
1847 ml.wait();
1848 }
1849 }
1850 // The current thread could have been suspended again. We have to check for
1851 // suspend after restoring the saved state. Without this the current thread
1852 // might return to _thread_in_Java and execute bytecode.
1853 set_thread_state_fence(state);
1854
1855 if (state != _thread_in_native) {
1856 SafepointMechanism::process_if_requested(this);
1857 }
1858 // A handshake for obj. deoptimization suspend could have been processed so
1859 // we must check after processing.
1860 } while (is_obj_deopt_suspend());
1861 }
1862
1863 #ifdef ASSERT
1864 // Verify the JavaThread has not yet been published in the Threads::list, and
1865 // hence doesn't need protection from concurrent access at this stage.
1866 void JavaThread::verify_not_published() {
1867 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1868 // since an unpublished JavaThread doesn't participate in the
1869 // Thread-SMR protocol for keeping a ThreadsList alive.
1870 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1871 }
1872 #endif
1873
1874 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1875 // pending, when _suspend_flags is non-zero or when we need to process a stack
1876 // watermark. Also check for pending async exceptions (except unsafe access error).
1877 // Note only the native==>Java barriers can call this function when thread state
1878 // is _thread_in_native_trans.
1879 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1880 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1881 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1882
1883 // Enable WXWrite: called directly from interpreter native wrapper.
1884 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1885
1886 SafepointMechanism::process_if_requested_with_exit_check(thread, false /* check asyncs */);
1887
1888 // After returning from native, it could be that the stack frames are not
1889 // yet safe to use. We catch such situations in the subsequent stack watermark
1890 // barrier, which will trap unsafe stack frames.
1891 StackWatermarkSet::before_unwind(thread);
1892
1893 if (thread->has_async_exception_condition(false /* check unsafe access error */)) {
1894 // We are in _thread_in_native_trans state, don't handle unsafe
1895 // access error since that may block.
1896 thread->check_and_handle_async_exceptions();
1897 }
1898 }
1899
1900 #ifndef PRODUCT
1901 // Deoptimization
1902 // Function for testing deoptimization
1903 void JavaThread::deoptimize() {
1904 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1905 bool deopt = false; // Dump stack only if a deopt actually happens.
1906 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1907 // Iterate over all frames in the thread and deoptimize
1908 for (; !fst.is_done(); fst.next()) {
1909 if (fst.current()->can_be_deoptimized()) {
1910
1911 if (only_at) {
1912 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1913 // consists of comma or carriage return separated numbers so
1914 // search for the current bci in that string.
1915 address pc = fst.current()->pc();
1916 nmethod* nm = (nmethod*) fst.current()->cb();
1917 ScopeDesc* sd = nm->scope_desc_at(pc);
1918 char buffer[8];
1919 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1920 size_t len = strlen(buffer);
1921 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1922 while (found != NULL) {
1923 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1924 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1925 // Check that the bci found is bracketed by terminators.
1926 break;
1927 }
1928 found = strstr(found + 1, buffer);
1929 }
1930 if (!found) {
1931 continue;
1932 }
1933 }
1934
1935 if (DebugDeoptimization && !deopt) {
1936 deopt = true; // One-time only print before deopt
1937 tty->print_cr("[BEFORE Deoptimization]");
1938 trace_frames();
1939 trace_stack();
1940 }
1941 Deoptimization::deoptimize(this, *fst.current());
1942 }
1943 }
1944
1945 if (DebugDeoptimization && deopt) {
1946 tty->print_cr("[AFTER Deoptimization]");
1947 trace_frames();
1948 }
1949 }
1950
1951
1952 // Make zombies
1953 void JavaThread::make_zombies() {
1954 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1955 if (fst.current()->can_be_deoptimized()) {
1956 // it is a Java nmethod
1957 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1958 nm->make_not_entrant();
1959 }
1960 }
1961 }
1962 #endif // PRODUCT
1963
1964
1965 void JavaThread::deoptimize_marked_methods() {
1966 if (!has_last_Java_frame()) return;
1967 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1968 for (; !fst.is_done(); fst.next()) {
1969 if (fst.current()->should_be_deoptimized()) {
1970 Deoptimization::deoptimize(this, *fst.current());
1971 }
1972 }
1973 }
1974
1975 #ifdef ASSERT
1976 void JavaThread::verify_frame_info() {
1977 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1978 (has_last_Java_frame() && java_call_counter() > 0),
1979 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1980 has_last_Java_frame() ? "true" : "false", java_call_counter());
1981 }
1982 #endif
1983
1984 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1985 // Verify that the deferred card marks have been flushed.
1986 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1987
1988 // Traverse the GCHandles
1989 Thread::oops_do_no_frames(f, cf);
1990
1991 DEBUG_ONLY(verify_frame_info();)
1992
1993 if (has_last_Java_frame()) {
1994 // Traverse the monitor chunks
1995 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1996 chunk->oops_do(f);
1997 }
1998 }
1999
2000 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2001 // If we have deferred set_locals there might be oops waiting to be
2002 // written
2003 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
2004 if (list != NULL) {
2005 for (int i = 0; i < list->length(); i++) {
2006 list->at(i)->oops_do(f);
2007 }
2008 }
2009
2010 // Traverse instance variables at the end since the GC may be moving things
2011 // around using this function
2012 f->do_oop((oop*) &_vm_result);
2013 f->do_oop((oop*) &_exception_oop);
2014 f->do_oop((oop*) &_pending_async_exception);
2015 #if INCLUDE_JVMCI
2016 f->do_oop((oop*) &_jvmci_reserved_oop0);
2017 #endif
2018
2019 if (jvmti_thread_state() != NULL) {
2020 jvmti_thread_state()->oops_do(f, cf);
2021 }
2022 }
2023
2024 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
2025 if (!has_last_Java_frame()) {
2026 return;
2027 }
2028 // Finish any pending lazy GC activity for the frames
2029 StackWatermarkSet::finish_processing(this, NULL /* context */, StackWatermarkKind::gc);
2030 // Traverse the execution stack
2031 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
2032 fst.current()->oops_do(f, cf, fst.register_map());
2033 }
2034 }
2035
2036 #ifdef ASSERT
2037 void JavaThread::verify_states_for_handshake() {
2038 // This checks that the thread has a correct frame state during a handshake.
2039 verify_frame_info();
2040 }
2041 #endif
2042
2043 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2044 DEBUG_ONLY(verify_frame_info();)
2045
2046 if (has_last_Java_frame()) {
2047 // Traverse the execution stack
2048 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2049 fst.current()->nmethods_do(cf);
2050 }
2051 }
2052
2053 if (jvmti_thread_state() != NULL) {
2054 jvmti_thread_state()->nmethods_do(cf);
2055 }
2056 }
2057
2058 void JavaThread::metadata_do(MetadataClosure* f) {
2059 if (has_last_Java_frame()) {
2060 // Traverse the execution stack to call f() on the methods in the stack
2061 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2062 fst.current()->metadata_do(f);
2063 }
2064 } else if (is_Compiler_thread()) {
2065 // need to walk ciMetadata in current compile tasks to keep alive.
2066 CompilerThread* ct = (CompilerThread*)this;
2067 if (ct->env() != NULL) {
2068 ct->env()->metadata_do(f);
2069 }
2070 CompileTask* task = ct->task();
2071 if (task != NULL) {
2072 task->metadata_do(f);
2073 }
2074 }
2075 }
2076
2077 // Printing
2078 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2079 switch (_thread_state) {
2080 case _thread_uninitialized: return "_thread_uninitialized";
2081 case _thread_new: return "_thread_new";
2082 case _thread_new_trans: return "_thread_new_trans";
2083 case _thread_in_native: return "_thread_in_native";
2084 case _thread_in_native_trans: return "_thread_in_native_trans";
2085 case _thread_in_vm: return "_thread_in_vm";
2086 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2087 case _thread_in_Java: return "_thread_in_Java";
2088 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2089 case _thread_blocked: return "_thread_blocked";
2090 case _thread_blocked_trans: return "_thread_blocked_trans";
2091 default: return "unknown thread state";
2092 }
2093 }
2094
2095 #ifndef PRODUCT
2096 void JavaThread::print_thread_state_on(outputStream *st) const {
2097 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2098 };
2099 #endif // PRODUCT
2100
2101 // Called by Threads::print() for VM_PrintThreads operation
2102 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
2103 st->print_raw("\"");
2104 st->print_raw(get_thread_name());
2105 st->print_raw("\" ");
2106 oop thread_oop = threadObj();
2107 if (thread_oop != NULL) {
2108 st->print("#" INT64_FORMAT " ", (int64_t)java_lang_Thread::thread_id(thread_oop));
2109 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2110 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2111 }
2112 Thread::print_on(st, print_extended_info);
2113 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2114 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2115 if (thread_oop != NULL) {
2116 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2117 }
2118 #ifndef PRODUCT
2119 _safepoint_state->print_on(st);
2120 #endif // PRODUCT
2121 if (is_Compiler_thread()) {
2122 CompileTask *task = ((CompilerThread*)this)->task();
2123 if (task != NULL) {
2124 st->print(" Compiling: ");
2125 task->print(st, NULL, true, false);
2126 } else {
2127 st->print(" No compile task");
2128 }
2129 st->cr();
2130 }
2131 }
2132
2133 void JavaThread::print() const { print_on(tty); }
2134
2135 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
2136 st->print("%s", get_thread_name_string(buf, buflen));
2137 }
2138
2139 // Called by fatal error handler. The difference between this and
2140 // JavaThread::print() is that we can't grab lock or allocate memory.
2141 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2142 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2143 oop thread_obj = threadObj();
2144 if (thread_obj != NULL) {
2145 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2146 }
2147 st->print(" [");
2148 st->print("%s", _get_thread_state_name(_thread_state));
2149 if (osthread()) {
2150 st->print(", id=%d", osthread()->thread_id());
2151 }
2152 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2153 p2i(stack_end()), p2i(stack_base()));
2154 st->print("]");
2155
2156 ThreadsSMRSupport::print_info_on(this, st);
2157 return;
2158 }
2159
2160
2161 // Verification
2162
2163 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2164 // ignore if there is no stack
2165 if (!has_last_Java_frame()) return;
2166 // traverse the stack frames. Starts from top frame.
2167 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2168 frame* fr = fst.current();
2169 f(fr, fst.register_map());
2170 }
2171 }
2172
2173 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2174
2175 void JavaThread::verify() {
2176 // Verify oops in the thread.
2177 oops_do(&VerifyOopClosure::verify_oop, NULL);
2178
2179 // Verify the stack frames.
2180 frames_do(frame_verify);
2181 }
2182
2183 // CR 6300358 (sub-CR 2137150)
2184 // Most callers of this method assume that it can't return NULL but a
2185 // thread may not have a name whilst it is in the process of attaching to
2186 // the VM - see CR 6412693, and there are places where a JavaThread can be
2187 // seen prior to having its threadObj set (e.g., JNI attaching threads and
2188 // if vm exit occurs during initialization). These cases can all be accounted
2189 // for such that this method never returns NULL.
2190 const char* JavaThread::get_thread_name() const {
2191 if (Thread::is_JavaThread_protected(this)) {
2192 // The target JavaThread is protected so get_thread_name_string() is safe:
2193 return get_thread_name_string();
2194 }
2195
2196 // The target JavaThread is not protected so we return the default:
2197 return Thread::name();
2198 }
2199
2200 // Returns a non-NULL representation of this thread's name, or a suitable
2201 // descriptive string if there is no set name.
2202 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2203 const char* name_str;
2204 oop thread_obj = threadObj();
2205 if (thread_obj != NULL) {
2206 oop name = java_lang_Thread::name(thread_obj);
2207 if (name != NULL) {
2208 if (buf == NULL) {
2209 name_str = java_lang_String::as_utf8_string(name);
2210 } else {
2211 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
2212 }
2213 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2214 name_str = "<no-name - thread is attaching>";
2215 } else {
2216 name_str = Thread::name();
2217 }
2218 } else {
2219 name_str = Thread::name();
2220 }
2221 assert(name_str != NULL, "unexpected NULL thread name");
2222 return name_str;
2223 }
2224
2225 // Helper to extract the name from the thread oop for logging.
2226 const char* JavaThread::name_for(oop thread_obj) {
2227 assert(thread_obj != NULL, "precondition");
2228 oop name = java_lang_Thread::name(thread_obj);
2229 const char* name_str;
2230 if (name != NULL) {
2231 name_str = java_lang_String::as_utf8_string(name);
2232 } else {
2233 name_str = "<un-named>";
2234 }
2235 return name_str;
2236 }
2237
2238 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2239
2240 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2241 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
2242 // Link Java Thread object <-> C++ Thread
2243
2244 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2245 // and put it into a new Handle. The Handle "thread_oop" can then
2246 // be used to pass the C++ thread object to other methods.
2247
2248 // Set the Java level thread object (jthread) field of the
2249 // new thread (a JavaThread *) to C++ thread object using the
2250 // "thread_oop" handle.
2251
2252 // Set the thread field (a JavaThread *) of the
2253 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2254
2255 Handle thread_oop(Thread::current(),
2256 JNIHandles::resolve_non_null(jni_thread));
2257 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
2258 "must be initialized");
2259 set_threadObj(thread_oop());
2260 java_lang_Thread::set_thread(thread_oop(), this);
2261
2262 if (prio == NoPriority) {
2263 prio = java_lang_Thread::priority(thread_oop());
2264 assert(prio != NoPriority, "A valid priority should be present");
2265 }
2266
2267 // Push the Java priority down to the native thread; needs Threads_lock
2268 Thread::set_priority(this, prio);
2269
2270 // Add the new thread to the Threads list and set it in motion.
2271 // We must have threads lock in order to call Threads::add.
2272 // It is crucial that we do not block before the thread is
2273 // added to the Threads list for if a GC happens, then the java_thread oop
2274 // will not be visited by GC.
2275 Threads::add(this);
2276 }
2277
2278 oop JavaThread::current_park_blocker() {
2279 // Support for JSR-166 locks
2280 oop thread_oop = threadObj();
2281 if (thread_oop != NULL) {
2282 return java_lang_Thread::park_blocker(thread_oop);
2283 }
2284 return NULL;
2285 }
2286
2287
2288 void JavaThread::print_stack_on(outputStream* st) {
2289 if (!has_last_Java_frame()) return;
2290
2291 Thread* current_thread = Thread::current();
2292 ResourceMark rm(current_thread);
2293 HandleMark hm(current_thread);
2294
2295 RegisterMap reg_map(this);
2296 vframe* start_vf = last_java_vframe(®_map);
2297 int count = 0;
2298 for (vframe* f = start_vf; f != NULL; f = f->sender()) {
2299 if (f->is_java_frame()) {
2300 javaVFrame* jvf = javaVFrame::cast(f);
2301 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2302
2303 // Print out lock information
2304 if (JavaMonitorsInStackTrace) {
2305 jvf->print_lock_info_on(st, count);
2306 }
2307 } else {
2308 // Ignore non-Java frames
2309 }
2310
2311 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
2312 count++;
2313 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
2314 }
2315 }
2316
2317
2318 // JVMTI PopFrame support
2319 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2320 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2321 if (in_bytes(size_in_bytes) != 0) {
2322 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
2323 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2324 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2325 }
2326 }
2327
2328 void* JavaThread::popframe_preserved_args() {
2329 return _popframe_preserved_args;
2330 }
2331
2332 ByteSize JavaThread::popframe_preserved_args_size() {
2333 return in_ByteSize(_popframe_preserved_args_size);
2334 }
2335
2336 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2337 int sz = in_bytes(popframe_preserved_args_size());
2338 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2339 return in_WordSize(sz / wordSize);
2340 }
2341
2342 void JavaThread::popframe_free_preserved_args() {
2343 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2344 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
2345 _popframe_preserved_args = NULL;
2346 _popframe_preserved_args_size = 0;
2347 }
2348
2349 #ifndef PRODUCT
2350
2351 void JavaThread::trace_frames() {
2352 tty->print_cr("[Describe stack]");
2353 int frame_no = 1;
2354 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2355 tty->print(" %d. ", frame_no++);
2356 fst.current()->print_value_on(tty, this);
2357 tty->cr();
2358 }
2359 }
2360
2361 class PrintAndVerifyOopClosure: public OopClosure {
2362 protected:
2363 template <class T> inline void do_oop_work(T* p) {
2364 oop obj = RawAccess<>::oop_load(p);
2365 if (obj == NULL) return;
2366 tty->print(INTPTR_FORMAT ": ", p2i(p));
2367 if (oopDesc::is_oop_or_null(obj)) {
2368 if (obj->is_objArray()) {
2369 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
2370 } else {
2371 obj->print();
2372 }
2373 } else {
2374 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
2375 }
2376 tty->cr();
2377 }
2378 public:
2379 virtual void do_oop(oop* p) { do_oop_work(p); }
2380 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
2381 };
2382
2383 #ifdef ASSERT
2384 // Print or validate the layout of stack frames
2385 void JavaThread::print_frame_layout(int depth, bool validate_only) {
2386 ResourceMark rm;
2387 PreserveExceptionMark pm(this);
2388 FrameValues values;
2389 int frame_no = 0;
2390 for (StackFrameStream fst(this, false /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2391 fst.current()->describe(values, ++frame_no);
2392 if (depth == frame_no) break;
2393 }
2394 if (validate_only) {
2395 values.validate();
2396 } else {
2397 tty->print_cr("[Describe stack layout]");
2398 values.print(this);
2399 }
2400 }
2401 #endif
2402
2403 void JavaThread::trace_stack_from(vframe* start_vf) {
2404 ResourceMark rm;
2405 int vframe_no = 1;
2406 for (vframe* f = start_vf; f; f = f->sender()) {
2407 if (f->is_java_frame()) {
2408 javaVFrame::cast(f)->print_activation(vframe_no++);
2409 } else {
2410 f->print();
2411 }
2412 if (vframe_no > StackPrintLimit) {
2413 tty->print_cr("...<more frames>...");
2414 return;
2415 }
2416 }
2417 }
2418
2419
2420 void JavaThread::trace_stack() {
2421 if (!has_last_Java_frame()) return;
2422 Thread* current_thread = Thread::current();
2423 ResourceMark rm(current_thread);
2424 HandleMark hm(current_thread);
2425 RegisterMap reg_map(this);
2426 trace_stack_from(last_java_vframe(®_map));
2427 }
2428
2429
2430 #endif // PRODUCT
2431
2432
2433 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2434 assert(reg_map != NULL, "a map must be given");
2435 frame f = last_frame();
2436 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
2437 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2438 }
2439 return NULL;
2440 }
2441
2442
2443 Klass* JavaThread::security_get_caller_class(int depth) {
2444 vframeStream vfst(this);
2445 vfst.security_get_caller_frame(depth);
2446 if (!vfst.at_end()) {
2447 return vfst.method()->method_holder();
2448 }
2449 return NULL;
2450 }
2451
2452 // java.lang.Thread.sleep support
2453 // Returns true if sleep time elapsed as expected, and false
2454 // if the thread was interrupted.
2455 bool JavaThread::sleep(jlong millis) {
2456 assert(this == Thread::current(), "thread consistency check");
2457
2458 ParkEvent * const slp = this->_SleepEvent;
2459 // Because there can be races with thread interruption sending an unpark()
2460 // to the event, we explicitly reset it here to avoid an immediate return.
2461 // The actual interrupt state will be checked before we park().
2462 slp->reset();
2463 // Thread interruption establishes a happens-before ordering in the
2464 // Java Memory Model, so we need to ensure we synchronize with the
2465 // interrupt state.
2466 OrderAccess::fence();
2467
2468 jlong prevtime = os::javaTimeNanos();
2469
2470 for (;;) {
2471 // interruption has precedence over timing out
2472 if (this->is_interrupted(true)) {
2473 return false;
2474 }
2475
2476 if (millis <= 0) {
2477 return true;
2478 }
2479
2480 {
2481 ThreadBlockInVM tbivm(this);
2482 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2483 slp->park(millis);
2484 }
2485
2486 // Update elapsed time tracking
2487 jlong newtime = os::javaTimeNanos();
2488 if (newtime - prevtime < 0) {
2489 // time moving backwards, should only happen if no monotonic clock
2490 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2491 assert(false,
2492 "unexpected time moving backwards detected in JavaThread::sleep()");
2493 } else {
2494 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2495 }
2496 prevtime = newtime;
2497 }
2498 }
2499
2500
2501 // ======= Threads ========
2502
2503 // The Threads class links together all active threads, and provides
2504 // operations over all threads. It is protected by the Threads_lock,
2505 // which is also used in other global contexts like safepointing.
2506 // ThreadsListHandles are used to safely perform operations on one
2507 // or more threads without the risk of the thread exiting during the
2508 // operation.
2509 //
2510 // Note: The Threads_lock is currently more widely used than we
2511 // would like. We are actively migrating Threads_lock uses to other
2512 // mechanisms in order to reduce Threads_lock contention.
2513
2514 int Threads::_number_of_threads = 0;
2515 int Threads::_number_of_non_daemon_threads = 0;
2516 int Threads::_return_code = 0;
2517 uintx Threads::_thread_claim_token = 1; // Never zero.
2518 size_t JavaThread::_stack_size_at_create = 0;
2519
2520 #ifdef ASSERT
2521 bool Threads::_vm_complete = false;
2522 #endif
2523
2524 static inline void *prefetch_and_load_ptr(void **addr, intx prefetch_interval) {
2525 Prefetch::read((void*)addr, prefetch_interval);
2526 return *addr;
2527 }
2528
2529 // Possibly the ugliest for loop the world has seen. C++ does not allow
2530 // multiple types in the declaration section of the for loop. In this case
2531 // we are only dealing with pointers and hence can cast them. It looks ugly
2532 // but macros are ugly and therefore it's fine to make things absurdly ugly.
2533 #define DO_JAVA_THREADS(LIST, X) \
2534 for (JavaThread *MACRO_scan_interval = (JavaThread*)(uintptr_t)PrefetchScanIntervalInBytes, \
2535 *MACRO_list = (JavaThread*)(LIST), \
2536 **MACRO_end = ((JavaThread**)((ThreadsList*)MACRO_list)->threads()) + ((ThreadsList*)MACRO_list)->length(), \
2537 **MACRO_current_p = (JavaThread**)((ThreadsList*)MACRO_list)->threads(), \
2538 *X = (JavaThread*)prefetch_and_load_ptr((void**)MACRO_current_p, (intx)MACRO_scan_interval); \
2539 MACRO_current_p != MACRO_end; \
2540 MACRO_current_p++, \
2541 X = (JavaThread*)prefetch_and_load_ptr((void**)MACRO_current_p, (intx)MACRO_scan_interval))
2542
2543 // All JavaThreads
2544 #define ALL_JAVA_THREADS(X) DO_JAVA_THREADS(ThreadsSMRSupport::get_java_thread_list(), X)
2545
2546 // All NonJavaThreads (i.e., every non-JavaThread in the system).
2547 void Threads::non_java_threads_do(ThreadClosure* tc) {
2548 NoSafepointVerifier nsv;
2549 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
2550 tc->do_thread(njti.current());
2551 }
2552 }
2553
2554 // All JavaThreads
2555 void Threads::java_threads_do(ThreadClosure* tc) {
2556 assert_locked_or_safepoint(Threads_lock);
2557 // ALL_JAVA_THREADS iterates through all JavaThreads.
2558 ALL_JAVA_THREADS(p) {
2559 tc->do_thread(p);
2560 }
2561 }
2562
2563 void Threads::java_threads_and_vm_thread_do(ThreadClosure* tc) {
2564 assert_locked_or_safepoint(Threads_lock);
2565 java_threads_do(tc);
2566 tc->do_thread(VMThread::vm_thread());
2567 }
2568
2569 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
2570 void Threads::threads_do(ThreadClosure* tc) {
2571 assert_locked_or_safepoint(Threads_lock);
2572 java_threads_do(tc);
2573 non_java_threads_do(tc);
2574 }
2575
2576 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
2577 uintx claim_token = Threads::thread_claim_token();
2578 ALL_JAVA_THREADS(p) {
2579 if (p->claim_threads_do(is_par, claim_token)) {
2580 tc->do_thread(p);
2581 }
2582 }
2583 VMThread* vmt = VMThread::vm_thread();
2584 if (vmt->claim_threads_do(is_par, claim_token)) {
2585 tc->do_thread(vmt);
2586 }
2587 }
2588
2589 // The system initialization in the library has three phases.
2590 //
2591 // Phase 1: java.lang.System class initialization
2592 // java.lang.System is a primordial class loaded and initialized
2593 // by the VM early during startup. java.lang.System.<clinit>
2594 // only does registerNatives and keeps the rest of the class
2595 // initialization work later until thread initialization completes.
2596 //
2597 // System.initPhase1 initializes the system properties, the static
2598 // fields in, out, and err. Set up java signal handlers, OS-specific
2599 // system settings, and thread group of the main thread.
2600 static void call_initPhase1(TRAPS) {
2601 Klass* klass = vmClasses::System_klass();
2602 JavaValue result(T_VOID);
2603 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
2604 vmSymbols::void_method_signature(), CHECK);
2605 }
2606
2607 // Phase 2. Module system initialization
2608 // This will initialize the module system. Only java.base classes
2609 // can be loaded until phase 2 completes.
2610 //
2611 // Call System.initPhase2 after the compiler initialization and jsr292
2612 // classes get initialized because module initialization runs a lot of java
2613 // code, that for performance reasons, should be compiled. Also, this will
2614 // enable the startup code to use lambda and other language features in this
2615 // phase and onward.
2616 //
2617 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
2618 static void call_initPhase2(TRAPS) {
2619 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
2620
2621 Klass* klass = vmClasses::System_klass();
2622
2623 JavaValue result(T_INT);
2624 JavaCallArguments args;
2625 args.push_int(DisplayVMOutputToStderr);
2626 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
2627 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
2628 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
2629 if (result.get_jint() != JNI_OK) {
2630 vm_exit_during_initialization(); // no message or exception
2631 }
2632
2633 universe_post_module_init();
2634 }
2635
2636 // Phase 3. final setup - set security manager, system class loader and TCCL
2637 //
2638 // This will instantiate and set the security manager, set the system class
2639 // loader as well as the thread context class loader. The security manager
2640 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
2641 // other modules or the application's classpath.
2642 static void call_initPhase3(TRAPS) {
2643 Klass* klass = vmClasses::System_klass();
2644 JavaValue result(T_VOID);
2645 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
2646 vmSymbols::void_method_signature(), CHECK);
2647 }
2648
2649 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
2650 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
2651
2652 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
2653 create_vm_init_libraries();
2654 }
2655
2656 initialize_class(vmSymbols::java_lang_String(), CHECK);
2657
2658 // Inject CompactStrings value after the static initializers for String ran.
2659 java_lang_String::set_compact_strings(CompactStrings);
2660
2661 // Initialize java_lang.System (needed before creating the thread)
2662 initialize_class(vmSymbols::java_lang_System(), CHECK);
2663 // The VM creates & returns objects of this class. Make sure it's initialized.
2664 initialize_class(vmSymbols::java_lang_Class(), CHECK);
2665 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
2666 Handle thread_group = create_initial_thread_group(CHECK);
2667 Universe::set_main_thread_group(thread_group());
2668 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
2669 create_initial_thread(thread_group, main_thread, CHECK);
2670
2671 // The VM creates objects of this class.
2672 initialize_class(vmSymbols::java_lang_Module(), CHECK);
2673
2674 #ifdef ASSERT
2675 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
2676 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
2677 #endif
2678
2679 // initialize the hardware-specific constants needed by Unsafe
2680 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
2681 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
2682
2683 // The VM preresolves methods to these classes. Make sure that they get initialized
2684 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
2685 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
2686
2687 // Phase 1 of the system initialization in the library, java.lang.System class initialization
2688 call_initPhase1(CHECK);
2689
2690 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
2691 // Some values are actually configure-time constants but some can be set via the jlink tool and
2692 // so must be read dynamically. We treat them all the same.
2693 InstanceKlass* ik = SystemDictionary::find_instance_klass(vmSymbols::java_lang_VersionProps(),
2694 Handle(), Handle());
2695 {
2696 ResourceMark rm(main_thread);
2697 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
2698
2699 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
2700
2701 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
2702
2703 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
2704
2705 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
2706 }
2707
2708 // an instance of OutOfMemory exception has been allocated earlier
2709 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
2710 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
2711 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
2712 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
2713 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
2714 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
2715 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
2716 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
2717 }
2718
2719 void Threads::initialize_jsr292_core_classes(TRAPS) {
2720 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
2721
2722 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
2723 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
2724 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
2725 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
2726 }
2727
2728 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2729 extern void JDK_Version_init();
2730
2731 // Preinitialize version info.
2732 VM_Version::early_initialize();
2733
2734 // Check version
2735 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2736
2737 // Initialize library-based TLS
2738 ThreadLocalStorage::init();
2739
2740 // Initialize the output stream module
2741 ostream_init();
2742
2743 // Process java launcher properties.
2744 Arguments::process_sun_java_launcher_properties(args);
2745
2746 // Initialize the os module
2747 os::init();
2748
2749 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
2750
2751 // Record VM creation timing statistics
2752 TraceVmCreationTime create_vm_timer;
2753 create_vm_timer.start();
2754
2755 // Initialize system properties.
2756 Arguments::init_system_properties();
2757
2758 // So that JDK version can be used as a discriminator when parsing arguments
2759 JDK_Version_init();
2760
2761 // Update/Initialize System properties after JDK version number is known
2762 Arguments::init_version_specific_system_properties();
2763
2764 // Make sure to initialize log configuration *before* parsing arguments
2765 LogConfiguration::initialize(create_vm_timer.begin_time());
2766
2767 // Parse arguments
2768 // Note: this internally calls os::init_container_support()
2769 jint parse_result = Arguments::parse(args);
2770 if (parse_result != JNI_OK) return parse_result;
2771
2772 #if INCLUDE_NMT
2773 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
2774 MemTracker::initialize();
2775 #endif // INCLUDE_NMT
2776
2777 os::init_before_ergo();
2778
2779 jint ergo_result = Arguments::apply_ergo();
2780 if (ergo_result != JNI_OK) return ergo_result;
2781
2782 // Final check of all ranges after ergonomics which may change values.
2783 if (!JVMFlagLimit::check_all_ranges()) {
2784 return JNI_EINVAL;
2785 }
2786
2787 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
2788 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
2789 if (!constraint_result) {
2790 return JNI_EINVAL;
2791 }
2792
2793 if (PauseAtStartup) {
2794 os::pause();
2795 }
2796
2797 HOTSPOT_VM_INIT_BEGIN();
2798
2799 // Timing (must come after argument parsing)
2800 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
2801
2802 // Initialize the os module after parsing the args
2803 jint os_init_2_result = os::init_2();
2804 if (os_init_2_result != JNI_OK) return os_init_2_result;
2805
2806 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
2807 // Initialize assert poison page mechanism.
2808 if (ShowRegistersOnAssert) {
2809 initialize_assert_poison();
2810 }
2811 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
2812
2813 SafepointMechanism::initialize();
2814
2815 jint adjust_after_os_result = Arguments::adjust_after_os();
2816 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
2817
2818 // Initialize output stream logging
2819 ostream_init_log();
2820
2821 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2822 // Must be before create_vm_init_agents()
2823 if (Arguments::init_libraries_at_startup()) {
2824 convert_vm_init_libraries_to_agents();
2825 }
2826
2827 // Launch -agentlib/-agentpath and converted -Xrun agents
2828 if (Arguments::init_agents_at_startup()) {
2829 create_vm_init_agents();
2830 }
2831
2832 // Initialize Threads state
2833 _number_of_threads = 0;
2834 _number_of_non_daemon_threads = 0;
2835
2836 // Initialize global data structures and create system classes in heap
2837 vm_init_globals();
2838
2839 #if INCLUDE_JVMCI
2840 if (JVMCICounterSize > 0) {
2841 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
2842 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
2843 } else {
2844 JavaThread::_jvmci_old_thread_counters = NULL;
2845 }
2846 #endif // INCLUDE_JVMCI
2847
2848 // Initialize OopStorage for threadObj
2849 _thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
2850
2851 // Attach the main thread to this os thread
2852 JavaThread* main_thread = new JavaThread();
2853 main_thread->set_thread_state(_thread_in_vm);
2854 main_thread->initialize_thread_current();
2855 // must do this before set_active_handles
2856 main_thread->record_stack_base_and_size();
2857 main_thread->register_thread_stack_with_NMT();
2858 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2859 MACOS_AARCH64_ONLY(main_thread->init_wx());
2860
2861 if (!main_thread->set_as_starting_thread()) {
2862 vm_shutdown_during_initialization(
2863 "Failed necessary internal allocation. Out of swap space");
2864 main_thread->smr_delete();
2865 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2866 return JNI_ENOMEM;
2867 }
2868
2869 // Enable guard page *after* os::create_main_thread(), otherwise it would
2870 // crash Linux VM, see notes in os_linux.cpp.
2871 main_thread->stack_overflow_state()->create_stack_guard_pages();
2872
2873 // Initialize Java-Level synchronization subsystem
2874 ObjectMonitor::Initialize();
2875 ObjectSynchronizer::initialize();
2876
2877 // Initialize global modules
2878 jint status = init_globals();
2879 if (status != JNI_OK) {
2880 main_thread->smr_delete();
2881 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2882 return status;
2883 }
2884
2885 JFR_ONLY(Jfr::on_create_vm_1();)
2886
2887 // Should be done after the heap is fully created
2888 main_thread->cache_global_variables();
2889
2890 { MutexLocker mu(Threads_lock);
2891 Threads::add(main_thread);
2892 }
2893
2894 // Any JVMTI raw monitors entered in onload will transition into
2895 // real raw monitor. VM is setup enough here for raw monitor enter.
2896 JvmtiExport::transition_pending_onload_raw_monitors();
2897
2898 // Create the VMThread
2899 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
2900
2901 VMThread::create();
2902 Thread* vmthread = VMThread::vm_thread();
2903
2904 if (!os::create_thread(vmthread, os::vm_thread)) {
2905 vm_exit_during_initialization("Cannot create VM thread. "
2906 "Out of system resources.");
2907 }
2908
2909 // Wait for the VM thread to become ready, and VMThread::run to initialize
2910 // Monitors can have spurious returns, must always check another state flag
2911 {
2912 MonitorLocker ml(Notify_lock);
2913 os::start_thread(vmthread);
2914 while (vmthread->active_handles() == NULL) {
2915 ml.wait();
2916 }
2917 }
2918 }
2919
2920 assert(Universe::is_fully_initialized(), "not initialized");
2921 if (VerifyDuringStartup) {
2922 // Make sure we're starting with a clean slate.
2923 VM_Verify verify_op;
2924 VMThread::execute(&verify_op);
2925 }
2926
2927 // We need this to update the java.vm.info property in case any flags used
2928 // to initially define it have been changed. This is needed for both CDS
2929 // since UseSharedSpaces may be changed after java.vm.info
2930 // is initially computed. See Abstract_VM_Version::vm_info_string().
2931 // This update must happen before we initialize the java classes, but
2932 // after any initialization logic that might modify the flags.
2933 Arguments::update_vm_info_property(VM_Version::vm_info_string());
2934
2935 JavaThread* THREAD = JavaThread::current(); // For exception macros.
2936 HandleMark hm(THREAD);
2937
2938 // Always call even when there are not JVMTI environments yet, since environments
2939 // may be attached late and JVMTI must track phases of VM execution
2940 JvmtiExport::enter_early_start_phase();
2941
2942 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
2943 JvmtiExport::post_early_vm_start();
2944
2945 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
2946
2947 quicken_jni_functions();
2948
2949 // No more stub generation allowed after that point.
2950 StubCodeDesc::freeze();
2951
2952 // Set flag that basic initialization has completed. Used by exceptions and various
2953 // debug stuff, that does not work until all basic classes have been initialized.
2954 set_init_completed();
2955
2956 LogConfiguration::post_initialize();
2957 Metaspace::post_initialize();
2958
2959 HOTSPOT_VM_INIT_END();
2960
2961 // record VM initialization completion time
2962 #if INCLUDE_MANAGEMENT
2963 Management::record_vm_init_completed();
2964 #endif // INCLUDE_MANAGEMENT
2965
2966 // Signal Dispatcher needs to be started before VMInit event is posted
2967 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
2968
2969 // Start Attach Listener if +StartAttachListener or it can't be started lazily
2970 if (!DisableAttachMechanism) {
2971 AttachListener::vm_start();
2972 if (StartAttachListener || AttachListener::init_at_startup()) {
2973 AttachListener::init();
2974 }
2975 }
2976
2977 // Launch -Xrun agents
2978 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
2979 // back-end can launch with -Xdebug -Xrunjdwp.
2980 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
2981 create_vm_init_libraries();
2982 }
2983
2984 Chunk::start_chunk_pool_cleaner_task();
2985
2986 // Start the service thread
2987 // The service thread enqueues JVMTI deferred events and does various hashtable
2988 // and other cleanups. Needs to start before the compilers start posting events.
2989 ServiceThread::initialize();
2990
2991 // Start the monitor deflation thread:
2992 MonitorDeflationThread::initialize();
2993
2994 // initialize compiler(s)
2995 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
2996 #if INCLUDE_JVMCI
2997 bool force_JVMCI_intialization = false;
2998 if (EnableJVMCI) {
2999 // Initialize JVMCI eagerly when it is explicitly requested.
3000 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
3001 force_JVMCI_intialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
3002
3003 if (!force_JVMCI_intialization) {
3004 // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking
3005 // compilations via JVMCI will not actually block until JVMCI is initialized.
3006 force_JVMCI_intialization = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation);
3007 }
3008 }
3009 #endif
3010 CompileBroker::compilation_init_phase1(CHECK_JNI_ERR);
3011 // Postpone completion of compiler initialization to after JVMCI
3012 // is initialized to avoid timeouts of blocking compilations.
3013 if (JVMCI_ONLY(!force_JVMCI_intialization) NOT_JVMCI(true)) {
3014 CompileBroker::compilation_init_phase2();
3015 }
3016 #endif
3017
3018 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
3019 // It is done after compilers are initialized, because otherwise compilations of
3020 // signature polymorphic MH intrinsics can be missed
3021 // (see SystemDictionary::find_method_handle_intrinsic).
3022 initialize_jsr292_core_classes(CHECK_JNI_ERR);
3023
3024 // This will initialize the module system. Only java.base classes can be
3025 // loaded until phase 2 completes
3026 call_initPhase2(CHECK_JNI_ERR);
3027
3028 JFR_ONLY(Jfr::on_create_vm_2();)
3029
3030 // Always call even when there are not JVMTI environments yet, since environments
3031 // may be attached late and JVMTI must track phases of VM execution
3032 JvmtiExport::enter_start_phase();
3033
3034 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3035 JvmtiExport::post_vm_start();
3036
3037 // Final system initialization including security manager and system class loader
3038 call_initPhase3(CHECK_JNI_ERR);
3039
3040 // cache the system and platform class loaders
3041 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
3042
3043 #if INCLUDE_CDS
3044 // capture the module path info from the ModuleEntryTable
3045 ClassLoader::initialize_module_path(THREAD);
3046 if (HAS_PENDING_EXCEPTION) {
3047 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
3048 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
3049 }
3050 #endif
3051
3052 #if INCLUDE_JVMCI
3053 if (force_JVMCI_intialization) {
3054 JVMCI::initialize_compiler(CHECK_JNI_ERR);
3055 CompileBroker::compilation_init_phase2();
3056 }
3057 #endif
3058
3059 // Always call even when there are not JVMTI environments yet, since environments
3060 // may be attached late and JVMTI must track phases of VM execution
3061 JvmtiExport::enter_live_phase();
3062
3063 // Make perfmemory accessible
3064 PerfMemory::set_accessible(true);
3065
3066 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3067 JvmtiExport::post_vm_initialized();
3068
3069 JFR_ONLY(Jfr::on_create_vm_3();)
3070
3071 #if INCLUDE_MANAGEMENT
3072 Management::initialize(THREAD);
3073
3074 if (HAS_PENDING_EXCEPTION) {
3075 // management agent fails to start possibly due to
3076 // configuration problem and is responsible for printing
3077 // stack trace if appropriate. Simply exit VM.
3078 vm_exit(1);
3079 }
3080 #endif // INCLUDE_MANAGEMENT
3081
3082 StatSampler::engage();
3083 if (CheckJNICalls) JniPeriodicChecker::engage();
3084
3085 BiasedLocking::init();
3086
3087 #if INCLUDE_RTM_OPT
3088 RTMLockingCounters::init();
3089 #endif
3090
3091 call_postVMInitHook(THREAD);
3092 // The Java side of PostVMInitHook.run must deal with all
3093 // exceptions and provide means of diagnosis.
3094 if (HAS_PENDING_EXCEPTION) {
3095 CLEAR_PENDING_EXCEPTION;
3096 }
3097
3098 {
3099 MutexLocker ml(PeriodicTask_lock);
3100 // Make sure the WatcherThread can be started by WatcherThread::start()
3101 // or by dynamic enrollment.
3102 WatcherThread::make_startable();
3103 // Start up the WatcherThread if there are any periodic tasks
3104 // NOTE: All PeriodicTasks should be registered by now. If they
3105 // aren't, late joiners might appear to start slowly (we might
3106 // take a while to process their first tick).
3107 if (PeriodicTask::num_tasks() > 0) {
3108 WatcherThread::start();
3109 }
3110 }
3111
3112 create_vm_timer.end();
3113 #ifdef ASSERT
3114 _vm_complete = true;
3115 #endif
3116
3117 if (DumpSharedSpaces) {
3118 MetaspaceShared::preload_and_dump();
3119 ShouldNotReachHere();
3120 }
3121
3122 return JNI_OK;
3123 }
3124
3125 // type for the Agent_OnLoad and JVM_OnLoad entry points
3126 extern "C" {
3127 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3128 }
3129 // Find a command line agent library and return its entry point for
3130 // -agentlib: -agentpath: -Xrun
3131 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3132 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent,
3133 const char *on_load_symbols[],
3134 size_t num_symbol_entries) {
3135 OnLoadEntry_t on_load_entry = NULL;
3136 void *library = NULL;
3137
3138 if (!agent->valid()) {
3139 char buffer[JVM_MAXPATHLEN];
3140 char ebuf[1024] = "";
3141 const char *name = agent->name();
3142 const char *msg = "Could not find agent library ";
3143
3144 // First check to see if agent is statically linked into executable
3145 if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
3146 library = agent->os_lib();
3147 } else if (agent->is_absolute_path()) {
3148 library = os::dll_load(name, ebuf, sizeof ebuf);
3149 if (library == NULL) {
3150 const char *sub_msg = " in absolute path, with error: ";
3151 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3152 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3153 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3154 // If we can't find the agent, exit.
3155 vm_exit_during_initialization(buf, NULL);
3156 FREE_C_HEAP_ARRAY(char, buf);
3157 }
3158 } else {
3159 // Try to load the agent from the standard dll directory
3160 if (os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
3161 name)) {
3162 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3163 }
3164 if (library == NULL) { // Try the library path directory.
3165 if (os::dll_build_name(buffer, sizeof(buffer), name)) {
3166 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3167 }
3168 if (library == NULL) {
3169 const char *sub_msg = " on the library path, with error: ";
3170 const char *sub_msg2 = "\nModule java.instrument may be missing from runtime image.";
3171
3172 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) +
3173 strlen(ebuf) + strlen(sub_msg2) + 1;
3174 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3175 if (!agent->is_instrument_lib()) {
3176 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3177 } else {
3178 jio_snprintf(buf, len, "%s%s%s%s%s", msg, name, sub_msg, ebuf, sub_msg2);
3179 }
3180 // If we can't find the agent, exit.
3181 vm_exit_during_initialization(buf, NULL);
3182 FREE_C_HEAP_ARRAY(char, buf);
3183 }
3184 }
3185 }
3186 agent->set_os_lib(library);
3187 agent->set_valid();
3188 }
3189
3190 // Find the OnLoad function.
3191 on_load_entry =
3192 CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
3193 false,
3194 on_load_symbols,
3195 num_symbol_entries));
3196 return on_load_entry;
3197 }
3198
3199 // Find the JVM_OnLoad entry point
3200 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3201 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3202 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3203 }
3204
3205 // Find the Agent_OnLoad entry point
3206 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3207 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3208 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3209 }
3210
3211 // For backwards compatibility with -Xrun
3212 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3213 // treated like -agentpath:
3214 // Must be called before agent libraries are created
3215 void Threads::convert_vm_init_libraries_to_agents() {
3216 AgentLibrary* agent;
3217 AgentLibrary* next;
3218
3219 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3220 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3221 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3222
3223 // If there is an JVM_OnLoad function it will get called later,
3224 // otherwise see if there is an Agent_OnLoad
3225 if (on_load_entry == NULL) {
3226 on_load_entry = lookup_agent_on_load(agent);
3227 if (on_load_entry != NULL) {
3228 // switch it to the agent list -- so that Agent_OnLoad will be called,
3229 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3230 Arguments::convert_library_to_agent(agent);
3231 } else {
3232 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3233 }
3234 }
3235 }
3236 }
3237
3238 // Create agents for -agentlib: -agentpath: and converted -Xrun
3239 // Invokes Agent_OnLoad
3240 // Called very early -- before JavaThreads exist
3241 void Threads::create_vm_init_agents() {
3242 extern struct JavaVM_ main_vm;
3243 AgentLibrary* agent;
3244
3245 JvmtiExport::enter_onload_phase();
3246
3247 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3248 // CDS dumping does not support native JVMTI agent.
3249 // CDS dumping supports Java agent if the AllowArchivingWithJavaAgent diagnostic option is specified.
3250 if (Arguments::is_dumping_archive()) {
3251 if(!agent->is_instrument_lib()) {
3252 vm_exit_during_cds_dumping("CDS dumping does not support native JVMTI agent, name", agent->name());
3253 } else if (!AllowArchivingWithJavaAgent) {
3254 vm_exit_during_cds_dumping(
3255 "Must enable AllowArchivingWithJavaAgent in order to run Java agent during CDS dumping");
3256 }
3257 }
3258
3259 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3260
3261 if (on_load_entry != NULL) {
3262 // Invoke the Agent_OnLoad function
3263 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3264 if (err != JNI_OK) {
3265 vm_exit_during_initialization("agent library failed to init", agent->name());
3266 }
3267 } else {
3268 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3269 }
3270 }
3271
3272 JvmtiExport::enter_primordial_phase();
3273 }
3274
3275 extern "C" {
3276 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3277 }
3278
3279 void Threads::shutdown_vm_agents() {
3280 // Send any Agent_OnUnload notifications
3281 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3282 size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
3283 extern struct JavaVM_ main_vm;
3284 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3285
3286 // Find the Agent_OnUnload function.
3287 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3288 os::find_agent_function(agent,
3289 false,
3290 on_unload_symbols,
3291 num_symbol_entries));
3292
3293 // Invoke the Agent_OnUnload function
3294 if (unload_entry != NULL) {
3295 JavaThread* thread = JavaThread::current();
3296 ThreadToNativeFromVM ttn(thread);
3297 HandleMark hm(thread);
3298 (*unload_entry)(&main_vm);
3299 }
3300 }
3301 }
3302
3303 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3304 // Invokes JVM_OnLoad
3305 void Threads::create_vm_init_libraries() {
3306 extern struct JavaVM_ main_vm;
3307 AgentLibrary* agent;
3308
3309 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3310 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3311
3312 if (on_load_entry != NULL) {
3313 // Invoke the JVM_OnLoad function
3314 JavaThread* thread = JavaThread::current();
3315 ThreadToNativeFromVM ttn(thread);
3316 HandleMark hm(thread);
3317 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3318 if (err != JNI_OK) {
3319 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3320 }
3321 } else {
3322 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3323 }
3324 }
3325 }
3326
3327
3328 // Last thread running calls java.lang.Shutdown.shutdown()
3329 void JavaThread::invoke_shutdown_hooks() {
3330 HandleMark hm(this);
3331
3332 // We could get here with a pending exception, if so clear it now or
3333 // it will cause MetaspaceShared::link_and_cleanup_shared_classes to
3334 // fail for dynamic dump.
3335 if (this->has_pending_exception()) {
3336 this->clear_pending_exception();
3337 }
3338
3339 #if INCLUDE_CDS
3340 // Link all classes for dynamic CDS dumping before vm exit.
3341 // Same operation is being done in JVM_BeforeHalt for handling the
3342 // case where the application calls System.exit().
3343 if (DynamicDumpSharedSpaces) {
3344 DynamicArchive::prepare_for_dynamic_dumping_at_exit();
3345 }
3346 #endif
3347
3348 EXCEPTION_MARK;
3349 Klass* shutdown_klass =
3350 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3351 THREAD);
3352 if (shutdown_klass != NULL) {
3353 // SystemDictionary::resolve_or_null will return null if there was
3354 // an exception. If we cannot load the Shutdown class, just don't
3355 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3356 // won't be run. Note that if a shutdown hook was registered,
3357 // the Shutdown class would have already been loaded
3358 // (Runtime.addShutdownHook will load it).
3359 JavaValue result(T_VOID);
3360 JavaCalls::call_static(&result,
3361 shutdown_klass,
3362 vmSymbols::shutdown_name(),
3363 vmSymbols::void_method_signature(),
3364 THREAD);
3365 }
3366 CLEAR_PENDING_EXCEPTION;
3367 }
3368
3369 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3370 // the program falls off the end of main(). Another VM exit path is through
3371 // vm_exit() when the program calls System.exit() to return a value or when
3372 // there is a serious error in VM. The two shutdown paths are not exactly
3373 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3374 // and VM_Exit op at VM level.
3375 //
3376 // Shutdown sequence:
3377 // + Shutdown native memory tracking if it is on
3378 // + Wait until we are the last non-daemon thread to execute
3379 // <-- every thing is still working at this moment -->
3380 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3381 // shutdown hooks
3382 // + Call before_exit(), prepare for VM exit
3383 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3384 // currently the only user of this mechanism is File.deleteOnExit())
3385 // > stop StatSampler, watcher thread,
3386 // post thread end and vm death events to JVMTI,
3387 // stop signal thread
3388 // + Call JavaThread::exit(), it will:
3389 // > release JNI handle blocks, remove stack guard pages
3390 // > remove this thread from Threads list
3391 // <-- no more Java code from this thread after this point -->
3392 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3393 // the compiler threads at safepoint
3394 // <-- do not use anything that could get blocked by Safepoint -->
3395 // + Disable tracing at JNI/JVM barriers
3396 // + Set _vm_exited flag for threads that are still running native code
3397 // + Call exit_globals()
3398 // > deletes tty
3399 // > deletes PerfMemory resources
3400 // + Delete this thread
3401 // + Return to caller
3402
3403 void Threads::destroy_vm() {
3404 JavaThread* thread = JavaThread::current();
3405
3406 #ifdef ASSERT
3407 _vm_complete = false;
3408 #endif
3409 // Wait until we are the last non-daemon thread to execute
3410 {
3411 MonitorLocker nu(Threads_lock);
3412 while (Threads::number_of_non_daemon_threads() > 1)
3413 // This wait should make safepoint checks, wait without a timeout.
3414 nu.wait(0);
3415 }
3416
3417 EventShutdown e;
3418 if (e.should_commit()) {
3419 e.set_reason("No remaining non-daemon Java threads");
3420 e.commit();
3421 }
3422
3423 // Hang forever on exit if we are reporting an error.
3424 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
3425 os::infinite_sleep();
3426 }
3427 os::wait_for_keypress_at_exit();
3428
3429 // run Java level shutdown hooks
3430 thread->invoke_shutdown_hooks();
3431
3432 before_exit(thread);
3433
3434 thread->exit(true);
3435
3436 // We are no longer on the main thread list but could still be in a
3437 // secondary list where another thread may try to interact with us.
3438 // So wait until all such interactions are complete before we bring
3439 // the VM to the termination safepoint. Normally this would be done
3440 // using thread->smr_delete() below where we delete the thread, but
3441 // we can't call that after the termination safepoint is active as
3442 // we will deadlock on the Threads_lock. Once all interactions are
3443 // complete it is safe to directly delete the thread at any time.
3444 ThreadsSMRSupport::wait_until_not_protected(thread);
3445
3446 // Stop VM thread.
3447 {
3448 // 4945125 The vm thread comes to a safepoint during exit.
3449 // GC vm_operations can get caught at the safepoint, and the
3450 // heap is unparseable if they are caught. Grab the Heap_lock
3451 // to prevent this. The GC vm_operations will not be able to
3452 // queue until after the vm thread is dead. After this point,
3453 // we'll never emerge out of the safepoint before the VM exits.
3454 // Assert that the thread is terminated so that acquiring the
3455 // Heap_lock doesn't cause the terminated thread to participate in
3456 // the safepoint protocol.
3457
3458 assert(thread->is_terminated(), "must be terminated here");
3459 MutexLocker ml(Heap_lock);
3460
3461 VMThread::wait_for_vm_thread_exit();
3462 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3463 VMThread::destroy();
3464 }
3465
3466 // Now, all Java threads are gone except daemon threads. Daemon threads
3467 // running Java code or in VM are stopped by the Safepoint. However,
3468 // daemon threads executing native code are still running. But they
3469 // will be stopped at native=>Java/VM barriers. Note that we can't
3470 // simply kill or suspend them, as it is inherently deadlock-prone.
3471
3472 VM_Exit::set_vm_exited();
3473
3474 // Clean up ideal graph printers after the VMThread has started
3475 // the final safepoint which will block all the Compiler threads.
3476 // Note that this Thread has already logically exited so the
3477 // clean_up() function's use of a JavaThreadIteratorWithHandle
3478 // would be a problem except set_vm_exited() has remembered the
3479 // shutdown thread which is granted a policy exception.
3480 #if defined(COMPILER2) && !defined(PRODUCT)
3481 IdealGraphPrinter::clean_up();
3482 #endif
3483
3484 notify_vm_shutdown();
3485
3486 // exit_globals() will delete tty
3487 exit_globals();
3488
3489 // Deleting the shutdown thread here is safe. See comment on
3490 // wait_until_not_protected() above.
3491 delete thread;
3492
3493 #if INCLUDE_JVMCI
3494 if (JVMCICounterSize > 0) {
3495 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
3496 }
3497 #endif
3498
3499 LogConfiguration::finalize();
3500 }
3501
3502
3503 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3504 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3505 return is_supported_jni_version(version);
3506 }
3507
3508
3509 jboolean Threads::is_supported_jni_version(jint version) {
3510 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3511 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3512 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3513 if (version == JNI_VERSION_1_8) return JNI_TRUE;
3514 if (version == JNI_VERSION_9) return JNI_TRUE;
3515 if (version == JNI_VERSION_10) return JNI_TRUE;
3516 return JNI_FALSE;
3517 }
3518
3519
3520 void Threads::add(JavaThread* p, bool force_daemon) {
3521 // The threads lock must be owned at this point
3522 assert(Threads_lock->owned_by_self(), "must have threads lock");
3523
3524 BarrierSet::barrier_set()->on_thread_attach(p);
3525
3526 // Once a JavaThread is added to the Threads list, smr_delete() has
3527 // to be used to delete it. Otherwise we can just delete it directly.
3528 p->set_on_thread_list();
3529
3530 _number_of_threads++;
3531 oop threadObj = p->threadObj();
3532 bool daemon = true;
3533 // Bootstrapping problem: threadObj can be null for initial
3534 // JavaThread (or for threads attached via JNI)
3535 if ((!force_daemon) && !is_daemon((threadObj))) {
3536 _number_of_non_daemon_threads++;
3537 daemon = false;
3538 }
3539
3540 ThreadService::add_thread(p, daemon);
3541
3542 // Maintain fast thread list
3543 ThreadsSMRSupport::add_thread(p);
3544
3545 // Increase the ObjectMonitor ceiling for the new thread.
3546 ObjectSynchronizer::inc_in_use_list_ceiling();
3547
3548 // Possible GC point.
3549 Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
3550
3551 // Make new thread known to active EscapeBarrier
3552 EscapeBarrier::thread_added(p);
3553 }
3554
3555 void Threads::remove(JavaThread* p, bool is_daemon) {
3556 // Extra scope needed for Thread_lock, so we can check
3557 // that we do not remove thread without safepoint code notice
3558 { MonitorLocker ml(Threads_lock);
3559
3560 // BarrierSet state must be destroyed after the last thread transition
3561 // before the thread terminates. Thread transitions result in calls to
3562 // StackWatermarkSet::on_safepoint(), which performs GC processing,
3563 // requiring the GC state to be alive.
3564 BarrierSet::barrier_set()->on_thread_detach(p);
3565
3566 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
3567
3568 // Maintain fast thread list
3569 ThreadsSMRSupport::remove_thread(p);
3570
3571 _number_of_threads--;
3572 if (!is_daemon) {
3573 _number_of_non_daemon_threads--;
3574
3575 // Only one thread left, do a notify on the Threads_lock so a thread waiting
3576 // on destroy_vm will wake up.
3577 if (number_of_non_daemon_threads() == 1) {
3578 ml.notify_all();
3579 }
3580 }
3581 ThreadService::remove_thread(p, is_daemon);
3582
3583 // Make sure that safepoint code disregard this thread. This is needed since
3584 // the thread might mess around with locks after this point. This can cause it
3585 // to do callbacks into the safepoint code. However, the safepoint code is not aware
3586 // of this thread since it is removed from the queue.
3587 p->set_terminated(JavaThread::_thread_terminated);
3588
3589 // Notify threads waiting in EscapeBarriers
3590 EscapeBarrier::thread_removed(p);
3591 } // unlock Threads_lock
3592
3593 // Reduce the ObjectMonitor ceiling for the exiting thread.
3594 ObjectSynchronizer::dec_in_use_list_ceiling();
3595
3596 // Since Events::log uses a lock, we grab it outside the Threads_lock
3597 Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
3598 }
3599
3600 // Operations on the Threads list for GC. These are not explicitly locked,
3601 // but the garbage collector must provide a safe context for them to run.
3602 // In particular, these things should never be called when the Threads_lock
3603 // is held by some other thread. (Note: the Safepoint abstraction also
3604 // uses the Threads_lock to guarantee this property. It also makes sure that
3605 // all threads gets blocked when exiting or starting).
3606
3607 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3608 ALL_JAVA_THREADS(p) {
3609 p->oops_do(f, cf);
3610 }
3611 VMThread::vm_thread()->oops_do(f, cf);
3612 }
3613
3614 void Threads::change_thread_claim_token() {
3615 if (++_thread_claim_token == 0) {
3616 // On overflow of the token counter, there is a risk of future
3617 // collisions between a new global token value and a stale token
3618 // for a thread, because not all iterations visit all threads.
3619 // (Though it's pretty much a theoretical concern for non-trivial
3620 // token counter sizes.) To deal with the possibility, reset all
3621 // the thread tokens to zero on global token overflow.
3622 struct ResetClaims : public ThreadClosure {
3623 virtual void do_thread(Thread* t) {
3624 t->claim_threads_do(false, 0);
3625 }
3626 } reset_claims;
3627 Threads::threads_do(&reset_claims);
3628 // On overflow, update the global token to non-zero, to
3629 // avoid the special "never claimed" initial thread value.
3630 _thread_claim_token = 1;
3631 }
3632 }
3633
3634 #ifdef ASSERT
3635 void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
3636 const uintx token = t->threads_do_token();
3637 assert(token == expected,
3638 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
3639 UINTX_FORMAT, kind, p2i(t), token, expected);
3640 }
3641
3642 void Threads::assert_all_threads_claimed() {
3643 ALL_JAVA_THREADS(p) {
3644 assert_thread_claimed("Thread", p, _thread_claim_token);
3645 }
3646 assert_thread_claimed("VMThread", VMThread::vm_thread(), _thread_claim_token);
3647 }
3648 #endif // ASSERT
3649
3650 class ParallelOopsDoThreadClosure : public ThreadClosure {
3651 private:
3652 OopClosure* _f;
3653 CodeBlobClosure* _cf;
3654 public:
3655 ParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf) : _f(f), _cf(cf) {}
3656 void do_thread(Thread* t) {
3657 t->oops_do(_f, _cf);
3658 }
3659 };
3660
3661 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) {
3662 ParallelOopsDoThreadClosure tc(f, cf);
3663 possibly_parallel_threads_do(is_par, &tc);
3664 }
3665
3666 void Threads::metadata_do(MetadataClosure* f) {
3667 ALL_JAVA_THREADS(p) {
3668 p->metadata_do(f);
3669 }
3670 }
3671
3672 class ThreadHandlesClosure : public ThreadClosure {
3673 void (*_f)(Metadata*);
3674 public:
3675 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
3676 virtual void do_thread(Thread* thread) {
3677 thread->metadata_handles_do(_f);
3678 }
3679 };
3680
3681 void Threads::metadata_handles_do(void f(Metadata*)) {
3682 // Only walk the Handles in Thread.
3683 ThreadHandlesClosure handles_closure(f);
3684 threads_do(&handles_closure);
3685 }
3686
3687 // Get count Java threads that are waiting to enter the specified monitor.
3688 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
3689 int count,
3690 address monitor) {
3691 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
3692
3693 int i = 0;
3694 DO_JAVA_THREADS(t_list, p) {
3695 if (!p->can_call_java()) continue;
3696
3697 // The first stage of async deflation does not affect any field
3698 // used by this comparison so the ObjectMonitor* is usable here.
3699 address pending = (address)p->current_pending_monitor();
3700 if (pending == monitor) { // found a match
3701 if (i < count) result->append(p); // save the first count matches
3702 i++;
3703 }
3704 }
3705
3706 return result;
3707 }
3708
3709
3710 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
3711 address owner) {
3712 // NULL owner means not locked so we can skip the search
3713 if (owner == NULL) return NULL;
3714
3715 DO_JAVA_THREADS(t_list, p) {
3716 // first, see if owner is the address of a Java thread
3717 if (owner == (address)p) return p;
3718 }
3719
3720 // Cannot assert on lack of success here since this function may be
3721 // used by code that is trying to report useful problem information
3722 // like deadlock detection.
3723 if (UseHeavyMonitors) return NULL;
3724
3725 // If we didn't find a matching Java thread and we didn't force use of
3726 // heavyweight monitors, then the owner is the stack address of the
3727 // Lock Word in the owning Java thread's stack.
3728 //
3729 JavaThread* the_owner = NULL;
3730 DO_JAVA_THREADS(t_list, q) {
3731 if (q->is_lock_owned(owner)) {
3732 the_owner = q;
3733 break;
3734 }
3735 }
3736
3737 // cannot assert on lack of success here; see above comment
3738 return the_owner;
3739 }
3740
3741 class PrintOnClosure : public ThreadClosure {
3742 private:
3743 outputStream* _st;
3744
3745 public:
3746 PrintOnClosure(outputStream* st) :
3747 _st(st) {}
3748
3749 virtual void do_thread(Thread* thread) {
3750 if (thread != NULL) {
3751 thread->print_on(_st);
3752 _st->cr();
3753 }
3754 }
3755 };
3756
3757 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
3758 void Threads::print_on(outputStream* st, bool print_stacks,
3759 bool internal_format, bool print_concurrent_locks,
3760 bool print_extended_info) {
3761 char buf[32];
3762 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
3763
3764 st->print_cr("Full thread dump %s (%s %s):",
3765 VM_Version::vm_name(),
3766 VM_Version::vm_release(),
3767 VM_Version::vm_info_string());
3768 st->cr();
3769
3770 #if INCLUDE_SERVICES
3771 // Dump concurrent locks
3772 ConcurrentLocksDump concurrent_locks;
3773 if (print_concurrent_locks) {
3774 concurrent_locks.dump_at_safepoint();
3775 }
3776 #endif // INCLUDE_SERVICES
3777
3778 ThreadsSMRSupport::print_info_on(st);
3779 st->cr();
3780
3781 ALL_JAVA_THREADS(p) {
3782 ResourceMark rm;
3783 p->print_on(st, print_extended_info);
3784 if (print_stacks) {
3785 if (internal_format) {
3786 p->trace_stack();
3787 } else {
3788 p->print_stack_on(st);
3789 }
3790 }
3791 st->cr();
3792 #if INCLUDE_SERVICES
3793 if (print_concurrent_locks) {
3794 concurrent_locks.print_locks_on(p, st);
3795 }
3796 #endif // INCLUDE_SERVICES
3797 }
3798
3799 PrintOnClosure cl(st);
3800 cl.do_thread(VMThread::vm_thread());
3801 Universe::heap()->gc_threads_do(&cl);
3802 if (StringDedup::is_enabled()) {
3803 StringDedup::threads_do(&cl);
3804 }
3805 cl.do_thread(WatcherThread::watcher_thread());
3806 cl.do_thread(AsyncLogWriter::instance());
3807
3808 st->flush();
3809 }
3810
3811 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
3812 int buflen, bool* found_current) {
3813 if (this_thread != NULL) {
3814 bool is_current = (current == this_thread);
3815 *found_current = *found_current || is_current;
3816 st->print("%s", is_current ? "=>" : " ");
3817
3818 st->print(PTR_FORMAT, p2i(this_thread));
3819 st->print(" ");
3820 this_thread->print_on_error(st, buf, buflen);
3821 st->cr();
3822 }
3823 }
3824
3825 class PrintOnErrorClosure : public ThreadClosure {
3826 outputStream* _st;
3827 Thread* _current;
3828 char* _buf;
3829 int _buflen;
3830 bool* _found_current;
3831 public:
3832 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
3833 int buflen, bool* found_current) :
3834 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
3835
3836 virtual void do_thread(Thread* thread) {
3837 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
3838 }
3839 };
3840
3841 // Threads::print_on_error() is called by fatal error handler. It's possible
3842 // that VM is not at safepoint and/or current thread is inside signal handler.
3843 // Don't print stack trace, as the stack may not be walkable. Don't allocate
3844 // memory (even in resource area), it might deadlock the error handler.
3845 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
3846 int buflen) {
3847 ThreadsSMRSupport::print_info_on(st);
3848 st->cr();
3849
3850 bool found_current = false;
3851 st->print_cr("Java Threads: ( => current thread )");
3852 ALL_JAVA_THREADS(thread) {
3853 print_on_error(thread, st, current, buf, buflen, &found_current);
3854 }
3855 st->cr();
3856
3857 st->print_cr("Other Threads:");
3858 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
3859 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
3860 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
3861
3862 if (Universe::heap() != NULL) {
3863 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
3864 Universe::heap()->gc_threads_do(&print_closure);
3865 }
3866
3867 if (StringDedup::is_enabled()) {
3868 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
3869 StringDedup::threads_do(&print_closure);
3870 }
3871
3872 if (!found_current) {
3873 st->cr();
3874 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
3875 current->print_on_error(st, buf, buflen);
3876 st->cr();
3877 }
3878 st->cr();
3879
3880 st->print_cr("Threads with active compile tasks:");
3881 print_threads_compiling(st, buf, buflen);
3882 }
3883
3884 void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
3885 ALL_JAVA_THREADS(thread) {
3886 if (thread->is_Compiler_thread()) {
3887 CompilerThread* ct = (CompilerThread*) thread;
3888
3889 // Keep task in local variable for NULL check.
3890 // ct->_task might be set to NULL by concurring compiler thread
3891 // because it completed the compilation. The task is never freed,
3892 // though, just returned to a free list.
3893 CompileTask* task = ct->task();
3894 if (task != NULL) {
3895 thread->print_name_on_error(st, buf, buflen);
3896 st->print(" ");
3897 task->print(st, NULL, short_form, true);
3898 }
3899 }
3900 }
3901 }
3902
3903
3904 // Ad-hoc mutual exclusion primitives: SpinLock
3905 //
3906 // We employ SpinLocks _only for low-contention, fixed-length
3907 // short-duration critical sections where we're concerned
3908 // about native mutex_t or HotSpot Mutex:: latency.
3909 //
3910 // TODO-FIXME: ListLock should be of type SpinLock.
3911 // We should make this a 1st-class type, integrated into the lock
3912 // hierarchy as leaf-locks. Critically, the SpinLock structure
3913 // should have sufficient padding to avoid false-sharing and excessive
3914 // cache-coherency traffic.
3915
3916
3917 typedef volatile int SpinLockT;
3918
3919 void Thread::SpinAcquire(volatile int * adr, const char * LockName) {
3920 if (Atomic::cmpxchg(adr, 0, 1) == 0) {
3921 return; // normal fast-path return
3922 }
3923
3924 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
3925 int ctr = 0;
3926 int Yields = 0;
3927 for (;;) {
3928 while (*adr != 0) {
3929 ++ctr;
3930 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
3931 if (Yields > 5) {
3932 os::naked_short_sleep(1);
3933 } else {
3934 os::naked_yield();
3935 ++Yields;
3936 }
3937 } else {
3938 SpinPause();
3939 }
3940 }
3941 if (Atomic::cmpxchg(adr, 0, 1) == 0) return;
3942 }
3943 }
3944
3945 void Thread::SpinRelease(volatile int * adr) {
3946 assert(*adr != 0, "invariant");
3947 OrderAccess::fence(); // guarantee at least release consistency.
3948 // Roach-motel semantics.
3949 // It's safe if subsequent LDs and STs float "up" into the critical section,
3950 // but prior LDs and STs within the critical section can't be allowed
3951 // to reorder or float past the ST that releases the lock.
3952 // Loads and stores in the critical section - which appear in program
3953 // order before the store that releases the lock - must also appear
3954 // before the store that releases the lock in memory visibility order.
3955 // Conceptually we need a #loadstore|#storestore "release" MEMBAR before
3956 // the ST of 0 into the lock-word which releases the lock, so fence
3957 // more than covers this on all platforms.
3958 *adr = 0;
3959 }
3960
3961
3962 void Threads::verify() {
3963 ALL_JAVA_THREADS(p) {
3964 p->verify();
3965 }
3966 VMThread* thread = VMThread::vm_thread();
3967 if (thread != NULL) thread->verify();
3968 }
3969
3970 #ifndef PRODUCT
3971 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
3972 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
3973 }
3974 #endif