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/lockStack.inline.hpp"
93 #include "runtime/monitorDeflationThread.hpp"
94 #include "runtime/mutexLocker.hpp"
95 #include "runtime/nonJavaThread.hpp"
96 #include "runtime/objectMonitor.inline.hpp"
97 #include "runtime/orderAccess.hpp"
98 #include "runtime/osThread.hpp"
99 #include "runtime/prefetch.inline.hpp"
100 #include "runtime/safepoint.hpp"
101 #include "runtime/safepointMechanism.inline.hpp"
102 #include "runtime/safepointVerifiers.hpp"
103 #include "runtime/serviceThread.hpp"
104 #include "runtime/sharedRuntime.hpp"
105 #include "runtime/stackFrameStream.inline.hpp"
106 #include "runtime/stackWatermarkSet.hpp"
107 #include "runtime/statSampler.hpp"
108 #include "runtime/task.hpp"
109 #include "runtime/thread.inline.hpp"
110 #include "runtime/threadCritical.hpp"
111 #include "runtime/threadSMR.inline.hpp"
112 #include "runtime/threadStatisticalInfo.hpp"
113 #include "runtime/threadWXSetters.inline.hpp"
114 #include "runtime/timer.hpp"
115 #include "runtime/timerTrace.hpp"
116 #include "runtime/vframe.inline.hpp"
117 #include "runtime/vframeArray.hpp"
118 #include "runtime/vframe_hp.hpp"
119 #include "runtime/vmThread.hpp"
120 #include "runtime/vmOperations.hpp"
121 #include "runtime/vm_version.hpp"
122 #include "services/attachListener.hpp"
123 #include "services/management.hpp"
124 #include "services/memTracker.hpp"
125 #include "services/threadService.hpp"
126 #include "utilities/align.hpp"
127 #include "utilities/copy.hpp"
128 #include "utilities/defaultStream.hpp"
129 #include "utilities/dtrace.hpp"
130 #include "utilities/events.hpp"
131 #include "utilities/macros.hpp"
132 #include "utilities/preserveException.hpp"
133 #include "utilities/spinYield.hpp"
134 #include "utilities/vmError.hpp"
135 #if INCLUDE_JVMCI
136 #include "jvmci/jvmci.hpp"
137 #include "jvmci/jvmciEnv.hpp"
138 #endif
139 #ifdef COMPILER1
140 #include "c1/c1_Compiler.hpp"
141 #endif
142 #ifdef COMPILER2
143 #include "opto/c2compiler.hpp"
144 #include "opto/idealGraphPrinter.hpp"
145 #endif
146 #if INCLUDE_RTM_OPT
147 #include "runtime/rtmLocking.hpp"
148 #endif
149 #if INCLUDE_JFR
150 #include "jfr/jfr.hpp"
151 #endif
152
153 // Initialization after module runtime initialization
154 void universe_post_module_init(); // must happen after call_initPhase2
155
156 #ifdef DTRACE_ENABLED
157
158 // Only bother with this argument setup if dtrace is available
159
160 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
161 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
162
163 #define DTRACE_THREAD_PROBE(probe, javathread) \
164 { \
165 ResourceMark rm(this); \
166 int len = 0; \
167 const char* name = (javathread)->get_thread_name(); \
168 len = strlen(name); \
169 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
170 (char *) name, len, \
171 java_lang_Thread::thread_id((javathread)->threadObj()), \
172 (uintptr_t) (javathread)->osthread()->thread_id(), \
173 java_lang_Thread::is_daemon((javathread)->threadObj())); \
174 }
175
176 #else // ndef DTRACE_ENABLED
177
178 #define DTRACE_THREAD_PROBE(probe, javathread)
179
180 #endif // ndef DTRACE_ENABLED
181
182 #ifndef USE_LIBRARY_BASED_TLS_ONLY
183 // Current thread is maintained as a thread-local variable
184 THREAD_LOCAL Thread* Thread::_thr_current = NULL;
185 #endif
186
187 // ======= Thread ========
188 // Support for forcing alignment of thread objects for biased locking
189 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
190 if (UseBiasedLocking) {
191 const size_t alignment = markWord::biased_lock_alignment;
192 size_t aligned_size = size + (alignment - sizeof(intptr_t));
193 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
194 : AllocateHeap(aligned_size, flags, CURRENT_PC,
195 AllocFailStrategy::RETURN_NULL);
196 void* aligned_addr = align_up(real_malloc_addr, alignment);
197 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
198 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
199 "JavaThread alignment code overflowed allocated storage");
200 if (aligned_addr != real_malloc_addr) {
201 log_info(biasedlocking)("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
202 p2i(real_malloc_addr),
203 p2i(aligned_addr));
204 }
205 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
206 return aligned_addr;
207 } else {
208 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
209 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
210 }
211 }
212
213 void Thread::operator delete(void* p) {
214 if (UseBiasedLocking) {
215 FreeHeap(((Thread*) p)->_real_malloc_address);
216 } else {
217 FreeHeap(p);
218 }
219 }
220
221 void JavaThread::smr_delete() {
222 if (_on_thread_list) {
223 ThreadsSMRSupport::smr_delete(this);
224 } else {
225 delete this;
226 }
227 }
228
229 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
230 // JavaThread
231
232 DEBUG_ONLY(Thread* Thread::_starting_thread = NULL;)
233
234 Thread::Thread() {
235
236 DEBUG_ONLY(_run_state = PRE_CALL_RUN;)
237
238 // stack and get_thread
239 set_stack_base(NULL);
240 set_stack_size(0);
241 set_lgrp_id(-1);
242 DEBUG_ONLY(clear_suspendible_thread();)
243
244 // allocated data structures
245 set_osthread(NULL);
246 set_resource_area(new (mtThread)ResourceArea());
247 DEBUG_ONLY(_current_resource_mark = NULL;)
248 set_handle_area(new (mtThread) HandleArea(NULL));
249 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, mtClass));
250 set_active_handles(NULL);
251 set_free_handle_block(NULL);
252 set_last_handle_mark(NULL);
253 DEBUG_ONLY(_missed_ic_stub_refill_verifier = NULL);
254
255 // Initial value of zero ==> never claimed.
256 _threads_do_token = 0;
257 _threads_hazard_ptr = NULL;
258 _threads_list_ptr = NULL;
259 _nested_threads_hazard_ptr_cnt = 0;
260 _rcu_counter = 0;
261
262 // the handle mark links itself to last_handle_mark
263 new HandleMark(this);
264
265 // plain initialization
266 debug_only(_owned_locks = NULL;)
267 NOT_PRODUCT(_skip_gcalot = false;)
268 _jvmti_env_iteration_count = 0;
269 set_allocated_bytes(0);
270 _current_pending_raw_monitor = NULL;
271
272 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
273 _hashStateX = os::random();
274 _hashStateY = 842502087;
275 _hashStateZ = 0x8767; // (int)(3579807591LL & 0xffff) ;
276 _hashStateW = 273326509;
277
278 // Many of the following fields are effectively final - immutable
279 // Note that nascent threads can't use the Native Monitor-Mutex
280 // construct until the _MutexEvent is initialized ...
281 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
282 // we might instead use a stack of ParkEvents that we could provision on-demand.
283 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
284 // and ::Release()
285 _ParkEvent = ParkEvent::Allocate(this);
286
287 #ifdef CHECK_UNHANDLED_OOPS
288 if (CheckUnhandledOops) {
289 _unhandled_oops = new UnhandledOops(this);
290 }
291 #endif // CHECK_UNHANDLED_OOPS
292 #ifdef ASSERT
293 if (UseBiasedLocking) {
294 assert(is_aligned(this, markWord::biased_lock_alignment), "forced alignment of thread object failed");
295 assert(this == _real_malloc_address ||
296 this == align_up(_real_malloc_address, markWord::biased_lock_alignment),
297 "bug in forced alignment of thread objects");
298 }
299 #endif // ASSERT
300
301 // Notify the barrier set that a thread is being created. The initial
302 // thread is created before the barrier set is available. The call to
303 // BarrierSet::on_thread_create() for this thread is therefore deferred
304 // to BarrierSet::set_barrier_set().
305 BarrierSet* const barrier_set = BarrierSet::barrier_set();
306 if (barrier_set != NULL) {
307 barrier_set->on_thread_create(this);
308 } else {
309 // Only the main thread should be created before the barrier set
310 // and that happens just before Thread::current is set. No other thread
311 // can attach as the VM is not created yet, so they can't execute this code.
312 // If the main thread creates other threads before the barrier set that is an error.
313 assert(Thread::current_or_null() == NULL, "creating thread before barrier set");
314 }
315
316 MACOS_AARCH64_ONLY(DEBUG_ONLY(_wx_init = false));
317 }
318
319 void Thread::initialize_tlab() {
320 if (UseTLAB) {
321 tlab().initialize();
322 }
323 }
324
325 void Thread::initialize_thread_current() {
326 #ifndef USE_LIBRARY_BASED_TLS_ONLY
327 assert(_thr_current == NULL, "Thread::current already initialized");
328 _thr_current = this;
329 #endif
330 assert(ThreadLocalStorage::thread() == NULL, "ThreadLocalStorage::thread already initialized");
331 ThreadLocalStorage::set_thread(this);
332 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
333 }
334
335 void Thread::clear_thread_current() {
336 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
337 #ifndef USE_LIBRARY_BASED_TLS_ONLY
338 _thr_current = NULL;
339 #endif
340 ThreadLocalStorage::set_thread(NULL);
341 }
342
343 void Thread::record_stack_base_and_size() {
344 // Note: at this point, Thread object is not yet initialized. Do not rely on
345 // any members being initialized. Do not rely on Thread::current() being set.
346 // If possible, refrain from doing anything which may crash or assert since
347 // quite probably those crash dumps will be useless.
348 set_stack_base(os::current_stack_base());
349 set_stack_size(os::current_stack_size());
350
351 // Set stack limits after thread is initialized.
352 if (is_Java_thread()) {
353 as_Java_thread()->stack_overflow_state()->initialize(stack_base(), stack_end());
354 }
355 }
356
357 #if INCLUDE_NMT
358 void Thread::register_thread_stack_with_NMT() {
359 MemTracker::record_thread_stack(stack_end(), stack_size());
360 }
361
362 void Thread::unregister_thread_stack_with_NMT() {
363 MemTracker::release_thread_stack(stack_end(), stack_size());
364 }
365 #endif // INCLUDE_NMT
366
367 void Thread::call_run() {
368 DEBUG_ONLY(_run_state = CALL_RUN;)
369
370 // At this point, Thread object should be fully initialized and
371 // Thread::current() should be set.
372
373 assert(Thread::current_or_null() != NULL, "current thread is unset");
374 assert(Thread::current_or_null() == this, "current thread is wrong");
375
376 // Perform common initialization actions
377
378 MACOS_AARCH64_ONLY(this->init_wx());
379
380 register_thread_stack_with_NMT();
381
382 JFR_ONLY(Jfr::on_thread_start(this);)
383
384 log_debug(os, thread)("Thread " UINTX_FORMAT " stack dimensions: "
385 PTR_FORMAT "-" PTR_FORMAT " (" SIZE_FORMAT "k).",
386 os::current_thread_id(), p2i(stack_end()),
387 p2i(stack_base()), stack_size()/1024);
388
389 // Perform <ChildClass> initialization actions
390 DEBUG_ONLY(_run_state = PRE_RUN;)
391 this->pre_run();
392
393 // Invoke <ChildClass>::run()
394 DEBUG_ONLY(_run_state = RUN;)
395 this->run();
396 // Returned from <ChildClass>::run(). Thread finished.
397
398 // Perform common tear-down actions
399
400 assert(Thread::current_or_null() != NULL, "current thread is unset");
401 assert(Thread::current_or_null() == this, "current thread is wrong");
402
403 // Perform <ChildClass> tear-down actions
404 DEBUG_ONLY(_run_state = POST_RUN;)
405 this->post_run();
406
407 // Note: at this point the thread object may already have deleted itself,
408 // so from here on do not dereference *this*. Not all thread types currently
409 // delete themselves when they terminate. But no thread should ever be deleted
410 // asynchronously with respect to its termination - that is what _run_state can
411 // be used to check.
412
413 assert(Thread::current_or_null() == NULL, "current thread still present");
414 }
415
416 Thread::~Thread() {
417
418 // Attached threads will remain in PRE_CALL_RUN, as will threads that don't actually
419 // get started due to errors etc. Any active thread should at least reach post_run
420 // before it is deleted (usually in post_run()).
421 assert(_run_state == PRE_CALL_RUN ||
422 _run_state == POST_RUN, "Active Thread deleted before post_run(): "
423 "_run_state=%d", (int)_run_state);
424
425 // Notify the barrier set that a thread is being destroyed. Note that a barrier
426 // set might not be available if we encountered errors during bootstrapping.
427 BarrierSet* const barrier_set = BarrierSet::barrier_set();
428 if (barrier_set != NULL) {
429 barrier_set->on_thread_destroy(this);
430 }
431
432 // deallocate data structures
433 delete resource_area();
434 // since the handle marks are using the handle area, we have to deallocated the root
435 // handle mark before deallocating the thread's handle area,
436 assert(last_handle_mark() != NULL, "check we have an element");
437 delete last_handle_mark();
438 assert(last_handle_mark() == NULL, "check we have reached the end");
439
440 ParkEvent::Release(_ParkEvent);
441 // Set to NULL as a termination indicator for has_terminated().
442 Atomic::store(&_ParkEvent, (ParkEvent*)NULL);
443
444 delete handle_area();
445 delete metadata_handles();
446
447 // osthread() can be NULL, if creation of thread failed.
448 if (osthread() != NULL) os::free_thread(osthread());
449
450 // Clear Thread::current if thread is deleting itself and it has not
451 // already been done. This must be done before the memory is deallocated.
452 // Needed to ensure JNI correctly detects non-attached threads.
453 if (this == Thread::current_or_null()) {
454 Thread::clear_thread_current();
455 }
456
457 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
458 }
459
460 #ifdef ASSERT
461 // A JavaThread is considered dangling if it not handshake-safe with respect to
462 // the current thread, it is not on a ThreadsList, or not at safepoint.
463 void Thread::check_for_dangling_thread_pointer(Thread *thread) {
464 assert(!thread->is_Java_thread() ||
465 thread->as_Java_thread()->is_handshake_safe_for(Thread::current()) ||
466 !thread->as_Java_thread()->on_thread_list() ||
467 SafepointSynchronize::is_at_safepoint() ||
468 ThreadsSMRSupport::is_a_protected_JavaThread_with_lock(thread->as_Java_thread()),
469 "possibility of dangling Thread pointer");
470 }
471 #endif
472
473 // Is the target JavaThread protected by the calling Thread
474 // or by some other mechanism:
475 bool Thread::is_JavaThread_protected(const JavaThread* p) {
476 // Do the simplest check first:
477 if (SafepointSynchronize::is_at_safepoint()) {
478 // The target is protected since JavaThreads cannot exit
479 // while we're at a safepoint.
480 return true;
481 }
482
483 // If the target hasn't been started yet then it is trivially
484 // "protected". We assume the caller is the thread that will do
485 // the starting.
486 if (p->osthread() == NULL || p->osthread()->get_state() <= INITIALIZED) {
487 return true;
488 }
489
490 // Now make the simple checks based on who the caller is:
491 Thread* current_thread = Thread::current();
492 if (current_thread == p || Threads_lock->owner() == current_thread) {
493 // Target JavaThread is self or calling thread owns the Threads_lock.
494 // Second check is the same as Threads_lock->owner_is_self(),
495 // but we already have the current thread so check directly.
496 return true;
497 }
498
499 // Check the ThreadsLists associated with the calling thread (if any)
500 // to see if one of them protects the target JavaThread:
501 for (SafeThreadsListPtr* stlp = current_thread->_threads_list_ptr;
502 stlp != NULL; stlp = stlp->previous()) {
503 if (stlp->list()->includes(p)) {
504 // The target JavaThread is protected by this ThreadsList:
505 return true;
506 }
507 }
508
509 // Use this debug code with -XX:+UseNewCode to diagnose locations that
510 // are missing a ThreadsListHandle or other protection mechanism:
511 // guarantee(!UseNewCode, "current_thread=" INTPTR_FORMAT " is not protecting p="
512 // INTPTR_FORMAT, p2i(current_thread), p2i(p));
513
514 // Note: Since 'p' isn't protected by a TLH, the call to
515 // p->is_handshake_safe_for() may crash, but we have debug bits so
516 // we'll be able to figure out what protection mechanism is missing.
517 assert(p->is_handshake_safe_for(current_thread), "JavaThread=" INTPTR_FORMAT
518 " is not protected and not handshake safe.", p2i(p));
519
520 // The target JavaThread is not protected so it is not safe to query:
521 return false;
522 }
523
524 ThreadPriority Thread::get_priority(const Thread* const thread) {
525 ThreadPriority priority;
526 // Can return an error!
527 (void)os::get_priority(thread, priority);
528 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
529 return priority;
530 }
531
532 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
533 debug_only(check_for_dangling_thread_pointer(thread);)
534 // Can return an error!
535 (void)os::set_priority(thread, priority);
536 }
537
538
539 void Thread::start(Thread* thread) {
540 // Start is different from resume in that its safety is guaranteed by context or
541 // being called from a Java method synchronized on the Thread object.
542 if (thread->is_Java_thread()) {
543 // Initialize the thread state to RUNNABLE before starting this thread.
544 // Can not set it after the thread started because we do not know the
545 // exact thread state at that time. It could be in MONITOR_WAIT or
546 // in SLEEPING or some other state.
547 java_lang_Thread::set_thread_status(thread->as_Java_thread()->threadObj(),
548 JavaThreadStatus::RUNNABLE);
549 }
550 os::start_thread(thread);
551 }
552
553 // GC Support
554 bool Thread::claim_par_threads_do(uintx claim_token) {
555 uintx token = _threads_do_token;
556 if (token != claim_token) {
557 uintx res = Atomic::cmpxchg(&_threads_do_token, token, claim_token);
558 if (res == token) {
559 return true;
560 }
561 guarantee(res == claim_token, "invariant");
562 }
563 return false;
564 }
565
566 void Thread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
567 if (active_handles() != NULL) {
568 active_handles()->oops_do(f);
569 }
570 // Do oop for ThreadShadow
571 f->do_oop((oop*)&_pending_exception);
572 handle_area()->oops_do(f);
573 }
574
575 // If the caller is a NamedThread, then remember, in the current scope,
576 // the given JavaThread in its _processed_thread field.
577 class RememberProcessedThread: public StackObj {
578 NamedThread* _cur_thr;
579 public:
580 RememberProcessedThread(Thread* thread) {
581 Thread* self = Thread::current();
582 if (self->is_Named_thread()) {
583 _cur_thr = (NamedThread *)self;
584 assert(_cur_thr->processed_thread() == NULL, "nesting not supported");
585 _cur_thr->set_processed_thread(thread);
586 } else {
587 _cur_thr = NULL;
588 }
589 }
590
591 ~RememberProcessedThread() {
592 if (_cur_thr) {
593 assert(_cur_thr->processed_thread() != NULL, "nesting not supported");
594 _cur_thr->set_processed_thread(NULL);
595 }
596 }
597 };
598
599 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
600 // Record JavaThread to GC thread
601 RememberProcessedThread rpt(this);
602 oops_do_no_frames(f, cf);
603 oops_do_frames(f, cf);
604 }
605
606 void Thread::metadata_handles_do(void f(Metadata*)) {
607 // Only walk the Handles in Thread.
608 if (metadata_handles() != NULL) {
609 for (int i = 0; i< metadata_handles()->length(); i++) {
610 f(metadata_handles()->at(i));
611 }
612 }
613 }
614
615 void Thread::print_on(outputStream* st, bool print_extended_info) const {
616 // get_priority assumes osthread initialized
617 if (osthread() != NULL) {
618 int os_prio;
619 if (os::get_native_priority(this, &os_prio) == OS_OK) {
620 st->print("os_prio=%d ", os_prio);
621 }
622
623 st->print("cpu=%.2fms ",
624 os::thread_cpu_time(const_cast<Thread*>(this), true) / 1000000.0
625 );
626 st->print("elapsed=%.2fs ",
627 _statistical_info.getElapsedTime() / 1000.0
628 );
629 if (is_Java_thread() && (PrintExtendedThreadInfo || print_extended_info)) {
630 size_t allocated_bytes = (size_t) const_cast<Thread*>(this)->cooked_allocated_bytes();
631 st->print("allocated=" SIZE_FORMAT "%s ",
632 byte_size_in_proper_unit(allocated_bytes),
633 proper_unit_for_byte_size(allocated_bytes)
634 );
635 st->print("defined_classes=" INT64_FORMAT " ", _statistical_info.getDefineClassCount());
636 }
637
638 st->print("tid=" INTPTR_FORMAT " ", p2i(this));
639 osthread()->print_on(st);
640 }
641 ThreadsSMRSupport::print_info_on(this, st);
642 st->print(" ");
643 debug_only(if (WizardMode) print_owned_locks_on(st);)
644 }
645
646 void Thread::print() const { print_on(tty); }
647
648 // Thread::print_on_error() is called by fatal error handler. Don't use
649 // any lock or allocate memory.
650 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
651 assert(!(is_Compiler_thread() || is_Java_thread()), "Can't call name() here if it allocates");
652
653 if (is_VM_thread()) { st->print("VMThread"); }
654 else if (is_GC_task_thread()) { st->print("GCTaskThread"); }
655 else if (is_Watcher_thread()) { st->print("WatcherThread"); }
656 else if (is_ConcurrentGC_thread()) { st->print("ConcurrentGCThread"); }
657 else { st->print("Thread"); }
658
659 if (is_Named_thread()) {
660 st->print(" \"%s\"", name());
661 }
662
663 OSThread* os_thr = osthread();
664 if (os_thr != NULL) {
665 if (os_thr->get_state() != ZOMBIE) {
666 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
667 p2i(stack_end()), p2i(stack_base()));
668 st->print(" [id=%d]", osthread()->thread_id());
669 } else {
670 st->print(" terminated");
671 }
672 } else {
673 st->print(" unknown state (no osThread)");
674 }
675 ThreadsSMRSupport::print_info_on(this, st);
676 }
677
678 void Thread::print_value_on(outputStream* st) const {
679 if (is_Named_thread()) {
680 st->print(" \"%s\" ", name());
681 }
682 st->print(INTPTR_FORMAT, p2i(this)); // print address
683 }
684
685 #ifdef ASSERT
686 void Thread::print_owned_locks_on(outputStream* st) const {
687 Mutex* cur = _owned_locks;
688 if (cur == NULL) {
689 st->print(" (no locks) ");
690 } else {
691 st->print_cr(" Locks owned:");
692 while (cur) {
693 cur->print_on(st);
694 cur = cur->next();
695 }
696 }
697 }
698 #endif // ASSERT
699
700 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
701 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
702 // used for compilation in the future. If that change is made, the need for these methods
703 // should be revisited, and they should be removed if possible.
704
705 bool Thread::is_lock_owned(address adr) const {
706 assert(!UseFastLocking, "maybe not call that?");
707 return is_in_full_stack(adr);
708 }
709
710 bool Thread::set_as_starting_thread() {
711 assert(_starting_thread == NULL, "already initialized: "
712 "_starting_thread=" INTPTR_FORMAT, p2i(_starting_thread));
713 // NOTE: this must be called inside the main thread.
714 DEBUG_ONLY(_starting_thread = this;)
715 return os::create_main_thread(this->as_Java_thread());
716 }
717
718 static void initialize_class(Symbol* class_name, TRAPS) {
719 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
720 InstanceKlass::cast(klass)->initialize(CHECK);
721 }
722
723
724 // Creates the initial ThreadGroup
725 static Handle create_initial_thread_group(TRAPS) {
726 Handle system_instance = JavaCalls::construct_new_instance(
727 vmClasses::ThreadGroup_klass(),
728 vmSymbols::void_method_signature(),
729 CHECK_NH);
730 Universe::set_system_thread_group(system_instance());
731
732 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
733 Handle main_instance = JavaCalls::construct_new_instance(
734 vmClasses::ThreadGroup_klass(),
735 vmSymbols::threadgroup_string_void_signature(),
736 system_instance,
737 string,
738 CHECK_NH);
739 return main_instance;
740 }
741
742 // Creates the initial Thread, and sets it to running.
743 static void create_initial_thread(Handle thread_group, JavaThread* thread,
744 TRAPS) {
745 InstanceKlass* ik = vmClasses::Thread_klass();
746 assert(ik->is_initialized(), "must be");
747 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
748
749 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
750 // constructor calls Thread.current(), which must be set here for the
751 // initial thread.
752 java_lang_Thread::set_thread(thread_oop(), thread);
753 java_lang_Thread::set_priority(thread_oop(), NormPriority);
754 thread->set_threadObj(thread_oop());
755
756 Handle string = java_lang_String::create_from_str("main", CHECK);
757
758 JavaValue result(T_VOID);
759 JavaCalls::call_special(&result, thread_oop,
760 ik,
761 vmSymbols::object_initializer_name(),
762 vmSymbols::threadgroup_string_void_signature(),
763 thread_group,
764 string,
765 CHECK);
766
767 // Set thread status to running since main thread has
768 // been started and running.
769 java_lang_Thread::set_thread_status(thread_oop(),
770 JavaThreadStatus::RUNNABLE);
771 }
772
773 // Extract version and vendor specific information from
774 // java.lang.VersionProps fields.
775 // Returned char* is allocated in the thread's resource area
776 // so must be copied for permanency.
777 static const char* get_java_version_info(InstanceKlass* ik,
778 Symbol* field_name) {
779 fieldDescriptor fd;
780 bool found = ik != NULL &&
781 ik->find_local_field(field_name,
782 vmSymbols::string_signature(), &fd);
783 if (found) {
784 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
785 if (name_oop == NULL) {
786 return NULL;
787 }
788 const char* name = java_lang_String::as_utf8_string(name_oop);
789 return name;
790 } else {
791 return NULL;
792 }
793 }
794
795 // General purpose hook into Java code, run once when the VM is initialized.
796 // The Java library method itself may be changed independently from the VM.
797 static void call_postVMInitHook(TRAPS) {
798 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
799 if (klass != NULL) {
800 JavaValue result(T_VOID);
801 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
802 vmSymbols::void_method_signature(),
803 CHECK);
804 }
805 }
806
807 // Initialized by VMThread at vm_global_init
808 static OopStorage* _thread_oop_storage = NULL;
809
810 oop JavaThread::threadObj() const {
811 return _threadObj.resolve();
812 }
813
814 void JavaThread::set_threadObj(oop p) {
815 assert(_thread_oop_storage != NULL, "not yet initialized");
816 _threadObj = OopHandle(_thread_oop_storage, p);
817 }
818
819 OopStorage* JavaThread::thread_oop_storage() {
820 assert(_thread_oop_storage != NULL, "not yet initialized");
821 return _thread_oop_storage;
822 }
823
824 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
825 bool daemon, TRAPS) {
826 assert(thread_group.not_null(), "thread group should be specified");
827 assert(threadObj() == NULL, "should only create Java thread object once");
828
829 InstanceKlass* ik = vmClasses::Thread_klass();
830 assert(ik->is_initialized(), "must be");
831 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
832
833 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
834 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
835 // constructor calls Thread.current(), which must be set here.
836 java_lang_Thread::set_thread(thread_oop(), this);
837 java_lang_Thread::set_priority(thread_oop(), NormPriority);
838 set_threadObj(thread_oop());
839
840 JavaValue result(T_VOID);
841 if (thread_name != NULL) {
842 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
843 // Thread gets assigned specified name and null target
844 JavaCalls::call_special(&result,
845 thread_oop,
846 ik,
847 vmSymbols::object_initializer_name(),
848 vmSymbols::threadgroup_string_void_signature(),
849 thread_group,
850 name,
851 THREAD);
852 } else {
853 // Thread gets assigned name "Thread-nnn" and null target
854 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
855 JavaCalls::call_special(&result,
856 thread_oop,
857 ik,
858 vmSymbols::object_initializer_name(),
859 vmSymbols::threadgroup_runnable_void_signature(),
860 thread_group,
861 Handle(),
862 THREAD);
863 }
864
865
866 if (daemon) {
867 java_lang_Thread::set_daemon(thread_oop());
868 }
869
870 if (HAS_PENDING_EXCEPTION) {
871 return;
872 }
873
874 Klass* group = vmClasses::ThreadGroup_klass();
875 Handle threadObj(THREAD, this->threadObj());
876
877 JavaCalls::call_special(&result,
878 thread_group,
879 group,
880 vmSymbols::add_method_name(),
881 vmSymbols::thread_void_signature(),
882 threadObj, // Arg 1
883 THREAD);
884 }
885
886 // ======= JavaThread ========
887
888 #if INCLUDE_JVMCI
889
890 jlong* JavaThread::_jvmci_old_thread_counters;
891
892 bool jvmci_counters_include(JavaThread* thread) {
893 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
894 }
895
896 void JavaThread::collect_counters(jlong* array, int length) {
897 assert(length == JVMCICounterSize, "wrong value");
898 for (int i = 0; i < length; i++) {
899 array[i] = _jvmci_old_thread_counters[i];
900 }
901 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *tp = jtiwh.next(); ) {
902 if (jvmci_counters_include(tp)) {
903 for (int i = 0; i < length; i++) {
904 array[i] += tp->_jvmci_counters[i];
905 }
906 }
907 }
908 }
909
910 // Attempt to enlarge the array for per thread counters.
911 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
912 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
913 if (new_counters == NULL) {
914 return NULL;
915 }
916 if (old_counters == NULL) {
917 old_counters = new_counters;
918 memset(old_counters, 0, sizeof(jlong) * new_size);
919 } else {
920 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
921 new_counters[i] = old_counters[i];
922 }
923 if (new_size > current_size) {
924 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
925 }
926 FREE_C_HEAP_ARRAY(jlong, old_counters);
927 }
928 return new_counters;
929 }
930
931 // Attempt to enlarge the array for per thread counters.
932 bool JavaThread::resize_counters(int current_size, int new_size) {
933 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
934 if (new_counters == NULL) {
935 return false;
936 } else {
937 _jvmci_counters = new_counters;
938 return true;
939 }
940 }
941
942 class VM_JVMCIResizeCounters : public VM_Operation {
943 private:
944 int _new_size;
945 bool _failed;
946
947 public:
948 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
949 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
950 bool allow_nested_vm_operations() const { return true; }
951 void doit() {
952 // Resize the old thread counters array
953 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
954 if (new_counters == NULL) {
955 _failed = true;
956 return;
957 } else {
958 JavaThread::_jvmci_old_thread_counters = new_counters;
959 }
960
961 // Now resize each threads array
962 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *tp = jtiwh.next(); ) {
963 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
964 _failed = true;
965 break;
966 }
967 }
968 if (!_failed) {
969 JVMCICounterSize = _new_size;
970 }
971 }
972
973 bool failed() { return _failed; }
974 };
975
976 bool JavaThread::resize_all_jvmci_counters(int new_size) {
977 VM_JVMCIResizeCounters op(new_size);
978 VMThread::execute(&op);
979 return !op.failed();
980 }
981
982 #endif // INCLUDE_JVMCI
983
984 #ifdef ASSERT
985 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
986 void JavaThread::check_possible_safepoint() {
987 if (_no_safepoint_count > 0) {
988 print_owned_locks();
989 assert(false, "Possible safepoint reached by thread that does not allow it");
990 }
991 #ifdef CHECK_UNHANDLED_OOPS
992 // Clear unhandled oops in JavaThreads so we get a crash right away.
993 clear_unhandled_oops();
994 #endif // CHECK_UNHANDLED_OOPS
995 }
996
997 void JavaThread::check_for_valid_safepoint_state() {
998 // Check NoSafepointVerifier, which is implied by locks taken that can be
999 // shared with the VM thread. This makes sure that no locks with allow_vm_block
1000 // are held.
1001 check_possible_safepoint();
1002
1003 if (thread_state() != _thread_in_vm) {
1004 fatal("LEAF method calling lock?");
1005 }
1006
1007 if (GCALotAtAllSafepoints) {
1008 // We could enter a safepoint here and thus have a gc
1009 InterfaceSupport::check_gc_alot();
1010 }
1011 }
1012 #endif // ASSERT
1013
1014 // A JavaThread is a normal Java thread
1015
1016 JavaThread::JavaThread() :
1017 // Initialize fields
1018
1019 _in_asgct(false),
1020 _on_thread_list(false),
1021 DEBUG_ONLY(_java_call_counter(0) COMMA)
1022 _entry_point(nullptr),
1023 _deopt_mark(nullptr),
1024 _deopt_nmethod(nullptr),
1025 _vframe_array_head(nullptr),
1026 _vframe_array_last(nullptr),
1027 _jvmti_deferred_updates(nullptr),
1028 _callee_target(nullptr),
1029 _vm_result(nullptr),
1030 _vm_result_2(nullptr),
1031
1032 _current_pending_monitor(NULL),
1033 _current_pending_monitor_is_from_java(true),
1034 _current_waiting_monitor(NULL),
1035 _Stalled(0),
1036
1037 _monitor_chunks(nullptr),
1038
1039 _suspend_flags(0),
1040 _async_exception_condition(_no_async_condition),
1041 _pending_async_exception(nullptr),
1042
1043 _thread_state(_thread_new),
1044 _saved_exception_pc(nullptr),
1045 #ifdef ASSERT
1046 _no_safepoint_count(0),
1047 _visited_for_critical_count(false),
1048 #endif
1049
1050 _terminated(_not_terminated),
1051 _in_deopt_handler(0),
1052 _doing_unsafe_access(false),
1053 _do_not_unlock_if_synchronized(false),
1054 _jni_attach_state(_not_attaching_via_jni),
1055 #if INCLUDE_JVMCI
1056 _pending_deoptimization(-1),
1057 _pending_monitorenter(false),
1058 _pending_transfer_to_interpreter(false),
1059 _in_retryable_allocation(false),
1060 _pending_failed_speculation(0),
1061 _jvmci{nullptr},
1062 _jvmci_counters(nullptr),
1063 _jvmci_reserved0(0),
1064 _jvmci_reserved1(0),
1065 _jvmci_reserved_oop0(nullptr),
1066 #endif // INCLUDE_JVMCI
1067
1068 _exception_oop(oop()),
1069 _exception_pc(0),
1070 _exception_handler_pc(0),
1071 _is_method_handle_return(0),
1072
1073 _jni_active_critical(0),
1074 _pending_jni_exception_check_fn(nullptr),
1075 _depth_first_number(0),
1076
1077 // JVMTI PopFrame support
1078 _popframe_condition(popframe_inactive),
1079 _frames_to_pop_failed_realloc(0),
1080
1081 _handshake(this),
1082
1083 _popframe_preserved_args(nullptr),
1084 _popframe_preserved_args_size(0),
1085
1086 _jvmti_thread_state(nullptr),
1087 _interp_only_mode(0),
1088 _should_post_on_exceptions_flag(JNI_FALSE),
1089 _thread_stat(new ThreadStatistics()),
1090
1091 _parker(),
1092 _cached_monitor_info(nullptr),
1093
1094 _class_to_be_initialized(nullptr),
1095
1096 _SleepEvent(ParkEvent::Allocate(this)),
1097 _lock_stack()
1098 {
1099 set_jni_functions(jni_functions());
1100
1101 #if INCLUDE_JVMCI
1102 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
1103 if (JVMCICounterSize > 0) {
1104 resize_counters(0, (int) JVMCICounterSize);
1105 }
1106 #endif // INCLUDE_JVMCI
1107
1108 // Setup safepoint state info for this thread
1109 ThreadSafepointState::create(this);
1110
1111 SafepointMechanism::initialize_header(this);
1112
1113 set_requires_cross_modify_fence(false);
1114
1115 pd_initialize();
1116 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
1117 }
1118
1119 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
1120 if (is_attaching_via_jni) {
1121 _jni_attach_state = _attaching_via_jni;
1122 }
1123 }
1124
1125
1126 // interrupt support
1127
1128 void JavaThread::interrupt() {
1129 // All callers should have 'this' thread protected by a
1130 // ThreadsListHandle so that it cannot terminate and deallocate
1131 // itself.
1132 debug_only(check_for_dangling_thread_pointer(this);)
1133
1134 // For Windows _interrupt_event
1135 osthread()->set_interrupted(true);
1136
1137 // For Thread.sleep
1138 _SleepEvent->unpark();
1139
1140 // For JSR166 LockSupport.park
1141 parker()->unpark();
1142
1143 // For ObjectMonitor and JvmtiRawMonitor
1144 _ParkEvent->unpark();
1145 }
1146
1147
1148 bool JavaThread::is_interrupted(bool clear_interrupted) {
1149 debug_only(check_for_dangling_thread_pointer(this);)
1150
1151 if (_threadObj.peek() == NULL) {
1152 // If there is no j.l.Thread then it is impossible to have
1153 // been interrupted. We can find NULL during VM initialization
1154 // or when a JNI thread is still in the process of attaching.
1155 // In such cases this must be the current thread.
1156 assert(this == Thread::current(), "invariant");
1157 return false;
1158 }
1159
1160 bool interrupted = java_lang_Thread::interrupted(threadObj());
1161
1162 // NOTE that since there is no "lock" around the interrupt and
1163 // is_interrupted operations, there is the possibility that the
1164 // interrupted flag will be "false" but that the
1165 // low-level events will be in the signaled state. This is
1166 // intentional. The effect of this is that Object.wait() and
1167 // LockSupport.park() will appear to have a spurious wakeup, which
1168 // is allowed and not harmful, and the possibility is so rare that
1169 // it is not worth the added complexity to add yet another lock.
1170 // For the sleep event an explicit reset is performed on entry
1171 // to JavaThread::sleep, so there is no early return. It has also been
1172 // recommended not to put the interrupted flag into the "event"
1173 // structure because it hides the issue.
1174 // Also, because there is no lock, we must only clear the interrupt
1175 // state if we are going to report that we were interrupted; otherwise
1176 // an interrupt that happens just after we read the field would be lost.
1177 if (interrupted && clear_interrupted) {
1178 assert(this == Thread::current(), "only the current thread can clear");
1179 java_lang_Thread::set_interrupted(threadObj(), false);
1180 osthread()->set_interrupted(false);
1181 }
1182
1183 return interrupted;
1184 }
1185
1186 void JavaThread::block_if_vm_exited() {
1187 if (_terminated == _vm_exited) {
1188 // _vm_exited is set at safepoint, and Threads_lock is never released
1189 // we will block here forever.
1190 // Here we can be doing a jump from a safe state to an unsafe state without
1191 // proper transition, but it happens after the final safepoint has begun.
1192 set_thread_state(_thread_in_vm);
1193 Threads_lock->lock();
1194 ShouldNotReachHere();
1195 }
1196 }
1197
1198 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
1199 _jni_attach_state = _not_attaching_via_jni;
1200 set_entry_point(entry_point);
1201 // Create the native thread itself.
1202 // %note runtime_23
1203 os::ThreadType thr_type = os::java_thread;
1204 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
1205 os::java_thread;
1206 os::create_thread(this, thr_type, stack_sz);
1207 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1208 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1209 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1210 // the exception consists of creating the exception object & initializing it, initialization
1211 // will leave the VM via a JavaCall and then all locks must be unlocked).
1212 //
1213 // The thread is still suspended when we reach here. Thread must be explicit started
1214 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1215 // by calling Threads:add. The reason why this is not done here, is because the thread
1216 // object must be fully initialized (take a look at JVM_Start)
1217 }
1218
1219 JavaThread::~JavaThread() {
1220
1221 // Ask ServiceThread to release the threadObj OopHandle
1222 ServiceThread::add_oop_handle_release(_threadObj);
1223
1224 // Return the sleep event to the free list
1225 ParkEvent::Release(_SleepEvent);
1226 _SleepEvent = NULL;
1227
1228 // Free any remaining previous UnrollBlock
1229 vframeArray* old_array = vframe_array_last();
1230
1231 if (old_array != NULL) {
1232 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1233 old_array->set_unroll_block(NULL);
1234 delete old_info;
1235 delete old_array;
1236 }
1237
1238 JvmtiDeferredUpdates* updates = deferred_updates();
1239 if (updates != NULL) {
1240 // This can only happen if thread is destroyed before deoptimization occurs.
1241 assert(updates->count() > 0, "Updates holder not deleted");
1242 // free deferred updates.
1243 delete updates;
1244 set_deferred_updates(NULL);
1245 }
1246
1247 // All Java related clean up happens in exit
1248 ThreadSafepointState::destroy(this);
1249 if (_thread_stat != NULL) delete _thread_stat;
1250
1251 #if INCLUDE_JVMCI
1252 if (JVMCICounterSize > 0) {
1253 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
1254 }
1255 #endif // INCLUDE_JVMCI
1256 }
1257
1258
1259 // First JavaThread specific code executed by a new Java thread.
1260 void JavaThread::pre_run() {
1261 // empty - see comments in run()
1262 }
1263
1264 // The main routine called by a new Java thread. This isn't overridden
1265 // by subclasses, instead different subclasses define a different "entry_point"
1266 // which defines the actual logic for that kind of thread.
1267 void JavaThread::run() {
1268 // initialize thread-local alloc buffer related fields
1269 initialize_tlab();
1270
1271 _stack_overflow_state.create_stack_guard_pages();
1272
1273 cache_global_variables();
1274
1275 // Thread is now sufficiently initialized to be handled by the safepoint code as being
1276 // in the VM. Change thread state from _thread_new to _thread_in_vm
1277 ThreadStateTransition::transition(this, _thread_new, _thread_in_vm);
1278 // Before a thread is on the threads list it is always safe, so after leaving the
1279 // _thread_new we should emit a instruction barrier. The distance to modified code
1280 // from here is probably far enough, but this is consistent and safe.
1281 OrderAccess::cross_modify_fence();
1282
1283 assert(JavaThread::current() == this, "sanity check");
1284 assert(!Thread::current()->owns_locks(), "sanity check");
1285
1286 DTRACE_THREAD_PROBE(start, this);
1287
1288 // This operation might block. We call that after all safepoint checks for a new thread has
1289 // been completed.
1290 set_active_handles(JNIHandleBlock::allocate_block());
1291
1292 if (JvmtiExport::should_post_thread_life()) {
1293 JvmtiExport::post_thread_start(this);
1294
1295 }
1296
1297 // We call another function to do the rest so we are sure that the stack addresses used
1298 // from there will be lower than the stack base just computed.
1299 thread_main_inner();
1300 }
1301
1302 void JavaThread::thread_main_inner() {
1303 assert(JavaThread::current() == this, "sanity check");
1304 assert(_threadObj.peek() != NULL, "just checking");
1305
1306 // Execute thread entry point unless this thread has a pending exception
1307 // or has been stopped before starting.
1308 // Note: Due to JVM_StopThread we can have pending exceptions already!
1309 if (!this->has_pending_exception() &&
1310 !java_lang_Thread::is_stillborn(this->threadObj())) {
1311 {
1312 ResourceMark rm(this);
1313 this->set_native_thread_name(this->get_thread_name());
1314 }
1315 HandleMark hm(this);
1316 this->entry_point()(this, this);
1317 }
1318
1319 DTRACE_THREAD_PROBE(stop, this);
1320
1321 // Cleanup is handled in post_run()
1322 }
1323
1324 // Shared teardown for all JavaThreads
1325 void JavaThread::post_run() {
1326 this->exit(false);
1327 this->unregister_thread_stack_with_NMT();
1328 // Defer deletion to here to ensure 'this' is still referenceable in call_run
1329 // for any shared tear-down.
1330 this->smr_delete();
1331 }
1332
1333 static void ensure_join(JavaThread* thread) {
1334 // We do not need to grab the Threads_lock, since we are operating on ourself.
1335 Handle threadObj(thread, thread->threadObj());
1336 assert(threadObj.not_null(), "java thread object must exist");
1337 ObjectLocker lock(threadObj, thread);
1338 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1339 thread->clear_pending_exception();
1340 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1341 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
1342 // Clear the native thread instance - this makes isAlive return false and allows the join()
1343 // to complete once we've done the notify_all below
1344 java_lang_Thread::set_thread(threadObj(), NULL);
1345 lock.notify_all(thread);
1346 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1347 thread->clear_pending_exception();
1348 }
1349
1350 static bool is_daemon(oop threadObj) {
1351 return (threadObj != NULL && java_lang_Thread::is_daemon(threadObj));
1352 }
1353
1354 // For any new cleanup additions, please check to see if they need to be applied to
1355 // cleanup_failed_attach_current_thread as well.
1356 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1357 assert(this == JavaThread::current(), "thread consistency check");
1358
1359 elapsedTimer _timer_exit_phase1;
1360 elapsedTimer _timer_exit_phase2;
1361 elapsedTimer _timer_exit_phase3;
1362 elapsedTimer _timer_exit_phase4;
1363
1364 if (log_is_enabled(Debug, os, thread, timer)) {
1365 _timer_exit_phase1.start();
1366 }
1367
1368 HandleMark hm(this);
1369 Handle uncaught_exception(this, this->pending_exception());
1370 this->clear_pending_exception();
1371 Handle threadObj(this, this->threadObj());
1372 assert(threadObj.not_null(), "Java thread object should be created");
1373
1374 if (!destroy_vm) {
1375 if (uncaught_exception.not_null()) {
1376 EXCEPTION_MARK;
1377 // Call method Thread.dispatchUncaughtException().
1378 Klass* thread_klass = vmClasses::Thread_klass();
1379 JavaValue result(T_VOID);
1380 JavaCalls::call_virtual(&result,
1381 threadObj, thread_klass,
1382 vmSymbols::dispatchUncaughtException_name(),
1383 vmSymbols::throwable_void_signature(),
1384 uncaught_exception,
1385 THREAD);
1386 if (HAS_PENDING_EXCEPTION) {
1387 ResourceMark rm(this);
1388 jio_fprintf(defaultStream::error_stream(),
1389 "\nException: %s thrown from the UncaughtExceptionHandler"
1390 " in thread \"%s\"\n",
1391 pending_exception()->klass()->external_name(),
1392 get_thread_name());
1393 CLEAR_PENDING_EXCEPTION;
1394 }
1395 }
1396
1397 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1398 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1399 // is deprecated anyhow.
1400 if (!is_Compiler_thread()) {
1401 int count = 3;
1402 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1403 EXCEPTION_MARK;
1404 JavaValue result(T_VOID);
1405 Klass* thread_klass = vmClasses::Thread_klass();
1406 JavaCalls::call_virtual(&result,
1407 threadObj, thread_klass,
1408 vmSymbols::exit_method_name(),
1409 vmSymbols::void_method_signature(),
1410 THREAD);
1411 CLEAR_PENDING_EXCEPTION;
1412 }
1413 }
1414 // notify JVMTI
1415 if (JvmtiExport::should_post_thread_life()) {
1416 JvmtiExport::post_thread_end(this);
1417 }
1418
1419 // The careful dance between thread suspension and exit is handled here.
1420 // Since we are in thread_in_vm state and suspension is done with handshakes,
1421 // we can just put in the exiting state and it will be correctly handled.
1422 set_terminated(_thread_exiting);
1423
1424 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
1425 } else {
1426 assert(!is_terminated() && !is_exiting(), "must not be exiting");
1427 // before_exit() has already posted JVMTI THREAD_END events
1428 }
1429
1430 if (log_is_enabled(Debug, os, thread, timer)) {
1431 _timer_exit_phase1.stop();
1432 _timer_exit_phase2.start();
1433 }
1434
1435 // Capture daemon status before the thread is marked as terminated.
1436 bool daemon = is_daemon(threadObj());
1437
1438 // Notify waiters on thread object. This has to be done after exit() is called
1439 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1440 // group should have the destroyed bit set before waiters are notified).
1441 ensure_join(this);
1442 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1443
1444 if (log_is_enabled(Debug, os, thread, timer)) {
1445 _timer_exit_phase2.stop();
1446 _timer_exit_phase3.start();
1447 }
1448 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1449 // held by this thread must be released. The spec does not distinguish
1450 // between JNI-acquired and regular Java monitors. We can only see
1451 // regular Java monitors here if monitor enter-exit matching is broken.
1452 //
1453 // ensure_join() ignores IllegalThreadStateExceptions, and so does
1454 // ObjectSynchronizer::release_monitors_owned_by_thread().
1455 if (exit_type == jni_detach) {
1456 // Sanity check even though JNI DetachCurrentThread() would have
1457 // returned JNI_ERR if there was a Java frame. JavaThread exit
1458 // should be done executing Java code by the time we get here.
1459 assert(!this->has_last_Java_frame(),
1460 "should not have a Java frame when detaching or exiting");
1461 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1462 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1463 }
1464
1465 // These things needs to be done while we are still a Java Thread. Make sure that thread
1466 // is in a consistent state, in case GC happens
1467 JFR_ONLY(Jfr::on_thread_exit(this);)
1468
1469 if (active_handles() != NULL) {
1470 JNIHandleBlock* block = active_handles();
1471 set_active_handles(NULL);
1472 JNIHandleBlock::release_block(block);
1473 }
1474
1475 if (free_handle_block() != NULL) {
1476 JNIHandleBlock* block = free_handle_block();
1477 set_free_handle_block(NULL);
1478 JNIHandleBlock::release_block(block);
1479 }
1480
1481 // These have to be removed while this is still a valid thread.
1482 _stack_overflow_state.remove_stack_guard_pages();
1483
1484 if (UseTLAB) {
1485 tlab().retire();
1486 }
1487
1488 if (JvmtiEnv::environments_might_exist()) {
1489 JvmtiExport::cleanup_thread(this);
1490 }
1491
1492 // We need to cache the thread name for logging purposes below as once
1493 // we have called on_thread_detach this thread must not access any oops.
1494 char* thread_name = NULL;
1495 if (log_is_enabled(Debug, os, thread, timer)) {
1496 ResourceMark rm(this);
1497 thread_name = os::strdup(get_thread_name());
1498 }
1499
1500 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
1501 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
1502 os::current_thread_id());
1503
1504 if (log_is_enabled(Debug, os, thread, timer)) {
1505 _timer_exit_phase3.stop();
1506 _timer_exit_phase4.start();
1507 }
1508
1509 #if INCLUDE_JVMCI
1510 if (JVMCICounterSize > 0) {
1511 if (jvmci_counters_include(this)) {
1512 for (int i = 0; i < JVMCICounterSize; i++) {
1513 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
1514 }
1515 }
1516 }
1517 #endif // INCLUDE_JVMCI
1518
1519 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1520 Threads::remove(this, daemon);
1521
1522 if (log_is_enabled(Debug, os, thread, timer)) {
1523 _timer_exit_phase4.stop();
1524 log_debug(os, thread, timer)("name='%s'"
1525 ", exit-phase1=" JLONG_FORMAT
1526 ", exit-phase2=" JLONG_FORMAT
1527 ", exit-phase3=" JLONG_FORMAT
1528 ", exit-phase4=" JLONG_FORMAT,
1529 thread_name,
1530 _timer_exit_phase1.milliseconds(),
1531 _timer_exit_phase2.milliseconds(),
1532 _timer_exit_phase3.milliseconds(),
1533 _timer_exit_phase4.milliseconds());
1534 os::free(thread_name);
1535 }
1536 }
1537
1538 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
1539 if (active_handles() != NULL) {
1540 JNIHandleBlock* block = active_handles();
1541 set_active_handles(NULL);
1542 JNIHandleBlock::release_block(block);
1543 }
1544
1545 if (free_handle_block() != NULL) {
1546 JNIHandleBlock* block = free_handle_block();
1547 set_free_handle_block(NULL);
1548 JNIHandleBlock::release_block(block);
1549 }
1550
1551 // These have to be removed while this is still a valid thread.
1552 _stack_overflow_state.remove_stack_guard_pages();
1553
1554 if (UseTLAB) {
1555 tlab().retire();
1556 }
1557
1558 Threads::remove(this, is_daemon);
1559 this->smr_delete();
1560 }
1561
1562 JavaThread* JavaThread::active() {
1563 Thread* thread = Thread::current();
1564 if (thread->is_Java_thread()) {
1565 return thread->as_Java_thread();
1566 } else {
1567 assert(thread->is_VM_thread(), "this must be a vm thread");
1568 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1569 JavaThread *ret = op == NULL ? NULL : op->calling_thread()->as_Java_thread();
1570 return ret;
1571 }
1572 }
1573
1574 bool JavaThread::is_lock_owned(address adr) const {
1575 assert(!UseFastLocking, "should not be called with fast-locking");
1576 if (Thread::is_lock_owned(adr)) return true;
1577
1578 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1579 if (chunk->contains(adr)) return true;
1580 }
1581
1582 return false;
1583 }
1584
1585 oop JavaThread::exception_oop() const {
1586 return Atomic::load(&_exception_oop);
1587 }
1588
1589 void JavaThread::set_exception_oop(oop o) {
1590 Atomic::store(&_exception_oop, o);
1591 }
1592
1593 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1594 chunk->set_next(monitor_chunks());
1595 set_monitor_chunks(chunk);
1596 }
1597
1598 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1599 guarantee(monitor_chunks() != NULL, "must be non empty");
1600 if (monitor_chunks() == chunk) {
1601 set_monitor_chunks(chunk->next());
1602 } else {
1603 MonitorChunk* prev = monitor_chunks();
1604 while (prev->next() != chunk) prev = prev->next();
1605 prev->set_next(chunk->next());
1606 }
1607 }
1608
1609
1610 // Asynchronous exceptions support
1611 //
1612 // Note: this function shouldn't block if it's called in
1613 // _thread_in_native_trans state (such as from
1614 // check_special_condition_for_native_trans()).
1615 void JavaThread::check_and_handle_async_exceptions() {
1616 if (has_last_Java_frame() && has_async_exception_condition()) {
1617 // If we are at a polling page safepoint (not a poll return)
1618 // then we must defer async exception because live registers
1619 // will be clobbered by the exception path. Poll return is
1620 // ok because the call we a returning from already collides
1621 // with exception handling registers and so there is no issue.
1622 // (The exception handling path kills call result registers but
1623 // this is ok since the exception kills the result anyway).
1624
1625 if (is_at_poll_safepoint()) {
1626 // if the code we are returning to has deoptimized we must defer
1627 // the exception otherwise live registers get clobbered on the
1628 // exception path before deoptimization is able to retrieve them.
1629 //
1630 RegisterMap map(this, false);
1631 frame caller_fr = last_frame().sender(&map);
1632 assert(caller_fr.is_compiled_frame(), "what?");
1633 if (caller_fr.is_deoptimized_frame()) {
1634 log_info(exceptions)("deferred async exception at compiled safepoint");
1635 return;
1636 }
1637 }
1638 }
1639
1640 AsyncExceptionCondition condition = clear_async_exception_condition();
1641 if (condition == _no_async_condition) {
1642 // Conditions have changed since has_special_runtime_exit_condition()
1643 // was called:
1644 // - if we were here only because of an external suspend request,
1645 // then that was taken care of above (or cancelled) so we are done
1646 // - if we were here because of another async request, then it has
1647 // been cleared between the has_special_runtime_exit_condition()
1648 // and now so again we are done
1649 return;
1650 }
1651
1652 // Check for pending async. exception
1653 if (_pending_async_exception != NULL) {
1654 // Only overwrite an already pending exception, if it is not a threadDeath.
1655 if (!has_pending_exception() || !pending_exception()->is_a(vmClasses::ThreadDeath_klass())) {
1656
1657 // We cannot call Exceptions::_throw(...) here because we cannot block
1658 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1659
1660 LogTarget(Info, exceptions) lt;
1661 if (lt.is_enabled()) {
1662 ResourceMark rm;
1663 LogStream ls(lt);
1664 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1665 if (has_last_Java_frame()) {
1666 frame f = last_frame();
1667 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1668 }
1669 ls.print_cr(" of type: %s", _pending_async_exception->klass()->external_name());
1670 }
1671 _pending_async_exception = NULL;
1672 // Clear condition from _suspend_flags since we have finished processing it.
1673 clear_suspend_flag(_has_async_exception);
1674 }
1675 }
1676
1677 if (condition == _async_unsafe_access_error && !has_pending_exception()) {
1678 // We may be at method entry which requires we save the do-not-unlock flag.
1679 UnlockFlagSaver fs(this);
1680 switch (thread_state()) {
1681 case _thread_in_vm: {
1682 JavaThread* THREAD = this;
1683 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in an unsafe memory access operation");
1684 return;
1685 }
1686 case _thread_in_native: {
1687 ThreadInVMfromNative tiv(this);
1688 JavaThread* THREAD = this;
1689 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in an unsafe memory access operation");
1690 return;
1691 }
1692 case _thread_in_Java: {
1693 ThreadInVMfromJava tiv(this);
1694 JavaThread* THREAD = this;
1695 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1696 return;
1697 }
1698 default:
1699 ShouldNotReachHere();
1700 }
1701 }
1702
1703 assert(has_pending_exception(), "must have handled the async condition if no exception");
1704 }
1705
1706 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1707
1708 if (is_obj_deopt_suspend()) {
1709 frame_anchor()->make_walkable();
1710 wait_for_object_deoptimization();
1711 }
1712
1713 // We might be here for reasons in addition to the self-suspend request
1714 // so check for other async requests.
1715 if (check_asyncs) {
1716 check_and_handle_async_exceptions();
1717 }
1718
1719 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1720 }
1721
1722 class InstallAsyncExceptionClosure : public HandshakeClosure {
1723 Handle _throwable; // The Throwable thrown at the target Thread
1724 public:
1725 InstallAsyncExceptionClosure(Handle throwable) : HandshakeClosure("InstallAsyncException"), _throwable(throwable) {}
1726
1727 void do_thread(Thread* thr) {
1728 JavaThread* target = thr->as_Java_thread();
1729 // Note that this now allows multiple ThreadDeath exceptions to be
1730 // thrown at a thread.
1731 // The target thread has run and has not exited yet.
1732 target->send_thread_stop(_throwable());
1733 }
1734 };
1735
1736 void JavaThread::send_async_exception(oop java_thread, oop java_throwable) {
1737 Handle throwable(Thread::current(), java_throwable);
1738 JavaThread* target = java_lang_Thread::thread(java_thread);
1739 InstallAsyncExceptionClosure vm_stop(throwable);
1740 Handshake::execute(&vm_stop, target);
1741 }
1742
1743 void JavaThread::send_thread_stop(oop java_throwable) {
1744 ResourceMark rm;
1745 assert(is_handshake_safe_for(Thread::current()),
1746 "should be self or handshakee");
1747
1748 // Do not throw asynchronous exceptions against the compiler thread
1749 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1750 if (!can_call_java()) return;
1751
1752 {
1753 // Actually throw the Throwable against the target Thread - however
1754 // only if there is no thread death exception installed already.
1755 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(vmClasses::ThreadDeath_klass())) {
1756 // If the topmost frame is a runtime stub, then we are calling into
1757 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1758 // must deoptimize the caller before continuing, as the compiled exception handler table
1759 // may not be valid
1760 if (has_last_Java_frame()) {
1761 frame f = last_frame();
1762 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1763 RegisterMap reg_map(this, false);
1764 frame compiled_frame = f.sender(®_map);
1765 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1766 Deoptimization::deoptimize(this, compiled_frame);
1767 }
1768 }
1769 }
1770
1771 // Set async. pending exception in thread.
1772 set_pending_async_exception(java_throwable);
1773
1774 if (log_is_enabled(Info, exceptions)) {
1775 ResourceMark rm;
1776 log_info(exceptions)("Pending Async. exception installed of type: %s",
1777 InstanceKlass::cast(_pending_async_exception->klass())->external_name());
1778 }
1779 // for AbortVMOnException flag
1780 Exceptions::debug_check_abort(_pending_async_exception->klass()->external_name());
1781 }
1782 }
1783
1784
1785 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1786 java_lang_Thread::set_interrupted(threadObj(), true);
1787 this->interrupt();
1788 }
1789
1790
1791 // External suspension mechanism.
1792 //
1793 // Guarantees on return (for a valid target thread):
1794 // - Target thread will not execute any new bytecode.
1795 // - Target thread will not enter any new monitors.
1796 //
1797 bool JavaThread::java_suspend() {
1798 ThreadsListHandle tlh;
1799 if (!tlh.includes(this)) {
1800 log_trace(thread, suspend)("JavaThread:" INTPTR_FORMAT " not on ThreadsList, no suspension", p2i(this));
1801 return false;
1802 }
1803 return this->handshake_state()->suspend();
1804 }
1805
1806 bool JavaThread::java_resume() {
1807 ThreadsListHandle tlh;
1808 if (!tlh.includes(this)) {
1809 log_trace(thread, suspend)("JavaThread:" INTPTR_FORMAT " not on ThreadsList, nothing to resume", p2i(this));
1810 return false;
1811 }
1812 return this->handshake_state()->resume();
1813 }
1814
1815 // Wait for another thread to perform object reallocation and relocking on behalf of
1816 // this thread.
1817 // Raw thread state transition to _thread_blocked and back again to the original
1818 // state before returning are performed. The current thread is required to
1819 // change to _thread_blocked in order to be seen to be safepoint/handshake safe
1820 // whilst suspended and only after becoming handshake safe, the other thread can
1821 // complete the handshake used to synchronize with this thread and then perform
1822 // the reallocation and relocking. We cannot use the thread state transition
1823 // helpers because we arrive here in various states and also because the helpers
1824 // indirectly call this method. After leaving _thread_blocked we have to check
1825 // for safepoint/handshake, except if _thread_in_native. The thread is safe
1826 // without blocking then. Allowed states are enumerated in
1827 // SafepointSynchronize::block(). See also EscapeBarrier::sync_and_suspend_*()
1828
1829 void JavaThread::wait_for_object_deoptimization() {
1830 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1831 assert(this == Thread::current(), "invariant");
1832 JavaThreadState state = thread_state();
1833
1834 bool spin_wait = os::is_MP();
1835 do {
1836 set_thread_state(_thread_blocked);
1837 // Wait for object deoptimization if requested.
1838 if (spin_wait) {
1839 // A single deoptimization is typically very short. Microbenchmarks
1840 // showed 5% better performance when spinning.
1841 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1842 SpinYield spin(spin_limit);
1843 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1844 spin.wait();
1845 }
1846 // Spin just once
1847 spin_wait = false;
1848 } else {
1849 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1850 if (is_obj_deopt_suspend()) {
1851 ml.wait();
1852 }
1853 }
1854 // The current thread could have been suspended again. We have to check for
1855 // suspend after restoring the saved state. Without this the current thread
1856 // might return to _thread_in_Java and execute bytecode.
1857 set_thread_state_fence(state);
1858
1859 if (state != _thread_in_native) {
1860 SafepointMechanism::process_if_requested(this);
1861 }
1862 // A handshake for obj. deoptimization suspend could have been processed so
1863 // we must check after processing.
1864 } while (is_obj_deopt_suspend());
1865 }
1866
1867 #ifdef ASSERT
1868 // Verify the JavaThread has not yet been published in the Threads::list, and
1869 // hence doesn't need protection from concurrent access at this stage.
1870 void JavaThread::verify_not_published() {
1871 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1872 // since an unpublished JavaThread doesn't participate in the
1873 // Thread-SMR protocol for keeping a ThreadsList alive.
1874 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1875 }
1876 #endif
1877
1878 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1879 // pending, when _suspend_flags is non-zero or when we need to process a stack
1880 // watermark. Also check for pending async exceptions (except unsafe access error).
1881 // Note only the native==>Java barriers can call this function when thread state
1882 // is _thread_in_native_trans.
1883 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1884 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1885 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1886
1887 // Enable WXWrite: called directly from interpreter native wrapper.
1888 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1889
1890 SafepointMechanism::process_if_requested_with_exit_check(thread, false /* check asyncs */);
1891
1892 // After returning from native, it could be that the stack frames are not
1893 // yet safe to use. We catch such situations in the subsequent stack watermark
1894 // barrier, which will trap unsafe stack frames.
1895 StackWatermarkSet::before_unwind(thread);
1896
1897 if (thread->has_async_exception_condition(false /* check unsafe access error */)) {
1898 // We are in _thread_in_native_trans state, don't handle unsafe
1899 // access error since that may block.
1900 thread->check_and_handle_async_exceptions();
1901 }
1902 }
1903
1904 #ifndef PRODUCT
1905 // Deoptimization
1906 // Function for testing deoptimization
1907 void JavaThread::deoptimize() {
1908 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1909 bool deopt = false; // Dump stack only if a deopt actually happens.
1910 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1911 // Iterate over all frames in the thread and deoptimize
1912 for (; !fst.is_done(); fst.next()) {
1913 if (fst.current()->can_be_deoptimized()) {
1914
1915 if (only_at) {
1916 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1917 // consists of comma or carriage return separated numbers so
1918 // search for the current bci in that string.
1919 address pc = fst.current()->pc();
1920 nmethod* nm = (nmethod*) fst.current()->cb();
1921 ScopeDesc* sd = nm->scope_desc_at(pc);
1922 char buffer[8];
1923 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1924 size_t len = strlen(buffer);
1925 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1926 while (found != NULL) {
1927 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1928 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1929 // Check that the bci found is bracketed by terminators.
1930 break;
1931 }
1932 found = strstr(found + 1, buffer);
1933 }
1934 if (!found) {
1935 continue;
1936 }
1937 }
1938
1939 if (DebugDeoptimization && !deopt) {
1940 deopt = true; // One-time only print before deopt
1941 tty->print_cr("[BEFORE Deoptimization]");
1942 trace_frames();
1943 trace_stack();
1944 }
1945 Deoptimization::deoptimize(this, *fst.current());
1946 }
1947 }
1948
1949 if (DebugDeoptimization && deopt) {
1950 tty->print_cr("[AFTER Deoptimization]");
1951 trace_frames();
1952 }
1953 }
1954
1955
1956 // Make zombies
1957 void JavaThread::make_zombies() {
1958 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1959 if (fst.current()->can_be_deoptimized()) {
1960 // it is a Java nmethod
1961 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1962 nm->make_not_entrant();
1963 }
1964 }
1965 }
1966 #endif // PRODUCT
1967
1968
1969 void JavaThread::deoptimize_marked_methods() {
1970 if (!has_last_Java_frame()) return;
1971 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1972 for (; !fst.is_done(); fst.next()) {
1973 if (fst.current()->should_be_deoptimized()) {
1974 Deoptimization::deoptimize(this, *fst.current());
1975 }
1976 }
1977 }
1978
1979 #ifdef ASSERT
1980 void JavaThread::verify_frame_info() {
1981 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1982 (has_last_Java_frame() && java_call_counter() > 0),
1983 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1984 has_last_Java_frame() ? "true" : "false", java_call_counter());
1985 }
1986 #endif
1987
1988 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1989 // Verify that the deferred card marks have been flushed.
1990 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1991
1992 // Traverse the GCHandles
1993 Thread::oops_do_no_frames(f, cf);
1994
1995 DEBUG_ONLY(verify_frame_info();)
1996
1997 if (has_last_Java_frame()) {
1998 // Traverse the monitor chunks
1999 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2000 chunk->oops_do(f);
2001 }
2002 }
2003
2004 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2005 // If we have deferred set_locals there might be oops waiting to be
2006 // written
2007 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
2008 if (list != NULL) {
2009 for (int i = 0; i < list->length(); i++) {
2010 list->at(i)->oops_do(f);
2011 }
2012 }
2013
2014 // Traverse instance variables at the end since the GC may be moving things
2015 // around using this function
2016 f->do_oop((oop*) &_vm_result);
2017 f->do_oop((oop*) &_exception_oop);
2018 f->do_oop((oop*) &_pending_async_exception);
2019 #if INCLUDE_JVMCI
2020 f->do_oop((oop*) &_jvmci_reserved_oop0);
2021 #endif
2022
2023 if (jvmti_thread_state() != NULL) {
2024 jvmti_thread_state()->oops_do(f, cf);
2025 }
2026
2027 if (!UseHeavyMonitors && UseFastLocking) {
2028 lock_stack().oops_do(f);
2029 }
2030 }
2031
2032 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
2033 if (!has_last_Java_frame()) {
2034 return;
2035 }
2036 // Finish any pending lazy GC activity for the frames
2037 StackWatermarkSet::finish_processing(this, NULL /* context */, StackWatermarkKind::gc);
2038 // Traverse the execution stack
2039 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
2040 fst.current()->oops_do(f, cf, fst.register_map());
2041 }
2042 }
2043
2044 #ifdef ASSERT
2045 void JavaThread::verify_states_for_handshake() {
2046 // This checks that the thread has a correct frame state during a handshake.
2047 verify_frame_info();
2048 }
2049 #endif
2050
2051 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2052 DEBUG_ONLY(verify_frame_info();)
2053
2054 if (has_last_Java_frame()) {
2055 // Traverse the execution stack
2056 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2057 fst.current()->nmethods_do(cf);
2058 }
2059 }
2060
2061 if (jvmti_thread_state() != NULL) {
2062 jvmti_thread_state()->nmethods_do(cf);
2063 }
2064 }
2065
2066 void JavaThread::metadata_do(MetadataClosure* f) {
2067 if (has_last_Java_frame()) {
2068 // Traverse the execution stack to call f() on the methods in the stack
2069 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2070 fst.current()->metadata_do(f);
2071 }
2072 } else if (is_Compiler_thread()) {
2073 // need to walk ciMetadata in current compile tasks to keep alive.
2074 CompilerThread* ct = (CompilerThread*)this;
2075 if (ct->env() != NULL) {
2076 ct->env()->metadata_do(f);
2077 }
2078 CompileTask* task = ct->task();
2079 if (task != NULL) {
2080 task->metadata_do(f);
2081 }
2082 }
2083 }
2084
2085 // Printing
2086 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2087 switch (_thread_state) {
2088 case _thread_uninitialized: return "_thread_uninitialized";
2089 case _thread_new: return "_thread_new";
2090 case _thread_new_trans: return "_thread_new_trans";
2091 case _thread_in_native: return "_thread_in_native";
2092 case _thread_in_native_trans: return "_thread_in_native_trans";
2093 case _thread_in_vm: return "_thread_in_vm";
2094 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2095 case _thread_in_Java: return "_thread_in_Java";
2096 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2097 case _thread_blocked: return "_thread_blocked";
2098 case _thread_blocked_trans: return "_thread_blocked_trans";
2099 default: return "unknown thread state";
2100 }
2101 }
2102
2103 #ifndef PRODUCT
2104 void JavaThread::print_thread_state_on(outputStream *st) const {
2105 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2106 };
2107 #endif // PRODUCT
2108
2109 // Called by Threads::print() for VM_PrintThreads operation
2110 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
2111 st->print_raw("\"");
2112 st->print_raw(get_thread_name());
2113 st->print_raw("\" ");
2114 oop thread_oop = threadObj();
2115 if (thread_oop != NULL) {
2116 st->print("#" INT64_FORMAT " ", (int64_t)java_lang_Thread::thread_id(thread_oop));
2117 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2118 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2119 }
2120 Thread::print_on(st, print_extended_info);
2121 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2122 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2123 if (thread_oop != NULL) {
2124 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2125 }
2126 #ifndef PRODUCT
2127 _safepoint_state->print_on(st);
2128 #endif // PRODUCT
2129 if (is_Compiler_thread()) {
2130 CompileTask *task = ((CompilerThread*)this)->task();
2131 if (task != NULL) {
2132 st->print(" Compiling: ");
2133 task->print(st, NULL, true, false);
2134 } else {
2135 st->print(" No compile task");
2136 }
2137 st->cr();
2138 }
2139 }
2140
2141 void JavaThread::print() const { print_on(tty); }
2142
2143 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
2144 st->print("%s", get_thread_name_string(buf, buflen));
2145 }
2146
2147 // Called by fatal error handler. The difference between this and
2148 // JavaThread::print() is that we can't grab lock or allocate memory.
2149 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2150 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2151 oop thread_obj = threadObj();
2152 if (thread_obj != NULL) {
2153 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2154 }
2155 st->print(" [");
2156 st->print("%s", _get_thread_state_name(_thread_state));
2157 if (osthread()) {
2158 st->print(", id=%d", osthread()->thread_id());
2159 }
2160 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2161 p2i(stack_end()), p2i(stack_base()));
2162 st->print("]");
2163
2164 ThreadsSMRSupport::print_info_on(this, st);
2165 return;
2166 }
2167
2168
2169 // Verification
2170
2171 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2172 // ignore if there is no stack
2173 if (!has_last_Java_frame()) return;
2174 // traverse the stack frames. Starts from top frame.
2175 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2176 frame* fr = fst.current();
2177 f(fr, fst.register_map());
2178 }
2179 }
2180
2181 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2182
2183 void JavaThread::verify() {
2184 // Verify oops in the thread.
2185 oops_do(&VerifyOopClosure::verify_oop, NULL);
2186
2187 // Verify the stack frames.
2188 frames_do(frame_verify);
2189 }
2190
2191 // CR 6300358 (sub-CR 2137150)
2192 // Most callers of this method assume that it can't return NULL but a
2193 // thread may not have a name whilst it is in the process of attaching to
2194 // the VM - see CR 6412693, and there are places where a JavaThread can be
2195 // seen prior to having its threadObj set (e.g., JNI attaching threads and
2196 // if vm exit occurs during initialization). These cases can all be accounted
2197 // for such that this method never returns NULL.
2198 const char* JavaThread::get_thread_name() const {
2199 if (Thread::is_JavaThread_protected(this)) {
2200 // The target JavaThread is protected so get_thread_name_string() is safe:
2201 return get_thread_name_string();
2202 }
2203
2204 // The target JavaThread is not protected so we return the default:
2205 return Thread::name();
2206 }
2207
2208 // Returns a non-NULL representation of this thread's name, or a suitable
2209 // descriptive string if there is no set name.
2210 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2211 const char* name_str;
2212 oop thread_obj = threadObj();
2213 if (thread_obj != NULL) {
2214 oop name = java_lang_Thread::name(thread_obj);
2215 if (name != NULL) {
2216 if (buf == NULL) {
2217 name_str = java_lang_String::as_utf8_string(name);
2218 } else {
2219 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
2220 }
2221 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2222 name_str = "<no-name - thread is attaching>";
2223 } else {
2224 name_str = Thread::name();
2225 }
2226 } else {
2227 name_str = Thread::name();
2228 }
2229 assert(name_str != NULL, "unexpected NULL thread name");
2230 return name_str;
2231 }
2232
2233 // Helper to extract the name from the thread oop for logging.
2234 const char* JavaThread::name_for(oop thread_obj) {
2235 assert(thread_obj != NULL, "precondition");
2236 oop name = java_lang_Thread::name(thread_obj);
2237 const char* name_str;
2238 if (name != NULL) {
2239 name_str = java_lang_String::as_utf8_string(name);
2240 } else {
2241 name_str = "<un-named>";
2242 }
2243 return name_str;
2244 }
2245
2246 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2247
2248 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2249 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
2250 // Link Java Thread object <-> C++ Thread
2251
2252 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2253 // and put it into a new Handle. The Handle "thread_oop" can then
2254 // be used to pass the C++ thread object to other methods.
2255
2256 // Set the Java level thread object (jthread) field of the
2257 // new thread (a JavaThread *) to C++ thread object using the
2258 // "thread_oop" handle.
2259
2260 // Set the thread field (a JavaThread *) of the
2261 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2262
2263 Handle thread_oop(Thread::current(),
2264 JNIHandles::resolve_non_null(jni_thread));
2265 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
2266 "must be initialized");
2267 set_threadObj(thread_oop());
2268 java_lang_Thread::set_thread(thread_oop(), this);
2269
2270 if (prio == NoPriority) {
2271 prio = java_lang_Thread::priority(thread_oop());
2272 assert(prio != NoPriority, "A valid priority should be present");
2273 }
2274
2275 // Push the Java priority down to the native thread; needs Threads_lock
2276 Thread::set_priority(this, prio);
2277
2278 // Add the new thread to the Threads list and set it in motion.
2279 // We must have threads lock in order to call Threads::add.
2280 // It is crucial that we do not block before the thread is
2281 // added to the Threads list for if a GC happens, then the java_thread oop
2282 // will not be visited by GC.
2283 Threads::add(this);
2284 }
2285
2286 oop JavaThread::current_park_blocker() {
2287 // Support for JSR-166 locks
2288 oop thread_oop = threadObj();
2289 if (thread_oop != NULL) {
2290 return java_lang_Thread::park_blocker(thread_oop);
2291 }
2292 return NULL;
2293 }
2294
2295
2296 void JavaThread::print_stack_on(outputStream* st) {
2297 if (!has_last_Java_frame()) return;
2298
2299 Thread* current_thread = Thread::current();
2300 ResourceMark rm(current_thread);
2301 HandleMark hm(current_thread);
2302
2303 RegisterMap reg_map(this);
2304 vframe* start_vf = last_java_vframe(®_map);
2305 int count = 0;
2306 for (vframe* f = start_vf; f != NULL; f = f->sender()) {
2307 if (f->is_java_frame()) {
2308 javaVFrame* jvf = javaVFrame::cast(f);
2309 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2310
2311 // Print out lock information
2312 if (JavaMonitorsInStackTrace) {
2313 jvf->print_lock_info_on(st, count);
2314 }
2315 } else {
2316 // Ignore non-Java frames
2317 }
2318
2319 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
2320 count++;
2321 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
2322 }
2323 }
2324
2325
2326 // JVMTI PopFrame support
2327 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2328 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2329 if (in_bytes(size_in_bytes) != 0) {
2330 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
2331 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2332 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2333 }
2334 }
2335
2336 void* JavaThread::popframe_preserved_args() {
2337 return _popframe_preserved_args;
2338 }
2339
2340 ByteSize JavaThread::popframe_preserved_args_size() {
2341 return in_ByteSize(_popframe_preserved_args_size);
2342 }
2343
2344 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2345 int sz = in_bytes(popframe_preserved_args_size());
2346 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2347 return in_WordSize(sz / wordSize);
2348 }
2349
2350 void JavaThread::popframe_free_preserved_args() {
2351 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2352 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
2353 _popframe_preserved_args = NULL;
2354 _popframe_preserved_args_size = 0;
2355 }
2356
2357 #ifndef PRODUCT
2358
2359 void JavaThread::trace_frames() {
2360 tty->print_cr("[Describe stack]");
2361 int frame_no = 1;
2362 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2363 tty->print(" %d. ", frame_no++);
2364 fst.current()->print_value_on(tty, this);
2365 tty->cr();
2366 }
2367 }
2368
2369 class PrintAndVerifyOopClosure: public OopClosure {
2370 protected:
2371 template <class T> inline void do_oop_work(T* p) {
2372 oop obj = RawAccess<>::oop_load(p);
2373 if (obj == NULL) return;
2374 tty->print(INTPTR_FORMAT ": ", p2i(p));
2375 if (oopDesc::is_oop_or_null(obj)) {
2376 if (obj->is_objArray()) {
2377 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
2378 } else {
2379 obj->print();
2380 }
2381 } else {
2382 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
2383 }
2384 tty->cr();
2385 }
2386 public:
2387 virtual void do_oop(oop* p) { do_oop_work(p); }
2388 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
2389 };
2390
2391 #ifdef ASSERT
2392 // Print or validate the layout of stack frames
2393 void JavaThread::print_frame_layout(int depth, bool validate_only) {
2394 ResourceMark rm;
2395 PreserveExceptionMark pm(this);
2396 FrameValues values;
2397 int frame_no = 0;
2398 for (StackFrameStream fst(this, false /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2399 fst.current()->describe(values, ++frame_no);
2400 if (depth == frame_no) break;
2401 }
2402 if (validate_only) {
2403 values.validate();
2404 } else {
2405 tty->print_cr("[Describe stack layout]");
2406 values.print(this);
2407 }
2408 }
2409 #endif
2410
2411 void JavaThread::trace_stack_from(vframe* start_vf) {
2412 ResourceMark rm;
2413 int vframe_no = 1;
2414 for (vframe* f = start_vf; f; f = f->sender()) {
2415 if (f->is_java_frame()) {
2416 javaVFrame::cast(f)->print_activation(vframe_no++);
2417 } else {
2418 f->print();
2419 }
2420 if (vframe_no > StackPrintLimit) {
2421 tty->print_cr("...<more frames>...");
2422 return;
2423 }
2424 }
2425 }
2426
2427
2428 void JavaThread::trace_stack() {
2429 if (!has_last_Java_frame()) return;
2430 Thread* current_thread = Thread::current();
2431 ResourceMark rm(current_thread);
2432 HandleMark hm(current_thread);
2433 RegisterMap reg_map(this);
2434 trace_stack_from(last_java_vframe(®_map));
2435 }
2436
2437
2438 #endif // PRODUCT
2439
2440
2441 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2442 assert(reg_map != NULL, "a map must be given");
2443 frame f = last_frame();
2444 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
2445 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2446 }
2447 return NULL;
2448 }
2449
2450
2451 Klass* JavaThread::security_get_caller_class(int depth) {
2452 vframeStream vfst(this);
2453 vfst.security_get_caller_frame(depth);
2454 if (!vfst.at_end()) {
2455 return vfst.method()->method_holder();
2456 }
2457 return NULL;
2458 }
2459
2460 // java.lang.Thread.sleep support
2461 // Returns true if sleep time elapsed as expected, and false
2462 // if the thread was interrupted.
2463 bool JavaThread::sleep(jlong millis) {
2464 assert(this == Thread::current(), "thread consistency check");
2465
2466 ParkEvent * const slp = this->_SleepEvent;
2467 // Because there can be races with thread interruption sending an unpark()
2468 // to the event, we explicitly reset it here to avoid an immediate return.
2469 // The actual interrupt state will be checked before we park().
2470 slp->reset();
2471 // Thread interruption establishes a happens-before ordering in the
2472 // Java Memory Model, so we need to ensure we synchronize with the
2473 // interrupt state.
2474 OrderAccess::fence();
2475
2476 jlong prevtime = os::javaTimeNanos();
2477
2478 for (;;) {
2479 // interruption has precedence over timing out
2480 if (this->is_interrupted(true)) {
2481 return false;
2482 }
2483
2484 if (millis <= 0) {
2485 return true;
2486 }
2487
2488 {
2489 ThreadBlockInVM tbivm(this);
2490 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2491 slp->park(millis);
2492 }
2493
2494 // Update elapsed time tracking
2495 jlong newtime = os::javaTimeNanos();
2496 if (newtime - prevtime < 0) {
2497 // time moving backwards, should only happen if no monotonic clock
2498 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2499 assert(false,
2500 "unexpected time moving backwards detected in JavaThread::sleep()");
2501 } else {
2502 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2503 }
2504 prevtime = newtime;
2505 }
2506 }
2507
2508
2509 // ======= Threads ========
2510
2511 // The Threads class links together all active threads, and provides
2512 // operations over all threads. It is protected by the Threads_lock,
2513 // which is also used in other global contexts like safepointing.
2514 // ThreadsListHandles are used to safely perform operations on one
2515 // or more threads without the risk of the thread exiting during the
2516 // operation.
2517 //
2518 // Note: The Threads_lock is currently more widely used than we
2519 // would like. We are actively migrating Threads_lock uses to other
2520 // mechanisms in order to reduce Threads_lock contention.
2521
2522 int Threads::_number_of_threads = 0;
2523 int Threads::_number_of_non_daemon_threads = 0;
2524 int Threads::_return_code = 0;
2525 uintx Threads::_thread_claim_token = 1; // Never zero.
2526 size_t JavaThread::_stack_size_at_create = 0;
2527
2528 #ifdef ASSERT
2529 bool Threads::_vm_complete = false;
2530 #endif
2531
2532 static inline void *prefetch_and_load_ptr(void **addr, intx prefetch_interval) {
2533 Prefetch::read((void*)addr, prefetch_interval);
2534 return *addr;
2535 }
2536
2537 // Possibly the ugliest for loop the world has seen. C++ does not allow
2538 // multiple types in the declaration section of the for loop. In this case
2539 // we are only dealing with pointers and hence can cast them. It looks ugly
2540 // but macros are ugly and therefore it's fine to make things absurdly ugly.
2541 #define DO_JAVA_THREADS(LIST, X) \
2542 for (JavaThread *MACRO_scan_interval = (JavaThread*)(uintptr_t)PrefetchScanIntervalInBytes, \
2543 *MACRO_list = (JavaThread*)(LIST), \
2544 **MACRO_end = ((JavaThread**)((ThreadsList*)MACRO_list)->threads()) + ((ThreadsList*)MACRO_list)->length(), \
2545 **MACRO_current_p = (JavaThread**)((ThreadsList*)MACRO_list)->threads(), \
2546 *X = (JavaThread*)prefetch_and_load_ptr((void**)MACRO_current_p, (intx)MACRO_scan_interval); \
2547 MACRO_current_p != MACRO_end; \
2548 MACRO_current_p++, \
2549 X = (JavaThread*)prefetch_and_load_ptr((void**)MACRO_current_p, (intx)MACRO_scan_interval))
2550
2551 // All JavaThreads
2552 #define ALL_JAVA_THREADS(X) DO_JAVA_THREADS(ThreadsSMRSupport::get_java_thread_list(), X)
2553
2554 // All NonJavaThreads (i.e., every non-JavaThread in the system).
2555 void Threads::non_java_threads_do(ThreadClosure* tc) {
2556 NoSafepointVerifier nsv;
2557 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
2558 tc->do_thread(njti.current());
2559 }
2560 }
2561
2562 // All JavaThreads
2563 void Threads::java_threads_do(ThreadClosure* tc) {
2564 assert_locked_or_safepoint(Threads_lock);
2565 // ALL_JAVA_THREADS iterates through all JavaThreads.
2566 ALL_JAVA_THREADS(p) {
2567 tc->do_thread(p);
2568 }
2569 }
2570
2571 void Threads::java_threads_and_vm_thread_do(ThreadClosure* tc) {
2572 assert_locked_or_safepoint(Threads_lock);
2573 java_threads_do(tc);
2574 tc->do_thread(VMThread::vm_thread());
2575 }
2576
2577 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
2578 void Threads::threads_do(ThreadClosure* tc) {
2579 assert_locked_or_safepoint(Threads_lock);
2580 java_threads_do(tc);
2581 non_java_threads_do(tc);
2582 }
2583
2584 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
2585 uintx claim_token = Threads::thread_claim_token();
2586 ALL_JAVA_THREADS(p) {
2587 if (p->claim_threads_do(is_par, claim_token)) {
2588 tc->do_thread(p);
2589 }
2590 }
2591 VMThread* vmt = VMThread::vm_thread();
2592 if (vmt->claim_threads_do(is_par, claim_token)) {
2593 tc->do_thread(vmt);
2594 }
2595 }
2596
2597 // The system initialization in the library has three phases.
2598 //
2599 // Phase 1: java.lang.System class initialization
2600 // java.lang.System is a primordial class loaded and initialized
2601 // by the VM early during startup. java.lang.System.<clinit>
2602 // only does registerNatives and keeps the rest of the class
2603 // initialization work later until thread initialization completes.
2604 //
2605 // System.initPhase1 initializes the system properties, the static
2606 // fields in, out, and err. Set up java signal handlers, OS-specific
2607 // system settings, and thread group of the main thread.
2608 static void call_initPhase1(TRAPS) {
2609 Klass* klass = vmClasses::System_klass();
2610 JavaValue result(T_VOID);
2611 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
2612 vmSymbols::void_method_signature(), CHECK);
2613 }
2614
2615 // Phase 2. Module system initialization
2616 // This will initialize the module system. Only java.base classes
2617 // can be loaded until phase 2 completes.
2618 //
2619 // Call System.initPhase2 after the compiler initialization and jsr292
2620 // classes get initialized because module initialization runs a lot of java
2621 // code, that for performance reasons, should be compiled. Also, this will
2622 // enable the startup code to use lambda and other language features in this
2623 // phase and onward.
2624 //
2625 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
2626 static void call_initPhase2(TRAPS) {
2627 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
2628
2629 Klass* klass = vmClasses::System_klass();
2630
2631 JavaValue result(T_INT);
2632 JavaCallArguments args;
2633 args.push_int(DisplayVMOutputToStderr);
2634 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
2635 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
2636 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
2637 if (result.get_jint() != JNI_OK) {
2638 vm_exit_during_initialization(); // no message or exception
2639 }
2640
2641 universe_post_module_init();
2642 }
2643
2644 // Phase 3. final setup - set security manager, system class loader and TCCL
2645 //
2646 // This will instantiate and set the security manager, set the system class
2647 // loader as well as the thread context class loader. The security manager
2648 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
2649 // other modules or the application's classpath.
2650 static void call_initPhase3(TRAPS) {
2651 Klass* klass = vmClasses::System_klass();
2652 JavaValue result(T_VOID);
2653 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
2654 vmSymbols::void_method_signature(), CHECK);
2655 }
2656
2657 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
2658 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
2659
2660 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
2661 create_vm_init_libraries();
2662 }
2663
2664 initialize_class(vmSymbols::java_lang_String(), CHECK);
2665
2666 // Inject CompactStrings value after the static initializers for String ran.
2667 java_lang_String::set_compact_strings(CompactStrings);
2668
2669 // Initialize java_lang.System (needed before creating the thread)
2670 initialize_class(vmSymbols::java_lang_System(), CHECK);
2671 // The VM creates & returns objects of this class. Make sure it's initialized.
2672 initialize_class(vmSymbols::java_lang_Class(), CHECK);
2673 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
2674 Handle thread_group = create_initial_thread_group(CHECK);
2675 Universe::set_main_thread_group(thread_group());
2676 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
2677 create_initial_thread(thread_group, main_thread, CHECK);
2678
2679 // The VM creates objects of this class.
2680 initialize_class(vmSymbols::java_lang_Module(), CHECK);
2681
2682 #ifdef ASSERT
2683 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
2684 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
2685 #endif
2686
2687 // initialize the hardware-specific constants needed by Unsafe
2688 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
2689 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
2690
2691 // The VM preresolves methods to these classes. Make sure that they get initialized
2692 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
2693 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
2694
2695 // Phase 1 of the system initialization in the library, java.lang.System class initialization
2696 call_initPhase1(CHECK);
2697
2698 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
2699 // Some values are actually configure-time constants but some can be set via the jlink tool and
2700 // so must be read dynamically. We treat them all the same.
2701 InstanceKlass* ik = SystemDictionary::find_instance_klass(vmSymbols::java_lang_VersionProps(),
2702 Handle(), Handle());
2703 {
2704 ResourceMark rm(main_thread);
2705 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
2706
2707 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
2708
2709 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
2710
2711 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
2712
2713 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
2714 }
2715
2716 // an instance of OutOfMemory exception has been allocated earlier
2717 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
2718 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
2719 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
2720 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
2721 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
2722 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
2723 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
2724 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
2725 }
2726
2727 void Threads::initialize_jsr292_core_classes(TRAPS) {
2728 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
2729
2730 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
2731 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
2732 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
2733 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
2734 }
2735
2736 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2737 extern void JDK_Version_init();
2738
2739 // Preinitialize version info.
2740 VM_Version::early_initialize();
2741
2742 // Check version
2743 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2744
2745 // Initialize library-based TLS
2746 ThreadLocalStorage::init();
2747
2748 // Initialize the output stream module
2749 ostream_init();
2750
2751 // Process java launcher properties.
2752 Arguments::process_sun_java_launcher_properties(args);
2753
2754 // Initialize the os module
2755 os::init();
2756
2757 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
2758
2759 // Record VM creation timing statistics
2760 TraceVmCreationTime create_vm_timer;
2761 create_vm_timer.start();
2762
2763 // Initialize system properties.
2764 Arguments::init_system_properties();
2765
2766 // So that JDK version can be used as a discriminator when parsing arguments
2767 JDK_Version_init();
2768
2769 // Update/Initialize System properties after JDK version number is known
2770 Arguments::init_version_specific_system_properties();
2771
2772 // Make sure to initialize log configuration *before* parsing arguments
2773 LogConfiguration::initialize(create_vm_timer.begin_time());
2774
2775 // Parse arguments
2776 // Note: this internally calls os::init_container_support()
2777 jint parse_result = Arguments::parse(args);
2778 if (parse_result != JNI_OK) return parse_result;
2779
2780 #if INCLUDE_NMT
2781 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
2782 MemTracker::initialize();
2783 #endif // INCLUDE_NMT
2784
2785 os::init_before_ergo();
2786
2787 jint ergo_result = Arguments::apply_ergo();
2788 if (ergo_result != JNI_OK) return ergo_result;
2789
2790 // Final check of all ranges after ergonomics which may change values.
2791 if (!JVMFlagLimit::check_all_ranges()) {
2792 return JNI_EINVAL;
2793 }
2794
2795 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
2796 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
2797 if (!constraint_result) {
2798 return JNI_EINVAL;
2799 }
2800
2801 if (PauseAtStartup) {
2802 os::pause();
2803 }
2804
2805 HOTSPOT_VM_INIT_BEGIN();
2806
2807 // Timing (must come after argument parsing)
2808 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
2809
2810 // Initialize the os module after parsing the args
2811 jint os_init_2_result = os::init_2();
2812 if (os_init_2_result != JNI_OK) return os_init_2_result;
2813
2814 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
2815 // Initialize assert poison page mechanism.
2816 if (ShowRegistersOnAssert) {
2817 initialize_assert_poison();
2818 }
2819 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
2820
2821 SafepointMechanism::initialize();
2822
2823 jint adjust_after_os_result = Arguments::adjust_after_os();
2824 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
2825
2826 // Initialize output stream logging
2827 ostream_init_log();
2828
2829 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2830 // Must be before create_vm_init_agents()
2831 if (Arguments::init_libraries_at_startup()) {
2832 convert_vm_init_libraries_to_agents();
2833 }
2834
2835 // Launch -agentlib/-agentpath and converted -Xrun agents
2836 if (Arguments::init_agents_at_startup()) {
2837 create_vm_init_agents();
2838 }
2839
2840 // Initialize Threads state
2841 _number_of_threads = 0;
2842 _number_of_non_daemon_threads = 0;
2843
2844 // Initialize global data structures and create system classes in heap
2845 vm_init_globals();
2846
2847 #if INCLUDE_JVMCI
2848 if (JVMCICounterSize > 0) {
2849 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
2850 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
2851 } else {
2852 JavaThread::_jvmci_old_thread_counters = NULL;
2853 }
2854 #endif // INCLUDE_JVMCI
2855
2856 // Initialize OopStorage for threadObj
2857 _thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
2858
2859 // Attach the main thread to this os thread
2860 JavaThread* main_thread = new JavaThread();
2861 main_thread->set_thread_state(_thread_in_vm);
2862 main_thread->initialize_thread_current();
2863 // must do this before set_active_handles
2864 main_thread->record_stack_base_and_size();
2865 main_thread->register_thread_stack_with_NMT();
2866 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2867 MACOS_AARCH64_ONLY(main_thread->init_wx());
2868
2869 if (!main_thread->set_as_starting_thread()) {
2870 vm_shutdown_during_initialization(
2871 "Failed necessary internal allocation. Out of swap space");
2872 main_thread->smr_delete();
2873 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2874 return JNI_ENOMEM;
2875 }
2876
2877 // Enable guard page *after* os::create_main_thread(), otherwise it would
2878 // crash Linux VM, see notes in os_linux.cpp.
2879 main_thread->stack_overflow_state()->create_stack_guard_pages();
2880
2881 // Initialize Java-Level synchronization subsystem
2882 ObjectMonitor::Initialize();
2883 ObjectSynchronizer::initialize();
2884
2885 // Initialize global modules
2886 jint status = init_globals();
2887 if (status != JNI_OK) {
2888 main_thread->smr_delete();
2889 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2890 return status;
2891 }
2892
2893 JFR_ONLY(Jfr::on_create_vm_1();)
2894
2895 // Should be done after the heap is fully created
2896 main_thread->cache_global_variables();
2897
2898 { MutexLocker mu(Threads_lock);
2899 Threads::add(main_thread);
2900 }
2901
2902 // Any JVMTI raw monitors entered in onload will transition into
2903 // real raw monitor. VM is setup enough here for raw monitor enter.
2904 JvmtiExport::transition_pending_onload_raw_monitors();
2905
2906 // Create the VMThread
2907 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
2908
2909 VMThread::create();
2910 Thread* vmthread = VMThread::vm_thread();
2911
2912 if (!os::create_thread(vmthread, os::vm_thread)) {
2913 vm_exit_during_initialization("Cannot create VM thread. "
2914 "Out of system resources.");
2915 }
2916
2917 // Wait for the VM thread to become ready, and VMThread::run to initialize
2918 // Monitors can have spurious returns, must always check another state flag
2919 {
2920 MonitorLocker ml(Notify_lock);
2921 os::start_thread(vmthread);
2922 while (vmthread->active_handles() == NULL) {
2923 ml.wait();
2924 }
2925 }
2926 }
2927
2928 assert(Universe::is_fully_initialized(), "not initialized");
2929 if (VerifyDuringStartup) {
2930 // Make sure we're starting with a clean slate.
2931 VM_Verify verify_op;
2932 VMThread::execute(&verify_op);
2933 }
2934
2935 // We need this to update the java.vm.info property in case any flags used
2936 // to initially define it have been changed. This is needed for both CDS
2937 // since UseSharedSpaces may be changed after java.vm.info
2938 // is initially computed. See Abstract_VM_Version::vm_info_string().
2939 // This update must happen before we initialize the java classes, but
2940 // after any initialization logic that might modify the flags.
2941 Arguments::update_vm_info_property(VM_Version::vm_info_string());
2942
2943 JavaThread* THREAD = JavaThread::current(); // For exception macros.
2944 HandleMark hm(THREAD);
2945
2946 // Always call even when there are not JVMTI environments yet, since environments
2947 // may be attached late and JVMTI must track phases of VM execution
2948 JvmtiExport::enter_early_start_phase();
2949
2950 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
2951 JvmtiExport::post_early_vm_start();
2952
2953 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
2954
2955 quicken_jni_functions();
2956
2957 // No more stub generation allowed after that point.
2958 StubCodeDesc::freeze();
2959
2960 // Set flag that basic initialization has completed. Used by exceptions and various
2961 // debug stuff, that does not work until all basic classes have been initialized.
2962 set_init_completed();
2963
2964 LogConfiguration::post_initialize();
2965 Metaspace::post_initialize();
2966
2967 HOTSPOT_VM_INIT_END();
2968
2969 // record VM initialization completion time
2970 #if INCLUDE_MANAGEMENT
2971 Management::record_vm_init_completed();
2972 #endif // INCLUDE_MANAGEMENT
2973
2974 // Signal Dispatcher needs to be started before VMInit event is posted
2975 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
2976
2977 // Start Attach Listener if +StartAttachListener or it can't be started lazily
2978 if (!DisableAttachMechanism) {
2979 AttachListener::vm_start();
2980 if (StartAttachListener || AttachListener::init_at_startup()) {
2981 AttachListener::init();
2982 }
2983 }
2984
2985 // Launch -Xrun agents
2986 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
2987 // back-end can launch with -Xdebug -Xrunjdwp.
2988 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
2989 create_vm_init_libraries();
2990 }
2991
2992 Chunk::start_chunk_pool_cleaner_task();
2993
2994 // Start the service thread
2995 // The service thread enqueues JVMTI deferred events and does various hashtable
2996 // and other cleanups. Needs to start before the compilers start posting events.
2997 ServiceThread::initialize();
2998
2999 // Start the monitor deflation thread:
3000 MonitorDeflationThread::initialize();
3001
3002 // initialize compiler(s)
3003 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
3004 #if INCLUDE_JVMCI
3005 bool force_JVMCI_intialization = false;
3006 if (EnableJVMCI) {
3007 // Initialize JVMCI eagerly when it is explicitly requested.
3008 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
3009 force_JVMCI_intialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
3010
3011 if (!force_JVMCI_intialization) {
3012 // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking
3013 // compilations via JVMCI will not actually block until JVMCI is initialized.
3014 force_JVMCI_intialization = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation);
3015 }
3016 }
3017 #endif
3018 CompileBroker::compilation_init_phase1(CHECK_JNI_ERR);
3019 // Postpone completion of compiler initialization to after JVMCI
3020 // is initialized to avoid timeouts of blocking compilations.
3021 if (JVMCI_ONLY(!force_JVMCI_intialization) NOT_JVMCI(true)) {
3022 CompileBroker::compilation_init_phase2();
3023 }
3024 #endif
3025
3026 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
3027 // It is done after compilers are initialized, because otherwise compilations of
3028 // signature polymorphic MH intrinsics can be missed
3029 // (see SystemDictionary::find_method_handle_intrinsic).
3030 initialize_jsr292_core_classes(CHECK_JNI_ERR);
3031
3032 // This will initialize the module system. Only java.base classes can be
3033 // loaded until phase 2 completes
3034 call_initPhase2(CHECK_JNI_ERR);
3035
3036 JFR_ONLY(Jfr::on_create_vm_2();)
3037
3038 // Always call even when there are not JVMTI environments yet, since environments
3039 // may be attached late and JVMTI must track phases of VM execution
3040 JvmtiExport::enter_start_phase();
3041
3042 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3043 JvmtiExport::post_vm_start();
3044
3045 // Final system initialization including security manager and system class loader
3046 call_initPhase3(CHECK_JNI_ERR);
3047
3048 // cache the system and platform class loaders
3049 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
3050
3051 #if INCLUDE_CDS
3052 // capture the module path info from the ModuleEntryTable
3053 ClassLoader::initialize_module_path(THREAD);
3054 if (HAS_PENDING_EXCEPTION) {
3055 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
3056 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
3057 }
3058 #endif
3059
3060 #if INCLUDE_JVMCI
3061 if (force_JVMCI_intialization) {
3062 JVMCI::initialize_compiler(CHECK_JNI_ERR);
3063 CompileBroker::compilation_init_phase2();
3064 }
3065 #endif
3066
3067 // Always call even when there are not JVMTI environments yet, since environments
3068 // may be attached late and JVMTI must track phases of VM execution
3069 JvmtiExport::enter_live_phase();
3070
3071 // Make perfmemory accessible
3072 PerfMemory::set_accessible(true);
3073
3074 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3075 JvmtiExport::post_vm_initialized();
3076
3077 JFR_ONLY(Jfr::on_create_vm_3();)
3078
3079 #if INCLUDE_MANAGEMENT
3080 Management::initialize(THREAD);
3081
3082 if (HAS_PENDING_EXCEPTION) {
3083 // management agent fails to start possibly due to
3084 // configuration problem and is responsible for printing
3085 // stack trace if appropriate. Simply exit VM.
3086 vm_exit(1);
3087 }
3088 #endif // INCLUDE_MANAGEMENT
3089
3090 StatSampler::engage();
3091 if (CheckJNICalls) JniPeriodicChecker::engage();
3092
3093 BiasedLocking::init();
3094
3095 #if INCLUDE_RTM_OPT
3096 RTMLockingCounters::init();
3097 #endif
3098
3099 call_postVMInitHook(THREAD);
3100 // The Java side of PostVMInitHook.run must deal with all
3101 // exceptions and provide means of diagnosis.
3102 if (HAS_PENDING_EXCEPTION) {
3103 CLEAR_PENDING_EXCEPTION;
3104 }
3105
3106 {
3107 MutexLocker ml(PeriodicTask_lock);
3108 // Make sure the WatcherThread can be started by WatcherThread::start()
3109 // or by dynamic enrollment.
3110 WatcherThread::make_startable();
3111 // Start up the WatcherThread if there are any periodic tasks
3112 // NOTE: All PeriodicTasks should be registered by now. If they
3113 // aren't, late joiners might appear to start slowly (we might
3114 // take a while to process their first tick).
3115 if (PeriodicTask::num_tasks() > 0) {
3116 WatcherThread::start();
3117 }
3118 }
3119
3120 create_vm_timer.end();
3121 #ifdef ASSERT
3122 _vm_complete = true;
3123 #endif
3124
3125 if (DumpSharedSpaces) {
3126 MetaspaceShared::preload_and_dump();
3127 ShouldNotReachHere();
3128 }
3129
3130 return JNI_OK;
3131 }
3132
3133 // type for the Agent_OnLoad and JVM_OnLoad entry points
3134 extern "C" {
3135 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3136 }
3137 // Find a command line agent library and return its entry point for
3138 // -agentlib: -agentpath: -Xrun
3139 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3140 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent,
3141 const char *on_load_symbols[],
3142 size_t num_symbol_entries) {
3143 OnLoadEntry_t on_load_entry = NULL;
3144 void *library = NULL;
3145
3146 if (!agent->valid()) {
3147 char buffer[JVM_MAXPATHLEN];
3148 char ebuf[1024] = "";
3149 const char *name = agent->name();
3150 const char *msg = "Could not find agent library ";
3151
3152 // First check to see if agent is statically linked into executable
3153 if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
3154 library = agent->os_lib();
3155 } else if (agent->is_absolute_path()) {
3156 library = os::dll_load(name, ebuf, sizeof ebuf);
3157 if (library == NULL) {
3158 const char *sub_msg = " in absolute path, with error: ";
3159 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3160 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3161 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3162 // If we can't find the agent, exit.
3163 vm_exit_during_initialization(buf, NULL);
3164 FREE_C_HEAP_ARRAY(char, buf);
3165 }
3166 } else {
3167 // Try to load the agent from the standard dll directory
3168 if (os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
3169 name)) {
3170 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3171 }
3172 if (library == NULL) { // Try the library path directory.
3173 if (os::dll_build_name(buffer, sizeof(buffer), name)) {
3174 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3175 }
3176 if (library == NULL) {
3177 const char *sub_msg = " on the library path, with error: ";
3178 const char *sub_msg2 = "\nModule java.instrument may be missing from runtime image.";
3179
3180 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) +
3181 strlen(ebuf) + strlen(sub_msg2) + 1;
3182 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3183 if (!agent->is_instrument_lib()) {
3184 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3185 } else {
3186 jio_snprintf(buf, len, "%s%s%s%s%s", msg, name, sub_msg, ebuf, sub_msg2);
3187 }
3188 // If we can't find the agent, exit.
3189 vm_exit_during_initialization(buf, NULL);
3190 FREE_C_HEAP_ARRAY(char, buf);
3191 }
3192 }
3193 }
3194 agent->set_os_lib(library);
3195 agent->set_valid();
3196 }
3197
3198 // Find the OnLoad function.
3199 on_load_entry =
3200 CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
3201 false,
3202 on_load_symbols,
3203 num_symbol_entries));
3204 return on_load_entry;
3205 }
3206
3207 // Find the JVM_OnLoad entry point
3208 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3209 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3210 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3211 }
3212
3213 // Find the Agent_OnLoad entry point
3214 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3215 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3216 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3217 }
3218
3219 // For backwards compatibility with -Xrun
3220 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3221 // treated like -agentpath:
3222 // Must be called before agent libraries are created
3223 void Threads::convert_vm_init_libraries_to_agents() {
3224 AgentLibrary* agent;
3225 AgentLibrary* next;
3226
3227 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3228 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3229 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3230
3231 // If there is an JVM_OnLoad function it will get called later,
3232 // otherwise see if there is an Agent_OnLoad
3233 if (on_load_entry == NULL) {
3234 on_load_entry = lookup_agent_on_load(agent);
3235 if (on_load_entry != NULL) {
3236 // switch it to the agent list -- so that Agent_OnLoad will be called,
3237 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3238 Arguments::convert_library_to_agent(agent);
3239 } else {
3240 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3241 }
3242 }
3243 }
3244 }
3245
3246 // Create agents for -agentlib: -agentpath: and converted -Xrun
3247 // Invokes Agent_OnLoad
3248 // Called very early -- before JavaThreads exist
3249 void Threads::create_vm_init_agents() {
3250 extern struct JavaVM_ main_vm;
3251 AgentLibrary* agent;
3252
3253 JvmtiExport::enter_onload_phase();
3254
3255 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3256 // CDS dumping does not support native JVMTI agent.
3257 // CDS dumping supports Java agent if the AllowArchivingWithJavaAgent diagnostic option is specified.
3258 if (Arguments::is_dumping_archive()) {
3259 if(!agent->is_instrument_lib()) {
3260 vm_exit_during_cds_dumping("CDS dumping does not support native JVMTI agent, name", agent->name());
3261 } else if (!AllowArchivingWithJavaAgent) {
3262 vm_exit_during_cds_dumping(
3263 "Must enable AllowArchivingWithJavaAgent in order to run Java agent during CDS dumping");
3264 }
3265 }
3266
3267 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3268
3269 if (on_load_entry != NULL) {
3270 // Invoke the Agent_OnLoad function
3271 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3272 if (err != JNI_OK) {
3273 vm_exit_during_initialization("agent library failed to init", agent->name());
3274 }
3275 } else {
3276 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3277 }
3278 }
3279
3280 JvmtiExport::enter_primordial_phase();
3281 }
3282
3283 extern "C" {
3284 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3285 }
3286
3287 void Threads::shutdown_vm_agents() {
3288 // Send any Agent_OnUnload notifications
3289 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3290 size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
3291 extern struct JavaVM_ main_vm;
3292 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3293
3294 // Find the Agent_OnUnload function.
3295 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3296 os::find_agent_function(agent,
3297 false,
3298 on_unload_symbols,
3299 num_symbol_entries));
3300
3301 // Invoke the Agent_OnUnload function
3302 if (unload_entry != NULL) {
3303 JavaThread* thread = JavaThread::current();
3304 ThreadToNativeFromVM ttn(thread);
3305 HandleMark hm(thread);
3306 (*unload_entry)(&main_vm);
3307 }
3308 }
3309 }
3310
3311 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3312 // Invokes JVM_OnLoad
3313 void Threads::create_vm_init_libraries() {
3314 extern struct JavaVM_ main_vm;
3315 AgentLibrary* agent;
3316
3317 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3318 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3319
3320 if (on_load_entry != NULL) {
3321 // Invoke the JVM_OnLoad function
3322 JavaThread* thread = JavaThread::current();
3323 ThreadToNativeFromVM ttn(thread);
3324 HandleMark hm(thread);
3325 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3326 if (err != JNI_OK) {
3327 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3328 }
3329 } else {
3330 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3331 }
3332 }
3333 }
3334
3335
3336 // Last thread running calls java.lang.Shutdown.shutdown()
3337 void JavaThread::invoke_shutdown_hooks() {
3338 HandleMark hm(this);
3339
3340 // We could get here with a pending exception, if so clear it now or
3341 // it will cause MetaspaceShared::link_and_cleanup_shared_classes to
3342 // fail for dynamic dump.
3343 if (this->has_pending_exception()) {
3344 this->clear_pending_exception();
3345 }
3346
3347 #if INCLUDE_CDS
3348 // Link all classes for dynamic CDS dumping before vm exit.
3349 // Same operation is being done in JVM_BeforeHalt for handling the
3350 // case where the application calls System.exit().
3351 if (DynamicDumpSharedSpaces) {
3352 DynamicArchive::prepare_for_dynamic_dumping_at_exit();
3353 }
3354 #endif
3355
3356 EXCEPTION_MARK;
3357 Klass* shutdown_klass =
3358 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3359 THREAD);
3360 if (shutdown_klass != NULL) {
3361 // SystemDictionary::resolve_or_null will return null if there was
3362 // an exception. If we cannot load the Shutdown class, just don't
3363 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3364 // won't be run. Note that if a shutdown hook was registered,
3365 // the Shutdown class would have already been loaded
3366 // (Runtime.addShutdownHook will load it).
3367 JavaValue result(T_VOID);
3368 JavaCalls::call_static(&result,
3369 shutdown_klass,
3370 vmSymbols::shutdown_name(),
3371 vmSymbols::void_method_signature(),
3372 THREAD);
3373 }
3374 CLEAR_PENDING_EXCEPTION;
3375 }
3376
3377 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3378 // the program falls off the end of main(). Another VM exit path is through
3379 // vm_exit() when the program calls System.exit() to return a value or when
3380 // there is a serious error in VM. The two shutdown paths are not exactly
3381 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3382 // and VM_Exit op at VM level.
3383 //
3384 // Shutdown sequence:
3385 // + Shutdown native memory tracking if it is on
3386 // + Wait until we are the last non-daemon thread to execute
3387 // <-- every thing is still working at this moment -->
3388 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3389 // shutdown hooks
3390 // + Call before_exit(), prepare for VM exit
3391 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3392 // currently the only user of this mechanism is File.deleteOnExit())
3393 // > stop StatSampler, watcher thread,
3394 // post thread end and vm death events to JVMTI,
3395 // stop signal thread
3396 // + Call JavaThread::exit(), it will:
3397 // > release JNI handle blocks, remove stack guard pages
3398 // > remove this thread from Threads list
3399 // <-- no more Java code from this thread after this point -->
3400 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3401 // the compiler threads at safepoint
3402 // <-- do not use anything that could get blocked by Safepoint -->
3403 // + Disable tracing at JNI/JVM barriers
3404 // + Set _vm_exited flag for threads that are still running native code
3405 // + Call exit_globals()
3406 // > deletes tty
3407 // > deletes PerfMemory resources
3408 // + Delete this thread
3409 // + Return to caller
3410
3411 void Threads::destroy_vm() {
3412 JavaThread* thread = JavaThread::current();
3413
3414 #ifdef ASSERT
3415 _vm_complete = false;
3416 #endif
3417 // Wait until we are the last non-daemon thread to execute
3418 {
3419 MonitorLocker nu(Threads_lock);
3420 while (Threads::number_of_non_daemon_threads() > 1)
3421 // This wait should make safepoint checks, wait without a timeout.
3422 nu.wait(0);
3423 }
3424
3425 EventShutdown e;
3426 if (e.should_commit()) {
3427 e.set_reason("No remaining non-daemon Java threads");
3428 e.commit();
3429 }
3430
3431 // Hang forever on exit if we are reporting an error.
3432 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
3433 os::infinite_sleep();
3434 }
3435 os::wait_for_keypress_at_exit();
3436
3437 // run Java level shutdown hooks
3438 thread->invoke_shutdown_hooks();
3439
3440 before_exit(thread);
3441
3442 thread->exit(true);
3443
3444 // We are no longer on the main thread list but could still be in a
3445 // secondary list where another thread may try to interact with us.
3446 // So wait until all such interactions are complete before we bring
3447 // the VM to the termination safepoint. Normally this would be done
3448 // using thread->smr_delete() below where we delete the thread, but
3449 // we can't call that after the termination safepoint is active as
3450 // we will deadlock on the Threads_lock. Once all interactions are
3451 // complete it is safe to directly delete the thread at any time.
3452 ThreadsSMRSupport::wait_until_not_protected(thread);
3453
3454 // Stop VM thread.
3455 {
3456 // 4945125 The vm thread comes to a safepoint during exit.
3457 // GC vm_operations can get caught at the safepoint, and the
3458 // heap is unparseable if they are caught. Grab the Heap_lock
3459 // to prevent this. The GC vm_operations will not be able to
3460 // queue until after the vm thread is dead. After this point,
3461 // we'll never emerge out of the safepoint before the VM exits.
3462 // Assert that the thread is terminated so that acquiring the
3463 // Heap_lock doesn't cause the terminated thread to participate in
3464 // the safepoint protocol.
3465
3466 assert(thread->is_terminated(), "must be terminated here");
3467 MutexLocker ml(Heap_lock);
3468
3469 VMThread::wait_for_vm_thread_exit();
3470 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3471 VMThread::destroy();
3472 }
3473
3474 // Now, all Java threads are gone except daemon threads. Daemon threads
3475 // running Java code or in VM are stopped by the Safepoint. However,
3476 // daemon threads executing native code are still running. But they
3477 // will be stopped at native=>Java/VM barriers. Note that we can't
3478 // simply kill or suspend them, as it is inherently deadlock-prone.
3479
3480 VM_Exit::set_vm_exited();
3481
3482 // Clean up ideal graph printers after the VMThread has started
3483 // the final safepoint which will block all the Compiler threads.
3484 // Note that this Thread has already logically exited so the
3485 // clean_up() function's use of a JavaThreadIteratorWithHandle
3486 // would be a problem except set_vm_exited() has remembered the
3487 // shutdown thread which is granted a policy exception.
3488 #if defined(COMPILER2) && !defined(PRODUCT)
3489 IdealGraphPrinter::clean_up();
3490 #endif
3491
3492 notify_vm_shutdown();
3493
3494 // exit_globals() will delete tty
3495 exit_globals();
3496
3497 // Deleting the shutdown thread here is safe. See comment on
3498 // wait_until_not_protected() above.
3499 delete thread;
3500
3501 #if INCLUDE_JVMCI
3502 if (JVMCICounterSize > 0) {
3503 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
3504 }
3505 #endif
3506
3507 LogConfiguration::finalize();
3508 }
3509
3510
3511 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3512 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3513 return is_supported_jni_version(version);
3514 }
3515
3516
3517 jboolean Threads::is_supported_jni_version(jint version) {
3518 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3519 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3520 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3521 if (version == JNI_VERSION_1_8) return JNI_TRUE;
3522 if (version == JNI_VERSION_9) return JNI_TRUE;
3523 if (version == JNI_VERSION_10) return JNI_TRUE;
3524 return JNI_FALSE;
3525 }
3526
3527
3528 void Threads::add(JavaThread* p, bool force_daemon) {
3529 // The threads lock must be owned at this point
3530 assert(Threads_lock->owned_by_self(), "must have threads lock");
3531
3532 BarrierSet::barrier_set()->on_thread_attach(p);
3533
3534 // Once a JavaThread is added to the Threads list, smr_delete() has
3535 // to be used to delete it. Otherwise we can just delete it directly.
3536 p->set_on_thread_list();
3537
3538 _number_of_threads++;
3539 oop threadObj = p->threadObj();
3540 bool daemon = true;
3541 // Bootstrapping problem: threadObj can be null for initial
3542 // JavaThread (or for threads attached via JNI)
3543 if ((!force_daemon) && !is_daemon((threadObj))) {
3544 _number_of_non_daemon_threads++;
3545 daemon = false;
3546 }
3547
3548 ThreadService::add_thread(p, daemon);
3549
3550 // Maintain fast thread list
3551 ThreadsSMRSupport::add_thread(p);
3552
3553 // Increase the ObjectMonitor ceiling for the new thread.
3554 ObjectSynchronizer::inc_in_use_list_ceiling();
3555
3556 // Possible GC point.
3557 Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
3558
3559 // Make new thread known to active EscapeBarrier
3560 EscapeBarrier::thread_added(p);
3561 }
3562
3563 void Threads::remove(JavaThread* p, bool is_daemon) {
3564 // Extra scope needed for Thread_lock, so we can check
3565 // that we do not remove thread without safepoint code notice
3566 { MonitorLocker ml(Threads_lock);
3567
3568 // BarrierSet state must be destroyed after the last thread transition
3569 // before the thread terminates. Thread transitions result in calls to
3570 // StackWatermarkSet::on_safepoint(), which performs GC processing,
3571 // requiring the GC state to be alive.
3572 BarrierSet::barrier_set()->on_thread_detach(p);
3573
3574 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
3575
3576 // Maintain fast thread list
3577 ThreadsSMRSupport::remove_thread(p);
3578
3579 _number_of_threads--;
3580 if (!is_daemon) {
3581 _number_of_non_daemon_threads--;
3582
3583 // Only one thread left, do a notify on the Threads_lock so a thread waiting
3584 // on destroy_vm will wake up.
3585 if (number_of_non_daemon_threads() == 1) {
3586 ml.notify_all();
3587 }
3588 }
3589 ThreadService::remove_thread(p, is_daemon);
3590
3591 // Make sure that safepoint code disregard this thread. This is needed since
3592 // the thread might mess around with locks after this point. This can cause it
3593 // to do callbacks into the safepoint code. However, the safepoint code is not aware
3594 // of this thread since it is removed from the queue.
3595 p->set_terminated(JavaThread::_thread_terminated);
3596
3597 // Notify threads waiting in EscapeBarriers
3598 EscapeBarrier::thread_removed(p);
3599 } // unlock Threads_lock
3600
3601 // Reduce the ObjectMonitor ceiling for the exiting thread.
3602 ObjectSynchronizer::dec_in_use_list_ceiling();
3603
3604 // Since Events::log uses a lock, we grab it outside the Threads_lock
3605 Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
3606 }
3607
3608 // Operations on the Threads list for GC. These are not explicitly locked,
3609 // but the garbage collector must provide a safe context for them to run.
3610 // In particular, these things should never be called when the Threads_lock
3611 // is held by some other thread. (Note: the Safepoint abstraction also
3612 // uses the Threads_lock to guarantee this property. It also makes sure that
3613 // all threads gets blocked when exiting or starting).
3614
3615 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3616 ALL_JAVA_THREADS(p) {
3617 p->oops_do(f, cf);
3618 }
3619 VMThread::vm_thread()->oops_do(f, cf);
3620 }
3621
3622 void Threads::change_thread_claim_token() {
3623 if (++_thread_claim_token == 0) {
3624 // On overflow of the token counter, there is a risk of future
3625 // collisions between a new global token value and a stale token
3626 // for a thread, because not all iterations visit all threads.
3627 // (Though it's pretty much a theoretical concern for non-trivial
3628 // token counter sizes.) To deal with the possibility, reset all
3629 // the thread tokens to zero on global token overflow.
3630 struct ResetClaims : public ThreadClosure {
3631 virtual void do_thread(Thread* t) {
3632 t->claim_threads_do(false, 0);
3633 }
3634 } reset_claims;
3635 Threads::threads_do(&reset_claims);
3636 // On overflow, update the global token to non-zero, to
3637 // avoid the special "never claimed" initial thread value.
3638 _thread_claim_token = 1;
3639 }
3640 }
3641
3642 #ifdef ASSERT
3643 void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
3644 const uintx token = t->threads_do_token();
3645 assert(token == expected,
3646 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
3647 UINTX_FORMAT, kind, p2i(t), token, expected);
3648 }
3649
3650 void Threads::assert_all_threads_claimed() {
3651 ALL_JAVA_THREADS(p) {
3652 assert_thread_claimed("Thread", p, _thread_claim_token);
3653 }
3654 assert_thread_claimed("VMThread", VMThread::vm_thread(), _thread_claim_token);
3655 }
3656 #endif // ASSERT
3657
3658 class ParallelOopsDoThreadClosure : public ThreadClosure {
3659 private:
3660 OopClosure* _f;
3661 CodeBlobClosure* _cf;
3662 public:
3663 ParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf) : _f(f), _cf(cf) {}
3664 void do_thread(Thread* t) {
3665 t->oops_do(_f, _cf);
3666 }
3667 };
3668
3669 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) {
3670 ParallelOopsDoThreadClosure tc(f, cf);
3671 possibly_parallel_threads_do(is_par, &tc);
3672 }
3673
3674 void Threads::metadata_do(MetadataClosure* f) {
3675 ALL_JAVA_THREADS(p) {
3676 p->metadata_do(f);
3677 }
3678 }
3679
3680 class ThreadHandlesClosure : public ThreadClosure {
3681 void (*_f)(Metadata*);
3682 public:
3683 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
3684 virtual void do_thread(Thread* thread) {
3685 thread->metadata_handles_do(_f);
3686 }
3687 };
3688
3689 void Threads::metadata_handles_do(void f(Metadata*)) {
3690 // Only walk the Handles in Thread.
3691 ThreadHandlesClosure handles_closure(f);
3692 threads_do(&handles_closure);
3693 }
3694
3695 // Get count Java threads that are waiting to enter the specified monitor.
3696 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
3697 int count,
3698 address monitor) {
3699 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
3700
3701 int i = 0;
3702 DO_JAVA_THREADS(t_list, p) {
3703 if (!p->can_call_java()) continue;
3704
3705 // The first stage of async deflation does not affect any field
3706 // used by this comparison so the ObjectMonitor* is usable here.
3707 address pending = (address)p->current_pending_monitor();
3708 if (pending == monitor) { // found a match
3709 if (i < count) result->append(p); // save the first count matches
3710 i++;
3711 }
3712 }
3713
3714 return result;
3715 }
3716
3717
3718 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
3719 address owner) {
3720 assert(!UseFastLocking, "only with stack-locking");
3721 // NULL owner means not locked so we can skip the search
3722 if (owner == NULL) return NULL;
3723
3724 DO_JAVA_THREADS(t_list, p) {
3725 // first, see if owner is the address of a Java thread
3726 if (owner == (address)p) return p;
3727 }
3728
3729 // Cannot assert on lack of success here since this function may be
3730 // used by code that is trying to report useful problem information
3731 // like deadlock detection.
3732 if (UseHeavyMonitors) return NULL;
3733
3734 // If we didn't find a matching Java thread and we didn't force use of
3735 // heavyweight monitors, then the owner is the stack address of the
3736 // Lock Word in the owning Java thread's stack.
3737 //
3738 JavaThread* the_owner = NULL;
3739 DO_JAVA_THREADS(t_list, q) {
3740 if (q->is_lock_owned(owner)) {
3741 the_owner = q;
3742 break;
3743 }
3744 }
3745
3746 // cannot assert on lack of success here; see above comment
3747 return the_owner;
3748 }
3749
3750 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
3751 assert(UseFastLocking, "Only with fast-locking");
3752 DO_JAVA_THREADS(t_list, q) {
3753 if (q->lock_stack().contains(obj)) {
3754 return q;
3755 }
3756 }
3757 return NULL;
3758 }
3759
3760 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
3761 if (UseFastLocking) {
3762 void* raw_owner = monitor->owner_raw();
3763 if (raw_owner == ANONYMOUS_OWNER) {
3764 return owning_thread_from_object(t_list, monitor->object());
3765 } else if (raw_owner == DEFLATER_MARKER) {
3766 return NULL;
3767 } else {
3768 Thread* owner = reinterpret_cast<Thread*>(raw_owner);
3769 #ifdef ASSERT
3770 if (owner != NULL) {
3771 bool found = false;
3772 DO_JAVA_THREADS(t_list, q) {
3773 if (q == owner) {
3774 found = true;;
3775 break;
3776 }
3777 }
3778 assert(found, "owner is not a thread: " PTR_FORMAT, p2i(owner));
3779 }
3780 #endif
3781 assert(owner == NULL || owner->is_Java_thread(), "only JavaThreads own monitors");
3782 return reinterpret_cast<JavaThread*>(owner);
3783 }
3784 } else {
3785 return owning_thread_from_monitor_owner(t_list, (address)monitor->owner());
3786 }
3787 }
3788
3789 class PrintOnClosure : public ThreadClosure {
3790 private:
3791 outputStream* _st;
3792
3793 public:
3794 PrintOnClosure(outputStream* st) :
3795 _st(st) {}
3796
3797 virtual void do_thread(Thread* thread) {
3798 if (thread != NULL) {
3799 thread->print_on(_st);
3800 _st->cr();
3801 }
3802 }
3803 };
3804
3805 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
3806 void Threads::print_on(outputStream* st, bool print_stacks,
3807 bool internal_format, bool print_concurrent_locks,
3808 bool print_extended_info) {
3809 char buf[32];
3810 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
3811
3812 st->print_cr("Full thread dump %s (%s %s):",
3813 VM_Version::vm_name(),
3814 VM_Version::vm_release(),
3815 VM_Version::vm_info_string());
3816 st->cr();
3817
3818 #if INCLUDE_SERVICES
3819 // Dump concurrent locks
3820 ConcurrentLocksDump concurrent_locks;
3821 if (print_concurrent_locks) {
3822 concurrent_locks.dump_at_safepoint();
3823 }
3824 #endif // INCLUDE_SERVICES
3825
3826 ThreadsSMRSupport::print_info_on(st);
3827 st->cr();
3828
3829 ALL_JAVA_THREADS(p) {
3830 ResourceMark rm;
3831 p->print_on(st, print_extended_info);
3832 if (print_stacks) {
3833 if (internal_format) {
3834 p->trace_stack();
3835 } else {
3836 p->print_stack_on(st);
3837 }
3838 }
3839 st->cr();
3840 #if INCLUDE_SERVICES
3841 if (print_concurrent_locks) {
3842 concurrent_locks.print_locks_on(p, st);
3843 }
3844 #endif // INCLUDE_SERVICES
3845 }
3846
3847 PrintOnClosure cl(st);
3848 cl.do_thread(VMThread::vm_thread());
3849 Universe::heap()->gc_threads_do(&cl);
3850 if (StringDedup::is_enabled()) {
3851 StringDedup::threads_do(&cl);
3852 }
3853 cl.do_thread(WatcherThread::watcher_thread());
3854 cl.do_thread(AsyncLogWriter::instance());
3855
3856 st->flush();
3857 }
3858
3859 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
3860 int buflen, bool* found_current) {
3861 if (this_thread != NULL) {
3862 bool is_current = (current == this_thread);
3863 *found_current = *found_current || is_current;
3864 st->print("%s", is_current ? "=>" : " ");
3865
3866 st->print(PTR_FORMAT, p2i(this_thread));
3867 st->print(" ");
3868 this_thread->print_on_error(st, buf, buflen);
3869 st->cr();
3870 }
3871 }
3872
3873 class PrintOnErrorClosure : public ThreadClosure {
3874 outputStream* _st;
3875 Thread* _current;
3876 char* _buf;
3877 int _buflen;
3878 bool* _found_current;
3879 public:
3880 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
3881 int buflen, bool* found_current) :
3882 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
3883
3884 virtual void do_thread(Thread* thread) {
3885 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
3886 }
3887 };
3888
3889 // Threads::print_on_error() is called by fatal error handler. It's possible
3890 // that VM is not at safepoint and/or current thread is inside signal handler.
3891 // Don't print stack trace, as the stack may not be walkable. Don't allocate
3892 // memory (even in resource area), it might deadlock the error handler.
3893 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
3894 int buflen) {
3895 ThreadsSMRSupport::print_info_on(st);
3896 st->cr();
3897
3898 bool found_current = false;
3899 st->print_cr("Java Threads: ( => current thread )");
3900 ALL_JAVA_THREADS(thread) {
3901 print_on_error(thread, st, current, buf, buflen, &found_current);
3902 }
3903 st->cr();
3904
3905 st->print_cr("Other Threads:");
3906 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
3907 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
3908 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
3909
3910 if (Universe::heap() != NULL) {
3911 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
3912 Universe::heap()->gc_threads_do(&print_closure);
3913 }
3914
3915 if (StringDedup::is_enabled()) {
3916 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
3917 StringDedup::threads_do(&print_closure);
3918 }
3919
3920 if (!found_current) {
3921 st->cr();
3922 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
3923 current->print_on_error(st, buf, buflen);
3924 st->cr();
3925 }
3926 st->cr();
3927
3928 st->print_cr("Threads with active compile tasks:");
3929 print_threads_compiling(st, buf, buflen);
3930 }
3931
3932 void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
3933 ALL_JAVA_THREADS(thread) {
3934 if (thread->is_Compiler_thread()) {
3935 CompilerThread* ct = (CompilerThread*) thread;
3936
3937 // Keep task in local variable for NULL check.
3938 // ct->_task might be set to NULL by concurring compiler thread
3939 // because it completed the compilation. The task is never freed,
3940 // though, just returned to a free list.
3941 CompileTask* task = ct->task();
3942 if (task != NULL) {
3943 thread->print_name_on_error(st, buf, buflen);
3944 st->print(" ");
3945 task->print(st, NULL, short_form, true);
3946 }
3947 }
3948 }
3949 }
3950
3951
3952 // Ad-hoc mutual exclusion primitives: SpinLock
3953 //
3954 // We employ SpinLocks _only for low-contention, fixed-length
3955 // short-duration critical sections where we're concerned
3956 // about native mutex_t or HotSpot Mutex:: latency.
3957 //
3958 // TODO-FIXME: ListLock should be of type SpinLock.
3959 // We should make this a 1st-class type, integrated into the lock
3960 // hierarchy as leaf-locks. Critically, the SpinLock structure
3961 // should have sufficient padding to avoid false-sharing and excessive
3962 // cache-coherency traffic.
3963
3964
3965 typedef volatile int SpinLockT;
3966
3967 void Thread::SpinAcquire(volatile int * adr, const char * LockName) {
3968 if (Atomic::cmpxchg(adr, 0, 1) == 0) {
3969 return; // normal fast-path return
3970 }
3971
3972 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
3973 int ctr = 0;
3974 int Yields = 0;
3975 for (;;) {
3976 while (*adr != 0) {
3977 ++ctr;
3978 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
3979 if (Yields > 5) {
3980 os::naked_short_sleep(1);
3981 } else {
3982 os::naked_yield();
3983 ++Yields;
3984 }
3985 } else {
3986 SpinPause();
3987 }
3988 }
3989 if (Atomic::cmpxchg(adr, 0, 1) == 0) return;
3990 }
3991 }
3992
3993 void Thread::SpinRelease(volatile int * adr) {
3994 assert(*adr != 0, "invariant");
3995 OrderAccess::fence(); // guarantee at least release consistency.
3996 // Roach-motel semantics.
3997 // It's safe if subsequent LDs and STs float "up" into the critical section,
3998 // but prior LDs and STs within the critical section can't be allowed
3999 // to reorder or float past the ST that releases the lock.
4000 // Loads and stores in the critical section - which appear in program
4001 // order before the store that releases the lock - must also appear
4002 // before the store that releases the lock in memory visibility order.
4003 // Conceptually we need a #loadstore|#storestore "release" MEMBAR before
4004 // the ST of 0 into the lock-word which releases the lock, so fence
4005 // more than covers this on all platforms.
4006 *adr = 0;
4007 }
4008
4009
4010 void Threads::verify() {
4011 ALL_JAVA_THREADS(p) {
4012 p->verify();
4013 }
4014 VMThread* thread = VMThread::vm_thread();
4015 if (thread != NULL) thread->verify();
4016 }
4017
4018 #ifndef PRODUCT
4019 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
4020 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
4021 }
4022 #endif