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