1 /*
2 * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "jvm.h"
28 #include "cds/dynamicArchive.hpp"
29 #include "cds/metaspaceShared.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/javaClasses.hpp"
32 #include "classfile/javaThreadStatus.hpp"
33 #include "classfile/systemDictionary.hpp"
34 #include "classfile/vmClasses.hpp"
35 #include "classfile/vmSymbols.hpp"
36 #include "code/codeCache.hpp"
37 #include "code/scopeDesc.hpp"
38 #include "compiler/compileBroker.hpp"
39 #include "compiler/compileTask.hpp"
40 #include "compiler/compilerThread.hpp"
41 #include "gc/shared/barrierSet.hpp"
42 #include "gc/shared/collectedHeap.hpp"
43 #include "gc/shared/gcId.hpp"
44 #include "gc/shared/gcLocker.inline.hpp"
45 #include "gc/shared/gcVMOperations.hpp"
46 #include "gc/shared/oopStorage.hpp"
47 #include "gc/shared/oopStorageSet.hpp"
48 #include "gc/shared/stringdedup/stringDedup.hpp"
49 #include "gc/shared/tlab_globals.hpp"
50 #include "interpreter/interpreter.hpp"
51 #include "interpreter/linkResolver.hpp"
52 #include "interpreter/oopMapCache.hpp"
53 #include "jfr/jfrEvents.hpp"
54 #include "jvmtifiles/jvmtiEnv.hpp"
55 #include "logging/log.hpp"
56 #include "logging/logAsyncWriter.hpp"
57 #include "logging/logConfiguration.hpp"
58 #include "logging/logStream.hpp"
59 #include "memory/allocation.inline.hpp"
60 #include "memory/iterator.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "oops/access.inline.hpp"
65 #include "oops/instanceKlass.hpp"
66 #include "oops/klass.inline.hpp"
67 #include "oops/objArrayOop.hpp"
68 #include "oops/oop.inline.hpp"
69 #include "oops/oopHandle.inline.hpp"
70 #include "oops/symbol.hpp"
71 #include "oops/typeArrayOop.inline.hpp"
72 #include "oops/verifyOopClosure.hpp"
73 #include "prims/jvm_misc.hpp"
74 #include "prims/jvmtiDeferredUpdates.hpp"
75 #include "prims/jvmtiExport.hpp"
76 #include "prims/jvmtiThreadState.hpp"
77 #include "runtime/arguments.hpp"
78 #include "runtime/atomic.hpp"
79 #include "runtime/biasedLocking.hpp"
80 #include "runtime/fieldDescriptor.inline.hpp"
81 #include "runtime/flags/jvmFlagLimit.hpp"
82 #include "runtime/deoptimization.hpp"
83 #include "runtime/frame.inline.hpp"
84 #include "runtime/handles.inline.hpp"
85 #include "runtime/handshake.hpp"
86 #include "runtime/init.hpp"
87 #include "runtime/interfaceSupport.inline.hpp"
88 #include "runtime/java.hpp"
89 #include "runtime/javaCalls.hpp"
90 #include "runtime/jniHandles.inline.hpp"
91 #include "runtime/jniPeriodicChecker.hpp"
92 #include "runtime/monitorDeflationThread.hpp"
93 #include "runtime/mutexLocker.hpp"
94 #include "runtime/nonJavaThread.hpp"
95 #include "runtime/objectMonitor.hpp"
96 #include "runtime/orderAccess.hpp"
97 #include "runtime/osThread.hpp"
98 #include "runtime/prefetch.inline.hpp"
99 #include "runtime/safepoint.hpp"
100 #include "runtime/safepointMechanism.inline.hpp"
101 #include "runtime/safepointVerifiers.hpp"
102 #include "runtime/serviceThread.hpp"
103 #include "runtime/sharedRuntime.hpp"
104 #include "runtime/stackFrameStream.inline.hpp"
105 #include "runtime/stackWatermarkSet.hpp"
106 #include "runtime/statSampler.hpp"
107 #include "runtime/task.hpp"
108 #include "runtime/thread.inline.hpp"
109 #include "runtime/threadCritical.hpp"
110 #include "runtime/threadSMR.inline.hpp"
111 #include "runtime/threadStatisticalInfo.hpp"
112 #include "runtime/threadWXSetters.inline.hpp"
113 #include "runtime/timer.hpp"
114 #include "runtime/timerTrace.hpp"
115 #include "runtime/trimNativeHeap.hpp"
116 #include "runtime/vframe.inline.hpp"
117 #include "runtime/vframeArray.hpp"
118 #include "runtime/vframe_hp.hpp"
119 #include "runtime/vmThread.hpp"
120 #include "runtime/vmOperations.hpp"
121 #include "runtime/vm_version.hpp"
122 #include "services/attachListener.hpp"
123 #include "services/management.hpp"
124 #include "services/memTracker.hpp"
125 #include "services/threadService.hpp"
126 #include "utilities/align.hpp"
127 #include "utilities/copy.hpp"
128 #include "utilities/defaultStream.hpp"
129 #include "utilities/dtrace.hpp"
130 #include "utilities/events.hpp"
131 #include "utilities/macros.hpp"
132 #include "utilities/preserveException.hpp"
133 #include "utilities/spinYield.hpp"
134 #include "utilities/vmError.hpp"
135 #if INCLUDE_JVMCI
136 #include "jvmci/jvmci.hpp"
137 #include "jvmci/jvmciEnv.hpp"
138 #endif
139 #ifdef COMPILER1
140 #include "c1/c1_Compiler.hpp"
141 #endif
142 #ifdef COMPILER2
143 #include "opto/c2compiler.hpp"
144 #include "opto/idealGraphPrinter.hpp"
145 #endif
146 #if INCLUDE_RTM_OPT
147 #include "runtime/rtmLocking.hpp"
148 #endif
149 #if INCLUDE_JFR
150 #include "jfr/jfr.hpp"
151 #endif
152
153 // Initialization after module runtime initialization
154 void universe_post_module_init(); // must happen after call_initPhase2
155
156 #ifdef DTRACE_ENABLED
157
158 // Only bother with this argument setup if dtrace is available
159
160 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
161 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
162
163 #define DTRACE_THREAD_PROBE(probe, javathread) \
164 { \
165 ResourceMark rm(this); \
166 int len = 0; \
167 const char* name = (javathread)->get_thread_name(); \
168 len = strlen(name); \
169 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
170 (char *) name, len, \
171 java_lang_Thread::thread_id((javathread)->threadObj()), \
172 (uintptr_t) (javathread)->osthread()->thread_id(), \
173 java_lang_Thread::is_daemon((javathread)->threadObj())); \
174 }
175
176 #else // ndef DTRACE_ENABLED
177
178 #define DTRACE_THREAD_PROBE(probe, javathread)
179
180 #endif // ndef DTRACE_ENABLED
181
182 #ifndef USE_LIBRARY_BASED_TLS_ONLY
183 // Current thread is maintained as a thread-local variable
184 THREAD_LOCAL Thread* Thread::_thr_current = NULL;
185 #endif
186
187 // ======= Thread ========
188 // Support for forcing alignment of thread objects for biased locking
189 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
190 if (UseBiasedLocking) {
191 const size_t alignment = markWord::biased_lock_alignment;
192 size_t aligned_size = size + (alignment - sizeof(intptr_t));
193 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
194 : AllocateHeap(aligned_size, flags, CURRENT_PC,
195 AllocFailStrategy::RETURN_NULL);
196 void* aligned_addr = align_up(real_malloc_addr, alignment);
197 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
198 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
199 "JavaThread alignment code overflowed allocated storage");
200 if (aligned_addr != real_malloc_addr) {
201 log_info(biasedlocking)("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
202 p2i(real_malloc_addr),
203 p2i(aligned_addr));
204 }
205 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
206 return aligned_addr;
207 } else {
208 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
209 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
210 }
211 }
212
213 void Thread::operator delete(void* p) {
214 if (UseBiasedLocking) {
215 FreeHeap(((Thread*) p)->_real_malloc_address);
216 } else {
217 FreeHeap(p);
218 }
219 }
220
221 void JavaThread::smr_delete() {
222 if (_on_thread_list) {
223 ThreadsSMRSupport::smr_delete(this);
224 } else {
225 delete this;
226 }
227 }
228
229 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
230 // JavaThread
231
232 DEBUG_ONLY(Thread* Thread::_starting_thread = NULL;)
233
234 Thread::Thread() {
235
236 DEBUG_ONLY(_run_state = PRE_CALL_RUN;)
237
238 // stack and get_thread
239 set_stack_base(NULL);
240 set_stack_size(0);
241 set_lgrp_id(-1);
242 DEBUG_ONLY(clear_suspendible_thread();)
243
244 // allocated data structures
245 set_osthread(NULL);
246 set_resource_area(new (mtThread)ResourceArea());
247 DEBUG_ONLY(_current_resource_mark = NULL;)
248 set_handle_area(new (mtThread) HandleArea(NULL));
249 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, mtClass));
250 set_active_handles(NULL);
251 set_free_handle_block(NULL);
252 set_last_handle_mark(NULL);
253 DEBUG_ONLY(_missed_ic_stub_refill_verifier = NULL);
254
255 // Initial value of zero ==> never claimed.
256 _threads_do_token = 0;
257 _threads_hazard_ptr = NULL;
258 _threads_list_ptr = NULL;
259 _nested_threads_hazard_ptr_cnt = 0;
260 _rcu_counter = 0;
261
262 // the handle mark links itself to last_handle_mark
263 new HandleMark(this);
264
265 // plain initialization
266 debug_only(_owned_locks = NULL;)
267 NOT_PRODUCT(_skip_gcalot = false;)
268 _jvmti_env_iteration_count = 0;
269 set_allocated_bytes(0);
270 _current_pending_raw_monitor = NULL;
271
272 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
273 _hashStateX = os::random();
274 _hashStateY = 842502087;
275 _hashStateZ = 0x8767; // (int)(3579807591LL & 0xffff) ;
276 _hashStateW = 273326509;
277
278 // Many of the following fields are effectively final - immutable
279 // Note that nascent threads can't use the Native Monitor-Mutex
280 // construct until the _MutexEvent is initialized ...
281 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
282 // we might instead use a stack of ParkEvents that we could provision on-demand.
283 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
284 // and ::Release()
285 _ParkEvent = ParkEvent::Allocate(this);
286
287 #ifdef CHECK_UNHANDLED_OOPS
288 if (CheckUnhandledOops) {
289 _unhandled_oops = new UnhandledOops(this);
290 }
291 #endif // CHECK_UNHANDLED_OOPS
292 #ifdef ASSERT
293 if (UseBiasedLocking) {
294 assert(is_aligned(this, markWord::biased_lock_alignment), "forced alignment of thread object failed");
295 assert(this == _real_malloc_address ||
296 this == align_up(_real_malloc_address, markWord::biased_lock_alignment),
297 "bug in forced alignment of thread objects");
298 }
299 #endif // ASSERT
300
301 // Notify the barrier set that a thread is being created. The initial
302 // thread is created before the barrier set is available. The call to
303 // BarrierSet::on_thread_create() for this thread is therefore deferred
304 // to BarrierSet::set_barrier_set().
305 BarrierSet* const barrier_set = BarrierSet::barrier_set();
306 if (barrier_set != NULL) {
307 barrier_set->on_thread_create(this);
308 } else {
309 // Only the main thread should be created before the barrier set
310 // and that happens just before Thread::current is set. No other thread
311 // can attach as the VM is not created yet, so they can't execute this code.
312 // If the main thread creates other threads before the barrier set that is an error.
313 assert(Thread::current_or_null() == NULL, "creating thread before barrier set");
314 }
315
316 MACOS_AARCH64_ONLY(DEBUG_ONLY(_wx_init = false));
317 }
318
319 void Thread::initialize_tlab() {
320 if (UseTLAB) {
321 tlab().initialize();
322 }
323 }
324
325 void Thread::initialize_thread_current() {
326 #ifndef USE_LIBRARY_BASED_TLS_ONLY
327 assert(_thr_current == NULL, "Thread::current already initialized");
328 _thr_current = this;
329 #endif
330 assert(ThreadLocalStorage::thread() == NULL, "ThreadLocalStorage::thread already initialized");
331 ThreadLocalStorage::set_thread(this);
332 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
333 }
334
335 void Thread::clear_thread_current() {
336 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
337 #ifndef USE_LIBRARY_BASED_TLS_ONLY
338 _thr_current = NULL;
339 #endif
340 ThreadLocalStorage::set_thread(NULL);
341 }
342
343 void Thread::record_stack_base_and_size() {
344 // Note: at this point, Thread object is not yet initialized. Do not rely on
345 // any members being initialized. Do not rely on Thread::current() being set.
346 // If possible, refrain from doing anything which may crash or assert since
347 // quite probably those crash dumps will be useless.
348 set_stack_base(os::current_stack_base());
349 set_stack_size(os::current_stack_size());
350
351 // Set stack limits after thread is initialized.
352 if (is_Java_thread()) {
353 as_Java_thread()->stack_overflow_state()->initialize(stack_base(), stack_end());
354 }
355 }
356
357 #if INCLUDE_NMT
358 void Thread::register_thread_stack_with_NMT() {
359 MemTracker::record_thread_stack(stack_end(), stack_size());
360 }
361
362 void Thread::unregister_thread_stack_with_NMT() {
363 MemTracker::release_thread_stack(stack_end(), stack_size());
364 }
365 #endif // INCLUDE_NMT
366
367 void Thread::call_run() {
368 DEBUG_ONLY(_run_state = CALL_RUN;)
369
370 // At this point, Thread object should be fully initialized and
371 // Thread::current() should be set.
372
373 assert(Thread::current_or_null() != NULL, "current thread is unset");
374 assert(Thread::current_or_null() == this, "current thread is wrong");
375
376 // Perform common initialization actions
377
378 MACOS_AARCH64_ONLY(this->init_wx());
379
380 register_thread_stack_with_NMT();
381
382 JFR_ONLY(Jfr::on_thread_start(this);)
383
384 log_debug(os, thread)("Thread " UINTX_FORMAT " stack dimensions: "
385 PTR_FORMAT "-" PTR_FORMAT " (" SIZE_FORMAT "k).",
386 os::current_thread_id(), p2i(stack_end()),
387 p2i(stack_base()), stack_size()/1024);
388
389 // Perform <ChildClass> initialization actions
390 DEBUG_ONLY(_run_state = PRE_RUN;)
391 this->pre_run();
392
393 // Invoke <ChildClass>::run()
394 DEBUG_ONLY(_run_state = RUN;)
395 this->run();
396 // Returned from <ChildClass>::run(). Thread finished.
397
398 // Perform common tear-down actions
399
400 assert(Thread::current_or_null() != NULL, "current thread is unset");
401 assert(Thread::current_or_null() == this, "current thread is wrong");
402
403 // Perform <ChildClass> tear-down actions
404 DEBUG_ONLY(_run_state = POST_RUN;)
405 this->post_run();
406
407 // Note: at this point the thread object may already have deleted itself,
408 // so from here on do not dereference *this*. Not all thread types currently
409 // delete themselves when they terminate. But no thread should ever be deleted
410 // asynchronously with respect to its termination - that is what _run_state can
411 // be used to check.
412
413 assert(Thread::current_or_null() == NULL, "current thread still present");
414 }
415
416 Thread::~Thread() {
417
418 // Attached threads will remain in PRE_CALL_RUN, as will threads that don't actually
419 // get started due to errors etc. Any active thread should at least reach post_run
420 // before it is deleted (usually in post_run()).
421 assert(_run_state == PRE_CALL_RUN ||
422 _run_state == POST_RUN, "Active Thread deleted before post_run(): "
423 "_run_state=%d", (int)_run_state);
424
425 // Notify the barrier set that a thread is being destroyed. Note that a barrier
426 // set might not be available if we encountered errors during bootstrapping.
427 BarrierSet* const barrier_set = BarrierSet::barrier_set();
428 if (barrier_set != NULL) {
429 barrier_set->on_thread_destroy(this);
430 }
431
432 // deallocate data structures
433 delete resource_area();
434 // since the handle marks are using the handle area, we have to deallocated the root
435 // handle mark before deallocating the thread's handle area,
436 assert(last_handle_mark() != NULL, "check we have an element");
437 delete last_handle_mark();
438 assert(last_handle_mark() == NULL, "check we have reached the end");
439
440 ParkEvent::Release(_ParkEvent);
441 // Set to NULL as a termination indicator for has_terminated().
442 Atomic::store(&_ParkEvent, (ParkEvent*)NULL);
443
444 delete handle_area();
445 delete metadata_handles();
446
447 // osthread() can be NULL, if creation of thread failed.
448 if (osthread() != NULL) os::free_thread(osthread());
449
450 // Clear Thread::current if thread is deleting itself and it has not
451 // already been done. This must be done before the memory is deallocated.
452 // Needed to ensure JNI correctly detects non-attached threads.
453 if (this == Thread::current_or_null()) {
454 Thread::clear_thread_current();
455 }
456
457 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
458 }
459
460 #ifdef ASSERT
461 // A JavaThread is considered dangling if it not handshake-safe with respect to
462 // the current thread, it is not on a ThreadsList, or not at safepoint.
463 void Thread::check_for_dangling_thread_pointer(Thread *thread) {
464 assert(!thread->is_Java_thread() ||
465 thread->as_Java_thread()->is_handshake_safe_for(Thread::current()) ||
466 !thread->as_Java_thread()->on_thread_list() ||
467 SafepointSynchronize::is_at_safepoint() ||
468 ThreadsSMRSupport::is_a_protected_JavaThread_with_lock(thread->as_Java_thread()),
469 "possibility of dangling Thread pointer");
470 }
471 #endif
472
473 // Is the target JavaThread protected by the calling Thread
474 // or by some other mechanism:
475 bool Thread::is_JavaThread_protected(const JavaThread* p) {
476 // Do the simplest check first:
477 if (SafepointSynchronize::is_at_safepoint()) {
478 // The target is protected since JavaThreads cannot exit
479 // while we're at a safepoint.
480 return true;
481 }
482
483 // If the target hasn't been started yet then it is trivially
484 // "protected". We assume the caller is the thread that will do
485 // the starting.
486 if (p->osthread() == NULL || p->osthread()->get_state() <= INITIALIZED) {
487 return true;
488 }
489
490 // Now make the simple checks based on who the caller is:
491 Thread* current_thread = Thread::current();
492 if (current_thread == p || Threads_lock->owner() == current_thread) {
493 // Target JavaThread is self or calling thread owns the Threads_lock.
494 // Second check is the same as Threads_lock->owner_is_self(),
495 // but we already have the current thread so check directly.
496 return true;
497 }
498
499 // Check the ThreadsLists associated with the calling thread (if any)
500 // to see if one of them protects the target JavaThread:
501 for (SafeThreadsListPtr* stlp = current_thread->_threads_list_ptr;
502 stlp != NULL; stlp = stlp->previous()) {
503 if (stlp->list()->includes(p)) {
504 // The target JavaThread is protected by this ThreadsList:
505 return true;
506 }
507 }
508
509 // Use this debug code with -XX:+UseNewCode to diagnose locations that
510 // are missing a ThreadsListHandle or other protection mechanism:
511 // guarantee(!UseNewCode, "current_thread=" INTPTR_FORMAT " is not protecting p="
512 // INTPTR_FORMAT, p2i(current_thread), p2i(p));
513
514 // Note: Since 'p' isn't protected by a TLH, the call to
515 // p->is_handshake_safe_for() may crash, but we have debug bits so
516 // we'll be able to figure out what protection mechanism is missing.
517 assert(p->is_handshake_safe_for(current_thread), "JavaThread=" INTPTR_FORMAT
518 " is not protected and not handshake safe.", p2i(p));
519
520 // The target JavaThread is not protected so it is not safe to query:
521 return false;
522 }
523
524 ThreadPriority Thread::get_priority(const Thread* const thread) {
525 ThreadPriority priority;
526 // Can return an error!
527 (void)os::get_priority(thread, priority);
528 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
529 return priority;
530 }
531
532 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
533 debug_only(check_for_dangling_thread_pointer(thread);)
534 // Can return an error!
535 (void)os::set_priority(thread, priority);
536 }
537
538
539 void Thread::start(Thread* thread) {
540 // Start is different from resume in that its safety is guaranteed by context or
541 // being called from a Java method synchronized on the Thread object.
542 if (thread->is_Java_thread()) {
543 // Initialize the thread state to RUNNABLE before starting this thread.
544 // Can not set it after the thread started because we do not know the
545 // exact thread state at that time. It could be in MONITOR_WAIT or
546 // in SLEEPING or some other state.
547 java_lang_Thread::set_thread_status(thread->as_Java_thread()->threadObj(),
548 JavaThreadStatus::RUNNABLE);
549 }
550 os::start_thread(thread);
551 }
552
553 // GC Support
554 bool Thread::claim_par_threads_do(uintx claim_token) {
555 uintx token = _threads_do_token;
556 if (token != claim_token) {
557 uintx res = Atomic::cmpxchg(&_threads_do_token, token, claim_token);
558 if (res == token) {
559 return true;
560 }
561 guarantee(res == claim_token, "invariant");
562 }
563 return false;
564 }
565
566 void Thread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
567 if (active_handles() != NULL) {
568 active_handles()->oops_do(f);
569 }
570 // Do oop for ThreadShadow
571 f->do_oop((oop*)&_pending_exception);
572 handle_area()->oops_do(f);
573 }
574
575 // If the caller is a NamedThread, then remember, in the current scope,
576 // the given JavaThread in its _processed_thread field.
577 class RememberProcessedThread: public StackObj {
578 NamedThread* _cur_thr;
579 public:
580 RememberProcessedThread(Thread* thread) {
581 Thread* self = Thread::current();
582 if (self->is_Named_thread()) {
583 _cur_thr = (NamedThread *)self;
584 assert(_cur_thr->processed_thread() == NULL, "nesting not supported");
585 _cur_thr->set_processed_thread(thread);
586 } else {
587 _cur_thr = NULL;
588 }
589 }
590
591 ~RememberProcessedThread() {
592 if (_cur_thr) {
593 assert(_cur_thr->processed_thread() != NULL, "nesting not supported");
594 _cur_thr->set_processed_thread(NULL);
595 }
596 }
597 };
598
599 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
600 // Record JavaThread to GC thread
601 RememberProcessedThread rpt(this);
602 oops_do_no_frames(f, cf);
603 oops_do_frames(f, cf);
604 }
605
606 void Thread::metadata_handles_do(void f(Metadata*)) {
607 // Only walk the Handles in Thread.
608 if (metadata_handles() != NULL) {
609 for (int i = 0; i< metadata_handles()->length(); i++) {
610 f(metadata_handles()->at(i));
611 }
612 }
613 }
614
615 void Thread::print_on(outputStream* st, bool print_extended_info) const {
616 // get_priority assumes osthread initialized
617 if (osthread() != NULL) {
618 int os_prio;
619 if (os::get_native_priority(this, &os_prio) == OS_OK) {
620 st->print("os_prio=%d ", os_prio);
621 }
622
623 st->print("cpu=%.2fms ",
624 os::thread_cpu_time(const_cast<Thread*>(this), true) / 1000000.0
625 );
626 st->print("elapsed=%.2fs ",
627 _statistical_info.getElapsedTime() / 1000.0
628 );
629 if (is_Java_thread() && (PrintExtendedThreadInfo || print_extended_info)) {
630 size_t allocated_bytes = (size_t) const_cast<Thread*>(this)->cooked_allocated_bytes();
631 st->print("allocated=" SIZE_FORMAT "%s ",
632 byte_size_in_proper_unit(allocated_bytes),
633 proper_unit_for_byte_size(allocated_bytes)
634 );
635 st->print("defined_classes=" INT64_FORMAT " ", _statistical_info.getDefineClassCount());
636 }
637
638 st->print("tid=" INTPTR_FORMAT " ", p2i(this));
639 osthread()->print_on(st);
640 }
641 ThreadsSMRSupport::print_info_on(this, st);
642 st->print(" ");
643 debug_only(if (WizardMode) print_owned_locks_on(st);)
644 }
645
646 void Thread::print() const { print_on(tty); }
647
648 // Thread::print_on_error() is called by fatal error handler. Don't use
649 // any lock or allocate memory.
650 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
651 assert(!(is_Compiler_thread() || is_Java_thread()), "Can't call name() here if it allocates");
652
653 if (is_VM_thread()) { st->print("VMThread"); }
654 else if (is_GC_task_thread()) { st->print("GCTaskThread"); }
655 else if (is_Watcher_thread()) { st->print("WatcherThread"); }
656 else if (is_ConcurrentGC_thread()) { st->print("ConcurrentGCThread"); }
657 else if (this == AsyncLogWriter::instance()) {
658 st->print("%s", this->name());
659 } else { st->print("Thread"); }
660
661 if (is_Named_thread()) {
662 st->print(" \"%s\"", name());
663 }
664
665 OSThread* os_thr = osthread();
666 if (os_thr != NULL) {
667 if (os_thr->get_state() != ZOMBIE) {
668 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
669 p2i(stack_end()), p2i(stack_base()));
670 st->print(" [id=%d]", osthread()->thread_id());
671 } else {
672 st->print(" terminated");
673 }
674 } else {
675 st->print(" unknown state (no osThread)");
676 }
677 ThreadsSMRSupport::print_info_on(this, st);
678 }
679
680 void Thread::print_value_on(outputStream* st) const {
681 if (is_Named_thread()) {
682 st->print(" \"%s\" ", name());
683 }
684 st->print(INTPTR_FORMAT, p2i(this)); // print address
685 }
686
687 #ifdef ASSERT
688 void Thread::print_owned_locks_on(outputStream* st) const {
689 Mutex* cur = _owned_locks;
690 if (cur == NULL) {
691 st->print(" (no locks) ");
692 } else {
693 st->print_cr(" Locks owned:");
694 while (cur) {
695 cur->print_on(st);
696 cur = cur->next();
697 }
698 }
699 }
700 #endif // ASSERT
701
702 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
703 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
704 // used for compilation in the future. If that change is made, the need for these methods
705 // should be revisited, and they should be removed if possible.
706
707 bool Thread::is_lock_owned(address adr) const {
708 return is_in_full_stack(adr);
709 }
710
711 bool Thread::set_as_starting_thread() {
712 assert(_starting_thread == NULL, "already initialized: "
713 "_starting_thread=" INTPTR_FORMAT, p2i(_starting_thread));
714 // NOTE: this must be called inside the main thread.
715 DEBUG_ONLY(_starting_thread = this;)
716 return os::create_main_thread(this->as_Java_thread());
717 }
718
719 static void initialize_class(Symbol* class_name, TRAPS) {
720 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
721 InstanceKlass::cast(klass)->initialize(CHECK);
722 }
723
724
725 // Creates the initial ThreadGroup
726 static Handle create_initial_thread_group(TRAPS) {
727 Handle system_instance = JavaCalls::construct_new_instance(
728 vmClasses::ThreadGroup_klass(),
729 vmSymbols::void_method_signature(),
730 CHECK_NH);
731 Universe::set_system_thread_group(system_instance());
732
733 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
734 Handle main_instance = JavaCalls::construct_new_instance(
735 vmClasses::ThreadGroup_klass(),
736 vmSymbols::threadgroup_string_void_signature(),
737 system_instance,
738 string,
739 CHECK_NH);
740 return main_instance;
741 }
742
743 // Creates the initial Thread, and sets it to running.
744 static void create_initial_thread(Handle thread_group, JavaThread* thread,
745 TRAPS) {
746 InstanceKlass* ik = vmClasses::Thread_klass();
747 assert(ik->is_initialized(), "must be");
748 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
749
750 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
751 // constructor calls Thread.current(), which must be set here for the
752 // initial thread.
753 java_lang_Thread::set_thread(thread_oop(), thread);
754 java_lang_Thread::set_priority(thread_oop(), NormPriority);
755 thread->set_threadObj(thread_oop());
756
757 Handle string = java_lang_String::create_from_str("main", CHECK);
758
759 JavaValue result(T_VOID);
760 JavaCalls::call_special(&result, thread_oop,
761 ik,
762 vmSymbols::object_initializer_name(),
763 vmSymbols::threadgroup_string_void_signature(),
764 thread_group,
765 string,
766 CHECK);
767
768 // Set thread status to running since main thread has
769 // been started and running.
770 java_lang_Thread::set_thread_status(thread_oop(),
771 JavaThreadStatus::RUNNABLE);
772 }
773
774 // Extract version and vendor specific information from
775 // java.lang.VersionProps fields.
776 // Returned char* is allocated in the thread's resource area
777 // so must be copied for permanency.
778 static const char* get_java_version_info(InstanceKlass* ik,
779 Symbol* field_name) {
780 fieldDescriptor fd;
781 bool found = ik != NULL &&
782 ik->find_local_field(field_name,
783 vmSymbols::string_signature(), &fd);
784 if (found) {
785 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
786 if (name_oop == NULL) {
787 return NULL;
788 }
789 const char* name = java_lang_String::as_utf8_string(name_oop);
790 return name;
791 } else {
792 return NULL;
793 }
794 }
795
796 // General purpose hook into Java code, run once when the VM is initialized.
797 // The Java library method itself may be changed independently from the VM.
798 static void call_postVMInitHook(TRAPS) {
799 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
800 if (klass != NULL) {
801 JavaValue result(T_VOID);
802 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
803 vmSymbols::void_method_signature(),
804 CHECK);
805 }
806 }
807
808 // Initialized by VMThread at vm_global_init
809 static OopStorage* _thread_oop_storage = NULL;
810
811 oop JavaThread::threadObj() const {
812 return _threadObj.resolve();
813 }
814
815 void JavaThread::set_threadObj(oop p) {
816 assert(_thread_oop_storage != NULL, "not yet initialized");
817 _threadObj = OopHandle(_thread_oop_storage, p);
818 }
819
820 OopStorage* JavaThread::thread_oop_storage() {
821 assert(_thread_oop_storage != NULL, "not yet initialized");
822 return _thread_oop_storage;
823 }
824
825 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
826 bool daemon, TRAPS) {
827 assert(thread_group.not_null(), "thread group should be specified");
828 assert(threadObj() == NULL, "should only create Java thread object once");
829
830 InstanceKlass* ik = vmClasses::Thread_klass();
831 assert(ik->is_initialized(), "must be");
832 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
833
834 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
835 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
836 // constructor calls Thread.current(), which must be set here.
837 java_lang_Thread::set_thread(thread_oop(), this);
838 java_lang_Thread::set_priority(thread_oop(), NormPriority);
839 set_threadObj(thread_oop());
840
841 JavaValue result(T_VOID);
842 if (thread_name != NULL) {
843 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
844 // Thread gets assigned specified name and null target
845 JavaCalls::call_special(&result,
846 thread_oop,
847 ik,
848 vmSymbols::object_initializer_name(),
849 vmSymbols::threadgroup_string_void_signature(),
850 thread_group,
851 name,
852 THREAD);
853 } else {
854 // Thread gets assigned name "Thread-nnn" and null target
855 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
856 JavaCalls::call_special(&result,
857 thread_oop,
858 ik,
859 vmSymbols::object_initializer_name(),
860 vmSymbols::threadgroup_runnable_void_signature(),
861 thread_group,
862 Handle(),
863 THREAD);
864 }
865
866
867 if (daemon) {
868 java_lang_Thread::set_daemon(thread_oop());
869 }
870
871 if (HAS_PENDING_EXCEPTION) {
872 return;
873 }
874
875 Klass* group = vmClasses::ThreadGroup_klass();
876 Handle threadObj(THREAD, this->threadObj());
877
878 JavaCalls::call_special(&result,
879 thread_group,
880 group,
881 vmSymbols::add_method_name(),
882 vmSymbols::thread_void_signature(),
883 threadObj, // Arg 1
884 THREAD);
885 }
886
887 // ======= JavaThread ========
888
889 #if INCLUDE_JVMCI
890
891 jlong* JavaThread::_jvmci_old_thread_counters;
892
893 bool jvmci_counters_include(JavaThread* thread) {
894 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
895 }
896
897 void JavaThread::collect_counters(jlong* array, int length) {
898 assert(length == JVMCICounterSize, "wrong value");
899 for (int i = 0; i < length; i++) {
900 array[i] = _jvmci_old_thread_counters[i];
901 }
902 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *tp = jtiwh.next(); ) {
903 if (jvmci_counters_include(tp)) {
904 for (int i = 0; i < length; i++) {
905 array[i] += tp->_jvmci_counters[i];
906 }
907 }
908 }
909 }
910
911 // Attempt to enlarge the array for per thread counters.
912 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
913 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
914 if (new_counters == NULL) {
915 return NULL;
916 }
917 if (old_counters == NULL) {
918 old_counters = new_counters;
919 memset(old_counters, 0, sizeof(jlong) * new_size);
920 } else {
921 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
922 new_counters[i] = old_counters[i];
923 }
924 if (new_size > current_size) {
925 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
926 }
927 FREE_C_HEAP_ARRAY(jlong, old_counters);
928 }
929 return new_counters;
930 }
931
932 // Attempt to enlarge the array for per thread counters.
933 bool JavaThread::resize_counters(int current_size, int new_size) {
934 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
935 if (new_counters == NULL) {
936 return false;
937 } else {
938 _jvmci_counters = new_counters;
939 return true;
940 }
941 }
942
943 class VM_JVMCIResizeCounters : public VM_Operation {
944 private:
945 int _new_size;
946 bool _failed;
947
948 public:
949 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
950 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
951 bool allow_nested_vm_operations() const { return true; }
952 void doit() {
953 // Resize the old thread counters array
954 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
955 if (new_counters == NULL) {
956 _failed = true;
957 return;
958 } else {
959 JavaThread::_jvmci_old_thread_counters = new_counters;
960 }
961
962 // Now resize each threads array
963 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *tp = jtiwh.next(); ) {
964 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
965 _failed = true;
966 break;
967 }
968 }
969 if (!_failed) {
970 JVMCICounterSize = _new_size;
971 }
972 }
973
974 bool failed() { return _failed; }
975 };
976
977 bool JavaThread::resize_all_jvmci_counters(int new_size) {
978 VM_JVMCIResizeCounters op(new_size);
979 VMThread::execute(&op);
980 return !op.failed();
981 }
982
983 #endif // INCLUDE_JVMCI
984
985 #ifdef ASSERT
986 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
987 void JavaThread::check_possible_safepoint() {
988 if (_no_safepoint_count > 0) {
989 print_owned_locks();
990 assert(false, "Possible safepoint reached by thread that does not allow it");
991 }
992 #ifdef CHECK_UNHANDLED_OOPS
993 // Clear unhandled oops in JavaThreads so we get a crash right away.
994 clear_unhandled_oops();
995 #endif // CHECK_UNHANDLED_OOPS
996 }
997
998 void JavaThread::check_for_valid_safepoint_state() {
999 // Check NoSafepointVerifier, which is implied by locks taken that can be
1000 // shared with the VM thread. This makes sure that no locks with allow_vm_block
1001 // are held.
1002 check_possible_safepoint();
1003
1004 if (thread_state() != _thread_in_vm) {
1005 fatal("LEAF method calling lock?");
1006 }
1007
1008 if (GCALotAtAllSafepoints) {
1009 // We could enter a safepoint here and thus have a gc
1010 InterfaceSupport::check_gc_alot();
1011 }
1012 }
1013 #endif // ASSERT
1014
1015 // A JavaThread is a normal Java thread
1016
1017 JavaThread::JavaThread() :
1018 // Initialize fields
1019
1020 _in_asgct(false),
1021 _on_thread_list(false),
1022 DEBUG_ONLY(_java_call_counter(0) COMMA)
1023 _entry_point(nullptr),
1024 _deopt_mark(nullptr),
1025 _deopt_nmethod(nullptr),
1026 _vframe_array_head(nullptr),
1027 _vframe_array_last(nullptr),
1028 _jvmti_deferred_updates(nullptr),
1029 _callee_target(nullptr),
1030 _vm_result(nullptr),
1031 _vm_result_2(nullptr),
1032
1033 _current_pending_monitor(NULL),
1034 _current_pending_monitor_is_from_java(true),
1035 _current_waiting_monitor(NULL),
1036 _Stalled(0),
1037
1038 _monitor_chunks(nullptr),
1039
1040 _suspend_flags(0),
1041 _async_exception_condition(_no_async_condition),
1042 _pending_async_exception(nullptr),
1043
1044 _thread_state(_thread_new),
1045 _saved_exception_pc(nullptr),
1046 #ifdef ASSERT
1047 _no_safepoint_count(0),
1048 _visited_for_critical_count(false),
1049 #endif
1050
1051 _terminated(_not_terminated),
1052 _in_deopt_handler(0),
1053 _doing_unsafe_access(false),
1054 _do_not_unlock_if_synchronized(false),
1055 _jni_attach_state(_not_attaching_via_jni),
1056 #if INCLUDE_JVMCI
1057 _pending_deoptimization(-1),
1058 _pending_monitorenter(false),
1059 _pending_transfer_to_interpreter(false),
1060 _in_retryable_allocation(false),
1061 _pending_failed_speculation(0),
1062 _jvmci{nullptr},
1063 _jvmci_counters(nullptr),
1064 _jvmci_reserved0(0),
1065 _jvmci_reserved1(0),
1066 _jvmci_reserved_oop0(nullptr),
1067 #endif // INCLUDE_JVMCI
1068
1069 _exception_oop(oop()),
1070 _exception_pc(0),
1071 _exception_handler_pc(0),
1072 _is_method_handle_return(0),
1073
1074 _jni_active_critical(0),
1075 _pending_jni_exception_check_fn(nullptr),
1076 _depth_first_number(0),
1077
1078 // JVMTI PopFrame support
1079 _popframe_condition(popframe_inactive),
1080 _frames_to_pop_failed_realloc(0),
1081
1082 _handshake(this),
1083
1084 _popframe_preserved_args(nullptr),
1085 _popframe_preserved_args_size(0),
1086
1087 _jvmti_thread_state(nullptr),
1088 _interp_only_mode(0),
1089 _should_post_on_exceptions_flag(JNI_FALSE),
1090 _thread_stat(new ThreadStatistics()),
1091
1092 _parker(),
1093 _cached_monitor_info(nullptr),
1094
1095 _class_to_be_initialized(nullptr),
1096
1097 _SleepEvent(ParkEvent::Allocate(this))
1098 {
1099 set_jni_functions(jni_functions());
1100
1101 #if INCLUDE_JVMCI
1102 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
1103 if (JVMCICounterSize > 0) {
1104 resize_counters(0, (int) JVMCICounterSize);
1105 }
1106 #endif // INCLUDE_JVMCI
1107
1108 // Setup safepoint state info for this thread
1109 ThreadSafepointState::create(this);
1110
1111 SafepointMechanism::initialize_header(this);
1112
1113 set_requires_cross_modify_fence(false);
1114
1115 pd_initialize();
1116 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
1117 }
1118
1119 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
1120 if (is_attaching_via_jni) {
1121 _jni_attach_state = _attaching_via_jni;
1122 }
1123 }
1124
1125
1126 // interrupt support
1127
1128 void JavaThread::interrupt() {
1129 // All callers should have 'this' thread protected by a
1130 // ThreadsListHandle so that it cannot terminate and deallocate
1131 // itself.
1132 debug_only(check_for_dangling_thread_pointer(this);)
1133
1134 // For Windows _interrupt_event
1135 osthread()->set_interrupted(true);
1136
1137 // For Thread.sleep
1138 _SleepEvent->unpark();
1139
1140 // For JSR166 LockSupport.park
1141 parker()->unpark();
1142
1143 // For ObjectMonitor and JvmtiRawMonitor
1144 _ParkEvent->unpark();
1145 }
1146
1147
1148 bool JavaThread::is_interrupted(bool clear_interrupted) {
1149 debug_only(check_for_dangling_thread_pointer(this);)
1150
1151 if (_threadObj.peek() == NULL) {
1152 // If there is no j.l.Thread then it is impossible to have
1153 // been interrupted. We can find NULL during VM initialization
1154 // or when a JNI thread is still in the process of attaching.
1155 // In such cases this must be the current thread.
1156 assert(this == Thread::current(), "invariant");
1157 return false;
1158 }
1159
1160 bool interrupted = java_lang_Thread::interrupted(threadObj());
1161
1162 // NOTE that since there is no "lock" around the interrupt and
1163 // is_interrupted operations, there is the possibility that the
1164 // interrupted flag will be "false" but that the
1165 // low-level events will be in the signaled state. This is
1166 // intentional. The effect of this is that Object.wait() and
1167 // LockSupport.park() will appear to have a spurious wakeup, which
1168 // is allowed and not harmful, and the possibility is so rare that
1169 // it is not worth the added complexity to add yet another lock.
1170 // For the sleep event an explicit reset is performed on entry
1171 // to JavaThread::sleep, so there is no early return. It has also been
1172 // recommended not to put the interrupted flag into the "event"
1173 // structure because it hides the issue.
1174 // Also, because there is no lock, we must only clear the interrupt
1175 // state if we are going to report that we were interrupted; otherwise
1176 // an interrupt that happens just after we read the field would be lost.
1177 if (interrupted && clear_interrupted) {
1178 assert(this == Thread::current(), "only the current thread can clear");
1179 java_lang_Thread::set_interrupted(threadObj(), false);
1180 osthread()->set_interrupted(false);
1181 }
1182
1183 return interrupted;
1184 }
1185
1186 void JavaThread::block_if_vm_exited() {
1187 if (_terminated == _vm_exited) {
1188 // _vm_exited is set at safepoint, and Threads_lock is never released
1189 // we will block here forever.
1190 // Here we can be doing a jump from a safe state to an unsafe state without
1191 // proper transition, but it happens after the final safepoint has begun.
1192 set_thread_state(_thread_in_vm);
1193 Threads_lock->lock();
1194 ShouldNotReachHere();
1195 }
1196 }
1197
1198 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
1199 _jni_attach_state = _not_attaching_via_jni;
1200 set_entry_point(entry_point);
1201 // Create the native thread itself.
1202 // %note runtime_23
1203 os::ThreadType thr_type = os::java_thread;
1204 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
1205 os::java_thread;
1206 os::create_thread(this, thr_type, stack_sz);
1207 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1208 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1209 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1210 // the exception consists of creating the exception object & initializing it, initialization
1211 // will leave the VM via a JavaCall and then all locks must be unlocked).
1212 //
1213 // The thread is still suspended when we reach here. Thread must be explicit started
1214 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1215 // by calling Threads:add. The reason why this is not done here, is because the thread
1216 // object must be fully initialized (take a look at JVM_Start)
1217 }
1218
1219 JavaThread::~JavaThread() {
1220
1221 // Ask ServiceThread to release the threadObj OopHandle
1222 ServiceThread::add_oop_handle_release(_threadObj);
1223
1224 // Return the sleep event to the free list
1225 ParkEvent::Release(_SleepEvent);
1226 _SleepEvent = NULL;
1227
1228 // Free any remaining previous UnrollBlock
1229 vframeArray* old_array = vframe_array_last();
1230
1231 if (old_array != NULL) {
1232 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1233 old_array->set_unroll_block(NULL);
1234 delete old_info;
1235 delete old_array;
1236 }
1237
1238 JvmtiDeferredUpdates* updates = deferred_updates();
1239 if (updates != NULL) {
1240 // This can only happen if thread is destroyed before deoptimization occurs.
1241 assert(updates->count() > 0, "Updates holder not deleted");
1242 // free deferred updates.
1243 delete updates;
1244 set_deferred_updates(NULL);
1245 }
1246
1247 // All Java related clean up happens in exit
1248 ThreadSafepointState::destroy(this);
1249 if (_thread_stat != NULL) delete _thread_stat;
1250
1251 #if INCLUDE_JVMCI
1252 if (JVMCICounterSize > 0) {
1253 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
1254 }
1255 #endif // INCLUDE_JVMCI
1256 }
1257
1258
1259 // First JavaThread specific code executed by a new Java thread.
1260 void JavaThread::pre_run() {
1261 // empty - see comments in run()
1262 }
1263
1264 // The main routine called by a new Java thread. This isn't overridden
1265 // by subclasses, instead different subclasses define a different "entry_point"
1266 // which defines the actual logic for that kind of thread.
1267 void JavaThread::run() {
1268 // initialize thread-local alloc buffer related fields
1269 initialize_tlab();
1270
1271 _stack_overflow_state.create_stack_guard_pages();
1272
1273 cache_global_variables();
1274
1275 // Thread is now sufficiently initialized to be handled by the safepoint code as being
1276 // in the VM. Change thread state from _thread_new to _thread_in_vm
1277 ThreadStateTransition::transition(this, _thread_new, _thread_in_vm);
1278 // Before a thread is on the threads list it is always safe, so after leaving the
1279 // _thread_new we should emit a instruction barrier. The distance to modified code
1280 // from here is probably far enough, but this is consistent and safe.
1281 OrderAccess::cross_modify_fence();
1282
1283 assert(JavaThread::current() == this, "sanity check");
1284 assert(!Thread::current()->owns_locks(), "sanity check");
1285
1286 DTRACE_THREAD_PROBE(start, this);
1287
1288 // This operation might block. We call that after all safepoint checks for a new thread has
1289 // been completed.
1290 set_active_handles(JNIHandleBlock::allocate_block());
1291
1292 if (JvmtiExport::should_post_thread_life()) {
1293 JvmtiExport::post_thread_start(this);
1294
1295 }
1296
1297 // We call another function to do the rest so we are sure that the stack addresses used
1298 // from there will be lower than the stack base just computed.
1299 thread_main_inner();
1300 }
1301
1302 void JavaThread::thread_main_inner() {
1303 assert(JavaThread::current() == this, "sanity check");
1304 assert(_threadObj.peek() != NULL, "just checking");
1305
1306 // Execute thread entry point unless this thread has a pending exception
1307 // or has been stopped before starting.
1308 // Note: Due to JVM_StopThread we can have pending exceptions already!
1309 if (!this->has_pending_exception() &&
1310 !java_lang_Thread::is_stillborn(this->threadObj())) {
1311 {
1312 ResourceMark rm(this);
1313 this->set_native_thread_name(this->get_thread_name());
1314 }
1315 HandleMark hm(this);
1316 this->entry_point()(this, this);
1317 }
1318
1319 DTRACE_THREAD_PROBE(stop, this);
1320
1321 // Cleanup is handled in post_run()
1322 }
1323
1324 // Shared teardown for all JavaThreads
1325 void JavaThread::post_run() {
1326 this->exit(false);
1327 this->unregister_thread_stack_with_NMT();
1328 // Defer deletion to here to ensure 'this' is still referenceable in call_run
1329 // for any shared tear-down.
1330 this->smr_delete();
1331 }
1332
1333 static void ensure_join(JavaThread* thread) {
1334 // We do not need to grab the Threads_lock, since we are operating on ourself.
1335 Handle threadObj(thread, thread->threadObj());
1336 assert(threadObj.not_null(), "java thread object must exist");
1337 ObjectLocker lock(threadObj, thread);
1338 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1339 thread->clear_pending_exception();
1340 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1341 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
1342 // Clear the native thread instance - this makes isAlive return false and allows the join()
1343 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model
1344 // requirements.
1345 java_lang_Thread::release_set_thread(threadObj(), NULL);
1346 lock.notify_all(thread);
1347 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1348 thread->clear_pending_exception();
1349 }
1350
1351 static bool is_daemon(oop threadObj) {
1352 return (threadObj != NULL && java_lang_Thread::is_daemon(threadObj));
1353 }
1354
1355 // For any new cleanup additions, please check to see if they need to be applied to
1356 // cleanup_failed_attach_current_thread as well.
1357 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1358 assert(this == JavaThread::current(), "thread consistency check");
1359
1360 elapsedTimer _timer_exit_phase1;
1361 elapsedTimer _timer_exit_phase2;
1362 elapsedTimer _timer_exit_phase3;
1363 elapsedTimer _timer_exit_phase4;
1364
1365 if (log_is_enabled(Debug, os, thread, timer)) {
1366 _timer_exit_phase1.start();
1367 }
1368
1369 HandleMark hm(this);
1370 Handle uncaught_exception(this, this->pending_exception());
1371 this->clear_pending_exception();
1372 Handle threadObj(this, this->threadObj());
1373 assert(threadObj.not_null(), "Java thread object should be created");
1374
1375 if (!destroy_vm) {
1376 if (uncaught_exception.not_null()) {
1377 EXCEPTION_MARK;
1378 // Call method Thread.dispatchUncaughtException().
1379 Klass* thread_klass = vmClasses::Thread_klass();
1380 JavaValue result(T_VOID);
1381 JavaCalls::call_virtual(&result,
1382 threadObj, thread_klass,
1383 vmSymbols::dispatchUncaughtException_name(),
1384 vmSymbols::throwable_void_signature(),
1385 uncaught_exception,
1386 THREAD);
1387 if (HAS_PENDING_EXCEPTION) {
1388 ResourceMark rm(this);
1389 jio_fprintf(defaultStream::error_stream(),
1390 "\nException: %s thrown from the UncaughtExceptionHandler"
1391 " in thread \"%s\"\n",
1392 pending_exception()->klass()->external_name(),
1393 get_thread_name());
1394 CLEAR_PENDING_EXCEPTION;
1395 }
1396 }
1397
1398 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1399 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1400 // is deprecated anyhow.
1401 if (!is_Compiler_thread()) {
1402 int count = 3;
1403 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1404 EXCEPTION_MARK;
1405 JavaValue result(T_VOID);
1406 Klass* thread_klass = vmClasses::Thread_klass();
1407 JavaCalls::call_virtual(&result,
1408 threadObj, thread_klass,
1409 vmSymbols::exit_method_name(),
1410 vmSymbols::void_method_signature(),
1411 THREAD);
1412 CLEAR_PENDING_EXCEPTION;
1413 }
1414 }
1415 // notify JVMTI
1416 if (JvmtiExport::should_post_thread_life()) {
1417 JvmtiExport::post_thread_end(this);
1418 }
1419
1420 // The careful dance between thread suspension and exit is handled here.
1421 // Since we are in thread_in_vm state and suspension is done with handshakes,
1422 // we can just put in the exiting state and it will be correctly handled.
1423 set_terminated(_thread_exiting);
1424
1425 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
1426 } else {
1427 assert(!is_terminated() && !is_exiting(), "must not be exiting");
1428 // before_exit() has already posted JVMTI THREAD_END events
1429 }
1430
1431 if (log_is_enabled(Debug, os, thread, timer)) {
1432 _timer_exit_phase1.stop();
1433 _timer_exit_phase2.start();
1434 }
1435
1436 // Capture daemon status before the thread is marked as terminated.
1437 bool daemon = is_daemon(threadObj());
1438
1439 // Notify waiters on thread object. This has to be done after exit() is called
1440 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1441 // group should have the destroyed bit set before waiters are notified).
1442 ensure_join(this);
1443 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1444
1445 if (log_is_enabled(Debug, os, thread, timer)) {
1446 _timer_exit_phase2.stop();
1447 _timer_exit_phase3.start();
1448 }
1449 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1450 // held by this thread must be released. The spec does not distinguish
1451 // between JNI-acquired and regular Java monitors. We can only see
1452 // regular Java monitors here if monitor enter-exit matching is broken.
1453 //
1454 // ensure_join() ignores IllegalThreadStateExceptions, and so does
1455 // ObjectSynchronizer::release_monitors_owned_by_thread().
1456 if (exit_type == jni_detach) {
1457 // Sanity check even though JNI DetachCurrentThread() would have
1458 // returned JNI_ERR if there was a Java frame. JavaThread exit
1459 // should be done executing Java code by the time we get here.
1460 assert(!this->has_last_Java_frame(),
1461 "should not have a Java frame when detaching or exiting");
1462 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1463 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1464 }
1465
1466 // These things needs to be done while we are still a Java Thread. Make sure that thread
1467 // is in a consistent state, in case GC happens
1468 JFR_ONLY(Jfr::on_thread_exit(this);)
1469
1470 if (active_handles() != NULL) {
1471 JNIHandleBlock* block = active_handles();
1472 set_active_handles(NULL);
1473 JNIHandleBlock::release_block(block);
1474 }
1475
1476 if (free_handle_block() != NULL) {
1477 JNIHandleBlock* block = free_handle_block();
1478 set_free_handle_block(NULL);
1479 JNIHandleBlock::release_block(block);
1480 }
1481
1482 // These have to be removed while this is still a valid thread.
1483 _stack_overflow_state.remove_stack_guard_pages();
1484
1485 if (UseTLAB) {
1486 tlab().retire();
1487 }
1488
1489 if (JvmtiEnv::environments_might_exist()) {
1490 JvmtiExport::cleanup_thread(this);
1491 }
1492
1493 // We need to cache the thread name for logging purposes below as once
1494 // we have called on_thread_detach this thread must not access any oops.
1495 char* thread_name = NULL;
1496 if (log_is_enabled(Debug, os, thread, timer)) {
1497 ResourceMark rm(this);
1498 thread_name = os::strdup(get_thread_name());
1499 }
1500
1501 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
1502 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
1503 os::current_thread_id());
1504
1505 if (log_is_enabled(Debug, os, thread, timer)) {
1506 _timer_exit_phase3.stop();
1507 _timer_exit_phase4.start();
1508 }
1509
1510 #if INCLUDE_JVMCI
1511 if (JVMCICounterSize > 0) {
1512 if (jvmci_counters_include(this)) {
1513 for (int i = 0; i < JVMCICounterSize; i++) {
1514 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
1515 }
1516 }
1517 }
1518 #endif // INCLUDE_JVMCI
1519
1520 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1521 Threads::remove(this, daemon);
1522
1523 if (log_is_enabled(Debug, os, thread, timer)) {
1524 _timer_exit_phase4.stop();
1525 log_debug(os, thread, timer)("name='%s'"
1526 ", exit-phase1=" JLONG_FORMAT
1527 ", exit-phase2=" JLONG_FORMAT
1528 ", exit-phase3=" JLONG_FORMAT
1529 ", exit-phase4=" JLONG_FORMAT,
1530 thread_name,
1531 _timer_exit_phase1.milliseconds(),
1532 _timer_exit_phase2.milliseconds(),
1533 _timer_exit_phase3.milliseconds(),
1534 _timer_exit_phase4.milliseconds());
1535 os::free(thread_name);
1536 }
1537 }
1538
1539 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
1540 if (active_handles() != NULL) {
1541 JNIHandleBlock* block = active_handles();
1542 set_active_handles(NULL);
1543 JNIHandleBlock::release_block(block);
1544 }
1545
1546 if (free_handle_block() != NULL) {
1547 JNIHandleBlock* block = free_handle_block();
1548 set_free_handle_block(NULL);
1549 JNIHandleBlock::release_block(block);
1550 }
1551
1552 // These have to be removed while this is still a valid thread.
1553 _stack_overflow_state.remove_stack_guard_pages();
1554
1555 if (UseTLAB) {
1556 tlab().retire();
1557 }
1558
1559 Threads::remove(this, is_daemon);
1560 this->smr_delete();
1561 }
1562
1563 JavaThread* JavaThread::active() {
1564 Thread* thread = Thread::current();
1565 if (thread->is_Java_thread()) {
1566 return thread->as_Java_thread();
1567 } else {
1568 assert(thread->is_VM_thread(), "this must be a vm thread");
1569 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1570 JavaThread *ret = op == NULL ? NULL : op->calling_thread()->as_Java_thread();
1571 return ret;
1572 }
1573 }
1574
1575 bool JavaThread::is_lock_owned(address adr) const {
1576 if (Thread::is_lock_owned(adr)) return true;
1577
1578 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1579 if (chunk->contains(adr)) return true;
1580 }
1581
1582 return false;
1583 }
1584
1585 oop JavaThread::exception_oop() const {
1586 return Atomic::load(&_exception_oop);
1587 }
1588
1589 void JavaThread::set_exception_oop(oop o) {
1590 Atomic::store(&_exception_oop, o);
1591 }
1592
1593 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1594 chunk->set_next(monitor_chunks());
1595 set_monitor_chunks(chunk);
1596 }
1597
1598 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1599 guarantee(monitor_chunks() != NULL, "must be non empty");
1600 if (monitor_chunks() == chunk) {
1601 set_monitor_chunks(chunk->next());
1602 } else {
1603 MonitorChunk* prev = monitor_chunks();
1604 while (prev->next() != chunk) prev = prev->next();
1605 prev->set_next(chunk->next());
1606 }
1607 }
1608
1609
1610 // Asynchronous exceptions support
1611 //
1612 // Note: this function shouldn't block if it's called in
1613 // _thread_in_native_trans state (such as from
1614 // check_special_condition_for_native_trans()).
1615 void JavaThread::check_and_handle_async_exceptions() {
1616 if (has_last_Java_frame() && has_async_exception_condition()) {
1617 // If we are at a polling page safepoint (not a poll return)
1618 // then we must defer async exception because live registers
1619 // will be clobbered by the exception path. Poll return is
1620 // ok because the call we a returning from already collides
1621 // with exception handling registers and so there is no issue.
1622 // (The exception handling path kills call result registers but
1623 // this is ok since the exception kills the result anyway).
1624
1625 if (is_at_poll_safepoint()) {
1626 // if the code we are returning to has deoptimized we must defer
1627 // the exception otherwise live registers get clobbered on the
1628 // exception path before deoptimization is able to retrieve them.
1629 //
1630 RegisterMap map(this, false);
1631 frame caller_fr = last_frame().sender(&map);
1632 assert(caller_fr.is_compiled_frame(), "what?");
1633 if (caller_fr.is_deoptimized_frame()) {
1634 log_info(exceptions)("deferred async exception at compiled safepoint");
1635 return;
1636 }
1637 }
1638 }
1639
1640 AsyncExceptionCondition condition = clear_async_exception_condition();
1641 if (condition == _no_async_condition) {
1642 // Conditions have changed since has_special_runtime_exit_condition()
1643 // was called:
1644 // - if we were here only because of an external suspend request,
1645 // then that was taken care of above (or cancelled) so we are done
1646 // - if we were here because of another async request, then it has
1647 // been cleared between the has_special_runtime_exit_condition()
1648 // and now so again we are done
1649 return;
1650 }
1651
1652 // Check for pending async. exception
1653 if (_pending_async_exception != NULL) {
1654 // Only overwrite an already pending exception, if it is not a threadDeath.
1655 if (!has_pending_exception() || !pending_exception()->is_a(vmClasses::ThreadDeath_klass())) {
1656
1657 // We cannot call Exceptions::_throw(...) here because we cannot block
1658 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1659
1660 LogTarget(Info, exceptions) lt;
1661 if (lt.is_enabled()) {
1662 ResourceMark rm;
1663 LogStream ls(lt);
1664 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1665 if (has_last_Java_frame()) {
1666 frame f = last_frame();
1667 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1668 }
1669 ls.print_cr(" of type: %s", _pending_async_exception->klass()->external_name());
1670 }
1671 _pending_async_exception = NULL;
1672 // Clear condition from _suspend_flags since we have finished processing it.
1673 clear_suspend_flag(_has_async_exception);
1674 }
1675 }
1676
1677 if (condition == _async_unsafe_access_error && !has_pending_exception()) {
1678 // We may be at method entry which requires we save the do-not-unlock flag.
1679 UnlockFlagSaver fs(this);
1680 switch (thread_state()) {
1681 case _thread_in_vm: {
1682 JavaThread* THREAD = this;
1683 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in an unsafe memory access operation");
1684 return;
1685 }
1686 case _thread_in_native: {
1687 ThreadInVMfromNative tiv(this);
1688 JavaThread* THREAD = this;
1689 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in an unsafe memory access operation");
1690 return;
1691 }
1692 case _thread_in_Java: {
1693 ThreadInVMfromJava tiv(this);
1694 JavaThread* THREAD = this;
1695 Exceptions::throw_unsafe_access_internal_error(THREAD, __FILE__, __LINE__, "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1696 return;
1697 }
1698 default:
1699 ShouldNotReachHere();
1700 }
1701 }
1702
1703 assert(has_pending_exception(), "must have handled the async condition if no exception");
1704 }
1705
1706 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1707
1708 if (is_obj_deopt_suspend()) {
1709 frame_anchor()->make_walkable();
1710 wait_for_object_deoptimization();
1711 }
1712
1713 // We might be here for reasons in addition to the self-suspend request
1714 // so check for other async requests.
1715 if (check_asyncs) {
1716 check_and_handle_async_exceptions();
1717 }
1718
1719 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1720 }
1721
1722 class InstallAsyncExceptionClosure : public HandshakeClosure {
1723 Handle _throwable; // The Throwable thrown at the target Thread
1724 public:
1725 InstallAsyncExceptionClosure(Handle throwable) : HandshakeClosure("InstallAsyncException"), _throwable(throwable) {}
1726
1727 void do_thread(Thread* thr) {
1728 JavaThread* target = thr->as_Java_thread();
1729 // Note that this now allows multiple ThreadDeath exceptions to be
1730 // thrown at a thread.
1731 // The target thread has run and has not exited yet.
1732 target->send_thread_stop(_throwable());
1733 }
1734 };
1735
1736 void JavaThread::send_async_exception(oop java_thread, oop java_throwable) {
1737 Handle throwable(Thread::current(), java_throwable);
1738 JavaThread* target = java_lang_Thread::thread(java_thread);
1739 InstallAsyncExceptionClosure vm_stop(throwable);
1740 Handshake::execute(&vm_stop, target);
1741 }
1742
1743 void JavaThread::send_thread_stop(oop java_throwable) {
1744 ResourceMark rm;
1745 assert(is_handshake_safe_for(Thread::current()),
1746 "should be self or handshakee");
1747
1748 // Do not throw asynchronous exceptions against the compiler thread
1749 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1750 if (!can_call_java()) return;
1751
1752 {
1753 // Actually throw the Throwable against the target Thread - however
1754 // only if there is no thread death exception installed already.
1755 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(vmClasses::ThreadDeath_klass())) {
1756 // If the topmost frame is a runtime stub, then we are calling into
1757 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1758 // must deoptimize the caller before continuing, as the compiled exception handler table
1759 // may not be valid
1760 if (has_last_Java_frame()) {
1761 frame f = last_frame();
1762 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1763 RegisterMap reg_map(this, false);
1764 frame compiled_frame = f.sender(®_map);
1765 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1766 Deoptimization::deoptimize(this, compiled_frame);
1767 }
1768 }
1769 }
1770
1771 // Set async. pending exception in thread.
1772 set_pending_async_exception(java_throwable);
1773
1774 if (log_is_enabled(Info, exceptions)) {
1775 ResourceMark rm;
1776 log_info(exceptions)("Pending Async. exception installed of type: %s",
1777 InstanceKlass::cast(_pending_async_exception->klass())->external_name());
1778 }
1779 // for AbortVMOnException flag
1780 Exceptions::debug_check_abort(_pending_async_exception->klass()->external_name());
1781 }
1782 }
1783
1784
1785 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1786 java_lang_Thread::set_interrupted(threadObj(), true);
1787 this->interrupt();
1788 }
1789
1790
1791 // External suspension mechanism.
1792 //
1793 // Guarantees on return (for a valid target thread):
1794 // - Target thread will not execute any new bytecode.
1795 // - Target thread will not enter any new monitors.
1796 //
1797 bool JavaThread::java_suspend() {
1798 ThreadsListHandle tlh;
1799 if (!tlh.includes(this)) {
1800 log_trace(thread, suspend)("JavaThread:" INTPTR_FORMAT " not on ThreadsList, no suspension", p2i(this));
1801 return false;
1802 }
1803 return this->handshake_state()->suspend();
1804 }
1805
1806 bool JavaThread::java_resume() {
1807 ThreadsListHandle tlh;
1808 if (!tlh.includes(this)) {
1809 log_trace(thread, suspend)("JavaThread:" INTPTR_FORMAT " not on ThreadsList, nothing to resume", p2i(this));
1810 return false;
1811 }
1812 return this->handshake_state()->resume();
1813 }
1814
1815 // Wait for another thread to perform object reallocation and relocking on behalf of
1816 // this thread.
1817 // Raw thread state transition to _thread_blocked and back again to the original
1818 // state before returning are performed. The current thread is required to
1819 // change to _thread_blocked in order to be seen to be safepoint/handshake safe
1820 // whilst suspended and only after becoming handshake safe, the other thread can
1821 // complete the handshake used to synchronize with this thread and then perform
1822 // the reallocation and relocking. We cannot use the thread state transition
1823 // helpers because we arrive here in various states and also because the helpers
1824 // indirectly call this method. After leaving _thread_blocked we have to check
1825 // for safepoint/handshake, except if _thread_in_native. The thread is safe
1826 // without blocking then. Allowed states are enumerated in
1827 // SafepointSynchronize::block(). See also EscapeBarrier::sync_and_suspend_*()
1828
1829 void JavaThread::wait_for_object_deoptimization() {
1830 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1831 assert(this == Thread::current(), "invariant");
1832 JavaThreadState state = thread_state();
1833
1834 bool spin_wait = os::is_MP();
1835 do {
1836 set_thread_state(_thread_blocked);
1837 // Wait for object deoptimization if requested.
1838 if (spin_wait) {
1839 // A single deoptimization is typically very short. Microbenchmarks
1840 // showed 5% better performance when spinning.
1841 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1842 SpinYield spin(spin_limit);
1843 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1844 spin.wait();
1845 }
1846 // Spin just once
1847 spin_wait = false;
1848 } else {
1849 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1850 if (is_obj_deopt_suspend()) {
1851 ml.wait();
1852 }
1853 }
1854 // The current thread could have been suspended again. We have to check for
1855 // suspend after restoring the saved state. Without this the current thread
1856 // might return to _thread_in_Java and execute bytecode.
1857 set_thread_state_fence(state);
1858
1859 if (state != _thread_in_native) {
1860 SafepointMechanism::process_if_requested(this);
1861 }
1862 // A handshake for obj. deoptimization suspend could have been processed so
1863 // we must check after processing.
1864 } while (is_obj_deopt_suspend());
1865 }
1866
1867 #ifdef ASSERT
1868 // Verify the JavaThread has not yet been published in the Threads::list, and
1869 // hence doesn't need protection from concurrent access at this stage.
1870 void JavaThread::verify_not_published() {
1871 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1872 // since an unpublished JavaThread doesn't participate in the
1873 // Thread-SMR protocol for keeping a ThreadsList alive.
1874 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1875 }
1876 #endif
1877
1878 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1879 // pending, when _suspend_flags is non-zero or when we need to process a stack
1880 // watermark. Also check for pending async exceptions (except unsafe access error).
1881 // Note only the native==>Java barriers can call this function when thread state
1882 // is _thread_in_native_trans.
1883 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1884 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1885 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1886
1887 // Enable WXWrite: called directly from interpreter native wrapper.
1888 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1889
1890 SafepointMechanism::process_if_requested_with_exit_check(thread, false /* check asyncs */);
1891
1892 // After returning from native, it could be that the stack frames are not
1893 // yet safe to use. We catch such situations in the subsequent stack watermark
1894 // barrier, which will trap unsafe stack frames.
1895 StackWatermarkSet::before_unwind(thread);
1896
1897 if (thread->has_async_exception_condition(false /* check unsafe access error */)) {
1898 // We are in _thread_in_native_trans state, don't handle unsafe
1899 // access error since that may block.
1900 thread->check_and_handle_async_exceptions();
1901 }
1902 }
1903
1904 #ifndef PRODUCT
1905 // Deoptimization
1906 // Function for testing deoptimization
1907 void JavaThread::deoptimize() {
1908 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1909 bool deopt = false; // Dump stack only if a deopt actually happens.
1910 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1911 // Iterate over all frames in the thread and deoptimize
1912 for (; !fst.is_done(); fst.next()) {
1913 if (fst.current()->can_be_deoptimized()) {
1914
1915 if (only_at) {
1916 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1917 // consists of comma or carriage return separated numbers so
1918 // search for the current bci in that string.
1919 address pc = fst.current()->pc();
1920 nmethod* nm = (nmethod*) fst.current()->cb();
1921 ScopeDesc* sd = nm->scope_desc_at(pc);
1922 char buffer[8];
1923 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1924 size_t len = strlen(buffer);
1925 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1926 while (found != NULL) {
1927 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1928 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1929 // Check that the bci found is bracketed by terminators.
1930 break;
1931 }
1932 found = strstr(found + 1, buffer);
1933 }
1934 if (!found) {
1935 continue;
1936 }
1937 }
1938
1939 if (DebugDeoptimization && !deopt) {
1940 deopt = true; // One-time only print before deopt
1941 tty->print_cr("[BEFORE Deoptimization]");
1942 trace_frames();
1943 trace_stack();
1944 }
1945 Deoptimization::deoptimize(this, *fst.current());
1946 }
1947 }
1948
1949 if (DebugDeoptimization && deopt) {
1950 tty->print_cr("[AFTER Deoptimization]");
1951 trace_frames();
1952 }
1953 }
1954
1955
1956 // Make zombies
1957 void JavaThread::make_zombies() {
1958 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1959 if (fst.current()->can_be_deoptimized()) {
1960 // it is a Java nmethod
1961 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1962 nm->make_not_entrant();
1963 }
1964 }
1965 }
1966 #endif // PRODUCT
1967
1968
1969 void JavaThread::deoptimize_marked_methods() {
1970 if (!has_last_Java_frame()) return;
1971 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1972 for (; !fst.is_done(); fst.next()) {
1973 if (fst.current()->should_be_deoptimized()) {
1974 Deoptimization::deoptimize(this, *fst.current());
1975 }
1976 }
1977 }
1978
1979 #ifdef ASSERT
1980 void JavaThread::verify_frame_info() {
1981 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1982 (has_last_Java_frame() && java_call_counter() > 0),
1983 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1984 has_last_Java_frame() ? "true" : "false", java_call_counter());
1985 }
1986 #endif
1987
1988 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1989 // Verify that the deferred card marks have been flushed.
1990 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1991
1992 // Traverse the GCHandles
1993 Thread::oops_do_no_frames(f, cf);
1994
1995 DEBUG_ONLY(verify_frame_info();)
1996
1997 if (has_last_Java_frame()) {
1998 // Traverse the monitor chunks
1999 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2000 chunk->oops_do(f);
2001 }
2002 }
2003
2004 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2005 // If we have deferred set_locals there might be oops waiting to be
2006 // written
2007 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
2008 if (list != NULL) {
2009 for (int i = 0; i < list->length(); i++) {
2010 list->at(i)->oops_do(f);
2011 }
2012 }
2013
2014 // Traverse instance variables at the end since the GC may be moving things
2015 // around using this function
2016 f->do_oop((oop*) &_vm_result);
2017 f->do_oop((oop*) &_exception_oop);
2018 f->do_oop((oop*) &_pending_async_exception);
2019 #if INCLUDE_JVMCI
2020 f->do_oop((oop*) &_jvmci_reserved_oop0);
2021 #endif
2022
2023 if (jvmti_thread_state() != NULL) {
2024 jvmti_thread_state()->oops_do(f, cf);
2025 }
2026 }
2027
2028 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
2029 if (!has_last_Java_frame()) {
2030 return;
2031 }
2032 // Finish any pending lazy GC activity for the frames
2033 StackWatermarkSet::finish_processing(this, NULL /* context */, StackWatermarkKind::gc);
2034 // Traverse the execution stack
2035 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
2036 fst.current()->oops_do(f, cf, fst.register_map());
2037 }
2038 }
2039
2040 #ifdef ASSERT
2041 void JavaThread::verify_states_for_handshake() {
2042 // This checks that the thread has a correct frame state during a handshake.
2043 verify_frame_info();
2044 }
2045 #endif
2046
2047 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2048 DEBUG_ONLY(verify_frame_info();)
2049
2050 if (has_last_Java_frame()) {
2051 // Traverse the execution stack
2052 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2053 fst.current()->nmethods_do(cf);
2054 }
2055 }
2056
2057 if (jvmti_thread_state() != NULL) {
2058 jvmti_thread_state()->nmethods_do(cf);
2059 }
2060 }
2061
2062 void JavaThread::metadata_do(MetadataClosure* f) {
2063 if (has_last_Java_frame()) {
2064 // Traverse the execution stack to call f() on the methods in the stack
2065 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2066 fst.current()->metadata_do(f);
2067 }
2068 } else if (is_Compiler_thread()) {
2069 // need to walk ciMetadata in current compile tasks to keep alive.
2070 CompilerThread* ct = (CompilerThread*)this;
2071 if (ct->env() != NULL) {
2072 ct->env()->metadata_do(f);
2073 }
2074 CompileTask* task = ct->task();
2075 if (task != NULL) {
2076 task->metadata_do(f);
2077 }
2078 }
2079 }
2080
2081 // Printing
2082 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2083 switch (_thread_state) {
2084 case _thread_uninitialized: return "_thread_uninitialized";
2085 case _thread_new: return "_thread_new";
2086 case _thread_new_trans: return "_thread_new_trans";
2087 case _thread_in_native: return "_thread_in_native";
2088 case _thread_in_native_trans: return "_thread_in_native_trans";
2089 case _thread_in_vm: return "_thread_in_vm";
2090 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2091 case _thread_in_Java: return "_thread_in_Java";
2092 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2093 case _thread_blocked: return "_thread_blocked";
2094 case _thread_blocked_trans: return "_thread_blocked_trans";
2095 default: return "unknown thread state";
2096 }
2097 }
2098
2099 #ifndef PRODUCT
2100 void JavaThread::print_thread_state_on(outputStream *st) const {
2101 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2102 };
2103 #endif // PRODUCT
2104
2105 // Called by Threads::print() for VM_PrintThreads operation
2106 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
2107 st->print_raw("\"");
2108 st->print_raw(get_thread_name());
2109 st->print_raw("\" ");
2110 oop thread_oop = threadObj();
2111 if (thread_oop != NULL) {
2112 st->print("#" INT64_FORMAT " ", (int64_t)java_lang_Thread::thread_id(thread_oop));
2113 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2114 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2115 }
2116 Thread::print_on(st, print_extended_info);
2117 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2118 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2119 if (thread_oop != NULL) {
2120 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2121 }
2122 #ifndef PRODUCT
2123 _safepoint_state->print_on(st);
2124 #endif // PRODUCT
2125 if (is_Compiler_thread()) {
2126 CompileTask *task = ((CompilerThread*)this)->task();
2127 if (task != NULL) {
2128 st->print(" Compiling: ");
2129 task->print(st, NULL, true, false);
2130 } else {
2131 st->print(" No compile task");
2132 }
2133 st->cr();
2134 }
2135 }
2136
2137 void JavaThread::print() const { print_on(tty); }
2138
2139 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
2140 st->print("%s", get_thread_name_string(buf, buflen));
2141 }
2142
2143 // Called by fatal error handler. The difference between this and
2144 // JavaThread::print() is that we can't grab lock or allocate memory.
2145 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2146 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2147 oop thread_obj = threadObj();
2148 if (thread_obj != NULL) {
2149 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2150 }
2151 st->print(" [");
2152 st->print("%s", _get_thread_state_name(_thread_state));
2153 if (osthread()) {
2154 st->print(", id=%d", osthread()->thread_id());
2155 }
2156 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2157 p2i(stack_end()), p2i(stack_base()));
2158 st->print("]");
2159
2160 ThreadsSMRSupport::print_info_on(this, st);
2161 return;
2162 }
2163
2164
2165 // Verification
2166
2167 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2168 // ignore if there is no stack
2169 if (!has_last_Java_frame()) return;
2170 // traverse the stack frames. Starts from top frame.
2171 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2172 frame* fr = fst.current();
2173 f(fr, fst.register_map());
2174 }
2175 }
2176
2177 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2178
2179 void JavaThread::verify() {
2180 // Verify oops in the thread.
2181 oops_do(&VerifyOopClosure::verify_oop, NULL);
2182
2183 // Verify the stack frames.
2184 frames_do(frame_verify);
2185 }
2186
2187 // CR 6300358 (sub-CR 2137150)
2188 // Most callers of this method assume that it can't return NULL but a
2189 // thread may not have a name whilst it is in the process of attaching to
2190 // the VM - see CR 6412693, and there are places where a JavaThread can be
2191 // seen prior to having its threadObj set (e.g., JNI attaching threads and
2192 // if vm exit occurs during initialization). These cases can all be accounted
2193 // for such that this method never returns NULL.
2194 const char* JavaThread::get_thread_name() const {
2195 if (Thread::is_JavaThread_protected(this)) {
2196 // The target JavaThread is protected so get_thread_name_string() is safe:
2197 return get_thread_name_string();
2198 }
2199
2200 // The target JavaThread is not protected so we return the default:
2201 return Thread::name();
2202 }
2203
2204 // Returns a non-NULL representation of this thread's name, or a suitable
2205 // descriptive string if there is no set name.
2206 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2207 const char* name_str;
2208 oop thread_obj = threadObj();
2209 if (thread_obj != NULL) {
2210 oop name = java_lang_Thread::name(thread_obj);
2211 if (name != NULL) {
2212 if (buf == NULL) {
2213 name_str = java_lang_String::as_utf8_string(name);
2214 } else {
2215 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
2216 }
2217 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2218 name_str = "<no-name - thread is attaching>";
2219 } else {
2220 name_str = Thread::name();
2221 }
2222 } else {
2223 name_str = Thread::name();
2224 }
2225 assert(name_str != NULL, "unexpected NULL thread name");
2226 return name_str;
2227 }
2228
2229 // Helper to extract the name from the thread oop for logging.
2230 const char* JavaThread::name_for(oop thread_obj) {
2231 assert(thread_obj != NULL, "precondition");
2232 oop name = java_lang_Thread::name(thread_obj);
2233 const char* name_str;
2234 if (name != NULL) {
2235 name_str = java_lang_String::as_utf8_string(name);
2236 } else {
2237 name_str = "<un-named>";
2238 }
2239 return name_str;
2240 }
2241
2242 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2243
2244 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2245 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
2246 // Link Java Thread object <-> C++ Thread
2247
2248 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2249 // and put it into a new Handle. The Handle "thread_oop" can then
2250 // be used to pass the C++ thread object to other methods.
2251
2252 // Set the Java level thread object (jthread) field of the
2253 // new thread (a JavaThread *) to C++ thread object using the
2254 // "thread_oop" handle.
2255
2256 // Set the thread field (a JavaThread *) of the
2257 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2258
2259 Handle thread_oop(Thread::current(),
2260 JNIHandles::resolve_non_null(jni_thread));
2261 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
2262 "must be initialized");
2263 set_threadObj(thread_oop());
2264
2265 if (prio == NoPriority) {
2266 prio = java_lang_Thread::priority(thread_oop());
2267 assert(prio != NoPriority, "A valid priority should be present");
2268 }
2269
2270 // Push the Java priority down to the native thread; needs Threads_lock
2271 Thread::set_priority(this, prio);
2272
2273 // Add the new thread to the Threads list and set it in motion.
2274 // We must have threads lock in order to call Threads::add.
2275 // It is crucial that we do not block before the thread is
2276 // added to the Threads list for if a GC happens, then the java_thread oop
2277 // will not be visited by GC.
2278 Threads::add(this);
2279 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
2280 // on a ThreadsList. We don't want to wait for the release when the
2281 // Theads_lock is dropped somewhere in the caller since the JavaThread*
2282 // is already visible to JVM/TI via the ThreadsList.
2283 java_lang_Thread::release_set_thread(thread_oop(), this);
2284 }
2285
2286 oop JavaThread::current_park_blocker() {
2287 // Support for JSR-166 locks
2288 oop thread_oop = threadObj();
2289 if (thread_oop != NULL) {
2290 return java_lang_Thread::park_blocker(thread_oop);
2291 }
2292 return NULL;
2293 }
2294
2295 // Print current stack trace for checked JNI warnings and JNI fatal errors.
2296 // This is the external format, selecting the platform
2297 // as applicable, and allowing for a native-only stack.
2298 void JavaThread::print_jni_stack() {
2299 assert(this == JavaThread::current(), "Can't print stack of other threads");
2300 if (!has_last_Java_frame()) {
2301 ResourceMark rm(this);
2302 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
2303 if (buf == nullptr) {
2304 tty->print_cr("Unable to print native stack - out of memory");
2305 return;
2306 }
2307 frame f = os::current_frame();
2308 VMError::print_native_stack(tty, f, this,
2309 buf, O_BUFLEN);
2310 } else {
2311 print_stack_on(tty);
2312 }
2313 }
2314
2315 void JavaThread::print_stack_on(outputStream* st) {
2316 if (!has_last_Java_frame()) return;
2317
2318 Thread* current_thread = Thread::current();
2319 ResourceMark rm(current_thread);
2320 HandleMark hm(current_thread);
2321
2322 RegisterMap reg_map(this);
2323 vframe* start_vf = last_java_vframe(®_map);
2324 int count = 0;
2325 for (vframe* f = start_vf; f != NULL; f = f->sender()) {
2326 if (f->is_java_frame()) {
2327 javaVFrame* jvf = javaVFrame::cast(f);
2328 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2329
2330 // Print out lock information
2331 if (JavaMonitorsInStackTrace) {
2332 jvf->print_lock_info_on(st, count);
2333 }
2334 } else {
2335 // Ignore non-Java frames
2336 }
2337
2338 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
2339 count++;
2340 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
2341 }
2342 }
2343
2344
2345 // JVMTI PopFrame support
2346 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2347 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2348 if (in_bytes(size_in_bytes) != 0) {
2349 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
2350 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2351 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2352 }
2353 }
2354
2355 void* JavaThread::popframe_preserved_args() {
2356 return _popframe_preserved_args;
2357 }
2358
2359 ByteSize JavaThread::popframe_preserved_args_size() {
2360 return in_ByteSize(_popframe_preserved_args_size);
2361 }
2362
2363 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2364 int sz = in_bytes(popframe_preserved_args_size());
2365 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2366 return in_WordSize(sz / wordSize);
2367 }
2368
2369 void JavaThread::popframe_free_preserved_args() {
2370 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2371 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
2372 _popframe_preserved_args = NULL;
2373 _popframe_preserved_args_size = 0;
2374 }
2375
2376 #ifndef PRODUCT
2377
2378 void JavaThread::trace_frames() {
2379 tty->print_cr("[Describe stack]");
2380 int frame_no = 1;
2381 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2382 tty->print(" %d. ", frame_no++);
2383 fst.current()->print_value_on(tty, this);
2384 tty->cr();
2385 }
2386 }
2387
2388 class PrintAndVerifyOopClosure: public OopClosure {
2389 protected:
2390 template <class T> inline void do_oop_work(T* p) {
2391 oop obj = RawAccess<>::oop_load(p);
2392 if (obj == NULL) return;
2393 tty->print(INTPTR_FORMAT ": ", p2i(p));
2394 if (oopDesc::is_oop_or_null(obj)) {
2395 if (obj->is_objArray()) {
2396 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
2397 } else {
2398 obj->print();
2399 }
2400 } else {
2401 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
2402 }
2403 tty->cr();
2404 }
2405 public:
2406 virtual void do_oop(oop* p) { do_oop_work(p); }
2407 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
2408 };
2409
2410 #ifdef ASSERT
2411 // Print or validate the layout of stack frames
2412 void JavaThread::print_frame_layout(int depth, bool validate_only) {
2413 ResourceMark rm;
2414 PreserveExceptionMark pm(this);
2415 FrameValues values;
2416 int frame_no = 0;
2417 for (StackFrameStream fst(this, false /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2418 fst.current()->describe(values, ++frame_no);
2419 if (depth == frame_no) break;
2420 }
2421 if (validate_only) {
2422 values.validate();
2423 } else {
2424 tty->print_cr("[Describe stack layout]");
2425 values.print(this);
2426 }
2427 }
2428 #endif
2429
2430 void JavaThread::trace_stack_from(vframe* start_vf) {
2431 ResourceMark rm;
2432 int vframe_no = 1;
2433 for (vframe* f = start_vf; f; f = f->sender()) {
2434 if (f->is_java_frame()) {
2435 javaVFrame::cast(f)->print_activation(vframe_no++);
2436 } else {
2437 f->print();
2438 }
2439 if (vframe_no > StackPrintLimit) {
2440 tty->print_cr("...<more frames>...");
2441 return;
2442 }
2443 }
2444 }
2445
2446
2447 void JavaThread::trace_stack() {
2448 if (!has_last_Java_frame()) return;
2449 Thread* current_thread = Thread::current();
2450 ResourceMark rm(current_thread);
2451 HandleMark hm(current_thread);
2452 RegisterMap reg_map(this);
2453 trace_stack_from(last_java_vframe(®_map));
2454 }
2455
2456
2457 #endif // PRODUCT
2458
2459
2460 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2461 assert(reg_map != NULL, "a map must be given");
2462 frame f = last_frame();
2463 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
2464 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2465 }
2466 return NULL;
2467 }
2468
2469
2470 Klass* JavaThread::security_get_caller_class(int depth) {
2471 vframeStream vfst(this);
2472 vfst.security_get_caller_frame(depth);
2473 if (!vfst.at_end()) {
2474 return vfst.method()->method_holder();
2475 }
2476 return NULL;
2477 }
2478
2479 // java.lang.Thread.sleep support
2480 // Returns true if sleep time elapsed as expected, and false
2481 // if the thread was interrupted.
2482 bool JavaThread::sleep(jlong millis) {
2483 assert(this == Thread::current(), "thread consistency check");
2484
2485 ParkEvent * const slp = this->_SleepEvent;
2486 // Because there can be races with thread interruption sending an unpark()
2487 // to the event, we explicitly reset it here to avoid an immediate return.
2488 // The actual interrupt state will be checked before we park().
2489 slp->reset();
2490 // Thread interruption establishes a happens-before ordering in the
2491 // Java Memory Model, so we need to ensure we synchronize with the
2492 // interrupt state.
2493 OrderAccess::fence();
2494
2495 jlong prevtime = os::javaTimeNanos();
2496
2497 for (;;) {
2498 // interruption has precedence over timing out
2499 if (this->is_interrupted(true)) {
2500 return false;
2501 }
2502
2503 if (millis <= 0) {
2504 return true;
2505 }
2506
2507 {
2508 ThreadBlockInVM tbivm(this);
2509 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2510 slp->park(millis);
2511 }
2512
2513 // Update elapsed time tracking
2514 jlong newtime = os::javaTimeNanos();
2515 if (newtime - prevtime < 0) {
2516 // time moving backwards, should only happen if no monotonic clock
2517 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2518 assert(false,
2519 "unexpected time moving backwards detected in JavaThread::sleep()");
2520 } else {
2521 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2522 }
2523 prevtime = newtime;
2524 }
2525 }
2526
2527
2528 // ======= Threads ========
2529
2530 // The Threads class links together all active threads, and provides
2531 // operations over all threads. It is protected by the Threads_lock,
2532 // which is also used in other global contexts like safepointing.
2533 // ThreadsListHandles are used to safely perform operations on one
2534 // or more threads without the risk of the thread exiting during the
2535 // operation.
2536 //
2537 // Note: The Threads_lock is currently more widely used than we
2538 // would like. We are actively migrating Threads_lock uses to other
2539 // mechanisms in order to reduce Threads_lock contention.
2540
2541 int Threads::_number_of_threads = 0;
2542 int Threads::_number_of_non_daemon_threads = 0;
2543 int Threads::_return_code = 0;
2544 uintx Threads::_thread_claim_token = 1; // Never zero.
2545 size_t JavaThread::_stack_size_at_create = 0;
2546
2547 #ifdef ASSERT
2548 bool Threads::_vm_complete = false;
2549 #endif
2550
2551 static inline void *prefetch_and_load_ptr(void **addr, intx prefetch_interval) {
2552 Prefetch::read((void*)addr, prefetch_interval);
2553 return *addr;
2554 }
2555
2556 // Possibly the ugliest for loop the world has seen. C++ does not allow
2557 // multiple types in the declaration section of the for loop. In this case
2558 // we are only dealing with pointers and hence can cast them. It looks ugly
2559 // but macros are ugly and therefore it's fine to make things absurdly ugly.
2560 #define DO_JAVA_THREADS(LIST, X) \
2561 for (JavaThread *MACRO_scan_interval = (JavaThread*)(uintptr_t)PrefetchScanIntervalInBytes, \
2562 *MACRO_list = (JavaThread*)(LIST), \
2563 **MACRO_end = ((JavaThread**)((ThreadsList*)MACRO_list)->threads()) + ((ThreadsList*)MACRO_list)->length(), \
2564 **MACRO_current_p = (JavaThread**)((ThreadsList*)MACRO_list)->threads(), \
2565 *X = (JavaThread*)prefetch_and_load_ptr((void**)MACRO_current_p, (intx)MACRO_scan_interval); \
2566 MACRO_current_p != MACRO_end; \
2567 MACRO_current_p++, \
2568 X = (JavaThread*)prefetch_and_load_ptr((void**)MACRO_current_p, (intx)MACRO_scan_interval))
2569
2570 // All JavaThreads
2571 #define ALL_JAVA_THREADS(X) DO_JAVA_THREADS(ThreadsSMRSupport::get_java_thread_list(), X)
2572
2573 // All NonJavaThreads (i.e., every non-JavaThread in the system).
2574 void Threads::non_java_threads_do(ThreadClosure* tc) {
2575 NoSafepointVerifier nsv;
2576 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
2577 tc->do_thread(njti.current());
2578 }
2579 }
2580
2581 // All JavaThreads
2582 void Threads::java_threads_do(ThreadClosure* tc) {
2583 assert_locked_or_safepoint(Threads_lock);
2584 // ALL_JAVA_THREADS iterates through all JavaThreads.
2585 ALL_JAVA_THREADS(p) {
2586 tc->do_thread(p);
2587 }
2588 }
2589
2590 void Threads::java_threads_and_vm_thread_do(ThreadClosure* tc) {
2591 assert_locked_or_safepoint(Threads_lock);
2592 java_threads_do(tc);
2593 tc->do_thread(VMThread::vm_thread());
2594 }
2595
2596 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
2597 void Threads::threads_do(ThreadClosure* tc) {
2598 assert_locked_or_safepoint(Threads_lock);
2599 java_threads_do(tc);
2600 non_java_threads_do(tc);
2601 }
2602
2603 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
2604 uintx claim_token = Threads::thread_claim_token();
2605 ALL_JAVA_THREADS(p) {
2606 if (p->claim_threads_do(is_par, claim_token)) {
2607 tc->do_thread(p);
2608 }
2609 }
2610 VMThread* vmt = VMThread::vm_thread();
2611 if (vmt->claim_threads_do(is_par, claim_token)) {
2612 tc->do_thread(vmt);
2613 }
2614 }
2615
2616 // The system initialization in the library has three phases.
2617 //
2618 // Phase 1: java.lang.System class initialization
2619 // java.lang.System is a primordial class loaded and initialized
2620 // by the VM early during startup. java.lang.System.<clinit>
2621 // only does registerNatives and keeps the rest of the class
2622 // initialization work later until thread initialization completes.
2623 //
2624 // System.initPhase1 initializes the system properties, the static
2625 // fields in, out, and err. Set up java signal handlers, OS-specific
2626 // system settings, and thread group of the main thread.
2627 static void call_initPhase1(TRAPS) {
2628 Klass* klass = vmClasses::System_klass();
2629 JavaValue result(T_VOID);
2630 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
2631 vmSymbols::void_method_signature(), CHECK);
2632 }
2633
2634 // Phase 2. Module system initialization
2635 // This will initialize the module system. Only java.base classes
2636 // can be loaded until phase 2 completes.
2637 //
2638 // Call System.initPhase2 after the compiler initialization and jsr292
2639 // classes get initialized because module initialization runs a lot of java
2640 // code, that for performance reasons, should be compiled. Also, this will
2641 // enable the startup code to use lambda and other language features in this
2642 // phase and onward.
2643 //
2644 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
2645 static void call_initPhase2(TRAPS) {
2646 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
2647
2648 Klass* klass = vmClasses::System_klass();
2649
2650 JavaValue result(T_INT);
2651 JavaCallArguments args;
2652 args.push_int(DisplayVMOutputToStderr);
2653 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
2654 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
2655 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
2656 if (result.get_jint() != JNI_OK) {
2657 vm_exit_during_initialization(); // no message or exception
2658 }
2659
2660 universe_post_module_init();
2661 }
2662
2663 // Phase 3. final setup - set security manager, system class loader and TCCL
2664 //
2665 // This will instantiate and set the security manager, set the system class
2666 // loader as well as the thread context class loader. The security manager
2667 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
2668 // other modules or the application's classpath.
2669 static void call_initPhase3(TRAPS) {
2670 Klass* klass = vmClasses::System_klass();
2671 JavaValue result(T_VOID);
2672 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
2673 vmSymbols::void_method_signature(), CHECK);
2674 }
2675
2676 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
2677 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
2678
2679 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
2680 create_vm_init_libraries();
2681 }
2682
2683 initialize_class(vmSymbols::java_lang_String(), CHECK);
2684
2685 // Inject CompactStrings value after the static initializers for String ran.
2686 java_lang_String::set_compact_strings(CompactStrings);
2687
2688 // Initialize java_lang.System (needed before creating the thread)
2689 initialize_class(vmSymbols::java_lang_System(), CHECK);
2690 // The VM creates & returns objects of this class. Make sure it's initialized.
2691 initialize_class(vmSymbols::java_lang_Class(), CHECK);
2692 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
2693 Handle thread_group = create_initial_thread_group(CHECK);
2694 Universe::set_main_thread_group(thread_group());
2695 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
2696 create_initial_thread(thread_group, main_thread, CHECK);
2697
2698 // The VM creates objects of this class.
2699 initialize_class(vmSymbols::java_lang_Module(), CHECK);
2700
2701 #ifdef ASSERT
2702 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
2703 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
2704 #endif
2705
2706 // initialize the hardware-specific constants needed by Unsafe
2707 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
2708 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
2709
2710 // The VM preresolves methods to these classes. Make sure that they get initialized
2711 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
2712 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
2713
2714 // Phase 1 of the system initialization in the library, java.lang.System class initialization
2715 call_initPhase1(CHECK);
2716
2717 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
2718 // Some values are actually configure-time constants but some can be set via the jlink tool and
2719 // so must be read dynamically. We treat them all the same.
2720 InstanceKlass* ik = SystemDictionary::find_instance_klass(vmSymbols::java_lang_VersionProps(),
2721 Handle(), Handle());
2722 {
2723 ResourceMark rm(main_thread);
2724 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
2725
2726 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
2727
2728 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
2729
2730 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
2731
2732 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
2733 }
2734
2735 // an instance of OutOfMemory exception has been allocated earlier
2736 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
2737 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
2738 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
2739 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
2740 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
2741 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
2742 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
2743 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
2744 }
2745
2746 void Threads::initialize_jsr292_core_classes(TRAPS) {
2747 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
2748
2749 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
2750 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
2751 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
2752 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
2753 }
2754
2755 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2756 extern void JDK_Version_init();
2757
2758 // Preinitialize version info.
2759 VM_Version::early_initialize();
2760
2761 // Check version
2762 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2763
2764 // Initialize library-based TLS
2765 ThreadLocalStorage::init();
2766
2767 // Initialize the output stream module
2768 ostream_init();
2769
2770 // Process java launcher properties.
2771 Arguments::process_sun_java_launcher_properties(args);
2772
2773 // Initialize the os module
2774 os::init();
2775
2776 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
2777
2778 // Record VM creation timing statistics
2779 TraceVmCreationTime create_vm_timer;
2780 create_vm_timer.start();
2781
2782 // Initialize system properties.
2783 Arguments::init_system_properties();
2784
2785 // So that JDK version can be used as a discriminator when parsing arguments
2786 JDK_Version_init();
2787
2788 // Update/Initialize System properties after JDK version number is known
2789 Arguments::init_version_specific_system_properties();
2790
2791 // Make sure to initialize log configuration *before* parsing arguments
2792 LogConfiguration::initialize(create_vm_timer.begin_time());
2793
2794 // Parse arguments
2795 // Note: this internally calls os::init_container_support()
2796 jint parse_result = Arguments::parse(args);
2797 if (parse_result != JNI_OK) return parse_result;
2798
2799 #if INCLUDE_NMT
2800 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
2801 MemTracker::initialize();
2802 #endif // INCLUDE_NMT
2803
2804 os::init_before_ergo();
2805
2806 jint ergo_result = Arguments::apply_ergo();
2807 if (ergo_result != JNI_OK) return ergo_result;
2808
2809 // Final check of all ranges after ergonomics which may change values.
2810 if (!JVMFlagLimit::check_all_ranges()) {
2811 return JNI_EINVAL;
2812 }
2813
2814 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
2815 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
2816 if (!constraint_result) {
2817 return JNI_EINVAL;
2818 }
2819
2820 if (PauseAtStartup) {
2821 os::pause();
2822 }
2823
2824 HOTSPOT_VM_INIT_BEGIN();
2825
2826 // Timing (must come after argument parsing)
2827 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
2828
2829 // Initialize the os module after parsing the args
2830 jint os_init_2_result = os::init_2();
2831 if (os_init_2_result != JNI_OK) return os_init_2_result;
2832
2833 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
2834 // Initialize assert poison page mechanism.
2835 if (ShowRegistersOnAssert) {
2836 initialize_assert_poison();
2837 }
2838 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
2839
2840 SafepointMechanism::initialize();
2841
2842 jint adjust_after_os_result = Arguments::adjust_after_os();
2843 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
2844
2845 // Initialize output stream logging
2846 ostream_init_log();
2847
2848 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2849 // Must be before create_vm_init_agents()
2850 if (Arguments::init_libraries_at_startup()) {
2851 convert_vm_init_libraries_to_agents();
2852 }
2853
2854 // Launch -agentlib/-agentpath and converted -Xrun agents
2855 if (Arguments::init_agents_at_startup()) {
2856 create_vm_init_agents();
2857 }
2858
2859 // Initialize Threads state
2860 _number_of_threads = 0;
2861 _number_of_non_daemon_threads = 0;
2862
2863 // Initialize global data structures and create system classes in heap
2864 vm_init_globals();
2865
2866 #if INCLUDE_JVMCI
2867 if (JVMCICounterSize > 0) {
2868 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
2869 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
2870 } else {
2871 JavaThread::_jvmci_old_thread_counters = NULL;
2872 }
2873 #endif // INCLUDE_JVMCI
2874
2875 // Initialize OopStorage for threadObj
2876 _thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
2877
2878 // Attach the main thread to this os thread
2879 JavaThread* main_thread = new JavaThread();
2880 main_thread->set_thread_state(_thread_in_vm);
2881 main_thread->initialize_thread_current();
2882 // must do this before set_active_handles
2883 main_thread->record_stack_base_and_size();
2884 main_thread->register_thread_stack_with_NMT();
2885 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2886 MACOS_AARCH64_ONLY(main_thread->init_wx());
2887
2888 if (!main_thread->set_as_starting_thread()) {
2889 vm_shutdown_during_initialization(
2890 "Failed necessary internal allocation. Out of swap space");
2891 main_thread->smr_delete();
2892 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2893 return JNI_ENOMEM;
2894 }
2895
2896 // Enable guard page *after* os::create_main_thread(), otherwise it would
2897 // crash Linux VM, see notes in os_linux.cpp.
2898 main_thread->stack_overflow_state()->create_stack_guard_pages();
2899
2900 // Initialize Java-Level synchronization subsystem
2901 ObjectMonitor::Initialize();
2902 ObjectSynchronizer::initialize();
2903
2904 // Initialize global modules
2905 jint status = init_globals();
2906 if (status != JNI_OK) {
2907 main_thread->smr_delete();
2908 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2909 return status;
2910 }
2911
2912 JFR_ONLY(Jfr::on_create_vm_1();)
2913
2914 // Should be done after the heap is fully created
2915 main_thread->cache_global_variables();
2916
2917 { MutexLocker mu(Threads_lock);
2918 Threads::add(main_thread);
2919 }
2920
2921 // Any JVMTI raw monitors entered in onload will transition into
2922 // real raw monitor. VM is setup enough here for raw monitor enter.
2923 JvmtiExport::transition_pending_onload_raw_monitors();
2924
2925 // Create the VMThread
2926 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
2927
2928 VMThread::create();
2929 Thread* vmthread = VMThread::vm_thread();
2930
2931 if (!os::create_thread(vmthread, os::vm_thread)) {
2932 vm_exit_during_initialization("Cannot create VM thread. "
2933 "Out of system resources.");
2934 }
2935
2936 // Wait for the VM thread to become ready, and VMThread::run to initialize
2937 // Monitors can have spurious returns, must always check another state flag
2938 {
2939 MonitorLocker ml(Notify_lock);
2940 os::start_thread(vmthread);
2941 while (vmthread->active_handles() == NULL) {
2942 ml.wait();
2943 }
2944 }
2945 }
2946
2947 assert(Universe::is_fully_initialized(), "not initialized");
2948 if (VerifyDuringStartup) {
2949 // Make sure we're starting with a clean slate.
2950 VM_Verify verify_op;
2951 VMThread::execute(&verify_op);
2952 }
2953
2954 // We need this to update the java.vm.info property in case any flags used
2955 // to initially define it have been changed. This is needed for both CDS
2956 // since UseSharedSpaces may be changed after java.vm.info
2957 // is initially computed. See Abstract_VM_Version::vm_info_string().
2958 // This update must happen before we initialize the java classes, but
2959 // after any initialization logic that might modify the flags.
2960 Arguments::update_vm_info_property(VM_Version::vm_info_string());
2961
2962 JavaThread* THREAD = JavaThread::current(); // For exception macros.
2963 HandleMark hm(THREAD);
2964
2965 // Always call even when there are not JVMTI environments yet, since environments
2966 // may be attached late and JVMTI must track phases of VM execution
2967 JvmtiExport::enter_early_start_phase();
2968
2969 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
2970 JvmtiExport::post_early_vm_start();
2971
2972 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
2973
2974 quicken_jni_functions();
2975
2976 // No more stub generation allowed after that point.
2977 StubCodeDesc::freeze();
2978
2979 // Set flag that basic initialization has completed. Used by exceptions and various
2980 // debug stuff, that does not work until all basic classes have been initialized.
2981 set_init_completed();
2982
2983 LogConfiguration::post_initialize();
2984 Metaspace::post_initialize();
2985
2986 HOTSPOT_VM_INIT_END();
2987
2988 // record VM initialization completion time
2989 #if INCLUDE_MANAGEMENT
2990 Management::record_vm_init_completed();
2991 #endif // INCLUDE_MANAGEMENT
2992
2993 // Signal Dispatcher needs to be started before VMInit event is posted
2994 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
2995
2996 // Start Attach Listener if +StartAttachListener or it can't be started lazily
2997 if (!DisableAttachMechanism) {
2998 AttachListener::vm_start();
2999 if (StartAttachListener || AttachListener::init_at_startup()) {
3000 AttachListener::init();
3001 }
3002 }
3003
3004 // Launch -Xrun agents
3005 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3006 // back-end can launch with -Xdebug -Xrunjdwp.
3007 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3008 create_vm_init_libraries();
3009 }
3010
3011 Chunk::start_chunk_pool_cleaner_task();
3012
3013 // Start the service thread
3014 // The service thread enqueues JVMTI deferred events and does various hashtable
3015 // and other cleanups. Needs to start before the compilers start posting events.
3016 ServiceThread::initialize();
3017
3018 // Start the monitor deflation thread:
3019 MonitorDeflationThread::initialize();
3020
3021 // initialize compiler(s)
3022 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
3023 #if INCLUDE_JVMCI
3024 bool force_JVMCI_intialization = false;
3025 if (EnableJVMCI) {
3026 // Initialize JVMCI eagerly when it is explicitly requested.
3027 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
3028 force_JVMCI_intialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
3029
3030 if (!force_JVMCI_intialization) {
3031 // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking
3032 // compilations via JVMCI will not actually block until JVMCI is initialized.
3033 force_JVMCI_intialization = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation);
3034 }
3035 }
3036 #endif
3037 CompileBroker::compilation_init_phase1(CHECK_JNI_ERR);
3038 // Postpone completion of compiler initialization to after JVMCI
3039 // is initialized to avoid timeouts of blocking compilations.
3040 if (JVMCI_ONLY(!force_JVMCI_intialization) NOT_JVMCI(true)) {
3041 CompileBroker::compilation_init_phase2();
3042 }
3043 #endif
3044
3045 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
3046 // It is done after compilers are initialized, because otherwise compilations of
3047 // signature polymorphic MH intrinsics can be missed
3048 // (see SystemDictionary::find_method_handle_intrinsic).
3049 initialize_jsr292_core_classes(CHECK_JNI_ERR);
3050
3051 // This will initialize the module system. Only java.base classes can be
3052 // loaded until phase 2 completes
3053 call_initPhase2(CHECK_JNI_ERR);
3054
3055 JFR_ONLY(Jfr::on_create_vm_2();)
3056
3057 // Always call even when there are not JVMTI environments yet, since environments
3058 // may be attached late and JVMTI must track phases of VM execution
3059 JvmtiExport::enter_start_phase();
3060
3061 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3062 JvmtiExport::post_vm_start();
3063
3064 // Final system initialization including security manager and system class loader
3065 call_initPhase3(CHECK_JNI_ERR);
3066
3067 // cache the system and platform class loaders
3068 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
3069
3070 #if INCLUDE_CDS
3071 // capture the module path info from the ModuleEntryTable
3072 ClassLoader::initialize_module_path(THREAD);
3073 if (HAS_PENDING_EXCEPTION) {
3074 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
3075 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
3076 }
3077 #endif
3078
3079 #if INCLUDE_JVMCI
3080 if (force_JVMCI_intialization) {
3081 JVMCI::initialize_compiler(CHECK_JNI_ERR);
3082 CompileBroker::compilation_init_phase2();
3083 }
3084 #endif
3085
3086 if (NativeHeapTrimmer::enabled()) {
3087 NativeHeapTrimmer::initialize();
3088 }
3089
3090 // Always call even when there are not JVMTI environments yet, since environments
3091 // may be attached late and JVMTI must track phases of VM execution
3092 JvmtiExport::enter_live_phase();
3093
3094 // Make perfmemory accessible
3095 PerfMemory::set_accessible(true);
3096
3097 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3098 JvmtiExport::post_vm_initialized();
3099
3100 JFR_ONLY(Jfr::on_create_vm_3();)
3101
3102 #if INCLUDE_MANAGEMENT
3103 Management::initialize(THREAD);
3104
3105 if (HAS_PENDING_EXCEPTION) {
3106 // management agent fails to start possibly due to
3107 // configuration problem and is responsible for printing
3108 // stack trace if appropriate. Simply exit VM.
3109 vm_exit(1);
3110 }
3111 #endif // INCLUDE_MANAGEMENT
3112
3113 StatSampler::engage();
3114 if (CheckJNICalls) JniPeriodicChecker::engage();
3115
3116 BiasedLocking::init();
3117
3118 #if INCLUDE_RTM_OPT
3119 RTMLockingCounters::init();
3120 #endif
3121
3122 call_postVMInitHook(THREAD);
3123 // The Java side of PostVMInitHook.run must deal with all
3124 // exceptions and provide means of diagnosis.
3125 if (HAS_PENDING_EXCEPTION) {
3126 CLEAR_PENDING_EXCEPTION;
3127 }
3128
3129 {
3130 MutexLocker ml(PeriodicTask_lock);
3131 // Make sure the WatcherThread can be started by WatcherThread::start()
3132 // or by dynamic enrollment.
3133 WatcherThread::make_startable();
3134 // Start up the WatcherThread if there are any periodic tasks
3135 // NOTE: All PeriodicTasks should be registered by now. If they
3136 // aren't, late joiners might appear to start slowly (we might
3137 // take a while to process their first tick).
3138 if (PeriodicTask::num_tasks() > 0) {
3139 WatcherThread::start();
3140 }
3141 }
3142
3143 create_vm_timer.end();
3144 #ifdef ASSERT
3145 _vm_complete = true;
3146 #endif
3147
3148 if (DumpSharedSpaces) {
3149 MetaspaceShared::preload_and_dump();
3150 ShouldNotReachHere();
3151 }
3152
3153 return JNI_OK;
3154 }
3155
3156 // type for the Agent_OnLoad and JVM_OnLoad entry points
3157 extern "C" {
3158 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3159 }
3160 // Find a command line agent library and return its entry point for
3161 // -agentlib: -agentpath: -Xrun
3162 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3163 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent,
3164 const char *on_load_symbols[],
3165 size_t num_symbol_entries) {
3166 OnLoadEntry_t on_load_entry = NULL;
3167 void *library = NULL;
3168
3169 if (!agent->valid()) {
3170 char buffer[JVM_MAXPATHLEN];
3171 char ebuf[1024] = "";
3172 const char *name = agent->name();
3173 const char *msg = "Could not find agent library ";
3174
3175 // First check to see if agent is statically linked into executable
3176 if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
3177 library = agent->os_lib();
3178 } else if (agent->is_absolute_path()) {
3179 library = os::dll_load(name, ebuf, sizeof ebuf);
3180 if (library == NULL) {
3181 const char *sub_msg = " in absolute path, with error: ";
3182 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3183 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3184 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3185 // If we can't find the agent, exit.
3186 vm_exit_during_initialization(buf, NULL);
3187 FREE_C_HEAP_ARRAY(char, buf);
3188 }
3189 } else {
3190 // Try to load the agent from the standard dll directory
3191 if (os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
3192 name)) {
3193 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3194 }
3195 if (library == NULL) { // Try the library path directory.
3196 if (os::dll_build_name(buffer, sizeof(buffer), name)) {
3197 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3198 }
3199 if (library == NULL) {
3200 const char *sub_msg = " on the library path, with error: ";
3201 const char *sub_msg2 = "\nModule java.instrument may be missing from runtime image.";
3202
3203 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) +
3204 strlen(ebuf) + strlen(sub_msg2) + 1;
3205 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3206 if (!agent->is_instrument_lib()) {
3207 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3208 } else {
3209 jio_snprintf(buf, len, "%s%s%s%s%s", msg, name, sub_msg, ebuf, sub_msg2);
3210 }
3211 // If we can't find the agent, exit.
3212 vm_exit_during_initialization(buf, NULL);
3213 FREE_C_HEAP_ARRAY(char, buf);
3214 }
3215 }
3216 }
3217 agent->set_os_lib(library);
3218 agent->set_valid();
3219 }
3220
3221 // Find the OnLoad function.
3222 on_load_entry =
3223 CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
3224 false,
3225 on_load_symbols,
3226 num_symbol_entries));
3227 return on_load_entry;
3228 }
3229
3230 // Find the JVM_OnLoad entry point
3231 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3232 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3233 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3234 }
3235
3236 // Find the Agent_OnLoad entry point
3237 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3238 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3239 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3240 }
3241
3242 // For backwards compatibility with -Xrun
3243 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3244 // treated like -agentpath:
3245 // Must be called before agent libraries are created
3246 void Threads::convert_vm_init_libraries_to_agents() {
3247 AgentLibrary* agent;
3248 AgentLibrary* next;
3249
3250 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3251 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3252 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3253
3254 // If there is an JVM_OnLoad function it will get called later,
3255 // otherwise see if there is an Agent_OnLoad
3256 if (on_load_entry == NULL) {
3257 on_load_entry = lookup_agent_on_load(agent);
3258 if (on_load_entry != NULL) {
3259 // switch it to the agent list -- so that Agent_OnLoad will be called,
3260 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3261 Arguments::convert_library_to_agent(agent);
3262 } else {
3263 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3264 }
3265 }
3266 }
3267 }
3268
3269 // Create agents for -agentlib: -agentpath: and converted -Xrun
3270 // Invokes Agent_OnLoad
3271 // Called very early -- before JavaThreads exist
3272 void Threads::create_vm_init_agents() {
3273 extern struct JavaVM_ main_vm;
3274 AgentLibrary* agent;
3275
3276 JvmtiExport::enter_onload_phase();
3277
3278 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3279 // CDS dumping does not support native JVMTI agent.
3280 // CDS dumping supports Java agent if the AllowArchivingWithJavaAgent diagnostic option is specified.
3281 if (Arguments::is_dumping_archive()) {
3282 if(!agent->is_instrument_lib()) {
3283 vm_exit_during_cds_dumping("CDS dumping does not support native JVMTI agent, name", agent->name());
3284 } else if (!AllowArchivingWithJavaAgent) {
3285 vm_exit_during_cds_dumping(
3286 "Must enable AllowArchivingWithJavaAgent in order to run Java agent during CDS dumping");
3287 }
3288 }
3289
3290 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3291
3292 if (on_load_entry != NULL) {
3293 // Invoke the Agent_OnLoad function
3294 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3295 if (err != JNI_OK) {
3296 vm_exit_during_initialization("agent library failed to init", agent->name());
3297 }
3298 } else {
3299 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3300 }
3301 }
3302
3303 JvmtiExport::enter_primordial_phase();
3304 }
3305
3306 extern "C" {
3307 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3308 }
3309
3310 void Threads::shutdown_vm_agents() {
3311 // Send any Agent_OnUnload notifications
3312 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3313 size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
3314 extern struct JavaVM_ main_vm;
3315 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3316
3317 // Find the Agent_OnUnload function.
3318 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3319 os::find_agent_function(agent,
3320 false,
3321 on_unload_symbols,
3322 num_symbol_entries));
3323
3324 // Invoke the Agent_OnUnload function
3325 if (unload_entry != NULL) {
3326 JavaThread* thread = JavaThread::current();
3327 ThreadToNativeFromVM ttn(thread);
3328 HandleMark hm(thread);
3329 (*unload_entry)(&main_vm);
3330 }
3331 }
3332 }
3333
3334 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3335 // Invokes JVM_OnLoad
3336 void Threads::create_vm_init_libraries() {
3337 extern struct JavaVM_ main_vm;
3338 AgentLibrary* agent;
3339
3340 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3341 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3342
3343 if (on_load_entry != NULL) {
3344 // Invoke the JVM_OnLoad function
3345 JavaThread* thread = JavaThread::current();
3346 ThreadToNativeFromVM ttn(thread);
3347 HandleMark hm(thread);
3348 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3349 if (err != JNI_OK) {
3350 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3351 }
3352 } else {
3353 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3354 }
3355 }
3356 }
3357
3358
3359 // Last thread running calls java.lang.Shutdown.shutdown()
3360 void JavaThread::invoke_shutdown_hooks() {
3361 HandleMark hm(this);
3362
3363 // We could get here with a pending exception, if so clear it now or
3364 // it will cause MetaspaceShared::link_and_cleanup_shared_classes to
3365 // fail for dynamic dump.
3366 if (this->has_pending_exception()) {
3367 this->clear_pending_exception();
3368 }
3369
3370 #if INCLUDE_CDS
3371 // Link all classes for dynamic CDS dumping before vm exit.
3372 // Same operation is being done in JVM_BeforeHalt for handling the
3373 // case where the application calls System.exit().
3374 if (DynamicDumpSharedSpaces) {
3375 DynamicArchive::prepare_for_dynamic_dumping_at_exit();
3376 }
3377 #endif
3378
3379 EXCEPTION_MARK;
3380 Klass* shutdown_klass =
3381 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3382 THREAD);
3383 if (shutdown_klass != NULL) {
3384 // SystemDictionary::resolve_or_null will return null if there was
3385 // an exception. If we cannot load the Shutdown class, just don't
3386 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3387 // won't be run. Note that if a shutdown hook was registered,
3388 // the Shutdown class would have already been loaded
3389 // (Runtime.addShutdownHook will load it).
3390 JavaValue result(T_VOID);
3391 JavaCalls::call_static(&result,
3392 shutdown_klass,
3393 vmSymbols::shutdown_name(),
3394 vmSymbols::void_method_signature(),
3395 THREAD);
3396 }
3397 CLEAR_PENDING_EXCEPTION;
3398 }
3399
3400 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3401 // the program falls off the end of main(). Another VM exit path is through
3402 // vm_exit() when the program calls System.exit() to return a value or when
3403 // there is a serious error in VM. The two shutdown paths are not exactly
3404 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3405 // and VM_Exit op at VM level.
3406 //
3407 // Shutdown sequence:
3408 // + Shutdown native memory tracking if it is on
3409 // + Wait until we are the last non-daemon thread to execute
3410 // <-- every thing is still working at this moment -->
3411 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3412 // shutdown hooks
3413 // + Call before_exit(), prepare for VM exit
3414 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3415 // currently the only user of this mechanism is File.deleteOnExit())
3416 // > stop StatSampler, watcher thread,
3417 // post thread end and vm death events to JVMTI,
3418 // stop signal thread
3419 // + Call JavaThread::exit(), it will:
3420 // > release JNI handle blocks, remove stack guard pages
3421 // > remove this thread from Threads list
3422 // <-- no more Java code from this thread after this point -->
3423 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3424 // the compiler threads at safepoint
3425 // <-- do not use anything that could get blocked by Safepoint -->
3426 // + Disable tracing at JNI/JVM barriers
3427 // + Set _vm_exited flag for threads that are still running native code
3428 // + Call exit_globals()
3429 // > deletes tty
3430 // > deletes PerfMemory resources
3431 // + Delete this thread
3432 // + Return to caller
3433
3434 void Threads::destroy_vm() {
3435 JavaThread* thread = JavaThread::current();
3436
3437 #ifdef ASSERT
3438 _vm_complete = false;
3439 #endif
3440 // Wait until we are the last non-daemon thread to execute
3441 {
3442 MonitorLocker nu(Threads_lock);
3443 while (Threads::number_of_non_daemon_threads() > 1)
3444 // This wait should make safepoint checks, wait without a timeout.
3445 nu.wait(0);
3446 }
3447
3448 EventShutdown e;
3449 if (e.should_commit()) {
3450 e.set_reason("No remaining non-daemon Java threads");
3451 e.commit();
3452 }
3453
3454 // Hang forever on exit if we are reporting an error.
3455 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
3456 os::infinite_sleep();
3457 }
3458 os::wait_for_keypress_at_exit();
3459
3460 // run Java level shutdown hooks
3461 thread->invoke_shutdown_hooks();
3462
3463 before_exit(thread);
3464
3465 thread->exit(true);
3466
3467 // We are no longer on the main thread list but could still be in a
3468 // secondary list where another thread may try to interact with us.
3469 // So wait until all such interactions are complete before we bring
3470 // the VM to the termination safepoint. Normally this would be done
3471 // using thread->smr_delete() below where we delete the thread, but
3472 // we can't call that after the termination safepoint is active as
3473 // we will deadlock on the Threads_lock. Once all interactions are
3474 // complete it is safe to directly delete the thread at any time.
3475 ThreadsSMRSupport::wait_until_not_protected(thread);
3476
3477 // Stop VM thread.
3478 {
3479 // 4945125 The vm thread comes to a safepoint during exit.
3480 // GC vm_operations can get caught at the safepoint, and the
3481 // heap is unparseable if they are caught. Grab the Heap_lock
3482 // to prevent this. The GC vm_operations will not be able to
3483 // queue until after the vm thread is dead. After this point,
3484 // we'll never emerge out of the safepoint before the VM exits.
3485 // Assert that the thread is terminated so that acquiring the
3486 // Heap_lock doesn't cause the terminated thread to participate in
3487 // the safepoint protocol.
3488
3489 assert(thread->is_terminated(), "must be terminated here");
3490 MutexLocker ml(Heap_lock);
3491
3492 VMThread::wait_for_vm_thread_exit();
3493 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3494 VMThread::destroy();
3495 }
3496
3497 // Now, all Java threads are gone except daemon threads. Daemon threads
3498 // running Java code or in VM are stopped by the Safepoint. However,
3499 // daemon threads executing native code are still running. But they
3500 // will be stopped at native=>Java/VM barriers. Note that we can't
3501 // simply kill or suspend them, as it is inherently deadlock-prone.
3502
3503 VM_Exit::set_vm_exited();
3504
3505 // Clean up ideal graph printers after the VMThread has started
3506 // the final safepoint which will block all the Compiler threads.
3507 // Note that this Thread has already logically exited so the
3508 // clean_up() function's use of a JavaThreadIteratorWithHandle
3509 // would be a problem except set_vm_exited() has remembered the
3510 // shutdown thread which is granted a policy exception.
3511 #if defined(COMPILER2) && !defined(PRODUCT)
3512 IdealGraphPrinter::clean_up();
3513 #endif
3514
3515 notify_vm_shutdown();
3516
3517 // exit_globals() will delete tty
3518 exit_globals();
3519
3520 // Deleting the shutdown thread here is safe. See comment on
3521 // wait_until_not_protected() above.
3522 delete thread;
3523
3524 #if INCLUDE_JVMCI
3525 if (JVMCICounterSize > 0) {
3526 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
3527 }
3528 #endif
3529
3530 LogConfiguration::finalize();
3531 }
3532
3533
3534 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3535 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3536 return is_supported_jni_version(version);
3537 }
3538
3539
3540 jboolean Threads::is_supported_jni_version(jint version) {
3541 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3542 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3543 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3544 if (version == JNI_VERSION_1_8) return JNI_TRUE;
3545 if (version == JNI_VERSION_9) return JNI_TRUE;
3546 if (version == JNI_VERSION_10) return JNI_TRUE;
3547 return JNI_FALSE;
3548 }
3549
3550
3551 void Threads::add(JavaThread* p, bool force_daemon) {
3552 // The threads lock must be owned at this point
3553 assert(Threads_lock->owned_by_self(), "must have threads lock");
3554
3555 BarrierSet::barrier_set()->on_thread_attach(p);
3556
3557 // Once a JavaThread is added to the Threads list, smr_delete() has
3558 // to be used to delete it. Otherwise we can just delete it directly.
3559 p->set_on_thread_list();
3560
3561 _number_of_threads++;
3562 oop threadObj = p->threadObj();
3563 bool daemon = true;
3564 // Bootstrapping problem: threadObj can be null for initial
3565 // JavaThread (or for threads attached via JNI)
3566 if ((!force_daemon) && !is_daemon((threadObj))) {
3567 _number_of_non_daemon_threads++;
3568 daemon = false;
3569 }
3570
3571 ThreadService::add_thread(p, daemon);
3572
3573 // Maintain fast thread list
3574 ThreadsSMRSupport::add_thread(p);
3575
3576 // Increase the ObjectMonitor ceiling for the new thread.
3577 ObjectSynchronizer::inc_in_use_list_ceiling();
3578
3579 // Possible GC point.
3580 Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
3581
3582 // Make new thread known to active EscapeBarrier
3583 EscapeBarrier::thread_added(p);
3584 }
3585
3586 void Threads::remove(JavaThread* p, bool is_daemon) {
3587 // Extra scope needed for Thread_lock, so we can check
3588 // that we do not remove thread without safepoint code notice
3589 { MonitorLocker ml(Threads_lock);
3590
3591 // BarrierSet state must be destroyed after the last thread transition
3592 // before the thread terminates. Thread transitions result in calls to
3593 // StackWatermarkSet::on_safepoint(), which performs GC processing,
3594 // requiring the GC state to be alive.
3595 BarrierSet::barrier_set()->on_thread_detach(p);
3596
3597 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
3598
3599 // Maintain fast thread list
3600 ThreadsSMRSupport::remove_thread(p);
3601
3602 _number_of_threads--;
3603 if (!is_daemon) {
3604 _number_of_non_daemon_threads--;
3605
3606 // Only one thread left, do a notify on the Threads_lock so a thread waiting
3607 // on destroy_vm will wake up.
3608 if (number_of_non_daemon_threads() == 1) {
3609 ml.notify_all();
3610 }
3611 }
3612 ThreadService::remove_thread(p, is_daemon);
3613
3614 // Make sure that safepoint code disregard this thread. This is needed since
3615 // the thread might mess around with locks after this point. This can cause it
3616 // to do callbacks into the safepoint code. However, the safepoint code is not aware
3617 // of this thread since it is removed from the queue.
3618 p->set_terminated(JavaThread::_thread_terminated);
3619
3620 // Notify threads waiting in EscapeBarriers
3621 EscapeBarrier::thread_removed(p);
3622 } // unlock Threads_lock
3623
3624 // Reduce the ObjectMonitor ceiling for the exiting thread.
3625 ObjectSynchronizer::dec_in_use_list_ceiling();
3626
3627 // Since Events::log uses a lock, we grab it outside the Threads_lock
3628 Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
3629 }
3630
3631 // Operations on the Threads list for GC. These are not explicitly locked,
3632 // but the garbage collector must provide a safe context for them to run.
3633 // In particular, these things should never be called when the Threads_lock
3634 // is held by some other thread. (Note: the Safepoint abstraction also
3635 // uses the Threads_lock to guarantee this property. It also makes sure that
3636 // all threads gets blocked when exiting or starting).
3637
3638 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3639 ALL_JAVA_THREADS(p) {
3640 p->oops_do(f, cf);
3641 }
3642 VMThread::vm_thread()->oops_do(f, cf);
3643 }
3644
3645 void Threads::change_thread_claim_token() {
3646 if (++_thread_claim_token == 0) {
3647 // On overflow of the token counter, there is a risk of future
3648 // collisions between a new global token value and a stale token
3649 // for a thread, because not all iterations visit all threads.
3650 // (Though it's pretty much a theoretical concern for non-trivial
3651 // token counter sizes.) To deal with the possibility, reset all
3652 // the thread tokens to zero on global token overflow.
3653 struct ResetClaims : public ThreadClosure {
3654 virtual void do_thread(Thread* t) {
3655 t->claim_threads_do(false, 0);
3656 }
3657 } reset_claims;
3658 Threads::threads_do(&reset_claims);
3659 // On overflow, update the global token to non-zero, to
3660 // avoid the special "never claimed" initial thread value.
3661 _thread_claim_token = 1;
3662 }
3663 }
3664
3665 #ifdef ASSERT
3666 void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
3667 const uintx token = t->threads_do_token();
3668 assert(token == expected,
3669 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
3670 UINTX_FORMAT, kind, p2i(t), token, expected);
3671 }
3672
3673 void Threads::assert_all_threads_claimed() {
3674 ALL_JAVA_THREADS(p) {
3675 assert_thread_claimed("Thread", p, _thread_claim_token);
3676 }
3677 assert_thread_claimed("VMThread", VMThread::vm_thread(), _thread_claim_token);
3678 }
3679 #endif // ASSERT
3680
3681 class ParallelOopsDoThreadClosure : public ThreadClosure {
3682 private:
3683 OopClosure* _f;
3684 CodeBlobClosure* _cf;
3685 public:
3686 ParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf) : _f(f), _cf(cf) {}
3687 void do_thread(Thread* t) {
3688 t->oops_do(_f, _cf);
3689 }
3690 };
3691
3692 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) {
3693 ParallelOopsDoThreadClosure tc(f, cf);
3694 possibly_parallel_threads_do(is_par, &tc);
3695 }
3696
3697 void Threads::metadata_do(MetadataClosure* f) {
3698 ALL_JAVA_THREADS(p) {
3699 p->metadata_do(f);
3700 }
3701 }
3702
3703 class ThreadHandlesClosure : public ThreadClosure {
3704 void (*_f)(Metadata*);
3705 public:
3706 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
3707 virtual void do_thread(Thread* thread) {
3708 thread->metadata_handles_do(_f);
3709 }
3710 };
3711
3712 void Threads::metadata_handles_do(void f(Metadata*)) {
3713 // Only walk the Handles in Thread.
3714 ThreadHandlesClosure handles_closure(f);
3715 threads_do(&handles_closure);
3716 }
3717
3718 // Get count Java threads that are waiting to enter the specified monitor.
3719 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
3720 int count,
3721 address monitor) {
3722 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
3723
3724 int i = 0;
3725 DO_JAVA_THREADS(t_list, p) {
3726 if (!p->can_call_java()) continue;
3727
3728 // The first stage of async deflation does not affect any field
3729 // used by this comparison so the ObjectMonitor* is usable here.
3730 address pending = (address)p->current_pending_monitor();
3731 if (pending == monitor) { // found a match
3732 if (i < count) result->append(p); // save the first count matches
3733 i++;
3734 }
3735 }
3736
3737 return result;
3738 }
3739
3740
3741 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
3742 address owner) {
3743 // NULL owner means not locked so we can skip the search
3744 if (owner == NULL) return NULL;
3745
3746 DO_JAVA_THREADS(t_list, p) {
3747 // first, see if owner is the address of a Java thread
3748 if (owner == (address)p) return p;
3749 }
3750
3751 // Cannot assert on lack of success here since this function may be
3752 // used by code that is trying to report useful problem information
3753 // like deadlock detection.
3754 if (UseHeavyMonitors) return NULL;
3755
3756 // If we didn't find a matching Java thread and we didn't force use of
3757 // heavyweight monitors, then the owner is the stack address of the
3758 // Lock Word in the owning Java thread's stack.
3759 //
3760 JavaThread* the_owner = NULL;
3761 DO_JAVA_THREADS(t_list, q) {
3762 if (q->is_lock_owned(owner)) {
3763 the_owner = q;
3764 break;
3765 }
3766 }
3767
3768 // cannot assert on lack of success here; see above comment
3769 return the_owner;
3770 }
3771
3772 class PrintOnClosure : public ThreadClosure {
3773 private:
3774 outputStream* _st;
3775
3776 public:
3777 PrintOnClosure(outputStream* st) :
3778 _st(st) {}
3779
3780 virtual void do_thread(Thread* thread) {
3781 if (thread != NULL) {
3782 thread->print_on(_st);
3783 _st->cr();
3784 }
3785 }
3786 };
3787
3788 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
3789 void Threads::print_on(outputStream* st, bool print_stacks,
3790 bool internal_format, bool print_concurrent_locks,
3791 bool print_extended_info) {
3792 char buf[32];
3793 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
3794
3795 st->print_cr("Full thread dump %s (%s %s):",
3796 VM_Version::vm_name(),
3797 VM_Version::vm_release(),
3798 VM_Version::vm_info_string());
3799 st->cr();
3800
3801 #if INCLUDE_SERVICES
3802 // Dump concurrent locks
3803 ConcurrentLocksDump concurrent_locks;
3804 if (print_concurrent_locks) {
3805 concurrent_locks.dump_at_safepoint();
3806 }
3807 #endif // INCLUDE_SERVICES
3808
3809 ThreadsSMRSupport::print_info_on(st);
3810 st->cr();
3811
3812 ALL_JAVA_THREADS(p) {
3813 ResourceMark rm;
3814 p->print_on(st, print_extended_info);
3815 if (print_stacks) {
3816 if (internal_format) {
3817 p->trace_stack();
3818 } else {
3819 p->print_stack_on(st);
3820 }
3821 }
3822 st->cr();
3823 #if INCLUDE_SERVICES
3824 if (print_concurrent_locks) {
3825 concurrent_locks.print_locks_on(p, st);
3826 }
3827 #endif // INCLUDE_SERVICES
3828 }
3829
3830 PrintOnClosure cl(st);
3831 cl.do_thread(VMThread::vm_thread());
3832 Universe::heap()->gc_threads_do(&cl);
3833 if (StringDedup::is_enabled()) {
3834 StringDedup::threads_do(&cl);
3835 }
3836 cl.do_thread(WatcherThread::watcher_thread());
3837 cl.do_thread(AsyncLogWriter::instance());
3838
3839 st->flush();
3840 }
3841
3842 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
3843 int buflen, bool* found_current) {
3844 if (this_thread != NULL) {
3845 bool is_current = (current == this_thread);
3846 *found_current = *found_current || is_current;
3847 st->print("%s", is_current ? "=>" : " ");
3848
3849 st->print(PTR_FORMAT, p2i(this_thread));
3850 st->print(" ");
3851 this_thread->print_on_error(st, buf, buflen);
3852 st->cr();
3853 }
3854 }
3855
3856 class PrintOnErrorClosure : public ThreadClosure {
3857 outputStream* _st;
3858 Thread* _current;
3859 char* _buf;
3860 int _buflen;
3861 bool* _found_current;
3862 public:
3863 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
3864 int buflen, bool* found_current) :
3865 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
3866
3867 virtual void do_thread(Thread* thread) {
3868 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
3869 }
3870 };
3871
3872 // Threads::print_on_error() is called by fatal error handler. It's possible
3873 // that VM is not at safepoint and/or current thread is inside signal handler.
3874 // Don't print stack trace, as the stack may not be walkable. Don't allocate
3875 // memory (even in resource area), it might deadlock the error handler.
3876 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
3877 int buflen) {
3878 ThreadsSMRSupport::print_info_on(st);
3879 st->cr();
3880
3881 bool found_current = false;
3882 st->print_cr("Java Threads: ( => current thread )");
3883 ALL_JAVA_THREADS(thread) {
3884 print_on_error(thread, st, current, buf, buflen, &found_current);
3885 }
3886 st->cr();
3887
3888 st->print_cr("Other Threads:");
3889 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
3890 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
3891 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
3892
3893 if (Universe::heap() != NULL) {
3894 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
3895 Universe::heap()->gc_threads_do(&print_closure);
3896 }
3897
3898 if (StringDedup::is_enabled()) {
3899 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
3900 StringDedup::threads_do(&print_closure);
3901 }
3902
3903 if (!found_current) {
3904 st->cr();
3905 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
3906 current->print_on_error(st, buf, buflen);
3907 st->cr();
3908 }
3909 st->cr();
3910
3911 st->print_cr("Threads with active compile tasks:");
3912 print_threads_compiling(st, buf, buflen);
3913 }
3914
3915 void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
3916 ALL_JAVA_THREADS(thread) {
3917 if (thread->is_Compiler_thread()) {
3918 CompilerThread* ct = (CompilerThread*) thread;
3919
3920 // Keep task in local variable for NULL check.
3921 // ct->_task might be set to NULL by concurring compiler thread
3922 // because it completed the compilation. The task is never freed,
3923 // though, just returned to a free list.
3924 CompileTask* task = ct->task();
3925 if (task != NULL) {
3926 thread->print_name_on_error(st, buf, buflen);
3927 st->print(" ");
3928 task->print(st, NULL, short_form, true);
3929 }
3930 }
3931 }
3932 }
3933
3934
3935 // Ad-hoc mutual exclusion primitives: SpinLock
3936 //
3937 // We employ SpinLocks _only for low-contention, fixed-length
3938 // short-duration critical sections where we're concerned
3939 // about native mutex_t or HotSpot Mutex:: latency.
3940 //
3941 // TODO-FIXME: ListLock should be of type SpinLock.
3942 // We should make this a 1st-class type, integrated into the lock
3943 // hierarchy as leaf-locks. Critically, the SpinLock structure
3944 // should have sufficient padding to avoid false-sharing and excessive
3945 // cache-coherency traffic.
3946
3947
3948 typedef volatile int SpinLockT;
3949
3950 void Thread::SpinAcquire(volatile int * adr, const char * LockName) {
3951 if (Atomic::cmpxchg(adr, 0, 1) == 0) {
3952 return; // normal fast-path return
3953 }
3954
3955 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
3956 int ctr = 0;
3957 int Yields = 0;
3958 for (;;) {
3959 while (*adr != 0) {
3960 ++ctr;
3961 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
3962 if (Yields > 5) {
3963 os::naked_short_sleep(1);
3964 } else {
3965 os::naked_yield();
3966 ++Yields;
3967 }
3968 } else {
3969 SpinPause();
3970 }
3971 }
3972 if (Atomic::cmpxchg(adr, 0, 1) == 0) return;
3973 }
3974 }
3975
3976 void Thread::SpinRelease(volatile int * adr) {
3977 assert(*adr != 0, "invariant");
3978 OrderAccess::fence(); // guarantee at least release consistency.
3979 // Roach-motel semantics.
3980 // It's safe if subsequent LDs and STs float "up" into the critical section,
3981 // but prior LDs and STs within the critical section can't be allowed
3982 // to reorder or float past the ST that releases the lock.
3983 // Loads and stores in the critical section - which appear in program
3984 // order before the store that releases the lock - must also appear
3985 // before the store that releases the lock in memory visibility order.
3986 // Conceptually we need a #loadstore|#storestore "release" MEMBAR before
3987 // the ST of 0 into the lock-word which releases the lock, so fence
3988 // more than covers this on all platforms.
3989 *adr = 0;
3990 }
3991
3992
3993 void Threads::verify() {
3994 ALL_JAVA_THREADS(p) {
3995 p->verify();
3996 }
3997 VMThread* thread = VMThread::vm_thread();
3998 if (thread != NULL) thread->verify();
3999 }
4000
4001 #ifndef PRODUCT
4002 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
4003 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
4004 }
4005 #endif
4006
4007 // Starts the target JavaThread as a daemon of the given priority, and
4008 // bound to the given java.lang.Thread instance.
4009 // The Threads_lock is held for the duration.
4010 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
4011 Handle thread_oop, ThreadPriority prio) {
4012
4013 assert(target->osthread()!= NULL, "target thread is not properly initialized");
4014
4015 MutexLocker mu(current, Threads_lock);
4016
4017 // Initialize the fields of the thread_oop first.
4018 if (prio != NoPriority) {
4019 java_lang_Thread::set_priority(thread_oop(), prio);
4020 // Note: we don't call os::set_priority here. Possibly we should,
4021 // else all threads should call it themselves when they first run.
4022 }
4023
4024 java_lang_Thread::set_daemon(thread_oop());
4025
4026 // Now bind the thread_oop to the target JavaThread.
4027 target->set_threadObj(thread_oop());
4028
4029 Threads::add(target); // target is now visible for safepoint/handshake
4030 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
4031 // on a ThreadsList. We don't want to wait for the release when the
4032 // Theads_lock is dropped when the 'mu' destructor is run since the
4033 // JavaThread* is already visible to JVM/TI via the ThreadsList.
4034 java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now
4035 Thread::start(target);
4036 }
4037
4038 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
4039 // At this point it may be possible that no osthread was created for the
4040 // JavaThread due to lack of resources. However, since this must work
4041 // for critical system threads just check and abort if this fails.
4042 if (thread->osthread() == nullptr) {
4043 // This isn't really an OOM condition, but historically this is what
4044 // we report.
4045 vm_exit_during_initialization("java.lang.OutOfMemoryError",
4046 os::native_thread_creation_failed_msg());
4047 }
4048 }