1 /*
2 * Copyright (c) 1997, 2022, 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/fieldDescriptor.inline.hpp"
80 #include "runtime/flags/jvmFlagLimit.hpp"
81 #include "runtime/deoptimization.hpp"
82 #include "runtime/frame.inline.hpp"
83 #include "runtime/handles.inline.hpp"
84 #include "runtime/handshake.hpp"
85 #include "runtime/init.hpp"
86 #include "runtime/interfaceSupport.inline.hpp"
87 #include "runtime/java.hpp"
88 #include "runtime/javaCalls.hpp"
89 #include "runtime/jniHandles.inline.hpp"
90 #include "runtime/jniPeriodicChecker.hpp"
91 #include "runtime/monitorDeflationThread.hpp"
92 #include "runtime/mutexLocker.hpp"
93 #include "runtime/nonJavaThread.hpp"
94 #include "runtime/objectMonitor.hpp"
95 #include "runtime/orderAccess.hpp"
96 #include "runtime/osThread.hpp"
97 #include "runtime/safepoint.hpp"
98 #include "runtime/safepointMechanism.inline.hpp"
99 #include "runtime/safepointVerifiers.hpp"
100 #include "runtime/serviceThread.hpp"
101 #include "runtime/sharedRuntime.hpp"
102 #include "runtime/stackFrameStream.inline.hpp"
103 #include "runtime/stackWatermarkSet.hpp"
104 #include "runtime/statSampler.hpp"
105 #include "runtime/task.hpp"
106 #include "runtime/thread.inline.hpp"
107 #include "runtime/threadCritical.hpp"
108 #include "runtime/threadSMR.inline.hpp"
109 #include "runtime/threadStatisticalInfo.hpp"
110 #include "runtime/threadWXSetters.inline.hpp"
111 #include "runtime/timer.hpp"
112 #include "runtime/timerTrace.hpp"
113 #include "runtime/vframe.inline.hpp"
114 #include "runtime/vframeArray.hpp"
115 #include "runtime/vframe_hp.hpp"
116 #include "runtime/vmThread.hpp"
117 #include "runtime/vmOperations.hpp"
118 #include "runtime/vm_version.hpp"
119 #include "services/attachListener.hpp"
120 #include "services/heapObjectStatistics.hpp"
121 #include "services/management.hpp"
122 #include "services/memTracker.hpp"
123 #include "services/threadService.hpp"
124 #include "utilities/align.hpp"
125 #include "utilities/copy.hpp"
126 #include "utilities/defaultStream.hpp"
127 #include "utilities/dtrace.hpp"
128 #include "utilities/events.hpp"
129 #include "utilities/macros.hpp"
130 #include "utilities/preserveException.hpp"
131 #include "utilities/spinYield.hpp"
132 #include "utilities/vmError.hpp"
133 #if INCLUDE_JVMCI
134 #include "jvmci/jvmci.hpp"
135 #include "jvmci/jvmciEnv.hpp"
136 #endif
137 #ifdef COMPILER1
138 #include "c1/c1_Compiler.hpp"
139 #endif
140 #ifdef COMPILER2
141 #include "opto/c2compiler.hpp"
142 #include "opto/idealGraphPrinter.hpp"
143 #endif
144 #if INCLUDE_RTM_OPT
145 #include "runtime/rtmLocking.hpp"
146 #endif
147 #if INCLUDE_JFR
148 #include "jfr/jfr.hpp"
149 #endif
150
151 // Initialization after module runtime initialization
152 void universe_post_module_init(); // must happen after call_initPhase2
153
154 #ifdef DTRACE_ENABLED
155
156 // Only bother with this argument setup if dtrace is available
157
158 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
159 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
160
161 #define DTRACE_THREAD_PROBE(probe, javathread) \
162 { \
163 ResourceMark rm(this); \
164 int len = 0; \
165 const char* name = (javathread)->name(); \
166 len = strlen(name); \
167 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
168 (char *) name, len, \
169 java_lang_Thread::thread_id((javathread)->threadObj()), \
170 (uintptr_t) (javathread)->osthread()->thread_id(), \
171 java_lang_Thread::is_daemon((javathread)->threadObj())); \
172 }
173
174 #else // ndef DTRACE_ENABLED
175
176 #define DTRACE_THREAD_PROBE(probe, javathread)
177
178 #endif // ndef DTRACE_ENABLED
179
180 #ifndef USE_LIBRARY_BASED_TLS_ONLY
181 // Current thread is maintained as a thread-local variable
182 THREAD_LOCAL Thread* Thread::_thr_current = NULL;
183 #endif
184
185 // ======= Thread ========
186 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
187 return throw_excpt ? AllocateHeap(size, flags, CURRENT_PC)
188 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
189 }
190
191 void Thread::operator delete(void* p) {
192 FreeHeap(p);
193 }
194
195 void JavaThread::smr_delete() {
196 if (_on_thread_list) {
197 ThreadsSMRSupport::smr_delete(this);
198 } else {
199 delete this;
200 }
201 }
202
203 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
204 // JavaThread
205
206 DEBUG_ONLY(Thread* Thread::_starting_thread = NULL;)
207
208 Thread::Thread() {
209
210 DEBUG_ONLY(_run_state = PRE_CALL_RUN;)
211
212 // stack and get_thread
213 set_stack_base(NULL);
214 set_stack_size(0);
215 set_lgrp_id(-1);
216 DEBUG_ONLY(clear_suspendible_thread();)
217
218 // allocated data structures
219 set_osthread(NULL);
220 set_resource_area(new (mtThread)ResourceArea());
221 DEBUG_ONLY(_current_resource_mark = NULL;)
222 set_handle_area(new (mtThread) HandleArea(NULL));
223 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, mtClass));
224 set_last_handle_mark(NULL);
225 DEBUG_ONLY(_missed_ic_stub_refill_verifier = NULL);
226
227 // Initial value of zero ==> never claimed.
228 _threads_do_token = 0;
229 _threads_hazard_ptr = NULL;
230 _threads_list_ptr = NULL;
231 _nested_threads_hazard_ptr_cnt = 0;
232 _rcu_counter = 0;
233
234 // the handle mark links itself to last_handle_mark
235 new HandleMark(this);
236
237 // plain initialization
238 debug_only(_owned_locks = NULL;)
239 NOT_PRODUCT(_skip_gcalot = false;)
240 _jvmti_env_iteration_count = 0;
241 set_allocated_bytes(0);
242 _current_pending_raw_monitor = NULL;
243
244 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
245 _hashStateX = os::random();
246 _hashStateY = 842502087;
247 _hashStateZ = 0x8767; // (int)(3579807591LL & 0xffff) ;
248 _hashStateW = 273326509;
249
250 // Many of the following fields are effectively final - immutable
251 // Note that nascent threads can't use the Native Monitor-Mutex
252 // construct until the _MutexEvent is initialized ...
253 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
254 // we might instead use a stack of ParkEvents that we could provision on-demand.
255 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
256 // and ::Release()
257 _ParkEvent = ParkEvent::Allocate(this);
258
259 #ifdef CHECK_UNHANDLED_OOPS
260 if (CheckUnhandledOops) {
261 _unhandled_oops = new UnhandledOops(this);
262 }
263 #endif // CHECK_UNHANDLED_OOPS
264
265 // Notify the barrier set that a thread is being created. The initial
266 // thread is created before the barrier set is available. The call to
267 // BarrierSet::on_thread_create() for this thread is therefore deferred
268 // to BarrierSet::set_barrier_set().
269 BarrierSet* const barrier_set = BarrierSet::barrier_set();
270 if (barrier_set != NULL) {
271 barrier_set->on_thread_create(this);
272 } else {
273 // Only the main thread should be created before the barrier set
274 // and that happens just before Thread::current is set. No other thread
275 // can attach as the VM is not created yet, so they can't execute this code.
276 // If the main thread creates other threads before the barrier set that is an error.
277 assert(Thread::current_or_null() == NULL, "creating thread before barrier set");
278 }
279
280 MACOS_AARCH64_ONLY(DEBUG_ONLY(_wx_init = false));
281 }
282
283 void Thread::initialize_tlab() {
284 if (UseTLAB) {
285 tlab().initialize();
286 }
287 }
288
289 void Thread::initialize_thread_current() {
290 #ifndef USE_LIBRARY_BASED_TLS_ONLY
291 assert(_thr_current == NULL, "Thread::current already initialized");
292 _thr_current = this;
293 #endif
294 assert(ThreadLocalStorage::thread() == NULL, "ThreadLocalStorage::thread already initialized");
295 ThreadLocalStorage::set_thread(this);
296 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
297 }
298
299 void Thread::clear_thread_current() {
300 assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
301 #ifndef USE_LIBRARY_BASED_TLS_ONLY
302 _thr_current = NULL;
303 #endif
304 ThreadLocalStorage::set_thread(NULL);
305 }
306
307 void Thread::record_stack_base_and_size() {
308 // Note: at this point, Thread object is not yet initialized. Do not rely on
309 // any members being initialized. Do not rely on Thread::current() being set.
310 // If possible, refrain from doing anything which may crash or assert since
311 // quite probably those crash dumps will be useless.
312 set_stack_base(os::current_stack_base());
313 set_stack_size(os::current_stack_size());
314
315 // Set stack limits after thread is initialized.
316 if (is_Java_thread()) {
317 JavaThread::cast(this)->stack_overflow_state()->initialize(stack_base(), stack_end());
318 }
319 }
320
321 void Thread::register_thread_stack_with_NMT() {
322 MemTracker::record_thread_stack(stack_end(), stack_size());
323 }
324
325 void Thread::unregister_thread_stack_with_NMT() {
326 MemTracker::release_thread_stack(stack_end(), stack_size());
327 }
328
329 void Thread::call_run() {
330 DEBUG_ONLY(_run_state = CALL_RUN;)
331
332 // At this point, Thread object should be fully initialized and
333 // Thread::current() should be set.
334
335 assert(Thread::current_or_null() != NULL, "current thread is unset");
336 assert(Thread::current_or_null() == this, "current thread is wrong");
337
338 // Perform common initialization actions
339
340 MACOS_AARCH64_ONLY(this->init_wx());
341
342 register_thread_stack_with_NMT();
343
344 JFR_ONLY(Jfr::on_thread_start(this);)
345
346 log_debug(os, thread)("Thread " UINTX_FORMAT " stack dimensions: "
347 PTR_FORMAT "-" PTR_FORMAT " (" SIZE_FORMAT "k).",
348 os::current_thread_id(), p2i(stack_end()),
349 p2i(stack_base()), stack_size()/1024);
350
351 // Perform <ChildClass> initialization actions
352 DEBUG_ONLY(_run_state = PRE_RUN;)
353 this->pre_run();
354
355 // Invoke <ChildClass>::run()
356 DEBUG_ONLY(_run_state = RUN;)
357 this->run();
358 // Returned from <ChildClass>::run(). Thread finished.
359
360 // Perform common tear-down actions
361
362 assert(Thread::current_or_null() != NULL, "current thread is unset");
363 assert(Thread::current_or_null() == this, "current thread is wrong");
364
365 // Perform <ChildClass> tear-down actions
366 DEBUG_ONLY(_run_state = POST_RUN;)
367 this->post_run();
368
369 // Note: at this point the thread object may already have deleted itself,
370 // so from here on do not dereference *this*. Not all thread types currently
371 // delete themselves when they terminate. But no thread should ever be deleted
372 // asynchronously with respect to its termination - that is what _run_state can
373 // be used to check.
374
375 assert(Thread::current_or_null() == NULL, "current thread still present");
376 }
377
378 Thread::~Thread() {
379
380 // Attached threads will remain in PRE_CALL_RUN, as will threads that don't actually
381 // get started due to errors etc. Any active thread should at least reach post_run
382 // before it is deleted (usually in post_run()).
383 assert(_run_state == PRE_CALL_RUN ||
384 _run_state == POST_RUN, "Active Thread deleted before post_run(): "
385 "_run_state=%d", (int)_run_state);
386
387 // Notify the barrier set that a thread is being destroyed. Note that a barrier
388 // set might not be available if we encountered errors during bootstrapping.
389 BarrierSet* const barrier_set = BarrierSet::barrier_set();
390 if (barrier_set != NULL) {
391 barrier_set->on_thread_destroy(this);
392 }
393
394 // deallocate data structures
395 delete resource_area();
396 // since the handle marks are using the handle area, we have to deallocated the root
397 // handle mark before deallocating the thread's handle area,
398 assert(last_handle_mark() != NULL, "check we have an element");
399 delete last_handle_mark();
400 assert(last_handle_mark() == NULL, "check we have reached the end");
401
402 ParkEvent::Release(_ParkEvent);
403 // Set to NULL as a termination indicator for has_terminated().
404 Atomic::store(&_ParkEvent, (ParkEvent*)NULL);
405
406 delete handle_area();
407 delete metadata_handles();
408
409 // osthread() can be NULL, if creation of thread failed.
410 if (osthread() != NULL) os::free_thread(osthread());
411
412 // Clear Thread::current if thread is deleting itself and it has not
413 // already been done. This must be done before the memory is deallocated.
414 // Needed to ensure JNI correctly detects non-attached threads.
415 if (this == Thread::current_or_null()) {
416 Thread::clear_thread_current();
417 }
418
419 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
420 }
421
422 #ifdef ASSERT
423 // A JavaThread is considered dangling if it not handshake-safe with respect to
424 // the current thread, it is not on a ThreadsList, or not at safepoint.
425 void Thread::check_for_dangling_thread_pointer(Thread *thread) {
426 assert(!thread->is_Java_thread() ||
427 JavaThread::cast(thread)->is_handshake_safe_for(Thread::current()) ||
428 !JavaThread::cast(thread)->on_thread_list() ||
429 SafepointSynchronize::is_at_safepoint() ||
430 ThreadsSMRSupport::is_a_protected_JavaThread_with_lock(JavaThread::cast(thread)),
431 "possibility of dangling Thread pointer");
432 }
433 #endif
434
435 // Is the target JavaThread protected by the calling Thread or by some other
436 // mechanism?
437 //
438 bool Thread::is_JavaThread_protected(const JavaThread* target) {
439 Thread* current_thread = Thread::current();
440
441 // Do the simplest check first:
442 if (SafepointSynchronize::is_at_safepoint()) {
443 // The target is protected since JavaThreads cannot exit
444 // while we're at a safepoint.
445 return true;
446 }
447
448 // If the target hasn't been started yet then it is trivially
449 // "protected". We assume the caller is the thread that will do
450 // the starting.
451 if (target->osthread() == NULL || target->osthread()->get_state() <= INITIALIZED) {
452 return true;
453 }
454
455 // Now make the simple checks based on who the caller is:
456 if (current_thread == target || Threads_lock->owner() == current_thread) {
457 // Target JavaThread is self or calling thread owns the Threads_lock.
458 // Second check is the same as Threads_lock->owner_is_self(),
459 // but we already have the current thread so check directly.
460 return true;
461 }
462
463 // Check the ThreadsLists associated with the calling thread (if any)
464 // to see if one of them protects the target JavaThread:
465 if (is_JavaThread_protected_by_TLH(target)) {
466 return true;
467 }
468
469 // Use this debug code with -XX:+UseNewCode to diagnose locations that
470 // are missing a ThreadsListHandle or other protection mechanism:
471 // guarantee(!UseNewCode, "current_thread=" INTPTR_FORMAT " is not protecting target="
472 // INTPTR_FORMAT, p2i(current_thread), p2i(target));
473
474 // Note: Since 'target' isn't protected by a TLH, the call to
475 // target->is_handshake_safe_for() may crash, but we have debug bits so
476 // we'll be able to figure out what protection mechanism is missing.
477 assert(target->is_handshake_safe_for(current_thread), "JavaThread=" INTPTR_FORMAT
478 " is not protected and not handshake safe.", p2i(target));
479
480 // The target JavaThread is not protected so it is not safe to query:
481 return false;
482 }
483
484 // Is the target JavaThread protected by a ThreadsListHandle (TLH) associated
485 // with the calling Thread?
486 //
487 bool Thread::is_JavaThread_protected_by_TLH(const JavaThread* target) {
488 Thread* current_thread = Thread::current();
489
490 // Check the ThreadsLists associated with the calling thread (if any)
491 // to see if one of them protects the target JavaThread:
492 for (SafeThreadsListPtr* stlp = current_thread->_threads_list_ptr;
493 stlp != NULL; stlp = stlp->previous()) {
494 if (stlp->list()->includes(target)) {
495 // The target JavaThread is protected by this ThreadsList:
496 return true;
497 }
498 }
499
500 // The target JavaThread is not protected by a TLH so it is not safe to query:
501 return false;
502 }
503
504 ThreadPriority Thread::get_priority(const Thread* const thread) {
505 ThreadPriority priority;
506 // Can return an error!
507 (void)os::get_priority(thread, priority);
508 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
509 return priority;
510 }
511
512 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
513 debug_only(check_for_dangling_thread_pointer(thread);)
514 // Can return an error!
515 (void)os::set_priority(thread, priority);
516 }
517
518
519 void Thread::start(Thread* thread) {
520 // Start is different from resume in that its safety is guaranteed by context or
521 // being called from a Java method synchronized on the Thread object.
522 if (thread->is_Java_thread()) {
523 // Initialize the thread state to RUNNABLE before starting this thread.
524 // Can not set it after the thread started because we do not know the
525 // exact thread state at that time. It could be in MONITOR_WAIT or
526 // in SLEEPING or some other state.
527 java_lang_Thread::set_thread_status(JavaThread::cast(thread)->threadObj(),
528 JavaThreadStatus::RUNNABLE);
529 }
530 os::start_thread(thread);
531 }
532
533 // GC Support
534 bool Thread::claim_par_threads_do(uintx claim_token) {
535 uintx token = _threads_do_token;
536 if (token != claim_token) {
537 uintx res = Atomic::cmpxchg(&_threads_do_token, token, claim_token);
538 if (res == token) {
539 return true;
540 }
541 guarantee(res == claim_token, "invariant");
542 }
543 return false;
544 }
545
546 void Thread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
547 // Do oop for ThreadShadow
548 f->do_oop((oop*)&_pending_exception);
549 handle_area()->oops_do(f);
550 }
551
552 // If the caller is a NamedThread, then remember, in the current scope,
553 // the given JavaThread in its _processed_thread field.
554 class RememberProcessedThread: public StackObj {
555 NamedThread* _cur_thr;
556 public:
557 RememberProcessedThread(Thread* thread) {
558 Thread* self = Thread::current();
559 if (self->is_Named_thread()) {
560 _cur_thr = (NamedThread *)self;
561 assert(_cur_thr->processed_thread() == NULL, "nesting not supported");
562 _cur_thr->set_processed_thread(thread);
563 } else {
564 _cur_thr = NULL;
565 }
566 }
567
568 ~RememberProcessedThread() {
569 if (_cur_thr) {
570 assert(_cur_thr->processed_thread() != NULL, "nesting not supported");
571 _cur_thr->set_processed_thread(NULL);
572 }
573 }
574 };
575
576 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
577 // Record JavaThread to GC thread
578 RememberProcessedThread rpt(this);
579 oops_do_no_frames(f, cf);
580 oops_do_frames(f, cf);
581 }
582
583 void Thread::metadata_handles_do(void f(Metadata*)) {
584 // Only walk the Handles in Thread.
585 if (metadata_handles() != NULL) {
586 for (int i = 0; i< metadata_handles()->length(); i++) {
587 f(metadata_handles()->at(i));
588 }
589 }
590 }
591
592 void Thread::print_on(outputStream* st, bool print_extended_info) const {
593 // get_priority assumes osthread initialized
594 if (osthread() != NULL) {
595 int os_prio;
596 if (os::get_native_priority(this, &os_prio) == OS_OK) {
597 st->print("os_prio=%d ", os_prio);
598 }
599
600 st->print("cpu=%.2fms ",
601 os::thread_cpu_time(const_cast<Thread*>(this), true) / 1000000.0
602 );
603 st->print("elapsed=%.2fs ",
604 _statistical_info.getElapsedTime() / 1000.0
605 );
606 if (is_Java_thread() && (PrintExtendedThreadInfo || print_extended_info)) {
607 size_t allocated_bytes = (size_t) const_cast<Thread*>(this)->cooked_allocated_bytes();
608 st->print("allocated=" SIZE_FORMAT "%s ",
609 byte_size_in_proper_unit(allocated_bytes),
610 proper_unit_for_byte_size(allocated_bytes)
611 );
612 st->print("defined_classes=" INT64_FORMAT " ", _statistical_info.getDefineClassCount());
613 }
614
615 st->print("tid=" INTPTR_FORMAT " ", p2i(this));
616 osthread()->print_on(st);
617 }
618 ThreadsSMRSupport::print_info_on(this, st);
619 st->print(" ");
620 debug_only(if (WizardMode) print_owned_locks_on(st);)
621 }
622
623 void Thread::print() const { print_on(tty); }
624
625 // Thread::print_on_error() is called by fatal error handler. Don't use
626 // any lock or allocate memory.
627 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
628 assert(!(is_Compiler_thread() || is_Java_thread()), "Can't call name() here if it allocates");
629
630 st->print("%s \"%s\"", type_name(), name());
631
632 OSThread* os_thr = osthread();
633 if (os_thr != NULL) {
634 if (os_thr->get_state() != ZOMBIE) {
635 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
636 p2i(stack_end()), p2i(stack_base()));
637 st->print(" [id=%d]", osthread()->thread_id());
638 } else {
639 st->print(" terminated");
640 }
641 } else {
642 st->print(" unknown state (no osThread)");
643 }
644 ThreadsSMRSupport::print_info_on(this, st);
645 }
646
647 void Thread::print_value_on(outputStream* st) const {
648 if (is_Named_thread()) {
649 st->print(" \"%s\" ", name());
650 }
651 st->print(INTPTR_FORMAT, p2i(this)); // print address
652 }
653
654 #ifdef ASSERT
655 void Thread::print_owned_locks_on(outputStream* st) const {
656 Mutex* cur = _owned_locks;
657 if (cur == NULL) {
658 st->print(" (no locks) ");
659 } else {
660 st->print_cr(" Locks owned:");
661 while (cur) {
662 cur->print_on(st);
663 cur = cur->next();
664 }
665 }
666 }
667 #endif // ASSERT
668
669 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
670 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
671 // used for compilation in the future. If that change is made, the need for these methods
672 // should be revisited, and they should be removed if possible.
673
674 bool Thread::is_lock_owned(address adr) const {
675 return is_in_full_stack(adr);
676 }
677
678 bool Thread::set_as_starting_thread() {
679 assert(_starting_thread == NULL, "already initialized: "
680 "_starting_thread=" INTPTR_FORMAT, p2i(_starting_thread));
681 // NOTE: this must be called inside the main thread.
682 DEBUG_ONLY(_starting_thread = this;)
683 return os::create_main_thread(JavaThread::cast(this));
684 }
685
686 static void initialize_class(Symbol* class_name, TRAPS) {
687 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
688 InstanceKlass::cast(klass)->initialize(CHECK);
689 }
690
691
692 // Creates the initial ThreadGroup
693 static Handle create_initial_thread_group(TRAPS) {
694 Handle system_instance = JavaCalls::construct_new_instance(
695 vmClasses::ThreadGroup_klass(),
696 vmSymbols::void_method_signature(),
697 CHECK_NH);
698 Universe::set_system_thread_group(system_instance());
699
700 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
701 Handle main_instance = JavaCalls::construct_new_instance(
702 vmClasses::ThreadGroup_klass(),
703 vmSymbols::threadgroup_string_void_signature(),
704 system_instance,
705 string,
706 CHECK_NH);
707 return main_instance;
708 }
709
710 // Creates the initial Thread, and sets it to running.
711 static void create_initial_thread(Handle thread_group, JavaThread* thread,
712 TRAPS) {
713 InstanceKlass* ik = vmClasses::Thread_klass();
714 assert(ik->is_initialized(), "must be");
715 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
716
717 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
718 // constructor calls Thread.current(), which must be set here for the
719 // initial thread.
720 java_lang_Thread::set_thread(thread_oop(), thread);
721 java_lang_Thread::set_priority(thread_oop(), NormPriority);
722 thread->set_threadObj(thread_oop());
723
724 Handle string = java_lang_String::create_from_str("main", CHECK);
725
726 JavaValue result(T_VOID);
727 JavaCalls::call_special(&result, thread_oop,
728 ik,
729 vmSymbols::object_initializer_name(),
730 vmSymbols::threadgroup_string_void_signature(),
731 thread_group,
732 string,
733 CHECK);
734
735 // Set thread status to running since main thread has
736 // been started and running.
737 java_lang_Thread::set_thread_status(thread_oop(),
738 JavaThreadStatus::RUNNABLE);
739 }
740
741 // Extract version and vendor specific information from
742 // java.lang.VersionProps fields.
743 // Returned char* is allocated in the thread's resource area
744 // so must be copied for permanency.
745 static const char* get_java_version_info(InstanceKlass* ik,
746 Symbol* field_name) {
747 fieldDescriptor fd;
748 bool found = ik != NULL &&
749 ik->find_local_field(field_name,
750 vmSymbols::string_signature(), &fd);
751 if (found) {
752 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
753 if (name_oop == NULL) {
754 return NULL;
755 }
756 const char* name = java_lang_String::as_utf8_string(name_oop);
757 return name;
758 } else {
759 return NULL;
760 }
761 }
762
763 // General purpose hook into Java code, run once when the VM is initialized.
764 // The Java library method itself may be changed independently from the VM.
765 static void call_postVMInitHook(TRAPS) {
766 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
767 if (klass != NULL) {
768 JavaValue result(T_VOID);
769 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
770 vmSymbols::void_method_signature(),
771 CHECK);
772 }
773 }
774
775 // Initialized by VMThread at vm_global_init
776 static OopStorage* _thread_oop_storage = NULL;
777
778 oop JavaThread::threadObj() const {
779 return _threadObj.resolve();
780 }
781
782 void JavaThread::set_threadObj(oop p) {
783 assert(_thread_oop_storage != NULL, "not yet initialized");
784 _threadObj = OopHandle(_thread_oop_storage, p);
785 }
786
787 OopStorage* JavaThread::thread_oop_storage() {
788 assert(_thread_oop_storage != NULL, "not yet initialized");
789 return _thread_oop_storage;
790 }
791
792 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
793 bool daemon, TRAPS) {
794 assert(thread_group.not_null(), "thread group should be specified");
795 assert(threadObj() == NULL, "should only create Java thread object once");
796
797 InstanceKlass* ik = vmClasses::Thread_klass();
798 assert(ik->is_initialized(), "must be");
799 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
800
801 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
802 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
803 // constructor calls Thread.current(), which must be set here.
804 java_lang_Thread::set_thread(thread_oop(), this);
805 java_lang_Thread::set_priority(thread_oop(), NormPriority);
806 set_threadObj(thread_oop());
807
808 JavaValue result(T_VOID);
809 if (thread_name != NULL) {
810 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
811 // Thread gets assigned specified name and null target
812 JavaCalls::call_special(&result,
813 thread_oop,
814 ik,
815 vmSymbols::object_initializer_name(),
816 vmSymbols::threadgroup_string_void_signature(),
817 thread_group,
818 name,
819 THREAD);
820 } else {
821 // Thread gets assigned name "Thread-nnn" and null target
822 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
823 JavaCalls::call_special(&result,
824 thread_oop,
825 ik,
826 vmSymbols::object_initializer_name(),
827 vmSymbols::threadgroup_runnable_void_signature(),
828 thread_group,
829 Handle(),
830 THREAD);
831 }
832
833
834 if (daemon) {
835 java_lang_Thread::set_daemon(thread_oop());
836 }
837
838 if (HAS_PENDING_EXCEPTION) {
839 return;
840 }
841
842 Klass* group = vmClasses::ThreadGroup_klass();
843 Handle threadObj(THREAD, this->threadObj());
844
845 JavaCalls::call_special(&result,
846 thread_group,
847 group,
848 vmSymbols::add_method_name(),
849 vmSymbols::thread_void_signature(),
850 threadObj, // Arg 1
851 THREAD);
852 }
853
854 // ======= JavaThread ========
855
856 #if INCLUDE_JVMCI
857
858 jlong* JavaThread::_jvmci_old_thread_counters;
859
860 bool jvmci_counters_include(JavaThread* thread) {
861 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
862 }
863
864 void JavaThread::collect_counters(jlong* array, int length) {
865 assert(length == JVMCICounterSize, "wrong value");
866 for (int i = 0; i < length; i++) {
867 array[i] = _jvmci_old_thread_counters[i];
868 }
869 for (JavaThread* tp : ThreadsListHandle()) {
870 if (jvmci_counters_include(tp)) {
871 for (int i = 0; i < length; i++) {
872 array[i] += tp->_jvmci_counters[i];
873 }
874 }
875 }
876 }
877
878 // Attempt to enlarge the array for per thread counters.
879 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
880 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
881 if (new_counters == NULL) {
882 return NULL;
883 }
884 if (old_counters == NULL) {
885 old_counters = new_counters;
886 memset(old_counters, 0, sizeof(jlong) * new_size);
887 } else {
888 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
889 new_counters[i] = old_counters[i];
890 }
891 if (new_size > current_size) {
892 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
893 }
894 FREE_C_HEAP_ARRAY(jlong, old_counters);
895 }
896 return new_counters;
897 }
898
899 // Attempt to enlarge the array for per thread counters.
900 bool JavaThread::resize_counters(int current_size, int new_size) {
901 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
902 if (new_counters == NULL) {
903 return false;
904 } else {
905 _jvmci_counters = new_counters;
906 return true;
907 }
908 }
909
910 class VM_JVMCIResizeCounters : public VM_Operation {
911 private:
912 int _new_size;
913 bool _failed;
914
915 public:
916 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
917 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
918 bool allow_nested_vm_operations() const { return true; }
919 void doit() {
920 // Resize the old thread counters array
921 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
922 if (new_counters == NULL) {
923 _failed = true;
924 return;
925 } else {
926 JavaThread::_jvmci_old_thread_counters = new_counters;
927 }
928
929 // Now resize each threads array
930 for (JavaThread* tp : ThreadsListHandle()) {
931 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
932 _failed = true;
933 break;
934 }
935 }
936 if (!_failed) {
937 JVMCICounterSize = _new_size;
938 }
939 }
940
941 bool failed() { return _failed; }
942 };
943
944 bool JavaThread::resize_all_jvmci_counters(int new_size) {
945 VM_JVMCIResizeCounters op(new_size);
946 VMThread::execute(&op);
947 return !op.failed();
948 }
949
950 #endif // INCLUDE_JVMCI
951
952 #ifdef ASSERT
953 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
954 void JavaThread::check_possible_safepoint() {
955 if (_no_safepoint_count > 0) {
956 print_owned_locks();
957 assert(false, "Possible safepoint reached by thread that does not allow it");
958 }
959 #ifdef CHECK_UNHANDLED_OOPS
960 // Clear unhandled oops in JavaThreads so we get a crash right away.
961 clear_unhandled_oops();
962 #endif // CHECK_UNHANDLED_OOPS
963
964 // Macos/aarch64 should be in the right state for safepoint (e.g.
965 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely
966 // happens in practice, making such issues hard to find and reproduce.
967 #if defined(__APPLE__) && defined(AARCH64)
968 if (AssertWXAtThreadSync) {
969 assert_wx_state(WXWrite);
970 }
971 #endif
972 }
973
974 void JavaThread::check_for_valid_safepoint_state() {
975 // Check NoSafepointVerifier, which is implied by locks taken that can be
976 // shared with the VM thread. This makes sure that no locks with allow_vm_block
977 // are held.
978 check_possible_safepoint();
979
980 if (thread_state() != _thread_in_vm) {
981 fatal("LEAF method calling lock?");
982 }
983
984 if (GCALotAtAllSafepoints) {
985 // We could enter a safepoint here and thus have a gc
986 InterfaceSupport::check_gc_alot();
987 }
988 }
989 #endif // ASSERT
990
991 // A JavaThread is a normal Java thread
992
993 JavaThread::JavaThread() :
994 // Initialize fields
995
996 _on_thread_list(false),
997 DEBUG_ONLY(_java_call_counter(0) COMMA)
998 _entry_point(nullptr),
999 _deopt_mark(nullptr),
1000 _deopt_nmethod(nullptr),
1001 _vframe_array_head(nullptr),
1002 _vframe_array_last(nullptr),
1003 _jvmti_deferred_updates(nullptr),
1004 _callee_target(nullptr),
1005 _vm_result(nullptr),
1006 _vm_result_2(nullptr),
1007
1008 _current_pending_monitor(NULL),
1009 _current_pending_monitor_is_from_java(true),
1010 _current_waiting_monitor(NULL),
1011 _active_handles(NULL),
1012 _free_handle_block(NULL),
1013 _Stalled(0),
1014
1015 _monitor_chunks(nullptr),
1016
1017 _suspend_flags(0),
1018
1019 _thread_state(_thread_new),
1020 _saved_exception_pc(nullptr),
1021 #ifdef ASSERT
1022 _no_safepoint_count(0),
1023 _visited_for_critical_count(false),
1024 #endif
1025
1026 _terminated(_not_terminated),
1027 _in_deopt_handler(0),
1028 _doing_unsafe_access(false),
1029 _do_not_unlock_if_synchronized(false),
1030 _jni_attach_state(_not_attaching_via_jni),
1031 #if INCLUDE_JVMCI
1032 _pending_deoptimization(-1),
1033 _pending_monitorenter(false),
1034 _pending_transfer_to_interpreter(false),
1035 _in_retryable_allocation(false),
1036 _pending_failed_speculation(0),
1037 _jvmci{nullptr},
1038 _libjvmci_runtime(nullptr),
1039 _jvmci_counters(nullptr),
1040 _jvmci_reserved0(0),
1041 _jvmci_reserved1(0),
1042 _jvmci_reserved_oop0(nullptr),
1043 #endif // INCLUDE_JVMCI
1044
1045 _exception_oop(oop()),
1046 _exception_pc(0),
1047 _exception_handler_pc(0),
1048 _is_method_handle_return(0),
1049
1050 _jni_active_critical(0),
1051 _pending_jni_exception_check_fn(nullptr),
1052 _depth_first_number(0),
1053
1054 // JVMTI PopFrame support
1055 _popframe_condition(popframe_inactive),
1056 _frames_to_pop_failed_realloc(0),
1057
1058 _handshake(this),
1059
1060 _popframe_preserved_args(nullptr),
1061 _popframe_preserved_args_size(0),
1062
1063 _jvmti_thread_state(nullptr),
1064 _interp_only_mode(0),
1065 _should_post_on_exceptions_flag(JNI_FALSE),
1066 _thread_stat(new ThreadStatistics()),
1067
1068 _parker(),
1069
1070 _class_to_be_initialized(nullptr),
1071
1072 _SleepEvent(ParkEvent::Allocate(this))
1073 {
1074 set_jni_functions(jni_functions());
1075
1076 #if INCLUDE_JVMCI
1077 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
1078 if (JVMCICounterSize > 0) {
1079 resize_counters(0, (int) JVMCICounterSize);
1080 }
1081 #endif // INCLUDE_JVMCI
1082
1083 // Setup safepoint state info for this thread
1084 ThreadSafepointState::create(this);
1085
1086 SafepointMechanism::initialize_header(this);
1087
1088 set_requires_cross_modify_fence(false);
1089
1090 pd_initialize();
1091 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
1092 }
1093
1094 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
1095 if (is_attaching_via_jni) {
1096 _jni_attach_state = _attaching_via_jni;
1097 }
1098 }
1099
1100
1101 // interrupt support
1102
1103 void JavaThread::interrupt() {
1104 // All callers should have 'this' thread protected by a
1105 // ThreadsListHandle so that it cannot terminate and deallocate
1106 // itself.
1107 debug_only(check_for_dangling_thread_pointer(this);)
1108
1109 // For Windows _interrupt_event
1110 WINDOWS_ONLY(osthread()->set_interrupted(true);)
1111
1112 // For Thread.sleep
1113 _SleepEvent->unpark();
1114
1115 // For JSR166 LockSupport.park
1116 parker()->unpark();
1117
1118 // For ObjectMonitor and JvmtiRawMonitor
1119 _ParkEvent->unpark();
1120 }
1121
1122
1123 bool JavaThread::is_interrupted(bool clear_interrupted) {
1124 debug_only(check_for_dangling_thread_pointer(this);)
1125
1126 if (_threadObj.peek() == NULL) {
1127 // If there is no j.l.Thread then it is impossible to have
1128 // been interrupted. We can find NULL during VM initialization
1129 // or when a JNI thread is still in the process of attaching.
1130 // In such cases this must be the current thread.
1131 assert(this == Thread::current(), "invariant");
1132 return false;
1133 }
1134
1135 bool interrupted = java_lang_Thread::interrupted(threadObj());
1136
1137 // NOTE that since there is no "lock" around the interrupt and
1138 // is_interrupted operations, there is the possibility that the
1139 // interrupted flag will be "false" but that the
1140 // low-level events will be in the signaled state. This is
1141 // intentional. The effect of this is that Object.wait() and
1142 // LockSupport.park() will appear to have a spurious wakeup, which
1143 // is allowed and not harmful, and the possibility is so rare that
1144 // it is not worth the added complexity to add yet another lock.
1145 // For the sleep event an explicit reset is performed on entry
1146 // to JavaThread::sleep, so there is no early return. It has also been
1147 // recommended not to put the interrupted flag into the "event"
1148 // structure because it hides the issue.
1149 // Also, because there is no lock, we must only clear the interrupt
1150 // state if we are going to report that we were interrupted; otherwise
1151 // an interrupt that happens just after we read the field would be lost.
1152 if (interrupted && clear_interrupted) {
1153 assert(this == Thread::current(), "only the current thread can clear");
1154 java_lang_Thread::set_interrupted(threadObj(), false);
1155 WINDOWS_ONLY(osthread()->set_interrupted(false);)
1156 }
1157
1158 return interrupted;
1159 }
1160
1161 void JavaThread::block_if_vm_exited() {
1162 if (_terminated == _vm_exited) {
1163 // _vm_exited is set at safepoint, and Threads_lock is never released
1164 // we will block here forever.
1165 // Here we can be doing a jump from a safe state to an unsafe state without
1166 // proper transition, but it happens after the final safepoint has begun.
1167 set_thread_state(_thread_in_vm);
1168 Threads_lock->lock();
1169 ShouldNotReachHere();
1170 }
1171 }
1172
1173 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
1174 _jni_attach_state = _not_attaching_via_jni;
1175 set_entry_point(entry_point);
1176 // Create the native thread itself.
1177 // %note runtime_23
1178 os::ThreadType thr_type = os::java_thread;
1179 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
1180 os::java_thread;
1181 os::create_thread(this, thr_type, stack_sz);
1182 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1183 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1184 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1185 // the exception consists of creating the exception object & initializing it, initialization
1186 // will leave the VM via a JavaCall and then all locks must be unlocked).
1187 //
1188 // The thread is still suspended when we reach here. Thread must be explicit started
1189 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1190 // by calling Threads:add. The reason why this is not done here, is because the thread
1191 // object must be fully initialized (take a look at JVM_Start)
1192 }
1193
1194 JavaThread::~JavaThread() {
1195
1196 // Ask ServiceThread to release the threadObj OopHandle
1197 ServiceThread::add_oop_handle_release(_threadObj);
1198
1199 // Return the sleep event to the free list
1200 ParkEvent::Release(_SleepEvent);
1201 _SleepEvent = NULL;
1202
1203 // Free any remaining previous UnrollBlock
1204 vframeArray* old_array = vframe_array_last();
1205
1206 if (old_array != NULL) {
1207 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1208 old_array->set_unroll_block(NULL);
1209 delete old_info;
1210 delete old_array;
1211 }
1212
1213 JvmtiDeferredUpdates* updates = deferred_updates();
1214 if (updates != NULL) {
1215 // This can only happen if thread is destroyed before deoptimization occurs.
1216 assert(updates->count() > 0, "Updates holder not deleted");
1217 // free deferred updates.
1218 delete updates;
1219 set_deferred_updates(NULL);
1220 }
1221
1222 // All Java related clean up happens in exit
1223 ThreadSafepointState::destroy(this);
1224 if (_thread_stat != NULL) delete _thread_stat;
1225
1226 #if INCLUDE_JVMCI
1227 if (JVMCICounterSize > 0) {
1228 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
1229 }
1230 #endif // INCLUDE_JVMCI
1231 }
1232
1233
1234 // First JavaThread specific code executed by a new Java thread.
1235 void JavaThread::pre_run() {
1236 // empty - see comments in run()
1237 }
1238
1239 // The main routine called by a new Java thread. This isn't overridden
1240 // by subclasses, instead different subclasses define a different "entry_point"
1241 // which defines the actual logic for that kind of thread.
1242 void JavaThread::run() {
1243 // initialize thread-local alloc buffer related fields
1244 initialize_tlab();
1245
1246 _stack_overflow_state.create_stack_guard_pages();
1247
1248 cache_global_variables();
1249
1250 // Thread is now sufficiently initialized to be handled by the safepoint code as being
1251 // in the VM. Change thread state from _thread_new to _thread_in_vm
1252 assert(this->thread_state() == _thread_new, "wrong thread state");
1253 set_thread_state(_thread_in_vm);
1254
1255 // Before a thread is on the threads list it is always safe, so after leaving the
1256 // _thread_new we should emit a instruction barrier. The distance to modified code
1257 // from here is probably far enough, but this is consistent and safe.
1258 OrderAccess::cross_modify_fence();
1259
1260 assert(JavaThread::current() == this, "sanity check");
1261 assert(!Thread::current()->owns_locks(), "sanity check");
1262
1263 DTRACE_THREAD_PROBE(start, this);
1264
1265 // This operation might block. We call that after all safepoint checks for a new thread has
1266 // been completed.
1267 set_active_handles(JNIHandleBlock::allocate_block());
1268
1269 if (JvmtiExport::should_post_thread_life()) {
1270 JvmtiExport::post_thread_start(this);
1271
1272 }
1273
1274 // We call another function to do the rest so we are sure that the stack addresses used
1275 // from there will be lower than the stack base just computed.
1276 thread_main_inner();
1277 }
1278
1279 void JavaThread::thread_main_inner() {
1280 assert(JavaThread::current() == this, "sanity check");
1281 assert(_threadObj.peek() != NULL, "just checking");
1282
1283 // Execute thread entry point unless this thread has a pending exception
1284 // or has been stopped before starting.
1285 // Note: Due to JVM_StopThread we can have pending exceptions already!
1286 if (!this->has_pending_exception() &&
1287 !java_lang_Thread::is_stillborn(this->threadObj())) {
1288 {
1289 ResourceMark rm(this);
1290 this->set_native_thread_name(this->name());
1291 }
1292 HandleMark hm(this);
1293 this->entry_point()(this, this);
1294 }
1295
1296 DTRACE_THREAD_PROBE(stop, this);
1297
1298 // Cleanup is handled in post_run()
1299 }
1300
1301 // Shared teardown for all JavaThreads
1302 void JavaThread::post_run() {
1303 this->exit(false);
1304 this->unregister_thread_stack_with_NMT();
1305 // Defer deletion to here to ensure 'this' is still referenceable in call_run
1306 // for any shared tear-down.
1307 this->smr_delete();
1308 }
1309
1310 static void ensure_join(JavaThread* thread) {
1311 // We do not need to grab the Threads_lock, since we are operating on ourself.
1312 Handle threadObj(thread, thread->threadObj());
1313 assert(threadObj.not_null(), "java thread object must exist");
1314 ObjectLocker lock(threadObj, thread);
1315 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1316 thread->clear_pending_exception();
1317 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1318 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
1319 // Clear the native thread instance - this makes isAlive return false and allows the join()
1320 // to complete once we've done the notify_all below
1321 java_lang_Thread::set_thread(threadObj(), NULL);
1322 lock.notify_all(thread);
1323 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1324 thread->clear_pending_exception();
1325 }
1326
1327 static bool is_daemon(oop threadObj) {
1328 return (threadObj != NULL && java_lang_Thread::is_daemon(threadObj));
1329 }
1330
1331 // For any new cleanup additions, please check to see if they need to be applied to
1332 // cleanup_failed_attach_current_thread as well.
1333 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1334 assert(this == JavaThread::current(), "thread consistency check");
1335
1336 elapsedTimer _timer_exit_phase1;
1337 elapsedTimer _timer_exit_phase2;
1338 elapsedTimer _timer_exit_phase3;
1339 elapsedTimer _timer_exit_phase4;
1340
1341 if (log_is_enabled(Debug, os, thread, timer)) {
1342 _timer_exit_phase1.start();
1343 }
1344
1345 HandleMark hm(this);
1346 Handle uncaught_exception(this, this->pending_exception());
1347 this->clear_pending_exception();
1348 Handle threadObj(this, this->threadObj());
1349 assert(threadObj.not_null(), "Java thread object should be created");
1350
1351 if (!destroy_vm) {
1352 if (uncaught_exception.not_null()) {
1353 EXCEPTION_MARK;
1354 // Call method Thread.dispatchUncaughtException().
1355 Klass* thread_klass = vmClasses::Thread_klass();
1356 JavaValue result(T_VOID);
1357 JavaCalls::call_virtual(&result,
1358 threadObj, thread_klass,
1359 vmSymbols::dispatchUncaughtException_name(),
1360 vmSymbols::throwable_void_signature(),
1361 uncaught_exception,
1362 THREAD);
1363 if (HAS_PENDING_EXCEPTION) {
1364 ResourceMark rm(this);
1365 jio_fprintf(defaultStream::error_stream(),
1366 "\nException: %s thrown from the UncaughtExceptionHandler"
1367 " in thread \"%s\"\n",
1368 pending_exception()->klass()->external_name(),
1369 name());
1370 CLEAR_PENDING_EXCEPTION;
1371 }
1372 }
1373
1374 if (!is_Compiler_thread()) {
1375 // We have finished executing user-defined Java code and now have to do the
1376 // implementation specific clean-up by calling Thread.exit(). We prevent any
1377 // asynchronous exceptions from being delivered while in Thread.exit()
1378 // to ensure the clean-up is not corrupted.
1379 NoAsyncExceptionDeliveryMark _no_async(this);
1380
1381 EXCEPTION_MARK;
1382 JavaValue result(T_VOID);
1383 Klass* thread_klass = vmClasses::Thread_klass();
1384 JavaCalls::call_virtual(&result,
1385 threadObj, thread_klass,
1386 vmSymbols::exit_method_name(),
1387 vmSymbols::void_method_signature(),
1388 THREAD);
1389 CLEAR_PENDING_EXCEPTION;
1390 }
1391
1392 // notify JVMTI
1393 if (JvmtiExport::should_post_thread_life()) {
1394 JvmtiExport::post_thread_end(this);
1395 }
1396
1397 // The careful dance between thread suspension and exit is handled here.
1398 // Since we are in thread_in_vm state and suspension is done with handshakes,
1399 // we can just put in the exiting state and it will be correctly handled.
1400 set_terminated(_thread_exiting);
1401
1402 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
1403 } else {
1404 assert(!is_terminated() && !is_exiting(), "must not be exiting");
1405 // before_exit() has already posted JVMTI THREAD_END events
1406 }
1407
1408 if (log_is_enabled(Debug, os, thread, timer)) {
1409 _timer_exit_phase1.stop();
1410 _timer_exit_phase2.start();
1411 }
1412
1413 // Capture daemon status before the thread is marked as terminated.
1414 bool daemon = is_daemon(threadObj());
1415
1416 // Notify waiters on thread object. This has to be done after exit() is called
1417 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1418 // group should have the destroyed bit set before waiters are notified).
1419 ensure_join(this);
1420 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1421
1422 if (log_is_enabled(Debug, os, thread, timer)) {
1423 _timer_exit_phase2.stop();
1424 _timer_exit_phase3.start();
1425 }
1426 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1427 // held by this thread must be released. The spec does not distinguish
1428 // between JNI-acquired and regular Java monitors. We can only see
1429 // regular Java monitors here if monitor enter-exit matching is broken.
1430 //
1431 // ensure_join() ignores IllegalThreadStateExceptions, and so does
1432 // ObjectSynchronizer::release_monitors_owned_by_thread().
1433 if (exit_type == jni_detach) {
1434 // Sanity check even though JNI DetachCurrentThread() would have
1435 // returned JNI_ERR if there was a Java frame. JavaThread exit
1436 // should be done executing Java code by the time we get here.
1437 assert(!this->has_last_Java_frame(),
1438 "should not have a Java frame when detaching or exiting");
1439 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1440 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1441 }
1442
1443 // These things needs to be done while we are still a Java Thread. Make sure that thread
1444 // is in a consistent state, in case GC happens
1445 JFR_ONLY(Jfr::on_thread_exit(this);)
1446
1447 if (active_handles() != NULL) {
1448 JNIHandleBlock* block = active_handles();
1449 set_active_handles(NULL);
1450 JNIHandleBlock::release_block(block);
1451 }
1452
1453 if (free_handle_block() != NULL) {
1454 JNIHandleBlock* block = free_handle_block();
1455 set_free_handle_block(NULL);
1456 JNIHandleBlock::release_block(block);
1457 }
1458
1459 // These have to be removed while this is still a valid thread.
1460 _stack_overflow_state.remove_stack_guard_pages();
1461
1462 if (UseTLAB) {
1463 tlab().retire();
1464 }
1465
1466 if (JvmtiEnv::environments_might_exist()) {
1467 JvmtiExport::cleanup_thread(this);
1468 }
1469
1470 // We need to cache the thread name for logging purposes below as once
1471 // we have called on_thread_detach this thread must not access any oops.
1472 char* thread_name = NULL;
1473 if (log_is_enabled(Debug, os, thread, timer)) {
1474 ResourceMark rm(this);
1475 thread_name = os::strdup(name());
1476 }
1477
1478 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
1479 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
1480 os::current_thread_id());
1481
1482 if (log_is_enabled(Debug, os, thread, timer)) {
1483 _timer_exit_phase3.stop();
1484 _timer_exit_phase4.start();
1485 }
1486
1487 #if INCLUDE_JVMCI
1488 if (JVMCICounterSize > 0) {
1489 if (jvmci_counters_include(this)) {
1490 for (int i = 0; i < JVMCICounterSize; i++) {
1491 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
1492 }
1493 }
1494 }
1495 #endif // INCLUDE_JVMCI
1496
1497 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1498 Threads::remove(this, daemon);
1499
1500 if (log_is_enabled(Debug, os, thread, timer)) {
1501 _timer_exit_phase4.stop();
1502 log_debug(os, thread, timer)("name='%s'"
1503 ", exit-phase1=" JLONG_FORMAT
1504 ", exit-phase2=" JLONG_FORMAT
1505 ", exit-phase3=" JLONG_FORMAT
1506 ", exit-phase4=" JLONG_FORMAT,
1507 thread_name,
1508 _timer_exit_phase1.milliseconds(),
1509 _timer_exit_phase2.milliseconds(),
1510 _timer_exit_phase3.milliseconds(),
1511 _timer_exit_phase4.milliseconds());
1512 os::free(thread_name);
1513 }
1514 }
1515
1516 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
1517 if (active_handles() != NULL) {
1518 JNIHandleBlock* block = active_handles();
1519 set_active_handles(NULL);
1520 JNIHandleBlock::release_block(block);
1521 }
1522
1523 if (free_handle_block() != NULL) {
1524 JNIHandleBlock* block = free_handle_block();
1525 set_free_handle_block(NULL);
1526 JNIHandleBlock::release_block(block);
1527 }
1528
1529 // These have to be removed while this is still a valid thread.
1530 _stack_overflow_state.remove_stack_guard_pages();
1531
1532 if (UseTLAB) {
1533 tlab().retire();
1534 }
1535
1536 Threads::remove(this, is_daemon);
1537 this->smr_delete();
1538 }
1539
1540 JavaThread* JavaThread::active() {
1541 Thread* thread = Thread::current();
1542 if (thread->is_Java_thread()) {
1543 return JavaThread::cast(thread);
1544 } else {
1545 assert(thread->is_VM_thread(), "this must be a vm thread");
1546 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1547 JavaThread *ret = op == NULL ? NULL : JavaThread::cast(op->calling_thread());
1548 return ret;
1549 }
1550 }
1551
1552 bool JavaThread::is_lock_owned(address adr) const {
1553 if (Thread::is_lock_owned(adr)) return true;
1554
1555 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1556 if (chunk->contains(adr)) return true;
1557 }
1558
1559 return false;
1560 }
1561
1562 oop JavaThread::exception_oop() const {
1563 return Atomic::load(&_exception_oop);
1564 }
1565
1566 void JavaThread::set_exception_oop(oop o) {
1567 Atomic::store(&_exception_oop, o);
1568 }
1569
1570 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1571 chunk->set_next(monitor_chunks());
1572 set_monitor_chunks(chunk);
1573 }
1574
1575 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1576 guarantee(monitor_chunks() != NULL, "must be non empty");
1577 if (monitor_chunks() == chunk) {
1578 set_monitor_chunks(chunk->next());
1579 } else {
1580 MonitorChunk* prev = monitor_chunks();
1581 while (prev->next() != chunk) prev = prev->next();
1582 prev->set_next(chunk->next());
1583 }
1584 }
1585
1586 void JavaThread::handle_special_runtime_exit_condition() {
1587 if (is_obj_deopt_suspend()) {
1588 frame_anchor()->make_walkable(this);
1589 wait_for_object_deoptimization();
1590 }
1591 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1592 }
1593
1594
1595 // Asynchronous exceptions support
1596 //
1597 void JavaThread::handle_async_exception(oop java_throwable) {
1598 assert(java_throwable != NULL, "should have an _async_exception to throw");
1599 assert(!is_at_poll_safepoint(), "should have never called this method");
1600
1601 if (has_last_Java_frame()) {
1602 frame f = last_frame();
1603 if (f.is_runtime_frame()) {
1604 // If the topmost frame is a runtime stub, then we are calling into
1605 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1606 // must deoptimize the caller before continuing, as the compiled exception
1607 // handler table may not be valid.
1608 RegisterMap reg_map(this, false);
1609 frame compiled_frame = f.sender(®_map);
1610 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1611 Deoptimization::deoptimize(this, compiled_frame);
1612 }
1613 }
1614 }
1615
1616 // Only overwrite an already pending exception if it is not a ThreadDeath.
1617 if (!has_pending_exception() || !pending_exception()->is_a(vmClasses::ThreadDeath_klass())) {
1618
1619 // We cannot call Exceptions::_throw(...) here because we cannot block
1620 set_pending_exception(java_throwable, __FILE__, __LINE__);
1621
1622 LogTarget(Info, exceptions) lt;
1623 if (lt.is_enabled()) {
1624 ResourceMark rm;
1625 LogStream ls(lt);
1626 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1627 if (has_last_Java_frame()) {
1628 frame f = last_frame();
1629 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1630 }
1631 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1632 }
1633 }
1634 }
1635
1636 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1637 // Do not throw asynchronous exceptions against the compiler thread.
1638 if (!can_call_java()) {
1639 delete aeh;
1640 return;
1641 }
1642
1643 // Don't install a new pending async exception if there is already
1644 // a pending ThreadDeath one. Just interrupt thread from potential
1645 // wait()/sleep()/park() and return.
1646 if (has_async_exception_condition(true /* ThreadDeath_only */)) {
1647 java_lang_Thread::set_interrupted(threadObj(), true);
1648 this->interrupt();
1649 delete aeh;
1650 return;
1651 }
1652
1653 oop exception = aeh->exception();
1654 Handshake::execute(aeh, this); // Install asynchronous handshake
1655
1656 ResourceMark rm;
1657 if (log_is_enabled(Info, exceptions)) {
1658 log_info(exceptions)("Pending Async. exception installed of type: %s",
1659 InstanceKlass::cast(exception->klass())->external_name());
1660 }
1661 // for AbortVMOnException flag
1662 Exceptions::debug_check_abort(exception->klass()->external_name());
1663
1664 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1665 java_lang_Thread::set_interrupted(threadObj(), true);
1666 this->interrupt();
1667 }
1668
1669 class InstallAsyncExceptionHandshake : public HandshakeClosure {
1670 AsyncExceptionHandshake* _aeh;
1671 public:
1672 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1673 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1674 void do_thread(Thread* thr) {
1675 JavaThread* target = JavaThread::cast(thr);
1676 target->install_async_exception(_aeh);
1677 }
1678 };
1679
1680 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1681 OopHandle e(Universe::vm_global(), java_throwable);
1682 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1683 Handshake::execute(&iaeh, target);
1684 }
1685
1686
1687 // External suspension mechanism.
1688 //
1689 // Guarantees on return (for a valid target thread):
1690 // - Target thread will not execute any new bytecode.
1691 // - Target thread will not enter any new monitors.
1692 //
1693 bool JavaThread::java_suspend() {
1694 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1695 "missing ThreadsListHandle in calling context.");
1696 return this->handshake_state()->suspend();
1697 }
1698
1699 bool JavaThread::java_resume() {
1700 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1701 "missing ThreadsListHandle in calling context.");
1702 return this->handshake_state()->resume();
1703 }
1704
1705 // Wait for another thread to perform object reallocation and relocking on behalf of
1706 // this thread. The current thread is required to change to _thread_blocked in order
1707 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1708 // handshake safe, the other thread can complete the handshake used to synchronize
1709 // with this thread and then perform the reallocation and relocking.
1710 // See EscapeBarrier::sync_and_suspend_*()
1711
1712 void JavaThread::wait_for_object_deoptimization() {
1713 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1714 assert(this == Thread::current(), "invariant");
1715
1716 bool spin_wait = os::is_MP();
1717 do {
1718 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1719 // Wait for object deoptimization if requested.
1720 if (spin_wait) {
1721 // A single deoptimization is typically very short. Microbenchmarks
1722 // showed 5% better performance when spinning.
1723 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1724 SpinYield spin(spin_limit);
1725 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1726 spin.wait();
1727 }
1728 // Spin just once
1729 spin_wait = false;
1730 } else {
1731 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1732 if (is_obj_deopt_suspend()) {
1733 ml.wait();
1734 }
1735 }
1736 // A handshake for obj. deoptimization suspend could have been processed so
1737 // we must check after processing.
1738 } while (is_obj_deopt_suspend());
1739 }
1740
1741 #ifdef ASSERT
1742 // Verify the JavaThread has not yet been published in the Threads::list, and
1743 // hence doesn't need protection from concurrent access at this stage.
1744 void JavaThread::verify_not_published() {
1745 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1746 // since an unpublished JavaThread doesn't participate in the
1747 // Thread-SMR protocol for keeping a ThreadsList alive.
1748 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1749 }
1750 #endif
1751
1752 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1753 // pending, when _suspend_flags is non-zero or when we need to process a stack
1754 // watermark. Also check for pending async exceptions (except unsafe access error).
1755 // Note only the native==>Java barriers can call this function when thread state
1756 // is _thread_in_native_trans.
1757 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1758 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1759 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1760
1761 thread->set_thread_state(_thread_in_vm);
1762
1763 // Enable WXWrite: called directly from interpreter native wrapper.
1764 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1765
1766 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1767
1768 // After returning from native, it could be that the stack frames are not
1769 // yet safe to use. We catch such situations in the subsequent stack watermark
1770 // barrier, which will trap unsafe stack frames.
1771 StackWatermarkSet::before_unwind(thread);
1772 }
1773
1774 #ifndef PRODUCT
1775 // Deoptimization
1776 // Function for testing deoptimization
1777 void JavaThread::deoptimize() {
1778 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1779 bool deopt = false; // Dump stack only if a deopt actually happens.
1780 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1781 // Iterate over all frames in the thread and deoptimize
1782 for (; !fst.is_done(); fst.next()) {
1783 if (fst.current()->can_be_deoptimized()) {
1784
1785 if (only_at) {
1786 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1787 // consists of comma or carriage return separated numbers so
1788 // search for the current bci in that string.
1789 address pc = fst.current()->pc();
1790 nmethod* nm = (nmethod*) fst.current()->cb();
1791 ScopeDesc* sd = nm->scope_desc_at(pc);
1792 char buffer[8];
1793 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1794 size_t len = strlen(buffer);
1795 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1796 while (found != NULL) {
1797 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1798 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1799 // Check that the bci found is bracketed by terminators.
1800 break;
1801 }
1802 found = strstr(found + 1, buffer);
1803 }
1804 if (!found) {
1805 continue;
1806 }
1807 }
1808
1809 if (DebugDeoptimization && !deopt) {
1810 deopt = true; // One-time only print before deopt
1811 tty->print_cr("[BEFORE Deoptimization]");
1812 trace_frames();
1813 trace_stack();
1814 }
1815 Deoptimization::deoptimize(this, *fst.current());
1816 }
1817 }
1818
1819 if (DebugDeoptimization && deopt) {
1820 tty->print_cr("[AFTER Deoptimization]");
1821 trace_frames();
1822 }
1823 }
1824
1825
1826 // Make zombies
1827 void JavaThread::make_zombies() {
1828 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1829 if (fst.current()->can_be_deoptimized()) {
1830 // it is a Java nmethod
1831 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1832 nm->make_not_entrant();
1833 }
1834 }
1835 }
1836 #endif // PRODUCT
1837
1838
1839 void JavaThread::deoptimize_marked_methods() {
1840 if (!has_last_Java_frame()) return;
1841 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1842 for (; !fst.is_done(); fst.next()) {
1843 if (fst.current()->should_be_deoptimized()) {
1844 Deoptimization::deoptimize(this, *fst.current());
1845 }
1846 }
1847 }
1848
1849 #ifdef ASSERT
1850 void JavaThread::verify_frame_info() {
1851 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1852 (has_last_Java_frame() && java_call_counter() > 0),
1853 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1854 has_last_Java_frame() ? "true" : "false", java_call_counter());
1855 }
1856 #endif
1857
1858 // Push on a new block of JNI handles.
1859 void JavaThread::push_jni_handle_block() {
1860 // Allocate a new block for JNI handles.
1861 // Inlined code from jni_PushLocalFrame()
1862 JNIHandleBlock* old_handles = active_handles();
1863 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1864 assert(old_handles != NULL && new_handles != NULL, "should not be NULL");
1865 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1866 set_active_handles(new_handles);
1867 }
1868
1869 // Pop off the current block of JNI handles.
1870 void JavaThread::pop_jni_handle_block() {
1871 // Release our JNI handle block
1872 JNIHandleBlock* old_handles = active_handles();
1873 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1874 assert(new_handles != nullptr, "should never set active handles to null");
1875 set_active_handles(new_handles);
1876 old_handles->set_pop_frame_link(NULL);
1877 JNIHandleBlock::release_block(old_handles, this);
1878 }
1879
1880 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1881 // Verify that the deferred card marks have been flushed.
1882 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1883
1884 // Traverse the GCHandles
1885 Thread::oops_do_no_frames(f, cf);
1886
1887 if (active_handles() != NULL) {
1888 active_handles()->oops_do(f);
1889 }
1890
1891 DEBUG_ONLY(verify_frame_info();)
1892
1893 if (has_last_Java_frame()) {
1894 // Traverse the monitor chunks
1895 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1896 chunk->oops_do(f);
1897 }
1898 }
1899
1900 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
1901 // If we have deferred set_locals there might be oops waiting to be
1902 // written
1903 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1904 if (list != NULL) {
1905 for (int i = 0; i < list->length(); i++) {
1906 list->at(i)->oops_do(f);
1907 }
1908 }
1909
1910 // Traverse instance variables at the end since the GC may be moving things
1911 // around using this function
1912 f->do_oop((oop*) &_vm_result);
1913 f->do_oop((oop*) &_exception_oop);
1914 #if INCLUDE_JVMCI
1915 f->do_oop((oop*) &_jvmci_reserved_oop0);
1916 #endif
1917
1918 if (jvmti_thread_state() != NULL) {
1919 jvmti_thread_state()->oops_do(f, cf);
1920 }
1921 }
1922
1923 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
1924 if (!has_last_Java_frame()) {
1925 return;
1926 }
1927 // Finish any pending lazy GC activity for the frames
1928 StackWatermarkSet::finish_processing(this, NULL /* context */, StackWatermarkKind::gc);
1929 // Traverse the execution stack
1930 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1931 fst.current()->oops_do(f, cf, fst.register_map());
1932 }
1933 }
1934
1935 #ifdef ASSERT
1936 void JavaThread::verify_states_for_handshake() {
1937 // This checks that the thread has a correct frame state during a handshake.
1938 verify_frame_info();
1939 }
1940 #endif
1941
1942 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1943 DEBUG_ONLY(verify_frame_info();)
1944
1945 if (has_last_Java_frame()) {
1946 // Traverse the execution stack
1947 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1948 fst.current()->nmethods_do(cf);
1949 }
1950 }
1951
1952 if (jvmti_thread_state() != NULL) {
1953 jvmti_thread_state()->nmethods_do(cf);
1954 }
1955 }
1956
1957 void JavaThread::metadata_do(MetadataClosure* f) {
1958 if (has_last_Java_frame()) {
1959 // Traverse the execution stack to call f() on the methods in the stack
1960 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1961 fst.current()->metadata_do(f);
1962 }
1963 } else if (is_Compiler_thread()) {
1964 // need to walk ciMetadata in current compile tasks to keep alive.
1965 CompilerThread* ct = (CompilerThread*)this;
1966 if (ct->env() != NULL) {
1967 ct->env()->metadata_do(f);
1968 }
1969 CompileTask* task = ct->task();
1970 if (task != NULL) {
1971 task->metadata_do(f);
1972 }
1973 }
1974 }
1975
1976 // Printing
1977 const char* _get_thread_state_name(JavaThreadState _thread_state) {
1978 switch (_thread_state) {
1979 case _thread_uninitialized: return "_thread_uninitialized";
1980 case _thread_new: return "_thread_new";
1981 case _thread_new_trans: return "_thread_new_trans";
1982 case _thread_in_native: return "_thread_in_native";
1983 case _thread_in_native_trans: return "_thread_in_native_trans";
1984 case _thread_in_vm: return "_thread_in_vm";
1985 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1986 case _thread_in_Java: return "_thread_in_Java";
1987 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1988 case _thread_blocked: return "_thread_blocked";
1989 case _thread_blocked_trans: return "_thread_blocked_trans";
1990 default: return "unknown thread state";
1991 }
1992 }
1993
1994 #ifndef PRODUCT
1995 void JavaThread::print_thread_state_on(outputStream *st) const {
1996 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1997 };
1998 #endif // PRODUCT
1999
2000 // Called by Threads::print() for VM_PrintThreads operation
2001 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
2002 st->print_raw("\"");
2003 st->print_raw(name());
2004 st->print_raw("\" ");
2005 oop thread_oop = threadObj();
2006 if (thread_oop != NULL) {
2007 st->print("#" INT64_FORMAT " ", (int64_t)java_lang_Thread::thread_id(thread_oop));
2008 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2009 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2010 }
2011 Thread::print_on(st, print_extended_info);
2012 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2013 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2014 if (thread_oop != NULL) {
2015 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2016 }
2017 #ifndef PRODUCT
2018 _safepoint_state->print_on(st);
2019 #endif // PRODUCT
2020 if (is_Compiler_thread()) {
2021 CompileTask *task = ((CompilerThread*)this)->task();
2022 if (task != NULL) {
2023 st->print(" Compiling: ");
2024 task->print(st, NULL, true, false);
2025 } else {
2026 st->print(" No compile task");
2027 }
2028 st->cr();
2029 }
2030 }
2031
2032 void JavaThread::print() const { print_on(tty); }
2033
2034 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
2035 st->print("%s", get_thread_name_string(buf, buflen));
2036 }
2037
2038 // Called by fatal error handler. The difference between this and
2039 // JavaThread::print() is that we can't grab lock or allocate memory.
2040 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2041 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
2042 oop thread_obj = threadObj();
2043 if (thread_obj != NULL) {
2044 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2045 }
2046 st->print(" [");
2047 st->print("%s", _get_thread_state_name(_thread_state));
2048 if (osthread()) {
2049 st->print(", id=%d", osthread()->thread_id());
2050 }
2051 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2052 p2i(stack_end()), p2i(stack_base()));
2053 st->print("]");
2054
2055 ThreadsSMRSupport::print_info_on(this, st);
2056 return;
2057 }
2058
2059
2060 // Verification
2061
2062 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2063 // ignore if there is no stack
2064 if (!has_last_Java_frame()) return;
2065 // traverse the stack frames. Starts from top frame.
2066 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2067 frame* fr = fst.current();
2068 f(fr, fst.register_map());
2069 }
2070 }
2071
2072 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2073
2074 void JavaThread::verify() {
2075 // Verify oops in the thread.
2076 oops_do(&VerifyOopClosure::verify_oop, NULL);
2077
2078 // Verify the stack frames.
2079 frames_do(frame_verify);
2080 }
2081
2082 // CR 6300358 (sub-CR 2137150)
2083 // Most callers of this method assume that it can't return NULL but a
2084 // thread may not have a name whilst it is in the process of attaching to
2085 // the VM - see CR 6412693, and there are places where a JavaThread can be
2086 // seen prior to having its threadObj set (e.g., JNI attaching threads and
2087 // if vm exit occurs during initialization). These cases can all be accounted
2088 // for such that this method never returns NULL.
2089 const char* JavaThread::name() const {
2090 if (Thread::is_JavaThread_protected(/* target */ this)) {
2091 // The target JavaThread is protected so get_thread_name_string() is safe:
2092 return get_thread_name_string();
2093 }
2094
2095 // The target JavaThread is not protected so we return the default:
2096 return Thread::name();
2097 }
2098
2099 // Returns a non-NULL representation of this thread's name, or a suitable
2100 // descriptive string if there is no set name.
2101 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2102 const char* name_str;
2103 oop thread_obj = threadObj();
2104 if (thread_obj != NULL) {
2105 oop name = java_lang_Thread::name(thread_obj);
2106 if (name != NULL) {
2107 if (buf == NULL) {
2108 name_str = java_lang_String::as_utf8_string(name);
2109 } else {
2110 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
2111 }
2112 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2113 name_str = "<no-name - thread is attaching>";
2114 } else {
2115 name_str = "<un-named>";
2116 }
2117 } else {
2118 name_str = Thread::name();
2119 }
2120 assert(name_str != NULL, "unexpected NULL thread name");
2121 return name_str;
2122 }
2123
2124 // Helper to extract the name from the thread oop for logging.
2125 const char* JavaThread::name_for(oop thread_obj) {
2126 assert(thread_obj != NULL, "precondition");
2127 oop name = java_lang_Thread::name(thread_obj);
2128 const char* name_str;
2129 if (name != NULL) {
2130 name_str = java_lang_String::as_utf8_string(name);
2131 } else {
2132 name_str = "<un-named>";
2133 }
2134 return name_str;
2135 }
2136
2137 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2138
2139 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2140 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
2141 // Link Java Thread object <-> C++ Thread
2142
2143 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2144 // and put it into a new Handle. The Handle "thread_oop" can then
2145 // be used to pass the C++ thread object to other methods.
2146
2147 // Set the Java level thread object (jthread) field of the
2148 // new thread (a JavaThread *) to C++ thread object using the
2149 // "thread_oop" handle.
2150
2151 // Set the thread field (a JavaThread *) of the
2152 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
2153
2154 Handle thread_oop(Thread::current(),
2155 JNIHandles::resolve_non_null(jni_thread));
2156 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
2157 "must be initialized");
2158 set_threadObj(thread_oop());
2159 java_lang_Thread::set_thread(thread_oop(), this);
2160
2161 if (prio == NoPriority) {
2162 prio = java_lang_Thread::priority(thread_oop());
2163 assert(prio != NoPriority, "A valid priority should be present");
2164 }
2165
2166 // Push the Java priority down to the native thread; needs Threads_lock
2167 Thread::set_priority(this, prio);
2168
2169 // Add the new thread to the Threads list and set it in motion.
2170 // We must have threads lock in order to call Threads::add.
2171 // It is crucial that we do not block before the thread is
2172 // added to the Threads list for if a GC happens, then the java_thread oop
2173 // will not be visited by GC.
2174 Threads::add(this);
2175 }
2176
2177 oop JavaThread::current_park_blocker() {
2178 // Support for JSR-166 locks
2179 oop thread_oop = threadObj();
2180 if (thread_oop != NULL) {
2181 return java_lang_Thread::park_blocker(thread_oop);
2182 }
2183 return NULL;
2184 }
2185
2186
2187 void JavaThread::print_stack_on(outputStream* st) {
2188 if (!has_last_Java_frame()) return;
2189
2190 Thread* current_thread = Thread::current();
2191 ResourceMark rm(current_thread);
2192 HandleMark hm(current_thread);
2193
2194 RegisterMap reg_map(this);
2195 vframe* start_vf = last_java_vframe(®_map);
2196 int count = 0;
2197 for (vframe* f = start_vf; f != NULL; f = f->sender()) {
2198 if (f->is_java_frame()) {
2199 javaVFrame* jvf = javaVFrame::cast(f);
2200 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
2201
2202 // Print out lock information
2203 if (JavaMonitorsInStackTrace) {
2204 jvf->print_lock_info_on(st, count);
2205 }
2206 } else {
2207 // Ignore non-Java frames
2208 }
2209
2210 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
2211 count++;
2212 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
2213 }
2214 }
2215
2216
2217 // JVMTI PopFrame support
2218 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
2219 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
2220 if (in_bytes(size_in_bytes) != 0) {
2221 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
2222 _popframe_preserved_args_size = in_bytes(size_in_bytes);
2223 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
2224 }
2225 }
2226
2227 void* JavaThread::popframe_preserved_args() {
2228 return _popframe_preserved_args;
2229 }
2230
2231 ByteSize JavaThread::popframe_preserved_args_size() {
2232 return in_ByteSize(_popframe_preserved_args_size);
2233 }
2234
2235 WordSize JavaThread::popframe_preserved_args_size_in_words() {
2236 int sz = in_bytes(popframe_preserved_args_size());
2237 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
2238 return in_WordSize(sz / wordSize);
2239 }
2240
2241 void JavaThread::popframe_free_preserved_args() {
2242 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
2243 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
2244 _popframe_preserved_args = NULL;
2245 _popframe_preserved_args_size = 0;
2246 }
2247
2248 #ifndef PRODUCT
2249
2250 void JavaThread::trace_frames() {
2251 tty->print_cr("[Describe stack]");
2252 int frame_no = 1;
2253 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2254 tty->print(" %d. ", frame_no++);
2255 fst.current()->print_value_on(tty, this);
2256 tty->cr();
2257 }
2258 }
2259
2260 class PrintAndVerifyOopClosure: public OopClosure {
2261 protected:
2262 template <class T> inline void do_oop_work(T* p) {
2263 oop obj = RawAccess<>::oop_load(p);
2264 if (obj == NULL) return;
2265 tty->print(INTPTR_FORMAT ": ", p2i(p));
2266 if (oopDesc::is_oop_or_null(obj)) {
2267 if (obj->is_objArray()) {
2268 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
2269 } else {
2270 obj->print();
2271 }
2272 } else {
2273 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
2274 }
2275 tty->cr();
2276 }
2277 public:
2278 virtual void do_oop(oop* p) { do_oop_work(p); }
2279 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
2280 };
2281
2282 #ifdef ASSERT
2283 // Print or validate the layout of stack frames
2284 void JavaThread::print_frame_layout(int depth, bool validate_only) {
2285 ResourceMark rm;
2286 PreserveExceptionMark pm(this);
2287 FrameValues values;
2288 int frame_no = 0;
2289 for (StackFrameStream fst(this, false /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
2290 fst.current()->describe(values, ++frame_no);
2291 if (depth == frame_no) break;
2292 }
2293 if (validate_only) {
2294 values.validate();
2295 } else {
2296 tty->print_cr("[Describe stack layout]");
2297 values.print(this);
2298 }
2299 }
2300 #endif
2301
2302 void JavaThread::trace_stack_from(vframe* start_vf) {
2303 ResourceMark rm;
2304 int vframe_no = 1;
2305 for (vframe* f = start_vf; f; f = f->sender()) {
2306 if (f->is_java_frame()) {
2307 javaVFrame::cast(f)->print_activation(vframe_no++);
2308 } else {
2309 f->print();
2310 }
2311 if (vframe_no > StackPrintLimit) {
2312 tty->print_cr("...<more frames>...");
2313 return;
2314 }
2315 }
2316 }
2317
2318
2319 void JavaThread::trace_stack() {
2320 if (!has_last_Java_frame()) return;
2321 Thread* current_thread = Thread::current();
2322 ResourceMark rm(current_thread);
2323 HandleMark hm(current_thread);
2324 RegisterMap reg_map(this);
2325 trace_stack_from(last_java_vframe(®_map));
2326 }
2327
2328
2329 #endif // PRODUCT
2330
2331
2332 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
2333 assert(reg_map != NULL, "a map must be given");
2334 frame f = last_frame();
2335 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
2336 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2337 }
2338 return NULL;
2339 }
2340
2341
2342 Klass* JavaThread::security_get_caller_class(int depth) {
2343 vframeStream vfst(this);
2344 vfst.security_get_caller_frame(depth);
2345 if (!vfst.at_end()) {
2346 return vfst.method()->method_holder();
2347 }
2348 return NULL;
2349 }
2350
2351 // java.lang.Thread.sleep support
2352 // Returns true if sleep time elapsed as expected, and false
2353 // if the thread was interrupted.
2354 bool JavaThread::sleep(jlong millis) {
2355 assert(this == Thread::current(), "thread consistency check");
2356
2357 ParkEvent * const slp = this->_SleepEvent;
2358 // Because there can be races with thread interruption sending an unpark()
2359 // to the event, we explicitly reset it here to avoid an immediate return.
2360 // The actual interrupt state will be checked before we park().
2361 slp->reset();
2362 // Thread interruption establishes a happens-before ordering in the
2363 // Java Memory Model, so we need to ensure we synchronize with the
2364 // interrupt state.
2365 OrderAccess::fence();
2366
2367 jlong prevtime = os::javaTimeNanos();
2368
2369 for (;;) {
2370 // interruption has precedence over timing out
2371 if (this->is_interrupted(true)) {
2372 return false;
2373 }
2374
2375 if (millis <= 0) {
2376 return true;
2377 }
2378
2379 {
2380 ThreadBlockInVM tbivm(this);
2381 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2382 slp->park(millis);
2383 }
2384
2385 // Update elapsed time tracking
2386 jlong newtime = os::javaTimeNanos();
2387 if (newtime - prevtime < 0) {
2388 // time moving backwards, should only happen if no monotonic clock
2389 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2390 assert(false,
2391 "unexpected time moving backwards detected in JavaThread::sleep()");
2392 } else {
2393 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2394 }
2395 prevtime = newtime;
2396 }
2397 }
2398
2399
2400 // ======= Threads ========
2401
2402 // The Threads class links together all active threads, and provides
2403 // operations over all threads. It is protected by the Threads_lock,
2404 // which is also used in other global contexts like safepointing.
2405 // ThreadsListHandles are used to safely perform operations on one
2406 // or more threads without the risk of the thread exiting during the
2407 // operation.
2408 //
2409 // Note: The Threads_lock is currently more widely used than we
2410 // would like. We are actively migrating Threads_lock uses to other
2411 // mechanisms in order to reduce Threads_lock contention.
2412
2413 int Threads::_number_of_threads = 0;
2414 int Threads::_number_of_non_daemon_threads = 0;
2415 int Threads::_return_code = 0;
2416 uintx Threads::_thread_claim_token = 1; // Never zero.
2417 size_t JavaThread::_stack_size_at_create = 0;
2418
2419 #ifdef ASSERT
2420 bool Threads::_vm_complete = false;
2421 #endif
2422
2423 // All NonJavaThreads (i.e., every non-JavaThread in the system).
2424 void Threads::non_java_threads_do(ThreadClosure* tc) {
2425 NoSafepointVerifier nsv;
2426 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
2427 tc->do_thread(njti.current());
2428 }
2429 }
2430
2431 // All JavaThreads
2432 #define ALL_JAVA_THREADS(X) \
2433 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
2434
2435 // All JavaThreads
2436 void Threads::java_threads_do(ThreadClosure* tc) {
2437 assert_locked_or_safepoint(Threads_lock);
2438 // ALL_JAVA_THREADS iterates through all JavaThreads.
2439 ALL_JAVA_THREADS(p) {
2440 tc->do_thread(p);
2441 }
2442 }
2443
2444 void Threads::java_threads_and_vm_thread_do(ThreadClosure* tc) {
2445 assert_locked_or_safepoint(Threads_lock);
2446 java_threads_do(tc);
2447 tc->do_thread(VMThread::vm_thread());
2448 }
2449
2450 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
2451 void Threads::threads_do(ThreadClosure* tc) {
2452 assert_locked_or_safepoint(Threads_lock);
2453 java_threads_do(tc);
2454 non_java_threads_do(tc);
2455 }
2456
2457 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
2458 uintx claim_token = Threads::thread_claim_token();
2459 ALL_JAVA_THREADS(p) {
2460 if (p->claim_threads_do(is_par, claim_token)) {
2461 tc->do_thread(p);
2462 }
2463 }
2464 VMThread* vmt = VMThread::vm_thread();
2465 if (vmt->claim_threads_do(is_par, claim_token)) {
2466 tc->do_thread(vmt);
2467 }
2468 }
2469
2470 // The system initialization in the library has three phases.
2471 //
2472 // Phase 1: java.lang.System class initialization
2473 // java.lang.System is a primordial class loaded and initialized
2474 // by the VM early during startup. java.lang.System.<clinit>
2475 // only does registerNatives and keeps the rest of the class
2476 // initialization work later until thread initialization completes.
2477 //
2478 // System.initPhase1 initializes the system properties, the static
2479 // fields in, out, and err. Set up java signal handlers, OS-specific
2480 // system settings, and thread group of the main thread.
2481 static void call_initPhase1(TRAPS) {
2482 Klass* klass = vmClasses::System_klass();
2483 JavaValue result(T_VOID);
2484 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
2485 vmSymbols::void_method_signature(), CHECK);
2486 }
2487
2488 // Phase 2. Module system initialization
2489 // This will initialize the module system. Only java.base classes
2490 // can be loaded until phase 2 completes.
2491 //
2492 // Call System.initPhase2 after the compiler initialization and jsr292
2493 // classes get initialized because module initialization runs a lot of java
2494 // code, that for performance reasons, should be compiled. Also, this will
2495 // enable the startup code to use lambda and other language features in this
2496 // phase and onward.
2497 //
2498 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
2499 static void call_initPhase2(TRAPS) {
2500 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
2501
2502 Klass* klass = vmClasses::System_klass();
2503
2504 JavaValue result(T_INT);
2505 JavaCallArguments args;
2506 args.push_int(DisplayVMOutputToStderr);
2507 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
2508 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
2509 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
2510 if (result.get_jint() != JNI_OK) {
2511 vm_exit_during_initialization(); // no message or exception
2512 }
2513
2514 universe_post_module_init();
2515 }
2516
2517 // Phase 3. final setup - set security manager, system class loader and TCCL
2518 //
2519 // This will instantiate and set the security manager, set the system class
2520 // loader as well as the thread context class loader. The security manager
2521 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
2522 // other modules or the application's classpath.
2523 static void call_initPhase3(TRAPS) {
2524 Klass* klass = vmClasses::System_klass();
2525 JavaValue result(T_VOID);
2526 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
2527 vmSymbols::void_method_signature(), CHECK);
2528 }
2529
2530 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
2531 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
2532
2533 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
2534 create_vm_init_libraries();
2535 }
2536
2537 initialize_class(vmSymbols::java_lang_String(), CHECK);
2538
2539 // Inject CompactStrings value after the static initializers for String ran.
2540 java_lang_String::set_compact_strings(CompactStrings);
2541
2542 // Initialize java_lang.System (needed before creating the thread)
2543 initialize_class(vmSymbols::java_lang_System(), CHECK);
2544 // The VM creates & returns objects of this class. Make sure it's initialized.
2545 initialize_class(vmSymbols::java_lang_Class(), CHECK);
2546 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
2547 Handle thread_group = create_initial_thread_group(CHECK);
2548 Universe::set_main_thread_group(thread_group());
2549 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
2550 create_initial_thread(thread_group, main_thread, CHECK);
2551
2552 // The VM creates objects of this class.
2553 initialize_class(vmSymbols::java_lang_Module(), CHECK);
2554
2555 #ifdef ASSERT
2556 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
2557 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
2558 #endif
2559
2560 // initialize the hardware-specific constants needed by Unsafe
2561 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
2562 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
2563
2564 // The VM preresolves methods to these classes. Make sure that they get initialized
2565 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
2566 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
2567
2568 // Phase 1 of the system initialization in the library, java.lang.System class initialization
2569 call_initPhase1(CHECK);
2570
2571 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
2572 // Some values are actually configure-time constants but some can be set via the jlink tool and
2573 // so must be read dynamically. We treat them all the same.
2574 InstanceKlass* ik = SystemDictionary::find_instance_klass(vmSymbols::java_lang_VersionProps(),
2575 Handle(), Handle());
2576 {
2577 ResourceMark rm(main_thread);
2578 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
2579
2580 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
2581
2582 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
2583
2584 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
2585
2586 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
2587 }
2588
2589 // an instance of OutOfMemory exception has been allocated earlier
2590 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
2591 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
2592 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
2593 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
2594 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
2595 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
2596 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
2597 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
2598 }
2599
2600 void Threads::initialize_jsr292_core_classes(TRAPS) {
2601 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
2602
2603 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
2604 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
2605 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
2606 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
2607 }
2608
2609 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
2610 extern void JDK_Version_init();
2611
2612 // Preinitialize version info.
2613 VM_Version::early_initialize();
2614
2615 // Check version
2616 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
2617
2618 // Initialize library-based TLS
2619 ThreadLocalStorage::init();
2620
2621 // Initialize the output stream module
2622 ostream_init();
2623
2624 // Process java launcher properties.
2625 Arguments::process_sun_java_launcher_properties(args);
2626
2627 // Initialize the os module
2628 os::init();
2629
2630 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
2631
2632 // Record VM creation timing statistics
2633 TraceVmCreationTime create_vm_timer;
2634 create_vm_timer.start();
2635
2636 // Initialize system properties.
2637 Arguments::init_system_properties();
2638
2639 // So that JDK version can be used as a discriminator when parsing arguments
2640 JDK_Version_init();
2641
2642 // Update/Initialize System properties after JDK version number is known
2643 Arguments::init_version_specific_system_properties();
2644
2645 // Make sure to initialize log configuration *before* parsing arguments
2646 LogConfiguration::initialize(create_vm_timer.begin_time());
2647
2648 // Parse arguments
2649 // Note: this internally calls os::init_container_support()
2650 jint parse_result = Arguments::parse(args);
2651 if (parse_result != JNI_OK) return parse_result;
2652
2653 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
2654 MemTracker::initialize();
2655
2656 os::init_before_ergo();
2657
2658 jint ergo_result = Arguments::apply_ergo();
2659 if (ergo_result != JNI_OK) return ergo_result;
2660
2661 // Final check of all ranges after ergonomics which may change values.
2662 if (!JVMFlagLimit::check_all_ranges()) {
2663 return JNI_EINVAL;
2664 }
2665
2666 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
2667 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
2668 if (!constraint_result) {
2669 return JNI_EINVAL;
2670 }
2671
2672 if (PauseAtStartup) {
2673 os::pause();
2674 }
2675
2676 HOTSPOT_VM_INIT_BEGIN();
2677
2678 // Timing (must come after argument parsing)
2679 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
2680
2681 // Initialize the os module after parsing the args
2682 jint os_init_2_result = os::init_2();
2683 if (os_init_2_result != JNI_OK) return os_init_2_result;
2684
2685 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
2686 // Initialize assert poison page mechanism.
2687 if (ShowRegistersOnAssert) {
2688 initialize_assert_poison();
2689 }
2690 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
2691
2692 SafepointMechanism::initialize();
2693
2694 jint adjust_after_os_result = Arguments::adjust_after_os();
2695 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
2696
2697 // Initialize output stream logging
2698 ostream_init_log();
2699
2700 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
2701 // Must be before create_vm_init_agents()
2702 if (Arguments::init_libraries_at_startup()) {
2703 convert_vm_init_libraries_to_agents();
2704 }
2705
2706 // Launch -agentlib/-agentpath and converted -Xrun agents
2707 if (Arguments::init_agents_at_startup()) {
2708 create_vm_init_agents();
2709 }
2710
2711 // Initialize Threads state
2712 _number_of_threads = 0;
2713 _number_of_non_daemon_threads = 0;
2714
2715 // Initialize global data structures and create system classes in heap
2716 vm_init_globals();
2717
2718 #if INCLUDE_JVMCI
2719 if (JVMCICounterSize > 0) {
2720 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
2721 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
2722 } else {
2723 JavaThread::_jvmci_old_thread_counters = NULL;
2724 }
2725 #endif // INCLUDE_JVMCI
2726
2727 // Initialize OopStorage for threadObj
2728 _thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
2729
2730 // Attach the main thread to this os thread
2731 JavaThread* main_thread = new JavaThread();
2732 main_thread->set_thread_state(_thread_in_vm);
2733 main_thread->initialize_thread_current();
2734 // must do this before set_active_handles
2735 main_thread->record_stack_base_and_size();
2736 main_thread->register_thread_stack_with_NMT();
2737 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
2738 MACOS_AARCH64_ONLY(main_thread->init_wx());
2739
2740 if (!main_thread->set_as_starting_thread()) {
2741 vm_shutdown_during_initialization(
2742 "Failed necessary internal allocation. Out of swap space");
2743 main_thread->smr_delete();
2744 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2745 return JNI_ENOMEM;
2746 }
2747
2748 // Enable guard page *after* os::create_main_thread(), otherwise it would
2749 // crash Linux VM, see notes in os_linux.cpp.
2750 main_thread->stack_overflow_state()->create_stack_guard_pages();
2751
2752 // Initialize Java-Level synchronization subsystem
2753 ObjectMonitor::Initialize();
2754 ObjectSynchronizer::initialize();
2755
2756 // Initialize global modules
2757 jint status = init_globals();
2758 if (status != JNI_OK) {
2759 main_thread->smr_delete();
2760 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
2761 return status;
2762 }
2763
2764 JFR_ONLY(Jfr::on_create_vm_1();)
2765
2766 // Should be done after the heap is fully created
2767 main_thread->cache_global_variables();
2768
2769 { MutexLocker mu(Threads_lock);
2770 Threads::add(main_thread);
2771 }
2772
2773 // Any JVMTI raw monitors entered in onload will transition into
2774 // real raw monitor. VM is setup enough here for raw monitor enter.
2775 JvmtiExport::transition_pending_onload_raw_monitors();
2776
2777 // Create the VMThread
2778 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
2779
2780 VMThread::create();
2781 VMThread* vmthread = VMThread::vm_thread();
2782
2783 if (!os::create_thread(vmthread, os::vm_thread)) {
2784 vm_exit_during_initialization("Cannot create VM thread. "
2785 "Out of system resources.");
2786 }
2787
2788 // Wait for the VM thread to become ready, and VMThread::run to initialize
2789 // Monitors can have spurious returns, must always check another state flag
2790 {
2791 MonitorLocker ml(Notify_lock);
2792 os::start_thread(vmthread);
2793 while (!vmthread->is_running()) {
2794 ml.wait();
2795 }
2796 }
2797 }
2798
2799 assert(Universe::is_fully_initialized(), "not initialized");
2800 if (VerifyDuringStartup) {
2801 // Make sure we're starting with a clean slate.
2802 VM_Verify verify_op;
2803 VMThread::execute(&verify_op);
2804 }
2805
2806 // We need this to update the java.vm.info property in case any flags used
2807 // to initially define it have been changed. This is needed for both CDS
2808 // since UseSharedSpaces may be changed after java.vm.info
2809 // is initially computed. See Abstract_VM_Version::vm_info_string().
2810 // This update must happen before we initialize the java classes, but
2811 // after any initialization logic that might modify the flags.
2812 Arguments::update_vm_info_property(VM_Version::vm_info_string());
2813
2814 JavaThread* THREAD = JavaThread::current(); // For exception macros.
2815 HandleMark hm(THREAD);
2816
2817 // Always call even when there are not JVMTI environments yet, since environments
2818 // may be attached late and JVMTI must track phases of VM execution
2819 JvmtiExport::enter_early_start_phase();
2820
2821 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
2822 JvmtiExport::post_early_vm_start();
2823
2824 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
2825
2826 quicken_jni_functions();
2827
2828 // No more stub generation allowed after that point.
2829 StubCodeDesc::freeze();
2830
2831 // Set flag that basic initialization has completed. Used by exceptions and various
2832 // debug stuff, that does not work until all basic classes have been initialized.
2833 set_init_completed();
2834
2835 LogConfiguration::post_initialize();
2836 Metaspace::post_initialize();
2837
2838 HOTSPOT_VM_INIT_END();
2839
2840 // record VM initialization completion time
2841 #if INCLUDE_MANAGEMENT
2842 Management::record_vm_init_completed();
2843 #endif // INCLUDE_MANAGEMENT
2844
2845 // Signal Dispatcher needs to be started before VMInit event is posted
2846 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
2847
2848 // Start Attach Listener if +StartAttachListener or it can't be started lazily
2849 if (!DisableAttachMechanism) {
2850 AttachListener::vm_start();
2851 if (StartAttachListener || AttachListener::init_at_startup()) {
2852 AttachListener::init();
2853 }
2854 }
2855
2856 // Launch -Xrun agents
2857 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
2858 // back-end can launch with -Xdebug -Xrunjdwp.
2859 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
2860 create_vm_init_libraries();
2861 }
2862
2863 Chunk::start_chunk_pool_cleaner_task();
2864
2865 // Start the service thread
2866 // The service thread enqueues JVMTI deferred events and does various hashtable
2867 // and other cleanups. Needs to start before the compilers start posting events.
2868 ServiceThread::initialize();
2869
2870 // Start the monitor deflation thread:
2871 MonitorDeflationThread::initialize();
2872
2873 // Start heap object statistics sampling
2874 HeapObjectStatistics::initialize();
2875
2876 // initialize compiler(s)
2877 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
2878 #if INCLUDE_JVMCI
2879 bool force_JVMCI_intialization = false;
2880 if (EnableJVMCI) {
2881 // Initialize JVMCI eagerly when it is explicitly requested.
2882 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
2883 force_JVMCI_intialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
2884
2885 if (!force_JVMCI_intialization) {
2886 // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking
2887 // compilations via JVMCI will not actually block until JVMCI is initialized.
2888 force_JVMCI_intialization = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation);
2889 }
2890 }
2891 #endif
2892 CompileBroker::compilation_init_phase1(CHECK_JNI_ERR);
2893 // Postpone completion of compiler initialization to after JVMCI
2894 // is initialized to avoid timeouts of blocking compilations.
2895 if (JVMCI_ONLY(!force_JVMCI_intialization) NOT_JVMCI(true)) {
2896 CompileBroker::compilation_init_phase2();
2897 }
2898 #endif
2899
2900 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
2901 // It is done after compilers are initialized, because otherwise compilations of
2902 // signature polymorphic MH intrinsics can be missed
2903 // (see SystemDictionary::find_method_handle_intrinsic).
2904 initialize_jsr292_core_classes(CHECK_JNI_ERR);
2905
2906 // This will initialize the module system. Only java.base classes can be
2907 // loaded until phase 2 completes
2908 call_initPhase2(CHECK_JNI_ERR);
2909
2910 JFR_ONLY(Jfr::on_create_vm_2();)
2911
2912 // Always call even when there are not JVMTI environments yet, since environments
2913 // may be attached late and JVMTI must track phases of VM execution
2914 JvmtiExport::enter_start_phase();
2915
2916 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
2917 JvmtiExport::post_vm_start();
2918
2919 // Final system initialization including security manager and system class loader
2920 call_initPhase3(CHECK_JNI_ERR);
2921
2922 // cache the system and platform class loaders
2923 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
2924
2925 #if INCLUDE_CDS
2926 // capture the module path info from the ModuleEntryTable
2927 ClassLoader::initialize_module_path(THREAD);
2928 if (HAS_PENDING_EXCEPTION) {
2929 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
2930 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
2931 }
2932 #endif
2933
2934 #if INCLUDE_JVMCI
2935 if (force_JVMCI_intialization) {
2936 JVMCI::initialize_compiler(CHECK_JNI_ERR);
2937 CompileBroker::compilation_init_phase2();
2938 }
2939 #endif
2940
2941 // Always call even when there are not JVMTI environments yet, since environments
2942 // may be attached late and JVMTI must track phases of VM execution
2943 JvmtiExport::enter_live_phase();
2944
2945 // Make perfmemory accessible
2946 PerfMemory::set_accessible(true);
2947
2948 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
2949 JvmtiExport::post_vm_initialized();
2950
2951 JFR_ONLY(Jfr::on_create_vm_3();)
2952
2953 #if INCLUDE_MANAGEMENT
2954 Management::initialize(THREAD);
2955
2956 if (HAS_PENDING_EXCEPTION) {
2957 // management agent fails to start possibly due to
2958 // configuration problem and is responsible for printing
2959 // stack trace if appropriate. Simply exit VM.
2960 vm_exit(1);
2961 }
2962 #endif // INCLUDE_MANAGEMENT
2963
2964 StatSampler::engage();
2965 if (CheckJNICalls) JniPeriodicChecker::engage();
2966
2967 #if INCLUDE_RTM_OPT
2968 RTMLockingCounters::init();
2969 #endif
2970
2971 call_postVMInitHook(THREAD);
2972 // The Java side of PostVMInitHook.run must deal with all
2973 // exceptions and provide means of diagnosis.
2974 if (HAS_PENDING_EXCEPTION) {
2975 CLEAR_PENDING_EXCEPTION;
2976 }
2977
2978 {
2979 MutexLocker ml(PeriodicTask_lock);
2980 // Make sure the WatcherThread can be started by WatcherThread::start()
2981 // or by dynamic enrollment.
2982 WatcherThread::make_startable();
2983 // Start up the WatcherThread if there are any periodic tasks
2984 // NOTE: All PeriodicTasks should be registered by now. If they
2985 // aren't, late joiners might appear to start slowly (we might
2986 // take a while to process their first tick).
2987 if (PeriodicTask::num_tasks() > 0) {
2988 WatcherThread::start();
2989 }
2990 }
2991
2992 create_vm_timer.end();
2993 #ifdef ASSERT
2994 _vm_complete = true;
2995 #endif
2996
2997 if (DumpSharedSpaces) {
2998 MetaspaceShared::preload_and_dump();
2999 ShouldNotReachHere();
3000 }
3001
3002 return JNI_OK;
3003 }
3004
3005 // type for the Agent_OnLoad and JVM_OnLoad entry points
3006 extern "C" {
3007 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3008 }
3009 // Find a command line agent library and return its entry point for
3010 // -agentlib: -agentpath: -Xrun
3011 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3012 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent,
3013 const char *on_load_symbols[],
3014 size_t num_symbol_entries) {
3015 OnLoadEntry_t on_load_entry = NULL;
3016 void *library = NULL;
3017
3018 if (!agent->valid()) {
3019 char buffer[JVM_MAXPATHLEN];
3020 char ebuf[1024] = "";
3021 const char *name = agent->name();
3022 const char *msg = "Could not find agent library ";
3023
3024 // First check to see if agent is statically linked into executable
3025 if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
3026 library = agent->os_lib();
3027 } else if (agent->is_absolute_path()) {
3028 library = os::dll_load(name, ebuf, sizeof ebuf);
3029 if (library == NULL) {
3030 const char *sub_msg = " in absolute path, with error: ";
3031 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3032 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3033 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3034 // If we can't find the agent, exit.
3035 vm_exit_during_initialization(buf, NULL);
3036 FREE_C_HEAP_ARRAY(char, buf);
3037 }
3038 } else {
3039 // Try to load the agent from the standard dll directory
3040 if (os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
3041 name)) {
3042 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3043 }
3044 if (library == NULL) { // Try the library path directory.
3045 if (os::dll_build_name(buffer, sizeof(buffer), name)) {
3046 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3047 }
3048 if (library == NULL) {
3049 const char *sub_msg = " on the library path, with error: ";
3050 const char *sub_msg2 = "\nModule java.instrument may be missing from runtime image.";
3051
3052 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) +
3053 strlen(ebuf) + strlen(sub_msg2) + 1;
3054 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3055 if (!agent->is_instrument_lib()) {
3056 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3057 } else {
3058 jio_snprintf(buf, len, "%s%s%s%s%s", msg, name, sub_msg, ebuf, sub_msg2);
3059 }
3060 // If we can't find the agent, exit.
3061 vm_exit_during_initialization(buf, NULL);
3062 FREE_C_HEAP_ARRAY(char, buf);
3063 }
3064 }
3065 }
3066 agent->set_os_lib(library);
3067 agent->set_valid();
3068 }
3069
3070 // Find the OnLoad function.
3071 on_load_entry =
3072 CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
3073 false,
3074 on_load_symbols,
3075 num_symbol_entries));
3076 return on_load_entry;
3077 }
3078
3079 // Find the JVM_OnLoad entry point
3080 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3081 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3082 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3083 }
3084
3085 // Find the Agent_OnLoad entry point
3086 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3087 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3088 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3089 }
3090
3091 // For backwards compatibility with -Xrun
3092 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3093 // treated like -agentpath:
3094 // Must be called before agent libraries are created
3095 void Threads::convert_vm_init_libraries_to_agents() {
3096 AgentLibrary* agent;
3097 AgentLibrary* next;
3098
3099 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3100 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3101 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3102
3103 // If there is an JVM_OnLoad function it will get called later,
3104 // otherwise see if there is an Agent_OnLoad
3105 if (on_load_entry == NULL) {
3106 on_load_entry = lookup_agent_on_load(agent);
3107 if (on_load_entry != NULL) {
3108 // switch it to the agent list -- so that Agent_OnLoad will be called,
3109 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3110 Arguments::convert_library_to_agent(agent);
3111 } else {
3112 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3113 }
3114 }
3115 }
3116 }
3117
3118 // Create agents for -agentlib: -agentpath: and converted -Xrun
3119 // Invokes Agent_OnLoad
3120 // Called very early -- before JavaThreads exist
3121 void Threads::create_vm_init_agents() {
3122 extern struct JavaVM_ main_vm;
3123 AgentLibrary* agent;
3124
3125 JvmtiExport::enter_onload_phase();
3126
3127 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3128 // CDS dumping does not support native JVMTI agent.
3129 // CDS dumping supports Java agent if the AllowArchivingWithJavaAgent diagnostic option is specified.
3130 if (Arguments::is_dumping_archive()) {
3131 if(!agent->is_instrument_lib()) {
3132 vm_exit_during_cds_dumping("CDS dumping does not support native JVMTI agent, name", agent->name());
3133 } else if (!AllowArchivingWithJavaAgent) {
3134 vm_exit_during_cds_dumping(
3135 "Must enable AllowArchivingWithJavaAgent in order to run Java agent during CDS dumping");
3136 }
3137 }
3138
3139 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3140
3141 if (on_load_entry != NULL) {
3142 // Invoke the Agent_OnLoad function
3143 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3144 if (err != JNI_OK) {
3145 vm_exit_during_initialization("agent library failed to init", agent->name());
3146 }
3147 } else {
3148 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3149 }
3150 }
3151
3152 JvmtiExport::enter_primordial_phase();
3153 }
3154
3155 extern "C" {
3156 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3157 }
3158
3159 void Threads::shutdown_vm_agents() {
3160 // Send any Agent_OnUnload notifications
3161 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3162 size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
3163 extern struct JavaVM_ main_vm;
3164 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3165
3166 // Find the Agent_OnUnload function.
3167 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3168 os::find_agent_function(agent,
3169 false,
3170 on_unload_symbols,
3171 num_symbol_entries));
3172
3173 // Invoke the Agent_OnUnload function
3174 if (unload_entry != NULL) {
3175 JavaThread* thread = JavaThread::current();
3176 ThreadToNativeFromVM ttn(thread);
3177 HandleMark hm(thread);
3178 (*unload_entry)(&main_vm);
3179 }
3180 }
3181 }
3182
3183 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3184 // Invokes JVM_OnLoad
3185 void Threads::create_vm_init_libraries() {
3186 extern struct JavaVM_ main_vm;
3187 AgentLibrary* agent;
3188
3189 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3190 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3191
3192 if (on_load_entry != NULL) {
3193 // Invoke the JVM_OnLoad function
3194 JavaThread* thread = JavaThread::current();
3195 ThreadToNativeFromVM ttn(thread);
3196 HandleMark hm(thread);
3197 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3198 if (err != JNI_OK) {
3199 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3200 }
3201 } else {
3202 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3203 }
3204 }
3205 }
3206
3207
3208 // Last thread running calls java.lang.Shutdown.shutdown()
3209 void JavaThread::invoke_shutdown_hooks() {
3210 HandleMark hm(this);
3211
3212 // We could get here with a pending exception, if so clear it now or
3213 // it will cause MetaspaceShared::link_shared_classes to
3214 // fail for dynamic dump.
3215 if (this->has_pending_exception()) {
3216 this->clear_pending_exception();
3217 }
3218
3219 #if INCLUDE_CDS
3220 // Link all classes for dynamic CDS dumping before vm exit.
3221 // Same operation is being done in JVM_BeforeHalt for handling the
3222 // case where the application calls System.exit().
3223 if (DynamicArchive::should_dump_at_vm_exit()) {
3224 DynamicArchive::prepare_for_dump_at_exit();
3225 }
3226 #endif
3227
3228 EXCEPTION_MARK;
3229 Klass* shutdown_klass =
3230 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3231 THREAD);
3232 if (shutdown_klass != NULL) {
3233 // SystemDictionary::resolve_or_null will return null if there was
3234 // an exception. If we cannot load the Shutdown class, just don't
3235 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3236 // won't be run. Note that if a shutdown hook was registered,
3237 // the Shutdown class would have already been loaded
3238 // (Runtime.addShutdownHook will load it).
3239 JavaValue result(T_VOID);
3240 JavaCalls::call_static(&result,
3241 shutdown_klass,
3242 vmSymbols::shutdown_name(),
3243 vmSymbols::void_method_signature(),
3244 THREAD);
3245 }
3246 CLEAR_PENDING_EXCEPTION;
3247 }
3248
3249 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3250 // the program falls off the end of main(). Another VM exit path is through
3251 // vm_exit() when the program calls System.exit() to return a value or when
3252 // there is a serious error in VM. The two shutdown paths are not exactly
3253 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3254 // and VM_Exit op at VM level.
3255 //
3256 // Shutdown sequence:
3257 // + Shutdown native memory tracking if it is on
3258 // + Wait until we are the last non-daemon thread to execute
3259 // <-- every thing is still working at this moment -->
3260 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3261 // shutdown hooks
3262 // + Call before_exit(), prepare for VM exit
3263 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3264 // currently the only user of this mechanism is File.deleteOnExit())
3265 // > stop StatSampler, watcher thread,
3266 // post thread end and vm death events to JVMTI,
3267 // stop signal thread
3268 // + Call JavaThread::exit(), it will:
3269 // > release JNI handle blocks, remove stack guard pages
3270 // > remove this thread from Threads list
3271 // <-- no more Java code from this thread after this point -->
3272 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3273 // the compiler threads at safepoint
3274 // <-- do not use anything that could get blocked by Safepoint -->
3275 // + Disable tracing at JNI/JVM barriers
3276 // + Set _vm_exited flag for threads that are still running native code
3277 // + Call exit_globals()
3278 // > deletes tty
3279 // > deletes PerfMemory resources
3280 // + Delete this thread
3281 // + Return to caller
3282
3283 void Threads::destroy_vm() {
3284 JavaThread* thread = JavaThread::current();
3285
3286 #ifdef ASSERT
3287 _vm_complete = false;
3288 #endif
3289 // Wait until we are the last non-daemon thread to execute
3290 {
3291 MonitorLocker nu(Threads_lock);
3292 while (Threads::number_of_non_daemon_threads() > 1)
3293 // This wait should make safepoint checks, wait without a timeout.
3294 nu.wait(0);
3295 }
3296
3297 EventShutdown e;
3298 if (e.should_commit()) {
3299 e.set_reason("No remaining non-daemon Java threads");
3300 e.commit();
3301 }
3302
3303 // Hang forever on exit if we are reporting an error.
3304 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
3305 os::infinite_sleep();
3306 }
3307 os::wait_for_keypress_at_exit();
3308
3309 // run Java level shutdown hooks
3310 thread->invoke_shutdown_hooks();
3311
3312 before_exit(thread);
3313
3314 thread->exit(true);
3315
3316 // We are no longer on the main thread list but could still be in a
3317 // secondary list where another thread may try to interact with us.
3318 // So wait until all such interactions are complete before we bring
3319 // the VM to the termination safepoint. Normally this would be done
3320 // using thread->smr_delete() below where we delete the thread, but
3321 // we can't call that after the termination safepoint is active as
3322 // we will deadlock on the Threads_lock. Once all interactions are
3323 // complete it is safe to directly delete the thread at any time.
3324 ThreadsSMRSupport::wait_until_not_protected(thread);
3325
3326 HeapObjectStatistics::shutdown();
3327
3328 // Stop VM thread.
3329 {
3330 // 4945125 The vm thread comes to a safepoint during exit.
3331 // GC vm_operations can get caught at the safepoint, and the
3332 // heap is unparseable if they are caught. Grab the Heap_lock
3333 // to prevent this. The GC vm_operations will not be able to
3334 // queue until after the vm thread is dead. After this point,
3335 // we'll never emerge out of the safepoint before the VM exits.
3336 // Assert that the thread is terminated so that acquiring the
3337 // Heap_lock doesn't cause the terminated thread to participate in
3338 // the safepoint protocol.
3339
3340 assert(thread->is_terminated(), "must be terminated here");
3341 MutexLocker ml(Heap_lock);
3342
3343 VMThread::wait_for_vm_thread_exit();
3344 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
3345 VMThread::destroy();
3346 }
3347
3348 // Now, all Java threads are gone except daemon threads. Daemon threads
3349 // running Java code or in VM are stopped by the Safepoint. However,
3350 // daemon threads executing native code are still running. But they
3351 // will be stopped at native=>Java/VM barriers. Note that we can't
3352 // simply kill or suspend them, as it is inherently deadlock-prone.
3353
3354 VM_Exit::set_vm_exited();
3355
3356 // Clean up ideal graph printers after the VMThread has started
3357 // the final safepoint which will block all the Compiler threads.
3358 // Note that this Thread has already logically exited so the
3359 // clean_up() function's use of a JavaThreadIteratorWithHandle
3360 // would be a problem except set_vm_exited() has remembered the
3361 // shutdown thread which is granted a policy exception.
3362 #if defined(COMPILER2) && !defined(PRODUCT)
3363 IdealGraphPrinter::clean_up();
3364 #endif
3365
3366 notify_vm_shutdown();
3367
3368 // exit_globals() will delete tty
3369 exit_globals();
3370
3371 // Deleting the shutdown thread here is safe. See comment on
3372 // wait_until_not_protected() above.
3373 delete thread;
3374
3375 #if INCLUDE_JVMCI
3376 if (JVMCICounterSize > 0) {
3377 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
3378 }
3379 #endif
3380
3381 LogConfiguration::finalize();
3382 }
3383
3384
3385 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
3386 if (version == JNI_VERSION_1_1) return JNI_TRUE;
3387 return is_supported_jni_version(version);
3388 }
3389
3390
3391 jboolean Threads::is_supported_jni_version(jint version) {
3392 if (version == JNI_VERSION_1_2) return JNI_TRUE;
3393 if (version == JNI_VERSION_1_4) return JNI_TRUE;
3394 if (version == JNI_VERSION_1_6) return JNI_TRUE;
3395 if (version == JNI_VERSION_1_8) return JNI_TRUE;
3396 if (version == JNI_VERSION_9) return JNI_TRUE;
3397 if (version == JNI_VERSION_10) return JNI_TRUE;
3398 return JNI_FALSE;
3399 }
3400
3401
3402 void Threads::add(JavaThread* p, bool force_daemon) {
3403 // The threads lock must be owned at this point
3404 assert(Threads_lock->owned_by_self(), "must have threads lock");
3405
3406 BarrierSet::barrier_set()->on_thread_attach(p);
3407
3408 // Once a JavaThread is added to the Threads list, smr_delete() has
3409 // to be used to delete it. Otherwise we can just delete it directly.
3410 p->set_on_thread_list();
3411
3412 _number_of_threads++;
3413 oop threadObj = p->threadObj();
3414 bool daemon = true;
3415 // Bootstrapping problem: threadObj can be null for initial
3416 // JavaThread (or for threads attached via JNI)
3417 if ((!force_daemon) && !is_daemon((threadObj))) {
3418 _number_of_non_daemon_threads++;
3419 daemon = false;
3420 }
3421
3422 ThreadService::add_thread(p, daemon);
3423
3424 // Maintain fast thread list
3425 ThreadsSMRSupport::add_thread(p);
3426
3427 // Increase the ObjectMonitor ceiling for the new thread.
3428 ObjectSynchronizer::inc_in_use_list_ceiling();
3429
3430 // Possible GC point.
3431 Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
3432
3433 // Make new thread known to active EscapeBarrier
3434 EscapeBarrier::thread_added(p);
3435 }
3436
3437 void Threads::remove(JavaThread* p, bool is_daemon) {
3438 // Extra scope needed for Thread_lock, so we can check
3439 // that we do not remove thread without safepoint code notice
3440 { MonitorLocker ml(Threads_lock);
3441
3442 // BarrierSet state must be destroyed after the last thread transition
3443 // before the thread terminates. Thread transitions result in calls to
3444 // StackWatermarkSet::on_safepoint(), which performs GC processing,
3445 // requiring the GC state to be alive.
3446 BarrierSet::barrier_set()->on_thread_detach(p);
3447
3448 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
3449
3450 // Maintain fast thread list
3451 ThreadsSMRSupport::remove_thread(p);
3452
3453 _number_of_threads--;
3454 if (!is_daemon) {
3455 _number_of_non_daemon_threads--;
3456
3457 // Only one thread left, do a notify on the Threads_lock so a thread waiting
3458 // on destroy_vm will wake up.
3459 if (number_of_non_daemon_threads() == 1) {
3460 ml.notify_all();
3461 }
3462 }
3463 ThreadService::remove_thread(p, is_daemon);
3464
3465 // Make sure that safepoint code disregard this thread. This is needed since
3466 // the thread might mess around with locks after this point. This can cause it
3467 // to do callbacks into the safepoint code. However, the safepoint code is not aware
3468 // of this thread since it is removed from the queue.
3469 p->set_terminated(JavaThread::_thread_terminated);
3470
3471 // Notify threads waiting in EscapeBarriers
3472 EscapeBarrier::thread_removed(p);
3473 } // unlock Threads_lock
3474
3475 // Reduce the ObjectMonitor ceiling for the exiting thread.
3476 ObjectSynchronizer::dec_in_use_list_ceiling();
3477
3478 // Since Events::log uses a lock, we grab it outside the Threads_lock
3479 Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
3480 }
3481
3482 // Operations on the Threads list for GC. These are not explicitly locked,
3483 // but the garbage collector must provide a safe context for them to run.
3484 // In particular, these things should never be called when the Threads_lock
3485 // is held by some other thread. (Note: the Safepoint abstraction also
3486 // uses the Threads_lock to guarantee this property. It also makes sure that
3487 // all threads gets blocked when exiting or starting).
3488
3489 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
3490 ALL_JAVA_THREADS(p) {
3491 p->oops_do(f, cf);
3492 }
3493 VMThread::vm_thread()->oops_do(f, cf);
3494 }
3495
3496 void Threads::change_thread_claim_token() {
3497 if (++_thread_claim_token == 0) {
3498 // On overflow of the token counter, there is a risk of future
3499 // collisions between a new global token value and a stale token
3500 // for a thread, because not all iterations visit all threads.
3501 // (Though it's pretty much a theoretical concern for non-trivial
3502 // token counter sizes.) To deal with the possibility, reset all
3503 // the thread tokens to zero on global token overflow.
3504 struct ResetClaims : public ThreadClosure {
3505 virtual void do_thread(Thread* t) {
3506 t->claim_threads_do(false, 0);
3507 }
3508 } reset_claims;
3509 Threads::threads_do(&reset_claims);
3510 // On overflow, update the global token to non-zero, to
3511 // avoid the special "never claimed" initial thread value.
3512 _thread_claim_token = 1;
3513 }
3514 }
3515
3516 #ifdef ASSERT
3517 void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
3518 const uintx token = t->threads_do_token();
3519 assert(token == expected,
3520 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
3521 UINTX_FORMAT, kind, p2i(t), token, expected);
3522 }
3523
3524 void Threads::assert_all_threads_claimed() {
3525 ALL_JAVA_THREADS(p) {
3526 assert_thread_claimed("Thread", p, _thread_claim_token);
3527 }
3528 assert_thread_claimed("VMThread", VMThread::vm_thread(), _thread_claim_token);
3529 }
3530 #endif // ASSERT
3531
3532 class ParallelOopsDoThreadClosure : public ThreadClosure {
3533 private:
3534 OopClosure* _f;
3535 CodeBlobClosure* _cf;
3536 public:
3537 ParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf) : _f(f), _cf(cf) {}
3538 void do_thread(Thread* t) {
3539 t->oops_do(_f, _cf);
3540 }
3541 };
3542
3543 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) {
3544 ParallelOopsDoThreadClosure tc(f, cf);
3545 possibly_parallel_threads_do(is_par, &tc);
3546 }
3547
3548 void Threads::metadata_do(MetadataClosure* f) {
3549 ALL_JAVA_THREADS(p) {
3550 p->metadata_do(f);
3551 }
3552 }
3553
3554 class ThreadHandlesClosure : public ThreadClosure {
3555 void (*_f)(Metadata*);
3556 public:
3557 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
3558 virtual void do_thread(Thread* thread) {
3559 thread->metadata_handles_do(_f);
3560 }
3561 };
3562
3563 void Threads::metadata_handles_do(void f(Metadata*)) {
3564 // Only walk the Handles in Thread.
3565 ThreadHandlesClosure handles_closure(f);
3566 threads_do(&handles_closure);
3567 }
3568
3569 // Get count Java threads that are waiting to enter the specified monitor.
3570 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
3571 int count,
3572 address monitor) {
3573 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
3574
3575 int i = 0;
3576 for (JavaThread* p : *t_list) {
3577 if (!p->can_call_java()) continue;
3578
3579 // The first stage of async deflation does not affect any field
3580 // used by this comparison so the ObjectMonitor* is usable here.
3581 address pending = (address)p->current_pending_monitor();
3582 if (pending == monitor) { // found a match
3583 if (i < count) result->append(p); // save the first count matches
3584 i++;
3585 }
3586 }
3587
3588 return result;
3589 }
3590
3591
3592 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
3593 address owner) {
3594 // NULL owner means not locked so we can skip the search
3595 if (owner == NULL) return NULL;
3596
3597 for (JavaThread* p : *t_list) {
3598 // first, see if owner is the address of a Java thread
3599 if (owner == (address)p) return p;
3600 }
3601
3602 // Cannot assert on lack of success here since this function may be
3603 // used by code that is trying to report useful problem information
3604 // like deadlock detection.
3605 if (UseHeavyMonitors) return NULL;
3606
3607 // If we didn't find a matching Java thread and we didn't force use of
3608 // heavyweight monitors, then the owner is the stack address of the
3609 // Lock Word in the owning Java thread's stack.
3610 //
3611 JavaThread* the_owner = NULL;
3612 for (JavaThread* q : *t_list) {
3613 if (q->is_lock_owned(owner)) {
3614 the_owner = q;
3615 break;
3616 }
3617 }
3618
3619 // cannot assert on lack of success here; see above comment
3620 return the_owner;
3621 }
3622
3623 class PrintOnClosure : public ThreadClosure {
3624 private:
3625 outputStream* _st;
3626
3627 public:
3628 PrintOnClosure(outputStream* st) :
3629 _st(st) {}
3630
3631 virtual void do_thread(Thread* thread) {
3632 if (thread != NULL) {
3633 thread->print_on(_st);
3634 _st->cr();
3635 }
3636 }
3637 };
3638
3639 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
3640 void Threads::print_on(outputStream* st, bool print_stacks,
3641 bool internal_format, bool print_concurrent_locks,
3642 bool print_extended_info) {
3643 char buf[32];
3644 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
3645
3646 st->print_cr("Full thread dump %s (%s %s):",
3647 VM_Version::vm_name(),
3648 VM_Version::vm_release(),
3649 VM_Version::vm_info_string());
3650 st->cr();
3651
3652 #if INCLUDE_SERVICES
3653 // Dump concurrent locks
3654 ConcurrentLocksDump concurrent_locks;
3655 if (print_concurrent_locks) {
3656 concurrent_locks.dump_at_safepoint();
3657 }
3658 #endif // INCLUDE_SERVICES
3659
3660 ThreadsSMRSupport::print_info_on(st);
3661 st->cr();
3662
3663 ALL_JAVA_THREADS(p) {
3664 ResourceMark rm;
3665 p->print_on(st, print_extended_info);
3666 if (print_stacks) {
3667 if (internal_format) {
3668 p->trace_stack();
3669 } else {
3670 p->print_stack_on(st);
3671 }
3672 }
3673 st->cr();
3674 #if INCLUDE_SERVICES
3675 if (print_concurrent_locks) {
3676 concurrent_locks.print_locks_on(p, st);
3677 }
3678 #endif // INCLUDE_SERVICES
3679 }
3680
3681 PrintOnClosure cl(st);
3682 cl.do_thread(VMThread::vm_thread());
3683 Universe::heap()->gc_threads_do(&cl);
3684 if (StringDedup::is_enabled()) {
3685 StringDedup::threads_do(&cl);
3686 }
3687 cl.do_thread(WatcherThread::watcher_thread());
3688 cl.do_thread(AsyncLogWriter::instance());
3689
3690 st->flush();
3691 }
3692
3693 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
3694 int buflen, bool* found_current) {
3695 if (this_thread != NULL) {
3696 bool is_current = (current == this_thread);
3697 *found_current = *found_current || is_current;
3698 st->print("%s", is_current ? "=>" : " ");
3699
3700 st->print(PTR_FORMAT, p2i(this_thread));
3701 st->print(" ");
3702 this_thread->print_on_error(st, buf, buflen);
3703 st->cr();
3704 }
3705 }
3706
3707 class PrintOnErrorClosure : public ThreadClosure {
3708 outputStream* _st;
3709 Thread* _current;
3710 char* _buf;
3711 int _buflen;
3712 bool* _found_current;
3713 public:
3714 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
3715 int buflen, bool* found_current) :
3716 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
3717
3718 virtual void do_thread(Thread* thread) {
3719 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
3720 }
3721 };
3722
3723 // Threads::print_on_error() is called by fatal error handler. It's possible
3724 // that VM is not at safepoint and/or current thread is inside signal handler.
3725 // Don't print stack trace, as the stack may not be walkable. Don't allocate
3726 // memory (even in resource area), it might deadlock the error handler.
3727 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
3728 int buflen) {
3729 ThreadsSMRSupport::print_info_on(st);
3730 st->cr();
3731
3732 bool found_current = false;
3733 st->print_cr("Java Threads: ( => current thread )");
3734 ALL_JAVA_THREADS(thread) {
3735 print_on_error(thread, st, current, buf, buflen, &found_current);
3736 }
3737 st->cr();
3738
3739 st->print_cr("Other Threads:");
3740 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
3741 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
3742 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
3743
3744 if (Universe::heap() != NULL) {
3745 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
3746 Universe::heap()->gc_threads_do(&print_closure);
3747 }
3748
3749 if (StringDedup::is_enabled()) {
3750 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
3751 StringDedup::threads_do(&print_closure);
3752 }
3753
3754 if (!found_current) {
3755 st->cr();
3756 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
3757 current->print_on_error(st, buf, buflen);
3758 st->cr();
3759 }
3760 st->cr();
3761
3762 st->print_cr("Threads with active compile tasks:");
3763 print_threads_compiling(st, buf, buflen);
3764 }
3765
3766 void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
3767 ALL_JAVA_THREADS(thread) {
3768 if (thread->is_Compiler_thread()) {
3769 CompilerThread* ct = (CompilerThread*) thread;
3770
3771 // Keep task in local variable for NULL check.
3772 // ct->_task might be set to NULL by concurring compiler thread
3773 // because it completed the compilation. The task is never freed,
3774 // though, just returned to a free list.
3775 CompileTask* task = ct->task();
3776 if (task != NULL) {
3777 thread->print_name_on_error(st, buf, buflen);
3778 st->print(" ");
3779 task->print(st, NULL, short_form, true);
3780 }
3781 }
3782 }
3783 }
3784
3785
3786 // Ad-hoc mutual exclusion primitives: SpinLock
3787 //
3788 // We employ SpinLocks _only for low-contention, fixed-length
3789 // short-duration critical sections where we're concerned
3790 // about native mutex_t or HotSpot Mutex:: latency.
3791 //
3792 // TODO-FIXME: ListLock should be of type SpinLock.
3793 // We should make this a 1st-class type, integrated into the lock
3794 // hierarchy as leaf-locks. Critically, the SpinLock structure
3795 // should have sufficient padding to avoid false-sharing and excessive
3796 // cache-coherency traffic.
3797
3798
3799 typedef volatile int SpinLockT;
3800
3801 void Thread::SpinAcquire(volatile int * adr, const char * LockName) {
3802 if (Atomic::cmpxchg(adr, 0, 1) == 0) {
3803 return; // normal fast-path return
3804 }
3805
3806 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
3807 int ctr = 0;
3808 int Yields = 0;
3809 for (;;) {
3810 while (*adr != 0) {
3811 ++ctr;
3812 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
3813 if (Yields > 5) {
3814 os::naked_short_sleep(1);
3815 } else {
3816 os::naked_yield();
3817 ++Yields;
3818 }
3819 } else {
3820 SpinPause();
3821 }
3822 }
3823 if (Atomic::cmpxchg(adr, 0, 1) == 0) return;
3824 }
3825 }
3826
3827 void Thread::SpinRelease(volatile int * adr) {
3828 assert(*adr != 0, "invariant");
3829 OrderAccess::fence(); // guarantee at least release consistency.
3830 // Roach-motel semantics.
3831 // It's safe if subsequent LDs and STs float "up" into the critical section,
3832 // but prior LDs and STs within the critical section can't be allowed
3833 // to reorder or float past the ST that releases the lock.
3834 // Loads and stores in the critical section - which appear in program
3835 // order before the store that releases the lock - must also appear
3836 // before the store that releases the lock in memory visibility order.
3837 // Conceptually we need a #loadstore|#storestore "release" MEMBAR before
3838 // the ST of 0 into the lock-word which releases the lock, so fence
3839 // more than covers this on all platforms.
3840 *adr = 0;
3841 }
3842
3843
3844 void Threads::verify() {
3845 ALL_JAVA_THREADS(p) {
3846 p->verify();
3847 }
3848 VMThread* thread = VMThread::vm_thread();
3849 if (thread != NULL) thread->verify();
3850 }
3851
3852 #ifndef PRODUCT
3853 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
3854 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
3855 }
3856 #endif
3857
3858 // Helper function to create the java.lang.Thread object for a
3859 // VM-internal thread. The thread will have the given name, be
3860 // part of the System ThreadGroup and if is_visible is true will be
3861 // discoverable via the system ThreadGroup.
3862 Handle JavaThread::create_system_thread_object(const char* name,
3863 bool is_visible, TRAPS) {
3864 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
3865
3866 // Initialize thread_oop to put it into the system threadGroup.
3867 // This is done by calling the Thread(ThreadGroup tg, String name)
3868 // constructor, which adds the new thread to the group as an unstarted
3869 // thread.
3870 Handle thread_group(THREAD, Universe::system_thread_group());
3871 Handle thread_oop =
3872 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
3873 vmSymbols::threadgroup_string_void_signature(),
3874 thread_group,
3875 string,
3876 CHECK_NH);
3877
3878 // If the Thread is intended to be visible then we have to mimic what
3879 // Thread.start() would do, by adding it to its ThreadGroup: tg.add(t).
3880 if (is_visible) {
3881 Klass* group = vmClasses::ThreadGroup_klass();
3882 JavaValue result(T_VOID);
3883 JavaCalls::call_special(&result,
3884 thread_group,
3885 group,
3886 vmSymbols::add_method_name(),
3887 vmSymbols::thread_void_signature(),
3888 thread_oop,
3889 CHECK_NH);
3890 }
3891
3892 return thread_oop;
3893 }
3894
3895 // Starts the target JavaThread as a daemon of the given priority, and
3896 // bound to the given java.lang.Thread instance.
3897 // The Threads_lock is held for the duration.
3898 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
3899 Handle thread_oop, ThreadPriority prio) {
3900
3901 assert(target->osthread() != NULL, "target thread is not properly initialized");
3902
3903 MutexLocker mu(current, Threads_lock);
3904
3905 // Initialize the fields of the thread_oop first.
3906
3907 java_lang_Thread::set_thread(thread_oop(), target); // isAlive == true now
3908
3909 if (prio != NoPriority) {
3910 java_lang_Thread::set_priority(thread_oop(), prio);
3911 // Note: we don't call os::set_priority here. Possibly we should,
3912 // else all threads should call it themselves when they first run.
3913 }
3914
3915 java_lang_Thread::set_daemon(thread_oop());
3916
3917 // Now bind the thread_oop to the target JavaThread.
3918 target->set_threadObj(thread_oop());
3919
3920 Threads::add(target); // target is now visible for safepoint/handshake
3921 Thread::start(target);
3922 }
3923
3924 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
3925 // At this point it may be possible that no osthread was created for the
3926 // JavaThread due to lack of resources. However, since this must work
3927 // for critical system threads just check and abort if this fails.
3928 if (thread->osthread() == nullptr) {
3929 // This isn't really an OOM condition, but historically this is what
3930 // we report.
3931 vm_exit_during_initialization("java.lang.OutOfMemoryError",
3932 os::native_thread_creation_failed_msg());
3933 }
3934 }