1 /*
2 * Copyright (c) 1997, 2023, 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 "cds/dynamicArchive.hpp"
28 #include "ci/ciEnv.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/javaThreadStatus.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "classfile/vmClasses.hpp"
33 #include "classfile/vmSymbols.hpp"
34 #include "code/codeCache.hpp"
35 #include "code/scopeDesc.hpp"
36 #include "compiler/compileTask.hpp"
37 #include "compiler/compilerThread.hpp"
38 #include "gc/shared/oopStorage.hpp"
39 #include "gc/shared/oopStorageSet.hpp"
40 #include "gc/shared/tlab_globals.hpp"
41 #include "jfr/jfrEvents.hpp"
42 #include "jvm.h"
43 #include "jvmtifiles/jvmtiEnv.hpp"
44 #include "logging/log.hpp"
45 #include "logging/logAsyncWriter.hpp"
46 #include "logging/logStream.hpp"
47 #include "memory/allocation.inline.hpp"
48 #include "memory/iterator.hpp"
49 #include "memory/universe.hpp"
50 #include "oops/access.inline.hpp"
51 #include "oops/instanceKlass.hpp"
52 #include "oops/klass.inline.hpp"
53 #include "oops/oop.inline.hpp"
54 #include "oops/oopHandle.inline.hpp"
55 #include "oops/verifyOopClosure.hpp"
56 #include "prims/jvm_misc.hpp"
57 #include "prims/jvmtiDeferredUpdates.hpp"
58 #include "prims/jvmtiExport.hpp"
59 #include "prims/jvmtiThreadState.inline.hpp"
60 #include "runtime/atomic.hpp"
61 #include "runtime/continuation.hpp"
62 #include "runtime/continuationEntry.inline.hpp"
63 #include "runtime/continuationHelper.inline.hpp"
64 #include "runtime/deoptimization.hpp"
65 #include "runtime/frame.inline.hpp"
66 #include "runtime/handles.inline.hpp"
67 #include "runtime/handshake.hpp"
68 #include "runtime/interfaceSupport.inline.hpp"
69 #include "runtime/java.hpp"
70 #include "runtime/javaCalls.hpp"
71 #include "runtime/javaThread.inline.hpp"
72 #include "runtime/jniHandles.inline.hpp"
73 #include "runtime/mutexLocker.hpp"
74 #include "runtime/orderAccess.hpp"
75 #include "runtime/osThread.hpp"
76 #include "runtime/safepoint.hpp"
77 #include "runtime/safepointMechanism.inline.hpp"
78 #include "runtime/safepointVerifiers.hpp"
79 #include "runtime/serviceThread.hpp"
80 #include "runtime/stackFrameStream.inline.hpp"
81 #include "runtime/stackWatermarkSet.hpp"
82 #include "runtime/synchronizer.hpp"
83 #include "runtime/threadCritical.hpp"
84 #include "runtime/threadSMR.inline.hpp"
85 #include "runtime/threadStatisticalInfo.hpp"
86 #include "runtime/threadWXSetters.inline.hpp"
87 #include "runtime/timer.hpp"
88 #include "runtime/timerTrace.hpp"
89 #include "runtime/vframe.inline.hpp"
90 #include "runtime/vframeArray.hpp"
91 #include "runtime/vframe_hp.hpp"
92 #include "runtime/vmThread.hpp"
93 #include "runtime/vmOperations.hpp"
94 #include "services/threadService.hpp"
95 #include "utilities/copy.hpp"
96 #include "utilities/defaultStream.hpp"
97 #include "utilities/dtrace.hpp"
98 #include "utilities/events.hpp"
99 #include "utilities/macros.hpp"
100 #include "utilities/preserveException.hpp"
101 #include "utilities/spinYield.hpp"
102 #include "utilities/vmError.hpp"
103 #if INCLUDE_JVMCI
104 #include "jvmci/jvmci.hpp"
105 #include "jvmci/jvmciEnv.hpp"
106 #endif
107 #if INCLUDE_JFR
108 #include "jfr/jfr.hpp"
109 #endif
110
111 // Set by os layer.
112 size_t JavaThread::_stack_size_at_create = 0;
113
114 #ifdef DTRACE_ENABLED
115
116 // Only bother with this argument setup if dtrace is available
117
118 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
119 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
120
121 #define DTRACE_THREAD_PROBE(probe, javathread) \
122 { \
123 ResourceMark rm(this); \
124 int len = 0; \
125 const char* name = (javathread)->name(); \
126 len = strlen(name); \
127 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
128 (char *) name, len, \
129 java_lang_Thread::thread_id((javathread)->threadObj()), \
130 (uintptr_t) (javathread)->osthread()->thread_id(), \
131 java_lang_Thread::is_daemon((javathread)->threadObj())); \
132 }
133
134 #else // ndef DTRACE_ENABLED
135
136 #define DTRACE_THREAD_PROBE(probe, javathread)
137
138 #endif // ndef DTRACE_ENABLED
139
140 void JavaThread::smr_delete() {
141 if (_on_thread_list) {
142 ThreadsSMRSupport::smr_delete(this);
143 } else {
144 delete this;
145 }
146 }
147
148 // Initialized by VMThread at vm_global_init
149 OopStorage* JavaThread::_thread_oop_storage = nullptr;
150
151 OopStorage* JavaThread::thread_oop_storage() {
152 assert(_thread_oop_storage != nullptr, "not yet initialized");
153 return _thread_oop_storage;
154 }
155
156 void JavaThread::set_threadOopHandles(oop p) {
157 assert(_thread_oop_storage != nullptr, "not yet initialized");
158 _threadObj = OopHandle(_thread_oop_storage, p);
159 _vthread = OopHandle(_thread_oop_storage, p);
160 _jvmti_vthread = OopHandle(_thread_oop_storage, p->is_a(vmClasses::BoundVirtualThread_klass()) ? p : nullptr);
161 _scopedValueCache = OopHandle(_thread_oop_storage, nullptr);
162 }
163
164 oop JavaThread::threadObj() const {
165 // Ideally we would verify the current thread is oop_safe when this is called, but as we can
166 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That
167 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS.
168 // Instead callers must verify oop safe access.
169 return _threadObj.resolve();
170 }
171
172 oop JavaThread::vthread() const {
173 return _vthread.resolve();
174 }
175
176 void JavaThread::set_vthread(oop p) {
177 assert(_thread_oop_storage != nullptr, "not yet initialized");
178 _vthread.replace(p);
179 }
180
181 oop JavaThread::jvmti_vthread() const {
182 return _jvmti_vthread.resolve();
183 }
184
185 void JavaThread::set_jvmti_vthread(oop p) {
186 assert(_thread_oop_storage != nullptr, "not yet initialized");
187 _jvmti_vthread.replace(p);
188 }
189
190 oop JavaThread::scopedValueCache() const {
191 return _scopedValueCache.resolve();
192 }
193
194 void JavaThread::set_scopedValueCache(oop p) {
195 if (_scopedValueCache.ptr_raw() != nullptr) { // i.e. if the OopHandle has been allocated
196 _scopedValueCache.replace(p);
197 } else {
198 assert(p == nullptr, "not yet initialized");
199 }
200 }
201
202 void JavaThread::clear_scopedValueBindings() {
203 set_scopedValueCache(nullptr);
204 oop vthread_oop = vthread();
205 // vthread may be null here if we get a VM error during startup,
206 // before the java.lang.Thread instance has been created.
207 if (vthread_oop != nullptr) {
208 java_lang_Thread::clear_scopedValueBindings(vthread_oop);
209 }
210 }
211
212 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
213 bool daemon, TRAPS) {
214 assert(thread_group.not_null(), "thread group should be specified");
215 assert(threadObj() == nullptr, "should only create Java thread object once");
216
217 InstanceKlass* ik = vmClasses::Thread_klass();
218 assert(ik->is_initialized(), "must be");
219 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
220
221 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
222 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
223 // constructor calls Thread.current(), which must be set here.
224 java_lang_Thread::set_thread(thread_oop(), this);
225 set_threadOopHandles(thread_oop());
226
227 JavaValue result(T_VOID);
228 if (thread_name != nullptr) {
229 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
230 // Thread gets assigned specified name and null target
231 JavaCalls::call_special(&result,
232 thread_oop,
233 ik,
234 vmSymbols::object_initializer_name(),
235 vmSymbols::threadgroup_string_void_signature(),
236 thread_group,
237 name,
238 THREAD);
239 } else {
240 // Thread gets assigned name "Thread-nnn" and null target
241 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
242 JavaCalls::call_special(&result,
243 thread_oop,
244 ik,
245 vmSymbols::object_initializer_name(),
246 vmSymbols::threadgroup_runnable_void_signature(),
247 thread_group,
248 Handle(),
249 THREAD);
250 }
251 os::set_priority(this, NormPriority);
252
253 if (daemon) {
254 java_lang_Thread::set_daemon(thread_oop());
255 }
256 }
257
258 // ======= JavaThread ========
259
260 #if INCLUDE_JVMCI
261
262 jlong* JavaThread::_jvmci_old_thread_counters;
263
264 bool jvmci_counters_include(JavaThread* thread) {
265 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
266 }
267
268 void JavaThread::collect_counters(jlong* array, int length) {
269 assert(length == JVMCICounterSize, "wrong value");
270 for (int i = 0; i < length; i++) {
271 array[i] = _jvmci_old_thread_counters[i];
272 }
273 for (JavaThread* tp : ThreadsListHandle()) {
274 if (jvmci_counters_include(tp)) {
275 for (int i = 0; i < length; i++) {
276 array[i] += tp->_jvmci_counters[i];
277 }
278 }
279 }
280 }
281
282 // Attempt to enlarge the array for per thread counters.
283 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
284 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
285 if (new_counters == nullptr) {
286 return nullptr;
287 }
288 if (old_counters == nullptr) {
289 old_counters = new_counters;
290 memset(old_counters, 0, sizeof(jlong) * new_size);
291 } else {
292 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
293 new_counters[i] = old_counters[i];
294 }
295 if (new_size > current_size) {
296 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
297 }
298 FREE_C_HEAP_ARRAY(jlong, old_counters);
299 }
300 return new_counters;
301 }
302
303 // Attempt to enlarge the array for per thread counters.
304 bool JavaThread::resize_counters(int current_size, int new_size) {
305 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
306 if (new_counters == nullptr) {
307 return false;
308 } else {
309 _jvmci_counters = new_counters;
310 return true;
311 }
312 }
313
314 class VM_JVMCIResizeCounters : public VM_Operation {
315 private:
316 int _new_size;
317 bool _failed;
318
319 public:
320 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
321 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
322 bool allow_nested_vm_operations() const { return true; }
323 void doit() {
324 // Resize the old thread counters array
325 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
326 if (new_counters == nullptr) {
327 _failed = true;
328 return;
329 } else {
330 JavaThread::_jvmci_old_thread_counters = new_counters;
331 }
332
333 // Now resize each threads array
334 for (JavaThread* tp : ThreadsListHandle()) {
335 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
336 _failed = true;
337 break;
338 }
339 }
340 if (!_failed) {
341 JVMCICounterSize = _new_size;
342 }
343 }
344
345 bool failed() { return _failed; }
346 };
347
348 bool JavaThread::resize_all_jvmci_counters(int new_size) {
349 VM_JVMCIResizeCounters op(new_size);
350 VMThread::execute(&op);
351 return !op.failed();
352 }
353
354 #endif // INCLUDE_JVMCI
355
356 #ifdef ASSERT
357 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
358 void JavaThread::check_possible_safepoint() {
359 if (_no_safepoint_count > 0) {
360 print_owned_locks();
361 assert(false, "Possible safepoint reached by thread that does not allow it");
362 }
363 #ifdef CHECK_UNHANDLED_OOPS
364 // Clear unhandled oops in JavaThreads so we get a crash right away.
365 clear_unhandled_oops();
366 #endif // CHECK_UNHANDLED_OOPS
367
368 // Macos/aarch64 should be in the right state for safepoint (e.g.
369 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely
370 // happens in practice, making such issues hard to find and reproduce.
371 #if defined(__APPLE__) && defined(AARCH64)
372 if (AssertWXAtThreadSync) {
373 assert_wx_state(WXWrite);
374 }
375 #endif
376 }
377
378 void JavaThread::check_for_valid_safepoint_state() {
379 // Check NoSafepointVerifier, which is implied by locks taken that can be
380 // shared with the VM thread. This makes sure that no locks with allow_vm_block
381 // are held.
382 check_possible_safepoint();
383
384 if (thread_state() != _thread_in_vm) {
385 fatal("LEAF method calling lock?");
386 }
387
388 if (GCALotAtAllSafepoints) {
389 // We could enter a safepoint here and thus have a gc
390 InterfaceSupport::check_gc_alot();
391 }
392 }
393 #endif // ASSERT
394
395 // A JavaThread is a normal Java thread
396
397 JavaThread::JavaThread() :
398 // Initialize fields
399
400 _on_thread_list(false),
401 DEBUG_ONLY(_java_call_counter(0) COMMA)
402 _entry_point(nullptr),
403 _deopt_mark(nullptr),
404 _deopt_nmethod(nullptr),
405 _vframe_array_head(nullptr),
406 _vframe_array_last(nullptr),
407 _jvmti_deferred_updates(nullptr),
408 _callee_target(nullptr),
409 _vm_result(nullptr),
410 _vm_result_2(nullptr),
411
412 _current_pending_monitor(nullptr),
413 _current_pending_monitor_is_from_java(true),
414 _current_waiting_monitor(nullptr),
415 _active_handles(nullptr),
416 _free_handle_block(nullptr),
417 _Stalled(0),
418
419 _monitor_chunks(nullptr),
420
421 _suspend_flags(0),
422
423 _thread_state(_thread_new),
424 _saved_exception_pc(nullptr),
425 #ifdef ASSERT
426 _no_safepoint_count(0),
427 _visited_for_critical_count(false),
428 #endif
429
430 _terminated(_not_terminated),
431 _in_deopt_handler(0),
432 _doing_unsafe_access(false),
433 _do_not_unlock_if_synchronized(false),
434 #if INCLUDE_JVMTI
435 _carrier_thread_suspended(false),
436 _is_in_VTMS_transition(false),
437 _is_in_tmp_VTMS_transition(false),
438 #ifdef ASSERT
439 _is_VTMS_transition_disabler(false),
440 #endif
441 #endif
442 _jni_attach_state(_not_attaching_via_jni),
443 #if INCLUDE_JVMCI
444 _pending_deoptimization(-1),
445 _pending_monitorenter(false),
446 _pending_transfer_to_interpreter(false),
447 _in_retryable_allocation(false),
448 _pending_failed_speculation(0),
449 _jvmci{nullptr},
450 _libjvmci_runtime(nullptr),
451 _jvmci_counters(nullptr),
452 _jvmci_reserved0(0),
453 _jvmci_reserved1(0),
454 _jvmci_reserved_oop0(nullptr),
455 #endif // INCLUDE_JVMCI
456
457 _exception_oop(oop()),
458 _exception_pc(0),
459 _exception_handler_pc(0),
460 _is_method_handle_return(0),
461
462 _jni_active_critical(0),
463 _pending_jni_exception_check_fn(nullptr),
464 _depth_first_number(0),
465
466 // JVMTI PopFrame support
467 _popframe_condition(popframe_inactive),
468 _frames_to_pop_failed_realloc(0),
469
470 _cont_entry(nullptr),
471 _cont_fastpath(0),
472 _cont_fastpath_thread_state(1),
473 _held_monitor_count(0),
474 _jni_monitor_count(0),
475
476 _handshake(this),
477
478 _popframe_preserved_args(nullptr),
479 _popframe_preserved_args_size(0),
480
481 _jvmti_thread_state(nullptr),
482 _interp_only_mode(0),
483 _should_post_on_exceptions_flag(JNI_FALSE),
484 _thread_stat(new ThreadStatistics()),
485
486 _parker(),
487
488 _class_to_be_initialized(nullptr),
489
490 _SleepEvent(ParkEvent::Allocate(this))
491 {
492 set_jni_functions(jni_functions());
493
494 #if INCLUDE_JVMCI
495 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
496 if (JVMCICounterSize > 0) {
497 resize_counters(0, (int) JVMCICounterSize);
498 }
499 #endif // INCLUDE_JVMCI
500
501 // Setup safepoint state info for this thread
502 ThreadSafepointState::create(this);
503
504 SafepointMechanism::initialize_header(this);
505
506 set_requires_cross_modify_fence(false);
507
508 pd_initialize();
509 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
510 }
511
512 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
513 if (is_attaching_via_jni) {
514 _jni_attach_state = _attaching_via_jni;
515 }
516 }
517
518
519 // interrupt support
520
521 void JavaThread::interrupt() {
522 // All callers should have 'this' thread protected by a
523 // ThreadsListHandle so that it cannot terminate and deallocate
524 // itself.
525 debug_only(check_for_dangling_thread_pointer(this);)
526
527 // For Windows _interrupt_event
528 WINDOWS_ONLY(osthread()->set_interrupted(true);)
529
530 // For Thread.sleep
531 _SleepEvent->unpark();
532
533 // For JSR166 LockSupport.park
534 parker()->unpark();
535
536 // For ObjectMonitor and JvmtiRawMonitor
537 _ParkEvent->unpark();
538 }
539
540
541 bool JavaThread::is_interrupted(bool clear_interrupted) {
542 debug_only(check_for_dangling_thread_pointer(this);)
543
544 if (_threadObj.peek() == nullptr) {
545 // If there is no j.l.Thread then it is impossible to have
546 // been interrupted. We can find null during VM initialization
547 // or when a JNI thread is still in the process of attaching.
548 // In such cases this must be the current thread.
549 assert(this == Thread::current(), "invariant");
550 return false;
551 }
552
553 bool interrupted = java_lang_Thread::interrupted(threadObj());
554
555 // NOTE that since there is no "lock" around the interrupt and
556 // is_interrupted operations, there is the possibility that the
557 // interrupted flag will be "false" but that the
558 // low-level events will be in the signaled state. This is
559 // intentional. The effect of this is that Object.wait() and
560 // LockSupport.park() will appear to have a spurious wakeup, which
561 // is allowed and not harmful, and the possibility is so rare that
562 // it is not worth the added complexity to add yet another lock.
563 // For the sleep event an explicit reset is performed on entry
564 // to JavaThread::sleep, so there is no early return. It has also been
565 // recommended not to put the interrupted flag into the "event"
566 // structure because it hides the issue.
567 // Also, because there is no lock, we must only clear the interrupt
568 // state if we are going to report that we were interrupted; otherwise
569 // an interrupt that happens just after we read the field would be lost.
570 if (interrupted && clear_interrupted) {
571 assert(this == Thread::current(), "only the current thread can clear");
572 java_lang_Thread::set_interrupted(threadObj(), false);
573 WINDOWS_ONLY(osthread()->set_interrupted(false);)
574 }
575
576 return interrupted;
577 }
578
579 void JavaThread::block_if_vm_exited() {
580 if (_terminated == _vm_exited) {
581 // _vm_exited is set at safepoint, and Threads_lock is never released
582 // so we will block here forever.
583 // Here we can be doing a jump from a safe state to an unsafe state without
584 // proper transition, but it happens after the final safepoint has begun so
585 // this jump won't cause any safepoint problems.
586 set_thread_state(_thread_in_vm);
587 Threads_lock->lock();
588 ShouldNotReachHere();
589 }
590 }
591
592 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
593 _jni_attach_state = _not_attaching_via_jni;
594 set_entry_point(entry_point);
595 // Create the native thread itself.
596 // %note runtime_23
597 os::ThreadType thr_type = os::java_thread;
598 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
599 os::java_thread;
600 os::create_thread(this, thr_type, stack_sz);
601 // The _osthread may be null here because we ran out of memory (too many threads active).
602 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
603 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
604 // the exception consists of creating the exception object & initializing it, initialization
605 // will leave the VM via a JavaCall and then all locks must be unlocked).
606 //
607 // The thread is still suspended when we reach here. Thread must be explicit started
608 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
609 // by calling Threads:add. The reason why this is not done here, is because the thread
610 // object must be fully initialized (take a look at JVM_Start)
611 }
612
613 JavaThread::~JavaThread() {
614
615 // Enqueue OopHandles for release by the service thread.
616 add_oop_handles_for_release();
617
618 // Return the sleep event to the free list
619 ParkEvent::Release(_SleepEvent);
620 _SleepEvent = nullptr;
621
622 // Free any remaining previous UnrollBlock
623 vframeArray* old_array = vframe_array_last();
624
625 if (old_array != nullptr) {
626 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
627 old_array->set_unroll_block(nullptr);
628 delete old_info;
629 delete old_array;
630 }
631
632 JvmtiDeferredUpdates* updates = deferred_updates();
633 if (updates != nullptr) {
634 // This can only happen if thread is destroyed before deoptimization occurs.
635 assert(updates->count() > 0, "Updates holder not deleted");
636 // free deferred updates.
637 delete updates;
638 set_deferred_updates(nullptr);
639 }
640
641 // All Java related clean up happens in exit
642 ThreadSafepointState::destroy(this);
643 if (_thread_stat != nullptr) delete _thread_stat;
644
645 #if INCLUDE_JVMCI
646 if (JVMCICounterSize > 0) {
647 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
648 }
649 #endif // INCLUDE_JVMCI
650 }
651
652
653 // First JavaThread specific code executed by a new Java thread.
654 void JavaThread::pre_run() {
655 // empty - see comments in run()
656 }
657
658 // The main routine called by a new Java thread. This isn't overridden
659 // by subclasses, instead different subclasses define a different "entry_point"
660 // which defines the actual logic for that kind of thread.
661 void JavaThread::run() {
662 // initialize thread-local alloc buffer related fields
663 initialize_tlab();
664
665 _stack_overflow_state.create_stack_guard_pages();
666
667 cache_global_variables();
668
669 // Thread is now sufficiently initialized to be handled by the safepoint code as being
670 // in the VM. Change thread state from _thread_new to _thread_in_vm
671 assert(this->thread_state() == _thread_new, "wrong thread state");
672 set_thread_state(_thread_in_vm);
673
674 // Before a thread is on the threads list it is always safe, so after leaving the
675 // _thread_new we should emit a instruction barrier. The distance to modified code
676 // from here is probably far enough, but this is consistent and safe.
677 OrderAccess::cross_modify_fence();
678
679 assert(JavaThread::current() == this, "sanity check");
680 assert(!Thread::current()->owns_locks(), "sanity check");
681
682 DTRACE_THREAD_PROBE(start, this);
683
684 // This operation might block. We call that after all safepoint checks for a new thread has
685 // been completed.
686 set_active_handles(JNIHandleBlock::allocate_block());
687
688 if (JvmtiExport::should_post_thread_life()) {
689 JvmtiExport::post_thread_start(this);
690
691 }
692
693 // We call another function to do the rest so we are sure that the stack addresses used
694 // from there will be lower than the stack base just computed.
695 thread_main_inner();
696 }
697
698 void JavaThread::thread_main_inner() {
699 assert(JavaThread::current() == this, "sanity check");
700 assert(_threadObj.peek() != nullptr, "just checking");
701
702 // Execute thread entry point unless this thread has a pending exception.
703 // Note: Due to JVMTI StopThread we can have pending exceptions already!
704 if (!this->has_pending_exception()) {
705 {
706 ResourceMark rm(this);
707 this->set_native_thread_name(this->name());
708 }
709 HandleMark hm(this);
710 this->entry_point()(this, this);
711 }
712
713 DTRACE_THREAD_PROBE(stop, this);
714
715 // Cleanup is handled in post_run()
716 }
717
718 // Shared teardown for all JavaThreads
719 void JavaThread::post_run() {
720 this->exit(false);
721 this->unregister_thread_stack_with_NMT();
722 // Defer deletion to here to ensure 'this' is still referenceable in call_run
723 // for any shared tear-down.
724 this->smr_delete();
725 }
726
727 static void ensure_join(JavaThread* thread) {
728 // We do not need to grab the Threads_lock, since we are operating on ourself.
729 Handle threadObj(thread, thread->threadObj());
730 assert(threadObj.not_null(), "java thread object must exist");
731 ObjectLocker lock(threadObj, thread);
732 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
733 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
734 // Clear the native thread instance - this makes isAlive return false and allows the join()
735 // to complete once we've done the notify_all below
736 java_lang_Thread::set_thread(threadObj(), nullptr);
737 lock.notify_all(thread);
738 // Ignore pending exception, since we are exiting anyway
739 thread->clear_pending_exception();
740 }
741
742 static bool is_daemon(oop threadObj) {
743 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj));
744 }
745
746 // For any new cleanup additions, please check to see if they need to be applied to
747 // cleanup_failed_attach_current_thread as well.
748 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
749 assert(this == JavaThread::current(), "thread consistency check");
750 assert(!is_exiting(), "should not be exiting or terminated already");
751
752 elapsedTimer _timer_exit_phase1;
753 elapsedTimer _timer_exit_phase2;
754 elapsedTimer _timer_exit_phase3;
755 elapsedTimer _timer_exit_phase4;
756
757 if (log_is_enabled(Debug, os, thread, timer)) {
758 _timer_exit_phase1.start();
759 }
760
761 HandleMark hm(this);
762 Handle uncaught_exception(this, this->pending_exception());
763 this->clear_pending_exception();
764 Handle threadObj(this, this->threadObj());
765 assert(threadObj.not_null(), "Java thread object should be created");
766
767 if (!destroy_vm) {
768 if (uncaught_exception.not_null()) {
769 EXCEPTION_MARK;
770 // Call method Thread.dispatchUncaughtException().
771 Klass* thread_klass = vmClasses::Thread_klass();
772 JavaValue result(T_VOID);
773 JavaCalls::call_virtual(&result,
774 threadObj, thread_klass,
775 vmSymbols::dispatchUncaughtException_name(),
776 vmSymbols::throwable_void_signature(),
777 uncaught_exception,
778 THREAD);
779 if (HAS_PENDING_EXCEPTION) {
780 ResourceMark rm(this);
781 jio_fprintf(defaultStream::error_stream(),
782 "\nException: %s thrown from the UncaughtExceptionHandler"
783 " in thread \"%s\"\n",
784 pending_exception()->klass()->external_name(),
785 name());
786 CLEAR_PENDING_EXCEPTION;
787 }
788 }
789
790 if (!is_Compiler_thread()) {
791 // We have finished executing user-defined Java code and now have to do the
792 // implementation specific clean-up by calling Thread.exit(). We prevent any
793 // asynchronous exceptions from being delivered while in Thread.exit()
794 // to ensure the clean-up is not corrupted.
795 NoAsyncExceptionDeliveryMark _no_async(this);
796
797 EXCEPTION_MARK;
798 JavaValue result(T_VOID);
799 Klass* thread_klass = vmClasses::Thread_klass();
800 JavaCalls::call_virtual(&result,
801 threadObj, thread_klass,
802 vmSymbols::exit_method_name(),
803 vmSymbols::void_method_signature(),
804 THREAD);
805 CLEAR_PENDING_EXCEPTION;
806 }
807
808 // notify JVMTI
809 if (JvmtiExport::should_post_thread_life()) {
810 JvmtiExport::post_thread_end(this);
811 }
812 } else {
813 // before_exit() has already posted JVMTI THREAD_END events
814 }
815
816 // Cleanup any pending async exception now since we cannot access oops after
817 // BarrierSet::barrier_set()->on_thread_detach() has been executed.
818 if (has_async_exception_condition()) {
819 handshake_state()->clean_async_exception_operation();
820 }
821
822 // The careful dance between thread suspension and exit is handled here.
823 // Since we are in thread_in_vm state and suspension is done with handshakes,
824 // we can just put in the exiting state and it will be correctly handled.
825 // Also, no more async exceptions will be added to the queue after this point.
826 set_terminated(_thread_exiting);
827 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
828
829 if (log_is_enabled(Debug, os, thread, timer)) {
830 _timer_exit_phase1.stop();
831 _timer_exit_phase2.start();
832 }
833
834 // Capture daemon status before the thread is marked as terminated.
835 bool daemon = is_daemon(threadObj());
836
837 // Notify waiters on thread object. This has to be done after exit() is called
838 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
839 // group should have the destroyed bit set before waiters are notified).
840 ensure_join(this);
841 assert(!this->has_pending_exception(), "ensure_join should have cleared");
842
843 if (log_is_enabled(Debug, os, thread, timer)) {
844 _timer_exit_phase2.stop();
845 _timer_exit_phase3.start();
846 }
847 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
848 // held by this thread must be released. The spec does not distinguish
849 // between JNI-acquired and regular Java monitors. We can only see
850 // regular Java monitors here if monitor enter-exit matching is broken.
851 //
852 // ensure_join() ignores IllegalThreadStateExceptions, and so does
853 // ObjectSynchronizer::release_monitors_owned_by_thread().
854 if (exit_type == jni_detach) {
855 // Sanity check even though JNI DetachCurrentThread() would have
856 // returned JNI_ERR if there was a Java frame. JavaThread exit
857 // should be done executing Java code by the time we get here.
858 assert(!this->has_last_Java_frame(),
859 "should not have a Java frame when detaching or exiting");
860 ObjectSynchronizer::release_monitors_owned_by_thread(this);
861 assert(!this->has_pending_exception(), "release_monitors should have cleared");
862 }
863
864 // Since above code may not release JNI monitors and if someone forgot to do an
865 // JNI monitorexit, held count should be equal jni count.
866 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach).
867 assert(this->held_monitor_count() == this->jni_monitor_count(),
868 "held monitor count should be equal to jni: " INT64_FORMAT " != " INT64_FORMAT,
869 (int64_t)this->held_monitor_count(), (int64_t)this->jni_monitor_count());
870 if (CheckJNICalls && this->jni_monitor_count() > 0) {
871 // We would like a fatal here, but due to we never checked this before there
872 // is a lot of tests which breaks, even with an error log.
873 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.",
874 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id());
875 }
876
877 // These things needs to be done while we are still a Java Thread. Make sure that thread
878 // is in a consistent state, in case GC happens
879 JFR_ONLY(Jfr::on_thread_exit(this);)
880
881 if (active_handles() != nullptr) {
882 JNIHandleBlock* block = active_handles();
883 set_active_handles(nullptr);
884 JNIHandleBlock::release_block(block);
885 }
886
887 if (free_handle_block() != nullptr) {
888 JNIHandleBlock* block = free_handle_block();
889 set_free_handle_block(nullptr);
890 JNIHandleBlock::release_block(block);
891 }
892
893 // These have to be removed while this is still a valid thread.
894 _stack_overflow_state.remove_stack_guard_pages();
895
896 if (UseTLAB) {
897 tlab().retire();
898 }
899
900 if (JvmtiEnv::environments_might_exist()) {
901 JvmtiExport::cleanup_thread(this);
902 }
903
904 // We need to cache the thread name for logging purposes below as once
905 // we have called on_thread_detach this thread must not access any oops.
906 char* thread_name = nullptr;
907 if (log_is_enabled(Debug, os, thread, timer)) {
908 ResourceMark rm(this);
909 thread_name = os::strdup(name());
910 }
911
912 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
913 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
914 os::current_thread_id());
915
916 if (log_is_enabled(Debug, os, thread, timer)) {
917 _timer_exit_phase3.stop();
918 _timer_exit_phase4.start();
919 }
920
921 #if INCLUDE_JVMCI
922 if (JVMCICounterSize > 0) {
923 if (jvmci_counters_include(this)) {
924 for (int i = 0; i < JVMCICounterSize; i++) {
925 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
926 }
927 }
928 }
929 #endif // INCLUDE_JVMCI
930
931 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
932 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
933 Threads::remove(this, daemon);
934
935 if (log_is_enabled(Debug, os, thread, timer)) {
936 _timer_exit_phase4.stop();
937 log_debug(os, thread, timer)("name='%s'"
938 ", exit-phase1=" JLONG_FORMAT
939 ", exit-phase2=" JLONG_FORMAT
940 ", exit-phase3=" JLONG_FORMAT
941 ", exit-phase4=" JLONG_FORMAT,
942 thread_name,
943 _timer_exit_phase1.milliseconds(),
944 _timer_exit_phase2.milliseconds(),
945 _timer_exit_phase3.milliseconds(),
946 _timer_exit_phase4.milliseconds());
947 os::free(thread_name);
948 }
949 }
950
951 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
952 if (active_handles() != nullptr) {
953 JNIHandleBlock* block = active_handles();
954 set_active_handles(nullptr);
955 JNIHandleBlock::release_block(block);
956 }
957
958 if (free_handle_block() != nullptr) {
959 JNIHandleBlock* block = free_handle_block();
960 set_free_handle_block(nullptr);
961 JNIHandleBlock::release_block(block);
962 }
963
964 // These have to be removed while this is still a valid thread.
965 _stack_overflow_state.remove_stack_guard_pages();
966
967 if (UseTLAB) {
968 tlab().retire();
969 }
970
971 Threads::remove(this, is_daemon);
972 this->smr_delete();
973 }
974
975 JavaThread* JavaThread::active() {
976 Thread* thread = Thread::current();
977 if (thread->is_Java_thread()) {
978 return JavaThread::cast(thread);
979 } else {
980 assert(thread->is_VM_thread(), "this must be a vm thread");
981 VM_Operation* op = ((VMThread*) thread)->vm_operation();
982 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread());
983 return ret;
984 }
985 }
986
987 bool JavaThread::is_lock_owned(address adr) const {
988 if (Thread::is_lock_owned(adr)) return true;
989
990 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
991 if (chunk->contains(adr)) return true;
992 }
993
994 return false;
995 }
996
997 oop JavaThread::exception_oop() const {
998 return Atomic::load(&_exception_oop);
999 }
1000
1001 void JavaThread::set_exception_oop(oop o) {
1002 Atomic::store(&_exception_oop, o);
1003 }
1004
1005 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1006 chunk->set_next(monitor_chunks());
1007 set_monitor_chunks(chunk);
1008 }
1009
1010 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1011 guarantee(monitor_chunks() != nullptr, "must be non empty");
1012 if (monitor_chunks() == chunk) {
1013 set_monitor_chunks(chunk->next());
1014 } else {
1015 MonitorChunk* prev = monitor_chunks();
1016 while (prev->next() != chunk) prev = prev->next();
1017 prev->set_next(chunk->next());
1018 }
1019 }
1020
1021 void JavaThread::handle_special_runtime_exit_condition() {
1022 if (is_obj_deopt_suspend()) {
1023 frame_anchor()->make_walkable();
1024 wait_for_object_deoptimization();
1025 }
1026 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1027 }
1028
1029
1030 // Asynchronous exceptions support
1031 //
1032 void JavaThread::handle_async_exception(oop java_throwable) {
1033 assert(java_throwable != nullptr, "should have an _async_exception to throw");
1034 assert(!is_at_poll_safepoint(), "should have never called this method");
1035
1036 if (has_last_Java_frame()) {
1037 frame f = last_frame();
1038 if (f.is_runtime_frame()) {
1039 // If the topmost frame is a runtime stub, then we are calling into
1040 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1041 // must deoptimize the caller before continuing, as the compiled exception
1042 // handler table may not be valid.
1043 RegisterMap reg_map(this,
1044 RegisterMap::UpdateMap::skip,
1045 RegisterMap::ProcessFrames::include,
1046 RegisterMap::WalkContinuation::skip);
1047 frame compiled_frame = f.sender(®_map);
1048 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1049 Deoptimization::deoptimize(this, compiled_frame);
1050 }
1051 }
1052 }
1053
1054 // We cannot call Exceptions::_throw(...) here because we cannot block
1055 set_pending_exception(java_throwable, __FILE__, __LINE__);
1056
1057 clear_scopedValueBindings();
1058
1059 LogTarget(Info, exceptions) lt;
1060 if (lt.is_enabled()) {
1061 ResourceMark rm;
1062 LogStream ls(lt);
1063 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1064 if (has_last_Java_frame()) {
1065 frame f = last_frame();
1066 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1067 }
1068 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1069 }
1070 }
1071
1072 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1073 // Do not throw asynchronous exceptions against the compiler thread
1074 // or if the thread is already exiting.
1075 if (!can_call_java() || is_exiting()) {
1076 delete aeh;
1077 return;
1078 }
1079
1080 oop exception = aeh->exception();
1081 Handshake::execute(aeh, this); // Install asynchronous handshake
1082
1083 ResourceMark rm;
1084 if (log_is_enabled(Info, exceptions)) {
1085 log_info(exceptions)("Pending Async. exception installed of type: %s",
1086 InstanceKlass::cast(exception->klass())->external_name());
1087 }
1088 // for AbortVMOnException flag
1089 Exceptions::debug_check_abort(exception->klass()->external_name());
1090
1091 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1092 java_lang_Thread::set_interrupted(threadObj(), true);
1093 this->interrupt();
1094 }
1095
1096 class InstallAsyncExceptionHandshake : public HandshakeClosure {
1097 AsyncExceptionHandshake* _aeh;
1098 public:
1099 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1100 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1101 ~InstallAsyncExceptionHandshake() {
1102 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh.
1103 delete _aeh;
1104 }
1105 void do_thread(Thread* thr) {
1106 JavaThread* target = JavaThread::cast(thr);
1107 target->install_async_exception(_aeh);
1108 _aeh = nullptr;
1109 }
1110 };
1111
1112 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1113 OopHandle e(Universe::vm_global(), java_throwable);
1114 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1115 Handshake::execute(&iaeh, target);
1116 }
1117
1118 #if INCLUDE_JVMTI
1119 void JavaThread::set_is_in_VTMS_transition(bool val) {
1120 _is_in_VTMS_transition = val;
1121 }
1122
1123 #ifdef ASSERT
1124 void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1125 _is_VTMS_transition_disabler = val;
1126 }
1127 #endif
1128 #endif
1129
1130 // External suspension mechanism.
1131 //
1132 // Guarantees on return (for a valid target thread):
1133 // - Target thread will not execute any new bytecode.
1134 // - Target thread will not enter any new monitors.
1135 //
1136 bool JavaThread::java_suspend() {
1137 #if INCLUDE_JVMTI
1138 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1139 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1140 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1141 #endif
1142
1143 guarantee(Thread::is_JavaThread_protected(/* target */ this),
1144 "target JavaThread is not protected in calling context.");
1145 return this->handshake_state()->suspend();
1146 }
1147
1148 bool JavaThread::java_resume() {
1149 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1150 "missing ThreadsListHandle in calling context.");
1151 return this->handshake_state()->resume();
1152 }
1153
1154 // Wait for another thread to perform object reallocation and relocking on behalf of
1155 // this thread. The current thread is required to change to _thread_blocked in order
1156 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1157 // handshake safe, the other thread can complete the handshake used to synchronize
1158 // with this thread and then perform the reallocation and relocking.
1159 // See EscapeBarrier::sync_and_suspend_*()
1160
1161 void JavaThread::wait_for_object_deoptimization() {
1162 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1163 assert(this == Thread::current(), "invariant");
1164
1165 bool spin_wait = os::is_MP();
1166 do {
1167 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1168 // Wait for object deoptimization if requested.
1169 if (spin_wait) {
1170 // A single deoptimization is typically very short. Microbenchmarks
1171 // showed 5% better performance when spinning.
1172 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1173 SpinYield spin(spin_limit);
1174 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1175 spin.wait();
1176 }
1177 // Spin just once
1178 spin_wait = false;
1179 } else {
1180 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1181 if (is_obj_deopt_suspend()) {
1182 ml.wait();
1183 }
1184 }
1185 // A handshake for obj. deoptimization suspend could have been processed so
1186 // we must check after processing.
1187 } while (is_obj_deopt_suspend());
1188 }
1189
1190 #ifdef ASSERT
1191 // Verify the JavaThread has not yet been published in the Threads::list, and
1192 // hence doesn't need protection from concurrent access at this stage.
1193 void JavaThread::verify_not_published() {
1194 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1195 // since an unpublished JavaThread doesn't participate in the
1196 // Thread-SMR protocol for keeping a ThreadsList alive.
1197 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1198 }
1199 #endif
1200
1201 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1202 // pending, when _suspend_flags is non-zero or when we need to process a stack
1203 // watermark. Also check for pending async exceptions (except unsafe access error).
1204 // Note only the native==>Java barriers can call this function when thread state
1205 // is _thread_in_native_trans.
1206 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1207 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1208 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1209
1210 thread->set_thread_state(_thread_in_vm);
1211
1212 // Enable WXWrite: called directly from interpreter native wrapper.
1213 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1214
1215 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1216
1217 // After returning from native, it could be that the stack frames are not
1218 // yet safe to use. We catch such situations in the subsequent stack watermark
1219 // barrier, which will trap unsafe stack frames.
1220 StackWatermarkSet::before_unwind(thread);
1221 }
1222
1223 #ifndef PRODUCT
1224 // Deoptimization
1225 // Function for testing deoptimization
1226 void JavaThread::deoptimize() {
1227 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1228 bool deopt = false; // Dump stack only if a deopt actually happens.
1229 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1230 // Iterate over all frames in the thread and deoptimize
1231 for (; !fst.is_done(); fst.next()) {
1232 if (fst.current()->can_be_deoptimized()) {
1233
1234 if (only_at) {
1235 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1236 // consists of comma or carriage return separated numbers so
1237 // search for the current bci in that string.
1238 address pc = fst.current()->pc();
1239 nmethod* nm = (nmethod*) fst.current()->cb();
1240 ScopeDesc* sd = nm->scope_desc_at(pc);
1241 char buffer[8];
1242 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1243 size_t len = strlen(buffer);
1244 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1245 while (found != nullptr) {
1246 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1247 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1248 // Check that the bci found is bracketed by terminators.
1249 break;
1250 }
1251 found = strstr(found + 1, buffer);
1252 }
1253 if (!found) {
1254 continue;
1255 }
1256 }
1257
1258 if (DebugDeoptimization && !deopt) {
1259 deopt = true; // One-time only print before deopt
1260 tty->print_cr("[BEFORE Deoptimization]");
1261 trace_frames();
1262 trace_stack();
1263 }
1264 Deoptimization::deoptimize(this, *fst.current());
1265 }
1266 }
1267
1268 if (DebugDeoptimization && deopt) {
1269 tty->print_cr("[AFTER Deoptimization]");
1270 trace_frames();
1271 }
1272 }
1273
1274
1275 // Make zombies
1276 void JavaThread::make_zombies() {
1277 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1278 if (fst.current()->can_be_deoptimized()) {
1279 // it is a Java nmethod
1280 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1281 nm->make_not_entrant();
1282 }
1283 }
1284 }
1285 #endif // PRODUCT
1286
1287
1288 void JavaThread::deoptimize_marked_methods() {
1289 if (!has_last_Java_frame()) return;
1290 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1291 for (; !fst.is_done(); fst.next()) {
1292 if (fst.current()->should_be_deoptimized()) {
1293 Deoptimization::deoptimize(this, *fst.current());
1294 }
1295 }
1296 }
1297
1298 #ifdef ASSERT
1299 void JavaThread::verify_frame_info() {
1300 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1301 (has_last_Java_frame() && java_call_counter() > 0),
1302 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1303 has_last_Java_frame() ? "true" : "false", java_call_counter());
1304 }
1305 #endif
1306
1307 // Push on a new block of JNI handles.
1308 void JavaThread::push_jni_handle_block() {
1309 // Allocate a new block for JNI handles.
1310 // Inlined code from jni_PushLocalFrame()
1311 JNIHandleBlock* old_handles = active_handles();
1312 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1313 assert(old_handles != nullptr && new_handles != nullptr, "should not be null");
1314 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1315 set_active_handles(new_handles);
1316 }
1317
1318 // Pop off the current block of JNI handles.
1319 void JavaThread::pop_jni_handle_block() {
1320 // Release our JNI handle block
1321 JNIHandleBlock* old_handles = active_handles();
1322 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1323 assert(new_handles != nullptr, "should never set active handles to null");
1324 set_active_handles(new_handles);
1325 old_handles->set_pop_frame_link(nullptr);
1326 JNIHandleBlock::release_block(old_handles, this);
1327 }
1328
1329 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1330 // Verify that the deferred card marks have been flushed.
1331 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1332
1333 // Traverse the GCHandles
1334 Thread::oops_do_no_frames(f, cf);
1335
1336 if (active_handles() != nullptr) {
1337 active_handles()->oops_do(f);
1338 }
1339
1340 DEBUG_ONLY(verify_frame_info();)
1341
1342 if (has_last_Java_frame()) {
1343 // Traverse the monitor chunks
1344 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1345 chunk->oops_do(f);
1346 }
1347 }
1348
1349 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!");
1350 // If we have deferred set_locals there might be oops waiting to be
1351 // written
1352 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1353 if (list != nullptr) {
1354 for (int i = 0; i < list->length(); i++) {
1355 list->at(i)->oops_do(f);
1356 }
1357 }
1358
1359 // Traverse instance variables at the end since the GC may be moving things
1360 // around using this function
1361 f->do_oop((oop*) &_vm_result);
1362 f->do_oop((oop*) &_exception_oop);
1363 #if INCLUDE_JVMCI
1364 f->do_oop((oop*) &_jvmci_reserved_oop0);
1365 #endif
1366
1367 if (jvmti_thread_state() != nullptr) {
1368 jvmti_thread_state()->oops_do(f, cf);
1369 }
1370
1371 // The continuation oops are really on the stack. But there is typically at most
1372 // one of those per thread, so we handle them here in the oops_do_no_frames part
1373 // so that we don't have to sprinkle as many stack watermark checks where these
1374 // oops are used. We just need to make sure the thread has started processing.
1375 ContinuationEntry* entry = _cont_entry;
1376 while (entry != nullptr) {
1377 f->do_oop((oop*)entry->cont_addr());
1378 f->do_oop((oop*)entry->chunk_addr());
1379 entry = entry->parent();
1380 }
1381 }
1382
1383 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
1384 if (!has_last_Java_frame()) {
1385 return;
1386 }
1387 // Finish any pending lazy GC activity for the frames
1388 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc);
1389 // Traverse the execution stack
1390 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1391 fst.current()->oops_do(f, cf, fst.register_map());
1392 }
1393 }
1394
1395 #ifdef ASSERT
1396 void JavaThread::verify_states_for_handshake() {
1397 // This checks that the thread has a correct frame state during a handshake.
1398 verify_frame_info();
1399 }
1400 #endif
1401
1402 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1403 DEBUG_ONLY(verify_frame_info();)
1404 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1405
1406 if (has_last_Java_frame()) {
1407 // Traverse the execution stack
1408 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1409 fst.current()->nmethods_do(cf);
1410 }
1411 }
1412
1413 if (jvmti_thread_state() != nullptr) {
1414 jvmti_thread_state()->nmethods_do(cf);
1415 }
1416 }
1417
1418 void JavaThread::metadata_do(MetadataClosure* f) {
1419 if (has_last_Java_frame()) {
1420 // Traverse the execution stack to call f() on the methods in the stack
1421 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1422 fst.current()->metadata_do(f);
1423 }
1424 } else if (is_Compiler_thread()) {
1425 // need to walk ciMetadata in current compile tasks to keep alive.
1426 CompilerThread* ct = (CompilerThread*)this;
1427 if (ct->env() != nullptr) {
1428 ct->env()->metadata_do(f);
1429 }
1430 CompileTask* task = ct->task();
1431 if (task != nullptr) {
1432 task->metadata_do(f);
1433 }
1434 }
1435 }
1436
1437 // Printing
1438 const char* _get_thread_state_name(JavaThreadState _thread_state) {
1439 switch (_thread_state) {
1440 case _thread_uninitialized: return "_thread_uninitialized";
1441 case _thread_new: return "_thread_new";
1442 case _thread_new_trans: return "_thread_new_trans";
1443 case _thread_in_native: return "_thread_in_native";
1444 case _thread_in_native_trans: return "_thread_in_native_trans";
1445 case _thread_in_vm: return "_thread_in_vm";
1446 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1447 case _thread_in_Java: return "_thread_in_Java";
1448 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1449 case _thread_blocked: return "_thread_blocked";
1450 case _thread_blocked_trans: return "_thread_blocked_trans";
1451 default: return "unknown thread state";
1452 }
1453 }
1454
1455 void JavaThread::print_thread_state_on(outputStream *st) const {
1456 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1457 }
1458
1459 // Called by Threads::print() for VM_PrintThreads operation
1460 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1461 st->print_raw("\"");
1462 st->print_raw(name());
1463 st->print_raw("\" ");
1464 oop thread_oop = threadObj();
1465 if (thread_oop != nullptr) {
1466 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1467 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1468 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1469 }
1470 Thread::print_on(st, print_extended_info);
1471 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1472 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1473 if (thread_oop != nullptr) {
1474 if (is_vthread_mounted()) {
1475 oop vt = vthread();
1476 assert(vt != nullptr, "");
1477 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1478 } else {
1479 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1480 }
1481 }
1482 #ifndef PRODUCT
1483 _safepoint_state->print_on(st);
1484 #endif // PRODUCT
1485 if (is_Compiler_thread()) {
1486 CompileTask *task = ((CompilerThread*)this)->task();
1487 if (task != nullptr) {
1488 st->print(" Compiling: ");
1489 task->print(st, nullptr, true, false);
1490 } else {
1491 st->print(" No compile task");
1492 }
1493 st->cr();
1494 }
1495 }
1496
1497 void JavaThread::print() const { print_on(tty); }
1498
1499 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1500 st->print("%s", get_thread_name_string(buf, buflen));
1501 }
1502
1503 // Called by fatal error handler. The difference between this and
1504 // JavaThread::print() is that we can't grab lock or allocate memory.
1505 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1506 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1507 Thread* current = Thread::current_or_null_safe();
1508 assert(current != nullptr, "cannot be called by a detached thread");
1509 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1510 // Only access threadObj() if current thread is not a JavaThread
1511 // or if it is a JavaThread that can safely access oops.
1512 oop thread_obj = threadObj();
1513 if (thread_obj != nullptr) {
1514 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
1515 }
1516 }
1517 st->print(" [");
1518 st->print("%s", _get_thread_state_name(_thread_state));
1519 if (osthread()) {
1520 st->print(", id=%d", osthread()->thread_id());
1521 }
1522 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
1523 p2i(stack_end()), p2i(stack_base()));
1524 st->print("]");
1525
1526 ThreadsSMRSupport::print_info_on(this, st);
1527 return;
1528 }
1529
1530
1531 // Verification
1532
1533 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1534 // ignore if there is no stack
1535 if (!has_last_Java_frame()) return;
1536 // traverse the stack frames. Starts from top frame.
1537 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1538 frame* fr = fst.current();
1539 f(fr, fst.register_map());
1540 }
1541 }
1542
1543 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1544
1545 void JavaThread::verify() {
1546 // Verify oops in the thread.
1547 oops_do(&VerifyOopClosure::verify_oop, nullptr);
1548
1549 // Verify the stack frames.
1550 frames_do(frame_verify);
1551 }
1552
1553 // CR 6300358 (sub-CR 2137150)
1554 // Most callers of this method assume that it can't return null but a
1555 // thread may not have a name whilst it is in the process of attaching to
1556 // the VM - see CR 6412693, and there are places where a JavaThread can be
1557 // seen prior to having its threadObj set (e.g., JNI attaching threads and
1558 // if vm exit occurs during initialization). These cases can all be accounted
1559 // for such that this method never returns null.
1560 const char* JavaThread::name() const {
1561 if (Thread::is_JavaThread_protected(/* target */ this)) {
1562 // The target JavaThread is protected so get_thread_name_string() is safe:
1563 return get_thread_name_string();
1564 }
1565
1566 // The target JavaThread is not protected so we return the default:
1567 return Thread::name();
1568 }
1569
1570 // Returns a non-null representation of this thread's name, or a suitable
1571 // descriptive string if there is no set name.
1572 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1573 const char* name_str;
1574 #ifdef ASSERT
1575 Thread* current = Thread::current_or_null_safe();
1576 assert(current != nullptr, "cannot be called by a detached thread");
1577 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1578 // Only access threadObj() if current thread is not a JavaThread
1579 // or if it is a JavaThread that can safely access oops.
1580 #endif
1581 oop thread_obj = threadObj();
1582 if (thread_obj != nullptr) {
1583 oop name = java_lang_Thread::name(thread_obj);
1584 if (name != nullptr) {
1585 if (buf == nullptr) {
1586 name_str = java_lang_String::as_utf8_string(name);
1587 } else {
1588 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1589 }
1590 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1591 name_str = "<no-name - thread is attaching>";
1592 } else {
1593 name_str = "<un-named>";
1594 }
1595 } else {
1596 name_str = Thread::name();
1597 }
1598 #ifdef ASSERT
1599 } else {
1600 // Current JavaThread has exited...
1601 if (current == this) {
1602 // ... and is asking about itself:
1603 name_str = "<no-name - current JavaThread has exited>";
1604 } else {
1605 // ... and it can't safely determine this JavaThread's name so
1606 // use the default thread name.
1607 name_str = Thread::name();
1608 }
1609 }
1610 #endif
1611 assert(name_str != nullptr, "unexpected null thread name");
1612 return name_str;
1613 }
1614
1615 // Helper to extract the name from the thread oop for logging.
1616 const char* JavaThread::name_for(oop thread_obj) {
1617 assert(thread_obj != nullptr, "precondition");
1618 oop name = java_lang_Thread::name(thread_obj);
1619 const char* name_str;
1620 if (name != nullptr) {
1621 name_str = java_lang_String::as_utf8_string(name);
1622 } else {
1623 name_str = "<un-named>";
1624 }
1625 return name_str;
1626 }
1627
1628 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1629
1630 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1631 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1632 // Link Java Thread object <-> C++ Thread
1633
1634 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1635 // and put it into a new Handle. The Handle "thread_oop" can then
1636 // be used to pass the C++ thread object to other methods.
1637
1638 // Set the Java level thread object (jthread) field of the
1639 // new thread (a JavaThread *) to C++ thread object using the
1640 // "thread_oop" handle.
1641
1642 // Set the thread field (a JavaThread *) of the
1643 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1644
1645 Handle thread_oop(Thread::current(),
1646 JNIHandles::resolve_non_null(jni_thread));
1647 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1648 "must be initialized");
1649 set_threadOopHandles(thread_oop());
1650 java_lang_Thread::set_thread(thread_oop(), this);
1651
1652 if (prio == NoPriority) {
1653 prio = java_lang_Thread::priority(thread_oop());
1654 assert(prio != NoPriority, "A valid priority should be present");
1655 }
1656
1657 // Push the Java priority down to the native thread; needs Threads_lock
1658 Thread::set_priority(this, prio);
1659
1660 // Add the new thread to the Threads list and set it in motion.
1661 // We must have threads lock in order to call Threads::add.
1662 // It is crucial that we do not block before the thread is
1663 // added to the Threads list for if a GC happens, then the java_thread oop
1664 // will not be visited by GC.
1665 Threads::add(this);
1666 }
1667
1668 oop JavaThread::current_park_blocker() {
1669 // Support for JSR-166 locks
1670 oop thread_oop = threadObj();
1671 if (thread_oop != nullptr) {
1672 return java_lang_Thread::park_blocker(thread_oop);
1673 }
1674 return nullptr;
1675 }
1676
1677 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1678 // This is the external format, selecting the platform or vthread
1679 // as applicable, and allowing for a native-only stack.
1680 void JavaThread::print_jni_stack() {
1681 assert(this == JavaThread::current(), "Can't print stack of other threads");
1682 if (!has_last_Java_frame()) {
1683 ResourceMark rm(this);
1684 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
1685 if (buf == nullptr) {
1686 tty->print_cr("Unable to print native stack - out of memory");
1687 return;
1688 }
1689 frame f = os::current_frame();
1690 VMError::print_native_stack(tty, f, this, true /*print_source_info */,
1691 -1 /* max stack */, buf, O_BUFLEN);
1692 } else {
1693 print_active_stack_on(tty);
1694 }
1695 }
1696
1697 void JavaThread::print_stack_on(outputStream* st) {
1698 if (!has_last_Java_frame()) return;
1699
1700 Thread* current_thread = Thread::current();
1701 ResourceMark rm(current_thread);
1702 HandleMark hm(current_thread);
1703
1704 RegisterMap reg_map(this,
1705 RegisterMap::UpdateMap::include,
1706 RegisterMap::ProcessFrames::include,
1707 RegisterMap::WalkContinuation::skip);
1708 vframe* start_vf = platform_thread_last_java_vframe(®_map);
1709 int count = 0;
1710 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1711 if (f->is_java_frame()) {
1712 javaVFrame* jvf = javaVFrame::cast(f);
1713 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1714
1715 // Print out lock information
1716 if (JavaMonitorsInStackTrace) {
1717 jvf->print_lock_info_on(st, count);
1718 }
1719 } else {
1720 // Ignore non-Java frames
1721 }
1722
1723 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1724 count++;
1725 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1726 }
1727 }
1728
1729 void JavaThread::print_vthread_stack_on(outputStream* st) {
1730 assert(is_vthread_mounted(), "Caller should have checked this");
1731 assert(has_last_Java_frame(), "must be");
1732
1733 Thread* current_thread = Thread::current();
1734 ResourceMark rm(current_thread);
1735 HandleMark hm(current_thread);
1736
1737 RegisterMap reg_map(this,
1738 RegisterMap::UpdateMap::include,
1739 RegisterMap::ProcessFrames::include,
1740 RegisterMap::WalkContinuation::include);
1741 ContinuationEntry* cont_entry = last_continuation();
1742 vframe* start_vf = last_java_vframe(®_map);
1743 int count = 0;
1744 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1745 // Watch for end of vthread stack
1746 if (Continuation::is_continuation_enterSpecial(f->fr())) {
1747 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), "");
1748 if (cont_entry->is_virtual_thread()) {
1749 break;
1750 }
1751 cont_entry = cont_entry->parent();
1752 }
1753 if (f->is_java_frame()) {
1754 javaVFrame* jvf = javaVFrame::cast(f);
1755 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1756
1757 // Print out lock information
1758 if (JavaMonitorsInStackTrace) {
1759 jvf->print_lock_info_on(st, count);
1760 }
1761 } else {
1762 // Ignore non-Java frames
1763 }
1764
1765 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1766 count++;
1767 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1768 }
1769 }
1770
1771 void JavaThread::print_active_stack_on(outputStream* st) {
1772 if (is_vthread_mounted()) {
1773 print_vthread_stack_on(st);
1774 } else {
1775 print_stack_on(st);
1776 }
1777 }
1778
1779 #if INCLUDE_JVMTI
1780 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1781 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1782 set_jvmti_vthread(thread_oop);
1783
1784 // unbind current JvmtiThreadState from JavaThread
1785 JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1786
1787 // bind new JvmtiThreadState to JavaThread
1788 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1789
1790 return jvmti_thread_state();
1791 }
1792 #endif
1793
1794 // JVMTI PopFrame support
1795 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1796 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments");
1797 if (in_bytes(size_in_bytes) != 0) {
1798 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1799 _popframe_preserved_args_size = in_bytes(size_in_bytes);
1800 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1801 }
1802 }
1803
1804 void* JavaThread::popframe_preserved_args() {
1805 return _popframe_preserved_args;
1806 }
1807
1808 ByteSize JavaThread::popframe_preserved_args_size() {
1809 return in_ByteSize(_popframe_preserved_args_size);
1810 }
1811
1812 WordSize JavaThread::popframe_preserved_args_size_in_words() {
1813 int sz = in_bytes(popframe_preserved_args_size());
1814 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1815 return in_WordSize(sz / wordSize);
1816 }
1817
1818 void JavaThread::popframe_free_preserved_args() {
1819 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice");
1820 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1821 _popframe_preserved_args = nullptr;
1822 _popframe_preserved_args_size = 0;
1823 }
1824
1825 #ifndef PRODUCT
1826
1827 void JavaThread::trace_frames() {
1828 tty->print_cr("[Describe stack]");
1829 int frame_no = 1;
1830 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1831 tty->print(" %d. ", frame_no++);
1832 fst.current()->print_value_on(tty, this);
1833 tty->cr();
1834 }
1835 }
1836
1837 class PrintAndVerifyOopClosure: public OopClosure {
1838 protected:
1839 template <class T> inline void do_oop_work(T* p) {
1840 oop obj = RawAccess<>::oop_load(p);
1841 if (obj == nullptr) return;
1842 tty->print(INTPTR_FORMAT ": ", p2i(p));
1843 if (oopDesc::is_oop_or_null(obj)) {
1844 if (obj->is_objArray()) {
1845 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1846 } else {
1847 obj->print();
1848 }
1849 } else {
1850 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1851 }
1852 tty->cr();
1853 }
1854 public:
1855 virtual void do_oop(oop* p) { do_oop_work(p); }
1856 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1857 };
1858
1859 #ifdef ASSERT
1860 // Print or validate the layout of stack frames
1861 void JavaThread::print_frame_layout(int depth, bool validate_only) {
1862 ResourceMark rm;
1863 PreserveExceptionMark pm(this);
1864 FrameValues values;
1865 int frame_no = 0;
1866 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1867 fst.current()->describe(values, ++frame_no, fst.register_map());
1868 if (depth == frame_no) break;
1869 }
1870 Continuation::describe(values);
1871 if (validate_only) {
1872 values.validate();
1873 } else {
1874 tty->print_cr("[Describe stack layout]");
1875 values.print(this);
1876 }
1877 }
1878 #endif
1879
1880 void JavaThread::trace_stack_from(vframe* start_vf) {
1881 ResourceMark rm;
1882 int vframe_no = 1;
1883 for (vframe* f = start_vf; f; f = f->sender()) {
1884 if (f->is_java_frame()) {
1885 javaVFrame::cast(f)->print_activation(vframe_no++);
1886 } else {
1887 f->print();
1888 }
1889 if (vframe_no > StackPrintLimit) {
1890 tty->print_cr("...<more frames>...");
1891 return;
1892 }
1893 }
1894 }
1895
1896
1897 void JavaThread::trace_stack() {
1898 if (!has_last_Java_frame()) return;
1899 Thread* current_thread = Thread::current();
1900 ResourceMark rm(current_thread);
1901 HandleMark hm(current_thread);
1902 RegisterMap reg_map(this,
1903 RegisterMap::UpdateMap::include,
1904 RegisterMap::ProcessFrames::include,
1905 RegisterMap::WalkContinuation::skip);
1906 trace_stack_from(last_java_vframe(®_map));
1907 }
1908
1909
1910 #endif // PRODUCT
1911
1912 void JavaThread::inc_held_monitor_count(int i, bool jni) {
1913 #ifdef SUPPORT_MONITOR_COUNT
1914 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count);
1915 _held_monitor_count += i;
1916 if (jni) {
1917 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count);
1918 _jni_monitor_count += i;
1919 }
1920 #endif
1921 }
1922
1923 void JavaThread::dec_held_monitor_count(int i, bool jni) {
1924 #ifdef SUPPORT_MONITOR_COUNT
1925 _held_monitor_count -= i;
1926 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count);
1927 if (jni) {
1928 _jni_monitor_count -= i;
1929 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count);
1930 }
1931 #endif
1932 }
1933
1934 frame JavaThread::vthread_last_frame() {
1935 assert (is_vthread_mounted(), "Virtual thread not mounted");
1936 return last_frame();
1937 }
1938
1939 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
1940 const ContinuationEntry* entry = vthread_continuation();
1941 guarantee (entry != nullptr, "Not a carrier thread");
1942 frame f = entry->to_frame();
1943 if (reg_map->process_frames()) {
1944 entry->flush_stack_processing(this);
1945 }
1946 entry->update_register_map(reg_map);
1947 return f.sender(reg_map);
1948 }
1949
1950 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
1951 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
1952 }
1953
1954 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
1955 assert(reg_map != nullptr, "a map must be given");
1956 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
1957 if (vf->is_java_frame()) return javaVFrame::cast(vf);
1958 }
1959 return nullptr;
1960 }
1961
1962 Klass* JavaThread::security_get_caller_class(int depth) {
1963 ResetNoHandleMark rnhm;
1964 HandleMark hm(Thread::current());
1965
1966 vframeStream vfst(this);
1967 vfst.security_get_caller_frame(depth);
1968 if (!vfst.at_end()) {
1969 return vfst.method()->method_holder();
1970 }
1971 return nullptr;
1972 }
1973
1974 // java.lang.Thread.sleep support
1975 // Returns true if sleep time elapsed as expected, and false
1976 // if the thread was interrupted.
1977 bool JavaThread::sleep(jlong millis) {
1978 assert(this == Thread::current(), "thread consistency check");
1979
1980 ParkEvent * const slp = this->_SleepEvent;
1981 // Because there can be races with thread interruption sending an unpark()
1982 // to the event, we explicitly reset it here to avoid an immediate return.
1983 // The actual interrupt state will be checked before we park().
1984 slp->reset();
1985 // Thread interruption establishes a happens-before ordering in the
1986 // Java Memory Model, so we need to ensure we synchronize with the
1987 // interrupt state.
1988 OrderAccess::fence();
1989
1990 jlong prevtime = os::javaTimeNanos();
1991
1992 for (;;) {
1993 // interruption has precedence over timing out
1994 if (this->is_interrupted(true)) {
1995 return false;
1996 }
1997
1998 if (millis <= 0) {
1999 return true;
2000 }
2001
2002 {
2003 ThreadBlockInVM tbivm(this);
2004 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2005 slp->park(millis);
2006 }
2007
2008 // Update elapsed time tracking
2009 jlong newtime = os::javaTimeNanos();
2010 if (newtime - prevtime < 0) {
2011 // time moving backwards, should only happen if no monotonic clock
2012 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2013 assert(false,
2014 "unexpected time moving backwards detected in JavaThread::sleep()");
2015 } else {
2016 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2017 }
2018 prevtime = newtime;
2019 }
2020 }
2021
2022 // Last thread running calls java.lang.Shutdown.shutdown()
2023 void JavaThread::invoke_shutdown_hooks() {
2024 HandleMark hm(this);
2025
2026 // We could get here with a pending exception, if so clear it now or
2027 // it will cause MetaspaceShared::link_shared_classes to
2028 // fail for dynamic dump.
2029 if (this->has_pending_exception()) {
2030 this->clear_pending_exception();
2031 }
2032
2033 #if INCLUDE_CDS
2034 // Link all classes for dynamic CDS dumping before vm exit.
2035 // Same operation is being done in JVM_BeforeHalt for handling the
2036 // case where the application calls System.exit().
2037 if (DynamicArchive::should_dump_at_vm_exit()) {
2038 DynamicArchive::prepare_for_dump_at_exit();
2039 }
2040 #endif
2041
2042 EXCEPTION_MARK;
2043 Klass* shutdown_klass =
2044 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
2045 THREAD);
2046 if (shutdown_klass != nullptr) {
2047 // SystemDictionary::resolve_or_null will return null if there was
2048 // an exception. If we cannot load the Shutdown class, just don't
2049 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
2050 // won't be run. Note that if a shutdown hook was registered,
2051 // the Shutdown class would have already been loaded
2052 // (Runtime.addShutdownHook will load it).
2053 JavaValue result(T_VOID);
2054 JavaCalls::call_static(&result,
2055 shutdown_klass,
2056 vmSymbols::shutdown_name(),
2057 vmSymbols::void_method_signature(),
2058 THREAD);
2059 }
2060 CLEAR_PENDING_EXCEPTION;
2061 }
2062
2063 #ifndef PRODUCT
2064 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
2065 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
2066 }
2067 #endif
2068
2069 // Helper function to create the java.lang.Thread object for a
2070 // VM-internal thread. The thread will have the given name, and be
2071 // a member of the "system" ThreadGroup.
2072 Handle JavaThread::create_system_thread_object(const char* name,
2073 bool is_visible, TRAPS) {
2074 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2075
2076 // Initialize thread_oop to put it into the system threadGroup.
2077 // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2078 Handle thread_group(THREAD, Universe::system_thread_group());
2079 Handle thread_oop =
2080 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2081 vmSymbols::threadgroup_string_void_signature(),
2082 thread_group,
2083 string,
2084 CHECK_NH);
2085
2086 return thread_oop;
2087 }
2088
2089 // Starts the target JavaThread as a daemon of the given priority, and
2090 // bound to the given java.lang.Thread instance.
2091 // The Threads_lock is held for the duration.
2092 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2093 Handle thread_oop, ThreadPriority prio) {
2094
2095 assert(target->osthread() != nullptr, "target thread is not properly initialized");
2096
2097 MutexLocker mu(current, Threads_lock);
2098
2099 // Initialize the fields of the thread_oop first.
2100
2101 java_lang_Thread::set_thread(thread_oop(), target); // isAlive == true now
2102
2103 if (prio != NoPriority) {
2104 java_lang_Thread::set_priority(thread_oop(), prio);
2105 // Note: we don't call os::set_priority here. Possibly we should,
2106 // else all threads should call it themselves when they first run.
2107 }
2108
2109 java_lang_Thread::set_daemon(thread_oop());
2110
2111 // Now bind the thread_oop to the target JavaThread.
2112 target->set_threadOopHandles(thread_oop());
2113
2114 Threads::add(target); // target is now visible for safepoint/handshake
2115 Thread::start(target);
2116 }
2117
2118 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2119 // At this point it may be possible that no osthread was created for the
2120 // JavaThread due to lack of resources. However, since this must work
2121 // for critical system threads just check and abort if this fails.
2122 if (thread->osthread() == nullptr) {
2123 // This isn't really an OOM condition, but historically this is what
2124 // we report.
2125 vm_exit_during_initialization("java.lang.OutOfMemoryError",
2126 os::native_thread_creation_failed_msg());
2127 }
2128 }
2129
2130 // Deferred OopHandle release support.
2131
2132 class OopHandleList : public CHeapObj<mtInternal> {
2133 static const int _count = 4;
2134 OopHandle _handles[_count];
2135 OopHandleList* _next;
2136 int _index;
2137 public:
2138 OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2139 void add(OopHandle h) {
2140 assert(_index < _count, "too many additions");
2141 _handles[_index++] = h;
2142 }
2143 ~OopHandleList() {
2144 assert(_index == _count, "usage error");
2145 for (int i = 0; i < _index; i++) {
2146 _handles[i].release(JavaThread::thread_oop_storage());
2147 }
2148 }
2149 OopHandleList* next() const { return _next; }
2150 };
2151
2152 OopHandleList* JavaThread::_oop_handle_list = nullptr;
2153
2154 // Called by the ServiceThread to do the work of releasing
2155 // the OopHandles.
2156 void JavaThread::release_oop_handles() {
2157 OopHandleList* list;
2158 {
2159 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2160 list = _oop_handle_list;
2161 _oop_handle_list = nullptr;
2162 }
2163 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2164
2165 while (list != nullptr) {
2166 OopHandleList* l = list;
2167 list = l->next();
2168 delete l;
2169 }
2170 }
2171
2172 // Add our OopHandles for later release.
2173 void JavaThread::add_oop_handles_for_release() {
2174 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2175 OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2176 new_head->add(_threadObj);
2177 new_head->add(_vthread);
2178 new_head->add(_jvmti_vthread);
2179 new_head->add(_scopedValueCache);
2180 _oop_handle_list = new_head;
2181 Service_lock->notify_all();
2182 }