1 /*
2 * Copyright (c) 1997, 2025, 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 "cds/dynamicArchive.hpp"
27 #include "ci/ciEnv.hpp"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "classfile/javaThreadStatus.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmClasses.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "code/codeCache.hpp"
34 #include "code/scopeDesc.hpp"
35 #include "compiler/compilerThread.hpp"
36 #include "compiler/compileTask.hpp"
37 #include "gc/shared/oopStorage.hpp"
38 #include "gc/shared/oopStorageSet.hpp"
39 #include "gc/shared/tlab_globals.hpp"
40 #include "jfr/jfrEvents.hpp"
41 #include "jvm.h"
42 #include "jvmtifiles/jvmtiEnv.hpp"
43 #include "logging/log.hpp"
44 #include "logging/logAsyncWriter.hpp"
45 #include "logging/logStream.hpp"
46 #include "memory/allocation.inline.hpp"
47 #include "memory/iterator.hpp"
48 #include "memory/universe.hpp"
49 #include "oops/access.inline.hpp"
50 #include "oops/instanceKlass.hpp"
51 #include "oops/klass.inline.hpp"
52 #include "oops/oop.inline.hpp"
53 #include "oops/oopHandle.inline.hpp"
54 #include "oops/verifyOopClosure.hpp"
55 #include "prims/jvm_misc.hpp"
56 #include "prims/jvmtiDeferredUpdates.hpp"
57 #include "prims/jvmtiExport.hpp"
58 #include "prims/jvmtiThreadState.inline.hpp"
59 #include "runtime/atomicAccess.hpp"
60 #include "runtime/continuation.hpp"
61 #include "runtime/continuationEntry.inline.hpp"
62 #include "runtime/continuationHelper.inline.hpp"
63 #include "runtime/deoptimization.hpp"
64 #include "runtime/frame.inline.hpp"
65 #include "runtime/handles.inline.hpp"
66 #include "runtime/handshake.hpp"
67 #include "runtime/interfaceSupport.inline.hpp"
68 #include "runtime/java.hpp"
69 #include "runtime/javaCalls.hpp"
70 #include "runtime/javaThread.inline.hpp"
71 #include "runtime/jniHandles.inline.hpp"
72 #include "runtime/lockStack.inline.hpp"
73 #include "runtime/mutexLocker.hpp"
74 #include "runtime/orderAccess.hpp"
75 #include "runtime/os.inline.hpp"
76 #include "runtime/osThread.hpp"
77 #include "runtime/safepoint.hpp"
78 #include "runtime/safepointMechanism.inline.hpp"
79 #include "runtime/safepointVerifiers.hpp"
80 #include "runtime/serviceThread.hpp"
81 #include "runtime/stackFrameStream.inline.hpp"
82 #include "runtime/stackWatermarkSet.hpp"
83 #include "runtime/synchronizer.hpp"
84 #include "runtime/threadIdentifier.hpp"
85 #include "runtime/threadSMR.inline.hpp"
86 #include "runtime/threadStatisticalInfo.hpp"
87 #include "runtime/threadWXSetters.inline.hpp"
88 #include "runtime/timer.hpp"
89 #include "runtime/timerTrace.hpp"
90 #include "runtime/vframe.inline.hpp"
91 #include "runtime/vframe_hp.hpp"
92 #include "runtime/vframeArray.hpp"
93 #include "runtime/vmOperations.hpp"
94 #include "runtime/vmThread.hpp"
95 #include "services/threadService.hpp"
96 #include "utilities/copy.hpp"
97 #include "utilities/defaultStream.hpp"
98 #include "utilities/dtrace.hpp"
99 #include "utilities/events.hpp"
100 #include "utilities/macros.hpp"
101 #include "utilities/nativeStackPrinter.hpp"
102 #include "utilities/preserveException.hpp"
103 #include "utilities/spinYield.hpp"
104 #include "utilities/vmError.hpp"
105 #if INCLUDE_JVMCI
106 #include "jvmci/jvmci.hpp"
107 #include "jvmci/jvmciEnv.hpp"
108 #endif
109 #if INCLUDE_JFR
110 #include "jfr/jfr.hpp"
111 #endif
112
113 // Set by os layer.
114 size_t JavaThread::_stack_size_at_create = 0;
115
116 #ifdef DTRACE_ENABLED
117
118 // Only bother with this argument setup if dtrace is available
119
120 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
121 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
122
123 #define DTRACE_THREAD_PROBE(probe, javathread) \
124 if (!javathread->is_aot_thread()) { \
125 ResourceMark rm(this); \
126 int len = 0; \
127 const char* name = (javathread)->name(); \
128 len = strlen(name); \
129 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
130 (char *) name, len, \
131 java_lang_Thread::thread_id((javathread)->threadObj()), \
132 (uintptr_t) (javathread)->osthread()->thread_id(), \
133 java_lang_Thread::is_daemon((javathread)->threadObj())); \
134 }
135
136 #else // ndef DTRACE_ENABLED
137
138 #define DTRACE_THREAD_PROBE(probe, javathread)
139
140 #endif // ndef DTRACE_ENABLED
141
142 void JavaThread::smr_delete() {
143 if (_on_thread_list) {
144 ThreadsSMRSupport::smr_delete(this);
145 } else {
146 delete this;
147 }
148 }
149
150 // Initialized by VMThread at vm_global_init
151 OopStorage* JavaThread::_thread_oop_storage = nullptr;
152
153 OopStorage* JavaThread::thread_oop_storage() {
154 assert(_thread_oop_storage != nullptr, "not yet initialized");
155 return _thread_oop_storage;
156 }
157
158 void JavaThread::set_threadOopHandles(oop p) {
159 assert(_thread_oop_storage != nullptr, "not yet initialized");
160 _threadObj = OopHandle(_thread_oop_storage, p);
161 _vthread = OopHandle(_thread_oop_storage, p);
162 _jvmti_vthread = OopHandle(_thread_oop_storage, p->is_a(vmClasses::BoundVirtualThread_klass()) ? p : nullptr);
163 _scopedValueCache = OopHandle(_thread_oop_storage, nullptr);
164 }
165
166 oop JavaThread::threadObj() const {
167 // Ideally we would verify the current thread is oop_safe when this is called, but as we can
168 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That
169 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS.
170 // Instead callers must verify oop safe access.
171 return _threadObj.resolve();
172 }
173
174 oop JavaThread::vthread() const {
175 return _vthread.resolve();
176 }
177
178 void JavaThread::set_vthread(oop p) {
179 assert(_thread_oop_storage != nullptr, "not yet initialized");
180 _vthread.replace(p);
181 }
182
183 oop JavaThread::jvmti_vthread() const {
184 return _jvmti_vthread.resolve();
185 }
186
187 void JavaThread::set_jvmti_vthread(oop p) {
188 assert(_thread_oop_storage != nullptr, "not yet initialized");
189 _jvmti_vthread.replace(p);
190 }
191
192 // If there is a virtual thread mounted then return vthread() oop.
193 // Otherwise, return threadObj().
194 oop JavaThread::vthread_or_thread() const {
195 oop result = vthread();
196 if (result == nullptr) {
197 result = threadObj();
198 }
199 return result;
200 }
201
202 oop JavaThread::scopedValueCache() const {
203 return _scopedValueCache.resolve();
204 }
205
206 void JavaThread::set_scopedValueCache(oop p) {
207 if (!_scopedValueCache.is_empty()) { // i.e. if the OopHandle has been allocated
208 _scopedValueCache.replace(p);
209 } else {
210 assert(p == nullptr, "not yet initialized");
211 }
212 }
213
214 void JavaThread::clear_scopedValueBindings() {
215 set_scopedValueCache(nullptr);
216 oop vthread_oop = vthread();
217 // vthread may be null here if we get a VM error during startup,
218 // before the java.lang.Thread instance has been created.
219 if (vthread_oop != nullptr) {
220 java_lang_Thread::clear_scopedValueBindings(vthread_oop);
221 }
222 }
223
224 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
225 bool daemon, TRAPS) {
226 assert(thread_group.not_null(), "thread group should be specified");
227 assert(threadObj() == nullptr, "should only create Java thread object once");
228
229 InstanceKlass* ik = vmClasses::Thread_klass();
230 assert(ik->is_initialized(), "must be");
231 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
232
233 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
234 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
235 // constructor calls Thread.current(), which must be set here.
236 java_lang_Thread::set_thread(thread_oop(), this);
237 set_threadOopHandles(thread_oop());
238
239 JavaValue result(T_VOID);
240 if (thread_name != nullptr) {
241 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
242 // Thread gets assigned specified name and null target
243 JavaCalls::call_special(&result,
244 thread_oop,
245 ik,
246 vmSymbols::object_initializer_name(),
247 vmSymbols::threadgroup_string_void_signature(),
248 thread_group,
249 name,
250 CHECK);
251 } else {
252 // Thread gets assigned name "Thread-nnn" and null target
253 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
254 JavaCalls::call_special(&result,
255 thread_oop,
256 ik,
257 vmSymbols::object_initializer_name(),
258 vmSymbols::threadgroup_runnable_void_signature(),
259 thread_group,
260 Handle(),
261 CHECK);
262 }
263
264 os::set_priority(this, NormPriority);
265
266 if (daemon) {
267 java_lang_Thread::set_daemon(thread_oop());
268 }
269 }
270
271 // ======= JavaThread ========
272
273 #if INCLUDE_JVMCI
274
275 jlong* JavaThread::_jvmci_old_thread_counters;
276
277 static bool jvmci_counters_include(JavaThread* thread) {
278 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
279 }
280
281 void JavaThread::collect_counters(jlong* array, int length) {
282 assert(length == JVMCICounterSize, "wrong value");
283 for (int i = 0; i < length; i++) {
284 array[i] = _jvmci_old_thread_counters[i];
285 }
286 for (JavaThread* tp : ThreadsListHandle()) {
287 if (jvmci_counters_include(tp)) {
288 for (int i = 0; i < length; i++) {
289 array[i] += tp->_jvmci_counters[i];
290 }
291 }
292 }
293 }
294
295 // Attempt to enlarge the array for per thread counters.
296 static jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
297 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
298 if (new_counters == nullptr) {
299 return nullptr;
300 }
301 if (old_counters == nullptr) {
302 old_counters = new_counters;
303 memset(old_counters, 0, sizeof(jlong) * new_size);
304 } else {
305 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
306 new_counters[i] = old_counters[i];
307 }
308 if (new_size > current_size) {
309 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
310 }
311 FREE_C_HEAP_ARRAY(jlong, old_counters);
312 }
313 return new_counters;
314 }
315
316 // Attempt to enlarge the array for per thread counters.
317 bool JavaThread::resize_counters(int current_size, int new_size) {
318 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
319 if (new_counters == nullptr) {
320 return false;
321 } else {
322 _jvmci_counters = new_counters;
323 return true;
324 }
325 }
326
327 class VM_JVMCIResizeCounters : public VM_Operation {
328 private:
329 int _new_size;
330 bool _failed;
331
332 public:
333 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
334 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
335 bool allow_nested_vm_operations() const { return true; }
336 void doit() {
337 // Resize the old thread counters array
338 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
339 if (new_counters == nullptr) {
340 _failed = true;
341 return;
342 } else {
343 JavaThread::_jvmci_old_thread_counters = new_counters;
344 }
345
346 // Now resize each threads array
347 for (JavaThread* tp : ThreadsListHandle()) {
348 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
349 _failed = true;
350 break;
351 }
352 }
353 if (!_failed) {
354 JVMCICounterSize = _new_size;
355 }
356 }
357
358 bool failed() { return _failed; }
359 };
360
361 bool JavaThread::resize_all_jvmci_counters(int new_size) {
362 VM_JVMCIResizeCounters op(new_size);
363 VMThread::execute(&op);
364 return !op.failed();
365 }
366
367 #endif // INCLUDE_JVMCI
368
369 #ifdef ASSERT
370 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
371 void JavaThread::check_possible_safepoint() {
372 if (_no_safepoint_count > 0) {
373 print_owned_locks();
374 assert(false, "Possible safepoint reached by thread that does not allow it");
375 }
376 #ifdef CHECK_UNHANDLED_OOPS
377 // Clear unhandled oops in JavaThreads so we get a crash right away.
378 clear_unhandled_oops();
379 #endif // CHECK_UNHANDLED_OOPS
380
381 // Macos/aarch64 should be in the right state for safepoint (e.g.
382 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely
383 // happens in practice, making such issues hard to find and reproduce.
384 #if defined(__APPLE__) && defined(AARCH64)
385 if (AssertWXAtThreadSync) {
386 assert_wx_state(WXWrite);
387 }
388 #endif
389 }
390
391 void JavaThread::check_for_valid_safepoint_state() {
392 // Don't complain if running a debugging command.
393 if (DebuggingContext::is_enabled()) return;
394
395 // Check NoSafepointVerifier, which is implied by locks taken that can be
396 // shared with the VM thread. This makes sure that no locks with allow_vm_block
397 // are held.
398 check_possible_safepoint();
399
400 if (thread_state() != _thread_in_vm) {
401 fatal("LEAF method calling lock?");
402 }
403
404 if (GCALotAtAllSafepoints) {
405 // We could enter a safepoint here and thus have a gc
406 InterfaceSupport::check_gc_alot();
407 }
408 }
409 #endif // ASSERT
410
411 // A JavaThread is a normal Java thread
412
413 JavaThread::JavaThread(MemTag mem_tag) :
414 Thread(mem_tag),
415 // Initialize fields
416 _on_thread_list(false),
417 DEBUG_ONLY(_java_call_counter(0) COMMA)
418 _entry_point(nullptr),
419 _deopt_mark(nullptr),
420 _deopt_nmethod(nullptr),
421 _vframe_array_head(nullptr),
422 _vframe_array_last(nullptr),
423 _jvmti_deferred_updates(nullptr),
424 _callee_target(nullptr),
425 _vm_result_oop(nullptr),
426 _vm_result_metadata(nullptr),
427
428 _current_pending_monitor(nullptr),
429 _current_pending_monitor_is_from_java(true),
430 _current_waiting_monitor(nullptr),
431 _active_handles(nullptr),
432 _free_handle_block(nullptr),
433 _monitor_owner_id(0),
434
435 _suspend_flags(0),
436
437 _thread_state(_thread_new),
438 _saved_exception_pc(nullptr),
439 #ifdef ASSERT
440 _no_safepoint_count(0),
441 _visited_for_critical_count(false),
442 #endif
443
444 _terminated(_not_terminated),
445 _in_deopt_handler(0),
446 _doing_unsafe_access(false),
447 _throwing_unsafe_access_error(false),
448 _do_not_unlock_if_synchronized(false),
449 #if INCLUDE_JVMTI
450 _carrier_thread_suspended(false),
451 _is_in_VTMS_transition(false),
452 _is_disable_suspend(false),
453 _is_in_java_upcall(false),
454 _VTMS_transition_mark(false),
455 _on_monitor_waited_event(false),
456 _contended_entered_monitor(nullptr),
457 #ifdef ASSERT
458 _is_VTMS_transition_disabler(false),
459 #endif
460 #endif
461 _jni_attach_state(_not_attaching_via_jni),
462 _is_in_internal_oome_mark(false),
463 #if INCLUDE_JVMCI
464 _pending_deoptimization(-1),
465 _pending_monitorenter(false),
466 _pending_transfer_to_interpreter(false),
467 _pending_failed_speculation(0),
468 _jvmci{nullptr},
469 _libjvmci_runtime(nullptr),
470 _jvmci_counters(nullptr),
471 _jvmci_reserved0(0),
472 _jvmci_reserved1(0),
473 _jvmci_reserved_oop0(nullptr),
474 _live_nmethod(nullptr),
475 #endif // INCLUDE_JVMCI
476
477 _exception_oop(oop()),
478 _exception_pc(nullptr),
479 _exception_handler_pc(nullptr),
480
481 _jni_active_critical(0),
482 _pending_jni_exception_check_fn(nullptr),
483 _depth_first_number(0),
484
485 // JVMTI PopFrame support
486 _popframe_condition(popframe_inactive),
487 _frames_to_pop_failed_realloc(0),
488
489 _cont_entry(nullptr),
490 _cont_fastpath(nullptr),
491 _cont_fastpath_thread_state(1),
492 _unlocked_inflated_monitor(nullptr),
493
494 _can_call_java(true),
495
496 _preempt_alternate_return(nullptr),
497 _preemption_cancelled(false),
498 _pending_interrupted_exception(false),
499 _at_preemptable_init(false),
500 DEBUG_ONLY(_preempt_init_klass(nullptr) COMMA)
501 DEBUG_ONLY(_interp_at_preemptable_vmcall_cnt(0) COMMA)
502 DEBUG_ONLY(_interp_redoing_vm_call(false) COMMA)
503
504 _handshake(this),
505 _suspend_resume_manager(this, &_handshake._lock),
506
507 _popframe_preserved_args(nullptr),
508 _popframe_preserved_args_size(0),
509
510 _jvmti_thread_state(nullptr),
511 _interp_only_mode(0),
512 _should_post_on_exceptions_flag(JNI_FALSE),
513 _thread_stat(new ThreadStatistics()),
514
515 _parker(),
516
517 _class_to_be_initialized(nullptr),
518 _class_being_initialized(nullptr),
519
520 _SleepEvent(ParkEvent::Allocate(this)),
521
522 #if INCLUDE_JFR
523 _last_freeze_fail_result(freeze_ok),
524 #endif
525
526 _lock_stack(this),
527 _om_cache(this) {
528 set_jni_functions(jni_functions());
529
530 #if INCLUDE_JVMCI
531 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
532 if (JVMCICounterSize > 0) {
533 resize_counters(0, (int) JVMCICounterSize);
534 }
535 #endif // INCLUDE_JVMCI
536
537 // Setup safepoint state info for this thread
538 ThreadSafepointState::create(this);
539
540 SafepointMechanism::initialize_header(this);
541
542 set_requires_cross_modify_fence(false);
543
544 pd_initialize();
545 }
546
547 JavaThread* JavaThread::create_attaching_thread() {
548 JavaThread* jt = new JavaThread();
549 jt->_jni_attach_state = _attaching_via_jni;
550 return jt;
551 }
552
553 // interrupt support
554
555 void JavaThread::interrupt() {
556 // All callers should have 'this' thread protected by a
557 // ThreadsListHandle so that it cannot terminate and deallocate
558 // itself.
559 DEBUG_ONLY(check_for_dangling_thread_pointer(this);)
560
561 // For Windows _interrupt_event
562 WINDOWS_ONLY(osthread()->set_interrupted(true);)
563
564 // For Thread.sleep
565 _SleepEvent->unpark();
566
567 // For JSR166 LockSupport.park
568 parker()->unpark();
569
570 // For ObjectMonitor and JvmtiRawMonitor
571 _ParkEvent->unpark();
572 }
573
574 bool JavaThread::is_interrupted(bool clear_interrupted) {
575 DEBUG_ONLY(check_for_dangling_thread_pointer(this);)
576
577 if (_threadObj.peek() == nullptr) {
578 // If there is no j.l.Thread then it is impossible to have
579 // been interrupted. We can find null during VM initialization
580 // or when a JNI thread is still in the process of attaching.
581 // In such cases this must be the current thread.
582 assert(this == Thread::current(), "invariant");
583 return false;
584 }
585
586 bool interrupted = java_lang_Thread::interrupted(threadObj());
587
588 // NOTE that since there is no "lock" around the interrupt and
589 // is_interrupted operations, there is the possibility that the
590 // interrupted flag will be "false" but that the
591 // low-level events will be in the signaled state. This is
592 // intentional. The effect of this is that Object.wait() and
593 // LockSupport.park() will appear to have a spurious wakeup, which
594 // is allowed and not harmful, and the possibility is so rare that
595 // it is not worth the added complexity to add yet another lock.
596 // For the sleep event an explicit reset is performed on entry
597 // to JavaThread::sleep, so there is no early return. It has also been
598 // recommended not to put the interrupted flag into the "event"
599 // structure because it hides the issue.
600 // Also, because there is no lock, we must only clear the interrupt
601 // state if we are going to report that we were interrupted; otherwise
602 // an interrupt that happens just after we read the field would be lost.
603 if (interrupted && clear_interrupted) {
604 assert(this == Thread::current(), "only the current thread can clear");
605 java_lang_Thread::set_interrupted(threadObj(), false);
606 WINDOWS_ONLY(osthread()->set_interrupted(false);)
607 }
608 return interrupted;
609 }
610
611 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
612 // the Java code in Object::wait which are not present in RawMonitorWait.
613 bool JavaThread::get_and_clear_interrupted() {
614 if (!is_interrupted(false)) {
615 return false;
616 }
617 oop thread_oop = vthread_or_thread();
618 bool is_virtual = java_lang_VirtualThread::is_instance(thread_oop);
619
620 if (!is_virtual) {
621 return is_interrupted(true);
622 }
623 // Virtual thread: clear interrupt status for both virtual and
624 // carrier threads under the interruptLock protection.
625 JavaThread* current = JavaThread::current();
626 HandleMark hm(current);
627 Handle thread_h(current, thread_oop);
628 ObjectLocker lock(Handle(current, java_lang_Thread::interrupt_lock(thread_h())), current);
629
630 // re-check the interrupt status under the interruptLock protection
631 bool interrupted = java_lang_Thread::interrupted(thread_h());
632
633 if (interrupted) {
634 assert(this == Thread::current(), "only the current thread can clear");
635 java_lang_Thread::set_interrupted(thread_h(), false); // clear for virtual
636 java_lang_Thread::set_interrupted(threadObj(), false); // clear for carrier
637 WINDOWS_ONLY(osthread()->set_interrupted(false);)
638 }
639 return interrupted;
640 }
641
642 void JavaThread::block_if_vm_exited() {
643 if (_terminated == _vm_exited) {
644 // _vm_exited is set at safepoint, and Threads_lock is never released
645 // so we will block here forever.
646 // Here we can be doing a jump from a safe state to an unsafe state without
647 // proper transition, but it happens after the final safepoint has begun so
648 // this jump won't cause any safepoint problems.
649 set_thread_state(_thread_in_vm);
650 Threads_lock->lock();
651 ShouldNotReachHere();
652 }
653 }
654
655 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz, MemTag mem_tag) : JavaThread(mem_tag) {
656 set_entry_point(entry_point);
657 // Create the native thread itself.
658 // %note runtime_23
659 os::ThreadType thr_type = os::java_thread;
660 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
661 os::java_thread;
662 os::create_thread(this, thr_type, stack_sz);
663 // The _osthread may be null here because we ran out of memory (too many threads active).
664 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
665 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
666 // the exception consists of creating the exception object & initializing it, initialization
667 // will leave the VM via a JavaCall and then all locks must be unlocked).
668 //
669 // The thread is still suspended when we reach here. Thread must be explicit started
670 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
671 // by calling Threads:add. The reason why this is not done here, is because the thread
672 // object must be fully initialized (take a look at JVM_Start)
673 }
674
675 JavaThread::~JavaThread() {
676
677 // Enqueue OopHandles for release by the service thread.
678 add_oop_handles_for_release();
679
680 // Return the sleep event to the free list
681 ParkEvent::Release(_SleepEvent);
682 _SleepEvent = nullptr;
683
684 // Free any remaining previous UnrollBlock
685 vframeArray* old_array = vframe_array_last();
686
687 if (old_array != nullptr) {
688 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
689 old_array->set_unroll_block(nullptr);
690 delete old_info;
691 delete old_array;
692 }
693
694 JvmtiDeferredUpdates* updates = deferred_updates();
695 if (updates != nullptr) {
696 // This can only happen if thread is destroyed before deoptimization occurs.
697 assert(updates->count() > 0, "Updates holder not deleted");
698 // free deferred updates.
699 delete updates;
700 set_deferred_updates(nullptr);
701 }
702
703 // All Java related clean up happens in exit
704 ThreadSafepointState::destroy(this);
705 if (_thread_stat != nullptr) delete _thread_stat;
706
707 #if INCLUDE_JVMCI
708 if (JVMCICounterSize > 0) {
709 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
710 }
711 #endif // INCLUDE_JVMCI
712 }
713
714
715 // First JavaThread specific code executed by a new Java thread.
716 void JavaThread::pre_run() {
717 // empty - see comments in run()
718 }
719
720 // The main routine called by a new Java thread. This isn't overridden
721 // by subclasses, instead different subclasses define a different "entry_point"
722 // which defines the actual logic for that kind of thread.
723 void JavaThread::run() {
724 // initialize thread-local alloc buffer related fields
725 initialize_tlab();
726
727 _stack_overflow_state.create_stack_guard_pages();
728
729 cache_global_variables();
730
731 // Thread is now sufficiently initialized to be handled by the safepoint code as being
732 // in the VM. Change thread state from _thread_new to _thread_in_vm
733 assert(this->thread_state() == _thread_new, "wrong thread state");
734 set_thread_state(_thread_in_vm);
735
736 // Before a thread is on the threads list it is always safe, so after leaving the
737 // _thread_new we should emit a instruction barrier. The distance to modified code
738 // from here is probably far enough, but this is consistent and safe.
739 OrderAccess::cross_modify_fence();
740
741 assert(JavaThread::current() == this, "sanity check");
742 assert(!Thread::current()->owns_locks(), "sanity check");
743
744 JFR_ONLY(Jfr::on_thread_start(this);)
745
746 DTRACE_THREAD_PROBE(start, this);
747
748 // This operation might block. We call that after all safepoint checks for a new thread has
749 // been completed.
750 set_active_handles(JNIHandleBlock::allocate_block());
751
752 if (JvmtiExport::should_post_thread_life()) {
753 JvmtiExport::post_thread_start(this);
754
755 }
756
757 if (AlwaysPreTouchStacks) {
758 pretouch_stack();
759 }
760
761 // We call another function to do the rest so we are sure that the stack addresses used
762 // from there will be lower than the stack base just computed.
763 thread_main_inner();
764 }
765
766 void JavaThread::thread_main_inner() {
767 assert(JavaThread::current() == this, "sanity check");
768 assert(_threadObj.peek() != nullptr || is_aot_thread(), "just checking");
769
770 // Execute thread entry point unless this thread has a pending exception.
771 // Note: Due to JVMTI StopThread we can have pending exceptions already!
772 if (!this->has_pending_exception()) {
773 {
774 ResourceMark rm(this);
775 this->set_native_thread_name(this->name());
776 }
777 HandleMark hm(this);
778 this->entry_point()(this, this);
779 }
780
781 DTRACE_THREAD_PROBE(stop, this);
782
783 // Cleanup is handled in post_run()
784 }
785
786 // Shared teardown for all JavaThreads
787 void JavaThread::post_run() {
788 this->exit(false);
789 this->unregister_thread_stack_with_NMT();
790 // Defer deletion to here to ensure 'this' is still referenceable in call_run
791 // for any shared tear-down.
792 this->smr_delete();
793 }
794
795 static void ensure_join(JavaThread* thread) {
796 // We do not need to grab the Threads_lock, since we are operating on ourself.
797 Handle threadObj(thread, thread->threadObj());
798 assert(threadObj.not_null(), "java thread object must exist");
799 ObjectLocker lock(threadObj, thread);
800 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
801 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
802 // Clear the native thread instance - this makes isAlive return false and allows the join()
803 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model
804 // requirements.
805 assert(java_lang_Thread::thread(threadObj()) == thread, "must be alive");
806 java_lang_Thread::release_set_thread(threadObj(), nullptr);
807 lock.notify_all(thread);
808 // Ignore pending exception, since we are exiting anyway
809 thread->clear_pending_exception();
810 }
811
812 static bool is_daemon(oop threadObj) {
813 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj));
814 }
815
816 // For any new cleanup additions, please check to see if they need to be applied to
817 // cleanup_failed_attach_current_thread as well.
818 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
819 assert(this == JavaThread::current(), "thread consistency check");
820 assert(!is_exiting(), "should not be exiting or terminated already");
821
822 elapsedTimer _timer_exit_phase1;
823 elapsedTimer _timer_exit_phase2;
824 elapsedTimer _timer_exit_phase3;
825 elapsedTimer _timer_exit_phase4;
826
827 om_clear_monitor_cache();
828
829 if (log_is_enabled(Debug, os, thread, timer)) {
830 _timer_exit_phase1.start();
831 }
832
833 HandleMark hm(this);
834 Handle uncaught_exception(this, this->pending_exception());
835 this->clear_pending_exception();
836 Handle threadObj(this, this->threadObj());
837 assert(threadObj.not_null(), "Java thread object should be created");
838
839 if (!destroy_vm) {
840 if (uncaught_exception.not_null()) {
841 EXCEPTION_MARK;
842 // Call method Thread.dispatchUncaughtException().
843 Klass* thread_klass = vmClasses::Thread_klass();
844 JavaValue result(T_VOID);
845 JavaCalls::call_virtual(&result,
846 threadObj, thread_klass,
847 vmSymbols::dispatchUncaughtException_name(),
848 vmSymbols::throwable_void_signature(),
849 uncaught_exception,
850 THREAD);
851 if (HAS_PENDING_EXCEPTION) {
852 ResourceMark rm(this);
853 jio_fprintf(defaultStream::error_stream(),
854 "\nException: %s thrown from the UncaughtExceptionHandler"
855 " in thread \"%s\"\n",
856 pending_exception()->klass()->external_name(),
857 name());
858 CLEAR_PENDING_EXCEPTION;
859 }
860 }
861
862 if (!is_Compiler_thread()) {
863 // We have finished executing user-defined Java code and now have to do the
864 // implementation specific clean-up by calling Thread.exit(). We prevent any
865 // asynchronous exceptions from being delivered while in Thread.exit()
866 // to ensure the clean-up is not corrupted.
867 NoAsyncExceptionDeliveryMark _no_async(this);
868
869 EXCEPTION_MARK;
870 JavaValue result(T_VOID);
871 Klass* thread_klass = vmClasses::Thread_klass();
872 JavaCalls::call_virtual(&result,
873 threadObj, thread_klass,
874 vmSymbols::exit_method_name(),
875 vmSymbols::void_method_signature(),
876 THREAD);
877 CLEAR_PENDING_EXCEPTION;
878 }
879
880 // notify JVMTI
881 if (JvmtiExport::should_post_thread_life()) {
882 JvmtiExport::post_thread_end(this);
883 }
884 } else {
885 // before_exit() has already posted JVMTI THREAD_END events
886 }
887
888 // Cleanup any pending async exception now since we cannot access oops after
889 // BarrierSet::barrier_set()->on_thread_detach() has been executed.
890 if (has_async_exception_condition()) {
891 handshake_state()->clean_async_exception_operation();
892 }
893
894 // The careful dance between thread suspension and exit is handled here.
895 // Since we are in thread_in_vm state and suspension is done with handshakes,
896 // we can just put in the exiting state and it will be correctly handled.
897 // Also, no more async exceptions will be added to the queue after this point.
898 set_terminated(_thread_exiting);
899 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
900
901 if (log_is_enabled(Debug, os, thread, timer)) {
902 _timer_exit_phase1.stop();
903 _timer_exit_phase2.start();
904 }
905
906 // Capture daemon status before the thread is marked as terminated.
907 bool daemon = is_daemon(threadObj());
908
909 // Notify waiters on thread object. This has to be done after exit() is called
910 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
911 // group should have the destroyed bit set before waiters are notified).
912 ensure_join(this);
913 assert(!this->has_pending_exception(), "ensure_join should have cleared");
914
915 if (log_is_enabled(Debug, os, thread, timer)) {
916 _timer_exit_phase2.stop();
917 _timer_exit_phase3.start();
918 }
919 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
920 // held by this thread must be released. The spec does not distinguish
921 // between JNI-acquired and regular Java monitors. We can only see
922 // regular Java monitors here if monitor enter-exit matching is broken.
923 //
924 // ensure_join() ignores IllegalThreadStateExceptions, and so does
925 // ObjectSynchronizer::release_monitors_owned_by_thread().
926 if (exit_type == jni_detach) {
927 // Sanity check even though JNI DetachCurrentThread() would have
928 // returned JNI_ERR if there was a Java frame. JavaThread exit
929 // should be done executing Java code by the time we get here.
930 assert(!this->has_last_Java_frame(),
931 "should not have a Java frame when detaching or exiting");
932 ObjectSynchronizer::release_monitors_owned_by_thread(this);
933 assert(!this->has_pending_exception(), "release_monitors should have cleared");
934 }
935
936 // These things needs to be done while we are still a Java Thread. Make sure that thread
937 // is in a consistent state, in case GC happens
938 JFR_ONLY(Jfr::on_thread_exit(this);)
939
940 if (active_handles() != nullptr) {
941 JNIHandleBlock* block = active_handles();
942 set_active_handles(nullptr);
943 JNIHandleBlock::release_block(block);
944 }
945
946 if (free_handle_block() != nullptr) {
947 JNIHandleBlock* block = free_handle_block();
948 set_free_handle_block(nullptr);
949 JNIHandleBlock::release_block(block);
950 }
951
952 // These have to be removed while this is still a valid thread.
953 _stack_overflow_state.remove_stack_guard_pages();
954
955 if (UseTLAB) {
956 retire_tlab();
957 }
958
959 if (JvmtiEnv::environments_might_exist()) {
960 JvmtiExport::cleanup_thread(this);
961 }
962
963 // We need to cache the thread name for logging purposes below as once
964 // we have called on_thread_detach this thread must not access any oops.
965 char* thread_name = nullptr;
966 if (log_is_enabled(Debug, os, thread, timer) || (CountBytecodesPerThread && log_is_enabled(Info, init))) {
967 ResourceMark rm(this);
968 thread_name = os::strdup(name());
969 }
970
971 if (log_is_enabled(Info, os, thread)) {
972 ResourceMark rm(this);
973 log_info(os, thread)("JavaThread %s (name: \"%s\", tid: %zu).",
974 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
975 name(), os::current_thread_id());
976 }
977
978 if (log_is_enabled(Debug, os, thread, timer)) {
979 _timer_exit_phase3.stop();
980 _timer_exit_phase4.start();
981 }
982
983 #if INCLUDE_JVMCI
984 if (JVMCICounterSize > 0) {
985 if (jvmci_counters_include(this)) {
986 for (int i = 0; i < JVMCICounterSize; i++) {
987 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
988 }
989 }
990 }
991 #endif // INCLUDE_JVMCI
992
993 if (bc_counter_value() > 0) {
994 log_info(init)("Thread '%s': " JLONG_FORMAT " bytecodes executed (during clinit: " JLONG_FORMAT ")",
995 thread_name, bc_counter_value(), clinit_bc_counter_value());
996 }
997
998 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
999 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
1000 Threads::remove(this, daemon);
1001
1002 if (log_is_enabled(Debug, os, thread, timer)) {
1003 _timer_exit_phase4.stop();
1004 log_debug(os, thread, timer)("name='%s'"
1005 ", exit-phase1=" JLONG_FORMAT
1006 ", exit-phase2=" JLONG_FORMAT
1007 ", exit-phase3=" JLONG_FORMAT
1008 ", exit-phase4=" JLONG_FORMAT,
1009 thread_name,
1010 _timer_exit_phase1.milliseconds(),
1011 _timer_exit_phase2.milliseconds(),
1012 _timer_exit_phase3.milliseconds(),
1013 _timer_exit_phase4.milliseconds());
1014 os::free(thread_name);
1015 }
1016 }
1017
1018 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
1019 if (active_handles() != nullptr) {
1020 JNIHandleBlock* block = active_handles();
1021 set_active_handles(nullptr);
1022 JNIHandleBlock::release_block(block);
1023 }
1024
1025 if (free_handle_block() != nullptr) {
1026 JNIHandleBlock* block = free_handle_block();
1027 set_free_handle_block(nullptr);
1028 JNIHandleBlock::release_block(block);
1029 }
1030
1031 // These have to be removed while this is still a valid thread.
1032 _stack_overflow_state.remove_stack_guard_pages();
1033
1034 if (UseTLAB) {
1035 retire_tlab();
1036 }
1037
1038 Threads::remove(this, is_daemon);
1039 }
1040
1041 JavaThread* JavaThread::active() {
1042 Thread* thread = Thread::current();
1043 if (thread->is_Java_thread()) {
1044 return JavaThread::cast(thread);
1045 } else {
1046 assert(thread->is_VM_thread(), "this must be a vm thread");
1047 VM_Operation* op = ((VMThread*) thread)->vm_operation();
1048 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread());
1049 return ret;
1050 }
1051 }
1052
1053 oop JavaThread::exception_oop() const {
1054 return AtomicAccess::load(&_exception_oop);
1055 }
1056
1057 void JavaThread::set_exception_oop(oop o) {
1058 AtomicAccess::store(&_exception_oop, o);
1059 }
1060
1061 void JavaThread::handle_special_runtime_exit_condition() {
1062 if (is_obj_deopt_suspend()) {
1063 frame_anchor()->make_walkable();
1064 wait_for_object_deoptimization();
1065 }
1066 }
1067
1068
1069 // Asynchronous exceptions support
1070 //
1071 void JavaThread::handle_async_exception(oop java_throwable) {
1072 assert(java_throwable != nullptr, "should have an _async_exception to throw");
1073 assert(!is_at_poll_safepoint(), "should have never called this method");
1074
1075 if (has_last_Java_frame()) {
1076 frame f = last_frame();
1077 if (f.is_runtime_frame()) {
1078 // If the topmost frame is a runtime stub, then we are calling into
1079 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1080 // must deoptimize the caller before continuing, as the compiled exception
1081 // handler table may not be valid.
1082 RegisterMap reg_map(this,
1083 RegisterMap::UpdateMap::skip,
1084 RegisterMap::ProcessFrames::include,
1085 RegisterMap::WalkContinuation::skip);
1086 frame compiled_frame = f.sender(®_map);
1087 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1088 Deoptimization::deoptimize(this, compiled_frame);
1089 }
1090 }
1091 }
1092
1093 // We cannot call Exceptions::_throw(...) here because we cannot block
1094 set_pending_exception(java_throwable, __FILE__, __LINE__);
1095
1096 clear_scopedValueBindings();
1097
1098 LogTarget(Info, exceptions) lt;
1099 if (lt.is_enabled()) {
1100 ResourceMark rm;
1101 LogStream ls(lt);
1102 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1103 if (has_last_Java_frame()) {
1104 frame f = last_frame();
1105 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1106 }
1107 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1108 }
1109 }
1110
1111 void JavaThread::install_async_exception(AsyncExceptionHandshakeClosure* aehc) {
1112 // Do not throw asynchronous exceptions against the compiler thread
1113 // or if the thread is already exiting.
1114 if (!can_call_java() || is_exiting()) {
1115 delete aehc;
1116 return;
1117 }
1118
1119 oop exception = aehc->exception();
1120 Handshake::execute(aehc, this); // Install asynchronous handshake
1121
1122 ResourceMark rm;
1123 if (log_is_enabled(Info, exceptions)) {
1124 log_info(exceptions)("Pending Async. exception installed of type: %s",
1125 exception->klass()->external_name());
1126 }
1127 // for AbortVMOnException flag
1128 Exceptions::debug_check_abort(exception->klass()->external_name());
1129
1130 oop vt_oop = vthread();
1131 if (vt_oop == nullptr || !vt_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1132 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1133 this->interrupt();
1134 }
1135 }
1136
1137 class InstallAsyncExceptionHandshakeClosure : public HandshakeClosure {
1138 AsyncExceptionHandshakeClosure* _aehc;
1139 public:
1140 InstallAsyncExceptionHandshakeClosure(AsyncExceptionHandshakeClosure* aehc) :
1141 HandshakeClosure("InstallAsyncException"), _aehc(aehc) {}
1142 ~InstallAsyncExceptionHandshakeClosure() {
1143 // If InstallAsyncExceptionHandshakeClosure was never executed we need to clean up _aehc.
1144 delete _aehc;
1145 }
1146 void do_thread(Thread* thr) {
1147 JavaThread* target = JavaThread::cast(thr);
1148 target->install_async_exception(_aehc);
1149 _aehc = nullptr;
1150 }
1151 };
1152
1153 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1154 OopHandle e(Universe::vm_global(), java_throwable);
1155 InstallAsyncExceptionHandshakeClosure iaeh(new AsyncExceptionHandshakeClosure(e));
1156 Handshake::execute(&iaeh, target);
1157 }
1158
1159 #if INCLUDE_JVMTI
1160 void JavaThread::set_is_in_VTMS_transition(bool val) {
1161 assert(is_in_VTMS_transition() != val, "already %s transition", val ? "inside" : "outside");
1162 _is_in_VTMS_transition = val;
1163 }
1164
1165 #ifdef ASSERT
1166 void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1167 _is_VTMS_transition_disabler = val;
1168 }
1169 #endif
1170 #endif
1171
1172 // External suspension mechanism.
1173 //
1174 // Guarantees on return (for a valid target thread):
1175 // - Target thread will not execute any new bytecode.
1176 // - Target thread will not enter any new monitors.
1177 //
1178 bool JavaThread::java_suspend(bool register_vthread_SR) {
1179 #if INCLUDE_JVMTI
1180 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1181 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1182 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1183 #endif
1184
1185 guarantee(Thread::is_JavaThread_protected(/* target */ this),
1186 "target JavaThread is not protected in calling context.");
1187 return this->suspend_resume_manager()->suspend(register_vthread_SR);
1188 }
1189
1190 bool JavaThread::java_resume(bool register_vthread_SR) {
1191 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1192 "missing ThreadsListHandle in calling context.");
1193 return this->suspend_resume_manager()->resume(register_vthread_SR);
1194 }
1195
1196 // Wait for another thread to perform object reallocation and relocking on behalf of
1197 // this thread. The current thread is required to change to _thread_blocked in order
1198 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1199 // handshake safe, the other thread can complete the handshake used to synchronize
1200 // with this thread and then perform the reallocation and relocking.
1201 // See EscapeBarrier::sync_and_suspend_*()
1202
1203 void JavaThread::wait_for_object_deoptimization() {
1204 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1205 assert(this == Thread::current(), "invariant");
1206
1207 bool spin_wait = os::is_MP();
1208 do {
1209 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1210 // Wait for object deoptimization if requested.
1211 if (spin_wait) {
1212 // A single deoptimization is typically very short. Microbenchmarks
1213 // showed 5% better performance when spinning.
1214 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1215 SpinYield spin(spin_limit);
1216 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1217 spin.wait();
1218 }
1219 // Spin just once
1220 spin_wait = false;
1221 } else {
1222 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1223 if (is_obj_deopt_suspend()) {
1224 ml.wait();
1225 }
1226 }
1227 // A handshake for obj. deoptimization suspend could have been processed so
1228 // we must check after processing.
1229 } while (is_obj_deopt_suspend());
1230 }
1231
1232 #ifdef ASSERT
1233 // Verify the JavaThread has not yet been published in the Threads::list, and
1234 // hence doesn't need protection from concurrent access at this stage.
1235 void JavaThread::verify_not_published() {
1236 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1237 // since an unpublished JavaThread doesn't participate in the
1238 // Thread-SMR protocol for keeping a ThreadsList alive.
1239 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1240 }
1241 #endif
1242
1243 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1244 // pending, when _suspend_flags is non-zero or when we need to process a stack
1245 // watermark. Also check for pending async exceptions (except unsafe access error).
1246 // Note only the native==>Java barriers can call this function when thread state
1247 // is _thread_in_native_trans.
1248 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1249 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1250 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1251
1252 thread->set_thread_state(_thread_in_vm);
1253
1254 // Enable WXWrite: called directly from interpreter native wrapper.
1255 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1256
1257 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1258
1259 // After returning from native, it could be that the stack frames are not
1260 // yet safe to use. We catch such situations in the subsequent stack watermark
1261 // barrier, which will trap unsafe stack frames.
1262 StackWatermarkSet::before_unwind(thread);
1263 }
1264
1265 #ifndef PRODUCT
1266 // Deoptimization
1267 // Function for testing deoptimization
1268 void JavaThread::deoptimize() {
1269 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1270 bool deopt = false; // Dump stack only if a deopt actually happens.
1271 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1272 // Iterate over all frames in the thread and deoptimize
1273 for (; !fst.is_done(); fst.next()) {
1274 if (fst.current()->can_be_deoptimized()) {
1275
1276 if (only_at) {
1277 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1278 // consists of comma or carriage return separated numbers so
1279 // search for the current bci in that string.
1280 address pc = fst.current()->pc();
1281 nmethod* nm = fst.current()->cb()->as_nmethod();
1282 ScopeDesc* sd = nm->scope_desc_at(pc);
1283 char buffer[8];
1284 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1285 size_t len = strlen(buffer);
1286 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1287 while (found != nullptr) {
1288 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1289 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1290 // Check that the bci found is bracketed by terminators.
1291 break;
1292 }
1293 found = strstr(found + 1, buffer);
1294 }
1295 if (!found) {
1296 continue;
1297 }
1298 }
1299
1300 if (DebugDeoptimization && !deopt) {
1301 deopt = true; // One-time only print before deopt
1302 tty->print_cr("[BEFORE Deoptimization]");
1303 trace_frames();
1304 trace_stack();
1305 }
1306 Deoptimization::deoptimize(this, *fst.current());
1307 }
1308 }
1309
1310 if (DebugDeoptimization && deopt) {
1311 tty->print_cr("[AFTER Deoptimization]");
1312 trace_frames();
1313 }
1314 }
1315
1316
1317 // Make zombies
1318 void JavaThread::make_zombies() {
1319 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1320 if (fst.current()->can_be_deoptimized()) {
1321 // it is a Java nmethod
1322 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1323 assert(nm != nullptr, "did not find nmethod");
1324 nm->make_not_entrant(nmethod::InvalidationReason::ZOMBIE);
1325 }
1326 }
1327 }
1328 #endif // PRODUCT
1329
1330
1331 void JavaThread::deoptimize_marked_methods() {
1332 if (!has_last_Java_frame()) return;
1333 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1334 for (; !fst.is_done(); fst.next()) {
1335 if (fst.current()->should_be_deoptimized()) {
1336 Deoptimization::deoptimize(this, *fst.current());
1337 }
1338 }
1339 }
1340
1341 #ifdef ASSERT
1342 void JavaThread::verify_frame_info() {
1343 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1344 (has_last_Java_frame() && java_call_counter() > 0),
1345 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1346 has_last_Java_frame() ? "true" : "false", java_call_counter());
1347 }
1348 #endif
1349
1350 // Push on a new block of JNI handles.
1351 void JavaThread::push_jni_handle_block() {
1352 // Allocate a new block for JNI handles.
1353 // Inlined code from jni_PushLocalFrame()
1354 JNIHandleBlock* old_handles = active_handles();
1355 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1356 assert(old_handles != nullptr && new_handles != nullptr, "should not be null");
1357 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1358 set_active_handles(new_handles);
1359 }
1360
1361 // Pop off the current block of JNI handles.
1362 void JavaThread::pop_jni_handle_block() {
1363 // Release our JNI handle block
1364 JNIHandleBlock* old_handles = active_handles();
1365 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1366 assert(new_handles != nullptr, "should never set active handles to null");
1367 set_active_handles(new_handles);
1368 old_handles->set_pop_frame_link(nullptr);
1369 JNIHandleBlock::release_block(old_handles, this);
1370 }
1371
1372 void JavaThread::oops_do_no_frames(OopClosure* f, NMethodClosure* cf) {
1373 // Traverse the GCHandles
1374 Thread::oops_do_no_frames(f, cf);
1375
1376 if (active_handles() != nullptr) {
1377 active_handles()->oops_do(f);
1378 }
1379
1380 DEBUG_ONLY(verify_frame_info();)
1381
1382 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!");
1383 // If we have deferred set_locals there might be oops waiting to be
1384 // written
1385 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1386 if (list != nullptr) {
1387 for (int i = 0; i < list->length(); i++) {
1388 list->at(i)->oops_do(f);
1389 }
1390 }
1391
1392 // Traverse instance variables at the end since the GC may be moving things
1393 // around using this function
1394 f->do_oop((oop*) &_vm_result_oop);
1395 f->do_oop((oop*) &_exception_oop);
1396 #if INCLUDE_JVMCI
1397 f->do_oop((oop*) &_jvmci_reserved_oop0);
1398
1399 if (_live_nmethod != nullptr && cf != nullptr) {
1400 cf->do_nmethod(_live_nmethod);
1401 }
1402 #endif
1403
1404 if (jvmti_thread_state() != nullptr) {
1405 jvmti_thread_state()->oops_do(f, cf);
1406 }
1407
1408 // The continuation oops are really on the stack. But there is typically at most
1409 // one of those per thread, so we handle them here in the oops_do_no_frames part
1410 // so that we don't have to sprinkle as many stack watermark checks where these
1411 // oops are used. We just need to make sure the thread has started processing.
1412 ContinuationEntry* entry = _cont_entry;
1413 while (entry != nullptr) {
1414 f->do_oop((oop*)entry->cont_addr());
1415 f->do_oop((oop*)entry->chunk_addr());
1416 entry = entry->parent();
1417 }
1418
1419 // Due to fast locking
1420 lock_stack().oops_do(f);
1421 }
1422
1423 void JavaThread::oops_do_frames(OopClosure* f, NMethodClosure* cf) {
1424 if (!has_last_Java_frame()) {
1425 return;
1426 }
1427 // Finish any pending lazy GC activity for the frames
1428 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc);
1429 // Traverse the execution stack
1430 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1431 fst.current()->oops_do(f, cf, fst.register_map());
1432 }
1433 }
1434
1435 #ifdef ASSERT
1436 void JavaThread::verify_states_for_handshake() {
1437 // This checks that the thread has a correct frame state during a handshake.
1438 verify_frame_info();
1439 }
1440 #endif
1441
1442 void JavaThread::nmethods_do(NMethodClosure* cf) {
1443 DEBUG_ONLY(verify_frame_info();)
1444 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1445
1446 if (has_last_Java_frame()) {
1447 // Traverse the execution stack
1448 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1449 fst.current()->nmethod_do(cf);
1450 }
1451 }
1452
1453 if (jvmti_thread_state() != nullptr) {
1454 jvmti_thread_state()->nmethods_do(cf);
1455 }
1456
1457 #if INCLUDE_JVMCI
1458 if (_live_nmethod != nullptr) {
1459 cf->do_nmethod(_live_nmethod);
1460 }
1461 #endif
1462 }
1463
1464 void JavaThread::metadata_do(MetadataClosure* f) {
1465 if (has_last_Java_frame()) {
1466 // Traverse the execution stack to call f() on the methods in the stack
1467 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1468 fst.current()->metadata_do(f);
1469 }
1470 } else if (is_Compiler_thread()) {
1471 // need to walk ciMetadata in current compile tasks to keep alive.
1472 CompilerThread* ct = (CompilerThread*)this;
1473 if (ct->env() != nullptr) {
1474 ct->env()->metadata_do(f);
1475 }
1476 CompileTask* task = ct->task();
1477 if (task != nullptr) {
1478 task->metadata_do(f);
1479 }
1480 }
1481 }
1482
1483 // Printing
1484 static const char* _get_thread_state_name(JavaThreadState _thread_state) {
1485 switch (_thread_state) {
1486 case _thread_uninitialized: return "_thread_uninitialized";
1487 case _thread_new: return "_thread_new";
1488 case _thread_new_trans: return "_thread_new_trans";
1489 case _thread_in_native: return "_thread_in_native";
1490 case _thread_in_native_trans: return "_thread_in_native_trans";
1491 case _thread_in_vm: return "_thread_in_vm";
1492 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1493 case _thread_in_Java: return "_thread_in_Java";
1494 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1495 case _thread_blocked: return "_thread_blocked";
1496 case _thread_blocked_trans: return "_thread_blocked_trans";
1497 default: return "unknown thread state";
1498 }
1499 }
1500
1501 void JavaThread::print_thread_state_on(outputStream *st) const {
1502 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1503 }
1504
1505 // Called by Threads::print() for VM_PrintThreads operation
1506 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1507 st->print_raw("\"");
1508 st->print_raw(name());
1509 st->print_raw("\" ");
1510 oop thread_oop = threadObj();
1511 if (thread_oop != nullptr) {
1512 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1513 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1514 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1515 }
1516 Thread::print_on(st, print_extended_info);
1517 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1518 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1519 if (thread_oop != nullptr) {
1520 if (is_vthread_mounted()) {
1521 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(vthread()));
1522 } else {
1523 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1524 }
1525 }
1526 #ifndef PRODUCT
1527 _safepoint_state->print_on(st);
1528 #endif // PRODUCT
1529 if (is_Compiler_thread()) {
1530 CompileTask *task = ((CompilerThread*)this)->task();
1531 if (task != nullptr) {
1532 st->print(" Compiling: ");
1533 task->print(st, nullptr, true, false);
1534 } else {
1535 st->print(" No compile task");
1536 }
1537 st->cr();
1538 }
1539 }
1540
1541 void JavaThread::print() const { print_on(tty); }
1542
1543 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1544 st->print("%s", get_thread_name_string(buf, buflen));
1545 }
1546
1547 // Called by fatal error handler. The difference between this and
1548 // JavaThread::print() is that we can't grab lock or allocate memory.
1549 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1550 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1551 Thread* current = Thread::current_or_null_safe();
1552 assert(current != nullptr, "cannot be called by a detached thread");
1553 st->fill_to(60);
1554 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1555 // Only access threadObj() if current thread is not a JavaThread
1556 // or if it is a JavaThread that can safely access oops.
1557 oop thread_obj = threadObj();
1558 if (thread_obj != nullptr) {
1559 st->print(java_lang_Thread::is_daemon(thread_obj) ? " daemon" : " ");
1560 }
1561 }
1562 st->print(" [");
1563 st->print("%s", _get_thread_state_name(_thread_state));
1564 if (osthread()) {
1565 st->print(", id=%d", osthread()->thread_id());
1566 }
1567 // Use raw field members for stack base/size as this could be
1568 // called before a thread has run enough to initialize them.
1569 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ") (" PROPERFMT ")",
1570 p2i(_stack_base - _stack_size), p2i(_stack_base),
1571 PROPERFMTARGS(_stack_size));
1572 st->print("]");
1573
1574 ThreadsSMRSupport::print_info_on(this, st);
1575 return;
1576 }
1577
1578
1579 // Verification
1580
1581 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1582 // ignore if there is no stack
1583 if (!has_last_Java_frame()) return;
1584 // traverse the stack frames. Starts from top frame.
1585 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1586 frame* fr = fst.current();
1587 f(fr, fst.register_map());
1588 }
1589 }
1590
1591 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1592
1593 void JavaThread::verify() {
1594 // Verify oops in the thread.
1595 oops_do(&VerifyOopClosure::verify_oop, nullptr);
1596
1597 // Verify the stack frames.
1598 frames_do(frame_verify);
1599 }
1600
1601 // CR 6300358 (sub-CR 2137150)
1602 // Most callers of this method assume that it can't return null but a
1603 // thread may not have a name whilst it is in the process of attaching to
1604 // the VM - see CR 6412693, and there are places where a JavaThread can be
1605 // seen prior to having its threadObj set (e.g., JNI attaching threads and
1606 // if vm exit occurs during initialization). These cases can all be accounted
1607 // for such that this method never returns null.
1608 const char* JavaThread::name() const {
1609 if (Thread::is_JavaThread_protected(/* target */ this)) {
1610 // The target JavaThread is protected so get_thread_name_string() is safe:
1611 return get_thread_name_string();
1612 }
1613
1614 // The target JavaThread is not protected so we return the default:
1615 return Thread::name();
1616 }
1617
1618 // Like name() but doesn't include the protection check. This must only be
1619 // called when it is known to be safe, even though the protection check can't tell
1620 // that e.g. when this thread is the init_thread() - see instanceKlass.cpp.
1621 const char* JavaThread::name_raw() const {
1622 return get_thread_name_string();
1623 }
1624
1625 // Returns a non-null representation of this thread's name, or a suitable
1626 // descriptive string if there is no set name.
1627 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1628 const char* name_str;
1629 #ifdef ASSERT
1630 Thread* current = Thread::current_or_null_safe();
1631 assert(current != nullptr, "cannot be called by a detached thread");
1632 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1633 // Only access threadObj() if current thread is not a JavaThread
1634 // or if it is a JavaThread that can safely access oops.
1635 #endif
1636 oop thread_obj = threadObj();
1637 if (thread_obj != nullptr) {
1638 oop name = java_lang_Thread::name(thread_obj);
1639 if (name != nullptr) {
1640 if (buf == nullptr) {
1641 name_str = java_lang_String::as_utf8_string(name);
1642 } else {
1643 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1644 }
1645 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1646 name_str = "<no-name - thread is attaching>";
1647 } else {
1648 name_str = "<un-named>";
1649 }
1650 } else {
1651 name_str = Thread::name();
1652 }
1653 #ifdef ASSERT
1654 } else {
1655 // Current JavaThread has exited...
1656 if (current == this) {
1657 // ... and is asking about itself:
1658 name_str = "<no-name - current JavaThread has exited>";
1659 } else {
1660 // ... and it can't safely determine this JavaThread's name so
1661 // use the default thread name.
1662 name_str = Thread::name();
1663 }
1664 }
1665 #endif
1666 assert(name_str != nullptr, "unexpected null thread name");
1667 return name_str;
1668 }
1669
1670 // Helper to extract the name from the thread oop for logging.
1671 const char* JavaThread::name_for(oop thread_obj) {
1672 assert(thread_obj != nullptr, "precondition");
1673 oop name = java_lang_Thread::name(thread_obj);
1674 const char* name_str;
1675 if (name != nullptr) {
1676 name_str = java_lang_String::as_utf8_string(name);
1677 } else {
1678 name_str = "<un-named>";
1679 }
1680 return name_str;
1681 }
1682
1683 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1684
1685 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1686 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1687 // Link Java Thread object <-> C++ Thread
1688
1689 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1690 // and put it into a new Handle. The Handle "thread_oop" can then
1691 // be used to pass the C++ thread object to other methods.
1692
1693 // Set the Java level thread object (jthread) field of the
1694 // new thread (a JavaThread *) to C++ thread object using the
1695 // "thread_oop" handle.
1696
1697 // Set the thread field (a JavaThread *) of the
1698 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1699
1700 Handle thread_oop(Thread::current(),
1701 JNIHandles::resolve_non_null(jni_thread));
1702 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1703 "must be initialized");
1704 set_threadOopHandles(thread_oop());
1705 set_monitor_owner_id(java_lang_Thread::thread_id(thread_oop()));
1706
1707 if (prio == NoPriority) {
1708 prio = java_lang_Thread::priority(thread_oop());
1709 assert(prio != NoPriority, "A valid priority should be present");
1710 }
1711
1712 // Push the Java priority down to the native thread; needs Threads_lock
1713 Thread::set_priority(this, prio);
1714
1715 // Add the new thread to the Threads list and set it in motion.
1716 // We must have threads lock in order to call Threads::add.
1717 // It is crucial that we do not block before the thread is
1718 // added to the Threads list for if a GC happens, then the java_thread oop
1719 // will not be visited by GC.
1720 Threads::add(this);
1721 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
1722 // on a ThreadsList. We don't want to wait for the release when the
1723 // Theads_lock is dropped somewhere in the caller since the JavaThread*
1724 // is already visible to JVM/TI via the ThreadsList.
1725 java_lang_Thread::release_set_thread(thread_oop(), this);
1726 }
1727
1728 oop JavaThread::current_park_blocker() {
1729 // Support for JSR-166 locks
1730 oop thread_oop = threadObj();
1731 if (thread_oop != nullptr) {
1732 return java_lang_Thread::park_blocker(thread_oop);
1733 }
1734 return nullptr;
1735 }
1736
1737 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1738 // This is the external format, selecting the platform or vthread
1739 // as applicable, and allowing for a native-only stack.
1740 void JavaThread::print_jni_stack() {
1741 assert(this == JavaThread::current(), "Can't print stack of other threads");
1742 if (!has_last_Java_frame()) {
1743 ResourceMark rm(this);
1744 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
1745 if (buf == nullptr) {
1746 tty->print_cr("Unable to print native stack - out of memory");
1747 return;
1748 }
1749 NativeStackPrinter nsp(this);
1750 address lastpc = nullptr;
1751 nsp.print_stack(tty, buf, O_BUFLEN, lastpc,
1752 true /*print_source_info */, -1 /* max stack */ );
1753 } else {
1754 print_active_stack_on(tty);
1755 }
1756 }
1757
1758 void JavaThread::print_stack_on(outputStream* st) {
1759 if (!has_last_Java_frame()) return;
1760
1761 Thread* current_thread = Thread::current();
1762 ResourceMark rm(current_thread);
1763 HandleMark hm(current_thread);
1764
1765 RegisterMap reg_map(this,
1766 RegisterMap::UpdateMap::include,
1767 RegisterMap::ProcessFrames::include,
1768 RegisterMap::WalkContinuation::skip);
1769 vframe* start_vf = platform_thread_last_java_vframe(®_map);
1770 int count = 0;
1771 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1772 if (f->is_java_frame()) {
1773 javaVFrame* jvf = javaVFrame::cast(f);
1774 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1775
1776 // Print out lock information
1777 if (JavaMonitorsInStackTrace) {
1778 jvf->print_lock_info_on(st, false/*is_virtual*/, count);
1779 }
1780 } else {
1781 // Ignore non-Java frames
1782 }
1783
1784 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1785 count++;
1786 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1787 }
1788 }
1789
1790 void JavaThread::print_vthread_stack_on(outputStream* st) {
1791 assert(is_vthread_mounted(), "Caller should have checked this");
1792 assert(has_last_Java_frame(), "must be");
1793
1794 Thread* current_thread = Thread::current();
1795 ResourceMark rm(current_thread);
1796 HandleMark hm(current_thread);
1797
1798 RegisterMap reg_map(this,
1799 RegisterMap::UpdateMap::include,
1800 RegisterMap::ProcessFrames::include,
1801 RegisterMap::WalkContinuation::include);
1802 ContinuationEntry* cont_entry = last_continuation();
1803 vframe* start_vf = last_java_vframe(®_map);
1804 int count = 0;
1805 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1806 // Watch for end of vthread stack
1807 if (Continuation::is_continuation_enterSpecial(f->fr())) {
1808 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), "");
1809 if (cont_entry->is_virtual_thread()) {
1810 break;
1811 }
1812 cont_entry = cont_entry->parent();
1813 }
1814 if (f->is_java_frame()) {
1815 javaVFrame* jvf = javaVFrame::cast(f);
1816 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1817
1818 // Print out lock information
1819 if (JavaMonitorsInStackTrace) {
1820 jvf->print_lock_info_on(st, true/*is_virtual*/, count);
1821 }
1822 } else {
1823 // Ignore non-Java frames
1824 }
1825
1826 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1827 count++;
1828 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1829 }
1830 }
1831
1832 void JavaThread::print_active_stack_on(outputStream* st) {
1833 if (is_vthread_mounted()) {
1834 print_vthread_stack_on(st);
1835 } else {
1836 print_stack_on(st);
1837 }
1838 }
1839
1840 #if INCLUDE_JVMTI
1841 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1842 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1843 set_jvmti_vthread(thread_oop);
1844
1845 // unbind current JvmtiThreadState from JavaThread
1846 JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1847
1848 // bind new JvmtiThreadState to JavaThread
1849 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1850
1851 // enable interp_only_mode for virtual or carrier thread if it has pending bit
1852 JvmtiThreadState::process_pending_interp_only(this);
1853
1854 return jvmti_thread_state();
1855 }
1856 #endif
1857
1858 // JVMTI PopFrame support
1859 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1860 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments");
1861 if (in_bytes(size_in_bytes) != 0) {
1862 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1863 _popframe_preserved_args_size = in_bytes(size_in_bytes);
1864 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1865 }
1866 }
1867
1868 void* JavaThread::popframe_preserved_args() {
1869 return _popframe_preserved_args;
1870 }
1871
1872 ByteSize JavaThread::popframe_preserved_args_size() {
1873 return in_ByteSize(_popframe_preserved_args_size);
1874 }
1875
1876 WordSize JavaThread::popframe_preserved_args_size_in_words() {
1877 int sz = in_bytes(popframe_preserved_args_size());
1878 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1879 return in_WordSize(sz / wordSize);
1880 }
1881
1882 void JavaThread::popframe_free_preserved_args() {
1883 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice");
1884 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1885 _popframe_preserved_args = nullptr;
1886 _popframe_preserved_args_size = 0;
1887 }
1888
1889 #ifndef PRODUCT
1890
1891 void JavaThread::trace_frames() {
1892 tty->print_cr("[Describe stack]");
1893 int frame_no = 1;
1894 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1895 tty->print(" %d. ", frame_no++);
1896 fst.current()->print_value_on(tty);
1897 tty->cr();
1898 }
1899 }
1900
1901 class PrintAndVerifyOopClosure: public OopClosure {
1902 protected:
1903 template <class T> inline void do_oop_work(T* p) {
1904 oop obj = RawAccess<>::oop_load(p);
1905 if (obj == nullptr) return;
1906 tty->print(INTPTR_FORMAT ": ", p2i(p));
1907 if (oopDesc::is_oop_or_null(obj)) {
1908 if (obj->is_objArray()) {
1909 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1910 } else {
1911 obj->print();
1912 }
1913 } else {
1914 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1915 }
1916 tty->cr();
1917 }
1918 public:
1919 virtual void do_oop(oop* p) { do_oop_work(p); }
1920 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1921 };
1922
1923 #ifdef ASSERT
1924 // Print or validate the layout of stack frames
1925 void JavaThread::print_frame_layout(int depth, bool validate_only) {
1926 ResourceMark rm;
1927 PreserveExceptionMark pm(this);
1928 FrameValues values;
1929 int frame_no = 0;
1930 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1931 fst.current()->describe(values, ++frame_no, fst.register_map());
1932 if (depth == frame_no) break;
1933 }
1934 Continuation::describe(values);
1935 if (validate_only) {
1936 values.validate();
1937 } else {
1938 tty->print_cr("[Describe stack layout]");
1939 values.print(this);
1940 }
1941 }
1942 #endif
1943
1944 void JavaThread::trace_stack_from(vframe* start_vf) {
1945 ResourceMark rm;
1946 int vframe_no = 1;
1947 for (vframe* f = start_vf; f; f = f->sender()) {
1948 if (f->is_java_frame()) {
1949 javaVFrame::cast(f)->print_activation(vframe_no++);
1950 } else {
1951 f->print();
1952 }
1953 if (vframe_no > StackPrintLimit) {
1954 tty->print_cr("...<more frames>...");
1955 return;
1956 }
1957 }
1958 }
1959
1960
1961 void JavaThread::trace_stack() {
1962 if (!has_last_Java_frame()) return;
1963 Thread* current_thread = Thread::current();
1964 ResourceMark rm(current_thread);
1965 HandleMark hm(current_thread);
1966 RegisterMap reg_map(this,
1967 RegisterMap::UpdateMap::include,
1968 RegisterMap::ProcessFrames::include,
1969 RegisterMap::WalkContinuation::skip);
1970 trace_stack_from(last_java_vframe(®_map));
1971 }
1972
1973
1974 #endif // PRODUCT
1975
1976 frame JavaThread::vthread_last_frame() {
1977 assert (is_vthread_mounted(), "Virtual thread not mounted");
1978 return last_frame();
1979 }
1980
1981 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
1982 const ContinuationEntry* entry = vthread_continuation();
1983 guarantee (entry != nullptr, "Not a carrier thread");
1984 frame f = entry->to_frame();
1985 if (reg_map->process_frames()) {
1986 entry->flush_stack_processing(this);
1987 }
1988 entry->update_register_map(reg_map);
1989 return f.sender(reg_map);
1990 }
1991
1992 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
1993 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
1994 }
1995
1996 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
1997 assert(reg_map != nullptr, "a map must be given");
1998 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
1999 if (vf->is_java_frame()) return javaVFrame::cast(vf);
2000 }
2001 return nullptr;
2002 }
2003
2004 Klass* JavaThread::security_get_caller_class(int depth) {
2005 ResetNoHandleMark rnhm;
2006 HandleMark hm(Thread::current());
2007
2008 vframeStream vfst(this);
2009 vfst.security_get_caller_frame(depth);
2010 if (!vfst.at_end()) {
2011 return vfst.method()->method_holder();
2012 }
2013 return nullptr;
2014 }
2015
2016 // Internal convenience function for millisecond resolution sleeps.
2017 bool JavaThread::sleep(jlong millis) {
2018 jlong nanos;
2019 if (millis > max_jlong / NANOUNITS_PER_MILLIUNIT) {
2020 // Conversion to nanos would overflow, saturate at max
2021 nanos = max_jlong;
2022 } else {
2023 nanos = millis * NANOUNITS_PER_MILLIUNIT;
2024 }
2025 return sleep_nanos(nanos);
2026 }
2027
2028 // java.lang.Thread.sleep support
2029 // Returns true if sleep time elapsed as expected, and false
2030 // if the thread was interrupted or async exception was installed.
2031 bool JavaThread::sleep_nanos(jlong nanos) {
2032 assert(this == Thread::current(), "thread consistency check");
2033 assert(nanos >= 0, "nanos are in range");
2034
2035 ParkEvent * const slp = this->_SleepEvent;
2036 // Because there can be races with thread interruption sending an unpark()
2037 // to the event, we explicitly reset it here to avoid an immediate return.
2038 // The actual interrupt state will be checked before we park().
2039 slp->reset();
2040 // Thread interruption establishes a happens-before ordering in the
2041 // Java Memory Model, so we need to ensure we synchronize with the
2042 // interrupt state.
2043 OrderAccess::fence();
2044
2045 jlong prevtime = os::javaTimeNanos();
2046
2047 jlong nanos_remaining = nanos;
2048
2049 for (;;) {
2050 if (has_async_exception_condition()) {
2051 return false;
2052 }
2053 // interruption has precedence over timing out
2054 if (this->is_interrupted(true)) {
2055 return false;
2056 }
2057
2058 if (nanos_remaining <= 0) {
2059 return true;
2060 }
2061
2062 {
2063 ThreadBlockInVM tbivm(this);
2064 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2065 slp->park_nanos(nanos_remaining);
2066 }
2067
2068 // Update elapsed time tracking
2069 jlong newtime = os::javaTimeNanos();
2070 if (newtime - prevtime < 0) {
2071 // time moving backwards, should only happen if no monotonic clock
2072 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2073 assert(false,
2074 "unexpected time moving backwards detected in JavaThread::sleep()");
2075 } else {
2076 nanos_remaining -= (newtime - prevtime);
2077 }
2078 prevtime = newtime;
2079 }
2080 }
2081
2082 // Last thread running calls java.lang.Shutdown.shutdown()
2083 void JavaThread::invoke_shutdown_hooks() {
2084 HandleMark hm(this);
2085
2086 // We could get here with a pending exception, if so clear it now.
2087 if (this->has_pending_exception()) {
2088 this->clear_pending_exception();
2089 }
2090
2091 EXCEPTION_MARK;
2092 Klass* shutdown_klass =
2093 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
2094 THREAD);
2095 if (shutdown_klass != nullptr) {
2096 // SystemDictionary::resolve_or_null will return null if there was
2097 // an exception. If we cannot load the Shutdown class, just don't
2098 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
2099 // won't be run. Note that if a shutdown hook was registered,
2100 // the Shutdown class would have already been loaded
2101 // (Runtime.addShutdownHook will load it).
2102 JavaValue result(T_VOID);
2103 JavaCalls::call_static(&result,
2104 shutdown_klass,
2105 vmSymbols::shutdown_name(),
2106 vmSymbols::void_method_signature(),
2107 THREAD);
2108 }
2109 CLEAR_PENDING_EXCEPTION;
2110 }
2111
2112 #ifndef PRODUCT
2113 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
2114 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
2115 }
2116 #endif
2117
2118 // Helper function to create the java.lang.Thread object for a
2119 // VM-internal thread. The thread will have the given name, and be
2120 // a member of the "system" ThreadGroup.
2121 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) {
2122 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2123
2124 // Initialize thread_oop to put it into the system threadGroup.
2125 // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2126 Handle thread_group(THREAD, Universe::system_thread_group());
2127 Handle thread_oop =
2128 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2129 vmSymbols::threadgroup_string_void_signature(),
2130 thread_group,
2131 string,
2132 CHECK_NH);
2133
2134 return thread_oop;
2135 }
2136
2137 // Starts the target JavaThread as a daemon of the given priority, and
2138 // bound to the given java.lang.Thread instance.
2139 // The Threads_lock is held for the duration.
2140 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2141 Handle thread_oop, ThreadPriority prio) {
2142
2143 assert(target->osthread() != nullptr, "target thread is not properly initialized");
2144
2145 MutexLocker mu(current, Threads_lock);
2146
2147 // Initialize the fields of the thread_oop first.
2148 if (prio != NoPriority) {
2149 java_lang_Thread::set_priority(thread_oop(), prio);
2150 // Note: we don't call os::set_priority here. Possibly we should,
2151 // else all threads should call it themselves when they first run.
2152 }
2153
2154 java_lang_Thread::set_daemon(thread_oop());
2155
2156 // Now bind the thread_oop to the target JavaThread.
2157 target->set_threadOopHandles(thread_oop());
2158 target->set_monitor_owner_id(java_lang_Thread::thread_id(thread_oop()));
2159
2160 Threads::add(target); // target is now visible for safepoint/handshake
2161 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
2162 // on a ThreadsList. We don't want to wait for the release when the
2163 // Theads_lock is dropped when the 'mu' destructor is run since the
2164 // JavaThread* is already visible to JVM/TI via the ThreadsList.
2165
2166 assert(java_lang_Thread::thread(thread_oop()) == nullptr, "must not be alive");
2167 java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now
2168 Thread::start(target);
2169 }
2170
2171 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2172 // At this point it may be possible that no osthread was created for the
2173 // JavaThread due to lack of resources. However, since this must work
2174 // for critical system threads just check and abort if this fails.
2175 if (thread->osthread() == nullptr) {
2176 // This isn't really an OOM condition, but historically this is what
2177 // we report.
2178 vm_exit_during_initialization("java.lang.OutOfMemoryError",
2179 os::native_thread_creation_failed_msg());
2180 }
2181 }
2182
2183 void JavaThread::pretouch_stack() {
2184 // Given an established java thread stack with usable area followed by
2185 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging
2186 // from the current frame down to the start of the shadow zone.
2187 const address end = _stack_overflow_state.shadow_zone_safe_limit();
2188 if (is_in_full_stack(end)) {
2189 char* p1 = (char*) alloca(1);
2190 address here = (address) &p1;
2191 if (is_in_full_stack(here) && here > end) {
2192 size_t to_alloc = here - end;
2193 char* p2 = (char*) alloca(to_alloc);
2194 log_trace(os, thread)("Pretouching thread stack for %zu: " RANGEFMT ".",
2195 (uintx) osthread()->thread_id(), RANGEFMTARGS(p2, to_alloc));
2196 os::pretouch_memory(p2, p2 + to_alloc,
2197 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096));
2198 }
2199 }
2200 }
2201
2202 // Deferred OopHandle release support.
2203
2204 class OopHandleList : public CHeapObj<mtInternal> {
2205 static const int _count = 4;
2206 OopHandle _handles[_count];
2207 OopHandleList* _next;
2208 int _index;
2209 public:
2210 OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2211 void add(OopHandle h) {
2212 assert(_index < _count, "too many additions");
2213 _handles[_index++] = h;
2214 }
2215 ~OopHandleList() {
2216 assert(_index == _count, "usage error");
2217 for (int i = 0; i < _index; i++) {
2218 _handles[i].release(JavaThread::thread_oop_storage());
2219 }
2220 }
2221 OopHandleList* next() const { return _next; }
2222 };
2223
2224 OopHandleList* JavaThread::_oop_handle_list = nullptr;
2225
2226 // Called by the ServiceThread to do the work of releasing
2227 // the OopHandles.
2228 void JavaThread::release_oop_handles() {
2229 OopHandleList* list;
2230 {
2231 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2232 list = _oop_handle_list;
2233 _oop_handle_list = nullptr;
2234 }
2235 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2236
2237 while (list != nullptr) {
2238 OopHandleList* l = list;
2239 list = l->next();
2240 delete l;
2241 }
2242 }
2243
2244 // Add our OopHandles for later release.
2245 void JavaThread::add_oop_handles_for_release() {
2246 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2247 OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2248 new_head->add(_threadObj);
2249 new_head->add(_vthread);
2250 new_head->add(_jvmti_vthread);
2251 new_head->add(_scopedValueCache);
2252 _oop_handle_list = new_head;
2253 Service_lock->notify_all();
2254 }
2255
2256 #if INCLUDE_JFR
2257 void JavaThread::set_last_freeze_fail_result(freeze_result result) {
2258 assert(result != freeze_ok, "sanity check");
2259 _last_freeze_fail_result = result;
2260 _last_freeze_fail_time = Ticks::now();
2261 }
2262
2263 // Post jdk.VirtualThreadPinned event
2264 void JavaThread::post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) {
2265 assert(result != freeze_ok, "sanity check");
2266 if (event->should_commit()) {
2267 char reason[256];
2268 if (class_to_be_initialized() != nullptr) {
2269 ResourceMark rm(this);
2270 jio_snprintf(reason, sizeof reason, "Waited for initialization of %s by another thread",
2271 class_to_be_initialized()->external_name());
2272 event->set_pinnedReason(reason);
2273 } else if (class_being_initialized() != nullptr) {
2274 ResourceMark rm(this);
2275 jio_snprintf(reason, sizeof(reason), "VM call to %s.<clinit> on stack",
2276 class_being_initialized()->external_name());
2277 event->set_pinnedReason(reason);
2278 } else if (result == freeze_pinned_native) {
2279 event->set_pinnedReason("Native or VM frame on stack");
2280 } else {
2281 jio_snprintf(reason, sizeof(reason), "Freeze or preempt failed (%d)", result);
2282 event->set_pinnedReason(reason);
2283 }
2284 event->set_blockingOperation(op);
2285 event->set_carrierThread(JFR_JVM_THREAD_ID(this));
2286 event->commit();
2287 }
2288 }
2289 #endif