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