1 /*
2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "cds/dynamicArchive.hpp"
28 #include "ci/ciEnv.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/javaThreadStatus.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "classfile/vmClasses.hpp"
33 #include "classfile/vmSymbols.hpp"
34 #include "code/codeCache.hpp"
35 #include "code/scopeDesc.hpp"
36 #include "compiler/compileTask.hpp"
37 #include "compiler/compilerThread.hpp"
38 #include "gc/shared/oopStorage.hpp"
39 #include "gc/shared/oopStorageSet.hpp"
40 #include "gc/shared/tlab_globals.hpp"
41 #include "jfr/jfrEvents.hpp"
42 #include "jvm.h"
43 #include "jvmtifiles/jvmtiEnv.hpp"
44 #include "logging/log.hpp"
45 #include "logging/logAsyncWriter.hpp"
46 #include "logging/logStream.hpp"
47 #include "memory/allocation.inline.hpp"
48 #include "memory/iterator.hpp"
49 #include "memory/universe.hpp"
50 #include "oops/access.inline.hpp"
51 #include "oops/instanceKlass.hpp"
52 #include "oops/klass.inline.hpp"
53 #include "oops/oop.inline.hpp"
54 #include "oops/oopHandle.inline.hpp"
55 #include "oops/verifyOopClosure.hpp"
56 #include "prims/jvm_misc.hpp"
57 #include "prims/jvmtiDeferredUpdates.hpp"
58 #include "prims/jvmtiExport.hpp"
59 #include "prims/jvmtiThreadState.inline.hpp"
60 #include "runtime/atomic.hpp"
61 #include "runtime/continuation.hpp"
62 #include "runtime/continuationEntry.inline.hpp"
63 #include "runtime/continuationHelper.inline.hpp"
64 #include "runtime/deoptimization.hpp"
65 #include "runtime/frame.inline.hpp"
66 #include "runtime/handles.inline.hpp"
67 #include "runtime/handshake.hpp"
68 #include "runtime/interfaceSupport.inline.hpp"
69 #include "runtime/java.hpp"
70 #include "runtime/javaCalls.hpp"
71 #include "runtime/javaThread.inline.hpp"
72 #include "runtime/jniHandles.inline.hpp"
73 #include "runtime/lockStack.inline.hpp"
74 #include "runtime/mutexLocker.hpp"
75 #include "runtime/orderAccess.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/threadCritical.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/vframeArray.hpp"
92 #include "runtime/vframe_hp.hpp"
93 #include "runtime/vmThread.hpp"
94 #include "runtime/vmOperations.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/preserveException.hpp"
102 #include "utilities/spinYield.hpp"
103 #include "utilities/vmError.hpp"
104 #if INCLUDE_JVMCI
105 #include "jvmci/jvmci.hpp"
106 #include "jvmci/jvmciEnv.hpp"
107 #endif
108 #if INCLUDE_JFR
109 #include "jfr/jfr.hpp"
110 #endif
111
112 // Set by os layer.
113 size_t JavaThread::_stack_size_at_create = 0;
114
115 #ifdef DTRACE_ENABLED
116
117 // Only bother with this argument setup if dtrace is available
118
119 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
120 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
121
122 #define DTRACE_THREAD_PROBE(probe, javathread) \
123 { \
124 ResourceMark rm(this); \
125 int len = 0; \
126 const char* name = (javathread)->name(); \
127 len = strlen(name); \
128 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
129 (char *) name, len, \
130 java_lang_Thread::thread_id((javathread)->threadObj()), \
131 (uintptr_t) (javathread)->osthread()->thread_id(), \
132 java_lang_Thread::is_daemon((javathread)->threadObj())); \
133 }
134
135 #else // ndef DTRACE_ENABLED
136
137 #define DTRACE_THREAD_PROBE(probe, javathread)
138
139 #endif // ndef DTRACE_ENABLED
140
141 void JavaThread::smr_delete() {
142 if (_on_thread_list) {
143 ThreadsSMRSupport::smr_delete(this);
144 } else {
145 delete this;
146 }
147 }
148
149 // Initialized by VMThread at vm_global_init
150 OopStorage* JavaThread::_thread_oop_storage = nullptr;
151
152 OopStorage* JavaThread::thread_oop_storage() {
153 assert(_thread_oop_storage != nullptr, "not yet initialized");
154 return _thread_oop_storage;
155 }
156
157 void JavaThread::set_threadOopHandles(oop p) {
158 assert(_thread_oop_storage != nullptr, "not yet initialized");
159 _threadObj = OopHandle(_thread_oop_storage, p);
160 _vthread = OopHandle(_thread_oop_storage, p);
161 _jvmti_vthread = OopHandle(_thread_oop_storage, p->is_a(vmClasses::BoundVirtualThread_klass()) ? p : nullptr);
162 _scopedValueCache = OopHandle(_thread_oop_storage, nullptr);
163 }
164
165 oop JavaThread::threadObj() const {
166 // Ideally we would verify the current thread is oop_safe when this is called, but as we can
167 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That
168 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS.
169 // Instead callers must verify oop safe access.
170 return _threadObj.resolve();
171 }
172
173 oop JavaThread::vthread() const {
174 return _vthread.resolve();
175 }
176
177 void JavaThread::set_vthread(oop p) {
178 assert(_thread_oop_storage != nullptr, "not yet initialized");
179 _vthread.replace(p);
180 }
181
182 oop JavaThread::jvmti_vthread() const {
183 return _jvmti_vthread.resolve();
184 }
185
186 void JavaThread::set_jvmti_vthread(oop p) {
187 assert(_thread_oop_storage != nullptr, "not yet initialized");
188 _jvmti_vthread.replace(p);
189 }
190
191 oop JavaThread::scopedValueCache() const {
192 return _scopedValueCache.resolve();
193 }
194
195 void JavaThread::set_scopedValueCache(oop p) {
196 if (_scopedValueCache.ptr_raw() != nullptr) { // i.e. if the OopHandle has been allocated
197 _scopedValueCache.replace(p);
198 } else {
199 assert(p == nullptr, "not yet initialized");
200 }
201 }
202
203 void JavaThread::clear_scopedValueBindings() {
204 set_scopedValueCache(nullptr);
205 oop vthread_oop = vthread();
206 // vthread may be null here if we get a VM error during startup,
207 // before the java.lang.Thread instance has been created.
208 if (vthread_oop != nullptr) {
209 java_lang_Thread::clear_scopedValueBindings(vthread_oop);
210 }
211 }
212
213 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
214 bool daemon, TRAPS) {
215 assert(thread_group.not_null(), "thread group should be specified");
216 assert(threadObj() == nullptr, "should only create Java thread object once");
217
218 InstanceKlass* ik = vmClasses::Thread_klass();
219 assert(ik->is_initialized(), "must be");
220 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
221
222 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
223 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
224 // constructor calls Thread.current(), which must be set here.
225 java_lang_Thread::set_thread(thread_oop(), this);
226 set_threadOopHandles(thread_oop());
227
228 JavaValue result(T_VOID);
229 if (thread_name != nullptr) {
230 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
231 // Thread gets assigned specified name and null target
232 JavaCalls::call_special(&result,
233 thread_oop,
234 ik,
235 vmSymbols::object_initializer_name(),
236 vmSymbols::threadgroup_string_void_signature(),
237 thread_group,
238 name,
239 THREAD);
240 } else {
241 // Thread gets assigned name "Thread-nnn" and null target
242 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
243 JavaCalls::call_special(&result,
244 thread_oop,
245 ik,
246 vmSymbols::object_initializer_name(),
247 vmSymbols::threadgroup_runnable_void_signature(),
248 thread_group,
249 Handle(),
250 THREAD);
251 }
252 os::set_priority(this, NormPriority);
253
254 if (daemon) {
255 java_lang_Thread::set_daemon(thread_oop());
256 }
257 }
258
259 // ======= JavaThread ========
260
261 #if INCLUDE_JVMCI
262
263 jlong* JavaThread::_jvmci_old_thread_counters;
264
265 bool jvmci_counters_include(JavaThread* thread) {
266 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
267 }
268
269 void JavaThread::collect_counters(jlong* array, int length) {
270 assert(length == JVMCICounterSize, "wrong value");
271 for (int i = 0; i < length; i++) {
272 array[i] = _jvmci_old_thread_counters[i];
273 }
274 for (JavaThread* tp : ThreadsListHandle()) {
275 if (jvmci_counters_include(tp)) {
276 for (int i = 0; i < length; i++) {
277 array[i] += tp->_jvmci_counters[i];
278 }
279 }
280 }
281 }
282
283 // Attempt to enlarge the array for per thread counters.
284 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
285 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
286 if (new_counters == nullptr) {
287 return nullptr;
288 }
289 if (old_counters == nullptr) {
290 old_counters = new_counters;
291 memset(old_counters, 0, sizeof(jlong) * new_size);
292 } else {
293 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
294 new_counters[i] = old_counters[i];
295 }
296 if (new_size > current_size) {
297 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
298 }
299 FREE_C_HEAP_ARRAY(jlong, old_counters);
300 }
301 return new_counters;
302 }
303
304 // Attempt to enlarge the array for per thread counters.
305 bool JavaThread::resize_counters(int current_size, int new_size) {
306 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
307 if (new_counters == nullptr) {
308 return false;
309 } else {
310 _jvmci_counters = new_counters;
311 return true;
312 }
313 }
314
315 class VM_JVMCIResizeCounters : public VM_Operation {
316 private:
317 int _new_size;
318 bool _failed;
319
320 public:
321 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
322 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
323 bool allow_nested_vm_operations() const { return true; }
324 void doit() {
325 // Resize the old thread counters array
326 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
327 if (new_counters == nullptr) {
328 _failed = true;
329 return;
330 } else {
331 JavaThread::_jvmci_old_thread_counters = new_counters;
332 }
333
334 // Now resize each threads array
335 for (JavaThread* tp : ThreadsListHandle()) {
336 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
337 _failed = true;
338 break;
339 }
340 }
341 if (!_failed) {
342 JVMCICounterSize = _new_size;
343 }
344 }
345
346 bool failed() { return _failed; }
347 };
348
349 bool JavaThread::resize_all_jvmci_counters(int new_size) {
350 VM_JVMCIResizeCounters op(new_size);
351 VMThread::execute(&op);
352 return !op.failed();
353 }
354
355 #endif // INCLUDE_JVMCI
356
357 #ifdef ASSERT
358 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
359 void JavaThread::check_possible_safepoint() {
360 if (_no_safepoint_count > 0) {
361 print_owned_locks();
362 assert(false, "Possible safepoint reached by thread that does not allow it");
363 }
364 #ifdef CHECK_UNHANDLED_OOPS
365 // Clear unhandled oops in JavaThreads so we get a crash right away.
366 clear_unhandled_oops();
367 #endif // CHECK_UNHANDLED_OOPS
368
369 // Macos/aarch64 should be in the right state for safepoint (e.g.
370 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely
371 // happens in practice, making such issues hard to find and reproduce.
372 #if defined(__APPLE__) && defined(AARCH64)
373 if (AssertWXAtThreadSync) {
374 assert_wx_state(WXWrite);
375 }
376 #endif
377 }
378
379 void JavaThread::check_for_valid_safepoint_state() {
380 // Check NoSafepointVerifier, which is implied by locks taken that can be
381 // shared with the VM thread. This makes sure that no locks with allow_vm_block
382 // are held.
383 check_possible_safepoint();
384
385 if (thread_state() != _thread_in_vm) {
386 fatal("LEAF method calling lock?");
387 }
388
389 if (GCALotAtAllSafepoints) {
390 // We could enter a safepoint here and thus have a gc
391 InterfaceSupport::check_gc_alot();
392 }
393 }
394 #endif // ASSERT
395
396 // A JavaThread is a normal Java thread
397
398 JavaThread::JavaThread() :
399 // Initialize fields
400
401 _on_thread_list(false),
402 DEBUG_ONLY(_java_call_counter(0) COMMA)
403 _entry_point(nullptr),
404 _deopt_mark(nullptr),
405 _deopt_nmethod(nullptr),
406 _vframe_array_head(nullptr),
407 _vframe_array_last(nullptr),
408 _jvmti_deferred_updates(nullptr),
409 _callee_target(nullptr),
410 _vm_result(nullptr),
411 _vm_result_2(nullptr),
412
413 _current_pending_monitor(nullptr),
414 _current_pending_monitor_is_from_java(true),
415 _current_waiting_monitor(nullptr),
416 _active_handles(nullptr),
417 _free_handle_block(nullptr),
418 _Stalled(0),
419
420 _monitor_chunks(nullptr),
421
422 _suspend_flags(0),
423
424 _thread_state(_thread_new),
425 _saved_exception_pc(nullptr),
426 #ifdef ASSERT
427 _no_safepoint_count(0),
428 _visited_for_critical_count(false),
429 #endif
430
431 _terminated(_not_terminated),
432 _in_deopt_handler(0),
433 _doing_unsafe_access(false),
434 _do_not_unlock_if_synchronized(false),
435 #if INCLUDE_JVMTI
436 _carrier_thread_suspended(false),
437 _is_in_VTMS_transition(false),
438 _is_in_tmp_VTMS_transition(false),
439 #ifdef ASSERT
440 _is_VTMS_transition_disabler(false),
441 #endif
442 #endif
443 _jni_attach_state(_not_attaching_via_jni),
444 #if INCLUDE_JVMCI
445 _pending_deoptimization(-1),
446 _pending_monitorenter(false),
447 _pending_transfer_to_interpreter(false),
448 _in_retryable_allocation(false),
449 _pending_failed_speculation(0),
450 _jvmci{nullptr},
451 _libjvmci_runtime(nullptr),
452 _jvmci_counters(nullptr),
453 _jvmci_reserved0(0),
454 _jvmci_reserved1(0),
455 _jvmci_reserved_oop0(nullptr),
456 #endif // INCLUDE_JVMCI
457
458 _exception_oop(oop()),
459 _exception_pc(0),
460 _exception_handler_pc(0),
461 _is_method_handle_return(0),
462
463 _jni_active_critical(0),
464 _pending_jni_exception_check_fn(nullptr),
465 _depth_first_number(0),
466
467 // JVMTI PopFrame support
468 _popframe_condition(popframe_inactive),
469 _frames_to_pop_failed_realloc(0),
470
471 _cont_entry(nullptr),
472 _cont_fastpath(0),
473 _cont_fastpath_thread_state(1),
474 _held_monitor_count(0),
475 _jni_monitor_count(0),
476
477 _handshake(this),
478
479 _popframe_preserved_args(nullptr),
480 _popframe_preserved_args_size(0),
481
482 _jvmti_thread_state(nullptr),
483 _interp_only_mode(0),
484 _should_post_on_exceptions_flag(JNI_FALSE),
485 _thread_stat(new ThreadStatistics()),
486
487 _parker(),
488
489 _class_to_be_initialized(nullptr),
490
491 _SleepEvent(ParkEvent::Allocate(this)),
492
493 _lock_stack() {
494 set_jni_functions(jni_functions());
495
496 #if INCLUDE_JVMCI
497 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
498 if (JVMCICounterSize > 0) {
499 resize_counters(0, (int) JVMCICounterSize);
500 }
501 #endif // INCLUDE_JVMCI
502
503 // Setup safepoint state info for this thread
504 ThreadSafepointState::create(this);
505
506 SafepointMechanism::initialize_header(this);
507
508 set_requires_cross_modify_fence(false);
509
510 pd_initialize();
511 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
512 }
513
514 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
515 if (is_attaching_via_jni) {
516 _jni_attach_state = _attaching_via_jni;
517 }
518 }
519
520
521 // interrupt support
522
523 void JavaThread::interrupt() {
524 // All callers should have 'this' thread protected by a
525 // ThreadsListHandle so that it cannot terminate and deallocate
526 // itself.
527 debug_only(check_for_dangling_thread_pointer(this);)
528
529 // For Windows _interrupt_event
530 WINDOWS_ONLY(osthread()->set_interrupted(true);)
531
532 // For Thread.sleep
533 _SleepEvent->unpark();
534
535 // For JSR166 LockSupport.park
536 parker()->unpark();
537
538 // For ObjectMonitor and JvmtiRawMonitor
539 _ParkEvent->unpark();
540 }
541
542
543 bool JavaThread::is_interrupted(bool clear_interrupted) {
544 debug_only(check_for_dangling_thread_pointer(this);)
545
546 if (_threadObj.peek() == nullptr) {
547 // If there is no j.l.Thread then it is impossible to have
548 // been interrupted. We can find null during VM initialization
549 // or when a JNI thread is still in the process of attaching.
550 // In such cases this must be the current thread.
551 assert(this == Thread::current(), "invariant");
552 return false;
553 }
554
555 bool interrupted = java_lang_Thread::interrupted(threadObj());
556
557 // NOTE that since there is no "lock" around the interrupt and
558 // is_interrupted operations, there is the possibility that the
559 // interrupted flag will be "false" but that the
560 // low-level events will be in the signaled state. This is
561 // intentional. The effect of this is that Object.wait() and
562 // LockSupport.park() will appear to have a spurious wakeup, which
563 // is allowed and not harmful, and the possibility is so rare that
564 // it is not worth the added complexity to add yet another lock.
565 // For the sleep event an explicit reset is performed on entry
566 // to JavaThread::sleep, so there is no early return. It has also been
567 // recommended not to put the interrupted flag into the "event"
568 // structure because it hides the issue.
569 // Also, because there is no lock, we must only clear the interrupt
570 // state if we are going to report that we were interrupted; otherwise
571 // an interrupt that happens just after we read the field would be lost.
572 if (interrupted && clear_interrupted) {
573 assert(this == Thread::current(), "only the current thread can clear");
574 java_lang_Thread::set_interrupted(threadObj(), false);
575 WINDOWS_ONLY(osthread()->set_interrupted(false);)
576 }
577
578 return interrupted;
579 }
580
581 void JavaThread::block_if_vm_exited() {
582 if (_terminated == _vm_exited) {
583 // _vm_exited is set at safepoint, and Threads_lock is never released
584 // so we will block here forever.
585 // Here we can be doing a jump from a safe state to an unsafe state without
586 // proper transition, but it happens after the final safepoint has begun so
587 // this jump won't cause any safepoint problems.
588 set_thread_state(_thread_in_vm);
589 Threads_lock->lock();
590 ShouldNotReachHere();
591 }
592 }
593
594 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
595 _jni_attach_state = _not_attaching_via_jni;
596 set_entry_point(entry_point);
597 // Create the native thread itself.
598 // %note runtime_23
599 os::ThreadType thr_type = os::java_thread;
600 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
601 os::java_thread;
602 os::create_thread(this, thr_type, stack_sz);
603 // The _osthread may be null here because we ran out of memory (too many threads active).
604 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
605 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
606 // the exception consists of creating the exception object & initializing it, initialization
607 // will leave the VM via a JavaCall and then all locks must be unlocked).
608 //
609 // The thread is still suspended when we reach here. Thread must be explicit started
610 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
611 // by calling Threads:add. The reason why this is not done here, is because the thread
612 // object must be fully initialized (take a look at JVM_Start)
613 }
614
615 JavaThread::~JavaThread() {
616
617 // Enqueue OopHandles for release by the service thread.
618 add_oop_handles_for_release();
619
620 // Return the sleep event to the free list
621 ParkEvent::Release(_SleepEvent);
622 _SleepEvent = nullptr;
623
624 // Free any remaining previous UnrollBlock
625 vframeArray* old_array = vframe_array_last();
626
627 if (old_array != nullptr) {
628 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
629 old_array->set_unroll_block(nullptr);
630 delete old_info;
631 delete old_array;
632 }
633
634 JvmtiDeferredUpdates* updates = deferred_updates();
635 if (updates != nullptr) {
636 // This can only happen if thread is destroyed before deoptimization occurs.
637 assert(updates->count() > 0, "Updates holder not deleted");
638 // free deferred updates.
639 delete updates;
640 set_deferred_updates(nullptr);
641 }
642
643 // All Java related clean up happens in exit
644 ThreadSafepointState::destroy(this);
645 if (_thread_stat != nullptr) delete _thread_stat;
646
647 #if INCLUDE_JVMCI
648 if (JVMCICounterSize > 0) {
649 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
650 }
651 #endif // INCLUDE_JVMCI
652 }
653
654
655 // First JavaThread specific code executed by a new Java thread.
656 void JavaThread::pre_run() {
657 // empty - see comments in run()
658 }
659
660 // The main routine called by a new Java thread. This isn't overridden
661 // by subclasses, instead different subclasses define a different "entry_point"
662 // which defines the actual logic for that kind of thread.
663 void JavaThread::run() {
664 // initialize thread-local alloc buffer related fields
665 initialize_tlab();
666
667 _stack_overflow_state.create_stack_guard_pages();
668
669 cache_global_variables();
670
671 // Thread is now sufficiently initialized to be handled by the safepoint code as being
672 // in the VM. Change thread state from _thread_new to _thread_in_vm
673 assert(this->thread_state() == _thread_new, "wrong thread state");
674 set_thread_state(_thread_in_vm);
675
676 // Before a thread is on the threads list it is always safe, so after leaving the
677 // _thread_new we should emit a instruction barrier. The distance to modified code
678 // from here is probably far enough, but this is consistent and safe.
679 OrderAccess::cross_modify_fence();
680
681 assert(JavaThread::current() == this, "sanity check");
682 assert(!Thread::current()->owns_locks(), "sanity check");
683
684 DTRACE_THREAD_PROBE(start, this);
685
686 // This operation might block. We call that after all safepoint checks for a new thread has
687 // been completed.
688 set_active_handles(JNIHandleBlock::allocate_block());
689
690 if (JvmtiExport::should_post_thread_life()) {
691 JvmtiExport::post_thread_start(this);
692
693 }
694
695 // We call another function to do the rest so we are sure that the stack addresses used
696 // from there will be lower than the stack base just computed.
697 thread_main_inner();
698 }
699
700 void JavaThread::thread_main_inner() {
701 assert(JavaThread::current() == this, "sanity check");
702 assert(_threadObj.peek() != nullptr, "just checking");
703
704 // Execute thread entry point unless this thread has a pending exception.
705 // Note: Due to JVMTI StopThread we can have pending exceptions already!
706 if (!this->has_pending_exception()) {
707 {
708 ResourceMark rm(this);
709 this->set_native_thread_name(this->name());
710 }
711 HandleMark hm(this);
712 this->entry_point()(this, this);
713 }
714
715 DTRACE_THREAD_PROBE(stop, this);
716
717 // Cleanup is handled in post_run()
718 }
719
720 // Shared teardown for all JavaThreads
721 void JavaThread::post_run() {
722 this->exit(false);
723 this->unregister_thread_stack_with_NMT();
724 // Defer deletion to here to ensure 'this' is still referenceable in call_run
725 // for any shared tear-down.
726 this->smr_delete();
727 }
728
729 static void ensure_join(JavaThread* thread) {
730 // We do not need to grab the Threads_lock, since we are operating on ourself.
731 Handle threadObj(thread, thread->threadObj());
732 assert(threadObj.not_null(), "java thread object must exist");
733 ObjectLocker lock(threadObj, thread);
734 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
735 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
736 // Clear the native thread instance - this makes isAlive return false and allows the join()
737 // to complete once we've done the notify_all below
738 java_lang_Thread::set_thread(threadObj(), nullptr);
739 lock.notify_all(thread);
740 // Ignore pending exception, since we are exiting anyway
741 thread->clear_pending_exception();
742 }
743
744 static bool is_daemon(oop threadObj) {
745 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj));
746 }
747
748 // For any new cleanup additions, please check to see if they need to be applied to
749 // cleanup_failed_attach_current_thread as well.
750 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
751 assert(this == JavaThread::current(), "thread consistency check");
752 assert(!is_exiting(), "should not be exiting or terminated already");
753
754 elapsedTimer _timer_exit_phase1;
755 elapsedTimer _timer_exit_phase2;
756 elapsedTimer _timer_exit_phase3;
757 elapsedTimer _timer_exit_phase4;
758
759 if (log_is_enabled(Debug, os, thread, timer)) {
760 _timer_exit_phase1.start();
761 }
762
763 HandleMark hm(this);
764 Handle uncaught_exception(this, this->pending_exception());
765 this->clear_pending_exception();
766 Handle threadObj(this, this->threadObj());
767 assert(threadObj.not_null(), "Java thread object should be created");
768
769 if (!destroy_vm) {
770 if (uncaught_exception.not_null()) {
771 EXCEPTION_MARK;
772 // Call method Thread.dispatchUncaughtException().
773 Klass* thread_klass = vmClasses::Thread_klass();
774 JavaValue result(T_VOID);
775 JavaCalls::call_virtual(&result,
776 threadObj, thread_klass,
777 vmSymbols::dispatchUncaughtException_name(),
778 vmSymbols::throwable_void_signature(),
779 uncaught_exception,
780 THREAD);
781 if (HAS_PENDING_EXCEPTION) {
782 ResourceMark rm(this);
783 jio_fprintf(defaultStream::error_stream(),
784 "\nException: %s thrown from the UncaughtExceptionHandler"
785 " in thread \"%s\"\n",
786 pending_exception()->klass()->external_name(),
787 name());
788 CLEAR_PENDING_EXCEPTION;
789 }
790 }
791
792 if (!is_Compiler_thread()) {
793 // We have finished executing user-defined Java code and now have to do the
794 // implementation specific clean-up by calling Thread.exit(). We prevent any
795 // asynchronous exceptions from being delivered while in Thread.exit()
796 // to ensure the clean-up is not corrupted.
797 NoAsyncExceptionDeliveryMark _no_async(this);
798
799 EXCEPTION_MARK;
800 JavaValue result(T_VOID);
801 Klass* thread_klass = vmClasses::Thread_klass();
802 JavaCalls::call_virtual(&result,
803 threadObj, thread_klass,
804 vmSymbols::exit_method_name(),
805 vmSymbols::void_method_signature(),
806 THREAD);
807 CLEAR_PENDING_EXCEPTION;
808 }
809
810 // notify JVMTI
811 if (JvmtiExport::should_post_thread_life()) {
812 JvmtiExport::post_thread_end(this);
813 }
814 } else {
815 // before_exit() has already posted JVMTI THREAD_END events
816 }
817
818 // Cleanup any pending async exception now since we cannot access oops after
819 // BarrierSet::barrier_set()->on_thread_detach() has been executed.
820 if (has_async_exception_condition()) {
821 handshake_state()->clean_async_exception_operation();
822 }
823
824 // The careful dance between thread suspension and exit is handled here.
825 // Since we are in thread_in_vm state and suspension is done with handshakes,
826 // we can just put in the exiting state and it will be correctly handled.
827 // Also, no more async exceptions will be added to the queue after this point.
828 set_terminated(_thread_exiting);
829 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
830
831 if (log_is_enabled(Debug, os, thread, timer)) {
832 _timer_exit_phase1.stop();
833 _timer_exit_phase2.start();
834 }
835
836 // Capture daemon status before the thread is marked as terminated.
837 bool daemon = is_daemon(threadObj());
838
839 // Notify waiters on thread object. This has to be done after exit() is called
840 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
841 // group should have the destroyed bit set before waiters are notified).
842 ensure_join(this);
843 assert(!this->has_pending_exception(), "ensure_join should have cleared");
844
845 if (log_is_enabled(Debug, os, thread, timer)) {
846 _timer_exit_phase2.stop();
847 _timer_exit_phase3.start();
848 }
849 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
850 // held by this thread must be released. The spec does not distinguish
851 // between JNI-acquired and regular Java monitors. We can only see
852 // regular Java monitors here if monitor enter-exit matching is broken.
853 //
854 // ensure_join() ignores IllegalThreadStateExceptions, and so does
855 // ObjectSynchronizer::release_monitors_owned_by_thread().
856 if (exit_type == jni_detach) {
857 // Sanity check even though JNI DetachCurrentThread() would have
858 // returned JNI_ERR if there was a Java frame. JavaThread exit
859 // should be done executing Java code by the time we get here.
860 assert(!this->has_last_Java_frame(),
861 "should not have a Java frame when detaching or exiting");
862 ObjectSynchronizer::release_monitors_owned_by_thread(this);
863 assert(!this->has_pending_exception(), "release_monitors should have cleared");
864 }
865
866 // Since above code may not release JNI monitors and if someone forgot to do an
867 // JNI monitorexit, held count should be equal jni count.
868 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach).
869 assert(this->held_monitor_count() == this->jni_monitor_count(),
870 "held monitor count should be equal to jni: " INT64_FORMAT " != " INT64_FORMAT,
871 (int64_t)this->held_monitor_count(), (int64_t)this->jni_monitor_count());
872 if (CheckJNICalls && this->jni_monitor_count() > 0) {
873 // We would like a fatal here, but due to we never checked this before there
874 // is a lot of tests which breaks, even with an error log.
875 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.",
876 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id());
877 }
878
879 // These things needs to be done while we are still a Java Thread. Make sure that thread
880 // is in a consistent state, in case GC happens
881 JFR_ONLY(Jfr::on_thread_exit(this);)
882
883 if (active_handles() != nullptr) {
884 JNIHandleBlock* block = active_handles();
885 set_active_handles(nullptr);
886 JNIHandleBlock::release_block(block);
887 }
888
889 if (free_handle_block() != nullptr) {
890 JNIHandleBlock* block = free_handle_block();
891 set_free_handle_block(nullptr);
892 JNIHandleBlock::release_block(block);
893 }
894
895 // These have to be removed while this is still a valid thread.
896 _stack_overflow_state.remove_stack_guard_pages();
897
898 if (UseTLAB) {
899 tlab().retire();
900 }
901
902 if (JvmtiEnv::environments_might_exist()) {
903 JvmtiExport::cleanup_thread(this);
904 }
905
906 // We need to cache the thread name for logging purposes below as once
907 // we have called on_thread_detach this thread must not access any oops.
908 char* thread_name = nullptr;
909 if (log_is_enabled(Debug, os, thread, timer)) {
910 ResourceMark rm(this);
911 thread_name = os::strdup(name());
912 }
913
914 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
915 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
916 os::current_thread_id());
917
918 if (log_is_enabled(Debug, os, thread, timer)) {
919 _timer_exit_phase3.stop();
920 _timer_exit_phase4.start();
921 }
922
923 #if INCLUDE_JVMCI
924 if (JVMCICounterSize > 0) {
925 if (jvmci_counters_include(this)) {
926 for (int i = 0; i < JVMCICounterSize; i++) {
927 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
928 }
929 }
930 }
931 #endif // INCLUDE_JVMCI
932
933 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
934 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
935 Threads::remove(this, daemon);
936
937 if (log_is_enabled(Debug, os, thread, timer)) {
938 _timer_exit_phase4.stop();
939 log_debug(os, thread, timer)("name='%s'"
940 ", exit-phase1=" JLONG_FORMAT
941 ", exit-phase2=" JLONG_FORMAT
942 ", exit-phase3=" JLONG_FORMAT
943 ", exit-phase4=" JLONG_FORMAT,
944 thread_name,
945 _timer_exit_phase1.milliseconds(),
946 _timer_exit_phase2.milliseconds(),
947 _timer_exit_phase3.milliseconds(),
948 _timer_exit_phase4.milliseconds());
949 os::free(thread_name);
950 }
951 }
952
953 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
954 if (active_handles() != nullptr) {
955 JNIHandleBlock* block = active_handles();
956 set_active_handles(nullptr);
957 JNIHandleBlock::release_block(block);
958 }
959
960 if (free_handle_block() != nullptr) {
961 JNIHandleBlock* block = free_handle_block();
962 set_free_handle_block(nullptr);
963 JNIHandleBlock::release_block(block);
964 }
965
966 // These have to be removed while this is still a valid thread.
967 _stack_overflow_state.remove_stack_guard_pages();
968
969 if (UseTLAB) {
970 tlab().retire();
971 }
972
973 Threads::remove(this, is_daemon);
974 this->smr_delete();
975 }
976
977 JavaThread* JavaThread::active() {
978 Thread* thread = Thread::current();
979 if (thread->is_Java_thread()) {
980 return JavaThread::cast(thread);
981 } else {
982 assert(thread->is_VM_thread(), "this must be a vm thread");
983 VM_Operation* op = ((VMThread*) thread)->vm_operation();
984 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread());
985 return ret;
986 }
987 }
988
989 bool JavaThread::is_lock_owned(address adr) const {
990 assert(!UseFastLocking, "should not be called with fast-locking");
991 if (Thread::is_lock_owned(adr)) return true;
992
993 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
994 if (chunk->contains(adr)) return true;
995 }
996
997 return false;
998 }
999
1000 oop JavaThread::exception_oop() const {
1001 return Atomic::load(&_exception_oop);
1002 }
1003
1004 void JavaThread::set_exception_oop(oop o) {
1005 Atomic::store(&_exception_oop, o);
1006 }
1007
1008 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1009 chunk->set_next(monitor_chunks());
1010 set_monitor_chunks(chunk);
1011 }
1012
1013 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1014 guarantee(monitor_chunks() != nullptr, "must be non empty");
1015 if (monitor_chunks() == chunk) {
1016 set_monitor_chunks(chunk->next());
1017 } else {
1018 MonitorChunk* prev = monitor_chunks();
1019 while (prev->next() != chunk) prev = prev->next();
1020 prev->set_next(chunk->next());
1021 }
1022 }
1023
1024 void JavaThread::handle_special_runtime_exit_condition() {
1025 if (is_obj_deopt_suspend()) {
1026 frame_anchor()->make_walkable();
1027 wait_for_object_deoptimization();
1028 }
1029 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1030 }
1031
1032
1033 // Asynchronous exceptions support
1034 //
1035 void JavaThread::handle_async_exception(oop java_throwable) {
1036 assert(java_throwable != nullptr, "should have an _async_exception to throw");
1037 assert(!is_at_poll_safepoint(), "should have never called this method");
1038
1039 if (has_last_Java_frame()) {
1040 frame f = last_frame();
1041 if (f.is_runtime_frame()) {
1042 // If the topmost frame is a runtime stub, then we are calling into
1043 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1044 // must deoptimize the caller before continuing, as the compiled exception
1045 // handler table may not be valid.
1046 RegisterMap reg_map(this,
1047 RegisterMap::UpdateMap::skip,
1048 RegisterMap::ProcessFrames::include,
1049 RegisterMap::WalkContinuation::skip);
1050 frame compiled_frame = f.sender(®_map);
1051 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1052 Deoptimization::deoptimize(this, compiled_frame);
1053 }
1054 }
1055 }
1056
1057 // We cannot call Exceptions::_throw(...) here because we cannot block
1058 set_pending_exception(java_throwable, __FILE__, __LINE__);
1059
1060 clear_scopedValueBindings();
1061
1062 LogTarget(Info, exceptions) lt;
1063 if (lt.is_enabled()) {
1064 ResourceMark rm;
1065 LogStream ls(lt);
1066 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1067 if (has_last_Java_frame()) {
1068 frame f = last_frame();
1069 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1070 }
1071 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1072 }
1073 }
1074
1075 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1076 // Do not throw asynchronous exceptions against the compiler thread
1077 // or if the thread is already exiting.
1078 if (!can_call_java() || is_exiting()) {
1079 delete aeh;
1080 return;
1081 }
1082
1083 oop exception = aeh->exception();
1084 Handshake::execute(aeh, this); // Install asynchronous handshake
1085
1086 ResourceMark rm;
1087 if (log_is_enabled(Info, exceptions)) {
1088 log_info(exceptions)("Pending Async. exception installed of type: %s",
1089 InstanceKlass::cast(exception->klass())->external_name());
1090 }
1091 // for AbortVMOnException flag
1092 Exceptions::debug_check_abort(exception->klass()->external_name());
1093
1094 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1095 java_lang_Thread::set_interrupted(threadObj(), true);
1096 this->interrupt();
1097 }
1098
1099 class InstallAsyncExceptionHandshake : public HandshakeClosure {
1100 AsyncExceptionHandshake* _aeh;
1101 public:
1102 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1103 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1104 ~InstallAsyncExceptionHandshake() {
1105 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh.
1106 delete _aeh;
1107 }
1108 void do_thread(Thread* thr) {
1109 JavaThread* target = JavaThread::cast(thr);
1110 target->install_async_exception(_aeh);
1111 _aeh = nullptr;
1112 }
1113 };
1114
1115 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1116 OopHandle e(Universe::vm_global(), java_throwable);
1117 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1118 Handshake::execute(&iaeh, target);
1119 }
1120
1121 #if INCLUDE_JVMTI
1122 void JavaThread::set_is_in_VTMS_transition(bool val) {
1123 _is_in_VTMS_transition = val;
1124 }
1125
1126 #ifdef ASSERT
1127 void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1128 _is_VTMS_transition_disabler = val;
1129 }
1130 #endif
1131 #endif
1132
1133 // External suspension mechanism.
1134 //
1135 // Guarantees on return (for a valid target thread):
1136 // - Target thread will not execute any new bytecode.
1137 // - Target thread will not enter any new monitors.
1138 //
1139 bool JavaThread::java_suspend() {
1140 #if INCLUDE_JVMTI
1141 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1142 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1143 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1144 #endif
1145
1146 guarantee(Thread::is_JavaThread_protected(/* target */ this),
1147 "target JavaThread is not protected in calling context.");
1148 return this->handshake_state()->suspend();
1149 }
1150
1151 bool JavaThread::java_resume() {
1152 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1153 "missing ThreadsListHandle in calling context.");
1154 return this->handshake_state()->resume();
1155 }
1156
1157 // Wait for another thread to perform object reallocation and relocking on behalf of
1158 // this thread. The current thread is required to change to _thread_blocked in order
1159 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1160 // handshake safe, the other thread can complete the handshake used to synchronize
1161 // with this thread and then perform the reallocation and relocking.
1162 // See EscapeBarrier::sync_and_suspend_*()
1163
1164 void JavaThread::wait_for_object_deoptimization() {
1165 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1166 assert(this == Thread::current(), "invariant");
1167
1168 bool spin_wait = os::is_MP();
1169 do {
1170 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1171 // Wait for object deoptimization if requested.
1172 if (spin_wait) {
1173 // A single deoptimization is typically very short. Microbenchmarks
1174 // showed 5% better performance when spinning.
1175 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1176 SpinYield spin(spin_limit);
1177 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1178 spin.wait();
1179 }
1180 // Spin just once
1181 spin_wait = false;
1182 } else {
1183 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1184 if (is_obj_deopt_suspend()) {
1185 ml.wait();
1186 }
1187 }
1188 // A handshake for obj. deoptimization suspend could have been processed so
1189 // we must check after processing.
1190 } while (is_obj_deopt_suspend());
1191 }
1192
1193 #ifdef ASSERT
1194 // Verify the JavaThread has not yet been published in the Threads::list, and
1195 // hence doesn't need protection from concurrent access at this stage.
1196 void JavaThread::verify_not_published() {
1197 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1198 // since an unpublished JavaThread doesn't participate in the
1199 // Thread-SMR protocol for keeping a ThreadsList alive.
1200 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1201 }
1202 #endif
1203
1204 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1205 // pending, when _suspend_flags is non-zero or when we need to process a stack
1206 // watermark. Also check for pending async exceptions (except unsafe access error).
1207 // Note only the native==>Java barriers can call this function when thread state
1208 // is _thread_in_native_trans.
1209 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1210 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1211 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1212
1213 thread->set_thread_state(_thread_in_vm);
1214
1215 // Enable WXWrite: called directly from interpreter native wrapper.
1216 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1217
1218 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1219
1220 // After returning from native, it could be that the stack frames are not
1221 // yet safe to use. We catch such situations in the subsequent stack watermark
1222 // barrier, which will trap unsafe stack frames.
1223 StackWatermarkSet::before_unwind(thread);
1224 }
1225
1226 #ifndef PRODUCT
1227 // Deoptimization
1228 // Function for testing deoptimization
1229 void JavaThread::deoptimize() {
1230 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1231 bool deopt = false; // Dump stack only if a deopt actually happens.
1232 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1233 // Iterate over all frames in the thread and deoptimize
1234 for (; !fst.is_done(); fst.next()) {
1235 if (fst.current()->can_be_deoptimized()) {
1236
1237 if (only_at) {
1238 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1239 // consists of comma or carriage return separated numbers so
1240 // search for the current bci in that string.
1241 address pc = fst.current()->pc();
1242 nmethod* nm = (nmethod*) fst.current()->cb();
1243 ScopeDesc* sd = nm->scope_desc_at(pc);
1244 char buffer[8];
1245 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1246 size_t len = strlen(buffer);
1247 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1248 while (found != nullptr) {
1249 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1250 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1251 // Check that the bci found is bracketed by terminators.
1252 break;
1253 }
1254 found = strstr(found + 1, buffer);
1255 }
1256 if (!found) {
1257 continue;
1258 }
1259 }
1260
1261 if (DebugDeoptimization && !deopt) {
1262 deopt = true; // One-time only print before deopt
1263 tty->print_cr("[BEFORE Deoptimization]");
1264 trace_frames();
1265 trace_stack();
1266 }
1267 Deoptimization::deoptimize(this, *fst.current());
1268 }
1269 }
1270
1271 if (DebugDeoptimization && deopt) {
1272 tty->print_cr("[AFTER Deoptimization]");
1273 trace_frames();
1274 }
1275 }
1276
1277
1278 // Make zombies
1279 void JavaThread::make_zombies() {
1280 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1281 if (fst.current()->can_be_deoptimized()) {
1282 // it is a Java nmethod
1283 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1284 nm->make_not_entrant();
1285 }
1286 }
1287 }
1288 #endif // PRODUCT
1289
1290
1291 void JavaThread::deoptimize_marked_methods() {
1292 if (!has_last_Java_frame()) return;
1293 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1294 for (; !fst.is_done(); fst.next()) {
1295 if (fst.current()->should_be_deoptimized()) {
1296 Deoptimization::deoptimize(this, *fst.current());
1297 }
1298 }
1299 }
1300
1301 #ifdef ASSERT
1302 void JavaThread::verify_frame_info() {
1303 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1304 (has_last_Java_frame() && java_call_counter() > 0),
1305 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1306 has_last_Java_frame() ? "true" : "false", java_call_counter());
1307 }
1308 #endif
1309
1310 // Push on a new block of JNI handles.
1311 void JavaThread::push_jni_handle_block() {
1312 // Allocate a new block for JNI handles.
1313 // Inlined code from jni_PushLocalFrame()
1314 JNIHandleBlock* old_handles = active_handles();
1315 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1316 assert(old_handles != nullptr && new_handles != nullptr, "should not be null");
1317 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1318 set_active_handles(new_handles);
1319 }
1320
1321 // Pop off the current block of JNI handles.
1322 void JavaThread::pop_jni_handle_block() {
1323 // Release our JNI handle block
1324 JNIHandleBlock* old_handles = active_handles();
1325 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1326 assert(new_handles != nullptr, "should never set active handles to null");
1327 set_active_handles(new_handles);
1328 old_handles->set_pop_frame_link(nullptr);
1329 JNIHandleBlock::release_block(old_handles, this);
1330 }
1331
1332 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1333 // Verify that the deferred card marks have been flushed.
1334 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1335
1336 // Traverse the GCHandles
1337 Thread::oops_do_no_frames(f, cf);
1338
1339 if (active_handles() != nullptr) {
1340 active_handles()->oops_do(f);
1341 }
1342
1343 DEBUG_ONLY(verify_frame_info();)
1344
1345 if (has_last_Java_frame()) {
1346 // Traverse the monitor chunks
1347 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1348 chunk->oops_do(f);
1349 }
1350 }
1351
1352 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!");
1353 // If we have deferred set_locals there might be oops waiting to be
1354 // written
1355 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1356 if (list != nullptr) {
1357 for (int i = 0; i < list->length(); i++) {
1358 list->at(i)->oops_do(f);
1359 }
1360 }
1361
1362 // Traverse instance variables at the end since the GC may be moving things
1363 // around using this function
1364 f->do_oop((oop*) &_vm_result);
1365 f->do_oop((oop*) &_exception_oop);
1366 #if INCLUDE_JVMCI
1367 f->do_oop((oop*) &_jvmci_reserved_oop0);
1368 #endif
1369
1370 if (jvmti_thread_state() != nullptr) {
1371 jvmti_thread_state()->oops_do(f, cf);
1372 }
1373
1374 // The continuation oops are really on the stack. But there is typically at most
1375 // one of those per thread, so we handle them here in the oops_do_no_frames part
1376 // so that we don't have to sprinkle as many stack watermark checks where these
1377 // oops are used. We just need to make sure the thread has started processing.
1378 ContinuationEntry* entry = _cont_entry;
1379 while (entry != nullptr) {
1380 f->do_oop((oop*)entry->cont_addr());
1381 f->do_oop((oop*)entry->chunk_addr());
1382 entry = entry->parent();
1383 }
1384
1385 if (!UseHeavyMonitors && UseFastLocking) {
1386 lock_stack().oops_do(f);
1387 }
1388 }
1389
1390 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
1391 if (!has_last_Java_frame()) {
1392 return;
1393 }
1394 // Finish any pending lazy GC activity for the frames
1395 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc);
1396 // Traverse the execution stack
1397 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1398 fst.current()->oops_do(f, cf, fst.register_map());
1399 }
1400 }
1401
1402 #ifdef ASSERT
1403 void JavaThread::verify_states_for_handshake() {
1404 // This checks that the thread has a correct frame state during a handshake.
1405 verify_frame_info();
1406 }
1407 #endif
1408
1409 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1410 DEBUG_ONLY(verify_frame_info();)
1411 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1412
1413 if (has_last_Java_frame()) {
1414 // Traverse the execution stack
1415 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1416 fst.current()->nmethods_do(cf);
1417 }
1418 }
1419
1420 if (jvmti_thread_state() != nullptr) {
1421 jvmti_thread_state()->nmethods_do(cf);
1422 }
1423 }
1424
1425 void JavaThread::metadata_do(MetadataClosure* f) {
1426 if (has_last_Java_frame()) {
1427 // Traverse the execution stack to call f() on the methods in the stack
1428 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1429 fst.current()->metadata_do(f);
1430 }
1431 } else if (is_Compiler_thread()) {
1432 // need to walk ciMetadata in current compile tasks to keep alive.
1433 CompilerThread* ct = (CompilerThread*)this;
1434 if (ct->env() != nullptr) {
1435 ct->env()->metadata_do(f);
1436 }
1437 CompileTask* task = ct->task();
1438 if (task != nullptr) {
1439 task->metadata_do(f);
1440 }
1441 }
1442 }
1443
1444 // Printing
1445 const char* _get_thread_state_name(JavaThreadState _thread_state) {
1446 switch (_thread_state) {
1447 case _thread_uninitialized: return "_thread_uninitialized";
1448 case _thread_new: return "_thread_new";
1449 case _thread_new_trans: return "_thread_new_trans";
1450 case _thread_in_native: return "_thread_in_native";
1451 case _thread_in_native_trans: return "_thread_in_native_trans";
1452 case _thread_in_vm: return "_thread_in_vm";
1453 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1454 case _thread_in_Java: return "_thread_in_Java";
1455 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1456 case _thread_blocked: return "_thread_blocked";
1457 case _thread_blocked_trans: return "_thread_blocked_trans";
1458 default: return "unknown thread state";
1459 }
1460 }
1461
1462 void JavaThread::print_thread_state_on(outputStream *st) const {
1463 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1464 }
1465
1466 // Called by Threads::print() for VM_PrintThreads operation
1467 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1468 st->print_raw("\"");
1469 st->print_raw(name());
1470 st->print_raw("\" ");
1471 oop thread_oop = threadObj();
1472 if (thread_oop != nullptr) {
1473 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1474 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1475 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1476 }
1477 Thread::print_on(st, print_extended_info);
1478 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1479 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1480 if (thread_oop != nullptr) {
1481 if (is_vthread_mounted()) {
1482 oop vt = vthread();
1483 assert(vt != nullptr, "");
1484 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1485 } else {
1486 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1487 }
1488 }
1489 #ifndef PRODUCT
1490 _safepoint_state->print_on(st);
1491 #endif // PRODUCT
1492 if (is_Compiler_thread()) {
1493 CompileTask *task = ((CompilerThread*)this)->task();
1494 if (task != nullptr) {
1495 st->print(" Compiling: ");
1496 task->print(st, nullptr, true, false);
1497 } else {
1498 st->print(" No compile task");
1499 }
1500 st->cr();
1501 }
1502 }
1503
1504 void JavaThread::print() const { print_on(tty); }
1505
1506 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1507 st->print("%s", get_thread_name_string(buf, buflen));
1508 }
1509
1510 // Called by fatal error handler. The difference between this and
1511 // JavaThread::print() is that we can't grab lock or allocate memory.
1512 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1513 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1514 Thread* current = Thread::current_or_null_safe();
1515 assert(current != nullptr, "cannot be called by a detached thread");
1516 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1517 // Only access threadObj() if current thread is not a JavaThread
1518 // or if it is a JavaThread that can safely access oops.
1519 oop thread_obj = threadObj();
1520 if (thread_obj != nullptr) {
1521 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
1522 }
1523 }
1524 st->print(" [");
1525 st->print("%s", _get_thread_state_name(_thread_state));
1526 if (osthread()) {
1527 st->print(", id=%d", osthread()->thread_id());
1528 }
1529 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
1530 p2i(stack_end()), p2i(stack_base()));
1531 st->print("]");
1532
1533 ThreadsSMRSupport::print_info_on(this, st);
1534 return;
1535 }
1536
1537
1538 // Verification
1539
1540 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1541 // ignore if there is no stack
1542 if (!has_last_Java_frame()) return;
1543 // traverse the stack frames. Starts from top frame.
1544 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1545 frame* fr = fst.current();
1546 f(fr, fst.register_map());
1547 }
1548 }
1549
1550 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1551
1552 void JavaThread::verify() {
1553 // Verify oops in the thread.
1554 oops_do(&VerifyOopClosure::verify_oop, nullptr);
1555
1556 // Verify the stack frames.
1557 frames_do(frame_verify);
1558 }
1559
1560 // CR 6300358 (sub-CR 2137150)
1561 // Most callers of this method assume that it can't return null but a
1562 // thread may not have a name whilst it is in the process of attaching to
1563 // the VM - see CR 6412693, and there are places where a JavaThread can be
1564 // seen prior to having its threadObj set (e.g., JNI attaching threads and
1565 // if vm exit occurs during initialization). These cases can all be accounted
1566 // for such that this method never returns null.
1567 const char* JavaThread::name() const {
1568 if (Thread::is_JavaThread_protected(/* target */ this)) {
1569 // The target JavaThread is protected so get_thread_name_string() is safe:
1570 return get_thread_name_string();
1571 }
1572
1573 // The target JavaThread is not protected so we return the default:
1574 return Thread::name();
1575 }
1576
1577 // Returns a non-null representation of this thread's name, or a suitable
1578 // descriptive string if there is no set name.
1579 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1580 const char* name_str;
1581 #ifdef ASSERT
1582 Thread* current = Thread::current_or_null_safe();
1583 assert(current != nullptr, "cannot be called by a detached thread");
1584 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1585 // Only access threadObj() if current thread is not a JavaThread
1586 // or if it is a JavaThread that can safely access oops.
1587 #endif
1588 oop thread_obj = threadObj();
1589 if (thread_obj != nullptr) {
1590 oop name = java_lang_Thread::name(thread_obj);
1591 if (name != nullptr) {
1592 if (buf == nullptr) {
1593 name_str = java_lang_String::as_utf8_string(name);
1594 } else {
1595 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1596 }
1597 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1598 name_str = "<no-name - thread is attaching>";
1599 } else {
1600 name_str = "<un-named>";
1601 }
1602 } else {
1603 name_str = Thread::name();
1604 }
1605 #ifdef ASSERT
1606 } else {
1607 // Current JavaThread has exited...
1608 if (current == this) {
1609 // ... and is asking about itself:
1610 name_str = "<no-name - current JavaThread has exited>";
1611 } else {
1612 // ... and it can't safely determine this JavaThread's name so
1613 // use the default thread name.
1614 name_str = Thread::name();
1615 }
1616 }
1617 #endif
1618 assert(name_str != nullptr, "unexpected null thread name");
1619 return name_str;
1620 }
1621
1622 // Helper to extract the name from the thread oop for logging.
1623 const char* JavaThread::name_for(oop thread_obj) {
1624 assert(thread_obj != nullptr, "precondition");
1625 oop name = java_lang_Thread::name(thread_obj);
1626 const char* name_str;
1627 if (name != nullptr) {
1628 name_str = java_lang_String::as_utf8_string(name);
1629 } else {
1630 name_str = "<un-named>";
1631 }
1632 return name_str;
1633 }
1634
1635 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1636
1637 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1638 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1639 // Link Java Thread object <-> C++ Thread
1640
1641 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1642 // and put it into a new Handle. The Handle "thread_oop" can then
1643 // be used to pass the C++ thread object to other methods.
1644
1645 // Set the Java level thread object (jthread) field of the
1646 // new thread (a JavaThread *) to C++ thread object using the
1647 // "thread_oop" handle.
1648
1649 // Set the thread field (a JavaThread *) of the
1650 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1651
1652 Handle thread_oop(Thread::current(),
1653 JNIHandles::resolve_non_null(jni_thread));
1654 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1655 "must be initialized");
1656 set_threadOopHandles(thread_oop());
1657 java_lang_Thread::set_thread(thread_oop(), this);
1658
1659 if (prio == NoPriority) {
1660 prio = java_lang_Thread::priority(thread_oop());
1661 assert(prio != NoPriority, "A valid priority should be present");
1662 }
1663
1664 // Push the Java priority down to the native thread; needs Threads_lock
1665 Thread::set_priority(this, prio);
1666
1667 // Add the new thread to the Threads list and set it in motion.
1668 // We must have threads lock in order to call Threads::add.
1669 // It is crucial that we do not block before the thread is
1670 // added to the Threads list for if a GC happens, then the java_thread oop
1671 // will not be visited by GC.
1672 Threads::add(this);
1673 }
1674
1675 oop JavaThread::current_park_blocker() {
1676 // Support for JSR-166 locks
1677 oop thread_oop = threadObj();
1678 if (thread_oop != nullptr) {
1679 return java_lang_Thread::park_blocker(thread_oop);
1680 }
1681 return nullptr;
1682 }
1683
1684 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1685 // This is the external format, selecting the platform or vthread
1686 // as applicable, and allowing for a native-only stack.
1687 void JavaThread::print_jni_stack() {
1688 assert(this == JavaThread::current(), "Can't print stack of other threads");
1689 if (!has_last_Java_frame()) {
1690 ResourceMark rm(this);
1691 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
1692 if (buf == nullptr) {
1693 tty->print_cr("Unable to print native stack - out of memory");
1694 return;
1695 }
1696 frame f = os::current_frame();
1697 VMError::print_native_stack(tty, f, this, true /*print_source_info */,
1698 -1 /* max stack */, buf, O_BUFLEN);
1699 } else {
1700 print_active_stack_on(tty);
1701 }
1702 }
1703
1704 void JavaThread::print_stack_on(outputStream* st) {
1705 if (!has_last_Java_frame()) return;
1706
1707 Thread* current_thread = Thread::current();
1708 ResourceMark rm(current_thread);
1709 HandleMark hm(current_thread);
1710
1711 RegisterMap reg_map(this,
1712 RegisterMap::UpdateMap::include,
1713 RegisterMap::ProcessFrames::include,
1714 RegisterMap::WalkContinuation::skip);
1715 vframe* start_vf = platform_thread_last_java_vframe(®_map);
1716 int count = 0;
1717 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1718 if (f->is_java_frame()) {
1719 javaVFrame* jvf = javaVFrame::cast(f);
1720 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1721
1722 // Print out lock information
1723 if (JavaMonitorsInStackTrace) {
1724 jvf->print_lock_info_on(st, count);
1725 }
1726 } else {
1727 // Ignore non-Java frames
1728 }
1729
1730 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1731 count++;
1732 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1733 }
1734 }
1735
1736 void JavaThread::print_vthread_stack_on(outputStream* st) {
1737 assert(is_vthread_mounted(), "Caller should have checked this");
1738 assert(has_last_Java_frame(), "must be");
1739
1740 Thread* current_thread = Thread::current();
1741 ResourceMark rm(current_thread);
1742 HandleMark hm(current_thread);
1743
1744 RegisterMap reg_map(this,
1745 RegisterMap::UpdateMap::include,
1746 RegisterMap::ProcessFrames::include,
1747 RegisterMap::WalkContinuation::include);
1748 ContinuationEntry* cont_entry = last_continuation();
1749 vframe* start_vf = last_java_vframe(®_map);
1750 int count = 0;
1751 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1752 // Watch for end of vthread stack
1753 if (Continuation::is_continuation_enterSpecial(f->fr())) {
1754 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), "");
1755 if (cont_entry->is_virtual_thread()) {
1756 break;
1757 }
1758 cont_entry = cont_entry->parent();
1759 }
1760 if (f->is_java_frame()) {
1761 javaVFrame* jvf = javaVFrame::cast(f);
1762 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1763
1764 // Print out lock information
1765 if (JavaMonitorsInStackTrace) {
1766 jvf->print_lock_info_on(st, count);
1767 }
1768 } else {
1769 // Ignore non-Java frames
1770 }
1771
1772 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1773 count++;
1774 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1775 }
1776 }
1777
1778 void JavaThread::print_active_stack_on(outputStream* st) {
1779 if (is_vthread_mounted()) {
1780 print_vthread_stack_on(st);
1781 } else {
1782 print_stack_on(st);
1783 }
1784 }
1785
1786 #if INCLUDE_JVMTI
1787 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1788 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1789 set_jvmti_vthread(thread_oop);
1790
1791 // unbind current JvmtiThreadState from JavaThread
1792 JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1793
1794 // bind new JvmtiThreadState to JavaThread
1795 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1796
1797 return jvmti_thread_state();
1798 }
1799 #endif
1800
1801 // JVMTI PopFrame support
1802 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1803 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments");
1804 if (in_bytes(size_in_bytes) != 0) {
1805 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1806 _popframe_preserved_args_size = in_bytes(size_in_bytes);
1807 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1808 }
1809 }
1810
1811 void* JavaThread::popframe_preserved_args() {
1812 return _popframe_preserved_args;
1813 }
1814
1815 ByteSize JavaThread::popframe_preserved_args_size() {
1816 return in_ByteSize(_popframe_preserved_args_size);
1817 }
1818
1819 WordSize JavaThread::popframe_preserved_args_size_in_words() {
1820 int sz = in_bytes(popframe_preserved_args_size());
1821 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1822 return in_WordSize(sz / wordSize);
1823 }
1824
1825 void JavaThread::popframe_free_preserved_args() {
1826 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice");
1827 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1828 _popframe_preserved_args = nullptr;
1829 _popframe_preserved_args_size = 0;
1830 }
1831
1832 #ifndef PRODUCT
1833
1834 void JavaThread::trace_frames() {
1835 tty->print_cr("[Describe stack]");
1836 int frame_no = 1;
1837 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1838 tty->print(" %d. ", frame_no++);
1839 fst.current()->print_value_on(tty, this);
1840 tty->cr();
1841 }
1842 }
1843
1844 class PrintAndVerifyOopClosure: public OopClosure {
1845 protected:
1846 template <class T> inline void do_oop_work(T* p) {
1847 oop obj = RawAccess<>::oop_load(p);
1848 if (obj == nullptr) return;
1849 tty->print(INTPTR_FORMAT ": ", p2i(p));
1850 if (oopDesc::is_oop_or_null(obj)) {
1851 if (obj->is_objArray()) {
1852 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1853 } else {
1854 obj->print();
1855 }
1856 } else {
1857 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1858 }
1859 tty->cr();
1860 }
1861 public:
1862 virtual void do_oop(oop* p) { do_oop_work(p); }
1863 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1864 };
1865
1866 #ifdef ASSERT
1867 // Print or validate the layout of stack frames
1868 void JavaThread::print_frame_layout(int depth, bool validate_only) {
1869 ResourceMark rm;
1870 PreserveExceptionMark pm(this);
1871 FrameValues values;
1872 int frame_no = 0;
1873 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1874 fst.current()->describe(values, ++frame_no, fst.register_map());
1875 if (depth == frame_no) break;
1876 }
1877 Continuation::describe(values);
1878 if (validate_only) {
1879 values.validate();
1880 } else {
1881 tty->print_cr("[Describe stack layout]");
1882 values.print(this);
1883 }
1884 }
1885 #endif
1886
1887 void JavaThread::trace_stack_from(vframe* start_vf) {
1888 ResourceMark rm;
1889 int vframe_no = 1;
1890 for (vframe* f = start_vf; f; f = f->sender()) {
1891 if (f->is_java_frame()) {
1892 javaVFrame::cast(f)->print_activation(vframe_no++);
1893 } else {
1894 f->print();
1895 }
1896 if (vframe_no > StackPrintLimit) {
1897 tty->print_cr("...<more frames>...");
1898 return;
1899 }
1900 }
1901 }
1902
1903
1904 void JavaThread::trace_stack() {
1905 if (!has_last_Java_frame()) return;
1906 Thread* current_thread = Thread::current();
1907 ResourceMark rm(current_thread);
1908 HandleMark hm(current_thread);
1909 RegisterMap reg_map(this,
1910 RegisterMap::UpdateMap::include,
1911 RegisterMap::ProcessFrames::include,
1912 RegisterMap::WalkContinuation::skip);
1913 trace_stack_from(last_java_vframe(®_map));
1914 }
1915
1916
1917 #endif // PRODUCT
1918
1919 void JavaThread::inc_held_monitor_count(int i, bool jni) {
1920 #ifdef SUPPORT_MONITOR_COUNT
1921 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count);
1922 _held_monitor_count += i;
1923 if (jni) {
1924 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count);
1925 _jni_monitor_count += i;
1926 }
1927 #endif
1928 }
1929
1930 void JavaThread::dec_held_monitor_count(int i, bool jni) {
1931 #ifdef SUPPORT_MONITOR_COUNT
1932 _held_monitor_count -= i;
1933 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count);
1934 if (jni) {
1935 _jni_monitor_count -= i;
1936 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count);
1937 }
1938 #endif
1939 }
1940
1941 frame JavaThread::vthread_last_frame() {
1942 assert (is_vthread_mounted(), "Virtual thread not mounted");
1943 return last_frame();
1944 }
1945
1946 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
1947 const ContinuationEntry* entry = vthread_continuation();
1948 guarantee (entry != nullptr, "Not a carrier thread");
1949 frame f = entry->to_frame();
1950 if (reg_map->process_frames()) {
1951 entry->flush_stack_processing(this);
1952 }
1953 entry->update_register_map(reg_map);
1954 return f.sender(reg_map);
1955 }
1956
1957 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
1958 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
1959 }
1960
1961 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
1962 assert(reg_map != nullptr, "a map must be given");
1963 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
1964 if (vf->is_java_frame()) return javaVFrame::cast(vf);
1965 }
1966 return nullptr;
1967 }
1968
1969 Klass* JavaThread::security_get_caller_class(int depth) {
1970 ResetNoHandleMark rnhm;
1971 HandleMark hm(Thread::current());
1972
1973 vframeStream vfst(this);
1974 vfst.security_get_caller_frame(depth);
1975 if (!vfst.at_end()) {
1976 return vfst.method()->method_holder();
1977 }
1978 return nullptr;
1979 }
1980
1981 // java.lang.Thread.sleep support
1982 // Returns true if sleep time elapsed as expected, and false
1983 // if the thread was interrupted.
1984 bool JavaThread::sleep(jlong millis) {
1985 assert(this == Thread::current(), "thread consistency check");
1986
1987 ParkEvent * const slp = this->_SleepEvent;
1988 // Because there can be races with thread interruption sending an unpark()
1989 // to the event, we explicitly reset it here to avoid an immediate return.
1990 // The actual interrupt state will be checked before we park().
1991 slp->reset();
1992 // Thread interruption establishes a happens-before ordering in the
1993 // Java Memory Model, so we need to ensure we synchronize with the
1994 // interrupt state.
1995 OrderAccess::fence();
1996
1997 jlong prevtime = os::javaTimeNanos();
1998
1999 for (;;) {
2000 // interruption has precedence over timing out
2001 if (this->is_interrupted(true)) {
2002 return false;
2003 }
2004
2005 if (millis <= 0) {
2006 return true;
2007 }
2008
2009 {
2010 ThreadBlockInVM tbivm(this);
2011 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2012 slp->park(millis);
2013 }
2014
2015 // Update elapsed time tracking
2016 jlong newtime = os::javaTimeNanos();
2017 if (newtime - prevtime < 0) {
2018 // time moving backwards, should only happen if no monotonic clock
2019 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2020 assert(false,
2021 "unexpected time moving backwards detected in JavaThread::sleep()");
2022 } else {
2023 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2024 }
2025 prevtime = newtime;
2026 }
2027 }
2028
2029 // Last thread running calls java.lang.Shutdown.shutdown()
2030 void JavaThread::invoke_shutdown_hooks() {
2031 HandleMark hm(this);
2032
2033 // We could get here with a pending exception, if so clear it now or
2034 // it will cause MetaspaceShared::link_shared_classes to
2035 // fail for dynamic dump.
2036 if (this->has_pending_exception()) {
2037 this->clear_pending_exception();
2038 }
2039
2040 #if INCLUDE_CDS
2041 // Link all classes for dynamic CDS dumping before vm exit.
2042 // Same operation is being done in JVM_BeforeHalt for handling the
2043 // case where the application calls System.exit().
2044 if (DynamicArchive::should_dump_at_vm_exit()) {
2045 DynamicArchive::prepare_for_dump_at_exit();
2046 }
2047 #endif
2048
2049 EXCEPTION_MARK;
2050 Klass* shutdown_klass =
2051 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
2052 THREAD);
2053 if (shutdown_klass != nullptr) {
2054 // SystemDictionary::resolve_or_null will return null if there was
2055 // an exception. If we cannot load the Shutdown class, just don't
2056 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
2057 // won't be run. Note that if a shutdown hook was registered,
2058 // the Shutdown class would have already been loaded
2059 // (Runtime.addShutdownHook will load it).
2060 JavaValue result(T_VOID);
2061 JavaCalls::call_static(&result,
2062 shutdown_klass,
2063 vmSymbols::shutdown_name(),
2064 vmSymbols::void_method_signature(),
2065 THREAD);
2066 }
2067 CLEAR_PENDING_EXCEPTION;
2068 }
2069
2070 #ifndef PRODUCT
2071 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
2072 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
2073 }
2074 #endif
2075
2076 // Helper function to create the java.lang.Thread object for a
2077 // VM-internal thread. The thread will have the given name, and be
2078 // a member of the "system" ThreadGroup.
2079 Handle JavaThread::create_system_thread_object(const char* name,
2080 bool is_visible, TRAPS) {
2081 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2082
2083 // Initialize thread_oop to put it into the system threadGroup.
2084 // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2085 Handle thread_group(THREAD, Universe::system_thread_group());
2086 Handle thread_oop =
2087 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2088 vmSymbols::threadgroup_string_void_signature(),
2089 thread_group,
2090 string,
2091 CHECK_NH);
2092
2093 return thread_oop;
2094 }
2095
2096 // Starts the target JavaThread as a daemon of the given priority, and
2097 // bound to the given java.lang.Thread instance.
2098 // The Threads_lock is held for the duration.
2099 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2100 Handle thread_oop, ThreadPriority prio) {
2101
2102 assert(target->osthread() != nullptr, "target thread is not properly initialized");
2103
2104 MutexLocker mu(current, Threads_lock);
2105
2106 // Initialize the fields of the thread_oop first.
2107
2108 java_lang_Thread::set_thread(thread_oop(), target); // isAlive == true now
2109
2110 if (prio != NoPriority) {
2111 java_lang_Thread::set_priority(thread_oop(), prio);
2112 // Note: we don't call os::set_priority here. Possibly we should,
2113 // else all threads should call it themselves when they first run.
2114 }
2115
2116 java_lang_Thread::set_daemon(thread_oop());
2117
2118 // Now bind the thread_oop to the target JavaThread.
2119 target->set_threadOopHandles(thread_oop());
2120
2121 Threads::add(target); // target is now visible for safepoint/handshake
2122 Thread::start(target);
2123 }
2124
2125 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2126 // At this point it may be possible that no osthread was created for the
2127 // JavaThread due to lack of resources. However, since this must work
2128 // for critical system threads just check and abort if this fails.
2129 if (thread->osthread() == nullptr) {
2130 // This isn't really an OOM condition, but historically this is what
2131 // we report.
2132 vm_exit_during_initialization("java.lang.OutOfMemoryError",
2133 os::native_thread_creation_failed_msg());
2134 }
2135 }
2136
2137 // Deferred OopHandle release support.
2138
2139 class OopHandleList : public CHeapObj<mtInternal> {
2140 static const int _count = 4;
2141 OopHandle _handles[_count];
2142 OopHandleList* _next;
2143 int _index;
2144 public:
2145 OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2146 void add(OopHandle h) {
2147 assert(_index < _count, "too many additions");
2148 _handles[_index++] = h;
2149 }
2150 ~OopHandleList() {
2151 assert(_index == _count, "usage error");
2152 for (int i = 0; i < _index; i++) {
2153 _handles[i].release(JavaThread::thread_oop_storage());
2154 }
2155 }
2156 OopHandleList* next() const { return _next; }
2157 };
2158
2159 OopHandleList* JavaThread::_oop_handle_list = nullptr;
2160
2161 // Called by the ServiceThread to do the work of releasing
2162 // the OopHandles.
2163 void JavaThread::release_oop_handles() {
2164 OopHandleList* list;
2165 {
2166 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2167 list = _oop_handle_list;
2168 _oop_handle_list = nullptr;
2169 }
2170 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2171
2172 while (list != nullptr) {
2173 OopHandleList* l = list;
2174 list = l->next();
2175 delete l;
2176 }
2177 }
2178
2179 // Add our OopHandles for later release.
2180 void JavaThread::add_oop_handles_for_release() {
2181 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2182 OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2183 new_head->add(_threadObj);
2184 new_head->add(_vthread);
2185 new_head->add(_jvmti_vthread);
2186 new_head->add(_scopedValueCache);
2187 _oop_handle_list = new_head;
2188 Service_lock->notify_all();
2189 }