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/inlineKlass.hpp"
52 #include "oops/instanceKlass.hpp"
53 #include "oops/klass.inline.hpp"
54 #include "oops/oop.inline.hpp"
55 #include "oops/oopHandle.inline.hpp"
56 #include "oops/verifyOopClosure.hpp"
57 #include "prims/jvm_misc.hpp"
58 #include "prims/jvmtiDeferredUpdates.hpp"
59 #include "prims/jvmtiExport.hpp"
60 #include "prims/jvmtiThreadState.inline.hpp"
61 #include "runtime/atomic.hpp"
62 #include "runtime/continuation.hpp"
63 #include "runtime/continuationEntry.inline.hpp"
64 #include "runtime/continuationHelper.inline.hpp"
65 #include "runtime/deoptimization.hpp"
66 #include "runtime/frame.inline.hpp"
67 #include "runtime/handles.inline.hpp"
68 #include "runtime/handshake.hpp"
69 #include "runtime/interfaceSupport.inline.hpp"
70 #include "runtime/java.hpp"
71 #include "runtime/javaCalls.hpp"
72 #include "runtime/javaThread.inline.hpp"
73 #include "runtime/jniHandles.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 CHECK);
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 CHECK);
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 // Don't complain if running a debugging command.
381 if (DebuggingContext::is_enabled()) return;
382
383 // Check NoSafepointVerifier, which is implied by locks taken that can be
384 // shared with the VM thread. This makes sure that no locks with allow_vm_block
385 // are held.
386 check_possible_safepoint();
387
388 if (thread_state() != _thread_in_vm) {
389 fatal("LEAF method calling lock?");
390 }
391
392 if (GCALotAtAllSafepoints) {
393 // We could enter a safepoint here and thus have a gc
394 InterfaceSupport::check_gc_alot();
395 }
396 }
397 #endif // ASSERT
398
399 // A JavaThread is a normal Java thread
400
401 JavaThread::JavaThread() :
402 // Initialize fields
403
404 _on_thread_list(false),
405 DEBUG_ONLY(_java_call_counter(0) COMMA)
406 _entry_point(nullptr),
407 _deopt_mark(nullptr),
408 _deopt_nmethod(nullptr),
409 _vframe_array_head(nullptr),
410 _vframe_array_last(nullptr),
411 _jvmti_deferred_updates(nullptr),
412 _callee_target(nullptr),
413 _vm_result(nullptr),
414 _vm_result_2(nullptr),
415
416 _current_pending_monitor(nullptr),
417 _current_pending_monitor_is_from_java(true),
418 _current_waiting_monitor(nullptr),
419 _active_handles(nullptr),
420 _free_handle_block(nullptr),
421 _Stalled(0),
422
423 _monitor_chunks(nullptr),
424
425 _suspend_flags(0),
426
427 _thread_state(_thread_new),
428 _saved_exception_pc(nullptr),
429 #ifdef ASSERT
430 _no_safepoint_count(0),
431 _visited_for_critical_count(false),
432 #endif
433
434 _terminated(_not_terminated),
435 _in_deopt_handler(0),
436 _doing_unsafe_access(false),
437 _do_not_unlock_if_synchronized(false),
438 #if INCLUDE_JVMTI
439 _carrier_thread_suspended(false),
440 _is_in_VTMS_transition(false),
441 _is_in_tmp_VTMS_transition(false),
442 #ifdef ASSERT
443 _is_VTMS_transition_disabler(false),
444 #endif
445 #endif
446 _jni_attach_state(_not_attaching_via_jni),
447 #if INCLUDE_JVMCI
448 _pending_deoptimization(-1),
449 _pending_monitorenter(false),
450 _pending_transfer_to_interpreter(false),
451 _in_retryable_allocation(false),
452 _pending_failed_speculation(0),
453 _jvmci{nullptr},
454 _libjvmci_runtime(nullptr),
455 _jvmci_counters(nullptr),
456 _jvmci_reserved0(0),
457 _jvmci_reserved1(0),
458 _jvmci_reserved_oop0(nullptr),
459 #endif // INCLUDE_JVMCI
460
461 _exception_oop(oop()),
462 _exception_pc(0),
463 _exception_handler_pc(0),
464 _is_method_handle_return(0),
465
466 _jni_active_critical(0),
467 _pending_jni_exception_check_fn(nullptr),
468 _depth_first_number(0),
469
470 // JVMTI PopFrame support
471 _popframe_condition(popframe_inactive),
472 _frames_to_pop_failed_realloc(0),
473
474 _cont_entry(nullptr),
475 _cont_fastpath(0),
476 _cont_fastpath_thread_state(1),
477 _held_monitor_count(0),
478 _jni_monitor_count(0),
479
480 _handshake(this),
481
482 _popframe_preserved_args(nullptr),
483 _popframe_preserved_args_size(0),
484
485 _jvmti_thread_state(nullptr),
486 _interp_only_mode(0),
487 _should_post_on_exceptions_flag(JNI_FALSE),
488 _thread_stat(new ThreadStatistics()),
489
490 _parker(),
491
492 _class_to_be_initialized(nullptr),
493
494 _SleepEvent(ParkEvent::Allocate(this))
495 {
496 set_jni_functions(jni_functions());
497
498 #if INCLUDE_JVMCI
499 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
500 if (JVMCICounterSize > 0) {
501 resize_counters(0, (int) JVMCICounterSize);
502 }
503 #endif // INCLUDE_JVMCI
504
505 // Setup safepoint state info for this thread
506 ThreadSafepointState::create(this);
507
508 SafepointMechanism::initialize_header(this);
509
510 set_requires_cross_modify_fence(false);
511
512 pd_initialize();
513 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
514 }
515
516 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
517 if (is_attaching_via_jni) {
518 _jni_attach_state = _attaching_via_jni;
519 }
520 }
521
522
523 // interrupt support
524
525 void JavaThread::interrupt() {
526 // All callers should have 'this' thread protected by a
527 // ThreadsListHandle so that it cannot terminate and deallocate
528 // itself.
529 debug_only(check_for_dangling_thread_pointer(this);)
530
531 // For Windows _interrupt_event
532 WINDOWS_ONLY(osthread()->set_interrupted(true);)
533
534 // For Thread.sleep
535 _SleepEvent->unpark();
536
537 // For JSR166 LockSupport.park
538 parker()->unpark();
539
540 // For ObjectMonitor and JvmtiRawMonitor
541 _ParkEvent->unpark();
542 }
543
544
545 bool JavaThread::is_interrupted(bool clear_interrupted) {
546 debug_only(check_for_dangling_thread_pointer(this);)
547
548 if (_threadObj.peek() == nullptr) {
549 // If there is no j.l.Thread then it is impossible to have
550 // been interrupted. We can find null during VM initialization
551 // or when a JNI thread is still in the process of attaching.
552 // In such cases this must be the current thread.
553 assert(this == Thread::current(), "invariant");
554 return false;
555 }
556
557 bool interrupted = java_lang_Thread::interrupted(threadObj());
558
559 // NOTE that since there is no "lock" around the interrupt and
560 // is_interrupted operations, there is the possibility that the
561 // interrupted flag will be "false" but that the
562 // low-level events will be in the signaled state. This is
563 // intentional. The effect of this is that Object.wait() and
564 // LockSupport.park() will appear to have a spurious wakeup, which
565 // is allowed and not harmful, and the possibility is so rare that
566 // it is not worth the added complexity to add yet another lock.
567 // For the sleep event an explicit reset is performed on entry
568 // to JavaThread::sleep, so there is no early return. It has also been
569 // recommended not to put the interrupted flag into the "event"
570 // structure because it hides the issue.
571 // Also, because there is no lock, we must only clear the interrupt
572 // state if we are going to report that we were interrupted; otherwise
573 // an interrupt that happens just after we read the field would be lost.
574 if (interrupted && clear_interrupted) {
575 assert(this == Thread::current(), "only the current thread can clear");
576 java_lang_Thread::set_interrupted(threadObj(), false);
577 WINDOWS_ONLY(osthread()->set_interrupted(false);)
578 }
579
580 return interrupted;
581 }
582
583 void JavaThread::block_if_vm_exited() {
584 if (_terminated == _vm_exited) {
585 // _vm_exited is set at safepoint, and Threads_lock is never released
586 // so we will block here forever.
587 // Here we can be doing a jump from a safe state to an unsafe state without
588 // proper transition, but it happens after the final safepoint has begun so
589 // this jump won't cause any safepoint problems.
590 set_thread_state(_thread_in_vm);
591 Threads_lock->lock();
592 ShouldNotReachHere();
593 }
594 }
595
596 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
597 _jni_attach_state = _not_attaching_via_jni;
598 set_entry_point(entry_point);
599 // Create the native thread itself.
600 // %note runtime_23
601 os::ThreadType thr_type = os::java_thread;
602 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
603 os::java_thread;
604 os::create_thread(this, thr_type, stack_sz);
605 // The _osthread may be null here because we ran out of memory (too many threads active).
606 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
607 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
608 // the exception consists of creating the exception object & initializing it, initialization
609 // will leave the VM via a JavaCall and then all locks must be unlocked).
610 //
611 // The thread is still suspended when we reach here. Thread must be explicit started
612 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
613 // by calling Threads:add. The reason why this is not done here, is because the thread
614 // object must be fully initialized (take a look at JVM_Start)
615 }
616
617 JavaThread::~JavaThread() {
618
619 // Enqueue OopHandles for release by the service thread.
620 add_oop_handles_for_release();
621
622 // Return the sleep event to the free list
623 ParkEvent::Release(_SleepEvent);
624 _SleepEvent = nullptr;
625
626 // Free any remaining previous UnrollBlock
627 vframeArray* old_array = vframe_array_last();
628
629 if (old_array != nullptr) {
630 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
631 old_array->set_unroll_block(nullptr);
632 delete old_info;
633 delete old_array;
634 }
635
636 JvmtiDeferredUpdates* updates = deferred_updates();
637 if (updates != nullptr) {
638 // This can only happen if thread is destroyed before deoptimization occurs.
639 assert(updates->count() > 0, "Updates holder not deleted");
640 // free deferred updates.
641 delete updates;
642 set_deferred_updates(nullptr);
643 }
644
645 // All Java related clean up happens in exit
646 ThreadSafepointState::destroy(this);
647 if (_thread_stat != nullptr) delete _thread_stat;
648
649 #if INCLUDE_JVMCI
650 if (JVMCICounterSize > 0) {
651 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
652 }
653 #endif // INCLUDE_JVMCI
654 }
655
656
657 // First JavaThread specific code executed by a new Java thread.
658 void JavaThread::pre_run() {
659 // empty - see comments in run()
660 }
661
662 // The main routine called by a new Java thread. This isn't overridden
663 // by subclasses, instead different subclasses define a different "entry_point"
664 // which defines the actual logic for that kind of thread.
665 void JavaThread::run() {
666 // initialize thread-local alloc buffer related fields
667 initialize_tlab();
668
669 _stack_overflow_state.create_stack_guard_pages();
670
671 cache_global_variables();
672
673 // Thread is now sufficiently initialized to be handled by the safepoint code as being
674 // in the VM. Change thread state from _thread_new to _thread_in_vm
675 assert(this->thread_state() == _thread_new, "wrong thread state");
676 set_thread_state(_thread_in_vm);
677
678 // Before a thread is on the threads list it is always safe, so after leaving the
679 // _thread_new we should emit a instruction barrier. The distance to modified code
680 // from here is probably far enough, but this is consistent and safe.
681 OrderAccess::cross_modify_fence();
682
683 assert(JavaThread::current() == this, "sanity check");
684 assert(!Thread::current()->owns_locks(), "sanity check");
685
686 DTRACE_THREAD_PROBE(start, this);
687
688 // This operation might block. We call that after all safepoint checks for a new thread has
689 // been completed.
690 set_active_handles(JNIHandleBlock::allocate_block());
691
692 if (JvmtiExport::should_post_thread_life()) {
693 JvmtiExport::post_thread_start(this);
694
695 }
696
697 if (AlwaysPreTouchStacks) {
698 pretouch_stack();
699 }
700
701 // We call another function to do the rest so we are sure that the stack addresses used
702 // from there will be lower than the stack base just computed.
703 thread_main_inner();
704 }
705
706 void JavaThread::thread_main_inner() {
707 assert(JavaThread::current() == this, "sanity check");
708 assert(_threadObj.peek() != nullptr, "just checking");
709
710 // Execute thread entry point unless this thread has a pending exception.
711 // Note: Due to JVMTI StopThread we can have pending exceptions already!
712 if (!this->has_pending_exception()) {
713 {
714 ResourceMark rm(this);
715 this->set_native_thread_name(this->name());
716 }
717 HandleMark hm(this);
718 this->entry_point()(this, this);
719 }
720
721 DTRACE_THREAD_PROBE(stop, this);
722
723 // Cleanup is handled in post_run()
724 }
725
726 // Shared teardown for all JavaThreads
727 void JavaThread::post_run() {
728 this->exit(false);
729 this->unregister_thread_stack_with_NMT();
730 // Defer deletion to here to ensure 'this' is still referenceable in call_run
731 // for any shared tear-down.
732 this->smr_delete();
733 }
734
735 static void ensure_join(JavaThread* thread) {
736 // We do not need to grab the Threads_lock, since we are operating on ourself.
737 Handle threadObj(thread, thread->threadObj());
738 assert(threadObj.not_null(), "java thread object must exist");
739 ObjectLocker lock(threadObj, thread);
740 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
741 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
742 // Clear the native thread instance - this makes isAlive return false and allows the join()
743 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model
744 // requirements.
745 OrderAccess::release();
746 java_lang_Thread::set_thread(threadObj(), nullptr);
747 lock.notify_all(thread);
748 // Ignore pending exception, since we are exiting anyway
749 thread->clear_pending_exception();
750 }
751
752 static bool is_daemon(oop threadObj) {
753 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj));
754 }
755
756 // For any new cleanup additions, please check to see if they need to be applied to
757 // cleanup_failed_attach_current_thread as well.
758 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
759 assert(this == JavaThread::current(), "thread consistency check");
760 assert(!is_exiting(), "should not be exiting or terminated already");
761
762 elapsedTimer _timer_exit_phase1;
763 elapsedTimer _timer_exit_phase2;
764 elapsedTimer _timer_exit_phase3;
765 elapsedTimer _timer_exit_phase4;
766
767 if (log_is_enabled(Debug, os, thread, timer)) {
768 _timer_exit_phase1.start();
769 }
770
771 HandleMark hm(this);
772 Handle uncaught_exception(this, this->pending_exception());
773 this->clear_pending_exception();
774 Handle threadObj(this, this->threadObj());
775 assert(threadObj.not_null(), "Java thread object should be created");
776
777 if (!destroy_vm) {
778 if (uncaught_exception.not_null()) {
779 EXCEPTION_MARK;
780 // Call method Thread.dispatchUncaughtException().
781 Klass* thread_klass = vmClasses::Thread_klass();
782 JavaValue result(T_VOID);
783 JavaCalls::call_virtual(&result,
784 threadObj, thread_klass,
785 vmSymbols::dispatchUncaughtException_name(),
786 vmSymbols::throwable_void_signature(),
787 uncaught_exception,
788 THREAD);
789 if (HAS_PENDING_EXCEPTION) {
790 ResourceMark rm(this);
791 jio_fprintf(defaultStream::error_stream(),
792 "\nException: %s thrown from the UncaughtExceptionHandler"
793 " in thread \"%s\"\n",
794 pending_exception()->klass()->external_name(),
795 name());
796 CLEAR_PENDING_EXCEPTION;
797 }
798 }
799
800 if (!is_Compiler_thread()) {
801 // We have finished executing user-defined Java code and now have to do the
802 // implementation specific clean-up by calling Thread.exit(). We prevent any
803 // asynchronous exceptions from being delivered while in Thread.exit()
804 // to ensure the clean-up is not corrupted.
805 NoAsyncExceptionDeliveryMark _no_async(this);
806
807 EXCEPTION_MARK;
808 JavaValue result(T_VOID);
809 Klass* thread_klass = vmClasses::Thread_klass();
810 JavaCalls::call_virtual(&result,
811 threadObj, thread_klass,
812 vmSymbols::exit_method_name(),
813 vmSymbols::void_method_signature(),
814 THREAD);
815 CLEAR_PENDING_EXCEPTION;
816 }
817
818 // notify JVMTI
819 if (JvmtiExport::should_post_thread_life()) {
820 JvmtiExport::post_thread_end(this);
821 }
822 } else {
823 // before_exit() has already posted JVMTI THREAD_END events
824 }
825
826 // Cleanup any pending async exception now since we cannot access oops after
827 // BarrierSet::barrier_set()->on_thread_detach() has been executed.
828 if (has_async_exception_condition()) {
829 handshake_state()->clean_async_exception_operation();
830 }
831
832 // The careful dance between thread suspension and exit is handled here.
833 // Since we are in thread_in_vm state and suspension is done with handshakes,
834 // we can just put in the exiting state and it will be correctly handled.
835 // Also, no more async exceptions will be added to the queue after this point.
836 set_terminated(_thread_exiting);
837 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
838
839 if (log_is_enabled(Debug, os, thread, timer)) {
840 _timer_exit_phase1.stop();
841 _timer_exit_phase2.start();
842 }
843
844 // Capture daemon status before the thread is marked as terminated.
845 bool daemon = is_daemon(threadObj());
846
847 // Notify waiters on thread object. This has to be done after exit() is called
848 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
849 // group should have the destroyed bit set before waiters are notified).
850 ensure_join(this);
851 assert(!this->has_pending_exception(), "ensure_join should have cleared");
852
853 if (log_is_enabled(Debug, os, thread, timer)) {
854 _timer_exit_phase2.stop();
855 _timer_exit_phase3.start();
856 }
857 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
858 // held by this thread must be released. The spec does not distinguish
859 // between JNI-acquired and regular Java monitors. We can only see
860 // regular Java monitors here if monitor enter-exit matching is broken.
861 //
862 // ensure_join() ignores IllegalThreadStateExceptions, and so does
863 // ObjectSynchronizer::release_monitors_owned_by_thread().
864 if (exit_type == jni_detach) {
865 // Sanity check even though JNI DetachCurrentThread() would have
866 // returned JNI_ERR if there was a Java frame. JavaThread exit
867 // should be done executing Java code by the time we get here.
868 assert(!this->has_last_Java_frame(),
869 "should not have a Java frame when detaching or exiting");
870 ObjectSynchronizer::release_monitors_owned_by_thread(this);
871 assert(!this->has_pending_exception(), "release_monitors should have cleared");
872 }
873
874 // Since above code may not release JNI monitors and if someone forgot to do an
875 // JNI monitorexit, held count should be equal jni count.
876 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach).
877 assert(this->held_monitor_count() == this->jni_monitor_count(),
878 "held monitor count should be equal to jni: " INT64_FORMAT " != " INT64_FORMAT,
879 (int64_t)this->held_monitor_count(), (int64_t)this->jni_monitor_count());
880 if (CheckJNICalls && this->jni_monitor_count() > 0) {
881 // We would like a fatal here, but due to we never checked this before there
882 // is a lot of tests which breaks, even with an error log.
883 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.",
884 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id());
885 }
886
887 // These things needs to be done while we are still a Java Thread. Make sure that thread
888 // is in a consistent state, in case GC happens
889 JFR_ONLY(Jfr::on_thread_exit(this);)
890
891 if (active_handles() != nullptr) {
892 JNIHandleBlock* block = active_handles();
893 set_active_handles(nullptr);
894 JNIHandleBlock::release_block(block);
895 }
896
897 if (free_handle_block() != nullptr) {
898 JNIHandleBlock* block = free_handle_block();
899 set_free_handle_block(nullptr);
900 JNIHandleBlock::release_block(block);
901 }
902
903 // These have to be removed while this is still a valid thread.
904 _stack_overflow_state.remove_stack_guard_pages();
905
906 if (UseTLAB) {
907 tlab().retire();
908 }
909
910 if (JvmtiEnv::environments_might_exist()) {
911 JvmtiExport::cleanup_thread(this);
912 }
913
914 // We need to cache the thread name for logging purposes below as once
915 // we have called on_thread_detach this thread must not access any oops.
916 char* thread_name = nullptr;
917 if (log_is_enabled(Debug, os, thread, timer)) {
918 ResourceMark rm(this);
919 thread_name = os::strdup(name());
920 }
921
922 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
923 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
924 os::current_thread_id());
925
926 if (log_is_enabled(Debug, os, thread, timer)) {
927 _timer_exit_phase3.stop();
928 _timer_exit_phase4.start();
929 }
930
931 #if INCLUDE_JVMCI
932 if (JVMCICounterSize > 0) {
933 if (jvmci_counters_include(this)) {
934 for (int i = 0; i < JVMCICounterSize; i++) {
935 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
936 }
937 }
938 }
939 #endif // INCLUDE_JVMCI
940
941 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
942 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
943 Threads::remove(this, daemon);
944
945 if (log_is_enabled(Debug, os, thread, timer)) {
946 _timer_exit_phase4.stop();
947 log_debug(os, thread, timer)("name='%s'"
948 ", exit-phase1=" JLONG_FORMAT
949 ", exit-phase2=" JLONG_FORMAT
950 ", exit-phase3=" JLONG_FORMAT
951 ", exit-phase4=" JLONG_FORMAT,
952 thread_name,
953 _timer_exit_phase1.milliseconds(),
954 _timer_exit_phase2.milliseconds(),
955 _timer_exit_phase3.milliseconds(),
956 _timer_exit_phase4.milliseconds());
957 os::free(thread_name);
958 }
959 }
960
961 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
962 if (active_handles() != nullptr) {
963 JNIHandleBlock* block = active_handles();
964 set_active_handles(nullptr);
965 JNIHandleBlock::release_block(block);
966 }
967
968 if (free_handle_block() != nullptr) {
969 JNIHandleBlock* block = free_handle_block();
970 set_free_handle_block(nullptr);
971 JNIHandleBlock::release_block(block);
972 }
973
974 // These have to be removed while this is still a valid thread.
975 _stack_overflow_state.remove_stack_guard_pages();
976
977 if (UseTLAB) {
978 tlab().retire();
979 }
980
981 Threads::remove(this, is_daemon);
982 this->smr_delete();
983 }
984
985 JavaThread* JavaThread::active() {
986 Thread* thread = Thread::current();
987 if (thread->is_Java_thread()) {
988 return JavaThread::cast(thread);
989 } else {
990 assert(thread->is_VM_thread(), "this must be a vm thread");
991 VM_Operation* op = ((VMThread*) thread)->vm_operation();
992 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread());
993 return ret;
994 }
995 }
996
997 bool JavaThread::is_lock_owned(address adr) const {
998 if (Thread::is_lock_owned(adr)) return true;
999
1000 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1001 if (chunk->contains(adr)) return true;
1002 }
1003
1004 return false;
1005 }
1006
1007 oop JavaThread::exception_oop() const {
1008 return Atomic::load(&_exception_oop);
1009 }
1010
1011 void JavaThread::set_exception_oop(oop o) {
1012 Atomic::store(&_exception_oop, o);
1013 }
1014
1015 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1016 chunk->set_next(monitor_chunks());
1017 set_monitor_chunks(chunk);
1018 }
1019
1020 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1021 guarantee(monitor_chunks() != nullptr, "must be non empty");
1022 if (monitor_chunks() == chunk) {
1023 set_monitor_chunks(chunk->next());
1024 } else {
1025 MonitorChunk* prev = monitor_chunks();
1026 while (prev->next() != chunk) prev = prev->next();
1027 prev->set_next(chunk->next());
1028 }
1029 }
1030
1031 void JavaThread::handle_special_runtime_exit_condition() {
1032 if (is_obj_deopt_suspend()) {
1033 frame_anchor()->make_walkable();
1034 wait_for_object_deoptimization();
1035 }
1036 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1037 }
1038
1039
1040 // Asynchronous exceptions support
1041 //
1042 void JavaThread::handle_async_exception(oop java_throwable) {
1043 assert(java_throwable != nullptr, "should have an _async_exception to throw");
1044 assert(!is_at_poll_safepoint(), "should have never called this method");
1045
1046 if (has_last_Java_frame()) {
1047 frame f = last_frame();
1048 if (f.is_runtime_frame()) {
1049 // If the topmost frame is a runtime stub, then we are calling into
1050 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1051 // must deoptimize the caller before continuing, as the compiled exception
1052 // handler table may not be valid.
1053 RegisterMap reg_map(this,
1054 RegisterMap::UpdateMap::skip,
1055 RegisterMap::ProcessFrames::include,
1056 RegisterMap::WalkContinuation::skip);
1057 frame compiled_frame = f.sender(®_map);
1058 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1059 Deoptimization::deoptimize(this, compiled_frame);
1060 }
1061 }
1062 }
1063
1064 // We cannot call Exceptions::_throw(...) here because we cannot block
1065 set_pending_exception(java_throwable, __FILE__, __LINE__);
1066
1067 clear_scopedValueBindings();
1068
1069 LogTarget(Info, exceptions) lt;
1070 if (lt.is_enabled()) {
1071 ResourceMark rm;
1072 LogStream ls(lt);
1073 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1074 if (has_last_Java_frame()) {
1075 frame f = last_frame();
1076 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1077 }
1078 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1079 }
1080 }
1081
1082 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1083 // Do not throw asynchronous exceptions against the compiler thread
1084 // or if the thread is already exiting.
1085 if (!can_call_java() || is_exiting()) {
1086 delete aeh;
1087 return;
1088 }
1089
1090 oop exception = aeh->exception();
1091 Handshake::execute(aeh, this); // Install asynchronous handshake
1092
1093 ResourceMark rm;
1094 if (log_is_enabled(Info, exceptions)) {
1095 log_info(exceptions)("Pending Async. exception installed of type: %s",
1096 InstanceKlass::cast(exception->klass())->external_name());
1097 }
1098 // for AbortVMOnException flag
1099 Exceptions::debug_check_abort(exception->klass()->external_name());
1100
1101 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1102 java_lang_Thread::set_interrupted(threadObj(), true);
1103 this->interrupt();
1104 }
1105
1106 class InstallAsyncExceptionHandshake : public HandshakeClosure {
1107 AsyncExceptionHandshake* _aeh;
1108 public:
1109 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1110 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1111 ~InstallAsyncExceptionHandshake() {
1112 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh.
1113 delete _aeh;
1114 }
1115 void do_thread(Thread* thr) {
1116 JavaThread* target = JavaThread::cast(thr);
1117 target->install_async_exception(_aeh);
1118 _aeh = nullptr;
1119 }
1120 };
1121
1122 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1123 OopHandle e(Universe::vm_global(), java_throwable);
1124 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1125 Handshake::execute(&iaeh, target);
1126 }
1127
1128 #if INCLUDE_JVMTI
1129 void JavaThread::set_is_in_VTMS_transition(bool val) {
1130 _is_in_VTMS_transition = val;
1131 }
1132
1133 #ifdef ASSERT
1134 void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1135 _is_VTMS_transition_disabler = val;
1136 }
1137 #endif
1138 #endif
1139
1140 // External suspension mechanism.
1141 //
1142 // Guarantees on return (for a valid target thread):
1143 // - Target thread will not execute any new bytecode.
1144 // - Target thread will not enter any new monitors.
1145 //
1146 bool JavaThread::java_suspend() {
1147 #if INCLUDE_JVMTI
1148 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1149 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1150 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1151 #endif
1152
1153 guarantee(Thread::is_JavaThread_protected(/* target */ this),
1154 "target JavaThread is not protected in calling context.");
1155 return this->handshake_state()->suspend();
1156 }
1157
1158 bool JavaThread::java_resume() {
1159 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1160 "missing ThreadsListHandle in calling context.");
1161 return this->handshake_state()->resume();
1162 }
1163
1164 // Wait for another thread to perform object reallocation and relocking on behalf of
1165 // this thread. The current thread is required to change to _thread_blocked in order
1166 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1167 // handshake safe, the other thread can complete the handshake used to synchronize
1168 // with this thread and then perform the reallocation and relocking.
1169 // See EscapeBarrier::sync_and_suspend_*()
1170
1171 void JavaThread::wait_for_object_deoptimization() {
1172 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1173 assert(this == Thread::current(), "invariant");
1174
1175 bool spin_wait = os::is_MP();
1176 do {
1177 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1178 // Wait for object deoptimization if requested.
1179 if (spin_wait) {
1180 // A single deoptimization is typically very short. Microbenchmarks
1181 // showed 5% better performance when spinning.
1182 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1183 SpinYield spin(spin_limit);
1184 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1185 spin.wait();
1186 }
1187 // Spin just once
1188 spin_wait = false;
1189 } else {
1190 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1191 if (is_obj_deopt_suspend()) {
1192 ml.wait();
1193 }
1194 }
1195 // A handshake for obj. deoptimization suspend could have been processed so
1196 // we must check after processing.
1197 } while (is_obj_deopt_suspend());
1198 }
1199
1200 #ifdef ASSERT
1201 // Verify the JavaThread has not yet been published in the Threads::list, and
1202 // hence doesn't need protection from concurrent access at this stage.
1203 void JavaThread::verify_not_published() {
1204 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1205 // since an unpublished JavaThread doesn't participate in the
1206 // Thread-SMR protocol for keeping a ThreadsList alive.
1207 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1208 }
1209 #endif
1210
1211 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1212 // pending, when _suspend_flags is non-zero or when we need to process a stack
1213 // watermark. Also check for pending async exceptions (except unsafe access error).
1214 // Note only the native==>Java barriers can call this function when thread state
1215 // is _thread_in_native_trans.
1216 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1217 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1218 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1219
1220 thread->set_thread_state(_thread_in_vm);
1221
1222 // Enable WXWrite: called directly from interpreter native wrapper.
1223 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1224
1225 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1226
1227 // After returning from native, it could be that the stack frames are not
1228 // yet safe to use. We catch such situations in the subsequent stack watermark
1229 // barrier, which will trap unsafe stack frames.
1230 StackWatermarkSet::before_unwind(thread);
1231 }
1232
1233 #ifndef PRODUCT
1234 // Deoptimization
1235 // Function for testing deoptimization
1236 void JavaThread::deoptimize() {
1237 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1238 bool deopt = false; // Dump stack only if a deopt actually happens.
1239 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1240 // Iterate over all frames in the thread and deoptimize
1241 for (; !fst.is_done(); fst.next()) {
1242 if (fst.current()->can_be_deoptimized()) {
1243
1244 if (only_at) {
1245 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1246 // consists of comma or carriage return separated numbers so
1247 // search for the current bci in that string.
1248 address pc = fst.current()->pc();
1249 nmethod* nm = (nmethod*) fst.current()->cb();
1250 ScopeDesc* sd = nm->scope_desc_at(pc);
1251 char buffer[8];
1252 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1253 size_t len = strlen(buffer);
1254 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1255 while (found != nullptr) {
1256 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1257 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1258 // Check that the bci found is bracketed by terminators.
1259 break;
1260 }
1261 found = strstr(found + 1, buffer);
1262 }
1263 if (!found) {
1264 continue;
1265 }
1266 }
1267
1268 if (DebugDeoptimization && !deopt) {
1269 deopt = true; // One-time only print before deopt
1270 tty->print_cr("[BEFORE Deoptimization]");
1271 trace_frames();
1272 trace_stack();
1273 }
1274 Deoptimization::deoptimize(this, *fst.current());
1275 }
1276 }
1277
1278 if (DebugDeoptimization && deopt) {
1279 tty->print_cr("[AFTER Deoptimization]");
1280 trace_frames();
1281 }
1282 }
1283
1284
1285 // Make zombies
1286 void JavaThread::make_zombies() {
1287 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1288 if (fst.current()->can_be_deoptimized()) {
1289 // it is a Java nmethod
1290 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1291 nm->make_not_entrant();
1292 }
1293 }
1294 }
1295 #endif // PRODUCT
1296
1297
1298 void JavaThread::deoptimize_marked_methods() {
1299 if (!has_last_Java_frame()) return;
1300 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1301 for (; !fst.is_done(); fst.next()) {
1302 if (fst.current()->should_be_deoptimized()) {
1303 Deoptimization::deoptimize(this, *fst.current());
1304 }
1305 }
1306 }
1307
1308 #ifdef ASSERT
1309 void JavaThread::verify_frame_info() {
1310 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1311 (has_last_Java_frame() && java_call_counter() > 0),
1312 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1313 has_last_Java_frame() ? "true" : "false", java_call_counter());
1314 }
1315 #endif
1316
1317 // Push on a new block of JNI handles.
1318 void JavaThread::push_jni_handle_block() {
1319 // Allocate a new block for JNI handles.
1320 // Inlined code from jni_PushLocalFrame()
1321 JNIHandleBlock* old_handles = active_handles();
1322 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1323 assert(old_handles != nullptr && new_handles != nullptr, "should not be null");
1324 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1325 set_active_handles(new_handles);
1326 }
1327
1328 // Pop off the current block of JNI handles.
1329 void JavaThread::pop_jni_handle_block() {
1330 // Release our JNI handle block
1331 JNIHandleBlock* old_handles = active_handles();
1332 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1333 assert(new_handles != nullptr, "should never set active handles to null");
1334 set_active_handles(new_handles);
1335 old_handles->set_pop_frame_link(nullptr);
1336 JNIHandleBlock::release_block(old_handles, this);
1337 }
1338
1339 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1340 // Verify that the deferred card marks have been flushed.
1341 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1342
1343 // Traverse the GCHandles
1344 Thread::oops_do_no_frames(f, cf);
1345
1346 if (active_handles() != nullptr) {
1347 active_handles()->oops_do(f);
1348 }
1349
1350 DEBUG_ONLY(verify_frame_info();)
1351
1352 if (has_last_Java_frame()) {
1353 // Traverse the monitor chunks
1354 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1355 chunk->oops_do(f);
1356 }
1357 }
1358
1359 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!");
1360 // If we have deferred set_locals there might be oops waiting to be
1361 // written
1362 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1363 if (list != nullptr) {
1364 for (int i = 0; i < list->length(); i++) {
1365 list->at(i)->oops_do(f);
1366 }
1367 }
1368
1369 // Traverse instance variables at the end since the GC may be moving things
1370 // around using this function
1371 f->do_oop((oop*) &_vm_result);
1372 f->do_oop((oop*) &_exception_oop);
1373 #if INCLUDE_JVMCI
1374 f->do_oop((oop*) &_jvmci_reserved_oop0);
1375 #endif
1376
1377 if (jvmti_thread_state() != nullptr) {
1378 jvmti_thread_state()->oops_do(f, cf);
1379 }
1380
1381 // The continuation oops are really on the stack. But there is typically at most
1382 // one of those per thread, so we handle them here in the oops_do_no_frames part
1383 // so that we don't have to sprinkle as many stack watermark checks where these
1384 // oops are used. We just need to make sure the thread has started processing.
1385 ContinuationEntry* entry = _cont_entry;
1386 while (entry != nullptr) {
1387 f->do_oop((oop*)entry->cont_addr());
1388 f->do_oop((oop*)entry->chunk_addr());
1389 entry = entry->parent();
1390 }
1391 }
1392
1393 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
1394 if (!has_last_Java_frame()) {
1395 return;
1396 }
1397 // Finish any pending lazy GC activity for the frames
1398 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc);
1399 // Traverse the execution stack
1400 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1401 fst.current()->oops_do(f, cf, fst.register_map());
1402 }
1403 }
1404
1405 #ifdef ASSERT
1406 void JavaThread::verify_states_for_handshake() {
1407 // This checks that the thread has a correct frame state during a handshake.
1408 verify_frame_info();
1409 }
1410 #endif
1411
1412 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1413 DEBUG_ONLY(verify_frame_info();)
1414 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1415
1416 if (has_last_Java_frame()) {
1417 // Traverse the execution stack
1418 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1419 fst.current()->nmethods_do(cf);
1420 }
1421 }
1422
1423 if (jvmti_thread_state() != nullptr) {
1424 jvmti_thread_state()->nmethods_do(cf);
1425 }
1426 }
1427
1428 void JavaThread::metadata_do(MetadataClosure* f) {
1429 if (has_last_Java_frame()) {
1430 // Traverse the execution stack to call f() on the methods in the stack
1431 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1432 fst.current()->metadata_do(f);
1433 }
1434 } else if (is_Compiler_thread()) {
1435 // need to walk ciMetadata in current compile tasks to keep alive.
1436 CompilerThread* ct = (CompilerThread*)this;
1437 if (ct->env() != nullptr) {
1438 ct->env()->metadata_do(f);
1439 }
1440 CompileTask* task = ct->task();
1441 if (task != nullptr) {
1442 task->metadata_do(f);
1443 }
1444 }
1445 }
1446
1447 // Printing
1448 const char* _get_thread_state_name(JavaThreadState _thread_state) {
1449 switch (_thread_state) {
1450 case _thread_uninitialized: return "_thread_uninitialized";
1451 case _thread_new: return "_thread_new";
1452 case _thread_new_trans: return "_thread_new_trans";
1453 case _thread_in_native: return "_thread_in_native";
1454 case _thread_in_native_trans: return "_thread_in_native_trans";
1455 case _thread_in_vm: return "_thread_in_vm";
1456 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1457 case _thread_in_Java: return "_thread_in_Java";
1458 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1459 case _thread_blocked: return "_thread_blocked";
1460 case _thread_blocked_trans: return "_thread_blocked_trans";
1461 default: return "unknown thread state";
1462 }
1463 }
1464
1465 void JavaThread::print_thread_state_on(outputStream *st) const {
1466 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1467 }
1468
1469 // Called by Threads::print() for VM_PrintThreads operation
1470 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1471 st->print_raw("\"");
1472 st->print_raw(name());
1473 st->print_raw("\" ");
1474 oop thread_oop = threadObj();
1475 if (thread_oop != nullptr) {
1476 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1477 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1478 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1479 }
1480 Thread::print_on(st, print_extended_info);
1481 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1482 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1483 if (thread_oop != nullptr) {
1484 if (is_vthread_mounted()) {
1485 oop vt = vthread();
1486 assert(vt != nullptr, "");
1487 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1488 } else {
1489 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1490 }
1491 }
1492 #ifndef PRODUCT
1493 _safepoint_state->print_on(st);
1494 #endif // PRODUCT
1495 if (is_Compiler_thread()) {
1496 CompileTask *task = ((CompilerThread*)this)->task();
1497 if (task != nullptr) {
1498 st->print(" Compiling: ");
1499 task->print(st, nullptr, true, false);
1500 } else {
1501 st->print(" No compile task");
1502 }
1503 st->cr();
1504 }
1505 }
1506
1507 void JavaThread::print() const { print_on(tty); }
1508
1509 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1510 st->print("%s", get_thread_name_string(buf, buflen));
1511 }
1512
1513 // Called by fatal error handler. The difference between this and
1514 // JavaThread::print() is that we can't grab lock or allocate memory.
1515 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1516 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1517 Thread* current = Thread::current_or_null_safe();
1518 assert(current != nullptr, "cannot be called by a detached thread");
1519 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1520 // Only access threadObj() if current thread is not a JavaThread
1521 // or if it is a JavaThread that can safely access oops.
1522 oop thread_obj = threadObj();
1523 if (thread_obj != nullptr) {
1524 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
1525 }
1526 }
1527 st->print(" [");
1528 st->print("%s", _get_thread_state_name(_thread_state));
1529 if (osthread()) {
1530 st->print(", id=%d", osthread()->thread_id());
1531 }
1532 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
1533 p2i(stack_end()), p2i(stack_base()));
1534 st->print("]");
1535
1536 ThreadsSMRSupport::print_info_on(this, st);
1537 return;
1538 }
1539
1540
1541 // Verification
1542
1543 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1544 // ignore if there is no stack
1545 if (!has_last_Java_frame()) return;
1546 // traverse the stack frames. Starts from top frame.
1547 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1548 frame* fr = fst.current();
1549 f(fr, fst.register_map());
1550 }
1551 }
1552
1553 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1554
1555 void JavaThread::verify() {
1556 // Verify oops in the thread.
1557 oops_do(&VerifyOopClosure::verify_oop, nullptr);
1558
1559 // Verify the stack frames.
1560 frames_do(frame_verify);
1561 }
1562
1563 // CR 6300358 (sub-CR 2137150)
1564 // Most callers of this method assume that it can't return null but a
1565 // thread may not have a name whilst it is in the process of attaching to
1566 // the VM - see CR 6412693, and there are places where a JavaThread can be
1567 // seen prior to having its threadObj set (e.g., JNI attaching threads and
1568 // if vm exit occurs during initialization). These cases can all be accounted
1569 // for such that this method never returns null.
1570 const char* JavaThread::name() const {
1571 if (Thread::is_JavaThread_protected(/* target */ this)) {
1572 // The target JavaThread is protected so get_thread_name_string() is safe:
1573 return get_thread_name_string();
1574 }
1575
1576 // The target JavaThread is not protected so we return the default:
1577 return Thread::name();
1578 }
1579
1580 // Returns a non-null representation of this thread's name, or a suitable
1581 // descriptive string if there is no set name.
1582 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1583 const char* name_str;
1584 #ifdef ASSERT
1585 Thread* current = Thread::current_or_null_safe();
1586 assert(current != nullptr, "cannot be called by a detached thread");
1587 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1588 // Only access threadObj() if current thread is not a JavaThread
1589 // or if it is a JavaThread that can safely access oops.
1590 #endif
1591 oop thread_obj = threadObj();
1592 if (thread_obj != nullptr) {
1593 oop name = java_lang_Thread::name(thread_obj);
1594 if (name != nullptr) {
1595 if (buf == nullptr) {
1596 name_str = java_lang_String::as_utf8_string(name);
1597 } else {
1598 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1599 }
1600 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1601 name_str = "<no-name - thread is attaching>";
1602 } else {
1603 name_str = "<un-named>";
1604 }
1605 } else {
1606 name_str = Thread::name();
1607 }
1608 #ifdef ASSERT
1609 } else {
1610 // Current JavaThread has exited...
1611 if (current == this) {
1612 // ... and is asking about itself:
1613 name_str = "<no-name - current JavaThread has exited>";
1614 } else {
1615 // ... and it can't safely determine this JavaThread's name so
1616 // use the default thread name.
1617 name_str = Thread::name();
1618 }
1619 }
1620 #endif
1621 assert(name_str != nullptr, "unexpected null thread name");
1622 return name_str;
1623 }
1624
1625 // Helper to extract the name from the thread oop for logging.
1626 const char* JavaThread::name_for(oop thread_obj) {
1627 assert(thread_obj != nullptr, "precondition");
1628 oop name = java_lang_Thread::name(thread_obj);
1629 const char* name_str;
1630 if (name != nullptr) {
1631 name_str = java_lang_String::as_utf8_string(name);
1632 } else {
1633 name_str = "<un-named>";
1634 }
1635 return name_str;
1636 }
1637
1638 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1639
1640 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1641 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1642 // Link Java Thread object <-> C++ Thread
1643
1644 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1645 // and put it into a new Handle. The Handle "thread_oop" can then
1646 // be used to pass the C++ thread object to other methods.
1647
1648 // Set the Java level thread object (jthread) field of the
1649 // new thread (a JavaThread *) to C++ thread object using the
1650 // "thread_oop" handle.
1651
1652 // Set the thread field (a JavaThread *) of the
1653 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1654
1655 Handle thread_oop(Thread::current(),
1656 JNIHandles::resolve_non_null(jni_thread));
1657 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1658 "must be initialized");
1659 set_threadOopHandles(thread_oop());
1660 java_lang_Thread::set_thread(thread_oop(), this);
1661
1662 if (prio == NoPriority) {
1663 prio = java_lang_Thread::priority(thread_oop());
1664 assert(prio != NoPriority, "A valid priority should be present");
1665 }
1666
1667 // Push the Java priority down to the native thread; needs Threads_lock
1668 Thread::set_priority(this, prio);
1669
1670 // Add the new thread to the Threads list and set it in motion.
1671 // We must have threads lock in order to call Threads::add.
1672 // It is crucial that we do not block before the thread is
1673 // added to the Threads list for if a GC happens, then the java_thread oop
1674 // will not be visited by GC.
1675 Threads::add(this);
1676 }
1677
1678 oop JavaThread::current_park_blocker() {
1679 // Support for JSR-166 locks
1680 oop thread_oop = threadObj();
1681 if (thread_oop != nullptr) {
1682 return java_lang_Thread::park_blocker(thread_oop);
1683 }
1684 return nullptr;
1685 }
1686
1687 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1688 // This is the external format, selecting the platform or vthread
1689 // as applicable, and allowing for a native-only stack.
1690 void JavaThread::print_jni_stack() {
1691 assert(this == JavaThread::current(), "Can't print stack of other threads");
1692 if (!has_last_Java_frame()) {
1693 ResourceMark rm(this);
1694 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
1695 if (buf == nullptr) {
1696 tty->print_cr("Unable to print native stack - out of memory");
1697 return;
1698 }
1699 frame f = os::current_frame();
1700 VMError::print_native_stack(tty, f, this, true /*print_source_info */,
1701 -1 /* max stack */, buf, O_BUFLEN);
1702 } else {
1703 print_active_stack_on(tty);
1704 }
1705 }
1706
1707 void JavaThread::print_stack_on(outputStream* st) {
1708 if (!has_last_Java_frame()) return;
1709
1710 Thread* current_thread = Thread::current();
1711 ResourceMark rm(current_thread);
1712 HandleMark hm(current_thread);
1713
1714 RegisterMap reg_map(this,
1715 RegisterMap::UpdateMap::include,
1716 RegisterMap::ProcessFrames::include,
1717 RegisterMap::WalkContinuation::skip);
1718 vframe* start_vf = platform_thread_last_java_vframe(®_map);
1719 int count = 0;
1720 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1721 if (f->is_java_frame()) {
1722 javaVFrame* jvf = javaVFrame::cast(f);
1723 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1724
1725 // Print out lock information
1726 if (JavaMonitorsInStackTrace) {
1727 jvf->print_lock_info_on(st, count);
1728 }
1729 } else {
1730 // Ignore non-Java frames
1731 }
1732
1733 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1734 count++;
1735 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1736 }
1737 }
1738
1739 void JavaThread::print_vthread_stack_on(outputStream* st) {
1740 assert(is_vthread_mounted(), "Caller should have checked this");
1741 assert(has_last_Java_frame(), "must be");
1742
1743 Thread* current_thread = Thread::current();
1744 ResourceMark rm(current_thread);
1745 HandleMark hm(current_thread);
1746
1747 RegisterMap reg_map(this,
1748 RegisterMap::UpdateMap::include,
1749 RegisterMap::ProcessFrames::include,
1750 RegisterMap::WalkContinuation::include);
1751 ContinuationEntry* cont_entry = last_continuation();
1752 vframe* start_vf = last_java_vframe(®_map);
1753 int count = 0;
1754 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1755 // Watch for end of vthread stack
1756 if (Continuation::is_continuation_enterSpecial(f->fr())) {
1757 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), "");
1758 if (cont_entry->is_virtual_thread()) {
1759 break;
1760 }
1761 cont_entry = cont_entry->parent();
1762 }
1763 if (f->is_java_frame()) {
1764 javaVFrame* jvf = javaVFrame::cast(f);
1765 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1766
1767 // Print out lock information
1768 if (JavaMonitorsInStackTrace) {
1769 jvf->print_lock_info_on(st, count);
1770 }
1771 } else {
1772 // Ignore non-Java frames
1773 }
1774
1775 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1776 count++;
1777 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1778 }
1779 }
1780
1781 void JavaThread::print_active_stack_on(outputStream* st) {
1782 if (is_vthread_mounted()) {
1783 print_vthread_stack_on(st);
1784 } else {
1785 print_stack_on(st);
1786 }
1787 }
1788
1789 #if INCLUDE_JVMTI
1790 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1791 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1792 set_jvmti_vthread(thread_oop);
1793
1794 // unbind current JvmtiThreadState from JavaThread
1795 JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1796
1797 // bind new JvmtiThreadState to JavaThread
1798 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1799
1800 return jvmti_thread_state();
1801 }
1802 #endif
1803
1804 // JVMTI PopFrame support
1805 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1806 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments");
1807 if (in_bytes(size_in_bytes) != 0) {
1808 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1809 _popframe_preserved_args_size = in_bytes(size_in_bytes);
1810 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1811 }
1812 }
1813
1814 void* JavaThread::popframe_preserved_args() {
1815 return _popframe_preserved_args;
1816 }
1817
1818 ByteSize JavaThread::popframe_preserved_args_size() {
1819 return in_ByteSize(_popframe_preserved_args_size);
1820 }
1821
1822 WordSize JavaThread::popframe_preserved_args_size_in_words() {
1823 int sz = in_bytes(popframe_preserved_args_size());
1824 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1825 return in_WordSize(sz / wordSize);
1826 }
1827
1828 void JavaThread::popframe_free_preserved_args() {
1829 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice");
1830 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1831 _popframe_preserved_args = nullptr;
1832 _popframe_preserved_args_size = 0;
1833 }
1834
1835 #ifndef PRODUCT
1836
1837 void JavaThread::trace_frames() {
1838 tty->print_cr("[Describe stack]");
1839 int frame_no = 1;
1840 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1841 tty->print(" %d. ", frame_no++);
1842 fst.current()->print_value_on(tty, this);
1843 tty->cr();
1844 }
1845 }
1846
1847 class PrintAndVerifyOopClosure: public OopClosure {
1848 protected:
1849 template <class T> inline void do_oop_work(T* p) {
1850 oop obj = RawAccess<>::oop_load(p);
1851 if (obj == nullptr) return;
1852 tty->print(INTPTR_FORMAT ": ", p2i(p));
1853 if (oopDesc::is_oop_or_null(obj)) {
1854 if (obj->is_objArray()) {
1855 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1856 } else {
1857 obj->print();
1858 }
1859 } else {
1860 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1861 }
1862 tty->cr();
1863 }
1864 public:
1865 virtual void do_oop(oop* p) { do_oop_work(p); }
1866 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1867 };
1868
1869 #ifdef ASSERT
1870 // Print or validate the layout of stack frames
1871 void JavaThread::print_frame_layout(int depth, bool validate_only) {
1872 ResourceMark rm;
1873 PreserveExceptionMark pm(this);
1874 FrameValues values;
1875 int frame_no = 0;
1876 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1877 fst.current()->describe(values, ++frame_no, fst.register_map());
1878 if (depth == frame_no) break;
1879 }
1880 Continuation::describe(values);
1881 if (validate_only) {
1882 values.validate();
1883 } else {
1884 tty->print_cr("[Describe stack layout]");
1885 values.print(this);
1886 }
1887 }
1888 #endif
1889
1890 void JavaThread::trace_stack_from(vframe* start_vf) {
1891 ResourceMark rm;
1892 int vframe_no = 1;
1893 for (vframe* f = start_vf; f; f = f->sender()) {
1894 if (f->is_java_frame()) {
1895 javaVFrame::cast(f)->print_activation(vframe_no++);
1896 } else {
1897 f->print();
1898 }
1899 if (vframe_no > StackPrintLimit) {
1900 tty->print_cr("...<more frames>...");
1901 return;
1902 }
1903 }
1904 }
1905
1906
1907 void JavaThread::trace_stack() {
1908 if (!has_last_Java_frame()) return;
1909 Thread* current_thread = Thread::current();
1910 ResourceMark rm(current_thread);
1911 HandleMark hm(current_thread);
1912 RegisterMap reg_map(this,
1913 RegisterMap::UpdateMap::include,
1914 RegisterMap::ProcessFrames::include,
1915 RegisterMap::WalkContinuation::skip);
1916 trace_stack_from(last_java_vframe(®_map));
1917 }
1918
1919
1920 #endif // PRODUCT
1921
1922 void JavaThread::inc_held_monitor_count(int i, bool jni) {
1923 #ifdef SUPPORT_MONITOR_COUNT
1924 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count);
1925 _held_monitor_count += i;
1926 if (jni) {
1927 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count);
1928 _jni_monitor_count += i;
1929 }
1930 #endif
1931 }
1932
1933 void JavaThread::dec_held_monitor_count(int i, bool jni) {
1934 #ifdef SUPPORT_MONITOR_COUNT
1935 _held_monitor_count -= i;
1936 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count);
1937 if (jni) {
1938 _jni_monitor_count -= i;
1939 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count);
1940 }
1941 #endif
1942 }
1943
1944 frame JavaThread::vthread_last_frame() {
1945 assert (is_vthread_mounted(), "Virtual thread not mounted");
1946 return last_frame();
1947 }
1948
1949 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
1950 const ContinuationEntry* entry = vthread_continuation();
1951 guarantee (entry != nullptr, "Not a carrier thread");
1952 frame f = entry->to_frame();
1953 if (reg_map->process_frames()) {
1954 entry->flush_stack_processing(this);
1955 }
1956 entry->update_register_map(reg_map);
1957 return f.sender(reg_map);
1958 }
1959
1960 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
1961 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
1962 }
1963
1964 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
1965 assert(reg_map != nullptr, "a map must be given");
1966 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
1967 if (vf->is_java_frame()) return javaVFrame::cast(vf);
1968 }
1969 return nullptr;
1970 }
1971
1972 Klass* JavaThread::security_get_caller_class(int depth) {
1973 ResetNoHandleMark rnhm;
1974 HandleMark hm(Thread::current());
1975
1976 vframeStream vfst(this);
1977 vfst.security_get_caller_frame(depth);
1978 if (!vfst.at_end()) {
1979 return vfst.method()->method_holder();
1980 }
1981 return nullptr;
1982 }
1983
1984 // java.lang.Thread.sleep support
1985 // Returns true if sleep time elapsed as expected, and false
1986 // if the thread was interrupted.
1987 bool JavaThread::sleep(jlong millis) {
1988 assert(this == Thread::current(), "thread consistency check");
1989
1990 ParkEvent * const slp = this->_SleepEvent;
1991 // Because there can be races with thread interruption sending an unpark()
1992 // to the event, we explicitly reset it here to avoid an immediate return.
1993 // The actual interrupt state will be checked before we park().
1994 slp->reset();
1995 // Thread interruption establishes a happens-before ordering in the
1996 // Java Memory Model, so we need to ensure we synchronize with the
1997 // interrupt state.
1998 OrderAccess::fence();
1999
2000 jlong prevtime = os::javaTimeNanos();
2001
2002 for (;;) {
2003 // interruption has precedence over timing out
2004 if (this->is_interrupted(true)) {
2005 return false;
2006 }
2007
2008 if (millis <= 0) {
2009 return true;
2010 }
2011
2012 {
2013 ThreadBlockInVM tbivm(this);
2014 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2015 slp->park(millis);
2016 }
2017
2018 // Update elapsed time tracking
2019 jlong newtime = os::javaTimeNanos();
2020 if (newtime - prevtime < 0) {
2021 // time moving backwards, should only happen if no monotonic clock
2022 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2023 assert(false,
2024 "unexpected time moving backwards detected in JavaThread::sleep()");
2025 } else {
2026 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2027 }
2028 prevtime = newtime;
2029 }
2030 }
2031
2032 // Last thread running calls java.lang.Shutdown.shutdown()
2033 void JavaThread::invoke_shutdown_hooks() {
2034 HandleMark hm(this);
2035
2036 // We could get here with a pending exception, if so clear it now.
2037 if (this->has_pending_exception()) {
2038 this->clear_pending_exception();
2039 }
2040
2041 EXCEPTION_MARK;
2042 Klass* shutdown_klass =
2043 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
2044 THREAD);
2045 if (shutdown_klass != nullptr) {
2046 // SystemDictionary::resolve_or_null will return null if there was
2047 // an exception. If we cannot load the Shutdown class, just don't
2048 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
2049 // won't be run. Note that if a shutdown hook was registered,
2050 // the Shutdown class would have already been loaded
2051 // (Runtime.addShutdownHook will load it).
2052 JavaValue result(T_VOID);
2053 JavaCalls::call_static(&result,
2054 shutdown_klass,
2055 vmSymbols::shutdown_name(),
2056 vmSymbols::void_method_signature(),
2057 THREAD);
2058 }
2059 CLEAR_PENDING_EXCEPTION;
2060 }
2061
2062 #ifndef PRODUCT
2063 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
2064 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
2065 }
2066 #endif
2067
2068 // Helper function to create the java.lang.Thread object for a
2069 // VM-internal thread. The thread will have the given name, and be
2070 // a member of the "system" ThreadGroup.
2071 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) {
2072 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2073
2074 // Initialize thread_oop to put it into the system threadGroup.
2075 // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2076 Handle thread_group(THREAD, Universe::system_thread_group());
2077 Handle thread_oop =
2078 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2079 vmSymbols::threadgroup_string_void_signature(),
2080 thread_group,
2081 string,
2082 CHECK_NH);
2083
2084 return thread_oop;
2085 }
2086
2087 // Starts the target JavaThread as a daemon of the given priority, and
2088 // bound to the given java.lang.Thread instance.
2089 // The Threads_lock is held for the duration.
2090 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2091 Handle thread_oop, ThreadPriority prio) {
2092
2093 assert(target->osthread() != nullptr, "target thread is not properly initialized");
2094
2095 MutexLocker mu(current, Threads_lock);
2096
2097 // Initialize the fields of the thread_oop first.
2098
2099 java_lang_Thread::set_thread(thread_oop(), target); // isAlive == true now
2100
2101 if (prio != NoPriority) {
2102 java_lang_Thread::set_priority(thread_oop(), prio);
2103 // Note: we don't call os::set_priority here. Possibly we should,
2104 // else all threads should call it themselves when they first run.
2105 }
2106
2107 java_lang_Thread::set_daemon(thread_oop());
2108
2109 // Now bind the thread_oop to the target JavaThread.
2110 target->set_threadOopHandles(thread_oop());
2111
2112 Threads::add(target); // target is now visible for safepoint/handshake
2113 Thread::start(target);
2114 }
2115
2116 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2117 // At this point it may be possible that no osthread was created for the
2118 // JavaThread due to lack of resources. However, since this must work
2119 // for critical system threads just check and abort if this fails.
2120 if (thread->osthread() == nullptr) {
2121 // This isn't really an OOM condition, but historically this is what
2122 // we report.
2123 vm_exit_during_initialization("java.lang.OutOfMemoryError",
2124 os::native_thread_creation_failed_msg());
2125 }
2126 }
2127
2128 void JavaThread::pretouch_stack() {
2129 // Given an established java thread stack with usable area followed by
2130 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging
2131 // from the current frame down to the start of the shadow zone.
2132 const address end = _stack_overflow_state.shadow_zone_safe_limit();
2133 if (is_in_full_stack(end)) {
2134 char* p1 = (char*) alloca(1);
2135 address here = (address) &p1;
2136 if (is_in_full_stack(here) && here > end) {
2137 size_t to_alloc = here - end;
2138 char* p2 = (char*) alloca(to_alloc);
2139 log_trace(os, thread)("Pretouching thread stack from " PTR_FORMAT " to " PTR_FORMAT ".",
2140 p2i(p2), p2i(end));
2141 os::pretouch_memory(p2, p2 + to_alloc,
2142 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096));
2143 }
2144 }
2145 }
2146
2147 // Deferred OopHandle release support.
2148
2149 class OopHandleList : public CHeapObj<mtInternal> {
2150 static const int _count = 4;
2151 OopHandle _handles[_count];
2152 OopHandleList* _next;
2153 int _index;
2154 public:
2155 OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2156 void add(OopHandle h) {
2157 assert(_index < _count, "too many additions");
2158 _handles[_index++] = h;
2159 }
2160 ~OopHandleList() {
2161 assert(_index == _count, "usage error");
2162 for (int i = 0; i < _index; i++) {
2163 _handles[i].release(JavaThread::thread_oop_storage());
2164 }
2165 }
2166 OopHandleList* next() const { return _next; }
2167 };
2168
2169 OopHandleList* JavaThread::_oop_handle_list = nullptr;
2170
2171 // Called by the ServiceThread to do the work of releasing
2172 // the OopHandles.
2173 void JavaThread::release_oop_handles() {
2174 OopHandleList* list;
2175 {
2176 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2177 list = _oop_handle_list;
2178 _oop_handle_list = nullptr;
2179 }
2180 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2181
2182 while (list != nullptr) {
2183 OopHandleList* l = list;
2184 list = l->next();
2185 delete l;
2186 }
2187 }
2188
2189 // Add our OopHandles for later release.
2190 void JavaThread::add_oop_handles_for_release() {
2191 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2192 OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2193 new_head->add(_threadObj);
2194 new_head->add(_vthread);
2195 new_head->add(_jvmti_vthread);
2196 new_head->add(_scopedValueCache);
2197 _oop_handle_list = new_head;
2198 Service_lock->notify_all();
2199 }