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/os.inline.hpp"
77 #include "runtime/osThread.hpp"
78 #include "runtime/safepoint.hpp"
79 #include "runtime/safepointMechanism.inline.hpp"
80 #include "runtime/safepointVerifiers.hpp"
81 #include "runtime/serviceThread.hpp"
82 #include "runtime/stackFrameStream.inline.hpp"
83 #include "runtime/stackWatermarkSet.hpp"
84 #include "runtime/synchronizer.hpp"
85 #include "runtime/threadCritical.hpp"
86 #include "runtime/threadSMR.inline.hpp"
87 #include "runtime/threadStatisticalInfo.hpp"
88 #include "runtime/threadWXSetters.inline.hpp"
89 #include "runtime/timer.hpp"
90 #include "runtime/timerTrace.hpp"
91 #include "runtime/vframe.inline.hpp"
92 #include "runtime/vframeArray.hpp"
93 #include "runtime/vframe_hp.hpp"
94 #include "runtime/vmThread.hpp"
95 #include "runtime/vmOperations.hpp"
96 #include "services/threadService.hpp"
97 #include "utilities/copy.hpp"
98 #include "utilities/defaultStream.hpp"
99 #include "utilities/dtrace.hpp"
100 #include "utilities/events.hpp"
101 #include "utilities/macros.hpp"
102 #include "utilities/preserveException.hpp"
103 #include "utilities/spinYield.hpp"
104 #include "utilities/vmError.hpp"
105 #if INCLUDE_JVMCI
106 #include "jvmci/jvmci.hpp"
107 #include "jvmci/jvmciEnv.hpp"
108 #endif
109 #if INCLUDE_JFR
110 #include "jfr/jfr.hpp"
111 #endif
112
113 // Set by os layer.
114 size_t JavaThread::_stack_size_at_create = 0;
115
116 #ifdef DTRACE_ENABLED
117
118 // Only bother with this argument setup if dtrace is available
119
120 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
121 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
122
123 #define DTRACE_THREAD_PROBE(probe, javathread) \
124 { \
125 ResourceMark rm(this); \
126 int len = 0; \
127 const char* name = (javathread)->name(); \
128 len = strlen(name); \
129 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
130 (char *) name, len, \
131 java_lang_Thread::thread_id((javathread)->threadObj()), \
132 (uintptr_t) (javathread)->osthread()->thread_id(), \
133 java_lang_Thread::is_daemon((javathread)->threadObj())); \
134 }
135
136 #else // ndef DTRACE_ENABLED
137
138 #define DTRACE_THREAD_PROBE(probe, javathread)
139
140 #endif // ndef DTRACE_ENABLED
141
142 void JavaThread::smr_delete() {
143 if (_on_thread_list) {
144 ThreadsSMRSupport::smr_delete(this);
145 } else {
146 delete this;
147 }
148 }
149
150 // Initialized by VMThread at vm_global_init
151 OopStorage* JavaThread::_thread_oop_storage = nullptr;
152
153 OopStorage* JavaThread::thread_oop_storage() {
154 assert(_thread_oop_storage != nullptr, "not yet initialized");
155 return _thread_oop_storage;
156 }
157
158 void JavaThread::set_threadOopHandles(oop p) {
159 assert(_thread_oop_storage != nullptr, "not yet initialized");
160 _threadObj = OopHandle(_thread_oop_storage, p);
161 _vthread = OopHandle(_thread_oop_storage, p);
162 _jvmti_vthread = OopHandle(_thread_oop_storage, p->is_a(vmClasses::BoundVirtualThread_klass()) ? p : nullptr);
163 _scopedValueCache = OopHandle(_thread_oop_storage, nullptr);
164 }
165
166 oop JavaThread::threadObj() const {
167 // Ideally we would verify the current thread is oop_safe when this is called, but as we can
168 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That
169 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS.
170 // Instead callers must verify oop safe access.
171 return _threadObj.resolve();
172 }
173
174 oop JavaThread::vthread() const {
175 return _vthread.resolve();
176 }
177
178 void JavaThread::set_vthread(oop p) {
179 assert(_thread_oop_storage != nullptr, "not yet initialized");
180 _vthread.replace(p);
181 }
182
183 oop JavaThread::jvmti_vthread() const {
184 return _jvmti_vthread.resolve();
185 }
186
187 void JavaThread::set_jvmti_vthread(oop p) {
188 assert(_thread_oop_storage != nullptr, "not yet initialized");
189 _jvmti_vthread.replace(p);
190 }
191
192 oop JavaThread::scopedValueCache() const {
193 return _scopedValueCache.resolve();
194 }
195
196 void JavaThread::set_scopedValueCache(oop p) {
197 if (_scopedValueCache.ptr_raw() != nullptr) { // i.e. if the OopHandle has been allocated
198 _scopedValueCache.replace(p);
199 } else {
200 assert(p == nullptr, "not yet initialized");
201 }
202 }
203
204 void JavaThread::clear_scopedValueBindings() {
205 set_scopedValueCache(nullptr);
206 oop vthread_oop = vthread();
207 // vthread may be null here if we get a VM error during startup,
208 // before the java.lang.Thread instance has been created.
209 if (vthread_oop != nullptr) {
210 java_lang_Thread::clear_scopedValueBindings(vthread_oop);
211 }
212 }
213
214 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
215 bool daemon, TRAPS) {
216 assert(thread_group.not_null(), "thread group should be specified");
217 assert(threadObj() == nullptr, "should only create Java thread object once");
218
219 InstanceKlass* ik = vmClasses::Thread_klass();
220 assert(ik->is_initialized(), "must be");
221 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
222
223 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
224 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
225 // constructor calls Thread.current(), which must be set here.
226 java_lang_Thread::set_thread(thread_oop(), this);
227 set_threadOopHandles(thread_oop());
228
229 JavaValue result(T_VOID);
230 if (thread_name != nullptr) {
231 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
232 // Thread gets assigned specified name and null target
233 JavaCalls::call_special(&result,
234 thread_oop,
235 ik,
236 vmSymbols::object_initializer_name(),
237 vmSymbols::threadgroup_string_void_signature(),
238 thread_group,
239 name,
240 CHECK);
241 } else {
242 // Thread gets assigned name "Thread-nnn" and null target
243 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
244 JavaCalls::call_special(&result,
245 thread_oop,
246 ik,
247 vmSymbols::object_initializer_name(),
248 vmSymbols::threadgroup_runnable_void_signature(),
249 thread_group,
250 Handle(),
251 CHECK);
252 }
253 os::set_priority(this, NormPriority);
254
255 if (daemon) {
256 java_lang_Thread::set_daemon(thread_oop());
257 }
258 }
259
260 // ======= JavaThread ========
261
262 #if INCLUDE_JVMCI
263
264 jlong* JavaThread::_jvmci_old_thread_counters;
265
266 bool jvmci_counters_include(JavaThread* thread) {
267 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
268 }
269
270 void JavaThread::collect_counters(jlong* array, int length) {
271 assert(length == JVMCICounterSize, "wrong value");
272 for (int i = 0; i < length; i++) {
273 array[i] = _jvmci_old_thread_counters[i];
274 }
275 for (JavaThread* tp : ThreadsListHandle()) {
276 if (jvmci_counters_include(tp)) {
277 for (int i = 0; i < length; i++) {
278 array[i] += tp->_jvmci_counters[i];
279 }
280 }
281 }
282 }
283
284 // Attempt to enlarge the array for per thread counters.
285 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
286 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
287 if (new_counters == nullptr) {
288 return nullptr;
289 }
290 if (old_counters == nullptr) {
291 old_counters = new_counters;
292 memset(old_counters, 0, sizeof(jlong) * new_size);
293 } else {
294 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
295 new_counters[i] = old_counters[i];
296 }
297 if (new_size > current_size) {
298 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
299 }
300 FREE_C_HEAP_ARRAY(jlong, old_counters);
301 }
302 return new_counters;
303 }
304
305 // Attempt to enlarge the array for per thread counters.
306 bool JavaThread::resize_counters(int current_size, int new_size) {
307 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
308 if (new_counters == nullptr) {
309 return false;
310 } else {
311 _jvmci_counters = new_counters;
312 return true;
313 }
314 }
315
316 class VM_JVMCIResizeCounters : public VM_Operation {
317 private:
318 int _new_size;
319 bool _failed;
320
321 public:
322 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
323 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
324 bool allow_nested_vm_operations() const { return true; }
325 void doit() {
326 // Resize the old thread counters array
327 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
328 if (new_counters == nullptr) {
329 _failed = true;
330 return;
331 } else {
332 JavaThread::_jvmci_old_thread_counters = new_counters;
333 }
334
335 // Now resize each threads array
336 for (JavaThread* tp : ThreadsListHandle()) {
337 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
338 _failed = true;
339 break;
340 }
341 }
342 if (!_failed) {
343 JVMCICounterSize = _new_size;
344 }
345 }
346
347 bool failed() { return _failed; }
348 };
349
350 bool JavaThread::resize_all_jvmci_counters(int new_size) {
351 VM_JVMCIResizeCounters op(new_size);
352 VMThread::execute(&op);
353 return !op.failed();
354 }
355
356 #endif // INCLUDE_JVMCI
357
358 #ifdef ASSERT
359 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
360 void JavaThread::check_possible_safepoint() {
361 if (_no_safepoint_count > 0) {
362 print_owned_locks();
363 assert(false, "Possible safepoint reached by thread that does not allow it");
364 }
365 #ifdef CHECK_UNHANDLED_OOPS
366 // Clear unhandled oops in JavaThreads so we get a crash right away.
367 clear_unhandled_oops();
368 #endif // CHECK_UNHANDLED_OOPS
369
370 // Macos/aarch64 should be in the right state for safepoint (e.g.
371 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely
372 // happens in practice, making such issues hard to find and reproduce.
373 #if defined(__APPLE__) && defined(AARCH64)
374 if (AssertWXAtThreadSync) {
375 assert_wx_state(WXWrite);
376 }
377 #endif
378 }
379
380 void JavaThread::check_for_valid_safepoint_state() {
381 // Don't complain if running a debugging command.
382 if (DebuggingContext::is_enabled()) return;
383
384 // Check NoSafepointVerifier, which is implied by locks taken that can be
385 // shared with the VM thread. This makes sure that no locks with allow_vm_block
386 // are held.
387 check_possible_safepoint();
388
389 if (thread_state() != _thread_in_vm) {
390 fatal("LEAF method calling lock?");
391 }
392
393 if (GCALotAtAllSafepoints) {
394 // We could enter a safepoint here and thus have a gc
395 InterfaceSupport::check_gc_alot();
396 }
397 }
398 #endif // ASSERT
399
400 // A JavaThread is a normal Java thread
401
402 JavaThread::JavaThread() :
403 // Initialize fields
404
405 _on_thread_list(false),
406 DEBUG_ONLY(_java_call_counter(0) COMMA)
407 _entry_point(nullptr),
408 _deopt_mark(nullptr),
409 _deopt_nmethod(nullptr),
410 _vframe_array_head(nullptr),
411 _vframe_array_last(nullptr),
412 _jvmti_deferred_updates(nullptr),
413 _callee_target(nullptr),
414 _vm_result(nullptr),
415 _vm_result_2(nullptr),
416
417 _current_pending_monitor(nullptr),
418 _current_pending_monitor_is_from_java(true),
419 _current_waiting_monitor(nullptr),
420 _active_handles(nullptr),
421 _free_handle_block(nullptr),
422 _Stalled(0),
423
424 _monitor_chunks(nullptr),
425
426 _suspend_flags(0),
427
428 _thread_state(_thread_new),
429 _saved_exception_pc(nullptr),
430 #ifdef ASSERT
431 _no_safepoint_count(0),
432 _visited_for_critical_count(false),
433 #endif
434
435 _terminated(_not_terminated),
436 _in_deopt_handler(0),
437 _doing_unsafe_access(false),
438 _do_not_unlock_if_synchronized(false),
439 #if INCLUDE_JVMTI
440 _carrier_thread_suspended(false),
441 _is_in_VTMS_transition(false),
442 _is_in_tmp_VTMS_transition(false),
443 #ifdef ASSERT
444 _is_VTMS_transition_disabler(false),
445 #endif
446 #endif
447 _jni_attach_state(_not_attaching_via_jni),
448 #if INCLUDE_JVMCI
449 _pending_deoptimization(-1),
450 _pending_monitorenter(false),
451 _pending_transfer_to_interpreter(false),
452 _in_retryable_allocation(false),
453 _pending_failed_speculation(0),
454 _jvmci{nullptr},
455 _libjvmci_runtime(nullptr),
456 _jvmci_counters(nullptr),
457 _jvmci_reserved0(0),
458 _jvmci_reserved1(0),
459 _jvmci_reserved_oop0(nullptr),
460 #endif // INCLUDE_JVMCI
461
462 _exception_oop(oop()),
463 _exception_pc(0),
464 _exception_handler_pc(0),
465 _is_method_handle_return(0),
466
467 _jni_active_critical(0),
468 _pending_jni_exception_check_fn(nullptr),
469 _depth_first_number(0),
470
471 // JVMTI PopFrame support
472 _popframe_condition(popframe_inactive),
473 _frames_to_pop_failed_realloc(0),
474
475 _cont_entry(nullptr),
476 _cont_fastpath(0),
477 _cont_fastpath_thread_state(1),
478 _held_monitor_count(0),
479 _jni_monitor_count(0),
480
481 _handshake(this),
482
483 _popframe_preserved_args(nullptr),
484 _popframe_preserved_args_size(0),
485
486 _jvmti_thread_state(nullptr),
487 _interp_only_mode(0),
488 _should_post_on_exceptions_flag(JNI_FALSE),
489 _thread_stat(new ThreadStatistics()),
490
491 _parker(),
492
493 _class_to_be_initialized(nullptr),
494
495 _SleepEvent(ParkEvent::Allocate(this)),
496
497 _lock_stack(this) {
498 set_jni_functions(jni_functions());
499
500 #if INCLUDE_JVMCI
501 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
502 if (JVMCICounterSize > 0) {
503 resize_counters(0, (int) JVMCICounterSize);
504 }
505 #endif // INCLUDE_JVMCI
506
507 // Setup safepoint state info for this thread
508 ThreadSafepointState::create(this);
509
510 SafepointMechanism::initialize_header(this);
511
512 set_requires_cross_modify_fence(false);
513
514 pd_initialize();
515 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
516 }
517
518 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
519 if (is_attaching_via_jni) {
520 _jni_attach_state = _attaching_via_jni;
521 }
522 }
523
524
525 // interrupt support
526
527 void JavaThread::interrupt() {
528 // All callers should have 'this' thread protected by a
529 // ThreadsListHandle so that it cannot terminate and deallocate
530 // itself.
531 debug_only(check_for_dangling_thread_pointer(this);)
532
533 // For Windows _interrupt_event
534 WINDOWS_ONLY(osthread()->set_interrupted(true);)
535
536 // For Thread.sleep
537 _SleepEvent->unpark();
538
539 // For JSR166 LockSupport.park
540 parker()->unpark();
541
542 // For ObjectMonitor and JvmtiRawMonitor
543 _ParkEvent->unpark();
544 }
545
546
547 bool JavaThread::is_interrupted(bool clear_interrupted) {
548 debug_only(check_for_dangling_thread_pointer(this);)
549
550 if (_threadObj.peek() == nullptr) {
551 // If there is no j.l.Thread then it is impossible to have
552 // been interrupted. We can find null during VM initialization
553 // or when a JNI thread is still in the process of attaching.
554 // In such cases this must be the current thread.
555 assert(this == Thread::current(), "invariant");
556 return false;
557 }
558
559 bool interrupted = java_lang_Thread::interrupted(threadObj());
560
561 // NOTE that since there is no "lock" around the interrupt and
562 // is_interrupted operations, there is the possibility that the
563 // interrupted flag will be "false" but that the
564 // low-level events will be in the signaled state. This is
565 // intentional. The effect of this is that Object.wait() and
566 // LockSupport.park() will appear to have a spurious wakeup, which
567 // is allowed and not harmful, and the possibility is so rare that
568 // it is not worth the added complexity to add yet another lock.
569 // For the sleep event an explicit reset is performed on entry
570 // to JavaThread::sleep, so there is no early return. It has also been
571 // recommended not to put the interrupted flag into the "event"
572 // structure because it hides the issue.
573 // Also, because there is no lock, we must only clear the interrupt
574 // state if we are going to report that we were interrupted; otherwise
575 // an interrupt that happens just after we read the field would be lost.
576 if (interrupted && clear_interrupted) {
577 assert(this == Thread::current(), "only the current thread can clear");
578 java_lang_Thread::set_interrupted(threadObj(), false);
579 WINDOWS_ONLY(osthread()->set_interrupted(false);)
580 }
581
582 return interrupted;
583 }
584
585 void JavaThread::block_if_vm_exited() {
586 if (_terminated == _vm_exited) {
587 // _vm_exited is set at safepoint, and Threads_lock is never released
588 // so we will block here forever.
589 // Here we can be doing a jump from a safe state to an unsafe state without
590 // proper transition, but it happens after the final safepoint has begun so
591 // this jump won't cause any safepoint problems.
592 set_thread_state(_thread_in_vm);
593 Threads_lock->lock();
594 ShouldNotReachHere();
595 }
596 }
597
598 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
599 _jni_attach_state = _not_attaching_via_jni;
600 set_entry_point(entry_point);
601 // Create the native thread itself.
602 // %note runtime_23
603 os::ThreadType thr_type = os::java_thread;
604 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
605 os::java_thread;
606 os::create_thread(this, thr_type, stack_sz);
607 // The _osthread may be null here because we ran out of memory (too many threads active).
608 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
609 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
610 // the exception consists of creating the exception object & initializing it, initialization
611 // will leave the VM via a JavaCall and then all locks must be unlocked).
612 //
613 // The thread is still suspended when we reach here. Thread must be explicit started
614 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
615 // by calling Threads:add. The reason why this is not done here, is because the thread
616 // object must be fully initialized (take a look at JVM_Start)
617 }
618
619 JavaThread::~JavaThread() {
620
621 // Enqueue OopHandles for release by the service thread.
622 add_oop_handles_for_release();
623
624 // Return the sleep event to the free list
625 ParkEvent::Release(_SleepEvent);
626 _SleepEvent = nullptr;
627
628 // Free any remaining previous UnrollBlock
629 vframeArray* old_array = vframe_array_last();
630
631 if (old_array != nullptr) {
632 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
633 old_array->set_unroll_block(nullptr);
634 delete old_info;
635 delete old_array;
636 }
637
638 JvmtiDeferredUpdates* updates = deferred_updates();
639 if (updates != nullptr) {
640 // This can only happen if thread is destroyed before deoptimization occurs.
641 assert(updates->count() > 0, "Updates holder not deleted");
642 // free deferred updates.
643 delete updates;
644 set_deferred_updates(nullptr);
645 }
646
647 // All Java related clean up happens in exit
648 ThreadSafepointState::destroy(this);
649 if (_thread_stat != nullptr) delete _thread_stat;
650
651 #if INCLUDE_JVMCI
652 if (JVMCICounterSize > 0) {
653 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
654 }
655 #endif // INCLUDE_JVMCI
656 }
657
658
659 // First JavaThread specific code executed by a new Java thread.
660 void JavaThread::pre_run() {
661 // empty - see comments in run()
662 }
663
664 // The main routine called by a new Java thread. This isn't overridden
665 // by subclasses, instead different subclasses define a different "entry_point"
666 // which defines the actual logic for that kind of thread.
667 void JavaThread::run() {
668 // initialize thread-local alloc buffer related fields
669 initialize_tlab();
670
671 _stack_overflow_state.create_stack_guard_pages();
672
673 cache_global_variables();
674
675 // Thread is now sufficiently initialized to be handled by the safepoint code as being
676 // in the VM. Change thread state from _thread_new to _thread_in_vm
677 assert(this->thread_state() == _thread_new, "wrong thread state");
678 set_thread_state(_thread_in_vm);
679
680 // Before a thread is on the threads list it is always safe, so after leaving the
681 // _thread_new we should emit a instruction barrier. The distance to modified code
682 // from here is probably far enough, but this is consistent and safe.
683 OrderAccess::cross_modify_fence();
684
685 assert(JavaThread::current() == this, "sanity check");
686 assert(!Thread::current()->owns_locks(), "sanity check");
687
688 DTRACE_THREAD_PROBE(start, this);
689
690 // This operation might block. We call that after all safepoint checks for a new thread has
691 // been completed.
692 set_active_handles(JNIHandleBlock::allocate_block());
693
694 if (JvmtiExport::should_post_thread_life()) {
695 JvmtiExport::post_thread_start(this);
696
697 }
698
699 if (AlwaysPreTouchStacks) {
700 pretouch_stack();
701 }
702
703 // We call another function to do the rest so we are sure that the stack addresses used
704 // from there will be lower than the stack base just computed.
705 thread_main_inner();
706 }
707
708 void JavaThread::thread_main_inner() {
709 assert(JavaThread::current() == this, "sanity check");
710 assert(_threadObj.peek() != nullptr, "just checking");
711
712 // Execute thread entry point unless this thread has a pending exception.
713 // Note: Due to JVMTI StopThread we can have pending exceptions already!
714 if (!this->has_pending_exception()) {
715 {
716 ResourceMark rm(this);
717 this->set_native_thread_name(this->name());
718 }
719 HandleMark hm(this);
720 this->entry_point()(this, this);
721 }
722
723 DTRACE_THREAD_PROBE(stop, this);
724
725 // Cleanup is handled in post_run()
726 }
727
728 // Shared teardown for all JavaThreads
729 void JavaThread::post_run() {
730 this->exit(false);
731 this->unregister_thread_stack_with_NMT();
732 // Defer deletion to here to ensure 'this' is still referenceable in call_run
733 // for any shared tear-down.
734 this->smr_delete();
735 }
736
737 static void ensure_join(JavaThread* thread) {
738 // We do not need to grab the Threads_lock, since we are operating on ourself.
739 Handle threadObj(thread, thread->threadObj());
740 assert(threadObj.not_null(), "java thread object must exist");
741 ObjectLocker lock(threadObj, thread);
742 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
743 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
744 // Clear the native thread instance - this makes isAlive return false and allows the join()
745 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model
746 // requirements.
747 java_lang_Thread::release_set_thread(threadObj(), nullptr);
748 lock.notify_all(thread);
749 // Ignore pending exception, since we are exiting anyway
750 thread->clear_pending_exception();
751 }
752
753 static bool is_daemon(oop threadObj) {
754 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj));
755 }
756
757 // For any new cleanup additions, please check to see if they need to be applied to
758 // cleanup_failed_attach_current_thread as well.
759 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
760 assert(this == JavaThread::current(), "thread consistency check");
761 assert(!is_exiting(), "should not be exiting or terminated already");
762
763 elapsedTimer _timer_exit_phase1;
764 elapsedTimer _timer_exit_phase2;
765 elapsedTimer _timer_exit_phase3;
766 elapsedTimer _timer_exit_phase4;
767
768 if (log_is_enabled(Debug, os, thread, timer)) {
769 _timer_exit_phase1.start();
770 }
771
772 HandleMark hm(this);
773 Handle uncaught_exception(this, this->pending_exception());
774 this->clear_pending_exception();
775 Handle threadObj(this, this->threadObj());
776 assert(threadObj.not_null(), "Java thread object should be created");
777
778 if (!destroy_vm) {
779 if (uncaught_exception.not_null()) {
780 EXCEPTION_MARK;
781 // Call method Thread.dispatchUncaughtException().
782 Klass* thread_klass = vmClasses::Thread_klass();
783 JavaValue result(T_VOID);
784 JavaCalls::call_virtual(&result,
785 threadObj, thread_klass,
786 vmSymbols::dispatchUncaughtException_name(),
787 vmSymbols::throwable_void_signature(),
788 uncaught_exception,
789 THREAD);
790 if (HAS_PENDING_EXCEPTION) {
791 ResourceMark rm(this);
792 jio_fprintf(defaultStream::error_stream(),
793 "\nException: %s thrown from the UncaughtExceptionHandler"
794 " in thread \"%s\"\n",
795 pending_exception()->klass()->external_name(),
796 name());
797 CLEAR_PENDING_EXCEPTION;
798 }
799 }
800
801 if (!is_Compiler_thread()) {
802 // We have finished executing user-defined Java code and now have to do the
803 // implementation specific clean-up by calling Thread.exit(). We prevent any
804 // asynchronous exceptions from being delivered while in Thread.exit()
805 // to ensure the clean-up is not corrupted.
806 NoAsyncExceptionDeliveryMark _no_async(this);
807
808 EXCEPTION_MARK;
809 JavaValue result(T_VOID);
810 Klass* thread_klass = vmClasses::Thread_klass();
811 JavaCalls::call_virtual(&result,
812 threadObj, thread_klass,
813 vmSymbols::exit_method_name(),
814 vmSymbols::void_method_signature(),
815 THREAD);
816 CLEAR_PENDING_EXCEPTION;
817 }
818
819 // notify JVMTI
820 if (JvmtiExport::should_post_thread_life()) {
821 JvmtiExport::post_thread_end(this);
822 }
823 } else {
824 // before_exit() has already posted JVMTI THREAD_END events
825 }
826
827 // Cleanup any pending async exception now since we cannot access oops after
828 // BarrierSet::barrier_set()->on_thread_detach() has been executed.
829 if (has_async_exception_condition()) {
830 handshake_state()->clean_async_exception_operation();
831 }
832
833 // The careful dance between thread suspension and exit is handled here.
834 // Since we are in thread_in_vm state and suspension is done with handshakes,
835 // we can just put in the exiting state and it will be correctly handled.
836 // Also, no more async exceptions will be added to the queue after this point.
837 set_terminated(_thread_exiting);
838 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
839
840 if (log_is_enabled(Debug, os, thread, timer)) {
841 _timer_exit_phase1.stop();
842 _timer_exit_phase2.start();
843 }
844
845 // Capture daemon status before the thread is marked as terminated.
846 bool daemon = is_daemon(threadObj());
847
848 // Notify waiters on thread object. This has to be done after exit() is called
849 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
850 // group should have the destroyed bit set before waiters are notified).
851 ensure_join(this);
852 assert(!this->has_pending_exception(), "ensure_join should have cleared");
853
854 if (log_is_enabled(Debug, os, thread, timer)) {
855 _timer_exit_phase2.stop();
856 _timer_exit_phase3.start();
857 }
858 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
859 // held by this thread must be released. The spec does not distinguish
860 // between JNI-acquired and regular Java monitors. We can only see
861 // regular Java monitors here if monitor enter-exit matching is broken.
862 //
863 // ensure_join() ignores IllegalThreadStateExceptions, and so does
864 // ObjectSynchronizer::release_monitors_owned_by_thread().
865 if (exit_type == jni_detach) {
866 // Sanity check even though JNI DetachCurrentThread() would have
867 // returned JNI_ERR if there was a Java frame. JavaThread exit
868 // should be done executing Java code by the time we get here.
869 assert(!this->has_last_Java_frame(),
870 "should not have a Java frame when detaching or exiting");
871 ObjectSynchronizer::release_monitors_owned_by_thread(this);
872 assert(!this->has_pending_exception(), "release_monitors should have cleared");
873 }
874
875 // Since above code may not release JNI monitors and if someone forgot to do an
876 // JNI monitorexit, held count should be equal jni count.
877 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach).
878 assert(held_monitor_count() == jni_monitor_count(),
879 "held monitor count should be equal to jni: " INTX_FORMAT " != " INTX_FORMAT,
880 held_monitor_count(), jni_monitor_count());
881 if (CheckJNICalls && jni_monitor_count() > 0) {
882 // We would like a fatal here, but due to we never checked this before there
883 // is a lot of tests which breaks, even with an error log.
884 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.",
885 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id());
886 }
887
888 // These things needs to be done while we are still a Java Thread. Make sure that thread
889 // is in a consistent state, in case GC happens
890 JFR_ONLY(Jfr::on_thread_exit(this);)
891
892 if (active_handles() != nullptr) {
893 JNIHandleBlock* block = active_handles();
894 set_active_handles(nullptr);
895 JNIHandleBlock::release_block(block);
896 }
897
898 if (free_handle_block() != nullptr) {
899 JNIHandleBlock* block = free_handle_block();
900 set_free_handle_block(nullptr);
901 JNIHandleBlock::release_block(block);
902 }
903
904 // These have to be removed while this is still a valid thread.
905 _stack_overflow_state.remove_stack_guard_pages();
906
907 if (UseTLAB) {
908 tlab().retire();
909 }
910
911 if (JvmtiEnv::environments_might_exist()) {
912 JvmtiExport::cleanup_thread(this);
913 }
914
915 // We need to cache the thread name for logging purposes below as once
916 // we have called on_thread_detach this thread must not access any oops.
917 char* thread_name = nullptr;
918 if (log_is_enabled(Debug, os, thread, timer)) {
919 ResourceMark rm(this);
920 thread_name = os::strdup(name());
921 }
922
923 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
924 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
925 os::current_thread_id());
926
927 if (log_is_enabled(Debug, os, thread, timer)) {
928 _timer_exit_phase3.stop();
929 _timer_exit_phase4.start();
930 }
931
932 #if INCLUDE_JVMCI
933 if (JVMCICounterSize > 0) {
934 if (jvmci_counters_include(this)) {
935 for (int i = 0; i < JVMCICounterSize; i++) {
936 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
937 }
938 }
939 }
940 #endif // INCLUDE_JVMCI
941
942 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
943 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
944 Threads::remove(this, daemon);
945
946 if (log_is_enabled(Debug, os, thread, timer)) {
947 _timer_exit_phase4.stop();
948 log_debug(os, thread, timer)("name='%s'"
949 ", exit-phase1=" JLONG_FORMAT
950 ", exit-phase2=" JLONG_FORMAT
951 ", exit-phase3=" JLONG_FORMAT
952 ", exit-phase4=" JLONG_FORMAT,
953 thread_name,
954 _timer_exit_phase1.milliseconds(),
955 _timer_exit_phase2.milliseconds(),
956 _timer_exit_phase3.milliseconds(),
957 _timer_exit_phase4.milliseconds());
958 os::free(thread_name);
959 }
960 }
961
962 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
963 if (active_handles() != nullptr) {
964 JNIHandleBlock* block = active_handles();
965 set_active_handles(nullptr);
966 JNIHandleBlock::release_block(block);
967 }
968
969 if (free_handle_block() != nullptr) {
970 JNIHandleBlock* block = free_handle_block();
971 set_free_handle_block(nullptr);
972 JNIHandleBlock::release_block(block);
973 }
974
975 // These have to be removed while this is still a valid thread.
976 _stack_overflow_state.remove_stack_guard_pages();
977
978 if (UseTLAB) {
979 tlab().retire();
980 }
981
982 Threads::remove(this, is_daemon);
983 this->smr_delete();
984 }
985
986 JavaThread* JavaThread::active() {
987 Thread* thread = Thread::current();
988 if (thread->is_Java_thread()) {
989 return JavaThread::cast(thread);
990 } else {
991 assert(thread->is_VM_thread(), "this must be a vm thread");
992 VM_Operation* op = ((VMThread*) thread)->vm_operation();
993 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread());
994 return ret;
995 }
996 }
997
998 bool JavaThread::is_lock_owned(address adr) const {
999 assert(LockingMode != LM_LIGHTWEIGHT, "should not be called with new lightweight locking");
1000 if (Thread::is_lock_owned(adr)) return true;
1001
1002 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1003 if (chunk->contains(adr)) return true;
1004 }
1005
1006 return false;
1007 }
1008
1009 oop JavaThread::exception_oop() const {
1010 return Atomic::load(&_exception_oop);
1011 }
1012
1013 void JavaThread::set_exception_oop(oop o) {
1014 Atomic::store(&_exception_oop, o);
1015 }
1016
1017 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1018 chunk->set_next(monitor_chunks());
1019 set_monitor_chunks(chunk);
1020 }
1021
1022 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1023 guarantee(monitor_chunks() != nullptr, "must be non empty");
1024 if (monitor_chunks() == chunk) {
1025 set_monitor_chunks(chunk->next());
1026 } else {
1027 MonitorChunk* prev = monitor_chunks();
1028 while (prev->next() != chunk) prev = prev->next();
1029 prev->set_next(chunk->next());
1030 }
1031 }
1032
1033 void JavaThread::handle_special_runtime_exit_condition() {
1034 if (is_obj_deopt_suspend()) {
1035 frame_anchor()->make_walkable();
1036 wait_for_object_deoptimization();
1037 }
1038 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1039 }
1040
1041
1042 // Asynchronous exceptions support
1043 //
1044 void JavaThread::handle_async_exception(oop java_throwable) {
1045 assert(java_throwable != nullptr, "should have an _async_exception to throw");
1046 assert(!is_at_poll_safepoint(), "should have never called this method");
1047
1048 if (has_last_Java_frame()) {
1049 frame f = last_frame();
1050 if (f.is_runtime_frame()) {
1051 // If the topmost frame is a runtime stub, then we are calling into
1052 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1053 // must deoptimize the caller before continuing, as the compiled exception
1054 // handler table may not be valid.
1055 RegisterMap reg_map(this,
1056 RegisterMap::UpdateMap::skip,
1057 RegisterMap::ProcessFrames::include,
1058 RegisterMap::WalkContinuation::skip);
1059 frame compiled_frame = f.sender(®_map);
1060 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1061 Deoptimization::deoptimize(this, compiled_frame);
1062 }
1063 }
1064 }
1065
1066 // We cannot call Exceptions::_throw(...) here because we cannot block
1067 set_pending_exception(java_throwable, __FILE__, __LINE__);
1068
1069 clear_scopedValueBindings();
1070
1071 LogTarget(Info, exceptions) lt;
1072 if (lt.is_enabled()) {
1073 ResourceMark rm;
1074 LogStream ls(lt);
1075 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1076 if (has_last_Java_frame()) {
1077 frame f = last_frame();
1078 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1079 }
1080 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1081 }
1082 }
1083
1084 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1085 // Do not throw asynchronous exceptions against the compiler thread
1086 // or if the thread is already exiting.
1087 if (!can_call_java() || is_exiting()) {
1088 delete aeh;
1089 return;
1090 }
1091
1092 oop exception = aeh->exception();
1093 Handshake::execute(aeh, this); // Install asynchronous handshake
1094
1095 ResourceMark rm;
1096 if (log_is_enabled(Info, exceptions)) {
1097 log_info(exceptions)("Pending Async. exception installed of type: %s",
1098 InstanceKlass::cast(exception->klass())->external_name());
1099 }
1100 // for AbortVMOnException flag
1101 Exceptions::debug_check_abort(exception->klass()->external_name());
1102
1103 oop vt_oop = vthread();
1104 if (vt_oop == nullptr || !vt_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1105 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1106 java_lang_Thread::set_interrupted(threadObj(), true);
1107 this->interrupt();
1108 }
1109 }
1110
1111 class InstallAsyncExceptionHandshake : public HandshakeClosure {
1112 AsyncExceptionHandshake* _aeh;
1113 public:
1114 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1115 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1116 ~InstallAsyncExceptionHandshake() {
1117 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh.
1118 delete _aeh;
1119 }
1120 void do_thread(Thread* thr) {
1121 JavaThread* target = JavaThread::cast(thr);
1122 target->install_async_exception(_aeh);
1123 _aeh = nullptr;
1124 }
1125 };
1126
1127 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1128 OopHandle e(Universe::vm_global(), java_throwable);
1129 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1130 Handshake::execute(&iaeh, target);
1131 }
1132
1133 #if INCLUDE_JVMTI
1134 void JavaThread::set_is_in_VTMS_transition(bool val) {
1135 _is_in_VTMS_transition = val;
1136 }
1137
1138 #ifdef ASSERT
1139 void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1140 _is_VTMS_transition_disabler = val;
1141 }
1142 #endif
1143 #endif
1144
1145 // External suspension mechanism.
1146 //
1147 // Guarantees on return (for a valid target thread):
1148 // - Target thread will not execute any new bytecode.
1149 // - Target thread will not enter any new monitors.
1150 //
1151 bool JavaThread::java_suspend() {
1152 #if INCLUDE_JVMTI
1153 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1154 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1155 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1156 #endif
1157
1158 guarantee(Thread::is_JavaThread_protected(/* target */ this),
1159 "target JavaThread is not protected in calling context.");
1160 return this->handshake_state()->suspend();
1161 }
1162
1163 bool JavaThread::java_resume() {
1164 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1165 "missing ThreadsListHandle in calling context.");
1166 return this->handshake_state()->resume();
1167 }
1168
1169 // Wait for another thread to perform object reallocation and relocking on behalf of
1170 // this thread. The current thread is required to change to _thread_blocked in order
1171 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1172 // handshake safe, the other thread can complete the handshake used to synchronize
1173 // with this thread and then perform the reallocation and relocking.
1174 // See EscapeBarrier::sync_and_suspend_*()
1175
1176 void JavaThread::wait_for_object_deoptimization() {
1177 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1178 assert(this == Thread::current(), "invariant");
1179
1180 bool spin_wait = os::is_MP();
1181 do {
1182 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1183 // Wait for object deoptimization if requested.
1184 if (spin_wait) {
1185 // A single deoptimization is typically very short. Microbenchmarks
1186 // showed 5% better performance when spinning.
1187 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1188 SpinYield spin(spin_limit);
1189 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1190 spin.wait();
1191 }
1192 // Spin just once
1193 spin_wait = false;
1194 } else {
1195 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1196 if (is_obj_deopt_suspend()) {
1197 ml.wait();
1198 }
1199 }
1200 // A handshake for obj. deoptimization suspend could have been processed so
1201 // we must check after processing.
1202 } while (is_obj_deopt_suspend());
1203 }
1204
1205 #ifdef ASSERT
1206 // Verify the JavaThread has not yet been published in the Threads::list, and
1207 // hence doesn't need protection from concurrent access at this stage.
1208 void JavaThread::verify_not_published() {
1209 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1210 // since an unpublished JavaThread doesn't participate in the
1211 // Thread-SMR protocol for keeping a ThreadsList alive.
1212 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1213 }
1214 #endif
1215
1216 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1217 // pending, when _suspend_flags is non-zero or when we need to process a stack
1218 // watermark. Also check for pending async exceptions (except unsafe access error).
1219 // Note only the native==>Java barriers can call this function when thread state
1220 // is _thread_in_native_trans.
1221 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1222 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1223 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1224
1225 thread->set_thread_state(_thread_in_vm);
1226
1227 // Enable WXWrite: called directly from interpreter native wrapper.
1228 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1229
1230 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1231
1232 // After returning from native, it could be that the stack frames are not
1233 // yet safe to use. We catch such situations in the subsequent stack watermark
1234 // barrier, which will trap unsafe stack frames.
1235 StackWatermarkSet::before_unwind(thread);
1236 }
1237
1238 #ifndef PRODUCT
1239 // Deoptimization
1240 // Function for testing deoptimization
1241 void JavaThread::deoptimize() {
1242 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1243 bool deopt = false; // Dump stack only if a deopt actually happens.
1244 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1245 // Iterate over all frames in the thread and deoptimize
1246 for (; !fst.is_done(); fst.next()) {
1247 if (fst.current()->can_be_deoptimized()) {
1248
1249 if (only_at) {
1250 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1251 // consists of comma or carriage return separated numbers so
1252 // search for the current bci in that string.
1253 address pc = fst.current()->pc();
1254 nmethod* nm = (nmethod*) fst.current()->cb();
1255 ScopeDesc* sd = nm->scope_desc_at(pc);
1256 char buffer[8];
1257 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1258 size_t len = strlen(buffer);
1259 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1260 while (found != nullptr) {
1261 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1262 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1263 // Check that the bci found is bracketed by terminators.
1264 break;
1265 }
1266 found = strstr(found + 1, buffer);
1267 }
1268 if (!found) {
1269 continue;
1270 }
1271 }
1272
1273 if (DebugDeoptimization && !deopt) {
1274 deopt = true; // One-time only print before deopt
1275 tty->print_cr("[BEFORE Deoptimization]");
1276 trace_frames();
1277 trace_stack();
1278 }
1279 Deoptimization::deoptimize(this, *fst.current());
1280 }
1281 }
1282
1283 if (DebugDeoptimization && deopt) {
1284 tty->print_cr("[AFTER Deoptimization]");
1285 trace_frames();
1286 }
1287 }
1288
1289
1290 // Make zombies
1291 void JavaThread::make_zombies() {
1292 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1293 if (fst.current()->can_be_deoptimized()) {
1294 // it is a Java nmethod
1295 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1296 nm->make_not_entrant();
1297 }
1298 }
1299 }
1300 #endif // PRODUCT
1301
1302
1303 void JavaThread::deoptimize_marked_methods() {
1304 if (!has_last_Java_frame()) return;
1305 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1306 for (; !fst.is_done(); fst.next()) {
1307 if (fst.current()->should_be_deoptimized()) {
1308 Deoptimization::deoptimize(this, *fst.current());
1309 }
1310 }
1311 }
1312
1313 #ifdef ASSERT
1314 void JavaThread::verify_frame_info() {
1315 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1316 (has_last_Java_frame() && java_call_counter() > 0),
1317 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1318 has_last_Java_frame() ? "true" : "false", java_call_counter());
1319 }
1320 #endif
1321
1322 // Push on a new block of JNI handles.
1323 void JavaThread::push_jni_handle_block() {
1324 // Allocate a new block for JNI handles.
1325 // Inlined code from jni_PushLocalFrame()
1326 JNIHandleBlock* old_handles = active_handles();
1327 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1328 assert(old_handles != nullptr && new_handles != nullptr, "should not be null");
1329 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1330 set_active_handles(new_handles);
1331 }
1332
1333 // Pop off the current block of JNI handles.
1334 void JavaThread::pop_jni_handle_block() {
1335 // Release our JNI handle block
1336 JNIHandleBlock* old_handles = active_handles();
1337 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1338 assert(new_handles != nullptr, "should never set active handles to null");
1339 set_active_handles(new_handles);
1340 old_handles->set_pop_frame_link(nullptr);
1341 JNIHandleBlock::release_block(old_handles, this);
1342 }
1343
1344 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1345 // Verify that the deferred card marks have been flushed.
1346 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1347
1348 // Traverse the GCHandles
1349 Thread::oops_do_no_frames(f, cf);
1350
1351 if (active_handles() != nullptr) {
1352 active_handles()->oops_do(f);
1353 }
1354
1355 DEBUG_ONLY(verify_frame_info();)
1356
1357 if (has_last_Java_frame()) {
1358 // Traverse the monitor chunks
1359 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1360 chunk->oops_do(f);
1361 }
1362 }
1363
1364 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!");
1365 // If we have deferred set_locals there might be oops waiting to be
1366 // written
1367 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1368 if (list != nullptr) {
1369 for (int i = 0; i < list->length(); i++) {
1370 list->at(i)->oops_do(f);
1371 }
1372 }
1373
1374 // Traverse instance variables at the end since the GC may be moving things
1375 // around using this function
1376 f->do_oop((oop*) &_vm_result);
1377 f->do_oop((oop*) &_exception_oop);
1378 #if INCLUDE_JVMCI
1379 f->do_oop((oop*) &_jvmci_reserved_oop0);
1380 #endif
1381
1382 if (jvmti_thread_state() != nullptr) {
1383 jvmti_thread_state()->oops_do(f, cf);
1384 }
1385
1386 // The continuation oops are really on the stack. But there is typically at most
1387 // one of those per thread, so we handle them here in the oops_do_no_frames part
1388 // so that we don't have to sprinkle as many stack watermark checks where these
1389 // oops are used. We just need to make sure the thread has started processing.
1390 ContinuationEntry* entry = _cont_entry;
1391 while (entry != nullptr) {
1392 f->do_oop((oop*)entry->cont_addr());
1393 f->do_oop((oop*)entry->chunk_addr());
1394 entry = entry->parent();
1395 }
1396
1397 if (LockingMode == LM_LIGHTWEIGHT) {
1398 lock_stack().oops_do(f);
1399 }
1400 }
1401
1402 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
1403 if (!has_last_Java_frame()) {
1404 return;
1405 }
1406 // Finish any pending lazy GC activity for the frames
1407 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc);
1408 // Traverse the execution stack
1409 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1410 fst.current()->oops_do(f, cf, fst.register_map());
1411 }
1412 }
1413
1414 #ifdef ASSERT
1415 void JavaThread::verify_states_for_handshake() {
1416 // This checks that the thread has a correct frame state during a handshake.
1417 verify_frame_info();
1418 }
1419 #endif
1420
1421 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1422 DEBUG_ONLY(verify_frame_info();)
1423 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1424
1425 if (has_last_Java_frame()) {
1426 // Traverse the execution stack
1427 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1428 fst.current()->nmethods_do(cf);
1429 }
1430 }
1431
1432 if (jvmti_thread_state() != nullptr) {
1433 jvmti_thread_state()->nmethods_do(cf);
1434 }
1435 }
1436
1437 void JavaThread::metadata_do(MetadataClosure* f) {
1438 if (has_last_Java_frame()) {
1439 // Traverse the execution stack to call f() on the methods in the stack
1440 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1441 fst.current()->metadata_do(f);
1442 }
1443 } else if (is_Compiler_thread()) {
1444 // need to walk ciMetadata in current compile tasks to keep alive.
1445 CompilerThread* ct = (CompilerThread*)this;
1446 if (ct->env() != nullptr) {
1447 ct->env()->metadata_do(f);
1448 }
1449 CompileTask* task = ct->task();
1450 if (task != nullptr) {
1451 task->metadata_do(f);
1452 }
1453 }
1454 }
1455
1456 // Printing
1457 const char* _get_thread_state_name(JavaThreadState _thread_state) {
1458 switch (_thread_state) {
1459 case _thread_uninitialized: return "_thread_uninitialized";
1460 case _thread_new: return "_thread_new";
1461 case _thread_new_trans: return "_thread_new_trans";
1462 case _thread_in_native: return "_thread_in_native";
1463 case _thread_in_native_trans: return "_thread_in_native_trans";
1464 case _thread_in_vm: return "_thread_in_vm";
1465 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1466 case _thread_in_Java: return "_thread_in_Java";
1467 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1468 case _thread_blocked: return "_thread_blocked";
1469 case _thread_blocked_trans: return "_thread_blocked_trans";
1470 default: return "unknown thread state";
1471 }
1472 }
1473
1474 void JavaThread::print_thread_state_on(outputStream *st) const {
1475 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1476 }
1477
1478 // Called by Threads::print() for VM_PrintThreads operation
1479 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1480 st->print_raw("\"");
1481 st->print_raw(name());
1482 st->print_raw("\" ");
1483 oop thread_oop = threadObj();
1484 if (thread_oop != nullptr) {
1485 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1486 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1487 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1488 }
1489 Thread::print_on(st, print_extended_info);
1490 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1491 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1492 if (thread_oop != nullptr) {
1493 if (is_vthread_mounted()) {
1494 oop vt = vthread();
1495 assert(vt != nullptr, "");
1496 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1497 } else {
1498 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1499 }
1500 }
1501 #ifndef PRODUCT
1502 _safepoint_state->print_on(st);
1503 #endif // PRODUCT
1504 if (is_Compiler_thread()) {
1505 CompileTask *task = ((CompilerThread*)this)->task();
1506 if (task != nullptr) {
1507 st->print(" Compiling: ");
1508 task->print(st, nullptr, true, false);
1509 } else {
1510 st->print(" No compile task");
1511 }
1512 st->cr();
1513 }
1514 }
1515
1516 void JavaThread::print() const { print_on(tty); }
1517
1518 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1519 st->print("%s", get_thread_name_string(buf, buflen));
1520 }
1521
1522 // Called by fatal error handler. The difference between this and
1523 // JavaThread::print() is that we can't grab lock or allocate memory.
1524 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1525 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1526 Thread* current = Thread::current_or_null_safe();
1527 assert(current != nullptr, "cannot be called by a detached thread");
1528 st->fill_to(60);
1529 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1530 // Only access threadObj() if current thread is not a JavaThread
1531 // or if it is a JavaThread that can safely access oops.
1532 oop thread_obj = threadObj();
1533 if (thread_obj != nullptr) {
1534 st->print(java_lang_Thread::is_daemon(thread_obj) ? " daemon" : " ");
1535 }
1536 }
1537 st->print(" [");
1538 st->print("%s", _get_thread_state_name(_thread_state));
1539 if (osthread()) {
1540 st->print(", id=%d", osthread()->thread_id());
1541 }
1542 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ") (" PROPERFMT ")",
1543 p2i(stack_end()), p2i(stack_base()),
1544 PROPERFMTARGS(stack_size()));
1545 st->print("]");
1546
1547 ThreadsSMRSupport::print_info_on(this, st);
1548 return;
1549 }
1550
1551
1552 // Verification
1553
1554 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1555 // ignore if there is no stack
1556 if (!has_last_Java_frame()) return;
1557 // traverse the stack frames. Starts from top frame.
1558 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1559 frame* fr = fst.current();
1560 f(fr, fst.register_map());
1561 }
1562 }
1563
1564 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1565
1566 void JavaThread::verify() {
1567 // Verify oops in the thread.
1568 oops_do(&VerifyOopClosure::verify_oop, nullptr);
1569
1570 // Verify the stack frames.
1571 frames_do(frame_verify);
1572 }
1573
1574 // CR 6300358 (sub-CR 2137150)
1575 // Most callers of this method assume that it can't return null but a
1576 // thread may not have a name whilst it is in the process of attaching to
1577 // the VM - see CR 6412693, and there are places where a JavaThread can be
1578 // seen prior to having its threadObj set (e.g., JNI attaching threads and
1579 // if vm exit occurs during initialization). These cases can all be accounted
1580 // for such that this method never returns null.
1581 const char* JavaThread::name() const {
1582 if (Thread::is_JavaThread_protected(/* target */ this)) {
1583 // The target JavaThread is protected so get_thread_name_string() is safe:
1584 return get_thread_name_string();
1585 }
1586
1587 // The target JavaThread is not protected so we return the default:
1588 return Thread::name();
1589 }
1590
1591 // Returns a non-null representation of this thread's name, or a suitable
1592 // descriptive string if there is no set name.
1593 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1594 const char* name_str;
1595 #ifdef ASSERT
1596 Thread* current = Thread::current_or_null_safe();
1597 assert(current != nullptr, "cannot be called by a detached thread");
1598 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1599 // Only access threadObj() if current thread is not a JavaThread
1600 // or if it is a JavaThread that can safely access oops.
1601 #endif
1602 oop thread_obj = threadObj();
1603 if (thread_obj != nullptr) {
1604 oop name = java_lang_Thread::name(thread_obj);
1605 if (name != nullptr) {
1606 if (buf == nullptr) {
1607 name_str = java_lang_String::as_utf8_string(name);
1608 } else {
1609 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1610 }
1611 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1612 name_str = "<no-name - thread is attaching>";
1613 } else {
1614 name_str = "<un-named>";
1615 }
1616 } else {
1617 name_str = Thread::name();
1618 }
1619 #ifdef ASSERT
1620 } else {
1621 // Current JavaThread has exited...
1622 if (current == this) {
1623 // ... and is asking about itself:
1624 name_str = "<no-name - current JavaThread has exited>";
1625 } else {
1626 // ... and it can't safely determine this JavaThread's name so
1627 // use the default thread name.
1628 name_str = Thread::name();
1629 }
1630 }
1631 #endif
1632 assert(name_str != nullptr, "unexpected null thread name");
1633 return name_str;
1634 }
1635
1636 // Helper to extract the name from the thread oop for logging.
1637 const char* JavaThread::name_for(oop thread_obj) {
1638 assert(thread_obj != nullptr, "precondition");
1639 oop name = java_lang_Thread::name(thread_obj);
1640 const char* name_str;
1641 if (name != nullptr) {
1642 name_str = java_lang_String::as_utf8_string(name);
1643 } else {
1644 name_str = "<un-named>";
1645 }
1646 return name_str;
1647 }
1648
1649 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1650
1651 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1652 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1653 // Link Java Thread object <-> C++ Thread
1654
1655 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1656 // and put it into a new Handle. The Handle "thread_oop" can then
1657 // be used to pass the C++ thread object to other methods.
1658
1659 // Set the Java level thread object (jthread) field of the
1660 // new thread (a JavaThread *) to C++ thread object using the
1661 // "thread_oop" handle.
1662
1663 // Set the thread field (a JavaThread *) of the
1664 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1665
1666 Handle thread_oop(Thread::current(),
1667 JNIHandles::resolve_non_null(jni_thread));
1668 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1669 "must be initialized");
1670 set_threadOopHandles(thread_oop());
1671
1672 if (prio == NoPriority) {
1673 prio = java_lang_Thread::priority(thread_oop());
1674 assert(prio != NoPriority, "A valid priority should be present");
1675 }
1676
1677 // Push the Java priority down to the native thread; needs Threads_lock
1678 Thread::set_priority(this, prio);
1679
1680 // Add the new thread to the Threads list and set it in motion.
1681 // We must have threads lock in order to call Threads::add.
1682 // It is crucial that we do not block before the thread is
1683 // added to the Threads list for if a GC happens, then the java_thread oop
1684 // will not be visited by GC.
1685 Threads::add(this);
1686 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
1687 // on a ThreadsList. We don't want to wait for the release when the
1688 // Theads_lock is dropped somewhere in the caller since the JavaThread*
1689 // is already visible to JVM/TI via the ThreadsList.
1690 java_lang_Thread::release_set_thread(thread_oop(), this);
1691 }
1692
1693 oop JavaThread::current_park_blocker() {
1694 // Support for JSR-166 locks
1695 oop thread_oop = threadObj();
1696 if (thread_oop != nullptr) {
1697 return java_lang_Thread::park_blocker(thread_oop);
1698 }
1699 return nullptr;
1700 }
1701
1702 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1703 // This is the external format, selecting the platform or vthread
1704 // as applicable, and allowing for a native-only stack.
1705 void JavaThread::print_jni_stack() {
1706 assert(this == JavaThread::current(), "Can't print stack of other threads");
1707 if (!has_last_Java_frame()) {
1708 ResourceMark rm(this);
1709 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
1710 if (buf == nullptr) {
1711 tty->print_cr("Unable to print native stack - out of memory");
1712 return;
1713 }
1714 address lastpc = nullptr;
1715 if (os::platform_print_native_stack(tty, nullptr, buf, O_BUFLEN, lastpc)) {
1716 // We have printed the native stack in platform-specific code,
1717 // so nothing else to do in this case.
1718 } else {
1719 frame f = os::current_frame();
1720 VMError::print_native_stack(tty, f, this, true /*print_source_info */,
1721 -1 /* max stack */, buf, O_BUFLEN);
1722 }
1723 } else {
1724 print_active_stack_on(tty);
1725 }
1726 }
1727
1728 void JavaThread::print_stack_on(outputStream* st) {
1729 if (!has_last_Java_frame()) return;
1730
1731 Thread* current_thread = Thread::current();
1732 ResourceMark rm(current_thread);
1733 HandleMark hm(current_thread);
1734
1735 RegisterMap reg_map(this,
1736 RegisterMap::UpdateMap::include,
1737 RegisterMap::ProcessFrames::include,
1738 RegisterMap::WalkContinuation::skip);
1739 vframe* start_vf = platform_thread_last_java_vframe(®_map);
1740 int count = 0;
1741 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1742 if (f->is_java_frame()) {
1743 javaVFrame* jvf = javaVFrame::cast(f);
1744 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1745
1746 // Print out lock information
1747 if (JavaMonitorsInStackTrace) {
1748 jvf->print_lock_info_on(st, count);
1749 }
1750 } else {
1751 // Ignore non-Java frames
1752 }
1753
1754 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1755 count++;
1756 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1757 }
1758 }
1759
1760 void JavaThread::print_vthread_stack_on(outputStream* st) {
1761 assert(is_vthread_mounted(), "Caller should have checked this");
1762 assert(has_last_Java_frame(), "must be");
1763
1764 Thread* current_thread = Thread::current();
1765 ResourceMark rm(current_thread);
1766 HandleMark hm(current_thread);
1767
1768 RegisterMap reg_map(this,
1769 RegisterMap::UpdateMap::include,
1770 RegisterMap::ProcessFrames::include,
1771 RegisterMap::WalkContinuation::include);
1772 ContinuationEntry* cont_entry = last_continuation();
1773 vframe* start_vf = last_java_vframe(®_map);
1774 int count = 0;
1775 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1776 // Watch for end of vthread stack
1777 if (Continuation::is_continuation_enterSpecial(f->fr())) {
1778 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), "");
1779 if (cont_entry->is_virtual_thread()) {
1780 break;
1781 }
1782 cont_entry = cont_entry->parent();
1783 }
1784 if (f->is_java_frame()) {
1785 javaVFrame* jvf = javaVFrame::cast(f);
1786 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1787
1788 // Print out lock information
1789 if (JavaMonitorsInStackTrace) {
1790 jvf->print_lock_info_on(st, count);
1791 }
1792 } else {
1793 // Ignore non-Java frames
1794 }
1795
1796 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1797 count++;
1798 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1799 }
1800 }
1801
1802 void JavaThread::print_active_stack_on(outputStream* st) {
1803 if (is_vthread_mounted()) {
1804 print_vthread_stack_on(st);
1805 } else {
1806 print_stack_on(st);
1807 }
1808 }
1809
1810 #if INCLUDE_JVMTI
1811 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1812 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1813 set_jvmti_vthread(thread_oop);
1814
1815 // unbind current JvmtiThreadState from JavaThread
1816 JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1817
1818 // bind new JvmtiThreadState to JavaThread
1819 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1820
1821 return jvmti_thread_state();
1822 }
1823 #endif
1824
1825 // JVMTI PopFrame support
1826 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1827 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments");
1828 if (in_bytes(size_in_bytes) != 0) {
1829 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1830 _popframe_preserved_args_size = in_bytes(size_in_bytes);
1831 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1832 }
1833 }
1834
1835 void* JavaThread::popframe_preserved_args() {
1836 return _popframe_preserved_args;
1837 }
1838
1839 ByteSize JavaThread::popframe_preserved_args_size() {
1840 return in_ByteSize(_popframe_preserved_args_size);
1841 }
1842
1843 WordSize JavaThread::popframe_preserved_args_size_in_words() {
1844 int sz = in_bytes(popframe_preserved_args_size());
1845 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1846 return in_WordSize(sz / wordSize);
1847 }
1848
1849 void JavaThread::popframe_free_preserved_args() {
1850 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice");
1851 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1852 _popframe_preserved_args = nullptr;
1853 _popframe_preserved_args_size = 0;
1854 }
1855
1856 #ifndef PRODUCT
1857
1858 void JavaThread::trace_frames() {
1859 tty->print_cr("[Describe stack]");
1860 int frame_no = 1;
1861 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1862 tty->print(" %d. ", frame_no++);
1863 fst.current()->print_value_on(tty, this);
1864 tty->cr();
1865 }
1866 }
1867
1868 class PrintAndVerifyOopClosure: public OopClosure {
1869 protected:
1870 template <class T> inline void do_oop_work(T* p) {
1871 oop obj = RawAccess<>::oop_load(p);
1872 if (obj == nullptr) return;
1873 tty->print(INTPTR_FORMAT ": ", p2i(p));
1874 if (oopDesc::is_oop_or_null(obj)) {
1875 if (obj->is_objArray()) {
1876 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1877 } else {
1878 obj->print();
1879 }
1880 } else {
1881 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1882 }
1883 tty->cr();
1884 }
1885 public:
1886 virtual void do_oop(oop* p) { do_oop_work(p); }
1887 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1888 };
1889
1890 #ifdef ASSERT
1891 // Print or validate the layout of stack frames
1892 void JavaThread::print_frame_layout(int depth, bool validate_only) {
1893 ResourceMark rm;
1894 PreserveExceptionMark pm(this);
1895 FrameValues values;
1896 int frame_no = 0;
1897 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1898 fst.current()->describe(values, ++frame_no, fst.register_map());
1899 if (depth == frame_no) break;
1900 }
1901 Continuation::describe(values);
1902 if (validate_only) {
1903 values.validate();
1904 } else {
1905 tty->print_cr("[Describe stack layout]");
1906 values.print(this);
1907 }
1908 }
1909 #endif
1910
1911 void JavaThread::trace_stack_from(vframe* start_vf) {
1912 ResourceMark rm;
1913 int vframe_no = 1;
1914 for (vframe* f = start_vf; f; f = f->sender()) {
1915 if (f->is_java_frame()) {
1916 javaVFrame::cast(f)->print_activation(vframe_no++);
1917 } else {
1918 f->print();
1919 }
1920 if (vframe_no > StackPrintLimit) {
1921 tty->print_cr("...<more frames>...");
1922 return;
1923 }
1924 }
1925 }
1926
1927
1928 void JavaThread::trace_stack() {
1929 if (!has_last_Java_frame()) return;
1930 Thread* current_thread = Thread::current();
1931 ResourceMark rm(current_thread);
1932 HandleMark hm(current_thread);
1933 RegisterMap reg_map(this,
1934 RegisterMap::UpdateMap::include,
1935 RegisterMap::ProcessFrames::include,
1936 RegisterMap::WalkContinuation::skip);
1937 trace_stack_from(last_java_vframe(®_map));
1938 }
1939
1940
1941 #endif // PRODUCT
1942
1943 void JavaThread::inc_held_monitor_count(intx i, bool jni) {
1944 #ifdef SUPPORT_MONITOR_COUNT
1945 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _held_monitor_count);
1946 _held_monitor_count += i;
1947 if (jni) {
1948 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _jni_monitor_count);
1949 _jni_monitor_count += i;
1950 }
1951 #endif
1952 }
1953
1954 void JavaThread::dec_held_monitor_count(intx i, bool jni) {
1955 #ifdef SUPPORT_MONITOR_COUNT
1956 _held_monitor_count -= i;
1957 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _held_monitor_count);
1958 if (jni) {
1959 _jni_monitor_count -= i;
1960 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _jni_monitor_count);
1961 }
1962 #endif
1963 }
1964
1965 frame JavaThread::vthread_last_frame() {
1966 assert (is_vthread_mounted(), "Virtual thread not mounted");
1967 return last_frame();
1968 }
1969
1970 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
1971 const ContinuationEntry* entry = vthread_continuation();
1972 guarantee (entry != nullptr, "Not a carrier thread");
1973 frame f = entry->to_frame();
1974 if (reg_map->process_frames()) {
1975 entry->flush_stack_processing(this);
1976 }
1977 entry->update_register_map(reg_map);
1978 return f.sender(reg_map);
1979 }
1980
1981 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
1982 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
1983 }
1984
1985 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
1986 assert(reg_map != nullptr, "a map must be given");
1987 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
1988 if (vf->is_java_frame()) return javaVFrame::cast(vf);
1989 }
1990 return nullptr;
1991 }
1992
1993 Klass* JavaThread::security_get_caller_class(int depth) {
1994 ResetNoHandleMark rnhm;
1995 HandleMark hm(Thread::current());
1996
1997 vframeStream vfst(this);
1998 vfst.security_get_caller_frame(depth);
1999 if (!vfst.at_end()) {
2000 return vfst.method()->method_holder();
2001 }
2002 return nullptr;
2003 }
2004
2005 // Internal convenience function for millisecond resolution sleeps.
2006 bool JavaThread::sleep(jlong millis) {
2007 jlong nanos;
2008 if (millis > max_jlong / NANOUNITS_PER_MILLIUNIT) {
2009 // Conversion to nanos would overflow, saturate at max
2010 nanos = max_jlong;
2011 } else {
2012 nanos = millis * NANOUNITS_PER_MILLIUNIT;
2013 }
2014 return sleep_nanos(nanos);
2015 }
2016
2017 // java.lang.Thread.sleep support
2018 // Returns true if sleep time elapsed as expected, and false
2019 // if the thread was interrupted.
2020 bool JavaThread::sleep_nanos(jlong nanos) {
2021 assert(this == Thread::current(), "thread consistency check");
2022 assert(nanos >= 0, "nanos are in range");
2023
2024 ParkEvent * const slp = this->_SleepEvent;
2025 // Because there can be races with thread interruption sending an unpark()
2026 // to the event, we explicitly reset it here to avoid an immediate return.
2027 // The actual interrupt state will be checked before we park().
2028 slp->reset();
2029 // Thread interruption establishes a happens-before ordering in the
2030 // Java Memory Model, so we need to ensure we synchronize with the
2031 // interrupt state.
2032 OrderAccess::fence();
2033
2034 jlong prevtime = os::javaTimeNanos();
2035
2036 jlong nanos_remaining = nanos;
2037
2038 for (;;) {
2039 // interruption has precedence over timing out
2040 if (this->is_interrupted(true)) {
2041 return false;
2042 }
2043
2044 if (nanos_remaining <= 0) {
2045 return true;
2046 }
2047
2048 {
2049 ThreadBlockInVM tbivm(this);
2050 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2051 slp->park_nanos(nanos_remaining);
2052 }
2053
2054 // Update elapsed time tracking
2055 jlong newtime = os::javaTimeNanos();
2056 if (newtime - prevtime < 0) {
2057 // time moving backwards, should only happen if no monotonic clock
2058 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2059 assert(false,
2060 "unexpected time moving backwards detected in JavaThread::sleep()");
2061 } else {
2062 nanos_remaining -= (newtime - prevtime);
2063 }
2064 prevtime = newtime;
2065 }
2066 }
2067
2068 // Last thread running calls java.lang.Shutdown.shutdown()
2069 void JavaThread::invoke_shutdown_hooks() {
2070 HandleMark hm(this);
2071
2072 // We could get here with a pending exception, if so clear it now.
2073 if (this->has_pending_exception()) {
2074 this->clear_pending_exception();
2075 }
2076
2077 EXCEPTION_MARK;
2078 Klass* shutdown_klass =
2079 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
2080 THREAD);
2081 if (shutdown_klass != nullptr) {
2082 // SystemDictionary::resolve_or_null will return null if there was
2083 // an exception. If we cannot load the Shutdown class, just don't
2084 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
2085 // won't be run. Note that if a shutdown hook was registered,
2086 // the Shutdown class would have already been loaded
2087 // (Runtime.addShutdownHook will load it).
2088 JavaValue result(T_VOID);
2089 JavaCalls::call_static(&result,
2090 shutdown_klass,
2091 vmSymbols::shutdown_name(),
2092 vmSymbols::void_method_signature(),
2093 THREAD);
2094 }
2095 CLEAR_PENDING_EXCEPTION;
2096 }
2097
2098 #ifndef PRODUCT
2099 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
2100 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
2101 }
2102 #endif
2103
2104 // Helper function to create the java.lang.Thread object for a
2105 // VM-internal thread. The thread will have the given name, and be
2106 // a member of the "system" ThreadGroup.
2107 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) {
2108 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2109
2110 // Initialize thread_oop to put it into the system threadGroup.
2111 // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2112 Handle thread_group(THREAD, Universe::system_thread_group());
2113 Handle thread_oop =
2114 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2115 vmSymbols::threadgroup_string_void_signature(),
2116 thread_group,
2117 string,
2118 CHECK_NH);
2119
2120 return thread_oop;
2121 }
2122
2123 // Starts the target JavaThread as a daemon of the given priority, and
2124 // bound to the given java.lang.Thread instance.
2125 // The Threads_lock is held for the duration.
2126 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2127 Handle thread_oop, ThreadPriority prio) {
2128
2129 assert(target->osthread() != nullptr, "target thread is not properly initialized");
2130
2131 MutexLocker mu(current, Threads_lock);
2132
2133 // Initialize the fields of the thread_oop first.
2134 if (prio != NoPriority) {
2135 java_lang_Thread::set_priority(thread_oop(), prio);
2136 // Note: we don't call os::set_priority here. Possibly we should,
2137 // else all threads should call it themselves when they first run.
2138 }
2139
2140 java_lang_Thread::set_daemon(thread_oop());
2141
2142 // Now bind the thread_oop to the target JavaThread.
2143 target->set_threadOopHandles(thread_oop());
2144
2145 Threads::add(target); // target is now visible for safepoint/handshake
2146 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
2147 // on a ThreadsList. We don't want to wait for the release when the
2148 // Theads_lock is dropped when the 'mu' destructor is run since the
2149 // JavaThread* is already visible to JVM/TI via the ThreadsList.
2150 java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now
2151 Thread::start(target);
2152 }
2153
2154 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2155 // At this point it may be possible that no osthread was created for the
2156 // JavaThread due to lack of resources. However, since this must work
2157 // for critical system threads just check and abort if this fails.
2158 if (thread->osthread() == nullptr) {
2159 // This isn't really an OOM condition, but historically this is what
2160 // we report.
2161 vm_exit_during_initialization("java.lang.OutOfMemoryError",
2162 os::native_thread_creation_failed_msg());
2163 }
2164 }
2165
2166 void JavaThread::pretouch_stack() {
2167 // Given an established java thread stack with usable area followed by
2168 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging
2169 // from the current frame down to the start of the shadow zone.
2170 const address end = _stack_overflow_state.shadow_zone_safe_limit();
2171 if (is_in_full_stack(end)) {
2172 char* p1 = (char*) alloca(1);
2173 address here = (address) &p1;
2174 if (is_in_full_stack(here) && here > end) {
2175 size_t to_alloc = here - end;
2176 char* p2 = (char*) alloca(to_alloc);
2177 log_trace(os, thread)("Pretouching thread stack from " PTR_FORMAT " to " PTR_FORMAT ".",
2178 p2i(p2), p2i(end));
2179 os::pretouch_memory(p2, p2 + to_alloc,
2180 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096));
2181 }
2182 }
2183 }
2184
2185 // Deferred OopHandle release support.
2186
2187 class OopHandleList : public CHeapObj<mtInternal> {
2188 static const int _count = 4;
2189 OopHandle _handles[_count];
2190 OopHandleList* _next;
2191 int _index;
2192 public:
2193 OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2194 void add(OopHandle h) {
2195 assert(_index < _count, "too many additions");
2196 _handles[_index++] = h;
2197 }
2198 ~OopHandleList() {
2199 assert(_index == _count, "usage error");
2200 for (int i = 0; i < _index; i++) {
2201 _handles[i].release(JavaThread::thread_oop_storage());
2202 }
2203 }
2204 OopHandleList* next() const { return _next; }
2205 };
2206
2207 OopHandleList* JavaThread::_oop_handle_list = nullptr;
2208
2209 // Called by the ServiceThread to do the work of releasing
2210 // the OopHandles.
2211 void JavaThread::release_oop_handles() {
2212 OopHandleList* list;
2213 {
2214 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2215 list = _oop_handle_list;
2216 _oop_handle_list = nullptr;
2217 }
2218 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2219
2220 while (list != nullptr) {
2221 OopHandleList* l = list;
2222 list = l->next();
2223 delete l;
2224 }
2225 }
2226
2227 // Add our OopHandles for later release.
2228 void JavaThread::add_oop_handles_for_release() {
2229 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2230 OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2231 new_head->add(_threadObj);
2232 new_head->add(_vthread);
2233 new_head->add(_jvmti_vthread);
2234 new_head->add(_scopedValueCache);
2235 _oop_handle_list = new_head;
2236 Service_lock->notify_all();
2237 }