1 /*
2 * Copyright (c) 1997, 2024, 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.is_empty()) { // 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 static 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 static 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 _is_disable_suspend(false),
444 #ifdef ASSERT
445 _is_VTMS_transition_disabler(false),
446 #endif
447 #endif
448 _jni_attach_state(_not_attaching_via_jni),
449 #if INCLUDE_JVMCI
450 _pending_deoptimization(-1),
451 _pending_monitorenter(false),
452 _pending_transfer_to_interpreter(false),
453 _in_retryable_allocation(false),
454 _pending_failed_speculation(0),
455 _jvmci{nullptr},
456 _libjvmci_runtime(nullptr),
457 _jvmci_counters(nullptr),
458 _jvmci_reserved0(0),
459 _jvmci_reserved1(0),
460 _jvmci_reserved_oop0(nullptr),
461 #endif // INCLUDE_JVMCI
462
463 _exception_oop(oop()),
464 _exception_pc(0),
465 _exception_handler_pc(0),
466 _is_method_handle_return(0),
467
468 _jni_active_critical(0),
469 _pending_jni_exception_check_fn(nullptr),
470 _depth_first_number(0),
471
472 // JVMTI PopFrame support
473 _popframe_condition(popframe_inactive),
474 _frames_to_pop_failed_realloc(0),
475
476 _cont_entry(nullptr),
477 _cont_fastpath(0),
478 _cont_fastpath_thread_state(1),
479 _held_monitor_count(0),
480 _jni_monitor_count(0),
481
482 _handshake(this),
483
484 _popframe_preserved_args(nullptr),
485 _popframe_preserved_args_size(0),
486
487 _jvmti_thread_state(nullptr),
488 _interp_only_mode(0),
489 _should_post_on_exceptions_flag(JNI_FALSE),
490 _thread_stat(new ThreadStatistics()),
491
492 _parker(),
493
494 _class_to_be_initialized(nullptr),
495
496 _SleepEvent(ParkEvent::Allocate(this)),
497
498 _lock_stack(this) {
499 set_jni_functions(jni_functions());
500
501 #if INCLUDE_JVMCI
502 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
503 if (JVMCICounterSize > 0) {
504 resize_counters(0, (int) JVMCICounterSize);
505 }
506 #endif // INCLUDE_JVMCI
507
508 // Setup safepoint state info for this thread
509 ThreadSafepointState::create(this);
510
511 SafepointMechanism::initialize_header(this);
512
513 set_requires_cross_modify_fence(false);
514
515 pd_initialize();
516 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
517 }
518
519 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
520 if (is_attaching_via_jni) {
521 _jni_attach_state = _attaching_via_jni;
522 }
523 }
524
525
526 // interrupt support
527
528 void JavaThread::interrupt() {
529 // All callers should have 'this' thread protected by a
530 // ThreadsListHandle so that it cannot terminate and deallocate
531 // itself.
532 debug_only(check_for_dangling_thread_pointer(this);)
533
534 // For Windows _interrupt_event
535 WINDOWS_ONLY(osthread()->set_interrupted(true);)
536
537 // For Thread.sleep
538 _SleepEvent->unpark();
539
540 // For JSR166 LockSupport.park
541 parker()->unpark();
542
543 // For ObjectMonitor and JvmtiRawMonitor
544 _ParkEvent->unpark();
545 }
546
547
548 bool JavaThread::is_interrupted(bool clear_interrupted) {
549 debug_only(check_for_dangling_thread_pointer(this);)
550
551 if (_threadObj.peek() == nullptr) {
552 // If there is no j.l.Thread then it is impossible to have
553 // been interrupted. We can find null during VM initialization
554 // or when a JNI thread is still in the process of attaching.
555 // In such cases this must be the current thread.
556 assert(this == Thread::current(), "invariant");
557 return false;
558 }
559
560 bool interrupted = java_lang_Thread::interrupted(threadObj());
561
562 // NOTE that since there is no "lock" around the interrupt and
563 // is_interrupted operations, there is the possibility that the
564 // interrupted flag will be "false" but that the
565 // low-level events will be in the signaled state. This is
566 // intentional. The effect of this is that Object.wait() and
567 // LockSupport.park() will appear to have a spurious wakeup, which
568 // is allowed and not harmful, and the possibility is so rare that
569 // it is not worth the added complexity to add yet another lock.
570 // For the sleep event an explicit reset is performed on entry
571 // to JavaThread::sleep, so there is no early return. It has also been
572 // recommended not to put the interrupted flag into the "event"
573 // structure because it hides the issue.
574 // Also, because there is no lock, we must only clear the interrupt
575 // state if we are going to report that we were interrupted; otherwise
576 // an interrupt that happens just after we read the field would be lost.
577 if (interrupted && clear_interrupted) {
578 assert(this == Thread::current(), "only the current thread can clear");
579 java_lang_Thread::set_interrupted(threadObj(), false);
580 WINDOWS_ONLY(osthread()->set_interrupted(false);)
581 }
582
583 return interrupted;
584 }
585
586 void JavaThread::block_if_vm_exited() {
587 if (_terminated == _vm_exited) {
588 // _vm_exited is set at safepoint, and Threads_lock is never released
589 // so we will block here forever.
590 // Here we can be doing a jump from a safe state to an unsafe state without
591 // proper transition, but it happens after the final safepoint has begun so
592 // this jump won't cause any safepoint problems.
593 set_thread_state(_thread_in_vm);
594 Threads_lock->lock();
595 ShouldNotReachHere();
596 }
597 }
598
599 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
600 _jni_attach_state = _not_attaching_via_jni;
601 set_entry_point(entry_point);
602 // Create the native thread itself.
603 // %note runtime_23
604 os::ThreadType thr_type = os::java_thread;
605 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
606 os::java_thread;
607 os::create_thread(this, thr_type, stack_sz);
608 // The _osthread may be null here because we ran out of memory (too many threads active).
609 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
610 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
611 // the exception consists of creating the exception object & initializing it, initialization
612 // will leave the VM via a JavaCall and then all locks must be unlocked).
613 //
614 // The thread is still suspended when we reach here. Thread must be explicit started
615 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
616 // by calling Threads:add. The reason why this is not done here, is because the thread
617 // object must be fully initialized (take a look at JVM_Start)
618 }
619
620 JavaThread::~JavaThread() {
621
622 // Enqueue OopHandles for release by the service thread.
623 add_oop_handles_for_release();
624
625 // Return the sleep event to the free list
626 ParkEvent::Release(_SleepEvent);
627 _SleepEvent = nullptr;
628
629 // Free any remaining previous UnrollBlock
630 vframeArray* old_array = vframe_array_last();
631
632 if (old_array != nullptr) {
633 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
634 old_array->set_unroll_block(nullptr);
635 delete old_info;
636 delete old_array;
637 }
638
639 JvmtiDeferredUpdates* updates = deferred_updates();
640 if (updates != nullptr) {
641 // This can only happen if thread is destroyed before deoptimization occurs.
642 assert(updates->count() > 0, "Updates holder not deleted");
643 // free deferred updates.
644 delete updates;
645 set_deferred_updates(nullptr);
646 }
647
648 // All Java related clean up happens in exit
649 ThreadSafepointState::destroy(this);
650 if (_thread_stat != nullptr) delete _thread_stat;
651
652 #if INCLUDE_JVMCI
653 if (JVMCICounterSize > 0) {
654 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
655 }
656 #endif // INCLUDE_JVMCI
657 }
658
659
660 // First JavaThread specific code executed by a new Java thread.
661 void JavaThread::pre_run() {
662 // empty - see comments in run()
663 }
664
665 // The main routine called by a new Java thread. This isn't overridden
666 // by subclasses, instead different subclasses define a different "entry_point"
667 // which defines the actual logic for that kind of thread.
668 void JavaThread::run() {
669 // initialize thread-local alloc buffer related fields
670 initialize_tlab();
671
672 _stack_overflow_state.create_stack_guard_pages();
673
674 cache_global_variables();
675
676 // Thread is now sufficiently initialized to be handled by the safepoint code as being
677 // in the VM. Change thread state from _thread_new to _thread_in_vm
678 assert(this->thread_state() == _thread_new, "wrong thread state");
679 set_thread_state(_thread_in_vm);
680
681 // Before a thread is on the threads list it is always safe, so after leaving the
682 // _thread_new we should emit a instruction barrier. The distance to modified code
683 // from here is probably far enough, but this is consistent and safe.
684 OrderAccess::cross_modify_fence();
685
686 assert(JavaThread::current() == this, "sanity check");
687 assert(!Thread::current()->owns_locks(), "sanity check");
688
689 DTRACE_THREAD_PROBE(start, this);
690
691 // This operation might block. We call that after all safepoint checks for a new thread has
692 // been completed.
693 set_active_handles(JNIHandleBlock::allocate_block());
694
695 if (JvmtiExport::should_post_thread_life()) {
696 JvmtiExport::post_thread_start(this);
697
698 }
699
700 if (AlwaysPreTouchStacks) {
701 pretouch_stack();
702 }
703
704 // We call another function to do the rest so we are sure that the stack addresses used
705 // from there will be lower than the stack base just computed.
706 thread_main_inner();
707 }
708
709 void JavaThread::thread_main_inner() {
710 assert(JavaThread::current() == this, "sanity check");
711 assert(_threadObj.peek() != nullptr, "just checking");
712
713 // Execute thread entry point unless this thread has a pending exception.
714 // Note: Due to JVMTI StopThread we can have pending exceptions already!
715 if (!this->has_pending_exception()) {
716 {
717 ResourceMark rm(this);
718 this->set_native_thread_name(this->name());
719 }
720 HandleMark hm(this);
721 this->entry_point()(this, this);
722 }
723
724 DTRACE_THREAD_PROBE(stop, this);
725
726 // Cleanup is handled in post_run()
727 }
728
729 // Shared teardown for all JavaThreads
730 void JavaThread::post_run() {
731 this->exit(false);
732 this->unregister_thread_stack_with_NMT();
733 // Defer deletion to here to ensure 'this' is still referenceable in call_run
734 // for any shared tear-down.
735 this->smr_delete();
736 }
737
738 static void ensure_join(JavaThread* thread) {
739 // We do not need to grab the Threads_lock, since we are operating on ourself.
740 Handle threadObj(thread, thread->threadObj());
741 assert(threadObj.not_null(), "java thread object must exist");
742 ObjectLocker lock(threadObj, thread);
743 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
744 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
745 // Clear the native thread instance - this makes isAlive return false and allows the join()
746 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model
747 // requirements.
748 assert(java_lang_Thread::thread(threadObj()) == thread, "must be alive");
749 java_lang_Thread::release_set_thread(threadObj(), nullptr);
750 lock.notify_all(thread);
751 // Ignore pending exception, since we are exiting anyway
752 thread->clear_pending_exception();
753 }
754
755 static bool is_daemon(oop threadObj) {
756 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj));
757 }
758
759 // For any new cleanup additions, please check to see if they need to be applied to
760 // cleanup_failed_attach_current_thread as well.
761 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
762 assert(this == JavaThread::current(), "thread consistency check");
763 assert(!is_exiting(), "should not be exiting or terminated already");
764
765 elapsedTimer _timer_exit_phase1;
766 elapsedTimer _timer_exit_phase2;
767 elapsedTimer _timer_exit_phase3;
768 elapsedTimer _timer_exit_phase4;
769
770 if (log_is_enabled(Debug, os, thread, timer)) {
771 _timer_exit_phase1.start();
772 }
773
774 HandleMark hm(this);
775 Handle uncaught_exception(this, this->pending_exception());
776 this->clear_pending_exception();
777 Handle threadObj(this, this->threadObj());
778 assert(threadObj.not_null(), "Java thread object should be created");
779
780 if (!destroy_vm) {
781 if (uncaught_exception.not_null()) {
782 EXCEPTION_MARK;
783 // Call method Thread.dispatchUncaughtException().
784 Klass* thread_klass = vmClasses::Thread_klass();
785 JavaValue result(T_VOID);
786 JavaCalls::call_virtual(&result,
787 threadObj, thread_klass,
788 vmSymbols::dispatchUncaughtException_name(),
789 vmSymbols::throwable_void_signature(),
790 uncaught_exception,
791 THREAD);
792 if (HAS_PENDING_EXCEPTION) {
793 ResourceMark rm(this);
794 jio_fprintf(defaultStream::error_stream(),
795 "\nException: %s thrown from the UncaughtExceptionHandler"
796 " in thread \"%s\"\n",
797 pending_exception()->klass()->external_name(),
798 name());
799 CLEAR_PENDING_EXCEPTION;
800 }
801 }
802
803 if (!is_Compiler_thread()) {
804 // We have finished executing user-defined Java code and now have to do the
805 // implementation specific clean-up by calling Thread.exit(). We prevent any
806 // asynchronous exceptions from being delivered while in Thread.exit()
807 // to ensure the clean-up is not corrupted.
808 NoAsyncExceptionDeliveryMark _no_async(this);
809
810 EXCEPTION_MARK;
811 JavaValue result(T_VOID);
812 Klass* thread_klass = vmClasses::Thread_klass();
813 JavaCalls::call_virtual(&result,
814 threadObj, thread_klass,
815 vmSymbols::exit_method_name(),
816 vmSymbols::void_method_signature(),
817 THREAD);
818 CLEAR_PENDING_EXCEPTION;
819 }
820
821 // notify JVMTI
822 if (JvmtiExport::should_post_thread_life()) {
823 JvmtiExport::post_thread_end(this);
824 }
825 } else {
826 // before_exit() has already posted JVMTI THREAD_END events
827 }
828
829 // Cleanup any pending async exception now since we cannot access oops after
830 // BarrierSet::barrier_set()->on_thread_detach() has been executed.
831 if (has_async_exception_condition()) {
832 handshake_state()->clean_async_exception_operation();
833 }
834
835 // The careful dance between thread suspension and exit is handled here.
836 // Since we are in thread_in_vm state and suspension is done with handshakes,
837 // we can just put in the exiting state and it will be correctly handled.
838 // Also, no more async exceptions will be added to the queue after this point.
839 set_terminated(_thread_exiting);
840 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
841
842 if (log_is_enabled(Debug, os, thread, timer)) {
843 _timer_exit_phase1.stop();
844 _timer_exit_phase2.start();
845 }
846
847 // Capture daemon status before the thread is marked as terminated.
848 bool daemon = is_daemon(threadObj());
849
850 // Notify waiters on thread object. This has to be done after exit() is called
851 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
852 // group should have the destroyed bit set before waiters are notified).
853 ensure_join(this);
854 assert(!this->has_pending_exception(), "ensure_join should have cleared");
855
856 if (log_is_enabled(Debug, os, thread, timer)) {
857 _timer_exit_phase2.stop();
858 _timer_exit_phase3.start();
859 }
860 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
861 // held by this thread must be released. The spec does not distinguish
862 // between JNI-acquired and regular Java monitors. We can only see
863 // regular Java monitors here if monitor enter-exit matching is broken.
864 //
865 // ensure_join() ignores IllegalThreadStateExceptions, and so does
866 // ObjectSynchronizer::release_monitors_owned_by_thread().
867 if (exit_type == jni_detach) {
868 // Sanity check even though JNI DetachCurrentThread() would have
869 // returned JNI_ERR if there was a Java frame. JavaThread exit
870 // should be done executing Java code by the time we get here.
871 assert(!this->has_last_Java_frame(),
872 "should not have a Java frame when detaching or exiting");
873 ObjectSynchronizer::release_monitors_owned_by_thread(this);
874 assert(!this->has_pending_exception(), "release_monitors should have cleared");
875 }
876
877 // Since above code may not release JNI monitors and if someone forgot to do an
878 // JNI monitorexit, held count should be equal jni count.
879 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach).
880 assert(held_monitor_count() == jni_monitor_count(),
881 "held monitor count should be equal to jni: " INTX_FORMAT " != " INTX_FORMAT,
882 held_monitor_count(), jni_monitor_count());
883 if (CheckJNICalls && jni_monitor_count() > 0) {
884 // We would like a fatal here, but due to we never checked this before there
885 // is a lot of tests which breaks, even with an error log.
886 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.",
887 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id());
888 }
889
890 // These things needs to be done while we are still a Java Thread. Make sure that thread
891 // is in a consistent state, in case GC happens
892 JFR_ONLY(Jfr::on_thread_exit(this);)
893
894 if (active_handles() != nullptr) {
895 JNIHandleBlock* block = active_handles();
896 set_active_handles(nullptr);
897 JNIHandleBlock::release_block(block);
898 }
899
900 if (free_handle_block() != nullptr) {
901 JNIHandleBlock* block = free_handle_block();
902 set_free_handle_block(nullptr);
903 JNIHandleBlock::release_block(block);
904 }
905
906 // These have to be removed while this is still a valid thread.
907 _stack_overflow_state.remove_stack_guard_pages();
908
909 if (UseTLAB) {
910 tlab().retire();
911 }
912
913 if (JvmtiEnv::environments_might_exist()) {
914 JvmtiExport::cleanup_thread(this);
915 }
916
917 // We need to cache the thread name for logging purposes below as once
918 // we have called on_thread_detach this thread must not access any oops.
919 char* thread_name = nullptr;
920 if (log_is_enabled(Debug, os, thread, timer)) {
921 ResourceMark rm(this);
922 thread_name = os::strdup(name());
923 }
924
925 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
926 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
927 os::current_thread_id());
928
929 if (log_is_enabled(Debug, os, thread, timer)) {
930 _timer_exit_phase3.stop();
931 _timer_exit_phase4.start();
932 }
933
934 #if INCLUDE_JVMCI
935 if (JVMCICounterSize > 0) {
936 if (jvmci_counters_include(this)) {
937 for (int i = 0; i < JVMCICounterSize; i++) {
938 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
939 }
940 }
941 }
942 #endif // INCLUDE_JVMCI
943
944 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
945 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
946 Threads::remove(this, daemon);
947
948 if (log_is_enabled(Debug, os, thread, timer)) {
949 _timer_exit_phase4.stop();
950 log_debug(os, thread, timer)("name='%s'"
951 ", exit-phase1=" JLONG_FORMAT
952 ", exit-phase2=" JLONG_FORMAT
953 ", exit-phase3=" JLONG_FORMAT
954 ", exit-phase4=" JLONG_FORMAT,
955 thread_name,
956 _timer_exit_phase1.milliseconds(),
957 _timer_exit_phase2.milliseconds(),
958 _timer_exit_phase3.milliseconds(),
959 _timer_exit_phase4.milliseconds());
960 os::free(thread_name);
961 }
962 }
963
964 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
965 if (active_handles() != nullptr) {
966 JNIHandleBlock* block = active_handles();
967 set_active_handles(nullptr);
968 JNIHandleBlock::release_block(block);
969 }
970
971 if (free_handle_block() != nullptr) {
972 JNIHandleBlock* block = free_handle_block();
973 set_free_handle_block(nullptr);
974 JNIHandleBlock::release_block(block);
975 }
976
977 // These have to be removed while this is still a valid thread.
978 _stack_overflow_state.remove_stack_guard_pages();
979
980 if (UseTLAB) {
981 tlab().retire();
982 }
983
984 Threads::remove(this, is_daemon);
985 this->smr_delete();
986 }
987
988 JavaThread* JavaThread::active() {
989 Thread* thread = Thread::current();
990 if (thread->is_Java_thread()) {
991 return JavaThread::cast(thread);
992 } else {
993 assert(thread->is_VM_thread(), "this must be a vm thread");
994 VM_Operation* op = ((VMThread*) thread)->vm_operation();
995 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread());
996 return ret;
997 }
998 }
999
1000 bool JavaThread::is_lock_owned(address adr) const {
1001 assert(LockingMode != LM_LIGHTWEIGHT, "should not be called with new lightweight locking");
1002 if (Thread::is_lock_owned(adr)) return true;
1003
1004 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1005 if (chunk->contains(adr)) return true;
1006 }
1007
1008 return false;
1009 }
1010
1011 oop JavaThread::exception_oop() const {
1012 return Atomic::load(&_exception_oop);
1013 }
1014
1015 void JavaThread::set_exception_oop(oop o) {
1016 Atomic::store(&_exception_oop, o);
1017 }
1018
1019 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1020 chunk->set_next(monitor_chunks());
1021 set_monitor_chunks(chunk);
1022 }
1023
1024 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1025 guarantee(monitor_chunks() != nullptr, "must be non empty");
1026 if (monitor_chunks() == chunk) {
1027 set_monitor_chunks(chunk->next());
1028 } else {
1029 MonitorChunk* prev = monitor_chunks();
1030 while (prev->next() != chunk) prev = prev->next();
1031 prev->set_next(chunk->next());
1032 }
1033 }
1034
1035 void JavaThread::handle_special_runtime_exit_condition() {
1036 if (is_obj_deopt_suspend()) {
1037 frame_anchor()->make_walkable();
1038 wait_for_object_deoptimization();
1039 }
1040 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1041 }
1042
1043
1044 // Asynchronous exceptions support
1045 //
1046 void JavaThread::handle_async_exception(oop java_throwable) {
1047 assert(java_throwable != nullptr, "should have an _async_exception to throw");
1048 assert(!is_at_poll_safepoint(), "should have never called this method");
1049
1050 if (has_last_Java_frame()) {
1051 frame f = last_frame();
1052 if (f.is_runtime_frame()) {
1053 // If the topmost frame is a runtime stub, then we are calling into
1054 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1055 // must deoptimize the caller before continuing, as the compiled exception
1056 // handler table may not be valid.
1057 RegisterMap reg_map(this,
1058 RegisterMap::UpdateMap::skip,
1059 RegisterMap::ProcessFrames::include,
1060 RegisterMap::WalkContinuation::skip);
1061 frame compiled_frame = f.sender(®_map);
1062 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1063 Deoptimization::deoptimize(this, compiled_frame);
1064 }
1065 }
1066 }
1067
1068 // We cannot call Exceptions::_throw(...) here because we cannot block
1069 set_pending_exception(java_throwable, __FILE__, __LINE__);
1070
1071 clear_scopedValueBindings();
1072
1073 LogTarget(Info, exceptions) lt;
1074 if (lt.is_enabled()) {
1075 ResourceMark rm;
1076 LogStream ls(lt);
1077 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1078 if (has_last_Java_frame()) {
1079 frame f = last_frame();
1080 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1081 }
1082 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1083 }
1084 }
1085
1086 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1087 // Do not throw asynchronous exceptions against the compiler thread
1088 // or if the thread is already exiting.
1089 if (!can_call_java() || is_exiting()) {
1090 delete aeh;
1091 return;
1092 }
1093
1094 oop exception = aeh->exception();
1095 Handshake::execute(aeh, this); // Install asynchronous handshake
1096
1097 ResourceMark rm;
1098 if (log_is_enabled(Info, exceptions)) {
1099 log_info(exceptions)("Pending Async. exception installed of type: %s",
1100 InstanceKlass::cast(exception->klass())->external_name());
1101 }
1102 // for AbortVMOnException flag
1103 Exceptions::debug_check_abort(exception->klass()->external_name());
1104
1105 oop vt_oop = vthread();
1106 if (vt_oop == nullptr || !vt_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1107 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1108 java_lang_Thread::set_interrupted(threadObj(), true);
1109 this->interrupt();
1110 }
1111 }
1112
1113 class InstallAsyncExceptionHandshake : public HandshakeClosure {
1114 AsyncExceptionHandshake* _aeh;
1115 public:
1116 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1117 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1118 ~InstallAsyncExceptionHandshake() {
1119 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh.
1120 delete _aeh;
1121 }
1122 void do_thread(Thread* thr) {
1123 JavaThread* target = JavaThread::cast(thr);
1124 target->install_async_exception(_aeh);
1125 _aeh = nullptr;
1126 }
1127 };
1128
1129 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1130 OopHandle e(Universe::vm_global(), java_throwable);
1131 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1132 Handshake::execute(&iaeh, target);
1133 }
1134
1135 #if INCLUDE_JVMTI
1136 void JavaThread::set_is_in_VTMS_transition(bool val) {
1137 _is_in_VTMS_transition = val;
1138 }
1139
1140 #ifdef ASSERT
1141 void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1142 _is_VTMS_transition_disabler = val;
1143 }
1144 #endif
1145 #endif
1146
1147 // External suspension mechanism.
1148 //
1149 // Guarantees on return (for a valid target thread):
1150 // - Target thread will not execute any new bytecode.
1151 // - Target thread will not enter any new monitors.
1152 //
1153 bool JavaThread::java_suspend() {
1154 #if INCLUDE_JVMTI
1155 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1156 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1157 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1158 #endif
1159
1160 guarantee(Thread::is_JavaThread_protected(/* target */ this),
1161 "target JavaThread is not protected in calling context.");
1162 return this->handshake_state()->suspend();
1163 }
1164
1165 bool JavaThread::java_resume() {
1166 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1167 "missing ThreadsListHandle in calling context.");
1168 return this->handshake_state()->resume();
1169 }
1170
1171 // Wait for another thread to perform object reallocation and relocking on behalf of
1172 // this thread. The current thread is required to change to _thread_blocked in order
1173 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1174 // handshake safe, the other thread can complete the handshake used to synchronize
1175 // with this thread and then perform the reallocation and relocking.
1176 // See EscapeBarrier::sync_and_suspend_*()
1177
1178 void JavaThread::wait_for_object_deoptimization() {
1179 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1180 assert(this == Thread::current(), "invariant");
1181
1182 bool spin_wait = os::is_MP();
1183 do {
1184 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1185 // Wait for object deoptimization if requested.
1186 if (spin_wait) {
1187 // A single deoptimization is typically very short. Microbenchmarks
1188 // showed 5% better performance when spinning.
1189 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1190 SpinYield spin(spin_limit);
1191 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1192 spin.wait();
1193 }
1194 // Spin just once
1195 spin_wait = false;
1196 } else {
1197 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1198 if (is_obj_deopt_suspend()) {
1199 ml.wait();
1200 }
1201 }
1202 // A handshake for obj. deoptimization suspend could have been processed so
1203 // we must check after processing.
1204 } while (is_obj_deopt_suspend());
1205 }
1206
1207 #ifdef ASSERT
1208 // Verify the JavaThread has not yet been published in the Threads::list, and
1209 // hence doesn't need protection from concurrent access at this stage.
1210 void JavaThread::verify_not_published() {
1211 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1212 // since an unpublished JavaThread doesn't participate in the
1213 // Thread-SMR protocol for keeping a ThreadsList alive.
1214 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1215 }
1216 #endif
1217
1218 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1219 // pending, when _suspend_flags is non-zero or when we need to process a stack
1220 // watermark. Also check for pending async exceptions (except unsafe access error).
1221 // Note only the native==>Java barriers can call this function when thread state
1222 // is _thread_in_native_trans.
1223 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1224 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1225 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1226
1227 thread->set_thread_state(_thread_in_vm);
1228
1229 // Enable WXWrite: called directly from interpreter native wrapper.
1230 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1231
1232 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1233
1234 // After returning from native, it could be that the stack frames are not
1235 // yet safe to use. We catch such situations in the subsequent stack watermark
1236 // barrier, which will trap unsafe stack frames.
1237 StackWatermarkSet::before_unwind(thread);
1238 }
1239
1240 #ifndef PRODUCT
1241 // Deoptimization
1242 // Function for testing deoptimization
1243 void JavaThread::deoptimize() {
1244 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1245 bool deopt = false; // Dump stack only if a deopt actually happens.
1246 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1247 // Iterate over all frames in the thread and deoptimize
1248 for (; !fst.is_done(); fst.next()) {
1249 if (fst.current()->can_be_deoptimized()) {
1250
1251 if (only_at) {
1252 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1253 // consists of comma or carriage return separated numbers so
1254 // search for the current bci in that string.
1255 address pc = fst.current()->pc();
1256 nmethod* nm = (nmethod*) fst.current()->cb();
1257 ScopeDesc* sd = nm->scope_desc_at(pc);
1258 char buffer[8];
1259 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1260 size_t len = strlen(buffer);
1261 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1262 while (found != nullptr) {
1263 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1264 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1265 // Check that the bci found is bracketed by terminators.
1266 break;
1267 }
1268 found = strstr(found + 1, buffer);
1269 }
1270 if (!found) {
1271 continue;
1272 }
1273 }
1274
1275 if (DebugDeoptimization && !deopt) {
1276 deopt = true; // One-time only print before deopt
1277 tty->print_cr("[BEFORE Deoptimization]");
1278 trace_frames();
1279 trace_stack();
1280 }
1281 Deoptimization::deoptimize(this, *fst.current());
1282 }
1283 }
1284
1285 if (DebugDeoptimization && deopt) {
1286 tty->print_cr("[AFTER Deoptimization]");
1287 trace_frames();
1288 }
1289 }
1290
1291
1292 // Make zombies
1293 void JavaThread::make_zombies() {
1294 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1295 if (fst.current()->can_be_deoptimized()) {
1296 // it is a Java nmethod
1297 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1298 nm->make_not_entrant();
1299 }
1300 }
1301 }
1302 #endif // PRODUCT
1303
1304
1305 void JavaThread::deoptimize_marked_methods() {
1306 if (!has_last_Java_frame()) return;
1307 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1308 for (; !fst.is_done(); fst.next()) {
1309 if (fst.current()->should_be_deoptimized()) {
1310 Deoptimization::deoptimize(this, *fst.current());
1311 }
1312 }
1313 }
1314
1315 #ifdef ASSERT
1316 void JavaThread::verify_frame_info() {
1317 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1318 (has_last_Java_frame() && java_call_counter() > 0),
1319 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1320 has_last_Java_frame() ? "true" : "false", java_call_counter());
1321 }
1322 #endif
1323
1324 // Push on a new block of JNI handles.
1325 void JavaThread::push_jni_handle_block() {
1326 // Allocate a new block for JNI handles.
1327 // Inlined code from jni_PushLocalFrame()
1328 JNIHandleBlock* old_handles = active_handles();
1329 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1330 assert(old_handles != nullptr && new_handles != nullptr, "should not be null");
1331 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1332 set_active_handles(new_handles);
1333 }
1334
1335 // Pop off the current block of JNI handles.
1336 void JavaThread::pop_jni_handle_block() {
1337 // Release our JNI handle block
1338 JNIHandleBlock* old_handles = active_handles();
1339 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1340 assert(new_handles != nullptr, "should never set active handles to null");
1341 set_active_handles(new_handles);
1342 old_handles->set_pop_frame_link(nullptr);
1343 JNIHandleBlock::release_block(old_handles, this);
1344 }
1345
1346 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1347 // Verify that the deferred card marks have been flushed.
1348 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1349
1350 // Traverse the GCHandles
1351 Thread::oops_do_no_frames(f, cf);
1352
1353 if (active_handles() != nullptr) {
1354 active_handles()->oops_do(f);
1355 }
1356
1357 DEBUG_ONLY(verify_frame_info();)
1358
1359 if (has_last_Java_frame()) {
1360 // Traverse the monitor chunks
1361 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1362 chunk->oops_do(f);
1363 }
1364 }
1365
1366 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!");
1367 // If we have deferred set_locals there might be oops waiting to be
1368 // written
1369 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1370 if (list != nullptr) {
1371 for (int i = 0; i < list->length(); i++) {
1372 list->at(i)->oops_do(f);
1373 }
1374 }
1375
1376 // Traverse instance variables at the end since the GC may be moving things
1377 // around using this function
1378 f->do_oop((oop*) &_vm_result);
1379 f->do_oop((oop*) &_exception_oop);
1380 #if INCLUDE_JVMCI
1381 f->do_oop((oop*) &_jvmci_reserved_oop0);
1382 #endif
1383
1384 if (jvmti_thread_state() != nullptr) {
1385 jvmti_thread_state()->oops_do(f, cf);
1386 }
1387
1388 // The continuation oops are really on the stack. But there is typically at most
1389 // one of those per thread, so we handle them here in the oops_do_no_frames part
1390 // so that we don't have to sprinkle as many stack watermark checks where these
1391 // oops are used. We just need to make sure the thread has started processing.
1392 ContinuationEntry* entry = _cont_entry;
1393 while (entry != nullptr) {
1394 f->do_oop((oop*)entry->cont_addr());
1395 f->do_oop((oop*)entry->chunk_addr());
1396 entry = entry->parent();
1397 }
1398
1399 if (LockingMode == LM_LIGHTWEIGHT) {
1400 lock_stack().oops_do(f);
1401 }
1402 }
1403
1404 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
1405 if (!has_last_Java_frame()) {
1406 return;
1407 }
1408 // Finish any pending lazy GC activity for the frames
1409 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc);
1410 // Traverse the execution stack
1411 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1412 fst.current()->oops_do(f, cf, fst.register_map());
1413 }
1414 }
1415
1416 #ifdef ASSERT
1417 void JavaThread::verify_states_for_handshake() {
1418 // This checks that the thread has a correct frame state during a handshake.
1419 verify_frame_info();
1420 }
1421 #endif
1422
1423 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1424 DEBUG_ONLY(verify_frame_info();)
1425 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1426
1427 if (has_last_Java_frame()) {
1428 // Traverse the execution stack
1429 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1430 fst.current()->nmethods_do(cf);
1431 }
1432 }
1433
1434 if (jvmti_thread_state() != nullptr) {
1435 jvmti_thread_state()->nmethods_do(cf);
1436 }
1437 }
1438
1439 void JavaThread::metadata_do(MetadataClosure* f) {
1440 if (has_last_Java_frame()) {
1441 // Traverse the execution stack to call f() on the methods in the stack
1442 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1443 fst.current()->metadata_do(f);
1444 }
1445 } else if (is_Compiler_thread()) {
1446 // need to walk ciMetadata in current compile tasks to keep alive.
1447 CompilerThread* ct = (CompilerThread*)this;
1448 if (ct->env() != nullptr) {
1449 ct->env()->metadata_do(f);
1450 }
1451 CompileTask* task = ct->task();
1452 if (task != nullptr) {
1453 task->metadata_do(f);
1454 }
1455 }
1456 }
1457
1458 // Printing
1459 static const char* _get_thread_state_name(JavaThreadState _thread_state) {
1460 switch (_thread_state) {
1461 case _thread_uninitialized: return "_thread_uninitialized";
1462 case _thread_new: return "_thread_new";
1463 case _thread_new_trans: return "_thread_new_trans";
1464 case _thread_in_native: return "_thread_in_native";
1465 case _thread_in_native_trans: return "_thread_in_native_trans";
1466 case _thread_in_vm: return "_thread_in_vm";
1467 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1468 case _thread_in_Java: return "_thread_in_Java";
1469 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1470 case _thread_blocked: return "_thread_blocked";
1471 case _thread_blocked_trans: return "_thread_blocked_trans";
1472 default: return "unknown thread state";
1473 }
1474 }
1475
1476 void JavaThread::print_thread_state_on(outputStream *st) const {
1477 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1478 }
1479
1480 // Called by Threads::print() for VM_PrintThreads operation
1481 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1482 st->print_raw("\"");
1483 st->print_raw(name());
1484 st->print_raw("\" ");
1485 oop thread_oop = threadObj();
1486 if (thread_oop != nullptr) {
1487 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1488 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1489 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1490 }
1491 Thread::print_on(st, print_extended_info);
1492 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1493 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1494 if (thread_oop != nullptr) {
1495 if (is_vthread_mounted()) {
1496 oop vt = vthread();
1497 assert(vt != nullptr, "");
1498 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1499 } else {
1500 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1501 }
1502 }
1503 #ifndef PRODUCT
1504 _safepoint_state->print_on(st);
1505 #endif // PRODUCT
1506 if (is_Compiler_thread()) {
1507 CompileTask *task = ((CompilerThread*)this)->task();
1508 if (task != nullptr) {
1509 st->print(" Compiling: ");
1510 task->print(st, nullptr, true, false);
1511 } else {
1512 st->print(" No compile task");
1513 }
1514 st->cr();
1515 }
1516 }
1517
1518 void JavaThread::print() const { print_on(tty); }
1519
1520 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1521 st->print("%s", get_thread_name_string(buf, buflen));
1522 }
1523
1524 // Called by fatal error handler. The difference between this and
1525 // JavaThread::print() is that we can't grab lock or allocate memory.
1526 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1527 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1528 Thread* current = Thread::current_or_null_safe();
1529 assert(current != nullptr, "cannot be called by a detached thread");
1530 st->fill_to(60);
1531 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1532 // Only access threadObj() if current thread is not a JavaThread
1533 // or if it is a JavaThread that can safely access oops.
1534 oop thread_obj = threadObj();
1535 if (thread_obj != nullptr) {
1536 st->print(java_lang_Thread::is_daemon(thread_obj) ? " daemon" : " ");
1537 }
1538 }
1539 st->print(" [");
1540 st->print("%s", _get_thread_state_name(_thread_state));
1541 if (osthread()) {
1542 st->print(", id=%d", osthread()->thread_id());
1543 }
1544 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ") (" PROPERFMT ")",
1545 p2i(stack_end()), p2i(stack_base()),
1546 PROPERFMTARGS(stack_size()));
1547 st->print("]");
1548
1549 ThreadsSMRSupport::print_info_on(this, st);
1550 return;
1551 }
1552
1553
1554 // Verification
1555
1556 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1557 // ignore if there is no stack
1558 if (!has_last_Java_frame()) return;
1559 // traverse the stack frames. Starts from top frame.
1560 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1561 frame* fr = fst.current();
1562 f(fr, fst.register_map());
1563 }
1564 }
1565
1566 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1567
1568 void JavaThread::verify() {
1569 // Verify oops in the thread.
1570 oops_do(&VerifyOopClosure::verify_oop, nullptr);
1571
1572 // Verify the stack frames.
1573 frames_do(frame_verify);
1574 }
1575
1576 // CR 6300358 (sub-CR 2137150)
1577 // Most callers of this method assume that it can't return null but a
1578 // thread may not have a name whilst it is in the process of attaching to
1579 // the VM - see CR 6412693, and there are places where a JavaThread can be
1580 // seen prior to having its threadObj set (e.g., JNI attaching threads and
1581 // if vm exit occurs during initialization). These cases can all be accounted
1582 // for such that this method never returns null.
1583 const char* JavaThread::name() const {
1584 if (Thread::is_JavaThread_protected(/* target */ this)) {
1585 // The target JavaThread is protected so get_thread_name_string() is safe:
1586 return get_thread_name_string();
1587 }
1588
1589 // The target JavaThread is not protected so we return the default:
1590 return Thread::name();
1591 }
1592
1593 // Like name() but doesn't include the protection check. This must only be
1594 // called when it is known to be safe, even though the protection check can't tell
1595 // that e.g. when this thread is the init_thread() - see instanceKlass.cpp.
1596 const char* JavaThread::name_raw() const {
1597 return get_thread_name_string();
1598 }
1599
1600 // Returns a non-null representation of this thread's name, or a suitable
1601 // descriptive string if there is no set name.
1602 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1603 const char* name_str;
1604 #ifdef ASSERT
1605 Thread* current = Thread::current_or_null_safe();
1606 assert(current != nullptr, "cannot be called by a detached thread");
1607 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1608 // Only access threadObj() if current thread is not a JavaThread
1609 // or if it is a JavaThread that can safely access oops.
1610 #endif
1611 oop thread_obj = threadObj();
1612 if (thread_obj != nullptr) {
1613 oop name = java_lang_Thread::name(thread_obj);
1614 if (name != nullptr) {
1615 if (buf == nullptr) {
1616 name_str = java_lang_String::as_utf8_string(name);
1617 } else {
1618 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1619 }
1620 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1621 name_str = "<no-name - thread is attaching>";
1622 } else {
1623 name_str = "<un-named>";
1624 }
1625 } else {
1626 name_str = Thread::name();
1627 }
1628 #ifdef ASSERT
1629 } else {
1630 // Current JavaThread has exited...
1631 if (current == this) {
1632 // ... and is asking about itself:
1633 name_str = "<no-name - current JavaThread has exited>";
1634 } else {
1635 // ... and it can't safely determine this JavaThread's name so
1636 // use the default thread name.
1637 name_str = Thread::name();
1638 }
1639 }
1640 #endif
1641 assert(name_str != nullptr, "unexpected null thread name");
1642 return name_str;
1643 }
1644
1645 // Helper to extract the name from the thread oop for logging.
1646 const char* JavaThread::name_for(oop thread_obj) {
1647 assert(thread_obj != nullptr, "precondition");
1648 oop name = java_lang_Thread::name(thread_obj);
1649 const char* name_str;
1650 if (name != nullptr) {
1651 name_str = java_lang_String::as_utf8_string(name);
1652 } else {
1653 name_str = "<un-named>";
1654 }
1655 return name_str;
1656 }
1657
1658 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1659
1660 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1661 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1662 // Link Java Thread object <-> C++ Thread
1663
1664 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1665 // and put it into a new Handle. The Handle "thread_oop" can then
1666 // be used to pass the C++ thread object to other methods.
1667
1668 // Set the Java level thread object (jthread) field of the
1669 // new thread (a JavaThread *) to C++ thread object using the
1670 // "thread_oop" handle.
1671
1672 // Set the thread field (a JavaThread *) of the
1673 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1674
1675 Handle thread_oop(Thread::current(),
1676 JNIHandles::resolve_non_null(jni_thread));
1677 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1678 "must be initialized");
1679 set_threadOopHandles(thread_oop());
1680
1681 if (prio == NoPriority) {
1682 prio = java_lang_Thread::priority(thread_oop());
1683 assert(prio != NoPriority, "A valid priority should be present");
1684 }
1685
1686 // Push the Java priority down to the native thread; needs Threads_lock
1687 Thread::set_priority(this, prio);
1688
1689 // Add the new thread to the Threads list and set it in motion.
1690 // We must have threads lock in order to call Threads::add.
1691 // It is crucial that we do not block before the thread is
1692 // added to the Threads list for if a GC happens, then the java_thread oop
1693 // will not be visited by GC.
1694 Threads::add(this);
1695 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
1696 // on a ThreadsList. We don't want to wait for the release when the
1697 // Theads_lock is dropped somewhere in the caller since the JavaThread*
1698 // is already visible to JVM/TI via the ThreadsList.
1699 java_lang_Thread::release_set_thread(thread_oop(), this);
1700 }
1701
1702 oop JavaThread::current_park_blocker() {
1703 // Support for JSR-166 locks
1704 oop thread_oop = threadObj();
1705 if (thread_oop != nullptr) {
1706 return java_lang_Thread::park_blocker(thread_oop);
1707 }
1708 return nullptr;
1709 }
1710
1711 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1712 // This is the external format, selecting the platform or vthread
1713 // as applicable, and allowing for a native-only stack.
1714 void JavaThread::print_jni_stack() {
1715 assert(this == JavaThread::current(), "Can't print stack of other threads");
1716 if (!has_last_Java_frame()) {
1717 ResourceMark rm(this);
1718 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
1719 if (buf == nullptr) {
1720 tty->print_cr("Unable to print native stack - out of memory");
1721 return;
1722 }
1723 address lastpc = nullptr;
1724 if (os::platform_print_native_stack(tty, nullptr, buf, O_BUFLEN, lastpc)) {
1725 // We have printed the native stack in platform-specific code,
1726 // so nothing else to do in this case.
1727 } else {
1728 frame f = os::current_frame();
1729 VMError::print_native_stack(tty, f, this, true /*print_source_info */,
1730 -1 /* max stack */, buf, O_BUFLEN);
1731 }
1732 } else {
1733 print_active_stack_on(tty);
1734 }
1735 }
1736
1737 void JavaThread::print_stack_on(outputStream* st) {
1738 if (!has_last_Java_frame()) return;
1739
1740 Thread* current_thread = Thread::current();
1741 ResourceMark rm(current_thread);
1742 HandleMark hm(current_thread);
1743
1744 RegisterMap reg_map(this,
1745 RegisterMap::UpdateMap::include,
1746 RegisterMap::ProcessFrames::include,
1747 RegisterMap::WalkContinuation::skip);
1748 vframe* start_vf = platform_thread_last_java_vframe(®_map);
1749 int count = 0;
1750 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1751 if (f->is_java_frame()) {
1752 javaVFrame* jvf = javaVFrame::cast(f);
1753 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1754
1755 // Print out lock information
1756 if (JavaMonitorsInStackTrace) {
1757 jvf->print_lock_info_on(st, count);
1758 }
1759 } else {
1760 // Ignore non-Java frames
1761 }
1762
1763 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1764 count++;
1765 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1766 }
1767 }
1768
1769 void JavaThread::print_vthread_stack_on(outputStream* st) {
1770 assert(is_vthread_mounted(), "Caller should have checked this");
1771 assert(has_last_Java_frame(), "must be");
1772
1773 Thread* current_thread = Thread::current();
1774 ResourceMark rm(current_thread);
1775 HandleMark hm(current_thread);
1776
1777 RegisterMap reg_map(this,
1778 RegisterMap::UpdateMap::include,
1779 RegisterMap::ProcessFrames::include,
1780 RegisterMap::WalkContinuation::include);
1781 ContinuationEntry* cont_entry = last_continuation();
1782 vframe* start_vf = last_java_vframe(®_map);
1783 int count = 0;
1784 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1785 // Watch for end of vthread stack
1786 if (Continuation::is_continuation_enterSpecial(f->fr())) {
1787 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), "");
1788 if (cont_entry->is_virtual_thread()) {
1789 break;
1790 }
1791 cont_entry = cont_entry->parent();
1792 }
1793 if (f->is_java_frame()) {
1794 javaVFrame* jvf = javaVFrame::cast(f);
1795 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1796
1797 // Print out lock information
1798 if (JavaMonitorsInStackTrace) {
1799 jvf->print_lock_info_on(st, count);
1800 }
1801 } else {
1802 // Ignore non-Java frames
1803 }
1804
1805 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1806 count++;
1807 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1808 }
1809 }
1810
1811 void JavaThread::print_active_stack_on(outputStream* st) {
1812 if (is_vthread_mounted()) {
1813 print_vthread_stack_on(st);
1814 } else {
1815 print_stack_on(st);
1816 }
1817 }
1818
1819 #if INCLUDE_JVMTI
1820 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1821 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1822 set_jvmti_vthread(thread_oop);
1823
1824 // unbind current JvmtiThreadState from JavaThread
1825 JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1826
1827 // bind new JvmtiThreadState to JavaThread
1828 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1829
1830 return jvmti_thread_state();
1831 }
1832 #endif
1833
1834 // JVMTI PopFrame support
1835 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1836 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments");
1837 if (in_bytes(size_in_bytes) != 0) {
1838 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1839 _popframe_preserved_args_size = in_bytes(size_in_bytes);
1840 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1841 }
1842 }
1843
1844 void* JavaThread::popframe_preserved_args() {
1845 return _popframe_preserved_args;
1846 }
1847
1848 ByteSize JavaThread::popframe_preserved_args_size() {
1849 return in_ByteSize(_popframe_preserved_args_size);
1850 }
1851
1852 WordSize JavaThread::popframe_preserved_args_size_in_words() {
1853 int sz = in_bytes(popframe_preserved_args_size());
1854 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1855 return in_WordSize(sz / wordSize);
1856 }
1857
1858 void JavaThread::popframe_free_preserved_args() {
1859 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice");
1860 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1861 _popframe_preserved_args = nullptr;
1862 _popframe_preserved_args_size = 0;
1863 }
1864
1865 #ifndef PRODUCT
1866
1867 void JavaThread::trace_frames() {
1868 tty->print_cr("[Describe stack]");
1869 int frame_no = 1;
1870 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1871 tty->print(" %d. ", frame_no++);
1872 fst.current()->print_value_on(tty, this);
1873 tty->cr();
1874 }
1875 }
1876
1877 class PrintAndVerifyOopClosure: public OopClosure {
1878 protected:
1879 template <class T> inline void do_oop_work(T* p) {
1880 oop obj = RawAccess<>::oop_load(p);
1881 if (obj == nullptr) return;
1882 tty->print(INTPTR_FORMAT ": ", p2i(p));
1883 if (oopDesc::is_oop_or_null(obj)) {
1884 if (obj->is_objArray()) {
1885 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1886 } else {
1887 obj->print();
1888 }
1889 } else {
1890 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1891 }
1892 tty->cr();
1893 }
1894 public:
1895 virtual void do_oop(oop* p) { do_oop_work(p); }
1896 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1897 };
1898
1899 #ifdef ASSERT
1900 // Print or validate the layout of stack frames
1901 void JavaThread::print_frame_layout(int depth, bool validate_only) {
1902 ResourceMark rm;
1903 PreserveExceptionMark pm(this);
1904 FrameValues values;
1905 int frame_no = 0;
1906 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1907 fst.current()->describe(values, ++frame_no, fst.register_map());
1908 if (depth == frame_no) break;
1909 }
1910 Continuation::describe(values);
1911 if (validate_only) {
1912 values.validate();
1913 } else {
1914 tty->print_cr("[Describe stack layout]");
1915 values.print(this);
1916 }
1917 }
1918 #endif
1919
1920 void JavaThread::trace_stack_from(vframe* start_vf) {
1921 ResourceMark rm;
1922 int vframe_no = 1;
1923 for (vframe* f = start_vf; f; f = f->sender()) {
1924 if (f->is_java_frame()) {
1925 javaVFrame::cast(f)->print_activation(vframe_no++);
1926 } else {
1927 f->print();
1928 }
1929 if (vframe_no > StackPrintLimit) {
1930 tty->print_cr("...<more frames>...");
1931 return;
1932 }
1933 }
1934 }
1935
1936
1937 void JavaThread::trace_stack() {
1938 if (!has_last_Java_frame()) return;
1939 Thread* current_thread = Thread::current();
1940 ResourceMark rm(current_thread);
1941 HandleMark hm(current_thread);
1942 RegisterMap reg_map(this,
1943 RegisterMap::UpdateMap::include,
1944 RegisterMap::ProcessFrames::include,
1945 RegisterMap::WalkContinuation::skip);
1946 trace_stack_from(last_java_vframe(®_map));
1947 }
1948
1949
1950 #endif // PRODUCT
1951
1952 void JavaThread::inc_held_monitor_count(intx i, bool jni) {
1953 #ifdef SUPPORT_MONITOR_COUNT
1954 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _held_monitor_count);
1955 _held_monitor_count += i;
1956 if (jni) {
1957 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _jni_monitor_count);
1958 _jni_monitor_count += i;
1959 }
1960 #endif
1961 }
1962
1963 void JavaThread::dec_held_monitor_count(intx i, bool jni) {
1964 #ifdef SUPPORT_MONITOR_COUNT
1965 _held_monitor_count -= i;
1966 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _held_monitor_count);
1967 if (jni) {
1968 _jni_monitor_count -= i;
1969 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _jni_monitor_count);
1970 }
1971 #endif
1972 }
1973
1974 frame JavaThread::vthread_last_frame() {
1975 assert (is_vthread_mounted(), "Virtual thread not mounted");
1976 return last_frame();
1977 }
1978
1979 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
1980 const ContinuationEntry* entry = vthread_continuation();
1981 guarantee (entry != nullptr, "Not a carrier thread");
1982 frame f = entry->to_frame();
1983 if (reg_map->process_frames()) {
1984 entry->flush_stack_processing(this);
1985 }
1986 entry->update_register_map(reg_map);
1987 return f.sender(reg_map);
1988 }
1989
1990 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
1991 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
1992 }
1993
1994 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
1995 assert(reg_map != nullptr, "a map must be given");
1996 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
1997 if (vf->is_java_frame()) return javaVFrame::cast(vf);
1998 }
1999 return nullptr;
2000 }
2001
2002 Klass* JavaThread::security_get_caller_class(int depth) {
2003 ResetNoHandleMark rnhm;
2004 HandleMark hm(Thread::current());
2005
2006 vframeStream vfst(this);
2007 vfst.security_get_caller_frame(depth);
2008 if (!vfst.at_end()) {
2009 return vfst.method()->method_holder();
2010 }
2011 return nullptr;
2012 }
2013
2014 // Internal convenience function for millisecond resolution sleeps.
2015 bool JavaThread::sleep(jlong millis) {
2016 jlong nanos;
2017 if (millis > max_jlong / NANOUNITS_PER_MILLIUNIT) {
2018 // Conversion to nanos would overflow, saturate at max
2019 nanos = max_jlong;
2020 } else {
2021 nanos = millis * NANOUNITS_PER_MILLIUNIT;
2022 }
2023 return sleep_nanos(nanos);
2024 }
2025
2026 // java.lang.Thread.sleep support
2027 // Returns true if sleep time elapsed as expected, and false
2028 // if the thread was interrupted.
2029 bool JavaThread::sleep_nanos(jlong nanos) {
2030 assert(this == Thread::current(), "thread consistency check");
2031 assert(nanos >= 0, "nanos are in range");
2032
2033 ParkEvent * const slp = this->_SleepEvent;
2034 // Because there can be races with thread interruption sending an unpark()
2035 // to the event, we explicitly reset it here to avoid an immediate return.
2036 // The actual interrupt state will be checked before we park().
2037 slp->reset();
2038 // Thread interruption establishes a happens-before ordering in the
2039 // Java Memory Model, so we need to ensure we synchronize with the
2040 // interrupt state.
2041 OrderAccess::fence();
2042
2043 jlong prevtime = os::javaTimeNanos();
2044
2045 jlong nanos_remaining = nanos;
2046
2047 for (;;) {
2048 // interruption has precedence over timing out
2049 if (this->is_interrupted(true)) {
2050 return false;
2051 }
2052
2053 if (nanos_remaining <= 0) {
2054 return true;
2055 }
2056
2057 {
2058 ThreadBlockInVM tbivm(this);
2059 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2060 slp->park_nanos(nanos_remaining);
2061 }
2062
2063 // Update elapsed time tracking
2064 jlong newtime = os::javaTimeNanos();
2065 if (newtime - prevtime < 0) {
2066 // time moving backwards, should only happen if no monotonic clock
2067 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2068 assert(false,
2069 "unexpected time moving backwards detected in JavaThread::sleep()");
2070 } else {
2071 nanos_remaining -= (newtime - prevtime);
2072 }
2073 prevtime = newtime;
2074 }
2075 }
2076
2077 // Last thread running calls java.lang.Shutdown.shutdown()
2078 void JavaThread::invoke_shutdown_hooks() {
2079 HandleMark hm(this);
2080
2081 // We could get here with a pending exception, if so clear it now.
2082 if (this->has_pending_exception()) {
2083 this->clear_pending_exception();
2084 }
2085
2086 EXCEPTION_MARK;
2087 Klass* shutdown_klass =
2088 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
2089 THREAD);
2090 if (shutdown_klass != nullptr) {
2091 // SystemDictionary::resolve_or_null will return null if there was
2092 // an exception. If we cannot load the Shutdown class, just don't
2093 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
2094 // won't be run. Note that if a shutdown hook was registered,
2095 // the Shutdown class would have already been loaded
2096 // (Runtime.addShutdownHook will load it).
2097 JavaValue result(T_VOID);
2098 JavaCalls::call_static(&result,
2099 shutdown_klass,
2100 vmSymbols::shutdown_name(),
2101 vmSymbols::void_method_signature(),
2102 THREAD);
2103 }
2104 CLEAR_PENDING_EXCEPTION;
2105 }
2106
2107 #ifndef PRODUCT
2108 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
2109 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
2110 }
2111 #endif
2112
2113 // Helper function to create the java.lang.Thread object for a
2114 // VM-internal thread. The thread will have the given name, and be
2115 // a member of the "system" ThreadGroup.
2116 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) {
2117 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2118
2119 // Initialize thread_oop to put it into the system threadGroup.
2120 // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2121 Handle thread_group(THREAD, Universe::system_thread_group());
2122 Handle thread_oop =
2123 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2124 vmSymbols::threadgroup_string_void_signature(),
2125 thread_group,
2126 string,
2127 CHECK_NH);
2128
2129 return thread_oop;
2130 }
2131
2132 // Starts the target JavaThread as a daemon of the given priority, and
2133 // bound to the given java.lang.Thread instance.
2134 // The Threads_lock is held for the duration.
2135 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2136 Handle thread_oop, ThreadPriority prio) {
2137
2138 assert(target->osthread() != nullptr, "target thread is not properly initialized");
2139
2140 MutexLocker mu(current, Threads_lock);
2141
2142 // Initialize the fields of the thread_oop first.
2143 if (prio != NoPriority) {
2144 java_lang_Thread::set_priority(thread_oop(), prio);
2145 // Note: we don't call os::set_priority here. Possibly we should,
2146 // else all threads should call it themselves when they first run.
2147 }
2148
2149 java_lang_Thread::set_daemon(thread_oop());
2150
2151 // Now bind the thread_oop to the target JavaThread.
2152 target->set_threadOopHandles(thread_oop());
2153
2154 Threads::add(target); // target is now visible for safepoint/handshake
2155 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
2156 // on a ThreadsList. We don't want to wait for the release when the
2157 // Theads_lock is dropped when the 'mu' destructor is run since the
2158 // JavaThread* is already visible to JVM/TI via the ThreadsList.
2159
2160 assert(java_lang_Thread::thread(thread_oop()) == nullptr, "must not be alive");
2161 java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now
2162 Thread::start(target);
2163 }
2164
2165 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2166 // At this point it may be possible that no osthread was created for the
2167 // JavaThread due to lack of resources. However, since this must work
2168 // for critical system threads just check and abort if this fails.
2169 if (thread->osthread() == nullptr) {
2170 // This isn't really an OOM condition, but historically this is what
2171 // we report.
2172 vm_exit_during_initialization("java.lang.OutOfMemoryError",
2173 os::native_thread_creation_failed_msg());
2174 }
2175 }
2176
2177 void JavaThread::pretouch_stack() {
2178 // Given an established java thread stack with usable area followed by
2179 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging
2180 // from the current frame down to the start of the shadow zone.
2181 const address end = _stack_overflow_state.shadow_zone_safe_limit();
2182 if (is_in_full_stack(end)) {
2183 char* p1 = (char*) alloca(1);
2184 address here = (address) &p1;
2185 if (is_in_full_stack(here) && here > end) {
2186 size_t to_alloc = here - end;
2187 char* p2 = (char*) alloca(to_alloc);
2188 log_trace(os, thread)("Pretouching thread stack from " PTR_FORMAT " to " PTR_FORMAT ".",
2189 p2i(p2), p2i(end));
2190 os::pretouch_memory(p2, p2 + to_alloc,
2191 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096));
2192 }
2193 }
2194 }
2195
2196 // Deferred OopHandle release support.
2197
2198 class OopHandleList : public CHeapObj<mtInternal> {
2199 static const int _count = 4;
2200 OopHandle _handles[_count];
2201 OopHandleList* _next;
2202 int _index;
2203 public:
2204 OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2205 void add(OopHandle h) {
2206 assert(_index < _count, "too many additions");
2207 _handles[_index++] = h;
2208 }
2209 ~OopHandleList() {
2210 assert(_index == _count, "usage error");
2211 for (int i = 0; i < _index; i++) {
2212 _handles[i].release(JavaThread::thread_oop_storage());
2213 }
2214 }
2215 OopHandleList* next() const { return _next; }
2216 };
2217
2218 OopHandleList* JavaThread::_oop_handle_list = nullptr;
2219
2220 // Called by the ServiceThread to do the work of releasing
2221 // the OopHandles.
2222 void JavaThread::release_oop_handles() {
2223 OopHandleList* list;
2224 {
2225 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2226 list = _oop_handle_list;
2227 _oop_handle_list = nullptr;
2228 }
2229 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2230
2231 while (list != nullptr) {
2232 OopHandleList* l = list;
2233 list = l->next();
2234 delete l;
2235 }
2236 }
2237
2238 // Add our OopHandles for later release.
2239 void JavaThread::add_oop_handles_for_release() {
2240 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2241 OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2242 new_head->add(_threadObj);
2243 new_head->add(_vthread);
2244 new_head->add(_jvmti_vthread);
2245 new_head->add(_scopedValueCache);
2246 _oop_handle_list = new_head;
2247 Service_lock->notify_all();
2248 }