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