jdk

Форк
0
/
javaThread.cpp 
2294 строки · 80.3 Кб
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
// If there is a virtual thread mounted then return vthread() oop.
193
// Otherwise, return threadObj().
194
oop JavaThread::vthread_or_thread() const {
195
  oop result = vthread();
196
  if (result == nullptr) {
197
    result = threadObj();
198
  }
199
  return result;
200
}
201

202
oop JavaThread::scopedValueCache() const {
203
  return _scopedValueCache.resolve();
204
}
205

206
void JavaThread::set_scopedValueCache(oop p) {
207
  if (!_scopedValueCache.is_empty()) { // i.e. if the OopHandle has been allocated
208
    _scopedValueCache.replace(p);
209
  } else {
210
    assert(p == nullptr, "not yet initialized");
211
  }
212
}
213

214
void JavaThread::clear_scopedValueBindings() {
215
  set_scopedValueCache(nullptr);
216
  oop vthread_oop = vthread();
217
  // vthread may be null here if we get a VM error during startup,
218
  // before the java.lang.Thread instance has been created.
219
  if (vthread_oop != nullptr) {
220
    java_lang_Thread::clear_scopedValueBindings(vthread_oop);
221
  }
222
}
223

224
void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
225
                                    bool daemon, TRAPS) {
226
  assert(thread_group.not_null(), "thread group should be specified");
227
  assert(threadObj() == nullptr, "should only create Java thread object once");
228

229
  InstanceKlass* ik = vmClasses::Thread_klass();
230
  assert(ik->is_initialized(), "must be");
231
  instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
232

233
  // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
234
  // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
235
  // constructor calls Thread.current(), which must be set here.
236
  java_lang_Thread::set_thread(thread_oop(), this);
237
  set_threadOopHandles(thread_oop());
238

239
  JavaValue result(T_VOID);
240
  if (thread_name != nullptr) {
241
    Handle name = java_lang_String::create_from_str(thread_name, CHECK);
242
    // Thread gets assigned specified name and null target
243
    JavaCalls::call_special(&result,
244
                            thread_oop,
245
                            ik,
246
                            vmSymbols::object_initializer_name(),
247
                            vmSymbols::threadgroup_string_void_signature(),
248
                            thread_group,
249
                            name,
250
                            CHECK);
251
  } else {
252
    // Thread gets assigned name "Thread-nnn" and null target
253
    // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
254
    JavaCalls::call_special(&result,
255
                            thread_oop,
256
                            ik,
257
                            vmSymbols::object_initializer_name(),
258
                            vmSymbols::threadgroup_runnable_void_signature(),
259
                            thread_group,
260
                            Handle(),
261
                            CHECK);
262
  }
263
  os::set_priority(this, NormPriority);
264

265
  if (daemon) {
266
    java_lang_Thread::set_daemon(thread_oop());
267
  }
268
}
269

270
// ======= JavaThread ========
271

272
#if INCLUDE_JVMCI
273

274
jlong* JavaThread::_jvmci_old_thread_counters;
275

276
static bool jvmci_counters_include(JavaThread* thread) {
277
  return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
278
}
279

280
void JavaThread::collect_counters(jlong* array, int length) {
281
  assert(length == JVMCICounterSize, "wrong value");
282
  for (int i = 0; i < length; i++) {
283
    array[i] = _jvmci_old_thread_counters[i];
284
  }
285
  for (JavaThread* tp : ThreadsListHandle()) {
286
    if (jvmci_counters_include(tp)) {
287
      for (int i = 0; i < length; i++) {
288
        array[i] += tp->_jvmci_counters[i];
289
      }
290
    }
291
  }
292
}
293

294
// Attempt to enlarge the array for per thread counters.
295
static jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
296
  jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
297
  if (new_counters == nullptr) {
298
    return nullptr;
299
  }
300
  if (old_counters == nullptr) {
301
    old_counters = new_counters;
302
    memset(old_counters, 0, sizeof(jlong) * new_size);
303
  } else {
304
    for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
305
      new_counters[i] = old_counters[i];
306
    }
307
    if (new_size > current_size) {
308
      memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
309
    }
310
    FREE_C_HEAP_ARRAY(jlong, old_counters);
311
  }
312
  return new_counters;
313
}
314

315
// Attempt to enlarge the array for per thread counters.
316
bool JavaThread::resize_counters(int current_size, int new_size) {
317
  jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
318
  if (new_counters == nullptr) {
319
    return false;
320
  } else {
321
    _jvmci_counters = new_counters;
322
    return true;
323
  }
324
}
325

326
class VM_JVMCIResizeCounters : public VM_Operation {
327
 private:
328
  int _new_size;
329
  bool _failed;
330

331
 public:
332
  VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
333
  VMOp_Type type()                  const        { return VMOp_JVMCIResizeCounters; }
334
  bool allow_nested_vm_operations() const        { return true; }
335
  void doit() {
336
    // Resize the old thread counters array
337
    jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
338
    if (new_counters == nullptr) {
339
      _failed = true;
340
      return;
341
    } else {
342
      JavaThread::_jvmci_old_thread_counters = new_counters;
343
    }
344

345
    // Now resize each threads array
346
    for (JavaThread* tp : ThreadsListHandle()) {
347
      if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
348
        _failed = true;
349
        break;
350
      }
351
    }
352
    if (!_failed) {
353
      JVMCICounterSize = _new_size;
354
    }
355
  }
356

357
  bool failed() { return _failed; }
358
};
359

360
bool JavaThread::resize_all_jvmci_counters(int new_size) {
361
  VM_JVMCIResizeCounters op(new_size);
362
  VMThread::execute(&op);
363
  return !op.failed();
364
}
365

366
#endif // INCLUDE_JVMCI
367

368
#ifdef ASSERT
369
// Checks safepoint allowed and clears unhandled oops at potential safepoints.
370
void JavaThread::check_possible_safepoint() {
371
  if (_no_safepoint_count > 0) {
372
    print_owned_locks();
373
    assert(false, "Possible safepoint reached by thread that does not allow it");
374
  }
375
#ifdef CHECK_UNHANDLED_OOPS
376
  // Clear unhandled oops in JavaThreads so we get a crash right away.
377
  clear_unhandled_oops();
378
#endif // CHECK_UNHANDLED_OOPS
379

380
  // Macos/aarch64 should be in the right state for safepoint (e.g.
381
  // deoptimization needs WXWrite).  Crashes caused by the wrong state rarely
382
  // happens in practice, making such issues hard to find and reproduce.
383
#if defined(__APPLE__) && defined(AARCH64)
384
  if (AssertWXAtThreadSync) {
385
    assert_wx_state(WXWrite);
386
  }
387
#endif
388
}
389

390
void JavaThread::check_for_valid_safepoint_state() {
391
  // Don't complain if running a debugging command.
392
  if (DebuggingContext::is_enabled()) return;
393

394
  // Check NoSafepointVerifier, which is implied by locks taken that can be
395
  // shared with the VM thread.  This makes sure that no locks with allow_vm_block
396
  // are held.
397
  check_possible_safepoint();
398

399
  if (thread_state() != _thread_in_vm) {
400
    fatal("LEAF method calling lock?");
401
  }
402

403
  if (GCALotAtAllSafepoints) {
404
    // We could enter a safepoint here and thus have a gc
405
    InterfaceSupport::check_gc_alot();
406
  }
407
}
408
#endif // ASSERT
409

410
// A JavaThread is a normal Java thread
411

412
JavaThread::JavaThread(MEMFLAGS flags) :
413
  Thread(flags),
414
  // Initialize fields
415
  _on_thread_list(false),
416
  DEBUG_ONLY(_java_call_counter(0) COMMA)
417
  _entry_point(nullptr),
418
  _deopt_mark(nullptr),
419
  _deopt_nmethod(nullptr),
420
  _vframe_array_head(nullptr),
421
  _vframe_array_last(nullptr),
422
  _jvmti_deferred_updates(nullptr),
423
  _callee_target(nullptr),
424
  _vm_result(nullptr),
425
  _vm_result_2(nullptr),
426

427
  _current_pending_monitor(nullptr),
428
  _current_pending_monitor_is_from_java(true),
429
  _current_waiting_monitor(nullptr),
430
  _active_handles(nullptr),
431
  _free_handle_block(nullptr),
432

433
  _suspend_flags(0),
434

435
  _thread_state(_thread_new),
436
  _saved_exception_pc(nullptr),
437
#ifdef ASSERT
438
  _no_safepoint_count(0),
439
  _visited_for_critical_count(false),
440
#endif
441

442
  _terminated(_not_terminated),
443
  _in_deopt_handler(0),
444
  _doing_unsafe_access(false),
445
  _do_not_unlock_if_synchronized(false),
446
#if INCLUDE_JVMTI
447
  _carrier_thread_suspended(false),
448
  _is_in_VTMS_transition(false),
449
  _is_in_tmp_VTMS_transition(false),
450
  _is_disable_suspend(false),
451
  _VTMS_transition_mark(false),
452
#ifdef ASSERT
453
  _is_VTMS_transition_disabler(false),
454
#endif
455
#endif
456
  _jni_attach_state(_not_attaching_via_jni),
457
  _is_in_internal_oome_mark(false),
458
#if INCLUDE_JVMCI
459
  _pending_deoptimization(-1),
460
  _pending_monitorenter(false),
461
  _pending_transfer_to_interpreter(false),
462
  _pending_failed_speculation(0),
463
  _jvmci{nullptr},
464
  _libjvmci_runtime(nullptr),
465
  _jvmci_counters(nullptr),
466
  _jvmci_reserved0(0),
467
  _jvmci_reserved1(0),
468
  _jvmci_reserved_oop0(nullptr),
469
  _live_nmethod(nullptr),
470
#endif // INCLUDE_JVMCI
471

472
  _exception_oop(oop()),
473
  _exception_pc(nullptr),
474
  _exception_handler_pc(nullptr),
475
  _is_method_handle_return(0),
476

477
  _jni_active_critical(0),
478
  _pending_jni_exception_check_fn(nullptr),
479
  _depth_first_number(0),
480

481
  // JVMTI PopFrame support
482
  _popframe_condition(popframe_inactive),
483
  _frames_to_pop_failed_realloc(0),
484

485
  _cont_entry(nullptr),
486
  _cont_fastpath(nullptr),
487
  _cont_fastpath_thread_state(1),
488
  _held_monitor_count(0),
489
  _jni_monitor_count(0),
490

491
  _handshake(this),
492

493
  _popframe_preserved_args(nullptr),
494
  _popframe_preserved_args_size(0),
495

496
  _jvmti_thread_state(nullptr),
497
  _interp_only_mode(0),
498
  _should_post_on_exceptions_flag(JNI_FALSE),
499
  _thread_stat(new ThreadStatistics()),
500

501
  _parker(),
502

503
  _class_to_be_initialized(nullptr),
504

505
  _SleepEvent(ParkEvent::Allocate(this)),
506

507
  _lock_stack(this) {
508
  set_jni_functions(jni_functions());
509

510
#if INCLUDE_JVMCI
511
  assert(_jvmci._implicit_exception_pc == nullptr, "must be");
512
  if (JVMCICounterSize > 0) {
513
    resize_counters(0, (int) JVMCICounterSize);
514
  }
515
#endif // INCLUDE_JVMCI
516

517
  // Setup safepoint state info for this thread
518
  ThreadSafepointState::create(this);
519

520
  SafepointMechanism::initialize_header(this);
521

522
  set_requires_cross_modify_fence(false);
523

524
  pd_initialize();
525
  assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
526
}
527

528
JavaThread* JavaThread::create_attaching_thread() {
529
  JavaThread* jt = new JavaThread();
530
  jt->_jni_attach_state = _attaching_via_jni;
531
  return jt;
532
}
533

534
// interrupt support
535

536
void JavaThread::interrupt() {
537
  // All callers should have 'this' thread protected by a
538
  // ThreadsListHandle so that it cannot terminate and deallocate
539
  // itself.
540
  debug_only(check_for_dangling_thread_pointer(this);)
541

542
  // For Windows _interrupt_event
543
  WINDOWS_ONLY(osthread()->set_interrupted(true);)
544

545
  // For Thread.sleep
546
  _SleepEvent->unpark();
547

548
  // For JSR166 LockSupport.park
549
  parker()->unpark();
550

551
  // For ObjectMonitor and JvmtiRawMonitor
552
  _ParkEvent->unpark();
553
}
554

555
bool JavaThread::is_interrupted(bool clear_interrupted) {
556
  debug_only(check_for_dangling_thread_pointer(this);)
557

558
  if (_threadObj.peek() == nullptr) {
559
    // If there is no j.l.Thread then it is impossible to have
560
    // been interrupted. We can find null during VM initialization
561
    // or when a JNI thread is still in the process of attaching.
562
    // In such cases this must be the current thread.
563
    assert(this == Thread::current(), "invariant");
564
    return false;
565
  }
566

567
  bool interrupted = java_lang_Thread::interrupted(threadObj());
568

569
  // NOTE that since there is no "lock" around the interrupt and
570
  // is_interrupted operations, there is the possibility that the
571
  // interrupted flag will be "false" but that the
572
  // low-level events will be in the signaled state. This is
573
  // intentional. The effect of this is that Object.wait() and
574
  // LockSupport.park() will appear to have a spurious wakeup, which
575
  // is allowed and not harmful, and the possibility is so rare that
576
  // it is not worth the added complexity to add yet another lock.
577
  // For the sleep event an explicit reset is performed on entry
578
  // to JavaThread::sleep, so there is no early return. It has also been
579
  // recommended not to put the interrupted flag into the "event"
580
  // structure because it hides the issue.
581
  // Also, because there is no lock, we must only clear the interrupt
582
  // state if we are going to report that we were interrupted; otherwise
583
  // an interrupt that happens just after we read the field would be lost.
584
  if (interrupted && clear_interrupted) {
585
    assert(this == Thread::current(), "only the current thread can clear");
586
    java_lang_Thread::set_interrupted(threadObj(), false);
587
    WINDOWS_ONLY(osthread()->set_interrupted(false);)
588
  }
589
  return interrupted;
590
}
591

592
// This is only for use by JVMTI RawMonitorWait. It emulates the actions of
593
// the Java code in Object::wait which are not present in RawMonitorWait.
594
bool JavaThread::get_and_clear_interrupted() {
595
  if (!is_interrupted(false)) {
596
    return false;
597
  }
598
  oop thread_oop = vthread_or_thread();
599
  bool is_virtual = java_lang_VirtualThread::is_instance(thread_oop);
600

601
  if (!is_virtual) {
602
    return is_interrupted(true);
603
  }
604
  // Virtual thread: clear interrupt status for both virtual and
605
  // carrier threads under the interruptLock protection.
606
  JavaThread* current = JavaThread::current();
607
  HandleMark hm(current);
608
  Handle thread_h(current, thread_oop);
609
  ObjectLocker lock(Handle(current, java_lang_Thread::interrupt_lock(thread_h())), current);
610

611
  // re-check the interrupt status under the interruptLock protection
612
  bool interrupted = java_lang_Thread::interrupted(thread_h());
613

614
  if (interrupted) {
615
    assert(this == Thread::current(), "only the current thread can clear");
616
    java_lang_Thread::set_interrupted(thread_h(), false);  // clear for virtual
617
    java_lang_Thread::set_interrupted(threadObj(), false); // clear for carrier
618
    WINDOWS_ONLY(osthread()->set_interrupted(false);)
619
  }
620
  return interrupted;
621
}
622

623
void JavaThread::block_if_vm_exited() {
624
  if (_terminated == _vm_exited) {
625
    // _vm_exited is set at safepoint, and Threads_lock is never released
626
    // so we will block here forever.
627
    // Here we can be doing a jump from a safe state to an unsafe state without
628
    // proper transition, but it happens after the final safepoint has begun so
629
    // this jump won't cause any safepoint problems.
630
    set_thread_state(_thread_in_vm);
631
    Threads_lock->lock();
632
    ShouldNotReachHere();
633
  }
634
}
635

636
JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz, MEMFLAGS flags) : JavaThread(flags) {
637
  set_entry_point(entry_point);
638
  // Create the native thread itself.
639
  // %note runtime_23
640
  os::ThreadType thr_type = os::java_thread;
641
  thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
642
                                                            os::java_thread;
643
  os::create_thread(this, thr_type, stack_sz);
644
  // The _osthread may be null here because we ran out of memory (too many threads active).
645
  // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
646
  // may hold a lock and all locks must be unlocked before throwing the exception (throwing
647
  // the exception consists of creating the exception object & initializing it, initialization
648
  // will leave the VM via a JavaCall and then all locks must be unlocked).
649
  //
650
  // The thread is still suspended when we reach here. Thread must be explicit started
651
  // by creator! Furthermore, the thread must also explicitly be added to the Threads list
652
  // by calling Threads:add. The reason why this is not done here, is because the thread
653
  // object must be fully initialized (take a look at JVM_Start)
654
}
655

656
JavaThread::~JavaThread() {
657

658
  // Enqueue OopHandles for release by the service thread.
659
  add_oop_handles_for_release();
660

661
  // Return the sleep event to the free list
662
  ParkEvent::Release(_SleepEvent);
663
  _SleepEvent = nullptr;
664

665
  // Free any remaining  previous UnrollBlock
666
  vframeArray* old_array = vframe_array_last();
667

668
  if (old_array != nullptr) {
669
    Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
670
    old_array->set_unroll_block(nullptr);
671
    delete old_info;
672
    delete old_array;
673
  }
674

675
  JvmtiDeferredUpdates* updates = deferred_updates();
676
  if (updates != nullptr) {
677
    // This can only happen if thread is destroyed before deoptimization occurs.
678
    assert(updates->count() > 0, "Updates holder not deleted");
679
    // free deferred updates.
680
    delete updates;
681
    set_deferred_updates(nullptr);
682
  }
683

684
  // All Java related clean up happens in exit
685
  ThreadSafepointState::destroy(this);
686
  if (_thread_stat != nullptr) delete _thread_stat;
687

688
#if INCLUDE_JVMCI
689
  if (JVMCICounterSize > 0) {
690
    FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
691
  }
692
#endif // INCLUDE_JVMCI
693
}
694

695

696
// First JavaThread specific code executed by a new Java thread.
697
void JavaThread::pre_run() {
698
  // empty - see comments in run()
699
}
700

701
// The main routine called by a new Java thread. This isn't overridden
702
// by subclasses, instead different subclasses define a different "entry_point"
703
// which defines the actual logic for that kind of thread.
704
void JavaThread::run() {
705
  // initialize thread-local alloc buffer related fields
706
  initialize_tlab();
707

708
  _stack_overflow_state.create_stack_guard_pages();
709

710
  cache_global_variables();
711

712
  // Thread is now sufficiently initialized to be handled by the safepoint code as being
713
  // in the VM. Change thread state from _thread_new to _thread_in_vm
714
  assert(this->thread_state() == _thread_new, "wrong thread state");
715
  set_thread_state(_thread_in_vm);
716

717
  // Before a thread is on the threads list it is always safe, so after leaving the
718
  // _thread_new we should emit a instruction barrier. The distance to modified code
719
  // from here is probably far enough, but this is consistent and safe.
720
  OrderAccess::cross_modify_fence();
721

722
  assert(JavaThread::current() == this, "sanity check");
723
  assert(!Thread::current()->owns_locks(), "sanity check");
724

725
  DTRACE_THREAD_PROBE(start, this);
726

727
  // This operation might block. We call that after all safepoint checks for a new thread has
728
  // been completed.
729
  set_active_handles(JNIHandleBlock::allocate_block());
730

731
  if (JvmtiExport::should_post_thread_life()) {
732
    JvmtiExport::post_thread_start(this);
733

734
  }
735

736
  if (AlwaysPreTouchStacks) {
737
    pretouch_stack();
738
  }
739

740
  // We call another function to do the rest so we are sure that the stack addresses used
741
  // from there will be lower than the stack base just computed.
742
  thread_main_inner();
743
}
744

745
void JavaThread::thread_main_inner() {
746
  assert(JavaThread::current() == this, "sanity check");
747
  assert(_threadObj.peek() != nullptr, "just checking");
748

749
  // Execute thread entry point unless this thread has a pending exception.
750
  // Note: Due to JVMTI StopThread we can have pending exceptions already!
751
  if (!this->has_pending_exception()) {
752
    {
753
      ResourceMark rm(this);
754
      this->set_native_thread_name(this->name());
755
    }
756
    HandleMark hm(this);
757
    this->entry_point()(this, this);
758
  }
759

760
  DTRACE_THREAD_PROBE(stop, this);
761

762
  // Cleanup is handled in post_run()
763
}
764

765
// Shared teardown for all JavaThreads
766
void JavaThread::post_run() {
767
  this->exit(false);
768
  this->unregister_thread_stack_with_NMT();
769
  // Defer deletion to here to ensure 'this' is still referenceable in call_run
770
  // for any shared tear-down.
771
  this->smr_delete();
772
}
773

774
static void ensure_join(JavaThread* thread) {
775
  // We do not need to grab the Threads_lock, since we are operating on ourself.
776
  Handle threadObj(thread, thread->threadObj());
777
  assert(threadObj.not_null(), "java thread object must exist");
778
  ObjectLocker lock(threadObj, thread);
779
  // Thread is exiting. So set thread_status field in  java.lang.Thread class to TERMINATED.
780
  java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
781
  // Clear the native thread instance - this makes isAlive return false and allows the join()
782
  // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model
783
  // requirements.
784
  assert(java_lang_Thread::thread(threadObj()) == thread, "must be alive");
785
  java_lang_Thread::release_set_thread(threadObj(), nullptr);
786
  lock.notify_all(thread);
787
  // Ignore pending exception, since we are exiting anyway
788
  thread->clear_pending_exception();
789
}
790

791
static bool is_daemon(oop threadObj) {
792
  return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj));
793
}
794

795
// For any new cleanup additions, please check to see if they need to be applied to
796
// cleanup_failed_attach_current_thread as well.
797
void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
798
  assert(this == JavaThread::current(), "thread consistency check");
799
  assert(!is_exiting(), "should not be exiting or terminated already");
800

801
  elapsedTimer _timer_exit_phase1;
802
  elapsedTimer _timer_exit_phase2;
803
  elapsedTimer _timer_exit_phase3;
804
  elapsedTimer _timer_exit_phase4;
805

806
  if (log_is_enabled(Debug, os, thread, timer)) {
807
    _timer_exit_phase1.start();
808
  }
809

810
  HandleMark hm(this);
811
  Handle uncaught_exception(this, this->pending_exception());
812
  this->clear_pending_exception();
813
  Handle threadObj(this, this->threadObj());
814
  assert(threadObj.not_null(), "Java thread object should be created");
815

816
  if (!destroy_vm) {
817
    if (uncaught_exception.not_null()) {
818
      EXCEPTION_MARK;
819
      // Call method Thread.dispatchUncaughtException().
820
      Klass* thread_klass = vmClasses::Thread_klass();
821
      JavaValue result(T_VOID);
822
      JavaCalls::call_virtual(&result,
823
                              threadObj, thread_klass,
824
                              vmSymbols::dispatchUncaughtException_name(),
825
                              vmSymbols::throwable_void_signature(),
826
                              uncaught_exception,
827
                              THREAD);
828
      if (HAS_PENDING_EXCEPTION) {
829
        ResourceMark rm(this);
830
        jio_fprintf(defaultStream::error_stream(),
831
                    "\nException: %s thrown from the UncaughtExceptionHandler"
832
                    " in thread \"%s\"\n",
833
                    pending_exception()->klass()->external_name(),
834
                    name());
835
        CLEAR_PENDING_EXCEPTION;
836
      }
837
    }
838

839
    if (!is_Compiler_thread()) {
840
      // We have finished executing user-defined Java code and now have to do the
841
      // implementation specific clean-up by calling Thread.exit(). We prevent any
842
      // asynchronous exceptions from being delivered while in Thread.exit()
843
      // to ensure the clean-up is not corrupted.
844
      NoAsyncExceptionDeliveryMark _no_async(this);
845

846
      EXCEPTION_MARK;
847
      JavaValue result(T_VOID);
848
      Klass* thread_klass = vmClasses::Thread_klass();
849
      JavaCalls::call_virtual(&result,
850
                              threadObj, thread_klass,
851
                              vmSymbols::exit_method_name(),
852
                              vmSymbols::void_method_signature(),
853
                              THREAD);
854
      CLEAR_PENDING_EXCEPTION;
855
    }
856

857
    // notify JVMTI
858
    if (JvmtiExport::should_post_thread_life()) {
859
      JvmtiExport::post_thread_end(this);
860
    }
861
  } else {
862
    // before_exit() has already posted JVMTI THREAD_END events
863
  }
864

865
  // Cleanup any pending async exception now since we cannot access oops after
866
  // BarrierSet::barrier_set()->on_thread_detach() has been executed.
867
  if (has_async_exception_condition()) {
868
    handshake_state()->clean_async_exception_operation();
869
  }
870

871
  // The careful dance between thread suspension and exit is handled here.
872
  // Since we are in thread_in_vm state and suspension is done with handshakes,
873
  // we can just put in the exiting state and it will be correctly handled.
874
  // Also, no more async exceptions will be added to the queue after this point.
875
  set_terminated(_thread_exiting);
876
  ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
877

878
  if (log_is_enabled(Debug, os, thread, timer)) {
879
    _timer_exit_phase1.stop();
880
    _timer_exit_phase2.start();
881
  }
882

883
  // Capture daemon status before the thread is marked as terminated.
884
  bool daemon = is_daemon(threadObj());
885

886
  // Notify waiters on thread object. This has to be done after exit() is called
887
  // on the thread (if the thread is the last thread in a daemon ThreadGroup the
888
  // group should have the destroyed bit set before waiters are notified).
889
  ensure_join(this);
890
  assert(!this->has_pending_exception(), "ensure_join should have cleared");
891

892
  if (log_is_enabled(Debug, os, thread, timer)) {
893
    _timer_exit_phase2.stop();
894
    _timer_exit_phase3.start();
895
  }
896
  // 6282335 JNI DetachCurrentThread spec states that all Java monitors
897
  // held by this thread must be released. The spec does not distinguish
898
  // between JNI-acquired and regular Java monitors. We can only see
899
  // regular Java monitors here if monitor enter-exit matching is broken.
900
  //
901
  // ensure_join() ignores IllegalThreadStateExceptions, and so does
902
  // ObjectSynchronizer::release_monitors_owned_by_thread().
903
  if (exit_type == jni_detach) {
904
    // Sanity check even though JNI DetachCurrentThread() would have
905
    // returned JNI_ERR if there was a Java frame. JavaThread exit
906
    // should be done executing Java code by the time we get here.
907
    assert(!this->has_last_Java_frame(),
908
           "should not have a Java frame when detaching or exiting");
909
    ObjectSynchronizer::release_monitors_owned_by_thread(this);
910
    assert(!this->has_pending_exception(), "release_monitors should have cleared");
911
    // Check for monitor counts being out of sync.
912
    assert(held_monitor_count() == jni_monitor_count(),
913
           "held monitor count should be equal to jni: " INTX_FORMAT " != " INTX_FORMAT,
914
           held_monitor_count(), jni_monitor_count());
915
    // All in-use monitors, including JNI-locked ones, should have been released above.
916
    assert(held_monitor_count() == 0, "Failed to unlock " INTX_FORMAT " object monitors",
917
           held_monitor_count());
918
  } else {
919
    // Check for monitor counts being out of sync.
920
    assert(held_monitor_count() == jni_monitor_count(),
921
           "held monitor count should be equal to jni: " INTX_FORMAT " != " INTX_FORMAT,
922
           held_monitor_count(), jni_monitor_count());
923
    // It is possible that a terminating thread failed to unlock monitors it locked
924
    // via JNI so we don't assert the count is zero.
925
  }
926

927
  if (CheckJNICalls && jni_monitor_count() > 0) {
928
    // We would like a fatal here, but due to we never checked this before there
929
    // is a lot of tests which breaks, even with an error log.
930
    log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.",
931
                   exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id());
932
  }
933

934
  // These things needs to be done while we are still a Java Thread. Make sure that thread
935
  // is in a consistent state, in case GC happens
936
  JFR_ONLY(Jfr::on_thread_exit(this);)
937

938
  if (active_handles() != nullptr) {
939
    JNIHandleBlock* block = active_handles();
940
    set_active_handles(nullptr);
941
    JNIHandleBlock::release_block(block);
942
  }
943

944
  if (free_handle_block() != nullptr) {
945
    JNIHandleBlock* block = free_handle_block();
946
    set_free_handle_block(nullptr);
947
    JNIHandleBlock::release_block(block);
948
  }
949

950
  // These have to be removed while this is still a valid thread.
951
  _stack_overflow_state.remove_stack_guard_pages();
952

953
  if (UseTLAB) {
954
    tlab().retire();
955
  }
956

957
  if (JvmtiEnv::environments_might_exist()) {
958
    JvmtiExport::cleanup_thread(this);
959
  }
960

961
  // We need to cache the thread name for logging purposes below as once
962
  // we have called on_thread_detach this thread must not access any oops.
963
  char* thread_name = nullptr;
964
  if (log_is_enabled(Debug, os, thread, timer)) {
965
    ResourceMark rm(this);
966
    thread_name = os::strdup(name());
967
  }
968

969
  if (log_is_enabled(Info, os, thread)) {
970
    ResourceMark rm(this);
971
    log_info(os, thread)("JavaThread %s (name: \"%s\", tid: " UINTX_FORMAT ").",
972
                         exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
973
                         name(), os::current_thread_id());
974
  }
975

976
  if (log_is_enabled(Debug, os, thread, timer)) {
977
    _timer_exit_phase3.stop();
978
    _timer_exit_phase4.start();
979
  }
980

981
#if INCLUDE_JVMCI
982
  if (JVMCICounterSize > 0) {
983
    if (jvmci_counters_include(this)) {
984
      for (int i = 0; i < JVMCICounterSize; i++) {
985
        _jvmci_old_thread_counters[i] += _jvmci_counters[i];
986
      }
987
    }
988
  }
989
#endif // INCLUDE_JVMCI
990

991
  // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
992
  // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
993
  Threads::remove(this, daemon);
994

995
  if (log_is_enabled(Debug, os, thread, timer)) {
996
    _timer_exit_phase4.stop();
997
    log_debug(os, thread, timer)("name='%s'"
998
                                 ", exit-phase1=" JLONG_FORMAT
999
                                 ", exit-phase2=" JLONG_FORMAT
1000
                                 ", exit-phase3=" JLONG_FORMAT
1001
                                 ", exit-phase4=" JLONG_FORMAT,
1002
                                 thread_name,
1003
                                 _timer_exit_phase1.milliseconds(),
1004
                                 _timer_exit_phase2.milliseconds(),
1005
                                 _timer_exit_phase3.milliseconds(),
1006
                                 _timer_exit_phase4.milliseconds());
1007
    os::free(thread_name);
1008
  }
1009
}
1010

1011
void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
1012
  if (active_handles() != nullptr) {
1013
    JNIHandleBlock* block = active_handles();
1014
    set_active_handles(nullptr);
1015
    JNIHandleBlock::release_block(block);
1016
  }
1017

1018
  if (free_handle_block() != nullptr) {
1019
    JNIHandleBlock* block = free_handle_block();
1020
    set_free_handle_block(nullptr);
1021
    JNIHandleBlock::release_block(block);
1022
  }
1023

1024
  // These have to be removed while this is still a valid thread.
1025
  _stack_overflow_state.remove_stack_guard_pages();
1026

1027
  if (UseTLAB) {
1028
    tlab().retire();
1029
  }
1030

1031
  Threads::remove(this, is_daemon);
1032
  this->smr_delete();
1033
}
1034

1035
JavaThread* JavaThread::active() {
1036
  Thread* thread = Thread::current();
1037
  if (thread->is_Java_thread()) {
1038
    return JavaThread::cast(thread);
1039
  } else {
1040
    assert(thread->is_VM_thread(), "this must be a vm thread");
1041
    VM_Operation* op = ((VMThread*) thread)->vm_operation();
1042
    JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread());
1043
    return ret;
1044
  }
1045
}
1046

1047
bool JavaThread::is_lock_owned(address adr) const {
1048
  assert(LockingMode != LM_LIGHTWEIGHT, "should not be called with new lightweight locking");
1049
  return is_in_full_stack(adr);
1050
}
1051

1052
oop JavaThread::exception_oop() const {
1053
  return Atomic::load(&_exception_oop);
1054
}
1055

1056
void JavaThread::set_exception_oop(oop o) {
1057
  Atomic::store(&_exception_oop, o);
1058
}
1059

1060
void JavaThread::handle_special_runtime_exit_condition() {
1061
  if (is_obj_deopt_suspend()) {
1062
    frame_anchor()->make_walkable();
1063
    wait_for_object_deoptimization();
1064
  }
1065
  JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1066
}
1067

1068

1069
// Asynchronous exceptions support
1070
//
1071
void JavaThread::handle_async_exception(oop java_throwable) {
1072
  assert(java_throwable != nullptr, "should have an _async_exception to throw");
1073
  assert(!is_at_poll_safepoint(), "should have never called this method");
1074

1075
  if (has_last_Java_frame()) {
1076
    frame f = last_frame();
1077
    if (f.is_runtime_frame()) {
1078
      // If the topmost frame is a runtime stub, then we are calling into
1079
      // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1080
      // must deoptimize the caller before continuing, as the compiled exception
1081
      // handler table may not be valid.
1082
      RegisterMap reg_map(this,
1083
                          RegisterMap::UpdateMap::skip,
1084
                          RegisterMap::ProcessFrames::include,
1085
                          RegisterMap::WalkContinuation::skip);
1086
      frame compiled_frame = f.sender(&reg_map);
1087
      if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1088
        Deoptimization::deoptimize(this, compiled_frame);
1089
      }
1090
    }
1091
  }
1092

1093
  // We cannot call Exceptions::_throw(...) here because we cannot block
1094
  set_pending_exception(java_throwable, __FILE__, __LINE__);
1095

1096
  clear_scopedValueBindings();
1097

1098
  LogTarget(Info, exceptions) lt;
1099
  if (lt.is_enabled()) {
1100
    ResourceMark rm;
1101
    LogStream ls(lt);
1102
    ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1103
    if (has_last_Java_frame()) {
1104
      frame f = last_frame();
1105
      ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1106
    }
1107
    ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1108
  }
1109
}
1110

1111
void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1112
  // Do not throw asynchronous exceptions against the compiler thread
1113
  // or if the thread is already exiting.
1114
  if (!can_call_java() || is_exiting()) {
1115
    delete aeh;
1116
    return;
1117
  }
1118

1119
  oop exception = aeh->exception();
1120
  Handshake::execute(aeh, this);  // Install asynchronous handshake
1121

1122
  ResourceMark rm;
1123
  if (log_is_enabled(Info, exceptions)) {
1124
    log_info(exceptions)("Pending Async. exception installed of type: %s",
1125
                         InstanceKlass::cast(exception->klass())->external_name());
1126
  }
1127
  // for AbortVMOnException flag
1128
  Exceptions::debug_check_abort(exception->klass()->external_name());
1129

1130
  oop vt_oop = vthread();
1131
  if (vt_oop == nullptr || !vt_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1132
    // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1133
    java_lang_Thread::set_interrupted(threadObj(), true);
1134
    this->interrupt();
1135
  }
1136
}
1137

1138
class InstallAsyncExceptionHandshake : public HandshakeClosure {
1139
  AsyncExceptionHandshake* _aeh;
1140
public:
1141
  InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1142
    HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1143
  ~InstallAsyncExceptionHandshake() {
1144
    // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh.
1145
    delete _aeh;
1146
  }
1147
  void do_thread(Thread* thr) {
1148
    JavaThread* target = JavaThread::cast(thr);
1149
    target->install_async_exception(_aeh);
1150
    _aeh = nullptr;
1151
  }
1152
};
1153

1154
void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1155
  OopHandle e(Universe::vm_global(), java_throwable);
1156
  InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1157
  Handshake::execute(&iaeh, target);
1158
}
1159

1160
#if INCLUDE_JVMTI
1161
void JavaThread::set_is_in_VTMS_transition(bool val) {
1162
  _is_in_VTMS_transition = val;
1163
}
1164

1165
#ifdef ASSERT
1166
void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1167
  _is_VTMS_transition_disabler = val;
1168
}
1169
#endif
1170
#endif
1171

1172
// External suspension mechanism.
1173
//
1174
// Guarantees on return (for a valid target thread):
1175
//   - Target thread will not execute any new bytecode.
1176
//   - Target thread will not enter any new monitors.
1177
//
1178
bool JavaThread::java_suspend() {
1179
#if INCLUDE_JVMTI
1180
  // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1181
  assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1182
  assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1183
#endif
1184

1185
  guarantee(Thread::is_JavaThread_protected(/* target */ this),
1186
            "target JavaThread is not protected in calling context.");
1187
  return this->handshake_state()->suspend();
1188
}
1189

1190
bool JavaThread::java_resume() {
1191
  guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1192
            "missing ThreadsListHandle in calling context.");
1193
  return this->handshake_state()->resume();
1194
}
1195

1196
// Wait for another thread to perform object reallocation and relocking on behalf of
1197
// this thread. The current thread is required to change to _thread_blocked in order
1198
// to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1199
// handshake safe, the other thread can complete the handshake used to synchronize
1200
// with this thread and then perform the reallocation and relocking.
1201
// See EscapeBarrier::sync_and_suspend_*()
1202

1203
void JavaThread::wait_for_object_deoptimization() {
1204
  assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1205
  assert(this == Thread::current(), "invariant");
1206

1207
  bool spin_wait = os::is_MP();
1208
  do {
1209
    ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1210
    // Wait for object deoptimization if requested.
1211
    if (spin_wait) {
1212
      // A single deoptimization is typically very short. Microbenchmarks
1213
      // showed 5% better performance when spinning.
1214
      const uint spin_limit = 10 * SpinYield::default_spin_limit;
1215
      SpinYield spin(spin_limit);
1216
      for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1217
        spin.wait();
1218
      }
1219
      // Spin just once
1220
      spin_wait = false;
1221
    } else {
1222
      MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1223
      if (is_obj_deopt_suspend()) {
1224
        ml.wait();
1225
      }
1226
    }
1227
    // A handshake for obj. deoptimization suspend could have been processed so
1228
    // we must check after processing.
1229
  } while (is_obj_deopt_suspend());
1230
}
1231

1232
#ifdef ASSERT
1233
// Verify the JavaThread has not yet been published in the Threads::list, and
1234
// hence doesn't need protection from concurrent access at this stage.
1235
void JavaThread::verify_not_published() {
1236
  // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1237
  // since an unpublished JavaThread doesn't participate in the
1238
  // Thread-SMR protocol for keeping a ThreadsList alive.
1239
  assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1240
}
1241
#endif
1242

1243
// Slow path when the native==>Java barriers detect a safepoint/handshake is
1244
// pending, when _suspend_flags is non-zero or when we need to process a stack
1245
// watermark. Also check for pending async exceptions (except unsafe access error).
1246
// Note only the native==>Java barriers can call this function when thread state
1247
// is _thread_in_native_trans.
1248
void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1249
  assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1250
  assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1251

1252
  thread->set_thread_state(_thread_in_vm);
1253

1254
  // Enable WXWrite: called directly from interpreter native wrapper.
1255
  MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1256

1257
  SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1258

1259
  // After returning from native, it could be that the stack frames are not
1260
  // yet safe to use. We catch such situations in the subsequent stack watermark
1261
  // barrier, which will trap unsafe stack frames.
1262
  StackWatermarkSet::before_unwind(thread);
1263
}
1264

1265
#ifndef PRODUCT
1266
// Deoptimization
1267
// Function for testing deoptimization
1268
void JavaThread::deoptimize() {
1269
  StackFrameStream fst(this, false /* update */, true /* process_frames */);
1270
  bool deopt = false;           // Dump stack only if a deopt actually happens.
1271
  bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1272
  // Iterate over all frames in the thread and deoptimize
1273
  for (; !fst.is_done(); fst.next()) {
1274
    if (fst.current()->can_be_deoptimized()) {
1275

1276
      if (only_at) {
1277
        // Deoptimize only at particular bcis.  DeoptimizeOnlyAt
1278
        // consists of comma or carriage return separated numbers so
1279
        // search for the current bci in that string.
1280
        address    pc = fst.current()->pc();
1281
        nmethod*   nm = fst.current()->cb()->as_nmethod();
1282
        ScopeDesc* sd = nm->scope_desc_at(pc);
1283
        char buffer[8];
1284
        jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1285
        size_t len = strlen(buffer);
1286
        const char * found = strstr(DeoptimizeOnlyAt, buffer);
1287
        while (found != nullptr) {
1288
          if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1289
              (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1290
            // Check that the bci found is bracketed by terminators.
1291
            break;
1292
          }
1293
          found = strstr(found + 1, buffer);
1294
        }
1295
        if (!found) {
1296
          continue;
1297
        }
1298
      }
1299

1300
      if (DebugDeoptimization && !deopt) {
1301
        deopt = true; // One-time only print before deopt
1302
        tty->print_cr("[BEFORE Deoptimization]");
1303
        trace_frames();
1304
        trace_stack();
1305
      }
1306
      Deoptimization::deoptimize(this, *fst.current());
1307
    }
1308
  }
1309

1310
  if (DebugDeoptimization && deopt) {
1311
    tty->print_cr("[AFTER Deoptimization]");
1312
    trace_frames();
1313
  }
1314
}
1315

1316

1317
// Make zombies
1318
void JavaThread::make_zombies() {
1319
  for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1320
    if (fst.current()->can_be_deoptimized()) {
1321
      // it is a Java nmethod
1322
      nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1323
      assert(nm != nullptr, "did not find nmethod");
1324
      nm->make_not_entrant();
1325
    }
1326
  }
1327
}
1328
#endif // PRODUCT
1329

1330

1331
void JavaThread::deoptimize_marked_methods() {
1332
  if (!has_last_Java_frame()) return;
1333
  StackFrameStream fst(this, false /* update */, true /* process_frames */);
1334
  for (; !fst.is_done(); fst.next()) {
1335
    if (fst.current()->should_be_deoptimized()) {
1336
      Deoptimization::deoptimize(this, *fst.current());
1337
    }
1338
  }
1339
}
1340

1341
#ifdef ASSERT
1342
void JavaThread::verify_frame_info() {
1343
  assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1344
         (has_last_Java_frame() && java_call_counter() > 0),
1345
         "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1346
         has_last_Java_frame() ? "true" : "false", java_call_counter());
1347
}
1348
#endif
1349

1350
// Push on a new block of JNI handles.
1351
void JavaThread::push_jni_handle_block() {
1352
  // Allocate a new block for JNI handles.
1353
  // Inlined code from jni_PushLocalFrame()
1354
  JNIHandleBlock* old_handles = active_handles();
1355
  JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1356
  assert(old_handles != nullptr && new_handles != nullptr, "should not be null");
1357
  new_handles->set_pop_frame_link(old_handles);  // make sure java handles get gc'd.
1358
  set_active_handles(new_handles);
1359
}
1360

1361
// Pop off the current block of JNI handles.
1362
void JavaThread::pop_jni_handle_block() {
1363
  // Release our JNI handle block
1364
  JNIHandleBlock* old_handles = active_handles();
1365
  JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1366
  assert(new_handles != nullptr, "should never set active handles to null");
1367
  set_active_handles(new_handles);
1368
  old_handles->set_pop_frame_link(nullptr);
1369
  JNIHandleBlock::release_block(old_handles, this);
1370
}
1371

1372
void JavaThread::oops_do_no_frames(OopClosure* f, NMethodClosure* cf) {
1373
  // Verify that the deferred card marks have been flushed.
1374
  assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1375

1376
  // Traverse the GCHandles
1377
  Thread::oops_do_no_frames(f, cf);
1378

1379
  if (active_handles() != nullptr) {
1380
    active_handles()->oops_do(f);
1381
  }
1382

1383
  DEBUG_ONLY(verify_frame_info();)
1384

1385
  assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!");
1386
  // If we have deferred set_locals there might be oops waiting to be
1387
  // written
1388
  GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1389
  if (list != nullptr) {
1390
    for (int i = 0; i < list->length(); i++) {
1391
      list->at(i)->oops_do(f);
1392
    }
1393
  }
1394

1395
  // Traverse instance variables at the end since the GC may be moving things
1396
  // around using this function
1397
  f->do_oop((oop*) &_vm_result);
1398
  f->do_oop((oop*) &_exception_oop);
1399
#if INCLUDE_JVMCI
1400
  f->do_oop((oop*) &_jvmci_reserved_oop0);
1401

1402
  if (_live_nmethod != nullptr && cf != nullptr) {
1403
    cf->do_nmethod(_live_nmethod);
1404
  }
1405
#endif
1406

1407
  if (jvmti_thread_state() != nullptr) {
1408
    jvmti_thread_state()->oops_do(f, cf);
1409
  }
1410

1411
  // The continuation oops are really on the stack. But there is typically at most
1412
  // one of those per thread, so we handle them here in the oops_do_no_frames part
1413
  // so that we don't have to sprinkle as many stack watermark checks where these
1414
  // oops are used. We just need to make sure the thread has started processing.
1415
  ContinuationEntry* entry = _cont_entry;
1416
  while (entry != nullptr) {
1417
    f->do_oop((oop*)entry->cont_addr());
1418
    f->do_oop((oop*)entry->chunk_addr());
1419
    entry = entry->parent();
1420
  }
1421

1422
  if (LockingMode == LM_LIGHTWEIGHT) {
1423
    lock_stack().oops_do(f);
1424
  }
1425
}
1426

1427
void JavaThread::oops_do_frames(OopClosure* f, NMethodClosure* cf) {
1428
  if (!has_last_Java_frame()) {
1429
    return;
1430
  }
1431
  // Finish any pending lazy GC activity for the frames
1432
  StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc);
1433
  // Traverse the execution stack
1434
  for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1435
    fst.current()->oops_do(f, cf, fst.register_map());
1436
  }
1437
}
1438

1439
#ifdef ASSERT
1440
void JavaThread::verify_states_for_handshake() {
1441
  // This checks that the thread has a correct frame state during a handshake.
1442
  verify_frame_info();
1443
}
1444
#endif
1445

1446
void JavaThread::nmethods_do(NMethodClosure* cf) {
1447
  DEBUG_ONLY(verify_frame_info();)
1448
  MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1449

1450
  if (has_last_Java_frame()) {
1451
    // Traverse the execution stack
1452
    for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1453
      fst.current()->nmethod_do(cf);
1454
    }
1455
  }
1456

1457
  if (jvmti_thread_state() != nullptr) {
1458
    jvmti_thread_state()->nmethods_do(cf);
1459
  }
1460

1461
#if INCLUDE_JVMCI
1462
  if (_live_nmethod != nullptr) {
1463
    cf->do_nmethod(_live_nmethod);
1464
  }
1465
#endif
1466
}
1467

1468
void JavaThread::metadata_do(MetadataClosure* f) {
1469
  if (has_last_Java_frame()) {
1470
    // Traverse the execution stack to call f() on the methods in the stack
1471
    for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1472
      fst.current()->metadata_do(f);
1473
    }
1474
  } else if (is_Compiler_thread()) {
1475
    // need to walk ciMetadata in current compile tasks to keep alive.
1476
    CompilerThread* ct = (CompilerThread*)this;
1477
    if (ct->env() != nullptr) {
1478
      ct->env()->metadata_do(f);
1479
    }
1480
    CompileTask* task = ct->task();
1481
    if (task != nullptr) {
1482
      task->metadata_do(f);
1483
    }
1484
  }
1485
}
1486

1487
// Printing
1488
static const char* _get_thread_state_name(JavaThreadState _thread_state) {
1489
  switch (_thread_state) {
1490
  case _thread_uninitialized:     return "_thread_uninitialized";
1491
  case _thread_new:               return "_thread_new";
1492
  case _thread_new_trans:         return "_thread_new_trans";
1493
  case _thread_in_native:         return "_thread_in_native";
1494
  case _thread_in_native_trans:   return "_thread_in_native_trans";
1495
  case _thread_in_vm:             return "_thread_in_vm";
1496
  case _thread_in_vm_trans:       return "_thread_in_vm_trans";
1497
  case _thread_in_Java:           return "_thread_in_Java";
1498
  case _thread_in_Java_trans:     return "_thread_in_Java_trans";
1499
  case _thread_blocked:           return "_thread_blocked";
1500
  case _thread_blocked_trans:     return "_thread_blocked_trans";
1501
  default:                        return "unknown thread state";
1502
  }
1503
}
1504

1505
void JavaThread::print_thread_state_on(outputStream *st) const {
1506
  st->print_cr("   JavaThread state: %s", _get_thread_state_name(_thread_state));
1507
}
1508

1509
// Called by Threads::print() for VM_PrintThreads operation
1510
void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1511
  st->print_raw("\"");
1512
  st->print_raw(name());
1513
  st->print_raw("\" ");
1514
  oop thread_oop = threadObj();
1515
  if (thread_oop != nullptr) {
1516
    st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1517
    if (java_lang_Thread::is_daemon(thread_oop))  st->print("daemon ");
1518
    st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1519
  }
1520
  Thread::print_on(st, print_extended_info);
1521
  // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1522
  st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1523
  if (thread_oop != nullptr) {
1524
    if (is_vthread_mounted()) {
1525
      oop vt = vthread();
1526
      assert(vt != nullptr, "");
1527
      st->print_cr("   Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1528
    } else {
1529
      st->print_cr("   java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1530
    }
1531
  }
1532
#ifndef PRODUCT
1533
  _safepoint_state->print_on(st);
1534
#endif // PRODUCT
1535
  if (is_Compiler_thread()) {
1536
    CompileTask *task = ((CompilerThread*)this)->task();
1537
    if (task != nullptr) {
1538
      st->print("   Compiling: ");
1539
      task->print(st, nullptr, true, false);
1540
    } else {
1541
      st->print("   No compile task");
1542
    }
1543
    st->cr();
1544
  }
1545
}
1546

1547
void JavaThread::print() const { print_on(tty); }
1548

1549
void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1550
  st->print("%s", get_thread_name_string(buf, buflen));
1551
}
1552

1553
// Called by fatal error handler. The difference between this and
1554
// JavaThread::print() is that we can't grab lock or allocate memory.
1555
void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1556
  st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1557
  Thread* current = Thread::current_or_null_safe();
1558
  assert(current != nullptr, "cannot be called by a detached thread");
1559
  st->fill_to(60);
1560
  if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1561
    // Only access threadObj() if current thread is not a JavaThread
1562
    // or if it is a JavaThread that can safely access oops.
1563
    oop thread_obj = threadObj();
1564
    if (thread_obj != nullptr) {
1565
      st->print(java_lang_Thread::is_daemon(thread_obj) ? " daemon" : "       ");
1566
    }
1567
  }
1568
  st->print(" [");
1569
  st->print("%s", _get_thread_state_name(_thread_state));
1570
  if (osthread()) {
1571
    st->print(", id=%d", osthread()->thread_id());
1572
  }
1573
  // Use raw field members for stack base/size as this could be
1574
  // called before a thread has run enough to initialize them.
1575
  st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ") (" PROPERFMT ")",
1576
            p2i(_stack_base - _stack_size), p2i(_stack_base),
1577
            PROPERFMTARGS(_stack_size));
1578
  st->print("]");
1579

1580
  ThreadsSMRSupport::print_info_on(this, st);
1581
  return;
1582
}
1583

1584

1585
// Verification
1586

1587
void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1588
  // ignore if there is no stack
1589
  if (!has_last_Java_frame()) return;
1590
  // traverse the stack frames. Starts from top frame.
1591
  for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1592
    frame* fr = fst.current();
1593
    f(fr, fst.register_map());
1594
  }
1595
}
1596

1597
static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1598

1599
void JavaThread::verify() {
1600
  // Verify oops in the thread.
1601
  oops_do(&VerifyOopClosure::verify_oop, nullptr);
1602

1603
  // Verify the stack frames.
1604
  frames_do(frame_verify);
1605
}
1606

1607
// CR 6300358 (sub-CR 2137150)
1608
// Most callers of this method assume that it can't return null but a
1609
// thread may not have a name whilst it is in the process of attaching to
1610
// the VM - see CR 6412693, and there are places where a JavaThread can be
1611
// seen prior to having its threadObj set (e.g., JNI attaching threads and
1612
// if vm exit occurs during initialization). These cases can all be accounted
1613
// for such that this method never returns null.
1614
const char* JavaThread::name() const  {
1615
  if (Thread::is_JavaThread_protected(/* target */ this)) {
1616
    // The target JavaThread is protected so get_thread_name_string() is safe:
1617
    return get_thread_name_string();
1618
  }
1619

1620
  // The target JavaThread is not protected so we return the default:
1621
  return Thread::name();
1622
}
1623

1624
// Like name() but doesn't include the protection check. This must only be
1625
// called when it is known to be safe, even though the protection check can't tell
1626
// that e.g. when this thread is the init_thread() - see instanceKlass.cpp.
1627
const char* JavaThread::name_raw() const  {
1628
  return get_thread_name_string();
1629
}
1630

1631
// Returns a non-null representation of this thread's name, or a suitable
1632
// descriptive string if there is no set name.
1633
const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1634
  const char* name_str;
1635
#ifdef ASSERT
1636
  Thread* current = Thread::current_or_null_safe();
1637
  assert(current != nullptr, "cannot be called by a detached thread");
1638
  if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1639
    // Only access threadObj() if current thread is not a JavaThread
1640
    // or if it is a JavaThread that can safely access oops.
1641
#endif
1642
    oop thread_obj = threadObj();
1643
    if (thread_obj != nullptr) {
1644
      oop name = java_lang_Thread::name(thread_obj);
1645
      if (name != nullptr) {
1646
        if (buf == nullptr) {
1647
          name_str = java_lang_String::as_utf8_string(name);
1648
        } else {
1649
          name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1650
        }
1651
      } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1652
        name_str = "<no-name - thread is attaching>";
1653
      } else {
1654
        name_str = "<un-named>";
1655
      }
1656
    } else {
1657
      name_str = Thread::name();
1658
    }
1659
#ifdef ASSERT
1660
  } else {
1661
    // Current JavaThread has exited...
1662
    if (current == this) {
1663
      // ... and is asking about itself:
1664
      name_str = "<no-name - current JavaThread has exited>";
1665
    } else {
1666
      // ... and it can't safely determine this JavaThread's name so
1667
      // use the default thread name.
1668
      name_str = Thread::name();
1669
    }
1670
  }
1671
#endif
1672
  assert(name_str != nullptr, "unexpected null thread name");
1673
  return name_str;
1674
}
1675

1676
// Helper to extract the name from the thread oop for logging.
1677
const char* JavaThread::name_for(oop thread_obj) {
1678
  assert(thread_obj != nullptr, "precondition");
1679
  oop name = java_lang_Thread::name(thread_obj);
1680
  const char* name_str;
1681
  if (name != nullptr) {
1682
    name_str = java_lang_String::as_utf8_string(name);
1683
  } else {
1684
    name_str = "<un-named>";
1685
  }
1686
  return name_str;
1687
}
1688

1689
void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1690

1691
  assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1692
  assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1693
  // Link Java Thread object <-> C++ Thread
1694

1695
  // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1696
  // and put it into a new Handle.  The Handle "thread_oop" can then
1697
  // be used to pass the C++ thread object to other methods.
1698

1699
  // Set the Java level thread object (jthread) field of the
1700
  // new thread (a JavaThread *) to C++ thread object using the
1701
  // "thread_oop" handle.
1702

1703
  // Set the thread field (a JavaThread *) of the
1704
  // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1705

1706
  Handle thread_oop(Thread::current(),
1707
                    JNIHandles::resolve_non_null(jni_thread));
1708
  assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1709
         "must be initialized");
1710
  set_threadOopHandles(thread_oop());
1711

1712
  if (prio == NoPriority) {
1713
    prio = java_lang_Thread::priority(thread_oop());
1714
    assert(prio != NoPriority, "A valid priority should be present");
1715
  }
1716

1717
  // Push the Java priority down to the native thread; needs Threads_lock
1718
  Thread::set_priority(this, prio);
1719

1720
  // Add the new thread to the Threads list and set it in motion.
1721
  // We must have threads lock in order to call Threads::add.
1722
  // It is crucial that we do not block before the thread is
1723
  // added to the Threads list for if a GC happens, then the java_thread oop
1724
  // will not be visited by GC.
1725
  Threads::add(this);
1726
  // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
1727
  // on a ThreadsList. We don't want to wait for the release when the
1728
  // Theads_lock is dropped somewhere in the caller since the JavaThread*
1729
  // is already visible to JVM/TI via the ThreadsList.
1730
  java_lang_Thread::release_set_thread(thread_oop(), this);
1731
}
1732

1733
oop JavaThread::current_park_blocker() {
1734
  // Support for JSR-166 locks
1735
  oop thread_oop = threadObj();
1736
  if (thread_oop != nullptr) {
1737
    return java_lang_Thread::park_blocker(thread_oop);
1738
  }
1739
  return nullptr;
1740
}
1741

1742
// Print current stack trace for checked JNI warnings and JNI fatal errors.
1743
// This is the external format, selecting the platform or vthread
1744
// as applicable, and allowing for a native-only stack.
1745
void JavaThread::print_jni_stack() {
1746
  assert(this == JavaThread::current(), "Can't print stack of other threads");
1747
  if (!has_last_Java_frame()) {
1748
    ResourceMark rm(this);
1749
    char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
1750
    if (buf == nullptr) {
1751
      tty->print_cr("Unable to print native stack - out of memory");
1752
      return;
1753
    }
1754
    address lastpc = nullptr;
1755
    if (os::platform_print_native_stack(tty, nullptr, buf, O_BUFLEN, lastpc)) {
1756
      // We have printed the native stack in platform-specific code,
1757
      // so nothing else to do in this case.
1758
    } else {
1759
      frame f = os::current_frame();
1760
      VMError::print_native_stack(tty, f, this, true /*print_source_info */,
1761
                                  -1 /* max stack */, buf, O_BUFLEN);
1762
    }
1763
  } else {
1764
    print_active_stack_on(tty);
1765
  }
1766
}
1767

1768
void JavaThread::print_stack_on(outputStream* st) {
1769
  if (!has_last_Java_frame()) return;
1770

1771
  Thread* current_thread = Thread::current();
1772
  ResourceMark rm(current_thread);
1773
  HandleMark hm(current_thread);
1774

1775
  RegisterMap reg_map(this,
1776
                      RegisterMap::UpdateMap::include,
1777
                      RegisterMap::ProcessFrames::include,
1778
                      RegisterMap::WalkContinuation::skip);
1779
  vframe* start_vf = platform_thread_last_java_vframe(&reg_map);
1780
  int count = 0;
1781
  for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1782
    if (f->is_java_frame()) {
1783
      javaVFrame* jvf = javaVFrame::cast(f);
1784
      java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1785

1786
      // Print out lock information
1787
      if (JavaMonitorsInStackTrace) {
1788
        jvf->print_lock_info_on(st, count);
1789
      }
1790
    } else {
1791
      // Ignore non-Java frames
1792
    }
1793

1794
    // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1795
    count++;
1796
    if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1797
  }
1798
}
1799

1800
void JavaThread::print_vthread_stack_on(outputStream* st) {
1801
  assert(is_vthread_mounted(), "Caller should have checked this");
1802
  assert(has_last_Java_frame(), "must be");
1803

1804
  Thread* current_thread = Thread::current();
1805
  ResourceMark rm(current_thread);
1806
  HandleMark hm(current_thread);
1807

1808
  RegisterMap reg_map(this,
1809
                      RegisterMap::UpdateMap::include,
1810
                      RegisterMap::ProcessFrames::include,
1811
                      RegisterMap::WalkContinuation::include);
1812
  ContinuationEntry* cont_entry = last_continuation();
1813
  vframe* start_vf = last_java_vframe(&reg_map);
1814
  int count = 0;
1815
  for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1816
    // Watch for end of vthread stack
1817
    if (Continuation::is_continuation_enterSpecial(f->fr())) {
1818
      assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), "");
1819
      if (cont_entry->is_virtual_thread()) {
1820
        break;
1821
      }
1822
      cont_entry = cont_entry->parent();
1823
    }
1824
    if (f->is_java_frame()) {
1825
      javaVFrame* jvf = javaVFrame::cast(f);
1826
      java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1827

1828
      // Print out lock information
1829
      if (JavaMonitorsInStackTrace) {
1830
        jvf->print_lock_info_on(st, count);
1831
      }
1832
    } else {
1833
      // Ignore non-Java frames
1834
    }
1835

1836
    // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1837
    count++;
1838
    if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1839
  }
1840
}
1841

1842
void JavaThread::print_active_stack_on(outputStream* st) {
1843
  if (is_vthread_mounted()) {
1844
    print_vthread_stack_on(st);
1845
  } else {
1846
    print_stack_on(st);
1847
  }
1848
}
1849

1850
#if INCLUDE_JVMTI
1851
// Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1852
JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1853
  set_jvmti_vthread(thread_oop);
1854

1855
  // unbind current JvmtiThreadState from JavaThread
1856
  JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1857

1858
  // bind new JvmtiThreadState to JavaThread
1859
  JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1860

1861
  // enable interp_only_mode for virtual or carrier thread if it has pending bit
1862
  JvmtiThreadState::process_pending_interp_only(this);
1863

1864
  return jvmti_thread_state();
1865
}
1866
#endif
1867

1868
// JVMTI PopFrame support
1869
void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1870
  assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments");
1871
  if (in_bytes(size_in_bytes) != 0) {
1872
    _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1873
    _popframe_preserved_args_size = in_bytes(size_in_bytes);
1874
    Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1875
  }
1876
}
1877

1878
void* JavaThread::popframe_preserved_args() {
1879
  return _popframe_preserved_args;
1880
}
1881

1882
ByteSize JavaThread::popframe_preserved_args_size() {
1883
  return in_ByteSize(_popframe_preserved_args_size);
1884
}
1885

1886
WordSize JavaThread::popframe_preserved_args_size_in_words() {
1887
  int sz = in_bytes(popframe_preserved_args_size());
1888
  assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1889
  return in_WordSize(sz / wordSize);
1890
}
1891

1892
void JavaThread::popframe_free_preserved_args() {
1893
  assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice");
1894
  FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1895
  _popframe_preserved_args = nullptr;
1896
  _popframe_preserved_args_size = 0;
1897
}
1898

1899
#ifndef PRODUCT
1900

1901
void JavaThread::trace_frames() {
1902
  tty->print_cr("[Describe stack]");
1903
  int frame_no = 1;
1904
  for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1905
    tty->print("  %d. ", frame_no++);
1906
    fst.current()->print_value_on(tty, this);
1907
    tty->cr();
1908
  }
1909
}
1910

1911
class PrintAndVerifyOopClosure: public OopClosure {
1912
 protected:
1913
  template <class T> inline void do_oop_work(T* p) {
1914
    oop obj = RawAccess<>::oop_load(p);
1915
    if (obj == nullptr) return;
1916
    tty->print(INTPTR_FORMAT ": ", p2i(p));
1917
    if (oopDesc::is_oop_or_null(obj)) {
1918
      if (obj->is_objArray()) {
1919
        tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1920
      } else {
1921
        obj->print();
1922
      }
1923
    } else {
1924
      tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1925
    }
1926
    tty->cr();
1927
  }
1928
 public:
1929
  virtual void do_oop(oop* p) { do_oop_work(p); }
1930
  virtual void do_oop(narrowOop* p)  { do_oop_work(p); }
1931
};
1932

1933
#ifdef ASSERT
1934
// Print or validate the layout of stack frames
1935
void JavaThread::print_frame_layout(int depth, bool validate_only) {
1936
  ResourceMark rm;
1937
  PreserveExceptionMark pm(this);
1938
  FrameValues values;
1939
  int frame_no = 0;
1940
  for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1941
    fst.current()->describe(values, ++frame_no, fst.register_map());
1942
    if (depth == frame_no) break;
1943
  }
1944
  Continuation::describe(values);
1945
  if (validate_only) {
1946
    values.validate();
1947
  } else {
1948
    tty->print_cr("[Describe stack layout]");
1949
    values.print(this);
1950
  }
1951
}
1952
#endif
1953

1954
void JavaThread::trace_stack_from(vframe* start_vf) {
1955
  ResourceMark rm;
1956
  int vframe_no = 1;
1957
  for (vframe* f = start_vf; f; f = f->sender()) {
1958
    if (f->is_java_frame()) {
1959
      javaVFrame::cast(f)->print_activation(vframe_no++);
1960
    } else {
1961
      f->print();
1962
    }
1963
    if (vframe_no > StackPrintLimit) {
1964
      tty->print_cr("...<more frames>...");
1965
      return;
1966
    }
1967
  }
1968
}
1969

1970

1971
void JavaThread::trace_stack() {
1972
  if (!has_last_Java_frame()) return;
1973
  Thread* current_thread = Thread::current();
1974
  ResourceMark rm(current_thread);
1975
  HandleMark hm(current_thread);
1976
  RegisterMap reg_map(this,
1977
                      RegisterMap::UpdateMap::include,
1978
                      RegisterMap::ProcessFrames::include,
1979
                      RegisterMap::WalkContinuation::skip);
1980
  trace_stack_from(last_java_vframe(&reg_map));
1981
}
1982

1983

1984
#endif // PRODUCT
1985

1986
// Slow-path increment of the held monitor counts. JNI locking is always
1987
// this slow-path.
1988
void JavaThread::inc_held_monitor_count(intx i, bool jni) {
1989
#ifdef SUPPORT_MONITOR_COUNT
1990
  assert(_held_monitor_count >= 0, "Must always be non-negative: " INTX_FORMAT, _held_monitor_count);
1991
  _held_monitor_count += i;
1992
  if (jni) {
1993
    assert(_jni_monitor_count >= 0, "Must always be non-negative: " INTX_FORMAT, _jni_monitor_count);
1994
    _jni_monitor_count += i;
1995
  }
1996
  assert(_held_monitor_count >= _jni_monitor_count, "Monitor count discrepancy detected - held count "
1997
         INTX_FORMAT " is less than JNI count " INTX_FORMAT, _held_monitor_count, _jni_monitor_count);
1998
#endif
1999
}
2000

2001
// Slow-path decrement of the held monitor counts. JNI unlocking is always
2002
// this slow-path.
2003
void JavaThread::dec_held_monitor_count(intx i, bool jni) {
2004
#ifdef SUPPORT_MONITOR_COUNT
2005
  _held_monitor_count -= i;
2006
  assert(_held_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _held_monitor_count);
2007
  if (jni) {
2008
    _jni_monitor_count -= i;
2009
    assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _jni_monitor_count);
2010
  }
2011
  // When a thread is detaching with still owned JNI monitors, the logic that releases
2012
  // the monitors doesn't know to set the "jni" flag and so the counts can get out of sync.
2013
  // So we skip this assert if the thread is exiting. Once all monitors are unlocked the
2014
  // JNI count is directly set to zero.
2015
  assert(_held_monitor_count >= _jni_monitor_count || is_exiting(), "Monitor count discrepancy detected - held count "
2016
         INTX_FORMAT " is less than JNI count " INTX_FORMAT, _held_monitor_count, _jni_monitor_count);
2017
#endif
2018
}
2019

2020
frame JavaThread::vthread_last_frame() {
2021
  assert (is_vthread_mounted(), "Virtual thread not mounted");
2022
  return last_frame();
2023
}
2024

2025
frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
2026
  const ContinuationEntry* entry = vthread_continuation();
2027
  guarantee (entry != nullptr, "Not a carrier thread");
2028
  frame f = entry->to_frame();
2029
  if (reg_map->process_frames()) {
2030
    entry->flush_stack_processing(this);
2031
  }
2032
  entry->update_register_map(reg_map);
2033
  return f.sender(reg_map);
2034
}
2035

2036
frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
2037
  return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
2038
}
2039

2040
javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
2041
  assert(reg_map != nullptr, "a map must be given");
2042
  for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
2043
    if (vf->is_java_frame()) return javaVFrame::cast(vf);
2044
  }
2045
  return nullptr;
2046
}
2047

2048
Klass* JavaThread::security_get_caller_class(int depth) {
2049
  ResetNoHandleMark rnhm;
2050
  HandleMark hm(Thread::current());
2051

2052
  vframeStream vfst(this);
2053
  vfst.security_get_caller_frame(depth);
2054
  if (!vfst.at_end()) {
2055
    return vfst.method()->method_holder();
2056
  }
2057
  return nullptr;
2058
}
2059

2060
// Internal convenience function for millisecond resolution sleeps.
2061
bool JavaThread::sleep(jlong millis) {
2062
  jlong nanos;
2063
  if (millis > max_jlong / NANOUNITS_PER_MILLIUNIT) {
2064
    // Conversion to nanos would overflow, saturate at max
2065
    nanos = max_jlong;
2066
  } else {
2067
    nanos = millis * NANOUNITS_PER_MILLIUNIT;
2068
  }
2069
  return sleep_nanos(nanos);
2070
}
2071

2072
// java.lang.Thread.sleep support
2073
// Returns true if sleep time elapsed as expected, and false
2074
// if the thread was interrupted.
2075
bool JavaThread::sleep_nanos(jlong nanos) {
2076
  assert(this == Thread::current(),  "thread consistency check");
2077
  assert(nanos >= 0, "nanos are in range");
2078

2079
  ParkEvent * const slp = this->_SleepEvent;
2080
  // Because there can be races with thread interruption sending an unpark()
2081
  // to the event, we explicitly reset it here to avoid an immediate return.
2082
  // The actual interrupt state will be checked before we park().
2083
  slp->reset();
2084
  // Thread interruption establishes a happens-before ordering in the
2085
  // Java Memory Model, so we need to ensure we synchronize with the
2086
  // interrupt state.
2087
  OrderAccess::fence();
2088

2089
  jlong prevtime = os::javaTimeNanos();
2090

2091
  jlong nanos_remaining = nanos;
2092

2093
  for (;;) {
2094
    // interruption has precedence over timing out
2095
    if (this->is_interrupted(true)) {
2096
      return false;
2097
    }
2098

2099
    if (nanos_remaining <= 0) {
2100
      return true;
2101
    }
2102

2103
    {
2104
      ThreadBlockInVM tbivm(this);
2105
      OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2106
      slp->park_nanos(nanos_remaining);
2107
    }
2108

2109
    // Update elapsed time tracking
2110
    jlong newtime = os::javaTimeNanos();
2111
    if (newtime - prevtime < 0) {
2112
      // time moving backwards, should only happen if no monotonic clock
2113
      // not a guarantee() because JVM should not abort on kernel/glibc bugs
2114
      assert(false,
2115
             "unexpected time moving backwards detected in JavaThread::sleep()");
2116
    } else {
2117
      nanos_remaining -= (newtime - prevtime);
2118
    }
2119
    prevtime = newtime;
2120
  }
2121
}
2122

2123
// Last thread running calls java.lang.Shutdown.shutdown()
2124
void JavaThread::invoke_shutdown_hooks() {
2125
  HandleMark hm(this);
2126

2127
  // We could get here with a pending exception, if so clear it now.
2128
  if (this->has_pending_exception()) {
2129
    this->clear_pending_exception();
2130
  }
2131

2132
  EXCEPTION_MARK;
2133
  Klass* shutdown_klass =
2134
    SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
2135
                                      THREAD);
2136
  if (shutdown_klass != nullptr) {
2137
    // SystemDictionary::resolve_or_null will return null if there was
2138
    // an exception.  If we cannot load the Shutdown class, just don't
2139
    // call Shutdown.shutdown() at all.  This will mean the shutdown hooks
2140
    // won't be run.  Note that if a shutdown hook was registered,
2141
    // the Shutdown class would have already been loaded
2142
    // (Runtime.addShutdownHook will load it).
2143
    JavaValue result(T_VOID);
2144
    JavaCalls::call_static(&result,
2145
                           shutdown_klass,
2146
                           vmSymbols::shutdown_name(),
2147
                           vmSymbols::void_method_signature(),
2148
                           THREAD);
2149
  }
2150
  CLEAR_PENDING_EXCEPTION;
2151
}
2152

2153
#ifndef PRODUCT
2154
void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
2155
   report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
2156
}
2157
#endif
2158

2159
// Helper function to create the java.lang.Thread object for a
2160
// VM-internal thread. The thread will have the given name, and be
2161
// a member of the "system" ThreadGroup.
2162
Handle JavaThread::create_system_thread_object(const char* name, TRAPS) {
2163
  Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2164

2165
  // Initialize thread_oop to put it into the system threadGroup.
2166
  // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2167
  Handle thread_group(THREAD, Universe::system_thread_group());
2168
  Handle thread_oop =
2169
    JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2170
                                      vmSymbols::threadgroup_string_void_signature(),
2171
                                      thread_group,
2172
                                      string,
2173
                                      CHECK_NH);
2174

2175
  return thread_oop;
2176
}
2177

2178
// Starts the target JavaThread as a daemon of the given priority, and
2179
// bound to the given java.lang.Thread instance.
2180
// The Threads_lock is held for the duration.
2181
void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2182
                                       Handle thread_oop, ThreadPriority prio) {
2183

2184
  assert(target->osthread() != nullptr, "target thread is not properly initialized");
2185

2186
  MutexLocker mu(current, Threads_lock);
2187

2188
  // Initialize the fields of the thread_oop first.
2189
  if (prio != NoPriority) {
2190
    java_lang_Thread::set_priority(thread_oop(), prio);
2191
    // Note: we don't call os::set_priority here. Possibly we should,
2192
    // else all threads should call it themselves when they first run.
2193
  }
2194

2195
  java_lang_Thread::set_daemon(thread_oop());
2196

2197
  // Now bind the thread_oop to the target JavaThread.
2198
  target->set_threadOopHandles(thread_oop());
2199

2200
  Threads::add(target); // target is now visible for safepoint/handshake
2201
  // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
2202
  // on a ThreadsList. We don't want to wait for the release when the
2203
  // Theads_lock is dropped when the 'mu' destructor is run since the
2204
  // JavaThread* is already visible to JVM/TI via the ThreadsList.
2205

2206
  assert(java_lang_Thread::thread(thread_oop()) == nullptr, "must not be alive");
2207
  java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now
2208
  Thread::start(target);
2209
}
2210

2211
void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2212
  // At this point it may be possible that no osthread was created for the
2213
  // JavaThread due to lack of resources. However, since this must work
2214
  // for critical system threads just check and abort if this fails.
2215
  if (thread->osthread() == nullptr) {
2216
    // This isn't really an OOM condition, but historically this is what
2217
    // we report.
2218
    vm_exit_during_initialization("java.lang.OutOfMemoryError",
2219
                                  os::native_thread_creation_failed_msg());
2220
  }
2221
}
2222

2223
void JavaThread::pretouch_stack() {
2224
  // Given an established java thread stack with usable area followed by
2225
  // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging
2226
  // from the current frame down to the start of the shadow zone.
2227
  const address end = _stack_overflow_state.shadow_zone_safe_limit();
2228
  if (is_in_full_stack(end)) {
2229
    char* p1 = (char*) alloca(1);
2230
    address here = (address) &p1;
2231
    if (is_in_full_stack(here) && here > end) {
2232
      size_t to_alloc = here - end;
2233
      char* p2 = (char*) alloca(to_alloc);
2234
      log_trace(os, thread)("Pretouching thread stack for " UINTX_FORMAT ": " RANGEFMT ".",
2235
                            (uintx) osthread()->thread_id(), RANGEFMTARGS(p2, to_alloc));
2236
      os::pretouch_memory(p2, p2 + to_alloc,
2237
                          NOT_AIX(os::vm_page_size()) AIX_ONLY(4096));
2238
    }
2239
  }
2240
}
2241

2242
// Deferred OopHandle release support.
2243

2244
class OopHandleList : public CHeapObj<mtInternal> {
2245
  static const int _count = 4;
2246
  OopHandle _handles[_count];
2247
  OopHandleList* _next;
2248
  int _index;
2249
 public:
2250
  OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2251
  void add(OopHandle h) {
2252
    assert(_index < _count, "too many additions");
2253
    _handles[_index++] = h;
2254
  }
2255
  ~OopHandleList() {
2256
    assert(_index == _count, "usage error");
2257
    for (int i = 0; i < _index; i++) {
2258
      _handles[i].release(JavaThread::thread_oop_storage());
2259
    }
2260
  }
2261
  OopHandleList* next() const { return _next; }
2262
};
2263

2264
OopHandleList* JavaThread::_oop_handle_list = nullptr;
2265

2266
// Called by the ServiceThread to do the work of releasing
2267
// the OopHandles.
2268
void JavaThread::release_oop_handles() {
2269
  OopHandleList* list;
2270
  {
2271
    MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2272
    list = _oop_handle_list;
2273
    _oop_handle_list = nullptr;
2274
  }
2275
  assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2276

2277
  while (list != nullptr) {
2278
    OopHandleList* l = list;
2279
    list = l->next();
2280
    delete l;
2281
  }
2282
}
2283

2284
// Add our OopHandles for later release.
2285
void JavaThread::add_oop_handles_for_release() {
2286
  MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2287
  OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2288
  new_head->add(_threadObj);
2289
  new_head->add(_vthread);
2290
  new_head->add(_jvmti_vthread);
2291
  new_head->add(_scopedValueCache);
2292
  _oop_handle_list = new_head;
2293
  Service_lock->notify_all();
2294
}
2295

Использование cookies

Мы используем файлы cookie в соответствии с Политикой конфиденциальности и Политикой использования cookies.

Нажимая кнопку «Принимаю», Вы даете АО «СберТех» согласие на обработку Ваших персональных данных в целях совершенствования нашего веб-сайта и Сервиса GitVerse, а также повышения удобства их использования.

Запретить использование cookies Вы можете самостоятельно в настройках Вашего браузера.