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/inlineKlass.hpp"
52 #include "oops/instanceKlass.hpp"
53 #include "oops/klass.inline.hpp"
54 #include "oops/oop.inline.hpp"
55 #include "oops/oopHandle.inline.hpp"
56 #include "oops/verifyOopClosure.hpp"
57 #include "prims/jvm_misc.hpp"
58 #include "prims/jvmtiDeferredUpdates.hpp"
59 #include "prims/jvmtiExport.hpp"
60 #include "prims/jvmtiThreadState.inline.hpp"
61 #include "runtime/atomic.hpp"
62 #include "runtime/continuation.hpp"
63 #include "runtime/continuationEntry.inline.hpp"
64 #include "runtime/continuationHelper.inline.hpp"
65 #include "runtime/deoptimization.hpp"
66 #include "runtime/frame.inline.hpp"
67 #include "runtime/handles.inline.hpp"
68 #include "runtime/handshake.hpp"
69 #include "runtime/interfaceSupport.inline.hpp"
70 #include "runtime/java.hpp"
71 #include "runtime/javaCalls.hpp"
72 #include "runtime/javaThread.inline.hpp"
73 #include "runtime/jniHandles.inline.hpp"
74 #include "runtime/lockStack.inline.hpp"
75 #include "runtime/mutexLocker.hpp"
76 #include "runtime/orderAccess.hpp"
77 #include "runtime/os.inline.hpp"
78 #include "runtime/osThread.hpp"
79 #include "runtime/safepoint.hpp"
80 #include "runtime/safepointMechanism.inline.hpp"
81 #include "runtime/safepointVerifiers.hpp"
82 #include "runtime/serviceThread.hpp"
83 #include "runtime/stackFrameStream.inline.hpp"
84 #include "runtime/stackWatermarkSet.hpp"
85 #include "runtime/synchronizer.hpp"
86 #include "runtime/threadCritical.hpp"
87 #include "runtime/threadSMR.inline.hpp"
88 #include "runtime/threadStatisticalInfo.hpp"
89 #include "runtime/threadWXSetters.inline.hpp"
90 #include "runtime/timer.hpp"
91 #include "runtime/timerTrace.hpp"
92 #include "runtime/vframe.inline.hpp"
93 #include "runtime/vframeArray.hpp"
94 #include "runtime/vframe_hp.hpp"
95 #include "runtime/vmThread.hpp"
96 #include "runtime/vmOperations.hpp"
97 #include "services/threadService.hpp"
98 #include "utilities/copy.hpp"
99 #include "utilities/defaultStream.hpp"
100 #include "utilities/dtrace.hpp"
101 #include "utilities/events.hpp"
102 #include "utilities/macros.hpp"
103 #include "utilities/preserveException.hpp"
104 #include "utilities/spinYield.hpp"
105 #include "utilities/vmError.hpp"
106 #if INCLUDE_JVMCI
107 #include "jvmci/jvmci.hpp"
108 #include "jvmci/jvmciEnv.hpp"
109 #endif
110 #if INCLUDE_JFR
111 #include "jfr/jfr.hpp"
112 #endif
113
114 // Set by os layer.
115 size_t JavaThread::_stack_size_at_create = 0;
116
117 #ifdef DTRACE_ENABLED
118
119 // Only bother with this argument setup if dtrace is available
120
121 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
122 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
123
124 #define DTRACE_THREAD_PROBE(probe, javathread) \
125 { \
126 ResourceMark rm(this); \
127 int len = 0; \
128 const char* name = (javathread)->name(); \
129 len = strlen(name); \
130 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
131 (char *) name, len, \
132 java_lang_Thread::thread_id((javathread)->threadObj()), \
133 (uintptr_t) (javathread)->osthread()->thread_id(), \
134 java_lang_Thread::is_daemon((javathread)->threadObj())); \
135 }
136
137 #else // ndef DTRACE_ENABLED
138
139 #define DTRACE_THREAD_PROBE(probe, javathread)
140
141 #endif // ndef DTRACE_ENABLED
142
143 void JavaThread::smr_delete() {
144 if (_on_thread_list) {
145 ThreadsSMRSupport::smr_delete(this);
146 } else {
147 delete this;
148 }
149 }
150
151 // Initialized by VMThread at vm_global_init
152 OopStorage* JavaThread::_thread_oop_storage = nullptr;
153
154 OopStorage* JavaThread::thread_oop_storage() {
155 assert(_thread_oop_storage != nullptr, "not yet initialized");
156 return _thread_oop_storage;
157 }
158
159 void JavaThread::set_threadOopHandles(oop p) {
160 assert(_thread_oop_storage != nullptr, "not yet initialized");
161 _threadObj = OopHandle(_thread_oop_storage, p);
162 _vthread = OopHandle(_thread_oop_storage, p);
163 _jvmti_vthread = OopHandle(_thread_oop_storage, p->is_a(vmClasses::BoundVirtualThread_klass()) ? p : nullptr);
164 _scopedValueCache = OopHandle(_thread_oop_storage, nullptr);
165 }
166
167 oop JavaThread::threadObj() const {
168 // Ideally we would verify the current thread is oop_safe when this is called, but as we can
169 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That
170 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS.
171 // Instead callers must verify oop safe access.
172 return _threadObj.resolve();
173 }
174
175 oop JavaThread::vthread() const {
176 return _vthread.resolve();
177 }
178
179 void JavaThread::set_vthread(oop p) {
180 assert(_thread_oop_storage != nullptr, "not yet initialized");
181 _vthread.replace(p);
182 }
183
184 oop JavaThread::jvmti_vthread() const {
185 return _jvmti_vthread.resolve();
186 }
187
188 void JavaThread::set_jvmti_vthread(oop p) {
189 assert(_thread_oop_storage != nullptr, "not yet initialized");
190 _jvmti_vthread.replace(p);
191 }
192
193 oop JavaThread::scopedValueCache() const {
194 return _scopedValueCache.resolve();
195 }
196
197 void JavaThread::set_scopedValueCache(oop p) {
198 if (!_scopedValueCache.is_empty()) { // i.e. if the OopHandle has been allocated
199 _scopedValueCache.replace(p);
200 } else {
201 assert(p == nullptr, "not yet initialized");
202 }
203 }
204
205 void JavaThread::clear_scopedValueBindings() {
206 set_scopedValueCache(nullptr);
207 oop vthread_oop = vthread();
208 // vthread may be null here if we get a VM error during startup,
209 // before the java.lang.Thread instance has been created.
210 if (vthread_oop != nullptr) {
211 java_lang_Thread::clear_scopedValueBindings(vthread_oop);
212 }
213 }
214
215 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
216 bool daemon, TRAPS) {
217 assert(thread_group.not_null(), "thread group should be specified");
218 assert(threadObj() == nullptr, "should only create Java thread object once");
219
220 InstanceKlass* ik = vmClasses::Thread_klass();
221 assert(ik->is_initialized(), "must be");
222 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
223
224 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
225 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
226 // constructor calls Thread.current(), which must be set here.
227 java_lang_Thread::set_thread(thread_oop(), this);
228 set_threadOopHandles(thread_oop());
229
230 JavaValue result(T_VOID);
231 if (thread_name != nullptr) {
232 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
233 // Thread gets assigned specified name and null target
234 JavaCalls::call_special(&result,
235 thread_oop,
236 ik,
237 vmSymbols::object_initializer_name(),
238 vmSymbols::threadgroup_string_void_signature(),
239 thread_group,
240 name,
241 CHECK);
242 } else {
243 // Thread gets assigned name "Thread-nnn" and null target
244 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
245 JavaCalls::call_special(&result,
246 thread_oop,
247 ik,
248 vmSymbols::object_initializer_name(),
249 vmSymbols::threadgroup_runnable_void_signature(),
250 thread_group,
251 Handle(),
252 CHECK);
253 }
254 os::set_priority(this, NormPriority);
255
256 if (daemon) {
257 java_lang_Thread::set_daemon(thread_oop());
258 }
259 }
260
261 // ======= JavaThread ========
262
263 #if INCLUDE_JVMCI
264
265 jlong* JavaThread::_jvmci_old_thread_counters;
266
267 static bool jvmci_counters_include(JavaThread* thread) {
268 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
269 }
270
271 void JavaThread::collect_counters(jlong* array, int length) {
272 assert(length == JVMCICounterSize, "wrong value");
273 for (int i = 0; i < length; i++) {
274 array[i] = _jvmci_old_thread_counters[i];
275 }
276 for (JavaThread* tp : ThreadsListHandle()) {
277 if (jvmci_counters_include(tp)) {
278 for (int i = 0; i < length; i++) {
279 array[i] += tp->_jvmci_counters[i];
280 }
281 }
282 }
283 }
284
285 // Attempt to enlarge the array for per thread counters.
286 static jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
287 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
288 if (new_counters == nullptr) {
289 return nullptr;
290 }
291 if (old_counters == nullptr) {
292 old_counters = new_counters;
293 memset(old_counters, 0, sizeof(jlong) * new_size);
294 } else {
295 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
296 new_counters[i] = old_counters[i];
297 }
298 if (new_size > current_size) {
299 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
300 }
301 FREE_C_HEAP_ARRAY(jlong, old_counters);
302 }
303 return new_counters;
304 }
305
306 // Attempt to enlarge the array for per thread counters.
307 bool JavaThread::resize_counters(int current_size, int new_size) {
308 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
309 if (new_counters == nullptr) {
310 return false;
311 } else {
312 _jvmci_counters = new_counters;
313 return true;
314 }
315 }
316
317 class VM_JVMCIResizeCounters : public VM_Operation {
318 private:
319 int _new_size;
320 bool _failed;
321
322 public:
323 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
324 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
325 bool allow_nested_vm_operations() const { return true; }
326 void doit() {
327 // Resize the old thread counters array
328 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
329 if (new_counters == nullptr) {
330 _failed = true;
331 return;
332 } else {
333 JavaThread::_jvmci_old_thread_counters = new_counters;
334 }
335
336 // Now resize each threads array
337 for (JavaThread* tp : ThreadsListHandle()) {
338 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
339 _failed = true;
340 break;
341 }
342 }
343 if (!_failed) {
344 JVMCICounterSize = _new_size;
345 }
346 }
347
348 bool failed() { return _failed; }
349 };
350
351 bool JavaThread::resize_all_jvmci_counters(int new_size) {
352 VM_JVMCIResizeCounters op(new_size);
353 VMThread::execute(&op);
354 return !op.failed();
355 }
356
357 #endif // INCLUDE_JVMCI
358
359 #ifdef ASSERT
360 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
361 void JavaThread::check_possible_safepoint() {
362 if (_no_safepoint_count > 0) {
363 print_owned_locks();
364 assert(false, "Possible safepoint reached by thread that does not allow it");
365 }
366 #ifdef CHECK_UNHANDLED_OOPS
367 // Clear unhandled oops in JavaThreads so we get a crash right away.
368 clear_unhandled_oops();
369 #endif // CHECK_UNHANDLED_OOPS
370
371 // Macos/aarch64 should be in the right state for safepoint (e.g.
372 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely
373 // happens in practice, making such issues hard to find and reproduce.
374 #if defined(__APPLE__) && defined(AARCH64)
375 if (AssertWXAtThreadSync) {
376 assert_wx_state(WXWrite);
377 }
378 #endif
379 }
380
381 void JavaThread::check_for_valid_safepoint_state() {
382 // Don't complain if running a debugging command.
383 if (DebuggingContext::is_enabled()) return;
384
385 // Check NoSafepointVerifier, which is implied by locks taken that can be
386 // shared with the VM thread. This makes sure that no locks with allow_vm_block
387 // are held.
388 check_possible_safepoint();
389
390 if (thread_state() != _thread_in_vm) {
391 fatal("LEAF method calling lock?");
392 }
393
394 if (GCALotAtAllSafepoints) {
395 // We could enter a safepoint here and thus have a gc
396 InterfaceSupport::check_gc_alot();
397 }
398 }
399 #endif // ASSERT
400
401 // A JavaThread is a normal Java thread
402
403 JavaThread::JavaThread() :
404 // Initialize fields
405
406 _on_thread_list(false),
407 DEBUG_ONLY(_java_call_counter(0) COMMA)
408 _entry_point(nullptr),
409 _deopt_mark(nullptr),
410 _deopt_nmethod(nullptr),
411 _vframe_array_head(nullptr),
412 _vframe_array_last(nullptr),
413 _jvmti_deferred_updates(nullptr),
414 _callee_target(nullptr),
415 _vm_result(nullptr),
416 _vm_result_2(nullptr),
417
418 _current_pending_monitor(nullptr),
419 _current_pending_monitor_is_from_java(true),
420 _current_waiting_monitor(nullptr),
421 _active_handles(nullptr),
422 _free_handle_block(nullptr),
423 _Stalled(0),
424
425 _monitor_chunks(nullptr),
426
427 _suspend_flags(0),
428
429 _thread_state(_thread_new),
430 _saved_exception_pc(nullptr),
431 #ifdef ASSERT
432 _no_safepoint_count(0),
433 _visited_for_critical_count(false),
434 #endif
435
436 _terminated(_not_terminated),
437 _in_deopt_handler(0),
438 _doing_unsafe_access(false),
439 _do_not_unlock_if_synchronized(false),
440 #if INCLUDE_JVMTI
441 _carrier_thread_suspended(false),
442 _is_in_VTMS_transition(false),
443 _is_in_tmp_VTMS_transition(false),
444 _is_disable_suspend(false),
445 #ifdef ASSERT
446 _is_VTMS_transition_disabler(false),
447 #endif
448 #endif
449 _jni_attach_state(_not_attaching_via_jni),
450 #if INCLUDE_JVMCI
451 _pending_deoptimization(-1),
452 _pending_monitorenter(false),
453 _pending_transfer_to_interpreter(false),
454 _in_retryable_allocation(false),
455 _pending_failed_speculation(0),
456 _jvmci{nullptr},
457 _libjvmci_runtime(nullptr),
458 _jvmci_counters(nullptr),
459 _jvmci_reserved0(0),
460 _jvmci_reserved1(0),
461 _jvmci_reserved_oop0(nullptr),
462 #endif // INCLUDE_JVMCI
463
464 _exception_oop(oop()),
465 _exception_pc(0),
466 _exception_handler_pc(0),
467 _is_method_handle_return(0),
468
469 _jni_active_critical(0),
470 _pending_jni_exception_check_fn(nullptr),
471 _depth_first_number(0),
472
473 // JVMTI PopFrame support
474 _popframe_condition(popframe_inactive),
475 _frames_to_pop_failed_realloc(0),
476
477 _cont_entry(nullptr),
478 _cont_fastpath(0),
479 _cont_fastpath_thread_state(1),
480 _held_monitor_count(0),
481 _jni_monitor_count(0),
482
483 _handshake(this),
484
485 _popframe_preserved_args(nullptr),
486 _popframe_preserved_args_size(0),
487
488 _jvmti_thread_state(nullptr),
489 _interp_only_mode(0),
490 _should_post_on_exceptions_flag(JNI_FALSE),
491 _thread_stat(new ThreadStatistics()),
492
493 _parker(),
494
495 _class_to_be_initialized(nullptr),
496
497 _SleepEvent(ParkEvent::Allocate(this)),
498
499 _lock_stack(this) {
500 set_jni_functions(jni_functions());
501
502 #if INCLUDE_JVMCI
503 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
504 if (JVMCICounterSize > 0) {
505 resize_counters(0, (int) JVMCICounterSize);
506 }
507 #endif // INCLUDE_JVMCI
508
509 // Setup safepoint state info for this thread
510 ThreadSafepointState::create(this);
511
512 SafepointMechanism::initialize_header(this);
513
514 set_requires_cross_modify_fence(false);
515
516 pd_initialize();
517 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
518 }
519
520 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
521 if (is_attaching_via_jni) {
522 _jni_attach_state = _attaching_via_jni;
523 }
524 }
525
526
527 // interrupt support
528
529 void JavaThread::interrupt() {
530 // All callers should have 'this' thread protected by a
531 // ThreadsListHandle so that it cannot terminate and deallocate
532 // itself.
533 debug_only(check_for_dangling_thread_pointer(this);)
534
535 // For Windows _interrupt_event
536 WINDOWS_ONLY(osthread()->set_interrupted(true);)
537
538 // For Thread.sleep
539 _SleepEvent->unpark();
540
541 // For JSR166 LockSupport.park
542 parker()->unpark();
543
544 // For ObjectMonitor and JvmtiRawMonitor
545 _ParkEvent->unpark();
546 }
547
548
549 bool JavaThread::is_interrupted(bool clear_interrupted) {
550 debug_only(check_for_dangling_thread_pointer(this);)
551
552 if (_threadObj.peek() == nullptr) {
553 // If there is no j.l.Thread then it is impossible to have
554 // been interrupted. We can find null during VM initialization
555 // or when a JNI thread is still in the process of attaching.
556 // In such cases this must be the current thread.
557 assert(this == Thread::current(), "invariant");
558 return false;
559 }
560
561 bool interrupted = java_lang_Thread::interrupted(threadObj());
562
563 // NOTE that since there is no "lock" around the interrupt and
564 // is_interrupted operations, there is the possibility that the
565 // interrupted flag will be "false" but that the
566 // low-level events will be in the signaled state. This is
567 // intentional. The effect of this is that Object.wait() and
568 // LockSupport.park() will appear to have a spurious wakeup, which
569 // is allowed and not harmful, and the possibility is so rare that
570 // it is not worth the added complexity to add yet another lock.
571 // For the sleep event an explicit reset is performed on entry
572 // to JavaThread::sleep, so there is no early return. It has also been
573 // recommended not to put the interrupted flag into the "event"
574 // structure because it hides the issue.
575 // Also, because there is no lock, we must only clear the interrupt
576 // state if we are going to report that we were interrupted; otherwise
577 // an interrupt that happens just after we read the field would be lost.
578 if (interrupted && clear_interrupted) {
579 assert(this == Thread::current(), "only the current thread can clear");
580 java_lang_Thread::set_interrupted(threadObj(), false);
581 WINDOWS_ONLY(osthread()->set_interrupted(false);)
582 }
583
584 return interrupted;
585 }
586
587 void JavaThread::block_if_vm_exited() {
588 if (_terminated == _vm_exited) {
589 // _vm_exited is set at safepoint, and Threads_lock is never released
590 // so we will block here forever.
591 // Here we can be doing a jump from a safe state to an unsafe state without
592 // proper transition, but it happens after the final safepoint has begun so
593 // this jump won't cause any safepoint problems.
594 set_thread_state(_thread_in_vm);
595 Threads_lock->lock();
596 ShouldNotReachHere();
597 }
598 }
599
600 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
601 _jni_attach_state = _not_attaching_via_jni;
602 set_entry_point(entry_point);
603 // Create the native thread itself.
604 // %note runtime_23
605 os::ThreadType thr_type = os::java_thread;
606 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
607 os::java_thread;
608 os::create_thread(this, thr_type, stack_sz);
609 // The _osthread may be null here because we ran out of memory (too many threads active).
610 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
611 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
612 // the exception consists of creating the exception object & initializing it, initialization
613 // will leave the VM via a JavaCall and then all locks must be unlocked).
614 //
615 // The thread is still suspended when we reach here. Thread must be explicit started
616 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
617 // by calling Threads:add. The reason why this is not done here, is because the thread
618 // object must be fully initialized (take a look at JVM_Start)
619 }
620
621 JavaThread::~JavaThread() {
622
623 // Enqueue OopHandles for release by the service thread.
624 add_oop_handles_for_release();
625
626 // Return the sleep event to the free list
627 ParkEvent::Release(_SleepEvent);
628 _SleepEvent = nullptr;
629
630 // Free any remaining previous UnrollBlock
631 vframeArray* old_array = vframe_array_last();
632
633 if (old_array != nullptr) {
634 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
635 old_array->set_unroll_block(nullptr);
636 delete old_info;
637 delete old_array;
638 }
639
640 JvmtiDeferredUpdates* updates = deferred_updates();
641 if (updates != nullptr) {
642 // This can only happen if thread is destroyed before deoptimization occurs.
643 assert(updates->count() > 0, "Updates holder not deleted");
644 // free deferred updates.
645 delete updates;
646 set_deferred_updates(nullptr);
647 }
648
649 // All Java related clean up happens in exit
650 ThreadSafepointState::destroy(this);
651 if (_thread_stat != nullptr) delete _thread_stat;
652
653 #if INCLUDE_JVMCI
654 if (JVMCICounterSize > 0) {
655 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
656 }
657 #endif // INCLUDE_JVMCI
658 }
659
660
661 // First JavaThread specific code executed by a new Java thread.
662 void JavaThread::pre_run() {
663 // empty - see comments in run()
664 }
665
666 // The main routine called by a new Java thread. This isn't overridden
667 // by subclasses, instead different subclasses define a different "entry_point"
668 // which defines the actual logic for that kind of thread.
669 void JavaThread::run() {
670 // initialize thread-local alloc buffer related fields
671 initialize_tlab();
672
673 _stack_overflow_state.create_stack_guard_pages();
674
675 cache_global_variables();
676
677 // Thread is now sufficiently initialized to be handled by the safepoint code as being
678 // in the VM. Change thread state from _thread_new to _thread_in_vm
679 assert(this->thread_state() == _thread_new, "wrong thread state");
680 set_thread_state(_thread_in_vm);
681
682 // Before a thread is on the threads list it is always safe, so after leaving the
683 // _thread_new we should emit a instruction barrier. The distance to modified code
684 // from here is probably far enough, but this is consistent and safe.
685 OrderAccess::cross_modify_fence();
686
687 assert(JavaThread::current() == this, "sanity check");
688 assert(!Thread::current()->owns_locks(), "sanity check");
689
690 DTRACE_THREAD_PROBE(start, this);
691
692 // This operation might block. We call that after all safepoint checks for a new thread has
693 // been completed.
694 set_active_handles(JNIHandleBlock::allocate_block());
695
696 if (JvmtiExport::should_post_thread_life()) {
697 JvmtiExport::post_thread_start(this);
698
699 }
700
701 if (AlwaysPreTouchStacks) {
702 pretouch_stack();
703 }
704
705 // We call another function to do the rest so we are sure that the stack addresses used
706 // from there will be lower than the stack base just computed.
707 thread_main_inner();
708 }
709
710 void JavaThread::thread_main_inner() {
711 assert(JavaThread::current() == this, "sanity check");
712 assert(_threadObj.peek() != nullptr, "just checking");
713
714 // Execute thread entry point unless this thread has a pending exception.
715 // Note: Due to JVMTI StopThread we can have pending exceptions already!
716 if (!this->has_pending_exception()) {
717 {
718 ResourceMark rm(this);
719 this->set_native_thread_name(this->name());
720 }
721 HandleMark hm(this);
722 this->entry_point()(this, this);
723 }
724
725 DTRACE_THREAD_PROBE(stop, this);
726
727 // Cleanup is handled in post_run()
728 }
729
730 // Shared teardown for all JavaThreads
731 void JavaThread::post_run() {
732 this->exit(false);
733 this->unregister_thread_stack_with_NMT();
734 // Defer deletion to here to ensure 'this' is still referenceable in call_run
735 // for any shared tear-down.
736 this->smr_delete();
737 }
738
739 static void ensure_join(JavaThread* thread) {
740 // We do not need to grab the Threads_lock, since we are operating on ourself.
741 Handle threadObj(thread, thread->threadObj());
742 assert(threadObj.not_null(), "java thread object must exist");
743 ObjectLocker lock(threadObj, thread);
744 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
745 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
746 // Clear the native thread instance - this makes isAlive return false and allows the join()
747 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model
748 // requirements.
749 assert(java_lang_Thread::thread(threadObj()) == thread, "must be alive");
750 java_lang_Thread::release_set_thread(threadObj(), nullptr);
751 lock.notify_all(thread);
752 // Ignore pending exception, since we are exiting anyway
753 thread->clear_pending_exception();
754 }
755
756 static bool is_daemon(oop threadObj) {
757 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj));
758 }
759
760 // For any new cleanup additions, please check to see if they need to be applied to
761 // cleanup_failed_attach_current_thread as well.
762 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
763 assert(this == JavaThread::current(), "thread consistency check");
764 assert(!is_exiting(), "should not be exiting or terminated already");
765
766 elapsedTimer _timer_exit_phase1;
767 elapsedTimer _timer_exit_phase2;
768 elapsedTimer _timer_exit_phase3;
769 elapsedTimer _timer_exit_phase4;
770
771 if (log_is_enabled(Debug, os, thread, timer)) {
772 _timer_exit_phase1.start();
773 }
774
775 HandleMark hm(this);
776 Handle uncaught_exception(this, this->pending_exception());
777 this->clear_pending_exception();
778 Handle threadObj(this, this->threadObj());
779 assert(threadObj.not_null(), "Java thread object should be created");
780
781 if (!destroy_vm) {
782 if (uncaught_exception.not_null()) {
783 EXCEPTION_MARK;
784 // Call method Thread.dispatchUncaughtException().
785 Klass* thread_klass = vmClasses::Thread_klass();
786 JavaValue result(T_VOID);
787 JavaCalls::call_virtual(&result,
788 threadObj, thread_klass,
789 vmSymbols::dispatchUncaughtException_name(),
790 vmSymbols::throwable_void_signature(),
791 uncaught_exception,
792 THREAD);
793 if (HAS_PENDING_EXCEPTION) {
794 ResourceMark rm(this);
795 jio_fprintf(defaultStream::error_stream(),
796 "\nException: %s thrown from the UncaughtExceptionHandler"
797 " in thread \"%s\"\n",
798 pending_exception()->klass()->external_name(),
799 name());
800 CLEAR_PENDING_EXCEPTION;
801 }
802 }
803
804 if (!is_Compiler_thread()) {
805 // We have finished executing user-defined Java code and now have to do the
806 // implementation specific clean-up by calling Thread.exit(). We prevent any
807 // asynchronous exceptions from being delivered while in Thread.exit()
808 // to ensure the clean-up is not corrupted.
809 NoAsyncExceptionDeliveryMark _no_async(this);
810
811 EXCEPTION_MARK;
812 JavaValue result(T_VOID);
813 Klass* thread_klass = vmClasses::Thread_klass();
814 JavaCalls::call_virtual(&result,
815 threadObj, thread_klass,
816 vmSymbols::exit_method_name(),
817 vmSymbols::void_method_signature(),
818 THREAD);
819 CLEAR_PENDING_EXCEPTION;
820 }
821
822 // notify JVMTI
823 if (JvmtiExport::should_post_thread_life()) {
824 JvmtiExport::post_thread_end(this);
825 }
826 } else {
827 // before_exit() has already posted JVMTI THREAD_END events
828 }
829
830 // Cleanup any pending async exception now since we cannot access oops after
831 // BarrierSet::barrier_set()->on_thread_detach() has been executed.
832 if (has_async_exception_condition()) {
833 handshake_state()->clean_async_exception_operation();
834 }
835
836 // The careful dance between thread suspension and exit is handled here.
837 // Since we are in thread_in_vm state and suspension is done with handshakes,
838 // we can just put in the exiting state and it will be correctly handled.
839 // Also, no more async exceptions will be added to the queue after this point.
840 set_terminated(_thread_exiting);
841 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
842
843 if (log_is_enabled(Debug, os, thread, timer)) {
844 _timer_exit_phase1.stop();
845 _timer_exit_phase2.start();
846 }
847
848 // Capture daemon status before the thread is marked as terminated.
849 bool daemon = is_daemon(threadObj());
850
851 // Notify waiters on thread object. This has to be done after exit() is called
852 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
853 // group should have the destroyed bit set before waiters are notified).
854 ensure_join(this);
855 assert(!this->has_pending_exception(), "ensure_join should have cleared");
856
857 if (log_is_enabled(Debug, os, thread, timer)) {
858 _timer_exit_phase2.stop();
859 _timer_exit_phase3.start();
860 }
861 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
862 // held by this thread must be released. The spec does not distinguish
863 // between JNI-acquired and regular Java monitors. We can only see
864 // regular Java monitors here if monitor enter-exit matching is broken.
865 //
866 // ensure_join() ignores IllegalThreadStateExceptions, and so does
867 // ObjectSynchronizer::release_monitors_owned_by_thread().
868 if (exit_type == jni_detach) {
869 // Sanity check even though JNI DetachCurrentThread() would have
870 // returned JNI_ERR if there was a Java frame. JavaThread exit
871 // should be done executing Java code by the time we get here.
872 assert(!this->has_last_Java_frame(),
873 "should not have a Java frame when detaching or exiting");
874 ObjectSynchronizer::release_monitors_owned_by_thread(this);
875 assert(!this->has_pending_exception(), "release_monitors should have cleared");
876 }
877
878 // Since above code may not release JNI monitors and if someone forgot to do an
879 // JNI monitorexit, held count should be equal jni count.
880 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach).
881 assert(held_monitor_count() == jni_monitor_count(),
882 "held monitor count should be equal to jni: " INTX_FORMAT " != " INTX_FORMAT,
883 held_monitor_count(), jni_monitor_count());
884 if (CheckJNICalls && jni_monitor_count() > 0) {
885 // We would like a fatal here, but due to we never checked this before there
886 // is a lot of tests which breaks, even with an error log.
887 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.",
888 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id());
889 }
890
891 // These things needs to be done while we are still a Java Thread. Make sure that thread
892 // is in a consistent state, in case GC happens
893 JFR_ONLY(Jfr::on_thread_exit(this);)
894
895 if (active_handles() != nullptr) {
896 JNIHandleBlock* block = active_handles();
897 set_active_handles(nullptr);
898 JNIHandleBlock::release_block(block);
899 }
900
901 if (free_handle_block() != nullptr) {
902 JNIHandleBlock* block = free_handle_block();
903 set_free_handle_block(nullptr);
904 JNIHandleBlock::release_block(block);
905 }
906
907 // These have to be removed while this is still a valid thread.
908 _stack_overflow_state.remove_stack_guard_pages();
909
910 if (UseTLAB) {
911 tlab().retire();
912 }
913
914 if (JvmtiEnv::environments_might_exist()) {
915 JvmtiExport::cleanup_thread(this);
916 }
917
918 // We need to cache the thread name for logging purposes below as once
919 // we have called on_thread_detach this thread must not access any oops.
920 char* thread_name = nullptr;
921 if (log_is_enabled(Debug, os, thread, timer)) {
922 ResourceMark rm(this);
923 thread_name = os::strdup(name());
924 }
925
926 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
927 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
928 os::current_thread_id());
929
930 if (log_is_enabled(Debug, os, thread, timer)) {
931 _timer_exit_phase3.stop();
932 _timer_exit_phase4.start();
933 }
934
935 #if INCLUDE_JVMCI
936 if (JVMCICounterSize > 0) {
937 if (jvmci_counters_include(this)) {
938 for (int i = 0; i < JVMCICounterSize; i++) {
939 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
940 }
941 }
942 }
943 #endif // INCLUDE_JVMCI
944
945 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
946 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
947 Threads::remove(this, daemon);
948
949 if (log_is_enabled(Debug, os, thread, timer)) {
950 _timer_exit_phase4.stop();
951 log_debug(os, thread, timer)("name='%s'"
952 ", exit-phase1=" JLONG_FORMAT
953 ", exit-phase2=" JLONG_FORMAT
954 ", exit-phase3=" JLONG_FORMAT
955 ", exit-phase4=" JLONG_FORMAT,
956 thread_name,
957 _timer_exit_phase1.milliseconds(),
958 _timer_exit_phase2.milliseconds(),
959 _timer_exit_phase3.milliseconds(),
960 _timer_exit_phase4.milliseconds());
961 os::free(thread_name);
962 }
963 }
964
965 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
966 if (active_handles() != nullptr) {
967 JNIHandleBlock* block = active_handles();
968 set_active_handles(nullptr);
969 JNIHandleBlock::release_block(block);
970 }
971
972 if (free_handle_block() != nullptr) {
973 JNIHandleBlock* block = free_handle_block();
974 set_free_handle_block(nullptr);
975 JNIHandleBlock::release_block(block);
976 }
977
978 // These have to be removed while this is still a valid thread.
979 _stack_overflow_state.remove_stack_guard_pages();
980
981 if (UseTLAB) {
982 tlab().retire();
983 }
984
985 Threads::remove(this, is_daemon);
986 this->smr_delete();
987 }
988
989 JavaThread* JavaThread::active() {
990 Thread* thread = Thread::current();
991 if (thread->is_Java_thread()) {
992 return JavaThread::cast(thread);
993 } else {
994 assert(thread->is_VM_thread(), "this must be a vm thread");
995 VM_Operation* op = ((VMThread*) thread)->vm_operation();
996 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread());
997 return ret;
998 }
999 }
1000
1001 bool JavaThread::is_lock_owned(address adr) const {
1002 assert(LockingMode != LM_LIGHTWEIGHT, "should not be called with new lightweight locking");
1003 if (Thread::is_lock_owned(adr)) return true;
1004
1005 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1006 if (chunk->contains(adr)) return true;
1007 }
1008
1009 return false;
1010 }
1011
1012 oop JavaThread::exception_oop() const {
1013 return Atomic::load(&_exception_oop);
1014 }
1015
1016 void JavaThread::set_exception_oop(oop o) {
1017 Atomic::store(&_exception_oop, o);
1018 }
1019
1020 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1021 chunk->set_next(monitor_chunks());
1022 set_monitor_chunks(chunk);
1023 }
1024
1025 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1026 guarantee(monitor_chunks() != nullptr, "must be non empty");
1027 if (monitor_chunks() == chunk) {
1028 set_monitor_chunks(chunk->next());
1029 } else {
1030 MonitorChunk* prev = monitor_chunks();
1031 while (prev->next() != chunk) prev = prev->next();
1032 prev->set_next(chunk->next());
1033 }
1034 }
1035
1036 void JavaThread::handle_special_runtime_exit_condition() {
1037 if (is_obj_deopt_suspend()) {
1038 frame_anchor()->make_walkable();
1039 wait_for_object_deoptimization();
1040 }
1041 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1042 }
1043
1044
1045 // Asynchronous exceptions support
1046 //
1047 void JavaThread::handle_async_exception(oop java_throwable) {
1048 assert(java_throwable != nullptr, "should have an _async_exception to throw");
1049 assert(!is_at_poll_safepoint(), "should have never called this method");
1050
1051 if (has_last_Java_frame()) {
1052 frame f = last_frame();
1053 if (f.is_runtime_frame()) {
1054 // If the topmost frame is a runtime stub, then we are calling into
1055 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1056 // must deoptimize the caller before continuing, as the compiled exception
1057 // handler table may not be valid.
1058 RegisterMap reg_map(this,
1059 RegisterMap::UpdateMap::skip,
1060 RegisterMap::ProcessFrames::include,
1061 RegisterMap::WalkContinuation::skip);
1062 frame compiled_frame = f.sender(®_map);
1063 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1064 Deoptimization::deoptimize(this, compiled_frame);
1065 }
1066 }
1067 }
1068
1069 // We cannot call Exceptions::_throw(...) here because we cannot block
1070 set_pending_exception(java_throwable, __FILE__, __LINE__);
1071
1072 clear_scopedValueBindings();
1073
1074 LogTarget(Info, exceptions) lt;
1075 if (lt.is_enabled()) {
1076 ResourceMark rm;
1077 LogStream ls(lt);
1078 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1079 if (has_last_Java_frame()) {
1080 frame f = last_frame();
1081 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1082 }
1083 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1084 }
1085 }
1086
1087 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1088 // Do not throw asynchronous exceptions against the compiler thread
1089 // or if the thread is already exiting.
1090 if (!can_call_java() || is_exiting()) {
1091 delete aeh;
1092 return;
1093 }
1094
1095 oop exception = aeh->exception();
1096 Handshake::execute(aeh, this); // Install asynchronous handshake
1097
1098 ResourceMark rm;
1099 if (log_is_enabled(Info, exceptions)) {
1100 log_info(exceptions)("Pending Async. exception installed of type: %s",
1101 InstanceKlass::cast(exception->klass())->external_name());
1102 }
1103 // for AbortVMOnException flag
1104 Exceptions::debug_check_abort(exception->klass()->external_name());
1105
1106 oop vt_oop = vthread();
1107 if (vt_oop == nullptr || !vt_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1108 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1109 java_lang_Thread::set_interrupted(threadObj(), true);
1110 this->interrupt();
1111 }
1112 }
1113
1114 class InstallAsyncExceptionHandshake : public HandshakeClosure {
1115 AsyncExceptionHandshake* _aeh;
1116 public:
1117 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1118 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1119 ~InstallAsyncExceptionHandshake() {
1120 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh.
1121 delete _aeh;
1122 }
1123 void do_thread(Thread* thr) {
1124 JavaThread* target = JavaThread::cast(thr);
1125 target->install_async_exception(_aeh);
1126 _aeh = nullptr;
1127 }
1128 };
1129
1130 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1131 OopHandle e(Universe::vm_global(), java_throwable);
1132 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1133 Handshake::execute(&iaeh, target);
1134 }
1135
1136 #if INCLUDE_JVMTI
1137 void JavaThread::set_is_in_VTMS_transition(bool val) {
1138 _is_in_VTMS_transition = val;
1139 }
1140
1141 #ifdef ASSERT
1142 void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1143 _is_VTMS_transition_disabler = val;
1144 }
1145 #endif
1146 #endif
1147
1148 // External suspension mechanism.
1149 //
1150 // Guarantees on return (for a valid target thread):
1151 // - Target thread will not execute any new bytecode.
1152 // - Target thread will not enter any new monitors.
1153 //
1154 bool JavaThread::java_suspend() {
1155 #if INCLUDE_JVMTI
1156 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1157 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1158 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1159 #endif
1160
1161 guarantee(Thread::is_JavaThread_protected(/* target */ this),
1162 "target JavaThread is not protected in calling context.");
1163 return this->handshake_state()->suspend();
1164 }
1165
1166 bool JavaThread::java_resume() {
1167 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1168 "missing ThreadsListHandle in calling context.");
1169 return this->handshake_state()->resume();
1170 }
1171
1172 // Wait for another thread to perform object reallocation and relocking on behalf of
1173 // this thread. The current thread is required to change to _thread_blocked in order
1174 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1175 // handshake safe, the other thread can complete the handshake used to synchronize
1176 // with this thread and then perform the reallocation and relocking.
1177 // See EscapeBarrier::sync_and_suspend_*()
1178
1179 void JavaThread::wait_for_object_deoptimization() {
1180 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1181 assert(this == Thread::current(), "invariant");
1182
1183 bool spin_wait = os::is_MP();
1184 do {
1185 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1186 // Wait for object deoptimization if requested.
1187 if (spin_wait) {
1188 // A single deoptimization is typically very short. Microbenchmarks
1189 // showed 5% better performance when spinning.
1190 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1191 SpinYield spin(spin_limit);
1192 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1193 spin.wait();
1194 }
1195 // Spin just once
1196 spin_wait = false;
1197 } else {
1198 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1199 if (is_obj_deopt_suspend()) {
1200 ml.wait();
1201 }
1202 }
1203 // A handshake for obj. deoptimization suspend could have been processed so
1204 // we must check after processing.
1205 } while (is_obj_deopt_suspend());
1206 }
1207
1208 #ifdef ASSERT
1209 // Verify the JavaThread has not yet been published in the Threads::list, and
1210 // hence doesn't need protection from concurrent access at this stage.
1211 void JavaThread::verify_not_published() {
1212 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1213 // since an unpublished JavaThread doesn't participate in the
1214 // Thread-SMR protocol for keeping a ThreadsList alive.
1215 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1216 }
1217 #endif
1218
1219 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1220 // pending, when _suspend_flags is non-zero or when we need to process a stack
1221 // watermark. Also check for pending async exceptions (except unsafe access error).
1222 // Note only the native==>Java barriers can call this function when thread state
1223 // is _thread_in_native_trans.
1224 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1225 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1226 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1227
1228 thread->set_thread_state(_thread_in_vm);
1229
1230 // Enable WXWrite: called directly from interpreter native wrapper.
1231 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1232
1233 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1234
1235 // After returning from native, it could be that the stack frames are not
1236 // yet safe to use. We catch such situations in the subsequent stack watermark
1237 // barrier, which will trap unsafe stack frames.
1238 StackWatermarkSet::before_unwind(thread);
1239 }
1240
1241 #ifndef PRODUCT
1242 // Deoptimization
1243 // Function for testing deoptimization
1244 void JavaThread::deoptimize() {
1245 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1246 bool deopt = false; // Dump stack only if a deopt actually happens.
1247 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1248 // Iterate over all frames in the thread and deoptimize
1249 for (; !fst.is_done(); fst.next()) {
1250 if (fst.current()->can_be_deoptimized()) {
1251
1252 if (only_at) {
1253 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1254 // consists of comma or carriage return separated numbers so
1255 // search for the current bci in that string.
1256 address pc = fst.current()->pc();
1257 nmethod* nm = (nmethod*) fst.current()->cb();
1258 ScopeDesc* sd = nm->scope_desc_at(pc);
1259 char buffer[8];
1260 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1261 size_t len = strlen(buffer);
1262 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1263 while (found != nullptr) {
1264 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1265 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1266 // Check that the bci found is bracketed by terminators.
1267 break;
1268 }
1269 found = strstr(found + 1, buffer);
1270 }
1271 if (!found) {
1272 continue;
1273 }
1274 }
1275
1276 if (DebugDeoptimization && !deopt) {
1277 deopt = true; // One-time only print before deopt
1278 tty->print_cr("[BEFORE Deoptimization]");
1279 trace_frames();
1280 trace_stack();
1281 }
1282 Deoptimization::deoptimize(this, *fst.current());
1283 }
1284 }
1285
1286 if (DebugDeoptimization && deopt) {
1287 tty->print_cr("[AFTER Deoptimization]");
1288 trace_frames();
1289 }
1290 }
1291
1292
1293 // Make zombies
1294 void JavaThread::make_zombies() {
1295 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1296 if (fst.current()->can_be_deoptimized()) {
1297 // it is a Java nmethod
1298 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1299 nm->make_not_entrant();
1300 }
1301 }
1302 }
1303 #endif // PRODUCT
1304
1305
1306 void JavaThread::deoptimize_marked_methods() {
1307 if (!has_last_Java_frame()) return;
1308 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1309 for (; !fst.is_done(); fst.next()) {
1310 if (fst.current()->should_be_deoptimized()) {
1311 Deoptimization::deoptimize(this, *fst.current());
1312 }
1313 }
1314 }
1315
1316 #ifdef ASSERT
1317 void JavaThread::verify_frame_info() {
1318 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1319 (has_last_Java_frame() && java_call_counter() > 0),
1320 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1321 has_last_Java_frame() ? "true" : "false", java_call_counter());
1322 }
1323 #endif
1324
1325 // Push on a new block of JNI handles.
1326 void JavaThread::push_jni_handle_block() {
1327 // Allocate a new block for JNI handles.
1328 // Inlined code from jni_PushLocalFrame()
1329 JNIHandleBlock* old_handles = active_handles();
1330 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1331 assert(old_handles != nullptr && new_handles != nullptr, "should not be null");
1332 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1333 set_active_handles(new_handles);
1334 }
1335
1336 // Pop off the current block of JNI handles.
1337 void JavaThread::pop_jni_handle_block() {
1338 // Release our JNI handle block
1339 JNIHandleBlock* old_handles = active_handles();
1340 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1341 assert(new_handles != nullptr, "should never set active handles to null");
1342 set_active_handles(new_handles);
1343 old_handles->set_pop_frame_link(nullptr);
1344 JNIHandleBlock::release_block(old_handles, this);
1345 }
1346
1347 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1348 // Verify that the deferred card marks have been flushed.
1349 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1350
1351 // Traverse the GCHandles
1352 Thread::oops_do_no_frames(f, cf);
1353
1354 if (active_handles() != nullptr) {
1355 active_handles()->oops_do(f);
1356 }
1357
1358 DEBUG_ONLY(verify_frame_info();)
1359
1360 if (has_last_Java_frame()) {
1361 // Traverse the monitor chunks
1362 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) {
1363 chunk->oops_do(f);
1364 }
1365 }
1366
1367 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!");
1368 // If we have deferred set_locals there might be oops waiting to be
1369 // written
1370 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1371 if (list != nullptr) {
1372 for (int i = 0; i < list->length(); i++) {
1373 list->at(i)->oops_do(f);
1374 }
1375 }
1376
1377 // Traverse instance variables at the end since the GC may be moving things
1378 // around using this function
1379 f->do_oop((oop*) &_vm_result);
1380 f->do_oop((oop*) &_exception_oop);
1381 #if INCLUDE_JVMCI
1382 f->do_oop((oop*) &_jvmci_reserved_oop0);
1383 #endif
1384
1385 if (jvmti_thread_state() != nullptr) {
1386 jvmti_thread_state()->oops_do(f, cf);
1387 }
1388
1389 // The continuation oops are really on the stack. But there is typically at most
1390 // one of those per thread, so we handle them here in the oops_do_no_frames part
1391 // so that we don't have to sprinkle as many stack watermark checks where these
1392 // oops are used. We just need to make sure the thread has started processing.
1393 ContinuationEntry* entry = _cont_entry;
1394 while (entry != nullptr) {
1395 f->do_oop((oop*)entry->cont_addr());
1396 f->do_oop((oop*)entry->chunk_addr());
1397 entry = entry->parent();
1398 }
1399
1400 if (LockingMode == LM_LIGHTWEIGHT) {
1401 lock_stack().oops_do(f);
1402 }
1403 }
1404
1405 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
1406 if (!has_last_Java_frame()) {
1407 return;
1408 }
1409 // Finish any pending lazy GC activity for the frames
1410 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc);
1411 // Traverse the execution stack
1412 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1413 fst.current()->oops_do(f, cf, fst.register_map());
1414 }
1415 }
1416
1417 #ifdef ASSERT
1418 void JavaThread::verify_states_for_handshake() {
1419 // This checks that the thread has a correct frame state during a handshake.
1420 verify_frame_info();
1421 }
1422 #endif
1423
1424 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1425 DEBUG_ONLY(verify_frame_info();)
1426 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1427
1428 if (has_last_Java_frame()) {
1429 // Traverse the execution stack
1430 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1431 fst.current()->nmethods_do(cf);
1432 }
1433 }
1434
1435 if (jvmti_thread_state() != nullptr) {
1436 jvmti_thread_state()->nmethods_do(cf);
1437 }
1438 }
1439
1440 void JavaThread::metadata_do(MetadataClosure* f) {
1441 if (has_last_Java_frame()) {
1442 // Traverse the execution stack to call f() on the methods in the stack
1443 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1444 fst.current()->metadata_do(f);
1445 }
1446 } else if (is_Compiler_thread()) {
1447 // need to walk ciMetadata in current compile tasks to keep alive.
1448 CompilerThread* ct = (CompilerThread*)this;
1449 if (ct->env() != nullptr) {
1450 ct->env()->metadata_do(f);
1451 }
1452 CompileTask* task = ct->task();
1453 if (task != nullptr) {
1454 task->metadata_do(f);
1455 }
1456 }
1457 }
1458
1459 // Printing
1460 static const char* _get_thread_state_name(JavaThreadState _thread_state) {
1461 switch (_thread_state) {
1462 case _thread_uninitialized: return "_thread_uninitialized";
1463 case _thread_new: return "_thread_new";
1464 case _thread_new_trans: return "_thread_new_trans";
1465 case _thread_in_native: return "_thread_in_native";
1466 case _thread_in_native_trans: return "_thread_in_native_trans";
1467 case _thread_in_vm: return "_thread_in_vm";
1468 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1469 case _thread_in_Java: return "_thread_in_Java";
1470 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1471 case _thread_blocked: return "_thread_blocked";
1472 case _thread_blocked_trans: return "_thread_blocked_trans";
1473 default: return "unknown thread state";
1474 }
1475 }
1476
1477 void JavaThread::print_thread_state_on(outputStream *st) const {
1478 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1479 }
1480
1481 // Called by Threads::print() for VM_PrintThreads operation
1482 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1483 st->print_raw("\"");
1484 st->print_raw(name());
1485 st->print_raw("\" ");
1486 oop thread_oop = threadObj();
1487 if (thread_oop != nullptr) {
1488 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1489 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1490 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1491 }
1492 Thread::print_on(st, print_extended_info);
1493 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1494 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1495 if (thread_oop != nullptr) {
1496 if (is_vthread_mounted()) {
1497 oop vt = vthread();
1498 assert(vt != nullptr, "");
1499 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1500 } else {
1501 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1502 }
1503 }
1504 #ifndef PRODUCT
1505 _safepoint_state->print_on(st);
1506 #endif // PRODUCT
1507 if (is_Compiler_thread()) {
1508 CompileTask *task = ((CompilerThread*)this)->task();
1509 if (task != nullptr) {
1510 st->print(" Compiling: ");
1511 task->print(st, nullptr, true, false);
1512 } else {
1513 st->print(" No compile task");
1514 }
1515 st->cr();
1516 }
1517 }
1518
1519 void JavaThread::print() const { print_on(tty); }
1520
1521 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1522 st->print("%s", get_thread_name_string(buf, buflen));
1523 }
1524
1525 // Called by fatal error handler. The difference between this and
1526 // JavaThread::print() is that we can't grab lock or allocate memory.
1527 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1528 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1529 Thread* current = Thread::current_or_null_safe();
1530 assert(current != nullptr, "cannot be called by a detached thread");
1531 st->fill_to(60);
1532 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1533 // Only access threadObj() if current thread is not a JavaThread
1534 // or if it is a JavaThread that can safely access oops.
1535 oop thread_obj = threadObj();
1536 if (thread_obj != nullptr) {
1537 st->print(java_lang_Thread::is_daemon(thread_obj) ? " daemon" : " ");
1538 }
1539 }
1540 st->print(" [");
1541 st->print("%s", _get_thread_state_name(_thread_state));
1542 if (osthread()) {
1543 st->print(", id=%d", osthread()->thread_id());
1544 }
1545 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ") (" PROPERFMT ")",
1546 p2i(stack_end()), p2i(stack_base()),
1547 PROPERFMTARGS(stack_size()));
1548 st->print("]");
1549
1550 ThreadsSMRSupport::print_info_on(this, st);
1551 return;
1552 }
1553
1554
1555 // Verification
1556
1557 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1558 // ignore if there is no stack
1559 if (!has_last_Java_frame()) return;
1560 // traverse the stack frames. Starts from top frame.
1561 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1562 frame* fr = fst.current();
1563 f(fr, fst.register_map());
1564 }
1565 }
1566
1567 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1568
1569 void JavaThread::verify() {
1570 // Verify oops in the thread.
1571 oops_do(&VerifyOopClosure::verify_oop, nullptr);
1572
1573 // Verify the stack frames.
1574 frames_do(frame_verify);
1575 }
1576
1577 // CR 6300358 (sub-CR 2137150)
1578 // Most callers of this method assume that it can't return null but a
1579 // thread may not have a name whilst it is in the process of attaching to
1580 // the VM - see CR 6412693, and there are places where a JavaThread can be
1581 // seen prior to having its threadObj set (e.g., JNI attaching threads and
1582 // if vm exit occurs during initialization). These cases can all be accounted
1583 // for such that this method never returns null.
1584 const char* JavaThread::name() const {
1585 if (Thread::is_JavaThread_protected(/* target */ this)) {
1586 // The target JavaThread is protected so get_thread_name_string() is safe:
1587 return get_thread_name_string();
1588 }
1589
1590 // The target JavaThread is not protected so we return the default:
1591 return Thread::name();
1592 }
1593
1594 // Like name() but doesn't include the protection check. This must only be
1595 // called when it is known to be safe, even though the protection check can't tell
1596 // that e.g. when this thread is the init_thread() - see instanceKlass.cpp.
1597 const char* JavaThread::name_raw() const {
1598 return get_thread_name_string();
1599 }
1600
1601 // Returns a non-null representation of this thread's name, or a suitable
1602 // descriptive string if there is no set name.
1603 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1604 const char* name_str;
1605 #ifdef ASSERT
1606 Thread* current = Thread::current_or_null_safe();
1607 assert(current != nullptr, "cannot be called by a detached thread");
1608 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1609 // Only access threadObj() if current thread is not a JavaThread
1610 // or if it is a JavaThread that can safely access oops.
1611 #endif
1612 oop thread_obj = threadObj();
1613 if (thread_obj != nullptr) {
1614 oop name = java_lang_Thread::name(thread_obj);
1615 if (name != nullptr) {
1616 if (buf == nullptr) {
1617 name_str = java_lang_String::as_utf8_string(name);
1618 } else {
1619 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1620 }
1621 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1622 name_str = "<no-name - thread is attaching>";
1623 } else {
1624 name_str = "<un-named>";
1625 }
1626 } else {
1627 name_str = Thread::name();
1628 }
1629 #ifdef ASSERT
1630 } else {
1631 // Current JavaThread has exited...
1632 if (current == this) {
1633 // ... and is asking about itself:
1634 name_str = "<no-name - current JavaThread has exited>";
1635 } else {
1636 // ... and it can't safely determine this JavaThread's name so
1637 // use the default thread name.
1638 name_str = Thread::name();
1639 }
1640 }
1641 #endif
1642 assert(name_str != nullptr, "unexpected null thread name");
1643 return name_str;
1644 }
1645
1646 // Helper to extract the name from the thread oop for logging.
1647 const char* JavaThread::name_for(oop thread_obj) {
1648 assert(thread_obj != nullptr, "precondition");
1649 oop name = java_lang_Thread::name(thread_obj);
1650 const char* name_str;
1651 if (name != nullptr) {
1652 name_str = java_lang_String::as_utf8_string(name);
1653 } else {
1654 name_str = "<un-named>";
1655 }
1656 return name_str;
1657 }
1658
1659 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1660
1661 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1662 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1663 // Link Java Thread object <-> C++ Thread
1664
1665 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1666 // and put it into a new Handle. The Handle "thread_oop" can then
1667 // be used to pass the C++ thread object to other methods.
1668
1669 // Set the Java level thread object (jthread) field of the
1670 // new thread (a JavaThread *) to C++ thread object using the
1671 // "thread_oop" handle.
1672
1673 // Set the thread field (a JavaThread *) of the
1674 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1675
1676 Handle thread_oop(Thread::current(),
1677 JNIHandles::resolve_non_null(jni_thread));
1678 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1679 "must be initialized");
1680 set_threadOopHandles(thread_oop());
1681
1682 if (prio == NoPriority) {
1683 prio = java_lang_Thread::priority(thread_oop());
1684 assert(prio != NoPriority, "A valid priority should be present");
1685 }
1686
1687 // Push the Java priority down to the native thread; needs Threads_lock
1688 Thread::set_priority(this, prio);
1689
1690 // Add the new thread to the Threads list and set it in motion.
1691 // We must have threads lock in order to call Threads::add.
1692 // It is crucial that we do not block before the thread is
1693 // added to the Threads list for if a GC happens, then the java_thread oop
1694 // will not be visited by GC.
1695 Threads::add(this);
1696 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
1697 // on a ThreadsList. We don't want to wait for the release when the
1698 // Theads_lock is dropped somewhere in the caller since the JavaThread*
1699 // is already visible to JVM/TI via the ThreadsList.
1700 java_lang_Thread::release_set_thread(thread_oop(), this);
1701 }
1702
1703 oop JavaThread::current_park_blocker() {
1704 // Support for JSR-166 locks
1705 oop thread_oop = threadObj();
1706 if (thread_oop != nullptr) {
1707 return java_lang_Thread::park_blocker(thread_oop);
1708 }
1709 return nullptr;
1710 }
1711
1712 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1713 // This is the external format, selecting the platform or vthread
1714 // as applicable, and allowing for a native-only stack.
1715 void JavaThread::print_jni_stack() {
1716 assert(this == JavaThread::current(), "Can't print stack of other threads");
1717 if (!has_last_Java_frame()) {
1718 ResourceMark rm(this);
1719 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN);
1720 if (buf == nullptr) {
1721 tty->print_cr("Unable to print native stack - out of memory");
1722 return;
1723 }
1724 address lastpc = nullptr;
1725 if (os::platform_print_native_stack(tty, nullptr, buf, O_BUFLEN, lastpc)) {
1726 // We have printed the native stack in platform-specific code,
1727 // so nothing else to do in this case.
1728 } else {
1729 frame f = os::current_frame();
1730 VMError::print_native_stack(tty, f, this, true /*print_source_info */,
1731 -1 /* max stack */, buf, O_BUFLEN);
1732 }
1733 } else {
1734 print_active_stack_on(tty);
1735 }
1736 }
1737
1738 void JavaThread::print_stack_on(outputStream* st) {
1739 if (!has_last_Java_frame()) return;
1740
1741 Thread* current_thread = Thread::current();
1742 ResourceMark rm(current_thread);
1743 HandleMark hm(current_thread);
1744
1745 RegisterMap reg_map(this,
1746 RegisterMap::UpdateMap::include,
1747 RegisterMap::ProcessFrames::include,
1748 RegisterMap::WalkContinuation::skip);
1749 vframe* start_vf = platform_thread_last_java_vframe(®_map);
1750 int count = 0;
1751 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1752 if (f->is_java_frame()) {
1753 javaVFrame* jvf = javaVFrame::cast(f);
1754 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1755
1756 // Print out lock information
1757 if (JavaMonitorsInStackTrace) {
1758 jvf->print_lock_info_on(st, count);
1759 }
1760 } else {
1761 // Ignore non-Java frames
1762 }
1763
1764 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1765 count++;
1766 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1767 }
1768 }
1769
1770 void JavaThread::print_vthread_stack_on(outputStream* st) {
1771 assert(is_vthread_mounted(), "Caller should have checked this");
1772 assert(has_last_Java_frame(), "must be");
1773
1774 Thread* current_thread = Thread::current();
1775 ResourceMark rm(current_thread);
1776 HandleMark hm(current_thread);
1777
1778 RegisterMap reg_map(this,
1779 RegisterMap::UpdateMap::include,
1780 RegisterMap::ProcessFrames::include,
1781 RegisterMap::WalkContinuation::include);
1782 ContinuationEntry* cont_entry = last_continuation();
1783 vframe* start_vf = last_java_vframe(®_map);
1784 int count = 0;
1785 for (vframe* f = start_vf; f != nullptr; f = f->sender()) {
1786 // Watch for end of vthread stack
1787 if (Continuation::is_continuation_enterSpecial(f->fr())) {
1788 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), "");
1789 if (cont_entry->is_virtual_thread()) {
1790 break;
1791 }
1792 cont_entry = cont_entry->parent();
1793 }
1794 if (f->is_java_frame()) {
1795 javaVFrame* jvf = javaVFrame::cast(f);
1796 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1797
1798 // Print out lock information
1799 if (JavaMonitorsInStackTrace) {
1800 jvf->print_lock_info_on(st, count);
1801 }
1802 } else {
1803 // Ignore non-Java frames
1804 }
1805
1806 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1807 count++;
1808 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1809 }
1810 }
1811
1812 void JavaThread::print_active_stack_on(outputStream* st) {
1813 if (is_vthread_mounted()) {
1814 print_vthread_stack_on(st);
1815 } else {
1816 print_stack_on(st);
1817 }
1818 }
1819
1820 #if INCLUDE_JVMTI
1821 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1822 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1823 set_jvmti_vthread(thread_oop);
1824
1825 // unbind current JvmtiThreadState from JavaThread
1826 JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1827
1828 // bind new JvmtiThreadState to JavaThread
1829 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1830
1831 return jvmti_thread_state();
1832 }
1833 #endif
1834
1835 // JVMTI PopFrame support
1836 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1837 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments");
1838 if (in_bytes(size_in_bytes) != 0) {
1839 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1840 _popframe_preserved_args_size = in_bytes(size_in_bytes);
1841 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1842 }
1843 }
1844
1845 void* JavaThread::popframe_preserved_args() {
1846 return _popframe_preserved_args;
1847 }
1848
1849 ByteSize JavaThread::popframe_preserved_args_size() {
1850 return in_ByteSize(_popframe_preserved_args_size);
1851 }
1852
1853 WordSize JavaThread::popframe_preserved_args_size_in_words() {
1854 int sz = in_bytes(popframe_preserved_args_size());
1855 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1856 return in_WordSize(sz / wordSize);
1857 }
1858
1859 void JavaThread::popframe_free_preserved_args() {
1860 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice");
1861 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1862 _popframe_preserved_args = nullptr;
1863 _popframe_preserved_args_size = 0;
1864 }
1865
1866 #ifndef PRODUCT
1867
1868 void JavaThread::trace_frames() {
1869 tty->print_cr("[Describe stack]");
1870 int frame_no = 1;
1871 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1872 tty->print(" %d. ", frame_no++);
1873 fst.current()->print_value_on(tty, this);
1874 tty->cr();
1875 }
1876 }
1877
1878 class PrintAndVerifyOopClosure: public OopClosure {
1879 protected:
1880 template <class T> inline void do_oop_work(T* p) {
1881 oop obj = RawAccess<>::oop_load(p);
1882 if (obj == nullptr) return;
1883 tty->print(INTPTR_FORMAT ": ", p2i(p));
1884 if (oopDesc::is_oop_or_null(obj)) {
1885 if (obj->is_objArray()) {
1886 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1887 } else {
1888 obj->print();
1889 }
1890 } else {
1891 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1892 }
1893 tty->cr();
1894 }
1895 public:
1896 virtual void do_oop(oop* p) { do_oop_work(p); }
1897 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1898 };
1899
1900 #ifdef ASSERT
1901 // Print or validate the layout of stack frames
1902 void JavaThread::print_frame_layout(int depth, bool validate_only) {
1903 ResourceMark rm;
1904 PreserveExceptionMark pm(this);
1905 FrameValues values;
1906 int frame_no = 0;
1907 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1908 fst.current()->describe(values, ++frame_no, fst.register_map());
1909 if (depth == frame_no) break;
1910 }
1911 Continuation::describe(values);
1912 if (validate_only) {
1913 values.validate();
1914 } else {
1915 tty->print_cr("[Describe stack layout]");
1916 values.print(this);
1917 }
1918 }
1919 #endif
1920
1921 void JavaThread::trace_stack_from(vframe* start_vf) {
1922 ResourceMark rm;
1923 int vframe_no = 1;
1924 for (vframe* f = start_vf; f; f = f->sender()) {
1925 if (f->is_java_frame()) {
1926 javaVFrame::cast(f)->print_activation(vframe_no++);
1927 } else {
1928 f->print();
1929 }
1930 if (vframe_no > StackPrintLimit) {
1931 tty->print_cr("...<more frames>...");
1932 return;
1933 }
1934 }
1935 }
1936
1937
1938 void JavaThread::trace_stack() {
1939 if (!has_last_Java_frame()) return;
1940 Thread* current_thread = Thread::current();
1941 ResourceMark rm(current_thread);
1942 HandleMark hm(current_thread);
1943 RegisterMap reg_map(this,
1944 RegisterMap::UpdateMap::include,
1945 RegisterMap::ProcessFrames::include,
1946 RegisterMap::WalkContinuation::skip);
1947 trace_stack_from(last_java_vframe(®_map));
1948 }
1949
1950
1951 #endif // PRODUCT
1952
1953 void JavaThread::inc_held_monitor_count(intx i, bool jni) {
1954 #ifdef SUPPORT_MONITOR_COUNT
1955 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _held_monitor_count);
1956 _held_monitor_count += i;
1957 if (jni) {
1958 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _jni_monitor_count);
1959 _jni_monitor_count += i;
1960 }
1961 #endif
1962 }
1963
1964 void JavaThread::dec_held_monitor_count(intx i, bool jni) {
1965 #ifdef SUPPORT_MONITOR_COUNT
1966 _held_monitor_count -= i;
1967 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _held_monitor_count);
1968 if (jni) {
1969 _jni_monitor_count -= i;
1970 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INTX_FORMAT, _jni_monitor_count);
1971 }
1972 #endif
1973 }
1974
1975 frame JavaThread::vthread_last_frame() {
1976 assert (is_vthread_mounted(), "Virtual thread not mounted");
1977 return last_frame();
1978 }
1979
1980 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
1981 const ContinuationEntry* entry = vthread_continuation();
1982 guarantee (entry != nullptr, "Not a carrier thread");
1983 frame f = entry->to_frame();
1984 if (reg_map->process_frames()) {
1985 entry->flush_stack_processing(this);
1986 }
1987 entry->update_register_map(reg_map);
1988 return f.sender(reg_map);
1989 }
1990
1991 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
1992 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
1993 }
1994
1995 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
1996 assert(reg_map != nullptr, "a map must be given");
1997 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
1998 if (vf->is_java_frame()) return javaVFrame::cast(vf);
1999 }
2000 return nullptr;
2001 }
2002
2003 Klass* JavaThread::security_get_caller_class(int depth) {
2004 ResetNoHandleMark rnhm;
2005 HandleMark hm(Thread::current());
2006
2007 vframeStream vfst(this);
2008 vfst.security_get_caller_frame(depth);
2009 if (!vfst.at_end()) {
2010 return vfst.method()->method_holder();
2011 }
2012 return nullptr;
2013 }
2014
2015 // Internal convenience function for millisecond resolution sleeps.
2016 bool JavaThread::sleep(jlong millis) {
2017 jlong nanos;
2018 if (millis > max_jlong / NANOUNITS_PER_MILLIUNIT) {
2019 // Conversion to nanos would overflow, saturate at max
2020 nanos = max_jlong;
2021 } else {
2022 nanos = millis * NANOUNITS_PER_MILLIUNIT;
2023 }
2024 return sleep_nanos(nanos);
2025 }
2026
2027 // java.lang.Thread.sleep support
2028 // Returns true if sleep time elapsed as expected, and false
2029 // if the thread was interrupted.
2030 bool JavaThread::sleep_nanos(jlong nanos) {
2031 assert(this == Thread::current(), "thread consistency check");
2032 assert(nanos >= 0, "nanos are in range");
2033
2034 ParkEvent * const slp = this->_SleepEvent;
2035 // Because there can be races with thread interruption sending an unpark()
2036 // to the event, we explicitly reset it here to avoid an immediate return.
2037 // The actual interrupt state will be checked before we park().
2038 slp->reset();
2039 // Thread interruption establishes a happens-before ordering in the
2040 // Java Memory Model, so we need to ensure we synchronize with the
2041 // interrupt state.
2042 OrderAccess::fence();
2043
2044 jlong prevtime = os::javaTimeNanos();
2045
2046 jlong nanos_remaining = nanos;
2047
2048 for (;;) {
2049 // interruption has precedence over timing out
2050 if (this->is_interrupted(true)) {
2051 return false;
2052 }
2053
2054 if (nanos_remaining <= 0) {
2055 return true;
2056 }
2057
2058 {
2059 ThreadBlockInVM tbivm(this);
2060 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
2061 slp->park_nanos(nanos_remaining);
2062 }
2063
2064 // Update elapsed time tracking
2065 jlong newtime = os::javaTimeNanos();
2066 if (newtime - prevtime < 0) {
2067 // time moving backwards, should only happen if no monotonic clock
2068 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2069 assert(false,
2070 "unexpected time moving backwards detected in JavaThread::sleep()");
2071 } else {
2072 nanos_remaining -= (newtime - prevtime);
2073 }
2074 prevtime = newtime;
2075 }
2076 }
2077
2078 // Last thread running calls java.lang.Shutdown.shutdown()
2079 void JavaThread::invoke_shutdown_hooks() {
2080 HandleMark hm(this);
2081
2082 // We could get here with a pending exception, if so clear it now.
2083 if (this->has_pending_exception()) {
2084 this->clear_pending_exception();
2085 }
2086
2087 EXCEPTION_MARK;
2088 Klass* shutdown_klass =
2089 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
2090 THREAD);
2091 if (shutdown_klass != nullptr) {
2092 // SystemDictionary::resolve_or_null will return null if there was
2093 // an exception. If we cannot load the Shutdown class, just don't
2094 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
2095 // won't be run. Note that if a shutdown hook was registered,
2096 // the Shutdown class would have already been loaded
2097 // (Runtime.addShutdownHook will load it).
2098 JavaValue result(T_VOID);
2099 JavaCalls::call_static(&result,
2100 shutdown_klass,
2101 vmSymbols::shutdown_name(),
2102 vmSymbols::void_method_signature(),
2103 THREAD);
2104 }
2105 CLEAR_PENDING_EXCEPTION;
2106 }
2107
2108 #ifndef PRODUCT
2109 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
2110 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
2111 }
2112 #endif
2113
2114 // Helper function to create the java.lang.Thread object for a
2115 // VM-internal thread. The thread will have the given name, and be
2116 // a member of the "system" ThreadGroup.
2117 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) {
2118 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2119
2120 // Initialize thread_oop to put it into the system threadGroup.
2121 // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2122 Handle thread_group(THREAD, Universe::system_thread_group());
2123 Handle thread_oop =
2124 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2125 vmSymbols::threadgroup_string_void_signature(),
2126 thread_group,
2127 string,
2128 CHECK_NH);
2129
2130 return thread_oop;
2131 }
2132
2133 // Starts the target JavaThread as a daemon of the given priority, and
2134 // bound to the given java.lang.Thread instance.
2135 // The Threads_lock is held for the duration.
2136 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2137 Handle thread_oop, ThreadPriority prio) {
2138
2139 assert(target->osthread() != nullptr, "target thread is not properly initialized");
2140
2141 MutexLocker mu(current, Threads_lock);
2142
2143 // Initialize the fields of the thread_oop first.
2144 if (prio != NoPriority) {
2145 java_lang_Thread::set_priority(thread_oop(), prio);
2146 // Note: we don't call os::set_priority here. Possibly we should,
2147 // else all threads should call it themselves when they first run.
2148 }
2149
2150 java_lang_Thread::set_daemon(thread_oop());
2151
2152 // Now bind the thread_oop to the target JavaThread.
2153 target->set_threadOopHandles(thread_oop());
2154
2155 Threads::add(target); // target is now visible for safepoint/handshake
2156 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is
2157 // on a ThreadsList. We don't want to wait for the release when the
2158 // Theads_lock is dropped when the 'mu' destructor is run since the
2159 // JavaThread* is already visible to JVM/TI via the ThreadsList.
2160
2161 assert(java_lang_Thread::thread(thread_oop()) == nullptr, "must not be alive");
2162 java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now
2163 Thread::start(target);
2164 }
2165
2166 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2167 // At this point it may be possible that no osthread was created for the
2168 // JavaThread due to lack of resources. However, since this must work
2169 // for critical system threads just check and abort if this fails.
2170 if (thread->osthread() == nullptr) {
2171 // This isn't really an OOM condition, but historically this is what
2172 // we report.
2173 vm_exit_during_initialization("java.lang.OutOfMemoryError",
2174 os::native_thread_creation_failed_msg());
2175 }
2176 }
2177
2178 void JavaThread::pretouch_stack() {
2179 // Given an established java thread stack with usable area followed by
2180 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging
2181 // from the current frame down to the start of the shadow zone.
2182 const address end = _stack_overflow_state.shadow_zone_safe_limit();
2183 if (is_in_full_stack(end)) {
2184 char* p1 = (char*) alloca(1);
2185 address here = (address) &p1;
2186 if (is_in_full_stack(here) && here > end) {
2187 size_t to_alloc = here - end;
2188 char* p2 = (char*) alloca(to_alloc);
2189 log_trace(os, thread)("Pretouching thread stack from " PTR_FORMAT " to " PTR_FORMAT ".",
2190 p2i(p2), p2i(end));
2191 os::pretouch_memory(p2, p2 + to_alloc,
2192 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096));
2193 }
2194 }
2195 }
2196
2197 // Deferred OopHandle release support.
2198
2199 class OopHandleList : public CHeapObj<mtInternal> {
2200 static const int _count = 4;
2201 OopHandle _handles[_count];
2202 OopHandleList* _next;
2203 int _index;
2204 public:
2205 OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2206 void add(OopHandle h) {
2207 assert(_index < _count, "too many additions");
2208 _handles[_index++] = h;
2209 }
2210 ~OopHandleList() {
2211 assert(_index == _count, "usage error");
2212 for (int i = 0; i < _index; i++) {
2213 _handles[i].release(JavaThread::thread_oop_storage());
2214 }
2215 }
2216 OopHandleList* next() const { return _next; }
2217 };
2218
2219 OopHandleList* JavaThread::_oop_handle_list = nullptr;
2220
2221 // Called by the ServiceThread to do the work of releasing
2222 // the OopHandles.
2223 void JavaThread::release_oop_handles() {
2224 OopHandleList* list;
2225 {
2226 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2227 list = _oop_handle_list;
2228 _oop_handle_list = nullptr;
2229 }
2230 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2231
2232 while (list != nullptr) {
2233 OopHandleList* l = list;
2234 list = l->next();
2235 delete l;
2236 }
2237 }
2238
2239 // Add our OopHandles for later release.
2240 void JavaThread::add_oop_handles_for_release() {
2241 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2242 OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2243 new_head->add(_threadObj);
2244 new_head->add(_vthread);
2245 new_head->add(_jvmti_vthread);
2246 new_head->add(_scopedValueCache);
2247 _oop_handle_list = new_head;
2248 Service_lock->notify_all();
2249 }