1 /*
2 * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "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/mutexLocker.hpp"
74 #include "runtime/orderAccess.hpp"
75 #include "runtime/osThread.hpp"
76 #include "runtime/safepoint.hpp"
77 #include "runtime/safepointMechanism.inline.hpp"
78 #include "runtime/safepointVerifiers.hpp"
79 #include "runtime/serviceThread.hpp"
80 #include "runtime/stackFrameStream.inline.hpp"
81 #include "runtime/stackWatermarkSet.hpp"
82 #include "runtime/synchronizer.hpp"
83 #include "runtime/threadCritical.hpp"
84 #include "runtime/threadSMR.inline.hpp"
85 #include "runtime/threadStatisticalInfo.hpp"
86 #include "runtime/threadWXSetters.inline.hpp"
87 #include "runtime/timer.hpp"
88 #include "runtime/timerTrace.hpp"
89 #include "runtime/vframe.inline.hpp"
90 #include "runtime/vframeArray.hpp"
91 #include "runtime/vframe_hp.hpp"
92 #include "runtime/vmThread.hpp"
93 #include "runtime/vmOperations.hpp"
94 #include "services/threadService.hpp"
95 #include "utilities/copy.hpp"
96 #include "utilities/defaultStream.hpp"
97 #include "utilities/dtrace.hpp"
98 #include "utilities/events.hpp"
99 #include "utilities/macros.hpp"
100 #include "utilities/preserveException.hpp"
101 #include "utilities/spinYield.hpp"
102 #if INCLUDE_JVMCI
103 #include "jvmci/jvmci.hpp"
104 #include "jvmci/jvmciEnv.hpp"
105 #endif
106 #if INCLUDE_JFR
107 #include "jfr/jfr.hpp"
108 #endif
109
110 // Set by os layer.
111 size_t JavaThread::_stack_size_at_create = 0;
112
113 #ifdef DTRACE_ENABLED
114
115 // Only bother with this argument setup if dtrace is available
116
117 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
118 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
119
120 #define DTRACE_THREAD_PROBE(probe, javathread) \
121 { \
122 ResourceMark rm(this); \
123 int len = 0; \
124 const char* name = (javathread)->name(); \
125 len = strlen(name); \
126 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
127 (char *) name, len, \
128 java_lang_Thread::thread_id((javathread)->threadObj()), \
129 (uintptr_t) (javathread)->osthread()->thread_id(), \
130 java_lang_Thread::is_daemon((javathread)->threadObj())); \
131 }
132
133 #else // ndef DTRACE_ENABLED
134
135 #define DTRACE_THREAD_PROBE(probe, javathread)
136
137 #endif // ndef DTRACE_ENABLED
138
139 void JavaThread::smr_delete() {
140 if (_on_thread_list) {
141 ThreadsSMRSupport::smr_delete(this);
142 } else {
143 delete this;
144 }
145 }
146
147 // Initialized by VMThread at vm_global_init
148 OopStorage* JavaThread::_thread_oop_storage = NULL;
149
150 OopStorage* JavaThread::thread_oop_storage() {
151 assert(_thread_oop_storage != NULL, "not yet initialized");
152 return _thread_oop_storage;
153 }
154
155 void JavaThread::set_threadOopHandles(oop p) {
156 assert(_thread_oop_storage != NULL, "not yet initialized");
157 _threadObj = OopHandle(_thread_oop_storage, p);
158 _vthread = OopHandle(_thread_oop_storage, p);
159 _jvmti_vthread = OopHandle(_thread_oop_storage, NULL);
160 _scopedValueCache = OopHandle(_thread_oop_storage, NULL);
161 }
162
163 oop JavaThread::threadObj() const {
164 // Ideally we would verify the current thread is oop_safe when this is called, but as we can
165 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That
166 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS.
167 // Instead callers must verify oop safe access.
168 return _threadObj.resolve();
169 }
170
171 oop JavaThread::vthread() const {
172 return _vthread.resolve();
173 }
174
175 void JavaThread::set_vthread(oop p) {
176 assert(_thread_oop_storage != NULL, "not yet initialized");
177 _vthread.replace(p);
178 }
179
180 oop JavaThread::jvmti_vthread() const {
181 return _jvmti_vthread.resolve();
182 }
183
184 void JavaThread::set_jvmti_vthread(oop p) {
185 assert(_thread_oop_storage != NULL, "not yet initialized");
186 _jvmti_vthread.replace(p);
187 }
188
189 oop JavaThread::scopedValueCache() const {
190 return _scopedValueCache.resolve();
191 }
192
193 void JavaThread::set_scopedValueCache(oop p) {
194 if (_scopedValueCache.ptr_raw() != NULL) { // i.e. if the OopHandle has been allocated
195 _scopedValueCache.replace(p);
196 } else {
197 assert(p == NULL, "not yet initialized");
198 }
199 }
200
201 void JavaThread::clear_scopedValueBindings() {
202 set_scopedValueCache(NULL);
203 oop vthread_oop = vthread();
204 // vthread may be null here if we get a VM error during startup,
205 // before the java.lang.Thread instance has been created.
206 if (vthread_oop != NULL) {
207 java_lang_Thread::clear_scopedValueBindings(vthread_oop);
208 }
209 }
210
211 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
212 bool daemon, TRAPS) {
213 assert(thread_group.not_null(), "thread group should be specified");
214 assert(threadObj() == NULL, "should only create Java thread object once");
215
216 InstanceKlass* ik = vmClasses::Thread_klass();
217 assert(ik->is_initialized(), "must be");
218 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
219
220 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
221 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
222 // constructor calls Thread.current(), which must be set here.
223 java_lang_Thread::set_thread(thread_oop(), this);
224 set_threadOopHandles(thread_oop());
225
226 JavaValue result(T_VOID);
227 if (thread_name != NULL) {
228 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
229 // Thread gets assigned specified name and null target
230 JavaCalls::call_special(&result,
231 thread_oop,
232 ik,
233 vmSymbols::object_initializer_name(),
234 vmSymbols::threadgroup_string_void_signature(),
235 thread_group,
236 name,
237 THREAD);
238 } else {
239 // Thread gets assigned name "Thread-nnn" and null target
240 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
241 JavaCalls::call_special(&result,
242 thread_oop,
243 ik,
244 vmSymbols::object_initializer_name(),
245 vmSymbols::threadgroup_runnable_void_signature(),
246 thread_group,
247 Handle(),
248 THREAD);
249 }
250 os::set_priority(this, NormPriority);
251
252 if (daemon) {
253 java_lang_Thread::set_daemon(thread_oop());
254 }
255 }
256
257 // ======= JavaThread ========
258
259 #if INCLUDE_JVMCI
260
261 jlong* JavaThread::_jvmci_old_thread_counters;
262
263 bool jvmci_counters_include(JavaThread* thread) {
264 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
265 }
266
267 void JavaThread::collect_counters(jlong* array, int length) {
268 assert(length == JVMCICounterSize, "wrong value");
269 for (int i = 0; i < length; i++) {
270 array[i] = _jvmci_old_thread_counters[i];
271 }
272 for (JavaThread* tp : ThreadsListHandle()) {
273 if (jvmci_counters_include(tp)) {
274 for (int i = 0; i < length; i++) {
275 array[i] += tp->_jvmci_counters[i];
276 }
277 }
278 }
279 }
280
281 // Attempt to enlarge the array for per thread counters.
282 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) {
283 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI);
284 if (new_counters == NULL) {
285 return NULL;
286 }
287 if (old_counters == NULL) {
288 old_counters = new_counters;
289 memset(old_counters, 0, sizeof(jlong) * new_size);
290 } else {
291 for (int i = 0; i < MIN2((int) current_size, new_size); i++) {
292 new_counters[i] = old_counters[i];
293 }
294 if (new_size > current_size) {
295 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size));
296 }
297 FREE_C_HEAP_ARRAY(jlong, old_counters);
298 }
299 return new_counters;
300 }
301
302 // Attempt to enlarge the array for per thread counters.
303 bool JavaThread::resize_counters(int current_size, int new_size) {
304 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size);
305 if (new_counters == NULL) {
306 return false;
307 } else {
308 _jvmci_counters = new_counters;
309 return true;
310 }
311 }
312
313 class VM_JVMCIResizeCounters : public VM_Operation {
314 private:
315 int _new_size;
316 bool _failed;
317
318 public:
319 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { }
320 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; }
321 bool allow_nested_vm_operations() const { return true; }
322 void doit() {
323 // Resize the old thread counters array
324 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size);
325 if (new_counters == NULL) {
326 _failed = true;
327 return;
328 } else {
329 JavaThread::_jvmci_old_thread_counters = new_counters;
330 }
331
332 // Now resize each threads array
333 for (JavaThread* tp : ThreadsListHandle()) {
334 if (!tp->resize_counters(JVMCICounterSize, _new_size)) {
335 _failed = true;
336 break;
337 }
338 }
339 if (!_failed) {
340 JVMCICounterSize = _new_size;
341 }
342 }
343
344 bool failed() { return _failed; }
345 };
346
347 bool JavaThread::resize_all_jvmci_counters(int new_size) {
348 VM_JVMCIResizeCounters op(new_size);
349 VMThread::execute(&op);
350 return !op.failed();
351 }
352
353 #endif // INCLUDE_JVMCI
354
355 #ifdef ASSERT
356 // Checks safepoint allowed and clears unhandled oops at potential safepoints.
357 void JavaThread::check_possible_safepoint() {
358 if (_no_safepoint_count > 0) {
359 print_owned_locks();
360 assert(false, "Possible safepoint reached by thread that does not allow it");
361 }
362 #ifdef CHECK_UNHANDLED_OOPS
363 // Clear unhandled oops in JavaThreads so we get a crash right away.
364 clear_unhandled_oops();
365 #endif // CHECK_UNHANDLED_OOPS
366
367 // Macos/aarch64 should be in the right state for safepoint (e.g.
368 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely
369 // happens in practice, making such issues hard to find and reproduce.
370 #if defined(__APPLE__) && defined(AARCH64)
371 if (AssertWXAtThreadSync) {
372 assert_wx_state(WXWrite);
373 }
374 #endif
375 }
376
377 void JavaThread::check_for_valid_safepoint_state() {
378 // Check NoSafepointVerifier, which is implied by locks taken that can be
379 // shared with the VM thread. This makes sure that no locks with allow_vm_block
380 // are held.
381 check_possible_safepoint();
382
383 if (thread_state() != _thread_in_vm) {
384 fatal("LEAF method calling lock?");
385 }
386
387 if (GCALotAtAllSafepoints) {
388 // We could enter a safepoint here and thus have a gc
389 InterfaceSupport::check_gc_alot();
390 }
391 }
392 #endif // ASSERT
393
394 // A JavaThread is a normal Java thread
395
396 JavaThread::JavaThread() :
397 // Initialize fields
398
399 _on_thread_list(false),
400 DEBUG_ONLY(_java_call_counter(0) COMMA)
401 _entry_point(nullptr),
402 _deopt_mark(nullptr),
403 _deopt_nmethod(nullptr),
404 _vframe_array_head(nullptr),
405 _vframe_array_last(nullptr),
406 _jvmti_deferred_updates(nullptr),
407 _callee_target(nullptr),
408 _vm_result(nullptr),
409 _vm_result_2(nullptr),
410
411 _current_pending_monitor(NULL),
412 _current_pending_monitor_is_from_java(true),
413 _current_waiting_monitor(NULL),
414 _active_handles(NULL),
415 _free_handle_block(NULL),
416 _Stalled(0),
417
418 _monitor_chunks(nullptr),
419
420 _suspend_flags(0),
421
422 _thread_state(_thread_new),
423 _saved_exception_pc(nullptr),
424 #ifdef ASSERT
425 _no_safepoint_count(0),
426 _visited_for_critical_count(false),
427 #endif
428
429 _terminated(_not_terminated),
430 _in_deopt_handler(0),
431 _doing_unsafe_access(false),
432 _do_not_unlock_if_synchronized(false),
433 #if INCLUDE_JVMTI
434 _carrier_thread_suspended(false),
435 _is_in_VTMS_transition(false),
436 _is_in_tmp_VTMS_transition(false),
437 #ifdef ASSERT
438 _is_VTMS_transition_disabler(false),
439 #endif
440 #endif
441 _jni_attach_state(_not_attaching_via_jni),
442 #if INCLUDE_JVMCI
443 _pending_deoptimization(-1),
444 _pending_monitorenter(false),
445 _pending_transfer_to_interpreter(false),
446 _in_retryable_allocation(false),
447 _pending_failed_speculation(0),
448 _jvmci{nullptr},
449 _libjvmci_runtime(nullptr),
450 _jvmci_counters(nullptr),
451 _jvmci_reserved0(0),
452 _jvmci_reserved1(0),
453 _jvmci_reserved_oop0(nullptr),
454 #endif // INCLUDE_JVMCI
455
456 _exception_oop(oop()),
457 _exception_pc(0),
458 _exception_handler_pc(0),
459 _is_method_handle_return(0),
460
461 _jni_active_critical(0),
462 _pending_jni_exception_check_fn(nullptr),
463 _depth_first_number(0),
464
465 // JVMTI PopFrame support
466 _popframe_condition(popframe_inactive),
467 _frames_to_pop_failed_realloc(0),
468
469 _cont_entry(nullptr),
470 _cont_fastpath(0),
471 _cont_fastpath_thread_state(1),
472 _held_monitor_count(0),
473 _jni_monitor_count(0),
474
475 _handshake(this),
476
477 _popframe_preserved_args(nullptr),
478 _popframe_preserved_args_size(0),
479
480 _jvmti_thread_state(nullptr),
481 _interp_only_mode(0),
482 _should_post_on_exceptions_flag(JNI_FALSE),
483 _thread_stat(new ThreadStatistics()),
484
485 _parker(),
486
487 _class_to_be_initialized(nullptr),
488
489 _SleepEvent(ParkEvent::Allocate(this))
490 {
491 set_jni_functions(jni_functions());
492
493 #if INCLUDE_JVMCI
494 assert(_jvmci._implicit_exception_pc == nullptr, "must be");
495 if (JVMCICounterSize > 0) {
496 resize_counters(0, (int) JVMCICounterSize);
497 }
498 #endif // INCLUDE_JVMCI
499
500 // Setup safepoint state info for this thread
501 ThreadSafepointState::create(this);
502
503 SafepointMechanism::initialize_header(this);
504
505 set_requires_cross_modify_fence(false);
506
507 pd_initialize();
508 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
509 }
510
511 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() {
512 if (is_attaching_via_jni) {
513 _jni_attach_state = _attaching_via_jni;
514 }
515 }
516
517
518 // interrupt support
519
520 void JavaThread::interrupt() {
521 // All callers should have 'this' thread protected by a
522 // ThreadsListHandle so that it cannot terminate and deallocate
523 // itself.
524 debug_only(check_for_dangling_thread_pointer(this);)
525
526 // For Windows _interrupt_event
527 WINDOWS_ONLY(osthread()->set_interrupted(true);)
528
529 // For Thread.sleep
530 _SleepEvent->unpark();
531
532 // For JSR166 LockSupport.park
533 parker()->unpark();
534
535 // For ObjectMonitor and JvmtiRawMonitor
536 _ParkEvent->unpark();
537 }
538
539
540 bool JavaThread::is_interrupted(bool clear_interrupted) {
541 debug_only(check_for_dangling_thread_pointer(this);)
542
543 if (_threadObj.peek() == NULL) {
544 // If there is no j.l.Thread then it is impossible to have
545 // been interrupted. We can find NULL during VM initialization
546 // or when a JNI thread is still in the process of attaching.
547 // In such cases this must be the current thread.
548 assert(this == Thread::current(), "invariant");
549 return false;
550 }
551
552 bool interrupted = java_lang_Thread::interrupted(threadObj());
553
554 // NOTE that since there is no "lock" around the interrupt and
555 // is_interrupted operations, there is the possibility that the
556 // interrupted flag will be "false" but that the
557 // low-level events will be in the signaled state. This is
558 // intentional. The effect of this is that Object.wait() and
559 // LockSupport.park() will appear to have a spurious wakeup, which
560 // is allowed and not harmful, and the possibility is so rare that
561 // it is not worth the added complexity to add yet another lock.
562 // For the sleep event an explicit reset is performed on entry
563 // to JavaThread::sleep, so there is no early return. It has also been
564 // recommended not to put the interrupted flag into the "event"
565 // structure because it hides the issue.
566 // Also, because there is no lock, we must only clear the interrupt
567 // state if we are going to report that we were interrupted; otherwise
568 // an interrupt that happens just after we read the field would be lost.
569 if (interrupted && clear_interrupted) {
570 assert(this == Thread::current(), "only the current thread can clear");
571 java_lang_Thread::set_interrupted(threadObj(), false);
572 WINDOWS_ONLY(osthread()->set_interrupted(false);)
573 }
574
575 return interrupted;
576 }
577
578 void JavaThread::block_if_vm_exited() {
579 if (_terminated == _vm_exited) {
580 // _vm_exited is set at safepoint, and Threads_lock is never released
581 // so we will block here forever.
582 // Here we can be doing a jump from a safe state to an unsafe state without
583 // proper transition, but it happens after the final safepoint has begun so
584 // this jump won't cause any safepoint problems.
585 set_thread_state(_thread_in_vm);
586 Threads_lock->lock();
587 ShouldNotReachHere();
588 }
589 }
590
591 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() {
592 _jni_attach_state = _not_attaching_via_jni;
593 set_entry_point(entry_point);
594 // Create the native thread itself.
595 // %note runtime_23
596 os::ThreadType thr_type = os::java_thread;
597 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread :
598 os::java_thread;
599 os::create_thread(this, thr_type, stack_sz);
600 // The _osthread may be NULL here because we ran out of memory (too many threads active).
601 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
602 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
603 // the exception consists of creating the exception object & initializing it, initialization
604 // will leave the VM via a JavaCall and then all locks must be unlocked).
605 //
606 // The thread is still suspended when we reach here. Thread must be explicit started
607 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
608 // by calling Threads:add. The reason why this is not done here, is because the thread
609 // object must be fully initialized (take a look at JVM_Start)
610 }
611
612 JavaThread::~JavaThread() {
613
614 // Enqueue OopHandles for release by the service thread.
615 add_oop_handles_for_release();
616
617 // Return the sleep event to the free list
618 ParkEvent::Release(_SleepEvent);
619 _SleepEvent = NULL;
620
621 // Free any remaining previous UnrollBlock
622 vframeArray* old_array = vframe_array_last();
623
624 if (old_array != NULL) {
625 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
626 old_array->set_unroll_block(NULL);
627 delete old_info;
628 delete old_array;
629 }
630
631 JvmtiDeferredUpdates* updates = deferred_updates();
632 if (updates != NULL) {
633 // This can only happen if thread is destroyed before deoptimization occurs.
634 assert(updates->count() > 0, "Updates holder not deleted");
635 // free deferred updates.
636 delete updates;
637 set_deferred_updates(NULL);
638 }
639
640 // All Java related clean up happens in exit
641 ThreadSafepointState::destroy(this);
642 if (_thread_stat != NULL) delete _thread_stat;
643
644 #if INCLUDE_JVMCI
645 if (JVMCICounterSize > 0) {
646 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
647 }
648 #endif // INCLUDE_JVMCI
649 }
650
651
652 // First JavaThread specific code executed by a new Java thread.
653 void JavaThread::pre_run() {
654 // empty - see comments in run()
655 }
656
657 // The main routine called by a new Java thread. This isn't overridden
658 // by subclasses, instead different subclasses define a different "entry_point"
659 // which defines the actual logic for that kind of thread.
660 void JavaThread::run() {
661 // initialize thread-local alloc buffer related fields
662 initialize_tlab();
663
664 _stack_overflow_state.create_stack_guard_pages();
665
666 cache_global_variables();
667
668 // Thread is now sufficiently initialized to be handled by the safepoint code as being
669 // in the VM. Change thread state from _thread_new to _thread_in_vm
670 assert(this->thread_state() == _thread_new, "wrong thread state");
671 set_thread_state(_thread_in_vm);
672
673 // Before a thread is on the threads list it is always safe, so after leaving the
674 // _thread_new we should emit a instruction barrier. The distance to modified code
675 // from here is probably far enough, but this is consistent and safe.
676 OrderAccess::cross_modify_fence();
677
678 assert(JavaThread::current() == this, "sanity check");
679 assert(!Thread::current()->owns_locks(), "sanity check");
680
681 DTRACE_THREAD_PROBE(start, this);
682
683 // This operation might block. We call that after all safepoint checks for a new thread has
684 // been completed.
685 set_active_handles(JNIHandleBlock::allocate_block());
686
687 if (JvmtiExport::should_post_thread_life()) {
688 JvmtiExport::post_thread_start(this);
689
690 }
691
692 // We call another function to do the rest so we are sure that the stack addresses used
693 // from there will be lower than the stack base just computed.
694 thread_main_inner();
695 }
696
697 void JavaThread::thread_main_inner() {
698 assert(JavaThread::current() == this, "sanity check");
699 assert(_threadObj.peek() != NULL, "just checking");
700
701 // Execute thread entry point unless this thread has a pending exception.
702 // Note: Due to JVMTI StopThread we can have pending exceptions already!
703 if (!this->has_pending_exception()) {
704 {
705 ResourceMark rm(this);
706 this->set_native_thread_name(this->name());
707 }
708 HandleMark hm(this);
709 this->entry_point()(this, this);
710 }
711
712 DTRACE_THREAD_PROBE(stop, this);
713
714 // Cleanup is handled in post_run()
715 }
716
717 // Shared teardown for all JavaThreads
718 void JavaThread::post_run() {
719 this->exit(false);
720 this->unregister_thread_stack_with_NMT();
721 // Defer deletion to here to ensure 'this' is still referenceable in call_run
722 // for any shared tear-down.
723 this->smr_delete();
724 }
725
726 static void ensure_join(JavaThread* thread) {
727 // We do not need to grab the Threads_lock, since we are operating on ourself.
728 Handle threadObj(thread, thread->threadObj());
729 assert(threadObj.not_null(), "java thread object must exist");
730 ObjectLocker lock(threadObj, thread);
731 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
732 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED);
733 // Clear the native thread instance - this makes isAlive return false and allows the join()
734 // to complete once we've done the notify_all below
735 java_lang_Thread::set_thread(threadObj(), NULL);
736 lock.notify_all(thread);
737 // Ignore pending exception, since we are exiting anyway
738 thread->clear_pending_exception();
739 }
740
741 static bool is_daemon(oop threadObj) {
742 return (threadObj != NULL && java_lang_Thread::is_daemon(threadObj));
743 }
744
745 // For any new cleanup additions, please check to see if they need to be applied to
746 // cleanup_failed_attach_current_thread as well.
747 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
748 assert(this == JavaThread::current(), "thread consistency check");
749 assert(!is_exiting(), "should not be exiting or terminated already");
750
751 elapsedTimer _timer_exit_phase1;
752 elapsedTimer _timer_exit_phase2;
753 elapsedTimer _timer_exit_phase3;
754 elapsedTimer _timer_exit_phase4;
755
756 if (log_is_enabled(Debug, os, thread, timer)) {
757 _timer_exit_phase1.start();
758 }
759
760 HandleMark hm(this);
761 Handle uncaught_exception(this, this->pending_exception());
762 this->clear_pending_exception();
763 Handle threadObj(this, this->threadObj());
764 assert(threadObj.not_null(), "Java thread object should be created");
765
766 if (!destroy_vm) {
767 if (uncaught_exception.not_null()) {
768 EXCEPTION_MARK;
769 // Call method Thread.dispatchUncaughtException().
770 Klass* thread_klass = vmClasses::Thread_klass();
771 JavaValue result(T_VOID);
772 JavaCalls::call_virtual(&result,
773 threadObj, thread_klass,
774 vmSymbols::dispatchUncaughtException_name(),
775 vmSymbols::throwable_void_signature(),
776 uncaught_exception,
777 THREAD);
778 if (HAS_PENDING_EXCEPTION) {
779 ResourceMark rm(this);
780 jio_fprintf(defaultStream::error_stream(),
781 "\nException: %s thrown from the UncaughtExceptionHandler"
782 " in thread \"%s\"\n",
783 pending_exception()->klass()->external_name(),
784 name());
785 CLEAR_PENDING_EXCEPTION;
786 }
787 }
788
789 if (!is_Compiler_thread()) {
790 // We have finished executing user-defined Java code and now have to do the
791 // implementation specific clean-up by calling Thread.exit(). We prevent any
792 // asynchronous exceptions from being delivered while in Thread.exit()
793 // to ensure the clean-up is not corrupted.
794 NoAsyncExceptionDeliveryMark _no_async(this);
795
796 EXCEPTION_MARK;
797 JavaValue result(T_VOID);
798 Klass* thread_klass = vmClasses::Thread_klass();
799 JavaCalls::call_virtual(&result,
800 threadObj, thread_klass,
801 vmSymbols::exit_method_name(),
802 vmSymbols::void_method_signature(),
803 THREAD);
804 CLEAR_PENDING_EXCEPTION;
805 }
806
807 // notify JVMTI
808 if (JvmtiExport::should_post_thread_life()) {
809 JvmtiExport::post_thread_end(this);
810 }
811 } else {
812 // before_exit() has already posted JVMTI THREAD_END events
813 }
814
815 // Cleanup any pending async exception now since we cannot access oops after
816 // BarrierSet::barrier_set()->on_thread_detach() has been executed.
817 if (has_async_exception_condition()) {
818 handshake_state()->clean_async_exception_operation();
819 }
820
821 // The careful dance between thread suspension and exit is handled here.
822 // Since we are in thread_in_vm state and suspension is done with handshakes,
823 // we can just put in the exiting state and it will be correctly handled.
824 // Also, no more async exceptions will be added to the queue after this point.
825 set_terminated(_thread_exiting);
826 ThreadService::current_thread_exiting(this, is_daemon(threadObj()));
827
828 if (log_is_enabled(Debug, os, thread, timer)) {
829 _timer_exit_phase1.stop();
830 _timer_exit_phase2.start();
831 }
832
833 // Capture daemon status before the thread is marked as terminated.
834 bool daemon = is_daemon(threadObj());
835
836 // Notify waiters on thread object. This has to be done after exit() is called
837 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
838 // group should have the destroyed bit set before waiters are notified).
839 ensure_join(this);
840 assert(!this->has_pending_exception(), "ensure_join should have cleared");
841
842 if (log_is_enabled(Debug, os, thread, timer)) {
843 _timer_exit_phase2.stop();
844 _timer_exit_phase3.start();
845 }
846 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
847 // held by this thread must be released. The spec does not distinguish
848 // between JNI-acquired and regular Java monitors. We can only see
849 // regular Java monitors here if monitor enter-exit matching is broken.
850 //
851 // ensure_join() ignores IllegalThreadStateExceptions, and so does
852 // ObjectSynchronizer::release_monitors_owned_by_thread().
853 if (exit_type == jni_detach) {
854 // Sanity check even though JNI DetachCurrentThread() would have
855 // returned JNI_ERR if there was a Java frame. JavaThread exit
856 // should be done executing Java code by the time we get here.
857 assert(!this->has_last_Java_frame(),
858 "should not have a Java frame when detaching or exiting");
859 ObjectSynchronizer::release_monitors_owned_by_thread(this);
860 assert(!this->has_pending_exception(), "release_monitors should have cleared");
861 }
862
863 // Since above code may not release JNI monitors and if someone forgot to do an
864 // JNI monitorexit, held count should be equal jni count.
865 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach).
866 assert(this->held_monitor_count() == this->jni_monitor_count(),
867 "held monitor count should be equal to jni: " INT64_FORMAT " != " INT64_FORMAT,
868 (int64_t)this->held_monitor_count(), (int64_t)this->jni_monitor_count());
869 if (CheckJNICalls && this->jni_monitor_count() > 0) {
870 // We would like a fatal here, but due to we never checked this before there
871 // is a lot of tests which breaks, even with an error log.
872 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.",
873 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id());
874 }
875
876 // These things needs to be done while we are still a Java Thread. Make sure that thread
877 // is in a consistent state, in case GC happens
878 JFR_ONLY(Jfr::on_thread_exit(this);)
879
880 if (active_handles() != NULL) {
881 JNIHandleBlock* block = active_handles();
882 set_active_handles(NULL);
883 JNIHandleBlock::release_block(block);
884 }
885
886 if (free_handle_block() != NULL) {
887 JNIHandleBlock* block = free_handle_block();
888 set_free_handle_block(NULL);
889 JNIHandleBlock::release_block(block);
890 }
891
892 // These have to be removed while this is still a valid thread.
893 _stack_overflow_state.remove_stack_guard_pages();
894
895 if (UseTLAB) {
896 tlab().retire();
897 }
898
899 if (JvmtiEnv::environments_might_exist()) {
900 JvmtiExport::cleanup_thread(this);
901 }
902
903 // We need to cache the thread name for logging purposes below as once
904 // we have called on_thread_detach this thread must not access any oops.
905 char* thread_name = NULL;
906 if (log_is_enabled(Debug, os, thread, timer)) {
907 ResourceMark rm(this);
908 thread_name = os::strdup(name());
909 }
910
911 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
912 exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
913 os::current_thread_id());
914
915 if (log_is_enabled(Debug, os, thread, timer)) {
916 _timer_exit_phase3.stop();
917 _timer_exit_phase4.start();
918 }
919
920 #if INCLUDE_JVMCI
921 if (JVMCICounterSize > 0) {
922 if (jvmci_counters_include(this)) {
923 for (int i = 0; i < JVMCICounterSize; i++) {
924 _jvmci_old_thread_counters[i] += _jvmci_counters[i];
925 }
926 }
927 }
928 #endif // INCLUDE_JVMCI
929
930 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread.
931 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point.
932 Threads::remove(this, daemon);
933
934 if (log_is_enabled(Debug, os, thread, timer)) {
935 _timer_exit_phase4.stop();
936 log_debug(os, thread, timer)("name='%s'"
937 ", exit-phase1=" JLONG_FORMAT
938 ", exit-phase2=" JLONG_FORMAT
939 ", exit-phase3=" JLONG_FORMAT
940 ", exit-phase4=" JLONG_FORMAT,
941 thread_name,
942 _timer_exit_phase1.milliseconds(),
943 _timer_exit_phase2.milliseconds(),
944 _timer_exit_phase3.milliseconds(),
945 _timer_exit_phase4.milliseconds());
946 os::free(thread_name);
947 }
948 }
949
950 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) {
951 if (active_handles() != NULL) {
952 JNIHandleBlock* block = active_handles();
953 set_active_handles(NULL);
954 JNIHandleBlock::release_block(block);
955 }
956
957 if (free_handle_block() != NULL) {
958 JNIHandleBlock* block = free_handle_block();
959 set_free_handle_block(NULL);
960 JNIHandleBlock::release_block(block);
961 }
962
963 // These have to be removed while this is still a valid thread.
964 _stack_overflow_state.remove_stack_guard_pages();
965
966 if (UseTLAB) {
967 tlab().retire();
968 }
969
970 Threads::remove(this, is_daemon);
971 this->smr_delete();
972 }
973
974 JavaThread* JavaThread::active() {
975 Thread* thread = Thread::current();
976 if (thread->is_Java_thread()) {
977 return JavaThread::cast(thread);
978 } else {
979 assert(thread->is_VM_thread(), "this must be a vm thread");
980 VM_Operation* op = ((VMThread*) thread)->vm_operation();
981 JavaThread *ret = op == NULL ? NULL : JavaThread::cast(op->calling_thread());
982 return ret;
983 }
984 }
985
986 bool JavaThread::is_lock_owned(address adr) const {
987 if (Thread::is_lock_owned(adr)) return true;
988
989 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
990 if (chunk->contains(adr)) return true;
991 }
992
993 return false;
994 }
995
996 oop JavaThread::exception_oop() const {
997 return Atomic::load(&_exception_oop);
998 }
999
1000 void JavaThread::set_exception_oop(oop o) {
1001 Atomic::store(&_exception_oop, o);
1002 }
1003
1004 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1005 chunk->set_next(monitor_chunks());
1006 set_monitor_chunks(chunk);
1007 }
1008
1009 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1010 guarantee(monitor_chunks() != NULL, "must be non empty");
1011 if (monitor_chunks() == chunk) {
1012 set_monitor_chunks(chunk->next());
1013 } else {
1014 MonitorChunk* prev = monitor_chunks();
1015 while (prev->next() != chunk) prev = prev->next();
1016 prev->set_next(chunk->next());
1017 }
1018 }
1019
1020 void JavaThread::handle_special_runtime_exit_condition() {
1021 if (is_obj_deopt_suspend()) {
1022 frame_anchor()->make_walkable();
1023 wait_for_object_deoptimization();
1024 }
1025 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);)
1026 }
1027
1028
1029 // Asynchronous exceptions support
1030 //
1031 void JavaThread::handle_async_exception(oop java_throwable) {
1032 assert(java_throwable != NULL, "should have an _async_exception to throw");
1033 assert(!is_at_poll_safepoint(), "should have never called this method");
1034
1035 if (has_last_Java_frame()) {
1036 frame f = last_frame();
1037 if (f.is_runtime_frame()) {
1038 // If the topmost frame is a runtime stub, then we are calling into
1039 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1040 // must deoptimize the caller before continuing, as the compiled exception
1041 // handler table may not be valid.
1042 RegisterMap reg_map(this,
1043 RegisterMap::UpdateMap::skip,
1044 RegisterMap::ProcessFrames::include,
1045 RegisterMap::WalkContinuation::skip);
1046 frame compiled_frame = f.sender(®_map);
1047 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1048 Deoptimization::deoptimize(this, compiled_frame);
1049 }
1050 }
1051 }
1052
1053 // We cannot call Exceptions::_throw(...) here because we cannot block
1054 set_pending_exception(java_throwable, __FILE__, __LINE__);
1055
1056 clear_scopedValueBindings();
1057
1058 LogTarget(Info, exceptions) lt;
1059 if (lt.is_enabled()) {
1060 ResourceMark rm;
1061 LogStream ls(lt);
1062 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
1063 if (has_last_Java_frame()) {
1064 frame f = last_frame();
1065 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
1066 }
1067 ls.print_cr(" of type: %s", java_throwable->klass()->external_name());
1068 }
1069 }
1070
1071 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) {
1072 // Do not throw asynchronous exceptions against the compiler thread
1073 // or if the thread is already exiting.
1074 if (!can_call_java() || is_exiting()) {
1075 delete aeh;
1076 return;
1077 }
1078
1079 oop exception = aeh->exception();
1080 Handshake::execute(aeh, this); // Install asynchronous handshake
1081
1082 ResourceMark rm;
1083 if (log_is_enabled(Info, exceptions)) {
1084 log_info(exceptions)("Pending Async. exception installed of type: %s",
1085 InstanceKlass::cast(exception->klass())->external_name());
1086 }
1087 // for AbortVMOnException flag
1088 Exceptions::debug_check_abort(exception->klass()->external_name());
1089
1090 // Interrupt thread so it will wake up from a potential wait()/sleep()/park()
1091 java_lang_Thread::set_interrupted(threadObj(), true);
1092 this->interrupt();
1093 }
1094
1095 class InstallAsyncExceptionHandshake : public HandshakeClosure {
1096 AsyncExceptionHandshake* _aeh;
1097 public:
1098 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) :
1099 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {}
1100 ~InstallAsyncExceptionHandshake() {
1101 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh.
1102 delete _aeh;
1103 }
1104 void do_thread(Thread* thr) {
1105 JavaThread* target = JavaThread::cast(thr);
1106 target->install_async_exception(_aeh);
1107 _aeh = nullptr;
1108 }
1109 };
1110
1111 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) {
1112 OopHandle e(Universe::vm_global(), java_throwable);
1113 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e));
1114 Handshake::execute(&iaeh, target);
1115 }
1116
1117 #if INCLUDE_JVMTI
1118 void JavaThread::set_is_in_VTMS_transition(bool val) {
1119 _is_in_VTMS_transition = val;
1120 }
1121
1122 #ifdef ASSERT
1123 void JavaThread::set_is_VTMS_transition_disabler(bool val) {
1124 _is_VTMS_transition_disabler = val;
1125 }
1126 #endif
1127 #endif
1128
1129 // External suspension mechanism.
1130 //
1131 // Guarantees on return (for a valid target thread):
1132 // - Target thread will not execute any new bytecode.
1133 // - Target thread will not enter any new monitors.
1134 //
1135 bool JavaThread::java_suspend() {
1136 #if INCLUDE_JVMTI
1137 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks.
1138 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition");
1139 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers");
1140 #endif
1141
1142 guarantee(Thread::is_JavaThread_protected(/* target */ this),
1143 "target JavaThread is not protected in calling context.");
1144 return this->handshake_state()->suspend();
1145 }
1146
1147 bool JavaThread::java_resume() {
1148 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this),
1149 "missing ThreadsListHandle in calling context.");
1150 return this->handshake_state()->resume();
1151 }
1152
1153 // Wait for another thread to perform object reallocation and relocking on behalf of
1154 // this thread. The current thread is required to change to _thread_blocked in order
1155 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming
1156 // handshake safe, the other thread can complete the handshake used to synchronize
1157 // with this thread and then perform the reallocation and relocking.
1158 // See EscapeBarrier::sync_and_suspend_*()
1159
1160 void JavaThread::wait_for_object_deoptimization() {
1161 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack");
1162 assert(this == Thread::current(), "invariant");
1163
1164 bool spin_wait = os::is_MP();
1165 do {
1166 ThreadBlockInVM tbivm(this, true /* allow_suspend */);
1167 // Wait for object deoptimization if requested.
1168 if (spin_wait) {
1169 // A single deoptimization is typically very short. Microbenchmarks
1170 // showed 5% better performance when spinning.
1171 const uint spin_limit = 10 * SpinYield::default_spin_limit;
1172 SpinYield spin(spin_limit);
1173 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) {
1174 spin.wait();
1175 }
1176 // Spin just once
1177 spin_wait = false;
1178 } else {
1179 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag);
1180 if (is_obj_deopt_suspend()) {
1181 ml.wait();
1182 }
1183 }
1184 // A handshake for obj. deoptimization suspend could have been processed so
1185 // we must check after processing.
1186 } while (is_obj_deopt_suspend());
1187 }
1188
1189 #ifdef ASSERT
1190 // Verify the JavaThread has not yet been published in the Threads::list, and
1191 // hence doesn't need protection from concurrent access at this stage.
1192 void JavaThread::verify_not_published() {
1193 // Cannot create a ThreadsListHandle here and check !tlh.includes(this)
1194 // since an unpublished JavaThread doesn't participate in the
1195 // Thread-SMR protocol for keeping a ThreadsList alive.
1196 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!");
1197 }
1198 #endif
1199
1200 // Slow path when the native==>Java barriers detect a safepoint/handshake is
1201 // pending, when _suspend_flags is non-zero or when we need to process a stack
1202 // watermark. Also check for pending async exceptions (except unsafe access error).
1203 // Note only the native==>Java barriers can call this function when thread state
1204 // is _thread_in_native_trans.
1205 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1206 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1207 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition");
1208
1209 thread->set_thread_state(_thread_in_vm);
1210
1211 // Enable WXWrite: called directly from interpreter native wrapper.
1212 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
1213
1214 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */);
1215
1216 // After returning from native, it could be that the stack frames are not
1217 // yet safe to use. We catch such situations in the subsequent stack watermark
1218 // barrier, which will trap unsafe stack frames.
1219 StackWatermarkSet::before_unwind(thread);
1220 }
1221
1222 #ifndef PRODUCT
1223 // Deoptimization
1224 // Function for testing deoptimization
1225 void JavaThread::deoptimize() {
1226 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1227 bool deopt = false; // Dump stack only if a deopt actually happens.
1228 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1229 // Iterate over all frames in the thread and deoptimize
1230 for (; !fst.is_done(); fst.next()) {
1231 if (fst.current()->can_be_deoptimized()) {
1232
1233 if (only_at) {
1234 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1235 // consists of comma or carriage return separated numbers so
1236 // search for the current bci in that string.
1237 address pc = fst.current()->pc();
1238 nmethod* nm = (nmethod*) fst.current()->cb();
1239 ScopeDesc* sd = nm->scope_desc_at(pc);
1240 char buffer[8];
1241 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1242 size_t len = strlen(buffer);
1243 const char * found = strstr(DeoptimizeOnlyAt, buffer);
1244 while (found != NULL) {
1245 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1246 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1247 // Check that the bci found is bracketed by terminators.
1248 break;
1249 }
1250 found = strstr(found + 1, buffer);
1251 }
1252 if (!found) {
1253 continue;
1254 }
1255 }
1256
1257 if (DebugDeoptimization && !deopt) {
1258 deopt = true; // One-time only print before deopt
1259 tty->print_cr("[BEFORE Deoptimization]");
1260 trace_frames();
1261 trace_stack();
1262 }
1263 Deoptimization::deoptimize(this, *fst.current());
1264 }
1265 }
1266
1267 if (DebugDeoptimization && deopt) {
1268 tty->print_cr("[AFTER Deoptimization]");
1269 trace_frames();
1270 }
1271 }
1272
1273
1274 // Make zombies
1275 void JavaThread::make_zombies() {
1276 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1277 if (fst.current()->can_be_deoptimized()) {
1278 // it is a Java nmethod
1279 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1280 nm->make_not_entrant();
1281 }
1282 }
1283 }
1284 #endif // PRODUCT
1285
1286
1287 void JavaThread::deoptimize_marked_methods() {
1288 if (!has_last_Java_frame()) return;
1289 StackFrameStream fst(this, false /* update */, true /* process_frames */);
1290 for (; !fst.is_done(); fst.next()) {
1291 if (fst.current()->should_be_deoptimized()) {
1292 Deoptimization::deoptimize(this, *fst.current());
1293 }
1294 }
1295 }
1296
1297 #ifdef ASSERT
1298 void JavaThread::verify_frame_info() {
1299 assert((!has_last_Java_frame() && java_call_counter() == 0) ||
1300 (has_last_Java_frame() && java_call_counter() > 0),
1301 "unexpected frame info: has_last_frame=%s, java_call_counter=%d",
1302 has_last_Java_frame() ? "true" : "false", java_call_counter());
1303 }
1304 #endif
1305
1306 // Push on a new block of JNI handles.
1307 void JavaThread::push_jni_handle_block() {
1308 // Allocate a new block for JNI handles.
1309 // Inlined code from jni_PushLocalFrame()
1310 JNIHandleBlock* old_handles = active_handles();
1311 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this);
1312 assert(old_handles != NULL && new_handles != NULL, "should not be NULL");
1313 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd.
1314 set_active_handles(new_handles);
1315 }
1316
1317 // Pop off the current block of JNI handles.
1318 void JavaThread::pop_jni_handle_block() {
1319 // Release our JNI handle block
1320 JNIHandleBlock* old_handles = active_handles();
1321 JNIHandleBlock* new_handles = old_handles->pop_frame_link();
1322 assert(new_handles != nullptr, "should never set active handles to null");
1323 set_active_handles(new_handles);
1324 old_handles->set_pop_frame_link(NULL);
1325 JNIHandleBlock::release_block(old_handles, this);
1326 }
1327
1328 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) {
1329 // Verify that the deferred card marks have been flushed.
1330 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1331
1332 // Traverse the GCHandles
1333 Thread::oops_do_no_frames(f, cf);
1334
1335 if (active_handles() != NULL) {
1336 active_handles()->oops_do(f);
1337 }
1338
1339 DEBUG_ONLY(verify_frame_info();)
1340
1341 if (has_last_Java_frame()) {
1342 // Traverse the monitor chunks
1343 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1344 chunk->oops_do(f);
1345 }
1346 }
1347
1348 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
1349 // If we have deferred set_locals there might be oops waiting to be
1350 // written
1351 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this);
1352 if (list != NULL) {
1353 for (int i = 0; i < list->length(); i++) {
1354 list->at(i)->oops_do(f);
1355 }
1356 }
1357
1358 // Traverse instance variables at the end since the GC may be moving things
1359 // around using this function
1360 f->do_oop((oop*) &_vm_result);
1361 f->do_oop((oop*) &_exception_oop);
1362 #if INCLUDE_JVMCI
1363 f->do_oop((oop*) &_jvmci_reserved_oop0);
1364 #endif
1365
1366 if (jvmti_thread_state() != NULL) {
1367 jvmti_thread_state()->oops_do(f, cf);
1368 }
1369
1370 // The continuation oops are really on the stack. But there is typically at most
1371 // one of those per thread, so we handle them here in the oops_do_no_frames part
1372 // so that we don't have to sprinkle as many stack watermark checks where these
1373 // oops are used. We just need to make sure the thread has started processing.
1374 ContinuationEntry* entry = _cont_entry;
1375 while (entry != nullptr) {
1376 f->do_oop((oop*)entry->cont_addr());
1377 f->do_oop((oop*)entry->chunk_addr());
1378 entry = entry->parent();
1379 }
1380 }
1381
1382 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {
1383 if (!has_last_Java_frame()) {
1384 return;
1385 }
1386 // Finish any pending lazy GC activity for the frames
1387 StackWatermarkSet::finish_processing(this, NULL /* context */, StackWatermarkKind::gc);
1388 // Traverse the execution stack
1389 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) {
1390 fst.current()->oops_do(f, cf, fst.register_map());
1391 }
1392 }
1393
1394 #ifdef ASSERT
1395 void JavaThread::verify_states_for_handshake() {
1396 // This checks that the thread has a correct frame state during a handshake.
1397 verify_frame_info();
1398 }
1399 #endif
1400
1401 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1402 DEBUG_ONLY(verify_frame_info();)
1403 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
1404
1405 if (has_last_Java_frame()) {
1406 // Traverse the execution stack
1407 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1408 fst.current()->nmethods_do(cf);
1409 }
1410 }
1411
1412 if (jvmti_thread_state() != NULL) {
1413 jvmti_thread_state()->nmethods_do(cf);
1414 }
1415 }
1416
1417 void JavaThread::metadata_do(MetadataClosure* f) {
1418 if (has_last_Java_frame()) {
1419 // Traverse the execution stack to call f() on the methods in the stack
1420 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1421 fst.current()->metadata_do(f);
1422 }
1423 } else if (is_Compiler_thread()) {
1424 // need to walk ciMetadata in current compile tasks to keep alive.
1425 CompilerThread* ct = (CompilerThread*)this;
1426 if (ct->env() != NULL) {
1427 ct->env()->metadata_do(f);
1428 }
1429 CompileTask* task = ct->task();
1430 if (task != NULL) {
1431 task->metadata_do(f);
1432 }
1433 }
1434 }
1435
1436 // Printing
1437 const char* _get_thread_state_name(JavaThreadState _thread_state) {
1438 switch (_thread_state) {
1439 case _thread_uninitialized: return "_thread_uninitialized";
1440 case _thread_new: return "_thread_new";
1441 case _thread_new_trans: return "_thread_new_trans";
1442 case _thread_in_native: return "_thread_in_native";
1443 case _thread_in_native_trans: return "_thread_in_native_trans";
1444 case _thread_in_vm: return "_thread_in_vm";
1445 case _thread_in_vm_trans: return "_thread_in_vm_trans";
1446 case _thread_in_Java: return "_thread_in_Java";
1447 case _thread_in_Java_trans: return "_thread_in_Java_trans";
1448 case _thread_blocked: return "_thread_blocked";
1449 case _thread_blocked_trans: return "_thread_blocked_trans";
1450 default: return "unknown thread state";
1451 }
1452 }
1453
1454 void JavaThread::print_thread_state_on(outputStream *st) const {
1455 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1456 }
1457
1458 // Called by Threads::print() for VM_PrintThreads operation
1459 void JavaThread::print_on(outputStream *st, bool print_extended_info) const {
1460 st->print_raw("\"");
1461 st->print_raw(name());
1462 st->print_raw("\" ");
1463 oop thread_oop = threadObj();
1464 if (thread_oop != NULL) {
1465 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id());
1466 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1467 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1468 }
1469 Thread::print_on(st, print_extended_info);
1470 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1471 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1472 if (thread_oop != NULL) {
1473 if (is_vthread_mounted()) {
1474 oop vt = vthread();
1475 assert(vt != NULL, "");
1476 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1477 } else {
1478 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1479 }
1480 }
1481 #ifndef PRODUCT
1482 _safepoint_state->print_on(st);
1483 #endif // PRODUCT
1484 if (is_Compiler_thread()) {
1485 CompileTask *task = ((CompilerThread*)this)->task();
1486 if (task != NULL) {
1487 st->print(" Compiling: ");
1488 task->print(st, NULL, true, false);
1489 } else {
1490 st->print(" No compile task");
1491 }
1492 st->cr();
1493 }
1494 }
1495
1496 void JavaThread::print() const { print_on(tty); }
1497
1498 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
1499 st->print("%s", get_thread_name_string(buf, buflen));
1500 }
1501
1502 // Called by fatal error handler. The difference between this and
1503 // JavaThread::print() is that we can't grab lock or allocate memory.
1504 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1505 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen));
1506 Thread* current = Thread::current_or_null_safe();
1507 assert(current != nullptr, "cannot be called by a detached thread");
1508 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1509 // Only access threadObj() if current thread is not a JavaThread
1510 // or if it is a JavaThread that can safely access oops.
1511 oop thread_obj = threadObj();
1512 if (thread_obj != nullptr) {
1513 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
1514 }
1515 }
1516 st->print(" [");
1517 st->print("%s", _get_thread_state_name(_thread_state));
1518 if (osthread()) {
1519 st->print(", id=%d", osthread()->thread_id());
1520 }
1521 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
1522 p2i(stack_end()), p2i(stack_base()));
1523 st->print("]");
1524
1525 ThreadsSMRSupport::print_info_on(this, st);
1526 return;
1527 }
1528
1529
1530 // Verification
1531
1532 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1533 // ignore if there is no stack
1534 if (!has_last_Java_frame()) return;
1535 // traverse the stack frames. Starts from top frame.
1536 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) {
1537 frame* fr = fst.current();
1538 f(fr, fst.register_map());
1539 }
1540 }
1541
1542 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1543
1544 void JavaThread::verify() {
1545 // Verify oops in the thread.
1546 oops_do(&VerifyOopClosure::verify_oop, NULL);
1547
1548 // Verify the stack frames.
1549 frames_do(frame_verify);
1550 }
1551
1552 // CR 6300358 (sub-CR 2137150)
1553 // Most callers of this method assume that it can't return NULL but a
1554 // thread may not have a name whilst it is in the process of attaching to
1555 // the VM - see CR 6412693, and there are places where a JavaThread can be
1556 // seen prior to having its threadObj set (e.g., JNI attaching threads and
1557 // if vm exit occurs during initialization). These cases can all be accounted
1558 // for such that this method never returns NULL.
1559 const char* JavaThread::name() const {
1560 if (Thread::is_JavaThread_protected(/* target */ this)) {
1561 // The target JavaThread is protected so get_thread_name_string() is safe:
1562 return get_thread_name_string();
1563 }
1564
1565 // The target JavaThread is not protected so we return the default:
1566 return Thread::name();
1567 }
1568
1569 // Returns a non-NULL representation of this thread's name, or a suitable
1570 // descriptive string if there is no set name.
1571 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1572 const char* name_str;
1573 #ifdef ASSERT
1574 Thread* current = Thread::current_or_null_safe();
1575 assert(current != nullptr, "cannot be called by a detached thread");
1576 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) {
1577 // Only access threadObj() if current thread is not a JavaThread
1578 // or if it is a JavaThread that can safely access oops.
1579 #endif
1580 oop thread_obj = threadObj();
1581 if (thread_obj != NULL) {
1582 oop name = java_lang_Thread::name(thread_obj);
1583 if (name != NULL) {
1584 if (buf == NULL) {
1585 name_str = java_lang_String::as_utf8_string(name);
1586 } else {
1587 name_str = java_lang_String::as_utf8_string(name, buf, buflen);
1588 }
1589 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1590 name_str = "<no-name - thread is attaching>";
1591 } else {
1592 name_str = "<un-named>";
1593 }
1594 } else {
1595 name_str = Thread::name();
1596 }
1597 #ifdef ASSERT
1598 } else {
1599 // Current JavaThread has exited...
1600 if (current == this) {
1601 // ... and is asking about itself:
1602 name_str = "<no-name - current JavaThread has exited>";
1603 } else {
1604 // ... and it can't safely determine this JavaThread's name so
1605 // use the default thread name.
1606 name_str = Thread::name();
1607 }
1608 }
1609 #endif
1610 assert(name_str != NULL, "unexpected NULL thread name");
1611 return name_str;
1612 }
1613
1614 // Helper to extract the name from the thread oop for logging.
1615 const char* JavaThread::name_for(oop thread_obj) {
1616 assert(thread_obj != NULL, "precondition");
1617 oop name = java_lang_Thread::name(thread_obj);
1618 const char* name_str;
1619 if (name != NULL) {
1620 name_str = java_lang_String::as_utf8_string(name);
1621 } else {
1622 name_str = "<un-named>";
1623 }
1624 return name_str;
1625 }
1626
1627 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1628
1629 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1630 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check");
1631 // Link Java Thread object <-> C++ Thread
1632
1633 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1634 // and put it into a new Handle. The Handle "thread_oop" can then
1635 // be used to pass the C++ thread object to other methods.
1636
1637 // Set the Java level thread object (jthread) field of the
1638 // new thread (a JavaThread *) to C++ thread object using the
1639 // "thread_oop" handle.
1640
1641 // Set the thread field (a JavaThread *) of the
1642 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1643
1644 Handle thread_oop(Thread::current(),
1645 JNIHandles::resolve_non_null(jni_thread));
1646 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1647 "must be initialized");
1648 set_threadOopHandles(thread_oop());
1649 java_lang_Thread::set_thread(thread_oop(), this);
1650
1651 if (prio == NoPriority) {
1652 prio = java_lang_Thread::priority(thread_oop());
1653 assert(prio != NoPriority, "A valid priority should be present");
1654 }
1655
1656 // Push the Java priority down to the native thread; needs Threads_lock
1657 Thread::set_priority(this, prio);
1658
1659 // Add the new thread to the Threads list and set it in motion.
1660 // We must have threads lock in order to call Threads::add.
1661 // It is crucial that we do not block before the thread is
1662 // added to the Threads list for if a GC happens, then the java_thread oop
1663 // will not be visited by GC.
1664 Threads::add(this);
1665 }
1666
1667 oop JavaThread::current_park_blocker() {
1668 // Support for JSR-166 locks
1669 oop thread_oop = threadObj();
1670 if (thread_oop != NULL) {
1671 return java_lang_Thread::park_blocker(thread_oop);
1672 }
1673 return NULL;
1674 }
1675
1676
1677 void JavaThread::print_stack_on(outputStream* st) {
1678 if (!has_last_Java_frame()) return;
1679
1680 Thread* current_thread = Thread::current();
1681 ResourceMark rm(current_thread);
1682 HandleMark hm(current_thread);
1683
1684 RegisterMap reg_map(this,
1685 RegisterMap::UpdateMap::include,
1686 RegisterMap::ProcessFrames::include,
1687 RegisterMap::WalkContinuation::skip);
1688 vframe* start_vf = platform_thread_last_java_vframe(®_map);
1689 int count = 0;
1690 for (vframe* f = start_vf; f != NULL; f = f->sender()) {
1691 if (f->is_java_frame()) {
1692 javaVFrame* jvf = javaVFrame::cast(f);
1693 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1694
1695 // Print out lock information
1696 if (JavaMonitorsInStackTrace) {
1697 jvf->print_lock_info_on(st, count);
1698 }
1699 } else {
1700 // Ignore non-Java frames
1701 }
1702
1703 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0
1704 count++;
1705 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return;
1706 }
1707 }
1708
1709 #if INCLUDE_JVMTI
1710 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1711 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) {
1712 set_jvmti_vthread(thread_oop);
1713
1714 // unbind current JvmtiThreadState from JavaThread
1715 JvmtiThreadState::unbind_from(jvmti_thread_state(), this);
1716
1717 // bind new JvmtiThreadState to JavaThread
1718 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this);
1719
1720 return jvmti_thread_state();
1721 }
1722 #endif
1723
1724 // JVMTI PopFrame support
1725 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1726 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
1727 if (in_bytes(size_in_bytes) != 0) {
1728 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1729 _popframe_preserved_args_size = in_bytes(size_in_bytes);
1730 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1731 }
1732 }
1733
1734 void* JavaThread::popframe_preserved_args() {
1735 return _popframe_preserved_args;
1736 }
1737
1738 ByteSize JavaThread::popframe_preserved_args_size() {
1739 return in_ByteSize(_popframe_preserved_args_size);
1740 }
1741
1742 WordSize JavaThread::popframe_preserved_args_size_in_words() {
1743 int sz = in_bytes(popframe_preserved_args_size());
1744 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1745 return in_WordSize(sz / wordSize);
1746 }
1747
1748 void JavaThread::popframe_free_preserved_args() {
1749 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
1750 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args);
1751 _popframe_preserved_args = NULL;
1752 _popframe_preserved_args_size = 0;
1753 }
1754
1755 #ifndef PRODUCT
1756
1757 void JavaThread::trace_frames() {
1758 tty->print_cr("[Describe stack]");
1759 int frame_no = 1;
1760 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) {
1761 tty->print(" %d. ", frame_no++);
1762 fst.current()->print_value_on(tty, this);
1763 tty->cr();
1764 }
1765 }
1766
1767 class PrintAndVerifyOopClosure: public OopClosure {
1768 protected:
1769 template <class T> inline void do_oop_work(T* p) {
1770 oop obj = RawAccess<>::oop_load(p);
1771 if (obj == NULL) return;
1772 tty->print(INTPTR_FORMAT ": ", p2i(p));
1773 if (oopDesc::is_oop_or_null(obj)) {
1774 if (obj->is_objArray()) {
1775 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
1776 } else {
1777 obj->print();
1778 }
1779 } else {
1780 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
1781 }
1782 tty->cr();
1783 }
1784 public:
1785 virtual void do_oop(oop* p) { do_oop_work(p); }
1786 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1787 };
1788
1789 #ifdef ASSERT
1790 // Print or validate the layout of stack frames
1791 void JavaThread::print_frame_layout(int depth, bool validate_only) {
1792 ResourceMark rm;
1793 PreserveExceptionMark pm(this);
1794 FrameValues values;
1795 int frame_no = 0;
1796 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) {
1797 fst.current()->describe(values, ++frame_no, fst.register_map());
1798 if (depth == frame_no) break;
1799 }
1800 Continuation::describe(values);
1801 if (validate_only) {
1802 values.validate();
1803 } else {
1804 tty->print_cr("[Describe stack layout]");
1805 values.print(this);
1806 }
1807 }
1808 #endif
1809
1810 void JavaThread::trace_stack_from(vframe* start_vf) {
1811 ResourceMark rm;
1812 int vframe_no = 1;
1813 for (vframe* f = start_vf; f; f = f->sender()) {
1814 if (f->is_java_frame()) {
1815 javaVFrame::cast(f)->print_activation(vframe_no++);
1816 } else {
1817 f->print();
1818 }
1819 if (vframe_no > StackPrintLimit) {
1820 tty->print_cr("...<more frames>...");
1821 return;
1822 }
1823 }
1824 }
1825
1826
1827 void JavaThread::trace_stack() {
1828 if (!has_last_Java_frame()) return;
1829 Thread* current_thread = Thread::current();
1830 ResourceMark rm(current_thread);
1831 HandleMark hm(current_thread);
1832 RegisterMap reg_map(this,
1833 RegisterMap::UpdateMap::include,
1834 RegisterMap::ProcessFrames::include,
1835 RegisterMap::WalkContinuation::skip);
1836 trace_stack_from(last_java_vframe(®_map));
1837 }
1838
1839
1840 #endif // PRODUCT
1841
1842 void JavaThread::inc_held_monitor_count(int i, bool jni) {
1843 #ifdef SUPPORT_MONITOR_COUNT
1844 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count);
1845 _held_monitor_count += i;
1846 if (jni) {
1847 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count);
1848 _jni_monitor_count += i;
1849 }
1850 #endif
1851 }
1852
1853 void JavaThread::dec_held_monitor_count(int i, bool jni) {
1854 #ifdef SUPPORT_MONITOR_COUNT
1855 _held_monitor_count -= i;
1856 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count);
1857 if (jni) {
1858 _jni_monitor_count -= i;
1859 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count);
1860 }
1861 #endif
1862 }
1863
1864 frame JavaThread::vthread_last_frame() {
1865 assert (is_vthread_mounted(), "Virtual thread not mounted");
1866 return last_frame();
1867 }
1868
1869 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) {
1870 const ContinuationEntry* entry = vthread_continuation();
1871 guarantee (entry != NULL, "Not a carrier thread");
1872 frame f = entry->to_frame();
1873 if (reg_map->process_frames()) {
1874 entry->flush_stack_processing(this);
1875 }
1876 entry->update_register_map(reg_map);
1877 return f.sender(reg_map);
1878 }
1879
1880 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) {
1881 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame();
1882 }
1883
1884 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) {
1885 assert(reg_map != NULL, "a map must be given");
1886 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
1887 if (vf->is_java_frame()) return javaVFrame::cast(vf);
1888 }
1889 return NULL;
1890 }
1891
1892 Klass* JavaThread::security_get_caller_class(int depth) {
1893 ResetNoHandleMark rnhm;
1894 HandleMark hm(Thread::current());
1895
1896 vframeStream vfst(this);
1897 vfst.security_get_caller_frame(depth);
1898 if (!vfst.at_end()) {
1899 return vfst.method()->method_holder();
1900 }
1901 return NULL;
1902 }
1903
1904 // java.lang.Thread.sleep support
1905 // Returns true if sleep time elapsed as expected, and false
1906 // if the thread was interrupted.
1907 bool JavaThread::sleep(jlong millis) {
1908 assert(this == Thread::current(), "thread consistency check");
1909
1910 ParkEvent * const slp = this->_SleepEvent;
1911 // Because there can be races with thread interruption sending an unpark()
1912 // to the event, we explicitly reset it here to avoid an immediate return.
1913 // The actual interrupt state will be checked before we park().
1914 slp->reset();
1915 // Thread interruption establishes a happens-before ordering in the
1916 // Java Memory Model, so we need to ensure we synchronize with the
1917 // interrupt state.
1918 OrderAccess::fence();
1919
1920 jlong prevtime = os::javaTimeNanos();
1921
1922 for (;;) {
1923 // interruption has precedence over timing out
1924 if (this->is_interrupted(true)) {
1925 return false;
1926 }
1927
1928 if (millis <= 0) {
1929 return true;
1930 }
1931
1932 {
1933 ThreadBlockInVM tbivm(this);
1934 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1935 slp->park(millis);
1936 }
1937
1938 // Update elapsed time tracking
1939 jlong newtime = os::javaTimeNanos();
1940 if (newtime - prevtime < 0) {
1941 // time moving backwards, should only happen if no monotonic clock
1942 // not a guarantee() because JVM should not abort on kernel/glibc bugs
1943 assert(false,
1944 "unexpected time moving backwards detected in JavaThread::sleep()");
1945 } else {
1946 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
1947 }
1948 prevtime = newtime;
1949 }
1950 }
1951
1952 // Last thread running calls java.lang.Shutdown.shutdown()
1953 void JavaThread::invoke_shutdown_hooks() {
1954 HandleMark hm(this);
1955
1956 // We could get here with a pending exception, if so clear it now or
1957 // it will cause MetaspaceShared::link_shared_classes to
1958 // fail for dynamic dump.
1959 if (this->has_pending_exception()) {
1960 this->clear_pending_exception();
1961 }
1962
1963 #if INCLUDE_CDS
1964 // Link all classes for dynamic CDS dumping before vm exit.
1965 // Same operation is being done in JVM_BeforeHalt for handling the
1966 // case where the application calls System.exit().
1967 if (DynamicArchive::should_dump_at_vm_exit()) {
1968 DynamicArchive::prepare_for_dump_at_exit();
1969 }
1970 #endif
1971
1972 EXCEPTION_MARK;
1973 Klass* shutdown_klass =
1974 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
1975 THREAD);
1976 if (shutdown_klass != NULL) {
1977 // SystemDictionary::resolve_or_null will return null if there was
1978 // an exception. If we cannot load the Shutdown class, just don't
1979 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
1980 // won't be run. Note that if a shutdown hook was registered,
1981 // the Shutdown class would have already been loaded
1982 // (Runtime.addShutdownHook will load it).
1983 JavaValue result(T_VOID);
1984 JavaCalls::call_static(&result,
1985 shutdown_klass,
1986 vmSymbols::shutdown_name(),
1987 vmSymbols::void_method_signature(),
1988 THREAD);
1989 }
1990 CLEAR_PENDING_EXCEPTION;
1991 }
1992
1993 #ifndef PRODUCT
1994 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) {
1995 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread);
1996 }
1997 #endif
1998
1999 // Helper function to create the java.lang.Thread object for a
2000 // VM-internal thread. The thread will have the given name, and be
2001 // a member of the "system" ThreadGroup.
2002 Handle JavaThread::create_system_thread_object(const char* name,
2003 bool is_visible, TRAPS) {
2004 Handle string = java_lang_String::create_from_str(name, CHECK_NH);
2005
2006 // Initialize thread_oop to put it into the system threadGroup.
2007 // This is done by calling the Thread(ThreadGroup group, String name) constructor.
2008 Handle thread_group(THREAD, Universe::system_thread_group());
2009 Handle thread_oop =
2010 JavaCalls::construct_new_instance(vmClasses::Thread_klass(),
2011 vmSymbols::threadgroup_string_void_signature(),
2012 thread_group,
2013 string,
2014 CHECK_NH);
2015
2016 return thread_oop;
2017 }
2018
2019 // Starts the target JavaThread as a daemon of the given priority, and
2020 // bound to the given java.lang.Thread instance.
2021 // The Threads_lock is held for the duration.
2022 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target,
2023 Handle thread_oop, ThreadPriority prio) {
2024
2025 assert(target->osthread() != NULL, "target thread is not properly initialized");
2026
2027 MutexLocker mu(current, Threads_lock);
2028
2029 // Initialize the fields of the thread_oop first.
2030
2031 java_lang_Thread::set_thread(thread_oop(), target); // isAlive == true now
2032
2033 if (prio != NoPriority) {
2034 java_lang_Thread::set_priority(thread_oop(), prio);
2035 // Note: we don't call os::set_priority here. Possibly we should,
2036 // else all threads should call it themselves when they first run.
2037 }
2038
2039 java_lang_Thread::set_daemon(thread_oop());
2040
2041 // Now bind the thread_oop to the target JavaThread.
2042 target->set_threadOopHandles(thread_oop());
2043
2044 Threads::add(target); // target is now visible for safepoint/handshake
2045 Thread::start(target);
2046 }
2047
2048 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) {
2049 // At this point it may be possible that no osthread was created for the
2050 // JavaThread due to lack of resources. However, since this must work
2051 // for critical system threads just check and abort if this fails.
2052 if (thread->osthread() == nullptr) {
2053 // This isn't really an OOM condition, but historically this is what
2054 // we report.
2055 vm_exit_during_initialization("java.lang.OutOfMemoryError",
2056 os::native_thread_creation_failed_msg());
2057 }
2058 }
2059
2060 // Deferred OopHandle release support.
2061
2062 class OopHandleList : public CHeapObj<mtInternal> {
2063 static const int _count = 4;
2064 OopHandle _handles[_count];
2065 OopHandleList* _next;
2066 int _index;
2067 public:
2068 OopHandleList(OopHandleList* next) : _next(next), _index(0) {}
2069 void add(OopHandle h) {
2070 assert(_index < _count, "too many additions");
2071 _handles[_index++] = h;
2072 }
2073 ~OopHandleList() {
2074 assert(_index == _count, "usage error");
2075 for (int i = 0; i < _index; i++) {
2076 _handles[i].release(JavaThread::thread_oop_storage());
2077 }
2078 }
2079 OopHandleList* next() const { return _next; }
2080 };
2081
2082 OopHandleList* JavaThread::_oop_handle_list = nullptr;
2083
2084 // Called by the ServiceThread to do the work of releasing
2085 // the OopHandles.
2086 void JavaThread::release_oop_handles() {
2087 OopHandleList* list;
2088 {
2089 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2090 list = _oop_handle_list;
2091 _oop_handle_list = nullptr;
2092 }
2093 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint");
2094
2095 while (list != nullptr) {
2096 OopHandleList* l = list;
2097 list = l->next();
2098 delete l;
2099 }
2100 }
2101
2102 // Add our OopHandles for later release.
2103 void JavaThread::add_oop_handles_for_release() {
2104 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
2105 OopHandleList* new_head = new OopHandleList(_oop_handle_list);
2106 new_head->add(_threadObj);
2107 new_head->add(_vthread);
2108 new_head->add(_jvmti_vthread);
2109 new_head->add(_scopedValueCache);
2110 _oop_handle_list = new_head;
2111 Service_lock->notify_all();
2112 }