1 /*
2 * Copyright (c) 1997, 2026, 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 #ifndef SHARE_RUNTIME_JAVATHREAD_HPP
27 #define SHARE_RUNTIME_JAVATHREAD_HPP
28
29 #ifndef PRODUCT
30 #include "interpreter/bytecodeTracer.hpp"
31 #endif // PRODUCT
32 #include "jni.h"
33 #include "memory/allocation.hpp"
34 #include "oops/oop.hpp"
35 #include "oops/oopHandle.hpp"
36 #include "runtime/continuationEntry.hpp"
37 #include "runtime/frame.hpp"
38 #include "runtime/globals.hpp"
39 #include "runtime/handshake.hpp"
40 #include "runtime/javaFrameAnchor.hpp"
41 #include "runtime/lockStack.hpp"
42 #include "runtime/park.hpp"
43 #include "runtime/safepointMechanism.hpp"
44 #include "runtime/stackOverflow.hpp"
45 #include "runtime/stackWatermarkSet.hpp"
46 #include "runtime/suspendResumeManager.hpp"
47 #include "runtime/thread.hpp"
48 #include "runtime/threadHeapSampler.hpp"
49 #include "runtime/threadIdentifier.hpp"
50 #include "runtime/threadStatisticalInfo.hpp"
51 #include "utilities/exceptions.hpp"
52 #include "utilities/globalDefinitions.hpp"
53 #include "utilities/macros.hpp"
54 #if INCLUDE_JFR
55 #include "jfr/support/jfrThreadExtension.hpp"
56 #include "utilities/ticks.hpp"
57 #endif
58
59 class AsyncExceptionHandshakeClosure;
60 class DeoptResourceMark;
61 class InternalOOMEMark;
62 class JNIHandleBlock;
63 class JVMCIRuntime;
64
65 class JvmtiDeferredUpdates;
66 class JvmtiSampledObjectAllocEventCollector;
67 class JvmtiThreadState;
68
69 class Metadata;
70 class ObjectMonitor;
71 class OopHandleList;
72 class OopStorage;
73 class OSThread;
74
75 class ThreadsList;
76 class ThreadSafepointState;
77 class ThreadStatistics;
78
79 class vframeArray;
80 class vframe;
81 class javaVFrame;
82
83 class JavaThread;
84 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
85
86 class EventVirtualThreadPinned;
87 class ThreadWXEnable;
88
89 class JavaThread: public Thread {
90 friend class VMStructs;
91 friend class JVMCIVMStructs;
92 friend class WhiteBox;
93 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
94 friend class HandshakeState;
95 friend class Continuation;
96 friend class Threads;
97 friend class ServiceThread; // for deferred OopHandle release access
98 private:
99 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
100
101 // All references to Java objects managed via OopHandles. These
102 // have to be released by the ServiceThread after the JavaThread has
103 // terminated - see add_oop_handles_for_release().
104 OopHandle _threadObj; // The Java level thread object
105 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj
106 OopHandle _jvmti_vthread;
107 OopHandle _scopedValueCache;
108
109 static OopStorage* _thread_oop_storage;
110
111 #ifdef ASSERT
112 private:
113 int _java_call_counter;
114
115 public:
116 int java_call_counter() { return _java_call_counter; }
117 void inc_java_call_counter() { _java_call_counter++; }
118 void dec_java_call_counter() {
119 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
120 _java_call_counter--;
121 }
122 private: // restore original namespace restriction
123 #endif // ifdef ASSERT
124
125 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
126
127 ThreadFunction _entry_point;
128
129 JNIEnv _jni_environment;
130
131 // Deopt support
132 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
133
134 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
135 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
136 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
137 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
138 // will be carried out as soon as possible which, in most cases, is just before deoptimization of
139 // the frame, when control returns to it.
140 JvmtiDeferredUpdates* _jvmti_deferred_updates;
141
142 // Handshake value for fixing 6243940. We need a place for the i2c
143 // adapter to store the callee Method*. This value is NEVER live
144 // across a gc point so it does NOT have to be gc'd
145 // The handshake is open ended since we can't be certain that it will
146 // be nulled. This is because we rarely ever see the race and end up
147 // in handle_wrong_method which is the backend of the handshake. See
148 // code in i2c adapters and handle_wrong_method.
149
150 Method* _callee_target;
151
152 // Used to pass back results to the interpreter or generated code running Java code.
153 oop _vm_result_oop; // oop result is GC-preserved
154 Metadata* _vm_result_metadata; // non-oop result
155
156 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
157 bool _current_pending_monitor_is_from_java; // locking is from Java code
158 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
159
160 // Active_handles points to a block of handles
161 JNIHandleBlock* _active_handles;
162
163 // One-element thread local free list
164 JNIHandleBlock* _free_handle_block;
165
166 // ID used as owner for inflated monitors. Same as the j.l.Thread.tid of the
167 // current _vthread object, except during creation of the primordial and JNI
168 // attached thread cases where this field can have a temporary value.
169 int64_t _monitor_owner_id;
170
171 public:
172 void set_monitor_owner_id(int64_t id) {
173 ThreadIdentifier::verify_id(id);
174 _monitor_owner_id = id;
175 }
176 int64_t monitor_owner_id() const {
177 int64_t id = _monitor_owner_id;
178 ThreadIdentifier::verify_id(id);
179 return id;
180 }
181
182 // For tracking the heavyweight monitor the thread is pending on.
183 ObjectMonitor* current_pending_monitor() {
184 // Use AtomicAccess::load() to prevent data race between concurrent modification and
185 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
186 // Especially, reloading pointer from thread after null check must be prevented.
187 return AtomicAccess::load(&_current_pending_monitor);
188 }
189 void set_current_pending_monitor(ObjectMonitor* monitor) {
190 AtomicAccess::store(&_current_pending_monitor, monitor);
191 }
192 void set_current_pending_monitor_is_from_java(bool from_java) {
193 _current_pending_monitor_is_from_java = from_java;
194 }
195 bool current_pending_monitor_is_from_java() {
196 return _current_pending_monitor_is_from_java;
197 }
198 ObjectMonitor* current_waiting_monitor() {
199 // See the comment in current_pending_monitor() above.
200 return AtomicAccess::load(&_current_waiting_monitor);
201 }
202 void set_current_waiting_monitor(ObjectMonitor* monitor) {
203 AtomicAccess::store(&_current_waiting_monitor, monitor);
204 }
205
206 // JNI handle support
207 JNIHandleBlock* active_handles() const { return _active_handles; }
208 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
209 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
210 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
211
212 void push_jni_handle_block();
213 void pop_jni_handle_block();
214
215 private:
216 enum SuspendFlags {
217 // NOTE: avoid using the sign-bit as cc generates different test code
218 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
219 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
220 };
221
222 // various suspension related flags - atomically updated
223 volatile uint32_t _suspend_flags;
224
225 inline void set_suspend_flag(SuspendFlags f);
226 inline void clear_suspend_flag(SuspendFlags f);
227
228 public:
229 inline void set_obj_deopt_flag();
230 inline void clear_obj_deopt_flag();
231 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
232
233 // Asynchronous exception support
234 private:
235 friend class InstallAsyncExceptionHandshakeClosure;
236 friend class AsyncExceptionHandshakeClosure;
237 friend class HandshakeState;
238
239 void handle_async_exception(oop java_throwable);
240 public:
241 void install_async_exception(AsyncExceptionHandshakeClosure* aec = nullptr);
242 bool has_async_exception_condition();
243 inline void set_pending_unsafe_access_error();
244 static void send_async_exception(JavaThread* jt, oop java_throwable);
245
246 class NoAsyncExceptionDeliveryMark : public StackObj {
247 friend JavaThread;
248 JavaThread *_target;
249 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
250 inline ~NoAsyncExceptionDeliveryMark();
251 };
252
253 // Safepoint support
254 public: // Expose _thread_state for SafeFetchInt()
255 volatile JavaThreadState _thread_state;
256 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
257 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
258 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
259 #ifdef ASSERT
260 // Debug support for checking if code allows safepoints or not.
261 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
262 // mutex, or blocking on an object synchronizer (Java locking).
263 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
264 // the above cases. The class NoSafepointVerifier is used to set this counter.
265 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
266
267 public:
268 void inc_no_safepoint_count() { _no_safepoint_count++; }
269 void dec_no_safepoint_count() { _no_safepoint_count--; }
270 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
271 #endif // ASSERT
272 public:
273 // These functions check conditions before possibly going to a safepoint.
274 // including NoSafepointVerifier.
275 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
276 void check_possible_safepoint() NOT_DEBUG_RETURN;
277
278 #ifdef ASSERT
279 private:
280 volatile uint64_t _visited_for_critical_count;
281
282 public:
283 void set_visited_for_critical_count(uint64_t safepoint_id) {
284 assert(_visited_for_critical_count == 0, "Must be reset before set");
285 assert((safepoint_id & 0x1) == 1, "Must be odd");
286 _visited_for_critical_count = safepoint_id;
287 }
288 void reset_visited_for_critical_count(uint64_t safepoint_id) {
289 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
290 _visited_for_critical_count = 0;
291 }
292 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
293 return _visited_for_critical_count == safepoint_id;
294 }
295 #endif // ASSERT
296
297 #ifndef PRODUCT
298 private:
299 BytecodeTracerData _bytecode_tracer_data;
300
301 public:
302 BytecodeTracerData* bytecode_tracer_data() {
303 return &_bytecode_tracer_data;
304 }
305 #endif // PRODUCT
306
307 // JavaThread termination support
308 public:
309 enum TerminatedTypes {
310 _not_terminated = 0xDEAD - 3,
311 _thread_exiting, // JavaThread::exit() has been called for this thread
312 _thread_gc_barrier_detached, // thread's GC barrier has been detached
313 _thread_terminated, // JavaThread is removed from thread list
314 _vm_exited // JavaThread is still executing native code, but VM is terminated
315 // only VM_Exit can set _vm_exited
316 };
317
318 private:
319 // In general a JavaThread's _terminated field transitions as follows:
320 //
321 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
322 //
323 // _vm_exited is a special value to cover the case of a JavaThread
324 // executing native code after the VM itself is terminated.
325 //
326 // A JavaThread that fails to JNI attach has these _terminated field transitions:
327 // _not_terminated => _thread_terminated
328 //
329 volatile TerminatedTypes _terminated;
330
331 jint _in_deopt_handler; // count of deoptimization
332 // handlers thread is in
333 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
334 volatile bool _throwing_unsafe_access_error; // Thread has faulted and is throwing an exception
335 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
336 // never locked) when throwing an exception. Used by interpreter only.
337 #if INCLUDE_JVMTI
338 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
339 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
340 bool _is_in_java_upcall; // JVMTI is doing a Java upcall, so JVMTI events must be hidden
341 int _jvmti_events_disabled; // JVMTI events disabled manually
342 bool _on_monitor_waited_event; // Avoid callee arg processing for enterSpecial when posting waited event
343 ObjectMonitor* _contended_entered_monitor; // Monitor for pending monitor_contended_entered callback
344 #endif
345
346 // JNI attach states:
347 enum JNIAttachStates {
348 _not_attaching_via_jni = 1, // thread is not attaching via JNI
349 _attaching_via_jni, // thread is attaching via JNI
350 _attached_via_jni // thread has attached via JNI
351 };
352
353 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
354 // A native thread that is attaching via JNI starts with a value
355 // of _attaching_via_jni and transitions to _attached_via_jni.
356 volatile JNIAttachStates _jni_attach_state;
357
358 // In scope of an InternalOOMEMark?
359 bool _is_in_internal_oome_mark;
360
361 #if INCLUDE_JVMCI
362 // The _pending_* fields below are used to communicate extra information
363 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
364
365 // Communicates the DeoptReason and DeoptAction of the uncommon trap
366 int _pending_deoptimization;
367
368 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
369 // before the monitor has been acquired.
370 bool _pending_monitorenter;
371
372 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
373 bool _pending_transfer_to_interpreter;
374
375 // An id of a speculation that JVMCI compiled code can use to further describe and
376 // uniquely identify the speculative optimization guarded by an uncommon trap.
377 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
378 jlong _pending_failed_speculation;
379
380 // These fields are mutually exclusive in terms of live ranges.
381 union {
382 // Communicates the pc at which the most recent implicit exception occurred
383 // from the signal handler to a deoptimization stub.
384 address _implicit_exception_pc;
385
386 // Communicates an alternative call target to an i2c stub from a JavaCall .
387 address _alternate_call_target;
388 } _jvmci;
389
390 // The JVMCIRuntime in a JVMCI shared library
391 JVMCIRuntime* _libjvmci_runtime;
392
393 // Support for high precision, thread sensitive counters in JVMCI compiled code.
394 jlong* _jvmci_counters;
395
396 // Fast thread locals for use by JVMCI
397 jlong _jvmci_reserved0;
398 jlong _jvmci_reserved1;
399 oop _jvmci_reserved_oop0;
400
401 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
402 // be kept alive
403 nmethod* _live_nmethod;
404
405 public:
406 static jlong* _jvmci_old_thread_counters;
407 static void collect_counters(jlong* array, int length);
408
409 bool resize_counters(int current_size, int new_size);
410
411 static bool resize_all_jvmci_counters(int new_size);
412
413 void set_jvmci_reserved_oop0(oop value) {
414 _jvmci_reserved_oop0 = value;
415 }
416
417 oop get_jvmci_reserved_oop0() {
418 return _jvmci_reserved_oop0;
419 }
420
421 void set_jvmci_reserved0(jlong value) {
422 _jvmci_reserved0 = value;
423 }
424
425 jlong get_jvmci_reserved0() {
426 return _jvmci_reserved0;
427 }
428
429 void set_jvmci_reserved1(jlong value) {
430 _jvmci_reserved1 = value;
431 }
432
433 jlong get_jvmci_reserved1() {
434 return _jvmci_reserved1;
435 }
436
437 void set_live_nmethod(nmethod* nm) {
438 assert(_live_nmethod == nullptr, "only one");
439 _live_nmethod = nm;
440 }
441
442 void clear_live_nmethod() {
443 _live_nmethod = nullptr;
444 }
445
446 private:
447 #endif // INCLUDE_JVMCI
448
449 StackOverflow _stack_overflow_state;
450
451 void pretouch_stack();
452
453 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
454 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
455 // code)
456 volatile oop _exception_oop; // Exception thrown in compiled code
457 volatile address _exception_pc; // PC where exception happened
458 volatile address _exception_handler_pc; // PC for handler of exception
459
460 private:
461 // support for JNI critical regions
462 jint _jni_active_critical; // count of entries into JNI critical region
463
464 // Checked JNI: function name requires exception check
465 char* _pending_jni_exception_check_fn;
466
467 // For deadlock detection.
468 int _depth_first_number;
469
470 // JVMTI PopFrame support
471 // This is set to popframe_pending to signal that top Java frame should be popped immediately
472 int _popframe_condition;
473
474 // If reallocation of scalar replaced objects fails, we throw OOM
475 // and during exception propagation, pop the top
476 // _frames_to_pop_failed_realloc frames, the ones that reference
477 // failed reallocations.
478 int _frames_to_pop_failed_realloc;
479
480 ContinuationEntry* _cont_entry;
481 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub/upcall_stub/native_wrapper
482 // frame inside the continuation that we know about
483 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
484
485 ObjectMonitor* _unlocked_inflated_monitor;
486
487 // This is the field we poke in the interpreter and native
488 // wrapper (Object.wait) to check for preemption.
489 address _preempt_alternate_return;
490 // When preempting on monitorenter we could have acquired the
491 // monitor after freezing all vthread frames. In that case we
492 // set this field so that in the preempt stub we call thaw again
493 // instead of unmounting.
494 bool _preemption_cancelled;
495 // For Object.wait() we set this field to know if we need to
496 // throw IE at the end of thawing before returning to Java.
497 bool _pending_interrupted_exception;
498 // We allow preemption on some klass initialization calls.
499 // We use this boolean to mark such calls.
500 bool _at_preemptable_init;
501
502 public:
503 bool preemption_cancelled() { return _preemption_cancelled; }
504 void set_preemption_cancelled(bool b) { _preemption_cancelled = b; }
505
506 bool pending_interrupted_exception() { return _pending_interrupted_exception; }
507 void set_pending_interrupted_exception(bool b) { _pending_interrupted_exception = b; }
508
509 bool preempting() { return _preempt_alternate_return != nullptr; }
510 void set_preempt_alternate_return(address val) { _preempt_alternate_return = val; }
511
512 bool at_preemptable_init() { return _at_preemptable_init; }
513 void set_at_preemptable_init(bool b) { _at_preemptable_init = b; }
514
515 #ifdef ASSERT
516 // Used for extra logging with -Xlog:continuation+preempt
517 InstanceKlass* _preempt_init_klass;
518
519 InstanceKlass* preempt_init_klass() { return _preempt_init_klass; }
520 void set_preempt_init_klass(InstanceKlass* ik) { _preempt_init_klass = ik; }
521
522 int _interp_at_preemptable_vmcall_cnt;
523 int interp_at_preemptable_vmcall_cnt() { return _interp_at_preemptable_vmcall_cnt; }
524
525 bool _interp_redoing_vm_call;
526 bool interp_redoing_vm_call() const { return _interp_redoing_vm_call; };
527
528 class AtRedoVMCall : public StackObj {
529 JavaThread* _thread;
530 public:
531 AtRedoVMCall(JavaThread* t) : _thread(t) {
532 assert(!_thread->_interp_redoing_vm_call, "");
533 _thread->_interp_redoing_vm_call = true;
534 _thread->_interp_at_preemptable_vmcall_cnt++;
535 assert(_thread->_interp_at_preemptable_vmcall_cnt > 0, "Unexpected count: %d",
536 _thread->_interp_at_preemptable_vmcall_cnt);
537 }
538 ~AtRedoVMCall() {
539 assert(_thread->_interp_redoing_vm_call, "");
540 _thread->_interp_redoing_vm_call = false;
541 _thread->_interp_at_preemptable_vmcall_cnt--;
542 assert(_thread->_interp_at_preemptable_vmcall_cnt >= 0, "Unexpected count: %d",
543 _thread->_interp_at_preemptable_vmcall_cnt);
544 }
545 };
546 #endif // ASSERT
547
548 private:
549 friend class VMThread;
550 friend class ThreadWaitTransition;
551 friend class VM_Exit;
552
553 // Stack watermark barriers.
554 StackWatermarks _stack_watermarks;
555
556 public:
557 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
558
559 public:
560 // Constructor
561 JavaThread(MemTag mem_tag = mtThread); // delegating constructor
562 JavaThread(ThreadFunction entry_point, size_t stack_size = 0, MemTag mem_tag = mtThread);
563 ~JavaThread();
564
565 // Factory method to create a new JavaThread whose attach state is "is attaching"
566 static JavaThread* create_attaching_thread();
567
568 #ifdef ASSERT
569 // verify this JavaThread hasn't be published in the Threads::list yet
570 void verify_not_published();
571 #endif // ASSERT
572
573 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
574
575 //JNI functiontable getter/setter for JVMTI jni function table interception API.
576 void set_jni_functions(struct JNINativeInterface_* functionTable) {
577 _jni_environment.functions = functionTable;
578 }
579 struct JNINativeInterface_* get_jni_functions() {
580 return (struct JNINativeInterface_ *)_jni_environment.functions;
581 }
582
583 // This function is called at thread creation to allow
584 // platform specific thread variables to be initialized.
585 void cache_global_variables();
586
587 // Executes Shutdown.shutdown()
588 void invoke_shutdown_hooks();
589
590 // Cleanup on thread exit
591 enum ExitType {
592 normal_exit,
593 jni_detach
594 };
595 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
596
597 void cleanup_failed_attach_current_thread(bool is_daemon);
598
599 // Testers
600 virtual bool is_Java_thread() const { return true; }
601 virtual bool can_call_java() const { return true; }
602
603 virtual bool is_active_Java_thread() const;
604
605 // Thread oop. threadObj() can be null for initial JavaThread
606 // (or for threads attached via JNI)
607 oop threadObj() const;
608 void set_threadOopHandles(oop p);
609 oop vthread() const;
610 void set_vthread(oop p);
611 oop scopedValueCache() const;
612 void set_scopedValueCache(oop p);
613 void clear_scopedValueBindings();
614 oop jvmti_vthread() const;
615 void set_jvmti_vthread(oop p);
616 oop vthread_or_thread() const;
617
618 // Prepare thread and add to priority queue. If a priority is
619 // not specified, use the priority of the thread object. Threads_lock
620 // must be held while this function is called.
621 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
622
623 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
624 address saved_exception_pc() { return _saved_exception_pc; }
625
626 ThreadFunction entry_point() const { return _entry_point; }
627
628 // Allocates a new Java level thread object for this thread. thread_name may be null.
629 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
630
631 // Last frame anchor routines
632
633 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
634
635 // last_Java_sp
636 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
637 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
638
639 // last_Java_pc
640
641 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
642
643 // Safepoint support
644 inline JavaThreadState thread_state() const;
645 inline void set_thread_state(JavaThreadState s);
646 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
647 inline ThreadSafepointState* safepoint_state() const;
648 inline void set_safepoint_state(ThreadSafepointState* state);
649 inline bool is_at_poll_safepoint();
650
651 // JavaThread termination and lifecycle support:
652 void smr_delete();
653 bool on_thread_list() const { return _on_thread_list; }
654 void set_on_thread_list() { _on_thread_list = true; }
655
656 // thread has called JavaThread::exit(), thread's GC barrier is detached
657 // or thread is terminated
658 bool is_exiting() const;
659 // thread's GC barrier is NOT detached and thread is NOT terminated
660 bool is_oop_safe() const;
661 // thread is terminated (no longer on the threads list); the thread must
662 // be protected by a ThreadsListHandle to avoid potential crashes.
663 bool check_is_terminated(TerminatedTypes l_terminated) const {
664 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
665 }
666 bool is_terminated() const;
667 void set_terminated(TerminatedTypes t);
668
669 void block_if_vm_exited();
670
671 bool doing_unsafe_access() { return _doing_unsafe_access; }
672 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
673
674 bool is_throwing_unsafe_access_error() { return _throwing_unsafe_access_error; }
675 void set_throwing_unsafe_access_error(bool val) { _throwing_unsafe_access_error = val; }
676
677 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
678 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
679
680 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
681
682 static ByteSize polling_word_offset() {
683 ByteSize offset = byte_offset_of(Thread, _poll_data) +
684 byte_offset_of(SafepointMechanism::ThreadData, _polling_word);
685 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
686 assert(in_bytes(offset) < 128, "Offset >= 128");
687 return offset;
688 }
689
690 static ByteSize polling_page_offset() {
691 ByteSize offset = byte_offset_of(Thread, _poll_data) +
692 byte_offset_of(SafepointMechanism::ThreadData, _polling_page);
693 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
694 assert(in_bytes(offset) < 128, "Offset >= 128");
695 return offset;
696 }
697
698 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
699
700 // Continuation support
701 ContinuationEntry* last_continuation() const { return _cont_entry; }
702 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
703 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
704 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
705 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
706 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
707 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
708
709 // Support for SharedRuntime::monitor_exit_helper()
710 ObjectMonitor* unlocked_inflated_monitor() const { return _unlocked_inflated_monitor; }
711 void clear_unlocked_inflated_monitor() {
712 _unlocked_inflated_monitor = nullptr;
713 }
714
715 inline bool is_vthread_mounted() const;
716 inline const ContinuationEntry* vthread_continuation() const;
717
718 private:
719 DEBUG_ONLY(void verify_frame_info();)
720
721 // Support for thread handshake operations
722 HandshakeState _handshake;
723 public:
724 HandshakeState* handshake_state() { return &_handshake; }
725
726 // A JavaThread can always safely operate on it self and other threads
727 // can do it safely if they are the active handshaker.
728 bool is_handshake_safe_for(Thread* th) const {
729 return _handshake.active_handshaker() == th || this == th;
730 }
731
732 // Suspend/resume support for JavaThread
733 // higher-level suspension/resume logic called by the public APIs
734 private:
735 SuspendResumeManager _suspend_resume_manager;
736 public:
737 bool java_suspend(bool register_vthread_SR);
738 bool java_resume(bool register_vthread_SR);
739 bool is_suspended() { return _suspend_resume_manager.is_suspended(); }
740 SuspendResumeManager* suspend_resume_manager() { return &_suspend_resume_manager; }
741
742 // Check for async exception in addition to safepoint.
743 static void check_special_condition_for_native_trans(JavaThread *thread);
744
745 // Synchronize with another thread that is deoptimizing objects of the
746 // current thread, i.e. reverts optimizations based on escape analysis.
747 void wait_for_object_deoptimization();
748
749 private:
750 bool _is_in_vthread_transition; // thread is in virtual thread mount state transition
751 JVMTI_ONLY(bool _is_vthread_transition_disabler;) // thread currently disabled vthread transitions
752 DEBUG_ONLY(bool _is_disabler_at_start;) // thread at process of disabling vthread transitions
753 public:
754 bool is_in_vthread_transition() const;
755 void set_is_in_vthread_transition(bool val);
756 JVMTI_ONLY(bool is_vthread_transition_disabler() const { return _is_vthread_transition_disabler; })
757 JVMTI_ONLY(void set_is_vthread_transition_disabler(bool val);)
758 #ifdef ASSERT
759 bool is_disabler_at_start() const { return _is_disabler_at_start; }
760 void set_is_disabler_at_start(bool val);
761 #endif
762
763 #if INCLUDE_JVMTI
764 inline bool set_carrier_thread_suspended();
765 inline bool clear_carrier_thread_suspended();
766
767 bool is_carrier_thread_suspended() const {
768 return AtomicAccess::load(&_carrier_thread_suspended);
769 }
770
771 bool is_disable_suspend() const { return _is_disable_suspend; }
772 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; }
773
774 bool is_in_java_upcall() const { return _is_in_java_upcall; }
775 void toggle_is_in_java_upcall() { _is_in_java_upcall = !_is_in_java_upcall; }
776
777 void disable_jvmti_events() { _jvmti_events_disabled++; }
778 void enable_jvmti_events() { _jvmti_events_disabled--; }
779
780 // Temporarily skip posting JVMTI events for safety reasons when executions is in a critical section:
781 // - is in a vthread transition (_is_in_vthread_transition)
782 // - is in an interruptLock or similar critical section (_is_disable_suspend)
783 // - JVMTI is making a Java upcall (_is_in_java_upcall)
784 bool should_hide_jvmti_events() const {
785 return _is_in_vthread_transition || _is_disable_suspend || _is_in_java_upcall || _jvmti_events_disabled != 0;
786 }
787
788 bool on_monitor_waited_event() { return _on_monitor_waited_event; }
789 void set_on_monitor_waited_event(bool val) { _on_monitor_waited_event = val; }
790
791 bool pending_contended_entered_event() { return _contended_entered_monitor != nullptr; }
792 ObjectMonitor* contended_entered_monitor() { return _contended_entered_monitor; }
793 #endif
794
795 void set_contended_entered_monitor(ObjectMonitor* val) NOT_JVMTI_RETURN JVMTI_ONLY({ _contended_entered_monitor = val; })
796
797 // Support for object deoptimization and JFR suspension
798 void handle_special_runtime_exit_condition();
799 bool has_special_runtime_exit_condition() {
800 return (_suspend_flags & _obj_deopt) != 0;
801 }
802
803 // Accessors for vframe array top
804 // The linked list of vframe arrays are sorted on sp. This means when we
805 // unpack the head must contain the vframe array to unpack.
806 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
807 vframeArray* vframe_array_head() const { return _vframe_array_head; }
808
809 // Side structure for deferring update of java frame locals until deopt occurs
810 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
811 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
812
813 // These only really exist to make debugging deopt problems simpler
814
815 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
816 vframeArray* vframe_array_last() const { return _vframe_array_last; }
817
818 // The special resourceMark used during deoptimization
819
820 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
821 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
822
823 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
824 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
825
826 Method* callee_target() const { return _callee_target; }
827 void set_callee_target (Method* x) { _callee_target = x; }
828
829 // Oop results of vm runtime calls
830 oop vm_result_oop() const { return _vm_result_oop; }
831 void set_vm_result_oop(oop x) { _vm_result_oop = x; }
832
833 void set_vm_result_metadata(Metadata* x) { _vm_result_metadata = x; }
834
835 // Is thread in scope of an InternalOOMEMark?
836 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
837 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
838
839 #if INCLUDE_JVMCI
840 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
841 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
842 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
843 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
844 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
845 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
846 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
847
848 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
849 void set_libjvmci_runtime(JVMCIRuntime* rt) {
850 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
851 _libjvmci_runtime = rt;
852 }
853 #endif // INCLUDE_JVMCI
854
855 // Exception handling for compiled methods
856 oop exception_oop() const;
857 address exception_pc() const { return _exception_pc; }
858
859 void set_exception_oop(oop o);
860 void set_exception_pc(address a) { _exception_pc = a; }
861 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
862
863 void clear_exception_oop_and_pc() {
864 set_exception_oop(nullptr);
865 set_exception_pc(nullptr);
866 }
867
868 // Check if address is in the usable part of the stack (excludes protected
869 // guard pages). Can be applied to any thread and is an approximation for
870 // using is_in_live_stack when the query has to happen from another thread.
871 bool is_in_usable_stack(address adr) const {
872 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
873 }
874
875 // Misc. accessors/mutators
876 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
877
878 // For assembly stub generation
879 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
880 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
881 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
882 static ByteSize pending_jni_exception_check_fn_offset() {
883 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
884 }
885 static ByteSize last_Java_sp_offset() {
886 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
887 }
888 static ByteSize last_Java_pc_offset() {
889 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
890 }
891 static ByteSize frame_anchor_offset() {
892 return byte_offset_of(JavaThread, _anchor);
893 }
894 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
895 static ByteSize vm_result_oop_offset() { return byte_offset_of(JavaThread, _vm_result_oop); }
896 static ByteSize vm_result_metadata_offset() { return byte_offset_of(JavaThread, _vm_result_metadata); }
897 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
898 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
899 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
900 #if INCLUDE_JVMCI
901 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
902 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
903 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
904 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
905 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
906 #endif // INCLUDE_JVMCI
907 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
908 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
909 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
910
911 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
912
913 // StackOverflow offsets
914 static ByteSize stack_overflow_limit_offset() {
915 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
916 }
917 static ByteSize stack_guard_state_offset() {
918 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
919 }
920 static ByteSize reserved_stack_activation_offset() {
921 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
922 }
923 static ByteSize shadow_zone_safe_limit() {
924 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
925 }
926 static ByteSize shadow_zone_growth_watermark() {
927 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
928 }
929
930 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
931
932 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
933 static ByteSize should_post_on_exceptions_flag_offset() {
934 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
935 }
936 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
937 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
938
939 static ByteSize monitor_owner_id_offset() { return byte_offset_of(JavaThread, _monitor_owner_id); }
940
941 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
942 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
943 static ByteSize preemption_cancelled_offset() { return byte_offset_of(JavaThread, _preemption_cancelled); }
944 static ByteSize preempt_alternate_return_offset() { return byte_offset_of(JavaThread, _preempt_alternate_return); }
945 DEBUG_ONLY(static ByteSize interp_at_preemptable_vmcall_cnt_offset() { return byte_offset_of(JavaThread, _interp_at_preemptable_vmcall_cnt); })
946 static ByteSize unlocked_inflated_monitor_offset() { return byte_offset_of(JavaThread, _unlocked_inflated_monitor); }
947 static ByteSize is_in_vthread_transition_offset() { return byte_offset_of(JavaThread, _is_in_vthread_transition); }
948
949 #if INCLUDE_JVMTI
950 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
951 #endif
952
953 // Returns the jni environment for this thread
954 JNIEnv* jni_environment() { return &_jni_environment; }
955
956 // Returns the current thread as indicated by the given JNIEnv.
957 // We don't assert it is Thread::current here as that is done at the
958 // external JNI entry points where the JNIEnv is passed into the VM.
959 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
960 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
961 // We can't normally get here in a thread that has completed its
962 // execution and so "is_terminated", except when the call is from
963 // AsyncGetCallTrace, which can be triggered by a signal at any point in
964 // a thread's lifecycle. A thread is also considered terminated if the VM
965 // has exited, so we have to check this and block in case this is a daemon
966 // thread returning to the VM (the JNI DirectBuffer entry points rely on
967 // this).
968 if (current->is_terminated()) {
969 current->block_if_vm_exited();
970 }
971 return current;
972 }
973
974 // JNI critical regions. These can nest.
975 bool in_critical() { return _jni_active_critical > 0; }
976 bool in_last_critical() { return _jni_active_critical == 1; }
977 inline void enter_critical();
978 void exit_critical() {
979 assert(Thread::current() == this, "this must be current thread");
980 _jni_active_critical--;
981 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
982 }
983
984 // Atomic version; invoked by a thread other than the owning thread.
985 bool in_critical_atomic() { return AtomicAccess::load(&_jni_active_critical) > 0; }
986
987 // Checked JNI: is the programmer required to check for exceptions, if so specify
988 // which function name. Returning to a Java frame should implicitly clear the
989 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
990 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
991 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
992 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
993 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
994 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
995 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
996
997 // For deadlock detection
998 int depth_first_number() { return _depth_first_number; }
999 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1000
1001 public:
1002 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1003 void inc_in_deopt_handler() { _in_deopt_handler++; }
1004 void dec_in_deopt_handler() {
1005 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1006 if (_in_deopt_handler > 0) { // robustness
1007 _in_deopt_handler--;
1008 }
1009 }
1010
1011 private:
1012 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1013
1014 // factor out low-level mechanics for use in both normal and error cases
1015 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
1016
1017 public:
1018
1019 // Frame iteration; calls the function f for all frames on the stack
1020 void frames_do(void f(frame*, const RegisterMap*));
1021
1022 // Memory operations
1023 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
1024 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
1025
1026 // GC operations
1027 virtual void nmethods_do(NMethodClosure* cf);
1028
1029 // RedefineClasses Support
1030 void metadata_do(MetadataClosure* f);
1031
1032 // Debug method asserting thread states are correct during a handshake operation.
1033 DEBUG_ONLY(void verify_states_for_handshake();)
1034
1035 // Misc. operations
1036 const char* name() const;
1037 const char* name_raw() const;
1038 const char* type_name() const { return "JavaThread"; }
1039 static const char* name_for(oop thread_obj);
1040
1041 void print_on(outputStream* st, bool print_extended_info) const;
1042 void print_on(outputStream* st) const { print_on(st, false); }
1043 void print() const;
1044 void print_thread_state_on(outputStream*) const;
1045 void print_on_error(outputStream* st, char* buf, int buflen) const;
1046 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1047 void verify();
1048
1049 // Accessing frames
1050 frame last_frame() {
1051 _anchor.make_walkable();
1052 return pd_last_frame();
1053 }
1054 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
1055
1056 frame carrier_last_frame(RegisterMap* reg_map);
1057 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
1058
1059 frame vthread_last_frame();
1060 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
1061
1062 frame platform_thread_last_frame(RegisterMap* reg_map);
1063 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
1064 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
1065 }
1066
1067 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
1068
1069 // Returns method at 'depth' java or native frames down the stack
1070 // Used for security checks
1071 Klass* security_get_caller_class(int depth);
1072
1073 // Print stack trace in external format
1074 // These variants print carrier/platform thread information only.
1075 void print_stack_on(outputStream* st);
1076 void print_stack() { print_stack_on(tty); }
1077 // This prints the currently mounted virtual thread.
1078 void print_vthread_stack_on(outputStream* st);
1079 // This prints the active stack: either carrier/platform or virtual.
1080 void print_active_stack_on(outputStream* st);
1081 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1082 // This is the external format from above, but selecting the platform
1083 // or vthread as applicable.
1084 void print_jni_stack();
1085
1086 // Print stack traces in various internal formats
1087 void trace_stack() PRODUCT_RETURN;
1088 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1089 void trace_frames() PRODUCT_RETURN;
1090
1091 // Print an annotated view of the stack frames
1092 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1093 void validate_frame_layout() {
1094 print_frame_layout(0, true);
1095 }
1096
1097 // Function for testing deoptimization
1098 void deoptimize();
1099 void make_zombies();
1100
1101 void deoptimize_marked_methods();
1102
1103 public:
1104 // Returns the running thread as a JavaThread
1105 static JavaThread* current() {
1106 return JavaThread::cast(Thread::current());
1107 }
1108
1109 // Returns the current thread as a JavaThread, or nullptr if not attached
1110 static inline JavaThread* current_or_null();
1111
1112 // Casts
1113 static JavaThread* cast(Thread* t) {
1114 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
1115 return static_cast<JavaThread*>(t);
1116 }
1117
1118 static const JavaThread* cast(const Thread* t) {
1119 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1120 return static_cast<const JavaThread*>(t);
1121 }
1122
1123 // Returns the active Java thread. Do not use this if you know you are calling
1124 // from a JavaThread, as it's slower than JavaThread::current. If called from
1125 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1126 // operation. You may not want that either.
1127 static JavaThread* active();
1128
1129 protected:
1130 virtual void pre_run();
1131 virtual void run();
1132 void thread_main_inner();
1133 virtual void post_run();
1134
1135 public:
1136 // Thread local information maintained by JVMTI.
1137 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1138 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1139 // getter is used to get this JavaThread's JvmtiThreadState if it has
1140 // one which means null can be returned. JvmtiThreadState::state_for()
1141 // is used to get the specified JavaThread's JvmtiThreadState if it has
1142 // one or it allocates a new JvmtiThreadState for the JavaThread and
1143 // returns it. JvmtiThreadState::state_for() will return null only if
1144 // the specified JavaThread is exiting.
1145 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1146 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1147
1148 #if INCLUDE_JVMTI
1149 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1150 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1151 #endif
1152
1153 // JVMTI PopFrame support
1154 // Setting and clearing popframe_condition
1155 // All of these enumerated values are bits. popframe_pending
1156 // indicates that a PopFrame() has been requested and not yet been
1157 // completed. popframe_processing indicates that that PopFrame() is in
1158 // the process of being completed. popframe_force_deopt_reexecution_bit
1159 // indicates that special handling is required when returning to a
1160 // deoptimized caller.
1161 enum PopCondition {
1162 popframe_inactive = 0x00,
1163 popframe_pending_bit = 0x01,
1164 popframe_processing_bit = 0x02,
1165 popframe_force_deopt_reexecution_bit = 0x04
1166 };
1167 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1168 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1169 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1170 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1171 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1172 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1173 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1174
1175 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1176 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1177 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1178
1179 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1180 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1181 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1182
1183 private:
1184 // Saved incoming arguments to popped frame.
1185 // Used only when popped interpreted frame returns to deoptimized frame.
1186 void* _popframe_preserved_args;
1187 int _popframe_preserved_args_size;
1188
1189 public:
1190 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1191 void* popframe_preserved_args();
1192 ByteSize popframe_preserved_args_size();
1193 WordSize popframe_preserved_args_size_in_words();
1194 void popframe_free_preserved_args();
1195
1196
1197 private:
1198 JvmtiThreadState *_jvmti_thread_state;
1199
1200 // Used by the interpreter in fullspeed mode for frame pop, method
1201 // entry, method exit and single stepping support. This field is
1202 // only set to non-zero at a safepoint or using a direct handshake
1203 // (see EnterInterpOnlyModeHandshakeClosure).
1204 // It can be set to zero asynchronously to this threads execution (i.e., without
1205 // safepoint/handshake or a lock) so we have to be very careful.
1206 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1207 // This field is checked by the interpreter which expects it to be an integer.
1208 int _interp_only_mode;
1209
1210 public:
1211 // used by the interpreter for fullspeed debugging support (see above)
1212 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1213 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1214 void set_interp_only_mode(bool val) { _interp_only_mode = val ? 1 : 0; }
1215
1216 // support for cached flag that indicates whether exceptions need to be posted for this thread
1217 // if this is false, we can avoid deoptimizing when events are thrown
1218 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1219 private:
1220 int _should_post_on_exceptions_flag;
1221
1222 public:
1223 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1224
1225 private:
1226 ThreadStatistics *_thread_stat;
1227
1228 public:
1229 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1230
1231 // Return a blocker object for which this thread is blocked parking.
1232 oop current_park_blocker();
1233
1234 private:
1235 static size_t _stack_size_at_create;
1236
1237 public:
1238 static inline size_t stack_size_at_create(void) {
1239 return _stack_size_at_create;
1240 }
1241 static inline void set_stack_size_at_create(size_t value) {
1242 _stack_size_at_create = value;
1243 }
1244
1245 // Machine dependent stuff
1246 #include OS_CPU_HEADER(javaThread)
1247
1248 // JSR166 per-thread parker
1249 private:
1250 Parker _parker;
1251 public:
1252 Parker* parker() { return &_parker; }
1253
1254 public:
1255 // clearing/querying jni attach status
1256 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1257 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1258 inline void set_done_attaching_via_jni();
1259
1260 // Stack dump assistance:
1261 // Track the class we want to initialize but for which we have to wait
1262 // on its init_lock() because it is already being initialized.
1263 void set_class_to_be_initialized(InstanceKlass* k);
1264 InstanceKlass* class_to_be_initialized() const;
1265
1266 // Track executing class initializer, see ThreadInClassInitializer
1267 void set_class_being_initialized(InstanceKlass* k);
1268 InstanceKlass* class_being_initialized() const;
1269
1270 private:
1271 InstanceKlass* _class_to_be_initialized;
1272 InstanceKlass* _class_being_initialized;
1273
1274 // java.lang.Thread.sleep support
1275 ParkEvent * _SleepEvent;
1276
1277 #if INCLUDE_JFR
1278 // Support for jdk.VirtualThreadPinned event
1279 freeze_result _last_freeze_fail_result;
1280 Ticks _last_freeze_fail_time;
1281 #endif
1282
1283 public:
1284 bool sleep(jlong millis);
1285 bool sleep_nanos(jlong nanos);
1286
1287 // java.lang.Thread interruption support
1288 void interrupt();
1289 bool is_interrupted(bool clear_interrupted);
1290
1291 #if INCLUDE_JFR
1292 // Support for jdk.VirtualThreadPinned event
1293 freeze_result last_freeze_fail_result() { return _last_freeze_fail_result; }
1294 Ticks& last_freeze_fail_time() { return _last_freeze_fail_time; }
1295 void set_last_freeze_fail_result(freeze_result result);
1296 #endif
1297 void post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) NOT_JFR_RETURN();
1298
1299
1300 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1301 // the Java code in Object::wait which are not present in RawMonitorWait.
1302 bool get_and_clear_interrupted();
1303
1304 private:
1305
1306 #ifdef MACOS_AARCH64
1307 friend class ThreadWXEnable;
1308 friend class PosixSignals;
1309
1310 ThreadWXEnable* _cur_wx_enable;
1311 WXMode* _cur_wx_mode;
1312 #endif
1313
1314 LockStack _lock_stack;
1315 OMCache _om_cache;
1316
1317 public:
1318 LockStack& lock_stack() { return _lock_stack; }
1319
1320 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1321 // Those offsets are used in code generators to access the LockStack that is embedded in this
1322 // JavaThread structure. Those accesses are relative to the current thread, which
1323 // is typically in a dedicated register.
1324 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1325 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1326
1327 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); }
1328 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); }
1329
1330 void om_set_monitor_cache(ObjectMonitor* monitor);
1331 void om_clear_monitor_cache();
1332 ObjectMonitor* om_get_from_monitor_cache(oop obj);
1333
1334 static OopStorage* thread_oop_storage();
1335
1336 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1337
1338 // Helper function to create the java.lang.Thread object for a
1339 // VM-internal thread. The thread will have the given name and be
1340 // part of the System ThreadGroup.
1341 static Handle create_system_thread_object(const char* name, TRAPS);
1342
1343 // Helper function to start a VM-internal daemon thread.
1344 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1345 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1346 Handle thread_oop, ThreadPriority prio);
1347
1348 // Helper function to do vm_exit_on_initialization for osthread
1349 // resource allocation failure.
1350 static void vm_exit_on_osthread_failure(JavaThread* thread);
1351
1352 // Deferred OopHandle release support
1353 private:
1354 // List of OopHandles to be released - guarded by the Service_lock.
1355 static OopHandleList* _oop_handle_list;
1356 // Add our OopHandles to the list for the service thread to release.
1357 void add_oop_handles_for_release();
1358 // Called by the ServiceThread to release the OopHandles.
1359 static void release_oop_handles();
1360 // Called by the ServiceThread to poll if there are any OopHandles to release.
1361 // Called when holding the Service_lock.
1362 static bool has_oop_handles_to_release() {
1363 return _oop_handle_list != nullptr;
1364 }
1365 };
1366
1367 inline JavaThread* JavaThread::current_or_null() {
1368 Thread* current = Thread::current_or_null();
1369 return current != nullptr ? JavaThread::cast(current) : nullptr;
1370 }
1371
1372 class UnlockFlagSaver {
1373 private:
1374 JavaThread* _thread;
1375 bool _do_not_unlock;
1376 public:
1377 UnlockFlagSaver(JavaThread* t) {
1378 _thread = t;
1379 _do_not_unlock = t->do_not_unlock_if_synchronized();
1380 t->set_do_not_unlock_if_synchronized(false);
1381 }
1382 ~UnlockFlagSaver() {
1383 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1384 }
1385 };
1386
1387 class JNIHandleMark : public StackObj {
1388 JavaThread* _thread;
1389 public:
1390 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1391 thread->push_jni_handle_block();
1392 }
1393 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1394 };
1395
1396 class NoPreemptMark {
1397 ContinuationEntry* _ce;
1398 bool _unpin;
1399 public:
1400 NoPreemptMark(JavaThread* thread, bool ignore_mark = false) : _ce(thread->last_continuation()), _unpin(false) {
1401 if (_ce != nullptr && !ignore_mark) _unpin = _ce->pin();
1402 }
1403 ~NoPreemptMark() { if (_unpin) _ce->unpin(); }
1404 };
1405
1406 class ThreadOnMonitorWaitedEvent {
1407 JavaThread* _thread;
1408 public:
1409 ThreadOnMonitorWaitedEvent(JavaThread* thread) : _thread(thread) {
1410 JVMTI_ONLY(_thread->set_on_monitor_waited_event(true);)
1411 }
1412 ~ThreadOnMonitorWaitedEvent() { JVMTI_ONLY(_thread->set_on_monitor_waited_event(false);) }
1413 };
1414
1415 class ThreadInClassInitializer : public StackObj {
1416 JavaThread* _thread;
1417 InstanceKlass* _previous;
1418 public:
1419 ThreadInClassInitializer(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
1420 _previous = _thread->class_being_initialized();
1421 _thread->set_class_being_initialized(ik);
1422 }
1423 ~ThreadInClassInitializer() {
1424 _thread->set_class_being_initialized(_previous);
1425 }
1426 };
1427
1428 class ThrowingUnsafeAccessError : public StackObj {
1429 JavaThread* _thread;
1430 bool _prev;
1431 public:
1432 ThrowingUnsafeAccessError(JavaThread* thread) :
1433 _thread(thread),
1434 _prev(thread->is_throwing_unsafe_access_error()) {
1435 _thread->set_throwing_unsafe_access_error(true);
1436 }
1437 ~ThrowingUnsafeAccessError() {
1438 _thread->set_throwing_unsafe_access_error(_prev);
1439 }
1440 };
1441
1442 #endif // SHARE_RUNTIME_JAVATHREAD_HPP