1 /*
2 * Copyright (c) 1997, 2025, 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 #include "jni.h"
30 #include "memory/allocation.hpp"
31 #include "oops/oop.hpp"
32 #include "oops/oopHandle.hpp"
33 #include "runtime/continuationEntry.hpp"
34 #include "runtime/frame.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handshake.hpp"
37 #include "runtime/javaFrameAnchor.hpp"
38 #include "runtime/lockStack.hpp"
39 #include "runtime/park.hpp"
40 #include "runtime/safepointMechanism.hpp"
41 #include "runtime/stackOverflow.hpp"
42 #include "runtime/stackWatermarkSet.hpp"
43 #include "runtime/suspendResumeManager.hpp"
44 #include "runtime/thread.hpp"
45 #include "runtime/threadHeapSampler.hpp"
46 #include "runtime/threadIdentifier.hpp"
47 #include "runtime/threadStatisticalInfo.hpp"
48 #include "utilities/exceptions.hpp"
49 #include "utilities/globalDefinitions.hpp"
50 #include "utilities/macros.hpp"
51 #if INCLUDE_JFR
52 #include "jfr/support/jfrThreadExtension.hpp"
53 #include "utilities/ticks.hpp"
54 #endif
55
56 class AsyncExceptionHandshakeClosure;
57 class DeoptResourceMark;
58 class InternalOOMEMark;
59 class JNIHandleBlock;
60 class JVMCIRuntime;
61
62 class JvmtiDeferredUpdates;
63 class JvmtiSampledObjectAllocEventCollector;
64 class JvmtiThreadState;
65
66 class Metadata;
67 class ObjectMonitor;
68 class OopHandleList;
69 class OopStorage;
70 class OSThread;
71
72 class ThreadsList;
73 class ThreadSafepointState;
74 class ThreadStatistics;
75
76 class vframeArray;
77 class vframe;
78 class javaVFrame;
79
80 class JavaThread;
81 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
82
83 class EventVirtualThreadPinned;
84
85 class JavaThread: public Thread {
86 friend class VMStructs;
87 friend class JVMCIVMStructs;
88 friend class WhiteBox;
89 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
90 friend class HandshakeState;
91 friend class Continuation;
92 friend class Threads;
93 friend class ServiceThread; // for deferred OopHandle release access
94 private:
95 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
96
97 // All references to Java objects managed via OopHandles. These
98 // have to be released by the ServiceThread after the JavaThread has
99 // terminated - see add_oop_handles_for_release().
100 OopHandle _threadObj; // The Java level thread object
101 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj
102 OopHandle _jvmti_vthread;
103 OopHandle _scopedValueCache;
104
105 static OopStorage* _thread_oop_storage;
106
107 #ifdef ASSERT
108 private:
109 int _java_call_counter;
110
111 public:
112 int java_call_counter() { return _java_call_counter; }
113 void inc_java_call_counter() { _java_call_counter++; }
114 void dec_java_call_counter() {
115 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
116 _java_call_counter--;
117 }
118 private: // restore original namespace restriction
119 #endif // ifdef ASSERT
120
121 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
122
123 ThreadFunction _entry_point;
124
125 JNIEnv _jni_environment;
126
127 // Deopt support
128 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
129
130 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
131 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
132 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
133 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
134 // will be carried out as soon as possible which, in most cases, is just before deoptimization of
135 // the frame, when control returns to it.
136 JvmtiDeferredUpdates* _jvmti_deferred_updates;
137
138 // Handshake value for fixing 6243940. We need a place for the i2c
139 // adapter to store the callee Method*. This value is NEVER live
140 // across a gc point so it does NOT have to be gc'd
141 // The handshake is open ended since we can't be certain that it will
142 // be nulled. This is because we rarely ever see the race and end up
143 // in handle_wrong_method which is the backend of the handshake. See
144 // code in i2c adapters and handle_wrong_method.
145
146 Method* _callee_target;
147
148 // Used to pass back results to the interpreter or generated code running Java code.
149 oop _vm_result_oop; // oop result is GC-preserved
150 Metadata* _vm_result_metadata; // non-oop result
151 oop _return_buffered_value; // buffered value being returned
152
153 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
154 bool _current_pending_monitor_is_from_java; // locking is from Java code
155 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
156
157 // Active_handles points to a block of handles
158 JNIHandleBlock* _active_handles;
159
160 // One-element thread local free list
161 JNIHandleBlock* _free_handle_block;
162
163 // ID used as owner for inflated monitors. Same as the j.l.Thread.tid of the
164 // current _vthread object, except during creation of the primordial and JNI
165 // attached thread cases where this field can have a temporary value.
166 int64_t _monitor_owner_id;
167
168 public:
169 void set_monitor_owner_id(int64_t id) {
170 ThreadIdentifier::verify_id(id);
171 _monitor_owner_id = id;
172 }
173 int64_t monitor_owner_id() const {
174 int64_t id = _monitor_owner_id;
175 ThreadIdentifier::verify_id(id);
176 return id;
177 }
178
179 // For tracking the heavyweight monitor the thread is pending on.
180 ObjectMonitor* current_pending_monitor() {
181 // Use AtomicAccess::load() to prevent data race between concurrent modification and
182 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
183 // Especially, reloading pointer from thread after null check must be prevented.
184 return AtomicAccess::load(&_current_pending_monitor);
185 }
186 void set_current_pending_monitor(ObjectMonitor* monitor) {
187 AtomicAccess::store(&_current_pending_monitor, monitor);
188 }
189 void set_current_pending_monitor_is_from_java(bool from_java) {
190 _current_pending_monitor_is_from_java = from_java;
191 }
192 bool current_pending_monitor_is_from_java() {
193 return _current_pending_monitor_is_from_java;
194 }
195 ObjectMonitor* current_waiting_monitor() {
196 // See the comment in current_pending_monitor() above.
197 return AtomicAccess::load(&_current_waiting_monitor);
198 }
199 void set_current_waiting_monitor(ObjectMonitor* monitor) {
200 AtomicAccess::store(&_current_waiting_monitor, monitor);
201 }
202
203 // JNI handle support
204 JNIHandleBlock* active_handles() const { return _active_handles; }
205 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
206 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
207 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
208
209 void push_jni_handle_block();
210 void pop_jni_handle_block();
211
212 private:
213 enum SuspendFlags {
214 // NOTE: avoid using the sign-bit as cc generates different test code
215 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
216 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
217 };
218
219 // various suspension related flags - atomically updated
220 volatile uint32_t _suspend_flags;
221
222 inline void set_suspend_flag(SuspendFlags f);
223 inline void clear_suspend_flag(SuspendFlags f);
224
225 public:
226 inline void set_obj_deopt_flag();
227 inline void clear_obj_deopt_flag();
228 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
229
230 // Asynchronous exception support
231 private:
232 friend class InstallAsyncExceptionHandshakeClosure;
233 friend class AsyncExceptionHandshakeClosure;
234 friend class HandshakeState;
235
236 void handle_async_exception(oop java_throwable);
237 public:
238 void install_async_exception(AsyncExceptionHandshakeClosure* aec = nullptr);
239 bool has_async_exception_condition();
240 inline void set_pending_unsafe_access_error();
241 static void send_async_exception(JavaThread* jt, oop java_throwable);
242
243 class NoAsyncExceptionDeliveryMark : public StackObj {
244 friend JavaThread;
245 JavaThread *_target;
246 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
247 inline ~NoAsyncExceptionDeliveryMark();
248 };
249
250 // Safepoint support
251 public: // Expose _thread_state for SafeFetchInt()
252 volatile JavaThreadState _thread_state;
253 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
254 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
255 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
256 #ifdef ASSERT
257 // Debug support for checking if code allows safepoints or not.
258 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
259 // mutex, or blocking on an object synchronizer (Java locking).
260 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
261 // the above cases. The class NoSafepointVerifier is used to set this counter.
262 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
263
264 public:
265 void inc_no_safepoint_count() { _no_safepoint_count++; }
266 void dec_no_safepoint_count() { _no_safepoint_count--; }
267 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
268 #endif // ASSERT
269 public:
270 // These functions check conditions before possibly going to a safepoint.
271 // including NoSafepointVerifier.
272 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
273 void check_possible_safepoint() NOT_DEBUG_RETURN;
274
275 #ifdef ASSERT
276 private:
277 volatile uint64_t _visited_for_critical_count;
278
279 public:
280 void set_visited_for_critical_count(uint64_t safepoint_id) {
281 assert(_visited_for_critical_count == 0, "Must be reset before set");
282 assert((safepoint_id & 0x1) == 1, "Must be odd");
283 _visited_for_critical_count = safepoint_id;
284 }
285 void reset_visited_for_critical_count(uint64_t safepoint_id) {
286 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
287 _visited_for_critical_count = 0;
288 }
289 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
290 return _visited_for_critical_count == safepoint_id;
291 }
292 #endif // ASSERT
293
294 // JavaThread termination support
295 public:
296 enum TerminatedTypes {
297 _not_terminated = 0xDEAD - 3,
298 _thread_exiting, // JavaThread::exit() has been called for this thread
299 _thread_gc_barrier_detached, // thread's GC barrier has been detached
300 _thread_terminated, // JavaThread is removed from thread list
301 _vm_exited // JavaThread is still executing native code, but VM is terminated
302 // only VM_Exit can set _vm_exited
303 };
304
305 private:
306 // In general a JavaThread's _terminated field transitions as follows:
307 //
308 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
309 //
310 // _vm_exited is a special value to cover the case of a JavaThread
311 // executing native code after the VM itself is terminated.
312 //
313 // A JavaThread that fails to JNI attach has these _terminated field transitions:
314 // _not_terminated => _thread_terminated
315 //
316 volatile TerminatedTypes _terminated;
317
318 jint _in_deopt_handler; // count of deoptimization
319 // handlers thread is in
320 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
321 volatile bool _throwing_unsafe_access_error; // Thread has faulted and is throwing an exception
322 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
323 // never locked) when throwing an exception. Used by interpreter only.
324 #if INCLUDE_JVMTI
325 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
326 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
327 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
328 bool _is_in_java_upcall; // JVMTI is doing a Java upcall, so JVMTI events must be hidden
329 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers
330 bool _on_monitor_waited_event; // Avoid callee arg processing for enterSpecial when posting waited event
331 ObjectMonitor* _contended_entered_monitor; // Monitor for pending monitor_contended_entered callback
332 #ifdef ASSERT
333 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
334 #endif
335 #endif
336
337 // JNI attach states:
338 enum JNIAttachStates {
339 _not_attaching_via_jni = 1, // thread is not attaching via JNI
340 _attaching_via_jni, // thread is attaching via JNI
341 _attached_via_jni // thread has attached via JNI
342 };
343
344 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
345 // A native thread that is attaching via JNI starts with a value
346 // of _attaching_via_jni and transitions to _attached_via_jni.
347 volatile JNIAttachStates _jni_attach_state;
348
349 // In scope of an InternalOOMEMark?
350 bool _is_in_internal_oome_mark;
351
352 #if INCLUDE_JVMCI
353 // The _pending_* fields below are used to communicate extra information
354 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
355
356 // Communicates the DeoptReason and DeoptAction of the uncommon trap
357 int _pending_deoptimization;
358
359 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
360 // before the monitor has been acquired.
361 bool _pending_monitorenter;
362
363 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
364 bool _pending_transfer_to_interpreter;
365
366 // An id of a speculation that JVMCI compiled code can use to further describe and
367 // uniquely identify the speculative optimization guarded by an uncommon trap.
368 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
369 jlong _pending_failed_speculation;
370
371 // These fields are mutually exclusive in terms of live ranges.
372 union {
373 // Communicates the pc at which the most recent implicit exception occurred
374 // from the signal handler to a deoptimization stub.
375 address _implicit_exception_pc;
376
377 // Communicates an alternative call target to an i2c stub from a JavaCall .
378 address _alternate_call_target;
379 } _jvmci;
380
381 // The JVMCIRuntime in a JVMCI shared library
382 JVMCIRuntime* _libjvmci_runtime;
383
384 // Support for high precision, thread sensitive counters in JVMCI compiled code.
385 jlong* _jvmci_counters;
386
387 // Fast thread locals for use by JVMCI
388 jlong _jvmci_reserved0;
389 jlong _jvmci_reserved1;
390 oop _jvmci_reserved_oop0;
391
392 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
393 // be kept alive
394 nmethod* _live_nmethod;
395
396 public:
397 static jlong* _jvmci_old_thread_counters;
398 static void collect_counters(jlong* array, int length);
399
400 bool resize_counters(int current_size, int new_size);
401
402 static bool resize_all_jvmci_counters(int new_size);
403
404 void set_jvmci_reserved_oop0(oop value) {
405 _jvmci_reserved_oop0 = value;
406 }
407
408 oop get_jvmci_reserved_oop0() {
409 return _jvmci_reserved_oop0;
410 }
411
412 void set_jvmci_reserved0(jlong value) {
413 _jvmci_reserved0 = value;
414 }
415
416 jlong get_jvmci_reserved0() {
417 return _jvmci_reserved0;
418 }
419
420 void set_jvmci_reserved1(jlong value) {
421 _jvmci_reserved1 = value;
422 }
423
424 jlong get_jvmci_reserved1() {
425 return _jvmci_reserved1;
426 }
427
428 void set_live_nmethod(nmethod* nm) {
429 assert(_live_nmethod == nullptr, "only one");
430 _live_nmethod = nm;
431 }
432
433 void clear_live_nmethod() {
434 _live_nmethod = nullptr;
435 }
436
437 private:
438 #endif // INCLUDE_JVMCI
439
440 StackOverflow _stack_overflow_state;
441
442 void pretouch_stack();
443
444 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
445 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
446 // code)
447 volatile oop _exception_oop; // Exception thrown in compiled code
448 volatile address _exception_pc; // PC where exception happened
449 volatile address _exception_handler_pc; // PC for handler of exception
450
451 private:
452 // support for JNI critical regions
453 jint _jni_active_critical; // count of entries into JNI critical region
454
455 // Checked JNI: function name requires exception check
456 char* _pending_jni_exception_check_fn;
457
458 // For deadlock detection.
459 int _depth_first_number;
460
461 // JVMTI PopFrame support
462 // This is set to popframe_pending to signal that top Java frame should be popped immediately
463 int _popframe_condition;
464
465 // If reallocation of scalar replaced objects fails, we throw OOM
466 // and during exception propagation, pop the top
467 // _frames_to_pop_failed_realloc frames, the ones that reference
468 // failed reallocations.
469 int _frames_to_pop_failed_realloc;
470
471 ContinuationEntry* _cont_entry;
472 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub/upcall_stub/native_wrapper
473 // frame inside the continuation that we know about
474 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
475
476 ObjectMonitor* _unlocked_inflated_monitor;
477
478 // This is the field we poke in the interpreter and native
479 // wrapper (Object.wait) to check for preemption.
480 address _preempt_alternate_return;
481 // When preempting on monitorenter we could have acquired the
482 // monitor after freezing all vthread frames. In that case we
483 // set this field so that in the preempt stub we call thaw again
484 // instead of unmounting.
485 bool _preemption_cancelled;
486 // For Object.wait() we set this field to know if we need to
487 // throw IE at the end of thawing before returning to Java.
488 bool _pending_interrupted_exception;
489 // We allow preemption on some klass initialization calls.
490 // We use this boolean to mark such calls.
491 bool _at_preemptable_init;
492
493 public:
494 bool preemption_cancelled() { return _preemption_cancelled; }
495 void set_preemption_cancelled(bool b) { _preemption_cancelled = b; }
496
497 bool pending_interrupted_exception() { return _pending_interrupted_exception; }
498 void set_pending_interrupted_exception(bool b) { _pending_interrupted_exception = b; }
499
500 bool preempting() { return _preempt_alternate_return != nullptr; }
501 void set_preempt_alternate_return(address val) { _preempt_alternate_return = val; }
502
503 bool at_preemptable_init() { return _at_preemptable_init; }
504 void set_at_preemptable_init(bool b) { _at_preemptable_init = b; }
505
506 #ifdef ASSERT
507 // Used for extra logging with -Xlog:continuation+preempt
508 InstanceKlass* _preempt_init_klass;
509
510 InstanceKlass* preempt_init_klass() { return _preempt_init_klass; }
511 void set_preempt_init_klass(InstanceKlass* ik) { _preempt_init_klass = ik; }
512
513 int _interp_at_preemptable_vmcall_cnt;
514 int interp_at_preemptable_vmcall_cnt() { return _interp_at_preemptable_vmcall_cnt; }
515
516 bool _interp_redoing_vm_call;
517 bool interp_redoing_vm_call() const { return _interp_redoing_vm_call; };
518
519 class AtRedoVMCall : public StackObj {
520 JavaThread* _thread;
521 public:
522 AtRedoVMCall(JavaThread* t) : _thread(t) {
523 assert(!_thread->_interp_redoing_vm_call, "");
524 _thread->_interp_redoing_vm_call = true;
525 _thread->_interp_at_preemptable_vmcall_cnt++;
526 assert(_thread->_interp_at_preemptable_vmcall_cnt > 0, "Unexpected count: %d",
527 _thread->_interp_at_preemptable_vmcall_cnt);
528 }
529 ~AtRedoVMCall() {
530 assert(_thread->_interp_redoing_vm_call, "");
531 _thread->_interp_redoing_vm_call = false;
532 _thread->_interp_at_preemptable_vmcall_cnt--;
533 assert(_thread->_interp_at_preemptable_vmcall_cnt >= 0, "Unexpected count: %d",
534 _thread->_interp_at_preemptable_vmcall_cnt);
535 }
536 };
537 #endif // ASSERT
538
539 private:
540 friend class VMThread;
541 friend class ThreadWaitTransition;
542 friend class VM_Exit;
543
544 // Stack watermark barriers.
545 StackWatermarks _stack_watermarks;
546
547 public:
548 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
549
550 public:
551 // Constructor
552 JavaThread(MemTag mem_tag = mtThread); // delegating constructor
553 JavaThread(ThreadFunction entry_point, size_t stack_size = 0, MemTag mem_tag = mtThread);
554 ~JavaThread();
555
556 // Factory method to create a new JavaThread whose attach state is "is attaching"
557 static JavaThread* create_attaching_thread();
558
559 #ifdef ASSERT
560 // verify this JavaThread hasn't be published in the Threads::list yet
561 void verify_not_published();
562 #endif // ASSERT
563
564 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
565
566 //JNI functiontable getter/setter for JVMTI jni function table interception API.
567 void set_jni_functions(struct JNINativeInterface_* functionTable) {
568 _jni_environment.functions = functionTable;
569 }
570 struct JNINativeInterface_* get_jni_functions() {
571 return (struct JNINativeInterface_ *)_jni_environment.functions;
572 }
573
574 // This function is called at thread creation to allow
575 // platform specific thread variables to be initialized.
576 void cache_global_variables();
577
578 // Executes Shutdown.shutdown()
579 void invoke_shutdown_hooks();
580
581 // Cleanup on thread exit
582 enum ExitType {
583 normal_exit,
584 jni_detach
585 };
586 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
587
588 void cleanup_failed_attach_current_thread(bool is_daemon);
589
590 // Testers
591 virtual bool is_Java_thread() const { return true; }
592 virtual bool can_call_java() const { return true; }
593
594 virtual bool is_active_Java_thread() const;
595
596 // Thread oop. threadObj() can be null for initial JavaThread
597 // (or for threads attached via JNI)
598 oop threadObj() const;
599 void set_threadOopHandles(oop p);
600 oop vthread() const;
601 void set_vthread(oop p);
602 oop scopedValueCache() const;
603 void set_scopedValueCache(oop p);
604 void clear_scopedValueBindings();
605 oop jvmti_vthread() const;
606 void set_jvmti_vthread(oop p);
607 oop vthread_or_thread() const;
608
609 // Prepare thread and add to priority queue. If a priority is
610 // not specified, use the priority of the thread object. Threads_lock
611 // must be held while this function is called.
612 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
613
614 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
615 address saved_exception_pc() { return _saved_exception_pc; }
616
617 ThreadFunction entry_point() const { return _entry_point; }
618
619 // Allocates a new Java level thread object for this thread. thread_name may be null.
620 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
621
622 // Last frame anchor routines
623
624 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
625
626 // last_Java_sp
627 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
628 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
629
630 // last_Java_pc
631
632 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
633
634 // Safepoint support
635 inline JavaThreadState thread_state() const;
636 inline void set_thread_state(JavaThreadState s);
637 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
638 inline ThreadSafepointState* safepoint_state() const;
639 inline void set_safepoint_state(ThreadSafepointState* state);
640 inline bool is_at_poll_safepoint();
641
642 // JavaThread termination and lifecycle support:
643 void smr_delete();
644 bool on_thread_list() const { return _on_thread_list; }
645 void set_on_thread_list() { _on_thread_list = true; }
646
647 // thread has called JavaThread::exit(), thread's GC barrier is detached
648 // or thread is terminated
649 bool is_exiting() const;
650 // thread's GC barrier is NOT detached and thread is NOT terminated
651 bool is_oop_safe() const;
652 // thread is terminated (no longer on the threads list); the thread must
653 // be protected by a ThreadsListHandle to avoid potential crashes.
654 bool check_is_terminated(TerminatedTypes l_terminated) const {
655 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
656 }
657 bool is_terminated() const;
658 void set_terminated(TerminatedTypes t);
659
660 void block_if_vm_exited();
661
662 bool doing_unsafe_access() { return _doing_unsafe_access; }
663 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
664
665 bool is_throwing_unsafe_access_error() { return _throwing_unsafe_access_error; }
666 void set_throwing_unsafe_access_error(bool val) { _throwing_unsafe_access_error = val; }
667
668 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
669 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
670
671 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
672
673 static ByteSize polling_word_offset() {
674 ByteSize offset = byte_offset_of(Thread, _poll_data) +
675 byte_offset_of(SafepointMechanism::ThreadData, _polling_word);
676 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
677 assert(in_bytes(offset) < 128, "Offset >= 128");
678 return offset;
679 }
680
681 static ByteSize polling_page_offset() {
682 ByteSize offset = byte_offset_of(Thread, _poll_data) +
683 byte_offset_of(SafepointMechanism::ThreadData, _polling_page);
684 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
685 assert(in_bytes(offset) < 128, "Offset >= 128");
686 return offset;
687 }
688
689 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
690
691 // Continuation support
692 ContinuationEntry* last_continuation() const { return _cont_entry; }
693 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
694 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
695 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
696 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
697 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
698 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
699
700 // Support for SharedRuntime::monitor_exit_helper()
701 ObjectMonitor* unlocked_inflated_monitor() const { return _unlocked_inflated_monitor; }
702 void clear_unlocked_inflated_monitor() {
703 _unlocked_inflated_monitor = nullptr;
704 }
705
706 inline bool is_vthread_mounted() const;
707 inline const ContinuationEntry* vthread_continuation() const;
708
709 private:
710 DEBUG_ONLY(void verify_frame_info();)
711
712 // Support for thread handshake operations
713 HandshakeState _handshake;
714 public:
715 HandshakeState* handshake_state() { return &_handshake; }
716
717 // A JavaThread can always safely operate on it self and other threads
718 // can do it safely if they are the active handshaker.
719 bool is_handshake_safe_for(Thread* th) const {
720 return _handshake.active_handshaker() == th || this == th;
721 }
722
723 // Suspend/resume support for JavaThread
724 // higher-level suspension/resume logic called by the public APIs
725 private:
726 SuspendResumeManager _suspend_resume_manager;
727 public:
728 bool java_suspend(bool register_vthread_SR);
729 bool java_resume(bool register_vthread_SR);
730 bool is_suspended() { return _suspend_resume_manager.is_suspended(); }
731 SuspendResumeManager* suspend_resume_manager() { return &_suspend_resume_manager; }
732
733 // Check for async exception in addition to safepoint.
734 static void check_special_condition_for_native_trans(JavaThread *thread);
735
736 // Synchronize with another thread that is deoptimizing objects of the
737 // current thread, i.e. reverts optimizations based on escape analysis.
738 void wait_for_object_deoptimization();
739
740 #if INCLUDE_JVMTI
741 inline bool set_carrier_thread_suspended();
742 inline bool clear_carrier_thread_suspended();
743
744 bool is_carrier_thread_suspended() const {
745 return AtomicAccess::load(&_carrier_thread_suspended);
746 }
747
748 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
749 void set_is_in_VTMS_transition(bool val);
750
751 bool is_disable_suspend() const { return _is_disable_suspend; }
752 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
753
754 bool is_in_java_upcall() const { return _is_in_java_upcall; }
755 void toggle_is_in_java_upcall() { _is_in_java_upcall = !_is_in_java_upcall; };
756
757 bool VTMS_transition_mark() const { return AtomicAccess::load(&_VTMS_transition_mark); }
758 void set_VTMS_transition_mark(bool val) { AtomicAccess::store(&_VTMS_transition_mark, val); }
759
760 // Temporarily skip posting JVMTI events for safety reasons when executions is in a critical section:
761 // - is in a VTMS transition (_is_in_VTMS_transition)
762 // - is in an interruptLock or similar critical section (_is_disable_suspend)
763 // - JVMTI is making a Java upcall (_is_in_java_upcall)
764 bool should_hide_jvmti_events() const { return _is_in_VTMS_transition || _is_disable_suspend || _is_in_java_upcall; }
765
766 bool on_monitor_waited_event() { return _on_monitor_waited_event; }
767 void set_on_monitor_waited_event(bool val) { _on_monitor_waited_event = val; }
768
769 bool pending_contended_entered_event() { return _contended_entered_monitor != nullptr; }
770 ObjectMonitor* contended_entered_monitor() { return _contended_entered_monitor; }
771 #ifdef ASSERT
772 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
773 void set_is_VTMS_transition_disabler(bool val);
774 #endif
775 #endif
776
777 void set_contended_entered_monitor(ObjectMonitor* val) NOT_JVMTI_RETURN JVMTI_ONLY({ _contended_entered_monitor = val; })
778
779 // Support for object deoptimization and JFR suspension
780 void handle_special_runtime_exit_condition();
781 bool has_special_runtime_exit_condition() {
782 return (_suspend_flags & _obj_deopt) != 0;
783 }
784
785 // Accessors for vframe array top
786 // The linked list of vframe arrays are sorted on sp. This means when we
787 // unpack the head must contain the vframe array to unpack.
788 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
789 vframeArray* vframe_array_head() const { return _vframe_array_head; }
790
791 // Side structure for deferring update of java frame locals until deopt occurs
792 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
793 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
794
795 // These only really exist to make debugging deopt problems simpler
796
797 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
798 vframeArray* vframe_array_last() const { return _vframe_array_last; }
799
800 // The special resourceMark used during deoptimization
801
802 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
803 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
804
805 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
806 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
807
808 Method* callee_target() const { return _callee_target; }
809 void set_callee_target (Method* x) { _callee_target = x; }
810
811 // Oop results of vm runtime calls
812 oop vm_result_oop() const { return _vm_result_oop; }
813 void set_vm_result_oop(oop x) { _vm_result_oop = x; }
814
815 void set_vm_result_metadata(Metadata* x) { _vm_result_metadata = x; }
816
817 oop return_buffered_value() const { return _return_buffered_value; }
818 void set_return_buffered_value(oop val) { _return_buffered_value = val; }
819
820 // Is thread in scope of an InternalOOMEMark?
821 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
822 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
823
824 #if INCLUDE_JVMCI
825 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
826 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
827 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
828 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
829 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
830 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
831 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
832
833 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
834 void set_libjvmci_runtime(JVMCIRuntime* rt) {
835 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
836 _libjvmci_runtime = rt;
837 }
838 #endif // INCLUDE_JVMCI
839
840 // Exception handling for compiled methods
841 oop exception_oop() const;
842 address exception_pc() const { return _exception_pc; }
843
844 void set_exception_oop(oop o);
845 void set_exception_pc(address a) { _exception_pc = a; }
846 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
847
848 void clear_exception_oop_and_pc() {
849 set_exception_oop(nullptr);
850 set_exception_pc(nullptr);
851 }
852
853 // Check if address is in the usable part of the stack (excludes protected
854 // guard pages). Can be applied to any thread and is an approximation for
855 // using is_in_live_stack when the query has to happen from another thread.
856 bool is_in_usable_stack(address adr) const {
857 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
858 }
859
860 // Misc. accessors/mutators
861 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
862
863 // For assembly stub generation
864 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
865 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
866 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
867 static ByteSize pending_jni_exception_check_fn_offset() {
868 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
869 }
870 static ByteSize last_Java_sp_offset() {
871 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
872 }
873 static ByteSize last_Java_pc_offset() {
874 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
875 }
876 static ByteSize frame_anchor_offset() {
877 return byte_offset_of(JavaThread, _anchor);
878 }
879 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
880 static ByteSize vm_result_oop_offset() { return byte_offset_of(JavaThread, _vm_result_oop); }
881 static ByteSize vm_result_metadata_offset() { return byte_offset_of(JavaThread, _vm_result_metadata); }
882 static ByteSize return_buffered_value_offset() { return byte_offset_of(JavaThread, _return_buffered_value); }
883 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
884 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
885 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
886 #if INCLUDE_JVMCI
887 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
888 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
889 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
890 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
891 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
892 #endif // INCLUDE_JVMCI
893 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
894 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
895 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
896
897 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
898
899 // StackOverflow offsets
900 static ByteSize stack_overflow_limit_offset() {
901 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
902 }
903 static ByteSize stack_guard_state_offset() {
904 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
905 }
906 static ByteSize reserved_stack_activation_offset() {
907 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
908 }
909 static ByteSize shadow_zone_safe_limit() {
910 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
911 }
912 static ByteSize shadow_zone_growth_watermark() {
913 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
914 }
915
916 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
917
918 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
919 static ByteSize should_post_on_exceptions_flag_offset() {
920 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
921 }
922 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
923 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
924
925 static ByteSize monitor_owner_id_offset() { return byte_offset_of(JavaThread, _monitor_owner_id); }
926
927 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
928 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
929 static ByteSize preemption_cancelled_offset() { return byte_offset_of(JavaThread, _preemption_cancelled); }
930 static ByteSize preempt_alternate_return_offset() { return byte_offset_of(JavaThread, _preempt_alternate_return); }
931 DEBUG_ONLY(static ByteSize interp_at_preemptable_vmcall_cnt_offset() { return byte_offset_of(JavaThread, _interp_at_preemptable_vmcall_cnt); })
932 static ByteSize unlocked_inflated_monitor_offset() { return byte_offset_of(JavaThread, _unlocked_inflated_monitor); }
933
934 #if INCLUDE_JVMTI
935 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); }
936 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
937 #endif
938
939 // Returns the jni environment for this thread
940 JNIEnv* jni_environment() { return &_jni_environment; }
941
942 // Returns the current thread as indicated by the given JNIEnv.
943 // We don't assert it is Thread::current here as that is done at the
944 // external JNI entry points where the JNIEnv is passed into the VM.
945 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
946 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
947 // We can't normally get here in a thread that has completed its
948 // execution and so "is_terminated", except when the call is from
949 // AsyncGetCallTrace, which can be triggered by a signal at any point in
950 // a thread's lifecycle. A thread is also considered terminated if the VM
951 // has exited, so we have to check this and block in case this is a daemon
952 // thread returning to the VM (the JNI DirectBuffer entry points rely on
953 // this).
954 if (current->is_terminated()) {
955 current->block_if_vm_exited();
956 }
957 return current;
958 }
959
960 // JNI critical regions. These can nest.
961 bool in_critical() { return _jni_active_critical > 0; }
962 bool in_last_critical() { return _jni_active_critical == 1; }
963 inline void enter_critical();
964 void exit_critical() {
965 assert(Thread::current() == this, "this must be current thread");
966 _jni_active_critical--;
967 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
968 }
969
970 // Atomic version; invoked by a thread other than the owning thread.
971 bool in_critical_atomic() { return AtomicAccess::load(&_jni_active_critical) > 0; }
972
973 // Checked JNI: is the programmer required to check for exceptions, if so specify
974 // which function name. Returning to a Java frame should implicitly clear the
975 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
976 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
977 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
978 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
979 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
980 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
981 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
982
983 // For deadlock detection
984 int depth_first_number() { return _depth_first_number; }
985 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
986
987 public:
988 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
989 void inc_in_deopt_handler() { _in_deopt_handler++; }
990 void dec_in_deopt_handler() {
991 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
992 if (_in_deopt_handler > 0) { // robustness
993 _in_deopt_handler--;
994 }
995 }
996
997 private:
998 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
999
1000 // factor out low-level mechanics for use in both normal and error cases
1001 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
1002
1003 public:
1004
1005 // Frame iteration; calls the function f for all frames on the stack
1006 void frames_do(void f(frame*, const RegisterMap*));
1007
1008 // Memory operations
1009 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
1010 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
1011
1012 // GC operations
1013 virtual void nmethods_do(NMethodClosure* cf);
1014
1015 // RedefineClasses Support
1016 void metadata_do(MetadataClosure* f);
1017
1018 // Debug method asserting thread states are correct during a handshake operation.
1019 DEBUG_ONLY(void verify_states_for_handshake();)
1020
1021 // Misc. operations
1022 const char* name() const;
1023 const char* name_raw() const;
1024 const char* type_name() const { return "JavaThread"; }
1025 static const char* name_for(oop thread_obj);
1026
1027 void print_on(outputStream* st, bool print_extended_info) const;
1028 void print_on(outputStream* st) const { print_on(st, false); }
1029 void print() const;
1030 void print_thread_state_on(outputStream*) const;
1031 void print_on_error(outputStream* st, char* buf, int buflen) const;
1032 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1033 void verify();
1034
1035 // Accessing frames
1036 frame last_frame() {
1037 _anchor.make_walkable();
1038 return pd_last_frame();
1039 }
1040 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
1041
1042 frame carrier_last_frame(RegisterMap* reg_map);
1043 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
1044
1045 frame vthread_last_frame();
1046 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
1047
1048 frame platform_thread_last_frame(RegisterMap* reg_map);
1049 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
1050 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
1051 }
1052
1053 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
1054
1055 // Returns method at 'depth' java or native frames down the stack
1056 // Used for security checks
1057 Klass* security_get_caller_class(int depth);
1058
1059 // Print stack trace in external format
1060 // These variants print carrier/platform thread information only.
1061 void print_stack_on(outputStream* st);
1062 void print_stack() { print_stack_on(tty); }
1063 // This prints the currently mounted virtual thread.
1064 void print_vthread_stack_on(outputStream* st);
1065 // This prints the active stack: either carrier/platform or virtual.
1066 void print_active_stack_on(outputStream* st);
1067 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1068 // This is the external format from above, but selecting the platform
1069 // or vthread as applicable.
1070 void print_jni_stack();
1071
1072 // Print stack traces in various internal formats
1073 void trace_stack() PRODUCT_RETURN;
1074 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1075 void trace_frames() PRODUCT_RETURN;
1076
1077 // Print an annotated view of the stack frames
1078 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1079 void validate_frame_layout() {
1080 print_frame_layout(0, true);
1081 }
1082
1083 // Function for testing deoptimization
1084 void deoptimize();
1085 void make_zombies();
1086
1087 void deoptimize_marked_methods();
1088
1089 public:
1090 // Returns the running thread as a JavaThread
1091 static JavaThread* current() {
1092 return JavaThread::cast(Thread::current());
1093 }
1094
1095 // Returns the current thread as a JavaThread, or nullptr if not attached
1096 static inline JavaThread* current_or_null();
1097
1098 // Casts
1099 static JavaThread* cast(Thread* t) {
1100 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
1101 return static_cast<JavaThread*>(t);
1102 }
1103
1104 static const JavaThread* cast(const Thread* t) {
1105 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1106 return static_cast<const JavaThread*>(t);
1107 }
1108
1109 // Returns the active Java thread. Do not use this if you know you are calling
1110 // from a JavaThread, as it's slower than JavaThread::current. If called from
1111 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1112 // operation. You may not want that either.
1113 static JavaThread* active();
1114
1115 protected:
1116 virtual void pre_run();
1117 virtual void run();
1118 void thread_main_inner();
1119 virtual void post_run();
1120
1121 public:
1122 // Thread local information maintained by JVMTI.
1123 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1124 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1125 // getter is used to get this JavaThread's JvmtiThreadState if it has
1126 // one which means null can be returned. JvmtiThreadState::state_for()
1127 // is used to get the specified JavaThread's JvmtiThreadState if it has
1128 // one or it allocates a new JvmtiThreadState for the JavaThread and
1129 // returns it. JvmtiThreadState::state_for() will return null only if
1130 // the specified JavaThread is exiting.
1131 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1132 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1133
1134 #if INCLUDE_JVMTI
1135 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1136 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1137 #endif
1138
1139 // JVMTI PopFrame support
1140 // Setting and clearing popframe_condition
1141 // All of these enumerated values are bits. popframe_pending
1142 // indicates that a PopFrame() has been requested and not yet been
1143 // completed. popframe_processing indicates that that PopFrame() is in
1144 // the process of being completed. popframe_force_deopt_reexecution_bit
1145 // indicates that special handling is required when returning to a
1146 // deoptimized caller.
1147 enum PopCondition {
1148 popframe_inactive = 0x00,
1149 popframe_pending_bit = 0x01,
1150 popframe_processing_bit = 0x02,
1151 popframe_force_deopt_reexecution_bit = 0x04
1152 };
1153 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1154 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1155 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1156 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1157 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1158 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1159 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1160
1161 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1162 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1163 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1164
1165 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1166 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1167 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1168
1169 private:
1170 // Saved incoming arguments to popped frame.
1171 // Used only when popped interpreted frame returns to deoptimized frame.
1172 void* _popframe_preserved_args;
1173 int _popframe_preserved_args_size;
1174
1175 public:
1176 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1177 void* popframe_preserved_args();
1178 ByteSize popframe_preserved_args_size();
1179 WordSize popframe_preserved_args_size_in_words();
1180 void popframe_free_preserved_args();
1181
1182
1183 private:
1184 JvmtiThreadState *_jvmti_thread_state;
1185
1186 // Used by the interpreter in fullspeed mode for frame pop, method
1187 // entry, method exit and single stepping support. This field is
1188 // only set to non-zero at a safepoint or using a direct handshake
1189 // (see EnterInterpOnlyModeHandshakeClosure).
1190 // It can be set to zero asynchronously to this threads execution (i.e., without
1191 // safepoint/handshake or a lock) so we have to be very careful.
1192 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1193 // This field is checked by the interpreter which expects it to be an integer.
1194 int _interp_only_mode;
1195
1196 public:
1197 // used by the interpreter for fullspeed debugging support (see above)
1198 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1199 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1200 void set_interp_only_mode(bool val) { _interp_only_mode = val ? 1 : 0; }
1201
1202 // support for cached flag that indicates whether exceptions need to be posted for this thread
1203 // if this is false, we can avoid deoptimizing when events are thrown
1204 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1205 private:
1206 int _should_post_on_exceptions_flag;
1207
1208 public:
1209 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1210
1211 private:
1212 ThreadStatistics *_thread_stat;
1213
1214 public:
1215 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1216
1217 // Return a blocker object for which this thread is blocked parking.
1218 oop current_park_blocker();
1219
1220 private:
1221 static size_t _stack_size_at_create;
1222
1223 public:
1224 static inline size_t stack_size_at_create(void) {
1225 return _stack_size_at_create;
1226 }
1227 static inline void set_stack_size_at_create(size_t value) {
1228 _stack_size_at_create = value;
1229 }
1230
1231 // Machine dependent stuff
1232 #include OS_CPU_HEADER(javaThread)
1233
1234 // JSR166 per-thread parker
1235 private:
1236 Parker _parker;
1237 public:
1238 Parker* parker() { return &_parker; }
1239
1240 public:
1241 // clearing/querying jni attach status
1242 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1243 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1244 inline void set_done_attaching_via_jni();
1245
1246 // Stack dump assistance:
1247 // Track the class we want to initialize but for which we have to wait
1248 // on its init_lock() because it is already being initialized.
1249 void set_class_to_be_initialized(InstanceKlass* k);
1250 InstanceKlass* class_to_be_initialized() const;
1251
1252 // Track executing class initializer, see ThreadInClassInitializer
1253 void set_class_being_initialized(InstanceKlass* k);
1254 InstanceKlass* class_being_initialized() const;
1255
1256 private:
1257 InstanceKlass* _class_to_be_initialized;
1258 InstanceKlass* _class_being_initialized;
1259
1260 // java.lang.Thread.sleep support
1261 ParkEvent * _SleepEvent;
1262
1263 #if INCLUDE_JFR
1264 // Support for jdk.VirtualThreadPinned event
1265 freeze_result _last_freeze_fail_result;
1266 Ticks _last_freeze_fail_time;
1267 #endif
1268
1269 public:
1270 bool sleep(jlong millis);
1271 bool sleep_nanos(jlong nanos);
1272
1273 // java.lang.Thread interruption support
1274 void interrupt();
1275 bool is_interrupted(bool clear_interrupted);
1276
1277 #if INCLUDE_JFR
1278 // Support for jdk.VirtualThreadPinned event
1279 freeze_result last_freeze_fail_result() { return _last_freeze_fail_result; }
1280 Ticks& last_freeze_fail_time() { return _last_freeze_fail_time; }
1281 void set_last_freeze_fail_result(freeze_result result);
1282 #endif
1283 void post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) NOT_JFR_RETURN();
1284
1285
1286 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1287 // the Java code in Object::wait which are not present in RawMonitorWait.
1288 bool get_and_clear_interrupted();
1289
1290 private:
1291 LockStack _lock_stack;
1292 OMCache _om_cache;
1293
1294 public:
1295 LockStack& lock_stack() { return _lock_stack; }
1296
1297 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1298 // Those offsets are used in code generators to access the LockStack that is embedded in this
1299 // JavaThread structure. Those accesses are relative to the current thread, which
1300 // is typically in a dedicated register.
1301 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1302 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1303
1304 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); }
1305 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); }
1306
1307 void om_set_monitor_cache(ObjectMonitor* monitor);
1308 void om_clear_monitor_cache();
1309 ObjectMonitor* om_get_from_monitor_cache(oop obj);
1310
1311 static OopStorage* thread_oop_storage();
1312
1313 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1314
1315 // Helper function to create the java.lang.Thread object for a
1316 // VM-internal thread. The thread will have the given name and be
1317 // part of the System ThreadGroup.
1318 static Handle create_system_thread_object(const char* name, TRAPS);
1319
1320 // Helper function to start a VM-internal daemon thread.
1321 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1322 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1323 Handle thread_oop, ThreadPriority prio);
1324
1325 // Helper function to do vm_exit_on_initialization for osthread
1326 // resource allocation failure.
1327 static void vm_exit_on_osthread_failure(JavaThread* thread);
1328
1329 // Deferred OopHandle release support
1330 private:
1331 // List of OopHandles to be released - guarded by the Service_lock.
1332 static OopHandleList* _oop_handle_list;
1333 // Add our OopHandles to the list for the service thread to release.
1334 void add_oop_handles_for_release();
1335 // Called by the ServiceThread to release the OopHandles.
1336 static void release_oop_handles();
1337 // Called by the ServiceThread to poll if there are any OopHandles to release.
1338 // Called when holding the Service_lock.
1339 static bool has_oop_handles_to_release() {
1340 return _oop_handle_list != nullptr;
1341 }
1342 };
1343
1344 inline JavaThread* JavaThread::current_or_null() {
1345 Thread* current = Thread::current_or_null();
1346 return current != nullptr ? JavaThread::cast(current) : nullptr;
1347 }
1348
1349 class UnlockFlagSaver {
1350 private:
1351 JavaThread* _thread;
1352 bool _do_not_unlock;
1353 public:
1354 UnlockFlagSaver(JavaThread* t) {
1355 _thread = t;
1356 _do_not_unlock = t->do_not_unlock_if_synchronized();
1357 t->set_do_not_unlock_if_synchronized(false);
1358 }
1359 ~UnlockFlagSaver() {
1360 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1361 }
1362 };
1363
1364 class JNIHandleMark : public StackObj {
1365 JavaThread* _thread;
1366 public:
1367 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1368 thread->push_jni_handle_block();
1369 }
1370 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1371 };
1372
1373 class NoPreemptMark {
1374 ContinuationEntry* _ce;
1375 bool _unpin;
1376 public:
1377 NoPreemptMark(JavaThread* thread, bool ignore_mark = false) : _ce(thread->last_continuation()), _unpin(false) {
1378 if (_ce != nullptr && !ignore_mark) _unpin = _ce->pin();
1379 }
1380 ~NoPreemptMark() { if (_unpin) _ce->unpin(); }
1381 };
1382
1383 class ThreadOnMonitorWaitedEvent {
1384 JavaThread* _thread;
1385 public:
1386 ThreadOnMonitorWaitedEvent(JavaThread* thread) : _thread(thread) {
1387 JVMTI_ONLY(_thread->set_on_monitor_waited_event(true);)
1388 }
1389 ~ThreadOnMonitorWaitedEvent() { JVMTI_ONLY(_thread->set_on_monitor_waited_event(false);) }
1390 };
1391
1392 class ThreadInClassInitializer : public StackObj {
1393 JavaThread* _thread;
1394 InstanceKlass* _previous;
1395 public:
1396 ThreadInClassInitializer(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
1397 _previous = _thread->class_being_initialized();
1398 _thread->set_class_being_initialized(ik);
1399 }
1400 ~ThreadInClassInitializer() {
1401 _thread->set_class_being_initialized(_previous);
1402 }
1403 };
1404
1405 class ThrowingUnsafeAccessError : public StackObj {
1406 JavaThread* _thread;
1407 bool _prev;
1408 public:
1409 ThrowingUnsafeAccessError(JavaThread* thread) :
1410 _thread(thread),
1411 _prev(thread->is_throwing_unsafe_access_error()) {
1412 _thread->set_throwing_unsafe_access_error(true);
1413 }
1414 ~ThrowingUnsafeAccessError() {
1415 _thread->set_throwing_unsafe_access_error(_prev);
1416 }
1417 };
1418
1419 #endif // SHARE_RUNTIME_JAVATHREAD_HPP