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