1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #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/stackWatermarkSet.hpp"
42 #include "runtime/stackOverflow.hpp"
43 #include "runtime/thread.hpp"
44 #include "runtime/threadHeapSampler.hpp"
45 #include "runtime/threadIdentifier.hpp"
46 #include "runtime/threadStatisticalInfo.hpp"
47 #include "utilities/exceptions.hpp"
48 #include "utilities/globalDefinitions.hpp"
49 #include "utilities/macros.hpp"
50 #if INCLUDE_JFR
51 #include "jfr/support/jfrThreadExtension.hpp"
52 #include "utilities/ticks.hpp"
53 #endif
54
55 class AsyncExceptionHandshake;
56 class DeoptResourceMark;
57 class InternalOOMEMark;
58 class JNIHandleBlock;
59 class JVMCIRuntime;
60
61 class JvmtiDeferredUpdates;
62 class JvmtiSampledObjectAllocEventCollector;
63 class JvmtiThreadState;
64
65 class Metadata;
66 class ObjectMonitor;
67 class OopHandleList;
68 class OopStorage;
69 class OSThread;
70
71 class ThreadsList;
72 class ThreadSafepointState;
73 class ThreadStatistics;
74
75 class vframeArray;
76 class vframe;
77 class javaVFrame;
78
79 class JavaThread;
80 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
81
82 class EventVirtualThreadPinned;
83
84 class JavaThread: public Thread {
85 friend class VMStructs;
86 friend class JVMCIVMStructs;
87 friend class WhiteBox;
88 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
89 friend class HandshakeState;
90 friend class Continuation;
91 friend class Threads;
92 friend class ServiceThread; // for deferred OopHandle release access
93 private:
94 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
95
96 // All references to Java objects managed via OopHandles. These
97 // have to be released by the ServiceThread after the JavaThread has
98 // terminated - see add_oop_handles_for_release().
99 OopHandle _threadObj; // The Java level thread object
100 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj
101 OopHandle _jvmti_vthread;
102 OopHandle _scopedValueCache;
103
104 static OopStorage* _thread_oop_storage;
105
106 #ifdef ASSERT
107 private:
108 int _java_call_counter;
109
110 public:
111 int java_call_counter() { return _java_call_counter; }
112 void inc_java_call_counter() { _java_call_counter++; }
113 void dec_java_call_counter() {
114 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
115 _java_call_counter--;
116 }
117 private: // restore original namespace restriction
118 #endif // ifdef ASSERT
119
120 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
121
122 ThreadFunction _entry_point;
123
124 JNIEnv _jni_environment;
125
126 // Deopt support
127 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
128
129 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
130 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
131 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
132 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
133 // will be carried out as soon as possible which, in most cases, is just before deoptimization of
134 // the frame, when control returns to it.
135 JvmtiDeferredUpdates* _jvmti_deferred_updates;
136
137 // Handshake value for fixing 6243940. We need a place for the i2c
138 // adapter to store the callee Method*. This value is NEVER live
139 // across a gc point so it does NOT have to be gc'd
140 // The handshake is open ended since we can't be certain that it will
141 // be nulled. This is because we rarely ever see the race and end up
142 // in handle_wrong_method which is the backend of the handshake. See
143 // code in i2c adapters and handle_wrong_method.
144
145 Method* _callee_target;
146
147 // Used to pass back results to the interpreter or generated code running Java code.
148 oop _vm_result_oop; // oop result is GC-preserved
149 Metadata* _vm_result_metadata; // non-oop result
150 oop _return_buffered_value; // buffered value being returned
151
152 // See ReduceInitialCardMarks: this holds the precise space interval of
153 // the most recent slow path allocation for which compiled code has
154 // elided card-marks for performance along the fast-path.
155 MemRegion _deferred_card_mark;
156
157 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
158 bool _current_pending_monitor_is_from_java; // locking is from Java code
159 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
160
161 // Active_handles points to a block of handles
162 JNIHandleBlock* _active_handles;
163
164 // One-element thread local free list
165 JNIHandleBlock* _free_handle_block;
166
167 // ID used as owner for inflated monitors. Same as the j.l.Thread.tid of the
168 // current _vthread object, except during creation of the primordial and JNI
169 // attached thread cases where this field can have a temporary value.
170 int64_t _monitor_owner_id;
171
172 public:
173 void set_monitor_owner_id(int64_t id) {
174 ThreadIdentifier::verify_id(id);
175 _monitor_owner_id = id;
176 }
177 int64_t monitor_owner_id() const {
178 int64_t id = _monitor_owner_id;
179 ThreadIdentifier::verify_id(id);
180 return id;
181 }
182
183 // For tracking the heavyweight monitor the thread is pending on.
184 ObjectMonitor* current_pending_monitor() {
185 // Use Atomic::load() to prevent data race between concurrent modification and
186 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
187 // Especially, reloading pointer from thread after null check must be prevented.
188 return Atomic::load(&_current_pending_monitor);
189 }
190 void set_current_pending_monitor(ObjectMonitor* monitor) {
191 Atomic::store(&_current_pending_monitor, monitor);
192 }
193 void set_current_pending_monitor_is_from_java(bool from_java) {
194 _current_pending_monitor_is_from_java = from_java;
195 }
196 bool current_pending_monitor_is_from_java() {
197 return _current_pending_monitor_is_from_java;
198 }
199 ObjectMonitor* current_waiting_monitor() {
200 // See the comment in current_pending_monitor() above.
201 return Atomic::load(&_current_waiting_monitor);
202 }
203 void set_current_waiting_monitor(ObjectMonitor* monitor) {
204 Atomic::store(&_current_waiting_monitor, monitor);
205 }
206
207 // JNI handle support
208 JNIHandleBlock* active_handles() const { return _active_handles; }
209 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
210 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
211 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
212
213 void push_jni_handle_block();
214 void pop_jni_handle_block();
215
216 private:
217 enum SuspendFlags {
218 // NOTE: avoid using the sign-bit as cc generates different test code
219 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
220 _trace_flag = 0x00000004U, // call tracing backend
221 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
222 };
223
224 // various suspension related flags - atomically updated
225 volatile uint32_t _suspend_flags;
226
227 inline void set_suspend_flag(SuspendFlags f);
228 inline void clear_suspend_flag(SuspendFlags f);
229
230 public:
231 inline void set_trace_flag();
232 inline void clear_trace_flag();
233 inline void set_obj_deopt_flag();
234 inline void clear_obj_deopt_flag();
235 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
236 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
237
238 // Asynchronous exception support
239 private:
240 friend class InstallAsyncExceptionHandshake;
241 friend class AsyncExceptionHandshake;
242 friend class HandshakeState;
243
244 void handle_async_exception(oop java_throwable);
245 public:
246 void install_async_exception(AsyncExceptionHandshake* aec = nullptr);
247 bool has_async_exception_condition();
248 inline void set_pending_unsafe_access_error();
249 static void send_async_exception(JavaThread* jt, oop java_throwable);
250
251 class NoAsyncExceptionDeliveryMark : public StackObj {
252 friend JavaThread;
253 JavaThread *_target;
254 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
255 inline ~NoAsyncExceptionDeliveryMark();
256 };
257
258 // Safepoint support
259 public: // Expose _thread_state for SafeFetchInt()
260 volatile JavaThreadState _thread_state;
261 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
262 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
263 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
264 #ifdef ASSERT
265 // Debug support for checking if code allows safepoints or not.
266 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
267 // mutex, or blocking on an object synchronizer (Java locking).
268 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
269 // the above cases. The class NoSafepointVerifier is used to set this counter.
270 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
271
272 public:
273 void inc_no_safepoint_count() { _no_safepoint_count++; }
274 void dec_no_safepoint_count() { _no_safepoint_count--; }
275 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
276 #endif // ASSERT
277 public:
278 // These functions check conditions before possibly going to a safepoint.
279 // including NoSafepointVerifier.
280 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
281 void check_possible_safepoint() NOT_DEBUG_RETURN;
282
283 #ifdef ASSERT
284 private:
285 volatile uint64_t _visited_for_critical_count;
286
287 public:
288 void set_visited_for_critical_count(uint64_t safepoint_id) {
289 assert(_visited_for_critical_count == 0, "Must be reset before set");
290 assert((safepoint_id & 0x1) == 1, "Must be odd");
291 _visited_for_critical_count = safepoint_id;
292 }
293 void reset_visited_for_critical_count(uint64_t safepoint_id) {
294 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
295 _visited_for_critical_count = 0;
296 }
297 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
298 return _visited_for_critical_count == safepoint_id;
299 }
300 #endif // ASSERT
301
302 // JavaThread termination support
303 public:
304 enum TerminatedTypes {
305 _not_terminated = 0xDEAD - 3,
306 _thread_exiting, // JavaThread::exit() has been called for this thread
307 _thread_gc_barrier_detached, // thread's GC barrier has been detached
308 _thread_terminated, // JavaThread is removed from thread list
309 _vm_exited // JavaThread is still executing native code, but VM is terminated
310 // only VM_Exit can set _vm_exited
311 };
312
313 private:
314 // In general a JavaThread's _terminated field transitions as follows:
315 //
316 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
317 //
318 // _vm_exited is a special value to cover the case of a JavaThread
319 // executing native code after the VM itself is terminated.
320 //
321 // A JavaThread that fails to JNI attach has these _terminated field transitions:
322 // _not_terminated => _thread_terminated
323 //
324 volatile TerminatedTypes _terminated;
325
326 jint _in_deopt_handler; // count of deoptimization
327 // handlers thread is in
328 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
329 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
330 // never locked) when throwing an exception. Used by interpreter only.
331 #if INCLUDE_JVMTI
332 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
333 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
334 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
335 bool _is_in_java_upcall; // JVMTI is doing a Java upcall, so JVMTI events must be hidden
336 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers
337 bool _on_monitor_waited_event; // Avoid callee arg processing for enterSpecial when posting waited event
338 ObjectMonitor* _contended_entered_monitor; // Monitor for pending monitor_contended_entered callback
339 #ifdef ASSERT
340 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
341 #endif
342 #endif
343
344 // JNI attach states:
345 enum JNIAttachStates {
346 _not_attaching_via_jni = 1, // thread is not attaching via JNI
347 _attaching_via_jni, // thread is attaching via JNI
348 _attached_via_jni // thread has attached via JNI
349 };
350
351 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
352 // A native thread that is attaching via JNI starts with a value
353 // of _attaching_via_jni and transitions to _attached_via_jni.
354 volatile JNIAttachStates _jni_attach_state;
355
356 // In scope of an InternalOOMEMark?
357 bool _is_in_internal_oome_mark;
358
359 #if INCLUDE_JVMCI
360 // The _pending_* fields below are used to communicate extra information
361 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
362
363 // Communicates the DeoptReason and DeoptAction of the uncommon trap
364 int _pending_deoptimization;
365
366 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
367 // before the monitor has been acquired.
368 bool _pending_monitorenter;
369
370 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
371 bool _pending_transfer_to_interpreter;
372
373 // An id of a speculation that JVMCI compiled code can use to further describe and
374 // uniquely identify the speculative optimization guarded by an uncommon trap.
375 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
376 jlong _pending_failed_speculation;
377
378 // These fields are mutually exclusive in terms of live ranges.
379 union {
380 // Communicates the pc at which the most recent implicit exception occurred
381 // from the signal handler to a deoptimization stub.
382 address _implicit_exception_pc;
383
384 // Communicates an alternative call target to an i2c stub from a JavaCall .
385 address _alternate_call_target;
386 } _jvmci;
387
388 // The JVMCIRuntime in a JVMCI shared library
389 JVMCIRuntime* _libjvmci_runtime;
390
391 // Support for high precision, thread sensitive counters in JVMCI compiled code.
392 jlong* _jvmci_counters;
393
394 // Fast thread locals for use by JVMCI
395 jlong _jvmci_reserved0;
396 jlong _jvmci_reserved1;
397 oop _jvmci_reserved_oop0;
398
399 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
400 // be kept alive
401 nmethod* _live_nmethod;
402
403 public:
404 static jlong* _jvmci_old_thread_counters;
405 static void collect_counters(jlong* array, int length);
406
407 bool resize_counters(int current_size, int new_size);
408
409 static bool resize_all_jvmci_counters(int new_size);
410
411 void set_jvmci_reserved_oop0(oop value) {
412 _jvmci_reserved_oop0 = value;
413 }
414
415 oop get_jvmci_reserved_oop0() {
416 return _jvmci_reserved_oop0;
417 }
418
419 void set_jvmci_reserved0(jlong value) {
420 _jvmci_reserved0 = value;
421 }
422
423 jlong get_jvmci_reserved0() {
424 return _jvmci_reserved0;
425 }
426
427 void set_jvmci_reserved1(jlong value) {
428 _jvmci_reserved1 = value;
429 }
430
431 jlong get_jvmci_reserved1() {
432 return _jvmci_reserved1;
433 }
434
435 void set_live_nmethod(nmethod* nm) {
436 assert(_live_nmethod == nullptr, "only one");
437 _live_nmethod = nm;
438 }
439
440 void clear_live_nmethod() {
441 _live_nmethod = nullptr;
442 }
443
444 private:
445 #endif // INCLUDE_JVMCI
446
447 StackOverflow _stack_overflow_state;
448
449 void pretouch_stack();
450
451 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
452 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
453 // code)
454 volatile oop _exception_oop; // Exception thrown in compiled code
455 volatile address _exception_pc; // PC where exception happened
456 volatile address _exception_handler_pc; // PC for handler of exception
457 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
458
459 private:
460 // support for JNI critical regions
461 jint _jni_active_critical; // count of entries into JNI critical region
462
463 // Checked JNI: function name requires exception check
464 char* _pending_jni_exception_check_fn;
465
466 // For deadlock detection.
467 int _depth_first_number;
468
469 // JVMTI PopFrame support
470 // This is set to popframe_pending to signal that top Java frame should be popped immediately
471 int _popframe_condition;
472
473 // If reallocation of scalar replaced objects fails, we throw OOM
474 // and during exception propagation, pop the top
475 // _frames_to_pop_failed_realloc frames, the ones that reference
476 // failed reallocations.
477 int _frames_to_pop_failed_realloc;
478
479 ContinuationEntry* _cont_entry;
480 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub/upcall_stub/native_wrapper
481 // frame inside the continuation that we know about
482 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
483
484 // It's signed for error detection.
485 intx _held_monitor_count; // used by continuations for fast lock detection
486 intx _jni_monitor_count;
487 ObjectMonitor* _unlocked_inflated_monitor;
488
489 // This is the field we poke in the interpreter and native
490 // wrapper (Object.wait) to check for preemption.
491 address _preempt_alternate_return;
492 // When preempting on monitorenter we could have acquired the
493 // monitor after freezing all vthread frames. In that case we
494 // set this field so that in the preempt stub we call thaw again
495 // instead of unmounting.
496 bool _preemption_cancelled;
497 // For Object.wait() we set this field to know if we need to
498 // throw IE at the end of thawing before returning to Java.
499 bool _pending_interrupted_exception;
500
501 public:
502 bool preemption_cancelled() { return _preemption_cancelled; }
503 void set_preemption_cancelled(bool b) { _preemption_cancelled = b; }
504
505 bool pending_interrupted_exception() { return _pending_interrupted_exception; }
506 void set_pending_interrupted_exception(bool b) { _pending_interrupted_exception = b; }
507
508 bool preempting() { return _preempt_alternate_return != nullptr; }
509 void set_preempt_alternate_return(address val) { _preempt_alternate_return = val; }
510
511 private:
512
513 friend class VMThread;
514 friend class ThreadWaitTransition;
515 friend class VM_Exit;
516
517 // Stack watermark barriers.
518 StackWatermarks _stack_watermarks;
519
520 public:
521 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
522
523 public:
524 // Constructor
525 JavaThread(MemTag mem_tag = mtThread); // delegating constructor
526 JavaThread(ThreadFunction entry_point, size_t stack_size = 0, MemTag mem_tag = mtThread);
527 ~JavaThread();
528
529 // Factory method to create a new JavaThread whose attach state is "is attaching"
530 static JavaThread* create_attaching_thread();
531
532 #ifdef ASSERT
533 // verify this JavaThread hasn't be published in the Threads::list yet
534 void verify_not_published();
535 #endif // ASSERT
536
537 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
538
539 //JNI functiontable getter/setter for JVMTI jni function table interception API.
540 void set_jni_functions(struct JNINativeInterface_* functionTable) {
541 _jni_environment.functions = functionTable;
542 }
543 struct JNINativeInterface_* get_jni_functions() {
544 return (struct JNINativeInterface_ *)_jni_environment.functions;
545 }
546
547 // This function is called at thread creation to allow
548 // platform specific thread variables to be initialized.
549 void cache_global_variables();
550
551 // Executes Shutdown.shutdown()
552 void invoke_shutdown_hooks();
553
554 // Cleanup on thread exit
555 enum ExitType {
556 normal_exit,
557 jni_detach
558 };
559 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
560
561 void cleanup_failed_attach_current_thread(bool is_daemon);
562
563 // Testers
564 virtual bool is_Java_thread() const { return true; }
565 virtual bool can_call_java() const { return true; }
566
567 virtual bool is_active_Java_thread() const;
568
569 // Thread oop. threadObj() can be null for initial JavaThread
570 // (or for threads attached via JNI)
571 oop threadObj() const;
572 void set_threadOopHandles(oop p);
573 oop vthread() const;
574 void set_vthread(oop p);
575 oop scopedValueCache() const;
576 void set_scopedValueCache(oop p);
577 void clear_scopedValueBindings();
578 oop jvmti_vthread() const;
579 void set_jvmti_vthread(oop p);
580 oop vthread_or_thread() const;
581
582 // Prepare thread and add to priority queue. If a priority is
583 // not specified, use the priority of the thread object. Threads_lock
584 // must be held while this function is called.
585 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
586
587 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
588 address saved_exception_pc() { return _saved_exception_pc; }
589
590 ThreadFunction entry_point() const { return _entry_point; }
591
592 // Allocates a new Java level thread object for this thread. thread_name may be null.
593 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
594
595 // Last frame anchor routines
596
597 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
598
599 // last_Java_sp
600 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
601 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
602
603 // last_Java_pc
604
605 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
606
607 // Safepoint support
608 inline JavaThreadState thread_state() const;
609 inline void set_thread_state(JavaThreadState s);
610 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
611 inline ThreadSafepointState* safepoint_state() const;
612 inline void set_safepoint_state(ThreadSafepointState* state);
613 inline bool is_at_poll_safepoint();
614
615 // JavaThread termination and lifecycle support:
616 void smr_delete();
617 bool on_thread_list() const { return _on_thread_list; }
618 void set_on_thread_list() { _on_thread_list = true; }
619
620 // thread has called JavaThread::exit(), thread's GC barrier is detached
621 // or thread is terminated
622 bool is_exiting() const;
623 // thread's GC barrier is NOT detached and thread is NOT terminated
624 bool is_oop_safe() const;
625 // thread is terminated (no longer on the threads list); the thread must
626 // be protected by a ThreadsListHandle to avoid potential crashes.
627 bool check_is_terminated(TerminatedTypes l_terminated) const {
628 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
629 }
630 bool is_terminated() const;
631 void set_terminated(TerminatedTypes t);
632
633 void block_if_vm_exited();
634
635 bool doing_unsafe_access() { return _doing_unsafe_access; }
636 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
637
638 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
639 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
640
641 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
642
643 static ByteSize polling_word_offset() {
644 ByteSize offset = byte_offset_of(Thread, _poll_data) +
645 byte_offset_of(SafepointMechanism::ThreadData, _polling_word);
646 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
647 assert(in_bytes(offset) < 128, "Offset >= 128");
648 return offset;
649 }
650
651 static ByteSize polling_page_offset() {
652 ByteSize offset = byte_offset_of(Thread, _poll_data) +
653 byte_offset_of(SafepointMechanism::ThreadData, _polling_page);
654 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
655 assert(in_bytes(offset) < 128, "Offset >= 128");
656 return offset;
657 }
658
659 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
660
661 // Continuation support
662 ContinuationEntry* last_continuation() const { return _cont_entry; }
663 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
664 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
665 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
666 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
667 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
668 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
669
670 void inc_held_monitor_count(intx i = 1, bool jni = false);
671 void dec_held_monitor_count(intx i = 1, bool jni = false);
672
673 intx held_monitor_count() { return _held_monitor_count; }
674 intx jni_monitor_count() { return _jni_monitor_count; }
675 void clear_jni_monitor_count() { _jni_monitor_count = 0; }
676
677 // Support for SharedRuntime::monitor_exit_helper()
678 ObjectMonitor* unlocked_inflated_monitor() const { return _unlocked_inflated_monitor; }
679 void clear_unlocked_inflated_monitor() {
680 _unlocked_inflated_monitor = nullptr;
681 }
682
683 inline bool is_vthread_mounted() const;
684 inline const ContinuationEntry* vthread_continuation() const;
685
686 private:
687 DEBUG_ONLY(void verify_frame_info();)
688
689 // Support for thread handshake operations
690 HandshakeState _handshake;
691 public:
692 HandshakeState* handshake_state() { return &_handshake; }
693
694 // A JavaThread can always safely operate on it self and other threads
695 // can do it safely if they are the active handshaker.
696 bool is_handshake_safe_for(Thread* th) const {
697 return _handshake.active_handshaker() == th || this == th;
698 }
699
700 // Suspend/resume support for JavaThread
701 // higher-level suspension/resume logic called by the public APIs
702 bool java_suspend();
703 bool java_resume();
704 bool is_suspended() { return _handshake.is_suspended(); }
705
706 // Check for async exception in addition to safepoint.
707 static void check_special_condition_for_native_trans(JavaThread *thread);
708
709 // Synchronize with another thread that is deoptimizing objects of the
710 // current thread, i.e. reverts optimizations based on escape analysis.
711 void wait_for_object_deoptimization();
712
713 #if INCLUDE_JVMTI
714 inline void set_carrier_thread_suspended();
715 inline void clear_carrier_thread_suspended();
716
717 bool is_carrier_thread_suspended() const {
718 return _carrier_thread_suspended;
719 }
720
721 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
722 void set_is_in_VTMS_transition(bool val);
723
724 bool is_disable_suspend() const { return _is_disable_suspend; }
725 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
726
727 bool is_in_java_upcall() const { return _is_in_java_upcall; }
728 void toggle_is_in_java_upcall() { _is_in_java_upcall = !_is_in_java_upcall; };
729
730 bool VTMS_transition_mark() const { return Atomic::load(&_VTMS_transition_mark); }
731 void set_VTMS_transition_mark(bool val) { Atomic::store(&_VTMS_transition_mark, val); }
732
733 // Temporarily skip posting JVMTI events for safety reasons when executions is in a critical section:
734 // - is in a VTMS transition (_is_in_VTMS_transition)
735 // - is in an interruptLock or similar critical section (_is_disable_suspend)
736 // - JVMTI is making a Java upcall (_is_in_java_upcall)
737 bool should_hide_jvmti_events() const { return _is_in_VTMS_transition || _is_disable_suspend || _is_in_java_upcall; }
738
739 bool on_monitor_waited_event() { return _on_monitor_waited_event; }
740 void set_on_monitor_waited_event(bool val) { _on_monitor_waited_event = val; }
741
742 bool pending_contended_entered_event() { return _contended_entered_monitor != nullptr; }
743 ObjectMonitor* contended_entered_monitor() { return _contended_entered_monitor; }
744 #ifdef ASSERT
745 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
746 void set_is_VTMS_transition_disabler(bool val);
747 #endif
748 #endif
749
750 void set_contended_entered_monitor(ObjectMonitor* val) NOT_JVMTI_RETURN JVMTI_ONLY({ _contended_entered_monitor = val; })
751
752 // Support for object deoptimization and JFR suspension
753 void handle_special_runtime_exit_condition();
754 bool has_special_runtime_exit_condition() {
755 return (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
756 }
757
758 // Stack-locking support (not for LM_LIGHTWEIGHT)
759 bool is_lock_owned(address adr) const;
760
761 // Accessors for vframe array top
762 // The linked list of vframe arrays are sorted on sp. This means when we
763 // unpack the head must contain the vframe array to unpack.
764 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
765 vframeArray* vframe_array_head() const { return _vframe_array_head; }
766
767 // Side structure for deferring update of java frame locals until deopt occurs
768 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
769 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
770
771 // These only really exist to make debugging deopt problems simpler
772
773 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
774 vframeArray* vframe_array_last() const { return _vframe_array_last; }
775
776 // The special resourceMark used during deoptimization
777
778 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
779 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
780
781 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
782 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
783
784 Method* callee_target() const { return _callee_target; }
785 void set_callee_target (Method* x) { _callee_target = x; }
786
787 // Oop results of vm runtime calls
788 oop vm_result_oop() const { return _vm_result_oop; }
789 void set_vm_result_oop(oop x) { _vm_result_oop = x; }
790
791 void set_vm_result_metadata(Metadata* x) { _vm_result_metadata = x; }
792
793 oop return_buffered_value() const { return _return_buffered_value; }
794 void set_return_buffered_value(oop val) { _return_buffered_value = val; }
795
796 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
797 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
798
799 // Is thread in scope of an InternalOOMEMark?
800 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
801 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
802
803 #if INCLUDE_JVMCI
804 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
805 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
806 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
807 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
808 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
809 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
810 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
811
812 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
813 void set_libjvmci_runtime(JVMCIRuntime* rt) {
814 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
815 _libjvmci_runtime = rt;
816 }
817 #endif // INCLUDE_JVMCI
818
819 // Exception handling for compiled methods
820 oop exception_oop() const;
821 address exception_pc() const { return _exception_pc; }
822
823 void set_exception_oop(oop o);
824 void set_exception_pc(address a) { _exception_pc = a; }
825 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
826 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
827
828 void clear_exception_oop_and_pc() {
829 set_exception_oop(nullptr);
830 set_exception_pc(nullptr);
831 }
832
833 // Check if address is in the usable part of the stack (excludes protected
834 // guard pages). Can be applied to any thread and is an approximation for
835 // using is_in_live_stack when the query has to happen from another thread.
836 bool is_in_usable_stack(address adr) const {
837 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
838 }
839
840 // Misc. accessors/mutators
841 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
842
843 // For assembly stub generation
844 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
845 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
846 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
847 static ByteSize pending_jni_exception_check_fn_offset() {
848 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
849 }
850 static ByteSize last_Java_sp_offset() {
851 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
852 }
853 static ByteSize last_Java_pc_offset() {
854 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
855 }
856 static ByteSize frame_anchor_offset() {
857 return byte_offset_of(JavaThread, _anchor);
858 }
859 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
860 static ByteSize vm_result_oop_offset() { return byte_offset_of(JavaThread, _vm_result_oop); }
861 static ByteSize vm_result_metadata_offset() { return byte_offset_of(JavaThread, _vm_result_metadata); }
862 static ByteSize return_buffered_value_offset() { return byte_offset_of(JavaThread, _return_buffered_value); }
863 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
864 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
865 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
866 #if INCLUDE_JVMCI
867 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
868 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
869 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
870 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
871 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
872 #endif // INCLUDE_JVMCI
873 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
874 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
875 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
876 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
877
878 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
879
880 // StackOverflow offsets
881 static ByteSize stack_overflow_limit_offset() {
882 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
883 }
884 static ByteSize stack_guard_state_offset() {
885 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
886 }
887 static ByteSize reserved_stack_activation_offset() {
888 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
889 }
890 static ByteSize shadow_zone_safe_limit() {
891 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
892 }
893 static ByteSize shadow_zone_growth_watermark() {
894 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
895 }
896
897 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
898
899 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
900 static ByteSize should_post_on_exceptions_flag_offset() {
901 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
902 }
903 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
904 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
905
906 static ByteSize monitor_owner_id_offset() { return byte_offset_of(JavaThread, _monitor_owner_id); }
907
908 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
909 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
910 static ByteSize held_monitor_count_offset() { return byte_offset_of(JavaThread, _held_monitor_count); }
911 static ByteSize jni_monitor_count_offset() { return byte_offset_of(JavaThread, _jni_monitor_count); }
912 static ByteSize preemption_cancelled_offset() { return byte_offset_of(JavaThread, _preemption_cancelled); }
913 static ByteSize preempt_alternate_return_offset() { return byte_offset_of(JavaThread, _preempt_alternate_return); }
914 static ByteSize unlocked_inflated_monitor_offset() { return byte_offset_of(JavaThread, _unlocked_inflated_monitor); }
915
916 #if INCLUDE_JVMTI
917 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); }
918 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
919 #endif
920
921 // Returns the jni environment for this thread
922 JNIEnv* jni_environment() { return &_jni_environment; }
923
924 // Returns the current thread as indicated by the given JNIEnv.
925 // We don't assert it is Thread::current here as that is done at the
926 // external JNI entry points where the JNIEnv is passed into the VM.
927 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
928 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
929 // We can't normally get here in a thread that has completed its
930 // execution and so "is_terminated", except when the call is from
931 // AsyncGetCallTrace, which can be triggered by a signal at any point in
932 // a thread's lifecycle. A thread is also considered terminated if the VM
933 // has exited, so we have to check this and block in case this is a daemon
934 // thread returning to the VM (the JNI DirectBuffer entry points rely on
935 // this).
936 if (current->is_terminated()) {
937 current->block_if_vm_exited();
938 }
939 return current;
940 }
941
942 // JNI critical regions. These can nest.
943 bool in_critical() { return _jni_active_critical > 0; }
944 bool in_last_critical() { return _jni_active_critical == 1; }
945 inline void enter_critical();
946 void exit_critical() {
947 assert(Thread::current() == this, "this must be current thread");
948 _jni_active_critical--;
949 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
950 }
951
952 // Atomic version; invoked by a thread other than the owning thread.
953 bool in_critical_atomic() { return Atomic::load(&_jni_active_critical) > 0; }
954
955 // Checked JNI: is the programmer required to check for exceptions, if so specify
956 // which function name. Returning to a Java frame should implicitly clear the
957 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
958 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
959 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
960 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
961 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
962 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
963 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
964
965 // For deadlock detection
966 int depth_first_number() { return _depth_first_number; }
967 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
968
969 public:
970 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
971 void inc_in_deopt_handler() { _in_deopt_handler++; }
972 void dec_in_deopt_handler() {
973 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
974 if (_in_deopt_handler > 0) { // robustness
975 _in_deopt_handler--;
976 }
977 }
978
979 private:
980 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
981
982 // factor out low-level mechanics for use in both normal and error cases
983 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
984
985 public:
986
987 // Frame iteration; calls the function f for all frames on the stack
988 void frames_do(void f(frame*, const RegisterMap*));
989
990 // Memory operations
991 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
992 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
993
994 // GC operations
995 virtual void nmethods_do(NMethodClosure* cf);
996
997 // RedefineClasses Support
998 void metadata_do(MetadataClosure* f);
999
1000 // Debug method asserting thread states are correct during a handshake operation.
1001 DEBUG_ONLY(void verify_states_for_handshake();)
1002
1003 // Misc. operations
1004 const char* name() const;
1005 const char* name_raw() const;
1006 const char* type_name() const { return "JavaThread"; }
1007 static const char* name_for(oop thread_obj);
1008
1009 void print_on(outputStream* st, bool print_extended_info) const;
1010 void print_on(outputStream* st) const { print_on(st, false); }
1011 void print() const;
1012 void print_thread_state_on(outputStream*) const;
1013 void print_on_error(outputStream* st, char* buf, int buflen) const;
1014 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1015 void verify();
1016
1017 // Accessing frames
1018 frame last_frame() {
1019 _anchor.make_walkable();
1020 return pd_last_frame();
1021 }
1022 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
1023
1024 frame carrier_last_frame(RegisterMap* reg_map);
1025 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
1026
1027 frame vthread_last_frame();
1028 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
1029
1030 frame platform_thread_last_frame(RegisterMap* reg_map);
1031 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
1032 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
1033 }
1034
1035 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
1036
1037 // Returns method at 'depth' java or native frames down the stack
1038 // Used for security checks
1039 Klass* security_get_caller_class(int depth);
1040
1041 // Print stack trace in external format
1042 // These variants print carrier/platform thread information only.
1043 void print_stack_on(outputStream* st);
1044 void print_stack() { print_stack_on(tty); }
1045 // This prints the currently mounted virtual thread.
1046 void print_vthread_stack_on(outputStream* st);
1047 // This prints the active stack: either carrier/platform or virtual.
1048 void print_active_stack_on(outputStream* st);
1049 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1050 // This is the external format from above, but selecting the platform
1051 // or vthread as applicable.
1052 void print_jni_stack();
1053
1054 // Print stack traces in various internal formats
1055 void trace_stack() PRODUCT_RETURN;
1056 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1057 void trace_frames() PRODUCT_RETURN;
1058
1059 // Print an annotated view of the stack frames
1060 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1061 void validate_frame_layout() {
1062 print_frame_layout(0, true);
1063 }
1064
1065 // Function for testing deoptimization
1066 void deoptimize();
1067 void make_zombies();
1068
1069 void deoptimize_marked_methods();
1070
1071 public:
1072 // Returns the running thread as a JavaThread
1073 static JavaThread* current() {
1074 return JavaThread::cast(Thread::current());
1075 }
1076
1077 // Returns the current thread as a JavaThread, or nullptr if not attached
1078 static inline JavaThread* current_or_null();
1079
1080 // Casts
1081 static JavaThread* cast(Thread* t) {
1082 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
1083 return static_cast<JavaThread*>(t);
1084 }
1085
1086 static const JavaThread* cast(const Thread* t) {
1087 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1088 return static_cast<const JavaThread*>(t);
1089 }
1090
1091 // Returns the active Java thread. Do not use this if you know you are calling
1092 // from a JavaThread, as it's slower than JavaThread::current. If called from
1093 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1094 // operation. You may not want that either.
1095 static JavaThread* active();
1096
1097 protected:
1098 virtual void pre_run();
1099 virtual void run();
1100 void thread_main_inner();
1101 virtual void post_run();
1102
1103 public:
1104 // Thread local information maintained by JVMTI.
1105 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1106 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1107 // getter is used to get this JavaThread's JvmtiThreadState if it has
1108 // one which means null can be returned. JvmtiThreadState::state_for()
1109 // is used to get the specified JavaThread's JvmtiThreadState if it has
1110 // one or it allocates a new JvmtiThreadState for the JavaThread and
1111 // returns it. JvmtiThreadState::state_for() will return null only if
1112 // the specified JavaThread is exiting.
1113 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1114 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1115
1116 #if INCLUDE_JVMTI
1117 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1118 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1119 #endif
1120
1121 // JVMTI PopFrame support
1122 // Setting and clearing popframe_condition
1123 // All of these enumerated values are bits. popframe_pending
1124 // indicates that a PopFrame() has been requested and not yet been
1125 // completed. popframe_processing indicates that that PopFrame() is in
1126 // the process of being completed. popframe_force_deopt_reexecution_bit
1127 // indicates that special handling is required when returning to a
1128 // deoptimized caller.
1129 enum PopCondition {
1130 popframe_inactive = 0x00,
1131 popframe_pending_bit = 0x01,
1132 popframe_processing_bit = 0x02,
1133 popframe_force_deopt_reexecution_bit = 0x04
1134 };
1135 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1136 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1137 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1138 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1139 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1140 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1141 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1142
1143 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1144 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1145 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1146
1147 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1148 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1149 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1150
1151 private:
1152 // Saved incoming arguments to popped frame.
1153 // Used only when popped interpreted frame returns to deoptimized frame.
1154 void* _popframe_preserved_args;
1155 int _popframe_preserved_args_size;
1156
1157 public:
1158 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1159 void* popframe_preserved_args();
1160 ByteSize popframe_preserved_args_size();
1161 WordSize popframe_preserved_args_size_in_words();
1162 void popframe_free_preserved_args();
1163
1164
1165 private:
1166 JvmtiThreadState *_jvmti_thread_state;
1167
1168 // Used by the interpreter in fullspeed mode for frame pop, method
1169 // entry, method exit and single stepping support. This field is
1170 // only set to non-zero at a safepoint or using a direct handshake
1171 // (see EnterInterpOnlyModeClosure).
1172 // It can be set to zero asynchronously to this threads execution (i.e., without
1173 // safepoint/handshake or a lock) so we have to be very careful.
1174 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1175 int _interp_only_mode;
1176
1177 public:
1178 // used by the interpreter for fullspeed debugging support (see above)
1179 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1180 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1181 int get_interp_only_mode() { return _interp_only_mode; }
1182 int set_interp_only_mode(int val) { return _interp_only_mode = val; }
1183 void increment_interp_only_mode() { ++_interp_only_mode; }
1184 void decrement_interp_only_mode() { --_interp_only_mode; }
1185
1186 // support for cached flag that indicates whether exceptions need to be posted for this thread
1187 // if this is false, we can avoid deoptimizing when events are thrown
1188 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1189 private:
1190 int _should_post_on_exceptions_flag;
1191
1192 public:
1193 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1194
1195 private:
1196 ThreadStatistics *_thread_stat;
1197
1198 public:
1199 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1200
1201 // Return a blocker object for which this thread is blocked parking.
1202 oop current_park_blocker();
1203
1204 private:
1205 static size_t _stack_size_at_create;
1206
1207 public:
1208 static inline size_t stack_size_at_create(void) {
1209 return _stack_size_at_create;
1210 }
1211 static inline void set_stack_size_at_create(size_t value) {
1212 _stack_size_at_create = value;
1213 }
1214
1215 // Machine dependent stuff
1216 #include OS_CPU_HEADER(javaThread)
1217
1218 // JSR166 per-thread parker
1219 private:
1220 Parker _parker;
1221 public:
1222 Parker* parker() { return &_parker; }
1223
1224 public:
1225 // clearing/querying jni attach status
1226 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1227 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1228 inline void set_done_attaching_via_jni();
1229
1230 // Stack dump assistance:
1231 // Track the class we want to initialize but for which we have to wait
1232 // on its init_lock() because it is already being initialized.
1233 void set_class_to_be_initialized(InstanceKlass* k);
1234 InstanceKlass* class_to_be_initialized() const;
1235
1236 // Track executing class initializer, see ThreadInClassInitializer
1237 void set_class_being_initialized(InstanceKlass* k);
1238 InstanceKlass* class_being_initialized() const;
1239
1240 private:
1241 InstanceKlass* _class_to_be_initialized;
1242 InstanceKlass* _class_being_initialized;
1243
1244 // java.lang.Thread.sleep support
1245 ParkEvent * _SleepEvent;
1246
1247 #if INCLUDE_JFR
1248 // Support for jdk.VirtualThreadPinned event
1249 freeze_result _last_freeze_fail_result;
1250 Ticks _last_freeze_fail_time;
1251 #endif
1252
1253 public:
1254 bool sleep(jlong millis);
1255 bool sleep_nanos(jlong nanos);
1256
1257 // java.lang.Thread interruption support
1258 void interrupt();
1259 bool is_interrupted(bool clear_interrupted);
1260
1261 #if INCLUDE_JFR
1262 // Support for jdk.VirtualThreadPinned event
1263 freeze_result last_freeze_fail_result() { return _last_freeze_fail_result; }
1264 Ticks& last_freeze_fail_time() { return _last_freeze_fail_time; }
1265 void set_last_freeze_fail_result(freeze_result result);
1266 #endif
1267 void post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) NOT_JFR_RETURN();
1268
1269
1270 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1271 // the Java code in Object::wait which are not present in RawMonitorWait.
1272 bool get_and_clear_interrupted();
1273
1274 private:
1275 LockStack _lock_stack;
1276 OMCache _om_cache;
1277
1278 public:
1279 LockStack& lock_stack() { return _lock_stack; }
1280
1281 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1282 // Those offsets are used in code generators to access the LockStack that is embedded in this
1283 // JavaThread structure. Those accesses are relative to the current thread, which
1284 // is typically in a dedicated register.
1285 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1286 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1287
1288 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); }
1289 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); }
1290
1291 void om_set_monitor_cache(ObjectMonitor* monitor);
1292 void om_clear_monitor_cache();
1293 ObjectMonitor* om_get_from_monitor_cache(oop obj);
1294
1295 static OopStorage* thread_oop_storage();
1296
1297 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1298
1299 // Helper function to create the java.lang.Thread object for a
1300 // VM-internal thread. The thread will have the given name and be
1301 // part of the System ThreadGroup.
1302 static Handle create_system_thread_object(const char* name, TRAPS);
1303
1304 // Helper function to start a VM-internal daemon thread.
1305 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1306 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1307 Handle thread_oop, ThreadPriority prio);
1308
1309 // Helper function to do vm_exit_on_initialization for osthread
1310 // resource allocation failure.
1311 static void vm_exit_on_osthread_failure(JavaThread* thread);
1312
1313 // Deferred OopHandle release support
1314 private:
1315 // List of OopHandles to be released - guarded by the Service_lock.
1316 static OopHandleList* _oop_handle_list;
1317 // Add our OopHandles to the list for the service thread to release.
1318 void add_oop_handles_for_release();
1319 // Called by the ServiceThread to release the OopHandles.
1320 static void release_oop_handles();
1321 // Called by the ServiceThread to poll if there are any OopHandles to release.
1322 // Called when holding the Service_lock.
1323 static bool has_oop_handles_to_release() {
1324 return _oop_handle_list != nullptr;
1325 }
1326 };
1327
1328 inline JavaThread* JavaThread::current_or_null() {
1329 Thread* current = Thread::current_or_null();
1330 return current != nullptr ? JavaThread::cast(current) : nullptr;
1331 }
1332
1333 class UnlockFlagSaver {
1334 private:
1335 JavaThread* _thread;
1336 bool _do_not_unlock;
1337 public:
1338 UnlockFlagSaver(JavaThread* t) {
1339 _thread = t;
1340 _do_not_unlock = t->do_not_unlock_if_synchronized();
1341 t->set_do_not_unlock_if_synchronized(false);
1342 }
1343 ~UnlockFlagSaver() {
1344 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1345 }
1346 };
1347
1348 class JNIHandleMark : public StackObj {
1349 JavaThread* _thread;
1350 public:
1351 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1352 thread->push_jni_handle_block();
1353 }
1354 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1355 };
1356
1357 class NoPreemptMark {
1358 ContinuationEntry* _ce;
1359 bool _unpin;
1360 public:
1361 NoPreemptMark(JavaThread* thread) : _ce(thread->last_continuation()), _unpin(false) {
1362 if (_ce != nullptr) _unpin = _ce->pin();
1363 }
1364 ~NoPreemptMark() { if (_unpin) _ce->unpin(); }
1365 };
1366
1367 class ThreadOnMonitorWaitedEvent {
1368 JavaThread* _thread;
1369 public:
1370 ThreadOnMonitorWaitedEvent(JavaThread* thread) : _thread(thread) {
1371 JVMTI_ONLY(_thread->set_on_monitor_waited_event(true);)
1372 }
1373 ~ThreadOnMonitorWaitedEvent() { JVMTI_ONLY(_thread->set_on_monitor_waited_event(false);) }
1374 };
1375
1376 class ThreadInClassInitializer : public StackObj {
1377 JavaThread* _thread;
1378 InstanceKlass* _previous;
1379 public:
1380 ThreadInClassInitializer(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
1381 _previous = _thread->class_being_initialized();
1382 _thread->set_class_being_initialized(ik);
1383 }
1384 ~ThreadInClassInitializer() {
1385 _thread->set_class_being_initialized(_previous);
1386 }
1387 };
1388
1389 #endif // SHARE_RUNTIME_JAVATHREAD_HPP