1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #ifndef SHARE_RUNTIME_JAVATHREAD_HPP
27 #define SHARE_RUNTIME_JAVATHREAD_HPP
28
29 #include "jni.h"
30 #include "memory/allocation.hpp"
31 #include "oops/oop.hpp"
32 #include "oops/oopHandle.hpp"
33 #include "runtime/continuationEntry.hpp"
34 #include "runtime/frame.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handshake.hpp"
37 #include "runtime/javaFrameAnchor.hpp"
38 #include "runtime/lockStack.hpp"
39 #include "runtime/park.hpp"
40 #include "runtime/safepointMechanism.hpp"
41 #include "runtime/stackOverflow.hpp"
42 #include "runtime/stackWatermarkSet.hpp"
43 #include "runtime/suspendResumeManager.hpp"
44 #include "runtime/thread.hpp"
45 #include "runtime/threadHeapSampler.hpp"
46 #include "runtime/threadIdentifier.hpp"
47 #include "runtime/threadStatisticalInfo.hpp"
48 #include "utilities/exceptions.hpp"
49 #include "utilities/globalDefinitions.hpp"
50 #include "utilities/macros.hpp"
51 #if INCLUDE_JFR
52 #include "jfr/support/jfrThreadExtension.hpp"
53 #include "utilities/ticks.hpp"
54 #endif
55
56 class AsyncExceptionHandshakeClosure;
57 class DeoptResourceMark;
58 class InternalOOMEMark;
59 class JNIHandleBlock;
60 class JVMCIRuntime;
61
62 class JvmtiDeferredUpdates;
63 class JvmtiSampledObjectAllocEventCollector;
64 class JvmtiThreadState;
65
66 class Metadata;
67 class ObjectMonitor;
68 class OopHandleList;
69 class OopStorage;
70 class OSThread;
71
72 class ThreadsList;
73 class ThreadSafepointState;
74 class ThreadStatistics;
75
76 class vframeArray;
77 class vframe;
78 class javaVFrame;
79
80 class JavaThread;
81 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
82
83 class EventVirtualThreadPinned;
84
85 class JavaThread: public Thread {
86 friend class VMStructs;
87 friend class JVMCIVMStructs;
88 friend class WhiteBox;
89 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
90 friend class HandshakeState;
91 friend class Continuation;
92 friend class Threads;
93 friend class ServiceThread; // for deferred OopHandle release access
94 private:
95 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
96
97 // All references to Java objects managed via OopHandles. These
98 // have to be released by the ServiceThread after the JavaThread has
99 // terminated - see add_oop_handles_for_release().
100 OopHandle _threadObj; // The Java level thread object
101 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj
102 OopHandle _jvmti_vthread;
103 OopHandle _scopedValueCache;
104
105 static OopStorage* _thread_oop_storage;
106
107 #ifdef ASSERT
108 private:
109 int _java_call_counter;
110
111 public:
112 int java_call_counter() { return _java_call_counter; }
113 void inc_java_call_counter() { _java_call_counter++; }
114 void dec_java_call_counter() {
115 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
116 _java_call_counter--;
117 }
118 private: // restore original namespace restriction
119 #endif // ifdef ASSERT
120
121 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
122
123 ThreadFunction _entry_point;
124
125 JNIEnv _jni_environment;
126
127 // Deopt support
128 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
129
130 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
131 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
132 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
133 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
134 // will be carried out as soon as possible which, in most cases, is just before deoptimization of
135 // the frame, when control returns to it.
136 JvmtiDeferredUpdates* _jvmti_deferred_updates;
137
138 // Handshake value for fixing 6243940. We need a place for the i2c
139 // adapter to store the callee Method*. This value is NEVER live
140 // across a gc point so it does NOT have to be gc'd
141 // The handshake is open ended since we can't be certain that it will
142 // be nulled. This is because we rarely ever see the race and end up
143 // in handle_wrong_method which is the backend of the handshake. See
144 // code in i2c adapters and handle_wrong_method.
145
146 Method* _callee_target;
147
148 // Used to pass back results to the interpreter or generated code running Java code.
149 oop _vm_result_oop; // oop result is GC-preserved
150 Metadata* _vm_result_metadata; // non-oop result
151 oop _return_buffered_value; // buffered value being returned
152
153 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
154 bool _current_pending_monitor_is_from_java; // locking is from Java code
155 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
156
157 // Active_handles points to a block of handles
158 JNIHandleBlock* _active_handles;
159
160 // One-element thread local free list
161 JNIHandleBlock* _free_handle_block;
162
163 // ID used as owner for inflated monitors. Same as the j.l.Thread.tid of the
164 // current _vthread object, except during creation of the primordial and JNI
165 // attached thread cases where this field can have a temporary value.
166 int64_t _monitor_owner_id;
167
168 public:
169 void set_monitor_owner_id(int64_t id) {
170 ThreadIdentifier::verify_id(id);
171 _monitor_owner_id = id;
172 }
173 int64_t monitor_owner_id() const {
174 int64_t id = _monitor_owner_id;
175 ThreadIdentifier::verify_id(id);
176 return id;
177 }
178
179 // For tracking the heavyweight monitor the thread is pending on.
180 ObjectMonitor* current_pending_monitor() {
181 // Use AtomicAccess::load() to prevent data race between concurrent modification and
182 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
183 // Especially, reloading pointer from thread after null check must be prevented.
184 return AtomicAccess::load(&_current_pending_monitor);
185 }
186 void set_current_pending_monitor(ObjectMonitor* monitor) {
187 AtomicAccess::store(&_current_pending_monitor, monitor);
188 }
189 void set_current_pending_monitor_is_from_java(bool from_java) {
190 _current_pending_monitor_is_from_java = from_java;
191 }
192 bool current_pending_monitor_is_from_java() {
193 return _current_pending_monitor_is_from_java;
194 }
195 ObjectMonitor* current_waiting_monitor() {
196 // See the comment in current_pending_monitor() above.
197 return AtomicAccess::load(&_current_waiting_monitor);
198 }
199 void set_current_waiting_monitor(ObjectMonitor* monitor) {
200 AtomicAccess::store(&_current_waiting_monitor, monitor);
201 }
202
203 // JNI handle support
204 JNIHandleBlock* active_handles() const { return _active_handles; }
205 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
206 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
207 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
208
209 void push_jni_handle_block();
210 void pop_jni_handle_block();
211
212 private:
213 enum SuspendFlags {
214 // NOTE: avoid using the sign-bit as cc generates different test code
215 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
216 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
217 };
218
219 // various suspension related flags - atomically updated
220 volatile uint32_t _suspend_flags;
221
222 inline void set_suspend_flag(SuspendFlags f);
223 inline void clear_suspend_flag(SuspendFlags f);
224
225 public:
226 inline void set_obj_deopt_flag();
227 inline void clear_obj_deopt_flag();
228 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
229
230 // Asynchronous exception support
231 private:
232 friend class InstallAsyncExceptionHandshakeClosure;
233 friend class AsyncExceptionHandshakeClosure;
234 friend class HandshakeState;
235
236 void handle_async_exception(oop java_throwable);
237 public:
238 void install_async_exception(AsyncExceptionHandshakeClosure* aec = nullptr);
239 bool has_async_exception_condition();
240 inline void set_pending_unsafe_access_error();
241 static void send_async_exception(JavaThread* jt, oop java_throwable);
242
243 class NoAsyncExceptionDeliveryMark : public StackObj {
244 friend JavaThread;
245 JavaThread *_target;
246 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
247 inline ~NoAsyncExceptionDeliveryMark();
248 };
249
250 // Safepoint support
251 public: // Expose _thread_state for SafeFetchInt()
252 volatile JavaThreadState _thread_state;
253 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
254 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
255 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
256 #ifdef ASSERT
257 // Debug support for checking if code allows safepoints or not.
258 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
259 // mutex, or blocking on an object synchronizer (Java locking).
260 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
261 // the above cases. The class NoSafepointVerifier is used to set this counter.
262 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
263
264 public:
265 void inc_no_safepoint_count() { _no_safepoint_count++; }
266 void dec_no_safepoint_count() { _no_safepoint_count--; }
267 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
268 #endif // ASSERT
269 public:
270 // These functions check conditions before possibly going to a safepoint.
271 // including NoSafepointVerifier.
272 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
273 void check_possible_safepoint() NOT_DEBUG_RETURN;
274
275 #ifdef ASSERT
276 private:
277 volatile uint64_t _visited_for_critical_count;
278
279 public:
280 void set_visited_for_critical_count(uint64_t safepoint_id) {
281 assert(_visited_for_critical_count == 0, "Must be reset before set");
282 assert((safepoint_id & 0x1) == 1, "Must be odd");
283 _visited_for_critical_count = safepoint_id;
284 }
285 void reset_visited_for_critical_count(uint64_t safepoint_id) {
286 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
287 _visited_for_critical_count = 0;
288 }
289 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
290 return _visited_for_critical_count == safepoint_id;
291 }
292 #endif // ASSERT
293
294 // JavaThread termination support
295 public:
296 enum TerminatedTypes {
297 _not_terminated = 0xDEAD - 3,
298 _thread_exiting, // JavaThread::exit() has been called for this thread
299 _thread_gc_barrier_detached, // thread's GC barrier has been detached
300 _thread_terminated, // JavaThread is removed from thread list
301 _vm_exited // JavaThread is still executing native code, but VM is terminated
302 // only VM_Exit can set _vm_exited
303 };
304
305 private:
306 // In general a JavaThread's _terminated field transitions as follows:
307 //
308 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
309 //
310 // _vm_exited is a special value to cover the case of a JavaThread
311 // executing native code after the VM itself is terminated.
312 //
313 // A JavaThread that fails to JNI attach has these _terminated field transitions:
314 // _not_terminated => _thread_terminated
315 //
316 volatile TerminatedTypes _terminated;
317
318 jint _in_deopt_handler; // count of deoptimization
319 // handlers thread is in
320 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
321 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
322 // never locked) when throwing an exception. Used by interpreter only.
323 #if INCLUDE_JVMTI
324 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
325 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
326 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
327 bool _is_in_java_upcall; // JVMTI is doing a Java upcall, so JVMTI events must be hidden
328 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers
329 bool _on_monitor_waited_event; // Avoid callee arg processing for enterSpecial when posting waited event
330 ObjectMonitor* _contended_entered_monitor; // Monitor for pending monitor_contended_entered callback
331 #ifdef ASSERT
332 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
333 #endif
334 #endif
335
336 // JNI attach states:
337 enum JNIAttachStates {
338 _not_attaching_via_jni = 1, // thread is not attaching via JNI
339 _attaching_via_jni, // thread is attaching via JNI
340 _attached_via_jni // thread has attached via JNI
341 };
342
343 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
344 // A native thread that is attaching via JNI starts with a value
345 // of _attaching_via_jni and transitions to _attached_via_jni.
346 volatile JNIAttachStates _jni_attach_state;
347
348 // In scope of an InternalOOMEMark?
349 bool _is_in_internal_oome_mark;
350
351 #if INCLUDE_JVMCI
352 // The _pending_* fields below are used to communicate extra information
353 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
354
355 // Communicates the DeoptReason and DeoptAction of the uncommon trap
356 int _pending_deoptimization;
357
358 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
359 // before the monitor has been acquired.
360 bool _pending_monitorenter;
361
362 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
363 bool _pending_transfer_to_interpreter;
364
365 // An id of a speculation that JVMCI compiled code can use to further describe and
366 // uniquely identify the speculative optimization guarded by an uncommon trap.
367 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
368 jlong _pending_failed_speculation;
369
370 // These fields are mutually exclusive in terms of live ranges.
371 union {
372 // Communicates the pc at which the most recent implicit exception occurred
373 // from the signal handler to a deoptimization stub.
374 address _implicit_exception_pc;
375
376 // Communicates an alternative call target to an i2c stub from a JavaCall .
377 address _alternate_call_target;
378 } _jvmci;
379
380 // The JVMCIRuntime in a JVMCI shared library
381 JVMCIRuntime* _libjvmci_runtime;
382
383 // Support for high precision, thread sensitive counters in JVMCI compiled code.
384 jlong* _jvmci_counters;
385
386 // Fast thread locals for use by JVMCI
387 jlong _jvmci_reserved0;
388 jlong _jvmci_reserved1;
389 oop _jvmci_reserved_oop0;
390
391 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
392 // be kept alive
393 nmethod* _live_nmethod;
394
395 public:
396 static jlong* _jvmci_old_thread_counters;
397 static void collect_counters(jlong* array, int length);
398
399 bool resize_counters(int current_size, int new_size);
400
401 static bool resize_all_jvmci_counters(int new_size);
402
403 void set_jvmci_reserved_oop0(oop value) {
404 _jvmci_reserved_oop0 = value;
405 }
406
407 oop get_jvmci_reserved_oop0() {
408 return _jvmci_reserved_oop0;
409 }
410
411 void set_jvmci_reserved0(jlong value) {
412 _jvmci_reserved0 = value;
413 }
414
415 jlong get_jvmci_reserved0() {
416 return _jvmci_reserved0;
417 }
418
419 void set_jvmci_reserved1(jlong value) {
420 _jvmci_reserved1 = value;
421 }
422
423 jlong get_jvmci_reserved1() {
424 return _jvmci_reserved1;
425 }
426
427 void set_live_nmethod(nmethod* nm) {
428 assert(_live_nmethod == nullptr, "only one");
429 _live_nmethod = nm;
430 }
431
432 void clear_live_nmethod() {
433 _live_nmethod = nullptr;
434 }
435
436 private:
437 #endif // INCLUDE_JVMCI
438
439 StackOverflow _stack_overflow_state;
440
441 void pretouch_stack();
442
443 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
444 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
445 // code)
446 volatile oop _exception_oop; // Exception thrown in compiled code
447 volatile address _exception_pc; // PC where exception happened
448 volatile address _exception_handler_pc; // PC for handler of exception
449
450 private:
451 // support for JNI critical regions
452 jint _jni_active_critical; // count of entries into JNI critical region
453
454 // Checked JNI: function name requires exception check
455 char* _pending_jni_exception_check_fn;
456
457 // For deadlock detection.
458 int _depth_first_number;
459
460 // JVMTI PopFrame support
461 // This is set to popframe_pending to signal that top Java frame should be popped immediately
462 int _popframe_condition;
463
464 // If reallocation of scalar replaced objects fails, we throw OOM
465 // and during exception propagation, pop the top
466 // _frames_to_pop_failed_realloc frames, the ones that reference
467 // failed reallocations.
468 int _frames_to_pop_failed_realloc;
469
470 ContinuationEntry* _cont_entry;
471 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub/upcall_stub/native_wrapper
472 // frame inside the continuation that we know about
473 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
474
475 ObjectMonitor* _unlocked_inflated_monitor;
476
477 // This is the field we poke in the interpreter and native
478 // wrapper (Object.wait) to check for preemption.
479 address _preempt_alternate_return;
480 // When preempting on monitorenter we could have acquired the
481 // monitor after freezing all vthread frames. In that case we
482 // set this field so that in the preempt stub we call thaw again
483 // instead of unmounting.
484 bool _preemption_cancelled;
485 // For Object.wait() we set this field to know if we need to
486 // throw IE at the end of thawing before returning to Java.
487 bool _pending_interrupted_exception;
488
489 public:
490 bool preemption_cancelled() { return _preemption_cancelled; }
491 void set_preemption_cancelled(bool b) { _preemption_cancelled = b; }
492
493 bool pending_interrupted_exception() { return _pending_interrupted_exception; }
494 void set_pending_interrupted_exception(bool b) { _pending_interrupted_exception = b; }
495
496 bool preempting() { return _preempt_alternate_return != nullptr; }
497 void set_preempt_alternate_return(address val) { _preempt_alternate_return = val; }
498
499 private:
500
501 friend class VMThread;
502 friend class ThreadWaitTransition;
503 friend class VM_Exit;
504
505 // Stack watermark barriers.
506 StackWatermarks _stack_watermarks;
507
508 public:
509 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
510
511 public:
512 // Constructor
513 JavaThread(MemTag mem_tag = mtThread); // delegating constructor
514 JavaThread(ThreadFunction entry_point, size_t stack_size = 0, MemTag mem_tag = mtThread);
515 ~JavaThread();
516
517 // Factory method to create a new JavaThread whose attach state is "is attaching"
518 static JavaThread* create_attaching_thread();
519
520 #ifdef ASSERT
521 // verify this JavaThread hasn't be published in the Threads::list yet
522 void verify_not_published();
523 #endif // ASSERT
524
525 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
526
527 //JNI functiontable getter/setter for JVMTI jni function table interception API.
528 void set_jni_functions(struct JNINativeInterface_* functionTable) {
529 _jni_environment.functions = functionTable;
530 }
531 struct JNINativeInterface_* get_jni_functions() {
532 return (struct JNINativeInterface_ *)_jni_environment.functions;
533 }
534
535 // This function is called at thread creation to allow
536 // platform specific thread variables to be initialized.
537 void cache_global_variables();
538
539 // Executes Shutdown.shutdown()
540 void invoke_shutdown_hooks();
541
542 // Cleanup on thread exit
543 enum ExitType {
544 normal_exit,
545 jni_detach
546 };
547 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
548
549 void cleanup_failed_attach_current_thread(bool is_daemon);
550
551 // Testers
552 virtual bool is_Java_thread() const { return true; }
553 virtual bool can_call_java() const { return true; }
554
555 virtual bool is_active_Java_thread() const;
556
557 // Thread oop. threadObj() can be null for initial JavaThread
558 // (or for threads attached via JNI)
559 oop threadObj() const;
560 void set_threadOopHandles(oop p);
561 oop vthread() const;
562 void set_vthread(oop p);
563 oop scopedValueCache() const;
564 void set_scopedValueCache(oop p);
565 void clear_scopedValueBindings();
566 oop jvmti_vthread() const;
567 void set_jvmti_vthread(oop p);
568 oop vthread_or_thread() const;
569
570 // Prepare thread and add to priority queue. If a priority is
571 // not specified, use the priority of the thread object. Threads_lock
572 // must be held while this function is called.
573 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
574
575 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
576 address saved_exception_pc() { return _saved_exception_pc; }
577
578 ThreadFunction entry_point() const { return _entry_point; }
579
580 // Allocates a new Java level thread object for this thread. thread_name may be null.
581 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
582
583 // Last frame anchor routines
584
585 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
586
587 // last_Java_sp
588 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
589 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
590
591 // last_Java_pc
592
593 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
594
595 // Safepoint support
596 inline JavaThreadState thread_state() const;
597 inline void set_thread_state(JavaThreadState s);
598 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
599 inline ThreadSafepointState* safepoint_state() const;
600 inline void set_safepoint_state(ThreadSafepointState* state);
601 inline bool is_at_poll_safepoint();
602
603 // JavaThread termination and lifecycle support:
604 void smr_delete();
605 bool on_thread_list() const { return _on_thread_list; }
606 void set_on_thread_list() { _on_thread_list = true; }
607
608 // thread has called JavaThread::exit(), thread's GC barrier is detached
609 // or thread is terminated
610 bool is_exiting() const;
611 // thread's GC barrier is NOT detached and thread is NOT terminated
612 bool is_oop_safe() const;
613 // thread is terminated (no longer on the threads list); the thread must
614 // be protected by a ThreadsListHandle to avoid potential crashes.
615 bool check_is_terminated(TerminatedTypes l_terminated) const {
616 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
617 }
618 bool is_terminated() const;
619 void set_terminated(TerminatedTypes t);
620
621 void block_if_vm_exited();
622
623 bool doing_unsafe_access() { return _doing_unsafe_access; }
624 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
625
626 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
627 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
628
629 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
630
631 static ByteSize polling_word_offset() {
632 ByteSize offset = byte_offset_of(Thread, _poll_data) +
633 byte_offset_of(SafepointMechanism::ThreadData, _polling_word);
634 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
635 assert(in_bytes(offset) < 128, "Offset >= 128");
636 return offset;
637 }
638
639 static ByteSize polling_page_offset() {
640 ByteSize offset = byte_offset_of(Thread, _poll_data) +
641 byte_offset_of(SafepointMechanism::ThreadData, _polling_page);
642 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
643 assert(in_bytes(offset) < 128, "Offset >= 128");
644 return offset;
645 }
646
647 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
648
649 // Continuation support
650 ContinuationEntry* last_continuation() const { return _cont_entry; }
651 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
652 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
653 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
654 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
655 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
656 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
657
658 // Support for SharedRuntime::monitor_exit_helper()
659 ObjectMonitor* unlocked_inflated_monitor() const { return _unlocked_inflated_monitor; }
660 void clear_unlocked_inflated_monitor() {
661 _unlocked_inflated_monitor = nullptr;
662 }
663
664 inline bool is_vthread_mounted() const;
665 inline const ContinuationEntry* vthread_continuation() const;
666
667 private:
668 DEBUG_ONLY(void verify_frame_info();)
669
670 // Support for thread handshake operations
671 HandshakeState _handshake;
672 public:
673 HandshakeState* handshake_state() { return &_handshake; }
674
675 // A JavaThread can always safely operate on it self and other threads
676 // can do it safely if they are the active handshaker.
677 bool is_handshake_safe_for(Thread* th) const {
678 return _handshake.active_handshaker() == th || this == th;
679 }
680
681 // Suspend/resume support for JavaThread
682 // higher-level suspension/resume logic called by the public APIs
683 private:
684 SuspendResumeManager _suspend_resume_manager;
685 public:
686 bool java_suspend(bool register_vthread_SR);
687 bool java_resume(bool register_vthread_SR);
688 bool is_suspended() { return _suspend_resume_manager.is_suspended(); }
689 SuspendResumeManager* suspend_resume_manager() { return &_suspend_resume_manager; }
690
691 // Check for async exception in addition to safepoint.
692 static void check_special_condition_for_native_trans(JavaThread *thread);
693
694 // Synchronize with another thread that is deoptimizing objects of the
695 // current thread, i.e. reverts optimizations based on escape analysis.
696 void wait_for_object_deoptimization();
697
698 #if INCLUDE_JVMTI
699 inline bool set_carrier_thread_suspended();
700 inline bool clear_carrier_thread_suspended();
701
702 bool is_carrier_thread_suspended() const {
703 return AtomicAccess::load(&_carrier_thread_suspended);
704 }
705
706 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
707 void set_is_in_VTMS_transition(bool val);
708
709 bool is_disable_suspend() const { return _is_disable_suspend; }
710 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
711
712 bool is_in_java_upcall() const { return _is_in_java_upcall; }
713 void toggle_is_in_java_upcall() { _is_in_java_upcall = !_is_in_java_upcall; };
714
715 bool VTMS_transition_mark() const { return AtomicAccess::load(&_VTMS_transition_mark); }
716 void set_VTMS_transition_mark(bool val) { AtomicAccess::store(&_VTMS_transition_mark, val); }
717
718 // Temporarily skip posting JVMTI events for safety reasons when executions is in a critical section:
719 // - is in a VTMS transition (_is_in_VTMS_transition)
720 // - is in an interruptLock or similar critical section (_is_disable_suspend)
721 // - JVMTI is making a Java upcall (_is_in_java_upcall)
722 bool should_hide_jvmti_events() const { return _is_in_VTMS_transition || _is_disable_suspend || _is_in_java_upcall; }
723
724 bool on_monitor_waited_event() { return _on_monitor_waited_event; }
725 void set_on_monitor_waited_event(bool val) { _on_monitor_waited_event = val; }
726
727 bool pending_contended_entered_event() { return _contended_entered_monitor != nullptr; }
728 ObjectMonitor* contended_entered_monitor() { return _contended_entered_monitor; }
729 #ifdef ASSERT
730 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
731 void set_is_VTMS_transition_disabler(bool val);
732 #endif
733 #endif
734
735 void set_contended_entered_monitor(ObjectMonitor* val) NOT_JVMTI_RETURN JVMTI_ONLY({ _contended_entered_monitor = val; })
736
737 // Support for object deoptimization and JFR suspension
738 void handle_special_runtime_exit_condition();
739 bool has_special_runtime_exit_condition() {
740 return (_suspend_flags & _obj_deopt) != 0;
741 }
742
743 // Accessors for vframe array top
744 // The linked list of vframe arrays are sorted on sp. This means when we
745 // unpack the head must contain the vframe array to unpack.
746 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
747 vframeArray* vframe_array_head() const { return _vframe_array_head; }
748
749 // Side structure for deferring update of java frame locals until deopt occurs
750 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
751 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
752
753 // These only really exist to make debugging deopt problems simpler
754
755 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
756 vframeArray* vframe_array_last() const { return _vframe_array_last; }
757
758 // The special resourceMark used during deoptimization
759
760 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
761 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
762
763 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
764 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
765
766 Method* callee_target() const { return _callee_target; }
767 void set_callee_target (Method* x) { _callee_target = x; }
768
769 // Oop results of vm runtime calls
770 oop vm_result_oop() const { return _vm_result_oop; }
771 void set_vm_result_oop(oop x) { _vm_result_oop = x; }
772
773 void set_vm_result_metadata(Metadata* x) { _vm_result_metadata = x; }
774
775 oop return_buffered_value() const { return _return_buffered_value; }
776 void set_return_buffered_value(oop val) { _return_buffered_value = val; }
777
778 // Is thread in scope of an InternalOOMEMark?
779 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
780 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
781
782 #if INCLUDE_JVMCI
783 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
784 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
785 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
786 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
787 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
788 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
789 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
790
791 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
792 void set_libjvmci_runtime(JVMCIRuntime* rt) {
793 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
794 _libjvmci_runtime = rt;
795 }
796 #endif // INCLUDE_JVMCI
797
798 // Exception handling for compiled methods
799 oop exception_oop() const;
800 address exception_pc() const { return _exception_pc; }
801
802 void set_exception_oop(oop o);
803 void set_exception_pc(address a) { _exception_pc = a; }
804 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
805
806 void clear_exception_oop_and_pc() {
807 set_exception_oop(nullptr);
808 set_exception_pc(nullptr);
809 }
810
811 // Check if address is in the usable part of the stack (excludes protected
812 // guard pages). Can be applied to any thread and is an approximation for
813 // using is_in_live_stack when the query has to happen from another thread.
814 bool is_in_usable_stack(address adr) const {
815 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
816 }
817
818 // Misc. accessors/mutators
819 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
820
821 // For assembly stub generation
822 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
823 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
824 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
825 static ByteSize pending_jni_exception_check_fn_offset() {
826 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
827 }
828 static ByteSize last_Java_sp_offset() {
829 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
830 }
831 static ByteSize last_Java_pc_offset() {
832 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
833 }
834 static ByteSize frame_anchor_offset() {
835 return byte_offset_of(JavaThread, _anchor);
836 }
837 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
838 static ByteSize vm_result_oop_offset() { return byte_offset_of(JavaThread, _vm_result_oop); }
839 static ByteSize vm_result_metadata_offset() { return byte_offset_of(JavaThread, _vm_result_metadata); }
840 static ByteSize return_buffered_value_offset() { return byte_offset_of(JavaThread, _return_buffered_value); }
841 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
842 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
843 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
844 #if INCLUDE_JVMCI
845 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
846 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
847 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
848 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
849 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
850 #endif // INCLUDE_JVMCI
851 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
852 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
853 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
854
855 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
856
857 // StackOverflow offsets
858 static ByteSize stack_overflow_limit_offset() {
859 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
860 }
861 static ByteSize stack_guard_state_offset() {
862 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
863 }
864 static ByteSize reserved_stack_activation_offset() {
865 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
866 }
867 static ByteSize shadow_zone_safe_limit() {
868 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
869 }
870 static ByteSize shadow_zone_growth_watermark() {
871 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
872 }
873
874 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
875
876 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
877 static ByteSize should_post_on_exceptions_flag_offset() {
878 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
879 }
880 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
881 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
882
883 static ByteSize monitor_owner_id_offset() { return byte_offset_of(JavaThread, _monitor_owner_id); }
884
885 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
886 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
887 static ByteSize preemption_cancelled_offset() { return byte_offset_of(JavaThread, _preemption_cancelled); }
888 static ByteSize preempt_alternate_return_offset() { return byte_offset_of(JavaThread, _preempt_alternate_return); }
889 static ByteSize unlocked_inflated_monitor_offset() { return byte_offset_of(JavaThread, _unlocked_inflated_monitor); }
890
891 #if INCLUDE_JVMTI
892 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); }
893 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
894 #endif
895
896 // Returns the jni environment for this thread
897 JNIEnv* jni_environment() { return &_jni_environment; }
898
899 // Returns the current thread as indicated by the given JNIEnv.
900 // We don't assert it is Thread::current here as that is done at the
901 // external JNI entry points where the JNIEnv is passed into the VM.
902 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
903 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
904 // We can't normally get here in a thread that has completed its
905 // execution and so "is_terminated", except when the call is from
906 // AsyncGetCallTrace, which can be triggered by a signal at any point in
907 // a thread's lifecycle. A thread is also considered terminated if the VM
908 // has exited, so we have to check this and block in case this is a daemon
909 // thread returning to the VM (the JNI DirectBuffer entry points rely on
910 // this).
911 if (current->is_terminated()) {
912 current->block_if_vm_exited();
913 }
914 return current;
915 }
916
917 // JNI critical regions. These can nest.
918 bool in_critical() { return _jni_active_critical > 0; }
919 bool in_last_critical() { return _jni_active_critical == 1; }
920 inline void enter_critical();
921 void exit_critical() {
922 assert(Thread::current() == this, "this must be current thread");
923 _jni_active_critical--;
924 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
925 }
926
927 // Atomic version; invoked by a thread other than the owning thread.
928 bool in_critical_atomic() { return AtomicAccess::load(&_jni_active_critical) > 0; }
929
930 // Checked JNI: is the programmer required to check for exceptions, if so specify
931 // which function name. Returning to a Java frame should implicitly clear the
932 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
933 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
934 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
935 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
936 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
937 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
938 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
939
940 // For deadlock detection
941 int depth_first_number() { return _depth_first_number; }
942 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
943
944 public:
945 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
946 void inc_in_deopt_handler() { _in_deopt_handler++; }
947 void dec_in_deopt_handler() {
948 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
949 if (_in_deopt_handler > 0) { // robustness
950 _in_deopt_handler--;
951 }
952 }
953
954 private:
955 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
956
957 // factor out low-level mechanics for use in both normal and error cases
958 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
959
960 public:
961
962 // Frame iteration; calls the function f for all frames on the stack
963 void frames_do(void f(frame*, const RegisterMap*));
964
965 // Memory operations
966 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
967 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
968
969 // GC operations
970 virtual void nmethods_do(NMethodClosure* cf);
971
972 // RedefineClasses Support
973 void metadata_do(MetadataClosure* f);
974
975 // Debug method asserting thread states are correct during a handshake operation.
976 DEBUG_ONLY(void verify_states_for_handshake();)
977
978 // Misc. operations
979 const char* name() const;
980 const char* name_raw() const;
981 const char* type_name() const { return "JavaThread"; }
982 static const char* name_for(oop thread_obj);
983
984 void print_on(outputStream* st, bool print_extended_info) const;
985 void print_on(outputStream* st) const { print_on(st, false); }
986 void print() const;
987 void print_thread_state_on(outputStream*) const;
988 void print_on_error(outputStream* st, char* buf, int buflen) const;
989 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
990 void verify();
991
992 // Accessing frames
993 frame last_frame() {
994 _anchor.make_walkable();
995 return pd_last_frame();
996 }
997 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
998
999 frame carrier_last_frame(RegisterMap* reg_map);
1000 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
1001
1002 frame vthread_last_frame();
1003 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
1004
1005 frame platform_thread_last_frame(RegisterMap* reg_map);
1006 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
1007 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
1008 }
1009
1010 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
1011
1012 // Returns method at 'depth' java or native frames down the stack
1013 // Used for security checks
1014 Klass* security_get_caller_class(int depth);
1015
1016 // Print stack trace in external format
1017 // These variants print carrier/platform thread information only.
1018 void print_stack_on(outputStream* st);
1019 void print_stack() { print_stack_on(tty); }
1020 // This prints the currently mounted virtual thread.
1021 void print_vthread_stack_on(outputStream* st);
1022 // This prints the active stack: either carrier/platform or virtual.
1023 void print_active_stack_on(outputStream* st);
1024 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1025 // This is the external format from above, but selecting the platform
1026 // or vthread as applicable.
1027 void print_jni_stack();
1028
1029 // Print stack traces in various internal formats
1030 void trace_stack() PRODUCT_RETURN;
1031 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1032 void trace_frames() PRODUCT_RETURN;
1033
1034 // Print an annotated view of the stack frames
1035 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1036 void validate_frame_layout() {
1037 print_frame_layout(0, true);
1038 }
1039
1040 // Function for testing deoptimization
1041 void deoptimize();
1042 void make_zombies();
1043
1044 void deoptimize_marked_methods();
1045
1046 public:
1047 // Returns the running thread as a JavaThread
1048 static JavaThread* current() {
1049 return JavaThread::cast(Thread::current());
1050 }
1051
1052 // Returns the current thread as a JavaThread, or nullptr if not attached
1053 static inline JavaThread* current_or_null();
1054
1055 // Casts
1056 static JavaThread* cast(Thread* t) {
1057 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
1058 return static_cast<JavaThread*>(t);
1059 }
1060
1061 static const JavaThread* cast(const Thread* t) {
1062 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1063 return static_cast<const JavaThread*>(t);
1064 }
1065
1066 // Returns the active Java thread. Do not use this if you know you are calling
1067 // from a JavaThread, as it's slower than JavaThread::current. If called from
1068 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1069 // operation. You may not want that either.
1070 static JavaThread* active();
1071
1072 protected:
1073 virtual void pre_run();
1074 virtual void run();
1075 void thread_main_inner();
1076 virtual void post_run();
1077
1078 public:
1079 // Thread local information maintained by JVMTI.
1080 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1081 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1082 // getter is used to get this JavaThread's JvmtiThreadState if it has
1083 // one which means null can be returned. JvmtiThreadState::state_for()
1084 // is used to get the specified JavaThread's JvmtiThreadState if it has
1085 // one or it allocates a new JvmtiThreadState for the JavaThread and
1086 // returns it. JvmtiThreadState::state_for() will return null only if
1087 // the specified JavaThread is exiting.
1088 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1089 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1090
1091 #if INCLUDE_JVMTI
1092 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1093 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1094 #endif
1095
1096 // JVMTI PopFrame support
1097 // Setting and clearing popframe_condition
1098 // All of these enumerated values are bits. popframe_pending
1099 // indicates that a PopFrame() has been requested and not yet been
1100 // completed. popframe_processing indicates that that PopFrame() is in
1101 // the process of being completed. popframe_force_deopt_reexecution_bit
1102 // indicates that special handling is required when returning to a
1103 // deoptimized caller.
1104 enum PopCondition {
1105 popframe_inactive = 0x00,
1106 popframe_pending_bit = 0x01,
1107 popframe_processing_bit = 0x02,
1108 popframe_force_deopt_reexecution_bit = 0x04
1109 };
1110 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1111 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1112 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1113 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1114 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1115 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1116 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1117
1118 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1119 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1120 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1121
1122 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1123 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1124 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1125
1126 private:
1127 // Saved incoming arguments to popped frame.
1128 // Used only when popped interpreted frame returns to deoptimized frame.
1129 void* _popframe_preserved_args;
1130 int _popframe_preserved_args_size;
1131
1132 public:
1133 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1134 void* popframe_preserved_args();
1135 ByteSize popframe_preserved_args_size();
1136 WordSize popframe_preserved_args_size_in_words();
1137 void popframe_free_preserved_args();
1138
1139
1140 private:
1141 JvmtiThreadState *_jvmti_thread_state;
1142
1143 // Used by the interpreter in fullspeed mode for frame pop, method
1144 // entry, method exit and single stepping support. This field is
1145 // only set to non-zero at a safepoint or using a direct handshake
1146 // (see EnterInterpOnlyModeHandshakeClosure).
1147 // It can be set to zero asynchronously to this threads execution (i.e., without
1148 // safepoint/handshake or a lock) so we have to be very careful.
1149 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1150 // This field is checked by the interpreter which expects it to be an integer.
1151 int _interp_only_mode;
1152
1153 public:
1154 // used by the interpreter for fullspeed debugging support (see above)
1155 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1156 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1157 void set_interp_only_mode(bool val) { _interp_only_mode = val ? 1 : 0; }
1158
1159 // support for cached flag that indicates whether exceptions need to be posted for this thread
1160 // if this is false, we can avoid deoptimizing when events are thrown
1161 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1162 private:
1163 int _should_post_on_exceptions_flag;
1164
1165 public:
1166 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1167
1168 private:
1169 ThreadStatistics *_thread_stat;
1170
1171 public:
1172 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1173
1174 // Return a blocker object for which this thread is blocked parking.
1175 oop current_park_blocker();
1176
1177 private:
1178 static size_t _stack_size_at_create;
1179
1180 public:
1181 static inline size_t stack_size_at_create(void) {
1182 return _stack_size_at_create;
1183 }
1184 static inline void set_stack_size_at_create(size_t value) {
1185 _stack_size_at_create = value;
1186 }
1187
1188 // Machine dependent stuff
1189 #include OS_CPU_HEADER(javaThread)
1190
1191 // JSR166 per-thread parker
1192 private:
1193 Parker _parker;
1194 public:
1195 Parker* parker() { return &_parker; }
1196
1197 public:
1198 // clearing/querying jni attach status
1199 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1200 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1201 inline void set_done_attaching_via_jni();
1202
1203 // Stack dump assistance:
1204 // Track the class we want to initialize but for which we have to wait
1205 // on its init_lock() because it is already being initialized.
1206 void set_class_to_be_initialized(InstanceKlass* k);
1207 InstanceKlass* class_to_be_initialized() const;
1208
1209 // Track executing class initializer, see ThreadInClassInitializer
1210 void set_class_being_initialized(InstanceKlass* k);
1211 InstanceKlass* class_being_initialized() const;
1212
1213 private:
1214 InstanceKlass* _class_to_be_initialized;
1215 InstanceKlass* _class_being_initialized;
1216
1217 // java.lang.Thread.sleep support
1218 ParkEvent * _SleepEvent;
1219
1220 #if INCLUDE_JFR
1221 // Support for jdk.VirtualThreadPinned event
1222 freeze_result _last_freeze_fail_result;
1223 Ticks _last_freeze_fail_time;
1224 #endif
1225
1226 public:
1227 bool sleep(jlong millis);
1228 bool sleep_nanos(jlong nanos);
1229
1230 // java.lang.Thread interruption support
1231 void interrupt();
1232 bool is_interrupted(bool clear_interrupted);
1233
1234 #if INCLUDE_JFR
1235 // Support for jdk.VirtualThreadPinned event
1236 freeze_result last_freeze_fail_result() { return _last_freeze_fail_result; }
1237 Ticks& last_freeze_fail_time() { return _last_freeze_fail_time; }
1238 void set_last_freeze_fail_result(freeze_result result);
1239 #endif
1240 void post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) NOT_JFR_RETURN();
1241
1242
1243 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1244 // the Java code in Object::wait which are not present in RawMonitorWait.
1245 bool get_and_clear_interrupted();
1246
1247 private:
1248 LockStack _lock_stack;
1249 OMCache _om_cache;
1250
1251 public:
1252 LockStack& lock_stack() { return _lock_stack; }
1253
1254 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1255 // Those offsets are used in code generators to access the LockStack that is embedded in this
1256 // JavaThread structure. Those accesses are relative to the current thread, which
1257 // is typically in a dedicated register.
1258 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1259 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1260
1261 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); }
1262 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); }
1263
1264 void om_set_monitor_cache(ObjectMonitor* monitor);
1265 void om_clear_monitor_cache();
1266 ObjectMonitor* om_get_from_monitor_cache(oop obj);
1267
1268 static OopStorage* thread_oop_storage();
1269
1270 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1271
1272 // Helper function to create the java.lang.Thread object for a
1273 // VM-internal thread. The thread will have the given name and be
1274 // part of the System ThreadGroup.
1275 static Handle create_system_thread_object(const char* name, TRAPS);
1276
1277 // Helper function to start a VM-internal daemon thread.
1278 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1279 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1280 Handle thread_oop, ThreadPriority prio);
1281
1282 // Helper function to do vm_exit_on_initialization for osthread
1283 // resource allocation failure.
1284 static void vm_exit_on_osthread_failure(JavaThread* thread);
1285
1286 // Deferred OopHandle release support
1287 private:
1288 // List of OopHandles to be released - guarded by the Service_lock.
1289 static OopHandleList* _oop_handle_list;
1290 // Add our OopHandles to the list for the service thread to release.
1291 void add_oop_handles_for_release();
1292 // Called by the ServiceThread to release the OopHandles.
1293 static void release_oop_handles();
1294 // Called by the ServiceThread to poll if there are any OopHandles to release.
1295 // Called when holding the Service_lock.
1296 static bool has_oop_handles_to_release() {
1297 return _oop_handle_list != nullptr;
1298 }
1299 };
1300
1301 inline JavaThread* JavaThread::current_or_null() {
1302 Thread* current = Thread::current_or_null();
1303 return current != nullptr ? JavaThread::cast(current) : nullptr;
1304 }
1305
1306 class UnlockFlagSaver {
1307 private:
1308 JavaThread* _thread;
1309 bool _do_not_unlock;
1310 public:
1311 UnlockFlagSaver(JavaThread* t) {
1312 _thread = t;
1313 _do_not_unlock = t->do_not_unlock_if_synchronized();
1314 t->set_do_not_unlock_if_synchronized(false);
1315 }
1316 ~UnlockFlagSaver() {
1317 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1318 }
1319 };
1320
1321 class JNIHandleMark : public StackObj {
1322 JavaThread* _thread;
1323 public:
1324 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1325 thread->push_jni_handle_block();
1326 }
1327 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1328 };
1329
1330 class NoPreemptMark {
1331 ContinuationEntry* _ce;
1332 bool _unpin;
1333 public:
1334 NoPreemptMark(JavaThread* thread) : _ce(thread->last_continuation()), _unpin(false) {
1335 if (_ce != nullptr) _unpin = _ce->pin();
1336 }
1337 ~NoPreemptMark() { if (_unpin) _ce->unpin(); }
1338 };
1339
1340 class ThreadOnMonitorWaitedEvent {
1341 JavaThread* _thread;
1342 public:
1343 ThreadOnMonitorWaitedEvent(JavaThread* thread) : _thread(thread) {
1344 JVMTI_ONLY(_thread->set_on_monitor_waited_event(true);)
1345 }
1346 ~ThreadOnMonitorWaitedEvent() { JVMTI_ONLY(_thread->set_on_monitor_waited_event(false);) }
1347 };
1348
1349 class ThreadInClassInitializer : public StackObj {
1350 JavaThread* _thread;
1351 InstanceKlass* _previous;
1352 public:
1353 ThreadInClassInitializer(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
1354 _previous = _thread->class_being_initialized();
1355 _thread->set_class_being_initialized(ik);
1356 }
1357 ~ThreadInClassInitializer() {
1358 _thread->set_class_being_initialized(_previous);
1359 }
1360 };
1361
1362 #endif // SHARE_RUNTIME_JAVATHREAD_HPP