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 result is GC-preserved
149 Metadata* _vm_result_2; // non-oop result
150
151 // See ReduceInitialCardMarks: this holds the precise space interval of
152 // the most recent slow path allocation for which compiled code has
153 // elided card-marks for performance along the fast-path.
154 MemRegion _deferred_card_mark;
155
156 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
157 bool _current_pending_monitor_is_from_java; // locking is from Java code
158 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
159
160 // Active_handles points to a block of handles
161 JNIHandleBlock* _active_handles;
162
163 // One-element thread local free list
164 JNIHandleBlock* _free_handle_block;
165
166 // ID used as owner for inflated monitors. Same as the j.l.Thread.tid of the
167 // current _vthread object, except during creation of the primordial and JNI
168 // attached thread cases where this field can have a temporary value.
169 int64_t _monitor_owner_id;
170
171 public:
172 void set_monitor_owner_id(int64_t id) {
173 assert(id >= ThreadIdentifier::initial() && id < ThreadIdentifier::current(), "");
174 _monitor_owner_id = id;
175 }
176 int64_t monitor_owner_id() const { return _monitor_owner_id; }
177
178 // For tracking the heavyweight monitor the thread is pending on.
179 ObjectMonitor* current_pending_monitor() {
180 // Use Atomic::load() to prevent data race between concurrent modification and
181 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
182 // Especially, reloading pointer from thread after null check must be prevented.
183 return Atomic::load(&_current_pending_monitor);
184 }
185 void set_current_pending_monitor(ObjectMonitor* monitor) {
186 Atomic::store(&_current_pending_monitor, monitor);
187 }
188 void set_current_pending_monitor_is_from_java(bool from_java) {
189 _current_pending_monitor_is_from_java = from_java;
190 }
191 bool current_pending_monitor_is_from_java() {
192 return _current_pending_monitor_is_from_java;
193 }
194 ObjectMonitor* current_waiting_monitor() {
195 // See the comment in current_pending_monitor() above.
196 return Atomic::load(&_current_waiting_monitor);
197 }
198 void set_current_waiting_monitor(ObjectMonitor* monitor) {
199 Atomic::store(&_current_waiting_monitor, monitor);
200 }
201
202 // JNI handle support
203 JNIHandleBlock* active_handles() const { return _active_handles; }
204 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
205 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
206 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
207
208 void push_jni_handle_block();
209 void pop_jni_handle_block();
210
211 private:
212 enum SuspendFlags {
213 // NOTE: avoid using the sign-bit as cc generates different test code
214 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
215 _trace_flag = 0x00000004U, // call tracing backend
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_trace_flag();
227 inline void clear_trace_flag();
228 inline void set_obj_deopt_flag();
229 inline void clear_obj_deopt_flag();
230 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
231 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
232
233 // Asynchronous exception support
234 private:
235 friend class InstallAsyncExceptionHandshake;
236 friend class AsyncExceptionHandshake;
237 friend class HandshakeState;
238
239 void handle_async_exception(oop java_throwable);
240 public:
241 void install_async_exception(AsyncExceptionHandshake* aec = nullptr);
242 bool has_async_exception_condition();
243 inline void set_pending_unsafe_access_error();
244 static void send_async_exception(JavaThread* jt, oop java_throwable);
245
246 class NoAsyncExceptionDeliveryMark : public StackObj {
247 friend JavaThread;
248 JavaThread *_target;
249 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
250 inline ~NoAsyncExceptionDeliveryMark();
251 };
252
253 // Safepoint support
254 public: // Expose _thread_state for SafeFetchInt()
255 volatile JavaThreadState _thread_state;
256 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
257 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
258 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
259 #ifdef ASSERT
260 // Debug support for checking if code allows safepoints or not.
261 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
262 // mutex, or blocking on an object synchronizer (Java locking).
263 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
264 // the above cases. The class NoSafepointVerifier is used to set this counter.
265 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
266
267 public:
268 void inc_no_safepoint_count() { _no_safepoint_count++; }
269 void dec_no_safepoint_count() { _no_safepoint_count--; }
270 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
271 #endif // ASSERT
272 public:
273 // These functions check conditions before possibly going to a safepoint.
274 // including NoSafepointVerifier.
275 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
276 void check_possible_safepoint() NOT_DEBUG_RETURN;
277
278 #ifdef ASSERT
279 private:
280 volatile uint64_t _visited_for_critical_count;
281
282 public:
283 void set_visited_for_critical_count(uint64_t safepoint_id) {
284 assert(_visited_for_critical_count == 0, "Must be reset before set");
285 assert((safepoint_id & 0x1) == 1, "Must be odd");
286 _visited_for_critical_count = safepoint_id;
287 }
288 void reset_visited_for_critical_count(uint64_t safepoint_id) {
289 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
290 _visited_for_critical_count = 0;
291 }
292 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
293 return _visited_for_critical_count == safepoint_id;
294 }
295 #endif // ASSERT
296
297 // JavaThread termination support
298 public:
299 enum TerminatedTypes {
300 _not_terminated = 0xDEAD - 3,
301 _thread_exiting, // JavaThread::exit() has been called for this thread
302 _thread_gc_barrier_detached, // thread's GC barrier has been detached
303 _thread_terminated, // JavaThread is removed from thread list
304 _vm_exited // JavaThread is still executing native code, but VM is terminated
305 // only VM_Exit can set _vm_exited
306 };
307
308 private:
309 // In general a JavaThread's _terminated field transitions as follows:
310 //
311 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
312 //
313 // _vm_exited is a special value to cover the case of a JavaThread
314 // executing native code after the VM itself is terminated.
315 //
316 // A JavaThread that fails to JNI attach has these _terminated field transitions:
317 // _not_terminated => _thread_terminated
318 //
319 volatile TerminatedTypes _terminated;
320
321 jint _in_deopt_handler; // count of deoptimization
322 // handlers thread is in
323 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
324 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
325 // never locked) when throwing an exception. Used by interpreter only.
326 #if INCLUDE_JVMTI
327 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
328 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
329 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
330 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers
331 bool _on_monitor_waited_event; // Avoid callee arg processing for enterSpecial when posting waited event
332 ObjectMonitor* _contended_entered_monitor; // Monitor for pending monitor_contended_entered callback
333 #ifdef ASSERT
334 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
335 #endif
336 #endif
337
338 // JNI attach states:
339 enum JNIAttachStates {
340 _not_attaching_via_jni = 1, // thread is not attaching via JNI
341 _attaching_via_jni, // thread is attaching via JNI
342 _attached_via_jni // thread has attached via JNI
343 };
344
345 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
346 // A native thread that is attaching via JNI starts with a value
347 // of _attaching_via_jni and transitions to _attached_via_jni.
348 volatile JNIAttachStates _jni_attach_state;
349
350 // In scope of an InternalOOMEMark?
351 bool _is_in_internal_oome_mark;
352
353 #if INCLUDE_JVMCI
354 // The _pending_* fields below are used to communicate extra information
355 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
356
357 // Communicates the DeoptReason and DeoptAction of the uncommon trap
358 int _pending_deoptimization;
359
360 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
361 // before the monitor has been acquired.
362 bool _pending_monitorenter;
363
364 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
365 bool _pending_transfer_to_interpreter;
366
367 // An id of a speculation that JVMCI compiled code can use to further describe and
368 // uniquely identify the speculative optimization guarded by an uncommon trap.
369 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
370 jlong _pending_failed_speculation;
371
372 // These fields are mutually exclusive in terms of live ranges.
373 union {
374 // Communicates the pc at which the most recent implicit exception occurred
375 // from the signal handler to a deoptimization stub.
376 address _implicit_exception_pc;
377
378 // Communicates an alternative call target to an i2c stub from a JavaCall .
379 address _alternate_call_target;
380 } _jvmci;
381
382 // The JVMCIRuntime in a JVMCI shared library
383 JVMCIRuntime* _libjvmci_runtime;
384
385 // Support for high precision, thread sensitive counters in JVMCI compiled code.
386 jlong* _jvmci_counters;
387
388 // Fast thread locals for use by JVMCI
389 jlong _jvmci_reserved0;
390 jlong _jvmci_reserved1;
391 oop _jvmci_reserved_oop0;
392
393 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
394 // be kept alive
395 nmethod* _live_nmethod;
396
397 public:
398 static jlong* _jvmci_old_thread_counters;
399 static void collect_counters(jlong* array, int length);
400
401 bool resize_counters(int current_size, int new_size);
402
403 static bool resize_all_jvmci_counters(int new_size);
404
405 void set_jvmci_reserved_oop0(oop value) {
406 _jvmci_reserved_oop0 = value;
407 }
408
409 oop get_jvmci_reserved_oop0() {
410 return _jvmci_reserved_oop0;
411 }
412
413 void set_jvmci_reserved0(jlong value) {
414 _jvmci_reserved0 = value;
415 }
416
417 jlong get_jvmci_reserved0() {
418 return _jvmci_reserved0;
419 }
420
421 void set_jvmci_reserved1(jlong value) {
422 _jvmci_reserved1 = value;
423 }
424
425 jlong get_jvmci_reserved1() {
426 return _jvmci_reserved1;
427 }
428
429 void set_live_nmethod(nmethod* nm) {
430 assert(_live_nmethod == nullptr, "only one");
431 _live_nmethod = nm;
432 }
433
434 void clear_live_nmethod() {
435 _live_nmethod = nullptr;
436 }
437
438 private:
439 #endif // INCLUDE_JVMCI
440
441 StackOverflow _stack_overflow_state;
442
443 void pretouch_stack();
444
445 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
446 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
447 // code)
448 volatile oop _exception_oop; // Exception thrown in compiled code
449 volatile address _exception_pc; // PC where exception happened
450 volatile address _exception_handler_pc; // PC for handler of exception
451 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
452
453 private:
454 // support for JNI critical regions
455 jint _jni_active_critical; // count of entries into JNI critical region
456
457 // Checked JNI: function name requires exception check
458 char* _pending_jni_exception_check_fn;
459
460 // For deadlock detection.
461 int _depth_first_number;
462
463 // JVMTI PopFrame support
464 // This is set to popframe_pending to signal that top Java frame should be popped immediately
465 int _popframe_condition;
466
467 // If reallocation of scalar replaced objects fails, we throw OOM
468 // and during exception propagation, pop the top
469 // _frames_to_pop_failed_realloc frames, the ones that reference
470 // failed reallocations.
471 int _frames_to_pop_failed_realloc;
472
473 ContinuationEntry* _cont_entry;
474 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub/upcall_stub/native_wrapper
475 // frame inside the continuation that we know about
476 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
477
478 // It's signed for error detection.
479 intx _held_monitor_count; // used by continuations for fast lock detection
480 intx _jni_monitor_count;
481 ObjectMonitor* _unlocked_inflated_monitor;
482
483 // This is the field we poke in the interpreter and native
484 // wrapper (Object.wait) to check for preemption.
485 address _preempt_alternate_return;
486 // When preempting on monitorenter we could have acquired the
487 // monitor after freezing all vthread frames. In that case we
488 // set this field so that in the preempt stub we call thaw again
489 // instead of unmounting.
490 bool _preemption_cancelled;
491 // For Object.wait() we set this field to know if we need to
492 // throw IE at the end of thawing before returning to Java.
493 bool _pending_interrupted_exception;
494
495 public:
496 bool preemption_cancelled() { return _preemption_cancelled; }
497 void set_preemption_cancelled(bool b) { _preemption_cancelled = b; }
498
499 bool pending_interrupted_exception() { return _pending_interrupted_exception; }
500 void set_pending_interrupted_exception(bool b) { _pending_interrupted_exception = b; }
501
502 bool preempting() { return _preempt_alternate_return != nullptr; }
503 void set_preempt_alternate_return(address val) { _preempt_alternate_return = val; }
504
505 private:
506
507 friend class VMThread;
508 friend class ThreadWaitTransition;
509 friend class VM_Exit;
510
511 // Stack watermark barriers.
512 StackWatermarks _stack_watermarks;
513
514 public:
515 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
516
517 public:
518 // Constructor
519 JavaThread(MemTag mem_tag = mtThread); // delegating constructor
520 JavaThread(ThreadFunction entry_point, size_t stack_size = 0, MemTag mem_tag = mtThread);
521 ~JavaThread();
522
523 // Factory method to create a new JavaThread whose attach state is "is attaching"
524 static JavaThread* create_attaching_thread();
525
526 #ifdef ASSERT
527 // verify this JavaThread hasn't be published in the Threads::list yet
528 void verify_not_published();
529 #endif // ASSERT
530
531 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
532
533 //JNI functiontable getter/setter for JVMTI jni function table interception API.
534 void set_jni_functions(struct JNINativeInterface_* functionTable) {
535 _jni_environment.functions = functionTable;
536 }
537 struct JNINativeInterface_* get_jni_functions() {
538 return (struct JNINativeInterface_ *)_jni_environment.functions;
539 }
540
541 // This function is called at thread creation to allow
542 // platform specific thread variables to be initialized.
543 void cache_global_variables();
544
545 // Executes Shutdown.shutdown()
546 void invoke_shutdown_hooks();
547
548 // Cleanup on thread exit
549 enum ExitType {
550 normal_exit,
551 jni_detach
552 };
553 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
554
555 void cleanup_failed_attach_current_thread(bool is_daemon);
556
557 // Testers
558 virtual bool is_Java_thread() const { return true; }
559 virtual bool can_call_java() const { return true; }
560
561 virtual bool is_active_Java_thread() const;
562
563 // Thread oop. threadObj() can be null for initial JavaThread
564 // (or for threads attached via JNI)
565 oop threadObj() const;
566 void set_threadOopHandles(oop p);
567 oop vthread() const;
568 void set_vthread(oop p);
569 oop scopedValueCache() const;
570 void set_scopedValueCache(oop p);
571 void clear_scopedValueBindings();
572 oop jvmti_vthread() const;
573 void set_jvmti_vthread(oop p);
574 oop vthread_or_thread() const;
575
576 // Prepare thread and add to priority queue. If a priority is
577 // not specified, use the priority of the thread object. Threads_lock
578 // must be held while this function is called.
579 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
580
581 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
582 address saved_exception_pc() { return _saved_exception_pc; }
583
584 ThreadFunction entry_point() const { return _entry_point; }
585
586 // Allocates a new Java level thread object for this thread. thread_name may be null.
587 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
588
589 // Last frame anchor routines
590
591 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
592
593 // last_Java_sp
594 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
595 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
596
597 // last_Java_pc
598
599 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
600
601 // Safepoint support
602 inline JavaThreadState thread_state() const;
603 inline void set_thread_state(JavaThreadState s);
604 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
605 inline ThreadSafepointState* safepoint_state() const;
606 inline void set_safepoint_state(ThreadSafepointState* state);
607 inline bool is_at_poll_safepoint();
608
609 // JavaThread termination and lifecycle support:
610 void smr_delete();
611 bool on_thread_list() const { return _on_thread_list; }
612 void set_on_thread_list() { _on_thread_list = true; }
613
614 // thread has called JavaThread::exit(), thread's GC barrier is detached
615 // or thread is terminated
616 bool is_exiting() const;
617 // thread's GC barrier is NOT detached and thread is NOT terminated
618 bool is_oop_safe() const;
619 // thread is terminated (no longer on the threads list); the thread must
620 // be protected by a ThreadsListHandle to avoid potential crashes.
621 bool check_is_terminated(TerminatedTypes l_terminated) const {
622 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
623 }
624 bool is_terminated() const;
625 void set_terminated(TerminatedTypes t);
626
627 void block_if_vm_exited();
628
629 bool doing_unsafe_access() { return _doing_unsafe_access; }
630 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
631
632 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
633 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
634
635 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
636
637 static ByteSize polling_word_offset() {
638 ByteSize offset = byte_offset_of(Thread, _poll_data) +
639 byte_offset_of(SafepointMechanism::ThreadData, _polling_word);
640 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
641 assert(in_bytes(offset) < 128, "Offset >= 128");
642 return offset;
643 }
644
645 static ByteSize polling_page_offset() {
646 ByteSize offset = byte_offset_of(Thread, _poll_data) +
647 byte_offset_of(SafepointMechanism::ThreadData, _polling_page);
648 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
649 assert(in_bytes(offset) < 128, "Offset >= 128");
650 return offset;
651 }
652
653 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
654
655 // Continuation support
656 ContinuationEntry* last_continuation() const { return _cont_entry; }
657 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
658 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
659 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
660 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
661 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
662 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
663
664 void inc_held_monitor_count(intx i = 1, bool jni = false);
665 void dec_held_monitor_count(intx i = 1, bool jni = false);
666
667 intx held_monitor_count() { return _held_monitor_count; }
668 intx jni_monitor_count() { return _jni_monitor_count; }
669 void clear_jni_monitor_count() { _jni_monitor_count = 0; }
670
671 // Support for SharedRuntime::monitor_exit_helper()
672 ObjectMonitor* unlocked_inflated_monitor() const { return _unlocked_inflated_monitor; }
673 void clear_unlocked_inflated_monitor() {
674 _unlocked_inflated_monitor = nullptr;
675 }
676
677 inline bool is_vthread_mounted() const;
678 inline const ContinuationEntry* vthread_continuation() const;
679
680 private:
681 DEBUG_ONLY(void verify_frame_info();)
682
683 // Support for thread handshake operations
684 HandshakeState _handshake;
685 public:
686 HandshakeState* handshake_state() { return &_handshake; }
687
688 // A JavaThread can always safely operate on it self and other threads
689 // can do it safely if they are the active handshaker.
690 bool is_handshake_safe_for(Thread* th) const {
691 return _handshake.active_handshaker() == th || this == th;
692 }
693
694 // Suspend/resume support for JavaThread
695 // higher-level suspension/resume logic called by the public APIs
696 bool java_suspend();
697 bool java_resume();
698 bool is_suspended() { return _handshake.is_suspended(); }
699
700 // Check for async exception in addition to safepoint.
701 static void check_special_condition_for_native_trans(JavaThread *thread);
702
703 // Synchronize with another thread that is deoptimizing objects of the
704 // current thread, i.e. reverts optimizations based on escape analysis.
705 void wait_for_object_deoptimization();
706
707 #if INCLUDE_JVMTI
708 inline void set_carrier_thread_suspended();
709 inline void clear_carrier_thread_suspended();
710
711 bool is_carrier_thread_suspended() const {
712 return _carrier_thread_suspended;
713 }
714
715 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
716 void set_is_in_VTMS_transition(bool val);
717
718 bool is_disable_suspend() const { return _is_disable_suspend; }
719 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
720
721 bool VTMS_transition_mark() const { return Atomic::load(&_VTMS_transition_mark); }
722 void set_VTMS_transition_mark(bool val) { Atomic::store(&_VTMS_transition_mark, val); }
723
724 // Temporarily skip posting JVMTI events for safety reasons when executions is in a critical section:
725 // - is in a VTMS transition (_is_in_VTMS_transition)
726 // - is in an interruptLock or similar critical section (_is_disable_suspend)
727 bool should_hide_jvmti_events() const { return _is_in_VTMS_transition || _is_disable_suspend; }
728
729 bool on_monitor_waited_event() { return _on_monitor_waited_event; }
730 void set_on_monitor_waited_event(bool val) { _on_monitor_waited_event = val; }
731
732 bool pending_contended_entered_event() { return _contended_entered_monitor != nullptr; }
733 ObjectMonitor* contended_entered_monitor() { return _contended_entered_monitor; }
734 #ifdef ASSERT
735 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
736 void set_is_VTMS_transition_disabler(bool val);
737 #endif
738 #endif
739
740 void set_contended_entered_monitor(ObjectMonitor* val) NOT_JVMTI_RETURN JVMTI_ONLY({ _contended_entered_monitor = val; })
741
742 // Support for object deoptimization and JFR suspension
743 void handle_special_runtime_exit_condition();
744 bool has_special_runtime_exit_condition() {
745 return (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
746 }
747
748 // Stack-locking support (not for LM_LIGHTWEIGHT)
749 bool is_lock_owned(address adr) const;
750
751 // Accessors for vframe array top
752 // The linked list of vframe arrays are sorted on sp. This means when we
753 // unpack the head must contain the vframe array to unpack.
754 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
755 vframeArray* vframe_array_head() const { return _vframe_array_head; }
756
757 // Side structure for deferring update of java frame locals until deopt occurs
758 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
759 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
760
761 // These only really exist to make debugging deopt problems simpler
762
763 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
764 vframeArray* vframe_array_last() const { return _vframe_array_last; }
765
766 // The special resourceMark used during deoptimization
767
768 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
769 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
770
771 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
772 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
773
774 Method* callee_target() const { return _callee_target; }
775 void set_callee_target (Method* x) { _callee_target = x; }
776
777 // Oop results of vm runtime calls
778 oop vm_result() const { return _vm_result; }
779 void set_vm_result (oop x) { _vm_result = x; }
780
781 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
782
783 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
784 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
785
786 // Is thread in scope of an InternalOOMEMark?
787 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
788 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
789
790 #if INCLUDE_JVMCI
791 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
792 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
793 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
794 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
795 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
796 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
797 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
798
799 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
800 void set_libjvmci_runtime(JVMCIRuntime* rt) {
801 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
802 _libjvmci_runtime = rt;
803 }
804 #endif // INCLUDE_JVMCI
805
806 // Exception handling for compiled methods
807 oop exception_oop() const;
808 address exception_pc() const { return _exception_pc; }
809
810 void set_exception_oop(oop o);
811 void set_exception_pc(address a) { _exception_pc = a; }
812 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
813 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
814
815 void clear_exception_oop_and_pc() {
816 set_exception_oop(nullptr);
817 set_exception_pc(nullptr);
818 }
819
820 // Check if address is in the usable part of the stack (excludes protected
821 // guard pages). Can be applied to any thread and is an approximation for
822 // using is_in_live_stack when the query has to happen from another thread.
823 bool is_in_usable_stack(address adr) const {
824 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
825 }
826
827 // Misc. accessors/mutators
828 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
829
830 // For assembly stub generation
831 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
832 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
833 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
834 static ByteSize pending_jni_exception_check_fn_offset() {
835 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
836 }
837 static ByteSize last_Java_sp_offset() {
838 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
839 }
840 static ByteSize last_Java_pc_offset() {
841 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
842 }
843 static ByteSize frame_anchor_offset() {
844 return byte_offset_of(JavaThread, _anchor);
845 }
846 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
847 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
848 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
849 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
850 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
851 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
852 #if INCLUDE_JVMCI
853 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
854 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
855 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
856 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
857 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
858 #endif // INCLUDE_JVMCI
859 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
860 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
861 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
862 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
863
864 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
865
866 // StackOverflow offsets
867 static ByteSize stack_overflow_limit_offset() {
868 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
869 }
870 static ByteSize stack_guard_state_offset() {
871 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
872 }
873 static ByteSize reserved_stack_activation_offset() {
874 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
875 }
876 static ByteSize shadow_zone_safe_limit() {
877 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
878 }
879 static ByteSize shadow_zone_growth_watermark() {
880 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
881 }
882
883 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
884
885 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
886 static ByteSize should_post_on_exceptions_flag_offset() {
887 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
888 }
889 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
890 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
891
892 static ByteSize monitor_owner_id_offset() { return byte_offset_of(JavaThread, _monitor_owner_id); }
893
894 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
895 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
896 static ByteSize held_monitor_count_offset() { return byte_offset_of(JavaThread, _held_monitor_count); }
897 static ByteSize jni_monitor_count_offset() { return byte_offset_of(JavaThread, _jni_monitor_count); }
898 static ByteSize preemption_cancelled_offset() { return byte_offset_of(JavaThread, _preemption_cancelled); }
899 static ByteSize preempt_alternate_return_offset() { return byte_offset_of(JavaThread, _preempt_alternate_return); }
900 static ByteSize unlocked_inflated_monitor_offset() { return byte_offset_of(JavaThread, _unlocked_inflated_monitor); }
901
902 #if INCLUDE_JVMTI
903 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); }
904 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
905 #endif
906
907 // Returns the jni environment for this thread
908 JNIEnv* jni_environment() { return &_jni_environment; }
909
910 // Returns the current thread as indicated by the given JNIEnv.
911 // We don't assert it is Thread::current here as that is done at the
912 // external JNI entry points where the JNIEnv is passed into the VM.
913 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
914 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
915 // We can't normally get here in a thread that has completed its
916 // execution and so "is_terminated", except when the call is from
917 // AsyncGetCallTrace, which can be triggered by a signal at any point in
918 // a thread's lifecycle. A thread is also considered terminated if the VM
919 // has exited, so we have to check this and block in case this is a daemon
920 // thread returning to the VM (the JNI DirectBuffer entry points rely on
921 // this).
922 if (current->is_terminated()) {
923 current->block_if_vm_exited();
924 }
925 return current;
926 }
927
928 // JNI critical regions. These can nest.
929 bool in_critical() { return _jni_active_critical > 0; }
930 bool in_last_critical() { return _jni_active_critical == 1; }
931 inline void enter_critical();
932 void exit_critical() {
933 assert(Thread::current() == this, "this must be current thread");
934 _jni_active_critical--;
935 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
936 }
937
938 // Checked JNI: is the programmer required to check for exceptions, if so specify
939 // which function name. Returning to a Java frame should implicitly clear the
940 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
941 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
942 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
943 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
944 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
945 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
946 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
947
948 // For deadlock detection
949 int depth_first_number() { return _depth_first_number; }
950 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
951
952 public:
953 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
954 void inc_in_deopt_handler() { _in_deopt_handler++; }
955 void dec_in_deopt_handler() {
956 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
957 if (_in_deopt_handler > 0) { // robustness
958 _in_deopt_handler--;
959 }
960 }
961
962 private:
963 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
964
965 // factor out low-level mechanics for use in both normal and error cases
966 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
967
968 public:
969
970 // Frame iteration; calls the function f for all frames on the stack
971 void frames_do(void f(frame*, const RegisterMap*));
972
973 // Memory operations
974 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
975 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
976
977 // GC operations
978 virtual void nmethods_do(NMethodClosure* cf);
979
980 // RedefineClasses Support
981 void metadata_do(MetadataClosure* f);
982
983 // Debug method asserting thread states are correct during a handshake operation.
984 DEBUG_ONLY(void verify_states_for_handshake();)
985
986 // Misc. operations
987 const char* name() const;
988 const char* name_raw() const;
989 const char* type_name() const { return "JavaThread"; }
990 static const char* name_for(oop thread_obj);
991
992 void print_on(outputStream* st, bool print_extended_info) const;
993 void print_on(outputStream* st) const { print_on(st, false); }
994 void print() const;
995 void print_thread_state_on(outputStream*) const;
996 void print_on_error(outputStream* st, char* buf, int buflen) const;
997 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
998 void verify();
999
1000 // Accessing frames
1001 frame last_frame() {
1002 _anchor.make_walkable();
1003 return pd_last_frame();
1004 }
1005 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
1006
1007 frame carrier_last_frame(RegisterMap* reg_map);
1008 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
1009
1010 frame vthread_last_frame();
1011 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
1012
1013 frame platform_thread_last_frame(RegisterMap* reg_map);
1014 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
1015 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
1016 }
1017
1018 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
1019
1020 // Returns method at 'depth' java or native frames down the stack
1021 // Used for security checks
1022 Klass* security_get_caller_class(int depth);
1023
1024 // Print stack trace in external format
1025 // These variants print carrier/platform thread information only.
1026 void print_stack_on(outputStream* st);
1027 void print_stack() { print_stack_on(tty); }
1028 // This prints the currently mounted virtual thread.
1029 void print_vthread_stack_on(outputStream* st);
1030 // This prints the active stack: either carrier/platform or virtual.
1031 void print_active_stack_on(outputStream* st);
1032 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1033 // This is the external format from above, but selecting the platform
1034 // or vthread as applicable.
1035 void print_jni_stack();
1036
1037 // Print stack traces in various internal formats
1038 void trace_stack() PRODUCT_RETURN;
1039 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1040 void trace_frames() PRODUCT_RETURN;
1041
1042 // Print an annotated view of the stack frames
1043 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1044 void validate_frame_layout() {
1045 print_frame_layout(0, true);
1046 }
1047
1048 // Function for testing deoptimization
1049 void deoptimize();
1050 void make_zombies();
1051
1052 void deoptimize_marked_methods();
1053
1054 public:
1055 // Returns the running thread as a JavaThread
1056 static JavaThread* current() {
1057 return JavaThread::cast(Thread::current());
1058 }
1059
1060 // Returns the current thread as a JavaThread, or nullptr if not attached
1061 static inline JavaThread* current_or_null();
1062
1063 // Casts
1064 static JavaThread* cast(Thread* t) {
1065 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
1066 return static_cast<JavaThread*>(t);
1067 }
1068
1069 static const JavaThread* cast(const Thread* t) {
1070 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1071 return static_cast<const JavaThread*>(t);
1072 }
1073
1074 // Returns the active Java thread. Do not use this if you know you are calling
1075 // from a JavaThread, as it's slower than JavaThread::current. If called from
1076 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1077 // operation. You may not want that either.
1078 static JavaThread* active();
1079
1080 protected:
1081 virtual void pre_run();
1082 virtual void run();
1083 void thread_main_inner();
1084 virtual void post_run();
1085
1086 public:
1087 // Thread local information maintained by JVMTI.
1088 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1089 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1090 // getter is used to get this JavaThread's JvmtiThreadState if it has
1091 // one which means null can be returned. JvmtiThreadState::state_for()
1092 // is used to get the specified JavaThread's JvmtiThreadState if it has
1093 // one or it allocates a new JvmtiThreadState for the JavaThread and
1094 // returns it. JvmtiThreadState::state_for() will return null only if
1095 // the specified JavaThread is exiting.
1096 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1097 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1098
1099 #if INCLUDE_JVMTI
1100 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1101 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1102 #endif
1103
1104 // JVMTI PopFrame support
1105 // Setting and clearing popframe_condition
1106 // All of these enumerated values are bits. popframe_pending
1107 // indicates that a PopFrame() has been requested and not yet been
1108 // completed. popframe_processing indicates that that PopFrame() is in
1109 // the process of being completed. popframe_force_deopt_reexecution_bit
1110 // indicates that special handling is required when returning to a
1111 // deoptimized caller.
1112 enum PopCondition {
1113 popframe_inactive = 0x00,
1114 popframe_pending_bit = 0x01,
1115 popframe_processing_bit = 0x02,
1116 popframe_force_deopt_reexecution_bit = 0x04
1117 };
1118 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1119 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1120 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1121 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1122 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1123 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1124 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1125
1126 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1127 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1128 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1129
1130 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1131 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1132 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1133
1134 private:
1135 // Saved incoming arguments to popped frame.
1136 // Used only when popped interpreted frame returns to deoptimized frame.
1137 void* _popframe_preserved_args;
1138 int _popframe_preserved_args_size;
1139
1140 public:
1141 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1142 void* popframe_preserved_args();
1143 ByteSize popframe_preserved_args_size();
1144 WordSize popframe_preserved_args_size_in_words();
1145 void popframe_free_preserved_args();
1146
1147
1148 private:
1149 JvmtiThreadState *_jvmti_thread_state;
1150
1151 // Used by the interpreter in fullspeed mode for frame pop, method
1152 // entry, method exit and single stepping support. This field is
1153 // only set to non-zero at a safepoint or using a direct handshake
1154 // (see EnterInterpOnlyModeClosure).
1155 // It can be set to zero asynchronously to this threads execution (i.e., without
1156 // safepoint/handshake or a lock) so we have to be very careful.
1157 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1158 int _interp_only_mode;
1159
1160 public:
1161 // used by the interpreter for fullspeed debugging support (see above)
1162 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1163 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1164 int get_interp_only_mode() { return _interp_only_mode; }
1165 int set_interp_only_mode(int val) { return _interp_only_mode = val; }
1166 void increment_interp_only_mode() { ++_interp_only_mode; }
1167 void decrement_interp_only_mode() { --_interp_only_mode; }
1168
1169 // support for cached flag that indicates whether exceptions need to be posted for this thread
1170 // if this is false, we can avoid deoptimizing when events are thrown
1171 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1172 private:
1173 int _should_post_on_exceptions_flag;
1174
1175 public:
1176 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1177
1178 private:
1179 ThreadStatistics *_thread_stat;
1180
1181 public:
1182 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1183
1184 // Return a blocker object for which this thread is blocked parking.
1185 oop current_park_blocker();
1186
1187 private:
1188 static size_t _stack_size_at_create;
1189
1190 public:
1191 static inline size_t stack_size_at_create(void) {
1192 return _stack_size_at_create;
1193 }
1194 static inline void set_stack_size_at_create(size_t value) {
1195 _stack_size_at_create = value;
1196 }
1197
1198 // Machine dependent stuff
1199 #include OS_CPU_HEADER(javaThread)
1200
1201 // JSR166 per-thread parker
1202 private:
1203 Parker _parker;
1204 public:
1205 Parker* parker() { return &_parker; }
1206
1207 public:
1208 // clearing/querying jni attach status
1209 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1210 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1211 inline void set_done_attaching_via_jni();
1212
1213 // Stack dump assistance:
1214 // Track the class we want to initialize but for which we have to wait
1215 // on its init_lock() because it is already being initialized.
1216 void set_class_to_be_initialized(InstanceKlass* k);
1217 InstanceKlass* class_to_be_initialized() const;
1218
1219 // Track executing class initializer, see ThreadInClassInitializer
1220 void set_class_being_initialized(InstanceKlass* k);
1221 InstanceKlass* class_being_initialized() const;
1222
1223 private:
1224 InstanceKlass* _class_to_be_initialized;
1225 InstanceKlass* _class_being_initialized;
1226
1227 // java.lang.Thread.sleep support
1228 ParkEvent * _SleepEvent;
1229
1230 #if INCLUDE_JFR
1231 // Support for jdk.VirtualThreadPinned event
1232 freeze_result _last_freeze_fail_result;
1233 Ticks _last_freeze_fail_time;
1234 #endif
1235
1236 public:
1237 bool sleep(jlong millis);
1238 bool sleep_nanos(jlong nanos);
1239
1240 // java.lang.Thread interruption support
1241 void interrupt();
1242 bool is_interrupted(bool clear_interrupted);
1243
1244 #if INCLUDE_JFR
1245 // Support for jdk.VirtualThreadPinned event
1246 freeze_result last_freeze_fail_result() { return _last_freeze_fail_result; }
1247 Ticks& last_freeze_fail_time() { return _last_freeze_fail_time; }
1248 void set_last_freeze_fail_result(freeze_result result);
1249 #endif
1250 void post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) NOT_JFR_RETURN();
1251
1252
1253 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1254 // the Java code in Object::wait which are not present in RawMonitorWait.
1255 bool get_and_clear_interrupted();
1256
1257 private:
1258 LockStack _lock_stack;
1259 OMCache _om_cache;
1260
1261 public:
1262 LockStack& lock_stack() { return _lock_stack; }
1263
1264 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1265 // Those offsets are used in code generators to access the LockStack that is embedded in this
1266 // JavaThread structure. Those accesses are relative to the current thread, which
1267 // is typically in a dedicated register.
1268 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1269 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1270
1271 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); }
1272 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); }
1273
1274 void om_set_monitor_cache(ObjectMonitor* monitor);
1275 void om_clear_monitor_cache();
1276 ObjectMonitor* om_get_from_monitor_cache(oop obj);
1277
1278 static OopStorage* thread_oop_storage();
1279
1280 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1281
1282 // Helper function to create the java.lang.Thread object for a
1283 // VM-internal thread. The thread will have the given name and be
1284 // part of the System ThreadGroup.
1285 static Handle create_system_thread_object(const char* name, TRAPS);
1286
1287 // Helper function to start a VM-internal daemon thread.
1288 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1289 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1290 Handle thread_oop, ThreadPriority prio);
1291
1292 // Helper function to do vm_exit_on_initialization for osthread
1293 // resource allocation failure.
1294 static void vm_exit_on_osthread_failure(JavaThread* thread);
1295
1296 // Deferred OopHandle release support
1297 private:
1298 // List of OopHandles to be released - guarded by the Service_lock.
1299 static OopHandleList* _oop_handle_list;
1300 // Add our OopHandles to the list for the service thread to release.
1301 void add_oop_handles_for_release();
1302 // Called by the ServiceThread to release the OopHandles.
1303 static void release_oop_handles();
1304 // Called by the ServiceThread to poll if there are any OopHandles to release.
1305 // Called when holding the Service_lock.
1306 static bool has_oop_handles_to_release() {
1307 return _oop_handle_list != nullptr;
1308 }
1309 };
1310
1311 inline JavaThread* JavaThread::current_or_null() {
1312 Thread* current = Thread::current_or_null();
1313 return current != nullptr ? JavaThread::cast(current) : nullptr;
1314 }
1315
1316 class UnlockFlagSaver {
1317 private:
1318 JavaThread* _thread;
1319 bool _do_not_unlock;
1320 public:
1321 UnlockFlagSaver(JavaThread* t) {
1322 _thread = t;
1323 _do_not_unlock = t->do_not_unlock_if_synchronized();
1324 t->set_do_not_unlock_if_synchronized(false);
1325 }
1326 ~UnlockFlagSaver() {
1327 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1328 }
1329 };
1330
1331 class JNIHandleMark : public StackObj {
1332 JavaThread* _thread;
1333 public:
1334 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1335 thread->push_jni_handle_block();
1336 }
1337 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1338 };
1339
1340 class NoPreemptMark {
1341 ContinuationEntry* _ce;
1342 bool _unpin;
1343 public:
1344 NoPreemptMark(JavaThread* thread) : _ce(thread->last_continuation()), _unpin(false) {
1345 if (_ce != nullptr) _unpin = _ce->pin();
1346 }
1347 ~NoPreemptMark() { if (_unpin) _ce->unpin(); }
1348 };
1349
1350 class ThreadOnMonitorWaitedEvent {
1351 JavaThread* _thread;
1352 public:
1353 ThreadOnMonitorWaitedEvent(JavaThread* thread) : _thread(thread) {
1354 JVMTI_ONLY(_thread->set_on_monitor_waited_event(true);)
1355 }
1356 ~ThreadOnMonitorWaitedEvent() { JVMTI_ONLY(_thread->set_on_monitor_waited_event(false);) }
1357 };
1358
1359 class ThreadInClassInitializer : public StackObj {
1360 JavaThread* _thread;
1361 InstanceKlass* _previous;
1362 public:
1363 ThreadInClassInitializer(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
1364 _previous = _thread->class_being_initialized();
1365 _thread->set_class_being_initialized(ik);
1366 }
1367 ~ThreadInClassInitializer() {
1368 _thread->set_class_being_initialized(_previous);
1369 }
1370 };
1371
1372 #endif // SHARE_RUNTIME_JAVATHREAD_HPP