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/frame.hpp"
34 #include "runtime/globals.hpp"
35 #include "runtime/handshake.hpp"
36 #include "runtime/javaFrameAnchor.hpp"
37 #include "runtime/lockStack.hpp"
38 #include "runtime/park.hpp"
39 #include "runtime/safepointMechanism.hpp"
40 #include "runtime/stackWatermarkSet.hpp"
41 #include "runtime/stackOverflow.hpp"
42 #include "runtime/thread.hpp"
43 #include "runtime/threadHeapSampler.hpp"
44 #include "runtime/threadStatisticalInfo.hpp"
45 #include "utilities/exceptions.hpp"
46 #include "utilities/globalDefinitions.hpp"
47 #include "utilities/macros.hpp"
48 #if INCLUDE_JFR
49 #include "jfr/support/jfrThreadExtension.hpp"
50 #endif
51
52 class AsyncExceptionHandshake;
53 class ContinuationEntry;
54 class DeoptResourceMark;
55 class InternalOOMEMark;
56 class JNIHandleBlock;
57 class JVMCIRuntime;
58
59 class JvmtiDeferredUpdates;
60 class JvmtiSampledObjectAllocEventCollector;
61 class JvmtiThreadState;
62
63 class Metadata;
64 class OopHandleList;
65 class OopStorage;
66 class OSThread;
67
68 class ThreadsList;
69 class ThreadSafepointState;
70 class ThreadStatistics;
71
72 class vframeArray;
73 class vframe;
74 class javaVFrame;
75
76 class JavaThread;
77 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
78
79 class JavaThread: public Thread {
80 friend class VMStructs;
81 friend class JVMCIVMStructs;
82 friend class WhiteBox;
83 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
84 friend class HandshakeState;
85 friend class Continuation;
86 friend class Threads;
87 friend class ServiceThread; // for deferred OopHandle release access
88 private:
89 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
90
91 // All references to Java objects managed via OopHandles. These
92 // have to be released by the ServiceThread after the JavaThread has
93 // terminated - see add_oop_handles_for_release().
94 OopHandle _threadObj; // The Java level thread object
95 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj
96 OopHandle _jvmti_vthread;
97 OopHandle _scopedValueCache;
98
99 static OopStorage* _thread_oop_storage;
100
101 #ifdef ASSERT
102 private:
103 int _java_call_counter;
104
105 public:
106 int java_call_counter() { return _java_call_counter; }
107 void inc_java_call_counter() { _java_call_counter++; }
108 void dec_java_call_counter() {
109 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
110 _java_call_counter--;
111 }
112 private: // restore original namespace restriction
113 #endif // ifdef ASSERT
114
115 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
116
117 ThreadFunction _entry_point;
118
119 JNIEnv _jni_environment;
120
121 // Deopt support
122 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
123
124 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
125 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
126 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
127 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
128 // will be carried out as soon as possible which, in most cases, is just before deoptimization of
129 // the frame, when control returns to it.
130 JvmtiDeferredUpdates* _jvmti_deferred_updates;
131
132 // Handshake value for fixing 6243940. We need a place for the i2c
133 // adapter to store the callee Method*. This value is NEVER live
134 // across a gc point so it does NOT have to be gc'd
135 // The handshake is open ended since we can't be certain that it will
136 // be nulled. This is because we rarely ever see the race and end up
137 // in handle_wrong_method which is the backend of the handshake. See
138 // code in i2c adapters and handle_wrong_method.
139
140 Method* _callee_target;
141
142 // Used to pass back results to the interpreter or generated code running Java code.
143 oop _vm_result; // oop result is GC-preserved
144 Metadata* _vm_result_2; // non-oop result
145
146 // See ReduceInitialCardMarks: this holds the precise space interval of
147 // the most recent slow path allocation for which compiled code has
148 // elided card-marks for performance along the fast-path.
149 MemRegion _deferred_card_mark;
150
151 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
152 bool _current_pending_monitor_is_from_java; // locking is from Java code
153 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
154
155 // Active_handles points to a block of handles
156 JNIHandleBlock* _active_handles;
157
158 // One-element thread local free list
159 JNIHandleBlock* _free_handle_block;
160
161 public:
162 // For tracking the heavyweight monitor the thread is pending on.
163 ObjectMonitor* current_pending_monitor() {
164 // Use Atomic::load() to prevent data race between concurrent modification and
165 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
166 // Especially, reloading pointer from thread after null check must be prevented.
167 return Atomic::load(&_current_pending_monitor);
168 }
169 void set_current_pending_monitor(ObjectMonitor* monitor) {
170 Atomic::store(&_current_pending_monitor, monitor);
171 }
172 void set_current_pending_monitor_is_from_java(bool from_java) {
173 _current_pending_monitor_is_from_java = from_java;
174 }
175 bool current_pending_monitor_is_from_java() {
176 return _current_pending_monitor_is_from_java;
177 }
178 ObjectMonitor* current_waiting_monitor() {
179 // See the comment in current_pending_monitor() above.
180 return Atomic::load(&_current_waiting_monitor);
181 }
182 void set_current_waiting_monitor(ObjectMonitor* monitor) {
183 Atomic::store(&_current_waiting_monitor, monitor);
184 }
185
186 // JNI handle support
187 JNIHandleBlock* active_handles() const { return _active_handles; }
188 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
189 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
190 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
191
192 void push_jni_handle_block();
193 void pop_jni_handle_block();
194
195 private:
196 enum SuspendFlags {
197 // NOTE: avoid using the sign-bit as cc generates different test code
198 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
199 _trace_flag = 0x00000004U, // call tracing backend
200 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
201 };
202
203 // various suspension related flags - atomically updated
204 volatile uint32_t _suspend_flags;
205
206 inline void set_suspend_flag(SuspendFlags f);
207 inline void clear_suspend_flag(SuspendFlags f);
208
209 public:
210 inline void set_trace_flag();
211 inline void clear_trace_flag();
212 inline void set_obj_deopt_flag();
213 inline void clear_obj_deopt_flag();
214 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
215 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
216
217 // Asynchronous exception support
218 private:
219 friend class InstallAsyncExceptionHandshake;
220 friend class AsyncExceptionHandshake;
221 friend class HandshakeState;
222
223 void handle_async_exception(oop java_throwable);
224 public:
225 void install_async_exception(AsyncExceptionHandshake* aec = nullptr);
226 bool has_async_exception_condition();
227 inline void set_pending_unsafe_access_error();
228 static void send_async_exception(JavaThread* jt, oop java_throwable);
229
230 class NoAsyncExceptionDeliveryMark : public StackObj {
231 friend JavaThread;
232 JavaThread *_target;
233 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
234 inline ~NoAsyncExceptionDeliveryMark();
235 };
236
237 // Safepoint support
238 public: // Expose _thread_state for SafeFetchInt()
239 volatile JavaThreadState _thread_state;
240 private:
241 SafepointMechanism::ThreadData _poll_data;
242 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
243 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
244 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
245 #ifdef ASSERT
246 // Debug support for checking if code allows safepoints or not.
247 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
248 // mutex, or blocking on an object synchronizer (Java locking).
249 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
250 // the above cases. The class NoSafepointVerifier is used to set this counter.
251 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
252
253 public:
254 void inc_no_safepoint_count() { _no_safepoint_count++; }
255 void dec_no_safepoint_count() { _no_safepoint_count--; }
256 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
257 #endif // ASSERT
258 public:
259 // These functions check conditions before possibly going to a safepoint.
260 // including NoSafepointVerifier.
261 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
262 void check_possible_safepoint() NOT_DEBUG_RETURN;
263
264 #ifdef ASSERT
265 private:
266 volatile uint64_t _visited_for_critical_count;
267
268 public:
269 void set_visited_for_critical_count(uint64_t safepoint_id) {
270 assert(_visited_for_critical_count == 0, "Must be reset before set");
271 assert((safepoint_id & 0x1) == 1, "Must be odd");
272 _visited_for_critical_count = safepoint_id;
273 }
274 void reset_visited_for_critical_count(uint64_t safepoint_id) {
275 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
276 _visited_for_critical_count = 0;
277 }
278 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
279 return _visited_for_critical_count == safepoint_id;
280 }
281 #endif // ASSERT
282
283 // JavaThread termination support
284 public:
285 enum TerminatedTypes {
286 _not_terminated = 0xDEAD - 3,
287 _thread_exiting, // JavaThread::exit() has been called for this thread
288 _thread_gc_barrier_detached, // thread's GC barrier has been detached
289 _thread_terminated, // JavaThread is removed from thread list
290 _vm_exited // JavaThread is still executing native code, but VM is terminated
291 // only VM_Exit can set _vm_exited
292 };
293
294 private:
295 // In general a JavaThread's _terminated field transitions as follows:
296 //
297 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
298 //
299 // _vm_exited is a special value to cover the case of a JavaThread
300 // executing native code after the VM itself is terminated.
301 //
302 // A JavaThread that fails to JNI attach has these _terminated field transitions:
303 // _not_terminated => _thread_terminated
304 //
305 volatile TerminatedTypes _terminated;
306
307 jint _in_deopt_handler; // count of deoptimization
308 // handlers thread is in
309 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
310 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
311 // never locked) when throwing an exception. Used by interpreter only.
312 #if INCLUDE_JVMTI
313 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
314 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
315 bool _is_in_tmp_VTMS_transition; // thread is in temporary virtual thread mount state transition
316 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
317 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers
318 #ifdef ASSERT
319 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
320 #endif
321 #endif
322
323 // JNI attach states:
324 enum JNIAttachStates {
325 _not_attaching_via_jni = 1, // thread is not attaching via JNI
326 _attaching_via_jni, // thread is attaching via JNI
327 _attached_via_jni // thread has attached via JNI
328 };
329
330 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
331 // A native thread that is attaching via JNI starts with a value
332 // of _attaching_via_jni and transitions to _attached_via_jni.
333 volatile JNIAttachStates _jni_attach_state;
334
335 // In scope of an InternalOOMEMark?
336 bool _is_in_internal_oome_mark;
337
338 #if INCLUDE_JVMCI
339 // The _pending_* fields below are used to communicate extra information
340 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
341
342 // Communicates the DeoptReason and DeoptAction of the uncommon trap
343 int _pending_deoptimization;
344
345 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
346 // before the monitor has been acquired.
347 bool _pending_monitorenter;
348
349 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
350 bool _pending_transfer_to_interpreter;
351
352 // An id of a speculation that JVMCI compiled code can use to further describe and
353 // uniquely identify the speculative optimization guarded by an uncommon trap.
354 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
355 jlong _pending_failed_speculation;
356
357 // These fields are mutually exclusive in terms of live ranges.
358 union {
359 // Communicates the pc at which the most recent implicit exception occurred
360 // from the signal handler to a deoptimization stub.
361 address _implicit_exception_pc;
362
363 // Communicates an alternative call target to an i2c stub from a JavaCall .
364 address _alternate_call_target;
365 } _jvmci;
366
367 // The JVMCIRuntime in a JVMCI shared library
368 JVMCIRuntime* _libjvmci_runtime;
369
370 // Support for high precision, thread sensitive counters in JVMCI compiled code.
371 jlong* _jvmci_counters;
372
373 // Fast thread locals for use by JVMCI
374 jlong _jvmci_reserved0;
375 jlong _jvmci_reserved1;
376 oop _jvmci_reserved_oop0;
377
378 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
379 // be kept alive
380 nmethod* _live_nmethod;
381
382 public:
383 static jlong* _jvmci_old_thread_counters;
384 static void collect_counters(jlong* array, int length);
385
386 bool resize_counters(int current_size, int new_size);
387
388 static bool resize_all_jvmci_counters(int new_size);
389
390 void set_jvmci_reserved_oop0(oop value) {
391 _jvmci_reserved_oop0 = value;
392 }
393
394 oop get_jvmci_reserved_oop0() {
395 return _jvmci_reserved_oop0;
396 }
397
398 void set_jvmci_reserved0(jlong value) {
399 _jvmci_reserved0 = value;
400 }
401
402 jlong get_jvmci_reserved0() {
403 return _jvmci_reserved0;
404 }
405
406 void set_jvmci_reserved1(jlong value) {
407 _jvmci_reserved1 = value;
408 }
409
410 jlong get_jvmci_reserved1() {
411 return _jvmci_reserved1;
412 }
413
414 void set_live_nmethod(nmethod* nm) {
415 assert(_live_nmethod == nullptr, "only one");
416 _live_nmethod = nm;
417 }
418
419 void clear_live_nmethod() {
420 _live_nmethod = nullptr;
421 }
422
423 private:
424 #endif // INCLUDE_JVMCI
425
426 StackOverflow _stack_overflow_state;
427
428 void pretouch_stack();
429
430 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
431 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
432 // code)
433 volatile oop _exception_oop; // Exception thrown in compiled code
434 volatile address _exception_pc; // PC where exception happened
435 volatile address _exception_handler_pc; // PC for handler of exception
436 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
437
438 private:
439 // support for JNI critical regions
440 jint _jni_active_critical; // count of entries into JNI critical region
441
442 // Checked JNI: function name requires exception check
443 char* _pending_jni_exception_check_fn;
444
445 // For deadlock detection.
446 int _depth_first_number;
447
448 // JVMTI PopFrame support
449 // This is set to popframe_pending to signal that top Java frame should be popped immediately
450 int _popframe_condition;
451
452 // If reallocation of scalar replaced objects fails, we throw OOM
453 // and during exception propagation, pop the top
454 // _frames_to_pop_failed_realloc frames, the ones that reference
455 // failed reallocations.
456 int _frames_to_pop_failed_realloc;
457
458 ContinuationEntry* _cont_entry;
459 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub frame inside the
460 // continuation that we know about
461 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
462
463 // It's signed for error detection.
464 intx _held_monitor_count; // used by continuations for fast lock detection
465 intx _jni_monitor_count;
466
467 private:
468
469 friend class VMThread;
470 friend class ThreadWaitTransition;
471 friend class VM_Exit;
472
473 // Stack watermark barriers.
474 StackWatermarks _stack_watermarks;
475
476 public:
477 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
478
479 public:
480 // Constructor
481 JavaThread(); // delegating constructor
482 JavaThread(bool is_attaching_via_jni); // for main thread and JNI attached threads
483 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
484 ~JavaThread();
485
486 #ifdef ASSERT
487 // verify this JavaThread hasn't be published in the Threads::list yet
488 void verify_not_published();
489 #endif // ASSERT
490
491 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
492
493 //JNI functiontable getter/setter for JVMTI jni function table interception API.
494 void set_jni_functions(struct JNINativeInterface_* functionTable) {
495 _jni_environment.functions = functionTable;
496 }
497 struct JNINativeInterface_* get_jni_functions() {
498 return (struct JNINativeInterface_ *)_jni_environment.functions;
499 }
500
501 // This function is called at thread creation to allow
502 // platform specific thread variables to be initialized.
503 void cache_global_variables();
504
505 // Executes Shutdown.shutdown()
506 void invoke_shutdown_hooks();
507
508 // Cleanup on thread exit
509 enum ExitType {
510 normal_exit,
511 jni_detach
512 };
513 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
514
515 void cleanup_failed_attach_current_thread(bool is_daemon);
516
517 // Testers
518 virtual bool is_Java_thread() const { return true; }
519 virtual bool can_call_java() const { return true; }
520
521 virtual bool is_active_Java_thread() const;
522
523 // Thread oop. threadObj() can be null for initial JavaThread
524 // (or for threads attached via JNI)
525 oop threadObj() const;
526 void set_threadOopHandles(oop p);
527 oop vthread() const;
528 void set_vthread(oop p);
529 oop scopedValueCache() const;
530 void set_scopedValueCache(oop p);
531 void clear_scopedValueBindings();
532 oop jvmti_vthread() const;
533 void set_jvmti_vthread(oop p);
534 oop vthread_or_thread() const;
535
536 // Prepare thread and add to priority queue. If a priority is
537 // not specified, use the priority of the thread object. Threads_lock
538 // must be held while this function is called.
539 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
540
541 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
542 address saved_exception_pc() { return _saved_exception_pc; }
543
544 ThreadFunction entry_point() const { return _entry_point; }
545
546 // Allocates a new Java level thread object for this thread. thread_name may be null.
547 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
548
549 // Last frame anchor routines
550
551 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
552
553 // last_Java_sp
554 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
555 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
556
557 // last_Java_pc
558
559 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
560
561 // Safepoint support
562 inline JavaThreadState thread_state() const;
563 inline void set_thread_state(JavaThreadState s);
564 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
565 inline ThreadSafepointState* safepoint_state() const;
566 inline void set_safepoint_state(ThreadSafepointState* state);
567 inline bool is_at_poll_safepoint();
568
569 // JavaThread termination and lifecycle support:
570 void smr_delete();
571 bool on_thread_list() const { return _on_thread_list; }
572 void set_on_thread_list() { _on_thread_list = true; }
573
574 // thread has called JavaThread::exit(), thread's GC barrier is detached
575 // or thread is terminated
576 bool is_exiting() const;
577 // thread's GC barrier is NOT detached and thread is NOT terminated
578 bool is_oop_safe() const;
579 // thread is terminated (no longer on the threads list); the thread must
580 // be protected by a ThreadsListHandle to avoid potential crashes.
581 bool check_is_terminated(TerminatedTypes l_terminated) const {
582 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
583 }
584 bool is_terminated() const;
585 void set_terminated(TerminatedTypes t);
586
587 void block_if_vm_exited();
588
589 bool doing_unsafe_access() { return _doing_unsafe_access; }
590 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
591
592 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
593 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
594
595 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
596
597 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
598
599 // Continuation support
600 ContinuationEntry* last_continuation() const { return _cont_entry; }
601 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
602 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
603 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
604 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
605 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
606 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
607
608 void inc_held_monitor_count(intx i = 1, bool jni = false);
609 void dec_held_monitor_count(intx i = 1, bool jni = false);
610
611 intx held_monitor_count() { return _held_monitor_count; }
612 intx jni_monitor_count() { return _jni_monitor_count; }
613 void clear_jni_monitor_count() { _jni_monitor_count = 0; }
614
615 inline bool is_vthread_mounted() const;
616 inline const ContinuationEntry* vthread_continuation() const;
617
618 private:
619 DEBUG_ONLY(void verify_frame_info();)
620
621 // Support for thread handshake operations
622 HandshakeState _handshake;
623 public:
624 HandshakeState* handshake_state() { return &_handshake; }
625
626 // A JavaThread can always safely operate on it self and other threads
627 // can do it safely if they are the active handshaker.
628 bool is_handshake_safe_for(Thread* th) const {
629 return _handshake.active_handshaker() == th || this == th;
630 }
631
632 // Suspend/resume support for JavaThread
633 // higher-level suspension/resume logic called by the public APIs
634 bool java_suspend();
635 bool java_resume();
636 bool is_suspended() { return _handshake.is_suspended(); }
637
638 // Check for async exception in addition to safepoint.
639 static void check_special_condition_for_native_trans(JavaThread *thread);
640
641 // Synchronize with another thread that is deoptimizing objects of the
642 // current thread, i.e. reverts optimizations based on escape analysis.
643 void wait_for_object_deoptimization();
644
645 #if INCLUDE_JVMTI
646 inline void set_carrier_thread_suspended();
647 inline void clear_carrier_thread_suspended();
648
649 bool is_carrier_thread_suspended() const {
650 return _carrier_thread_suspended;
651 }
652
653 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
654 bool is_in_tmp_VTMS_transition() const { return _is_in_tmp_VTMS_transition; }
655 bool is_in_any_VTMS_transition() const { return _is_in_VTMS_transition || _is_in_tmp_VTMS_transition; }
656
657 void set_is_in_VTMS_transition(bool val);
658 void toggle_is_in_tmp_VTMS_transition() { _is_in_tmp_VTMS_transition = !_is_in_tmp_VTMS_transition; };
659
660 bool is_disable_suspend() const { return _is_disable_suspend; }
661 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
662
663 bool VTMS_transition_mark() const { return Atomic::load(&_VTMS_transition_mark); }
664 void set_VTMS_transition_mark(bool val) { Atomic::store(&_VTMS_transition_mark, val); }
665
666 #ifdef ASSERT
667 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
668 void set_is_VTMS_transition_disabler(bool val);
669 #endif
670 #endif
671
672 // Support for object deoptimization and JFR suspension
673 void handle_special_runtime_exit_condition();
674 bool has_special_runtime_exit_condition() {
675 return (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
676 }
677
678 // Stack-locking support (not for LM_LIGHTWEIGHT)
679 bool is_lock_owned(address adr) const;
680
681 // Accessors for vframe array top
682 // The linked list of vframe arrays are sorted on sp. This means when we
683 // unpack the head must contain the vframe array to unpack.
684 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
685 vframeArray* vframe_array_head() const { return _vframe_array_head; }
686
687 // Side structure for deferring update of java frame locals until deopt occurs
688 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
689 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
690
691 // These only really exist to make debugging deopt problems simpler
692
693 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
694 vframeArray* vframe_array_last() const { return _vframe_array_last; }
695
696 // The special resourceMark used during deoptimization
697
698 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
699 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
700
701 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
702 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
703
704 Method* callee_target() const { return _callee_target; }
705 void set_callee_target (Method* x) { _callee_target = x; }
706
707 // Oop results of vm runtime calls
708 oop vm_result() const { return _vm_result; }
709 void set_vm_result (oop x) { _vm_result = x; }
710
711 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
712
713 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
714 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
715
716 // Is thread in scope of an InternalOOMEMark?
717 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
718 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
719
720 #if INCLUDE_JVMCI
721 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
722 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
723 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
724 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
725 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
726 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
727 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
728
729 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
730 void set_libjvmci_runtime(JVMCIRuntime* rt) {
731 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
732 _libjvmci_runtime = rt;
733 }
734 #endif // INCLUDE_JVMCI
735
736 // Exception handling for compiled methods
737 oop exception_oop() const;
738 address exception_pc() const { return _exception_pc; }
739
740 void set_exception_oop(oop o);
741 void set_exception_pc(address a) { _exception_pc = a; }
742 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
743 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
744
745 void clear_exception_oop_and_pc() {
746 set_exception_oop(nullptr);
747 set_exception_pc(nullptr);
748 }
749
750 // Check if address is in the usable part of the stack (excludes protected
751 // guard pages). Can be applied to any thread and is an approximation for
752 // using is_in_live_stack when the query has to happen from another thread.
753 bool is_in_usable_stack(address adr) const {
754 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
755 }
756
757 // Misc. accessors/mutators
758 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
759
760 // For assembly stub generation
761 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
762 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
763 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
764 static ByteSize pending_jni_exception_check_fn_offset() {
765 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
766 }
767 static ByteSize last_Java_sp_offset() {
768 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
769 }
770 static ByteSize last_Java_pc_offset() {
771 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
772 }
773 static ByteSize frame_anchor_offset() {
774 return byte_offset_of(JavaThread, _anchor);
775 }
776 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
777 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
778 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
779 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
780 static ByteSize polling_word_offset() { return byte_offset_of(JavaThread, _poll_data) + byte_offset_of(SafepointMechanism::ThreadData, _polling_word);}
781 static ByteSize polling_page_offset() { return byte_offset_of(JavaThread, _poll_data) + byte_offset_of(SafepointMechanism::ThreadData, _polling_page);}
782 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
783 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
784 #if INCLUDE_JVMCI
785 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
786 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
787 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
788 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
789 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
790 #endif // INCLUDE_JVMCI
791 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
792 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
793 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
794 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
795
796 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
797
798 // StackOverflow offsets
799 static ByteSize stack_overflow_limit_offset() {
800 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
801 }
802 static ByteSize stack_guard_state_offset() {
803 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
804 }
805 static ByteSize reserved_stack_activation_offset() {
806 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
807 }
808 static ByteSize shadow_zone_safe_limit() {
809 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
810 }
811 static ByteSize shadow_zone_growth_watermark() {
812 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
813 }
814
815 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
816
817 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
818 static ByteSize should_post_on_exceptions_flag_offset() {
819 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
820 }
821 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
822 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
823
824 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
825 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
826 static ByteSize held_monitor_count_offset() { return byte_offset_of(JavaThread, _held_monitor_count); }
827 static ByteSize jni_monitor_count_offset() { return byte_offset_of(JavaThread, _jni_monitor_count); }
828
829 #if INCLUDE_JVMTI
830 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); }
831 static ByteSize is_in_tmp_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_tmp_VTMS_transition); }
832 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
833 #endif
834
835 // Returns the jni environment for this thread
836 JNIEnv* jni_environment() { return &_jni_environment; }
837
838 // Returns the current thread as indicated by the given JNIEnv.
839 // We don't assert it is Thread::current here as that is done at the
840 // external JNI entry points where the JNIEnv is passed into the VM.
841 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
842 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
843 // We can't normally get here in a thread that has completed its
844 // execution and so "is_terminated", except when the call is from
845 // AsyncGetCallTrace, which can be triggered by a signal at any point in
846 // a thread's lifecycle. A thread is also considered terminated if the VM
847 // has exited, so we have to check this and block in case this is a daemon
848 // thread returning to the VM (the JNI DirectBuffer entry points rely on
849 // this).
850 if (current->is_terminated()) {
851 current->block_if_vm_exited();
852 }
853 return current;
854 }
855
856 // JNI critical regions. These can nest.
857 bool in_critical() { return _jni_active_critical > 0; }
858 bool in_last_critical() { return _jni_active_critical == 1; }
859 inline void enter_critical();
860 void exit_critical() {
861 assert(Thread::current() == this, "this must be current thread");
862 _jni_active_critical--;
863 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
864 }
865
866 // Checked JNI: is the programmer required to check for exceptions, if so specify
867 // which function name. Returning to a Java frame should implicitly clear the
868 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
869 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
870 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
871 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
872 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
873 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
874 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
875
876 // For deadlock detection
877 int depth_first_number() { return _depth_first_number; }
878 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
879
880 public:
881 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
882 void inc_in_deopt_handler() { _in_deopt_handler++; }
883 void dec_in_deopt_handler() {
884 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
885 if (_in_deopt_handler > 0) { // robustness
886 _in_deopt_handler--;
887 }
888 }
889
890 private:
891 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
892
893 // factor out low-level mechanics for use in both normal and error cases
894 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
895
896 public:
897
898 // Frame iteration; calls the function f for all frames on the stack
899 void frames_do(void f(frame*, const RegisterMap*));
900
901 // Memory operations
902 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
903 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
904
905 // GC operations
906 virtual void nmethods_do(NMethodClosure* cf);
907
908 // RedefineClasses Support
909 void metadata_do(MetadataClosure* f);
910
911 // Debug method asserting thread states are correct during a handshake operation.
912 DEBUG_ONLY(void verify_states_for_handshake();)
913
914 // Misc. operations
915 const char* name() const;
916 const char* name_raw() const;
917 const char* type_name() const { return "JavaThread"; }
918 static const char* name_for(oop thread_obj);
919
920 void print_on(outputStream* st, bool print_extended_info) const;
921 void print_on(outputStream* st) const { print_on(st, false); }
922 void print() const;
923 void print_thread_state_on(outputStream*) const;
924 void print_on_error(outputStream* st, char* buf, int buflen) const;
925 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
926 void verify();
927
928 // Accessing frames
929 frame last_frame() {
930 _anchor.make_walkable();
931 return pd_last_frame();
932 }
933 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
934
935 frame carrier_last_frame(RegisterMap* reg_map);
936 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
937
938 frame vthread_last_frame();
939 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
940
941 frame platform_thread_last_frame(RegisterMap* reg_map);
942 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
943 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
944 }
945
946 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
947
948 // Returns method at 'depth' java or native frames down the stack
949 // Used for security checks
950 Klass* security_get_caller_class(int depth);
951
952 // Print stack trace in external format
953 // These variants print carrier/platform thread information only.
954 void print_stack_on(outputStream* st);
955 void print_stack() { print_stack_on(tty); }
956 // This prints the currently mounted virtual thread.
957 void print_vthread_stack_on(outputStream* st);
958 // This prints the active stack: either carrier/platform or virtual.
959 void print_active_stack_on(outputStream* st);
960 // Print current stack trace for checked JNI warnings and JNI fatal errors.
961 // This is the external format from above, but selecting the platform
962 // or vthread as applicable.
963 void print_jni_stack();
964
965 // Print stack traces in various internal formats
966 void trace_stack() PRODUCT_RETURN;
967 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
968 void trace_frames() PRODUCT_RETURN;
969
970 // Print an annotated view of the stack frames
971 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
972 void validate_frame_layout() {
973 print_frame_layout(0, true);
974 }
975
976 // Function for testing deoptimization
977 void deoptimize();
978 void make_zombies();
979
980 void deoptimize_marked_methods();
981
982 public:
983 // Returns the running thread as a JavaThread
984 static JavaThread* current() {
985 return JavaThread::cast(Thread::current());
986 }
987
988 // Returns the current thread as a JavaThread, or nullptr if not attached
989 static inline JavaThread* current_or_null();
990
991 // Casts
992 static JavaThread* cast(Thread* t) {
993 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
994 return static_cast<JavaThread*>(t);
995 }
996
997 static const JavaThread* cast(const Thread* t) {
998 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
999 return static_cast<const JavaThread*>(t);
1000 }
1001
1002 // Returns the active Java thread. Do not use this if you know you are calling
1003 // from a JavaThread, as it's slower than JavaThread::current. If called from
1004 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1005 // operation. You may not want that either.
1006 static JavaThread* active();
1007
1008 protected:
1009 virtual void pre_run();
1010 virtual void run();
1011 void thread_main_inner();
1012 virtual void post_run();
1013
1014 public:
1015 // Thread local information maintained by JVMTI.
1016 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1017 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1018 // getter is used to get this JavaThread's JvmtiThreadState if it has
1019 // one which means null can be returned. JvmtiThreadState::state_for()
1020 // is used to get the specified JavaThread's JvmtiThreadState if it has
1021 // one or it allocates a new JvmtiThreadState for the JavaThread and
1022 // returns it. JvmtiThreadState::state_for() will return null only if
1023 // the specified JavaThread is exiting.
1024 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1025 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1026
1027 #if INCLUDE_JVMTI
1028 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1029 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1030 #endif
1031
1032 // JVMTI PopFrame support
1033 // Setting and clearing popframe_condition
1034 // All of these enumerated values are bits. popframe_pending
1035 // indicates that a PopFrame() has been requested and not yet been
1036 // completed. popframe_processing indicates that that PopFrame() is in
1037 // the process of being completed. popframe_force_deopt_reexecution_bit
1038 // indicates that special handling is required when returning to a
1039 // deoptimized caller.
1040 enum PopCondition {
1041 popframe_inactive = 0x00,
1042 popframe_pending_bit = 0x01,
1043 popframe_processing_bit = 0x02,
1044 popframe_force_deopt_reexecution_bit = 0x04
1045 };
1046 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1047 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1048 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1049 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1050 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1051 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1052 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1053
1054 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1055 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1056 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1057
1058 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1059 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1060 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1061
1062 private:
1063 // Saved incoming arguments to popped frame.
1064 // Used only when popped interpreted frame returns to deoptimized frame.
1065 void* _popframe_preserved_args;
1066 int _popframe_preserved_args_size;
1067
1068 public:
1069 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1070 void* popframe_preserved_args();
1071 ByteSize popframe_preserved_args_size();
1072 WordSize popframe_preserved_args_size_in_words();
1073 void popframe_free_preserved_args();
1074
1075
1076 private:
1077 JvmtiThreadState *_jvmti_thread_state;
1078
1079 // Used by the interpreter in fullspeed mode for frame pop, method
1080 // entry, method exit and single stepping support. This field is
1081 // only set to non-zero at a safepoint or using a direct handshake
1082 // (see EnterInterpOnlyModeClosure).
1083 // It can be set to zero asynchronously to this threads execution (i.e., without
1084 // safepoint/handshake or a lock) so we have to be very careful.
1085 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1086 int _interp_only_mode;
1087
1088 public:
1089 // used by the interpreter for fullspeed debugging support (see above)
1090 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1091 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1092 int get_interp_only_mode() { return _interp_only_mode; }
1093 int set_interp_only_mode(int val) { return _interp_only_mode = val; }
1094 void increment_interp_only_mode() { ++_interp_only_mode; }
1095 void decrement_interp_only_mode() { --_interp_only_mode; }
1096
1097 // support for cached flag that indicates whether exceptions need to be posted for this thread
1098 // if this is false, we can avoid deoptimizing when events are thrown
1099 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1100 private:
1101 int _should_post_on_exceptions_flag;
1102
1103 public:
1104 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1105
1106 private:
1107 ThreadStatistics *_thread_stat;
1108
1109 public:
1110 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1111
1112 // Return a blocker object for which this thread is blocked parking.
1113 oop current_park_blocker();
1114
1115 private:
1116 static size_t _stack_size_at_create;
1117
1118 public:
1119 static inline size_t stack_size_at_create(void) {
1120 return _stack_size_at_create;
1121 }
1122 static inline void set_stack_size_at_create(size_t value) {
1123 _stack_size_at_create = value;
1124 }
1125
1126 // Machine dependent stuff
1127 #include OS_CPU_HEADER(javaThread)
1128
1129 // JSR166 per-thread parker
1130 private:
1131 Parker _parker;
1132 public:
1133 Parker* parker() { return &_parker; }
1134
1135 public:
1136 // clearing/querying jni attach status
1137 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1138 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1139 inline void set_done_attaching_via_jni();
1140
1141 // Stack dump assistance:
1142 // Track the class we want to initialize but for which we have to wait
1143 // on its init_lock() because it is already being initialized.
1144 void set_class_to_be_initialized(InstanceKlass* k);
1145 InstanceKlass* class_to_be_initialized() const;
1146
1147 private:
1148 InstanceKlass* _class_to_be_initialized;
1149
1150 // java.lang.Thread.sleep support
1151 ParkEvent * _SleepEvent;
1152 public:
1153 bool sleep(jlong millis);
1154 bool sleep_nanos(jlong nanos);
1155
1156 // java.lang.Thread interruption support
1157 void interrupt();
1158 bool is_interrupted(bool clear_interrupted);
1159
1160 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1161 // the Java code in Object::wait which are not present in RawMonitorWait.
1162 bool get_and_clear_interrupted();
1163
1164 private:
1165 LockStack _lock_stack;
1166
1167 public:
1168 LockStack& lock_stack() { return _lock_stack; }
1169
1170 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1171 // Those offsets are used in code generators to access the LockStack that is embedded in this
1172 // JavaThread structure. Those accesses are relative to the current thread, which
1173 // is typically in a dedicated register.
1174 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1175 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1176
1177 static OopStorage* thread_oop_storage();
1178
1179 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1180
1181 // Helper function to create the java.lang.Thread object for a
1182 // VM-internal thread. The thread will have the given name and be
1183 // part of the System ThreadGroup.
1184 static Handle create_system_thread_object(const char* name, TRAPS);
1185
1186 // Helper function to start a VM-internal daemon thread.
1187 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1188 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1189 Handle thread_oop, ThreadPriority prio);
1190
1191 // Helper function to do vm_exit_on_initialization for osthread
1192 // resource allocation failure.
1193 static void vm_exit_on_osthread_failure(JavaThread* thread);
1194
1195 // Deferred OopHandle release support
1196 private:
1197 // List of OopHandles to be released - guarded by the Service_lock.
1198 static OopHandleList* _oop_handle_list;
1199 // Add our OopHandles to the list for the service thread to release.
1200 void add_oop_handles_for_release();
1201 // Called by the ServiceThread to release the OopHandles.
1202 static void release_oop_handles();
1203 // Called by the ServiceThread to poll if there are any OopHandles to release.
1204 // Called when holding the Service_lock.
1205 static bool has_oop_handles_to_release() {
1206 return _oop_handle_list != nullptr;
1207 }
1208 };
1209
1210 inline JavaThread* JavaThread::current_or_null() {
1211 Thread* current = Thread::current_or_null();
1212 return current != nullptr ? JavaThread::cast(current) : nullptr;
1213 }
1214
1215 class UnlockFlagSaver {
1216 private:
1217 JavaThread* _thread;
1218 bool _do_not_unlock;
1219 public:
1220 UnlockFlagSaver(JavaThread* t) {
1221 _thread = t;
1222 _do_not_unlock = t->do_not_unlock_if_synchronized();
1223 t->set_do_not_unlock_if_synchronized(false);
1224 }
1225 ~UnlockFlagSaver() {
1226 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1227 }
1228 };
1229
1230 class JNIHandleMark : public StackObj {
1231 JavaThread* _thread;
1232 public:
1233 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1234 thread->push_jni_handle_block();
1235 }
1236 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1237 };
1238
1239 #endif // SHARE_RUNTIME_JAVATHREAD_HPP