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 JNIHandleBlock;
56 class JVMCIRuntime;
57
58 class JvmtiDeferredUpdates;
59 class JvmtiSampledObjectAllocEventCollector;
60 class JvmtiThreadState;
61
62 class Metadata;
63 class OopHandleList;
64 class OopStorage;
65 class OSThread;
66
67 class ThreadsList;
68 class ThreadSafepointState;
69 class ThreadStatistics;
70
71 class vframeArray;
72 class vframe;
73 class javaVFrame;
74
75 class JavaThread;
76 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
77
78 class JavaThread: public Thread {
79 friend class VMStructs;
80 friend class JVMCIVMStructs;
81 friend class WhiteBox;
82 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
83 friend class HandshakeState;
84 friend class Continuation;
85 friend class Threads;
86 friend class ServiceThread; // for deferred OopHandle release access
87 private:
88 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
89
90 // All references to Java objects managed via OopHandles. These
91 // have to be released by the ServiceThread after the JavaThread has
92 // terminated - see add_oop_handles_for_release().
93 OopHandle _threadObj; // The Java level thread object
94 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj
95 OopHandle _jvmti_vthread;
96 OopHandle _scopedValueCache;
97
98 static OopStorage* _thread_oop_storage;
99
100 #ifdef ASSERT
101 private:
102 int _java_call_counter;
103
104 public:
105 int java_call_counter() { return _java_call_counter; }
106 void inc_java_call_counter() { _java_call_counter++; }
107 void dec_java_call_counter() {
108 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
109 _java_call_counter--;
110 }
111 private: // restore original namespace restriction
112 #endif // ifdef ASSERT
113
114 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
115
116 ThreadFunction _entry_point;
117
118 JNIEnv _jni_environment;
119
120 // Deopt support
121 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
122
123 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
124 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
125 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
126 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
127 // will be carried out as soon as possible which, in most cases, is just before deoptimization of
128 // the frame, when control returns to it.
129 JvmtiDeferredUpdates* _jvmti_deferred_updates;
130
131 // Handshake value for fixing 6243940. We need a place for the i2c
132 // adapter to store the callee Method*. This value is NEVER live
133 // across a gc point so it does NOT have to be gc'd
134 // The handshake is open ended since we can't be certain that it will
135 // be nulled. This is because we rarely ever see the race and end up
136 // in handle_wrong_method which is the backend of the handshake. See
137 // code in i2c adapters and handle_wrong_method.
138
139 Method* _callee_target;
140
141 // Used to pass back results to the interpreter or generated code running Java code.
142 oop _vm_result; // oop result is GC-preserved
143 Metadata* _vm_result_2; // non-oop result
144
145 // See ReduceInitialCardMarks: this holds the precise space interval of
146 // the most recent slow path allocation for which compiled code has
147 // elided card-marks for performance along the fast-path.
148 MemRegion _deferred_card_mark;
149
150 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
151 bool _current_pending_monitor_is_from_java; // locking is from Java code
152 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
153
154 // Active_handles points to a block of handles
155 JNIHandleBlock* _active_handles;
156
157 // One-element thread local free list
158 JNIHandleBlock* _free_handle_block;
159
160 public:
161 // For tracking the heavyweight monitor the thread is pending on.
162 ObjectMonitor* current_pending_monitor() {
163 // Use Atomic::load() to prevent data race between concurrent modification and
164 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
165 // Especially, reloading pointer from thread after null check must be prevented.
166 return Atomic::load(&_current_pending_monitor);
167 }
168 void set_current_pending_monitor(ObjectMonitor* monitor) {
169 Atomic::store(&_current_pending_monitor, monitor);
170 }
171 void set_current_pending_monitor_is_from_java(bool from_java) {
172 _current_pending_monitor_is_from_java = from_java;
173 }
174 bool current_pending_monitor_is_from_java() {
175 return _current_pending_monitor_is_from_java;
176 }
177 ObjectMonitor* current_waiting_monitor() {
178 // See the comment in current_pending_monitor() above.
179 return Atomic::load(&_current_waiting_monitor);
180 }
181 void set_current_waiting_monitor(ObjectMonitor* monitor) {
182 Atomic::store(&_current_waiting_monitor, monitor);
183 }
184
185 // JNI handle support
186 JNIHandleBlock* active_handles() const { return _active_handles; }
187 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
188 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
189 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
190
191 void push_jni_handle_block();
192 void pop_jni_handle_block();
193
194 private:
195 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
196 // allocated during deoptimization
197 // and by JNI_MonitorEnter/Exit
198
199 enum SuspendFlags {
200 // NOTE: avoid using the sign-bit as cc generates different test code
201 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
202 _trace_flag = 0x00000004U, // call tracing backend
203 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
204 };
205
206 // various suspension related flags - atomically updated
207 volatile uint32_t _suspend_flags;
208
209 inline void set_suspend_flag(SuspendFlags f);
210 inline void clear_suspend_flag(SuspendFlags f);
211
212 public:
213 inline void set_trace_flag();
214 inline void clear_trace_flag();
215 inline void set_obj_deopt_flag();
216 inline void clear_obj_deopt_flag();
217 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
218 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
219
220 // Asynchronous exception support
221 private:
222 friend class InstallAsyncExceptionHandshake;
223 friend class AsyncExceptionHandshake;
224 friend class HandshakeState;
225
226 void handle_async_exception(oop java_throwable);
227 public:
228 void install_async_exception(AsyncExceptionHandshake* aec = nullptr);
229 bool has_async_exception_condition();
230 inline void set_pending_unsafe_access_error();
231 static void send_async_exception(JavaThread* jt, oop java_throwable);
232
233 class NoAsyncExceptionDeliveryMark : public StackObj {
234 friend JavaThread;
235 JavaThread *_target;
236 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
237 inline ~NoAsyncExceptionDeliveryMark();
238 };
239
240 // Safepoint support
241 public: // Expose _thread_state for SafeFetchInt()
242 volatile JavaThreadState _thread_state;
243 private:
244 SafepointMechanism::ThreadData _poll_data;
245 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
246 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
247 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
248 #ifdef ASSERT
249 // Debug support for checking if code allows safepoints or not.
250 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
251 // mutex, or blocking on an object synchronizer (Java locking).
252 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
253 // the above cases. The class NoSafepointVerifier is used to set this counter.
254 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
255
256 public:
257 void inc_no_safepoint_count() { _no_safepoint_count++; }
258 void dec_no_safepoint_count() { _no_safepoint_count--; }
259 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
260 #endif // ASSERT
261 public:
262 // These functions check conditions before possibly going to a safepoint.
263 // including NoSafepointVerifier.
264 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
265 void check_possible_safepoint() NOT_DEBUG_RETURN;
266
267 #ifdef ASSERT
268 private:
269 volatile uint64_t _visited_for_critical_count;
270
271 public:
272 void set_visited_for_critical_count(uint64_t safepoint_id) {
273 assert(_visited_for_critical_count == 0, "Must be reset before set");
274 assert((safepoint_id & 0x1) == 1, "Must be odd");
275 _visited_for_critical_count = safepoint_id;
276 }
277 void reset_visited_for_critical_count(uint64_t safepoint_id) {
278 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
279 _visited_for_critical_count = 0;
280 }
281 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
282 return _visited_for_critical_count == safepoint_id;
283 }
284 #endif // ASSERT
285
286 // JavaThread termination support
287 public:
288 enum TerminatedTypes {
289 _not_terminated = 0xDEAD - 3,
290 _thread_exiting, // JavaThread::exit() has been called for this thread
291 _thread_gc_barrier_detached, // thread's GC barrier has been detached
292 _thread_terminated, // JavaThread is removed from thread list
293 _vm_exited // JavaThread is still executing native code, but VM is terminated
294 // only VM_Exit can set _vm_exited
295 };
296
297 private:
298 // In general a JavaThread's _terminated field transitions as follows:
299 //
300 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
301 //
302 // _vm_exited is a special value to cover the case of a JavaThread
303 // executing native code after the VM itself is terminated.
304 //
305 // A JavaThread that fails to JNI attach has these _terminated field transitions:
306 // _not_terminated => _thread_terminated
307 //
308 volatile TerminatedTypes _terminated;
309
310 jint _in_deopt_handler; // count of deoptimization
311 // handlers thread is in
312 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
313 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
314 // never locked) when throwing an exception. Used by interpreter only.
315 #if INCLUDE_JVMTI
316 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
317 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
318 bool _is_in_tmp_VTMS_transition; // thread is in temporary virtual thread mount state transition
319 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
320 #ifdef ASSERT
321 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
322 #endif
323 #endif
324
325 // JNI attach states:
326 enum JNIAttachStates {
327 _not_attaching_via_jni = 1, // thread is not attaching via JNI
328 _attaching_via_jni, // thread is attaching via JNI
329 _attached_via_jni // thread has attached via JNI
330 };
331
332 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
333 // A native thread that is attaching via JNI starts with a value
334 // of _attaching_via_jni and transitions to _attached_via_jni.
335 volatile JNIAttachStates _jni_attach_state;
336
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 // True if in a runtime call from compiled code that will deoptimize
353 // and re-execute a failed heap allocation in the interpreter.
354 bool _in_retryable_allocation;
355
356 // An id of a speculation that JVMCI compiled code can use to further describe and
357 // uniquely identify the speculative optimization guarded by an uncommon trap.
358 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
359 jlong _pending_failed_speculation;
360
361 // These fields are mutually exclusive in terms of live ranges.
362 union {
363 // Communicates the pc at which the most recent implicit exception occurred
364 // from the signal handler to a deoptimization stub.
365 address _implicit_exception_pc;
366
367 // Communicates an alternative call target to an i2c stub from a JavaCall .
368 address _alternate_call_target;
369 } _jvmci;
370
371 // The JVMCIRuntime in a JVMCI shared library
372 JVMCIRuntime* _libjvmci_runtime;
373
374 // Support for high precision, thread sensitive counters in JVMCI compiled code.
375 jlong* _jvmci_counters;
376
377 // Fast thread locals for use by JVMCI
378 jlong _jvmci_reserved0;
379 jlong _jvmci_reserved1;
380 oop _jvmci_reserved_oop0;
381
382 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
383 // be kept alive
384 nmethod* _live_nmethod;
385
386 public:
387 static jlong* _jvmci_old_thread_counters;
388 static void collect_counters(jlong* array, int length);
389
390 bool resize_counters(int current_size, int new_size);
391
392 static bool resize_all_jvmci_counters(int new_size);
393
394 void set_jvmci_reserved_oop0(oop value) {
395 _jvmci_reserved_oop0 = value;
396 }
397
398 oop get_jvmci_reserved_oop0() {
399 return _jvmci_reserved_oop0;
400 }
401
402 void set_jvmci_reserved0(jlong value) {
403 _jvmci_reserved0 = value;
404 }
405
406 jlong get_jvmci_reserved0() {
407 return _jvmci_reserved0;
408 }
409
410 void set_jvmci_reserved1(jlong value) {
411 _jvmci_reserved1 = value;
412 }
413
414 jlong get_jvmci_reserved1() {
415 return _jvmci_reserved1;
416 }
417
418 void set_live_nmethod(nmethod* nm) {
419 assert(_live_nmethod == nullptr, "only one");
420 _live_nmethod = nm;
421 }
422
423 void clear_live_nmethod() {
424 _live_nmethod = nullptr;
425 }
426
427 private:
428 #endif // INCLUDE_JVMCI
429
430 StackOverflow _stack_overflow_state;
431
432 void pretouch_stack();
433
434 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
435 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
436 // code)
437 volatile oop _exception_oop; // Exception thrown in compiled code
438 volatile address _exception_pc; // PC where exception happened
439 volatile address _exception_handler_pc; // PC for handler of exception
440 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
441
442 private:
443 // support for JNI critical regions
444 jint _jni_active_critical; // count of entries into JNI critical region
445
446 // Checked JNI: function name requires exception check
447 char* _pending_jni_exception_check_fn;
448
449 // For deadlock detection.
450 int _depth_first_number;
451
452 // JVMTI PopFrame support
453 // This is set to popframe_pending to signal that top Java frame should be popped immediately
454 int _popframe_condition;
455
456 // If reallocation of scalar replaced objects fails, we throw OOM
457 // and during exception propagation, pop the top
458 // _frames_to_pop_failed_realloc frames, the ones that reference
459 // failed reallocations.
460 int _frames_to_pop_failed_realloc;
461
462 ContinuationEntry* _cont_entry;
463 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub frame inside the
464 // continuation that we know about
465 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
466
467 // It's signed for error detection.
468 intx _held_monitor_count; // used by continuations for fast lock detection
469 intx _jni_monitor_count;
470
471 private:
472
473 friend class VMThread;
474 friend class ThreadWaitTransition;
475 friend class VM_Exit;
476
477 // Stack watermark barriers.
478 StackWatermarks _stack_watermarks;
479
480 public:
481 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
482
483 public:
484 // Constructor
485 JavaThread(); // delegating constructor
486 JavaThread(bool is_attaching_via_jni); // for main thread and JNI attached threads
487 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
488 ~JavaThread();
489
490 #ifdef ASSERT
491 // verify this JavaThread hasn't be published in the Threads::list yet
492 void verify_not_published();
493 #endif // ASSERT
494
495 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
496
497 //JNI functiontable getter/setter for JVMTI jni function table interception API.
498 void set_jni_functions(struct JNINativeInterface_* functionTable) {
499 _jni_environment.functions = functionTable;
500 }
501 struct JNINativeInterface_* get_jni_functions() {
502 return (struct JNINativeInterface_ *)_jni_environment.functions;
503 }
504
505 // This function is called at thread creation to allow
506 // platform specific thread variables to be initialized.
507 void cache_global_variables();
508
509 // Executes Shutdown.shutdown()
510 void invoke_shutdown_hooks();
511
512 // Cleanup on thread exit
513 enum ExitType {
514 normal_exit,
515 jni_detach
516 };
517 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
518
519 void cleanup_failed_attach_current_thread(bool is_daemon);
520
521 // Testers
522 virtual bool is_Java_thread() const { return true; }
523 virtual bool can_call_java() const { return true; }
524
525 virtual bool is_active_Java_thread() const;
526
527 // Thread oop. threadObj() can be null for initial JavaThread
528 // (or for threads attached via JNI)
529 oop threadObj() const;
530 void set_threadOopHandles(oop p);
531 oop vthread() const;
532 void set_vthread(oop p);
533 oop scopedValueCache() const;
534 void set_scopedValueCache(oop p);
535 void clear_scopedValueBindings();
536 oop jvmti_vthread() const;
537 void set_jvmti_vthread(oop p);
538 oop vthread_or_thread() const;
539
540 // Prepare thread and add to priority queue. If a priority is
541 // not specified, use the priority of the thread object. Threads_lock
542 // must be held while this function is called.
543 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
544
545 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
546 address saved_exception_pc() { return _saved_exception_pc; }
547
548 ThreadFunction entry_point() const { return _entry_point; }
549
550 // Allocates a new Java level thread object for this thread. thread_name may be null.
551 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
552
553 // Last frame anchor routines
554
555 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
556
557 // last_Java_sp
558 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
559 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
560
561 // last_Java_pc
562
563 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
564
565 // Safepoint support
566 inline JavaThreadState thread_state() const;
567 inline void set_thread_state(JavaThreadState s);
568 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
569 inline ThreadSafepointState* safepoint_state() const;
570 inline void set_safepoint_state(ThreadSafepointState* state);
571 inline bool is_at_poll_safepoint();
572
573 // JavaThread termination and lifecycle support:
574 void smr_delete();
575 bool on_thread_list() const { return _on_thread_list; }
576 void set_on_thread_list() { _on_thread_list = true; }
577
578 // thread has called JavaThread::exit(), thread's GC barrier is detached
579 // or thread is terminated
580 bool is_exiting() const;
581 // thread's GC barrier is NOT detached and thread is NOT terminated
582 bool is_oop_safe() const;
583 // thread is terminated (no longer on the threads list); the thread must
584 // be protected by a ThreadsListHandle to avoid potential crashes.
585 bool check_is_terminated(TerminatedTypes l_terminated) const {
586 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
587 }
588 bool is_terminated() const;
589 void set_terminated(TerminatedTypes t);
590
591 void block_if_vm_exited();
592
593 bool doing_unsafe_access() { return _doing_unsafe_access; }
594 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
595
596 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
597 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
598
599 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
600
601 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
602
603 // Continuation support
604 ContinuationEntry* last_continuation() const { return _cont_entry; }
605 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
606 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
607 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
608 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
609 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
610 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
611
612 void inc_held_monitor_count(intx i = 1, bool jni = false);
613 void dec_held_monitor_count(intx i = 1, bool jni = false);
614
615 intx held_monitor_count() { return _held_monitor_count; }
616 intx jni_monitor_count() { return _jni_monitor_count; }
617 void clear_jni_monitor_count() { _jni_monitor_count = 0; }
618
619 inline bool is_vthread_mounted() const;
620 inline const ContinuationEntry* vthread_continuation() const;
621
622 private:
623 DEBUG_ONLY(void verify_frame_info();)
624
625 // Support for thread handshake operations
626 HandshakeState _handshake;
627 public:
628 HandshakeState* handshake_state() { return &_handshake; }
629
630 // A JavaThread can always safely operate on it self and other threads
631 // can do it safely if they are the active handshaker.
632 bool is_handshake_safe_for(Thread* th) const {
633 return _handshake.active_handshaker() == th || this == th;
634 }
635
636 // Suspend/resume support for JavaThread
637 // higher-level suspension/resume logic called by the public APIs
638 bool java_suspend();
639 bool java_resume();
640 bool is_suspended() { return _handshake.is_suspended(); }
641
642 // Check for async exception in addition to safepoint.
643 static void check_special_condition_for_native_trans(JavaThread *thread);
644
645 // Synchronize with another thread that is deoptimizing objects of the
646 // current thread, i.e. reverts optimizations based on escape analysis.
647 void wait_for_object_deoptimization();
648
649 #if INCLUDE_JVMTI
650 inline void set_carrier_thread_suspended();
651 inline void clear_carrier_thread_suspended();
652
653 bool is_carrier_thread_suspended() const {
654 return _carrier_thread_suspended;
655 }
656
657 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
658 bool is_in_tmp_VTMS_transition() const { return _is_in_tmp_VTMS_transition; }
659 bool is_in_any_VTMS_transition() const { return _is_in_VTMS_transition || _is_in_tmp_VTMS_transition; }
660
661 void set_is_in_VTMS_transition(bool val);
662 void toggle_is_in_tmp_VTMS_transition() { _is_in_tmp_VTMS_transition = !_is_in_tmp_VTMS_transition; };
663
664 bool is_disable_suspend() const { return _is_disable_suspend; }
665 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
666
667 #ifdef ASSERT
668 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
669 void set_is_VTMS_transition_disabler(bool val);
670 #endif
671 #endif
672
673 // Support for object deoptimization and JFR suspension
674 void handle_special_runtime_exit_condition();
675 bool has_special_runtime_exit_condition() {
676 return (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
677 }
678
679 // Fast-locking support
680 bool is_lock_owned(address adr) const;
681
682 // Accessors for vframe array top
683 // The linked list of vframe arrays are sorted on sp. This means when we
684 // unpack the head must contain the vframe array to unpack.
685 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
686 vframeArray* vframe_array_head() const { return _vframe_array_head; }
687
688 // Side structure for deferring update of java frame locals until deopt occurs
689 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
690 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
691
692 // These only really exist to make debugging deopt problems simpler
693
694 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
695 vframeArray* vframe_array_last() const { return _vframe_array_last; }
696
697 // The special resourceMark used during deoptimization
698
699 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
700 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
701
702 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
703 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
704
705 Method* callee_target() const { return _callee_target; }
706 void set_callee_target (Method* x) { _callee_target = x; }
707
708 // Oop results of vm runtime calls
709 oop vm_result() const { return _vm_result; }
710 void set_vm_result (oop x) { _vm_result = x; }
711
712 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
713
714 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
715 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
716
717 #if INCLUDE_JVMCI
718 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
719 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
720 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
721 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
722 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
723 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
724 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
725
726 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
727 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
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 private:
881 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
882
883 public:
884 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
885 void add_monitor_chunk(MonitorChunk* chunk);
886 void remove_monitor_chunk(MonitorChunk* chunk);
887 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
888 void inc_in_deopt_handler() { _in_deopt_handler++; }
889 void dec_in_deopt_handler() {
890 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
891 if (_in_deopt_handler > 0) { // robustness
892 _in_deopt_handler--;
893 }
894 }
895
896 private:
897 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
898
899 // factor out low-level mechanics for use in both normal and error cases
900 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
901
902 public:
903
904 // Frame iteration; calls the function f for all frames on the stack
905 void frames_do(void f(frame*, const RegisterMap*));
906
907 // Memory operations
908 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
909 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
910
911 // GC operations
912 virtual void nmethods_do(NMethodClosure* cf);
913
914 // RedefineClasses Support
915 void metadata_do(MetadataClosure* f);
916
917 // Debug method asserting thread states are correct during a handshake operation.
918 DEBUG_ONLY(void verify_states_for_handshake();)
919
920 // Misc. operations
921 const char* name() const;
922 const char* name_raw() const;
923 const char* type_name() const { return "JavaThread"; }
924 static const char* name_for(oop thread_obj);
925
926 void print_on(outputStream* st, bool print_extended_info) const;
927 void print_on(outputStream* st) const { print_on(st, false); }
928 void print() const;
929 void print_thread_state_on(outputStream*) const;
930 void print_on_error(outputStream* st, char* buf, int buflen) const;
931 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
932 void verify();
933
934 // Accessing frames
935 frame last_frame() {
936 _anchor.make_walkable();
937 return pd_last_frame();
938 }
939 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
940
941 frame carrier_last_frame(RegisterMap* reg_map);
942 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
943
944 frame vthread_last_frame();
945 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
946
947 frame platform_thread_last_frame(RegisterMap* reg_map);
948 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
949 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
950 }
951
952 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
953
954 // Returns method at 'depth' java or native frames down the stack
955 // Used for security checks
956 Klass* security_get_caller_class(int depth);
957
958 // Print stack trace in external format
959 // These variants print carrier/platform thread information only.
960 void print_stack_on(outputStream* st);
961 void print_stack() { print_stack_on(tty); }
962 // This prints the currently mounted virtual thread.
963 void print_vthread_stack_on(outputStream* st);
964 // This prints the active stack: either carrier/platform or virtual.
965 void print_active_stack_on(outputStream* st);
966 // Print current stack trace for checked JNI warnings and JNI fatal errors.
967 // This is the external format from above, but selecting the platform
968 // or vthread as applicable.
969 void print_jni_stack();
970
971 // Print stack traces in various internal formats
972 void trace_stack() PRODUCT_RETURN;
973 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
974 void trace_frames() PRODUCT_RETURN;
975
976 // Print an annotated view of the stack frames
977 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
978 void validate_frame_layout() {
979 print_frame_layout(0, true);
980 }
981
982 // Function for testing deoptimization
983 void deoptimize();
984 void make_zombies();
985
986 void deoptimize_marked_methods();
987
988 public:
989 // Returns the running thread as a JavaThread
990 static JavaThread* current() {
991 return JavaThread::cast(Thread::current());
992 }
993
994 // Returns the current thread as a JavaThread, or nullptr if not attached
995 static inline JavaThread* current_or_null();
996
997 // Casts
998 static JavaThread* cast(Thread* t) {
999 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
1000 return static_cast<JavaThread*>(t);
1001 }
1002
1003 static const JavaThread* cast(const Thread* t) {
1004 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1005 return static_cast<const JavaThread*>(t);
1006 }
1007
1008 // Returns the active Java thread. Do not use this if you know you are calling
1009 // from a JavaThread, as it's slower than JavaThread::current. If called from
1010 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1011 // operation. You may not want that either.
1012 static JavaThread* active();
1013
1014 protected:
1015 virtual void pre_run();
1016 virtual void run();
1017 void thread_main_inner();
1018 virtual void post_run();
1019
1020 public:
1021 // Thread local information maintained by JVMTI.
1022 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1023 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1024 // getter is used to get this JavaThread's JvmtiThreadState if it has
1025 // one which means null can be returned. JvmtiThreadState::state_for()
1026 // is used to get the specified JavaThread's JvmtiThreadState if it has
1027 // one or it allocates a new JvmtiThreadState for the JavaThread and
1028 // returns it. JvmtiThreadState::state_for() will return null only if
1029 // the specified JavaThread is exiting.
1030 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1031 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1032
1033 #if INCLUDE_JVMTI
1034 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1035 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1036 #endif
1037
1038 // JVMTI PopFrame support
1039 // Setting and clearing popframe_condition
1040 // All of these enumerated values are bits. popframe_pending
1041 // indicates that a PopFrame() has been requested and not yet been
1042 // completed. popframe_processing indicates that that PopFrame() is in
1043 // the process of being completed. popframe_force_deopt_reexecution_bit
1044 // indicates that special handling is required when returning to a
1045 // deoptimized caller.
1046 enum PopCondition {
1047 popframe_inactive = 0x00,
1048 popframe_pending_bit = 0x01,
1049 popframe_processing_bit = 0x02,
1050 popframe_force_deopt_reexecution_bit = 0x04
1051 };
1052 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1053 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1054 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1055 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1056 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1057 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1058 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1059
1060 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1061 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1062 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1063
1064 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1065 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1066 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1067
1068 private:
1069 // Saved incoming arguments to popped frame.
1070 // Used only when popped interpreted frame returns to deoptimized frame.
1071 void* _popframe_preserved_args;
1072 int _popframe_preserved_args_size;
1073
1074 public:
1075 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1076 void* popframe_preserved_args();
1077 ByteSize popframe_preserved_args_size();
1078 WordSize popframe_preserved_args_size_in_words();
1079 void popframe_free_preserved_args();
1080
1081
1082 private:
1083 JvmtiThreadState *_jvmti_thread_state;
1084
1085 // Used by the interpreter in fullspeed mode for frame pop, method
1086 // entry, method exit and single stepping support. This field is
1087 // only set to non-zero at a safepoint or using a direct handshake
1088 // (see EnterInterpOnlyModeClosure).
1089 // It can be set to zero asynchronously to this threads execution (i.e., without
1090 // safepoint/handshake or a lock) so we have to be very careful.
1091 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1092 int _interp_only_mode;
1093
1094 public:
1095 // used by the interpreter for fullspeed debugging support (see above)
1096 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1097 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1098 int get_interp_only_mode() { return _interp_only_mode; }
1099 int set_interp_only_mode(int val) { return _interp_only_mode = val; }
1100 void increment_interp_only_mode() { ++_interp_only_mode; }
1101 void decrement_interp_only_mode() { --_interp_only_mode; }
1102
1103 // support for cached flag that indicates whether exceptions need to be posted for this thread
1104 // if this is false, we can avoid deoptimizing when events are thrown
1105 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1106 private:
1107 int _should_post_on_exceptions_flag;
1108
1109 public:
1110 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1111
1112 private:
1113 ThreadStatistics *_thread_stat;
1114
1115 public:
1116 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1117
1118 // Return a blocker object for which this thread is blocked parking.
1119 oop current_park_blocker();
1120
1121 private:
1122 static size_t _stack_size_at_create;
1123
1124 public:
1125 static inline size_t stack_size_at_create(void) {
1126 return _stack_size_at_create;
1127 }
1128 static inline void set_stack_size_at_create(size_t value) {
1129 _stack_size_at_create = value;
1130 }
1131
1132 // Machine dependent stuff
1133 #include OS_CPU_HEADER(javaThread)
1134
1135 // JSR166 per-thread parker
1136 private:
1137 Parker _parker;
1138 public:
1139 Parker* parker() { return &_parker; }
1140
1141 public:
1142 // clearing/querying jni attach status
1143 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1144 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1145 inline void set_done_attaching_via_jni();
1146
1147 // Stack dump assistance:
1148 // Track the class we want to initialize but for which we have to wait
1149 // on its init_lock() because it is already being initialized.
1150 void set_class_to_be_initialized(InstanceKlass* k);
1151 InstanceKlass* class_to_be_initialized() const;
1152
1153 private:
1154 InstanceKlass* _class_to_be_initialized;
1155
1156 // java.lang.Thread.sleep support
1157 ParkEvent * _SleepEvent;
1158 public:
1159 bool sleep(jlong millis);
1160 bool sleep_nanos(jlong nanos);
1161
1162 // java.lang.Thread interruption support
1163 void interrupt();
1164 bool is_interrupted(bool clear_interrupted);
1165
1166 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1167 // the Java code in Object::wait which are not present in RawMonitorWait.
1168 bool get_and_clear_interrupted();
1169
1170 private:
1171 LockStack _lock_stack;
1172
1173 public:
1174 LockStack& lock_stack() { return _lock_stack; }
1175
1176 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1177 // Those offsets are used in code generators to access the LockStack that is embedded in this
1178 // JavaThread structure. Those accesses are relative to the current thread, which
1179 // is typically in a dedicated register.
1180 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1181 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1182
1183 static OopStorage* thread_oop_storage();
1184
1185 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1186
1187 // Helper function to create the java.lang.Thread object for a
1188 // VM-internal thread. The thread will have the given name and be
1189 // part of the System ThreadGroup.
1190 static Handle create_system_thread_object(const char* name, TRAPS);
1191
1192 // Helper function to start a VM-internal daemon thread.
1193 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1194 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1195 Handle thread_oop, ThreadPriority prio);
1196
1197 // Helper function to do vm_exit_on_initialization for osthread
1198 // resource allocation failure.
1199 static void vm_exit_on_osthread_failure(JavaThread* thread);
1200
1201 // Deferred OopHandle release support
1202 private:
1203 // List of OopHandles to be released - guarded by the Service_lock.
1204 static OopHandleList* _oop_handle_list;
1205 // Add our OopHandles to the list for the service thread to release.
1206 void add_oop_handles_for_release();
1207 // Called by the ServiceThread to release the OopHandles.
1208 static void release_oop_handles();
1209 // Called by the ServiceThread to poll if there are any OopHandles to release.
1210 // Called when holding the Service_lock.
1211 static bool has_oop_handles_to_release() {
1212 return _oop_handle_list != nullptr;
1213 }
1214 };
1215
1216 inline JavaThread* JavaThread::current_or_null() {
1217 Thread* current = Thread::current_or_null();
1218 return current != nullptr ? JavaThread::cast(current) : nullptr;
1219 }
1220
1221 class UnlockFlagSaver {
1222 private:
1223 JavaThread* _thread;
1224 bool _do_not_unlock;
1225 public:
1226 UnlockFlagSaver(JavaThread* t) {
1227 _thread = t;
1228 _do_not_unlock = t->do_not_unlock_if_synchronized();
1229 t->set_do_not_unlock_if_synchronized(false);
1230 }
1231 ~UnlockFlagSaver() {
1232 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1233 }
1234 };
1235
1236 class JNIHandleMark : public StackObj {
1237 JavaThread* _thread;
1238 public:
1239 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1240 thread->push_jni_handle_block();
1241 }
1242 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1243 };
1244
1245 #endif // SHARE_RUNTIME_JAVATHREAD_HPP