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