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