1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #ifndef SHARE_RUNTIME_JAVATHREAD_HPP
27 #define SHARE_RUNTIME_JAVATHREAD_HPP
28
29 #include "jni.h"
30 #include "memory/allocation.hpp"
31 #include "oops/oop.hpp"
32 #include "oops/oopHandle.hpp"
33 #include "runtime/frame.hpp"
34 #include "runtime/globals.hpp"
35 #include "runtime/handshake.hpp"
36 #include "runtime/javaFrameAnchor.hpp"
37 #include "runtime/lockStack.hpp"
38 #include "runtime/park.hpp"
39 #include "runtime/safepointMechanism.hpp"
40 #include "runtime/stackWatermarkSet.hpp"
41 #include "runtime/stackOverflow.hpp"
42 #include "runtime/thread.hpp"
43 #include "runtime/threadHeapSampler.hpp"
44 #include "runtime/threadStatisticalInfo.hpp"
45 #include "utilities/exceptions.hpp"
46 #include "utilities/globalDefinitions.hpp"
47 #include "utilities/macros.hpp"
48 #if INCLUDE_JFR
49 #include "jfr/support/jfrThreadExtension.hpp"
50 #endif
51
52 class AsyncExceptionHandshake;
53 class ContinuationEntry;
54 class DeoptResourceMark;
55 class InternalOOMEMark;
56 class JNIHandleBlock;
57 class JVMCIRuntime;
58
59 class JvmtiDeferredUpdates;
60 class JvmtiSampledObjectAllocEventCollector;
61 class JvmtiThreadState;
62
63 class Metadata;
64 class ObjectMonitor;
65 class OopHandleList;
66 class OopStorage;
67 class OSThread;
68
69 class ThreadsList;
70 class ThreadSafepointState;
71 class ThreadStatistics;
72
73 class vframeArray;
74 class vframe;
75 class javaVFrame;
76
77 class JavaThread;
78 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
79
80 class JavaThread: public Thread {
81 friend class VMStructs;
82 friend class JVMCIVMStructs;
83 friend class WhiteBox;
84 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
85 friend class HandshakeState;
86 friend class Continuation;
87 friend class Threads;
88 friend class ServiceThread; // for deferred OopHandle release access
89 private:
90 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
91
92 // All references to Java objects managed via OopHandles. These
93 // have to be released by the ServiceThread after the JavaThread has
94 // terminated - see add_oop_handles_for_release().
95 OopHandle _threadObj; // The Java level thread object
96 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj
97 OopHandle _jvmti_vthread;
98 OopHandle _scopedValueCache;
99
100 static OopStorage* _thread_oop_storage;
101
102 #ifdef ASSERT
103 private:
104 int _java_call_counter;
105
106 public:
107 int java_call_counter() { return _java_call_counter; }
108 void inc_java_call_counter() { _java_call_counter++; }
109 void dec_java_call_counter() {
110 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
111 _java_call_counter--;
112 }
113 private: // restore original namespace restriction
114 #endif // ifdef ASSERT
115
116 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
117
118 ThreadFunction _entry_point;
119
120 JNIEnv _jni_environment;
121
122 // Deopt support
123 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
124
125 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
126 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
127 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
128 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
129 // will be carried out as soon as possible which, in most cases, is just before deoptimization of
130 // the frame, when control returns to it.
131 JvmtiDeferredUpdates* _jvmti_deferred_updates;
132
133 // Handshake value for fixing 6243940. We need a place for the i2c
134 // adapter to store the callee Method*. This value is NEVER live
135 // across a gc point so it does NOT have to be gc'd
136 // The handshake is open ended since we can't be certain that it will
137 // be nulled. This is because we rarely ever see the race and end up
138 // in handle_wrong_method which is the backend of the handshake. See
139 // code in i2c adapters and handle_wrong_method.
140
141 Method* _callee_target;
142
143 // Used to pass back results to the interpreter or generated code running Java code.
144 oop _vm_result; // oop result is GC-preserved
145 Metadata* _vm_result_2; // non-oop result
146
147 // See ReduceInitialCardMarks: this holds the precise space interval of
148 // the most recent slow path allocation for which compiled code has
149 // elided card-marks for performance along the fast-path.
150 MemRegion _deferred_card_mark;
151
152 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
153 bool _current_pending_monitor_is_from_java; // locking is from Java code
154 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
155
156 // Active_handles points to a block of handles
157 JNIHandleBlock* _active_handles;
158
159 // One-element thread local free list
160 JNIHandleBlock* _free_handle_block;
161
162 public:
163 // For tracking the heavyweight monitor the thread is pending on.
164 ObjectMonitor* current_pending_monitor() {
165 // Use Atomic::load() to prevent data race between concurrent modification and
166 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
167 // Especially, reloading pointer from thread after null check must be prevented.
168 return Atomic::load(&_current_pending_monitor);
169 }
170 void set_current_pending_monitor(ObjectMonitor* monitor) {
171 Atomic::store(&_current_pending_monitor, monitor);
172 }
173 void set_current_pending_monitor_is_from_java(bool from_java) {
174 _current_pending_monitor_is_from_java = from_java;
175 }
176 bool current_pending_monitor_is_from_java() {
177 return _current_pending_monitor_is_from_java;
178 }
179 ObjectMonitor* current_waiting_monitor() {
180 // See the comment in current_pending_monitor() above.
181 return Atomic::load(&_current_waiting_monitor);
182 }
183 void set_current_waiting_monitor(ObjectMonitor* monitor) {
184 Atomic::store(&_current_waiting_monitor, monitor);
185 }
186
187 // JNI handle support
188 JNIHandleBlock* active_handles() const { return _active_handles; }
189 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
190 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
191 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
192
193 void push_jni_handle_block();
194 void pop_jni_handle_block();
195
196 private:
197 enum SuspendFlags {
198 // NOTE: avoid using the sign-bit as cc generates different test code
199 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
200 _trace_flag = 0x00000004U, // call tracing backend
201 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
202 };
203
204 // various suspension related flags - atomically updated
205 volatile uint32_t _suspend_flags;
206
207 inline void set_suspend_flag(SuspendFlags f);
208 inline void clear_suspend_flag(SuspendFlags f);
209
210 public:
211 inline void set_trace_flag();
212 inline void clear_trace_flag();
213 inline void set_obj_deopt_flag();
214 inline void clear_obj_deopt_flag();
215 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
216 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
217
218 // Asynchronous exception support
219 private:
220 friend class InstallAsyncExceptionHandshake;
221 friend class AsyncExceptionHandshake;
222 friend class HandshakeState;
223
224 void handle_async_exception(oop java_throwable);
225 public:
226 void install_async_exception(AsyncExceptionHandshake* aec = nullptr);
227 bool has_async_exception_condition();
228 inline void set_pending_unsafe_access_error();
229 static void send_async_exception(JavaThread* jt, oop java_throwable);
230
231 class NoAsyncExceptionDeliveryMark : public StackObj {
232 friend JavaThread;
233 JavaThread *_target;
234 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
235 inline ~NoAsyncExceptionDeliveryMark();
236 };
237
238 // Safepoint support
239 public: // Expose _thread_state for SafeFetchInt()
240 volatile JavaThreadState _thread_state;
241 private:
242 SafepointMechanism::ThreadData _poll_data;
243 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
244 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
245 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
246 #ifdef ASSERT
247 // Debug support for checking if code allows safepoints or not.
248 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
249 // mutex, or blocking on an object synchronizer (Java locking).
250 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
251 // the above cases. The class NoSafepointVerifier is used to set this counter.
252 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
253
254 public:
255 void inc_no_safepoint_count() { _no_safepoint_count++; }
256 void dec_no_safepoint_count() { _no_safepoint_count--; }
257 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
258 #endif // ASSERT
259 public:
260 // These functions check conditions before possibly going to a safepoint.
261 // including NoSafepointVerifier.
262 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
263 void check_possible_safepoint() NOT_DEBUG_RETURN;
264
265 #ifdef ASSERT
266 private:
267 volatile uint64_t _visited_for_critical_count;
268
269 public:
270 void set_visited_for_critical_count(uint64_t safepoint_id) {
271 assert(_visited_for_critical_count == 0, "Must be reset before set");
272 assert((safepoint_id & 0x1) == 1, "Must be odd");
273 _visited_for_critical_count = safepoint_id;
274 }
275 void reset_visited_for_critical_count(uint64_t safepoint_id) {
276 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
277 _visited_for_critical_count = 0;
278 }
279 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
280 return _visited_for_critical_count == safepoint_id;
281 }
282 #endif // ASSERT
283
284 // JavaThread termination support
285 public:
286 enum TerminatedTypes {
287 _not_terminated = 0xDEAD - 3,
288 _thread_exiting, // JavaThread::exit() has been called for this thread
289 _thread_gc_barrier_detached, // thread's GC barrier has been detached
290 _thread_terminated, // JavaThread is removed from thread list
291 _vm_exited // JavaThread is still executing native code, but VM is terminated
292 // only VM_Exit can set _vm_exited
293 };
294
295 private:
296 // In general a JavaThread's _terminated field transitions as follows:
297 //
298 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
299 //
300 // _vm_exited is a special value to cover the case of a JavaThread
301 // executing native code after the VM itself is terminated.
302 //
303 // A JavaThread that fails to JNI attach has these _terminated field transitions:
304 // _not_terminated => _thread_terminated
305 //
306 volatile TerminatedTypes _terminated;
307
308 jint _in_deopt_handler; // count of deoptimization
309 // handlers thread is in
310 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
311 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
312 // never locked) when throwing an exception. Used by interpreter only.
313 #if INCLUDE_JVMTI
314 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
315 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
316 bool _is_in_tmp_VTMS_transition; // thread is in temporary virtual thread mount state transition
317 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
318 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers
319 #ifdef ASSERT
320 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
321 #endif
322 #endif
323
324 // JNI attach states:
325 enum JNIAttachStates {
326 _not_attaching_via_jni = 1, // thread is not attaching via JNI
327 _attaching_via_jni, // thread is attaching via JNI
328 _attached_via_jni // thread has attached via JNI
329 };
330
331 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
332 // A native thread that is attaching via JNI starts with a value
333 // of _attaching_via_jni and transitions to _attached_via_jni.
334 volatile JNIAttachStates _jni_attach_state;
335
336 // In scope of an InternalOOMEMark?
337 bool _is_in_internal_oome_mark;
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 // An id of a speculation that JVMCI compiled code can use to further describe and
354 // uniquely identify the speculative optimization guarded by an uncommon trap.
355 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
356 jlong _pending_failed_speculation;
357
358 // These fields are mutually exclusive in terms of live ranges.
359 union {
360 // Communicates the pc at which the most recent implicit exception occurred
361 // from the signal handler to a deoptimization stub.
362 address _implicit_exception_pc;
363
364 // Communicates an alternative call target to an i2c stub from a JavaCall .
365 address _alternate_call_target;
366 } _jvmci;
367
368 // The JVMCIRuntime in a JVMCI shared library
369 JVMCIRuntime* _libjvmci_runtime;
370
371 // Support for high precision, thread sensitive counters in JVMCI compiled code.
372 jlong* _jvmci_counters;
373
374 // Fast thread locals for use by JVMCI
375 jlong _jvmci_reserved0;
376 jlong _jvmci_reserved1;
377 oop _jvmci_reserved_oop0;
378
379 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
380 // be kept alive
381 nmethod* _live_nmethod;
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 void set_live_nmethod(nmethod* nm) {
416 assert(_live_nmethod == nullptr, "only one");
417 _live_nmethod = nm;
418 }
419
420 void clear_live_nmethod() {
421 _live_nmethod = nullptr;
422 }
423
424 private:
425 #endif // INCLUDE_JVMCI
426
427 StackOverflow _stack_overflow_state;
428
429 void pretouch_stack();
430
431 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
432 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
433 // code)
434 volatile oop _exception_oop; // Exception thrown in compiled code
435 volatile address _exception_pc; // PC where exception happened
436 volatile address _exception_handler_pc; // PC for handler of exception
437 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
438
439 private:
440 // support for JNI critical regions
441 jint _jni_active_critical; // count of entries into JNI critical region
442
443 // Checked JNI: function name requires exception check
444 char* _pending_jni_exception_check_fn;
445
446 // For deadlock detection.
447 int _depth_first_number;
448
449 // JVMTI PopFrame support
450 // This is set to popframe_pending to signal that top Java frame should be popped immediately
451 int _popframe_condition;
452
453 // If reallocation of scalar replaced objects fails, we throw OOM
454 // and during exception propagation, pop the top
455 // _frames_to_pop_failed_realloc frames, the ones that reference
456 // failed reallocations.
457 int _frames_to_pop_failed_realloc;
458
459 ContinuationEntry* _cont_entry;
460 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub frame inside the
461 // continuation that we know about
462 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
463
464 // It's signed for error detection.
465 intx _held_monitor_count; // used by continuations for fast lock detection
466 intx _jni_monitor_count;
467
468 private:
469
470 friend class VMThread;
471 friend class ThreadWaitTransition;
472 friend class VM_Exit;
473
474 // Stack watermark barriers.
475 StackWatermarks _stack_watermarks;
476
477 public:
478 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
479
480 public:
481 // Constructor
482 JavaThread(); // delegating constructor
483 JavaThread(bool is_attaching_via_jni); // for main thread and JNI attached threads
484 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
485 ~JavaThread();
486
487 #ifdef ASSERT
488 // verify this JavaThread hasn't be published in the Threads::list yet
489 void verify_not_published();
490 #endif // ASSERT
491
492 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
493
494 //JNI functiontable getter/setter for JVMTI jni function table interception API.
495 void set_jni_functions(struct JNINativeInterface_* functionTable) {
496 _jni_environment.functions = functionTable;
497 }
498 struct JNINativeInterface_* get_jni_functions() {
499 return (struct JNINativeInterface_ *)_jni_environment.functions;
500 }
501
502 // This function is called at thread creation to allow
503 // platform specific thread variables to be initialized.
504 void cache_global_variables();
505
506 // Executes Shutdown.shutdown()
507 void invoke_shutdown_hooks();
508
509 // Cleanup on thread exit
510 enum ExitType {
511 normal_exit,
512 jni_detach
513 };
514 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
515
516 void cleanup_failed_attach_current_thread(bool is_daemon);
517
518 // Testers
519 virtual bool is_Java_thread() const { return true; }
520 virtual bool can_call_java() const { return true; }
521
522 virtual bool is_active_Java_thread() const;
523
524 // Thread oop. threadObj() can be null for initial JavaThread
525 // (or for threads attached via JNI)
526 oop threadObj() const;
527 void set_threadOopHandles(oop p);
528 oop vthread() const;
529 void set_vthread(oop p);
530 oop scopedValueCache() const;
531 void set_scopedValueCache(oop p);
532 void clear_scopedValueBindings();
533 oop jvmti_vthread() const;
534 void set_jvmti_vthread(oop p);
535 oop vthread_or_thread() const;
536
537 // Prepare thread and add to priority queue. If a priority is
538 // not specified, use the priority of the thread object. Threads_lock
539 // must be held while this function is called.
540 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
541
542 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
543 address saved_exception_pc() { return _saved_exception_pc; }
544
545 ThreadFunction entry_point() const { return _entry_point; }
546
547 // Allocates a new Java level thread object for this thread. thread_name may be null.
548 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
549
550 // Last frame anchor routines
551
552 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
553
554 // last_Java_sp
555 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
556 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
557
558 // last_Java_pc
559
560 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
561
562 // Safepoint support
563 inline JavaThreadState thread_state() const;
564 inline void set_thread_state(JavaThreadState s);
565 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
566 inline ThreadSafepointState* safepoint_state() const;
567 inline void set_safepoint_state(ThreadSafepointState* state);
568 inline bool is_at_poll_safepoint();
569
570 // JavaThread termination and lifecycle support:
571 void smr_delete();
572 bool on_thread_list() const { return _on_thread_list; }
573 void set_on_thread_list() { _on_thread_list = true; }
574
575 // thread has called JavaThread::exit(), thread's GC barrier is detached
576 // or thread is terminated
577 bool is_exiting() const;
578 // thread's GC barrier is NOT detached and thread is NOT terminated
579 bool is_oop_safe() const;
580 // thread is terminated (no longer on the threads list); the thread must
581 // be protected by a ThreadsListHandle to avoid potential crashes.
582 bool check_is_terminated(TerminatedTypes l_terminated) const {
583 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
584 }
585 bool is_terminated() const;
586 void set_terminated(TerminatedTypes t);
587
588 void block_if_vm_exited();
589
590 bool doing_unsafe_access() { return _doing_unsafe_access; }
591 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
592
593 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
594 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
595
596 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
597
598 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
599
600 // Continuation support
601 ContinuationEntry* last_continuation() const { return _cont_entry; }
602 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
603 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
604 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
605 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
606 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
607 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
608
609 void inc_held_monitor_count(intx i = 1, bool jni = false);
610 void dec_held_monitor_count(intx i = 1, bool jni = false);
611
612 intx held_monitor_count() { return _held_monitor_count; }
613 intx jni_monitor_count() { return _jni_monitor_count; }
614 void clear_jni_monitor_count() { _jni_monitor_count = 0; }
615
616 inline bool is_vthread_mounted() const;
617 inline const ContinuationEntry* vthread_continuation() const;
618
619 private:
620 DEBUG_ONLY(void verify_frame_info();)
621
622 // Support for thread handshake operations
623 HandshakeState _handshake;
624 public:
625 HandshakeState* handshake_state() { return &_handshake; }
626
627 // A JavaThread can always safely operate on it self and other threads
628 // can do it safely if they are the active handshaker.
629 bool is_handshake_safe_for(Thread* th) const {
630 return _handshake.active_handshaker() == th || this == th;
631 }
632
633 // Suspend/resume support for JavaThread
634 // higher-level suspension/resume logic called by the public APIs
635 bool java_suspend();
636 bool java_resume();
637 bool is_suspended() { return _handshake.is_suspended(); }
638
639 // Check for async exception in addition to safepoint.
640 static void check_special_condition_for_native_trans(JavaThread *thread);
641
642 // Synchronize with another thread that is deoptimizing objects of the
643 // current thread, i.e. reverts optimizations based on escape analysis.
644 void wait_for_object_deoptimization();
645
646 #if INCLUDE_JVMTI
647 inline void set_carrier_thread_suspended();
648 inline void clear_carrier_thread_suspended();
649
650 bool is_carrier_thread_suspended() const {
651 return _carrier_thread_suspended;
652 }
653
654 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
655 bool is_in_tmp_VTMS_transition() const { return _is_in_tmp_VTMS_transition; }
656 bool is_in_any_VTMS_transition() const { return _is_in_VTMS_transition || _is_in_tmp_VTMS_transition; }
657
658 void set_is_in_VTMS_transition(bool val);
659 void toggle_is_in_tmp_VTMS_transition() { _is_in_tmp_VTMS_transition = !_is_in_tmp_VTMS_transition; };
660
661 bool is_disable_suspend() const { return _is_disable_suspend; }
662 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
663
664 bool VTMS_transition_mark() const { return Atomic::load(&_VTMS_transition_mark); }
665 void set_VTMS_transition_mark(bool val) { Atomic::store(&_VTMS_transition_mark, val); }
666
667 #ifdef ASSERT
668 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
669 void set_is_VTMS_transition_disabler(bool val);
670 #endif
671 #endif
672
673 // Support for object deoptimization and JFR suspension
674 void handle_special_runtime_exit_condition();
675 bool has_special_runtime_exit_condition() {
676 return (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
677 }
678
679 // Stack-locking support (not for LM_LIGHTWEIGHT)
680 bool is_lock_owned(address adr) const;
681
682 // Accessors for vframe array top
683 // The linked list of vframe arrays are sorted on sp. This means when we
684 // unpack the head must contain the vframe array to unpack.
685 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
686 vframeArray* vframe_array_head() const { return _vframe_array_head; }
687
688 // Side structure for deferring update of java frame locals until deopt occurs
689 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
690 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
691
692 // These only really exist to make debugging deopt problems simpler
693
694 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
695 vframeArray* vframe_array_last() const { return _vframe_array_last; }
696
697 // The special resourceMark used during deoptimization
698
699 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
700 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
701
702 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
703 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
704
705 Method* callee_target() const { return _callee_target; }
706 void set_callee_target (Method* x) { _callee_target = x; }
707
708 // Oop results of vm runtime calls
709 oop vm_result() const { return _vm_result; }
710 void set_vm_result (oop x) { _vm_result = x; }
711
712 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
713
714 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
715 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
716
717 // Is thread in scope of an InternalOOMEMark?
718 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
719 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
720
721 #if INCLUDE_JVMCI
722 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
723 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
724 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
725 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
726 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
727 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
728 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
729
730 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
731 void set_libjvmci_runtime(JVMCIRuntime* rt) {
732 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
733 _libjvmci_runtime = rt;
734 }
735 #endif // INCLUDE_JVMCI
736
737 // Exception handling for compiled methods
738 oop exception_oop() const;
739 address exception_pc() const { return _exception_pc; }
740
741 void set_exception_oop(oop o);
742 void set_exception_pc(address a) { _exception_pc = a; }
743 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
744 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
745
746 void clear_exception_oop_and_pc() {
747 set_exception_oop(nullptr);
748 set_exception_pc(nullptr);
749 }
750
751 // Check if address is in the usable part of the stack (excludes protected
752 // guard pages). Can be applied to any thread and is an approximation for
753 // using is_in_live_stack when the query has to happen from another thread.
754 bool is_in_usable_stack(address adr) const {
755 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
756 }
757
758 // Misc. accessors/mutators
759 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
760
761 // For assembly stub generation
762 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
763 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
764 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
765 static ByteSize pending_jni_exception_check_fn_offset() {
766 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
767 }
768 static ByteSize last_Java_sp_offset() {
769 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
770 }
771 static ByteSize last_Java_pc_offset() {
772 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
773 }
774 static ByteSize frame_anchor_offset() {
775 return byte_offset_of(JavaThread, _anchor);
776 }
777 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
778 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
779 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
780 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
781 static ByteSize polling_word_offset() { return byte_offset_of(JavaThread, _poll_data) + byte_offset_of(SafepointMechanism::ThreadData, _polling_word);}
782 static ByteSize polling_page_offset() { return byte_offset_of(JavaThread, _poll_data) + byte_offset_of(SafepointMechanism::ThreadData, _polling_page);}
783 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
784 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
785 #if INCLUDE_JVMCI
786 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
787 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
788 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
789 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
790 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
791 #endif // INCLUDE_JVMCI
792 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
793 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
794 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
795 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
796
797 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
798
799 // StackOverflow offsets
800 static ByteSize stack_overflow_limit_offset() {
801 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
802 }
803 static ByteSize stack_guard_state_offset() {
804 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
805 }
806 static ByteSize reserved_stack_activation_offset() {
807 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
808 }
809 static ByteSize shadow_zone_safe_limit() {
810 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
811 }
812 static ByteSize shadow_zone_growth_watermark() {
813 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
814 }
815
816 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
817
818 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
819 static ByteSize should_post_on_exceptions_flag_offset() {
820 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
821 }
822 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
823 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
824
825 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
826 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
827 static ByteSize held_monitor_count_offset() { return byte_offset_of(JavaThread, _held_monitor_count); }
828 static ByteSize jni_monitor_count_offset() { return byte_offset_of(JavaThread, _jni_monitor_count); }
829
830 #if INCLUDE_JVMTI
831 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); }
832 static ByteSize is_in_tmp_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_tmp_VTMS_transition); }
833 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
834 #endif
835
836 // Returns the jni environment for this thread
837 JNIEnv* jni_environment() { return &_jni_environment; }
838
839 // Returns the current thread as indicated by the given JNIEnv.
840 // We don't assert it is Thread::current here as that is done at the
841 // external JNI entry points where the JNIEnv is passed into the VM.
842 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
843 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
844 // We can't normally get here in a thread that has completed its
845 // execution and so "is_terminated", except when the call is from
846 // AsyncGetCallTrace, which can be triggered by a signal at any point in
847 // a thread's lifecycle. A thread is also considered terminated if the VM
848 // has exited, so we have to check this and block in case this is a daemon
849 // thread returning to the VM (the JNI DirectBuffer entry points rely on
850 // this).
851 if (current->is_terminated()) {
852 current->block_if_vm_exited();
853 }
854 return current;
855 }
856
857 // JNI critical regions. These can nest.
858 bool in_critical() { return _jni_active_critical > 0; }
859 bool in_last_critical() { return _jni_active_critical == 1; }
860 inline void enter_critical();
861 void exit_critical() {
862 assert(Thread::current() == this, "this must be current thread");
863 _jni_active_critical--;
864 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
865 }
866
867 // Checked JNI: is the programmer required to check for exceptions, if so specify
868 // which function name. Returning to a Java frame should implicitly clear the
869 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
870 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
871 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
872 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
873 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
874 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
875 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
876
877 // For deadlock detection
878 int depth_first_number() { return _depth_first_number; }
879 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
880
881 public:
882 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
883 void inc_in_deopt_handler() { _in_deopt_handler++; }
884 void dec_in_deopt_handler() {
885 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
886 if (_in_deopt_handler > 0) { // robustness
887 _in_deopt_handler--;
888 }
889 }
890
891 private:
892 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
893
894 // factor out low-level mechanics for use in both normal and error cases
895 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
896
897 public:
898
899 // Frame iteration; calls the function f for all frames on the stack
900 void frames_do(void f(frame*, const RegisterMap*));
901
902 // Memory operations
903 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
904 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
905
906 // GC operations
907 virtual void nmethods_do(NMethodClosure* cf);
908
909 // RedefineClasses Support
910 void metadata_do(MetadataClosure* f);
911
912 // Debug method asserting thread states are correct during a handshake operation.
913 DEBUG_ONLY(void verify_states_for_handshake();)
914
915 // Misc. operations
916 const char* name() const;
917 const char* name_raw() const;
918 const char* type_name() const { return "JavaThread"; }
919 static const char* name_for(oop thread_obj);
920
921 void print_on(outputStream* st, bool print_extended_info) const;
922 void print_on(outputStream* st) const { print_on(st, false); }
923 void print() const;
924 void print_thread_state_on(outputStream*) const;
925 void print_on_error(outputStream* st, char* buf, int buflen) const;
926 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
927 void verify();
928
929 // Accessing frames
930 frame last_frame() {
931 _anchor.make_walkable();
932 return pd_last_frame();
933 }
934 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
935
936 frame carrier_last_frame(RegisterMap* reg_map);
937 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
938
939 frame vthread_last_frame();
940 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
941
942 frame platform_thread_last_frame(RegisterMap* reg_map);
943 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
944 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
945 }
946
947 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
948
949 // Returns method at 'depth' java or native frames down the stack
950 // Used for security checks
951 Klass* security_get_caller_class(int depth);
952
953 // Print stack trace in external format
954 // These variants print carrier/platform thread information only.
955 void print_stack_on(outputStream* st);
956 void print_stack() { print_stack_on(tty); }
957 // This prints the currently mounted virtual thread.
958 void print_vthread_stack_on(outputStream* st);
959 // This prints the active stack: either carrier/platform or virtual.
960 void print_active_stack_on(outputStream* st);
961 // Print current stack trace for checked JNI warnings and JNI fatal errors.
962 // This is the external format from above, but selecting the platform
963 // or vthread as applicable.
964 void print_jni_stack();
965
966 // Print stack traces in various internal formats
967 void trace_stack() PRODUCT_RETURN;
968 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
969 void trace_frames() PRODUCT_RETURN;
970
971 // Print an annotated view of the stack frames
972 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
973 void validate_frame_layout() {
974 print_frame_layout(0, true);
975 }
976
977 // Function for testing deoptimization
978 void deoptimize();
979 void make_zombies();
980
981 void deoptimize_marked_methods();
982
983 public:
984 // Returns the running thread as a JavaThread
985 static JavaThread* current() {
986 return JavaThread::cast(Thread::current());
987 }
988
989 // Returns the current thread as a JavaThread, or nullptr if not attached
990 static inline JavaThread* current_or_null();
991
992 // Casts
993 static JavaThread* cast(Thread* t) {
994 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
995 return static_cast<JavaThread*>(t);
996 }
997
998 static const JavaThread* cast(const Thread* t) {
999 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1000 return static_cast<const JavaThread*>(t);
1001 }
1002
1003 // Returns the active Java thread. Do not use this if you know you are calling
1004 // from a JavaThread, as it's slower than JavaThread::current. If called from
1005 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1006 // operation. You may not want that either.
1007 static JavaThread* active();
1008
1009 protected:
1010 virtual void pre_run();
1011 virtual void run();
1012 void thread_main_inner();
1013 virtual void post_run();
1014
1015 public:
1016 // Thread local information maintained by JVMTI.
1017 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1018 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1019 // getter is used to get this JavaThread's JvmtiThreadState if it has
1020 // one which means null can be returned. JvmtiThreadState::state_for()
1021 // is used to get the specified JavaThread's JvmtiThreadState if it has
1022 // one or it allocates a new JvmtiThreadState for the JavaThread and
1023 // returns it. JvmtiThreadState::state_for() will return null only if
1024 // the specified JavaThread is exiting.
1025 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1026 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1027
1028 #if INCLUDE_JVMTI
1029 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1030 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1031 #endif
1032
1033 // JVMTI PopFrame support
1034 // Setting and clearing popframe_condition
1035 // All of these enumerated values are bits. popframe_pending
1036 // indicates that a PopFrame() has been requested and not yet been
1037 // completed. popframe_processing indicates that that PopFrame() is in
1038 // the process of being completed. popframe_force_deopt_reexecution_bit
1039 // indicates that special handling is required when returning to a
1040 // deoptimized caller.
1041 enum PopCondition {
1042 popframe_inactive = 0x00,
1043 popframe_pending_bit = 0x01,
1044 popframe_processing_bit = 0x02,
1045 popframe_force_deopt_reexecution_bit = 0x04
1046 };
1047 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1048 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1049 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1050 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1051 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1052 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1053 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1054
1055 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1056 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1057 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1058
1059 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1060 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1061 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1062
1063 private:
1064 // Saved incoming arguments to popped frame.
1065 // Used only when popped interpreted frame returns to deoptimized frame.
1066 void* _popframe_preserved_args;
1067 int _popframe_preserved_args_size;
1068
1069 public:
1070 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1071 void* popframe_preserved_args();
1072 ByteSize popframe_preserved_args_size();
1073 WordSize popframe_preserved_args_size_in_words();
1074 void popframe_free_preserved_args();
1075
1076
1077 private:
1078 JvmtiThreadState *_jvmti_thread_state;
1079
1080 // Used by the interpreter in fullspeed mode for frame pop, method
1081 // entry, method exit and single stepping support. This field is
1082 // only set to non-zero at a safepoint or using a direct handshake
1083 // (see EnterInterpOnlyModeClosure).
1084 // It can be set to zero asynchronously to this threads execution (i.e., without
1085 // safepoint/handshake or a lock) so we have to be very careful.
1086 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1087 int _interp_only_mode;
1088
1089 public:
1090 // used by the interpreter for fullspeed debugging support (see above)
1091 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1092 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1093 int get_interp_only_mode() { return _interp_only_mode; }
1094 int set_interp_only_mode(int val) { return _interp_only_mode = val; }
1095 void increment_interp_only_mode() { ++_interp_only_mode; }
1096 void decrement_interp_only_mode() { --_interp_only_mode; }
1097
1098 // support for cached flag that indicates whether exceptions need to be posted for this thread
1099 // if this is false, we can avoid deoptimizing when events are thrown
1100 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1101 private:
1102 int _should_post_on_exceptions_flag;
1103
1104 public:
1105 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1106
1107 private:
1108 ThreadStatistics *_thread_stat;
1109
1110 public:
1111 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1112
1113 // Return a blocker object for which this thread is blocked parking.
1114 oop current_park_blocker();
1115
1116 private:
1117 static size_t _stack_size_at_create;
1118
1119 public:
1120 static inline size_t stack_size_at_create(void) {
1121 return _stack_size_at_create;
1122 }
1123 static inline void set_stack_size_at_create(size_t value) {
1124 _stack_size_at_create = value;
1125 }
1126
1127 // Machine dependent stuff
1128 #include OS_CPU_HEADER(javaThread)
1129
1130 // JSR166 per-thread parker
1131 private:
1132 Parker _parker;
1133 public:
1134 Parker* parker() { return &_parker; }
1135
1136 public:
1137 // clearing/querying jni attach status
1138 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1139 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1140 inline void set_done_attaching_via_jni();
1141
1142 // Stack dump assistance:
1143 // Track the class we want to initialize but for which we have to wait
1144 // on its init_lock() because it is already being initialized.
1145 void set_class_to_be_initialized(InstanceKlass* k);
1146 InstanceKlass* class_to_be_initialized() const;
1147
1148 private:
1149 InstanceKlass* _class_to_be_initialized;
1150
1151 // java.lang.Thread.sleep support
1152 ParkEvent * _SleepEvent;
1153 public:
1154 bool sleep(jlong millis);
1155 bool sleep_nanos(jlong nanos);
1156
1157 // java.lang.Thread interruption support
1158 void interrupt();
1159 bool is_interrupted(bool clear_interrupted);
1160
1161 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1162 // the Java code in Object::wait which are not present in RawMonitorWait.
1163 bool get_and_clear_interrupted();
1164
1165 private:
1166 LockStack _lock_stack;
1167 OMCache _om_cache;
1168
1169 public:
1170 LockStack& lock_stack() { return _lock_stack; }
1171
1172 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1173 // Those offsets are used in code generators to access the LockStack that is embedded in this
1174 // JavaThread structure. Those accesses are relative to the current thread, which
1175 // is typically in a dedicated register.
1176 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1177 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1178
1179
1180 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); }
1181 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); }
1182
1183 void om_set_monitor_cache(ObjectMonitor* monitor);
1184 void om_clear_monitor_cache();
1185 ObjectMonitor* om_get_from_monitor_cache(oop obj);
1186
1187 static OopStorage* thread_oop_storage();
1188
1189 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1190
1191 // Helper function to create the java.lang.Thread object for a
1192 // VM-internal thread. The thread will have the given name and be
1193 // part of the System ThreadGroup.
1194 static Handle create_system_thread_object(const char* name, TRAPS);
1195
1196 // Helper function to start a VM-internal daemon thread.
1197 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1198 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1199 Handle thread_oop, ThreadPriority prio);
1200
1201 // Helper function to do vm_exit_on_initialization for osthread
1202 // resource allocation failure.
1203 static void vm_exit_on_osthread_failure(JavaThread* thread);
1204
1205 // Deferred OopHandle release support
1206 private:
1207 // List of OopHandles to be released - guarded by the Service_lock.
1208 static OopHandleList* _oop_handle_list;
1209 // Add our OopHandles to the list for the service thread to release.
1210 void add_oop_handles_for_release();
1211 // Called by the ServiceThread to release the OopHandles.
1212 static void release_oop_handles();
1213 // Called by the ServiceThread to poll if there are any OopHandles to release.
1214 // Called when holding the Service_lock.
1215 static bool has_oop_handles_to_release() {
1216 return _oop_handle_list != nullptr;
1217 }
1218 };
1219
1220 inline JavaThread* JavaThread::current_or_null() {
1221 Thread* current = Thread::current_or_null();
1222 return current != nullptr ? JavaThread::cast(current) : nullptr;
1223 }
1224
1225 class UnlockFlagSaver {
1226 private:
1227 JavaThread* _thread;
1228 bool _do_not_unlock;
1229 public:
1230 UnlockFlagSaver(JavaThread* t) {
1231 _thread = t;
1232 _do_not_unlock = t->do_not_unlock_if_synchronized();
1233 t->set_do_not_unlock_if_synchronized(false);
1234 }
1235 ~UnlockFlagSaver() {
1236 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1237 }
1238 };
1239
1240 class JNIHandleMark : public StackObj {
1241 JavaThread* _thread;
1242 public:
1243 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1244 thread->push_jni_handle_block();
1245 }
1246 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1247 };
1248
1249 #endif // SHARE_RUNTIME_JAVATHREAD_HPP