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 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
242 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
243 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
244 #ifdef ASSERT
245 // Debug support for checking if code allows safepoints or not.
246 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
247 // mutex, or blocking on an object synchronizer (Java locking).
248 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
249 // the above cases. The class NoSafepointVerifier is used to set this counter.
250 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
251
252 public:
253 void inc_no_safepoint_count() { _no_safepoint_count++; }
254 void dec_no_safepoint_count() { _no_safepoint_count--; }
255 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
256 #endif // ASSERT
257 public:
258 // These functions check conditions before possibly going to a safepoint.
259 // including NoSafepointVerifier.
260 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
261 void check_possible_safepoint() NOT_DEBUG_RETURN;
262
263 #ifdef ASSERT
264 private:
265 volatile uint64_t _visited_for_critical_count;
266
267 public:
268 void set_visited_for_critical_count(uint64_t safepoint_id) {
269 assert(_visited_for_critical_count == 0, "Must be reset before set");
270 assert((safepoint_id & 0x1) == 1, "Must be odd");
271 _visited_for_critical_count = safepoint_id;
272 }
273 void reset_visited_for_critical_count(uint64_t safepoint_id) {
274 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
275 _visited_for_critical_count = 0;
276 }
277 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
278 return _visited_for_critical_count == safepoint_id;
279 }
280 #endif // ASSERT
281
282 // JavaThread termination support
283 public:
284 enum TerminatedTypes {
285 _not_terminated = 0xDEAD - 3,
286 _thread_exiting, // JavaThread::exit() has been called for this thread
287 _thread_gc_barrier_detached, // thread's GC barrier has been detached
288 _thread_terminated, // JavaThread is removed from thread list
289 _vm_exited // JavaThread is still executing native code, but VM is terminated
290 // only VM_Exit can set _vm_exited
291 };
292
293 private:
294 // In general a JavaThread's _terminated field transitions as follows:
295 //
296 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
297 //
298 // _vm_exited is a special value to cover the case of a JavaThread
299 // executing native code after the VM itself is terminated.
300 //
301 // A JavaThread that fails to JNI attach has these _terminated field transitions:
302 // _not_terminated => _thread_terminated
303 //
304 volatile TerminatedTypes _terminated;
305
306 jint _in_deopt_handler; // count of deoptimization
307 // handlers thread is in
308 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
309 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
310 // never locked) when throwing an exception. Used by interpreter only.
311 #if INCLUDE_JVMTI
312 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
313 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
314 bool _is_in_tmp_VTMS_transition; // thread is in temporary virtual thread mount state transition
315 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
316 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers
317 #ifdef ASSERT
318 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
319 #endif
320 #endif
321
322 // JNI attach states:
323 enum JNIAttachStates {
324 _not_attaching_via_jni = 1, // thread is not attaching via JNI
325 _attaching_via_jni, // thread is attaching via JNI
326 _attached_via_jni // thread has attached via JNI
327 };
328
329 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
330 // A native thread that is attaching via JNI starts with a value
331 // of _attaching_via_jni and transitions to _attached_via_jni.
332 volatile JNIAttachStates _jni_attach_state;
333
334 // In scope of an InternalOOMEMark?
335 bool _is_in_internal_oome_mark;
336
337 #if INCLUDE_JVMCI
338 // The _pending_* fields below are used to communicate extra information
339 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
340
341 // Communicates the DeoptReason and DeoptAction of the uncommon trap
342 int _pending_deoptimization;
343
344 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
345 // before the monitor has been acquired.
346 bool _pending_monitorenter;
347
348 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
349 bool _pending_transfer_to_interpreter;
350
351 // An id of a speculation that JVMCI compiled code can use to further describe and
352 // uniquely identify the speculative optimization guarded by an uncommon trap.
353 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
354 jlong _pending_failed_speculation;
355
356 // These fields are mutually exclusive in terms of live ranges.
357 union {
358 // Communicates the pc at which the most recent implicit exception occurred
359 // from the signal handler to a deoptimization stub.
360 address _implicit_exception_pc;
361
362 // Communicates an alternative call target to an i2c stub from a JavaCall .
363 address _alternate_call_target;
364 } _jvmci;
365
366 // The JVMCIRuntime in a JVMCI shared library
367 JVMCIRuntime* _libjvmci_runtime;
368
369 // Support for high precision, thread sensitive counters in JVMCI compiled code.
370 jlong* _jvmci_counters;
371
372 // Fast thread locals for use by JVMCI
373 jlong _jvmci_reserved0;
374 jlong _jvmci_reserved1;
375 oop _jvmci_reserved_oop0;
376
377 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
378 // be kept alive
379 nmethod* _live_nmethod;
380
381 public:
382 static jlong* _jvmci_old_thread_counters;
383 static void collect_counters(jlong* array, int length);
384
385 bool resize_counters(int current_size, int new_size);
386
387 static bool resize_all_jvmci_counters(int new_size);
388
389 void set_jvmci_reserved_oop0(oop value) {
390 _jvmci_reserved_oop0 = value;
391 }
392
393 oop get_jvmci_reserved_oop0() {
394 return _jvmci_reserved_oop0;
395 }
396
397 void set_jvmci_reserved0(jlong value) {
398 _jvmci_reserved0 = value;
399 }
400
401 jlong get_jvmci_reserved0() {
402 return _jvmci_reserved0;
403 }
404
405 void set_jvmci_reserved1(jlong value) {
406 _jvmci_reserved1 = value;
407 }
408
409 jlong get_jvmci_reserved1() {
410 return _jvmci_reserved1;
411 }
412
413 void set_live_nmethod(nmethod* nm) {
414 assert(_live_nmethod == nullptr, "only one");
415 _live_nmethod = nm;
416 }
417
418 void clear_live_nmethod() {
419 _live_nmethod = nullptr;
420 }
421
422 private:
423 #endif // INCLUDE_JVMCI
424
425 StackOverflow _stack_overflow_state;
426
427 void pretouch_stack();
428
429 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
430 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
431 // code)
432 volatile oop _exception_oop; // Exception thrown in compiled code
433 volatile address _exception_pc; // PC where exception happened
434 volatile address _exception_handler_pc; // PC for handler of exception
435 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
436
437 private:
438 // support for JNI critical regions
439 jint _jni_active_critical; // count of entries into JNI critical region
440
441 // Checked JNI: function name requires exception check
442 char* _pending_jni_exception_check_fn;
443
444 // For deadlock detection.
445 int _depth_first_number;
446
447 // JVMTI PopFrame support
448 // This is set to popframe_pending to signal that top Java frame should be popped immediately
449 int _popframe_condition;
450
451 // If reallocation of scalar replaced objects fails, we throw OOM
452 // and during exception propagation, pop the top
453 // _frames_to_pop_failed_realloc frames, the ones that reference
454 // failed reallocations.
455 int _frames_to_pop_failed_realloc;
456
457 ContinuationEntry* _cont_entry;
458 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub frame inside the
459 // continuation that we know about
460 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
461
462 // It's signed for error detection.
463 intx _held_monitor_count; // used by continuations for fast lock detection
464 intx _jni_monitor_count;
465 ObjectMonitor* _unlocked_inflated_monitor;
466
467 private:
468
469 friend class VMThread;
470 friend class ThreadWaitTransition;
471 friend class VM_Exit;
472
473 // Stack watermark barriers.
474 StackWatermarks _stack_watermarks;
475
476 public:
477 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
478
479 public:
480 // Constructor
481 JavaThread(MemTag mem_tag = mtThread); // delegating constructor
482 JavaThread(ThreadFunction entry_point, size_t stack_size = 0, MemTag mem_tag = mtThread);
483 ~JavaThread();
484
485 // Factory method to create a new JavaThread whose attach state is "is attaching"
486 static JavaThread* create_attaching_thread();
487
488 #ifdef ASSERT
489 // verify this JavaThread hasn't be published in the Threads::list yet
490 void verify_not_published();
491 #endif // ASSERT
492
493 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
494
495 //JNI functiontable getter/setter for JVMTI jni function table interception API.
496 void set_jni_functions(struct JNINativeInterface_* functionTable) {
497 _jni_environment.functions = functionTable;
498 }
499 struct JNINativeInterface_* get_jni_functions() {
500 return (struct JNINativeInterface_ *)_jni_environment.functions;
501 }
502
503 // This function is called at thread creation to allow
504 // platform specific thread variables to be initialized.
505 void cache_global_variables();
506
507 // Executes Shutdown.shutdown()
508 void invoke_shutdown_hooks();
509
510 // Cleanup on thread exit
511 enum ExitType {
512 normal_exit,
513 jni_detach
514 };
515 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
516
517 void cleanup_failed_attach_current_thread(bool is_daemon);
518
519 // Testers
520 virtual bool is_Java_thread() const { return true; }
521 virtual bool can_call_java() const { return true; }
522
523 virtual bool is_active_Java_thread() const;
524
525 // Thread oop. threadObj() can be null for initial JavaThread
526 // (or for threads attached via JNI)
527 oop threadObj() const;
528 void set_threadOopHandles(oop p);
529 oop vthread() const;
530 void set_vthread(oop p);
531 oop scopedValueCache() const;
532 void set_scopedValueCache(oop p);
533 void clear_scopedValueBindings();
534 oop jvmti_vthread() const;
535 void set_jvmti_vthread(oop p);
536 oop vthread_or_thread() const;
537
538 // Prepare thread and add to priority queue. If a priority is
539 // not specified, use the priority of the thread object. Threads_lock
540 // must be held while this function is called.
541 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
542
543 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
544 address saved_exception_pc() { return _saved_exception_pc; }
545
546 ThreadFunction entry_point() const { return _entry_point; }
547
548 // Allocates a new Java level thread object for this thread. thread_name may be null.
549 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
550
551 // Last frame anchor routines
552
553 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
554
555 // last_Java_sp
556 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
557 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
558
559 // last_Java_pc
560
561 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
562
563 // Safepoint support
564 inline JavaThreadState thread_state() const;
565 inline void set_thread_state(JavaThreadState s);
566 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
567 inline ThreadSafepointState* safepoint_state() const;
568 inline void set_safepoint_state(ThreadSafepointState* state);
569 inline bool is_at_poll_safepoint();
570
571 // JavaThread termination and lifecycle support:
572 void smr_delete();
573 bool on_thread_list() const { return _on_thread_list; }
574 void set_on_thread_list() { _on_thread_list = true; }
575
576 // thread has called JavaThread::exit(), thread's GC barrier is detached
577 // or thread is terminated
578 bool is_exiting() const;
579 // thread's GC barrier is NOT detached and thread is NOT terminated
580 bool is_oop_safe() const;
581 // thread is terminated (no longer on the threads list); the thread must
582 // be protected by a ThreadsListHandle to avoid potential crashes.
583 bool check_is_terminated(TerminatedTypes l_terminated) const {
584 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
585 }
586 bool is_terminated() const;
587 void set_terminated(TerminatedTypes t);
588
589 void block_if_vm_exited();
590
591 bool doing_unsafe_access() { return _doing_unsafe_access; }
592 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
593
594 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
595 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
596
597 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
598
599 static ByteSize polling_word_offset() {
600 ByteSize offset = byte_offset_of(Thread, _poll_data) +
601 byte_offset_of(SafepointMechanism::ThreadData, _polling_word);
602 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
603 assert(in_bytes(offset) < 128, "Offset >= 128");
604 return offset;
605 }
606
607 static ByteSize polling_page_offset() {
608 ByteSize offset = byte_offset_of(Thread, _poll_data) +
609 byte_offset_of(SafepointMechanism::ThreadData, _polling_page);
610 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
611 assert(in_bytes(offset) < 128, "Offset >= 128");
612 return offset;
613 }
614
615 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
616
617 // Continuation support
618 ContinuationEntry* last_continuation() const { return _cont_entry; }
619 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
620 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
621 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
622 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
623 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
624 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
625
626 void inc_held_monitor_count(intx i = 1, bool jni = false);
627 void dec_held_monitor_count(intx i = 1, bool jni = false);
628
629 intx held_monitor_count() { return _held_monitor_count; }
630 intx jni_monitor_count() { return _jni_monitor_count; }
631 void clear_jni_monitor_count() { _jni_monitor_count = 0; }
632
633 // Support for SharedRuntime::monitor_exit_helper()
634 ObjectMonitor* unlocked_inflated_monitor() const { return _unlocked_inflated_monitor; }
635 void clear_unlocked_inflated_monitor() {
636 _unlocked_inflated_monitor = nullptr;
637 }
638
639 inline bool is_vthread_mounted() const;
640 inline const ContinuationEntry* vthread_continuation() const;
641
642 private:
643 DEBUG_ONLY(void verify_frame_info();)
644
645 // Support for thread handshake operations
646 HandshakeState _handshake;
647 public:
648 HandshakeState* handshake_state() { return &_handshake; }
649
650 // A JavaThread can always safely operate on it self and other threads
651 // can do it safely if they are the active handshaker.
652 bool is_handshake_safe_for(Thread* th) const {
653 return _handshake.active_handshaker() == th || this == th;
654 }
655
656 // Suspend/resume support for JavaThread
657 // higher-level suspension/resume logic called by the public APIs
658 bool java_suspend();
659 bool java_resume();
660 bool is_suspended() { return _handshake.is_suspended(); }
661
662 // Check for async exception in addition to safepoint.
663 static void check_special_condition_for_native_trans(JavaThread *thread);
664
665 // Synchronize with another thread that is deoptimizing objects of the
666 // current thread, i.e. reverts optimizations based on escape analysis.
667 void wait_for_object_deoptimization();
668
669 #if INCLUDE_JVMTI
670 inline void set_carrier_thread_suspended();
671 inline void clear_carrier_thread_suspended();
672
673 bool is_carrier_thread_suspended() const {
674 return _carrier_thread_suspended;
675 }
676
677 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
678 bool is_in_tmp_VTMS_transition() const { return _is_in_tmp_VTMS_transition; }
679 bool is_in_any_VTMS_transition() const { return _is_in_VTMS_transition || _is_in_tmp_VTMS_transition; }
680
681 void set_is_in_VTMS_transition(bool val);
682 void toggle_is_in_tmp_VTMS_transition() { _is_in_tmp_VTMS_transition = !_is_in_tmp_VTMS_transition; };
683
684 bool is_disable_suspend() const { return _is_disable_suspend; }
685 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
686
687 bool VTMS_transition_mark() const { return Atomic::load(&_VTMS_transition_mark); }
688 void set_VTMS_transition_mark(bool val) { Atomic::store(&_VTMS_transition_mark, val); }
689
690 #ifdef ASSERT
691 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
692 void set_is_VTMS_transition_disabler(bool val);
693 #endif
694 #endif
695
696 // Support for object deoptimization and JFR suspension
697 void handle_special_runtime_exit_condition();
698 bool has_special_runtime_exit_condition() {
699 return (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
700 }
701
702 // Stack-locking support (not for LM_LIGHTWEIGHT)
703 bool is_lock_owned(address adr) const;
704
705 // Accessors for vframe array top
706 // The linked list of vframe arrays are sorted on sp. This means when we
707 // unpack the head must contain the vframe array to unpack.
708 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
709 vframeArray* vframe_array_head() const { return _vframe_array_head; }
710
711 // Side structure for deferring update of java frame locals until deopt occurs
712 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
713 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
714
715 // These only really exist to make debugging deopt problems simpler
716
717 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
718 vframeArray* vframe_array_last() const { return _vframe_array_last; }
719
720 // The special resourceMark used during deoptimization
721
722 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
723 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
724
725 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
726 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
727
728 Method* callee_target() const { return _callee_target; }
729 void set_callee_target (Method* x) { _callee_target = x; }
730
731 // Oop results of vm runtime calls
732 oop vm_result() const { return _vm_result; }
733 void set_vm_result (oop x) { _vm_result = x; }
734
735 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
736
737 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
738 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
739
740 // Is thread in scope of an InternalOOMEMark?
741 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
742 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
743
744 #if INCLUDE_JVMCI
745 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
746 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
747 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
748 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
749 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
750 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
751 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
752
753 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
754 void set_libjvmci_runtime(JVMCIRuntime* rt) {
755 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
756 _libjvmci_runtime = rt;
757 }
758 #endif // INCLUDE_JVMCI
759
760 // Exception handling for compiled methods
761 oop exception_oop() const;
762 address exception_pc() const { return _exception_pc; }
763
764 void set_exception_oop(oop o);
765 void set_exception_pc(address a) { _exception_pc = a; }
766 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
767 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
768
769 void clear_exception_oop_and_pc() {
770 set_exception_oop(nullptr);
771 set_exception_pc(nullptr);
772 }
773
774 // Check if address is in the usable part of the stack (excludes protected
775 // guard pages). Can be applied to any thread and is an approximation for
776 // using is_in_live_stack when the query has to happen from another thread.
777 bool is_in_usable_stack(address adr) const {
778 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
779 }
780
781 // Misc. accessors/mutators
782 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
783
784 // For assembly stub generation
785 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
786 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
787 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
788 static ByteSize pending_jni_exception_check_fn_offset() {
789 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
790 }
791 static ByteSize last_Java_sp_offset() {
792 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
793 }
794 static ByteSize last_Java_pc_offset() {
795 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
796 }
797 static ByteSize frame_anchor_offset() {
798 return byte_offset_of(JavaThread, _anchor);
799 }
800 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
801 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
802 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
803 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
804 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
805 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
806 #if INCLUDE_JVMCI
807 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
808 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
809 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
810 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
811 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
812 #endif // INCLUDE_JVMCI
813 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
814 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
815 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
816 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
817
818 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
819
820 // StackOverflow offsets
821 static ByteSize stack_overflow_limit_offset() {
822 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
823 }
824 static ByteSize stack_guard_state_offset() {
825 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
826 }
827 static ByteSize reserved_stack_activation_offset() {
828 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
829 }
830 static ByteSize shadow_zone_safe_limit() {
831 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
832 }
833 static ByteSize shadow_zone_growth_watermark() {
834 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
835 }
836
837 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
838
839 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
840 static ByteSize should_post_on_exceptions_flag_offset() {
841 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
842 }
843 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
844 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
845
846 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
847 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
848 static ByteSize held_monitor_count_offset() { return byte_offset_of(JavaThread, _held_monitor_count); }
849 static ByteSize jni_monitor_count_offset() { return byte_offset_of(JavaThread, _jni_monitor_count); }
850 static ByteSize unlocked_inflated_monitor_offset() { return byte_offset_of(JavaThread, _unlocked_inflated_monitor); }
851
852 #if INCLUDE_JVMTI
853 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); }
854 static ByteSize is_in_tmp_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_tmp_VTMS_transition); }
855 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
856 #endif
857
858 // Returns the jni environment for this thread
859 JNIEnv* jni_environment() { return &_jni_environment; }
860
861 // Returns the current thread as indicated by the given JNIEnv.
862 // We don't assert it is Thread::current here as that is done at the
863 // external JNI entry points where the JNIEnv is passed into the VM.
864 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
865 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
866 // We can't normally get here in a thread that has completed its
867 // execution and so "is_terminated", except when the call is from
868 // AsyncGetCallTrace, which can be triggered by a signal at any point in
869 // a thread's lifecycle. A thread is also considered terminated if the VM
870 // has exited, so we have to check this and block in case this is a daemon
871 // thread returning to the VM (the JNI DirectBuffer entry points rely on
872 // this).
873 if (current->is_terminated()) {
874 current->block_if_vm_exited();
875 }
876 return current;
877 }
878
879 // JNI critical regions. These can nest.
880 bool in_critical() { return _jni_active_critical > 0; }
881 bool in_last_critical() { return _jni_active_critical == 1; }
882 inline void enter_critical();
883 void exit_critical() {
884 assert(Thread::current() == this, "this must be current thread");
885 _jni_active_critical--;
886 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
887 }
888
889 // Checked JNI: is the programmer required to check for exceptions, if so specify
890 // which function name. Returning to a Java frame should implicitly clear the
891 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
892 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
893 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
894 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
895 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
896 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
897 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
898
899 // For deadlock detection
900 int depth_first_number() { return _depth_first_number; }
901 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
902
903 public:
904 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
905 void inc_in_deopt_handler() { _in_deopt_handler++; }
906 void dec_in_deopt_handler() {
907 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
908 if (_in_deopt_handler > 0) { // robustness
909 _in_deopt_handler--;
910 }
911 }
912
913 private:
914 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
915
916 // factor out low-level mechanics for use in both normal and error cases
917 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
918
919 public:
920
921 // Frame iteration; calls the function f for all frames on the stack
922 void frames_do(void f(frame*, const RegisterMap*));
923
924 // Memory operations
925 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
926 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
927
928 // GC operations
929 virtual void nmethods_do(NMethodClosure* cf);
930
931 // RedefineClasses Support
932 void metadata_do(MetadataClosure* f);
933
934 // Debug method asserting thread states are correct during a handshake operation.
935 DEBUG_ONLY(void verify_states_for_handshake();)
936
937 // Misc. operations
938 const char* name() const;
939 const char* name_raw() const;
940 const char* type_name() const { return "JavaThread"; }
941 static const char* name_for(oop thread_obj);
942
943 void print_on(outputStream* st, bool print_extended_info) const;
944 void print_on(outputStream* st) const { print_on(st, false); }
945 void print() const;
946 void print_thread_state_on(outputStream*) const;
947 void print_on_error(outputStream* st, char* buf, int buflen) const;
948 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
949 void verify();
950
951 // Accessing frames
952 frame last_frame() {
953 _anchor.make_walkable();
954 return pd_last_frame();
955 }
956 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
957
958 frame carrier_last_frame(RegisterMap* reg_map);
959 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
960
961 frame vthread_last_frame();
962 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
963
964 frame platform_thread_last_frame(RegisterMap* reg_map);
965 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
966 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
967 }
968
969 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
970
971 // Returns method at 'depth' java or native frames down the stack
972 // Used for security checks
973 Klass* security_get_caller_class(int depth);
974
975 // Print stack trace in external format
976 // These variants print carrier/platform thread information only.
977 void print_stack_on(outputStream* st);
978 void print_stack() { print_stack_on(tty); }
979 // This prints the currently mounted virtual thread.
980 void print_vthread_stack_on(outputStream* st);
981 // This prints the active stack: either carrier/platform or virtual.
982 void print_active_stack_on(outputStream* st);
983 // Print current stack trace for checked JNI warnings and JNI fatal errors.
984 // This is the external format from above, but selecting the platform
985 // or vthread as applicable.
986 void print_jni_stack();
987
988 // Print stack traces in various internal formats
989 void trace_stack() PRODUCT_RETURN;
990 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
991 void trace_frames() PRODUCT_RETURN;
992
993 // Print an annotated view of the stack frames
994 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
995 void validate_frame_layout() {
996 print_frame_layout(0, true);
997 }
998
999 // Function for testing deoptimization
1000 void deoptimize();
1001 void make_zombies();
1002
1003 void deoptimize_marked_methods();
1004
1005 public:
1006 // Returns the running thread as a JavaThread
1007 static JavaThread* current() {
1008 return JavaThread::cast(Thread::current());
1009 }
1010
1011 // Returns the current thread as a JavaThread, or nullptr if not attached
1012 static inline JavaThread* current_or_null();
1013
1014 // Casts
1015 static JavaThread* cast(Thread* t) {
1016 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
1017 return static_cast<JavaThread*>(t);
1018 }
1019
1020 static const JavaThread* cast(const Thread* t) {
1021 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1022 return static_cast<const JavaThread*>(t);
1023 }
1024
1025 // Returns the active Java thread. Do not use this if you know you are calling
1026 // from a JavaThread, as it's slower than JavaThread::current. If called from
1027 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1028 // operation. You may not want that either.
1029 static JavaThread* active();
1030
1031 protected:
1032 virtual void pre_run();
1033 virtual void run();
1034 void thread_main_inner();
1035 virtual void post_run();
1036
1037 public:
1038 // Thread local information maintained by JVMTI.
1039 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1040 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1041 // getter is used to get this JavaThread's JvmtiThreadState if it has
1042 // one which means null can be returned. JvmtiThreadState::state_for()
1043 // is used to get the specified JavaThread's JvmtiThreadState if it has
1044 // one or it allocates a new JvmtiThreadState for the JavaThread and
1045 // returns it. JvmtiThreadState::state_for() will return null only if
1046 // the specified JavaThread is exiting.
1047 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1048 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1049
1050 #if INCLUDE_JVMTI
1051 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1052 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1053 #endif
1054
1055 // JVMTI PopFrame support
1056 // Setting and clearing popframe_condition
1057 // All of these enumerated values are bits. popframe_pending
1058 // indicates that a PopFrame() has been requested and not yet been
1059 // completed. popframe_processing indicates that that PopFrame() is in
1060 // the process of being completed. popframe_force_deopt_reexecution_bit
1061 // indicates that special handling is required when returning to a
1062 // deoptimized caller.
1063 enum PopCondition {
1064 popframe_inactive = 0x00,
1065 popframe_pending_bit = 0x01,
1066 popframe_processing_bit = 0x02,
1067 popframe_force_deopt_reexecution_bit = 0x04
1068 };
1069 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1070 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1071 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1072 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1073 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1074 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1075 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1076
1077 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1078 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1079 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1080
1081 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1082 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1083 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1084
1085 private:
1086 // Saved incoming arguments to popped frame.
1087 // Used only when popped interpreted frame returns to deoptimized frame.
1088 void* _popframe_preserved_args;
1089 int _popframe_preserved_args_size;
1090
1091 public:
1092 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1093 void* popframe_preserved_args();
1094 ByteSize popframe_preserved_args_size();
1095 WordSize popframe_preserved_args_size_in_words();
1096 void popframe_free_preserved_args();
1097
1098
1099 private:
1100 JvmtiThreadState *_jvmti_thread_state;
1101
1102 // Used by the interpreter in fullspeed mode for frame pop, method
1103 // entry, method exit and single stepping support. This field is
1104 // only set to non-zero at a safepoint or using a direct handshake
1105 // (see EnterInterpOnlyModeClosure).
1106 // It can be set to zero asynchronously to this threads execution (i.e., without
1107 // safepoint/handshake or a lock) so we have to be very careful.
1108 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1109 int _interp_only_mode;
1110
1111 public:
1112 // used by the interpreter for fullspeed debugging support (see above)
1113 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1114 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1115 int get_interp_only_mode() { return _interp_only_mode; }
1116 int set_interp_only_mode(int val) { return _interp_only_mode = val; }
1117 void increment_interp_only_mode() { ++_interp_only_mode; }
1118 void decrement_interp_only_mode() { --_interp_only_mode; }
1119
1120 // support for cached flag that indicates whether exceptions need to be posted for this thread
1121 // if this is false, we can avoid deoptimizing when events are thrown
1122 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1123 private:
1124 int _should_post_on_exceptions_flag;
1125
1126 public:
1127 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1128
1129 private:
1130 ThreadStatistics *_thread_stat;
1131
1132 public:
1133 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1134
1135 // Return a blocker object for which this thread is blocked parking.
1136 oop current_park_blocker();
1137
1138 private:
1139 static size_t _stack_size_at_create;
1140
1141 public:
1142 static inline size_t stack_size_at_create(void) {
1143 return _stack_size_at_create;
1144 }
1145 static inline void set_stack_size_at_create(size_t value) {
1146 _stack_size_at_create = value;
1147 }
1148
1149 // Machine dependent stuff
1150 #include OS_CPU_HEADER(javaThread)
1151
1152 // JSR166 per-thread parker
1153 private:
1154 Parker _parker;
1155 public:
1156 Parker* parker() { return &_parker; }
1157
1158 public:
1159 // clearing/querying jni attach status
1160 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1161 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1162 inline void set_done_attaching_via_jni();
1163
1164 // Stack dump assistance:
1165 // Track the class we want to initialize but for which we have to wait
1166 // on its init_lock() because it is already being initialized.
1167 void set_class_to_be_initialized(InstanceKlass* k);
1168 InstanceKlass* class_to_be_initialized() const;
1169
1170 private:
1171 InstanceKlass* _class_to_be_initialized;
1172
1173 // java.lang.Thread.sleep support
1174 ParkEvent * _SleepEvent;
1175 public:
1176 bool sleep(jlong millis);
1177 bool sleep_nanos(jlong nanos);
1178
1179 // java.lang.Thread interruption support
1180 void interrupt();
1181 bool is_interrupted(bool clear_interrupted);
1182
1183 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1184 // the Java code in Object::wait which are not present in RawMonitorWait.
1185 bool get_and_clear_interrupted();
1186
1187 private:
1188 LockStack _lock_stack;
1189 OMCache _om_cache;
1190
1191 public:
1192 LockStack& lock_stack() { return _lock_stack; }
1193
1194 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1195 // Those offsets are used in code generators to access the LockStack that is embedded in this
1196 // JavaThread structure. Those accesses are relative to the current thread, which
1197 // is typically in a dedicated register.
1198 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1199 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1200
1201 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); }
1202 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); }
1203
1204 void om_set_monitor_cache(ObjectMonitor* monitor);
1205 void om_clear_monitor_cache();
1206 ObjectMonitor* om_get_from_monitor_cache(oop obj);
1207
1208 static OopStorage* thread_oop_storage();
1209
1210 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1211
1212 // Helper function to create the java.lang.Thread object for a
1213 // VM-internal thread. The thread will have the given name and be
1214 // part of the System ThreadGroup.
1215 static Handle create_system_thread_object(const char* name, TRAPS);
1216
1217 // Helper function to start a VM-internal daemon thread.
1218 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1219 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1220 Handle thread_oop, ThreadPriority prio);
1221
1222 // Helper function to do vm_exit_on_initialization for osthread
1223 // resource allocation failure.
1224 static void vm_exit_on_osthread_failure(JavaThread* thread);
1225
1226 // Deferred OopHandle release support
1227 private:
1228 // List of OopHandles to be released - guarded by the Service_lock.
1229 static OopHandleList* _oop_handle_list;
1230 // Add our OopHandles to the list for the service thread to release.
1231 void add_oop_handles_for_release();
1232 // Called by the ServiceThread to release the OopHandles.
1233 static void release_oop_handles();
1234 // Called by the ServiceThread to poll if there are any OopHandles to release.
1235 // Called when holding the Service_lock.
1236 static bool has_oop_handles_to_release() {
1237 return _oop_handle_list != nullptr;
1238 }
1239 };
1240
1241 inline JavaThread* JavaThread::current_or_null() {
1242 Thread* current = Thread::current_or_null();
1243 return current != nullptr ? JavaThread::cast(current) : nullptr;
1244 }
1245
1246 class UnlockFlagSaver {
1247 private:
1248 JavaThread* _thread;
1249 bool _do_not_unlock;
1250 public:
1251 UnlockFlagSaver(JavaThread* t) {
1252 _thread = t;
1253 _do_not_unlock = t->do_not_unlock_if_synchronized();
1254 t->set_do_not_unlock_if_synchronized(false);
1255 }
1256 ~UnlockFlagSaver() {
1257 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1258 }
1259 };
1260
1261 class JNIHandleMark : public StackObj {
1262 JavaThread* _thread;
1263 public:
1264 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1265 thread->push_jni_handle_block();
1266 }
1267 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1268 };
1269
1270 #endif // SHARE_RUNTIME_JAVATHREAD_HPP