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/continuationEntry.hpp"
34 #include "runtime/frame.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handshake.hpp"
37 #include "runtime/javaFrameAnchor.hpp"
38 #include "runtime/lockStack.hpp"
39 #include "runtime/park.hpp"
40 #include "runtime/safepointMechanism.hpp"
41 #include "runtime/stackWatermarkSet.hpp"
42 #include "runtime/stackOverflow.hpp"
43 #include "runtime/thread.hpp"
44 #include "runtime/threadHeapSampler.hpp"
45 #include "runtime/threadIdentifier.hpp"
46 #include "runtime/threadStatisticalInfo.hpp"
47 #include "utilities/exceptions.hpp"
48 #include "utilities/globalDefinitions.hpp"
49 #include "utilities/macros.hpp"
50 #if INCLUDE_JFR
51 #include "jfr/support/jfrThreadExtension.hpp"
52 #endif
53
54 class AsyncExceptionHandshake;
55 class DeoptResourceMark;
56 class InternalOOMEMark;
57 class JNIHandleBlock;
58 class JVMCIRuntime;
59
60 class JvmtiDeferredUpdates;
61 class JvmtiSampledObjectAllocEventCollector;
62 class JvmtiThreadState;
63
64 class Metadata;
65 class ObjectMonitor;
66 class OopHandleList;
67 class OopStorage;
68 class OSThread;
69
70 class ThreadsList;
71 class ThreadSafepointState;
72 class ThreadStatistics;
73
74 class vframeArray;
75 class vframe;
76 class javaVFrame;
77
78 class JavaThread;
79 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
80
81 class JavaThread: public Thread {
82 friend class VMStructs;
83 friend class JVMCIVMStructs;
84 friend class WhiteBox;
85 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
86 friend class HandshakeState;
87 friend class Continuation;
88 friend class Threads;
89 friend class ServiceThread; // for deferred OopHandle release access
90 private:
91 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
92
93 // All references to Java objects managed via OopHandles. These
94 // have to be released by the ServiceThread after the JavaThread has
95 // terminated - see add_oop_handles_for_release().
96 OopHandle _threadObj; // The Java level thread object
97 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj
98 OopHandle _jvmti_vthread;
99 OopHandle _scopedValueCache;
100
101 static OopStorage* _thread_oop_storage;
102
103 #ifdef ASSERT
104 private:
105 int _java_call_counter;
106
107 public:
108 int java_call_counter() { return _java_call_counter; }
109 void inc_java_call_counter() { _java_call_counter++; }
110 void dec_java_call_counter() {
111 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
112 _java_call_counter--;
113 }
114 private: // restore original namespace restriction
115 #endif // ifdef ASSERT
116
117 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
118
119 ThreadFunction _entry_point;
120
121 JNIEnv _jni_environment;
122
123 // Deopt support
124 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
125
126 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
127 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
128 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
129 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
130 // will be carried out as soon as possible which, in most cases, is just before deoptimization of
131 // the frame, when control returns to it.
132 JvmtiDeferredUpdates* _jvmti_deferred_updates;
133
134 // Handshake value for fixing 6243940. We need a place for the i2c
135 // adapter to store the callee Method*. This value is NEVER live
136 // across a gc point so it does NOT have to be gc'd
137 // The handshake is open ended since we can't be certain that it will
138 // be nulled. This is because we rarely ever see the race and end up
139 // in handle_wrong_method which is the backend of the handshake. See
140 // code in i2c adapters and handle_wrong_method.
141
142 Method* _callee_target;
143
144 // Used to pass back results to the interpreter or generated code running Java code.
145 oop _vm_result; // oop result is GC-preserved
146 Metadata* _vm_result_2; // non-oop result
147
148 // See ReduceInitialCardMarks: this holds the precise space interval of
149 // the most recent slow path allocation for which compiled code has
150 // elided card-marks for performance along the fast-path.
151 MemRegion _deferred_card_mark;
152
153 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock
154 bool _current_pending_monitor_is_from_java; // locking is from Java code
155 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait()
156
157 // Active_handles points to a block of handles
158 JNIHandleBlock* _active_handles;
159
160 // One-element thread local free list
161 JNIHandleBlock* _free_handle_block;
162
163 // ID used as owner for inflated monitors. Same as the j.l.Thread.tid of the
164 // current _vthread object, except during creation of the primordial and JNI
165 // attached thread cases where this field can have a temporary value. Also,
166 // calls to VirtualThread.switchToCarrierThread will temporarily change _vthread
167 // to refer to the carrier while preserving the j.l.Thread.tid of the virtual
168 // thread in this field.
169 int64_t _lock_id;
170
171 public:
172 void set_lock_id(int64_t tid) {
173 assert(tid >= ThreadIdentifier::initial() && tid < ThreadIdentifier::current(), "invalid tid");
174 _lock_id = tid;
175 }
176 int64_t lock_id() const { return _lock_id; }
177
178 // For tracking the heavyweight monitor the thread is pending on.
179 ObjectMonitor* current_pending_monitor() {
180 // Use Atomic::load() to prevent data race between concurrent modification and
181 // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
182 // Especially, reloading pointer from thread after null check must be prevented.
183 return Atomic::load(&_current_pending_monitor);
184 }
185 void set_current_pending_monitor(ObjectMonitor* monitor) {
186 Atomic::store(&_current_pending_monitor, monitor);
187 }
188 void set_current_pending_monitor_is_from_java(bool from_java) {
189 _current_pending_monitor_is_from_java = from_java;
190 }
191 bool current_pending_monitor_is_from_java() {
192 return _current_pending_monitor_is_from_java;
193 }
194 ObjectMonitor* current_waiting_monitor() {
195 // See the comment in current_pending_monitor() above.
196 return Atomic::load(&_current_waiting_monitor);
197 }
198 void set_current_waiting_monitor(ObjectMonitor* monitor) {
199 Atomic::store(&_current_waiting_monitor, monitor);
200 }
201
202 // JNI handle support
203 JNIHandleBlock* active_handles() const { return _active_handles; }
204 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
205 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
206 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
207
208 void push_jni_handle_block();
209 void pop_jni_handle_block();
210
211 private:
212 enum SuspendFlags {
213 // NOTE: avoid using the sign-bit as cc generates different test code
214 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
215 _trace_flag = 0x00000004U, // call tracing backend
216 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
217 };
218
219 // various suspension related flags - atomically updated
220 volatile uint32_t _suspend_flags;
221
222 inline void set_suspend_flag(SuspendFlags f);
223 inline void clear_suspend_flag(SuspendFlags f);
224
225 public:
226 inline void set_trace_flag();
227 inline void clear_trace_flag();
228 inline void set_obj_deopt_flag();
229 inline void clear_obj_deopt_flag();
230 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
231 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; }
232
233 // Asynchronous exception support
234 private:
235 friend class InstallAsyncExceptionHandshake;
236 friend class AsyncExceptionHandshake;
237 friend class HandshakeState;
238
239 void handle_async_exception(oop java_throwable);
240 public:
241 void install_async_exception(AsyncExceptionHandshake* aec = nullptr);
242 bool has_async_exception_condition();
243 inline void set_pending_unsafe_access_error();
244 static void send_async_exception(JavaThread* jt, oop java_throwable);
245
246 class NoAsyncExceptionDeliveryMark : public StackObj {
247 friend JavaThread;
248 JavaThread *_target;
249 inline NoAsyncExceptionDeliveryMark(JavaThread *t);
250 inline ~NoAsyncExceptionDeliveryMark();
251 };
252
253 // Safepoint support
254 public: // Expose _thread_state for SafeFetchInt()
255 volatile JavaThreadState _thread_state;
256 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
257 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
258 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
259 #ifdef ASSERT
260 // Debug support for checking if code allows safepoints or not.
261 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
262 // mutex, or blocking on an object synchronizer (Java locking).
263 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
264 // the above cases. The class NoSafepointVerifier is used to set this counter.
265 int _no_safepoint_count; // If 0, thread allow a safepoint to happen
266
267 public:
268 void inc_no_safepoint_count() { _no_safepoint_count++; }
269 void dec_no_safepoint_count() { _no_safepoint_count--; }
270 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; }
271 #endif // ASSERT
272 public:
273 // These functions check conditions before possibly going to a safepoint.
274 // including NoSafepointVerifier.
275 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
276 void check_possible_safepoint() NOT_DEBUG_RETURN;
277
278 #ifdef ASSERT
279 private:
280 volatile uint64_t _visited_for_critical_count;
281
282 public:
283 void set_visited_for_critical_count(uint64_t safepoint_id) {
284 assert(_visited_for_critical_count == 0, "Must be reset before set");
285 assert((safepoint_id & 0x1) == 1, "Must be odd");
286 _visited_for_critical_count = safepoint_id;
287 }
288 void reset_visited_for_critical_count(uint64_t safepoint_id) {
289 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
290 _visited_for_critical_count = 0;
291 }
292 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
293 return _visited_for_critical_count == safepoint_id;
294 }
295 #endif // ASSERT
296
297 // JavaThread termination support
298 public:
299 enum TerminatedTypes {
300 _not_terminated = 0xDEAD - 3,
301 _thread_exiting, // JavaThread::exit() has been called for this thread
302 _thread_gc_barrier_detached, // thread's GC barrier has been detached
303 _thread_terminated, // JavaThread is removed from thread list
304 _vm_exited // JavaThread is still executing native code, but VM is terminated
305 // only VM_Exit can set _vm_exited
306 };
307
308 private:
309 // In general a JavaThread's _terminated field transitions as follows:
310 //
311 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated
312 //
313 // _vm_exited is a special value to cover the case of a JavaThread
314 // executing native code after the VM itself is terminated.
315 //
316 // A JavaThread that fails to JNI attach has these _terminated field transitions:
317 // _not_terminated => _thread_terminated
318 //
319 volatile TerminatedTypes _terminated;
320
321 jint _in_deopt_handler; // count of deoptimization
322 // handlers thread is in
323 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
324 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
325 // never locked) when throwing an exception. Used by interpreter only.
326 #if INCLUDE_JVMTI
327 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended
328 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition
329 bool _is_in_tmp_VTMS_transition; // thread is in temporary virtual thread mount state transition
330 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only
331 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers
332 bool _pending_jvmti_unmount_event; // When preempting we post unmount event at unmount end rather than start
333 bool _on_monitor_waited_event; // Avoid callee arg processing for enterSpecial when posting waited event
334 ObjectMonitor* _contended_entered_monitor; // Monitor por pending monitor_contended_entered callback
335 #ifdef ASSERT
336 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions
337 #endif
338 #endif
339
340 // JNI attach states:
341 enum JNIAttachStates {
342 _not_attaching_via_jni = 1, // thread is not attaching via JNI
343 _attaching_via_jni, // thread is attaching via JNI
344 _attached_via_jni // thread has attached via JNI
345 };
346
347 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
348 // A native thread that is attaching via JNI starts with a value
349 // of _attaching_via_jni and transitions to _attached_via_jni.
350 volatile JNIAttachStates _jni_attach_state;
351
352 // In scope of an InternalOOMEMark?
353 bool _is_in_internal_oome_mark;
354
355 #if INCLUDE_JVMCI
356 // The _pending_* fields below are used to communicate extra information
357 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
358
359 // Communicates the DeoptReason and DeoptAction of the uncommon trap
360 int _pending_deoptimization;
361
362 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
363 // before the monitor has been acquired.
364 bool _pending_monitorenter;
365
366 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
367 bool _pending_transfer_to_interpreter;
368
369 // An id of a speculation that JVMCI compiled code can use to further describe and
370 // uniquely identify the speculative optimization guarded by an uncommon trap.
371 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
372 jlong _pending_failed_speculation;
373
374 // These fields are mutually exclusive in terms of live ranges.
375 union {
376 // Communicates the pc at which the most recent implicit exception occurred
377 // from the signal handler to a deoptimization stub.
378 address _implicit_exception_pc;
379
380 // Communicates an alternative call target to an i2c stub from a JavaCall .
381 address _alternate_call_target;
382 } _jvmci;
383
384 // The JVMCIRuntime in a JVMCI shared library
385 JVMCIRuntime* _libjvmci_runtime;
386
387 // Support for high precision, thread sensitive counters in JVMCI compiled code.
388 jlong* _jvmci_counters;
389
390 // Fast thread locals for use by JVMCI
391 jlong _jvmci_reserved0;
392 jlong _jvmci_reserved1;
393 oop _jvmci_reserved_oop0;
394
395 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can
396 // be kept alive
397 nmethod* _live_nmethod;
398
399 public:
400 static jlong* _jvmci_old_thread_counters;
401 static void collect_counters(jlong* array, int length);
402
403 bool resize_counters(int current_size, int new_size);
404
405 static bool resize_all_jvmci_counters(int new_size);
406
407 void set_jvmci_reserved_oop0(oop value) {
408 _jvmci_reserved_oop0 = value;
409 }
410
411 oop get_jvmci_reserved_oop0() {
412 return _jvmci_reserved_oop0;
413 }
414
415 void set_jvmci_reserved0(jlong value) {
416 _jvmci_reserved0 = value;
417 }
418
419 jlong get_jvmci_reserved0() {
420 return _jvmci_reserved0;
421 }
422
423 void set_jvmci_reserved1(jlong value) {
424 _jvmci_reserved1 = value;
425 }
426
427 jlong get_jvmci_reserved1() {
428 return _jvmci_reserved1;
429 }
430
431 void set_live_nmethod(nmethod* nm) {
432 assert(_live_nmethod == nullptr, "only one");
433 _live_nmethod = nm;
434 }
435
436 void clear_live_nmethod() {
437 _live_nmethod = nullptr;
438 }
439
440 private:
441 #endif // INCLUDE_JVMCI
442
443 StackOverflow _stack_overflow_state;
444
445 void pretouch_stack();
446
447 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
448 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
449 // code)
450 volatile oop _exception_oop; // Exception thrown in compiled code
451 volatile address _exception_pc; // PC where exception happened
452 volatile address _exception_handler_pc; // PC for handler of exception
453 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
454
455 private:
456 // support for JNI critical regions
457 jint _jni_active_critical; // count of entries into JNI critical region
458
459 // Checked JNI: function name requires exception check
460 char* _pending_jni_exception_check_fn;
461
462 // For deadlock detection.
463 int _depth_first_number;
464
465 // JVMTI PopFrame support
466 // This is set to popframe_pending to signal that top Java frame should be popped immediately
467 int _popframe_condition;
468
469 // If reallocation of scalar replaced objects fails, we throw OOM
470 // and during exception propagation, pop the top
471 // _frames_to_pop_failed_realloc frames, the ones that reference
472 // failed reallocations.
473 int _frames_to_pop_failed_realloc;
474
475 ContinuationEntry* _cont_entry;
476 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub frame inside the
477 // continuation that we know about
478 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI)
479
480 // It's signed for error detection.
481 intx _held_monitor_count; // used by continuations for fast lock detection
482 intx _jni_monitor_count;
483 ObjectMonitor* _unlocked_inflated_monitor;
484
485 // This is the field we poke in the interpreter and native
486 // wrapper (Object.wait) to check for preemption.
487 address _preempt_alternate_return;
488 // When preempting on monitorenter we could have acquired the
489 // monitor after freezing all vthread frames. In that case we
490 // set this field so that in the preempt stub we call thaw again
491 // instead of unmounting.
492 bool _preemption_cancelled;
493 // For Object.wait() we set this field to know if we need to
494 // throw IE at the end of thawing before returning to Java.
495 bool _pending_interrupted_exception;
496
497 public:
498 bool preemption_cancelled() { return _preemption_cancelled; }
499 void set_preemption_cancelled(bool b) { _preemption_cancelled = b; }
500
501 bool pending_interrupted_exception() { return _pending_interrupted_exception; }
502 void set_pending_interrupted_exception(bool b) { _pending_interrupted_exception = b; }
503
504 bool preempting() { return _preempt_alternate_return != nullptr; }
505 void set_preempt_alternate_return(address val) { _preempt_alternate_return = val; }
506
507 private:
508
509 friend class VMThread;
510 friend class ThreadWaitTransition;
511 friend class VM_Exit;
512
513 // Stack watermark barriers.
514 StackWatermarks _stack_watermarks;
515
516 public:
517 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
518
519 public:
520 // Constructor
521 JavaThread(MemTag mem_tag = mtThread); // delegating constructor
522 JavaThread(ThreadFunction entry_point, size_t stack_size = 0, MemTag mem_tag = mtThread);
523 ~JavaThread();
524
525 // Factory method to create a new JavaThread whose attach state is "is attaching"
526 static JavaThread* create_attaching_thread();
527
528 #ifdef ASSERT
529 // verify this JavaThread hasn't be published in the Threads::list yet
530 void verify_not_published();
531 #endif // ASSERT
532
533 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
534
535 //JNI functiontable getter/setter for JVMTI jni function table interception API.
536 void set_jni_functions(struct JNINativeInterface_* functionTable) {
537 _jni_environment.functions = functionTable;
538 }
539 struct JNINativeInterface_* get_jni_functions() {
540 return (struct JNINativeInterface_ *)_jni_environment.functions;
541 }
542
543 // This function is called at thread creation to allow
544 // platform specific thread variables to be initialized.
545 void cache_global_variables();
546
547 // Executes Shutdown.shutdown()
548 void invoke_shutdown_hooks();
549
550 // Cleanup on thread exit
551 enum ExitType {
552 normal_exit,
553 jni_detach
554 };
555 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
556
557 void cleanup_failed_attach_current_thread(bool is_daemon);
558
559 // Testers
560 virtual bool is_Java_thread() const { return true; }
561 virtual bool can_call_java() const { return true; }
562
563 virtual bool is_active_Java_thread() const;
564
565 // Thread oop. threadObj() can be null for initial JavaThread
566 // (or for threads attached via JNI)
567 oop threadObj() const;
568 void set_threadOopHandles(oop p);
569 oop vthread() const;
570 void set_vthread(oop p);
571 oop scopedValueCache() const;
572 void set_scopedValueCache(oop p);
573 void clear_scopedValueBindings();
574 oop jvmti_vthread() const;
575 void set_jvmti_vthread(oop p);
576 oop vthread_or_thread() const;
577
578 // Prepare thread and add to priority queue. If a priority is
579 // not specified, use the priority of the thread object. Threads_lock
580 // must be held while this function is called.
581 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
582
583 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
584 address saved_exception_pc() { return _saved_exception_pc; }
585
586 ThreadFunction entry_point() const { return _entry_point; }
587
588 // Allocates a new Java level thread object for this thread. thread_name may be null.
589 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
590
591 // Last frame anchor routines
592
593 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
594
595 // last_Java_sp
596 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
597 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
598
599 // last_Java_pc
600
601 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
602
603 // Safepoint support
604 inline JavaThreadState thread_state() const;
605 inline void set_thread_state(JavaThreadState s);
606 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
607 inline ThreadSafepointState* safepoint_state() const;
608 inline void set_safepoint_state(ThreadSafepointState* state);
609 inline bool is_at_poll_safepoint();
610
611 // JavaThread termination and lifecycle support:
612 void smr_delete();
613 bool on_thread_list() const { return _on_thread_list; }
614 void set_on_thread_list() { _on_thread_list = true; }
615
616 // thread has called JavaThread::exit(), thread's GC barrier is detached
617 // or thread is terminated
618 bool is_exiting() const;
619 // thread's GC barrier is NOT detached and thread is NOT terminated
620 bool is_oop_safe() const;
621 // thread is terminated (no longer on the threads list); the thread must
622 // be protected by a ThreadsListHandle to avoid potential crashes.
623 bool check_is_terminated(TerminatedTypes l_terminated) const {
624 return l_terminated == _thread_terminated || l_terminated == _vm_exited;
625 }
626 bool is_terminated() const;
627 void set_terminated(TerminatedTypes t);
628
629 void block_if_vm_exited();
630
631 bool doing_unsafe_access() { return _doing_unsafe_access; }
632 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
633
634 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
635 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
636
637 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
638
639 static ByteSize polling_word_offset() {
640 ByteSize offset = byte_offset_of(Thread, _poll_data) +
641 byte_offset_of(SafepointMechanism::ThreadData, _polling_word);
642 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
643 assert(in_bytes(offset) < 128, "Offset >= 128");
644 return offset;
645 }
646
647 static ByteSize polling_page_offset() {
648 ByteSize offset = byte_offset_of(Thread, _poll_data) +
649 byte_offset_of(SafepointMechanism::ThreadData, _polling_page);
650 // At least on x86_64, safepoint polls encode the offset as disp8 imm.
651 assert(in_bytes(offset) < 128, "Offset >= 128");
652 return offset;
653 }
654
655 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
656
657 // Continuation support
658 ContinuationEntry* last_continuation() const { return _cont_entry; }
659 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; }
660 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; }
661 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; }
662 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; }
663 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; }
664 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; }
665
666 void inc_held_monitor_count(intx i = 1, bool jni = false);
667 void dec_held_monitor_count(intx i = 1, bool jni = false);
668
669 intx held_monitor_count() { return _held_monitor_count; }
670 intx jni_monitor_count() { return _jni_monitor_count; }
671 void clear_jni_monitor_count() { _jni_monitor_count = 0; }
672
673 // Support for SharedRuntime::monitor_exit_helper()
674 ObjectMonitor* unlocked_inflated_monitor() const { return _unlocked_inflated_monitor; }
675 void clear_unlocked_inflated_monitor() {
676 _unlocked_inflated_monitor = nullptr;
677 }
678
679 inline bool is_vthread_mounted() const;
680 inline const ContinuationEntry* vthread_continuation() const;
681
682 private:
683 DEBUG_ONLY(void verify_frame_info();)
684
685 // Support for thread handshake operations
686 HandshakeState _handshake;
687 public:
688 HandshakeState* handshake_state() { return &_handshake; }
689
690 // A JavaThread can always safely operate on it self and other threads
691 // can do it safely if they are the active handshaker.
692 bool is_handshake_safe_for(Thread* th) const {
693 return _handshake.active_handshaker() == th || this == th;
694 }
695
696 // Suspend/resume support for JavaThread
697 // higher-level suspension/resume logic called by the public APIs
698 bool java_suspend();
699 bool java_resume();
700 bool is_suspended() { return _handshake.is_suspended(); }
701
702 // Check for async exception in addition to safepoint.
703 static void check_special_condition_for_native_trans(JavaThread *thread);
704
705 // Synchronize with another thread that is deoptimizing objects of the
706 // current thread, i.e. reverts optimizations based on escape analysis.
707 void wait_for_object_deoptimization();
708
709 #if INCLUDE_JVMTI
710 inline void set_carrier_thread_suspended();
711 inline void clear_carrier_thread_suspended();
712
713 bool is_carrier_thread_suspended() const {
714 return _carrier_thread_suspended;
715 }
716
717 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; }
718 bool is_in_tmp_VTMS_transition() const { return _is_in_tmp_VTMS_transition; }
719 bool is_in_any_VTMS_transition() const { return _is_in_VTMS_transition || _is_in_tmp_VTMS_transition; }
720
721 void set_is_in_VTMS_transition(bool val);
722 void toggle_is_in_tmp_VTMS_transition() { _is_in_tmp_VTMS_transition = !_is_in_tmp_VTMS_transition; };
723
724 bool is_disable_suspend() const { return _is_disable_suspend; }
725 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; };
726
727 bool VTMS_transition_mark() const { return Atomic::load(&_VTMS_transition_mark); }
728 void set_VTMS_transition_mark(bool val) { Atomic::store(&_VTMS_transition_mark, val); }
729
730 bool pending_jvmti_unmount_event() { return _pending_jvmti_unmount_event; }
731 void set_pending_jvmti_unmount_event(bool val) { _pending_jvmti_unmount_event = val; }
732
733 bool on_monitor_waited_event() { return _on_monitor_waited_event; }
734 void set_on_monitor_waited_event(bool val) { _on_monitor_waited_event = val; }
735
736 bool pending_contended_entered_event() { return _contended_entered_monitor != nullptr; }
737 ObjectMonitor* contended_entered_monitor() { return _contended_entered_monitor; }
738 #ifdef ASSERT
739 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; }
740 void set_is_VTMS_transition_disabler(bool val);
741 #endif
742 #endif
743
744 void set_contended_entered_monitor(ObjectMonitor* val) NOT_JVMTI_RETURN JVMTI_ONLY({ _contended_entered_monitor = val; })
745
746 // Support for object deoptimization and JFR suspension
747 void handle_special_runtime_exit_condition();
748 bool has_special_runtime_exit_condition() {
749 return (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
750 }
751
752 // Stack-locking support (not for LM_LIGHTWEIGHT)
753 bool is_lock_owned(address adr) const;
754
755 // Accessors for vframe array top
756 // The linked list of vframe arrays are sorted on sp. This means when we
757 // unpack the head must contain the vframe array to unpack.
758 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
759 vframeArray* vframe_array_head() const { return _vframe_array_head; }
760
761 // Side structure for deferring update of java frame locals until deopt occurs
762 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
763 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
764
765 // These only really exist to make debugging deopt problems simpler
766
767 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
768 vframeArray* vframe_array_last() const { return _vframe_array_last; }
769
770 // The special resourceMark used during deoptimization
771
772 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
773 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
774
775 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; }
776 nmethod* deopt_compiled_method() { return _deopt_nmethod; }
777
778 Method* callee_target() const { return _callee_target; }
779 void set_callee_target (Method* x) { _callee_target = x; }
780
781 // Oop results of vm runtime calls
782 oop vm_result() const { return _vm_result; }
783 void set_vm_result (oop x) { _vm_result = x; }
784
785 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
786
787 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
788 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
789
790 // Is thread in scope of an InternalOOMEMark?
791 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; }
792 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; }
793
794 #if INCLUDE_JVMCI
795 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
796 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
797 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
798 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
799 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
800 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; }
801 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; }
802
803 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; }
804 void set_libjvmci_runtime(JVMCIRuntime* rt) {
805 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be");
806 _libjvmci_runtime = rt;
807 }
808 #endif // INCLUDE_JVMCI
809
810 // Exception handling for compiled methods
811 oop exception_oop() const;
812 address exception_pc() const { return _exception_pc; }
813
814 void set_exception_oop(oop o);
815 void set_exception_pc(address a) { _exception_pc = a; }
816 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
817 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
818
819 void clear_exception_oop_and_pc() {
820 set_exception_oop(nullptr);
821 set_exception_pc(nullptr);
822 }
823
824 // Check if address is in the usable part of the stack (excludes protected
825 // guard pages). Can be applied to any thread and is an approximation for
826 // using is_in_live_stack when the query has to happen from another thread.
827 bool is_in_usable_stack(address adr) const {
828 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
829 }
830
831 // Misc. accessors/mutators
832 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); }
833
834 // For assembly stub generation
835 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
836 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); }
837 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
838 static ByteSize pending_jni_exception_check_fn_offset() {
839 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
840 }
841 static ByteSize last_Java_sp_offset() {
842 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
843 }
844 static ByteSize last_Java_pc_offset() {
845 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
846 }
847 static ByteSize frame_anchor_offset() {
848 return byte_offset_of(JavaThread, _anchor);
849 }
850 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
851 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
852 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
853 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
854 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
855 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
856 #if INCLUDE_JVMCI
857 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
858 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
859 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
860 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
861 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
862 #endif // INCLUDE_JVMCI
863 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
864 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
865 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
866 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
867
868 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); }
869
870 // StackOverflow offsets
871 static ByteSize stack_overflow_limit_offset() {
872 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
873 }
874 static ByteSize stack_guard_state_offset() {
875 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
876 }
877 static ByteSize reserved_stack_activation_offset() {
878 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
879 }
880 static ByteSize shadow_zone_safe_limit() {
881 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit);
882 }
883 static ByteSize shadow_zone_growth_watermark() {
884 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark);
885 }
886
887 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
888
889 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
890 static ByteSize should_post_on_exceptions_flag_offset() {
891 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
892 }
893 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
894 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
895
896 static ByteSize lock_id_offset() { return byte_offset_of(JavaThread, _lock_id); }
897
898 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); }
899 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); }
900 static ByteSize held_monitor_count_offset() { return byte_offset_of(JavaThread, _held_monitor_count); }
901 static ByteSize jni_monitor_count_offset() { return byte_offset_of(JavaThread, _jni_monitor_count); }
902 static ByteSize preemption_cancelled_offset() { return byte_offset_of(JavaThread, _preemption_cancelled); }
903 static ByteSize preempt_alternate_return_offset() { return byte_offset_of(JavaThread, _preempt_alternate_return); }
904 static ByteSize unlocked_inflated_monitor_offset() { return byte_offset_of(JavaThread, _unlocked_inflated_monitor); }
905
906 #if INCLUDE_JVMTI
907 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); }
908 static ByteSize is_in_tmp_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_tmp_VTMS_transition); }
909 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); }
910 #endif
911
912 // Returns the jni environment for this thread
913 JNIEnv* jni_environment() { return &_jni_environment; }
914
915 // Returns the current thread as indicated by the given JNIEnv.
916 // We don't assert it is Thread::current here as that is done at the
917 // external JNI entry points where the JNIEnv is passed into the VM.
918 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
919 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset())));
920 // We can't normally get here in a thread that has completed its
921 // execution and so "is_terminated", except when the call is from
922 // AsyncGetCallTrace, which can be triggered by a signal at any point in
923 // a thread's lifecycle. A thread is also considered terminated if the VM
924 // has exited, so we have to check this and block in case this is a daemon
925 // thread returning to the VM (the JNI DirectBuffer entry points rely on
926 // this).
927 if (current->is_terminated()) {
928 current->block_if_vm_exited();
929 }
930 return current;
931 }
932
933 // JNI critical regions. These can nest.
934 bool in_critical() { return _jni_active_critical > 0; }
935 bool in_last_critical() { return _jni_active_critical == 1; }
936 inline void enter_critical();
937 void exit_critical() {
938 assert(Thread::current() == this, "this must be current thread");
939 _jni_active_critical--;
940 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
941 }
942
943 // Checked JNI: is the programmer required to check for exceptions, if so specify
944 // which function name. Returning to a Java frame should implicitly clear the
945 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
946 // VM->Java transitions are not cleared, it is expected that JNI code enclosed
947 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
948 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; }
949 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; }
950 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
951 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
952
953 // For deadlock detection
954 int depth_first_number() { return _depth_first_number; }
955 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
956
957 public:
958 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
959 void inc_in_deopt_handler() { _in_deopt_handler++; }
960 void dec_in_deopt_handler() {
961 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
962 if (_in_deopt_handler > 0) { // robustness
963 _in_deopt_handler--;
964 }
965 }
966
967 private:
968 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
969
970 // factor out low-level mechanics for use in both normal and error cases
971 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const;
972
973 public:
974
975 // Frame iteration; calls the function f for all frames on the stack
976 void frames_do(void f(frame*, const RegisterMap*));
977
978 // Memory operations
979 void oops_do_frames(OopClosure* f, NMethodClosure* cf);
980 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
981
982 // GC operations
983 virtual void nmethods_do(NMethodClosure* cf);
984
985 // RedefineClasses Support
986 void metadata_do(MetadataClosure* f);
987
988 // Debug method asserting thread states are correct during a handshake operation.
989 DEBUG_ONLY(void verify_states_for_handshake();)
990
991 // Misc. operations
992 const char* name() const;
993 const char* name_raw() const;
994 const char* type_name() const { return "JavaThread"; }
995 static const char* name_for(oop thread_obj);
996
997 void print_on(outputStream* st, bool print_extended_info) const;
998 void print_on(outputStream* st) const { print_on(st, false); }
999 void print() const;
1000 void print_thread_state_on(outputStream*) const;
1001 void print_on_error(outputStream* st, char* buf, int buflen) const;
1002 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1003 void verify();
1004
1005 // Accessing frames
1006 frame last_frame() {
1007 _anchor.make_walkable();
1008 return pd_last_frame();
1009 }
1010 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); }
1011
1012 frame carrier_last_frame(RegisterMap* reg_map);
1013 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); }
1014
1015 frame vthread_last_frame();
1016 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); }
1017
1018 frame platform_thread_last_frame(RegisterMap* reg_map);
1019 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) {
1020 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map);
1021 }
1022
1023 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map);
1024
1025 // Returns method at 'depth' java or native frames down the stack
1026 // Used for security checks
1027 Klass* security_get_caller_class(int depth);
1028
1029 // Print stack trace in external format
1030 // These variants print carrier/platform thread information only.
1031 void print_stack_on(outputStream* st);
1032 void print_stack() { print_stack_on(tty); }
1033 // This prints the currently mounted virtual thread.
1034 void print_vthread_stack_on(outputStream* st);
1035 // This prints the active stack: either carrier/platform or virtual.
1036 void print_active_stack_on(outputStream* st);
1037 // Print current stack trace for checked JNI warnings and JNI fatal errors.
1038 // This is the external format from above, but selecting the platform
1039 // or vthread as applicable.
1040 void print_jni_stack();
1041
1042 // Print stack traces in various internal formats
1043 void trace_stack() PRODUCT_RETURN;
1044 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1045 void trace_frames() PRODUCT_RETURN;
1046
1047 // Print an annotated view of the stack frames
1048 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1049 void validate_frame_layout() {
1050 print_frame_layout(0, true);
1051 }
1052
1053 // Function for testing deoptimization
1054 void deoptimize();
1055 void make_zombies();
1056
1057 void deoptimize_marked_methods();
1058
1059 public:
1060 // Returns the running thread as a JavaThread
1061 static JavaThread* current() {
1062 return JavaThread::cast(Thread::current());
1063 }
1064
1065 // Returns the current thread as a JavaThread, or nullptr if not attached
1066 static inline JavaThread* current_or_null();
1067
1068 // Casts
1069 static JavaThread* cast(Thread* t) {
1070 assert(t->is_Java_thread(), "incorrect cast to JavaThread");
1071 return static_cast<JavaThread*>(t);
1072 }
1073
1074 static const JavaThread* cast(const Thread* t) {
1075 assert(t->is_Java_thread(), "incorrect cast to const JavaThread");
1076 return static_cast<const JavaThread*>(t);
1077 }
1078
1079 // Returns the active Java thread. Do not use this if you know you are calling
1080 // from a JavaThread, as it's slower than JavaThread::current. If called from
1081 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1082 // operation. You may not want that either.
1083 static JavaThread* active();
1084
1085 protected:
1086 virtual void pre_run();
1087 virtual void run();
1088 void thread_main_inner();
1089 virtual void post_run();
1090
1091 public:
1092 // Thread local information maintained by JVMTI.
1093 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1094 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1095 // getter is used to get this JavaThread's JvmtiThreadState if it has
1096 // one which means null can be returned. JvmtiThreadState::state_for()
1097 // is used to get the specified JavaThread's JvmtiThreadState if it has
1098 // one or it allocates a new JvmtiThreadState for the JavaThread and
1099 // returns it. JvmtiThreadState::state_for() will return null only if
1100 // the specified JavaThread is exiting.
1101 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1102 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1103
1104 #if INCLUDE_JVMTI
1105 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier.
1106 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop);
1107 #endif
1108
1109 // JVMTI PopFrame support
1110 // Setting and clearing popframe_condition
1111 // All of these enumerated values are bits. popframe_pending
1112 // indicates that a PopFrame() has been requested and not yet been
1113 // completed. popframe_processing indicates that that PopFrame() is in
1114 // the process of being completed. popframe_force_deopt_reexecution_bit
1115 // indicates that special handling is required when returning to a
1116 // deoptimized caller.
1117 enum PopCondition {
1118 popframe_inactive = 0x00,
1119 popframe_pending_bit = 0x01,
1120 popframe_processing_bit = 0x02,
1121 popframe_force_deopt_reexecution_bit = 0x04
1122 };
1123 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1124 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1125 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1126 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1127 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1128 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1129 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1130
1131 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1132 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1133 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1134
1135 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1136 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1137 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1138
1139 private:
1140 // Saved incoming arguments to popped frame.
1141 // Used only when popped interpreted frame returns to deoptimized frame.
1142 void* _popframe_preserved_args;
1143 int _popframe_preserved_args_size;
1144
1145 public:
1146 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1147 void* popframe_preserved_args();
1148 ByteSize popframe_preserved_args_size();
1149 WordSize popframe_preserved_args_size_in_words();
1150 void popframe_free_preserved_args();
1151
1152
1153 private:
1154 JvmtiThreadState *_jvmti_thread_state;
1155
1156 // Used by the interpreter in fullspeed mode for frame pop, method
1157 // entry, method exit and single stepping support. This field is
1158 // only set to non-zero at a safepoint or using a direct handshake
1159 // (see EnterInterpOnlyModeClosure).
1160 // It can be set to zero asynchronously to this threads execution (i.e., without
1161 // safepoint/handshake or a lock) so we have to be very careful.
1162 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1163 int _interp_only_mode;
1164
1165 public:
1166 // used by the interpreter for fullspeed debugging support (see above)
1167 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1168 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1169 int get_interp_only_mode() { return _interp_only_mode; }
1170 int set_interp_only_mode(int val) { return _interp_only_mode = val; }
1171 void increment_interp_only_mode() { ++_interp_only_mode; }
1172 void decrement_interp_only_mode() { --_interp_only_mode; }
1173
1174 // support for cached flag that indicates whether exceptions need to be posted for this thread
1175 // if this is false, we can avoid deoptimizing when events are thrown
1176 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1177 private:
1178 int _should_post_on_exceptions_flag;
1179
1180 public:
1181 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1182
1183 private:
1184 ThreadStatistics *_thread_stat;
1185
1186 public:
1187 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1188
1189 // Return a blocker object for which this thread is blocked parking.
1190 oop current_park_blocker();
1191
1192 private:
1193 static size_t _stack_size_at_create;
1194
1195 public:
1196 static inline size_t stack_size_at_create(void) {
1197 return _stack_size_at_create;
1198 }
1199 static inline void set_stack_size_at_create(size_t value) {
1200 _stack_size_at_create = value;
1201 }
1202
1203 // Machine dependent stuff
1204 #include OS_CPU_HEADER(javaThread)
1205
1206 // JSR166 per-thread parker
1207 private:
1208 Parker _parker;
1209 public:
1210 Parker* parker() { return &_parker; }
1211
1212 public:
1213 // clearing/querying jni attach status
1214 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1215 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1216 inline void set_done_attaching_via_jni();
1217
1218 // Stack dump assistance:
1219 // Track the class we want to initialize but for which we have to wait
1220 // on its init_lock() because it is already being initialized.
1221 void set_class_to_be_initialized(InstanceKlass* k);
1222 InstanceKlass* class_to_be_initialized() const;
1223
1224 private:
1225 InstanceKlass* _class_to_be_initialized;
1226
1227 // java.lang.Thread.sleep support
1228 ParkEvent * _SleepEvent;
1229 public:
1230 bool sleep(jlong millis);
1231 bool sleep_nanos(jlong nanos);
1232
1233 // java.lang.Thread interruption support
1234 void interrupt();
1235 bool is_interrupted(bool clear_interrupted);
1236
1237 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
1238 // the Java code in Object::wait which are not present in RawMonitorWait.
1239 bool get_and_clear_interrupted();
1240
1241 private:
1242 LockStack _lock_stack;
1243 OMCache _om_cache;
1244
1245 public:
1246 LockStack& lock_stack() { return _lock_stack; }
1247
1248 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); }
1249 // Those offsets are used in code generators to access the LockStack that is embedded in this
1250 // JavaThread structure. Those accesses are relative to the current thread, which
1251 // is typically in a dedicated register.
1252 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); }
1253 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1254
1255 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); }
1256 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); }
1257
1258 void om_set_monitor_cache(ObjectMonitor* monitor);
1259 void om_clear_monitor_cache();
1260 ObjectMonitor* om_get_from_monitor_cache(oop obj);
1261
1262 static OopStorage* thread_oop_storage();
1263
1264 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1265
1266 // Helper function to create the java.lang.Thread object for a
1267 // VM-internal thread. The thread will have the given name and be
1268 // part of the System ThreadGroup.
1269 static Handle create_system_thread_object(const char* name, TRAPS);
1270
1271 // Helper function to start a VM-internal daemon thread.
1272 // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1273 static void start_internal_daemon(JavaThread* current, JavaThread* target,
1274 Handle thread_oop, ThreadPriority prio);
1275
1276 // Helper function to do vm_exit_on_initialization for osthread
1277 // resource allocation failure.
1278 static void vm_exit_on_osthread_failure(JavaThread* thread);
1279
1280 // Deferred OopHandle release support
1281 private:
1282 // List of OopHandles to be released - guarded by the Service_lock.
1283 static OopHandleList* _oop_handle_list;
1284 // Add our OopHandles to the list for the service thread to release.
1285 void add_oop_handles_for_release();
1286 // Called by the ServiceThread to release the OopHandles.
1287 static void release_oop_handles();
1288 // Called by the ServiceThread to poll if there are any OopHandles to release.
1289 // Called when holding the Service_lock.
1290 static bool has_oop_handles_to_release() {
1291 return _oop_handle_list != nullptr;
1292 }
1293 };
1294
1295 inline JavaThread* JavaThread::current_or_null() {
1296 Thread* current = Thread::current_or_null();
1297 return current != nullptr ? JavaThread::cast(current) : nullptr;
1298 }
1299
1300 class UnlockFlagSaver {
1301 private:
1302 JavaThread* _thread;
1303 bool _do_not_unlock;
1304 public:
1305 UnlockFlagSaver(JavaThread* t) {
1306 _thread = t;
1307 _do_not_unlock = t->do_not_unlock_if_synchronized();
1308 t->set_do_not_unlock_if_synchronized(false);
1309 }
1310 ~UnlockFlagSaver() {
1311 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1312 }
1313 };
1314
1315 class JNIHandleMark : public StackObj {
1316 JavaThread* _thread;
1317 public:
1318 JNIHandleMark(JavaThread* thread) : _thread(thread) {
1319 thread->push_jni_handle_block();
1320 }
1321 ~JNIHandleMark() { _thread->pop_jni_handle_block(); }
1322 };
1323
1324 class NoPreemptMark {
1325 ContinuationEntry* _ce;
1326 bool _unpin;
1327 public:
1328 NoPreemptMark(JavaThread* thread) : _ce(thread->last_continuation()), _unpin(false) {
1329 if (_ce != nullptr) _unpin = _ce->pin();
1330 }
1331 ~NoPreemptMark() { if (_unpin) _ce->unpin(); }
1332 };
1333
1334 class ThreadOnMonitorWaitedEvent {
1335 JavaThread* _thread;
1336 public:
1337 ThreadOnMonitorWaitedEvent(JavaThread* thread) : _thread(thread) {
1338 JVMTI_ONLY(_thread->set_on_monitor_waited_event(true);)
1339 }
1340 ~ThreadOnMonitorWaitedEvent() { JVMTI_ONLY(_thread->set_on_monitor_waited_event(false);) }
1341 };
1342
1343 #endif // SHARE_RUNTIME_JAVATHREAD_HPP