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