1 /*
2 * Copyright (c) 1997, 2025, 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_THREAD_HPP
27 #define SHARE_RUNTIME_THREAD_HPP
28
29 #include "gc/shared/gcThreadLocalData.hpp"
30 #include "gc/shared/threadLocalAllocBuffer.hpp"
31 #include "jni.h"
32 #include "memory/allocation.hpp"
33 #include "runtime/atomic.hpp"
34 #include "runtime/globals.hpp"
35 #include "runtime/os.hpp"
36 #include "runtime/safepointMechanism.hpp"
37 #include "runtime/threadHeapSampler.hpp"
38 #include "runtime/threadLocalStorage.hpp"
39 #include "runtime/threadStatisticalInfo.hpp"
40 #include "runtime/unhandledOops.hpp"
41 #include "utilities/globalDefinitions.hpp"
42 #include "utilities/macros.hpp"
43 #if INCLUDE_JFR
44 #include "jfr/support/jfrThreadExtension.hpp"
45 #endif
46
47 class CompilerThread;
48 class HandleArea;
49 class HandleMark;
50 class JvmtiRawMonitor;
51 class NMethodClosure;
52 class Metadata;
53 class OopClosure;
54 class OSThread;
55 class ParkEvent;
56 class ResourceArea;
57 class SafeThreadsListPtr;
58 class ThreadClosure;
59 class ThreadsList;
60 class ThreadsSMRSupport;
61 class VMErrorCallback;
62
63
64 class PerfTraceTime;
65
66 DEBUG_ONLY(class ResourceMark;)
67
68 class WorkerThread;
69
70 class JavaThread;
71
72 // Class hierarchy
73 // - Thread
74 // - JavaThread
75 // - various subclasses eg CompilerThread, ServiceThread
76 // - NonJavaThread
77 // - NamedThread
78 // - VMThread
79 // - ConcurrentGCThread
80 // - WorkerThread
81 // - WatcherThread
82 // - JfrThreadSampler
83 // - LogAsyncWriter
84 //
85 // All Thread subclasses must be either JavaThread or NonJavaThread.
86 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
87 // a partially constructed/destroyed Thread.
88
89 // Thread execution sequence and actions:
90 // All threads:
91 // - thread_native_entry // per-OS native entry point
92 // - stack initialization
93 // - other OS-level initialization (signal masks etc)
94 // - handshake with creating thread (if not started suspended)
95 // - this->call_run() // common shared entry point
96 // - shared common initialization
97 // - this->pre_run() // virtual per-thread-type initialization
98 // - this->run() // virtual per-thread-type "main" logic
99 // - shared common tear-down
100 // - this->post_run() // virtual per-thread-type tear-down
101 // - // 'this' no longer referenceable
102 // - OS-level tear-down (minimal)
103 // - final logging
104 //
105 // For JavaThread:
106 // - this->run() // virtual but not normally overridden
107 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
108 // - this->entry_point() // set differently for each kind of JavaThread
109
110 class Thread: public ThreadShadow {
111 friend class VMError;
112 friend class VMErrorCallbackMark;
113 friend class VMStructs;
114 friend class JVMCIVMStructs;
115 friend class JavaThread;
116 private:
117
118 // Current thread is maintained as a thread-local variable
119 static THREAD_LOCAL Thread* _thr_current;
120
121 // On AArch64, the high order 32 bits are used by a "patching epoch" number
122 // which reflects if this thread has executed the required fences, after
123 // an nmethod gets disarmed. The low order 32 bits denote the disarmed value.
124 uint64_t _nmethod_disarmed_guard_value;
125
126 public:
127 void set_nmethod_disarmed_guard_value(int value) {
128 _nmethod_disarmed_guard_value = (uint64_t)(uint32_t)value;
129 }
130
131 static ByteSize nmethod_disarmed_guard_value_offset() {
132 ByteSize offset = byte_offset_of(Thread, _nmethod_disarmed_guard_value);
133 // At least on x86_64, nmethod entry barrier encodes disarmed value offset
134 // in instruction as disp8 immed
135 assert(in_bytes(offset) < 128, "Offset >= 128");
136 return offset;
137 }
138
139 private:
140 // Poll data is used in generated code for safepoint polls.
141 // It is important for performance to put this at lower offset
142 // in Thread. The accessors are in JavaThread.
143 SafepointMechanism::ThreadData _poll_data;
144
145 // Thread local data area available to the GC. The internal
146 // structure and contents of this data area is GC-specific.
147 // Only GC and GC barrier code should access this data area.
148 GCThreadLocalData _gc_data;
149
150 public:
151 static ByteSize gc_data_offset() {
152 return byte_offset_of(Thread, _gc_data);
153 }
154
155 template <typename T> T* gc_data() {
156 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
157 return reinterpret_cast<T*>(&_gc_data);
158 }
159
160 // Exception handling
161 // (Note: _pending_exception and friends are in ThreadShadow)
162 //oop _pending_exception; // pending exception for current thread
163 // const char* _exception_file; // file information for exception (debugging only)
164 // int _exception_line; // line information for exception (debugging only)
165 protected:
166 // JavaThread lifecycle support:
167 friend class SafeThreadsListPtr; // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
168 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
169 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
170 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
171 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
172 friend class ThreadsListHandleTest; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
173 friend class ValidateHazardPtrsClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
174
175 ThreadsList* volatile _threads_hazard_ptr;
176 SafeThreadsListPtr* _threads_list_ptr;
177 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
178 ThreadsList* get_threads_hazard_ptr() const;
179 void set_threads_hazard_ptr(ThreadsList* new_list);
180 static bool is_hazard_ptr_tagged(ThreadsList* list) {
181 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
182 }
183 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
184 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
185 }
186 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
187 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
188 }
189 // This field is enabled via -XX:+EnableThreadSMRStatistics:
190 uint _nested_threads_hazard_ptr_cnt;
191 void dec_nested_threads_hazard_ptr_cnt() {
192 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
193 _nested_threads_hazard_ptr_cnt--;
194 }
195 void inc_nested_threads_hazard_ptr_cnt() {
196 _nested_threads_hazard_ptr_cnt++;
197 }
198 uint nested_threads_hazard_ptr_cnt() {
199 return _nested_threads_hazard_ptr_cnt;
200 }
201
202 public:
203 // Is the target JavaThread protected by the calling Thread or by some other
204 // mechanism?
205 static bool is_JavaThread_protected(const JavaThread* target);
206 // Is the target JavaThread protected by a ThreadsListHandle (TLH) associated
207 // with the calling Thread?
208 static bool is_JavaThread_protected_by_TLH(const JavaThread* target);
209
210 private:
211 DEBUG_ONLY(static Thread* _starting_thread;)
212 DEBUG_ONLY(bool _suspendible_thread;)
213 DEBUG_ONLY(bool _indirectly_suspendible_thread;)
214 DEBUG_ONLY(bool _indirectly_safepoint_thread;)
215
216 public:
217 #ifdef ASSERT
218 static bool is_starting_thread(const Thread* t);
219
220 void set_suspendible_thread() { _suspendible_thread = true; }
221 void clear_suspendible_thread() { _suspendible_thread = false; }
222 bool is_suspendible_thread() { return _suspendible_thread; }
223
224 void set_indirectly_suspendible_thread() { _indirectly_suspendible_thread = true; }
225 void clear_indirectly_suspendible_thread() { _indirectly_suspendible_thread = false; }
226 bool is_indirectly_suspendible_thread() { return _indirectly_suspendible_thread; }
227
228 void set_indirectly_safepoint_thread() { _indirectly_safepoint_thread = true; }
229 void clear_indirectly_safepoint_thread() { _indirectly_safepoint_thread = false; }
230 bool is_indirectly_safepoint_thread() { return _indirectly_safepoint_thread; }
231 #endif
232
233 private:
234 // Point to the last handle mark
235 HandleMark* _last_handle_mark;
236
237 // Claim value for parallel iteration over threads.
238 uintx _threads_do_token;
239
240 // Support for GlobalCounter
241 private:
242 volatile uintx _rcu_counter;
243 public:
244 volatile uintx* get_rcu_counter() {
245 return &_rcu_counter;
246 }
247
248 public:
249 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
250 HandleMark* last_handle_mark() const { return _last_handle_mark; }
251
252 private:
253 // Used by SkipGCALot class.
254 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
255
256 friend class GCLocker;
257
258 private:
259 ThreadLocalAllocBuffer _tlab; // Thread-local eden
260 jlong _allocated_bytes; // Cumulative number of bytes allocated on
261 // the Java heap
262 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
263
264 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
265
266 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
267
268 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
269 // is waiting to lock
270 public:
271 // Constructor
272 Thread(MemTag mem_tag = mtThread);
273 virtual ~Thread() = 0; // Thread is abstract.
274
275 // Manage Thread::current()
276 void initialize_thread_current();
277 static void clear_thread_current(); // TLS cleanup needed before threads terminate
278
279 protected:
280 // To be implemented by children.
281 virtual void run() = 0;
282 virtual void pre_run() = 0;
283 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
284
285 #ifdef ASSERT
286 enum RunState {
287 PRE_CALL_RUN,
288 CALL_RUN,
289 PRE_RUN,
290 RUN,
291 POST_RUN
292 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
293 };
294 RunState _run_state; // for lifecycle checks
295 #endif
296
297
298 public:
299 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
300 void call_run();
301
302 // Testers
303 virtual bool is_VM_thread() const { return false; }
304 virtual bool is_Java_thread() const { return false; }
305 virtual bool is_Compiler_thread() const { return false; }
306 virtual bool is_service_thread() const { return false; }
307 virtual bool is_hidden_from_external_view() const { return false; }
308 virtual bool is_jvmti_agent_thread() const { return false; }
309 virtual bool is_Watcher_thread() const { return false; }
310 virtual bool is_ConcurrentGC_thread() const { return false; }
311 virtual bool is_Named_thread() const { return false; }
312 virtual bool is_Worker_thread() const { return false; }
313 virtual bool is_JfrSampler_thread() const { return false; }
314 virtual bool is_JfrRecorder_thread() const { return false; }
315 virtual bool is_AttachListener_thread() const { return false; }
316 virtual bool is_monitor_deflation_thread() const { return false; }
317
318 // Convenience cast functions
319 CompilerThread* as_Compiler_thread() const {
320 assert(is_Compiler_thread(), "Must be compiler thread");
321 return (CompilerThread*)this;
322 }
323
324 // Can this thread make Java upcalls
325 virtual bool can_call_java() const { return false; }
326
327 // Is this a JavaThread that is on the VM's current ThreadsList?
328 // If so it must participate in the safepoint protocol.
329 virtual bool is_active_Java_thread() const { return false; }
330
331 // All threads are given names. For singleton subclasses we can
332 // just hard-wire the known name of the instance. JavaThreads and
333 // NamedThreads support multiple named instances, and dynamic
334 // changing of the name of an instance.
335 virtual const char* name() const { return "Unknown thread"; }
336
337 // A thread's type name is also made available for debugging
338 // and logging.
339 virtual const char* type_name() const { return "Thread"; }
340
341 // Returns the current thread (ASSERTS if null)
342 static inline Thread* current();
343 // Returns the current thread, or null if not attached
344 static inline Thread* current_or_null();
345 // Returns the current thread, or null if not attached, and is
346 // safe for use from signal-handlers
347 static inline Thread* current_or_null_safe();
348
349 // Common thread operations
350 #ifdef ASSERT
351 static void check_for_dangling_thread_pointer(Thread *thread);
352 #endif
353 static void set_priority(Thread* thread, ThreadPriority priority);
354 static void start(Thread* thread);
355
356 void set_native_thread_name(const char *name) {
357 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
358 os::set_native_thread_name(name);
359 }
360
361 // Support for Unhandled Oop detection
362 // Add the field for both, fastdebug and debug, builds to keep
363 // Thread's fields layout the same.
364 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
365 #ifdef CHECK_UNHANDLED_OOPS
366 private:
367 UnhandledOops* _unhandled_oops;
368 #elif defined(ASSERT)
369 private:
370 void* _unhandled_oops;
371 #endif
372 #ifdef CHECK_UNHANDLED_OOPS
373 public:
374 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
375 // Mark oop safe for gc. It may be stack allocated but won't move.
376 void allow_unhandled_oop(oop *op) {
377 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
378 }
379 // Clear oops at safepoint so crashes point to unhandled oop violator
380 void clear_unhandled_oops() {
381 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
382 }
383 #endif // CHECK_UNHANDLED_OOPS
384
385 public:
386 #ifndef PRODUCT
387 bool skip_gcalot() { return _skip_gcalot; }
388 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
389 #endif
390
391 // Resource area
392 ResourceArea* resource_area() const { return _resource_area; }
393 void set_resource_area(ResourceArea* area) { _resource_area = area; }
394
395 OSThread* osthread() const { return _osthread; }
396 void set_osthread(OSThread* thread) { _osthread = thread; }
397
398 // Internal handle support
399 HandleArea* handle_area() const { return _handle_area; }
400 void set_handle_area(HandleArea* area) { _handle_area = area; }
401
402 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
403 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
404
405 // Thread-Local Allocation Buffer (TLAB) support
406 ThreadLocalAllocBuffer& tlab() { return _tlab; }
407 void initialize_tlab();
408 void retire_tlab(ThreadLocalAllocStats* stats = nullptr);
409 void fill_tlab(HeapWord* start, size_t pre_reserved, size_t new_size);
410
411 jlong allocated_bytes() { return _allocated_bytes; }
412 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
413 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
414 inline jlong cooked_allocated_bytes();
415
416 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
417
418 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
419
420 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
421
422 // For tracking the Jvmti raw monitor the thread is pending on.
423 JvmtiRawMonitor* current_pending_raw_monitor() {
424 return _current_pending_raw_monitor;
425 }
426 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
427 _current_pending_raw_monitor = monitor;
428 }
429
430 // GC support
431 // Apply "f->do_oop" to all root oops in "this".
432 // Used by JavaThread::oops_do.
433 // Apply "cf->do_nmethod" (if !nullptr) to all nmethods active in frames
434 virtual void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
435 virtual void oops_do_frames(OopClosure* f, NMethodClosure* cf) {}
436 void oops_do(OopClosure* f, NMethodClosure* cf);
437
438 // Handles the parallel case for claim_threads_do.
439 private:
440 bool claim_par_threads_do(uintx claim_token);
441 public:
442 // Requires that "claim_token" is that of the current iteration.
443 // If "is_par" is false, sets the token of "this" to
444 // "claim_token", and returns "true". If "is_par" is true,
445 // uses an atomic instruction to set the current thread's token to
446 // "claim_token", if it is not already. Returns "true" iff the
447 // calling thread does the update, this indicates that the calling thread
448 // has claimed the thread in the current iteration.
449 bool claim_threads_do(bool is_par, uintx claim_token) {
450 if (!is_par) {
451 _threads_do_token = claim_token;
452 return true;
453 } else {
454 return claim_par_threads_do(claim_token);
455 }
456 }
457
458 uintx threads_do_token() const { return _threads_do_token; }
459
460 // jvmtiRedefineClasses support
461 void metadata_handles_do(void f(Metadata*));
462
463 private:
464 // Check if address is within the given range of this thread's
465 // stack: stack_base() > adr >/>= limit
466 // The check is inclusive of limit if passed true, else exclusive.
467 bool is_in_stack_range(address adr, address limit, bool inclusive) const {
468 assert(stack_base() > limit && limit >= stack_end(), "limit is outside of stack");
469 return stack_base() > adr && (inclusive ? adr >= limit : adr > limit);
470 }
471
472 public:
473 // Check if address is within the given range of this thread's
474 // stack: stack_base() > adr >= limit
475 bool is_in_stack_range_incl(address adr, address limit) const {
476 return is_in_stack_range(adr, limit, true);
477 }
478
479 // Check if address is within the given range of this thread's
480 // stack: stack_base() > adr > limit
481 bool is_in_stack_range_excl(address adr, address limit) const {
482 return is_in_stack_range(adr, limit, false);
483 }
484
485 // Check if address is in the stack mapped to this thread. Used mainly in
486 // error reporting (so has to include guard zone) and frame printing.
487 // Expects _stack_base to be initialized - checked with assert.
488 bool is_in_full_stack_checked(address adr) const {
489 return is_in_stack_range_incl(adr, stack_end());
490 }
491
492 // Like is_in_full_stack_checked but without the assertions as this
493 // may be called in a thread before _stack_base is initialized.
494 bool is_in_full_stack(address adr) const {
495 address stack_end = _stack_base - _stack_size;
496 return _stack_base > adr && adr >= stack_end;
497 }
498
499 // Check if address is in the live stack of this thread (not just for locks).
500 // Warning: can only be called by the current thread on itself.
501 bool is_in_live_stack(address adr) const {
502 assert(Thread::current() == this, "is_in_live_stack can only be called from current thread");
503 return is_in_stack_range_incl(adr, os::current_stack_pointer());
504 }
505
506 // Sets the argument thread as starting thread. Returns failure if thread
507 // creation fails due to lack of memory, too many threads etc.
508 static bool set_as_starting_thread(JavaThread* jt);
509
510 protected:
511 // OS data associated with the thread
512 OSThread* _osthread; // Platform-specific thread information
513
514 // Thread local resource area for temporary allocation within the VM
515 ResourceArea* _resource_area;
516
517 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
518
519 // Thread local handle area for allocation of handles within the VM
520 HandleArea* _handle_area;
521 GrowableArray<Metadata*>* _metadata_handles;
522
523 // Support for stack overflow handling, get_thread, etc.
524 address _stack_base;
525 size_t _stack_size;
526 int _lgrp_id;
527
528 public:
529 // Stack overflow support
530 address stack_base() const DEBUG_ONLY(;) NOT_DEBUG({ return _stack_base; })
531 // Needed for code that can query a new thread before the stack has been set.
532 address stack_base_or_null() const { return _stack_base; }
533 void set_stack_base(address base) { _stack_base = base; }
534 size_t stack_size() const { return _stack_size; }
535 void set_stack_size(size_t size) { _stack_size = size; }
536 address stack_end() const { return stack_base() - stack_size(); }
537 void record_stack_base_and_size();
538 void register_thread_stack_with_NMT();
539 void unregister_thread_stack_with_NMT();
540
541 int lgrp_id() const { return _lgrp_id; }
542 void set_lgrp_id(int value) { _lgrp_id = value; }
543
544 // Printing
545 void print_on(outputStream* st, bool print_extended_info) const;
546 virtual void print_on(outputStream* st) const { print_on(st, false); }
547 void print() const;
548 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
549 // Basic, non-virtual, printing support that is simple and always safe.
550 void print_value_on(outputStream* st) const;
551
552 // Debug-only code
553 #ifdef ASSERT
554 private:
555 // Deadlock detection support for Mutex locks. List of locks own by thread.
556 Mutex* _owned_locks;
557 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
558 // thus the friendship
559 friend class Mutex;
560 friend class Monitor;
561
562 public:
563 void print_owned_locks_on(outputStream* st) const;
564 void print_owned_locks() const { print_owned_locks_on(tty); }
565 Mutex* owned_locks() const { return _owned_locks; }
566 bool owns_locks() const { return owned_locks() != nullptr; }
567
568 // Deadlock detection
569 ResourceMark* current_resource_mark() { return _current_resource_mark; }
570 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
571 #endif // ASSERT
572
573 private:
574 volatile int _jvmti_env_iteration_count;
575
576 public:
577 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
578 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
579 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
580
581 // Code generation
582 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
583 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
584
585 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
586 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
587
588 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
589 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
590 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
591 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
592
593 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
594
595 public:
596 ParkEvent * volatile _ParkEvent; // for Object monitors, JVMTI raw monitors,
597 // and ObjectSynchronizer::read_stable_mark
598
599 // Termination indicator used by the signal handler.
600 // _ParkEvent is just a convenient field we can null out after setting the JavaThread termination state
601 // (which can't itself be read from the signal handler if a signal hits during the Thread destructor).
602 bool has_terminated() { return Atomic::load(&_ParkEvent) == nullptr; };
603
604 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
605 jint _hashStateX; // thread-specific hashCode generator state
606 jint _hashStateY;
607 jint _hashStateZ;
608
609 // Low-level leaf-lock primitives used to implement synchronization.
610 // Not for general synchronization use.
611 static void SpinAcquire(volatile int * Lock);
612 static void SpinRelease(volatile int * Lock);
613
614 #if defined(__APPLE__) && defined(AARCH64)
615 private:
616 DEBUG_ONLY(bool _wx_init);
617 WXMode _wx_state;
618 public:
619 void init_wx();
620 WXMode enable_wx(WXMode new_state);
621
622 void assert_wx_state(WXMode expected) {
623 assert(_wx_state == expected, "wrong state");
624 }
625 #endif // __APPLE__ && AARCH64
626
627 private:
628 bool _in_asgct = false;
629 public:
630 bool in_asgct() const { return _in_asgct; }
631 void set_in_asgct(bool value) { _in_asgct = value; }
632 static bool current_in_asgct() {
633 Thread *cur = Thread::current_or_null_safe();
634 return cur != nullptr && cur->in_asgct();
635 }
636
637 private:
638 VMErrorCallback* _vm_error_callbacks;
639
640 bool _profile_vm_locks;
641 bool _profile_vm_calls;
642 bool _profile_vm_ops;
643 bool _profile_rt_calls;
644 bool _profile_upcalls;
645
646 jlong _all_bc_counter_value;
647 jlong _clinit_bc_counter_value;
648
649 PerfTraceTime* _current_rt_call_timer;
650 public:
651 bool profile_vm_locks() const { return _profile_vm_locks; }
652 void set_profile_vm_locks(bool v) { _profile_vm_locks = v; }
653
654 bool profile_vm_calls() const { return _profile_vm_calls; }
655 void set_profile_vm_calls(bool v) { _profile_vm_calls = v; }
656
657 bool profile_vm_ops() const { return _profile_vm_ops; }
658 void set_profile_vm_ops(bool v) { _profile_vm_ops = v; }
659
660 bool profile_rt_calls() const { return _profile_rt_calls; }
661 void set_profile_rt_calls(bool v) { _profile_rt_calls = v; }
662
663 bool profile_upcalls() const { return _profile_upcalls; }
664 void set_profile_upcalls(bool v) { _profile_upcalls = v; }
665
666 PerfTraceTime* current_rt_call_timer() const { return _current_rt_call_timer; }
667 void set_current_rt_call_timer(PerfTraceTime* c) { _current_rt_call_timer = c; }
668 bool has_current_rt_call_timer() const { return _current_rt_call_timer != nullptr; }
669
670 bool do_profile_rt_call() const {
671 return ProfileRuntimeCalls && profile_rt_calls() && !has_current_rt_call_timer();
672 }
673
674 jlong bc_counter_value() const { return _all_bc_counter_value; }
675
676 jlong clinit_bc_counter_value() const { return _clinit_bc_counter_value; }
677
678 void inc_clinit_bc_counter_value(jlong l) { _clinit_bc_counter_value += l; }
679
680 static ByteSize bc_counter_offset() { return byte_offset_of(Thread, _all_bc_counter_value); }
681 };
682
683 class ProfileVMCallContext : StackObj {
684 private:
685 Thread* _thread;
686 bool _enabled;
687 PerfTraceTime* _timer;
688
689 static int _perf_nested_runtime_calls_count;
690
691 static const char* name(PerfTraceTime* t);
692 static void notify_nested_rt_call(PerfTraceTime* current, PerfTraceTime* inner_timer);
693 public:
694 inline ProfileVMCallContext(Thread* current, PerfTraceTime* timer, bool is_on)
695 : _thread(current), _enabled(is_on), _timer(timer) {
696 if (_enabled) {
697 assert(timer != nullptr, "");
698 assert(_thread->current_rt_call_timer() == nullptr, "%s", name(_thread->current_rt_call_timer()));
699 _thread->set_current_rt_call_timer(timer);
700 } else if (current->profile_rt_calls()) {
701 notify_nested_rt_call(current->current_rt_call_timer(), timer);
702 }
703 }
704
705 inline ~ProfileVMCallContext() {
706 if (_enabled) {
707 assert(_timer == _thread->current_rt_call_timer(),
708 "%s vs %s", name(_timer), name(_thread->current_rt_call_timer()));
709 _thread->set_current_rt_call_timer(nullptr);
710 }
711 }
712
713 static int nested_runtime_calls_count() { return _perf_nested_runtime_calls_count; };
714 };
715
716 class PauseRuntimeCallProfiling : public StackObj {
717 protected:
718 Thread* _thread;
719 bool _enabled;
720 PerfTraceTime* _timer;
721
722 public:
723 inline PauseRuntimeCallProfiling(Thread* current, bool is_on)
724 : _thread(current), _enabled(is_on), _timer(nullptr) {
725 if (_enabled) {
726 _timer = _thread->current_rt_call_timer();
727 _thread->set_current_rt_call_timer(nullptr);
728 }
729 }
730
731 inline ~PauseRuntimeCallProfiling () {
732 if (_enabled) {
733 guarantee(_thread->current_rt_call_timer() == nullptr, "");
734 _thread->set_current_rt_call_timer(_timer); // restore
735 }
736 }
737 };
738
739 class ThreadInAsgct {
740 private:
741 Thread* _thread;
742 bool _saved_in_asgct;
743 public:
744 ThreadInAsgct(Thread* thread) : _thread(thread) {
745 assert(thread != nullptr, "invariant");
746 // Allow AsyncGetCallTrace to be reentrant - save the previous state.
747 _saved_in_asgct = thread->in_asgct();
748 thread->set_in_asgct(true);
749 }
750 ~ThreadInAsgct() {
751 assert(_thread->in_asgct(), "invariant");
752 _thread->set_in_asgct(_saved_in_asgct);
753 }
754 };
755
756 // Inline implementation of Thread::current()
757 inline Thread* Thread::current() {
758 Thread* current = current_or_null();
759 assert(current != nullptr, "Thread::current() called on detached thread");
760 return current;
761 }
762
763 inline Thread* Thread::current_or_null() {
764 return _thr_current;
765 }
766
767 inline Thread* Thread::current_or_null_safe() {
768 if (ThreadLocalStorage::is_initialized()) {
769 return ThreadLocalStorage::thread();
770 }
771 return nullptr;
772 }
773
774 #endif // SHARE_RUNTIME_THREAD_HPP