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 #ifndef USE_LIBRARY_BASED_TLS_ONLY
119 // Current thread is maintained as a thread-local variable
120 static THREAD_LOCAL Thread* _thr_current;
121 #endif
122
123 // On AArch64, the high order 32 bits are used by a "patching epoch" number
124 // which reflects if this thread has executed the required fences, after
125 // an nmethod gets disarmed. The low order 32 bits denote the disarmed value.
126 uint64_t _nmethod_disarmed_guard_value;
127
128 public:
129 void set_nmethod_disarmed_guard_value(int value) {
130 _nmethod_disarmed_guard_value = (uint64_t)(uint32_t)value;
131 }
132
133 static ByteSize nmethod_disarmed_guard_value_offset() {
134 ByteSize offset = byte_offset_of(Thread, _nmethod_disarmed_guard_value);
135 // At least on x86_64, nmethod entry barrier encodes disarmed value offset
136 // in instruction as disp8 immed
137 assert(in_bytes(offset) < 128, "Offset >= 128");
138 return offset;
139 }
140
141 private:
142 // Poll data is used in generated code for safepoint polls.
143 // It is important for performance to put this at lower offset
144 // in Thread. The accessors are in JavaThread.
145 SafepointMechanism::ThreadData _poll_data;
146
147 // Thread local data area available to the GC. The internal
148 // structure and contents of this data area is GC-specific.
149 // Only GC and GC barrier code should access this data area.
150 GCThreadLocalData _gc_data;
151
152 public:
153 static ByteSize gc_data_offset() {
154 return byte_offset_of(Thread, _gc_data);
155 }
156
157 template <typename T> T* gc_data() {
158 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
159 return reinterpret_cast<T*>(&_gc_data);
160 }
161
162 // Exception handling
163 // (Note: _pending_exception and friends are in ThreadShadow)
164 //oop _pending_exception; // pending exception for current thread
165 // const char* _exception_file; // file information for exception (debugging only)
166 // int _exception_line; // line information for exception (debugging only)
167 protected:
168 // JavaThread lifecycle support:
169 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
170 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
171 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
172 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
173 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
174 friend class ThreadsListHandleTest; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
175 friend class ValidateHazardPtrsClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
176
177 ThreadsList* volatile _threads_hazard_ptr;
178 SafeThreadsListPtr* _threads_list_ptr;
179 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
180 ThreadsList* get_threads_hazard_ptr() const;
181 void set_threads_hazard_ptr(ThreadsList* new_list);
182 static bool is_hazard_ptr_tagged(ThreadsList* list) {
183 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
184 }
185 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
186 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
187 }
188 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
189 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
190 }
191 // This field is enabled via -XX:+EnableThreadSMRStatistics:
192 uint _nested_threads_hazard_ptr_cnt;
193 void dec_nested_threads_hazard_ptr_cnt() {
194 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
195 _nested_threads_hazard_ptr_cnt--;
196 }
197 void inc_nested_threads_hazard_ptr_cnt() {
198 _nested_threads_hazard_ptr_cnt++;
199 }
200 uint nested_threads_hazard_ptr_cnt() {
201 return _nested_threads_hazard_ptr_cnt;
202 }
203
204 public:
205 // Is the target JavaThread protected by the calling Thread or by some other
206 // mechanism?
207 static bool is_JavaThread_protected(const JavaThread* target);
208 // Is the target JavaThread protected by a ThreadsListHandle (TLH) associated
209 // with the calling Thread?
210 static bool is_JavaThread_protected_by_TLH(const JavaThread* target);
211
212 private:
213 DEBUG_ONLY(static Thread* _starting_thread;)
214 DEBUG_ONLY(bool _suspendible_thread;)
215 DEBUG_ONLY(bool _indirectly_suspendible_thread;)
216 DEBUG_ONLY(bool _indirectly_safepoint_thread;)
217
218 public:
219 #ifdef ASSERT
220 static bool is_starting_thread(const Thread* t);
221
222 void set_suspendible_thread() { _suspendible_thread = true; }
223 void clear_suspendible_thread() { _suspendible_thread = false; }
224 bool is_suspendible_thread() { return _suspendible_thread; }
225
226 void set_indirectly_suspendible_thread() { _indirectly_suspendible_thread = true; }
227 void clear_indirectly_suspendible_thread() { _indirectly_suspendible_thread = false; }
228 bool is_indirectly_suspendible_thread() { return _indirectly_suspendible_thread; }
229
230 void set_indirectly_safepoint_thread() { _indirectly_safepoint_thread = true; }
231 void clear_indirectly_safepoint_thread() { _indirectly_safepoint_thread = false; }
232 bool is_indirectly_safepoint_thread() { return _indirectly_safepoint_thread; }
233 #endif
234
235 private:
236 // Point to the last handle mark
237 HandleMark* _last_handle_mark;
238
239 // Claim value for parallel iteration over threads.
240 uintx _threads_do_token;
241
242 // Support for GlobalCounter
243 private:
244 volatile uintx _rcu_counter;
245 public:
246 volatile uintx* get_rcu_counter() {
247 return &_rcu_counter;
248 }
249
250 public:
251 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
252 HandleMark* last_handle_mark() const { return _last_handle_mark; }
253
254 private:
255 // Used by SkipGCALot class.
256 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
257
258 friend class GCLocker;
259
260 private:
261 ThreadLocalAllocBuffer _tlab; // Thread-local eden
262 jlong _allocated_bytes; // Cumulative number of bytes allocated on
263 // the Java heap
264 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
265
266 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
267
268 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
269
270 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
271 // is waiting to lock
272 public:
273 // Constructor
274 Thread(MemTag mem_tag = mtThread);
275 virtual ~Thread() = 0; // Thread is abstract.
276
277 // Manage Thread::current()
278 void initialize_thread_current();
279 static void clear_thread_current(); // TLS cleanup needed before threads terminate
280
281 protected:
282 // To be implemented by children.
283 virtual void run() = 0;
284 virtual void pre_run() = 0;
285 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
286
287 #ifdef ASSERT
288 enum RunState {
289 PRE_CALL_RUN,
290 CALL_RUN,
291 PRE_RUN,
292 RUN,
293 POST_RUN
294 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
295 };
296 RunState _run_state; // for lifecycle checks
297 #endif
298
299
300 public:
301 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
302 void call_run();
303
304 // Testers
305 virtual bool is_VM_thread() const { return false; }
306 virtual bool is_Java_thread() const { return false; }
307 virtual bool is_Compiler_thread() const { return false; }
308 virtual bool is_service_thread() const { return false; }
309 virtual bool is_hidden_from_external_view() const { return false; }
310 virtual bool is_jvmti_agent_thread() const { return false; }
311 virtual bool is_Watcher_thread() const { return false; }
312 virtual bool is_ConcurrentGC_thread() const { return false; }
313 virtual bool is_Named_thread() const { return false; }
314 virtual bool is_Worker_thread() const { return false; }
315 virtual bool is_JfrSampler_thread() const { return false; }
316 virtual bool is_AttachListener_thread() const { return false; }
317 virtual bool is_monitor_deflation_thread() const { return false; }
318
319 // Convenience cast functions
320 CompilerThread* as_Compiler_thread() const {
321 assert(is_Compiler_thread(), "Must be compiler thread");
322 return (CompilerThread*)this;
323 }
324
325 // Can this thread make Java upcalls
326 virtual bool can_call_java() const { return false; }
327
328 // Is this a JavaThread that is on the VM's current ThreadsList?
329 // If so it must participate in the safepoint protocol.
330 virtual bool is_active_Java_thread() const { return false; }
331
332 // All threads are given names. For singleton subclasses we can
333 // just hard-wire the known name of the instance. JavaThreads and
334 // NamedThreads support multiple named instances, and dynamic
335 // changing of the name of an instance.
336 virtual const char* name() const { return "Unknown thread"; }
337
338 // A thread's type name is also made available for debugging
339 // and logging.
340 virtual const char* type_name() const { return "Thread"; }
341
342 // Returns the current thread (ASSERTS if null)
343 static inline Thread* current();
344 // Returns the current thread, or null if not attached
345 static inline Thread* current_or_null();
346 // Returns the current thread, or null if not attached, and is
347 // safe for use from signal-handlers
348 static inline Thread* current_or_null_safe();
349
350 // Common thread operations
351 #ifdef ASSERT
352 static void check_for_dangling_thread_pointer(Thread *thread);
353 #endif
354 static void set_priority(Thread* thread, ThreadPriority priority);
355 static void start(Thread* thread);
356
357 void set_native_thread_name(const char *name) {
358 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
359 os::set_native_thread_name(name);
360 }
361
362 // Support for Unhandled Oop detection
363 // Add the field for both, fastdebug and debug, builds to keep
364 // Thread's fields layout the same.
365 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
366 #ifdef CHECK_UNHANDLED_OOPS
367 private:
368 UnhandledOops* _unhandled_oops;
369 #elif defined(ASSERT)
370 private:
371 void* _unhandled_oops;
372 #endif
373 #ifdef CHECK_UNHANDLED_OOPS
374 public:
375 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
376 // Mark oop safe for gc. It may be stack allocated but won't move.
377 void allow_unhandled_oop(oop *op) {
378 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
379 }
380 // Clear oops at safepoint so crashes point to unhandled oop violator
381 void clear_unhandled_oops() {
382 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
383 }
384 #endif // CHECK_UNHANDLED_OOPS
385
386 public:
387 #ifndef PRODUCT
388 bool skip_gcalot() { return _skip_gcalot; }
389 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
390 #endif
391
392 // Resource area
393 ResourceArea* resource_area() const { return _resource_area; }
394 void set_resource_area(ResourceArea* area) { _resource_area = area; }
395
396 OSThread* osthread() const { return _osthread; }
397 void set_osthread(OSThread* thread) { _osthread = thread; }
398
399 // Internal handle support
400 HandleArea* handle_area() const { return _handle_area; }
401 void set_handle_area(HandleArea* area) { _handle_area = area; }
402
403 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
404 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
405
406 // Thread-Local Allocation Buffer (TLAB) support
407 ThreadLocalAllocBuffer& tlab() { return _tlab; }
408 void initialize_tlab();
409
410 jlong allocated_bytes() { return _allocated_bytes; }
411 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
412 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
413 inline jlong cooked_allocated_bytes();
414
415 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
416
417 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
418
419 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
420
421 // For tracking the Jvmti raw monitor the thread is pending on.
422 JvmtiRawMonitor* current_pending_raw_monitor() {
423 return _current_pending_raw_monitor;
424 }
425 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
426 _current_pending_raw_monitor = monitor;
427 }
428
429 // GC support
430 // Apply "f->do_oop" to all root oops in "this".
431 // Used by JavaThread::oops_do.
432 // Apply "cf->do_nmethod" (if !nullptr) to all nmethods active in frames
433 virtual void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
434 virtual void oops_do_frames(OopClosure* f, NMethodClosure* cf) {}
435 void oops_do(OopClosure* f, NMethodClosure* cf);
436
437 // Handles the parallel case for claim_threads_do.
438 private:
439 bool claim_par_threads_do(uintx claim_token);
440 public:
441 // Requires that "claim_token" is that of the current iteration.
442 // If "is_par" is false, sets the token of "this" to
443 // "claim_token", and returns "true". If "is_par" is true,
444 // uses an atomic instruction to set the current thread's token to
445 // "claim_token", if it is not already. Returns "true" iff the
446 // calling thread does the update, this indicates that the calling thread
447 // has claimed the thread in the current iteration.
448 bool claim_threads_do(bool is_par, uintx claim_token) {
449 if (!is_par) {
450 _threads_do_token = claim_token;
451 return true;
452 } else {
453 return claim_par_threads_do(claim_token);
454 }
455 }
456
457 uintx threads_do_token() const { return _threads_do_token; }
458
459 // jvmtiRedefineClasses support
460 void metadata_handles_do(void f(Metadata*));
461
462 private:
463 // Check if address is within the given range of this thread's
464 // stack: stack_base() > adr >/>= limit
465 // The check is inclusive of limit if passed true, else exclusive.
466 bool is_in_stack_range(address adr, address limit, bool inclusive) const {
467 assert(stack_base() > limit && limit >= stack_end(), "limit is outside of stack");
468 return stack_base() > adr && (inclusive ? adr >= limit : adr > limit);
469 }
470
471 public:
472 // Check if address is within the given range of this thread's
473 // stack: stack_base() > adr >= limit
474 bool is_in_stack_range_incl(address adr, address limit) const {
475 return is_in_stack_range(adr, limit, true);
476 }
477
478 // Check if address is within the given range of this thread's
479 // stack: stack_base() > adr > limit
480 bool is_in_stack_range_excl(address adr, address limit) const {
481 return is_in_stack_range(adr, limit, false);
482 }
483
484 // Check if address is in the stack mapped to this thread. Used mainly in
485 // error reporting (so has to include guard zone) and frame printing.
486 // Expects _stack_base to be initialized - checked with assert.
487 bool is_in_full_stack_checked(address adr) const {
488 return is_in_stack_range_incl(adr, stack_end());
489 }
490
491 // Like is_in_full_stack_checked but without the assertions as this
492 // may be called in a thread before _stack_base is initialized.
493 bool is_in_full_stack(address adr) const {
494 address stack_end = _stack_base - _stack_size;
495 return _stack_base > adr && adr >= stack_end;
496 }
497
498 // Check if address is in the live stack of this thread (not just for locks).
499 // Warning: can only be called by the current thread on itself.
500 bool is_in_live_stack(address adr) const {
501 assert(Thread::current() == this, "is_in_live_stack can only be called from current thread");
502 return is_in_stack_range_incl(adr, os::current_stack_pointer());
503 }
504
505 // Sets the argument thread as starting thread. Returns failure if thread
506 // creation fails due to lack of memory, too many threads etc.
507 static bool set_as_starting_thread(JavaThread* jt);
508
509 protected:
510 // OS data associated with the thread
511 OSThread* _osthread; // Platform-specific thread information
512
513 // Thread local resource area for temporary allocation within the VM
514 ResourceArea* _resource_area;
515
516 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
517
518 // Thread local handle area for allocation of handles within the VM
519 HandleArea* _handle_area;
520 GrowableArray<Metadata*>* _metadata_handles;
521
522 // Support for stack overflow handling, get_thread, etc.
523 address _stack_base;
524 size_t _stack_size;
525 int _lgrp_id;
526
527 public:
528 // Stack overflow support
529 address stack_base() const DEBUG_ONLY(;) NOT_DEBUG({ return _stack_base; })
530 // Needed for code that can query a new thread before the stack has been set.
531 address stack_base_or_null() const { return _stack_base; }
532 void set_stack_base(address base) { _stack_base = base; }
533 size_t stack_size() const { return _stack_size; }
534 void set_stack_size(size_t size) { _stack_size = size; }
535 address stack_end() const { return stack_base() - stack_size(); }
536 void record_stack_base_and_size();
537 void register_thread_stack_with_NMT();
538 void unregister_thread_stack_with_NMT();
539
540 int lgrp_id() const { return _lgrp_id; }
541 void set_lgrp_id(int value) { _lgrp_id = value; }
542
543 // Printing
544 void print_on(outputStream* st, bool print_extended_info) const;
545 virtual void print_on(outputStream* st) const { print_on(st, false); }
546 void print() const;
547 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
548 // Basic, non-virtual, printing support that is simple and always safe.
549 void print_value_on(outputStream* st) const;
550
551 // Debug-only code
552 #ifdef ASSERT
553 private:
554 // Deadlock detection support for Mutex locks. List of locks own by thread.
555 Mutex* _owned_locks;
556 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
557 // thus the friendship
558 friend class Mutex;
559 friend class Monitor;
560
561 public:
562 void print_owned_locks_on(outputStream* st) const;
563 void print_owned_locks() const { print_owned_locks_on(tty); }
564 Mutex* owned_locks() const { return _owned_locks; }
565 bool owns_locks() const { return owned_locks() != nullptr; }
566
567 // Deadlock detection
568 ResourceMark* current_resource_mark() { return _current_resource_mark; }
569 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
570 #endif // ASSERT
571
572 private:
573 volatile int _jvmti_env_iteration_count;
574
575 public:
576 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
577 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
578 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
579
580 // Code generation
581 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
582 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
583
584 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
585 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
586
587 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
588 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
589 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
590 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
591
592 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
593
594 public:
595 ParkEvent * volatile _ParkEvent; // for Object monitors, JVMTI raw monitors,
596 // and ObjectSynchronizer::read_stable_mark
597
598 // Termination indicator used by the signal handler.
599 // _ParkEvent is just a convenient field we can null out after setting the JavaThread termination state
600 // (which can't itself be read from the signal handler if a signal hits during the Thread destructor).
601 bool has_terminated() { return Atomic::load(&_ParkEvent) == nullptr; };
602
603 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
604 jint _hashStateX; // thread-specific hashCode generator state
605 jint _hashStateY;
606 jint _hashStateZ;
607
608 // Low-level leaf-lock primitives used to implement synchronization.
609 // Not for general synchronization use.
610 static void SpinAcquire(volatile int * Lock, const char * Name);
611 static void SpinRelease(volatile int * Lock);
612
613 #if defined(__APPLE__) && defined(AARCH64)
614 private:
615 DEBUG_ONLY(bool _wx_init);
616 WXMode _wx_state;
617 public:
618 void init_wx();
619 WXMode enable_wx(WXMode new_state);
620
621 void assert_wx_state(WXMode expected) {
622 assert(_wx_state == expected, "wrong state");
623 }
624 #endif // __APPLE__ && AARCH64
625
626 private:
627 bool _in_asgct = false;
628 public:
629 bool in_asgct() const { return _in_asgct; }
630 void set_in_asgct(bool value) { _in_asgct = value; }
631 static bool current_in_asgct() {
632 Thread *cur = Thread::current_or_null_safe();
633 return cur != nullptr && cur->in_asgct();
634 }
635
636 private:
637 VMErrorCallback* _vm_error_callbacks;
638
639 bool _profile_vm_locks;
640 bool _profile_vm_calls;
641 bool _profile_vm_ops;
642 bool _profile_rt_calls;
643 bool _profile_upcalls;
644
645 jlong _all_bc_counter_value;
646 jlong _clinit_bc_counter_value;
647
648 PerfTraceTime* _current_rt_call_timer;
649 public:
650 bool profile_vm_locks() const { return _profile_vm_locks; }
651 void set_profile_vm_locks(bool v) { _profile_vm_locks = v; }
652
653 bool profile_vm_calls() const { return _profile_vm_calls; }
654 void set_profile_vm_calls(bool v) { _profile_vm_calls = v; }
655
656 bool profile_vm_ops() const { return _profile_vm_ops; }
657 void set_profile_vm_ops(bool v) { _profile_vm_ops = v; }
658
659 bool profile_rt_calls() const { return _profile_rt_calls; }
660 void set_profile_rt_calls(bool v) { _profile_rt_calls = v; }
661
662 bool profile_upcalls() const { return _profile_upcalls; }
663 void set_profile_upcalls(bool v) { _profile_upcalls = v; }
664
665 PerfTraceTime* current_rt_call_timer() const { return _current_rt_call_timer; }
666 void set_current_rt_call_timer(PerfTraceTime* c) { _current_rt_call_timer = c; }
667 bool has_current_rt_call_timer() const { return _current_rt_call_timer != nullptr; }
668
669 bool do_profile_rt_call() const {
670 return ProfileRuntimeCalls && profile_rt_calls() && !has_current_rt_call_timer();
671 }
672
673 jlong bc_counter_value() const { return _all_bc_counter_value; }
674
675 jlong clinit_bc_counter_value() const { return _clinit_bc_counter_value; }
676
677 void inc_clinit_bc_counter_value(jlong l) { _clinit_bc_counter_value += l; }
678
679 static ByteSize bc_counter_offset() { return byte_offset_of(Thread, _all_bc_counter_value); }
680 };
681
682 class ProfileVMCallContext : StackObj {
683 private:
684 Thread* _thread;
685 bool _enabled;
686 PerfTraceTime* _timer;
687
688 static int _perf_nested_runtime_calls_count;
689
690 static const char* name(PerfTraceTime* t);
691 static void notify_nested_rt_call(PerfTraceTime* current, PerfTraceTime* inner_timer);
692 public:
693 inline ProfileVMCallContext(Thread* current, PerfTraceTime* timer, bool is_on)
694 : _thread(current), _enabled(is_on), _timer(timer) {
695 if (_enabled) {
696 assert(timer != nullptr, "");
697 assert(_thread->current_rt_call_timer() == nullptr, "%s", name(_thread->current_rt_call_timer()));
698 _thread->set_current_rt_call_timer(timer);
699 } else if (current->profile_rt_calls()) {
700 notify_nested_rt_call(current->current_rt_call_timer(), timer);
701 }
702 }
703
704 inline ~ProfileVMCallContext() {
705 if (_enabled) {
706 assert(_timer == _thread->current_rt_call_timer(),
707 "%s vs %s", name(_timer), name(_thread->current_rt_call_timer()));
708 _thread->set_current_rt_call_timer(nullptr);
709 }
710 }
711
712 static int nested_runtime_calls_count() { return _perf_nested_runtime_calls_count; };
713 };
714
715 class PauseRuntimeCallProfiling : public StackObj {
716 protected:
717 Thread* _thread;
718 bool _enabled;
719 PerfTraceTime* _timer;
720
721 public:
722 inline PauseRuntimeCallProfiling(Thread* current, bool is_on)
723 : _thread(current), _enabled(is_on), _timer(nullptr) {
724 if (_enabled) {
725 _timer = _thread->current_rt_call_timer();
726 _thread->set_current_rt_call_timer(nullptr);
727 }
728 }
729
730 inline ~PauseRuntimeCallProfiling () {
731 if (_enabled) {
732 guarantee(_thread->current_rt_call_timer() == nullptr, "");
733 _thread->set_current_rt_call_timer(_timer); // restore
734 }
735 }
736 };
737
738 class ThreadInAsgct {
739 private:
740 Thread* _thread;
741 bool _saved_in_asgct;
742 public:
743 ThreadInAsgct(Thread* thread) : _thread(thread) {
744 assert(thread != nullptr, "invariant");
745 // Allow AsyncGetCallTrace to be reentrant - save the previous state.
746 _saved_in_asgct = thread->in_asgct();
747 thread->set_in_asgct(true);
748 }
749 ~ThreadInAsgct() {
750 assert(_thread->in_asgct(), "invariant");
751 _thread->set_in_asgct(_saved_in_asgct);
752 }
753 };
754
755 // Inline implementation of Thread::current()
756 inline Thread* Thread::current() {
757 Thread* current = current_or_null();
758 assert(current != nullptr, "Thread::current() called on detached thread");
759 return current;
760 }
761
762 inline Thread* Thread::current_or_null() {
763 #ifndef USE_LIBRARY_BASED_TLS_ONLY
764 return _thr_current;
765 #else
766 if (ThreadLocalStorage::is_initialized()) {
767 return ThreadLocalStorage::thread();
768 }
769 return nullptr;
770 #endif
771 }
772
773 inline Thread* Thread::current_or_null_safe() {
774 if (ThreadLocalStorage::is_initialized()) {
775 return ThreadLocalStorage::thread();
776 }
777 return nullptr;
778 }
779
780 #endif // SHARE_RUNTIME_THREAD_HPP