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