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