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 ICRefillVerifier;
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 private:
116
117 #ifndef USE_LIBRARY_BASED_TLS_ONLY
118 // Current thread is maintained as a thread-local variable
119 static THREAD_LOCAL Thread* _thr_current;
120 #endif
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 // Thread local data area available to the GC. The internal
142 // structure and contents of this data area is GC-specific.
143 // Only GC and GC barrier code should access this data area.
144 GCThreadLocalData _gc_data;
145
146 public:
147 static ByteSize gc_data_offset() {
148 return byte_offset_of(Thread, _gc_data);
149 }
150
151 template <typename T> T* gc_data() {
152 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
153 return reinterpret_cast<T*>(&_gc_data);
154 }
155
156 // Exception handling
157 // (Note: _pending_exception and friends are in ThreadShadow)
158 //oop _pending_exception; // pending exception for current thread
159 // const char* _exception_file; // file information for exception (debugging only)
160 // int _exception_line; // line information for exception (debugging only)
161 protected:
162
163 DEBUG_ONLY(static Thread* _starting_thread;)
164
165 // JavaThread lifecycle support:
166 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
167 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
168 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
169 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
170 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
171 friend class ThreadsListHandleTest; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
172 friend class ValidateHazardPtrsClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
173
174 ThreadsList* volatile _threads_hazard_ptr;
175 SafeThreadsListPtr* _threads_list_ptr;
176 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
177 ThreadsList* get_threads_hazard_ptr() const;
178 void set_threads_hazard_ptr(ThreadsList* new_list);
179 static bool is_hazard_ptr_tagged(ThreadsList* list) {
180 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
181 }
182 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
183 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
184 }
185 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
186 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
187 }
188 // This field is enabled via -XX:+EnableThreadSMRStatistics:
189 uint _nested_threads_hazard_ptr_cnt;
190 void dec_nested_threads_hazard_ptr_cnt() {
191 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
192 _nested_threads_hazard_ptr_cnt--;
193 }
194 void inc_nested_threads_hazard_ptr_cnt() {
195 _nested_threads_hazard_ptr_cnt++;
196 }
197 uint nested_threads_hazard_ptr_cnt() {
198 return _nested_threads_hazard_ptr_cnt;
199 }
200
201 public:
202 // Is the target JavaThread protected by the calling Thread or by some other
203 // mechanism?
204 static bool is_JavaThread_protected(const JavaThread* target);
205 // Is the target JavaThread protected by a ThreadsListHandle (TLH) associated
206 // with the calling Thread?
207 static bool is_JavaThread_protected_by_TLH(const JavaThread* target);
208
209 private:
210 DEBUG_ONLY(bool _suspendible_thread;)
211 DEBUG_ONLY(bool _indirectly_suspendible_thread;)
212 DEBUG_ONLY(bool _indirectly_safepoint_thread;)
213
214 public:
215 #ifdef ASSERT
216 void set_suspendible_thread() { _suspendible_thread = true; }
217 void clear_suspendible_thread() { _suspendible_thread = false; }
218 bool is_suspendible_thread() { return _suspendible_thread; }
219
220 void set_indirectly_suspendible_thread() { _indirectly_suspendible_thread = true; }
221 void clear_indirectly_suspendible_thread() { _indirectly_suspendible_thread = false; }
222 bool is_indirectly_suspendible_thread() { return _indirectly_suspendible_thread; }
223
224 void set_indirectly_safepoint_thread() { _indirectly_safepoint_thread = true; }
225 void clear_indirectly_safepoint_thread() { _indirectly_safepoint_thread = false; }
226 bool is_indirectly_safepoint_thread() { return _indirectly_safepoint_thread; }
227 #endif
228
229 private:
230 // Point to the last handle mark
231 HandleMark* _last_handle_mark;
232
233 // Claim value for parallel iteration over threads.
234 uintx _threads_do_token;
235
236 // Support for GlobalCounter
237 private:
238 volatile uintx _rcu_counter;
239 public:
240 volatile uintx* get_rcu_counter() {
241 return &_rcu_counter;
242 }
243
244 public:
245 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
246 HandleMark* last_handle_mark() const { return _last_handle_mark; }
247 private:
248
249 #ifdef ASSERT
250 ICRefillVerifier* _missed_ic_stub_refill_verifier;
251
252 public:
253 ICRefillVerifier* missed_ic_stub_refill_verifier() {
254 return _missed_ic_stub_refill_verifier;
255 }
256
257 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
258 _missed_ic_stub_refill_verifier = verifier;
259 }
260 #endif // ASSERT
261
262 private:
263 // Used by SkipGCALot class.
264 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
265
266 friend class GCLocker;
267
268 private:
269 ThreadLocalAllocBuffer _tlab; // Thread-local eden
270 jlong _allocated_bytes; // Cumulative number of bytes allocated on
271 // the Java heap
272 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
273
274 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
275
276 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
277
278 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
279 // is waiting to lock
280 public:
281 // Constructor
282 Thread(MEMFLAGS flag = mtThread);
283 virtual ~Thread() = 0; // Thread is abstract.
284
285 // Manage Thread::current()
286 void initialize_thread_current();
287 static void clear_thread_current(); // TLS cleanup needed before threads terminate
288
289 protected:
290 // To be implemented by children.
291 virtual void run() = 0;
292 virtual void pre_run() = 0;
293 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
294
295 #ifdef ASSERT
296 enum RunState {
297 PRE_CALL_RUN,
298 CALL_RUN,
299 PRE_RUN,
300 RUN,
301 POST_RUN
302 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
303 };
304 RunState _run_state; // for lifecycle checks
305 #endif
306
307
308 public:
309 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
310 void call_run();
311
312 // Testers
313 virtual bool is_VM_thread() const { return false; }
314 virtual bool is_Java_thread() const { return false; }
315 virtual bool is_Compiler_thread() const { return false; }
316 virtual bool is_service_thread() const { return false; }
317 virtual bool is_hidden_from_external_view() const { return false; }
318 virtual bool is_jvmti_agent_thread() const { return false; }
319 virtual bool is_Watcher_thread() const { return false; }
320 virtual bool is_ConcurrentGC_thread() const { return false; }
321 virtual bool is_Named_thread() const { return false; }
322 virtual bool is_Worker_thread() const { return false; }
323 virtual bool is_JfrSampler_thread() const { return false; }
324 virtual bool is_AttachListener_thread() const { return false; }
325 virtual bool is_monitor_deflation_thread() const { return false; }
326
327 // Convenience cast functions
328 CompilerThread* as_Compiler_thread() const {
329 assert(is_Compiler_thread(), "Must be compiler thread");
330 return (CompilerThread*)this;
331 }
332
333 // Can this thread make Java upcalls
334 virtual bool can_call_java() const { return false; }
335
336 // Is this a JavaThread that is on the VM's current ThreadsList?
337 // If so it must participate in the safepoint protocol.
338 virtual bool is_active_Java_thread() const { return false; }
339
340 // All threads are given names. For singleton subclasses we can
341 // just hard-wire the known name of the instance. JavaThreads and
342 // NamedThreads support multiple named instances, and dynamic
343 // changing of the name of an instance.
344 virtual const char* name() const { return "Unknown thread"; }
345
346 // A thread's type name is also made available for debugging
347 // and logging.
348 virtual const char* type_name() const { return "Thread"; }
349
350 // Returns the current thread (ASSERTS if null)
351 static inline Thread* current();
352 // Returns the current thread, or null if not attached
353 static inline Thread* current_or_null();
354 // Returns the current thread, or null if not attached, and is
355 // safe for use from signal-handlers
356 static inline Thread* current_or_null_safe();
357
358 // Common thread operations
359 #ifdef ASSERT
360 static void check_for_dangling_thread_pointer(Thread *thread);
361 #endif
362 static void set_priority(Thread* thread, ThreadPriority priority);
363 static void start(Thread* thread);
364
365 void set_native_thread_name(const char *name) {
366 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
367 os::set_native_thread_name(name);
368 }
369
370 // Support for Unhandled Oop detection
371 // Add the field for both, fastdebug and debug, builds to keep
372 // Thread's fields layout the same.
373 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
374 #ifdef CHECK_UNHANDLED_OOPS
375 private:
376 UnhandledOops* _unhandled_oops;
377 #elif defined(ASSERT)
378 private:
379 void* _unhandled_oops;
380 #endif
381 #ifdef CHECK_UNHANDLED_OOPS
382 public:
383 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
384 // Mark oop safe for gc. It may be stack allocated but won't move.
385 void allow_unhandled_oop(oop *op) {
386 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
387 }
388 // Clear oops at safepoint so crashes point to unhandled oop violator
389 void clear_unhandled_oops() {
390 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
391 }
392 #endif // CHECK_UNHANDLED_OOPS
393
394 public:
395 #ifndef PRODUCT
396 bool skip_gcalot() { return _skip_gcalot; }
397 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
398 #endif
399
400 // Resource area
401 ResourceArea* resource_area() const { return _resource_area; }
402 void set_resource_area(ResourceArea* area) { _resource_area = area; }
403
404 OSThread* osthread() const { return _osthread; }
405 void set_osthread(OSThread* thread) { _osthread = thread; }
406
407 // Internal handle support
408 HandleArea* handle_area() const { return _handle_area; }
409 void set_handle_area(HandleArea* area) { _handle_area = area; }
410
411 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
412 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
413
414 // Thread-Local Allocation Buffer (TLAB) support
415 ThreadLocalAllocBuffer& tlab() { return _tlab; }
416 void initialize_tlab();
417
418 jlong allocated_bytes() { return _allocated_bytes; }
419 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
420 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
421 inline jlong cooked_allocated_bytes();
422
423 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
424
425 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
426
427 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
428
429 // For tracking the Jvmti raw monitor the thread is pending on.
430 JvmtiRawMonitor* current_pending_raw_monitor() {
431 return _current_pending_raw_monitor;
432 }
433 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
434 _current_pending_raw_monitor = monitor;
435 }
436
437 // GC support
438 // Apply "f->do_oop" to all root oops in "this".
439 // Used by JavaThread::oops_do.
440 // Apply "cf->do_nmethod" (if !nullptr) to all nmethods active in frames
441 virtual void oops_do_no_frames(OopClosure* f, NMethodClosure* cf);
442 virtual void oops_do_frames(OopClosure* f, NMethodClosure* cf) {}
443 void oops_do(OopClosure* f, NMethodClosure* cf);
444
445 // Handles the parallel case for claim_threads_do.
446 private:
447 bool claim_par_threads_do(uintx claim_token);
448 public:
449 // Requires that "claim_token" is that of the current iteration.
450 // If "is_par" is false, sets the token of "this" to
451 // "claim_token", and returns "true". If "is_par" is true,
452 // uses an atomic instruction to set the current thread's token to
453 // "claim_token", if it is not already. Returns "true" iff the
454 // calling thread does the update, this indicates that the calling thread
455 // has claimed the thread in the current iteration.
456 bool claim_threads_do(bool is_par, uintx claim_token) {
457 if (!is_par) {
458 _threads_do_token = claim_token;
459 return true;
460 } else {
461 return claim_par_threads_do(claim_token);
462 }
463 }
464
465 uintx threads_do_token() const { return _threads_do_token; }
466
467 // jvmtiRedefineClasses support
468 void metadata_handles_do(void f(Metadata*));
469
470 private:
471 // Check if address is within the given range of this thread's
472 // stack: stack_base() > adr >/>= limit
473 // The check is inclusive of limit if passed true, else exclusive.
474 bool is_in_stack_range(address adr, address limit, bool inclusive) const {
475 assert(stack_base() > limit && limit >= stack_end(), "limit is outside of stack");
476 return stack_base() > adr && (inclusive ? adr >= limit : adr > limit);
477 }
478
479 public:
480 // Check if address is within the given range of this thread's
481 // stack: stack_base() > adr >= limit
482 bool is_in_stack_range_incl(address adr, address limit) const {
483 return is_in_stack_range(adr, limit, true);
484 }
485
486 // Check if address is within the given range of this thread's
487 // stack: stack_base() > adr > limit
488 bool is_in_stack_range_excl(address adr, address limit) const {
489 return is_in_stack_range(adr, limit, false);
490 }
491
492 // Check if address is in the stack mapped to this thread. Used mainly in
493 // error reporting (so has to include guard zone) and frame printing.
494 // Expects _stack_base to be initialized - checked with assert.
495 bool is_in_full_stack_checked(address adr) const {
496 return is_in_stack_range_incl(adr, stack_end());
497 }
498
499 // Like is_in_full_stack_checked but without the assertions as this
500 // may be called in a thread before _stack_base is initialized.
501 bool is_in_full_stack(address adr) const {
502 address stack_end = _stack_base - _stack_size;
503 return _stack_base > adr && adr >= stack_end;
504 }
505
506 // Check if address is in the live stack of this thread (not just for locks).
507 // Warning: can only be called by the current thread on itself.
508 bool is_in_live_stack(address adr) const {
509 assert(Thread::current() == this, "is_in_live_stack can only be called from current thread");
510 return is_in_stack_range_incl(adr, os::current_stack_pointer());
511 }
512
513 // Sets this thread as starting thread. Returns failure if thread
514 // creation fails due to lack of memory, too many threads etc.
515 bool set_as_starting_thread();
516
517 protected:
518 // OS data associated with the thread
519 OSThread* _osthread; // Platform-specific thread information
520
521 // Thread local resource area for temporary allocation within the VM
522 ResourceArea* _resource_area;
523
524 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
525
526 // Thread local handle area for allocation of handles within the VM
527 HandleArea* _handle_area;
528 GrowableArray<Metadata*>* _metadata_handles;
529
530 // Support for stack overflow handling, get_thread, etc.
531 address _stack_base;
532 size_t _stack_size;
533 int _lgrp_id;
534
535 public:
536 // Stack overflow support
537 address stack_base() const { assert(_stack_base != nullptr,"Sanity check"); return _stack_base; }
538 void set_stack_base(address base) { _stack_base = base; }
539 size_t stack_size() const { return _stack_size; }
540 void set_stack_size(size_t size) { _stack_size = size; }
541 address stack_end() const { return stack_base() - stack_size(); }
542 void record_stack_base_and_size();
543 void register_thread_stack_with_NMT();
544 void unregister_thread_stack_with_NMT();
545
546 int lgrp_id() const { return _lgrp_id; }
547 void set_lgrp_id(int value) { _lgrp_id = value; }
548
549 // Printing
550 void print_on(outputStream* st, bool print_extended_info) const;
551 virtual void print_on(outputStream* st) const { print_on(st, false); }
552 void print() const;
553 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
554 // Basic, non-virtual, printing support that is simple and always safe.
555 void print_value_on(outputStream* st) const;
556
557 // Debug-only code
558 #ifdef ASSERT
559 private:
560 // Deadlock detection support for Mutex locks. List of locks own by thread.
561 Mutex* _owned_locks;
562 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
563 // thus the friendship
564 friend class Mutex;
565 friend class Monitor;
566
567 public:
568 void print_owned_locks_on(outputStream* st) const;
569 void print_owned_locks() const { print_owned_locks_on(tty); }
570 Mutex* owned_locks() const { return _owned_locks; }
571 bool owns_locks() const { return owned_locks() != nullptr; }
572
573 // Deadlock detection
574 ResourceMark* current_resource_mark() { return _current_resource_mark; }
575 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
576 #endif // ASSERT
577
578 private:
579 volatile int _jvmti_env_iteration_count;
580
581 public:
582 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
583 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
584 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
585
586 // Code generation
587 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
588 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
589
590 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
591 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
592
593 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
594 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
595 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
596 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
597
598 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
599
600 public:
601 ParkEvent * volatile _ParkEvent; // for Object monitors, JVMTI raw monitors,
602 // and ObjectSynchronizer::read_stable_mark
603
604 // Termination indicator used by the signal handler.
605 // _ParkEvent is just a convenient field we can null out after setting the JavaThread termination state
606 // (which can't itself be read from the signal handler if a signal hits during the Thread destructor).
607 bool has_terminated() { return Atomic::load(&_ParkEvent) == nullptr; };
608
609 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
610 jint _hashStateX; // thread-specific hashCode generator state
611 jint _hashStateY;
612 jint _hashStateZ;
613
614 // Low-level leaf-lock primitives used to implement synchronization.
615 // Not for general synchronization use.
616 static void SpinAcquire(volatile int * Lock, const char * Name);
617 static void SpinRelease(volatile int * Lock);
618
619 #if defined(__APPLE__) && defined(AARCH64)
620 private:
621 DEBUG_ONLY(bool _wx_init);
622 WXMode _wx_state;
623 public:
624 void init_wx();
625 WXMode enable_wx(WXMode new_state);
626
627 void assert_wx_state(WXMode expected) {
628 assert(_wx_state == expected, "wrong state");
629 }
630 #endif // __APPLE__ && AARCH64
631
632 private:
633 bool _in_asgct = false;
634 public:
635 bool in_asgct() const { return _in_asgct; }
636 void set_in_asgct(bool value) { _in_asgct = value; }
637 static bool current_in_asgct() {
638 Thread *cur = Thread::current_or_null_safe();
639 return cur != nullptr && cur->in_asgct();
640 }
641
642 private:
643 VMErrorCallback* _vm_error_callbacks;
644
645 bool _profile_vm_locks;
646 bool _profile_vm_calls;
647 bool _profile_vm_ops;
648 bool _profile_rt_calls;
649 bool _profile_upcalls;
650
651 jlong _all_bc_counter_value;
652 jlong _clinit_bc_counter_value;
653
654 PerfTraceTime* _current_rt_call_timer;
655 public:
656 bool profile_vm_locks() const { return _profile_vm_locks; }
657 void set_profile_vm_locks(bool v) { _profile_vm_locks = v; }
658
659 bool profile_vm_calls() const { return _profile_vm_calls; }
660 void set_profile_vm_calls(bool v) { _profile_vm_calls = v; }
661
662 bool profile_vm_ops() const { return _profile_vm_ops; }
663 void set_profile_vm_ops(bool v) { _profile_vm_ops = v; }
664
665 bool profile_rt_calls() const { return _profile_rt_calls; }
666 void set_profile_rt_calls(bool v) { _profile_rt_calls = v; }
667
668 bool profile_upcalls() const { return _profile_upcalls; }
669 void set_profile_upcalls(bool v) { _profile_upcalls = v; }
670
671 PerfTraceTime* current_rt_call_timer() const { return _current_rt_call_timer; }
672 void set_current_rt_call_timer(PerfTraceTime* c) { _current_rt_call_timer = c; }
673 bool has_current_rt_call_timer() const { return _current_rt_call_timer != nullptr; }
674
675 bool do_profile_rt_call() const {
676 return ProfileRuntimeCalls && profile_rt_calls() && !has_current_rt_call_timer();
677 }
678
679 jlong bc_counter_value() const { return _all_bc_counter_value; }
680
681 jlong clinit_bc_counter_value() const { return _clinit_bc_counter_value; }
682
683 void inc_clinit_bc_counter_value(jlong l) { _clinit_bc_counter_value += l; }
684
685 static ByteSize bc_counter_offset() { return byte_offset_of(Thread, _all_bc_counter_value); }
686 };
687
688 class ProfileVMCallContext : StackObj {
689 private:
690 Thread* _thread;
691 bool _enabled;
692 PerfTraceTime* _timer;
693
694 static int _perf_nested_runtime_calls_count;
695
696 static const char* name(PerfTraceTime* t);
697 static void notify_nested_rt_call(PerfTraceTime* current, PerfTraceTime* inner_timer);
698 public:
699 inline ProfileVMCallContext(Thread* current, PerfTraceTime* timer, bool is_on)
700 : _thread(current), _enabled(is_on), _timer(timer) {
701 if (_enabled) {
702 assert(timer != nullptr, "");
703 assert(_thread->current_rt_call_timer() == nullptr, "%s", name(_thread->current_rt_call_timer()));
704 _thread->set_current_rt_call_timer(timer);
705 } else if (current->profile_rt_calls()) {
706 notify_nested_rt_call(current->current_rt_call_timer(), timer);
707 }
708 }
709
710 inline ~ProfileVMCallContext() {
711 if (_enabled) {
712 assert(_timer == _thread->current_rt_call_timer(),
713 "%s vs %s", name(_timer), name(_thread->current_rt_call_timer()));
714 _thread->set_current_rt_call_timer(nullptr);
715 }
716 }
717
718 static int nested_runtime_calls_count() { return _perf_nested_runtime_calls_count; };
719 };
720
721 class PauseRuntimeCallProfiling : public StackObj {
722 protected:
723 Thread* _thread;
724 bool _enabled;
725 PerfTraceTime* _timer;
726
727 public:
728 inline PauseRuntimeCallProfiling(Thread* current, bool is_on)
729 : _thread(current), _enabled(is_on), _timer(nullptr) {
730 if (_enabled) {
731 _timer = _thread->current_rt_call_timer();
732 _thread->set_current_rt_call_timer(nullptr);
733 }
734 }
735
736 inline ~PauseRuntimeCallProfiling () {
737 if (_enabled) {
738 guarantee(_thread->current_rt_call_timer() == nullptr, "");
739 _thread->set_current_rt_call_timer(_timer); // restore
740 }
741 }
742 };
743
744 class ThreadInAsgct {
745 private:
746 Thread* _thread;
747 bool _saved_in_asgct;
748 public:
749 ThreadInAsgct(Thread* thread) : _thread(thread) {
750 assert(thread != nullptr, "invariant");
751 // Allow AsyncGetCallTrace to be reentrant - save the previous state.
752 _saved_in_asgct = thread->in_asgct();
753 thread->set_in_asgct(true);
754 }
755 ~ThreadInAsgct() {
756 assert(_thread->in_asgct(), "invariant");
757 _thread->set_in_asgct(_saved_in_asgct);
758 }
759 };
760
761 // Inline implementation of Thread::current()
762 inline Thread* Thread::current() {
763 Thread* current = current_or_null();
764 assert(current != nullptr, "Thread::current() called on detached thread");
765 return current;
766 }
767
768 inline Thread* Thread::current_or_null() {
769 #ifndef USE_LIBRARY_BASED_TLS_ONLY
770 return _thr_current;
771 #else
772 if (ThreadLocalStorage::is_initialized()) {
773 return ThreadLocalStorage::thread();
774 }
775 return nullptr;
776 #endif
777 }
778
779 inline Thread* Thread::current_or_null_safe() {
780 if (ThreadLocalStorage::is_initialized()) {
781 return ThreadLocalStorage::thread();
782 }
783 return nullptr;
784 }
785
786 #endif // SHARE_RUNTIME_THREAD_HPP