1 /*
2 * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_THREAD_HPP
26 #define SHARE_RUNTIME_THREAD_HPP
27
28 #include "jni.h"
29 #include "gc/shared/gcThreadLocalData.hpp"
30 #include "gc/shared/threadLocalAllocBuffer.hpp"
31 #include "memory/allocation.hpp"
32 #include "oops/oop.hpp"
33 #include "prims/jvmtiExport.hpp"
34 #include "runtime/frame.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handshake.hpp"
37 #include "runtime/javaFrameAnchor.hpp"
38 #include "runtime/jniHandles.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/os.hpp"
41 #include "runtime/osThread.hpp"
42 #include "runtime/park.hpp"
43 #include "runtime/stubRoutines.hpp"
44 #include "runtime/threadHeapSampler.hpp"
45 #include "runtime/threadLocalStorage.hpp"
46 #include "runtime/threadStatisticalInfo.hpp"
47 #include "runtime/unhandledOops.hpp"
48 #include "utilities/align.hpp"
49 #include "utilities/exceptions.hpp"
50 #include "utilities/globalDefinitions.hpp"
51 #include "utilities/macros.hpp"
52 #if INCLUDE_JFR
53 #include "jfr/support/jfrThreadExtension.hpp"
54 #endif
55
56
57 class SafeThreadsListPtr;
58 class ThreadSafepointState;
59 class ThreadsList;
60 class ThreadsSMRSupport;
61
62 class JvmtiRawMonitor;
63 class JvmtiThreadState;
64 class ThreadStatistics;
65 class ConcurrentLocksDump;
66 class ParkEvent;
67 class Parker;
68 class MonitorInfo;
69
70 class AbstractCompiler;
71 class ciEnv;
72 class CompileThread;
73 class CompileLog;
74 class CompileTask;
75 class CompileQueue;
76 class CompilerCounters;
77
78 class vframeArray;
79 class vframe;
80 class javaVFrame;
81
82 class DeoptResourceMark;
83 class JvmtiDeferredUpdates;
84 class jvmtiDeferredLocalVariableSet;
85
86 class ThreadClosure;
87 class ICRefillVerifier;
88 class IdealGraphPrinter;
89
90 class JVMCIEnv;
91 class JVMCIPrimitiveArray;
92
93 class Metadata;
94 class ResourceArea;
95
96 DEBUG_ONLY(class ResourceMark;)
97
98 class WorkerThread;
99
100 // Class hierarchy
101 // - Thread
102 // - JavaThread
103 // - various subclasses eg CompilerThread, ServiceThread
104 // - NonJavaThread
105 // - NamedThread
106 // - VMThread
107 // - ConcurrentGCThread
108 // - WorkerThread
109 // - GangWorker
110 // - WatcherThread
111 // - JfrThreadSampler
112 //
113 // All Thread subclasses must be either JavaThread or NonJavaThread.
114 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
115 // a partially constructed/destroyed Thread.
116
117 // Thread execution sequence and actions:
118 // All threads:
119 // - thread_native_entry // per-OS native entry point
120 // - stack initialization
121 // - other OS-level initialization (signal masks etc)
122 // - handshake with creating thread (if not started suspended)
123 // - this->call_run() // common shared entry point
124 // - shared common initialization
125 // - this->pre_run() // virtual per-thread-type initialization
126 // - this->run() // virtual per-thread-type "main" logic
127 // - shared common tear-down
128 // - this->post_run() // virtual per-thread-type tear-down
129 // - // 'this' no longer referenceable
130 // - OS-level tear-down (minimal)
131 // - final logging
132 //
133 // For JavaThread:
134 // - this->run() // virtual but not normally overridden
135 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
136 // - this->entry_point() // set differently for each kind of JavaThread
137
138 class Thread: public ThreadShadow {
139 friend class VMStructs;
140 friend class JVMCIVMStructs;
141 private:
142
143 #ifndef USE_LIBRARY_BASED_TLS_ONLY
144 // Current thread is maintained as a thread-local variable
145 static THREAD_LOCAL Thread* _thr_current;
146 #endif
147
148 // Thread local data area available to the GC. The internal
149 // structure and contents of this data area is GC-specific.
150 // Only GC and GC barrier code should access this data area.
151 GCThreadLocalData _gc_data;
152
153 public:
154 static ByteSize gc_data_offset() {
155 return byte_offset_of(Thread, _gc_data);
156 }
157
158 template <typename T> T* gc_data() {
159 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
160 return reinterpret_cast<T*>(&_gc_data);
161 }
162
163 // Exception handling
164 // (Note: _pending_exception and friends are in ThreadShadow)
165 //oop _pending_exception; // pending exception for current thread
166 // const char* _exception_file; // file information for exception (debugging only)
167 // int _exception_line; // line information for exception (debugging only)
168 protected:
169
170 DEBUG_ONLY(static Thread* _starting_thread;)
171
172 // Support for forcing alignment of thread objects for biased locking
173 void* _real_malloc_address;
174
175 // JavaThread lifecycle support:
176 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
177 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
178 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
179 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
180 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
181
182 ThreadsList* volatile _threads_hazard_ptr;
183 SafeThreadsListPtr* _threads_list_ptr;
184 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
185 ThreadsList* get_threads_hazard_ptr();
186 void set_threads_hazard_ptr(ThreadsList* new_list);
187 static bool is_hazard_ptr_tagged(ThreadsList* list) {
188 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
189 }
190 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
191 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
192 }
193 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
194 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
195 }
196 // This field is enabled via -XX:+EnableThreadSMRStatistics:
197 uint _nested_threads_hazard_ptr_cnt;
198 void dec_nested_threads_hazard_ptr_cnt() {
199 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
200 _nested_threads_hazard_ptr_cnt--;
201 }
202 void inc_nested_threads_hazard_ptr_cnt() {
203 _nested_threads_hazard_ptr_cnt++;
204 }
205 uint nested_threads_hazard_ptr_cnt() {
206 return _nested_threads_hazard_ptr_cnt;
207 }
208
209 public:
210 void* operator new(size_t size) throw() { return allocate(size, true); }
211 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
212 return allocate(size, false); }
213 void operator delete(void* p);
214
215 protected:
216 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
217 private:
218
219 // ***************************************************************
220 // Suspend and resume support
221 // ***************************************************************
222 //
223 // VM suspend/resume no longer exists - it was once used for various
224 // things including safepoints but was deprecated and finally removed
225 // in Java 7. Because VM suspension was considered "internal" Java-level
226 // suspension was considered "external", and this legacy naming scheme
227 // remains.
228 //
229 // External suspend/resume requests come from JVM_SuspendThread,
230 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
231 // ResumeThread. External
232 // suspend requests cause _external_suspend to be set and external
233 // resume requests cause _external_suspend to be cleared.
234 // External suspend requests do not nest on top of other external
235 // suspend requests. The higher level APIs reject suspend requests
236 // for already suspended threads.
237 //
238 // The external_suspend
239 // flag is checked by has_special_runtime_exit_condition() and java thread
240 // will self-suspend when handle_special_runtime_exit_condition() is
241 // called. Most uses of the _thread_blocked state in JavaThreads are
242 // considered the same as being externally suspended; if the blocking
243 // condition lifts, the JavaThread will self-suspend. Other places
244 // where VM checks for external_suspend include:
245 // + mutex granting (do not enter monitors when thread is suspended)
246 // + state transitions from _thread_in_native
247 //
248 // In general, java_suspend() does not wait for an external suspend
249 // request to complete. When it returns, the only guarantee is that
250 // the _external_suspend field is true.
251 //
252 // wait_for_ext_suspend_completion() is used to wait for an external
253 // suspend request to complete. External suspend requests are usually
254 // followed by some other interface call that requires the thread to
255 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
256 // the interface that requires quiescence, we give the JavaThread a
257 // chance to self-suspend before we need it to be quiescent. This
258 // improves overall suspend/query performance.
259 //
260 // _suspend_flags controls the behavior of java_ suspend/resume.
261 // It must be set under the protection of SR_lock. Read from the flag is
262 // OK without SR_lock as long as the value is only used as a hint.
263 // (e.g., check _external_suspend first without lock and then recheck
264 // inside SR_lock and finish the suspension)
265 //
266 // _suspend_flags is also overloaded for other "special conditions" so
267 // that a single check indicates whether any special action is needed
268 // eg. for async exceptions.
269 // -------------------------------------------------------------------
270 // Notes:
271 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
272 // but we still update its value to keep other part of the system (mainly
273 // JVMTI) happy. ThreadState is legacy code (see notes in
274 // osThread.hpp).
275 //
276 // 2. It would be more natural if set_external_suspend() is private and
277 // part of java_suspend(), but that probably would affect the suspend/query
278 // performance. Need more investigation on this.
279
280 // suspend/resume lock: used for self-suspend
281 Monitor* _SR_lock;
282
283 protected:
284 enum SuspendFlags {
285 // NOTE: avoid using the sign-bit as cc generates different test code
286 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
287
288 _external_suspend = 0x20000000U, // thread is asked to self suspend
289 _ext_suspended = 0x40000000U, // thread has self-suspended
290
291 _has_async_exception = 0x00000001U, // there is a pending async exception
292 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
293
294 _trace_flag = 0x00000004U, // call tracing backend
295 _ea_obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
296 };
297
298 // various suspension related flags - atomically updated
299 // overloaded for async exception checking in check_special_condition_for_native_trans.
300 volatile uint32_t _suspend_flags;
301
302 private:
303 int _num_nested_signal;
304
305 DEBUG_ONLY(bool _suspendible_thread;)
306
307 public:
308 void enter_signal_handler() { _num_nested_signal++; }
309 void leave_signal_handler() { _num_nested_signal--; }
310 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
311
312 // Determines if a heap allocation failure will be retried
313 // (e.g., by deoptimizing and re-executing in the interpreter).
314 // In this case, the failed allocation must raise
315 // Universe::out_of_memory_error_retry() and omit side effects
316 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
317 // and -XX:OnOutOfMemoryError.
318 virtual bool in_retryable_allocation() const { return false; }
319
320 #ifdef ASSERT
321 void set_suspendible_thread() {
322 _suspendible_thread = true;
323 }
324
325 void clear_suspendible_thread() {
326 _suspendible_thread = false;
327 }
328
329 bool is_suspendible_thread() { return _suspendible_thread; }
330 #endif
331
332 private:
333 // Active_handles points to a block of handles
334 JNIHandleBlock* _active_handles;
335
336 // One-element thread local free list
337 JNIHandleBlock* _free_handle_block;
338
339 // Point to the last handle mark
340 HandleMark* _last_handle_mark;
341
342 // Claim value for parallel iteration over threads.
343 uintx _threads_do_token;
344
345 // Support for GlobalCounter
346 private:
347 volatile uintx _rcu_counter;
348 public:
349 volatile uintx* get_rcu_counter() {
350 return &_rcu_counter;
351 }
352
353 public:
354 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
355 HandleMark* last_handle_mark() const { return _last_handle_mark; }
356 private:
357
358 #ifdef ASSERT
359 ICRefillVerifier* _missed_ic_stub_refill_verifier;
360
361 public:
362 ICRefillVerifier* missed_ic_stub_refill_verifier() {
363 return _missed_ic_stub_refill_verifier;
364 }
365
366 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
367 _missed_ic_stub_refill_verifier = verifier;
368 }
369 #endif // ASSERT
370
371 private:
372
373 // Debug support for checking if code allows safepoints or not.
374 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
375 // mutex, or blocking on an object synchronizer (Java locking).
376 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
377 // the above cases.
378 //
379 // The class NoSafepointVerifier is used to set this counter.
380 //
381 NOT_PRODUCT(int _no_safepoint_count;) // If 0, thread allow a safepoint to happen
382
383 private:
384 // Used by SkipGCALot class.
385 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
386
387 friend class GCLocker;
388 friend class NoSafepointVerifier;
389 friend class PauseNoSafepointVerifier;
390
391 volatile void* _polling_page; // Thread local polling page
392
393 ThreadLocalAllocBuffer _tlab; // Thread-local eden
394 jlong _allocated_bytes; // Cumulative number of bytes allocated on
395 // the Java heap
396 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
397
398 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
399
400 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
401
402 int _vm_operation_started_count; // VM_Operation support
403 int _vm_operation_completed_count; // VM_Operation support
404
405 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
406 // is waiting to lock
407 bool _current_pending_monitor_is_from_java; // locking is from Java code
408 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
409 // is waiting to lock
410
411
412 // ObjectMonitor on which this thread called Object.wait()
413 ObjectMonitor* _current_waiting_monitor;
414
415 // Per-thread ObjectMonitor lists:
416 public:
417 ObjectMonitor* om_free_list; // SLL of free ObjectMonitors
418 int om_free_count; // # on om_free_list
419 int om_free_provision; // # to try to allocate next
420 ObjectMonitor* om_in_use_list; // SLL of in-use ObjectMonitors
421 int om_in_use_count; // # on om_in_use_list
422
423 #ifdef ASSERT
424 private:
425 volatile uint64_t _visited_for_critical_count;
426
427 public:
428 void set_visited_for_critical_count(uint64_t safepoint_id) {
429 assert(_visited_for_critical_count == 0, "Must be reset before set");
430 assert((safepoint_id & 0x1) == 1, "Must be odd");
431 _visited_for_critical_count = safepoint_id;
432 }
433 void reset_visited_for_critical_count(uint64_t safepoint_id) {
434 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
435 _visited_for_critical_count = 0;
436 }
437 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
438 return _visited_for_critical_count == safepoint_id;
439 }
440 #endif
441
442 public:
443 enum {
444 is_definitely_current_thread = true
445 };
446
447 // Constructor
448 Thread();
449 virtual ~Thread() = 0; // Thread is abstract.
450
451 // Manage Thread::current()
452 void initialize_thread_current();
453 static void clear_thread_current(); // TLS cleanup needed before threads terminate
454
455 protected:
456 // To be implemented by children.
457 virtual void run() = 0;
458 virtual void pre_run() = 0;
459 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
460
461 #ifdef ASSERT
462 enum RunState {
463 PRE_CALL_RUN,
464 CALL_RUN,
465 PRE_RUN,
466 RUN,
467 POST_RUN
468 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
469 };
470 RunState _run_state; // for lifecycle checks
471 #endif
472
473
474 public:
475 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
476 void call_run();
477
478 // Testers
479 virtual bool is_VM_thread() const { return false; }
480 virtual bool is_Java_thread() const { return false; }
481 virtual bool is_Compiler_thread() const { return false; }
482 virtual bool is_Code_cache_sweeper_thread() const { return false; }
483 virtual bool is_service_thread() const { return false; }
484 virtual bool is_hidden_from_external_view() const { return false; }
485 virtual bool is_jvmti_agent_thread() const { return false; }
486 // True iff the thread can perform GC operations at a safepoint.
487 // Generally will be true only of VM thread and parallel GC WorkGang
488 // threads.
489 virtual bool is_GC_task_thread() const { return false; }
490 virtual bool is_Watcher_thread() const { return false; }
491 virtual bool is_ConcurrentGC_thread() const { return false; }
492 virtual bool is_Named_thread() const { return false; }
493 virtual bool is_Worker_thread() const { return false; }
494
495 // Can this thread make Java upcalls
496 virtual bool can_call_java() const { return false; }
497
498 // Is this a JavaThread that is on the VM's current ThreadsList?
499 // If so it must participate in the safepoint protocol.
500 virtual bool is_active_Java_thread() const { return false; }
501
502 // Casts
503 virtual WorkerThread* as_Worker_thread() const { return NULL; }
504
505 virtual char* name() const { return (char*)"Unknown thread"; }
506
507 // Returns the current thread (ASSERTS if NULL)
508 static inline Thread* current();
509 // Returns the current thread, or NULL if not attached
510 static inline Thread* current_or_null();
511 // Returns the current thread, or NULL if not attached, and is
512 // safe for use from signal-handlers
513 static inline Thread* current_or_null_safe();
514
515 // Common thread operations
516 #ifdef ASSERT
517 static void check_for_dangling_thread_pointer(Thread *thread);
518 #endif
519 static void set_priority(Thread* thread, ThreadPriority priority);
520 static ThreadPriority get_priority(const Thread* const thread);
521 static void start(Thread* thread);
522
523 void set_native_thread_name(const char *name) {
524 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
525 os::set_native_thread_name(name);
526 }
527
528 Monitor* SR_lock() const { return _SR_lock; }
529
530 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
531
532 inline void set_suspend_flag(SuspendFlags f);
533 inline void clear_suspend_flag(SuspendFlags f);
534
535 inline void set_has_async_exception();
536 inline void clear_has_async_exception();
537
538 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
539
540 inline void set_critical_native_unlock();
541 inline void clear_critical_native_unlock();
542
543 inline void set_trace_flag();
544 inline void clear_trace_flag();
545
546 inline void set_ea_obj_deopt_flag();
547 inline void clear_ea_obj_deopt_flag();
548
549 // Support for Unhandled Oop detection
550 // Add the field for both, fastdebug and debug, builds to keep
551 // Thread's fields layout the same.
552 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
553 #ifdef CHECK_UNHANDLED_OOPS
554 private:
555 UnhandledOops* _unhandled_oops;
556 #elif defined(ASSERT)
557 private:
558 void* _unhandled_oops;
559 #endif
560 #ifdef CHECK_UNHANDLED_OOPS
561 public:
562 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
563 // Mark oop safe for gc. It may be stack allocated but won't move.
564 void allow_unhandled_oop(oop *op) {
565 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
566 }
567 // Clear oops at safepoint so crashes point to unhandled oop violator
568 void clear_unhandled_oops() {
569 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
570 }
571 #endif // CHECK_UNHANDLED_OOPS
572
573 public:
574 #ifndef PRODUCT
575 bool skip_gcalot() { return _skip_gcalot; }
576 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
577 #endif
578
579 // Installs a pending exception to be inserted later
580 static void send_async_exception(oop thread_oop, oop java_throwable);
581
582 // Resource area
583 ResourceArea* resource_area() const { return _resource_area; }
584 void set_resource_area(ResourceArea* area) { _resource_area = area; }
585
586 OSThread* osthread() const { return _osthread; }
587 void set_osthread(OSThread* thread) { _osthread = thread; }
588
589 // JNI handle support
590 JNIHandleBlock* active_handles() const { return _active_handles; }
591 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
592 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
593 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
594
595 // Internal handle support
596 HandleArea* handle_area() const { return _handle_area; }
597 void set_handle_area(HandleArea* area) { _handle_area = area; }
598
599 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
600 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
601
602 // Thread-Local Allocation Buffer (TLAB) support
603 ThreadLocalAllocBuffer& tlab() { return _tlab; }
604 void initialize_tlab() {
605 if (UseTLAB) {
606 tlab().initialize();
607 }
608 }
609
610 jlong allocated_bytes() { return _allocated_bytes; }
611 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
612 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
613 inline jlong cooked_allocated_bytes();
614
615 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
616
617 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
618
619 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
620
621 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
622
623 bool is_ea_obj_deopt_suspend() { return (_suspend_flags & _ea_obj_deopt) != 0; }
624
625 // VM operation support
626 int vm_operation_ticket() { return ++_vm_operation_started_count; }
627 int vm_operation_completed_count() { return _vm_operation_completed_count; }
628 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
629
630 // For tracking the heavyweight monitor the thread is pending on.
631 ObjectMonitor* current_pending_monitor() {
632 return _current_pending_monitor;
633 }
634 void set_current_pending_monitor(ObjectMonitor* monitor) {
635 _current_pending_monitor = monitor;
636 }
637 void set_current_pending_monitor_is_from_java(bool from_java) {
638 _current_pending_monitor_is_from_java = from_java;
639 }
640 bool current_pending_monitor_is_from_java() {
641 return _current_pending_monitor_is_from_java;
642 }
643
644 // For tracking the ObjectMonitor on which this thread called Object.wait()
645 ObjectMonitor* current_waiting_monitor() {
646 return _current_waiting_monitor;
647 }
648 void set_current_waiting_monitor(ObjectMonitor* monitor) {
649 _current_waiting_monitor = monitor;
650 }
651
652 // For tracking the Jvmti raw monitor the thread is pending on.
653 JvmtiRawMonitor* current_pending_raw_monitor() {
654 return _current_pending_raw_monitor;
655 }
656 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
657 _current_pending_raw_monitor = monitor;
658 }
659
660 // GC support
661 // Apply "f->do_oop" to all root oops in "this".
662 // Used by JavaThread::oops_do.
663 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
664 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
665
666 // Handles the parallel case for claim_threads_do.
667 private:
668 bool claim_par_threads_do(uintx claim_token);
669 public:
670 // Requires that "claim_token" is that of the current iteration.
671 // If "is_par" is false, sets the token of "this" to
672 // "claim_token", and returns "true". If "is_par" is true,
673 // uses an atomic instruction to set the current thread's token to
674 // "claim_token", if it is not already. Returns "true" iff the
675 // calling thread does the update, this indicates that the calling thread
676 // has claimed the thread in the current iteration.
677 bool claim_threads_do(bool is_par, uintx claim_token) {
678 if (!is_par) {
679 _threads_do_token = claim_token;
680 return true;
681 } else {
682 return claim_par_threads_do(claim_token);
683 }
684 }
685
686 uintx threads_do_token() const { return _threads_do_token; }
687
688 // jvmtiRedefineClasses support
689 void metadata_handles_do(void f(Metadata*));
690
691 private:
692 // Check if address is within the given range of this thread's
693 // stack: stack_base() > adr >/>= limit
694 // The check is inclusive of limit if passed true, else exclusive.
695 bool is_in_stack_range(address adr, address limit, bool inclusive) const {
696 assert(stack_base() > limit && limit >= stack_end(), "limit is outside of stack");
697 return stack_base() > adr && (inclusive ? adr >= limit : adr > limit);
698 }
699
700 public:
701 // Used by fast lock support
702 virtual bool is_lock_owned(address adr) const;
703
704 // Check if address is within the given range of this thread's
705 // stack: stack_base() > adr >= limit
706 bool is_in_stack_range_incl(address adr, address limit) const {
707 return is_in_stack_range(adr, limit, true);
708 }
709
710 // Check if address is within the given range of this thread's
711 // stack: stack_base() > adr > limit
712 bool is_in_stack_range_excl(address adr, address limit) const {
713 return is_in_stack_range(adr, limit, false);
714 }
715
716 // Check if address is in the stack mapped to this thread. Used mainly in
717 // error reporting (so has to include guard zone) and frame printing.
718 // Expects _stack_base to be initialized - checked with assert.
719 bool is_in_full_stack_checked(address adr) const {
720 return is_in_stack_range_incl(adr, stack_end());
721 }
722
723 // Like is_in_full_stack_checked but without the assertions as this
724 // may be called in a thread before _stack_base is initialized.
725 bool is_in_full_stack(address adr) const {
726 address stack_end = _stack_base - _stack_size;
727 return _stack_base > adr && adr >= stack_end;
728 }
729
730 // Check if address is in the live stack of this thread (not just for locks).
731 // Warning: can only be called by the current thread on itself.
732 bool is_in_live_stack(address adr) const {
733 assert(Thread::current() == this, "is_in_live_stack can only be called from current thread");
734 return is_in_stack_range_incl(adr, os::current_stack_pointer());
735 }
736
737 // Sets this thread as starting thread. Returns failure if thread
738 // creation fails due to lack of memory, too many threads etc.
739 bool set_as_starting_thread();
740
741 protected:
742 // OS data associated with the thread
743 OSThread* _osthread; // Platform-specific thread information
744
745 // Thread local resource area for temporary allocation within the VM
746 ResourceArea* _resource_area;
747
748 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
749
750 // Thread local handle area for allocation of handles within the VM
751 HandleArea* _handle_area;
752 GrowableArray<Metadata*>* _metadata_handles;
753
754 // Support for stack overflow handling, get_thread, etc.
755 address _stack_base;
756 size_t _stack_size;
757 int _lgrp_id;
758
759 volatile void** polling_page_addr() { return &_polling_page; }
760
761 public:
762 // Stack overflow support
763 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
764 void set_stack_base(address base) { _stack_base = base; }
765 size_t stack_size() const { return _stack_size; }
766 void set_stack_size(size_t size) { _stack_size = size; }
767 address stack_end() const { return stack_base() - stack_size(); }
768 void record_stack_base_and_size();
769 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
770
771 int lgrp_id() const { return _lgrp_id; }
772 void set_lgrp_id(int value) { _lgrp_id = value; }
773
774 // Printing
775 void print_on(outputStream* st, bool print_extended_info) const;
776 virtual void print_on(outputStream* st) const { print_on(st, false); }
777 void print() const;
778 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
779 void print_value_on(outputStream* st) const;
780
781 // Debug-only code
782 #ifdef ASSERT
783 private:
784 // Deadlock detection support for Mutex locks. List of locks own by thread.
785 Mutex* _owned_locks;
786 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
787 // thus the friendship
788 friend class Mutex;
789 friend class Monitor;
790
791 public:
792 void print_owned_locks_on(outputStream* st) const;
793 void print_owned_locks() const { print_owned_locks_on(tty); }
794 Mutex* owned_locks() const { return _owned_locks; }
795 bool owns_locks() const { return owned_locks() != NULL; }
796
797 // Deadlock detection
798 ResourceMark* current_resource_mark() { return _current_resource_mark; }
799 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
800 #endif // ASSERT
801
802 // These functions check conditions on a JavaThread before possibly going to a safepoint,
803 // including NoSafepointVerifier.
804 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
805 void check_possible_safepoint() NOT_DEBUG_RETURN;
806
807 private:
808 volatile int _jvmti_env_iteration_count;
809
810 public:
811 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
812 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
813 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
814
815 // Code generation
816 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
817 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
818 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
819
820 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
821 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
822
823 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
824
825 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
826 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
827 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
828 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
829
830 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
831
832 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
833
834 public:
835 volatile intptr_t _Stalled;
836 volatile int _TypeTag;
837 ParkEvent * _ParkEvent; // for Object monitors and JVMTI raw monitors
838 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
839 int NativeSyncRecursion; // diagnostic
840
841 volatile int _OnTrap; // Resume-at IP delta
842 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
843 jint _hashStateX; // thread-specific hashCode generator state
844 jint _hashStateY;
845 jint _hashStateZ;
846
847 // Low-level leaf-lock primitives used to implement synchronization
848 // and native monitor-mutex infrastructure.
849 // Not for general synchronization use.
850 static void SpinAcquire(volatile int * Lock, const char * Name);
851 static void SpinRelease(volatile int * Lock);
852 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
853 static void muxRelease(volatile intptr_t * Lock);
854 };
855
856 // Inline implementation of Thread::current()
857 inline Thread* Thread::current() {
858 Thread* current = current_or_null();
859 assert(current != NULL, "Thread::current() called on detached thread");
860 return current;
861 }
862
863 inline Thread* Thread::current_or_null() {
864 #ifndef USE_LIBRARY_BASED_TLS_ONLY
865 return _thr_current;
866 #else
867 if (ThreadLocalStorage::is_initialized()) {
868 return ThreadLocalStorage::thread();
869 }
870 return NULL;
871 #endif
872 }
873
874 inline Thread* Thread::current_or_null_safe() {
875 if (ThreadLocalStorage::is_initialized()) {
876 return ThreadLocalStorage::thread();
877 }
878 return NULL;
879 }
880
881 class NonJavaThread: public Thread {
882 friend class VMStructs;
883
884 NonJavaThread* volatile _next;
885
886 class List;
887 static List _the_list;
888
889 void add_to_the_list();
890 void remove_from_the_list();
891
892 protected:
893 virtual void pre_run();
894 virtual void post_run();
895
896 public:
897 NonJavaThread();
898 ~NonJavaThread();
899
900 class Iterator;
901 };
902
903 // Provides iteration over the list of NonJavaThreads.
904 // List addition occurs in pre_run(), and removal occurs in post_run(),
905 // so that only live fully-initialized threads can be found in the list.
906 // Threads created after an iterator is constructed will not be visited
907 // by the iterator. The scope of an iterator is a critical section; there
908 // must be no safepoint checks in that scope.
909 class NonJavaThread::Iterator : public StackObj {
910 uint _protect_enter;
911 NonJavaThread* _current;
912
913 NONCOPYABLE(Iterator);
914
915 public:
916 Iterator();
917 ~Iterator();
918
919 bool end() const { return _current == NULL; }
920 NonJavaThread* current() const { return _current; }
921 void step();
922 };
923
924 // Name support for threads. non-JavaThread subclasses with multiple
925 // uniquely named instances should derive from this.
926 class NamedThread: public NonJavaThread {
927 friend class VMStructs;
928 enum {
929 max_name_len = 64
930 };
931 private:
932 char* _name;
933 // log JavaThread being processed by oops_do
934 JavaThread* _processed_thread;
935 uint _gc_id; // The current GC id when a thread takes part in GC
936
937 public:
938 NamedThread();
939 ~NamedThread();
940 // May only be called once per thread.
941 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
942 virtual bool is_Named_thread() const { return true; }
943 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
944 JavaThread *processed_thread() { return _processed_thread; }
945 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
946 virtual void print_on(outputStream* st) const;
947
948 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
949 uint gc_id() { return _gc_id; }
950 };
951
952 // Worker threads are named and have an id of an assigned work.
953 class WorkerThread: public NamedThread {
954 private:
955 uint _id;
956 public:
957 WorkerThread() : _id(0) { }
958 virtual bool is_Worker_thread() const { return true; }
959
960 virtual WorkerThread* as_Worker_thread() const {
961 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
962 return (WorkerThread*) this;
963 }
964
965 void set_id(uint work_id) { _id = work_id; }
966 uint id() const { return _id; }
967 };
968
969 // A single WatcherThread is used for simulating timer interrupts.
970 class WatcherThread: public NonJavaThread {
971 friend class VMStructs;
972 protected:
973 virtual void run();
974
975 private:
976 static WatcherThread* _watcher_thread;
977
978 static bool _startable;
979 // volatile due to at least one lock-free read
980 volatile static bool _should_terminate;
981 public:
982 enum SomeConstants {
983 delay_interval = 10 // interrupt delay in milliseconds
984 };
985
986 // Constructor
987 WatcherThread();
988
989 // No destruction allowed
990 ~WatcherThread() {
991 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
992 }
993
994 // Tester
995 bool is_Watcher_thread() const { return true; }
996
997 // Printing
998 char* name() const { return (char*)"VM Periodic Task Thread"; }
999 void print_on(outputStream* st) const;
1000 void unpark();
1001
1002 // Returns the single instance of WatcherThread
1003 static WatcherThread* watcher_thread() { return _watcher_thread; }
1004
1005 // Create and start the single instance of WatcherThread, or stop it on shutdown
1006 static void start();
1007 static void stop();
1008 // Only allow start once the VM is sufficiently initialized
1009 // Otherwise the first task to enroll will trigger the start
1010 static void make_startable();
1011 private:
1012 int sleep() const;
1013 };
1014
1015
1016 class CompilerThread;
1017
1018 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
1019
1020 class JavaThread: public Thread {
1021 friend class VMStructs;
1022 friend class JVMCIVMStructs;
1023 friend class WhiteBox;
1024 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
1025 private:
1026 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
1027 oop _threadObj; // The Java level thread object
1028
1029 #ifdef ASSERT
1030 private:
1031 int _java_call_counter;
1032
1033 public:
1034 int java_call_counter() { return _java_call_counter; }
1035 void inc_java_call_counter() { _java_call_counter++; }
1036 void dec_java_call_counter() {
1037 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1038 _java_call_counter--;
1039 }
1040 private: // restore original namespace restriction
1041 #endif // ifdef ASSERT
1042
1043 #ifndef PRODUCT
1044 public:
1045 enum {
1046 jump_ring_buffer_size = 16
1047 };
1048 private: // restore original namespace restriction
1049 #endif
1050
1051 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1052
1053 ThreadFunction _entry_point;
1054
1055 JNIEnv _jni_environment;
1056
1057 // Deopt support
1058 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1059
1060 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1061 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1062 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1063 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
1064 // will be carried out as soon as possible, which, in most cases, is just before deoptimization of
1065 // the frame, when control returns to it.
1066 JvmtiDeferredUpdates* _jvmti_deferred_updates;
1067
1068 // Handshake value for fixing 6243940. We need a place for the i2c
1069 // adapter to store the callee Method*. This value is NEVER live
1070 // across a gc point so it does NOT have to be gc'd
1071 // The handshake is open ended since we can't be certain that it will
1072 // be NULLed. This is because we rarely ever see the race and end up
1073 // in handle_wrong_method which is the backend of the handshake. See
1074 // code in i2c adapters and handle_wrong_method.
1075
1076 Method* _callee_target;
1077
1078 // Used to pass back results to the interpreter or generated code running Java code.
1079 oop _vm_result; // oop result is GC-preserved
1080 Metadata* _vm_result_2; // non-oop result
1081
1082 // See ReduceInitialCardMarks: this holds the precise space interval of
1083 // the most recent slow path allocation for which compiled code has
1084 // elided card-marks for performance along the fast-path.
1085 MemRegion _deferred_card_mark;
1086
1087 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1088 // allocated during deoptimization
1089 // and by JNI_MonitorEnter/Exit
1090
1091 // Async. requests support
1092 enum AsyncRequests {
1093 _no_async_condition = 0,
1094 _async_exception,
1095 _async_unsafe_access_error
1096 };
1097 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1098 oop _pending_async_exception;
1099
1100 // Safepoint support
1101 public: // Expose _thread_state for SafeFetchInt()
1102 volatile JavaThreadState _thread_state;
1103 private:
1104 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1105 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1106
1107 // JavaThread termination support
1108 enum TerminatedTypes {
1109 _not_terminated = 0xDEAD - 2,
1110 _thread_exiting, // JavaThread::exit() has been called for this thread
1111 _thread_terminated, // JavaThread is removed from thread list
1112 _vm_exited // JavaThread is still executing native code, but VM is terminated
1113 // only VM_Exit can set _vm_exited
1114 };
1115
1116 // In general a JavaThread's _terminated field transitions as follows:
1117 //
1118 // _not_terminated => _thread_exiting => _thread_terminated
1119 //
1120 // _vm_exited is a special value to cover the case of a JavaThread
1121 // executing native code after the VM itself is terminated.
1122 volatile TerminatedTypes _terminated;
1123 // suspend/resume support
1124 volatile bool _suspend_equivalent; // Suspend equivalent condition
1125 jint _in_deopt_handler; // count of deoptimization
1126 // handlers thread is in
1127 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1128 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1129 // never locked) when throwing an exception. Used by interpreter only.
1130
1131 // JNI attach states:
1132 enum JNIAttachStates {
1133 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1134 _attaching_via_jni, // thread is attaching via JNI
1135 _attached_via_jni // thread has attached via JNI
1136 };
1137
1138 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1139 // A native thread that is attaching via JNI starts with a value
1140 // of _attaching_via_jni and transitions to _attached_via_jni.
1141 volatile JNIAttachStates _jni_attach_state;
1142
1143 public:
1144 // State of the stack guard pages for this thread.
1145 enum StackGuardState {
1146 stack_guard_unused, // not needed
1147 stack_guard_reserved_disabled,
1148 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1149 stack_guard_enabled // enabled
1150 };
1151
1152 private:
1153
1154 #if INCLUDE_JVMCI
1155 // The _pending_* fields below are used to communicate extra information
1156 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1157
1158 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1159 int _pending_deoptimization;
1160
1161 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1162 // before the monitor has been acquired.
1163 bool _pending_monitorenter;
1164
1165 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1166 bool _pending_transfer_to_interpreter;
1167
1168 // True if in a runtime call from compiled code that will deoptimize
1169 // and re-execute a failed heap allocation in the interpreter.
1170 bool _in_retryable_allocation;
1171
1172 // An id of a speculation that JVMCI compiled code can use to further describe and
1173 // uniquely identify the speculative optimization guarded by the uncommon trap
1174 jlong _pending_failed_speculation;
1175
1176 // These fields are mutually exclusive in terms of live ranges.
1177 union {
1178 // Communicates the pc at which the most recent implicit exception occurred
1179 // from the signal handler to a deoptimization stub.
1180 address _implicit_exception_pc;
1181
1182 // Communicates an alternative call target to an i2c stub from a JavaCall .
1183 address _alternate_call_target;
1184 } _jvmci;
1185
1186 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1187 jlong* _jvmci_counters;
1188
1189 public:
1190 static jlong* _jvmci_old_thread_counters;
1191 static void collect_counters(jlong* array, int length);
1192 void resize_counters(int current_size, int new_size);
1193 static void resize_all_jvmci_counters(int new_size);
1194
1195 private:
1196 #endif // INCLUDE_JVMCI
1197
1198 StackGuardState _stack_guard_state;
1199
1200 // Precompute the limit of the stack as used in stack overflow checks.
1201 // We load it from here to simplify the stack overflow check in assembly.
1202 address _stack_overflow_limit;
1203 address _reserved_stack_activation;
1204
1205 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1206 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1207 // code)
1208 volatile oop _exception_oop; // Exception thrown in compiled code
1209 volatile address _exception_pc; // PC where exception happened
1210 volatile address _exception_handler_pc; // PC for handler of exception
1211 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1212
1213 private:
1214 // support for JNI critical regions
1215 jint _jni_active_critical; // count of entries into JNI critical region
1216
1217 // Checked JNI: function name requires exception check
1218 char* _pending_jni_exception_check_fn;
1219
1220 // For deadlock detection.
1221 int _depth_first_number;
1222
1223 // JVMTI PopFrame support
1224 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1225 int _popframe_condition;
1226
1227 // If reallocation of scalar replaced objects fails, we throw OOM
1228 // and during exception propagation, pop the top
1229 // _frames_to_pop_failed_realloc frames, the ones that reference
1230 // failed reallocations.
1231 int _frames_to_pop_failed_realloc;
1232
1233 friend class VMThread;
1234 friend class ThreadWaitTransition;
1235 friend class VM_Exit;
1236
1237 void initialize(); // Initialized the instance variables
1238
1239 public:
1240 // Constructor
1241 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1242 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1243 ~JavaThread();
1244
1245 #ifdef ASSERT
1246 // verify this JavaThread hasn't be published in the Threads::list yet
1247 void verify_not_published();
1248 #endif // ASSERT
1249
1250 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1251 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1252 _jni_environment.functions = functionTable;
1253 }
1254 struct JNINativeInterface_* get_jni_functions() {
1255 return (struct JNINativeInterface_ *)_jni_environment.functions;
1256 }
1257
1258 // This function is called at thread creation to allow
1259 // platform specific thread variables to be initialized.
1260 void cache_global_variables();
1261
1262 // Executes Shutdown.shutdown()
1263 void invoke_shutdown_hooks();
1264
1265 // Cleanup on thread exit
1266 enum ExitType {
1267 normal_exit,
1268 jni_detach
1269 };
1270 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1271
1272 void cleanup_failed_attach_current_thread(bool is_daemon);
1273
1274 // Testers
1275 virtual bool is_Java_thread() const { return true; }
1276 virtual bool can_call_java() const { return true; }
1277
1278 virtual bool is_active_Java_thread() const {
1279 return on_thread_list() && !is_terminated();
1280 }
1281
1282 // Thread oop. threadObj() can be NULL for initial JavaThread
1283 // (or for threads attached via JNI)
1284 oop threadObj() const { return _threadObj; }
1285 void set_threadObj(oop p) { _threadObj = p; }
1286
1287 // Prepare thread and add to priority queue. If a priority is
1288 // not specified, use the priority of the thread object. Threads_lock
1289 // must be held while this function is called.
1290 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1291
1292 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1293 address saved_exception_pc() { return _saved_exception_pc; }
1294
1295
1296 ThreadFunction entry_point() const { return _entry_point; }
1297
1298 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1299 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1300
1301 // Last frame anchor routines
1302
1303 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1304
1305 // last_Java_sp
1306 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1307 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1308
1309 // last_Java_pc
1310
1311 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1312
1313 // Safepoint support
1314 inline JavaThreadState thread_state() const;
1315 inline void set_thread_state(JavaThreadState s);
1316 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1317 inline ThreadSafepointState* safepoint_state() const;
1318 inline void set_safepoint_state(ThreadSafepointState* state);
1319 inline bool is_at_poll_safepoint();
1320
1321 // JavaThread termination and lifecycle support:
1322 void smr_delete();
1323 bool on_thread_list() const { return _on_thread_list; }
1324 void set_on_thread_list() { _on_thread_list = true; }
1325
1326 // thread has called JavaThread::exit() or is terminated
1327 bool is_exiting() const;
1328 // thread is terminated (no longer on the threads list); we compare
1329 // against the two non-terminated values so that a freed JavaThread
1330 // will also be considered terminated.
1331 bool check_is_terminated(TerminatedTypes l_terminated) const {
1332 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1333 }
1334 bool is_terminated() const;
1335 void set_terminated(TerminatedTypes t);
1336 // special for Threads::remove() which is static:
1337 void set_terminated_value();
1338 void block_if_vm_exited();
1339
1340 bool doing_unsafe_access() { return _doing_unsafe_access; }
1341 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1342
1343 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1344 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1345
1346 inline void set_polling_page_release(void* poll_value);
1347 inline void set_polling_page(void* poll_value);
1348 inline volatile void* get_polling_page();
1349
1350 private:
1351 // Support for thread handshake operations
1352 HandshakeState _handshake;
1353 public:
1354 void set_handshake_operation(HandshakeOperation* op) {
1355 _handshake.set_operation(op);
1356 }
1357
1358 bool has_handshake() const {
1359 return _handshake.has_operation();
1360 }
1361
1362 void handshake_process_by_self() {
1363 _handshake.process_by_self();
1364 }
1365
1366 HandshakeState::ProcessResult handshake_try_process(HandshakeOperation* op) {
1367 return _handshake.try_process(op);
1368 }
1369
1370 #ifdef ASSERT
1371 Thread* active_handshaker() const {
1372 return _handshake.active_handshaker();
1373 }
1374 #endif
1375
1376 // Suspend/resume support for JavaThread
1377 private:
1378 inline void set_ext_suspended();
1379 inline void clear_ext_suspended();
1380
1381 // Synchronize with another thread (most likely a JVMTI agent) that is deoptimizing objects of the
1382 // current thread, i.e. reverts optimizations based on escape analysis.
1383 void wait_for_object_deoptimization();
1384
1385 public:
1386 void java_suspend(); // higher-level suspension logic called by the public APIs
1387 void java_resume(); // higher-level resume logic called by the public APIs
1388 int java_suspend_self(); // low-level self-suspension mechanics
1389
1390 private:
1391 // mid-level wrapper around java_suspend_self to set up correct state and
1392 // check for a pending safepoint at the end
1393 void java_suspend_self_with_safepoint_check();
1394
1395 public:
1396 void check_and_wait_while_suspended() {
1397 assert(JavaThread::current() == this, "sanity check");
1398
1399 bool do_self_suspend;
1400 do {
1401 // were we externally suspended while we were waiting?
1402 do_self_suspend = handle_special_suspend_equivalent_condition();
1403 if (do_self_suspend) {
1404 // don't surprise the thread that suspended us by returning
1405 java_suspend_self();
1406 set_suspend_equivalent();
1407 }
1408 } while (do_self_suspend);
1409 }
1410 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1411 // Check for async exception in addition to safepoint and suspend request.
1412 static void check_special_condition_for_native_trans(JavaThread *thread);
1413
1414 // Same as check_special_condition_for_native_trans but finishes the
1415 // transition into thread_in_Java mode so that it can potentially
1416 // block.
1417 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1418
1419 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1420 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1421 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1422 // Warning: is_ext_suspend_completed() may temporarily drop the
1423 // SR_lock to allow the thread to reach a stable thread state if
1424 // it is currently in a transient thread state.
1425 return is_ext_suspend_completed(false /* !called_by_wait */,
1426 SuspendRetryDelay, bits);
1427 }
1428
1429 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1430 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1431 // passed as the count and delay parameters. Experiments with specific
1432 // calls to wait_for_ext_suspend_completion() can be done by passing
1433 // other values in the code. Experiments with all calls can be done
1434 // via the appropriate -XX options.
1435 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1436
1437 // test for suspend - most (all?) of these should go away
1438 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1439
1440 inline void set_external_suspend();
1441 inline void clear_external_suspend();
1442
1443 bool is_external_suspend() const {
1444 return (_suspend_flags & _external_suspend) != 0;
1445 }
1446 // Whenever a thread transitions from native to vm/java it must suspend
1447 // if external|deopt suspend is present.
1448 bool is_suspend_after_native() const {
1449 return (_suspend_flags & (_external_suspend | _ea_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
1450 }
1451
1452 // external suspend request is completed
1453 bool is_ext_suspended() const {
1454 return (_suspend_flags & _ext_suspended) != 0;
1455 }
1456
1457 bool is_external_suspend_with_lock() const {
1458 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1459 return is_external_suspend();
1460 }
1461
1462 // Special method to handle a pending external suspend request
1463 // when a suspend equivalent condition lifts.
1464 bool handle_special_suspend_equivalent_condition() {
1465 assert(is_suspend_equivalent(),
1466 "should only be called in a suspend equivalence condition");
1467 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1468 bool ret = is_external_suspend();
1469 if (!ret) {
1470 // not about to self-suspend so clear suspend equivalence
1471 clear_suspend_equivalent();
1472 }
1473 // implied else:
1474 // We have a pending external suspend request so we leave the
1475 // suspend_equivalent flag set until java_suspend_self() sets
1476 // the ext_suspended flag and clears the suspend_equivalent
1477 // flag. This insures that wait_for_ext_suspend_completion()
1478 // will return consistent values.
1479 return ret;
1480 }
1481
1482 // utility methods to see if we are doing some kind of suspension
1483 bool is_being_ext_suspended() const {
1484 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1485 return is_ext_suspended() || is_external_suspend();
1486 }
1487
1488 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1489
1490 void set_suspend_equivalent() { _suspend_equivalent = true; }
1491 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1492
1493 // Thread.stop support
1494 void send_thread_stop(oop throwable);
1495 AsyncRequests clear_special_runtime_exit_condition() {
1496 AsyncRequests x = _special_runtime_exit_condition;
1497 _special_runtime_exit_condition = _no_async_condition;
1498 return x;
1499 }
1500
1501 // Are any async conditions present?
1502 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1503
1504 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1505
1506 // these next two are also used for self-suspension and async exception support
1507 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1508
1509 // Return true if JavaThread has an asynchronous condition or
1510 // if external suspension is requested.
1511 bool has_special_runtime_exit_condition() {
1512 // Because we don't use is_external_suspend_with_lock
1513 // it is possible that we won't see an asynchronous external suspend
1514 // request that has just gotten started, i.e., SR_lock grabbed but
1515 // _external_suspend field change either not made yet or not visible
1516 // yet. However, this is okay because the request is asynchronous and
1517 // we will see the new flag value the next time through. It's also
1518 // possible that the external suspend request is dropped after
1519 // we have checked is_external_suspend(), we will recheck its value
1520 // under SR_lock in java_suspend_self().
1521 return (_special_runtime_exit_condition != _no_async_condition) ||
1522 is_external_suspend() || is_trace_suspend() || is_ea_obj_deopt_suspend();
1523 }
1524
1525 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1526
1527 inline void set_pending_async_exception(oop e);
1528
1529 // Fast-locking support
1530 bool is_lock_owned(address adr) const;
1531
1532 // Accessors for vframe array top
1533 // The linked list of vframe arrays are sorted on sp. This means when we
1534 // unpack the head must contain the vframe array to unpack.
1535 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1536 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1537
1538 // Side structure for deferring update of java frame locals until deopt occurs
1539 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
1540 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
1541
1542 // These only really exist to make debugging deopt problems simpler
1543
1544 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1545 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1546
1547 // The special resourceMark used during deoptimization
1548
1549 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1550 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1551
1552 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1553 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1554
1555 Method* callee_target() const { return _callee_target; }
1556 void set_callee_target (Method* x) { _callee_target = x; }
1557
1558 // Oop results of vm runtime calls
1559 oop vm_result() const { return _vm_result; }
1560 void set_vm_result (oop x) { _vm_result = x; }
1561
1562 Metadata* vm_result_2() const { return _vm_result_2; }
1563 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1564
1565 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1566 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1567
1568 #if INCLUDE_JVMCI
1569 int pending_deoptimization() const { return _pending_deoptimization; }
1570 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1571 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1572 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1573 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1574 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1575 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1576 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1577 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1578
1579 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1580 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1581 #endif // INCLUDE_JVMCI
1582
1583 // Exception handling for compiled methods
1584 oop exception_oop() const;
1585 address exception_pc() const { return _exception_pc; }
1586 address exception_handler_pc() const { return _exception_handler_pc; }
1587 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1588
1589 void set_exception_oop(oop o);
1590 void set_exception_pc(address a) { _exception_pc = a; }
1591 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1592 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1593
1594 void clear_exception_oop_and_pc() {
1595 set_exception_oop(NULL);
1596 set_exception_pc(NULL);
1597 }
1598
1599 // Stack overflow support
1600 //
1601 // (small addresses)
1602 //
1603 // -- <-- stack_end() ---
1604 // | |
1605 // | red pages |
1606 // | |
1607 // -- <-- stack_red_zone_base() |
1608 // | |
1609 // | guard
1610 // | yellow pages zone
1611 // | |
1612 // | |
1613 // -- <-- stack_yellow_zone_base() |
1614 // | |
1615 // | |
1616 // | reserved pages |
1617 // | |
1618 // -- <-- stack_reserved_zone_base() --- ---
1619 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1620 // | zone
1621 // \|/ size
1622 // some untouched memory ---
1623 //
1624 //
1625 // --
1626 // |
1627 // | shadow zone
1628 // |
1629 // --
1630 // x frame n
1631 // --
1632 // x frame n-1
1633 // x
1634 // --
1635 // ...
1636 //
1637 // --
1638 // x frame 0
1639 // -- <-- stack_base()
1640 //
1641 // (large addresses)
1642 //
1643
1644 private:
1645 // These values are derived from flags StackRedPages, StackYellowPages,
1646 // StackReservedPages and StackShadowPages. The zone size is determined
1647 // ergonomically if page_size > 4K.
1648 static size_t _stack_red_zone_size;
1649 static size_t _stack_yellow_zone_size;
1650 static size_t _stack_reserved_zone_size;
1651 static size_t _stack_shadow_zone_size;
1652 public:
1653 inline size_t stack_available(address cur_sp);
1654
1655 static size_t stack_red_zone_size() {
1656 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1657 return _stack_red_zone_size;
1658 }
1659 static void set_stack_red_zone_size(size_t s) {
1660 assert(is_aligned(s, os::vm_page_size()),
1661 "We can not protect if the red zone size is not page aligned.");
1662 assert(_stack_red_zone_size == 0, "This should be called only once.");
1663 _stack_red_zone_size = s;
1664 }
1665 address stack_red_zone_base() {
1666 return (address)(stack_end() + stack_red_zone_size());
1667 }
1668 bool in_stack_red_zone(address a) {
1669 return a <= stack_red_zone_base() && a >= stack_end();
1670 }
1671
1672 static size_t stack_yellow_zone_size() {
1673 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1674 return _stack_yellow_zone_size;
1675 }
1676 static void set_stack_yellow_zone_size(size_t s) {
1677 assert(is_aligned(s, os::vm_page_size()),
1678 "We can not protect if the yellow zone size is not page aligned.");
1679 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1680 _stack_yellow_zone_size = s;
1681 }
1682
1683 static size_t stack_reserved_zone_size() {
1684 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1685 return _stack_reserved_zone_size;
1686 }
1687 static void set_stack_reserved_zone_size(size_t s) {
1688 assert(is_aligned(s, os::vm_page_size()),
1689 "We can not protect if the reserved zone size is not page aligned.");
1690 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1691 _stack_reserved_zone_size = s;
1692 }
1693 address stack_reserved_zone_base() const {
1694 return (address)(stack_end() +
1695 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1696 }
1697 bool in_stack_reserved_zone(address a) {
1698 return (a <= stack_reserved_zone_base()) &&
1699 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1700 }
1701
1702 static size_t stack_yellow_reserved_zone_size() {
1703 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1704 }
1705 bool in_stack_yellow_reserved_zone(address a) {
1706 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1707 }
1708
1709 // Size of red + yellow + reserved zones.
1710 static size_t stack_guard_zone_size() {
1711 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1712 }
1713
1714 static size_t stack_shadow_zone_size() {
1715 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1716 return _stack_shadow_zone_size;
1717 }
1718 static void set_stack_shadow_zone_size(size_t s) {
1719 // The shadow area is not allocated or protected, so
1720 // it needs not be page aligned.
1721 // But the stack bang currently assumes that it is a
1722 // multiple of page size. This guarantees that the bang
1723 // loop touches all pages in the shadow zone.
1724 // This can be guaranteed differently, as well. E.g., if
1725 // the page size is a multiple of 4K, banging in 4K steps
1726 // suffices to touch all pages. (Some pages are banged
1727 // several times, though.)
1728 assert(is_aligned(s, os::vm_page_size()),
1729 "Stack bang assumes multiple of page size.");
1730 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1731 _stack_shadow_zone_size = s;
1732 }
1733
1734 void create_stack_guard_pages();
1735 void remove_stack_guard_pages();
1736
1737 void enable_stack_reserved_zone();
1738 void disable_stack_reserved_zone();
1739 void enable_stack_yellow_reserved_zone();
1740 void disable_stack_yellow_reserved_zone();
1741 void enable_stack_red_zone();
1742 void disable_stack_red_zone();
1743
1744 inline bool stack_guard_zone_unused();
1745 inline bool stack_yellow_reserved_zone_disabled();
1746 inline bool stack_reserved_zone_disabled();
1747 inline bool stack_guards_enabled();
1748
1749 address reserved_stack_activation() const { return _reserved_stack_activation; }
1750 void set_reserved_stack_activation(address addr) {
1751 assert(_reserved_stack_activation == stack_base()
1752 || _reserved_stack_activation == NULL
1753 || addr == stack_base(), "Must not be set twice");
1754 _reserved_stack_activation = addr;
1755 }
1756
1757 // Attempt to reguard the stack after a stack overflow may have occurred.
1758 // Returns true if (a) guard pages are not needed on this thread, (b) the
1759 // pages are already guarded, or (c) the pages were successfully reguarded.
1760 // Returns false if there is not enough stack space to reguard the pages, in
1761 // which case the caller should unwind a frame and try again. The argument
1762 // should be the caller's (approximate) sp.
1763 bool reguard_stack(address cur_sp);
1764 // Similar to above but see if current stackpoint is out of the guard area
1765 // and reguard if possible.
1766 bool reguard_stack(void);
1767
1768 address stack_overflow_limit() { return _stack_overflow_limit; }
1769 void set_stack_overflow_limit() {
1770 _stack_overflow_limit =
1771 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1772 }
1773
1774 // Check if address is in the usable part of the stack (excludes protected
1775 // guard pages). Can be applied to any thread and is an approximation for
1776 // using is_in_live_stack when the query has to happen from another thread.
1777 bool is_in_usable_stack(address adr) const {
1778 return is_in_stack_range_incl(adr, stack_reserved_zone_base());
1779 }
1780
1781 // Misc. accessors/mutators
1782 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1783 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1784 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1785
1786 // For assembly stub generation
1787 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1788 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1789 static ByteSize pending_jni_exception_check_fn_offset() {
1790 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1791 }
1792 static ByteSize last_Java_sp_offset() {
1793 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1794 }
1795 static ByteSize last_Java_pc_offset() {
1796 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1797 }
1798 static ByteSize frame_anchor_offset() {
1799 return byte_offset_of(JavaThread, _anchor);
1800 }
1801 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1802 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1803 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1804 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1805 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1806 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1807 #if INCLUDE_JVMCI
1808 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1809 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1810 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1811 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1812 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1813 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1814 #endif // INCLUDE_JVMCI
1815 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1816 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1817 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1818 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1819 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1820 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1821 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1822 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1823
1824 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1825 static ByteSize should_post_on_exceptions_flag_offset() {
1826 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1827 }
1828 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1829
1830 // Returns the jni environment for this thread
1831 JNIEnv* jni_environment() { return &_jni_environment; }
1832
1833 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1834 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1835 // Only return NULL if thread is off the thread list; starting to
1836 // exit should not return NULL.
1837 if (thread_from_jni_env->is_terminated()) {
1838 thread_from_jni_env->block_if_vm_exited();
1839 return NULL;
1840 } else {
1841 return thread_from_jni_env;
1842 }
1843 }
1844
1845 // JNI critical regions. These can nest.
1846 bool in_critical() { return _jni_active_critical > 0; }
1847 bool in_last_critical() { return _jni_active_critical == 1; }
1848 inline void enter_critical();
1849 void exit_critical() {
1850 assert(Thread::current() == this, "this must be current thread");
1851 _jni_active_critical--;
1852 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1853 }
1854
1855 // Checked JNI: is the programmer required to check for exceptions, if so specify
1856 // which function name. Returning to a Java frame should implicitly clear the
1857 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1858 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1859 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1860 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1861 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1862 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1863 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1864
1865 // For deadlock detection
1866 int depth_first_number() { return _depth_first_number; }
1867 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1868
1869 private:
1870 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1871
1872 public:
1873 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1874 void add_monitor_chunk(MonitorChunk* chunk);
1875 void remove_monitor_chunk(MonitorChunk* chunk);
1876 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1877 void inc_in_deopt_handler() { _in_deopt_handler++; }
1878 void dec_in_deopt_handler() {
1879 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1880 if (_in_deopt_handler > 0) { // robustness
1881 _in_deopt_handler--;
1882 }
1883 }
1884
1885 private:
1886 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1887
1888 public:
1889
1890 // Frame iteration; calls the function f for all frames on the stack
1891 void frames_do(void f(frame*, const RegisterMap*));
1892
1893 // Memory operations
1894 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1895
1896 // Sweeper operations
1897 virtual void nmethods_do(CodeBlobClosure* cf);
1898
1899 // RedefineClasses Support
1900 void metadata_do(MetadataClosure* f);
1901
1902 // Debug method asserting thread states are correct during a handshake operation.
1903 DEBUG_ONLY(void verify_states_for_handshake();)
1904
1905 // Misc. operations
1906 char* name() const { return (char*)get_thread_name(); }
1907 void print_on(outputStream* st, bool print_extended_info) const;
1908 void print_on(outputStream* st) const { print_on(st, false); }
1909 void print() const;
1910 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1911 void print_on_error(outputStream* st, char* buf, int buflen) const;
1912 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1913 void verify();
1914 const char* get_thread_name() const;
1915 protected:
1916 // factor out low-level mechanics for use in both normal and error cases
1917 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1918 public:
1919 // Accessing frames
1920 frame last_frame() {
1921 _anchor.make_walkable(this);
1922 return pd_last_frame();
1923 }
1924 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1925
1926 // Returns method at 'depth' java or native frames down the stack
1927 // Used for security checks
1928 Klass* security_get_caller_class(int depth);
1929
1930 // Print stack trace in external format
1931 void print_stack_on(outputStream* st);
1932 void print_stack() { print_stack_on(tty); }
1933
1934 // Print stack traces in various internal formats
1935 void trace_stack() PRODUCT_RETURN;
1936 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1937 void trace_frames() PRODUCT_RETURN;
1938
1939 // Print an annotated view of the stack frames
1940 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1941 void validate_frame_layout() {
1942 print_frame_layout(0, true);
1943 }
1944
1945 // Function for testing deoptimization
1946 void deoptimize();
1947 void make_zombies();
1948
1949 void deoptimize_marked_methods();
1950
1951 public:
1952 // Returns the running thread as a JavaThread
1953 static inline JavaThread* current();
1954
1955 // Returns the active Java thread. Do not use this if you know you are calling
1956 // from a JavaThread, as it's slower than JavaThread::current. If called from
1957 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1958 // operation. You may not want that either.
1959 static JavaThread* active();
1960
1961 inline CompilerThread* as_CompilerThread();
1962
1963 protected:
1964 virtual void pre_run();
1965 virtual void run();
1966 void thread_main_inner();
1967 virtual void post_run();
1968
1969
1970 private:
1971 GrowableArray<oop>* _array_for_gc;
1972 public:
1973
1974 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1975
1976 public:
1977 // Thread local information maintained by JVMTI.
1978 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1979 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1980 // getter is used to get this JavaThread's JvmtiThreadState if it has
1981 // one which means NULL can be returned. JvmtiThreadState::state_for()
1982 // is used to get the specified JavaThread's JvmtiThreadState if it has
1983 // one or it allocates a new JvmtiThreadState for the JavaThread and
1984 // returns it. JvmtiThreadState::state_for() will return NULL only if
1985 // the specified JavaThread is exiting.
1986 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1987 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1988
1989 // JVMTI PopFrame support
1990 // Setting and clearing popframe_condition
1991 // All of these enumerated values are bits. popframe_pending
1992 // indicates that a PopFrame() has been requested and not yet been
1993 // completed. popframe_processing indicates that that PopFrame() is in
1994 // the process of being completed. popframe_force_deopt_reexecution_bit
1995 // indicates that special handling is required when returning to a
1996 // deoptimized caller.
1997 enum PopCondition {
1998 popframe_inactive = 0x00,
1999 popframe_pending_bit = 0x01,
2000 popframe_processing_bit = 0x02,
2001 popframe_force_deopt_reexecution_bit = 0x04
2002 };
2003 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
2004 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
2005 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
2006 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
2007 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
2008 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
2009 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
2010 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
2011
2012 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
2013 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
2014 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
2015
2016 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
2017 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
2018 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
2019
2020 private:
2021 // Saved incoming arguments to popped frame.
2022 // Used only when popped interpreted frame returns to deoptimized frame.
2023 void* _popframe_preserved_args;
2024 int _popframe_preserved_args_size;
2025
2026 public:
2027 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2028 void* popframe_preserved_args();
2029 ByteSize popframe_preserved_args_size();
2030 WordSize popframe_preserved_args_size_in_words();
2031 void popframe_free_preserved_args();
2032
2033
2034 private:
2035 JvmtiThreadState *_jvmti_thread_state;
2036
2037 // Used by the interpreter in fullspeed mode for frame pop, method
2038 // entry, method exit and single stepping support. This field is
2039 // only set to non-zero at a safepoint or using a direct handshake
2040 // (see EnterInterpOnlyModeClosure).
2041 // It can be set to zero asynchronously to this threads execution (i.e., without
2042 // safepoint/handshake or a lock) so we have to be very careful.
2043 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
2044 int _interp_only_mode;
2045
2046 public:
2047 // used by the interpreter for fullspeed debugging support (see above)
2048 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2049 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2050 int get_interp_only_mode() { return _interp_only_mode; }
2051 void increment_interp_only_mode() { ++_interp_only_mode; }
2052 void decrement_interp_only_mode() { --_interp_only_mode; }
2053
2054 // support for cached flag that indicates whether exceptions need to be posted for this thread
2055 // if this is false, we can avoid deoptimizing when events are thrown
2056 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2057 private:
2058 int _should_post_on_exceptions_flag;
2059
2060 public:
2061 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2062 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2063
2064 private:
2065 ThreadStatistics *_thread_stat;
2066
2067 public:
2068 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2069
2070 // Return a blocker object for which this thread is blocked parking.
2071 oop current_park_blocker();
2072
2073 private:
2074 static size_t _stack_size_at_create;
2075
2076 public:
2077 static inline size_t stack_size_at_create(void) {
2078 return _stack_size_at_create;
2079 }
2080 static inline void set_stack_size_at_create(size_t value) {
2081 _stack_size_at_create = value;
2082 }
2083
2084 // Machine dependent stuff
2085 #include OS_CPU_HEADER(thread)
2086
2087 // JSR166 per-thread parker
2088 private:
2089 Parker* _parker;
2090 public:
2091 Parker* parker() { return _parker; }
2092
2093 // Biased locking support
2094 private:
2095 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2096 public:
2097 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2098 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2099
2100 // clearing/querying jni attach status
2101 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2102 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2103 inline void set_done_attaching_via_jni();
2104
2105 // Stack dump assistance:
2106 // Track the class we want to initialize but for which we have to wait
2107 // on its init_lock() because it is already being initialized.
2108 void set_class_to_be_initialized(InstanceKlass* k);
2109 InstanceKlass* class_to_be_initialized() const;
2110
2111 private:
2112 InstanceKlass* _class_to_be_initialized;
2113
2114 // java.lang.Thread.sleep support
2115 ParkEvent * _SleepEvent;
2116 public:
2117 bool sleep(jlong millis);
2118
2119 // java.lang.Thread interruption support
2120 void interrupt();
2121 bool is_interrupted(bool clear_interrupted);
2122
2123 };
2124
2125 // Inline implementation of JavaThread::current
2126 inline JavaThread* JavaThread::current() {
2127 Thread* thread = Thread::current();
2128 assert(thread->is_Java_thread(), "just checking");
2129 return (JavaThread*)thread;
2130 }
2131
2132 inline CompilerThread* JavaThread::as_CompilerThread() {
2133 assert(is_Compiler_thread(), "just checking");
2134 return (CompilerThread*)this;
2135 }
2136
2137 // Dedicated thread to sweep the code cache
2138 class CodeCacheSweeperThread : public JavaThread {
2139 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2140 public:
2141 CodeCacheSweeperThread();
2142 // Track the nmethod currently being scanned by the sweeper
2143 void set_scanned_compiled_method(CompiledMethod* cm) {
2144 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2145 _scanned_compiled_method = cm;
2146 }
2147
2148 // Hide sweeper thread from external view.
2149 bool is_hidden_from_external_view() const { return true; }
2150
2151 bool is_Code_cache_sweeper_thread() const { return true; }
2152
2153 // Prevent GC from unloading _scanned_compiled_method
2154 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2155 void nmethods_do(CodeBlobClosure* cf);
2156 };
2157
2158 // A thread used for Compilation.
2159 class CompilerThread : public JavaThread {
2160 friend class VMStructs;
2161 private:
2162 CompilerCounters* _counters;
2163
2164 ciEnv* _env;
2165 CompileLog* _log;
2166 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2167 CompileQueue* _queue;
2168 BufferBlob* _buffer_blob;
2169
2170 AbstractCompiler* _compiler;
2171 TimeStamp _idle_time;
2172
2173 public:
2174
2175 static CompilerThread* current();
2176
2177 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2178 ~CompilerThread();
2179
2180 bool is_Compiler_thread() const { return true; }
2181
2182 virtual bool can_call_java() const;
2183
2184 // Hide native compiler threads from external view.
2185 bool is_hidden_from_external_view() const { return !can_call_java(); }
2186
2187 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2188 AbstractCompiler* compiler() const { return _compiler; }
2189
2190 CompileQueue* queue() const { return _queue; }
2191 CompilerCounters* counters() const { return _counters; }
2192
2193 // Get/set the thread's compilation environment.
2194 ciEnv* env() { return _env; }
2195 void set_env(ciEnv* env) { _env = env; }
2196
2197 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2198 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2199
2200 // Get/set the thread's logging information
2201 CompileLog* log() { return _log; }
2202 void init_log(CompileLog* log) {
2203 // Set once, for good.
2204 assert(_log == NULL, "set only once");
2205 _log = log;
2206 }
2207
2208 void start_idle_timer() { _idle_time.update(); }
2209 jlong idle_time_millis() {
2210 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2211 }
2212
2213 #ifndef PRODUCT
2214 private:
2215 IdealGraphPrinter *_ideal_graph_printer;
2216 public:
2217 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2218 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2219 #endif
2220
2221 // Get/set the thread's current task
2222 CompileTask* task() { return _task; }
2223 void set_task(CompileTask* task) { _task = task; }
2224 };
2225
2226 inline CompilerThread* CompilerThread::current() {
2227 return JavaThread::current()->as_CompilerThread();
2228 }
2229
2230 // The active thread queue. It also keeps track of the current used
2231 // thread priorities.
2232 class Threads: AllStatic {
2233 friend class VMStructs;
2234 private:
2235 static int _number_of_threads;
2236 static int _number_of_non_daemon_threads;
2237 static int _return_code;
2238 static uintx _thread_claim_token;
2239 #ifdef ASSERT
2240 static bool _vm_complete;
2241 #endif
2242
2243 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2244 static void initialize_jsr292_core_classes(TRAPS);
2245
2246 public:
2247 // Thread management
2248 // force_daemon is a concession to JNI, where we may need to add a
2249 // thread to the thread list before allocating its thread object
2250 static void add(JavaThread* p, bool force_daemon = false);
2251 static void remove(JavaThread* p, bool is_daemon);
2252 static void non_java_threads_do(ThreadClosure* tc);
2253 static void java_threads_do(ThreadClosure* tc);
2254 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2255 static void threads_do(ThreadClosure* tc);
2256 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2257
2258 // Initializes the vm and creates the vm thread
2259 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2260 static void convert_vm_init_libraries_to_agents();
2261 static void create_vm_init_libraries();
2262 static void create_vm_init_agents();
2263 static void shutdown_vm_agents();
2264 static bool destroy_vm();
2265 // Supported VM versions via JNI
2266 // Includes JNI_VERSION_1_1
2267 static jboolean is_supported_jni_version_including_1_1(jint version);
2268 // Does not include JNI_VERSION_1_1
2269 static jboolean is_supported_jni_version(jint version);
2270
2271 // The "thread claim token" provides a way for threads to be claimed
2272 // by parallel worker tasks.
2273 //
2274 // Each thread contains a "token" field. A task will claim the
2275 // thread only if its token is different from the global token,
2276 // which is updated by calling change_thread_claim_token(). When
2277 // a thread is claimed, it's token is set to the global token value
2278 // so other threads in the same iteration pass won't claim it.
2279 //
2280 // For this to work change_thread_claim_token() needs to be called
2281 // exactly once in sequential code before starting parallel tasks
2282 // that should claim threads.
2283 //
2284 // New threads get their token set to 0 and change_thread_claim_token()
2285 // never sets the global token to 0.
2286 static uintx thread_claim_token() { return _thread_claim_token; }
2287 static void change_thread_claim_token();
2288 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2289
2290 // Apply "f->do_oop" to all root oops in all threads.
2291 // This version may only be called by sequential code.
2292 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2293 // This version may be called by sequential or parallel code.
2294 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2295
2296 // Sweeper
2297 static void nmethods_do(CodeBlobClosure* cf);
2298
2299 // RedefineClasses support
2300 static void metadata_do(MetadataClosure* f);
2301 static void metadata_handles_do(void f(Metadata*));
2302
2303 #ifdef ASSERT
2304 static bool is_vm_complete() { return _vm_complete; }
2305 #endif // ASSERT
2306
2307 // Verification
2308 static void verify();
2309 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2310 static void print(bool print_stacks, bool internal_format) {
2311 // this function is only used by debug.cpp
2312 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2313 }
2314 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2315 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2316 int buflen, bool* found_current);
2317 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2318
2319 // Get Java threads that are waiting to enter a monitor.
2320 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2321 int count, address monitor);
2322
2323 // Get owning Java thread from the monitor's owner field.
2324 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2325 address owner);
2326
2327 // Number of threads on the active threads list
2328 static int number_of_threads() { return _number_of_threads; }
2329 // Number of non-daemon threads on the active threads list
2330 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2331
2332 // Deoptimizes all frames tied to marked nmethods
2333 static void deoptimized_wrt_marked_nmethods();
2334
2335 struct Test; // For private gtest access.
2336 };
2337
2338 class SignalHandlerMark: public StackObj {
2339 private:
2340 Thread* _thread;
2341 public:
2342 SignalHandlerMark(Thread* t) {
2343 _thread = t;
2344 if (_thread) _thread->enter_signal_handler();
2345 }
2346 ~SignalHandlerMark() {
2347 if (_thread) _thread->leave_signal_handler();
2348 _thread = NULL;
2349 }
2350 };
2351
2352
2353 #endif // SHARE_RUNTIME_THREAD_HPP