1 /*
2 * Copyright (c) 1997, 2019, 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 "code/compiledMethod.hpp"
30 #include "gc/shared/gcThreadLocalData.hpp"
31 #include "gc/shared/threadLocalAllocBuffer.hpp"
32 #include "memory/allocation.hpp"
33 #include "oops/oop.hpp"
34 #include "prims/jvmtiExport.hpp"
35 #include "runtime/frame.hpp"
36 #include "runtime/globals.hpp"
37 #include "runtime/handshake.hpp"
38 #include "runtime/javaFrameAnchor.hpp"
39 #include "runtime/jniHandles.hpp"
40 #include "runtime/mutexLocker.hpp"
41 #include "runtime/os.hpp"
42 #include "runtime/osThread.hpp"
43 #include "runtime/park.hpp"
44 #include "runtime/stubRoutines.hpp"
45 #include "runtime/threadHeapSampler.hpp"
46 #include "runtime/threadLocalStorage.hpp"
47 #include "runtime/threadStatisticalInfo.hpp"
48 #include "runtime/unhandledOops.hpp"
49 #include "utilities/align.hpp"
50 #include "utilities/exceptions.hpp"
51 #include "utilities/macros.hpp"
52 #ifdef ZERO
53 # include "stack_zero.hpp"
54 #endif
55 #if INCLUDE_JFR
56 #include "jfr/support/jfrThreadExtension.hpp"
57 #endif
58
59
60 class SafeThreadsListPtr;
61 class ThreadSafepointState;
62 class ThreadsList;
63 class ThreadsSMRSupport;
64
65 class JvmtiThreadState;
66 class ThreadStatistics;
67 class ConcurrentLocksDump;
68 class ParkEvent;
69 class Parker;
70 class MonitorInfo;
71
72 class ciEnv;
73 class CompileThread;
74 class CompileLog;
75 class CompileTask;
76 class CompileQueue;
77 class CompilerCounters;
78
79 class vframeArray;
80 class vframe;
81 class javaVFrame;
82
83 class DeoptResourceMark;
84 class jvmtiDeferredLocalVariableSet;
85
86 class GCTaskQueue;
87 class ThreadClosure;
88 class ICRefillVerifier;
89 class IdealGraphPrinter;
90
91 class JVMCIEnv;
92 class JVMCIPrimitiveArray;
93
94 class Metadata;
95 class ResourceArea;
96
97 DEBUG_ONLY(class ResourceMark;)
98
99 class WorkerThread;
100
101 // Class hierarchy
102 // - Thread
103 // - JavaThread
104 // - various subclasses eg CompilerThread, ServiceThread
105 // - NonJavaThread
106 // - NamedThread
107 // - VMThread
108 // - ConcurrentGCThread
109 // - WorkerThread
110 // - GangWorker
111 // - GCTaskThread
112 // - WatcherThread
113 // - JfrThreadSampler
114 //
115 // All Thread subclasses must be either JavaThread or NonJavaThread.
116 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
117 // a partially constructed/destroyed Thread.
118
119 // Thread execution sequence and actions:
120 // All threads:
121 // - thread_native_entry // per-OS native entry point
122 // - stack initialization
123 // - other OS-level initialization (signal masks etc)
124 // - handshake with creating thread (if not started suspended)
125 // - this->call_run() // common shared entry point
126 // - shared common initialization
127 // - this->pre_run() // virtual per-thread-type initialization
128 // - this->run() // virtual per-thread-type "main" logic
129 // - shared common tear-down
130 // - this->post_run() // virtual per-thread-type tear-down
131 // - // 'this' no longer referenceable
132 // - OS-level tear-down (minimal)
133 // - final logging
134 //
135 // For JavaThread:
136 // - this->run() // virtual but not normally overridden
137 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
138 // - this->entry_point() // set differently for each kind of JavaThread
139
140 class Thread: public ThreadShadow {
141 friend class VMStructs;
142 friend class JVMCIVMStructs;
143 private:
144
145 #ifndef USE_LIBRARY_BASED_TLS_ONLY
146 // Current thread is maintained as a thread-local variable
147 static THREAD_LOCAL_DECL Thread* _thr_current;
148 #endif
149
150 // Thread local data area available to the GC. The internal
151 // structure and contents of this data area is GC-specific.
152 // Only GC and GC barrier code should access this data area.
153 GCThreadLocalData _gc_data;
154
155 public:
156 static ByteSize gc_data_offset() {
157 return byte_offset_of(Thread, _gc_data);
158 }
159
160 template <typename T> T* gc_data() {
161 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
162 return reinterpret_cast<T*>(&_gc_data);
163 }
164
165 // Exception handling
166 // (Note: _pending_exception and friends are in ThreadShadow)
167 //oop _pending_exception; // pending exception for current thread
168 // const char* _exception_file; // file information for exception (debugging only)
169 // int _exception_line; // line information for exception (debugging only)
170 protected:
171
172 DEBUG_ONLY(static Thread* _starting_thread;)
173
174 // Support for forcing alignment of thread objects for biased locking
175 void* _real_malloc_address;
176
177 // JavaThread lifecycle support:
178 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
179 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
180 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
181 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
182 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
183
184 ThreadsList* volatile _threads_hazard_ptr;
185 SafeThreadsListPtr* _threads_list_ptr;
186 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
187 ThreadsList* get_threads_hazard_ptr();
188 void set_threads_hazard_ptr(ThreadsList* new_list);
189 static bool is_hazard_ptr_tagged(ThreadsList* list) {
190 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
191 }
192 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
193 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
194 }
195 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
196 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
197 }
198 // This field is enabled via -XX:+EnableThreadSMRStatistics:
199 uint _nested_threads_hazard_ptr_cnt;
200 void dec_nested_threads_hazard_ptr_cnt() {
201 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
202 _nested_threads_hazard_ptr_cnt--;
203 }
204 void inc_nested_threads_hazard_ptr_cnt() {
205 _nested_threads_hazard_ptr_cnt++;
206 }
207 uint nested_threads_hazard_ptr_cnt() {
208 return _nested_threads_hazard_ptr_cnt;
209 }
210
211 public:
212 void* operator new(size_t size) throw() { return allocate(size, true); }
213 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
214 return allocate(size, false); }
215 void operator delete(void* p);
216
217 protected:
218 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
219 private:
220
221 // ***************************************************************
222 // Suspend and resume support
223 // ***************************************************************
224 //
225 // VM suspend/resume no longer exists - it was once used for various
226 // things including safepoints but was deprecated and finally removed
227 // in Java 7. Because VM suspension was considered "internal" Java-level
228 // suspension was considered "external", and this legacy naming scheme
229 // remains.
230 //
231 // External suspend/resume requests come from JVM_SuspendThread,
232 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
233 // ResumeThread. External
234 // suspend requests cause _external_suspend to be set and external
235 // resume requests cause _external_suspend to be cleared.
236 // External suspend requests do not nest on top of other external
237 // suspend requests. The higher level APIs reject suspend requests
238 // for already suspended threads.
239 //
240 // The external_suspend
241 // flag is checked by has_special_runtime_exit_condition() and java thread
242 // will self-suspend when handle_special_runtime_exit_condition() is
243 // called. Most uses of the _thread_blocked state in JavaThreads are
244 // considered the same as being externally suspended; if the blocking
245 // condition lifts, the JavaThread will self-suspend. Other places
246 // where VM checks for external_suspend include:
247 // + mutex granting (do not enter monitors when thread is suspended)
248 // + state transitions from _thread_in_native
249 //
250 // In general, java_suspend() does not wait for an external suspend
251 // request to complete. When it returns, the only guarantee is that
252 // the _external_suspend field is true.
253 //
254 // wait_for_ext_suspend_completion() is used to wait for an external
255 // suspend request to complete. External suspend requests are usually
256 // followed by some other interface call that requires the thread to
257 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
258 // the interface that requires quiescence, we give the JavaThread a
259 // chance to self-suspend before we need it to be quiescent. This
260 // improves overall suspend/query performance.
261 //
262 // _suspend_flags controls the behavior of java_ suspend/resume.
263 // It must be set under the protection of SR_lock. Read from the flag is
264 // OK without SR_lock as long as the value is only used as a hint.
265 // (e.g., check _external_suspend first without lock and then recheck
266 // inside SR_lock and finish the suspension)
267 //
268 // _suspend_flags is also overloaded for other "special conditions" so
269 // that a single check indicates whether any special action is needed
270 // eg. for async exceptions.
271 // -------------------------------------------------------------------
272 // Notes:
273 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
274 // but we still update its value to keep other part of the system (mainly
275 // JVMTI) happy. ThreadState is legacy code (see notes in
276 // osThread.hpp).
277 //
278 // 2. It would be more natural if set_external_suspend() is private and
279 // part of java_suspend(), but that probably would affect the suspend/query
280 // performance. Need more investigation on this.
281
282 // suspend/resume lock: used for self-suspend
283 Monitor* _SR_lock;
284
285 protected:
286 enum SuspendFlags {
287 // NOTE: avoid using the sign-bit as cc generates different test code
288 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
289
290 _external_suspend = 0x20000000U, // thread is asked to self suspend
291 _ext_suspended = 0x40000000U, // thread has self-suspended
292 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
293
294 _has_async_exception = 0x00000001U, // there is a pending async exception
295 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
296
297 _trace_flag = 0x00000004U // call tracing backend
298 };
299
300 // various suspension related flags - atomically updated
301 // overloaded for async exception checking in check_special_condition_for_native_trans.
302 volatile uint32_t _suspend_flags;
303
304 private:
305 int _num_nested_signal;
306
307 DEBUG_ONLY(bool _suspendible_thread;)
308
309 public:
310 void enter_signal_handler() { _num_nested_signal++; }
311 void leave_signal_handler() { _num_nested_signal--; }
312 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
313
314 // Determines if a heap allocation failure will be retried
315 // (e.g., by deoptimizing and re-executing in the interpreter).
316 // In this case, the failed allocation must raise
317 // Universe::out_of_memory_error_retry() and omit side effects
318 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
319 // and -XX:OnOutOfMemoryError.
320 virtual bool in_retryable_allocation() const { return false; }
321
322 #ifdef ASSERT
323 void set_suspendible_thread() {
324 _suspendible_thread = true;
325 }
326
327 void clear_suspendible_thread() {
328 _suspendible_thread = false;
329 }
330
331 bool is_suspendible_thread() { return _suspendible_thread; }
332 #endif
333
334 private:
335 // Active_handles points to a block of handles
336 JNIHandleBlock* _active_handles;
337
338 // One-element thread local free list
339 JNIHandleBlock* _free_handle_block;
340
341 // Point to the last handle mark
342 HandleMark* _last_handle_mark;
343
344 // The parity of the last strong_roots iteration in which this thread was
345 // claimed as a task.
346 int _oops_do_parity;
347
348 // Support for GlobalCounter
349 private:
350 volatile uintx _rcu_counter;
351 public:
352 volatile uintx* get_rcu_counter() {
353 return &_rcu_counter;
354 }
355
356 public:
357 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
358 HandleMark* last_handle_mark() const { return _last_handle_mark; }
359 private:
360
361 #ifdef ASSERT
362 ICRefillVerifier* _missed_ic_stub_refill_verifier;
363
364 public:
365 ICRefillVerifier* missed_ic_stub_refill_verifier() {
366 return _missed_ic_stub_refill_verifier;
367 }
368
369 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
370 _missed_ic_stub_refill_verifier = verifier;
371 }
372 #endif
373
374 private:
375
376 // debug support for checking if code does allow safepoints or not
377 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
378 // mutex, or blocking on an object synchronizer (Java locking).
379 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
380 // If !allow_allocation(), then an assertion failure will happen during allocation
381 // (Hence, !allow_safepoint() => !allow_allocation()).
382 //
383 // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
384 //
385 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
386 debug_only(int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
387
388 // Used by SkipGCALot class.
389 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
390
391 friend class NoAllocVerifier;
392 friend class NoSafepointVerifier;
393 friend class PauseNoSafepointVerifier;
394 friend class GCLocker;
395
396 volatile void* _polling_page; // Thread local polling page
397
398 ThreadLocalAllocBuffer _tlab; // Thread-local eden
399 jlong _allocated_bytes; // Cumulative number of bytes allocated on
400 // the Java heap
401 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
402
403 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
404
405 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
406
407 int _vm_operation_started_count; // VM_Operation support
408 int _vm_operation_completed_count; // VM_Operation support
409
410 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
411 // is waiting to lock
412 bool _current_pending_monitor_is_from_java; // locking is from Java code
413
414 // ObjectMonitor on which this thread called Object.wait()
415 ObjectMonitor* _current_waiting_monitor;
416
417 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
418 public:
419 ObjectMonitor* omFreeList;
420 int omFreeCount; // length of omFreeList
421 int omFreeProvision; // reload chunk size
422 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
423 int omInUseCount; // length of omInUseList
424
425 #ifdef ASSERT
426 private:
427 volatile uint64_t _visited_for_critical_count;
428
429 public:
430 void set_visited_for_critical_count(uint64_t safepoint_id) {
431 assert(_visited_for_critical_count == 0, "Must be reset before set");
432 assert((safepoint_id & 0x1) == 1, "Must be odd");
433 _visited_for_critical_count = safepoint_id;
434 }
435 void reset_visited_for_critical_count(uint64_t safepoint_id) {
436 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
437 _visited_for_critical_count = 0;
438 }
439 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
440 return _visited_for_critical_count == safepoint_id;
441 }
442 #endif
443
444 public:
445 enum {
446 is_definitely_current_thread = true
447 };
448
449 // Constructor
450 Thread();
451 virtual ~Thread() = 0; // Thread is abstract.
452
453 // Manage Thread::current()
454 void initialize_thread_current();
455 static void clear_thread_current(); // TLS cleanup needed before threads terminate
456
457 protected:
458 // To be implemented by children.
459 virtual void run() = 0;
460 virtual void pre_run() = 0;
461 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
462
463 #ifdef ASSERT
464 enum RunState {
465 PRE_CALL_RUN,
466 CALL_RUN,
467 PRE_RUN,
468 RUN,
469 POST_RUN
470 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
471 };
472 RunState _run_state; // for lifecycle checks
473 #endif
474
475
476 public:
477 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
478 void call_run();
479
480 // Testers
481 virtual bool is_VM_thread() const { return false; }
482 virtual bool is_Java_thread() const { return false; }
483 virtual bool is_Compiler_thread() const { return false; }
484 virtual bool is_Code_cache_sweeper_thread() const { return false; }
485 virtual bool is_hidden_from_external_view() const { return false; }
486 virtual bool is_jvmti_agent_thread() const { return false; }
487 // True iff the thread can perform GC operations at a safepoint.
488 // Generally will be true only of VM thread and parallel GC WorkGang
489 // threads.
490 virtual bool is_GC_task_thread() const { return false; }
491 virtual bool is_Watcher_thread() const { return false; }
492 virtual bool is_ConcurrentGC_thread() const { return false; }
493 virtual bool is_Named_thread() const { return false; }
494 virtual bool is_Worker_thread() const { return false; }
495
496 // Can this thread make Java upcalls
497 virtual bool can_call_java() const { return false; }
498
499 // Casts
500 virtual WorkerThread* as_Worker_thread() const { return NULL; }
501
502 virtual char* name() const { return (char*)"Unknown thread"; }
503
504 // Returns the current thread (ASSERTS if NULL)
505 static inline Thread* current();
506 // Returns the current thread, or NULL if not attached
507 static inline Thread* current_or_null();
508 // Returns the current thread, or NULL if not attached, and is
509 // safe for use from signal-handlers
510 static inline Thread* current_or_null_safe();
511
512 // Common thread operations
513 #ifdef ASSERT
514 static void check_for_dangling_thread_pointer(Thread *thread);
515 #endif
516 static void set_priority(Thread* thread, ThreadPriority priority);
517 static ThreadPriority get_priority(const Thread* const thread);
518 static void start(Thread* thread);
519 static void interrupt(Thread* thr);
520 static bool is_interrupted(Thread* thr, bool clear_interrupted);
521
522 void set_native_thread_name(const char *name) {
523 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
524 os::set_native_thread_name(name);
525 }
526
527 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
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 // Support for Unhandled Oop detection
547 // Add the field for both, fastdebug and debug, builds to keep
548 // Thread's fields layout the same.
549 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
550 #ifdef CHECK_UNHANDLED_OOPS
551 private:
552 UnhandledOops* _unhandled_oops;
553 #elif defined(ASSERT)
554 private:
555 void* _unhandled_oops;
556 #endif
557 #ifdef CHECK_UNHANDLED_OOPS
558 public:
559 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
560 // Mark oop safe for gc. It may be stack allocated but won't move.
561 void allow_unhandled_oop(oop *op) {
562 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
563 }
564 // Clear oops at safepoint so crashes point to unhandled oop violator
565 void clear_unhandled_oops() {
566 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
567 }
568 #endif // CHECK_UNHANDLED_OOPS
569
570 public:
571 #ifndef PRODUCT
572 bool skip_gcalot() { return _skip_gcalot; }
573 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
574 #endif
575
576 // Installs a pending exception to be inserted later
577 static void send_async_exception(oop thread_oop, oop java_throwable);
578
579 // Resource area
580 ResourceArea* resource_area() const { return _resource_area; }
581 void set_resource_area(ResourceArea* area) { _resource_area = area; }
582
583 OSThread* osthread() const { return _osthread; }
584 void set_osthread(OSThread* thread) { _osthread = thread; }
585
586 // JNI handle support
587 JNIHandleBlock* active_handles() const { return _active_handles; }
588 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
589 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
590 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
591
592 // Internal handle support
593 HandleArea* handle_area() const { return _handle_area; }
594 void set_handle_area(HandleArea* area) { _handle_area = area; }
595
596 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
597 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
598
599 // Thread-Local Allocation Buffer (TLAB) support
600 ThreadLocalAllocBuffer& tlab() { return _tlab; }
601 void initialize_tlab() {
602 if (UseTLAB) {
603 tlab().initialize();
604 }
605 }
606
607 jlong allocated_bytes() { return _allocated_bytes; }
608 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
609 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
610 inline jlong cooked_allocated_bytes();
611
612 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
613
614 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
615
616 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
617
618 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
619
620 // VM operation support
621 int vm_operation_ticket() { return ++_vm_operation_started_count; }
622 int vm_operation_completed_count() { return _vm_operation_completed_count; }
623 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
624
625 // For tracking the heavyweight monitor the thread is pending on.
626 ObjectMonitor* current_pending_monitor() {
627 return _current_pending_monitor;
628 }
629 void set_current_pending_monitor(ObjectMonitor* monitor) {
630 _current_pending_monitor = monitor;
631 }
632 void set_current_pending_monitor_is_from_java(bool from_java) {
633 _current_pending_monitor_is_from_java = from_java;
634 }
635 bool current_pending_monitor_is_from_java() {
636 return _current_pending_monitor_is_from_java;
637 }
638
639 // For tracking the ObjectMonitor on which this thread called Object.wait()
640 ObjectMonitor* current_waiting_monitor() {
641 return _current_waiting_monitor;
642 }
643 void set_current_waiting_monitor(ObjectMonitor* monitor) {
644 _current_waiting_monitor = monitor;
645 }
646
647 // GC support
648 // Apply "f->do_oop" to all root oops in "this".
649 // Used by JavaThread::oops_do.
650 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
651 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
652
653 // Handles the parallel case for the method below.
654 private:
655 bool claim_oops_do_par_case(int collection_parity);
656 public:
657 // Requires that "collection_parity" is that of the current roots
658 // iteration. If "is_par" is false, sets the parity of "this" to
659 // "collection_parity", and returns "true". If "is_par" is true,
660 // uses an atomic instruction to set the current threads parity to
661 // "collection_parity", if it is not already. Returns "true" iff the
662 // calling thread does the update, this indicates that the calling thread
663 // has claimed the thread's stack as a root group in the current
664 // collection.
665 bool claim_oops_do(bool is_par, int collection_parity) {
666 if (!is_par) {
667 _oops_do_parity = collection_parity;
668 return true;
669 } else {
670 return claim_oops_do_par_case(collection_parity);
671 }
672 }
673
674 // jvmtiRedefineClasses support
675 void metadata_handles_do(void f(Metadata*));
676
677 // Used by fast lock support
678 virtual bool is_lock_owned(address adr) const;
679
680 // Check if address is in the stack of the thread (not just for locks).
681 // Warning: the method can only be used on the running thread
682 bool is_in_stack(address adr) const;
683 // Check if address is in the usable part of the stack (excludes protected
684 // guard pages)
685 bool is_in_usable_stack(address adr) const;
686
687 // Sets this thread as starting thread. Returns failure if thread
688 // creation fails due to lack of memory, too many threads etc.
689 bool set_as_starting_thread();
690
691 protected:
692 // OS data associated with the thread
693 OSThread* _osthread; // Platform-specific thread information
694
695 // Thread local resource area for temporary allocation within the VM
696 ResourceArea* _resource_area;
697
698 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
699
700 // Thread local handle area for allocation of handles within the VM
701 HandleArea* _handle_area;
702 GrowableArray<Metadata*>* _metadata_handles;
703
704 // Support for stack overflow handling, get_thread, etc.
705 address _stack_base;
706 size_t _stack_size;
707 uintptr_t _self_raw_id; // used by get_thread (mutable)
708 int _lgrp_id;
709
710 volatile void** polling_page_addr() { return &_polling_page; }
711
712 public:
713 // Stack overflow support
714 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
715 void set_stack_base(address base) { _stack_base = base; }
716 size_t stack_size() const { return _stack_size; }
717 void set_stack_size(size_t size) { _stack_size = size; }
718 address stack_end() const { return stack_base() - stack_size(); }
719 void record_stack_base_and_size();
720 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
721
722 bool on_local_stack(address adr) const {
723 // QQQ this has knowledge of direction, ought to be a stack method
724 return (_stack_base >= adr && adr >= stack_end());
725 }
726
727 uintptr_t self_raw_id() { return _self_raw_id; }
728 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
729
730 int lgrp_id() const { return _lgrp_id; }
731 void set_lgrp_id(int value) { _lgrp_id = value; }
732
733 // Printing
734 void print_on(outputStream* st, bool print_extended_info) const;
735 virtual void print_on(outputStream* st) const { print_on(st, false); }
736 void print() const { print_on(tty); }
737 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
738 void print_value_on(outputStream* st) const;
739
740 // Debug-only code
741 #ifdef ASSERT
742 private:
743 // Deadlock detection support for Mutex locks. List of locks own by thread.
744 Monitor* _owned_locks;
745 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
746 // thus the friendship
747 friend class Mutex;
748 friend class Monitor;
749
750 public:
751 void print_owned_locks_on(outputStream* st) const;
752 void print_owned_locks() const { print_owned_locks_on(tty); }
753 Monitor* owned_locks() const { return _owned_locks; }
754 bool owns_locks() const { return owned_locks() != NULL; }
755 bool owns_locks_but_compiled_lock() const;
756 int oops_do_parity() const { return _oops_do_parity; }
757
758 // Deadlock detection
759 bool allow_allocation() { return _allow_allocation_count == 0; }
760 ResourceMark* current_resource_mark() { return _current_resource_mark; }
761 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
762 #endif
763
764 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
765
766 private:
767 volatile int _jvmti_env_iteration_count;
768
769 public:
770 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
771 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
772 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
773
774 // Code generation
775 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
776 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
777 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
778
779 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
780 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
781
782 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
783
784 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
785 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
786 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
787 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
788
789 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
790
791 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
792
793 public:
794 volatile intptr_t _Stalled;
795 volatile int _TypeTag;
796 ParkEvent * _ParkEvent; // for synchronized()
797 ParkEvent * _SleepEvent; // for Thread.sleep
798 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
799 int NativeSyncRecursion; // diagnostic
800
801 volatile int _OnTrap; // Resume-at IP delta
802 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
803 jint _hashStateX; // thread-specific hashCode generator state
804 jint _hashStateY;
805 jint _hashStateZ;
806
807 // Low-level leaf-lock primitives used to implement synchronization
808 // and native monitor-mutex infrastructure.
809 // Not for general synchronization use.
810 static void SpinAcquire(volatile int * Lock, const char * Name);
811 static void SpinRelease(volatile int * Lock);
812 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
813 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
814 static void muxRelease(volatile intptr_t * Lock);
815 };
816
817 // Inline implementation of Thread::current()
818 inline Thread* Thread::current() {
819 Thread* current = current_or_null();
820 assert(current != NULL, "Thread::current() called on detached thread");
821 return current;
822 }
823
824 inline Thread* Thread::current_or_null() {
825 #ifndef USE_LIBRARY_BASED_TLS_ONLY
826 return _thr_current;
827 #else
828 if (ThreadLocalStorage::is_initialized()) {
829 return ThreadLocalStorage::thread();
830 }
831 return NULL;
832 #endif
833 }
834
835 inline Thread* Thread::current_or_null_safe() {
836 if (ThreadLocalStorage::is_initialized()) {
837 return ThreadLocalStorage::thread();
838 }
839 return NULL;
840 }
841
842 class NonJavaThread: public Thread {
843 friend class VMStructs;
844
845 NonJavaThread* volatile _next;
846
847 class List;
848 static List _the_list;
849
850 void add_to_the_list();
851 void remove_from_the_list();
852
853 protected:
854 virtual void pre_run();
855 virtual void post_run();
856
857 public:
858 NonJavaThread();
859 ~NonJavaThread();
860
861 class Iterator;
862 };
863
864 // Provides iteration over the list of NonJavaThreads.
865 // List addition occurs in pre_run(), and removal occurs in post_run(),
866 // so that only live fully-initialized threads can be found in the list.
867 // Threads created after an iterator is constructed will not be visited
868 // by the iterator. The scope of an iterator is a critical section; there
869 // must be no safepoint checks in that scope.
870 class NonJavaThread::Iterator : public StackObj {
871 uint _protect_enter;
872 NonJavaThread* _current;
873
874 // Noncopyable.
875 Iterator(const Iterator&);
876 Iterator& operator=(const Iterator&);
877
878 public:
879 Iterator();
880 ~Iterator();
881
882 bool end() const { return _current == NULL; }
883 NonJavaThread* current() const { return _current; }
884 void step();
885 };
886
887 // Name support for threads. non-JavaThread subclasses with multiple
888 // uniquely named instances should derive from this.
889 class NamedThread: public NonJavaThread {
890 friend class VMStructs;
891 enum {
892 max_name_len = 64
893 };
894 private:
895 char* _name;
896 // log JavaThread being processed by oops_do
897 JavaThread* _processed_thread;
898 uint _gc_id; // The current GC id when a thread takes part in GC
899
900 public:
901 NamedThread();
902 ~NamedThread();
903 // May only be called once per thread.
904 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
905 virtual bool is_Named_thread() const { return true; }
906 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
907 JavaThread *processed_thread() { return _processed_thread; }
908 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
909 virtual void print_on(outputStream* st) const;
910
911 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
912 uint gc_id() { return _gc_id; }
913 };
914
915 // Worker threads are named and have an id of an assigned work.
916 class WorkerThread: public NamedThread {
917 private:
918 uint _id;
919 public:
920 WorkerThread() : _id(0) { }
921 virtual bool is_Worker_thread() const { return true; }
922
923 virtual WorkerThread* as_Worker_thread() const {
924 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
925 return (WorkerThread*) this;
926 }
927
928 void set_id(uint work_id) { _id = work_id; }
929 uint id() const { return _id; }
930 };
931
932 // A single WatcherThread is used for simulating timer interrupts.
933 class WatcherThread: public NonJavaThread {
934 friend class VMStructs;
935 protected:
936 virtual void run();
937
938 private:
939 static WatcherThread* _watcher_thread;
940
941 static bool _startable;
942 // volatile due to at least one lock-free read
943 volatile static bool _should_terminate;
944 public:
945 enum SomeConstants {
946 delay_interval = 10 // interrupt delay in milliseconds
947 };
948
949 // Constructor
950 WatcherThread();
951
952 // No destruction allowed
953 ~WatcherThread() {
954 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
955 }
956
957 // Tester
958 bool is_Watcher_thread() const { return true; }
959
960 // Printing
961 char* name() const { return (char*)"VM Periodic Task Thread"; }
962 void print_on(outputStream* st) const;
963 void unpark();
964
965 // Returns the single instance of WatcherThread
966 static WatcherThread* watcher_thread() { return _watcher_thread; }
967
968 // Create and start the single instance of WatcherThread, or stop it on shutdown
969 static void start();
970 static void stop();
971 // Only allow start once the VM is sufficiently initialized
972 // Otherwise the first task to enroll will trigger the start
973 static void make_startable();
974 private:
975 int sleep() const;
976 };
977
978
979 class CompilerThread;
980
981 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
982
983 class JavaThread: public Thread {
984 friend class VMStructs;
985 friend class JVMCIVMStructs;
986 friend class WhiteBox;
987 private:
988 JavaThread* _next; // The next thread in the Threads list
989 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
990 oop _threadObj; // The Java level thread object
991
992 #ifdef ASSERT
993 private:
994 int _java_call_counter;
995
996 public:
997 int java_call_counter() { return _java_call_counter; }
998 void inc_java_call_counter() { _java_call_counter++; }
999 void dec_java_call_counter() {
1000 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1001 _java_call_counter--;
1002 }
1003 private: // restore original namespace restriction
1004 #endif // ifdef ASSERT
1005
1006 #ifndef PRODUCT
1007 public:
1008 enum {
1009 jump_ring_buffer_size = 16
1010 };
1011 private: // restore original namespace restriction
1012 #endif
1013
1014 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1015
1016 ThreadFunction _entry_point;
1017
1018 JNIEnv _jni_environment;
1019
1020 // Deopt support
1021 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1022
1023 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
1024 // transition out of native
1025 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1026 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1027 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1028 // Because deoptimization is lazy we must save jvmti requests to set locals
1029 // in compiled frames until we deoptimize and we have an interpreter frame.
1030 // This holds the pointer to array (yeah like there might be more than one) of
1031 // description of compiled vframes that have locals that need to be updated.
1032 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1033
1034 // Handshake value for fixing 6243940. We need a place for the i2c
1035 // adapter to store the callee Method*. This value is NEVER live
1036 // across a gc point so it does NOT have to be gc'd
1037 // The handshake is open ended since we can't be certain that it will
1038 // be NULLed. This is because we rarely ever see the race and end up
1039 // in handle_wrong_method which is the backend of the handshake. See
1040 // code in i2c adapters and handle_wrong_method.
1041
1042 Method* _callee_target;
1043
1044 // Used to pass back results to the interpreter or generated code running Java code.
1045 oop _vm_result; // oop result is GC-preserved
1046 Metadata* _vm_result_2; // non-oop result
1047
1048 // See ReduceInitialCardMarks: this holds the precise space interval of
1049 // the most recent slow path allocation for which compiled code has
1050 // elided card-marks for performance along the fast-path.
1051 MemRegion _deferred_card_mark;
1052
1053 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1054 // allocated during deoptimization
1055 // and by JNI_MonitorEnter/Exit
1056
1057 // Async. requests support
1058 enum AsyncRequests {
1059 _no_async_condition = 0,
1060 _async_exception,
1061 _async_unsafe_access_error
1062 };
1063 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1064 oop _pending_async_exception;
1065
1066 // Safepoint support
1067 public: // Expose _thread_state for SafeFetchInt()
1068 volatile JavaThreadState _thread_state;
1069 private:
1070 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1071 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1072
1073 // JavaThread termination support
1074 enum TerminatedTypes {
1075 _not_terminated = 0xDEAD - 2,
1076 _thread_exiting, // JavaThread::exit() has been called for this thread
1077 _thread_terminated, // JavaThread is removed from thread list
1078 _vm_exited // JavaThread is still executing native code, but VM is terminated
1079 // only VM_Exit can set _vm_exited
1080 };
1081
1082 // In general a JavaThread's _terminated field transitions as follows:
1083 //
1084 // _not_terminated => _thread_exiting => _thread_terminated
1085 //
1086 // _vm_exited is a special value to cover the case of a JavaThread
1087 // executing native code after the VM itself is terminated.
1088 volatile TerminatedTypes _terminated;
1089 // suspend/resume support
1090 volatile bool _suspend_equivalent; // Suspend equivalent condition
1091 jint _in_deopt_handler; // count of deoptimization
1092 // handlers thread is in
1093 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1094 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1095 // never locked) when throwing an exception. Used by interpreter only.
1096
1097 // JNI attach states:
1098 enum JNIAttachStates {
1099 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1100 _attaching_via_jni, // thread is attaching via JNI
1101 _attached_via_jni // thread has attached via JNI
1102 };
1103
1104 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1105 // A native thread that is attaching via JNI starts with a value
1106 // of _attaching_via_jni and transitions to _attached_via_jni.
1107 volatile JNIAttachStates _jni_attach_state;
1108
1109 public:
1110 // State of the stack guard pages for this thread.
1111 enum StackGuardState {
1112 stack_guard_unused, // not needed
1113 stack_guard_reserved_disabled,
1114 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1115 stack_guard_enabled // enabled
1116 };
1117
1118 private:
1119
1120 #if INCLUDE_JVMCI
1121 // The _pending_* fields below are used to communicate extra information
1122 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1123
1124 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1125 int _pending_deoptimization;
1126
1127 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1128 // before the monitor has been acquired.
1129 bool _pending_monitorenter;
1130
1131 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1132 bool _pending_transfer_to_interpreter;
1133
1134 // Guard for re-entrant call to JVMCI::adjust_comp_level
1135 bool _adjusting_comp_level;
1136
1137 // True if in a runtime call from compiled code that will deoptimize
1138 // and re-execute a failed heap allocation in the interpreter.
1139 bool _in_retryable_allocation;
1140
1141 // An id of a speculation that JVMCI compiled code can use to further describe and
1142 // uniquely identify the speculative optimization guarded by the uncommon trap
1143 jlong _pending_failed_speculation;
1144
1145 // These fields are mutually exclusive in terms of live ranges.
1146 union {
1147 // Communicates the pc at which the most recent implicit exception occurred
1148 // from the signal handler to a deoptimization stub.
1149 address _implicit_exception_pc;
1150
1151 // Communicates an alternative call target to an i2c stub from a JavaCall .
1152 address _alternate_call_target;
1153 } _jvmci;
1154
1155 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1156 jlong* _jvmci_counters;
1157
1158 public:
1159 static jlong* _jvmci_old_thread_counters;
1160 static void collect_counters(JVMCIEnv* JVMCIENV, JVMCIPrimitiveArray array);
1161 private:
1162 #endif // INCLUDE_JVMCI
1163
1164 StackGuardState _stack_guard_state;
1165
1166 // Precompute the limit of the stack as used in stack overflow checks.
1167 // We load it from here to simplify the stack overflow check in assembly.
1168 address _stack_overflow_limit;
1169 address _reserved_stack_activation;
1170
1171 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1172 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1173 // code)
1174 volatile oop _exception_oop; // Exception thrown in compiled code
1175 volatile address _exception_pc; // PC where exception happened
1176 volatile address _exception_handler_pc; // PC for handler of exception
1177 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1178
1179 private:
1180 // support for JNI critical regions
1181 jint _jni_active_critical; // count of entries into JNI critical region
1182
1183 // Checked JNI: function name requires exception check
1184 char* _pending_jni_exception_check_fn;
1185
1186 // For deadlock detection.
1187 int _depth_first_number;
1188
1189 // JVMTI PopFrame support
1190 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1191 int _popframe_condition;
1192
1193 // If reallocation of scalar replaced objects fails, we throw OOM
1194 // and during exception propagation, pop the top
1195 // _frames_to_pop_failed_realloc frames, the ones that reference
1196 // failed reallocations.
1197 int _frames_to_pop_failed_realloc;
1198
1199 #ifndef PRODUCT
1200 int _jmp_ring_index;
1201 struct {
1202 // We use intptr_t instead of address so debugger doesn't try and display strings
1203 intptr_t _target;
1204 intptr_t _instruction;
1205 const char* _file;
1206 int _line;
1207 } _jmp_ring[jump_ring_buffer_size];
1208 #endif // PRODUCT
1209
1210 friend class VMThread;
1211 friend class ThreadWaitTransition;
1212 friend class VM_Exit;
1213
1214 void initialize(); // Initialized the instance variables
1215
1216 public:
1217 // Constructor
1218 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1219 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1220 ~JavaThread();
1221
1222 #ifdef ASSERT
1223 // verify this JavaThread hasn't be published in the Threads::list yet
1224 void verify_not_published();
1225 #endif
1226
1227 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1228 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1229 _jni_environment.functions = functionTable;
1230 }
1231 struct JNINativeInterface_* get_jni_functions() {
1232 return (struct JNINativeInterface_ *)_jni_environment.functions;
1233 }
1234
1235 // This function is called at thread creation to allow
1236 // platform specific thread variables to be initialized.
1237 void cache_global_variables();
1238
1239 // Executes Shutdown.shutdown()
1240 void invoke_shutdown_hooks();
1241
1242 // Cleanup on thread exit
1243 enum ExitType {
1244 normal_exit,
1245 jni_detach
1246 };
1247 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1248
1249 void cleanup_failed_attach_current_thread();
1250
1251 // Testers
1252 virtual bool is_Java_thread() const { return true; }
1253 virtual bool can_call_java() const { return true; }
1254
1255 // Thread chain operations
1256 JavaThread* next() const { return _next; }
1257 void set_next(JavaThread* p) { _next = p; }
1258
1259 // Thread oop. threadObj() can be NULL for initial JavaThread
1260 // (or for threads attached via JNI)
1261 oop threadObj() const { return _threadObj; }
1262 void set_threadObj(oop p) { _threadObj = p; }
1263
1264 ThreadPriority java_priority() const; // Read from threadObj()
1265
1266 // Prepare thread and add to priority queue. If a priority is
1267 // not specified, use the priority of the thread object. Threads_lock
1268 // must be held while this function is called.
1269 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1270
1271 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1272 address saved_exception_pc() { return _saved_exception_pc; }
1273
1274
1275 ThreadFunction entry_point() const { return _entry_point; }
1276
1277 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1278 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1279
1280 // Last frame anchor routines
1281
1282 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1283
1284 // last_Java_sp
1285 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1286 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1287
1288 // last_Java_pc
1289
1290 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1291
1292 // Safepoint support
1293 inline JavaThreadState thread_state() const;
1294 inline void set_thread_state(JavaThreadState s);
1295 inline ThreadSafepointState* safepoint_state() const;
1296 inline void set_safepoint_state(ThreadSafepointState* state);
1297 inline bool is_at_poll_safepoint();
1298
1299 // JavaThread termination and lifecycle support:
1300 void smr_delete();
1301 bool on_thread_list() const { return _on_thread_list; }
1302 void set_on_thread_list() { _on_thread_list = true; }
1303
1304 // thread has called JavaThread::exit() or is terminated
1305 bool is_exiting() const;
1306 // thread is terminated (no longer on the threads list); we compare
1307 // against the two non-terminated values so that a freed JavaThread
1308 // will also be considered terminated.
1309 bool check_is_terminated(TerminatedTypes l_terminated) const {
1310 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1311 }
1312 bool is_terminated() const;
1313 void set_terminated(TerminatedTypes t);
1314 // special for Threads::remove() which is static:
1315 void set_terminated_value();
1316 void block_if_vm_exited();
1317
1318 bool doing_unsafe_access() { return _doing_unsafe_access; }
1319 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1320
1321 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1322 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1323
1324 inline void set_polling_page_release(void* poll_value);
1325 inline void set_polling_page(void* poll_value);
1326 inline volatile void* get_polling_page();
1327
1328 private:
1329 // Support for thread handshake operations
1330 HandshakeState _handshake;
1331 public:
1332 void set_handshake_operation(HandshakeOperation* op) {
1333 _handshake.set_operation(this, op);
1334 }
1335
1336 bool has_handshake() const {
1337 return _handshake.has_operation();
1338 }
1339
1340 void handshake_process_by_self() {
1341 _handshake.process_by_self(this);
1342 }
1343
1344 void handshake_process_by_vmthread() {
1345 _handshake.process_by_vmthread(this);
1346 }
1347
1348 // Suspend/resume support for JavaThread
1349 private:
1350 inline void set_ext_suspended();
1351 inline void clear_ext_suspended();
1352
1353 public:
1354 void java_suspend(); // higher-level suspension logic called by the public APIs
1355 void java_resume(); // higher-level resume logic called by the public APIs
1356 int java_suspend_self(); // low-level self-suspension mechanics
1357
1358 private:
1359 // mid-level wrapper around java_suspend_self to set up correct state and
1360 // check for a pending safepoint at the end
1361 void java_suspend_self_with_safepoint_check();
1362
1363 public:
1364 void check_and_wait_while_suspended() {
1365 assert(JavaThread::current() == this, "sanity check");
1366
1367 bool do_self_suspend;
1368 do {
1369 // were we externally suspended while we were waiting?
1370 do_self_suspend = handle_special_suspend_equivalent_condition();
1371 if (do_self_suspend) {
1372 // don't surprise the thread that suspended us by returning
1373 java_suspend_self();
1374 set_suspend_equivalent();
1375 }
1376 } while (do_self_suspend);
1377 }
1378 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1379 // Check for async exception in addition to safepoint and suspend request.
1380 static void check_special_condition_for_native_trans(JavaThread *thread);
1381
1382 // Same as check_special_condition_for_native_trans but finishes the
1383 // transition into thread_in_Java mode so that it can potentially
1384 // block.
1385 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1386
1387 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1388 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1389 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1390 // Warning: is_ext_suspend_completed() may temporarily drop the
1391 // SR_lock to allow the thread to reach a stable thread state if
1392 // it is currently in a transient thread state.
1393 return is_ext_suspend_completed(false /* !called_by_wait */,
1394 SuspendRetryDelay, bits);
1395 }
1396
1397 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1398 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1399 // passed as the count and delay parameters. Experiments with specific
1400 // calls to wait_for_ext_suspend_completion() can be done by passing
1401 // other values in the code. Experiments with all calls can be done
1402 // via the appropriate -XX options.
1403 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1404
1405 // test for suspend - most (all?) of these should go away
1406 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1407
1408 inline void set_external_suspend();
1409 inline void clear_external_suspend();
1410
1411 inline void set_deopt_suspend();
1412 inline void clear_deopt_suspend();
1413 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1414
1415 bool is_external_suspend() const {
1416 return (_suspend_flags & _external_suspend) != 0;
1417 }
1418 // Whenever a thread transitions from native to vm/java it must suspend
1419 // if external|deopt suspend is present.
1420 bool is_suspend_after_native() const {
1421 return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1422 }
1423
1424 // external suspend request is completed
1425 bool is_ext_suspended() const {
1426 return (_suspend_flags & _ext_suspended) != 0;
1427 }
1428
1429 bool is_external_suspend_with_lock() const {
1430 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1431 return is_external_suspend();
1432 }
1433
1434 // Special method to handle a pending external suspend request
1435 // when a suspend equivalent condition lifts.
1436 bool handle_special_suspend_equivalent_condition() {
1437 assert(is_suspend_equivalent(),
1438 "should only be called in a suspend equivalence condition");
1439 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1440 bool ret = is_external_suspend();
1441 if (!ret) {
1442 // not about to self-suspend so clear suspend equivalence
1443 clear_suspend_equivalent();
1444 }
1445 // implied else:
1446 // We have a pending external suspend request so we leave the
1447 // suspend_equivalent flag set until java_suspend_self() sets
1448 // the ext_suspended flag and clears the suspend_equivalent
1449 // flag. This insures that wait_for_ext_suspend_completion()
1450 // will return consistent values.
1451 return ret;
1452 }
1453
1454 // utility methods to see if we are doing some kind of suspension
1455 bool is_being_ext_suspended() const {
1456 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1457 return is_ext_suspended() || is_external_suspend();
1458 }
1459
1460 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1461
1462 void set_suspend_equivalent() { _suspend_equivalent = true; }
1463 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1464
1465 // Thread.stop support
1466 void send_thread_stop(oop throwable);
1467 AsyncRequests clear_special_runtime_exit_condition() {
1468 AsyncRequests x = _special_runtime_exit_condition;
1469 _special_runtime_exit_condition = _no_async_condition;
1470 return x;
1471 }
1472
1473 // Are any async conditions present?
1474 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1475
1476 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1477
1478 // these next two are also used for self-suspension and async exception support
1479 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1480
1481 // Return true if JavaThread has an asynchronous condition or
1482 // if external suspension is requested.
1483 bool has_special_runtime_exit_condition() {
1484 // Because we don't use is_external_suspend_with_lock
1485 // it is possible that we won't see an asynchronous external suspend
1486 // request that has just gotten started, i.e., SR_lock grabbed but
1487 // _external_suspend field change either not made yet or not visible
1488 // yet. However, this is okay because the request is asynchronous and
1489 // we will see the new flag value the next time through. It's also
1490 // possible that the external suspend request is dropped after
1491 // we have checked is_external_suspend(), we will recheck its value
1492 // under SR_lock in java_suspend_self().
1493 return (_special_runtime_exit_condition != _no_async_condition) ||
1494 is_external_suspend() || is_trace_suspend();
1495 }
1496
1497 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1498
1499 inline void set_pending_async_exception(oop e);
1500
1501 // Fast-locking support
1502 bool is_lock_owned(address adr) const;
1503
1504 // Accessors for vframe array top
1505 // The linked list of vframe arrays are sorted on sp. This means when we
1506 // unpack the head must contain the vframe array to unpack.
1507 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1508 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1509
1510 // Side structure for deferring update of java frame locals until deopt occurs
1511 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1512 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1513
1514 // These only really exist to make debugging deopt problems simpler
1515
1516 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1517 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1518
1519 // The special resourceMark used during deoptimization
1520
1521 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1522 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1523
1524 intptr_t* must_deopt_id() { return _must_deopt_id; }
1525 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1526 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1527
1528 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1529 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1530
1531 Method* callee_target() const { return _callee_target; }
1532 void set_callee_target (Method* x) { _callee_target = x; }
1533
1534 // Oop results of vm runtime calls
1535 oop vm_result() const { return _vm_result; }
1536 void set_vm_result (oop x) { _vm_result = x; }
1537
1538 Metadata* vm_result_2() const { return _vm_result_2; }
1539 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1540
1541 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1542 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1543
1544 #if INCLUDE_JVMCI
1545 int pending_deoptimization() const { return _pending_deoptimization; }
1546 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1547 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1548 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1549 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1550 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1551 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1552 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1553 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1554 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1555 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1556
1557 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1558 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1559 #endif // INCLUDE_JVMCI
1560
1561 // Exception handling for compiled methods
1562 oop exception_oop() const { return _exception_oop; }
1563 address exception_pc() const { return _exception_pc; }
1564 address exception_handler_pc() const { return _exception_handler_pc; }
1565 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1566
1567 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1568 void set_exception_pc(address a) { _exception_pc = a; }
1569 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1570 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1571
1572 void clear_exception_oop_and_pc() {
1573 set_exception_oop(NULL);
1574 set_exception_pc(NULL);
1575 }
1576
1577 // Stack overflow support
1578 //
1579 // (small addresses)
1580 //
1581 // -- <-- stack_end() ---
1582 // | |
1583 // | red pages |
1584 // | |
1585 // -- <-- stack_red_zone_base() |
1586 // | |
1587 // | guard
1588 // | yellow pages zone
1589 // | |
1590 // | |
1591 // -- <-- stack_yellow_zone_base() |
1592 // | |
1593 // | |
1594 // | reserved pages |
1595 // | |
1596 // -- <-- stack_reserved_zone_base() --- ---
1597 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1598 // | zone
1599 // \|/ size
1600 // some untouched memory ---
1601 //
1602 //
1603 // --
1604 // |
1605 // | shadow zone
1606 // |
1607 // --
1608 // x frame n
1609 // --
1610 // x frame n-1
1611 // x
1612 // --
1613 // ...
1614 //
1615 // --
1616 // x frame 0
1617 // -- <-- stack_base()
1618 //
1619 // (large addresses)
1620 //
1621
1622 private:
1623 // These values are derived from flags StackRedPages, StackYellowPages,
1624 // StackReservedPages and StackShadowPages. The zone size is determined
1625 // ergonomically if page_size > 4K.
1626 static size_t _stack_red_zone_size;
1627 static size_t _stack_yellow_zone_size;
1628 static size_t _stack_reserved_zone_size;
1629 static size_t _stack_shadow_zone_size;
1630 public:
1631 inline size_t stack_available(address cur_sp);
1632
1633 static size_t stack_red_zone_size() {
1634 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1635 return _stack_red_zone_size;
1636 }
1637 static void set_stack_red_zone_size(size_t s) {
1638 assert(is_aligned(s, os::vm_page_size()),
1639 "We can not protect if the red zone size is not page aligned.");
1640 assert(_stack_red_zone_size == 0, "This should be called only once.");
1641 _stack_red_zone_size = s;
1642 }
1643 address stack_red_zone_base() {
1644 return (address)(stack_end() + stack_red_zone_size());
1645 }
1646 bool in_stack_red_zone(address a) {
1647 return a <= stack_red_zone_base() && a >= stack_end();
1648 }
1649
1650 static size_t stack_yellow_zone_size() {
1651 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1652 return _stack_yellow_zone_size;
1653 }
1654 static void set_stack_yellow_zone_size(size_t s) {
1655 assert(is_aligned(s, os::vm_page_size()),
1656 "We can not protect if the yellow zone size is not page aligned.");
1657 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1658 _stack_yellow_zone_size = s;
1659 }
1660
1661 static size_t stack_reserved_zone_size() {
1662 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1663 return _stack_reserved_zone_size;
1664 }
1665 static void set_stack_reserved_zone_size(size_t s) {
1666 assert(is_aligned(s, os::vm_page_size()),
1667 "We can not protect if the reserved zone size is not page aligned.");
1668 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1669 _stack_reserved_zone_size = s;
1670 }
1671 address stack_reserved_zone_base() {
1672 return (address)(stack_end() +
1673 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1674 }
1675 bool in_stack_reserved_zone(address a) {
1676 return (a <= stack_reserved_zone_base()) &&
1677 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1678 }
1679
1680 static size_t stack_yellow_reserved_zone_size() {
1681 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1682 }
1683 bool in_stack_yellow_reserved_zone(address a) {
1684 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1685 }
1686
1687 // Size of red + yellow + reserved zones.
1688 static size_t stack_guard_zone_size() {
1689 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1690 }
1691
1692 static size_t stack_shadow_zone_size() {
1693 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1694 return _stack_shadow_zone_size;
1695 }
1696 static void set_stack_shadow_zone_size(size_t s) {
1697 // The shadow area is not allocated or protected, so
1698 // it needs not be page aligned.
1699 // But the stack bang currently assumes that it is a
1700 // multiple of page size. This guarantees that the bang
1701 // loop touches all pages in the shadow zone.
1702 // This can be guaranteed differently, as well. E.g., if
1703 // the page size is a multiple of 4K, banging in 4K steps
1704 // suffices to touch all pages. (Some pages are banged
1705 // several times, though.)
1706 assert(is_aligned(s, os::vm_page_size()),
1707 "Stack bang assumes multiple of page size.");
1708 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1709 _stack_shadow_zone_size = s;
1710 }
1711
1712 void create_stack_guard_pages();
1713 void remove_stack_guard_pages();
1714
1715 void enable_stack_reserved_zone();
1716 void disable_stack_reserved_zone();
1717 void enable_stack_yellow_reserved_zone();
1718 void disable_stack_yellow_reserved_zone();
1719 void enable_stack_red_zone();
1720 void disable_stack_red_zone();
1721
1722 inline bool stack_guard_zone_unused();
1723 inline bool stack_yellow_reserved_zone_disabled();
1724 inline bool stack_reserved_zone_disabled();
1725 inline bool stack_guards_enabled();
1726
1727 address reserved_stack_activation() const { return _reserved_stack_activation; }
1728 void set_reserved_stack_activation(address addr) {
1729 assert(_reserved_stack_activation == stack_base()
1730 || _reserved_stack_activation == NULL
1731 || addr == stack_base(), "Must not be set twice");
1732 _reserved_stack_activation = addr;
1733 }
1734
1735 // Attempt to reguard the stack after a stack overflow may have occurred.
1736 // Returns true if (a) guard pages are not needed on this thread, (b) the
1737 // pages are already guarded, or (c) the pages were successfully reguarded.
1738 // Returns false if there is not enough stack space to reguard the pages, in
1739 // which case the caller should unwind a frame and try again. The argument
1740 // should be the caller's (approximate) sp.
1741 bool reguard_stack(address cur_sp);
1742 // Similar to above but see if current stackpoint is out of the guard area
1743 // and reguard if possible.
1744 bool reguard_stack(void);
1745
1746 address stack_overflow_limit() { return _stack_overflow_limit; }
1747 void set_stack_overflow_limit() {
1748 _stack_overflow_limit =
1749 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1750 }
1751
1752 // Misc. accessors/mutators
1753 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1754 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1755 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1756
1757 #ifndef PRODUCT
1758 void record_jump(address target, address instr, const char* file, int line);
1759 #endif // PRODUCT
1760
1761 // For assembly stub generation
1762 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1763 #ifndef PRODUCT
1764 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1765 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1766 #endif // PRODUCT
1767 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1768 static ByteSize pending_jni_exception_check_fn_offset() {
1769 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1770 }
1771 static ByteSize last_Java_sp_offset() {
1772 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1773 }
1774 static ByteSize last_Java_pc_offset() {
1775 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1776 }
1777 static ByteSize frame_anchor_offset() {
1778 return byte_offset_of(JavaThread, _anchor);
1779 }
1780 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1781 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1782 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1783 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1784 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1785 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1786 #if INCLUDE_JVMCI
1787 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1788 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1789 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1790 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1791 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1792 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1793 #endif // INCLUDE_JVMCI
1794 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1795 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1796 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1797 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1798 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1799 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1800 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1801 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1802
1803 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1804 static ByteSize should_post_on_exceptions_flag_offset() {
1805 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1806 }
1807
1808 // Returns the jni environment for this thread
1809 JNIEnv* jni_environment() { return &_jni_environment; }
1810
1811 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1812 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1813 // Only return NULL if thread is off the thread list; starting to
1814 // exit should not return NULL.
1815 if (thread_from_jni_env->is_terminated()) {
1816 thread_from_jni_env->block_if_vm_exited();
1817 return NULL;
1818 } else {
1819 return thread_from_jni_env;
1820 }
1821 }
1822
1823 // JNI critical regions. These can nest.
1824 bool in_critical() { return _jni_active_critical > 0; }
1825 bool in_last_critical() { return _jni_active_critical == 1; }
1826 inline void enter_critical();
1827 void exit_critical() {
1828 assert(Thread::current() == this, "this must be current thread");
1829 _jni_active_critical--;
1830 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1831 }
1832
1833 // Checked JNI: is the programmer required to check for exceptions, if so specify
1834 // which function name. Returning to a Java frame should implicitly clear the
1835 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1836 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1837 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1838 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1839 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1840 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1841 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1842
1843 // For deadlock detection
1844 int depth_first_number() { return _depth_first_number; }
1845 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1846
1847 private:
1848 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1849
1850 public:
1851 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1852 void add_monitor_chunk(MonitorChunk* chunk);
1853 void remove_monitor_chunk(MonitorChunk* chunk);
1854 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1855 void inc_in_deopt_handler() { _in_deopt_handler++; }
1856 void dec_in_deopt_handler() {
1857 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1858 if (_in_deopt_handler > 0) { // robustness
1859 _in_deopt_handler--;
1860 }
1861 }
1862
1863 private:
1864 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1865
1866 public:
1867
1868 // Frame iteration; calls the function f for all frames on the stack
1869 void frames_do(void f(frame*, const RegisterMap*));
1870
1871 // Memory operations
1872 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1873
1874 // Sweeper operations
1875 virtual void nmethods_do(CodeBlobClosure* cf);
1876
1877 // RedefineClasses Support
1878 void metadata_do(MetadataClosure* f);
1879
1880 // Debug method asserting thread states are correct during a handshake operation.
1881 DEBUG_ONLY(void verify_states_for_handshake();)
1882
1883 // Misc. operations
1884 char* name() const { return (char*)get_thread_name(); }
1885 void print_on(outputStream* st, bool print_extended_info) const;
1886 void print_on(outputStream* st) const { print_on(st, false); }
1887 void print_value();
1888 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1889 void print_thread_state() const PRODUCT_RETURN;
1890 void print_on_error(outputStream* st, char* buf, int buflen) const;
1891 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1892 void verify();
1893 const char* get_thread_name() const;
1894 protected:
1895 // factor out low-level mechanics for use in both normal and error cases
1896 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1897 public:
1898 const char* get_threadgroup_name() const;
1899 const char* get_parent_name() const;
1900
1901 // Accessing frames
1902 frame last_frame() {
1903 _anchor.make_walkable(this);
1904 return pd_last_frame();
1905 }
1906 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1907
1908 // Returns method at 'depth' java or native frames down the stack
1909 // Used for security checks
1910 Klass* security_get_caller_class(int depth);
1911
1912 // Print stack trace in external format
1913 void print_stack_on(outputStream* st);
1914 void print_stack() { print_stack_on(tty); }
1915
1916 // Print stack traces in various internal formats
1917 void trace_stack() PRODUCT_RETURN;
1918 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1919 void trace_frames() PRODUCT_RETURN;
1920 void trace_oops() PRODUCT_RETURN;
1921
1922 // Print an annotated view of the stack frames
1923 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1924 void validate_frame_layout() {
1925 print_frame_layout(0, true);
1926 }
1927
1928 // Returns the number of stack frames on the stack
1929 int depth() const;
1930
1931 // Function for testing deoptimization
1932 void deoptimize();
1933 void make_zombies();
1934
1935 void deoptimized_wrt_marked_nmethods();
1936
1937 public:
1938 // Returns the running thread as a JavaThread
1939 static inline JavaThread* current();
1940
1941 // Returns the active Java thread. Do not use this if you know you are calling
1942 // from a JavaThread, as it's slower than JavaThread::current. If called from
1943 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1944 // operation. You may not want that either.
1945 static JavaThread* active();
1946
1947 inline CompilerThread* as_CompilerThread();
1948
1949 protected:
1950 virtual void pre_run();
1951 virtual void run();
1952 void thread_main_inner();
1953 virtual void post_run();
1954
1955
1956 private:
1957 GrowableArray<oop>* _array_for_gc;
1958 public:
1959
1960 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1961
1962 public:
1963 // Thread local information maintained by JVMTI.
1964 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1965 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1966 // getter is used to get this JavaThread's JvmtiThreadState if it has
1967 // one which means NULL can be returned. JvmtiThreadState::state_for()
1968 // is used to get the specified JavaThread's JvmtiThreadState if it has
1969 // one or it allocates a new JvmtiThreadState for the JavaThread and
1970 // returns it. JvmtiThreadState::state_for() will return NULL only if
1971 // the specified JavaThread is exiting.
1972 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1973 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1974
1975 // JVMTI PopFrame support
1976 // Setting and clearing popframe_condition
1977 // All of these enumerated values are bits. popframe_pending
1978 // indicates that a PopFrame() has been requested and not yet been
1979 // completed. popframe_processing indicates that that PopFrame() is in
1980 // the process of being completed. popframe_force_deopt_reexecution_bit
1981 // indicates that special handling is required when returning to a
1982 // deoptimized caller.
1983 enum PopCondition {
1984 popframe_inactive = 0x00,
1985 popframe_pending_bit = 0x01,
1986 popframe_processing_bit = 0x02,
1987 popframe_force_deopt_reexecution_bit = 0x04
1988 };
1989 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1990 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1991 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1992 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1993 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1994 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1995 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1996 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1997 #ifdef CC_INTERP
1998 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1999 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
2000 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
2001 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
2002 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
2003 #endif
2004
2005 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
2006 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
2007 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
2008
2009 private:
2010 // Saved incoming arguments to popped frame.
2011 // Used only when popped interpreted frame returns to deoptimized frame.
2012 void* _popframe_preserved_args;
2013 int _popframe_preserved_args_size;
2014
2015 public:
2016 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2017 void* popframe_preserved_args();
2018 ByteSize popframe_preserved_args_size();
2019 WordSize popframe_preserved_args_size_in_words();
2020 void popframe_free_preserved_args();
2021
2022
2023 private:
2024 JvmtiThreadState *_jvmti_thread_state;
2025
2026 // Used by the interpreter in fullspeed mode for frame pop, method
2027 // entry, method exit and single stepping support. This field is
2028 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
2029 // It can be set to zero asynchronously (i.e., without a VM operation
2030 // or a lock) so we have to be very careful.
2031 int _interp_only_mode;
2032
2033 public:
2034 // used by the interpreter for fullspeed debugging support (see above)
2035 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2036 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2037 int get_interp_only_mode() { return _interp_only_mode; }
2038 void increment_interp_only_mode() { ++_interp_only_mode; }
2039 void decrement_interp_only_mode() { --_interp_only_mode; }
2040
2041 // support for cached flag that indicates whether exceptions need to be posted for this thread
2042 // if this is false, we can avoid deoptimizing when events are thrown
2043 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2044 private:
2045 int _should_post_on_exceptions_flag;
2046
2047 public:
2048 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2049 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2050
2051 private:
2052 ThreadStatistics *_thread_stat;
2053
2054 public:
2055 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2056
2057 // Return a blocker object for which this thread is blocked parking.
2058 oop current_park_blocker();
2059
2060 private:
2061 static size_t _stack_size_at_create;
2062
2063 public:
2064 static inline size_t stack_size_at_create(void) {
2065 return _stack_size_at_create;
2066 }
2067 static inline void set_stack_size_at_create(size_t value) {
2068 _stack_size_at_create = value;
2069 }
2070
2071 // Machine dependent stuff
2072 #include OS_CPU_HEADER(thread)
2073
2074 public:
2075 void set_blocked_on_compilation(bool value) {
2076 _blocked_on_compilation = value;
2077 }
2078
2079 bool blocked_on_compilation() {
2080 return _blocked_on_compilation;
2081 }
2082 protected:
2083 bool _blocked_on_compilation;
2084
2085
2086 // JSR166 per-thread parker
2087 private:
2088 Parker* _parker;
2089 public:
2090 Parker* parker() { return _parker; }
2091
2092 // Biased locking support
2093 private:
2094 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2095 public:
2096 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2097 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2098
2099 // clearing/querying jni attach status
2100 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2101 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2102 inline void set_done_attaching_via_jni();
2103
2104 // Stack dump assistance:
2105 // Track the class we want to initialize but for which we have to wait
2106 // on its init_lock() because it is already being initialized.
2107 void set_class_to_be_initialized(InstanceKlass* k);
2108 InstanceKlass* class_to_be_initialized() const;
2109
2110 private:
2111 InstanceKlass* _class_to_be_initialized;
2112
2113 };
2114
2115 // Inline implementation of JavaThread::current
2116 inline JavaThread* JavaThread::current() {
2117 Thread* thread = Thread::current();
2118 assert(thread->is_Java_thread(), "just checking");
2119 return (JavaThread*)thread;
2120 }
2121
2122 inline CompilerThread* JavaThread::as_CompilerThread() {
2123 assert(is_Compiler_thread(), "just checking");
2124 return (CompilerThread*)this;
2125 }
2126
2127 // Dedicated thread to sweep the code cache
2128 class CodeCacheSweeperThread : public JavaThread {
2129 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2130 public:
2131 CodeCacheSweeperThread();
2132 // Track the nmethod currently being scanned by the sweeper
2133 void set_scanned_compiled_method(CompiledMethod* cm) {
2134 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2135 _scanned_compiled_method = cm;
2136 }
2137
2138 // Hide sweeper thread from external view.
2139 bool is_hidden_from_external_view() const { return true; }
2140
2141 bool is_Code_cache_sweeper_thread() const { return true; }
2142
2143 // Prevent GC from unloading _scanned_compiled_method
2144 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2145 void nmethods_do(CodeBlobClosure* cf);
2146 };
2147
2148 // A thread used for Compilation.
2149 class CompilerThread : public JavaThread {
2150 friend class VMStructs;
2151 private:
2152 CompilerCounters* _counters;
2153
2154 ciEnv* _env;
2155 CompileLog* _log;
2156 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2157 CompileQueue* _queue;
2158 BufferBlob* _buffer_blob;
2159
2160 AbstractCompiler* _compiler;
2161 TimeStamp _idle_time;
2162
2163 public:
2164
2165 static CompilerThread* current();
2166
2167 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2168 ~CompilerThread();
2169
2170 bool is_Compiler_thread() const { return true; }
2171
2172 virtual bool can_call_java() const;
2173
2174 // Hide native compiler threads from external view.
2175 bool is_hidden_from_external_view() const { return !can_call_java(); }
2176
2177 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2178 AbstractCompiler* compiler() const { return _compiler; }
2179
2180 CompileQueue* queue() const { return _queue; }
2181 CompilerCounters* counters() const { return _counters; }
2182
2183 // Get/set the thread's compilation environment.
2184 ciEnv* env() { return _env; }
2185 void set_env(ciEnv* env) { _env = env; }
2186
2187 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2188 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2189
2190 // Get/set the thread's logging information
2191 CompileLog* log() { return _log; }
2192 void init_log(CompileLog* log) {
2193 // Set once, for good.
2194 assert(_log == NULL, "set only once");
2195 _log = log;
2196 }
2197
2198 void start_idle_timer() { _idle_time.update(); }
2199 jlong idle_time_millis() {
2200 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2201 }
2202
2203 #ifndef PRODUCT
2204 private:
2205 IdealGraphPrinter *_ideal_graph_printer;
2206 public:
2207 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2208 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2209 #endif
2210
2211 // Get/set the thread's current task
2212 CompileTask* task() { return _task; }
2213 void set_task(CompileTask* task) { _task = task; }
2214 };
2215
2216 inline CompilerThread* CompilerThread::current() {
2217 return JavaThread::current()->as_CompilerThread();
2218 }
2219
2220 // The active thread queue. It also keeps track of the current used
2221 // thread priorities.
2222 class Threads: AllStatic {
2223 friend class VMStructs;
2224 private:
2225 static JavaThread* _thread_list;
2226 static int _number_of_threads;
2227 static int _number_of_non_daemon_threads;
2228 static int _return_code;
2229 static int _thread_claim_parity;
2230 #ifdef ASSERT
2231 static bool _vm_complete;
2232 #endif
2233
2234 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2235 static void initialize_jsr292_core_classes(TRAPS);
2236
2237 public:
2238 // Thread management
2239 // force_daemon is a concession to JNI, where we may need to add a
2240 // thread to the thread list before allocating its thread object
2241 static void add(JavaThread* p, bool force_daemon = false);
2242 static void remove(JavaThread* p);
2243 static void non_java_threads_do(ThreadClosure* tc);
2244 static void java_threads_do(ThreadClosure* tc);
2245 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2246 static void threads_do(ThreadClosure* tc);
2247 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2248
2249 // Initializes the vm and creates the vm thread
2250 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2251 static void convert_vm_init_libraries_to_agents();
2252 static void create_vm_init_libraries();
2253 static void create_vm_init_agents();
2254 static void shutdown_vm_agents();
2255 static bool destroy_vm();
2256 // Supported VM versions via JNI
2257 // Includes JNI_VERSION_1_1
2258 static jboolean is_supported_jni_version_including_1_1(jint version);
2259 // Does not include JNI_VERSION_1_1
2260 static jboolean is_supported_jni_version(jint version);
2261
2262 // The "thread claim parity" provides a way for threads to be claimed
2263 // by parallel worker tasks.
2264 //
2265 // Each thread contains a "parity" field. A task will claim the
2266 // thread only if its parity field is the same as the global parity,
2267 // which is updated by calling change_thread_claim_parity().
2268 //
2269 // For this to work change_thread_claim_parity() needs to be called
2270 // exactly once in sequential code before starting parallel tasks
2271 // that should claim threads.
2272 //
2273 // New threads get their parity set to 0 and change_thread_claim_parity()
2274 // never sets the global parity to 0.
2275 static int thread_claim_parity() { return _thread_claim_parity; }
2276 static void change_thread_claim_parity();
2277 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2278
2279 // Apply "f->do_oop" to all root oops in all threads.
2280 // This version may only be called by sequential code.
2281 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2282 // This version may be called by sequential or parallel code.
2283 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2284
2285 // Apply "f->do_oop" to roots in all threads that
2286 // are part of compiled frames
2287 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2288
2289 static void convert_hcode_pointers();
2290 static void restore_hcode_pointers();
2291
2292 // Sweeper
2293 static void nmethods_do(CodeBlobClosure* cf);
2294
2295 // RedefineClasses support
2296 static void metadata_do(MetadataClosure* f);
2297 static void metadata_handles_do(void f(Metadata*));
2298
2299 #ifdef ASSERT
2300 static bool is_vm_complete() { return _vm_complete; }
2301 #endif // ASSERT
2302
2303 // Verification
2304 static void verify();
2305 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2306 static void print(bool print_stacks, bool internal_format) {
2307 // this function is only used by debug.cpp
2308 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2309 }
2310 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2311 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2312 int buflen, bool* found_current);
2313 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2314
2315 // Get Java threads that are waiting to enter a monitor.
2316 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2317 int count, address monitor);
2318
2319 // Get owning Java thread from the monitor's owner field.
2320 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2321 address owner);
2322
2323 // Number of threads on the active threads list
2324 static int number_of_threads() { return _number_of_threads; }
2325 // Number of non-daemon threads on the active threads list
2326 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2327
2328 // Deoptimizes all frames tied to marked nmethods
2329 static void deoptimized_wrt_marked_nmethods();
2330 };
2331
2332
2333 // Thread iterator
2334 class ThreadClosure: public StackObj {
2335 public:
2336 virtual void do_thread(Thread* thread) = 0;
2337 };
2338
2339 class SignalHandlerMark: public StackObj {
2340 private:
2341 Thread* _thread;
2342 public:
2343 SignalHandlerMark(Thread* t) {
2344 _thread = t;
2345 if (_thread) _thread->enter_signal_handler();
2346 }
2347 ~SignalHandlerMark() {
2348 if (_thread) _thread->leave_signal_handler();
2349 _thread = NULL;
2350 }
2351 };
2352
2353
2354 #endif // SHARE_RUNTIME_THREAD_HPP