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 Metadata;
92 class ResourceArea;
93
94 DEBUG_ONLY(class ResourceMark;)
95
96 class WorkerThread;
97
98 // Class hierarchy
99 // - Thread
100 // - JavaThread
101 // - various subclasses eg CompilerThread, ServiceThread
102 // - NonJavaThread
103 // - NamedThread
104 // - VMThread
105 // - ConcurrentGCThread
106 // - WorkerThread
107 // - GangWorker
108 // - GCTaskThread
109 // - WatcherThread
110 // - JfrThreadSampler
111 //
112 // All Thread subclasses must be either JavaThread or NonJavaThread.
113 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
114 // a partially constructed/destroyed Thread.
115
116 // Thread execution sequence and actions:
117 // All threads:
118 // - thread_native_entry // per-OS native entry point
119 // - stack initialization
120 // - other OS-level initialization (signal masks etc)
121 // - handshake with creating thread (if not started suspended)
122 // - this->call_run() // common shared entry point
123 // - shared common initialization
124 // - this->pre_run() // virtual per-thread-type initialization
125 // - this->run() // virtual per-thread-type "main" logic
126 // - shared common tear-down
127 // - this->post_run() // virtual per-thread-type tear-down
128 // - // 'this' no longer referenceable
129 // - OS-level tear-down (minimal)
130 // - final logging
131 //
132 // For JavaThread:
133 // - this->run() // virtual but not normally overridden
134 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
135 // - this->entry_point() // set differently for each kind of JavaThread
136
137 class Thread: public ThreadShadow {
138 friend class VMStructs;
139 friend class JVMCIVMStructs;
140 private:
141
142 #ifndef USE_LIBRARY_BASED_TLS_ONLY
143 // Current thread is maintained as a thread-local variable
144 static THREAD_LOCAL_DECL Thread* _thr_current;
145 #endif
146
147 // Thread local data area available to the GC. The internal
148 // structure and contents of this data area is GC-specific.
149 // Only GC and GC barrier code should access this data area.
150 GCThreadLocalData _gc_data;
151
152 public:
153 static ByteSize gc_data_offset() {
154 return byte_offset_of(Thread, _gc_data);
155 }
156
157 template <typename T> T* gc_data() {
158 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
159 return reinterpret_cast<T*>(&_gc_data);
160 }
161
162 // Exception handling
163 // (Note: _pending_exception and friends are in ThreadShadow)
164 //oop _pending_exception; // pending exception for current thread
165 // const char* _exception_file; // file information for exception (debugging only)
166 // int _exception_line; // line information for exception (debugging only)
167 protected:
168
169 DEBUG_ONLY(static Thread* _starting_thread;)
170
171 // Support for forcing alignment of thread objects for biased locking
172 void* _real_malloc_address;
173
174 // JavaThread lifecycle support:
175 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
176 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
177 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
178 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
179 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
180
181 ThreadsList* volatile _threads_hazard_ptr;
182 SafeThreadsListPtr* _threads_list_ptr;
183 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
184 ThreadsList* get_threads_hazard_ptr();
185 void set_threads_hazard_ptr(ThreadsList* new_list);
186 static bool is_hazard_ptr_tagged(ThreadsList* list) {
187 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
188 }
189 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
190 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
191 }
192 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
193 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
194 }
195 // This field is enabled via -XX:+EnableThreadSMRStatistics:
196 uint _nested_threads_hazard_ptr_cnt;
197 void dec_nested_threads_hazard_ptr_cnt() {
198 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
199 _nested_threads_hazard_ptr_cnt--;
200 }
201 void inc_nested_threads_hazard_ptr_cnt() {
202 _nested_threads_hazard_ptr_cnt++;
203 }
204 uint nested_threads_hazard_ptr_cnt() {
205 return _nested_threads_hazard_ptr_cnt;
206 }
207
208 public:
209 void* operator new(size_t size) throw() { return allocate(size, true); }
210 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
211 return allocate(size, false); }
212 void operator delete(void* p);
213
214 protected:
215 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
216 private:
217
218 // ***************************************************************
219 // Suspend and resume support
220 // ***************************************************************
221 //
222 // VM suspend/resume no longer exists - it was once used for various
223 // things including safepoints but was deprecated and finally removed
224 // in Java 7. Because VM suspension was considered "internal" Java-level
225 // suspension was considered "external", and this legacy naming scheme
226 // remains.
227 //
228 // External suspend/resume requests come from JVM_SuspendThread,
229 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
230 // ResumeThread. External
231 // suspend requests cause _external_suspend to be set and external
232 // resume requests cause _external_suspend to be cleared.
233 // External suspend requests do not nest on top of other external
234 // suspend requests. The higher level APIs reject suspend requests
235 // for already suspended threads.
236 //
237 // The external_suspend
238 // flag is checked by has_special_runtime_exit_condition() and java thread
239 // will self-suspend when handle_special_runtime_exit_condition() is
240 // called. Most uses of the _thread_blocked state in JavaThreads are
241 // considered the same as being externally suspended; if the blocking
242 // condition lifts, the JavaThread will self-suspend. Other places
243 // where VM checks for external_suspend include:
244 // + mutex granting (do not enter monitors when thread is suspended)
245 // + state transitions from _thread_in_native
246 //
247 // In general, java_suspend() does not wait for an external suspend
248 // request to complete. When it returns, the only guarantee is that
249 // the _external_suspend field is true.
250 //
251 // wait_for_ext_suspend_completion() is used to wait for an external
252 // suspend request to complete. External suspend requests are usually
253 // followed by some other interface call that requires the thread to
254 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
255 // the interface that requires quiescence, we give the JavaThread a
256 // chance to self-suspend before we need it to be quiescent. This
257 // improves overall suspend/query performance.
258 //
259 // _suspend_flags controls the behavior of java_ suspend/resume.
260 // It must be set under the protection of SR_lock. Read from the flag is
261 // OK without SR_lock as long as the value is only used as a hint.
262 // (e.g., check _external_suspend first without lock and then recheck
263 // inside SR_lock and finish the suspension)
264 //
265 // _suspend_flags is also overloaded for other "special conditions" so
266 // that a single check indicates whether any special action is needed
267 // eg. for async exceptions.
268 // -------------------------------------------------------------------
269 // Notes:
270 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
271 // but we still update its value to keep other part of the system (mainly
272 // JVMTI) happy. ThreadState is legacy code (see notes in
273 // osThread.hpp).
274 //
275 // 2. It would be more natural if set_external_suspend() is private and
276 // part of java_suspend(), but that probably would affect the suspend/query
277 // performance. Need more investigation on this.
278
279 // suspend/resume lock: used for self-suspend
280 Monitor* _SR_lock;
281
282 protected:
283 enum SuspendFlags {
284 // NOTE: avoid using the sign-bit as cc generates different test code
285 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
286
287 _external_suspend = 0x20000000U, // thread is asked to self suspend
288 _ext_suspended = 0x40000000U, // thread has self-suspended
289 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
290
291 _has_async_exception = 0x00000001U, // there is a pending async exception
292 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
293
294 _trace_flag = 0x00000004U // call tracing backend
295 };
296
297 // various suspension related flags - atomically updated
298 // overloaded for async exception checking in check_special_condition_for_native_trans.
299 volatile uint32_t _suspend_flags;
300
301 private:
302 int _num_nested_signal;
303
304 DEBUG_ONLY(bool _suspendible_thread;)
305
306 public:
307 void enter_signal_handler() { _num_nested_signal++; }
308 void leave_signal_handler() { _num_nested_signal--; }
309 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
310
311 // Determines if a heap allocation failure will be retried
312 // (e.g., by deoptimizing and re-executing in the interpreter).
313 // In this case, the failed allocation must raise
314 // Universe::out_of_memory_error_retry() and omit side effects
315 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
316 // and -XX:OnOutOfMemoryError.
317 virtual bool in_retryable_allocation() const { return false; }
318
319 #ifdef ASSERT
320 void set_suspendible_thread() {
321 _suspendible_thread = true;
322 }
323
324 void clear_suspendible_thread() {
325 _suspendible_thread = false;
326 }
327
328 bool is_suspendible_thread() { return _suspendible_thread; }
329 #endif
330
331 private:
332 // Active_handles points to a block of handles
333 JNIHandleBlock* _active_handles;
334
335 // One-element thread local free list
336 JNIHandleBlock* _free_handle_block;
337
338 // Point to the last handle mark
339 HandleMark* _last_handle_mark;
340
341 // Claim value for parallel iteration over threads.
342 uintx _threads_do_token;
343
344 // Support for GlobalCounter
345 private:
346 volatile uintx _rcu_counter;
347 public:
348 volatile uintx* get_rcu_counter() {
349 return &_rcu_counter;
350 }
351
352 public:
353 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
354 HandleMark* last_handle_mark() const { return _last_handle_mark; }
355 private:
356
357 #ifdef ASSERT
358 ICRefillVerifier* _missed_ic_stub_refill_verifier;
359
360 public:
361 ICRefillVerifier* missed_ic_stub_refill_verifier() {
362 return _missed_ic_stub_refill_verifier;
363 }
364
365 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
366 _missed_ic_stub_refill_verifier = verifier;
367 }
368 #endif
369
370 private:
371
372 // debug support for checking if code does allow safepoints or not
373 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
374 // mutex, or blocking on an object synchronizer (Java locking).
375 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
376 // If !allow_allocation(), then an assertion failure will happen during allocation
377 // (Hence, !allow_safepoint() => !allow_allocation()).
378 //
379 // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
380 //
381 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
382 debug_only(int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
383
384 // Used by SkipGCALot class.
385 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
386
387 friend class NoAllocVerifier;
388 friend class NoSafepointVerifier;
389 friend class PauseNoSafepointVerifier;
390 friend class GCLocker;
391
392 volatile void* _polling_page; // Thread local polling page
393
394 ThreadLocalAllocBuffer _tlab; // Thread-local eden
395 jlong _allocated_bytes; // Cumulative number of bytes allocated on
396 // the Java heap
397 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
398
399 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
400
401 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
402
403 int _vm_operation_started_count; // VM_Operation support
404 int _vm_operation_completed_count; // VM_Operation support
405
406 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
407 // is waiting to lock
408 bool _current_pending_monitor_is_from_java; // locking is from Java code
409
410 // ObjectMonitor on which this thread called Object.wait()
411 ObjectMonitor* _current_waiting_monitor;
412
413 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
414 public:
415 ObjectMonitor* omFreeList;
416 int omFreeCount; // length of omFreeList
417 int omFreeProvision; // reload chunk size
418 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
419 int omInUseCount; // length of omInUseList
420
421 #ifdef ASSERT
422 private:
423 volatile uint64_t _visited_for_critical_count;
424
425 public:
426 void set_visited_for_critical_count(uint64_t safepoint_id) {
427 assert(_visited_for_critical_count == 0, "Must be reset before set");
428 assert((safepoint_id & 0x1) == 1, "Must be odd");
429 _visited_for_critical_count = safepoint_id;
430 }
431 void reset_visited_for_critical_count(uint64_t safepoint_id) {
432 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
433 _visited_for_critical_count = 0;
434 }
435 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
436 return _visited_for_critical_count == safepoint_id;
437 }
438 #endif
439
440 public:
441 enum {
442 is_definitely_current_thread = true
443 };
444
445 // Constructor
446 Thread();
447 virtual ~Thread() = 0; // Thread is abstract.
448
449 // Manage Thread::current()
450 void initialize_thread_current();
451 static void clear_thread_current(); // TLS cleanup needed before threads terminate
452
453 protected:
454 // To be implemented by children.
455 virtual void run() = 0;
456 virtual void pre_run() = 0;
457 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
458
459 #ifdef ASSERT
460 enum RunState {
461 PRE_CALL_RUN,
462 CALL_RUN,
463 PRE_RUN,
464 RUN,
465 POST_RUN
466 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
467 };
468 RunState _run_state; // for lifecycle checks
469 #endif
470
471
472 public:
473 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
474 void call_run();
475
476 // Testers
477 virtual bool is_VM_thread() const { return false; }
478 virtual bool is_Java_thread() const { return false; }
479 virtual bool is_Compiler_thread() const { return false; }
480 virtual bool is_Code_cache_sweeper_thread() const { return false; }
481 virtual bool is_hidden_from_external_view() const { return false; }
482 virtual bool is_jvmti_agent_thread() const { return false; }
483 // True iff the thread can perform GC operations at a safepoint.
484 // Generally will be true only of VM thread and parallel GC WorkGang
485 // threads.
486 virtual bool is_GC_task_thread() const { return false; }
487 virtual bool is_Watcher_thread() const { return false; }
488 virtual bool is_ConcurrentGC_thread() const { return false; }
489 virtual bool is_Named_thread() const { return false; }
490 virtual bool is_Worker_thread() const { return false; }
491
492 // Can this thread make Java upcalls
493 virtual bool can_call_java() const { return false; }
494
495 // Casts
496 virtual WorkerThread* as_Worker_thread() const { return NULL; }
497
498 virtual char* name() const { return (char*)"Unknown thread"; }
499
500 // Returns the current thread (ASSERTS if NULL)
501 static inline Thread* current();
502 // Returns the current thread, or NULL if not attached
503 static inline Thread* current_or_null();
504 // Returns the current thread, or NULL if not attached, and is
505 // safe for use from signal-handlers
506 static inline Thread* current_or_null_safe();
507
508 // Common thread operations
509 #ifdef ASSERT
510 static void check_for_dangling_thread_pointer(Thread *thread);
511 #endif
512 static void set_priority(Thread* thread, ThreadPriority priority);
513 static ThreadPriority get_priority(const Thread* const thread);
514 static void start(Thread* thread);
515 static void interrupt(Thread* thr);
516 static bool is_interrupted(Thread* thr, bool clear_interrupted);
517
518 void set_native_thread_name(const char *name) {
519 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
520 os::set_native_thread_name(name);
521 }
522
523 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
524 Monitor* SR_lock() const { return _SR_lock; }
525
526 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
527
528 inline void set_suspend_flag(SuspendFlags f);
529 inline void clear_suspend_flag(SuspendFlags f);
530
531 inline void set_has_async_exception();
532 inline void clear_has_async_exception();
533
534 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
535
536 inline void set_critical_native_unlock();
537 inline void clear_critical_native_unlock();
538
539 inline void set_trace_flag();
540 inline void clear_trace_flag();
541
542 // Support for Unhandled Oop detection
543 // Add the field for both, fastdebug and debug, builds to keep
544 // Thread's fields layout the same.
545 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
546 #ifdef CHECK_UNHANDLED_OOPS
547 private:
548 UnhandledOops* _unhandled_oops;
549 #elif defined(ASSERT)
550 private:
551 void* _unhandled_oops;
552 #endif
553 #ifdef CHECK_UNHANDLED_OOPS
554 public:
555 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
556 // Mark oop safe for gc. It may be stack allocated but won't move.
557 void allow_unhandled_oop(oop *op) {
558 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
559 }
560 // Clear oops at safepoint so crashes point to unhandled oop violator
561 void clear_unhandled_oops() {
562 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
563 }
564 #endif // CHECK_UNHANDLED_OOPS
565
566 public:
567 #ifndef PRODUCT
568 bool skip_gcalot() { return _skip_gcalot; }
569 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
570 #endif
571
572 // Installs a pending exception to be inserted later
573 static void send_async_exception(oop thread_oop, oop java_throwable);
574
575 // Resource area
576 ResourceArea* resource_area() const { return _resource_area; }
577 void set_resource_area(ResourceArea* area) { _resource_area = area; }
578
579 OSThread* osthread() const { return _osthread; }
580 void set_osthread(OSThread* thread) { _osthread = thread; }
581
582 // JNI handle support
583 JNIHandleBlock* active_handles() const { return _active_handles; }
584 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
585 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
586 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
587
588 // Internal handle support
589 HandleArea* handle_area() const { return _handle_area; }
590 void set_handle_area(HandleArea* area) { _handle_area = area; }
591
592 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
593 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
594
595 // Thread-Local Allocation Buffer (TLAB) support
596 ThreadLocalAllocBuffer& tlab() { return _tlab; }
597 void initialize_tlab() {
598 if (UseTLAB) {
599 tlab().initialize();
600 }
601 }
602
603 jlong allocated_bytes() { return _allocated_bytes; }
604 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
605 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
606 inline jlong cooked_allocated_bytes();
607
608 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
609
610 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
611
612 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
613
614 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
615
616 // VM operation support
617 int vm_operation_ticket() { return ++_vm_operation_started_count; }
618 int vm_operation_completed_count() { return _vm_operation_completed_count; }
619 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
620
621 // For tracking the heavyweight monitor the thread is pending on.
622 ObjectMonitor* current_pending_monitor() {
623 return _current_pending_monitor;
624 }
625 void set_current_pending_monitor(ObjectMonitor* monitor) {
626 _current_pending_monitor = monitor;
627 }
628 void set_current_pending_monitor_is_from_java(bool from_java) {
629 _current_pending_monitor_is_from_java = from_java;
630 }
631 bool current_pending_monitor_is_from_java() {
632 return _current_pending_monitor_is_from_java;
633 }
634
635 // For tracking the ObjectMonitor on which this thread called Object.wait()
636 ObjectMonitor* current_waiting_monitor() {
637 return _current_waiting_monitor;
638 }
639 void set_current_waiting_monitor(ObjectMonitor* monitor) {
640 _current_waiting_monitor = monitor;
641 }
642
643 // GC support
644 // Apply "f->do_oop" to all root oops in "this".
645 // Used by JavaThread::oops_do.
646 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
647 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
648
649 // Handles the parallel case for claim_threads_do.
650 private:
651 bool claim_par_threads_do(uintx claim_token);
652 public:
653 // Requires that "claim_token" is that of the current iteration.
654 // If "is_par" is false, sets the token of "this" to
655 // "claim_token", and returns "true". If "is_par" is true,
656 // uses an atomic instruction to set the current thread's token to
657 // "claim_token", if it is not already. Returns "true" iff the
658 // calling thread does the update, this indicates that the calling thread
659 // has claimed the thread in the current iteration.
660 bool claim_threads_do(bool is_par, uintx claim_token) {
661 if (!is_par) {
662 _threads_do_token = claim_token;
663 return true;
664 } else {
665 return claim_par_threads_do(claim_token);
666 }
667 }
668
669 uintx threads_do_token() const { return _threads_do_token; }
670
671 // jvmtiRedefineClasses support
672 void metadata_handles_do(void f(Metadata*));
673
674 // Used by fast lock support
675 virtual bool is_lock_owned(address adr) const;
676
677 // Check if address is in the stack of the thread (not just for locks).
678 // Warning: the method can only be used on the running thread
679 bool is_in_stack(address adr) const;
680 // Check if address is in the usable part of the stack (excludes protected
681 // guard pages)
682 bool is_in_usable_stack(address adr) const;
683
684 // Sets this thread as starting thread. Returns failure if thread
685 // creation fails due to lack of memory, too many threads etc.
686 bool set_as_starting_thread();
687
688 protected:
689 // OS data associated with the thread
690 OSThread* _osthread; // Platform-specific thread information
691
692 // Thread local resource area for temporary allocation within the VM
693 ResourceArea* _resource_area;
694
695 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
696
697 // Thread local handle area for allocation of handles within the VM
698 HandleArea* _handle_area;
699 GrowableArray<Metadata*>* _metadata_handles;
700
701 // Support for stack overflow handling, get_thread, etc.
702 address _stack_base;
703 size_t _stack_size;
704 uintptr_t _self_raw_id; // used by get_thread (mutable)
705 int _lgrp_id;
706
707 volatile void** polling_page_addr() { return &_polling_page; }
708
709 public:
710 // Stack overflow support
711 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
712 void set_stack_base(address base) { _stack_base = base; }
713 size_t stack_size() const { return _stack_size; }
714 void set_stack_size(size_t size) { _stack_size = size; }
715 address stack_end() const { return stack_base() - stack_size(); }
716 void record_stack_base_and_size();
717 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
718
719 bool on_local_stack(address adr) const {
720 // QQQ this has knowledge of direction, ought to be a stack method
721 return (_stack_base >= adr && adr >= stack_end());
722 }
723
724 uintptr_t self_raw_id() { return _self_raw_id; }
725 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
726
727 int lgrp_id() const { return _lgrp_id; }
728 void set_lgrp_id(int value) { _lgrp_id = value; }
729
730 // Printing
731 void print_on(outputStream* st, bool print_extended_info) const;
732 virtual void print_on(outputStream* st) const { print_on(st, false); }
733 void print() const { print_on(tty); }
734 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
735 void print_value_on(outputStream* st) const;
736
737 // Debug-only code
738 #ifdef ASSERT
739 private:
740 // Deadlock detection support for Mutex locks. List of locks own by thread.
741 Monitor* _owned_locks;
742 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
743 // thus the friendship
744 friend class Mutex;
745 friend class Monitor;
746
747 public:
748 void print_owned_locks_on(outputStream* st) const;
749 void print_owned_locks() const { print_owned_locks_on(tty); }
750 Monitor* owned_locks() const { return _owned_locks; }
751 bool owns_locks() const { return owned_locks() != NULL; }
752 bool owns_locks_but_compiled_lock() const;
753
754 // Deadlock detection
755 bool allow_allocation() { return _allow_allocation_count == 0; }
756 ResourceMark* current_resource_mark() { return _current_resource_mark; }
757 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
758 #endif
759
760 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
761
762 private:
763 volatile int _jvmti_env_iteration_count;
764
765 public:
766 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
767 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
768 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
769
770 // Code generation
771 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
772 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
773 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
774
775 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
776 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
777
778 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
779
780 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
781 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
782 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
783 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
784
785 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
786
787 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
788
789 public:
790 volatile intptr_t _Stalled;
791 volatile int _TypeTag;
792 ParkEvent * _ParkEvent; // for synchronized()
793 ParkEvent * _SleepEvent; // for Thread.sleep
794 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
795 int NativeSyncRecursion; // diagnostic
796
797 volatile int _OnTrap; // Resume-at IP delta
798 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
799 jint _hashStateX; // thread-specific hashCode generator state
800 jint _hashStateY;
801 jint _hashStateZ;
802
803 // Low-level leaf-lock primitives used to implement synchronization
804 // and native monitor-mutex infrastructure.
805 // Not for general synchronization use.
806 static void SpinAcquire(volatile int * Lock, const char * Name);
807 static void SpinRelease(volatile int * Lock);
808 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
809 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
810 static void muxRelease(volatile intptr_t * Lock);
811 };
812
813 // Inline implementation of Thread::current()
814 inline Thread* Thread::current() {
815 Thread* current = current_or_null();
816 assert(current != NULL, "Thread::current() called on detached thread");
817 return current;
818 }
819
820 inline Thread* Thread::current_or_null() {
821 #ifndef USE_LIBRARY_BASED_TLS_ONLY
822 return _thr_current;
823 #else
824 if (ThreadLocalStorage::is_initialized()) {
825 return ThreadLocalStorage::thread();
826 }
827 return NULL;
828 #endif
829 }
830
831 inline Thread* Thread::current_or_null_safe() {
832 if (ThreadLocalStorage::is_initialized()) {
833 return ThreadLocalStorage::thread();
834 }
835 return NULL;
836 }
837
838 class NonJavaThread: public Thread {
839 friend class VMStructs;
840
841 NonJavaThread* volatile _next;
842
843 class List;
844 static List _the_list;
845
846 void add_to_the_list();
847 void remove_from_the_list();
848
849 protected:
850 virtual void pre_run();
851 virtual void post_run();
852
853 public:
854 NonJavaThread();
855 ~NonJavaThread();
856
857 class Iterator;
858 };
859
860 // Provides iteration over the list of NonJavaThreads.
861 // List addition occurs in pre_run(), and removal occurs in post_run(),
862 // so that only live fully-initialized threads can be found in the list.
863 // Threads created after an iterator is constructed will not be visited
864 // by the iterator. The scope of an iterator is a critical section; there
865 // must be no safepoint checks in that scope.
866 class NonJavaThread::Iterator : public StackObj {
867 uint _protect_enter;
868 NonJavaThread* _current;
869
870 // Noncopyable.
871 Iterator(const Iterator&);
872 Iterator& operator=(const Iterator&);
873
874 public:
875 Iterator();
876 ~Iterator();
877
878 bool end() const { return _current == NULL; }
879 NonJavaThread* current() const { return _current; }
880 void step();
881 };
882
883 // Name support for threads. non-JavaThread subclasses with multiple
884 // uniquely named instances should derive from this.
885 class NamedThread: public NonJavaThread {
886 friend class VMStructs;
887 enum {
888 max_name_len = 64
889 };
890 private:
891 char* _name;
892 // log JavaThread being processed by oops_do
893 JavaThread* _processed_thread;
894 uint _gc_id; // The current GC id when a thread takes part in GC
895
896 public:
897 NamedThread();
898 ~NamedThread();
899 // May only be called once per thread.
900 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
901 virtual bool is_Named_thread() const { return true; }
902 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
903 JavaThread *processed_thread() { return _processed_thread; }
904 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
905 virtual void print_on(outputStream* st) const;
906
907 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
908 uint gc_id() { return _gc_id; }
909 };
910
911 // Worker threads are named and have an id of an assigned work.
912 class WorkerThread: public NamedThread {
913 private:
914 uint _id;
915 public:
916 WorkerThread() : _id(0) { }
917 virtual bool is_Worker_thread() const { return true; }
918
919 virtual WorkerThread* as_Worker_thread() const {
920 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
921 return (WorkerThread*) this;
922 }
923
924 void set_id(uint work_id) { _id = work_id; }
925 uint id() const { return _id; }
926 };
927
928 // A single WatcherThread is used for simulating timer interrupts.
929 class WatcherThread: public NonJavaThread {
930 friend class VMStructs;
931 protected:
932 virtual void run();
933
934 private:
935 static WatcherThread* _watcher_thread;
936
937 static bool _startable;
938 // volatile due to at least one lock-free read
939 volatile static bool _should_terminate;
940 public:
941 enum SomeConstants {
942 delay_interval = 10 // interrupt delay in milliseconds
943 };
944
945 // Constructor
946 WatcherThread();
947
948 // No destruction allowed
949 ~WatcherThread() {
950 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
951 }
952
953 // Tester
954 bool is_Watcher_thread() const { return true; }
955
956 // Printing
957 char* name() const { return (char*)"VM Periodic Task Thread"; }
958 void print_on(outputStream* st) const;
959 void unpark();
960
961 // Returns the single instance of WatcherThread
962 static WatcherThread* watcher_thread() { return _watcher_thread; }
963
964 // Create and start the single instance of WatcherThread, or stop it on shutdown
965 static void start();
966 static void stop();
967 // Only allow start once the VM is sufficiently initialized
968 // Otherwise the first task to enroll will trigger the start
969 static void make_startable();
970 private:
971 int sleep() const;
972 };
973
974
975 class CompilerThread;
976
977 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
978
979 class JavaThread: public Thread {
980 friend class VMStructs;
981 friend class JVMCIVMStructs;
982 friend class WhiteBox;
983 private:
984 JavaThread* _next; // The next thread in the Threads list
985 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
986 oop _threadObj; // The Java level thread object
987
988 #ifdef ASSERT
989 private:
990 int _java_call_counter;
991
992 public:
993 int java_call_counter() { return _java_call_counter; }
994 void inc_java_call_counter() { _java_call_counter++; }
995 void dec_java_call_counter() {
996 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
997 _java_call_counter--;
998 }
999 private: // restore original namespace restriction
1000 #endif // ifdef ASSERT
1001
1002 #ifndef PRODUCT
1003 public:
1004 enum {
1005 jump_ring_buffer_size = 16
1006 };
1007 private: // restore original namespace restriction
1008 #endif
1009
1010 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1011
1012 ThreadFunction _entry_point;
1013
1014 JNIEnv _jni_environment;
1015
1016 // Deopt support
1017 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1018
1019 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
1020 // transition out of native
1021 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1022 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1023 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1024 // Because deoptimization is lazy we must save jvmti requests to set locals
1025 // in compiled frames until we deoptimize and we have an interpreter frame.
1026 // This holds the pointer to array (yeah like there might be more than one) of
1027 // description of compiled vframes that have locals that need to be updated.
1028 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1029
1030 // Handshake value for fixing 6243940. We need a place for the i2c
1031 // adapter to store the callee Method*. This value is NEVER live
1032 // across a gc point so it does NOT have to be gc'd
1033 // The handshake is open ended since we can't be certain that it will
1034 // be NULLed. This is because we rarely ever see the race and end up
1035 // in handle_wrong_method which is the backend of the handshake. See
1036 // code in i2c adapters and handle_wrong_method.
1037
1038 Method* _callee_target;
1039
1040 // Used to pass back results to the interpreter or generated code running Java code.
1041 oop _vm_result; // oop result is GC-preserved
1042 Metadata* _vm_result_2; // non-oop result
1043
1044 // See ReduceInitialCardMarks: this holds the precise space interval of
1045 // the most recent slow path allocation for which compiled code has
1046 // elided card-marks for performance along the fast-path.
1047 MemRegion _deferred_card_mark;
1048
1049 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1050 // allocated during deoptimization
1051 // and by JNI_MonitorEnter/Exit
1052
1053 // Async. requests support
1054 enum AsyncRequests {
1055 _no_async_condition = 0,
1056 _async_exception,
1057 _async_unsafe_access_error
1058 };
1059 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1060 oop _pending_async_exception;
1061
1062 // Safepoint support
1063 public: // Expose _thread_state for SafeFetchInt()
1064 volatile JavaThreadState _thread_state;
1065 private:
1066 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1067 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1068
1069 // JavaThread termination support
1070 enum TerminatedTypes {
1071 _not_terminated = 0xDEAD - 2,
1072 _thread_exiting, // JavaThread::exit() has been called for this thread
1073 _thread_terminated, // JavaThread is removed from thread list
1074 _vm_exited // JavaThread is still executing native code, but VM is terminated
1075 // only VM_Exit can set _vm_exited
1076 };
1077
1078 // In general a JavaThread's _terminated field transitions as follows:
1079 //
1080 // _not_terminated => _thread_exiting => _thread_terminated
1081 //
1082 // _vm_exited is a special value to cover the case of a JavaThread
1083 // executing native code after the VM itself is terminated.
1084 volatile TerminatedTypes _terminated;
1085 // suspend/resume support
1086 volatile bool _suspend_equivalent; // Suspend equivalent condition
1087 jint _in_deopt_handler; // count of deoptimization
1088 // handlers thread is in
1089 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1090 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1091 // never locked) when throwing an exception. Used by interpreter only.
1092
1093 // JNI attach states:
1094 enum JNIAttachStates {
1095 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1096 _attaching_via_jni, // thread is attaching via JNI
1097 _attached_via_jni // thread has attached via JNI
1098 };
1099
1100 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1101 // A native thread that is attaching via JNI starts with a value
1102 // of _attaching_via_jni and transitions to _attached_via_jni.
1103 volatile JNIAttachStates _jni_attach_state;
1104
1105 public:
1106 // State of the stack guard pages for this thread.
1107 enum StackGuardState {
1108 stack_guard_unused, // not needed
1109 stack_guard_reserved_disabled,
1110 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1111 stack_guard_enabled // enabled
1112 };
1113
1114 private:
1115
1116 #if INCLUDE_JVMCI
1117 // The _pending_* fields below are used to communicate extra information
1118 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1119
1120 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1121 int _pending_deoptimization;
1122
1123 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1124 // before the monitor has been acquired.
1125 bool _pending_monitorenter;
1126
1127 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1128 bool _pending_transfer_to_interpreter;
1129
1130 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1131 bool _adjusting_comp_level;
1132
1133 // True if in a runtime call from compiled code that will deoptimize
1134 // and re-execute a failed heap allocation in the interpreter.
1135 bool _in_retryable_allocation;
1136
1137 // An id of a speculation that JVMCI compiled code can use to further describe and
1138 // uniquely identify the speculative optimization guarded by the uncommon trap
1139 long _pending_failed_speculation;
1140
1141 // These fields are mutually exclusive in terms of live ranges.
1142 union {
1143 // Communicates the pc at which the most recent implicit exception occurred
1144 // from the signal handler to a deoptimization stub.
1145 address _implicit_exception_pc;
1146
1147 // Communicates an alternative call target to an i2c stub from a JavaCall .
1148 address _alternate_call_target;
1149 } _jvmci;
1150
1151 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1152 jlong* _jvmci_counters;
1153
1154 public:
1155 static jlong* _jvmci_old_thread_counters;
1156 static void collect_counters(typeArrayOop array);
1157 private:
1158 #endif // INCLUDE_JVMCI
1159
1160 StackGuardState _stack_guard_state;
1161
1162 // Precompute the limit of the stack as used in stack overflow checks.
1163 // We load it from here to simplify the stack overflow check in assembly.
1164 address _stack_overflow_limit;
1165 address _reserved_stack_activation;
1166
1167 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1168 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1169 // code)
1170 volatile oop _exception_oop; // Exception thrown in compiled code
1171 volatile address _exception_pc; // PC where exception happened
1172 volatile address _exception_handler_pc; // PC for handler of exception
1173 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1174
1175 private:
1176 // support for JNI critical regions
1177 jint _jni_active_critical; // count of entries into JNI critical region
1178
1179 // Checked JNI: function name requires exception check
1180 char* _pending_jni_exception_check_fn;
1181
1182 // For deadlock detection.
1183 int _depth_first_number;
1184
1185 // JVMTI PopFrame support
1186 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1187 int _popframe_condition;
1188
1189 // If reallocation of scalar replaced objects fails, we throw OOM
1190 // and during exception propagation, pop the top
1191 // _frames_to_pop_failed_realloc frames, the ones that reference
1192 // failed reallocations.
1193 int _frames_to_pop_failed_realloc;
1194
1195 #ifndef PRODUCT
1196 int _jmp_ring_index;
1197 struct {
1198 // We use intptr_t instead of address so debugger doesn't try and display strings
1199 intptr_t _target;
1200 intptr_t _instruction;
1201 const char* _file;
1202 int _line;
1203 } _jmp_ring[jump_ring_buffer_size];
1204 #endif // PRODUCT
1205
1206 friend class VMThread;
1207 friend class ThreadWaitTransition;
1208 friend class VM_Exit;
1209
1210 void initialize(); // Initialized the instance variables
1211
1212 public:
1213 // Constructor
1214 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1215 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1216 ~JavaThread();
1217
1218 #ifdef ASSERT
1219 // verify this JavaThread hasn't be published in the Threads::list yet
1220 void verify_not_published();
1221 #endif
1222
1223 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1224 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1225 _jni_environment.functions = functionTable;
1226 }
1227 struct JNINativeInterface_* get_jni_functions() {
1228 return (struct JNINativeInterface_ *)_jni_environment.functions;
1229 }
1230
1231 // This function is called at thread creation to allow
1232 // platform specific thread variables to be initialized.
1233 void cache_global_variables();
1234
1235 // Executes Shutdown.shutdown()
1236 void invoke_shutdown_hooks();
1237
1238 // Cleanup on thread exit
1239 enum ExitType {
1240 normal_exit,
1241 jni_detach
1242 };
1243 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1244
1245 void cleanup_failed_attach_current_thread(bool is_daemon);
1246
1247 // Testers
1248 virtual bool is_Java_thread() const { return true; }
1249 virtual bool can_call_java() const { return true; }
1250
1251 // Thread chain operations
1252 JavaThread* next() const { return _next; }
1253 void set_next(JavaThread* p) { _next = p; }
1254
1255 // Thread oop. threadObj() can be NULL for initial JavaThread
1256 // (or for threads attached via JNI)
1257 oop threadObj() const { return _threadObj; }
1258 void set_threadObj(oop p) { _threadObj = p; }
1259
1260 ThreadPriority java_priority() const; // Read from threadObj()
1261
1262 // Prepare thread and add to priority queue. If a priority is
1263 // not specified, use the priority of the thread object. Threads_lock
1264 // must be held while this function is called.
1265 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1266
1267 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1268 address saved_exception_pc() { return _saved_exception_pc; }
1269
1270
1271 ThreadFunction entry_point() const { return _entry_point; }
1272
1273 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1274 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1275
1276 // Last frame anchor routines
1277
1278 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1279
1280 // last_Java_sp
1281 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1282 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1283
1284 // last_Java_pc
1285
1286 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1287
1288 // Safepoint support
1289 inline JavaThreadState thread_state() const;
1290 inline void set_thread_state(JavaThreadState s);
1291 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1292 inline ThreadSafepointState* safepoint_state() const;
1293 inline void set_safepoint_state(ThreadSafepointState* state);
1294 inline bool is_at_poll_safepoint();
1295
1296 // JavaThread termination and lifecycle support:
1297 void smr_delete();
1298 bool on_thread_list() const { return _on_thread_list; }
1299 void set_on_thread_list() { _on_thread_list = true; }
1300
1301 // thread has called JavaThread::exit() or is terminated
1302 bool is_exiting() const;
1303 // thread is terminated (no longer on the threads list); we compare
1304 // against the two non-terminated values so that a freed JavaThread
1305 // will also be considered terminated.
1306 bool check_is_terminated(TerminatedTypes l_terminated) const {
1307 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1308 }
1309 bool is_terminated() const;
1310 void set_terminated(TerminatedTypes t);
1311 // special for Threads::remove() which is static:
1312 void set_terminated_value();
1313 void block_if_vm_exited();
1314
1315 bool doing_unsafe_access() { return _doing_unsafe_access; }
1316 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1317
1318 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1319 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1320
1321 inline void set_polling_page_release(void* poll_value);
1322 inline void set_polling_page(void* poll_value);
1323 inline volatile void* get_polling_page();
1324
1325 private:
1326 // Support for thread handshake operations
1327 HandshakeState _handshake;
1328 public:
1329 void set_handshake_operation(HandshakeOperation* op) {
1330 _handshake.set_operation(this, op);
1331 }
1332
1333 bool has_handshake() const {
1334 return _handshake.has_operation();
1335 }
1336
1337 void handshake_process_by_self() {
1338 _handshake.process_by_self(this);
1339 }
1340
1341 void handshake_process_by_vmthread() {
1342 _handshake.process_by_vmthread(this);
1343 }
1344
1345 // Suspend/resume support for JavaThread
1346 private:
1347 inline void set_ext_suspended();
1348 inline void clear_ext_suspended();
1349
1350 public:
1351 void java_suspend(); // higher-level suspension logic called by the public APIs
1352 void java_resume(); // higher-level resume logic called by the public APIs
1353 int java_suspend_self(); // low-level self-suspension mechanics
1354
1355 private:
1356 // mid-level wrapper around java_suspend_self to set up correct state and
1357 // check for a pending safepoint at the end
1358 void java_suspend_self_with_safepoint_check();
1359
1360 public:
1361 void check_and_wait_while_suspended() {
1362 assert(JavaThread::current() == this, "sanity check");
1363
1364 bool do_self_suspend;
1365 do {
1366 // were we externally suspended while we were waiting?
1367 do_self_suspend = handle_special_suspend_equivalent_condition();
1368 if (do_self_suspend) {
1369 // don't surprise the thread that suspended us by returning
1370 java_suspend_self();
1371 set_suspend_equivalent();
1372 }
1373 } while (do_self_suspend);
1374 }
1375 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1376 // Check for async exception in addition to safepoint and suspend request.
1377 static void check_special_condition_for_native_trans(JavaThread *thread);
1378
1379 // Same as check_special_condition_for_native_trans but finishes the
1380 // transition into thread_in_Java mode so that it can potentially
1381 // block.
1382 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1383
1384 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1385 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1386 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1387 // Warning: is_ext_suspend_completed() may temporarily drop the
1388 // SR_lock to allow the thread to reach a stable thread state if
1389 // it is currently in a transient thread state.
1390 return is_ext_suspend_completed(false /* !called_by_wait */,
1391 SuspendRetryDelay, bits);
1392 }
1393
1394 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1395 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1396 // passed as the count and delay parameters. Experiments with specific
1397 // calls to wait_for_ext_suspend_completion() can be done by passing
1398 // other values in the code. Experiments with all calls can be done
1399 // via the appropriate -XX options.
1400 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1401
1402 // test for suspend - most (all?) of these should go away
1403 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1404
1405 inline void set_external_suspend();
1406 inline void clear_external_suspend();
1407
1408 inline void set_deopt_suspend();
1409 inline void clear_deopt_suspend();
1410 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1411
1412 bool is_external_suspend() const {
1413 return (_suspend_flags & _external_suspend) != 0;
1414 }
1415 // Whenever a thread transitions from native to vm/java it must suspend
1416 // if external|deopt suspend is present.
1417 bool is_suspend_after_native() const {
1418 return (_suspend_flags & (_external_suspend | _deopt_suspend JFR_ONLY(| _trace_flag))) != 0;
1419 }
1420
1421 // external suspend request is completed
1422 bool is_ext_suspended() const {
1423 return (_suspend_flags & _ext_suspended) != 0;
1424 }
1425
1426 bool is_external_suspend_with_lock() const {
1427 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1428 return is_external_suspend();
1429 }
1430
1431 // Special method to handle a pending external suspend request
1432 // when a suspend equivalent condition lifts.
1433 bool handle_special_suspend_equivalent_condition() {
1434 assert(is_suspend_equivalent(),
1435 "should only be called in a suspend equivalence condition");
1436 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1437 bool ret = is_external_suspend();
1438 if (!ret) {
1439 // not about to self-suspend so clear suspend equivalence
1440 clear_suspend_equivalent();
1441 }
1442 // implied else:
1443 // We have a pending external suspend request so we leave the
1444 // suspend_equivalent flag set until java_suspend_self() sets
1445 // the ext_suspended flag and clears the suspend_equivalent
1446 // flag. This insures that wait_for_ext_suspend_completion()
1447 // will return consistent values.
1448 return ret;
1449 }
1450
1451 // utility methods to see if we are doing some kind of suspension
1452 bool is_being_ext_suspended() const {
1453 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1454 return is_ext_suspended() || is_external_suspend();
1455 }
1456
1457 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1458
1459 void set_suspend_equivalent() { _suspend_equivalent = true; }
1460 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1461
1462 // Thread.stop support
1463 void send_thread_stop(oop throwable);
1464 AsyncRequests clear_special_runtime_exit_condition() {
1465 AsyncRequests x = _special_runtime_exit_condition;
1466 _special_runtime_exit_condition = _no_async_condition;
1467 return x;
1468 }
1469
1470 // Are any async conditions present?
1471 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1472
1473 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1474
1475 // these next two are also used for self-suspension and async exception support
1476 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1477
1478 // Return true if JavaThread has an asynchronous condition or
1479 // if external suspension is requested.
1480 bool has_special_runtime_exit_condition() {
1481 // Because we don't use is_external_suspend_with_lock
1482 // it is possible that we won't see an asynchronous external suspend
1483 // request that has just gotten started, i.e., SR_lock grabbed but
1484 // _external_suspend field change either not made yet or not visible
1485 // yet. However, this is okay because the request is asynchronous and
1486 // we will see the new flag value the next time through. It's also
1487 // possible that the external suspend request is dropped after
1488 // we have checked is_external_suspend(), we will recheck its value
1489 // under SR_lock in java_suspend_self().
1490 return (_special_runtime_exit_condition != _no_async_condition) ||
1491 is_external_suspend() || is_trace_suspend();
1492 }
1493
1494 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1495
1496 inline void set_pending_async_exception(oop e);
1497
1498 // Fast-locking support
1499 bool is_lock_owned(address adr) const;
1500
1501 // Accessors for vframe array top
1502 // The linked list of vframe arrays are sorted on sp. This means when we
1503 // unpack the head must contain the vframe array to unpack.
1504 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1505 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1506
1507 // Side structure for deferring update of java frame locals until deopt occurs
1508 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1509 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1510
1511 // These only really exist to make debugging deopt problems simpler
1512
1513 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1514 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1515
1516 // The special resourceMark used during deoptimization
1517
1518 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1519 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1520
1521 intptr_t* must_deopt_id() { return _must_deopt_id; }
1522 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1523 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1524
1525 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1526 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1527
1528 Method* callee_target() const { return _callee_target; }
1529 void set_callee_target (Method* x) { _callee_target = x; }
1530
1531 // Oop results of vm runtime calls
1532 oop vm_result() const { return _vm_result; }
1533 void set_vm_result (oop x) { _vm_result = x; }
1534
1535 Metadata* vm_result_2() const { return _vm_result_2; }
1536 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1537
1538 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1539 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1540
1541 #if INCLUDE_JVMCI
1542 int pending_deoptimization() const { return _pending_deoptimization; }
1543 long pending_failed_speculation() const { return _pending_failed_speculation; }
1544 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1545 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1546 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1547 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1548 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1549 void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1550 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1551 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1552 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1553
1554 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1555 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1556 #endif // INCLUDE_JVMCI
1557
1558 // Exception handling for compiled methods
1559 oop exception_oop() const { return _exception_oop; }
1560 address exception_pc() const { return _exception_pc; }
1561 address exception_handler_pc() const { return _exception_handler_pc; }
1562 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1563
1564 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1565 void set_exception_pc(address a) { _exception_pc = a; }
1566 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1567 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1568
1569 void clear_exception_oop_and_pc() {
1570 set_exception_oop(NULL);
1571 set_exception_pc(NULL);
1572 }
1573
1574 // Stack overflow support
1575 //
1576 // (small addresses)
1577 //
1578 // -- <-- stack_end() ---
1579 // | |
1580 // | red pages |
1581 // | |
1582 // -- <-- stack_red_zone_base() |
1583 // | |
1584 // | guard
1585 // | yellow pages zone
1586 // | |
1587 // | |
1588 // -- <-- stack_yellow_zone_base() |
1589 // | |
1590 // | |
1591 // | reserved pages |
1592 // | |
1593 // -- <-- stack_reserved_zone_base() --- ---
1594 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1595 // | zone
1596 // \|/ size
1597 // some untouched memory ---
1598 //
1599 //
1600 // --
1601 // |
1602 // | shadow zone
1603 // |
1604 // --
1605 // x frame n
1606 // --
1607 // x frame n-1
1608 // x
1609 // --
1610 // ...
1611 //
1612 // --
1613 // x frame 0
1614 // -- <-- stack_base()
1615 //
1616 // (large addresses)
1617 //
1618
1619 private:
1620 // These values are derived from flags StackRedPages, StackYellowPages,
1621 // StackReservedPages and StackShadowPages. The zone size is determined
1622 // ergonomically if page_size > 4K.
1623 static size_t _stack_red_zone_size;
1624 static size_t _stack_yellow_zone_size;
1625 static size_t _stack_reserved_zone_size;
1626 static size_t _stack_shadow_zone_size;
1627 public:
1628 inline size_t stack_available(address cur_sp);
1629
1630 static size_t stack_red_zone_size() {
1631 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1632 return _stack_red_zone_size;
1633 }
1634 static void set_stack_red_zone_size(size_t s) {
1635 assert(is_aligned(s, os::vm_page_size()),
1636 "We can not protect if the red zone size is not page aligned.");
1637 assert(_stack_red_zone_size == 0, "This should be called only once.");
1638 _stack_red_zone_size = s;
1639 }
1640 address stack_red_zone_base() {
1641 return (address)(stack_end() + stack_red_zone_size());
1642 }
1643 bool in_stack_red_zone(address a) {
1644 return a <= stack_red_zone_base() && a >= stack_end();
1645 }
1646
1647 static size_t stack_yellow_zone_size() {
1648 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1649 return _stack_yellow_zone_size;
1650 }
1651 static void set_stack_yellow_zone_size(size_t s) {
1652 assert(is_aligned(s, os::vm_page_size()),
1653 "We can not protect if the yellow zone size is not page aligned.");
1654 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1655 _stack_yellow_zone_size = s;
1656 }
1657
1658 static size_t stack_reserved_zone_size() {
1659 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1660 return _stack_reserved_zone_size;
1661 }
1662 static void set_stack_reserved_zone_size(size_t s) {
1663 assert(is_aligned(s, os::vm_page_size()),
1664 "We can not protect if the reserved zone size is not page aligned.");
1665 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1666 _stack_reserved_zone_size = s;
1667 }
1668 address stack_reserved_zone_base() {
1669 return (address)(stack_end() +
1670 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1671 }
1672 bool in_stack_reserved_zone(address a) {
1673 return (a <= stack_reserved_zone_base()) &&
1674 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1675 }
1676
1677 static size_t stack_yellow_reserved_zone_size() {
1678 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1679 }
1680 bool in_stack_yellow_reserved_zone(address a) {
1681 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1682 }
1683
1684 // Size of red + yellow + reserved zones.
1685 static size_t stack_guard_zone_size() {
1686 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1687 }
1688
1689 static size_t stack_shadow_zone_size() {
1690 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1691 return _stack_shadow_zone_size;
1692 }
1693 static void set_stack_shadow_zone_size(size_t s) {
1694 // The shadow area is not allocated or protected, so
1695 // it needs not be page aligned.
1696 // But the stack bang currently assumes that it is a
1697 // multiple of page size. This guarantees that the bang
1698 // loop touches all pages in the shadow zone.
1699 // This can be guaranteed differently, as well. E.g., if
1700 // the page size is a multiple of 4K, banging in 4K steps
1701 // suffices to touch all pages. (Some pages are banged
1702 // several times, though.)
1703 assert(is_aligned(s, os::vm_page_size()),
1704 "Stack bang assumes multiple of page size.");
1705 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1706 _stack_shadow_zone_size = s;
1707 }
1708
1709 void create_stack_guard_pages();
1710 void remove_stack_guard_pages();
1711
1712 void enable_stack_reserved_zone();
1713 void disable_stack_reserved_zone();
1714 void enable_stack_yellow_reserved_zone();
1715 void disable_stack_yellow_reserved_zone();
1716 void enable_stack_red_zone();
1717 void disable_stack_red_zone();
1718
1719 inline bool stack_guard_zone_unused();
1720 inline bool stack_yellow_reserved_zone_disabled();
1721 inline bool stack_reserved_zone_disabled();
1722 inline bool stack_guards_enabled();
1723
1724 address reserved_stack_activation() const { return _reserved_stack_activation; }
1725 void set_reserved_stack_activation(address addr) {
1726 assert(_reserved_stack_activation == stack_base()
1727 || _reserved_stack_activation == NULL
1728 || addr == stack_base(), "Must not be set twice");
1729 _reserved_stack_activation = addr;
1730 }
1731
1732 // Attempt to reguard the stack after a stack overflow may have occurred.
1733 // Returns true if (a) guard pages are not needed on this thread, (b) the
1734 // pages are already guarded, or (c) the pages were successfully reguarded.
1735 // Returns false if there is not enough stack space to reguard the pages, in
1736 // which case the caller should unwind a frame and try again. The argument
1737 // should be the caller's (approximate) sp.
1738 bool reguard_stack(address cur_sp);
1739 // Similar to above but see if current stackpoint is out of the guard area
1740 // and reguard if possible.
1741 bool reguard_stack(void);
1742
1743 address stack_overflow_limit() { return _stack_overflow_limit; }
1744 void set_stack_overflow_limit() {
1745 _stack_overflow_limit =
1746 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1747 }
1748
1749 // Misc. accessors/mutators
1750 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1751 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1752 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1753
1754 #ifndef PRODUCT
1755 void record_jump(address target, address instr, const char* file, int line);
1756 #endif // PRODUCT
1757
1758 // For assembly stub generation
1759 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1760 #ifndef PRODUCT
1761 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1762 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1763 #endif // PRODUCT
1764 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1765 static ByteSize pending_jni_exception_check_fn_offset() {
1766 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1767 }
1768 static ByteSize last_Java_sp_offset() {
1769 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1770 }
1771 static ByteSize last_Java_pc_offset() {
1772 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1773 }
1774 static ByteSize frame_anchor_offset() {
1775 return byte_offset_of(JavaThread, _anchor);
1776 }
1777 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1778 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1779 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1780 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1781 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1782 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1783 #if INCLUDE_JVMCI
1784 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1785 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1786 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1787 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1788 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1789 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1790 #endif // INCLUDE_JVMCI
1791 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1792 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1793 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1794 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1795 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1796 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1797 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1798 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1799
1800 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1801 static ByteSize should_post_on_exceptions_flag_offset() {
1802 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1803 }
1804
1805 // Returns the jni environment for this thread
1806 JNIEnv* jni_environment() { return &_jni_environment; }
1807
1808 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1809 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1810 // Only return NULL if thread is off the thread list; starting to
1811 // exit should not return NULL.
1812 if (thread_from_jni_env->is_terminated()) {
1813 thread_from_jni_env->block_if_vm_exited();
1814 return NULL;
1815 } else {
1816 return thread_from_jni_env;
1817 }
1818 }
1819
1820 // JNI critical regions. These can nest.
1821 bool in_critical() { return _jni_active_critical > 0; }
1822 bool in_last_critical() { return _jni_active_critical == 1; }
1823 inline void enter_critical();
1824 void exit_critical() {
1825 assert(Thread::current() == this, "this must be current thread");
1826 _jni_active_critical--;
1827 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1828 }
1829
1830 // Checked JNI: is the programmer required to check for exceptions, if so specify
1831 // which function name. Returning to a Java frame should implicitly clear the
1832 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1833 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1834 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1835 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1836 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1837 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1838 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1839
1840 // For deadlock detection
1841 int depth_first_number() { return _depth_first_number; }
1842 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1843
1844 private:
1845 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1846
1847 public:
1848 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1849 void add_monitor_chunk(MonitorChunk* chunk);
1850 void remove_monitor_chunk(MonitorChunk* chunk);
1851 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1852 void inc_in_deopt_handler() { _in_deopt_handler++; }
1853 void dec_in_deopt_handler() {
1854 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1855 if (_in_deopt_handler > 0) { // robustness
1856 _in_deopt_handler--;
1857 }
1858 }
1859
1860 private:
1861 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1862
1863 public:
1864
1865 // Frame iteration; calls the function f for all frames on the stack
1866 void frames_do(void f(frame*, const RegisterMap*));
1867
1868 // Memory operations
1869 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1870
1871 // Sweeper operations
1872 virtual void nmethods_do(CodeBlobClosure* cf);
1873
1874 // RedefineClasses Support
1875 void metadata_do(MetadataClosure* f);
1876
1877 // Debug method asserting thread states are correct during a handshake operation.
1878 DEBUG_ONLY(void verify_states_for_handshake();)
1879
1880 // Misc. operations
1881 char* name() const { return (char*)get_thread_name(); }
1882 void print_on(outputStream* st, bool print_extended_info) const;
1883 void print_on(outputStream* st) const { print_on(st, false); }
1884 void print_value();
1885 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1886 void print_thread_state() const PRODUCT_RETURN;
1887 void print_on_error(outputStream* st, char* buf, int buflen) const;
1888 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1889 void verify();
1890 const char* get_thread_name() const;
1891 protected:
1892 // factor out low-level mechanics for use in both normal and error cases
1893 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1894 public:
1895 const char* get_threadgroup_name() const;
1896 const char* get_parent_name() const;
1897
1898 // Accessing frames
1899 frame last_frame() {
1900 _anchor.make_walkable(this);
1901 return pd_last_frame();
1902 }
1903 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1904
1905 // Returns method at 'depth' java or native frames down the stack
1906 // Used for security checks
1907 Klass* security_get_caller_class(int depth);
1908
1909 // Print stack trace in external format
1910 void print_stack_on(outputStream* st);
1911 void print_stack() { print_stack_on(tty); }
1912
1913 // Print stack traces in various internal formats
1914 void trace_stack() PRODUCT_RETURN;
1915 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1916 void trace_frames() PRODUCT_RETURN;
1917 void trace_oops() PRODUCT_RETURN;
1918
1919 // Print an annotated view of the stack frames
1920 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1921 void validate_frame_layout() {
1922 print_frame_layout(0, true);
1923 }
1924
1925 // Returns the number of stack frames on the stack
1926 int depth() const;
1927
1928 // Function for testing deoptimization
1929 void deoptimize();
1930 void make_zombies();
1931
1932 void deoptimized_wrt_marked_nmethods();
1933
1934 public:
1935 // Returns the running thread as a JavaThread
1936 static inline JavaThread* current();
1937
1938 // Returns the active Java thread. Do not use this if you know you are calling
1939 // from a JavaThread, as it's slower than JavaThread::current. If called from
1940 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1941 // operation. You may not want that either.
1942 static JavaThread* active();
1943
1944 inline CompilerThread* as_CompilerThread();
1945
1946 protected:
1947 virtual void pre_run();
1948 virtual void run();
1949 void thread_main_inner();
1950 virtual void post_run();
1951
1952
1953 private:
1954 GrowableArray<oop>* _array_for_gc;
1955 public:
1956
1957 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1958
1959 public:
1960 // Thread local information maintained by JVMTI.
1961 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1962 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1963 // getter is used to get this JavaThread's JvmtiThreadState if it has
1964 // one which means NULL can be returned. JvmtiThreadState::state_for()
1965 // is used to get the specified JavaThread's JvmtiThreadState if it has
1966 // one or it allocates a new JvmtiThreadState for the JavaThread and
1967 // returns it. JvmtiThreadState::state_for() will return NULL only if
1968 // the specified JavaThread is exiting.
1969 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1970 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1971
1972 // JVMTI PopFrame support
1973 // Setting and clearing popframe_condition
1974 // All of these enumerated values are bits. popframe_pending
1975 // indicates that a PopFrame() has been requested and not yet been
1976 // completed. popframe_processing indicates that that PopFrame() is in
1977 // the process of being completed. popframe_force_deopt_reexecution_bit
1978 // indicates that special handling is required when returning to a
1979 // deoptimized caller.
1980 enum PopCondition {
1981 popframe_inactive = 0x00,
1982 popframe_pending_bit = 0x01,
1983 popframe_processing_bit = 0x02,
1984 popframe_force_deopt_reexecution_bit = 0x04
1985 };
1986 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1987 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1988 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1989 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1990 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1991 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1992 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1993 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1994 #ifdef CC_INTERP
1995 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1996 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1997 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1998 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1999 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
2000 #endif
2001
2002 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
2003 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
2004 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
2005
2006 private:
2007 // Saved incoming arguments to popped frame.
2008 // Used only when popped interpreted frame returns to deoptimized frame.
2009 void* _popframe_preserved_args;
2010 int _popframe_preserved_args_size;
2011
2012 public:
2013 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2014 void* popframe_preserved_args();
2015 ByteSize popframe_preserved_args_size();
2016 WordSize popframe_preserved_args_size_in_words();
2017 void popframe_free_preserved_args();
2018
2019
2020 private:
2021 JvmtiThreadState *_jvmti_thread_state;
2022
2023 // Used by the interpreter in fullspeed mode for frame pop, method
2024 // entry, method exit and single stepping support. This field is
2025 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
2026 // It can be set to zero asynchronously (i.e., without a VM operation
2027 // or a lock) so we have to be very careful.
2028 int _interp_only_mode;
2029
2030 public:
2031 // used by the interpreter for fullspeed debugging support (see above)
2032 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2033 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2034 int get_interp_only_mode() { return _interp_only_mode; }
2035 void increment_interp_only_mode() { ++_interp_only_mode; }
2036 void decrement_interp_only_mode() { --_interp_only_mode; }
2037
2038 // support for cached flag that indicates whether exceptions need to be posted for this thread
2039 // if this is false, we can avoid deoptimizing when events are thrown
2040 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2041 private:
2042 int _should_post_on_exceptions_flag;
2043
2044 public:
2045 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2046 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2047
2048 private:
2049 ThreadStatistics *_thread_stat;
2050
2051 public:
2052 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2053
2054 // Return a blocker object for which this thread is blocked parking.
2055 oop current_park_blocker();
2056
2057 private:
2058 static size_t _stack_size_at_create;
2059
2060 public:
2061 static inline size_t stack_size_at_create(void) {
2062 return _stack_size_at_create;
2063 }
2064 static inline void set_stack_size_at_create(size_t value) {
2065 _stack_size_at_create = value;
2066 }
2067
2068 // Machine dependent stuff
2069 #include OS_CPU_HEADER(thread)
2070
2071 public:
2072 void set_blocked_on_compilation(bool value) {
2073 _blocked_on_compilation = value;
2074 }
2075
2076 bool blocked_on_compilation() {
2077 return _blocked_on_compilation;
2078 }
2079 protected:
2080 bool _blocked_on_compilation;
2081
2082
2083 // JSR166 per-thread parker
2084 private:
2085 Parker* _parker;
2086 public:
2087 Parker* parker() { return _parker; }
2088
2089 // Biased locking support
2090 private:
2091 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2092 public:
2093 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2094 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2095
2096 // clearing/querying jni attach status
2097 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2098 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2099 inline void set_done_attaching_via_jni();
2100
2101 // Stack dump assistance:
2102 // Track the class we want to initialize but for which we have to wait
2103 // on its init_lock() because it is already being initialized.
2104 void set_class_to_be_initialized(InstanceKlass* k);
2105 InstanceKlass* class_to_be_initialized() const;
2106
2107 private:
2108 InstanceKlass* _class_to_be_initialized;
2109
2110 };
2111
2112 // Inline implementation of JavaThread::current
2113 inline JavaThread* JavaThread::current() {
2114 Thread* thread = Thread::current();
2115 assert(thread->is_Java_thread(), "just checking");
2116 return (JavaThread*)thread;
2117 }
2118
2119 inline CompilerThread* JavaThread::as_CompilerThread() {
2120 assert(is_Compiler_thread(), "just checking");
2121 return (CompilerThread*)this;
2122 }
2123
2124 // Dedicated thread to sweep the code cache
2125 class CodeCacheSweeperThread : public JavaThread {
2126 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2127 public:
2128 CodeCacheSweeperThread();
2129 // Track the nmethod currently being scanned by the sweeper
2130 void set_scanned_compiled_method(CompiledMethod* cm) {
2131 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2132 _scanned_compiled_method = cm;
2133 }
2134
2135 // Hide sweeper thread from external view.
2136 bool is_hidden_from_external_view() const { return true; }
2137
2138 bool is_Code_cache_sweeper_thread() const { return true; }
2139
2140 // Prevent GC from unloading _scanned_compiled_method
2141 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2142 void nmethods_do(CodeBlobClosure* cf);
2143 };
2144
2145 // A thread used for Compilation.
2146 class CompilerThread : public JavaThread {
2147 friend class VMStructs;
2148 private:
2149 CompilerCounters* _counters;
2150
2151 ciEnv* _env;
2152 CompileLog* _log;
2153 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2154 CompileQueue* _queue;
2155 BufferBlob* _buffer_blob;
2156
2157 AbstractCompiler* _compiler;
2158 TimeStamp _idle_time;
2159
2160 public:
2161
2162 static CompilerThread* current();
2163
2164 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2165 ~CompilerThread();
2166
2167 bool is_Compiler_thread() const { return true; }
2168
2169 virtual bool can_call_java() const;
2170
2171 // Hide native compiler threads from external view.
2172 bool is_hidden_from_external_view() const { return !can_call_java(); }
2173
2174 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2175 AbstractCompiler* compiler() const { return _compiler; }
2176
2177 CompileQueue* queue() const { return _queue; }
2178 CompilerCounters* counters() const { return _counters; }
2179
2180 // Get/set the thread's compilation environment.
2181 ciEnv* env() { return _env; }
2182 void set_env(ciEnv* env) { _env = env; }
2183
2184 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2185 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2186
2187 // Get/set the thread's logging information
2188 CompileLog* log() { return _log; }
2189 void init_log(CompileLog* log) {
2190 // Set once, for good.
2191 assert(_log == NULL, "set only once");
2192 _log = log;
2193 }
2194
2195 void start_idle_timer() { _idle_time.update(); }
2196 jlong idle_time_millis() {
2197 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2198 }
2199
2200 #ifndef PRODUCT
2201 private:
2202 IdealGraphPrinter *_ideal_graph_printer;
2203 public:
2204 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2205 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2206 #endif
2207
2208 // Get/set the thread's current task
2209 CompileTask* task() { return _task; }
2210 void set_task(CompileTask* task) { _task = task; }
2211 };
2212
2213 inline CompilerThread* CompilerThread::current() {
2214 return JavaThread::current()->as_CompilerThread();
2215 }
2216
2217 // The active thread queue. It also keeps track of the current used
2218 // thread priorities.
2219 class Threads: AllStatic {
2220 friend class VMStructs;
2221 private:
2222 static JavaThread* _thread_list;
2223 static int _number_of_threads;
2224 static int _number_of_non_daemon_threads;
2225 static int _return_code;
2226 static uintx _thread_claim_token;
2227 #ifdef ASSERT
2228 static bool _vm_complete;
2229 #endif
2230
2231 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2232 static void initialize_jsr292_core_classes(TRAPS);
2233
2234 public:
2235 // Thread management
2236 // force_daemon is a concession to JNI, where we may need to add a
2237 // thread to the thread list before allocating its thread object
2238 static void add(JavaThread* p, bool force_daemon = false);
2239 static void remove(JavaThread* p, bool is_daemon);
2240 static void non_java_threads_do(ThreadClosure* tc);
2241 static void java_threads_do(ThreadClosure* tc);
2242 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2243 static void threads_do(ThreadClosure* tc);
2244 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2245
2246 // Initializes the vm and creates the vm thread
2247 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2248 static void convert_vm_init_libraries_to_agents();
2249 static void create_vm_init_libraries();
2250 static void create_vm_init_agents();
2251 static void shutdown_vm_agents();
2252 static bool destroy_vm();
2253 // Supported VM versions via JNI
2254 // Includes JNI_VERSION_1_1
2255 static jboolean is_supported_jni_version_including_1_1(jint version);
2256 // Does not include JNI_VERSION_1_1
2257 static jboolean is_supported_jni_version(jint version);
2258
2259 // The "thread claim token" provides a way for threads to be claimed
2260 // by parallel worker tasks.
2261 //
2262 // Each thread contains a "token" field. A task will claim the
2263 // thread only if its token is different from the global token,
2264 // which is updated by calling change_thread_claim_token(). When
2265 // a thread is claimed, it's token is set to the global token value
2266 // so other threads in the same iteration pass won't claim it.
2267 //
2268 // For this to work change_thread_claim_token() needs to be called
2269 // exactly once in sequential code before starting parallel tasks
2270 // that should claim threads.
2271 //
2272 // New threads get their token set to 0 and change_thread_claim_token()
2273 // never sets the global token to 0.
2274 static uintx thread_claim_token() { return _thread_claim_token; }
2275 static void change_thread_claim_token();
2276 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2277
2278 // Apply "f->do_oop" to all root oops in all threads.
2279 // This version may only be called by sequential code.
2280 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2281 // This version may be called by sequential or parallel code.
2282 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2283
2284 // Apply "f->do_oop" to roots in all threads that
2285 // are part of compiled frames
2286 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2287
2288 static void convert_hcode_pointers();
2289 static void restore_hcode_pointers();
2290
2291 // Sweeper
2292 static void nmethods_do(CodeBlobClosure* cf);
2293
2294 // RedefineClasses support
2295 static void metadata_do(MetadataClosure* f);
2296 static void metadata_handles_do(void f(Metadata*));
2297
2298 #ifdef ASSERT
2299 static bool is_vm_complete() { return _vm_complete; }
2300 #endif // ASSERT
2301
2302 // Verification
2303 static void verify();
2304 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2305 static void print(bool print_stacks, bool internal_format) {
2306 // this function is only used by debug.cpp
2307 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2308 }
2309 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2310 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2311 int buflen, bool* found_current);
2312 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2313
2314 // Get Java threads that are waiting to enter a monitor.
2315 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2316 int count, address monitor);
2317
2318 // Get owning Java thread from the monitor's owner field.
2319 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2320 address owner);
2321
2322 // Number of threads on the active threads list
2323 static int number_of_threads() { return _number_of_threads; }
2324 // Number of non-daemon threads on the active threads list
2325 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2326
2327 // Deoptimizes all frames tied to marked nmethods
2328 static void deoptimized_wrt_marked_nmethods();
2329
2330 struct Test; // For private gtest access.
2331 };
2332
2333
2334 // Thread iterator
2335 class ThreadClosure: public StackObj {
2336 public:
2337 virtual void do_thread(Thread* thread) = 0;
2338 };
2339
2340 class SignalHandlerMark: public StackObj {
2341 private:
2342 Thread* _thread;
2343 public:
2344 SignalHandlerMark(Thread* t) {
2345 _thread = t;
2346 if (_thread) _thread->enter_signal_handler();
2347 }
2348 ~SignalHandlerMark() {
2349 if (_thread) _thread->leave_signal_handler();
2350 _thread = NULL;
2351 }
2352 };
2353
2354
2355 #endif // SHARE_RUNTIME_THREAD_HPP