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 volatile bool omShouldDeflateIdleMonitors; // should deflate idle monitors
421
422 #ifdef ASSERT
423 private:
424 volatile uint64_t _visited_for_critical_count;
425
426 public:
427 void set_visited_for_critical_count(uint64_t safepoint_id) {
428 assert(_visited_for_critical_count == 0, "Must be reset before set");
429 assert((safepoint_id & 0x1) == 1, "Must be odd");
430 _visited_for_critical_count = safepoint_id;
431 }
432 void reset_visited_for_critical_count(uint64_t safepoint_id) {
433 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
434 _visited_for_critical_count = 0;
435 }
436 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
437 return _visited_for_critical_count == safepoint_id;
438 }
439 #endif
440
441 public:
442 enum {
443 is_definitely_current_thread = true
444 };
445
446 // Constructor
447 Thread();
448 virtual ~Thread() = 0; // Thread is abstract.
449
450 // Manage Thread::current()
451 void initialize_thread_current();
452 static void clear_thread_current(); // TLS cleanup needed before threads terminate
453
454 protected:
455 // To be implemented by children.
456 virtual void run() = 0;
457 virtual void pre_run() = 0;
458 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
459
460 #ifdef ASSERT
461 enum RunState {
462 PRE_CALL_RUN,
463 CALL_RUN,
464 PRE_RUN,
465 RUN,
466 POST_RUN
467 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
468 };
469 RunState _run_state; // for lifecycle checks
470 #endif
471
472
473 public:
474 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
475 void call_run();
476
477 // Testers
478 virtual bool is_VM_thread() const { return false; }
479 virtual bool is_Java_thread() const { return false; }
480 virtual bool is_Compiler_thread() const { return false; }
481 virtual bool is_Code_cache_sweeper_thread() const { return false; }
482 virtual bool is_hidden_from_external_view() const { return false; }
483 virtual bool is_jvmti_agent_thread() const { return false; }
484 // True iff the thread can perform GC operations at a safepoint.
485 // Generally will be true only of VM thread and parallel GC WorkGang
486 // threads.
487 virtual bool is_GC_task_thread() const { return false; }
488 virtual bool is_Watcher_thread() const { return false; }
489 virtual bool is_ConcurrentGC_thread() const { return false; }
490 virtual bool is_Named_thread() const { return false; }
491 virtual bool is_Worker_thread() const { return false; }
492
493 // Can this thread make Java upcalls
494 virtual bool can_call_java() const { return false; }
495
496 // Casts
497 virtual WorkerThread* as_Worker_thread() const { return NULL; }
498
499 virtual char* name() const { return (char*)"Unknown thread"; }
500
501 // Returns the current thread (ASSERTS if NULL)
502 static inline Thread* current();
503 // Returns the current thread, or NULL if not attached
504 static inline Thread* current_or_null();
505 // Returns the current thread, or NULL if not attached, and is
506 // safe for use from signal-handlers
507 static inline Thread* current_or_null_safe();
508
509 // Common thread operations
510 #ifdef ASSERT
511 static void check_for_dangling_thread_pointer(Thread *thread);
512 #endif
513 static void set_priority(Thread* thread, ThreadPriority priority);
514 static ThreadPriority get_priority(const Thread* const thread);
515 static void start(Thread* thread);
516 static void interrupt(Thread* thr);
517 static bool is_interrupted(Thread* thr, bool clear_interrupted);
518
519 void set_native_thread_name(const char *name) {
520 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
521 os::set_native_thread_name(name);
522 }
523
524 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
525 Monitor* SR_lock() const { return _SR_lock; }
526
527 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
528
529 inline void set_suspend_flag(SuspendFlags f);
530 inline void clear_suspend_flag(SuspendFlags f);
531
532 inline void set_has_async_exception();
533 inline void clear_has_async_exception();
534
535 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
536
537 inline void set_critical_native_unlock();
538 inline void clear_critical_native_unlock();
539
540 inline void set_trace_flag();
541 inline void clear_trace_flag();
542
543 // Support for Unhandled Oop detection
544 // Add the field for both, fastdebug and debug, builds to keep
545 // Thread's fields layout the same.
546 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
547 #ifdef CHECK_UNHANDLED_OOPS
548 private:
549 UnhandledOops* _unhandled_oops;
550 #elif defined(ASSERT)
551 private:
552 void* _unhandled_oops;
553 #endif
554 #ifdef CHECK_UNHANDLED_OOPS
555 public:
556 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
557 // Mark oop safe for gc. It may be stack allocated but won't move.
558 void allow_unhandled_oop(oop *op) {
559 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
560 }
561 // Clear oops at safepoint so crashes point to unhandled oop violator
562 void clear_unhandled_oops() {
563 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
564 }
565 #endif // CHECK_UNHANDLED_OOPS
566
567 public:
568 #ifndef PRODUCT
569 bool skip_gcalot() { return _skip_gcalot; }
570 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
571 #endif
572
573 // Installs a pending exception to be inserted later
574 static void send_async_exception(oop thread_oop, oop java_throwable);
575
576 // Resource area
577 ResourceArea* resource_area() const { return _resource_area; }
578 void set_resource_area(ResourceArea* area) { _resource_area = area; }
579
580 OSThread* osthread() const { return _osthread; }
581 void set_osthread(OSThread* thread) { _osthread = thread; }
582
583 // JNI handle support
584 JNIHandleBlock* active_handles() const { return _active_handles; }
585 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
586 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
587 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
588
589 // Internal handle support
590 HandleArea* handle_area() const { return _handle_area; }
591 void set_handle_area(HandleArea* area) { _handle_area = area; }
592
593 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
594 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
595
596 // Thread-Local Allocation Buffer (TLAB) support
597 ThreadLocalAllocBuffer& tlab() { return _tlab; }
598 void initialize_tlab() {
599 if (UseTLAB) {
600 tlab().initialize();
601 }
602 }
603
604 jlong allocated_bytes() { return _allocated_bytes; }
605 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
606 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
607 inline jlong cooked_allocated_bytes();
608
609 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
610
611 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
612
613 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
614
615 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
616
617 // VM operation support
618 int vm_operation_ticket() { return ++_vm_operation_started_count; }
619 int vm_operation_completed_count() { return _vm_operation_completed_count; }
620 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
621
622 // For tracking the heavyweight monitor the thread is pending on.
623 ObjectMonitor* current_pending_monitor() {
624 return _current_pending_monitor;
625 }
626 void set_current_pending_monitor(ObjectMonitor* monitor) {
627 _current_pending_monitor = monitor;
628 }
629 void set_current_pending_monitor_is_from_java(bool from_java) {
630 _current_pending_monitor_is_from_java = from_java;
631 }
632 bool current_pending_monitor_is_from_java() {
633 return _current_pending_monitor_is_from_java;
634 }
635
636 // For tracking the ObjectMonitor on which this thread called Object.wait()
637 ObjectMonitor* current_waiting_monitor() {
638 return _current_waiting_monitor;
639 }
640 void set_current_waiting_monitor(ObjectMonitor* monitor) {
641 _current_waiting_monitor = monitor;
642 }
643
644 // GC support
645 // Apply "f->do_oop" to all root oops in "this".
646 // Used by JavaThread::oops_do.
647 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
648 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
649
650 // Handles the parallel case for claim_threads_do.
651 private:
652 bool claim_par_threads_do(uintx claim_token);
653 public:
654 // Requires that "claim_token" is that of the current iteration.
655 // If "is_par" is false, sets the token of "this" to
656 // "claim_token", and returns "true". If "is_par" is true,
657 // uses an atomic instruction to set the current thread's token to
658 // "claim_token", if it is not already. Returns "true" iff the
659 // calling thread does the update, this indicates that the calling thread
660 // has claimed the thread in the current iteration.
661 bool claim_threads_do(bool is_par, uintx claim_token) {
662 if (!is_par) {
663 _threads_do_token = claim_token;
664 return true;
665 } else {
666 return claim_par_threads_do(claim_token);
667 }
668 }
669
670 uintx threads_do_token() const { return _threads_do_token; }
671
672 // jvmtiRedefineClasses support
673 void metadata_handles_do(void f(Metadata*));
674
675 // Used by fast lock support
676 virtual bool is_lock_owned(address adr) const;
677
678 // Check if address is in the stack of the thread (not just for locks).
679 // Warning: the method can only be used on the running thread
680 bool is_in_stack(address adr) const;
681 // Check if address is in the usable part of the stack (excludes protected
682 // guard pages)
683 bool is_in_usable_stack(address adr) const;
684
685 // Sets this thread as starting thread. Returns failure if thread
686 // creation fails due to lack of memory, too many threads etc.
687 bool set_as_starting_thread();
688
689 protected:
690 // OS data associated with the thread
691 OSThread* _osthread; // Platform-specific thread information
692
693 // Thread local resource area for temporary allocation within the VM
694 ResourceArea* _resource_area;
695
696 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
697
698 // Thread local handle area for allocation of handles within the VM
699 HandleArea* _handle_area;
700 GrowableArray<Metadata*>* _metadata_handles;
701
702 // Support for stack overflow handling, get_thread, etc.
703 address _stack_base;
704 size_t _stack_size;
705 uintptr_t _self_raw_id; // used by get_thread (mutable)
706 int _lgrp_id;
707
708 volatile void** polling_page_addr() { return &_polling_page; }
709
710 public:
711 // Stack overflow support
712 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
713 void set_stack_base(address base) { _stack_base = base; }
714 size_t stack_size() const { return _stack_size; }
715 void set_stack_size(size_t size) { _stack_size = size; }
716 address stack_end() const { return stack_base() - stack_size(); }
717 void record_stack_base_and_size();
718 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
719
720 bool on_local_stack(address adr) const {
721 // QQQ this has knowledge of direction, ought to be a stack method
722 return (_stack_base >= adr && adr >= stack_end());
723 }
724
725 uintptr_t self_raw_id() { return _self_raw_id; }
726 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
727
728 int lgrp_id() const { return _lgrp_id; }
729 void set_lgrp_id(int value) { _lgrp_id = value; }
730
731 // Printing
732 void print_on(outputStream* st, bool print_extended_info) const;
733 virtual void print_on(outputStream* st) const { print_on(st, false); }
734 void print() const { print_on(tty); }
735 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
736 void print_value_on(outputStream* st) const;
737
738 // Debug-only code
739 #ifdef ASSERT
740 private:
741 // Deadlock detection support for Mutex locks. List of locks own by thread.
742 Monitor* _owned_locks;
743 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
744 // thus the friendship
745 friend class Mutex;
746 friend class Monitor;
747
748 public:
749 void print_owned_locks_on(outputStream* st) const;
750 void print_owned_locks() const { print_owned_locks_on(tty); }
751 Monitor* owned_locks() const { return _owned_locks; }
752 bool owns_locks() const { return owned_locks() != NULL; }
753 bool owns_locks_but_compiled_lock() const;
754
755 // Deadlock detection
756 bool allow_allocation() { return _allow_allocation_count == 0; }
757 ResourceMark* current_resource_mark() { return _current_resource_mark; }
758 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
759 #endif
760
761 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
762
763 private:
764 volatile int _jvmti_env_iteration_count;
765
766 public:
767 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
768 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
769 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
770
771 // Code generation
772 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
773 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
774 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
775
776 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
777 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
778
779 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
780
781 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
782 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
783 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
784 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
785
786 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
787
788 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
789
790 public:
791 volatile intptr_t _Stalled;
792 volatile int _TypeTag;
793 ParkEvent * _ParkEvent; // for synchronized()
794 ParkEvent * _SleepEvent; // for Thread.sleep
795 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
796 int NativeSyncRecursion; // diagnostic
797
798 volatile int _OnTrap; // Resume-at IP delta
799 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
800 jint _hashStateX; // thread-specific hashCode generator state
801 jint _hashStateY;
802 jint _hashStateZ;
803
804 // Low-level leaf-lock primitives used to implement synchronization
805 // and native monitor-mutex infrastructure.
806 // Not for general synchronization use.
807 static void SpinAcquire(volatile int * Lock, const char * Name);
808 static void SpinRelease(volatile int * Lock);
809 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
810 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
811 static void muxRelease(volatile intptr_t * Lock);
812 };
813
814 // Inline implementation of Thread::current()
815 inline Thread* Thread::current() {
816 Thread* current = current_or_null();
817 assert(current != NULL, "Thread::current() called on detached thread");
818 return current;
819 }
820
821 inline Thread* Thread::current_or_null() {
822 #ifndef USE_LIBRARY_BASED_TLS_ONLY
823 return _thr_current;
824 #else
825 if (ThreadLocalStorage::is_initialized()) {
826 return ThreadLocalStorage::thread();
827 }
828 return NULL;
829 #endif
830 }
831
832 inline Thread* Thread::current_or_null_safe() {
833 if (ThreadLocalStorage::is_initialized()) {
834 return ThreadLocalStorage::thread();
835 }
836 return NULL;
837 }
838
839 class NonJavaThread: public Thread {
840 friend class VMStructs;
841
842 NonJavaThread* volatile _next;
843
844 class List;
845 static List _the_list;
846
847 void add_to_the_list();
848 void remove_from_the_list();
849
850 protected:
851 virtual void pre_run();
852 virtual void post_run();
853
854 public:
855 NonJavaThread();
856 ~NonJavaThread();
857
858 class Iterator;
859 };
860
861 // Provides iteration over the list of NonJavaThreads.
862 // List addition occurs in pre_run(), and removal occurs in post_run(),
863 // so that only live fully-initialized threads can be found in the list.
864 // Threads created after an iterator is constructed will not be visited
865 // by the iterator. The scope of an iterator is a critical section; there
866 // must be no safepoint checks in that scope.
867 class NonJavaThread::Iterator : public StackObj {
868 uint _protect_enter;
869 NonJavaThread* _current;
870
871 // Noncopyable.
872 Iterator(const Iterator&);
873 Iterator& operator=(const Iterator&);
874
875 public:
876 Iterator();
877 ~Iterator();
878
879 bool end() const { return _current == NULL; }
880 NonJavaThread* current() const { return _current; }
881 void step();
882 };
883
884 // Name support for threads. non-JavaThread subclasses with multiple
885 // uniquely named instances should derive from this.
886 class NamedThread: public NonJavaThread {
887 friend class VMStructs;
888 enum {
889 max_name_len = 64
890 };
891 private:
892 char* _name;
893 // log JavaThread being processed by oops_do
894 JavaThread* _processed_thread;
895 uint _gc_id; // The current GC id when a thread takes part in GC
896
897 public:
898 NamedThread();
899 ~NamedThread();
900 // May only be called once per thread.
901 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
902 virtual bool is_Named_thread() const { return true; }
903 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
904 JavaThread *processed_thread() { return _processed_thread; }
905 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
906 virtual void print_on(outputStream* st) const;
907
908 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
909 uint gc_id() { return _gc_id; }
910 };
911
912 // Worker threads are named and have an id of an assigned work.
913 class WorkerThread: public NamedThread {
914 private:
915 uint _id;
916 public:
917 WorkerThread() : _id(0) { }
918 virtual bool is_Worker_thread() const { return true; }
919
920 virtual WorkerThread* as_Worker_thread() const {
921 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
922 return (WorkerThread*) this;
923 }
924
925 void set_id(uint work_id) { _id = work_id; }
926 uint id() const { return _id; }
927 };
928
929 // A single WatcherThread is used for simulating timer interrupts.
930 class WatcherThread: public NonJavaThread {
931 friend class VMStructs;
932 protected:
933 virtual void run();
934
935 private:
936 static WatcherThread* _watcher_thread;
937
938 static bool _startable;
939 // volatile due to at least one lock-free read
940 volatile static bool _should_terminate;
941 public:
942 enum SomeConstants {
943 delay_interval = 10 // interrupt delay in milliseconds
944 };
945
946 // Constructor
947 WatcherThread();
948
949 // No destruction allowed
950 ~WatcherThread() {
951 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
952 }
953
954 // Tester
955 bool is_Watcher_thread() const { return true; }
956
957 // Printing
958 char* name() const { return (char*)"VM Periodic Task Thread"; }
959 void print_on(outputStream* st) const;
960 void unpark();
961
962 // Returns the single instance of WatcherThread
963 static WatcherThread* watcher_thread() { return _watcher_thread; }
964
965 // Create and start the single instance of WatcherThread, or stop it on shutdown
966 static void start();
967 static void stop();
968 // Only allow start once the VM is sufficiently initialized
969 // Otherwise the first task to enroll will trigger the start
970 static void make_startable();
971 private:
972 int sleep() const;
973 };
974
975
976 class CompilerThread;
977
978 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
979
980 class JavaThread: public Thread {
981 friend class VMStructs;
982 friend class JVMCIVMStructs;
983 friend class WhiteBox;
984 private:
985 JavaThread* _next; // The next thread in the Threads list
986 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
987 oop _threadObj; // The Java level thread object
988
989 #ifdef ASSERT
990 private:
991 int _java_call_counter;
992
993 public:
994 int java_call_counter() { return _java_call_counter; }
995 void inc_java_call_counter() { _java_call_counter++; }
996 void dec_java_call_counter() {
997 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
998 _java_call_counter--;
999 }
1000 private: // restore original namespace restriction
1001 #endif // ifdef ASSERT
1002
1003 #ifndef PRODUCT
1004 public:
1005 enum {
1006 jump_ring_buffer_size = 16
1007 };
1008 private: // restore original namespace restriction
1009 #endif
1010
1011 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1012
1013 ThreadFunction _entry_point;
1014
1015 JNIEnv _jni_environment;
1016
1017 // Deopt support
1018 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1019
1020 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
1021 // transition out of native
1022 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1023 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1024 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1025 // Because deoptimization is lazy we must save jvmti requests to set locals
1026 // in compiled frames until we deoptimize and we have an interpreter frame.
1027 // This holds the pointer to array (yeah like there might be more than one) of
1028 // description of compiled vframes that have locals that need to be updated.
1029 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1030
1031 // Handshake value for fixing 6243940. We need a place for the i2c
1032 // adapter to store the callee Method*. This value is NEVER live
1033 // across a gc point so it does NOT have to be gc'd
1034 // The handshake is open ended since we can't be certain that it will
1035 // be NULLed. This is because we rarely ever see the race and end up
1036 // in handle_wrong_method which is the backend of the handshake. See
1037 // code in i2c adapters and handle_wrong_method.
1038
1039 Method* _callee_target;
1040
1041 // Used to pass back results to the interpreter or generated code running Java code.
1042 oop _vm_result; // oop result is GC-preserved
1043 Metadata* _vm_result_2; // non-oop result
1044
1045 // See ReduceInitialCardMarks: this holds the precise space interval of
1046 // the most recent slow path allocation for which compiled code has
1047 // elided card-marks for performance along the fast-path.
1048 MemRegion _deferred_card_mark;
1049
1050 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1051 // allocated during deoptimization
1052 // and by JNI_MonitorEnter/Exit
1053
1054 // Async. requests support
1055 enum AsyncRequests {
1056 _no_async_condition = 0,
1057 _async_exception,
1058 _async_unsafe_access_error
1059 };
1060 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1061 oop _pending_async_exception;
1062
1063 // Safepoint support
1064 public: // Expose _thread_state for SafeFetchInt()
1065 volatile JavaThreadState _thread_state;
1066 private:
1067 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1068 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1069
1070 // JavaThread termination support
1071 enum TerminatedTypes {
1072 _not_terminated = 0xDEAD - 2,
1073 _thread_exiting, // JavaThread::exit() has been called for this thread
1074 _thread_terminated, // JavaThread is removed from thread list
1075 _vm_exited // JavaThread is still executing native code, but VM is terminated
1076 // only VM_Exit can set _vm_exited
1077 };
1078
1079 // In general a JavaThread's _terminated field transitions as follows:
1080 //
1081 // _not_terminated => _thread_exiting => _thread_terminated
1082 //
1083 // _vm_exited is a special value to cover the case of a JavaThread
1084 // executing native code after the VM itself is terminated.
1085 volatile TerminatedTypes _terminated;
1086 // suspend/resume support
1087 volatile bool _suspend_equivalent; // Suspend equivalent condition
1088 jint _in_deopt_handler; // count of deoptimization
1089 // handlers thread is in
1090 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1091 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1092 // never locked) when throwing an exception. Used by interpreter only.
1093
1094 // JNI attach states:
1095 enum JNIAttachStates {
1096 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1097 _attaching_via_jni, // thread is attaching via JNI
1098 _attached_via_jni // thread has attached via JNI
1099 };
1100
1101 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1102 // A native thread that is attaching via JNI starts with a value
1103 // of _attaching_via_jni and transitions to _attached_via_jni.
1104 volatile JNIAttachStates _jni_attach_state;
1105
1106 public:
1107 // State of the stack guard pages for this thread.
1108 enum StackGuardState {
1109 stack_guard_unused, // not needed
1110 stack_guard_reserved_disabled,
1111 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1112 stack_guard_enabled // enabled
1113 };
1114
1115 private:
1116
1117 #if INCLUDE_JVMCI
1118 // The _pending_* fields below are used to communicate extra information
1119 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1120
1121 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1122 int _pending_deoptimization;
1123
1124 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1125 // before the monitor has been acquired.
1126 bool _pending_monitorenter;
1127
1128 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1129 bool _pending_transfer_to_interpreter;
1130
1131 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1132 bool _adjusting_comp_level;
1133
1134 // True if in a runtime call from compiled code that will deoptimize
1135 // and re-execute a failed heap allocation in the interpreter.
1136 bool _in_retryable_allocation;
1137
1138 // An id of a speculation that JVMCI compiled code can use to further describe and
1139 // uniquely identify the speculative optimization guarded by the uncommon trap
1140 long _pending_failed_speculation;
1141
1142 // These fields are mutually exclusive in terms of live ranges.
1143 union {
1144 // Communicates the pc at which the most recent implicit exception occurred
1145 // from the signal handler to a deoptimization stub.
1146 address _implicit_exception_pc;
1147
1148 // Communicates an alternative call target to an i2c stub from a JavaCall .
1149 address _alternate_call_target;
1150 } _jvmci;
1151
1152 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1153 jlong* _jvmci_counters;
1154
1155 public:
1156 static jlong* _jvmci_old_thread_counters;
1157 static void collect_counters(typeArrayOop array);
1158 private:
1159 #endif // INCLUDE_JVMCI
1160
1161 StackGuardState _stack_guard_state;
1162
1163 // Precompute the limit of the stack as used in stack overflow checks.
1164 // We load it from here to simplify the stack overflow check in assembly.
1165 address _stack_overflow_limit;
1166 address _reserved_stack_activation;
1167
1168 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1169 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1170 // code)
1171 volatile oop _exception_oop; // Exception thrown in compiled code
1172 volatile address _exception_pc; // PC where exception happened
1173 volatile address _exception_handler_pc; // PC for handler of exception
1174 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1175
1176 private:
1177 // support for JNI critical regions
1178 jint _jni_active_critical; // count of entries into JNI critical region
1179
1180 // Checked JNI: function name requires exception check
1181 char* _pending_jni_exception_check_fn;
1182
1183 // For deadlock detection.
1184 int _depth_first_number;
1185
1186 // JVMTI PopFrame support
1187 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1188 int _popframe_condition;
1189
1190 // If reallocation of scalar replaced objects fails, we throw OOM
1191 // and during exception propagation, pop the top
1192 // _frames_to_pop_failed_realloc frames, the ones that reference
1193 // failed reallocations.
1194 int _frames_to_pop_failed_realloc;
1195
1196 #ifndef PRODUCT
1197 int _jmp_ring_index;
1198 struct {
1199 // We use intptr_t instead of address so debugger doesn't try and display strings
1200 intptr_t _target;
1201 intptr_t _instruction;
1202 const char* _file;
1203 int _line;
1204 } _jmp_ring[jump_ring_buffer_size];
1205 #endif // PRODUCT
1206
1207 friend class VMThread;
1208 friend class ThreadWaitTransition;
1209 friend class VM_Exit;
1210
1211 void initialize(); // Initialized the instance variables
1212
1213 public:
1214 // Constructor
1215 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1216 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1217 ~JavaThread();
1218
1219 #ifdef ASSERT
1220 // verify this JavaThread hasn't be published in the Threads::list yet
1221 void verify_not_published();
1222 #endif
1223
1224 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1225 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1226 _jni_environment.functions = functionTable;
1227 }
1228 struct JNINativeInterface_* get_jni_functions() {
1229 return (struct JNINativeInterface_ *)_jni_environment.functions;
1230 }
1231
1232 // This function is called at thread creation to allow
1233 // platform specific thread variables to be initialized.
1234 void cache_global_variables();
1235
1236 // Executes Shutdown.shutdown()
1237 void invoke_shutdown_hooks();
1238
1239 // Cleanup on thread exit
1240 enum ExitType {
1241 normal_exit,
1242 jni_detach
1243 };
1244 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1245
1246 void cleanup_failed_attach_current_thread(bool is_daemon);
1247
1248 // Testers
1249 virtual bool is_Java_thread() const { return true; }
1250 virtual bool can_call_java() const { return true; }
1251
1252 // Thread chain operations
1253 JavaThread* next() const { return _next; }
1254 void set_next(JavaThread* p) { _next = p; }
1255
1256 // Thread oop. threadObj() can be NULL for initial JavaThread
1257 // (or for threads attached via JNI)
1258 oop threadObj() const { return _threadObj; }
1259 void set_threadObj(oop p) { _threadObj = p; }
1260
1261 ThreadPriority java_priority() const; // Read from threadObj()
1262
1263 // Prepare thread and add to priority queue. If a priority is
1264 // not specified, use the priority of the thread object. Threads_lock
1265 // must be held while this function is called.
1266 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1267
1268 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1269 address saved_exception_pc() { return _saved_exception_pc; }
1270
1271
1272 ThreadFunction entry_point() const { return _entry_point; }
1273
1274 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1275 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1276
1277 // Last frame anchor routines
1278
1279 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1280
1281 // last_Java_sp
1282 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1283 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1284
1285 // last_Java_pc
1286
1287 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1288
1289 // Safepoint support
1290 inline JavaThreadState thread_state() const;
1291 inline void set_thread_state(JavaThreadState s);
1292 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1293 inline ThreadSafepointState* safepoint_state() const;
1294 inline void set_safepoint_state(ThreadSafepointState* state);
1295 inline bool is_at_poll_safepoint();
1296
1297 // JavaThread termination and lifecycle support:
1298 void smr_delete();
1299 bool on_thread_list() const { return _on_thread_list; }
1300 void set_on_thread_list() { _on_thread_list = true; }
1301
1302 // thread has called JavaThread::exit() or is terminated
1303 bool is_exiting() const;
1304 // thread is terminated (no longer on the threads list); we compare
1305 // against the two non-terminated values so that a freed JavaThread
1306 // will also be considered terminated.
1307 bool check_is_terminated(TerminatedTypes l_terminated) const {
1308 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1309 }
1310 bool is_terminated() const;
1311 void set_terminated(TerminatedTypes t);
1312 // special for Threads::remove() which is static:
1313 void set_terminated_value();
1314 void block_if_vm_exited();
1315
1316 bool doing_unsafe_access() { return _doing_unsafe_access; }
1317 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1318
1319 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1320 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1321
1322 inline void set_polling_page_release(void* poll_value);
1323 inline void set_polling_page(void* poll_value);
1324 inline volatile void* get_polling_page();
1325
1326 private:
1327 // Support for thread handshake operations
1328 HandshakeState _handshake;
1329 public:
1330 void set_handshake_operation(HandshakeOperation* op) {
1331 _handshake.set_operation(this, op);
1332 }
1333
1334 bool has_handshake() const {
1335 return _handshake.has_operation();
1336 }
1337
1338 void handshake_process_by_self() {
1339 _handshake.process_by_self(this);
1340 }
1341
1342 void handshake_process_by_vmthread() {
1343 _handshake.process_by_vmthread(this);
1344 }
1345
1346 // Suspend/resume support for JavaThread
1347 private:
1348 inline void set_ext_suspended();
1349 inline void clear_ext_suspended();
1350
1351 public:
1352 void java_suspend(); // higher-level suspension logic called by the public APIs
1353 void java_resume(); // higher-level resume logic called by the public APIs
1354 int java_suspend_self(); // low-level self-suspension mechanics
1355
1356 private:
1357 // mid-level wrapper around java_suspend_self to set up correct state and
1358 // check for a pending safepoint at the end
1359 void java_suspend_self_with_safepoint_check();
1360
1361 public:
1362 void check_and_wait_while_suspended() {
1363 assert(JavaThread::current() == this, "sanity check");
1364
1365 bool do_self_suspend;
1366 do {
1367 // were we externally suspended while we were waiting?
1368 do_self_suspend = handle_special_suspend_equivalent_condition();
1369 if (do_self_suspend) {
1370 // don't surprise the thread that suspended us by returning
1371 java_suspend_self();
1372 set_suspend_equivalent();
1373 }
1374 } while (do_self_suspend);
1375 }
1376 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1377 // Check for async exception in addition to safepoint and suspend request.
1378 static void check_special_condition_for_native_trans(JavaThread *thread);
1379
1380 // Same as check_special_condition_for_native_trans but finishes the
1381 // transition into thread_in_Java mode so that it can potentially
1382 // block.
1383 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1384
1385 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1386 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1387 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1388 // Warning: is_ext_suspend_completed() may temporarily drop the
1389 // SR_lock to allow the thread to reach a stable thread state if
1390 // it is currently in a transient thread state.
1391 return is_ext_suspend_completed(false /* !called_by_wait */,
1392 SuspendRetryDelay, bits);
1393 }
1394
1395 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1396 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1397 // passed as the count and delay parameters. Experiments with specific
1398 // calls to wait_for_ext_suspend_completion() can be done by passing
1399 // other values in the code. Experiments with all calls can be done
1400 // via the appropriate -XX options.
1401 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1402
1403 // test for suspend - most (all?) of these should go away
1404 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1405
1406 inline void set_external_suspend();
1407 inline void clear_external_suspend();
1408
1409 inline void set_deopt_suspend();
1410 inline void clear_deopt_suspend();
1411 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1412
1413 bool is_external_suspend() const {
1414 return (_suspend_flags & _external_suspend) != 0;
1415 }
1416 // Whenever a thread transitions from native to vm/java it must suspend
1417 // if external|deopt suspend is present.
1418 bool is_suspend_after_native() const {
1419 return (_suspend_flags & (_external_suspend | _deopt_suspend JFR_ONLY(| _trace_flag))) != 0;
1420 }
1421
1422 // external suspend request is completed
1423 bool is_ext_suspended() const {
1424 return (_suspend_flags & _ext_suspended) != 0;
1425 }
1426
1427 bool is_external_suspend_with_lock() const {
1428 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1429 return is_external_suspend();
1430 }
1431
1432 // Special method to handle a pending external suspend request
1433 // when a suspend equivalent condition lifts.
1434 bool handle_special_suspend_equivalent_condition() {
1435 assert(is_suspend_equivalent(),
1436 "should only be called in a suspend equivalence condition");
1437 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1438 bool ret = is_external_suspend();
1439 if (!ret) {
1440 // not about to self-suspend so clear suspend equivalence
1441 clear_suspend_equivalent();
1442 }
1443 // implied else:
1444 // We have a pending external suspend request so we leave the
1445 // suspend_equivalent flag set until java_suspend_self() sets
1446 // the ext_suspended flag and clears the suspend_equivalent
1447 // flag. This insures that wait_for_ext_suspend_completion()
1448 // will return consistent values.
1449 return ret;
1450 }
1451
1452 // utility methods to see if we are doing some kind of suspension
1453 bool is_being_ext_suspended() const {
1454 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1455 return is_ext_suspended() || is_external_suspend();
1456 }
1457
1458 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1459
1460 void set_suspend_equivalent() { _suspend_equivalent = true; }
1461 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1462
1463 // Thread.stop support
1464 void send_thread_stop(oop throwable);
1465 AsyncRequests clear_special_runtime_exit_condition() {
1466 AsyncRequests x = _special_runtime_exit_condition;
1467 _special_runtime_exit_condition = _no_async_condition;
1468 return x;
1469 }
1470
1471 // Are any async conditions present?
1472 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1473
1474 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1475
1476 // these next two are also used for self-suspension and async exception support
1477 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1478
1479 // Return true if JavaThread has an asynchronous condition or
1480 // if external suspension is requested.
1481 bool has_special_runtime_exit_condition() {
1482 // Because we don't use is_external_suspend_with_lock
1483 // it is possible that we won't see an asynchronous external suspend
1484 // request that has just gotten started, i.e., SR_lock grabbed but
1485 // _external_suspend field change either not made yet or not visible
1486 // yet. However, this is okay because the request is asynchronous and
1487 // we will see the new flag value the next time through. It's also
1488 // possible that the external suspend request is dropped after
1489 // we have checked is_external_suspend(), we will recheck its value
1490 // under SR_lock in java_suspend_self().
1491 return (_special_runtime_exit_condition != _no_async_condition) ||
1492 is_external_suspend() || is_trace_suspend();
1493 }
1494
1495 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1496
1497 inline void set_pending_async_exception(oop e);
1498
1499 // Fast-locking support
1500 bool is_lock_owned(address adr) const;
1501
1502 // Accessors for vframe array top
1503 // The linked list of vframe arrays are sorted on sp. This means when we
1504 // unpack the head must contain the vframe array to unpack.
1505 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1506 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1507
1508 // Side structure for deferring update of java frame locals until deopt occurs
1509 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1510 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1511
1512 // These only really exist to make debugging deopt problems simpler
1513
1514 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1515 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1516
1517 // The special resourceMark used during deoptimization
1518
1519 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1520 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1521
1522 intptr_t* must_deopt_id() { return _must_deopt_id; }
1523 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1524 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1525
1526 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1527 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1528
1529 Method* callee_target() const { return _callee_target; }
1530 void set_callee_target (Method* x) { _callee_target = x; }
1531
1532 // Oop results of vm runtime calls
1533 oop vm_result() const { return _vm_result; }
1534 void set_vm_result (oop x) { _vm_result = x; }
1535
1536 Metadata* vm_result_2() const { return _vm_result_2; }
1537 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1538
1539 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1540 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1541
1542 #if INCLUDE_JVMCI
1543 int pending_deoptimization() const { return _pending_deoptimization; }
1544 long pending_failed_speculation() const { return _pending_failed_speculation; }
1545 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1546 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1547 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1548 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1549 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1550 void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1551 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1552 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1553 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1554
1555 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1556 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1557 #endif // INCLUDE_JVMCI
1558
1559 // Exception handling for compiled methods
1560 oop exception_oop() const { return _exception_oop; }
1561 address exception_pc() const { return _exception_pc; }
1562 address exception_handler_pc() const { return _exception_handler_pc; }
1563 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1564
1565 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1566 void set_exception_pc(address a) { _exception_pc = a; }
1567 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1568 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1569
1570 void clear_exception_oop_and_pc() {
1571 set_exception_oop(NULL);
1572 set_exception_pc(NULL);
1573 }
1574
1575 // Stack overflow support
1576 //
1577 // (small addresses)
1578 //
1579 // -- <-- stack_end() ---
1580 // | |
1581 // | red pages |
1582 // | |
1583 // -- <-- stack_red_zone_base() |
1584 // | |
1585 // | guard
1586 // | yellow pages zone
1587 // | |
1588 // | |
1589 // -- <-- stack_yellow_zone_base() |
1590 // | |
1591 // | |
1592 // | reserved pages |
1593 // | |
1594 // -- <-- stack_reserved_zone_base() --- ---
1595 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1596 // | zone
1597 // \|/ size
1598 // some untouched memory ---
1599 //
1600 //
1601 // --
1602 // |
1603 // | shadow zone
1604 // |
1605 // --
1606 // x frame n
1607 // --
1608 // x frame n-1
1609 // x
1610 // --
1611 // ...
1612 //
1613 // --
1614 // x frame 0
1615 // -- <-- stack_base()
1616 //
1617 // (large addresses)
1618 //
1619
1620 private:
1621 // These values are derived from flags StackRedPages, StackYellowPages,
1622 // StackReservedPages and StackShadowPages. The zone size is determined
1623 // ergonomically if page_size > 4K.
1624 static size_t _stack_red_zone_size;
1625 static size_t _stack_yellow_zone_size;
1626 static size_t _stack_reserved_zone_size;
1627 static size_t _stack_shadow_zone_size;
1628 public:
1629 inline size_t stack_available(address cur_sp);
1630
1631 static size_t stack_red_zone_size() {
1632 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1633 return _stack_red_zone_size;
1634 }
1635 static void set_stack_red_zone_size(size_t s) {
1636 assert(is_aligned(s, os::vm_page_size()),
1637 "We can not protect if the red zone size is not page aligned.");
1638 assert(_stack_red_zone_size == 0, "This should be called only once.");
1639 _stack_red_zone_size = s;
1640 }
1641 address stack_red_zone_base() {
1642 return (address)(stack_end() + stack_red_zone_size());
1643 }
1644 bool in_stack_red_zone(address a) {
1645 return a <= stack_red_zone_base() && a >= stack_end();
1646 }
1647
1648 static size_t stack_yellow_zone_size() {
1649 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1650 return _stack_yellow_zone_size;
1651 }
1652 static void set_stack_yellow_zone_size(size_t s) {
1653 assert(is_aligned(s, os::vm_page_size()),
1654 "We can not protect if the yellow zone size is not page aligned.");
1655 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1656 _stack_yellow_zone_size = s;
1657 }
1658
1659 static size_t stack_reserved_zone_size() {
1660 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1661 return _stack_reserved_zone_size;
1662 }
1663 static void set_stack_reserved_zone_size(size_t s) {
1664 assert(is_aligned(s, os::vm_page_size()),
1665 "We can not protect if the reserved zone size is not page aligned.");
1666 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1667 _stack_reserved_zone_size = s;
1668 }
1669 address stack_reserved_zone_base() {
1670 return (address)(stack_end() +
1671 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1672 }
1673 bool in_stack_reserved_zone(address a) {
1674 return (a <= stack_reserved_zone_base()) &&
1675 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1676 }
1677
1678 static size_t stack_yellow_reserved_zone_size() {
1679 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1680 }
1681 bool in_stack_yellow_reserved_zone(address a) {
1682 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1683 }
1684
1685 // Size of red + yellow + reserved zones.
1686 static size_t stack_guard_zone_size() {
1687 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1688 }
1689
1690 static size_t stack_shadow_zone_size() {
1691 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1692 return _stack_shadow_zone_size;
1693 }
1694 static void set_stack_shadow_zone_size(size_t s) {
1695 // The shadow area is not allocated or protected, so
1696 // it needs not be page aligned.
1697 // But the stack bang currently assumes that it is a
1698 // multiple of page size. This guarantees that the bang
1699 // loop touches all pages in the shadow zone.
1700 // This can be guaranteed differently, as well. E.g., if
1701 // the page size is a multiple of 4K, banging in 4K steps
1702 // suffices to touch all pages. (Some pages are banged
1703 // several times, though.)
1704 assert(is_aligned(s, os::vm_page_size()),
1705 "Stack bang assumes multiple of page size.");
1706 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1707 _stack_shadow_zone_size = s;
1708 }
1709
1710 void create_stack_guard_pages();
1711 void remove_stack_guard_pages();
1712
1713 void enable_stack_reserved_zone();
1714 void disable_stack_reserved_zone();
1715 void enable_stack_yellow_reserved_zone();
1716 void disable_stack_yellow_reserved_zone();
1717 void enable_stack_red_zone();
1718 void disable_stack_red_zone();
1719
1720 inline bool stack_guard_zone_unused();
1721 inline bool stack_yellow_reserved_zone_disabled();
1722 inline bool stack_reserved_zone_disabled();
1723 inline bool stack_guards_enabled();
1724
1725 address reserved_stack_activation() const { return _reserved_stack_activation; }
1726 void set_reserved_stack_activation(address addr) {
1727 assert(_reserved_stack_activation == stack_base()
1728 || _reserved_stack_activation == NULL
1729 || addr == stack_base(), "Must not be set twice");
1730 _reserved_stack_activation = addr;
1731 }
1732
1733 // Attempt to reguard the stack after a stack overflow may have occurred.
1734 // Returns true if (a) guard pages are not needed on this thread, (b) the
1735 // pages are already guarded, or (c) the pages were successfully reguarded.
1736 // Returns false if there is not enough stack space to reguard the pages, in
1737 // which case the caller should unwind a frame and try again. The argument
1738 // should be the caller's (approximate) sp.
1739 bool reguard_stack(address cur_sp);
1740 // Similar to above but see if current stackpoint is out of the guard area
1741 // and reguard if possible.
1742 bool reguard_stack(void);
1743
1744 address stack_overflow_limit() { return _stack_overflow_limit; }
1745 void set_stack_overflow_limit() {
1746 _stack_overflow_limit =
1747 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1748 }
1749
1750 // Misc. accessors/mutators
1751 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1752 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1753 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1754
1755 #ifndef PRODUCT
1756 void record_jump(address target, address instr, const char* file, int line);
1757 #endif // PRODUCT
1758
1759 // For assembly stub generation
1760 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1761 #ifndef PRODUCT
1762 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1763 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1764 #endif // PRODUCT
1765 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1766 static ByteSize pending_jni_exception_check_fn_offset() {
1767 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1768 }
1769 static ByteSize last_Java_sp_offset() {
1770 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1771 }
1772 static ByteSize last_Java_pc_offset() {
1773 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1774 }
1775 static ByteSize frame_anchor_offset() {
1776 return byte_offset_of(JavaThread, _anchor);
1777 }
1778 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1779 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1780 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1781 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1782 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1783 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1784 #if INCLUDE_JVMCI
1785 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1786 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1787 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1788 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1789 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1790 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1791 #endif // INCLUDE_JVMCI
1792 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1793 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1794 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1795 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1796 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1797 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1798 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1799 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1800
1801 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1802 static ByteSize should_post_on_exceptions_flag_offset() {
1803 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1804 }
1805
1806 // Returns the jni environment for this thread
1807 JNIEnv* jni_environment() { return &_jni_environment; }
1808
1809 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1810 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1811 // Only return NULL if thread is off the thread list; starting to
1812 // exit should not return NULL.
1813 if (thread_from_jni_env->is_terminated()) {
1814 thread_from_jni_env->block_if_vm_exited();
1815 return NULL;
1816 } else {
1817 return thread_from_jni_env;
1818 }
1819 }
1820
1821 // JNI critical regions. These can nest.
1822 bool in_critical() { return _jni_active_critical > 0; }
1823 bool in_last_critical() { return _jni_active_critical == 1; }
1824 inline void enter_critical();
1825 void exit_critical() {
1826 assert(Thread::current() == this, "this must be current thread");
1827 _jni_active_critical--;
1828 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1829 }
1830
1831 // Checked JNI: is the programmer required to check for exceptions, if so specify
1832 // which function name. Returning to a Java frame should implicitly clear the
1833 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1834 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1835 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1836 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1837 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1838 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1839 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1840
1841 // For deadlock detection
1842 int depth_first_number() { return _depth_first_number; }
1843 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1844
1845 private:
1846 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1847
1848 public:
1849 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1850 void add_monitor_chunk(MonitorChunk* chunk);
1851 void remove_monitor_chunk(MonitorChunk* chunk);
1852 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1853 void inc_in_deopt_handler() { _in_deopt_handler++; }
1854 void dec_in_deopt_handler() {
1855 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1856 if (_in_deopt_handler > 0) { // robustness
1857 _in_deopt_handler--;
1858 }
1859 }
1860
1861 private:
1862 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1863
1864 public:
1865
1866 // Frame iteration; calls the function f for all frames on the stack
1867 void frames_do(void f(frame*, const RegisterMap*));
1868
1869 // Memory operations
1870 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1871
1872 // Sweeper operations
1873 virtual void nmethods_do(CodeBlobClosure* cf);
1874
1875 // RedefineClasses Support
1876 void metadata_do(MetadataClosure* f);
1877
1878 // Debug method asserting thread states are correct during a handshake operation.
1879 DEBUG_ONLY(void verify_states_for_handshake();)
1880
1881 // Misc. operations
1882 char* name() const { return (char*)get_thread_name(); }
1883 void print_on(outputStream* st, bool print_extended_info) const;
1884 void print_on(outputStream* st) const { print_on(st, false); }
1885 void print_value();
1886 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1887 void print_thread_state() const PRODUCT_RETURN;
1888 void print_on_error(outputStream* st, char* buf, int buflen) const;
1889 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1890 void verify();
1891 const char* get_thread_name() const;
1892 protected:
1893 // factor out low-level mechanics for use in both normal and error cases
1894 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1895 public:
1896 const char* get_threadgroup_name() const;
1897 const char* get_parent_name() const;
1898
1899 // Accessing frames
1900 frame last_frame() {
1901 _anchor.make_walkable(this);
1902 return pd_last_frame();
1903 }
1904 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1905
1906 // Returns method at 'depth' java or native frames down the stack
1907 // Used for security checks
1908 Klass* security_get_caller_class(int depth);
1909
1910 // Print stack trace in external format
1911 void print_stack_on(outputStream* st);
1912 void print_stack() { print_stack_on(tty); }
1913
1914 // Print stack traces in various internal formats
1915 void trace_stack() PRODUCT_RETURN;
1916 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1917 void trace_frames() PRODUCT_RETURN;
1918 void trace_oops() PRODUCT_RETURN;
1919
1920 // Print an annotated view of the stack frames
1921 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1922 void validate_frame_layout() {
1923 print_frame_layout(0, true);
1924 }
1925
1926 // Returns the number of stack frames on the stack
1927 int depth() const;
1928
1929 // Function for testing deoptimization
1930 void deoptimize();
1931 void make_zombies();
1932
1933 void deoptimized_wrt_marked_nmethods();
1934
1935 public:
1936 // Returns the running thread as a JavaThread
1937 static inline JavaThread* current();
1938
1939 // Returns the active Java thread. Do not use this if you know you are calling
1940 // from a JavaThread, as it's slower than JavaThread::current. If called from
1941 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1942 // operation. You may not want that either.
1943 static JavaThread* active();
1944
1945 inline CompilerThread* as_CompilerThread();
1946
1947 protected:
1948 virtual void pre_run();
1949 virtual void run();
1950 void thread_main_inner();
1951 virtual void post_run();
1952
1953
1954 private:
1955 GrowableArray<oop>* _array_for_gc;
1956 public:
1957
1958 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1959
1960 public:
1961 // Thread local information maintained by JVMTI.
1962 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1963 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1964 // getter is used to get this JavaThread's JvmtiThreadState if it has
1965 // one which means NULL can be returned. JvmtiThreadState::state_for()
1966 // is used to get the specified JavaThread's JvmtiThreadState if it has
1967 // one or it allocates a new JvmtiThreadState for the JavaThread and
1968 // returns it. JvmtiThreadState::state_for() will return NULL only if
1969 // the specified JavaThread is exiting.
1970 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1971 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1972
1973 // JVMTI PopFrame support
1974 // Setting and clearing popframe_condition
1975 // All of these enumerated values are bits. popframe_pending
1976 // indicates that a PopFrame() has been requested and not yet been
1977 // completed. popframe_processing indicates that that PopFrame() is in
1978 // the process of being completed. popframe_force_deopt_reexecution_bit
1979 // indicates that special handling is required when returning to a
1980 // deoptimized caller.
1981 enum PopCondition {
1982 popframe_inactive = 0x00,
1983 popframe_pending_bit = 0x01,
1984 popframe_processing_bit = 0x02,
1985 popframe_force_deopt_reexecution_bit = 0x04
1986 };
1987 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1988 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1989 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1990 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1991 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1992 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1993 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1994 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1995 #ifdef CC_INTERP
1996 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1997 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1998 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1999 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
2000 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
2001 #endif
2002
2003 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
2004 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
2005 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
2006
2007 private:
2008 // Saved incoming arguments to popped frame.
2009 // Used only when popped interpreted frame returns to deoptimized frame.
2010 void* _popframe_preserved_args;
2011 int _popframe_preserved_args_size;
2012
2013 public:
2014 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2015 void* popframe_preserved_args();
2016 ByteSize popframe_preserved_args_size();
2017 WordSize popframe_preserved_args_size_in_words();
2018 void popframe_free_preserved_args();
2019
2020
2021 private:
2022 JvmtiThreadState *_jvmti_thread_state;
2023
2024 // Used by the interpreter in fullspeed mode for frame pop, method
2025 // entry, method exit and single stepping support. This field is
2026 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
2027 // It can be set to zero asynchronously (i.e., without a VM operation
2028 // or a lock) so we have to be very careful.
2029 int _interp_only_mode;
2030
2031 public:
2032 // used by the interpreter for fullspeed debugging support (see above)
2033 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2034 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2035 int get_interp_only_mode() { return _interp_only_mode; }
2036 void increment_interp_only_mode() { ++_interp_only_mode; }
2037 void decrement_interp_only_mode() { --_interp_only_mode; }
2038
2039 // support for cached flag that indicates whether exceptions need to be posted for this thread
2040 // if this is false, we can avoid deoptimizing when events are thrown
2041 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2042 private:
2043 int _should_post_on_exceptions_flag;
2044
2045 public:
2046 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2047 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2048
2049 private:
2050 ThreadStatistics *_thread_stat;
2051
2052 public:
2053 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2054
2055 // Return a blocker object for which this thread is blocked parking.
2056 oop current_park_blocker();
2057
2058 private:
2059 static size_t _stack_size_at_create;
2060
2061 public:
2062 static inline size_t stack_size_at_create(void) {
2063 return _stack_size_at_create;
2064 }
2065 static inline void set_stack_size_at_create(size_t value) {
2066 _stack_size_at_create = value;
2067 }
2068
2069 // Machine dependent stuff
2070 #include OS_CPU_HEADER(thread)
2071
2072 public:
2073 void set_blocked_on_compilation(bool value) {
2074 _blocked_on_compilation = value;
2075 }
2076
2077 bool blocked_on_compilation() {
2078 return _blocked_on_compilation;
2079 }
2080 protected:
2081 bool _blocked_on_compilation;
2082
2083
2084 // JSR166 per-thread parker
2085 private:
2086 Parker* _parker;
2087 public:
2088 Parker* parker() { return _parker; }
2089
2090 // Biased locking support
2091 private:
2092 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2093 public:
2094 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2095 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2096
2097 // clearing/querying jni attach status
2098 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2099 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2100 inline void set_done_attaching_via_jni();
2101
2102 // Stack dump assistance:
2103 // Track the class we want to initialize but for which we have to wait
2104 // on its init_lock() because it is already being initialized.
2105 void set_class_to_be_initialized(InstanceKlass* k);
2106 InstanceKlass* class_to_be_initialized() const;
2107
2108 private:
2109 InstanceKlass* _class_to_be_initialized;
2110
2111 };
2112
2113 // Inline implementation of JavaThread::current
2114 inline JavaThread* JavaThread::current() {
2115 Thread* thread = Thread::current();
2116 assert(thread->is_Java_thread(), "just checking");
2117 return (JavaThread*)thread;
2118 }
2119
2120 inline CompilerThread* JavaThread::as_CompilerThread() {
2121 assert(is_Compiler_thread(), "just checking");
2122 return (CompilerThread*)this;
2123 }
2124
2125 // Dedicated thread to sweep the code cache
2126 class CodeCacheSweeperThread : public JavaThread {
2127 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2128 public:
2129 CodeCacheSweeperThread();
2130 // Track the nmethod currently being scanned by the sweeper
2131 void set_scanned_compiled_method(CompiledMethod* cm) {
2132 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2133 _scanned_compiled_method = cm;
2134 }
2135
2136 // Hide sweeper thread from external view.
2137 bool is_hidden_from_external_view() const { return true; }
2138
2139 bool is_Code_cache_sweeper_thread() const { return true; }
2140
2141 // Prevent GC from unloading _scanned_compiled_method
2142 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2143 void nmethods_do(CodeBlobClosure* cf);
2144 };
2145
2146 // A thread used for Compilation.
2147 class CompilerThread : public JavaThread {
2148 friend class VMStructs;
2149 private:
2150 CompilerCounters* _counters;
2151
2152 ciEnv* _env;
2153 CompileLog* _log;
2154 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2155 CompileQueue* _queue;
2156 BufferBlob* _buffer_blob;
2157
2158 AbstractCompiler* _compiler;
2159 TimeStamp _idle_time;
2160
2161 public:
2162
2163 static CompilerThread* current();
2164
2165 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2166 ~CompilerThread();
2167
2168 bool is_Compiler_thread() const { return true; }
2169
2170 virtual bool can_call_java() const;
2171
2172 // Hide native compiler threads from external view.
2173 bool is_hidden_from_external_view() const { return !can_call_java(); }
2174
2175 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2176 AbstractCompiler* compiler() const { return _compiler; }
2177
2178 CompileQueue* queue() const { return _queue; }
2179 CompilerCounters* counters() const { return _counters; }
2180
2181 // Get/set the thread's compilation environment.
2182 ciEnv* env() { return _env; }
2183 void set_env(ciEnv* env) { _env = env; }
2184
2185 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2186 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2187
2188 // Get/set the thread's logging information
2189 CompileLog* log() { return _log; }
2190 void init_log(CompileLog* log) {
2191 // Set once, for good.
2192 assert(_log == NULL, "set only once");
2193 _log = log;
2194 }
2195
2196 void start_idle_timer() { _idle_time.update(); }
2197 jlong idle_time_millis() {
2198 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2199 }
2200
2201 #ifndef PRODUCT
2202 private:
2203 IdealGraphPrinter *_ideal_graph_printer;
2204 public:
2205 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2206 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2207 #endif
2208
2209 // Get/set the thread's current task
2210 CompileTask* task() { return _task; }
2211 void set_task(CompileTask* task) { _task = task; }
2212 };
2213
2214 inline CompilerThread* CompilerThread::current() {
2215 return JavaThread::current()->as_CompilerThread();
2216 }
2217
2218 // The active thread queue. It also keeps track of the current used
2219 // thread priorities.
2220 class Threads: AllStatic {
2221 friend class VMStructs;
2222 private:
2223 static JavaThread* _thread_list;
2224 static int _number_of_threads;
2225 static int _number_of_non_daemon_threads;
2226 static int _return_code;
2227 static uintx _thread_claim_token;
2228 #ifdef ASSERT
2229 static bool _vm_complete;
2230 #endif
2231
2232 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2233 static void initialize_jsr292_core_classes(TRAPS);
2234
2235 public:
2236 // Thread management
2237 // force_daemon is a concession to JNI, where we may need to add a
2238 // thread to the thread list before allocating its thread object
2239 static void add(JavaThread* p, bool force_daemon = false);
2240 static void remove(JavaThread* p, bool is_daemon);
2241 static void non_java_threads_do(ThreadClosure* tc);
2242 static void java_threads_do(ThreadClosure* tc);
2243 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2244 static void threads_do(ThreadClosure* tc);
2245 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2246
2247 // Initializes the vm and creates the vm thread
2248 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2249 static void convert_vm_init_libraries_to_agents();
2250 static void create_vm_init_libraries();
2251 static void create_vm_init_agents();
2252 static void shutdown_vm_agents();
2253 static bool destroy_vm();
2254 // Supported VM versions via JNI
2255 // Includes JNI_VERSION_1_1
2256 static jboolean is_supported_jni_version_including_1_1(jint version);
2257 // Does not include JNI_VERSION_1_1
2258 static jboolean is_supported_jni_version(jint version);
2259
2260 // The "thread claim token" provides a way for threads to be claimed
2261 // by parallel worker tasks.
2262 //
2263 // Each thread contains a "token" field. A task will claim the
2264 // thread only if its token is different from the global token,
2265 // which is updated by calling change_thread_claim_token(). When
2266 // a thread is claimed, it's token is set to the global token value
2267 // so other threads in the same iteration pass won't claim it.
2268 //
2269 // For this to work change_thread_claim_token() needs to be called
2270 // exactly once in sequential code before starting parallel tasks
2271 // that should claim threads.
2272 //
2273 // New threads get their token set to 0 and change_thread_claim_token()
2274 // never sets the global token to 0.
2275 static uintx thread_claim_token() { return _thread_claim_token; }
2276 static void change_thread_claim_token();
2277 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2278
2279 // Apply "f->do_oop" to all root oops in all threads.
2280 // This version may only be called by sequential code.
2281 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2282 // This version may be called by sequential or parallel code.
2283 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2284
2285 // Apply "f->do_oop" to roots in all threads that
2286 // are part of compiled frames
2287 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2288
2289 static void convert_hcode_pointers();
2290 static void restore_hcode_pointers();
2291
2292 // Sweeper
2293 static void nmethods_do(CodeBlobClosure* cf);
2294
2295 // RedefineClasses support
2296 static void metadata_do(MetadataClosure* f);
2297 static void metadata_handles_do(void f(Metadata*));
2298
2299 #ifdef ASSERT
2300 static bool is_vm_complete() { return _vm_complete; }
2301 #endif // ASSERT
2302
2303 // Verification
2304 static void verify();
2305 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2306 static void print(bool print_stacks, bool internal_format) {
2307 // this function is only used by debug.cpp
2308 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2309 }
2310 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2311 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2312 int buflen, bool* found_current);
2313 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2314
2315 // Get Java threads that are waiting to enter a monitor.
2316 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2317 int count, address monitor);
2318
2319 // Get owning Java thread from the monitor's owner field.
2320 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2321 address owner);
2322
2323 // Number of threads on the active threads list
2324 static int number_of_threads() { return _number_of_threads; }
2325 // Number of non-daemon threads on the active threads list
2326 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2327
2328 // Deoptimizes all frames tied to marked nmethods
2329 static void deoptimized_wrt_marked_nmethods();
2330
2331 struct Test; // For private gtest access.
2332 };
2333
2334
2335 // Thread iterator
2336 class ThreadClosure: public StackObj {
2337 public:
2338 virtual void do_thread(Thread* thread) = 0;
2339 };
2340
2341 class SignalHandlerMark: public StackObj {
2342 private:
2343 Thread* _thread;
2344 public:
2345 SignalHandlerMark(Thread* t) {
2346 _thread = t;
2347 if (_thread) _thread->enter_signal_handler();
2348 }
2349 ~SignalHandlerMark() {
2350 if (_thread) _thread->leave_signal_handler();
2351 _thread = NULL;
2352 }
2353 };
2354
2355
2356 #endif // SHARE_RUNTIME_THREAD_HPP