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 ThreadClosure;
87 class ICRefillVerifier;
88 class IdealGraphPrinter;
89
90 class JVMCIEnv;
91 class JVMCIPrimitiveArray;
92
93 class Metadata;
94 class ResourceArea;
95
96 DEBUG_ONLY(class ResourceMark;)
97
98 class WorkerThread;
99
100 // Class hierarchy
101 // - Thread
102 // - JavaThread
103 // - various subclasses eg CompilerThread, ServiceThread
104 // - NonJavaThread
105 // - NamedThread
106 // - VMThread
107 // - ConcurrentGCThread
108 // - WorkerThread
109 // - GangWorker
110 // - WatcherThread
111 // - JfrThreadSampler
112 //
113 // All Thread subclasses must be either JavaThread or NonJavaThread.
114 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
115 // a partially constructed/destroyed Thread.
116
117 // Thread execution sequence and actions:
118 // All threads:
119 // - thread_native_entry // per-OS native entry point
120 // - stack initialization
121 // - other OS-level initialization (signal masks etc)
122 // - handshake with creating thread (if not started suspended)
123 // - this->call_run() // common shared entry point
124 // - shared common initialization
125 // - this->pre_run() // virtual per-thread-type initialization
126 // - this->run() // virtual per-thread-type "main" logic
127 // - shared common tear-down
128 // - this->post_run() // virtual per-thread-type tear-down
129 // - // 'this' no longer referenceable
130 // - OS-level tear-down (minimal)
131 // - final logging
132 //
133 // For JavaThread:
134 // - this->run() // virtual but not normally overridden
135 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
136 // - this->entry_point() // set differently for each kind of JavaThread
137
138 class Thread: public ThreadShadow {
139 friend class VMStructs;
140 friend class JVMCIVMStructs;
141 private:
142
143 #ifndef USE_LIBRARY_BASED_TLS_ONLY
144 // Current thread is maintained as a thread-local variable
145 static THREAD_LOCAL_DECL Thread* _thr_current;
146 #endif
147
148 // Thread local data area available to the GC. The internal
149 // structure and contents of this data area is GC-specific.
150 // Only GC and GC barrier code should access this data area.
151 GCThreadLocalData _gc_data;
152
153 public:
154 static ByteSize gc_data_offset() {
155 return byte_offset_of(Thread, _gc_data);
156 }
157
158 template <typename T> T* gc_data() {
159 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
160 return reinterpret_cast<T*>(&_gc_data);
161 }
162
163 // Exception handling
164 // (Note: _pending_exception and friends are in ThreadShadow)
165 //oop _pending_exception; // pending exception for current thread
166 // const char* _exception_file; // file information for exception (debugging only)
167 // int _exception_line; // line information for exception (debugging only)
168 protected:
169
170 DEBUG_ONLY(static Thread* _starting_thread;)
171
172 // Support for forcing alignment of thread objects for biased locking
173 void* _real_malloc_address;
174
175 // JavaThread lifecycle support:
176 friend class SafeThreadsListPtr; // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
177 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
178 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
179 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
180 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
181
182 ThreadsList* volatile _threads_hazard_ptr;
183 SafeThreadsListPtr* _threads_list_ptr;
184 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
185 ThreadsList* get_threads_hazard_ptr();
186 void set_threads_hazard_ptr(ThreadsList* new_list);
187 static bool is_hazard_ptr_tagged(ThreadsList* list) {
188 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
189 }
190 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
191 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
192 }
193 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
194 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
195 }
196 // This field is enabled via -XX:+EnableThreadSMRStatistics:
197 uint _nested_threads_hazard_ptr_cnt;
198 void dec_nested_threads_hazard_ptr_cnt() {
199 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
200 _nested_threads_hazard_ptr_cnt--;
201 }
202 void inc_nested_threads_hazard_ptr_cnt() {
203 _nested_threads_hazard_ptr_cnt++;
204 }
205 uint nested_threads_hazard_ptr_cnt() {
206 return _nested_threads_hazard_ptr_cnt;
207 }
208
209 public:
210 void* operator new(size_t size) throw() { return allocate(size, true); }
211 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
212 return allocate(size, false); }
213 void operator delete(void* p);
214
215 protected:
216 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
217 private:
218
219 // ***************************************************************
220 // Suspend and resume support
221 // ***************************************************************
222 //
223 // VM suspend/resume no longer exists - it was once used for various
224 // things including safepoints but was deprecated and finally removed
225 // in Java 7. Because VM suspension was considered "internal" Java-level
226 // suspension was considered "external", and this legacy naming scheme
227 // remains.
228 //
229 // External suspend/resume requests come from JVM_SuspendThread,
230 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
231 // ResumeThread. External
232 // suspend requests cause _external_suspend to be set and external
233 // resume requests cause _external_suspend to be cleared.
234 // External suspend requests do not nest on top of other external
235 // suspend requests. The higher level APIs reject suspend requests
236 // for already suspended threads.
237 //
238 // The external_suspend
239 // flag is checked by has_special_runtime_exit_condition() and java thread
240 // will self-suspend when handle_special_runtime_exit_condition() is
241 // called. Most uses of the _thread_blocked state in JavaThreads are
242 // considered the same as being externally suspended; if the blocking
243 // condition lifts, the JavaThread will self-suspend. Other places
244 // where VM checks for external_suspend include:
245 // + mutex granting (do not enter monitors when thread is suspended)
246 // + state transitions from _thread_in_native
247 //
248 // In general, java_suspend() does not wait for an external suspend
249 // request to complete. When it returns, the only guarantee is that
250 // the _external_suspend field is true.
251 //
252 // wait_for_ext_suspend_completion() is used to wait for an external
253 // suspend request to complete. External suspend requests are usually
254 // followed by some other interface call that requires the thread to
255 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
256 // the interface that requires quiescence, we give the JavaThread a
257 // chance to self-suspend before we need it to be quiescent. This
258 // improves overall suspend/query performance.
259 //
260 // _suspend_flags controls the behavior of java_ suspend/resume.
261 // It must be set under the protection of SR_lock. Read from the flag is
262 // OK without SR_lock as long as the value is only used as a hint.
263 // (e.g., check _external_suspend first without lock and then recheck
264 // inside SR_lock and finish the suspension)
265 //
266 // _suspend_flags is also overloaded for other "special conditions" so
267 // that a single check indicates whether any special action is needed
268 // eg. for async exceptions.
269 // -------------------------------------------------------------------
270 // Notes:
271 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
272 // but we still update its value to keep other part of the system (mainly
273 // JVMTI) happy. ThreadState is legacy code (see notes in
274 // osThread.hpp).
275 //
276 // 2. It would be more natural if set_external_suspend() is private and
277 // part of java_suspend(), but that probably would affect the suspend/query
278 // performance. Need more investigation on this.
279
280 // suspend/resume lock: used for self-suspend
281 Monitor* _SR_lock;
282
283 protected:
284 enum SuspendFlags {
285 // NOTE: avoid using the sign-bit as cc generates different test code
286 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
287
288 _external_suspend = 0x20000000U, // thread is asked to self suspend
289 _ext_suspended = 0x40000000U, // thread has self-suspended
290
291 _has_async_exception = 0x00000001U, // there is a pending async exception
292 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
293
294 _trace_flag = 0x00000004U, // call tracing backend
295 _ea_obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent
296 };
297
298 // various suspension related flags - atomically updated
299 // overloaded for async exception checking in check_special_condition_for_native_trans.
300 volatile uint32_t _suspend_flags;
301
302 private:
303 int _num_nested_signal;
304
305 DEBUG_ONLY(bool _suspendible_thread;)
306
307 public:
308 void enter_signal_handler() { _num_nested_signal++; }
309 void leave_signal_handler() { _num_nested_signal--; }
310 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
311
312 // Determines if a heap allocation failure will be retried
313 // (e.g., by deoptimizing and re-executing in the interpreter).
314 // In this case, the failed allocation must raise
315 // Universe::out_of_memory_error_retry() and omit side effects
316 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
317 // and -XX:OnOutOfMemoryError.
318 virtual bool in_retryable_allocation() const { return false; }
319
320 #ifdef ASSERT
321 void set_suspendible_thread() {
322 _suspendible_thread = true;
323 }
324
325 void clear_suspendible_thread() {
326 _suspendible_thread = false;
327 }
328
329 bool is_suspendible_thread() { return _suspendible_thread; }
330 #endif
331
332 private:
333 // Active_handles points to a block of handles
334 JNIHandleBlock* _active_handles;
335
336 // One-element thread local free list
337 JNIHandleBlock* _free_handle_block;
338
339 // Point to the last handle mark
340 HandleMark* _last_handle_mark;
341
342 // Claim value for parallel iteration over threads.
343 uintx _threads_do_token;
344
345 // Support for GlobalCounter
346 private:
347 volatile uintx _rcu_counter;
348 public:
349 volatile uintx* get_rcu_counter() {
350 return &_rcu_counter;
351 }
352
353 public:
354 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
355 HandleMark* last_handle_mark() const { return _last_handle_mark; }
356 private:
357
358 #ifdef ASSERT
359 ICRefillVerifier* _missed_ic_stub_refill_verifier;
360
361 public:
362 ICRefillVerifier* missed_ic_stub_refill_verifier() {
363 return _missed_ic_stub_refill_verifier;
364 }
365
366 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
367 _missed_ic_stub_refill_verifier = verifier;
368 }
369 #endif // ASSERT
370
371 private:
372
373 // Debug support for checking if code allows safepoints or not.
374 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
375 // mutex, or blocking on an object synchronizer (Java locking).
376 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
377 // the above cases.
378 //
379 // The class NoSafepointVerifier is used to set this counter.
380 //
381 NOT_PRODUCT(int _no_safepoint_count;) // If 0, thread allow a safepoint to happen
382
383 private:
384 // Used by SkipGCALot class.
385 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
386
387 friend class GCLocker;
388 friend class NoSafepointVerifier;
389 friend class PauseNoSafepointVerifier;
390
391 volatile void* _polling_page; // Thread local polling page
392
393 ThreadLocalAllocBuffer _tlab; // Thread-local eden
394 jlong _allocated_bytes; // Cumulative number of bytes allocated on
395 // the Java heap
396 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
397
398 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
399
400 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
401
402 int _vm_operation_started_count; // VM_Operation support
403 int _vm_operation_completed_count; // VM_Operation support
404
405 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
406 // is waiting to lock
407 bool _current_pending_monitor_is_from_java; // locking is from Java code
408
409 // ObjectMonitor on which this thread called Object.wait()
410 ObjectMonitor* _current_waiting_monitor;
411
412 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
413 public:
414 ObjectMonitor* omFreeList;
415 int omFreeCount; // length of omFreeList
416 int omFreeProvision; // reload chunk size
417 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
418 int omInUseCount; // length of omInUseList
419
420 #ifdef ASSERT
421 private:
422 volatile uint64_t _visited_for_critical_count;
423
424 public:
425 void set_visited_for_critical_count(uint64_t safepoint_id) {
426 assert(_visited_for_critical_count == 0, "Must be reset before set");
427 assert((safepoint_id & 0x1) == 1, "Must be odd");
428 _visited_for_critical_count = safepoint_id;
429 }
430 void reset_visited_for_critical_count(uint64_t safepoint_id) {
431 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
432 _visited_for_critical_count = 0;
433 }
434 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
435 return _visited_for_critical_count == safepoint_id;
436 }
437 #endif
438
439 public:
440 enum {
441 is_definitely_current_thread = true
442 };
443
444 // Constructor
445 Thread();
446 virtual ~Thread() = 0; // Thread is abstract.
447
448 // Manage Thread::current()
449 void initialize_thread_current();
450 static void clear_thread_current(); // TLS cleanup needed before threads terminate
451
452 protected:
453 // To be implemented by children.
454 virtual void run() = 0;
455 virtual void pre_run() = 0;
456 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
457
458 #ifdef ASSERT
459 enum RunState {
460 PRE_CALL_RUN,
461 CALL_RUN,
462 PRE_RUN,
463 RUN,
464 POST_RUN
465 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
466 };
467 RunState _run_state; // for lifecycle checks
468 #endif
469
470
471 public:
472 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
473 void call_run();
474
475 // Testers
476 virtual bool is_VM_thread() const { return false; }
477 virtual bool is_Java_thread() const { return false; }
478 virtual bool is_Compiler_thread() const { return false; }
479 virtual bool is_Code_cache_sweeper_thread() const { return false; }
480 virtual bool is_hidden_from_external_view() const { return false; }
481 virtual bool is_jvmti_agent_thread() const { return false; }
482 // True iff the thread can perform GC operations at a safepoint.
483 // Generally will be true only of VM thread and parallel GC WorkGang
484 // threads.
485 virtual bool is_GC_task_thread() const { return false; }
486 virtual bool is_Watcher_thread() const { return false; }
487 virtual bool is_ConcurrentGC_thread() const { return false; }
488 virtual bool is_Named_thread() const { return false; }
489 virtual bool is_Worker_thread() const { return false; }
490
491 // Can this thread make Java upcalls
492 virtual bool can_call_java() const { return false; }
493
494 // Is this a JavaThread that is on the VM's current ThreadsList?
495 // If so it must participate in the safepoint protocol.
496 virtual bool is_active_Java_thread() const { return false; }
497
498 // Casts
499 virtual WorkerThread* as_Worker_thread() const { return NULL; }
500
501 virtual char* name() const { return (char*)"Unknown thread"; }
502
503 // Returns the current thread (ASSERTS if NULL)
504 static inline Thread* current();
505 // Returns the current thread, or NULL if not attached
506 static inline Thread* current_or_null();
507 // Returns the current thread, or NULL if not attached, and is
508 // safe for use from signal-handlers
509 static inline Thread* current_or_null_safe();
510
511 // Common thread operations
512 #ifdef ASSERT
513 static void check_for_dangling_thread_pointer(Thread *thread);
514 #endif
515 static void set_priority(Thread* thread, ThreadPriority priority);
516 static ThreadPriority get_priority(const Thread* const thread);
517 static void start(Thread* thread);
518 static void interrupt(Thread* thr);
519 static bool is_interrupted(Thread* thr, bool clear_interrupted);
520
521 void set_native_thread_name(const char *name) {
522 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
523 os::set_native_thread_name(name);
524 }
525
526 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
527 Monitor* SR_lock() const { return _SR_lock; }
528
529 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
530
531 inline void set_suspend_flag(SuspendFlags f);
532 inline void clear_suspend_flag(SuspendFlags f);
533
534 inline void set_has_async_exception();
535 inline void clear_has_async_exception();
536
537 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
538
539 inline void set_critical_native_unlock();
540 inline void clear_critical_native_unlock();
541
542 inline void set_trace_flag();
543 inline void clear_trace_flag();
544
545 inline void set_ea_obj_deopt_flag();
546 inline void clear_ea_obj_deopt_flag();
547
548 // Support for Unhandled Oop detection
549 // Add the field for both, fastdebug and debug, builds to keep
550 // Thread's fields layout the same.
551 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
552 #ifdef CHECK_UNHANDLED_OOPS
553 private:
554 UnhandledOops* _unhandled_oops;
555 #elif defined(ASSERT)
556 private:
557 void* _unhandled_oops;
558 #endif
559 #ifdef CHECK_UNHANDLED_OOPS
560 public:
561 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
562 // Mark oop safe for gc. It may be stack allocated but won't move.
563 void allow_unhandled_oop(oop *op) {
564 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
565 }
566 // Clear oops at safepoint so crashes point to unhandled oop violator
567 void clear_unhandled_oops() {
568 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
569 }
570 #endif // CHECK_UNHANDLED_OOPS
571
572 public:
573 #ifndef PRODUCT
574 bool skip_gcalot() { return _skip_gcalot; }
575 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
576 #endif
577
578 // Installs a pending exception to be inserted later
579 static void send_async_exception(oop thread_oop, oop java_throwable);
580
581 // Resource area
582 ResourceArea* resource_area() const { return _resource_area; }
583 void set_resource_area(ResourceArea* area) { _resource_area = area; }
584
585 OSThread* osthread() const { return _osthread; }
586 void set_osthread(OSThread* thread) { _osthread = thread; }
587
588 // JNI handle support
589 JNIHandleBlock* active_handles() const { return _active_handles; }
590 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
591 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
592 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
593
594 // Internal handle support
595 HandleArea* handle_area() const { return _handle_area; }
596 void set_handle_area(HandleArea* area) { _handle_area = area; }
597
598 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
599 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
600
601 // Thread-Local Allocation Buffer (TLAB) support
602 ThreadLocalAllocBuffer& tlab() { return _tlab; }
603 void initialize_tlab() {
604 if (UseTLAB) {
605 tlab().initialize();
606 }
607 }
608
609 jlong allocated_bytes() { return _allocated_bytes; }
610 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
611 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
612 inline jlong cooked_allocated_bytes();
613
614 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
615
616 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
617
618 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
619
620 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
621
622 bool is_ea_obj_deopt_suspend() { return (_suspend_flags & _ea_obj_deopt) != 0; }
623
624 // VM operation support
625 int vm_operation_ticket() { return ++_vm_operation_started_count; }
626 int vm_operation_completed_count() { return _vm_operation_completed_count; }
627 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
628
629 // For tracking the heavyweight monitor the thread is pending on.
630 ObjectMonitor* current_pending_monitor() {
631 return _current_pending_monitor;
632 }
633 void set_current_pending_monitor(ObjectMonitor* monitor) {
634 _current_pending_monitor = monitor;
635 }
636 void set_current_pending_monitor_is_from_java(bool from_java) {
637 _current_pending_monitor_is_from_java = from_java;
638 }
639 bool current_pending_monitor_is_from_java() {
640 return _current_pending_monitor_is_from_java;
641 }
642
643 // For tracking the ObjectMonitor on which this thread called Object.wait()
644 ObjectMonitor* current_waiting_monitor() {
645 return _current_waiting_monitor;
646 }
647 void set_current_waiting_monitor(ObjectMonitor* monitor) {
648 _current_waiting_monitor = monitor;
649 }
650
651 // GC support
652 // Apply "f->do_oop" to all root oops in "this".
653 // Used by JavaThread::oops_do.
654 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
655 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
656
657 // Handles the parallel case for claim_threads_do.
658 private:
659 bool claim_par_threads_do(uintx claim_token);
660 public:
661 // Requires that "claim_token" is that of the current iteration.
662 // If "is_par" is false, sets the token of "this" to
663 // "claim_token", and returns "true". If "is_par" is true,
664 // uses an atomic instruction to set the current thread's token to
665 // "claim_token", if it is not already. Returns "true" iff the
666 // calling thread does the update, this indicates that the calling thread
667 // has claimed the thread in the current iteration.
668 bool claim_threads_do(bool is_par, uintx claim_token) {
669 if (!is_par) {
670 _threads_do_token = claim_token;
671 return true;
672 } else {
673 return claim_par_threads_do(claim_token);
674 }
675 }
676
677 uintx threads_do_token() const { return _threads_do_token; }
678
679 // jvmtiRedefineClasses support
680 void metadata_handles_do(void f(Metadata*));
681
682 // Used by fast lock support
683 virtual bool is_lock_owned(address adr) const;
684
685 // Check if address is in the stack of the thread (not just for locks).
686 // Warning: the method can only be used on the running thread
687 bool is_in_stack(address adr) const;
688 // Check if address is in the usable part of the stack (excludes protected
689 // guard pages)
690 bool is_in_usable_stack(address adr) const;
691
692 // Sets this thread as starting thread. Returns failure if thread
693 // creation fails due to lack of memory, too many threads etc.
694 bool set_as_starting_thread();
695
696 protected:
697 // OS data associated with the thread
698 OSThread* _osthread; // Platform-specific thread information
699
700 // Thread local resource area for temporary allocation within the VM
701 ResourceArea* _resource_area;
702
703 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
704
705 // Thread local handle area for allocation of handles within the VM
706 HandleArea* _handle_area;
707 GrowableArray<Metadata*>* _metadata_handles;
708
709 // Support for stack overflow handling, get_thread, etc.
710 address _stack_base;
711 size_t _stack_size;
712 int _lgrp_id;
713
714 volatile void** polling_page_addr() { return &_polling_page; }
715
716 public:
717 // Stack overflow support
718 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
719 void set_stack_base(address base) { _stack_base = base; }
720 size_t stack_size() const { return _stack_size; }
721 void set_stack_size(size_t size) { _stack_size = size; }
722 address stack_end() const { return stack_base() - stack_size(); }
723 void record_stack_base_and_size();
724 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
725
726 bool on_local_stack(address adr) const {
727 // QQQ this has knowledge of direction, ought to be a stack method
728 return (_stack_base >= adr && adr >= stack_end());
729 }
730
731 int lgrp_id() const { return _lgrp_id; }
732 void set_lgrp_id(int value) { _lgrp_id = value; }
733
734 // Printing
735 void print_on(outputStream* st, bool print_extended_info) const;
736 virtual void print_on(outputStream* st) const { print_on(st, false); }
737 void print() const;
738 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
739 void print_value_on(outputStream* st) const;
740
741 // Debug-only code
742 #ifdef ASSERT
743 private:
744 // Deadlock detection support for Mutex locks. List of locks own by thread.
745 Mutex* _owned_locks;
746 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
747 // thus the friendship
748 friend class Mutex;
749 friend class Monitor;
750
751 public:
752 void print_owned_locks_on(outputStream* st) const;
753 void print_owned_locks() const { print_owned_locks_on(tty); }
754 Mutex* owned_locks() const { return _owned_locks; }
755 bool owns_locks() const { return owned_locks() != NULL; }
756
757 // Deadlock detection
758 ResourceMark* current_resource_mark() { return _current_resource_mark; }
759 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
760 #endif // ASSERT
761
762 // These functions check conditions on a JavaThread before possibly going to a safepoint,
763 // including NoSafepointVerifier.
764 void check_for_valid_safepoint_state(bool potential_vm_operation) NOT_DEBUG_RETURN;
765 void check_possible_safepoint() NOT_DEBUG_RETURN;
766
767 private:
768 volatile int _jvmti_env_iteration_count;
769
770 public:
771 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
772 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
773 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
774
775 // Code generation
776 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
777 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
778 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
779
780 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
781 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
782
783 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
784
785 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
786 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
787 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
788 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
789
790 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
791
792 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
793
794 public:
795 volatile intptr_t _Stalled;
796 volatile int _TypeTag;
797 ParkEvent * _ParkEvent; // for synchronized()
798 ParkEvent * _SleepEvent; // for Thread.sleep
799 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
800 int NativeSyncRecursion; // diagnostic
801
802 volatile int _OnTrap; // Resume-at IP delta
803 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
804 jint _hashStateX; // thread-specific hashCode generator state
805 jint _hashStateY;
806 jint _hashStateZ;
807
808 // Low-level leaf-lock primitives used to implement synchronization
809 // and native monitor-mutex infrastructure.
810 // Not for general synchronization use.
811 static void SpinAcquire(volatile int * Lock, const char * Name);
812 static void SpinRelease(volatile int * Lock);
813 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
814 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
815 static void muxRelease(volatile intptr_t * Lock);
816 };
817
818 // Inline implementation of Thread::current()
819 inline Thread* Thread::current() {
820 Thread* current = current_or_null();
821 assert(current != NULL, "Thread::current() called on detached thread");
822 return current;
823 }
824
825 inline Thread* Thread::current_or_null() {
826 #ifndef USE_LIBRARY_BASED_TLS_ONLY
827 return _thr_current;
828 #else
829 if (ThreadLocalStorage::is_initialized()) {
830 return ThreadLocalStorage::thread();
831 }
832 return NULL;
833 #endif
834 }
835
836 inline Thread* Thread::current_or_null_safe() {
837 if (ThreadLocalStorage::is_initialized()) {
838 return ThreadLocalStorage::thread();
839 }
840 return NULL;
841 }
842
843 class NonJavaThread: public Thread {
844 friend class VMStructs;
845
846 NonJavaThread* volatile _next;
847
848 class List;
849 static List _the_list;
850
851 void add_to_the_list();
852 void remove_from_the_list();
853
854 protected:
855 virtual void pre_run();
856 virtual void post_run();
857
858 public:
859 NonJavaThread();
860 ~NonJavaThread();
861
862 class Iterator;
863 };
864
865 // Provides iteration over the list of NonJavaThreads.
866 // List addition occurs in pre_run(), and removal occurs in post_run(),
867 // so that only live fully-initialized threads can be found in the list.
868 // Threads created after an iterator is constructed will not be visited
869 // by the iterator. The scope of an iterator is a critical section; there
870 // must be no safepoint checks in that scope.
871 class NonJavaThread::Iterator : public StackObj {
872 uint _protect_enter;
873 NonJavaThread* _current;
874
875 // Noncopyable.
876 Iterator(const Iterator&);
877 Iterator& operator=(const Iterator&);
878
879 public:
880 Iterator();
881 ~Iterator();
882
883 bool end() const { return _current == NULL; }
884 NonJavaThread* current() const { return _current; }
885 void step();
886 };
887
888 // Name support for threads. non-JavaThread subclasses with multiple
889 // uniquely named instances should derive from this.
890 class NamedThread: public NonJavaThread {
891 friend class VMStructs;
892 enum {
893 max_name_len = 64
894 };
895 private:
896 char* _name;
897 // log JavaThread being processed by oops_do
898 JavaThread* _processed_thread;
899 uint _gc_id; // The current GC id when a thread takes part in GC
900
901 public:
902 NamedThread();
903 ~NamedThread();
904 // May only be called once per thread.
905 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
906 virtual bool is_Named_thread() const { return true; }
907 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
908 JavaThread *processed_thread() { return _processed_thread; }
909 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
910 virtual void print_on(outputStream* st) const;
911
912 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
913 uint gc_id() { return _gc_id; }
914 };
915
916 // Worker threads are named and have an id of an assigned work.
917 class WorkerThread: public NamedThread {
918 private:
919 uint _id;
920 public:
921 WorkerThread() : _id(0) { }
922 virtual bool is_Worker_thread() const { return true; }
923
924 virtual WorkerThread* as_Worker_thread() const {
925 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
926 return (WorkerThread*) this;
927 }
928
929 void set_id(uint work_id) { _id = work_id; }
930 uint id() const { return _id; }
931 };
932
933 // A single WatcherThread is used for simulating timer interrupts.
934 class WatcherThread: public NonJavaThread {
935 friend class VMStructs;
936 protected:
937 virtual void run();
938
939 private:
940 static WatcherThread* _watcher_thread;
941
942 static bool _startable;
943 // volatile due to at least one lock-free read
944 volatile static bool _should_terminate;
945 public:
946 enum SomeConstants {
947 delay_interval = 10 // interrupt delay in milliseconds
948 };
949
950 // Constructor
951 WatcherThread();
952
953 // No destruction allowed
954 ~WatcherThread() {
955 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
956 }
957
958 // Tester
959 bool is_Watcher_thread() const { return true; }
960
961 // Printing
962 char* name() const { return (char*)"VM Periodic Task Thread"; }
963 void print_on(outputStream* st) const;
964 void unpark();
965
966 // Returns the single instance of WatcherThread
967 static WatcherThread* watcher_thread() { return _watcher_thread; }
968
969 // Create and start the single instance of WatcherThread, or stop it on shutdown
970 static void start();
971 static void stop();
972 // Only allow start once the VM is sufficiently initialized
973 // Otherwise the first task to enroll will trigger the start
974 static void make_startable();
975 private:
976 int sleep() const;
977 };
978
979
980 class CompilerThread;
981
982 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
983
984 // Holds updates for compiled frames by JVMTI agents that cannot be performed immediately.
985 class JvmtiDeferredUpdates : public CHeapObj<mtCompiler> {
986
987 // Relocking has to be deferred, if the lock owning thread is currently waiting on the monitor.
988 int _relock_count_after_wait;
989
990 // Deferred updates of locals, expressions and monitors
991 GrowableArray<jvmtiDeferredLocalVariableSet*> _deferred_locals_updates;
992
993 public:
994 JvmtiDeferredUpdates() :
995 _relock_count_after_wait(0),
996 _deferred_locals_updates((ResourceObj::set_allocation_type((address) &_deferred_locals_updates,
997 ResourceObj::C_HEAP), 1), true, mtCompiler) { }
998
999 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() { return &_deferred_locals_updates; }
1000
1001 int get_and_reset_relock_count_after_wait() {
1002 int result = _relock_count_after_wait;
1003 _relock_count_after_wait = 0;
1004 return result;
1005 }
1006 void inc_relock_count_after_wait() {
1007 _relock_count_after_wait++;
1008 }
1009 };
1010
1011
1012 class JavaThread: public Thread {
1013 friend class VMStructs;
1014 friend class JVMCIVMStructs;
1015 friend class WhiteBox;
1016 private:
1017 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
1018 oop _threadObj; // The Java level thread object
1019
1020 #ifdef ASSERT
1021 private:
1022 int _java_call_counter;
1023
1024 public:
1025 int java_call_counter() { return _java_call_counter; }
1026 void inc_java_call_counter() { _java_call_counter++; }
1027 void dec_java_call_counter() {
1028 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1029 _java_call_counter--;
1030 }
1031 private: // restore original namespace restriction
1032 #endif // ifdef ASSERT
1033
1034 #ifndef PRODUCT
1035 public:
1036 enum {
1037 jump_ring_buffer_size = 16
1038 };
1039 private: // restore original namespace restriction
1040 #endif
1041
1042 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1043
1044 ThreadFunction _entry_point;
1045
1046 JNIEnv _jni_environment;
1047
1048 // Deopt support
1049 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1050
1051 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1052 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1053 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1054 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
1055 // will be carried out as soon as possible, which, in most cases, is just before deoptimization of
1056 // the frame, when control returns to it.
1057 JvmtiDeferredUpdates* _jvmti_deferred_updates;
1058
1059 // Handshake value for fixing 6243940. We need a place for the i2c
1060 // adapter to store the callee Method*. This value is NEVER live
1061 // across a gc point so it does NOT have to be gc'd
1062 // The handshake is open ended since we can't be certain that it will
1063 // be NULLed. This is because we rarely ever see the race and end up
1064 // in handle_wrong_method which is the backend of the handshake. See
1065 // code in i2c adapters and handle_wrong_method.
1066
1067 Method* _callee_target;
1068
1069 // Used to pass back results to the interpreter or generated code running Java code.
1070 oop _vm_result; // oop result is GC-preserved
1071 Metadata* _vm_result_2; // non-oop result
1072
1073 // See ReduceInitialCardMarks: this holds the precise space interval of
1074 // the most recent slow path allocation for which compiled code has
1075 // elided card-marks for performance along the fast-path.
1076 MemRegion _deferred_card_mark;
1077
1078 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1079 // allocated during deoptimization
1080 // and by JNI_MonitorEnter/Exit
1081
1082 // Async. requests support
1083 enum AsyncRequests {
1084 _no_async_condition = 0,
1085 _async_exception,
1086 _async_unsafe_access_error
1087 };
1088 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1089 oop _pending_async_exception;
1090
1091 // Safepoint support
1092 public: // Expose _thread_state for SafeFetchInt()
1093 volatile JavaThreadState _thread_state;
1094 private:
1095 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1096 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1097
1098 // JavaThread termination support
1099 enum TerminatedTypes {
1100 _not_terminated = 0xDEAD - 2,
1101 _thread_exiting, // JavaThread::exit() has been called for this thread
1102 _thread_terminated, // JavaThread is removed from thread list
1103 _vm_exited // JavaThread is still executing native code, but VM is terminated
1104 // only VM_Exit can set _vm_exited
1105 };
1106
1107 // In general a JavaThread's _terminated field transitions as follows:
1108 //
1109 // _not_terminated => _thread_exiting => _thread_terminated
1110 //
1111 // _vm_exited is a special value to cover the case of a JavaThread
1112 // executing native code after the VM itself is terminated.
1113 volatile TerminatedTypes _terminated;
1114 // suspend/resume support
1115 volatile bool _suspend_equivalent; // Suspend equivalent condition
1116 jint _in_deopt_handler; // count of deoptimization
1117 // handlers thread is in
1118 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1119 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1120 // never locked) when throwing an exception. Used by interpreter only.
1121
1122 // JNI attach states:
1123 enum JNIAttachStates {
1124 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1125 _attaching_via_jni, // thread is attaching via JNI
1126 _attached_via_jni // thread has attached via JNI
1127 };
1128
1129 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1130 // A native thread that is attaching via JNI starts with a value
1131 // of _attaching_via_jni and transitions to _attached_via_jni.
1132 volatile JNIAttachStates _jni_attach_state;
1133
1134 public:
1135 // State of the stack guard pages for this thread.
1136 enum StackGuardState {
1137 stack_guard_unused, // not needed
1138 stack_guard_reserved_disabled,
1139 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1140 stack_guard_enabled // enabled
1141 };
1142
1143 private:
1144
1145 #if INCLUDE_JVMCI
1146 // The _pending_* fields below are used to communicate extra information
1147 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1148
1149 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1150 int _pending_deoptimization;
1151
1152 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1153 // before the monitor has been acquired.
1154 bool _pending_monitorenter;
1155
1156 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1157 bool _pending_transfer_to_interpreter;
1158
1159 // True if in a runtime call from compiled code that will deoptimize
1160 // and re-execute a failed heap allocation in the interpreter.
1161 bool _in_retryable_allocation;
1162
1163 // An id of a speculation that JVMCI compiled code can use to further describe and
1164 // uniquely identify the speculative optimization guarded by the uncommon trap
1165 jlong _pending_failed_speculation;
1166
1167 // These fields are mutually exclusive in terms of live ranges.
1168 union {
1169 // Communicates the pc at which the most recent implicit exception occurred
1170 // from the signal handler to a deoptimization stub.
1171 address _implicit_exception_pc;
1172
1173 // Communicates an alternative call target to an i2c stub from a JavaCall .
1174 address _alternate_call_target;
1175 } _jvmci;
1176
1177 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1178 jlong* _jvmci_counters;
1179
1180 public:
1181 static jlong* _jvmci_old_thread_counters;
1182 static void collect_counters(jlong* array, int length);
1183
1184 bool resize_counters(int current_size, int new_size);
1185
1186 static bool resize_all_jvmci_counters(int new_size);
1187
1188 private:
1189 #endif // INCLUDE_JVMCI
1190
1191 StackGuardState _stack_guard_state;
1192
1193 // Precompute the limit of the stack as used in stack overflow checks.
1194 // We load it from here to simplify the stack overflow check in assembly.
1195 address _stack_overflow_limit;
1196 address _reserved_stack_activation;
1197
1198 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1199 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1200 // code)
1201 volatile oop _exception_oop; // Exception thrown in compiled code
1202 volatile address _exception_pc; // PC where exception happened
1203 volatile address _exception_handler_pc; // PC for handler of exception
1204 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1205
1206 private:
1207 // support for JNI critical regions
1208 jint _jni_active_critical; // count of entries into JNI critical region
1209
1210 // Checked JNI: function name requires exception check
1211 char* _pending_jni_exception_check_fn;
1212
1213 // For deadlock detection.
1214 int _depth_first_number;
1215
1216 // JVMTI PopFrame support
1217 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1218 int _popframe_condition;
1219
1220 // If reallocation of scalar replaced objects fails, we throw OOM
1221 // and during exception propagation, pop the top
1222 // _frames_to_pop_failed_realloc frames, the ones that reference
1223 // failed reallocations.
1224 int _frames_to_pop_failed_realloc;
1225
1226 friend class VMThread;
1227 friend class ThreadWaitTransition;
1228 friend class VM_Exit;
1229
1230 void initialize(); // Initialized the instance variables
1231
1232 public:
1233 // Constructor
1234 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1235 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1236 ~JavaThread();
1237
1238 #ifdef ASSERT
1239 // verify this JavaThread hasn't be published in the Threads::list yet
1240 void verify_not_published();
1241 #endif // ASSERT
1242
1243 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1244 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1245 _jni_environment.functions = functionTable;
1246 }
1247 struct JNINativeInterface_* get_jni_functions() {
1248 return (struct JNINativeInterface_ *)_jni_environment.functions;
1249 }
1250
1251 // This function is called at thread creation to allow
1252 // platform specific thread variables to be initialized.
1253 void cache_global_variables();
1254
1255 // Executes Shutdown.shutdown()
1256 void invoke_shutdown_hooks();
1257
1258 // Cleanup on thread exit
1259 enum ExitType {
1260 normal_exit,
1261 jni_detach
1262 };
1263 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1264
1265 void cleanup_failed_attach_current_thread(bool is_daemon);
1266
1267 // Testers
1268 virtual bool is_Java_thread() const { return true; }
1269 virtual bool can_call_java() const { return true; }
1270
1271 virtual bool is_active_Java_thread() const {
1272 return on_thread_list() && !is_terminated();
1273 }
1274
1275 // Thread oop. threadObj() can be NULL for initial JavaThread
1276 // (or for threads attached via JNI)
1277 oop threadObj() const { return _threadObj; }
1278 void set_threadObj(oop p) { _threadObj = p; }
1279
1280 // Prepare thread and add to priority queue. If a priority is
1281 // not specified, use the priority of the thread object. Threads_lock
1282 // must be held while this function is called.
1283 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1284
1285 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1286 address saved_exception_pc() { return _saved_exception_pc; }
1287
1288
1289 ThreadFunction entry_point() const { return _entry_point; }
1290
1291 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1292 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1293
1294 // Last frame anchor routines
1295
1296 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1297
1298 // last_Java_sp
1299 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1300 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1301
1302 // last_Java_pc
1303
1304 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1305
1306 // Safepoint support
1307 inline JavaThreadState thread_state() const;
1308 inline void set_thread_state(JavaThreadState s);
1309 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1310 inline ThreadSafepointState* safepoint_state() const;
1311 inline void set_safepoint_state(ThreadSafepointState* state);
1312 inline bool is_at_poll_safepoint();
1313
1314 // JavaThread termination and lifecycle support:
1315 void smr_delete();
1316 bool on_thread_list() const { return _on_thread_list; }
1317 void set_on_thread_list() { _on_thread_list = true; }
1318
1319 // thread has called JavaThread::exit() or is terminated
1320 bool is_exiting() const;
1321 // thread is terminated (no longer on the threads list); we compare
1322 // against the two non-terminated values so that a freed JavaThread
1323 // will also be considered terminated.
1324 bool check_is_terminated(TerminatedTypes l_terminated) const {
1325 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1326 }
1327 bool is_terminated() const;
1328 void set_terminated(TerminatedTypes t);
1329 // special for Threads::remove() which is static:
1330 void set_terminated_value();
1331 void block_if_vm_exited();
1332
1333 bool doing_unsafe_access() { return _doing_unsafe_access; }
1334 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1335
1336 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1337 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1338
1339 inline void set_polling_page_release(void* poll_value);
1340 inline void set_polling_page(void* poll_value);
1341 inline volatile void* get_polling_page();
1342
1343 private:
1344 // Support for thread handshake operations
1345 HandshakeState _handshake;
1346 public:
1347 void set_handshake_operation(HandshakeOperation* op) {
1348 _handshake.set_operation(this, op);
1349 }
1350
1351 bool has_handshake() const {
1352 return _handshake.has_operation();
1353 }
1354
1355 void handshake_process_by_self() {
1356 _handshake.process_by_self(this);
1357 }
1358
1359 void handshake_process_by_vmthread() {
1360 _handshake.process_by_vmthread(this);
1361 }
1362
1363 // Suspend/resume support for JavaThread
1364 private:
1365 inline void set_ext_suspended();
1366 inline void clear_ext_suspended();
1367
1368 // Synchronize with another thread (most likely a JVMTI agent) that is deoptimizing objects of the
1369 // current thread, i.e. reverts optimizations based on escape analysis.
1370 void wait_for_object_deoptimization();
1371
1372 public:
1373 void java_suspend(); // higher-level suspension logic called by the public APIs
1374 void java_resume(); // higher-level resume logic called by the public APIs
1375 int java_suspend_self(); // low-level self-suspension mechanics
1376
1377 private:
1378 // mid-level wrapper around java_suspend_self to set up correct state and
1379 // check for a pending safepoint at the end
1380 void java_suspend_self_with_safepoint_check();
1381
1382 public:
1383 void check_and_wait_while_suspended() {
1384 assert(JavaThread::current() == this, "sanity check");
1385
1386 bool do_self_suspend;
1387 do {
1388 // were we externally suspended while we were waiting?
1389 do_self_suspend = handle_special_suspend_equivalent_condition();
1390 if (do_self_suspend) {
1391 // don't surprise the thread that suspended us by returning
1392 java_suspend_self();
1393 set_suspend_equivalent();
1394 }
1395 } while (do_self_suspend);
1396 }
1397 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1398 // Check for async exception in addition to safepoint and suspend request.
1399 static void check_special_condition_for_native_trans(JavaThread *thread);
1400
1401 // Same as check_special_condition_for_native_trans but finishes the
1402 // transition into thread_in_Java mode so that it can potentially
1403 // block.
1404 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1405
1406 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1407 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1408 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1409 // Warning: is_ext_suspend_completed() may temporarily drop the
1410 // SR_lock to allow the thread to reach a stable thread state if
1411 // it is currently in a transient thread state.
1412 return is_ext_suspend_completed(false /* !called_by_wait */,
1413 SuspendRetryDelay, bits);
1414 }
1415
1416 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1417 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1418 // passed as the count and delay parameters. Experiments with specific
1419 // calls to wait_for_ext_suspend_completion() can be done by passing
1420 // other values in the code. Experiments with all calls can be done
1421 // via the appropriate -XX options.
1422 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1423
1424 // test for suspend - most (all?) of these should go away
1425 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1426
1427 inline void set_external_suspend();
1428 inline void clear_external_suspend();
1429
1430 bool is_external_suspend() const {
1431 return (_suspend_flags & _external_suspend) != 0;
1432 }
1433 // Whenever a thread transitions from native to vm/java it must suspend
1434 // if external|deopt suspend is present.
1435 bool is_suspend_after_native() const {
1436 return (_suspend_flags & (_external_suspend | _ea_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
1437 }
1438
1439 // external suspend request is completed
1440 bool is_ext_suspended() const {
1441 return (_suspend_flags & _ext_suspended) != 0;
1442 }
1443
1444 bool is_external_suspend_with_lock() const {
1445 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1446 return is_external_suspend();
1447 }
1448
1449 // Special method to handle a pending external suspend request
1450 // when a suspend equivalent condition lifts.
1451 bool handle_special_suspend_equivalent_condition() {
1452 assert(is_suspend_equivalent(),
1453 "should only be called in a suspend equivalence condition");
1454 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1455 bool ret = is_external_suspend();
1456 if (!ret) {
1457 // not about to self-suspend so clear suspend equivalence
1458 clear_suspend_equivalent();
1459 }
1460 // implied else:
1461 // We have a pending external suspend request so we leave the
1462 // suspend_equivalent flag set until java_suspend_self() sets
1463 // the ext_suspended flag and clears the suspend_equivalent
1464 // flag. This insures that wait_for_ext_suspend_completion()
1465 // will return consistent values.
1466 return ret;
1467 }
1468
1469 // utility methods to see if we are doing some kind of suspension
1470 bool is_being_ext_suspended() const {
1471 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1472 return is_ext_suspended() || is_external_suspend();
1473 }
1474
1475 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1476
1477 void set_suspend_equivalent() { _suspend_equivalent = true; }
1478 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1479
1480 // Thread.stop support
1481 void send_thread_stop(oop throwable);
1482 AsyncRequests clear_special_runtime_exit_condition() {
1483 AsyncRequests x = _special_runtime_exit_condition;
1484 _special_runtime_exit_condition = _no_async_condition;
1485 return x;
1486 }
1487
1488 // Are any async conditions present?
1489 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1490
1491 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1492
1493 // these next two are also used for self-suspension and async exception support
1494 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1495
1496 // Return true if JavaThread has an asynchronous condition or
1497 // if external suspension is requested.
1498 bool has_special_runtime_exit_condition() {
1499 // Because we don't use is_external_suspend_with_lock
1500 // it is possible that we won't see an asynchronous external suspend
1501 // request that has just gotten started, i.e., SR_lock grabbed but
1502 // _external_suspend field change either not made yet or not visible
1503 // yet. However, this is okay because the request is asynchronous and
1504 // we will see the new flag value the next time through. It's also
1505 // possible that the external suspend request is dropped after
1506 // we have checked is_external_suspend(), we will recheck its value
1507 // under SR_lock in java_suspend_self().
1508 return (_special_runtime_exit_condition != _no_async_condition) ||
1509 is_external_suspend() || is_trace_suspend() || is_ea_obj_deopt_suspend();
1510 }
1511
1512 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1513
1514 inline void set_pending_async_exception(oop e);
1515
1516 // Fast-locking support
1517 bool is_lock_owned(address adr) const;
1518
1519 // Accessors for vframe array top
1520 // The linked list of vframe arrays are sorted on sp. This means when we
1521 // unpack the head must contain the vframe array to unpack.
1522 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1523 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1524
1525 // Side structure for deferring update of java frame locals until deopt occurs
1526 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; }
1527 void reset_deferred_updates() { _jvmti_deferred_updates = NULL; }
1528 void allocate_deferred_updates() {
1529 assert(_jvmti_deferred_updates == NULL, "already allocated");
1530 _jvmti_deferred_updates = new JvmtiDeferredUpdates();
1531 }
1532 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _jvmti_deferred_updates == NULL ? NULL : _jvmti_deferred_updates->deferred_locals(); }
1533
1534 // Relocking has to be deferred, if the lock owning thread is currently waiting on the monitor.
1535 int get_and_reset_relock_count_after_wait() {
1536 return deferred_updates() == NULL ? 0 : deferred_updates()->get_and_reset_relock_count_after_wait();
1537 }
1538 void inc_relock_count_after_wait() {
1539 if (deferred_updates() == NULL) {
1540 allocate_deferred_updates();
1541 }
1542 deferred_updates()->inc_relock_count_after_wait();
1543 }
1544
1545 // These only really exist to make debugging deopt problems simpler
1546
1547 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1548 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1549
1550 // The special resourceMark used during deoptimization
1551
1552 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1553 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1554
1555 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1556 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1557
1558 Method* callee_target() const { return _callee_target; }
1559 void set_callee_target (Method* x) { _callee_target = x; }
1560
1561 // Oop results of vm runtime calls
1562 oop vm_result() const { return _vm_result; }
1563 void set_vm_result (oop x) { _vm_result = x; }
1564
1565 Metadata* vm_result_2() const { return _vm_result_2; }
1566 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1567
1568 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1569 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1570
1571 #if INCLUDE_JVMCI
1572 int pending_deoptimization() const { return _pending_deoptimization; }
1573 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1574 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1575 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1576 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1577 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1578 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1579 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1580 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1581
1582 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1583 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1584 #endif // INCLUDE_JVMCI
1585
1586 // Exception handling for compiled methods
1587 oop exception_oop() const { return _exception_oop; }
1588 address exception_pc() const { return _exception_pc; }
1589 address exception_handler_pc() const { return _exception_handler_pc; }
1590 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1591
1592 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1593 void set_exception_pc(address a) { _exception_pc = a; }
1594 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1595 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1596
1597 void clear_exception_oop_and_pc() {
1598 set_exception_oop(NULL);
1599 set_exception_pc(NULL);
1600 }
1601
1602 // Stack overflow support
1603 //
1604 // (small addresses)
1605 //
1606 // -- <-- stack_end() ---
1607 // | |
1608 // | red pages |
1609 // | |
1610 // -- <-- stack_red_zone_base() |
1611 // | |
1612 // | guard
1613 // | yellow pages zone
1614 // | |
1615 // | |
1616 // -- <-- stack_yellow_zone_base() |
1617 // | |
1618 // | |
1619 // | reserved pages |
1620 // | |
1621 // -- <-- stack_reserved_zone_base() --- ---
1622 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1623 // | zone
1624 // \|/ size
1625 // some untouched memory ---
1626 //
1627 //
1628 // --
1629 // |
1630 // | shadow zone
1631 // |
1632 // --
1633 // x frame n
1634 // --
1635 // x frame n-1
1636 // x
1637 // --
1638 // ...
1639 //
1640 // --
1641 // x frame 0
1642 // -- <-- stack_base()
1643 //
1644 // (large addresses)
1645 //
1646
1647 private:
1648 // These values are derived from flags StackRedPages, StackYellowPages,
1649 // StackReservedPages and StackShadowPages. The zone size is determined
1650 // ergonomically if page_size > 4K.
1651 static size_t _stack_red_zone_size;
1652 static size_t _stack_yellow_zone_size;
1653 static size_t _stack_reserved_zone_size;
1654 static size_t _stack_shadow_zone_size;
1655 public:
1656 inline size_t stack_available(address cur_sp);
1657
1658 static size_t stack_red_zone_size() {
1659 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1660 return _stack_red_zone_size;
1661 }
1662 static void set_stack_red_zone_size(size_t s) {
1663 assert(is_aligned(s, os::vm_page_size()),
1664 "We can not protect if the red zone size is not page aligned.");
1665 assert(_stack_red_zone_size == 0, "This should be called only once.");
1666 _stack_red_zone_size = s;
1667 }
1668 address stack_red_zone_base() {
1669 return (address)(stack_end() + stack_red_zone_size());
1670 }
1671 bool in_stack_red_zone(address a) {
1672 return a <= stack_red_zone_base() && a >= stack_end();
1673 }
1674
1675 static size_t stack_yellow_zone_size() {
1676 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1677 return _stack_yellow_zone_size;
1678 }
1679 static void set_stack_yellow_zone_size(size_t s) {
1680 assert(is_aligned(s, os::vm_page_size()),
1681 "We can not protect if the yellow zone size is not page aligned.");
1682 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1683 _stack_yellow_zone_size = s;
1684 }
1685
1686 static size_t stack_reserved_zone_size() {
1687 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1688 return _stack_reserved_zone_size;
1689 }
1690 static void set_stack_reserved_zone_size(size_t s) {
1691 assert(is_aligned(s, os::vm_page_size()),
1692 "We can not protect if the reserved zone size is not page aligned.");
1693 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1694 _stack_reserved_zone_size = s;
1695 }
1696 address stack_reserved_zone_base() {
1697 return (address)(stack_end() +
1698 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1699 }
1700 bool in_stack_reserved_zone(address a) {
1701 return (a <= stack_reserved_zone_base()) &&
1702 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1703 }
1704
1705 static size_t stack_yellow_reserved_zone_size() {
1706 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1707 }
1708 bool in_stack_yellow_reserved_zone(address a) {
1709 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1710 }
1711
1712 // Size of red + yellow + reserved zones.
1713 static size_t stack_guard_zone_size() {
1714 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1715 }
1716
1717 static size_t stack_shadow_zone_size() {
1718 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1719 return _stack_shadow_zone_size;
1720 }
1721 static void set_stack_shadow_zone_size(size_t s) {
1722 // The shadow area is not allocated or protected, so
1723 // it needs not be page aligned.
1724 // But the stack bang currently assumes that it is a
1725 // multiple of page size. This guarantees that the bang
1726 // loop touches all pages in the shadow zone.
1727 // This can be guaranteed differently, as well. E.g., if
1728 // the page size is a multiple of 4K, banging in 4K steps
1729 // suffices to touch all pages. (Some pages are banged
1730 // several times, though.)
1731 assert(is_aligned(s, os::vm_page_size()),
1732 "Stack bang assumes multiple of page size.");
1733 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1734 _stack_shadow_zone_size = s;
1735 }
1736
1737 void create_stack_guard_pages();
1738 void remove_stack_guard_pages();
1739
1740 void enable_stack_reserved_zone();
1741 void disable_stack_reserved_zone();
1742 void enable_stack_yellow_reserved_zone();
1743 void disable_stack_yellow_reserved_zone();
1744 void enable_stack_red_zone();
1745 void disable_stack_red_zone();
1746
1747 inline bool stack_guard_zone_unused();
1748 inline bool stack_yellow_reserved_zone_disabled();
1749 inline bool stack_reserved_zone_disabled();
1750 inline bool stack_guards_enabled();
1751
1752 address reserved_stack_activation() const { return _reserved_stack_activation; }
1753 void set_reserved_stack_activation(address addr) {
1754 assert(_reserved_stack_activation == stack_base()
1755 || _reserved_stack_activation == NULL
1756 || addr == stack_base(), "Must not be set twice");
1757 _reserved_stack_activation = addr;
1758 }
1759
1760 // Attempt to reguard the stack after a stack overflow may have occurred.
1761 // Returns true if (a) guard pages are not needed on this thread, (b) the
1762 // pages are already guarded, or (c) the pages were successfully reguarded.
1763 // Returns false if there is not enough stack space to reguard the pages, in
1764 // which case the caller should unwind a frame and try again. The argument
1765 // should be the caller's (approximate) sp.
1766 bool reguard_stack(address cur_sp);
1767 // Similar to above but see if current stackpoint is out of the guard area
1768 // and reguard if possible.
1769 bool reguard_stack(void);
1770
1771 address stack_overflow_limit() { return _stack_overflow_limit; }
1772 void set_stack_overflow_limit() {
1773 _stack_overflow_limit =
1774 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1775 }
1776
1777 // Misc. accessors/mutators
1778 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1779 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1780 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1781
1782 // For assembly stub generation
1783 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1784 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1785 static ByteSize pending_jni_exception_check_fn_offset() {
1786 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1787 }
1788 static ByteSize last_Java_sp_offset() {
1789 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1790 }
1791 static ByteSize last_Java_pc_offset() {
1792 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1793 }
1794 static ByteSize frame_anchor_offset() {
1795 return byte_offset_of(JavaThread, _anchor);
1796 }
1797 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1798 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1799 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1800 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1801 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1802 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1803 #if INCLUDE_JVMCI
1804 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1805 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1806 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1807 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1808 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1809 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1810 #endif // INCLUDE_JVMCI
1811 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1812 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1813 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1814 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1815 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1816 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1817 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1818 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1819
1820 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1821 static ByteSize should_post_on_exceptions_flag_offset() {
1822 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1823 }
1824 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1825
1826 // Returns the jni environment for this thread
1827 JNIEnv* jni_environment() { return &_jni_environment; }
1828
1829 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1830 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1831 // Only return NULL if thread is off the thread list; starting to
1832 // exit should not return NULL.
1833 if (thread_from_jni_env->is_terminated()) {
1834 thread_from_jni_env->block_if_vm_exited();
1835 return NULL;
1836 } else {
1837 return thread_from_jni_env;
1838 }
1839 }
1840
1841 // JNI critical regions. These can nest.
1842 bool in_critical() { return _jni_active_critical > 0; }
1843 bool in_last_critical() { return _jni_active_critical == 1; }
1844 inline void enter_critical();
1845 void exit_critical() {
1846 assert(Thread::current() == this, "this must be current thread");
1847 _jni_active_critical--;
1848 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1849 }
1850
1851 // Checked JNI: is the programmer required to check for exceptions, if so specify
1852 // which function name. Returning to a Java frame should implicitly clear the
1853 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1854 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1855 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1856 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1857 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1858 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1859 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1860
1861 // For deadlock detection
1862 int depth_first_number() { return _depth_first_number; }
1863 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1864
1865 private:
1866 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1867
1868 public:
1869 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1870 void add_monitor_chunk(MonitorChunk* chunk);
1871 void remove_monitor_chunk(MonitorChunk* chunk);
1872 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1873 void inc_in_deopt_handler() { _in_deopt_handler++; }
1874 void dec_in_deopt_handler() {
1875 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1876 if (_in_deopt_handler > 0) { // robustness
1877 _in_deopt_handler--;
1878 }
1879 }
1880
1881 private:
1882 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1883
1884 public:
1885
1886 // Frame iteration; calls the function f for all frames on the stack
1887 void frames_do(void f(frame*, const RegisterMap*));
1888
1889 // Memory operations
1890 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1891
1892 // Sweeper operations
1893 virtual void nmethods_do(CodeBlobClosure* cf);
1894
1895 // RedefineClasses Support
1896 void metadata_do(MetadataClosure* f);
1897
1898 // Debug method asserting thread states are correct during a handshake operation.
1899 DEBUG_ONLY(void verify_states_for_handshake();)
1900
1901 // Misc. operations
1902 char* name() const { return (char*)get_thread_name(); }
1903 void print_on(outputStream* st, bool print_extended_info) const;
1904 void print_on(outputStream* st) const { print_on(st, false); }
1905 void print() const;
1906 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1907 void print_on_error(outputStream* st, char* buf, int buflen) const;
1908 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1909 void verify();
1910 const char* get_thread_name() const;
1911 protected:
1912 // factor out low-level mechanics for use in both normal and error cases
1913 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1914 public:
1915 // Accessing frames
1916 frame last_frame() {
1917 _anchor.make_walkable(this);
1918 return pd_last_frame();
1919 }
1920 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1921
1922 // Returns method at 'depth' java or native frames down the stack
1923 // Used for security checks
1924 Klass* security_get_caller_class(int depth);
1925
1926 // Print stack trace in external format
1927 void print_stack_on(outputStream* st);
1928 void print_stack() { print_stack_on(tty); }
1929
1930 // Print stack traces in various internal formats
1931 void trace_stack() PRODUCT_RETURN;
1932 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1933 void trace_frames() PRODUCT_RETURN;
1934
1935 // Print an annotated view of the stack frames
1936 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1937 void validate_frame_layout() {
1938 print_frame_layout(0, true);
1939 }
1940
1941 // Function for testing deoptimization
1942 void deoptimize();
1943 void make_zombies();
1944
1945 void deoptimized_wrt_marked_nmethods();
1946
1947 public:
1948 // Returns the running thread as a JavaThread
1949 static inline JavaThread* current();
1950
1951 // Returns the active Java thread. Do not use this if you know you are calling
1952 // from a JavaThread, as it's slower than JavaThread::current. If called from
1953 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1954 // operation. You may not want that either.
1955 static JavaThread* active();
1956
1957 inline CompilerThread* as_CompilerThread();
1958
1959 protected:
1960 virtual void pre_run();
1961 virtual void run();
1962 void thread_main_inner();
1963 virtual void post_run();
1964
1965
1966 private:
1967 GrowableArray<oop>* _array_for_gc;
1968 public:
1969
1970 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1971
1972 public:
1973 // Thread local information maintained by JVMTI.
1974 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1975 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1976 // getter is used to get this JavaThread's JvmtiThreadState if it has
1977 // one which means NULL can be returned. JvmtiThreadState::state_for()
1978 // is used to get the specified JavaThread's JvmtiThreadState if it has
1979 // one or it allocates a new JvmtiThreadState for the JavaThread and
1980 // returns it. JvmtiThreadState::state_for() will return NULL only if
1981 // the specified JavaThread is exiting.
1982 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1983 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1984
1985 // JVMTI PopFrame support
1986 // Setting and clearing popframe_condition
1987 // All of these enumerated values are bits. popframe_pending
1988 // indicates that a PopFrame() has been requested and not yet been
1989 // completed. popframe_processing indicates that that PopFrame() is in
1990 // the process of being completed. popframe_force_deopt_reexecution_bit
1991 // indicates that special handling is required when returning to a
1992 // deoptimized caller.
1993 enum PopCondition {
1994 popframe_inactive = 0x00,
1995 popframe_pending_bit = 0x01,
1996 popframe_processing_bit = 0x02,
1997 popframe_force_deopt_reexecution_bit = 0x04
1998 };
1999 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
2000 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
2001 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
2002 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
2003 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
2004 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
2005 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
2006 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
2007 #ifdef CC_INTERP
2008 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
2009 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
2010 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
2011 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
2012 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
2013 #endif
2014
2015 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
2016 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
2017 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
2018
2019 private:
2020 // Saved incoming arguments to popped frame.
2021 // Used only when popped interpreted frame returns to deoptimized frame.
2022 void* _popframe_preserved_args;
2023 int _popframe_preserved_args_size;
2024
2025 public:
2026 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2027 void* popframe_preserved_args();
2028 ByteSize popframe_preserved_args_size();
2029 WordSize popframe_preserved_args_size_in_words();
2030 void popframe_free_preserved_args();
2031
2032
2033 private:
2034 JvmtiThreadState *_jvmti_thread_state;
2035
2036 // Used by the interpreter in fullspeed mode for frame pop, method
2037 // entry, method exit and single stepping support. This field is
2038 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
2039 // It can be set to zero asynchronously (i.e., without a VM operation
2040 // or a lock) so we have to be very careful.
2041 int _interp_only_mode;
2042
2043 public:
2044 // used by the interpreter for fullspeed debugging support (see above)
2045 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2046 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2047 int get_interp_only_mode() { return _interp_only_mode; }
2048 void increment_interp_only_mode() { ++_interp_only_mode; }
2049 void decrement_interp_only_mode() { --_interp_only_mode; }
2050
2051 // support for cached flag that indicates whether exceptions need to be posted for this thread
2052 // if this is false, we can avoid deoptimizing when events are thrown
2053 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2054 private:
2055 int _should_post_on_exceptions_flag;
2056
2057 public:
2058 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2059 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2060
2061 private:
2062 ThreadStatistics *_thread_stat;
2063
2064 public:
2065 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2066
2067 // Return a blocker object for which this thread is blocked parking.
2068 oop current_park_blocker();
2069
2070 private:
2071 static size_t _stack_size_at_create;
2072
2073 public:
2074 static inline size_t stack_size_at_create(void) {
2075 return _stack_size_at_create;
2076 }
2077 static inline void set_stack_size_at_create(size_t value) {
2078 _stack_size_at_create = value;
2079 }
2080
2081 // Machine dependent stuff
2082 #include OS_CPU_HEADER(thread)
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 #if defined(ASSERT) && COMPILER2_OR_JVMCI
2147 // See Deoptimization::deoptimize_objects_alot_loop()
2148 class DeoptimizeObjectsALotThread : public JavaThread {
2149 public:
2150 DeoptimizeObjectsALotThread();
2151 };
2152 #endif // defined(ASSERT) && COMPILER2_OR_JVMCI
2153
2154 // A thread used for Compilation.
2155 class CompilerThread : public JavaThread {
2156 friend class VMStructs;
2157 private:
2158 CompilerCounters* _counters;
2159
2160 ciEnv* _env;
2161 CompileLog* _log;
2162 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2163 CompileQueue* _queue;
2164 BufferBlob* _buffer_blob;
2165
2166 AbstractCompiler* _compiler;
2167 TimeStamp _idle_time;
2168
2169 public:
2170
2171 static CompilerThread* current();
2172
2173 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2174 ~CompilerThread();
2175
2176 bool is_Compiler_thread() const { return true; }
2177
2178 virtual bool can_call_java() const;
2179
2180 // Hide native compiler threads from external view.
2181 bool is_hidden_from_external_view() const { return !can_call_java(); }
2182
2183 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2184 AbstractCompiler* compiler() const { return _compiler; }
2185
2186 CompileQueue* queue() const { return _queue; }
2187 CompilerCounters* counters() const { return _counters; }
2188
2189 // Get/set the thread's compilation environment.
2190 ciEnv* env() { return _env; }
2191 void set_env(ciEnv* env) { _env = env; }
2192
2193 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2194 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2195
2196 // Get/set the thread's logging information
2197 CompileLog* log() { return _log; }
2198 void init_log(CompileLog* log) {
2199 // Set once, for good.
2200 assert(_log == NULL, "set only once");
2201 _log = log;
2202 }
2203
2204 void start_idle_timer() { _idle_time.update(); }
2205 jlong idle_time_millis() {
2206 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2207 }
2208
2209 #ifndef PRODUCT
2210 private:
2211 IdealGraphPrinter *_ideal_graph_printer;
2212 public:
2213 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2214 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2215 #endif
2216
2217 // Get/set the thread's current task
2218 CompileTask* task() { return _task; }
2219 void set_task(CompileTask* task) { _task = task; }
2220 };
2221
2222 inline CompilerThread* CompilerThread::current() {
2223 return JavaThread::current()->as_CompilerThread();
2224 }
2225
2226 // The active thread queue. It also keeps track of the current used
2227 // thread priorities.
2228 class Threads: AllStatic {
2229 friend class VMStructs;
2230 private:
2231 static int _number_of_threads;
2232 static int _number_of_non_daemon_threads;
2233 static int _return_code;
2234 static uintx _thread_claim_token;
2235 #ifdef ASSERT
2236 static bool _vm_complete;
2237 #endif
2238
2239 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2240 static void initialize_jsr292_core_classes(TRAPS);
2241
2242 public:
2243 // Thread management
2244 // force_daemon is a concession to JNI, where we may need to add a
2245 // thread to the thread list before allocating its thread object
2246 static void add(JavaThread* p, bool force_daemon = false);
2247 static void remove(JavaThread* p, bool is_daemon);
2248 static void non_java_threads_do(ThreadClosure* tc);
2249 static void java_threads_do(ThreadClosure* tc);
2250 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2251 static void threads_do(ThreadClosure* tc);
2252 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2253
2254 // Initializes the vm and creates the vm thread
2255 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2256 static void convert_vm_init_libraries_to_agents();
2257 static void create_vm_init_libraries();
2258 static void create_vm_init_agents();
2259 static void shutdown_vm_agents();
2260 static bool destroy_vm();
2261 // Supported VM versions via JNI
2262 // Includes JNI_VERSION_1_1
2263 static jboolean is_supported_jni_version_including_1_1(jint version);
2264 // Does not include JNI_VERSION_1_1
2265 static jboolean is_supported_jni_version(jint version);
2266
2267 // The "thread claim token" provides a way for threads to be claimed
2268 // by parallel worker tasks.
2269 //
2270 // Each thread contains a "token" field. A task will claim the
2271 // thread only if its token is different from the global token,
2272 // which is updated by calling change_thread_claim_token(). When
2273 // a thread is claimed, it's token is set to the global token value
2274 // so other threads in the same iteration pass won't claim it.
2275 //
2276 // For this to work change_thread_claim_token() needs to be called
2277 // exactly once in sequential code before starting parallel tasks
2278 // that should claim threads.
2279 //
2280 // New threads get their token set to 0 and change_thread_claim_token()
2281 // never sets the global token to 0.
2282 static uintx thread_claim_token() { return _thread_claim_token; }
2283 static void change_thread_claim_token();
2284 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2285
2286 // Apply "f->do_oop" to all root oops in all threads.
2287 // This version may only be called by sequential code.
2288 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2289 // This version may be called by sequential or parallel code.
2290 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
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