Mon, 03 Jan 2011 14:09:11 -0500
6302804: Hotspot VM dies ungraceful death when C heap is exhausted in various places.
Summary: enhance the error reporting mechanism to help user to fix the problem rather than making it look like a VM error.
Reviewed-by: kvn, kamg
1 /*
2 * Copyright (c) 1997, 2010, 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 */
25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
26 #define SHARE_VM_RUNTIME_THREAD_HPP
28 #include "memory/allocation.hpp"
29 #include "memory/threadLocalAllocBuffer.hpp"
30 #include "oops/oop.hpp"
31 #include "prims/jni.h"
32 #include "prims/jvmtiExport.hpp"
33 #include "runtime/frame.hpp"
34 #include "runtime/javaFrameAnchor.hpp"
35 #include "runtime/jniHandles.hpp"
36 #include "runtime/mutexLocker.hpp"
37 #include "runtime/os.hpp"
38 #include "runtime/osThread.hpp"
39 #include "runtime/park.hpp"
40 #include "runtime/safepoint.hpp"
41 #include "runtime/stubRoutines.hpp"
42 #include "runtime/threadLocalStorage.hpp"
43 #include "runtime/unhandledOops.hpp"
44 #include "utilities/exceptions.hpp"
45 #include "utilities/top.hpp"
46 #ifndef SERIALGC
47 #include "gc_implementation/g1/dirtyCardQueue.hpp"
48 #include "gc_implementation/g1/satbQueue.hpp"
49 #endif
50 #ifdef ZERO
51 #ifdef TARGET_ARCH_zero
52 # include "stack_zero.hpp"
53 #endif
54 #endif
56 class ThreadSafepointState;
57 class ThreadProfiler;
59 class JvmtiThreadState;
60 class JvmtiGetLoadedClassesClosure;
61 class ThreadStatistics;
62 class ConcurrentLocksDump;
63 class ParkEvent ;
64 class Parker;
66 class ciEnv;
67 class CompileThread;
68 class CompileLog;
69 class CompileTask;
70 class CompileQueue;
71 class CompilerCounters;
72 class vframeArray;
74 class DeoptResourceMark;
75 class jvmtiDeferredLocalVariableSet;
77 class GCTaskQueue;
78 class ThreadClosure;
79 class IdealGraphPrinter;
81 class WorkerThread;
83 // Class hierarchy
84 // - Thread
85 // - NamedThread
86 // - VMThread
87 // - ConcurrentGCThread
88 // - WorkerThread
89 // - GangWorker
90 // - GCTaskThread
91 // - JavaThread
92 // - WatcherThread
94 class Thread: public ThreadShadow {
95 friend class VMStructs;
96 private:
97 // Exception handling
98 // (Note: _pending_exception and friends are in ThreadShadow)
99 //oop _pending_exception; // pending exception for current thread
100 // const char* _exception_file; // file information for exception (debugging only)
101 // int _exception_line; // line information for exception (debugging only)
103 // Support for forcing alignment of thread objects for biased locking
104 void* _real_malloc_address;
105 public:
106 void* operator new(size_t size);
107 void operator delete(void* p);
108 private:
110 // ***************************************************************
111 // Suspend and resume support
112 // ***************************************************************
113 //
114 // VM suspend/resume no longer exists - it was once used for various
115 // things including safepoints but was deprecated and finally removed
116 // in Java 7. Because VM suspension was considered "internal" Java-level
117 // suspension was considered "external", and this legacy naming scheme
118 // remains.
119 //
120 // External suspend/resume requests come from JVM_SuspendThread,
121 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
122 // ResumeThread. External
123 // suspend requests cause _external_suspend to be set and external
124 // resume requests cause _external_suspend to be cleared.
125 // External suspend requests do not nest on top of other external
126 // suspend requests. The higher level APIs reject suspend requests
127 // for already suspended threads.
128 //
129 // The external_suspend
130 // flag is checked by has_special_runtime_exit_condition() and java thread
131 // will self-suspend when handle_special_runtime_exit_condition() is
132 // called. Most uses of the _thread_blocked state in JavaThreads are
133 // considered the same as being externally suspended; if the blocking
134 // condition lifts, the JavaThread will self-suspend. Other places
135 // where VM checks for external_suspend include:
136 // + mutex granting (do not enter monitors when thread is suspended)
137 // + state transitions from _thread_in_native
138 //
139 // In general, java_suspend() does not wait for an external suspend
140 // request to complete. When it returns, the only guarantee is that
141 // the _external_suspend field is true.
142 //
143 // wait_for_ext_suspend_completion() is used to wait for an external
144 // suspend request to complete. External suspend requests are usually
145 // followed by some other interface call that requires the thread to
146 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
147 // the interface that requires quiescence, we give the JavaThread a
148 // chance to self-suspend before we need it to be quiescent. This
149 // improves overall suspend/query performance.
150 //
151 // _suspend_flags controls the behavior of java_ suspend/resume.
152 // It must be set under the protection of SR_lock. Read from the flag is
153 // OK without SR_lock as long as the value is only used as a hint.
154 // (e.g., check _external_suspend first without lock and then recheck
155 // inside SR_lock and finish the suspension)
156 //
157 // _suspend_flags is also overloaded for other "special conditions" so
158 // that a single check indicates whether any special action is needed
159 // eg. for async exceptions.
160 // -------------------------------------------------------------------
161 // Notes:
162 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
163 // but we still update its value to keep other part of the system (mainly
164 // JVMTI) happy. ThreadState is legacy code (see notes in
165 // osThread.hpp).
166 //
167 // 2. It would be more natural if set_external_suspend() is private and
168 // part of java_suspend(), but that probably would affect the suspend/query
169 // performance. Need more investigation on this.
170 //
172 // suspend/resume lock: used for self-suspend
173 Monitor* _SR_lock;
175 protected:
176 enum SuspendFlags {
177 // NOTE: avoid using the sign-bit as cc generates different test code
178 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
180 _external_suspend = 0x20000000U, // thread is asked to self suspend
181 _ext_suspended = 0x40000000U, // thread has self-suspended
182 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
184 _has_async_exception = 0x00000001U // there is a pending async exception
185 };
187 // various suspension related flags - atomically updated
188 // overloaded for async exception checking in check_special_condition_for_native_trans.
189 volatile uint32_t _suspend_flags;
191 private:
192 int _num_nested_signal;
194 public:
195 void enter_signal_handler() { _num_nested_signal++; }
196 void leave_signal_handler() { _num_nested_signal--; }
197 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
199 private:
200 // Debug tracing
201 static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN;
203 // Active_handles points to a block of handles
204 JNIHandleBlock* _active_handles;
206 // One-element thread local free list
207 JNIHandleBlock* _free_handle_block;
209 // Point to the last handle mark
210 HandleMark* _last_handle_mark;
212 // The parity of the last strong_roots iteration in which this thread was
213 // claimed as a task.
214 jint _oops_do_parity;
216 public:
217 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
218 HandleMark* last_handle_mark() const { return _last_handle_mark; }
219 private:
221 // debug support for checking if code does allow safepoints or not
222 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
223 // mutex, or blocking on an object synchronizer (Java locking).
224 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
225 // If !allow_allocation(), then an assertion failure will happen during allocation
226 // (Hence, !allow_safepoint() => !allow_allocation()).
227 //
228 // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
229 //
230 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
231 debug_only (int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
233 // Used by SkipGCALot class.
234 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
236 // Record when GC is locked out via the GC_locker mechanism
237 CHECK_UNHANDLED_OOPS_ONLY(int _gc_locked_out_count;)
239 friend class No_Alloc_Verifier;
240 friend class No_Safepoint_Verifier;
241 friend class Pause_No_Safepoint_Verifier;
242 friend class ThreadLocalStorage;
243 friend class GC_locker;
245 ThreadLocalAllocBuffer _tlab; // Thread-local eden
247 int _vm_operation_started_count; // VM_Operation support
248 int _vm_operation_completed_count; // VM_Operation support
250 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
251 // is waiting to lock
252 bool _current_pending_monitor_is_from_java; // locking is from Java code
254 // ObjectMonitor on which this thread called Object.wait()
255 ObjectMonitor* _current_waiting_monitor;
257 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
258 public:
259 ObjectMonitor * omFreeList ;
260 int omFreeCount ; // length of omFreeList
261 int omFreeProvision ; // reload chunk size
262 ObjectMonitor * omInUseList; // SLL to track monitors in circulation
263 int omInUseCount; // length of omInUseList
265 public:
266 enum {
267 is_definitely_current_thread = true
268 };
270 // Constructor
271 Thread();
272 virtual ~Thread();
274 // initializtion
275 void initialize_thread_local_storage();
277 // thread entry point
278 virtual void run();
280 // Testers
281 virtual bool is_VM_thread() const { return false; }
282 virtual bool is_Java_thread() const { return false; }
283 // Remove this ifdef when C1 is ported to the compiler interface.
284 virtual bool is_Compiler_thread() const { return false; }
285 virtual bool is_hidden_from_external_view() const { return false; }
286 virtual bool is_jvmti_agent_thread() const { return false; }
287 // True iff the thread can perform GC operations at a safepoint.
288 // Generally will be true only of VM thread and parallel GC WorkGang
289 // threads.
290 virtual bool is_GC_task_thread() const { return false; }
291 virtual bool is_Watcher_thread() const { return false; }
292 virtual bool is_ConcurrentGC_thread() const { return false; }
293 virtual bool is_Named_thread() const { return false; }
294 virtual bool is_Worker_thread() const { return false; }
296 // Casts
297 virtual WorkerThread* as_Worker_thread() const { return NULL; }
299 virtual char* name() const { return (char*)"Unknown thread"; }
301 // Returns the current thread
302 static inline Thread* current();
304 // Common thread operations
305 static void set_priority(Thread* thread, ThreadPriority priority);
306 static ThreadPriority get_priority(const Thread* const thread);
307 static void start(Thread* thread);
308 static void interrupt(Thread* thr);
309 static bool is_interrupted(Thread* thr, bool clear_interrupted);
311 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
312 Monitor* SR_lock() const { return _SR_lock; }
314 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
316 void set_suspend_flag(SuspendFlags f) {
317 assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
318 uint32_t flags;
319 do {
320 flags = _suspend_flags;
321 }
322 while (Atomic::cmpxchg((jint)(flags | f),
323 (volatile jint*)&_suspend_flags,
324 (jint)flags) != (jint)flags);
325 }
326 void clear_suspend_flag(SuspendFlags f) {
327 assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
328 uint32_t flags;
329 do {
330 flags = _suspend_flags;
331 }
332 while (Atomic::cmpxchg((jint)(flags & ~f),
333 (volatile jint*)&_suspend_flags,
334 (jint)flags) != (jint)flags);
335 }
337 void set_has_async_exception() {
338 set_suspend_flag(_has_async_exception);
339 }
340 void clear_has_async_exception() {
341 clear_suspend_flag(_has_async_exception);
342 }
344 // Support for Unhandled Oop detection
345 #ifdef CHECK_UNHANDLED_OOPS
346 private:
347 UnhandledOops *_unhandled_oops;
348 public:
349 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
350 // Mark oop safe for gc. It may be stack allocated but won't move.
351 void allow_unhandled_oop(oop *op) {
352 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
353 }
354 // Clear oops at safepoint so crashes point to unhandled oop violator
355 void clear_unhandled_oops() {
356 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
357 }
358 bool is_gc_locked_out() { return _gc_locked_out_count > 0; }
359 #endif // CHECK_UNHANDLED_OOPS
361 #ifndef PRODUCT
362 bool skip_gcalot() { return _skip_gcalot; }
363 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
364 #endif
366 public:
367 // Installs a pending exception to be inserted later
368 static void send_async_exception(oop thread_oop, oop java_throwable);
370 // Resource area
371 ResourceArea* resource_area() const { return _resource_area; }
372 void set_resource_area(ResourceArea* area) { _resource_area = area; }
374 OSThread* osthread() const { return _osthread; }
375 void set_osthread(OSThread* thread) { _osthread = thread; }
377 // JNI handle support
378 JNIHandleBlock* active_handles() const { return _active_handles; }
379 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
380 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
381 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
383 // Internal handle support
384 HandleArea* handle_area() const { return _handle_area; }
385 void set_handle_area(HandleArea* area) { _handle_area = area; }
387 // Thread-Local Allocation Buffer (TLAB) support
388 ThreadLocalAllocBuffer& tlab() { return _tlab; }
389 void initialize_tlab() {
390 if (UseTLAB) {
391 tlab().initialize();
392 }
393 }
395 // VM operation support
396 int vm_operation_ticket() { return ++_vm_operation_started_count; }
397 int vm_operation_completed_count() { return _vm_operation_completed_count; }
398 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
400 // For tracking the heavyweight monitor the thread is pending on.
401 ObjectMonitor* current_pending_monitor() {
402 return _current_pending_monitor;
403 }
404 void set_current_pending_monitor(ObjectMonitor* monitor) {
405 _current_pending_monitor = monitor;
406 }
407 void set_current_pending_monitor_is_from_java(bool from_java) {
408 _current_pending_monitor_is_from_java = from_java;
409 }
410 bool current_pending_monitor_is_from_java() {
411 return _current_pending_monitor_is_from_java;
412 }
414 // For tracking the ObjectMonitor on which this thread called Object.wait()
415 ObjectMonitor* current_waiting_monitor() {
416 return _current_waiting_monitor;
417 }
418 void set_current_waiting_monitor(ObjectMonitor* monitor) {
419 _current_waiting_monitor = monitor;
420 }
422 // GC support
423 // Apply "f->do_oop" to all root oops in "this".
424 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
425 void oops_do(OopClosure* f, CodeBlobClosure* cf);
427 // Handles the parallel case for the method below.
428 private:
429 bool claim_oops_do_par_case(int collection_parity);
430 public:
431 // Requires that "collection_parity" is that of the current strong roots
432 // iteration. If "is_par" is false, sets the parity of "this" to
433 // "collection_parity", and returns "true". If "is_par" is true,
434 // uses an atomic instruction to set the current threads parity to
435 // "collection_parity", if it is not already. Returns "true" iff the
436 // calling thread does the update, this indicates that the calling thread
437 // has claimed the thread's stack as a root groop in the current
438 // collection.
439 bool claim_oops_do(bool is_par, int collection_parity) {
440 if (!is_par) {
441 _oops_do_parity = collection_parity;
442 return true;
443 } else {
444 return claim_oops_do_par_case(collection_parity);
445 }
446 }
448 // Sweeper support
449 void nmethods_do(CodeBlobClosure* cf);
451 // Used by fast lock support
452 virtual bool is_lock_owned(address adr) const;
454 // Check if address is in the stack of the thread (not just for locks).
455 // Warning: the method can only be used on the running thread
456 bool is_in_stack(address adr) const;
458 // Sets this thread as starting thread. Returns failure if thread
459 // creation fails due to lack of memory, too many threads etc.
460 bool set_as_starting_thread();
462 protected:
463 // OS data associated with the thread
464 OSThread* _osthread; // Platform-specific thread information
466 // Thread local resource area for temporary allocation within the VM
467 ResourceArea* _resource_area;
469 // Thread local handle area for allocation of handles within the VM
470 HandleArea* _handle_area;
472 // Support for stack overflow handling, get_thread, etc.
473 address _stack_base;
474 size_t _stack_size;
475 uintptr_t _self_raw_id; // used by get_thread (mutable)
476 int _lgrp_id;
478 public:
479 // Stack overflow support
480 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
482 void set_stack_base(address base) { _stack_base = base; }
483 size_t stack_size() const { return _stack_size; }
484 void set_stack_size(size_t size) { _stack_size = size; }
485 void record_stack_base_and_size();
487 bool on_local_stack(address adr) const {
488 /* QQQ this has knowledge of direction, ought to be a stack method */
489 return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
490 }
492 int lgrp_id() const { return _lgrp_id; }
493 void set_lgrp_id(int value) { _lgrp_id = value; }
495 // Printing
496 void print_on(outputStream* st) const;
497 void print() const { print_on(tty); }
498 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
500 // Debug-only code
502 #ifdef ASSERT
503 private:
504 // Deadlock detection support for Mutex locks. List of locks own by thread.
505 Monitor *_owned_locks;
506 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
507 // thus the friendship
508 friend class Mutex;
509 friend class Monitor;
511 public:
512 void print_owned_locks_on(outputStream* st) const;
513 void print_owned_locks() const { print_owned_locks_on(tty); }
514 Monitor * owned_locks() const { return _owned_locks; }
515 bool owns_locks() const { return owned_locks() != NULL; }
516 bool owns_locks_but_compiled_lock() const;
518 // Deadlock detection
519 bool allow_allocation() { return _allow_allocation_count == 0; }
520 #endif
522 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
524 private:
525 volatile int _jvmti_env_iteration_count;
527 public:
528 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
529 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
530 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
532 // Code generation
533 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file ); }
534 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line ); }
535 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles ); }
537 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base ); }
538 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size ); }
540 #define TLAB_FIELD_OFFSET(name) \
541 static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
543 TLAB_FIELD_OFFSET(start)
544 TLAB_FIELD_OFFSET(end)
545 TLAB_FIELD_OFFSET(top)
546 TLAB_FIELD_OFFSET(pf_top)
547 TLAB_FIELD_OFFSET(size) // desired_size
548 TLAB_FIELD_OFFSET(refill_waste_limit)
549 TLAB_FIELD_OFFSET(number_of_refills)
550 TLAB_FIELD_OFFSET(fast_refill_waste)
551 TLAB_FIELD_OFFSET(slow_allocations)
553 #undef TLAB_FIELD_OFFSET
555 public:
556 volatile intptr_t _Stalled ;
557 volatile int _TypeTag ;
558 ParkEvent * _ParkEvent ; // for synchronized()
559 ParkEvent * _SleepEvent ; // for Thread.sleep
560 ParkEvent * _MutexEvent ; // for native internal Mutex/Monitor
561 ParkEvent * _MuxEvent ; // for low-level muxAcquire-muxRelease
562 int NativeSyncRecursion ; // diagnostic
564 volatile int _OnTrap ; // Resume-at IP delta
565 jint _hashStateW ; // Marsaglia Shift-XOR thread-local RNG
566 jint _hashStateX ; // thread-specific hashCode generator state
567 jint _hashStateY ;
568 jint _hashStateZ ;
569 void * _schedctl ;
571 intptr_t _ScratchA, _ScratchB ; // Scratch locations for fast-path sync code
572 static ByteSize ScratchA_offset() { return byte_offset_of(Thread, _ScratchA ); }
573 static ByteSize ScratchB_offset() { return byte_offset_of(Thread, _ScratchB ); }
575 volatile jint rng [4] ; // RNG for spin loop
577 // Low-level leaf-lock primitives used to implement synchronization
578 // and native monitor-mutex infrastructure.
579 // Not for general synchronization use.
580 static void SpinAcquire (volatile int * Lock, const char * Name) ;
581 static void SpinRelease (volatile int * Lock) ;
582 static void muxAcquire (volatile intptr_t * Lock, const char * Name) ;
583 static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ;
584 static void muxRelease (volatile intptr_t * Lock) ;
585 };
587 // Inline implementation of Thread::current()
588 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
589 // startup.
590 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
591 // period. This is inlined in thread_<os_family>.inline.hpp.
593 inline Thread* Thread::current() {
594 #ifdef ASSERT
595 // This function is very high traffic. Define PARANOID to enable expensive
596 // asserts.
597 #ifdef PARANOID
598 // Signal handler should call ThreadLocalStorage::get_thread_slow()
599 Thread* t = ThreadLocalStorage::get_thread_slow();
600 assert(t != NULL && !t->is_inside_signal_handler(),
601 "Don't use Thread::current() inside signal handler");
602 #endif
603 #endif
604 Thread* thread = ThreadLocalStorage::thread();
605 assert(thread != NULL, "just checking");
606 return thread;
607 }
609 // Name support for threads. non-JavaThread subclasses with multiple
610 // uniquely named instances should derive from this.
611 class NamedThread: public Thread {
612 friend class VMStructs;
613 enum {
614 max_name_len = 64
615 };
616 private:
617 char* _name;
618 // log JavaThread being processed by oops_do
619 JavaThread* _processed_thread;
621 public:
622 NamedThread();
623 ~NamedThread();
624 // May only be called once per thread.
625 void set_name(const char* format, ...);
626 virtual bool is_Named_thread() const { return true; }
627 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
628 JavaThread *processed_thread() { return _processed_thread; }
629 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
630 };
632 // Worker threads are named and have an id of an assigned work.
633 class WorkerThread: public NamedThread {
634 private:
635 uint _id;
636 public:
637 WorkerThread() : _id(0) { }
638 virtual bool is_Worker_thread() const { return true; }
640 virtual WorkerThread* as_Worker_thread() const {
641 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
642 return (WorkerThread*) this;
643 }
645 void set_id(uint work_id) { _id = work_id; }
646 uint id() const { return _id; }
647 };
649 // A single WatcherThread is used for simulating timer interrupts.
650 class WatcherThread: public Thread {
651 friend class VMStructs;
652 public:
653 virtual void run();
655 private:
656 static WatcherThread* _watcher_thread;
658 volatile static bool _should_terminate; // updated without holding lock
659 public:
660 enum SomeConstants {
661 delay_interval = 10 // interrupt delay in milliseconds
662 };
664 // Constructor
665 WatcherThread();
667 // Tester
668 bool is_Watcher_thread() const { return true; }
670 // Printing
671 char* name() const { return (char*)"VM Periodic Task Thread"; }
672 void print_on(outputStream* st) const;
673 void print() const { print_on(tty); }
675 // Returns the single instance of WatcherThread
676 static WatcherThread* watcher_thread() { return _watcher_thread; }
678 // Create and start the single instance of WatcherThread, or stop it on shutdown
679 static void start();
680 static void stop();
681 };
684 class CompilerThread;
686 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
688 class JavaThread: public Thread {
689 friend class VMStructs;
690 private:
691 JavaThread* _next; // The next thread in the Threads list
692 oop _threadObj; // The Java level thread object
694 #ifdef ASSERT
695 private:
696 int _java_call_counter;
698 public:
699 int java_call_counter() { return _java_call_counter; }
700 void inc_java_call_counter() { _java_call_counter++; }
701 void dec_java_call_counter() {
702 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
703 _java_call_counter--;
704 }
705 private: // restore original namespace restriction
706 #endif // ifdef ASSERT
708 #ifndef PRODUCT
709 public:
710 enum {
711 jump_ring_buffer_size = 16
712 };
713 private: // restore original namespace restriction
714 #endif
716 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
718 ThreadFunction _entry_point;
720 JNIEnv _jni_environment;
722 // Deopt support
723 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
725 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
726 // transition out of native
727 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
728 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
729 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
730 // Because deoptimization is lazy we must save jvmti requests to set locals
731 // in compiled frames until we deoptimize and we have an interpreter frame.
732 // This holds the pointer to array (yeah like there might be more than one) of
733 // description of compiled vframes that have locals that need to be updated.
734 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
736 // Handshake value for fixing 6243940. We need a place for the i2c
737 // adapter to store the callee methodOop. This value is NEVER live
738 // across a gc point so it does NOT have to be gc'd
739 // The handshake is open ended since we can't be certain that it will
740 // be NULLed. This is because we rarely ever see the race and end up
741 // in handle_wrong_method which is the backend of the handshake. See
742 // code in i2c adapters and handle_wrong_method.
744 methodOop _callee_target;
746 // Oop results of VM runtime calls
747 oop _vm_result; // Used to pass back an oop result into Java code, GC-preserved
748 oop _vm_result_2; // Used to pass back an oop result into Java code, GC-preserved
750 // See ReduceInitialCardMarks: this holds the precise space interval of
751 // the most recent slow path allocation for which compiled code has
752 // elided card-marks for performance along the fast-path.
753 MemRegion _deferred_card_mark;
755 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
756 // allocated during deoptimization
757 // and by JNI_MonitorEnter/Exit
759 // Async. requests support
760 enum AsyncRequests {
761 _no_async_condition = 0,
762 _async_exception,
763 _async_unsafe_access_error
764 };
765 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
766 oop _pending_async_exception;
768 // Safepoint support
769 public: // Expose _thread_state for SafeFetchInt()
770 volatile JavaThreadState _thread_state;
771 private:
772 ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint
773 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
775 // JavaThread termination support
776 enum TerminatedTypes {
777 _not_terminated = 0xDEAD - 2,
778 _thread_exiting, // JavaThread::exit() has been called for this thread
779 _thread_terminated, // JavaThread is removed from thread list
780 _vm_exited // JavaThread is still executing native code, but VM is terminated
781 // only VM_Exit can set _vm_exited
782 };
784 // In general a JavaThread's _terminated field transitions as follows:
785 //
786 // _not_terminated => _thread_exiting => _thread_terminated
787 //
788 // _vm_exited is a special value to cover the case of a JavaThread
789 // executing native code after the VM itself is terminated.
790 TerminatedTypes _terminated;
791 // suspend/resume support
792 volatile bool _suspend_equivalent; // Suspend equivalent condition
793 jint _in_deopt_handler; // count of deoptimization
794 // handlers thread is in
795 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
796 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
797 // never locked) when throwing an exception. Used by interpreter only.
799 // Flag to mark a JNI thread in the process of attaching - See CR 6404306
800 // This flag is never set true other than at construction, and in that case
801 // is shortly thereafter set false
802 volatile bool _is_attaching;
804 public:
805 // State of the stack guard pages for this thread.
806 enum StackGuardState {
807 stack_guard_unused, // not needed
808 stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
809 stack_guard_enabled // enabled
810 };
812 private:
814 StackGuardState _stack_guard_state;
816 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
817 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
818 // code)
819 volatile oop _exception_oop; // Exception thrown in compiled code
820 volatile address _exception_pc; // PC where exception happened
821 volatile address _exception_handler_pc; // PC for handler of exception
822 volatile int _exception_stack_size; // Size of frame where exception happened
823 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
825 // support for compilation
826 bool _is_compiling; // is true if a compilation is active inthis thread (one compilation per thread possible)
828 // support for JNI critical regions
829 jint _jni_active_critical; // count of entries into JNI critical region
831 // For deadlock detection.
832 int _depth_first_number;
834 // JVMTI PopFrame support
835 // This is set to popframe_pending to signal that top Java frame should be popped immediately
836 int _popframe_condition;
838 #ifndef PRODUCT
839 int _jmp_ring_index;
840 struct {
841 // We use intptr_t instead of address so debugger doesn't try and display strings
842 intptr_t _target;
843 intptr_t _instruction;
844 const char* _file;
845 int _line;
846 } _jmp_ring[ jump_ring_buffer_size ];
847 #endif /* PRODUCT */
849 #ifndef SERIALGC
850 // Support for G1 barriers
852 ObjPtrQueue _satb_mark_queue; // Thread-local log for SATB barrier.
853 // Set of all such queues.
854 static SATBMarkQueueSet _satb_mark_queue_set;
856 DirtyCardQueue _dirty_card_queue; // Thread-local log for dirty cards.
857 // Set of all such queues.
858 static DirtyCardQueueSet _dirty_card_queue_set;
860 void flush_barrier_queues();
861 #endif // !SERIALGC
863 friend class VMThread;
864 friend class ThreadWaitTransition;
865 friend class VM_Exit;
867 void initialize(); // Initialized the instance variables
869 public:
870 // Constructor
871 JavaThread(bool is_attaching = false); // for main thread and JNI attached threads
872 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
873 ~JavaThread();
875 #ifdef ASSERT
876 // verify this JavaThread hasn't be published in the Threads::list yet
877 void verify_not_published();
878 #endif
880 //JNI functiontable getter/setter for JVMTI jni function table interception API.
881 void set_jni_functions(struct JNINativeInterface_* functionTable) {
882 _jni_environment.functions = functionTable;
883 }
884 struct JNINativeInterface_* get_jni_functions() {
885 return (struct JNINativeInterface_ *)_jni_environment.functions;
886 }
888 // This function is called at thread creation to allow
889 // platform specific thread variables to be initialized.
890 void cache_global_variables();
892 // Executes Shutdown.shutdown()
893 void invoke_shutdown_hooks();
895 // Cleanup on thread exit
896 enum ExitType {
897 normal_exit,
898 jni_detach
899 };
900 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
902 void cleanup_failed_attach_current_thread();
904 // Testers
905 virtual bool is_Java_thread() const { return true; }
907 // compilation
908 void set_is_compiling(bool f) { _is_compiling = f; }
909 bool is_compiling() const { return _is_compiling; }
911 // Thread chain operations
912 JavaThread* next() const { return _next; }
913 void set_next(JavaThread* p) { _next = p; }
915 // Thread oop. threadObj() can be NULL for initial JavaThread
916 // (or for threads attached via JNI)
917 oop threadObj() const { return _threadObj; }
918 void set_threadObj(oop p) { _threadObj = p; }
920 ThreadPriority java_priority() const; // Read from threadObj()
922 // Prepare thread and add to priority queue. If a priority is
923 // not specified, use the priority of the thread object. Threads_lock
924 // must be held while this function is called.
925 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
927 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
928 address saved_exception_pc() { return _saved_exception_pc; }
931 ThreadFunction entry_point() const { return _entry_point; }
933 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
934 void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS);
936 // Last frame anchor routines
938 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
940 // last_Java_sp
941 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
942 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
944 // last_Java_pc
946 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
948 // Safepoint support
949 JavaThreadState thread_state() const { return _thread_state; }
950 void set_thread_state(JavaThreadState s) { _thread_state=s; }
951 ThreadSafepointState *safepoint_state() const { return _safepoint_state; }
952 void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
953 bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); }
955 // thread has called JavaThread::exit() or is terminated
956 bool is_exiting() { return _terminated == _thread_exiting || is_terminated(); }
957 // thread is terminated (no longer on the threads list); we compare
958 // against the two non-terminated values so that a freed JavaThread
959 // will also be considered terminated.
960 bool is_terminated() { return _terminated != _not_terminated && _terminated != _thread_exiting; }
961 void set_terminated(TerminatedTypes t) { _terminated = t; }
962 // special for Threads::remove() which is static:
963 void set_terminated_value() { _terminated = _thread_terminated; }
964 void block_if_vm_exited();
966 bool doing_unsafe_access() { return _doing_unsafe_access; }
967 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
969 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
970 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
973 // Suspend/resume support for JavaThread
975 private:
976 void set_ext_suspended() { set_suspend_flag (_ext_suspended); }
977 void clear_ext_suspended() { clear_suspend_flag(_ext_suspended); }
979 public:
980 void java_suspend();
981 void java_resume();
982 int java_suspend_self();
984 void check_and_wait_while_suspended() {
985 assert(JavaThread::current() == this, "sanity check");
987 bool do_self_suspend;
988 do {
989 // were we externally suspended while we were waiting?
990 do_self_suspend = handle_special_suspend_equivalent_condition();
991 if (do_self_suspend) {
992 // don't surprise the thread that suspended us by returning
993 java_suspend_self();
994 set_suspend_equivalent();
995 }
996 } while (do_self_suspend);
997 }
998 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
999 // Check for async exception in addition to safepoint and suspend request.
1000 static void check_special_condition_for_native_trans(JavaThread *thread);
1002 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1003 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1004 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1005 // Warning: is_ext_suspend_completed() may temporarily drop the
1006 // SR_lock to allow the thread to reach a stable thread state if
1007 // it is currently in a transient thread state.
1008 return is_ext_suspend_completed(false /*!called_by_wait */,
1009 SuspendRetryDelay, bits);
1010 }
1012 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1013 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1014 // passed as the count and delay parameters. Experiments with specific
1015 // calls to wait_for_ext_suspend_completion() can be done by passing
1016 // other values in the code. Experiments with all calls can be done
1017 // via the appropriate -XX options.
1018 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1020 void set_external_suspend() { set_suspend_flag (_external_suspend); }
1021 void clear_external_suspend() { clear_suspend_flag(_external_suspend); }
1023 void set_deopt_suspend() { set_suspend_flag (_deopt_suspend); }
1024 void clear_deopt_suspend() { clear_suspend_flag(_deopt_suspend); }
1025 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1027 bool is_external_suspend() const {
1028 return (_suspend_flags & _external_suspend) != 0;
1029 }
1030 // Whenever a thread transitions from native to vm/java it must suspend
1031 // if external|deopt suspend is present.
1032 bool is_suspend_after_native() const {
1033 return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0;
1034 }
1036 // external suspend request is completed
1037 bool is_ext_suspended() const {
1038 return (_suspend_flags & _ext_suspended) != 0;
1039 }
1041 bool is_external_suspend_with_lock() const {
1042 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1043 return is_external_suspend();
1044 }
1046 // Special method to handle a pending external suspend request
1047 // when a suspend equivalent condition lifts.
1048 bool handle_special_suspend_equivalent_condition() {
1049 assert(is_suspend_equivalent(),
1050 "should only be called in a suspend equivalence condition");
1051 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1052 bool ret = is_external_suspend();
1053 if (!ret) {
1054 // not about to self-suspend so clear suspend equivalence
1055 clear_suspend_equivalent();
1056 }
1057 // implied else:
1058 // We have a pending external suspend request so we leave the
1059 // suspend_equivalent flag set until java_suspend_self() sets
1060 // the ext_suspended flag and clears the suspend_equivalent
1061 // flag. This insures that wait_for_ext_suspend_completion()
1062 // will return consistent values.
1063 return ret;
1064 }
1066 // utility methods to see if we are doing some kind of suspension
1067 bool is_being_ext_suspended() const {
1068 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1069 return is_ext_suspended() || is_external_suspend();
1070 }
1072 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1074 void set_suspend_equivalent() { _suspend_equivalent = true; };
1075 void clear_suspend_equivalent() { _suspend_equivalent = false; };
1077 // Thread.stop support
1078 void send_thread_stop(oop throwable);
1079 AsyncRequests clear_special_runtime_exit_condition() {
1080 AsyncRequests x = _special_runtime_exit_condition;
1081 _special_runtime_exit_condition = _no_async_condition;
1082 return x;
1083 }
1085 // Are any async conditions present?
1086 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1088 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1090 // these next two are also used for self-suspension and async exception support
1091 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1093 // Return true if JavaThread has an asynchronous condition or
1094 // if external suspension is requested.
1095 bool has_special_runtime_exit_condition() {
1096 // We call is_external_suspend() last since external suspend should
1097 // be less common. Because we don't use is_external_suspend_with_lock
1098 // it is possible that we won't see an asynchronous external suspend
1099 // request that has just gotten started, i.e., SR_lock grabbed but
1100 // _external_suspend field change either not made yet or not visible
1101 // yet. However, this is okay because the request is asynchronous and
1102 // we will see the new flag value the next time through. It's also
1103 // possible that the external suspend request is dropped after
1104 // we have checked is_external_suspend(), we will recheck its value
1105 // under SR_lock in java_suspend_self().
1106 return (_special_runtime_exit_condition != _no_async_condition) ||
1107 is_external_suspend() || is_deopt_suspend();
1108 }
1110 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1112 void set_pending_async_exception(oop e) {
1113 _pending_async_exception = e;
1114 _special_runtime_exit_condition = _async_exception;
1115 set_has_async_exception();
1116 }
1118 // Fast-locking support
1119 bool is_lock_owned(address adr) const;
1121 // Accessors for vframe array top
1122 // The linked list of vframe arrays are sorted on sp. This means when we
1123 // unpack the head must contain the vframe array to unpack.
1124 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1125 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1127 // Side structure for defering update of java frame locals until deopt occurs
1128 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1129 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1131 // These only really exist to make debugging deopt problems simpler
1133 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1134 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1136 // The special resourceMark used during deoptimization
1138 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1139 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1141 intptr_t* must_deopt_id() { return _must_deopt_id; }
1142 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1143 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1145 void set_deopt_nmethod(nmethod* nm) { _deopt_nmethod = nm; }
1146 nmethod* deopt_nmethod() { return _deopt_nmethod; }
1148 methodOop callee_target() const { return _callee_target; }
1149 void set_callee_target (methodOop x) { _callee_target = x; }
1151 // Oop results of vm runtime calls
1152 oop vm_result() const { return _vm_result; }
1153 void set_vm_result (oop x) { _vm_result = x; }
1155 oop vm_result_2() const { return _vm_result_2; }
1156 void set_vm_result_2 (oop x) { _vm_result_2 = x; }
1158 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1159 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1161 // Exception handling for compiled methods
1162 oop exception_oop() const { return _exception_oop; }
1163 int exception_stack_size() const { return _exception_stack_size; }
1164 address exception_pc() const { return _exception_pc; }
1165 address exception_handler_pc() const { return _exception_handler_pc; }
1166 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1168 void set_exception_oop(oop o) { _exception_oop = o; }
1169 void set_exception_pc(address a) { _exception_pc = a; }
1170 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1171 void set_exception_stack_size(int size) { _exception_stack_size = size; }
1172 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1174 // Stack overflow support
1175 inline size_t stack_available(address cur_sp);
1176 address stack_yellow_zone_base()
1177 { return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); }
1178 size_t stack_yellow_zone_size()
1179 { return StackYellowPages * os::vm_page_size(); }
1180 address stack_red_zone_base()
1181 { return (address)(stack_base() - (stack_size() - stack_red_zone_size())); }
1182 size_t stack_red_zone_size()
1183 { return StackRedPages * os::vm_page_size(); }
1184 bool in_stack_yellow_zone(address a)
1185 { return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); }
1186 bool in_stack_red_zone(address a)
1187 { return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); }
1189 void create_stack_guard_pages();
1190 void remove_stack_guard_pages();
1192 void enable_stack_yellow_zone();
1193 void disable_stack_yellow_zone();
1194 void enable_stack_red_zone();
1195 void disable_stack_red_zone();
1197 inline bool stack_yellow_zone_disabled();
1198 inline bool stack_yellow_zone_enabled();
1200 // Attempt to reguard the stack after a stack overflow may have occurred.
1201 // Returns true if (a) guard pages are not needed on this thread, (b) the
1202 // pages are already guarded, or (c) the pages were successfully reguarded.
1203 // Returns false if there is not enough stack space to reguard the pages, in
1204 // which case the caller should unwind a frame and try again. The argument
1205 // should be the caller's (approximate) sp.
1206 bool reguard_stack(address cur_sp);
1207 // Similar to above but see if current stackpoint is out of the guard area
1208 // and reguard if possible.
1209 bool reguard_stack(void);
1211 // Misc. accessors/mutators
1212 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1213 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1214 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1216 #ifndef PRODUCT
1217 void record_jump(address target, address instr, const char* file, int line);
1218 #endif /* PRODUCT */
1220 // For assembly stub generation
1221 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj ); }
1222 #ifndef PRODUCT
1223 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index ); }
1224 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring ); }
1225 #endif /* PRODUCT */
1226 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment ); }
1227 static ByteSize last_Java_sp_offset() {
1228 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1229 }
1230 static ByteSize last_Java_pc_offset() {
1231 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1232 }
1233 static ByteSize frame_anchor_offset() {
1234 return byte_offset_of(JavaThread, _anchor);
1235 }
1236 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target ); }
1237 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result ); }
1238 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2 ); }
1239 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state ); }
1240 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc ); }
1241 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread ); }
1242 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop ); }
1243 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc ); }
1244 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1245 static ByteSize exception_stack_size_offset() { return byte_offset_of(JavaThread, _exception_stack_size); }
1246 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1247 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state ); }
1248 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags ); }
1250 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1251 static ByteSize should_post_on_exceptions_flag_offset() {
1252 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1253 }
1255 #ifndef SERIALGC
1256 static ByteSize satb_mark_queue_offset() { return byte_offset_of(JavaThread, _satb_mark_queue); }
1257 static ByteSize dirty_card_queue_offset() { return byte_offset_of(JavaThread, _dirty_card_queue); }
1258 #endif // !SERIALGC
1260 // Returns the jni environment for this thread
1261 JNIEnv* jni_environment() { return &_jni_environment; }
1263 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1264 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1265 // Only return NULL if thread is off the thread list; starting to
1266 // exit should not return NULL.
1267 if (thread_from_jni_env->is_terminated()) {
1268 thread_from_jni_env->block_if_vm_exited();
1269 return NULL;
1270 } else {
1271 return thread_from_jni_env;
1272 }
1273 }
1275 // JNI critical regions. These can nest.
1276 bool in_critical() { return _jni_active_critical > 0; }
1277 void enter_critical() { assert(Thread::current() == this,
1278 "this must be current thread");
1279 _jni_active_critical++; }
1280 void exit_critical() { assert(Thread::current() == this,
1281 "this must be current thread");
1282 _jni_active_critical--;
1283 assert(_jni_active_critical >= 0,
1284 "JNI critical nesting problem?"); }
1286 // For deadlock detection
1287 int depth_first_number() { return _depth_first_number; }
1288 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1290 private:
1291 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1293 public:
1294 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1295 void add_monitor_chunk(MonitorChunk* chunk);
1296 void remove_monitor_chunk(MonitorChunk* chunk);
1297 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1298 void inc_in_deopt_handler() { _in_deopt_handler++; }
1299 void dec_in_deopt_handler() {
1300 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1301 if (_in_deopt_handler > 0) { // robustness
1302 _in_deopt_handler--;
1303 }
1304 }
1306 private:
1307 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1309 public:
1311 // Frame iteration; calls the function f for all frames on the stack
1312 void frames_do(void f(frame*, const RegisterMap*));
1314 // Memory operations
1315 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1317 // Sweeper operations
1318 void nmethods_do(CodeBlobClosure* cf);
1320 // Memory management operations
1321 void gc_epilogue();
1322 void gc_prologue();
1324 // Misc. operations
1325 char* name() const { return (char*)get_thread_name(); }
1326 void print_on(outputStream* st) const;
1327 void print() const { print_on(tty); }
1328 void print_value();
1329 void print_thread_state_on(outputStream* ) const PRODUCT_RETURN;
1330 void print_thread_state() const PRODUCT_RETURN;
1331 void print_on_error(outputStream* st, char* buf, int buflen) const;
1332 void verify();
1333 const char* get_thread_name() const;
1334 private:
1335 // factor out low-level mechanics for use in both normal and error cases
1336 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1337 public:
1338 const char* get_threadgroup_name() const;
1339 const char* get_parent_name() const;
1341 // Accessing frames
1342 frame last_frame() {
1343 _anchor.make_walkable(this);
1344 return pd_last_frame();
1345 }
1346 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1348 // Returns method at 'depth' java or native frames down the stack
1349 // Used for security checks
1350 klassOop security_get_caller_class(int depth);
1352 // Print stack trace in external format
1353 void print_stack_on(outputStream* st);
1354 void print_stack() { print_stack_on(tty); }
1356 // Print stack traces in various internal formats
1357 void trace_stack() PRODUCT_RETURN;
1358 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1359 void trace_frames() PRODUCT_RETURN;
1361 // Returns the number of stack frames on the stack
1362 int depth() const;
1364 // Function for testing deoptimization
1365 void deoptimize();
1366 void make_zombies();
1368 void deoptimized_wrt_marked_nmethods();
1370 // Profiling operation (see fprofile.cpp)
1371 public:
1372 bool profile_last_Java_frame(frame* fr);
1374 private:
1375 ThreadProfiler* _thread_profiler;
1376 private:
1377 friend class FlatProfiler; // uses both [gs]et_thread_profiler.
1378 friend class FlatProfilerTask; // uses get_thread_profiler.
1379 friend class ThreadProfilerMark; // uses get_thread_profiler.
1380 ThreadProfiler* get_thread_profiler() { return _thread_profiler; }
1381 ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1382 ThreadProfiler* result = _thread_profiler;
1383 _thread_profiler = tp;
1384 return result;
1385 }
1387 // Static operations
1388 public:
1389 // Returns the running thread as a JavaThread
1390 static inline JavaThread* current();
1392 // Returns the active Java thread. Do not use this if you know you are calling
1393 // from a JavaThread, as it's slower than JavaThread::current. If called from
1394 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1395 // operation. You may not want that either.
1396 static JavaThread* active();
1398 inline CompilerThread* as_CompilerThread();
1400 public:
1401 virtual void run();
1402 void thread_main_inner();
1404 private:
1405 // PRIVILEGED STACK
1406 PrivilegedElement* _privileged_stack_top;
1407 GrowableArray<oop>* _array_for_gc;
1408 public:
1410 // Returns the privileged_stack information.
1411 PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; }
1412 void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; }
1413 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1415 public:
1416 // Thread local information maintained by JVMTI.
1417 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1418 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1419 // getter is used to get this JavaThread's JvmtiThreadState if it has
1420 // one which means NULL can be returned. JvmtiThreadState::state_for()
1421 // is used to get the specified JavaThread's JvmtiThreadState if it has
1422 // one or it allocates a new JvmtiThreadState for the JavaThread and
1423 // returns it. JvmtiThreadState::state_for() will return NULL only if
1424 // the specified JavaThread is exiting.
1425 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1426 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1427 void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1428 JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; }
1430 // JVMTI PopFrame support
1431 // Setting and clearing popframe_condition
1432 // All of these enumerated values are bits. popframe_pending
1433 // indicates that a PopFrame() has been requested and not yet been
1434 // completed. popframe_processing indicates that that PopFrame() is in
1435 // the process of being completed. popframe_force_deopt_reexecution_bit
1436 // indicates that special handling is required when returning to a
1437 // deoptimized caller.
1438 enum PopCondition {
1439 popframe_inactive = 0x00,
1440 popframe_pending_bit = 0x01,
1441 popframe_processing_bit = 0x02,
1442 popframe_force_deopt_reexecution_bit = 0x04
1443 };
1444 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1445 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1446 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1447 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1448 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1449 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1450 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1451 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1452 #ifdef CC_INTERP
1453 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1454 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1455 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1456 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1457 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1458 #endif
1460 private:
1461 // Saved incoming arguments to popped frame.
1462 // Used only when popped interpreted frame returns to deoptimized frame.
1463 void* _popframe_preserved_args;
1464 int _popframe_preserved_args_size;
1466 public:
1467 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1468 void* popframe_preserved_args();
1469 ByteSize popframe_preserved_args_size();
1470 WordSize popframe_preserved_args_size_in_words();
1471 void popframe_free_preserved_args();
1474 private:
1475 JvmtiThreadState *_jvmti_thread_state;
1476 JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1478 // Used by the interpreter in fullspeed mode for frame pop, method
1479 // entry, method exit and single stepping support. This field is
1480 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1481 // It can be set to zero asynchronously (i.e., without a VM operation
1482 // or a lock) so we have to be very careful.
1483 int _interp_only_mode;
1485 public:
1486 // used by the interpreter for fullspeed debugging support (see above)
1487 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1488 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1489 int get_interp_only_mode() { return _interp_only_mode; }
1490 void increment_interp_only_mode() { ++_interp_only_mode; }
1491 void decrement_interp_only_mode() { --_interp_only_mode; }
1493 // support for cached flag that indicates whether exceptions need to be posted for this thread
1494 // if this is false, we can avoid deoptimizing when events are thrown
1495 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1496 private:
1497 int _should_post_on_exceptions_flag;
1499 public:
1500 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
1501 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1503 private:
1504 ThreadStatistics *_thread_stat;
1506 public:
1507 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1509 // Return a blocker object for which this thread is blocked parking.
1510 oop current_park_blocker();
1512 private:
1513 static size_t _stack_size_at_create;
1515 public:
1516 static inline size_t stack_size_at_create(void) {
1517 return _stack_size_at_create;
1518 }
1519 static inline void set_stack_size_at_create(size_t value) {
1520 _stack_size_at_create = value;
1521 }
1523 #ifndef SERIALGC
1524 // SATB marking queue support
1525 ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
1526 static SATBMarkQueueSet& satb_mark_queue_set() {
1527 return _satb_mark_queue_set;
1528 }
1530 // Dirty card queue support
1531 DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1532 static DirtyCardQueueSet& dirty_card_queue_set() {
1533 return _dirty_card_queue_set;
1534 }
1535 #endif // !SERIALGC
1537 // This method initializes the SATB and dirty card queues before a
1538 // JavaThread is added to the Java thread list. Right now, we don't
1539 // have to do anything to the dirty card queue (it should have been
1540 // activated when the thread was created), but we have to activate
1541 // the SATB queue if the thread is created while a marking cycle is
1542 // in progress. The activation / de-activation of the SATB queues at
1543 // the beginning / end of a marking cycle is done during safepoints
1544 // so we have to make sure this method is called outside one to be
1545 // able to safely read the active field of the SATB queue set. Right
1546 // now, it is called just before the thread is added to the Java
1547 // thread list in the Threads::add() method. That method is holding
1548 // the Threads_lock which ensures we are outside a safepoint. We
1549 // cannot do the obvious and set the active field of the SATB queue
1550 // when the thread is created given that, in some cases, safepoints
1551 // might happen between the JavaThread constructor being called and the
1552 // thread being added to the Java thread list (an example of this is
1553 // when the structure for the DestroyJavaVM thread is created).
1554 #ifndef SERIALGC
1555 void initialize_queues();
1556 #else // !SERIALGC
1557 void initialize_queues() { }
1558 #endif // !SERIALGC
1560 // Machine dependent stuff
1561 #ifdef TARGET_OS_ARCH_linux_x86
1562 # include "thread_linux_x86.hpp"
1563 #endif
1564 #ifdef TARGET_OS_ARCH_linux_sparc
1565 # include "thread_linux_sparc.hpp"
1566 #endif
1567 #ifdef TARGET_OS_ARCH_linux_zero
1568 # include "thread_linux_zero.hpp"
1569 #endif
1570 #ifdef TARGET_OS_ARCH_solaris_x86
1571 # include "thread_solaris_x86.hpp"
1572 #endif
1573 #ifdef TARGET_OS_ARCH_solaris_sparc
1574 # include "thread_solaris_sparc.hpp"
1575 #endif
1576 #ifdef TARGET_OS_ARCH_windows_x86
1577 # include "thread_windows_x86.hpp"
1578 #endif
1581 public:
1582 void set_blocked_on_compilation(bool value) {
1583 _blocked_on_compilation = value;
1584 }
1586 bool blocked_on_compilation() {
1587 return _blocked_on_compilation;
1588 }
1589 protected:
1590 bool _blocked_on_compilation;
1593 // JSR166 per-thread parker
1594 private:
1595 Parker* _parker;
1596 public:
1597 Parker* parker() { return _parker; }
1599 // Biased locking support
1600 private:
1601 GrowableArray<MonitorInfo*>* _cached_monitor_info;
1602 public:
1603 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1604 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1606 // clearing/querying jni attach status
1607 bool is_attaching() const { return _is_attaching; }
1608 void set_attached() { _is_attaching = false; OrderAccess::fence(); }
1609 private:
1610 // This field is used to determine if a thread has claimed
1611 // a par_id: it is -1 if the thread has not claimed a par_id;
1612 // otherwise its value is the par_id that has been claimed.
1613 int _claimed_par_id;
1614 public:
1615 int get_claimed_par_id() { return _claimed_par_id; }
1616 void set_claimed_par_id(int id) { _claimed_par_id = id;}
1617 };
1619 // Inline implementation of JavaThread::current
1620 inline JavaThread* JavaThread::current() {
1621 Thread* thread = ThreadLocalStorage::thread();
1622 assert(thread != NULL && thread->is_Java_thread(), "just checking");
1623 return (JavaThread*)thread;
1624 }
1626 inline CompilerThread* JavaThread::as_CompilerThread() {
1627 assert(is_Compiler_thread(), "just checking");
1628 return (CompilerThread*)this;
1629 }
1631 inline bool JavaThread::stack_yellow_zone_disabled() {
1632 return _stack_guard_state == stack_guard_yellow_disabled;
1633 }
1635 inline bool JavaThread::stack_yellow_zone_enabled() {
1636 #ifdef ASSERT
1637 if (os::uses_stack_guard_pages()) {
1638 assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use");
1639 }
1640 #endif
1641 return _stack_guard_state == stack_guard_enabled;
1642 }
1644 inline size_t JavaThread::stack_available(address cur_sp) {
1645 // This code assumes java stacks grow down
1646 address low_addr; // Limit on the address for deepest stack depth
1647 if ( _stack_guard_state == stack_guard_unused) {
1648 low_addr = stack_base() - stack_size();
1649 } else {
1650 low_addr = stack_yellow_zone_base();
1651 }
1652 return cur_sp > low_addr ? cur_sp - low_addr : 0;
1653 }
1655 // A JavaThread for low memory detection support
1656 class LowMemoryDetectorThread : public JavaThread {
1657 friend class VMStructs;
1658 public:
1659 LowMemoryDetectorThread(ThreadFunction entry_point) : JavaThread(entry_point) {};
1661 // Hide this thread from external view.
1662 bool is_hidden_from_external_view() const { return true; }
1663 };
1665 // A thread used for Compilation.
1666 class CompilerThread : public JavaThread {
1667 friend class VMStructs;
1668 private:
1669 CompilerCounters* _counters;
1671 ciEnv* _env;
1672 CompileLog* _log;
1673 CompileTask* _task;
1674 CompileQueue* _queue;
1675 BufferBlob* _buffer_blob;
1677 public:
1679 static CompilerThread* current();
1681 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1683 bool is_Compiler_thread() const { return true; }
1684 // Hide this compiler thread from external view.
1685 bool is_hidden_from_external_view() const { return true; }
1687 CompileQueue* queue() { return _queue; }
1688 CompilerCounters* counters() { return _counters; }
1690 // Get/set the thread's compilation environment.
1691 ciEnv* env() { return _env; }
1692 void set_env(ciEnv* env) { _env = env; }
1694 BufferBlob* get_buffer_blob() { return _buffer_blob; }
1695 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; };
1697 // Get/set the thread's logging information
1698 CompileLog* log() { return _log; }
1699 void init_log(CompileLog* log) {
1700 // Set once, for good.
1701 assert(_log == NULL, "set only once");
1702 _log = log;
1703 }
1705 #ifndef PRODUCT
1706 private:
1707 IdealGraphPrinter *_ideal_graph_printer;
1708 public:
1709 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
1710 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
1711 #endif
1713 // Get/set the thread's current task
1714 CompileTask* task() { return _task; }
1715 void set_task(CompileTask* task) { _task = task; }
1716 };
1718 inline CompilerThread* CompilerThread::current() {
1719 return JavaThread::current()->as_CompilerThread();
1720 }
1723 // The active thread queue. It also keeps track of the current used
1724 // thread priorities.
1725 class Threads: AllStatic {
1726 friend class VMStructs;
1727 private:
1728 static JavaThread* _thread_list;
1729 static int _number_of_threads;
1730 static int _number_of_non_daemon_threads;
1731 static int _return_code;
1733 public:
1734 // Thread management
1735 // force_daemon is a concession to JNI, where we may need to add a
1736 // thread to the thread list before allocating its thread object
1737 static void add(JavaThread* p, bool force_daemon = false);
1738 static void remove(JavaThread* p);
1739 static bool includes(JavaThread* p);
1740 static JavaThread* first() { return _thread_list; }
1741 static void threads_do(ThreadClosure* tc);
1743 // Initializes the vm and creates the vm thread
1744 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1745 static void convert_vm_init_libraries_to_agents();
1746 static void create_vm_init_libraries();
1747 static void create_vm_init_agents();
1748 static void shutdown_vm_agents();
1749 static bool destroy_vm();
1750 // Supported VM versions via JNI
1751 // Includes JNI_VERSION_1_1
1752 static jboolean is_supported_jni_version_including_1_1(jint version);
1753 // Does not include JNI_VERSION_1_1
1754 static jboolean is_supported_jni_version(jint version);
1756 // Garbage collection
1757 static void follow_other_roots(void f(oop*));
1759 // Apply "f->do_oop" to all root oops in all threads.
1760 // This version may only be called by sequential code.
1761 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
1762 // This version may be called by sequential or parallel code.
1763 static void possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf);
1764 // This creates a list of GCTasks, one per thread.
1765 static void create_thread_roots_tasks(GCTaskQueue* q);
1766 // This creates a list of GCTasks, one per thread, for marking objects.
1767 static void create_thread_roots_marking_tasks(GCTaskQueue* q);
1769 // Apply "f->do_oop" to roots in all threads that
1770 // are part of compiled frames
1771 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
1773 static void convert_hcode_pointers();
1774 static void restore_hcode_pointers();
1776 // Sweeper
1777 static void nmethods_do(CodeBlobClosure* cf);
1779 static void gc_epilogue();
1780 static void gc_prologue();
1782 // Verification
1783 static void verify();
1784 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
1785 static void print(bool print_stacks, bool internal_format) {
1786 // this function is only used by debug.cpp
1787 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
1788 }
1789 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
1791 // Get Java threads that are waiting to enter a monitor. If doLock
1792 // is true, then Threads_lock is grabbed as needed. Otherwise, the
1793 // VM needs to be at a safepoint.
1794 static GrowableArray<JavaThread*>* get_pending_threads(int count,
1795 address monitor, bool doLock);
1797 // Get owning Java thread from the monitor's owner field. If doLock
1798 // is true, then Threads_lock is grabbed as needed. Otherwise, the
1799 // VM needs to be at a safepoint.
1800 static JavaThread *owning_thread_from_monitor_owner(address owner,
1801 bool doLock);
1803 // Number of threads on the active threads list
1804 static int number_of_threads() { return _number_of_threads; }
1805 // Number of non-daemon threads on the active threads list
1806 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
1808 // Deoptimizes all frames tied to marked nmethods
1809 static void deoptimized_wrt_marked_nmethods();
1811 };
1814 // Thread iterator
1815 class ThreadClosure: public StackObj {
1816 public:
1817 virtual void do_thread(Thread* thread) = 0;
1818 };
1820 class SignalHandlerMark: public StackObj {
1821 private:
1822 Thread* _thread;
1823 public:
1824 SignalHandlerMark(Thread* t) {
1825 _thread = t;
1826 if (_thread) _thread->enter_signal_handler();
1827 }
1828 ~SignalHandlerMark() {
1829 if (_thread) _thread->leave_signal_handler();
1830 _thread = NULL;
1831 }
1832 };
1835 #endif // SHARE_VM_RUNTIME_THREAD_HPP