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 */
24
25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
26 #define SHARE_VM_RUNTIME_THREAD_HPP
27
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/safepoint.hpp"
40 #include "runtime/stubRoutines.hpp"
41 #include "runtime/threadLocalStorage.hpp"
42 #include "runtime/unhandledOops.hpp"
43 #include "utilities/exceptions.hpp"
44 #include "utilities/top.hpp"
45 #ifndef SERIALGC
46 #include "gc_implementation/g1/dirtyCardQueue.hpp"
47 #include "gc_implementation/g1/satbQueue.hpp"
48 #endif
49 #ifdef ZERO
50 #ifdef TARGET_ARCH_zero
51 # include "stack_zero.hpp"
52 #endif
53 #endif
54
55 class ThreadSafepointState;
56 class ThreadProfiler;
57
58 class JvmtiThreadState;
59 class JvmtiGetLoadedClassesClosure;
60 class ThreadStatistics;
61 class ConcurrentLocksDump;
62 class ParkEvent ;
63
64 class ciEnv;
65 class CompileThread;
66 class CompileLog;
67 class CompileTask;
68 class CompileQueue;
69 class CompilerCounters;
70 class vframeArray;
71
72 class DeoptResourceMark;
73 class jvmtiDeferredLocalVariableSet;
74
75 class GCTaskQueue;
76 class ThreadClosure;
77 class IdealGraphPrinter;
78
79 // Class hierarchy
80 // - Thread
81 // - NamedThread
82 // - VMThread
83 // - ConcurrentGCThread
84 // - WorkerThread
85 // - GangWorker
86 // - GCTaskThread
87 // - JavaThread
88 // - WatcherThread
89
90 class Thread: public ThreadShadow {
91 friend class VMStructs;
92 private:
93 // Exception handling
94 // (Note: _pending_exception and friends are in ThreadShadow)
95 //oop _pending_exception; // pending exception for current thread
96 // const char* _exception_file; // file information for exception (debugging only)
97 // int _exception_line; // line information for exception (debugging only)
98
99 // Support for forcing alignment of thread objects for biased locking
100 void* _real_malloc_address;
101 public:
102 void* operator new(size_t size);
103 void operator delete(void* p);
104 private:
105
106 // ***************************************************************
107 // Suspend and resume support
108 // ***************************************************************
109 //
110 // VM suspend/resume no longer exists - it was once used for various
111 // things including safepoints but was deprecated and finally removed
112 // in Java 7. Because VM suspension was considered "internal" Java-level
113 // suspension was considered "external", and this legacy naming scheme
114 // remains.
115 //
116 // External suspend/resume requests come from JVM_SuspendThread,
117 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
118 // ResumeThread. External
119 // suspend requests cause _external_suspend to be set and external
120 // resume requests cause _external_suspend to be cleared.
121 // External suspend requests do not nest on top of other external
122 // suspend requests. The higher level APIs reject suspend requests
123 // for already suspended threads.
124 //
125 // The external_suspend
126 // flag is checked by has_special_runtime_exit_condition() and java thread
127 // will self-suspend when handle_special_runtime_exit_condition() is
128 // called. Most uses of the _thread_blocked state in JavaThreads are
129 // considered the same as being externally suspended; if the blocking
130 // condition lifts, the JavaThread will self-suspend. Other places
131 // where VM checks for external_suspend include:
132 // + mutex granting (do not enter monitors when thread is suspended)
133 // + state transitions from _thread_in_native
134 //
135 // In general, java_suspend() does not wait for an external suspend
136 // request to complete. When it returns, the only guarantee is that
137 // the _external_suspend field is true.
138 //
139 // wait_for_ext_suspend_completion() is used to wait for an external
140 // suspend request to complete. External suspend requests are usually
141 // followed by some other interface call that requires the thread to
142 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
143 // the interface that requires quiescence, we give the JavaThread a
144 // chance to self-suspend before we need it to be quiescent. This
145 // improves overall suspend/query performance.
146 //
147 // _suspend_flags controls the behavior of java_ suspend/resume.
148 // It must be set under the protection of SR_lock. Read from the flag is
149 // OK without SR_lock as long as the value is only used as a hint.
150 // (e.g., check _external_suspend first without lock and then recheck
151 // inside SR_lock and finish the suspension)
152 //
153 // _suspend_flags is also overloaded for other "special conditions" so
154 // that a single check indicates whether any special action is needed
155 // eg. for async exceptions.
156 // -------------------------------------------------------------------
157 // Notes:
158 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
159 // but we still update its value to keep other part of the system (mainly
160 // JVMTI) happy. ThreadState is legacy code (see notes in
161 // osThread.hpp).
162 //
163 // 2. It would be more natural if set_external_suspend() is private and
164 // part of java_suspend(), but that probably would affect the suspend/query
165 // performance. Need more investigation on this.
166 //
167
168 // suspend/resume lock: used for self-suspend
169 Monitor* _SR_lock;
170
171 protected:
172 enum SuspendFlags {
173 // NOTE: avoid using the sign-bit as cc generates different test code
174 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
175
176 _external_suspend = 0x20000000U, // thread is asked to self suspend
177 _ext_suspended = 0x40000000U, // thread has self-suspended
178 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
179
180 _has_async_exception = 0x00000001U // there is a pending async exception
181 };
182
183 // various suspension related flags - atomically updated
184 // overloaded for async exception checking in check_special_condition_for_native_trans.
185 volatile uint32_t _suspend_flags;
186
187 private:
188 int _num_nested_signal;
189
190 public:
191 void enter_signal_handler() { _num_nested_signal++; }
192 void leave_signal_handler() { _num_nested_signal--; }
193 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
194
195 private:
196 // Debug tracing
197 static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN;
198
199 // Active_handles points to a block of handles
200 JNIHandleBlock* _active_handles;
201
202 // One-element thread local free list
203 JNIHandleBlock* _free_handle_block;
204
205 // Point to the last handle mark
206 HandleMark* _last_handle_mark;
207
208 // The parity of the last strong_roots iteration in which this thread was
209 // claimed as a task.
210 jint _oops_do_parity;
211
212 public:
213 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
214 HandleMark* last_handle_mark() const { return _last_handle_mark; }
215 private:
216
217 // debug support for checking if code does allow safepoints or not
218 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
219 // mutex, or blocking on an object synchronizer (Java locking).
220 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
221 // If !allow_allocation(), then an assertion failure will happen during allocation
222 // (Hence, !allow_safepoint() => !allow_allocation()).
223 //
224 // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
225 //
226 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
227 debug_only (int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
228
229 // Used by SkipGCALot class.
230 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
231
232 // Record when GC is locked out via the GC_locker mechanism
233 CHECK_UNHANDLED_OOPS_ONLY(int _gc_locked_out_count;)
234
235 friend class No_Alloc_Verifier;
236 friend class No_Safepoint_Verifier;
237 friend class Pause_No_Safepoint_Verifier;
238 friend class ThreadLocalStorage;
239 friend class GC_locker;
240
241 ThreadLocalAllocBuffer _tlab; // Thread-local eden
242
243 int _vm_operation_started_count; // VM_Operation support
244 int _vm_operation_completed_count; // VM_Operation support
245
246 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
247 // is waiting to lock
248 bool _current_pending_monitor_is_from_java; // locking is from Java code
249
250 // ObjectMonitor on which this thread called Object.wait()
251 ObjectMonitor* _current_waiting_monitor;
252
253 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
254 public:
255 ObjectMonitor * omFreeList ;
256 int omFreeCount ; // length of omFreeList
257 int omFreeProvision ; // reload chunk size
258 ObjectMonitor * omInUseList; // SLL to track monitors in circulation
259 int omInUseCount; // length of omInUseList
260
261 public:
262 enum {
263 is_definitely_current_thread = true
264 };
265
266 // Constructor
267 Thread();
268 virtual ~Thread();
269
270 // initializtion
271 void initialize_thread_local_storage();
272
273 // thread entry point
274 virtual void run();
275
276 // Testers
277 virtual bool is_VM_thread() const { return false; }
278 virtual bool is_Java_thread() const { return false; }
279 // Remove this ifdef when C1 is ported to the compiler interface.
280 virtual bool is_Compiler_thread() const { return false; }
281 virtual bool is_hidden_from_external_view() const { return false; }
282 virtual bool is_jvmti_agent_thread() const { return false; }
283 // True iff the thread can perform GC operations at a safepoint.
284 // Generally will be true only of VM thread and parallel GC WorkGang
285 // threads.
286 virtual bool is_GC_task_thread() const { return false; }
287 virtual bool is_Watcher_thread() const { return false; }
288 virtual bool is_ConcurrentGC_thread() const { return false; }
289 virtual bool is_Named_thread() const { return false; }
290
291 virtual char* name() const { return (char*)"Unknown thread"; }
292
293 // Returns the current thread
294 static inline Thread* current();
295
296 // Common thread operations
297 static void set_priority(Thread* thread, ThreadPriority priority);
298 static ThreadPriority get_priority(const Thread* const thread);
299 static void start(Thread* thread);
300 static void interrupt(Thread* thr);
301 static bool is_interrupted(Thread* thr, bool clear_interrupted);
302
303 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
304 Monitor* SR_lock() const { return _SR_lock; }
305
306 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
307
308 void set_suspend_flag(SuspendFlags f) {
309 assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
310 uint32_t flags;
311 do {
312 flags = _suspend_flags;
313 }
314 while (Atomic::cmpxchg((jint)(flags | f),
315 (volatile jint*)&_suspend_flags,
316 (jint)flags) != (jint)flags);
317 }
318 void clear_suspend_flag(SuspendFlags f) {
319 assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
320 uint32_t flags;
321 do {
322 flags = _suspend_flags;
323 }
324 while (Atomic::cmpxchg((jint)(flags & ~f),
325 (volatile jint*)&_suspend_flags,
326 (jint)flags) != (jint)flags);
327 }
328
329 void set_has_async_exception() {
330 set_suspend_flag(_has_async_exception);
331 }
332 void clear_has_async_exception() {
333 clear_suspend_flag(_has_async_exception);
334 }
335
336 // Support for Unhandled Oop detection
337 #ifdef CHECK_UNHANDLED_OOPS
338 private:
339 UnhandledOops *_unhandled_oops;
340 public:
341 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
342 // Mark oop safe for gc. It may be stack allocated but won't move.
343 void allow_unhandled_oop(oop *op) {
344 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
345 }
346 // Clear oops at safepoint so crashes point to unhandled oop violator
347 void clear_unhandled_oops() {
348 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
349 }
350 bool is_gc_locked_out() { return _gc_locked_out_count > 0; }
351 #endif // CHECK_UNHANDLED_OOPS
352
353 #ifndef PRODUCT
354 bool skip_gcalot() { return _skip_gcalot; }
355 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
356 #endif
357
358 public:
359 // Installs a pending exception to be inserted later
360 static void send_async_exception(oop thread_oop, oop java_throwable);
361
362 // Resource area
363 ResourceArea* resource_area() const { return _resource_area; }
364 void set_resource_area(ResourceArea* area) { _resource_area = area; }
365
366 OSThread* osthread() const { return _osthread; }
367 void set_osthread(OSThread* thread) { _osthread = thread; }
368
369 // JNI handle support
370 JNIHandleBlock* active_handles() const { return _active_handles; }
371 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
372 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
373 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
374
375 // Internal handle support
376 HandleArea* handle_area() const { return _handle_area; }
377 void set_handle_area(HandleArea* area) { _handle_area = area; }
378
379 // Thread-Local Allocation Buffer (TLAB) support
380 ThreadLocalAllocBuffer& tlab() { return _tlab; }
381 void initialize_tlab() {
382 if (UseTLAB) {
383 tlab().initialize();
384 }
385 }
386
387 // VM operation support
388 int vm_operation_ticket() { return ++_vm_operation_started_count; }
389 int vm_operation_completed_count() { return _vm_operation_completed_count; }
390 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
391
392 // For tracking the heavyweight monitor the thread is pending on.
393 ObjectMonitor* current_pending_monitor() {
394 return _current_pending_monitor;
395 }
396 void set_current_pending_monitor(ObjectMonitor* monitor) {
397 _current_pending_monitor = monitor;
398 }
399 void set_current_pending_monitor_is_from_java(bool from_java) {
400 _current_pending_monitor_is_from_java = from_java;
401 }
402 bool current_pending_monitor_is_from_java() {
403 return _current_pending_monitor_is_from_java;
404 }
405
406 // For tracking the ObjectMonitor on which this thread called Object.wait()
407 ObjectMonitor* current_waiting_monitor() {
408 return _current_waiting_monitor;
409 }
410 void set_current_waiting_monitor(ObjectMonitor* monitor) {
411 _current_waiting_monitor = monitor;
412 }
413
414 // GC support
415 // Apply "f->do_oop" to all root oops in "this".
416 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
417 void oops_do(OopClosure* f, CodeBlobClosure* cf);
418
419 // Handles the parallel case for the method below.
420 private:
421 bool claim_oops_do_par_case(int collection_parity);
422 public:
423 // Requires that "collection_parity" is that of the current strong roots
424 // iteration. If "is_par" is false, sets the parity of "this" to
425 // "collection_parity", and returns "true". If "is_par" is true,
426 // uses an atomic instruction to set the current threads parity to
427 // "collection_parity", if it is not already. Returns "true" iff the
428 // calling thread does the update, this indicates that the calling thread
429 // has claimed the thread's stack as a root groop in the current
430 // collection.
431 bool claim_oops_do(bool is_par, int collection_parity) {
432 if (!is_par) {
433 _oops_do_parity = collection_parity;
434 return true;
435 } else {
436 return claim_oops_do_par_case(collection_parity);
437 }
438 }
439
440 // Sweeper support
441 void nmethods_do(CodeBlobClosure* cf);
442
443 // Used by fast lock support
444 virtual bool is_lock_owned(address adr) const;
445
446 // Check if address is in the stack of the thread (not just for locks).
447 // Warning: the method can only be used on the running thread
448 bool is_in_stack(address adr) const;
449
450 // Sets this thread as starting thread. Returns failure if thread
451 // creation fails due to lack of memory, too many threads etc.
452 bool set_as_starting_thread();
453
454 protected:
455 // OS data associated with the thread
456 OSThread* _osthread; // Platform-specific thread information
457
458 // Thread local resource area for temporary allocation within the VM
459 ResourceArea* _resource_area;
460
461 // Thread local handle area for allocation of handles within the VM
462 HandleArea* _handle_area;
463
464 // Support for stack overflow handling, get_thread, etc.
465 address _stack_base;
466 size_t _stack_size;
467 uintptr_t _self_raw_id; // used by get_thread (mutable)
468 int _lgrp_id;
469
470 public:
471 // Stack overflow support
472 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
473
474 void set_stack_base(address base) { _stack_base = base; }
475 size_t stack_size() const { return _stack_size; }
476 void set_stack_size(size_t size) { _stack_size = size; }
477 void record_stack_base_and_size();
478
479 bool on_local_stack(address adr) const {
480 /* QQQ this has knowledge of direction, ought to be a stack method */
481 return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
482 }
483
484 int lgrp_id() const { return _lgrp_id; }
485 void set_lgrp_id(int value) { _lgrp_id = value; }
486
487 // Printing
488 void print_on(outputStream* st) const;
489 void print() const { print_on(tty); }
490 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
491
492 // Debug-only code
493
494 #ifdef ASSERT
495 private:
496 // Deadlock detection support for Mutex locks. List of locks own by thread.
497 Monitor *_owned_locks;
498 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
499 // thus the friendship
500 friend class Mutex;
501 friend class Monitor;
502
503 public:
504 void print_owned_locks_on(outputStream* st) const;
505 void print_owned_locks() const { print_owned_locks_on(tty); }
506 Monitor * owned_locks() const { return _owned_locks; }
507 bool owns_locks() const { return owned_locks() != NULL; }
508 bool owns_locks_but_compiled_lock() const;
509
510 // Deadlock detection
511 bool allow_allocation() { return _allow_allocation_count == 0; }
512 #endif
513
514 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
515
516 private:
517 volatile int _jvmti_env_iteration_count;
518
519 public:
520 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
521 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
522 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
523
524 // Code generation
525 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file ); }
526 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line ); }
527 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles ); }
528
529 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base ); }
530 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size ); }
531
532 #define TLAB_FIELD_OFFSET(name) \
533 static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
534
535 TLAB_FIELD_OFFSET(start)
536 TLAB_FIELD_OFFSET(end)
537 TLAB_FIELD_OFFSET(top)
538 TLAB_FIELD_OFFSET(pf_top)
539 TLAB_FIELD_OFFSET(size) // desired_size
540 TLAB_FIELD_OFFSET(refill_waste_limit)
541 TLAB_FIELD_OFFSET(number_of_refills)
542 TLAB_FIELD_OFFSET(fast_refill_waste)
543 TLAB_FIELD_OFFSET(slow_allocations)
544
545 #undef TLAB_FIELD_OFFSET
546
547 public:
548 volatile intptr_t _Stalled ;
549 volatile int _TypeTag ;
550 ParkEvent * _ParkEvent ; // for synchronized()
551 ParkEvent * _SleepEvent ; // for Thread.sleep
552 ParkEvent * _MutexEvent ; // for native internal Mutex/Monitor
553 ParkEvent * _MuxEvent ; // for low-level muxAcquire-muxRelease
554 int NativeSyncRecursion ; // diagnostic
555
556 volatile int _OnTrap ; // Resume-at IP delta
557 jint _hashStateW ; // Marsaglia Shift-XOR thread-local RNG
558 jint _hashStateX ; // thread-specific hashCode generator state
559 jint _hashStateY ;
560 jint _hashStateZ ;
561 void * _schedctl ;
562
563 intptr_t _ScratchA, _ScratchB ; // Scratch locations for fast-path sync code
564 static ByteSize ScratchA_offset() { return byte_offset_of(Thread, _ScratchA ); }
565 static ByteSize ScratchB_offset() { return byte_offset_of(Thread, _ScratchB ); }
566
567 volatile jint rng [4] ; // RNG for spin loop
568
569 // Low-level leaf-lock primitives used to implement synchronization
570 // and native monitor-mutex infrastructure.
571 // Not for general synchronization use.
572 static void SpinAcquire (volatile int * Lock, const char * Name) ;
573 static void SpinRelease (volatile int * Lock) ;
574 static void muxAcquire (volatile intptr_t * Lock, const char * Name) ;
575 static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ;
576 static void muxRelease (volatile intptr_t * Lock) ;
577
578 };
579
580 // Inline implementation of Thread::current()
581 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
582 // startup.
583 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
584 // period. This is inlined in thread_<os_family>.inline.hpp.
585
586 inline Thread* Thread::current() {
587 #ifdef ASSERT
588 // This function is very high traffic. Define PARANOID to enable expensive
589 // asserts.
590 #ifdef PARANOID
591 // Signal handler should call ThreadLocalStorage::get_thread_slow()
592 Thread* t = ThreadLocalStorage::get_thread_slow();
593 assert(t != NULL && !t->is_inside_signal_handler(),
594 "Don't use Thread::current() inside signal handler");
595 #endif
596 #endif
597 Thread* thread = ThreadLocalStorage::thread();
598 assert(thread != NULL, "just checking");
599 return thread;
600 }
601
602 // Name support for threads. non-JavaThread subclasses with multiple
603 // uniquely named instances should derive from this.
604 class NamedThread: public Thread {
605 friend class VMStructs;
606 enum {
607 max_name_len = 64
608 };
609 private:
610 char* _name;
611 // log JavaThread being processed by oops_do
612 JavaThread* _processed_thread;
613
614 public:
615 NamedThread();
616 ~NamedThread();
617 // May only be called once per thread.
618 void set_name(const char* format, ...);
619 virtual bool is_Named_thread() const { return true; }
620 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
621 JavaThread *processed_thread() { return _processed_thread; }
622 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
623 };
624
625 // Worker threads are named and have an id of an assigned work.
626 class WorkerThread: public NamedThread {
627 private:
628 uint _id;
629 public:
630 WorkerThread() : _id(0) { }
631 void set_id(uint work_id) { _id = work_id; }
632 uint id() const { return _id; }
633 };
634
635 // A single WatcherThread is used for simulating timer interrupts.
636 class WatcherThread: public Thread {
637 friend class VMStructs;
638 public:
639 virtual void run();
640
641 private:
642 static WatcherThread* _watcher_thread;
643
644 volatile static bool _should_terminate; // updated without holding lock
645 public:
646 enum SomeConstants {
647 delay_interval = 10 // interrupt delay in milliseconds
648 };
649
650 // Constructor
651 WatcherThread();
652
653 // Tester
654 bool is_Watcher_thread() const { return true; }
655
656 // Printing
657 char* name() const { return (char*)"VM Periodic Task Thread"; }
658 void print_on(outputStream* st) const;
659 void print() const { print_on(tty); }
660
661 // Returns the single instance of WatcherThread
662 static WatcherThread* watcher_thread() { return _watcher_thread; }
663
664 // Create and start the single instance of WatcherThread, or stop it on shutdown
665 static void start();
666 static void stop();
667 };
668
669
670 class CompilerThread;
671
672 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
673
674 class JavaThread: public Thread {
675 friend class VMStructs;
676 private:
677 JavaThread* _next; // The next thread in the Threads list
678 oop _threadObj; // The Java level thread object
679
680 #ifdef ASSERT
681 private:
682 int _java_call_counter;
683
684 public:
685 int java_call_counter() { return _java_call_counter; }
686 void inc_java_call_counter() { _java_call_counter++; }
687 void dec_java_call_counter() {
688 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
689 _java_call_counter--;
690 }
691 private: // restore original namespace restriction
692 #endif // ifdef ASSERT
693
694 #ifndef PRODUCT
695 public:
696 enum {
697 jump_ring_buffer_size = 16
698 };
699 private: // restore original namespace restriction
700 #endif
701
702 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
703
704 ThreadFunction _entry_point;
705
706 JNIEnv _jni_environment;
707
708 // Deopt support
709 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
710
711 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
712 // transition out of native
713
714 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
715 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
716 // Because deoptimization is lazy we must save jvmti requests to set locals
717 // in compiled frames until we deoptimize and we have an interpreter frame.
718 // This holds the pointer to array (yeah like there might be more than one) of
719 // description of compiled vframes that have locals that need to be updated.
720 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
721
722 // Handshake value for fixing 6243940. We need a place for the i2c
723 // adapter to store the callee methodOop. This value is NEVER live
724 // across a gc point so it does NOT have to be gc'd
725 // The handshake is open ended since we can't be certain that it will
726 // be NULLed. This is because we rarely ever see the race and end up
727 // in handle_wrong_method which is the backend of the handshake. See
728 // code in i2c adapters and handle_wrong_method.
729
730 methodOop _callee_target;
731
732 // Oop results of VM runtime calls
733 oop _vm_result; // Used to pass back an oop result into Java code, GC-preserved
734 oop _vm_result_2; // Used to pass back an oop result into Java code, GC-preserved
735
736 // See ReduceInitialCardMarks: this holds the precise space interval of
737 // the most recent slow path allocation for which compiled code has
738 // elided card-marks for performance along the fast-path.
739 MemRegion _deferred_card_mark;
740
741 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
742 // allocated during deoptimization
743 // and by JNI_MonitorEnter/Exit
744
745 // Async. requests support
746 enum AsyncRequests {
747 _no_async_condition = 0,
748 _async_exception,
749 _async_unsafe_access_error
750 };
751 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
752 oop _pending_async_exception;
753
754 // Safepoint support
755 public: // Expose _thread_state for SafeFetchInt()
756 volatile JavaThreadState _thread_state;
757 private:
758 ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint
759 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
760
761 // JavaThread termination support
762 enum TerminatedTypes {
763 _not_terminated = 0xDEAD - 2,
764 _thread_exiting, // JavaThread::exit() has been called for this thread
765 _thread_terminated, // JavaThread is removed from thread list
766 _vm_exited // JavaThread is still executing native code, but VM is terminated
767 // only VM_Exit can set _vm_exited
768 };
769
770 // In general a JavaThread's _terminated field transitions as follows:
771 //
772 // _not_terminated => _thread_exiting => _thread_terminated
773 //
774 // _vm_exited is a special value to cover the case of a JavaThread
775 // executing native code after the VM itself is terminated.
776 TerminatedTypes _terminated;
777 // suspend/resume support
778 volatile bool _suspend_equivalent; // Suspend equivalent condition
779 jint _in_deopt_handler; // count of deoptimization
780 // handlers thread is in
781 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
782 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
783 // never locked) when throwing an exception. Used by interpreter only.
784
785 // Flag to mark a JNI thread in the process of attaching - See CR 6404306
786 // This flag is never set true other than at construction, and in that case
787 // is shortly thereafter set false
788 volatile bool _is_attaching;
789
790 public:
791 // State of the stack guard pages for this thread.
792 enum StackGuardState {
793 stack_guard_unused, // not needed
794 stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
795 stack_guard_enabled // enabled
796 };
797
798 private:
799
800 StackGuardState _stack_guard_state;
801
802 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
803 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
804 // code)
805 volatile oop _exception_oop; // Exception thrown in compiled code
806 volatile address _exception_pc; // PC where exception happened
807 volatile address _exception_handler_pc; // PC for handler of exception
808 volatile int _exception_stack_size; // Size of frame where exception happened
809 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
810
811 // support for compilation
812 bool _is_compiling; // is true if a compilation is active inthis thread (one compilation per thread possible)
813
814 // support for JNI critical regions
815 jint _jni_active_critical; // count of entries into JNI critical region
816
817 // For deadlock detection.
818 int _depth_first_number;
819
820 // JVMTI PopFrame support
821 // This is set to popframe_pending to signal that top Java frame should be popped immediately
822 int _popframe_condition;
823
824 #ifndef PRODUCT
825 int _jmp_ring_index;
826 struct {
827 // We use intptr_t instead of address so debugger doesn't try and display strings
828 intptr_t _target;
829 intptr_t _instruction;
830 const char* _file;
831 int _line;
832 } _jmp_ring[ jump_ring_buffer_size ];
833 #endif /* PRODUCT */
834
835 #ifndef SERIALGC
836 // Support for G1 barriers
837
838 ObjPtrQueue _satb_mark_queue; // Thread-local log for SATB barrier.
839 // Set of all such queues.
840 static SATBMarkQueueSet _satb_mark_queue_set;
841
842 DirtyCardQueue _dirty_card_queue; // Thread-local log for dirty cards.
843 // Set of all such queues.
844 static DirtyCardQueueSet _dirty_card_queue_set;
845
846 void flush_barrier_queues();
847 #endif // !SERIALGC
848
849 friend class VMThread;
850 friend class ThreadWaitTransition;
851 friend class VM_Exit;
852
853 void initialize(); // Initialized the instance variables
854
855 public:
856 // Constructor
857 JavaThread(bool is_attaching = false); // for main thread and JNI attached threads
858 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
859 ~JavaThread();
860
861 #ifdef ASSERT
862 // verify this JavaThread hasn't be published in the Threads::list yet
863 void verify_not_published();
864 #endif
865
866 //JNI functiontable getter/setter for JVMTI jni function table interception API.
867 void set_jni_functions(struct JNINativeInterface_* functionTable) {
868 _jni_environment.functions = functionTable;
869 }
870 struct JNINativeInterface_* get_jni_functions() {
871 return (struct JNINativeInterface_ *)_jni_environment.functions;
872 }
873
874 // This function is called at thread creation to allow
875 // platform specific thread variables to be initialized.
876 void cache_global_variables();
877
878 // Executes Shutdown.shutdown()
879 void invoke_shutdown_hooks();
880
881 // Cleanup on thread exit
882 enum ExitType {
883 normal_exit,
884 jni_detach
885 };
886 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
887
888 void cleanup_failed_attach_current_thread();
889
890 // Testers
891 virtual bool is_Java_thread() const { return true; }
892
893 // compilation
894 void set_is_compiling(bool f) { _is_compiling = f; }
895 bool is_compiling() const { return _is_compiling; }
896
897 // Thread chain operations
898 JavaThread* next() const { return _next; }
899 void set_next(JavaThread* p) { _next = p; }
900
901 // Thread oop. threadObj() can be NULL for initial JavaThread
902 // (or for threads attached via JNI)
903 oop threadObj() const { return _threadObj; }
904 void set_threadObj(oop p) { _threadObj = p; }
905
906 ThreadPriority java_priority() const; // Read from threadObj()
907
908 // Prepare thread and add to priority queue. If a priority is
909 // not specified, use the priority of the thread object. Threads_lock
910 // must be held while this function is called.
911 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
912
913 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
914 address saved_exception_pc() { return _saved_exception_pc; }
915
916
917 ThreadFunction entry_point() const { return _entry_point; }
918
919 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
920 void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS);
921
922 // Last frame anchor routines
923
924 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
925
926 // last_Java_sp
927 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
928 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
929
930 // last_Java_pc
931
932 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
933
934 // Safepoint support
935 JavaThreadState thread_state() const { return _thread_state; }
936 void set_thread_state(JavaThreadState s) { _thread_state=s; }
937 ThreadSafepointState *safepoint_state() const { return _safepoint_state; }
938 void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
939 bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); }
940
941 // thread has called JavaThread::exit() or is terminated
942 bool is_exiting() { return _terminated == _thread_exiting || is_terminated(); }
943 // thread is terminated (no longer on the threads list); we compare
944 // against the two non-terminated values so that a freed JavaThread
945 // will also be considered terminated.
946 bool is_terminated() { return _terminated != _not_terminated && _terminated != _thread_exiting; }
947 void set_terminated(TerminatedTypes t) { _terminated = t; }
948 // special for Threads::remove() which is static:
949 void set_terminated_value() { _terminated = _thread_terminated; }
950 void block_if_vm_exited();
951
952 bool doing_unsafe_access() { return _doing_unsafe_access; }
953 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
954
955 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
956 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
957
958
959 // Suspend/resume support for JavaThread
960
961 private:
962 void set_ext_suspended() { set_suspend_flag (_ext_suspended); }
963 void clear_ext_suspended() { clear_suspend_flag(_ext_suspended); }
964
965 public:
966 void java_suspend();
967 void java_resume();
968 int java_suspend_self();
969
970 void check_and_wait_while_suspended() {
971 assert(JavaThread::current() == this, "sanity check");
972
973 bool do_self_suspend;
974 do {
975 // were we externally suspended while we were waiting?
976 do_self_suspend = handle_special_suspend_equivalent_condition();
977 if (do_self_suspend) {
978 // don't surprise the thread that suspended us by returning
979 java_suspend_self();
980 set_suspend_equivalent();
981 }
982 } while (do_self_suspend);
983 }
984 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
985 // Check for async exception in addition to safepoint and suspend request.
986 static void check_special_condition_for_native_trans(JavaThread *thread);
987
988 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
989 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
990 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
991 // Warning: is_ext_suspend_completed() may temporarily drop the
992 // SR_lock to allow the thread to reach a stable thread state if
993 // it is currently in a transient thread state.
994 return is_ext_suspend_completed(false /*!called_by_wait */,
995 SuspendRetryDelay, bits);
996 }
997
998 // We cannot allow wait_for_ext_suspend_completion() to run forever or
999 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1000 // passed as the count and delay parameters. Experiments with specific
1001 // calls to wait_for_ext_suspend_completion() can be done by passing
1002 // other values in the code. Experiments with all calls can be done
1003 // via the appropriate -XX options.
1004 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1005
1006 void set_external_suspend() { set_suspend_flag (_external_suspend); }
1007 void clear_external_suspend() { clear_suspend_flag(_external_suspend); }
1008
1009 void set_deopt_suspend() { set_suspend_flag (_deopt_suspend); }
1010 void clear_deopt_suspend() { clear_suspend_flag(_deopt_suspend); }
1011 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1012
1013 bool is_external_suspend() const {
1014 return (_suspend_flags & _external_suspend) != 0;
1015 }
1016 // Whenever a thread transitions from native to vm/java it must suspend
1017 // if external|deopt suspend is present.
1018 bool is_suspend_after_native() const {
1019 return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0;
1020 }
1021
1022 // external suspend request is completed
1023 bool is_ext_suspended() const {
1024 return (_suspend_flags & _ext_suspended) != 0;
1025 }
1026
1027 bool is_external_suspend_with_lock() const {
1028 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1029 return is_external_suspend();
1030 }
1031
1032 // Special method to handle a pending external suspend request
1033 // when a suspend equivalent condition lifts.
1034 bool handle_special_suspend_equivalent_condition() {
1035 assert(is_suspend_equivalent(),
1036 "should only be called in a suspend equivalence condition");
1037 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1038 bool ret = is_external_suspend();
1039 if (!ret) {
1040 // not about to self-suspend so clear suspend equivalence
1041 clear_suspend_equivalent();
1042 }
1043 // implied else:
1044 // We have a pending external suspend request so we leave the
1045 // suspend_equivalent flag set until java_suspend_self() sets
1046 // the ext_suspended flag and clears the suspend_equivalent
1047 // flag. This insures that wait_for_ext_suspend_completion()
1048 // will return consistent values.
1049 return ret;
1050 }
1051
1052 // utility methods to see if we are doing some kind of suspension
1053 bool is_being_ext_suspended() const {
1054 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1055 return is_ext_suspended() || is_external_suspend();
1056 }
1057
1058 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1059
1060 void set_suspend_equivalent() { _suspend_equivalent = true; };
1061 void clear_suspend_equivalent() { _suspend_equivalent = false; };
1062
1063 // Thread.stop support
1064 void send_thread_stop(oop throwable);
1065 AsyncRequests clear_special_runtime_exit_condition() {
1066 AsyncRequests x = _special_runtime_exit_condition;
1067 _special_runtime_exit_condition = _no_async_condition;
1068 return x;
1069 }
1070
1071 // Are any async conditions present?
1072 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1073
1074 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1075
1076 // these next two are also used for self-suspension and async exception support
1077 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1078
1079 // Return true if JavaThread has an asynchronous condition or
1080 // if external suspension is requested.
1081 bool has_special_runtime_exit_condition() {
1082 // We call is_external_suspend() last since external suspend should
1083 // be less common. Because we don't use is_external_suspend_with_lock
1084 // it is possible that we won't see an asynchronous external suspend
1085 // request that has just gotten started, i.e., SR_lock grabbed but
1086 // _external_suspend field change either not made yet or not visible
1087 // yet. However, this is okay because the request is asynchronous and
1088 // we will see the new flag value the next time through. It's also
1089 // possible that the external suspend request is dropped after
1090 // we have checked is_external_suspend(), we will recheck its value
1091 // under SR_lock in java_suspend_self().
1092 return (_special_runtime_exit_condition != _no_async_condition) ||
1093 is_external_suspend() || is_deopt_suspend();
1094 }
1095
1096 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1097
1098 void set_pending_async_exception(oop e) {
1099 _pending_async_exception = e;
1100 _special_runtime_exit_condition = _async_exception;
1101 set_has_async_exception();
1102 }
1103
1104 // Fast-locking support
1105 bool is_lock_owned(address adr) const;
1106
1107 // Accessors for vframe array top
1108 // The linked list of vframe arrays are sorted on sp. This means when we
1109 // unpack the head must contain the vframe array to unpack.
1110 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1111 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1112
1113 // Side structure for defering update of java frame locals until deopt occurs
1114 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1115 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1116
1117 // These only really exist to make debugging deopt problems simpler
1118
1119 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1120 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1121
1122 // The special resourceMark used during deoptimization
1123
1124 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1125 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1126
1127 intptr_t* must_deopt_id() { return _must_deopt_id; }
1128 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1129 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1130
1131 methodOop callee_target() const { return _callee_target; }
1132 void set_callee_target (methodOop x) { _callee_target = x; }
1133
1134 // Oop results of vm runtime calls
1135 oop vm_result() const { return _vm_result; }
1136 void set_vm_result (oop x) { _vm_result = x; }
1137
1138 oop vm_result_2() const { return _vm_result_2; }
1139 void set_vm_result_2 (oop x) { _vm_result_2 = x; }
1140
1141 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1142 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1143
1144 // Exception handling for compiled methods
1145 oop exception_oop() const { return _exception_oop; }
1146 int exception_stack_size() const { return _exception_stack_size; }
1147 address exception_pc() const { return _exception_pc; }
1148 address exception_handler_pc() const { return _exception_handler_pc; }
1149 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1150
1151 void set_exception_oop(oop o) { _exception_oop = o; }
1152 void set_exception_pc(address a) { _exception_pc = a; }
1153 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1154 void set_exception_stack_size(int size) { _exception_stack_size = size; }
1155 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1156
1157 // Stack overflow support
1158 inline size_t stack_available(address cur_sp);
1159 address stack_yellow_zone_base()
1160 { return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); }
1161 size_t stack_yellow_zone_size()
1162 { return StackYellowPages * os::vm_page_size(); }
1163 address stack_red_zone_base()
1164 { return (address)(stack_base() - (stack_size() - stack_red_zone_size())); }
1165 size_t stack_red_zone_size()
1166 { return StackRedPages * os::vm_page_size(); }
1167 bool in_stack_yellow_zone(address a)
1168 { return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); }
1169 bool in_stack_red_zone(address a)
1170 { return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); }
1171
1172 void create_stack_guard_pages();
1173 void remove_stack_guard_pages();
1174
1175 void enable_stack_yellow_zone();
1176 void disable_stack_yellow_zone();
1177 void enable_stack_red_zone();
1178 void disable_stack_red_zone();
1179
1180 inline bool stack_yellow_zone_disabled();
1181 inline bool stack_yellow_zone_enabled();
1182
1183 // Attempt to reguard the stack after a stack overflow may have occurred.
1184 // Returns true if (a) guard pages are not needed on this thread, (b) the
1185 // pages are already guarded, or (c) the pages were successfully reguarded.
1186 // Returns false if there is not enough stack space to reguard the pages, in
1187 // which case the caller should unwind a frame and try again. The argument
1188 // should be the caller's (approximate) sp.
1189 bool reguard_stack(address cur_sp);
1190 // Similar to above but see if current stackpoint is out of the guard area
1191 // and reguard if possible.
1192 bool reguard_stack(void);
1193
1194 // Misc. accessors/mutators
1195 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1196 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1197 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1198
1199 #ifndef PRODUCT
1200 void record_jump(address target, address instr, const char* file, int line);
1201 #endif /* PRODUCT */
1202
1203 // For assembly stub generation
1204 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj ); }
1205 #ifndef PRODUCT
1206 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index ); }
1207 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring ); }
1208 #endif /* PRODUCT */
1209 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment ); }
1210 static ByteSize last_Java_sp_offset() {
1211 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1212 }
1213 static ByteSize last_Java_pc_offset() {
1214 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1215 }
1216 static ByteSize frame_anchor_offset() {
1217 return byte_offset_of(JavaThread, _anchor);
1218 }
1219 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target ); }
1220 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result ); }
1221 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2 ); }
1222 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state ); }
1223 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc ); }
1224 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread ); }
1225 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop ); }
1226 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc ); }
1227 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1228 static ByteSize exception_stack_size_offset() { return byte_offset_of(JavaThread, _exception_stack_size); }
1229 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1230 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state ); }
1231 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags ); }
1232
1233 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1234 static ByteSize should_post_on_exceptions_flag_offset() {
1235 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1236 }
1237
1238 #ifndef SERIALGC
1239 static ByteSize satb_mark_queue_offset() { return byte_offset_of(JavaThread, _satb_mark_queue); }
1240 static ByteSize dirty_card_queue_offset() { return byte_offset_of(JavaThread, _dirty_card_queue); }
1241 #endif // !SERIALGC
1242
1243 // Returns the jni environment for this thread
1244 JNIEnv* jni_environment() { return &_jni_environment; }
1245
1246 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1247 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1248 // Only return NULL if thread is off the thread list; starting to
1249 // exit should not return NULL.
1250 if (thread_from_jni_env->is_terminated()) {
1251 thread_from_jni_env->block_if_vm_exited();
1252 return NULL;
1253 } else {
1254 return thread_from_jni_env;
1255 }
1256 }
1257
1258 // JNI critical regions. These can nest.
1259 bool in_critical() { return _jni_active_critical > 0; }
1260 void enter_critical() { assert(Thread::current() == this,
1261 "this must be current thread");
1262 _jni_active_critical++; }
1263 void exit_critical() { assert(Thread::current() == this,
1264 "this must be current thread");
1265 _jni_active_critical--;
1266 assert(_jni_active_critical >= 0,
1267 "JNI critical nesting problem?"); }
1268
1269 // For deadlock detection
1270 int depth_first_number() { return _depth_first_number; }
1271 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1272
1273 private:
1274 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1275
1276 public:
1277 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1278 void add_monitor_chunk(MonitorChunk* chunk);
1279 void remove_monitor_chunk(MonitorChunk* chunk);
1280 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1281 void inc_in_deopt_handler() { _in_deopt_handler++; }
1282 void dec_in_deopt_handler() {
1283 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1284 if (_in_deopt_handler > 0) { // robustness
1285 _in_deopt_handler--;
1286 }
1287 }
1288
1289 private:
1290 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1291
1292 public:
1293
1294 // Frame iteration; calls the function f for all frames on the stack
1295 void frames_do(void f(frame*, const RegisterMap*));
1296
1297 // Memory operations
1298 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1299
1300 // Sweeper operations
1301 void nmethods_do(CodeBlobClosure* cf);
1302
1303 // Memory management operations
1304 void gc_epilogue();
1305 void gc_prologue();
1306
1307 // Misc. operations
1308 char* name() const { return (char*)get_thread_name(); }
1309 void print_on(outputStream* st) const;
1310 void print() const { print_on(tty); }
1311 void print_value();
1312 void print_thread_state_on(outputStream* ) const PRODUCT_RETURN;
1313 void print_thread_state() const PRODUCT_RETURN;
1314 void print_on_error(outputStream* st, char* buf, int buflen) const;
1315 void verify();
1316 const char* get_thread_name() const;
1317 private:
1318 // factor out low-level mechanics for use in both normal and error cases
1319 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1320 public:
1321 const char* get_threadgroup_name() const;
1322 const char* get_parent_name() const;
1323
1324 // Accessing frames
1325 frame last_frame() {
1326 _anchor.make_walkable(this);
1327 return pd_last_frame();
1328 }
1329 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1330
1331 // Returns method at 'depth' java or native frames down the stack
1332 // Used for security checks
1333 klassOop security_get_caller_class(int depth);
1334
1335 // Print stack trace in external format
1336 void print_stack_on(outputStream* st);
1337 void print_stack() { print_stack_on(tty); }
1338
1339 // Print stack traces in various internal formats
1340 void trace_stack() PRODUCT_RETURN;
1341 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1342 void trace_frames() PRODUCT_RETURN;
1343
1344 // Returns the number of stack frames on the stack
1345 int depth() const;
1346
1347 // Function for testing deoptimization
1348 void deoptimize();
1349 void make_zombies();
1350
1351 void deoptimized_wrt_marked_nmethods();
1352
1353 // Profiling operation (see fprofile.cpp)
1354 public:
1355 bool profile_last_Java_frame(frame* fr);
1356
1357 private:
1358 ThreadProfiler* _thread_profiler;
1359 private:
1360 friend class FlatProfiler; // uses both [gs]et_thread_profiler.
1361 friend class FlatProfilerTask; // uses get_thread_profiler.
1362 friend class ThreadProfilerMark; // uses get_thread_profiler.
1363 ThreadProfiler* get_thread_profiler() { return _thread_profiler; }
1364 ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1365 ThreadProfiler* result = _thread_profiler;
1366 _thread_profiler = tp;
1367 return result;
1368 }
1369
1370 // Static operations
1371 public:
1372 // Returns the running thread as a JavaThread
1373 static inline JavaThread* current();
1374
1375 // Returns the active Java thread. Do not use this if you know you are calling
1376 // from a JavaThread, as it's slower than JavaThread::current. If called from
1377 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1378 // operation. You may not want that either.
1379 static JavaThread* active();
1380
1381 inline CompilerThread* as_CompilerThread();
1382
1383 public:
1384 virtual void run();
1385 void thread_main_inner();
1386
1387 private:
1388 // PRIVILEGED STACK
1389 PrivilegedElement* _privileged_stack_top;
1390 GrowableArray<oop>* _array_for_gc;
1391 public:
1392
1393 // Returns the privileged_stack information.
1394 PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; }
1395 void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; }
1396 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1397
1398 public:
1399 // Thread local information maintained by JVMTI.
1400 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1401 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1402 // getter is used to get this JavaThread's JvmtiThreadState if it has
1403 // one which means NULL can be returned. JvmtiThreadState::state_for()
1404 // is used to get the specified JavaThread's JvmtiThreadState if it has
1405 // one or it allocates a new JvmtiThreadState for the JavaThread and
1406 // returns it. JvmtiThreadState::state_for() will return NULL only if
1407 // the specified JavaThread is exiting.
1408 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1409 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1410 void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1411 JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; }
1412
1413 // JVMTI PopFrame support
1414 // Setting and clearing popframe_condition
1415 // All of these enumerated values are bits. popframe_pending
1416 // indicates that a PopFrame() has been requested and not yet been
1417 // completed. popframe_processing indicates that that PopFrame() is in
1418 // the process of being completed. popframe_force_deopt_reexecution_bit
1419 // indicates that special handling is required when returning to a
1420 // deoptimized caller.
1421 enum PopCondition {
1422 popframe_inactive = 0x00,
1423 popframe_pending_bit = 0x01,
1424 popframe_processing_bit = 0x02,
1425 popframe_force_deopt_reexecution_bit = 0x04
1426 };
1427 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1428 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1429 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1430 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1431 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1432 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1433 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1434 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1435 #ifdef CC_INTERP
1436 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1437 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1438 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1439 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1440 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1441 #endif
1442
1443 private:
1444 // Saved incoming arguments to popped frame.
1445 // Used only when popped interpreted frame returns to deoptimized frame.
1446 void* _popframe_preserved_args;
1447 int _popframe_preserved_args_size;
1448
1449 public:
1450 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1451 void* popframe_preserved_args();
1452 ByteSize popframe_preserved_args_size();
1453 WordSize popframe_preserved_args_size_in_words();
1454 void popframe_free_preserved_args();
1455
1456
1457 private:
1458 JvmtiThreadState *_jvmti_thread_state;
1459 JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1460
1461 // Used by the interpreter in fullspeed mode for frame pop, method
1462 // entry, method exit and single stepping support. This field is
1463 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1464 // It can be set to zero asynchronously (i.e., without a VM operation
1465 // or a lock) so we have to be very careful.
1466 int _interp_only_mode;
1467
1468 public:
1469 // used by the interpreter for fullspeed debugging support (see above)
1470 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1471 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1472 int get_interp_only_mode() { return _interp_only_mode; }
1473 void increment_interp_only_mode() { ++_interp_only_mode; }
1474 void decrement_interp_only_mode() { --_interp_only_mode; }
1475
1476 // support for cached flag that indicates whether exceptions need to be posted for this thread
1477 // if this is false, we can avoid deoptimizing when events are thrown
1478 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1479 private:
1480 int _should_post_on_exceptions_flag;
1481
1482 public:
1483 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
1484 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1485
1486 private:
1487 ThreadStatistics *_thread_stat;
1488
1489 public:
1490 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1491
1492 // Return a blocker object for which this thread is blocked parking.
1493 oop current_park_blocker();
1494
1495 private:
1496 static size_t _stack_size_at_create;
1497
1498 public:
1499 static inline size_t stack_size_at_create(void) {
1500 return _stack_size_at_create;
1501 }
1502 static inline void set_stack_size_at_create(size_t value) {
1503 _stack_size_at_create = value;
1504 }
1505
1506 #ifndef SERIALGC
1507 // SATB marking queue support
1508 ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
1509 static SATBMarkQueueSet& satb_mark_queue_set() {
1510 return _satb_mark_queue_set;
1511 }
1512
1513 // Dirty card queue support
1514 DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1515 static DirtyCardQueueSet& dirty_card_queue_set() {
1516 return _dirty_card_queue_set;
1517 }
1518 #endif // !SERIALGC
1519
1520 // Machine dependent stuff
1521 #ifdef TARGET_OS_ARCH_linux_x86
1522 # include "thread_linux_x86.hpp"
1523 #endif
1524 #ifdef TARGET_OS_ARCH_linux_sparc
1525 # include "thread_linux_sparc.hpp"
1526 #endif
1527 #ifdef TARGET_OS_ARCH_linux_zero
1528 # include "thread_linux_zero.hpp"
1529 #endif
1530 #ifdef TARGET_OS_ARCH_solaris_x86
1531 # include "thread_solaris_x86.hpp"
1532 #endif
1533 #ifdef TARGET_OS_ARCH_solaris_sparc
1534 # include "thread_solaris_sparc.hpp"
1535 #endif
1536 #ifdef TARGET_OS_ARCH_windows_x86
1537 # include "thread_windows_x86.hpp"
1538 #endif
1539
1540
1541 public:
1542 void set_blocked_on_compilation(bool value) {
1543 _blocked_on_compilation = value;
1544 }
1545
1546 bool blocked_on_compilation() {
1547 return _blocked_on_compilation;
1548 }
1549 protected:
1550 bool _blocked_on_compilation;
1551
1552
1553 // JSR166 per-thread parker
1554 private:
1555 Parker* _parker;
1556 public:
1557 Parker* parker() { return _parker; }
1558
1559 // Biased locking support
1560 private:
1561 GrowableArray<MonitorInfo*>* _cached_monitor_info;
1562 public:
1563 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1564 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1565
1566 // clearing/querying jni attach status
1567 bool is_attaching() const { return _is_attaching; }
1568 void set_attached() { _is_attaching = false; OrderAccess::fence(); }
1569 private:
1570 // This field is used to determine if a thread has claimed
1571 // a par_id: it is -1 if the thread has not claimed a par_id;
1572 // otherwise its value is the par_id that has been claimed.
1573 int _claimed_par_id;
1574 public:
1575 int get_claimed_par_id() { return _claimed_par_id; }
1576 void set_claimed_par_id(int id) { _claimed_par_id = id;}
1577 };
1578
1579 // Inline implementation of JavaThread::current
1580 inline JavaThread* JavaThread::current() {
1581 Thread* thread = ThreadLocalStorage::thread();
1582 assert(thread != NULL && thread->is_Java_thread(), "just checking");
1583 return (JavaThread*)thread;
1584 }
1585
1586 inline CompilerThread* JavaThread::as_CompilerThread() {
1587 assert(is_Compiler_thread(), "just checking");
1588 return (CompilerThread*)this;
1589 }
1590
1591 inline bool JavaThread::stack_yellow_zone_disabled() {
1592 return _stack_guard_state == stack_guard_yellow_disabled;
1593 }
1594
1595 inline bool JavaThread::stack_yellow_zone_enabled() {
1596 #ifdef ASSERT
1597 if (os::uses_stack_guard_pages()) {
1598 assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use");
1599 }
1600 #endif
1601 return _stack_guard_state == stack_guard_enabled;
1602 }
1603
1604 inline size_t JavaThread::stack_available(address cur_sp) {
1605 // This code assumes java stacks grow down
1606 address low_addr; // Limit on the address for deepest stack depth
1607 if ( _stack_guard_state == stack_guard_unused) {
1608 low_addr = stack_base() - stack_size();
1609 } else {
1610 low_addr = stack_yellow_zone_base();
1611 }
1612 return cur_sp > low_addr ? cur_sp - low_addr : 0;
1613 }
1614
1615 // A JavaThread for low memory detection support
1616 class LowMemoryDetectorThread : public JavaThread {
1617 friend class VMStructs;
1618 public:
1619 LowMemoryDetectorThread(ThreadFunction entry_point) : JavaThread(entry_point) {};
1620
1621 // Hide this thread from external view.
1622 bool is_hidden_from_external_view() const { return true; }
1623 };
1624
1625 // A thread used for Compilation.
1626 class CompilerThread : public JavaThread {
1627 friend class VMStructs;
1628 private:
1629 CompilerCounters* _counters;
1630
1631 ciEnv* _env;
1632 CompileLog* _log;
1633 CompileTask* _task;
1634 CompileQueue* _queue;
1635 BufferBlob* _buffer_blob;
1636
1637 public:
1638
1639 static CompilerThread* current();
1640
1641 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1642
1643 bool is_Compiler_thread() const { return true; }
1644 // Hide this compiler thread from external view.
1645 bool is_hidden_from_external_view() const { return true; }
1646
1647 CompileQueue* queue() { return _queue; }
1648 CompilerCounters* counters() { return _counters; }
1649
1650 // Get/set the thread's compilation environment.
1651 ciEnv* env() { return _env; }
1652 void set_env(ciEnv* env) { _env = env; }
1653
1654 BufferBlob* get_buffer_blob() { return _buffer_blob; }
1655 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; };
1656
1657 // Get/set the thread's logging information
1658 CompileLog* log() { return _log; }
1659 void init_log(CompileLog* log) {
1660 // Set once, for good.
1661 assert(_log == NULL, "set only once");
1662 _log = log;
1663 }
1664
1665 #ifndef PRODUCT
1666 private:
1667 IdealGraphPrinter *_ideal_graph_printer;
1668 public:
1669 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
1670 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
1671 #endif
1672
1673 // Get/set the thread's current task
1674 CompileTask* task() { return _task; }
1675 void set_task(CompileTask* task) { _task = task; }
1676 };
1677
1678 inline CompilerThread* CompilerThread::current() {
1679 return JavaThread::current()->as_CompilerThread();
1680 }
1681
1682
1683 // The active thread queue. It also keeps track of the current used
1684 // thread priorities.
1685 class Threads: AllStatic {
1686 friend class VMStructs;
1687 private:
1688 static JavaThread* _thread_list;
1689 static int _number_of_threads;
1690 static int _number_of_non_daemon_threads;
1691 static int _return_code;
1692
1693 public:
1694 // Thread management
1695 // force_daemon is a concession to JNI, where we may need to add a
1696 // thread to the thread list before allocating its thread object
1697 static void add(JavaThread* p, bool force_daemon = false);
1698 static void remove(JavaThread* p);
1699 static bool includes(JavaThread* p);
1700 static JavaThread* first() { return _thread_list; }
1701 static void threads_do(ThreadClosure* tc);
1702
1703 // Initializes the vm and creates the vm thread
1704 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1705 static void convert_vm_init_libraries_to_agents();
1706 static void create_vm_init_libraries();
1707 static void create_vm_init_agents();
1708 static void shutdown_vm_agents();
1709 static bool destroy_vm();
1710 // Supported VM versions via JNI
1711 // Includes JNI_VERSION_1_1
1712 static jboolean is_supported_jni_version_including_1_1(jint version);
1713 // Does not include JNI_VERSION_1_1
1714 static jboolean is_supported_jni_version(jint version);
1715
1716 // Garbage collection
1717 static void follow_other_roots(void f(oop*));
1718
1719 // Apply "f->do_oop" to all root oops in all threads.
1720 // This version may only be called by sequential code.
1721 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
1722 // This version may be called by sequential or parallel code.
1723 static void possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf);
1724 // This creates a list of GCTasks, one per thread.
1725 static void create_thread_roots_tasks(GCTaskQueue* q);
1726 // This creates a list of GCTasks, one per thread, for marking objects.
1727 static void create_thread_roots_marking_tasks(GCTaskQueue* q);
1728
1729 // Apply "f->do_oop" to roots in all threads that
1730 // are part of compiled frames
1731 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
1732
1733 static void convert_hcode_pointers();
1734 static void restore_hcode_pointers();
1735
1736 // Sweeper
1737 static void nmethods_do(CodeBlobClosure* cf);
1738
1739 static void gc_epilogue();
1740 static void gc_prologue();
1741
1742 // Verification
1743 static void verify();
1744 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
1745 static void print(bool print_stacks, bool internal_format) {
1746 // this function is only used by debug.cpp
1747 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
1748 }
1749 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
1750
1751 // Get Java threads that are waiting to enter a monitor. If doLock
1752 // is true, then Threads_lock is grabbed as needed. Otherwise, the
1753 // VM needs to be at a safepoint.
1754 static GrowableArray<JavaThread*>* get_pending_threads(int count,
1755 address monitor, bool doLock);
1756
1757 // Get owning Java thread from the monitor's owner field. If doLock
1758 // is true, then Threads_lock is grabbed as needed. Otherwise, the
1759 // VM needs to be at a safepoint.
1760 static JavaThread *owning_thread_from_monitor_owner(address owner,
1761 bool doLock);
1762
1763 // Number of threads on the active threads list
1764 static int number_of_threads() { return _number_of_threads; }
1765 // Number of non-daemon threads on the active threads list
1766 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
1767
1768 // Deoptimizes all frames tied to marked nmethods
1769 static void deoptimized_wrt_marked_nmethods();
1770
1771 };
1772
1773
1774 // Thread iterator
1775 class ThreadClosure: public StackObj {
1776 public:
1777 virtual void do_thread(Thread* thread) = 0;
1778 };
1779
1780 class SignalHandlerMark: public StackObj {
1781 private:
1782 Thread* _thread;
1783 public:
1784 SignalHandlerMark(Thread* t) {
1785 _thread = t;
1786 if (_thread) _thread->enter_signal_handler();
1787 }
1788 ~SignalHandlerMark() {
1789 if (_thread) _thread->leave_signal_handler();
1790 _thread = NULL;
1791 }
1792 };
1793
1794 // ParkEvents are type-stable and immortal.
1795 //
1796 // Lifecycle: Once a ParkEvent is associated with a thread that ParkEvent remains
1797 // associated with the thread for the thread's entire lifetime - the relationship is
1798 // stable. A thread will be associated at most one ParkEvent. When the thread
1799 // expires, the ParkEvent moves to the EventFreeList. New threads attempt to allocate from
1800 // the EventFreeList before creating a new Event. Type-stability frees us from
1801 // worrying about stale Event or Thread references in the objectMonitor subsystem.
1802 // (A reference to ParkEvent is always valid, even though the event may no longer be associated
1803 // with the desired or expected thread. A key aspect of this design is that the callers of
1804 // park, unpark, etc must tolerate stale references and spurious wakeups).
1805 //
1806 // Only the "associated" thread can block (park) on the ParkEvent, although
1807 // any other thread can unpark a reachable parkevent. Park() is allowed to
1808 // return spuriously. In fact park-unpark a really just an optimization to
1809 // avoid unbounded spinning and surrender the CPU to be a polite system citizen.
1810 // A degenerate albeit "impolite" park-unpark implementation could simply return.
1811 // See http://blogs.sun.com/dave for more details.
1812 //
1813 // Eventually I'd like to eliminate Events and ObjectWaiters, both of which serve as
1814 // thread proxies, and simply make the THREAD structure type-stable and persistent.
1815 // Currently, we unpark events associated with threads, but ideally we'd just
1816 // unpark threads.
1817 //
1818 // The base-class, PlatformEvent, is platform-specific while the ParkEvent is
1819 // platform-independent. PlatformEvent provides park(), unpark(), etc., and
1820 // is abstract -- that is, a PlatformEvent should never be instantiated except
1821 // as part of a ParkEvent.
1822 // Equivalently we could have defined a platform-independent base-class that
1823 // exported Allocate(), Release(), etc. The platform-specific class would extend
1824 // that base-class, adding park(), unpark(), etc.
1825 //
1826 // A word of caution: The JVM uses 2 very similar constructs:
1827 // 1. ParkEvent are used for Java-level "monitor" synchronization.
1828 // 2. Parkers are used by JSR166-JUC park-unpark.
1829 //
1830 // We'll want to eventually merge these redundant facilities and use ParkEvent.
1831
1832
1833 class ParkEvent : public os::PlatformEvent {
1834 private:
1835 ParkEvent * FreeNext ;
1836
1837 // Current association
1838 Thread * AssociatedWith ;
1839 intptr_t RawThreadIdentity ; // LWPID etc
1840 volatile int Incarnation ;
1841
1842 // diagnostic : keep track of last thread to wake this thread.
1843 // this is useful for construction of dependency graphs.
1844 void * LastWaker ;
1845
1846 public:
1847 // MCS-CLH list linkage and Native Mutex/Monitor
1848 ParkEvent * volatile ListNext ;
1849 ParkEvent * volatile ListPrev ;
1850 volatile intptr_t OnList ;
1851 volatile int TState ;
1852 volatile int Notified ; // for native monitor construct
1853 volatile int IsWaiting ; // Enqueued on WaitSet
1854
1855
1856 private:
1857 static ParkEvent * volatile FreeList ;
1858 static volatile int ListLock ;
1859
1860 // It's prudent to mark the dtor as "private"
1861 // ensuring that it's not visible outside the package.
1862 // Unfortunately gcc warns about such usage, so
1863 // we revert to the less desirable "protected" visibility.
1864 // The other compilers accept private dtors.
1865
1866 protected: // Ensure dtor is never invoked
1867 ~ParkEvent() { guarantee (0, "invariant") ; }
1868
1869 ParkEvent() : PlatformEvent() {
1870 AssociatedWith = NULL ;
1871 FreeNext = NULL ;
1872 ListNext = NULL ;
1873 ListPrev = NULL ;
1874 OnList = 0 ;
1875 TState = 0 ;
1876 Notified = 0 ;
1877 IsWaiting = 0 ;
1878 }
1879
1880 // We use placement-new to force ParkEvent instances to be
1881 // aligned on 256-byte address boundaries. This ensures that the least
1882 // significant byte of a ParkEvent address is always 0.
1883
1884 void * operator new (size_t sz) ;
1885 void operator delete (void * a) ;
1886
1887 public:
1888 static ParkEvent * Allocate (Thread * t) ;
1889 static void Release (ParkEvent * e) ;
1890 } ;
1891
1892 #endif // SHARE_VM_RUNTIME_THREAD_HPP