Mercurial > hg > graal-compiler
annotate src/share/vm/runtime/thread.cpp @ 62:cd0742ba123c
Merge
author | kamg |
---|---|
date | Thu, 20 Mar 2008 09:17:30 -0500 |
parents | 75b0f3cb1943 5a76ab815e34 |
children | 6d13fcb3663f 37f87013dfd8 |
rev | line source |
---|---|
0 | 1 /* |
2 * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 # include "incls/_precompiled.incl" | |
26 # include "incls/_thread.cpp.incl" | |
27 | |
28 #ifdef DTRACE_ENABLED | |
29 | |
30 // Only bother with this argument setup if dtrace is available | |
31 | |
32 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin); | |
33 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end); | |
34 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t, | |
35 intptr_t, intptr_t, bool); | |
36 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t, | |
37 intptr_t, intptr_t, bool); | |
38 | |
39 #define DTRACE_THREAD_PROBE(probe, javathread) \ | |
40 { \ | |
41 ResourceMark rm(this); \ | |
42 int len = 0; \ | |
43 const char* name = (javathread)->get_thread_name(); \ | |
44 len = strlen(name); \ | |
45 HS_DTRACE_PROBE5(hotspot, thread__##probe, \ | |
46 name, len, \ | |
47 java_lang_Thread::thread_id((javathread)->threadObj()), \ | |
48 (javathread)->osthread()->thread_id(), \ | |
49 java_lang_Thread::is_daemon((javathread)->threadObj())); \ | |
50 } | |
51 | |
52 #else // ndef DTRACE_ENABLED | |
53 | |
54 #define DTRACE_THREAD_PROBE(probe, javathread) | |
55 | |
56 #endif // ndef DTRACE_ENABLED | |
57 | |
58 // Class hierarchy | |
59 // - Thread | |
60 // - VMThread | |
61 // - WatcherThread | |
62 // - ConcurrentMarkSweepThread | |
63 // - JavaThread | |
64 // - CompilerThread | |
65 | |
66 // ======= Thread ======== | |
67 | |
68 // Support for forcing alignment of thread objects for biased locking | |
69 void* Thread::operator new(size_t size) { | |
70 if (UseBiasedLocking) { | |
71 const int alignment = markOopDesc::biased_lock_alignment; | |
72 size_t aligned_size = size + (alignment - sizeof(intptr_t)); | |
73 void* real_malloc_addr = CHeapObj::operator new(aligned_size); | |
74 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment); | |
75 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <= | |
76 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size), | |
77 "JavaThread alignment code overflowed allocated storage"); | |
78 if (TraceBiasedLocking) { | |
79 if (aligned_addr != real_malloc_addr) | |
80 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT, | |
81 real_malloc_addr, aligned_addr); | |
82 } | |
83 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr; | |
84 return aligned_addr; | |
85 } else { | |
86 return CHeapObj::operator new(size); | |
87 } | |
88 } | |
89 | |
90 void Thread::operator delete(void* p) { | |
91 if (UseBiasedLocking) { | |
92 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address; | |
93 CHeapObj::operator delete(real_malloc_addr); | |
94 } else { | |
95 CHeapObj::operator delete(p); | |
96 } | |
97 } | |
98 | |
99 | |
100 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread, | |
101 // JavaThread | |
102 | |
103 | |
104 Thread::Thread() { | |
105 // stack | |
106 _stack_base = NULL; | |
107 _stack_size = 0; | |
108 _self_raw_id = 0; | |
109 _lgrp_id = -1; | |
110 _osthread = NULL; | |
111 | |
112 // allocated data structures | |
113 set_resource_area(new ResourceArea()); | |
114 set_handle_area(new HandleArea(NULL)); | |
115 set_active_handles(NULL); | |
116 set_free_handle_block(NULL); | |
117 set_last_handle_mark(NULL); | |
118 set_osthread(NULL); | |
119 | |
120 // This initial value ==> never claimed. | |
121 _oops_do_parity = 0; | |
122 | |
123 // the handle mark links itself to last_handle_mark | |
124 new HandleMark(this); | |
125 | |
126 // plain initialization | |
127 debug_only(_owned_locks = NULL;) | |
128 debug_only(_allow_allocation_count = 0;) | |
129 NOT_PRODUCT(_allow_safepoint_count = 0;) | |
130 CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;) | |
131 _highest_lock = NULL; | |
132 _jvmti_env_iteration_count = 0; | |
133 _vm_operation_started_count = 0; | |
134 _vm_operation_completed_count = 0; | |
135 _current_pending_monitor = NULL; | |
136 _current_pending_monitor_is_from_java = true; | |
137 _current_waiting_monitor = NULL; | |
138 _num_nested_signal = 0; | |
139 omFreeList = NULL ; | |
140 omFreeCount = 0 ; | |
141 omFreeProvision = 32 ; | |
142 | |
143 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true); | |
144 _suspend_flags = 0; | |
145 | |
146 // thread-specific hashCode stream generator state - Marsaglia shift-xor form | |
147 _hashStateX = os::random() ; | |
148 _hashStateY = 842502087 ; | |
149 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ; | |
150 _hashStateW = 273326509 ; | |
151 | |
152 _OnTrap = 0 ; | |
153 _schedctl = NULL ; | |
154 _Stalled = 0 ; | |
155 _TypeTag = 0x2BAD ; | |
156 | |
157 // Many of the following fields are effectively final - immutable | |
158 // Note that nascent threads can't use the Native Monitor-Mutex | |
159 // construct until the _MutexEvent is initialized ... | |
160 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents | |
161 // we might instead use a stack of ParkEvents that we could provision on-demand. | |
162 // The stack would act as a cache to avoid calls to ParkEvent::Allocate() | |
163 // and ::Release() | |
164 _ParkEvent = ParkEvent::Allocate (this) ; | |
165 _SleepEvent = ParkEvent::Allocate (this) ; | |
166 _MutexEvent = ParkEvent::Allocate (this) ; | |
167 _MuxEvent = ParkEvent::Allocate (this) ; | |
168 | |
169 #ifdef CHECK_UNHANDLED_OOPS | |
170 if (CheckUnhandledOops) { | |
171 _unhandled_oops = new UnhandledOops(this); | |
172 } | |
173 #endif // CHECK_UNHANDLED_OOPS | |
174 #ifdef ASSERT | |
175 if (UseBiasedLocking) { | |
176 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed"); | |
177 assert(this == _real_malloc_address || | |
178 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment), | |
179 "bug in forced alignment of thread objects"); | |
180 } | |
181 #endif /* ASSERT */ | |
182 } | |
183 | |
184 void Thread::initialize_thread_local_storage() { | |
185 // Note: Make sure this method only calls | |
186 // non-blocking operations. Otherwise, it might not work | |
187 // with the thread-startup/safepoint interaction. | |
188 | |
189 // During Java thread startup, safepoint code should allow this | |
190 // method to complete because it may need to allocate memory to | |
191 // store information for the new thread. | |
192 | |
193 // initialize structure dependent on thread local storage | |
194 ThreadLocalStorage::set_thread(this); | |
195 | |
196 // set up any platform-specific state. | |
197 os::initialize_thread(); | |
198 | |
199 } | |
200 | |
201 void Thread::record_stack_base_and_size() { | |
202 set_stack_base(os::current_stack_base()); | |
203 set_stack_size(os::current_stack_size()); | |
204 } | |
205 | |
206 | |
207 Thread::~Thread() { | |
208 // Reclaim the objectmonitors from the omFreeList of the moribund thread. | |
209 ObjectSynchronizer::omFlush (this) ; | |
210 | |
211 // deallocate data structures | |
212 delete resource_area(); | |
213 // since the handle marks are using the handle area, we have to deallocated the root | |
214 // handle mark before deallocating the thread's handle area, | |
215 assert(last_handle_mark() != NULL, "check we have an element"); | |
216 delete last_handle_mark(); | |
217 assert(last_handle_mark() == NULL, "check we have reached the end"); | |
218 | |
219 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads. | |
220 // We NULL out the fields for good hygiene. | |
221 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ; | |
222 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ; | |
223 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ; | |
224 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ; | |
225 | |
226 delete handle_area(); | |
227 | |
228 // osthread() can be NULL, if creation of thread failed. | |
229 if (osthread() != NULL) os::free_thread(osthread()); | |
230 | |
231 delete _SR_lock; | |
232 | |
233 // clear thread local storage if the Thread is deleting itself | |
234 if (this == Thread::current()) { | |
235 ThreadLocalStorage::set_thread(NULL); | |
236 } else { | |
237 // In the case where we're not the current thread, invalidate all the | |
238 // caches in case some code tries to get the current thread or the | |
239 // thread that was destroyed, and gets stale information. | |
240 ThreadLocalStorage::invalidate_all(); | |
241 } | |
242 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();) | |
243 } | |
244 | |
245 // NOTE: dummy function for assertion purpose. | |
246 void Thread::run() { | |
247 ShouldNotReachHere(); | |
248 } | |
249 | |
250 #ifdef ASSERT | |
251 // Private method to check for dangling thread pointer | |
252 void check_for_dangling_thread_pointer(Thread *thread) { | |
253 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(), | |
254 "possibility of dangling Thread pointer"); | |
255 } | |
256 #endif | |
257 | |
258 | |
259 #ifndef PRODUCT | |
260 // Tracing method for basic thread operations | |
261 void Thread::trace(const char* msg, const Thread* const thread) { | |
262 if (!TraceThreadEvents) return; | |
263 ResourceMark rm; | |
264 ThreadCritical tc; | |
265 const char *name = "non-Java thread"; | |
266 int prio = -1; | |
267 if (thread->is_Java_thread() | |
268 && !thread->is_Compiler_thread()) { | |
269 // The Threads_lock must be held to get information about | |
270 // this thread but may not be in some situations when | |
271 // tracing thread events. | |
272 bool release_Threads_lock = false; | |
273 if (!Threads_lock->owned_by_self()) { | |
274 Threads_lock->lock(); | |
275 release_Threads_lock = true; | |
276 } | |
277 JavaThread* jt = (JavaThread *)thread; | |
278 name = (char *)jt->get_thread_name(); | |
279 oop thread_oop = jt->threadObj(); | |
280 if (thread_oop != NULL) { | |
281 prio = java_lang_Thread::priority(thread_oop); | |
282 } | |
283 if (release_Threads_lock) { | |
284 Threads_lock->unlock(); | |
285 } | |
286 } | |
287 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio); | |
288 } | |
289 #endif | |
290 | |
291 | |
292 ThreadPriority Thread::get_priority(const Thread* const thread) { | |
293 trace("get priority", thread); | |
294 ThreadPriority priority; | |
295 // Can return an error! | |
296 (void)os::get_priority(thread, priority); | |
297 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found"); | |
298 return priority; | |
299 } | |
300 | |
301 void Thread::set_priority(Thread* thread, ThreadPriority priority) { | |
302 trace("set priority", thread); | |
303 debug_only(check_for_dangling_thread_pointer(thread);) | |
304 // Can return an error! | |
305 (void)os::set_priority(thread, priority); | |
306 } | |
307 | |
308 | |
309 void Thread::start(Thread* thread) { | |
310 trace("start", thread); | |
311 // Start is different from resume in that its safety is guaranteed by context or | |
312 // being called from a Java method synchronized on the Thread object. | |
313 if (!DisableStartThread) { | |
314 if (thread->is_Java_thread()) { | |
315 // Initialize the thread state to RUNNABLE before starting this thread. | |
316 // Can not set it after the thread started because we do not know the | |
317 // exact thread state at that time. It could be in MONITOR_WAIT or | |
318 // in SLEEPING or some other state. | |
319 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(), | |
320 java_lang_Thread::RUNNABLE); | |
321 } | |
322 os::start_thread(thread); | |
323 } | |
324 } | |
325 | |
326 // Enqueue a VM_Operation to do the job for us - sometime later | |
327 void Thread::send_async_exception(oop java_thread, oop java_throwable) { | |
328 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable); | |
329 VMThread::execute(vm_stop); | |
330 } | |
331 | |
332 | |
333 // | |
334 // Check if an external suspend request has completed (or has been | |
335 // cancelled). Returns true if the thread is externally suspended and | |
336 // false otherwise. | |
337 // | |
338 // The bits parameter returns information about the code path through | |
339 // the routine. Useful for debugging: | |
340 // | |
341 // set in is_ext_suspend_completed(): | |
342 // 0x00000001 - routine was entered | |
343 // 0x00000010 - routine return false at end | |
344 // 0x00000100 - thread exited (return false) | |
345 // 0x00000200 - suspend request cancelled (return false) | |
346 // 0x00000400 - thread suspended (return true) | |
347 // 0x00001000 - thread is in a suspend equivalent state (return true) | |
348 // 0x00002000 - thread is native and walkable (return true) | |
349 // 0x00004000 - thread is native_trans and walkable (needed retry) | |
350 // | |
351 // set in wait_for_ext_suspend_completion(): | |
352 // 0x00010000 - routine was entered | |
353 // 0x00020000 - suspend request cancelled before loop (return false) | |
354 // 0x00040000 - thread suspended before loop (return true) | |
355 // 0x00080000 - suspend request cancelled in loop (return false) | |
356 // 0x00100000 - thread suspended in loop (return true) | |
357 // 0x00200000 - suspend not completed during retry loop (return false) | |
358 // | |
359 | |
360 // Helper class for tracing suspend wait debug bits. | |
361 // | |
362 // 0x00000100 indicates that the target thread exited before it could | |
363 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and | |
364 // 0x00080000 each indicate a cancelled suspend request so they don't | |
365 // count as wait failures either. | |
366 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000) | |
367 | |
368 class TraceSuspendDebugBits : public StackObj { | |
369 private: | |
370 JavaThread * jt; | |
371 bool is_wait; | |
372 bool called_by_wait; // meaningful when !is_wait | |
373 uint32_t * bits; | |
374 | |
375 public: | |
376 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait, | |
377 uint32_t *_bits) { | |
378 jt = _jt; | |
379 is_wait = _is_wait; | |
380 called_by_wait = _called_by_wait; | |
381 bits = _bits; | |
382 } | |
383 | |
384 ~TraceSuspendDebugBits() { | |
385 if (!is_wait) { | |
386 #if 1 | |
387 // By default, don't trace bits for is_ext_suspend_completed() calls. | |
388 // That trace is very chatty. | |
389 return; | |
390 #else | |
391 if (!called_by_wait) { | |
392 // If tracing for is_ext_suspend_completed() is enabled, then only | |
393 // trace calls to it from wait_for_ext_suspend_completion() | |
394 return; | |
395 } | |
396 #endif | |
397 } | |
398 | |
399 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) { | |
400 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) { | |
401 MutexLocker ml(Threads_lock); // needed for get_thread_name() | |
402 ResourceMark rm; | |
403 | |
404 tty->print_cr( | |
405 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)", | |
406 jt->get_thread_name(), *bits); | |
407 | |
408 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed"); | |
409 } | |
410 } | |
411 } | |
412 }; | |
413 #undef DEBUG_FALSE_BITS | |
414 | |
415 | |
416 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) { | |
417 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits); | |
418 | |
419 bool did_trans_retry = false; // only do thread_in_native_trans retry once | |
420 bool do_trans_retry; // flag to force the retry | |
421 | |
422 *bits |= 0x00000001; | |
423 | |
424 do { | |
425 do_trans_retry = false; | |
426 | |
427 if (is_exiting()) { | |
428 // Thread is in the process of exiting. This is always checked | |
429 // first to reduce the risk of dereferencing a freed JavaThread. | |
430 *bits |= 0x00000100; | |
431 return false; | |
432 } | |
433 | |
434 if (!is_external_suspend()) { | |
435 // Suspend request is cancelled. This is always checked before | |
436 // is_ext_suspended() to reduce the risk of a rogue resume | |
437 // confusing the thread that made the suspend request. | |
438 *bits |= 0x00000200; | |
439 return false; | |
440 } | |
441 | |
442 if (is_ext_suspended()) { | |
443 // thread is suspended | |
444 *bits |= 0x00000400; | |
445 return true; | |
446 } | |
447 | |
448 // Now that we no longer do hard suspends of threads running | |
449 // native code, the target thread can be changing thread state | |
450 // while we are in this routine: | |
451 // | |
452 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked | |
453 // | |
454 // We save a copy of the thread state as observed at this moment | |
455 // and make our decision about suspend completeness based on the | |
456 // copy. This closes the race where the thread state is seen as | |
457 // _thread_in_native_trans in the if-thread_blocked check, but is | |
458 // seen as _thread_blocked in if-thread_in_native_trans check. | |
459 JavaThreadState save_state = thread_state(); | |
460 | |
461 if (save_state == _thread_blocked && is_suspend_equivalent()) { | |
462 // If the thread's state is _thread_blocked and this blocking | |
463 // condition is known to be equivalent to a suspend, then we can | |
464 // consider the thread to be externally suspended. This means that | |
465 // the code that sets _thread_blocked has been modified to do | |
466 // self-suspension if the blocking condition releases. We also | |
467 // used to check for CONDVAR_WAIT here, but that is now covered by | |
468 // the _thread_blocked with self-suspension check. | |
469 // | |
470 // Return true since we wouldn't be here unless there was still an | |
471 // external suspend request. | |
472 *bits |= 0x00001000; | |
473 return true; | |
474 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) { | |
475 // Threads running native code will self-suspend on native==>VM/Java | |
476 // transitions. If its stack is walkable (should always be the case | |
477 // unless this function is called before the actual java_suspend() | |
478 // call), then the wait is done. | |
479 *bits |= 0x00002000; | |
480 return true; | |
481 } else if (!called_by_wait && !did_trans_retry && | |
482 save_state == _thread_in_native_trans && | |
483 frame_anchor()->walkable()) { | |
484 // The thread is transitioning from thread_in_native to another | |
485 // thread state. check_safepoint_and_suspend_for_native_trans() | |
486 // will force the thread to self-suspend. If it hasn't gotten | |
487 // there yet we may have caught the thread in-between the native | |
488 // code check above and the self-suspend. Lucky us. If we were | |
489 // called by wait_for_ext_suspend_completion(), then it | |
490 // will be doing the retries so we don't have to. | |
491 // | |
492 // Since we use the saved thread state in the if-statement above, | |
493 // there is a chance that the thread has already transitioned to | |
494 // _thread_blocked by the time we get here. In that case, we will | |
495 // make a single unnecessary pass through the logic below. This | |
496 // doesn't hurt anything since we still do the trans retry. | |
497 | |
498 *bits |= 0x00004000; | |
499 | |
500 // Once the thread leaves thread_in_native_trans for another | |
501 // thread state, we break out of this retry loop. We shouldn't | |
502 // need this flag to prevent us from getting back here, but | |
503 // sometimes paranoia is good. | |
504 did_trans_retry = true; | |
505 | |
506 // We wait for the thread to transition to a more usable state. | |
507 for (int i = 1; i <= SuspendRetryCount; i++) { | |
508 // We used to do an "os::yield_all(i)" call here with the intention | |
509 // that yielding would increase on each retry. However, the parameter | |
510 // is ignored on Linux which means the yield didn't scale up. Waiting | |
511 // on the SR_lock below provides a much more predictable scale up for | |
512 // the delay. It also provides a simple/direct point to check for any | |
513 // safepoint requests from the VMThread | |
514 | |
515 // temporarily drops SR_lock while doing wait with safepoint check | |
516 // (if we're a JavaThread - the WatcherThread can also call this) | |
517 // and increase delay with each retry | |
518 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); | |
519 | |
520 // check the actual thread state instead of what we saved above | |
521 if (thread_state() != _thread_in_native_trans) { | |
522 // the thread has transitioned to another thread state so | |
523 // try all the checks (except this one) one more time. | |
524 do_trans_retry = true; | |
525 break; | |
526 } | |
527 } // end retry loop | |
528 | |
529 | |
530 } | |
531 } while (do_trans_retry); | |
532 | |
533 *bits |= 0x00000010; | |
534 return false; | |
535 } | |
536 | |
537 // | |
538 // Wait for an external suspend request to complete (or be cancelled). | |
539 // Returns true if the thread is externally suspended and false otherwise. | |
540 // | |
541 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay, | |
542 uint32_t *bits) { | |
543 TraceSuspendDebugBits tsdb(this, true /* is_wait */, | |
544 false /* !called_by_wait */, bits); | |
545 | |
546 // local flag copies to minimize SR_lock hold time | |
547 bool is_suspended; | |
548 bool pending; | |
549 uint32_t reset_bits; | |
550 | |
551 // set a marker so is_ext_suspend_completed() knows we are the caller | |
552 *bits |= 0x00010000; | |
553 | |
554 // We use reset_bits to reinitialize the bits value at the top of | |
555 // each retry loop. This allows the caller to make use of any | |
556 // unused bits for their own marking purposes. | |
557 reset_bits = *bits; | |
558 | |
559 { | |
560 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); | |
561 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, | |
562 delay, bits); | |
563 pending = is_external_suspend(); | |
564 } | |
565 // must release SR_lock to allow suspension to complete | |
566 | |
567 if (!pending) { | |
568 // A cancelled suspend request is the only false return from | |
569 // is_ext_suspend_completed() that keeps us from entering the | |
570 // retry loop. | |
571 *bits |= 0x00020000; | |
572 return false; | |
573 } | |
574 | |
575 if (is_suspended) { | |
576 *bits |= 0x00040000; | |
577 return true; | |
578 } | |
579 | |
580 for (int i = 1; i <= retries; i++) { | |
581 *bits = reset_bits; // reinit to only track last retry | |
582 | |
583 // We used to do an "os::yield_all(i)" call here with the intention | |
584 // that yielding would increase on each retry. However, the parameter | |
585 // is ignored on Linux which means the yield didn't scale up. Waiting | |
586 // on the SR_lock below provides a much more predictable scale up for | |
587 // the delay. It also provides a simple/direct point to check for any | |
588 // safepoint requests from the VMThread | |
589 | |
590 { | |
591 MutexLocker ml(SR_lock()); | |
592 // wait with safepoint check (if we're a JavaThread - the WatcherThread | |
593 // can also call this) and increase delay with each retry | |
594 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); | |
595 | |
596 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, | |
597 delay, bits); | |
598 | |
599 // It is possible for the external suspend request to be cancelled | |
600 // (by a resume) before the actual suspend operation is completed. | |
601 // Refresh our local copy to see if we still need to wait. | |
602 pending = is_external_suspend(); | |
603 } | |
604 | |
605 if (!pending) { | |
606 // A cancelled suspend request is the only false return from | |
607 // is_ext_suspend_completed() that keeps us from staying in the | |
608 // retry loop. | |
609 *bits |= 0x00080000; | |
610 return false; | |
611 } | |
612 | |
613 if (is_suspended) { | |
614 *bits |= 0x00100000; | |
615 return true; | |
616 } | |
617 } // end retry loop | |
618 | |
619 // thread did not suspend after all our retries | |
620 *bits |= 0x00200000; | |
621 return false; | |
622 } | |
623 | |
624 #ifndef PRODUCT | |
625 void JavaThread::record_jump(address target, address instr, const char* file, int line) { | |
626 | |
627 // This should not need to be atomic as the only way for simultaneous | |
628 // updates is via interrupts. Even then this should be rare or non-existant | |
629 // and we don't care that much anyway. | |
630 | |
631 int index = _jmp_ring_index; | |
632 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1); | |
633 _jmp_ring[index]._target = (intptr_t) target; | |
634 _jmp_ring[index]._instruction = (intptr_t) instr; | |
635 _jmp_ring[index]._file = file; | |
636 _jmp_ring[index]._line = line; | |
637 } | |
638 #endif /* PRODUCT */ | |
639 | |
640 // Called by flat profiler | |
641 // Callers have already called wait_for_ext_suspend_completion | |
642 // The assertion for that is currently too complex to put here: | |
643 bool JavaThread::profile_last_Java_frame(frame* _fr) { | |
644 bool gotframe = false; | |
645 // self suspension saves needed state. | |
646 if (has_last_Java_frame() && _anchor.walkable()) { | |
647 *_fr = pd_last_frame(); | |
648 gotframe = true; | |
649 } | |
650 return gotframe; | |
651 } | |
652 | |
653 void Thread::interrupt(Thread* thread) { | |
654 trace("interrupt", thread); | |
655 debug_only(check_for_dangling_thread_pointer(thread);) | |
656 os::interrupt(thread); | |
657 } | |
658 | |
659 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) { | |
660 trace("is_interrupted", thread); | |
661 debug_only(check_for_dangling_thread_pointer(thread);) | |
662 // Note: If clear_interrupted==false, this simply fetches and | |
663 // returns the value of the field osthread()->interrupted(). | |
664 return os::is_interrupted(thread, clear_interrupted); | |
665 } | |
666 | |
667 | |
668 // GC Support | |
669 bool Thread::claim_oops_do_par_case(int strong_roots_parity) { | |
670 jint thread_parity = _oops_do_parity; | |
671 if (thread_parity != strong_roots_parity) { | |
672 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity); | |
673 if (res == thread_parity) return true; | |
674 else { | |
675 guarantee(res == strong_roots_parity, "Or else what?"); | |
676 assert(SharedHeap::heap()->n_par_threads() > 0, | |
677 "Should only fail when parallel."); | |
678 return false; | |
679 } | |
680 } | |
681 assert(SharedHeap::heap()->n_par_threads() > 0, | |
682 "Should only fail when parallel."); | |
683 return false; | |
684 } | |
685 | |
686 void Thread::oops_do(OopClosure* f) { | |
687 active_handles()->oops_do(f); | |
688 // Do oop for ThreadShadow | |
689 f->do_oop((oop*)&_pending_exception); | |
690 handle_area()->oops_do(f); | |
691 } | |
692 | |
693 void Thread::nmethods_do() { | |
694 } | |
695 | |
696 void Thread::print_on(outputStream* st) const { | |
697 // get_priority assumes osthread initialized | |
698 if (osthread() != NULL) { | |
699 st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this); | |
700 osthread()->print_on(st); | |
701 } | |
702 debug_only(if (WizardMode) print_owned_locks_on(st);) | |
703 } | |
704 | |
705 // Thread::print_on_error() is called by fatal error handler. Don't use | |
706 // any lock or allocate memory. | |
707 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const { | |
708 if (is_VM_thread()) st->print("VMThread"); | |
709 else if (is_Compiler_thread()) st->print("CompilerThread"); | |
710 else if (is_Java_thread()) st->print("JavaThread"); | |
711 else if (is_GC_task_thread()) st->print("GCTaskThread"); | |
712 else if (is_Watcher_thread()) st->print("WatcherThread"); | |
713 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread"); | |
714 else st->print("Thread"); | |
715 | |
716 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]", | |
717 _stack_base - _stack_size, _stack_base); | |
718 | |
719 if (osthread()) { | |
720 st->print(" [id=%d]", osthread()->thread_id()); | |
721 } | |
722 } | |
723 | |
724 #ifdef ASSERT | |
725 void Thread::print_owned_locks_on(outputStream* st) const { | |
726 Monitor *cur = _owned_locks; | |
727 if (cur == NULL) { | |
728 st->print(" (no locks) "); | |
729 } else { | |
730 st->print_cr(" Locks owned:"); | |
731 while(cur) { | |
732 cur->print_on(st); | |
733 cur = cur->next(); | |
734 } | |
735 } | |
736 } | |
737 | |
738 static int ref_use_count = 0; | |
739 | |
740 bool Thread::owns_locks_but_compiled_lock() const { | |
741 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { | |
742 if (cur != Compile_lock) return true; | |
743 } | |
744 return false; | |
745 } | |
746 | |
747 | |
748 #endif | |
749 | |
750 #ifndef PRODUCT | |
751 | |
752 // The flag: potential_vm_operation notifies if this particular safepoint state could potential | |
753 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that | |
754 // no threads which allow_vm_block's are held | |
755 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) { | |
756 // Check if current thread is allowed to block at a safepoint | |
757 if (!(_allow_safepoint_count == 0)) | |
758 fatal("Possible safepoint reached by thread that does not allow it"); | |
759 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) { | |
760 fatal("LEAF method calling lock?"); | |
761 } | |
762 | |
763 #ifdef ASSERT | |
764 if (potential_vm_operation && is_Java_thread() | |
765 && !Universe::is_bootstrapping()) { | |
766 // Make sure we do not hold any locks that the VM thread also uses. | |
767 // This could potentially lead to deadlocks | |
768 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { | |
769 // Threads_lock is special, since the safepoint synchronization will not start before this is | |
770 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock, | |
771 // since it is used to transfer control between JavaThreads and the VMThread | |
772 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first! | |
773 if ( (cur->allow_vm_block() && | |
774 cur != Threads_lock && | |
775 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation | |
776 cur != VMOperationRequest_lock && | |
777 cur != VMOperationQueue_lock) || | |
778 cur->rank() == Mutex::special) { | |
779 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name()); | |
780 } | |
781 } | |
782 } | |
783 | |
784 if (GCALotAtAllSafepoints) { | |
785 // We could enter a safepoint here and thus have a gc | |
786 InterfaceSupport::check_gc_alot(); | |
787 } | |
788 | |
789 #endif | |
790 } | |
791 #endif | |
792 | |
793 bool Thread::lock_is_in_stack(address adr) const { | |
794 assert(Thread::current() == this, "lock_is_in_stack can only be called from current thread"); | |
795 // High limit: highest_lock is set during thread execution | |
796 // Low limit: address of the local variable dummy, rounded to 4K boundary. | |
797 // (The rounding helps finding threads in unsafe mode, even if the particular stack | |
798 // frame has been popped already. Correct as long as stacks are at least 4K long and aligned.) | |
799 address end = os::current_stack_pointer(); | |
800 if (_highest_lock >= adr && adr >= end) return true; | |
801 | |
802 return false; | |
803 } | |
804 | |
805 | |
806 bool Thread::is_in_stack(address adr) const { | |
807 assert(Thread::current() == this, "is_in_stack can only be called from current thread"); | |
808 address end = os::current_stack_pointer(); | |
809 if (stack_base() >= adr && adr >= end) return true; | |
810 | |
811 return false; | |
812 } | |
813 | |
814 | |
815 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter | |
816 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being | |
817 // used for compilation in the future. If that change is made, the need for these methods | |
818 // should be revisited, and they should be removed if possible. | |
819 | |
820 bool Thread::is_lock_owned(address adr) const { | |
821 if (lock_is_in_stack(adr) ) return true; | |
822 return false; | |
823 } | |
824 | |
825 bool Thread::set_as_starting_thread() { | |
826 // NOTE: this must be called inside the main thread. | |
827 return os::create_main_thread((JavaThread*)this); | |
828 } | |
829 | |
830 static void initialize_class(symbolHandle class_name, TRAPS) { | |
831 klassOop klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK); | |
832 instanceKlass::cast(klass)->initialize(CHECK); | |
833 } | |
834 | |
835 | |
836 // Creates the initial ThreadGroup | |
837 static Handle create_initial_thread_group(TRAPS) { | |
838 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH); | |
839 instanceKlassHandle klass (THREAD, k); | |
840 | |
841 Handle system_instance = klass->allocate_instance_handle(CHECK_NH); | |
842 { | |
843 JavaValue result(T_VOID); | |
844 JavaCalls::call_special(&result, | |
845 system_instance, | |
846 klass, | |
847 vmSymbolHandles::object_initializer_name(), | |
848 vmSymbolHandles::void_method_signature(), | |
849 CHECK_NH); | |
850 } | |
851 Universe::set_system_thread_group(system_instance()); | |
852 | |
853 Handle main_instance = klass->allocate_instance_handle(CHECK_NH); | |
854 { | |
855 JavaValue result(T_VOID); | |
856 Handle string = java_lang_String::create_from_str("main", CHECK_NH); | |
857 JavaCalls::call_special(&result, | |
858 main_instance, | |
859 klass, | |
860 vmSymbolHandles::object_initializer_name(), | |
861 vmSymbolHandles::threadgroup_string_void_signature(), | |
862 system_instance, | |
863 string, | |
864 CHECK_NH); | |
865 } | |
866 return main_instance; | |
867 } | |
868 | |
869 // Creates the initial Thread | |
870 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) { | |
871 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL); | |
872 instanceKlassHandle klass (THREAD, k); | |
873 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL); | |
874 | |
875 java_lang_Thread::set_thread(thread_oop(), thread); | |
876 java_lang_Thread::set_priority(thread_oop(), NormPriority); | |
877 thread->set_threadObj(thread_oop()); | |
878 | |
879 Handle string = java_lang_String::create_from_str("main", CHECK_NULL); | |
880 | |
881 JavaValue result(T_VOID); | |
882 JavaCalls::call_special(&result, thread_oop, | |
883 klass, | |
884 vmSymbolHandles::object_initializer_name(), | |
885 vmSymbolHandles::threadgroup_string_void_signature(), | |
886 thread_group, | |
887 string, | |
888 CHECK_NULL); | |
889 return thread_oop(); | |
890 } | |
891 | |
892 static void call_initializeSystemClass(TRAPS) { | |
893 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK); | |
894 instanceKlassHandle klass (THREAD, k); | |
895 | |
896 JavaValue result(T_VOID); | |
897 JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(), | |
898 vmSymbolHandles::void_method_signature(), CHECK); | |
899 } | |
900 | |
901 static void reset_vm_info_property(TRAPS) { | |
902 // the vm info string | |
903 ResourceMark rm(THREAD); | |
904 const char *vm_info = VM_Version::vm_info_string(); | |
905 | |
906 // java.lang.System class | |
907 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK); | |
908 instanceKlassHandle klass (THREAD, k); | |
909 | |
910 // setProperty arguments | |
911 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK); | |
912 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK); | |
913 | |
914 // return value | |
915 JavaValue r(T_OBJECT); | |
916 | |
917 // public static String setProperty(String key, String value); | |
918 JavaCalls::call_static(&r, | |
919 klass, | |
920 vmSymbolHandles::setProperty_name(), | |
921 vmSymbolHandles::string_string_string_signature(), | |
922 key_str, | |
923 value_str, | |
924 CHECK); | |
925 } | |
926 | |
927 | |
928 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) { | |
929 assert(thread_group.not_null(), "thread group should be specified"); | |
930 assert(threadObj() == NULL, "should only create Java thread object once"); | |
931 | |
932 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK); | |
933 instanceKlassHandle klass (THREAD, k); | |
934 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); | |
935 | |
936 java_lang_Thread::set_thread(thread_oop(), this); | |
937 java_lang_Thread::set_priority(thread_oop(), NormPriority); | |
938 set_threadObj(thread_oop()); | |
939 | |
940 JavaValue result(T_VOID); | |
941 if (thread_name != NULL) { | |
942 Handle name = java_lang_String::create_from_str(thread_name, CHECK); | |
943 // Thread gets assigned specified name and null target | |
944 JavaCalls::call_special(&result, | |
945 thread_oop, | |
946 klass, | |
947 vmSymbolHandles::object_initializer_name(), | |
948 vmSymbolHandles::threadgroup_string_void_signature(), | |
949 thread_group, // Argument 1 | |
950 name, // Argument 2 | |
951 THREAD); | |
952 } else { | |
953 // Thread gets assigned name "Thread-nnn" and null target | |
954 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) | |
955 JavaCalls::call_special(&result, | |
956 thread_oop, | |
957 klass, | |
958 vmSymbolHandles::object_initializer_name(), | |
959 vmSymbolHandles::threadgroup_runnable_void_signature(), | |
960 thread_group, // Argument 1 | |
961 Handle(), // Argument 2 | |
962 THREAD); | |
963 } | |
964 | |
965 | |
966 if (daemon) { | |
967 java_lang_Thread::set_daemon(thread_oop()); | |
968 } | |
969 | |
970 if (HAS_PENDING_EXCEPTION) { | |
971 return; | |
972 } | |
973 | |
974 KlassHandle group(this, SystemDictionary::threadGroup_klass()); | |
975 Handle threadObj(this, this->threadObj()); | |
976 | |
977 JavaCalls::call_special(&result, | |
978 thread_group, | |
979 group, | |
980 vmSymbolHandles::add_method_name(), | |
981 vmSymbolHandles::thread_void_signature(), | |
982 threadObj, // Arg 1 | |
983 THREAD); | |
984 | |
985 | |
986 } | |
987 | |
988 // NamedThread -- non-JavaThread subclasses with multiple | |
989 // uniquely named instances should derive from this. | |
990 NamedThread::NamedThread() : Thread() { | |
991 _name = NULL; | |
992 } | |
993 | |
994 NamedThread::~NamedThread() { | |
995 if (_name != NULL) { | |
996 FREE_C_HEAP_ARRAY(char, _name); | |
997 _name = NULL; | |
998 } | |
999 } | |
1000 | |
1001 void NamedThread::set_name(const char* format, ...) { | |
1002 guarantee(_name == NULL, "Only get to set name once."); | |
1003 _name = NEW_C_HEAP_ARRAY(char, max_name_len); | |
1004 guarantee(_name != NULL, "alloc failure"); | |
1005 va_list ap; | |
1006 va_start(ap, format); | |
1007 jio_vsnprintf(_name, max_name_len, format, ap); | |
1008 va_end(ap); | |
1009 } | |
1010 | |
1011 // ======= WatcherThread ======== | |
1012 | |
1013 // The watcher thread exists to simulate timer interrupts. It should | |
1014 // be replaced by an abstraction over whatever native support for | |
1015 // timer interrupts exists on the platform. | |
1016 | |
1017 WatcherThread* WatcherThread::_watcher_thread = NULL; | |
1018 bool WatcherThread::_should_terminate = false; | |
1019 | |
1020 WatcherThread::WatcherThread() : Thread() { | |
1021 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread"); | |
1022 if (os::create_thread(this, os::watcher_thread)) { | |
1023 _watcher_thread = this; | |
1024 | |
1025 // Set the watcher thread to the highest OS priority which should not be | |
1026 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY | |
1027 // is created. The only normal thread using this priority is the reference | |
1028 // handler thread, which runs for very short intervals only. | |
1029 // If the VMThread's priority is not lower than the WatcherThread profiling | |
1030 // will be inaccurate. | |
1031 os::set_priority(this, MaxPriority); | |
1032 if (!DisableStartThread) { | |
1033 os::start_thread(this); | |
1034 } | |
1035 } | |
1036 } | |
1037 | |
1038 void WatcherThread::run() { | |
1039 assert(this == watcher_thread(), "just checking"); | |
1040 | |
1041 this->record_stack_base_and_size(); | |
1042 this->initialize_thread_local_storage(); | |
1043 this->set_active_handles(JNIHandleBlock::allocate_block()); | |
1044 while(!_should_terminate) { | |
1045 assert(watcher_thread() == Thread::current(), "thread consistency check"); | |
1046 assert(watcher_thread() == this, "thread consistency check"); | |
1047 | |
1048 // Calculate how long it'll be until the next PeriodicTask work | |
1049 // should be done, and sleep that amount of time. | |
1050 const size_t time_to_wait = PeriodicTask::time_to_wait(); | |
1051 os::sleep(this, time_to_wait, false); | |
1052 | |
1053 if (is_error_reported()) { | |
1054 // A fatal error has happened, the error handler(VMError::report_and_die) | |
1055 // should abort JVM after creating an error log file. However in some | |
1056 // rare cases, the error handler itself might deadlock. Here we try to | |
1057 // kill JVM if the fatal error handler fails to abort in 2 minutes. | |
1058 // | |
1059 // This code is in WatcherThread because WatcherThread wakes up | |
1060 // periodically so the fatal error handler doesn't need to do anything; | |
1061 // also because the WatcherThread is less likely to crash than other | |
1062 // threads. | |
1063 | |
1064 for (;;) { | |
1065 if (!ShowMessageBoxOnError | |
1066 && (OnError == NULL || OnError[0] == '\0') | |
1067 && Arguments::abort_hook() == NULL) { | |
1068 os::sleep(this, 2 * 60 * 1000, false); | |
1069 fdStream err(defaultStream::output_fd()); | |
1070 err.print_raw_cr("# [ timer expired, abort... ]"); | |
1071 // skip atexit/vm_exit/vm_abort hooks | |
1072 os::die(); | |
1073 } | |
1074 | |
1075 // Wake up 5 seconds later, the fatal handler may reset OnError or | |
1076 // ShowMessageBoxOnError when it is ready to abort. | |
1077 os::sleep(this, 5 * 1000, false); | |
1078 } | |
1079 } | |
1080 | |
1081 PeriodicTask::real_time_tick(time_to_wait); | |
1082 | |
1083 // If we have no more tasks left due to dynamic disenrollment, | |
1084 // shut down the thread since we don't currently support dynamic enrollment | |
1085 if (PeriodicTask::num_tasks() == 0) { | |
1086 _should_terminate = true; | |
1087 } | |
1088 } | |
1089 | |
1090 // Signal that it is terminated | |
1091 { | |
1092 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag); | |
1093 _watcher_thread = NULL; | |
1094 Terminator_lock->notify(); | |
1095 } | |
1096 | |
1097 // Thread destructor usually does this.. | |
1098 ThreadLocalStorage::set_thread(NULL); | |
1099 } | |
1100 | |
1101 void WatcherThread::start() { | |
1102 if (watcher_thread() == NULL) { | |
1103 _should_terminate = false; | |
1104 // Create the single instance of WatcherThread | |
1105 new WatcherThread(); | |
1106 } | |
1107 } | |
1108 | |
1109 void WatcherThread::stop() { | |
1110 // it is ok to take late safepoints here, if needed | |
1111 MutexLocker mu(Terminator_lock); | |
1112 _should_terminate = true; | |
1113 while(watcher_thread() != NULL) { | |
1114 // This wait should make safepoint checks, wait without a timeout, | |
1115 // and wait as a suspend-equivalent condition. | |
1116 // | |
1117 // Note: If the FlatProfiler is running, then this thread is waiting | |
1118 // for the WatcherThread to terminate and the WatcherThread, via the | |
1119 // FlatProfiler task, is waiting for the external suspend request on | |
1120 // this thread to complete. wait_for_ext_suspend_completion() will | |
1121 // eventually timeout, but that takes time. Making this wait a | |
1122 // suspend-equivalent condition solves that timeout problem. | |
1123 // | |
1124 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0, | |
1125 Mutex::_as_suspend_equivalent_flag); | |
1126 } | |
1127 } | |
1128 | |
1129 void WatcherThread::print_on(outputStream* st) const { | |
1130 st->print("\"%s\" ", name()); | |
1131 Thread::print_on(st); | |
1132 st->cr(); | |
1133 } | |
1134 | |
1135 // ======= JavaThread ======== | |
1136 | |
1137 // A JavaThread is a normal Java thread | |
1138 | |
1139 void JavaThread::initialize() { | |
1140 // Initialize fields | |
1141 set_saved_exception_pc(NULL); | |
1142 set_threadObj(NULL); | |
1143 _anchor.clear(); | |
1144 set_entry_point(NULL); | |
1145 set_jni_functions(jni_functions()); | |
1146 set_callee_target(NULL); | |
1147 set_vm_result(NULL); | |
1148 set_vm_result_2(NULL); | |
1149 set_vframe_array_head(NULL); | |
1150 set_vframe_array_last(NULL); | |
1151 set_deferred_locals(NULL); | |
1152 set_deopt_mark(NULL); | |
1153 clear_must_deopt_id(); | |
1154 set_monitor_chunks(NULL); | |
1155 set_next(NULL); | |
1156 set_thread_state(_thread_new); | |
1157 _terminated = _not_terminated; | |
1158 _privileged_stack_top = NULL; | |
1159 _array_for_gc = NULL; | |
1160 _suspend_equivalent = false; | |
1161 _in_deopt_handler = 0; | |
1162 _doing_unsafe_access = false; | |
1163 _stack_guard_state = stack_guard_unused; | |
1164 _exception_oop = NULL; | |
1165 _exception_pc = 0; | |
1166 _exception_handler_pc = 0; | |
1167 _exception_stack_size = 0; | |
1168 _jvmti_thread_state= NULL; | |
1169 _jvmti_get_loaded_classes_closure = NULL; | |
1170 _interp_only_mode = 0; | |
1171 _special_runtime_exit_condition = _no_async_condition; | |
1172 _pending_async_exception = NULL; | |
1173 _is_compiling = false; | |
1174 _thread_stat = NULL; | |
1175 _thread_stat = new ThreadStatistics(); | |
1176 _blocked_on_compilation = false; | |
1177 _jni_active_critical = 0; | |
1178 _do_not_unlock_if_synchronized = false; | |
1179 _cached_monitor_info = NULL; | |
1180 _parker = Parker::Allocate(this) ; | |
1181 | |
1182 #ifndef PRODUCT | |
1183 _jmp_ring_index = 0; | |
1184 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) { | |
1185 record_jump(NULL, NULL, NULL, 0); | |
1186 } | |
1187 #endif /* PRODUCT */ | |
1188 | |
1189 set_thread_profiler(NULL); | |
1190 if (FlatProfiler::is_active()) { | |
1191 // This is where we would decide to either give each thread it's own profiler | |
1192 // or use one global one from FlatProfiler, | |
1193 // or up to some count of the number of profiled threads, etc. | |
1194 ThreadProfiler* pp = new ThreadProfiler(); | |
1195 pp->engage(); | |
1196 set_thread_profiler(pp); | |
1197 } | |
1198 | |
1199 // Setup safepoint state info for this thread | |
1200 ThreadSafepointState::create(this); | |
1201 | |
1202 debug_only(_java_call_counter = 0); | |
1203 | |
1204 // JVMTI PopFrame support | |
1205 _popframe_condition = popframe_inactive; | |
1206 _popframe_preserved_args = NULL; | |
1207 _popframe_preserved_args_size = 0; | |
1208 | |
1209 pd_initialize(); | |
1210 } | |
1211 | |
1212 JavaThread::JavaThread(bool is_attaching) : Thread() { | |
1213 initialize(); | |
1214 _is_attaching = is_attaching; | |
1215 } | |
1216 | |
1217 bool JavaThread::reguard_stack(address cur_sp) { | |
1218 if (_stack_guard_state != stack_guard_yellow_disabled) { | |
1219 return true; // Stack already guarded or guard pages not needed. | |
1220 } | |
1221 | |
1222 if (register_stack_overflow()) { | |
1223 // For those architectures which have separate register and | |
1224 // memory stacks, we must check the register stack to see if | |
1225 // it has overflowed. | |
1226 return false; | |
1227 } | |
1228 | |
1229 // Java code never executes within the yellow zone: the latter is only | |
1230 // there to provoke an exception during stack banging. If java code | |
1231 // is executing there, either StackShadowPages should be larger, or | |
1232 // some exception code in c1, c2 or the interpreter isn't unwinding | |
1233 // when it should. | |
1234 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages"); | |
1235 | |
1236 enable_stack_yellow_zone(); | |
1237 return true; | |
1238 } | |
1239 | |
1240 bool JavaThread::reguard_stack(void) { | |
1241 return reguard_stack(os::current_stack_pointer()); | |
1242 } | |
1243 | |
1244 | |
1245 void JavaThread::block_if_vm_exited() { | |
1246 if (_terminated == _vm_exited) { | |
1247 // _vm_exited is set at safepoint, and Threads_lock is never released | |
1248 // we will block here forever | |
1249 Threads_lock->lock_without_safepoint_check(); | |
1250 ShouldNotReachHere(); | |
1251 } | |
1252 } | |
1253 | |
1254 | |
1255 // Remove this ifdef when C1 is ported to the compiler interface. | |
1256 static void compiler_thread_entry(JavaThread* thread, TRAPS); | |
1257 | |
1258 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : Thread() { | |
1259 if (TraceThreadEvents) { | |
1260 tty->print_cr("creating thread %p", this); | |
1261 } | |
1262 initialize(); | |
1263 _is_attaching = false; | |
1264 set_entry_point(entry_point); | |
1265 // Create the native thread itself. | |
1266 // %note runtime_23 | |
1267 os::ThreadType thr_type = os::java_thread; | |
1268 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread : | |
1269 os::java_thread; | |
1270 os::create_thread(this, thr_type, stack_sz); | |
1271 | |
1272 // The _osthread may be NULL here because we ran out of memory (too many threads active). | |
1273 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller | |
1274 // may hold a lock and all locks must be unlocked before throwing the exception (throwing | |
1275 // the exception consists of creating the exception object & initializing it, initialization | |
1276 // will leave the VM via a JavaCall and then all locks must be unlocked). | |
1277 // | |
1278 // The thread is still suspended when we reach here. Thread must be explicit started | |
1279 // by creator! Furthermore, the thread must also explicitly be added to the Threads list | |
1280 // by calling Threads:add. The reason why this is not done here, is because the thread | |
1281 // object must be fully initialized (take a look at JVM_Start) | |
1282 } | |
1283 | |
1284 JavaThread::~JavaThread() { | |
1285 if (TraceThreadEvents) { | |
1286 tty->print_cr("terminate thread %p", this); | |
1287 } | |
1288 | |
1289 // JSR166 -- return the parker to the free list | |
1290 Parker::Release(_parker); | |
1291 _parker = NULL ; | |
1292 | |
1293 // Free any remaining previous UnrollBlock | |
1294 vframeArray* old_array = vframe_array_last(); | |
1295 | |
1296 if (old_array != NULL) { | |
1297 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); | |
1298 old_array->set_unroll_block(NULL); | |
1299 delete old_info; | |
1300 delete old_array; | |
1301 } | |
1302 | |
1303 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals(); | |
1304 if (deferred != NULL) { | |
1305 // This can only happen if thread is destroyed before deoptimization occurs. | |
1306 assert(deferred->length() != 0, "empty array!"); | |
1307 do { | |
1308 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0); | |
1309 deferred->remove_at(0); | |
1310 // individual jvmtiDeferredLocalVariableSet are CHeapObj's | |
1311 delete dlv; | |
1312 } while (deferred->length() != 0); | |
1313 delete deferred; | |
1314 } | |
1315 | |
1316 // All Java related clean up happens in exit | |
1317 ThreadSafepointState::destroy(this); | |
1318 if (_thread_profiler != NULL) delete _thread_profiler; | |
1319 if (_thread_stat != NULL) delete _thread_stat; | |
1320 } | |
1321 | |
1322 | |
1323 // The first routine called by a new Java thread | |
1324 void JavaThread::run() { | |
1325 // initialize thread-local alloc buffer related fields | |
1326 this->initialize_tlab(); | |
1327 | |
1328 // used to test validitity of stack trace backs | |
1329 this->record_base_of_stack_pointer(); | |
1330 | |
1331 // Record real stack base and size. | |
1332 this->record_stack_base_and_size(); | |
1333 | |
1334 // Initialize thread local storage; set before calling MutexLocker | |
1335 this->initialize_thread_local_storage(); | |
1336 | |
1337 this->create_stack_guard_pages(); | |
1338 | |
1339 // Thread is now sufficient initialized to be handled by the safepoint code as being | |
1340 // in the VM. Change thread state from _thread_new to _thread_in_vm | |
1341 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm); | |
1342 | |
1343 assert(JavaThread::current() == this, "sanity check"); | |
1344 assert(!Thread::current()->owns_locks(), "sanity check"); | |
1345 | |
1346 DTRACE_THREAD_PROBE(start, this); | |
1347 | |
1348 // This operation might block. We call that after all safepoint checks for a new thread has | |
1349 // been completed. | |
1350 this->set_active_handles(JNIHandleBlock::allocate_block()); | |
1351 | |
1352 if (JvmtiExport::should_post_thread_life()) { | |
1353 JvmtiExport::post_thread_start(this); | |
1354 } | |
1355 | |
1356 // We call another function to do the rest so we are sure that the stack addresses used | |
1357 // from there will be lower than the stack base just computed | |
1358 thread_main_inner(); | |
1359 | |
1360 // Note, thread is no longer valid at this point! | |
1361 } | |
1362 | |
1363 | |
1364 void JavaThread::thread_main_inner() { | |
1365 assert(JavaThread::current() == this, "sanity check"); | |
1366 assert(this->threadObj() != NULL, "just checking"); | |
1367 | |
1368 // Execute thread entry point. If this thread is being asked to restart, | |
1369 // or has been stopped before starting, do not reexecute entry point. | |
1370 // Note: Due to JVM_StopThread we can have pending exceptions already! | |
1371 if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) { | |
1372 // enter the thread's entry point only if we have no pending exceptions | |
1373 HandleMark hm(this); | |
1374 this->entry_point()(this, this); | |
1375 } | |
1376 | |
1377 DTRACE_THREAD_PROBE(stop, this); | |
1378 | |
1379 this->exit(false); | |
1380 delete this; | |
1381 } | |
1382 | |
1383 | |
1384 static void ensure_join(JavaThread* thread) { | |
1385 // We do not need to grap the Threads_lock, since we are operating on ourself. | |
1386 Handle threadObj(thread, thread->threadObj()); | |
1387 assert(threadObj.not_null(), "java thread object must exist"); | |
1388 ObjectLocker lock(threadObj, thread); | |
1389 // Ignore pending exception (ThreadDeath), since we are exiting anyway | |
1390 thread->clear_pending_exception(); | |
1391 // It is of profound importance that we set the stillborn bit and reset the thread object, | |
1392 // before we do the notify. Since, changing these two variable will make JVM_IsAlive return | |
1393 // false. So in case another thread is doing a join on this thread , it will detect that the thread | |
1394 // is dead when it gets notified. | |
1395 java_lang_Thread::set_stillborn(threadObj()); | |
1396 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. | |
1397 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED); | |
1398 java_lang_Thread::set_thread(threadObj(), NULL); | |
1399 lock.notify_all(thread); | |
1400 // Ignore pending exception (ThreadDeath), since we are exiting anyway | |
1401 thread->clear_pending_exception(); | |
1402 } | |
1403 | |
1404 // For any new cleanup additions, please check to see if they need to be applied to | |
1405 // cleanup_failed_attach_current_thread as well. | |
1406 void JavaThread::exit(bool destroy_vm, ExitType exit_type) { | |
1407 assert(this == JavaThread::current(), "thread consistency check"); | |
1408 if (!InitializeJavaLangSystem) return; | |
1409 | |
1410 HandleMark hm(this); | |
1411 Handle uncaught_exception(this, this->pending_exception()); | |
1412 this->clear_pending_exception(); | |
1413 Handle threadObj(this, this->threadObj()); | |
1414 assert(threadObj.not_null(), "Java thread object should be created"); | |
1415 | |
1416 if (get_thread_profiler() != NULL) { | |
1417 get_thread_profiler()->disengage(); | |
1418 ResourceMark rm; | |
1419 get_thread_profiler()->print(get_thread_name()); | |
1420 } | |
1421 | |
1422 | |
1423 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place | |
1424 { | |
1425 EXCEPTION_MARK; | |
1426 | |
1427 CLEAR_PENDING_EXCEPTION; | |
1428 } | |
1429 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This | |
1430 // has to be fixed by a runtime query method | |
1431 if (!destroy_vm || JDK_Version::is_jdk12x_version()) { | |
1432 // JSR-166: change call from from ThreadGroup.uncaughtException to | |
1433 // java.lang.Thread.dispatchUncaughtException | |
1434 if (uncaught_exception.not_null()) { | |
1435 Handle group(this, java_lang_Thread::threadGroup(threadObj())); | |
1436 Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT", | |
1437 (address)uncaught_exception(), (address)threadObj(), (address)group()); | |
1438 { | |
1439 EXCEPTION_MARK; | |
1440 // Check if the method Thread.dispatchUncaughtException() exists. If so | |
1441 // call it. Otherwise we have an older library without the JSR-166 changes, | |
1442 // so call ThreadGroup.uncaughtException() | |
1443 KlassHandle recvrKlass(THREAD, threadObj->klass()); | |
1444 CallInfo callinfo; | |
1445 KlassHandle thread_klass(THREAD, SystemDictionary::thread_klass()); | |
1446 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass, | |
1447 vmSymbolHandles::dispatchUncaughtException_name(), | |
1448 vmSymbolHandles::throwable_void_signature(), | |
1449 KlassHandle(), false, false, THREAD); | |
1450 CLEAR_PENDING_EXCEPTION; | |
1451 methodHandle method = callinfo.selected_method(); | |
1452 if (method.not_null()) { | |
1453 JavaValue result(T_VOID); | |
1454 JavaCalls::call_virtual(&result, | |
1455 threadObj, thread_klass, | |
1456 vmSymbolHandles::dispatchUncaughtException_name(), | |
1457 vmSymbolHandles::throwable_void_signature(), | |
1458 uncaught_exception, | |
1459 THREAD); | |
1460 } else { | |
1461 KlassHandle thread_group(THREAD, SystemDictionary::threadGroup_klass()); | |
1462 JavaValue result(T_VOID); | |
1463 JavaCalls::call_virtual(&result, | |
1464 group, thread_group, | |
1465 vmSymbolHandles::uncaughtException_name(), | |
1466 vmSymbolHandles::thread_throwable_void_signature(), | |
1467 threadObj, // Arg 1 | |
1468 uncaught_exception, // Arg 2 | |
1469 THREAD); | |
1470 } | |
1471 CLEAR_PENDING_EXCEPTION; | |
1472 } | |
1473 } | |
1474 | |
1475 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during | |
1476 // the execution of the method. If that is not enough, then we don't really care. Thread.stop | |
1477 // is deprecated anyhow. | |
1478 { int count = 3; | |
1479 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) { | |
1480 EXCEPTION_MARK; | |
1481 JavaValue result(T_VOID); | |
1482 KlassHandle thread_klass(THREAD, SystemDictionary::thread_klass()); | |
1483 JavaCalls::call_virtual(&result, | |
1484 threadObj, thread_klass, | |
1485 vmSymbolHandles::exit_method_name(), | |
1486 vmSymbolHandles::void_method_signature(), | |
1487 THREAD); | |
1488 CLEAR_PENDING_EXCEPTION; | |
1489 } | |
1490 } | |
1491 | |
1492 // notify JVMTI | |
1493 if (JvmtiExport::should_post_thread_life()) { | |
1494 JvmtiExport::post_thread_end(this); | |
1495 } | |
1496 | |
1497 // We have notified the agents that we are exiting, before we go on, | |
1498 // we must check for a pending external suspend request and honor it | |
1499 // in order to not surprise the thread that made the suspend request. | |
1500 while (true) { | |
1501 { | |
1502 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); | |
1503 if (!is_external_suspend()) { | |
1504 set_terminated(_thread_exiting); | |
1505 ThreadService::current_thread_exiting(this); | |
1506 break; | |
1507 } | |
1508 // Implied else: | |
1509 // Things get a little tricky here. We have a pending external | |
1510 // suspend request, but we are holding the SR_lock so we | |
1511 // can't just self-suspend. So we temporarily drop the lock | |
1512 // and then self-suspend. | |
1513 } | |
1514 | |
1515 ThreadBlockInVM tbivm(this); | |
1516 java_suspend_self(); | |
1517 | |
1518 // We're done with this suspend request, but we have to loop around | |
1519 // and check again. Eventually we will get SR_lock without a pending | |
1520 // external suspend request and will be able to mark ourselves as | |
1521 // exiting. | |
1522 } | |
1523 // no more external suspends are allowed at this point | |
1524 } else { | |
1525 // before_exit() has already posted JVMTI THREAD_END events | |
1526 } | |
1527 | |
1528 // Notify waiters on thread object. This has to be done after exit() is called | |
1529 // on the thread (if the thread is the last thread in a daemon ThreadGroup the | |
1530 // group should have the destroyed bit set before waiters are notified). | |
1531 ensure_join(this); | |
1532 assert(!this->has_pending_exception(), "ensure_join should have cleared"); | |
1533 | |
1534 // 6282335 JNI DetachCurrentThread spec states that all Java monitors | |
1535 // held by this thread must be released. A detach operation must only | |
1536 // get here if there are no Java frames on the stack. Therefore, any | |
1537 // owned monitors at this point MUST be JNI-acquired monitors which are | |
1538 // pre-inflated and in the monitor cache. | |
1539 // | |
1540 // ensure_join() ignores IllegalThreadStateExceptions, and so does this. | |
1541 if (exit_type == jni_detach && JNIDetachReleasesMonitors) { | |
1542 assert(!this->has_last_Java_frame(), "detaching with Java frames?"); | |
1543 ObjectSynchronizer::release_monitors_owned_by_thread(this); | |
1544 assert(!this->has_pending_exception(), "release_monitors should have cleared"); | |
1545 } | |
1546 | |
1547 // These things needs to be done while we are still a Java Thread. Make sure that thread | |
1548 // is in a consistent state, in case GC happens | |
1549 assert(_privileged_stack_top == NULL, "must be NULL when we get here"); | |
1550 | |
1551 if (active_handles() != NULL) { | |
1552 JNIHandleBlock* block = active_handles(); | |
1553 set_active_handles(NULL); | |
1554 JNIHandleBlock::release_block(block); | |
1555 } | |
1556 | |
1557 if (free_handle_block() != NULL) { | |
1558 JNIHandleBlock* block = free_handle_block(); | |
1559 set_free_handle_block(NULL); | |
1560 JNIHandleBlock::release_block(block); | |
1561 } | |
1562 | |
1563 // These have to be removed while this is still a valid thread. | |
1564 remove_stack_guard_pages(); | |
1565 | |
1566 if (UseTLAB) { | |
1567 tlab().make_parsable(true); // retire TLAB | |
1568 } | |
1569 | |
49
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1570 if (jvmti_thread_state() != NULL) { |
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1571 JvmtiExport::cleanup_thread(this); |
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1572 } |
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1573 |
0 | 1574 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread |
1575 Threads::remove(this); | |
1576 } | |
1577 | |
1578 void JavaThread::cleanup_failed_attach_current_thread() { | |
1579 | |
1580 if (get_thread_profiler() != NULL) { | |
1581 get_thread_profiler()->disengage(); | |
1582 ResourceMark rm; | |
1583 get_thread_profiler()->print(get_thread_name()); | |
1584 } | |
1585 | |
1586 if (active_handles() != NULL) { | |
1587 JNIHandleBlock* block = active_handles(); | |
1588 set_active_handles(NULL); | |
1589 JNIHandleBlock::release_block(block); | |
1590 } | |
1591 | |
1592 if (free_handle_block() != NULL) { | |
1593 JNIHandleBlock* block = free_handle_block(); | |
1594 set_free_handle_block(NULL); | |
1595 JNIHandleBlock::release_block(block); | |
1596 } | |
1597 | |
1598 if (UseTLAB) { | |
1599 tlab().make_parsable(true); // retire TLAB, if any | |
1600 } | |
1601 | |
1602 Threads::remove(this); | |
1603 delete this; | |
1604 } | |
1605 | |
1606 | |
1607 JavaThread* JavaThread::active() { | |
1608 Thread* thread = ThreadLocalStorage::thread(); | |
1609 assert(thread != NULL, "just checking"); | |
1610 if (thread->is_Java_thread()) { | |
1611 return (JavaThread*) thread; | |
1612 } else { | |
1613 assert(thread->is_VM_thread(), "this must be a vm thread"); | |
1614 VM_Operation* op = ((VMThread*) thread)->vm_operation(); | |
1615 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread(); | |
1616 assert(ret->is_Java_thread(), "must be a Java thread"); | |
1617 return ret; | |
1618 } | |
1619 } | |
1620 | |
1621 bool JavaThread::is_lock_owned(address adr) const { | |
1622 if (lock_is_in_stack(adr)) return true; | |
1623 | |
1624 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { | |
1625 if (chunk->contains(adr)) return true; | |
1626 } | |
1627 | |
1628 return false; | |
1629 } | |
1630 | |
1631 | |
1632 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) { | |
1633 chunk->set_next(monitor_chunks()); | |
1634 set_monitor_chunks(chunk); | |
1635 } | |
1636 | |
1637 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) { | |
1638 guarantee(monitor_chunks() != NULL, "must be non empty"); | |
1639 if (monitor_chunks() == chunk) { | |
1640 set_monitor_chunks(chunk->next()); | |
1641 } else { | |
1642 MonitorChunk* prev = monitor_chunks(); | |
1643 while (prev->next() != chunk) prev = prev->next(); | |
1644 prev->set_next(chunk->next()); | |
1645 } | |
1646 } | |
1647 | |
1648 // JVM support. | |
1649 | |
1650 // Note: this function shouldn't block if it's called in | |
1651 // _thread_in_native_trans state (such as from | |
1652 // check_special_condition_for_native_trans()). | |
1653 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) { | |
1654 | |
1655 if (has_last_Java_frame() && has_async_condition()) { | |
1656 // If we are at a polling page safepoint (not a poll return) | |
1657 // then we must defer async exception because live registers | |
1658 // will be clobbered by the exception path. Poll return is | |
1659 // ok because the call we a returning from already collides | |
1660 // with exception handling registers and so there is no issue. | |
1661 // (The exception handling path kills call result registers but | |
1662 // this is ok since the exception kills the result anyway). | |
1663 | |
1664 if (is_at_poll_safepoint()) { | |
1665 // if the code we are returning to has deoptimized we must defer | |
1666 // the exception otherwise live registers get clobbered on the | |
1667 // exception path before deoptimization is able to retrieve them. | |
1668 // | |
1669 RegisterMap map(this, false); | |
1670 frame caller_fr = last_frame().sender(&map); | |
1671 assert(caller_fr.is_compiled_frame(), "what?"); | |
1672 if (caller_fr.is_deoptimized_frame()) { | |
1673 if (TraceExceptions) { | |
1674 ResourceMark rm; | |
1675 tty->print_cr("deferred async exception at compiled safepoint"); | |
1676 } | |
1677 return; | |
1678 } | |
1679 } | |
1680 } | |
1681 | |
1682 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition(); | |
1683 if (condition == _no_async_condition) { | |
1684 // Conditions have changed since has_special_runtime_exit_condition() | |
1685 // was called: | |
1686 // - if we were here only because of an external suspend request, | |
1687 // then that was taken care of above (or cancelled) so we are done | |
1688 // - if we were here because of another async request, then it has | |
1689 // been cleared between the has_special_runtime_exit_condition() | |
1690 // and now so again we are done | |
1691 return; | |
1692 } | |
1693 | |
1694 // Check for pending async. exception | |
1695 if (_pending_async_exception != NULL) { | |
1696 // Only overwrite an already pending exception, if it is not a threadDeath. | |
1697 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::threaddeath_klass())) { | |
1698 | |
1699 // We cannot call Exceptions::_throw(...) here because we cannot block | |
1700 set_pending_exception(_pending_async_exception, __FILE__, __LINE__); | |
1701 | |
1702 if (TraceExceptions) { | |
1703 ResourceMark rm; | |
1704 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this); | |
1705 if (has_last_Java_frame() ) { | |
1706 frame f = last_frame(); | |
1707 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp()); | |
1708 } | |
1709 tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name()); | |
1710 } | |
1711 _pending_async_exception = NULL; | |
1712 clear_has_async_exception(); | |
1713 } | |
1714 } | |
1715 | |
1716 if (check_unsafe_error && | |
1717 condition == _async_unsafe_access_error && !has_pending_exception()) { | |
1718 condition = _no_async_condition; // done | |
1719 switch (thread_state()) { | |
1720 case _thread_in_vm: | |
1721 { | |
1722 JavaThread* THREAD = this; | |
1723 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); | |
1724 } | |
1725 case _thread_in_native: | |
1726 { | |
1727 ThreadInVMfromNative tiv(this); | |
1728 JavaThread* THREAD = this; | |
1729 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); | |
1730 } | |
1731 case _thread_in_Java: | |
1732 { | |
1733 ThreadInVMfromJava tiv(this); | |
1734 JavaThread* THREAD = this; | |
1735 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code"); | |
1736 } | |
1737 default: | |
1738 ShouldNotReachHere(); | |
1739 } | |
1740 } | |
1741 | |
1742 assert(condition == _no_async_condition || has_pending_exception() || | |
1743 (!check_unsafe_error && condition == _async_unsafe_access_error), | |
1744 "must have handled the async condition, if no exception"); | |
1745 } | |
1746 | |
1747 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) { | |
1748 // | |
1749 // Check for pending external suspend. Internal suspend requests do | |
1750 // not use handle_special_runtime_exit_condition(). | |
1751 // If JNIEnv proxies are allowed, don't self-suspend if the target | |
1752 // thread is not the current thread. In older versions of jdbx, jdbx | |
1753 // threads could call into the VM with another thread's JNIEnv so we | |
1754 // can be here operating on behalf of a suspended thread (4432884). | |
1755 bool do_self_suspend = is_external_suspend_with_lock(); | |
1756 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) { | |
1757 // | |
1758 // Because thread is external suspended the safepoint code will count | |
1759 // thread as at a safepoint. This can be odd because we can be here | |
1760 // as _thread_in_Java which would normally transition to _thread_blocked | |
1761 // at a safepoint. We would like to mark the thread as _thread_blocked | |
1762 // before calling java_suspend_self like all other callers of it but | |
1763 // we must then observe proper safepoint protocol. (We can't leave | |
1764 // _thread_blocked with a safepoint in progress). However we can be | |
1765 // here as _thread_in_native_trans so we can't use a normal transition | |
1766 // constructor/destructor pair because they assert on that type of | |
1767 // transition. We could do something like: | |
1768 // | |
1769 // JavaThreadState state = thread_state(); | |
1770 // set_thread_state(_thread_in_vm); | |
1771 // { | |
1772 // ThreadBlockInVM tbivm(this); | |
1773 // java_suspend_self() | |
1774 // } | |
1775 // set_thread_state(_thread_in_vm_trans); | |
1776 // if (safepoint) block; | |
1777 // set_thread_state(state); | |
1778 // | |
1779 // but that is pretty messy. Instead we just go with the way the | |
1780 // code has worked before and note that this is the only path to | |
1781 // java_suspend_self that doesn't put the thread in _thread_blocked | |
1782 // mode. | |
1783 | |
1784 frame_anchor()->make_walkable(this); | |
1785 java_suspend_self(); | |
1786 | |
1787 // We might be here for reasons in addition to the self-suspend request | |
1788 // so check for other async requests. | |
1789 } | |
1790 | |
1791 if (check_asyncs) { | |
1792 check_and_handle_async_exceptions(); | |
1793 } | |
1794 } | |
1795 | |
1796 void JavaThread::send_thread_stop(oop java_throwable) { | |
1797 assert(Thread::current()->is_VM_thread(), "should be in the vm thread"); | |
1798 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code"); | |
1799 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); | |
1800 | |
1801 // Do not throw asynchronous exceptions against the compiler thread | |
1802 // (the compiler thread should not be a Java thread -- fix in 1.4.2) | |
1803 if (is_Compiler_thread()) return; | |
1804 | |
1805 // This is a change from JDK 1.1, but JDK 1.2 will also do it: | |
1806 if (java_throwable->is_a(SystemDictionary::threaddeath_klass())) { | |
1807 java_lang_Thread::set_stillborn(threadObj()); | |
1808 } | |
1809 | |
1810 { | |
1811 // Actually throw the Throwable against the target Thread - however | |
1812 // only if there is no thread death exception installed already. | |
1813 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::threaddeath_klass())) { | |
1814 // If the topmost frame is a runtime stub, then we are calling into | |
1815 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) | |
1816 // must deoptimize the caller before continuing, as the compiled exception handler table | |
1817 // may not be valid | |
1818 if (has_last_Java_frame()) { | |
1819 frame f = last_frame(); | |
1820 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) { | |
1821 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass | |
1822 RegisterMap reg_map(this, UseBiasedLocking); | |
1823 frame compiled_frame = f.sender(®_map); | |
1824 if (compiled_frame.can_be_deoptimized()) { | |
1825 Deoptimization::deoptimize(this, compiled_frame, ®_map); | |
1826 } | |
1827 } | |
1828 } | |
1829 | |
1830 // Set async. pending exception in thread. | |
1831 set_pending_async_exception(java_throwable); | |
1832 | |
1833 if (TraceExceptions) { | |
1834 ResourceMark rm; | |
1835 tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name()); | |
1836 } | |
1837 // for AbortVMOnException flag | |
1838 NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name())); | |
1839 } | |
1840 } | |
1841 | |
1842 | |
1843 // Interrupt thread so it will wake up from a potential wait() | |
1844 Thread::interrupt(this); | |
1845 } | |
1846 | |
1847 // External suspension mechanism. | |
1848 // | |
1849 // Tell the VM to suspend a thread when ever it knows that it does not hold on | |
1850 // to any VM_locks and it is at a transition | |
1851 // Self-suspension will happen on the transition out of the vm. | |
1852 // Catch "this" coming in from JNIEnv pointers when the thread has been freed | |
1853 // | |
1854 // Guarantees on return: | |
1855 // + Target thread will not execute any new bytecode (that's why we need to | |
1856 // force a safepoint) | |
1857 // + Target thread will not enter any new monitors | |
1858 // | |
1859 void JavaThread::java_suspend() { | |
1860 { MutexLocker mu(Threads_lock); | |
1861 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) { | |
1862 return; | |
1863 } | |
1864 } | |
1865 | |
1866 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); | |
1867 if (!is_external_suspend()) { | |
1868 // a racing resume has cancelled us; bail out now | |
1869 return; | |
1870 } | |
1871 | |
1872 // suspend is done | |
1873 uint32_t debug_bits = 0; | |
1874 // Warning: is_ext_suspend_completed() may temporarily drop the | |
1875 // SR_lock to allow the thread to reach a stable thread state if | |
1876 // it is currently in a transient thread state. | |
1877 if (is_ext_suspend_completed(false /* !called_by_wait */, | |
1878 SuspendRetryDelay, &debug_bits) ) { | |
1879 return; | |
1880 } | |
1881 } | |
1882 | |
1883 VM_ForceSafepoint vm_suspend; | |
1884 VMThread::execute(&vm_suspend); | |
1885 } | |
1886 | |
1887 // Part II of external suspension. | |
1888 // A JavaThread self suspends when it detects a pending external suspend | |
1889 // request. This is usually on transitions. It is also done in places | |
1890 // where continuing to the next transition would surprise the caller, | |
1891 // e.g., monitor entry. | |
1892 // | |
1893 // Returns the number of times that the thread self-suspended. | |
1894 // | |
1895 // Note: DO NOT call java_suspend_self() when you just want to block current | |
1896 // thread. java_suspend_self() is the second stage of cooperative | |
1897 // suspension for external suspend requests and should only be used | |
1898 // to complete an external suspend request. | |
1899 // | |
1900 int JavaThread::java_suspend_self() { | |
1901 int ret = 0; | |
1902 | |
1903 // we are in the process of exiting so don't suspend | |
1904 if (is_exiting()) { | |
1905 clear_external_suspend(); | |
1906 return ret; | |
1907 } | |
1908 | |
1909 assert(_anchor.walkable() || | |
1910 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()), | |
1911 "must have walkable stack"); | |
1912 | |
1913 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); | |
1914 | |
1915 assert(!this->is_any_suspended(), | |
1916 "a thread trying to self-suspend should not already be suspended"); | |
1917 | |
1918 if (this->is_suspend_equivalent()) { | |
1919 // If we are self-suspending as a result of the lifting of a | |
1920 // suspend equivalent condition, then the suspend_equivalent | |
1921 // flag is not cleared until we set the ext_suspended flag so | |
1922 // that wait_for_ext_suspend_completion() returns consistent | |
1923 // results. | |
1924 this->clear_suspend_equivalent(); | |
1925 } | |
1926 | |
1927 // A racing resume may have cancelled us before we grabbed SR_lock | |
1928 // above. Or another external suspend request could be waiting for us | |
1929 // by the time we return from SR_lock()->wait(). The thread | |
1930 // that requested the suspension may already be trying to walk our | |
1931 // stack and if we return now, we can change the stack out from under | |
1932 // it. This would be a "bad thing (TM)" and cause the stack walker | |
1933 // to crash. We stay self-suspended until there are no more pending | |
1934 // external suspend requests. | |
1935 while (is_external_suspend()) { | |
1936 ret++; | |
1937 this->set_ext_suspended(); | |
1938 | |
1939 // _ext_suspended flag is cleared by java_resume() | |
1940 while (is_ext_suspended()) { | |
1941 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag); | |
1942 } | |
1943 } | |
1944 | |
1945 return ret; | |
1946 } | |
1947 | |
1948 #ifdef ASSERT | |
1949 // verify the JavaThread has not yet been published in the Threads::list, and | |
1950 // hence doesn't need protection from concurrent access at this stage | |
1951 void JavaThread::verify_not_published() { | |
1952 if (!Threads_lock->owned_by_self()) { | |
1953 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag); | |
1954 assert( !Threads::includes(this), | |
1955 "java thread shouldn't have been published yet!"); | |
1956 } | |
1957 else { | |
1958 assert( !Threads::includes(this), | |
1959 "java thread shouldn't have been published yet!"); | |
1960 } | |
1961 } | |
1962 #endif | |
1963 | |
1964 // Slow path when the native==>VM/Java barriers detect a safepoint is in | |
1965 // progress or when _suspend_flags is non-zero. | |
1966 // Current thread needs to self-suspend if there is a suspend request and/or | |
1967 // block if a safepoint is in progress. | |
1968 // Async exception ISN'T checked. | |
1969 // Note only the ThreadInVMfromNative transition can call this function | |
1970 // directly and when thread state is _thread_in_native_trans | |
1971 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) { | |
1972 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); | |
1973 | |
1974 JavaThread *curJT = JavaThread::current(); | |
1975 bool do_self_suspend = thread->is_external_suspend(); | |
1976 | |
1977 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition"); | |
1978 | |
1979 // If JNIEnv proxies are allowed, don't self-suspend if the target | |
1980 // thread is not the current thread. In older versions of jdbx, jdbx | |
1981 // threads could call into the VM with another thread's JNIEnv so we | |
1982 // can be here operating on behalf of a suspended thread (4432884). | |
1983 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) { | |
1984 JavaThreadState state = thread->thread_state(); | |
1985 | |
1986 // We mark this thread_blocked state as a suspend-equivalent so | |
1987 // that a caller to is_ext_suspend_completed() won't be confused. | |
1988 // The suspend-equivalent state is cleared by java_suspend_self(). | |
1989 thread->set_suspend_equivalent(); | |
1990 | |
1991 // If the safepoint code sees the _thread_in_native_trans state, it will | |
1992 // wait until the thread changes to other thread state. There is no | |
1993 // guarantee on how soon we can obtain the SR_lock and complete the | |
1994 // self-suspend request. It would be a bad idea to let safepoint wait for | |
1995 // too long. Temporarily change the state to _thread_blocked to | |
1996 // let the VM thread know that this thread is ready for GC. The problem | |
1997 // of changing thread state is that safepoint could happen just after | |
1998 // java_suspend_self() returns after being resumed, and VM thread will | |
1999 // see the _thread_blocked state. We must check for safepoint | |
2000 // after restoring the state and make sure we won't leave while a safepoint | |
2001 // is in progress. | |
2002 thread->set_thread_state(_thread_blocked); | |
2003 thread->java_suspend_self(); | |
2004 thread->set_thread_state(state); | |
2005 // Make sure new state is seen by VM thread | |
2006 if (os::is_MP()) { | |
2007 if (UseMembar) { | |
2008 // Force a fence between the write above and read below | |
2009 OrderAccess::fence(); | |
2010 } else { | |
2011 // Must use this rather than serialization page in particular on Windows | |
2012 InterfaceSupport::serialize_memory(thread); | |
2013 } | |
2014 } | |
2015 } | |
2016 | |
2017 if (SafepointSynchronize::do_call_back()) { | |
2018 // If we are safepointing, then block the caller which may not be | |
2019 // the same as the target thread (see above). | |
2020 SafepointSynchronize::block(curJT); | |
2021 } | |
2022 | |
2023 if (thread->is_deopt_suspend()) { | |
2024 thread->clear_deopt_suspend(); | |
2025 RegisterMap map(thread, false); | |
2026 frame f = thread->last_frame(); | |
2027 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) { | |
2028 f = f.sender(&map); | |
2029 } | |
2030 if (f.id() == thread->must_deopt_id()) { | |
2031 thread->clear_must_deopt_id(); | |
2032 // Since we know we're safe to deopt the current state is a safe state | |
2033 f.deoptimize(thread, true); | |
2034 } else { | |
2035 fatal("missed deoptimization!"); | |
2036 } | |
2037 } | |
2038 } | |
2039 | |
2040 // Slow path when the native==>VM/Java barriers detect a safepoint is in | |
2041 // progress or when _suspend_flags is non-zero. | |
2042 // Current thread needs to self-suspend if there is a suspend request and/or | |
2043 // block if a safepoint is in progress. | |
2044 // Also check for pending async exception (not including unsafe access error). | |
2045 // Note only the native==>VM/Java barriers can call this function and when | |
2046 // thread state is _thread_in_native_trans. | |
2047 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { | |
2048 check_safepoint_and_suspend_for_native_trans(thread); | |
2049 | |
2050 if (thread->has_async_exception()) { | |
2051 // We are in _thread_in_native_trans state, don't handle unsafe | |
2052 // access error since that may block. | |
2053 thread->check_and_handle_async_exceptions(false); | |
2054 } | |
2055 } | |
2056 | |
2057 // We need to guarantee the Threads_lock here, since resumes are not | |
2058 // allowed during safepoint synchronization | |
2059 // Can only resume from an external suspension | |
2060 void JavaThread::java_resume() { | |
2061 assert_locked_or_safepoint(Threads_lock); | |
2062 | |
2063 // Sanity check: thread is gone, has started exiting or the thread | |
2064 // was not externally suspended. | |
2065 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) { | |
2066 return; | |
2067 } | |
2068 | |
2069 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); | |
2070 | |
2071 clear_external_suspend(); | |
2072 | |
2073 if (is_ext_suspended()) { | |
2074 clear_ext_suspended(); | |
2075 SR_lock()->notify_all(); | |
2076 } | |
2077 } | |
2078 | |
2079 void JavaThread::create_stack_guard_pages() { | |
2080 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return; | |
2081 address low_addr = stack_base() - stack_size(); | |
2082 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); | |
2083 | |
2084 int allocate = os::allocate_stack_guard_pages(); | |
2085 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len); | |
2086 | |
2087 if (allocate && !os::commit_memory((char *) low_addr, len)) { | |
2088 warning("Attempt to allocate stack guard pages failed."); | |
2089 return; | |
2090 } | |
2091 | |
2092 if (os::guard_memory((char *) low_addr, len)) { | |
2093 _stack_guard_state = stack_guard_enabled; | |
2094 } else { | |
2095 warning("Attempt to protect stack guard pages failed."); | |
2096 if (os::uncommit_memory((char *) low_addr, len)) { | |
2097 warning("Attempt to deallocate stack guard pages failed."); | |
2098 } | |
2099 } | |
2100 } | |
2101 | |
2102 void JavaThread::remove_stack_guard_pages() { | |
2103 if (_stack_guard_state == stack_guard_unused) return; | |
2104 address low_addr = stack_base() - stack_size(); | |
2105 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); | |
2106 | |
2107 if (os::allocate_stack_guard_pages()) { | |
2108 if (os::uncommit_memory((char *) low_addr, len)) { | |
2109 _stack_guard_state = stack_guard_unused; | |
2110 } else { | |
2111 warning("Attempt to deallocate stack guard pages failed."); | |
2112 } | |
2113 } else { | |
2114 if (_stack_guard_state == stack_guard_unused) return; | |
2115 if (os::unguard_memory((char *) low_addr, len)) { | |
2116 _stack_guard_state = stack_guard_unused; | |
2117 } else { | |
2118 warning("Attempt to unprotect stack guard pages failed."); | |
2119 } | |
2120 } | |
2121 } | |
2122 | |
2123 void JavaThread::enable_stack_yellow_zone() { | |
2124 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); | |
2125 assert(_stack_guard_state != stack_guard_enabled, "already enabled"); | |
2126 | |
2127 // The base notation is from the stacks point of view, growing downward. | |
2128 // We need to adjust it to work correctly with guard_memory() | |
2129 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); | |
2130 | |
2131 guarantee(base < stack_base(),"Error calculating stack yellow zone"); | |
2132 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone"); | |
2133 | |
2134 if (os::guard_memory((char *) base, stack_yellow_zone_size())) { | |
2135 _stack_guard_state = stack_guard_enabled; | |
2136 } else { | |
2137 warning("Attempt to guard stack yellow zone failed."); | |
2138 } | |
2139 enable_register_stack_guard(); | |
2140 } | |
2141 | |
2142 void JavaThread::disable_stack_yellow_zone() { | |
2143 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); | |
2144 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled"); | |
2145 | |
2146 // Simply return if called for a thread that does not use guard pages. | |
2147 if (_stack_guard_state == stack_guard_unused) return; | |
2148 | |
2149 // The base notation is from the stacks point of view, growing downward. | |
2150 // We need to adjust it to work correctly with guard_memory() | |
2151 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); | |
2152 | |
2153 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) { | |
2154 _stack_guard_state = stack_guard_yellow_disabled; | |
2155 } else { | |
2156 warning("Attempt to unguard stack yellow zone failed."); | |
2157 } | |
2158 disable_register_stack_guard(); | |
2159 } | |
2160 | |
2161 void JavaThread::enable_stack_red_zone() { | |
2162 // The base notation is from the stacks point of view, growing downward. | |
2163 // We need to adjust it to work correctly with guard_memory() | |
2164 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); | |
2165 address base = stack_red_zone_base() - stack_red_zone_size(); | |
2166 | |
2167 guarantee(base < stack_base(),"Error calculating stack red zone"); | |
2168 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone"); | |
2169 | |
2170 if(!os::guard_memory((char *) base, stack_red_zone_size())) { | |
2171 warning("Attempt to guard stack red zone failed."); | |
2172 } | |
2173 } | |
2174 | |
2175 void JavaThread::disable_stack_red_zone() { | |
2176 // The base notation is from the stacks point of view, growing downward. | |
2177 // We need to adjust it to work correctly with guard_memory() | |
2178 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); | |
2179 address base = stack_red_zone_base() - stack_red_zone_size(); | |
2180 if (!os::unguard_memory((char *)base, stack_red_zone_size())) { | |
2181 warning("Attempt to unguard stack red zone failed."); | |
2182 } | |
2183 } | |
2184 | |
2185 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { | |
2186 // ignore is there is no stack | |
2187 if (!has_last_Java_frame()) return; | |
2188 // traverse the stack frames. Starts from top frame. | |
2189 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { | |
2190 frame* fr = fst.current(); | |
2191 f(fr, fst.register_map()); | |
2192 } | |
2193 } | |
2194 | |
2195 | |
2196 #ifndef PRODUCT | |
2197 // Deoptimization | |
2198 // Function for testing deoptimization | |
2199 void JavaThread::deoptimize() { | |
2200 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass | |
2201 StackFrameStream fst(this, UseBiasedLocking); | |
2202 bool deopt = false; // Dump stack only if a deopt actually happens. | |
2203 bool only_at = strlen(DeoptimizeOnlyAt) > 0; | |
2204 // Iterate over all frames in the thread and deoptimize | |
2205 for(; !fst.is_done(); fst.next()) { | |
2206 if(fst.current()->can_be_deoptimized()) { | |
2207 | |
2208 if (only_at) { | |
2209 // Deoptimize only at particular bcis. DeoptimizeOnlyAt | |
2210 // consists of comma or carriage return separated numbers so | |
2211 // search for the current bci in that string. | |
2212 address pc = fst.current()->pc(); | |
2213 nmethod* nm = (nmethod*) fst.current()->cb(); | |
2214 ScopeDesc* sd = nm->scope_desc_at( pc); | |
2215 char buffer[8]; | |
2216 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); | |
2217 size_t len = strlen(buffer); | |
2218 const char * found = strstr(DeoptimizeOnlyAt, buffer); | |
2219 while (found != NULL) { | |
2220 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && | |
2221 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { | |
2222 // Check that the bci found is bracketed by terminators. | |
2223 break; | |
2224 } | |
2225 found = strstr(found + 1, buffer); | |
2226 } | |
2227 if (!found) { | |
2228 continue; | |
2229 } | |
2230 } | |
2231 | |
2232 if (DebugDeoptimization && !deopt) { | |
2233 deopt = true; // One-time only print before deopt | |
2234 tty->print_cr("[BEFORE Deoptimization]"); | |
2235 trace_frames(); | |
2236 trace_stack(); | |
2237 } | |
2238 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); | |
2239 } | |
2240 } | |
2241 | |
2242 if (DebugDeoptimization && deopt) { | |
2243 tty->print_cr("[AFTER Deoptimization]"); | |
2244 trace_frames(); | |
2245 } | |
2246 } | |
2247 | |
2248 | |
2249 // Make zombies | |
2250 void JavaThread::make_zombies() { | |
2251 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { | |
2252 if (fst.current()->can_be_deoptimized()) { | |
2253 // it is a Java nmethod | |
2254 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); | |
2255 nm->make_not_entrant(); | |
2256 } | |
2257 } | |
2258 } | |
2259 #endif // PRODUCT | |
2260 | |
2261 | |
2262 void JavaThread::deoptimized_wrt_marked_nmethods() { | |
2263 if (!has_last_Java_frame()) return; | |
2264 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass | |
2265 StackFrameStream fst(this, UseBiasedLocking); | |
2266 for(; !fst.is_done(); fst.next()) { | |
2267 if (fst.current()->should_be_deoptimized()) { | |
2268 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); | |
2269 } | |
2270 } | |
2271 } | |
2272 | |
2273 | |
2274 // GC support | |
2275 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); } | |
2276 | |
2277 void JavaThread::gc_epilogue() { | |
2278 frames_do(frame_gc_epilogue); | |
2279 } | |
2280 | |
2281 | |
2282 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); } | |
2283 | |
2284 void JavaThread::gc_prologue() { | |
2285 frames_do(frame_gc_prologue); | |
2286 } | |
2287 | |
2288 | |
2289 void JavaThread::oops_do(OopClosure* f) { | |
2290 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do | |
2291 // since there may be more than one thread using each ThreadProfiler. | |
2292 | |
2293 // Traverse the GCHandles | |
2294 Thread::oops_do(f); | |
2295 | |
2296 assert( (!has_last_Java_frame() && java_call_counter() == 0) || | |
2297 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); | |
2298 | |
2299 if (has_last_Java_frame()) { | |
2300 | |
2301 // Traverse the privileged stack | |
2302 if (_privileged_stack_top != NULL) { | |
2303 _privileged_stack_top->oops_do(f); | |
2304 } | |
2305 | |
2306 // traverse the registered growable array | |
2307 if (_array_for_gc != NULL) { | |
2308 for (int index = 0; index < _array_for_gc->length(); index++) { | |
2309 f->do_oop(_array_for_gc->adr_at(index)); | |
2310 } | |
2311 } | |
2312 | |
2313 // Traverse the monitor chunks | |
2314 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { | |
2315 chunk->oops_do(f); | |
2316 } | |
2317 | |
2318 // Traverse the execution stack | |
2319 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { | |
2320 fst.current()->oops_do(f, fst.register_map()); | |
2321 } | |
2322 } | |
2323 | |
2324 // callee_target is never live across a gc point so NULL it here should | |
2325 // it still contain a methdOop. | |
2326 | |
2327 set_callee_target(NULL); | |
2328 | |
2329 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!"); | |
2330 // If we have deferred set_locals there might be oops waiting to be | |
2331 // written | |
2332 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals(); | |
2333 if (list != NULL) { | |
2334 for (int i = 0; i < list->length(); i++) { | |
2335 list->at(i)->oops_do(f); | |
2336 } | |
2337 } | |
2338 | |
2339 // Traverse instance variables at the end since the GC may be moving things | |
2340 // around using this function | |
2341 f->do_oop((oop*) &_threadObj); | |
2342 f->do_oop((oop*) &_vm_result); | |
2343 f->do_oop((oop*) &_vm_result_2); | |
2344 f->do_oop((oop*) &_exception_oop); | |
2345 f->do_oop((oop*) &_pending_async_exception); | |
2346 | |
2347 if (jvmti_thread_state() != NULL) { | |
2348 jvmti_thread_state()->oops_do(f); | |
2349 } | |
2350 } | |
2351 | |
2352 void JavaThread::nmethods_do() { | |
2353 // Traverse the GCHandles | |
2354 Thread::nmethods_do(); | |
2355 | |
2356 assert( (!has_last_Java_frame() && java_call_counter() == 0) || | |
2357 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); | |
2358 | |
2359 if (has_last_Java_frame()) { | |
2360 // Traverse the execution stack | |
2361 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { | |
2362 fst.current()->nmethods_do(); | |
2363 } | |
2364 } | |
2365 } | |
2366 | |
2367 // Printing | |
2368 const char* _get_thread_state_name(JavaThreadState _thread_state) { | |
2369 switch (_thread_state) { | |
2370 case _thread_uninitialized: return "_thread_uninitialized"; | |
2371 case _thread_new: return "_thread_new"; | |
2372 case _thread_new_trans: return "_thread_new_trans"; | |
2373 case _thread_in_native: return "_thread_in_native"; | |
2374 case _thread_in_native_trans: return "_thread_in_native_trans"; | |
2375 case _thread_in_vm: return "_thread_in_vm"; | |
2376 case _thread_in_vm_trans: return "_thread_in_vm_trans"; | |
2377 case _thread_in_Java: return "_thread_in_Java"; | |
2378 case _thread_in_Java_trans: return "_thread_in_Java_trans"; | |
2379 case _thread_blocked: return "_thread_blocked"; | |
2380 case _thread_blocked_trans: return "_thread_blocked_trans"; | |
2381 default: return "unknown thread state"; | |
2382 } | |
2383 } | |
2384 | |
2385 #ifndef PRODUCT | |
2386 void JavaThread::print_thread_state_on(outputStream *st) const { | |
2387 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); | |
2388 }; | |
2389 void JavaThread::print_thread_state() const { | |
2390 print_thread_state_on(tty); | |
2391 }; | |
2392 #endif // PRODUCT | |
2393 | |
2394 // Called by Threads::print() for VM_PrintThreads operation | |
2395 void JavaThread::print_on(outputStream *st) const { | |
2396 st->print("\"%s\" ", get_thread_name()); | |
2397 oop thread_oop = threadObj(); | |
2398 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); | |
2399 Thread::print_on(st); | |
2400 // print guess for valid stack memory region (assume 4K pages); helps lock debugging | |
2401 st->print_cr("[" INTPTR_FORMAT ".." INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12), highest_lock()); | |
2402 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) { | |
2403 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); | |
2404 } | |
2405 #ifndef PRODUCT | |
2406 print_thread_state_on(st); | |
2407 _safepoint_state->print_on(st); | |
2408 #endif // PRODUCT | |
2409 } | |
2410 | |
2411 // Called by fatal error handler. The difference between this and | |
2412 // JavaThread::print() is that we can't grab lock or allocate memory. | |
2413 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { | |
2414 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen)); | |
2415 oop thread_obj = threadObj(); | |
2416 if (thread_obj != NULL) { | |
2417 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon"); | |
2418 } | |
2419 st->print(" ["); | |
2420 st->print("%s", _get_thread_state_name(_thread_state)); | |
2421 if (osthread()) { | |
2422 st->print(", id=%d", osthread()->thread_id()); | |
2423 } | |
2424 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")", | |
2425 _stack_base - _stack_size, _stack_base); | |
2426 st->print("]"); | |
2427 return; | |
2428 } | |
2429 | |
2430 // Verification | |
2431 | |
2432 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } | |
2433 | |
2434 void JavaThread::verify() { | |
2435 // Verify oops in the thread. | |
2436 oops_do(&VerifyOopClosure::verify_oop); | |
2437 | |
2438 // Verify the stack frames. | |
2439 frames_do(frame_verify); | |
2440 } | |
2441 | |
2442 // CR 6300358 (sub-CR 2137150) | |
2443 // Most callers of this method assume that it can't return NULL but a | |
2444 // thread may not have a name whilst it is in the process of attaching to | |
2445 // the VM - see CR 6412693, and there are places where a JavaThread can be | |
2446 // seen prior to having it's threadObj set (eg JNI attaching threads and | |
2447 // if vm exit occurs during initialization). These cases can all be accounted | |
2448 // for such that this method never returns NULL. | |
2449 const char* JavaThread::get_thread_name() const { | |
2450 #ifdef ASSERT | |
2451 // early safepoints can hit while current thread does not yet have TLS | |
2452 if (!SafepointSynchronize::is_at_safepoint()) { | |
2453 Thread *cur = Thread::current(); | |
2454 if (!(cur->is_Java_thread() && cur == this)) { | |
2455 // Current JavaThreads are allowed to get their own name without | |
2456 // the Threads_lock. | |
2457 assert_locked_or_safepoint(Threads_lock); | |
2458 } | |
2459 } | |
2460 #endif // ASSERT | |
2461 return get_thread_name_string(); | |
2462 } | |
2463 | |
2464 // Returns a non-NULL representation of this thread's name, or a suitable | |
2465 // descriptive string if there is no set name | |
2466 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { | |
2467 const char* name_str; | |
2468 oop thread_obj = threadObj(); | |
2469 if (thread_obj != NULL) { | |
2470 typeArrayOop name = java_lang_Thread::name(thread_obj); | |
2471 if (name != NULL) { | |
2472 if (buf == NULL) { | |
2473 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); | |
2474 } | |
2475 else { | |
2476 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen); | |
2477 } | |
2478 } | |
2479 else if (is_attaching()) { // workaround for 6412693 - see 6404306 | |
2480 name_str = "<no-name - thread is attaching>"; | |
2481 } | |
2482 else { | |
2483 name_str = Thread::name(); | |
2484 } | |
2485 } | |
2486 else { | |
2487 name_str = Thread::name(); | |
2488 } | |
2489 assert(name_str != NULL, "unexpected NULL thread name"); | |
2490 return name_str; | |
2491 } | |
2492 | |
2493 | |
2494 const char* JavaThread::get_threadgroup_name() const { | |
2495 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) | |
2496 oop thread_obj = threadObj(); | |
2497 if (thread_obj != NULL) { | |
2498 oop thread_group = java_lang_Thread::threadGroup(thread_obj); | |
2499 if (thread_group != NULL) { | |
2500 typeArrayOop name = java_lang_ThreadGroup::name(thread_group); | |
2501 // ThreadGroup.name can be null | |
2502 if (name != NULL) { | |
2503 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); | |
2504 return str; | |
2505 } | |
2506 } | |
2507 } | |
2508 return NULL; | |
2509 } | |
2510 | |
2511 const char* JavaThread::get_parent_name() const { | |
2512 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) | |
2513 oop thread_obj = threadObj(); | |
2514 if (thread_obj != NULL) { | |
2515 oop thread_group = java_lang_Thread::threadGroup(thread_obj); | |
2516 if (thread_group != NULL) { | |
2517 oop parent = java_lang_ThreadGroup::parent(thread_group); | |
2518 if (parent != NULL) { | |
2519 typeArrayOop name = java_lang_ThreadGroup::name(parent); | |
2520 // ThreadGroup.name can be null | |
2521 if (name != NULL) { | |
2522 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); | |
2523 return str; | |
2524 } | |
2525 } | |
2526 } | |
2527 } | |
2528 return NULL; | |
2529 } | |
2530 | |
2531 ThreadPriority JavaThread::java_priority() const { | |
2532 oop thr_oop = threadObj(); | |
2533 if (thr_oop == NULL) return NormPriority; // Bootstrapping | |
2534 ThreadPriority priority = java_lang_Thread::priority(thr_oop); | |
2535 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); | |
2536 return priority; | |
2537 } | |
2538 | |
2539 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { | |
2540 | |
2541 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); | |
2542 // Link Java Thread object <-> C++ Thread | |
2543 | |
2544 // Get the C++ thread object (an oop) from the JNI handle (a jthread) | |
2545 // and put it into a new Handle. The Handle "thread_oop" can then | |
2546 // be used to pass the C++ thread object to other methods. | |
2547 | |
2548 // Set the Java level thread object (jthread) field of the | |
2549 // new thread (a JavaThread *) to C++ thread object using the | |
2550 // "thread_oop" handle. | |
2551 | |
2552 // Set the thread field (a JavaThread *) of the | |
2553 // oop representing the java_lang_Thread to the new thread (a JavaThread *). | |
2554 | |
2555 Handle thread_oop(Thread::current(), | |
2556 JNIHandles::resolve_non_null(jni_thread)); | |
2557 assert(instanceKlass::cast(thread_oop->klass())->is_linked(), | |
2558 "must be initialized"); | |
2559 set_threadObj(thread_oop()); | |
2560 java_lang_Thread::set_thread(thread_oop(), this); | |
2561 | |
2562 if (prio == NoPriority) { | |
2563 prio = java_lang_Thread::priority(thread_oop()); | |
2564 assert(prio != NoPriority, "A valid priority should be present"); | |
2565 } | |
2566 | |
2567 // Push the Java priority down to the native thread; needs Threads_lock | |
2568 Thread::set_priority(this, prio); | |
2569 | |
2570 // Add the new thread to the Threads list and set it in motion. | |
2571 // We must have threads lock in order to call Threads::add. | |
2572 // It is crucial that we do not block before the thread is | |
2573 // added to the Threads list for if a GC happens, then the java_thread oop | |
2574 // will not be visited by GC. | |
2575 Threads::add(this); | |
2576 } | |
2577 | |
2578 oop JavaThread::current_park_blocker() { | |
2579 // Support for JSR-166 locks | |
2580 oop thread_oop = threadObj(); | |
2581 if (thread_oop != NULL && JDK_Version::supports_thread_park_blocker()) { | |
2582 return java_lang_Thread::park_blocker(thread_oop); | |
2583 } | |
2584 return NULL; | |
2585 } | |
2586 | |
2587 | |
2588 void JavaThread::print_stack_on(outputStream* st) { | |
2589 if (!has_last_Java_frame()) return; | |
2590 ResourceMark rm; | |
2591 HandleMark hm; | |
2592 | |
2593 RegisterMap reg_map(this); | |
2594 vframe* start_vf = last_java_vframe(®_map); | |
2595 int count = 0; | |
2596 for (vframe* f = start_vf; f; f = f->sender() ) { | |
2597 if (f->is_java_frame()) { | |
2598 javaVFrame* jvf = javaVFrame::cast(f); | |
2599 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); | |
2600 | |
2601 // Print out lock information | |
2602 if (JavaMonitorsInStackTrace) { | |
2603 jvf->print_lock_info_on(st, count); | |
2604 } | |
2605 } else { | |
2606 // Ignore non-Java frames | |
2607 } | |
2608 | |
2609 // Bail-out case for too deep stacks | |
2610 count++; | |
2611 if (MaxJavaStackTraceDepth == count) return; | |
2612 } | |
2613 } | |
2614 | |
2615 | |
2616 // JVMTI PopFrame support | |
2617 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { | |
2618 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments"); | |
2619 if (in_bytes(size_in_bytes) != 0) { | |
2620 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes)); | |
2621 _popframe_preserved_args_size = in_bytes(size_in_bytes); | |
2622 Copy::conjoint_bytes(start, _popframe_preserved_args, _popframe_preserved_args_size); | |
2623 } | |
2624 } | |
2625 | |
2626 void* JavaThread::popframe_preserved_args() { | |
2627 return _popframe_preserved_args; | |
2628 } | |
2629 | |
2630 ByteSize JavaThread::popframe_preserved_args_size() { | |
2631 return in_ByteSize(_popframe_preserved_args_size); | |
2632 } | |
2633 | |
2634 WordSize JavaThread::popframe_preserved_args_size_in_words() { | |
2635 int sz = in_bytes(popframe_preserved_args_size()); | |
2636 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); | |
2637 return in_WordSize(sz / wordSize); | |
2638 } | |
2639 | |
2640 void JavaThread::popframe_free_preserved_args() { | |
2641 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice"); | |
2642 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args); | |
2643 _popframe_preserved_args = NULL; | |
2644 _popframe_preserved_args_size = 0; | |
2645 } | |
2646 | |
2647 #ifndef PRODUCT | |
2648 | |
2649 void JavaThread::trace_frames() { | |
2650 tty->print_cr("[Describe stack]"); | |
2651 int frame_no = 1; | |
2652 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { | |
2653 tty->print(" %d. ", frame_no++); | |
2654 fst.current()->print_value_on(tty,this); | |
2655 tty->cr(); | |
2656 } | |
2657 } | |
2658 | |
2659 | |
2660 void JavaThread::trace_stack_from(vframe* start_vf) { | |
2661 ResourceMark rm; | |
2662 int vframe_no = 1; | |
2663 for (vframe* f = start_vf; f; f = f->sender() ) { | |
2664 if (f->is_java_frame()) { | |
2665 javaVFrame::cast(f)->print_activation(vframe_no++); | |
2666 } else { | |
2667 f->print(); | |
2668 } | |
2669 if (vframe_no > StackPrintLimit) { | |
2670 tty->print_cr("...<more frames>..."); | |
2671 return; | |
2672 } | |
2673 } | |
2674 } | |
2675 | |
2676 | |
2677 void JavaThread::trace_stack() { | |
2678 if (!has_last_Java_frame()) return; | |
2679 ResourceMark rm; | |
2680 HandleMark hm; | |
2681 RegisterMap reg_map(this); | |
2682 trace_stack_from(last_java_vframe(®_map)); | |
2683 } | |
2684 | |
2685 | |
2686 #endif // PRODUCT | |
2687 | |
2688 | |
2689 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) { | |
2690 assert(reg_map != NULL, "a map must be given"); | |
2691 frame f = last_frame(); | |
2692 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) { | |
2693 if (vf->is_java_frame()) return javaVFrame::cast(vf); | |
2694 } | |
2695 return NULL; | |
2696 } | |
2697 | |
2698 | |
2699 klassOop JavaThread::security_get_caller_class(int depth) { | |
2700 vframeStream vfst(this); | |
2701 vfst.security_get_caller_frame(depth); | |
2702 if (!vfst.at_end()) { | |
2703 return vfst.method()->method_holder(); | |
2704 } | |
2705 return NULL; | |
2706 } | |
2707 | |
2708 static void compiler_thread_entry(JavaThread* thread, TRAPS) { | |
2709 assert(thread->is_Compiler_thread(), "must be compiler thread"); | |
2710 CompileBroker::compiler_thread_loop(); | |
2711 } | |
2712 | |
2713 // Create a CompilerThread | |
2714 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters) | |
2715 : JavaThread(&compiler_thread_entry) { | |
2716 _env = NULL; | |
2717 _log = NULL; | |
2718 _task = NULL; | |
2719 _queue = queue; | |
2720 _counters = counters; | |
2721 | |
2722 #ifndef PRODUCT | |
2723 _ideal_graph_printer = NULL; | |
2724 #endif | |
2725 } | |
2726 | |
2727 | |
2728 // ======= Threads ======== | |
2729 | |
2730 // The Threads class links together all active threads, and provides | |
2731 // operations over all threads. It is protected by its own Mutex | |
2732 // lock, which is also used in other contexts to protect thread | |
2733 // operations from having the thread being operated on from exiting | |
2734 // and going away unexpectedly (e.g., safepoint synchronization) | |
2735 | |
2736 JavaThread* Threads::_thread_list = NULL; | |
2737 int Threads::_number_of_threads = 0; | |
2738 int Threads::_number_of_non_daemon_threads = 0; | |
2739 int Threads::_return_code = 0; | |
2740 size_t JavaThread::_stack_size_at_create = 0; | |
2741 | |
2742 // All JavaThreads | |
2743 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next()) | |
2744 | |
2745 void os_stream(); | |
2746 | |
2747 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system) | |
2748 void Threads::threads_do(ThreadClosure* tc) { | |
2749 assert_locked_or_safepoint(Threads_lock); | |
2750 // ALL_JAVA_THREADS iterates through all JavaThreads | |
2751 ALL_JAVA_THREADS(p) { | |
2752 tc->do_thread(p); | |
2753 } | |
2754 // Someday we could have a table or list of all non-JavaThreads. | |
2755 // For now, just manually iterate through them. | |
2756 tc->do_thread(VMThread::vm_thread()); | |
2757 Universe::heap()->gc_threads_do(tc); | |
2758 tc->do_thread(WatcherThread::watcher_thread()); | |
2759 // If CompilerThreads ever become non-JavaThreads, add them here | |
2760 } | |
2761 | |
2762 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) { | |
2763 | |
2764 // Check version | |
2765 if (!is_supported_jni_version(args->version)) return JNI_EVERSION; | |
2766 | |
2767 // Initialize the output stream module | |
2768 ostream_init(); | |
2769 | |
2770 // Process java launcher properties. | |
2771 Arguments::process_sun_java_launcher_properties(args); | |
2772 | |
2773 // Initialize the os module before using TLS | |
2774 os::init(); | |
2775 | |
2776 // Initialize system properties. | |
2777 Arguments::init_system_properties(); | |
2778 | |
2779 // Parse arguments | |
2780 jint parse_result = Arguments::parse(args); | |
2781 if (parse_result != JNI_OK) return parse_result; | |
2782 | |
2783 if (PauseAtStartup) { | |
2784 os::pause(); | |
2785 } | |
2786 | |
2787 HS_DTRACE_PROBE(hotspot, vm__init__begin); | |
2788 | |
2789 // Record VM creation timing statistics | |
2790 TraceVmCreationTime create_vm_timer; | |
2791 create_vm_timer.start(); | |
2792 | |
2793 // Timing (must come after argument parsing) | |
2794 TraceTime timer("Create VM", TraceStartupTime); | |
2795 | |
2796 // Initialize the os module after parsing the args | |
2797 jint os_init_2_result = os::init_2(); | |
2798 if (os_init_2_result != JNI_OK) return os_init_2_result; | |
2799 | |
2800 // Initialize output stream logging | |
2801 ostream_init_log(); | |
2802 | |
2803 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad | |
2804 // Must be before create_vm_init_agents() | |
2805 if (Arguments::init_libraries_at_startup()) { | |
2806 convert_vm_init_libraries_to_agents(); | |
2807 } | |
2808 | |
2809 // Launch -agentlib/-agentpath and converted -Xrun agents | |
2810 if (Arguments::init_agents_at_startup()) { | |
2811 create_vm_init_agents(); | |
2812 } | |
2813 | |
2814 // Initialize Threads state | |
2815 _thread_list = NULL; | |
2816 _number_of_threads = 0; | |
2817 _number_of_non_daemon_threads = 0; | |
2818 | |
2819 // Initialize TLS | |
2820 ThreadLocalStorage::init(); | |
2821 | |
2822 // Initialize global data structures and create system classes in heap | |
2823 vm_init_globals(); | |
2824 | |
2825 // Attach the main thread to this os thread | |
2826 JavaThread* main_thread = new JavaThread(); | |
2827 main_thread->set_thread_state(_thread_in_vm); | |
2828 // must do this before set_active_handles and initialize_thread_local_storage | |
2829 // Note: on solaris initialize_thread_local_storage() will (indirectly) | |
2830 // change the stack size recorded here to one based on the java thread | |
2831 // stacksize. This adjusted size is what is used to figure the placement | |
2832 // of the guard pages. | |
2833 main_thread->record_stack_base_and_size(); | |
2834 main_thread->initialize_thread_local_storage(); | |
2835 | |
2836 main_thread->set_active_handles(JNIHandleBlock::allocate_block()); | |
2837 | |
2838 if (!main_thread->set_as_starting_thread()) { | |
2839 vm_shutdown_during_initialization( | |
2840 "Failed necessary internal allocation. Out of swap space"); | |
2841 delete main_thread; | |
2842 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again | |
2843 return JNI_ENOMEM; | |
2844 } | |
2845 | |
2846 // Enable guard page *after* os::create_main_thread(), otherwise it would | |
2847 // crash Linux VM, see notes in os_linux.cpp. | |
2848 main_thread->create_stack_guard_pages(); | |
2849 | |
2850 // Initialize Java-Leve synchronization subsystem | |
2851 ObjectSynchronizer::Initialize() ; | |
2852 | |
2853 // Initialize global modules | |
2854 jint status = init_globals(); | |
2855 if (status != JNI_OK) { | |
2856 delete main_thread; | |
2857 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again | |
2858 return status; | |
2859 } | |
2860 | |
2861 HandleMark hm; | |
2862 | |
2863 { MutexLocker mu(Threads_lock); | |
2864 Threads::add(main_thread); | |
2865 } | |
2866 | |
2867 // Any JVMTI raw monitors entered in onload will transition into | |
2868 // real raw monitor. VM is setup enough here for raw monitor enter. | |
2869 JvmtiExport::transition_pending_onload_raw_monitors(); | |
2870 | |
2871 if (VerifyBeforeGC && | |
2872 Universe::heap()->total_collections() >= VerifyGCStartAt) { | |
2873 Universe::heap()->prepare_for_verify(); | |
2874 Universe::verify(); // make sure we're starting with a clean slate | |
2875 } | |
2876 | |
2877 // Create the VMThread | |
2878 { TraceTime timer("Start VMThread", TraceStartupTime); | |
2879 VMThread::create(); | |
2880 Thread* vmthread = VMThread::vm_thread(); | |
2881 | |
2882 if (!os::create_thread(vmthread, os::vm_thread)) | |
2883 vm_exit_during_initialization("Cannot create VM thread. Out of system resources."); | |
2884 | |
2885 // Wait for the VM thread to become ready, and VMThread::run to initialize | |
2886 // Monitors can have spurious returns, must always check another state flag | |
2887 { | |
2888 MutexLocker ml(Notify_lock); | |
2889 os::start_thread(vmthread); | |
2890 while (vmthread->active_handles() == NULL) { | |
2891 Notify_lock->wait(); | |
2892 } | |
2893 } | |
2894 } | |
2895 | |
2896 assert (Universe::is_fully_initialized(), "not initialized"); | |
2897 EXCEPTION_MARK; | |
2898 | |
2899 // At this point, the Universe is initialized, but we have not executed | |
2900 // any byte code. Now is a good time (the only time) to dump out the | |
2901 // internal state of the JVM for sharing. | |
2902 | |
2903 if (DumpSharedSpaces) { | |
2904 Universe::heap()->preload_and_dump(CHECK_0); | |
2905 ShouldNotReachHere(); | |
2906 } | |
2907 | |
2908 // Always call even when there are not JVMTI environments yet, since environments | |
2909 // may be attached late and JVMTI must track phases of VM execution | |
2910 JvmtiExport::enter_start_phase(); | |
2911 | |
2912 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. | |
2913 JvmtiExport::post_vm_start(); | |
2914 | |
2915 { | |
2916 TraceTime timer("Initialize java.lang classes", TraceStartupTime); | |
2917 | |
2918 if (EagerXrunInit && Arguments::init_libraries_at_startup()) { | |
2919 create_vm_init_libraries(); | |
2920 } | |
2921 | |
2922 if (InitializeJavaLangString) { | |
2923 initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0); | |
2924 } else { | |
2925 warning("java.lang.String not initialized"); | |
2926 } | |
2927 | |
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2928 if (AggressiveOpts) { |
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2929 // Forcibly initialize java/util/HashMap and mutate the private |
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2930 // static final "frontCacheEnabled" field before we start creating instances |
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2931 #ifdef ASSERT |
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2932 klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); |
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2933 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet"); |
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2934 #endif |
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2935 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); |
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2936 KlassHandle k = KlassHandle(THREAD, k_o); |
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2937 guarantee(k.not_null(), "Must find java/util/HashMap"); |
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2938 instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); |
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2939 ik->initialize(CHECK_0); |
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2940 fieldDescriptor fd; |
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2941 // Possible we might not find this field; if so, don't break |
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2942 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { |
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2943 k()->bool_field_put(fd.offset(), true); |
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2944 } |
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2945 } |
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2946 |
0 | 2947 // Initialize java_lang.System (needed before creating the thread) |
2948 if (InitializeJavaLangSystem) { | |
2949 initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0); | |
2950 initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0); | |
2951 Handle thread_group = create_initial_thread_group(CHECK_0); | |
2952 Universe::set_main_thread_group(thread_group()); | |
2953 initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0); | |
2954 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0); | |
2955 main_thread->set_threadObj(thread_object); | |
2956 // Set thread status to running since main thread has | |
2957 // been started and running. | |
2958 java_lang_Thread::set_thread_status(thread_object, | |
2959 java_lang_Thread::RUNNABLE); | |
2960 | |
2961 // The VM preresolve methods to these classes. Make sure that get initialized | |
2962 initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0); | |
2963 initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0); | |
2964 // The VM creates & returns objects of this class. Make sure it's initialized. | |
2965 initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0); | |
2966 call_initializeSystemClass(CHECK_0); | |
2967 } else { | |
2968 warning("java.lang.System not initialized"); | |
2969 } | |
2970 | |
2971 // an instance of OutOfMemory exception has been allocated earlier | |
2972 if (InitializeJavaLangExceptionsErrors) { | |
2973 initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0); | |
2974 initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0); | |
2975 initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0); | |
2976 initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0); | |
2977 initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0); | |
2978 initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0); | |
2979 initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0); | |
2980 } else { | |
2981 warning("java.lang.OutOfMemoryError has not been initialized"); | |
2982 warning("java.lang.NullPointerException has not been initialized"); | |
2983 warning("java.lang.ClassCastException has not been initialized"); | |
2984 warning("java.lang.ArrayStoreException has not been initialized"); | |
2985 warning("java.lang.ArithmeticException has not been initialized"); | |
2986 warning("java.lang.StackOverflowError has not been initialized"); | |
2987 } | |
2988 } | |
2989 | |
2990 // See : bugid 4211085. | |
2991 // Background : the static initializer of java.lang.Compiler tries to read | |
2992 // property"java.compiler" and read & write property "java.vm.info". | |
2993 // When a security manager is installed through the command line | |
2994 // option "-Djava.security.manager", the above properties are not | |
2995 // readable and the static initializer for java.lang.Compiler fails | |
2996 // resulting in a NoClassDefFoundError. This can happen in any | |
2997 // user code which calls methods in java.lang.Compiler. | |
2998 // Hack : the hack is to pre-load and initialize this class, so that only | |
2999 // system domains are on the stack when the properties are read. | |
3000 // Currently even the AWT code has calls to methods in java.lang.Compiler. | |
3001 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT. | |
3002 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and | |
3003 // read and write"java.vm.info" in the default policy file. See bugid 4211383 | |
3004 // Once that is done, we should remove this hack. | |
3005 initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0); | |
3006 | |
3007 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to | |
3008 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot | |
3009 // compiler does not get loaded through java.lang.Compiler). "java -version" with the | |
3010 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here. | |
3011 // This should also be taken out as soon as 4211383 gets fixed. | |
3012 reset_vm_info_property(CHECK_0); | |
3013 | |
3014 quicken_jni_functions(); | |
3015 | |
3016 // Set flag that basic initialization has completed. Used by exceptions and various | |
3017 // debug stuff, that does not work until all basic classes have been initialized. | |
3018 set_init_completed(); | |
3019 | |
3020 HS_DTRACE_PROBE(hotspot, vm__init__end); | |
3021 | |
3022 // record VM initialization completion time | |
3023 Management::record_vm_init_completed(); | |
3024 | |
3025 // Compute system loader. Note that this has to occur after set_init_completed, since | |
3026 // valid exceptions may be thrown in the process. | |
3027 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and | |
3028 // set_init_completed has just been called, causing exceptions not to be shortcut | |
3029 // anymore. We call vm_exit_during_initialization directly instead. | |
3030 SystemDictionary::compute_java_system_loader(THREAD); | |
3031 if (HAS_PENDING_EXCEPTION) { | |
3032 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); | |
3033 } | |
3034 | |
3035 #ifndef SERIALGC | |
3036 // Support for ConcurrentMarkSweep. This should be cleaned up | |
3037 // and better encapsulated. XXX YSR | |
3038 if (UseConcMarkSweepGC) { | |
3039 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD); | |
3040 if (HAS_PENDING_EXCEPTION) { | |
3041 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); | |
3042 } | |
3043 } | |
3044 #endif // SERIALGC | |
3045 | |
3046 // Always call even when there are not JVMTI environments yet, since environments | |
3047 // may be attached late and JVMTI must track phases of VM execution | |
3048 JvmtiExport::enter_live_phase(); | |
3049 | |
3050 // Signal Dispatcher needs to be started before VMInit event is posted | |
3051 os::signal_init(); | |
3052 | |
3053 // Start Attach Listener if +StartAttachListener or it can't be started lazily | |
3054 if (!DisableAttachMechanism) { | |
3055 if (StartAttachListener || AttachListener::init_at_startup()) { | |
3056 AttachListener::init(); | |
3057 } | |
3058 } | |
3059 | |
3060 // Launch -Xrun agents | |
3061 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP | |
3062 // back-end can launch with -Xdebug -Xrunjdwp. | |
3063 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) { | |
3064 create_vm_init_libraries(); | |
3065 } | |
3066 | |
3067 // Notify JVMTI agents that VM initialization is complete - nop if no agents. | |
3068 JvmtiExport::post_vm_initialized(); | |
3069 | |
3070 Chunk::start_chunk_pool_cleaner_task(); | |
3071 | |
3072 // initialize compiler(s) | |
3073 CompileBroker::compilation_init(); | |
3074 | |
3075 Management::initialize(THREAD); | |
3076 if (HAS_PENDING_EXCEPTION) { | |
3077 // management agent fails to start possibly due to | |
3078 // configuration problem and is responsible for printing | |
3079 // stack trace if appropriate. Simply exit VM. | |
3080 vm_exit(1); | |
3081 } | |
3082 | |
3083 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true); | |
3084 if (Arguments::has_alloc_profile()) AllocationProfiler::engage(); | |
3085 if (MemProfiling) MemProfiler::engage(); | |
3086 StatSampler::engage(); | |
3087 if (CheckJNICalls) JniPeriodicChecker::engage(); | |
3088 | |
3089 BiasedLocking::init(); | |
3090 | |
3091 | |
3092 // Start up the WatcherThread if there are any periodic tasks | |
3093 // NOTE: All PeriodicTasks should be registered by now. If they | |
3094 // aren't, late joiners might appear to start slowly (we might | |
3095 // take a while to process their first tick). | |
3096 if (PeriodicTask::num_tasks() > 0) { | |
3097 WatcherThread::start(); | |
3098 } | |
3099 | |
3100 create_vm_timer.end(); | |
3101 return JNI_OK; | |
3102 } | |
3103 | |
3104 // type for the Agent_OnLoad and JVM_OnLoad entry points | |
3105 extern "C" { | |
3106 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *); | |
3107 } | |
3108 // Find a command line agent library and return its entry point for | |
3109 // -agentlib: -agentpath: -Xrun | |
3110 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array. | |
3111 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) { | |
3112 OnLoadEntry_t on_load_entry = NULL; | |
3113 void *library = agent->os_lib(); // check if we have looked it up before | |
3114 | |
3115 if (library == NULL) { | |
3116 char buffer[JVM_MAXPATHLEN]; | |
3117 char ebuf[1024]; | |
3118 const char *name = agent->name(); | |
3119 | |
3120 if (agent->is_absolute_path()) { | |
3121 library = hpi::dll_load(name, ebuf, sizeof ebuf); | |
3122 if (library == NULL) { | |
3123 // If we can't find the agent, exit. | |
3124 vm_exit_during_initialization("Could not find agent library in absolute path", name); | |
3125 } | |
3126 } else { | |
3127 // Try to load the agent from the standard dll directory | |
3128 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name); | |
3129 library = hpi::dll_load(buffer, ebuf, sizeof ebuf); | |
3130 #ifdef KERNEL | |
3131 // Download instrument dll | |
3132 if (library == NULL && strcmp(name, "instrument") == 0) { | |
3133 char *props = Arguments::get_kernel_properties(); | |
3134 char *home = Arguments::get_java_home(); | |
3135 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false" | |
3136 " sun.jkernel.DownloadManager -download client_jvm"; | |
3137 int length = strlen(props) + strlen(home) + strlen(fmt) + 1; | |
3138 char *cmd = AllocateHeap(length); | |
3139 jio_snprintf(cmd, length, fmt, home, props); | |
3140 int status = os::fork_and_exec(cmd); | |
3141 FreeHeap(props); | |
3142 FreeHeap(cmd); | |
3143 if (status == -1) { | |
3144 warning(cmd); | |
3145 vm_exit_during_initialization("fork_and_exec failed: %s", | |
3146 strerror(errno)); | |
3147 } | |
3148 // when this comes back the instrument.dll should be where it belongs. | |
3149 library = hpi::dll_load(buffer, ebuf, sizeof ebuf); | |
3150 } | |
3151 #endif // KERNEL | |
3152 if (library == NULL) { // Try the local directory | |
3153 char ns[1] = {0}; | |
3154 hpi::dll_build_name(buffer, sizeof(buffer), ns, name); | |
3155 library = hpi::dll_load(buffer, ebuf, sizeof ebuf); | |
3156 if (library == NULL) { | |
3157 // If we can't find the agent, exit. | |
3158 vm_exit_during_initialization("Could not find agent library on the library path or in the local directory", name); | |
3159 } | |
3160 } | |
3161 } | |
3162 agent->set_os_lib(library); | |
3163 } | |
3164 | |
3165 // Find the OnLoad function. | |
3166 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) { | |
3167 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index])); | |
3168 if (on_load_entry != NULL) break; | |
3169 } | |
3170 return on_load_entry; | |
3171 } | |
3172 | |
3173 // Find the JVM_OnLoad entry point | |
3174 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) { | |
3175 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS; | |
3176 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); | |
3177 } | |
3178 | |
3179 // Find the Agent_OnLoad entry point | |
3180 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) { | |
3181 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS; | |
3182 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); | |
3183 } | |
3184 | |
3185 // For backwards compatibility with -Xrun | |
3186 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be | |
3187 // treated like -agentpath: | |
3188 // Must be called before agent libraries are created | |
3189 void Threads::convert_vm_init_libraries_to_agents() { | |
3190 AgentLibrary* agent; | |
3191 AgentLibrary* next; | |
3192 | |
3193 for (agent = Arguments::libraries(); agent != NULL; agent = next) { | |
3194 next = agent->next(); // cache the next agent now as this agent may get moved off this list | |
3195 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); | |
3196 | |
3197 // If there is an JVM_OnLoad function it will get called later, | |
3198 // otherwise see if there is an Agent_OnLoad | |
3199 if (on_load_entry == NULL) { | |
3200 on_load_entry = lookup_agent_on_load(agent); | |
3201 if (on_load_entry != NULL) { | |
3202 // switch it to the agent list -- so that Agent_OnLoad will be called, | |
3203 // JVM_OnLoad won't be attempted and Agent_OnUnload will | |
3204 Arguments::convert_library_to_agent(agent); | |
3205 } else { | |
3206 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name()); | |
3207 } | |
3208 } | |
3209 } | |
3210 } | |
3211 | |
3212 // Create agents for -agentlib: -agentpath: and converted -Xrun | |
3213 // Invokes Agent_OnLoad | |
3214 // Called very early -- before JavaThreads exist | |
3215 void Threads::create_vm_init_agents() { | |
3216 extern struct JavaVM_ main_vm; | |
3217 AgentLibrary* agent; | |
3218 | |
3219 JvmtiExport::enter_onload_phase(); | |
3220 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) { | |
3221 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent); | |
3222 | |
3223 if (on_load_entry != NULL) { | |
3224 // Invoke the Agent_OnLoad function | |
3225 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); | |
3226 if (err != JNI_OK) { | |
3227 vm_exit_during_initialization("agent library failed to init", agent->name()); | |
3228 } | |
3229 } else { | |
3230 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name()); | |
3231 } | |
3232 } | |
3233 JvmtiExport::enter_primordial_phase(); | |
3234 } | |
3235 | |
3236 extern "C" { | |
3237 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *); | |
3238 } | |
3239 | |
3240 void Threads::shutdown_vm_agents() { | |
3241 // Send any Agent_OnUnload notifications | |
3242 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS; | |
3243 extern struct JavaVM_ main_vm; | |
3244 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) { | |
3245 | |
3246 // Find the Agent_OnUnload function. | |
3247 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) { | |
3248 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t, | |
3249 hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index])); | |
3250 | |
3251 // Invoke the Agent_OnUnload function | |
3252 if (unload_entry != NULL) { | |
3253 JavaThread* thread = JavaThread::current(); | |
3254 ThreadToNativeFromVM ttn(thread); | |
3255 HandleMark hm(thread); | |
3256 (*unload_entry)(&main_vm); | |
3257 break; | |
3258 } | |
3259 } | |
3260 } | |
3261 } | |
3262 | |
3263 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries | |
3264 // Invokes JVM_OnLoad | |
3265 void Threads::create_vm_init_libraries() { | |
3266 extern struct JavaVM_ main_vm; | |
3267 AgentLibrary* agent; | |
3268 | |
3269 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) { | |
3270 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); | |
3271 | |
3272 if (on_load_entry != NULL) { | |
3273 // Invoke the JVM_OnLoad function | |
3274 JavaThread* thread = JavaThread::current(); | |
3275 ThreadToNativeFromVM ttn(thread); | |
3276 HandleMark hm(thread); | |
3277 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); | |
3278 if (err != JNI_OK) { | |
3279 vm_exit_during_initialization("-Xrun library failed to init", agent->name()); | |
3280 } | |
3281 } else { | |
3282 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name()); | |
3283 } | |
3284 } | |
3285 } | |
3286 | |
3287 // Last thread running calls java.lang.Shutdown.shutdown() | |
3288 void JavaThread::invoke_shutdown_hooks() { | |
3289 HandleMark hm(this); | |
3290 | |
3291 // We could get here with a pending exception, if so clear it now. | |
3292 if (this->has_pending_exception()) { | |
3293 this->clear_pending_exception(); | |
3294 } | |
3295 | |
3296 EXCEPTION_MARK; | |
3297 klassOop k = | |
3298 SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(), | |
3299 THREAD); | |
3300 if (k != NULL) { | |
3301 // SystemDictionary::resolve_or_null will return null if there was | |
3302 // an exception. If we cannot load the Shutdown class, just don't | |
3303 // call Shutdown.shutdown() at all. This will mean the shutdown hooks | |
3304 // and finalizers (if runFinalizersOnExit is set) won't be run. | |
3305 // Note that if a shutdown hook was registered or runFinalizersOnExit | |
3306 // was called, the Shutdown class would have already been loaded | |
3307 // (Runtime.addShutdownHook and runFinalizersOnExit will load it). | |
3308 instanceKlassHandle shutdown_klass (THREAD, k); | |
3309 JavaValue result(T_VOID); | |
3310 JavaCalls::call_static(&result, | |
3311 shutdown_klass, | |
3312 vmSymbolHandles::shutdown_method_name(), | |
3313 vmSymbolHandles::void_method_signature(), | |
3314 THREAD); | |
3315 } | |
3316 CLEAR_PENDING_EXCEPTION; | |
3317 } | |
3318 | |
3319 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when | |
3320 // the program falls off the end of main(). Another VM exit path is through | |
3321 // vm_exit() when the program calls System.exit() to return a value or when | |
3322 // there is a serious error in VM. The two shutdown paths are not exactly | |
3323 // the same, but they share Shutdown.shutdown() at Java level and before_exit() | |
3324 // and VM_Exit op at VM level. | |
3325 // | |
3326 // Shutdown sequence: | |
3327 // + Wait until we are the last non-daemon thread to execute | |
3328 // <-- every thing is still working at this moment --> | |
3329 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level | |
3330 // shutdown hooks, run finalizers if finalization-on-exit | |
3331 // + Call before_exit(), prepare for VM exit | |
3332 // > run VM level shutdown hooks (they are registered through JVM_OnExit(), | |
3333 // currently the only user of this mechanism is File.deleteOnExit()) | |
3334 // > stop flat profiler, StatSampler, watcher thread, CMS threads, | |
3335 // post thread end and vm death events to JVMTI, | |
3336 // stop signal thread | |
3337 // + Call JavaThread::exit(), it will: | |
3338 // > release JNI handle blocks, remove stack guard pages | |
3339 // > remove this thread from Threads list | |
3340 // <-- no more Java code from this thread after this point --> | |
3341 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop | |
3342 // the compiler threads at safepoint | |
3343 // <-- do not use anything that could get blocked by Safepoint --> | |
3344 // + Disable tracing at JNI/JVM barriers | |
3345 // + Set _vm_exited flag for threads that are still running native code | |
3346 // + Delete this thread | |
3347 // + Call exit_globals() | |
3348 // > deletes tty | |
3349 // > deletes PerfMemory resources | |
3350 // + Return to caller | |
3351 | |
3352 bool Threads::destroy_vm() { | |
3353 JavaThread* thread = JavaThread::current(); | |
3354 | |
3355 // Wait until we are the last non-daemon thread to execute | |
3356 { MutexLocker nu(Threads_lock); | |
3357 while (Threads::number_of_non_daemon_threads() > 1 ) | |
3358 // This wait should make safepoint checks, wait without a timeout, | |
3359 // and wait as a suspend-equivalent condition. | |
3360 // | |
3361 // Note: If the FlatProfiler is running and this thread is waiting | |
3362 // for another non-daemon thread to finish, then the FlatProfiler | |
3363 // is waiting for the external suspend request on this thread to | |
3364 // complete. wait_for_ext_suspend_completion() will eventually | |
3365 // timeout, but that takes time. Making this wait a suspend- | |
3366 // equivalent condition solves that timeout problem. | |
3367 // | |
3368 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0, | |
3369 Mutex::_as_suspend_equivalent_flag); | |
3370 } | |
3371 | |
3372 // Hang forever on exit if we are reporting an error. | |
3373 if (ShowMessageBoxOnError && is_error_reported()) { | |
3374 os::infinite_sleep(); | |
3375 } | |
3376 | |
3377 if (JDK_Version::is_jdk12x_version()) { | |
3378 // We are the last thread running, so check if finalizers should be run. | |
3379 // For 1.3 or later this is done in thread->invoke_shutdown_hooks() | |
3380 HandleMark rm(thread); | |
3381 Universe::run_finalizers_on_exit(); | |
3382 } else { | |
3383 // run Java level shutdown hooks | |
3384 thread->invoke_shutdown_hooks(); | |
3385 } | |
3386 | |
3387 before_exit(thread); | |
3388 | |
3389 thread->exit(true); | |
3390 | |
3391 // Stop VM thread. | |
3392 { | |
3393 // 4945125 The vm thread comes to a safepoint during exit. | |
3394 // GC vm_operations can get caught at the safepoint, and the | |
3395 // heap is unparseable if they are caught. Grab the Heap_lock | |
3396 // to prevent this. The GC vm_operations will not be able to | |
3397 // queue until after the vm thread is dead. | |
3398 MutexLocker ml(Heap_lock); | |
3399 | |
3400 VMThread::wait_for_vm_thread_exit(); | |
3401 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint"); | |
3402 VMThread::destroy(); | |
3403 } | |
3404 | |
3405 // clean up ideal graph printers | |
3406 #if defined(COMPILER2) && !defined(PRODUCT) | |
3407 IdealGraphPrinter::clean_up(); | |
3408 #endif | |
3409 | |
3410 // Now, all Java threads are gone except daemon threads. Daemon threads | |
3411 // running Java code or in VM are stopped by the Safepoint. However, | |
3412 // daemon threads executing native code are still running. But they | |
3413 // will be stopped at native=>Java/VM barriers. Note that we can't | |
3414 // simply kill or suspend them, as it is inherently deadlock-prone. | |
3415 | |
3416 #ifndef PRODUCT | |
3417 // disable function tracing at JNI/JVM barriers | |
3418 TraceHPI = false; | |
3419 TraceJNICalls = false; | |
3420 TraceJVMCalls = false; | |
3421 TraceRuntimeCalls = false; | |
3422 #endif | |
3423 | |
3424 VM_Exit::set_vm_exited(); | |
3425 | |
3426 notify_vm_shutdown(); | |
3427 | |
3428 delete thread; | |
3429 | |
3430 // exit_globals() will delete tty | |
3431 exit_globals(); | |
3432 | |
3433 return true; | |
3434 } | |
3435 | |
3436 | |
3437 jboolean Threads::is_supported_jni_version_including_1_1(jint version) { | |
3438 if (version == JNI_VERSION_1_1) return JNI_TRUE; | |
3439 return is_supported_jni_version(version); | |
3440 } | |
3441 | |
3442 | |
3443 jboolean Threads::is_supported_jni_version(jint version) { | |
3444 if (version == JNI_VERSION_1_2) return JNI_TRUE; | |
3445 if (version == JNI_VERSION_1_4) return JNI_TRUE; | |
3446 if (version == JNI_VERSION_1_6) return JNI_TRUE; | |
3447 return JNI_FALSE; | |
3448 } | |
3449 | |
3450 | |
3451 void Threads::add(JavaThread* p, bool force_daemon) { | |
3452 // The threads lock must be owned at this point | |
3453 assert_locked_or_safepoint(Threads_lock); | |
3454 p->set_next(_thread_list); | |
3455 _thread_list = p; | |
3456 _number_of_threads++; | |
3457 oop threadObj = p->threadObj(); | |
3458 bool daemon = true; | |
3459 // Bootstrapping problem: threadObj can be null for initial | |
3460 // JavaThread (or for threads attached via JNI) | |
3461 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) { | |
3462 _number_of_non_daemon_threads++; | |
3463 daemon = false; | |
3464 } | |
3465 | |
3466 ThreadService::add_thread(p, daemon); | |
3467 | |
3468 // Possible GC point. | |
3469 Events::log("Thread added: " INTPTR_FORMAT, p); | |
3470 } | |
3471 | |
3472 void Threads::remove(JavaThread* p) { | |
3473 // Extra scope needed for Thread_lock, so we can check | |
3474 // that we do not remove thread without safepoint code notice | |
3475 { MutexLocker ml(Threads_lock); | |
3476 | |
3477 assert(includes(p), "p must be present"); | |
3478 | |
3479 JavaThread* current = _thread_list; | |
3480 JavaThread* prev = NULL; | |
3481 | |
3482 while (current != p) { | |
3483 prev = current; | |
3484 current = current->next(); | |
3485 } | |
3486 | |
3487 if (prev) { | |
3488 prev->set_next(current->next()); | |
3489 } else { | |
3490 _thread_list = p->next(); | |
3491 } | |
3492 _number_of_threads--; | |
3493 oop threadObj = p->threadObj(); | |
3494 bool daemon = true; | |
3495 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) { | |
3496 _number_of_non_daemon_threads--; | |
3497 daemon = false; | |
3498 | |
3499 // Only one thread left, do a notify on the Threads_lock so a thread waiting | |
3500 // on destroy_vm will wake up. | |
3501 if (number_of_non_daemon_threads() == 1) | |
3502 Threads_lock->notify_all(); | |
3503 } | |
3504 ThreadService::remove_thread(p, daemon); | |
3505 | |
3506 // Make sure that safepoint code disregard this thread. This is needed since | |
3507 // the thread might mess around with locks after this point. This can cause it | |
3508 // to do callbacks into the safepoint code. However, the safepoint code is not aware | |
3509 // of this thread since it is removed from the queue. | |
3510 p->set_terminated_value(); | |
3511 } // unlock Threads_lock | |
3512 | |
3513 // Since Events::log uses a lock, we grab it outside the Threads_lock | |
3514 Events::log("Thread exited: " INTPTR_FORMAT, p); | |
3515 } | |
3516 | |
3517 // Threads_lock must be held when this is called (or must be called during a safepoint) | |
3518 bool Threads::includes(JavaThread* p) { | |
3519 assert(Threads_lock->is_locked(), "sanity check"); | |
3520 ALL_JAVA_THREADS(q) { | |
3521 if (q == p ) { | |
3522 return true; | |
3523 } | |
3524 } | |
3525 return false; | |
3526 } | |
3527 | |
3528 // Operations on the Threads list for GC. These are not explicitly locked, | |
3529 // but the garbage collector must provide a safe context for them to run. | |
3530 // In particular, these things should never be called when the Threads_lock | |
3531 // is held by some other thread. (Note: the Safepoint abstraction also | |
3532 // uses the Threads_lock to gurantee this property. It also makes sure that | |
3533 // all threads gets blocked when exiting or starting). | |
3534 | |
3535 void Threads::oops_do(OopClosure* f) { | |
3536 ALL_JAVA_THREADS(p) { | |
3537 p->oops_do(f); | |
3538 } | |
3539 VMThread::vm_thread()->oops_do(f); | |
3540 } | |
3541 | |
3542 void Threads::possibly_parallel_oops_do(OopClosure* f) { | |
3543 // Introduce a mechanism allowing parallel threads to claim threads as | |
3544 // root groups. Overhead should be small enough to use all the time, | |
3545 // even in sequential code. | |
3546 SharedHeap* sh = SharedHeap::heap(); | |
3547 bool is_par = (sh->n_par_threads() > 0); | |
3548 int cp = SharedHeap::heap()->strong_roots_parity(); | |
3549 ALL_JAVA_THREADS(p) { | |
3550 if (p->claim_oops_do(is_par, cp)) { | |
3551 p->oops_do(f); | |
3552 } | |
3553 } | |
3554 VMThread* vmt = VMThread::vm_thread(); | |
3555 if (vmt->claim_oops_do(is_par, cp)) | |
3556 vmt->oops_do(f); | |
3557 } | |
3558 | |
3559 #ifndef SERIALGC | |
3560 // Used by ParallelScavenge | |
3561 void Threads::create_thread_roots_tasks(GCTaskQueue* q) { | |
3562 ALL_JAVA_THREADS(p) { | |
3563 q->enqueue(new ThreadRootsTask(p)); | |
3564 } | |
3565 q->enqueue(new ThreadRootsTask(VMThread::vm_thread())); | |
3566 } | |
3567 | |
3568 // Used by Parallel Old | |
3569 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) { | |
3570 ALL_JAVA_THREADS(p) { | |
3571 q->enqueue(new ThreadRootsMarkingTask(p)); | |
3572 } | |
3573 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread())); | |
3574 } | |
3575 #endif // SERIALGC | |
3576 | |
3577 void Threads::nmethods_do() { | |
3578 ALL_JAVA_THREADS(p) { | |
3579 p->nmethods_do(); | |
3580 } | |
3581 VMThread::vm_thread()->nmethods_do(); | |
3582 } | |
3583 | |
3584 void Threads::gc_epilogue() { | |
3585 ALL_JAVA_THREADS(p) { | |
3586 p->gc_epilogue(); | |
3587 } | |
3588 } | |
3589 | |
3590 void Threads::gc_prologue() { | |
3591 ALL_JAVA_THREADS(p) { | |
3592 p->gc_prologue(); | |
3593 } | |
3594 } | |
3595 | |
3596 void Threads::deoptimized_wrt_marked_nmethods() { | |
3597 ALL_JAVA_THREADS(p) { | |
3598 p->deoptimized_wrt_marked_nmethods(); | |
3599 } | |
3600 } | |
3601 | |
3602 | |
3603 // Get count Java threads that are waiting to enter the specified monitor. | |
3604 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count, | |
3605 address monitor, bool doLock) { | |
3606 assert(doLock || SafepointSynchronize::is_at_safepoint(), | |
3607 "must grab Threads_lock or be at safepoint"); | |
3608 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count); | |
3609 | |
3610 int i = 0; | |
3611 { | |
3612 MutexLockerEx ml(doLock ? Threads_lock : NULL); | |
3613 ALL_JAVA_THREADS(p) { | |
3614 if (p->is_Compiler_thread()) continue; | |
3615 | |
3616 address pending = (address)p->current_pending_monitor(); | |
3617 if (pending == monitor) { // found a match | |
3618 if (i < count) result->append(p); // save the first count matches | |
3619 i++; | |
3620 } | |
3621 } | |
3622 } | |
3623 return result; | |
3624 } | |
3625 | |
3626 | |
3627 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) { | |
3628 assert(doLock || | |
3629 Threads_lock->owned_by_self() || | |
3630 SafepointSynchronize::is_at_safepoint(), | |
3631 "must grab Threads_lock or be at safepoint"); | |
3632 | |
3633 // NULL owner means not locked so we can skip the search | |
3634 if (owner == NULL) return NULL; | |
3635 | |
3636 { | |
3637 MutexLockerEx ml(doLock ? Threads_lock : NULL); | |
3638 ALL_JAVA_THREADS(p) { | |
3639 // first, see if owner is the address of a Java thread | |
3640 if (owner == (address)p) return p; | |
3641 } | |
3642 } | |
3643 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled"); | |
3644 if (UseHeavyMonitors) return NULL; | |
3645 | |
3646 // | |
3647 // If we didn't find a matching Java thread and we didn't force use of | |
3648 // heavyweight monitors, then the owner is the stack address of the | |
3649 // Lock Word in the owning Java thread's stack. | |
3650 // | |
3651 // We can't use Thread::is_lock_owned() or Thread::lock_is_in_stack() because | |
3652 // those routines rely on the "current" stack pointer. That would be our | |
3653 // stack pointer which is not relevant to the question. Instead we use the | |
3654 // highest lock ever entered by the thread and find the thread that is | |
3655 // higher than and closest to our target stack address. | |
3656 // | |
3657 address least_diff = 0; | |
3658 bool least_diff_initialized = false; | |
3659 JavaThread* the_owner = NULL; | |
3660 { | |
3661 MutexLockerEx ml(doLock ? Threads_lock : NULL); | |
3662 ALL_JAVA_THREADS(q) { | |
3663 address addr = q->highest_lock(); | |
3664 if (addr == NULL || addr < owner) continue; // thread has entered no monitors or is too low | |
3665 address diff = (address)(addr - owner); | |
3666 if (!least_diff_initialized || diff < least_diff) { | |
3667 least_diff_initialized = true; | |
3668 least_diff = diff; | |
3669 the_owner = q; | |
3670 } | |
3671 } | |
3672 } | |
3673 assert(the_owner != NULL, "Did not find owning Java thread for lock word address"); | |
3674 return the_owner; | |
3675 } | |
3676 | |
3677 // Threads::print_on() is called at safepoint by VM_PrintThreads operation. | |
3678 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) { | |
3679 char buf[32]; | |
3680 st->print_cr(os::local_time_string(buf, sizeof(buf))); | |
3681 | |
3682 st->print_cr("Full thread dump %s (%s %s):", | |
3683 Abstract_VM_Version::vm_name(), | |
3684 Abstract_VM_Version::vm_release(), | |
3685 Abstract_VM_Version::vm_info_string() | |
3686 ); | |
3687 st->cr(); | |
3688 | |
3689 #ifndef SERIALGC | |
3690 // Dump concurrent locks | |
3691 ConcurrentLocksDump concurrent_locks; | |
3692 if (print_concurrent_locks) { | |
3693 concurrent_locks.dump_at_safepoint(); | |
3694 } | |
3695 #endif // SERIALGC | |
3696 | |
3697 ALL_JAVA_THREADS(p) { | |
3698 ResourceMark rm; | |
3699 p->print_on(st); | |
3700 if (print_stacks) { | |
3701 if (internal_format) { | |
3702 p->trace_stack(); | |
3703 } else { | |
3704 p->print_stack_on(st); | |
3705 } | |
3706 } | |
3707 st->cr(); | |
3708 #ifndef SERIALGC | |
3709 if (print_concurrent_locks) { | |
3710 concurrent_locks.print_locks_on(p, st); | |
3711 } | |
3712 #endif // SERIALGC | |
3713 } | |
3714 | |
3715 VMThread::vm_thread()->print_on(st); | |
3716 st->cr(); | |
3717 Universe::heap()->print_gc_threads_on(st); | |
3718 WatcherThread* wt = WatcherThread::watcher_thread(); | |
3719 if (wt != NULL) wt->print_on(st); | |
3720 st->cr(); | |
3721 CompileBroker::print_compiler_threads_on(st); | |
3722 st->flush(); | |
3723 } | |
3724 | |
3725 // Threads::print_on_error() is called by fatal error handler. It's possible | |
3726 // that VM is not at safepoint and/or current thread is inside signal handler. | |
3727 // Don't print stack trace, as the stack may not be walkable. Don't allocate | |
3728 // memory (even in resource area), it might deadlock the error handler. | |
3729 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) { | |
3730 bool found_current = false; | |
3731 st->print_cr("Java Threads: ( => current thread )"); | |
3732 ALL_JAVA_THREADS(thread) { | |
3733 bool is_current = (current == thread); | |
3734 found_current = found_current || is_current; | |
3735 | |
3736 st->print("%s", is_current ? "=>" : " "); | |
3737 | |
3738 st->print(PTR_FORMAT, thread); | |
3739 st->print(" "); | |
3740 thread->print_on_error(st, buf, buflen); | |
3741 st->cr(); | |
3742 } | |
3743 st->cr(); | |
3744 | |
3745 st->print_cr("Other Threads:"); | |
3746 if (VMThread::vm_thread()) { | |
3747 bool is_current = (current == VMThread::vm_thread()); | |
3748 found_current = found_current || is_current; | |
3749 st->print("%s", current == VMThread::vm_thread() ? "=>" : " "); | |
3750 | |
3751 st->print(PTR_FORMAT, VMThread::vm_thread()); | |
3752 st->print(" "); | |
3753 VMThread::vm_thread()->print_on_error(st, buf, buflen); | |
3754 st->cr(); | |
3755 } | |
3756 WatcherThread* wt = WatcherThread::watcher_thread(); | |
3757 if (wt != NULL) { | |
3758 bool is_current = (current == wt); | |
3759 found_current = found_current || is_current; | |
3760 st->print("%s", is_current ? "=>" : " "); | |
3761 | |
3762 st->print(PTR_FORMAT, wt); | |
3763 st->print(" "); | |
3764 wt->print_on_error(st, buf, buflen); | |
3765 st->cr(); | |
3766 } | |
3767 if (!found_current) { | |
3768 st->cr(); | |
3769 st->print("=>" PTR_FORMAT " (exited) ", current); | |
3770 current->print_on_error(st, buf, buflen); | |
3771 st->cr(); | |
3772 } | |
3773 } | |
3774 | |
3775 | |
3776 // Lifecycle management for TSM ParkEvents. | |
3777 // ParkEvents are type-stable (TSM). | |
3778 // In our particular implementation they happen to be immortal. | |
3779 // | |
3780 // We manage concurrency on the FreeList with a CAS-based | |
3781 // detach-modify-reattach idiom that avoids the ABA problems | |
3782 // that would otherwise be present in a simple CAS-based | |
3783 // push-pop implementation. (push-one and pop-all) | |
3784 // | |
3785 // Caveat: Allocate() and Release() may be called from threads | |
3786 // other than the thread associated with the Event! | |
3787 // If we need to call Allocate() when running as the thread in | |
3788 // question then look for the PD calls to initialize native TLS. | |
3789 // Native TLS (Win32/Linux/Solaris) can only be initialized or | |
3790 // accessed by the associated thread. | |
3791 // See also pd_initialize(). | |
3792 // | |
3793 // Note that we could defer associating a ParkEvent with a thread | |
3794 // until the 1st time the thread calls park(). unpark() calls to | |
3795 // an unprovisioned thread would be ignored. The first park() call | |
3796 // for a thread would allocate and associate a ParkEvent and return | |
3797 // immediately. | |
3798 | |
3799 volatile int ParkEvent::ListLock = 0 ; | |
3800 ParkEvent * volatile ParkEvent::FreeList = NULL ; | |
3801 | |
3802 ParkEvent * ParkEvent::Allocate (Thread * t) { | |
3803 // In rare cases -- JVM_RawMonitor* operations -- we can find t == null. | |
3804 ParkEvent * ev ; | |
3805 | |
3806 // Start by trying to recycle an existing but unassociated | |
3807 // ParkEvent from the global free list. | |
3808 for (;;) { | |
3809 ev = FreeList ; | |
3810 if (ev == NULL) break ; | |
3811 // 1: Detach - sequester or privatize the list | |
3812 // Tantamount to ev = Swap (&FreeList, NULL) | |
3813 if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) { | |
3814 continue ; | |
3815 } | |
3816 | |
3817 // We've detached the list. The list in-hand is now | |
3818 // local to this thread. This thread can operate on the | |
3819 // list without risk of interference from other threads. | |
3820 // 2: Extract -- pop the 1st element from the list. | |
3821 ParkEvent * List = ev->FreeNext ; | |
3822 if (List == NULL) break ; | |
3823 for (;;) { | |
3824 // 3: Try to reattach the residual list | |
3825 guarantee (List != NULL, "invariant") ; | |
3826 ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ; | |
3827 if (Arv == NULL) break ; | |
3828 | |
3829 // New nodes arrived. Try to detach the recent arrivals. | |
3830 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) { | |
3831 continue ; | |
3832 } | |
3833 guarantee (Arv != NULL, "invariant") ; | |
3834 // 4: Merge Arv into List | |
3835 ParkEvent * Tail = List ; | |
3836 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ; | |
3837 Tail->FreeNext = Arv ; | |
3838 } | |
3839 break ; | |
3840 } | |
3841 | |
3842 if (ev != NULL) { | |
3843 guarantee (ev->AssociatedWith == NULL, "invariant") ; | |
3844 } else { | |
3845 // Do this the hard way -- materialize a new ParkEvent. | |
3846 // In rare cases an allocating thread might detach a long list -- | |
3847 // installing null into FreeList -- and then stall or be obstructed. | |
3848 // A 2nd thread calling Allocate() would see FreeList == null. | |
3849 // The list held privately by the 1st thread is unavailable to the 2nd thread. | |
3850 // In that case the 2nd thread would have to materialize a new ParkEvent, | |
3851 // even though free ParkEvents existed in the system. In this case we end up | |
3852 // with more ParkEvents in circulation than we need, but the race is | |
3853 // rare and the outcome is benign. Ideally, the # of extant ParkEvents | |
3854 // is equal to the maximum # of threads that existed at any one time. | |
3855 // Because of the race mentioned above, segments of the freelist | |
3856 // can be transiently inaccessible. At worst we may end up with the | |
3857 // # of ParkEvents in circulation slightly above the ideal. | |
3858 // Note that if we didn't have the TSM/immortal constraint, then | |
3859 // when reattaching, above, we could trim the list. | |
3860 ev = new ParkEvent () ; | |
3861 guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ; | |
3862 } | |
3863 ev->reset() ; // courtesy to caller | |
3864 ev->AssociatedWith = t ; // Associate ev with t | |
3865 ev->FreeNext = NULL ; | |
3866 return ev ; | |
3867 } | |
3868 | |
3869 void ParkEvent::Release (ParkEvent * ev) { | |
3870 if (ev == NULL) return ; | |
3871 guarantee (ev->FreeNext == NULL , "invariant") ; | |
3872 ev->AssociatedWith = NULL ; | |
3873 for (;;) { | |
3874 // Push ev onto FreeList | |
3875 // The mechanism is "half" lock-free. | |
3876 ParkEvent * List = FreeList ; | |
3877 ev->FreeNext = List ; | |
3878 if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ; | |
3879 } | |
3880 } | |
3881 | |
3882 // Override operator new and delete so we can ensure that the | |
3883 // least significant byte of ParkEvent addresses is 0. | |
3884 // Beware that excessive address alignment is undesirable | |
3885 // as it can result in D$ index usage imbalance as | |
3886 // well as bank access imbalance on Niagara-like platforms, | |
3887 // although Niagara's hash function should help. | |
3888 | |
3889 void * ParkEvent::operator new (size_t sz) { | |
3890 return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ; | |
3891 } | |
3892 | |
3893 void ParkEvent::operator delete (void * a) { | |
3894 // ParkEvents are type-stable and immortal ... | |
3895 ShouldNotReachHere(); | |
3896 } | |
3897 | |
3898 | |
3899 // 6399321 As a temporary measure we copied & modified the ParkEvent:: | |
3900 // allocate() and release() code for use by Parkers. The Parker:: forms | |
3901 // will eventually be removed as we consolide and shift over to ParkEvents | |
3902 // for both builtin synchronization and JSR166 operations. | |
3903 | |
3904 volatile int Parker::ListLock = 0 ; | |
3905 Parker * volatile Parker::FreeList = NULL ; | |
3906 | |
3907 Parker * Parker::Allocate (JavaThread * t) { | |
3908 guarantee (t != NULL, "invariant") ; | |
3909 Parker * p ; | |
3910 | |
3911 // Start by trying to recycle an existing but unassociated | |
3912 // Parker from the global free list. | |
3913 for (;;) { | |
3914 p = FreeList ; | |
3915 if (p == NULL) break ; | |
3916 // 1: Detach | |
3917 // Tantamount to p = Swap (&FreeList, NULL) | |
3918 if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) { | |
3919 continue ; | |
3920 } | |
3921 | |
3922 // We've detached the list. The list in-hand is now | |
3923 // local to this thread. This thread can operate on the | |
3924 // list without risk of interference from other threads. | |
3925 // 2: Extract -- pop the 1st element from the list. | |
3926 Parker * List = p->FreeNext ; | |
3927 if (List == NULL) break ; | |
3928 for (;;) { | |
3929 // 3: Try to reattach the residual list | |
3930 guarantee (List != NULL, "invariant") ; | |
3931 Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ; | |
3932 if (Arv == NULL) break ; | |
3933 | |
3934 // New nodes arrived. Try to detach the recent arrivals. | |
3935 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) { | |
3936 continue ; | |
3937 } | |
3938 guarantee (Arv != NULL, "invariant") ; | |
3939 // 4: Merge Arv into List | |
3940 Parker * Tail = List ; | |
3941 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ; | |
3942 Tail->FreeNext = Arv ; | |
3943 } | |
3944 break ; | |
3945 } | |
3946 | |
3947 if (p != NULL) { | |
3948 guarantee (p->AssociatedWith == NULL, "invariant") ; | |
3949 } else { | |
3950 // Do this the hard way -- materialize a new Parker.. | |
3951 // In rare cases an allocating thread might detach | |
3952 // a long list -- installing null into FreeList --and | |
3953 // then stall. Another thread calling Allocate() would see | |
3954 // FreeList == null and then invoke the ctor. In this case we | |
3955 // end up with more Parkers in circulation than we need, but | |
3956 // the race is rare and the outcome is benign. | |
3957 // Ideally, the # of extant Parkers is equal to the | |
3958 // maximum # of threads that existed at any one time. | |
3959 // Because of the race mentioned above, segments of the | |
3960 // freelist can be transiently inaccessible. At worst | |
3961 // we may end up with the # of Parkers in circulation | |
3962 // slightly above the ideal. | |
3963 p = new Parker() ; | |
3964 } | |
3965 p->AssociatedWith = t ; // Associate p with t | |
3966 p->FreeNext = NULL ; | |
3967 return p ; | |
3968 } | |
3969 | |
3970 | |
3971 void Parker::Release (Parker * p) { | |
3972 if (p == NULL) return ; | |
3973 guarantee (p->AssociatedWith != NULL, "invariant") ; | |
3974 guarantee (p->FreeNext == NULL , "invariant") ; | |
3975 p->AssociatedWith = NULL ; | |
3976 for (;;) { | |
3977 // Push p onto FreeList | |
3978 Parker * List = FreeList ; | |
3979 p->FreeNext = List ; | |
3980 if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ; | |
3981 } | |
3982 } | |
3983 | |
3984 void Threads::verify() { | |
3985 ALL_JAVA_THREADS(p) { | |
3986 p->verify(); | |
3987 } | |
3988 VMThread* thread = VMThread::vm_thread(); | |
3989 if (thread != NULL) thread->verify(); | |
3990 } |