thread.cpp revision 1601:126ea7725993
1/* 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25# 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 32HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin); 33HS_DTRACE_PROBE_DECL(hotspot, vm__init__end); 34HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t, 35 intptr_t, intptr_t, bool); 36HS_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 69void* 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 90void 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 104Thread::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 NOT_PRODUCT(_skip_gcalot = false;) 131 CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;) 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 omInUseList = NULL ; 143 omInUseCount = 0 ; 144 145 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true); 146 _suspend_flags = 0; 147 148 // thread-specific hashCode stream generator state - Marsaglia shift-xor form 149 _hashStateX = os::random() ; 150 _hashStateY = 842502087 ; 151 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ; 152 _hashStateW = 273326509 ; 153 154 _OnTrap = 0 ; 155 _schedctl = NULL ; 156 _Stalled = 0 ; 157 _TypeTag = 0x2BAD ; 158 159 // Many of the following fields are effectively final - immutable 160 // Note that nascent threads can't use the Native Monitor-Mutex 161 // construct until the _MutexEvent is initialized ... 162 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents 163 // we might instead use a stack of ParkEvents that we could provision on-demand. 164 // The stack would act as a cache to avoid calls to ParkEvent::Allocate() 165 // and ::Release() 166 _ParkEvent = ParkEvent::Allocate (this) ; 167 _SleepEvent = ParkEvent::Allocate (this) ; 168 _MutexEvent = ParkEvent::Allocate (this) ; 169 _MuxEvent = ParkEvent::Allocate (this) ; 170 171#ifdef CHECK_UNHANDLED_OOPS 172 if (CheckUnhandledOops) { 173 _unhandled_oops = new UnhandledOops(this); 174 } 175#endif // CHECK_UNHANDLED_OOPS 176#ifdef ASSERT 177 if (UseBiasedLocking) { 178 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed"); 179 assert(this == _real_malloc_address || 180 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment), 181 "bug in forced alignment of thread objects"); 182 } 183#endif /* ASSERT */ 184} 185 186void Thread::initialize_thread_local_storage() { 187 // Note: Make sure this method only calls 188 // non-blocking operations. Otherwise, it might not work 189 // with the thread-startup/safepoint interaction. 190 191 // During Java thread startup, safepoint code should allow this 192 // method to complete because it may need to allocate memory to 193 // store information for the new thread. 194 195 // initialize structure dependent on thread local storage 196 ThreadLocalStorage::set_thread(this); 197 198 // set up any platform-specific state. 199 os::initialize_thread(); 200 201} 202 203void Thread::record_stack_base_and_size() { 204 set_stack_base(os::current_stack_base()); 205 set_stack_size(os::current_stack_size()); 206} 207 208 209Thread::~Thread() { 210 // Reclaim the objectmonitors from the omFreeList of the moribund thread. 211 ObjectSynchronizer::omFlush (this) ; 212 213 // deallocate data structures 214 delete resource_area(); 215 // since the handle marks are using the handle area, we have to deallocated the root 216 // handle mark before deallocating the thread's handle area, 217 assert(last_handle_mark() != NULL, "check we have an element"); 218 delete last_handle_mark(); 219 assert(last_handle_mark() == NULL, "check we have reached the end"); 220 221 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads. 222 // We NULL out the fields for good hygiene. 223 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ; 224 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ; 225 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ; 226 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ; 227 228 delete handle_area(); 229 230 // osthread() can be NULL, if creation of thread failed. 231 if (osthread() != NULL) os::free_thread(osthread()); 232 233 delete _SR_lock; 234 235 // clear thread local storage if the Thread is deleting itself 236 if (this == Thread::current()) { 237 ThreadLocalStorage::set_thread(NULL); 238 } else { 239 // In the case where we're not the current thread, invalidate all the 240 // caches in case some code tries to get the current thread or the 241 // thread that was destroyed, and gets stale information. 242 ThreadLocalStorage::invalidate_all(); 243 } 244 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();) 245} 246 247// NOTE: dummy function for assertion purpose. 248void Thread::run() { 249 ShouldNotReachHere(); 250} 251 252#ifdef ASSERT 253// Private method to check for dangling thread pointer 254void check_for_dangling_thread_pointer(Thread *thread) { 255 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(), 256 "possibility of dangling Thread pointer"); 257} 258#endif 259 260 261#ifndef PRODUCT 262// Tracing method for basic thread operations 263void Thread::trace(const char* msg, const Thread* const thread) { 264 if (!TraceThreadEvents) return; 265 ResourceMark rm; 266 ThreadCritical tc; 267 const char *name = "non-Java thread"; 268 int prio = -1; 269 if (thread->is_Java_thread() 270 && !thread->is_Compiler_thread()) { 271 // The Threads_lock must be held to get information about 272 // this thread but may not be in some situations when 273 // tracing thread events. 274 bool release_Threads_lock = false; 275 if (!Threads_lock->owned_by_self()) { 276 Threads_lock->lock(); 277 release_Threads_lock = true; 278 } 279 JavaThread* jt = (JavaThread *)thread; 280 name = (char *)jt->get_thread_name(); 281 oop thread_oop = jt->threadObj(); 282 if (thread_oop != NULL) { 283 prio = java_lang_Thread::priority(thread_oop); 284 } 285 if (release_Threads_lock) { 286 Threads_lock->unlock(); 287 } 288 } 289 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio); 290} 291#endif 292 293 294ThreadPriority Thread::get_priority(const Thread* const thread) { 295 trace("get priority", thread); 296 ThreadPriority priority; 297 // Can return an error! 298 (void)os::get_priority(thread, priority); 299 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found"); 300 return priority; 301} 302 303void Thread::set_priority(Thread* thread, ThreadPriority priority) { 304 trace("set priority", thread); 305 debug_only(check_for_dangling_thread_pointer(thread);) 306 // Can return an error! 307 (void)os::set_priority(thread, priority); 308} 309 310 311void Thread::start(Thread* thread) { 312 trace("start", thread); 313 // Start is different from resume in that its safety is guaranteed by context or 314 // being called from a Java method synchronized on the Thread object. 315 if (!DisableStartThread) { 316 if (thread->is_Java_thread()) { 317 // Initialize the thread state to RUNNABLE before starting this thread. 318 // Can not set it after the thread started because we do not know the 319 // exact thread state at that time. It could be in MONITOR_WAIT or 320 // in SLEEPING or some other state. 321 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(), 322 java_lang_Thread::RUNNABLE); 323 } 324 os::start_thread(thread); 325 } 326} 327 328// Enqueue a VM_Operation to do the job for us - sometime later 329void Thread::send_async_exception(oop java_thread, oop java_throwable) { 330 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable); 331 VMThread::execute(vm_stop); 332} 333 334 335// 336// Check if an external suspend request has completed (or has been 337// cancelled). Returns true if the thread is externally suspended and 338// false otherwise. 339// 340// The bits parameter returns information about the code path through 341// the routine. Useful for debugging: 342// 343// set in is_ext_suspend_completed(): 344// 0x00000001 - routine was entered 345// 0x00000010 - routine return false at end 346// 0x00000100 - thread exited (return false) 347// 0x00000200 - suspend request cancelled (return false) 348// 0x00000400 - thread suspended (return true) 349// 0x00001000 - thread is in a suspend equivalent state (return true) 350// 0x00002000 - thread is native and walkable (return true) 351// 0x00004000 - thread is native_trans and walkable (needed retry) 352// 353// set in wait_for_ext_suspend_completion(): 354// 0x00010000 - routine was entered 355// 0x00020000 - suspend request cancelled before loop (return false) 356// 0x00040000 - thread suspended before loop (return true) 357// 0x00080000 - suspend request cancelled in loop (return false) 358// 0x00100000 - thread suspended in loop (return true) 359// 0x00200000 - suspend not completed during retry loop (return false) 360// 361 362// Helper class for tracing suspend wait debug bits. 363// 364// 0x00000100 indicates that the target thread exited before it could 365// self-suspend which is not a wait failure. 0x00000200, 0x00020000 and 366// 0x00080000 each indicate a cancelled suspend request so they don't 367// count as wait failures either. 368#define DEBUG_FALSE_BITS (0x00000010 | 0x00200000) 369 370class TraceSuspendDebugBits : public StackObj { 371 private: 372 JavaThread * jt; 373 bool is_wait; 374 bool called_by_wait; // meaningful when !is_wait 375 uint32_t * bits; 376 377 public: 378 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait, 379 uint32_t *_bits) { 380 jt = _jt; 381 is_wait = _is_wait; 382 called_by_wait = _called_by_wait; 383 bits = _bits; 384 } 385 386 ~TraceSuspendDebugBits() { 387 if (!is_wait) { 388#if 1 389 // By default, don't trace bits for is_ext_suspend_completed() calls. 390 // That trace is very chatty. 391 return; 392#else 393 if (!called_by_wait) { 394 // If tracing for is_ext_suspend_completed() is enabled, then only 395 // trace calls to it from wait_for_ext_suspend_completion() 396 return; 397 } 398#endif 399 } 400 401 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) { 402 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) { 403 MutexLocker ml(Threads_lock); // needed for get_thread_name() 404 ResourceMark rm; 405 406 tty->print_cr( 407 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)", 408 jt->get_thread_name(), *bits); 409 410 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed"); 411 } 412 } 413 } 414}; 415#undef DEBUG_FALSE_BITS 416 417 418bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) { 419 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits); 420 421 bool did_trans_retry = false; // only do thread_in_native_trans retry once 422 bool do_trans_retry; // flag to force the retry 423 424 *bits |= 0x00000001; 425 426 do { 427 do_trans_retry = false; 428 429 if (is_exiting()) { 430 // Thread is in the process of exiting. This is always checked 431 // first to reduce the risk of dereferencing a freed JavaThread. 432 *bits |= 0x00000100; 433 return false; 434 } 435 436 if (!is_external_suspend()) { 437 // Suspend request is cancelled. This is always checked before 438 // is_ext_suspended() to reduce the risk of a rogue resume 439 // confusing the thread that made the suspend request. 440 *bits |= 0x00000200; 441 return false; 442 } 443 444 if (is_ext_suspended()) { 445 // thread is suspended 446 *bits |= 0x00000400; 447 return true; 448 } 449 450 // Now that we no longer do hard suspends of threads running 451 // native code, the target thread can be changing thread state 452 // while we are in this routine: 453 // 454 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked 455 // 456 // We save a copy of the thread state as observed at this moment 457 // and make our decision about suspend completeness based on the 458 // copy. This closes the race where the thread state is seen as 459 // _thread_in_native_trans in the if-thread_blocked check, but is 460 // seen as _thread_blocked in if-thread_in_native_trans check. 461 JavaThreadState save_state = thread_state(); 462 463 if (save_state == _thread_blocked && is_suspend_equivalent()) { 464 // If the thread's state is _thread_blocked and this blocking 465 // condition is known to be equivalent to a suspend, then we can 466 // consider the thread to be externally suspended. This means that 467 // the code that sets _thread_blocked has been modified to do 468 // self-suspension if the blocking condition releases. We also 469 // used to check for CONDVAR_WAIT here, but that is now covered by 470 // the _thread_blocked with self-suspension check. 471 // 472 // Return true since we wouldn't be here unless there was still an 473 // external suspend request. 474 *bits |= 0x00001000; 475 return true; 476 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) { 477 // Threads running native code will self-suspend on native==>VM/Java 478 // transitions. If its stack is walkable (should always be the case 479 // unless this function is called before the actual java_suspend() 480 // call), then the wait is done. 481 *bits |= 0x00002000; 482 return true; 483 } else if (!called_by_wait && !did_trans_retry && 484 save_state == _thread_in_native_trans && 485 frame_anchor()->walkable()) { 486 // The thread is transitioning from thread_in_native to another 487 // thread state. check_safepoint_and_suspend_for_native_trans() 488 // will force the thread to self-suspend. If it hasn't gotten 489 // there yet we may have caught the thread in-between the native 490 // code check above and the self-suspend. Lucky us. If we were 491 // called by wait_for_ext_suspend_completion(), then it 492 // will be doing the retries so we don't have to. 493 // 494 // Since we use the saved thread state in the if-statement above, 495 // there is a chance that the thread has already transitioned to 496 // _thread_blocked by the time we get here. In that case, we will 497 // make a single unnecessary pass through the logic below. This 498 // doesn't hurt anything since we still do the trans retry. 499 500 *bits |= 0x00004000; 501 502 // Once the thread leaves thread_in_native_trans for another 503 // thread state, we break out of this retry loop. We shouldn't 504 // need this flag to prevent us from getting back here, but 505 // sometimes paranoia is good. 506 did_trans_retry = true; 507 508 // We wait for the thread to transition to a more usable state. 509 for (int i = 1; i <= SuspendRetryCount; i++) { 510 // We used to do an "os::yield_all(i)" call here with the intention 511 // that yielding would increase on each retry. However, the parameter 512 // is ignored on Linux which means the yield didn't scale up. Waiting 513 // on the SR_lock below provides a much more predictable scale up for 514 // the delay. It also provides a simple/direct point to check for any 515 // safepoint requests from the VMThread 516 517 // temporarily drops SR_lock while doing wait with safepoint check 518 // (if we're a JavaThread - the WatcherThread can also call this) 519 // and increase delay with each retry 520 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); 521 522 // check the actual thread state instead of what we saved above 523 if (thread_state() != _thread_in_native_trans) { 524 // the thread has transitioned to another thread state so 525 // try all the checks (except this one) one more time. 526 do_trans_retry = true; 527 break; 528 } 529 } // end retry loop 530 531 532 } 533 } while (do_trans_retry); 534 535 *bits |= 0x00000010; 536 return false; 537} 538 539// 540// Wait for an external suspend request to complete (or be cancelled). 541// Returns true if the thread is externally suspended and false otherwise. 542// 543bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay, 544 uint32_t *bits) { 545 TraceSuspendDebugBits tsdb(this, true /* is_wait */, 546 false /* !called_by_wait */, bits); 547 548 // local flag copies to minimize SR_lock hold time 549 bool is_suspended; 550 bool pending; 551 uint32_t reset_bits; 552 553 // set a marker so is_ext_suspend_completed() knows we are the caller 554 *bits |= 0x00010000; 555 556 // We use reset_bits to reinitialize the bits value at the top of 557 // each retry loop. This allows the caller to make use of any 558 // unused bits for their own marking purposes. 559 reset_bits = *bits; 560 561 { 562 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 563 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, 564 delay, bits); 565 pending = is_external_suspend(); 566 } 567 // must release SR_lock to allow suspension to complete 568 569 if (!pending) { 570 // A cancelled suspend request is the only false return from 571 // is_ext_suspend_completed() that keeps us from entering the 572 // retry loop. 573 *bits |= 0x00020000; 574 return false; 575 } 576 577 if (is_suspended) { 578 *bits |= 0x00040000; 579 return true; 580 } 581 582 for (int i = 1; i <= retries; i++) { 583 *bits = reset_bits; // reinit to only track last retry 584 585 // We used to do an "os::yield_all(i)" call here with the intention 586 // that yielding would increase on each retry. However, the parameter 587 // is ignored on Linux which means the yield didn't scale up. Waiting 588 // on the SR_lock below provides a much more predictable scale up for 589 // the delay. It also provides a simple/direct point to check for any 590 // safepoint requests from the VMThread 591 592 { 593 MutexLocker ml(SR_lock()); 594 // wait with safepoint check (if we're a JavaThread - the WatcherThread 595 // can also call this) and increase delay with each retry 596 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); 597 598 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, 599 delay, bits); 600 601 // It is possible for the external suspend request to be cancelled 602 // (by a resume) before the actual suspend operation is completed. 603 // Refresh our local copy to see if we still need to wait. 604 pending = is_external_suspend(); 605 } 606 607 if (!pending) { 608 // A cancelled suspend request is the only false return from 609 // is_ext_suspend_completed() that keeps us from staying in the 610 // retry loop. 611 *bits |= 0x00080000; 612 return false; 613 } 614 615 if (is_suspended) { 616 *bits |= 0x00100000; 617 return true; 618 } 619 } // end retry loop 620 621 // thread did not suspend after all our retries 622 *bits |= 0x00200000; 623 return false; 624} 625 626#ifndef PRODUCT 627void JavaThread::record_jump(address target, address instr, const char* file, int line) { 628 629 // This should not need to be atomic as the only way for simultaneous 630 // updates is via interrupts. Even then this should be rare or non-existant 631 // and we don't care that much anyway. 632 633 int index = _jmp_ring_index; 634 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1); 635 _jmp_ring[index]._target = (intptr_t) target; 636 _jmp_ring[index]._instruction = (intptr_t) instr; 637 _jmp_ring[index]._file = file; 638 _jmp_ring[index]._line = line; 639} 640#endif /* PRODUCT */ 641 642// Called by flat profiler 643// Callers have already called wait_for_ext_suspend_completion 644// The assertion for that is currently too complex to put here: 645bool JavaThread::profile_last_Java_frame(frame* _fr) { 646 bool gotframe = false; 647 // self suspension saves needed state. 648 if (has_last_Java_frame() && _anchor.walkable()) { 649 *_fr = pd_last_frame(); 650 gotframe = true; 651 } 652 return gotframe; 653} 654 655void Thread::interrupt(Thread* thread) { 656 trace("interrupt", thread); 657 debug_only(check_for_dangling_thread_pointer(thread);) 658 os::interrupt(thread); 659} 660 661bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) { 662 trace("is_interrupted", thread); 663 debug_only(check_for_dangling_thread_pointer(thread);) 664 // Note: If clear_interrupted==false, this simply fetches and 665 // returns the value of the field osthread()->interrupted(). 666 return os::is_interrupted(thread, clear_interrupted); 667} 668 669 670// GC Support 671bool Thread::claim_oops_do_par_case(int strong_roots_parity) { 672 jint thread_parity = _oops_do_parity; 673 if (thread_parity != strong_roots_parity) { 674 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity); 675 if (res == thread_parity) return true; 676 else { 677 guarantee(res == strong_roots_parity, "Or else what?"); 678 assert(SharedHeap::heap()->n_par_threads() > 0, 679 "Should only fail when parallel."); 680 return false; 681 } 682 } 683 assert(SharedHeap::heap()->n_par_threads() > 0, 684 "Should only fail when parallel."); 685 return false; 686} 687 688void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) { 689 active_handles()->oops_do(f); 690 // Do oop for ThreadShadow 691 f->do_oop((oop*)&_pending_exception); 692 handle_area()->oops_do(f); 693} 694 695void Thread::nmethods_do(CodeBlobClosure* cf) { 696 // no nmethods in a generic thread... 697} 698 699void Thread::print_on(outputStream* st) const { 700 // get_priority assumes osthread initialized 701 if (osthread() != NULL) { 702 st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this); 703 osthread()->print_on(st); 704 } 705 debug_only(if (WizardMode) print_owned_locks_on(st);) 706} 707 708// Thread::print_on_error() is called by fatal error handler. Don't use 709// any lock or allocate memory. 710void Thread::print_on_error(outputStream* st, char* buf, int buflen) const { 711 if (is_VM_thread()) st->print("VMThread"); 712 else if (is_Compiler_thread()) st->print("CompilerThread"); 713 else if (is_Java_thread()) st->print("JavaThread"); 714 else if (is_GC_task_thread()) st->print("GCTaskThread"); 715 else if (is_Watcher_thread()) st->print("WatcherThread"); 716 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread"); 717 else st->print("Thread"); 718 719 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]", 720 _stack_base - _stack_size, _stack_base); 721 722 if (osthread()) { 723 st->print(" [id=%d]", osthread()->thread_id()); 724 } 725} 726 727#ifdef ASSERT 728void Thread::print_owned_locks_on(outputStream* st) const { 729 Monitor *cur = _owned_locks; 730 if (cur == NULL) { 731 st->print(" (no locks) "); 732 } else { 733 st->print_cr(" Locks owned:"); 734 while(cur) { 735 cur->print_on(st); 736 cur = cur->next(); 737 } 738 } 739} 740 741static int ref_use_count = 0; 742 743bool Thread::owns_locks_but_compiled_lock() const { 744 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { 745 if (cur != Compile_lock) return true; 746 } 747 return false; 748} 749 750 751#endif 752 753#ifndef PRODUCT 754 755// The flag: potential_vm_operation notifies if this particular safepoint state could potential 756// invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that 757// no threads which allow_vm_block's are held 758void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) { 759 // Check if current thread is allowed to block at a safepoint 760 if (!(_allow_safepoint_count == 0)) 761 fatal("Possible safepoint reached by thread that does not allow it"); 762 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) { 763 fatal("LEAF method calling lock?"); 764 } 765 766#ifdef ASSERT 767 if (potential_vm_operation && is_Java_thread() 768 && !Universe::is_bootstrapping()) { 769 // Make sure we do not hold any locks that the VM thread also uses. 770 // This could potentially lead to deadlocks 771 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { 772 // Threads_lock is special, since the safepoint synchronization will not start before this is 773 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock, 774 // since it is used to transfer control between JavaThreads and the VMThread 775 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first! 776 if ( (cur->allow_vm_block() && 777 cur != Threads_lock && 778 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation 779 cur != VMOperationRequest_lock && 780 cur != VMOperationQueue_lock) || 781 cur->rank() == Mutex::special) { 782 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name()); 783 } 784 } 785 } 786 787 if (GCALotAtAllSafepoints) { 788 // We could enter a safepoint here and thus have a gc 789 InterfaceSupport::check_gc_alot(); 790 } 791#endif 792} 793#endif 794 795bool Thread::is_in_stack(address adr) const { 796 assert(Thread::current() == this, "is_in_stack can only be called from current thread"); 797 address end = os::current_stack_pointer(); 798 if (stack_base() >= adr && adr >= end) return true; 799 800 return false; 801} 802 803 804// We had to move these methods here, because vm threads get into ObjectSynchronizer::enter 805// However, there is a note in JavaThread::is_lock_owned() about the VM threads not being 806// used for compilation in the future. If that change is made, the need for these methods 807// should be revisited, and they should be removed if possible. 808 809bool Thread::is_lock_owned(address adr) const { 810 return (_stack_base >= adr && adr >= (_stack_base - _stack_size)); 811} 812 813bool Thread::set_as_starting_thread() { 814 // NOTE: this must be called inside the main thread. 815 return os::create_main_thread((JavaThread*)this); 816} 817 818static void initialize_class(symbolHandle class_name, TRAPS) { 819 klassOop klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK); 820 instanceKlass::cast(klass)->initialize(CHECK); 821} 822 823 824// Creates the initial ThreadGroup 825static Handle create_initial_thread_group(TRAPS) { 826 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH); 827 instanceKlassHandle klass (THREAD, k); 828 829 Handle system_instance = klass->allocate_instance_handle(CHECK_NH); 830 { 831 JavaValue result(T_VOID); 832 JavaCalls::call_special(&result, 833 system_instance, 834 klass, 835 vmSymbolHandles::object_initializer_name(), 836 vmSymbolHandles::void_method_signature(), 837 CHECK_NH); 838 } 839 Universe::set_system_thread_group(system_instance()); 840 841 Handle main_instance = klass->allocate_instance_handle(CHECK_NH); 842 { 843 JavaValue result(T_VOID); 844 Handle string = java_lang_String::create_from_str("main", CHECK_NH); 845 JavaCalls::call_special(&result, 846 main_instance, 847 klass, 848 vmSymbolHandles::object_initializer_name(), 849 vmSymbolHandles::threadgroup_string_void_signature(), 850 system_instance, 851 string, 852 CHECK_NH); 853 } 854 return main_instance; 855} 856 857// Creates the initial Thread 858static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) { 859 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL); 860 instanceKlassHandle klass (THREAD, k); 861 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL); 862 863 java_lang_Thread::set_thread(thread_oop(), thread); 864 java_lang_Thread::set_priority(thread_oop(), NormPriority); 865 thread->set_threadObj(thread_oop()); 866 867 Handle string = java_lang_String::create_from_str("main", CHECK_NULL); 868 869 JavaValue result(T_VOID); 870 JavaCalls::call_special(&result, thread_oop, 871 klass, 872 vmSymbolHandles::object_initializer_name(), 873 vmSymbolHandles::threadgroup_string_void_signature(), 874 thread_group, 875 string, 876 CHECK_NULL); 877 return thread_oop(); 878} 879 880static void call_initializeSystemClass(TRAPS) { 881 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK); 882 instanceKlassHandle klass (THREAD, k); 883 884 JavaValue result(T_VOID); 885 JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(), 886 vmSymbolHandles::void_method_signature(), CHECK); 887} 888 889#ifdef KERNEL 890static void set_jkernel_boot_classloader_hook(TRAPS) { 891 klassOop k = SystemDictionary::sun_jkernel_DownloadManager_klass(); 892 instanceKlassHandle klass (THREAD, k); 893 894 if (k == NULL) { 895 // sun.jkernel.DownloadManager may not present in the JDK; just return 896 return; 897 } 898 899 JavaValue result(T_VOID); 900 JavaCalls::call_static(&result, klass, vmSymbolHandles::setBootClassLoaderHook_name(), 901 vmSymbolHandles::void_method_signature(), CHECK); 902} 903#endif // KERNEL 904 905static void reset_vm_info_property(TRAPS) { 906 // the vm info string 907 ResourceMark rm(THREAD); 908 const char *vm_info = VM_Version::vm_info_string(); 909 910 // java.lang.System class 911 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK); 912 instanceKlassHandle klass (THREAD, k); 913 914 // setProperty arguments 915 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK); 916 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK); 917 918 // return value 919 JavaValue r(T_OBJECT); 920 921 // public static String setProperty(String key, String value); 922 JavaCalls::call_static(&r, 923 klass, 924 vmSymbolHandles::setProperty_name(), 925 vmSymbolHandles::string_string_string_signature(), 926 key_str, 927 value_str, 928 CHECK); 929} 930 931 932void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) { 933 assert(thread_group.not_null(), "thread group should be specified"); 934 assert(threadObj() == NULL, "should only create Java thread object once"); 935 936 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK); 937 instanceKlassHandle klass (THREAD, k); 938 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); 939 940 java_lang_Thread::set_thread(thread_oop(), this); 941 java_lang_Thread::set_priority(thread_oop(), NormPriority); 942 set_threadObj(thread_oop()); 943 944 JavaValue result(T_VOID); 945 if (thread_name != NULL) { 946 Handle name = java_lang_String::create_from_str(thread_name, CHECK); 947 // Thread gets assigned specified name and null target 948 JavaCalls::call_special(&result, 949 thread_oop, 950 klass, 951 vmSymbolHandles::object_initializer_name(), 952 vmSymbolHandles::threadgroup_string_void_signature(), 953 thread_group, // Argument 1 954 name, // Argument 2 955 THREAD); 956 } else { 957 // Thread gets assigned name "Thread-nnn" and null target 958 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) 959 JavaCalls::call_special(&result, 960 thread_oop, 961 klass, 962 vmSymbolHandles::object_initializer_name(), 963 vmSymbolHandles::threadgroup_runnable_void_signature(), 964 thread_group, // Argument 1 965 Handle(), // Argument 2 966 THREAD); 967 } 968 969 970 if (daemon) { 971 java_lang_Thread::set_daemon(thread_oop()); 972 } 973 974 if (HAS_PENDING_EXCEPTION) { 975 return; 976 } 977 978 KlassHandle group(this, SystemDictionary::ThreadGroup_klass()); 979 Handle threadObj(this, this->threadObj()); 980 981 JavaCalls::call_special(&result, 982 thread_group, 983 group, 984 vmSymbolHandles::add_method_name(), 985 vmSymbolHandles::thread_void_signature(), 986 threadObj, // Arg 1 987 THREAD); 988 989 990} 991 992// NamedThread -- non-JavaThread subclasses with multiple 993// uniquely named instances should derive from this. 994NamedThread::NamedThread() : Thread() { 995 _name = NULL; 996 _processed_thread = NULL; 997} 998 999NamedThread::~NamedThread() { 1000 if (_name != NULL) { 1001 FREE_C_HEAP_ARRAY(char, _name); 1002 _name = NULL; 1003 } 1004} 1005 1006void NamedThread::set_name(const char* format, ...) { 1007 guarantee(_name == NULL, "Only get to set name once."); 1008 _name = NEW_C_HEAP_ARRAY(char, max_name_len); 1009 guarantee(_name != NULL, "alloc failure"); 1010 va_list ap; 1011 va_start(ap, format); 1012 jio_vsnprintf(_name, max_name_len, format, ap); 1013 va_end(ap); 1014} 1015 1016// ======= WatcherThread ======== 1017 1018// The watcher thread exists to simulate timer interrupts. It should 1019// be replaced by an abstraction over whatever native support for 1020// timer interrupts exists on the platform. 1021 1022WatcherThread* WatcherThread::_watcher_thread = NULL; 1023volatile bool WatcherThread::_should_terminate = false; 1024 1025WatcherThread::WatcherThread() : Thread() { 1026 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread"); 1027 if (os::create_thread(this, os::watcher_thread)) { 1028 _watcher_thread = this; 1029 1030 // Set the watcher thread to the highest OS priority which should not be 1031 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY 1032 // is created. The only normal thread using this priority is the reference 1033 // handler thread, which runs for very short intervals only. 1034 // If the VMThread's priority is not lower than the WatcherThread profiling 1035 // will be inaccurate. 1036 os::set_priority(this, MaxPriority); 1037 if (!DisableStartThread) { 1038 os::start_thread(this); 1039 } 1040 } 1041} 1042 1043void WatcherThread::run() { 1044 assert(this == watcher_thread(), "just checking"); 1045 1046 this->record_stack_base_and_size(); 1047 this->initialize_thread_local_storage(); 1048 this->set_active_handles(JNIHandleBlock::allocate_block()); 1049 while(!_should_terminate) { 1050 assert(watcher_thread() == Thread::current(), "thread consistency check"); 1051 assert(watcher_thread() == this, "thread consistency check"); 1052 1053 // Calculate how long it'll be until the next PeriodicTask work 1054 // should be done, and sleep that amount of time. 1055 size_t time_to_wait = PeriodicTask::time_to_wait(); 1056 1057 // we expect this to timeout - we only ever get unparked when 1058 // we should terminate 1059 { 1060 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */); 1061 1062 jlong prev_time = os::javaTimeNanos(); 1063 for (;;) { 1064 int res= _SleepEvent->park(time_to_wait); 1065 if (res == OS_TIMEOUT || _should_terminate) 1066 break; 1067 // spurious wakeup of some kind 1068 jlong now = os::javaTimeNanos(); 1069 time_to_wait -= (now - prev_time) / 1000000; 1070 if (time_to_wait <= 0) 1071 break; 1072 prev_time = now; 1073 } 1074 } 1075 1076 if (is_error_reported()) { 1077 // A fatal error has happened, the error handler(VMError::report_and_die) 1078 // should abort JVM after creating an error log file. However in some 1079 // rare cases, the error handler itself might deadlock. Here we try to 1080 // kill JVM if the fatal error handler fails to abort in 2 minutes. 1081 // 1082 // This code is in WatcherThread because WatcherThread wakes up 1083 // periodically so the fatal error handler doesn't need to do anything; 1084 // also because the WatcherThread is less likely to crash than other 1085 // threads. 1086 1087 for (;;) { 1088 if (!ShowMessageBoxOnError 1089 && (OnError == NULL || OnError[0] == '\0') 1090 && Arguments::abort_hook() == NULL) { 1091 os::sleep(this, 2 * 60 * 1000, false); 1092 fdStream err(defaultStream::output_fd()); 1093 err.print_raw_cr("# [ timer expired, abort... ]"); 1094 // skip atexit/vm_exit/vm_abort hooks 1095 os::die(); 1096 } 1097 1098 // Wake up 5 seconds later, the fatal handler may reset OnError or 1099 // ShowMessageBoxOnError when it is ready to abort. 1100 os::sleep(this, 5 * 1000, false); 1101 } 1102 } 1103 1104 PeriodicTask::real_time_tick(time_to_wait); 1105 1106 // If we have no more tasks left due to dynamic disenrollment, 1107 // shut down the thread since we don't currently support dynamic enrollment 1108 if (PeriodicTask::num_tasks() == 0) { 1109 _should_terminate = true; 1110 } 1111 } 1112 1113 // Signal that it is terminated 1114 { 1115 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag); 1116 _watcher_thread = NULL; 1117 Terminator_lock->notify(); 1118 } 1119 1120 // Thread destructor usually does this.. 1121 ThreadLocalStorage::set_thread(NULL); 1122} 1123 1124void WatcherThread::start() { 1125 if (watcher_thread() == NULL) { 1126 _should_terminate = false; 1127 // Create the single instance of WatcherThread 1128 new WatcherThread(); 1129 } 1130} 1131 1132void WatcherThread::stop() { 1133 // it is ok to take late safepoints here, if needed 1134 MutexLocker mu(Terminator_lock); 1135 _should_terminate = true; 1136 OrderAccess::fence(); // ensure WatcherThread sees update in main loop 1137 1138 Thread* watcher = watcher_thread(); 1139 if (watcher != NULL) 1140 watcher->_SleepEvent->unpark(); 1141 1142 while(watcher_thread() != NULL) { 1143 // This wait should make safepoint checks, wait without a timeout, 1144 // and wait as a suspend-equivalent condition. 1145 // 1146 // Note: If the FlatProfiler is running, then this thread is waiting 1147 // for the WatcherThread to terminate and the WatcherThread, via the 1148 // FlatProfiler task, is waiting for the external suspend request on 1149 // this thread to complete. wait_for_ext_suspend_completion() will 1150 // eventually timeout, but that takes time. Making this wait a 1151 // suspend-equivalent condition solves that timeout problem. 1152 // 1153 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0, 1154 Mutex::_as_suspend_equivalent_flag); 1155 } 1156} 1157 1158void WatcherThread::print_on(outputStream* st) const { 1159 st->print("\"%s\" ", name()); 1160 Thread::print_on(st); 1161 st->cr(); 1162} 1163 1164// ======= JavaThread ======== 1165 1166// A JavaThread is a normal Java thread 1167 1168void JavaThread::initialize() { 1169 // Initialize fields 1170 1171 // Set the claimed par_id to -1 (ie not claiming any par_ids) 1172 set_claimed_par_id(-1); 1173 1174 set_saved_exception_pc(NULL); 1175 set_threadObj(NULL); 1176 _anchor.clear(); 1177 set_entry_point(NULL); 1178 set_jni_functions(jni_functions()); 1179 set_callee_target(NULL); 1180 set_vm_result(NULL); 1181 set_vm_result_2(NULL); 1182 set_vframe_array_head(NULL); 1183 set_vframe_array_last(NULL); 1184 set_deferred_locals(NULL); 1185 set_deopt_mark(NULL); 1186 clear_must_deopt_id(); 1187 set_monitor_chunks(NULL); 1188 set_next(NULL); 1189 set_thread_state(_thread_new); 1190 _terminated = _not_terminated; 1191 _privileged_stack_top = NULL; 1192 _array_for_gc = NULL; 1193 _suspend_equivalent = false; 1194 _in_deopt_handler = 0; 1195 _doing_unsafe_access = false; 1196 _stack_guard_state = stack_guard_unused; 1197 _exception_oop = NULL; 1198 _exception_pc = 0; 1199 _exception_handler_pc = 0; 1200 _exception_stack_size = 0; 1201 _jvmti_thread_state= NULL; 1202 _should_post_on_exceptions_flag = JNI_FALSE; 1203 _jvmti_get_loaded_classes_closure = NULL; 1204 _interp_only_mode = 0; 1205 _special_runtime_exit_condition = _no_async_condition; 1206 _pending_async_exception = NULL; 1207 _is_compiling = false; 1208 _thread_stat = NULL; 1209 _thread_stat = new ThreadStatistics(); 1210 _blocked_on_compilation = false; 1211 _jni_active_critical = 0; 1212 _do_not_unlock_if_synchronized = false; 1213 _cached_monitor_info = NULL; 1214 _parker = Parker::Allocate(this) ; 1215 1216#ifndef PRODUCT 1217 _jmp_ring_index = 0; 1218 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) { 1219 record_jump(NULL, NULL, NULL, 0); 1220 } 1221#endif /* PRODUCT */ 1222 1223 set_thread_profiler(NULL); 1224 if (FlatProfiler::is_active()) { 1225 // This is where we would decide to either give each thread it's own profiler 1226 // or use one global one from FlatProfiler, 1227 // or up to some count of the number of profiled threads, etc. 1228 ThreadProfiler* pp = new ThreadProfiler(); 1229 pp->engage(); 1230 set_thread_profiler(pp); 1231 } 1232 1233 // Setup safepoint state info for this thread 1234 ThreadSafepointState::create(this); 1235 1236 debug_only(_java_call_counter = 0); 1237 1238 // JVMTI PopFrame support 1239 _popframe_condition = popframe_inactive; 1240 _popframe_preserved_args = NULL; 1241 _popframe_preserved_args_size = 0; 1242 1243 pd_initialize(); 1244} 1245 1246#ifndef SERIALGC 1247SATBMarkQueueSet JavaThread::_satb_mark_queue_set; 1248DirtyCardQueueSet JavaThread::_dirty_card_queue_set; 1249#endif // !SERIALGC 1250 1251JavaThread::JavaThread(bool is_attaching) : 1252 Thread() 1253#ifndef SERIALGC 1254 , _satb_mark_queue(&_satb_mark_queue_set), 1255 _dirty_card_queue(&_dirty_card_queue_set) 1256#endif // !SERIALGC 1257{ 1258 initialize(); 1259 _is_attaching = is_attaching; 1260 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor"); 1261} 1262 1263bool JavaThread::reguard_stack(address cur_sp) { 1264 if (_stack_guard_state != stack_guard_yellow_disabled) { 1265 return true; // Stack already guarded or guard pages not needed. 1266 } 1267 1268 if (register_stack_overflow()) { 1269 // For those architectures which have separate register and 1270 // memory stacks, we must check the register stack to see if 1271 // it has overflowed. 1272 return false; 1273 } 1274 1275 // Java code never executes within the yellow zone: the latter is only 1276 // there to provoke an exception during stack banging. If java code 1277 // is executing there, either StackShadowPages should be larger, or 1278 // some exception code in c1, c2 or the interpreter isn't unwinding 1279 // when it should. 1280 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages"); 1281 1282 enable_stack_yellow_zone(); 1283 return true; 1284} 1285 1286bool JavaThread::reguard_stack(void) { 1287 return reguard_stack(os::current_stack_pointer()); 1288} 1289 1290 1291void JavaThread::block_if_vm_exited() { 1292 if (_terminated == _vm_exited) { 1293 // _vm_exited is set at safepoint, and Threads_lock is never released 1294 // we will block here forever 1295 Threads_lock->lock_without_safepoint_check(); 1296 ShouldNotReachHere(); 1297 } 1298} 1299 1300 1301// Remove this ifdef when C1 is ported to the compiler interface. 1302static void compiler_thread_entry(JavaThread* thread, TRAPS); 1303 1304JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : 1305 Thread() 1306#ifndef SERIALGC 1307 , _satb_mark_queue(&_satb_mark_queue_set), 1308 _dirty_card_queue(&_dirty_card_queue_set) 1309#endif // !SERIALGC 1310{ 1311 if (TraceThreadEvents) { 1312 tty->print_cr("creating thread %p", this); 1313 } 1314 initialize(); 1315 _is_attaching = false; 1316 set_entry_point(entry_point); 1317 // Create the native thread itself. 1318 // %note runtime_23 1319 os::ThreadType thr_type = os::java_thread; 1320 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread : 1321 os::java_thread; 1322 os::create_thread(this, thr_type, stack_sz); 1323 1324 // The _osthread may be NULL here because we ran out of memory (too many threads active). 1325 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller 1326 // may hold a lock and all locks must be unlocked before throwing the exception (throwing 1327 // the exception consists of creating the exception object & initializing it, initialization 1328 // will leave the VM via a JavaCall and then all locks must be unlocked). 1329 // 1330 // The thread is still suspended when we reach here. Thread must be explicit started 1331 // by creator! Furthermore, the thread must also explicitly be added to the Threads list 1332 // by calling Threads:add. The reason why this is not done here, is because the thread 1333 // object must be fully initialized (take a look at JVM_Start) 1334} 1335 1336JavaThread::~JavaThread() { 1337 if (TraceThreadEvents) { 1338 tty->print_cr("terminate thread %p", this); 1339 } 1340 1341 // JSR166 -- return the parker to the free list 1342 Parker::Release(_parker); 1343 _parker = NULL ; 1344 1345 // Free any remaining previous UnrollBlock 1346 vframeArray* old_array = vframe_array_last(); 1347 1348 if (old_array != NULL) { 1349 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); 1350 old_array->set_unroll_block(NULL); 1351 delete old_info; 1352 delete old_array; 1353 } 1354 1355 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals(); 1356 if (deferred != NULL) { 1357 // This can only happen if thread is destroyed before deoptimization occurs. 1358 assert(deferred->length() != 0, "empty array!"); 1359 do { 1360 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0); 1361 deferred->remove_at(0); 1362 // individual jvmtiDeferredLocalVariableSet are CHeapObj's 1363 delete dlv; 1364 } while (deferred->length() != 0); 1365 delete deferred; 1366 } 1367 1368 // All Java related clean up happens in exit 1369 ThreadSafepointState::destroy(this); 1370 if (_thread_profiler != NULL) delete _thread_profiler; 1371 if (_thread_stat != NULL) delete _thread_stat; 1372} 1373 1374 1375// The first routine called by a new Java thread 1376void JavaThread::run() { 1377 // initialize thread-local alloc buffer related fields 1378 this->initialize_tlab(); 1379 1380 // used to test validitity of stack trace backs 1381 this->record_base_of_stack_pointer(); 1382 1383 // Record real stack base and size. 1384 this->record_stack_base_and_size(); 1385 1386 // Initialize thread local storage; set before calling MutexLocker 1387 this->initialize_thread_local_storage(); 1388 1389 this->create_stack_guard_pages(); 1390 1391 this->cache_global_variables(); 1392 1393 // Thread is now sufficient initialized to be handled by the safepoint code as being 1394 // in the VM. Change thread state from _thread_new to _thread_in_vm 1395 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm); 1396 1397 assert(JavaThread::current() == this, "sanity check"); 1398 assert(!Thread::current()->owns_locks(), "sanity check"); 1399 1400 DTRACE_THREAD_PROBE(start, this); 1401 1402 // This operation might block. We call that after all safepoint checks for a new thread has 1403 // been completed. 1404 this->set_active_handles(JNIHandleBlock::allocate_block()); 1405 1406 if (JvmtiExport::should_post_thread_life()) { 1407 JvmtiExport::post_thread_start(this); 1408 } 1409 1410 // We call another function to do the rest so we are sure that the stack addresses used 1411 // from there will be lower than the stack base just computed 1412 thread_main_inner(); 1413 1414 // Note, thread is no longer valid at this point! 1415} 1416 1417 1418void JavaThread::thread_main_inner() { 1419 assert(JavaThread::current() == this, "sanity check"); 1420 assert(this->threadObj() != NULL, "just checking"); 1421 1422 // Execute thread entry point. If this thread is being asked to restart, 1423 // or has been stopped before starting, do not reexecute entry point. 1424 // Note: Due to JVM_StopThread we can have pending exceptions already! 1425 if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) { 1426 // enter the thread's entry point only if we have no pending exceptions 1427 HandleMark hm(this); 1428 this->entry_point()(this, this); 1429 } 1430 1431 DTRACE_THREAD_PROBE(stop, this); 1432 1433 this->exit(false); 1434 delete this; 1435} 1436 1437 1438static void ensure_join(JavaThread* thread) { 1439 // We do not need to grap the Threads_lock, since we are operating on ourself. 1440 Handle threadObj(thread, thread->threadObj()); 1441 assert(threadObj.not_null(), "java thread object must exist"); 1442 ObjectLocker lock(threadObj, thread); 1443 // Ignore pending exception (ThreadDeath), since we are exiting anyway 1444 thread->clear_pending_exception(); 1445 // It is of profound importance that we set the stillborn bit and reset the thread object, 1446 // before we do the notify. Since, changing these two variable will make JVM_IsAlive return 1447 // false. So in case another thread is doing a join on this thread , it will detect that the thread 1448 // is dead when it gets notified. 1449 java_lang_Thread::set_stillborn(threadObj()); 1450 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. 1451 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED); 1452 java_lang_Thread::set_thread(threadObj(), NULL); 1453 lock.notify_all(thread); 1454 // Ignore pending exception (ThreadDeath), since we are exiting anyway 1455 thread->clear_pending_exception(); 1456} 1457 1458 1459// For any new cleanup additions, please check to see if they need to be applied to 1460// cleanup_failed_attach_current_thread as well. 1461void JavaThread::exit(bool destroy_vm, ExitType exit_type) { 1462 assert(this == JavaThread::current(), "thread consistency check"); 1463 if (!InitializeJavaLangSystem) return; 1464 1465 HandleMark hm(this); 1466 Handle uncaught_exception(this, this->pending_exception()); 1467 this->clear_pending_exception(); 1468 Handle threadObj(this, this->threadObj()); 1469 assert(threadObj.not_null(), "Java thread object should be created"); 1470 1471 if (get_thread_profiler() != NULL) { 1472 get_thread_profiler()->disengage(); 1473 ResourceMark rm; 1474 get_thread_profiler()->print(get_thread_name()); 1475 } 1476 1477 1478 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place 1479 { 1480 EXCEPTION_MARK; 1481 1482 CLEAR_PENDING_EXCEPTION; 1483 } 1484 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This 1485 // has to be fixed by a runtime query method 1486 if (!destroy_vm || JDK_Version::is_jdk12x_version()) { 1487 // JSR-166: change call from from ThreadGroup.uncaughtException to 1488 // java.lang.Thread.dispatchUncaughtException 1489 if (uncaught_exception.not_null()) { 1490 Handle group(this, java_lang_Thread::threadGroup(threadObj())); 1491 Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT", 1492 (address)uncaught_exception(), (address)threadObj(), (address)group()); 1493 { 1494 EXCEPTION_MARK; 1495 // Check if the method Thread.dispatchUncaughtException() exists. If so 1496 // call it. Otherwise we have an older library without the JSR-166 changes, 1497 // so call ThreadGroup.uncaughtException() 1498 KlassHandle recvrKlass(THREAD, threadObj->klass()); 1499 CallInfo callinfo; 1500 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass()); 1501 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass, 1502 vmSymbolHandles::dispatchUncaughtException_name(), 1503 vmSymbolHandles::throwable_void_signature(), 1504 KlassHandle(), false, false, THREAD); 1505 CLEAR_PENDING_EXCEPTION; 1506 methodHandle method = callinfo.selected_method(); 1507 if (method.not_null()) { 1508 JavaValue result(T_VOID); 1509 JavaCalls::call_virtual(&result, 1510 threadObj, thread_klass, 1511 vmSymbolHandles::dispatchUncaughtException_name(), 1512 vmSymbolHandles::throwable_void_signature(), 1513 uncaught_exception, 1514 THREAD); 1515 } else { 1516 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass()); 1517 JavaValue result(T_VOID); 1518 JavaCalls::call_virtual(&result, 1519 group, thread_group, 1520 vmSymbolHandles::uncaughtException_name(), 1521 vmSymbolHandles::thread_throwable_void_signature(), 1522 threadObj, // Arg 1 1523 uncaught_exception, // Arg 2 1524 THREAD); 1525 } 1526 CLEAR_PENDING_EXCEPTION; 1527 } 1528 } 1529 1530 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during 1531 // the execution of the method. If that is not enough, then we don't really care. Thread.stop 1532 // is deprecated anyhow. 1533 { int count = 3; 1534 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) { 1535 EXCEPTION_MARK; 1536 JavaValue result(T_VOID); 1537 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass()); 1538 JavaCalls::call_virtual(&result, 1539 threadObj, thread_klass, 1540 vmSymbolHandles::exit_method_name(), 1541 vmSymbolHandles::void_method_signature(), 1542 THREAD); 1543 CLEAR_PENDING_EXCEPTION; 1544 } 1545 } 1546 1547 // notify JVMTI 1548 if (JvmtiExport::should_post_thread_life()) { 1549 JvmtiExport::post_thread_end(this); 1550 } 1551 1552 // We have notified the agents that we are exiting, before we go on, 1553 // we must check for a pending external suspend request and honor it 1554 // in order to not surprise the thread that made the suspend request. 1555 while (true) { 1556 { 1557 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1558 if (!is_external_suspend()) { 1559 set_terminated(_thread_exiting); 1560 ThreadService::current_thread_exiting(this); 1561 break; 1562 } 1563 // Implied else: 1564 // Things get a little tricky here. We have a pending external 1565 // suspend request, but we are holding the SR_lock so we 1566 // can't just self-suspend. So we temporarily drop the lock 1567 // and then self-suspend. 1568 } 1569 1570 ThreadBlockInVM tbivm(this); 1571 java_suspend_self(); 1572 1573 // We're done with this suspend request, but we have to loop around 1574 // and check again. Eventually we will get SR_lock without a pending 1575 // external suspend request and will be able to mark ourselves as 1576 // exiting. 1577 } 1578 // no more external suspends are allowed at this point 1579 } else { 1580 // before_exit() has already posted JVMTI THREAD_END events 1581 } 1582 1583 // Notify waiters on thread object. This has to be done after exit() is called 1584 // on the thread (if the thread is the last thread in a daemon ThreadGroup the 1585 // group should have the destroyed bit set before waiters are notified). 1586 ensure_join(this); 1587 assert(!this->has_pending_exception(), "ensure_join should have cleared"); 1588 1589 // 6282335 JNI DetachCurrentThread spec states that all Java monitors 1590 // held by this thread must be released. A detach operation must only 1591 // get here if there are no Java frames on the stack. Therefore, any 1592 // owned monitors at this point MUST be JNI-acquired monitors which are 1593 // pre-inflated and in the monitor cache. 1594 // 1595 // ensure_join() ignores IllegalThreadStateExceptions, and so does this. 1596 if (exit_type == jni_detach && JNIDetachReleasesMonitors) { 1597 assert(!this->has_last_Java_frame(), "detaching with Java frames?"); 1598 ObjectSynchronizer::release_monitors_owned_by_thread(this); 1599 assert(!this->has_pending_exception(), "release_monitors should have cleared"); 1600 } 1601 1602 // These things needs to be done while we are still a Java Thread. Make sure that thread 1603 // is in a consistent state, in case GC happens 1604 assert(_privileged_stack_top == NULL, "must be NULL when we get here"); 1605 1606 if (active_handles() != NULL) { 1607 JNIHandleBlock* block = active_handles(); 1608 set_active_handles(NULL); 1609 JNIHandleBlock::release_block(block); 1610 } 1611 1612 if (free_handle_block() != NULL) { 1613 JNIHandleBlock* block = free_handle_block(); 1614 set_free_handle_block(NULL); 1615 JNIHandleBlock::release_block(block); 1616 } 1617 1618 // These have to be removed while this is still a valid thread. 1619 remove_stack_guard_pages(); 1620 1621 if (UseTLAB) { 1622 tlab().make_parsable(true); // retire TLAB 1623 } 1624 1625 if (jvmti_thread_state() != NULL) { 1626 JvmtiExport::cleanup_thread(this); 1627 } 1628 1629#ifndef SERIALGC 1630 // We must flush G1-related buffers before removing a thread from 1631 // the list of active threads. 1632 if (UseG1GC) { 1633 flush_barrier_queues(); 1634 } 1635#endif 1636 1637 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread 1638 Threads::remove(this); 1639} 1640 1641#ifndef SERIALGC 1642// Flush G1-related queues. 1643void JavaThread::flush_barrier_queues() { 1644 satb_mark_queue().flush(); 1645 dirty_card_queue().flush(); 1646} 1647#endif 1648 1649void JavaThread::cleanup_failed_attach_current_thread() { 1650 if (get_thread_profiler() != NULL) { 1651 get_thread_profiler()->disengage(); 1652 ResourceMark rm; 1653 get_thread_profiler()->print(get_thread_name()); 1654 } 1655 1656 if (active_handles() != NULL) { 1657 JNIHandleBlock* block = active_handles(); 1658 set_active_handles(NULL); 1659 JNIHandleBlock::release_block(block); 1660 } 1661 1662 if (free_handle_block() != NULL) { 1663 JNIHandleBlock* block = free_handle_block(); 1664 set_free_handle_block(NULL); 1665 JNIHandleBlock::release_block(block); 1666 } 1667 1668 // These have to be removed while this is still a valid thread. 1669 remove_stack_guard_pages(); 1670 1671 if (UseTLAB) { 1672 tlab().make_parsable(true); // retire TLAB, if any 1673 } 1674 1675#ifndef SERIALGC 1676 if (UseG1GC) { 1677 flush_barrier_queues(); 1678 } 1679#endif 1680 1681 Threads::remove(this); 1682 delete this; 1683} 1684 1685 1686 1687 1688JavaThread* JavaThread::active() { 1689 Thread* thread = ThreadLocalStorage::thread(); 1690 assert(thread != NULL, "just checking"); 1691 if (thread->is_Java_thread()) { 1692 return (JavaThread*) thread; 1693 } else { 1694 assert(thread->is_VM_thread(), "this must be a vm thread"); 1695 VM_Operation* op = ((VMThread*) thread)->vm_operation(); 1696 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread(); 1697 assert(ret->is_Java_thread(), "must be a Java thread"); 1698 return ret; 1699 } 1700} 1701 1702bool JavaThread::is_lock_owned(address adr) const { 1703 if (Thread::is_lock_owned(adr)) return true; 1704 1705 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { 1706 if (chunk->contains(adr)) return true; 1707 } 1708 1709 return false; 1710} 1711 1712 1713void JavaThread::add_monitor_chunk(MonitorChunk* chunk) { 1714 chunk->set_next(monitor_chunks()); 1715 set_monitor_chunks(chunk); 1716} 1717 1718void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) { 1719 guarantee(monitor_chunks() != NULL, "must be non empty"); 1720 if (monitor_chunks() == chunk) { 1721 set_monitor_chunks(chunk->next()); 1722 } else { 1723 MonitorChunk* prev = monitor_chunks(); 1724 while (prev->next() != chunk) prev = prev->next(); 1725 prev->set_next(chunk->next()); 1726 } 1727} 1728 1729// JVM support. 1730 1731// Note: this function shouldn't block if it's called in 1732// _thread_in_native_trans state (such as from 1733// check_special_condition_for_native_trans()). 1734void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) { 1735 1736 if (has_last_Java_frame() && has_async_condition()) { 1737 // If we are at a polling page safepoint (not a poll return) 1738 // then we must defer async exception because live registers 1739 // will be clobbered by the exception path. Poll return is 1740 // ok because the call we a returning from already collides 1741 // with exception handling registers and so there is no issue. 1742 // (The exception handling path kills call result registers but 1743 // this is ok since the exception kills the result anyway). 1744 1745 if (is_at_poll_safepoint()) { 1746 // if the code we are returning to has deoptimized we must defer 1747 // the exception otherwise live registers get clobbered on the 1748 // exception path before deoptimization is able to retrieve them. 1749 // 1750 RegisterMap map(this, false); 1751 frame caller_fr = last_frame().sender(&map); 1752 assert(caller_fr.is_compiled_frame(), "what?"); 1753 if (caller_fr.is_deoptimized_frame()) { 1754 if (TraceExceptions) { 1755 ResourceMark rm; 1756 tty->print_cr("deferred async exception at compiled safepoint"); 1757 } 1758 return; 1759 } 1760 } 1761 } 1762 1763 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition(); 1764 if (condition == _no_async_condition) { 1765 // Conditions have changed since has_special_runtime_exit_condition() 1766 // was called: 1767 // - if we were here only because of an external suspend request, 1768 // then that was taken care of above (or cancelled) so we are done 1769 // - if we were here because of another async request, then it has 1770 // been cleared between the has_special_runtime_exit_condition() 1771 // and now so again we are done 1772 return; 1773 } 1774 1775 // Check for pending async. exception 1776 if (_pending_async_exception != NULL) { 1777 // Only overwrite an already pending exception, if it is not a threadDeath. 1778 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) { 1779 1780 // We cannot call Exceptions::_throw(...) here because we cannot block 1781 set_pending_exception(_pending_async_exception, __FILE__, __LINE__); 1782 1783 if (TraceExceptions) { 1784 ResourceMark rm; 1785 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this); 1786 if (has_last_Java_frame() ) { 1787 frame f = last_frame(); 1788 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp()); 1789 } 1790 tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name()); 1791 } 1792 _pending_async_exception = NULL; 1793 clear_has_async_exception(); 1794 } 1795 } 1796 1797 if (check_unsafe_error && 1798 condition == _async_unsafe_access_error && !has_pending_exception()) { 1799 condition = _no_async_condition; // done 1800 switch (thread_state()) { 1801 case _thread_in_vm: 1802 { 1803 JavaThread* THREAD = this; 1804 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); 1805 } 1806 case _thread_in_native: 1807 { 1808 ThreadInVMfromNative tiv(this); 1809 JavaThread* THREAD = this; 1810 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); 1811 } 1812 case _thread_in_Java: 1813 { 1814 ThreadInVMfromJava tiv(this); 1815 JavaThread* THREAD = this; 1816 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code"); 1817 } 1818 default: 1819 ShouldNotReachHere(); 1820 } 1821 } 1822 1823 assert(condition == _no_async_condition || has_pending_exception() || 1824 (!check_unsafe_error && condition == _async_unsafe_access_error), 1825 "must have handled the async condition, if no exception"); 1826} 1827 1828void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) { 1829 // 1830 // Check for pending external suspend. Internal suspend requests do 1831 // not use handle_special_runtime_exit_condition(). 1832 // If JNIEnv proxies are allowed, don't self-suspend if the target 1833 // thread is not the current thread. In older versions of jdbx, jdbx 1834 // threads could call into the VM with another thread's JNIEnv so we 1835 // can be here operating on behalf of a suspended thread (4432884). 1836 bool do_self_suspend = is_external_suspend_with_lock(); 1837 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) { 1838 // 1839 // Because thread is external suspended the safepoint code will count 1840 // thread as at a safepoint. This can be odd because we can be here 1841 // as _thread_in_Java which would normally transition to _thread_blocked 1842 // at a safepoint. We would like to mark the thread as _thread_blocked 1843 // before calling java_suspend_self like all other callers of it but 1844 // we must then observe proper safepoint protocol. (We can't leave 1845 // _thread_blocked with a safepoint in progress). However we can be 1846 // here as _thread_in_native_trans so we can't use a normal transition 1847 // constructor/destructor pair because they assert on that type of 1848 // transition. We could do something like: 1849 // 1850 // JavaThreadState state = thread_state(); 1851 // set_thread_state(_thread_in_vm); 1852 // { 1853 // ThreadBlockInVM tbivm(this); 1854 // java_suspend_self() 1855 // } 1856 // set_thread_state(_thread_in_vm_trans); 1857 // if (safepoint) block; 1858 // set_thread_state(state); 1859 // 1860 // but that is pretty messy. Instead we just go with the way the 1861 // code has worked before and note that this is the only path to 1862 // java_suspend_self that doesn't put the thread in _thread_blocked 1863 // mode. 1864 1865 frame_anchor()->make_walkable(this); 1866 java_suspend_self(); 1867 1868 // We might be here for reasons in addition to the self-suspend request 1869 // so check for other async requests. 1870 } 1871 1872 if (check_asyncs) { 1873 check_and_handle_async_exceptions(); 1874 } 1875} 1876 1877void JavaThread::send_thread_stop(oop java_throwable) { 1878 assert(Thread::current()->is_VM_thread(), "should be in the vm thread"); 1879 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code"); 1880 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); 1881 1882 // Do not throw asynchronous exceptions against the compiler thread 1883 // (the compiler thread should not be a Java thread -- fix in 1.4.2) 1884 if (is_Compiler_thread()) return; 1885 1886 // This is a change from JDK 1.1, but JDK 1.2 will also do it: 1887 if (java_throwable->is_a(SystemDictionary::ThreadDeath_klass())) { 1888 java_lang_Thread::set_stillborn(threadObj()); 1889 } 1890 1891 { 1892 // Actually throw the Throwable against the target Thread - however 1893 // only if there is no thread death exception installed already. 1894 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) { 1895 // If the topmost frame is a runtime stub, then we are calling into 1896 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) 1897 // must deoptimize the caller before continuing, as the compiled exception handler table 1898 // may not be valid 1899 if (has_last_Java_frame()) { 1900 frame f = last_frame(); 1901 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) { 1902 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 1903 RegisterMap reg_map(this, UseBiasedLocking); 1904 frame compiled_frame = f.sender(®_map); 1905 if (compiled_frame.can_be_deoptimized()) { 1906 Deoptimization::deoptimize(this, compiled_frame, ®_map); 1907 } 1908 } 1909 } 1910 1911 // Set async. pending exception in thread. 1912 set_pending_async_exception(java_throwable); 1913 1914 if (TraceExceptions) { 1915 ResourceMark rm; 1916 tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name()); 1917 } 1918 // for AbortVMOnException flag 1919 NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name())); 1920 } 1921 } 1922 1923 1924 // Interrupt thread so it will wake up from a potential wait() 1925 Thread::interrupt(this); 1926} 1927 1928// External suspension mechanism. 1929// 1930// Tell the VM to suspend a thread when ever it knows that it does not hold on 1931// to any VM_locks and it is at a transition 1932// Self-suspension will happen on the transition out of the vm. 1933// Catch "this" coming in from JNIEnv pointers when the thread has been freed 1934// 1935// Guarantees on return: 1936// + Target thread will not execute any new bytecode (that's why we need to 1937// force a safepoint) 1938// + Target thread will not enter any new monitors 1939// 1940void JavaThread::java_suspend() { 1941 { MutexLocker mu(Threads_lock); 1942 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) { 1943 return; 1944 } 1945 } 1946 1947 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1948 if (!is_external_suspend()) { 1949 // a racing resume has cancelled us; bail out now 1950 return; 1951 } 1952 1953 // suspend is done 1954 uint32_t debug_bits = 0; 1955 // Warning: is_ext_suspend_completed() may temporarily drop the 1956 // SR_lock to allow the thread to reach a stable thread state if 1957 // it is currently in a transient thread state. 1958 if (is_ext_suspend_completed(false /* !called_by_wait */, 1959 SuspendRetryDelay, &debug_bits) ) { 1960 return; 1961 } 1962 } 1963 1964 VM_ForceSafepoint vm_suspend; 1965 VMThread::execute(&vm_suspend); 1966} 1967 1968// Part II of external suspension. 1969// A JavaThread self suspends when it detects a pending external suspend 1970// request. This is usually on transitions. It is also done in places 1971// where continuing to the next transition would surprise the caller, 1972// e.g., monitor entry. 1973// 1974// Returns the number of times that the thread self-suspended. 1975// 1976// Note: DO NOT call java_suspend_self() when you just want to block current 1977// thread. java_suspend_self() is the second stage of cooperative 1978// suspension for external suspend requests and should only be used 1979// to complete an external suspend request. 1980// 1981int JavaThread::java_suspend_self() { 1982 int ret = 0; 1983 1984 // we are in the process of exiting so don't suspend 1985 if (is_exiting()) { 1986 clear_external_suspend(); 1987 return ret; 1988 } 1989 1990 assert(_anchor.walkable() || 1991 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()), 1992 "must have walkable stack"); 1993 1994 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1995 1996 assert(!this->is_ext_suspended(), 1997 "a thread trying to self-suspend should not already be suspended"); 1998 1999 if (this->is_suspend_equivalent()) { 2000 // If we are self-suspending as a result of the lifting of a 2001 // suspend equivalent condition, then the suspend_equivalent 2002 // flag is not cleared until we set the ext_suspended flag so 2003 // that wait_for_ext_suspend_completion() returns consistent 2004 // results. 2005 this->clear_suspend_equivalent(); 2006 } 2007 2008 // A racing resume may have cancelled us before we grabbed SR_lock 2009 // above. Or another external suspend request could be waiting for us 2010 // by the time we return from SR_lock()->wait(). The thread 2011 // that requested the suspension may already be trying to walk our 2012 // stack and if we return now, we can change the stack out from under 2013 // it. This would be a "bad thing (TM)" and cause the stack walker 2014 // to crash. We stay self-suspended until there are no more pending 2015 // external suspend requests. 2016 while (is_external_suspend()) { 2017 ret++; 2018 this->set_ext_suspended(); 2019 2020 // _ext_suspended flag is cleared by java_resume() 2021 while (is_ext_suspended()) { 2022 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag); 2023 } 2024 } 2025 2026 return ret; 2027} 2028 2029#ifdef ASSERT 2030// verify the JavaThread has not yet been published in the Threads::list, and 2031// hence doesn't need protection from concurrent access at this stage 2032void JavaThread::verify_not_published() { 2033 if (!Threads_lock->owned_by_self()) { 2034 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag); 2035 assert( !Threads::includes(this), 2036 "java thread shouldn't have been published yet!"); 2037 } 2038 else { 2039 assert( !Threads::includes(this), 2040 "java thread shouldn't have been published yet!"); 2041 } 2042} 2043#endif 2044 2045// Slow path when the native==>VM/Java barriers detect a safepoint is in 2046// progress or when _suspend_flags is non-zero. 2047// Current thread needs to self-suspend if there is a suspend request and/or 2048// block if a safepoint is in progress. 2049// Async exception ISN'T checked. 2050// Note only the ThreadInVMfromNative transition can call this function 2051// directly and when thread state is _thread_in_native_trans 2052void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) { 2053 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); 2054 2055 JavaThread *curJT = JavaThread::current(); 2056 bool do_self_suspend = thread->is_external_suspend(); 2057 2058 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition"); 2059 2060 // If JNIEnv proxies are allowed, don't self-suspend if the target 2061 // thread is not the current thread. In older versions of jdbx, jdbx 2062 // threads could call into the VM with another thread's JNIEnv so we 2063 // can be here operating on behalf of a suspended thread (4432884). 2064 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) { 2065 JavaThreadState state = thread->thread_state(); 2066 2067 // We mark this thread_blocked state as a suspend-equivalent so 2068 // that a caller to is_ext_suspend_completed() won't be confused. 2069 // The suspend-equivalent state is cleared by java_suspend_self(). 2070 thread->set_suspend_equivalent(); 2071 2072 // If the safepoint code sees the _thread_in_native_trans state, it will 2073 // wait until the thread changes to other thread state. There is no 2074 // guarantee on how soon we can obtain the SR_lock and complete the 2075 // self-suspend request. It would be a bad idea to let safepoint wait for 2076 // too long. Temporarily change the state to _thread_blocked to 2077 // let the VM thread know that this thread is ready for GC. The problem 2078 // of changing thread state is that safepoint could happen just after 2079 // java_suspend_self() returns after being resumed, and VM thread will 2080 // see the _thread_blocked state. We must check for safepoint 2081 // after restoring the state and make sure we won't leave while a safepoint 2082 // is in progress. 2083 thread->set_thread_state(_thread_blocked); 2084 thread->java_suspend_self(); 2085 thread->set_thread_state(state); 2086 // Make sure new state is seen by VM thread 2087 if (os::is_MP()) { 2088 if (UseMembar) { 2089 // Force a fence between the write above and read below 2090 OrderAccess::fence(); 2091 } else { 2092 // Must use this rather than serialization page in particular on Windows 2093 InterfaceSupport::serialize_memory(thread); 2094 } 2095 } 2096 } 2097 2098 if (SafepointSynchronize::do_call_back()) { 2099 // If we are safepointing, then block the caller which may not be 2100 // the same as the target thread (see above). 2101 SafepointSynchronize::block(curJT); 2102 } 2103 2104 if (thread->is_deopt_suspend()) { 2105 thread->clear_deopt_suspend(); 2106 RegisterMap map(thread, false); 2107 frame f = thread->last_frame(); 2108 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) { 2109 f = f.sender(&map); 2110 } 2111 if (f.id() == thread->must_deopt_id()) { 2112 thread->clear_must_deopt_id(); 2113 // Since we know we're safe to deopt the current state is a safe state 2114 f.deoptimize(thread, true); 2115 } else { 2116 fatal("missed deoptimization!"); 2117 } 2118 } 2119} 2120 2121// Slow path when the native==>VM/Java barriers detect a safepoint is in 2122// progress or when _suspend_flags is non-zero. 2123// Current thread needs to self-suspend if there is a suspend request and/or 2124// block if a safepoint is in progress. 2125// Also check for pending async exception (not including unsafe access error). 2126// Note only the native==>VM/Java barriers can call this function and when 2127// thread state is _thread_in_native_trans. 2128void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { 2129 check_safepoint_and_suspend_for_native_trans(thread); 2130 2131 if (thread->has_async_exception()) { 2132 // We are in _thread_in_native_trans state, don't handle unsafe 2133 // access error since that may block. 2134 thread->check_and_handle_async_exceptions(false); 2135 } 2136} 2137 2138// We need to guarantee the Threads_lock here, since resumes are not 2139// allowed during safepoint synchronization 2140// Can only resume from an external suspension 2141void JavaThread::java_resume() { 2142 assert_locked_or_safepoint(Threads_lock); 2143 2144 // Sanity check: thread is gone, has started exiting or the thread 2145 // was not externally suspended. 2146 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) { 2147 return; 2148 } 2149 2150 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 2151 2152 clear_external_suspend(); 2153 2154 if (is_ext_suspended()) { 2155 clear_ext_suspended(); 2156 SR_lock()->notify_all(); 2157 } 2158} 2159 2160void JavaThread::create_stack_guard_pages() { 2161 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return; 2162 address low_addr = stack_base() - stack_size(); 2163 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); 2164 2165 int allocate = os::allocate_stack_guard_pages(); 2166 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len); 2167 2168 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) { 2169 warning("Attempt to allocate stack guard pages failed."); 2170 return; 2171 } 2172 2173 if (os::guard_memory((char *) low_addr, len)) { 2174 _stack_guard_state = stack_guard_enabled; 2175 } else { 2176 warning("Attempt to protect stack guard pages failed."); 2177 if (os::uncommit_memory((char *) low_addr, len)) { 2178 warning("Attempt to deallocate stack guard pages failed."); 2179 } 2180 } 2181} 2182 2183void JavaThread::remove_stack_guard_pages() { 2184 if (_stack_guard_state == stack_guard_unused) return; 2185 address low_addr = stack_base() - stack_size(); 2186 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); 2187 2188 if (os::allocate_stack_guard_pages()) { 2189 if (os::remove_stack_guard_pages((char *) low_addr, len)) { 2190 _stack_guard_state = stack_guard_unused; 2191 } else { 2192 warning("Attempt to deallocate stack guard pages failed."); 2193 } 2194 } else { 2195 if (_stack_guard_state == stack_guard_unused) return; 2196 if (os::unguard_memory((char *) low_addr, len)) { 2197 _stack_guard_state = stack_guard_unused; 2198 } else { 2199 warning("Attempt to unprotect stack guard pages failed."); 2200 } 2201 } 2202} 2203 2204void JavaThread::enable_stack_yellow_zone() { 2205 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2206 assert(_stack_guard_state != stack_guard_enabled, "already enabled"); 2207 2208 // The base notation is from the stacks point of view, growing downward. 2209 // We need to adjust it to work correctly with guard_memory() 2210 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); 2211 2212 guarantee(base < stack_base(),"Error calculating stack yellow zone"); 2213 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone"); 2214 2215 if (os::guard_memory((char *) base, stack_yellow_zone_size())) { 2216 _stack_guard_state = stack_guard_enabled; 2217 } else { 2218 warning("Attempt to guard stack yellow zone failed."); 2219 } 2220 enable_register_stack_guard(); 2221} 2222 2223void JavaThread::disable_stack_yellow_zone() { 2224 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2225 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled"); 2226 2227 // Simply return if called for a thread that does not use guard pages. 2228 if (_stack_guard_state == stack_guard_unused) return; 2229 2230 // The base notation is from the stacks point of view, growing downward. 2231 // We need to adjust it to work correctly with guard_memory() 2232 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); 2233 2234 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) { 2235 _stack_guard_state = stack_guard_yellow_disabled; 2236 } else { 2237 warning("Attempt to unguard stack yellow zone failed."); 2238 } 2239 disable_register_stack_guard(); 2240} 2241 2242void JavaThread::enable_stack_red_zone() { 2243 // The base notation is from the stacks point of view, growing downward. 2244 // We need to adjust it to work correctly with guard_memory() 2245 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2246 address base = stack_red_zone_base() - stack_red_zone_size(); 2247 2248 guarantee(base < stack_base(),"Error calculating stack red zone"); 2249 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone"); 2250 2251 if(!os::guard_memory((char *) base, stack_red_zone_size())) { 2252 warning("Attempt to guard stack red zone failed."); 2253 } 2254} 2255 2256void JavaThread::disable_stack_red_zone() { 2257 // The base notation is from the stacks point of view, growing downward. 2258 // We need to adjust it to work correctly with guard_memory() 2259 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2260 address base = stack_red_zone_base() - stack_red_zone_size(); 2261 if (!os::unguard_memory((char *)base, stack_red_zone_size())) { 2262 warning("Attempt to unguard stack red zone failed."); 2263 } 2264} 2265 2266void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { 2267 // ignore is there is no stack 2268 if (!has_last_Java_frame()) return; 2269 // traverse the stack frames. Starts from top frame. 2270 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2271 frame* fr = fst.current(); 2272 f(fr, fst.register_map()); 2273 } 2274} 2275 2276 2277#ifndef PRODUCT 2278// Deoptimization 2279// Function for testing deoptimization 2280void JavaThread::deoptimize() { 2281 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 2282 StackFrameStream fst(this, UseBiasedLocking); 2283 bool deopt = false; // Dump stack only if a deopt actually happens. 2284 bool only_at = strlen(DeoptimizeOnlyAt) > 0; 2285 // Iterate over all frames in the thread and deoptimize 2286 for(; !fst.is_done(); fst.next()) { 2287 if(fst.current()->can_be_deoptimized()) { 2288 2289 if (only_at) { 2290 // Deoptimize only at particular bcis. DeoptimizeOnlyAt 2291 // consists of comma or carriage return separated numbers so 2292 // search for the current bci in that string. 2293 address pc = fst.current()->pc(); 2294 nmethod* nm = (nmethod*) fst.current()->cb(); 2295 ScopeDesc* sd = nm->scope_desc_at( pc); 2296 char buffer[8]; 2297 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); 2298 size_t len = strlen(buffer); 2299 const char * found = strstr(DeoptimizeOnlyAt, buffer); 2300 while (found != NULL) { 2301 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && 2302 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { 2303 // Check that the bci found is bracketed by terminators. 2304 break; 2305 } 2306 found = strstr(found + 1, buffer); 2307 } 2308 if (!found) { 2309 continue; 2310 } 2311 } 2312 2313 if (DebugDeoptimization && !deopt) { 2314 deopt = true; // One-time only print before deopt 2315 tty->print_cr("[BEFORE Deoptimization]"); 2316 trace_frames(); 2317 trace_stack(); 2318 } 2319 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); 2320 } 2321 } 2322 2323 if (DebugDeoptimization && deopt) { 2324 tty->print_cr("[AFTER Deoptimization]"); 2325 trace_frames(); 2326 } 2327} 2328 2329 2330// Make zombies 2331void JavaThread::make_zombies() { 2332 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2333 if (fst.current()->can_be_deoptimized()) { 2334 // it is a Java nmethod 2335 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); 2336 nm->make_not_entrant(); 2337 } 2338 } 2339} 2340#endif // PRODUCT 2341 2342 2343void JavaThread::deoptimized_wrt_marked_nmethods() { 2344 if (!has_last_Java_frame()) return; 2345 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 2346 StackFrameStream fst(this, UseBiasedLocking); 2347 for(; !fst.is_done(); fst.next()) { 2348 if (fst.current()->should_be_deoptimized()) { 2349 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); 2350 } 2351 } 2352} 2353 2354 2355// GC support 2356static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); } 2357 2358void JavaThread::gc_epilogue() { 2359 frames_do(frame_gc_epilogue); 2360} 2361 2362 2363static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); } 2364 2365void JavaThread::gc_prologue() { 2366 frames_do(frame_gc_prologue); 2367} 2368 2369// If the caller is a NamedThread, then remember, in the current scope, 2370// the given JavaThread in its _processed_thread field. 2371class RememberProcessedThread: public StackObj { 2372 NamedThread* _cur_thr; 2373public: 2374 RememberProcessedThread(JavaThread* jthr) { 2375 Thread* thread = Thread::current(); 2376 if (thread->is_Named_thread()) { 2377 _cur_thr = (NamedThread *)thread; 2378 _cur_thr->set_processed_thread(jthr); 2379 } else { 2380 _cur_thr = NULL; 2381 } 2382 } 2383 2384 ~RememberProcessedThread() { 2385 if (_cur_thr) { 2386 _cur_thr->set_processed_thread(NULL); 2387 } 2388 } 2389}; 2390 2391void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) { 2392 // Verify that the deferred card marks have been flushed. 2393 assert(deferred_card_mark().is_empty(), "Should be empty during GC"); 2394 2395 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do 2396 // since there may be more than one thread using each ThreadProfiler. 2397 2398 // Traverse the GCHandles 2399 Thread::oops_do(f, cf); 2400 2401 assert( (!has_last_Java_frame() && java_call_counter() == 0) || 2402 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); 2403 2404 if (has_last_Java_frame()) { 2405 // Record JavaThread to GC thread 2406 RememberProcessedThread rpt(this); 2407 2408 // Traverse the privileged stack 2409 if (_privileged_stack_top != NULL) { 2410 _privileged_stack_top->oops_do(f); 2411 } 2412 2413 // traverse the registered growable array 2414 if (_array_for_gc != NULL) { 2415 for (int index = 0; index < _array_for_gc->length(); index++) { 2416 f->do_oop(_array_for_gc->adr_at(index)); 2417 } 2418 } 2419 2420 // Traverse the monitor chunks 2421 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { 2422 chunk->oops_do(f); 2423 } 2424 2425 // Traverse the execution stack 2426 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2427 fst.current()->oops_do(f, cf, fst.register_map()); 2428 } 2429 } 2430 2431 // callee_target is never live across a gc point so NULL it here should 2432 // it still contain a methdOop. 2433 2434 set_callee_target(NULL); 2435 2436 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!"); 2437 // If we have deferred set_locals there might be oops waiting to be 2438 // written 2439 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals(); 2440 if (list != NULL) { 2441 for (int i = 0; i < list->length(); i++) { 2442 list->at(i)->oops_do(f); 2443 } 2444 } 2445 2446 // Traverse instance variables at the end since the GC may be moving things 2447 // around using this function 2448 f->do_oop((oop*) &_threadObj); 2449 f->do_oop((oop*) &_vm_result); 2450 f->do_oop((oop*) &_vm_result_2); 2451 f->do_oop((oop*) &_exception_oop); 2452 f->do_oop((oop*) &_pending_async_exception); 2453 2454 if (jvmti_thread_state() != NULL) { 2455 jvmti_thread_state()->oops_do(f); 2456 } 2457} 2458 2459void JavaThread::nmethods_do(CodeBlobClosure* cf) { 2460 Thread::nmethods_do(cf); // (super method is a no-op) 2461 2462 assert( (!has_last_Java_frame() && java_call_counter() == 0) || 2463 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); 2464 2465 if (has_last_Java_frame()) { 2466 // Traverse the execution stack 2467 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2468 fst.current()->nmethods_do(cf); 2469 } 2470 } 2471} 2472 2473// Printing 2474const char* _get_thread_state_name(JavaThreadState _thread_state) { 2475 switch (_thread_state) { 2476 case _thread_uninitialized: return "_thread_uninitialized"; 2477 case _thread_new: return "_thread_new"; 2478 case _thread_new_trans: return "_thread_new_trans"; 2479 case _thread_in_native: return "_thread_in_native"; 2480 case _thread_in_native_trans: return "_thread_in_native_trans"; 2481 case _thread_in_vm: return "_thread_in_vm"; 2482 case _thread_in_vm_trans: return "_thread_in_vm_trans"; 2483 case _thread_in_Java: return "_thread_in_Java"; 2484 case _thread_in_Java_trans: return "_thread_in_Java_trans"; 2485 case _thread_blocked: return "_thread_blocked"; 2486 case _thread_blocked_trans: return "_thread_blocked_trans"; 2487 default: return "unknown thread state"; 2488 } 2489} 2490 2491#ifndef PRODUCT 2492void JavaThread::print_thread_state_on(outputStream *st) const { 2493 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); 2494}; 2495void JavaThread::print_thread_state() const { 2496 print_thread_state_on(tty); 2497}; 2498#endif // PRODUCT 2499 2500// Called by Threads::print() for VM_PrintThreads operation 2501void JavaThread::print_on(outputStream *st) const { 2502 st->print("\"%s\" ", get_thread_name()); 2503 oop thread_oop = threadObj(); 2504 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); 2505 Thread::print_on(st); 2506 // print guess for valid stack memory region (assume 4K pages); helps lock debugging 2507 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12)); 2508 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) { 2509 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); 2510 } 2511#ifndef PRODUCT 2512 print_thread_state_on(st); 2513 _safepoint_state->print_on(st); 2514#endif // PRODUCT 2515} 2516 2517// Called by fatal error handler. The difference between this and 2518// JavaThread::print() is that we can't grab lock or allocate memory. 2519void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { 2520 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen)); 2521 oop thread_obj = threadObj(); 2522 if (thread_obj != NULL) { 2523 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon"); 2524 } 2525 st->print(" ["); 2526 st->print("%s", _get_thread_state_name(_thread_state)); 2527 if (osthread()) { 2528 st->print(", id=%d", osthread()->thread_id()); 2529 } 2530 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")", 2531 _stack_base - _stack_size, _stack_base); 2532 st->print("]"); 2533 return; 2534} 2535 2536// Verification 2537 2538static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } 2539 2540void JavaThread::verify() { 2541 // Verify oops in the thread. 2542 oops_do(&VerifyOopClosure::verify_oop, NULL); 2543 2544 // Verify the stack frames. 2545 frames_do(frame_verify); 2546} 2547 2548// CR 6300358 (sub-CR 2137150) 2549// Most callers of this method assume that it can't return NULL but a 2550// thread may not have a name whilst it is in the process of attaching to 2551// the VM - see CR 6412693, and there are places where a JavaThread can be 2552// seen prior to having it's threadObj set (eg JNI attaching threads and 2553// if vm exit occurs during initialization). These cases can all be accounted 2554// for such that this method never returns NULL. 2555const char* JavaThread::get_thread_name() const { 2556#ifdef ASSERT 2557 // early safepoints can hit while current thread does not yet have TLS 2558 if (!SafepointSynchronize::is_at_safepoint()) { 2559 Thread *cur = Thread::current(); 2560 if (!(cur->is_Java_thread() && cur == this)) { 2561 // Current JavaThreads are allowed to get their own name without 2562 // the Threads_lock. 2563 assert_locked_or_safepoint(Threads_lock); 2564 } 2565 } 2566#endif // ASSERT 2567 return get_thread_name_string(); 2568} 2569 2570// Returns a non-NULL representation of this thread's name, or a suitable 2571// descriptive string if there is no set name 2572const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { 2573 const char* name_str; 2574 oop thread_obj = threadObj(); 2575 if (thread_obj != NULL) { 2576 typeArrayOop name = java_lang_Thread::name(thread_obj); 2577 if (name != NULL) { 2578 if (buf == NULL) { 2579 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2580 } 2581 else { 2582 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen); 2583 } 2584 } 2585 else if (is_attaching()) { // workaround for 6412693 - see 6404306 2586 name_str = "<no-name - thread is attaching>"; 2587 } 2588 else { 2589 name_str = Thread::name(); 2590 } 2591 } 2592 else { 2593 name_str = Thread::name(); 2594 } 2595 assert(name_str != NULL, "unexpected NULL thread name"); 2596 return name_str; 2597} 2598 2599 2600const char* JavaThread::get_threadgroup_name() const { 2601 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) 2602 oop thread_obj = threadObj(); 2603 if (thread_obj != NULL) { 2604 oop thread_group = java_lang_Thread::threadGroup(thread_obj); 2605 if (thread_group != NULL) { 2606 typeArrayOop name = java_lang_ThreadGroup::name(thread_group); 2607 // ThreadGroup.name can be null 2608 if (name != NULL) { 2609 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2610 return str; 2611 } 2612 } 2613 } 2614 return NULL; 2615} 2616 2617const char* JavaThread::get_parent_name() const { 2618 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) 2619 oop thread_obj = threadObj(); 2620 if (thread_obj != NULL) { 2621 oop thread_group = java_lang_Thread::threadGroup(thread_obj); 2622 if (thread_group != NULL) { 2623 oop parent = java_lang_ThreadGroup::parent(thread_group); 2624 if (parent != NULL) { 2625 typeArrayOop name = java_lang_ThreadGroup::name(parent); 2626 // ThreadGroup.name can be null 2627 if (name != NULL) { 2628 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2629 return str; 2630 } 2631 } 2632 } 2633 } 2634 return NULL; 2635} 2636 2637ThreadPriority JavaThread::java_priority() const { 2638 oop thr_oop = threadObj(); 2639 if (thr_oop == NULL) return NormPriority; // Bootstrapping 2640 ThreadPriority priority = java_lang_Thread::priority(thr_oop); 2641 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 2642 return priority; 2643} 2644 2645void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { 2646 2647 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); 2648 // Link Java Thread object <-> C++ Thread 2649 2650 // Get the C++ thread object (an oop) from the JNI handle (a jthread) 2651 // and put it into a new Handle. The Handle "thread_oop" can then 2652 // be used to pass the C++ thread object to other methods. 2653 2654 // Set the Java level thread object (jthread) field of the 2655 // new thread (a JavaThread *) to C++ thread object using the 2656 // "thread_oop" handle. 2657 2658 // Set the thread field (a JavaThread *) of the 2659 // oop representing the java_lang_Thread to the new thread (a JavaThread *). 2660 2661 Handle thread_oop(Thread::current(), 2662 JNIHandles::resolve_non_null(jni_thread)); 2663 assert(instanceKlass::cast(thread_oop->klass())->is_linked(), 2664 "must be initialized"); 2665 set_threadObj(thread_oop()); 2666 java_lang_Thread::set_thread(thread_oop(), this); 2667 2668 if (prio == NoPriority) { 2669 prio = java_lang_Thread::priority(thread_oop()); 2670 assert(prio != NoPriority, "A valid priority should be present"); 2671 } 2672 2673 // Push the Java priority down to the native thread; needs Threads_lock 2674 Thread::set_priority(this, prio); 2675 2676 // Add the new thread to the Threads list and set it in motion. 2677 // We must have threads lock in order to call Threads::add. 2678 // It is crucial that we do not block before the thread is 2679 // added to the Threads list for if a GC happens, then the java_thread oop 2680 // will not be visited by GC. 2681 Threads::add(this); 2682} 2683 2684oop JavaThread::current_park_blocker() { 2685 // Support for JSR-166 locks 2686 oop thread_oop = threadObj(); 2687 if (thread_oop != NULL && 2688 JDK_Version::current().supports_thread_park_blocker()) { 2689 return java_lang_Thread::park_blocker(thread_oop); 2690 } 2691 return NULL; 2692} 2693 2694 2695void JavaThread::print_stack_on(outputStream* st) { 2696 if (!has_last_Java_frame()) return; 2697 ResourceMark rm; 2698 HandleMark hm; 2699 2700 RegisterMap reg_map(this); 2701 vframe* start_vf = last_java_vframe(®_map); 2702 int count = 0; 2703 for (vframe* f = start_vf; f; f = f->sender() ) { 2704 if (f->is_java_frame()) { 2705 javaVFrame* jvf = javaVFrame::cast(f); 2706 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 2707 2708 // Print out lock information 2709 if (JavaMonitorsInStackTrace) { 2710 jvf->print_lock_info_on(st, count); 2711 } 2712 } else { 2713 // Ignore non-Java frames 2714 } 2715 2716 // Bail-out case for too deep stacks 2717 count++; 2718 if (MaxJavaStackTraceDepth == count) return; 2719 } 2720} 2721 2722 2723// JVMTI PopFrame support 2724void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { 2725 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments"); 2726 if (in_bytes(size_in_bytes) != 0) { 2727 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes)); 2728 _popframe_preserved_args_size = in_bytes(size_in_bytes); 2729 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size); 2730 } 2731} 2732 2733void* JavaThread::popframe_preserved_args() { 2734 return _popframe_preserved_args; 2735} 2736 2737ByteSize JavaThread::popframe_preserved_args_size() { 2738 return in_ByteSize(_popframe_preserved_args_size); 2739} 2740 2741WordSize JavaThread::popframe_preserved_args_size_in_words() { 2742 int sz = in_bytes(popframe_preserved_args_size()); 2743 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); 2744 return in_WordSize(sz / wordSize); 2745} 2746 2747void JavaThread::popframe_free_preserved_args() { 2748 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice"); 2749 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args); 2750 _popframe_preserved_args = NULL; 2751 _popframe_preserved_args_size = 0; 2752} 2753 2754#ifndef PRODUCT 2755 2756void JavaThread::trace_frames() { 2757 tty->print_cr("[Describe stack]"); 2758 int frame_no = 1; 2759 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2760 tty->print(" %d. ", frame_no++); 2761 fst.current()->print_value_on(tty,this); 2762 tty->cr(); 2763 } 2764} 2765 2766 2767void JavaThread::trace_stack_from(vframe* start_vf) { 2768 ResourceMark rm; 2769 int vframe_no = 1; 2770 for (vframe* f = start_vf; f; f = f->sender() ) { 2771 if (f->is_java_frame()) { 2772 javaVFrame::cast(f)->print_activation(vframe_no++); 2773 } else { 2774 f->print(); 2775 } 2776 if (vframe_no > StackPrintLimit) { 2777 tty->print_cr("...<more frames>..."); 2778 return; 2779 } 2780 } 2781} 2782 2783 2784void JavaThread::trace_stack() { 2785 if (!has_last_Java_frame()) return; 2786 ResourceMark rm; 2787 HandleMark hm; 2788 RegisterMap reg_map(this); 2789 trace_stack_from(last_java_vframe(®_map)); 2790} 2791 2792 2793#endif // PRODUCT 2794 2795 2796javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) { 2797 assert(reg_map != NULL, "a map must be given"); 2798 frame f = last_frame(); 2799 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) { 2800 if (vf->is_java_frame()) return javaVFrame::cast(vf); 2801 } 2802 return NULL; 2803} 2804 2805 2806klassOop JavaThread::security_get_caller_class(int depth) { 2807 vframeStream vfst(this); 2808 vfst.security_get_caller_frame(depth); 2809 if (!vfst.at_end()) { 2810 return vfst.method()->method_holder(); 2811 } 2812 return NULL; 2813} 2814 2815static void compiler_thread_entry(JavaThread* thread, TRAPS) { 2816 assert(thread->is_Compiler_thread(), "must be compiler thread"); 2817 CompileBroker::compiler_thread_loop(); 2818} 2819 2820// Create a CompilerThread 2821CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters) 2822: JavaThread(&compiler_thread_entry) { 2823 _env = NULL; 2824 _log = NULL; 2825 _task = NULL; 2826 _queue = queue; 2827 _counters = counters; 2828 _buffer_blob = NULL; 2829 2830#ifndef PRODUCT 2831 _ideal_graph_printer = NULL; 2832#endif 2833} 2834 2835 2836// ======= Threads ======== 2837 2838// The Threads class links together all active threads, and provides 2839// operations over all threads. It is protected by its own Mutex 2840// lock, which is also used in other contexts to protect thread 2841// operations from having the thread being operated on from exiting 2842// and going away unexpectedly (e.g., safepoint synchronization) 2843 2844JavaThread* Threads::_thread_list = NULL; 2845int Threads::_number_of_threads = 0; 2846int Threads::_number_of_non_daemon_threads = 0; 2847int Threads::_return_code = 0; 2848size_t JavaThread::_stack_size_at_create = 0; 2849 2850// All JavaThreads 2851#define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next()) 2852 2853void os_stream(); 2854 2855// All JavaThreads + all non-JavaThreads (i.e., every thread in the system) 2856void Threads::threads_do(ThreadClosure* tc) { 2857 assert_locked_or_safepoint(Threads_lock); 2858 // ALL_JAVA_THREADS iterates through all JavaThreads 2859 ALL_JAVA_THREADS(p) { 2860 tc->do_thread(p); 2861 } 2862 // Someday we could have a table or list of all non-JavaThreads. 2863 // For now, just manually iterate through them. 2864 tc->do_thread(VMThread::vm_thread()); 2865 Universe::heap()->gc_threads_do(tc); 2866 WatcherThread *wt = WatcherThread::watcher_thread(); 2867 // Strictly speaking, the following NULL check isn't sufficient to make sure 2868 // the data for WatcherThread is still valid upon being examined. However, 2869 // considering that WatchThread terminates when the VM is on the way to 2870 // exit at safepoint, the chance of the above is extremely small. The right 2871 // way to prevent termination of WatcherThread would be to acquire 2872 // Terminator_lock, but we can't do that without violating the lock rank 2873 // checking in some cases. 2874 if (wt != NULL) 2875 tc->do_thread(wt); 2876 2877 // If CompilerThreads ever become non-JavaThreads, add them here 2878} 2879 2880jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) { 2881 2882 extern void JDK_Version_init(); 2883 2884 // Check version 2885 if (!is_supported_jni_version(args->version)) return JNI_EVERSION; 2886 2887 // Initialize the output stream module 2888 ostream_init(); 2889 2890 // Process java launcher properties. 2891 Arguments::process_sun_java_launcher_properties(args); 2892 2893 // Initialize the os module before using TLS 2894 os::init(); 2895 2896 // Initialize system properties. 2897 Arguments::init_system_properties(); 2898 2899 // So that JDK version can be used as a discrimintor when parsing arguments 2900 JDK_Version_init(); 2901 2902 // Parse arguments 2903 jint parse_result = Arguments::parse(args); 2904 if (parse_result != JNI_OK) return parse_result; 2905 2906 if (PauseAtStartup) { 2907 os::pause(); 2908 } 2909 2910 HS_DTRACE_PROBE(hotspot, vm__init__begin); 2911 2912 // Record VM creation timing statistics 2913 TraceVmCreationTime create_vm_timer; 2914 create_vm_timer.start(); 2915 2916 // Timing (must come after argument parsing) 2917 TraceTime timer("Create VM", TraceStartupTime); 2918 2919 // Initialize the os module after parsing the args 2920 jint os_init_2_result = os::init_2(); 2921 if (os_init_2_result != JNI_OK) return os_init_2_result; 2922 2923 // Initialize output stream logging 2924 ostream_init_log(); 2925 2926 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad 2927 // Must be before create_vm_init_agents() 2928 if (Arguments::init_libraries_at_startup()) { 2929 convert_vm_init_libraries_to_agents(); 2930 } 2931 2932 // Launch -agentlib/-agentpath and converted -Xrun agents 2933 if (Arguments::init_agents_at_startup()) { 2934 create_vm_init_agents(); 2935 } 2936 2937 // Initialize Threads state 2938 _thread_list = NULL; 2939 _number_of_threads = 0; 2940 _number_of_non_daemon_threads = 0; 2941 2942 // Initialize TLS 2943 ThreadLocalStorage::init(); 2944 2945 // Initialize global data structures and create system classes in heap 2946 vm_init_globals(); 2947 2948 // Attach the main thread to this os thread 2949 JavaThread* main_thread = new JavaThread(); 2950 main_thread->set_thread_state(_thread_in_vm); 2951 // must do this before set_active_handles and initialize_thread_local_storage 2952 // Note: on solaris initialize_thread_local_storage() will (indirectly) 2953 // change the stack size recorded here to one based on the java thread 2954 // stacksize. This adjusted size is what is used to figure the placement 2955 // of the guard pages. 2956 main_thread->record_stack_base_and_size(); 2957 main_thread->initialize_thread_local_storage(); 2958 2959 main_thread->set_active_handles(JNIHandleBlock::allocate_block()); 2960 2961 if (!main_thread->set_as_starting_thread()) { 2962 vm_shutdown_during_initialization( 2963 "Failed necessary internal allocation. Out of swap space"); 2964 delete main_thread; 2965 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 2966 return JNI_ENOMEM; 2967 } 2968 2969 // Enable guard page *after* os::create_main_thread(), otherwise it would 2970 // crash Linux VM, see notes in os_linux.cpp. 2971 main_thread->create_stack_guard_pages(); 2972 2973 // Initialize Java-Leve synchronization subsystem 2974 ObjectSynchronizer::Initialize() ; 2975 2976 // Initialize global modules 2977 jint status = init_globals(); 2978 if (status != JNI_OK) { 2979 delete main_thread; 2980 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 2981 return status; 2982 } 2983 2984 // Should be done after the heap is fully created 2985 main_thread->cache_global_variables(); 2986 2987 HandleMark hm; 2988 2989 { MutexLocker mu(Threads_lock); 2990 Threads::add(main_thread); 2991 } 2992 2993 // Any JVMTI raw monitors entered in onload will transition into 2994 // real raw monitor. VM is setup enough here for raw monitor enter. 2995 JvmtiExport::transition_pending_onload_raw_monitors(); 2996 2997 if (VerifyBeforeGC && 2998 Universe::heap()->total_collections() >= VerifyGCStartAt) { 2999 Universe::heap()->prepare_for_verify(); 3000 Universe::verify(); // make sure we're starting with a clean slate 3001 } 3002 3003 // Create the VMThread 3004 { TraceTime timer("Start VMThread", TraceStartupTime); 3005 VMThread::create(); 3006 Thread* vmthread = VMThread::vm_thread(); 3007 3008 if (!os::create_thread(vmthread, os::vm_thread)) 3009 vm_exit_during_initialization("Cannot create VM thread. Out of system resources."); 3010 3011 // Wait for the VM thread to become ready, and VMThread::run to initialize 3012 // Monitors can have spurious returns, must always check another state flag 3013 { 3014 MutexLocker ml(Notify_lock); 3015 os::start_thread(vmthread); 3016 while (vmthread->active_handles() == NULL) { 3017 Notify_lock->wait(); 3018 } 3019 } 3020 } 3021 3022 assert (Universe::is_fully_initialized(), "not initialized"); 3023 EXCEPTION_MARK; 3024 3025 // At this point, the Universe is initialized, but we have not executed 3026 // any byte code. Now is a good time (the only time) to dump out the 3027 // internal state of the JVM for sharing. 3028 3029 if (DumpSharedSpaces) { 3030 Universe::heap()->preload_and_dump(CHECK_0); 3031 ShouldNotReachHere(); 3032 } 3033 3034 // Always call even when there are not JVMTI environments yet, since environments 3035 // may be attached late and JVMTI must track phases of VM execution 3036 JvmtiExport::enter_start_phase(); 3037 3038 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. 3039 JvmtiExport::post_vm_start(); 3040 3041 { 3042 TraceTime timer("Initialize java.lang classes", TraceStartupTime); 3043 3044 if (EagerXrunInit && Arguments::init_libraries_at_startup()) { 3045 create_vm_init_libraries(); 3046 } 3047 3048 if (InitializeJavaLangString) { 3049 initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0); 3050 } else { 3051 warning("java.lang.String not initialized"); 3052 } 3053 3054 if (AggressiveOpts) { 3055 { 3056 // Forcibly initialize java/util/HashMap and mutate the private 3057 // static final "frontCacheEnabled" field before we start creating instances 3058#ifdef ASSERT 3059 klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); 3060 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet"); 3061#endif 3062 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); 3063 KlassHandle k = KlassHandle(THREAD, k_o); 3064 guarantee(k.not_null(), "Must find java/util/HashMap"); 3065 instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); 3066 ik->initialize(CHECK_0); 3067 fieldDescriptor fd; 3068 // Possible we might not find this field; if so, don't break 3069 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { 3070 k()->bool_field_put(fd.offset(), true); 3071 } 3072 } 3073 3074 if (UseStringCache) { 3075 // Forcibly initialize java/lang/StringValue and mutate the private 3076 // static final "stringCacheEnabled" field before we start creating instances 3077 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_StringValue(), Handle(), Handle(), CHECK_0); 3078 // Possible that StringValue isn't present: if so, silently don't break 3079 if (k_o != NULL) { 3080 KlassHandle k = KlassHandle(THREAD, k_o); 3081 instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); 3082 ik->initialize(CHECK_0); 3083 fieldDescriptor fd; 3084 // Possible we might not find this field: if so, silently don't break 3085 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { 3086 k()->bool_field_put(fd.offset(), true); 3087 } 3088 } 3089 } 3090 } 3091 3092 // Initialize java_lang.System (needed before creating the thread) 3093 if (InitializeJavaLangSystem) { 3094 initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0); 3095 initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0); 3096 Handle thread_group = create_initial_thread_group(CHECK_0); 3097 Universe::set_main_thread_group(thread_group()); 3098 initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0); 3099 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0); 3100 main_thread->set_threadObj(thread_object); 3101 // Set thread status to running since main thread has 3102 // been started and running. 3103 java_lang_Thread::set_thread_status(thread_object, 3104 java_lang_Thread::RUNNABLE); 3105 3106 // The VM preresolve methods to these classes. Make sure that get initialized 3107 initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0); 3108 initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0); 3109 // The VM creates & returns objects of this class. Make sure it's initialized. 3110 initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0); 3111 call_initializeSystemClass(CHECK_0); 3112 } else { 3113 warning("java.lang.System not initialized"); 3114 } 3115 3116 // an instance of OutOfMemory exception has been allocated earlier 3117 if (InitializeJavaLangExceptionsErrors) { 3118 initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0); 3119 initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0); 3120 initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0); 3121 initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0); 3122 initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0); 3123 initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0); 3124 initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0); 3125 } else { 3126 warning("java.lang.OutOfMemoryError has not been initialized"); 3127 warning("java.lang.NullPointerException has not been initialized"); 3128 warning("java.lang.ClassCastException has not been initialized"); 3129 warning("java.lang.ArrayStoreException has not been initialized"); 3130 warning("java.lang.ArithmeticException has not been initialized"); 3131 warning("java.lang.StackOverflowError has not been initialized"); 3132 } 3133 3134 if (EnableInvokeDynamic) { 3135 // JSR 292: An intialized java.dyn.InvokeDynamic is required in 3136 // the compiler. 3137 initialize_class(vmSymbolHandles::java_dyn_InvokeDynamic(), CHECK_0); 3138 } 3139 } 3140 3141 // See : bugid 4211085. 3142 // Background : the static initializer of java.lang.Compiler tries to read 3143 // property"java.compiler" and read & write property "java.vm.info". 3144 // When a security manager is installed through the command line 3145 // option "-Djava.security.manager", the above properties are not 3146 // readable and the static initializer for java.lang.Compiler fails 3147 // resulting in a NoClassDefFoundError. This can happen in any 3148 // user code which calls methods in java.lang.Compiler. 3149 // Hack : the hack is to pre-load and initialize this class, so that only 3150 // system domains are on the stack when the properties are read. 3151 // Currently even the AWT code has calls to methods in java.lang.Compiler. 3152 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT. 3153 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and 3154 // read and write"java.vm.info" in the default policy file. See bugid 4211383 3155 // Once that is done, we should remove this hack. 3156 initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0); 3157 3158 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to 3159 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot 3160 // compiler does not get loaded through java.lang.Compiler). "java -version" with the 3161 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here. 3162 // This should also be taken out as soon as 4211383 gets fixed. 3163 reset_vm_info_property(CHECK_0); 3164 3165 quicken_jni_functions(); 3166 3167 // Set flag that basic initialization has completed. Used by exceptions and various 3168 // debug stuff, that does not work until all basic classes have been initialized. 3169 set_init_completed(); 3170 3171 HS_DTRACE_PROBE(hotspot, vm__init__end); 3172 3173 // record VM initialization completion time 3174 Management::record_vm_init_completed(); 3175 3176 // Compute system loader. Note that this has to occur after set_init_completed, since 3177 // valid exceptions may be thrown in the process. 3178 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and 3179 // set_init_completed has just been called, causing exceptions not to be shortcut 3180 // anymore. We call vm_exit_during_initialization directly instead. 3181 SystemDictionary::compute_java_system_loader(THREAD); 3182 if (HAS_PENDING_EXCEPTION) { 3183 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); 3184 } 3185 3186#ifdef KERNEL 3187 if (JDK_Version::is_gte_jdk17x_version()) { 3188 set_jkernel_boot_classloader_hook(THREAD); 3189 } 3190#endif // KERNEL 3191 3192#ifndef SERIALGC 3193 // Support for ConcurrentMarkSweep. This should be cleaned up 3194 // and better encapsulated. The ugly nested if test would go away 3195 // once things are properly refactored. XXX YSR 3196 if (UseConcMarkSweepGC || UseG1GC) { 3197 if (UseConcMarkSweepGC) { 3198 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD); 3199 } else { 3200 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD); 3201 } 3202 if (HAS_PENDING_EXCEPTION) { 3203 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); 3204 } 3205 } 3206#endif // SERIALGC 3207 3208 // Always call even when there are not JVMTI environments yet, since environments 3209 // may be attached late and JVMTI must track phases of VM execution 3210 JvmtiExport::enter_live_phase(); 3211 3212 // Signal Dispatcher needs to be started before VMInit event is posted 3213 os::signal_init(); 3214 3215 // Start Attach Listener if +StartAttachListener or it can't be started lazily 3216 if (!DisableAttachMechanism) { 3217 if (StartAttachListener || AttachListener::init_at_startup()) { 3218 AttachListener::init(); 3219 } 3220 } 3221 3222 // Launch -Xrun agents 3223 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP 3224 // back-end can launch with -Xdebug -Xrunjdwp. 3225 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) { 3226 create_vm_init_libraries(); 3227 } 3228 3229 // Notify JVMTI agents that VM initialization is complete - nop if no agents. 3230 JvmtiExport::post_vm_initialized(); 3231 3232 Chunk::start_chunk_pool_cleaner_task(); 3233 3234 // initialize compiler(s) 3235 CompileBroker::compilation_init(); 3236 3237 Management::initialize(THREAD); 3238 if (HAS_PENDING_EXCEPTION) { 3239 // management agent fails to start possibly due to 3240 // configuration problem and is responsible for printing 3241 // stack trace if appropriate. Simply exit VM. 3242 vm_exit(1); 3243 } 3244 3245 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true); 3246 if (Arguments::has_alloc_profile()) AllocationProfiler::engage(); 3247 if (MemProfiling) MemProfiler::engage(); 3248 StatSampler::engage(); 3249 if (CheckJNICalls) JniPeriodicChecker::engage(); 3250 3251 BiasedLocking::init(); 3252 3253 3254 // Start up the WatcherThread if there are any periodic tasks 3255 // NOTE: All PeriodicTasks should be registered by now. If they 3256 // aren't, late joiners might appear to start slowly (we might 3257 // take a while to process their first tick). 3258 if (PeriodicTask::num_tasks() > 0) { 3259 WatcherThread::start(); 3260 } 3261 3262 // Give os specific code one last chance to start 3263 os::init_3(); 3264 3265 create_vm_timer.end(); 3266 return JNI_OK; 3267} 3268 3269// type for the Agent_OnLoad and JVM_OnLoad entry points 3270extern "C" { 3271 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *); 3272} 3273// Find a command line agent library and return its entry point for 3274// -agentlib: -agentpath: -Xrun 3275// num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array. 3276static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) { 3277 OnLoadEntry_t on_load_entry = NULL; 3278 void *library = agent->os_lib(); // check if we have looked it up before 3279 3280 if (library == NULL) { 3281 char buffer[JVM_MAXPATHLEN]; 3282 char ebuf[1024]; 3283 const char *name = agent->name(); 3284 3285 if (agent->is_absolute_path()) { 3286 library = hpi::dll_load(name, ebuf, sizeof ebuf); 3287 if (library == NULL) { 3288 // If we can't find the agent, exit. 3289 vm_exit_during_initialization("Could not find agent library in absolute path", name); 3290 } 3291 } else { 3292 // Try to load the agent from the standard dll directory 3293 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name); 3294 library = hpi::dll_load(buffer, ebuf, sizeof ebuf); 3295#ifdef KERNEL 3296 // Download instrument dll 3297 if (library == NULL && strcmp(name, "instrument") == 0) { 3298 char *props = Arguments::get_kernel_properties(); 3299 char *home = Arguments::get_java_home(); 3300 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false" 3301 " sun.jkernel.DownloadManager -download client_jvm"; 3302 int length = strlen(props) + strlen(home) + strlen(fmt) + 1; 3303 char *cmd = AllocateHeap(length); 3304 jio_snprintf(cmd, length, fmt, home, props); 3305 int status = os::fork_and_exec(cmd); 3306 FreeHeap(props); 3307 FreeHeap(cmd); 3308 if (status == -1) { 3309 warning(cmd); 3310 vm_exit_during_initialization("fork_and_exec failed: %s", 3311 strerror(errno)); 3312 } 3313 // when this comes back the instrument.dll should be where it belongs. 3314 library = hpi::dll_load(buffer, ebuf, sizeof ebuf); 3315 } 3316#endif // KERNEL 3317 if (library == NULL) { // Try the local directory 3318 char ns[1] = {0}; 3319 hpi::dll_build_name(buffer, sizeof(buffer), ns, name); 3320 library = hpi::dll_load(buffer, ebuf, sizeof ebuf); 3321 if (library == NULL) { 3322 // If we can't find the agent, exit. 3323 vm_exit_during_initialization("Could not find agent library on the library path or in the local directory", name); 3324 } 3325 } 3326 } 3327 agent->set_os_lib(library); 3328 } 3329 3330 // Find the OnLoad function. 3331 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) { 3332 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index])); 3333 if (on_load_entry != NULL) break; 3334 } 3335 return on_load_entry; 3336} 3337 3338// Find the JVM_OnLoad entry point 3339static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) { 3340 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS; 3341 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); 3342} 3343 3344// Find the Agent_OnLoad entry point 3345static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) { 3346 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS; 3347 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); 3348} 3349 3350// For backwards compatibility with -Xrun 3351// Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be 3352// treated like -agentpath: 3353// Must be called before agent libraries are created 3354void Threads::convert_vm_init_libraries_to_agents() { 3355 AgentLibrary* agent; 3356 AgentLibrary* next; 3357 3358 for (agent = Arguments::libraries(); agent != NULL; agent = next) { 3359 next = agent->next(); // cache the next agent now as this agent may get moved off this list 3360 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); 3361 3362 // If there is an JVM_OnLoad function it will get called later, 3363 // otherwise see if there is an Agent_OnLoad 3364 if (on_load_entry == NULL) { 3365 on_load_entry = lookup_agent_on_load(agent); 3366 if (on_load_entry != NULL) { 3367 // switch it to the agent list -- so that Agent_OnLoad will be called, 3368 // JVM_OnLoad won't be attempted and Agent_OnUnload will 3369 Arguments::convert_library_to_agent(agent); 3370 } else { 3371 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name()); 3372 } 3373 } 3374 } 3375} 3376 3377// Create agents for -agentlib: -agentpath: and converted -Xrun 3378// Invokes Agent_OnLoad 3379// Called very early -- before JavaThreads exist 3380void Threads::create_vm_init_agents() { 3381 extern struct JavaVM_ main_vm; 3382 AgentLibrary* agent; 3383 3384 JvmtiExport::enter_onload_phase(); 3385 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 3386 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent); 3387 3388 if (on_load_entry != NULL) { 3389 // Invoke the Agent_OnLoad function 3390 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); 3391 if (err != JNI_OK) { 3392 vm_exit_during_initialization("agent library failed to init", agent->name()); 3393 } 3394 } else { 3395 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name()); 3396 } 3397 } 3398 JvmtiExport::enter_primordial_phase(); 3399} 3400 3401extern "C" { 3402 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *); 3403} 3404 3405void Threads::shutdown_vm_agents() { 3406 // Send any Agent_OnUnload notifications 3407 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS; 3408 extern struct JavaVM_ main_vm; 3409 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 3410 3411 // Find the Agent_OnUnload function. 3412 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) { 3413 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t, 3414 hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index])); 3415 3416 // Invoke the Agent_OnUnload function 3417 if (unload_entry != NULL) { 3418 JavaThread* thread = JavaThread::current(); 3419 ThreadToNativeFromVM ttn(thread); 3420 HandleMark hm(thread); 3421 (*unload_entry)(&main_vm); 3422 break; 3423 } 3424 } 3425 } 3426} 3427 3428// Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries 3429// Invokes JVM_OnLoad 3430void Threads::create_vm_init_libraries() { 3431 extern struct JavaVM_ main_vm; 3432 AgentLibrary* agent; 3433 3434 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) { 3435 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); 3436 3437 if (on_load_entry != NULL) { 3438 // Invoke the JVM_OnLoad function 3439 JavaThread* thread = JavaThread::current(); 3440 ThreadToNativeFromVM ttn(thread); 3441 HandleMark hm(thread); 3442 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); 3443 if (err != JNI_OK) { 3444 vm_exit_during_initialization("-Xrun library failed to init", agent->name()); 3445 } 3446 } else { 3447 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name()); 3448 } 3449 } 3450} 3451 3452// Last thread running calls java.lang.Shutdown.shutdown() 3453void JavaThread::invoke_shutdown_hooks() { 3454 HandleMark hm(this); 3455 3456 // We could get here with a pending exception, if so clear it now. 3457 if (this->has_pending_exception()) { 3458 this->clear_pending_exception(); 3459 } 3460 3461 EXCEPTION_MARK; 3462 klassOop k = 3463 SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(), 3464 THREAD); 3465 if (k != NULL) { 3466 // SystemDictionary::resolve_or_null will return null if there was 3467 // an exception. If we cannot load the Shutdown class, just don't 3468 // call Shutdown.shutdown() at all. This will mean the shutdown hooks 3469 // and finalizers (if runFinalizersOnExit is set) won't be run. 3470 // Note that if a shutdown hook was registered or runFinalizersOnExit 3471 // was called, the Shutdown class would have already been loaded 3472 // (Runtime.addShutdownHook and runFinalizersOnExit will load it). 3473 instanceKlassHandle shutdown_klass (THREAD, k); 3474 JavaValue result(T_VOID); 3475 JavaCalls::call_static(&result, 3476 shutdown_klass, 3477 vmSymbolHandles::shutdown_method_name(), 3478 vmSymbolHandles::void_method_signature(), 3479 THREAD); 3480 } 3481 CLEAR_PENDING_EXCEPTION; 3482} 3483 3484// Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when 3485// the program falls off the end of main(). Another VM exit path is through 3486// vm_exit() when the program calls System.exit() to return a value or when 3487// there is a serious error in VM. The two shutdown paths are not exactly 3488// the same, but they share Shutdown.shutdown() at Java level and before_exit() 3489// and VM_Exit op at VM level. 3490// 3491// Shutdown sequence: 3492// + Wait until we are the last non-daemon thread to execute 3493// <-- every thing is still working at this moment --> 3494// + Call java.lang.Shutdown.shutdown(), which will invoke Java level 3495// shutdown hooks, run finalizers if finalization-on-exit 3496// + Call before_exit(), prepare for VM exit 3497// > run VM level shutdown hooks (they are registered through JVM_OnExit(), 3498// currently the only user of this mechanism is File.deleteOnExit()) 3499// > stop flat profiler, StatSampler, watcher thread, CMS threads, 3500// post thread end and vm death events to JVMTI, 3501// stop signal thread 3502// + Call JavaThread::exit(), it will: 3503// > release JNI handle blocks, remove stack guard pages 3504// > remove this thread from Threads list 3505// <-- no more Java code from this thread after this point --> 3506// + Stop VM thread, it will bring the remaining VM to a safepoint and stop 3507// the compiler threads at safepoint 3508// <-- do not use anything that could get blocked by Safepoint --> 3509// + Disable tracing at JNI/JVM barriers 3510// + Set _vm_exited flag for threads that are still running native code 3511// + Delete this thread 3512// + Call exit_globals() 3513// > deletes tty 3514// > deletes PerfMemory resources 3515// + Return to caller 3516 3517bool Threads::destroy_vm() { 3518 JavaThread* thread = JavaThread::current(); 3519 3520 // Wait until we are the last non-daemon thread to execute 3521 { MutexLocker nu(Threads_lock); 3522 while (Threads::number_of_non_daemon_threads() > 1 ) 3523 // This wait should make safepoint checks, wait without a timeout, 3524 // and wait as a suspend-equivalent condition. 3525 // 3526 // Note: If the FlatProfiler is running and this thread is waiting 3527 // for another non-daemon thread to finish, then the FlatProfiler 3528 // is waiting for the external suspend request on this thread to 3529 // complete. wait_for_ext_suspend_completion() will eventually 3530 // timeout, but that takes time. Making this wait a suspend- 3531 // equivalent condition solves that timeout problem. 3532 // 3533 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0, 3534 Mutex::_as_suspend_equivalent_flag); 3535 } 3536 3537 // Hang forever on exit if we are reporting an error. 3538 if (ShowMessageBoxOnError && is_error_reported()) { 3539 os::infinite_sleep(); 3540 } 3541 3542 if (JDK_Version::is_jdk12x_version()) { 3543 // We are the last thread running, so check if finalizers should be run. 3544 // For 1.3 or later this is done in thread->invoke_shutdown_hooks() 3545 HandleMark rm(thread); 3546 Universe::run_finalizers_on_exit(); 3547 } else { 3548 // run Java level shutdown hooks 3549 thread->invoke_shutdown_hooks(); 3550 } 3551 3552 before_exit(thread); 3553 3554 thread->exit(true); 3555 3556 // Stop VM thread. 3557 { 3558 // 4945125 The vm thread comes to a safepoint during exit. 3559 // GC vm_operations can get caught at the safepoint, and the 3560 // heap is unparseable if they are caught. Grab the Heap_lock 3561 // to prevent this. The GC vm_operations will not be able to 3562 // queue until after the vm thread is dead. 3563 MutexLocker ml(Heap_lock); 3564 3565 VMThread::wait_for_vm_thread_exit(); 3566 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint"); 3567 VMThread::destroy(); 3568 } 3569 3570 // clean up ideal graph printers 3571#if defined(COMPILER2) && !defined(PRODUCT) 3572 IdealGraphPrinter::clean_up(); 3573#endif 3574 3575 // Now, all Java threads are gone except daemon threads. Daemon threads 3576 // running Java code or in VM are stopped by the Safepoint. However, 3577 // daemon threads executing native code are still running. But they 3578 // will be stopped at native=>Java/VM barriers. Note that we can't 3579 // simply kill or suspend them, as it is inherently deadlock-prone. 3580 3581#ifndef PRODUCT 3582 // disable function tracing at JNI/JVM barriers 3583 TraceHPI = false; 3584 TraceJNICalls = false; 3585 TraceJVMCalls = false; 3586 TraceRuntimeCalls = false; 3587#endif 3588 3589 VM_Exit::set_vm_exited(); 3590 3591 notify_vm_shutdown(); 3592 3593 delete thread; 3594 3595 // exit_globals() will delete tty 3596 exit_globals(); 3597 3598 return true; 3599} 3600 3601 3602jboolean Threads::is_supported_jni_version_including_1_1(jint version) { 3603 if (version == JNI_VERSION_1_1) return JNI_TRUE; 3604 return is_supported_jni_version(version); 3605} 3606 3607 3608jboolean Threads::is_supported_jni_version(jint version) { 3609 if (version == JNI_VERSION_1_2) return JNI_TRUE; 3610 if (version == JNI_VERSION_1_4) return JNI_TRUE; 3611 if (version == JNI_VERSION_1_6) return JNI_TRUE; 3612 return JNI_FALSE; 3613} 3614 3615 3616void Threads::add(JavaThread* p, bool force_daemon) { 3617 // The threads lock must be owned at this point 3618 assert_locked_or_safepoint(Threads_lock); 3619 p->set_next(_thread_list); 3620 _thread_list = p; 3621 _number_of_threads++; 3622 oop threadObj = p->threadObj(); 3623 bool daemon = true; 3624 // Bootstrapping problem: threadObj can be null for initial 3625 // JavaThread (or for threads attached via JNI) 3626 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) { 3627 _number_of_non_daemon_threads++; 3628 daemon = false; 3629 } 3630 3631 ThreadService::add_thread(p, daemon); 3632 3633 // Possible GC point. 3634 Events::log("Thread added: " INTPTR_FORMAT, p); 3635} 3636 3637void Threads::remove(JavaThread* p) { 3638 // Extra scope needed for Thread_lock, so we can check 3639 // that we do not remove thread without safepoint code notice 3640 { MutexLocker ml(Threads_lock); 3641 3642 assert(includes(p), "p must be present"); 3643 3644 JavaThread* current = _thread_list; 3645 JavaThread* prev = NULL; 3646 3647 while (current != p) { 3648 prev = current; 3649 current = current->next(); 3650 } 3651 3652 if (prev) { 3653 prev->set_next(current->next()); 3654 } else { 3655 _thread_list = p->next(); 3656 } 3657 _number_of_threads--; 3658 oop threadObj = p->threadObj(); 3659 bool daemon = true; 3660 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) { 3661 _number_of_non_daemon_threads--; 3662 daemon = false; 3663 3664 // Only one thread left, do a notify on the Threads_lock so a thread waiting 3665 // on destroy_vm will wake up. 3666 if (number_of_non_daemon_threads() == 1) 3667 Threads_lock->notify_all(); 3668 } 3669 ThreadService::remove_thread(p, daemon); 3670 3671 // Make sure that safepoint code disregard this thread. This is needed since 3672 // the thread might mess around with locks after this point. This can cause it 3673 // to do callbacks into the safepoint code. However, the safepoint code is not aware 3674 // of this thread since it is removed from the queue. 3675 p->set_terminated_value(); 3676 } // unlock Threads_lock 3677 3678 // Since Events::log uses a lock, we grab it outside the Threads_lock 3679 Events::log("Thread exited: " INTPTR_FORMAT, p); 3680} 3681 3682// Threads_lock must be held when this is called (or must be called during a safepoint) 3683bool Threads::includes(JavaThread* p) { 3684 assert(Threads_lock->is_locked(), "sanity check"); 3685 ALL_JAVA_THREADS(q) { 3686 if (q == p ) { 3687 return true; 3688 } 3689 } 3690 return false; 3691} 3692 3693// Operations on the Threads list for GC. These are not explicitly locked, 3694// but the garbage collector must provide a safe context for them to run. 3695// In particular, these things should never be called when the Threads_lock 3696// is held by some other thread. (Note: the Safepoint abstraction also 3697// uses the Threads_lock to gurantee this property. It also makes sure that 3698// all threads gets blocked when exiting or starting). 3699 3700void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) { 3701 ALL_JAVA_THREADS(p) { 3702 p->oops_do(f, cf); 3703 } 3704 VMThread::vm_thread()->oops_do(f, cf); 3705} 3706 3707void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) { 3708 // Introduce a mechanism allowing parallel threads to claim threads as 3709 // root groups. Overhead should be small enough to use all the time, 3710 // even in sequential code. 3711 SharedHeap* sh = SharedHeap::heap(); 3712 bool is_par = (sh->n_par_threads() > 0); 3713 int cp = SharedHeap::heap()->strong_roots_parity(); 3714 ALL_JAVA_THREADS(p) { 3715 if (p->claim_oops_do(is_par, cp)) { 3716 p->oops_do(f, cf); 3717 } 3718 } 3719 VMThread* vmt = VMThread::vm_thread(); 3720 if (vmt->claim_oops_do(is_par, cp)) 3721 vmt->oops_do(f, cf); 3722} 3723 3724#ifndef SERIALGC 3725// Used by ParallelScavenge 3726void Threads::create_thread_roots_tasks(GCTaskQueue* q) { 3727 ALL_JAVA_THREADS(p) { 3728 q->enqueue(new ThreadRootsTask(p)); 3729 } 3730 q->enqueue(new ThreadRootsTask(VMThread::vm_thread())); 3731} 3732 3733// Used by Parallel Old 3734void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) { 3735 ALL_JAVA_THREADS(p) { 3736 q->enqueue(new ThreadRootsMarkingTask(p)); 3737 } 3738 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread())); 3739} 3740#endif // SERIALGC 3741 3742void Threads::nmethods_do(CodeBlobClosure* cf) { 3743 ALL_JAVA_THREADS(p) { 3744 p->nmethods_do(cf); 3745 } 3746 VMThread::vm_thread()->nmethods_do(cf); 3747} 3748 3749void Threads::gc_epilogue() { 3750 ALL_JAVA_THREADS(p) { 3751 p->gc_epilogue(); 3752 } 3753} 3754 3755void Threads::gc_prologue() { 3756 ALL_JAVA_THREADS(p) { 3757 p->gc_prologue(); 3758 } 3759} 3760 3761void Threads::deoptimized_wrt_marked_nmethods() { 3762 ALL_JAVA_THREADS(p) { 3763 p->deoptimized_wrt_marked_nmethods(); 3764 } 3765} 3766 3767 3768// Get count Java threads that are waiting to enter the specified monitor. 3769GrowableArray<JavaThread*>* Threads::get_pending_threads(int count, 3770 address monitor, bool doLock) { 3771 assert(doLock || SafepointSynchronize::is_at_safepoint(), 3772 "must grab Threads_lock or be at safepoint"); 3773 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count); 3774 3775 int i = 0; 3776 { 3777 MutexLockerEx ml(doLock ? Threads_lock : NULL); 3778 ALL_JAVA_THREADS(p) { 3779 if (p->is_Compiler_thread()) continue; 3780 3781 address pending = (address)p->current_pending_monitor(); 3782 if (pending == monitor) { // found a match 3783 if (i < count) result->append(p); // save the first count matches 3784 i++; 3785 } 3786 } 3787 } 3788 return result; 3789} 3790 3791 3792JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) { 3793 assert(doLock || 3794 Threads_lock->owned_by_self() || 3795 SafepointSynchronize::is_at_safepoint(), 3796 "must grab Threads_lock or be at safepoint"); 3797 3798 // NULL owner means not locked so we can skip the search 3799 if (owner == NULL) return NULL; 3800 3801 { 3802 MutexLockerEx ml(doLock ? Threads_lock : NULL); 3803 ALL_JAVA_THREADS(p) { 3804 // first, see if owner is the address of a Java thread 3805 if (owner == (address)p) return p; 3806 } 3807 } 3808 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled"); 3809 if (UseHeavyMonitors) return NULL; 3810 3811 // 3812 // If we didn't find a matching Java thread and we didn't force use of 3813 // heavyweight monitors, then the owner is the stack address of the 3814 // Lock Word in the owning Java thread's stack. 3815 // 3816 JavaThread* the_owner = NULL; 3817 { 3818 MutexLockerEx ml(doLock ? Threads_lock : NULL); 3819 ALL_JAVA_THREADS(q) { 3820 if (q->is_lock_owned(owner)) { 3821 the_owner = q; 3822 break; 3823 } 3824 } 3825 } 3826 assert(the_owner != NULL, "Did not find owning Java thread for lock word address"); 3827 return the_owner; 3828} 3829 3830// Threads::print_on() is called at safepoint by VM_PrintThreads operation. 3831void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) { 3832 char buf[32]; 3833 st->print_cr(os::local_time_string(buf, sizeof(buf))); 3834 3835 st->print_cr("Full thread dump %s (%s %s):", 3836 Abstract_VM_Version::vm_name(), 3837 Abstract_VM_Version::vm_release(), 3838 Abstract_VM_Version::vm_info_string() 3839 ); 3840 st->cr(); 3841 3842#ifndef SERIALGC 3843 // Dump concurrent locks 3844 ConcurrentLocksDump concurrent_locks; 3845 if (print_concurrent_locks) { 3846 concurrent_locks.dump_at_safepoint(); 3847 } 3848#endif // SERIALGC 3849 3850 ALL_JAVA_THREADS(p) { 3851 ResourceMark rm; 3852 p->print_on(st); 3853 if (print_stacks) { 3854 if (internal_format) { 3855 p->trace_stack(); 3856 } else { 3857 p->print_stack_on(st); 3858 } 3859 } 3860 st->cr(); 3861#ifndef SERIALGC 3862 if (print_concurrent_locks) { 3863 concurrent_locks.print_locks_on(p, st); 3864 } 3865#endif // SERIALGC 3866 } 3867 3868 VMThread::vm_thread()->print_on(st); 3869 st->cr(); 3870 Universe::heap()->print_gc_threads_on(st); 3871 WatcherThread* wt = WatcherThread::watcher_thread(); 3872 if (wt != NULL) wt->print_on(st); 3873 st->cr(); 3874 CompileBroker::print_compiler_threads_on(st); 3875 st->flush(); 3876} 3877 3878// Threads::print_on_error() is called by fatal error handler. It's possible 3879// that VM is not at safepoint and/or current thread is inside signal handler. 3880// Don't print stack trace, as the stack may not be walkable. Don't allocate 3881// memory (even in resource area), it might deadlock the error handler. 3882void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) { 3883 bool found_current = false; 3884 st->print_cr("Java Threads: ( => current thread )"); 3885 ALL_JAVA_THREADS(thread) { 3886 bool is_current = (current == thread); 3887 found_current = found_current || is_current; 3888 3889 st->print("%s", is_current ? "=>" : " "); 3890 3891 st->print(PTR_FORMAT, thread); 3892 st->print(" "); 3893 thread->print_on_error(st, buf, buflen); 3894 st->cr(); 3895 } 3896 st->cr(); 3897 3898 st->print_cr("Other Threads:"); 3899 if (VMThread::vm_thread()) { 3900 bool is_current = (current == VMThread::vm_thread()); 3901 found_current = found_current || is_current; 3902 st->print("%s", current == VMThread::vm_thread() ? "=>" : " "); 3903 3904 st->print(PTR_FORMAT, VMThread::vm_thread()); 3905 st->print(" "); 3906 VMThread::vm_thread()->print_on_error(st, buf, buflen); 3907 st->cr(); 3908 } 3909 WatcherThread* wt = WatcherThread::watcher_thread(); 3910 if (wt != NULL) { 3911 bool is_current = (current == wt); 3912 found_current = found_current || is_current; 3913 st->print("%s", is_current ? "=>" : " "); 3914 3915 st->print(PTR_FORMAT, wt); 3916 st->print(" "); 3917 wt->print_on_error(st, buf, buflen); 3918 st->cr(); 3919 } 3920 if (!found_current) { 3921 st->cr(); 3922 st->print("=>" PTR_FORMAT " (exited) ", current); 3923 current->print_on_error(st, buf, buflen); 3924 st->cr(); 3925 } 3926} 3927 3928 3929// Lifecycle management for TSM ParkEvents. 3930// ParkEvents are type-stable (TSM). 3931// In our particular implementation they happen to be immortal. 3932// 3933// We manage concurrency on the FreeList with a CAS-based 3934// detach-modify-reattach idiom that avoids the ABA problems 3935// that would otherwise be present in a simple CAS-based 3936// push-pop implementation. (push-one and pop-all) 3937// 3938// Caveat: Allocate() and Release() may be called from threads 3939// other than the thread associated with the Event! 3940// If we need to call Allocate() when running as the thread in 3941// question then look for the PD calls to initialize native TLS. 3942// Native TLS (Win32/Linux/Solaris) can only be initialized or 3943// accessed by the associated thread. 3944// See also pd_initialize(). 3945// 3946// Note that we could defer associating a ParkEvent with a thread 3947// until the 1st time the thread calls park(). unpark() calls to 3948// an unprovisioned thread would be ignored. The first park() call 3949// for a thread would allocate and associate a ParkEvent and return 3950// immediately. 3951 3952volatile int ParkEvent::ListLock = 0 ; 3953ParkEvent * volatile ParkEvent::FreeList = NULL ; 3954 3955ParkEvent * ParkEvent::Allocate (Thread * t) { 3956 // In rare cases -- JVM_RawMonitor* operations -- we can find t == null. 3957 ParkEvent * ev ; 3958 3959 // Start by trying to recycle an existing but unassociated 3960 // ParkEvent from the global free list. 3961 for (;;) { 3962 ev = FreeList ; 3963 if (ev == NULL) break ; 3964 // 1: Detach - sequester or privatize the list 3965 // Tantamount to ev = Swap (&FreeList, NULL) 3966 if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) { 3967 continue ; 3968 } 3969 3970 // We've detached the list. The list in-hand is now 3971 // local to this thread. This thread can operate on the 3972 // list without risk of interference from other threads. 3973 // 2: Extract -- pop the 1st element from the list. 3974 ParkEvent * List = ev->FreeNext ; 3975 if (List == NULL) break ; 3976 for (;;) { 3977 // 3: Try to reattach the residual list 3978 guarantee (List != NULL, "invariant") ; 3979 ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ; 3980 if (Arv == NULL) break ; 3981 3982 // New nodes arrived. Try to detach the recent arrivals. 3983 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) { 3984 continue ; 3985 } 3986 guarantee (Arv != NULL, "invariant") ; 3987 // 4: Merge Arv into List 3988 ParkEvent * Tail = List ; 3989 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ; 3990 Tail->FreeNext = Arv ; 3991 } 3992 break ; 3993 } 3994 3995 if (ev != NULL) { 3996 guarantee (ev->AssociatedWith == NULL, "invariant") ; 3997 } else { 3998 // Do this the hard way -- materialize a new ParkEvent. 3999 // In rare cases an allocating thread might detach a long list -- 4000 // installing null into FreeList -- and then stall or be obstructed. 4001 // A 2nd thread calling Allocate() would see FreeList == null. 4002 // The list held privately by the 1st thread is unavailable to the 2nd thread. 4003 // In that case the 2nd thread would have to materialize a new ParkEvent, 4004 // even though free ParkEvents existed in the system. In this case we end up 4005 // with more ParkEvents in circulation than we need, but the race is 4006 // rare and the outcome is benign. Ideally, the # of extant ParkEvents 4007 // is equal to the maximum # of threads that existed at any one time. 4008 // Because of the race mentioned above, segments of the freelist 4009 // can be transiently inaccessible. At worst we may end up with the 4010 // # of ParkEvents in circulation slightly above the ideal. 4011 // Note that if we didn't have the TSM/immortal constraint, then 4012 // when reattaching, above, we could trim the list. 4013 ev = new ParkEvent () ; 4014 guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ; 4015 } 4016 ev->reset() ; // courtesy to caller 4017 ev->AssociatedWith = t ; // Associate ev with t 4018 ev->FreeNext = NULL ; 4019 return ev ; 4020} 4021 4022void ParkEvent::Release (ParkEvent * ev) { 4023 if (ev == NULL) return ; 4024 guarantee (ev->FreeNext == NULL , "invariant") ; 4025 ev->AssociatedWith = NULL ; 4026 for (;;) { 4027 // Push ev onto FreeList 4028 // The mechanism is "half" lock-free. 4029 ParkEvent * List = FreeList ; 4030 ev->FreeNext = List ; 4031 if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ; 4032 } 4033} 4034 4035// Override operator new and delete so we can ensure that the 4036// least significant byte of ParkEvent addresses is 0. 4037// Beware that excessive address alignment is undesirable 4038// as it can result in D$ index usage imbalance as 4039// well as bank access imbalance on Niagara-like platforms, 4040// although Niagara's hash function should help. 4041 4042void * ParkEvent::operator new (size_t sz) { 4043 return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ; 4044} 4045 4046void ParkEvent::operator delete (void * a) { 4047 // ParkEvents are type-stable and immortal ... 4048 ShouldNotReachHere(); 4049} 4050 4051 4052// 6399321 As a temporary measure we copied & modified the ParkEvent:: 4053// allocate() and release() code for use by Parkers. The Parker:: forms 4054// will eventually be removed as we consolide and shift over to ParkEvents 4055// for both builtin synchronization and JSR166 operations. 4056 4057volatile int Parker::ListLock = 0 ; 4058Parker * volatile Parker::FreeList = NULL ; 4059 4060Parker * Parker::Allocate (JavaThread * t) { 4061 guarantee (t != NULL, "invariant") ; 4062 Parker * p ; 4063 4064 // Start by trying to recycle an existing but unassociated 4065 // Parker from the global free list. 4066 for (;;) { 4067 p = FreeList ; 4068 if (p == NULL) break ; 4069 // 1: Detach 4070 // Tantamount to p = Swap (&FreeList, NULL) 4071 if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) { 4072 continue ; 4073 } 4074 4075 // We've detached the list. The list in-hand is now 4076 // local to this thread. This thread can operate on the 4077 // list without risk of interference from other threads. 4078 // 2: Extract -- pop the 1st element from the list. 4079 Parker * List = p->FreeNext ; 4080 if (List == NULL) break ; 4081 for (;;) { 4082 // 3: Try to reattach the residual list 4083 guarantee (List != NULL, "invariant") ; 4084 Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ; 4085 if (Arv == NULL) break ; 4086 4087 // New nodes arrived. Try to detach the recent arrivals. 4088 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) { 4089 continue ; 4090 } 4091 guarantee (Arv != NULL, "invariant") ; 4092 // 4: Merge Arv into List 4093 Parker * Tail = List ; 4094 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ; 4095 Tail->FreeNext = Arv ; 4096 } 4097 break ; 4098 } 4099 4100 if (p != NULL) { 4101 guarantee (p->AssociatedWith == NULL, "invariant") ; 4102 } else { 4103 // Do this the hard way -- materialize a new Parker.. 4104 // In rare cases an allocating thread might detach 4105 // a long list -- installing null into FreeList --and 4106 // then stall. Another thread calling Allocate() would see 4107 // FreeList == null and then invoke the ctor. In this case we 4108 // end up with more Parkers in circulation than we need, but 4109 // the race is rare and the outcome is benign. 4110 // Ideally, the # of extant Parkers is equal to the 4111 // maximum # of threads that existed at any one time. 4112 // Because of the race mentioned above, segments of the 4113 // freelist can be transiently inaccessible. At worst 4114 // we may end up with the # of Parkers in circulation 4115 // slightly above the ideal. 4116 p = new Parker() ; 4117 } 4118 p->AssociatedWith = t ; // Associate p with t 4119 p->FreeNext = NULL ; 4120 return p ; 4121} 4122 4123 4124void Parker::Release (Parker * p) { 4125 if (p == NULL) return ; 4126 guarantee (p->AssociatedWith != NULL, "invariant") ; 4127 guarantee (p->FreeNext == NULL , "invariant") ; 4128 p->AssociatedWith = NULL ; 4129 for (;;) { 4130 // Push p onto FreeList 4131 Parker * List = FreeList ; 4132 p->FreeNext = List ; 4133 if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ; 4134 } 4135} 4136 4137void Threads::verify() { 4138 ALL_JAVA_THREADS(p) { 4139 p->verify(); 4140 } 4141 VMThread* thread = VMThread::vm_thread(); 4142 if (thread != NULL) thread->verify(); 4143} 4144