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 32 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin); 33 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end); 34 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t, 35 intptr_t, intptr_t, bool); 36 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t, 37 intptr_t, intptr_t, bool); 38 39 #define DTRACE_THREAD_PROBE(probe, javathread) \ 40 { \ 41 ResourceMark rm(this); \ 42 int len = 0; \ 43 const char* name = (javathread)->get_thread_name(); \ 44 len = strlen(name); \ 45 HS_DTRACE_PROBE5(hotspot, thread__##probe, \ 46 name, len, \ 47 java_lang_Thread::thread_id((javathread)->threadObj()), \ 48 (javathread)->osthread()->thread_id(), \ 49 java_lang_Thread::is_daemon((javathread)->threadObj())); \ 50 } 51 52 #else // ndef DTRACE_ENABLED 53 54 #define DTRACE_THREAD_PROBE(probe, javathread) 55 56 #endif // ndef DTRACE_ENABLED 57 58 // Class hierarchy 59 // - Thread 60 // - VMThread 61 // - WatcherThread 62 // - ConcurrentMarkSweepThread 63 // - JavaThread 64 // - CompilerThread 65 66 // ======= Thread ======== 67 68 // Support for forcing alignment of thread objects for biased locking 69 void* Thread::operator new(size_t size) { 70 if (UseBiasedLocking) { 71 const int alignment = markOopDesc::biased_lock_alignment; 72 size_t aligned_size = size + (alignment - sizeof(intptr_t)); 73 void* real_malloc_addr = CHeapObj::operator new(aligned_size); 74 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment); 75 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <= 76 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size), 77 "JavaThread alignment code overflowed allocated storage"); 78 if (TraceBiasedLocking) { 79 if (aligned_addr != real_malloc_addr) 80 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT, 81 real_malloc_addr, aligned_addr); 82 } 83 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr; 84 return aligned_addr; 85 } else { 86 return CHeapObj::operator new(size); 87 } 88 } 89 90 void Thread::operator delete(void* p) { 91 if (UseBiasedLocking) { 92 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address; 93 CHeapObj::operator delete(real_malloc_addr); 94 } else { 95 CHeapObj::operator delete(p); 96 } 97 } 98 99 100 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread, 101 // JavaThread 102 103 104 Thread::Thread() { 105 // stack 106 _stack_base = NULL; 107 _stack_size = 0; 108 _self_raw_id = 0; 109 _lgrp_id = -1; 110 _osthread = NULL; 111 112 // allocated data structures 113 set_resource_area(new ResourceArea()); 114 set_handle_area(new HandleArea(NULL)); 115 set_active_handles(NULL); 116 set_free_handle_block(NULL); 117 set_last_handle_mark(NULL); 118 set_osthread(NULL); 119 120 // This initial value ==> never claimed. 121 _oops_do_parity = 0; 122 123 // the handle mark links itself to last_handle_mark 124 new HandleMark(this); 125 126 // plain initialization 127 debug_only(_owned_locks = NULL;) 128 debug_only(_allow_allocation_count = 0;) 129 NOT_PRODUCT(_allow_safepoint_count = 0;) 130 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 ; 142 143 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true); 144 _suspend_flags = 0; 145 146 // thread-specific hashCode stream generator state - Marsaglia shift-xor form 147 _hashStateX = os::random() ; 148 _hashStateY = 842502087 ; 149 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ; 150 _hashStateW = 273326509 ; 151 152 _OnTrap = 0 ; 153 _schedctl = NULL ; 154 _Stalled = 0 ; 155 _TypeTag = 0x2BAD ; 156 157 // Many of the following fields are effectively final - immutable 158 // Note that nascent threads can't use the Native Monitor-Mutex 159 // construct until the _MutexEvent is initialized ... 160 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents 161 // we might instead use a stack of ParkEvents that we could provision on-demand. 162 // The stack would act as a cache to avoid calls to ParkEvent::Allocate() 163 // and ::Release() 164 _ParkEvent = ParkEvent::Allocate (this) ; 165 _SleepEvent = ParkEvent::Allocate (this) ; 166 _MutexEvent = ParkEvent::Allocate (this) ; 167 _MuxEvent = ParkEvent::Allocate (this) ; 168 169 #ifdef CHECK_UNHANDLED_OOPS 170 if (CheckUnhandledOops) { 171 _unhandled_oops = new UnhandledOops(this); 172 } 173 #endif // CHECK_UNHANDLED_OOPS 174 #ifdef ASSERT 175 if (UseBiasedLocking) { 176 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed"); 177 assert(this == _real_malloc_address || 178 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment), 179 "bug in forced alignment of thread objects"); 180 } 181 #endif /* ASSERT */ 182 } 183 184 void Thread::initialize_thread_local_storage() { 185 // Note: Make sure this method only calls 186 // non-blocking operations. Otherwise, it might not work 187 // with the thread-startup/safepoint interaction. 188 189 // During Java thread startup, safepoint code should allow this 190 // method to complete because it may need to allocate memory to 191 // store information for the new thread. 192 193 // initialize structure dependent on thread local storage 194 ThreadLocalStorage::set_thread(this); 195 196 // set up any platform-specific state. 197 os::initialize_thread(); 198 199 } 200 201 void Thread::record_stack_base_and_size() { 202 set_stack_base(os::current_stack_base()); 203 set_stack_size(os::current_stack_size()); 204 } 205 206 207 Thread::~Thread() { 208 // Reclaim the objectmonitors from the omFreeList of the moribund thread. 209 ObjectSynchronizer::omFlush (this) ; 210 211 // deallocate data structures 212 delete resource_area(); 213 // since the handle marks are using the handle area, we have to deallocated the root 214 // handle mark before deallocating the thread's handle area, 215 assert(last_handle_mark() != NULL, "check we have an element"); 216 delete last_handle_mark(); 217 assert(last_handle_mark() == NULL, "check we have reached the end"); 218 219 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads. 220 // We NULL out the fields for good hygiene. 221 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ; 222 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ; 223 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ; 224 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ; 225 226 delete handle_area(); 227 228 // osthread() can be NULL, if creation of thread failed. 229 if (osthread() != NULL) os::free_thread(osthread()); 230 231 delete _SR_lock; 232 233 // clear thread local storage if the Thread is deleting itself 234 if (this == Thread::current()) { 235 ThreadLocalStorage::set_thread(NULL); 236 } else { 237 // In the case where we're not the current thread, invalidate all the 238 // caches in case some code tries to get the current thread or the 239 // thread that was destroyed, and gets stale information. 240 ThreadLocalStorage::invalidate_all(); 241 } 242 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();) 243 } 244 245 // NOTE: dummy function for assertion purpose. 246 void Thread::run() { 247 ShouldNotReachHere(); 248 } 249 250 #ifdef ASSERT 251 // Private method to check for dangling thread pointer 252 void check_for_dangling_thread_pointer(Thread *thread) { 253 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(), 254 "possibility of dangling Thread pointer"); 255 } 256 #endif 257 258 259 #ifndef PRODUCT 260 // Tracing method for basic thread operations 261 void Thread::trace(const char* msg, const Thread* const thread) { 262 if (!TraceThreadEvents) return; 263 ResourceMark rm; 264 ThreadCritical tc; 265 const char *name = "non-Java thread"; 266 int prio = -1; 267 if (thread->is_Java_thread() 268 && !thread->is_Compiler_thread()) { 269 // The Threads_lock must be held to get information about 270 // this thread but may not be in some situations when 271 // tracing thread events. 272 bool release_Threads_lock = false; 273 if (!Threads_lock->owned_by_self()) { 274 Threads_lock->lock(); 275 release_Threads_lock = true; 276 } 277 JavaThread* jt = (JavaThread *)thread; 278 name = (char *)jt->get_thread_name(); 279 oop thread_oop = jt->threadObj(); 280 if (thread_oop != NULL) { 281 prio = java_lang_Thread::priority(thread_oop); 282 } 283 if (release_Threads_lock) { 284 Threads_lock->unlock(); 285 } 286 } 287 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio); 288 } 289 #endif 290 291 292 ThreadPriority Thread::get_priority(const Thread* const thread) { 293 trace("get priority", thread); 294 ThreadPriority priority; 295 // Can return an error! 296 (void)os::get_priority(thread, priority); 297 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found"); 298 return priority; 299 } 300 301 void Thread::set_priority(Thread* thread, ThreadPriority priority) { 302 trace("set priority", thread); 303 debug_only(check_for_dangling_thread_pointer(thread);) 304 // Can return an error! 305 (void)os::set_priority(thread, priority); 306 } 307 308 309 void Thread::start(Thread* thread) { 310 trace("start", thread); 311 // Start is different from resume in that its safety is guaranteed by context or 312 // being called from a Java method synchronized on the Thread object. 313 if (!DisableStartThread) { 314 if (thread->is_Java_thread()) { 315 // Initialize the thread state to RUNNABLE before starting this thread. 316 // Can not set it after the thread started because we do not know the 317 // exact thread state at that time. It could be in MONITOR_WAIT or 318 // in SLEEPING or some other state. 319 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(), 320 java_lang_Thread::RUNNABLE); 321 } 322 os::start_thread(thread); 323 } 324 } 325 326 // Enqueue a VM_Operation to do the job for us - sometime later 327 void Thread::send_async_exception(oop java_thread, oop java_throwable) { 328 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable); 329 VMThread::execute(vm_stop); 330 } 331 332 333 // 334 // Check if an external suspend request has completed (or has been 335 // cancelled). Returns true if the thread is externally suspended and 336 // false otherwise. 337 // 338 // The bits parameter returns information about the code path through 339 // the routine. Useful for debugging: 340 // 341 // set in is_ext_suspend_completed(): 342 // 0x00000001 - routine was entered 343 // 0x00000010 - routine return false at end 344 // 0x00000100 - thread exited (return false) 345 // 0x00000200 - suspend request cancelled (return false) 346 // 0x00000400 - thread suspended (return true) 347 // 0x00001000 - thread is in a suspend equivalent state (return true) 348 // 0x00002000 - thread is native and walkable (return true) 349 // 0x00004000 - thread is native_trans and walkable (needed retry) 350 // 351 // set in wait_for_ext_suspend_completion(): 352 // 0x00010000 - routine was entered 353 // 0x00020000 - suspend request cancelled before loop (return false) 354 // 0x00040000 - thread suspended before loop (return true) 355 // 0x00080000 - suspend request cancelled in loop (return false) 356 // 0x00100000 - thread suspended in loop (return true) 357 // 0x00200000 - suspend not completed during retry loop (return false) 358 // 359 360 // Helper class for tracing suspend wait debug bits. 361 // 362 // 0x00000100 indicates that the target thread exited before it could 363 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and 364 // 0x00080000 each indicate a cancelled suspend request so they don't 365 // count as wait failures either. 366 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000) 367 368 class TraceSuspendDebugBits : public StackObj { 369 private: 370 JavaThread * jt; 371 bool is_wait; 372 bool called_by_wait; // meaningful when !is_wait 373 uint32_t * bits; 374 375 public: 376 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait, 377 uint32_t *_bits) { 378 jt = _jt; 379 is_wait = _is_wait; 380 called_by_wait = _called_by_wait; 381 bits = _bits; 382 } 383 384 ~TraceSuspendDebugBits() { 385 if (!is_wait) { 386 #if 1 387 // By default, don't trace bits for is_ext_suspend_completed() calls. 388 // That trace is very chatty. 389 return; 390 #else 391 if (!called_by_wait) { 392 // If tracing for is_ext_suspend_completed() is enabled, then only 393 // trace calls to it from wait_for_ext_suspend_completion() 394 return; 395 } 396 #endif 397 } 398 399 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) { 400 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) { 401 MutexLocker ml(Threads_lock); // needed for get_thread_name() 402 ResourceMark rm; 403 404 tty->print_cr( 405 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)", 406 jt->get_thread_name(), *bits); 407 408 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed"); 409 } 410 } 411 } 412 }; 413 #undef DEBUG_FALSE_BITS 414 415 416 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) { 417 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits); 418 419 bool did_trans_retry = false; // only do thread_in_native_trans retry once 420 bool do_trans_retry; // flag to force the retry 421 422 *bits |= 0x00000001; 423 424 do { 425 do_trans_retry = false; 426 427 if (is_exiting()) { 428 // Thread is in the process of exiting. This is always checked 429 // first to reduce the risk of dereferencing a freed JavaThread. 430 *bits |= 0x00000100; 431 return false; 432 } 433 434 if (!is_external_suspend()) { 435 // Suspend request is cancelled. This is always checked before 436 // is_ext_suspended() to reduce the risk of a rogue resume 437 // confusing the thread that made the suspend request. 438 *bits |= 0x00000200; 439 return false; 440 } 441 442 if (is_ext_suspended()) { 443 // thread is suspended 444 *bits |= 0x00000400; 445 return true; 446 } 447 448 // Now that we no longer do hard suspends of threads running 449 // native code, the target thread can be changing thread state 450 // while we are in this routine: 451 // 452 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked 453 // 454 // We save a copy of the thread state as observed at this moment 455 // and make our decision about suspend completeness based on the 456 // copy. This closes the race where the thread state is seen as 457 // _thread_in_native_trans in the if-thread_blocked check, but is 458 // seen as _thread_blocked in if-thread_in_native_trans check. 459 JavaThreadState save_state = thread_state(); 460 461 if (save_state == _thread_blocked && is_suspend_equivalent()) { 462 // If the thread's state is _thread_blocked and this blocking 463 // condition is known to be equivalent to a suspend, then we can 464 // consider the thread to be externally suspended. This means that 465 // the code that sets _thread_blocked has been modified to do 466 // self-suspension if the blocking condition releases. We also 467 // used to check for CONDVAR_WAIT here, but that is now covered by 468 // the _thread_blocked with self-suspension check. 469 // 470 // Return true since we wouldn't be here unless there was still an 471 // external suspend request. 472 *bits |= 0x00001000; 473 return true; 474 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) { 475 // Threads running native code will self-suspend on native==>VM/Java 476 // transitions. If its stack is walkable (should always be the case 477 // unless this function is called before the actual java_suspend() 478 // call), then the wait is done. 479 *bits |= 0x00002000; 480 return true; 481 } else if (!called_by_wait && !did_trans_retry && 482 save_state == _thread_in_native_trans && 483 frame_anchor()->walkable()) { 484 // The thread is transitioning from thread_in_native to another 485 // thread state. check_safepoint_and_suspend_for_native_trans() 486 // will force the thread to self-suspend. If it hasn't gotten 487 // there yet we may have caught the thread in-between the native 488 // code check above and the self-suspend. Lucky us. If we were 489 // called by wait_for_ext_suspend_completion(), then it 490 // will be doing the retries so we don't have to. 491 // 492 // Since we use the saved thread state in the if-statement above, 493 // there is a chance that the thread has already transitioned to 494 // _thread_blocked by the time we get here. In that case, we will 495 // make a single unnecessary pass through the logic below. This 496 // doesn't hurt anything since we still do the trans retry. 497 498 *bits |= 0x00004000; 499 500 // Once the thread leaves thread_in_native_trans for another 501 // thread state, we break out of this retry loop. We shouldn't 502 // need this flag to prevent us from getting back here, but 503 // sometimes paranoia is good. 504 did_trans_retry = true; 505 506 // We wait for the thread to transition to a more usable state. 507 for (int i = 1; i <= SuspendRetryCount; i++) { 508 // We used to do an "os::yield_all(i)" call here with the intention 509 // that yielding would increase on each retry. However, the parameter 510 // is ignored on Linux which means the yield didn't scale up. Waiting 511 // on the SR_lock below provides a much more predictable scale up for 512 // the delay. It also provides a simple/direct point to check for any 513 // safepoint requests from the VMThread 514 515 // temporarily drops SR_lock while doing wait with safepoint check 516 // (if we're a JavaThread - the WatcherThread can also call this) 517 // and increase delay with each retry 518 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); 519 520 // check the actual thread state instead of what we saved above 521 if (thread_state() != _thread_in_native_trans) { 522 // the thread has transitioned to another thread state so 523 // try all the checks (except this one) one more time. 524 do_trans_retry = true; 525 break; 526 } 527 } // end retry loop 528 529 530 } 531 } while (do_trans_retry); 532 533 *bits |= 0x00000010; 534 return false; 535 } 536 537 // 538 // Wait for an external suspend request to complete (or be cancelled). 539 // Returns true if the thread is externally suspended and false otherwise. 540 // 541 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay, 542 uint32_t *bits) { 543 TraceSuspendDebugBits tsdb(this, true /* is_wait */, 544 false /* !called_by_wait */, bits); 545 546 // local flag copies to minimize SR_lock hold time 547 bool is_suspended; 548 bool pending; 549 uint32_t reset_bits; 550 551 // set a marker so is_ext_suspend_completed() knows we are the caller 552 *bits |= 0x00010000; 553 554 // We use reset_bits to reinitialize the bits value at the top of 555 // each retry loop. This allows the caller to make use of any 556 // unused bits for their own marking purposes. 557 reset_bits = *bits; 558 559 { 560 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 561 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, 562 delay, bits); 563 pending = is_external_suspend(); 564 } 565 // must release SR_lock to allow suspension to complete 566 567 if (!pending) { 568 // A cancelled suspend request is the only false return from 569 // is_ext_suspend_completed() that keeps us from entering the 570 // retry loop. 571 *bits |= 0x00020000; 572 return false; 573 } 574 575 if (is_suspended) { 576 *bits |= 0x00040000; 577 return true; 578 } 579 580 for (int i = 1; i <= retries; i++) { 581 *bits = reset_bits; // reinit to only track last retry 582 583 // We used to do an "os::yield_all(i)" call here with the intention 584 // that yielding would increase on each retry. However, the parameter 585 // is ignored on Linux which means the yield didn't scale up. Waiting 586 // on the SR_lock below provides a much more predictable scale up for 587 // the delay. It also provides a simple/direct point to check for any 588 // safepoint requests from the VMThread 589 590 { 591 MutexLocker ml(SR_lock()); 592 // wait with safepoint check (if we're a JavaThread - the WatcherThread 593 // can also call this) and increase delay with each retry 594 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); 595 596 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, 597 delay, bits); 598 599 // It is possible for the external suspend request to be cancelled 600 // (by a resume) before the actual suspend operation is completed. 601 // Refresh our local copy to see if we still need to wait. 602 pending = is_external_suspend(); 603 } 604 605 if (!pending) { 606 // A cancelled suspend request is the only false return from 607 // is_ext_suspend_completed() that keeps us from staying in the 608 // retry loop. 609 *bits |= 0x00080000; 610 return false; 611 } 612 613 if (is_suspended) { 614 *bits |= 0x00100000; 615 return true; 616 } 617 } // end retry loop 618 619 // thread did not suspend after all our retries 620 *bits |= 0x00200000; 621 return false; 622 } 623 624 #ifndef PRODUCT 625 void JavaThread::record_jump(address target, address instr, const char* file, int line) { 626 627 // This should not need to be atomic as the only way for simultaneous 628 // updates is via interrupts. Even then this should be rare or non-existant 629 // and we don't care that much anyway. 630 631 int index = _jmp_ring_index; 632 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1); 633 _jmp_ring[index]._target = (intptr_t) target; 634 _jmp_ring[index]._instruction = (intptr_t) instr; 635 _jmp_ring[index]._file = file; 636 _jmp_ring[index]._line = line; 637 } 638 #endif /* PRODUCT */ 639 640 // Called by flat profiler 641 // Callers have already called wait_for_ext_suspend_completion 642 // The assertion for that is currently too complex to put here: 643 bool JavaThread::profile_last_Java_frame(frame* _fr) { 644 bool gotframe = false; 645 // self suspension saves needed state. 646 if (has_last_Java_frame() && _anchor.walkable()) { 647 *_fr = pd_last_frame(); 648 gotframe = true; 649 } 650 return gotframe; 651 } 652 653 void Thread::interrupt(Thread* thread) { 654 trace("interrupt", thread); 655 debug_only(check_for_dangling_thread_pointer(thread);) 656 os::interrupt(thread); 657 } 658 659 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) { 660 trace("is_interrupted", thread); 661 debug_only(check_for_dangling_thread_pointer(thread);) 662 // Note: If clear_interrupted==false, this simply fetches and 663 // returns the value of the field osthread()->interrupted(). 664 return os::is_interrupted(thread, clear_interrupted); 665 } 666 667 668 // GC Support 669 bool Thread::claim_oops_do_par_case(int strong_roots_parity) { 670 jint thread_parity = _oops_do_parity; 671 if (thread_parity != strong_roots_parity) { 672 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity); 673 if (res == thread_parity) return true; 674 else { 675 guarantee(res == strong_roots_parity, "Or else what?"); 676 assert(SharedHeap::heap()->n_par_threads() > 0, 677 "Should only fail when parallel."); 678 return false; 679 } 680 } 681 assert(SharedHeap::heap()->n_par_threads() > 0, 682 "Should only fail when parallel."); 683 return false; 684 } 685 686 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) { 687 active_handles()->oops_do(f); 688 // Do oop for ThreadShadow 689 f->do_oop((oop*)&_pending_exception); 690 handle_area()->oops_do(f); 691 } 692 693 void Thread::nmethods_do(CodeBlobClosure* cf) { 694 // no nmethods in a generic thread... 695 } 696 697 void Thread::print_on(outputStream* st) const { 698 // get_priority assumes osthread initialized 699 if (osthread() != NULL) { 700 st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this); 701 osthread()->print_on(st); 702 } 703 debug_only(if (WizardMode) print_owned_locks_on(st);) 704 } 705 706 // Thread::print_on_error() is called by fatal error handler. Don't use 707 // any lock or allocate memory. 708 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const { 709 if (is_VM_thread()) st->print("VMThread"); 710 else if (is_Compiler_thread()) st->print("CompilerThread"); 711 else if (is_Java_thread()) st->print("JavaThread"); 712 else if (is_GC_task_thread()) st->print("GCTaskThread"); 713 else if (is_Watcher_thread()) st->print("WatcherThread"); 714 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread"); 715 else st->print("Thread"); 716 717 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]", 718 _stack_base - _stack_size, _stack_base); 719 720 if (osthread()) { 721 st->print(" [id=%d]", osthread()->thread_id()); 722 } 723 } 724 725 #ifdef ASSERT 726 void Thread::print_owned_locks_on(outputStream* st) const { 727 Monitor *cur = _owned_locks; 728 if (cur == NULL) { 729 st->print(" (no locks) "); 730 } else { 731 st->print_cr(" Locks owned:"); 732 while(cur) { 733 cur->print_on(st); 734 cur = cur->next(); 735 } 736 } 737 } 738 739 static int ref_use_count = 0; 740 741 bool Thread::owns_locks_but_compiled_lock() const { 742 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { 743 if (cur != Compile_lock) return true; 744 } 745 return false; 746 } 747 748 749 #endif 750 751 #ifndef PRODUCT 752 753 // The flag: potential_vm_operation notifies if this particular safepoint state could potential 754 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that 755 // no threads which allow_vm_block's are held 756 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) { 757 // Check if current thread is allowed to block at a safepoint 758 if (!(_allow_safepoint_count == 0)) 759 fatal("Possible safepoint reached by thread that does not allow it"); 760 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) { 761 fatal("LEAF method calling lock?"); 762 } 763 764 #ifdef ASSERT 765 if (potential_vm_operation && is_Java_thread() 766 && !Universe::is_bootstrapping()) { 767 // Make sure we do not hold any locks that the VM thread also uses. 768 // This could potentially lead to deadlocks 769 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { 770 // Threads_lock is special, since the safepoint synchronization will not start before this is 771 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock, 772 // since it is used to transfer control between JavaThreads and the VMThread 773 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first! 774 if ( (cur->allow_vm_block() && 775 cur != Threads_lock && 776 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation 777 cur != VMOperationRequest_lock && 778 cur != VMOperationQueue_lock) || 779 cur->rank() == Mutex::special) { 780 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name()); 781 } 782 } 783 } 784 785 if (GCALotAtAllSafepoints) { 786 // We could enter a safepoint here and thus have a gc 787 InterfaceSupport::check_gc_alot(); 788 } 789 #endif 790 } 791 #endif 792 793 bool Thread::is_in_stack(address adr) const { 794 assert(Thread::current() == this, "is_in_stack can only be called from current thread"); 795 address end = os::current_stack_pointer(); 796 if (stack_base() >= adr && adr >= end) return true; 797 798 return false; 799 } 800 801 802 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter 803 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being 804 // used for compilation in the future. If that change is made, the need for these methods 805 // should be revisited, and they should be removed if possible. 806 807 bool Thread::is_lock_owned(address adr) const { 808 return (_stack_base >= adr && adr >= (_stack_base - _stack_size)); 809 } 810 811 bool Thread::set_as_starting_thread() { 812 // NOTE: this must be called inside the main thread. 813 return os::create_main_thread((JavaThread*)this); 814 } 815 816 static void initialize_class(symbolHandle class_name, TRAPS) { 817 klassOop klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK); 818 instanceKlass::cast(klass)->initialize(CHECK); 819 } 820 821 822 // Creates the initial ThreadGroup 823 static Handle create_initial_thread_group(TRAPS) { 824 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH); 825 instanceKlassHandle klass (THREAD, k); 826 827 Handle system_instance = klass->allocate_instance_handle(CHECK_NH); 828 { 829 JavaValue result(T_VOID); 830 JavaCalls::call_special(&result, 831 system_instance, 832 klass, 833 vmSymbolHandles::object_initializer_name(), 834 vmSymbolHandles::void_method_signature(), 835 CHECK_NH); 836 } 837 Universe::set_system_thread_group(system_instance()); 838 839 Handle main_instance = klass->allocate_instance_handle(CHECK_NH); 840 { 841 JavaValue result(T_VOID); 842 Handle string = java_lang_String::create_from_str("main", CHECK_NH); 843 JavaCalls::call_special(&result, 844 main_instance, 845 klass, 846 vmSymbolHandles::object_initializer_name(), 847 vmSymbolHandles::threadgroup_string_void_signature(), 848 system_instance, 849 string, 850 CHECK_NH); 851 } 852 return main_instance; 853 } 854 855 // Creates the initial Thread 856 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) { 857 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL); 858 instanceKlassHandle klass (THREAD, k); 859 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL); 860 861 java_lang_Thread::set_thread(thread_oop(), thread); 862 java_lang_Thread::set_priority(thread_oop(), NormPriority); 863 thread->set_threadObj(thread_oop()); 864 865 Handle string = java_lang_String::create_from_str("main", CHECK_NULL); 866 867 JavaValue result(T_VOID); 868 JavaCalls::call_special(&result, thread_oop, 869 klass, 870 vmSymbolHandles::object_initializer_name(), 871 vmSymbolHandles::threadgroup_string_void_signature(), 872 thread_group, 873 string, 874 CHECK_NULL); 875 return thread_oop(); 876 } 877 878 static void call_initializeSystemClass(TRAPS) { 879 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK); 880 instanceKlassHandle klass (THREAD, k); 881 882 JavaValue result(T_VOID); 883 JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(), 884 vmSymbolHandles::void_method_signature(), CHECK); 885 } 886 887 #ifdef KERNEL 888 static void set_jkernel_boot_classloader_hook(TRAPS) { 889 klassOop k = SystemDictionary::sun_jkernel_DownloadManager_klass(); 890 instanceKlassHandle klass (THREAD, k); 891 892 if (k == NULL) { 893 // sun.jkernel.DownloadManager may not present in the JDK; just return 894 return; 895 } 896 897 JavaValue result(T_VOID); 898 JavaCalls::call_static(&result, klass, vmSymbolHandles::setBootClassLoaderHook_name(), 899 vmSymbolHandles::void_method_signature(), CHECK); 900 } 901 #endif // KERNEL 902 903 static void reset_vm_info_property(TRAPS) { 904 // the vm info string 905 ResourceMark rm(THREAD); 906 const char *vm_info = VM_Version::vm_info_string(); 907 908 // java.lang.System class 909 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK); 910 instanceKlassHandle klass (THREAD, k); 911 912 // setProperty arguments 913 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK); 914 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK); 915 916 // return value 917 JavaValue r(T_OBJECT); 918 919 // public static String setProperty(String key, String value); 920 JavaCalls::call_static(&r, 921 klass, 922 vmSymbolHandles::setProperty_name(), 923 vmSymbolHandles::string_string_string_signature(), 924 key_str, 925 value_str, 926 CHECK); 927 } 928 929 930 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) { 931 assert(thread_group.not_null(), "thread group should be specified"); 932 assert(threadObj() == NULL, "should only create Java thread object once"); 933 934 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK); 935 instanceKlassHandle klass (THREAD, k); 936 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); 937 938 java_lang_Thread::set_thread(thread_oop(), this); 939 java_lang_Thread::set_priority(thread_oop(), NormPriority); 940 set_threadObj(thread_oop()); 941 942 JavaValue result(T_VOID); 943 if (thread_name != NULL) { 944 Handle name = java_lang_String::create_from_str(thread_name, CHECK); 945 // Thread gets assigned specified name and null target 946 JavaCalls::call_special(&result, 947 thread_oop, 948 klass, 949 vmSymbolHandles::object_initializer_name(), 950 vmSymbolHandles::threadgroup_string_void_signature(), 951 thread_group, // Argument 1 952 name, // Argument 2 953 THREAD); 954 } else { 955 // Thread gets assigned name "Thread-nnn" and null target 956 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) 957 JavaCalls::call_special(&result, 958 thread_oop, 959 klass, 960 vmSymbolHandles::object_initializer_name(), 961 vmSymbolHandles::threadgroup_runnable_void_signature(), 962 thread_group, // Argument 1 963 Handle(), // Argument 2 964 THREAD); 965 } 966 967 968 if (daemon) { 969 java_lang_Thread::set_daemon(thread_oop()); 970 } 971 972 if (HAS_PENDING_EXCEPTION) { 973 return; 974 } 975 976 KlassHandle group(this, SystemDictionary::ThreadGroup_klass()); 977 Handle threadObj(this, this->threadObj()); 978 979 JavaCalls::call_special(&result, 980 thread_group, 981 group, 982 vmSymbolHandles::add_method_name(), 983 vmSymbolHandles::thread_void_signature(), 984 threadObj, // Arg 1 985 THREAD); 986 987 988 } 989 990 // NamedThread -- non-JavaThread subclasses with multiple 991 // uniquely named instances should derive from this. 992 NamedThread::NamedThread() : Thread() { 993 _name = NULL; 994 _processed_thread = NULL; 995 } 996 997 NamedThread::~NamedThread() { 998 if (_name != NULL) { 999 FREE_C_HEAP_ARRAY(char, _name); 1000 _name = NULL; 1001 } 1002 } 1003 1004 void NamedThread::set_name(const char* format, ...) { 1005 guarantee(_name == NULL, "Only get to set name once."); 1006 _name = NEW_C_HEAP_ARRAY(char, max_name_len); 1007 guarantee(_name != NULL, "alloc failure"); 1008 va_list ap; 1009 va_start(ap, format); 1010 jio_vsnprintf(_name, max_name_len, format, ap); 1011 va_end(ap); 1012 } 1013 1014 // ======= WatcherThread ======== 1015 1016 // The watcher thread exists to simulate timer interrupts. It should 1017 // be replaced by an abstraction over whatever native support for 1018 // timer interrupts exists on the platform. 1019 1020 WatcherThread* WatcherThread::_watcher_thread = NULL; 1021 bool WatcherThread::_should_terminate = false; 1022 1023 WatcherThread::WatcherThread() : Thread() { 1024 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread"); 1025 if (os::create_thread(this, os::watcher_thread)) { 1026 _watcher_thread = this; 1027 1028 // Set the watcher thread to the highest OS priority which should not be 1029 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY 1030 // is created. The only normal thread using this priority is the reference 1031 // handler thread, which runs for very short intervals only. 1032 // If the VMThread's priority is not lower than the WatcherThread profiling 1033 // will be inaccurate. 1034 os::set_priority(this, MaxPriority); 1035 if (!DisableStartThread) { 1036 os::start_thread(this); 1037 } 1038 } 1039 } 1040 1041 void WatcherThread::run() { 1042 assert(this == watcher_thread(), "just checking"); 1043 1044 this->record_stack_base_and_size(); 1045 this->initialize_thread_local_storage(); 1046 this->set_active_handles(JNIHandleBlock::allocate_block()); 1047 while(!_should_terminate) { 1048 assert(watcher_thread() == Thread::current(), "thread consistency check"); 1049 assert(watcher_thread() == this, "thread consistency check"); 1050 1051 // Calculate how long it'll be until the next PeriodicTask work 1052 // should be done, and sleep that amount of time. 1053 const size_t time_to_wait = PeriodicTask::time_to_wait(); 1054 os::sleep(this, time_to_wait, false); 1055 1056 if (is_error_reported()) { 1057 // A fatal error has happened, the error handler(VMError::report_and_die) 1058 // should abort JVM after creating an error log file. However in some 1059 // rare cases, the error handler itself might deadlock. Here we try to 1060 // kill JVM if the fatal error handler fails to abort in 2 minutes. 1061 // 1062 // This code is in WatcherThread because WatcherThread wakes up 1063 // periodically so the fatal error handler doesn't need to do anything; 1064 // also because the WatcherThread is less likely to crash than other 1065 // threads. 1066 1067 for (;;) { 1068 if (!ShowMessageBoxOnError 1069 && (OnError == NULL || OnError[0] == '\0') 1070 && Arguments::abort_hook() == NULL) { 1071 os::sleep(this, 2 * 60 * 1000, false); 1072 fdStream err(defaultStream::output_fd()); 1073 err.print_raw_cr("# [ timer expired, abort... ]"); 1074 // skip atexit/vm_exit/vm_abort hooks 1075 os::die(); 1076 } 1077 1078 // Wake up 5 seconds later, the fatal handler may reset OnError or 1079 // ShowMessageBoxOnError when it is ready to abort. 1080 os::sleep(this, 5 * 1000, false); 1081 } 1082 } 1083 1084 PeriodicTask::real_time_tick(time_to_wait); 1085 1086 // If we have no more tasks left due to dynamic disenrollment, 1087 // shut down the thread since we don't currently support dynamic enrollment 1088 if (PeriodicTask::num_tasks() == 0) { 1089 _should_terminate = true; 1090 } 1091 } 1092 1093 // Signal that it is terminated 1094 { 1095 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag); 1096 _watcher_thread = NULL; 1097 Terminator_lock->notify(); 1098 } 1099 1100 // Thread destructor usually does this.. 1101 ThreadLocalStorage::set_thread(NULL); 1102 } 1103 1104 void WatcherThread::start() { 1105 if (watcher_thread() == NULL) { 1106 _should_terminate = false; 1107 // Create the single instance of WatcherThread 1108 new WatcherThread(); 1109 } 1110 } 1111 1112 void WatcherThread::stop() { 1113 // it is ok to take late safepoints here, if needed 1114 MutexLocker mu(Terminator_lock); 1115 _should_terminate = true; 1116 while(watcher_thread() != NULL) { 1117 // This wait should make safepoint checks, wait without a timeout, 1118 // and wait as a suspend-equivalent condition. 1119 // 1120 // Note: If the FlatProfiler is running, then this thread is waiting 1121 // for the WatcherThread to terminate and the WatcherThread, via the 1122 // FlatProfiler task, is waiting for the external suspend request on 1123 // this thread to complete. wait_for_ext_suspend_completion() will 1124 // eventually timeout, but that takes time. Making this wait a 1125 // suspend-equivalent condition solves that timeout problem. 1126 // 1127 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0, 1128 Mutex::_as_suspend_equivalent_flag); 1129 } 1130 } 1131 1132 void WatcherThread::print_on(outputStream* st) const { 1133 st->print("\"%s\" ", name()); 1134 Thread::print_on(st); 1135 st->cr(); 1136 } 1137 1138 // ======= JavaThread ======== 1139 1140 // A JavaThread is a normal Java thread 1141 1142 void JavaThread::initialize() { 1143 // Initialize fields 1144 1145 // Set the claimed par_id to -1 (ie not claiming any par_ids) 1146 set_claimed_par_id(-1); 1147 1148 set_saved_exception_pc(NULL); 1149 set_threadObj(NULL); 1150 _anchor.clear(); 1151 set_entry_point(NULL); 1152 set_jni_functions(jni_functions()); 1153 set_callee_target(NULL); 1154 set_vm_result(NULL); 1155 set_vm_result_2(NULL); 1156 set_vframe_array_head(NULL); 1157 set_vframe_array_last(NULL); 1158 set_deferred_locals(NULL); 1159 set_deopt_mark(NULL); 1160 clear_must_deopt_id(); 1161 set_monitor_chunks(NULL); 1162 set_next(NULL); 1163 set_thread_state(_thread_new); 1164 _terminated = _not_terminated; 1165 _privileged_stack_top = NULL; 1166 _array_for_gc = NULL; 1167 _suspend_equivalent = false; 1168 _in_deopt_handler = 0; 1169 _doing_unsafe_access = false; 1170 _stack_guard_state = stack_guard_unused; 1171 _exception_oop = NULL; 1172 _exception_pc = 0; 1173 _exception_handler_pc = 0; 1174 _exception_stack_size = 0; 1175 _jvmti_thread_state= NULL; 1176 _should_post_on_exceptions_flag = JNI_FALSE; 1177 _jvmti_get_loaded_classes_closure = NULL; 1178 _interp_only_mode = 0; 1179 _special_runtime_exit_condition = _no_async_condition; 1180 _pending_async_exception = NULL; 1181 _is_compiling = false; 1182 _thread_stat = NULL; 1183 _thread_stat = new ThreadStatistics(); 1184 _blocked_on_compilation = false; 1185 _jni_active_critical = 0; 1186 _do_not_unlock_if_synchronized = false; 1187 _cached_monitor_info = NULL; 1188 _parker = Parker::Allocate(this) ; 1189 1190 #ifndef PRODUCT 1191 _jmp_ring_index = 0; 1192 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) { 1193 record_jump(NULL, NULL, NULL, 0); 1194 } 1195 #endif /* PRODUCT */ 1196 1197 set_thread_profiler(NULL); 1198 if (FlatProfiler::is_active()) { 1199 // This is where we would decide to either give each thread it's own profiler 1200 // or use one global one from FlatProfiler, 1201 // or up to some count of the number of profiled threads, etc. 1202 ThreadProfiler* pp = new ThreadProfiler(); 1203 pp->engage(); 1204 set_thread_profiler(pp); 1205 } 1206 1207 // Setup safepoint state info for this thread 1208 ThreadSafepointState::create(this); 1209 1210 debug_only(_java_call_counter = 0); 1211 1212 // JVMTI PopFrame support 1213 _popframe_condition = popframe_inactive; 1214 _popframe_preserved_args = NULL; 1215 _popframe_preserved_args_size = 0; 1216 1217 pd_initialize(); 1218 } 1219 1220 #ifndef SERIALGC 1221 SATBMarkQueueSet JavaThread::_satb_mark_queue_set; 1222 DirtyCardQueueSet JavaThread::_dirty_card_queue_set; 1223 #endif // !SERIALGC 1224 1225 JavaThread::JavaThread(bool is_attaching) : 1226 Thread() 1227 #ifndef SERIALGC 1228 , _satb_mark_queue(&_satb_mark_queue_set), 1229 _dirty_card_queue(&_dirty_card_queue_set) 1230 #endif // !SERIALGC 1231 { 1232 initialize(); 1233 _is_attaching = is_attaching; 1234 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor"); 1235 } 1236 1237 bool JavaThread::reguard_stack(address cur_sp) { 1238 if (_stack_guard_state != stack_guard_yellow_disabled) { 1239 return true; // Stack already guarded or guard pages not needed. 1240 } 1241 1242 if (register_stack_overflow()) { 1243 // For those architectures which have separate register and 1244 // memory stacks, we must check the register stack to see if 1245 // it has overflowed. 1246 return false; 1247 } 1248 1249 // Java code never executes within the yellow zone: the latter is only 1250 // there to provoke an exception during stack banging. If java code 1251 // is executing there, either StackShadowPages should be larger, or 1252 // some exception code in c1, c2 or the interpreter isn't unwinding 1253 // when it should. 1254 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages"); 1255 1256 enable_stack_yellow_zone(); 1257 return true; 1258 } 1259 1260 bool JavaThread::reguard_stack(void) { 1261 return reguard_stack(os::current_stack_pointer()); 1262 } 1263 1264 1265 void JavaThread::block_if_vm_exited() { 1266 if (_terminated == _vm_exited) { 1267 // _vm_exited is set at safepoint, and Threads_lock is never released 1268 // we will block here forever 1269 Threads_lock->lock_without_safepoint_check(); 1270 ShouldNotReachHere(); 1271 } 1272 } 1273 1274 1275 // Remove this ifdef when C1 is ported to the compiler interface. 1276 static void compiler_thread_entry(JavaThread* thread, TRAPS); 1277 1278 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : 1279 Thread() 1280 #ifndef SERIALGC 1281 , _satb_mark_queue(&_satb_mark_queue_set), 1282 _dirty_card_queue(&_dirty_card_queue_set) 1283 #endif // !SERIALGC 1284 { 1285 if (TraceThreadEvents) { 1286 tty->print_cr("creating thread %p", this); 1287 } 1288 initialize(); 1289 _is_attaching = false; 1290 set_entry_point(entry_point); 1291 // Create the native thread itself. 1292 // %note runtime_23 1293 os::ThreadType thr_type = os::java_thread; 1294 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread : 1295 os::java_thread; 1296 os::create_thread(this, thr_type, stack_sz); 1297 1298 // The _osthread may be NULL here because we ran out of memory (too many threads active). 1299 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller 1300 // may hold a lock and all locks must be unlocked before throwing the exception (throwing 1301 // the exception consists of creating the exception object & initializing it, initialization 1302 // will leave the VM via a JavaCall and then all locks must be unlocked). 1303 // 1304 // The thread is still suspended when we reach here. Thread must be explicit started 1305 // by creator! Furthermore, the thread must also explicitly be added to the Threads list 1306 // by calling Threads:add. The reason why this is not done here, is because the thread 1307 // object must be fully initialized (take a look at JVM_Start) 1308 } 1309 1310 JavaThread::~JavaThread() { 1311 if (TraceThreadEvents) { 1312 tty->print_cr("terminate thread %p", this); 1313 } 1314 1315 // JSR166 -- return the parker to the free list 1316 Parker::Release(_parker); 1317 _parker = NULL ; 1318 1319 // Free any remaining previous UnrollBlock 1320 vframeArray* old_array = vframe_array_last(); 1321 1322 if (old_array != NULL) { 1323 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); 1324 old_array->set_unroll_block(NULL); 1325 delete old_info; 1326 delete old_array; 1327 } 1328 1329 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals(); 1330 if (deferred != NULL) { 1331 // This can only happen if thread is destroyed before deoptimization occurs. 1332 assert(deferred->length() != 0, "empty array!"); 1333 do { 1334 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0); 1335 deferred->remove_at(0); 1336 // individual jvmtiDeferredLocalVariableSet are CHeapObj's 1337 delete dlv; 1338 } while (deferred->length() != 0); 1339 delete deferred; 1340 } 1341 1342 // All Java related clean up happens in exit 1343 ThreadSafepointState::destroy(this); 1344 if (_thread_profiler != NULL) delete _thread_profiler; 1345 if (_thread_stat != NULL) delete _thread_stat; 1346 } 1347 1348 1349 // The first routine called by a new Java thread 1350 void JavaThread::run() { 1351 // initialize thread-local alloc buffer related fields 1352 this->initialize_tlab(); 1353 1354 // used to test validitity of stack trace backs 1355 this->record_base_of_stack_pointer(); 1356 1357 // Record real stack base and size. 1358 this->record_stack_base_and_size(); 1359 1360 // Initialize thread local storage; set before calling MutexLocker 1361 this->initialize_thread_local_storage(); 1362 1363 this->create_stack_guard_pages(); 1364 1365 // Thread is now sufficient initialized to be handled by the safepoint code as being 1366 // in the VM. Change thread state from _thread_new to _thread_in_vm 1367 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm); 1368 1369 assert(JavaThread::current() == this, "sanity check"); 1370 assert(!Thread::current()->owns_locks(), "sanity check"); 1371 1372 DTRACE_THREAD_PROBE(start, this); 1373 1374 // This operation might block. We call that after all safepoint checks for a new thread has 1375 // been completed. 1376 this->set_active_handles(JNIHandleBlock::allocate_block()); 1377 1378 if (JvmtiExport::should_post_thread_life()) { 1379 JvmtiExport::post_thread_start(this); 1380 } 1381 1382 // We call another function to do the rest so we are sure that the stack addresses used 1383 // from there will be lower than the stack base just computed 1384 thread_main_inner(); 1385 1386 // Note, thread is no longer valid at this point! 1387 } 1388 1389 1390 void JavaThread::thread_main_inner() { 1391 assert(JavaThread::current() == this, "sanity check"); 1392 assert(this->threadObj() != NULL, "just checking"); 1393 1394 // Execute thread entry point. If this thread is being asked to restart, 1395 // or has been stopped before starting, do not reexecute entry point. 1396 // Note: Due to JVM_StopThread we can have pending exceptions already! 1397 if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) { 1398 // enter the thread's entry point only if we have no pending exceptions 1399 HandleMark hm(this); 1400 this->entry_point()(this, this); 1401 } 1402 1403 DTRACE_THREAD_PROBE(stop, this); 1404 1405 this->exit(false); 1406 delete this; 1407 } 1408 1409 1410 static void ensure_join(JavaThread* thread) { 1411 // We do not need to grap the Threads_lock, since we are operating on ourself. 1412 Handle threadObj(thread, thread->threadObj()); 1413 assert(threadObj.not_null(), "java thread object must exist"); 1414 ObjectLocker lock(threadObj, thread); 1415 // Ignore pending exception (ThreadDeath), since we are exiting anyway 1416 thread->clear_pending_exception(); 1417 // It is of profound importance that we set the stillborn bit and reset the thread object, 1418 // before we do the notify. Since, changing these two variable will make JVM_IsAlive return 1419 // false. So in case another thread is doing a join on this thread , it will detect that the thread 1420 // is dead when it gets notified. 1421 java_lang_Thread::set_stillborn(threadObj()); 1422 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. 1423 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED); 1424 java_lang_Thread::set_thread(threadObj(), NULL); 1425 lock.notify_all(thread); 1426 // Ignore pending exception (ThreadDeath), since we are exiting anyway 1427 thread->clear_pending_exception(); 1428 } 1429 1430 1431 // For any new cleanup additions, please check to see if they need to be applied to 1432 // cleanup_failed_attach_current_thread as well. 1433 void JavaThread::exit(bool destroy_vm, ExitType exit_type) { 1434 assert(this == JavaThread::current(), "thread consistency check"); 1435 if (!InitializeJavaLangSystem) return; 1436 1437 HandleMark hm(this); 1438 Handle uncaught_exception(this, this->pending_exception()); 1439 this->clear_pending_exception(); 1440 Handle threadObj(this, this->threadObj()); 1441 assert(threadObj.not_null(), "Java thread object should be created"); 1442 1443 if (get_thread_profiler() != NULL) { 1444 get_thread_profiler()->disengage(); 1445 ResourceMark rm; 1446 get_thread_profiler()->print(get_thread_name()); 1447 } 1448 1449 1450 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place 1451 { 1452 EXCEPTION_MARK; 1453 1454 CLEAR_PENDING_EXCEPTION; 1455 } 1456 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This 1457 // has to be fixed by a runtime query method 1458 if (!destroy_vm || JDK_Version::is_jdk12x_version()) { 1459 // JSR-166: change call from from ThreadGroup.uncaughtException to 1460 // java.lang.Thread.dispatchUncaughtException 1461 if (uncaught_exception.not_null()) { 1462 Handle group(this, java_lang_Thread::threadGroup(threadObj())); 1463 Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT", 1464 (address)uncaught_exception(), (address)threadObj(), (address)group()); 1465 { 1466 EXCEPTION_MARK; 1467 // Check if the method Thread.dispatchUncaughtException() exists. If so 1468 // call it. Otherwise we have an older library without the JSR-166 changes, 1469 // so call ThreadGroup.uncaughtException() 1470 KlassHandle recvrKlass(THREAD, threadObj->klass()); 1471 CallInfo callinfo; 1472 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass()); 1473 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass, 1474 vmSymbolHandles::dispatchUncaughtException_name(), 1475 vmSymbolHandles::throwable_void_signature(), 1476 KlassHandle(), false, false, THREAD); 1477 CLEAR_PENDING_EXCEPTION; 1478 methodHandle method = callinfo.selected_method(); 1479 if (method.not_null()) { 1480 JavaValue result(T_VOID); 1481 JavaCalls::call_virtual(&result, 1482 threadObj, thread_klass, 1483 vmSymbolHandles::dispatchUncaughtException_name(), 1484 vmSymbolHandles::throwable_void_signature(), 1485 uncaught_exception, 1486 THREAD); 1487 } else { 1488 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass()); 1489 JavaValue result(T_VOID); 1490 JavaCalls::call_virtual(&result, 1491 group, thread_group, 1492 vmSymbolHandles::uncaughtException_name(), 1493 vmSymbolHandles::thread_throwable_void_signature(), 1494 threadObj, // Arg 1 1495 uncaught_exception, // Arg 2 1496 THREAD); 1497 } 1498 CLEAR_PENDING_EXCEPTION; 1499 } 1500 } 1501 1502 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during 1503 // the execution of the method. If that is not enough, then we don't really care. Thread.stop 1504 // is deprecated anyhow. 1505 { int count = 3; 1506 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) { 1507 EXCEPTION_MARK; 1508 JavaValue result(T_VOID); 1509 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass()); 1510 JavaCalls::call_virtual(&result, 1511 threadObj, thread_klass, 1512 vmSymbolHandles::exit_method_name(), 1513 vmSymbolHandles::void_method_signature(), 1514 THREAD); 1515 CLEAR_PENDING_EXCEPTION; 1516 } 1517 } 1518 1519 // notify JVMTI 1520 if (JvmtiExport::should_post_thread_life()) { 1521 JvmtiExport::post_thread_end(this); 1522 } 1523 1524 // We have notified the agents that we are exiting, before we go on, 1525 // we must check for a pending external suspend request and honor it 1526 // in order to not surprise the thread that made the suspend request. 1527 while (true) { 1528 { 1529 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1530 if (!is_external_suspend()) { 1531 set_terminated(_thread_exiting); 1532 ThreadService::current_thread_exiting(this); 1533 break; 1534 } 1535 // Implied else: 1536 // Things get a little tricky here. We have a pending external 1537 // suspend request, but we are holding the SR_lock so we 1538 // can't just self-suspend. So we temporarily drop the lock 1539 // and then self-suspend. 1540 } 1541 1542 ThreadBlockInVM tbivm(this); 1543 java_suspend_self(); 1544 1545 // We're done with this suspend request, but we have to loop around 1546 // and check again. Eventually we will get SR_lock without a pending 1547 // external suspend request and will be able to mark ourselves as 1548 // exiting. 1549 } 1550 // no more external suspends are allowed at this point 1551 } else { 1552 // before_exit() has already posted JVMTI THREAD_END events 1553 } 1554 1555 // Notify waiters on thread object. This has to be done after exit() is called 1556 // on the thread (if the thread is the last thread in a daemon ThreadGroup the 1557 // group should have the destroyed bit set before waiters are notified). 1558 ensure_join(this); 1559 assert(!this->has_pending_exception(), "ensure_join should have cleared"); 1560 1561 // 6282335 JNI DetachCurrentThread spec states that all Java monitors 1562 // held by this thread must be released. A detach operation must only 1563 // get here if there are no Java frames on the stack. Therefore, any 1564 // owned monitors at this point MUST be JNI-acquired monitors which are 1565 // pre-inflated and in the monitor cache. 1566 // 1567 // ensure_join() ignores IllegalThreadStateExceptions, and so does this. 1568 if (exit_type == jni_detach && JNIDetachReleasesMonitors) { 1569 assert(!this->has_last_Java_frame(), "detaching with Java frames?"); 1570 ObjectSynchronizer::release_monitors_owned_by_thread(this); 1571 assert(!this->has_pending_exception(), "release_monitors should have cleared"); 1572 } 1573 1574 // These things needs to be done while we are still a Java Thread. Make sure that thread 1575 // is in a consistent state, in case GC happens 1576 assert(_privileged_stack_top == NULL, "must be NULL when we get here"); 1577 1578 if (active_handles() != NULL) { 1579 JNIHandleBlock* block = active_handles(); 1580 set_active_handles(NULL); 1581 JNIHandleBlock::release_block(block); 1582 } 1583 1584 if (free_handle_block() != NULL) { 1585 JNIHandleBlock* block = free_handle_block(); 1586 set_free_handle_block(NULL); 1587 JNIHandleBlock::release_block(block); 1588 } 1589 1590 // These have to be removed while this is still a valid thread. 1591 remove_stack_guard_pages(); 1592 1593 if (UseTLAB) { 1594 tlab().make_parsable(true); // retire TLAB 1595 } 1596 1597 if (jvmti_thread_state() != NULL) { 1598 JvmtiExport::cleanup_thread(this); 1599 } 1600 1601 #ifndef SERIALGC 1602 // We must flush G1-related buffers before removing a thread from 1603 // the list of active threads. 1604 if (UseG1GC) { 1605 flush_barrier_queues(); 1606 } 1607 #endif 1608 1609 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread 1610 Threads::remove(this); 1611 } 1612 1613 #ifndef SERIALGC 1614 // Flush G1-related queues. 1615 void JavaThread::flush_barrier_queues() { 1616 satb_mark_queue().flush(); 1617 dirty_card_queue().flush(); 1618 } 1619 #endif 1620 1621 void JavaThread::cleanup_failed_attach_current_thread() { 1622 if (get_thread_profiler() != NULL) { 1623 get_thread_profiler()->disengage(); 1624 ResourceMark rm; 1625 get_thread_profiler()->print(get_thread_name()); 1626 } 1627 1628 if (active_handles() != NULL) { 1629 JNIHandleBlock* block = active_handles(); 1630 set_active_handles(NULL); 1631 JNIHandleBlock::release_block(block); 1632 } 1633 1634 if (free_handle_block() != NULL) { 1635 JNIHandleBlock* block = free_handle_block(); 1636 set_free_handle_block(NULL); 1637 JNIHandleBlock::release_block(block); 1638 } 1639 1640 // These have to be removed while this is still a valid thread. 1641 remove_stack_guard_pages(); 1642 1643 if (UseTLAB) { 1644 tlab().make_parsable(true); // retire TLAB, if any 1645 } 1646 1647 #ifndef SERIALGC 1648 if (UseG1GC) { 1649 flush_barrier_queues(); 1650 } 1651 #endif 1652 1653 Threads::remove(this); 1654 delete this; 1655 } 1656 1657 1658 1659 1660 JavaThread* JavaThread::active() { 1661 Thread* thread = ThreadLocalStorage::thread(); 1662 assert(thread != NULL, "just checking"); 1663 if (thread->is_Java_thread()) { 1664 return (JavaThread*) thread; 1665 } else { 1666 assert(thread->is_VM_thread(), "this must be a vm thread"); 1667 VM_Operation* op = ((VMThread*) thread)->vm_operation(); 1668 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread(); 1669 assert(ret->is_Java_thread(), "must be a Java thread"); 1670 return ret; 1671 } 1672 } 1673 1674 bool JavaThread::is_lock_owned(address adr) const { 1675 if (Thread::is_lock_owned(adr)) return true; 1676 1677 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { 1678 if (chunk->contains(adr)) return true; 1679 } 1680 1681 return false; 1682 } 1683 1684 1685 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) { 1686 chunk->set_next(monitor_chunks()); 1687 set_monitor_chunks(chunk); 1688 } 1689 1690 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) { 1691 guarantee(monitor_chunks() != NULL, "must be non empty"); 1692 if (monitor_chunks() == chunk) { 1693 set_monitor_chunks(chunk->next()); 1694 } else { 1695 MonitorChunk* prev = monitor_chunks(); 1696 while (prev->next() != chunk) prev = prev->next(); 1697 prev->set_next(chunk->next()); 1698 } 1699 } 1700 1701 // JVM support. 1702 1703 // Note: this function shouldn't block if it's called in 1704 // _thread_in_native_trans state (such as from 1705 // check_special_condition_for_native_trans()). 1706 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) { 1707 1708 if (has_last_Java_frame() && has_async_condition()) { 1709 // If we are at a polling page safepoint (not a poll return) 1710 // then we must defer async exception because live registers 1711 // will be clobbered by the exception path. Poll return is 1712 // ok because the call we a returning from already collides 1713 // with exception handling registers and so there is no issue. 1714 // (The exception handling path kills call result registers but 1715 // this is ok since the exception kills the result anyway). 1716 1717 if (is_at_poll_safepoint()) { 1718 // if the code we are returning to has deoptimized we must defer 1719 // the exception otherwise live registers get clobbered on the 1720 // exception path before deoptimization is able to retrieve them. 1721 // 1722 RegisterMap map(this, false); 1723 frame caller_fr = last_frame().sender(&map); 1724 assert(caller_fr.is_compiled_frame(), "what?"); 1725 if (caller_fr.is_deoptimized_frame()) { 1726 if (TraceExceptions) { 1727 ResourceMark rm; 1728 tty->print_cr("deferred async exception at compiled safepoint"); 1729 } 1730 return; 1731 } 1732 } 1733 } 1734 1735 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition(); 1736 if (condition == _no_async_condition) { 1737 // Conditions have changed since has_special_runtime_exit_condition() 1738 // was called: 1739 // - if we were here only because of an external suspend request, 1740 // then that was taken care of above (or cancelled) so we are done 1741 // - if we were here because of another async request, then it has 1742 // been cleared between the has_special_runtime_exit_condition() 1743 // and now so again we are done 1744 return; 1745 } 1746 1747 // Check for pending async. exception 1748 if (_pending_async_exception != NULL) { 1749 // Only overwrite an already pending exception, if it is not a threadDeath. 1750 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) { 1751 1752 // We cannot call Exceptions::_throw(...) here because we cannot block 1753 set_pending_exception(_pending_async_exception, __FILE__, __LINE__); 1754 1755 if (TraceExceptions) { 1756 ResourceMark rm; 1757 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this); 1758 if (has_last_Java_frame() ) { 1759 frame f = last_frame(); 1760 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp()); 1761 } 1762 tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name()); 1763 } 1764 _pending_async_exception = NULL; 1765 clear_has_async_exception(); 1766 } 1767 } 1768 1769 if (check_unsafe_error && 1770 condition == _async_unsafe_access_error && !has_pending_exception()) { 1771 condition = _no_async_condition; // done 1772 switch (thread_state()) { 1773 case _thread_in_vm: 1774 { 1775 JavaThread* THREAD = this; 1776 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); 1777 } 1778 case _thread_in_native: 1779 { 1780 ThreadInVMfromNative tiv(this); 1781 JavaThread* THREAD = this; 1782 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); 1783 } 1784 case _thread_in_Java: 1785 { 1786 ThreadInVMfromJava tiv(this); 1787 JavaThread* THREAD = this; 1788 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code"); 1789 } 1790 default: 1791 ShouldNotReachHere(); 1792 } 1793 } 1794 1795 assert(condition == _no_async_condition || has_pending_exception() || 1796 (!check_unsafe_error && condition == _async_unsafe_access_error), 1797 "must have handled the async condition, if no exception"); 1798 } 1799 1800 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) { 1801 // 1802 // Check for pending external suspend. Internal suspend requests do 1803 // not use handle_special_runtime_exit_condition(). 1804 // If JNIEnv proxies are allowed, don't self-suspend if the target 1805 // thread is not the current thread. In older versions of jdbx, jdbx 1806 // threads could call into the VM with another thread's JNIEnv so we 1807 // can be here operating on behalf of a suspended thread (4432884). 1808 bool do_self_suspend = is_external_suspend_with_lock(); 1809 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) { 1810 // 1811 // Because thread is external suspended the safepoint code will count 1812 // thread as at a safepoint. This can be odd because we can be here 1813 // as _thread_in_Java which would normally transition to _thread_blocked 1814 // at a safepoint. We would like to mark the thread as _thread_blocked 1815 // before calling java_suspend_self like all other callers of it but 1816 // we must then observe proper safepoint protocol. (We can't leave 1817 // _thread_blocked with a safepoint in progress). However we can be 1818 // here as _thread_in_native_trans so we can't use a normal transition 1819 // constructor/destructor pair because they assert on that type of 1820 // transition. We could do something like: 1821 // 1822 // JavaThreadState state = thread_state(); 1823 // set_thread_state(_thread_in_vm); 1824 // { 1825 // ThreadBlockInVM tbivm(this); 1826 // java_suspend_self() 1827 // } 1828 // set_thread_state(_thread_in_vm_trans); 1829 // if (safepoint) block; 1830 // set_thread_state(state); 1831 // 1832 // but that is pretty messy. Instead we just go with the way the 1833 // code has worked before and note that this is the only path to 1834 // java_suspend_self that doesn't put the thread in _thread_blocked 1835 // mode. 1836 1837 frame_anchor()->make_walkable(this); 1838 java_suspend_self(); 1839 1840 // We might be here for reasons in addition to the self-suspend request 1841 // so check for other async requests. 1842 } 1843 1844 if (check_asyncs) { 1845 check_and_handle_async_exceptions(); 1846 } 1847 } 1848 1849 void JavaThread::send_thread_stop(oop java_throwable) { 1850 assert(Thread::current()->is_VM_thread(), "should be in the vm thread"); 1851 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code"); 1852 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); 1853 1854 // Do not throw asynchronous exceptions against the compiler thread 1855 // (the compiler thread should not be a Java thread -- fix in 1.4.2) 1856 if (is_Compiler_thread()) return; 1857 1858 // This is a change from JDK 1.1, but JDK 1.2 will also do it: 1859 if (java_throwable->is_a(SystemDictionary::ThreadDeath_klass())) { 1860 java_lang_Thread::set_stillborn(threadObj()); 1861 } 1862 1863 { 1864 // Actually throw the Throwable against the target Thread - however 1865 // only if there is no thread death exception installed already. 1866 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) { 1867 // If the topmost frame is a runtime stub, then we are calling into 1868 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) 1869 // must deoptimize the caller before continuing, as the compiled exception handler table 1870 // may not be valid 1871 if (has_last_Java_frame()) { 1872 frame f = last_frame(); 1873 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) { 1874 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 1875 RegisterMap reg_map(this, UseBiasedLocking); 1876 frame compiled_frame = f.sender(®_map); 1877 if (compiled_frame.can_be_deoptimized()) { 1878 Deoptimization::deoptimize(this, compiled_frame, ®_map); 1879 } 1880 } 1881 } 1882 1883 // Set async. pending exception in thread. 1884 set_pending_async_exception(java_throwable); 1885 1886 if (TraceExceptions) { 1887 ResourceMark rm; 1888 tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name()); 1889 } 1890 // for AbortVMOnException flag 1891 NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name())); 1892 } 1893 } 1894 1895 1896 // Interrupt thread so it will wake up from a potential wait() 1897 Thread::interrupt(this); 1898 } 1899 1900 // External suspension mechanism. 1901 // 1902 // Tell the VM to suspend a thread when ever it knows that it does not hold on 1903 // to any VM_locks and it is at a transition 1904 // Self-suspension will happen on the transition out of the vm. 1905 // Catch "this" coming in from JNIEnv pointers when the thread has been freed 1906 // 1907 // Guarantees on return: 1908 // + Target thread will not execute any new bytecode (that's why we need to 1909 // force a safepoint) 1910 // + Target thread will not enter any new monitors 1911 // 1912 void JavaThread::java_suspend() { 1913 { MutexLocker mu(Threads_lock); 1914 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) { 1915 return; 1916 } 1917 } 1918 1919 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1920 if (!is_external_suspend()) { 1921 // a racing resume has cancelled us; bail out now 1922 return; 1923 } 1924 1925 // suspend is done 1926 uint32_t debug_bits = 0; 1927 // Warning: is_ext_suspend_completed() may temporarily drop the 1928 // SR_lock to allow the thread to reach a stable thread state if 1929 // it is currently in a transient thread state. 1930 if (is_ext_suspend_completed(false /* !called_by_wait */, 1931 SuspendRetryDelay, &debug_bits) ) { 1932 return; 1933 } 1934 } 1935 1936 VM_ForceSafepoint vm_suspend; 1937 VMThread::execute(&vm_suspend); 1938 } 1939 1940 // Part II of external suspension. 1941 // A JavaThread self suspends when it detects a pending external suspend 1942 // request. This is usually on transitions. It is also done in places 1943 // where continuing to the next transition would surprise the caller, 1944 // e.g., monitor entry. 1945 // 1946 // Returns the number of times that the thread self-suspended. 1947 // 1948 // Note: DO NOT call java_suspend_self() when you just want to block current 1949 // thread. java_suspend_self() is the second stage of cooperative 1950 // suspension for external suspend requests and should only be used 1951 // to complete an external suspend request. 1952 // 1953 int JavaThread::java_suspend_self() { 1954 int ret = 0; 1955 1956 // we are in the process of exiting so don't suspend 1957 if (is_exiting()) { 1958 clear_external_suspend(); 1959 return ret; 1960 } 1961 1962 assert(_anchor.walkable() || 1963 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()), 1964 "must have walkable stack"); 1965 1966 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1967 1968 assert(!this->is_ext_suspended(), 1969 "a thread trying to self-suspend should not already be suspended"); 1970 1971 if (this->is_suspend_equivalent()) { 1972 // If we are self-suspending as a result of the lifting of a 1973 // suspend equivalent condition, then the suspend_equivalent 1974 // flag is not cleared until we set the ext_suspended flag so 1975 // that wait_for_ext_suspend_completion() returns consistent 1976 // results. 1977 this->clear_suspend_equivalent(); 1978 } 1979 1980 // A racing resume may have cancelled us before we grabbed SR_lock 1981 // above. Or another external suspend request could be waiting for us 1982 // by the time we return from SR_lock()->wait(). The thread 1983 // that requested the suspension may already be trying to walk our 1984 // stack and if we return now, we can change the stack out from under 1985 // it. This would be a "bad thing (TM)" and cause the stack walker 1986 // to crash. We stay self-suspended until there are no more pending 1987 // external suspend requests. 1988 while (is_external_suspend()) { 1989 ret++; 1990 this->set_ext_suspended(); 1991 1992 // _ext_suspended flag is cleared by java_resume() 1993 while (is_ext_suspended()) { 1994 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag); 1995 } 1996 } 1997 1998 return ret; 1999 } 2000 2001 #ifdef ASSERT 2002 // verify the JavaThread has not yet been published in the Threads::list, and 2003 // hence doesn't need protection from concurrent access at this stage 2004 void JavaThread::verify_not_published() { 2005 if (!Threads_lock->owned_by_self()) { 2006 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag); 2007 assert( !Threads::includes(this), 2008 "java thread shouldn't have been published yet!"); 2009 } 2010 else { 2011 assert( !Threads::includes(this), 2012 "java thread shouldn't have been published yet!"); 2013 } 2014 } 2015 #endif 2016 2017 // Slow path when the native==>VM/Java barriers detect a safepoint is in 2018 // progress or when _suspend_flags is non-zero. 2019 // Current thread needs to self-suspend if there is a suspend request and/or 2020 // block if a safepoint is in progress. 2021 // Async exception ISN'T checked. 2022 // Note only the ThreadInVMfromNative transition can call this function 2023 // directly and when thread state is _thread_in_native_trans 2024 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) { 2025 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); 2026 2027 JavaThread *curJT = JavaThread::current(); 2028 bool do_self_suspend = thread->is_external_suspend(); 2029 2030 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition"); 2031 2032 // If JNIEnv proxies are allowed, don't self-suspend if the target 2033 // thread is not the current thread. In older versions of jdbx, jdbx 2034 // threads could call into the VM with another thread's JNIEnv so we 2035 // can be here operating on behalf of a suspended thread (4432884). 2036 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) { 2037 JavaThreadState state = thread->thread_state(); 2038 2039 // We mark this thread_blocked state as a suspend-equivalent so 2040 // that a caller to is_ext_suspend_completed() won't be confused. 2041 // The suspend-equivalent state is cleared by java_suspend_self(). 2042 thread->set_suspend_equivalent(); 2043 2044 // If the safepoint code sees the _thread_in_native_trans state, it will 2045 // wait until the thread changes to other thread state. There is no 2046 // guarantee on how soon we can obtain the SR_lock and complete the 2047 // self-suspend request. It would be a bad idea to let safepoint wait for 2048 // too long. Temporarily change the state to _thread_blocked to 2049 // let the VM thread know that this thread is ready for GC. The problem 2050 // of changing thread state is that safepoint could happen just after 2051 // java_suspend_self() returns after being resumed, and VM thread will 2052 // see the _thread_blocked state. We must check for safepoint 2053 // after restoring the state and make sure we won't leave while a safepoint 2054 // is in progress. 2055 thread->set_thread_state(_thread_blocked); 2056 thread->java_suspend_self(); 2057 thread->set_thread_state(state); 2058 // Make sure new state is seen by VM thread 2059 if (os::is_MP()) { 2060 if (UseMembar) { 2061 // Force a fence between the write above and read below 2062 OrderAccess::fence(); 2063 } else { 2064 // Must use this rather than serialization page in particular on Windows 2065 InterfaceSupport::serialize_memory(thread); 2066 } 2067 } 2068 } 2069 2070 if (SafepointSynchronize::do_call_back()) { 2071 // If we are safepointing, then block the caller which may not be 2072 // the same as the target thread (see above). 2073 SafepointSynchronize::block(curJT); 2074 } 2075 2076 if (thread->is_deopt_suspend()) { 2077 thread->clear_deopt_suspend(); 2078 RegisterMap map(thread, false); 2079 frame f = thread->last_frame(); 2080 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) { 2081 f = f.sender(&map); 2082 } 2083 if (f.id() == thread->must_deopt_id()) { 2084 thread->clear_must_deopt_id(); 2085 // Since we know we're safe to deopt the current state is a safe state 2086 f.deoptimize(thread, true); 2087 } else { 2088 fatal("missed deoptimization!"); 2089 } 2090 } 2091 } 2092 2093 // Slow path when the native==>VM/Java barriers detect a safepoint is in 2094 // progress or when _suspend_flags is non-zero. 2095 // Current thread needs to self-suspend if there is a suspend request and/or 2096 // block if a safepoint is in progress. 2097 // Also check for pending async exception (not including unsafe access error). 2098 // Note only the native==>VM/Java barriers can call this function and when 2099 // thread state is _thread_in_native_trans. 2100 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { 2101 check_safepoint_and_suspend_for_native_trans(thread); 2102 2103 if (thread->has_async_exception()) { 2104 // We are in _thread_in_native_trans state, don't handle unsafe 2105 // access error since that may block. 2106 thread->check_and_handle_async_exceptions(false); 2107 } 2108 } 2109 2110 // We need to guarantee the Threads_lock here, since resumes are not 2111 // allowed during safepoint synchronization 2112 // Can only resume from an external suspension 2113 void JavaThread::java_resume() { 2114 assert_locked_or_safepoint(Threads_lock); 2115 2116 // Sanity check: thread is gone, has started exiting or the thread 2117 // was not externally suspended. 2118 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) { 2119 return; 2120 } 2121 2122 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 2123 2124 clear_external_suspend(); 2125 2126 if (is_ext_suspended()) { 2127 clear_ext_suspended(); 2128 SR_lock()->notify_all(); 2129 } 2130 } 2131 2132 void JavaThread::create_stack_guard_pages() { 2133 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return; 2134 address low_addr = stack_base() - stack_size(); 2135 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); 2136 2137 int allocate = os::allocate_stack_guard_pages(); 2138 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len); 2139 2140 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) { 2141 warning("Attempt to allocate stack guard pages failed."); 2142 return; 2143 } 2144 2145 if (os::guard_memory((char *) low_addr, len)) { 2146 _stack_guard_state = stack_guard_enabled; 2147 } else { 2148 warning("Attempt to protect stack guard pages failed."); 2149 if (os::uncommit_memory((char *) low_addr, len)) { 2150 warning("Attempt to deallocate stack guard pages failed."); 2151 } 2152 } 2153 } 2154 2155 void JavaThread::remove_stack_guard_pages() { 2156 if (_stack_guard_state == stack_guard_unused) return; 2157 address low_addr = stack_base() - stack_size(); 2158 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); 2159 2160 if (os::allocate_stack_guard_pages()) { 2161 if (os::remove_stack_guard_pages((char *) low_addr, len)) { 2162 _stack_guard_state = stack_guard_unused; 2163 } else { 2164 warning("Attempt to deallocate stack guard pages failed."); 2165 } 2166 } else { 2167 if (_stack_guard_state == stack_guard_unused) return; 2168 if (os::unguard_memory((char *) low_addr, len)) { 2169 _stack_guard_state = stack_guard_unused; 2170 } else { 2171 warning("Attempt to unprotect stack guard pages failed."); 2172 } 2173 } 2174 } 2175 2176 void JavaThread::enable_stack_yellow_zone() { 2177 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2178 assert(_stack_guard_state != stack_guard_enabled, "already enabled"); 2179 2180 // The base notation is from the stacks point of view, growing downward. 2181 // We need to adjust it to work correctly with guard_memory() 2182 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); 2183 2184 guarantee(base < stack_base(),"Error calculating stack yellow zone"); 2185 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone"); 2186 2187 if (os::guard_memory((char *) base, stack_yellow_zone_size())) { 2188 _stack_guard_state = stack_guard_enabled; 2189 } else { 2190 warning("Attempt to guard stack yellow zone failed."); 2191 } 2192 enable_register_stack_guard(); 2193 } 2194 2195 void JavaThread::disable_stack_yellow_zone() { 2196 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2197 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled"); 2198 2199 // Simply return if called for a thread that does not use guard pages. 2200 if (_stack_guard_state == stack_guard_unused) return; 2201 2202 // The base notation is from the stacks point of view, growing downward. 2203 // We need to adjust it to work correctly with guard_memory() 2204 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); 2205 2206 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) { 2207 _stack_guard_state = stack_guard_yellow_disabled; 2208 } else { 2209 warning("Attempt to unguard stack yellow zone failed."); 2210 } 2211 disable_register_stack_guard(); 2212 } 2213 2214 void JavaThread::enable_stack_red_zone() { 2215 // The base notation is from the stacks point of view, growing downward. 2216 // We need to adjust it to work correctly with guard_memory() 2217 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2218 address base = stack_red_zone_base() - stack_red_zone_size(); 2219 2220 guarantee(base < stack_base(),"Error calculating stack red zone"); 2221 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone"); 2222 2223 if(!os::guard_memory((char *) base, stack_red_zone_size())) { 2224 warning("Attempt to guard stack red zone failed."); 2225 } 2226 } 2227 2228 void JavaThread::disable_stack_red_zone() { 2229 // The base notation is from the stacks point of view, growing downward. 2230 // We need to adjust it to work correctly with guard_memory() 2231 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2232 address base = stack_red_zone_base() - stack_red_zone_size(); 2233 if (!os::unguard_memory((char *)base, stack_red_zone_size())) { 2234 warning("Attempt to unguard stack red zone failed."); 2235 } 2236 } 2237 2238 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { 2239 // ignore is there is no stack 2240 if (!has_last_Java_frame()) return; 2241 // traverse the stack frames. Starts from top frame. 2242 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2243 frame* fr = fst.current(); 2244 f(fr, fst.register_map()); 2245 } 2246 } 2247 2248 2249 #ifndef PRODUCT 2250 // Deoptimization 2251 // Function for testing deoptimization 2252 void JavaThread::deoptimize() { 2253 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 2254 StackFrameStream fst(this, UseBiasedLocking); 2255 bool deopt = false; // Dump stack only if a deopt actually happens. 2256 bool only_at = strlen(DeoptimizeOnlyAt) > 0; 2257 // Iterate over all frames in the thread and deoptimize 2258 for(; !fst.is_done(); fst.next()) { 2259 if(fst.current()->can_be_deoptimized()) { 2260 2261 if (only_at) { 2262 // Deoptimize only at particular bcis. DeoptimizeOnlyAt 2263 // consists of comma or carriage return separated numbers so 2264 // search for the current bci in that string. 2265 address pc = fst.current()->pc(); 2266 nmethod* nm = (nmethod*) fst.current()->cb(); 2267 ScopeDesc* sd = nm->scope_desc_at( pc); 2268 char buffer[8]; 2269 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); 2270 size_t len = strlen(buffer); 2271 const char * found = strstr(DeoptimizeOnlyAt, buffer); 2272 while (found != NULL) { 2273 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && 2274 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { 2275 // Check that the bci found is bracketed by terminators. 2276 break; 2277 } 2278 found = strstr(found + 1, buffer); 2279 } 2280 if (!found) { 2281 continue; 2282 } 2283 } 2284 2285 if (DebugDeoptimization && !deopt) { 2286 deopt = true; // One-time only print before deopt 2287 tty->print_cr("[BEFORE Deoptimization]"); 2288 trace_frames(); 2289 trace_stack(); 2290 } 2291 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); 2292 } 2293 } 2294 2295 if (DebugDeoptimization && deopt) { 2296 tty->print_cr("[AFTER Deoptimization]"); 2297 trace_frames(); 2298 } 2299 } 2300 2301 2302 // Make zombies 2303 void JavaThread::make_zombies() { 2304 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2305 if (fst.current()->can_be_deoptimized()) { 2306 // it is a Java nmethod 2307 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); 2308 nm->make_not_entrant(); 2309 } 2310 } 2311 } 2312 #endif // PRODUCT 2313 2314 2315 void JavaThread::deoptimized_wrt_marked_nmethods() { 2316 if (!has_last_Java_frame()) return; 2317 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 2318 StackFrameStream fst(this, UseBiasedLocking); 2319 for(; !fst.is_done(); fst.next()) { 2320 if (fst.current()->should_be_deoptimized()) { 2321 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); 2322 } 2323 } 2324 } 2325 2326 2327 // GC support 2328 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); } 2329 2330 void JavaThread::gc_epilogue() { 2331 frames_do(frame_gc_epilogue); 2332 } 2333 2334 2335 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); } 2336 2337 void JavaThread::gc_prologue() { 2338 frames_do(frame_gc_prologue); 2339 } 2340 2341 // If the caller is a NamedThread, then remember, in the current scope, 2342 // the given JavaThread in its _processed_thread field. 2343 class RememberProcessedThread: public StackObj { 2344 NamedThread* _cur_thr; 2345 public: 2346 RememberProcessedThread(JavaThread* jthr) { 2347 Thread* thread = Thread::current(); 2348 if (thread->is_Named_thread()) { 2349 _cur_thr = (NamedThread *)thread; 2350 _cur_thr->set_processed_thread(jthr); 2351 } else { 2352 _cur_thr = NULL; 2353 } 2354 } 2355 2356 ~RememberProcessedThread() { 2357 if (_cur_thr) { 2358 _cur_thr->set_processed_thread(NULL); 2359 } 2360 } 2361 }; 2362 2363 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) { 2364 // Verify that the deferred card marks have been flushed. 2365 assert(deferred_card_mark().is_empty(), "Should be empty during GC"); 2366 2367 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do 2368 // since there may be more than one thread using each ThreadProfiler. 2369 2370 // Traverse the GCHandles 2371 Thread::oops_do(f, cf); 2372 2373 assert( (!has_last_Java_frame() && java_call_counter() == 0) || 2374 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); 2375 2376 if (has_last_Java_frame()) { 2377 // Record JavaThread to GC thread 2378 RememberProcessedThread rpt(this); 2379 2380 // Traverse the privileged stack 2381 if (_privileged_stack_top != NULL) { 2382 _privileged_stack_top->oops_do(f); 2383 } 2384 2385 // traverse the registered growable array 2386 if (_array_for_gc != NULL) { 2387 for (int index = 0; index < _array_for_gc->length(); index++) { 2388 f->do_oop(_array_for_gc->adr_at(index)); 2389 } 2390 } 2391 2392 // Traverse the monitor chunks 2393 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { 2394 chunk->oops_do(f); 2395 } 2396 2397 // Traverse the execution stack 2398 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2399 fst.current()->oops_do(f, cf, fst.register_map()); 2400 } 2401 } 2402 2403 // callee_target is never live across a gc point so NULL it here should 2404 // it still contain a methdOop. 2405 2406 set_callee_target(NULL); 2407 2408 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!"); 2409 // If we have deferred set_locals there might be oops waiting to be 2410 // written 2411 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals(); 2412 if (list != NULL) { 2413 for (int i = 0; i < list->length(); i++) { 2414 list->at(i)->oops_do(f); 2415 } 2416 } 2417 2418 // Traverse instance variables at the end since the GC may be moving things 2419 // around using this function 2420 f->do_oop((oop*) &_threadObj); 2421 f->do_oop((oop*) &_vm_result); 2422 f->do_oop((oop*) &_vm_result_2); 2423 f->do_oop((oop*) &_exception_oop); 2424 f->do_oop((oop*) &_pending_async_exception); 2425 2426 if (jvmti_thread_state() != NULL) { 2427 jvmti_thread_state()->oops_do(f); 2428 } 2429 } 2430 2431 void JavaThread::nmethods_do(CodeBlobClosure* cf) { 2432 Thread::nmethods_do(cf); // (super method is a no-op) 2433 2434 assert( (!has_last_Java_frame() && java_call_counter() == 0) || 2435 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); 2436 2437 if (has_last_Java_frame()) { 2438 // Traverse the execution stack 2439 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2440 fst.current()->nmethods_do(cf); 2441 } 2442 } 2443 } 2444 2445 // Printing 2446 const char* _get_thread_state_name(JavaThreadState _thread_state) { 2447 switch (_thread_state) { 2448 case _thread_uninitialized: return "_thread_uninitialized"; 2449 case _thread_new: return "_thread_new"; 2450 case _thread_new_trans: return "_thread_new_trans"; 2451 case _thread_in_native: return "_thread_in_native"; 2452 case _thread_in_native_trans: return "_thread_in_native_trans"; 2453 case _thread_in_vm: return "_thread_in_vm"; 2454 case _thread_in_vm_trans: return "_thread_in_vm_trans"; 2455 case _thread_in_Java: return "_thread_in_Java"; 2456 case _thread_in_Java_trans: return "_thread_in_Java_trans"; 2457 case _thread_blocked: return "_thread_blocked"; 2458 case _thread_blocked_trans: return "_thread_blocked_trans"; 2459 default: return "unknown thread state"; 2460 } 2461 } 2462 2463 #ifndef PRODUCT 2464 void JavaThread::print_thread_state_on(outputStream *st) const { 2465 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); 2466 }; 2467 void JavaThread::print_thread_state() const { 2468 print_thread_state_on(tty); 2469 }; 2470 #endif // PRODUCT 2471 2472 // Called by Threads::print() for VM_PrintThreads operation 2473 void JavaThread::print_on(outputStream *st) const { 2474 st->print("\"%s\" ", get_thread_name()); 2475 oop thread_oop = threadObj(); 2476 if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); 2477 Thread::print_on(st); 2478 // print guess for valid stack memory region (assume 4K pages); helps lock debugging 2479 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12)); 2480 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) { 2481 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); 2482 } 2483 #ifndef PRODUCT 2484 print_thread_state_on(st); 2485 _safepoint_state->print_on(st); 2486 #endif // PRODUCT 2487 } 2488 2489 // Called by fatal error handler. The difference between this and 2490 // JavaThread::print() is that we can't grab lock or allocate memory. 2491 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { 2492 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen)); 2493 oop thread_obj = threadObj(); 2494 if (thread_obj != NULL) { 2495 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon"); 2496 } 2497 st->print(" ["); 2498 st->print("%s", _get_thread_state_name(_thread_state)); 2499 if (osthread()) { 2500 st->print(", id=%d", osthread()->thread_id()); 2501 } 2502 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")", 2503 _stack_base - _stack_size, _stack_base); 2504 st->print("]"); 2505 return; 2506 } 2507 2508 // Verification 2509 2510 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } 2511 2512 void JavaThread::verify() { 2513 // Verify oops in the thread. 2514 oops_do(&VerifyOopClosure::verify_oop, NULL); 2515 2516 // Verify the stack frames. 2517 frames_do(frame_verify); 2518 } 2519 2520 // CR 6300358 (sub-CR 2137150) 2521 // Most callers of this method assume that it can't return NULL but a 2522 // thread may not have a name whilst it is in the process of attaching to 2523 // the VM - see CR 6412693, and there are places where a JavaThread can be 2524 // seen prior to having it's threadObj set (eg JNI attaching threads and 2525 // if vm exit occurs during initialization). These cases can all be accounted 2526 // for such that this method never returns NULL. 2527 const char* JavaThread::get_thread_name() const { 2528 #ifdef ASSERT 2529 // early safepoints can hit while current thread does not yet have TLS 2530 if (!SafepointSynchronize::is_at_safepoint()) { 2531 Thread *cur = Thread::current(); 2532 if (!(cur->is_Java_thread() && cur == this)) { 2533 // Current JavaThreads are allowed to get their own name without 2534 // the Threads_lock. 2535 assert_locked_or_safepoint(Threads_lock); 2536 } 2537 } 2538 #endif // ASSERT 2539 return get_thread_name_string(); 2540 } 2541 2542 // Returns a non-NULL representation of this thread's name, or a suitable 2543 // descriptive string if there is no set name 2544 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { 2545 const char* name_str; 2546 oop thread_obj = threadObj(); 2547 if (thread_obj != NULL) { 2548 typeArrayOop name = java_lang_Thread::name(thread_obj); 2549 if (name != NULL) { 2550 if (buf == NULL) { 2551 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2552 } 2553 else { 2554 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen); 2555 } 2556 } 2557 else if (is_attaching()) { // workaround for 6412693 - see 6404306 2558 name_str = "<no-name - thread is attaching>"; 2559 } 2560 else { 2561 name_str = Thread::name(); 2562 } 2563 } 2564 else { 2565 name_str = Thread::name(); 2566 } 2567 assert(name_str != NULL, "unexpected NULL thread name"); 2568 return name_str; 2569 } 2570 2571 2572 const char* JavaThread::get_threadgroup_name() const { 2573 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) 2574 oop thread_obj = threadObj(); 2575 if (thread_obj != NULL) { 2576 oop thread_group = java_lang_Thread::threadGroup(thread_obj); 2577 if (thread_group != NULL) { 2578 typeArrayOop name = java_lang_ThreadGroup::name(thread_group); 2579 // ThreadGroup.name can be null 2580 if (name != NULL) { 2581 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2582 return str; 2583 } 2584 } 2585 } 2586 return NULL; 2587 } 2588 2589 const char* JavaThread::get_parent_name() const { 2590 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) 2591 oop thread_obj = threadObj(); 2592 if (thread_obj != NULL) { 2593 oop thread_group = java_lang_Thread::threadGroup(thread_obj); 2594 if (thread_group != NULL) { 2595 oop parent = java_lang_ThreadGroup::parent(thread_group); 2596 if (parent != NULL) { 2597 typeArrayOop name = java_lang_ThreadGroup::name(parent); 2598 // ThreadGroup.name can be null 2599 if (name != NULL) { 2600 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2601 return str; 2602 } 2603 } 2604 } 2605 } 2606 return NULL; 2607 } 2608 2609 ThreadPriority JavaThread::java_priority() const { 2610 oop thr_oop = threadObj(); 2611 if (thr_oop == NULL) return NormPriority; // Bootstrapping 2612 ThreadPriority priority = java_lang_Thread::priority(thr_oop); 2613 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 2614 return priority; 2615 } 2616 2617 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { 2618 2619 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); 2620 // Link Java Thread object <-> C++ Thread 2621 2622 // Get the C++ thread object (an oop) from the JNI handle (a jthread) 2623 // and put it into a new Handle. The Handle "thread_oop" can then 2624 // be used to pass the C++ thread object to other methods. 2625 2626 // Set the Java level thread object (jthread) field of the 2627 // new thread (a JavaThread *) to C++ thread object using the 2628 // "thread_oop" handle. 2629 2630 // Set the thread field (a JavaThread *) of the 2631 // oop representing the java_lang_Thread to the new thread (a JavaThread *). 2632 2633 Handle thread_oop(Thread::current(), 2634 JNIHandles::resolve_non_null(jni_thread)); 2635 assert(instanceKlass::cast(thread_oop->klass())->is_linked(), 2636 "must be initialized"); 2637 set_threadObj(thread_oop()); 2638 java_lang_Thread::set_thread(thread_oop(), this); 2639 2640 if (prio == NoPriority) { 2641 prio = java_lang_Thread::priority(thread_oop()); 2642 assert(prio != NoPriority, "A valid priority should be present"); 2643 } 2644 2645 // Push the Java priority down to the native thread; needs Threads_lock 2646 Thread::set_priority(this, prio); 2647 2648 // Add the new thread to the Threads list and set it in motion. 2649 // We must have threads lock in order to call Threads::add. 2650 // It is crucial that we do not block before the thread is 2651 // added to the Threads list for if a GC happens, then the java_thread oop 2652 // will not be visited by GC. 2653 Threads::add(this); 2654 } 2655 2656 oop JavaThread::current_park_blocker() { 2657 // Support for JSR-166 locks 2658 oop thread_oop = threadObj(); 2659 if (thread_oop != NULL && 2660 JDK_Version::current().supports_thread_park_blocker()) { 2661 return java_lang_Thread::park_blocker(thread_oop); 2662 } 2663 return NULL; 2664 } 2665 2666 2667 void JavaThread::print_stack_on(outputStream* st) { 2668 if (!has_last_Java_frame()) return; 2669 ResourceMark rm; 2670 HandleMark hm; 2671 2672 RegisterMap reg_map(this); 2673 vframe* start_vf = last_java_vframe(®_map); 2674 int count = 0; 2675 for (vframe* f = start_vf; f; f = f->sender() ) { 2676 if (f->is_java_frame()) { 2677 javaVFrame* jvf = javaVFrame::cast(f); 2678 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 2679 2680 // Print out lock information 2681 if (JavaMonitorsInStackTrace) { 2682 jvf->print_lock_info_on(st, count); 2683 } 2684 } else { 2685 // Ignore non-Java frames 2686 } 2687 2688 // Bail-out case for too deep stacks 2689 count++; 2690 if (MaxJavaStackTraceDepth == count) return; 2691 } 2692 } 2693 2694 2695 // JVMTI PopFrame support 2696 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { 2697 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments"); 2698 if (in_bytes(size_in_bytes) != 0) { 2699 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes)); 2700 _popframe_preserved_args_size = in_bytes(size_in_bytes); 2701 Copy::conjoint_bytes(start, _popframe_preserved_args, _popframe_preserved_args_size); 2702 } 2703 } 2704 2705 void* JavaThread::popframe_preserved_args() { 2706 return _popframe_preserved_args; 2707 } 2708 2709 ByteSize JavaThread::popframe_preserved_args_size() { 2710 return in_ByteSize(_popframe_preserved_args_size); 2711 } 2712 2713 WordSize JavaThread::popframe_preserved_args_size_in_words() { 2714 int sz = in_bytes(popframe_preserved_args_size()); 2715 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); 2716 return in_WordSize(sz / wordSize); 2717 } 2718 2719 void JavaThread::popframe_free_preserved_args() { 2720 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice"); 2721 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args); 2722 _popframe_preserved_args = NULL; 2723 _popframe_preserved_args_size = 0; 2724 } 2725 2726 #ifndef PRODUCT 2727 2728 void JavaThread::trace_frames() { 2729 tty->print_cr("[Describe stack]"); 2730 int frame_no = 1; 2731 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2732 tty->print(" %d. ", frame_no++); 2733 fst.current()->print_value_on(tty,this); 2734 tty->cr(); 2735 } 2736 } 2737 2738 2739 void JavaThread::trace_stack_from(vframe* start_vf) { 2740 ResourceMark rm; 2741 int vframe_no = 1; 2742 for (vframe* f = start_vf; f; f = f->sender() ) { 2743 if (f->is_java_frame()) { 2744 javaVFrame::cast(f)->print_activation(vframe_no++); 2745 } else { 2746 f->print(); 2747 } 2748 if (vframe_no > StackPrintLimit) { 2749 tty->print_cr("...<more frames>..."); 2750 return; 2751 } 2752 } 2753 } 2754 2755 2756 void JavaThread::trace_stack() { 2757 if (!has_last_Java_frame()) return; 2758 ResourceMark rm; 2759 HandleMark hm; 2760 RegisterMap reg_map(this); 2761 trace_stack_from(last_java_vframe(®_map)); 2762 } 2763 2764 2765 #endif // PRODUCT 2766 2767 2768 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) { 2769 assert(reg_map != NULL, "a map must be given"); 2770 frame f = last_frame(); 2771 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) { 2772 if (vf->is_java_frame()) return javaVFrame::cast(vf); 2773 } 2774 return NULL; 2775 } 2776 2777 2778 klassOop JavaThread::security_get_caller_class(int depth) { 2779 vframeStream vfst(this); 2780 vfst.security_get_caller_frame(depth); 2781 if (!vfst.at_end()) { 2782 return vfst.method()->method_holder(); 2783 } 2784 return NULL; 2785 } 2786 2787 static void compiler_thread_entry(JavaThread* thread, TRAPS) { 2788 assert(thread->is_Compiler_thread(), "must be compiler thread"); 2789 CompileBroker::compiler_thread_loop(); 2790 } 2791 2792 // Create a CompilerThread 2793 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters) 2794 : JavaThread(&compiler_thread_entry) { 2795 _env = NULL; 2796 _log = NULL; 2797 _task = NULL; 2798 _queue = queue; 2799 _counters = counters; 2800 _buffer_blob = NULL; 2801 2802 #ifndef PRODUCT 2803 _ideal_graph_printer = NULL; 2804 #endif 2805 } 2806 2807 2808 // ======= Threads ======== 2809 2810 // The Threads class links together all active threads, and provides 2811 // operations over all threads. It is protected by its own Mutex 2812 // lock, which is also used in other contexts to protect thread 2813 // operations from having the thread being operated on from exiting 2814 // and going away unexpectedly (e.g., safepoint synchronization) 2815 2816 JavaThread* Threads::_thread_list = NULL; 2817 int Threads::_number_of_threads = 0; 2818 int Threads::_number_of_non_daemon_threads = 0; 2819 int Threads::_return_code = 0; 2820 size_t JavaThread::_stack_size_at_create = 0; 2821 2822 // All JavaThreads 2823 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next()) 2824 2825 void os_stream(); 2826 2827 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system) 2828 void Threads::threads_do(ThreadClosure* tc) { 2829 assert_locked_or_safepoint(Threads_lock); 2830 // ALL_JAVA_THREADS iterates through all JavaThreads 2831 ALL_JAVA_THREADS(p) { 2832 tc->do_thread(p); 2833 } 2834 // Someday we could have a table or list of all non-JavaThreads. 2835 // For now, just manually iterate through them. 2836 tc->do_thread(VMThread::vm_thread()); 2837 Universe::heap()->gc_threads_do(tc); 2838 WatcherThread *wt = WatcherThread::watcher_thread(); 2839 // Strictly speaking, the following NULL check isn't sufficient to make sure 2840 // the data for WatcherThread is still valid upon being examined. However, 2841 // considering that WatchThread terminates when the VM is on the way to 2842 // exit at safepoint, the chance of the above is extremely small. The right 2843 // way to prevent termination of WatcherThread would be to acquire 2844 // Terminator_lock, but we can't do that without violating the lock rank 2845 // checking in some cases. 2846 if (wt != NULL) 2847 tc->do_thread(wt); 2848 2849 // If CompilerThreads ever become non-JavaThreads, add them here 2850 } 2851 2852 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) { 2853 2854 extern void JDK_Version_init(); 2855 2856 // Check version 2857 if (!is_supported_jni_version(args->version)) return JNI_EVERSION; 2858 2859 // Initialize the output stream module 2860 ostream_init(); 2861 2862 // Process java launcher properties. 2863 Arguments::process_sun_java_launcher_properties(args); 2864 2865 // Initialize the os module before using TLS 2866 os::init(); 2867 2868 // Initialize system properties. 2869 Arguments::init_system_properties(); 2870 2871 // So that JDK version can be used as a discrimintor when parsing arguments 2872 JDK_Version_init(); 2873 2874 // Parse arguments 2875 jint parse_result = Arguments::parse(args); 2876 if (parse_result != JNI_OK) return parse_result; 2877 2878 if (PauseAtStartup) { 2879 os::pause(); 2880 } 2881 2882 HS_DTRACE_PROBE(hotspot, vm__init__begin); 2883 2884 // Record VM creation timing statistics 2885 TraceVmCreationTime create_vm_timer; 2886 create_vm_timer.start(); 2887 2888 // Timing (must come after argument parsing) 2889 TraceTime timer("Create VM", TraceStartupTime); 2890 2891 // Initialize the os module after parsing the args 2892 jint os_init_2_result = os::init_2(); 2893 if (os_init_2_result != JNI_OK) return os_init_2_result; 2894 2895 // Initialize output stream logging 2896 ostream_init_log(); 2897 2898 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad 2899 // Must be before create_vm_init_agents() 2900 if (Arguments::init_libraries_at_startup()) { 2901 convert_vm_init_libraries_to_agents(); 2902 } 2903 2904 // Launch -agentlib/-agentpath and converted -Xrun agents 2905 if (Arguments::init_agents_at_startup()) { 2906 create_vm_init_agents(); 2907 } 2908 2909 // Initialize Threads state 2910 _thread_list = NULL; 2911 _number_of_threads = 0; 2912 _number_of_non_daemon_threads = 0; 2913 2914 // Initialize TLS 2915 ThreadLocalStorage::init(); 2916 2917 // Initialize global data structures and create system classes in heap 2918 vm_init_globals(); 2919 2920 // Attach the main thread to this os thread 2921 JavaThread* main_thread = new JavaThread(); 2922 main_thread->set_thread_state(_thread_in_vm); 2923 // must do this before set_active_handles and initialize_thread_local_storage 2924 // Note: on solaris initialize_thread_local_storage() will (indirectly) 2925 // change the stack size recorded here to one based on the java thread 2926 // stacksize. This adjusted size is what is used to figure the placement 2927 // of the guard pages. 2928 main_thread->record_stack_base_and_size(); 2929 main_thread->initialize_thread_local_storage(); 2930 2931 main_thread->set_active_handles(JNIHandleBlock::allocate_block()); 2932 2933 if (!main_thread->set_as_starting_thread()) { 2934 vm_shutdown_during_initialization( 2935 "Failed necessary internal allocation. Out of swap space"); 2936 delete main_thread; 2937 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 2938 return JNI_ENOMEM; 2939 } 2940 2941 // Enable guard page *after* os::create_main_thread(), otherwise it would 2942 // crash Linux VM, see notes in os_linux.cpp. 2943 main_thread->create_stack_guard_pages(); 2944 2945 // Initialize Java-Leve synchronization subsystem 2946 ObjectSynchronizer::Initialize() ; 2947 2948 // Initialize global modules 2949 jint status = init_globals(); 2950 if (status != JNI_OK) { 2951 delete main_thread; 2952 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 2953 return status; 2954 } 2955 2956 HandleMark hm; 2957 2958 { MutexLocker mu(Threads_lock); 2959 Threads::add(main_thread); 2960 } 2961 2962 // Any JVMTI raw monitors entered in onload will transition into 2963 // real raw monitor. VM is setup enough here for raw monitor enter. 2964 JvmtiExport::transition_pending_onload_raw_monitors(); 2965 2966 if (VerifyBeforeGC && 2967 Universe::heap()->total_collections() >= VerifyGCStartAt) { 2968 Universe::heap()->prepare_for_verify(); 2969 Universe::verify(); // make sure we're starting with a clean slate 2970 } 2971 2972 // Create the VMThread 2973 { TraceTime timer("Start VMThread", TraceStartupTime); 2974 VMThread::create(); 2975 Thread* vmthread = VMThread::vm_thread(); 2976 2977 if (!os::create_thread(vmthread, os::vm_thread)) 2978 vm_exit_during_initialization("Cannot create VM thread. Out of system resources."); 2979 2980 // Wait for the VM thread to become ready, and VMThread::run to initialize 2981 // Monitors can have spurious returns, must always check another state flag 2982 { 2983 MutexLocker ml(Notify_lock); 2984 os::start_thread(vmthread); 2985 while (vmthread->active_handles() == NULL) { 2986 Notify_lock->wait(); 2987 } 2988 } 2989 } 2990 2991 assert (Universe::is_fully_initialized(), "not initialized"); 2992 EXCEPTION_MARK; 2993 2994 // At this point, the Universe is initialized, but we have not executed 2995 // any byte code. Now is a good time (the only time) to dump out the 2996 // internal state of the JVM for sharing. 2997 2998 if (DumpSharedSpaces) { 2999 Universe::heap()->preload_and_dump(CHECK_0); 3000 ShouldNotReachHere(); 3001 } 3002 3003 // Always call even when there are not JVMTI environments yet, since environments 3004 // may be attached late and JVMTI must track phases of VM execution 3005 JvmtiExport::enter_start_phase(); 3006 3007 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. 3008 JvmtiExport::post_vm_start(); 3009 3010 { 3011 TraceTime timer("Initialize java.lang classes", TraceStartupTime); 3012 3013 if (EagerXrunInit && Arguments::init_libraries_at_startup()) { 3014 create_vm_init_libraries(); 3015 } 3016 3017 if (InitializeJavaLangString) { 3018 initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0); 3019 } else { 3020 warning("java.lang.String not initialized"); 3021 } 3022 3023 if (AggressiveOpts) { 3024 { 3025 // Forcibly initialize java/util/HashMap and mutate the private 3026 // static final "frontCacheEnabled" field before we start creating instances 3027 #ifdef ASSERT 3028 klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); 3029 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet"); 3030 #endif 3031 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); 3032 KlassHandle k = KlassHandle(THREAD, k_o); 3033 guarantee(k.not_null(), "Must find java/util/HashMap"); 3034 instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); 3035 ik->initialize(CHECK_0); 3036 fieldDescriptor fd; 3037 // Possible we might not find this field; if so, don't break 3038 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { 3039 k()->bool_field_put(fd.offset(), true); 3040 } 3041 } 3042 3043 if (UseStringCache) { 3044 // Forcibly initialize java/lang/StringValue and mutate the private 3045 // static final "stringCacheEnabled" field before we start creating instances 3046 klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_StringValue(), Handle(), Handle(), CHECK_0); 3047 // Possible that StringValue isn't present: if so, silently don't break 3048 if (k_o != NULL) { 3049 KlassHandle k = KlassHandle(THREAD, k_o); 3050 instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); 3051 ik->initialize(CHECK_0); 3052 fieldDescriptor fd; 3053 // Possible we might not find this field: if so, silently don't break 3054 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { 3055 k()->bool_field_put(fd.offset(), true); 3056 } 3057 } 3058 } 3059 } 3060 3061 // Initialize java_lang.System (needed before creating the thread) 3062 if (InitializeJavaLangSystem) { 3063 initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0); 3064 initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0); 3065 Handle thread_group = create_initial_thread_group(CHECK_0); 3066 Universe::set_main_thread_group(thread_group()); 3067 initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0); 3068 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0); 3069 main_thread->set_threadObj(thread_object); 3070 // Set thread status to running since main thread has 3071 // been started and running. 3072 java_lang_Thread::set_thread_status(thread_object, 3073 java_lang_Thread::RUNNABLE); 3074 3075 // The VM preresolve methods to these classes. Make sure that get initialized 3076 initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0); 3077 initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0); 3078 // The VM creates & returns objects of this class. Make sure it's initialized. 3079 initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0); 3080 call_initializeSystemClass(CHECK_0); 3081 } else { 3082 warning("java.lang.System not initialized"); 3083 } 3084 3085 // an instance of OutOfMemory exception has been allocated earlier 3086 if (InitializeJavaLangExceptionsErrors) { 3087 initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0); 3088 initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0); 3089 initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0); 3090 initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0); 3091 initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0); 3092 initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0); 3093 initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0); 3094 } else { 3095 warning("java.lang.OutOfMemoryError has not been initialized"); 3096 warning("java.lang.NullPointerException has not been initialized"); 3097 warning("java.lang.ClassCastException has not been initialized"); 3098 warning("java.lang.ArrayStoreException has not been initialized"); 3099 warning("java.lang.ArithmeticException has not been initialized"); 3100 warning("java.lang.StackOverflowError has not been initialized"); 3101 } 3102 3103 if (EnableInvokeDynamic) { 3104 // JSR 292: An intialized java.dyn.InvokeDynamic is required in 3105 // the compiler. 3106 initialize_class(vmSymbolHandles::java_dyn_InvokeDynamic(), CHECK_0); 3107 } 3108 } 3109 3110 // See : bugid 4211085. 3111 // Background : the static initializer of java.lang.Compiler tries to read 3112 // property"java.compiler" and read & write property "java.vm.info". 3113 // When a security manager is installed through the command line 3114 // option "-Djava.security.manager", the above properties are not 3115 // readable and the static initializer for java.lang.Compiler fails 3116 // resulting in a NoClassDefFoundError. This can happen in any 3117 // user code which calls methods in java.lang.Compiler. 3118 // Hack : the hack is to pre-load and initialize this class, so that only 3119 // system domains are on the stack when the properties are read. 3120 // Currently even the AWT code has calls to methods in java.lang.Compiler. 3121 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT. 3122 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and 3123 // read and write"java.vm.info" in the default policy file. See bugid 4211383 3124 // Once that is done, we should remove this hack. 3125 initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0); 3126 3127 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to 3128 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot 3129 // compiler does not get loaded through java.lang.Compiler). "java -version" with the 3130 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here. 3131 // This should also be taken out as soon as 4211383 gets fixed. 3132 reset_vm_info_property(CHECK_0); 3133 3134 quicken_jni_functions(); 3135 3136 // Set flag that basic initialization has completed. Used by exceptions and various 3137 // debug stuff, that does not work until all basic classes have been initialized. 3138 set_init_completed(); 3139 3140 HS_DTRACE_PROBE(hotspot, vm__init__end); 3141 3142 // record VM initialization completion time 3143 Management::record_vm_init_completed(); 3144 3145 // Compute system loader. Note that this has to occur after set_init_completed, since 3146 // valid exceptions may be thrown in the process. 3147 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and 3148 // set_init_completed has just been called, causing exceptions not to be shortcut 3149 // anymore. We call vm_exit_during_initialization directly instead. 3150 SystemDictionary::compute_java_system_loader(THREAD); 3151 if (HAS_PENDING_EXCEPTION) { 3152 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); 3153 } 3154 3155 #ifdef KERNEL 3156 if (JDK_Version::is_gte_jdk17x_version()) { 3157 set_jkernel_boot_classloader_hook(THREAD); 3158 } 3159 #endif // KERNEL 3160 3161 #ifndef SERIALGC 3162 // Support for ConcurrentMarkSweep. This should be cleaned up 3163 // and better encapsulated. The ugly nested if test would go away 3164 // once things are properly refactored. XXX YSR 3165 if (UseConcMarkSweepGC || UseG1GC) { 3166 if (UseConcMarkSweepGC) { 3167 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD); 3168 } else { 3169 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD); 3170 } 3171 if (HAS_PENDING_EXCEPTION) { 3172 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); 3173 } 3174 } 3175 #endif // SERIALGC 3176 3177 // Always call even when there are not JVMTI environments yet, since environments 3178 // may be attached late and JVMTI must track phases of VM execution 3179 JvmtiExport::enter_live_phase(); 3180 3181 // Signal Dispatcher needs to be started before VMInit event is posted 3182 os::signal_init(); 3183 3184 // Start Attach Listener if +StartAttachListener or it can't be started lazily 3185 if (!DisableAttachMechanism) { 3186 if (StartAttachListener || AttachListener::init_at_startup()) { 3187 AttachListener::init(); 3188 } 3189 } 3190 3191 // Launch -Xrun agents 3192 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP 3193 // back-end can launch with -Xdebug -Xrunjdwp. 3194 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) { 3195 create_vm_init_libraries(); 3196 } 3197 3198 // Notify JVMTI agents that VM initialization is complete - nop if no agents. 3199 JvmtiExport::post_vm_initialized(); 3200 3201 Chunk::start_chunk_pool_cleaner_task(); 3202 3203 // initialize compiler(s) 3204 CompileBroker::compilation_init(); 3205 3206 Management::initialize(THREAD); 3207 if (HAS_PENDING_EXCEPTION) { 3208 // management agent fails to start possibly due to 3209 // configuration problem and is responsible for printing 3210 // stack trace if appropriate. Simply exit VM. 3211 vm_exit(1); 3212 } 3213 3214 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true); 3215 if (Arguments::has_alloc_profile()) AllocationProfiler::engage(); 3216 if (MemProfiling) MemProfiler::engage(); 3217 StatSampler::engage(); 3218 if (CheckJNICalls) JniPeriodicChecker::engage(); 3219 3220 BiasedLocking::init(); 3221 3222 3223 // Start up the WatcherThread if there are any periodic tasks 3224 // NOTE: All PeriodicTasks should be registered by now. If they 3225 // aren't, late joiners might appear to start slowly (we might 3226 // take a while to process their first tick). 3227 if (PeriodicTask::num_tasks() > 0) { 3228 WatcherThread::start(); 3229 } 3230 3231 create_vm_timer.end(); 3232 return JNI_OK; 3233 } 3234 3235 // type for the Agent_OnLoad and JVM_OnLoad entry points 3236 extern "C" { 3237 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *); 3238 } 3239 // Find a command line agent library and return its entry point for 3240 // -agentlib: -agentpath: -Xrun 3241 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array. 3242 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) { 3243 OnLoadEntry_t on_load_entry = NULL; 3244 void *library = agent->os_lib(); // check if we have looked it up before 3245 3246 if (library == NULL) { 3247 char buffer[JVM_MAXPATHLEN]; 3248 char ebuf[1024]; 3249 const char *name = agent->name(); 3250 3251 if (agent->is_absolute_path()) { 3252 library = hpi::dll_load(name, ebuf, sizeof ebuf); 3253 if (library == NULL) { 3254 // If we can't find the agent, exit. 3255 vm_exit_during_initialization("Could not find agent library in absolute path", name); 3256 } 3257 } else { 3258 // Try to load the agent from the standard dll directory 3259 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name); 3260 library = hpi::dll_load(buffer, ebuf, sizeof ebuf); 3261 #ifdef KERNEL 3262 // Download instrument dll 3263 if (library == NULL && strcmp(name, "instrument") == 0) { 3264 char *props = Arguments::get_kernel_properties(); 3265 char *home = Arguments::get_java_home(); 3266 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false" 3267 " sun.jkernel.DownloadManager -download client_jvm"; 3268 int length = strlen(props) + strlen(home) + strlen(fmt) + 1; 3269 char *cmd = AllocateHeap(length); 3270 jio_snprintf(cmd, length, fmt, home, props); 3271 int status = os::fork_and_exec(cmd); 3272 FreeHeap(props); 3273 FreeHeap(cmd); 3274 if (status == -1) { 3275 warning(cmd); 3276 vm_exit_during_initialization("fork_and_exec failed: %s", 3277 strerror(errno)); 3278 } 3279 // when this comes back the instrument.dll should be where it belongs. 3280 library = hpi::dll_load(buffer, ebuf, sizeof ebuf); 3281 } 3282 #endif // KERNEL 3283 if (library == NULL) { // Try the local directory 3284 char ns[1] = {0}; 3285 hpi::dll_build_name(buffer, sizeof(buffer), ns, name); 3286 library = hpi::dll_load(buffer, 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 on the library path or in the local directory", name); 3290 } 3291 } 3292 } 3293 agent->set_os_lib(library); 3294 } 3295 3296 // Find the OnLoad function. 3297 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) { 3298 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index])); 3299 if (on_load_entry != NULL) break; 3300 } 3301 return on_load_entry; 3302 } 3303 3304 // Find the JVM_OnLoad entry point 3305 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) { 3306 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS; 3307 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); 3308 } 3309 3310 // Find the Agent_OnLoad entry point 3311 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) { 3312 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS; 3313 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); 3314 } 3315 3316 // For backwards compatibility with -Xrun 3317 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be 3318 // treated like -agentpath: 3319 // Must be called before agent libraries are created 3320 void Threads::convert_vm_init_libraries_to_agents() { 3321 AgentLibrary* agent; 3322 AgentLibrary* next; 3323 3324 for (agent = Arguments::libraries(); agent != NULL; agent = next) { 3325 next = agent->next(); // cache the next agent now as this agent may get moved off this list 3326 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); 3327 3328 // If there is an JVM_OnLoad function it will get called later, 3329 // otherwise see if there is an Agent_OnLoad 3330 if (on_load_entry == NULL) { 3331 on_load_entry = lookup_agent_on_load(agent); 3332 if (on_load_entry != NULL) { 3333 // switch it to the agent list -- so that Agent_OnLoad will be called, 3334 // JVM_OnLoad won't be attempted and Agent_OnUnload will 3335 Arguments::convert_library_to_agent(agent); 3336 } else { 3337 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name()); 3338 } 3339 } 3340 } 3341 } 3342 3343 // Create agents for -agentlib: -agentpath: and converted -Xrun 3344 // Invokes Agent_OnLoad 3345 // Called very early -- before JavaThreads exist 3346 void Threads::create_vm_init_agents() { 3347 extern struct JavaVM_ main_vm; 3348 AgentLibrary* agent; 3349 3350 JvmtiExport::enter_onload_phase(); 3351 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 3352 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent); 3353 3354 if (on_load_entry != NULL) { 3355 // Invoke the Agent_OnLoad function 3356 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); 3357 if (err != JNI_OK) { 3358 vm_exit_during_initialization("agent library failed to init", agent->name()); 3359 } 3360 } else { 3361 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name()); 3362 } 3363 } 3364 JvmtiExport::enter_primordial_phase(); 3365 } 3366 3367 extern "C" { 3368 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *); 3369 } 3370 3371 void Threads::shutdown_vm_agents() { 3372 // Send any Agent_OnUnload notifications 3373 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS; 3374 extern struct JavaVM_ main_vm; 3375 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 3376 3377 // Find the Agent_OnUnload function. 3378 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) { 3379 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t, 3380 hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index])); 3381 3382 // Invoke the Agent_OnUnload function 3383 if (unload_entry != NULL) { 3384 JavaThread* thread = JavaThread::current(); 3385 ThreadToNativeFromVM ttn(thread); 3386 HandleMark hm(thread); 3387 (*unload_entry)(&main_vm); 3388 break; 3389 } 3390 } 3391 } 3392 } 3393 3394 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries 3395 // Invokes JVM_OnLoad 3396 void Threads::create_vm_init_libraries() { 3397 extern struct JavaVM_ main_vm; 3398 AgentLibrary* agent; 3399 3400 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) { 3401 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); 3402 3403 if (on_load_entry != NULL) { 3404 // Invoke the JVM_OnLoad function 3405 JavaThread* thread = JavaThread::current(); 3406 ThreadToNativeFromVM ttn(thread); 3407 HandleMark hm(thread); 3408 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); 3409 if (err != JNI_OK) { 3410 vm_exit_during_initialization("-Xrun library failed to init", agent->name()); 3411 } 3412 } else { 3413 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name()); 3414 } 3415 } 3416 } 3417 3418 // Last thread running calls java.lang.Shutdown.shutdown() 3419 void JavaThread::invoke_shutdown_hooks() { 3420 HandleMark hm(this); 3421 3422 // We could get here with a pending exception, if so clear it now. 3423 if (this->has_pending_exception()) { 3424 this->clear_pending_exception(); 3425 } 3426 3427 EXCEPTION_MARK; 3428 klassOop k = 3429 SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(), 3430 THREAD); 3431 if (k != NULL) { 3432 // SystemDictionary::resolve_or_null will return null if there was 3433 // an exception. If we cannot load the Shutdown class, just don't 3434 // call Shutdown.shutdown() at all. This will mean the shutdown hooks 3435 // and finalizers (if runFinalizersOnExit is set) won't be run. 3436 // Note that if a shutdown hook was registered or runFinalizersOnExit 3437 // was called, the Shutdown class would have already been loaded 3438 // (Runtime.addShutdownHook and runFinalizersOnExit will load it). 3439 instanceKlassHandle shutdown_klass (THREAD, k); 3440 JavaValue result(T_VOID); 3441 JavaCalls::call_static(&result, 3442 shutdown_klass, 3443 vmSymbolHandles::shutdown_method_name(), 3444 vmSymbolHandles::void_method_signature(), 3445 THREAD); 3446 } 3447 CLEAR_PENDING_EXCEPTION; 3448 } 3449 3450 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when 3451 // the program falls off the end of main(). Another VM exit path is through 3452 // vm_exit() when the program calls System.exit() to return a value or when 3453 // there is a serious error in VM. The two shutdown paths are not exactly 3454 // the same, but they share Shutdown.shutdown() at Java level and before_exit() 3455 // and VM_Exit op at VM level. 3456 // 3457 // Shutdown sequence: 3458 // + Wait until we are the last non-daemon thread to execute 3459 // <-- every thing is still working at this moment --> 3460 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level 3461 // shutdown hooks, run finalizers if finalization-on-exit 3462 // + Call before_exit(), prepare for VM exit 3463 // > run VM level shutdown hooks (they are registered through JVM_OnExit(), 3464 // currently the only user of this mechanism is File.deleteOnExit()) 3465 // > stop flat profiler, StatSampler, watcher thread, CMS threads, 3466 // post thread end and vm death events to JVMTI, 3467 // stop signal thread 3468 // + Call JavaThread::exit(), it will: 3469 // > release JNI handle blocks, remove stack guard pages 3470 // > remove this thread from Threads list 3471 // <-- no more Java code from this thread after this point --> 3472 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop 3473 // the compiler threads at safepoint 3474 // <-- do not use anything that could get blocked by Safepoint --> 3475 // + Disable tracing at JNI/JVM barriers 3476 // + Set _vm_exited flag for threads that are still running native code 3477 // + Delete this thread 3478 // + Call exit_globals() 3479 // > deletes tty 3480 // > deletes PerfMemory resources 3481 // + Return to caller 3482 3483 bool Threads::destroy_vm() { 3484 JavaThread* thread = JavaThread::current(); 3485 3486 // Wait until we are the last non-daemon thread to execute 3487 { MutexLocker nu(Threads_lock); 3488 while (Threads::number_of_non_daemon_threads() > 1 ) 3489 // This wait should make safepoint checks, wait without a timeout, 3490 // and wait as a suspend-equivalent condition. 3491 // 3492 // Note: If the FlatProfiler is running and this thread is waiting 3493 // for another non-daemon thread to finish, then the FlatProfiler 3494 // is waiting for the external suspend request on this thread to 3495 // complete. wait_for_ext_suspend_completion() will eventually 3496 // timeout, but that takes time. Making this wait a suspend- 3497 // equivalent condition solves that timeout problem. 3498 // 3499 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0, 3500 Mutex::_as_suspend_equivalent_flag); 3501 } 3502 3503 // Hang forever on exit if we are reporting an error. 3504 if (ShowMessageBoxOnError && is_error_reported()) { 3505 os::infinite_sleep(); 3506 } 3507 3508 if (JDK_Version::is_jdk12x_version()) { 3509 // We are the last thread running, so check if finalizers should be run. 3510 // For 1.3 or later this is done in thread->invoke_shutdown_hooks() 3511 HandleMark rm(thread); 3512 Universe::run_finalizers_on_exit(); 3513 } else { 3514 // run Java level shutdown hooks 3515 thread->invoke_shutdown_hooks(); 3516 } 3517 3518 before_exit(thread); 3519 3520 thread->exit(true); 3521 3522 // Stop VM thread. 3523 { 3524 // 4945125 The vm thread comes to a safepoint during exit. 3525 // GC vm_operations can get caught at the safepoint, and the 3526 // heap is unparseable if they are caught. Grab the Heap_lock 3527 // to prevent this. The GC vm_operations will not be able to 3528 // queue until after the vm thread is dead. 3529 MutexLocker ml(Heap_lock); 3530 3531 VMThread::wait_for_vm_thread_exit(); 3532 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint"); 3533 VMThread::destroy(); 3534 } 3535 3536 // clean up ideal graph printers 3537 #if defined(COMPILER2) && !defined(PRODUCT) 3538 IdealGraphPrinter::clean_up(); 3539 #endif 3540 3541 // Now, all Java threads are gone except daemon threads. Daemon threads 3542 // running Java code or in VM are stopped by the Safepoint. However, 3543 // daemon threads executing native code are still running. But they 3544 // will be stopped at native=>Java/VM barriers. Note that we can't 3545 // simply kill or suspend them, as it is inherently deadlock-prone. 3546 3547 #ifndef PRODUCT 3548 // disable function tracing at JNI/JVM barriers 3549 TraceHPI = false; 3550 TraceJNICalls = false; 3551 TraceJVMCalls = false; 3552 TraceRuntimeCalls = false; 3553 #endif 3554 3555 VM_Exit::set_vm_exited(); 3556 3557 notify_vm_shutdown(); 3558 3559 delete thread; 3560 3561 // exit_globals() will delete tty 3562 exit_globals(); 3563 3564 return true; 3565 } 3566 3567 3568 jboolean Threads::is_supported_jni_version_including_1_1(jint version) { 3569 if (version == JNI_VERSION_1_1) return JNI_TRUE; 3570 return is_supported_jni_version(version); 3571 } 3572 3573 3574 jboolean Threads::is_supported_jni_version(jint version) { 3575 if (version == JNI_VERSION_1_2) return JNI_TRUE; 3576 if (version == JNI_VERSION_1_4) return JNI_TRUE; 3577 if (version == JNI_VERSION_1_6) return JNI_TRUE; 3578 return JNI_FALSE; 3579 } 3580 3581 3582 void Threads::add(JavaThread* p, bool force_daemon) { 3583 // The threads lock must be owned at this point 3584 assert_locked_or_safepoint(Threads_lock); 3585 p->set_next(_thread_list); 3586 _thread_list = p; 3587 _number_of_threads++; 3588 oop threadObj = p->threadObj(); 3589 bool daemon = true; 3590 // Bootstrapping problem: threadObj can be null for initial 3591 // JavaThread (or for threads attached via JNI) 3592 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) { 3593 _number_of_non_daemon_threads++; 3594 daemon = false; 3595 } 3596 3597 ThreadService::add_thread(p, daemon); 3598 3599 // Possible GC point. 3600 Events::log("Thread added: " INTPTR_FORMAT, p); 3601 } 3602 3603 void Threads::remove(JavaThread* p) { 3604 // Extra scope needed for Thread_lock, so we can check 3605 // that we do not remove thread without safepoint code notice 3606 { MutexLocker ml(Threads_lock); 3607 3608 assert(includes(p), "p must be present"); 3609 3610 JavaThread* current = _thread_list; 3611 JavaThread* prev = NULL; 3612 3613 while (current != p) { 3614 prev = current; 3615 current = current->next(); 3616 } 3617 3618 if (prev) { 3619 prev->set_next(current->next()); 3620 } else { 3621 _thread_list = p->next(); 3622 } 3623 _number_of_threads--; 3624 oop threadObj = p->threadObj(); 3625 bool daemon = true; 3626 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) { 3627 _number_of_non_daemon_threads--; 3628 daemon = false; 3629 3630 // Only one thread left, do a notify on the Threads_lock so a thread waiting 3631 // on destroy_vm will wake up. 3632 if (number_of_non_daemon_threads() == 1) 3633 Threads_lock->notify_all(); 3634 } 3635 ThreadService::remove_thread(p, daemon); 3636 3637 // Make sure that safepoint code disregard this thread. This is needed since 3638 // the thread might mess around with locks after this point. This can cause it 3639 // to do callbacks into the safepoint code. However, the safepoint code is not aware 3640 // of this thread since it is removed from the queue. 3641 p->set_terminated_value(); 3642 } // unlock Threads_lock 3643 3644 // Since Events::log uses a lock, we grab it outside the Threads_lock 3645 Events::log("Thread exited: " INTPTR_FORMAT, p); 3646 } 3647 3648 // Threads_lock must be held when this is called (or must be called during a safepoint) 3649 bool Threads::includes(JavaThread* p) { 3650 assert(Threads_lock->is_locked(), "sanity check"); 3651 ALL_JAVA_THREADS(q) { 3652 if (q == p ) { 3653 return true; 3654 } 3655 } 3656 return false; 3657 } 3658 3659 // Operations on the Threads list for GC. These are not explicitly locked, 3660 // but the garbage collector must provide a safe context for them to run. 3661 // In particular, these things should never be called when the Threads_lock 3662 // is held by some other thread. (Note: the Safepoint abstraction also 3663 // uses the Threads_lock to gurantee this property. It also makes sure that 3664 // all threads gets blocked when exiting or starting). 3665 3666 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) { 3667 ALL_JAVA_THREADS(p) { 3668 p->oops_do(f, cf); 3669 } 3670 VMThread::vm_thread()->oops_do(f, cf); 3671 } 3672 3673 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) { 3674 // Introduce a mechanism allowing parallel threads to claim threads as 3675 // root groups. Overhead should be small enough to use all the time, 3676 // even in sequential code. 3677 SharedHeap* sh = SharedHeap::heap(); 3678 bool is_par = (sh->n_par_threads() > 0); 3679 int cp = SharedHeap::heap()->strong_roots_parity(); 3680 ALL_JAVA_THREADS(p) { 3681 if (p->claim_oops_do(is_par, cp)) { 3682 p->oops_do(f, cf); 3683 } 3684 } 3685 VMThread* vmt = VMThread::vm_thread(); 3686 if (vmt->claim_oops_do(is_par, cp)) 3687 vmt->oops_do(f, cf); 3688 } 3689 3690 #ifndef SERIALGC 3691 // Used by ParallelScavenge 3692 void Threads::create_thread_roots_tasks(GCTaskQueue* q) { 3693 ALL_JAVA_THREADS(p) { 3694 q->enqueue(new ThreadRootsTask(p)); 3695 } 3696 q->enqueue(new ThreadRootsTask(VMThread::vm_thread())); 3697 } 3698 3699 // Used by Parallel Old 3700 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) { 3701 ALL_JAVA_THREADS(p) { 3702 q->enqueue(new ThreadRootsMarkingTask(p)); 3703 } 3704 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread())); 3705 } 3706 #endif // SERIALGC 3707 3708 void Threads::nmethods_do(CodeBlobClosure* cf) { 3709 ALL_JAVA_THREADS(p) { 3710 p->nmethods_do(cf); 3711 } 3712 VMThread::vm_thread()->nmethods_do(cf); 3713 } 3714 3715 void Threads::gc_epilogue() { 3716 ALL_JAVA_THREADS(p) { 3717 p->gc_epilogue(); 3718 } 3719 } 3720 3721 void Threads::gc_prologue() { 3722 ALL_JAVA_THREADS(p) { 3723 p->gc_prologue(); 3724 } 3725 } 3726 3727 void Threads::deoptimized_wrt_marked_nmethods() { 3728 ALL_JAVA_THREADS(p) { 3729 p->deoptimized_wrt_marked_nmethods(); 3730 } 3731 } 3732 3733 3734 // Get count Java threads that are waiting to enter the specified monitor. 3735 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count, 3736 address monitor, bool doLock) { 3737 assert(doLock || SafepointSynchronize::is_at_safepoint(), 3738 "must grab Threads_lock or be at safepoint"); 3739 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count); 3740 3741 int i = 0; 3742 { 3743 MutexLockerEx ml(doLock ? Threads_lock : NULL); 3744 ALL_JAVA_THREADS(p) { 3745 if (p->is_Compiler_thread()) continue; 3746 3747 address pending = (address)p->current_pending_monitor(); 3748 if (pending == monitor) { // found a match 3749 if (i < count) result->append(p); // save the first count matches 3750 i++; 3751 } 3752 } 3753 } 3754 return result; 3755 } 3756 3757 3758 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) { 3759 assert(doLock || 3760 Threads_lock->owned_by_self() || 3761 SafepointSynchronize::is_at_safepoint(), 3762 "must grab Threads_lock or be at safepoint"); 3763 3764 // NULL owner means not locked so we can skip the search 3765 if (owner == NULL) return NULL; 3766 3767 { 3768 MutexLockerEx ml(doLock ? Threads_lock : NULL); 3769 ALL_JAVA_THREADS(p) { 3770 // first, see if owner is the address of a Java thread 3771 if (owner == (address)p) return p; 3772 } 3773 } 3774 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled"); 3775 if (UseHeavyMonitors) return NULL; 3776 3777 // 3778 // If we didn't find a matching Java thread and we didn't force use of 3779 // heavyweight monitors, then the owner is the stack address of the 3780 // Lock Word in the owning Java thread's stack. 3781 // 3782 JavaThread* the_owner = NULL; 3783 { 3784 MutexLockerEx ml(doLock ? Threads_lock : NULL); 3785 ALL_JAVA_THREADS(q) { 3786 if (q->is_lock_owned(owner)) { 3787 the_owner = q; 3788 break; 3789 } 3790 } 3791 } 3792 assert(the_owner != NULL, "Did not find owning Java thread for lock word address"); 3793 return the_owner; 3794 } 3795 3796 // Threads::print_on() is called at safepoint by VM_PrintThreads operation. 3797 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) { 3798 char buf[32]; 3799 st->print_cr(os::local_time_string(buf, sizeof(buf))); 3800 3801 st->print_cr("Full thread dump %s (%s %s):", 3802 Abstract_VM_Version::vm_name(), 3803 Abstract_VM_Version::vm_release(), 3804 Abstract_VM_Version::vm_info_string() 3805 ); 3806 st->cr(); 3807 3808 #ifndef SERIALGC 3809 // Dump concurrent locks 3810 ConcurrentLocksDump concurrent_locks; 3811 if (print_concurrent_locks) { 3812 concurrent_locks.dump_at_safepoint(); 3813 } 3814 #endif // SERIALGC 3815 3816 ALL_JAVA_THREADS(p) { 3817 ResourceMark rm; 3818 p->print_on(st); 3819 if (print_stacks) { 3820 if (internal_format) { 3821 p->trace_stack(); 3822 } else { 3823 p->print_stack_on(st); 3824 } 3825 } 3826 st->cr(); 3827 #ifndef SERIALGC 3828 if (print_concurrent_locks) { 3829 concurrent_locks.print_locks_on(p, st); 3830 } 3831 #endif // SERIALGC 3832 } 3833 3834 VMThread::vm_thread()->print_on(st); 3835 st->cr(); 3836 Universe::heap()->print_gc_threads_on(st); 3837 WatcherThread* wt = WatcherThread::watcher_thread(); 3838 if (wt != NULL) wt->print_on(st); 3839 st->cr(); 3840 CompileBroker::print_compiler_threads_on(st); 3841 st->flush(); 3842 } 3843 3844 // Threads::print_on_error() is called by fatal error handler. It's possible 3845 // that VM is not at safepoint and/or current thread is inside signal handler. 3846 // Don't print stack trace, as the stack may not be walkable. Don't allocate 3847 // memory (even in resource area), it might deadlock the error handler. 3848 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) { 3849 bool found_current = false; 3850 st->print_cr("Java Threads: ( => current thread )"); 3851 ALL_JAVA_THREADS(thread) { 3852 bool is_current = (current == thread); 3853 found_current = found_current || is_current; 3854 3855 st->print("%s", is_current ? "=>" : " "); 3856 3857 st->print(PTR_FORMAT, thread); 3858 st->print(" "); 3859 thread->print_on_error(st, buf, buflen); 3860 st->cr(); 3861 } 3862 st->cr(); 3863 3864 st->print_cr("Other Threads:"); 3865 if (VMThread::vm_thread()) { 3866 bool is_current = (current == VMThread::vm_thread()); 3867 found_current = found_current || is_current; 3868 st->print("%s", current == VMThread::vm_thread() ? "=>" : " "); 3869 3870 st->print(PTR_FORMAT, VMThread::vm_thread()); 3871 st->print(" "); 3872 VMThread::vm_thread()->print_on_error(st, buf, buflen); 3873 st->cr(); 3874 } 3875 WatcherThread* wt = WatcherThread::watcher_thread(); 3876 if (wt != NULL) { 3877 bool is_current = (current == wt); 3878 found_current = found_current || is_current; 3879 st->print("%s", is_current ? "=>" : " "); 3880 3881 st->print(PTR_FORMAT, wt); 3882 st->print(" "); 3883 wt->print_on_error(st, buf, buflen); 3884 st->cr(); 3885 } 3886 if (!found_current) { 3887 st->cr(); 3888 st->print("=>" PTR_FORMAT " (exited) ", current); 3889 current->print_on_error(st, buf, buflen); 3890 st->cr(); 3891 } 3892 } 3893 3894 3895 // Lifecycle management for TSM ParkEvents. 3896 // ParkEvents are type-stable (TSM). 3897 // In our particular implementation they happen to be immortal. 3898 // 3899 // We manage concurrency on the FreeList with a CAS-based 3900 // detach-modify-reattach idiom that avoids the ABA problems 3901 // that would otherwise be present in a simple CAS-based 3902 // push-pop implementation. (push-one and pop-all) 3903 // 3904 // Caveat: Allocate() and Release() may be called from threads 3905 // other than the thread associated with the Event! 3906 // If we need to call Allocate() when running as the thread in 3907 // question then look for the PD calls to initialize native TLS. 3908 // Native TLS (Win32/Linux/Solaris) can only be initialized or 3909 // accessed by the associated thread. 3910 // See also pd_initialize(). 3911 // 3912 // Note that we could defer associating a ParkEvent with a thread 3913 // until the 1st time the thread calls park(). unpark() calls to 3914 // an unprovisioned thread would be ignored. The first park() call 3915 // for a thread would allocate and associate a ParkEvent and return 3916 // immediately. 3917 3918 volatile int ParkEvent::ListLock = 0 ; 3919 ParkEvent * volatile ParkEvent::FreeList = NULL ; 3920 3921 ParkEvent * ParkEvent::Allocate (Thread * t) { 3922 // In rare cases -- JVM_RawMonitor* operations -- we can find t == null. 3923 ParkEvent * ev ; 3924 3925 // Start by trying to recycle an existing but unassociated 3926 // ParkEvent from the global free list. 3927 for (;;) { 3928 ev = FreeList ; 3929 if (ev == NULL) break ; 3930 // 1: Detach - sequester or privatize the list 3931 // Tantamount to ev = Swap (&FreeList, NULL) 3932 if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) { 3933 continue ; 3934 } 3935 3936 // We've detached the list. The list in-hand is now 3937 // local to this thread. This thread can operate on the 3938 // list without risk of interference from other threads. 3939 // 2: Extract -- pop the 1st element from the list. 3940 ParkEvent * List = ev->FreeNext ; 3941 if (List == NULL) break ; 3942 for (;;) { 3943 // 3: Try to reattach the residual list 3944 guarantee (List != NULL, "invariant") ; 3945 ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ; 3946 if (Arv == NULL) break ; 3947 3948 // New nodes arrived. Try to detach the recent arrivals. 3949 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) { 3950 continue ; 3951 } 3952 guarantee (Arv != NULL, "invariant") ; 3953 // 4: Merge Arv into List 3954 ParkEvent * Tail = List ; 3955 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ; 3956 Tail->FreeNext = Arv ; 3957 } 3958 break ; 3959 } 3960 3961 if (ev != NULL) { 3962 guarantee (ev->AssociatedWith == NULL, "invariant") ; 3963 } else { 3964 // Do this the hard way -- materialize a new ParkEvent. 3965 // In rare cases an allocating thread might detach a long list -- 3966 // installing null into FreeList -- and then stall or be obstructed. 3967 // A 2nd thread calling Allocate() would see FreeList == null. 3968 // The list held privately by the 1st thread is unavailable to the 2nd thread. 3969 // In that case the 2nd thread would have to materialize a new ParkEvent, 3970 // even though free ParkEvents existed in the system. In this case we end up 3971 // with more ParkEvents in circulation than we need, but the race is 3972 // rare and the outcome is benign. Ideally, the # of extant ParkEvents 3973 // is equal to the maximum # of threads that existed at any one time. 3974 // Because of the race mentioned above, segments of the freelist 3975 // can be transiently inaccessible. At worst we may end up with the 3976 // # of ParkEvents in circulation slightly above the ideal. 3977 // Note that if we didn't have the TSM/immortal constraint, then 3978 // when reattaching, above, we could trim the list. 3979 ev = new ParkEvent () ; 3980 guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ; 3981 } 3982 ev->reset() ; // courtesy to caller 3983 ev->AssociatedWith = t ; // Associate ev with t 3984 ev->FreeNext = NULL ; 3985 return ev ; 3986 } 3987 3988 void ParkEvent::Release (ParkEvent * ev) { 3989 if (ev == NULL) return ; 3990 guarantee (ev->FreeNext == NULL , "invariant") ; 3991 ev->AssociatedWith = NULL ; 3992 for (;;) { 3993 // Push ev onto FreeList 3994 // The mechanism is "half" lock-free. 3995 ParkEvent * List = FreeList ; 3996 ev->FreeNext = List ; 3997 if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ; 3998 } 3999 } 4000 4001 // Override operator new and delete so we can ensure that the 4002 // least significant byte of ParkEvent addresses is 0. 4003 // Beware that excessive address alignment is undesirable 4004 // as it can result in D$ index usage imbalance as 4005 // well as bank access imbalance on Niagara-like platforms, 4006 // although Niagara's hash function should help. 4007 4008 void * ParkEvent::operator new (size_t sz) { 4009 return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ; 4010 } 4011 4012 void ParkEvent::operator delete (void * a) { 4013 // ParkEvents are type-stable and immortal ... 4014 ShouldNotReachHere(); 4015 } 4016 4017 4018 // 6399321 As a temporary measure we copied & modified the ParkEvent:: 4019 // allocate() and release() code for use by Parkers. The Parker:: forms 4020 // will eventually be removed as we consolide and shift over to ParkEvents 4021 // for both builtin synchronization and JSR166 operations. 4022 4023 volatile int Parker::ListLock = 0 ; 4024 Parker * volatile Parker::FreeList = NULL ; 4025 4026 Parker * Parker::Allocate (JavaThread * t) { 4027 guarantee (t != NULL, "invariant") ; 4028 Parker * p ; 4029 4030 // Start by trying to recycle an existing but unassociated 4031 // Parker from the global free list. 4032 for (;;) { 4033 p = FreeList ; 4034 if (p == NULL) break ; 4035 // 1: Detach 4036 // Tantamount to p = Swap (&FreeList, NULL) 4037 if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) { 4038 continue ; 4039 } 4040 4041 // We've detached the list. The list in-hand is now 4042 // local to this thread. This thread can operate on the 4043 // list without risk of interference from other threads. 4044 // 2: Extract -- pop the 1st element from the list. 4045 Parker * List = p->FreeNext ; 4046 if (List == NULL) break ; 4047 for (;;) { 4048 // 3: Try to reattach the residual list 4049 guarantee (List != NULL, "invariant") ; 4050 Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ; 4051 if (Arv == NULL) break ; 4052 4053 // New nodes arrived. Try to detach the recent arrivals. 4054 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) { 4055 continue ; 4056 } 4057 guarantee (Arv != NULL, "invariant") ; 4058 // 4: Merge Arv into List 4059 Parker * Tail = List ; 4060 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ; 4061 Tail->FreeNext = Arv ; 4062 } 4063 break ; 4064 } 4065 4066 if (p != NULL) { 4067 guarantee (p->AssociatedWith == NULL, "invariant") ; 4068 } else { 4069 // Do this the hard way -- materialize a new Parker.. 4070 // In rare cases an allocating thread might detach 4071 // a long list -- installing null into FreeList --and 4072 // then stall. Another thread calling Allocate() would see 4073 // FreeList == null and then invoke the ctor. In this case we 4074 // end up with more Parkers in circulation than we need, but 4075 // the race is rare and the outcome is benign. 4076 // Ideally, the # of extant Parkers is equal to the 4077 // maximum # of threads that existed at any one time. 4078 // Because of the race mentioned above, segments of the 4079 // freelist can be transiently inaccessible. At worst 4080 // we may end up with the # of Parkers in circulation 4081 // slightly above the ideal. 4082 p = new Parker() ; 4083 } 4084 p->AssociatedWith = t ; // Associate p with t 4085 p->FreeNext = NULL ; 4086 return p ; 4087 } 4088 4089 4090 void Parker::Release (Parker * p) { 4091 if (p == NULL) return ; 4092 guarantee (p->AssociatedWith != NULL, "invariant") ; 4093 guarantee (p->FreeNext == NULL , "invariant") ; 4094 p->AssociatedWith = NULL ; 4095 for (;;) { 4096 // Push p onto FreeList 4097 Parker * List = FreeList ; 4098 p->FreeNext = List ; 4099 if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ; 4100 } 4101 } 4102 4103 void Threads::verify() { 4104 ALL_JAVA_THREADS(p) { 4105 p->verify(); 4106 } 4107 VMThread* thread = VMThread::vm_thread(); 4108 if (thread != NULL) thread->verify(); 4109 }