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