1 /* 2 * Copyright (c) 1997, 2012, 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 "precompiled.hpp" 26 #include "classfile/classLoader.hpp" 27 #include "classfile/javaClasses.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "code/scopeDesc.hpp" 31 #include "compiler/compileBroker.hpp" 32 #include "interpreter/interpreter.hpp" 33 #include "interpreter/linkResolver.hpp" 34 #include "interpreter/oopMapCache.hpp" 35 #include "jvmtifiles/jvmtiEnv.hpp" 36 #include "memory/gcLocker.inline.hpp" 37 #include "memory/metaspaceShared.hpp" 38 #include "memory/oopFactory.hpp" 39 #include "memory/universe.inline.hpp" 40 #include "oops/instanceKlass.hpp" 41 #include "oops/objArrayOop.hpp" 42 #include "oops/oop.inline.hpp" 43 #include "oops/symbol.hpp" 44 #include "prims/jvm_misc.hpp" 45 #include "prims/jvmtiExport.hpp" 46 #include "prims/jvmtiThreadState.hpp" 47 #include "prims/privilegedStack.hpp" 48 #include "runtime/aprofiler.hpp" 49 #include "runtime/arguments.hpp" 50 #include "runtime/biasedLocking.hpp" 51 #include "runtime/deoptimization.hpp" 52 #include "runtime/fprofiler.hpp" 53 #include "runtime/frame.inline.hpp" 54 #include "runtime/init.hpp" 55 #include "runtime/interfaceSupport.hpp" 56 #include "runtime/java.hpp" 57 #include "runtime/javaCalls.hpp" 58 #include "runtime/jniPeriodicChecker.hpp" 59 #include "runtime/memprofiler.hpp" 60 #include "runtime/mutexLocker.hpp" 61 #include "runtime/objectMonitor.hpp" 62 #include "runtime/osThread.hpp" 63 #include "runtime/safepoint.hpp" 64 #include "runtime/sharedRuntime.hpp" 65 #include "runtime/statSampler.hpp" 66 #include "runtime/stubRoutines.hpp" 67 #include "runtime/task.hpp" 68 #include "runtime/threadCritical.hpp" 69 #include "runtime/threadLocalStorage.hpp" 70 #include "runtime/vframe.hpp" 71 #include "runtime/vframeArray.hpp" 72 #include "runtime/vframe_hp.hpp" 73 #include "runtime/vmThread.hpp" 74 #include "runtime/vm_operations.hpp" 75 #include "services/attachListener.hpp" 76 #include "services/management.hpp" 77 #include "services/memTracker.hpp" 78 #include "services/threadService.hpp" 79 #include "trace/traceEventTypes.hpp" 80 #include "utilities/defaultStream.hpp" 81 #include "utilities/dtrace.hpp" 82 #include "utilities/events.hpp" 83 #include "utilities/preserveException.hpp" 84 #ifdef TARGET_OS_FAMILY_linux 85 # include "os_linux.inline.hpp" 86 # include "thread_linux.inline.hpp" 87 #endif 88 #ifdef TARGET_OS_FAMILY_solaris 89 # include "os_solaris.inline.hpp" 90 # include "thread_solaris.inline.hpp" 91 #endif 92 #ifdef TARGET_OS_FAMILY_windows 93 # include "os_windows.inline.hpp" 94 # include "thread_windows.inline.hpp" 95 #endif 96 #ifdef TARGET_OS_FAMILY_bsd 97 # include "os_bsd.inline.hpp" 98 # include "thread_bsd.inline.hpp" 99 #endif 100 #ifndef SERIALGC 101 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp" 102 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp" 103 #include "gc_implementation/parallelScavenge/pcTasks.hpp" 104 #endif 105 #ifdef COMPILER1 106 #include "c1/c1_Compiler.hpp" 107 #endif 108 #ifdef COMPILER2 109 #include "opto/c2compiler.hpp" 110 #include "opto/idealGraphPrinter.hpp" 111 #endif 112 113 #ifdef DTRACE_ENABLED 114 115 // Only bother with this argument setup if dtrace is available 116 117 #ifndef USDT2 118 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin); 119 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end); 120 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t, 121 intptr_t, intptr_t, bool); 122 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t, 123 intptr_t, intptr_t, bool); 124 125 #define DTRACE_THREAD_PROBE(probe, javathread) \ 126 { \ 127 ResourceMark rm(this); \ 128 int len = 0; \ 129 const char* name = (javathread)->get_thread_name(); \ 130 len = strlen(name); \ 131 HS_DTRACE_PROBE5(hotspot, thread__##probe, \ 132 name, len, \ 133 java_lang_Thread::thread_id((javathread)->threadObj()), \ 134 (javathread)->osthread()->thread_id(), \ 135 java_lang_Thread::is_daemon((javathread)->threadObj())); \ 136 } 137 138 #else /* USDT2 */ 139 140 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_PROBE_START 141 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_PROBE_STOP 142 143 #define DTRACE_THREAD_PROBE(probe, javathread) \ 144 { \ 145 ResourceMark rm(this); \ 146 int len = 0; \ 147 const char* name = (javathread)->get_thread_name(); \ 148 len = strlen(name); \ 149 HOTSPOT_THREAD_PROBE_##probe( /* probe = start, stop */ \ 150 (char *) name, len, \ 151 java_lang_Thread::thread_id((javathread)->threadObj()), \ 152 (uintptr_t) (javathread)->osthread()->thread_id(), \ 153 java_lang_Thread::is_daemon((javathread)->threadObj())); \ 154 } 155 156 #endif /* USDT2 */ 157 158 #else // ndef DTRACE_ENABLED 159 160 #define DTRACE_THREAD_PROBE(probe, javathread) 161 162 #endif // ndef DTRACE_ENABLED 163 164 165 // Class hierarchy 166 // - Thread 167 // - VMThread 168 // - WatcherThread 169 // - ConcurrentMarkSweepThread 170 // - JavaThread 171 // - CompilerThread 172 173 // ======= Thread ======== 174 // Support for forcing alignment of thread objects for biased locking 175 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) { 176 if (UseBiasedLocking) { 177 const int alignment = markOopDesc::biased_lock_alignment; 178 size_t aligned_size = size + (alignment - sizeof(intptr_t)); 179 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC) 180 : AllocateHeap(aligned_size, flags, CURRENT_PC, 181 AllocFailStrategy::RETURN_NULL); 182 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment); 183 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <= 184 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size), 185 "JavaThread alignment code overflowed allocated storage"); 186 if (TraceBiasedLocking) { 187 if (aligned_addr != real_malloc_addr) 188 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT, 189 real_malloc_addr, aligned_addr); 190 } 191 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr; 192 return aligned_addr; 193 } else { 194 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC) 195 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL); 196 } 197 } 198 199 void Thread::operator delete(void* p) { 200 if (UseBiasedLocking) { 201 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address; 202 FreeHeap(real_malloc_addr, mtThread); 203 } else { 204 FreeHeap(p, mtThread); 205 } 206 } 207 208 209 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread, 210 // JavaThread 211 212 213 Thread::Thread() { 214 // stack and get_thread 215 set_stack_base(NULL); 216 set_stack_size(0); 217 set_self_raw_id(0); 218 set_lgrp_id(-1); 219 220 // allocated data structures 221 set_osthread(NULL); 222 set_resource_area(new (mtThread)ResourceArea()); 223 set_handle_area(new (mtThread) HandleArea(NULL)); 224 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(300, true)); 225 set_active_handles(NULL); 226 set_free_handle_block(NULL); 227 set_last_handle_mark(NULL); 228 229 // This initial value ==> never claimed. 230 _oops_do_parity = 0; 231 232 // the handle mark links itself to last_handle_mark 233 new HandleMark(this); 234 235 // plain initialization 236 debug_only(_owned_locks = NULL;) 237 debug_only(_allow_allocation_count = 0;) 238 NOT_PRODUCT(_allow_safepoint_count = 0;) 239 NOT_PRODUCT(_skip_gcalot = false;) 240 CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;) 241 _jvmti_env_iteration_count = 0; 242 set_allocated_bytes(0); 243 set_trace_buffer(NULL); 244 _vm_operation_started_count = 0; 245 _vm_operation_completed_count = 0; 246 _current_pending_monitor = NULL; 247 _current_pending_monitor_is_from_java = true; 248 _current_waiting_monitor = NULL; 249 _num_nested_signal = 0; 250 omFreeList = NULL ; 251 omFreeCount = 0 ; 252 omFreeProvision = 32 ; 253 omInUseList = NULL ; 254 omInUseCount = 0 ; 255 256 #ifdef ASSERT 257 _visited_for_critical_count = false; 258 #endif 259 260 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true); 261 _suspend_flags = 0; 262 263 // thread-specific hashCode stream generator state - Marsaglia shift-xor form 264 _hashStateX = os::random() ; 265 _hashStateY = 842502087 ; 266 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ; 267 _hashStateW = 273326509 ; 268 269 _OnTrap = 0 ; 270 _schedctl = NULL ; 271 _Stalled = 0 ; 272 _TypeTag = 0x2BAD ; 273 274 // Many of the following fields are effectively final - immutable 275 // Note that nascent threads can't use the Native Monitor-Mutex 276 // construct until the _MutexEvent is initialized ... 277 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents 278 // we might instead use a stack of ParkEvents that we could provision on-demand. 279 // The stack would act as a cache to avoid calls to ParkEvent::Allocate() 280 // and ::Release() 281 _ParkEvent = ParkEvent::Allocate (this) ; 282 _SleepEvent = ParkEvent::Allocate (this) ; 283 _MutexEvent = ParkEvent::Allocate (this) ; 284 _MuxEvent = ParkEvent::Allocate (this) ; 285 286 #ifdef CHECK_UNHANDLED_OOPS 287 if (CheckUnhandledOops) { 288 _unhandled_oops = new UnhandledOops(this); 289 } 290 #endif // CHECK_UNHANDLED_OOPS 291 #ifdef ASSERT 292 if (UseBiasedLocking) { 293 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed"); 294 assert(this == _real_malloc_address || 295 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment), 296 "bug in forced alignment of thread objects"); 297 } 298 #endif /* ASSERT */ 299 } 300 301 void Thread::initialize_thread_local_storage() { 302 // Note: Make sure this method only calls 303 // non-blocking operations. Otherwise, it might not work 304 // with the thread-startup/safepoint interaction. 305 306 // During Java thread startup, safepoint code should allow this 307 // method to complete because it may need to allocate memory to 308 // store information for the new thread. 309 310 // initialize structure dependent on thread local storage 311 ThreadLocalStorage::set_thread(this); 312 } 313 314 void Thread::record_stack_base_and_size() { 315 set_stack_base(os::current_stack_base()); 316 set_stack_size(os::current_stack_size()); 317 // CR 7190089: on Solaris, primordial thread's stack is adjusted 318 // in initialize_thread(). Without the adjustment, stack size is 319 // incorrect if stack is set to unlimited (ulimit -s unlimited). 320 // So far, only Solaris has real implementation of initialize_thread(). 321 // 322 // set up any platform-specific state. 323 os::initialize_thread(this); 324 325 #if INCLUDE_NMT 326 // record thread's native stack, stack grows downward 327 address stack_low_addr = stack_base() - stack_size(); 328 MemTracker::record_thread_stack(stack_low_addr, stack_size(), this, 329 CURRENT_PC); 330 #endif // INCLUDE_NMT 331 } 332 333 334 Thread::~Thread() { 335 // Reclaim the objectmonitors from the omFreeList of the moribund thread. 336 ObjectSynchronizer::omFlush (this) ; 337 338 // stack_base can be NULL if the thread is never started or exited before 339 // record_stack_base_and_size called. Although, we would like to ensure 340 // that all started threads do call record_stack_base_and_size(), there is 341 // not proper way to enforce that. 342 #if INCLUDE_NMT 343 if (_stack_base != NULL) { 344 address low_stack_addr = stack_base() - stack_size(); 345 MemTracker::release_thread_stack(low_stack_addr, stack_size(), this); 346 #ifdef ASSERT 347 set_stack_base(NULL); 348 #endif 349 } 350 #endif // INCLUDE_NMT 351 352 // deallocate data structures 353 delete resource_area(); 354 // since the handle marks are using the handle area, we have to deallocated the root 355 // handle mark before deallocating the thread's handle area, 356 assert(last_handle_mark() != NULL, "check we have an element"); 357 delete last_handle_mark(); 358 assert(last_handle_mark() == NULL, "check we have reached the end"); 359 360 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads. 361 // We NULL out the fields for good hygiene. 362 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ; 363 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ; 364 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ; 365 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ; 366 367 delete handle_area(); 368 delete metadata_handles(); 369 370 // osthread() can be NULL, if creation of thread failed. 371 if (osthread() != NULL) os::free_thread(osthread()); 372 373 delete _SR_lock; 374 375 // clear thread local storage if the Thread is deleting itself 376 if (this == Thread::current()) { 377 ThreadLocalStorage::set_thread(NULL); 378 } else { 379 // In the case where we're not the current thread, invalidate all the 380 // caches in case some code tries to get the current thread or the 381 // thread that was destroyed, and gets stale information. 382 ThreadLocalStorage::invalidate_all(); 383 } 384 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();) 385 } 386 387 // NOTE: dummy function for assertion purpose. 388 void Thread::run() { 389 ShouldNotReachHere(); 390 } 391 392 #ifdef ASSERT 393 // Private method to check for dangling thread pointer 394 void check_for_dangling_thread_pointer(Thread *thread) { 395 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(), 396 "possibility of dangling Thread pointer"); 397 } 398 #endif 399 400 401 #ifndef PRODUCT 402 // Tracing method for basic thread operations 403 void Thread::trace(const char* msg, const Thread* const thread) { 404 if (!TraceThreadEvents) return; 405 ResourceMark rm; 406 ThreadCritical tc; 407 const char *name = "non-Java thread"; 408 int prio = -1; 409 if (thread->is_Java_thread() 410 && !thread->is_Compiler_thread()) { 411 // The Threads_lock must be held to get information about 412 // this thread but may not be in some situations when 413 // tracing thread events. 414 bool release_Threads_lock = false; 415 if (!Threads_lock->owned_by_self()) { 416 Threads_lock->lock(); 417 release_Threads_lock = true; 418 } 419 JavaThread* jt = (JavaThread *)thread; 420 name = (char *)jt->get_thread_name(); 421 oop thread_oop = jt->threadObj(); 422 if (thread_oop != NULL) { 423 prio = java_lang_Thread::priority(thread_oop); 424 } 425 if (release_Threads_lock) { 426 Threads_lock->unlock(); 427 } 428 } 429 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio); 430 } 431 #endif 432 433 434 ThreadPriority Thread::get_priority(const Thread* const thread) { 435 trace("get priority", thread); 436 ThreadPriority priority; 437 // Can return an error! 438 (void)os::get_priority(thread, priority); 439 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found"); 440 return priority; 441 } 442 443 void Thread::set_priority(Thread* thread, ThreadPriority priority) { 444 trace("set priority", thread); 445 debug_only(check_for_dangling_thread_pointer(thread);) 446 // Can return an error! 447 (void)os::set_priority(thread, priority); 448 } 449 450 451 void Thread::start(Thread* thread) { 452 trace("start", thread); 453 // Start is different from resume in that its safety is guaranteed by context or 454 // being called from a Java method synchronized on the Thread object. 455 if (!DisableStartThread) { 456 if (thread->is_Java_thread()) { 457 // Initialize the thread state to RUNNABLE before starting this thread. 458 // Can not set it after the thread started because we do not know the 459 // exact thread state at that time. It could be in MONITOR_WAIT or 460 // in SLEEPING or some other state. 461 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(), 462 java_lang_Thread::RUNNABLE); 463 } 464 os::start_thread(thread); 465 } 466 } 467 468 // Enqueue a VM_Operation to do the job for us - sometime later 469 void Thread::send_async_exception(oop java_thread, oop java_throwable) { 470 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable); 471 VMThread::execute(vm_stop); 472 } 473 474 475 // 476 // Check if an external suspend request has completed (or has been 477 // cancelled). Returns true if the thread is externally suspended and 478 // false otherwise. 479 // 480 // The bits parameter returns information about the code path through 481 // the routine. Useful for debugging: 482 // 483 // set in is_ext_suspend_completed(): 484 // 0x00000001 - routine was entered 485 // 0x00000010 - routine return false at end 486 // 0x00000100 - thread exited (return false) 487 // 0x00000200 - suspend request cancelled (return false) 488 // 0x00000400 - thread suspended (return true) 489 // 0x00001000 - thread is in a suspend equivalent state (return true) 490 // 0x00002000 - thread is native and walkable (return true) 491 // 0x00004000 - thread is native_trans and walkable (needed retry) 492 // 493 // set in wait_for_ext_suspend_completion(): 494 // 0x00010000 - routine was entered 495 // 0x00020000 - suspend request cancelled before loop (return false) 496 // 0x00040000 - thread suspended before loop (return true) 497 // 0x00080000 - suspend request cancelled in loop (return false) 498 // 0x00100000 - thread suspended in loop (return true) 499 // 0x00200000 - suspend not completed during retry loop (return false) 500 // 501 502 // Helper class for tracing suspend wait debug bits. 503 // 504 // 0x00000100 indicates that the target thread exited before it could 505 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and 506 // 0x00080000 each indicate a cancelled suspend request so they don't 507 // count as wait failures either. 508 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000) 509 510 class TraceSuspendDebugBits : public StackObj { 511 private: 512 JavaThread * jt; 513 bool is_wait; 514 bool called_by_wait; // meaningful when !is_wait 515 uint32_t * bits; 516 517 public: 518 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait, 519 uint32_t *_bits) { 520 jt = _jt; 521 is_wait = _is_wait; 522 called_by_wait = _called_by_wait; 523 bits = _bits; 524 } 525 526 ~TraceSuspendDebugBits() { 527 if (!is_wait) { 528 #if 1 529 // By default, don't trace bits for is_ext_suspend_completed() calls. 530 // That trace is very chatty. 531 return; 532 #else 533 if (!called_by_wait) { 534 // If tracing for is_ext_suspend_completed() is enabled, then only 535 // trace calls to it from wait_for_ext_suspend_completion() 536 return; 537 } 538 #endif 539 } 540 541 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) { 542 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) { 543 MutexLocker ml(Threads_lock); // needed for get_thread_name() 544 ResourceMark rm; 545 546 tty->print_cr( 547 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)", 548 jt->get_thread_name(), *bits); 549 550 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed"); 551 } 552 } 553 } 554 }; 555 #undef DEBUG_FALSE_BITS 556 557 558 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) { 559 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits); 560 561 bool did_trans_retry = false; // only do thread_in_native_trans retry once 562 bool do_trans_retry; // flag to force the retry 563 564 *bits |= 0x00000001; 565 566 do { 567 do_trans_retry = false; 568 569 if (is_exiting()) { 570 // Thread is in the process of exiting. This is always checked 571 // first to reduce the risk of dereferencing a freed JavaThread. 572 *bits |= 0x00000100; 573 return false; 574 } 575 576 if (!is_external_suspend()) { 577 // Suspend request is cancelled. This is always checked before 578 // is_ext_suspended() to reduce the risk of a rogue resume 579 // confusing the thread that made the suspend request. 580 *bits |= 0x00000200; 581 return false; 582 } 583 584 if (is_ext_suspended()) { 585 // thread is suspended 586 *bits |= 0x00000400; 587 return true; 588 } 589 590 // Now that we no longer do hard suspends of threads running 591 // native code, the target thread can be changing thread state 592 // while we are in this routine: 593 // 594 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked 595 // 596 // We save a copy of the thread state as observed at this moment 597 // and make our decision about suspend completeness based on the 598 // copy. This closes the race where the thread state is seen as 599 // _thread_in_native_trans in the if-thread_blocked check, but is 600 // seen as _thread_blocked in if-thread_in_native_trans check. 601 JavaThreadState save_state = thread_state(); 602 603 if (save_state == _thread_blocked && is_suspend_equivalent()) { 604 // If the thread's state is _thread_blocked and this blocking 605 // condition is known to be equivalent to a suspend, then we can 606 // consider the thread to be externally suspended. This means that 607 // the code that sets _thread_blocked has been modified to do 608 // self-suspension if the blocking condition releases. We also 609 // used to check for CONDVAR_WAIT here, but that is now covered by 610 // the _thread_blocked with self-suspension check. 611 // 612 // Return true since we wouldn't be here unless there was still an 613 // external suspend request. 614 *bits |= 0x00001000; 615 return true; 616 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) { 617 // Threads running native code will self-suspend on native==>VM/Java 618 // transitions. If its stack is walkable (should always be the case 619 // unless this function is called before the actual java_suspend() 620 // call), then the wait is done. 621 *bits |= 0x00002000; 622 return true; 623 } else if (!called_by_wait && !did_trans_retry && 624 save_state == _thread_in_native_trans && 625 frame_anchor()->walkable()) { 626 // The thread is transitioning from thread_in_native to another 627 // thread state. check_safepoint_and_suspend_for_native_trans() 628 // will force the thread to self-suspend. If it hasn't gotten 629 // there yet we may have caught the thread in-between the native 630 // code check above and the self-suspend. Lucky us. If we were 631 // called by wait_for_ext_suspend_completion(), then it 632 // will be doing the retries so we don't have to. 633 // 634 // Since we use the saved thread state in the if-statement above, 635 // there is a chance that the thread has already transitioned to 636 // _thread_blocked by the time we get here. In that case, we will 637 // make a single unnecessary pass through the logic below. This 638 // doesn't hurt anything since we still do the trans retry. 639 640 *bits |= 0x00004000; 641 642 // Once the thread leaves thread_in_native_trans for another 643 // thread state, we break out of this retry loop. We shouldn't 644 // need this flag to prevent us from getting back here, but 645 // sometimes paranoia is good. 646 did_trans_retry = true; 647 648 // We wait for the thread to transition to a more usable state. 649 for (int i = 1; i <= SuspendRetryCount; i++) { 650 // We used to do an "os::yield_all(i)" call here with the intention 651 // that yielding would increase on each retry. However, the parameter 652 // is ignored on Linux which means the yield didn't scale up. Waiting 653 // on the SR_lock below provides a much more predictable scale up for 654 // the delay. It also provides a simple/direct point to check for any 655 // safepoint requests from the VMThread 656 657 // temporarily drops SR_lock while doing wait with safepoint check 658 // (if we're a JavaThread - the WatcherThread can also call this) 659 // and increase delay with each retry 660 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); 661 662 // check the actual thread state instead of what we saved above 663 if (thread_state() != _thread_in_native_trans) { 664 // the thread has transitioned to another thread state so 665 // try all the checks (except this one) one more time. 666 do_trans_retry = true; 667 break; 668 } 669 } // end retry loop 670 671 672 } 673 } while (do_trans_retry); 674 675 *bits |= 0x00000010; 676 return false; 677 } 678 679 // 680 // Wait for an external suspend request to complete (or be cancelled). 681 // Returns true if the thread is externally suspended and false otherwise. 682 // 683 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay, 684 uint32_t *bits) { 685 TraceSuspendDebugBits tsdb(this, true /* is_wait */, 686 false /* !called_by_wait */, bits); 687 688 // local flag copies to minimize SR_lock hold time 689 bool is_suspended; 690 bool pending; 691 uint32_t reset_bits; 692 693 // set a marker so is_ext_suspend_completed() knows we are the caller 694 *bits |= 0x00010000; 695 696 // We use reset_bits to reinitialize the bits value at the top of 697 // each retry loop. This allows the caller to make use of any 698 // unused bits for their own marking purposes. 699 reset_bits = *bits; 700 701 { 702 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 703 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, 704 delay, bits); 705 pending = is_external_suspend(); 706 } 707 // must release SR_lock to allow suspension to complete 708 709 if (!pending) { 710 // A cancelled suspend request is the only false return from 711 // is_ext_suspend_completed() that keeps us from entering the 712 // retry loop. 713 *bits |= 0x00020000; 714 return false; 715 } 716 717 if (is_suspended) { 718 *bits |= 0x00040000; 719 return true; 720 } 721 722 for (int i = 1; i <= retries; i++) { 723 *bits = reset_bits; // reinit to only track last retry 724 725 // We used to do an "os::yield_all(i)" call here with the intention 726 // that yielding would increase on each retry. However, the parameter 727 // is ignored on Linux which means the yield didn't scale up. Waiting 728 // on the SR_lock below provides a much more predictable scale up for 729 // the delay. It also provides a simple/direct point to check for any 730 // safepoint requests from the VMThread 731 732 { 733 MutexLocker ml(SR_lock()); 734 // wait with safepoint check (if we're a JavaThread - the WatcherThread 735 // can also call this) and increase delay with each retry 736 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); 737 738 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, 739 delay, bits); 740 741 // It is possible for the external suspend request to be cancelled 742 // (by a resume) before the actual suspend operation is completed. 743 // Refresh our local copy to see if we still need to wait. 744 pending = is_external_suspend(); 745 } 746 747 if (!pending) { 748 // A cancelled suspend request is the only false return from 749 // is_ext_suspend_completed() that keeps us from staying in the 750 // retry loop. 751 *bits |= 0x00080000; 752 return false; 753 } 754 755 if (is_suspended) { 756 *bits |= 0x00100000; 757 return true; 758 } 759 } // end retry loop 760 761 // thread did not suspend after all our retries 762 *bits |= 0x00200000; 763 return false; 764 } 765 766 #ifndef PRODUCT 767 void JavaThread::record_jump(address target, address instr, const char* file, int line) { 768 769 // This should not need to be atomic as the only way for simultaneous 770 // updates is via interrupts. Even then this should be rare or non-existant 771 // and we don't care that much anyway. 772 773 int index = _jmp_ring_index; 774 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1); 775 _jmp_ring[index]._target = (intptr_t) target; 776 _jmp_ring[index]._instruction = (intptr_t) instr; 777 _jmp_ring[index]._file = file; 778 _jmp_ring[index]._line = line; 779 } 780 #endif /* PRODUCT */ 781 782 // Called by flat profiler 783 // Callers have already called wait_for_ext_suspend_completion 784 // The assertion for that is currently too complex to put here: 785 bool JavaThread::profile_last_Java_frame(frame* _fr) { 786 bool gotframe = false; 787 // self suspension saves needed state. 788 if (has_last_Java_frame() && _anchor.walkable()) { 789 *_fr = pd_last_frame(); 790 gotframe = true; 791 } 792 return gotframe; 793 } 794 795 void Thread::interrupt(Thread* thread) { 796 trace("interrupt", thread); 797 debug_only(check_for_dangling_thread_pointer(thread);) 798 os::interrupt(thread); 799 } 800 801 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) { 802 trace("is_interrupted", thread); 803 debug_only(check_for_dangling_thread_pointer(thread);) 804 // Note: If clear_interrupted==false, this simply fetches and 805 // returns the value of the field osthread()->interrupted(). 806 return os::is_interrupted(thread, clear_interrupted); 807 } 808 809 810 // GC Support 811 bool Thread::claim_oops_do_par_case(int strong_roots_parity) { 812 jint thread_parity = _oops_do_parity; 813 if (thread_parity != strong_roots_parity) { 814 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity); 815 if (res == thread_parity) { 816 return true; 817 } else { 818 guarantee(res == strong_roots_parity, "Or else what?"); 819 assert(SharedHeap::heap()->workers()->active_workers() > 0, 820 "Should only fail when parallel."); 821 return false; 822 } 823 } 824 assert(SharedHeap::heap()->workers()->active_workers() > 0, 825 "Should only fail when parallel."); 826 return false; 827 } 828 829 void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) { 830 active_handles()->oops_do(f); 831 // Do oop for ThreadShadow 832 f->do_oop((oop*)&_pending_exception); 833 handle_area()->oops_do(f); 834 } 835 836 void Thread::nmethods_do(CodeBlobClosure* cf) { 837 // no nmethods in a generic thread... 838 } 839 840 void Thread::metadata_do(void f(Metadata*)) { 841 if (metadata_handles() != NULL) { 842 for (int i = 0; i< metadata_handles()->length(); i++) { 843 f(metadata_handles()->at(i)); 844 } 845 } 846 } 847 848 void Thread::print_on(outputStream* st) const { 849 // get_priority assumes osthread initialized 850 if (osthread() != NULL) { 851 int os_prio; 852 if (os::get_native_priority(this, &os_prio) == OS_OK) { 853 st->print("os_prio=%d ", os_prio); 854 } 855 st->print("tid=" INTPTR_FORMAT " ", this); 856 osthread()->print_on(st); 857 } 858 debug_only(if (WizardMode) print_owned_locks_on(st);) 859 } 860 861 // Thread::print_on_error() is called by fatal error handler. Don't use 862 // any lock or allocate memory. 863 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const { 864 if (is_VM_thread()) st->print("VMThread"); 865 else if (is_Compiler_thread()) st->print("CompilerThread"); 866 else if (is_Java_thread()) st->print("JavaThread"); 867 else if (is_GC_task_thread()) st->print("GCTaskThread"); 868 else if (is_Watcher_thread()) st->print("WatcherThread"); 869 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread"); 870 else st->print("Thread"); 871 872 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]", 873 _stack_base - _stack_size, _stack_base); 874 875 if (osthread()) { 876 st->print(" [id=%d]", osthread()->thread_id()); 877 } 878 } 879 880 #ifdef ASSERT 881 void Thread::print_owned_locks_on(outputStream* st) const { 882 Monitor *cur = _owned_locks; 883 if (cur == NULL) { 884 st->print(" (no locks) "); 885 } else { 886 st->print_cr(" Locks owned:"); 887 while(cur) { 888 cur->print_on(st); 889 cur = cur->next(); 890 } 891 } 892 } 893 894 static int ref_use_count = 0; 895 896 bool Thread::owns_locks_but_compiled_lock() const { 897 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { 898 if (cur != Compile_lock) return true; 899 } 900 return false; 901 } 902 903 904 #endif 905 906 #ifndef PRODUCT 907 908 // The flag: potential_vm_operation notifies if this particular safepoint state could potential 909 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that 910 // no threads which allow_vm_block's are held 911 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) { 912 // Check if current thread is allowed to block at a safepoint 913 if (!(_allow_safepoint_count == 0)) 914 fatal("Possible safepoint reached by thread that does not allow it"); 915 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) { 916 fatal("LEAF method calling lock?"); 917 } 918 919 #ifdef ASSERT 920 if (potential_vm_operation && is_Java_thread() 921 && !Universe::is_bootstrapping()) { 922 // Make sure we do not hold any locks that the VM thread also uses. 923 // This could potentially lead to deadlocks 924 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { 925 // Threads_lock is special, since the safepoint synchronization will not start before this is 926 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock, 927 // since it is used to transfer control between JavaThreads and the VMThread 928 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first! 929 if ( (cur->allow_vm_block() && 930 cur != Threads_lock && 931 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation 932 cur != VMOperationRequest_lock && 933 cur != VMOperationQueue_lock) || 934 cur->rank() == Mutex::special) { 935 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name()); 936 } 937 } 938 } 939 940 if (GCALotAtAllSafepoints) { 941 // We could enter a safepoint here and thus have a gc 942 InterfaceSupport::check_gc_alot(); 943 } 944 #endif 945 } 946 #endif 947 948 bool Thread::is_in_stack(address adr) const { 949 assert(Thread::current() == this, "is_in_stack can only be called from current thread"); 950 address end = os::current_stack_pointer(); 951 // Allow non Java threads to call this without stack_base 952 if (_stack_base == NULL) return true; 953 if (stack_base() >= adr && adr >= end) return true; 954 955 return false; 956 } 957 958 959 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter 960 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being 961 // used for compilation in the future. If that change is made, the need for these methods 962 // should be revisited, and they should be removed if possible. 963 964 bool Thread::is_lock_owned(address adr) const { 965 return on_local_stack(adr); 966 } 967 968 bool Thread::set_as_starting_thread() { 969 // NOTE: this must be called inside the main thread. 970 return os::create_main_thread((JavaThread*)this); 971 } 972 973 static void initialize_class(Symbol* class_name, TRAPS) { 974 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK); 975 InstanceKlass::cast(klass)->initialize(CHECK); 976 } 977 978 979 // Creates the initial ThreadGroup 980 static Handle create_initial_thread_group(TRAPS) { 981 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH); 982 instanceKlassHandle klass (THREAD, k); 983 984 Handle system_instance = klass->allocate_instance_handle(CHECK_NH); 985 { 986 JavaValue result(T_VOID); 987 JavaCalls::call_special(&result, 988 system_instance, 989 klass, 990 vmSymbols::object_initializer_name(), 991 vmSymbols::void_method_signature(), 992 CHECK_NH); 993 } 994 Universe::set_system_thread_group(system_instance()); 995 996 Handle main_instance = klass->allocate_instance_handle(CHECK_NH); 997 { 998 JavaValue result(T_VOID); 999 Handle string = java_lang_String::create_from_str("main", CHECK_NH); 1000 JavaCalls::call_special(&result, 1001 main_instance, 1002 klass, 1003 vmSymbols::object_initializer_name(), 1004 vmSymbols::threadgroup_string_void_signature(), 1005 system_instance, 1006 string, 1007 CHECK_NH); 1008 } 1009 return main_instance; 1010 } 1011 1012 // Creates the initial Thread 1013 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) { 1014 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL); 1015 instanceKlassHandle klass (THREAD, k); 1016 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL); 1017 1018 java_lang_Thread::set_thread(thread_oop(), thread); 1019 java_lang_Thread::set_priority(thread_oop(), NormPriority); 1020 thread->set_threadObj(thread_oop()); 1021 1022 Handle string = java_lang_String::create_from_str("main", CHECK_NULL); 1023 1024 JavaValue result(T_VOID); 1025 JavaCalls::call_special(&result, thread_oop, 1026 klass, 1027 vmSymbols::object_initializer_name(), 1028 vmSymbols::threadgroup_string_void_signature(), 1029 thread_group, 1030 string, 1031 CHECK_NULL); 1032 return thread_oop(); 1033 } 1034 1035 static void call_initializeSystemClass(TRAPS) { 1036 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK); 1037 instanceKlassHandle klass (THREAD, k); 1038 1039 JavaValue result(T_VOID); 1040 JavaCalls::call_static(&result, klass, vmSymbols::initializeSystemClass_name(), 1041 vmSymbols::void_method_signature(), CHECK); 1042 } 1043 1044 char java_runtime_name[128] = ""; 1045 char java_runtime_version[128] = ""; 1046 1047 // extract the JRE name from sun.misc.Version.java_runtime_name 1048 static const char* get_java_runtime_name(TRAPS) { 1049 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(), 1050 Handle(), Handle(), CHECK_AND_CLEAR_NULL); 1051 fieldDescriptor fd; 1052 bool found = k != NULL && 1053 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(), 1054 vmSymbols::string_signature(), &fd); 1055 if (found) { 1056 oop name_oop = k->java_mirror()->obj_field(fd.offset()); 1057 if (name_oop == NULL) 1058 return NULL; 1059 const char* name = java_lang_String::as_utf8_string(name_oop, 1060 java_runtime_name, 1061 sizeof(java_runtime_name)); 1062 return name; 1063 } else { 1064 return NULL; 1065 } 1066 } 1067 1068 // extract the JRE version from sun.misc.Version.java_runtime_version 1069 static const char* get_java_runtime_version(TRAPS) { 1070 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(), 1071 Handle(), Handle(), CHECK_AND_CLEAR_NULL); 1072 fieldDescriptor fd; 1073 bool found = k != NULL && 1074 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_version_name(), 1075 vmSymbols::string_signature(), &fd); 1076 if (found) { 1077 oop name_oop = k->java_mirror()->obj_field(fd.offset()); 1078 if (name_oop == NULL) 1079 return NULL; 1080 const char* name = java_lang_String::as_utf8_string(name_oop, 1081 java_runtime_version, 1082 sizeof(java_runtime_version)); 1083 return name; 1084 } else { 1085 return NULL; 1086 } 1087 } 1088 1089 // General purpose hook into Java code, run once when the VM is initialized. 1090 // The Java library method itself may be changed independently from the VM. 1091 static void call_postVMInitHook(TRAPS) { 1092 Klass* k = SystemDictionary::PostVMInitHook_klass(); 1093 instanceKlassHandle klass (THREAD, k); 1094 if (klass.not_null()) { 1095 JavaValue result(T_VOID); 1096 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(), 1097 vmSymbols::void_method_signature(), 1098 CHECK); 1099 } 1100 } 1101 1102 static void reset_vm_info_property(TRAPS) { 1103 // the vm info string 1104 ResourceMark rm(THREAD); 1105 const char *vm_info = VM_Version::vm_info_string(); 1106 1107 // java.lang.System class 1108 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK); 1109 instanceKlassHandle klass (THREAD, k); 1110 1111 // setProperty arguments 1112 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK); 1113 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK); 1114 1115 // return value 1116 JavaValue r(T_OBJECT); 1117 1118 // public static String setProperty(String key, String value); 1119 JavaCalls::call_static(&r, 1120 klass, 1121 vmSymbols::setProperty_name(), 1122 vmSymbols::string_string_string_signature(), 1123 key_str, 1124 value_str, 1125 CHECK); 1126 } 1127 1128 1129 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) { 1130 assert(thread_group.not_null(), "thread group should be specified"); 1131 assert(threadObj() == NULL, "should only create Java thread object once"); 1132 1133 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK); 1134 instanceKlassHandle klass (THREAD, k); 1135 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); 1136 1137 java_lang_Thread::set_thread(thread_oop(), this); 1138 java_lang_Thread::set_priority(thread_oop(), NormPriority); 1139 set_threadObj(thread_oop()); 1140 1141 JavaValue result(T_VOID); 1142 if (thread_name != NULL) { 1143 Handle name = java_lang_String::create_from_str(thread_name, CHECK); 1144 // Thread gets assigned specified name and null target 1145 JavaCalls::call_special(&result, 1146 thread_oop, 1147 klass, 1148 vmSymbols::object_initializer_name(), 1149 vmSymbols::threadgroup_string_void_signature(), 1150 thread_group, // Argument 1 1151 name, // Argument 2 1152 THREAD); 1153 } else { 1154 // Thread gets assigned name "Thread-nnn" and null target 1155 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) 1156 JavaCalls::call_special(&result, 1157 thread_oop, 1158 klass, 1159 vmSymbols::object_initializer_name(), 1160 vmSymbols::threadgroup_runnable_void_signature(), 1161 thread_group, // Argument 1 1162 Handle(), // Argument 2 1163 THREAD); 1164 } 1165 1166 1167 if (daemon) { 1168 java_lang_Thread::set_daemon(thread_oop()); 1169 } 1170 1171 if (HAS_PENDING_EXCEPTION) { 1172 return; 1173 } 1174 1175 KlassHandle group(this, SystemDictionary::ThreadGroup_klass()); 1176 Handle threadObj(this, this->threadObj()); 1177 1178 JavaCalls::call_special(&result, 1179 thread_group, 1180 group, 1181 vmSymbols::add_method_name(), 1182 vmSymbols::thread_void_signature(), 1183 threadObj, // Arg 1 1184 THREAD); 1185 1186 1187 } 1188 1189 // NamedThread -- non-JavaThread subclasses with multiple 1190 // uniquely named instances should derive from this. 1191 NamedThread::NamedThread() : Thread() { 1192 _name = NULL; 1193 _processed_thread = NULL; 1194 } 1195 1196 NamedThread::~NamedThread() { 1197 if (_name != NULL) { 1198 FREE_C_HEAP_ARRAY(char, _name, mtThread); 1199 _name = NULL; 1200 } 1201 } 1202 1203 void NamedThread::set_name(const char* format, ...) { 1204 guarantee(_name == NULL, "Only get to set name once."); 1205 _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread); 1206 guarantee(_name != NULL, "alloc failure"); 1207 va_list ap; 1208 va_start(ap, format); 1209 jio_vsnprintf(_name, max_name_len, format, ap); 1210 va_end(ap); 1211 } 1212 1213 // ======= WatcherThread ======== 1214 1215 // The watcher thread exists to simulate timer interrupts. It should 1216 // be replaced by an abstraction over whatever native support for 1217 // timer interrupts exists on the platform. 1218 1219 WatcherThread* WatcherThread::_watcher_thread = NULL; 1220 volatile bool WatcherThread::_should_terminate = false; 1221 1222 WatcherThread::WatcherThread() : Thread() { 1223 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread"); 1224 if (os::create_thread(this, os::watcher_thread)) { 1225 _watcher_thread = this; 1226 1227 // Set the watcher thread to the highest OS priority which should not be 1228 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY 1229 // is created. The only normal thread using this priority is the reference 1230 // handler thread, which runs for very short intervals only. 1231 // If the VMThread's priority is not lower than the WatcherThread profiling 1232 // will be inaccurate. 1233 os::set_priority(this, MaxPriority); 1234 if (!DisableStartThread) { 1235 os::start_thread(this); 1236 } 1237 } 1238 } 1239 1240 void WatcherThread::run() { 1241 assert(this == watcher_thread(), "just checking"); 1242 1243 this->record_stack_base_and_size(); 1244 this->initialize_thread_local_storage(); 1245 this->set_active_handles(JNIHandleBlock::allocate_block()); 1246 while(!_should_terminate) { 1247 assert(watcher_thread() == Thread::current(), "thread consistency check"); 1248 assert(watcher_thread() == this, "thread consistency check"); 1249 1250 // Calculate how long it'll be until the next PeriodicTask work 1251 // should be done, and sleep that amount of time. 1252 size_t time_to_wait = PeriodicTask::time_to_wait(); 1253 1254 // we expect this to timeout - we only ever get unparked when 1255 // we should terminate 1256 { 1257 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */); 1258 1259 jlong prev_time = os::javaTimeNanos(); 1260 for (;;) { 1261 int res= _SleepEvent->park(time_to_wait); 1262 if (res == OS_TIMEOUT || _should_terminate) 1263 break; 1264 // spurious wakeup of some kind 1265 jlong now = os::javaTimeNanos(); 1266 time_to_wait -= (now - prev_time) / 1000000; 1267 if (time_to_wait <= 0) 1268 break; 1269 prev_time = now; 1270 } 1271 } 1272 1273 if (is_error_reported()) { 1274 // A fatal error has happened, the error handler(VMError::report_and_die) 1275 // should abort JVM after creating an error log file. However in some 1276 // rare cases, the error handler itself might deadlock. Here we try to 1277 // kill JVM if the fatal error handler fails to abort in 2 minutes. 1278 // 1279 // This code is in WatcherThread because WatcherThread wakes up 1280 // periodically so the fatal error handler doesn't need to do anything; 1281 // also because the WatcherThread is less likely to crash than other 1282 // threads. 1283 1284 for (;;) { 1285 if (!ShowMessageBoxOnError 1286 && (OnError == NULL || OnError[0] == '\0') 1287 && Arguments::abort_hook() == NULL) { 1288 os::sleep(this, 2 * 60 * 1000, false); 1289 fdStream err(defaultStream::output_fd()); 1290 err.print_raw_cr("# [ timer expired, abort... ]"); 1291 // skip atexit/vm_exit/vm_abort hooks 1292 os::die(); 1293 } 1294 1295 // Wake up 5 seconds later, the fatal handler may reset OnError or 1296 // ShowMessageBoxOnError when it is ready to abort. 1297 os::sleep(this, 5 * 1000, false); 1298 } 1299 } 1300 1301 PeriodicTask::real_time_tick(time_to_wait); 1302 1303 // If we have no more tasks left due to dynamic disenrollment, 1304 // shut down the thread since we don't currently support dynamic enrollment 1305 if (PeriodicTask::num_tasks() == 0) { 1306 _should_terminate = true; 1307 } 1308 } 1309 1310 // Signal that it is terminated 1311 { 1312 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag); 1313 _watcher_thread = NULL; 1314 Terminator_lock->notify(); 1315 } 1316 1317 // Thread destructor usually does this.. 1318 ThreadLocalStorage::set_thread(NULL); 1319 } 1320 1321 void WatcherThread::start() { 1322 if (watcher_thread() == NULL) { 1323 _should_terminate = false; 1324 // Create the single instance of WatcherThread 1325 new WatcherThread(); 1326 } 1327 } 1328 1329 void WatcherThread::stop() { 1330 // it is ok to take late safepoints here, if needed 1331 MutexLocker mu(Terminator_lock); 1332 _should_terminate = true; 1333 OrderAccess::fence(); // ensure WatcherThread sees update in main loop 1334 1335 Thread* watcher = watcher_thread(); 1336 if (watcher != NULL) 1337 watcher->_SleepEvent->unpark(); 1338 1339 while(watcher_thread() != NULL) { 1340 // This wait should make safepoint checks, wait without a timeout, 1341 // and wait as a suspend-equivalent condition. 1342 // 1343 // Note: If the FlatProfiler is running, then this thread is waiting 1344 // for the WatcherThread to terminate and the WatcherThread, via the 1345 // FlatProfiler task, is waiting for the external suspend request on 1346 // this thread to complete. wait_for_ext_suspend_completion() will 1347 // eventually timeout, but that takes time. Making this wait a 1348 // suspend-equivalent condition solves that timeout problem. 1349 // 1350 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0, 1351 Mutex::_as_suspend_equivalent_flag); 1352 } 1353 } 1354 1355 void WatcherThread::print_on(outputStream* st) const { 1356 st->print("\"%s\" ", name()); 1357 Thread::print_on(st); 1358 st->cr(); 1359 } 1360 1361 // ======= JavaThread ======== 1362 1363 // A JavaThread is a normal Java thread 1364 1365 void JavaThread::initialize() { 1366 // Initialize fields 1367 1368 // Set the claimed par_id to -1 (ie not claiming any par_ids) 1369 set_claimed_par_id(-1); 1370 1371 set_saved_exception_pc(NULL); 1372 set_threadObj(NULL); 1373 _anchor.clear(); 1374 set_entry_point(NULL); 1375 set_jni_functions(jni_functions()); 1376 set_callee_target(NULL); 1377 set_vm_result(NULL); 1378 set_vm_result_2(NULL); 1379 set_vframe_array_head(NULL); 1380 set_vframe_array_last(NULL); 1381 set_deferred_locals(NULL); 1382 set_deopt_mark(NULL); 1383 set_deopt_nmethod(NULL); 1384 clear_must_deopt_id(); 1385 set_monitor_chunks(NULL); 1386 set_next(NULL); 1387 set_thread_state(_thread_new); 1388 #if INCLUDE_NMT 1389 set_recorder(NULL); 1390 #endif 1391 _terminated = _not_terminated; 1392 _privileged_stack_top = NULL; 1393 _array_for_gc = NULL; 1394 _suspend_equivalent = false; 1395 _in_deopt_handler = 0; 1396 _doing_unsafe_access = false; 1397 _stack_guard_state = stack_guard_unused; 1398 _exception_oop = NULL; 1399 _exception_pc = 0; 1400 _exception_handler_pc = 0; 1401 _is_method_handle_return = 0; 1402 _jvmti_thread_state= NULL; 1403 _should_post_on_exceptions_flag = JNI_FALSE; 1404 _jvmti_get_loaded_classes_closure = NULL; 1405 _interp_only_mode = 0; 1406 _special_runtime_exit_condition = _no_async_condition; 1407 _pending_async_exception = NULL; 1408 _is_compiling = false; 1409 _thread_stat = NULL; 1410 _thread_stat = new ThreadStatistics(); 1411 _blocked_on_compilation = false; 1412 _jni_active_critical = 0; 1413 _do_not_unlock_if_synchronized = false; 1414 _cached_monitor_info = NULL; 1415 _parker = Parker::Allocate(this) ; 1416 1417 #ifndef PRODUCT 1418 _jmp_ring_index = 0; 1419 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) { 1420 record_jump(NULL, NULL, NULL, 0); 1421 } 1422 #endif /* PRODUCT */ 1423 1424 set_thread_profiler(NULL); 1425 if (FlatProfiler::is_active()) { 1426 // This is where we would decide to either give each thread it's own profiler 1427 // or use one global one from FlatProfiler, 1428 // or up to some count of the number of profiled threads, etc. 1429 ThreadProfiler* pp = new ThreadProfiler(); 1430 pp->engage(); 1431 set_thread_profiler(pp); 1432 } 1433 1434 // Setup safepoint state info for this thread 1435 ThreadSafepointState::create(this); 1436 1437 debug_only(_java_call_counter = 0); 1438 1439 // JVMTI PopFrame support 1440 _popframe_condition = popframe_inactive; 1441 _popframe_preserved_args = NULL; 1442 _popframe_preserved_args_size = 0; 1443 1444 pd_initialize(); 1445 } 1446 1447 #ifndef SERIALGC 1448 SATBMarkQueueSet JavaThread::_satb_mark_queue_set; 1449 DirtyCardQueueSet JavaThread::_dirty_card_queue_set; 1450 #endif // !SERIALGC 1451 1452 JavaThread::JavaThread(bool is_attaching_via_jni) : 1453 Thread() 1454 #ifndef SERIALGC 1455 , _satb_mark_queue(&_satb_mark_queue_set), 1456 _dirty_card_queue(&_dirty_card_queue_set) 1457 #endif // !SERIALGC 1458 { 1459 initialize(); 1460 if (is_attaching_via_jni) { 1461 _jni_attach_state = _attaching_via_jni; 1462 } else { 1463 _jni_attach_state = _not_attaching_via_jni; 1464 } 1465 assert(_deferred_card_mark.is_empty(), "Default MemRegion ctor"); 1466 _safepoint_visible = false; 1467 } 1468 1469 bool JavaThread::reguard_stack(address cur_sp) { 1470 if (_stack_guard_state != stack_guard_yellow_disabled) { 1471 return true; // Stack already guarded or guard pages not needed. 1472 } 1473 1474 if (register_stack_overflow()) { 1475 // For those architectures which have separate register and 1476 // memory stacks, we must check the register stack to see if 1477 // it has overflowed. 1478 return false; 1479 } 1480 1481 // Java code never executes within the yellow zone: the latter is only 1482 // there to provoke an exception during stack banging. If java code 1483 // is executing there, either StackShadowPages should be larger, or 1484 // some exception code in c1, c2 or the interpreter isn't unwinding 1485 // when it should. 1486 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages"); 1487 1488 enable_stack_yellow_zone(); 1489 return true; 1490 } 1491 1492 bool JavaThread::reguard_stack(void) { 1493 return reguard_stack(os::current_stack_pointer()); 1494 } 1495 1496 1497 void JavaThread::block_if_vm_exited() { 1498 if (_terminated == _vm_exited) { 1499 // _vm_exited is set at safepoint, and Threads_lock is never released 1500 // we will block here forever 1501 Threads_lock->lock_without_safepoint_check(); 1502 ShouldNotReachHere(); 1503 } 1504 } 1505 1506 1507 // Remove this ifdef when C1 is ported to the compiler interface. 1508 static void compiler_thread_entry(JavaThread* thread, TRAPS); 1509 1510 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : 1511 Thread() 1512 #ifndef SERIALGC 1513 , _satb_mark_queue(&_satb_mark_queue_set), 1514 _dirty_card_queue(&_dirty_card_queue_set) 1515 #endif // !SERIALGC 1516 { 1517 if (TraceThreadEvents) { 1518 tty->print_cr("creating thread %p", this); 1519 } 1520 initialize(); 1521 _jni_attach_state = _not_attaching_via_jni; 1522 set_entry_point(entry_point); 1523 // Create the native thread itself. 1524 // %note runtime_23 1525 os::ThreadType thr_type = os::java_thread; 1526 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread : 1527 os::java_thread; 1528 os::create_thread(this, thr_type, stack_sz); 1529 _safepoint_visible = false; 1530 // The _osthread may be NULL here because we ran out of memory (too many threads active). 1531 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller 1532 // may hold a lock and all locks must be unlocked before throwing the exception (throwing 1533 // the exception consists of creating the exception object & initializing it, initialization 1534 // will leave the VM via a JavaCall and then all locks must be unlocked). 1535 // 1536 // The thread is still suspended when we reach here. Thread must be explicit started 1537 // by creator! Furthermore, the thread must also explicitly be added to the Threads list 1538 // by calling Threads:add. The reason why this is not done here, is because the thread 1539 // object must be fully initialized (take a look at JVM_Start) 1540 } 1541 1542 JavaThread::~JavaThread() { 1543 if (TraceThreadEvents) { 1544 tty->print_cr("terminate thread %p", this); 1545 } 1546 1547 // By now, this thread should already be invisible to safepoint, 1548 // and its per-thread recorder also collected. 1549 assert(!is_safepoint_visible(), "wrong state"); 1550 #if INCLUDE_NMT 1551 assert(get_recorder() == NULL, "Already collected"); 1552 #endif // INCLUDE_NMT 1553 1554 // JSR166 -- return the parker to the free list 1555 Parker::Release(_parker); 1556 _parker = NULL ; 1557 1558 // Free any remaining previous UnrollBlock 1559 vframeArray* old_array = vframe_array_last(); 1560 1561 if (old_array != NULL) { 1562 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); 1563 old_array->set_unroll_block(NULL); 1564 delete old_info; 1565 delete old_array; 1566 } 1567 1568 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals(); 1569 if (deferred != NULL) { 1570 // This can only happen if thread is destroyed before deoptimization occurs. 1571 assert(deferred->length() != 0, "empty array!"); 1572 do { 1573 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0); 1574 deferred->remove_at(0); 1575 // individual jvmtiDeferredLocalVariableSet are CHeapObj's 1576 delete dlv; 1577 } while (deferred->length() != 0); 1578 delete deferred; 1579 } 1580 1581 // All Java related clean up happens in exit 1582 ThreadSafepointState::destroy(this); 1583 if (_thread_profiler != NULL) delete _thread_profiler; 1584 if (_thread_stat != NULL) delete _thread_stat; 1585 } 1586 1587 1588 // The first routine called by a new Java thread 1589 void JavaThread::run() { 1590 // initialize thread-local alloc buffer related fields 1591 this->initialize_tlab(); 1592 1593 // used to test validitity of stack trace backs 1594 this->record_base_of_stack_pointer(); 1595 1596 // Record real stack base and size. 1597 this->record_stack_base_and_size(); 1598 1599 // Initialize thread local storage; set before calling MutexLocker 1600 this->initialize_thread_local_storage(); 1601 1602 this->create_stack_guard_pages(); 1603 1604 this->cache_global_variables(); 1605 1606 // Thread is now sufficient initialized to be handled by the safepoint code as being 1607 // in the VM. Change thread state from _thread_new to _thread_in_vm 1608 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm); 1609 1610 assert(JavaThread::current() == this, "sanity check"); 1611 assert(!Thread::current()->owns_locks(), "sanity check"); 1612 1613 DTRACE_THREAD_PROBE(start, this); 1614 1615 // This operation might block. We call that after all safepoint checks for a new thread has 1616 // been completed. 1617 this->set_active_handles(JNIHandleBlock::allocate_block()); 1618 1619 if (JvmtiExport::should_post_thread_life()) { 1620 JvmtiExport::post_thread_start(this); 1621 } 1622 1623 EVENT_BEGIN(TraceEventThreadStart, event); 1624 EVENT_COMMIT(event, 1625 EVENT_SET(event, javalangthread, java_lang_Thread::thread_id(this->threadObj()))); 1626 1627 // We call another function to do the rest so we are sure that the stack addresses used 1628 // from there will be lower than the stack base just computed 1629 thread_main_inner(); 1630 1631 // Note, thread is no longer valid at this point! 1632 } 1633 1634 1635 void JavaThread::thread_main_inner() { 1636 assert(JavaThread::current() == this, "sanity check"); 1637 assert(this->threadObj() != NULL, "just checking"); 1638 1639 // Execute thread entry point unless this thread has a pending exception 1640 // or has been stopped before starting. 1641 // Note: Due to JVM_StopThread we can have pending exceptions already! 1642 if (!this->has_pending_exception() && 1643 !java_lang_Thread::is_stillborn(this->threadObj())) { 1644 { 1645 ResourceMark rm(this); 1646 this->set_native_thread_name(this->get_thread_name()); 1647 } 1648 HandleMark hm(this); 1649 this->entry_point()(this, this); 1650 } 1651 1652 DTRACE_THREAD_PROBE(stop, this); 1653 1654 this->exit(false); 1655 delete this; 1656 } 1657 1658 1659 static void ensure_join(JavaThread* thread) { 1660 // We do not need to grap the Threads_lock, since we are operating on ourself. 1661 Handle threadObj(thread, thread->threadObj()); 1662 assert(threadObj.not_null(), "java thread object must exist"); 1663 ObjectLocker lock(threadObj, thread); 1664 // Ignore pending exception (ThreadDeath), since we are exiting anyway 1665 thread->clear_pending_exception(); 1666 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. 1667 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED); 1668 // Clear the native thread instance - this makes isAlive return false and allows the join() 1669 // to complete once we've done the notify_all below 1670 java_lang_Thread::set_thread(threadObj(), NULL); 1671 lock.notify_all(thread); 1672 // Ignore pending exception (ThreadDeath), since we are exiting anyway 1673 thread->clear_pending_exception(); 1674 } 1675 1676 1677 // For any new cleanup additions, please check to see if they need to be applied to 1678 // cleanup_failed_attach_current_thread as well. 1679 void JavaThread::exit(bool destroy_vm, ExitType exit_type) { 1680 assert(this == JavaThread::current(), "thread consistency check"); 1681 if (!InitializeJavaLangSystem) return; 1682 1683 HandleMark hm(this); 1684 Handle uncaught_exception(this, this->pending_exception()); 1685 this->clear_pending_exception(); 1686 Handle threadObj(this, this->threadObj()); 1687 assert(threadObj.not_null(), "Java thread object should be created"); 1688 1689 if (get_thread_profiler() != NULL) { 1690 get_thread_profiler()->disengage(); 1691 ResourceMark rm; 1692 get_thread_profiler()->print(get_thread_name()); 1693 } 1694 1695 1696 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place 1697 { 1698 EXCEPTION_MARK; 1699 1700 CLEAR_PENDING_EXCEPTION; 1701 } 1702 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This 1703 // has to be fixed by a runtime query method 1704 if (!destroy_vm || JDK_Version::is_jdk12x_version()) { 1705 // JSR-166: change call from from ThreadGroup.uncaughtException to 1706 // java.lang.Thread.dispatchUncaughtException 1707 if (uncaught_exception.not_null()) { 1708 Handle group(this, java_lang_Thread::threadGroup(threadObj())); 1709 { 1710 EXCEPTION_MARK; 1711 // Check if the method Thread.dispatchUncaughtException() exists. If so 1712 // call it. Otherwise we have an older library without the JSR-166 changes, 1713 // so call ThreadGroup.uncaughtException() 1714 KlassHandle recvrKlass(THREAD, threadObj->klass()); 1715 CallInfo callinfo; 1716 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass()); 1717 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass, 1718 vmSymbols::dispatchUncaughtException_name(), 1719 vmSymbols::throwable_void_signature(), 1720 KlassHandle(), false, false, THREAD); 1721 CLEAR_PENDING_EXCEPTION; 1722 methodHandle method = callinfo.selected_method(); 1723 if (method.not_null()) { 1724 JavaValue result(T_VOID); 1725 JavaCalls::call_virtual(&result, 1726 threadObj, thread_klass, 1727 vmSymbols::dispatchUncaughtException_name(), 1728 vmSymbols::throwable_void_signature(), 1729 uncaught_exception, 1730 THREAD); 1731 } else { 1732 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass()); 1733 JavaValue result(T_VOID); 1734 JavaCalls::call_virtual(&result, 1735 group, thread_group, 1736 vmSymbols::uncaughtException_name(), 1737 vmSymbols::thread_throwable_void_signature(), 1738 threadObj, // Arg 1 1739 uncaught_exception, // Arg 2 1740 THREAD); 1741 } 1742 if (HAS_PENDING_EXCEPTION) { 1743 ResourceMark rm(this); 1744 jio_fprintf(defaultStream::error_stream(), 1745 "\nException: %s thrown from the UncaughtExceptionHandler" 1746 " in thread \"%s\"\n", 1747 Klass::cast(pending_exception()->klass())->external_name(), 1748 get_thread_name()); 1749 CLEAR_PENDING_EXCEPTION; 1750 } 1751 } 1752 } 1753 1754 // Called before the java thread exit since we want to read info 1755 // from java_lang_Thread object 1756 EVENT_BEGIN(TraceEventThreadEnd, event); 1757 EVENT_COMMIT(event, 1758 EVENT_SET(event, javalangthread, java_lang_Thread::thread_id(this->threadObj()))); 1759 1760 // Call after last event on thread 1761 EVENT_THREAD_EXIT(this); 1762 1763 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during 1764 // the execution of the method. If that is not enough, then we don't really care. Thread.stop 1765 // is deprecated anyhow. 1766 { int count = 3; 1767 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) { 1768 EXCEPTION_MARK; 1769 JavaValue result(T_VOID); 1770 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass()); 1771 JavaCalls::call_virtual(&result, 1772 threadObj, thread_klass, 1773 vmSymbols::exit_method_name(), 1774 vmSymbols::void_method_signature(), 1775 THREAD); 1776 CLEAR_PENDING_EXCEPTION; 1777 } 1778 } 1779 1780 // notify JVMTI 1781 if (JvmtiExport::should_post_thread_life()) { 1782 JvmtiExport::post_thread_end(this); 1783 } 1784 1785 // We have notified the agents that we are exiting, before we go on, 1786 // we must check for a pending external suspend request and honor it 1787 // in order to not surprise the thread that made the suspend request. 1788 while (true) { 1789 { 1790 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1791 if (!is_external_suspend()) { 1792 set_terminated(_thread_exiting); 1793 ThreadService::current_thread_exiting(this); 1794 break; 1795 } 1796 // Implied else: 1797 // Things get a little tricky here. We have a pending external 1798 // suspend request, but we are holding the SR_lock so we 1799 // can't just self-suspend. So we temporarily drop the lock 1800 // and then self-suspend. 1801 } 1802 1803 ThreadBlockInVM tbivm(this); 1804 java_suspend_self(); 1805 1806 // We're done with this suspend request, but we have to loop around 1807 // and check again. Eventually we will get SR_lock without a pending 1808 // external suspend request and will be able to mark ourselves as 1809 // exiting. 1810 } 1811 // no more external suspends are allowed at this point 1812 } else { 1813 // before_exit() has already posted JVMTI THREAD_END events 1814 } 1815 1816 // Notify waiters on thread object. This has to be done after exit() is called 1817 // on the thread (if the thread is the last thread in a daemon ThreadGroup the 1818 // group should have the destroyed bit set before waiters are notified). 1819 ensure_join(this); 1820 assert(!this->has_pending_exception(), "ensure_join should have cleared"); 1821 1822 // 6282335 JNI DetachCurrentThread spec states that all Java monitors 1823 // held by this thread must be released. A detach operation must only 1824 // get here if there are no Java frames on the stack. Therefore, any 1825 // owned monitors at this point MUST be JNI-acquired monitors which are 1826 // pre-inflated and in the monitor cache. 1827 // 1828 // ensure_join() ignores IllegalThreadStateExceptions, and so does this. 1829 if (exit_type == jni_detach && JNIDetachReleasesMonitors) { 1830 assert(!this->has_last_Java_frame(), "detaching with Java frames?"); 1831 ObjectSynchronizer::release_monitors_owned_by_thread(this); 1832 assert(!this->has_pending_exception(), "release_monitors should have cleared"); 1833 } 1834 1835 // These things needs to be done while we are still a Java Thread. Make sure that thread 1836 // is in a consistent state, in case GC happens 1837 assert(_privileged_stack_top == NULL, "must be NULL when we get here"); 1838 1839 if (active_handles() != NULL) { 1840 JNIHandleBlock* block = active_handles(); 1841 set_active_handles(NULL); 1842 JNIHandleBlock::release_block(block); 1843 } 1844 1845 if (free_handle_block() != NULL) { 1846 JNIHandleBlock* block = free_handle_block(); 1847 set_free_handle_block(NULL); 1848 JNIHandleBlock::release_block(block); 1849 } 1850 1851 // These have to be removed while this is still a valid thread. 1852 remove_stack_guard_pages(); 1853 1854 if (UseTLAB) { 1855 tlab().make_parsable(true); // retire TLAB 1856 } 1857 1858 if (JvmtiEnv::environments_might_exist()) { 1859 JvmtiExport::cleanup_thread(this); 1860 } 1861 1862 #ifndef SERIALGC 1863 // We must flush G1-related buffers before removing a thread from 1864 // the list of active threads. 1865 if (UseG1GC) { 1866 flush_barrier_queues(); 1867 } 1868 #endif 1869 1870 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread 1871 Threads::remove(this); 1872 } 1873 1874 #ifndef SERIALGC 1875 // Flush G1-related queues. 1876 void JavaThread::flush_barrier_queues() { 1877 satb_mark_queue().flush(); 1878 dirty_card_queue().flush(); 1879 } 1880 1881 void JavaThread::initialize_queues() { 1882 assert(!SafepointSynchronize::is_at_safepoint(), 1883 "we should not be at a safepoint"); 1884 1885 ObjPtrQueue& satb_queue = satb_mark_queue(); 1886 SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set(); 1887 // The SATB queue should have been constructed with its active 1888 // field set to false. 1889 assert(!satb_queue.is_active(), "SATB queue should not be active"); 1890 assert(satb_queue.is_empty(), "SATB queue should be empty"); 1891 // If we are creating the thread during a marking cycle, we should 1892 // set the active field of the SATB queue to true. 1893 if (satb_queue_set.is_active()) { 1894 satb_queue.set_active(true); 1895 } 1896 1897 DirtyCardQueue& dirty_queue = dirty_card_queue(); 1898 // The dirty card queue should have been constructed with its 1899 // active field set to true. 1900 assert(dirty_queue.is_active(), "dirty card queue should be active"); 1901 } 1902 #endif // !SERIALGC 1903 1904 void JavaThread::cleanup_failed_attach_current_thread() { 1905 if (get_thread_profiler() != NULL) { 1906 get_thread_profiler()->disengage(); 1907 ResourceMark rm; 1908 get_thread_profiler()->print(get_thread_name()); 1909 } 1910 1911 if (active_handles() != NULL) { 1912 JNIHandleBlock* block = active_handles(); 1913 set_active_handles(NULL); 1914 JNIHandleBlock::release_block(block); 1915 } 1916 1917 if (free_handle_block() != NULL) { 1918 JNIHandleBlock* block = free_handle_block(); 1919 set_free_handle_block(NULL); 1920 JNIHandleBlock::release_block(block); 1921 } 1922 1923 // These have to be removed while this is still a valid thread. 1924 remove_stack_guard_pages(); 1925 1926 if (UseTLAB) { 1927 tlab().make_parsable(true); // retire TLAB, if any 1928 } 1929 1930 #ifndef SERIALGC 1931 if (UseG1GC) { 1932 flush_barrier_queues(); 1933 } 1934 #endif 1935 1936 Threads::remove(this); 1937 delete this; 1938 } 1939 1940 1941 1942 1943 JavaThread* JavaThread::active() { 1944 Thread* thread = ThreadLocalStorage::thread(); 1945 assert(thread != NULL, "just checking"); 1946 if (thread->is_Java_thread()) { 1947 return (JavaThread*) thread; 1948 } else { 1949 assert(thread->is_VM_thread(), "this must be a vm thread"); 1950 VM_Operation* op = ((VMThread*) thread)->vm_operation(); 1951 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread(); 1952 assert(ret->is_Java_thread(), "must be a Java thread"); 1953 return ret; 1954 } 1955 } 1956 1957 bool JavaThread::is_lock_owned(address adr) const { 1958 if (Thread::is_lock_owned(adr)) return true; 1959 1960 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { 1961 if (chunk->contains(adr)) return true; 1962 } 1963 1964 return false; 1965 } 1966 1967 1968 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) { 1969 chunk->set_next(monitor_chunks()); 1970 set_monitor_chunks(chunk); 1971 } 1972 1973 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) { 1974 guarantee(monitor_chunks() != NULL, "must be non empty"); 1975 if (monitor_chunks() == chunk) { 1976 set_monitor_chunks(chunk->next()); 1977 } else { 1978 MonitorChunk* prev = monitor_chunks(); 1979 while (prev->next() != chunk) prev = prev->next(); 1980 prev->set_next(chunk->next()); 1981 } 1982 } 1983 1984 // JVM support. 1985 1986 // Note: this function shouldn't block if it's called in 1987 // _thread_in_native_trans state (such as from 1988 // check_special_condition_for_native_trans()). 1989 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) { 1990 1991 if (has_last_Java_frame() && has_async_condition()) { 1992 // If we are at a polling page safepoint (not a poll return) 1993 // then we must defer async exception because live registers 1994 // will be clobbered by the exception path. Poll return is 1995 // ok because the call we a returning from already collides 1996 // with exception handling registers and so there is no issue. 1997 // (The exception handling path kills call result registers but 1998 // this is ok since the exception kills the result anyway). 1999 2000 if (is_at_poll_safepoint()) { 2001 // if the code we are returning to has deoptimized we must defer 2002 // the exception otherwise live registers get clobbered on the 2003 // exception path before deoptimization is able to retrieve them. 2004 // 2005 RegisterMap map(this, false); 2006 frame caller_fr = last_frame().sender(&map); 2007 assert(caller_fr.is_compiled_frame(), "what?"); 2008 if (caller_fr.is_deoptimized_frame()) { 2009 if (TraceExceptions) { 2010 ResourceMark rm; 2011 tty->print_cr("deferred async exception at compiled safepoint"); 2012 } 2013 return; 2014 } 2015 } 2016 } 2017 2018 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition(); 2019 if (condition == _no_async_condition) { 2020 // Conditions have changed since has_special_runtime_exit_condition() 2021 // was called: 2022 // - if we were here only because of an external suspend request, 2023 // then that was taken care of above (or cancelled) so we are done 2024 // - if we were here because of another async request, then it has 2025 // been cleared between the has_special_runtime_exit_condition() 2026 // and now so again we are done 2027 return; 2028 } 2029 2030 // Check for pending async. exception 2031 if (_pending_async_exception != NULL) { 2032 // Only overwrite an already pending exception, if it is not a threadDeath. 2033 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) { 2034 2035 // We cannot call Exceptions::_throw(...) here because we cannot block 2036 set_pending_exception(_pending_async_exception, __FILE__, __LINE__); 2037 2038 if (TraceExceptions) { 2039 ResourceMark rm; 2040 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this); 2041 if (has_last_Java_frame() ) { 2042 frame f = last_frame(); 2043 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp()); 2044 } 2045 tty->print_cr(" of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name()); 2046 } 2047 _pending_async_exception = NULL; 2048 clear_has_async_exception(); 2049 } 2050 } 2051 2052 if (check_unsafe_error && 2053 condition == _async_unsafe_access_error && !has_pending_exception()) { 2054 condition = _no_async_condition; // done 2055 switch (thread_state()) { 2056 case _thread_in_vm: 2057 { 2058 JavaThread* THREAD = this; 2059 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); 2060 } 2061 case _thread_in_native: 2062 { 2063 ThreadInVMfromNative tiv(this); 2064 JavaThread* THREAD = this; 2065 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); 2066 } 2067 case _thread_in_Java: 2068 { 2069 ThreadInVMfromJava tiv(this); 2070 JavaThread* THREAD = this; 2071 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code"); 2072 } 2073 default: 2074 ShouldNotReachHere(); 2075 } 2076 } 2077 2078 assert(condition == _no_async_condition || has_pending_exception() || 2079 (!check_unsafe_error && condition == _async_unsafe_access_error), 2080 "must have handled the async condition, if no exception"); 2081 } 2082 2083 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) { 2084 // 2085 // Check for pending external suspend. Internal suspend requests do 2086 // not use handle_special_runtime_exit_condition(). 2087 // If JNIEnv proxies are allowed, don't self-suspend if the target 2088 // thread is not the current thread. In older versions of jdbx, jdbx 2089 // threads could call into the VM with another thread's JNIEnv so we 2090 // can be here operating on behalf of a suspended thread (4432884). 2091 bool do_self_suspend = is_external_suspend_with_lock(); 2092 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) { 2093 // 2094 // Because thread is external suspended the safepoint code will count 2095 // thread as at a safepoint. This can be odd because we can be here 2096 // as _thread_in_Java which would normally transition to _thread_blocked 2097 // at a safepoint. We would like to mark the thread as _thread_blocked 2098 // before calling java_suspend_self like all other callers of it but 2099 // we must then observe proper safepoint protocol. (We can't leave 2100 // _thread_blocked with a safepoint in progress). However we can be 2101 // here as _thread_in_native_trans so we can't use a normal transition 2102 // constructor/destructor pair because they assert on that type of 2103 // transition. We could do something like: 2104 // 2105 // JavaThreadState state = thread_state(); 2106 // set_thread_state(_thread_in_vm); 2107 // { 2108 // ThreadBlockInVM tbivm(this); 2109 // java_suspend_self() 2110 // } 2111 // set_thread_state(_thread_in_vm_trans); 2112 // if (safepoint) block; 2113 // set_thread_state(state); 2114 // 2115 // but that is pretty messy. Instead we just go with the way the 2116 // code has worked before and note that this is the only path to 2117 // java_suspend_self that doesn't put the thread in _thread_blocked 2118 // mode. 2119 2120 frame_anchor()->make_walkable(this); 2121 java_suspend_self(); 2122 2123 // We might be here for reasons in addition to the self-suspend request 2124 // so check for other async requests. 2125 } 2126 2127 if (check_asyncs) { 2128 check_and_handle_async_exceptions(); 2129 } 2130 } 2131 2132 void JavaThread::send_thread_stop(oop java_throwable) { 2133 assert(Thread::current()->is_VM_thread(), "should be in the vm thread"); 2134 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code"); 2135 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); 2136 2137 // Do not throw asynchronous exceptions against the compiler thread 2138 // (the compiler thread should not be a Java thread -- fix in 1.4.2) 2139 if (is_Compiler_thread()) return; 2140 2141 { 2142 // Actually throw the Throwable against the target Thread - however 2143 // only if there is no thread death exception installed already. 2144 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) { 2145 // If the topmost frame is a runtime stub, then we are calling into 2146 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) 2147 // must deoptimize the caller before continuing, as the compiled exception handler table 2148 // may not be valid 2149 if (has_last_Java_frame()) { 2150 frame f = last_frame(); 2151 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) { 2152 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 2153 RegisterMap reg_map(this, UseBiasedLocking); 2154 frame compiled_frame = f.sender(®_map); 2155 if (compiled_frame.can_be_deoptimized()) { 2156 Deoptimization::deoptimize(this, compiled_frame, ®_map); 2157 } 2158 } 2159 } 2160 2161 // Set async. pending exception in thread. 2162 set_pending_async_exception(java_throwable); 2163 2164 if (TraceExceptions) { 2165 ResourceMark rm; 2166 tty->print_cr("Pending Async. exception installed of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name()); 2167 } 2168 // for AbortVMOnException flag 2169 NOT_PRODUCT(Exceptions::debug_check_abort(InstanceKlass::cast(_pending_async_exception->klass())->external_name())); 2170 } 2171 } 2172 2173 2174 // Interrupt thread so it will wake up from a potential wait() 2175 Thread::interrupt(this); 2176 } 2177 2178 // External suspension mechanism. 2179 // 2180 // Tell the VM to suspend a thread when ever it knows that it does not hold on 2181 // to any VM_locks and it is at a transition 2182 // Self-suspension will happen on the transition out of the vm. 2183 // Catch "this" coming in from JNIEnv pointers when the thread has been freed 2184 // 2185 // Guarantees on return: 2186 // + Target thread will not execute any new bytecode (that's why we need to 2187 // force a safepoint) 2188 // + Target thread will not enter any new monitors 2189 // 2190 void JavaThread::java_suspend() { 2191 { MutexLocker mu(Threads_lock); 2192 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) { 2193 return; 2194 } 2195 } 2196 2197 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 2198 if (!is_external_suspend()) { 2199 // a racing resume has cancelled us; bail out now 2200 return; 2201 } 2202 2203 // suspend is done 2204 uint32_t debug_bits = 0; 2205 // Warning: is_ext_suspend_completed() may temporarily drop the 2206 // SR_lock to allow the thread to reach a stable thread state if 2207 // it is currently in a transient thread state. 2208 if (is_ext_suspend_completed(false /* !called_by_wait */, 2209 SuspendRetryDelay, &debug_bits) ) { 2210 return; 2211 } 2212 } 2213 2214 VM_ForceSafepoint vm_suspend; 2215 VMThread::execute(&vm_suspend); 2216 } 2217 2218 // Part II of external suspension. 2219 // A JavaThread self suspends when it detects a pending external suspend 2220 // request. This is usually on transitions. It is also done in places 2221 // where continuing to the next transition would surprise the caller, 2222 // e.g., monitor entry. 2223 // 2224 // Returns the number of times that the thread self-suspended. 2225 // 2226 // Note: DO NOT call java_suspend_self() when you just want to block current 2227 // thread. java_suspend_self() is the second stage of cooperative 2228 // suspension for external suspend requests and should only be used 2229 // to complete an external suspend request. 2230 // 2231 int JavaThread::java_suspend_self() { 2232 int ret = 0; 2233 2234 // we are in the process of exiting so don't suspend 2235 if (is_exiting()) { 2236 clear_external_suspend(); 2237 return ret; 2238 } 2239 2240 assert(_anchor.walkable() || 2241 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()), 2242 "must have walkable stack"); 2243 2244 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 2245 2246 assert(!this->is_ext_suspended(), 2247 "a thread trying to self-suspend should not already be suspended"); 2248 2249 if (this->is_suspend_equivalent()) { 2250 // If we are self-suspending as a result of the lifting of a 2251 // suspend equivalent condition, then the suspend_equivalent 2252 // flag is not cleared until we set the ext_suspended flag so 2253 // that wait_for_ext_suspend_completion() returns consistent 2254 // results. 2255 this->clear_suspend_equivalent(); 2256 } 2257 2258 // A racing resume may have cancelled us before we grabbed SR_lock 2259 // above. Or another external suspend request could be waiting for us 2260 // by the time we return from SR_lock()->wait(). The thread 2261 // that requested the suspension may already be trying to walk our 2262 // stack and if we return now, we can change the stack out from under 2263 // it. This would be a "bad thing (TM)" and cause the stack walker 2264 // to crash. We stay self-suspended until there are no more pending 2265 // external suspend requests. 2266 while (is_external_suspend()) { 2267 ret++; 2268 this->set_ext_suspended(); 2269 2270 // _ext_suspended flag is cleared by java_resume() 2271 while (is_ext_suspended()) { 2272 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag); 2273 } 2274 } 2275 2276 return ret; 2277 } 2278 2279 #ifdef ASSERT 2280 // verify the JavaThread has not yet been published in the Threads::list, and 2281 // hence doesn't need protection from concurrent access at this stage 2282 void JavaThread::verify_not_published() { 2283 if (!Threads_lock->owned_by_self()) { 2284 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag); 2285 assert( !Threads::includes(this), 2286 "java thread shouldn't have been published yet!"); 2287 } 2288 else { 2289 assert( !Threads::includes(this), 2290 "java thread shouldn't have been published yet!"); 2291 } 2292 } 2293 #endif 2294 2295 // Slow path when the native==>VM/Java barriers detect a safepoint is in 2296 // progress or when _suspend_flags is non-zero. 2297 // Current thread needs to self-suspend if there is a suspend request and/or 2298 // block if a safepoint is in progress. 2299 // Async exception ISN'T checked. 2300 // Note only the ThreadInVMfromNative transition can call this function 2301 // directly and when thread state is _thread_in_native_trans 2302 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) { 2303 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); 2304 2305 JavaThread *curJT = JavaThread::current(); 2306 bool do_self_suspend = thread->is_external_suspend(); 2307 2308 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition"); 2309 2310 // If JNIEnv proxies are allowed, don't self-suspend if the target 2311 // thread is not the current thread. In older versions of jdbx, jdbx 2312 // threads could call into the VM with another thread's JNIEnv so we 2313 // can be here operating on behalf of a suspended thread (4432884). 2314 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) { 2315 JavaThreadState state = thread->thread_state(); 2316 2317 // We mark this thread_blocked state as a suspend-equivalent so 2318 // that a caller to is_ext_suspend_completed() won't be confused. 2319 // The suspend-equivalent state is cleared by java_suspend_self(). 2320 thread->set_suspend_equivalent(); 2321 2322 // If the safepoint code sees the _thread_in_native_trans state, it will 2323 // wait until the thread changes to other thread state. There is no 2324 // guarantee on how soon we can obtain the SR_lock and complete the 2325 // self-suspend request. It would be a bad idea to let safepoint wait for 2326 // too long. Temporarily change the state to _thread_blocked to 2327 // let the VM thread know that this thread is ready for GC. The problem 2328 // of changing thread state is that safepoint could happen just after 2329 // java_suspend_self() returns after being resumed, and VM thread will 2330 // see the _thread_blocked state. We must check for safepoint 2331 // after restoring the state and make sure we won't leave while a safepoint 2332 // is in progress. 2333 thread->set_thread_state(_thread_blocked); 2334 thread->java_suspend_self(); 2335 thread->set_thread_state(state); 2336 // Make sure new state is seen by VM thread 2337 if (os::is_MP()) { 2338 if (UseMembar) { 2339 // Force a fence between the write above and read below 2340 OrderAccess::fence(); 2341 } else { 2342 // Must use this rather than serialization page in particular on Windows 2343 InterfaceSupport::serialize_memory(thread); 2344 } 2345 } 2346 } 2347 2348 if (SafepointSynchronize::do_call_back()) { 2349 // If we are safepointing, then block the caller which may not be 2350 // the same as the target thread (see above). 2351 SafepointSynchronize::block(curJT); 2352 } 2353 2354 if (thread->is_deopt_suspend()) { 2355 thread->clear_deopt_suspend(); 2356 RegisterMap map(thread, false); 2357 frame f = thread->last_frame(); 2358 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) { 2359 f = f.sender(&map); 2360 } 2361 if (f.id() == thread->must_deopt_id()) { 2362 thread->clear_must_deopt_id(); 2363 f.deoptimize(thread); 2364 } else { 2365 fatal("missed deoptimization!"); 2366 } 2367 } 2368 } 2369 2370 // Slow path when the native==>VM/Java barriers detect a safepoint is in 2371 // progress or when _suspend_flags is non-zero. 2372 // Current thread needs to self-suspend if there is a suspend request and/or 2373 // block if a safepoint is in progress. 2374 // Also check for pending async exception (not including unsafe access error). 2375 // Note only the native==>VM/Java barriers can call this function and when 2376 // thread state is _thread_in_native_trans. 2377 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { 2378 check_safepoint_and_suspend_for_native_trans(thread); 2379 2380 if (thread->has_async_exception()) { 2381 // We are in _thread_in_native_trans state, don't handle unsafe 2382 // access error since that may block. 2383 thread->check_and_handle_async_exceptions(false); 2384 } 2385 } 2386 2387 // This is a variant of the normal 2388 // check_special_condition_for_native_trans with slightly different 2389 // semantics for use by critical native wrappers. It does all the 2390 // normal checks but also performs the transition back into 2391 // thread_in_Java state. This is required so that critical natives 2392 // can potentially block and perform a GC if they are the last thread 2393 // exiting the GC_locker. 2394 void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) { 2395 check_special_condition_for_native_trans(thread); 2396 2397 // Finish the transition 2398 thread->set_thread_state(_thread_in_Java); 2399 2400 if (thread->do_critical_native_unlock()) { 2401 ThreadInVMfromJavaNoAsyncException tiv(thread); 2402 GC_locker::unlock_critical(thread); 2403 thread->clear_critical_native_unlock(); 2404 } 2405 } 2406 2407 // We need to guarantee the Threads_lock here, since resumes are not 2408 // allowed during safepoint synchronization 2409 // Can only resume from an external suspension 2410 void JavaThread::java_resume() { 2411 assert_locked_or_safepoint(Threads_lock); 2412 2413 // Sanity check: thread is gone, has started exiting or the thread 2414 // was not externally suspended. 2415 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) { 2416 return; 2417 } 2418 2419 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 2420 2421 clear_external_suspend(); 2422 2423 if (is_ext_suspended()) { 2424 clear_ext_suspended(); 2425 SR_lock()->notify_all(); 2426 } 2427 } 2428 2429 void JavaThread::create_stack_guard_pages() { 2430 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return; 2431 address low_addr = stack_base() - stack_size(); 2432 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); 2433 2434 int allocate = os::allocate_stack_guard_pages(); 2435 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len); 2436 2437 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) { 2438 warning("Attempt to allocate stack guard pages failed."); 2439 return; 2440 } 2441 2442 if (os::guard_memory((char *) low_addr, len)) { 2443 _stack_guard_state = stack_guard_enabled; 2444 } else { 2445 warning("Attempt to protect stack guard pages failed."); 2446 if (os::uncommit_memory((char *) low_addr, len)) { 2447 warning("Attempt to deallocate stack guard pages failed."); 2448 } 2449 } 2450 } 2451 2452 void JavaThread::remove_stack_guard_pages() { 2453 assert(Thread::current() == this, "from different thread"); 2454 if (_stack_guard_state == stack_guard_unused) return; 2455 address low_addr = stack_base() - stack_size(); 2456 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); 2457 2458 if (os::allocate_stack_guard_pages()) { 2459 if (os::remove_stack_guard_pages((char *) low_addr, len)) { 2460 _stack_guard_state = stack_guard_unused; 2461 } else { 2462 warning("Attempt to deallocate stack guard pages failed."); 2463 } 2464 } else { 2465 if (_stack_guard_state == stack_guard_unused) return; 2466 if (os::unguard_memory((char *) low_addr, len)) { 2467 _stack_guard_state = stack_guard_unused; 2468 } else { 2469 warning("Attempt to unprotect stack guard pages failed."); 2470 } 2471 } 2472 } 2473 2474 void JavaThread::enable_stack_yellow_zone() { 2475 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2476 assert(_stack_guard_state != stack_guard_enabled, "already enabled"); 2477 2478 // The base notation is from the stacks point of view, growing downward. 2479 // We need to adjust it to work correctly with guard_memory() 2480 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); 2481 2482 guarantee(base < stack_base(),"Error calculating stack yellow zone"); 2483 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone"); 2484 2485 if (os::guard_memory((char *) base, stack_yellow_zone_size())) { 2486 _stack_guard_state = stack_guard_enabled; 2487 } else { 2488 warning("Attempt to guard stack yellow zone failed."); 2489 } 2490 enable_register_stack_guard(); 2491 } 2492 2493 void JavaThread::disable_stack_yellow_zone() { 2494 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2495 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled"); 2496 2497 // Simply return if called for a thread that does not use guard pages. 2498 if (_stack_guard_state == stack_guard_unused) return; 2499 2500 // The base notation is from the stacks point of view, growing downward. 2501 // We need to adjust it to work correctly with guard_memory() 2502 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); 2503 2504 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) { 2505 _stack_guard_state = stack_guard_yellow_disabled; 2506 } else { 2507 warning("Attempt to unguard stack yellow zone failed."); 2508 } 2509 disable_register_stack_guard(); 2510 } 2511 2512 void JavaThread::enable_stack_red_zone() { 2513 // The base notation is from the stacks point of view, growing downward. 2514 // We need to adjust it to work correctly with guard_memory() 2515 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2516 address base = stack_red_zone_base() - stack_red_zone_size(); 2517 2518 guarantee(base < stack_base(),"Error calculating stack red zone"); 2519 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone"); 2520 2521 if(!os::guard_memory((char *) base, stack_red_zone_size())) { 2522 warning("Attempt to guard stack red zone failed."); 2523 } 2524 } 2525 2526 void JavaThread::disable_stack_red_zone() { 2527 // The base notation is from the stacks point of view, growing downward. 2528 // We need to adjust it to work correctly with guard_memory() 2529 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); 2530 address base = stack_red_zone_base() - stack_red_zone_size(); 2531 if (!os::unguard_memory((char *)base, stack_red_zone_size())) { 2532 warning("Attempt to unguard stack red zone failed."); 2533 } 2534 } 2535 2536 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { 2537 // ignore is there is no stack 2538 if (!has_last_Java_frame()) return; 2539 // traverse the stack frames. Starts from top frame. 2540 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2541 frame* fr = fst.current(); 2542 f(fr, fst.register_map()); 2543 } 2544 } 2545 2546 2547 #ifndef PRODUCT 2548 // Deoptimization 2549 // Function for testing deoptimization 2550 void JavaThread::deoptimize() { 2551 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 2552 StackFrameStream fst(this, UseBiasedLocking); 2553 bool deopt = false; // Dump stack only if a deopt actually happens. 2554 bool only_at = strlen(DeoptimizeOnlyAt) > 0; 2555 // Iterate over all frames in the thread and deoptimize 2556 for(; !fst.is_done(); fst.next()) { 2557 if(fst.current()->can_be_deoptimized()) { 2558 2559 if (only_at) { 2560 // Deoptimize only at particular bcis. DeoptimizeOnlyAt 2561 // consists of comma or carriage return separated numbers so 2562 // search for the current bci in that string. 2563 address pc = fst.current()->pc(); 2564 nmethod* nm = (nmethod*) fst.current()->cb(); 2565 ScopeDesc* sd = nm->scope_desc_at( pc); 2566 char buffer[8]; 2567 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); 2568 size_t len = strlen(buffer); 2569 const char * found = strstr(DeoptimizeOnlyAt, buffer); 2570 while (found != NULL) { 2571 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && 2572 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { 2573 // Check that the bci found is bracketed by terminators. 2574 break; 2575 } 2576 found = strstr(found + 1, buffer); 2577 } 2578 if (!found) { 2579 continue; 2580 } 2581 } 2582 2583 if (DebugDeoptimization && !deopt) { 2584 deopt = true; // One-time only print before deopt 2585 tty->print_cr("[BEFORE Deoptimization]"); 2586 trace_frames(); 2587 trace_stack(); 2588 } 2589 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); 2590 } 2591 } 2592 2593 if (DebugDeoptimization && deopt) { 2594 tty->print_cr("[AFTER Deoptimization]"); 2595 trace_frames(); 2596 } 2597 } 2598 2599 2600 // Make zombies 2601 void JavaThread::make_zombies() { 2602 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2603 if (fst.current()->can_be_deoptimized()) { 2604 // it is a Java nmethod 2605 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); 2606 nm->make_not_entrant(); 2607 } 2608 } 2609 } 2610 #endif // PRODUCT 2611 2612 2613 void JavaThread::deoptimized_wrt_marked_nmethods() { 2614 if (!has_last_Java_frame()) return; 2615 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass 2616 StackFrameStream fst(this, UseBiasedLocking); 2617 for(; !fst.is_done(); fst.next()) { 2618 if (fst.current()->should_be_deoptimized()) { 2619 if (LogCompilation && xtty != NULL) { 2620 nmethod* nm = fst.current()->cb()->as_nmethod_or_null(); 2621 xtty->elem("deoptimized thread='" UINTX_FORMAT "' compile_id='%d'", 2622 this->name(), nm != NULL ? nm->compile_id() : -1); 2623 } 2624 2625 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); 2626 } 2627 } 2628 } 2629 2630 2631 // GC support 2632 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); } 2633 2634 void JavaThread::gc_epilogue() { 2635 frames_do(frame_gc_epilogue); 2636 } 2637 2638 2639 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); } 2640 2641 void JavaThread::gc_prologue() { 2642 frames_do(frame_gc_prologue); 2643 } 2644 2645 // If the caller is a NamedThread, then remember, in the current scope, 2646 // the given JavaThread in its _processed_thread field. 2647 class RememberProcessedThread: public StackObj { 2648 NamedThread* _cur_thr; 2649 public: 2650 RememberProcessedThread(JavaThread* jthr) { 2651 Thread* thread = Thread::current(); 2652 if (thread->is_Named_thread()) { 2653 _cur_thr = (NamedThread *)thread; 2654 _cur_thr->set_processed_thread(jthr); 2655 } else { 2656 _cur_thr = NULL; 2657 } 2658 } 2659 2660 ~RememberProcessedThread() { 2661 if (_cur_thr) { 2662 _cur_thr->set_processed_thread(NULL); 2663 } 2664 } 2665 }; 2666 2667 void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) { 2668 // Verify that the deferred card marks have been flushed. 2669 assert(deferred_card_mark().is_empty(), "Should be empty during GC"); 2670 2671 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do 2672 // since there may be more than one thread using each ThreadProfiler. 2673 2674 // Traverse the GCHandles 2675 Thread::oops_do(f, cf); 2676 2677 assert( (!has_last_Java_frame() && java_call_counter() == 0) || 2678 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); 2679 2680 if (has_last_Java_frame()) { 2681 // Record JavaThread to GC thread 2682 RememberProcessedThread rpt(this); 2683 2684 // Traverse the privileged stack 2685 if (_privileged_stack_top != NULL) { 2686 _privileged_stack_top->oops_do(f); 2687 } 2688 2689 // traverse the registered growable array 2690 if (_array_for_gc != NULL) { 2691 for (int index = 0; index < _array_for_gc->length(); index++) { 2692 f->do_oop(_array_for_gc->adr_at(index)); 2693 } 2694 } 2695 2696 // Traverse the monitor chunks 2697 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { 2698 chunk->oops_do(f); 2699 } 2700 2701 // Traverse the execution stack 2702 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2703 fst.current()->oops_do(f, cf, fst.register_map()); 2704 } 2705 } 2706 2707 // callee_target is never live across a gc point so NULL it here should 2708 // it still contain a methdOop. 2709 2710 set_callee_target(NULL); 2711 2712 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!"); 2713 // If we have deferred set_locals there might be oops waiting to be 2714 // written 2715 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals(); 2716 if (list != NULL) { 2717 for (int i = 0; i < list->length(); i++) { 2718 list->at(i)->oops_do(f); 2719 } 2720 } 2721 2722 // Traverse instance variables at the end since the GC may be moving things 2723 // around using this function 2724 f->do_oop((oop*) &_threadObj); 2725 f->do_oop((oop*) &_vm_result); 2726 f->do_oop((oop*) &_exception_oop); 2727 f->do_oop((oop*) &_pending_async_exception); 2728 2729 if (jvmti_thread_state() != NULL) { 2730 jvmti_thread_state()->oops_do(f); 2731 } 2732 } 2733 2734 void JavaThread::nmethods_do(CodeBlobClosure* cf) { 2735 Thread::nmethods_do(cf); // (super method is a no-op) 2736 2737 assert( (!has_last_Java_frame() && java_call_counter() == 0) || 2738 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); 2739 2740 if (has_last_Java_frame()) { 2741 // Traverse the execution stack 2742 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2743 fst.current()->nmethods_do(cf); 2744 } 2745 } 2746 } 2747 2748 void JavaThread::metadata_do(void f(Metadata*)) { 2749 Thread::metadata_do(f); 2750 if (has_last_Java_frame()) { 2751 // Traverse the execution stack to call f() on the methods in the stack 2752 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 2753 fst.current()->metadata_do(f); 2754 } 2755 } else if (is_Compiler_thread()) { 2756 // need to walk ciMetadata in current compile tasks to keep alive. 2757 CompilerThread* ct = (CompilerThread*)this; 2758 if (ct->env() != NULL) { 2759 ct->env()->metadata_do(f); 2760 } 2761 } 2762 } 2763 2764 // Printing 2765 const char* _get_thread_state_name(JavaThreadState _thread_state) { 2766 switch (_thread_state) { 2767 case _thread_uninitialized: return "_thread_uninitialized"; 2768 case _thread_new: return "_thread_new"; 2769 case _thread_new_trans: return "_thread_new_trans"; 2770 case _thread_in_native: return "_thread_in_native"; 2771 case _thread_in_native_trans: return "_thread_in_native_trans"; 2772 case _thread_in_vm: return "_thread_in_vm"; 2773 case _thread_in_vm_trans: return "_thread_in_vm_trans"; 2774 case _thread_in_Java: return "_thread_in_Java"; 2775 case _thread_in_Java_trans: return "_thread_in_Java_trans"; 2776 case _thread_blocked: return "_thread_blocked"; 2777 case _thread_blocked_trans: return "_thread_blocked_trans"; 2778 default: return "unknown thread state"; 2779 } 2780 } 2781 2782 #ifndef PRODUCT 2783 void JavaThread::print_thread_state_on(outputStream *st) const { 2784 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); 2785 }; 2786 void JavaThread::print_thread_state() const { 2787 print_thread_state_on(tty); 2788 }; 2789 #endif // PRODUCT 2790 2791 // Called by Threads::print() for VM_PrintThreads operation 2792 void JavaThread::print_on(outputStream *st) const { 2793 st->print("\"%s\" ", get_thread_name()); 2794 oop thread_oop = threadObj(); 2795 if (thread_oop != NULL) { 2796 st->print("#" INT64_FORMAT " ", java_lang_Thread::thread_id(thread_oop)); 2797 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); 2798 st->print("prio=%d ", java_lang_Thread::priority(thread_oop)); 2799 } 2800 Thread::print_on(st); 2801 // print guess for valid stack memory region (assume 4K pages); helps lock debugging 2802 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12)); 2803 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) { 2804 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); 2805 } 2806 #ifndef PRODUCT 2807 print_thread_state_on(st); 2808 _safepoint_state->print_on(st); 2809 #endif // PRODUCT 2810 } 2811 2812 // Called by fatal error handler. The difference between this and 2813 // JavaThread::print() is that we can't grab lock or allocate memory. 2814 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { 2815 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen)); 2816 oop thread_obj = threadObj(); 2817 if (thread_obj != NULL) { 2818 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon"); 2819 } 2820 st->print(" ["); 2821 st->print("%s", _get_thread_state_name(_thread_state)); 2822 if (osthread()) { 2823 st->print(", id=%d", osthread()->thread_id()); 2824 } 2825 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")", 2826 _stack_base - _stack_size, _stack_base); 2827 st->print("]"); 2828 return; 2829 } 2830 2831 // Verification 2832 2833 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } 2834 2835 void JavaThread::verify() { 2836 // Verify oops in the thread. 2837 oops_do(&VerifyOopClosure::verify_oop, NULL); 2838 2839 // Verify the stack frames. 2840 frames_do(frame_verify); 2841 } 2842 2843 // CR 6300358 (sub-CR 2137150) 2844 // Most callers of this method assume that it can't return NULL but a 2845 // thread may not have a name whilst it is in the process of attaching to 2846 // the VM - see CR 6412693, and there are places where a JavaThread can be 2847 // seen prior to having it's threadObj set (eg JNI attaching threads and 2848 // if vm exit occurs during initialization). These cases can all be accounted 2849 // for such that this method never returns NULL. 2850 const char* JavaThread::get_thread_name() const { 2851 #ifdef ASSERT 2852 // early safepoints can hit while current thread does not yet have TLS 2853 if (!SafepointSynchronize::is_at_safepoint()) { 2854 Thread *cur = Thread::current(); 2855 if (!(cur->is_Java_thread() && cur == this)) { 2856 // Current JavaThreads are allowed to get their own name without 2857 // the Threads_lock. 2858 assert_locked_or_safepoint(Threads_lock); 2859 } 2860 } 2861 #endif // ASSERT 2862 return get_thread_name_string(); 2863 } 2864 2865 // Returns a non-NULL representation of this thread's name, or a suitable 2866 // descriptive string if there is no set name 2867 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { 2868 const char* name_str; 2869 oop thread_obj = threadObj(); 2870 if (thread_obj != NULL) { 2871 typeArrayOop name = java_lang_Thread::name(thread_obj); 2872 if (name != NULL) { 2873 if (buf == NULL) { 2874 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2875 } 2876 else { 2877 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen); 2878 } 2879 } 2880 else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306 2881 name_str = "<no-name - thread is attaching>"; 2882 } 2883 else { 2884 name_str = Thread::name(); 2885 } 2886 } 2887 else { 2888 name_str = Thread::name(); 2889 } 2890 assert(name_str != NULL, "unexpected NULL thread name"); 2891 return name_str; 2892 } 2893 2894 2895 const char* JavaThread::get_threadgroup_name() const { 2896 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) 2897 oop thread_obj = threadObj(); 2898 if (thread_obj != NULL) { 2899 oop thread_group = java_lang_Thread::threadGroup(thread_obj); 2900 if (thread_group != NULL) { 2901 typeArrayOop name = java_lang_ThreadGroup::name(thread_group); 2902 // ThreadGroup.name can be null 2903 if (name != NULL) { 2904 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2905 return str; 2906 } 2907 } 2908 } 2909 return NULL; 2910 } 2911 2912 const char* JavaThread::get_parent_name() const { 2913 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) 2914 oop thread_obj = threadObj(); 2915 if (thread_obj != NULL) { 2916 oop thread_group = java_lang_Thread::threadGroup(thread_obj); 2917 if (thread_group != NULL) { 2918 oop parent = java_lang_ThreadGroup::parent(thread_group); 2919 if (parent != NULL) { 2920 typeArrayOop name = java_lang_ThreadGroup::name(parent); 2921 // ThreadGroup.name can be null 2922 if (name != NULL) { 2923 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); 2924 return str; 2925 } 2926 } 2927 } 2928 } 2929 return NULL; 2930 } 2931 2932 ThreadPriority JavaThread::java_priority() const { 2933 oop thr_oop = threadObj(); 2934 if (thr_oop == NULL) return NormPriority; // Bootstrapping 2935 ThreadPriority priority = java_lang_Thread::priority(thr_oop); 2936 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 2937 return priority; 2938 } 2939 2940 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { 2941 2942 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); 2943 // Link Java Thread object <-> C++ Thread 2944 2945 // Get the C++ thread object (an oop) from the JNI handle (a jthread) 2946 // and put it into a new Handle. The Handle "thread_oop" can then 2947 // be used to pass the C++ thread object to other methods. 2948 2949 // Set the Java level thread object (jthread) field of the 2950 // new thread (a JavaThread *) to C++ thread object using the 2951 // "thread_oop" handle. 2952 2953 // Set the thread field (a JavaThread *) of the 2954 // oop representing the java_lang_Thread to the new thread (a JavaThread *). 2955 2956 Handle thread_oop(Thread::current(), 2957 JNIHandles::resolve_non_null(jni_thread)); 2958 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(), 2959 "must be initialized"); 2960 set_threadObj(thread_oop()); 2961 java_lang_Thread::set_thread(thread_oop(), this); 2962 2963 if (prio == NoPriority) { 2964 prio = java_lang_Thread::priority(thread_oop()); 2965 assert(prio != NoPriority, "A valid priority should be present"); 2966 } 2967 2968 // Push the Java priority down to the native thread; needs Threads_lock 2969 Thread::set_priority(this, prio); 2970 2971 // Add the new thread to the Threads list and set it in motion. 2972 // We must have threads lock in order to call Threads::add. 2973 // It is crucial that we do not block before the thread is 2974 // added to the Threads list for if a GC happens, then the java_thread oop 2975 // will not be visited by GC. 2976 Threads::add(this); 2977 } 2978 2979 oop JavaThread::current_park_blocker() { 2980 // Support for JSR-166 locks 2981 oop thread_oop = threadObj(); 2982 if (thread_oop != NULL && 2983 JDK_Version::current().supports_thread_park_blocker()) { 2984 return java_lang_Thread::park_blocker(thread_oop); 2985 } 2986 return NULL; 2987 } 2988 2989 2990 void JavaThread::print_stack_on(outputStream* st) { 2991 if (!has_last_Java_frame()) return; 2992 ResourceMark rm; 2993 HandleMark hm; 2994 2995 RegisterMap reg_map(this); 2996 vframe* start_vf = last_java_vframe(®_map); 2997 int count = 0; 2998 for (vframe* f = start_vf; f; f = f->sender() ) { 2999 if (f->is_java_frame()) { 3000 javaVFrame* jvf = javaVFrame::cast(f); 3001 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 3002 3003 // Print out lock information 3004 if (JavaMonitorsInStackTrace) { 3005 jvf->print_lock_info_on(st, count); 3006 } 3007 } else { 3008 // Ignore non-Java frames 3009 } 3010 3011 // Bail-out case for too deep stacks 3012 count++; 3013 if (MaxJavaStackTraceDepth == count) return; 3014 } 3015 } 3016 3017 3018 // JVMTI PopFrame support 3019 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { 3020 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments"); 3021 if (in_bytes(size_in_bytes) != 0) { 3022 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread); 3023 _popframe_preserved_args_size = in_bytes(size_in_bytes); 3024 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size); 3025 } 3026 } 3027 3028 void* JavaThread::popframe_preserved_args() { 3029 return _popframe_preserved_args; 3030 } 3031 3032 ByteSize JavaThread::popframe_preserved_args_size() { 3033 return in_ByteSize(_popframe_preserved_args_size); 3034 } 3035 3036 WordSize JavaThread::popframe_preserved_args_size_in_words() { 3037 int sz = in_bytes(popframe_preserved_args_size()); 3038 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); 3039 return in_WordSize(sz / wordSize); 3040 } 3041 3042 void JavaThread::popframe_free_preserved_args() { 3043 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice"); 3044 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args, mtThread); 3045 _popframe_preserved_args = NULL; 3046 _popframe_preserved_args_size = 0; 3047 } 3048 3049 #ifndef PRODUCT 3050 3051 void JavaThread::trace_frames() { 3052 tty->print_cr("[Describe stack]"); 3053 int frame_no = 1; 3054 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { 3055 tty->print(" %d. ", frame_no++); 3056 fst.current()->print_value_on(tty,this); 3057 tty->cr(); 3058 } 3059 } 3060 3061 class PrintAndVerifyOopClosure: public OopClosure { 3062 protected: 3063 template <class T> inline void do_oop_work(T* p) { 3064 oop obj = oopDesc::load_decode_heap_oop(p); 3065 if (obj == NULL) return; 3066 tty->print(INTPTR_FORMAT ": ", p); 3067 if (obj->is_oop_or_null()) { 3068 if (obj->is_objArray()) { 3069 tty->print_cr("valid objArray: " INTPTR_FORMAT, (oopDesc*) obj); 3070 } else { 3071 obj->print(); 3072 } 3073 } else { 3074 tty->print_cr("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj); 3075 } 3076 tty->cr(); 3077 } 3078 public: 3079 virtual void do_oop(oop* p) { do_oop_work(p); } 3080 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 3081 }; 3082 3083 3084 static void oops_print(frame* f, const RegisterMap *map) { 3085 PrintAndVerifyOopClosure print; 3086 f->print_value(); 3087 f->oops_do(&print, NULL, (RegisterMap*)map); 3088 } 3089 3090 // Print our all the locations that contain oops and whether they are 3091 // valid or not. This useful when trying to find the oldest frame 3092 // where an oop has gone bad since the frame walk is from youngest to 3093 // oldest. 3094 void JavaThread::trace_oops() { 3095 tty->print_cr("[Trace oops]"); 3096 frames_do(oops_print); 3097 } 3098 3099 3100 #ifdef ASSERT 3101 // Print or validate the layout of stack frames 3102 void JavaThread::print_frame_layout(int depth, bool validate_only) { 3103 ResourceMark rm; 3104 PRESERVE_EXCEPTION_MARK; 3105 FrameValues values; 3106 int frame_no = 0; 3107 for(StackFrameStream fst(this, false); !fst.is_done(); fst.next()) { 3108 fst.current()->describe(values, ++frame_no); 3109 if (depth == frame_no) break; 3110 } 3111 if (validate_only) { 3112 values.validate(); 3113 } else { 3114 tty->print_cr("[Describe stack layout]"); 3115 values.print(this); 3116 } 3117 } 3118 #endif 3119 3120 void JavaThread::trace_stack_from(vframe* start_vf) { 3121 ResourceMark rm; 3122 int vframe_no = 1; 3123 for (vframe* f = start_vf; f; f = f->sender() ) { 3124 if (f->is_java_frame()) { 3125 javaVFrame::cast(f)->print_activation(vframe_no++); 3126 } else { 3127 f->print(); 3128 } 3129 if (vframe_no > StackPrintLimit) { 3130 tty->print_cr("...<more frames>..."); 3131 return; 3132 } 3133 } 3134 } 3135 3136 3137 void JavaThread::trace_stack() { 3138 if (!has_last_Java_frame()) return; 3139 ResourceMark rm; 3140 HandleMark hm; 3141 RegisterMap reg_map(this); 3142 trace_stack_from(last_java_vframe(®_map)); 3143 } 3144 3145 3146 #endif // PRODUCT 3147 3148 3149 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) { 3150 assert(reg_map != NULL, "a map must be given"); 3151 frame f = last_frame(); 3152 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) { 3153 if (vf->is_java_frame()) return javaVFrame::cast(vf); 3154 } 3155 return NULL; 3156 } 3157 3158 3159 Klass* JavaThread::security_get_caller_class(int depth) { 3160 vframeStream vfst(this); 3161 vfst.security_get_caller_frame(depth); 3162 if (!vfst.at_end()) { 3163 return vfst.method()->method_holder(); 3164 } 3165 return NULL; 3166 } 3167 3168 static void compiler_thread_entry(JavaThread* thread, TRAPS) { 3169 assert(thread->is_Compiler_thread(), "must be compiler thread"); 3170 CompileBroker::compiler_thread_loop(); 3171 } 3172 3173 // Create a CompilerThread 3174 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters) 3175 : JavaThread(&compiler_thread_entry) { 3176 _env = NULL; 3177 _log = NULL; 3178 _task = NULL; 3179 _queue = queue; 3180 _counters = counters; 3181 _buffer_blob = NULL; 3182 _scanned_nmethod = NULL; 3183 3184 #ifndef PRODUCT 3185 _ideal_graph_printer = NULL; 3186 #endif 3187 } 3188 3189 void CompilerThread::oops_do(OopClosure* f, CodeBlobClosure* cf) { 3190 JavaThread::oops_do(f, cf); 3191 if (_scanned_nmethod != NULL && cf != NULL) { 3192 // Safepoints can occur when the sweeper is scanning an nmethod so 3193 // process it here to make sure it isn't unloaded in the middle of 3194 // a scan. 3195 cf->do_code_blob(_scanned_nmethod); 3196 } 3197 } 3198 3199 // ======= Threads ======== 3200 3201 // The Threads class links together all active threads, and provides 3202 // operations over all threads. It is protected by its own Mutex 3203 // lock, which is also used in other contexts to protect thread 3204 // operations from having the thread being operated on from exiting 3205 // and going away unexpectedly (e.g., safepoint synchronization) 3206 3207 JavaThread* Threads::_thread_list = NULL; 3208 int Threads::_number_of_threads = 0; 3209 int Threads::_number_of_non_daemon_threads = 0; 3210 int Threads::_return_code = 0; 3211 size_t JavaThread::_stack_size_at_create = 0; 3212 #ifdef ASSERT 3213 bool Threads::_vm_complete = false; 3214 #endif 3215 3216 // All JavaThreads 3217 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next()) 3218 3219 void os_stream(); 3220 3221 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system) 3222 void Threads::threads_do(ThreadClosure* tc) { 3223 assert_locked_or_safepoint(Threads_lock); 3224 // ALL_JAVA_THREADS iterates through all JavaThreads 3225 ALL_JAVA_THREADS(p) { 3226 tc->do_thread(p); 3227 } 3228 // Someday we could have a table or list of all non-JavaThreads. 3229 // For now, just manually iterate through them. 3230 tc->do_thread(VMThread::vm_thread()); 3231 Universe::heap()->gc_threads_do(tc); 3232 WatcherThread *wt = WatcherThread::watcher_thread(); 3233 // Strictly speaking, the following NULL check isn't sufficient to make sure 3234 // the data for WatcherThread is still valid upon being examined. However, 3235 // considering that WatchThread terminates when the VM is on the way to 3236 // exit at safepoint, the chance of the above is extremely small. The right 3237 // way to prevent termination of WatcherThread would be to acquire 3238 // Terminator_lock, but we can't do that without violating the lock rank 3239 // checking in some cases. 3240 if (wt != NULL) 3241 tc->do_thread(wt); 3242 3243 // If CompilerThreads ever become non-JavaThreads, add them here 3244 } 3245 3246 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) { 3247 3248 extern void JDK_Version_init(); 3249 3250 // Check version 3251 if (!is_supported_jni_version(args->version)) return JNI_EVERSION; 3252 3253 // Initialize the output stream module 3254 ostream_init(); 3255 3256 // Process java launcher properties. 3257 Arguments::process_sun_java_launcher_properties(args); 3258 3259 // Initialize the os module before using TLS 3260 os::init(); 3261 3262 // Initialize system properties. 3263 Arguments::init_system_properties(); 3264 3265 // So that JDK version can be used as a discrimintor when parsing arguments 3266 JDK_Version_init(); 3267 3268 // Update/Initialize System properties after JDK version number is known 3269 Arguments::init_version_specific_system_properties(); 3270 3271 // Parse arguments 3272 jint parse_result = Arguments::parse(args); 3273 if (parse_result != JNI_OK) return parse_result; 3274 3275 if (PauseAtStartup) { 3276 os::pause(); 3277 } 3278 3279 #ifndef USDT2 3280 HS_DTRACE_PROBE(hotspot, vm__init__begin); 3281 #else /* USDT2 */ 3282 HOTSPOT_VM_INIT_BEGIN(); 3283 #endif /* USDT2 */ 3284 3285 // Record VM creation timing statistics 3286 TraceVmCreationTime create_vm_timer; 3287 create_vm_timer.start(); 3288 3289 // Timing (must come after argument parsing) 3290 TraceTime timer("Create VM", TraceStartupTime); 3291 3292 // Initialize the os module after parsing the args 3293 jint os_init_2_result = os::init_2(); 3294 if (os_init_2_result != JNI_OK) return os_init_2_result; 3295 3296 // intialize TLS 3297 ThreadLocalStorage::init(); 3298 3299 // Bootstrap native memory tracking, so it can start recording memory 3300 // activities before worker thread is started. This is the first phase 3301 // of bootstrapping, VM is currently running in single-thread mode. 3302 MemTracker::bootstrap_single_thread(); 3303 3304 // Initialize output stream logging 3305 ostream_init_log(); 3306 3307 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad 3308 // Must be before create_vm_init_agents() 3309 if (Arguments::init_libraries_at_startup()) { 3310 convert_vm_init_libraries_to_agents(); 3311 } 3312 3313 // Launch -agentlib/-agentpath and converted -Xrun agents 3314 if (Arguments::init_agents_at_startup()) { 3315 create_vm_init_agents(); 3316 } 3317 3318 // Initialize Threads state 3319 _thread_list = NULL; 3320 _number_of_threads = 0; 3321 _number_of_non_daemon_threads = 0; 3322 3323 // Initialize global data structures and create system classes in heap 3324 vm_init_globals(); 3325 3326 // Attach the main thread to this os thread 3327 JavaThread* main_thread = new JavaThread(); 3328 main_thread->set_thread_state(_thread_in_vm); 3329 // must do this before set_active_handles and initialize_thread_local_storage 3330 // Note: on solaris initialize_thread_local_storage() will (indirectly) 3331 // change the stack size recorded here to one based on the java thread 3332 // stacksize. This adjusted size is what is used to figure the placement 3333 // of the guard pages. 3334 main_thread->record_stack_base_and_size(); 3335 main_thread->initialize_thread_local_storage(); 3336 3337 main_thread->set_active_handles(JNIHandleBlock::allocate_block()); 3338 3339 if (!main_thread->set_as_starting_thread()) { 3340 vm_shutdown_during_initialization( 3341 "Failed necessary internal allocation. Out of swap space"); 3342 delete main_thread; 3343 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 3344 return JNI_ENOMEM; 3345 } 3346 3347 // Enable guard page *after* os::create_main_thread(), otherwise it would 3348 // crash Linux VM, see notes in os_linux.cpp. 3349 main_thread->create_stack_guard_pages(); 3350 3351 // Initialize Java-Level synchronization subsystem 3352 ObjectMonitor::Initialize() ; 3353 3354 // Second phase of bootstrapping, VM is about entering multi-thread mode 3355 MemTracker::bootstrap_multi_thread(); 3356 3357 // Initialize global modules 3358 jint status = init_globals(); 3359 if (status != JNI_OK) { 3360 delete main_thread; 3361 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 3362 return status; 3363 } 3364 3365 // Should be done after the heap is fully created 3366 main_thread->cache_global_variables(); 3367 3368 HandleMark hm; 3369 3370 { MutexLocker mu(Threads_lock); 3371 Threads::add(main_thread); 3372 } 3373 3374 // Any JVMTI raw monitors entered in onload will transition into 3375 // real raw monitor. VM is setup enough here for raw monitor enter. 3376 JvmtiExport::transition_pending_onload_raw_monitors(); 3377 3378 if (VerifyBeforeGC && 3379 Universe::heap()->total_collections() >= VerifyGCStartAt) { 3380 Universe::heap()->prepare_for_verify(); 3381 Universe::verify(); // make sure we're starting with a clean slate 3382 } 3383 3384 // Fully start NMT 3385 MemTracker::start(); 3386 3387 // Create the VMThread 3388 { TraceTime timer("Start VMThread", TraceStartupTime); 3389 VMThread::create(); 3390 Thread* vmthread = VMThread::vm_thread(); 3391 3392 if (!os::create_thread(vmthread, os::vm_thread)) 3393 vm_exit_during_initialization("Cannot create VM thread. Out of system resources."); 3394 3395 // Wait for the VM thread to become ready, and VMThread::run to initialize 3396 // Monitors can have spurious returns, must always check another state flag 3397 { 3398 MutexLocker ml(Notify_lock); 3399 os::start_thread(vmthread); 3400 while (vmthread->active_handles() == NULL) { 3401 Notify_lock->wait(); 3402 } 3403 } 3404 } 3405 3406 assert (Universe::is_fully_initialized(), "not initialized"); 3407 EXCEPTION_MARK; 3408 3409 // At this point, the Universe is initialized, but we have not executed 3410 // any byte code. Now is a good time (the only time) to dump out the 3411 // internal state of the JVM for sharing. 3412 if (DumpSharedSpaces) { 3413 MetaspaceShared::preload_and_dump(CHECK_0); 3414 ShouldNotReachHere(); 3415 } 3416 3417 // Always call even when there are not JVMTI environments yet, since environments 3418 // may be attached late and JVMTI must track phases of VM execution 3419 JvmtiExport::enter_start_phase(); 3420 3421 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. 3422 JvmtiExport::post_vm_start(); 3423 3424 { 3425 TraceTime timer("Initialize java.lang classes", TraceStartupTime); 3426 3427 if (EagerXrunInit && Arguments::init_libraries_at_startup()) { 3428 create_vm_init_libraries(); 3429 } 3430 3431 if (InitializeJavaLangString) { 3432 initialize_class(vmSymbols::java_lang_String(), CHECK_0); 3433 } else { 3434 warning("java.lang.String not initialized"); 3435 } 3436 3437 if (AggressiveOpts) { 3438 { 3439 // Forcibly initialize java/util/HashMap and mutate the private 3440 // static final "frontCacheEnabled" field before we start creating instances 3441 #ifdef ASSERT 3442 Klass* tmp_k = SystemDictionary::find(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0); 3443 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet"); 3444 #endif 3445 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0); 3446 KlassHandle k = KlassHandle(THREAD, k_o); 3447 guarantee(k.not_null(), "Must find java/util/HashMap"); 3448 instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); 3449 ik->initialize(CHECK_0); 3450 fieldDescriptor fd; 3451 // Possible we might not find this field; if so, don't break 3452 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { 3453 k()->java_mirror()->bool_field_put(fd.offset(), true); 3454 } 3455 } 3456 3457 if (UseStringCache) { 3458 // Forcibly initialize java/lang/StringValue and mutate the private 3459 // static final "stringCacheEnabled" field before we start creating instances 3460 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_lang_StringValue(), Handle(), Handle(), CHECK_0); 3461 // Possible that StringValue isn't present: if so, silently don't break 3462 if (k_o != NULL) { 3463 KlassHandle k = KlassHandle(THREAD, k_o); 3464 instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); 3465 ik->initialize(CHECK_0); 3466 fieldDescriptor fd; 3467 // Possible we might not find this field: if so, silently don't break 3468 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { 3469 k()->java_mirror()->bool_field_put(fd.offset(), true); 3470 } 3471 } 3472 } 3473 } 3474 3475 // Initialize java_lang.System (needed before creating the thread) 3476 if (InitializeJavaLangSystem) { 3477 initialize_class(vmSymbols::java_lang_System(), CHECK_0); 3478 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK_0); 3479 Handle thread_group = create_initial_thread_group(CHECK_0); 3480 Universe::set_main_thread_group(thread_group()); 3481 initialize_class(vmSymbols::java_lang_Thread(), CHECK_0); 3482 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0); 3483 main_thread->set_threadObj(thread_object); 3484 // Set thread status to running since main thread has 3485 // been started and running. 3486 java_lang_Thread::set_thread_status(thread_object, 3487 java_lang_Thread::RUNNABLE); 3488 3489 // The VM preresolve methods to these classes. Make sure that get initialized 3490 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK_0); 3491 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK_0); 3492 // The VM creates & returns objects of this class. Make sure it's initialized. 3493 initialize_class(vmSymbols::java_lang_Class(), CHECK_0); 3494 call_initializeSystemClass(CHECK_0); 3495 3496 // get the Java runtime name after java.lang.System is initialized 3497 JDK_Version::set_runtime_name(get_java_runtime_name(THREAD)); 3498 JDK_Version::set_runtime_version(get_java_runtime_version(THREAD)); 3499 } else { 3500 warning("java.lang.System not initialized"); 3501 } 3502 3503 // an instance of OutOfMemory exception has been allocated earlier 3504 if (InitializeJavaLangExceptionsErrors) { 3505 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK_0); 3506 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK_0); 3507 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK_0); 3508 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK_0); 3509 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK_0); 3510 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK_0); 3511 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK_0); 3512 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK_0); 3513 } else { 3514 warning("java.lang.OutOfMemoryError has not been initialized"); 3515 warning("java.lang.NullPointerException has not been initialized"); 3516 warning("java.lang.ClassCastException has not been initialized"); 3517 warning("java.lang.ArrayStoreException has not been initialized"); 3518 warning("java.lang.ArithmeticException has not been initialized"); 3519 warning("java.lang.StackOverflowError has not been initialized"); 3520 warning("java.lang.IllegalArgumentException has not been initialized"); 3521 } 3522 } 3523 3524 // See : bugid 4211085. 3525 // Background : the static initializer of java.lang.Compiler tries to read 3526 // property"java.compiler" and read & write property "java.vm.info". 3527 // When a security manager is installed through the command line 3528 // option "-Djava.security.manager", the above properties are not 3529 // readable and the static initializer for java.lang.Compiler fails 3530 // resulting in a NoClassDefFoundError. This can happen in any 3531 // user code which calls methods in java.lang.Compiler. 3532 // Hack : the hack is to pre-load and initialize this class, so that only 3533 // system domains are on the stack when the properties are read. 3534 // Currently even the AWT code has calls to methods in java.lang.Compiler. 3535 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT. 3536 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and 3537 // read and write"java.vm.info" in the default policy file. See bugid 4211383 3538 // Once that is done, we should remove this hack. 3539 initialize_class(vmSymbols::java_lang_Compiler(), CHECK_0); 3540 3541 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to 3542 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot 3543 // compiler does not get loaded through java.lang.Compiler). "java -version" with the 3544 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here. 3545 // This should also be taken out as soon as 4211383 gets fixed. 3546 reset_vm_info_property(CHECK_0); 3547 3548 quicken_jni_functions(); 3549 3550 // Must be run after init_ft which initializes ft_enabled 3551 if (TRACE_INITIALIZE() != JNI_OK) { 3552 vm_exit_during_initialization("Failed to initialize tracing backend"); 3553 } 3554 3555 // Set flag that basic initialization has completed. Used by exceptions and various 3556 // debug stuff, that does not work until all basic classes have been initialized. 3557 set_init_completed(); 3558 3559 #ifndef USDT2 3560 HS_DTRACE_PROBE(hotspot, vm__init__end); 3561 #else /* USDT2 */ 3562 HOTSPOT_VM_INIT_END(); 3563 #endif /* USDT2 */ 3564 3565 // record VM initialization completion time 3566 #if INCLUDE_MANAGEMENT 3567 Management::record_vm_init_completed(); 3568 #endif // INCLUDE_MANAGEMENT 3569 3570 // Compute system loader. Note that this has to occur after set_init_completed, since 3571 // valid exceptions may be thrown in the process. 3572 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and 3573 // set_init_completed has just been called, causing exceptions not to be shortcut 3574 // anymore. We call vm_exit_during_initialization directly instead. 3575 SystemDictionary::compute_java_system_loader(THREAD); 3576 if (HAS_PENDING_EXCEPTION) { 3577 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); 3578 } 3579 3580 #ifndef SERIALGC 3581 // Support for ConcurrentMarkSweep. This should be cleaned up 3582 // and better encapsulated. The ugly nested if test would go away 3583 // once things are properly refactored. XXX YSR 3584 if (UseConcMarkSweepGC || UseG1GC) { 3585 if (UseConcMarkSweepGC) { 3586 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD); 3587 } else { 3588 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD); 3589 } 3590 if (HAS_PENDING_EXCEPTION) { 3591 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); 3592 } 3593 } 3594 #endif // SERIALGC 3595 3596 // Always call even when there are not JVMTI environments yet, since environments 3597 // may be attached late and JVMTI must track phases of VM execution 3598 JvmtiExport::enter_live_phase(); 3599 3600 // Signal Dispatcher needs to be started before VMInit event is posted 3601 os::signal_init(); 3602 3603 // Start Attach Listener if +StartAttachListener or it can't be started lazily 3604 if (!DisableAttachMechanism) { 3605 if (StartAttachListener || AttachListener::init_at_startup()) { 3606 AttachListener::init(); 3607 } 3608 } 3609 3610 // Launch -Xrun agents 3611 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP 3612 // back-end can launch with -Xdebug -Xrunjdwp. 3613 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) { 3614 create_vm_init_libraries(); 3615 } 3616 3617 // Notify JVMTI agents that VM initialization is complete - nop if no agents. 3618 JvmtiExport::post_vm_initialized(); 3619 3620 if (!TRACE_START()) { 3621 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); 3622 } 3623 3624 if (CleanChunkPoolAsync) { 3625 Chunk::start_chunk_pool_cleaner_task(); 3626 } 3627 3628 // initialize compiler(s) 3629 #if defined(COMPILER1) || defined(COMPILER2) || defined(SHARK) 3630 CompileBroker::compilation_init(); 3631 #endif 3632 3633 #if INCLUDE_MANAGEMENT 3634 Management::initialize(THREAD); 3635 #endif // INCLUDE_MANAGEMENT 3636 3637 if (HAS_PENDING_EXCEPTION) { 3638 // management agent fails to start possibly due to 3639 // configuration problem and is responsible for printing 3640 // stack trace if appropriate. Simply exit VM. 3641 vm_exit(1); 3642 } 3643 3644 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true); 3645 if (Arguments::has_alloc_profile()) AllocationProfiler::engage(); 3646 if (MemProfiling) MemProfiler::engage(); 3647 StatSampler::engage(); 3648 if (CheckJNICalls) JniPeriodicChecker::engage(); 3649 3650 BiasedLocking::init(); 3651 3652 if (JDK_Version::current().post_vm_init_hook_enabled()) { 3653 call_postVMInitHook(THREAD); 3654 // The Java side of PostVMInitHook.run must deal with all 3655 // exceptions and provide means of diagnosis. 3656 if (HAS_PENDING_EXCEPTION) { 3657 CLEAR_PENDING_EXCEPTION; 3658 } 3659 } 3660 3661 // Start up the WatcherThread if there are any periodic tasks 3662 // NOTE: All PeriodicTasks should be registered by now. If they 3663 // aren't, late joiners might appear to start slowly (we might 3664 // take a while to process their first tick). 3665 if (PeriodicTask::num_tasks() > 0) { 3666 WatcherThread::start(); 3667 } 3668 3669 // Give os specific code one last chance to start 3670 os::init_3(); 3671 3672 create_vm_timer.end(); 3673 #ifdef ASSERT 3674 _vm_complete = true; 3675 #endif 3676 return JNI_OK; 3677 } 3678 3679 // type for the Agent_OnLoad and JVM_OnLoad entry points 3680 extern "C" { 3681 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *); 3682 } 3683 // Find a command line agent library and return its entry point for 3684 // -agentlib: -agentpath: -Xrun 3685 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array. 3686 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) { 3687 OnLoadEntry_t on_load_entry = NULL; 3688 void *library = agent->os_lib(); // check if we have looked it up before 3689 3690 if (library == NULL) { 3691 char buffer[JVM_MAXPATHLEN]; 3692 char ebuf[1024]; 3693 const char *name = agent->name(); 3694 const char *msg = "Could not find agent library "; 3695 3696 if (agent->is_absolute_path()) { 3697 library = os::dll_load(name, ebuf, sizeof ebuf); 3698 if (library == NULL) { 3699 const char *sub_msg = " in absolute path, with error: "; 3700 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1; 3701 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread); 3702 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf); 3703 // If we can't find the agent, exit. 3704 vm_exit_during_initialization(buf, NULL); 3705 FREE_C_HEAP_ARRAY(char, buf, mtThread); 3706 } 3707 } else { 3708 // Try to load the agent from the standard dll directory 3709 os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name); 3710 library = os::dll_load(buffer, ebuf, sizeof ebuf); 3711 #ifdef KERNEL 3712 // Download instrument dll 3713 if (library == NULL && strcmp(name, "instrument") == 0) { 3714 char *props = Arguments::get_kernel_properties(); 3715 char *home = Arguments::get_java_home(); 3716 const char *fmt = "%s/bin/java %s -Dkernel.background.download=false" 3717 " sun.jkernel.DownloadManager -download client_jvm"; 3718 size_t length = strlen(props) + strlen(home) + strlen(fmt) + 1; 3719 char *cmd = NEW_C_HEAP_ARRAY(char, length, mtThread); 3720 jio_snprintf(cmd, length, fmt, home, props); 3721 int status = os::fork_and_exec(cmd); 3722 FreeHeap(props); 3723 if (status == -1) { 3724 warning(cmd); 3725 vm_exit_during_initialization("fork_and_exec failed: %s", 3726 strerror(errno)); 3727 } 3728 FREE_C_HEAP_ARRAY(char, cmd, mtThread); 3729 // when this comes back the instrument.dll should be where it belongs. 3730 library = os::dll_load(buffer, ebuf, sizeof ebuf); 3731 } 3732 #endif // KERNEL 3733 if (library == NULL) { // Try the local directory 3734 char ns[1] = {0}; 3735 os::dll_build_name(buffer, sizeof(buffer), ns, name); 3736 library = os::dll_load(buffer, ebuf, sizeof ebuf); 3737 if (library == NULL) { 3738 const char *sub_msg = " on the library path, with error: "; 3739 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1; 3740 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread); 3741 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf); 3742 // If we can't find the agent, exit. 3743 vm_exit_during_initialization(buf, NULL); 3744 FREE_C_HEAP_ARRAY(char, buf, mtThread); 3745 } 3746 } 3747 } 3748 agent->set_os_lib(library); 3749 } 3750 3751 // Find the OnLoad function. 3752 for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) { 3753 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, os::dll_lookup(library, on_load_symbols[symbol_index])); 3754 if (on_load_entry != NULL) break; 3755 } 3756 return on_load_entry; 3757 } 3758 3759 // Find the JVM_OnLoad entry point 3760 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) { 3761 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS; 3762 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); 3763 } 3764 3765 // Find the Agent_OnLoad entry point 3766 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) { 3767 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS; 3768 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); 3769 } 3770 3771 // For backwards compatibility with -Xrun 3772 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be 3773 // treated like -agentpath: 3774 // Must be called before agent libraries are created 3775 void Threads::convert_vm_init_libraries_to_agents() { 3776 AgentLibrary* agent; 3777 AgentLibrary* next; 3778 3779 for (agent = Arguments::libraries(); agent != NULL; agent = next) { 3780 next = agent->next(); // cache the next agent now as this agent may get moved off this list 3781 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); 3782 3783 // If there is an JVM_OnLoad function it will get called later, 3784 // otherwise see if there is an Agent_OnLoad 3785 if (on_load_entry == NULL) { 3786 on_load_entry = lookup_agent_on_load(agent); 3787 if (on_load_entry != NULL) { 3788 // switch it to the agent list -- so that Agent_OnLoad will be called, 3789 // JVM_OnLoad won't be attempted and Agent_OnUnload will 3790 Arguments::convert_library_to_agent(agent); 3791 } else { 3792 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name()); 3793 } 3794 } 3795 } 3796 } 3797 3798 // Create agents for -agentlib: -agentpath: and converted -Xrun 3799 // Invokes Agent_OnLoad 3800 // Called very early -- before JavaThreads exist 3801 void Threads::create_vm_init_agents() { 3802 extern struct JavaVM_ main_vm; 3803 AgentLibrary* agent; 3804 3805 JvmtiExport::enter_onload_phase(); 3806 3807 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 3808 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent); 3809 3810 if (on_load_entry != NULL) { 3811 // Invoke the Agent_OnLoad function 3812 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); 3813 if (err != JNI_OK) { 3814 vm_exit_during_initialization("agent library failed to init", agent->name()); 3815 } 3816 } else { 3817 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name()); 3818 } 3819 } 3820 JvmtiExport::enter_primordial_phase(); 3821 } 3822 3823 extern "C" { 3824 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *); 3825 } 3826 3827 void Threads::shutdown_vm_agents() { 3828 // Send any Agent_OnUnload notifications 3829 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS; 3830 extern struct JavaVM_ main_vm; 3831 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 3832 3833 // Find the Agent_OnUnload function. 3834 for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) { 3835 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t, 3836 os::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index])); 3837 3838 // Invoke the Agent_OnUnload function 3839 if (unload_entry != NULL) { 3840 JavaThread* thread = JavaThread::current(); 3841 ThreadToNativeFromVM ttn(thread); 3842 HandleMark hm(thread); 3843 (*unload_entry)(&main_vm); 3844 break; 3845 } 3846 } 3847 } 3848 } 3849 3850 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries 3851 // Invokes JVM_OnLoad 3852 void Threads::create_vm_init_libraries() { 3853 extern struct JavaVM_ main_vm; 3854 AgentLibrary* agent; 3855 3856 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) { 3857 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); 3858 3859 if (on_load_entry != NULL) { 3860 // Invoke the JVM_OnLoad function 3861 JavaThread* thread = JavaThread::current(); 3862 ThreadToNativeFromVM ttn(thread); 3863 HandleMark hm(thread); 3864 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); 3865 if (err != JNI_OK) { 3866 vm_exit_during_initialization("-Xrun library failed to init", agent->name()); 3867 } 3868 } else { 3869 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name()); 3870 } 3871 } 3872 } 3873 3874 // Last thread running calls java.lang.Shutdown.shutdown() 3875 void JavaThread::invoke_shutdown_hooks() { 3876 HandleMark hm(this); 3877 3878 // We could get here with a pending exception, if so clear it now. 3879 if (this->has_pending_exception()) { 3880 this->clear_pending_exception(); 3881 } 3882 3883 EXCEPTION_MARK; 3884 Klass* k = 3885 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(), 3886 THREAD); 3887 if (k != NULL) { 3888 // SystemDictionary::resolve_or_null will return null if there was 3889 // an exception. If we cannot load the Shutdown class, just don't 3890 // call Shutdown.shutdown() at all. This will mean the shutdown hooks 3891 // and finalizers (if runFinalizersOnExit is set) won't be run. 3892 // Note that if a shutdown hook was registered or runFinalizersOnExit 3893 // was called, the Shutdown class would have already been loaded 3894 // (Runtime.addShutdownHook and runFinalizersOnExit will load it). 3895 instanceKlassHandle shutdown_klass (THREAD, k); 3896 JavaValue result(T_VOID); 3897 JavaCalls::call_static(&result, 3898 shutdown_klass, 3899 vmSymbols::shutdown_method_name(), 3900 vmSymbols::void_method_signature(), 3901 THREAD); 3902 } 3903 CLEAR_PENDING_EXCEPTION; 3904 } 3905 3906 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when 3907 // the program falls off the end of main(). Another VM exit path is through 3908 // vm_exit() when the program calls System.exit() to return a value or when 3909 // there is a serious error in VM. The two shutdown paths are not exactly 3910 // the same, but they share Shutdown.shutdown() at Java level and before_exit() 3911 // and VM_Exit op at VM level. 3912 // 3913 // Shutdown sequence: 3914 // + Shutdown native memory tracking if it is on 3915 // + Wait until we are the last non-daemon thread to execute 3916 // <-- every thing is still working at this moment --> 3917 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level 3918 // shutdown hooks, run finalizers if finalization-on-exit 3919 // + Call before_exit(), prepare for VM exit 3920 // > run VM level shutdown hooks (they are registered through JVM_OnExit(), 3921 // currently the only user of this mechanism is File.deleteOnExit()) 3922 // > stop flat profiler, StatSampler, watcher thread, CMS threads, 3923 // post thread end and vm death events to JVMTI, 3924 // stop signal thread 3925 // + Call JavaThread::exit(), it will: 3926 // > release JNI handle blocks, remove stack guard pages 3927 // > remove this thread from Threads list 3928 // <-- no more Java code from this thread after this point --> 3929 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop 3930 // the compiler threads at safepoint 3931 // <-- do not use anything that could get blocked by Safepoint --> 3932 // + Disable tracing at JNI/JVM barriers 3933 // + Set _vm_exited flag for threads that are still running native code 3934 // + Delete this thread 3935 // + Call exit_globals() 3936 // > deletes tty 3937 // > deletes PerfMemory resources 3938 // + Return to caller 3939 3940 bool Threads::destroy_vm() { 3941 JavaThread* thread = JavaThread::current(); 3942 3943 #ifdef ASSERT 3944 _vm_complete = false; 3945 #endif 3946 // Wait until we are the last non-daemon thread to execute 3947 { MutexLocker nu(Threads_lock); 3948 while (Threads::number_of_non_daemon_threads() > 1 ) 3949 // This wait should make safepoint checks, wait without a timeout, 3950 // and wait as a suspend-equivalent condition. 3951 // 3952 // Note: If the FlatProfiler is running and this thread is waiting 3953 // for another non-daemon thread to finish, then the FlatProfiler 3954 // is waiting for the external suspend request on this thread to 3955 // complete. wait_for_ext_suspend_completion() will eventually 3956 // timeout, but that takes time. Making this wait a suspend- 3957 // equivalent condition solves that timeout problem. 3958 // 3959 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0, 3960 Mutex::_as_suspend_equivalent_flag); 3961 } 3962 3963 // Shutdown NMT before exit. Otherwise, 3964 // it will run into trouble when system destroys static variables. 3965 MemTracker::shutdown(MemTracker::NMT_normal); 3966 3967 // Hang forever on exit if we are reporting an error. 3968 if (ShowMessageBoxOnError && is_error_reported()) { 3969 os::infinite_sleep(); 3970 } 3971 os::wait_for_keypress_at_exit(); 3972 3973 if (JDK_Version::is_jdk12x_version()) { 3974 // We are the last thread running, so check if finalizers should be run. 3975 // For 1.3 or later this is done in thread->invoke_shutdown_hooks() 3976 HandleMark rm(thread); 3977 Universe::run_finalizers_on_exit(); 3978 } else { 3979 // run Java level shutdown hooks 3980 thread->invoke_shutdown_hooks(); 3981 } 3982 3983 before_exit(thread); 3984 3985 thread->exit(true); 3986 3987 // Stop VM thread. 3988 { 3989 // 4945125 The vm thread comes to a safepoint during exit. 3990 // GC vm_operations can get caught at the safepoint, and the 3991 // heap is unparseable if they are caught. Grab the Heap_lock 3992 // to prevent this. The GC vm_operations will not be able to 3993 // queue until after the vm thread is dead. 3994 // After this point, we'll never emerge out of the safepoint before 3995 // the VM exits, so concurrent GC threads do not need to be explicitly 3996 // stopped; they remain inactive until the process exits. 3997 // Note: some concurrent G1 threads may be running during a safepoint, 3998 // but these will not be accessing the heap, just some G1-specific side 3999 // data structures that are not accessed by any other threads but them 4000 // after this point in a terminal safepoint. 4001 4002 MutexLocker ml(Heap_lock); 4003 4004 VMThread::wait_for_vm_thread_exit(); 4005 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint"); 4006 VMThread::destroy(); 4007 } 4008 4009 // clean up ideal graph printers 4010 #if defined(COMPILER2) && !defined(PRODUCT) 4011 IdealGraphPrinter::clean_up(); 4012 #endif 4013 4014 // Now, all Java threads are gone except daemon threads. Daemon threads 4015 // running Java code or in VM are stopped by the Safepoint. However, 4016 // daemon threads executing native code are still running. But they 4017 // will be stopped at native=>Java/VM barriers. Note that we can't 4018 // simply kill or suspend them, as it is inherently deadlock-prone. 4019 4020 #ifndef PRODUCT 4021 // disable function tracing at JNI/JVM barriers 4022 TraceJNICalls = false; 4023 TraceJVMCalls = false; 4024 TraceRuntimeCalls = false; 4025 #endif 4026 4027 VM_Exit::set_vm_exited(); 4028 4029 notify_vm_shutdown(); 4030 4031 delete thread; 4032 4033 // exit_globals() will delete tty 4034 exit_globals(); 4035 4036 return true; 4037 } 4038 4039 4040 jboolean Threads::is_supported_jni_version_including_1_1(jint version) { 4041 if (version == JNI_VERSION_1_1) return JNI_TRUE; 4042 return is_supported_jni_version(version); 4043 } 4044 4045 4046 jboolean Threads::is_supported_jni_version(jint version) { 4047 if (version == JNI_VERSION_1_2) return JNI_TRUE; 4048 if (version == JNI_VERSION_1_4) return JNI_TRUE; 4049 if (version == JNI_VERSION_1_6) return JNI_TRUE; 4050 return JNI_FALSE; 4051 } 4052 4053 4054 void Threads::add(JavaThread* p, bool force_daemon) { 4055 // The threads lock must be owned at this point 4056 assert_locked_or_safepoint(Threads_lock); 4057 4058 // See the comment for this method in thread.hpp for its purpose and 4059 // why it is called here. 4060 p->initialize_queues(); 4061 p->set_next(_thread_list); 4062 _thread_list = p; 4063 _number_of_threads++; 4064 oop threadObj = p->threadObj(); 4065 bool daemon = true; 4066 // Bootstrapping problem: threadObj can be null for initial 4067 // JavaThread (or for threads attached via JNI) 4068 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) { 4069 _number_of_non_daemon_threads++; 4070 daemon = false; 4071 } 4072 4073 p->set_safepoint_visible(true); 4074 4075 ThreadService::add_thread(p, daemon); 4076 4077 // Possible GC point. 4078 Events::log(p, "Thread added: " INTPTR_FORMAT, p); 4079 } 4080 4081 void Threads::remove(JavaThread* p) { 4082 // Extra scope needed for Thread_lock, so we can check 4083 // that we do not remove thread without safepoint code notice 4084 { MutexLocker ml(Threads_lock); 4085 4086 assert(includes(p), "p must be present"); 4087 4088 JavaThread* current = _thread_list; 4089 JavaThread* prev = NULL; 4090 4091 while (current != p) { 4092 prev = current; 4093 current = current->next(); 4094 } 4095 4096 if (prev) { 4097 prev->set_next(current->next()); 4098 } else { 4099 _thread_list = p->next(); 4100 } 4101 _number_of_threads--; 4102 oop threadObj = p->threadObj(); 4103 bool daemon = true; 4104 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) { 4105 _number_of_non_daemon_threads--; 4106 daemon = false; 4107 4108 // Only one thread left, do a notify on the Threads_lock so a thread waiting 4109 // on destroy_vm will wake up. 4110 if (number_of_non_daemon_threads() == 1) 4111 Threads_lock->notify_all(); 4112 } 4113 ThreadService::remove_thread(p, daemon); 4114 4115 // Make sure that safepoint code disregard this thread. This is needed since 4116 // the thread might mess around with locks after this point. This can cause it 4117 // to do callbacks into the safepoint code. However, the safepoint code is not aware 4118 // of this thread since it is removed from the queue. 4119 p->set_terminated_value(); 4120 4121 // Now, this thread is not visible to safepoint 4122 p->set_safepoint_visible(false); 4123 // once the thread becomes safepoint invisible, we can not use its per-thread 4124 // recorder. And Threads::do_threads() no longer walks this thread, so we have 4125 // to release its per-thread recorder here. 4126 MemTracker::thread_exiting(p); 4127 } // unlock Threads_lock 4128 4129 // Since Events::log uses a lock, we grab it outside the Threads_lock 4130 Events::log(p, "Thread exited: " INTPTR_FORMAT, p); 4131 } 4132 4133 // Threads_lock must be held when this is called (or must be called during a safepoint) 4134 bool Threads::includes(JavaThread* p) { 4135 assert(Threads_lock->is_locked(), "sanity check"); 4136 ALL_JAVA_THREADS(q) { 4137 if (q == p ) { 4138 return true; 4139 } 4140 } 4141 return false; 4142 } 4143 4144 // Operations on the Threads list for GC. These are not explicitly locked, 4145 // but the garbage collector must provide a safe context for them to run. 4146 // In particular, these things should never be called when the Threads_lock 4147 // is held by some other thread. (Note: the Safepoint abstraction also 4148 // uses the Threads_lock to gurantee this property. It also makes sure that 4149 // all threads gets blocked when exiting or starting). 4150 4151 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) { 4152 ALL_JAVA_THREADS(p) { 4153 p->oops_do(f, cf); 4154 } 4155 VMThread::vm_thread()->oops_do(f, cf); 4156 } 4157 4158 void Threads::possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf) { 4159 // Introduce a mechanism allowing parallel threads to claim threads as 4160 // root groups. Overhead should be small enough to use all the time, 4161 // even in sequential code. 4162 SharedHeap* sh = SharedHeap::heap(); 4163 // Cannot yet substitute active_workers for n_par_threads 4164 // because of G1CollectedHeap::verify() use of 4165 // SharedHeap::process_strong_roots(). n_par_threads == 0 will 4166 // turn off parallelism in process_strong_roots while active_workers 4167 // is being used for parallelism elsewhere. 4168 bool is_par = sh->n_par_threads() > 0; 4169 assert(!is_par || 4170 (SharedHeap::heap()->n_par_threads() == 4171 SharedHeap::heap()->workers()->active_workers()), "Mismatch"); 4172 int cp = SharedHeap::heap()->strong_roots_parity(); 4173 ALL_JAVA_THREADS(p) { 4174 if (p->claim_oops_do(is_par, cp)) { 4175 p->oops_do(f, cf); 4176 } 4177 } 4178 VMThread* vmt = VMThread::vm_thread(); 4179 if (vmt->claim_oops_do(is_par, cp)) { 4180 vmt->oops_do(f, cf); 4181 } 4182 } 4183 4184 #ifndef SERIALGC 4185 // Used by ParallelScavenge 4186 void Threads::create_thread_roots_tasks(GCTaskQueue* q) { 4187 ALL_JAVA_THREADS(p) { 4188 q->enqueue(new ThreadRootsTask(p)); 4189 } 4190 q->enqueue(new ThreadRootsTask(VMThread::vm_thread())); 4191 } 4192 4193 // Used by Parallel Old 4194 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) { 4195 ALL_JAVA_THREADS(p) { 4196 q->enqueue(new ThreadRootsMarkingTask(p)); 4197 } 4198 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread())); 4199 } 4200 #endif // SERIALGC 4201 4202 void Threads::nmethods_do(CodeBlobClosure* cf) { 4203 ALL_JAVA_THREADS(p) { 4204 p->nmethods_do(cf); 4205 } 4206 VMThread::vm_thread()->nmethods_do(cf); 4207 } 4208 4209 void Threads::metadata_do(void f(Metadata*)) { 4210 ALL_JAVA_THREADS(p) { 4211 p->metadata_do(f); 4212 } 4213 } 4214 4215 void Threads::gc_epilogue() { 4216 ALL_JAVA_THREADS(p) { 4217 p->gc_epilogue(); 4218 } 4219 } 4220 4221 void Threads::gc_prologue() { 4222 ALL_JAVA_THREADS(p) { 4223 p->gc_prologue(); 4224 } 4225 } 4226 4227 void Threads::deoptimized_wrt_marked_nmethods() { 4228 ALL_JAVA_THREADS(p) { 4229 p->deoptimized_wrt_marked_nmethods(); 4230 } 4231 } 4232 4233 4234 // Get count Java threads that are waiting to enter the specified monitor. 4235 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count, 4236 address monitor, bool doLock) { 4237 assert(doLock || SafepointSynchronize::is_at_safepoint(), 4238 "must grab Threads_lock or be at safepoint"); 4239 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count); 4240 4241 int i = 0; 4242 { 4243 MutexLockerEx ml(doLock ? Threads_lock : NULL); 4244 ALL_JAVA_THREADS(p) { 4245 if (p->is_Compiler_thread()) continue; 4246 4247 address pending = (address)p->current_pending_monitor(); 4248 if (pending == monitor) { // found a match 4249 if (i < count) result->append(p); // save the first count matches 4250 i++; 4251 } 4252 } 4253 } 4254 return result; 4255 } 4256 4257 4258 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) { 4259 assert(doLock || 4260 Threads_lock->owned_by_self() || 4261 SafepointSynchronize::is_at_safepoint(), 4262 "must grab Threads_lock or be at safepoint"); 4263 4264 // NULL owner means not locked so we can skip the search 4265 if (owner == NULL) return NULL; 4266 4267 { 4268 MutexLockerEx ml(doLock ? Threads_lock : NULL); 4269 ALL_JAVA_THREADS(p) { 4270 // first, see if owner is the address of a Java thread 4271 if (owner == (address)p) return p; 4272 } 4273 } 4274 assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled"); 4275 if (UseHeavyMonitors) return NULL; 4276 4277 // 4278 // If we didn't find a matching Java thread and we didn't force use of 4279 // heavyweight monitors, then the owner is the stack address of the 4280 // Lock Word in the owning Java thread's stack. 4281 // 4282 JavaThread* the_owner = NULL; 4283 { 4284 MutexLockerEx ml(doLock ? Threads_lock : NULL); 4285 ALL_JAVA_THREADS(q) { 4286 if (q->is_lock_owned(owner)) { 4287 the_owner = q; 4288 break; 4289 } 4290 } 4291 } 4292 assert(the_owner != NULL, "Did not find owning Java thread for lock word address"); 4293 return the_owner; 4294 } 4295 4296 // Threads::print_on() is called at safepoint by VM_PrintThreads operation. 4297 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) { 4298 char buf[32]; 4299 st->print_cr(os::local_time_string(buf, sizeof(buf))); 4300 4301 st->print_cr("Full thread dump %s (%s %s):", 4302 Abstract_VM_Version::vm_name(), 4303 Abstract_VM_Version::vm_release(), 4304 Abstract_VM_Version::vm_info_string() 4305 ); 4306 st->cr(); 4307 4308 #ifndef SERIALGC 4309 // Dump concurrent locks 4310 ConcurrentLocksDump concurrent_locks; 4311 if (print_concurrent_locks) { 4312 concurrent_locks.dump_at_safepoint(); 4313 } 4314 #endif // SERIALGC 4315 4316 ALL_JAVA_THREADS(p) { 4317 ResourceMark rm; 4318 p->print_on(st); 4319 if (print_stacks) { 4320 if (internal_format) { 4321 p->trace_stack(); 4322 } else { 4323 p->print_stack_on(st); 4324 } 4325 } 4326 st->cr(); 4327 #ifndef SERIALGC 4328 if (print_concurrent_locks) { 4329 concurrent_locks.print_locks_on(p, st); 4330 } 4331 #endif // SERIALGC 4332 } 4333 4334 VMThread::vm_thread()->print_on(st); 4335 st->cr(); 4336 Universe::heap()->print_gc_threads_on(st); 4337 WatcherThread* wt = WatcherThread::watcher_thread(); 4338 if (wt != NULL) { 4339 wt->print_on(st); 4340 st->cr(); 4341 } 4342 CompileBroker::print_compiler_threads_on(st); 4343 st->flush(); 4344 } 4345 4346 // Threads::print_on_error() is called by fatal error handler. It's possible 4347 // that VM is not at safepoint and/or current thread is inside signal handler. 4348 // Don't print stack trace, as the stack may not be walkable. Don't allocate 4349 // memory (even in resource area), it might deadlock the error handler. 4350 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) { 4351 bool found_current = false; 4352 st->print_cr("Java Threads: ( => current thread )"); 4353 ALL_JAVA_THREADS(thread) { 4354 bool is_current = (current == thread); 4355 found_current = found_current || is_current; 4356 4357 st->print("%s", is_current ? "=>" : " "); 4358 4359 st->print(PTR_FORMAT, thread); 4360 st->print(" "); 4361 thread->print_on_error(st, buf, buflen); 4362 st->cr(); 4363 } 4364 st->cr(); 4365 4366 st->print_cr("Other Threads:"); 4367 if (VMThread::vm_thread()) { 4368 bool is_current = (current == VMThread::vm_thread()); 4369 found_current = found_current || is_current; 4370 st->print("%s", current == VMThread::vm_thread() ? "=>" : " "); 4371 4372 st->print(PTR_FORMAT, VMThread::vm_thread()); 4373 st->print(" "); 4374 VMThread::vm_thread()->print_on_error(st, buf, buflen); 4375 st->cr(); 4376 } 4377 WatcherThread* wt = WatcherThread::watcher_thread(); 4378 if (wt != NULL) { 4379 bool is_current = (current == wt); 4380 found_current = found_current || is_current; 4381 st->print("%s", is_current ? "=>" : " "); 4382 4383 st->print(PTR_FORMAT, wt); 4384 st->print(" "); 4385 wt->print_on_error(st, buf, buflen); 4386 st->cr(); 4387 } 4388 if (!found_current) { 4389 st->cr(); 4390 st->print("=>" PTR_FORMAT " (exited) ", current); 4391 current->print_on_error(st, buf, buflen); 4392 st->cr(); 4393 } 4394 } 4395 4396 // Internal SpinLock and Mutex 4397 // Based on ParkEvent 4398 4399 // Ad-hoc mutual exclusion primitives: SpinLock and Mux 4400 // 4401 // We employ SpinLocks _only for low-contention, fixed-length 4402 // short-duration critical sections where we're concerned 4403 // about native mutex_t or HotSpot Mutex:: latency. 4404 // The mux construct provides a spin-then-block mutual exclusion 4405 // mechanism. 4406 // 4407 // Testing has shown that contention on the ListLock guarding gFreeList 4408 // is common. If we implement ListLock as a simple SpinLock it's common 4409 // for the JVM to devolve to yielding with little progress. This is true 4410 // despite the fact that the critical sections protected by ListLock are 4411 // extremely short. 4412 // 4413 // TODO-FIXME: ListLock should be of type SpinLock. 4414 // We should make this a 1st-class type, integrated into the lock 4415 // hierarchy as leaf-locks. Critically, the SpinLock structure 4416 // should have sufficient padding to avoid false-sharing and excessive 4417 // cache-coherency traffic. 4418 4419 4420 typedef volatile int SpinLockT ; 4421 4422 void Thread::SpinAcquire (volatile int * adr, const char * LockName) { 4423 if (Atomic::cmpxchg (1, adr, 0) == 0) { 4424 return ; // normal fast-path return 4425 } 4426 4427 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy. 4428 TEVENT (SpinAcquire - ctx) ; 4429 int ctr = 0 ; 4430 int Yields = 0 ; 4431 for (;;) { 4432 while (*adr != 0) { 4433 ++ctr ; 4434 if ((ctr & 0xFFF) == 0 || !os::is_MP()) { 4435 if (Yields > 5) { 4436 // Consider using a simple NakedSleep() instead. 4437 // Then SpinAcquire could be called by non-JVM threads 4438 Thread::current()->_ParkEvent->park(1) ; 4439 } else { 4440 os::NakedYield() ; 4441 ++Yields ; 4442 } 4443 } else { 4444 SpinPause() ; 4445 } 4446 } 4447 if (Atomic::cmpxchg (1, adr, 0) == 0) return ; 4448 } 4449 } 4450 4451 void Thread::SpinRelease (volatile int * adr) { 4452 assert (*adr != 0, "invariant") ; 4453 OrderAccess::fence() ; // guarantee at least release consistency. 4454 // Roach-motel semantics. 4455 // It's safe if subsequent LDs and STs float "up" into the critical section, 4456 // but prior LDs and STs within the critical section can't be allowed 4457 // to reorder or float past the ST that releases the lock. 4458 *adr = 0 ; 4459 } 4460 4461 // muxAcquire and muxRelease: 4462 // 4463 // * muxAcquire and muxRelease support a single-word lock-word construct. 4464 // The LSB of the word is set IFF the lock is held. 4465 // The remainder of the word points to the head of a singly-linked list 4466 // of threads blocked on the lock. 4467 // 4468 // * The current implementation of muxAcquire-muxRelease uses its own 4469 // dedicated Thread._MuxEvent instance. If we're interested in 4470 // minimizing the peak number of extant ParkEvent instances then 4471 // we could eliminate _MuxEvent and "borrow" _ParkEvent as long 4472 // as certain invariants were satisfied. Specifically, care would need 4473 // to be taken with regards to consuming unpark() "permits". 4474 // A safe rule of thumb is that a thread would never call muxAcquire() 4475 // if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently 4476 // park(). Otherwise the _ParkEvent park() operation in muxAcquire() could 4477 // consume an unpark() permit intended for monitorenter, for instance. 4478 // One way around this would be to widen the restricted-range semaphore 4479 // implemented in park(). Another alternative would be to provide 4480 // multiple instances of the PlatformEvent() for each thread. One 4481 // instance would be dedicated to muxAcquire-muxRelease, for instance. 4482 // 4483 // * Usage: 4484 // -- Only as leaf locks 4485 // -- for short-term locking only as muxAcquire does not perform 4486 // thread state transitions. 4487 // 4488 // Alternatives: 4489 // * We could implement muxAcquire and muxRelease with MCS or CLH locks 4490 // but with parking or spin-then-park instead of pure spinning. 4491 // * Use Taura-Oyama-Yonenzawa locks. 4492 // * It's possible to construct a 1-0 lock if we encode the lockword as 4493 // (List,LockByte). Acquire will CAS the full lockword while Release 4494 // will STB 0 into the LockByte. The 1-0 scheme admits stranding, so 4495 // acquiring threads use timers (ParkTimed) to detect and recover from 4496 // the stranding window. Thread/Node structures must be aligned on 256-byte 4497 // boundaries by using placement-new. 4498 // * Augment MCS with advisory back-link fields maintained with CAS(). 4499 // Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner. 4500 // The validity of the backlinks must be ratified before we trust the value. 4501 // If the backlinks are invalid the exiting thread must back-track through the 4502 // the forward links, which are always trustworthy. 4503 // * Add a successor indication. The LockWord is currently encoded as 4504 // (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable 4505 // to provide the usual futile-wakeup optimization. 4506 // See RTStt for details. 4507 // * Consider schedctl.sc_nopreempt to cover the critical section. 4508 // 4509 4510 4511 typedef volatile intptr_t MutexT ; // Mux Lock-word 4512 enum MuxBits { LOCKBIT = 1 } ; 4513 4514 void Thread::muxAcquire (volatile intptr_t * Lock, const char * LockName) { 4515 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ; 4516 if (w == 0) return ; 4517 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { 4518 return ; 4519 } 4520 4521 TEVENT (muxAcquire - Contention) ; 4522 ParkEvent * const Self = Thread::current()->_MuxEvent ; 4523 assert ((intptr_t(Self) & LOCKBIT) == 0, "invariant") ; 4524 for (;;) { 4525 int its = (os::is_MP() ? 100 : 0) + 1 ; 4526 4527 // Optional spin phase: spin-then-park strategy 4528 while (--its >= 0) { 4529 w = *Lock ; 4530 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { 4531 return ; 4532 } 4533 } 4534 4535 Self->reset() ; 4536 Self->OnList = intptr_t(Lock) ; 4537 // The following fence() isn't _strictly necessary as the subsequent 4538 // CAS() both serializes execution and ratifies the fetched *Lock value. 4539 OrderAccess::fence(); 4540 for (;;) { 4541 w = *Lock ; 4542 if ((w & LOCKBIT) == 0) { 4543 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { 4544 Self->OnList = 0 ; // hygiene - allows stronger asserts 4545 return ; 4546 } 4547 continue ; // Interference -- *Lock changed -- Just retry 4548 } 4549 assert (w & LOCKBIT, "invariant") ; 4550 Self->ListNext = (ParkEvent *) (w & ~LOCKBIT ); 4551 if (Atomic::cmpxchg_ptr (intptr_t(Self)|LOCKBIT, Lock, w) == w) break ; 4552 } 4553 4554 while (Self->OnList != 0) { 4555 Self->park() ; 4556 } 4557 } 4558 } 4559 4560 void Thread::muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) { 4561 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ; 4562 if (w == 0) return ; 4563 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { 4564 return ; 4565 } 4566 4567 TEVENT (muxAcquire - Contention) ; 4568 ParkEvent * ReleaseAfter = NULL ; 4569 if (ev == NULL) { 4570 ev = ReleaseAfter = ParkEvent::Allocate (NULL) ; 4571 } 4572 assert ((intptr_t(ev) & LOCKBIT) == 0, "invariant") ; 4573 for (;;) { 4574 guarantee (ev->OnList == 0, "invariant") ; 4575 int its = (os::is_MP() ? 100 : 0) + 1 ; 4576 4577 // Optional spin phase: spin-then-park strategy 4578 while (--its >= 0) { 4579 w = *Lock ; 4580 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { 4581 if (ReleaseAfter != NULL) { 4582 ParkEvent::Release (ReleaseAfter) ; 4583 } 4584 return ; 4585 } 4586 } 4587 4588 ev->reset() ; 4589 ev->OnList = intptr_t(Lock) ; 4590 // The following fence() isn't _strictly necessary as the subsequent 4591 // CAS() both serializes execution and ratifies the fetched *Lock value. 4592 OrderAccess::fence(); 4593 for (;;) { 4594 w = *Lock ; 4595 if ((w & LOCKBIT) == 0) { 4596 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { 4597 ev->OnList = 0 ; 4598 // We call ::Release while holding the outer lock, thus 4599 // artificially lengthening the critical section. 4600 // Consider deferring the ::Release() until the subsequent unlock(), 4601 // after we've dropped the outer lock. 4602 if (ReleaseAfter != NULL) { 4603 ParkEvent::Release (ReleaseAfter) ; 4604 } 4605 return ; 4606 } 4607 continue ; // Interference -- *Lock changed -- Just retry 4608 } 4609 assert (w & LOCKBIT, "invariant") ; 4610 ev->ListNext = (ParkEvent *) (w & ~LOCKBIT ); 4611 if (Atomic::cmpxchg_ptr (intptr_t(ev)|LOCKBIT, Lock, w) == w) break ; 4612 } 4613 4614 while (ev->OnList != 0) { 4615 ev->park() ; 4616 } 4617 } 4618 } 4619 4620 // Release() must extract a successor from the list and then wake that thread. 4621 // It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme 4622 // similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based 4623 // Release() would : 4624 // (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list. 4625 // (B) Extract a successor from the private list "in-hand" 4626 // (C) attempt to CAS() the residual back into *Lock over null. 4627 // If there were any newly arrived threads and the CAS() would fail. 4628 // In that case Release() would detach the RATs, re-merge the list in-hand 4629 // with the RATs and repeat as needed. Alternately, Release() might 4630 // detach and extract a successor, but then pass the residual list to the wakee. 4631 // The wakee would be responsible for reattaching and remerging before it 4632 // competed for the lock. 4633 // 4634 // Both "pop" and DMR are immune from ABA corruption -- there can be 4635 // multiple concurrent pushers, but only one popper or detacher. 4636 // This implementation pops from the head of the list. This is unfair, 4637 // but tends to provide excellent throughput as hot threads remain hot. 4638 // (We wake recently run threads first). 4639 4640 void Thread::muxRelease (volatile intptr_t * Lock) { 4641 for (;;) { 4642 const intptr_t w = Atomic::cmpxchg_ptr (0, Lock, LOCKBIT) ; 4643 assert (w & LOCKBIT, "invariant") ; 4644 if (w == LOCKBIT) return ; 4645 ParkEvent * List = (ParkEvent *) (w & ~LOCKBIT) ; 4646 assert (List != NULL, "invariant") ; 4647 assert (List->OnList == intptr_t(Lock), "invariant") ; 4648 ParkEvent * nxt = List->ListNext ; 4649 4650 // The following CAS() releases the lock and pops the head element. 4651 if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) { 4652 continue ; 4653 } 4654 List->OnList = 0 ; 4655 OrderAccess::fence() ; 4656 List->unpark () ; 4657 return ; 4658 } 4659 } 4660 4661 4662 void Threads::verify() { 4663 ALL_JAVA_THREADS(p) { 4664 p->verify(); 4665 } 4666 VMThread* thread = VMThread::vm_thread(); 4667 if (thread != NULL) thread->verify(); 4668 }