Mercurial > hg > graal-jvmci-8
view src/share/vm/runtime/mutexLocker.cpp @ 1716:be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode.
Reviewed-by: chrisphi, johnc, poonam
author | ysr |
---|---|
date | Mon, 16 Aug 2010 15:58:42 -0700 |
parents | 4e5661ba9d98 |
children | f95d63e2154a |
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/* * Copyright (c) 1997, 2009, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "incls/_precompiled.incl" #include "incls/_mutexLocker.cpp.incl" // Mutexes used in the VM (see comment in mutexLocker.hpp): // // Note that the following pointers are effectively final -- after having been // set at JVM startup-time, they should never be subsequently mutated. // Instead of using pointers to malloc()ed monitors and mutexes we should consider // eliminating the indirection and using instances instead. // Consider using GCC's __read_mostly. Mutex* Patching_lock = NULL; Monitor* SystemDictionary_lock = NULL; Mutex* PackageTable_lock = NULL; Mutex* CompiledIC_lock = NULL; Mutex* InlineCacheBuffer_lock = NULL; Mutex* VMStatistic_lock = NULL; Mutex* JNIGlobalHandle_lock = NULL; Mutex* JNIHandleBlockFreeList_lock = NULL; Mutex* JNICachedItableIndex_lock = NULL; Mutex* JmethodIdCreation_lock = NULL; Mutex* JfieldIdCreation_lock = NULL; Monitor* JNICritical_lock = NULL; Mutex* JvmtiThreadState_lock = NULL; Monitor* JvmtiPendingEvent_lock = NULL; Monitor* Heap_lock = NULL; Mutex* ExpandHeap_lock = NULL; Mutex* AdapterHandlerLibrary_lock = NULL; Mutex* SignatureHandlerLibrary_lock = NULL; Mutex* VtableStubs_lock = NULL; Mutex* SymbolTable_lock = NULL; Mutex* StringTable_lock = NULL; Mutex* CodeCache_lock = NULL; Mutex* MethodData_lock = NULL; Mutex* RetData_lock = NULL; Monitor* VMOperationQueue_lock = NULL; Monitor* VMOperationRequest_lock = NULL; Monitor* Safepoint_lock = NULL; Monitor* SerializePage_lock = NULL; Monitor* Threads_lock = NULL; Monitor* CGC_lock = NULL; Mutex* STS_init_lock = NULL; Monitor* SLT_lock = NULL; Monitor* iCMS_lock = NULL; Monitor* FullGCCount_lock = NULL; Monitor* CMark_lock = NULL; Monitor* ZF_mon = NULL; Monitor* Cleanup_mon = NULL; Mutex* CMRegionStack_lock = NULL; Mutex* SATB_Q_FL_lock = NULL; Monitor* SATB_Q_CBL_mon = NULL; Mutex* Shared_SATB_Q_lock = NULL; Mutex* DirtyCardQ_FL_lock = NULL; Monitor* DirtyCardQ_CBL_mon = NULL; Mutex* Shared_DirtyCardQ_lock = NULL; Mutex* ParGCRareEvent_lock = NULL; Mutex* EvacFailureStack_lock = NULL; Mutex* DerivedPointerTableGC_lock = NULL; Mutex* Compile_lock = NULL; Monitor* MethodCompileQueue_lock = NULL; Monitor* CompileThread_lock = NULL; Mutex* CompileTaskAlloc_lock = NULL; Mutex* CompileStatistics_lock = NULL; Mutex* MultiArray_lock = NULL; Monitor* Terminator_lock = NULL; Monitor* BeforeExit_lock = NULL; Monitor* Notify_lock = NULL; Monitor* Interrupt_lock = NULL; Monitor* ProfileVM_lock = NULL; Mutex* ProfilePrint_lock = NULL; Mutex* ExceptionCache_lock = NULL; Monitor* ObjAllocPost_lock = NULL; Mutex* OsrList_lock = NULL; #ifndef PRODUCT Mutex* FullGCALot_lock = NULL; #endif Mutex* Debug1_lock = NULL; Mutex* Debug2_lock = NULL; Mutex* Debug3_lock = NULL; Mutex* tty_lock = NULL; Mutex* RawMonitor_lock = NULL; Mutex* PerfDataMemAlloc_lock = NULL; Mutex* PerfDataManager_lock = NULL; Mutex* OopMapCacheAlloc_lock = NULL; Mutex* MMUTracker_lock = NULL; Mutex* HotCardCache_lock = NULL; Monitor* GCTaskManager_lock = NULL; Mutex* Management_lock = NULL; Monitor* LowMemory_lock = NULL; #define MAX_NUM_MUTEX 128 static Monitor * _mutex_array[MAX_NUM_MUTEX]; static int _num_mutex; #ifdef ASSERT void assert_locked_or_safepoint(const Monitor * lock) { // check if this thread owns the lock (common case) if (IgnoreLockingAssertions) return; assert(lock != NULL, "Need non-NULL lock"); if (lock->owned_by_self()) return; if (SafepointSynchronize::is_at_safepoint()) return; if (!Universe::is_fully_initialized()) return; // see if invoker of VM operation owns it VM_Operation* op = VMThread::vm_operation(); if (op != NULL && op->calling_thread() == lock->owner()) return; fatal(err_msg("must own lock %s", lock->name())); } // a stronger assertion than the above void assert_lock_strong(const Monitor * lock) { if (IgnoreLockingAssertions) return; assert(lock != NULL, "Need non-NULL lock"); if (lock->owned_by_self()) return; fatal(err_msg("must own lock %s", lock->name())); } #endif #define def(var, type, pri, vm_block) { \ var = new type(Mutex::pri, #var, vm_block); \ assert(_num_mutex < MAX_NUM_MUTEX, \ "increase MAX_NUM_MUTEX"); \ _mutex_array[_num_mutex++] = var; \ } void mutex_init() { def(tty_lock , Mutex , event, true ); // allow to lock in VM def(CGC_lock , Monitor, special, true ); // coordinate between fore- and background GC def(STS_init_lock , Mutex, leaf, true ); if (UseConcMarkSweepGC) { def(iCMS_lock , Monitor, special, true ); // CMS incremental mode start/stop notification } if (UseConcMarkSweepGC || UseG1GC) { def(FullGCCount_lock , Monitor, leaf, true ); // in support of ExplicitGCInvokesConcurrent } if (UseG1GC) { def(CMark_lock , Monitor, nonleaf, true ); // coordinate concurrent mark thread def(ZF_mon , Monitor, leaf, true ); def(Cleanup_mon , Monitor, nonleaf, true ); def(CMRegionStack_lock , Mutex, leaf, true ); def(SATB_Q_FL_lock , Mutex , special, true ); def(SATB_Q_CBL_mon , Monitor, nonleaf, true ); def(Shared_SATB_Q_lock , Mutex, nonleaf, true ); def(DirtyCardQ_FL_lock , Mutex , special, true ); def(DirtyCardQ_CBL_mon , Monitor, nonleaf, true ); def(Shared_DirtyCardQ_lock , Mutex, nonleaf, true ); def(MMUTracker_lock , Mutex , leaf , true ); def(HotCardCache_lock , Mutex , special , true ); def(EvacFailureStack_lock , Mutex , nonleaf , true ); } def(ParGCRareEvent_lock , Mutex , leaf , true ); def(DerivedPointerTableGC_lock , Mutex, leaf, true ); def(CodeCache_lock , Mutex , special, true ); def(Interrupt_lock , Monitor, special, true ); // used for interrupt processing def(RawMonitor_lock , Mutex, special, true ); def(OopMapCacheAlloc_lock , Mutex, leaf, true ); // used for oop_map_cache allocation. def(Patching_lock , Mutex , special, true ); // used for safepointing and code patching. def(ObjAllocPost_lock , Monitor, special, false); def(LowMemory_lock , Monitor, special, true ); // used for low memory detection def(JmethodIdCreation_lock , Mutex , leaf, true ); // used for creating jmethodIDs. def(SystemDictionary_lock , Monitor, leaf, true ); // lookups done by VM thread def(PackageTable_lock , Mutex , leaf, false); def(InlineCacheBuffer_lock , Mutex , leaf, true ); def(VMStatistic_lock , Mutex , leaf, false); def(ExpandHeap_lock , Mutex , leaf, true ); // Used during compilation by VM thread def(JNIHandleBlockFreeList_lock , Mutex , leaf, true ); // handles are used by VM thread def(SignatureHandlerLibrary_lock , Mutex , leaf, false); def(SymbolTable_lock , Mutex , leaf, true ); def(StringTable_lock , Mutex , leaf, true ); def(ProfilePrint_lock , Mutex , leaf, false); // serial profile printing def(ExceptionCache_lock , Mutex , leaf, false); // serial profile printing def(OsrList_lock , Mutex , leaf, true ); def(Debug1_lock , Mutex , leaf, true ); #ifndef PRODUCT def(FullGCALot_lock , Mutex , leaf, false); // a lock to make FullGCALot MT safe #endif def(BeforeExit_lock , Monitor, leaf, true ); def(PerfDataMemAlloc_lock , Mutex , leaf, true ); // used for allocating PerfData memory for performance data def(PerfDataManager_lock , Mutex , leaf, true ); // used for synchronized access to PerfDataManager resources // CMS_modUnionTable_lock leaf // CMS_bitMap_lock leaf + 1 // CMS_freeList_lock leaf + 2 def(Safepoint_lock , Monitor, safepoint, true ); // locks SnippetCache_lock/Threads_lock def(Threads_lock , Monitor, barrier, true ); def(VMOperationQueue_lock , Monitor, nonleaf, true ); // VM_thread allowed to block on these def(VMOperationRequest_lock , Monitor, nonleaf, true ); def(RetData_lock , Mutex , nonleaf, false); def(Terminator_lock , Monitor, nonleaf, true ); def(VtableStubs_lock , Mutex , nonleaf, true ); def(Notify_lock , Monitor, nonleaf, true ); def(JNIGlobalHandle_lock , Mutex , nonleaf, true ); // locks JNIHandleBlockFreeList_lock def(JNICritical_lock , Monitor, nonleaf, true ); // used for JNI critical regions def(AdapterHandlerLibrary_lock , Mutex , nonleaf, true); if (UseConcMarkSweepGC) { def(SLT_lock , Monitor, nonleaf, false ); // used in CMS GC for locking PLL lock } def(Heap_lock , Monitor, nonleaf+1, false); def(JfieldIdCreation_lock , Mutex , nonleaf+1, true ); // jfieldID, Used in VM_Operation def(JNICachedItableIndex_lock , Mutex , nonleaf+1, false); // Used to cache an itable index during JNI invoke def(CompiledIC_lock , Mutex , nonleaf+2, false); // locks VtableStubs_lock, InlineCacheBuffer_lock def(CompileTaskAlloc_lock , Mutex , nonleaf+2, true ); def(CompileStatistics_lock , Mutex , nonleaf+2, false); def(MultiArray_lock , Mutex , nonleaf+2, false); // locks SymbolTable_lock def(JvmtiThreadState_lock , Mutex , nonleaf+2, false); // Used by JvmtiThreadState/JvmtiEventController def(JvmtiPendingEvent_lock , Monitor, nonleaf, false); // Used by JvmtiCodeBlobEvents def(Management_lock , Mutex , nonleaf+2, false); // used for JVM management def(Compile_lock , Mutex , nonleaf+3, true ); def(MethodData_lock , Mutex , nonleaf+3, false); def(MethodCompileQueue_lock , Monitor, nonleaf+4, true ); def(Debug2_lock , Mutex , nonleaf+4, true ); def(Debug3_lock , Mutex , nonleaf+4, true ); def(ProfileVM_lock , Monitor, nonleaf+4, false); // used for profiling of the VMThread def(CompileThread_lock , Monitor, nonleaf+5, false ); } GCMutexLocker::GCMutexLocker(Monitor * mutex) { if (SafepointSynchronize::is_at_safepoint()) { _locked = false; } else { _mutex = mutex; _locked = true; _mutex->lock(); } } // Print all mutexes/monitors that are currently owned by a thread; called // by fatal error handler. void print_owned_locks_on_error(outputStream* st) { st->print("VM Mutex/Monitor currently owned by a thread: "); bool none = true; for (int i = 0; i < _num_mutex; i++) { // see if it has an owner if (_mutex_array[i]->owner() != NULL) { if (none) { // print format used by Mutex::print_on_error() st->print_cr(" ([mutex/lock_event])"); none = false; } _mutex_array[i]->print_on_error(st); st->cr(); } } if (none) st->print_cr("None"); }