/* * Copyright (c) 1997, 2020, 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 "precompiled.hpp" #include "memory/universe.hpp" #include "runtime/mutexLocker.hpp" #include "runtime/os.inline.hpp" #include "runtime/safepoint.hpp" #include "runtime/thread.inline.hpp" #include "runtime/vmThread.hpp" // 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; Mutex* CompiledMethod_lock = NULL; Monitor* SystemDictionary_lock = NULL; Mutex* ProtectionDomainSet_lock = NULL; Mutex* SharedDictionary_lock = NULL; Mutex* Module_lock = NULL; Mutex* CompiledIC_lock = NULL; Mutex* InlineCacheBuffer_lock = NULL; Mutex* VMStatistic_lock = NULL; Mutex* JNIHandleBlockFreeList_lock = NULL; Mutex* JmethodIdCreation_lock = NULL; Mutex* JfieldIdCreation_lock = NULL; Monitor* JNICritical_lock = NULL; Mutex* JvmtiThreadState_lock = NULL; Monitor* Heap_lock = NULL; Mutex* ExpandHeap_lock = NULL; Mutex* AdapterHandlerLibrary_lock = NULL; Mutex* SignatureHandlerLibrary_lock = NULL; Mutex* VtableStubs_lock = NULL; Mutex* SymbolArena_lock = NULL; Monitor* StringDedupQueue_lock = NULL; Mutex* StringDedupTable_lock = NULL; Monitor* CodeCache_lock = NULL; Monitor* CodeSweeper_lock = NULL; Mutex* MethodData_lock = NULL; Mutex* TouchedMethodLog_lock = NULL; Mutex* RetData_lock = NULL; Monitor* VMOperationQueue_lock = NULL; Monitor* VMOperationRequest_lock = NULL; Monitor* Threads_lock = NULL; Mutex* NonJavaThreadsList_lock = NULL; Mutex* NonJavaThreadsListSync_lock = NULL; Monitor* CGC_lock = NULL; Monitor* STS_lock = NULL; Monitor* FullGCCount_lock = NULL; Monitor* G1OldGCCount_lock = NULL; Mutex* Shared_DirtyCardQ_lock = NULL; Mutex* G1DetachedRefinementStats_lock = NULL; Mutex* MarkStackFreeList_lock = NULL; Mutex* MarkStackChunkList_lock = NULL; Mutex* MonitoringSupport_lock = NULL; Mutex* ParGCRareEvent_lock = NULL; Monitor* ConcurrentGCBreakpoints_lock = NULL; Mutex* Compile_lock = NULL; Monitor* MethodCompileQueue_lock = NULL; Monitor* CompileThread_lock = NULL; Monitor* Compilation_lock = NULL; Mutex* CompileTaskAlloc_lock = NULL; Mutex* CompileStatistics_lock = NULL; Mutex* DirectivesStack_lock = NULL; Mutex* MultiArray_lock = NULL; Monitor* Terminator_lock = NULL; Monitor* InitCompleted_lock = NULL; Monitor* BeforeExit_lock = NULL; Monitor* Notify_lock = NULL; Mutex* ProfilePrint_lock = NULL; Mutex* ExceptionCache_lock = NULL; Mutex* NMethodSweeperStats_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* FreeList_lock = NULL; Mutex* OldSets_lock = NULL; Monitor* RootRegionScan_lock = NULL; Mutex* Management_lock = NULL; Monitor* Service_lock = NULL; Monitor* Notification_lock = NULL; Monitor* PeriodicTask_lock = NULL; Monitor* RedefineClasses_lock = NULL; Mutex* Verify_lock = NULL; Monitor* Zip_lock = NULL; #if INCLUDE_JFR Mutex* JfrStacktrace_lock = NULL; Monitor* JfrMsg_lock = NULL; Mutex* JfrBuffer_lock = NULL; Mutex* JfrStream_lock = NULL; Monitor* JfrThreadSampler_lock = NULL; #endif #ifndef SUPPORTS_NATIVE_CX8 Mutex* UnsafeJlong_lock = NULL; #endif Mutex* CodeHeapStateAnalytics_lock = NULL; Mutex* MetaspaceExpand_lock = NULL; Mutex* ClassLoaderDataGraph_lock = NULL; Monitor* ThreadsSMRDelete_lock = NULL; Mutex* ThreadIdTableCreate_lock = NULL; Mutex* SharedDecoder_lock = NULL; Mutex* DCmdFactory_lock = NULL; #if INCLUDE_NMT Mutex* NMTQuery_lock = NULL; #endif #if INCLUDE_CDS #if INCLUDE_JVMTI Mutex* CDSClassFileStream_lock = NULL; #endif Mutex* DumpTimeTable_lock = NULL; Mutex* CDSLambda_lock = NULL; #endif // INCLUDE_CDS #if INCLUDE_JVMCI Monitor* JVMCI_lock = NULL; #endif #define MAX_NUM_MUTEX 128 static Mutex* _mutex_array[MAX_NUM_MUTEX]; static int _num_mutex; #ifdef ASSERT void assert_locked_or_safepoint(const Mutex* lock) { // check if this thread owns the lock (common case) 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("must own lock %s", lock->name()); } // a weaker assertion than the above void assert_locked_or_safepoint_weak(const Mutex* lock) { assert(lock != NULL, "Need non-NULL lock"); if (lock->is_locked()) return; if (SafepointSynchronize::is_at_safepoint()) return; if (!Universe::is_fully_initialized()) return; fatal("must own lock %s", lock->name()); } // a stronger assertion than the above void assert_lock_strong(const Mutex* lock) { assert(lock != NULL, "Need non-NULL lock"); if (lock->owned_by_self()) return; fatal("must own lock %s", lock->name()); } void assert_locked_or_safepoint_or_handshake(const Mutex* lock, const JavaThread* thread) { if (Thread::current() == thread->active_handshaker()) return; assert_locked_or_safepoint(lock); } #endif #define def(var, type, pri, vm_block, safepoint_check_allowed ) { \ var = new type(Mutex::pri, #var, vm_block, Mutex::safepoint_check_allowed); \ assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \ _mutex_array[_num_mutex++] = var; \ } // Using Padded subclasses to prevent false sharing of these global monitors and mutexes. void mutex_init() { def(tty_lock , PaddedMutex , tty, true, _safepoint_check_never); // allow to lock in VM def(CGC_lock , PaddedMonitor, special, true, _safepoint_check_never); // coordinate between fore- and background GC def(STS_lock , PaddedMonitor, leaf, true, _safepoint_check_never); def(FullGCCount_lock , PaddedMonitor, leaf, true, _safepoint_check_never); // in support of ExplicitGCInvokesConcurrent if (UseG1GC) { def(G1OldGCCount_lock , PaddedMonitor, leaf, true, _safepoint_check_always); def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, _safepoint_check_never); def(G1DetachedRefinementStats_lock, PaddedMutex, leaf , true, _safepoint_check_never); def(FreeList_lock , PaddedMutex , leaf , true, _safepoint_check_never); def(OldSets_lock , PaddedMutex , leaf , true, _safepoint_check_never); def(RootRegionScan_lock , PaddedMonitor, leaf , true, _safepoint_check_never); def(StringDedupQueue_lock , PaddedMonitor, leaf, true, _safepoint_check_never); def(StringDedupTable_lock , PaddedMutex , leaf, true, _safepoint_check_never); def(MarkStackFreeList_lock , PaddedMutex , leaf , true, _safepoint_check_never); def(MarkStackChunkList_lock , PaddedMutex , leaf , true, _safepoint_check_never); def(MonitoringSupport_lock , PaddedMutex , native , true, _safepoint_check_never); // used for serviceability monitoring support } if (UseShenandoahGC) { def(StringDedupQueue_lock , PaddedMonitor, leaf, true, _safepoint_check_never); def(StringDedupTable_lock , PaddedMutex , leaf + 1, true, _safepoint_check_never); } def(ParGCRareEvent_lock , PaddedMutex , leaf, true, _safepoint_check_always); def(CodeCache_lock , PaddedMonitor, special, true, _safepoint_check_never); def(CodeSweeper_lock , PaddedMonitor, special-2, true, _safepoint_check_never); def(RawMonitor_lock , PaddedMutex , special, true, _safepoint_check_never); def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, _safepoint_check_always); // used for oop_map_cache allocation. def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, _safepoint_check_never); def(ClassLoaderDataGraph_lock , PaddedMutex , nonleaf, false, _safepoint_check_always); def(Patching_lock , PaddedMutex , special, true, _safepoint_check_never); // used for safepointing and code patching. def(CompiledMethod_lock , PaddedMutex , special-1, true, _safepoint_check_never); def(Service_lock , PaddedMonitor, special, true, _safepoint_check_never); // used for service thread operations if (UseNotificationThread) { def(Notification_lock , PaddedMonitor, special, true, _safepoint_check_never); // used for notification thread operations } else { Notification_lock = Service_lock; } def(JmethodIdCreation_lock , PaddedMutex , leaf, true, _safepoint_check_never); // used for creating jmethodIDs. def(SystemDictionary_lock , PaddedMonitor, leaf, true, _safepoint_check_always); def(ProtectionDomainSet_lock , PaddedMutex , leaf-1, true, _safepoint_check_never); def(SharedDictionary_lock , PaddedMutex , leaf, true, _safepoint_check_always); def(Module_lock , PaddedMutex , leaf+2, false, _safepoint_check_always); def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, _safepoint_check_never); def(VMStatistic_lock , PaddedMutex , leaf, false, _safepoint_check_always); def(ExpandHeap_lock , PaddedMutex , leaf, true, _safepoint_check_always); // Used during compilation by VM thread def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf-1, true, _safepoint_check_never); // handles are used by VM thread def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, _safepoint_check_always); def(SymbolArena_lock , PaddedMutex , leaf+2, true, _safepoint_check_never); def(ProfilePrint_lock , PaddedMutex , leaf, false, _safepoint_check_always); // serial profile printing def(ExceptionCache_lock , PaddedMutex , leaf, false, _safepoint_check_always); // serial profile printing def(Debug1_lock , PaddedMutex , leaf, true, _safepoint_check_never); #ifndef PRODUCT def(FullGCALot_lock , PaddedMutex , leaf, false, _safepoint_check_always); // a lock to make FullGCALot MT safe #endif def(BeforeExit_lock , PaddedMonitor, leaf, true, _safepoint_check_always); def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, _safepoint_check_always); // used for allocating PerfData memory for performance data def(PerfDataManager_lock , PaddedMutex , leaf, true, _safepoint_check_always); // used for synchronized access to PerfDataManager resources def(Threads_lock , PaddedMonitor, barrier, true, _safepoint_check_always); // Used for safepoint protocol. def(NonJavaThreadsList_lock , PaddedMutex, barrier, true, _safepoint_check_never); def(NonJavaThreadsListSync_lock , PaddedMutex, leaf, true, _safepoint_check_never); def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, _safepoint_check_never); // VM_thread allowed to block on these def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always); def(RetData_lock , PaddedMutex , nonleaf, false, _safepoint_check_always); def(Terminator_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always); def(InitCompleted_lock , PaddedMonitor, leaf, true, _safepoint_check_never); def(VtableStubs_lock , PaddedMutex , nonleaf, true, _safepoint_check_never); def(Notify_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always); def(JNICritical_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always); // used for JNI critical regions def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, _safepoint_check_always); def(Heap_lock , PaddedMonitor, nonleaf+1, false, _safepoint_check_sometimes); // Doesn't safepoint check during termination. def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, _safepoint_check_always); // jfieldID, Used in VM_Operation def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_never); // locks VtableStubs_lock, InlineCacheBuffer_lock def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, _safepoint_check_always); def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_always); def(DirectivesStack_lock , PaddedMutex , special, true, _safepoint_check_never); def(MultiArray_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_always); def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController def(Management_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_always); // used for JVM management def(ConcurrentGCBreakpoints_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always); def(Compile_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always); def(MethodData_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always); def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always); def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, false, _safepoint_check_always); def(Debug2_lock , PaddedMutex , nonleaf+4, true, _safepoint_check_never); def(Debug3_lock , PaddedMutex , nonleaf+4, true, _safepoint_check_never); def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, _safepoint_check_always); def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, _safepoint_check_always); def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, _safepoint_check_always); def(Verify_lock , PaddedMutex, nonleaf+5, true, _safepoint_check_always); def(Zip_lock , PaddedMonitor, leaf, true, _safepoint_check_never); if (WhiteBoxAPI) { def(Compilation_lock , PaddedMonitor, leaf, false, _safepoint_check_never); } #if INCLUDE_JFR def(JfrMsg_lock , PaddedMonitor, leaf, true, _safepoint_check_always); def(JfrBuffer_lock , PaddedMutex , leaf, true, _safepoint_check_never); def(JfrStream_lock , PaddedMutex , nonleaf + 1, false, _safepoint_check_never); def(JfrStacktrace_lock , PaddedMutex , special, true, _safepoint_check_never); def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, _safepoint_check_never); #endif #ifndef SUPPORTS_NATIVE_CX8 def(UnsafeJlong_lock , PaddedMutex , special, false, _safepoint_check_never); #endif def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, _safepoint_check_never); def(NMethodSweeperStats_lock , PaddedMutex , special, true, _safepoint_check_never); def(ThreadsSMRDelete_lock , PaddedMonitor, special, true, _safepoint_check_never); def(ThreadIdTableCreate_lock , PaddedMutex , leaf, false, _safepoint_check_always); def(SharedDecoder_lock , PaddedMutex , native, true, _safepoint_check_never); def(DCmdFactory_lock , PaddedMutex , leaf, true, _safepoint_check_never); #if INCLUDE_NMT def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, _safepoint_check_always); #endif #if INCLUDE_CDS #if INCLUDE_JVMTI def(CDSClassFileStream_lock , PaddedMutex , max_nonleaf, false, _safepoint_check_always); #endif def(DumpTimeTable_lock , PaddedMutex , leaf - 1, true, _safepoint_check_never); def(CDSLambda_lock , PaddedMutex , leaf, true, _safepoint_check_never); #endif // INCLUDE_CDS #if INCLUDE_JVMCI def(JVMCI_lock , PaddedMonitor, nonleaf+2, true, _safepoint_check_always); #endif } GCMutexLocker::GCMutexLocker(Mutex* 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"); }