/* * Copyright (c) 1997, 2015, 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. * */ #ifndef SHARE_VM_RUNTIME_MUTEXLOCKER_HPP #define SHARE_VM_RUNTIME_MUTEXLOCKER_HPP #include "memory/allocation.hpp" #include "runtime/mutex.hpp" #ifdef TARGET_OS_FAMILY_linux # include "os_linux.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_solaris # include "os_solaris.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_windows # include "os_windows.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_aix # include "os_aix.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_bsd # include "os_bsd.inline.hpp" #endif // Mutexes used in the VM. extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code extern Monitor* SystemDictionary_lock; // a lock on the system dictonary extern Mutex* PackageTable_lock; // a lock on the class loader package table extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment extern Mutex* JNIGlobalHandle_lock; // a lock on creating JNI global handles extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list extern Mutex* MemberNameTable_lock; // a lock on the MemberNameTable updates extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data extern Monitor* JvmtiPendingEvent_lock; // a lock on the JVMTI pending events list extern Monitor* Heap_lock; // a lock on the heap extern Mutex* ExpandHeap_lock; // a lock on expanding the heap extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary extern Mutex* VtableStubs_lock; // a lock on the VtableStubs extern Mutex* SymbolTable_lock; // a lock on the symbol table extern Mutex* StringTable_lock; // a lock on the interned string table extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table extern Mutex* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx extern Mutex* MethodData_lock; // a lock on installation of method data extern Mutex* RetData_lock; // a lock on installation of RetData inside method data extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads // (also used by Safepoints too to block threads creation/destruction) extern Monitor* CGC_lock; // used for coordination between // fore- & background GC threads. extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. extern Monitor* SLT_lock; // used in CMS GC for acquiring PLL extern Monitor* iCMS_lock; // CMS incremental mode start/stop notification extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc extern Monitor* CMark_lock; // used for concurrent mark thread coordination extern Mutex* CMRegionStack_lock; // used for protecting accesses to the CM region stack extern Mutex* SATB_Q_FL_lock; // Protects SATB Q // buffer free list. extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q // completed buffer queue. extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB // queue shared by // non-Java threads. extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q // buffer free list. extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q // completed buffer queue. extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card // queue shared by // non-Java threads. // (see option ExplicitGCInvokesConcurrent) extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. extern Mutex* EvacFailureStack_lock; // guards the evac failure scan stack extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays extern Monitor* Terminator_lock; // a lock used to guard termination of the vm extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm extern Monitor* Interrupt_lock; // a lock used for condition variable mediated interrupt processing extern Monitor* ProfileVM_lock; // a lock used for profiling the VMThread extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues #ifndef PRODUCT extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe #endif // PRODUCT extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing extern Mutex* Debug2_lock; // down synchronization related bugs! extern Mutex* Debug3_lock; extern Mutex* RawMonitor_lock; extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources extern Mutex* ParkerFreeList_lock; extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches extern Mutex* FreeList_lock; // protects the free region list during safepoints extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list extern Mutex* OldSets_lock; // protects the old region sets extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions extern Mutex* MMUTracker_lock; // protects the MMU // tracker data structures extern Mutex* Management_lock; // a lock used to serialize JVM management extern Monitor* Service_lock; // a lock used for service thread operation extern Monitor* PeriodicTask_lock; // protects the periodic task structure #if INCLUDE_JFR extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table extern Monitor* JfrMsg_lock; // protects JFR messaging extern Mutex* JfrBuffer_lock; // protects JFR buffer operations extern Mutex* JfrStream_lock; // protects JFR stream access extern Mutex* JfrThreadGroups_lock; // protects JFR access to Thread Groups #ifndef SUPPORTS_NATIVE_CX8 extern Mutex* JfrCounters_lock; // provides atomic updates of JFR counters #endif #endif #ifndef SUPPORTS_NATIVE_CX8 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 #endif // A MutexLocker provides mutual exclusion with respect to a given mutex // for the scope which contains the locker. The lock is an OS lock, not // an object lock, and the two do not interoperate. Do not use Mutex-based // locks to lock on Java objects, because they will not be respected if a // that object is locked using the Java locking mechanism. // // NOTE WELL!! // // See orderAccess.hpp. We assume throughout the VM that MutexLocker's // and friends constructors do a fence, a lock and an acquire *in that // order*. And that their destructors do a release and unlock, in *that* // order. If their implementations change such that these assumptions // are violated, a whole lot of code will break. // Print all mutexes/monitors that are currently owned by a thread; called // by fatal error handler. void print_owned_locks_on_error(outputStream* st); char *lock_name(Mutex *mutex); class MutexLocker: StackObj { private: Monitor * _mutex; public: MutexLocker(Monitor * mutex) { assert(mutex->rank() != Mutex::special, "Special ranked mutex should only use MutexLockerEx"); _mutex = mutex; _mutex->lock(); } // Overloaded constructor passing current thread MutexLocker(Monitor * mutex, Thread *thread) { assert(mutex->rank() != Mutex::special, "Special ranked mutex should only use MutexLockerEx"); _mutex = mutex; _mutex->lock(thread); } ~MutexLocker() { _mutex->unlock(); } }; // for debugging: check that we're already owning this lock (or are at a safepoint) #ifdef ASSERT void assert_locked_or_safepoint(const Monitor * lock); void assert_lock_strong(const Monitor * lock); #else #define assert_locked_or_safepoint(lock) #define assert_lock_strong(lock) #endif // A MutexLockerEx behaves like a MutexLocker when its constructor is // called with a Mutex. Unlike a MutexLocker, its constructor can also be // called with NULL, in which case the MutexLockerEx is a no-op. There // is also a corresponding MutexUnlockerEx. We want to keep the // basic MutexLocker as fast as possible. MutexLockerEx can also lock // without safepoint check. class MutexLockerEx: public StackObj { private: Monitor * _mutex; public: MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { _mutex = mutex; if (_mutex != NULL) { assert(mutex->rank() > Mutex::special || no_safepoint_check, "Mutexes with rank special or lower should not do safepoint checks"); if (no_safepoint_check) _mutex->lock_without_safepoint_check(); else _mutex->lock(); } } ~MutexLockerEx() { if (_mutex != NULL) { _mutex->unlock(); } } }; // A MonitorLockerEx is like a MutexLockerEx above, except it takes // a possibly null Monitor, and allows wait/notify as well which are // delegated to the underlying Monitor. class MonitorLockerEx: public MutexLockerEx { private: Monitor * _monitor; public: MonitorLockerEx(Monitor* monitor, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): MutexLockerEx(monitor, no_safepoint_check), _monitor(monitor) { // Superclass constructor did locking } ~MonitorLockerEx() { #ifdef ASSERT if (_monitor != NULL) { assert_lock_strong(_monitor); } #endif // ASSERT // Superclass destructor will do unlocking } bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, long timeout = 0, bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { if (_monitor != NULL) { return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); } return false; } bool notify_all() { if (_monitor != NULL) { return _monitor->notify_all(); } return true; } bool notify() { if (_monitor != NULL) { return _monitor->notify(); } return true; } }; // A GCMutexLocker is usually initialized with a mutex that is // automatically acquired in order to do GC. The function that // synchronizes using a GCMutexLocker may be called both during and between // GC's. Thus, it must acquire the mutex if GC is not in progress, but not // if GC is in progress (since the mutex is already held on its behalf.) class GCMutexLocker: public StackObj { private: Monitor * _mutex; bool _locked; public: GCMutexLocker(Monitor * mutex); ~GCMutexLocker() { if (_locked) _mutex->unlock(); } }; // A MutexUnlocker temporarily exits a previously // entered mutex for the scope which contains the unlocker. class MutexUnlocker: StackObj { private: Monitor * _mutex; public: MutexUnlocker(Monitor * mutex) { _mutex = mutex; _mutex->unlock(); } ~MutexUnlocker() { _mutex->lock(); } }; // A MutexUnlockerEx temporarily exits a previously // entered mutex for the scope which contains the unlocker. class MutexUnlockerEx: StackObj { private: Monitor * _mutex; bool _no_safepoint_check; public: MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { _mutex = mutex; _no_safepoint_check = no_safepoint_check; _mutex->unlock(); } ~MutexUnlockerEx() { if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { _mutex->lock_without_safepoint_check(); } else { _mutex->lock(); } } }; #ifndef PRODUCT // // A special MutexLocker that allows: // - reentrant locking // - locking out of order // // Only too be used for verify code, where we can relaxe out dead-lock // dection code a bit (unsafe, but probably ok). This code is NEVER to // be included in a product version. // class VerifyMutexLocker: StackObj { private: Monitor * _mutex; bool _reentrant; public: VerifyMutexLocker(Monitor * mutex) { _mutex = mutex; _reentrant = mutex->owned_by_self(); if (!_reentrant) { // We temp. diable strict safepoint checking, while we require the lock FlagSetting fs(StrictSafepointChecks, false); _mutex->lock(); } } ~VerifyMutexLocker() { if (!_reentrant) { _mutex->unlock(); } } }; #endif #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP