/*
* Copyright (c) 1997, 2014, 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 dictionary
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* HotCardCache_lock; // protects the hot card cache
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
#ifdef INCLUDE_TRACE
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
#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 to be used for verify code, where we can relax out dead-lock
// detection 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. disable 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