Efficient stand-in for a mutual exclusion lock when synchronization is either unnecessary or not important. More...

#include <rw/sync/RWNullMutexLock.h>

Inheritance diagram for RWNullMutexLock:

Public Types
typedef RWTLockGuard< RWNullMutexLock >	LockGuard

typedef RWTReadLockGuard< RWNullMutexLock >	ReadLockGuard

typedef RWTReadUnlockGuard< RWNullMutexLock >	ReadUnlockGuard

typedef RWTTryLockGuard< RWNullMutexLock >	TryLockGuard

typedef RWTTryReadLockGuard< RWNullMutexLock >	TryReadLockGuard

typedef RWTTryWriteLockGuard< RWNullMutexLock >	TryWriteLockGuard

typedef RWTUnlockGuard< RWNullMutexLock >	UnlockGuard

typedef RWTWriteLockGuard< RWNullMutexLock >	WriteLockGuard

typedef RWTWriteUnlockGuard< RWNullMutexLock >	WriteUnlockGuard

Public Member Functions
	RWNullMutexLock (RWStaticCtor)

	RWNullMutexLock (RWCancellationState state=0)

	~RWNullMutexLock ()

void	acquire ()

RWWaitStatus	acquire (unsigned long milliseconds)

void	acquireRead ()

RWWaitStatus	acquireRead (unsigned long milliseconds)

void	acquireWrite ()

RWWaitStatus	acquireWrite (unsigned long milliseconds)

bool	isAcquired () const

void	release ()

bool	tryAcquire ()

bool	tryAcquireRead ()

bool	tryAcquireWrite ()

Public Member Functions inherited from RWSynchObject
void	disableCancellation ()

void	enableCancellation (RWCancellationState)

bool	isCancellationEnabled () const

void	setCancellation (RWCancellationState)

Private Member Functions
	RWNullMutexLock (const RWNullMutexLock &second)

RWNullMutexLock &	operator= (const RWNullMutexLock &second)

Additional Inherited Members
Protected Member Functions inherited from RWSynchObject
	RWSynchObject (RWCancellationState state=0)

	RWSynchObject (RWStaticCtor)

	RWSynchObject (const RWSynchObject &second)

RWSynchObject &	operator= (const RWSynchObject &second)

void	testCancellation ()

Related Functions inherited from RWSynchObject
#define	RW_CANCELLATION_DISABLED

#define	RW_CANCELLATION_ENABLED

typedef void(*	RWCancellationState) ()

void	rwServiceCancellation (void)

Detailed Description

An RWNullMutexLock is an efficient stand-in for a mutual exclusion lock, particularly when you know that critical sections of code do not need synchronization. For example, you may know that it is not possible for more than one thread to simultaneously enter a section of code that would otherwise require locking. In such cases, you can use an RWNullMutexLock to eliminate the unnecessary overhead of acquiring and releasing a mutex. This class can also be used to instantiate a single-threaded or non-thread-safe version of the template classes that accept a mutex parameter, such as RWTMonitor.

Example: #include <rw/sync/RWMutexLock.h>

#include <rw/sync/RWNullMutexLock.h>

int main()

{

RWNullMutexLock mutex;

mutex.acquire(); // No cost if synchronization not required

// critical section

mutex.release();

// Same thing, this time using a guard:

{

RWNullMutexLock::Lockguard lock(mutex); // does nothing if

// synchronization not

// required critical section

// If synchronization required, lock will be released

// automatically

}

}

See also: RWMutexLock, RWTLockGuard, RWTUnlockGuard, RWTTryLockGuard