Using a Lock Guard

SourcePro Core : Threads Module User's Guide : PART II Concurrency Packages : The Synchronization Package : The Guard Classes : Using a Lock Guard

Using a Lock Guard

To use a lock guard, declare a named instance of the guard class and initialize it with a reference to the synchronization mechanism, as shown in Example 39.

Example 39 – Using a lock guard

RWMutexLock mutex;

{

RWTLockGuard<RWMutexLock> lock(mutex); // 1

// Mutex is acquired!

} // 2

// Mutex is released!

//1 The declaration of an RWTLockGuard<RWMutexLock> instance invokes a constructor that acquires the mutex passed as an argument.

//2 The RWTLockGuard<RWMutexLock> instance is automatically destroyed when it goes out-of-scope—upon exit from the block where it was declared. The RWTLockGuard<RWMutexLock> destructor releases the mutex that was previously acquired. The guard instance is also destroyed if an exception occurs within this block, thus insuring that the mutex is always released.