QReadLocker Class Reference

Detailed Description

The QReadLocker class is a convenience class that simplifies locking and unlocking read-write locks for read access.

The purpose of QReadLocker (and QWriteLocker) is to simplify QReadWriteLock locking and unlocking. Locking and unlocking statements or in exception handling code is error-prone and difficult to debug. QReadLocker can be used in such situations to ensure that the state of the lock is always well-defined.

Here's an example that uses QReadLocker to lock and unlock a read-write lock for reading:

 QReadWriteLock lock;

 QByteArray readData()
 {
     QReadLocker locker(&lock);
     ...
     return data;
 }

It is equivalent to the following code:

 QReadWriteLock lock;

 QByteArray readData()
 {
     lock.lockForRead();
     ...
     lock.unlock();
     return data;
 }

The QMutexLocker documentation shows examples where the use of a locker object greatly simplifies programming.