QReadLocker Class Reference [QtCore module]The QReadLocker class is a convenience class that simplifies locking and unlocking read-write locks for read access. More...
MethodsSpecial Methods
Detailed DescriptionThe 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()
{
locker.lockForRead();
...
locker.unlock();
return data;
}
The QMutexLocker documentation shows examples where the use of a locker object greatly simplifies programming.
See also QWriteLocker and QReadWriteLock.
Method DocumentationQReadLocker.__init__ (self, QReadWriteLock areadWriteLock)Constructs a QReadLocker and locks lock for reading. The lock will be unlocked when the QReadLocker is destroyed. If lock is zero, QReadLocker does nothing.
See also QReadWriteLock.lockForRead().
QReadWriteLock QReadLocker.readWriteLock (self)Returns a pointer to the read-write lock that was passed to the constructor.
QReadLocker.relock (self)Relocks an unlocked lock.
See also unlock().
QReadLocker.unlock (self)Unlocks the lock associated with this locker.
See also QReadWriteLock.unlock().
object QReadLocker.__enter__ (self)QReadLocker.__exit__ (self, object type, object value, object traceback)
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