Contents

• Public Functions
• Detailed Description

Detailed Description

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

The purpose ofQReadLocker (andQWriteLocker) is to simplifyQReadWriteLock 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 usesQReadLocker 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;}

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

Member Function Documentation

QReadLocker::QReadLocker(QReadWriteLock * lock)

Constructs aQReadLocker and lockslock for reading. The lock will be unlocked when theQReadLocker is destroyed. Iflock is zero,QReadLocker does nothing.

See alsoQReadWriteLock::lockForRead().

QReadLocker::~QReadLocker()

Destroys theQReadLocker and unlocks the lock that was passed to the constructor.

See alsoQReadWriteLock::unlock().

QReadWriteLock * QReadLocker::readWriteLock() const

Returns a pointer to the read-write lock that was passed to the constructor.

void QReadLocker::relock()

Relocks an unlocked lock.

See alsounlock().

void QReadLocker::unlock()

Unlocks the lock associated with this locker.

See alsoQReadWriteLock::unlock().