Contents

• Public Functions
• Detailed Description

Detailed Description

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

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

Here's an example that usesQWriteLocker to lock and unlock a read-write lock for writing:

QReadWriteLock lock;void writeData(constQByteArray&data){QWriteLocker locker(&lock);...}

It is equivalent to the following code:

QReadWriteLock lock;void writeData(constQByteArray&data){    lock.lockForWrite();...    lock.unlock();}

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

Member Function Documentation

QWriteLocker::QWriteLocker(QReadWriteLock * lock)

Constructs aQWriteLocker and lockslock for writing. The lock will be unlocked when theQWriteLocker is destroyed. Iflock is zero,QWriteLocker does nothing.

See alsoQReadWriteLock::lockForWrite().

QWriteLocker::~QWriteLocker()

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

See alsoQReadWriteLock::unlock().

QReadWriteLock * QWriteLocker::readWriteLock() const

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

void QWriteLocker::relock()

Relocks an unlocked lock.

See alsounlock().

void QWriteLocker::unlock()

Unlocks the lock associated with this locker.

See alsoQReadWriteLock::unlock().