The QWriteLocker class is a convenience class that simplifies locking and unlocking read-write locks for write access. More...
#include <QWriteLocker>Note: All functions in this class are thread-safe.
| QWriteLocker ( QReadWriteLock * lock ) | |
| ~QWriteLocker () | |
| QReadWriteLock * | readWriteLock () const |
| void | relock () |
| void | unlock () |
The QWriteLocker class is a convenience class that simplifies locking and unlocking read-write locks for write access.
The purpose of QWriteLocker (and QReadLocker is to simplify QReadWriteLock 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 uses QWriteLocker to lock and unlock a read-write lock for writing:
QReadWriteLock lock;
void writeData(const QByteArray &data)
{
QWriteLocker locker(&lock);
...
}
It is equivalent to the following code:
QReadWriteLock lock;
void writeData(const QByteArray &data)
{
lock.lockForWrite();
...
lock.unlock();
}
The QMutexLocker documentation shows examples where the use of a locker object greatly simplifies programming.
See also QReadLocker and QReadWriteLock.
Constructs a QWriteLocker and locks lock for writing. The lock will be unlocked when the QWriteLocker is destroyed. If lock is zero, QWriteLocker does nothing.
See also QReadWriteLock::lockForWrite().
Destroys the QWriteLocker and unlocks the lock that was passed to the constructor.
See also QReadWriteLock::unlock().
Returns a pointer to the read-write lock that was passed to the constructor.
Relocks an unlocked lock.
See also unlock().
Unlocks the lock associated with this locker.
See also QReadWriteLock::unlock().