QReadLocker Class
The QReadLocker class is a convenience class that simplifies locking and unlocking read-write locks for read access. More...
Header: | #include <QReadLocker> |
qmake: | QT += core |
Note: All functions in this class are thread-safe.
Public Functions
QReadLocker(QReadWriteLock *readWriteLock) | |
~QReadLocker() | |
QReadWriteLock * | readWriteLock() const |
void | relock() |
void | unlock() |
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.
See also QWriteLocker and QReadWriteLock.
Member Function Documentation
QReadLocker::QReadLocker(QReadWriteLock *readWriteLock)
Default constructs an instance of QReadLocker.
QReadLocker::~QReadLocker()
Destroys the instance of QReadLocker.