QGIS API Documentation 3.41.0-Master (181b2f43d8e)
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The QgsReadWriteLocker class is a convenience class that simplifies locking and unlocking QReadWriteLocks. More...
#include <qgsreadwritelocker.h>
Public Types | |
enum | Mode { Read , Write , Unlocked } |
A QReadWriteLock can be in 3 different modes, read, write or unlocked. More... | |
Public Member Functions | |
QgsReadWriteLocker (QReadWriteLock &lock, Mode mode) | |
Create a new QgsReadWriteLocker for lock and initialize in mode. | |
~QgsReadWriteLocker () | |
void | changeMode (Mode mode) |
Change the mode of the lock to mode. | |
void | unlock () |
Unlocks the lock. | |
The QgsReadWriteLocker class is a convenience class that simplifies locking and unlocking QReadWriteLocks.
Locking and unlocking a QReadWriteLocks in complex functions and statements or in exception handling code is error-prone and difficult to debug. QgsReadWriteLocker can be used in such situations to ensure that the state of the lock is always well-defined.
QgsReadWriteLocker should be created within a function where a QReadWriteLock needs to be locked. The lock may be locked when QgsReadWriteLocker is created or when changeMode is called. You can unlock and relock the lock with unlock() and changeMode(). If locked, the lock will be unlocked when the QgsReadWriteLocker is destroyed.
Definition at line 40 of file qgsreadwritelocker.h.
A QReadWriteLock can be in 3 different modes, read, write or unlocked.
Enumerator | |
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Read | Lock for read. |
Write | Lock for write. |
Unlocked | Unlocked. |
Definition at line 47 of file qgsreadwritelocker.h.
QgsReadWriteLocker::QgsReadWriteLocker | ( | QReadWriteLock & | lock, |
QgsReadWriteLocker::Mode | mode | ||
) |
Create a new QgsReadWriteLocker for lock and initialize in mode.
Definition at line 20 of file qgsreadwritelocker.cpp.
QgsReadWriteLocker::~QgsReadWriteLocker | ( | ) |
Definition at line 53 of file qgsreadwritelocker.cpp.
void QgsReadWriteLocker::changeMode | ( | QgsReadWriteLocker::Mode | mode | ) |
Change the mode of the lock to mode.
The lock will be unlocked and relocked as required.
Definition at line 30 of file qgsreadwritelocker.cpp.
void QgsReadWriteLocker::unlock | ( | ) |
Unlocks the lock.
Equivalent to doing changeMode( QgsReadWriteLocker::Unlock );
Definition at line 45 of file qgsreadwritelocker.cpp.