Struct qt_core::QWriteLocker
source · #[repr(C)]pub struct QWriteLocker { /* private fields */ }
Expand description
The QWriteLocker class is a convenience class that simplifies locking and unlocking read-write locks for write access.
C++ class: QWriteLocker
.
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.
Implementations§
source§impl QWriteLocker
impl QWriteLocker
sourcepub unsafe fn new(
read_write_lock: impl CastInto<Ptr<QReadWriteLock>>
) -> CppBox<QWriteLocker>
pub unsafe fn new( read_write_lock: impl CastInto<Ptr<QReadWriteLock>> ) -> CppBox<QWriteLocker>
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.
Calls C++ function: [constructor] void QWriteLocker::QWriteLocker(QReadWriteLock* readWriteLock)
.
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().
sourcepub unsafe fn read_write_lock(&self) -> Ptr<QReadWriteLock>
pub unsafe fn read_write_lock(&self) -> Ptr<QReadWriteLock>
Returns a pointer to the read-write lock that was passed to the constructor.
Calls C++ function: QReadWriteLock* QWriteLocker::readWriteLock() const
.
Returns a pointer to the read-write lock that was passed to the constructor.
sourcepub unsafe fn relock(&self)
pub unsafe fn relock(&self)
Relocks an unlocked lock.
Calls C++ function: void QWriteLocker::relock()
.
Relocks an unlocked lock.
See also unlock().
sourcepub unsafe fn unlock(&self)
pub unsafe fn unlock(&self)
Unlocks the lock associated with this locker.
Calls C++ function: void QWriteLocker::unlock()
.
Unlocks the lock associated with this locker.
See also QReadWriteLock::unlock().
Trait Implementations§
source§impl CppDeletable for QWriteLocker
impl CppDeletable for QWriteLocker
source§unsafe fn delete(&self)
unsafe fn delete(&self)
Destroys the QWriteLocker and unlocks the lock that was passed to the constructor.
Calls C++ function: [destructor] void QWriteLocker::~QWriteLocker()
.
Destroys the QWriteLocker and unlocks the lock that was passed to the constructor.
See also QReadWriteLock::unlock().