Struct qt_core::QReadLocker
source · #[repr(C)]pub struct QReadLocker { /* private fields */ }
Expand description
The QReadLocker class is a convenience class that simplifies locking and unlocking read-write locks for read access.
C++ class: QReadLocker
.
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.
Implementations§
source§impl QReadLocker
impl QReadLocker
sourcepub unsafe fn new(
read_write_lock: impl CastInto<Ptr<QReadWriteLock>>
) -> CppBox<QReadLocker>
pub unsafe fn new( read_write_lock: impl CastInto<Ptr<QReadWriteLock>> ) -> CppBox<QReadLocker>
Constructs a QReadLocker and locks lock for reading. The lock will be unlocked when the QReadLocker is destroyed. If lock
is zero, QReadLocker does nothing.
Calls C++ function: [constructor] void QReadLocker::QReadLocker(QReadWriteLock* readWriteLock)
.
Constructs a QReadLocker and locks lock for reading. The lock will be unlocked when the QReadLocker is destroyed. If lock
is zero, QReadLocker does nothing.
See also QReadWriteLock::lockForRead().
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* QReadLocker::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 QReadLocker::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 QReadLocker::unlock()
.
Unlocks the lock associated with this locker.
See also QReadWriteLock::unlock().
Trait Implementations§
source§impl CppDeletable for QReadLocker
impl CppDeletable for QReadLocker
source§unsafe fn delete(&self)
unsafe fn delete(&self)
Destroys the QReadLocker and unlocks the lock that was passed to the constructor.
Calls C++ function: [destructor] void QReadLocker::~QReadLocker()
.
Destroys the QReadLocker and unlocks the lock that was passed to the constructor.
See also QReadWriteLock::unlock().