Struct qt_core::QWriteLocker

#[repr(C)]pub struct QWriteLocker { /* fields omitted */ }

The QWriteLocker class is a convenience class that simplifies locking and unlocking read-write locks for write access.

C++ class: QWriteLocker.

C++ documentation:

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.

Methods

impl 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).

C++ documentation:

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().

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.

C++ documentation:

Returns a pointer to the read-write lock that was passed to the constructor.

pub unsafe fn relock(&self)

Relocks an unlocked lock.

Calls C++ function: void QWriteLocker::relock().

C++ documentation:

Relocks an unlocked lock.

See also unlock().

pub unsafe fn unlock(&self)

Unlocks the lock associated with this locker.

Calls C++ function: void QWriteLocker::unlock().

C++ documentation:

Unlocks the lock associated with this locker.

See also QReadWriteLock::unlock().

Trait Implementations

impl CppDeletable for QWriteLocker

unsafe fn delete(&self)

Destroys the QWriteLocker and unlocks the lock that was passed to the constructor.

Calls C++ function: [destructor] void QWriteLocker::~QWriteLocker().

C++ documentation:

Destroys the QWriteLocker and unlocks the lock that was passed to the constructor.

See also QReadWriteLock::unlock().