QReadLocker Class

QReadLocker 是便捷类, 它简化了对读写锁, 读访问的的锁定和解锁. More...

头文件:	#include <QReadLocker>
qmake:	QT += core

所有的成员列表, 包括继承的成员

Note: All functions in this class are thread-safe.

公有函数

	QReadLocker(QReadWriteLock *lock)
	~QReadLocker()
QReadWriteLock *	readWriteLock() const
void	relock()
void	unlock()

详细描述

QReadLocker (和 QWriteLocker) 的设计目的是简化 QReadWriteLock 的锁定和解锁. 锁定和解锁语句, 异常处理代码是很容易出错的, 而且很难调试. QReadLocker 可以确保在此类情况下, 锁的状态始终定义良好.

下面是一个使用 QReadLocker 锁定和解锁读写锁的示例:

 QReadWriteLock lock;

 QByteArray readData()
 {
     QReadLocker locker(&lock);
     ...
     return data;
 }

等价于以下代码:

 QReadWriteLock lock;

 QByteArray readData()
 {
     lock.lockForRead();
     ...
     lock.unlock();
     return data;
 }

QMutexLocker 文档展示了使用locker对象来大大简化编程的示例.

另见 QWriteLocker 和 QReadWriteLock.

Member Function Documentation

QReadLocker::QReadLocker(QReadWriteLock **lock*)

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().

QReadLocker::~QReadLocker()

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

See also QReadWriteLock::unlock().

QReadWriteLock *QReadLocker::readWriteLock() const

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

void QReadLocker::relock()

Relocks an unlocked lock.

See also unlock().

void QReadLocker::unlock()

Unlocks the lock associated with this locker.