c++实现的一对锁的封装（挺有意思的）

在使用锁的时候，出现的最多的问题是由于忘记对锁的释放从而出现的各种死锁问题。所以经常会去检查对应的锁是否在之后的代码中得到合适的释放。前段时间学习到很巧妙的实现，即在构造函数中实现对锁的锁定，在析构函数中实现对锁的释放，这样只需要在使用锁的时候，定义一个锁，接下来即进入临界区，最后在退出对应的作用域的时候，自动调用析构函数，对应的锁自动释放， 对于一些锁的简单使用，还是比较不错的，个人觉得挺有意思的，拿出来和大家分享下。

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class ThreadRWLock
{
public:
ThreadRWLock(){
pthread_rwlockattr_t attr;
pthread_rwlockattr_init(&attr);
pthread_rwlock_init(&_rw_lock, &attr);
}
~ThreadRWLock(){
pthread_rwlock_destory(&_rw_lock);
}
int AcquireRead(void){
return pthread_rwlock_rdlock(&_rw_lock);
}
int AcquireWrite(void){
return pthread_rwlock_wrlock(&_rw_lock);
}
int Release(void){
return pthread_rwlock_unlock(&_rw_lock);
}
private:
pthread_rwlock_t _rw_lock;
};

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//读锁的实现

class ReadLocker
{
public:
explicit ReadLocker(ThreadRWLock& rwlock): _lock_point(&rwlock)
{
_lock_point->AcquireRead();
_is_lock = true;
}
~ReadLocker(){
if (_is_lock)
_lock_point->Release();
}
void Lock(){
if (!_is_lock)
_lock_point->AcquireRead();
_is_lock = true;
}
void Unlock(){
if (_is_lock){
_lock_point->Release();
}
_is_lock = false;
}

private:
ThreadRWLock * _lock_point;
bool is_lock;
};

//读锁的使用示例：

void fun(void){
ThreadRWLock lock;
ReadLocker readlock(lock); //自动获取读锁
/*
临界区
*/
//退出作用域自动释放读锁
}

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//写锁的实现：

class WriteLocker
{
public:
explicit WriteLocker(ThreadRWLock& rwlock)
: _lock_point(rwlock){
_lock_point->AcquireWrite();
_is_lock = true;
}
explicit WriteLocker(ThreadRWLock* rwlock)
:_lock_point(rwlock){
_lock_point->AcquireWrite();
_is_lock = true;
}
~WriteLocker(){
if(_is_lock)
_lock_point->Release();
_is_lock = false;
}
void Lock(){
if (!_is_lock)
_lock_point->AcquireWrite();
_is_lock = true;
}
void Unlock(){
if (_is_lock)
_lock_point->Release();
_is_lock = false;
}
private:
ThreadRWLock * _lock_point;
bool _is_lock;
};

//写锁的使用示例（与读锁类似）

void fun(void){
ThreadRWLock lock;
WriteLocker writelock(lock); //自动获取写锁
/*
临界区
*/
//退出作用域自动释放写锁
}

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