RAII手法封装互斥锁

RAII手法是 Resource Acquisition is Initialization 的缩写，意为“资源获取即初始化”，在使用智能指针时也使用，下面是针对互斥量时的实现，

#include <iostream>
#include <pthread.h>

using namespace std;

class MutexLock
{
public:
    MutexLock()
    {
        pthread_mutex_init(&mutex_, NULL);
    }

    ~MutexLock()
    {
        pthread_mutex_destroy(&mutex_);
    }

    void Lock()
    {
        pthread_mutex_lock(&mutex_);
    }

    void Unlock()
    {
        pthread_mutex_unlock(&mutex_);
    }

private:
    MutexLock(const MutexLock&);
    MutexLock& operator=(const MutexLock&);
    pthread_mutex_t mutex_;
};

class MutexLockGuard
{
public:
    explicit MutexLockGuard(MutexLock& mutex): mutex_(mutex)
    {
        mutex_.Lock();
    }

    ~MutexLockGuard()
    {
        mutex_.Unlock();
    }

private:
    MutexLockGuard(const MutexLockGuard&);
    MutexLockGuard& operator=(const MutexLockGuard&);

    MutexLock& mutex_;
};

class Foo
{
public:
    void print()
    {
        MutexLockGuard lock(mutex_);
        cout << "Hello" << endl;
    }

private:
    MutexLock mutex_;    
};