线程同步机制的封装

#ifndef LOCKER_H
#define LOCKER_H

#include <pthread.h>
#include <semaphore.h>
#include <exception>

// 封装信号量
class sem {
public:
    sem()
    {
        if (sem_init(&m_sem, 0, 0) != 0) {
            throw std::exception();
        }
    }
    ~sem()
    {
        sem_destroy(&m_sem);
    }
    bool wait()
    {
        return sem_wait(&m_sem) == 0;
    }
    bool post()
    {
        return sem_post(&m_sem) == 0;
    }
private:
    sem_t m_sem;
};

// 封装互斥锁
class locker {
public:
    locker()
    {
        if (pthread_mutex_init(&m_mutex, nullptr) != 0) {
            throw std::exception();
        }
    }
    ~locker()
    {
        pthread_mutex_destroy(&m_mutex);
    }
    bool lock()
    {
        return pthread_mutex_lock(&m_mutex) == 0;
    }
    bool unlock()
    {
        return pthread_mutex_unlock(&m_mutex) == 0;
    }
private:
    pthread_mutex_t m_mutex;
};

// 封装条件变量
class cond {
public:
    cond()
    {
        if (pthread_mutex_init(&m_mutex, nullptr) != 0) {
            throw std::exception();
        }
        if (pthread_cond_init(&m_cond, nullptr) != 0) {
            pthread_mutex_destroy(&m_mutex); // 构造函数出问题，立即释放已成功分配的资源
            throw std::exception();
        }
    }
    ~cond()
    {
        pthread_mutex_destroy(&m_mutex);
        pthread_cond_destroy(&m_cond);
    }
    bool wait()
    {
        int ret = 0;
        pthread_mutex_lock(&m_mutex);
        ret = pthread_cond_wait(&m_cond, &m_mutex);
        pthread_mutex_unlock(&m_mutex);
        return ret == 0;
    }
    bool signal()
    {
        return pthread_cond_signal(&m_cond) == 0;
    }
private:
    pthread_cond_t m_cond;
    pthread_mutex_t m_mutex;
};

#endif