C++语法小记---自己实现Thread类

自己实现Thread类

• 在C++的类中，普通成员函数不能作为pthread_create的线程函数，如果要作为pthread_create中的线程函数，必须是static !

• 参考：https://blog.csdn.net/ksn13/article/details/40538083

//方式1：使用类的static函数做转换，配合this指针
class Thread
{
private:
    pthread_t id;
    
    static void * start_thread(void *arg)
    {
        Thread* thread = (Thread*)arg;
        thread->run();
    }

public:
    
    virtual void run()
    {
        cout << "success" <<endl;
    }
    
    virtual void start()
    {
        pthread_create(&id, NULL, start_thread, (void *)this);//传入this指针是关键
    }
}; 

class MyThead: public Thread
{
public:
    virtual void run()
    {
        cout << "MyThead::run()" << endl;
    }
};


int main()
{
    MyThead t;
    t.start();
    
    sleep(2);
    
    return 0;
}

//方式2：直接使用强制类型转换，因为this->xxx() 本质上等同于 xxx(this)
//方式2比当时1更安全，因为没有使用static
class Thread
{
private:
    pthread_t id;
    
    void* threadFunc(void* arg)
    {
        this->run();
    }

public:
    
    typedef void* (*FUNC)(void*);
    
    virtual void run()
    {
        cout << "success" <<endl;
    }
    
    virtual void start()
    {
        FUNC callback = (FUNC)&Thread::threadFunc;
        pthread_create(&id, NULL, callback, this); //此处传入this是必须的，且在callback中arg不可用，因为为NULL
    }
}; 

class MyThead1: public Thread
{
public:
    virtual void run()
    {
        sleep(1);
        cout << "MyThead1::run()" << endl;
        
    }
};

class MyThead2: public Thread
{
public:
    virtual void run()
    {
        cout << "MyThead2::run()" << endl;
    }
};

int main()
{
    MyThead1 t1;
    t1.start();
    
    MyThead2 t2;
    t2.start();
    
    sleep(2);
    
    return 0;
}