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swoole源码-主线程和reactor线程交互流程

swoole源码-主线程和reactor线程交互流程

作者: cc180912 | 来源:发表于2018-12-05 20:51 被阅读7次

    swoole的整体数据流程图可以看官方文档swoole运行流程

    在主进程中有两个关键线程 主线程和reactor线程, 主线程用来处理 accept() 事件,创建新的socket fd, 接收到新连接后会把新的socket 连接放到reactor线程的的事件监听循环中, reactor线程负责接收从client端发过来的数据,按协议解析后,通过pipe管道传输给worker进程处理,worker进程处理完后,把结果通过pipe回传给reactor线程,reactor线程再按协议把结果通过socket发送给client。 可以看到reactor线程负责数据的IO和传输,在linux环境下,这些IO事件通过epoll机制来处理。

    下一步我们看下主线程和 reactor线程数据交换的过程的源码

    第一步要找到 swServer_start(swServer *serv) 函数, 这个是swoole启动server的入口,在这个函数中很容易就能读到这么一句

    int swServer_start(swServer *serv) {
        ......
        ret = swServer_start_proxy(serv);  //启动主线程和reactor线程,并注册各种事件处理函数,和协议解析
    
        ......
    }
    

    下面着重讲 swServer_start_proxy

    //src/network/Server.c
    
    static int swServer_start_proxy(swServer *serv)
    {
        int ret;
        swReactor *main_reactor = SwooleG.memory_pool->alloc(SwooleG.memory_pool, sizeof(swReactor));
    
        ret = swReactor_create(main_reactor, SW_REACTOR_MAXEVENTS); // 创建主线程reactor对象事件处理,只是创建对象,主线程不用pthread_create() 真正去创建线程
        //...... // 省略区
    
        ret = swReactorThread_start(serv, main_reactor);  //把server监听端口的listen事件加入到主线程事件监听,创建reactor线程
        
         //...... // 省略区
     
        main_reactor->setHandle(main_reactor, SW_FD_LISTEN, swServer_master_onAccept); //主线程reactor listen事件处理handle
    
    
         //...... // 省略区
        return main_reactor->wait(main_reactor, NULL); //主线程循环
    }
    
    
    int swReactorThread_start(swServer *serv, swReactor *main_reactor_ptr)
    {
    //..... 省略区
        swListenPort *ls;
        LL_FOREACH(serv->listen_list, ls)
        {
            if (ls->type == SW_SOCK_UDP || ls->type == SW_SOCK_UDP6 || ls->type == SW_SOCK_UNIX_DGRAM)
            {
                continue;
            }
            main_reactor_ptr->add(main_reactor_ptr, ls->sock, SW_FD_LISTEN); //把监听的端口fd加入到 主线程事件监听循环中
        }
    
    //..... 省略区
        return SW_OK;
    }
    
    int swServer_master_onAccept(swReactor *reactor, swEvent *event)
    {
    
        //..... 省略区
        //SW_ACCEPT_AGAIN
        for (i = 0; i < SW_ACCEPT_MAX_COUNT; i++)
        {
            new_fd = accept(event->fd, (struct sockaddr *) &client_addr, &client_addrlen);  // accept新socket
        //..... 省略区
    
            if (sub_reactor->add(sub_reactor, new_fd, SW_FD_TCP | SW_EVENT_WRITE) < 0)  //新socket加入到 reactor线程事件监听中
            {
                bzero(conn, sizeof(swConnection));
                close(new_fd);
                return SW_OK;
            }
        }
        return SW_OK;
    }
    
    
    1. swReactor_create() , 创建主线程reactor对象,只是创建对象,主线程不用pthread_create() 真正去创建线程,主线程就在主进程中
    2. swReactorThread_start() , 这里面主要分成两件事, 一个是把server监听端口的listen事件加入到主线程事件监听中去,这样一旦有连接达到监听端口就会调用主线程的 swServer_master_onAccept()来处理新连接。 另外一件事就是创建reactor线程并注册各种事件监听和协议处理
      3.main_reactor->setHandle() , 这个注册主线程reactor listen事件处理handle , 也就是注册swServer_master_onAccept()
      4.main_reactor->wait(main_reactor, NULL); 这个是主线程循环,主线程一直在这个函数中循环,等待新连接,然后把新连接通过swServer_master_onAccept() ,拿到新的socket, 再把新的socket , 通过 sub_reactor->add(sub_reactor, new_fd, SW_FD_TCP | SW_EVENT_WRITE) 加入到reactor线程的事件处理循环中

    同过上面的几部可以清楚的看到主线程是如何监听listen事件,又是如何accept()新连接, 并把新连接加入到reactor线程的监听中的

    下面继续说reactor线程

    reactor线程通过 swReactorThread_start() , 调用创建

    //src/network/ReactorThread.c 函数中间有省略,只粘贴了关键部分
    
    int swReactorThread_start(swServer *serv, swReactor *main_reactor_ptr)
    {
        //..... 省略区
        //create reactor thread
        for (i = 0; i < serv->reactor_num; i++)
        {
            thread = &(serv->reactor_threads[i]);
            param = SwooleG.memory_pool->alloc(SwooleG.memory_pool, sizeof(swThreadParam));
            if (param == NULL)
            {
                swError("malloc failed");
                return SW_ERR;
            }
    
            param->object = serv;
            param->pti = i;
    
            if (pthread_create(&pidt, NULL, (void * (*)(void *)) swReactorThread_loop, (void *) param) < 0)
            {
                swError("pthread_create[tcp_reactor] failed. Error: %s[%d]", strerror(errno), errno);
            }
            thread->thread_id = pidt;
        }
    
    
        return SW_OK;
    }
    

    pthread_create 创建reactor线程, 线程的循环函数是swReactorThread_loop

    //src/network/ReactorThread.c  函数中间有省略,只粘贴了关键部分
    
    static int swReactorThread_loop(swThreadParam *param)
    {
       
        //创建线程reactor对象
        swReactor *reactor = &thread->reactor;
        ret = swReactor_create(reactor, SW_REACTOR_MAXEVENTS);
    
    
        //注册pipe管道的事件处理handle
        reactor->setHandle(reactor, SW_FD_CLOSE, swReactorThread_onClose);
        reactor->setHandle(reactor, SW_FD_PIPE | SW_EVENT_READ, swReactorThread_onPipeReceive);
        reactor->setHandle(reactor, SW_FD_PIPE | SW_EVENT_WRITE, swReactorThread_onPipeWrite);
    
    
        //set protocol function point  添加socket read write事件监听, 并注册协议处理函数
        swReactorThread_set_protocol(serv, reactor);
    
    
        // reactor线程循环  
        reactor->wait(reactor, NULL);
        //shutdown
        reactor->free(reactor);
    
        return SW_OK;
    }
    
    void swReactorThread_set_protocol(swServer *serv, swReactor *reactor)
    {
        //UDP Packet
        reactor->setHandle(reactor, SW_FD_UDP, swReactorThread_onPackage);
        //Write   socket 可写事件处理handle
        reactor->setHandle(reactor, SW_FD_TCP | SW_EVENT_WRITE, swReactorThread_onWrite);
        //Read  socket 可读事件处理handle
        reactor->setHandle(reactor, SW_FD_TCP | SW_EVENT_READ, swReactorThread_onRead);
    
        swListenPort *ls;
        //listen the all tcp port
        LL_FOREACH(serv->listen_list, ls)
        {
            if (swSocket_is_dgram(ls->type))
            {
                continue;
            }
            swPort_set_protocol(ls);  //协议处理解析, 比如http、http2、websocket、mqtt等
        }
    }
    

    swPort_set_protocol 协议处理函数

    //src/network/Port.c
    void swPort_set_protocol(swListenPort *ls)
    {
        //Thread mode must copy the data.
        //will free after onFinish
        if (ls->open_eof_check)
        {
            if (ls->protocol.package_eof_len > sizeof(ls->protocol.package_eof))
            {
                ls->protocol.package_eof_len = sizeof(ls->protocol.package_eof);
            }
            ls->protocol.onPackage = swReactorThread_dispatch;
            ls->onRead = swPort_onRead_check_eof;
        }
        else if (ls->open_length_check)
        {
            if (ls->protocol.package_length_type != '\0')
            {
                ls->protocol.get_package_length = swProtocol_get_package_length;
            }
            ls->protocol.onPackage = swReactorThread_dispatch;
            ls->onRead = swPort_onRead_check_length;
        }
        else if (ls->open_http_protocol)
        {
            if (ls->open_websocket_protocol)
            {
                ls->protocol.get_package_length = swWebSocket_get_package_length;
                ls->protocol.onPackage = swWebSocket_dispatch_frame;
                ls->protocol.package_length_size = SW_WEBSOCKET_HEADER_LEN + SW_WEBSOCKET_MASK_LEN + sizeof(uint64_t);
            }
    #ifdef SW_USE_HTTP2
            else if (ls->open_http2_protocol)
            {
                ls->protocol.get_package_length = swHttp2_get_frame_length;
                ls->protocol.package_length_size = SW_HTTP2_FRAME_HEADER_SIZE;
                ls->protocol.onPackage = swReactorThread_dispatch;
            }
    #endif
            ls->onRead = swPort_onRead_http; //**http协议处理**
        }
        else if (ls->open_mqtt_protocol)
        {
            ls->protocol.get_package_length = swMqtt_get_package_length;
            ls->protocol.onPackage = swReactorThread_dispatch;
            ls->onRead = swPort_onRead_check_length;
        }
        else if (ls->open_redis_protocol)
        {
            ls->protocol.onPackage = swReactorThread_dispatch;
            ls->onRead = swPort_onRead_redis;
        }
        else
        {
            ls->onRead = swPort_onRead_raw;
        }
    }

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