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网络服务器事件驱动模型优化与实现

事件驱动模型与线程设计

在网络服务器开发中，事件驱动模型是处理I/O请求和网络连接的核心机制。传统的线程模型通常采用单线程或多线程模型，但随着网络应用的复杂化，多线程模型逐渐成为主流。以下是本文将要探讨的主要结构体和实现细节。

结构体定义

事件循环线程结构体

struct event_loop_thread {    struct event_loop *eventLoop;    pthread_t thread_tid;    /* 线程ID */    pthread_mutex_t mutex;    pthread_cond_t cond;    char *thread_name;    long thread_count;    /* 处理连接的数量 */};

TCP连接结构体

struct tcp_connection {    struct event_loop *eventLoop;    struct channel *channel;    char *name;    struct buffer *input_buffer;    /* 接收缓冲区 */    struct buffer *output_buffer;   /* 发送缓冲区 */    void *data;    /* 回调使用 */    void *request;    /* 回调使用 */    void *response;    /* 回调使用 */};

功能流程

主线程流程

子线程流程

服务器启动流程

void tcp_server_start(struct TCPserver *tcpServer) {    struct acceptor *acceptor = tcpServer->acceptor;    struct event_loop *eventLoop = tcpServer->eventLoop;        // 启动线程池    thread_pool_start(tcpServer->threadPool);        // 创建并添加监听channel    struct channel *channel = channel_new(acceptor->listen_fd,                                          EVENT_READ,                                          handle_connection_established,                                          NULL,                                         tcpServer);    event_loop_add_channel_event(eventLoop, channel->fd, channel);}

事件处理回调

int handle_connection_established(void *data) {    struct TCPserver *tcpServer = (struct TCPserver *) data;    struct acceptor *acceptor = tcpServer->acceptor;    int listenfd = acceptor->listen_fd;        // 接收新连接    struct sockaddr_in client_addr;    socklen_t client_len = sizeof(client_addr);    int connected_fd = accept(listenfd, (struct sockaddr *) &client_addr, &client_len);    make_nonblocking(connected_fd);        // 获取事件循环    struct event_loop *eventLoop = thread_pool_get_loop(tcpServer->threadPool);        // 创建新的TCP连接    struct tcp_connection *tcpConnection = tcp_connection_new(        connected_fd,         eventLoop,         tcpServer->connectionCompletedCallBack,        tcpServer->connectionClosedCallBack,        tcpServer->messageCallBack,        tcpServer->writeCompletedCallBack    );        // 设置回调数据    if (tcpServer->data != NULL) {        tcpConnection->data = tcpServer->data;    }        return 0;}

线程池实现

void thread_pool_start(struct thread_pool *threadPool) {    if (!threadPool->started) {        threadPool->started = true;        // 初始化事件循环线程        threadPool->eventLoopThreads = malloc(threadPool->thread_number * sizeof(struct event_loop_thread));        for (int i = 0; i < threadPool->thread_number; ++i) {            event_loop_thread_init(&threadPool->eventLoopThreads[i], i);            event_loop_thread_start(&threadPool->eventLoopThreads[i]);        }    }}

线程初始化

int event_loop_thread_init(struct event_loop_thread *eventLoopThread, int i) {    pthread_mutex_init(&eventLoopThread->mutex, NULL);    pthread_cond_init(&eventLoopThread->cond, NULL);    eventLoopThread->eventLoop = NULL;    eventLoopThread->thread_count = 0;    eventLoopThread->thread_tid = 0;    char *buf = malloc(16);    sprintf(buf, "Thread-%d\0", i + 1);    eventLoopThread->thread_name = buf;    return 0;}

线程启动

struct event_loop *event_loop_thread_start(struct event_loop_thread *eventLoopThread) {    pthread_create(&eventLoopThread->thread_tid, NULL, &event_loop_thread_run, eventLoopThread);        pthread_mutex_lock(&eventLoopThread->mutex);    while (eventLoopThread->eventLoop == NULL) {        pthread_cond_wait(&eventLoopThread->cond, &eventLoopThread->mutex);    }    pthread_mutex_unlock(&eventLoopThread->mutex);        yolanda_msgx("event loop thread started, %s", eventLoopThread->thread_name);    return eventLoopThread->eventLoop;}

事件循环运行

int event_loop_run(struct event_loop *eventLoop) {    assert(eventLoop != NULL);    struct event_dispatcher *dispatcher = eventLoop->eventDispatcher;        if (eventLoop->owner_thread_id != pthread_self()) {        exit(1);    }        yolanda_msgx("event loop run, %s", eventLoop->thread_name);        struct timeval timeval;    timeval.tv_sec = 1;    while (!eventLoop->quit) {        event_loop_handle_pending_channel(eventLoop);    }        yolanda_msgx("event loop end, %s", eventLoop->thread_name);    return 0;}

代码优化

总结

上述实现展示了一个基于事件驱动的网络服务器框架，通过线程池和事件循环机制，实现了高效的网络连接处理。该设计能够在多线程环境下，动态管理服务器资源，确保网络应用的稳定性和性能。