2023.07.29 驱动开发DAY6

通过epoll实现一个并发服务器

服务器

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/epoll.h>

#define ERR_MSG(msg)               \
do {                               \
    printf("LINE: %d\n", __LINE__);\
    perror(msg);                   \
} while(0)

#define PORT 6666
#define IP "127.0.0.1"

int main(int argc,const char * argv[])
{
    //创建流式套接字
    int sfd = socket(AF_INET, SOCK_STREAM, 0);
    if(sfd < 0)
    {
        ERR_MSG("socket");
        return -1;
    }
    printf("socket create success\n");

    //允许端口快速复用
    int reuse = 1;
    if(setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) < 0)
    {
        ERR_MSG("setsockopt");
        return -1;
    }
    printf("setsockopt success\n");

    //填充地址信息结构体
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(PORT);
    sin.sin_addr.s_addr = inet_addr(IP);

    //将IP地址和端口号绑定到指定的套接字文件描述符上
    if(bind(sfd, (struct sockaddr*)&sin, sizeof(sin)) < 0)
    {
        ERR_MSG("bind");
        return -1;
    }
    printf("bind success\n");
    
    //将通讯套接字设置为被动监听状态
    if(listen(sfd, 128) < 0)
    {
        ERR_MSG("listen");
        return -1;
    }
    printf("listen success\n");

    // 创建epoll句柄
    int epfd = epoll_create(1);
    if(epfd < 0)
    {
        printf("epoll_create filed\n");
        return -1;
    }

    // 添加准备就绪事件进入epoll;
    struct epoll_event event;
    struct epoll_event events[10]; //存放就绪事件描述符的数组
    event.events = EPOLLIN; // 读事件
    event.data.fd = sfd;
    if(epoll_ctl(epfd, EPOLL_CTL_ADD, sfd, &event) < 0)
    {
        printf("epoll_ctl add filed\n");
    }

    //监听事件是否发生
    struct sockaddr_in cin;        //存储客户端信息
    socklen_t len = sizeof(cin);
    struct sockaddr_in savecin[1024];
    int ret, res;
    char buf[128] = {};
    while(1)
    {
        //如果成功，ret接收返回的事件个数，把就绪的事件放在events数组中
        ret = epoll_wait(epfd, events, 10, -1);
        if(ret < 0)
        {
            printf("epoll_wait filed\n");
            return -1;
        }

        //循环遍历数组，做事件处理
        for(int i=0; i<ret; i++)
        {
            if(events[i].events & EPOLLIN)
            {
                if(events[i].data.fd == sfd)
                {
                    //触发客户端连接事件
                    int newfd = accept(sfd, (struct sockaddr*)&cin, &len);
                    if(newfd < 0)
                    {
                        ERR_MSG("accpet");
                        return -1;
                    }
                    printf("[%s:%d] 客户端连接成功 newfd=%d\n", inet_ntoa(cin.sin_addr), ntohs(cin.sin_port), newfd);
                    savecin[newfd] = cin;

                    //添加新连接客户端进入epoll;
                    event.events = EPOLLIN; // 读事件
                    event.data.fd = newfd;
                    if(epoll_ctl(epfd, EPOLL_CTL_ADD, newfd, &event) < 0)
                    {
                        printf("epoll_ctl add filed\n");
                        return -1;
                    }
                }
                else
                {
                    //触发客户端交互事件                   
                    //接收数据
                    int cfd = events[i].data.fd;
                    bzero(buf, sizeof(buf));
                    res = recv(cfd, buf, sizeof(buf), 0);
                    if(res < 0)
                    {
                        ERR_MSG("recv");
                        return -1;
                    }
                    else if(res == 0)
                    {
                        printf("[%s:%d] 客户端下线 cfd=%d\n", inet_ntoa(savecin[cfd].sin_addr), ntohs(savecin[cfd].sin_port), cfd);
                        close(cfd); // 关闭文件描述符
                        
                        //添加断开连接的客户端从epoll中删除;
                        if(epoll_ctl(epfd, EPOLL_CTL_DEL, cfd, NULL) < 0)
                        {
                            printf("epoll_ctl del filed\n");
                            return -1;
                        }
                        continue;
                    }
                    printf("[%s:%d] cfd=%d: %s\n", inet_ntoa(savecin[cfd].sin_addr), ntohs(savecin[cfd].sin_port), cfd, buf);
 
                    // 发送数据
                    strcat(buf, "*_*");
                    if(send(cfd, buf, sizeof(buf), 0) < 0)
                    {
                        ERR_MSG("send");
                        return -1;
                    }
                }
            }
        }
    }
    return 0;
}

客户端

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>


#define ERR_MSG(msg)               \
do {                               \
    printf("LINE: %d\n", __LINE__);\
    perror(msg);                   \
} while(0)

#define PORT 6666
#define IP "127.0.0.1"

int main(int argc,const char * argv[])
{
    //创建流式套接字
    int cfd = socket(AF_INET, SOCK_STREAM, 0);
    if(cfd < 0)
    {
        ERR_MSG("socket");
        return -1;
    }
    printf("socket create success\n");

    //填充地址信息结构体
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(PORT);
    sin.sin_addr.s_addr = inet_addr(IP);

    //连接到服务器
    if(connect(cfd, (struct sockaddr*)&sin, sizeof(sin)) < 0)
    {
        ERR_MSG("connect");
        return -1;
    }
    printf("connect server success\n");

    char buf[128] = "";
    ssize_t res = 0;
    while(1)
    {
        //发送数据
        bzero(buf, sizeof(buf));
        printf("请输入>>> ");
        fgets(buf, sizeof(buf), stdin);
        buf[strlen(buf)-1] = 0;
 
        if(send(cfd, buf, sizeof(buf), 0) < 0)
        {
            ERR_MSG("send");
            return -1;
        }
        printf("发送成功\n");
 
        //接收数据
        bzero(buf, sizeof(buf));
        res = recv(cfd, buf, sizeof(buf), 0);
        if(res < 0)
        {
            ERR_MSG("recv");
            return -1;
        }
        else if(0 == res)
        {
            printf("[%s:%d] 服务器下线\n", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
            break;
        }
        printf("[%s:%d]: %s\n", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), buf); 
    }
 
    close(cfd);
    return 0;
}

运行结果