LInux下C语言使用epoll实现网络并发

心已赠人 2022-12-23 03:28 154阅读 0赞

#include<stdio.h>
    #include<unistd.h>
    #include<sys/socket.h>
    #include<stdlib.h>
    #include<arpa/inet.h>
    #include<ctype.h>
    #include <sys/epoll.h>
    
    #define SERV_PORT 10002
    int main()
    { 
        struct epoll_event tmp,ep[5];//創建epoll的對象
        int lfd,cfd;
        ssize_t n;
        char buf[BUFSIZ],clien_IP[BUFSIZ];
        struct sockaddr_in serv_addr,client_addr;
    
        lfd = socket(AF_INET,SOCK_STREAM,0);
        serv_addr.sin_port = htons(SERV_PORT);
        serv_addr.sin_family = AF_INET;
        serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    
        int opt = 1;
        setsockopt(lfd,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof opt);
    
        if(bind(lfd,(struct sockaddr *)&serv_addr,sizeof serv_addr) == -1)//
        { 
            perror("bind error\n");
        }
        listen(lfd,2);
    
        //創建epollfd，即是紅黑樹的根節
        int epfd = epoll_create(5);
        if(epfd == -1)
        { 
            perror("epoll_creat error!!\n");
            return -1;
        }
        tmp.events = EPOLLIN;tmp.data.fd = lfd;
        if(-1 == epoll_ctl(epfd,EPOLL_CTL_ADD,lfd,&tmp))
        { 
                perror("epoll_ctl error!!!\n");
                return -1;
        }
        while(1)
        { 
            int res = epoll_wait(epfd,ep,5,-1);
            if(res == -1)
            { 
                perror("wait shibai");
                return -1;
            }
            int ii = 0;
            for(ii = 0; ii < res; ii++)
            { 
                if(!(ep[ii].events & EPOLLIN))
                { 
                    continue;//如果不是讀事件直接跳過
                }
                if(ep[ii].data.fd == lfd)
                { 
                    socklen_t client_addr_size = sizeof client_addr;
                    cfd = accept(lfd,(struct sockaddr *)&client_addr,&client_addr_size);
                    printf("client IP:%s,Port:%d\n",inet_ntop(AF_INET,&client_addr.sin_addr.s_addr,clien_IP,sizeof clien_IP),ntohs(client_addr.sin_port));
                    tmp.events = EPOLLIN;tmp.data.fd = cfd;
                    int res = epoll_ctl(epfd,EPOLL_CTL_ADD,cfd, &tmp);
                    if(res == -1)
                    { 
                        perror("epoll_ctl error");
                        break;
                    }
    }
                else{ 
                    n = read(ep[ii].data.fd,buf,sizeof buf);
                    if(n == 0)
                    { 
                        epoll_ctl(epfd,EPOLL_CTL_DEL,ep[ii].data.fd,NULL);
                        close(ep[ii].data.fd);
                        continue;
                    }
                    int i = 0;
                    while(buf[i] != '\0')
                    { 
                        buf[i] = toupper(buf[i]);
                        i++;
                    }
                    write(ep[ii].data.fd,buf,n);
                }
                }
            }
    
    }