一个完整的 epoll + socket 的例子

http://www.felix021.com/blog/read.php?1879

epoll相关代码出自“man epoll”。发现在网上找相关代码还有点麻烦。

p.s. 推荐 apt-get source libevent 找找里面的 epoll.c 文件里的相关实现。

#include <stdio.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <unistd.h>#include <fcntl.h>#include <sys/types.h>#include <arpa/inet.h>#include <netinet/in.h>#include <sys/socket.h>#include <sys/epoll.h>#include <sys/wait.h>#define SERVPORT 9527 /*服务器监听端口号 */#define BACKLOG 10 /* 最大同时连接请求数 */void setnonblocking(int sock){ int opts; opts = fcntl(sock,F_GETFL); if(opts<0) { perror("fcntl(sock,GETFL)"); exit(1); } opts = opts|O_NONBLOCK; if(fcntl(sock,F_SETFL,opts)<0) { perror("fcntl(sock,SETFL,opts)"); exit(1); } }void do_use_fd(int client_fd){ const char str[] = "God bless you!/n"; if (send(client_fd, str, sizeof(str), 0) == -1) perror("send"); close(client_fd);}int main(){ int sockfd; struct sockaddr_in my_addr; struct sockaddr_in remote_addr; if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror("socket"); exit(1); } my_addr.sin_family = AF_INET; my_addr.sin_port = htons(SERVPORT); my_addr.sin_addr.s_addr = INADDR_ANY; bzero(&(my_addr.sin_zero), 8); if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1) { perror("bind"); exit(1); } printf("bind ok/n"); if (listen(sockfd, BACKLOG) == -1) { perror("listen"); exit(1); } printf("listen ok/b"); size_t sin_size = sizeof(struct sockaddr_in);#define MAX_EVENTS 10 struct epoll_event ev, events[MAX_EVENTS]; int conn_sock, nfds, epollfd; epollfd = epoll_create(10); if (epollfd == -1) { perror("epoll_create"); exit(EXIT_FAILURE); } printf("epoll_create/n"); ev.events = EPOLLIN; ev.data.fd = sockfd; if (epoll_ctl(epollfd, EPOLL_CTL_ADD, sockfd, &ev) == -1) { perror("epoll_ctl: sockfd"); exit(EXIT_FAILURE); } printf("epoll_ctl ok/n"); for (;;) { printf("start epoll_wait/n"); nfds = epoll_wait(epollfd, events, MAX_EVENTS, -1); if (nfds == -1) { perror("epoll_pwait"); exit(EXIT_FAILURE); } printf("epoll_wait returns, nfds = %d/n", nfds); for (int n = 0; n < nfds; ++n) { if (events[n].data.fd == sockfd) { conn_sock = accept(sockfd, (struct sockaddr *) &remote_addr, &sin_size); if (conn_sock == -1) { perror("accept"); exit(EXIT_FAILURE); } setnonblocking(conn_sock); ev.events = EPOLLIN | EPOLLET; ev.data.fd = conn_sock; if (epoll_ctl(epollfd, EPOLL_CTL_ADD, conn_sock, &ev) == -1) { perror("epoll_ctl: conn_sock"); exit(EXIT_FAILURE); } } else { do_use_fd(events[n].data.fd); } } }}