Linux下socket通信和epoll

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h> // open function
#include <unistd.h> // close function
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <pthread.h>
#include <errno.h>
#include <sys/epoll.h> const int PORT = ;
/*
listen_loop(): epoll监听套接字，作不同处理
accept_conn(): 新的客户端连接进来，执行accept，将fd加入epoll set
recv_message(): recv并且重复输出一份给客户端
*/
void listen_loop();
void accept_conn(unsigned int sock_fd, unsigned int epollfd);
void recv_message(unsigned int sock_fd); int main(void) {
int sock_fd;
struct sockaddr_in server_addr; //初始化socket
sock_fd = socket(AF_INET, SOCK_STREAM, );
if (sock_fd < ) {
perror("socket:");
return ;
} //编辑地址
memset(&server_addr, , sizeof(server_addr));
server_addr.sin_family = AF_INET;//ipv_4
server_addr.sin_port = htons(PORT);//监听端口8888
server_addr.sin_addr.s_addr = INADDR_ANY;//本地的任意地址 //绑定然后监听
if (bind(sock_fd, (struct sockaddr*)&server_addr, sizeof(server_addr)) < ) {
perror("bind:");
return ;
}
if (listen(sock_fd, ) < ) {
perror("listen");
return ;
} listen_loop(sock_fd); return ;
}
void accept_conn(unsigned int sock_fd, unsigned int epollfd) {
struct sockaddr_in clientaddr;
struct epoll_event event;
socklen_t len = sizeof(struct sockaddr);
int accept_fd = ; accept_fd = accept(sock_fd, (struct sockaddr*)&clientaddr, &len); if (accept_fd <= ) {
perror("accept error");
return;
} //将新建连接加入epoll set
event.data.fd = accept_fd;
event.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
epoll_ctl(epollfd, EPOLL_CTL_ADD, accept_fd, &event);
return;
} void recv_message(unsigned int sock_fd) {
char recv_buf[], send_buf[]; memset(recv_buf, , sizeof(recv_buf));
memset(send_buf, , sizeof(send_buf)); recv(sock_fd, recv_buf, sizeof(recv_buf), );
fputs(recv_buf, stdout);
strcpy(send_buf, recv_buf);
send(sock_fd, send_buf, sizeof(send_buf), ); return;
}
void listen_loop(unsigned int sock_fd)
{
int epollfd, i, ret;
int timeout = ;
struct epoll_event event;
struct epoll_event eventList[]; /*创建epoll监听事件*/
epollfd = epoll_create();
event.events = EPOLLIN | EPOLLET;
event.data.fd = sock_fd; /*注册epoll监听事件.*/
if (epoll_ctl(epollfd, EPOLL_CTL_ADD, sock_fd, &event) < ) {
printf("register epoll event err !");
return;
} while () {
ret = epoll_wait(epollfd, eventList, , timeout); /*epoll事件错误.*/
if (ret < ) {
printf("epoll event err!");
break;
}
/*无事件返回.*/
else if (ret == ) {
continue;
} /*epoll返回事件.*/
for (i = ; i < ret; i++) {
/*epoll 错误*/
if ((eventList[i].events & EPOLLERR) || (eventList[i].events & EPOLLHUP) || !(eventList[i].events & EPOLLIN)) {
printf("epoll error\n");
close(eventList[i].data.fd);
exit(-);
} //half connection
if (eventList[i].events & EPOLLRDHUP) {
printf("//one client close the conne.//\n");
close(eventList[i].data.fd);
} /*accept事件*/
if (eventList[i].data.fd == sock_fd) {
accept_conn(sock_fd, epollfd);
}
/*非sock_fd则为其他事件.*/
else {
recv_message(eventList[i].data.fd);
}
}
}
close(epollfd);
close(sock_fd);
return;
}