epoll多线程服务器代码，epoll示例程序——服务端

源码：

#include <sys/epoll.h> 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>
#include <netinet/in.h>
//返回值的宏定义，在开发linux环境时，用0表示成功
#define RES_SUC 0
#define RES_FAIL -1#define FD_NULL 0
#define null 0
#define MAX_EPOLL_FD 1024
#define LISTEN_SOCK_QUEUE 1024#define WORK_STATE_STOP 0
#define WORK_STATE_RUN 1
//服务器的监听端口
#define LISTNE_PORT 3557#define INVALID_SOCKET -1#define MAX_EPOLL_EVENTS 1024
//epoll在无事件发生时的最大返回间隔时间
#define EPOLL_WAIT_INTERVAL 100 #define  MAX_BUF_SIZE_READ 1024static int g_fd_epoll = FD_NULL;
static int g_fd_listen_sock = FD_NULL;
static int g_run_server = WORK_STATE_RUN;
int main()
{printf("[main] will start test server!\n");//初始化测试服务器if(init() == RES_FAIL){printf("[main] init fail!\n");return RES_FAIL;}// 开始长循环工作if(main_loop() == RES_FAIL){printf("[main] main_loop fail!\n");return RES_FAIL;}printf("[main] test server will exit!\n");return RES_SUC;
}
/**
*初始化服务端程序，成功返回RES_SUC
*/
int init()
{//创建epoll的句柄g_fd_epoll = epoll_create(MAX_EPOLL_FD);if(g_fd_epoll <= 0){printf("[init] epoll_create fail!\n");return RES_FAIL;}//初始化监听socketif(init_listen_socket() == RES_FAIL){printf("[init] epoll_create fail!\n");return RES_FAIL;}return RES_SUC;
}
/*
*初始化监听socket，成功则返回创建的监听socket，否则返回RES_FAIL
*/
int init_listen_socket()
{printf("[init_listen_socket] will init listen socket!\n");//创建监听socket的句柄g_fd_listen_sock = socket(AF_INET, SOCK_STREAM, 0);if(INVALID_SOCKET == g_fd_listen_sock){printf("[init_listen_socket] create listen socket fail!\n");return RES_FAIL;}//设置监听socket的状态为非阻塞int opt = 1;opt = fcntl(g_fd_listen_sock, F_GETFL, 0);if(opt == -1 || fcntl(g_fd_listen_sock, F_SETFL, opt | O_NONBLOCK) == -1){printf("[init_listen_socket] set socket state: O_NONBLOCK fail!\n");close(g_fd_listen_sock);return RES_FAIL;}//绑定socket到本地端口struct sockaddr_in serv_addr;serv_addr.sin_family = AF_INET;serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);  // 使用本地通配地址serv_addr.sin_port = htons(LISTNE_PORT); if(bind(g_fd_listen_sock, (struct sockaddr *)&serv_addr, sizeof( serv_addr)) != RES_SUC){printf("[init_listen_socket] bind socket to port %d fail!\n", LISTNE_PORT);close(g_fd_listen_sock);return RES_FAIL;}//开启socket的监听状态if(listen(g_fd_listen_sock, LISTEN_SOCK_QUEUE) == -1){printf("[init_listen_socket] listen socket fail!\n");close(g_fd_listen_sock);return RES_FAIL;}//注册监听socket到epollif(reg_socket(g_fd_listen_sock) == RES_FAIL){printf("[init_listen_socket] reg_socket fail!\n");return RES_FAIL;}printf("[init_listen_socket] init listen socket suc!\n");return g_fd_listen_sock;
}
//注册一个socket到epoll
int reg_socket(int new_sock)
{if(new_sock <= 0)return RES_FAIL;struct epoll_event new_events;new_events.data.fd = new_sock;new_events.events = EPOLLIN;//我们只关注有数据到来if(epoll_ctl(g_fd_epoll, EPOLL_CTL_ADD,new_sock, &new_events) < 0){printf("[reg_socket] register socket into epoll faill!\n");return RES_FAIL;}else		return RES_SUC;				
}
//主循环体
int main_loop()
{//创建一个epoll事件的缓冲区，以便存放就绪的文件描述符struct epoll_event* epoll_events = null;epoll_events = (struct epoll_event*)malloc(sizeof(struct epoll_event) * MAX_EPOLL_EVENTS);if(epoll_events == null){printf("[main_loop] allocating memory for epoll events faill!\n");return RES_FAIL;}int fd_ready_num = 0;printf("[main_loop] server start success at port:%d!\n", LISTNE_PORT);while(g_run_server == WORK_STATE_RUN){//使用epoll来监控所有注册进来的socket，该步骤将以阻塞的方式用epoll_wait等待就绪的描述符，当一直没有描述符就绪时，最多将等待EPOLL_WAIT_INTERVAL毫秒之后，也会返回；fd_ready_num = epoll_wait(g_fd_epoll, epoll_events, MAX_EPOLL_EVENTS, EPOLL_WAIT_INTERVAL);//epoll_wait返回时说明有就绪的socket或者等待的超时时间到了int i = 0;for(i = 0; i < fd_ready_num; i++){if(epoll_events[i].data.fd == g_fd_listen_sock){//说明当前的描述符是一个监听socketif(handle_listen_socket() == RES_FAIL){printf("[main_loop] handle listen socket faill!\n");}continue;}//以下步骤将处理业务socketif(handle_business_socket(epoll_events[i].data.fd) == RES_FAIL){printf("[main_loop] handle business socket:%s faill!\n", epoll_events[i].data.fd);}}}
}//处理就绪的监听socket,接收新的连接进来，并为之产生一个业务socket
int handle_listen_socket()
{int new_sock = INVALID_SOCKET;new_sock = accept(g_fd_listen_sock, NULL, 0);if(new_sock == INVALID_SOCKET){printf("[handle_listen_socket] accept new socket faill!\n");return RES_FAIL;}//设置监听socket的状态为非阻塞int opt = 1;opt = fcntl(new_sock, F_GETFL, 0);if(opt == -1 || fcntl(new_sock, F_SETFL, opt | O_NONBLOCK) == -1){printf("[handle_listen_socket] set socket state: O_NONBLOCK fail!\n");close(new_sock);return RES_FAIL;}//注册监听socket到epollif(reg_socket(new_sock) == RES_FAIL){printf("[handle_listen_socket] reg_socket:%d fail!\n", new_sock);return RES_FAIL;}printf("[handle_listen_socket] accept new socket:%d suc!\n", new_sock);return RES_SUC;
}//处理就绪的业务socket
int handle_business_socket(int ready_socket)
{if(ready_socket == INVALID_SOCKET){printf("[handle_business_socket] socket:%d is invalid!\n", ready_socket);return RES_FAIL;}char* read_buf = (char* )malloc(sizeof(char) * MAX_BUF_SIZE_READ);memset(read_buf, '\0', MAX_BUF_SIZE_READ);int read_len = read(ready_socket, read_buf, MAX_BUF_SIZE_READ);if(read_len > 0){printf("[handle_business_socket] recv msg from socket:%d, content:%s\n", ready_socket, read_buf);if(write(ready_socket, read_buf, read_len) != read_len){printf("[handle_business_socket] write msg into socket:%d fail! content:[%s]!\n", ready_socket, read_buf);}}free(read_buf);
}

[root@clsserv202 echoserver]# gcc echo_server.c -o echo_server
[root@clsserv202 echoserver]# ./echo_server 
[main] will start test server!
[init_listen_socket] will init listen socket!
[init_listen_socket] init listen socket suc!
[main_loop] server start success at port:3557!

epoll多线程服务器代码，