#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/epoll.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <iostream>
#include <list>
#define BUF_SIZE 1024 //默认缓冲区
#define SERVER_PORT 44444 //监听端口
#define SERVER_HOST "172.16.1.210" //服务器IP地址
#define EPOLL_RUN_TIMEOUT -1 //epoll的超时时间
#define EPOLL_SIZE 20000 //epoll监听的客户端的最大数目
#define STR_WELCOME "Welcome to seChat! You ID is: Client #%d"
#define STR_MESSAGE "Client #%d>> %s"
#define STR_NOONE_CONNECTED "Noone connected to server except you!"
#define CMD_EXIT "EXIT"
//两个有用的宏定义：检查和赋值并且检测
#define CHK(eval) if(eval < 0){perror("eval"); exit(-1);}
#define CHK2(res, eval) if((res = eval) < 0){perror("eval"); exit(-1);}
using namespace std;
// 存放客户端socket描述符的list
list<int> clients_list;
//================================================================================================
//函数名： setnonblocking
//函数描述： 设置socket为不阻塞
//输入： [in] sockfd socket标示符
//输出： 无
//返回： 0
//================================================================================================
int setnonblocking(int sockfd)
{
int flags = fcntl(sockfd, F_GETFL, 0);
fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
return 0;
}
//================================================================================================
//函数名： handle_message
//函数描述： 处理每个客户端socket
//输入： [in] new_fd socket标示符
//输出： 无
//返回： 返回从客户端接受的数据的长度
//================================================================================================
int handle_message(int client)
{
char buf[BUF_SIZE], message[BUF_SIZE];
bzero(buf, BUF_SIZE);
bzero(message, BUF_SIZE);
int len;
CHK2(len,recv(client, buf, BUF_SIZE, 0)); //接受客户端信息
if(len == 0) //客户端关闭或出错，关闭socket，并从list移除socket
{
CHK(close(client));
clients_list.remove(client);
}
else //向客户端发送信息
{
if(clients_list.size() == 1)
{
CHK(send(client, STR_NOONE_CONNECTED, strlen(STR_NOONE_CONNECTED), 0));
return len;
}
sprintf(message, STR_MESSAGE, client, buf);
list<int>::iterator it;
for(it = clients_list.begin(); it != clients_list.end(); it++)
{
if(*it != client)
{
CHK(send(*it, message, BUF_SIZE, 0));
}
}
}
return len;
}
int main(int argc, char *argv[])
{
int listener; //监听socket
struct sockaddr_in addr, their_addr;
addr.sin_family = PF_INET;
addr.sin_port = htons(SERVER_PORT);
addr.sin_addr.s_addr = inet_addr(SERVER_HOST);
socklen_t socklen;
socklen = sizeof(struct sockaddr_in);
static struct epoll_event ev, events[EPOLL_SIZE];
ev.events = EPOLLIN | EPOLLET; //对读感兴趣，边沿触发
char message[BUF_SIZE];
int epfd; //epoll描述符
clock_t tStart; //计算程序运行时间
int client, res, epoll_events_count;
CHK2(listener, socket(PF_INET, SOCK_STREAM, 0)); //初始化监听socket
setnonblocking(listener); //设置监听socket为不阻塞
CHK(bind(listener, (struct sockaddr *)&addr, sizeof(addr))); //绑定监听socket
CHK(listen(listener, 1)); //设置监听
CHK2(epfd,epoll_create(EPOLL_SIZE)); //创建一个epoll描述符，并将监听socket加入epoll
ev.data.fd = listener;
CHK(epoll_ctl(epfd, EPOLL_CTL_ADD, listener, &ev));
while(1)
{
CHK2(epoll_events_count,epoll_wait(epfd, events, EPOLL_SIZE, EPOLL_RUN_TIMEOUT));
tStart = clock();
for(int i = 0; i < epoll_events_count ; i++)
{
if(events[i].data.fd == listener) //新的连接到来，将连接添加到epoll中，并发送欢迎消息
{
CHK2(client,accept(listener, (struct sockaddr *) &their_addr, &socklen));
setnonblocking(client);
ev.data.fd = client;
CHK(epoll_ctl(epfd, EPOLL_CTL_ADD, client, &ev));
clients_list.push_back(client); // 添加新的客户端到list
bzero(message, BUF_SIZE);
res = sprintf(message, STR_WELCOME, client);
CHK2(res, send(client, message, BUF_SIZE, 0));
}else
{
CHK2(res,handle_message(events[i].data.fd)); //注意：这里并没有调用epoll_ctl重新设置socket的事件类型，但还是可以继续收到客户端发送过来的信息
}
}
printf("Statistics: %d events handled at: %.2f second(s)\n", epoll_events_count, (double)(clock() - tStart)/CLOCKS_PER_SEC);
}
close(listener);
close(epfd);
return 0;
}
