epoll

#include "local.h"
#include "utils.h"

using namespace std;

// 存放客户端socket描述符的list
list<int> clients_list;

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));          //把被监听的fd和监听的事件放入epoll的文件描述符中
//

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;
}

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;
}