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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/epoll.h>
#include <errno.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define MAXDATASIZE 1024
#define MAXCONN_NUM 10
#define MAXEVENTS 64
struct sockaddr_in server_addr;
struct sockaddr_in client_addr;
static int make_socket_non_blocking (int sockfd)
{
int flags, s;
flags = fcntl (sockfd, F_GETFL, 0);
if (flags == -1)
{
perror ("fcntl");
return -1;
}
flags |= O_NONBLOCK;
s = fcntl (sockfd, F_SETFL, flags);
if (s == -1)
{
perror ("fcntl");
return -1;
}
return 0;
}
static int create_and_bind(int port)
{
int sockfd;
if ( ( sockfd = socket ( AF_INET , SOCK_STREAM , 0) ) == -1)
{
perror ( "socket error" );
return -1;
}
memset(&client_addr, 0, sizeof(struct sockaddr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(port);
server_addr.sin_addr.s_addr = INADDR_ANY;
if ( bind( sockfd, ( struct sockaddr * ) &server_addr, sizeof(struct sockaddr) ) == -1)
{
perror ( "bind error" );
close (sockfd);
return -1;
}
return sockfd;
}
int main (int argc, char *argv[])
{
// 数据缓存区域
char buf[MAXDATASIZE];
// 检查是否指定端口
if (argc != 2)
{
fprintf (stderr, "Usage: %s [port]\n", argv[0]);
exit (EXIT_FAILURE);
}
char *port_argv = argv[1];
int port = atoi(port_argv);
// 创建并监听tcp socket
int sockfd = create_and_bind (port);
if (sockfd == -1)
{
abort ();
}
// 设置socket为非阻塞
if (make_socket_non_blocking (sockfd) == -1)
{
abort ();
}
// 创建epoll句柄
int epfd = epoll_create1 (0);
if (epfd == -1)
{
perror ("epoll_create error");
abort ();
}
// epoll_ctl
struct epoll_event event;
event.data.fd = sockfd;
event.events = EPOLLIN | EPOLLET;
if (epoll_ctl (epfd, EPOLL_CTL_ADD, sockfd, &event) == -1)
{
perror ("epoll_ctl error");
abort ();
}
/* Buffer where events are returned */
struct epoll_event *events;
events = calloc (MAXEVENTS, sizeof event);
// listen
if ( listen(sockfd, MAXCONN_NUM ) == -1)
{
perror ( "listen error" );
abort ();
}
/* The event loop */
while(1)
{
int n, i, new_fd, numbytes;
n = epoll_wait (epfd, events, MAXEVENTS, -1);
for (i = 0; i < n; i++)
{
/* We have a notification on the listening socket, which
means one or more incoming connections. */
if(events[i].data.fd == sockfd)
{
// accept
int sin_size = sizeof( struct sockaddr_in );
if ( ( new_fd = accept( sockfd, ( struct sockaddr * ) &client_addr, &sin_size) ) == -1)
{
perror ( "accept error" );
continue;
}
printf ("server: got connection from %s\n" , inet_ntoa( client_addr.sin_addr) ) ;
// epoll_ctl
event.data.fd = new_fd;
event.events = EPOLLIN | EPOLLET;
if (epoll_ctl (epfd, EPOLL_CTL_ADD, new_fd, &event) == -1)
{
perror ("epoll_ctl error");
abort ();
}
}
else if(events[i].events & EPOLLIN)
{
if((new_fd = events[i].data.fd) < 0)
continue;
if((numbytes = read(new_fd, buf, MAXDATASIZE)) < 0) {
if(errno == ECONNRESET) {
close(new_fd);
events[i].data.fd = -1;
epoll_ctl(epfd, EPOLL_CTL_DEL, new_fd, &event);
}
else
{
printf("readline error");
}
}
else if(numbytes == 0)
{
close(new_fd);
events[i].data.fd = -1;
epoll_ctl(epfd, EPOLL_CTL_DEL, new_fd, &event);
}
// numbytes > 0
else
{
printf("received data: %s\n", buf);
}
event.data.fd = new_fd;
event.events = EPOLLOUT | EPOLLET;
epoll_ctl(epfd, EPOLL_CTL_MOD, new_fd, &event);
}
else if(events[i].events & EPOLLOUT)
{
new_fd = events[i].data.fd;
write(new_fd, buf, numbytes);
printf("written data: %s\n", buf);
printf("written numbytes: %d\n", numbytes);
event.data.fd = new_fd;
event.events = EPOLLIN | EPOLLET;
epoll_ctl(epfd, EPOLL_CTL_MOD, new_fd, &event);
}
else if ((events[i].events & EPOLLERR) || (events[i].events & EPOLLHUP))
{
/* An error has occured on this fd, or the socket is not
ready for reading (why were we notified then?) */
fprintf (stderr, "epoll error\n");
new_fd = events[i].data.fd;
close(new_fd);
events[i].data.fd = -1;
epoll_ctl(epfd, EPOLL_CTL_DEL, new_fd, &event);
continue;
}
}
}
}
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