├── README
└── epoll.c


/README:
--------------------------------------------------------------------------------
1 | 
2 | a simple TCP server using EPOLL.
3 | 
4 | if you want to test it, please create a TCP client. with it, you can send message to this TCP server.
5 | 


--------------------------------------------------------------------------------
/epoll.c:
--------------------------------------------------------------------------------
  1 | 
  2 | #include <sys/socket.h>
  3 | #include <sys/epoll.h>
  4 | #include <netinet/in.h>
  5 | #include <arpa/inet.h>
  6 | #include <fcntl.h>
  7 | #include <unistd.h>
  8 | #include <stdio.h>
  9 | #include <errno.h>
 10 | #include <stdlib.h>
 11 | #include <string.h>
 12 | 
 13 | #define MAXLINE		10
 14 | #define OPEN_MAX	100
 15 | #define LISTENQ		20
 16 | #define SERV_PORT	5555
 17 | #define INFTIM		1000
 18 | 
 19 | void setnonblocking(int sock)
 20 | {
 21 | 	int opts;
 22 | 	opts = fcntl(sock, F_GETFL);
 23 | 
 24 | 	if(opts < 0) {
 25 | 		perror("fcntl(sock, GETFL)");
 26 | 		exit(1);
 27 | 	}
 28 | 
 29 | 	opts = opts | O_NONBLOCK;
 30 | 
 31 | 	if(fcntl(sock, F_SETFL, opts) < 0) {
 32 | 		perror("fcntl(sock, SETFL, opts)");
 33 | 		exit(1);
 34 | 	}
 35 | }
 36 | 
 37 | int main(int argc, char *argv[])
 38 | {
 39 | 	printf("epoll socket begins.\n");
 40 | 	int i, maxi, listenfd, connfd, sockfd, epfd, nfds;
 41 | 	ssize_t n;
 42 | 	char line[MAXLINE];
 43 | 	socklen_t clilen;
 44 | 
 45 | 	struct epoll_event ev, events[20];
 46 | 
 47 | 	epfd = epoll_create(256);
 48 | 
 49 | 	struct sockaddr_in clientaddr;
 50 | 	struct sockaddr_in serveraddr;
 51 | 
 52 | 	listenfd = socket(AF_INET, SOCK_STREAM, 0);
 53 | 
 54 | 	setnonblocking(listenfd);
 55 | 
 56 | 	ev.data.fd = listenfd;
 57 | 	ev.events = EPOLLIN | EPOLLET;
 58 | 
 59 | 	epoll_ctl(epfd, EPOLL_CTL_ADD, listenfd, &ev);
 60 | 
 61 | 	bzero(&serveraddr, sizeof(serveraddr));
 62 | 	serveraddr.sin_family = AF_INET;
 63 | 	char *local_addr = "192.168.199.8";
 64 | 	inet_aton(local_addr, &(serveraddr.sin_addr));
 65 | 	serveraddr.sin_port = htons(SERV_PORT);
 66 | 
 67 | 	bind(listenfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));
 68 | 
 69 | 	listen(listenfd, LISTENQ);
 70 | 
 71 | 	maxi = 0;
 72 | 
 73 | 	for(; ;) {
 74 | 		nfds = epoll_wait(epfd, events, 20, 500);
 75 | 
 76 | 		for(i = 0; i < nfds; ++i) {
 77 | 			if(events[i].data.fd == listenfd) {
 78 | 				printf("accept connection, fd is %d\n", listenfd);
 79 | 				connfd = accept(listenfd, (struct sockaddr *)&clientaddr, &clilen);
 80 | 				if(connfd < 0) {
 81 | 					perror("connfd < 0");
 82 | 					exit(1);
 83 | 				}
 84 | 
 85 | 				setnonblocking(connfd);
 86 | 
 87 | 				char *str = inet_ntoa(clientaddr.sin_addr);
 88 | 				printf("connect from %s\n", str);
 89 | 
 90 | 				ev.data.fd = connfd;
 91 | 				ev.events = EPOLLIN | EPOLLET;
 92 | 				epoll_ctl(epfd, EPOLL_CTL_ADD, connfd, &ev);
 93 | 			}
 94 | 			else if(events[i].events & EPOLLIN) {
 95 | 				if((sockfd = events[i].data.fd) < 0) continue;
 96 | 				if((n = read(sockfd, line, MAXLINE)) < 0) {
 97 | 					if(errno == ECONNRESET) {
 98 | 						close(sockfd);
 99 | 						events[i].data.fd = -1;
100 | 					} else {
101 | 						printf("readline error");
102 | 					}
103 | 				} else if(n == 0) {
104 | 					close(sockfd);
105 | 					events[i].data.fd = -1;
106 | 				}
107 | 				
108 | 				printf("received data: %s\n", line);
109 | 
110 | 				ev.data.fd = sockfd;
111 | 				ev.events = EPOLLOUT | EPOLLET;
112 | 				epoll_ctl(epfd, EPOLL_CTL_MOD, sockfd, &ev);
113 | 			}
114 | 			else if(events[i].events & EPOLLOUT) {
115 | 				sockfd = events[i].data.fd;
116 | 				write(sockfd, line, n);
117 | 
118 | 				printf("written data: %s\n", line);
119 | 
120 | 				ev.data.fd = sockfd;
121 | 				ev.events = EPOLLIN | EPOLLET;
122 | 				epoll_ctl(epfd, EPOLL_CTL_MOD, sockfd, &ev);
123 | 			}
124 | 		}
125 | 	}
126 | }
127 | 


--------------------------------------------------------------------------------