epoll/serv.c

   1 #include <sys/socket.h>
   2 #include <sys/wait.h>
   3 #include <netinet/in.h>
   4 #include <netinet/tcp.h>
   5 #include <sys/epoll.h>
   6 #include <sys/sendfile.h>
   7 #include <sys/stat.h>
   8 #include <unistd.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <strings.h>
  13 #include <fcntl.h>
  14 #include <errno.h>
  15
  16 #define MAX_EVENTS 10
  17 #define PORT 8080
  18
  19 //设置socket连接为非阻塞模式
  20 void setnonblocking(int sockfd) {
  21         int opts;
  22
  23         opts = fcntl(sockfd, F_GETFL);
  24         if(opts < 0) {
  25                 perror("fcntl(F_GETFL)\n");
  26                 exit(1);
  27         }
  28         opts = (opts | O_NONBLOCK);
  29         if(fcntl(sockfd, F_SETFL, opts) < 0) {
  30                 perror("fcntl(F_SETFL)\n");
  31                 exit(1);
  32         }
  33 }
  34
  35 int main(){
  36         //ET模式的简单HTTP服务器代码
  37
  38         struct epoll_event ev, events[MAX_EVENTS];
  39         int addrlen, listenfd, conn_sock, nfds, epfd, fd, i, nread, n;
  40         struct sockaddr_in local, remote;
  41         char buf[BUFSIZ];
  42
  43         //创建listen socket
  44         if( (listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
  45                 perror("sockfd\n");
  46                 exit(1);
  47         }
  48         setnonblocking(listenfd);
  49         bzero(&local, sizeof(local));
  50         local.sin_family = AF_INET;
  51         local.sin_addr.s_addr = htonl(INADDR_ANY);;
  52         local.sin_port = htons(PORT);
  53         if( bind(listenfd, (struct sockaddr *) &local, sizeof(local)) < 0) {
  54                 perror("bind\n");
  55                 exit(1);
  56         }
  57         listen(listenfd, 20);
  58
  59         epfd = epoll_create(MAX_EVENTS);
  60         if (epfd == -1) {
  61                 perror("epoll_create");
  62                 exit(EXIT_FAILURE);
  63         }
  64
  65         ev.events = EPOLLIN;
  66         ev.data.fd = listenfd;
  67         if (epoll_ctl(epfd, EPOLL_CTL_ADD, listenfd, &ev) == -1) {
  68                 perror("epoll_ctl: listen_sock");
  69                 exit(EXIT_FAILURE);
  70         }
  71
  72         for (;;) {
  73                 nfds = epoll_wait(epfd, events, MAX_EVENTS, -1);
  74                 if (nfds == -1) {
  75                         perror("epoll_pwait");
  76                         exit(EXIT_FAILURE);
  77                 }
  78
  79                 for (i = 0; i < nfds; ++i) {
  80                         fd = events[i].data.fd;
  81                         if (fd == listenfd) {
  82                                 // ET下,正确的accept
  83                                 while ((conn_sock = accept(listenfd,(struct sockaddr *) &remote,
  84                                                                 (size_t *)&addrlen)) > 0) {
  85                                         setnonblocking(conn_sock);
  86                                         ev.events = EPOLLIN | EPOLLET;
  87                                         ev.data.fd = conn_sock;
  88                                         if (epoll_ctl(epfd, EPOLL_CTL_ADD, conn_sock,
  89                                                                 &ev) == -1) {
  90                                                 perror("epoll_ctl: add");
  91                                                 exit(EXIT_FAILURE);
  92                                         }
  93                                 }
  94                                 if (conn_sock == -1) {
  95                                         if (errno != EAGAIN && errno != ECONNABORTED
  96                                                         && errno != EPROTO && errno != EINTR)
  97                                                 perror("accept");
  98                                 }
  99                                 continue;
 100                         }
 101                         if (events[i].events & EPOLLIN) {
 102                                 // ET下,正确的读
 103                                 n = 0;
 104                                 while ((nread = read(fd, buf + n, BUFSIZ-1)) > 0) {
 105                                         n += nread;
 106                                 }
 107                                 if (nread == -1 && errno != EAGAIN) {
 108                                         perror("read error");
 109                                 }
 110                                 ev.data.fd = fd;
 111                                 ev.events = events[i].events | EPOLLOUT;
 112                                 if (epoll_ctl(epfd, EPOLL_CTL_MOD, fd, &ev) == -1) {
 113                                         perror("epoll_ctl: mod");
 114                                 }
 115                         }
 116                         if (events[i].events & EPOLLOUT) {
 117                                 // ET下,正确的写
 118                                 sprintf(buf, "HTTP/1.1 200 OK\r\nContent-Length: %d\r\n\r\nHello World", 11);
 119                                 int nwrite, data_size = strlen(buf);
 120                                 n = data_size;
 121                                 while (n > 0) {
 122                                         nwrite = write(fd, buf + data_size - n, n);
 123                                         if (nwrite < n) {
 124                                                 if (nwrite == -1 && errno != EAGAIN) {
 125                                                         perror("write error");
 126                                                 }
 127                                                 break;
 128                                         }
 129                                         n -= nwrite;
 130                                 }
 131                                 close(fd);
 132                         }
 133                 }
 134         }
 135
 136         return 0;
 137 }