10.1 Hello_World服务器

  1. #include <string.h>
  2. #include <errno.h>
  3. #include <stdio.h>
  4. #include <signal.h>
  5. #ifndef WIN32
  6. #include <netinet/in.h>
  7. # ifdef _XOPEN_SOURCE_EXTENDED
  8. #  include <arpa/inet.h>
  9. # endif
  10. #include <sys/socket.h>
  11. #endif
  13. #include <event2/bufferevent.h>
  14. #include <event2/buffer.h>
  15. #include <event2/listener.h>
  16. #include <event2/util.h>
  17. #include <event2/event.h>
  19. static const char MESSAGE[] = "Hello, World!\n";
  21. static const int PORT = 9995;
  23. static void listener_cb(struct evconnlistener *, evutil_socket_t,
  24.     struct sockaddr *, int socklen, void *);
  25. static void conn_writecb(struct bufferevent *, void *);
  26. static void conn_eventcb(struct bufferevent *, short, void *);
  27. static void signal_cb(evutil_socket_t, short, void *);
  29. int
  30. main(int argc, char **argv)
  31. {
  32.         struct event_base *base;
  33.         struct evconnlistener *listener;
  34.         struct event *signal_event;
  36.         struct sockaddr_in sin;
  37. #ifdef WIN32
  38.         WSADATA wsa_data;
  39.         WSAStartup(0x0201, &wsa_data);
  40. #endif
  42.         base = event_base_new();
  43.         if (!base) {
  44.                 fprintf(stderr, "Could not initialize libevent!\n");
  45.                 return 1;
  46.         }
  48.         memset(&sin, 0, sizeof(sin));
  49.         sin.sin_family = AF_INET;
  50.         sin.sin_port = htons(PORT);
  52.         listener = evconnlistener_new_bind(base, listener_cb, (void *)base,
  53.             LEV_OPT_REUSEABLE|LEV_OPT_CLOSE_ON_FREE, -1,
  54.             (struct sockaddr*)&sin,
  55.             sizeof(sin));
  57.         if (!listener) {
  58.                 fprintf(stderr, "Could not create a listener!\n");
  59.                 return 1;
  60.         }
  62.         signal_event = evsignal_new(base, SIGINT, signal_cb, (void *)base);
  64.         if (!signal_event || event_add(signal_event, NULL)<0) {
  65.                 fprintf(stderr, "Could not create/add a signal event!\n");
  66.                 return 1;
  67.         }
  69.         event_base_dispatch(base);
  71.         evconnlistener_free(listener);
  72.         event_free(signal_event);
  73.         event_base_free(base);
  75.         printf("done\n");
  76.         return 0;
  77. }
  79. static void
  80. listener_cb(struct evconnlistener *listener, evutil_socket_t fd,
  81.     struct sockaddr *sa, int socklen, void *user_data)
  82. {
  83.         struct event_base *base = user_data;
  84.         struct bufferevent *bev;
  86.         bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
  87.         if (!bev) {
  88.                 fprintf(stderr, "Error constructing bufferevent!");
  89.                 event_base_loopbreak(base);
  90.                 return;
  91.         }
  92.         bufferevent_setcb(bev, NULL, conn_writecb, conn_eventcb, NULL);
  93.         bufferevent_enable(bev, EV_WRITE);
  94.         bufferevent_disable(bev, EV_READ);
  96.         bufferevent_write(bev, MESSAGE, strlen(MESSAGE));
  97. }
  99. static void
  100. conn_writecb(struct bufferevent *bev, void *user_data)
  101. {
  102.         struct evbuffer *output = bufferevent_get_output(bev);
  103.         if (evbuffer_get_length(output) == 0) {
  104.                 printf("flushed answer\n");
  105.                 bufferevent_free(bev);
  106.         }
  107. }
  109. static void
  110. conn_eventcb(struct bufferevent *bev, short events, void *user_data)
  111. {
  112.         if (events & BEV_EVENT_EOF) {
  113.                 printf("Connection closed.\n");
  114.         } else if (events & BEV_EVENT_ERROR) {
  115.                 printf("Got an error on the connection: %s\n",
  116.                     strerror(errno));/*XXX win32*/
  117.         }
  118.         /* None of the other events can happen here, since we haven't enabled
  119.          * timeouts */
  120.         bufferevent_free(bev);
  121. }
  123. static void
  124. signal_cb(evutil_socket_t sig, short events, void *user_data)
  125. {
  126.         struct event_base *base = user_data;
  127.         struct timeval delay = { 2, 0 };
  129.         printf("Caught an interrupt signal; exiting cleanly in two seconds.\n");
  131.         event_base_loopexit(base, &delay);
  132. }