diff options
Diffstat (limited to 'libevent/sample/hello-world.c')
-rw-r--r-- | libevent/sample/hello-world.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/libevent/sample/hello-world.c b/libevent/sample/hello-world.c new file mode 100644 index 0000000..a13e06a --- /dev/null +++ b/libevent/sample/hello-world.c @@ -0,0 +1,140 @@ +/* + This example program provides a trivial server program that listens for TCP + connections on port 9995. When they arrive, it writes a short message to + each client connection, and closes each connection once it is flushed. + + Where possible, it exits cleanly in response to a SIGINT (ctrl-c). +*/ + + +#include <string.h> +#include <errno.h> +#include <stdio.h> +#include <signal.h> +#ifndef _WIN32 +#include <netinet/in.h> +# ifdef _XOPEN_SOURCE_EXTENDED +# include <arpa/inet.h> +# endif +#include <sys/socket.h> +#endif + +#include <event2/bufferevent.h> +#include <event2/buffer.h> +#include <event2/listener.h> +#include <event2/util.h> +#include <event2/event.h> + +static const char MESSAGE[] = "Hello, World!\n"; + +static const int PORT = 9995; + +static void listener_cb(struct evconnlistener *, evutil_socket_t, + struct sockaddr *, int socklen, void *); +static void conn_writecb(struct bufferevent *, void *); +static void conn_eventcb(struct bufferevent *, short, void *); +static void signal_cb(evutil_socket_t, short, void *); + +int +main(int argc, char **argv) +{ + struct event_base *base; + struct evconnlistener *listener; + struct event *signal_event; + + struct sockaddr_in sin = {0}; +#ifdef _WIN32 + WSADATA wsa_data; + WSAStartup(0x0201, &wsa_data); +#endif + + base = event_base_new(); + if (!base) { + fprintf(stderr, "Could not initialize libevent!\n"); + return 1; + } + + sin.sin_family = AF_INET; + sin.sin_port = htons(PORT); + + listener = evconnlistener_new_bind(base, listener_cb, (void *)base, + LEV_OPT_REUSEABLE|LEV_OPT_CLOSE_ON_FREE, -1, + (struct sockaddr*)&sin, + sizeof(sin)); + + if (!listener) { + fprintf(stderr, "Could not create a listener!\n"); + return 1; + } + + signal_event = evsignal_new(base, SIGINT, signal_cb, (void *)base); + + if (!signal_event || event_add(signal_event, NULL)<0) { + fprintf(stderr, "Could not create/add a signal event!\n"); + return 1; + } + + event_base_dispatch(base); + + evconnlistener_free(listener); + event_free(signal_event); + event_base_free(base); + + printf("done\n"); + return 0; +} + +static void +listener_cb(struct evconnlistener *listener, evutil_socket_t fd, + struct sockaddr *sa, int socklen, void *user_data) +{ + struct event_base *base = user_data; + struct bufferevent *bev; + + bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE); + if (!bev) { + fprintf(stderr, "Error constructing bufferevent!"); + event_base_loopbreak(base); + return; + } + bufferevent_setcb(bev, NULL, conn_writecb, conn_eventcb, NULL); + bufferevent_enable(bev, EV_WRITE); + bufferevent_disable(bev, EV_READ); + + bufferevent_write(bev, MESSAGE, strlen(MESSAGE)); +} + +static void +conn_writecb(struct bufferevent *bev, void *user_data) +{ + struct evbuffer *output = bufferevent_get_output(bev); + if (evbuffer_get_length(output) == 0) { + printf("flushed answer\n"); + bufferevent_free(bev); + } +} + +static void +conn_eventcb(struct bufferevent *bev, short events, void *user_data) +{ + if (events & BEV_EVENT_EOF) { + printf("Connection closed.\n"); + } else if (events & BEV_EVENT_ERROR) { + printf("Got an error on the connection: %s\n", + strerror(errno));/*XXX win32*/ + } + /* None of the other events can happen here, since we haven't enabled + * timeouts */ + bufferevent_free(bev); +} + +static void +signal_cb(evutil_socket_t sig, short events, void *user_data) +{ + struct event_base *base = user_data; + struct timeval delay = { 2, 0 }; + + printf("Caught an interrupt signal; exiting cleanly in two seconds.\n"); + + event_base_loopexit(base, &delay); +} |