libevent编译与安装
libevent官网
wget -c addr --no-check-certificate
./configure --prefix=/usr/local/libevent
make -j 8
make install#include <event2/listener.h>
#include <event2/bufferevent.h>
#include <event2/buffer.h>
#include <event2/thread.h>#include <arpa/inet.h>#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>static void
echo_read_cb(struct bufferevent *bev, void *ctx)
{/* 获取bufferevent中的读和写的指针 *//* This callback is invoked when there is data to read on bev. */struct evbuffer *input = bufferevent_get_input(bev);struct evbuffer *output = bufferevent_get_output(bev);/* 把读入的数据全部复制到写内存中 *//* Copy all the data from the input buffer to the output buffer. */evbuffer_add_buffer(output, input);
}static void echo_event_cb(struct bufferevent *bev, short events, void *ctx)
{if (events & BEV_EVENT_ERROR)perror("Error from bufferevent");if (events & (BEV_EVENT_EOF | BEV_EVENT_ERROR)) {bufferevent_free(bev);}
}static void accept_conn_cb(struct evconnlistener *listener,evutil_socket_t fd, struct sockaddr *address, int socklen,void *ctx)
{/* 初始化一个bufferevent用于数据的写入和读取，首先需要从Listerner中获取event_base *//* We got a new connection! Set up a bufferevent for it. */struct event_base *base = evconnlistener_get_base(listener);struct bufferevent *bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);/*设置buferevent的回调函数，这里设置了读和事件的回调函数*/bufferevent_setcb(bev, echo_read_cb, NULL, echo_event_cb, NULL);/* 启用该bufevent写和读 */bufferevent_enable(bev, EV_READ|EV_WRITE);
}static void
accept_error_cb(struct evconnlistener *listener, void *ctx)
{struct event_base *base = evconnlistener_get_base(listener);int err = EVUTIL_SOCKET_ERROR();fprintf(stderr, "Got an error %d (%s) on the listener. ""Shutting down.\n", err, evutil_socket_error_to_string(err));event_base_loopexit(base, NULL);
}int
main(int argc, char **argv)
{struct event_base *base;struct evconnlistener *listener;struct sockaddr_in sin;int port = 8111;/*if (argc > 1) {port = atoi(argv[1]);}if (port<=0 || port>65535) {puts("Invalid port");return 1;}*///use threads//evthread_use_pthreads();base = event_base_new(); /* 初始化event_base */if (!base) {puts("Couldn't open event base");return 1;}/*初始化绑定地址*//*Clear the sockaddr before using it, * in case there are extra platform-specific fields * that can mess us up.*/memset(&sin, 0, sizeof(sin));/*This is an INET address */sin.sin_family = AF_INET;/*Listen on 0.0.0.0*/sin.sin_addr.s_addr = INADDR_ANY;/*Listen on the given port.*/sin.sin_port = htons(port);/* 初始化evconnlistener(绑定地址、设置回调函数以及连接属性) */listener = evconnlistener_new_bind(base, accept_conn_cb, NULL, LEV_OPT_CLOSE_ON_FREE|LEV_OPT_REUSEABLE, -1,(struct sockaddr*)&sin, sizeof(sin));if (!listener) {perror("Couldn't create listener");return 1;}/* 设置Listen错误回调函数 */evconnlistener_set_error_cb(listener, accept_error_cb);/* 开始accept进入循环 */event_base_dispatch(base);return 0;
}