1、作用:
- 从外面看它就是一个缓冲区,可以与socket绑定
- 内部由输入与输出缓冲区组成
- 每一个socket对应一个bufferevent
- 当socket有事件触发时,可以设置回调函数
2、编译和安装
下载源码
生成makefile
./configure --prefix=/usr/lib/libevent
编译
make
安装
make install
配置环境变量
vim ~/.bashrc
export PKG_CONFIG_PATH=/usr/lib/libevent/lib/pkgconfig:$PKG_CONFIG_PATH
export LD_LIBRARY_PATH=/usr/lib/libevent/lib:$LD_LIBRARY_PATH
source ~/.bashrc
检查
$ pkg-config --libs --cflags libevent
-I/usr/lib/libevent/include -L/usr/lib/libevent/lib -levent
3、基础API
event_base_new
event_base_dispatch
event_new
event_add
event_del
event_free
evconnlistener_new_bind()
struct evconnlistenner* evconnlistener_new_bind(struct event_base *base,
evconnlistener_cb cb,
void *ptr,
unsigned flags,
int backlog,
const struct sockaddr* sa,
)
4、程序
#include<iostream>
#include<event2/listener.h>
#include<event2/bufferevent.h>
#include<event2/buffer.h>
#include<arpa/inet.h>
#define PORT 8111
void on_read_cb(struct bufferevent* bev, void* ctx)
{
struct evbuffer *input = NULL;
struct evbuffer *output = NULL;
input = bufferevent_get_input(bev);
output = bufferevent_get_output(bev);
evbuffer_add_buffer(output, input);
}
void on_accept_cb(struct evconnlistener* listener,
evutil_socket_t fd,
struct sockaddr* addr,
int socklen,
void* ctx)
{
struct event_base* base = NULL;
struct bufferevent* bev = NULL;
base = evconnlistener_get_base(listener);
bev = bufferevent_socket_new(base, fd, 0);
bufferevent_enable(bev, EV_READ | EV_WRITE);
bufferevent_setcb(bev, on_read_cb, NULL, NULL, NULL);
}
int main() {
struct sockaddr_in serveraddr;
struct event_base* base = NULL;
struct evconnlistener* listener;
base = event_base_new();
serveraddr.sin_family = AF_INET;
serveraddr.sin_port = htons(PORT);
serveraddr.sin_addr.s_addr = INADDR_ANY;
listener = evconnlistener_new_bind(base,
on_accept_cb,
NULL,
LEV_OPT_REUSEABLE,
10,
(struct sockaddr*)&serveraddr,
sizeof(serveraddr));
event_base_dispatch(base);
return 0;
}
g++ -g -o tcpserver tcp_server.cpp `pkg-config --libs --cflags libevent`
检查服务是否已经启动
netstat -ntpl | grep 8111
5、测试
工具:sourceforge.net/projects/so… 用工具代表客户端: