libEvent 使用

libevent介绍

http://blog.csdn.net/libaineu2004/article/details/47783263

libevent入门教程

http://www.cnblogs.com/xinsheng/p/3880567.html

libevent安装

http://www.cnblogs.com/kunhu/p/3632225.html

GCC:

./configure –prefix=/mnt/hgfs/share/build_libevent2.0.22

ARM:

./configure -prefix=/mnt/hgfs/share/build_libeventARM --host=arm-none-linux-gnueabi CC=arm-none-linux-gnueabi-gcc CXX=arm-none-linux-gnueabi-g++

以下代码出处：

http://www.it165.net/pro/html/201409/23110.html

TCP客户端代码

#include<sys/types.h>

#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<errno.h>
#include<unistd.h>
 
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
 
#include<event.h>
#include<event2/bufferevent.h>
#include<event2/buffer.h>
#include<event2/util.h>
 
 
 
 
int tcp_connect_server(const char* server_ip, int port);
 
 
void cmd_msg_cb(int fd, short events, void* arg);
void server_msg_cb(struct bufferevent* bev, void* arg);
void event_cb(struct bufferevent *bev, short event, void *arg);
 
int main(int argc, char** argv)
{
if( argc < 3 )
{
//两个参数依次是服务器端的IP地址、端口号
printf("please input 2 parameter
");
return -1;
}
 
struct event_base *base = event_base_new();
 
struct bufferevent* bev = bufferevent_socket_new(base, -1,
BEV_OPT_CLOSE_ON_FREE);
 
//监听终端输入事件
struct event* ev_cmd = event_new(base, STDIN_FILENO,
EV_READ | EV_PERSIST,
cmd_msg_cb, (void*)bev);
 
 
event_add(ev_cmd, NULL);
 
struct sockaddr_in server_addr;
 
memset(&server_addr, 0, sizeof(server_addr) );
 
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(atoi(argv[2]));
inet_aton(argv[1], &server_addr.sin_addr);
 
bufferevent_socket_connect(bev, (struct sockaddr *)&server_addr,
sizeof(server_addr));
 
 
bufferevent_setcb(bev, server_msg_cb, NULL, event_cb, (void*)ev_cmd);
bufferevent_enable(bev, EV_READ | EV_PERSIST);
 
 
 
event_base_dispatch(base);
 
printf("finished
");
return 0;
}
 
 
 
 
 
void cmd_msg_cb(int fd, short events, void* arg)
{
char msg[1024];
 
int ret = read(fd, msg, sizeof(msg));
if( ret < 0 )
{
perror("read fail ");
exit(1);
}
 
struct bufferevent* bev = (struct bufferevent*)arg;
 
//把终端的消息发送给服务器端
bufferevent_write(bev, msg, ret);
}
 
 
void server_msg_cb(struct bufferevent* bev, void* arg)
{
char msg[1024];
 
size_t len = bufferevent_read(bev, msg, sizeof(msg));
msg[len] = '';
 
printf("recv %s from server
", msg);
}
 
 
void event_cb(struct bufferevent *bev, short event, void *arg)
{
 
if (event & BEV_EVENT_EOF)
printf("connection closed
");
else if (event & BEV_EVENT_ERROR)
printf("some other error
");
else if( event & BEV_EVENT_CONNECTED)
{
printf("the client has connected to server
");
return ;
}
 
//这将自动close套接字和free读写缓冲区
bufferevent_free(bev);
 
struct event *ev = (struct event*)arg;
event_free(ev);

}

TCP服务端代码

#include<netinet/in.h>
#include<sys/socket.h>
#include<unistd.h>
 
#include<stdio.h>
#include<string.h>
 
#include<event.h>
#include<listener.h>
#include<bufferevent.h>
#include<thread.h>
 
 
void listener_cb(evconnlistener *listener, evutil_socket_t fd,
struct sockaddr *sock, int socklen, void *arg);
 
void socket_read_cb(bufferevent *bev, void *arg);
void socket_event_cb(bufferevent *bev, short events, void *arg);
 
int main()
{
//evthread_use_pthreads();//enable threads
 
struct sockaddr_in sin;
memset(&sin, 0, sizeof(struct sockaddr_in));
sin.sin_family = AF_INET;
sin.sin_port = htons(9999);
 
event_base *base = event_base_new();
evconnlistener *listener
= evconnlistener_new_bind(base, listener_cb, base,
LEV_OPT_REUSEABLE|LEV_OPT_CLOSE_ON_FREE,
10, (struct sockaddr*)&sin,
sizeof(struct sockaddr_in));
 
event_base_dispatch(base);
 
evconnlistener_free(listener);
event_base_free(base);
 
return 0;
}
 
 
//一个新客户端连接上服务器了
void listener_cb(evconnlistener *listener, evutil_socket_t fd,
struct sockaddr *sock, int socklen, void *arg)
{
printf("accept a client %d
", fd);
 
event_base *base = (event_base*)arg;
 
//为这个客户端分配一个bufferevent
bufferevent *bev =  bufferevent_socket_new(base, fd,
BEV_OPT_CLOSE_ON_FREE);
 
bufferevent_setcb(bev, socket_read_cb, NULL, socket_event_cb, NULL);
bufferevent_enable(bev, EV_READ | EV_PERSIST);
}
 
 
void socket_read_cb(bufferevent *bev, void *arg)
{
char msg[4096];
 
size_t len = bufferevent_read(bev, msg, sizeof(msg)-1 );
 
msg[len] = '';
printf("server read the data %s
", msg);
 
char reply[] = "I has read your data";
bufferevent_write(bev, reply, strlen(reply) );
}
 
 
void socket_event_cb(bufferevent *bev, short events, void *arg)
{
if (events & BEV_EVENT_EOF)
printf("connection closed
");
else if (events & BEV_EVENT_ERROR)
printf("some other error
");
 
//这将自动close套接字和free读写缓冲区
bufferevent_free(bev);
}

定时器

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <event.h>


struct self_tv
{
    struct event* evt;
    struct timeval tv;
};


void timeoutcallback(int /*fd*/, short /*event*/, void* arg)
{
    struct self_tv* st = (struct self_tv*)arg;
    //event_add(st->evt, &(st->tv));
    printf("timeoutcallback\n");
    return;
}


int main (int argc, char **argv) {
    struct event_base *base = event_base_new();
    /* 构造定时器 */
    struct self_tv* st = (struct self_tv*)malloc(sizeof(struct self_tv));
    st->tv.tv_sec = 1;
    st->tv.tv_usec = 0;
    st->evt = event_new(base, -1, EV_TIMEOUT|EV_PERSIST, timeoutcallback, st);
    event_add(st->evt, &st->tv);


    event_base_dispatch(base);
    event_base_free(base);
    
    return 0;
}