libevent server

#include <event2/event.h>
#include <event2/listener.h>
#include <string.h>
#include <iostream>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>

using namespace std;
#define SPORT 5001

void CLIENT_CB(evutil_socket_t sock, short which, void* arg)
{

    char szBuff[1024];
    int read_len = 0;
    event* pev = (event*)arg;
    
    memset(szBuff, 0x00, sizeof(szBuff));
    
    //超时处理也释放事件和关闭socket
    if(which&EV_TIMEOUT)
    {
        cout<<"timeout"<<endl;
        event_free(pev);
        evutil_closesocket(sock);
        return;
    }
    //由于添加的读取事件是持久性的，可以一直读取
    read_len = recv(sock, szBuff, sizeof(szBuff), 0);
    if (read_len <= 0)
    {
        cout<<"client has closed"<<endl;
        //当client断开时，则清理掉该连接的读事件
        event_free(pev);//源码中直接调用的是event_del函数
        evutil_closesocket(sock);//关闭客户端socket;
        return;
    }
    
    cout<<"read Buff:"<<szBuff<<endl;
    send(sock, "OK", 2, 0);
}
void LISTNE_CB(evutil_socket_t sock, short which, void *arg)
{
    cout << "listen_cb" << endl;
    event_base* pevbase = (event_base*)arg;
    
    char client_ip[16];
    sockaddr_in sock_client;
    socklen_t addr_len = sizeof(sock_client);
    memset(&sock_client, 0, sizeof(sock_client));
    memset(client_ip, 0x00, sizeof(client_ip));
    
    evutil_socket_t client_sock = accept(sock, (sockaddr*)&sock_client, &addr_len);
    if (client_sock <= 0)
    {
        cerr<<"accept error:"<<strerror(errno)<<endl;
        return ;
    }
    evutil_inet_ntop(AF_INET, &sock_client.sin_addr, client_ip, sizeof(client_ip));
    cout<<"client ip:"<<client_ip<<endl;
    
    //读取客户端数据
    event* pev = event_new(pevbase, client_sock, EV_READ|EV_PERSIST, CLIENT_CB, event_self_cbarg());
    if (!pev)
    {
        cerr<<"pev error"<<endl;
        return ;
    }
    //设置10s读取数据超时时间
    struct timeval tv={10, 0};
    event_add(pev, &tv);
}
int main()
{
    int res = 0;
    //创建libevent的上下文
    event_base * base = event_base_new();
    if (!base)
    {
        cerr << "event_base_new error!" << endl;
        return -1;
    }
    //创建socket
    evutil_socket_t sock = socket(AF_INET, SOCK_STREAM, 0);
    
    //设置地址复用和非阻塞
    evutil_make_listen_socket_reuseable(sock);
    evutil_make_socket_nonblocking(sock);
    //设置并绑定ip地址和端口
    sockaddr_in sin;
    memset(&sin, 0, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_port = htons(SPORT);
    res = bind(sock, (sockaddr*)&sin, sizeof(sockaddr_in));
    if (res != 0)
    {
        cerr<<"bind error:"<<strerror(errno)<<endl;
    }
    //监听
    listen(sock, 10);
    //开始接受连接事件，持久性，默认是水平触发
    event* pev = event_new(base, sock, EV_READ|EV_PERSIST, LISTNE_CB, base);
    event_add(pev, 0);
    //事件分发处理
    event_base_dispatch(base);
    event_base_free(base);
    evutil_closesocket(sock);
    return 0;
}