socket select代码

做多了windows，发现多select模式是那么的陌生，当想用心挖掘一下ACE::select的封装的时候，才发现自己几乎写不出一个完整的select模式示例，这其实是我一直没有重视过这个东西，现在细细分析来，发现，它要比我以往在处理类似问题的时候处理的更为简单。

    WSAData    wd;
    WSAStartup(MAKEWORD(2,2),&wd);
    SOCKET    sock    = socket(AF_INET,SOCK_STREAM,0);
    sockaddr_in    saddr;
    saddr.sin_family    = AF_INET;
    saddr.sin_addr.s_addr    = inet_addr("127.0.0.1");
    saddr.sin_port    = htons(2350);
    bind(sock,(SOCKADDR*)&saddr,sizeof(saddr));
    listen(sock,5);

    SOCKET    sk2        = socket(AF_INET,SOCK_STREAM,0);
    sockaddr_in    saddr2;
    saddr2.sin_family    = AF_INET;
    saddr2.sin_addr.s_addr    = inet_addr("127.0.0.1");
    saddr2.sin_port    = htons(2340);
    bind(sk2,(SOCKADDR*)&saddr2,sizeof(saddr2));
    listen(sk2,5);

    fd_set    rfd;        //read fd
    fd_set    bkfd;        //fdbake
    //fd_set    wfd;        //write fd
    //fd_set    etfd;        //except fd
    SOCKET    sac    = INVALID_SOCKET;
    SOCKET    sac2    = INVALID_SOCKET;

    FD_ZERO(&bkfd);
    FD_SET(sock,&bkfd);
    FD_SET(sk2,&bkfd);
    while(true)
    ...{
        memcpy(&rfd,&bkfd,sizeof(bkfd));
        int    sret    = select(0,&rfd,NULL,NULL,NULL);
        cout<<"sret:"<<sret<<endl;
        if( ! (sret > 0) )
        ...{
            cout<<"lasterror:"<<WSAGetLastError()<<endl;
            //break;
        }
        if (FD_ISSET(sock,&rfd))
        ...{
            closesocket(sac);
            int    len    = sizeof(saddr);
            sac    = accept(sock,(SOCKADDR*)&saddr,&len);
            FD_SET(sac,&bkfd);
        }
        else if (FD_ISSET(sk2,&rfd))
        ...{
            closesocket(sac2);
            int    len    = sizeof(saddr2);
            sac2    = accept(sk2,(SOCKADDR*)&saddr2,&len);
            FD_SET(sac2,&bkfd);
        }
        else if (FD_ISSET(sac,&rfd))
        ...{
            char    buf[1024];
            int    len = recv(sac,buf,1024,0);
            if(!(len > 0))
            ...{
                closesocket((sac));
                cout<<"close a socket"<<endl;
                FD_CLR(sac,&bkfd);
            }
            else
            ...{
                buf[len]    = 0;
                cout<<"recv:"<<buf<<endl;
            }
        }
        else if (FD_ISSET(sac2,&rfd))
        ...{
            char    buf[1024];
            int    len = recv(sac2,buf,1024,0);
            if (len <= 0)
            ...{
                closesocket(sac2);
                cout<<"close a socket"<<endl;
                FD_CLR(sac,&bkfd);
            }
            else
            ...{
                buf[len]    = 0;
                cout<<"recv:"<<buf<<endl;
            }
        }
    }
    WSACleanup();
    return 0;

 现在我感觉到，如果想做轻量级的多sock或者异步模式，select是个不错的选择。