Question

我创建了一个实现tcpsocket的select函数的类。（listenSock是TcpSocket的矢量 - 有效）我不明白为什么，但第二次选择被称为程序停止工作。

TCPSocket* MultipleTCPSocketsListener::listenToSocket(){
    //TODO: create local set for the select function (fd_set)
    fd_set set;
    FD_ZERO (&set);
    FD_SET (0, &set);

    //TODO: fill the set with file descriptors from the socket list using (FD_SET macro)
    for ( int i = 0; i < listenSock.size(); i++ )
    {
        FD_SET (listenSock.at(i)->getSock(), &set);
    }

    //TODO: perform the select
    int sel=select(sizeof(set)*8,&set,NULL,NULL,NULL);

    //TODO: check the returned value from the select to find the socket that is ready
     if (sel==-1) {
          perror("select failed");
          return NULL;
     }

    //TODO: if select return a valid socket return the matching TCPSocket object otherwise return NULL
     if (sel > 0)
     {
         for ( int i = 0; i < listenSock.size(); i++ )
         {
             if (FD_ISSET(listenSock.at(i)->getSock(), &set)) return  listenSock.at(i);
         }
     }
    return NULL;
}

Answer 1

FD_SET (0, &set);

没用。您指示select将stdin视为要监视的套接字之一。

在套接字中选择c ++不起作用

1 个答案: