QTcpSocket 遇到的問題！

//當有用戶斷開連接的時候
void NewConnectThread::slotUesrDisconnected()
{ 
    QByteArray data="report";
    if(tcpSocket->write(data)==-1){
        qDebug("userDisconnect");
        context->serverFrame->appendMessageTextBrowser(tcpSocket->peerAddress().toString()+
                                                   QString::number(tcpSocket->peerPort())+" 斷開連接");
        disconnect(tcpSocket,SIGNAL(readyRead()),this,SLOT(readMessage()));
        disconnect(timer,SIGNAL(timeout()),this,SLOT(slotUesrDisconnected()));
        for(int i=0;i<context->sender.size();i++)
        {
            if((context->sender.at(i)->peerAddress()!=tcpSocket->peerAddress()) ||
                (context->sender.at(i)->peerPort()!=tcpSocket->peerPort()))
            {
                mutex.lock();
                context->sender.removeAt(i);
                mutex.unlock();
            }

        }
        this->exit();
    }
}

tcpSocket->失敗時返回-1大家都知道，但是這是對tcpSocket有什麼影響，爲什麼我下面再次調用tcpSocket->peerAddress().toString()+tcpSocket->peerPort())顯示的是0？

說明：這個槽函數連接的是timeout();時間設了3秒。