Server not reading

For some reason this server is not reading

Code:

ClientThread::ClientThread(int socketDescriptor, QTextBrowser * textBrowser)
{
  _socketDescriptor = socketDescriptor;
  _textBrowser = textBrowser;
  run();
}
 
 
void ClientThread::run()
{  
  dataIn = "";
  tcpSocket = new QTcpSocket();
  if(!tcpSocket->setSocketDescriptor(_socketDescriptor)){
    _textBrowser->append("Error in the connection");
    exit();
  }
  _textBrowser->append("Client successfully connected");
  connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(readData()));
  exec();
}
 
 
void ClientThread::readData()
{
  dataIn=(tcpSocket->readAll());
  _textBrowser->append("Hi");
  _textBrowser->append(dataIn);
}

Suggestions !!!