QUdpSocket hasPendingDatagrams()

[mbjerkne]

I am setting up a QUdpSocket and connecting the readyRead() signal to my readDatagrams() method, however when I get into the method and check the socket with hasPendingDatagrams() it never enters my loop, i.e:

void Listener::readDatagrams()
{
   while ( m_aSocket->hasPendingDatagrams() )
   {
      // Never gets here
   }
}

void Listener::readDatagrams()
{
   while ( m_aSocket->hasPendingDatagrams() )
   {
      // Never gets here
   }
}

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however, if i skip that loop and just read a datagram from the socket I get my data:

QByteArray datagram;
    datagram.resize(m_aSocket->pendingDatagramSize());
    QHostAddress sender;
    quint16 senderPort;
 
    m_aSocket->readDatagram(datagram.data(), datagram.size(), &sender, &senderPort);
 
    if ( datagram.size() > 0 )
    {
      // Gets here without loop
    }

QByteArray datagram;
    datagram.resize(m_aSocket->pendingDatagramSize());
    QHostAddress sender;
    quint16 senderPort;

    m_aSocket->readDatagram(datagram.data(), datagram.size(), &sender, &senderPort);

    if ( datagram.size() > 0 )
    {
      // Gets here without loop
    }

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Can anyone help out?

[vratojr]

Please,post how and when you call the readDatagram function.

[mbjerkne]

ControlsListener::ControlsListener(int nPort)
{
  m_nPort = nPort;
  m_aSocket = new QUdpSocket();
  if ( !m_aSocket->bind(m_nPort) )
  {
    std::cout << "Could not bind udp socket" << std::endl;
  }
  else
  {
    std::cout << "Successfully created udp socket on port " << nPort << std::endl;
  }
  connect(m_aSocket,SIGNAL(readyRead()),
    this, SLOT(readPendingDatagrams()));
}
 
ControlsListener::~ControlsListener()
{
  delete m_aSocket;
}
 
void ControlsListener::readPendingDatagrams()
{
 
  //std::cout << "readPendingDatagrams" << std::endl;
  //while ( m_aSocket->hasPendingDatagrams() )
 // {
    QByteArray datagram;
    datagram.resize(m_aSocket->pendingDatagramSize());
    QHostAddress sender;
    quint16 senderPort;
 
    m_aSocket->readDatagram(datagram.data(), datagram.size(), &sender, &senderPort);
 
    if ( datagram.size() > 0 )
    {
    double * dData = (double*)datagram.data();
 
    ByteSwap5(*dData);
 
    double dValue = *dData;
 
    QString sValue = QString("%1").arg(dValue);
    emit messageReceived(sValue);
    }
  //}
}

ControlsListener::ControlsListener(int nPort)
{
  m_nPort = nPort;
  m_aSocket = new QUdpSocket();
  if ( !m_aSocket->bind(m_nPort) )
  {
    std::cout << "Could not bind udp socket" << std::endl;
  }
  else
  {
    std::cout << "Successfully created udp socket on port " << nPort << std::endl;
  }
  connect(m_aSocket,SIGNAL(readyRead()),
    this, SLOT(readPendingDatagrams()));
}

ControlsListener::~ControlsListener()
{
  delete m_aSocket;
}

void ControlsListener::readPendingDatagrams()
{

  //std::cout << "readPendingDatagrams" << std::endl;
  //while ( m_aSocket->hasPendingDatagrams() )
 // {
    QByteArray datagram;
    datagram.resize(m_aSocket->pendingDatagramSize());
    QHostAddress sender;
    quint16 senderPort;

    m_aSocket->readDatagram(datagram.data(), datagram.size(), &sender, &senderPort);

    if ( datagram.size() > 0 )
    {
    double * dData = (double*)datagram.data();

    ByteSwap5(*dData);

    double dValue = *dData;

    QString sValue = QString("%1").arg(dValue);
    emit messageReceived(sValue);
    }
  //}
}

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This is the code for the whole listener. I have the while loop commented out right now, but if I uncomment the loop it never enters it. If I uncomment the std::cout << "readPendingDatagrams" << std::end; it gets printed a whole lot, but nothing ever enters the loop.

[jacek]

If I uncomment the std::cout << "readPendingDatagrams" << std::end; it gets printed a whole lot, but nothing ever enters the loop.

Then maybe it's one of these bugs:
http://www.trolltech.com/developer/t...entry&id=86944
http://www.trolltech.com/developer/t...ntry&id=104325