[Qt QUdpSocket] 짧은 시간동안 메시지 300개중 180여개만 받아지는데 왜 그런거죠?

 
void slotUdpFunc()
{
    QByteArray readBlock;
 
    unsigned short int printData;
    int msgIDShift[2] = {0, 8};
    int msgIDMask[2] = {0xff, 0xff};
 
    while(udpSocket.hasPendingDatagrams())
    {
        int size =  udpSocket.pendingDatagramSize();
        printf("The size of message received by HC : [%d]\n", size);
        readBlock.resize(size);
        udpSocket.readDatagram(recvData, sizeof(recvData));
 
        msgFlag = processBit.ExtractMsg(recvData, printData, 6, 2, msgIDShift, msgIDMask);    //MessageID
        diverMsg(msgFlag, recvData);
 
        printf("count is %d\n\n", ++count);
    }
}