what is the best way to make a network app? multi-thread...heart-beating...



  • what is the best way to make a network app? multi-thread...heart-beating...
    i seems that there is no msg loop explicitly in main()...
    i want to read data from the server in a loop.

    is there any good example to create a thread and do this network thing(eg. heart-beating)?

    thank you!



  • Hi opengpu2,
    if you´re not tied to Qt have a look at boost::asio.



  • @opengpu2 said:

    what is the best way to make a network app? multi-thread...heart-beating...

    The right answer is: "There isn't the BEST way". It depends of your application feauters and requirements

    i seems that there is no msg loop explicitly in main()...
    i want to read data from the server in a loop.

    Qt usually prefers the Asynchronous approach but you can read from a socket with blocking API like QUdpSocket::readDatagram()

    is there any good example to create a thread and do this network thing(eg. heart-beating)?

    thank you!



  • Alternatively you can do threads and timers to sort of make your own loop.



  • yes, i don't want to use boost, and i want to use Qt.
    what is the API or demo that shows how to create a thread in Qt?
    and where should i create the timer? in the main thread or the new thread?
    and how to write the slot...thank you.
    and i think this timer method is sort of heart-beating, right?



  • Hi,

    as I said before you don't necessarily need a Thread for this work; Do you need to receive data from server or request data to the server?

    1. Receive Data (f.i. using a UDP socket)
    void ServerConnection::initSocket()
    {
        udpSocket = new QUdpSocket(this);
        udpSocket->bind(QHostAddress::LocalHost, 7755);
    
        connect(udpSocket, SIGNAL(readyRead()),
                this, SLOT(readPendingDatagrams()));
    }
    
    void ServerConnection::readPendingDatagrams()
    {
        while (udpSocket->hasPendingDatagrams()) {
            QByteArray datagram;
            datagram.resize(udpSocket->pendingDatagramSize());
            QHostAddress sender;
            quint16 senderPort;
    
            udpSocket->readDatagram(datagram.data(), datagram.size(), &sender, &senderPort);
    
            processTheDatagram(datagram);
        }
    }
    
    1. Request Data
    myTimer = new QTimer(this);
    connect(myTimer, &QTimer::timeout, this, &MyClass::requestData);
    
    void MyClass::requestData()
    {
       // Request data to the server
    }
    


  • thank you very much.
    i dont use QUdpSocket..i use my own network classes.
    right now i Tick the network io in the new thread. that's why i want to readData in msg loop, or heart-beating...

    maybe Tick the network io in the new thread, and use a timer as heart-beating in the main thread to readData() is a good method?



  • Hi,

    if you don't need to use high-speed communication or a lot of data you can do the whole processing (tick and readData) without threads



  • u mean i can put all this in the Times' slot()?



  • and if i want high-speed communication or a lot of data, what should i do ?
    it seems that u prefer not to create a new thread...why ? what is the disadvantage?



  • Hi,

    I think you should use something only if you really need it.
    Qt is designed to work in asynchronous mode so you can handle multiple source of data in a single-thread application.

    You should move to multi-threading when you need the handle long time processing or when you need to non block who's sending you data.



  • thank you
    i need the network io always Tick().
    and i also need readData from the server all the time...eg. in a msg loop in windows..
    but there seems no msg loop in Qt, so i wanted to use a timer as heart-beat to put readData in it.



  • Hi,

    do you need to read data only at tick?? In that case use the timeout signal to read data

    connect (timer, &QTimer::timeout, this, &MyClass::readData);
    
    void MyClass::readData() 
    {
       // Read from server
    }
    


  • yes,
    in addition, i want to put the network io Tick into a new thread.
    the readData() in the timeout slot.



  • and what is the normal way to create a new thread? (i want sth like ::CreateThread in window)


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.