Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

Performance while overlaping windows on windows taskbar



  • Hi,
    I have a small app that recive udp packets and show the data on sevarl forms.

    I VERIFIED that the thread is running on different thread.

    I have performance issui that i cant explain.

    Im opening 3 ui form that do nothing.
    Im reciving the udp data and do nothing with the data.
    I printing the frame number that is send in data structure.
    I calaculte the diff between the frame numbers(should be one becuase it integer that incremant every cycle).

    When i open the app, every thing is ok.

    the problem
    **when the forms is minimized, and i go to the taskbar, i put the mouse cursor on the app icon.
    The forms is shown as small windows and i can move across the forms to choose one of the forms.
    When i do this, i loose lots of Udp packets
    Why? **


  • Lifetime Qt Champion

    Hi,

    Which version of Qt are you using ?
    On which version of Windows ?



  • @SGaist
    I tried 4.8 and 5.12.
    Windows 7.
    Both the same result.

    In additional to the post.
    I see that when go over any minimized program on the taskbar i start lose packets.



  • just a WAG, but check the settings in your windoze task manager. In there somewhere is a setting to balance CPU load between background and foreground tasks. See if adjusting it makes a difference. For a well written UDP listener it shouldn't matter but I don't know what your UDP service code looks like.



  • @Kent-Dorfman
    Its very simple app.
    Controler thread.
    Udp thread.

    I implemnted the basics to verify if it work.
    The Controler thread open udp thread,
    In the udp thread i use QUdpsocket with connect to readyread().
    The data arrive contunusly.

    Currenylt the ui do nothing, the Controler do nothing.

    When i will be infront of computer i will add the basic code.

    All the thread is opend with moveToThread().



  • Hi,
    @SGaist
    @Kent-Dorfman

    I tried to google "QUdpsocket priority",
    I got many result that discribe my problem but without soultion.

    Many peopele have the same problem.

    My felling is there is some problem. But i dont have enough knowledge to debug it.