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

QAccessible unusably slow



  • Hi,

    I am encountering a severe issue in our application using Qt 5.42 on Windows.

    As soon as a touch enabled device is attached and the Tablet-PC-Service is running on Windows, the QAccessible becomes active and causes massive performance issues like having to wait for about 30 seconds when clicking on an treeview item.
    I have attached Vtune to figure out where the time is spend and it showed that about 16 seconds were spend in QAccessible::uniqueId, which was called about 94k times and another 18 seconds were spend in QHashData::nextNode, which was called by QAccessible::uniqueId and was called about 1.4 billion times.

    Disabling the Tablet-PC-Service and therefore disabling QAccessible fixed this slowdown but of course it not something we can do. So is there a way in Qt do disable the QAccessible stuff in our application?

    Kind regards
    Michael


  • Lifetime Qt Champion

    Hi and welcome to devnet,

    Since it looks like a bug, I'd recommend bringing this to the interest mailing list. You should also have a look at the bug report system



  • @SGaist Ok, thanks, I will do so.


  • Lifetime Qt Champion

    If there's a bug report related to that matter, don't forget to share it here so others will be able to find it more easily


Log in to reply