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  1. Qt
  2. QTBUG-46865

QAccessible::uniqueId causes massive slowdowns

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    • Platform/s:
      Windows

      Description

      As soon as a touch enabled device is attached and the Tablet-PC-Service is running on Windows 7 (same with Windows 8 but the service is named differently) , the QAccessible becomes active and can cause 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 in my case 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 in Windows and therefore disabling QAccessible fixes this slowdown.

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            Assignee:
            frederik Frederik Gladhorn
            Reporter:
            Serendipity Michael Nikelsky
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              Dates

              Created:
              Updated:

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