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  1. Qt
  2. QTBUG-68989

Qt Quick does not rate limit on macOS 10.14 when using the threaded render loop

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Details

    • Bug
    • Resolution: Done
    • P1: Critical
    • None
    • 5.6, 5.9, 5.11
    • Quick: SceneGraph
    • None
    • macOS

    Description

       Animations run at 200% speed (at least) with corresponding increased CPU usage.

      This happens when using layer-backed QWindow/QNSView, which is reported to be the default on 10.14 Mojave, and which is also enabled for the Qt dev branch. To reproduce elsewhere set QT_MAC_WANTS_LAYER=1.

      We're investigating the scope for this. It can bee seen in at least:

      • examples/quick/shadereffects
      • examples/quick/animation

      Possible solutions/workarounds:

      • Use the basic render loop, in combination with CVDisplayLink-driven updates.
      • Fix the threaded render loop

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          relates to

          Task - A task that needs to be done. QTBUG-68891 macOS 10.14 Mojave Support

          • P1: Critical - Urgent and Important, will STOP the release if matched with set FixVersion field. This includes regressions from the last version that are not edge cases; Data loss; Build issues; All but the most unlikely crashes/lockups/hanging; Serious usability issues and embarrassing bugs & Bugs critical to a deliverable. This is the highest possible priority for requirements.
          • Closed
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              vestbo Tor Arne Vestbø
              sorvig Morten Sørvig
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              Dates

                Created:
                Updated:
                Resolved:

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