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If an update has already been queued for processing (but not yet completed), simply skip queuing another update.
Keboo
approved these changes
Mar 25, 2026
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Fixes #4003
This PR fixes (or at least drastically improves) the memory leak mentioned in the issue. Basically, the code was blindly queuing new updates of the attached property on every layout update. When resizing a window or doing something else causing a lot of layout events, this would "congest" the message pump with essentially the same lambda.
This PR introduces a flag
_uiUpdateInProgresswhich is set once an update is being queued, and cleared once an update has finished. If a layout change happens in between, it is simply ignored.The below shows the memory usage captured in the Visual Studio diagnostics tools before/after the fix. The reproduction step was to open the app (from the linked issue), and repeatedly resize the window.
Memory usage before the fix (continuous growth, insane number of GC calls, no drop-down to "normal" after resizing finishes):
Memory usage after the fix (still growth which is expected, much fewer GC calls, and a drop-down to "normal" after resizing finishes):
