Deadlock of UI thread and background render thread

[hamster620]

Sometimes the UI thread may be blocked because of deadlock of UI thread and background render thread. Both threads are trying to access Dispatcher and ServerCompositor which lock Dispatcher.InstanceLock and ServerCompositor._lock in different order.

Stack trace of UI thread:

Stack trace of background render thread:

To Reproduce In our side, ServerCompositor is called by closing ToolTip by posting an action to Dispatcher.

Expected behavior No deadlock, at least not to block the UI thread.

Screenshots N/A

Desktop (please complete the following information):

• OS: macOS 13.4.1
• Version: 11.0.0