CmdPal: deadlock during theme reapply while dock bands initialize WinRT event subscriptions

Microsoft PowerToys version

0.99 / main

Installation method

Dev build in Visual Studio

Area(s) with issue?

Command Palette

Steps to reproduce

CmdPal can hang due to a deadlock in WinRT event subscription/unsubscription during concurrent UI theme reapply and dock-band background initialization.

Main thread blocked in:

• CommunityToolkit.WinUI.DispatcherQueueTimerExtensions.Timer_Tick
• ThemeServiceOnThemeChanged(object?, ThemeChangedEventArgs)
• remove
• ReaderWriterLockSlim.TryEnterWriteLockCore and nested TryEnterReadLockCore

Worker threads blocked in:

• InitializeFromList(IListPage)
• SlowInitializeProperties()
• InitializeProperties()
• create
• ReaderWriterLockSlim.TryEnterReadLockCore

🔫

CommunityToolkit.WinUI.Extensions.dll!CommunityToolkit.WinUI.DispatcherQueueTimerExtensions.Debounce(Microsoft.UI.Dispatching.DispatcherQueueTimer timer, System.Action action, System.TimeSpan interval, bool immediate) Line 36	C#	Non-user code. Decompiled symbols loaded (Embedded Source).

Main thread:

  	[Application execution paused, double-click to view all thread stacks]		Annotated Frame
 	System.Private.CoreLib.dll!System.Threading.WaitHandle.WaitOneNoCheck(int millisecondsTimeout, bool useTrivialWaits, object associatedObject, System.Diagnostics.Tracing.NativeRuntimeEventSource.WaitHandleWaitSourceMap waitSource)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.WaitHandle.WaitOne(int millisecondsTimeout)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.ReaderWriterLockSlim.WaitOnEvent(System.Threading.EventWaitHandle waitEvent, ref uint numWaiters, System.Threading.ReaderWriterLockSlim.TimeoutTracker timeout, System.Threading.ReaderWriterLockSlim.EnterLockType enterLockType)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.ReaderWriterLockSlim.TryEnterReadLockCore(System.Threading.ReaderWriterLockSlim.TimeoutTracker timeout)	Unknown	Non-user code. Skipped loading symbols.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSourceCache.Create(WinRT.IObjectReference obj, int index, System.WeakReference<object> state)	Unknown	Non-user code. Skipped loading symbols.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSource<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>>.Subscribe(Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object> handler)	Unknown	Non-user code. Skipped loading symbols.
>	CommunityToolkit.WinUI.Extensions.dll!CommunityToolkit.WinUI.DispatcherQueueTimerExtensions.Debounce(Microsoft.UI.Dispatching.DispatcherQueueTimer timer, System.Action action, System.TimeSpan interval, bool immediate) Line 36	C#	Non-user code. Decompiled symbols loaded (Embedded Source).
 	Microsoft.CmdPal.UI.ViewModels.dll!Microsoft.CmdPal.UI.ViewModels.AppearanceSettingsViewModel.ThemeServiceOnThemeChanged(object sender, Microsoft.CmdPal.UI.ViewModels.Services.ThemeChangedEventArgs e) Line 468	C#	Symbols loaded.
 	Microsoft.CmdPal.UI.dll!Microsoft.CmdPal.UI.Services.ThemeService.Reload() Line 207	C#	Symbols loaded.
 	CommunityToolkit.WinUI.Extensions.dll!CommunityToolkit.WinUI.DispatcherQueueTimerExtensions.Timer_Tick(object sender, object e) Line 50	C#	Non-user code. Decompiled symbols loaded (Embedded Source).
 	Microsoft.InteractiveExperiences.Projection.dll!WinRT._EventSource_global__Windows_Foundation_TypedEventHandler_global__Microsoft_UI_Dispatching_DispatcherQueueTimer__object_.EventState.GetEventInvoke.AnonymousMethod__1_0(Microsoft.UI.Dispatching.DispatcherQueueTimer sender, object args)	Unknown	Non-user code. Skipped loading symbols.
 	Microsoft.InteractiveExperiences.Projection.dll!WinRT.GenericTypeInstantiations.Windows_Foundation_TypedEventHandler_2_Microsoft_UI_Dispatching_DispatcherQueueTimer__object.Do_Abi_Invoke(nint thisPtr, nint sender, nint args)	Unknown	Non-user code. Skipped loading symbols.
 	[Native to Managed Transition]		Non-user code. Annotated Frame
 	[Managed to Native Transition]		Non-user code. Annotated Frame
 	System.Private.CoreLib.dll!System.Threading.WaitHandle.WaitOneNoCheck(int millisecondsTimeout, bool useTrivialWaits, object associatedObject, System.Diagnostics.Tracing.NativeRuntimeEventSource.WaitHandleWaitSourceMap waitSource)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.WaitHandle.WaitOne(int millisecondsTimeout)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.ReaderWriterLockSlim.WaitOnEvent(System.Threading.EventWaitHandle waitEvent, ref uint numWaiters, System.Threading.ReaderWriterLockSlim.TimeoutTracker timeout, System.Threading.ReaderWriterLockSlim.EnterLockType enterLockType)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.ReaderWriterLockSlim.TryEnterWriteLockCore(System.Threading.ReaderWriterLockSlim.TimeoutTracker timeout)	Unknown	Non-user code. Skipped loading symbols.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSourceCache.Remove(nint thisPtr, int index, System.WeakReference<object> state)	Unknown	Non-user code. Skipped loading symbols.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSourceState<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>>.Dispose(bool disposing)	Unknown	Non-user code. Skipped loading symbols.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSource<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>>.UnsubscribeFromNative(ABI.WinRT.Interop.EventSourceState<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>> state)	Unknown	Non-user code. Skipped loading symbols.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSource<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>>.Unsubscribe(Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object> handler)	Unknown	Non-user code. Cannot find or open the PDB file.
 	CommunityToolkit.WinUI.Extensions.dll!CommunityToolkit.WinUI.DispatcherQueueTimerExtensions.Timer_Tick(object sender, object e) Line 45	C#	Non-user code. Decompiled symbols loaded (Embedded Source).
 	Microsoft.InteractiveExperiences.Projection.dll!WinRT._EventSource_global__Windows_Foundation_TypedEventHandler_global__Microsoft_UI_Dispatching_DispatcherQueueTimer__object_.EventState.GetEventInvoke.AnonymousMethod__1_0(Microsoft.UI.Dispatching.DispatcherQueueTimer sender, object args)	Unknown	Non-user code. Skipped loading symbols.
 	Microsoft.InteractiveExperiences.Projection.dll!WinRT.GenericTypeInstantiations.Windows_Foundation_TypedEventHandler_2_Microsoft_UI_Dispatching_DispatcherQueueTimer__object.Do_Abi_Invoke(nint thisPtr, nint sender, nint args)	Unknown	Non-user code. Skipped loading symbols.
 	[Native to Managed Transition]		Non-user code. Annotated Frame
 	[Managed to Native Transition]		Non-user code. Annotated Frame
 	System.Private.CoreLib.dll!System.Threading.WaitHandle.WaitOneNoCheck(int millisecondsTimeout, bool useTrivialWaits, object associatedObject, System.Diagnostics.Tracing.NativeRuntimeEventSource.WaitHandleWaitSourceMap waitSource)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.WaitHandle.WaitOne(int millisecondsTimeout)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.ReaderWriterLockSlim.WaitOnEvent(System.Threading.EventWaitHandle waitEvent, ref uint numWaiters, System.Threading.ReaderWriterLockSlim.TimeoutTracker timeout, System.Threading.ReaderWriterLockSlim.EnterLockType enterLockType)	Unknown	Non-user code. Skipped loading symbols.
 	System.Private.CoreLib.dll!System.Threading.ReaderWriterLockSlim.TryEnterWriteLockCore(System.Threading.ReaderWriterLockSlim.TimeoutTracker timeout)	Unknown	Non-user code. Skipped loading symbols.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSourceCache.Remove(nint thisPtr, int index, System.WeakReference<object> state)	Unknown	Non-user code. Cannot find or open the PDB file.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSourceState<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>>.Dispose(bool disposing)	Unknown	Non-user code. Cannot find or open the PDB file.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSource<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>>.UnsubscribeFromNative(ABI.WinRT.Interop.EventSourceState<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>> state)	Unknown	Non-user code. Cannot find or open the PDB file.
 	WinRT.Runtime.dll!ABI.WinRT.Interop.EventSource<Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object>>.Unsubscribe(Windows.Foundation.TypedEventHandler<Microsoft.UI.Dispatching.DispatcherQueueTimer, object> handler)	Unknown	Non-user code. Cannot find or open the PDB file.
 	CommunityToolkit.WinUI.Extensions.dll!CommunityToolkit.WinUI.DispatcherQueueTimerExtensions.Timer_Tick(object sender, object e) Line 45	C#	Non-user code. Decompiled symbols loaded (Embedded Source).
 	Microsoft.InteractiveExperiences.Projection.dll!WinRT._EventSource_global__Windows_Foundation_TypedEventHandler_global__Microsoft_UI_Dispatching_DispatcherQueueTimer__object_.EventState.GetEventInvoke.AnonymousMethod__1_0(Microsoft.UI.Dispatching.DispatcherQueueTimer sender, object args)	Unknown	Non-user code. Skipped loading symbols.
 	Microsoft.InteractiveExperiences.Projection.dll!WinRT.GenericTypeInstantiations.Windows_Foundation_TypedEventHandler_2_Microsoft_UI_Dispatching_DispatcherQueueTimer__object.Do_Abi_Invoke(nint thisPtr, nint sender, nint args)	Unknown	Non-user code. Skipped loading symbols.
 	[Native to Managed Transition]		Non-user code. Annotated Frame
 	[Managed to Native Transition]		Non-user code. Annotated Frame
 	Microsoft.WinUI.dll!ABI.Microsoft.UI.Xaml.IApplicationStaticsMethods.Start(WinRT.IObjectReference _obj, Microsoft.UI.Xaml.ApplicationInitializationCallback callback)	Unknown	Non-user code. Skipped loading symbols.
 	Microsoft.WinUI.dll!Microsoft.UI.Xaml.Application.Start(Microsoft.UI.Xaml.ApplicationInitializationCallback callback)	Unknown	Non-user code. Skipped loading symbols.
 	Microsoft.CmdPal.UI.dll!Microsoft.CmdPal.UI.Program.Main(string[] args) Line 94	C#	Symbols loaded.

Worker thread:

System.Private.CoreLib.dll!System.Threading.WaitHandle.WaitOneNoCheck(int millisecondsTimeout, bool useTrivialWaits, object associatedObject, System.Diagnostics.Tracing.NativeRuntimeEventSource.WaitHandleWaitSourceMap waitSource)	Unknown	Non-user code. Skipped loading symbols.
System.Private.CoreLib.dll!System.Threading.WaitHandle.WaitOne(int millisecondsTimeout)	Unknown	Non-user code. Skipped loading symbols.
System.Private.CoreLib.dll!System.Threading.ReaderWriterLockSlim.WaitOnEvent(System.Threading.EventWaitHandle waitEvent, ref uint numWaiters, System.Threading.ReaderWriterLockSlim.TimeoutTracker timeout, System.Threading.ReaderWriterLockSlim.EnterLockType enterLockType)	Unknown	Non-user code. Skipped loading symbols.
System.Private.CoreLib.dll!System.Threading.ReaderWriterLockSlim.TryEnterReadLockCore(System.Threading.ReaderWriterLockSlim.TimeoutTracker timeout)	Unknown	Non-user code. Skipped loading symbols.
WinRT.Runtime.dll!ABI.WinRT.Interop.EventSourceCache.Create(WinRT.IObjectReference obj, int index, System.WeakReference<object> state)	Unknown	Non-user code. Skipped loading symbols.
WinRT.Runtime.dll!ABI.WinRT.Interop.EventSource<Windows.Foundation.TypedEventHandler<object, Microsoft.CommandPalette.Extensions.IPropChangedEventArgs>>.Subscribe(Windows.Foundation.TypedEventHandler<object, Microsoft.CommandPalette.Extensions.IPropChangedEventArgs> handler)	Unknown	Non-user code. Skipped loading symbols.
Microsoft.CommandPalette.Extensions.Toolkit.dll!ABI.Microsoft.CommandPalette.Extensions.INotifyPropChanged.Microsoft.CommandPalette.Extensions.INotifyPropChanged.PropChanged.add(Windows.Foundation.TypedEventHandler<object, Microsoft.CommandPalette.Extensions.IPropChangedEventArgs> value) Line 6840	C#	Symbols loaded.
Microsoft.CmdPal.UI.ViewModels.dll!Microsoft.CmdPal.UI.ViewModels.CommandViewModel.InitializeProperties() Line 99	C#	Symbols loaded.
Microsoft.CmdPal.UI.ViewModels.dll!Microsoft.CmdPal.UI.ViewModels.CommandItemViewModel.InitializeProperties() Line 174	C#	Symbols loaded.
Microsoft.CmdPal.UI.ViewModels.dll!Microsoft.CmdPal.UI.ViewModels.CommandItemViewModel.SlowInitializeProperties() Line 216	C#	Symbols loaded.
Microsoft.CmdPal.UI.ViewModels.dll!Microsoft.CmdPal.UI.ViewModels.Dock.DockBandViewModel.InitializeFromList(Microsoft.CommandPalette.Extensions.IListPage list) Line 190	C#	Symbols loaded.
Microsoft.CmdPal.UI.ViewModels.dll!Microsoft.CmdPal.UI.ViewModels.Dock.DockBandViewModel.InitializeProperties() Line 212	C#	Symbols loaded.
Microsoft.CmdPal.UI.ViewModels.dll!Microsoft.CmdPal.UI.ViewModels.ExtensionObjectViewModel.SafeInitializePropertiesSynchronous() Line 102	C#	Symbols loaded.
Microsoft.CmdPal.UI.ViewModels.dll!Microsoft.CmdPal.UI.ViewModels.Dock.DockViewModel.SetupBands.AnonymousMethod__1() Line 137	C#	Symbols loaded.

✔️ Expected Behavior

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❌ Actual Behavior

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Upload Bug Report ZIP-file

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Additional Information

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Other Software

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