Unhandled System.Threading.Tasks.TaskCanceledException when exiting application

[DaveNay]

Library version

2.5.1

Expected behaviour

Properly handle TaskCanceledExceptions.

Actual behaviour

Throws an unhandled exception when exiting application.

Steps to reproduce behaviour

• Open sample application using Visual Studio 2019 16.2.x
• Run application with debugging
• Close application

Unhandled exception does not occur every time, may need to repeat (perhaps as many as 12-15 times)

Code to reproduce behaviour

Sample application included.

ToastNotificationTest.zip

Questions

This only seems to happen with Visual Studio 2019 16.2.0 or higher. I did not see this on earlier viersions of vs2019 or vs2017.

[DaveNay]

Exception details...

  HResult=0x8013153B
  Message=A task was canceled.
  Source=mscorlib
  StackTrace:
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Windows.Threading.DispatcherOperation.Wait(TimeSpan timeout)
   at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherOperation operation, CancellationToken cancellationToken, TimeSpan timeout)
   at System.Windows.Threading.Dispatcher.Invoke[TResult](Func`1 callback, DispatcherPriority priority, CancellationToken cancellationToken, TimeSpan timeout)
   at System.Windows.Threading.Dispatcher.Invoke[TResult](Func`1 callback)
   at Microsoft.VisualStudio.DesignTools.WpfTap.WpfVisualTreeService.Properties.PropertyService.GetPropertyValuesChainInternal(Int64 instanceHandle, Object targetObject)
   at Microsoft.VisualStudio.DesignTools.WpfTap.WpfVisualTreeService.Properties.PropertyService.HandlePropertyChainRequest(PropertiesRequestInfo requestInfo)
   at Microsoft.VisualStudio.DesignTools.WpfTap.Networking.ProtocolHandler.HandleMessage[TMessage,TReply](Func`2 callback, Message request)
   at Microsoft.VisualStudio.DesignTools.WpfTap.Networking.ProtocolHandler.<>c__DisplayClass27_0`2.<RegisterMessageObserver>b__0(Message message)
   at Microsoft.VisualStudio.DesignTools.WpfTap.Networking.ProtocolHandler.ProcessInboundMessage(Message message)
   at Microsoft.VisualStudio.DesignTools.WpfTap.Networking.ProtocolHandler.<>c__DisplayClass40_0.<OnMessageReceived>b__0()
   at Microsoft.VisualStudio.DesignTools.WpfTap.Networking.ProtocolHandler.WaitableActionsList.<>c__DisplayClass8_0.<AddAndSignal>b__0(Boolean isCancelled)
   at Microsoft.VisualStudio.DesignTools.WpfTap.Networking.ProtocolHandler.ActionThread(Object list)
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart(Object obj)

[DaveNay]

This appears to likely be a VS2019 16.2 issue.

https://developercommunity.visualstudio.com/content/problem/684087/systemthreadingtaskstaskcanceledexception-thrown-w.html