Stack overflow from apparent infinite loop in Settings.Designer.vb

Question

I have an application that is going into an apparent infinite loop while setting up Settings, before the main window even loads. 

The error occurs in the Default method of MySettings, on the AddHandler statement. 

        Public Shared ReadOnly Property [Default]() As MySettings

            Get

                

#If _MyType = "WindowsForms" Then

               If Not addedHandler Then

                    SyncLock addedHandlerLockObject

                        If Not addedHandler Then

                            AddHandler My.Application.Shutdown, AddressOf AutoSaveSettings

                            addedHandler = True

                        End If

                    End SyncLock

                End If

#End If

                Return defaultInstance

            End Get

        End Property

The exception thrown is StackOverflowException, which clearly points to an infinite loop.

What is causing this? This is in Visual Studio 2008 Express, using .Net 3.5. I have not modified the above code nor do I intend to.

Answer 1

I'd guess that this isn't the actual problematic line, but rather the line where you overflow your stack.

Try opening up the call stack window in the debugger when this occurs, and seeing what is accessing MySettings.  My guess is that you're trying to access your settings for a property initialization routine somewhere, but calling it incorrectly, and causing the infinite loop.

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Reed Copsey, Jr. - http://reedcopsey.com

Answer 2

The call stack isn't helpful. I put a breakpoint on the bolded line and the first time it breaks, the only thing under the Default property in the stack is External Code.

Answer 3

From http://msdn.microsoft.com/en-us/library/a3694ts5.aspx:

 To display non-user code frames in the Call Stack window

   Right-click the Call Stack window and choose Show External Code

This will hopefully give you a better idea as to what is going on...

Best regards,
Johan Stenberg

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Microsoft Visual Studio