Nullreference Exception in Normal Exceptionwindow (While Exploratiation)

Question

Hi,

I get sometimes the following Exception, while the Pex Exploratiation is running.

 

System.NullReferenceException: Object reference not set to an instance of an object.

   at Microsoft.ExtendedReflection.Interpretation.Reduction.Reducer.TryFilterInnerUpdates(Term baseCompound, ITermMap updates, Term index, Term& offset, ITermMap& filteredUpdates)

   at Microsoft.ExtendedReflection.Interpretation.Reduction.Reducer.TryReduceSelect(Term compound, Term index, Term& result)

   at Microsoft.ExtendedReflection.Interpretation.Impl.NormalizingTermManager.Select(Term compound, Term index)

   at Microsoft.ExtendedReflection.Interpretation.States.Impl.State.ReadSzArrayElement(Layout elementLayout, Term array, Term index)

   at Microsoft.ExtendedReflection.Interpretation.Interpreter.InstructionInterpreter.Ldelem(Layout layout, StackWidening widening)

   at Microsoft.ExtendedReflection.Monitoring.ThreadExecutionMonitorBase.Microsoft.ExtendedReflection.Monitoring.IThreadExecutionMonitor.Ldelem_Ref()

   at Microsoft.ExtendedReflection.Monitoring._InstructionsLDELEM.LDELEM_REF()

   at System.Array.$stub$IndexOf(Array , Object , Int32 , Int32 )

   at System.Collections.ArrayList.$stub$IndexOf(Object )

   at System.Windows.Forms.Control.ControlCollection.IndexOf(Control control)

   at System.Windows.Forms.Control.ControlCollection.GetChildIndex(Control child, Boolean throwException)

   at System.Windows.Forms.Control.ControlCollection.GetChildIndex(Control child)

   at System.Windows.Forms.Control.UpdateChildZOrder(Control ctl)

   at System.Windows.Forms.Control.WmCreate(Message& m)

   at System.Windows.Forms.Control.WndProc(Message& m)

   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)

   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)

   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Answer 1

Hi Alexander,

Is this related OOM happening at the same time? Is it possible to a (small) repro.

Thanks for your great feedback,
Peli

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Jonathan "Peli" de Halleux

Answer 2

>> Is this related OOM happening at the same time?
No, not as fare as I can tell.

>> Is it possible to a (small) repro.
I will see, if I can extract the Code responsible

Answer 3

This bug has been fixed in recent Pex releases.

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Nikolai Tillmann - Tell us how you use Pex