[vtkusers] get bounds an actor in thread

[yas ---]

I write follow code  in  a thread.

void updateHaptics(void)
{

while(simulationRunning )
     {
   double bounds[6];
   toolactor->Getbounds(bounds);

       }
simulationRunning=false;

    }

    // exit haptics thread
    simulationFinished = true;

}
beacuse of use from   Getbounds function ,after running ,this is follow
error:
Error: in VTK\Filtering\vtkExcutive in line 783


vtkErrorMacro(<< method << " invoked during another request.  "
                    "Returning failure to algorithm "
                    << this->Algorithm->GetClassName(
) << "("
                    << this->Algorithm << ").");
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20130416/88957aff/attachment.htm>