# Crash SEGV at vtkCylinderSource::Update()
**URL:** https://discourse.vtk.org/t/crash-segv-at-vtkcylindersource-update/8517
**Category:** Support
**Created:** [May 17, 2022, 6:05pm UTC](https://discourse.vtk.org/t/crash-segv-at-vtkcylindersource-update/8517 "2022-05-17T18:05:37Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@sheran.vaz](https://discourse.vtk.org/u/sheran.vaz)
#### Post date: [May 17, 2022, 6:05pm UTC](https://discourse.vtk.org/t/crash-segv-at-vtkcylindersource-update/8517/1 "2022-05-17T18:05:37Z")
Trying to create a VTK polydata using below code snippet
vtkSmartPointer spC=vtkSmartPointer::New();
spC-\>SetHeight(rodLen);
spC-\>SetCenter(0,0,0);
spC-\>SetRadius(rodRadius);
spC-\>Update(); \<----- It crashes here
The above code snippet works fine when I call it in main(). The same crashes at Update() when I put it in the constructor of a globally initialized object.
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### Author:  [@sheran.vaz](https://discourse.vtk.org/u/sheran.vaz)
#### Post date: [May 17, 2022, 6:07pm UTC](https://discourse.vtk.org/t/crash-segv-at-vtkcylindersource-update/8517/2 "2022-05-17T18:07:22Z")
Stack trace looks as below
Thread #1 unnamed (Suspended : Signal : SIGSEGV:Segmentation fault)
vtkCylinderSource::RequestData() at string:1,508 0x50a79ed0ea
vtkExecutive::CallAlgorithm() at string:1,508 0x50a7d3e752
vtkStreamingDemandDrivenPipeline::ProcessRequest() at string:1,508 0x50a7d4470c
vtkDemandDrivenPipeline::UpdateDataObject() at string:1,508 0x50a7d3a0de
vtkDemandDrivenPipeline::UpdateInformation() at string:1,508 0x50a7d39505
vtkStreamingDemandDrivenPipeline::Update() at string:1,508 0x50a7d45f20