[vtk-developers] [VTK 0012655]: Data race in vtkAlgorithm triggered by vtkImageAppend

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
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http://vtk.org/Bug/view.php?id=12655 
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Reported By:                Ben Payne
Assigned To:                
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Project:                    VTK
Issue ID:                   12655
Category:                   (No Category)
Reproducibility:            have not tried
Severity:                   minor
Priority:                   high
Status:                     backlog
Project:                    Kitware 
Type:                       crash 
Resolution:                 open
Fixed in Version:           
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Date Submitted:             2011-10-14 10:55 EDT
Last Modified:              2011-10-14 10:55 EDT
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Summary:                    Data race in vtkAlgorithm triggered by
vtkImageAppend
Description: 
I just spent several hours tracking down a mysterious crash, which appears to be
due to an insidious race condition triggered when running a multi-threaded
vtkImageAppend filter.

The crux of the problem is that vtkImageAppend::ThreadedRequestData() indirectly
calls vtkAlgorithm::GetOutputPort() which, despite outward appearances is *not*
thread-safe.

I found this race by running helgrind (a valgrind tool) on our application -
which  spits out the following (threads 8 and 9 are the algorithm's worker
threads):

==4282== Possible data race during read of size 8 at 0x2c3f0c20 by thread
http://vtk.org/Bug/view.php?id=9
==4282==    at 0xFBF50C: vtkSmartPointer<vtkAlgorithmOutput>::operator
vtkAlgorithmOutput*() const (vtkSmartPointer.h:75)
==4282==    by 0xFBE287: vtkAlgorithm::GetOutputPort(int)
(vtkAlgorithm.cxx:1218)
==4282==    by 0xFF4712: vtkExecutive::GetProducerPort(vtkDataObject*)
(vtkExecutive.cxx:419)
==4282==    by 0xFDD976: vtkDataObject::GetProducerPort()
(vtkDataObject.cxx:362)
==4282==    by 0x101C4DC: vtkImageData::GetScalarType() (vtkImageData.cxx:1498)
==4282==    by 0x101C94F: vtkImageData::GetScalarSize() (vtkImageData.cxx:1579)
==4282==    by 0xF42F2D: vtkImageAppend::InitOutput(int*, vtkImageData*)
(vtkImageAppend.cxx:427)
==4282==    by 0xF430CA: vtkImageAppend::ThreadedRequestData(vtkInformation*,
vtkInformationVector**, vtkInformationVector*, vtkImageData***, vtkImageData**,
int*, int) (vtkImageAppend.cxx:476)
==4282==    by 0x10C2714: vtkThreadedImageAlgorithmThreadedExecute(void*)
(vtkThreadedImageAlgorithm.cxx:202)
==4282==    by 0x4C29D69: mythread_wrapper (hg_intercepts.c:221)
==4282==    by 0x9C4CD8B: start_thread (pthread_create.c:304)
==4282==    by 0xB74104C: clone (clone.S:112)
==4282==  This conflicts with a previous write of size 8 by thread
http://vtk.org/Bug/view.php?id=8
==4282==    at 0x1255D7A: vtkSmartPointerBase::Swap(vtkSmartPointerBase&)
(vtkSmartPointerBase.cxx:105)
==4282==    by 0x1255CF8: vtkSmartPointerBase::operator=(vtkSmartPointerBase
const&) (vtkSmartPointerBase.cxx:88)
==4282==    by 0xFBF162:
vtkSmartPointer<vtkAlgorithmOutput>::operator=(vtkSmartPointer<vtkAlgorithmOutput>
const&) (vtkSmartPointer.h:27)
==4282==    by 0xFBE2C9: vtkAlgorithm::GetOutputPort(int)
(vtkAlgorithm.cxx:1221)
==4282==    by 0xFF4712: vtkExecutive::GetProducerPort(vtkDataObject*)
(vtkExecutive.cxx:419)
==4282==    by 0xFDD976: vtkDataObject::GetProducerPort()
(vtkDataObject.cxx:362)
==4282==    by 0x101C4DC: vtkImageData::GetScalarType() (vtkImageData.cxx:1498)
==4282==    by 0x101C94F: vtkImageData::GetScalarSize() (vtkImageData.cxx:1579)
==4282==  Address 0x2c3f0c20 is 0 bytes inside a block of size 8 alloc'd
==4282==    at 0x4C28B82: operator new(unsigned long) (vg_replace_malloc.c:261)
==4282==    by 0xFC0BB3:
__gnu_cxx::new_allocator<vtkSmartPointer<vtkAlgorithmOutput>
>::allocate(unsigned long, void const*) (new_allocator.h:89)
==4282==    by 0xFC0948: std::_Vector_base<vtkSmartPointer<vtkAlgorithmOutput>,
std::allocator<vtkSmartPointer<vtkAlgorithmOutput> > >::_M_allocate(unsigned
long) (in /home/ben/Dev/virat2-superbuild-debug/TPL/VisGUI/bin/viqui)
==4282==    by 0xFC02C3: std::vector<vtkSmartPointer<vtkAlgorithmOutput>,
std::allocator<vtkSmartPointer<vtkAlgorithmOutput> >
>::_M_fill_insert(__gnu_cxx::__normal_iterator<vtkSmartPointer<vtkAlgorithmOutput>*,
std::vector<vtkSmartPointer<vtkAlgorithmOutput>,
std::allocator<vtkSmartPointer<vtkAlgorithmOutput> > > >, unsigned long,
vtkSmartPointer<vtkAlgorithmOutput> const&) (vector.tcc:414)
==4282==    by 0xFBFBED: std::vector<vtkSmartPointer<vtkAlgorithmOutput>,
std::allocator<vtkSmartPointer<vtkAlgorithmOutput> >
>::insert(__gnu_cxx::__normal_iterator<vtkSmartPointer<vtkAlgorithmOutput>*,
std::vector<vtkSmartPointer<vtkAlgorithmOutput>,
std::allocator<vtkSmartPointer<vtkAlgorithmOutput> > > >, unsigned long,
vtkSmartPointer<vtkAlgorithmOutput> const&) (stl_vector.h:859)
==4282==    by 0xFBF4A4: std::vector<vtkSmartPointer<vtkAlgorithmOutput>,
std::allocator<vtkSmartPointer<vtkAlgorithmOutput> > >::resize(unsigned long,
vtkSmartPointer<vtkAlgorithmOutput>) (stl_vector.h:558)
==4282==    by 0xFBC7D8: vtkAlgorithm::SetNumberOfOutputPorts(int)
(vtkAlgorithm.cxx:772)
==4282==    by 0x1014A64: vtkImageAlgorithm::vtkImageAlgorithm()
(vtkImageAlgorithm.cxx:32)
==4282==    by 0x10C1BE4: vtkThreadedImageAlgorithm::vtkThreadedImageAlgorithm()
(vtkThreadedImageAlgorithm.cxx:31)
==4282==    by 0xF420D9: vtkImageAppend::vtkImageAppend()
(vtkImageAppend.cxx:31)
==4282==    by 0xF42093: vtkImageAppend::New() (vtkImageAppend.cxx:28)

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Issue History 
Date Modified    Username       Field                    Change               
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2011-10-14 10:55 Ben Payne      New Issue                                    
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