[Insight-developers] Thread safety and STL containers

[Lorensen, William E (CRD)]

Folks,
I've been trying to track down intermittent crashes in some itk tests. The crashes occurred on both
solaris and sgi.
itkCurvatureFlowTest would crash occasionally on multi processors. I tracked the problem dowm to the
ThreadedCalculateChange method in Common/itkDenseFiniteDifferenceImageFilter. It seemed that the
faceList (implemented with the STL list container) was geeting corrupted.
 
To make a long story (and long day) short, I searched google with
gnu stl thread safe
which led me to:
http://www.sgi.com/tech/stl/thread_safety.html <http://www.sgi.com/tech/stl/thread_safety.html> 
 
I fixed "the problem" by putting a lock around the push_back method on the list.
 
So... beware of STL usage in threaded code.
 
Bill