I have implemented in C++ an algorithm in image processing using (among other things) fftw wrappers in MKL library (version 2018.3.210)
I am working on a x64 machine with Intel Xeon E5-1650 v3 3.5 GHz processor and Windows7 as OS.
Have used MS visual studio 2015 as my IDE for development and debugging, the application is multi-threaded via C++11
<thread>
library.
When running the application over and over again I see that in about 1% of the runs it crashes.
When I have attached it to my IDE and looked at the crash dumps I saw that the crashes are always on the call:
thePlan = fftw_plan_many_dft(.....);
with the exception "Unhandled exception at someaddress (mkl_avx2.dll) in MyApp.exe: 0xC00000005 access violation reading location 0x0000000000000"
or
the exception "Unhandled exception at someaddress (mkl_avx2.dll) in MyApp.exe 0xC00000005 access violation reading location 0x0000000000018"
1. I have checked that all inputs to the call are valid (pointers were allocated with fftw_malloc()) ,other inputs have legitimate sizes and types.
2. Have run the application with Windows ApplicationVerifier attached to my IDE and got no warnings or errors.
3. Have run the application with Windows global flags attached to my IDE with all possible heap corruption checks and got no exceptions.
What else can I do to debug these crashes?