postpic together with multiprocessing #257
Description
When using postpic within mutliprocessing the pyfftw causes the process to stall. I encountered this when using postpic together with https://github.com/skuschel/generatorpipeline
As a workaround this commit limts the pyfftw threads to 1:
6dce3a7
The issue is known to pyfftw:
pyFFTW/pyFFTW#135