Andre,
this series of patches (six in total) adds a new coarray backend library to libgfortran. The library uses shared memory and processes to implement running multiple images on the same node. The work is based on work started by Thomas and Nicolas Koenig. No changes to the gfortran compile part are required for this.
I have a few questions. First, I see that your patch series does not use gfortran's descriptors for accessing coarrays via shared memory, as the original work by Nicolas did. Can you comment on that? Second, how did you ensure that the library is free from race conditions? Third, the code "as is" will (looking at this in a cursory way) will probly fail on systems where you cannot increase mmap()ed regsions, such as macOS or Windows. Dominique pointed this out back then. Best regards
