https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92836
--- Comment #9 from Janne Blomqvist <jb at gcc dot gnu.org> --- (In reply to Thomas Koenig from comment #8) > > No. The inquire() is used only to see if the file exists already. If it > > does, the code branches to read the file, if it does not, the code branches > > to generate the data for the file and then write it. > > You have to watch out here. > > If you are > > a) using INQUIRE to check if the file exists > > b) using OPEN if it does not > > in a thread, this is classic race condition - separate threads > may INQUIRE and then try to open, in parallel. This is not atomic, > and is a classic race condition. > > You should always put such a sequence into OMP CRITICAL. This has > the nice side effect that you will also avoid this bug (which should > be fixed regardless). > > Also, why do you use inquire at all? AFAIK, it is not an error > to OPEN a file more than one if you don't change anything, so > a simple > > open (10,file="foo.dat",status="unknown") > > should, in principle, work even with OpenMP; if it doesn't, this is > another bug that needs fixing. The best way in cases like this is usually to skip the inquire, try to open the file with a suitable value for status=, and if the open fails handle the error. That avoids the race condition. That being said, like you say, this is still a case that GFortran should handle without crashing, so yes it's a bug that should be fixed.
