The old Gen_fmgrtab.sh script used temporary file names that included
its process PID. It had this comment about that:
# We use the temporary files to avoid problems with concurrent runs
# (which can happen during parallel make).
The new implementation uses temp files that just have ".tmp" appended to
the target file name. If there is a risk that "make -j" will run the
same action twice in parallel, this isn't good enough. While it
wouldn't be too tough to add the PID to the scripts, I wonder whether
this comment is about a real problem or just a flight of fancy. It
doesn't seem to me that parallel make ought to be stupid enough to
do the same action twice. Anybody know?
regards, tom lane