> -----Original Message----- > From: Geoff Clare [mailto:g...@opengroup.org] > Sent: Tuesday, November 01, 2016 11:27 AM > To: austin-group-l@opengroup.org > Subject: Re: [1003.1(2013)/Issue7+TC1 0001016]: race condition with set > -C >
> > Why are we bothering to attempt to make > (with -C) atomic just to > > solve a problem that already has a better solution ? > > The problem is not limited to lock files. That's just being used as an > example because it's the case where problems are most likely to occur. Well, the central argument of http://austingroupbugs.net/view.php?id=1016 is locking: "One common use of set -C is to implement a simple file locking mechanism, but this is impossible to do safely." I agree with Robert Elz that the issue should be resolved by referring to link(2)/ln(1) -- which has been atomic in Unix for a long time --, and possibly state in the standard that set -C may not be atomic.
