> On 2012-02-05, at 8:49 AM, David Levine wrote:
> > Or to really
> > play it safe, have configure determine which are available
> > and use them all?
> At the same time? Sounds like a recipe for deadlock to me. And it won't
> work correctly, if at all, on platforms that implement one or more of
> fcntl/flock/lockf as wrappers around one of the others (e.g. Solaris).
So it sounds like picking one default for each platform and
allowing run-time selection is the way to go.
> configure should be able to set this on a per-platform basis.
It can't because it depends on what other applications use.
> As for internal locking, it's a toss-up between flock and lockf. To me
> the tie breaker is which of the two gets along best with network mounted
> filesystems these days (and think AFP and CIFS in addition to NFS).
> And forget about fcntl -- the semantics are too broken for
> consideration. If neither of flock/lockf are available, we can fall back
> to dot locking.
Fedora /bin/mail uses fcntl and Mutt recommends it.
procmail can use it. I haven't had any problems since I
starting using fcntl. I did see problems with dot locking,
I expect because other applications weren't using it.