Re: file-locking and postmaster.pid

Alvaro Herrera <alvherre@commandprompt.com> writes:
> Certainly on all platforms there must be *some* locking primitive.  We
> just need to figure out the appropiate parameters to fcntl() or flock()
> or lockf() on each.

Quite aside from the hassle factor of needing to deal with N variants of
the syscalls, I'm not convinced that it's guaranteed to work.  ISTR that
for instance NFS file locking is pretty much Alice-in-Wonderland :-(

Since the entire point here is to have a guaranteed bulletproof check,
locks that work most of the time on most platforms/filesystems aren't
gonna be an improvement.
        regards, tom lane