Re: fcntl(SETLK) [was Re: 2nd update on TOAST]

Alfred Perlstein <bright@wintelcom.net>

From: Alfred Perlstein <bright@wintelcom.net>
To: Bruce Momjian <pgman@candle.pha.pa.us>
Cc: Mike Mascari <mascarm@mascari.com>, Jan Wieck <JanWieck@Yahoo.com>, PostgreSQL HACKERS <pgsql-hackers@postgresql.org>
Date: 2000-07-08T13:28:00Z
Lists: pgsql-hackers
* Bruce Momjian <pgman@candle.pha.pa.us> [000708 06:02] wrote:
> > > my $pgsocket = "/tmp/.s.PGSQL.5432";
> > > 
> > > # try to connect to the postmaster
> > > socket(SOCK, PF_UNIX, SOCK_STREAM, 0)
> > >         or die "unable to create unix domain socket: $!";
> > > 
> > > connect(SOCK, sockaddr_un($pgsocket))
> > >         and errexit("postmaster is running you must shut it down");
> > > 
> > > oh yeah... :)
> > > 
> > > -Alfred
> > 
> > I don't get this. Isn't there a race condition here?
> 
> That's a good point.  I don't think so because the socket will only
> create for one user.  Basically, we don't need something bulletproof
> here.  We just need something to prevent admins from accidentally
> starting two postmasters on the same port.

Actually I just remebered the issue here, if one wants to start
postmaster on an alternate port there will be no conflict and 
all hell may break loose.

-Alfred