delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2003/05/10/23:50:52

Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Date: Sat, 10 May 2003 23:50:41 -0400
From: Christopher Faylor <cgf AT redhat DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: cygipc (and PostgreSQL) XP problem resolved!
Message-ID: <20030511035041.GA20950@redhat.com>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <3EBD3179 DOT 6070004 AT ece DOT gatech DOT edu> <20030510171629 DOT GB11448 AT redhat DOT com> <3EBD3896 DOT 8000202 AT ece DOT gatech DOT edu> <1052612200 DOT 897 DOT 31 DOT camel AT localhost> <20030511012322 DOT GA18836 AT redhat DOT com> <1052617309 DOT 897 DOT 43 DOT camel AT localhost> <20030511014650 DOT GB18993 AT redhat DOT com> <1052618088 DOT 907 DOT 49 DOT camel AT localhost> <20030511023703 DOT GE18993 AT redhat DOT com> <1052623871 DOT 907 DOT 52 DOT camel AT localhost>
Mime-Version: 1.0
In-Reply-To: <1052623871.907.52.camel@localhost>
User-Agent: Mutt/1.4.1i

On Sun, May 11, 2003 at 01:31:12PM +1000, Robert Collins wrote:
>On Sun, 2003-05-11 at 12:37, Christopher Faylor wrote:
>> >>>I can't comment further without looking into the ftok spec again, which
>> >>>I don't have time for right now...
>> >>
>> >>I'm not sure what ftok has to do with whether global atoms are global
>> >>or not, however.
>
>Because you where suggesting the use of global atoms in ftok() - or did
>I get confused? 

One of us must be.  It is a given that ftok has to be consistent across
logins.  Otherwise a process which is trying share Sys V semaphores will
not be able to share the same ids (which are usually based on ftok)
among different processes.

As you noted, since global atoms can't do that consistently, they are
worthless.  What global atoms do seem to do is provide unique values
across the system.  Unfortunately, one session doesn't seem to be able
to access another session's atoms even if the ids are unique.

cgf

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019