Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!uunet!coplex!dean
From: dean@coplex.uucp (Dean Brooks)
Newsgroups: comp.mail.elm
Subject: Re: Will ELM ever use lockf()?
Message-ID: <1991Mar30.213039.28713@coplex.uucp>
Date: 30 Mar 91 21:30:39 GMT
References: <1991Mar25.193741.12360@coplex.uucp> <27F120EF.63A3@tct.uucp>
Organization: Copper Electronics, Inc.
Lines: 32

chip@tct.uucp (Chip Salzenberg) writes:

>According to dean@coplex.uucp (Dean Brooks):
>>   Elm wants to use "flock()" or ".lock" files.  Smail wants to
>>use "flock()", "lockf()" or its own weird type of lock files.

>Check the Smail source code -- specifically, sysdep.c.  Smail does use
>".lock" files, just like Elm.

Yeah, but ".lock" files dont hack hack it for 20 messages all trying
to arrive in your mailbox at the same time.  The window of
vulnerability seems quite small, but after trying tests with smail3.1
and elm2.3.11, it dropped about 3 messages out of 20 into oblivion.

I basically ran 20 smail's at the same time, with the basic command
of "smail dean < /etc/termcap".  They all started immediately into the
background; on the average, three of the 20 never ever made it to my
mailbox.

Of course, this symptom probably only occurs when mail is received in
large quantities on a fast system.  

Regardless, I hacked the elm code to use "lockf()" (quite an easy
task, after I found the syntax of the flock() command), and
everything worked perfectly on our SYSV system.

					Thanks... Dean
--
dean@coplex.UUCP   Dean A. Brooks
                   Copper Electronics, Inc.
                   Louisville, Ky
UUCP: !uunet!coplex!dean