Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site cdstar.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!panda!talcott!wjh12!cdstar!saltiel
From: saltiel@cdstar.UUCP (Jack Saltiel)
Newsgroups: net.unix
Subject: RE: 4.2 Printer Spooler Question
Message-ID: <150@cdstar.UUCP>
Date: Wed, 28-Aug-85 00:45:48 EDT
Article-I.D.: cdstar.150
Posted: Wed Aug 28 00:45:48 1985
Date-Received: Fri, 30-Aug-85 10:27:19 EDT
References: <289@drutx.UUCP>
Organization: Cambridge Digital Systems, Inc.
Lines: 33
Summary: Interlocking solution.

In article <289@drutx.UUCP>, james@drutx.UUCP (DavisJB) writes:
> In-Reply-To: your article <136@cdstar.UUCP>
> 
> In reference to "cdstar!saltiel"'s question on mutilple spoolers
> targeting one printer.  A rather simple solution to your problem
> is a follows:
> 
> To solve this, I worked out a method of using a common "printer busy"
> lock file.  

In fact, this is what we implemented yesterday. Fortunatly the HP
laserjet printer does not have any time dependent problems.
Everything that comes the serial line is handled serially.

A filter that wants the printer checks for the existence of a lock
every N seconds, until it does not appear. When a filter is
finished, it unlinks the lock file and waits 2N seconds before
it goes away. In this manner, stuff is taken from alternate
queues.

This solution works reliably (based on two days experience.)

If anybody want the source to these filters, fire me a letter
and I'll send them off to you.

			Tanks again!

-- 
					Jack Saltiel
					Cambridge Digital Systems
					{wjh12,talcott}!cdstar!saltiel

	"Nailed retreads to my feet and prayed for better weather."