Path: utzoo!utstat!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!newstop!sun!amdcad!dgcad!gary
From: gary@proa.sv.dg.com (Gary Bridgewater)
Newsgroups: news.software.b
Subject: B-news locking (was Duplicate articles ...)
Message-ID: <660393258.3719@proa.sv.dg.com>
Date: 5 Dec 90 10:34:19 GMT
References: <16070@bfmny0.BFM.COM> <113417@uunet.UU.NET> <1088@ai.cs.utexas.edu>
Organization: Data General SDD, Sunnyvale, CA
Lines: 17

In article <1088@ai.cs.utexas.edu> fletcher@cs.utexas.edu (Fletcher Mattox) writes:
>Speaking of B news locking, what prevents concurrent instances
>of rnews from writing simultaneously to the history file?  A quick 
>look at the code suggests savehist() could be doing this.  

It happens via lock() and unlock() in ifuncs.c.  This locks - using whatever
mechanism you have - /usr/lib/news/sys.
It's called, generally, by localize() as the article is going to be posted.
If you run multiple unbatches / rnews' make sure this locking works.  And
don't fool with sys (or active) while its running.  From experience - don't
run any "clean out junk" script that dinks with active while unbatching - unless
it locks sys as well.
I've been running up to 4 rnews processes at a time for a few weeks - under B -
and haven't seen any problems.
-- 
Gary Bridgewater, Data General Corporation, Sunnyvale California
gary@sv.dg.com or {amdahl,aeras,amdcad}!dgcad!gary
C++ - it's the right thing to do.