Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!uunet!lll-winken!oli-stl!asylum!hoptoad!gnu
From: gnu@hoptoad.uucp (John Gilmore)
Newsgroups: gnu.emacs.bug
Subject: Re: File locking on shared filesystems
Message-ID: <7443@hoptoad.uucp>
Date: 26 May 89 07:05:26 GMT
References: <8905070035.AA13356@transit.cs.brown.edu> <89May24.155639edt.30763@snow.white.toronto.edu>
Organization: Grasshopper Group in San Francisco
Lines: 19

Please consider this another voice requesting no file locking, or a
trivial option to turn it off.  I ran emacs under the SunOS 4.0 "trace"
command to see why it was so slow when going from message to message under
"mhe" (the RAND mail handler under Emacs).  It was doing massive numbers
of system calls to lock and unlock each mail message!

Most Unixes these days provide "flock" or "lockf" advisory locking
system calls, that work cheaply on an open file descriptor, over the
net or locally.  Use these, if you must, (and get the vendors to fix
them if they fail), but please spare me the ridiculous, unwanted,
overhead.

In using vi since 1982, I have only once had a file overwritten by two
simultaneous edits by separate people.  This "insurance" is not worth
the performance cost.
-- 
John Gilmore    {sun,pacbell,uunet,pyramid,amdahl}!hoptoad!gnu    gnu@toad.com
  A well-regulated militia, being necessary to the security of a free State,
  the right of the people to keep and bear arms, shall not be infringed.