From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel Subject: Re: MAIL_USE_FLOCK and Debian. Date: Mon, 17 Feb 2003 02:20:26 -0500 Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: References: <87lm0ijabw.fsf@raven.i.defaultvalue.org> <87znoxi93a.fsf@raven.i.defaultvalue.org> Reply-To: rms@gnu.org NNTP-Posting-Host: main.gmane.org X-Trace: main.gmane.org 1045466609 10015 80.91.224.249 (17 Feb 2003 07:23:29 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Mon, 17 Feb 2003 07:23:29 +0000 (UTC) Cc: emacs-devel@gnu.org Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by main.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 18kfcd-0002bN-00 for ; Mon, 17 Feb 2003 08:23:27 +0100 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.12 #1 (Debian)) id 18kfqu-00066X-00 for ; Mon, 17 Feb 2003 08:38:13 +0100 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 18kfdx-0007GS-0E for emacs-devel@quimby.gnus.org; Mon, 17 Feb 2003 02:24:49 -0500 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.10.13) id 18kfdT-0006he-00 for emacs-devel@gnu.org; Mon, 17 Feb 2003 02:24:19 -0500 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.10.13) id 18kfdF-0006SH-00 for emacs-devel@gnu.org; Mon, 17 Feb 2003 02:24:05 -0500 Original-Received: from fencepost.gnu.org ([199.232.76.164]) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 18kfZi-0004mW-00 for emacs-devel@gnu.org; Mon, 17 Feb 2003 02:20:26 -0500 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.10) id 18kfZi-0007eI-00; Mon, 17 Feb 2003 02:20:26 -0500 Original-To: Rob Browning In-reply-to: <87znoxi93a.fsf@raven.i.defaultvalue.org> (message from Rob Browning on Sat, 15 Feb 2003 14:26:33 -0600) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1b5 Precedence: list List-Id: Emacs development discussions. List-Help: List-Post: List-Subscribe: , List-Archive: List-Unsubscribe: , Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:11700 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:11700 If I understand the situation correctly, I'm not sure this is anything that actually can be decided automatically. The problem is that in the final analysis, the policies with respect to locking may come down to a local administrative decision. I think that is even more reason to control the decision at run time. Binaries are often moved from machine to machine, on a given platform. People will, for instance, install the Debian Emacs package on various Debian systems, some of which use liblockfile and some of which don't. A run-time configuration option is much more powerful and convenient. So the code should compile support for using liblockfile whenever liblockfile is defined, and should compile the other method as well (whichever other method is used now), and the final choice would be controlled by an environment variable or a file installed with Emacs. It would be ok to extend this idea of run-time choice to the question of whether to use flock. The idea would be that there are three possible methods, and the code for each one would be compiled whenever the platform permits that, and the final choice would be made at run time. The variable MAIL_USE_FLOCK would then help control the default setting for the run-time choice. Do you agree? Would you like to implement it?