Re: mailbox locks

[woods@most.weird.com (Greg A. Woods)]

[ On Sat, August 17, 1996 at 12:16:23 (+0300), Matti Aarnio wrote: ]
> Subject: mailbox locks
>
> 	The mailbox locks are not quite so simple as I had
> 	thought.   Autoconfiguring will detect system locking
> 	capabilities -- with an assumption that having locking
> 	system calls (library functions), they are usable.
> 
> 	Some experiences with autoconfigured Linux seems to
> 	indicate that only "dotlock" method should be used,
> 	or that the order of locks used now is wrong.

I think a generic MTA (or more correctly MDA) should always use the old
dot-locking scheme, and if this succeeds and there are system file
locking functions that also work then they should also be applied.

As a default behaviour this should be most compatible with the majority
of vendor supplied and add-on MUAs.

Of course if you're moving mailboxes to somewhere other than the
traditional /{usr,var}[/spool]/mail area, then you can perhaps assume
the local systems programmer is regularizing not only the new mailbox
location, but also the locking scheme, so it would be good to have some
number of "--with" options to configure that can specify one specific
scheme (where a "scheme" might be some combination of basic locking
styles).

Strong words in the README document should warn the installer that it is
important to try and ensure that all tools which either read or write
system mail spool files should use the same locking scheme on a given
system, and that this is far more critical than picking the most elegant
locking scheme.

-- 
							Greg A. Woods

+1 416 443-1734			VE3TCP			robohack!woods
Planix, Inc. <woods@planix.com>; Secrets of the Weird <woods@weird.com>