Message-Id: <3.0.1.16.19970313163747.4cd7e1b0@pop.verisim.com>
Date: Thu, 13 Mar 1997 16:37:47 -0500
To: alaric AT abwillms DOT demon DOT co DOT uk
From: Takashi Toyooka <ttoyooka AT verisim DOT com>
Subject: Re: [opendos] BAD Filesystems
Cc: opendos AT mail DOT tacoma DOT net
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At 18:27 1997/03/13 +0000, Alaric B. Williams wrote:
>On 11 Mar 97 at 16:43, jdashiel AT eagle1 DOT eaglenet DOT com wrote:
>> When an uninstall happens,
>> each associated app count number is decremented by 1.
>> Only when a shared lib has an app count of zero can it be removed
>> from the disk safely.
>
>Now, the above method is known as reference counting, and in the 
>incarnation given is OK except that apps can't refer to each other, 
>and neither can libs; there is a fixed division of things into two 
>types, [...]
>
>If we drop the distinction and just have "resources" which can link 
>to each other with reference counts, problems arise, since circular 
>chains are never destroyed;

As long as the only motivation for this is to make uninstalls cleaner,
the links need only point to those resources that are *necessary* for
the application to function.  Then, there cannot be any loops, because
if there were, that application would depend upon itself, which means
that in order to install it, you need to have installed it already!

If the application is a suite of programs that inter-operate, or are
loosely inter-dependent, each program should be a separately install-
able package (at least as far as the resource linking is concerned -
the installation program could still treat them all as one).

my $0.02,

----------------------------------------------------------------------
Takashi Toyooka <ttoyooka AT pobox DOT com>                     Verisim, Inc.
http://www.magi.com/~ttoyooka/                 http://www.verisim.com/