Date:	Mon, 6 Jul 1998 11:23:22 +0300 (IDT)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To:	Thomas Knudsen <tk AT gfy DOT ku DOT dk>
cc:	djgpp AT delorie DOT com
Subject:	Re: Making Libraries
In-Reply-To:	<Pine.SGI.3.95.980706092149.13588B-100000@geb.gfy.ku.dk>
Message-ID:	<Pine.SUN.3.91.980706110653.26454D-100000@is>
MIME-Version:	1.0

On Mon, 6 Jul 1998, Thomas Knudsen wrote:

> Dynamically linked versions will only require 100*10kB+0.5MB = 1.5MB,
> which is *extremely* likely to compress into a single-diskette
> distribution.

This seems very nice indeed.  But now consider the case of DJGPP: 
different programs are compiled by different individuals, many people who 
port packages to DJGPP have patched libraries which they use to compile 
ported packages, etc.  It would be a nightmare to try to resolve the 
possible conflicts due to library version mismatches, and it's impossible 
to keep all the different versions in sync.

> Also, invocation of the programs is likely to speed up, because the shared
> library is very likely to be already in the disk cache, when any of the
> programs are loaded.

This is only true if you have enough memory to leave all of the shared
library in the cache.  Please keep in mind that shared libraries are
typically used on a multi-processing system, where several programs running
simultanously, including the OS itself, share the same library copy.  This
paradigm is useless with DJGPP, even if it runs on Windows (since
different DOS boxes have separate address spaces), except when you run
nested DJGPP programs, like when Make calls the compiler. 

> mean I am volunteering to implement it (I would have no idea of how to do
> and where to start), but if anyone should have the guts to attack the
> problem, I do not think they should be discouraged: Fighting Software
> Megalomania is one of the ways we can make the world a better place to
> live!

I didn't mean to discourage anybody.  I just think that whoever is 
inclined to embark on such a mission should be aware of the pitfals and 
disadvantages, lest they will be disappointed later.

This issue comes up quite regularly on this forum, and IIRC the conclusion
is inevitably that shared libraries in the context of DJGPP are much less
attractive than some would think.  You might consider reading past
discussions of this issue by searching the DJGPP mail archives at
http://www.delorie.com/djgpp/mail-archives/. 

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