Date: Mon, 6 Jul 1998 11:23:22 +0300 (IDT) From: Eli Zaretskii To: Thomas Knudsen cc: djgpp AT delorie DOT com Subject: Re: Making Libraries In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Precedence: bulk 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/.