Re: Guile + Boehm GC

[Han-Wen Nienhuys]

In article <address@hidden>,
Ludovic Courtès <address@hidden> wrote:
>Hi all,
>
>Integration of Boehm's GC within Guile was discussed at length in the
>past, especially back in 2000.  Apparently, Han-Wen even got to the
>point of having an preliminary implementation of Guile that uses it[0].
>Unfortunately the URL mentioned there is no longer valid.
>
>Han-Wen: Could you summarize your conclusions and maybe make your code
>available as well?

it's here,

  http://www.xs4all.nl/~hanwen/public/guile/guile-boehm.gz

note that this is a patch for the "old" GC code, before I took a stab
at rewriting.

It was a quick hack, and performance was a little worse, but I think
it could be just as performant as GGC. Note that many interpreters
(eg. MzScheme) use BGC by default.  Also, measuring performance of GC
is hard, since there is a space/time tradeoff, so you should really
measure the tradeoff, something I haven't done.

>More generally, do people (still) believe that Guile should use BGC?
>Back then, there was apparently some consensus that it would be a Good
>Thing.

I think it would be good to move to BGC. BGC is used by many other
interpreters, and receives more attention wrt performance and
bugfixing than GGC. Dropping code is almost always good


BTW, I ran across Judy trees today,

  http://judy.sourceforge.net/

would it be worthwhile to try replacing resizing hash tables in Guile
with Judy trees? I expect that it would incur a significant speedup.