On Wednesday 12 January 2005 11:09 pm, Dan Ingalls wrote:
> Partial credit:  If you have real experience with a Squeak-like system that
> worked this way, give some report on the fragmentation behavior
> experienced.
> References to papers with practical results in the area would also be of 
interest.

Tell Ian to ask Hans Boehm. He's at HP Labs, building 3. And he's an expert in 
the topic. He's the author of a popular GC library for C programs; of course, 
it's much safer in C programs not to move things because it's sometimes hard 
to tell what's a pointer.

His slide show:
http://www.hpl.hp.com/personal/Hans_Boehm/gc/nonmoving/index.html

A description of techniques used in the Great Circle conservative GC library 
(which I believe is based on Hans Boehm's work):
http://www.cs.purdue.edu/homes/grr/ISMM98-grr-mps-cef.pdf

Henry Bakers' "Treadmill" algorithm appeared in the ACM SIGPLAN Notices in 
1992. I think it was used in a Lisp system.
http://portal.acm.org/ft_gateway.cfm?id=130862&type=pdf&coll=ACM&dl=ACM&CFID=36433663&CFTOKEN=40514639

I  believe that Smalltalk/MT's GC (which is done in a separate thread and so 
can be paused and resumed) is a non-moving scheme. They play well with 
external libraries, in part because they don't move objects.

-- 
Ned Konz
http://bike-nomad.com/squeak/