On Thu, Dec 22, 2011 at 07:19:03PM -0600, Chris Muller wrote:
> Santa hath come early this year!  This is a double-win -- because we
> can not only interrupt again but performance should be better too.
> This was for Igors attempt to improve the finalization mechanism,
> ironically for better performance back in 2010 I think -- and in which
> I was very interested because of how the hyper-activity of the
> finalization process was causing half of the processing time to be
> spent spinning through the weak references.

I hope that this hold up as a proper fix, and it certainly does
need to be reviewed. But I want to be sure I do not leave any bad
impression about the new finalization mechanism. Igor's improved
finalization mechanism is in fact a *huge* performance win. People
starting with a freshly downloaded image may not notice it, but
as time goes on the benefits become more apparent. When using an
image over a long period of time (as I tend to do), the accumulated
load of handling weak finalization can be a real problem. Igor's new
finalization mechanism addresses this very effectively, and this results
in very noticable real-world performance improvements for Squeak.

I think that I may have uncovered a problem in the weak finalization
update process that has gone unnoticed for a long time. If so, then
good, this should help the new finalization to work as intended. But
kudos to Igor for implementing the weak finalization improvements,
and I hope that fixing this glitch in the weak finalization process
will clean up a few loose ends.

Dave