incremental GC

[paul@...]

With my GC problem getting really serious (refering to my earlier post)
and the const patch still not solving my issues, I had to dug into the
Lua source and make my own incremental patch.

I implemented thri-color with write barrier, and it seems to become
stable after a week's debugging... but I still have some worries about
collection speed falling behind garbage generation speed.

The current L->GCthreshold v.s. L->blocks does not seem to be a good 
measurement in calculating the gc cycles to be performed. Sometimes it
collects too often, and sometimes it fails to catch up with the garbages.

Also doubling the threshold doesn't seem to be a very good idea in 
incrememtal GC either, since it isn't truely reflecting how much memory
is really available. If the collection speed falls behind, I actually
ended up doubling the threshold again and again until memory-full.

Would anybody shed some light on the two issues? I'd love to make my
patch available if I didn't code it too wrong :P

Regards,
.paul.