[gclist] Name that hypothesis

Jeremy Fitzhardinge jeremy@zip.com.au
Thu, 05 Dec 1996 21:40:40 +1100


Nick Barnes wrote:
> > "A young object is more likely to die soon than an old one".
> How can I reword my statement so that its meaning is more clear?

It seems to me that it relies too much on assumed meanings for "young"
and "old", which are perhaps too discrete to cover the more continious
behaviour of real programs (i.e. it seems to assume there's only ever a
need to have two generations).

Perhaps something like "the probability an object will die is inversely
proportional to its age".  This still leaves "age" undefined, but I
think its easier to pin a meaning on it than "young" and "old" as
classifications.

It's then up to the implementor to define/measure the "death probability
curve" for a given application and see if it has properties an allocator
can take advantage of (as Henry pointed out, its only when this curve
has discontinuities that a generational GC helps).

	J