[armedbear-devel] (lisp) Stack management efficiency

[Alessio Stalla]

On Tue, Jul 21, 2009 at 2:21 PM, Ville
Voutilainen<ville.voutilainen at gmail.com> wrote:
>>>> 2) chunked-allocated (set aside a bunch, when all are unwound, remove
>>>> a chunk, before that, mark them unused for re-use)
>> I like that idea. We have no idea about a "normal" stack depth do we?
>
> Not really. This depends on how big our frame objects are, I think.
>
>> In that case, especially since the overhead of a single pointer seems
>> small, we should probably use a number a bit large (like 4k?), until
>> people start to complain?
>
> Four thousand frames per chunk? Sounds a bit large off-hand.

How does the Lisp stack relate to the Java stack, if they're related
at all? I don't know the maximum number of stack frames in Java, maybe
it's not even fixed, but I doubt I have ever seen stack traces longer
than a few hundred frames.

>> I think the right structure to use for (2) would be a linked list of
>> arrays. (How about using Conses to store it?)
>
> Yeah, that sounds doable.

Conses can only store LispObjects IIRC, and thus an array would need
to be wrapped... there's java.util.Stack since 1.4.2, that extends
Vector, that might do?