oo hardware

Marcel Weiher marcel at metaobject.com
Sat Mar 22 12:16:12 UTC 2003


On Saturday, March 22, 2003, at 12:08  Uhr, Tim Rowledge wrote:

> Jimmie Houchin <jhouchin at texoma.net> wrote:
>
>> How does this compare to these discussions and the Squeak VM design?
>>
>> The design of the Inferno virtual machine
>> http://www.vitanuova.com/inferno/papers/hotchips.html
> Well, almost the first thing they say about garbage collection is just
> plain wrong; reference counting is _not_ exact, unless one has the
> special case that reference counts can be functionally infinite.

Hmm...if you have a 32 bit reference count field, a 32 bit address 
space for your objects and a minimum of 4 bytes for your objects, then 
I would think reference counting *is* exact, because you can accomodate 
2^32 references to your object but can never have that many objects in 
your system.  (Assuming that the number of external references is small)

> In any
> practical case one will have potential for refCt field overflow and a
> need to deal with it.

You probably have a lot more experience with this, but I don't see why 
that would be the case.

Marcel

-- 
Marcel Weiher				Metaobject Software Technologies
marcel at metaobject.com		www.metaobject.com
Metaprogramming for the Graphic Arts.   HOM, IDEAs, MetaAd etc.



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