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[Python-Dev] capability-mediated modules

Zooko zooko@zooko.com
Tue, 18 Mar 2003 11:36:42 -0500 
(I, Zooko, wrote the lines prepended with "> > ".)

 Aahz <aahz@pythoncraft.com> wrote:
>
> > For example, suppose you want to control the ability to listen on
> > sockets for network traffic.  If there is a reference (e.g., to an
> > object) that represents the privilege of listening on sockets, then
> > you can give such a reference to one object, allowing that object it
> > to listen on sockets, while withholding it from another object, thus
> > preventing that one from listening on sockets.
> 
> Doesn't that only work if the second object never gains a reference to
> the first object?

This is why real mandatory private data is needed.  The second object could have 
a reference to the first object, and could use the first object through some 
interface offered by the first object, without being able to access the first 
object's socket-listener capability.

Regards,

Zooko

http://zooko.com/
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