Re: 1.6.0 and guardians

[Michael Livshin]

Dirk Herrmann <address@hidden> writes:

> > > Hmmm... I still don't get it:  What is the resource you want to re-use by
> > > destroying the guardian?
> > 
> > the ability to greedily guard the objects in it.
> 
> I am trying to get this right:  You want to gain back the ability to guard
> the objects in the guardian, right?

I want to finalize the guardian.  this means getting back the ability
to guard the objects in it, yes.  although I don't really care what it
is, as long as I have a way to get it back. :)

> I don't see the need for such a functionality, but given there is some
> sense in it (in interactive development), the possibility to provide
> 'guarded?' and 'unguard' functions seems to be a better solution, since it
> allows to achieve the same goals on an per-object base.  Further, it
> does not lead to 'destroyed' guardian objects hanging around.

do closed file ports bother you similarly?

> BTW:  There is one point about guardians that is absolutely important, but
> does not seem to be reflected in the current code (or at least I could not
> find it):  Between the mark and sweep phases, the guardian's
> zombify_and_mark function has to be executed _before_ the weak objects are
> scanned.

you are thinking of the case where a weak hash table is guarded, and
that's the only reference to it?

right, I think we have a nice obscure bug here...

-- 
Computer Science is embarrassed by the computer.
                -- Alan Perlis