[Zope] memory leak in a very simple product. Way?

[Christoph Wierling]

[Thomas B. Passin]
>
> [Christoph Wierling]
> >
> > I've writte a very simple product which creates 100 simple objects
> > (testProd class instances) and each of these objects has a list-attribute
> > which contains 200 other objects (item class instances). (Please find the
> > code at the end of this mail.)
> > By starting the addTestProd-function I create 20000 references to
> > item objects, as the Zope-debug option as well as the leakFinder-product
> > tell me.
> > But I'll never get rid of these references and earlier or later I'll run
> > out of memory.
> >
> > Could anybody explain me, way this simple product is leaking like a sieve?
> > And how I can get rid of the references?
> >
> >
> > here is the code:
> >
> > ...
>
> > class testProd(SimpleItem.SimpleItem):
> >     """ testProd docu """
> >
> >     meta_type = 'testProd'
> >
> >     def __init__(self, id, title = ''):
> >         self.id = id
> >         self.title = title
> >
> >         self._tree = []
> >
> >         for i in xrange(200):
> >             n = item(str(i),i)
> >             tree = self._tree
> >             tree.append(n)
> >             self._tree = tree
> >
>
> I think you really want to do this:
>
>          tree = []
>          for i in xrange(200):
>              n = item(str(i),i)
>              tree.append(n)
>          self._tree = tree
>

Thanks for the suggestion. Your code does about the same as my did -
it also reproduces the 20000 references to objects of the item-class.
And I also don't get rid of the 20000 references. I tried it!  :-(

christoph