[Jython-bugs] [ jython-Bugs-947306 ] 2.3a0 bug in weakref.WeakValueDictionary

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Bugs item #947306, was opened at 2004-05-03 22:02
Message generated for change (Settings changed) made by fwierzbicki
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Category: Library
>Group: Deferred
Status: Open
Resolution: None
>Priority: 4
Submitted By: D Morley (rabidechidna)
Assigned to: Nobody/Anonymous (nobody)
Summary: 2.3a0 bug in weakref.WeakValueDictionary

Initial Comment:
In Jython 2.3a0, (as in Python 2.3) the 
WeakValueDictionary.__makeremove method in Lib/weakref.py 
relies on being able to make a weakref of self. In Jython, this 
raises an exception, because _weakref.ref(x) requires x to be 
hashable (which WeakValueDictionary is not). In Python, 
_weakref.ref(x) works on unhashable objects.

The problem did not arise in Jython 2.1, as the code in Lib/weakref  
did not try to create a weakref to itself (and so resulted in hash 
tables containing circular references).

Possible fixes off the top of my head:

(better) Fix _weakref.java so it doesn't require a hashable object.

(easier) Don't bother creating a weakref to self in 
WeakValueDictionary.__makeremove since Jython can GC circular 
references.

There are probably similar problems in other parts of weakref.py

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