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Created on 2012-11-11 18:07 by pitrou, last changed 2022-04-11 14:57 by admin. This issue is now closed.

Messages (5)
msg175378 - (view) Author: Antoine Pitrou (pitrou) * (Python committer) Date: 2012-11-11 18:07
Dead weakrefs to a given object happen to be equal if they don't have a callback, but unequal if they do. However, they are always equal when alive: >>> class O: pass ... >>> o = O() >>> def cb(_): pass ... >>> q = weakref.ref(o) >>> r = weakref.ref(o) >>> s = weakref.ref(o, cb) >>> t = weakref.ref(o, cb) >>> q == r True >>> s == t True >>> del o >>> q() is None True >>> q == r True >>> s == t False This may be related to the following optimization (?): >>> q is r True >>> s is t False
msg175379 - (view) Author: Antoine Pitrou (pitrou) * (Python committer) Date: 2012-11-11 18:11
Aha, it is even worse: >>> o = O() >>> q = weakref.ref(o) >>> r = weakref.ref(o) >>> del o >>> q() is None True >>> q == r True >>> q != r True
msg175380 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2012-11-11 18:42
New changeset 590f1b55abea by Antoine Pitrou in branch '3.2': Issue #16453: Fix equality testing of dead weakref objects. http://hg.python.org/cpython/rev/590f1b55abea New changeset c00e2c1cb3a7 by Antoine Pitrou in branch '3.3': Issue #16453: Fix equality testing of dead weakref objects. http://hg.python.org/cpython/rev/c00e2c1cb3a7 New changeset 9e80ea48ff39 by Antoine Pitrou in branch 'default': Issue #16453: Fix equality testing of dead weakref objects. http://hg.python.org/cpython/rev/9e80ea48ff39
msg175381 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2012-11-11 18:49
New changeset 13b74c0b040c by Antoine Pitrou in branch '2.7': Issue #16453: Fix equality testing of dead weakref objects. http://hg.python.org/cpython/rev/13b74c0b040c
msg175383 - (view) Author: Antoine Pitrou (pitrou) * (Python committer) Date: 2012-11-11 19:04
Now fixed.
History
Date User Action Args
2022-04-11 14:57:38adminsetgithub: 60657
2012-11-17 02:47:49jceasetnosy: + jcea
2012-11-11 19:04:22pitrousetstatus: open -> closed
resolution: fixed
messages: + msg175383

stage: resolved
2012-11-11 18:49:06python-devsetmessages: + msg175381
2012-11-11 18:42:01python-devsetnosy: + python-dev
messages: + msg175380
2012-11-11 18:11:53pitrousetmessages: + msg175379
2012-11-11 18:07:35pitroucreate