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Fleshed out WeakKeyDictionary.__delitem__ NEWS to cover issues raised on

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Python-Dev.  Fixed typos in test comments.  Added some trivial new test
guts to show the parallelism (now) among __delitem__, __setitem__ and
__getitem__ wrt error conditions.

Still a bugfix candidate for 2.2.3 final, but waiting for Fred to get a
chance to chime in.
This commit is contained in:
Tim Peters 2003-05-25 17:44:31 +00:00
parent 886128f4f8
commit 50d8b8b6ae
2 changed files with 23 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

12
Lib/test/test_weakref.py
View file

@ -520,8 +520,15 @@ class MappingTestCase(TestBase):
d = weakref.WeakKeyDictionary()
o = Object('1')
# An attempt to delete an object that isn't there should raise
# KetError. It didn't before 2.3.
# KeyError. It didn't before 2.3.
self.assertRaises(KeyError, d.__delitem__, o)
self.assertRaises(KeyError, d.__getitem__, o)
# If a key isn't of a weakly referencable type, __getitem__ and
# __setitem__ raise TypeError. __delitem__ should too.
self.assertRaises(TypeError, d.__delitem__, 13)
self.assertRaises(TypeError, d.__getitem__, 13)
self.assertRaises(TypeError, d.__setitem__, 13, 13)
def test_weak_keyed_cascading_deletes(self):
# SF bug 742860. For some reason, before 2.3 __delitem__ iterated
@ -552,12 +559,13 @@ class MappingTestCase(TestBase):
# Reverse it, so that the iteration implementation of __delitem__
# has to keep looping to find the first object we delete.
objs.reverse()
# Turn on mutation in C.__eq__. The first time thru the loop,
# under the iterkeys() business the first comparison will delete
# the last item iterkeys() would see, and that causes a
# RuntimeError: dictionary changed size during iteration
# when the iterkeys() loop goes around to try comparing the next
# key. After ths was fixed, it just deletes the last object *our*
# key. After this was fixed, it just deletes the last object *our*
# "for o in obj" loop would have gotten to.
mutate = True
count = 0

18
Misc/NEWS
View file

@ -12,11 +12,19 @@ What's New in Python 2.3 beta 2?
Core and builtins
-----------------
- SF bug 742860: WeakKeyDictionary __delitem__ uses iterkeys. This
wasn't as threadsafe as it should be, was very inefficient, and could
raise RuntimeError if another thread mutated the dict during
__delitem__, or if a comparison function mutated it. A new
implementation of WeakKeyDictionary.__delitem__ repairs all that.
- SF bug 742860: "WeakKeyDictionary __delitem__ uses iterkeys". This
wasn't threadsafe, was very inefficient (expected time O(len(dict))
instead of O(1)), and could raise a spurious RuntimeError if another
thread mutated the dict during __delitem__, or if a comparison function
mutated it. It also neglected to raise KeyError when the key wasn't
present; didn't raise TypeError when the key wasn't of a weakly
referencable type; and broke various more-or-less obscure dict
invariants by using a sequence of equality comparisons over the whole
set of dict keys instead of computing the key's hash code to narrow
the search to those keys with the same hash code. All of these are
considered to be bugs. A new implementation of __delitem__ repairs all
that, but note that fixing these bugs may change visible behavior in
code relying (whether intentionally or accidentally) on old behavior.
- SF bug 705231: builtin pow() no longer lets the platform C pow()
raise -1.0 to integer powers, because (at least) glibc gets it wrong