- weakref.ref and weakref.ReferenceType will become aliases for each
other
- weakref.ref will be a modern, new-style class with proper __new__
and __init__ methods
- weakref.WeakValueDictionary will have a lighter memory footprint,
using a new weakref.ref subclass to associate the key with the
value, allowing us to have only a single object of overhead for each
dictionary entry (currently, there are 3 objects of overhead per
entry: a weakref to the value, a weakref to the dictionary, and a
function object used as a weakref callback; the weakref to the
dictionary could be avoided without this change)
- a new macro, PyWeakref_CheckRefExact(), will be added
- PyWeakref_CheckRef() will check for subclasses of weakref.ref
This closes SF patch #983019.
mapping tests as possible in mapping_test.py and reuse the tests in
test_dict.py, test_userdict.py, test_weakref.py, test_os.py and test_shelve.py.
From SF patch #736962.
(re-using an existing test object class) no longer triggered the
original segfault when the fix was backed out; restoring the local
test object class to make the test effective
the assignment of the ref created at the end does not affect the test,
since the segfault happended before weakref.ref() returned; removing
the assignment
the same object to be collected by the cyclic GC support if they are
only referenced by a cycle. If the weakref being collected was one of
the weakrefs without callbacks, some local variables for the
constructor became invalid and have to be re-computed.
The test caused a segfault under a debug build without the fix applied.
Also SF patch 843455.
This is a critical bugfix.
I'll backport to 2.3 maint, but not beyond that. The bugs this fixes
have been there since weakrefs were introduced.
* Install the unittests, docs, newsitem, include file, and makefile update.
* Exercise the new functions whereever sets.py was being used.
Includes the docs for libfuncs.tex. Separate docs for the types are
forthcoming.
subtype_dealloc(): This left the dying object exposed to gc, so that
if cyclic gc triggered during the weakref callback, gc tried to delete
the dying object a second time. That's a disaster. subtype_dealloc()
had a (I hope!) unique problem here, as every normal dealloc routine
untracks the object (from gc) before fiddling with weakrefs etc. But
subtype_dealloc has obscure technical reasons for re-registering the
dying object with gc (already explained in a large comment block at
the bottom of the function).
The fix amounts to simply refraining from reregistering the dying object
with gc until after the weakref callback (if any) has been called.
This is a critical bug (hard to predict, and causes seemingly random
memory corruption when it occurs). I'll backport it to 2.3 later.
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.
Someone review this, please! Final releases are getting close, Fred
(the weakref guy) won't be around until Tuesday, and the pre-patch
code can indeed raise spurious RuntimeErrors in the presence of
threads or mutating comparison functions.
See the bug report for my confusions: I can't see any reason for why
__delitem__ iterated over the keys. The new one-liner implementation
is much faster, can't raise RuntimeError, and should be better-behaved
in all respects wrt threads.
New tests test_weak_keyed_bad_delitem and
test_weak_keyed_cascading_deletes fail before this patch.
Bugfix candidate for 2.2.3 too, if someone else agrees with this patch.
and test_support.run_classtests() into run_unittest()
and use it wherever possible.
Also don't use "from test.test_support import ...", but
"from test import test_support" in a few spots.
From SF patch #662807.
* Adds missing pop() methods to weakref.py
* Expands test suite to broaden coverage of objects with
a mapping interface.
Contributed by Sebastien Keim.
imports e.g. test_support must do so using an absolute package name
such as "import test.test_support" or "from test import test_support".
This also updates the README in Lib/test, and gets rid of the
duplicate data dirctory in Lib/test/data (replaced by
Lib/email/test/data).
Now Tim and Jack can have at it. :)
Neal Norwitz
Fred Drake
Walter Dörwald
Tim Peters
Raymond Hettinger
Guido van Rossum
Barry Warsaw
Martin v. Löwis