[Python-Dev] RE: test_sort.py failure
Guido van Rossum
guido at python.org
Thu Jul 29 20:11:08 CEST 2004
> The following (just checked in) changes should solve the problem:
> * drop the unreasonable list invariant that ob_item should never come back
> to NULL during the lifetime of the object.
> * listobject.c nevertheless did not conform to the other invariants,
> either; fixed.
> * listobject.c now uses list_clear() as the obvious internal way to clear
> a list, instead of abusing list_ass_slice() for that. It makes it easier
> to enforce the invariant about ob_item == NULL.
> * listsort() sets allocated to -1 during sort; any mutation will set it
> to a value >= 0, so it is a safe way to detect mutation. A negative
> value for allocated does not cause a problem elsewhere currently.
> test_sort.py has a new test for this fix.
> * listsort() leak: if items were added to the list during the sort, AND if
> these items had a __del__ that puts still more stuff into the list,
> then this more stuff (and the PyObject** array to hold them) were
> overridden at the end of listsort() and never released.
Wow. I'm impressed. Thanks!
BTW, I just wrote a little programing for playing Conway's Game of
Life, using Tkinter. (Yes, I was inspired by Damien Conway's (no
relation) talk Tuesday night at OSCON.) Anyway, it runs at about 5.35
generations/second in Python 2.3, and 6.35 generations/second in
Python 2.4. Good job everyone!
--Guido van Rossum (home page: http://www.python.org/~guido/)
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