[Python-Dev] Valgrind on 2.2.2

[Guido van Rossum]

> There are also a few fingers pointing in the direction of weakref_ref,
> e.g.
> 
> ==28827== 520 bytes in 14 blocks are possibly lost in loss record 48 of 106
> ==28827==    at 0x400481B4: malloc (vg_clientfuncs.c:100)
> ==28827==    by 0x8099519: _PyObject_GC_New (Modules/gcmodule.c:868)
> ==28827==    by 0x8067BA5: PyWeakref_NewRef (Objects/weakrefobject.c:37)
> ==28827==    by 0x8066119: add_subclass (Objects/typeobject.c:2249)
> ==28827==    by 0x8061F29: PyType_Ready (Objects/typeobject.c:2219)
> ==28827==    by 0x80605A8: type_new (Objects/typeobject.c:1280)
> ==28827==    by 0x805EDA4: type_call (Objects/typeobject.c:183)
> ==28827==    by 0x80ABB0C: PyObject_Call (Objects/abstract.c:1688)
> ==28827==    by 0x807A34F: PyEval_CallObjectWithKeywords (Python/ceval.c:3058)
> ==28827==    by 0x80AB0C6: PyObject_CallFunction (Objects/abstract.c:1679)
> 
> Of course many of these could be caused by a single leak that drops a
> pointer to a container -- then everything owned by that container is
> also leaked.

This one seems simple:

diff -c -c -r2.126.4.25 typeobject.c
*** typeobject.c	11 Oct 2002 00:22:22 -0000	2.126.4.25
--- typeobject.c	18 Oct 2002 00:50:31 -0000
***************
*** 2249,2256 ****
  	while (--i >= 0) {
  		ref = PyList_GET_ITEM(list, i);
  		assert(PyWeakref_CheckRef(ref));
! 		if (PyWeakref_GET_OBJECT(ref) == Py_None)
! 			return PyList_SetItem(list, i, new);
  	}
  	i = PyList_Append(list, new);
  	Py_DECREF(new);
--- 2249,2259 ----
  	while (--i >= 0) {
  		ref = PyList_GET_ITEM(list, i);
  		assert(PyWeakref_CheckRef(ref));
! 		if (PyWeakref_GET_OBJECT(ref) == Py_None) {
! 			i = PyList_SetItem(list, i, new);
! 			Py_DECREF(new);
! 			return i;
! 		}
  	}
  	i = PyList_Append(list, new);
  	Py_DECREF(new);

--Guido van Rossum (home page: http://www.python.org/~guido/)