Be smarter about clearing the weakref lists for instances, instance methods,
and functions: we only need to call PyObject_ClearWeakRefs() if the weakref
list is non-NULL. Since these objects are common but weakrefs are still
unusual, saving the call at deallocation time makes a lot of sense.
diff --git a/Objects/classobject.c b/Objects/classobject.c
index 622ca58..4522097 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -585,7 +585,8 @@
extern long _Py_RefTotal;
#endif
_PyObject_GC_UNTRACK(inst);
- PyObject_ClearWeakRefs((PyObject *) inst);
+ if (inst->in_weakreflist != NULL)
+ PyObject_ClearWeakRefs((PyObject *) inst);
/* Temporarily resurrect the object. */
#ifdef Py_TRACE_REFS
@@ -2071,7 +2072,8 @@
instancemethod_dealloc(register PyMethodObject *im)
{
_PyObject_GC_UNTRACK(im);
- PyObject_ClearWeakRefs((PyObject *)im);
+ if (im->im_weakreflist != NULL)
+ PyObject_ClearWeakRefs((PyObject *)im);
Py_DECREF(im->im_func);
Py_XDECREF(im->im_self);
Py_XDECREF(im->im_class);
diff --git a/Objects/funcobject.c b/Objects/funcobject.c
index 89dd7f9..d978c3f 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -270,7 +270,8 @@
func_dealloc(PyFunctionObject *op)
{
_PyObject_GC_UNTRACK(op);
- PyObject_ClearWeakRefs((PyObject *) op);
+ if (op->func_weakreflist != NULL)
+ PyObject_ClearWeakRefs((PyObject *) op);
Py_DECREF(op->func_code);
Py_DECREF(op->func_globals);
Py_DECREF(op->func_name);