PEP 205, Weak References -- initial checkin.
diff --git a/Include/classobject.h b/Include/classobject.h
index 8fde040..06c178f 100644
--- a/Include/classobject.h
+++ b/Include/classobject.h
@@ -24,6 +24,7 @@
PyObject_HEAD
PyClassObject *in_class; /* The class object */
PyObject *in_dict; /* A dictionary */
+ PyObject *in_weakreflist; /* List of weak references */
} PyInstanceObject;
typedef struct {
diff --git a/Include/object.h b/Include/object.h
index de67505..1eaa900 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -246,8 +246,8 @@
/* rich comparisons */
richcmpfunc tp_richcompare;
- /* More spares */
- long tp_xxx8;
+ /* weak reference enabler */
+ long tp_weaklistoffset;
#ifdef COUNT_ALLOCS
/* these must be last */
@@ -284,6 +284,8 @@
extern DL_IMPORT(int) PyNumber_Coerce(PyObject **, PyObject **);
extern DL_IMPORT(int) PyNumber_CoerceEx(PyObject **, PyObject **);
+extern DL_IMPORT(int) (*PyObject_ClearWeakRefs)(PyObject *);
+
/* Helpers for printing recursive container types */
extern DL_IMPORT(int) Py_ReprEnter(PyObject *);
extern DL_IMPORT(void) Py_ReprLeave(PyObject *);
@@ -418,7 +420,7 @@
#define Py_INCREF(op) (_Py_RefTotal++, (op)->ob_refcnt++)
#define Py_DECREF(op) \
- if (--_Py_RefTotal, --(op)->ob_refcnt != 0) \
+ if (--_Py_RefTotal, (--((op)->ob_refcnt) != 0)) \
; \
else \
_Py_Dealloc((PyObject *)(op))
diff --git a/Include/objimpl.h b/Include/objimpl.h
index 4909517..93c5b23 100644
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -160,7 +160,11 @@
/* Macros trading binary compatibility for speed. See also pymem.h.
Note that these macros expect non-NULL object pointers.*/
#define PyObject_INIT(op, typeobj) \
- ( (op)->ob_type = (typeobj), _Py_NewReference((PyObject *)(op)), (op) )
+ ((op)->ob_type = (typeobj), _Py_NewReference((PyObject *)(op)), \
+ (PyType_SUPPORTS_WEAKREFS((typeobj)) \
+ ? *(PyObject_GET_WEAKREFS_LISTPTR(op)) = NULL \
+ : NULL), \
+ (op))
#define PyObject_INIT_VAR(op, typeobj, size) \
( (op)->ob_size = (size), PyObject_INIT((op), (typeobj)) )
@@ -266,6 +270,12 @@
#endif /* WITH_CYCLE_GC */
+/* Test if a type supports weak references */
+#define PyType_SUPPORTS_WEAKREFS(t) ((t)->tp_weaklistoffset > 0)
+
+#define PyObject_GET_WEAKREFS_LISTPTR(o) \
+ ((PyObject **) (((char *) (o)) + (o)->ob_type->tp_weaklistoffset))
+
#ifdef __cplusplus
}
#endif