1 files changed, 85 insertions, 0 deletions
diff --git a/include/python2.7/weakrefobject.h b/include/python2.7/weakrefobject.h
new file mode 100644
index 0000000..e46aecf
--- /dev/null
+++ b/include/python2.7/weakrefobject.h
@@ -0,0 +1,85 @@
+/* Weak references objects for Python. */
+
+#ifndef Py_WEAKREFOBJECT_H
+#define Py_WEAKREFOBJECT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+typedef struct _PyWeakReference PyWeakReference;
+
+/* PyWeakReference is the base struct for the Python ReferenceType, ProxyType,
+ * and CallableProxyType.
+ */
+struct _PyWeakReference {
+    PyObject_HEAD
+
+    /* The object to which this is a weak reference, or Py_None if none.
+     * Note that this is a stealth reference:  wr_object's refcount is
+     * not incremented to reflect this pointer.
+     */
+    PyObject *wr_object;
+
+    /* A callable to invoke when wr_object dies, or NULL if none. */
+    PyObject *wr_callback;
+
+    /* A cache for wr_object's hash code.  As usual for hashes, this is -1
+     * if the hash code isn't known yet.
+     */
+    long hash;
+
+    /* If wr_object is weakly referenced, wr_object has a doubly-linked NULL-
+     * terminated list of weak references to it.  These are the list pointers.
+     * If wr_object goes away, wr_object is set to Py_None, and these pointers
+     * have no meaning then.
+     */
+    PyWeakReference *wr_prev;
+    PyWeakReference *wr_next;
+};
+
+PyAPI_DATA(PyTypeObject) _PyWeakref_RefType;
+PyAPI_DATA(PyTypeObject) _PyWeakref_ProxyType;
+PyAPI_DATA(PyTypeObject) _PyWeakref_CallableProxyType;
+
+#define PyWeakref_CheckRef(op) PyObject_TypeCheck(op, &_PyWeakref_RefType)
+#define PyWeakref_CheckRefExact(op) \
+        (Py_TYPE(op) == &_PyWeakref_RefType)
+#define PyWeakref_CheckProxy(op) \
+        ((Py_TYPE(op) == &_PyWeakref_ProxyType) || \
+         (Py_TYPE(op) == &_PyWeakref_CallableProxyType))
+
+/* This macro calls PyWeakref_CheckRef() last since that can involve a
+   function call; this makes it more likely that the function call
+   will be avoided. */
+#define PyWeakref_Check(op) \
+        (PyWeakref_CheckRef(op) || PyWeakref_CheckProxy(op))
+
+
+PyAPI_FUNC(PyObject *) PyWeakref_NewRef(PyObject *ob,
+                                              PyObject *callback);
+PyAPI_FUNC(PyObject *) PyWeakref_NewProxy(PyObject *ob,
+                                                PyObject *callback);
+PyAPI_FUNC(PyObject *) PyWeakref_GetObject(PyObject *ref);
+
+PyAPI_FUNC(Py_ssize_t) _PyWeakref_GetWeakrefCount(PyWeakReference *head);
+
+PyAPI_FUNC(void) _PyWeakref_ClearRef(PyWeakReference *self);
+
+/* Explanation for the Py_REFCNT() check: when a weakref's target is part
+   of a long chain of deallocations which triggers the trashcan mechanism,
+   clearing the weakrefs can be delayed long after the target's refcount
+   has dropped to zero.  In the meantime, code accessing the weakref will
+   be able to "see" the target object even though it is supposed to be
+   unreachable.  See issue #16602. */
+
+#define PyWeakref_GET_OBJECT(ref)                           \
+    (Py_REFCNT(((PyWeakReference *)(ref))->wr_object) > 0   \
+     ? ((PyWeakReference *)(ref))->wr_object                \
+     : Py_None)
+
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_WEAKREFOBJECT_H */