You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
87 lines
2.8 KiB
87 lines
2.8 KiB
3 years ago
|
/* 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.
|
||
|
|
*/
|
||
|
|
#ifndef Py_LIMITED_API
|
||
|
|
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.
|
||
|
|
*/
|
||
|
|
Py_hash_t 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;
|
||
|
|
};
|
||
|
|
#endif
|
||
|
|
|
||
|
|
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_IS_TYPE(op, &_PyWeakref_RefType)
|
||
|
|
#define PyWeakref_CheckProxy(op) \
|
||
|
|
(Py_IS_TYPE(op, &_PyWeakref_ProxyType) || \
|
||
|
|
Py_IS_TYPE(op, &_PyWeakref_CallableProxyType))
|
||
|
|
|
||
|
|
#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);
|
||
|
|
|
||
|
|
#ifndef Py_LIMITED_API
|
||
|
|
PyAPI_FUNC(Py_ssize_t) _PyWeakref_GetWeakrefCount(PyWeakReference *head);
|
||
|
|
|
||
|
|
PyAPI_FUNC(void) _PyWeakref_ClearRef(PyWeakReference *self);
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* 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 */
|