cpython/Include/weakrefobject.h

76 lines
2.4 KiB
C

/* 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.
*/
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;
};
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);
#define PyWeakref_GET_OBJECT(ref) (((PyWeakReference *)(ref))->wr_object)
#ifdef __cplusplus
}
#endif
#endif /* !Py_WEAKREFOBJECT_H */