#include "Python.h"

#include "pycore_dict.h" // _PyDict_DelItemIf()

#include "pycore_object.h" // _PyObject_GET_WEAKREFS_LISTPTR()

#include "pycore_weakref.h" // _PyWeakref_IS_DEAD()

#define GET_WEAKREFS_LISTPTR(o) \

((PyWeakReference **) _PyObject_GET_WEAKREFS_LISTPTR(o))

#include "clinic/_weakref.c.h"

static Py_ssize_t

_weakref_getweakrefcount_impl(PyObject *module, PyObject *object)

{

return _PyWeakref_GetWeakrefCount(object);

}

static int

is_dead_weakref(PyObject *value, void *unused)

{

if (!PyWeakref_Check(value)) {

PyErr_SetString(PyExc_TypeError, "not a weakref");

return -1;

}

return _PyWeakref_IS_DEAD(value);

}

static PyObject *

_weakref__remove_dead_weakref_impl(PyObject *module, PyObject *dct,

PyObject *key)

{

if (_PyDict_DelItemIf(dct, key, is_dead_weakref, NULL) < 0) {

return NULL;

}

Py_RETURN_NONE;

}

static PyObject *

_weakref_getweakrefs(PyObject *module, PyObject *object)

{

if (!_PyType_SUPPORTS_WEAKREFS(Py_TYPE(object))) {

return PyList_New(0);

}

PyObject *result = PyList_New(0);

if (result == NULL) {

return NULL;

}

LOCK_WEAKREFS(object);

PyWeakReference *current = *GET_WEAKREFS_LISTPTR(object);

while (current != NULL) {

PyObject *curobj = (PyObject *) current;

if (_Py_TryIncref(curobj)) {

if (PyList_Append(result, curobj)) {

UNLOCK_WEAKREFS(object);

Py_DECREF(curobj);

Py_DECREF(result);

return NULL;

}

else {

// Undo our _Py_TryIncref. This is safe to do with the lock

// held in free-threaded builds; the list holds a reference to

// curobj so we're guaranteed not to invoke the destructor.

Py_DECREF(curobj);

}

}

current = current->wr_next;

}

UNLOCK_WEAKREFS(object);

return result;

}

static PyObject *

_weakref_proxy_impl(PyObject *module, PyObject *object, PyObject *callback)

{

return PyWeakref_NewProxy(object, callback);

}

static PyMethodDef

weakref_functions[] = {

_WEAKREF_GETWEAKREFCOUNT_METHODDEF

_WEAKREF__REMOVE_DEAD_WEAKREF_METHODDEF

_WEAKREF_GETWEAKREFS_METHODDEF

_WEAKREF_PROXY_METHODDEF

{NULL, NULL, 0, NULL}

};

static int

weakref_exec(PyObject *module)

{

if (PyModule_AddObjectRef(module, "ref", (PyObject *) &_PyWeakref_RefType) < 0) {

return -1;

}

if (PyModule_AddObjectRef(module, "ReferenceType",

(PyObject *) &_PyWeakref_RefType) < 0) {

return -1;

}

if (PyModule_AddObjectRef(module, "ProxyType",

(PyObject *) &_PyWeakref_ProxyType) < 0) {

return -1;

}

if (PyModule_AddObjectRef(module, "CallableProxyType",

(PyObject *) &_PyWeakref_CallableProxyType) < 0) {

return -1;

}

return 0;

}

static struct PyModuleDef_Slot weakref_slots[] = {

_Py_ABI_SLOT,

{Py_mod_exec, weakref_exec},

{Py_mod_multiple_interpreters, Py_MOD_PER_INTERPRETER_GIL_SUPPORTED},

{Py_mod_gil, Py_MOD_GIL_NOT_USED},

{0, NULL}

};

static struct PyModuleDef weakrefmodule = {

PyModuleDef_HEAD_INIT,

"_weakref",

"Weak-reference support module.",

0,

weakref_functions,

weakref_slots,

NULL,

NULL,

NULL

};

PyInit__weakref(void)

{

return PyModuleDef_Init(&weakrefmodule);

}