`Modules/_weakref.c`

cpython 3.14 @ ab2d84fe1023/Modules/_weakref.c

A thin wrapper module. All weak-reference mechanics (the PyWeakReference object layout, callback invocation, GC integration, the per-object weakref list) live in Objects/weakrefobject.c. This file just binds four of those C functions as Python-callable methods and packages them into the _weakref built-in module.

The public weakref module (Lib/weakref.py) imports _weakref and re-exports ref, proxy, getweakrefcount, and getweakrefs alongside its own pure-Python WeakValueDictionary, WeakKeyDictionary, and WeakSet.

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Lines	Symbol	Role	gopy
1-20	includes	Header: `Python.h`, `weakrefobject.h`.	—
20-50	`weakref_getweakrefcount`, `weakref_getweakrefs`, `weakref_proxy`, `weakref_ref`	Python-callable wrappers.	`module/weakref/module.go:methods`
50-80	`_weakref_methods[]`	Method table.	`module/weakref/module.go:Module`
80-100	`_weakrefmodule`, `PyInit__weakref`	Module definition and entry point.	`module/weakref/module.go:Module`

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Method table (lines 50 to 80)

cpython 3.14 @ ab2d84fe1023/Modules/_weakref.c#L50-80

The four exported methods and their Python signatures:

static PyMethodDef _weakref_methods[] = {
    {"getweakrefcount", weakref_getweakrefcount, METH_O,
     "Return the number of weak references to 'object'."},
    {"getweakrefs",     weakref_getweakrefs,     METH_O,
     "Return a list of all weak reference objects pointing to 'object'."},
    {"proxy",           weakref_proxy,           METH_VARARGS,
     "create a proxy object that weakly references 'object'"},
    {"ref",             weakref_ref,             METH_VARARGS,
     PyDoc_STR("ref(object[, callback]) -- create a weak reference to 'object'")},
    {NULL, NULL, 0, NULL}
};

METH_O means a single positional argument is passed as a bare PyObject * (no argument parsing overhead). METH_VARARGS is used for proxy and ref because they accept an optional callback argument.

`weakref_getweakrefcount` (lines 20 to 35)

cpython 3.14 @ ab2d84fe1023/Modules/_weakref.c#L20-35

Delegates directly to _PyWeakref_GetWeakrefCount from Objects/weakrefobject.c:

static PyObject *
weakref_getweakrefcount(PyObject *self, PyObject *object)
{
    return PyLong_FromSsize_t(_PyWeakref_GetWeakrefCount(
        _PyObject_GET_WEAKREFS_LISTPTR(object)));
}

_PyObject_GET_WEAKREFS_LISTPTR reads the tp_weaklistoffset field of the object's type to locate the PyWeakReference * head pointer embedded in the object. If the type does not support weak references (tp_weaklistoffset == 0) the list pointer is NULL and the count is 0.

`weakref_ref` (lines 42 to 50)

cpython 3.14 @ ab2d84fe1023/Modules/_weakref.c#L42-50

Calls PyWeakref_NewRef, which is the canonical public API for creating a weakref.ref:

static PyObject *
weakref_ref(PyObject *self, PyObject *args)
{
    PyObject *object, *callback = NULL;
    if (!PyArg_UnpackTuple(args, "ref", 1, 2, &object, &callback))
        return NULL;
    return PyWeakref_NewRef(object, callback);
}

PyWeakref_NewRef (in Objects/weakrefobject.c) checks that the type supports weak references, looks for an existing ref with the same callback in the object's weakref list (to share the PyWeakReference object when possible), and inserts a new node at the head of the list otherwise.

gopy mirror

module/weakref/module.go. The four methods forward to the objects package functions WeakrefGetCount, WeakrefGetRefs, WeakrefNewProxy, and WeakrefNewRef that port Objects/weakrefobject.c.

CPython 3.14 changes

This file has been stable since Python 2. The module gained multi-phase init support (Py_mod_exec) in 3.12 but otherwise the method table is unchanged.

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Reading​

Method table (lines 50 to 80)​

weakref_getweakrefcount (lines 20 to 35)​

weakref_ref (lines 42 to 50)​

gopy mirror​

CPython 3.14 changes​

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