/src/cpython/Objects/iterobject.c

Source
/* Iterator objects */

#include "Python.h"
#include "pycore_abstract.h"      // _PyObject_HasLen()
#include "pycore_call.h"          // _PyObject_CallNoArgs()
#include "pycore_ceval.h"         // _PyEval_GetBuiltin()
#include "pycore_genobject.h"     // _PyCoro_GetAwaitableIter()
#include "pycore_iterobject.h"    // _PyCallIter_NewEx()
#include "pycore_object.h"        // _PyObject_GC_TRACK()
#include "pycore_pyatomic_ft_wrappers.h"  // FT_ATOMIC_LOAD_SSIZE_RELAXED()
#include "pycore_pyerrors.h"      // _PyErr_FormatFromCause()
#include "pycore_pystate.h"       // _PyThreadState_GET()


typedef struct {
    PyObject_HEAD
    Py_ssize_t it_index;  /* -1 when iterator is exhausted */
    PyObject *it_seq; /* Set to NULL when iterator is exhausted
                         (in the default build) */
} seqiterobject;

PyObject *
PySeqIter_New(PyObject *seq)
{
    seqiterobject *it;

    if (!PySequence_Check(seq)) {
        PyErr_BadInternalCall();
        return NULL;
    }
    it = PyObject_GC_New(seqiterobject, &PySeqIter_Type);
    if (it == NULL)
        return NULL;
    it->it_index = 0;
    it->it_seq = Py_NewRef(seq);
    _PyObject_GC_TRACK(it);
    return (PyObject *)it;
}

static void
iter_dealloc(PyObject *op)
{
    seqiterobject *it = (seqiterobject*)op;
    _PyObject_GC_UNTRACK(it);
    Py_XDECREF(it->it_seq);
    PyObject_GC_Del(it);
}

static int
iter_traverse(PyObject *op, visitproc visit, void *arg)
{
    seqiterobject *it = (seqiterobject*)op;
    Py_VISIT(it->it_seq);
    return 0;
}

static PyObject *
iter_iternext(PyObject *iterator)
{
    seqiterobject *it;
    PyObject *seq;
    PyObject *result;

    assert(PySeqIter_Check(iterator));
    it = (seqiterobject *)iterator;
    Py_ssize_t index = FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index);
    if (index < 0)
        return NULL;
    seq = it->it_seq;
#ifndef Py_GIL_DISABLED
    if (seq == NULL)
        return NULL;
#endif
    if (index == PY_SSIZE_T_MAX) {
        PyErr_SetString(PyExc_OverflowError,
                        "iter index too large");
        return NULL;
    }

    result = PySequence_GetItem(seq, index);
    if (result != NULL) {
        /* PySequence_GetItem() can exhaust the iterator re-entrantly.
         * Preserve the exhaustion sentinel if it is observed.  Concurrent
         * exhaustion can still race with the store, but remains memory-safe
         * because the sequence stays alive. */
        if (FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index) >= 0) {
            FT_ATOMIC_STORE_SSIZE_RELAXED(it->it_index, index + 1);
        }
        return result;
    }
    if (PyErr_ExceptionMatches(PyExc_IndexError) ||
        PyErr_ExceptionMatches(PyExc_StopIteration))
    {
        /* Mark the iterator exhausted before anything that can run
         * arbitrary code. */
        FT_ATOMIC_STORE_SSIZE_RELAXED(it->it_index, -1);
#ifndef Py_GIL_DISABLED
        Py_CLEAR(it->it_seq);
#endif
        PyErr_Clear();
    }
    return NULL;
}

static PyObject *
iter_len(PyObject *op, PyObject *Py_UNUSED(ignored))
{
    seqiterobject *it = (seqiterobject*)op;
    Py_ssize_t seqsize, len;

    Py_ssize_t index = FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index);
    if (index >= 0 && it->it_seq != NULL) {
        if (_PyObject_HasLen(it->it_seq)) {
            seqsize = PySequence_Size(it->it_seq);
            if (seqsize == -1)
                return NULL;
        }
        else {
            Py_RETURN_NOTIMPLEMENTED;
        }
        len = seqsize - index;
        if (len >= 0)
            return PyLong_FromSsize_t(len);
    }
    return PyLong_FromLong(0);
}

PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");

static PyObject *
iter_reduce(PyObject *op, PyObject *Py_UNUSED(ignored))
{
    seqiterobject *it = (seqiterobject*)op;
    PyObject *iter = _PyEval_GetBuiltin(&_Py_ID(iter));

    /* _PyEval_GetBuiltin can invoke arbitrary code,
     * call must be before access of iterator pointers.
     * see issue #101765 */

    Py_ssize_t index = FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index);
    if (index >= 0 && it->it_seq != NULL)
        return Py_BuildValue("N(O)n", iter, it->it_seq, index);
    else
        return Py_BuildValue("N(())", iter);
}

PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");

static PyObject *
iter_setstate(PyObject *op, PyObject *state)
{
    seqiterobject *it = (seqiterobject*)op;
    Py_ssize_t index = PyLong_AsSsize_t(state);
    if (index == -1 && PyErr_Occurred())
        return NULL;
    if (index < 0)
        index = 0;
    if (it->it_seq && FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index) >= 0) {
        FT_ATOMIC_STORE_SSIZE_RELAXED(it->it_index, index);
    }
    Py_RETURN_NONE;
}

PyDoc_STRVAR(setstate_doc, "Set state information for unpickling.");

static PyMethodDef seqiter_methods[] = {
    {"__length_hint__", iter_len, METH_NOARGS, length_hint_doc},
    {"__reduce__", iter_reduce, METH_NOARGS, reduce_doc},
    {"__setstate__", iter_setstate, METH_O, setstate_doc},
    {NULL,              NULL}           /* sentinel */
};

PyTypeObject PySeqIter_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "iterator",                                 /* tp_name */
    sizeof(seqiterobject),                      /* tp_basicsize */
    0,                                          /* tp_itemsize */
    /* methods */
    iter_dealloc,                               /* tp_dealloc */
    0,                                          /* tp_vectorcall_offset */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    0,                                          /* tp_as_async */
    0,                                          /* tp_repr */
    0,                                          /* tp_as_number */
    0,                                          /* tp_as_sequence */
    0,                                          /* tp_as_mapping */
    0,                                          /* tp_hash */
    0,                                          /* tp_call */
    0,                                          /* tp_str */
    PyObject_GenericGetAttr,                    /* tp_getattro */
    0,                                          /* tp_setattro */
    0,                                          /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,    /* tp_flags */
    0,                                          /* tp_doc */
    iter_traverse,                              /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    PyObject_SelfIter,                          /* tp_iter */
    iter_iternext,                              /* tp_iternext */
    seqiter_methods,                            /* tp_methods */
    0,                                          /* tp_members */
};

/* -------------------------------------- */

typedef struct {
    PyObject_HEAD
    PyObject *it_callable;  /* set to NULL when the iterator is exhausted */
    PyObject *it_sentinel;  /* can be NULL, and is when exhausted */
    PyObject *it_stop_exc;  /* never NULL */
} calliterobject;

PyObject *
_PyCallIter_NewEx(PyObject *callable, PyObject *sentinel, PyObject *stop_exc)
{
    calliterobject *it;
    if (stop_exc == NULL) {
        stop_exc = PyExc_StopIteration;
    }
    else if (_PyEval_CheckExceptTypeValid(_PyThreadState_GET(), stop_exc) < 0) {
        return NULL;
    }
    it = PyObject_GC_New(calliterobject, &PyCallIter_Type);
    if (it == NULL)
        return NULL;
    it->it_callable = Py_NewRef(callable);
    it->it_sentinel = Py_XNewRef(sentinel);
    it->it_stop_exc = Py_NewRef(stop_exc);
    _PyObject_GC_TRACK(it);
    return (PyObject *)it;
}

PyObject *
PyCallIter_New(PyObject *callable, PyObject *sentinel)
{
    return _PyCallIter_NewEx(callable, sentinel, NULL);
}

static void
calliter_exhaust(calliterobject *it)
{
    Py_CLEAR(it->it_callable);
    Py_CLEAR(it->it_sentinel);
}

static void
calliter_dealloc(PyObject *op)
{
    calliterobject *it = (calliterobject*)op;
    _PyObject_GC_UNTRACK(it);
    Py_XDECREF(it->it_callable);
    Py_XDECREF(it->it_sentinel);
    Py_XDECREF(it->it_stop_exc);
    PyObject_GC_Del(it);
}

static int
calliter_traverse(PyObject *op, visitproc visit, void *arg)
{
    calliterobject *it = (calliterobject*)op;
    Py_VISIT(it->it_callable);
    Py_VISIT(it->it_sentinel);
    Py_VISIT(it->it_stop_exc);
    return 0;
}

static PyObject *
calliter_iternext(PyObject *op)
{
    calliterobject *it = (calliterobject*)op;
    PyObject *result;

    if (it->it_callable == NULL) {
        return NULL;
    }

    result = _PyObject_CallNoArgs(it->it_callable);
    /* The call can exhaust the iterator re-entrantly. */
    if (result != NULL && it->it_callable != NULL) {
        if (it->it_sentinel == NULL) {
            return result; /* Common case, fast path */
        }
        int ok = PyObject_RichCompareBool(it->it_sentinel, result, Py_EQ);
        if (ok == 0) {
            return result; /* Common case, fast path */
        }

        if (ok > 0) {
            calliter_exhaust(it);
        }
    }
    else if (PyErr_ExceptionMatches(it->it_stop_exc)) {
        PyErr_Clear();
        calliter_exhaust(it);
    }
    else if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
        /* It would be mistaken for the end of the iteration (see PEP 479). */
        _PyErr_FormatFromCause(PyExc_RuntimeError,
                               "callable raised StopIteration");
    }
    Py_XDECREF(result);
    return NULL;
}

static PyObject *
calliter_reduce(PyObject *op, PyObject *Py_UNUSED(ignored))
{
    calliterobject *it = (calliterobject*)op;
    PyObject *iter = _PyEval_GetBuiltin(&_Py_ID(iter));

    /* _PyEval_GetBuiltin can invoke arbitrary code,
     * call must be before access of iterator pointers.
     * see issue #101765 */

    if (it->it_callable == NULL) {
        return Py_BuildValue("N(())", iter);
    }
    /* Only the sentinel can be passed as an argument of iter(), so other
       attributes are restored from the state (see calliter_setstate()). */
    if (it->it_sentinel == NULL) {
        return Py_BuildValue("N(OO)(()O)", iter, it->it_callable, Py_None,
                             it->it_stop_exc);
    }
    else if (it->it_stop_exc == PyExc_StopIteration) {
        return Py_BuildValue("N(OO)", iter, it->it_callable, it->it_sentinel);
    }
    else {
        return Py_BuildValue("N(OO)((O)O)", iter, it->it_callable, Py_None,
                             it->it_sentinel, it->it_stop_exc);
    }
}

static PyObject *
calliter_setstate(PyObject *op, PyObject *state)
{
    calliterobject *it = (calliterobject*)op;
    PyObject *sentinel, *stop_exc;

    if (!PyTuple_Check(state) || PyTuple_GET_SIZE(state) != 2) {
        goto error;
    }
    sentinel = PyTuple_GET_ITEM(state, 0);
    stop_exc = PyTuple_GET_ITEM(state, 1);
    if (!PyTuple_Check(sentinel) || PyTuple_GET_SIZE(sentinel) > 1) {
        goto error;
    }
    if (_PyEval_CheckExceptTypeValid(_PyThreadState_GET(), stop_exc) < 0) {
        return NULL;
    }
    if (it->it_callable != NULL) {
        Py_XSETREF(it->it_sentinel,
                   PyTuple_GET_SIZE(sentinel) ?
                   Py_NewRef(PyTuple_GET_ITEM(sentinel, 0)) : NULL);
        Py_SETREF(it->it_stop_exc, Py_NewRef(stop_exc));
    }
    Py_RETURN_NONE;

error:
    PyErr_SetString(PyExc_TypeError, "invalid state for callable_iterator");
    return NULL;
}

static PyMethodDef calliter_methods[] = {
    {"__reduce__", calliter_reduce, METH_NOARGS, reduce_doc},
    {"__setstate__", calliter_setstate, METH_O, setstate_doc},
    {NULL,              NULL}           /* sentinel */
};

PyTypeObject PyCallIter_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "callable_iterator",                        /* tp_name */
    sizeof(calliterobject),                     /* tp_basicsize */
    0,                                          /* tp_itemsize */
    /* methods */
    calliter_dealloc,                           /* tp_dealloc */
    0,                                          /* tp_vectorcall_offset */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    0,                                          /* tp_as_async */
    0,                                          /* tp_repr */
    0,                                          /* tp_as_number */
    0,                                          /* tp_as_sequence */
    0,                                          /* tp_as_mapping */
    0,                                          /* tp_hash */
    0,                                          /* tp_call */
    0,                                          /* tp_str */
    PyObject_GenericGetAttr,                    /* tp_getattro */
    0,                                          /* tp_setattro */
    0,                                          /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,    /* tp_flags */
    0,                                          /* tp_doc */
    calliter_traverse,                          /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    PyObject_SelfIter,                          /* tp_iter */
    calliter_iternext,                          /* tp_iternext */
    calliter_methods,                           /* tp_methods */
};

Coverage Report

Created: 2026-10-31 06:21

Line	Count	Source
1		/* Iterator objects */
2
3		#include "Python.h"
4		#include "pycore_abstract.h" // _PyObject_HasLen()
5		#include "pycore_call.h" // _PyObject_CallNoArgs()
6		#include "pycore_ceval.h" // _PyEval_GetBuiltin()
7		#include "pycore_genobject.h" // _PyCoro_GetAwaitableIter()
8		#include "pycore_iterobject.h" // _PyCallIter_NewEx()
9		#include "pycore_object.h" // _PyObject_GC_TRACK()
10		#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_LOAD_SSIZE_RELAXED()
11		#include "pycore_pyerrors.h" // _PyErr_FormatFromCause()
12		#include "pycore_pystate.h" // _PyThreadState_GET()
13
14
15		typedef struct {
16		PyObject_HEAD
17		Py_ssize_t it_index; /* -1 when iterator is exhausted */
18		PyObject it_seq; / Set to NULL when iterator is exhausted
19		(in the default build) */
20		} seqiterobject;
21
22		PyObject *
23		PySeqIter_New(PyObject *seq)
24	1.72M	{
25	1.72M	seqiterobject *it;
26
27	1.72M	if (!PySequence_Check(seq)) {
28	0	PyErr_BadInternalCall();
29	0	return NULL;
30	0	}
31	1.72M	it = PyObject_GC_New(seqiterobject, &PySeqIter_Type);
32	1.72M	if (it == NULL)
33	0	return NULL;
34	1.72M	it->it_index = 0;
35	1.72M	it->it_seq = Py_NewRef(seq);
36	1.72M	_PyObject_GC_TRACK(it);
37	1.72M	return (PyObject *)it;
38	1.72M	}
39
40		static void
41		iter_dealloc(PyObject *op)
42	1.72M	{
43	1.72M	seqiterobject it = (seqiterobject)op;
44	1.72M	_PyObject_GC_UNTRACK(it);
45	1.72M	Py_XDECREF(it->it_seq);
46	1.72M	PyObject_GC_Del(it);
47	1.72M	}
48
49		static int
50		iter_traverse(PyObject op, visitproc visit, void arg)
51	2.02k	{
52	2.02k	seqiterobject it = (seqiterobject)op;
53	2.02k	Py_VISIT(it->it_seq);
54	2.02k	return 0;
55	2.02k	}
56
57		static PyObject *
58		iter_iternext(PyObject *iterator)
59	9.37M	{
60	9.37M	seqiterobject *it;
61	9.37M	PyObject *seq;
62	9.37M	PyObject *result;
63
64	9.37M	assert(PySeqIter_Check(iterator));
65	9.37M	it = (seqiterobject *)iterator;
66	9.37M	Py_ssize_t index = FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index);
67	9.37M	if (index < 0)
68	0	return NULL;
69	9.37M	seq = it->it_seq;
70	9.37M	#ifndef Py_GIL_DISABLED
71	9.37M	if (seq == NULL)
72	0	return NULL;
73	9.37M	#endif
74	9.37M	if (index == PY_SSIZE_T_MAX) {
75	0	PyErr_SetString(PyExc_OverflowError,
76	0	"iter index too large");
77	0	return NULL;
78	0	}
79
80	9.37M	result = PySequence_GetItem(seq, index);
81	9.37M	if (result != NULL) {
82		/* PySequence_GetItem() can exhaust the iterator re-entrantly.
83		* Preserve the exhaustion sentinel if it is observed. Concurrent
84		* exhaustion can still race with the store, but remains memory-safe
85		* because the sequence stays alive. */
86	7.64M	if (FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index) >= 0) {
87	7.64M	FT_ATOMIC_STORE_SSIZE_RELAXED(it->it_index, index + 1);
88	7.64M	}
89	7.64M	return result;
90	7.64M	}
91	1.72M	if (PyErr_ExceptionMatches(PyExc_IndexError) \|\|
92	0	PyErr_ExceptionMatches(PyExc_StopIteration))
93	1.72M	{
94		/* Mark the iterator exhausted before anything that can run
95		* arbitrary code. */
96	1.72M	FT_ATOMIC_STORE_SSIZE_RELAXED(it->it_index, -1);
97	1.72M	#ifndef Py_GIL_DISABLED
98	1.72M	Py_CLEAR(it->it_seq);
99	1.72M	#endif
100	1.72M	PyErr_Clear();
101	1.72M	}
102	1.72M	return NULL;
103	9.37M	}
104
105		static PyObject *
106		iter_len(PyObject op, PyObject Py_UNUSED(ignored))
107	6.62k	{
108	6.62k	seqiterobject it = (seqiterobject)op;
109	6.62k	Py_ssize_t seqsize, len;
110
111	6.62k	Py_ssize_t index = FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index);
112	6.62k	if (index >= 0 && it->it_seq != NULL) {
113	6.62k	if (_PyObject_HasLen(it->it_seq)) {
114	6.62k	seqsize = PySequence_Size(it->it_seq);
115	6.62k	if (seqsize == -1)
116	0	return NULL;
117	6.62k	}
118	0	else {
119	0	Py_RETURN_NOTIMPLEMENTED;
120	0	}
121	6.62k	len = seqsize - index;
122	6.62k	if (len >= 0)
123	6.62k	return PyLong_FromSsize_t(len);
124	6.62k	}
125	0	return PyLong_FromLong(0);
126	6.62k	}
127
128		PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
129
130		static PyObject *
131		iter_reduce(PyObject op, PyObject Py_UNUSED(ignored))
132	0	{
133	0	seqiterobject it = (seqiterobject)op;
134	0	PyObject *iter = _PyEval_GetBuiltin(&_Py_ID(iter));
135
136		/* _PyEval_GetBuiltin can invoke arbitrary code,
137		* call must be before access of iterator pointers.
138		* see issue #101765 */
139
140	0	Py_ssize_t index = FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index);
141	0	if (index >= 0 && it->it_seq != NULL)
142	0	return Py_BuildValue("N(O)n", iter, it->it_seq, index);
143	0	else
144	0	return Py_BuildValue("N(())", iter);
145	0	}
146
147		PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");
148
149		static PyObject *
150		iter_setstate(PyObject op, PyObject state)
151	0	{
152	0	seqiterobject it = (seqiterobject)op;
153	0	Py_ssize_t index = PyLong_AsSsize_t(state);
154	0	if (index == -1 && PyErr_Occurred())
155	0	return NULL;
156	0	if (index < 0)
157	0	index = 0;
158	0	if (it->it_seq && FT_ATOMIC_LOAD_SSIZE_RELAXED(it->it_index) >= 0) {
159	0	FT_ATOMIC_STORE_SSIZE_RELAXED(it->it_index, index);
160	0	}
161	0	Py_RETURN_NONE;
162	0	}
163
164		PyDoc_STRVAR(setstate_doc, "Set state information for unpickling.");
165
166		static PyMethodDef seqiter_methods[] = {
167		{"__length_hint__", iter_len, METH_NOARGS, length_hint_doc},
168		{"__reduce__", iter_reduce, METH_NOARGS, reduce_doc},
169		{"__setstate__", iter_setstate, METH_O, setstate_doc},
170		{NULL, NULL} /* sentinel */
171		};
172
173		PyTypeObject PySeqIter_Type = {
174		PyVarObject_HEAD_INIT(&PyType_Type, 0)
175		"iterator", /* tp_name */
176		sizeof(seqiterobject), /* tp_basicsize */
177		0, /* tp_itemsize */
178		/* methods */
179		iter_dealloc, /* tp_dealloc */
180		0, /* tp_vectorcall_offset */
181		0, /* tp_getattr */
182		0, /* tp_setattr */
183		0, /* tp_as_async */
184		0, /* tp_repr */
185		0, /* tp_as_number */
186		0, /* tp_as_sequence */
187		0, /* tp_as_mapping */
188		0, /* tp_hash */
189		0, /* tp_call */
190		0, /* tp_str */
191		PyObject_GenericGetAttr, /* tp_getattro */
192		0, /* tp_setattro */
193		0, /* tp_as_buffer */
194		Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC, /* tp_flags */
195		0, /* tp_doc */
196		iter_traverse, /* tp_traverse */
197		0, /* tp_clear */
198		0, /* tp_richcompare */
199		0, /* tp_weaklistoffset */
200		PyObject_SelfIter, /* tp_iter */
201		iter_iternext, /* tp_iternext */
202		seqiter_methods, /* tp_methods */
203		0, /* tp_members */
204		};
205
206		/* -------------------------------------- */
207
208		typedef struct {
209		PyObject_HEAD
210		PyObject it_callable; / set to NULL when the iterator is exhausted */
211		PyObject it_sentinel; / can be NULL, and is when exhausted */
212		PyObject it_stop_exc; / never NULL */
213		} calliterobject;
214
215		PyObject *
216		_PyCallIter_NewEx(PyObject callable, PyObject sentinel, PyObject *stop_exc)
217	376k	{
218	376k	calliterobject *it;
219	376k	if (stop_exc == NULL) {
220	376k	stop_exc = PyExc_StopIteration;
221	376k	}
222	0	else if (_PyEval_CheckExceptTypeValid(_PyThreadState_GET(), stop_exc) < 0) {
223	0	return NULL;
224	0	}
225	376k	it = PyObject_GC_New(calliterobject, &PyCallIter_Type);
226	376k	if (it == NULL)
227	0	return NULL;
228	376k	it->it_callable = Py_NewRef(callable);
229	376k	it->it_sentinel = Py_XNewRef(sentinel);
230	376k	it->it_stop_exc = Py_NewRef(stop_exc);
231	376k	_PyObject_GC_TRACK(it);
232	376k	return (PyObject *)it;
233	376k	}
234
235		PyObject *
236		PyCallIter_New(PyObject callable, PyObject sentinel)
237	376k	{
238	376k	return _PyCallIter_NewEx(callable, sentinel, NULL);
239	376k	}
240
241		static void
242		calliter_exhaust(calliterobject *it)
243	376k	{
244	376k	Py_CLEAR(it->it_callable);
245	376k	Py_CLEAR(it->it_sentinel);
246	376k	}
247
248		static void
249		calliter_dealloc(PyObject *op)
250	376k	{
251	376k	calliterobject it = (calliterobject)op;
252	376k	_PyObject_GC_UNTRACK(it);
253	376k	Py_XDECREF(it->it_callable);
254	376k	Py_XDECREF(it->it_sentinel);
255	376k	Py_XDECREF(it->it_stop_exc);
256	376k	PyObject_GC_Del(it);
257	376k	}
258
259		static int
260		calliter_traverse(PyObject op, visitproc visit, void arg)
261	1.16k	{
262	1.16k	calliterobject it = (calliterobject)op;
263	1.16k	Py_VISIT(it->it_callable);
264	1.16k	Py_VISIT(it->it_sentinel);
265	1.16k	Py_VISIT(it->it_stop_exc);
266	1.16k	return 0;
267	1.16k	}
268
269		static PyObject *
270		calliter_iternext(PyObject *op)
271	3.81M	{
272	3.81M	calliterobject it = (calliterobject)op;
273	3.81M	PyObject *result;
274
275	3.81M	if (it->it_callable == NULL) {
276	0	return NULL;
277	0	}
278
279	3.81M	result = _PyObject_CallNoArgs(it->it_callable);
280		/* The call can exhaust the iterator re-entrantly. */
281	3.81M	if (result != NULL && it->it_callable != NULL) {
282	3.81M	if (it->it_sentinel == NULL) {
283	0	return result; /* Common case, fast path */
284	0	}
285	3.81M	int ok = PyObject_RichCompareBool(it->it_sentinel, result, Py_EQ);
286	3.81M	if (ok == 0) {
287	3.43M	return result; /* Common case, fast path */
288	3.43M	}
289
290	376k	if (ok > 0) {
291	376k	calliter_exhaust(it);
292	376k	}
293	376k	}
294	0	else if (PyErr_ExceptionMatches(it->it_stop_exc)) {
295	0	PyErr_Clear();
296	0	calliter_exhaust(it);
297	0	}
298	0	else if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
299		/* It would be mistaken for the end of the iteration (see PEP 479). */
300	0	_PyErr_FormatFromCause(PyExc_RuntimeError,
301	0	"callable raised StopIteration");
302	0	}
303	376k	Py_XDECREF(result);
304	376k	return NULL;
305	3.81M	}
306
307		static PyObject *
308		calliter_reduce(PyObject op, PyObject Py_UNUSED(ignored))
309	0	{
310	0	calliterobject it = (calliterobject)op;
311	0	PyObject *iter = _PyEval_GetBuiltin(&_Py_ID(iter));
312
313		/* _PyEval_GetBuiltin can invoke arbitrary code,
314		* call must be before access of iterator pointers.
315		* see issue #101765 */
316
317	0	if (it->it_callable == NULL) {
318	0	return Py_BuildValue("N(())", iter);
319	0	}
320		/* Only the sentinel can be passed as an argument of iter(), so other
321		attributes are restored from the state (see calliter_setstate()). */
322	0	if (it->it_sentinel == NULL) {
323	0	return Py_BuildValue("N(OO)(()O)", iter, it->it_callable, Py_None,
324	0	it->it_stop_exc);
325	0	}
326	0	else if (it->it_stop_exc == PyExc_StopIteration) {
327	0	return Py_BuildValue("N(OO)", iter, it->it_callable, it->it_sentinel);
328	0	}
329	0	else {
330	0	return Py_BuildValue("N(OO)((O)O)", iter, it->it_callable, Py_None,
331	0	it->it_sentinel, it->it_stop_exc);
332	0	}
333	0	}
334
335		static PyObject *
336		calliter_setstate(PyObject op, PyObject state)
337	0	{
338	0	calliterobject it = (calliterobject)op;
339	0	PyObject sentinel, stop_exc;
340
341	0	if (!PyTuple_Check(state) \|\| PyTuple_GET_SIZE(state) != 2) {
342	0	goto error;
343	0	}
344	0	sentinel = PyTuple_GET_ITEM(state, 0);
345	0	stop_exc = PyTuple_GET_ITEM(state, 1);
346	0	if (!PyTuple_Check(sentinel) \|\| PyTuple_GET_SIZE(sentinel) > 1) {
347	0	goto error;
348	0	}
349	0	if (_PyEval_CheckExceptTypeValid(_PyThreadState_GET(), stop_exc) < 0) {
350	0	return NULL;
351	0	}
352	0	if (it->it_callable != NULL) {
353	0	Py_XSETREF(it->it_sentinel,
354	0	PyTuple_GET_SIZE(sentinel) ?
355	0	Py_NewRef(PyTuple_GET_ITEM(sentinel, 0)) : NULL);
356	0	Py_SETREF(it->it_stop_exc, Py_NewRef(stop_exc));
357	0	}
358	0	Py_RETURN_NONE;
359
360	0	error:
361	0	PyErr_SetString(PyExc_TypeError, "invalid state for callable_iterator");
362		return NULL;
363	0	}
364
365		static PyMethodDef calliter_methods[] = {
366		{"__reduce__", calliter_reduce, METH_NOARGS, reduce_doc},
367		{"__setstate__", calliter_setstate, METH_O, setstate_doc},
368		{NULL, NULL} /* sentinel */
369		};
370
371		PyTypeObject PyCallIter_Type = {
372		PyVarObject_HEAD_INIT(&PyType_Type, 0)
373		"callable_iterator", /* tp_name */
374		sizeof(calliterobject), /* tp_basicsize */
375		0, /* tp_itemsize */
376		/* methods */
377		calliter_dealloc, /* tp_dealloc */
378		0, /* tp_vectorcall_offset */
379		0, /* tp_getattr */
380		0, /* tp_setattr */
381		0, /* tp_as_async */
382		0, /* tp_repr */
383		0, /* tp_as_number */
384		0, /* tp_as_sequence */
385		0, /* tp_as_mapping */
386		0, /* tp_hash */
387		0, /* tp_call */
388		0, /* tp_str */
389		PyObject_GenericGetAttr, /* tp_getattro */
390		0, /* tp_setattro */
391		0, /* tp_as_buffer */
392		Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC, /* tp_flags */
393		0, /* tp_doc */
394		calliter_traverse, /* tp_traverse */
395		0, /* tp_clear */
396		0, /* tp_richcompare */
397		0, /* tp_weaklistoffset */
398		PyObject_SelfIter, /* tp_iter */
399		calliter_iternext, /* tp_iternext */
400		calliter_methods, /* tp_methods */
401		};