diff options
Diffstat (limited to 'Modules/itertoolsmodule.c')
| -rw-r--r-- | Modules/itertoolsmodule.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c index 943c1e8607b..2003546ce84 100644 --- a/Modules/itertoolsmodule.c +++ b/Modules/itertoolsmodule.c @@ -1124,7 +1124,6 @@ typedef struct { PyObject *it; PyObject *saved; Py_ssize_t index; - int firstpass; } cycleobject; #define cycleobject_CAST(op) ((cycleobject *)(op)) @@ -1165,8 +1164,7 @@ itertools_cycle_impl(PyTypeObject *type, PyObject *iterable) } lz->it = it; lz->saved = saved; - lz->index = 0; - lz->firstpass = 0; + lz->index = -1; return (PyObject *)lz; } @@ -1199,11 +1197,11 @@ cycle_next(PyObject *op) cycleobject *lz = cycleobject_CAST(op); PyObject *item; - if (lz->it != NULL) { + Py_ssize_t index = FT_ATOMIC_LOAD_SSIZE_RELAXED(lz->index); + + if (index < 0) { item = PyIter_Next(lz->it); if (item != NULL) { - if (lz->firstpass) - return item; if (PyList_Append(lz->saved, item)) { Py_DECREF(item); return NULL; @@ -1213,15 +1211,22 @@ cycle_next(PyObject *op) /* Note: StopIteration is already cleared by PyIter_Next() */ if (PyErr_Occurred()) return NULL; + index = 0; + FT_ATOMIC_STORE_SSIZE_RELAXED(lz->index, 0); +#ifndef Py_GIL_DISABLED Py_CLEAR(lz->it); +#endif } if (PyList_GET_SIZE(lz->saved) == 0) return NULL; - item = PyList_GET_ITEM(lz->saved, lz->index); - lz->index++; - if (lz->index >= PyList_GET_SIZE(lz->saved)) - lz->index = 0; - return Py_NewRef(item); + item = PyList_GetItemRef(lz->saved, index); + assert(item); + index++; + if (index >= PyList_GET_SIZE(lz->saved)) { + index = 0; + } + FT_ATOMIC_STORE_SSIZE_RELAXED(lz->index, index); + return item; } static PyType_Slot cycle_slots[] = { |