Raise a RuntimeError when tee iterator is consumed from different threads (GH-15567)
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 781d0cc..101addc 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -452,6 +452,7 @@
teedataobject *dataobj;
int index; /* 0 <= index <= LINKCELLS */
PyObject *weakreflist;
+ unsigned long thread_id;
} teeobject;
static PyTypeObject teedataobject_type;
@@ -680,6 +681,11 @@
{
PyObject *value, *link;
+ if (to->thread_id != PyThread_get_thread_ident()) {
+ PyErr_SetString(PyExc_RuntimeError,
+ "tee() iterator can not be consumed from different threads.");
+ return NULL;
+ }
if (to->index >= LINKCELLS) {
link = teedataobject_jumplink(to->dataobj);
if (link == NULL)
@@ -713,6 +719,7 @@
newto->dataobj = to->dataobj;
newto->index = to->index;
newto->weakreflist = NULL;
+ newto->thread_id = to->thread_id;
PyObject_GC_Track(newto);
return (PyObject *)newto;
}
@@ -745,6 +752,7 @@
to->index = 0;
to->weakreflist = NULL;
+ to->thread_id = PyThread_get_thread_ident();
PyObject_GC_Track(to);
done:
Py_XDECREF(it);