Raise a RuntimeError when tee iterator is consumed from different threads (GH-15567)

This commit is contained in:
HongWeipeng 2019-08-29 11:39:25 +08:00 committed by Raymond Hettinger
parent 13f37f2ba8
commit fa220ec763
3 changed files with 12 additions and 1 deletions

View File

@ -643,7 +643,8 @@ loops that truncate the stream.
Once :func:`tee` has made a split, the original *iterable* should not be
used anywhere else; otherwise, the *iterable* could get advanced without
the tee objects being informed.
the tee objects being informed. the :func:`tee` iterator can not be consumed
from different threads, even if an underlying iterator is thread-safe.
This itertool may require significant auxiliary storage (depending on how
much temporary data needs to be stored). In general, if one iterator uses

View File

@ -0,0 +1,2 @@
Raise a RuntimeError when itertools.tee() iterator is consumed from different
threads. Patch by hongweipeng.

View File

@ -452,6 +452,7 @@ typedef struct {
teedataobject *dataobj;
int index; /* 0 <= index <= LINKCELLS */
PyObject *weakreflist;
unsigned long thread_id;
} teeobject;
static PyTypeObject teedataobject_type;
@ -680,6 +681,11 @@ tee_next(teeobject *to)
{
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 @@ tee_copy(teeobject *to, PyObject *Py_UNUSED(ignored))
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 @@ tee_fromiterable(PyObject *iterable)
to->index = 0;
to->weakreflist = NULL;
to->thread_id = PyThread_get_thread_ident();
PyObject_GC_Track(to);
done:
Py_XDECREF(it);