Skip to content

gh-123471: Make itertools.dropwhile and itertools.takewhile safe in the FT build#146021

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
eendebakpt wants to merge 7 commits into
base:main
Choose a base branch
from
Open

gh-123471: Make itertools.dropwhile and itertools.takewhile safe in the FT build #146021

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
11491c1
Make itertools.dropwhile and itertools.takewhile safe in the free-thr…
eendebakpt Mar 16, 2026
3646a80
Merge branch 'main' into dropwhile_ft
eendebakpt Mar 16, 2026
22166cf
Merge branch 'main' into dropwhile_ft
eendebakpt Mar 16, 2026
3185eb8
Merge branch 'main' into dropwhile_ft
eendebakpt Mar 17, 2026
c036fdc
Merge branch 'main' into dropwhile_ft
eendebakpt Mar 18, 2026
0f716a6
Merge branch 'main' into dropwhile_ft
eendebakpt Mar 19, 2026
e563eb1
Merge branch 'main' into dropwhile_ft
eendebakpt May 8, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2026-03-16-00-00-00.gh-issue-123471.dw_tw_iter.rst
View file
Open in desktop
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,2 @@
Make concurrent iteration over :class:`itertools.dropwhile` and
:class:`itertools.takewhile` safe under free-threading.
8 changes: 4 additions & 4 deletions Modules/itertoolsmodule.c
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1343,7 +1343,7 @@ dropwhile_next(PyObject *op)
item = iternext(it);
if (item == NULL)
return NULL;
if (lz->start == 1)
if (FT_ATOMIC_LOAD_LONG_RELAXED(lz->start) == 1)
return item;

good = PyObject_CallOneArg(lz->func, item);
Expand All@@ -1354,7 +1354,7 @@ dropwhile_next(PyObject *op)
ok = PyObject_IsTrue(good);
Py_DECREF(good);
if (ok == 0) {
lz->start = 1;
FT_ATOMIC_STORE_LONG_RELAXED(lz->start, 1);
return item;
}
Py_DECREF(item);
Expand DownExpand Up@@ -1460,7 +1460,7 @@ takewhile_next(PyObject *op)
PyObject *it = lz->it;
long ok;

if (lz->stop == 1)
if (FT_ATOMIC_LOAD_LONG_RELAXED(lz->stop) == 1)
return NULL;

item = (*Py_TYPE(it)->tp_iternext)(it);
Expand All@@ -1478,7 +1478,7 @@ takewhile_next(PyObject *op)
return item;
Py_DECREF(item);
if (ok == 0)
lz->stop = 1;
FT_ATOMIC_STORE_LONG_RELAXED(lz->stop, 1);
return NULL;
}

Expand Down
Loading