diff options
| -rw-r--r-- | django/template/loaders/cached.py | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/django/template/loaders/cached.py b/django/template/loaders/cached.py index 3ed9cf3bbf..4c25acd599 100644 --- a/django/template/loaders/cached.py +++ b/django/template/loaders/cached.py @@ -19,8 +19,12 @@ class Loader(BaseLoader): def loaders(self): # Resolve loaders on demand to avoid circular imports if not self._cached_loaders: + # Set self._cached_loaders atomically. Otherwise, another thread + # could see an incomplete list. See #17303. + cached_loaders = [] for loader in self._loaders: - self._cached_loaders.append(find_template_loader(loader)) + cached_loaders.append(find_template_loader(loader)) + self._cached_loaders = cached_loaders return self._cached_loaders def find_template(self, name, dirs=None): |