diff options
| author |   Martin Teichmann <lkb.teichmann@gmail.com> | 2018-01-28 05:17:46 +0100 |
|---|---|---|
| committer |   Nick Coghlan <ncoghlan@gmail.com> | 2018-01-28 14:17:46 +1000 |
| commit | dd0e087edc8f1e4d2c0913236b1a62a77d9db6d8 (patch) | |
| tree | ada932bb080ed3a999989e2055e66df581291d4b /Lib/contextlib.py | |
| parent | Pep 557 What's New (GH-5371) (diff) | |
| download | cpython-dd0e087edc8f1e4d2c0913236b1a62a77d9db6d8.tar.gz cpython-dd0e087edc8f1e4d2c0913236b1a62a77d9db6d8.tar.bz2 cpython-dd0e087edc8f1e4d2c0913236b1a62a77d9db6d8.zip | |
bpo-30306: release arguments of contextmanager (GH-1500)
The arguments to a generator function which is declared as a
contextmanager are stored inside the context manager, and
thus are kept alive, even when it is used as a regular context
manager, and not as a function decorator (where it needs
the original arguments to recreate the generator on each
call).
This is a possible unnecessary memory leak, so this changes
contextmanager.__enter__ to release the saved arguments,
as that method being called means that particular CM instance
isn't going to need to recreate the underlying generator.
Patch by Martin Teichmann.
Diffstat (limited to 'Lib/contextlib.py')
| -rw-r--r-- | Lib/contextlib.py | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Lib/contextlib.py b/Lib/contextlib.py index ef8f8c9f55b..1ff8cdf1cec 100644 --- a/Lib/contextlib.py +++ b/Lib/contextlib.py @@ -105,6 +105,9 @@ class _GeneratorContextManager(_GeneratorContextManagerBase, return self.__class__(self.func, self.args, self.kwds) def __enter__(self): + # do not keep args and kwds alive unnecessarily + # they are only needed for recreation, which is not possible anymore + del self.args, self.kwds, self.func try: return next(self.gen) except StopIteration: |