gh-89967: make WeakKeyDictionary and WeakValueDictionary thread safe (#125325)

Make `WeakKeyDictionary` and `WeakValueDictionary` thread safe by copying the underlying the dict before iterating over it. 

1 files changed, 0 insertions, 25 deletions

diff --git a/Lib/_weakrefset.py b/Lib/_weakrefset.py
index 2071755..d1c7fca 100644
--- a/Lib/_weakrefset.py
+++ b/Lib/_weakrefset.py
@@ -8,31 +8,6 @@ from types import GenericAlias
 __all__ = ['WeakSet']
 
 
-class _IterationGuard:
-    # This context manager registers itself in the current iterators of the
-    # weak container, such as to delay all removals until the context manager
-    # exits.
-    # This technique should be relatively thread-safe (since sets are).
-
-    def __init__(self, weakcontainer):
-        # Don't create cycles
-        self.weakcontainer = ref(weakcontainer)
-
-    def __enter__(self):
-        w = self.weakcontainer()
-        if w is not None:
-            w._iterating.add(self)
-        return self
-
-    def __exit__(self, e, t, b):
-        w = self.weakcontainer()
-        if w is not None:
-            s = w._iterating
-            s.remove(self)
-            if not s:
-                w._commit_removals()
-
-
 class WeakSet:
     def __init__(self, data=None):
         self.data = set()