Issue #1868: Eliminate subtle timing issues in thread-local objects by

getting rid of the cached copy of thread-local attribute dictionary.

1 files changed, 8 insertions, 0 deletions

diff --git a/Lib/_threading_local.py b/Lib/_threading_local.py
index b0edc031cc..3af780715d 100644
--- a/Lib/_threading_local.py
+++ b/Lib/_threading_local.py
@@ -194,6 +194,10 @@ class local(_localbase):
             lock.release()
 
     def __setattr__(self, name, value):
+        if name == '__dict__':
+            raise AttributeError(
+                "%r object attribute '__dict__' is read-only"
+                % self.__class__.__name__)
         lock = object.__getattribute__(self, '_local__lock')
         lock.acquire()
         try:
@@ -203,6 +207,10 @@ class local(_localbase):
             lock.release()
 
     def __delattr__(self, name):
+        if name == '__dict__':
+            raise AttributeError(
+                "%r object attribute '__dict__' is read-only"
+                % self.__class__.__name__)
         lock = object.__getattribute__(self, '_local__lock')
         lock.acquire()
         try: