reinitialize an Event's Condition with a regular lock (closes #25319)

4 files changed, 13 insertions, 1 deletions

diff --git a/Lib/test/lock_tests.py b/Lib/test/lock_tests.py
index 2ff75c4..efc464f 100644
--- a/Lib/test/lock_tests.py
+++ b/Lib/test/lock_tests.py
@@ -305,6 +305,14 @@ class EventTests(BaseTestCase):
         for r, dt in results2:
             self.assertTrue(r)
 
+    def test_reset_internal_locks(self):
+        evt = self.eventtype()
+        old_lock = evt._Event__cond._Condition__lock
+        evt._reset_internal_locks()
+        new_lock = evt._Event__cond._Condition__lock
+        self.assertIsNot(new_lock, old_lock)
+        self.assertIs(type(new_lock), type(old_lock))
+
 
 class ConditionTests(BaseTestCase):
     """
diff --git a/Lib/threading.py b/Lib/threading.py
index 27a5511..51205fa 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -565,7 +565,7 @@ class _Event(_Verbose):
 
     def _reset_internal_locks(self):
         # private!  called by Thread._reset_internal_locks by _after_fork()
-        self.__cond.__init__()
+        self.__cond.__init__(Lock())
 
     def isSet(self):
         'Return true if and only if the internal flag is true.'
diff --git a/Misc/ACKS b/Misc/ACKS
index 34f0a0a..5a30dab 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1290,6 +1290,7 @@ Ryan Smith-Roberts
 Rafal Smotrzyk
 Eric Snow
 Dirk Soede
+Nir Soffer
 Paul Sokolovsky
 Evgeny Sologubov
 Cody Somerville
diff --git a/Misc/NEWS b/Misc/NEWS
index 0c4ea1f..eb43f1f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -43,6 +43,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #25319: When threading.Event is reinitialized, the underlying condition
+  should use a regular lock rather than a recursive lock.
+
 - Issue #25232: Fix CGIRequestHandler to split the query from the URL at the
   first question mark (?) rather than the last. Patch from Xiang Zhang.