Fixed #21952 -- signals deadlock due to locking + weakref interaction

1 files changed, 4 insertions, 3 deletions

diff --git a/tests/dispatch/tests/test_dispatcher.py b/tests/dispatch/tests/test_dispatcher.py
index 1ab4a69d33..05b375f7d6 100644
--- a/tests/dispatch/tests/test_dispatcher.py
+++ b/tests/dispatch/tests/test_dispatcher.py
@@ -46,11 +46,12 @@ class DispatcherTests(unittest.TestCase):
 
     def _testIsClean(self, signal):
         """Assert that everything has been cleaned up automatically"""
+        # Note that dead weakref cleanup happens as side effect of using
+        # the signal's receivers through the signals API. So, first do a
+        # call to an API method to force cleanup.
+        self.assertFalse(signal.has_listeners())
         self.assertEqual(signal.receivers, [])
 
-        # force cleanup just in case
-        signal.receivers = []
-
     def testExact(self):
         a_signal.connect(receiver_1_arg, sender=self)
         expected = [(receiver_1_arg, "test")]