[3.12] gh-111644: Fix asyncio test_unhandled_exceptions() (GH-111713) (#111718)

miss-islington · vstinner · web-flow · commit d15fac2a6798 · 2023-11-04T06:29:20.000Z
gh-111644: Fix asyncio test_unhandled_exceptions() (GH-111713) Fix test_unhandled_exceptions() of test_asyncio.test_streams: break explicitly a reference cycle. Fix also StreamTests.tearDown(): the loop must not be closed explicitly, but using set_event_loop() which takes care of shutting down the executor with executor.shutdown(wait=True). BaseEventLoop.close() calls executor.shutdown(wait=False). (cherry picked from commit ac01e22) Co-authored-by: Victor Stinner <vstinner@python.org>
diff --git a/Lib/test/test_asyncio/test_streams.py b/Lib/test/test_asyncio/test_streams.py
@@ -37,8 +37,7 @@ def tearDown(self):
         # just in case if we have transport close callbacks
         test_utils.run_briefly(self.loop)
 
-        self.loop.close()
-        gc.collect()
+        # set_event_loop() takes care of closing self.loop in a safe way
         super().tearDown()
 
     def _basetest_open_connection(self, open_connection_fut):
@@ -1102,6 +1101,8 @@ async def handle_echo(reader, writer):
 
         self.assertEqual(messages[0]['message'],
                          'Unhandled exception in client_connected_cb')
+        # Break explicitly reference cycle
+        messages = None
 
 
 if __name__ == '__main__':
