Issue #19299: fix refleak test failures in test_asyncio

Lib/asyncio/base_events.py

@@ -185,6 +185,14 @@ class BaseEventLoop(events.AbstractEventLoop):
         """
         self.call_soon(_raise_stop_error)
 
+    def close(self):
+        self._ready.clear()
+        self._scheduled.clear()
+        executor = self._default_executor
+        if executor is not None:
+            self._default_executor = None
+            executor.shutdown(wait=False)
+
     def is_running(self):
         """Returns running status of event loop."""
         return self._running

Lib/asyncio/proactor_events.py

@@ -276,6 +276,7 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
             self._proactor.close()
             self._proactor = None
             self._selector = None
+            super().close()
 
     def sock_recv(self, sock, n):
         return self._proactor.recv(sock, n)

Lib/asyncio/selector_events.py

@@ -56,6 +56,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
             self._close_self_pipe()
             self._selector.close()
             self._selector = None
+            super().close()
 
     def _socketpair(self):
         raise NotImplementedError