asyncio, Tulip issue 171: BaseEventLoop.close() now raises an exception if the

event loop is running. You must first stop the event loop and then wait until
it stopped, before closing it.

Lib/asyncio/selector_events.py

@@ -57,11 +57,11 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
     def close(self):
         if self.is_closed():
             return
+        super().close()
         self._close_self_pipe()
         if self._selector is not None:
             self._selector.close()
             self._selector = None
-        super().close()
 
     def _socketpair(self):
         raise NotImplementedError