Merge 3.4

Doc/library/asyncio-eventloop.rst

@@ -123,7 +123,7 @@ Run an event loop
 
    Returns ``True`` if the event loop was closed.
 
-   .. versionadded:: 3.5
+   .. versionadded:: 3.4.2
 
 .. method:: BaseEventLoop.close()
 

Misc/NEWS

@@ -92,6 +92,10 @@ Core and Builtins
 Library
 -------
 
+- Issue #21326: Add a new is_closed() method to asyncio.BaseEventLoop.
+  run_forever() and run_until_complete() methods of asyncio.BaseEventLoop now
+  raise an exception if the event loop was closed.
+
 - Issue #21310: Fixed possible resource leak in failed open().
 
 - Issue #21256: Printout of keyword args should be in deterministic order in