python/aqmp: stop the server during disconnect()

Before we allow the full separation of starting the server and accepting
new connections, make sure that the disconnect cleans up the server and
its new state, too.

Signed-off-by: John Snow <jsnow@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20220225205948.3693480-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

python/qemu/aqmp/protocol.py

@@ -432,7 +432,7 @@ class AsyncProtocol(Generic[T]):
         self._runstate_event.set()
         self._runstate_event.clear()
 
-    @bottom_half  # However, it does not run from the R/W tasks.
+    @bottom_half
     async def _stop_server(self) -> None:
         """
         Stop listening for / accepting new incoming connections.
@@ -709,6 +709,7 @@ class AsyncProtocol(Generic[T]):
 
         self._reader = None
         self._writer = None
+        self._accepted = None
 
         # NB: _runstate_changed cannot be cleared because we still need it to
         # send the final runstate changed event ...!
@@ -732,6 +733,9 @@ class AsyncProtocol(Generic[T]):
         def _done(task: Optional['asyncio.Future[Any]']) -> bool:
             return task is not None and task.done()
 
+        # If the server is running, stop it.
+        await self._stop_server()
+
         # Are we already in an error pathway? If either of the tasks are
         # already done, or if we have no tasks but a reader/writer; we
         # must be.