ClientSession.close and Connector.close are coroutines now

CHANGES.txt

@@ -53,3 +53,5 @@ CHANGES
 - Document ClientResponse's host, method, url properties
 
 - Use CORK/NODELAY in client API #748
+
+- ClientSession.close and Connector.close are coroutines now

aiohttp/client.py

@@ -423,6 +423,9 @@ def close(self):
         if not self.closed:
             self._connector.close()
             self._connector = None
+        ret = asyncio.Future(loop=self._loop)
+        ret.set_result(None)
+        return ret
 
     @property
     def closed(self):
@@ -467,7 +470,7 @@ def __aenter__(self):
 
         @asyncio.coroutine
         def __aexit__(self, exc_type, exc_val, exc_tb):
-            self.close()
+            yield from self.close()
 
 if PY_35:
     from collections.abc import Coroutine

aiohttp/connector.py

@@ -222,14 +222,16 @@ def _start_cleanup_task(self):
 
     def close(self):
         """Close all opened transports."""
+        ret = asyncio.Future(loop=self._loop)
+        ret.set_result(None)
         if self._closed:
-            return
+            return ret
         self._closed = True
 
         try:
             if hasattr(self._loop, 'is_closed'):
                 if self._loop.is_closed():
-                    return
+                    return ret
 
             for key, data in self._conns.items():
                 for transport, proto, t0 in data:
@@ -245,6 +247,7 @@ def close(self):
             self._conns.clear()
             self._acquired.clear()
             self._cleanup_handle = None
+        return ret
 
     @property
     def closed(self):

docs/client_reference.rst

@@ -340,12 +340,18 @@ The client session supports context manager protocol for self closing.
 
          Add *origin* parameter.
 
-   .. method:: close()
+   .. coroutinemethod:: close()
 
       Close underlying connector.
 
       Release all acquired resources.
 
+      .. versionchanged:: 0.21
+
+         The method is converted into coroutine (but technically
+         returns a future for keeping backward compatibility during
+         transition period).
+
    .. method:: detach()
 
       Detach connector from session without closing the former.
@@ -706,10 +712,16 @@ BaseConnector
 
       .. versionadded:: 0.16
 
-   .. method:: close()
+   .. coroutinemethod:: close()
 
       Close all opened connections.
 
+      .. versionchanged:: 0.21
+
+         The method is converted into coroutine (but technically
+         returns a future for keeping backward compatibility during
+         transition period).
+
    .. coroutinemethod:: connect(request)
 
       Get a free connection from pool or create new one if connection