poll: data may be received when processing exception list

For the moment, this only fixes a performance issue because in the worst case,
subsequent pings (every 6 seconds) would make _poll() check in the connection
has any pending message (while processing 'rlist').

git-svn-id: https://svn.erp5.org/repos/neo/trunk@2760 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/lib/event.py

@@ -147,6 +147,8 @@ class EpollEventManager(object):
                     conn.readable()
                 finally:
                     conn.unlock()
+            if conn.hasPendingMessages():
+                self._addPendingConnection(conn)
 
         t = time()
         for conn in self.connection_dict.values():