AMQP backend refactored to use default_channel

celery/backends/amqp.py

@@ -83,9 +83,9 @@ class AMQPBackend(BaseDictBackend):
                           auto_delete=self.auto_delete,
                           queue_arguments=self.queue_arguments)
 
-    def _create_producer(self, task_id, channel):
-        self._create_binding(task_id)(channel).declare()
-        return self.Producer(channel, exchange=self.exchange,
+    def _create_producer(self, task_id, connection):
+        self._create_binding(task_id)(connection.default_channel).declare()
+        return self.Producer(connection, exchange=self.exchange,
                              routing_key=task_id.replace("-", ""),
                              serializer=self.serializer)
 
@@ -94,12 +94,7 @@ class AMQPBackend(BaseDictBackend):
 
     def _publish_result(self, connection, task_id, meta):
         # cache single channel
-        if connection._default_channel is not None and \
-                connection._default_channel.connection is None:
-            connection.maybe_close_channel(connection._default_channel)
-        channel = connection.default_channel
-
-        self._create_producer(task_id, channel).publish(meta)
+        self._create_producer(task_id, connection).publish(meta)
 
     def revive(self, channel):
         pass