celery.messaging._exchanges_declared is now a set

celery/messaging.py

@@ -24,7 +24,7 @@ extract_msg_options = lambda d: dict(zip(MSG_OPTIONS, get_msg_options(d)))
 default_queue = conf.get_queues()[conf.DEFAULT_QUEUE]
 
 _queues_declared = False
-_exchanges_declared = {}
+_exchanges_declared = set()
 
 
 class TaskPublisher(Publisher):
@@ -44,9 +44,12 @@ class TaskPublisher(Publisher):
             consumers = get_consumer_set(self.connection)
             consumers.close()
             _queues_declared = True
+        self.declare()
+
+    def declare(self):
         if self.exchange not in _exchanges_declared:
-            self.declare()
-            _exchanges_declared[self.exchange] = True
+            super(TaskPublisher, self).declare()
+            _exchanges_declared.add(self.exchange)
 
     def delay_task(self, task_name, task_args=None, task_kwargs=None,
             countdown=None, eta=None, task_id=None, taskset_id=None, **kwargs):