Ensures listener queues exist in fake driver

The fanout queues of the fake driver are created at the first executor
poll, but if we use eventlet executor and the fake driver, when the sender
delivers a fanout message before the first poll, the message goes to the
topic queue instead of the server fanout queue.

The changes fixes that by ensuring the all queues exists when the
listener is created.

Closes bug #1331453
Related-Bug: #1334798

Co-authored-by: Paul Michali <pcm@cisco.com>
Change-Id: I92e7c01dd87d634b741bbcaea92f48730fdd555e
(cherry picked from commit e582da68f4)
(cherry picked from commit 0cfafac246)

oslo/messaging/_drivers/impl_fake.py

@@ -45,6 +45,12 @@ class FakeListener(base.Listener):
         self._exchange_manager = exchange_manager
         self._targets = targets
 
+        # NOTE(sileht): Ensure that all needed queues exists even the listener
+        # have not been polled yet
+        for target in self._targets:
+            exchange = self._exchange_manager.get_exchange(target.exchange)
+            exchange.ensure_queue(target)
+
     def poll(self):
         while True:
             for target in self._targets:
@@ -65,6 +71,13 @@ class FakeExchange(object):
         self._topic_queues = {}
         self._server_queues = {}
 
+    def ensure_queue(self, target):
+        with self._queues_lock:
+            if target.server:
+                self._get_server_queue(target.topic, target.server)
+            else:
+                self._get_topic_queue(target.topic)
+
     def _get_topic_queue(self, topic):
         return self._topic_queues.setdefault(topic, [])