Rework zmq setup and cleanup

Register config options at import time and remove the register_opts()
function. It seems this isn't being used.

Add accessor methods for ZMQ_CTXT and matchmaker so that they are
lazily created rather than created at import time.

Remove the rpc_zmq_matchmaker override in the tests since
MatchMakerLocalhost is the default anyway. We were setting it with
an incorrect value, but only after the matchmaker had already been
created.

Change-Id: I2520252c64d70e4c4903e34d07952fed43e70ebe

openstack/common/rpc/impl_zmq.py

@@ -76,9 +76,9 @@ zmq_opts = [
 ]
 
 
-# These globals are defined in register_opts(conf),
-# a mandatory initialization call
-CONF = None
+CONF = cfg.CONF
+CONF.register_opts(zmq_opts)
+
 ZMQ_CTX = None  # ZeroMQ Context, must be global.
 matchmaker = None  # memoized matchmaker object
 
@@ -113,7 +113,7 @@ class ZmqSocket(object):
     """
 
     def __init__(self, addr, zmq_type, bind=True, subscribe=None):
-        self.sock = ZMQ_CTX.socket(zmq_type)
+        self.sock = _get_ctxt().socket(zmq_type)
         self.addr = addr
         self.type = zmq_type
         self.subscriptions = []
@@ -685,7 +685,7 @@ def _multi_send(method, context, topic, msg, timeout=None, serialize=True,
     conf = CONF
     LOG.debug(_("%(msg)s") % {'msg': ' '.join(map(pformat, (topic, msg)))})
 
-    queues = matchmaker.queues(topic)
+    queues = _get_matchmaker().queues(topic)
     LOG.debug(_("Sending message(s) to: %s"), queues)
 
     # Don't stack if we have no matchmaker results
@@ -753,32 +753,26 @@ def notify(conf, context, topic, msg, **kwargs):
 def cleanup():
     """Clean up resources in use by implementation."""
     global ZMQ_CTX
-    global matchmaker
-    matchmaker = None
-    ZMQ_CTX.term()
+    if ZMQ_CTX:
+        ZMQ_CTX.term()
     ZMQ_CTX = None
 
-
-def register_opts(conf):
-    """Registration of options for this driver."""
-    #NOTE(ewindisch): ZMQ_CTX and matchmaker
-    # are initialized here as this is as good
-    # an initialization method as any.
-
-    # We memoize through these globals
-    global ZMQ_CTX
     global matchmaker
-    global CONF
+    matchmaker = None
 
-    if not CONF:
-        conf.register_opts(zmq_opts)
-        CONF = conf
-    # Don't re-set, if this method is called twice.
+
+def _get_ctxt():
+    global ZMQ_CTX
     if not ZMQ_CTX:
-        ZMQ_CTX = zmq.Context(conf.rpc_zmq_contexts)
+        ZMQ_CTX = zmq.Context(CONF.rpc_zmq_contexts)
+    return ZMQ_CTX
+
+
+def _get_matchmaker():
+    global matchmaker
     if not matchmaker:
         # rpc_zmq_matchmaker should be set to a 'module.Class'
-        mm_path = conf.rpc_zmq_matchmaker.split('.')
+        mm_path = CONF.rpc_zmq_matchmaker.split('.')
         mm_module = '.'.join(mm_path[:-1])
         mm_class = mm_path[-1]
 
@@ -791,6 +785,4 @@ def register_opts(conf):
         mm_impl = importutils.import_module(mm_module)
         mm_constructor = getattr(mm_impl, mm_class)
         matchmaker = mm_constructor()
-
-
-register_opts(cfg.CONF)
+    return matchmaker

tests/unit/rpc/test_zmq.py

@@ -59,7 +59,6 @@ class _RpcZmqBaseTestCase(common.BaseRpcTestCase):
         self.config(rpc_zmq_bind_address='127.0.0.1')
         self.config(rpc_zmq_host='127.0.0.1')
         self.config(rpc_response_timeout=5)
-        self.config(rpc_zmq_matchmaker='mod_matchmaker.MatchMakerLocalhost')
 
         # We'll change this if we detect no daemon running.
         ipc_dir = FLAGS.rpc_zmq_ipc_dir