setup_rpc should be the last thing in __init__ method

[yong sheng gong]

if setup_rpc is too early, the dispatch maybe dispatch the rpc message to an unready agent. take ovs plugin agent for instance,
after setup_rpc is called, many of the initialization work are still needed to be done. If the message is coming during this time, the instance will not be fully initialized:

    def __init__(self, integ_br, tun_br, local_ip,
                 bridge_mappings, root_helper,
                 polling_interval, tunnel_types=None,
                 veth_mtu=None, l2_population=False,
                 minimize_polling=False,
                 ovsdb_monitor_respawn_interval=(
                     constants.DEFAULT_OVSDBMON_RESPAWN)):
        '''Constructor.

        :param integ_br: name of the integration bridge.
        :param tun_br: name of the tunnel bridge.
        :param local_ip: local IP address of this hypervisor.
        :param bridge_mappings: mappings from physical network name to bridge.
        :param root_helper: utility to use when running shell cmds.
        :param polling_interval: interval (secs) to poll DB.
        :param tunnel_types: A list of tunnel types to enable support for in
               the agent. If set, will automatically set enable_tunneling to
               True.
        :param veth_mtu: MTU size for veth interfaces.
        :param minimize_polling: Optional, whether to minimize polling by
               monitoring ovsdb for interface changes.
        :param ovsdb_monitor_respawn_interval: Optional, when using polling
               minimization, the number of seconds to wait before respawning
               the ovsdb monitor.
        '''
        self.veth_mtu = veth_mtu
        self.root_helper = root_helper
        self.available_local_vlans = set(xrange(q_const.MIN_VLAN_TAG,
                                                q_const.MAX_VLAN_TAG))
        self.tunnel_types = tunnel_types or []
        self.l2_pop = l2_population
        self.agent_state = {
            'binary': 'neutron-openvswitch-agent',
            'host': cfg.CONF.host,
            'topic': q_const.L2_AGENT_TOPIC,
            'configurations': {'bridge_mappings': bridge_mappings,
                               'tunnel_types': self.tunnel_types,
                               'tunneling_ip': local_ip,
                               'l2_population': self.l2_pop},
            'agent_type': q_const.AGENT_TYPE_OVS,
            'start_flag': True}

        # Keep track of int_br's device count for use by _report_state()
        self.int_br_device_count = 0

        self.int_br = ovs_lib.OVSBridge(integ_br, self.root_helper)
        self.setup_rpc()
        self.setup_integration_br()
        self.setup_physical_bridges(bridge_mappings)
        self.local_vlan_map = {}
        self.tun_br_ofports = {constants.TYPE_GRE: {},
                               constants.TYPE_VXLAN: {}}

        self.polling_interval = polling_interval
        self.minimize_polling = minimize_polling
        self.ovsdb_monitor_respawn_interval = ovsdb_monitor_respawn_interval

        if tunnel_types:
            self.enable_tunneling = True
        else:
            self.enable_tunneling = False
        self.local_ip = local_ip
        self.tunnel_count = 0
        self.vxlan_udp_port = cfg.CONF.AGENT.vxlan_udp_port
        self._check_ovs_version()
        if self.enable_tunneling:
            self.setup_tunnel_br(tun_br)
        # Collect additional bridges to monitor
        self.ancillary_brs = self.setup_ancillary_bridges(integ_br, tun_br)

        # Security group agent supprot
        self.sg_agent = OVSSecurityGroupAgent(self.context,
                                              self.plugin_rpc,
                                              root_helper)
        # Initialize iteration counter
        self.iter_num = 0

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/60805

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/60805
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=f691ebe03916a78cbf18017d628a28b17f147700
Submitter: Jenkins
Branch: master

commit f691ebe03916a78cbf18017d628a28b17f147700
Author: Yong Sheng Gong <email address hidden>
Date: Mon Dec 9 21:01:17 2013 +0800

    move rpc_setup to the last step of __init__

    rpc setup should be the last stuff in agent initialization
    so that the rcp message handler(the agent instance itself)
    can have a fully initialized agent instance.

    Change-Id: I58c966e2c8ee92c307b565932e867b5d1ec73b67
    Closes-Bug: #1259088