[AIM] Don't queue registry callbacks (3 of 4)

Now that no GBP or Neutron REST APIs are called from within
transactions (except during validation), there is no longer any need
to delay calling in-process callbacks that send notifictions until
after the transaction commits. Therefore, the monkey-path and
associated code for queing of these callbacks is eliminated.

A follow-up patch will eliminate the queuing of notifications sent
directly by plugin code.

Change-Id: I7f184c4903e0a771b024a2e1d89e3165e5fd3450

gbpservice/neutron/plugins/ml2plus/patch_neutron.py

@@ -84,66 +84,6 @@ setattr(ovo_rpc._ObjectChangeHandler, '_is_session_semantic_violated',
         new_is_session_semantic_violated)
 
 
-from neutron_lib.callbacks import registry
-
-from gbpservice.network.neutronv2 import local_api
-
-
-def notify(resource, event, trigger, **kwargs):
-    if 'context' in kwargs:
-        session = kwargs['context'].session
-    else:
-        session = get_current_session()
-
-    txn = None
-    if session:
-        txn = local_api.get_outer_transaction(session.transaction)
-    local_api.send_or_queue_registry_notification(
-        session, txn, resource, event, trigger, **kwargs)
-
-
-registry.notify = notify
-
-
-from neutron_lib.callbacks import events
-from neutron_lib.callbacks import exceptions
-from oslo_log import log as logging
-
-
-LOG = logging.getLogger(__name__)
-
-
-def _notify_loop(resource, event, trigger, **kwargs):
-    """The notification loop."""
-    errors = []
-    callbacks = kwargs.pop('callbacks', None)
-    if not callbacks:
-        callbacks = list(registry._get_callback_manager()._callbacks[
-            resource].get(event, {}).items())
-    LOG.debug("Notify callbacks %s for %s, %s", callbacks, resource, event)
-    for callback_id, callback in callbacks:
-        try:
-            callback(resource, event, trigger, **kwargs)
-        except Exception as e:
-            abortable_event = (
-                event.startswith(events.BEFORE) or
-                event.startswith(events.PRECOMMIT)
-            )
-            if not abortable_event:
-                LOG.exception("Error during notification for "
-                              "%(callback)s %(resource)s, %(event)s",
-                              {'callback': callback_id,
-                               'resource': resource, 'event': event})
-            else:
-                LOG.error("Callback %(callback)s raised %(error)s",
-                          {'callback': callback_id, 'error': e})
-            errors.append(exceptions.NotificationError(callback_id, e))
-    return errors
-
-
-original_notify_loop = registry._get_callback_manager()._notify_loop
-
-
 from inspect import isclass
 from inspect import isfunction
 from inspect import ismethod
@@ -258,9 +198,13 @@ exc_filters.LOG.exception = exc_filters.LOG.debug
 from neutron.db import models_v2
 from neutron.plugins.ml2 import db as ml2_db
 from neutron.plugins.ml2 import models
+from oslo_log import log as logging
 from sqlalchemy.orm import exc
 
 
+LOG = logging.getLogger(__name__)
+
+
 # REVISIT: This method is patched here to remove calls to
 # with_lockmode('update') from the two queries it makes. It is no
 # longer used directly by any code in this repository, was no longer