Move AgentStatusCheckWorker to PeriodicWorker

Renames the AgentStatusCheckWorker class to PeriodicWorker
and moves it into the worker module since there isn't anything
agent-specific about it and it can be used for other periodic
jobs server side.

TrivialFix
Change-Id: Ic7a55ef534f64e6bfc60ae38bb0e139a0078510b

neutron/db/agentschedulers_db.py

@@ -21,7 +21,6 @@ from neutron_lib import constants
 from oslo_config import cfg
 from oslo_log import log as logging
 import oslo_messaging
-from oslo_service import loopingcall
 from oslo_utils import timeutils
 from sqlalchemy import orm
 from sqlalchemy.orm import exc
@@ -72,37 +71,6 @@ AGENTS_SCHEDULER_OPTS = [
 cfg.CONF.register_opts(AGENTS_SCHEDULER_OPTS)
 
 
-class AgentStatusCheckWorker(neutron_worker.NeutronWorker):
-
-    def __init__(self, check_func, interval, initial_delay):
-        super(AgentStatusCheckWorker, self).__init__(worker_process_count=0)
-
-        self._check_func = check_func
-        self._loop = None
-        self._interval = interval
-        self._initial_delay = initial_delay
-
-    def start(self):
-        super(AgentStatusCheckWorker, self).start()
-        if self._loop is None:
-            self._loop = loopingcall.FixedIntervalLoopingCall(self._check_func)
-        self._loop.start(interval=self._interval,
-                         initial_delay=self._initial_delay)
-
-    def wait(self):
-        if self._loop is not None:
-            self._loop.wait()
-
-    def stop(self):
-        if self._loop is not None:
-            self._loop.stop()
-
-    def reset(self):
-        self.stop()
-        self.wait()
-        self.start()
-
-
 class AgentSchedulerDbMixin(agents_db.AgentDbMixin):
     """Common class for agent scheduler mixins."""
 
@@ -148,9 +116,8 @@ class AgentSchedulerDbMixin(agents_db.AgentDbMixin):
         # neutron server first starts. random to offset multiple servers
         initial_delay = random.randint(interval, interval * 2)
 
-        check_worker = AgentStatusCheckWorker(function, interval,
-                                              initial_delay)
-
+        check_worker = neutron_worker.PeriodicWorker(function, interval,
+                                                     initial_delay)
         self.add_worker(check_worker)
 
     def agent_dead_limit_seconds(self):

neutron/tests/unit/db/test_agentschedulers_db.py

@@ -29,7 +29,6 @@ from neutron.api.rpc.handlers import dhcp_rpc
 from neutron.api.rpc.handlers import l3_rpc
 from neutron.api.v2 import attributes
 from neutron.common import constants as n_const
-from neutron.common import utils
 from neutron import context
 from neutron.db import agents_db
 from neutron.db import agentschedulers_db
@@ -40,7 +39,6 @@ from neutron.extensions import dhcpagentscheduler
 from neutron.extensions import l3agentscheduler
 from neutron import manager
 from neutron.plugins.common import constants as service_constants
-from neutron.tests import base
 from neutron.tests.common import helpers
 from neutron.tests import fake_notifier
 from neutron.tests import tools
@@ -1453,31 +1451,6 @@ class OvsDhcpAgentNotifierTestCase(test_agent.AgentDBTestMixIn,
         self.assertTrue(self._is_schedule_network_called(device_id))
 
 
-class AgentStatusCheckWorkerTestCase(base.BaseTestCase):
-
-    def test_agent_worker_lifecycle(self):
-        check_function = mock.Mock()
-        worker = agentschedulers_db.AgentStatusCheckWorker(
-            check_function, interval=1, initial_delay=1)
-        self.addCleanup(worker.stop)
-        worker.wait()
-        self.assertFalse(check_function.called)
-        worker.start()
-        utils.wait_until_true(
-            lambda: check_function.called,
-            timeout=5,
-            exception=RuntimeError("check_function not called"))
-        worker.stop()
-        check_function.reset_mock()
-        worker.wait()
-        self.assertFalse(check_function.called)
-        worker.reset()
-        utils.wait_until_true(
-            lambda: check_function.called,
-            timeout=5,
-            exception=RuntimeError("check_function not called"))
-
-
 class OvsL3AgentNotifierTestCase(test_l3.L3NatTestCaseMixin,
                                  test_agent.AgentDBTestMixIn,
                                  AgentSchedulerTestMixIn,

neutron/tests/unit/test_worker.py

@@ -0,0 +1,44 @@
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import mock
+
+from neutron.common import utils
+from neutron.tests import base
+from neutron import worker as neutron_worker
+
+
+class PeriodicWorkerTestCase(base.BaseTestCase):
+
+    def test_periodic_worker_lifecycle(self):
+        check_function = mock.Mock()
+        worker = neutron_worker.PeriodicWorker(
+            check_function, interval=1, initial_delay=1)
+        self.addCleanup(worker.stop)
+        worker.wait()
+        self.assertFalse(check_function.called)
+        worker.start()
+        utils.wait_until_true(
+            lambda: check_function.called,
+            timeout=5,
+            exception=RuntimeError("check_function not called"))
+        worker.stop()
+        check_function.reset_mock()
+        worker.wait()
+        self.assertFalse(check_function.called)
+        worker.reset()
+        utils.wait_until_true(
+            lambda: check_function.called,
+            timeout=5,
+            exception=RuntimeError("check_function not called"))

neutron/worker.py

@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from oslo_service import loopingcall
 from oslo_service import service
 
 from neutron.callbacks import events
@@ -90,3 +91,35 @@ class NeutronWorker(service.ServiceBase):
     def start(self):
         if self.worker_process_count > 0:
             registry.notify(resources.PROCESS, events.AFTER_INIT, self.start)
+
+
+class PeriodicWorker(NeutronWorker):
+    """A worker that runs a function at a fixed interval."""
+
+    def __init__(self, check_func, interval, initial_delay):
+        super(PeriodicWorker, self).__init__(worker_process_count=0)
+
+        self._check_func = check_func
+        self._loop = None
+        self._interval = interval
+        self._initial_delay = initial_delay
+
+    def start(self):
+        super(PeriodicWorker, self).start()
+        if self._loop is None:
+            self._loop = loopingcall.FixedIntervalLoopingCall(self._check_func)
+        self._loop.start(interval=self._interval,
+                         initial_delay=self._initial_delay)
+
+    def wait(self):
+        if self._loop is not None:
+            self._loop.wait()
+
+    def stop(self):
+        if self._loop is not None:
+            self._loop.stop()
+
+    def reset(self):
+        self.stop()
+        self.wait()
+        self.start()