Merge "Fix incompatiablity between apscheduler and eventlet"

watcher/common/scheduling.py

@@ -16,16 +16,22 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import eventlet
+
 from apscheduler import events
-from apscheduler.executors.pool import BasePoolExecutor
+from apscheduler.executors import pool as pool_executor
 from apscheduler.schedulers import background
+
 import futurist
+
 from oslo_service import service
 
+from watcher import eventlet as eventlet_helper
+
 job_events = events
 
 
-class GreenThreadPoolExecutor(BasePoolExecutor):
+class GreenThreadPoolExecutor(pool_executor.BasePoolExecutor):
     """Green thread pool
 
     An executor that runs jobs in a green thread pool.
@@ -43,16 +49,25 @@ executors = {
 }
 
 
-class BackgroundSchedulerService(service.ServiceBase,
-                                 background.BackgroundScheduler):
-    def __init__(self, gconfig={}, **options):
+class BackgroundSchedulerService(
+        service.ServiceBase, background.BackgroundScheduler):
+    def __init__(self, gconfig=None, **options):
+        self.should_patch = eventlet_helper.is_patched()
         if options is None:
             options = {'executors': executors}
         else:
             if 'executors' not in options.keys():
                 options['executors'] = executors
-        super(BackgroundSchedulerService, self).__init__(
-            gconfig, **options)
+        super().__init__(gconfig or {}, **options)
+
+    def _main_loop(self):
+        if self.should_patch:
+            # NOTE(sean-k-mooney): is_patched and monkey_patch form
+            # watcher.eventlet check a non thread local variable to early out
+            # as we do not use eventlet_helper.patch() here to ensure
+            # eventlet.monkey_patch() is actually called.
+            eventlet.monkey_patch()
+        super()._main_loop()
 
     def start(self):
         """Start service."""

watcher/tests/common/test_scheduling.py

@@ -0,0 +1,68 @@
+# 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.
+from unittest import mock
+
+import eventlet
+
+from apscheduler.schedulers import background
+
+from watcher.common import scheduling
+from watcher import eventlet as eventlet_helper
+from watcher.tests import base
+
+
+class TestSchedulerMonkeyPatching(base.BaseTestCase):
+
+    def setUp(self):
+        super().setUp()
+        self.started = False
+        self.test_scheduler = scheduling.BackgroundSchedulerService()
+        self.addCleanup(self._cleanup_scheduler)
+
+    def _cleanup_scheduler(self):
+        if self.started:
+            self.test_scheduler.shutdown()
+            self.started = False
+
+    def _start_scheduler(self):
+        self.test_scheduler.start()
+        self.started = True
+
+    @mock.patch.object(scheduling.BackgroundSchedulerService, 'start')
+    def test_scheduler_start(self, mock_start):
+        self.test_scheduler.start()
+        mock_start.assert_called_once_with()
+
+    @mock.patch.object(scheduling.BackgroundSchedulerService, 'shutdown')
+    def test_scheduler_stop(self, mock_shutdown):
+        self._start_scheduler()
+        self.test_scheduler.stop()
+        mock_shutdown.assert_called_once_with()
+
+    @mock.patch.object(scheduling.BackgroundSchedulerService, '_main_loop')
+    def test_scheduler_main_loop(self, mock_main_loop):
+        self._start_scheduler()
+        mock_main_loop.assert_called_once_with()
+
+    @mock.patch.object(background.BackgroundScheduler, '_main_loop')
+    @mock.patch.object(eventlet, 'monkey_patch')
+    def test_main_loop_is_monkey_patched(
+            self, mock_monky_patch, mock_main_loop):
+        self.test_scheduler._main_loop()
+        self.assertEqual(
+            eventlet_helper.is_patched(), self.test_scheduler.should_patch)
+        mock_monky_patch.assert_called_once_with()
+        mock_main_loop.assert_called_once_with()
+
+    def test_scheduler_should_patch(self):
+        self.assertEqual(
+            eventlet_helper.is_patched(), self.test_scheduler.should_patch)