Merge "Fix SynchronousThreadPoolExecutorFixture mock of Future"

nova/tests/fixtures.py

@@ -1106,24 +1106,22 @@ class SpawnIsSynchronousFixture(fixtures.Fixture):
             'nova.utils.spawn', _FakeGreenThread))
 
 
-class SynchronousThreadPoolExecutorFixture(fixtures.Fixture):
-    """Make GreenThreadPoolExecutor.submit() synchronous.
+class _FakeExecutor(futurist.SynchronousExecutor):
+    def __init__(self, *args, **kwargs):
+        # Ignore kwargs (example: max_workers) that SynchronousExecutor
+        # does not support.
+        super(_FakeExecutor, self).__init__()
 
-    The function passed to submit() will be executed and a mock.Mock
-    object will be returned as the Future where Future.result() will
-    return the result of the call to the submitted function.
+
+class SynchronousThreadPoolExecutorFixture(fixtures.Fixture):
+    """Make GreenThreadPoolExecutor synchronous.
+
+    Replace the GreenThreadPoolExecutor with the SynchronousExecutor.
     """
     def setUp(self):
         super(SynchronousThreadPoolExecutorFixture, self).setUp()
-
-        def fake_submit(_self, fn, *args, **kwargs):
-            result = fn(*args, **kwargs)
-            future = mock.Mock(spec=futurist.Future)
-            future.return_value.result.return_value = result
-            return future
         self.useFixture(fixtures.MonkeyPatch(
-            'futurist.GreenThreadPoolExecutor.submit',
-            fake_submit))
+            'futurist.GreenThreadPoolExecutor', _FakeExecutor))
 
 
 class BannedDBSchemaOperations(fixtures.Fixture):

nova/tests/unit/compute/test_compute.py

@@ -1509,9 +1509,12 @@ class ComputeTestCase(BaseTestCase,
                       test_diagnostics.DiagnosticsComparisonMixin,
                       fake_resource_tracker.RTMockMixin):
     def setUp(self):
+        # This needs to go before we call setUp because the thread pool
+        # executor is created in ComputeManager.__init__, which is called
+        # during setUp.
+        self.useFixture(fixtures.SynchronousThreadPoolExecutorFixture())
         super(ComputeTestCase, self).setUp()
         self.useFixture(fixtures.SpawnIsSynchronousFixture())
-        self.useFixture(fixtures.SynchronousThreadPoolExecutorFixture())
 
         self.image_api = image_api.API()
         self.default_flavor = objects.Flavor.get_by_name(self.context,
@@ -6298,11 +6301,13 @@ class ComputeTestCase(BaseTestCase,
                     'resources': mock.sentinel.allocs,
                 }
             }
-            self.assertRaises(test.TestingException,
-                              self.compute.live_migration,
-                              c, dest=dest_host, block_migration=True,
-                              instance=instance, migration=migration,
-                              migrate_data=migrate_data)
+            # This call will not raise TestingException because if a task
+            # submitted to a thread executor raises, the exception will not be
+            # raised unless Future.result() is called.
+            self.compute.live_migration(
+                    c, dest=dest_host, block_migration=True,
+                    instance=instance, migration=migration,
+                    migrate_data=migrate_data)
             mock_setup.assert_called_once_with(c, instance, self.compute.host)
             mock_client.move_allocations.assert_called_once_with(
                 c, migration.uuid, instance.uuid)
@@ -6414,8 +6419,10 @@ class ComputeTestCase(BaseTestCase,
                                'cleanup') as mock_cleanup:
             mock_cleanup.side_effect = test.TestingException
 
-            self.assertRaises(test.TestingException,
-                self.compute.live_migration,
+            # This call will not raise TestingException because if a task
+            # submitted to a thread executor raises, the exception will not be
+            # raised unless Future.result() is called.
+            self.compute.live_migration(
                 c, dest, instance, False, migration, migrate_data)
 
         # ensure we have updated the instance and migration objects

nova/tests/unit/test_fixtures.py

@@ -18,6 +18,7 @@ import copy
 import sys
 
 import fixtures as fx
+import futurist
 import mock
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -414,6 +415,17 @@ class TestSpawnIsSynchronousFixture(testtools.TestCase):
         self.assertEqual(1, len(call_count))
 
 
+class TestSynchronousThreadPoolExecutorFixture(testtools.TestCase):
+    def test_submit_passes_through(self):
+        self.useFixture(fixtures.SynchronousThreadPoolExecutorFixture())
+        tester = mock.MagicMock()
+        executor = futurist.GreenThreadPoolExecutor()
+        future = executor.submit(tester.function, 'foo', bar='bar')
+        tester.function.assert_called_once_with('foo', bar='bar')
+        result = future.result()
+        self.assertEqual(tester.function.return_value, result)
+
+
 class TestBannedDBSchemaOperations(testtools.TestCase):
     def test_column(self):
         column = sqlalchemy.Column()