Fix full executor warning on noname executor

The warning log assumed all executors has a name. Our centrally managed
executors has but not the adhoc ones causing a stack trace in the
compute manager power_sync periodics.

Change-Id: I04620364439a6c377f5b8f8f68cbdd3c62c44562
Signed-off-by: Balazs Gibizer <gibi@redhat.com>

nova/tests/unit/compute/test_compute_mgr.py

@@ -4139,15 +4139,20 @@ class ComputeManagerUnitTestCase(test.NoDBTestCase,
 
     @mock.patch.object(objects.InstanceList, 'get_by_host')
     def test_sync_power_states(self, mock_get):
+        # Force an RLock as the test uses a sync executor as the task is run
+        # on the caller thread and both the caller and the task needs the lock
+        self.compute._syncs_in_progress_lock = threading.RLock()
         instance = mock.Mock()
         mock_get.return_value = [instance]
-        with mock.patch('nova.utils.spawn_on') as mock_spawn:
+        with mock.patch.object(
+            self.compute, '_query_driver_power_state_and_sync'
+        ) as mock_sync:
             self.compute._sync_power_states(mock.sentinel.context)
-            mock_get.assert_called_with(mock.sentinel.context,
-                                        self.compute.host, expected_attrs=[],
-                                        use_slave=True)
-            mock_spawn.assert_called_once_with(
-                self.compute._sync_power_executor, mock.ANY, instance)
+
+        mock_get.assert_called_with(mock.sentinel.context,
+                                    self.compute.host, expected_attrs=[],
+                                    use_slave=True)
+        mock_sync.assert_called_once_with(mock.sentinel.context, instance)
 
     @mock.patch('nova.objects.InstanceList.get_by_host', new=mock.Mock())
     @mock.patch('nova.compute.manager.ComputeManager.'

nova/tests/unit/test_utils.py

@@ -1559,6 +1559,41 @@ class SpawnOnTestCase(test.NoDBTestCase):
             'nova.tests.unit.test_utils.SpawnOnTestCase.'
             'test_spawn_on_warns_on_full_executor.cell_worker', task)
 
+    @mock.patch.object(
+        utils, 'concurrency_mode_threading', new=mock.Mock(return_value=True))
+    @mock.patch.object(utils.LOG, 'warning')
+    def test_spawn_on_warns_on_full_executor_noname(self, mock_warning):
+        # Ensure we have executor for a single task only at a time
+        executor = utils.create_executor(max_workers=1)
+
+        work = threading.Event()
+        started = threading.Event()
+
+        # let the blocked tasks finish after the test case so that the leaked
+        # thread check is not triggered during cleanup
+        self.addCleanup(work.set)
+
+        def task():
+            started.set()
+            work.wait()
+
+        # Start two tasks that will wait, the first will execute the second
+        # will wait in the queue
+        utils.spawn_on(executor, task)
+        utils.spawn_on(executor, task)
+        # wait for the first task to consume the single executor thread
+        started.wait()
+        # start one more task to trigger the fullness check.
+        utils.spawn_on(executor, task)
+
+        # We expect that spawn_on will warn due to the second task being is
+        # waiting in the queue, and no idle worker thread exists.
+        mock_warning.assert_called_once_with(
+            'The %s pool does not have free threads so the task %s will be '
+            'queued. If this happens repeatedly then the size of the pool is '
+            'too small for the load or there are stuck threads filling the '
+            'pool.', 'unknown', task)
+
 
 class ExecutorStatsTestCase(test.NoDBTestCase):
 

nova/utils.py

@@ -616,7 +616,7 @@ def spawn_on(
             "The %s pool does not have free threads so the task %s will be "
             "queued. If this happens repeatedly then the size of the pool is "
             "too small for the load or there are stuck threads filling the "
-            "pool.", executor.name, func)
+            "pool.", getattr(executor, "name", "unknown"), func)
 
     _context = common_context.get_current()
     profiler_info = _serialize_profile_info()