trivial: Remove 'run_once' helper

This should have been removed when we removed the placement code in
change I4181f39dea7eb10b84e6f5057938767b3e422aff.

Change-Id: If5808075d853341bf274f35b7fcf0e0712f8f77a
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>

2 files changed, 0 insertions, 141 deletions

diff --git a/nova/tests/unit/test_utils.py b/nova/tests/unit/test_utils.py
index b3e10e856a..23a080f6a2 100644
--- a/nova/tests/unit/test_utils.py
+++ b/nova/tests/unit/test_utils.py
@@ -1045,104 +1045,6 @@ class GetEndpointTestCase(test.NoDBTestCase):
         self.adap.get_endpoint.assert_called_once_with()
 
 
-class RunOnceTests(test.NoDBTestCase):
-
-    fake_logger = mock.MagicMock()
-
-    @utils.run_once("already ran once", fake_logger)
-    def dummy_test_func(self, fail=False):
-        if fail:
-            raise ValueError()
-        return True
-
-    def setUp(self):
-        super(RunOnceTests, self).setUp()
-        self.dummy_test_func.reset()
-        RunOnceTests.fake_logger.reset_mock()
-
-    def test_wrapped_funtions_called_once(self):
-        self.assertFalse(self.dummy_test_func.called)
-        result = self.dummy_test_func()
-        self.assertTrue(result)
-        self.assertTrue(self.dummy_test_func.called)
-
-        # assert that on second invocation no result
-        # is returned and that the logger is invoked.
-        result = self.dummy_test_func()
-        RunOnceTests.fake_logger.assert_called_once()
-        self.assertIsNone(result)
-
-    def test_wrapped_funtions_called_once_raises(self):
-        self.assertFalse(self.dummy_test_func.called)
-        self.assertRaises(ValueError, self.dummy_test_func, fail=True)
-        self.assertTrue(self.dummy_test_func.called)
-
-        # assert that on second invocation no result
-        # is returned and that the logger is invoked.
-        result = self.dummy_test_func()
-        RunOnceTests.fake_logger.assert_called_once()
-        self.assertIsNone(result)
-
-    def test_wrapped_funtions_can_be_reset(self):
-        # assert we start with a clean state
-        self.assertFalse(self.dummy_test_func.called)
-        result = self.dummy_test_func()
-        self.assertTrue(result)
-
-        self.dummy_test_func.reset()
-        # assert we restored a clean state
-        self.assertFalse(self.dummy_test_func.called)
-        result = self.dummy_test_func()
-        self.assertTrue(result)
-
-        # assert that we never called the logger
-        RunOnceTests.fake_logger.assert_not_called()
-
-    def test_reset_calls_cleanup(self):
-        mock_clean = mock.Mock()
-
-        @utils.run_once("already ran once", self.fake_logger,
-                        cleanup=mock_clean)
-        def f():
-            pass
-
-        f()
-        self.assertTrue(f.called)
-
-        f.reset()
-        self.assertFalse(f.called)
-        mock_clean.assert_called_once_with()
-
-    def test_clean_is_not_called_at_reset_if_wrapped_not_called(self):
-        mock_clean = mock.Mock()
-
-        @utils.run_once("already ran once", self.fake_logger,
-                        cleanup=mock_clean)
-        def f():
-            pass
-
-        self.assertFalse(f.called)
-
-        f.reset()
-        self.assertFalse(f.called)
-        self.assertFalse(mock_clean.called)
-
-    def test_reset_works_even_if_cleanup_raises(self):
-        mock_clean = mock.Mock(side_effect=ValueError())
-
-        @utils.run_once("already ran once", self.fake_logger,
-                        cleanup=mock_clean)
-        def f():
-            pass
-
-        f()
-        self.assertTrue(f.called)
-
-        self.assertRaises(ValueError, f.reset)
-        self.assertFalse(f.called)
-        mock_clean.assert_called_once_with()
-
-
 class TestResourceClassNormalize(test.NoDBTestCase):
 
     def test_normalize_name(self):
diff --git a/nova/utils.py b/nova/utils.py
index 914d5516ff..50222092d2 100644
--- a/nova/utils.py
+++ b/nova/utils.py
@@ -1079,49 +1079,6 @@ else:
             yield [stack.enter_context(c) for c in contexts]
 
 
-def run_once(message, logger, cleanup=None):
-    """This is a utility function decorator to ensure a function
-    is run once and only once in an interpreter instance.
-    The decorated function object can be reset by calling its
-    reset function. All exceptions raised by the wrapped function,
-    logger and cleanup function will be propagated to the caller.
-    """
-    def outer_wrapper(func):
-        @functools.wraps(func)
-        def wrapper(*args, **kwargs):
-            if not wrapper.called:
-                # Note(sean-k-mooney): the called state is always
-                # updated even if the wrapped function completes
-                # by raising an exception. If the caller catches
-                # the exception it is their responsibility to call
-                # reset if they want to re-execute the wrapped function.
-                try:
-                    return func(*args, **kwargs)
-                finally:
-                    wrapper.called = True
-            else:
-                logger(message)
-
-        wrapper.called = False
-
-        def reset(wrapper, *args, **kwargs):
-            # Note(sean-k-mooney): we conditionally call the
-            # cleanup function if one is provided only when the
-            # wrapped function has been called previously. We catch
-            # and reraise any exception that may be raised and update
-            # the called state in a finally block to ensure its
-            # always updated if reset is called.
-            try:
-                if cleanup and wrapper.called:
-                    return cleanup(*args, **kwargs)
-            finally:
-                wrapper.called = False
-
-        wrapper.reset = functools.partial(reset, wrapper)
-        return wrapper
-    return outer_wrapper
-
-
 def normalize_rc_name(rc_name):
     """Normalize a resource class name to standard form."""
     if rc_name is None: