Add wrapper for oslo.concurrency lockutils.ReaderWriterLock()

This is a follow up change to I168fffac8002f274a905cfd53ac4f6c9abe18803
which added a hackaround to enable our tests to pass with
fasteners>=0.15 which was upgraded recently as part of a
openstack/requirements update.

The ReaderWriterLock from fasteners (and thus lockutils) cannot work
correctly with eventlet patched code, so this adds a wrapper containing
the aforementioned hackaround along with a hacking check to do our best
to ensure that future use of ReaderWriterLock will be through the
wrapper.

Change-Id: Ia7bcb40a21a804c7bc6b74f501d95ce2a88b09b5

1 files changed, 20 insertions, 0 deletions

diff --git a/nova/tests/unit/test_hacking.py b/nova/tests/unit/test_hacking.py
index 1ed47e389f..03b7692217 100644
--- a/nova/tests/unit/test_hacking.py
+++ b/nova/tests/unit/test_hacking.py
@@ -1000,3 +1000,23 @@ class HackingTestCase(test.NoDBTestCase):
         self._assert_has_no_errors(
             code, checks.do_not_use_mock_class_as_new_mock_value,
             filename="nova/tests/unit/test_context.py")
+
+    def test_check_lockutils_rwlocks(self):
+        code = """
+                    lockutils.ReaderWriterLock()
+                    lockutils.ReaderWriterLock(condition_cls=MyClass)
+                    oslo_concurrency.lockutils.ReaderWriterLock()
+                    fasteners.ReaderWriterLock()
+                    fasteners.ReaderWriterLock(condition_cls=MyClass)
+               """
+        errors = [(x + 1, 0, 'N369') for x in range(5)]
+        self._assert_has_errors(
+            code, checks.check_lockutils_rwlocks, expected_errors=errors)
+
+        code = """
+                    nova.utils.ReaderWriterLock()
+                    utils.ReaderWriterLock()
+                    utils.ReaderWriterLock(condition_cls=MyClass)
+                    nova_utils.ReaderWriterLock()
+               """
+        self._assert_has_no_errors(code, checks.check_lockutils_rwlocks)