Use SleepFixture instead of mocking _ThreadingEvent.wait

Recently, the _ThreadingEvent class in oslo.service was removed [1] and
our unit test patching is preventing us from moving to a newer version
of oslo.service [2].

We have patching of the _ThreadingEvent.wait method to bypass the sleep
time in the looping call of RetryDecorator, which adds several seconds
to the run time of unit tests.

This changes things to use the new SleepFixture from oslo.service
instead.

Depends-On: https://review.openstack.org/616371

[1] I62e9f1a7cde8846be368fbec58b8e0825ce02079
[2] https://review.openstack.org/615676

Change-Id: I45dd7602068eb0ce1331cfefd5a0cf6418bc8e88

lower-constraints.txt

@@ -89,7 +89,7 @@ oslo.privsep==1.23.0
 oslo.reports==1.18.0
 oslo.rootwrap==5.8.0
 oslo.serialization==2.18.0
-oslo.service==1.24.0
+oslo.service==1.33.0
 oslo.utils==3.37.0
 oslo.versionedobjects==1.33.3
 oslo.vmware==2.17.0

nova/tests/unit/compute/test_compute_mgr.py

@@ -27,6 +27,7 @@ import netaddr
 from oslo_log import log as logging
 import oslo_messaging as messaging
 from oslo_serialization import jsonutils
+from oslo_service import fixture as service_fixture
 from oslo_utils.fixture import uuidsentinel as uuids
 from oslo_utils import timeutils
 from oslo_utils import uuidutils
@@ -6444,6 +6445,7 @@ class ComputeManagerBuildInstanceTestCase(test.NoDBTestCase):
         """Tests that _try_deallocate_network will retry calling
         _deallocate_network on keystone ConnectFailure errors up to a limit.
         """
+        self.useFixture(service_fixture.SleepFixture())
         deallocate_network_mock.side_effect = \
             keystone_exception.connection.ConnectFailure
         req_networks = objects.NetworkRequestList(

nova/tests/unit/virt/disk/mount/test_api.py

@@ -13,6 +13,7 @@
 #    under the License.
 
 import mock
+from oslo_service import fixture as service_fixture
 
 from nova import test
 from nova.virt.disk.mount import api
@@ -29,6 +30,11 @@ MAP_PARTITION = "/dev/mapper/nullp77"
 
 
 class MountTestCase(test.NoDBTestCase):
+    def setUp(self):
+        super(MountTestCase, self).setUp()
+        # Make RetryDecorator not actually sleep on retries
+        self.useFixture(service_fixture.SleepFixture())
+
     def _test_map_dev(self, partition):
         mount = api.Mount(mock.sentinel.image, mock.sentinel.mount_dir)
         mount.device = ORIG_DEVICE

nova/tests/unit/virt/libvirt/test_guest.py

@@ -17,6 +17,7 @@
 import sys
 
 import mock
+from oslo_service import fixture as service_fixture
 from oslo_utils import encodeutils
 import six
 import testtools
@@ -46,6 +47,9 @@ class GuestTestCase(test.NoDBTestCase):
         self.domain = mock.Mock(spec=fakelibvirt.virDomain)
         self.guest = libvirt_guest.Guest(self.domain)
 
+        # Make RetryDecorator not actually sleep on retries
+        self.useFixture(service_fixture.SleepFixture())
+
     def test_repr(self):
         self.domain.ID.return_value = 99
         self.domain.UUIDString.return_value = "UUID"

requirements.txt

@@ -49,7 +49,7 @@ oslo.messaging>=6.3.0 # Apache-2.0
 oslo.policy>=1.35.0 # Apache-2.0
 oslo.privsep>=1.23.0 # Apache-2.0
 oslo.i18n>=3.15.3 # Apache-2.0
-oslo.service!=1.28.1,>=1.24.0 # Apache-2.0
+oslo.service>=1.33.0 # Apache-2.0
 rfc3986>=0.3.1 # Apache-2.0
 oslo.middleware>=3.31.0 # Apache-2.0
 psutil>=3.2.2 # BSD