openstack/oslo.utils
Code Issues Proposed changes

eventletutils: Fix behavior discrepency when reusing Events

Browse Source 
The threading.Event object allows calling set() multiple times, but
the eventlet.Event object only permits send() to be called once,
before a reset() is required to reuse the Event.

Calling eventletutils.Event.set() multiple times triggers an
AssertionError from eventlet.Event.  This change resets the underlying
eventlet.Event if the set() method had already been called previously,
and ensures the eventletutils.Event behaves the same as the
threading.Event.

Change-Id: If761b237266bbfe7e65c56e152074b5d1ccac74b
This commit is contained in:
John Eckersberg 2018-04-04 12:45:27 -04:00
parent da8d3c3bbc
commit 82678918aa
2 changed files with 13 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
oslo_utils/eventletutils.py
View File

@ -159,6 +159,9 @@ class _Event(object):
isSet = is_set
def set(self):
if self._set:
self._event.reset()
self._set = True
self._event.send(True)

12
oslo_utils/tests/test_eventletutils.py
View File

@ -123,8 +123,8 @@ class EventletUtilsTest(test_base.BaseTestCase):
eventletutils.warn_eventlet_not_patched,
['blah.blah'])
@mock.patch('oslo_utils.eventletutils._Event.clear')
def test_event_api_compat(self, mock_clear):
@mock.patch('oslo_utils.eventletutils._eventlet')
def test_event_api_compat(self, mock_eventlet):
with mock.patch('oslo_utils.eventletutils.is_monkey_patched',
return_value=True):
e_event = eventletutils.Event()
@ -142,3 +142,11 @@ class EventletUtilsTest(test_base.BaseTestCase):
for method in public_methods:
self.assertTrue(hasattr(e_event, method))
# Ensure set() allows multiple invocations, same as in
# threading implementation. Must call reset on underlying
# Event before reusing it
e_event.set()
self.assertEqual(0, mock_eventlet.event.Event().reset.call_count)
e_event.set()
self.assertEqual(1, mock_eventlet.event.Event().reset.call_count)