Do not use threading.Event

Waiting on a threading.Event with eventlet can cause busy looping via
epoll_wait, see related bug for more details.

Change-Id: I007613058a2d21d1712c02fa6d1602b63705c1ab
Related-bug: #1518430

lower-constraints.txt

@@ -48,7 +48,7 @@ oslo.log==3.36.0
 oslo.middleware==3.31.0
 oslo.serialization==2.18.0
 oslo.service==1.24.0
-oslo.utils==3.33.0
+oslo.utils==3.37.0
 oslotest==3.2.0
 Paste==2.0.2
 PasteDeploy==1.5.0

oslo_messaging/_drivers/amqp1_driver/controller.py

@@ -35,6 +35,7 @@ import threading
 import time
 import uuid
 
+from oslo_utils import eventletutils
 import proton
 import pyngus
 from six import iteritems
@@ -85,7 +86,7 @@ class SubscribeTask(Task):
         self._subscriber_id = listener.id
         self._in_queue = listener.incoming
         self._service = SERVICE_NOTIFY if notifications else SERVICE_RPC
-        self._wakeup = threading.Event()
+        self._wakeup = eventletutils.Event()
 
     def wait(self):
         self._wakeup.wait()
@@ -112,7 +113,7 @@ class SendTask(Task):
         self.service = SERVICE_NOTIFY if notification else SERVICE_RPC
         self.timer = None
         self._retry = None if retry is None or retry < 0 else retry
-        self._wakeup = threading.Event()
+        self._wakeup = eventletutils.Event()
         self._error = None
         self._sender = None
 

oslo_messaging/_drivers/amqpdriver.py

@@ -19,6 +19,7 @@ import time
 import uuid
 
 import cachetools
+from oslo_utils import eventletutils
 from oslo_utils import timeutils
 from six import moves
 
@@ -49,7 +50,7 @@ class MessageOperationsHandler(object):
         self.name = "%s (%s)" % (name, hex(id(self)))
         self._tasks = moves.queue.Queue()
 
-        self._shutdown = threading.Event()
+        self._shutdown = eventletutils.Event()
         self._shutdown_thread = threading.Thread(
             target=self._process_in_background)
         self._shutdown_thread.daemon = True
@@ -270,8 +271,8 @@ class AMQPListener(base.PollStyleListener):
         self.conn = conn
         self.msg_id_cache = rpc_amqp._MsgIdCache()
         self.incoming = []
-        self._shutdown = threading.Event()
+        self._shutdown = eventletutils.Event()
-        self._shutoff = threading.Event()
+        self._shutoff = eventletutils.Event()
         self._obsolete_reply_queues = ObsoleteReplyQueuesCache()
         self._message_operations_handler = MessageOperationsHandler(
             "AMQPListener")
@@ -434,7 +435,7 @@ class ReplyWaiter(object):
 
         self.conn.declare_direct_consumer(reply_q, self)
 
-        self._thread_exit_event = threading.Event()
+        self._thread_exit_event = eventletutils.Event()
         self._thread = threading.Thread(target=self.poll)
         self._thread.daemon = True
         self._thread.start()

oslo_messaging/_drivers/impl_fake.py

@@ -18,6 +18,7 @@ import threading
 import time
 
 from oslo_serialization import jsonutils
+from oslo_utils import eventletutils
 from six import moves
 
 import oslo_messaging
@@ -49,7 +50,7 @@ class FakeListener(base.PollStyleListener):
         self._exchange_manager = exchange_manager
         self._targets = targets
         self._pool = pool
-        self._stopped = threading.Event()
+        self._stopped = eventletutils.Event()
 
         # NOTE(sileht): Ensure that all needed queues exists even the listener
         # have not been polled yet

oslo_messaging/_drivers/impl_kafka.py

@@ -347,7 +347,7 @@ class KafkaListener(base.PollStyleListener):
 
     def __init__(self, conn):
         super(KafkaListener, self).__init__()
-        self._stopped = threading.Event()
+        self._stopped = eventletutils.Event()
         self.conn = conn
         self.incoming_queue = []
 

oslo_messaging/rpc/dispatcher.py

@@ -24,6 +24,8 @@ import threading
 
 import six
 
+from oslo_utils import eventletutils
+
 from oslo_messaging import _utils as utils
 from oslo_messaging import dispatcher
 from oslo_messaging import serializer as msg_serializer
@@ -249,7 +251,7 @@ class RPCDispatcher(dispatcher.DispatcherBase):
         # is executing if it runs for some time. The thread will wait
         # for the event to be signaled, which we do explicitly below
         # after dispatching the method call.
-        completion_event = threading.Event()
+        completion_event = eventletutils.Event()
         watchdog_thread = threading.Thread(target=self._watchdog,
                                            args=(completion_event, incoming))
         if incoming.client_timeout:

oslo_messaging/tests/drivers/test_amqp_driver.py

@@ -27,6 +27,7 @@ import threading
 import time
 import uuid
 
+from oslo_utils import eventletutils
 from oslo_utils import importutils
 from six import moves
 from string import Template
@@ -75,8 +76,8 @@ class _ListenerThread(threading.Thread):
         self._msg_ack = msg_ack
         self.messages = moves.queue.Queue()
         self.daemon = True
-        self.started = threading.Event()
+        self.started = eventletutils.Event()
-        self._done = threading.Event()
+        self._done = eventletutils.Event()
         self.start()
         self.started.wait()
 
@@ -1146,7 +1147,7 @@ class TestLinkRecovery(_AmqpBrokerTestCase):
         self._addrs = {'unicast.test-topic': 2,
                        'broadcast.test-topic.all': 2,
                        'exclusive.test-topic.server': 2}
-        self._recovered = threading.Event()
+        self._recovered = eventletutils.Event()
         self._count = 0
 
         def _on_active(link):
@@ -2100,7 +2101,7 @@ class FakeBroker(threading.Thread):
 
         self._connections = {}
         self._sources = {}
-        self._pause = threading.Event()
+        self._pause = eventletutils.Event()
         # count of messages forwarded, by messaging pattern
         self.direct_count = 0
         self.topic_count = 0

oslo_messaging/tests/drivers/test_impl_rabbit.py

@@ -23,6 +23,7 @@ import fixtures
 import kombu
 import kombu.transport.memory
 from oslo_serialization import jsonutils
+from oslo_utils import eventletutils
 import testscenarios
 
 import oslo_messaging
@@ -49,7 +50,7 @@ class TestHeartbeat(test_utils.BaseTestCase):
                                 fake_logger, heartbeat_side_effect=None,
                                 info=None):
 
-        event = threading.Event()
+        event = eventletutils.Event()
 
         def heartbeat_check(rate=2):
             event.set()

oslo_messaging/tests/rpc/test_server.py

@@ -19,6 +19,7 @@ import warnings
 import eventlet
 import fixtures
 from oslo_config import cfg
+from oslo_utils import eventletutils
 from six.moves import mock
 import testscenarios
 
@@ -61,7 +62,7 @@ class ServerSetupMixin(object):
 
     class ServerController(object):
         def __init__(self):
-            self.stopped = threading.Event()
+            self.stopped = eventletutils.Event()
 
         def stop(self, ctxt):
             self.stopped.set()
@@ -704,11 +705,11 @@ class TestServerLocking(test_utils.BaseTestCase):
         # Test that if 2 threads call a method simultaneously, both will wait,
         # but only 1 will call the underlying executor method.
 
-        start_event = threading.Event()
+        start_event = eventletutils.Event()
-        finish_event = threading.Event()
+        finish_event = eventletutils.Event()
 
-        running_event = threading.Event()
+        running_event = eventletutils.Event()
-        done_event = threading.Event()
+        done_event = eventletutils.Event()
 
         _runner = [None]
 
@@ -734,7 +735,7 @@ class TestServerLocking(test_utils.BaseTestCase):
         runner = _runner[0]
         waiter = start2 if runner == start1 else start2
 
-        waiter_finished = threading.Event()
+        waiter_finished = eventletutils.Event()
         waiter.link(lambda _: waiter_finished.set())
 
         # At this point, runner is running start(), and waiter() is waiting for
@@ -783,8 +784,8 @@ class TestServerLocking(test_utils.BaseTestCase):
         # Ensure that if 2 threads wait for the completion of 'start', the
         # first will wait until complete_event is signalled, but the second
         # will continue
-        complete_event = threading.Event()
+        complete_event = eventletutils.Event()
-        complete_waiting_callback = threading.Event()
+        complete_waiting_callback = eventletutils.Event()
 
         start_state = self.server._states['start']
         old_wait_for_completion = start_state.wait_for_completion
@@ -801,7 +802,7 @@ class TestServerLocking(test_utils.BaseTestCase):
 
         # thread1 will wait for start to complete until we signal it
         thread1 = eventlet.spawn(self.server.stop)
-        thread1_finished = threading.Event()
+        thread1_finished = eventletutils.Event()
         thread1.link(lambda _: thread1_finished.set())
 
         self.server.start()
@@ -847,7 +848,7 @@ class TestServerLocking(test_utils.BaseTestCase):
         # Test that we generate a log message if we wait longer than
         # DEFAULT_LOG_AFTER
 
-        log_event = threading.Event()
+        log_event = eventletutils.Event()
         mock_log.warning.side_effect = lambda _, __: log_event.set()
 
         # Call stop without calling start. We should log a wait after 1 second
@@ -863,7 +864,7 @@ class TestServerLocking(test_utils.BaseTestCase):
         # Test that we generate a log message if we wait longer than
         # the number of seconds passed to log_after
 
-        log_event = threading.Event()
+        log_event = eventletutils.Event()
         mock_log.warning.side_effect = lambda _, __: log_event.set()
 
         # Call stop without calling start. We should log a wait after 1 second
@@ -879,7 +880,7 @@ class TestServerLocking(test_utils.BaseTestCase):
         # Test that we log a message after log_after seconds if we've also
         # specified an absolute timeout
 
-        log_event = threading.Event()
+        log_event = eventletutils.Event()
         mock_log.warning.side_effect = lambda _, __: log_event.set()
 
         # Call stop without calling start. We should log a wait after 1 second
@@ -904,7 +905,7 @@ class TestServerLocking(test_utils.BaseTestCase):
         # Start the server, which will also instantiate an executor
         self.server.start()
         self.server.stop()
-        shutdown_called = threading.Event()
+        shutdown_called = eventletutils.Event()
 
         # Patch the executor's stop method to be very slow
         def slow_shutdown(wait):

oslo_messaging/tests/utils.py

@@ -22,6 +22,7 @@
 import threading
 
 from oslo_config import cfg
+from oslo_utils import eventletutils
 from oslotest import base
 
 
@@ -63,8 +64,8 @@ class ServerThreadHelper(threading.Thread):
         super(ServerThreadHelper, self).__init__()
         self.daemon = True
         self._server = server
-        self._stop_event = threading.Event()
+        self._stop_event = eventletutils.Event()
-        self._start_event = threading.Event()
+        self._start_event = eventletutils.Event()
 
     def start(self):
         super(ServerThreadHelper, self).start()

requirements.txt

@@ -7,7 +7,7 @@ pbr!=2.1.0,>=2.0.0 # Apache-2.0
 futurist>=1.2.0 # Apache-2.0
 oslo.config>=5.2.0 # Apache-2.0
 oslo.log>=3.36.0 # Apache-2.0
-oslo.utils>=3.33.0 # Apache-2.0
+oslo.utils>=3.37.0 # Apache-2.0
 oslo.serialization!=2.19.1,>=2.18.0 # Apache-2.0
 oslo.service!=1.28.1,>=1.24.0 # Apache-2.0
 stevedore>=1.20.0 # Apache-2.0