From d8e68c365b86d35b3f83e8fca89c38130c93dbd2 Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Wed, 3 Dec 2014 01:46:51 +0100 Subject: [PATCH] Add a new aioeventlet executor The new executor supports trollius coroutines, explicit asynchronous programming, in addition to eventlet greenthreads, implicit asynchronous programming. The new AsyncioEventletExecutor class is based on the EventletExecutor class and so it is compatible with it. The aioeventlet executor can be used to replace the eventlet executor, but it requires an aioeventlet event loop running in the thread running the executor (usually the main thread). See AsyncioEventletExecutor docstring for an example how to setup such event loop. The aioeventlet module implements the asyncio API (PEP 3156) on top of eventlet, see aioeventlet documentation: http://aioeventlet.readthedocs.org/ The change adds an unit test with an endpoint implemented as a trollius coroutine. The executor is not supported on Python 3 yet because of eventlet issues with monkey patching. Implements: blueprint greenio-executor Change-Id: I7a78ed998719a703077232726f66d882463b1297 --- oslo_messaging/_executors/impl_aioeventlet.py | 75 ++++++++++++ oslo_messaging/_executors/impl_eventlet.py | 6 +- .../tests/executors/test_executor.py | 111 +++++++++++++++--- requirements.txt | 4 + setup.cfg | 1 + 5 files changed, 181 insertions(+), 16 deletions(-) create mode 100644 oslo_messaging/_executors/impl_aioeventlet.py diff --git a/oslo_messaging/_executors/impl_aioeventlet.py b/oslo_messaging/_executors/impl_aioeventlet.py new file mode 100644 index 000000000..d0fc4aa31 --- /dev/null +++ b/oslo_messaging/_executors/impl_aioeventlet.py @@ -0,0 +1,75 @@ +# Copyright 2014 eNovance. +# +# Licensed under the Apache License, Version 2.0 (the "License"); you may +# not use this file except in compliance with the License. You may obtain +# a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT +# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the +# License for the specific language governing permissions and limitations +# under the License. + +import aioeventlet +import trollius + +from oslo_messaging._executors import impl_eventlet + + +class AsyncioEventletExecutor(impl_eventlet.EventletExecutor): + + """A message executor which integrates with eventlet and trollius. + + The executor is based on eventlet executor and so is compatible with it. + The executor supports trollius coroutines, explicit asynchronous + programming, in addition to eventlet greenthreads, implicit asynchronous + programming. + + To use the executor, an aioeventlet event loop must the running in the + thread executing the executor (usually the main thread). Example of code to + setup and run an aioeventlet event loop for the executor (in the main + thread): + + import aioeventlet + import trollius + + policy = aioeventlet.EventLoopPolicy() + trollius.set_event_loop_policy(policy) + + def run_loop(loop): + loop.run_forever() + loop.close() + + # Get the aioeventlet event loop (create it if needed) + loop = trollius.get_event_loop() + + # run the event loop in a new greenthread, + # close it when it is done + eventlet.spawn(run_loop, loop) + """ + + def __init__(self, conf, listener, dispatcher): + super(AsyncioEventletExecutor, self).__init__(conf, listener, + dispatcher) + self._loop = None + + def start(self): + # check that the event loop is an aioeventlet event loop + loop = trollius.get_event_loop() + if not isinstance(loop, aioeventlet.EventLoop): + raise RuntimeError("need an aioeventlet event loop") + self._loop = loop + + super(AsyncioEventletExecutor, self).start() + + def _coroutine_wrapper(self, func, *args, **kw): + result = func(*args, **kw) + if trollius.iscoroutine(result): + result = aioeventlet.yield_future(result, loop=self._loop) + return result + + def _dispatch(self, incoming): + ctx = self.dispatcher(incoming, self._coroutine_wrapper) + impl_eventlet.spawn_with(ctxt=ctx, pool=self._greenpool) diff --git a/oslo_messaging/_executors/impl_eventlet.py b/oslo_messaging/_executors/impl_eventlet.py index 555ae0364..3333fe713 100644 --- a/oslo_messaging/_executors/impl_eventlet.py +++ b/oslo_messaging/_executors/impl_eventlet.py @@ -82,6 +82,9 @@ class EventletExecutor(base.PooledExecutorBase): 'behavior. In the future, we will raise a ' 'RuntimeException in this case.') + def _dispatch(self, incoming): + spawn_with(ctxt=self.dispatcher(incoming), pool=self._greenpool) + def start(self): if self._thread is not None: return @@ -92,8 +95,7 @@ class EventletExecutor(base.PooledExecutorBase): while self._running: incoming = self.listener.poll() if incoming is not None: - spawn_with(ctxt=self.dispatcher(incoming), - pool=self._greenpool) + self._dispatch(incoming) except greenlet.GreenletExit: return diff --git a/oslo_messaging/tests/executors/test_executor.py b/oslo_messaging/tests/executors/test_executor.py index cb321ddef..4e3ec517f 100644 --- a/oslo_messaging/tests/executors/test_executor.py +++ b/oslo_messaging/tests/executors/test_executor.py @@ -17,6 +17,12 @@ import contextlib import threading +# eventlet 0.16 with monkey patching does not work yet on Python 3, +# so make aioeventlet, eventlet and trollius import optional +try: + import aioeventlet +except ImportError: + aioeventlet = None try: import eventlet except ImportError: @@ -24,7 +30,16 @@ except ImportError: import mock import testscenarios import testtools +try: + import trollius +except ImportError: + pass + +try: + from oslo_messaging._executors import impl_aioeventlet +except ImportError: + impl_aioeventlet = None from oslo_messaging._executors import impl_blocking try: from oslo_messaging._executors import impl_eventlet @@ -46,42 +61,110 @@ class TestExecutor(test_utils.BaseTestCase): if impl_eventlet is not None: impl.append( ('eventlet', dict(executor=impl_eventlet.EventletExecutor))) + if impl_aioeventlet is not None: + impl.append( + ('aioeventlet', + dict(executor=impl_aioeventlet.AsyncioEventletExecutor))) cls.scenarios = testscenarios.multiply_scenarios(impl) @staticmethod - def _run_in_thread(executor): - def thread(): - executor.start() - executor.wait() - thread = threading.Thread(target=thread) + def _run_in_thread(target, executor): + thread = threading.Thread(target=target, args=(executor,)) thread.daemon = True thread.start() thread.join(timeout=30) def test_executor_dispatch(self): - callback = mock.MagicMock(return_value='result') + if impl_aioeventlet is not None: + aioeventlet_class = impl_aioeventlet.AsyncioEventletExecutor + else: + aioeventlet_class = None + is_aioeventlet = (self.executor == aioeventlet_class) + + if is_aioeventlet: + policy = aioeventlet.EventLoopPolicy() + trollius.set_event_loop_policy(policy) + self.addCleanup(trollius.set_event_loop_policy, None) + + def run_loop(loop): + loop.run_forever() + loop.close() + trollius.set_event_loop(None) + + def run_executor(executor): + # create an event loop in the executor thread + loop = trollius.new_event_loop() + trollius.set_event_loop(loop) + eventlet.spawn(run_loop, loop) + + # run the executor + executor.start() + executor.wait() + + # stop the event loop: run_loop() will close it + loop.stop() + + @trollius.coroutine + def simple_coroutine(value): + yield None + raise trollius.Return(value) + + endpoint = mock.MagicMock(return_value=simple_coroutine('result')) + event = eventlet.event.Event() + else: + def run_executor(executor): + executor.start() + executor.wait() + + endpoint = mock.MagicMock(return_value='result') class Dispatcher(object): + def __init__(self, endpoint): + self.endpoint = endpoint + self.result = "not set" + @contextlib.contextmanager - def __call__(self, incoming): - yield lambda: callback(incoming.ctxt, incoming.message) + def __call__(self, incoming, executor_callback=None): + if executor_callback is not None: + def callback(): + result = executor_callback(self.endpoint, + incoming.ctxt, + incoming.message) + self.result = result + return result + yield callback + event.send() + else: + def callback(): + result = self.endpoint(incoming.ctxt, incoming.message) + self.result = result + return result + yield callback listener = mock.Mock(spec=['poll']) - executor = self.executor(self.conf, listener, Dispatcher()) + dispatcher = Dispatcher(endpoint) + executor = self.executor(self.conf, listener, dispatcher) incoming_message = mock.MagicMock(ctxt={}, message={'payload': 'data'}) def fake_poll(timeout=None): - if listener.poll.call_count == 1: - return incoming_message - executor.stop() + if is_aioeventlet: + if listener.poll.call_count == 1: + return incoming_message + event.wait() + executor.stop() + else: + if listener.poll.call_count == 1: + return incoming_message + executor.stop() listener.poll.side_effect = fake_poll - self._run_in_thread(executor) + self._run_in_thread(run_executor, executor) - callback.assert_called_once_with({}, {'payload': 'data'}) + endpoint.assert_called_once_with({}, {'payload': 'data'}) + self.assertEqual(dispatcher.result, 'result') TestExecutor.generate_scenarios() diff --git a/requirements.txt b/requirements.txt index 352b14aa8..e6747b09e 100644 --- a/requirements.txt +++ b/requirements.txt @@ -29,3 +29,7 @@ oslo.middleware>=0.3.0 # Apache-2.0 # for the futures based executor futures>=2.1.6 + +# needed by the aioeventlet executor +aioeventlet>=0.4 +trollius>=1.0 diff --git a/setup.cfg b/setup.cfg index 3f94cb942..0e191c441 100644 --- a/setup.cfg +++ b/setup.cfg @@ -42,6 +42,7 @@ oslo.messaging.drivers = fake = oslo_messaging._drivers.impl_fake:FakeDriver oslo.messaging.executors = + aioeventlet = oslo_messaging._executors.impl_aioeventlet:AsyncioEventletExecutor blocking = oslo_messaging._executors.impl_blocking:BlockingExecutor eventlet = oslo_messaging._executors.impl_eventlet:EventletExecutor threading = oslo_messaging._executors.impl_thread:ThreadExecutor