c49594a62f
The context manager in the executor fit only for the blocking executor. Even the dispatcher needs to run code before and after the application callback, eventlet and future executors have to run the pre/post code into the main thread and can run the callback into an other thread, and that force them to run __enter__ and __exit__ manually and deal the exception path. This change adds a helper object instead of the context manager. It is designed to be explicit on what must be executed before and after the callback and what can be done in a thread or not. All the executor code is now in the impl_pooledexecutor.py and use the futures "PoolExecutor" API. This use futurist to provide a eventlet and aioeventlet futures friendly object. Change-Id: I8cd7640f36beeda47560e3c82671bad3530e38d1
113 lines
4.1 KiB
Python
113 lines
4.1 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
# Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
|
|
#
|
|
# 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 collections
|
|
import threading
|
|
|
|
from concurrent import futures
|
|
from oslo.config import cfg
|
|
from oslo.utils import excutils
|
|
|
|
from oslo_messaging._executors import base
|
|
|
|
_pool_opts = [
|
|
cfg.IntOpt('rpc_thread_pool_size',
|
|
default=64,
|
|
help='Size of RPC thread pool.'),
|
|
]
|
|
|
|
|
|
class PooledExecutor(base.ExecutorBase):
|
|
"""A message executor which integrates with threads.
|
|
|
|
A message process that polls for messages from a dispatching thread and
|
|
on reception of an incoming message places the message to be processed in
|
|
a thread pool to be executed at a later time.
|
|
"""
|
|
|
|
# NOTE(harlowja): if eventlet is being used and the thread module is monkey
|
|
# patched this should/is supposed to work the same as the eventlet based
|
|
# executor.
|
|
|
|
# NOTE(harlowja): Make it somewhat easy to change this via
|
|
# inheritance (since there does exist other executor types that could be
|
|
# used/tried here).
|
|
_executor_cls = futures.ThreadPoolExecutor
|
|
_event_cls = threading.Event
|
|
_lock_cls = threading.Lock
|
|
_thread_cls = threading.Thread
|
|
|
|
def __init__(self, conf, listener, dispatcher):
|
|
super(PooledExecutor, self).__init__(conf, listener, dispatcher)
|
|
self.conf.register_opts(_pool_opts)
|
|
self._poller = None
|
|
self._executor = None
|
|
self._tombstone = self._event_cls()
|
|
self._incomplete = collections.deque()
|
|
self._mutator = self._lock_cls()
|
|
|
|
@excutils.forever_retry_uncaught_exceptions
|
|
def _runner(self):
|
|
while not self._tombstone.is_set():
|
|
incoming = self.listener.poll()
|
|
if incoming is None:
|
|
continue
|
|
callback = self.dispatcher(incoming, self._executor_callback)
|
|
try:
|
|
fut = self._executor.submit(callback.run)
|
|
except RuntimeError:
|
|
# This is triggered when the executor has been shutdown...
|
|
#
|
|
# TODO(harlowja): should we put whatever we pulled off back
|
|
# since when this is thrown it means the executor has been
|
|
# shutdown already??
|
|
callback.done()
|
|
return
|
|
else:
|
|
with self._mutator:
|
|
self._incomplete.append(fut)
|
|
# Run the other post processing of the callback when done...
|
|
fut.add_done_callback(lambda f: callback.done())
|
|
|
|
def start(self):
|
|
if self._executor is None:
|
|
self._executor = self._executor_cls(self.conf.rpc_thread_pool_size)
|
|
self._tombstone.clear()
|
|
if self._poller is None or not self._poller.is_alive():
|
|
self._poller = self._thread_cls(target=self._runner)
|
|
self._poller.daemon = True
|
|
self._poller.start()
|
|
|
|
def stop(self):
|
|
if self._executor is not None:
|
|
self._executor.shutdown(wait=False)
|
|
self._tombstone.set()
|
|
self.listener.stop()
|
|
|
|
def wait(self):
|
|
# TODO(harlowja): this method really needs a timeout.
|
|
if self._poller is not None:
|
|
self._tombstone.wait()
|
|
self._poller.join()
|
|
self._poller = None
|
|
if self._executor is not None:
|
|
with self._mutator:
|
|
incomplete_fs = list(self._incomplete)
|
|
self._incomplete.clear()
|
|
if incomplete_fs:
|
|
futures.wait(incomplete_fs, return_when=futures.ALL_COMPLETED)
|
|
self._executor = None
|