Source code for taskflow.conductors.backends.impl_nonblocking
# -*- coding: utf-8 -*-
# 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 futurist
from taskflow.conductors.backends import impl_executor
from taskflow.utils import threading_utils as tu
[docs]
class NonBlockingConductor(impl_executor.ExecutorConductor):
"""Non-blocking conductor that processes job(s) using a thread executor.
NOTE(harlowja): A custom executor factory can be provided via keyword
argument ``executor_factory``, if provided it will be
invoked at
:py:meth:`~taskflow.conductors.base.Conductor.run` time
with one positional argument (this conductor) and it must
return a compatible `executor`_ which can be used
to submit jobs to. If ``None`` is a provided a thread pool
backed executor is selected by default (it will have
an equivalent number of workers as this conductors
simultaneous job count).
.. _executor: https://docs.python.org/dev/library/\
concurrent.futures.html#executor-objects
"""
MAX_SIMULTANEOUS_JOBS = tu.get_optimal_thread_count()
"""
Default maximum number of jobs that can be in progress at the same time.
"""
def _default_executor_factory(self):
max_simultaneous_jobs = self._max_simultaneous_jobs
if max_simultaneous_jobs <= 0:
max_workers = tu.get_optimal_thread_count()
else:
max_workers = max_simultaneous_jobs
return futurist.ThreadPoolExecutor(max_workers=max_workers)
def __init__(self, name, jobboard,
persistence=None, engine=None,
engine_options=None, wait_timeout=None,
log=None, max_simultaneous_jobs=MAX_SIMULTANEOUS_JOBS,
executor_factory=None):
super(NonBlockingConductor, self).__init__(
name, jobboard,
persistence=persistence, engine=engine,
engine_options=engine_options, wait_timeout=wait_timeout,
log=log, max_simultaneous_jobs=max_simultaneous_jobs)
if executor_factory is None:
self._executor_factory = self._default_executor_factory
else:
if not callable(executor_factory):
raise ValueError("Provided keyword argument 'executor_factory'"
" must be callable")
self._executor_factory = executor_factory