56 lines
1.9 KiB
Python
56 lines
1.9 KiB
Python
# -*- coding: utf-8 -*-
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (C) 2013 Yahoo! Inc. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import logging
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import multiprocessing
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import six
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import threading
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import types
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from taskflow.utils import lock_utils
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LOG = logging.getLogger(__name__)
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def get_optimal_thread_count():
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"""Try to guess optimal thread count for current system."""
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try:
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return multiprocessing.cpu_count() + 1
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except NotImplementedError:
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# NOTE(harlowja): apparently may raise so in this case we will
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# just setup two threads since its hard to know what else we
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# should do in this situation.
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return 2
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class ThreadSafeMeta(type):
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"""Metaclass that adds locking to all pubic methods of a class"""
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def __new__(cls, name, bases, attrs):
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for attr_name, attr_value in six.iteritems(attrs):
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if isinstance(attr_value, types.FunctionType):
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if attr_name[0] != '_':
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attrs[attr_name] = lock_utils.locked(attr_value)
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return super(ThreadSafeMeta, cls).__new__(cls, name, bases, attrs)
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def __call__(cls, *args, **kwargs):
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instance = super(ThreadSafeMeta, cls).__call__(*args, **kwargs)
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if not hasattr(instance, '_lock'):
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instance._lock = threading.RLock()
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return instance
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