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35 lines
789 B
Python
35 lines
789 B
Python
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#
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# Copyright (C) 2018 Satoru SATOH <ssato @ redhat.com>
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# License: MIT
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#
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r"""Singleton class
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.. versionadded:: 0.9.8
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- Add to make a kind of manager instancne later to manage plugins.
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"""
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from __future__ import absolute_import
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import threading
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class Singleton(object):
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"""Singleton utilizes __new__ special method.
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.. note:: Inherited classes are equated with base class inherit this.
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"""
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__instance = None
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__lock = threading.RLock()
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def __new__(cls):
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if cls.__instance is None:
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cls.__lock.acquire()
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if cls.__instance is None:
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try:
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cls.__instance = object.__new__(cls)
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finally:
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cls.__lock.release()
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return cls.__instance
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# vim:sw=4:ts=4:et:
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