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24 lines
621 B
Python
24 lines
621 B
Python
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"""
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Singleton is a creational design pattern, which ensures that only
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one object of its kind exists and provides a single point of access
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to it for any other code.
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"""
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from threading import Lock
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class SingletonMetaclass(type):
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"""
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This is a thread-safe implementation of Singleton.
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"""
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_instances = {}
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_lock: Lock = Lock()
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def __call__(cls, *args, **kwargs):
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with cls._lock:
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if cls not in cls._instances:
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cls._instances[cls] = super(SingletonMetaclass, cls).__call__(
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*args, **kwargs
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)
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return cls._instances[cls]
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