82 lines
2.4 KiB
Python
82 lines
2.4 KiB
Python
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# This file is part of Pebble.
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# Copyright (c) 2013-2022, Matteo Cafasso
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# Pebble is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License
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# as published by the Free Software Foundation,
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# either version 3 of the License, or (at your option) any later version.
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# Pebble is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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# You should have received a copy of the GNU Lesser General Public License
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# along with Pebble. If not, see <http://www.gnu.org/licenses/>.
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import signal
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import threading
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from functools import wraps
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from typing import Any, Callable
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_synchronized_lock = threading.Lock()
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def synchronized(*args):
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"""A synchronized function prevents two or more callers to interleave
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its execution preventing race conditions.
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The synchronized decorator accepts as optional parameter a Lock, RLock or
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Semaphore object which will be employed to ensure the function's atomicity.
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If no synchronization object is given, a single threading.Lock will be used.
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This implies that between different decorated function only one at a time
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will be executed.
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"""
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if callable(args[0]):
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return decorate_synchronized(args[0], _synchronized_lock)
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else:
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def wrap(function):
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return decorate_synchronized(function, args[0])
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return wrap
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def decorate_synchronized(function: Callable, lock: threading.Lock) -> Callable:
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@wraps(function)
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def wrapper(*args, **kwargs) -> Any:
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with lock:
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return function(*args, **kwargs)
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return wrapper
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def sighandler(signals: list) -> Callable:
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"""Sets the decorated function as signal handler of given *signals*.
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*signals* can be either a single signal or a list/tuple
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of multiple ones.
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"""
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def wrap(function):
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set_signal_handlers(signals, function)
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@wraps(function)
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def wrapper(*args, **kwargs):
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return function(*args, **kwargs)
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return wrapper
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return wrap
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def set_signal_handlers(signals: list, function: Callable):
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if isinstance(signals, (list, tuple)):
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for signum in signals:
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signal.signal(signum, function)
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else:
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signal.signal(signals, function)
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