42 lines
1.3 KiB
Python
42 lines
1.3 KiB
Python
# Copyright (c) 2020 Matt Martz <matt@sivel.net>
|
|
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
|
|
|
|
from __future__ import annotations
|
|
|
|
from functools import wraps
|
|
|
|
|
|
def lock_decorator(attr='missing_lock_attr', lock=None):
|
|
'''This decorator is a generic implementation that allows you
|
|
to either use a pre-defined instance attribute as the location
|
|
of the lock, or to explicitly pass a lock object.
|
|
|
|
This code was implemented with ``threading.Lock`` in mind, but
|
|
may work with other locks, assuming that they function as
|
|
context managers.
|
|
|
|
When using ``attr``, the assumption is the first argument to
|
|
the wrapped method, is ``self`` or ``cls``.
|
|
|
|
Examples:
|
|
|
|
@lock_decorator(attr='_callback_lock')
|
|
def send_callback(...):
|
|
|
|
@lock_decorator(lock=threading.Lock())
|
|
def some_method(...):
|
|
'''
|
|
def outer(func):
|
|
@wraps(func)
|
|
def inner(*args, **kwargs):
|
|
# Python2 doesn't have ``nonlocal``
|
|
# assign the actual lock to ``_lock``
|
|
if lock is None:
|
|
_lock = getattr(args[0], attr)
|
|
else:
|
|
_lock = lock
|
|
with _lock:
|
|
return func(*args, **kwargs)
|
|
return inner
|
|
return outer
|