lock.py 文件源码

def write_locked(*args, **kwargs):
    """Acquires & releases a write lock around call into decorated method.

    NOTE(harlowja): if no attribute name is provided then by default the
    attribute named '_lock' is looked for (this attribute is expected to be
    a :py:class:`.ReaderWriterLock` object) in the instance object this
    decorator is attached to.
    """

    def decorator(f):
        attr_name = kwargs.get('lock', '_lock')

        @six.wraps(f)
        def wrapper(self, *args, **kwargs):
            rw_lock = getattr(self, attr_name)
            with rw_lock.write_lock():
                return f(self, *args, **kwargs)

        return wrapper

    # This is needed to handle when the decorator has args or the decorator
    # doesn't have args, python is rather weird here...
    if kwargs or not args:
        return decorator
    else:
        if len(args) == 1:
            return decorator(args[0])
        else:
            return decorator