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# -*- coding: utf-8 -*-
# daemon/pidfile.py
# Part of ‘python-daemon’, an implementation of PEP 3143.
#
# Copyright © 2008–2015 Ben Finney <ben+python@benfinney.id.au>
#
# This is free software: you may copy, modify, and/or distribute this work
# under the terms of the Apache License, version 2.0 as published by the
# Apache Software Foundation.
# No warranty expressed or implied. See the file ‘LICENSE.ASF-2’ for details.
""" Lockfile behaviour implemented via Unix PID files.
"""
from __future__ import (absolute_import, unicode_literals)
from lockfile.pidlockfile import PIDLockFile
class TimeoutPIDLockFile(PIDLockFile, object):
""" Lockfile with default timeout, implemented as a Unix PID file.
This uses the ``PIDLockFile`` implementation, with the
following changes:
* The `acquire_timeout` parameter to the initialiser will be
used as the default `timeout` parameter for the `acquire`
method.
"""
def __init__(self, path, acquire_timeout=None, *args, **kwargs):
""" Set up the parameters of a TimeoutPIDLockFile.
:param path: Filesystem path to the PID file.
:param acquire_timeout: Value to use by default for the
`acquire` call.
:return: ``None``.
"""
self.acquire_timeout = acquire_timeout
super(TimeoutPIDLockFile, self).__init__(path, *args, **kwargs)
def acquire(self, timeout=None, *args, **kwargs):
""" Acquire the lock.
:param timeout: Specifies the timeout; see below for valid
values.
:return: ``None``.
The `timeout` defaults to the value set during
initialisation with the `acquire_timeout` parameter. It is
passed to `PIDLockFile.acquire`; see that method for
details.
"""
if timeout is None:
timeout = self.acquire_timeout
super(TimeoutPIDLockFile, self).acquire(timeout, *args, **kwargs)
# Local variables:
# coding: utf-8
# mode: python
# End:
# vim: fileencoding=utf-8 filetype=python :
|
