#!/usr/bin/python
# coding=utf-8
#
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
# pylint: disable=consider-using-with
# pylint: disable=unspecified-encoding
import contextlib
import fcntl
import os
def setup_lock(lockfile_path):
lock_file_dir = os.path.dirname(lockfile_path)
if lock_file_dir and not os.path.exists(lock_file_dir):
os.makedirs(lock_file_dir)
fd = open(lockfile_path, 'a+')
# waiting till lock is acquired
fcntl.flock(fd, fcntl.LOCK_EX)
fd.seek(0, 0)
fd.truncate()
fd.write(str(os.getpid()))
fd.flush()
return fd
def release_lock(fd):
fcntl.flock(fd.fileno(), fcntl.LOCK_UN)
fd.close()
@contextlib.contextmanager
def acquire_lock(lockfile_path):
"""
Usage:
with acquire_lock():
... do something ...
"""
fd = setup_lock(lockfile_path)
try:
yield
finally:
release_lock(fd)
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