Advertisement
Not a member of Pastebin yet?
Sign Up,
it unlocks many cool features!
- # -*- coding: utf-8 -*-
- """The MIT License (MIT)
- Copyright (c) 2015 Alexander Chekunkov
- Permission is hereby granted, free of charge, to any person obtaining a copy
- of this software and associated documentation files (the "Software"), to deal
- in the Software without restriction, including without limitation the rights
- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- copies of the Software, and to permit persons to whom the Software is
- furnished to do so, subject to the following conditions:
- The above copyright notice and this permission notice shall be included in all
- copies or substantial portions of the Software.
- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- SOFTWARE.
- """
- from threading import RLock
- import fcntl
- class FileBasedRLock(object):
- """Reentrant lock based on lock file.
- Expected to provide lock:
- - per thread: it uses threading.RLock in acquire() and release() methods;
- - per process: it uses lock file to synchronize several processes.
- """
- def __init__(self, filename):
- self._lock_file = open(filename, 'w')
- self.rlock = RLock()
- self.count = 0
- def acquire(self):
- self.rlock.acquire()
- if self.count == 0:
- fcntl.flock(self._lock_file, fcntl.LOCK_EX)
- self.count += 1
- def release(self):
- self.count -= 1
- if self.count == 0:
- fcntl.flock(self._lock_file, fcntl.LOCK_UN)
- self.rlock.release()
- def __enter__(self):
- self.acquire()
- return self
- def __exit__(self, exc_type, exc_val, exc_tb):
- self.release()
- def __del__(self):
- self._lock_file.close()
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement