locking.py

from django.core.cache import cache
from contextlib import contextmanager
from datetime import timedelta


class LockUnavailable(Exception):
    pass


class Lock(object):

    def __init__(self, lock_id):
        self.id = 'lock:%s' % lock_id

    def acquire(self):
        return cache.add(self.id, 'true', timedelta(minutes=2).seconds)

    def release(self):
        cache.delete(self.id)


@contextmanager
def lock(*ids):

    acquired_locks = []

    try:
        for i in ids:
            a = Lock(i)
            if a.acquire():
                acquired_locks.append(a)
            else:
                raise LockUnavailable(id)

            yield True
    finally:
        [r.release() for r in acquired_locks]