Skip to content
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
63 lines (49 sloc) 1.54 KB
# -*- coding: utf-8 -*-
from contextlib import contextmanager
from redis import Redis
class Lock(object):
"""Lock implemented on top of redis."""
def __init__(self, name, timeout=60, db=0):
Create, if necessary the lock variable in redis.
We utilize the ``blpop`` command and its blocking behavior.
The ``_key`` variable is used to check, whether the mutex exists or not,
while the ``_mutex`` variable is the actual mutex.
self._key = 'lock:name:%s' % name
self._mutex = 'lock:mutex:%s' % name
self._timeout = timeout
self._r = Redis(db=1)
def mutex_key(self):
return self._mutex
def lock(self):
Lock and block.
RuntimeError, in case of synchronization issues.
res = self._r.blpop(self._mutex, self._timeout)
if res is None:
raise RuntimeError
def unlock(self):
self._r.rpush(self._mutex, 1)
def _init_mutex(self):
Initialize the mutex, if necessary.
Use a separate key to check for the existence of the "mutex",
so that we can utilize ``getset``, which is atomic.
exists = self._r.getset(self._key, 1)
if exists is None:
self._r.lpush(self._mutex, 1)
def lock(name, timeout=60):
"""Lock on name using redis."""
l = Lock(name, timeout)
You can’t perform that action at this time.