python-redis-lock 0.1.0

Lock context manager implemented via redis SETNX/BLPOP.

Lock context manager implemented via redis SETNX/BLPOP.

Interface targeted to be exactly like threading.Lock.

Usage

Because we don’t want to require users to share the lock instance across processes you will have to give them names. Eg:

conn = StrictRedis()
with redis_lock.Lock(conn, "name-of-the-lock"):
    print("Got the lock. Doing some work ...")
    time.sleep(5)

Eg:

lock = redis_lock.Lock(conn, "name-of-the-lock")
if lock.acquire(blocking=False):
    print("Got the lock.")
else:
    print("Someone else has the lock.")

Features

• based on the standard SETNX recipe

• optional expiry

• no spinloops at acquire

Implementation

redis_lock will use 2 keys for each lock named <name>:

• lock:<name> - a string value for the actual lock

• lock-signal:<name> - a list value for signaling the waiters when the lock is released

This is how it works:

TODO

• ???

Requirements

Redis 2.6 or later.

Python 2.6, 2.7, 3.2, 3.3 and PyPy are supported.

Similar projects

• bbangert/retools - acquire does spinloop

• distributing-locking-python-and-redis - acquire does polling

• cezarsa/redis_lock - acquire does not block

• andymccurdy/redis-py - acquire does spinloop

• mpessas/python-redis-lock - blocks fine but no expiration