How to create a distributed lock with Redis?

Question

On the redis documentation, I found a primitive lock can be implemented via SETNX:

http://redis.io/commands/setnx

• C4 sends SETNX lo

Answer 1

I gem'ed out the SET EX NX solution that misterion mentioned to a cool gem - simple_redis_lock

The code is simple and looks like this:

def lock(key, timeout)
  if @redis.set(key, Time.now, nx: true, px: timeout)
    begin
      yield
    ensure
      release key
    end
  end
end