Python实现Redis分布式锁的示例代码与解析

#!/usr/bin/env python
# coding=utf-8
import time
import redis
class RedisLock(object):
  def __init__(self, key):
    self.rdcon = redis.Redis(host='', port=6379, password="", db=1)
    self._lock = 0
    self.lock_key = "%s_dynamic_test" % key
  @staticmethod
  def get_lock(cls, timeout=10):
    while cls._lock != 1:
      timestamp = time.time() + timeout + 1
      cls._lock = cls.rdcon.setnx(cls.lock_key, timestamp)
      if cls._lock == 1 or (time.time() > cls.rdcon.get(cls.lock_key) and time.time() > cls.rdcon.getset(cls.lock_key, timestamp)):
        print "get lock"
        break
      else:
        time.sleep(0.3)
  @staticmethod
  def release(cls):
    if time.time() < cls.rdcon.get(cls.lock_key):
      print "release lock"
      cls.rdcon.delete(cls.lock_key)
def deco(cls):
  def _deco(func):
    def __deco(*args, **kwargs):
      print "before %s called [%s]."%(func.__name__, cls)
      cls.get_lock(cls)
      try:
        return func(*args, **kwargs)
      finally:
        cls.release(cls)
    return __deco
  return _deco
@deco(RedisLock("112233"))
def myfunc():
  print "myfunc() called."
  time.sleep(20)
if __name__ == "__main__":
  myfunc()