Redis分布式锁的python实现

案例1：

#!/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)
　　　　　　　# 注意下方括号的范围
            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(""))
def myfunc():
    print "myfunc() called."
    time.sleep(20)

if __name__ == "__main__":
    myfunc()

案例2：

import redis
import time, datetime

def acquire_lock(conn, lockname, identifier, expire=10):
    if conn.setnx(lockname, identifier):
        conn.expire(lockname, expire)
        return identifier
    elif not conn.ttl(lockname):
        conn.expire(lockname, expire)

    return False

def release_lock(conn, lockname, identifier):
    pipe = conn.pipeline(True)
    while True:
        try:
            pipe.watch(lockname)
            if pipe.get(lockname) == identifier:
                pipe.multi()
                pipe.delete(lockname)
                pipe.execute()
                return True
            pipe.unwatch()
            break
        except redis.exceptions.WatchError:
            pass

    # we lost the lock
    return False

conn = redis.Redis(host='localhost', port=6379, db=0)

# 1 identifier
# 2 False
# 11 True
# 22 False
# 33 barx2
# 44 True

ret = acquire_lock(conn, "lockname", "identifier", 3)
print "", ret
ret = acquire_lock(conn, "lockname", "identifier", 3)
print "", ret
ret = release_lock(conn, "lockname", "identifier")
print "", ret
ret = release_lock(conn, "lockname", "identifier")
print "", ret

ret = acquire_lock(conn, "footest", "bartest", 10)
print "", ret

参考文档：

https://blog.csdn.net/weixin_39471249/article/details/79121291

http://xiaorui.cc/2014/12/19/python%E4%BD%BF%E7%94%A8redis%E5%AE%9E%E7%8E%B0%E5%8D%8F%E5%90%8C%E6%8E%A7%E5%88%B6%E7%9A%84%E5%88%86%E5%B8%83%E5%BC%8F%E9%94%81/

https://www.cnblogs.com/SimplifyIT/p/6691584.html