缓存锁的一个思路(代码未验证)
@contextmanager
def custom_lock(key, timeout):
"""如果有任务执行, 返回任务执行的时间, 单位返回s, 如果没有任务执行, 返回None"""
value = cache.get(key)
now = int(time.time() * 1000)
if value:
yield (now - int(value))
else:
if cache.add(key, now, timeout):
yield
else:
yield int(cache.get(key))
cache.delete(key)
with custom_lock(key) as t:
if t is not None:
print '已经执行了{0}ms'.format(t)
else:
do_something()
