countOnce

just once? no, when appear many it run once, but it can run many times

灵感来源

参考sync.once 只能发生一次,此包提供了并发时发生一次,多次调用仍有效

code start

queueMutex = utils.NewQueueMutex()
queueMutex.Do(func() {
  do something...
}