There are two common ways to implement timers:

  • The minimum heap
  • Time round

Minimum heap of insert time complexity is O (logn), such as ScheduledThreadPoolExecutor DelayedWorkQueue, and the realization of the wheel of time, insert needs only O (1), in the deleted due time complexity is O (1)

Time wheel is divided into a single layer and multi-layer, multi-layer mainly to solve the problem of time overflow, can also use the realization of a single wheel multi-ring, here with golang wrote a single wheel multi-ring implementation, test code…

A time wheel with a minimum time scale of 100ms and 1024 slots is generated, tw.AddScheduleTask means to add a scheduled task, and the test result is:

Nothing else… Specific look at the source code and test code…

Source address: Github