https://www.cnblogs.com/ecin/p/6201262.html#%E5%9F%BA%E4%BA%8E%E9%98%9F%E5%88%97%E7%9A%84%E4%BB%BB%E5%8A%A1%E5%A4%84%E7%90%86fire-and-forget-jobs
