By dispatching from a queue's head and placing expired threads at a queue's tail, execution happens in a round-robin fashion within a priority.
通过从队列的前端分派线程和在队列的后端放置过期的线程，程序在一个优先级中轮替执行。
2
The time between the arrival of the interrupt and dispatching of the required task (assuming it's the highest-priority task to dispatch) is called the response time.