《Operating System Concepts》阅读笔记：p26-p33

《Operating System Concepts》学习第 6 天，p26-p33 总结，总计 8 页。

一、技术总结

1. timer

(1)为什么设置 timer

We must ensure that the operating system maintains control over the CPU. We cannot allow a user program to get stuck in an infinite loop or to fail to call system services and never return control to the operating system. To accomplish this goal, we can use a timer.

(2)定义

A hardware component that can be set to interrupt the computer after a specifi ed period.

二、英语总结(生词：4)

1.reclaim

(1)reclaim: re-(“again”) + clamare(“cry out, shout, call”)

vt. recalim litterally means “to claim back”, “to take back”, or “to demand the return of sth”。It is often used to describe restoring something to a better state or asserting ownership over something that was lost or taken away.

示例：When the process terminates, the operating