《Operating System Concepts》學習第 6 天，p26-p33 總結，總計 8 頁。

一、技術總結

1. timer

(1)為什么設置 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)定義

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

二、英語總結(生詞：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 system will reclaim any reusable resources(《Operating System Concepts》第 18 頁)。

2.rigidly

(1)rigid: rigere("be stiff(firm or hard)")

adj. stiff or fixed; not able to bent or moved.

(2)rigidly

adv. in a stiff or fixed way.

示例：Files may be free-form (for example, text files), or they may be formatted rigidly (for example, fixed fields such as an mp3 music file)(《Operating System Concepts》第 29 頁)。

在上面這句話中，rigidly 的意思是“strictly, inflexibly, in a highly structured manner”,當然，這種描述比較抽象。

3.hinge

(1) hinge: hangen("to hang")

c. a piece of metal that fastens the edge of a door(固定門的鉸鏈(注：搜實物圖來看))。vi. (+on/upon)depends on。

示例：The entire speed of operation of a computer may hinge on the speeds of the secondary storage subsystem and the algorithms that manipulate that subsystem(《Operating System Concepts》第 30 頁)。

4.peculiarity

(1)peculiar: peculium("private property, personal possession")

adj. Peculiar literally means "sth that is specially one's own", like personal propery, over time, peculiar envolves to mean "sth that is distinct, unusual or different"。

(2)peculiarity: peculiar + -ity

c/u. the distinctive, unusual, or unique feature or characteristic of sth(特性).

示例：Only the device driver knows the peculiarities of the specific device to which it is assigned(《Operating System Concepts》第 32 頁)。

關于英語的注解同步更新匯總到 https://github.com/codists/English-In-CS-Books 倉庫。

三、其它

感覺自己很弱，缺的知識很多，閱讀進度很慢。

四、參考資料

1. 編程

(1) Abraham Silberschatz，Peter Baer Galvin，Greg Gagne《Operating System Concepts》：https://book.douban.com/subject/30272539/

2. 英語

(1) Etymology Dictionary：https://www.etymonline.com

(2) Cambridge Dictionary：https://dictionary.cambridge.org

歡迎搜索及關注：編程人(a_codists)