《Operating System Concepts》学习第 46 天,p512-p527 总结,总计 16 页。

一、技术总结

1.front-end processor

(1)定义

Small computers that perform certain tasks in an overall system; used by some systems to manage I/O and offload the general-purpose CPU.

(2)示例

terminal concentrator。

二、英语总结(生词:3)

1.malfunction

(1)malfunction: mal-("bad") + function

c/u. a situation in which a system stops working normally(故障)。

(2)示例

An operating system that uses protected memory can guard against many kinds of hardware and application errors, so that a complete system failure is not the usual result of each minor mechanical malfunction(《Operating System Concepts》第 511 页)。

2.transient

(1)transitent: trans-("across, beyond") + ire("to go")

adj. lasting for only a short time; temporary(短暂的,暂时性的)。Transient means literally "go across", which implies "pass through sth rather than staying"。

(2)示例

Devices and I/O transfers can fail in many ways, either for transient reasons, as when a network becomes overloaded, or for “permanent” reasons, as when a disk controller becomes defective(《Operating System Concepts》第 512 页)。

3.compensate

(1)compensate: com-("together, with") + pensare("weight, pay")

vt. give (sb) sth, like money, in recognition of loss, suffering or injure(补偿)。vi. to offset an error, defect, or undesired effect(弥补(错误,缺陷,不希望的结果))。

(2)示例

示例1:His enthusiasm compensates for his lack of skil(他的热情弥补了他技术上的不足)。

在这个例子中,使用 “enthusiasm” 来弥补 “lack of skill”。

示例2:Operating systems can often compensate effectively for transient failures. For instance, a disk read() failure results in a read() retry, and a network send() error results in a resend(), if the protocol so specifies(《Operating System Concepts》第 512 页)。

在这个例子中,如果只看第一句“通常,操作系统能有效弥补(应对)暂时性故障”,其实不大好理解,因为没有直接体现“使用什么来弥补什么”?翻译为“弥补”也不大通畅。需要结合后面一句来理解。operating system 是怎么弥补 transient failures 的呢?使用 “ read() retry” 来弥补 “read() failure”, 使用 “resend()” 来弥补 “send() error”。

从技术上来说不难理解,其实就是“重试机制”,但是如果不理解词的意思,有时候就不能很好的理解作者想表达的意思。

关于英语的注解同步更新汇总到 https://github.com/codists/English-In-CS-Books 仓库。

三、其它

第 12 章(I/O Systems)简评:介绍 bus, controller, power management, STREAMS 等,也很抽象。

四、参考资料

1. 编程

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

2. 英语

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

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

欢迎搜索及关注:编程人(a_codists)


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