《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)
**粗体** _斜体_ [链接](http://example.com) `代码` - 列表 > 引用
。你还可以使用@
来通知其他用户。