OS -- three easy pieces -- Introduction

最新推荐文章于 2024-05-16 16:14:47 发布

MoMo_qyc

最新推荐文章于 2024-05-16 16:14:47 发布

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分类专栏： course notes 文章标签： Operating System

本文链接：https://blog.youkuaiyun.com/MoMo_flamboyant/article/details/86495775

本文介绍了操作系统的基本概念，包括虚拟化如何将单一CPU转化为多个虚拟CPU，实现多程序同时运行；并发处理带来的挑战，如内存访问同步问题；以及持久化存储的重要性，操作系统如何通过文件系统管理数据，确保数据在系统故障后的恢复。

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Virtualization:

Assume there is one physical CPU in a system (though now there are often two or four or more). What virtualization does is take that single (physical) CPU and make it look like many virtual CPUs to the applications running on the system.

Concurrency:
In multi-threaded applications, where each thread is independently doing things on the program's behalf, suppose that these threads access memory. If we don't coordinate access to memory between threads, the program won't work as expected.
First, the OS must support multi-threaded applications with primitives such as locks and condition variables.
Second, the OS itself was the ﬁrst concurrent program — it must access its own memory very carefully.

Persistence:

making information persist, despite computer crashes, disk failures, or power outages.

Introduction to Operating Systems

the basics of the Von Neumann model of computing:
a running program: instructions (fetch -> decode -> execute)

1 The role of OS

the primary goal of making the system easy to use -- the operating system (OS)

what an OS actually does:
It takes physical resources, such as a CPU, memory, or disk, and virtualizes them.
It handles tough and tricky issues related to concurrency.
It stores ﬁles persistently, thus making them safe over the long-term.