[OS]Preview

Index

1. Computer system Overview

2. OS Overview

3. System call

4. Process description and control

5. Thread

6. Cpu scheduling

7. Concurrency-Mutual exclusion and synchronization

8. Memory management

9. virtual memory

10. I/O management and disk scheduling

 

 

Operating System(OS)란?

 

1.시스템 SW, 프로그램, 자원관리자 - memory, disk space, CPU time, I/O, software 등을 관리

(효율성 극대화)

2. 어플리케이션 개발 환경 제공- 사용자가 프로그램, 어플리케이션, 시스템 소프트웨어 이용을 편리하게 함.(편리성)

 

Why studying OS?

1. OS는 어디에나 있다. 사용 목적에 따라 확장가능

2. 적절한 추상화를 통해 복잡성을 다루는 법은 배운다.

3. 시스템 프로그래머로써 어떻게 시스템이 작동하는지 이해한다.

-best way to learn concurrent programming

- involves designing programs that allow the computer HW to interface with the programmer and the user.

-depends on system performance

 

Why use an OS?

: 공통적인 UI를 제공하므로써 어플리케이션이 일일이 HW에 접근해 디테일적인 업무(이를 테면 low coding)를 수행할 일  없이, 지속적이고 반복적인 서비스를 사용자 및 개발자에게 제공한다.

 

It brings powerful benefits to computer SW and its development. 

With OS, Every application would not need to includes its own UI, as well as the comprehensive code

not needed to handle all low-level functionality of the underlying computer, such as disk storage, network interfaces and so on. Of course it doesnt needed to bloat the size of every application or make software development impractical, as long as each application accesses the same resources and services in the same way, OS can service almost any number of applications. So that many common tasks, such as sending a network packet or displaying text on a standard output device, such as a display, can be offloaded to system software that serves as an intermediary between the applications and the hardware. The system software provides a consistent and repeatable way for applications to interact with the hardware without the applications needing to know any details about the hardware.

 

사용

The application programs make use of the OS by making request for services through API(application program interface).

cf). In addition, users can interact with the operating system, directly through a user interface such as a command-line interface (CLI) or a graphical UI (GUI).