1、计算机操作系统复习现代操作系统1 Introduction 引论Application programs 应用程序Application environment 应用环境System programs 系统软件Virtual environment 虚环境Operating System 操作系统ABVirtual machine 虚机器Microcode 微码Bare machine 裸机Hardware 硬件A：公开天窗，B：未公开的天窗Figure1-1 Computer architecture N-Levels(Theory) 计算机系统的N层结构图Applications各种应用1
2、 Web Browser/E-mail system/. with call The functions of OS only 仅仅使用操作系统功用调用的浏览器，电子邮件等2 Airline3 Banking system4 Games/CAD/EAD/Software软件 Operating System操作系统The functionsWeb Browser E-mailreaderMusicplayerOtherOSs appsUser mode 用户态Kernel mode 核心态 Hardware硬件 Where the operating system fits in.操作系统所处
3、位置Hardware - Bare machine 3 Machine language 机器语言2 Microarchitecture 微体系结构1 Physical devices 物理器件 firmware 固件Operationg System - Virtual machine 1 Processor management 处理机管理 2 Job management 作业管理 3 Memory management 存储器管理 4 Device management 设备管理 5 File system 文件系统System programs - Virtual environme
4、nt 1 Shells (Command interpreter) 2 Editors 3 CompilersApplication programs - Application environment 1 Web Browser 2 Airline 3 Banking system 4 Games/CAD/EAD/1.1 What is an Operating System? 1:as an Extended/Virtual Machine (p4) e.g., PD765 floppy disks operations. 象一个扩展或虚拟机 2:as a Resource Manager
5、 (p6) include in time and in space 象一个资源管理者The Purposes is (My Standpoint ) (1)将不同的裸机改造成一台功能更强、服务质量更高、用户使用起来更加灵活方便、更加安全可靠的、感觉上完全一样的虚机器。 裸机各种机型完全不同使用极为不便，也极不安全，操作系统解决这些问题。就拿IBMPC机各厂家都不同，这里有技术问题（各厂家自己的技术优势）也有法律问题（知识产权、专利等等） 不同：各厂家的硬件不同，使用者要学所有的硬件。 不便：写内存，很困难，直接解除硬件可损坏硬件。 安全：各个用户的信息在计算机中有一定保密要求。DOS就没有安
6、全性，所有数据对用户都是可知、可得的。 (2)更加充分、合理地使用系统内的各种软件硬件资源，在整体上大大提高计算机系统的使用效率和经济效益。 计算机系统中硬件总是比较昂贵的，用户希望尽可能高效的使用计算机，有高的性能价格比，产生好的经济效益，使投资早日收会。Questions: 1,Why the Figure is in theory and not in real ? Answer are “The Skylights” (the open/secrecy skylights ) 2,计算机系统的N层结构有以下几个特点： 1单向服务的理论层次结构 2全包含低层的理论层次结构 3留有天窗的实
7、际层次结构 3,Compile and interpret 编译，把高层次已成文的完整程序翻译成一个更低层次的完整程序。 解释，把高层次的不完整的程序（一般是一两条语句）翻译成更低一层次的完整程序。 4,编译中的四步： 1编写源程序。思想 到源程序 编辑器 Editor 2编译源程序。源程序到目标(机器)码 编译器 complier 3链接目标码。目标码到OS格式的可执行码 链接器 Linker 4执行可执行码。在OS下运行执行码。1.2 The History 1The First Generation (1945-55) Vacuum Tubes and Plugboards P7电子管与
8、插接板 2The Second Generation (5665) Transistors and Batch System P8晶体管与批处理系统 3The Third Generation (6580) Multiprogramming P10多道程序设计 4The Fourth Generation (80Present) Personal Computers P15个人计算机系统1.4 The Operating System Zoo P33 操作系统大观园 1.4.1 Mainframe Operating System. OS/390 OS/360 bath, timesharin
9、g, transaction processing. 批处理/分时系统/事物处理 1.4.2 Server Operating Systems. UNIX/Windows 2000 Print/file/Web Service. 1.4.3 Multiprocessor Operating Systems Parallel computer, multi-computers (multiprocessors) 并行计算机/多机（多处理器） 1.4.4 Personal computer Operating System Windows/ the Macintosh OS / Linux In
10、fact, many people are not even aware that other kinds exist. 1.4.5 Handheld Computer Operating Systems 掌上计算机操作系统 PDA (Personal Digital Assistant) 个人数字助理 1.4.6 Embedded Operating Systems.嵌入式操作系统 1.4.7 Sensor Node Operating Systems传感节点操作系统 1.4.8 Real-time Operating Systems the time is the main key par
11、ameter. 时间是关键因素的操作系统 Hard/Soft real-time 硬/软实时 1.4.9 Smart Card Operating Systems 智能卡操作系统Conceptbatch system Fig1-3FMS (the Fortran Monitor System) Fig1-4Multiprogramming Fig1-51.3 Computer Hardware review P17 Figure 1-6 Some of the components of a personal computer. 1 bus 2 Monitor / Keyboard / Flo
12、ppy/ hard disk (can be seen) 3 CPU/ Memory /controller :Video / Keyboard / Floppy /Hard disk 4 Communication ports :1 serial 2 parallel 1.3.1 Processors pc: program counter sp: stack pointer psw: Program status word 程序状态字 What CPU can do ? Simple model : It (1)fetches instructions from memory and (2
13、)executes them. Fig1-7 And (2) decodes (3)executes them.Modern model :the fetching, decoding, and executing instruction at a time have been done (this is the pipeline ). 现代模式：取指、译码、执行在用一时刻完成(这就是流水线)。ConceptMultithreaded and Multicore Chips: 多线程和多核芯片 Fig1-81.3.2 Memory Figure 1-9 A typical memory hie
14、rarchy. P21 典型的存储器层次 The basic problems: (The Second edition) 1 How to protect the programs from one another and the kernel from them all. 2 How to handle relocation. (彼此之间) The simplest solution is using the Base and limit register p26 and p27 Figure 1-9 1.3.3 DisksFigure 1-10. Structure of a disk
15、drive.1.3.4 Tapes1.3.5 I/O Devices P27 Three ways to put the driver into the kernal: P29 1: To relink the kernel with new driver and reboot the system. (many UNIX do this ) (重新链接核心) 2: To Make an entry in an operating system file. At the boot time operating system goes and finds drivers and loads th
16、em . (Windows work this way) (使用程序入口) 3: Hot pluggable devices. (such as USB-Universal serial bus) (热插拔) ( plug and play 即插即用)I/Os address: P29 1:No special I/O instructions 2: have special I/O instructions and address.Input and output can be done in three ways: P29 1: the program issues a system ca
17、ll (the simplest method) 2: using interrupt. Fig1-11 3: DMA (Direct Memory Access) 直接存储器访问1.3.6 Buses Figure 1-12 P31 Bus: 1:cathe 2: local 3: Memory 4:PCI 5:ISA 6 SCSI 7IDE and 8USB Bridge :1 PCI bridge 2 ISA bridge1.3.7 Booting the Computer Concept: BIOS (Basic Input Output System). The BIOS conta
18、ins low-level I/O software, including procedures to read the keyboard, write to the screen, and do disk I/O, among other things. Nowadays, it is held in a flash RAM, which is nonvolatile but which can be updated by the operating system when bugs are found in the BIOS.1.5 Operating System Concepts P3
19、51.5.1 Processes (进程) 1:task and process 2: Process tree.(Figure 1-13 .P37) Associated with processes : 1 Address Space(Program , Data and Stack) 2 Registers (PC: Program Counter, SP: Stack Pointer, Port Registers eg.) 与进程有关的1是地址空间( 包含程序，数据和堆栈) 2 寄存器 （包括PC程序计数器，SP堆栈指针，端口寄存器等） Process Table : 进程表 Chi
20、ld Process:子进程 Parent Process:父进程 Process Tree :进程树 IPC: interprocess communication 进程间通讯 UID: User Identification Person authorized to use a system by the system administrator GID: Group Identification All child processes have same UID as its parent. They can be remembers of group. Superuser : It i
21、s One UID. UNIX中的有关命令： 1ps 2kill1.5.2 Address Spaces 地址空间 p38 32 or 64 bits1.5.3 Files P38 root directory (根目录) path name (路径名) working directory (工作目录) file descriptor (file handle) (文件描述符) Some files: 1 block special file and character special file (块与字符文件) 2 stream file and raw file (流与原始文件) 3 no
22、rmal file and special file (普通与特殊文件) UNIX中与文件有关的问题： pipe 管道 连接文件或进程的通信标准。 管道都是单向的。 Figure 1-16. Two processes connected by a pipe. P42 mount 操作，把某文件系统安装到某个目录下。 Figure 1-15. mount a CD p41block and character file 块和字符文件。列表以b和c开头的文件 directory file 目录文件。 以d开头的文件 3个缺省文件： 标准输入 stdin 标准输出 stdout 标准错误 stde
23、rr 用bc演示 标准文件与管道。 物理文件与逻辑文件 UNIX中的目录结构 1 / root 根 2 /下目录 bin usr lib tmp dev etc 3 /usr下目录 HOME include 命令：1pwd 几个目录名:“.”当前目录 “.” 上一级目录 “/”根目录 2cd 3mkdir 4rmdir5cp file1 file2 拷贝文件 6mv file1 file2 文件改名 7ln file1 file2 建立逻辑文件 8rm files 删除文件 9cat files 10more files 11 l 命令族 l/lc/ls 用cat产生文件:$cat OneFi
24、lethis is first linethis is second line产生一个新文件OneFile.1.5.4 Input/Output 输入输出1.5.5 Protection 保护1.5.6 The Shell GUI : window x-windows Text mode: cmd sh, csh, ksh, andbash. Unix下的shell 练习:date,sort 和定向 p431.5.7 Ontogeny Recapitulates Phylogeny 个体发育重复着种族的发展 P44 Charles Darwin The Origin of Species On
25、togeny The origin and development of an individual organism from embryo to adult.个体发育一个生物个体从胚胎到成年的由来和发展Phylogeny The historical development of a tribe or racial group. 种族系统史部落或种族的历史发展 The mean is the development of an embryo (ontogeny) repeats (recapitulates) the evolution of the species. 一个胚胎embryo
26、（个体）重复物种species的演化.In other words, after fertilization, a human egg goes through stages of being a fish, a pig, and so on before turning into a human baby. 人类的受精卵在变成人体前，经历了鱼和猪等阶段。(一般认为，世界上的所有生物都是同一种起源，人是做高级阶段) In the computers (mainframe, minicomputer, personal computer (microcomputer), embedded com
27、puter, smart card) seems to go through the development that its ancestors did. 在计算机“种族”(主机,微计算机，个人计算机(微机),嵌入式计算机，智能卡)里，所有个体都重复祖先的阶段。 1,The computers used the assembler firstly, then go to the high-level language. (No for lack of memory) 所有计算机都从汇编开始，到高级语言(不是缺少住存) 2,All OS beginning the no protection
28、hardware and no support for multiprogramming 所有操作系统都是从无保护的硬件和不支持多道程序开始 3,Disks first appeared on the large mainframes, and are used by the all computers. 4,Virtual memory problems.Large Memories p45Protection Hardware p45Disks p46Virtual Memory p47Deadlocks (死锁) When two or more processes are intera
29、cting, they can sometimes get themselves into a stalemate situation they cannot get out of. 当两个以上的进程相互作用时，它们可能进入一种它们自己不可能出来的僵局。 Figure 1-13 A potential and actual deadlock (潜在和真实的死锁)1.6 SYSTEM CALLSFigure 1-17 The 11 steps in making the system call read(fd,buff,nbytes) P491.6.1 System Calls for Proc
30、ess ManagementProcess managementCallDescriptionpid = fork( )Create a child process identical to the parentpid = waitpid(pid, &statloc, options) Wait for a child to terminates = execve(name, argv, environp) Replace a process core imageexit(status) Terminate process execution and return statusFile managementCall Descriptionfd = open(file, how, .) Open a file for reading, writing, or boths = close(fd) Close an open filen = rea
