《Introduction引论.ppt》由会员分享，可在线阅读，更多相关《Introduction引论.ppt（22页珍藏版）》请在三一办公上搜索。
1、1:Introduction 引论,What is an operating system?什么是操作系统？Simple Batch Systems简单批处理系统Multiprogramming Batched Systems多道程序批处理系统Time-Sharing Systems分时系统Personal-Computer Systems 个人计算机系统Parallel Systems并行系统Distributed Systems分布式系统Real-Time Systems实时系统,What is an Operating System?什么是操作系统？,A program that act
2、s as an intermediary between a user of a computer and the computer hardware.在计算机用户和计算机硬件之间起媒介作用的一种程序。Operating system goals:操作系统目标Execute user programs and make solving user problems easier.执行用户程序并使用户问题更易解决。Make the computer system convenient to use.使计算机系统更易使用。Use the computer hardware in an efficie
3、nt manner.以一种效率的方式使用硬件。,Computer System Components计算机系统部件,1.Hardware硬件 provides basic computing resources(CPU,memory,I/O devices).提供基本的运算资源2.Operating system操作系统 controls and coordinates the use of the hardware among the various application programs for the various users.在各种应用程序和用户之间控制与协调对硬件的使用3.App
4、lications programs 应用程序 define the ways in which the system resources are used to solve the computing problems of the users(compilers,database systems,video games,business programs).定义解决用户问题的资源使用方式（编译、数据库、视频游戏、事务程序等）4.Users(people,machines,other computers)用户（人、机、其他计算机）.,Abstract View of System Compo
5、nents系统部件的抽象观点,Operating System Definitions操作系统定义,Resource allocator资源分配者 manages and allocates resources.管理和分配资源Control program控制程序 controls the execution of user programs and operations of I/O devices.控制用户程序的运行和I/O设备的操作Kernel 内核 the one program running at all times(all else being application progr
6、ams).在全时运行的一个程序（其他的是应用）,Simple Batch Systems简单批处理系统,Hire an operator雇一个操作员User operator用户操作员Add a card reader添加卡片阅读机Reduce setup time by batching similar jobs批量处理同类作业减少了设置时间Automatic job sequencing 自动作业调度 automatically transfers control from one job to another.First rudimentary operating system.自动把控
7、制从一个作业转到另一个作业。第一个基本操作系统。Resident monitor常驻管理程序initial control in monitor 初始化管理程序control transfers to job 转换控制到作业when job completes control transfers back to monitor作业完成后转换控制回管理程序,Memory Layout for a Simple Batch System简单批处理系统的存储器布局,Control Cards作业控制卡,Problems问题1.How does the monitor know about the n
8、ature of the job(e.g.,Fortran versus Assembly)or which program to execute?管理程序如何知道作业的性质（如，Fortran还是汇编）或哪个程序要运行？2.How does the monitor distinguish管理程序如何区别(a)job from job?一个个的作业？(b)data from program?数据还是程序？Solution解法Introduce control cards引入作业控制卡,Control Cards作业控制卡(Cont.),Special cards that tell the r
9、esident monitor which programs to run特殊卡片通知管理程序哪个程序运行$JOB$FTN$RUN$DATA$ENDSpecial characters distinguish control cards from data or program cards特定的字符把数据卡片和程序卡片区分开来:$in column 1/in column 1 and 2709 in column1,Control Cards作业控制卡(Cont.),Parts of resident monitor常驻管理程序的一部分Control card interpreter resp
10、onsible for reading and carrying out instructions on the cards.控制卡片解释器-负责读出和执行卡上的指令Loader loads systems programs and applications programs into memory.装载程序-把系统程序和应用程序调入内存Device drivers know special characteristics and properties for each of the systems I/O devices.设备驱动程序-了解系统每一个I/O设备的特点和性质Problem:Sl
11、ow Performance I/O and CPU could not overlap;card reader very slow.问题：慢-I/O和CPU不可能彼此覆盖；卡片阅读器很慢Solution:Off-line operation speed up computation by loading jobs into memory from tapes and card reading and line printing done off-line.解决：脱机操作-从磁带和卡片调作业进入内存，而打印机脱机，加速运算,Spooling,Overlap I/O of one job wit
12、h computation of another job.While executing one job,the OS.一个作业的I/O 同另一个作业的运算彼此重叠。在执行一个作业时，OS。Reads next job from card reader into a storage area on the disk(job queue).从卡片上把下一个作业读入磁盘存储区（作业队列）Outputs printout of previous job from disk to printer.从磁盘到打印机输出先前的作业Job pool 作业池 data structure that allows
13、 the OS to select which job to run next in order to increase CPU utilization.一种允许操作系统选择运行作业的数据结构，用以提高CPU利用率,Multiprogrammed Batch Systems多道程序批处理系统,Several jobs are kept in main memory at the same time,and the CPU is multiplexed among them.在主存中同时有若干个作业，CPU在其中多重切换。,OS Features Needed for Multiprogramm
14、ing多道程序对OS特点的要求,I/O routine supplied by the system.系统提供I/O程序Memory management存储管理 the system must allocate the memory to several jobs.系统必须为若干作业分派空间 CPU scheduling CPU调度 the system must choose among several jobs ready to run.系统必须在就绪作业中挑选Allocation of devices.设备分配,Time-Sharing SystemsInteractive Compu
15、ting分时系统-交互式计算,The CPU is multiplexed among several jobs that are kept in memory and on disk(the CPU is allocated to a job only if the job is in memory).对保存在内存和磁盘上的若干作业之间多路（CPU被分配给某个作业仅当该作业在内存）A job is swapped in and out of memory to the disk.作业在内存和磁盘之间被对换On-line communication between the user and t
16、he system is provided;when the operating system finishes the execution of one command,it seeks the next“control statement”not from a card reader,but rather from the users keyboard.提供用户和系统之间的在线通信；操作系统完成了一条命令的执行后，它不从卡片阅读机上而是从用户键盘上寻找下一条控制语句On-line system must be available for users to access data and c
17、ode.在线系统必须使用户能够访问数据和代码,Personal-Computer Systems个人计算机系统,Personal computers computer system dedicated to a single user.个人计算机-供个人使用的计算机系统I/O devices keyboards,mice,display screens,small printers.I/O设备-键盘、鼠标、显示、小型打印机User convenience and responsiveness.便利用户和响应Can adopt technology developed for larger op
18、erating system often individuals have sole use of computer and do not need advanced CPU utilization of protection features.可采用大型操作系统研发的技术，个人独占计算机不需要高级CPU使用的保护技术,Migration of Operating-System Concepts and Features操作系统概念和特性的变迁,Parallel Systems并行系统,Multiprocessor systems with more than one CPU in close
19、 communication.有紧密通信的、多于一个CPU的多处理器系统Tightly coupled system processors share memory and a clock;communication usually takes place through the shared memory.紧偶合系统-处理器共享内存和时钟；一般通过共享内存进行通信Advantages of parallel system:并行系统的优点Increased throughput增大吞吐量Economical 经济Increased reliability提高可靠性graceful degrad
20、ation（有故障时）优雅的降低性能fail-soft systems（又称）软失效系统,Parallel Systems并行系统(Cont.),Symmetric multiprocessing(SMP)对称多处理 器Each processor runs an identical copy of the operating system.每个处理器运行操作系统的相同副本Many processes can run at once without performance deterioration.许多进程可以立即运行不会降低性能Most modern operating systems s
21、upport SMP多数现代操作系统支持SMPAsymmetric multiprocessing非对称多处理器Each processor is assigned a specific task;master processor schedules and allocates work to slave processors.每个处理器赋予一个特定任务；主处理器为从处理器调度和分配作业More common in extremely large systems常用在非常大的系统中,Symmetric Multiprocessing Architecture对称多处理器体系结构,Real-Ti
22、me Systems实时系统,Often used as a control device in a dedicated application such as controlling scientific experiments,medical imaging systems,industrial control systems,and some display systems.通常作为控制设备在诸如控制科学实验、医学影象系统、工业控制系统以及一些显示系统中应用Well-defined fixed-time constraints.严格确定的时间限制Hard real-time system
23、.硬实时系统Secondary storage limited or absent,data stored in short-term memory,or read-only memory(ROM)有限的或没有次级存储器，数据存在短期存储器或只读存储器中Conflicts with time-sharing systems,not supported by general-purpose operating systems.同分时系统冲突，通用操作系统Soft real-time system软实时系统Limited utility in industrial control or robot
24、ics在工业控制或机器人中有部分应用Useful in applications(multimedia,virtual reality)requiring advanced operating-system features.在需要高级操作系统 功能的应用（多媒体、虚拟现实）中应用,Distributed Systems分布式系统,Distribute the computation among several physical processors.计算分布在若干物理处理器上Loosely coupled system each processor has its own local mem
25、ory;processors communicate with one another through various communications lines,such as high-speed buses or telephone lines.松散偶合系统-每个处理器有自身的本地存储器；通过各种通信设施，如高速总线、电话线等进行处理器之间的通信Advantages of distributed systems.分布式系统的优点Resources Sharing 资源共享Computation speed up load sharing 加快计算-共享装载Reliability可靠Comm
26、unications通信,Distributed Systems分布式系统(Cont.),Network Operating System网络操作系统provides file sharing 提供文件共享provides communication scheme提供通信机制runs independently from other computers on the network运行独立于网络上的其他计算机Distributed Operating System分布式操作系统less autonomy between computers在计算机之间少了自治性gives the impression there is a single operating system controlling the network.给出一种印象，有一个操作系统控制网络,
