... USAxiv Operating Systems research is a vital and dynamic eld. Even young computer science students know that OperatingSystems are the core of any computer system and a course about OperatingSystems ... “rings” and numbered as 0,1,2,3 whereas 0 is the most privileged ring and 3 is the least privileged. Linux uses just ring 0 and 3. Ring 0 is used when the kernel is executed, whereas 3 is used ... students to research this eld and to contribute their aptitude. A probe of recent operatingsystems conferences and journals focusing on the “pure” Operating Systems subjects (i.e. Kernel’s...
... MSSV:08520470Sau đây là bài dịch chương II trong sách “Principles of Digital Communication Systemsand Computer Networks” của nhóm em.Phần I – Các hệ thống truyền thông số(Digital Communation ... entropy là H = 4.07 bit/ký hiệuLưu ý: Hãy xem xét câu sau: "I do not knw wheter this is undrstandble." Mặc dù thực tế là một số chữ cái là mất tích trong câu này nhưng bạn vẫn có thể làm...
... program.16Dynamical Systemsand Figure 1.2-12Mach 10. Computer graphics in, computer art out. In the next chapter we will explain the relationbetween experimental mathematics andcomputer graphics. ... graphical methods are used to achieve this. charts and pie-charts, as well as coordinate systems with curves, are widespreadexamples. In most cases not only is a picture ‘worth a thousand words’: the ... mathematics and computer graphics, we will show you some of these computer graphics.Soon you will beproducing these, or similar, graphics for yourself. Whether they can be described ascomputer...
... abilities and our patience,our WOZ experiments pointed the way to a more user-friendly computer sciencemodel: the multi-processing operating system.In UNIX-flavored systems, the user may have ... foreground and background narratives, in same wayas the fg and bg console commands can swap UNIX foreground and backgroundprocesses,3a background narrative can always create an “interrupt,” demandingattention ... story of military arrogance; and, (e) a deterioratingsituation at base command, where demands on men and equipment may meana shortage of relief troops, ground vehicles, and helicopters. On their...
... file, and seconds is the elapsed time. Theparameters are explained in the text.User program and dataUser program and data Operating SystemAddress0xFFFFFFFFLimitBase0(a)User-2 dataUser-1 ... CPU.1INTRODUCTION1.1 WHAT IS AN OPERATING SYSTEM?1.2 HISTORY OF OPERATING SYSTEMS 1.3 THE OPERATING SYSTEM ZOO1.4 COMPUTERHARDWARE REVIEW1.5 OPERATING SYSTEM CONCEPTS1.6 SYSTEM CALLS1.7 OPERATING SYSTEM ... accessmemory between the base and the limit. (b) Use of two base-limitpairs. The program code is between Base-1 and Limit-1 whereasthe data are between Base-2 and Limit-2.ClientprocessClientprocessProcessserverTerminalserverFileserverMemoryserverMicrokernelUser...
... 2-22. Entering and leaving a critical region using the TSLinstruction.Multiple user threadson a kernel threadUserspaceKernelspaceKernel threadKernelFig. 2-14. Multiplexing user-level threads ... of mutex lock and mutex unlock.2PROCESSES AND THREADS2.1 PROCESSES2.2 THREADS2.3 INTERPROCESS COMMUNICATION2.4 CLASSICAL IPC PROBLEMS2.5 SCHEDULING2.6 RESEARCH ON PROCESSES AND THREADS2.7 ... access*/}}Fig. 2-34. A solution to the readers and writers problem.BarrierBarrierBarrierA A AB B BC CDD DTimeTime TimeProcess(a) (b) (c)CFig. 2-30. Use of a barrier. (a) Processes approaching...
... t.(a) Operating systemA(b) Operating systemAB(c) Operating systemABC(d)Time Operating systemBC(e)D Operating systemBC(f)D Operating systemC(g)D Operating systemACFig. 4-5. Memory allocation changes as processes come intomemory and leave it. ... it. The shaded regions are unused memory.DiskMain memoryExternalpagerFaulthandlerUserprocessMMUhandler1. Page fault6. Mappage in 5. Here is pageUserspaceKernelspace2. Neededpage4. ... the set of pages used by the k mostrecent memory references. The function w(k, t) is the size of theworking set at time t.(a) Operating systemA(b) Operating systemAB(c) Operating systemABC(d)Time Operating systemBC(e)D Operating systemBC(f)D Operating systemC(g)D Operating systemACFig....
... I/O completedPerform I/O operationUser processesDevice-independentsoftwareDevice driversInterrupt handlers Hardware Fig. 5-16. Layers of the I/O system and the main functions of eachlayer.00123456712 ... (a) Separate I/O and memory space. (b) Memory-mappedI/O. (c) Hybrid.Spiral groovePitLand2K block ofuser dataFig. 5-20. Recording structure of a compact disc or CD-ROM.User-level I/O softwareDevice-independent ... boxrepresents one pixel. Operating system Operating systemDisk driver Printer driver Keyboard driver Disk driver Printer driver Keyboard driver(a) (b)Fig. 5-13. (a) Without a standard driver interface....
... in Windows98.6FILE SYSTEMS 6.1 FILES6.2 DIRECTORIES6.3 FILE SYSTEM IMPLEMENTATION6.4 EXAMPLE FILE SYSTEMS 6.5 RESEARCH ON FILE SYSTEMS 6.6 SUMMARYUserdirectoryUser subdirectoriesC CCC ... pointers to free disk blocksin memory and three blocks of pointers on disk. (b) Result of free-ing a three-block file. (c) An alternative strategy for handling thethree free blocks. The shaded ... 00123456789101112131415Block numberBlocks in use 0 0 1 0 1 0 0 0 0 1 1 0 0 0 1 1 Free blocks(a)1 1 0 1 0 1 1 1 1 0 0 1 1 1 0 00123456789101112131415Blocks in use 0 0 1 0 2 0 0 0 0 1 1 0 0 0 1 1 Free...
... blocks are read from diskFig. 7-19. Optimal frame placement for near video on demand.7MULTIMEDIA OPERATING SYSTEMS 7.1 INTRODUCTION TO MULTIMEDIA7.2 MULTIMEDIA FILES7.3 VIDEO COMPRESSION7.4 ... demand using different local distribution tech-nologies. (a) ADSL. (b) Cable TV.10 sec 1 min 2 min 3 min 4 min018003600540018003600540072007200User 10User ... seclaterTime01800360054007200User 1User 2Runs fasterNormal speed(a)(b)Runs slower Normal speed54007200180036000Fig. 7-23. (a) Two users watching the same movie 10...
... double torus. (e) A cube. (f) A 4Dhypercube.Runsusers and shared OSCPU 1Runsusers and shared OSCPU 2Runsusers and shared OSCPU 3Runsusers and shared OSOSCPU 4 MemoryI/OLocksBusFig. ... Accumulation of packet headers.8MULTIPLE PROCESSOR SYSTEMS 8.1 MULTIPROCESSORS8.2 MULTICOMPUTERS8.3 DISTRIBUTED SYSTEMS 8.4 RESEARCH ON MULTIPLE PROCESSOR SYSTEMS 8.5 SUMMARYNode 1 Node 2CPUCPUSwitch7234561100000010000000Bit ... gray.MasterrunsOSCPU 1Slaveruns userprocessesCPU 2Slaveruns userprocessesCPU 3UserprocessesOSCPU 4 MemoryI/OBusSlaveruns userprocessesFig. 8-8. A master-slave multiprocessor model.A...