計算機(jī)操作系統(tǒng)教程(第一版)

References計算機(jī)操作系統(tǒng)教程(第一版）周長林，左萬歷.高等教育出版社，1994.9計算機(jī)操作系統(tǒng)教程（第二版）左萬歷，周長林.高等教育出版社，2004.7OperatingSystemConceptsA.Silberschatz,et.al.5thedition,Wiley.AppliedOperatingSystemConceptsModule1:IntroductionWhatisanoperatingsystem?SimpleBatchSystemsMultiprogrammingBatchedSystemsTime-SharingSystemsPersonal-ComputerSystemsParallelSystemsDistributedSystemsReal-TimeSystemsEmbeddedsystemAppliedOperatingSystemConceptsWhatisanOperatingSystem?Aprogramthatactsasanintermediarybetweenauserofacomputerandthecomputerhardware.Operatingsystemgoals:Managesystemresources,resolveconflictamongapplicationprograms.Usethecomputerhardwareinanefficientmanner.Executeuserprogramsandmakesolvinguserproblemseasier.Makethecomputersystemconvenienttouse.AppliedOperatingSystemConceptsComputerSystemComponentsHardware–providesbasiccomputingresources(CPU,memory,I/Odevices).Operatingsystem–controlsandcoordinatestheuseofthehardwareamongthevariousapplicationprogramsforthevarioususers.Applicationsprograms–compilers,databasesystems,videogames,businessprograms.userconstructedprogramUsers(people,applicationprograms,othercomputers).AppliedOperatingSystemConceptsAbstractViewofSystemComponentsAppliedOperatingSystemConceptsOperatingSystemDefinitionsResourceallocator–managesandallocatesresources.Controlprogram–controlstheexecutionofuserprogramsandoperationsofI/Odevices.Serviceprogram–provideservicesforvariousapplicationprograms.Kernel–theoneprogramrunningatalltimes(allelsebeingapplicationprograms).AppliedOperatingSystemConceptsSimpleBatchSystemsHireanoperatorUseroperatorAddtocardreaderReducesetuptimebybatchingjobsAutomaticjobsequencing–automaticallytransferscontrolfromonejobtoanother.Firstrudimentaryoperatingsystem.ResidentmonitorinitialcontrolinmonitorcontroltransferstojobwhenjobcompletescontroltransfersbacktomonitorAppliedOperatingSystemConceptsMemoryLayoutforaSimpleBatchSystemAppliedOperatingSystemConceptsControlCardsProblems1. Howdoesthemonitorknowaboutthenatureofthejob(e.g.,FortranversusAssembly)orwhichprogramtoexecute?2. Howdoesthemonitordistinguish

(a)jobfromjob?

(b)datafromprogram?SolutionIntroducecontrolcardsAppliedOperatingSystemConceptsControlCards(Cont.)Specialcardsthattelltheresidentmonitorwhichprogramstorun

$JOB

$FTN

$RUN

$DATA

$ENDSpecialcharactersdistinguishcontrolcardsfromdataorprogramcards:

$incolumn1

//incolumn1and2

AppliedOperatingSystemConceptsControlCards(Cont.)PartsofresidentmonitorControlcardinterpreter–responsibleforreadingandcarryingoutinstructionsonthecards.Loader–loadssystemsprogramsandapplicationsprogramsintomemory.Devicedrivers–knowspecialcharacteristicsandpropertiesforeachofthesystem’sI/Odevices.Problem:SlowPerformance–I/OandCPUcouldnotoverlap;cardreaderveryslow.Solution:Off-lineoperation–speedupcomputationbyloadingjobsintomemoryfromtapescardreadingandlineprintingdoneoff-line.AppliedOperatingSystemConceptsSpoolingOverlapI/Oofonejobwithcomputationofanotherjob.Whileexecutingonejob,theOS.

Readsnextjobfromcardreaderintoastorageareaonthedisk(jobqueue).Outputsprintoutofpreviousjobfromdisktoprinter.Jobpool–datastructurethatallowstheOStoselectwhichjobtorunnextinordertoincreaseCPUutilization.AppliedOperatingSystemConceptsMultiprogrammedBatchSystemsSeveraljobsarekeptinmainmemoryatthesametime,andtheCPUismultiplexedamongthem.AppliedOperatingSystemConceptsOSFeaturesNeededforMultiprogrammingI/Oroutinesuppliedbythesystem.Memorymanagement–thesystemmustallocatethememorytoseveraljobs.CPUscheduling–thesystemmustchooseamongseveraljobsreadytorun.Allocationofdevices.AppliedOperatingSystemConceptsTime-SharingSystems–InteractiveComputingTheCPUismultiplexedamongseveraljobsthatarekeptinmemoryandondiskCPUisallocatedtoajobonlyifthejobisinmemory.Ajobisswappedinandoutofmemorytothedisk.On-linecommunicationbetweentheuserandthesystemisprovided;Inthemannerof“conversation”.On-linesystemmustbeavailableforuserstoaccessdataandcode.AppliedOperatingSystemConceptsPersonal-ComputerSystemsPersonalcomputers–computersystemdedicatedtoasingleuser.I/Odevices–keyboards,mice,displayscreens,smallprinters.Userconvenienceandresponsiveness.Canadopttechnologydevelopedforlargeroperatingsystem’oftenindividualshavesoleuseofcomputeranddonotneedadvancedCPUutilizationorprotectionfeatures.AppliedOperatingSystemConceptsMigrationofOperating-SystemConceptsandFeaturesAppliedOperatingSystemConceptsParallelSystemsMultiprocessorsystemswithmorethanoneCPUinclosecommunication.Tightlycoupledsystem–processorssharememoryandaclock;communicationusuallytakesplacethroughthesharedmemory.Advantagesofparallelsystem:IncreasedthroughputEconomical

Increasedreliabilitygracefuldegradationfail-softsystemsAppliedOperatingSystemConceptsParallelSystems(Cont.)Symmetricmultiprocessing(SMP)Eachprocessorrunsanidenticalcopyoftheoperatingsystem.Manyprocessescanrunatoncewithoutperformancedeterioration.MostmodernoperatingsystemssupportSMPWindowsNT,Solaris,DigitalUNIX,OS/2,LinuxAsymmetricmultiprocessingEachprocessorisassignedaspecifictask;masterprocessorschedulesandallocatesworktoslaveprocessors.MorecommoninextremelylargesystemsAppliedOperatingSystemConceptsSymmetricMultiprocessingArchitectureAppliedOperatingSystemConceptsReal-TimeSystemsOftenusedasacontroldeviceinadedicatedapplicationsuchascontrollingscientificexperiments,medicalimagingsystems,industrialcontrolsystems,andsomedisplaysystems.Well-definedfixed-timeconstraints.Hardreal-timesystem.Secondarystoragelimitedorabsent,datastoredinshort-termmemory,orread-onlymemory(ROM)deadlinescheduling.Softreal-timesystemLimitedutilityinindustrialcontrolorroboticsUsefulinapplications(multimedia,virtualreality)requiringadvancedoperating-systemfeatures.AppliedOperatingSystemConceptsDistributedSystemsDistributethecomputationamongseveralphysicalprocessors.Looselycoupledsystem–eachprocessorhasitsownlocalmemory;processorscommunicatewithoneanotherthroughvariouscommunicationslines,suchashigh-speedbusesortelephonelines.Advantagesofdistributedsystems.ResourcesSharingComputationspeedup–loadsharingReliabilityCommunicationsAppliedOperatingSystemConceptsDistributedSystems(Cont.)NetworkOperatingSystemprovidesfilesharing