操作系統(tǒng)-精髓與設(shè)計原理英文原版Ch計算機(jī)系統(tǒng)概述

OperatingSystem-EssenceandDesignPrinciplesEIntroductiontoOperatingSystemThecoreconceptsofoperatingsystemsThestructureandworkingprincipleoftheoperatingsystemSecurityandstabilityofoperatingsystemscontents目錄OptimizationandperformanceimprovementofoperatingsystemsTheDevelopmentTrendsandChallengesofFutureOperatingSystemscontents目錄IntroductiontoOperatingSystem01Anoperatingsystemisasoftwareprogramthatmanagesandcontrolsthecomputersystem'sresources,providesauserinterface,andactsasanintermediarybetweentheuserandthecomputerhardware.DefinitionTheoperatingsystemperformsvariousfunctionssuchasmanagingmemory,processingtasks,controllingperipherals,andprovidinganinterfaceforuserstointeractwiththecomputersystem.FunctionsDefinitionandFunctionofOperatingSystemThefirstoperatingsystemsweredevelopedinthe1950sandweredesignedtocontrolandmanagecomputerhardwareresources.SomeoftheearlyoperatingsystemsincludeUNIVAC'sOS,ENIAC'sBINAC,andMULTICS.EarlyoperatingsystemsWiththedevelopmentofmicroprocessorsandpersonalcomputersinthe1970sand1980s,modernoperatingsystemssuchasUNIX,Linux,andMacOSXemerged.Theseoperatingsystemsaredesignedtobemoreuser-friendly,efficient,andprovidearichsetoffeaturesandfunctionalities.ModernoperatingsystemsTheHistoryandDevelopmentofOperatingSystemsDifferenttypesofoperatingsystemsTheseoperatingsystemsaredesignedtobeusedforawiderangeoftasks,includingwordprocessing,graphicsdesign,webdevelopment,andgaming.SomeexamplesincludeWindows,macOS,andLinux.General-purposeoperatingsystemsTheseoperatingsystemsaredesignedforspecifictasksorindustries.Theymayprovideoptimizedperformanceorfeaturesthataretailoredtothespecificneedsoftheindustryortask.Someexamplesincludeembeddedoperatingsystems,real-timeoperatingsystems,andgamingconsoles.SpecializedoperatingsystemsThecoreconceptsofoperatingsystems02ProcessdefinitionAprocessistheexecutionofaprogram.Itinvolvesfetchinganddecodingtheinstructions,andmanagingthedata.ProcesscreationWhenaprogramisloadedintomemory,itisrepresentedasaprocess.TheprocessisassigneduniqueidentificationcalledPID.ProcessterminationWhenaprocesscompletesitsexecutionorisstoppedbythesystem,itisterminated.Theresourcesassociatedwiththeprocessarefreed.Processmanagement要點三VirtualmemoryItprovideseachprocesswithauniformandcontiguousaddressspace.Itallowsmappingofthephysicalmemoryintotheaddressspaceoftheprocess.要點一要點二MemoryallocationThememoryisallocatedtotheprocessesbasedontheirneedsandrequirements.Memoryallocationmechanismsincludestaticallocation,dynamicallocation,andsegmentation.MemoryprotectionItensuresthateachprocesscanonlyaccessitsallocatedmemoryandcannotaccessotherprocesses'memoryorthememoryareasreservedfortheoperatingsystem.要點三MemorymanagementThefilesystemprovidesamethodforstoringandretrievingdataonapermanentbasis,suchasharddisksorflashdrives.FilestorageDifferenttypesoffilesincludeexecutablefiles,sourcecodefiles,binaryfiles,imagefiles,audiofiles,videofiles,etc.FiletypesCommonfileoperationsincludecreatingafile,deletingafile,copyingafile,movingafile,renamingafile,etc.FileoperationsFilesystemDevicetypesDifferenttypesofdevicesincludeinputdevices(keyboard,mouse),outputdevices(display,printer),storagedevices(harddisk,flashdrive),networkdevices(NIC),etc.DriverresponsibilitiesAdevicedriverisasoftwarecomponentthatmanagestheinteractionbetweentheoperatingsystemandthedevice.Ithandlesdevice-specificrequestsandtranslatesthemintodevice-specificcommands.DriverinstallationandconfigurationDevicedriversareinstalledandconfiguredduringtheinstallationoftheoperatingsystemorlater.Theyareresponsibleformanagingdeviceresourcesandprovidinganinterfacetoaccessthedevice.DeviceDrivers010203UserinterfacetypesDifferenttypesofuserinterfacesincludecommand-lineinterface(CLI),graphicaluserinterface(GUI),voiceuserinterface(VUI),etc.UserinterfacedesignprinciplesDesignprinciplesforuserinterfacesincludesimplicity,consistency,feedback,affordance,etc.Theseprincipleshelptocreateuser-friendlyinterfacesthatareeasytouseandintuitive.UserinterfaceevolutionTheevolutionofuserinterfaceshasledtomoreadvancedandinteractiveinterfacesthatprovidebetterusabilityanduserexperience.UserinterfaceThestructureandworkingprincipleoftheoperatingsystem03Thecoreoftheoperatingsystem,responsibleformanaginghardwareresourcesandprovidingsystemservicestoapplications.KernelProvidecommonlyusedfunctionsandservices,suchasinput/outputoperations,memorymanagement,andnetworkcommunication.SystemlibrariesProvidevarioustoolsandapplicationsthathelpusersperformtasks,suchasfilecompression,encryption,andsystemmonitoring.UtilitiesThestructureoftheoperatingsystem

StartupandinitializationoftheoperatingsystemBootloaderLoadtheoperatingsystemkernelintomemoryandinitializethehardware.KernelinitializationInitializesystemdevices,drivers,andotherkernelcomponents.StartupscriptsExecutescriptstoinitializesystemservicesandstartbackgroundprocesses.Thekernelthenhandlestherequestandreturnstheresulttotheapplication.Systemcallsaretheinterfacebetweenapplicationprogramsandthekernel.Whenanapplicationneedstouseasystemresourceorperformaprivilegedoperation,itmakesasystemcalltorequestthekernel'sassistance.TheworkingprincipleofsystemcallsTheoperatingsystemshutsdowninanorderlymannertoensurethatallopenfilesareclosedproperlyandthatanypendingoperationsarecompleted.Thesystemthenshutsdownanybackgroundservicesandperformscleanupoperations,suchasflushingfilesystemcaches.Finally,theoperatingsystempowersoffthecomputerorentersalow-powerstate.Thekernelsendsashutdownsignaltoallprocessesandtellsthemtoterminate.ShutdownoftheoperatingsystemSecurityandstabilityofoperatingsystems04Accesscontrol01Operatingsystemsshouldhavestrictaccesscontrolmechanismstopreventunauthorizedusersfromaccessingsensitivedataorexecutingunauthorizedoperations.Encryption02Datastoredonthesystemshouldbeencryptedtoensureitsconfidentialityandintegrity.Patchmanagement03Regularupdatesandpatchesshouldbeappliedtotheoperatingsystemtoaddresssecurityvulnerabilitiesandimprovesecurity.SecurityoftheoperatingsystemFaulttoleranceTheoperatingsystemshouldhavefaulttolerancemechanismstoensurethatcriticalservicesremainavailableincaseofhardwarefailuresorotherissues.ResourcemanagementTheoperatingsystemshouldhaveeffectiveresourcemanagementmechanismstoensurethatsystemresourcesareallocatedefficientlyandfairly.StabilitytestingOperatingsystemsshouldundergorigorousstabilitytestingtoidentifyandaddresspotentialissuesthatcouldaffectsystemstability.ThestabilityoftheoperatingsystemFirewallsFirewallsshouldbeconfiguredtoblockunauthorizednetworktrafficandpreventexternalattacks.AntivirussoftwareAntivirussoftwareshouldbeinstalledandregularlyupdatedtodetectandremovemalicioussoftware.SecurityauditsRegularsecurityauditsshouldbeconductedtoidentifyvulnerabilitiesintheoperatingsystemandaddressthempromptly.MeasurestopreventvirusandhackerattacksOptimizationandperformanceimprovementofoperatingsystems05Operatingsystemscanoptimizeresponsetimebyschedulingtasksandallocatingresourcesefficiently.Techniquessuchascontextswitchingandinterrupthandlingcanhelpreducethedelayinprocessinguserrequests.Operatingsystemsmanagevarioussystemresources,suchasCPU,memory,andI/Odevices,toensureefficientutilization.Resourcemanagementtechniqueslikeresourcepooling,preemption,anddeferralcanimprovesystemperformance.Loadbalancingisatechniqueusedtodistributetheworkloadevenlyacrossmultipleresourcesorserverstooptimizeresourceutilizationandimproveoverallsystemperformance.ImprovingsystemresponsetimeEfficientresourcemanagementLoadbalancingPerformanceoptimizationofoperatingsystemsOperatingsystemsusetaskschedulingalgorithmstodeterminetheorderinwhichtasksareexecutedbytheCPU.Schedulingalgorithmssuchasround-robin,priorityscheduling,andmultilevelfeedbackqueueschedulingcanoptimizesystemperformance.Operatingsystemsassigndifferentprioritiestotasksbasedontheirimportanceorurgency.Higher-prioritytasksareexecutedfirst,ensuringthatcriticalworkloadsarecompletedpromptly.Incooperativemultitasking,taskssharetheCPUbyvoluntarilyrelinquishingcontrolwhentheyhavefinishedtheirworkorwhentheyareblocked.Thisapproachrequirestaskstobewell-behavedandresponsivetosystemrequests.TaskschedulingPrioritymanagementCooperativemultitaskingMultitaskprocessingandprioritymanagementEffectiveutilizationandmanagementofsystemresourcesResourceallocation:OperatingsystemsallocateresourcessuchasCPU,memory,andI/Odevicestotasksbasedontheirneedsandpriority.Effectiveresourceallocationensuresthatresourcesareutilizedefficientlyandpreventsresourcestarvationoroverutilization.Resourcepooling:Resourcepoolinginvolvescreatingacommonpoolofresourcesthatcanbesharedbymultipletasks.Thisapproachhelpsinloadbalancing,reducestheoverheadofresourceinitialization,andimprovessystemscalability.Resourcemonitoringandaccounting:Operatingsystemsmonitortheusageofsystemresourcesandprovideaccountinginformationtousersandadministrators.Resourcemonitoringhelpsinidentifyingbottlenecksandoptimizingresourceutilization,whileresourceaccountingprovidesinformationforresourceallocationdecisions.TheDevelopmentTrendsandChallengesofFutureOperatingSystems06DistributedcomputingOSDesignedfordistributedcomputingenvironments,whereresourcesaresharedacrossmultipledevices.Itenablesefficientresourcemanagement,faulttolerance,a