电机资讯工程实习个人电脑系统(英文版)

1,EE110300電機資訊工程實習Lecture3個人電腦系統II-OperatingSystems,2,Whatisanoperatingsystem?Definition,Anoperatingsystemisthe“permanent”softwarethatcontrols/abstractshardwareUserapplicationscanthusbesimpleranddevice-independent,physicalmachineinterface,UserApplications,OperatingSystem,Architecture,virtualmachineinterface,3,Whatisanoperatingsystem?Definition(cont),ManagesresourcesandprocessestosupportdifferentuserapplicationsProvidesApplicationsProgrammingInterface(API)foruserapplications,UserApplication,OperatingSystem,Architecture,UserApplication,4,Modernoperatingsystems,x86platformLinuxWindowsMacplatformMacOSSunSolaris,BorlandClibrary:Intprintf()/callSysOutputString,/providedbyNT/systemlibrary,to/printonthescreenSysOutputString();,NTlibrary:VoidSysOutputString()/callNtOutputString,thatinturnwillcall/videocarddrivertooutputstringsto/thescreenNtOutputString();,12,Systemservicecall(disk),CPrograms:main()/callCreateFile/bytheClibrary,to/createafileondiskCreateFile(“a.txt”),BorlandClibrary:IntCreateFile()/callNtCreateFile,/providedbyNTto/createafileNtCreateFile();,NTlibrary:VoidNtCreateFile()/callNtInternalCreateFile,thatinturnwill/callthefilesystemdriverandthedisk/drivertocreateafileonadiskNtInternalCreateFile();,13,Systemservicecalls(network),CPrograms:main()so=createsocket();send(so,“text”);close(so);,BorlandClibrary:intcreatesocket()NtCreateSocket();intsend()NtSocketSend();,NTlibrary:VoidNtCreateSocket()NtAfdCreateSocket();,14,15,Virtualcomputerconcept,C+compiler,FORTRANcompiler,Ccompiler,Javacompiler,Assembler,OperatingSystemCommandinterpreter,LISPinterpreter,Operatingsystem,Macroinstructioninterpreter,Baremachine,VirtualCComputer,VirtualC+Computer,16,Importanceofoperatingsystem,SystemAPIaretheonlyinterfacebetweenuserapplicationsandhardwareAPIaredesignedforgeneral-purpose,notperformancedriven(workapplications)OScodecannotallowanybugAnybreak(e.g.invalidaccess)causesrebootTheownerofOStechnologycontrolsthesoftwareindustry,17,WhatisEmbeddedSystem?,是電腦軟體與硬體的綜合體,亦可涵蓋機械或其他附屬裝置;整個綜合體設計的目的,在於滿足某種特殊功能.例如:PDA,遊樂器,衛星導航系統,流程管理器等.,18,Embeddedsystemarchitecture,3-layereddevicePalm,PocketPC,UserApplications,EmbeddedOS,Hardware,2-layereddeviceXBox,Hardware,Application,19,General-purpose&embeddedOS,20,Operatingsystemconcepts,21,Process&Thread,Howdodifferentapplicationsrunonthesamemachineatthesametimewithoutinterferingeachother?ProtectionbetweenprocessesProtectionbetweenaprocessandtheOSProcess:anexecutionofaprogram,consistingofavirtualaddressspace,oneormorethreads,andsomeOSstates.,22,Virtualmemory(addressspace),virtualaddressspace(4GB),page0,page1,page2,page220,physicalmemory(16MB),pp0,pp1,pp2,ppN,pagingfile,pp212,x,23,Virtualmemory(addressspace),virtualaddressspace(4GB),page0,page1,page2,page220,physicalmemory(16MB),pp0,pp1,pp2,ppN,pagingfile,pp212,24,Memorymanager,physicalmemory,pp0,pp1,pp2,ppN,pagingfile,pp212,processVA,processVA,PT,PT,25,Memorymanager,physicalmemory,pp0,pp1,pp2,ppN,pagingfile,pp212,processVA,processVA,PT,PT,26,Memorymanager(w/constraint),physicalmemory,pp0,pp1,pp2,ppN,pagingfile,pp212,processVA,processVA,PT,PT,x,memorymanager,27,Protectiondualmodeoperation,Canapplicationmodifyitsownpagetable?Ifitcould,couldgetaccesstoallphysicalmemory.DualModeKernel/protectedmodel:norestriction,cantouchanyphysicalmemorypageUsermode:whereyouprogramruns,canonlytouchpartofthevirtualaddressspaceApplicationscanenterthekernelmodethroughsystemscalls(traps),28,Modechange:systemcalltrap,1.Systemcalltrapstothekernel(kernelmode)2.Kerneldeterminesserviceroutinerequired3.Kernelservicesthecall.4.Controlisreturnedtouserprogram(usermode),29,Thread,Aprocessstartswithonethread(mainthread),andcaninitializemorethreadsbyCreateThread()callsAthreadrepresentsanexecutionstreamofinstructionsanditsCPUregistercontextAthreadistheunitusedintheschedulerKillaprocesskillitsallthreads,30,Scheduler,AcomponentinOSthatdecideswhichthreadinthethreadpoolgetstheCPUPriority-basedschedulerContextswitch,newthread,terminatingthreads,signalevents,31,Synchronization,AllthreadsinthesameprocessshareallglobaldataSynchronizationamongthesethreadsisnecessarytomaintaindataintegrityResourcelockiscommonlyusedtoguaranteethreadmutualexclusiveabuseofsuchlocksdecreasesscalabilityignoranceofsuchlocksdecreasesstabilityDeadlockissues,32,FileSystems,AharddiskisjustarawmediastorageAharddiskdevicedriverallowsOStocommunicatewiththehardwareBut,itistheresponsibilityoftheOStoorganizedisksectors/tracksforstoringfilessuchcomponentiscalledthefilesystemE.g.AharddiskthatstoresNTFSinformationcannotbereadwiththeFAT32driverexample:paperwithMosescode,33,OperatingSystemsandSystemSoftware,Example:webserversoftware,34,User-modewebserverarchitecture,UserMode,KernelMode,I/Omodule,35,User-modewebservercommons,User-modeapplicationarchitecturee.g.MicrosoftInternetInformationServer(IIS),NetscapeEnterpriseServer,ApacheHTTPServer,etc.DependentongenerallysystemAPIStand-alonewebcontentcachelimitedbyvirtualaddressspaceTime-to-livecachereplacementalgorithmMemory-lessdynamiccodeexecution,36,SWCwebserverarchitecture,UserMode,KernelMode,networkcard+,SystemCache,miss,37,SPECWEB99Performance,*estimatedscalingdata,38,Kernelvs.user-b