Chapter-4-Q&A

OperatingSystemsChapter4–Threads,SMP,andMicrokernelsPage1of6Chapter4–Threads,SMP,andMicrokernelsTrue/FalseQuestions:1.T/F–Thebasicunitofdispatchinginanoperatingsystemisusuallyreferredtoasathreadorlightweightprocess.ANS:T2.T/F–AnexampleofasystemthatimplementsasingleprocesswithmultiplethreadsisMS-DOS.ANS:F(Java)3.T/F–Inamultithreadedenvironment,aprocessisdefinedastheunitofresourceallocationandaunitofprotection.ANS:T4.T/F–Theconceptofthreadsynchronizationisrequiredinmultithreadedsystemsbecausethreadsofasingleprocesssharetheprocess’sprocesscontrolblock(PCB).ANS:F(becausetheysharethesameaddressspace)5.T/F–InapureUser-LevelThread(ULT)facility,alloftheworkofthreadmanagementisdonebytheapplication,butthekernelisawareoftheexistenceofthreads.ANS:F(kernelisnotawareofthethreadsexistence)6.T/F–Inthefieldofdistributedoperatingsystemdesign,theOne-to-Many(Thread-to-Process)relationshipisparticularlyinterestingbecauseitinvolvestheconceptofthreadmigration.ANS:T7.T/F–Onedisadvantagetothemaster/slaveshared-memorymultiprocessorarchitectureisthatthefailureofthemasterbringsdownthewholesystem.ANS:T8.T/F–Inasymmetricmultiprocessing(SMP)system,eachprocessorhasaccessonlytoaprivatemainmemoryarea.ANS:F(alsohaveaccesstoasharedmainmemory)9.T/F–AnSMPO/Smanagesprocessorandotherresourcessothattheusermayviewthesysteminthesamefashionasamultiprogramminguniprocessorsystem.ANS:T10.T/F–Theprimaryadvantageofthebasicmicrokerneldesignoverlayeredkerneldesignsinvolvesincreasedperformance.ANS:F(performanceisadisadvantage)OperatingSystemsChapter4–Threads,SMP,andMicrokernelsPage2of611.T/F–Thephilosophyunderlyingthemicrokernelisthatonlyabsolutelyessentialcoreoperatingsystemfunctionsshouldbeinthekernel.ANS:T12.T/F–ThebasicformofcommunicationbetweenprocessesorthreadsinamicrokernelO/Sismessages.ANS:T13.T/F–Linuxmakesnodistinctionbetweenaprocessandathread.ANS:T14.T/F–Windows2000isanobject-orientedO/S,butonlyprocesses(notthreads)areimplementedasobjectsintheWIN2KO/S.ANS:F(threadsarealsoimplementedasobjects)15.T/F–IntheSolarisO/S,aUser-LevelThread(ULT)intheactivestateisassignedtoaLight-WeightProcess(LWP)andexecuteswhiletheunderlyingkernelthreadexecutes.ANS:TMultipleChoiceQuestions:1.Theconceptofaprocessinanoperatingsystemembodiestwoprimarycharacteristics,oneofwhichis:a.Multithreadingb.Resourceownershipc.Symmetricmultiprocessingd.NoneoftheaboveANS:B2.Anexampleofasystemthatimplementsasingleprocesswithmultiplethreadsis:a.WIN2000b.Solarisc.Javad.AlloftheaboveANS:C3.Whichofthefollowingistrueregardingtherelationshipbetweenprocessesandthreads:a.Ittakesfarlesstimetocreateanewthreadinanexistingprocessthantocreateanewprocessb.Ittakeslesstimetoterminateaprocessthanathreadc.Ittakeslesstimetoswitchbetweentwodifferentprocessesthantoswitchbetweentwothreadswithinthesameprocessd.AlloftheaboveANS:AOperatingSystemsChapter4–Threads,SMP,andMicrokernelsPage3of64.Thebasicthreadoperationrelatedtothechangeinthreadstatethatoccurswhenathreadneedstowaitforaneventisreferredtoasthe:a.Unblockoperationb.Spawnoperationc.Blockoperationd.NoneoftheaboveANS:C5.OneofthedisadvantagesofUser-LevelThreads(ULTs)comparedtoKernel-LevelThreads(KLTs)is:a.Schedulingisapplicationspecificb.WhenaULTexecutesasystemcall,allthreadsintheprocessareblockedc.Threadswitchingdoesnotrequirekernelmodeprivilegesd.AlloftheaboveANS:B6.IntheLinuxO/S,multiplethreadsmaybecreatedandexecutedwithinasingleprocess.ThisisanexampleofthefollowingThread-to-Processrelationship:a.1:1b.1:Mc.M:Nd.NoneoftheaboveANS:D(M:1)7.Thecomputersystemcategorywhereasingleprocessorexecutesasingleinstructionstreamtooperateondatastoredinasinglememoryiscalled:a.SingleInstructionSingleData(SISD)streamb.SingleInstructionMultipleData(SIMD)streamc.MultipleInstructionSingleData(MISD)streamd.NoneoftheaboveANS:A8.InaSMPsystem,eachprocessormaintainsalocalcacheandmustalertallotherprocessorsthatachangetocacheupdatehastakenplace.Thisisreferredtoasthe:a.Interconnectionmechanismproblemb.Synchronizationmechanismproblemc.Cachecoherencyproblemd.NoneoftheaboveANS:C9.Keyissuesinvolvedinthedesignofmultiprocessoroperatingsystemsinclude:a.Schedulingb.SynchronizationOperatingSystemsChapter4–Threads,SMP,andMicrokernelsPage4of6c.Reliabilityandfaulttoleranced.AlloftheaboveANS:D10.Earlyoperatingsystemsthatweredesignedwithlittleconcernaboutstructurearetypicallyreferredtoas:a.Monolithicoperatingsystemsb.Layeredoperatingsystemsc.Kerneloperatingsystemsd.AlloftheaboveANS:A11.Abenefitofthemicrokernelorganizationis:a.Extensibilityb.Portabilityc.Flexibilityd.AlloftheaboveANS:D12.Inlow-levelmicrokernelmemorymanagement,anexampleofanoperationthatcansupportexternalpagingandvirtualmemorymanagementisthe:a.Grantoperationb.Mapoperationc.Flushoperationd.AlloftheaboveANS:D13.InaW2Ksystem,thestatethatathreadenterswhenithasbeenunblockedandtheresourceforwhichithasbeenblockedisnotyetavailableiscalledthe:a.Transitionstateb.Waitingstatec.Standbystated.NoneoftheaboveANS:A14.InaSolarissystem,aUser-LevelThread(ULT)thatenterstheactivestateisassignedtoa:a.Kernelthreadb.Heavy-WeightProcess(HWP)c.Light-WeightProces