资源描述：
《操作系统试卷os08(B) 东南大学 计算机学院 操作系统试卷》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、东南大学考试卷（B卷）自觉遵守考场纪律如考试作弊此答卷无效学号姓名密封线课程名称操作系统考试学期07-08-2得分适用专业计算机应用考试形式闭卷考试时间长度120分钟一、Definitions[5X6=30pts]Givethetechnicaltermthatbestfitsthesedefinitions1.Portionofaprogramthataccessessharedvariablesandthatnotwoprocessescanbeexecutingthiscodethatmanipulatessharedvariablesatthesametim
2、e.2.ItisamethodofoverlappingtheI/Oofajobwiththatjob’sowncomputation.Theideaissimple.Afterareadoperationcompletesandthejobisabouttostartoperatingonthedata,theinputdeviceisinstructedtobeginthenextreadimmediately.TheCPUandinputdevicearethenbothbusy.3.Somedevices,suchastapedrivesandprinter
3、s,cannotusefullymultiplextheI/0requestsofmultipleconcurrentapplications.Thesubsystemscancoordinateconcurrentoutputtoaseparatediskfile.Forinstance,Whenanapplicationfinishesprinting,thesubsystemcopiesthequeuedfilestotheprinterone,atatime.4.Unusedroutineisneverloaded.5.Aprocessisbusyswapp
4、ingpagesinandout.6.Asmalloperatingsystemcorethatprovidesbasicscheduling,memorymanagementandcommunicationserviceswhilerelyingonprocessestoperformtheotherrequiredfunctionalitytraditionallyassociatedwiththeoperatingsystem.共页第页二、Comparisons[6+9=15pts]CompletethefollowingcomparisonsusingTru
5、e,FalseorPossible1.[6pts]BlockingI/oversusNoblockingI/OPointofComparisonBlockingI/ONoblockingI/OI/OcallreturnsasmuchasavailableImplementedviamulti-threading2.[9pts]ThreadsversusprocessesPointofComparisonThreadsProcessesShareallglobalvariablesExecuteinseparateaddressspacesRequirelesstim
6、etocreate,terminateandswitchfromonetoanother三、Computing[10+12=22pts]1.Supposethatadiskdrivehas5000cylinders,numbered0to4999.Thedriveiscurrentlyservingarequestatcylinder143,andthepreviousrequestwasatcylinder125.Thequeueofpendingrequests,inFIFOorder,is86,1470,913,1774,948,1509,1022,1750,
7、130Startingfromthecurrentheadposition,whatisthetotaldistance(incylinders)thatthediskarmmovestosatisfyallthependingrequests,foreachofthefollowingdisk-schedulingalgorithms?[10pts]a.SSTFb.LOOK2.Considerthefollowingsetofprocesses,withthelengthoftheCPU-bursttimegiveninmilliseconds:Process
