盘算机专业英语第5章.ppt

ComputerEnglishKeypoints:FunctionandstructureofOperatingSystemDifficultpoints: Resourceallocationandrelatedfunctions
UserinterfacefunctionsRequirements:NewWords&Expressions:
OS(OperatingSystem)操作系统 bindingn.捆绑
mutualinterference相互干扰 interfacen.界面，接口
facilitatevt.推动,帮助，促进 allocationn.分配,安置
constraintn.约束,强制,局促 criterian.标准
embodyvt.具体表达,使具体化 entryn.条目，登录
privilegen.特权；vt.给与...特权 partitionvt.分区
approachn.方法,途径 apriori预先,事前
perceivev.感知,感到,认识到 preemptionn.抢占
suboptimaladj.未达最佳标准的 entrustv.委托
sequentialadj.顺序的,串行的 exclusiveuse专用
concurrentadj.并发的,并行的 de-allocatevt.释放
schedulingn.调度 salientfeatures特征,特色
initiatevt.vi.开始,发动OSfunctionscanbeclassifiedinto
Resourceallocationandrelatedfunctions
Userinterfacefunctions.
Theresourceallocationfunctionimplementsresourcesharingbytheusersofacomputersystem.Basically,itperformsbindingofasetofresourceswitharequestingprogram,thatis,itassociatesresourceswithaprogram.Therelatedfunctionsimplementprotectionofuserssharingasetofresourcesagainstmutualinterference.Theuserinterfacefunctionfacilitatescreationanduseofappropriatecomputationalstructuresbyauser.Thisfunctiontypicallyinvolvestheuseofacommandlanguageoramenu.Theresourceallocationfunctionallocatesresourcesforusebyauser'scomputation.ResourcescanbedividedintosystemprovidedresourceslikeCPUs,memoryareasandIOdevices,oruser-createdresourceslikefileswhichareentrustedtotheOS.Resourceallocationcriteriadependonwhetheraresourceisasystemresourceorauser-createdresource.Allocationofsystemresourcesisdrivenbyconsiderationsofefficiencyofresourceutilization.Allocationofuser-createdresourcesisbasedonasetofconstraintsspecifiedbyitscreatorandtypicallyembodiesthenotionofaccessprivileges.Twopopularstrategiesforresourceallocationare:
Partitioningofresources
AllocationfromapoolIntheresourcepartitioningapproach,theOSdecidesaprioriwhatresourcesshouldbeallocatedtoausercomputation.Thisapproachiscalledstaticallocationbecausetheallocationismadebeforetheexecutionofaprogramstarts.Staticresourceallocationi