vxworks嵌入式操作系統(tǒng)

嵌入式軟件VxWorks編程介紹

鄒昕光哈爾濱工業(yè)大學(xué)自動(dòng)化測(cè)控所聯(lián)系電話：86413531-609

E-mail：xgzou@vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第1頁(yè)!AgendaTaskIntertaskmunicationISRvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第2頁(yè)!TaskEachtaskhasitsowncontext,whichistheCPUenvironmentandsystemresourcesthatthetaskseeseachtimeitisscheduledtorunbythekernel.Atask’scontextissavedinthetaskcontrolblock(TCB).vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第3頁(yè)!TaskAtask’scontextincludes:-athreadofexecution;thatis,thetask’sprogramcounter-theCPUregistersand(optionally)floating-pointregisters-I/Oassignmentsforstandardinput,output,anderror-adelaytimer-atime-slicetimer-kernelcontrolstructures-signalhandlers-debuggingandperformancemonitoringvaluesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第4頁(yè)!TaskSchedulerControlRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第5頁(yè)!TaskControlRoutinevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第6頁(yè)!TaskSpawnvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第7頁(yè)!TaskInformationRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第8頁(yè)!TaskDeletingRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第9頁(yè)!TaskControlRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第10頁(yè)!SharedCodeandReentrancyAsinglecopyofcodeexecutedbymultipletasksiscalledsharedcode.Asubroutineisreentrantifasinglecopyoftheroutinecanbecalledfromseveraltaskcontextssimultaneouslywithoutconflict.Modifyglobalorstaticvariables.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第11頁(yè)!DynamicStackVariablesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第12頁(yè)!TaskVariablesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第13頁(yè)!SharedDataStructuresGlobalvariablesLinearbuffersRingbuffersLinkedlistsPointersvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第14頁(yè)!MutualExclusionDisableinterruptsDisablepreemptionResourcelockingwithsemaphoresvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第15頁(yè)!PreemptivelocksLessrestrictiveformofmutualexclusion.Noothertaskisallowedtopreemptivethecurrentexecutingtask,ISRareabletoexecute.Tasksofhigherpriorityareunabletoexecuteuntilthelockingtaskleavesthecriticalregion.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第16頁(yè)!SemaphoreControlRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第17頁(yè)!BinarySemaphorevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第18頁(yè)!BinarySemaphore-MutualExclusionvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第19頁(yè)!BinarySemaphore-Synchronizationvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第20頁(yè)!MutualSemaphore-RecursiveResourceAccessvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第21頁(yè)!CountingSemaphoresvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第22頁(yè)!MessageQueuesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第23頁(yè)!MessageQueueExamplevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第24頁(yè)!MessageQueueExamplevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第25頁(yè)!PipesPipesprovideanalternativeinterfacetothemessagequeuefacilitythatgoesthroughtheVxWorksI/Osystem.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第26頁(yè)!RPCRemoteProcedureCalls(RPC)isafacilitythatallowsaprocessonamachinetocallaprocedurethatisexecutedbyanotherprocessoneitherthesamemachineoraremotemachine.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第27頁(yè)!SignalSignalsasynchronouslyalterthecontrolflowofatask.AnytaskorISRcanraiseasignalforaparticulartask.Thetaskbeingsignaledimmediatelysuspendsitscurrentthreadofexecutionandexecutesthetask-specifiedsignalhandlerroutine.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第28頁(yè)!EventSendingandReceivingEvents Eventscanbesentfromaresourcetoatask,fromanISRtoatask,ordirectlybetweentwotasks.WaitingforEvents Ataskcanwaitformultipleeventsfromoneormoreresources.Eachsourcecansendmultipleevents,andataskcanalsowaittoreceiveonlyoneevent,orallevents.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第29頁(yè)!EventFreeResourceDefinitionMutexSemaphore -Amutexsemaphoreisconsideredfreewhenitnolongerhasanownerandnooneispendingonit.BinarySemaphore -Abinarysemaphoreisconsideredfreewhennotaskownsitandnooneiswaitingforit.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第30頁(yè)!EventSendingandReceivingEvents Eventscanbesentfromaresourcetoatask,fromanISRtoatask,ordirectlybetweentwotasks.WaitingforEvents Ataskcanwaitformultipleeventsfromoneormoreresources.Eachsourcecansendmultipleevents,andataskcanalsowaittoreceiveonlyoneevent,orallevents.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第31頁(yè)!WatchdogTimersCallsvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第32頁(yè)!EventRegisterRoutinevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第33頁(yè)!intConnectRoutinevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第34頁(yè)!Runashellvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第35頁(yè)!Cmandsinshellvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第36頁(yè)!ShellCommands:tdvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第37頁(yè)!ShellCommands:tivxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第38頁(yè)!ShellCommands:twvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第39頁(yè)!ShellCommands:dvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第40頁(yè)!ShellCommands:dvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第41頁(yè)!ShellCommands:pwd&cdvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第42頁(yè)!ShellCommands:rebootvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第43頁(yè)!ShellCommands:semaphorevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第44頁(yè)!ShellCommands:semaphorevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第45頁(yè)!ShellCommands:MessageQueuevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第46頁(yè)!ShellCommands:MessageQueuevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第47頁(yè)!ShellCommands:MessageQueuevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第48頁(yè)!TaskThedefaulttaskschedulingalgorithminwindispriority-basedpreemptivescheduling.RoundRobinisanoptionalalgorithm.Thewindkernelhas256prioritylevels,numbered0through255.Priority0isthehighestandpriority255isthelowest.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第49頁(yè)!TaskTaskLock WhenataskdisablestheschedulerbycallingtaskLock(),nopriority-basedpreemptioncantakeplacewhilethattaskisrunning. Ifthetaskexplicitlyblocksorsuspends,theschedulerselectsthenexthighest-priorityeligibletasktoexecute. Whenthepreemption-lockedtaskunblocksandbeginsrunningagain,preemptionisagaindisabled. ThetaskLock()preventtaskcontextswitching,butdonotlockoutinterrupthandling.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第50頁(yè)!TasktaskSpawnTaskNameandIDRoutinesTaskInformationRoutinesTaskDeletingRoutinesTaskControlRoutinesTaskHookRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第51頁(yè)!TaskNameandIDRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第52頁(yè)!TaskInformationRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第53頁(yè)!TaskDeletingRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第54頁(yè)!TaskHookRoutinesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第55頁(yè)!CodeReentrancySolutionsDynamicStackVariablesGuardedGlobalandStaticVariablesTaskVariablesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第56頁(yè)!GuardedGlobalandStaticVariablesProvidingamutual-exclusionmechanismtoprohibittasksfromsimultaneouslyexecutingcriticalsectionsofcode.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第57頁(yè)!IntertaskCommunicationSharedDataStructureMutualExclusionSemaphoresMessageQueuesPipesNetworkIntertaskCommunicationSignalsvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第58頁(yè)!SharedDataStructuresvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第59頁(yè)!DisableInterruptsThemostpowerfulmethodItpreventsthesystemfromrespondingtoexternaleventsforthedurationoftheselocks.Keepthedurationofinterruptlockoutsshort.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第60頁(yè)!SemaphoresHighlyoptimizedandprovidethefastestintertaskmunicationmechanisminVxWorks.ThreetypesofWindsemaphores: -Binary -Mutualexclusion -Countingvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第61頁(yè)!BinarySemaphorevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第62頁(yè)!BinarySemaphore-MutualExclusionvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第63頁(yè)!BinarySemaphore-Synchronizationvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第64頁(yè)!BinarySemaphore-Synchronizationvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第65頁(yè)!MutualSemaphore-RecursiveResourceAccessvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第66頁(yè)!MessageQueueMessagequeuesallowavariablenumberofmessages,eachofvariablelength,tobequeued.TasksandISRscansendmessagestoamessagequeue,andtaskscanreceivemessageformamessagequeue.Multipletaskscansendtoandreceivefromthesamemessagequeue.Full-duplexmunicationbetweentwotasksgenerallyrequirestwomessagequeues,oneforeachdirection.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第67頁(yè)!WindMessageQueueControlvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第68頁(yè)!MessageQueueExamplevxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第69頁(yè)!MessageQueuesvxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第70頁(yè)!SocketsInVxWorks,thebasisofintertaskmunicationacrossthenetworkissockets.VxWorkssupportstheInternetprotocolsTCPandUDP.TCPprovidesreliable,guaranteed,two-waytransmissionofdatawithstreamsockets.UDPprovidesasimplebutlessrobustformofmunication.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第71頁(yè)!SignalSignalsasynchronouslyalterthecontrolflowofatask.AnytaskorISRcanraiseasignalforaparticulartask.Thetaskbeingsignaledimmediatelysuspendsitscurrentthreadofexecutionandexecutesthetask-specifiedsignalhandlerroutine.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第72頁(yè)!EventVxWorkseventsaremeansofmunicationbetweentasksandinterruptroutine,betweentasksandothertasks,orbetweentasksandVxWorksobjects.VxWorksobjectsarereferredtoasresourcessuchassemaphoresandmessagequeue.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第73頁(yè)!EventRegisteringforEvents Onlyonetaskcanregisteritselftoreceiveeventsfromaresource.Ifanothertasksubsequentlyregisterswiththesameresource,thepreviouslyregisteredtaskisautomaticallyunregistered.FreeingResource Whenaresourcesendstoatasktoindicatethatitisfree,itdoesnotmeanthatresourceisreserved.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第74頁(yè)!EventFreeResourceDefinitionCountingSemaphore -Acountingsemaphoreisconsideredfreewhenitscountsisnonzeroandnooneispendingonit.MessageQueue -Amessagequeueisconsideredfreewhenamessagequeueispresentinthequeueandnooneispendingforthearrivalofamessageinthatqueue.vxworks嵌入式操作系統(tǒng)共93頁(yè)，您現(xiàn)在瀏覽的是第75頁(yè)!WatchdogTimersVxWorksincludesawatchdog-timermechanismthatallowsanyCfunctiontobeconnecttoaspecifiedtimedelay.Functioninvokedbywatchdogtimersexecuteasinterruptservicecodea