对于设备驱动程序通知应用程序的措施.doc

对于设备驱动程序通知应用程序的措施 论文题目：对于设备驱动程序通知应用程序的几种方法 外文翻译ThedevicedrivernotifiestheapplicationofseveralmethodsInthecurrentpopularWindowsoperatingsystem,devicedriversisthelowestlevelofmanipulationofhardwaresoftwareinterface.Tosharethedevicedriverdesignprocessexperience,giventhedevicedrivernotifiestheapplicationofthefivekindsofways,eachmethodspecificallydescribedtheprincipleandimplementationprocess,hopingtogivethedesignerofthedevicedrivertoprovidesomehelp.Operatingsysteminordertoensurepeaceandstability,andapplicationportability,Windowsoperatingsystemdoesnotallowapplicationsdirectaesstothesystemshardwareresources,butmustresorttotheappropriatedevicedriver.Devicedriverscandirectlymanipulatethehardware,ifapplicationsanddevicedriverstoachieveatwo-waymunicationbetween,alsoreachedtheunderlyinghardwaredeviceapplicationcontrolpurposes.Communicationbetweenthem,includingtwoaspectsAbstract:Ontheonehandistheapplicationsenttothedevicedriverdata;handisthedevicedriversendsamessagetotheapplication.TheformertoachievemoreeasilythroughCreateFile()functiontoobtainahandletothedevicedriver,youcanusetheWin32functionssuchasDeviceIoControl(),ReadFile()orWriteFile(),etc.toachieveapplicationanddevicedrivermunication.Implementationofthelatterthantheformerplexandthearticledescribesthesituationinthisrespectless.Thisdoesnotmeanthatitisnotimportant,onthecontrary,itisinsomeapplicationsplayan importantfunction.Devicedriverspletethedatacollectionwork,theneedtoimmediatelynotifytheapplicationsothattheapplicationcanbepromptlyremovedandthedataisprocessed.Incaseslikethese,andsoforth.Inviewofthedevicedrivernotifiestheapplicationoftheimportance,Ibinedsomeexperience,itwassummarizedsummarizedfivemethodsAbstract:asynchronousprocedurecall(APC),eventmode(VxD),messaging,asynchronousI/Omodesandeventmode(WDM).Belowweretheprinciplesofthisinseveralways,andgivenofsomeofthesourcecode.AnAsynchronousProcedureCall(APC)Win32applicationsusingCreateFile()functiontodynamicallyloadthedevicedriver,andthendefineacallbackfunctionbackFunc(),andtheaddressofthecallbackfunction%26amp;backFunc()asaparameter,throughDeviceIoControl()senttothedevicedriver.Devicedriverstogettheaddressofacallbackfunction,itwillsaveitinaglobalvariable(egcallback),thesimultaneouscallsGet_Cur_Thread_Handle()functiontogetitsapplicationthreadhandle,andthehandleisstoredinaglobalvariable(egappthread)in.Whenconditionsareripe,thedevicedrivercalls_VWIN32_QueueUserApc()functiontosendmessagestotheWin32application.ThisfunctiontakesthreeargumentsAbstract:Thefirstparameteristheaddressofthecallbackfunction(alreadyregistered);secondparameterispassedtothecallbackmessage;thirdparametertothecallersthreadhandle(alreadyregistered).Win32applicationreceivesamessage,theautomaticcallbackfunction(actuallycalledbythedevicedriver).Callbackfunctionoftheinputparametersarepopulatedbythedevicedriver,thecallbackfunctionhereismainlytohandlethemessage.2EventMode(VxD) First,Win32applicationstocreateaneventhandler,calledRing3 handle.BecausethevirtualdevicedriverusingeventsRing0handle,soyouneedtocreateRing0handle.UsingLoadLibrary()functiontoloadthedynamiclinklibraryundisclosedKernel32.dll,getdynamiclinklibraryhandle.Then,callGetProcAddress(),findthefunctionOpenVxDHandle()inthedynamiclinklibrarylocation.Then,OpenVxDHandle()functionwillRing3eventhandlersintoRing0eventhandler.Win32applicationsusingCreateFile()functiontoloadthedevicedriver.Iftheloadissuessful,calltheDeviceIoControl()functionwillbepassedtotheeventhandlerRing0VxD;whilewaitingforthesignaltocreateaworkerthreadbeessignaledstateitselfcanshopandotherthings.Whenconditionsareripe,VxDsetRing0eventtosignaledstate(called_VWIN32_SetWin32Event()function),whichcorrespondstoRing3immediatelytriggereventtosignaledstate.OnceRing3eventhandlerforthesignaledstate,Win32applicationsworkerthreadonthisnewsbehandledaordingly.3MessageModeWin32applicationcallsCreateFile()functiontodynamicallyloadthevirtualdevicedriver.Loadedsuessfully,bycallingDeviceIoControl()functionhandlestheformsenttoVxD,VxDusethishandletoformamessage.Whentheconditionsaremet,VxDcallsSHELL_PostMessage()functiontosendmessagestoWin32applications.Tomakeuseofthisfunctionsuessfully,youmustuse#definetocustomizeamessage,andevensoitisdefinedintheapplication;alsousedinthemessageloopON_MESSAGE()todefinethemessageprocessingfunctioncorrespondingtothemessagesothatthemessageisgenerated,cancallthemessagehandler.SHELL_PostMessage()functionsfirstargumentforWin32windowhandle,thesecondparameteristhemessageIDnumber,andthethird,fourparametersaresenttothemessageprocessing functionparameters,fifth,sixparametersforthecallbackfunctionandpasstoits parameters.Win32applicationreceivesamessage,themessageisprocessed.4AsynchronousI/OModeWin32applicationfirstcallstheCreateFile()functiontoloadthe devicedriver.Beforecallingthisfunction,thepenultimatetwoparameterissettoFILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED,sayingthathecanfileoverlappedI/Ooperations.Whenthedevicedriverfileissuessfullycreated,createaninitialstateisnosignal,youneedtomanuallyresettheevent,andwillpassthiseventtypeisOVERLAPPEDdatastructure(egOverlapped).Then,OverlappedasaparameterpassedtoDeviceIoControl()function.DevicedriverputtheI/Orequestpacket(IRP)issettopendingstatus,andsetacancelroutine.IfthecurrentIRPqueueisempty,thentheIRPsenttoStartIo()routine;Otherwise,putitIRPqueue.Devicedriversafterpletingsuchwork,endingtheDeviceIoControl()processing,sodonotwaitforWin32applicationsmayIRPprocessed,fromDeviceIoControl()calltoreturn.Bydeterminingthereturnvalue,gettheIRPhandling.IfthecurrentIRPispending,thenthemainprogramdosomeotherwork,thencallWaitForSingleObject()orWaitForMultipleObject()functionwaitsfortheeventbeeOverlappedsignalstate.DevicedriversattheappropriatetimetohandlethequeuedIRP,processingisplete,callIoCompleteRequest()function.ThisfunctionOverlappedtheeventissettothesignaledstate.Win32applicationstorespondtothisincidentimmediatelyexitthewaitstate,andnosignalwillberesettothestateoftheevent,andthencallGetOverlappedResultFunctiontogettheresultoftheIRPprocess.5EventMode(WDM)Win32applicationfirstcreatesanevent,andthenpassedtotheeventhandlerdevicedrivers,thencreateasecondarythread,waitingforaneventsignaledthathewillgoonotherthings.Devicedriversaesstheeventhandle,canbeusedto convertittoaneventpointerregisterandputitupforlateruse.Whentheconditionsaremet,thedevicedriverwillsettheeventtosignaledstate,sothattheapplicationoftheworkerthreadimmediatelyknowthenews,thenmaketheappropriatetreatment.Whenthedevicedrivernolongerusesthisevent,theeventshouldbeliftedpointer.6ConclusionInthecurrentpopularWindowsoperatingsystem,devicedriversisthelowestlevelofmanipulationofhardwaresoftwareinterface.Itoffersupauserinterfaceandhardware-independent,downdirectlyI/O,hardwareinterrupts,DMAandmemoryaessandotheroperations.Itapplicationsandhardwaredetailsshields,sodonotrelyonthehardwareandsoftwareavailableinportablebetweendifferentplatforms.Thisarticledescribesthefivekindsofdevicedrivernotifiestheapplication,inwhichthefirstthreemethodsaremainlyusedinVxD,thelattertwomethodsismainlyusedforWDM.This5waystohavebeentheactualtest.Testresultsshowthattheyareabletoreachthedevicedrivernotifiestheapplicationpurposes.ReferencesAbstract: 1EuropeanYouthLi,XUJian-bo,LIFang-min,etc.virtualdevicedriverVxDinquiryanddevelopment.ComputerEngineering,xx 2(America)ChrisCant.WindowsWDMDeviceDriverDevelopmentGuide.SunYi,MaLibo,thecountryXuefei,M.,BeijingAbstract:MechanicalIndustryPress,20003LiHepingDSP-basedimagereconstructionsystemtoexploreICT,BeijingAbstract:BeijingUniversityofAeronauticsandAstronauticsMechanicalEngineeringandAutomation,xx 对于设备驱动程序通知应用程序的几种方法 在目前流行的Windows操作系统中，设备驱动程序是操纵硬件 摘要:在目前流行的Windows操作系统中，设备驱动程序是操纵硬件的最底层软件接口。为了共享在设备驱动程序设计过程中的经验，给出设备驱动程序通知应用程序的5种方法，详细说明每种方法的原理和实现过程，希望能够给设备驱动程序的设计者提供一些帮助。 摘要:在目前流行的Windows操作系统中，设备驱动程序是操纵硬件的最底层软件接口。为了共享在设备驱动程序设计过程中的经验，给出设备驱动程序通知应用程序的5种方法，详细说明每种方法的原理和实现过程，希望能够给设备驱动程序的设计者提供一些帮助。 关键词:设备驱动程序异步I/OVirtualDeviceDriver（VxD）WindowsDriverModel（WDM） 为了保证操作系统的安全性和稳定性以及应用程序的可移植性，Windows操作系统不允许应用程序直接访问系统的硬件资源，而是必须借助于相应的设备驱动程序。设备驱动程序可以直接操作硬件，如果应用程序和设备驱动程序之间实现了双向通信，也就达到了应用程序控制底层硬件设备的目的。它们之间的通信包括两个方面：一方面是应用程序传送给设备驱动程序的数据；另一方面是设备驱动程序发送给应用程序的消息。前者的实现较容易，通过CreateFile()函数获取设备驱动程序的句柄后，就可以使用Win32函数，如DeviceIoControl()、 ReadFile()或WriteFile()等实现应用程序与设备驱动程序之间的通信。后者的实现远比前者复杂，同时介绍这方面情况的文章较少。这不等于说它不重要，相反，它在有些应用场合发挥着重要的作用。设备驱动程序完成数据的采集工作后，需要马上通知应用程序，以便应用程序能够及时将数据取走并进行处理。诸如此类情况，不一而足。 鉴于设备驱动程序通知应用程序的重要性，本人结合一些经验，对它进行了总结，归纳出5种方法：异步过程调用(APC)、事件方式（VxD）、消息方式、异步I/O方式和事件方式(WDM)。下面分别说明这几种方式的原理，并给出实现的部分源代码。 1异步过程调用(APC) Win32应用程序使用CreateFile()函数动态加载设备驱动程序，然后定义一个回调函数backFunc()，并且将回调函数的地址&backFunc()作为参数，通过 DeviceIoControl()传送给设备驱动程序。设备驱动程序获得回调函数的地址后，将它保存在一个全局变量（如callback）中，同时调用Get_Cur_Thread_Handle()函数获取它的应用程序线程的句柄，并且将该句柄保存在一个全局变量（如appthread）中。当条件成熟时，设备驱动程序调用_VWIN32_QueueUserApc()函数，向Win32应用程序发送消息。这个函数带有三个参数：第一个参数为回调函数的地址（已经注册）；第二个参数为传递给回调函数的消息；第三个参数为调用者的线程句柄（已经注册）。Win32应用程序收到消息后，自动调用回调函数（实际是由设备驱动程序调用）。回调函数的输入参数是由设备驱动程序填入的，回调函数在这里主要是对消息进行处理。 2事件方式（VxD） 首先，Win32应用程序创建一个事件的句柄，称其为Ring3句柄。由于虚拟设备驱动程序使用事件的Ring0句柄，因此，需要创建Ring0句柄。用LoadLibrary()函数加载未公开的动态链接库Kernel32.dll，获得动态链接库的句柄。然后，调用GetProcAddress(),找到函数OpenVxDHandle()在动态链接库中的位置。接 着，用OpenVxDHandle()函数将Ring3事件句柄转化为Ring0事件句柄。Win32应用程序用CreateFile()函数加载设备驱动程序。如果加载成功，则调用 DeviceIoControl()函数将Ring0事件句柄传给VxD；同时，创建一个辅助线程等待信号变成有信号状态，本身则可去干其它的事情。当条件成熟时，VxD置Ring0事件为有信号状态（调用_VWIN32_SetWin32Event()函数），这马上触发对应的Ring3事件为有信号状态。一旦Ring3事件句柄为有信号状态，Win32应用程序的辅助线程就对这个消息进行相应的处理。 3消息方式 Win32应用程序调用CreateFile()函数动态加载虚拟设备驱动程序。加载成功后，通过调用DeviceIoControl()函数将窗体句柄传送给VxD，VxD利用这个句柄向窗体发消息。当条件满足时，VxD调用SHELL_PostMessage()函数向Win32应用程序发送消息。要让该函数使用成功，必须用#define定义一个消息，并且也要照样在应用程序中定义它；还要在消息循环中使用ON_MESSAGE()来定义消息对应的消息处理函数，以便消息产生时，能够调用消息处理函数。SHELL_PostMessage()函数的第一个参数为Win32窗体句柄，第二个参数为消息ID号，第三、四个参数为发送给消息处理函数的参数，第五、六个参数为回调函数和传给它的参数。Win32应用程序收到消息后，对消息进行处理。4异步I/O方式 Win32应用程序首先调用CreateFile()函数加载设备驱动程序。在调用该函数时，将倒数第2个参数设置为 FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED，表示以后可以对文件进行重叠I/O操作。当设备驱动程序文件创建成功后，创建一个初始态为无信号、需要手动复位的事件，并且将这个事件传给类型为OVERLAPPED的数据结构（如Overlapped）。然后，将Overlapped作为一个参数，传给 DeviceIoControl