操作系统系统调用数据结构.docx

操作系统系统调用数据结构.docx

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操作系统系统调用数据结构

OSVERSIONINFOEX

[Thisispreliminarydocumentationandsubjecttochange.]

TheOSVERSIONINFOEXstructurecontainsoperatingsystemversioninformation.Theinformationincludesmajorandminorversionnumbers,abuildnumber,aplatformidentifier,andinformationaboutthelatestServicePackinstalledonthesystem.ThisstructureisusedwiththeGetVersionExfunction.OSVERSIONINFOEXisanextendedversionoftheOSVERSIONINFOstructure.

typedefstruct_OSVERSIONINFOEXA{

DWORDdwOSVersionInfoSize;

DWORDdwMajorVersion;

DWORDdwMinorVersion;

DWORDdwBuildNumber;

DWORDdwPlatformId;

TCHARszCSDVersion[128];

WORDwServicePackMajor;

WORDwServicePackMinor;

WORDwReserved[2];

}OSVERSIONINFOEXA,*POSVERSIONINFOEXA,*LPOSVERSIONINFOEXA;

Members

dwOSVersionInfoSize

Specifiesthesize,inbytes,ofthisdatastructure.Setthismembertosizeof（OSVERSIONINFOEX）beforecallingtheGetVersionExfunction.

dwMajorVersion

Identifiesthemajorversionnumberoftheoperatingsystem.Forexample,forWindowsNTversion5.0,themajorversionnumberis5.

dwMinorVersion

Identifiestheminorversionnumberoftheoperatingsystem.Forexample,forWindowsNTversion5.0,theminorversionnumberis0.

dwBuildNumber

Identifiesthebuildnumberoftheoperatingsystem.

dwPlatformId

Identifiestheoperatingsystemplatform.Thismembercanbeoneofthefollowingvalues.

Value

Platform

VER_PLATFORM_WIN32s

Win32sonWindows3.1.

VER_PLATFORM_WIN32_WINDOWS

Win32onWindows95orWindows98.

VER_PLATFORM_WIN32_NT

Win32onWindowsNT.

szCSDVersion

Containsanull-terminatedstring,suchas"ServicePack3",thatindicatesthelatestServicePackinstalledonthesystem.IfnoServicePackhasbeeninstalled,thestringisempty.

wServicePackMajor

IdentifiesthemajorversionnumberofthelatestServicePackinstalledonthesystem.IfnoServicePackhasbeeninstalled,thevalueiszero.

wServicePackMinor

IdentifiestheminorversionnumberofthelatestServicePackinstalledonthesystem.IfnoServicePackhasbeeninstalled,thevalueiszero.

wReserved

Reservedforfutureuse.

QuickInfo

  WindowsNT:

Requiresversion5.0orlater.

  Windows:

Unsupported.

  WindowsCE:

Unsupported.

  Header:

Declaredinwinbase.h.

  Unicode:

DefinedasUnicodeandANSIstructures.

GetProcessVersion

TheGetProcessVersionfunctionobtainsthemajorandminorversionnumbersofthesystemonwhichaspecifiedprocessexpectstorun.

DWORDGetProcessVersion（

DWORDProcessId//identifierspecifyingtheprocessofinterest

）;

Parameters

ProcessId

Processidentifierthatspecifiestheprocessofinterest.AProcessIdvalueofzerospecifiesthecallingprocess.

ReturnValues

Ifthefunctionsucceeds,thereturnvalueistheversionofthesystemonwhichtheprocessexpectstorun.Thehighwordofthereturnvaluecontainsthemajorversionnumber.Thelowwordofthereturnvaluecontainstheminorversionnumber.

Ifthefunctionfails,thereturnvalueiszero.Togetextendederrorinformation,callGetLastError.ThefunctionfailsifProcessIdisaninvalidvalue.

Remarks

TheGetProcessVersionfunctionperformslessquicklywhenProcessIdisnonzero,specifyingaprocessotherthanthecallingprocess.

Theversionnumberreturnedbythisfunctionistheversionnumberstampedintheimageheaderofthe.EXEfiletheprocessisrunning.Linkerprogramssetthisvalue.

QuickInfo

  WindowsNT:

Requiresversion3.51orlater.

  Windows:

RequiresWindows95orlater.

  WindowsCE:

Unsupported.

  Header:

Declaredinwinbase.h.

  ImportLibrary:

Usekernel32.lib.

GetVersionEx

TheGetVersionExfunctionobtainsextendedinformationabouttheversionoftheoperatingsystemthatiscurrentlyrunning.

BOOLGetVersionEx（

LPOSVERSIONINFOlpVersionInformation//pointertoversion

//informationstructure

）;

Parameters

lpVersionInformation

PointertoanOSVERSIONINFOdatastructurethatthefunctionfillswithoperatingsystemversioninformation.

BeforecallingtheGetVersionExfunction,setthedwOSVersionInfoSizememberoftheOSVERSIONINFOdatastructuretosizeof（OSVERSIONINFO）.

WindowsNT5.0andlater:

ThismembercanbeapointertoanOSVERSIONINFOEXstructure.SetthedwOSVersionInfoSizemembertosizeof（OSVERSIONINFOEX）toidentifythetypeofstructure.

ReturnValues

Ifthefunctionsucceeds,thereturnvalueisnonzero.

Ifthefunctionfails,thereturnvalueiszero.Togetextendederrorinformation,call

GetLastError.ThefunctionfailsifyouspecifyaninvalidvalueforthedwOSVersionInfoSizememberoftheOSVERSIONINFOorOSVERSIONINFOEXstructure.

Remarks

WhenusingtheGetVersionExfunctiontodeterminewhetheryourapplicationisrunningonaparticularversionoftheoperatingsystem,checkforversionnumbersthataregreaterthanorequaltothedesiredversionnumbers.Thisensuresthatthetestsucceedsforlaterversionsoftheoperatingsystem.Forexample,ifyourapplicationrequiresWindows98,usethefollowingtest:

GetVersionEx（&osvi）;

bIsWindows98orLater=

（osvi.dwPlatformId==VER_PLATFORM_WIN32_WINDOWS）&&

（（osvi.dwMajorVersion>4）||

（（osvi.dwMajorVersion==4）&&（osvi.dwMinorVersion>0）））;

Identifyingthecurrentoperatingsystemisusuallynotthebestwaytodeterminewhetheraparticularoperatingsystemfeatureispresent.ThisisbecausetheoperatingsystemmayhavehadnewfeaturesaddedinaredistributableDLL.RatherthanusingGetVersionExtodeterminetheoperatingsystemplatformorversionnumber,testforthepresenceofthefeatureitself.

Todeterminethebestwaytotestforafeature,refertothedocumentationforthefeatureofinterest.Thefollowinglistdiscussessomecommontechniquesforfeaturedetection:

∙Youcantestforthepresenceofthefunctionsassociatedwithafeature.TotestforthepresenceofafunctioninasystemDLL,callthe

LoadLibraryfunctiontoloadtheDLL.Thencallthe

GetProcAddressfunctiontodeterminewhetherthefunctionofinterestispresentintheDLL.UsethepointerreturnedbyGetProcAddresstocallthefunction.Notethatevenifthefunctionispresent,itmaybeastubthatjustreturnsanerrorcodesuchasERROR_CALL_NOT_IMPLEMENTED.

∙YoucandeterminethepresenceofsomefeaturesbyusingtheGetSystemMetricsfunction.Forexample,youcandetectmultipledisplaymonitorsbycallingGetSystemMetrics（SM_CMONITORS）.

∙ThereareseveralversionsoftheredistributableDLLsthatimplementshellandcommoncontrolfeatures.Forinformationaboutdeterminingwhichversionsarepresentonthesystemyourapplicationisrunningon,seethetopic

ShellVersions.

WindowsCE:

ThevalueofthedwPlatformIDmemberoftheOSVERSIONINFOstructurewillbeVER_PLATFORM_WIN32_CE.

QuickInfo

  WindowsNT:

Requiresversion3.5orlater.

  Windows:

RequiresWindows95orlater.

  WindowsCE:

Requiresversion1.0orlater.

  Header:

Declaredinwinbase.h.

  ImportLibrary:

Usekernel32.lib.

  Unicode:

ImplementedasUnicodeandANSIversionsonWindowsNT.

GetPriorityClass

TheGetPriorityClassfunctionreturnsthepriorityclassforthespecifiedprocess.Thisvalue,togetherwiththepriorityvalueofeachthreadoftheprocess,determineseachthread'sbaseprioritylevel.

DWORDGetPriorityClass（

HANDLEhProcess//handletotheprocess

）;

Parameters

hProcess

Handletotheprocess.

WindowsNT:

ThehandlemusthavePROCESS_QUERY_INFORMATIONaccess.

ReturnValues

Ifthefunctionsucceeds,thereturnvalueisthepriorityclassofthespecifiedprocess.

Ifthefunctionfails,thereturnvalueiszero.Togetextendederrorinformation,callGetLastError.

Theprocess'spriorityclassisoneofthefollowingvalues:

Priority

Meaning

HIGH_PRIORITY_CLASS

Indicatesaprocessthatperformstime-criticaltasksthatmustbeexecutedimmediatelyforittoruncorrectly.Thethreadsofahigh-priorityclassprocesspreemptthethreadsofnormaloridlepriorityclassprocesses.AnexampleistheTaskList,whichmustrespondquicklywhencalledbytheuser,regardlessoftheloadontheoperatingsystem.Useextremecarewhenusingthehigh-priorityclass,becauseahigh-priorityclassCPU-boundapplicationcanusenearlyallavailablecycles.

IDLE_PRIORITY_CLASS

Indicatesaprocesswhosethreadsrunonlywhenthesystemisidleandarepreemptedbythethreadsofanyprocessrunninginahigherpriorityclass.Anexampleisascreensaver.Theidlepriorityclassisinheritedbychildprocesses.

NORMAL_PRIORITY_CLASS

Indicatesanormalprocesswithnospecialschedulingneeds.

REALTIME_PRIORITY_CLASS

Indicatesaprocessthathasthehighestpossiblepriority.Thethreadsofareal-timepriorityclassprocesspreemptthethreadsofallotherprocesses,includingoperatingsystemprocessesperformingimportanttasks.Forexample,areal-timeprocessthatexecutesformorethanaverybriefintervalcancausediskcachesnottoflushorcausethemousetobeunresponsive.

Remarks

Everythreadhasabasepriorityleveldeterminedbythethread'spriorityvalueandthepriorityclassofitsprocess.TheoperatingsystemusesthebaseprioritylevelofallexecutablethreadstodeterminewhichthreadgetsthenextsliceofCPUtime.Threadsarescheduledinaround-robinfashionateachprioritylevel,andonlywhentherearenoexecutablethreadsatahigherlevelwillschedulingofthreadsatalowerleveltakeplace.

Foratablethatshowsthebaseprioritylevelsforeachcombinationofpriorityclassandthreadpriorityvalue,seetheSetPriorityClassfunction.

QuickInfo

  WindowsNT:

Requiresversion3.1orlater.

  Windows:

RequiresWindows95orlater.

  WindowsCE:

Unsupported.

  Header:

Declaredinwinbase.h.

  ImportLibrar