nf-wdfrequest-wdfrequestisfrom32bitprocess.md

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NF:wdfrequest.WdfRequestIsFrom32BitProcess	WdfRequestIsFrom32BitProcess function (wdfrequest.h)	The WdfRequestIsFrom32BitProcess method checks whether the originator of a specified I/O request is a 32-bit user-mode application.	wdf\wdfrequestisfrom32bitprocess.htm	wdf	02/26/2018	WdfRequestIsFrom32BitProcess function	DFRequestObjectRef_d700883f-10dc-428b-abbf-7d257d2bd62d.xml, WdfRequestIsFrom32BitProcess, WdfRequestIsFrom32BitProcess method, kmdf.wdfrequestisfrom32bitprocess, wdf.wdfrequestisfrom32bitprocess, wdfrequest/WdfRequestIsFrom32BitProcess	wdfrequest.h	Wdf.h	Universal			1.0	2.0	DriverCreate, InvalidReqAccess, InvalidReqAccessLocal, KmdfIrql, KmdfIrql2							Wdf01000.sys (KMDF); WUDFx02000.dll (UMDF)		<=DISPATCH_LEVEL	Windows		WdfRequestIsFrom32BitProcess wdfrequest/WdfRequestIsFrom32BitProcess	APIRef kbSyntax	LibDef	Wdf01000.sys Wdf01000.sys.dll WUDFx02000.dll WUDFx02000.dll.dll	WdfRequestIsFrom32BitProcess

WdfRequestIsFrom32BitProcess function

-description

[Applies to KMDF and UMDF]

The WdfRequestIsFrom32BitProcess method checks whether the originator of a specified I/O request is a 32-bit user-mode application.

-parameters

-param Request [in]

A handle to a framework request object.

-returns

On 64-bit systems,WdfRequestIsFrom32BitProcess returns TRUE if the originator of the current I/O request is a 32-bit user-mode process, and FALSE otherwise. On 32-bit systems, WdfRequestIsFrom32BitProcess always returns TRUE.

A bug check occurs if the driver supplies an invalid object handle.

-remarks

Drivers can call WdfRequestIsFrom32BitProcess to determine whether an I/O request is likely to contain data elements that need to be converted, or "thunked," before they can be used in a 64-bit driver.

The specified request handle must have been obtained from one of the driver's I/O queues and not from a call to WdfRequestCreate.

Examples

The following code example determines if an I/O request came from a 32-bit application.

VOID
MyEvtIoRead(
    IN WDFQUEUE  Queue,
    IN WDFREQUEST  Request,
    IN size_t  Length
    )
{
...
    if (WdfRequestIsFrom32BitProcess(Request)) {
        //
        // The driver is running on a 64-bit computer and the 
        // I/O request came from a 32-bit application.
        //
...
    }
...
}

-see-also

WdfRequestCreate