WdfRequestGetEffectiveIoType function (wdfrequest.h)

[Applies to UMDF only]

The WdfRequestGetEffectiveIoType method returns the buffer access method that UMDF is using for the data buffers of the specified I/O request.

Syntax

WDF_DEVICE_IO_TYPE WdfRequestGetEffectiveIoType(
  [in] WDFREQUEST Request
);

Parameters

[in] Request

A handle to a framework request object.

Return value

WdfRequestGetEffectiveIoType returns a WDF_DEVICE_IO_TYPE-typed value that identifies the buffer access method that UMDF is using for the I/O request's data buffers.

Remarks

For more information, see Managing Buffer Access Methods in UMDF Drivers.

Examples

The following code example shows how an EvtIoWrite callback function can determine the buffer access method for the specified write request.

VOID
MyDrvEvtIoWrite(
  _In_  WDFQUEUE Queue,
  _In_  WDFREQUEST Request,
  _In_  size_t Length
)
{ 

...

    WDF_DEVICE_IO_TYPE iotype = WdfDeviceIoUndefined;
    
    iotype = WdfRequestGetEffectiveIoType(Request);

...

}

Requirements

See also

WDF_DEVICE_IO_TYPE