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WdfRequestIsReserved method

[Applies to KMDF only]

The WdfRequestIsReserved method determines whether a specified request object is one that the framework reserved to support guaranteed forward progress during low-memory situations.

Syntax


BOOLEAN WdfRequestIsReserved(
  [in]  WDFREQUEST Request
);

Parameters

Request [in]

A handle to a framework request object.

Return value

WdfRequestIsReserved returns TRUE if the specified request object is one that the framework pre-allocated for low-memory situations. Otherwise the method returns FALSE.

Remarks

For more information about the WdfRequestIsReserved method, see Guaranteeing Forward Progress of I/O Operations.

Examples

The following code example determines whether a request object that a driver's EvtIoRead callback function has received is one that the driver created for low-memory situations.


VOID
  MyIoRead (
    IN WDFQUEUE  Queue,
    IN WDFREQUEST  Request,
    IN size_t  Length
    )
  {...
  if (WdfRequestIsReserved(Request)) {
  // Low memory situation exists.
  ...
  }
  else {
  // Low memory situation does not exist.
  ...
  }

  ...}

Requirements

Minimum KMDF version

1.9

Header

Wdfrequest.h (include Wdf.h)

Library

Wdf01000.sys (see Framework Library Versioning.)

IRQL

<=DISPATCH_LEVEL

DDI compliance rules

DriverCreate

See also

WdfIoQueueAssignForwardProgressPolicy

 

 

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