WdfRequestIsReserved - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
// wdfrequest.h

BOOLEAN WdfRequestIsReserved(
  [in] WDFREQUEST Request
);
View the official Windows Driver Kit DDI reference

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Windows Driver Kit DDI reference (nf-wdfrequest-wdfrequestisreserved)

WdfRequestIsReserved function

Description

[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.

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.
  ...
  }

  ...}

See also

WdfIoQueueAssignForwardProgressPolicy