[Applies to KMDF and UMDF]
The WdfIoQueueRetrieveRequestByFileObject method retrieves the next available I/O request, from a specified I/O queue, that is associated with a specified file object.
NTSTATUS WdfIoQueueRetrieveRequestByFileObject( WDFQUEUE Queue, WDFFILEOBJECT FileObject, WDFREQUEST *OutRequest );
A handle to a framework queue object.
A handle to a framework file object.
A pointer to a location that receives a handle to a framework request object. If WdfIoQueueRetrieveRequestByFileObject does not return STATUS_SUCCESS, it does not set the location's value.
WdfIoQueueRetrieveRequestByFileObject returns STATUS_SUCCESS if the operation succeeds. Otherwise, this method might return one of the following values:
||The driver supplied an invalid handle.|
||The framework reached the end of the I/O queue.|
||The specified I/O queue is configured for the parallel dispatching method.|
||The specified I/O queue is power-managed and its device is in a low-power state.|
This method also might return other NTSTATUS values.
A bug check occurs if the driver supplies an invalid object handle.
A driver that has configured an I/O queue for manual or sequential dispatching might call WdfIoQueueRetrieveRequestByFileObject. For more information about using WdfIoQueueRetrieveRequestByFileObject with the manual or sequential dispatching methods, see Dispatching Methods for I/O Requests.
For more information about the WdfIoQueueRetrieveRequestByFileObject method, see Managing I/O Queues.
The following code example obtains, from a specified I/O queue, a handle to the next framework request object that is associated with a specified framework file object.
WDFREQUEST request; status = WdfIoQueueRetrieveRequestByFileObject( queue, fileObject, &request );
|Minimum KMDF version||1.0|
|Minimum UMDF version||2.0|
|Header||wdfio.h (include Wdf.h)|
|Library||Wdf01000.sys (KMDF); WUDFx02000.dll (UMDF)|
|DDI compliance rules||DoubleCompletion, DriverCreate, KmdfIrql, KmdfIrql2|