WdfIoQueueRetrieveNextRequest - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// wdfio.h
NTSTATUS WdfIoQueueRetrieveNextRequest(
[in] WDFQUEUE Queue,
[out] WDFREQUEST *OutRequest
);
View the official Windows Driver Kit DDI referenceNo description available.
[Applies to KMDF and UMDF]
The WdfIoQueueRetrieveNextRequest method retrieves the next available I/O request from a specified I/O queue.
Queue [in]A handle to a framework queue object.
OutRequest [out]A pointer to a location that receives a handle to a framework request object. If the queue is empty or the last request has been retrieved, this parameter receives NULL.
WdfIoQueueRetrieveNextRequest returns STATUS_SUCCESS if the operation succeeds. Otherwise, this method might return one of the following values:
| Return code | Description |
|---|---|
| STATUS_INVALID_PARAMETER | The driver supplied an invalid handle. |
| STATUS_NO_MORE_ENTRIES | The framework reached the end of the I/O queue. |
| STATUS_INVALID_DEVICE_STATE | The specified I/O queue is configured for the parallel dispatching method. |
| STATUS_WDF_PAUSED | The specified I/O queue is power-managed and its device is in a low-power state, or the specified queue is stopped. |
This method also might return other NTSTATUS values.
A bug check occurs if the driver supplies an invalid object handle.
If a driver configures an I/O queue for manual dispatching of I/O requests, the driver typically calls WdfIoQueueRetrieveNextRequest to obtain requests from the queue. A driver that has configured an I/O queue for sequential dispatching might also call WdfIoQueueRetrieveNextRequest. For more information about using WdfIoQueueRetrieveNextRequest with the manual or sequential dispatching methods, see Dispatching Methods for I/O Requests.
After calling WdfIoQueueRetrieveNextRequest to obtain an I/O request, the driver owns the request and must process the I/O request in some manner.
For more information about the WdfIoQueueRetrieveNextRequest method, see Managing I/O Queues.
The following code example obtains a handle to the next request object that is contained in a device's I/O queue.
NTSTATUS status;
WDFREQUEST request;
status = WdfIoQueueRetrieveNextRequest(
pDeviceContext->ReadQueue,
&request
);
WdfIoQueueRetrieveFoundRequest
WdfIoQueueRetrieveRequestByFileObject