Edit

WDF_IO_QUEUE_STATE enumeration (wudfddi_types.h)

  • Article

[Warning: UMDF 2 is the latest version of UMDF and supersedes UMDF 1. All new UMDF drivers should be written using UMDF 2. No new features are being added to UMDF 1 and there is limited support for UMDF 1 on newer versions of Windows 10. Universal Windows drivers must use UMDF 2. For more info, see Getting Started with UMDF.]

The WDF_IO_QUEUE_STATE enumeration contains values that identify the state of an I/O queue.

Syntax

typedef enum _WDF_IO_QUEUE_STATE {
  WdfIoQueueAcceptRequests,
  WdfIoQueueDispatchRequests,
  WdfIoQueueNoRequests,
  WdfIoQueueDriverNoRequests,
  WdfIoQueuePnpHeld
} WDF_IO_QUEUE_STATE, *PWDF_IO_QUEUE_STATE;

Constants

 
WdfIoQueueAcceptRequests
If this value is set to 1, the queue accepts requests by automatically forwarding them through the setting of the IWDFIoQueue::ConfigureRequestDispatching method or by manually forwarding each request through a call to the IWDFIoRequest::ForwardToIoQueue method.

If this value is set to 0, the queue completes any automatically forwarded requests with "status canceled" or fails IWDFIoRequest::ForwardToIoQueue with "status busy".
WdfIoQueueDispatchRequests
If this value is set to 1, the queue automatically presents requests to the driver, unless the queue is a WdfIoQueueDispatchManual type (see WDF_IO_QUEUE_DISPATCH_TYPE).

If this value is set to 0, the queue does not automatically dispatch requests to the driver. The setting of this status does not prevent the driver from calling the IWDFIoQueue::RetrieveNextRequest method to manually retrieve a request from the queue.
WdfIoQueueNoRequests
If this value is set to 1, no requests are in the queue, even requests that can be presented to the driver and that can be returned from IWDFIoQueue::RetrieveNextRequest.
WdfIoQueueDriverNoRequests
If this value is set to 1, there are no requests that the driver currently operates on that it received from the queue.
WdfIoQueuePnpHeld
If this value is set to 1, an event from the Plug and Play (PnP) subsystem suspended the queue from processing requests.

Requirements

Requirement Value
Header wudfddi_types.h (include Wudfddi_types.h)

See also

IWDFIoQueue::ConfigureRequestDispatching

IWDFIoQueue::RetrieveNextRequest

IWDFIoRequest::ForwardToIoQueue

WDF_IO_QUEUE_DISPATCH_TYPE