IWDFIoQueue::Stop method (wudfddi.h)

Article
10/21/2021

[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 Stop method prevents an I/O queue from delivering I/O requests, but the queue receives and stores new requests.

Syntax

void Stop(
  [in, optional] IQueueCallbackStateChange *pStopComplete
);

Parameters

[in, optional] pStopComplete

A pointer to the IQueueCallbackStateChange interface whose method the framework calls after all outstanding I/O requests, if any, in the driver are completed. This parameter is optional and can be NULL.

Return value

None

Remarks

A call to Stop is asynchronous and immediately returns to the driver. The driver is notified through the method of the supplied IQueueCallbackStateChange interface after all outstanding requests in the driver complete.

The driver should ensure that only one of the following methods is in progress at any given time:

IWDFIoQueue::Stop
IWDFIoQueue::Drain
IWDFIoQueue::Purge

For example, if the driver previously called Stop, it should wait for notification from the method of the interface that the pStopComplete parameter points to before the driver calls either Drain or Purge. Violating this rule results in termination of the host process.

The Stop method enables the queue to receive new requests, even if the queue was not receiving new requests before the driver called Stop. For example, a driver might call IWDFIoQueue::Drain, which causes the framework to stop adding new I/O requests to the queue. The driver's subsequent call of Stop causes the framework to resume adding requests to the queue.

Requirements

Requirement	Value
End of support	Unavailable in UMDF 2.0 and later.
Target Platform	Desktop
Minimum UMDF version	1.5
Header	wudfddi.h (include Wudfddi.h)
DLL	WUDFx.dll