IQueueCallbackStateChange::OnStateChange method (wudfddi.h)

Article
02/22/2024

[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 OnStateChange method is called when the state of the I/O queue object changes.

Syntax

void OnStateChange(
  [in] IWDFIoQueue        *pWdfQueue,
  [in] WDF_IO_QUEUE_STATE QueueState
);

Parameters

[in] pWdfQueue

A pointer to the IWDFIoQueue interface for the I/O queue object whose state changes.

[in] QueueState

A valid bitwise OR of WDF_IO_QUEUE_STATE-typed values that indicates status for the queue.

Return value

None

Remarks

A driver registers the IQueueCallbackStateChange interface when the driver calls the IWDFDevice::CreateIoQueue method to create an I/O queue or to configure the default I/O queue. The driver can optionally register the IQueueCallbackStateChange interface only for a manual queue. The driver must not register IQueueCallbackStateChange for a sequential or a parallel queue.

Requirements

Requirement	Value
Target Platform	Windows
Header	wudfddi.h (include Wudfddi.h)