IWDFIoRequest2::IsCanceled method (wudfddi.h)

[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 IsCanceled method determines whether the I/O manager has attempted to cancel an I/O request.

Syntax

BOOL IsCanceled();

Return value

IsCanceled returns TRUE if the I/O manager has attempted to cancel the I/O request. This method returns FALSE for any of the following reasons:

• The I/O manager has not attempted to cancel the request.
• The calling driver does not own the request.
• The calling driver has called the IWDFIoRequest::MarkCancelable method.

Remarks

If your driver has not called IWDFIoRequest::MarkCancelable to register an IRequestCallbackCancel::OnCancel callback function, but if you want your driver to determine if the I/O manager has attempted to cancel an I/O request, the driver can call IsCanceled.

A driver can call IsCanceled for a request only if the driver owns the I/O request. If the driver has called IWDFIoRequest::MarkCancelable, it must call IWDFIoRequest::UnmarkCancelable before calling IsCanceled.

If IsCanceled returns TRUE, your driver should cancel the request by calling IWDFIoRequest::Complete with the CompletionStatus parameter set to HRESULT_FROM_WIN32(ERROR_OPERATION_ABORTED).

For more information about IsCanceled, see Canceling I/O Requests.

Examples

In the following code example, if IsCanceled returns TRUE, the driver completes the I/O request by calling IWDFIoRequest::Complete with a completion status of HRESULT_FROM_WIN32(ERROR_OPERATION_ABORTED).

if (fxRequest2->IsCanceled())
{
    fxRequest2->Complete(HRESULT_FROM_WIN32(ERROR_OPERATION_ABORTED));
}
...

Requirements

See also

IRequestCallbackCancel::OnCancel

IWDFIoRequest2

IWDFIoRequest::MarkCancelable

IWDFIoRequest::UnmarkCancelable