page_type	description	languages	products
sample	A minifilter demonstrating the use of cancel-safe queues.	cpp	windows windows-wdk

CancelSafe File System Minifilter Driver

The CancelSafe filter is a sample minifilter that you use if you want to use cancel-safe queues.

Universal Windows Driver Compliant

This sample builds a Universal Windows Driver. It uses only APIs and DDIs that are included in OneCoreUAP.

Design and Operation

The CancelSafe minifilter initializes a cancel-safe queue when it is attached to a volume. When the minifilter is deployed, it monitors read operations that are passing through the I/O stack. If the read operation is being performed on a file named csqdemo.txt, it is queued onto the cancel-safe queue. Queued operations are completed after a brief pause through a separate worker thread that is running in system context.

For more information on file system minifilter design, start with the File System Minifilter Drivers section in the Installable File Systems Design Guide.