Hi Yvan,

I don't know if there is any out-of-the-box way of doing what you are trying to achieve, however, it should be possible to apply similar concepts to what is used in multithreaded scenarios.

One approach you could do is to use the queued option in the QAction definition (Docs Ref), which is actually also useful so you do not have an RTE from a QAction running for too long (the several hours you mention).

With the queued option the QAction will run in the background allowing you to continue executing other operations and you can take advantage of this fact to trigger it to start an operation and also to stop the operation even before the first execution has finished.

Since each time you trigger the QAction it will run in a separate thread, you will have to be careful to implement the proper locking to ensure data correctness and also make sure you take the necessary precautions to not keep the thread running even after the element has been stopped or even deleted.

But with these safeties in place, you can add a global variable within the scope of the QAction class (do not forget to remove the static option from the Run method) which would then implement a mechanism similar to a CancellationToken from C#.

When clicking the button to Run, you would set the variable to "Run" and check every so often if it is still with the same value and proceed with another chuck of work.

When clicking the button to Cancel, you would set the variable to "Cancel" and exit.