Breaking out of Sub Flows

I'm looking at a process where a number of activities happen in parallel, some of these can trigger an action where the process going on in a Sub Flow should be abandoned and the token moved through the process.
Is it possible to simply move a token out of a sub flow or cancel the process?
My current thought is to add a number of decision points and check a label on the parent token at a number of steps (though this would be a bit messy and delay the action in a number of situations)

Mike

You can use the releasetoken() command to release a token from its current activity to an activity you designate. Question is how to get access to the token. If it's a child token, you can use getchildtoken().

In the next release will be added three activities that make preemption in process flow much easier.