It works like your first guess, but it's not so bad. Downstream code has to either check the token occasionally, subscribe to an event from it, or just pass it

It works like your first guess, but it's not so bad. Downstream code has to either check the token occasionally, subscribe to an event from it, or just pass it forward to another function which uses the token. So if you were writing a function that just made a series of network requests, you would make it take a CancellationToken as a parameter, and then you would pass that parameter on to each of the network request function calls inside your function. Then if the token is in the aborted state while any of the network function calls are in-progress, then that network function call will throw an exception which will bubble up through your function, without your function needing to do anything special with the CancellationToken directly.