When a parent runnable is canceled, the cancellation request uses the nested runnable information to recursively propagate the request down to the innermost nested runnable. In the present version of the Threading package, cancellation is the only operation that propagates in this manner.

The nesting information can also be used to determine the current enclosing runnable for any thread that originated from a threaded runnable. Although it is possible to do this yourself by using the rwThread() and getNestedRunnable() functions, you can also use the Threading package function rwRunnable(). As was the case with the handle returned by rwThread(), the handle returned from rwRunnable() is empty if the current thread was not created by a Threading package runnable class.