I am new to learning about concurrency and I am working on an app that uses the HandTrackingProvider class. In the Happy Beam sample code, there is a HearGestureModel which has a reference to the HandTrackingProvider() and this seems to write to a struct called HandUpdates inside the HeartGestureModel class through the publishHandTrackingUpdates() function. On another thread, there is a function called computeTransformofUserPerformedHeartGesture() which reads the values of the HandUpdates to determine whether the user is making the appropriate gesture. My question is, how is the code handling the constant read and write to the HandUpdates struct?

When I first install and run the app, it requests authorization for hand tracking data. But then if I go to the settings and disable hand tracking from the app, it no longer requests. The output of requestAuthorization(for:) method just says [handTracking : denied] Any idea why the push request only shows up once then never again?