I highly recommend looking into the KeyKOS operating system, which allows time and space resource usage to be controlled via a common abstraction of authority (

I highly recommend looking into the KeyKOS operating system, which allows time and space resource usage to be controlled via a common abstraction of authority (keys/capabilities) - and that recursively. The lectures of their Advanced Operating Systems course are great! https://www.cse.unsw.edu.au/~cs9242/18/lectures/ https://www.cse.unsw.edu.au/~cs9242/18/lectures/