Real life practice in lottery scheduling

I currently have a course covering operating systems at university. We learn in this course several scheduling algorithms. An operating system needs these kind of algorithms to determine which process to run at which time to allow these process to be executed „simultaniously“ (from the users view).

Good scheduling algorithms have normally some very nice features:

  • They avoid the starving of one process (that one process can’t run at all and therefore makes no progress).
  • That all processes run the approriate percentage (defined by it’s priority) of time in each bigger time interval.

But they are maybe not only useful for operating systems but also for people like me. Probably they could help me to improve the scheduling of my learning.

An algorithm that seems to be suited best for this purpose is called lottery scheduling (pdf). It’s an algorithm that gives a each process some lottery tickets (their number resembles the priority of the process). Every time the algorithm has to choose a new process to run, it simply picks a lottery ticket randomly and returns the process that owns the ticket. A useful addition is (in scenarios with only a few tickets) to remove the tickets that are picked temporarily from the lottery pot and put them back again, when the pot is empty.

But how could I use this algorithm in practice?

I take a stack of blanko cards, each card worth around 2 hours of learning time, and assign them to each of my courses. E.g. the course operating systems gets 3 cards, out of the 25 cards that now make up my week.

Now, when I’ve time to learn, I pick a card out of the shuffeled card stack which then tells me to learn about 2 hours e.g. for my theoretical computer science course.

This „practical exercise“ in operating systems will hopefully boost my learning – and of course is funny way to learn, as I never know what I’m going to learn. Later, I probably also could use it to ensure that I’m blogging more regularly here and progress with my compiler project.