The idea is based on the Mark-Copy (MC) algorithm. The heap is divided up into a number of equally sized windows, say 40. One of these is the nursery, and the others act as tenured space. (I don't know why, but the papers about this seem to use a two-generation rather than three-generation model. I think it could easily be updated to use three generations, but I'll stick with this for now.) Each window has a logical number, with the nursery having the highest number.
