Im not even sure where to begin with this as my instructor hasn't even gone over it, so any help is appreciated. Hope you can see it alright, I had some issues with scanning the page

Consider a sharable resource with the following characteristics: (1) As long as there are fewer than three processes using the resource, new processes can start using it right away. (2) Once there are three process using the resource, all three must leave before any new processes can begin using it. We realize that counters are needed to keep track of how many processes are waiting and active, and that these counters are themselves 5.1