Manage mult$-$unit resources

a$)$ Extend the request and release functions to work with resources having multiple identical units.

$$ p$.$other$\_$resources is a list of pairs $($r$,$ k$)$ where r is a resource and k is the number of units that p is holding.

$$ r$.$state is a counter that keeps track of the currently available units of r$.$

$$ r$.$waiting$\_$list contains pairs $($p$,$ k$)$ where p is the waiting process and k is the number of requested units.

$$ The request functions has the form request$($r$,$ k$)$ where r is the resource and k is the number of units. To simplify the algorithm, a process may request units of the same resource only once.

$$ The release functions has the form release$($r$)$ where r is the resource. All k units of r are released at the same time.

$$ Note that a release of k units may enable more than one process from r$.$waiting$\_$list.

b$)$ A process could remain stuck in r$.$waiting$\_$list forever if the number of units requested exceeds the total number of units available initially in r$.$ How could that problem be prevented?

c$)$ Problem Nine: A process p could starve by being skipped over by processes arriving after p but requesting smaller numbers of units than p$.$ How could that problem be prevented?