// (1) Restroom Access
int numMen = 0;
int numWomen = 0;

cv waitingMen;
cv waitingWomen;

mutex L;

// solve starvation by preventing women/men entering
// once a woman/man has left

// changes to man/woman procedures done only for women
enum turn = MEN;
int numWaitingMen;
int numWaitingWomen;

class Bathroom {
public:
	static void UseBathroom();
};

void man_wants_to_enter() {
	L.lock();
	while(numWomen > 0) {
		waitingMen.wait(L);
	}
	numMen++;
	L.unlock();
}

void man_leaves{
	L.lock();
	numMen--;
	if (numMen == 0)
		waitingWomen.broadcast();
	L.unlock();
}

void woman_wants_to_enter() {
	L.lock();
	numWaitingWomen++
	while(numMen > 0 || turn == MEN) {
		waitingWomen.wait(L);
	}
	numWaitingWomen--;
	numWomen++;
	L.unlock();
}

void woman_leaves() {
	L.lock();
	numWomen--;

	if (numWaitingMen > 0 && turn == WOMEN)
		turn = MEN;

	if (numWomen == 0)
		waitingWomen.broadcast();
	L.unlock();
}

// (2) Locks:
// Need m locks. But this often isn't optimal, since
// there is an overhead to locks.

// (3) FileAccess
// exactly what you would think --
// keep track of the sum of the priorities
// of the threads reading the file, and broadcast
// at the end.

// (4) Barrier
// HW: write this out.