p() {
	wait(s);
	if(count >= 0) {
		signal(s);
	}
	else {
		queue.add(pid);
		signal(s);
		block(pid);
	}
}

v() {
	wait(s);
	if(count >= 0) {
		signal(s);
	}
	else {
		pid = queue.push();
		signal(s);
		unblock(pid);
	}
}