ProvaTeorica 2014.02.22

Testo: [1]

Esercizio c.1

monitor bbwl {
	condition oktowrite;
	condition oktolog;
	condition oktoread;
	int logging = 0;
	queue q;
	
	procedure entry write (eltype elem) {
	if (q.length() == MAXELEM || logging)
			oktowrite.wait();
	q.enqueue (elem);
	logging = 1;
	oktolog.signal();
	}
	
	procedure entry eltype log() {
	if (q.length == 0)
		oktolog.wait();
	eltype tmp = q.top();
	logging = 0;
	oktoread.signal();
	return tmp;
	}

	procedure entry eltype read() {
	if (q.length == 0 || logging)
		oktoread.wait();
	eltype tmp = q.dequeue();
	oktowrite.signal();
	return tmp;
	}
}