public void adjustTellerNumber() {
// This is actually a control system. By adjusting
// the numbers, you can reveal stability issues in
// the control mechanism.
// If line is too long, add another teller:
if (customers.size() / workingTellers.size() > 2) {
// If tellers are on break or doing
// another job, bring one back:
if (tellersDoingOtherThings.size() > 0) {
Teller teller = tellersDoingOtherThings.remove();
teller.serveCustomerLine();
workingTellers.offer(teller);
return;
}
// Else create (hire) a new teller
Teller teller = new Teller(customers);
exec.execute(teller);
workingTellers.add(teller);
return;
}
// If line is short enough, remove a teller:
if (workingTellers.size() > 1 && customers.size() / workingTellers.size() < 2)
reassignOneTeller();
// If there is no line, we only need one teller:
if (customers.size() == 0) while (workingTellers.size() > 1) reassignOneTeller();
}
public TellerManager(ExecutorService e, CustomerLine customers, int adjustmentPeriod) {
exec = e;
this.customers = customers;
this.adjustmentPeriod = adjustmentPeriod;
// Start with a single teller:
Teller teller = new Teller(customers);
exec.execute(teller);
workingTellers.add(teller);
}