Question

How do you solve the max value problem when using an integer counter, that looks like

counter = counter + 1;

When this reaches the max value, how do you know this happened? Do you add another counter for this counting how often this happened?

My question concerns about java.

Answer 1

For a fast saturated int increment (one that stops when it gets to MAX_VALUE), I guess you could write:

counters = (counter+1) + ((counter+1)>>31);

Or

counters = (counter+1) - ((counter+1)>>>31);

Or in the interests of fun, for AtomicInteger, I think:

private final AtomicInteger counter = new AtomicInteger(0);

public void increment() {
    int count;
    do {
        count = counter.get();
        if (count == Integer.MAX_VALUE) {
            return;
        }
    } while (!counter.compareAndSet(count, count+1));
}