code: private int getNextIndex() {
  		for (;;) {
              int current = index.get();
              int next = (current == balancers.size() ? 1 : current + 1);
              if (index.compareAndSet(current, next))
                  return next-1;
          }
  	}
docs: Computes the index of the next balancer to retrieve. Adaptation of the {@link AtomicInteger} incrementAndGet() code.
  
  @return