RoundRobin

public int index() {
	return Math.abs(idx.getAndIncrement() % executors.length);
}

public int index1() {
	return idx1.getAndIncrement() & executors1.length - 1;
}

public int index2() {
	int value = idx1.getAndIncrement();
	int i = value & executors1.length - 1;
	if (value % 2 != 0) {
		i++;
	}
	if (i >= executors1.length) {
		return index2();
	}
	return i;
}