public void setUpper(int i) {
while (true) {
IntPair oldv = values.get();
if (i < oldv.lower)
throw new IllegalArgumentException("Can't set upper to " + i + " < lower");
IntPair newv = new IntPair(oldv.lower, i);
if (values.compareAndSet(oldv, newv)) return;
}
}
public int getUpper() {
return values.get().upper;
}
public int getLower() {
return values.get().lower;
}