/**
* Constrains the values of all delays in the queue to be within Long.MAX_VALUE of each other, to
* avoid overflow in compareTo. This may occur if a task is eligible to be dequeued, but has not
* yet been, while some other task is added with a delay of Long.MAX_VALUE.
*/
private long overflowFree(long delay) {
Delayed head = (Delayed) super.getQueue().peek();
if (head != null) {
long headDelay = head.getDelay(NANOSECONDS);
if (headDelay < 0 && (delay - headDelay < 0)) delay = Long.MAX_VALUE + headDelay;
}
return delay;
}
public int compareTo(Delayed other) {
if (other == this) // compare zero if same object
return 0;
if (other instanceof ScheduledFutureTask) {
ScheduledFutureTask<?> x = (ScheduledFutureTask<?>) other;
long diff = time - x.time;
if (diff < 0) return -1;
else if (diff > 0) return 1;
else if (sequenceNumber < x.sequenceNumber) return -1;
else return 1;
}
long diff = (getDelay(NANOSECONDS) - other.getDelay(NANOSECONDS));
return (diff < 0) ? -1 : (diff > 0) ? 1 : 0;
}