private void linkOut(Entry entry) {
        Entry head = slots[entry.slot];
        if (entry.next == entry) {
            slots[entry.slot] = null;
        } else {
            entry.prev.next = entry.next;
            entry.next.prev = entry.prev;
            if (head == entry) {
                slots[entry.slot] = entry.next;
            }
        }
        entry.next = null;
        entry.prev = null;
        --counts[entry.slot];
    }
@author <a href="mailto:havardpe@yahoo-inc.com">Haavard Pettersen</a>
@author Simon Thoresen Hult
jdisc_core/src/main/java/com/yahoo/jdisc/core/ScheduledQueue.java