@Override
    public boolean relaxedOffer(E e)
    {
        if (null == e)
        {
            throw new NullPointerException();
        }
        final int parallelQueuesMask = this.parallelQueuesMask;
        int start = (int) (Thread.currentThread().getId() & parallelQueuesMask);
        final MpscArrayQueue<E>[] queues = this.queues;
        if (queues[start].failFastOffer(e) == 0)
        {
            return true;
        }
        else
        {
            // we already offered to first queue, try the rest
            for (int i = start + 1; i < start + parallelQueuesMask + 1; i++)
            {
                if (queues[i & parallelQueuesMask].failFastOffer(e) == 0)
                {
                    return true;
                }
            }
            // this is a relaxed offer, we can fail for any reason we like
            return false;
        }
    }
Use a set number of parallel MPSC queues to diffuse the contention on tail.
jctools-core/src/main/java/org/jctools/queues/MpscCompoundQueue.java