private boolean offerSlowPath(final E[] buffer, final long mask, final long producerIndex)
    {
        final int lookAheadStep = this.lookAheadStep;
        if (null == lvRefElement(buffer,
            calcCircularRefElementOffset(producerIndex + lookAheadStep, mask)))
        {
            producerLimit = producerIndex + lookAheadStep;
        }
        else
        {
            final long offset = calcCircularRefElementOffset(producerIndex, mask);
            if (null != lvRefElement(buffer, offset))
            {
                return false;
            }
        }
        return true;
    }
{@inheritDoc}
<p>
This implementation is correct for single producer thread use only.
jctools-core/src/main/java/org/jctools/queues/SpscArrayQueue.java