SpscLAQnewBufferPoll.java

private E newBufferPoll(E[] buffer, final long index) {
  final E[] newBuffer = lvNextArrayAndUnlink(buffer);
  final long newMask = newBuffer.length - 2; // because buffer last element is for linking
  
  // update consumer view on buffer
  consumerBuffer = nextBuffer;
  consumerMask = newMask;
  
  // poll element, must be visible in new buffer
  final long offsetInNew = calcElementOffset(index, newMask);
  final E n = lvElement(newBuffer, offsetInNew); // volatile: n = nextBuffer[index&newMask];
  if (null == n) {
    throw new IllegalStateException("new buffer must have at least one element");
  }
  
  soConsumerIndex(index + 1); // ordered: consumerIdex = index + 1;
  soElement(newBuffer, offsetInNew, null); // ordered: nextBuffer[index&newMask] = null;
  return n;
}

protected final E[] lvNextArrayAndUnlink(E[] curr) {
  final long nextArrayOffset = nextArrayOffset(curr);
  final E[] nextBuffer = (E[]) lvElement(curr, nextArrayOffset);
  // prevent GC nepotism
  soElement(curr, nextArrayOffset, null);
  return nextBuffer;
}