SpscLAQChunked.java

@Override
protected final boolean offerColdPath(E[] buffer, long mask, E e, long pIndex, long offset) {
  // use a fixed lookahead step based on buffer capacity
  final long lookAheadStep = (mask + 1) / 4;
  long pBufferLimit = pIndex + lookAheadStep;
  long pQueueLimit = producerQueueLimit;

  // out of known space
  if (pIndex >= pQueueLimit) {
    // we tested against a potentially out of date queue limit, refresh it
    long cIndex = lvConsumerIndex();
    producerQueueLimit = pQueueLimit = cIndex + maxQueueCapacity;
    // if we're full we're full
    if (pIndex >= pQueueLimit) {
        return false;
    }
  }
  // if buffer limit is after queue limit we use queue limit. We need to handle overflow so
  // cannot use Math.min
  if (pBufferLimit - pQueueLimit > 0) {
    pBufferLimit = pQueueLimit;
  }

  // go around the buffer or add a new buffer
  if (pBufferLimit > pIndex + 1 && // there's sufficient room in buffer/queue to use pBufferLimit
      null == lvElement(buffer, calcElementOffset(pBufferLimit, mask))) {
    producerBufferLimit = pBufferLimit - 1; // joy, there's plenty of room
    writeToQueue(buffer, e, pIndex, offset);
  }
  else if (null == lvElement(buffer, calcElementOffset(pIndex + 1, mask))) { // buffer is not full
      writeToQueue(buffer, e, pIndex, offset);
  }
  else {
      // we got one slot left to write into, and we are not full. Need to link new buffer.
      // allocate new buffer of same length
      final E[] newBuffer = allocate((int)(mask + 2));
      producerBuffer = newBuffer;

      linkOldToNew(pIndex, buffer, offset, newBuffer, offset, e);
  }
  return true;
}