/**
* Offer two elements at the same time.
*
* <p>Don't use the regular offer() with this at all!
*
* @param first
* @param second
* @return
*/
public boolean offer(T first, T second) {
final AtomicReferenceArray<Object> buffer = producerBuffer;
final long p = producerIndex;
final int m = producerMask;
int pi = calcWrappedOffset(p + 2, m);
if (null == lvElement(buffer, pi)) {
pi = calcWrappedOffset(p, m);
soElement(buffer, pi + 1, second);
soProducerIndex(p + 2);
soElement(buffer, pi, first);
} else {
final int capacity = buffer.length();
final AtomicReferenceArray<Object> newBuffer = new AtomicReferenceArray<>(capacity);
producerBuffer = newBuffer;
pi = calcWrappedOffset(p, m);
soElement(newBuffer, pi + 1, second); // StoreStore
soElement(newBuffer, pi, first);
soNext(buffer, newBuffer);
soProducerIndex(p + 2); // this ensures correctness on 32bit platforms
soElement(buffer, pi, HAS_NEXT); // new buffer is visible after element is
}
return true;
}
private void resize(
final AtomicReferenceArray<Object> oldBuffer,
final long currIndex,
final int offset,
final T e,
final long mask) {
final int capacity = oldBuffer.length();
final AtomicReferenceArray<Object> newBuffer = new AtomicReferenceArray<>(capacity);
producerBuffer = newBuffer;
producerLookAhead = currIndex + mask - 1;
soProducerIndex(currIndex + 1); // this ensures correctness on 32bit platforms
soElement(newBuffer, offset, e); // StoreStore
soNext(oldBuffer, newBuffer);
soElement(oldBuffer, offset, HAS_NEXT); // new buffer is visible after element is
// inserted
}
private static final <E> Object lvElement(AtomicReferenceArray<Object> buffer, int offset) {
return buffer.get(offset);
}
private static final void soElement(AtomicReferenceArray<Object> buffer, int offset, Object e) {
buffer.lazySet(offset, e);
}
@SuppressWarnings("unchecked")
private AtomicReferenceArray<Object> lvNext(AtomicReferenceArray<Object> curr) {
return (AtomicReferenceArray<Object>) lvElement(curr, calcDirectOffset(curr.length() - 1));
}
private void soNext(AtomicReferenceArray<Object> curr, AtomicReferenceArray<Object> next) {
soElement(curr, calcDirectOffset(curr.length() - 1), next);
}