Performance Profiling and Optimization Questions

import java.util.concurrent.atomic.*;

public class LockFreeQueue<T> {
    static final class Node<E> {
        final E value;
        final AtomicReference<Node<E>> next;
        Node(E v){ value = v; next = new AtomicReference<>(null); }
    }

    // Use AtomicReference for head/tail; can use AtomicStampedReference to avoid ABA
    private final AtomicReference<Node<T>> head;
    private final AtomicReference<Node<T>> tail;

    public LockFreeQueue(){
        Node<T> dummy = new Node<>(null);
        head = new AtomicReference<>(dummy);
        tail = new AtomicReference<>(dummy);
    }

    public void enqueue(T item){
        Node<T> node = new Node<>(item);
        while(true){
            Node<T> t = tail.get();
            Node<T> next = t.next.get();
            if (t == tail.get()){
                if (next == null){
                    if (t.next.compareAndSet(null, node)){
                        // try to swing tail to the inserted node
                        tail.compareAndSet(t, node);
                        return;
                    }
                } else {
                    // help advance tail
                    tail.compareAndSet(t, next);
                }
            }
        }
    }

    public T dequeue(){
        while(true){
            Node<T> h = head.get();
            Node<T> t = tail.get();
            Node<T> next = h.next.get();
            if (h == head.get()){
                if (h == t){
                    if (next == null) return null; // empty
                    // tail is lagging; help advance
                    tail.compareAndSet(t, next);
                } else {
                    T val = next.value;
                    if (head.compareAndSet(h, next)){
                        return val;
                    }
                }
            }
        }
    }
}

func BenchmarkMarshal(b *testing.B) {
  payload := makeTestPayload()
  b.ReportAllocs()
  b.ResetTimer()
  for i := 0; i < b.N; i++ {
    _, _ = json.Marshal(payload)
  }
}