多线程下非阻塞堆栈的实现

此实现来自：点击打开链接

具体如下：

package com.test;

import java.util.concurrent.atomic.AtomicReference;

public class ConcurrentStack<E>
{
    private AtomicReference<Node<E>> head = new AtomicReference<Node<E>>();
    
    public void push(E item)
    {
        Node<E> newHead = new Node<E>(item);
        Node<E> oldHead;
        
        do
        {
            oldHead = head.get();
            newHead.next = oldHead;
        }while(!head.compareAndSet(oldHead, newHead));
    }
    
    public E pop()
    {
        Node<E> newHead;
        Node<E> oldHead;
        
        for(;;)
        {
            oldHead = head.get();
            newHead = oldHead.next;
            if(head.compareAndSet(oldHead, newHead))
            {
                return oldHead.item;
            }
        }
    }
    
    static class Node<E>
    {
        final E item;
        Node<E> next;
        
        public Node(E item)
        {
            this.item = item;
        }
    }
}