单生产者 单消费者情景下 无锁仓库
使用链表实现 链表中时刻保有两个元素。在任何并发的操作情况下，只要保证赋值是原子操作，即可保证无锁的并发安全。可能导致消费延迟到下一次申请，但是不会出现未消费产品。

package gt.lockFreeList;public class List<T> {private Node<T> head = new Node<T>();private Node<T> tail = new Node<T>();private boolean used[] = { true, true };public List() {head.setNext(tail);}public void put(T t) {Node<T> temp = new Node<T>(t);tail.setNext(temp);tail = temp;if (used[0]) {pop();used[1] = false;}}public T get() {T t = null;while (canPop() && t == null) {// when there are more than two elements// in the listif (used[0]) {pop();} else {t = pop();}}if (t == null) {// when there are exactly two elements in the list keep// them as placeholderif (used[0]) {if (used[1]) {} else {used[1] = true;t = head.getNext().getData();}} else {used[0] = true;t = head.getData();}}return t;}public T pop() {Node<T> h = head;head = h.getNext();used[0] = used[1];return h.getData();}public boolean canPop() {return !(head.getNext() == tail);}}