searover

class CacheData {
  Object data;
  volatile boolean isCacheValid;
  final ReadWriteLock rwl = new ReentrantReadWriteLock();
  // 读锁
  final Lock r = rwl.readLock();
  // 写锁
  final Lock w = rwl.writeLock();
  
  void processCacheData() {

searover

/**
 * @author luxz
 * @date 2020/6/27-3:31 AM
 * 如果执行乐观读操作期间，存在写操作，会把乐观读升级为悲观读锁
 */
public class Point {
    private int x, y;
    final StampedLock sl = new StampedLock();

    int distanceFromOrigin() {

searover

class GuardedObject<T> {
  // 受保护的对象
  T obj;
  final Lock lock = new ReentrantLock();
  final Condition done = lock.newCondition();
  final int timeout = 1;
  
  T get(Predicate<T> p) {
    lock.lock();
    try{