static Lock lock = new ReentrantLock();public static void main(String[] args) throws InterruptedException {


    lock.lock();//其他沒拿到鎖的卡住不動

    Thread thread = new Thread(new Runnable() {
      @Override
      public void run() {
        System.out.println("start to get lock Interruptibly");
        lock.unlock(); //看看會發(fā)生什么，注釋掉再看看
        lock.lock();
        System.out.println("拿到鎖");
        lock.unlock();
        System.out.println("釋放鎖");
      }
    });
    thread.start();

    Thread.sleep(3000);
    lock.unlock();
  }

public class MyLock implements Lock {
  //多并發(fā)調(diào)用 0-未占用 大于0-占用
  AtomicInteger state = new AtomicInteger();

  Thread ownerThread = new Thread();

  //等待鎖的隊列
  LinkedBlockingQueue<Thread> waiters = new LinkedBlockingQueue();

  @Override
  public void lock() {
    if (!tryLock()) { //先搶鎖，所以是非公平鎖
      //沒拿到鎖,放到隊列中去進行排隊
      waiters.add(Thread.currentThread());
      //等待被喚醒
      for (; ; ) {
        if (tryLock()) { //非公平鎖情況下，喚醒過來繼續(xù)獲取鎖
          waiters.poll(); //獲取鎖成功把自己從隊列中取出來
          return;
        } else  //獲取鎖失敗
          LockSupport.park(); //線程阻塞
      }
    }
  }


  @Override
  public boolean tryLock() {
    if (state.get() == 0) { //如果鎖沒被占用
      if (state.compareAndSet(0, 1)) { //如果成功拿到鎖
        ownerThread = Thread.currentThread();  //占用鎖線程改為當前線程
        return true;
      }
    }
    return false;
  }

  @Override
  public void unlock() {

    if (ownerThread != Thread.currentThread()) //占用鎖線程不是當前線程無法釋放鎖
      throw new RuntimeException("非法調(diào)用,當前鎖不屬于你");

    if (state.decrementAndGet() == 0) //如果成功釋放鎖
      ownerThread = null; //占用鎖線程置空
    //通知其他線程
//    Thread thread = null;
//
//    while ((thread = waiters.peek()) != null)
//      LockSupport.unpark(thread);
    Thread thread = waiters.peek(); //獲取隊列頭部線程，線程還留在隊列中
    if (thread != null) {
      LockSupport.unpark(thread); //取消阻塞
    }
  }



  @Override
  public boolean tryLock(long time, TimeUnit unit) throws InterruptedException {
    return false;
  }


  @Override
  public Condition newCondition() {
    return null;
  }

  @Override
  public void lockInterruptibly() throws InterruptedException {

  }
}

@Override
  public void lock() {
    checkQueue（）;//線程來的時候先不獲取鎖，而是先檢查隊列中有沒有等待的線程，如果有，直接放入隊列，如果沒有，再去獲取鎖
    if (!tryLock()) { //先搶鎖，所以是非公平鎖
      //沒拿到鎖,放到隊列中去進行排隊
      waiters.add(Thread.currentThread());
      //等待被喚醒
      for (; ; ) {
        if (tryLock()) { //非公平鎖情況下，喚醒過來繼續(xù)獲取鎖
          waiters.poll(); //獲取鎖成功把自己從隊列中取出來
          return;
        } else  //獲取鎖失敗
          LockSupport.park(); //線程阻塞
      }
    }
  }