java - 为什么下面的代码有死锁？

Question

谁能告诉我为什么这段代码会死锁？

public class BrokenOrderingReentredLock implements Runnable {

    private Object lock1 = new Object();
    private Object lock2 = new Object();

    public static void main(String[] args) throws InterruptedException {
        BrokenOrderingReentredLock runnable = new BrokenOrderingReentredLock();
        Thread thread1 = new Thread(runnable, "thread1");
        Thread thread2 = new Thread(runnable, "thread2");
        thread1.start();
        Thread.sleep(500);
        thread2.start();
    }

    @Override
    public void run() {
        try {
            String threadName = Thread.currentThread().getName();
            synchronized (lock1) {
                System.out.println(threadName + " has lock1");
                synchronized (lock2) {
                    System.out.println(threadName + " has lock2");
                        System.out.println(threadName + " reenters lock1");
                        lock1.wait();
                        lock2.wait();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    } }

Answer 1

Thread1 启动并获取lock1 和lock2。 Thread1 释放lock1(使用lock1.wait())。

Thread2 启动并获取 lock1 然后永远等待 lock2。 Thread1 正在等待通知，但永远不会。

僵局!