死锁问题

其实死锁的概念在操作系统中也有提及，它是指两个线程相互持有对方需要的锁，但是又迟迟不释放，导致程序卡住：

  例如：

public static void main(String[] args) throws InterruptedException {
    Object o1 = new Object();
    Object o2 = new Object();
    Thread t1 = new Thread(() -> {
        synchronized (o1){
            try {
                Thread.sleep(1000);
                synchronized (o2){
                    System.out.println("线程1");
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    });
    Thread t2 = new Thread(() -> {
        synchronized (o2){
            try {
                Thread.sleep(1000);
                synchronized (o1){
                    System.out.println("线程2");
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    });
    t1.start();
    t2.start();
}

• jstack 检测死锁