JUC-多线程锁-死锁以及jstack堆栈跟踪工具的运用

╰+哭是因爲堅強的太久メ 2024-04-01 09:58 60阅读 0赞

![17cbac45d4ba4779b0825a71347bbc1c.png][]![3e080c8f100040e4ba6a1565e7c890dc.png][]

package com.nanjing.juc;
    
    import java.util.concurrent.TimeUnit;
    
    public class DeadLock_18 {
        //创建两个对象
        static Object a = new Object();
        static Object b = new Object();
    
        public static void main(String[] args) {
            new Thread(()->{
                synchronized (a) {
                    System.out.println(Thread.currentThread().getName()+" 持有锁a，试图获取锁b");
                    try {
                        TimeUnit.SECONDS.sleep(1);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    synchronized (b) {
                        System.out.println(Thread.currentThread().getName()+" 获取锁b");
                    }
                }
            },"A").start();
    
            new Thread(()->{
                synchronized (b) {
                    System.out.println(Thread.currentThread().getName()+" 持有锁b，试图获取锁a");
                    try {
                        TimeUnit.SECONDS.sleep(1);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    synchronized (a) {
                        System.out.println(Thread.currentThread().getName()+" 获取锁a");
                    }
                }
            },"B").start();
        }
    }

验证是否死锁

查看运行的Java进程，命令： jps -l

![50052ce6ea6b4067a205768533a2430b.png][]

用堆栈跟踪工具jstack查看堆栈信息，命令：jstack 进程号

![e8eebecb217b4be1b962adc1d521dcff.png][]

[17cbac45d4ba4779b0825a71347bbc1c.png]: https://img-blog.csdnimg.cn/17cbac45d4ba4779b0825a71347bbc1c.png
[3e080c8f100040e4ba6a1565e7c890dc.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/c802f561e0ab4e6dab7b15c98d0e0a7a.png
[50052ce6ea6b4067a205768533a2430b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/f639a32dd8ca401db327402f25968c35.png
[e8eebecb217b4be1b962adc1d521dcff.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/b7b78d1fc72f44f28dba14c8f1242b84.png