Java基础进阶多线程-死锁

我就是我 2023-10-08 16:54 80阅读 0赞

两个线程共享两个对象o1,o2

线程1先把o1锁住，再把o2锁住

线程2先把o2锁住，再把o1锁住

此时程序会静止不动

图解（引自b站老杜javase零基础）：  
![在这里插入图片描述][92851b441bba42f5acec15ae75c1e8cc.png_pic_center]

public class DeadLock {
        
        public static void main(String[] args) {
        
    
            Object o1 = new Object();
            Object o2 = new Object();
    
            // t1和t2两个线程共享o1,o2
            Thread t1 = new MyThread1(o1,o2);
            Thread t2 = new MyThread2(o1,o2);
    
            t1.start();
            t2.start();
        }
    }
    
    class MyThread1 extends Thread{
        
        Object o1;
        Object o2;
        public MyThread1(Object o1,Object o2){
        
            this.o1 = o1;
            this.o2 = o2;
        }
    
        public void run(){
        
            synchronized(o1){
        
                try {
        
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
        
                    e.printStackTrace();
                }
                synchronized (o2){
        
                }
            }
        }
    
    }
    
    class MyThread2 extends Thread{
        
        Object o1;
        Object o2;
        public MyThread2(Object o1,Object o2){
        
            this.o1 = o1;
            this.o2 = o2;
        }
    
        public void run(){
        
            synchronized (o2){
        
                try {
        
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
        
                    e.printStackTrace();
                }
               synchronized (o1){
        
    
               }
                }
            }
        }

#### 运行结果： ####

![在这里插入图片描述][87d5c341e6aa4a5fb56b337cd380daa9.png]

[92851b441bba42f5acec15ae75c1e8cc.png_pic_center]: https://img-blog.csdnimg.cn/92851b441bba42f5acec15ae75c1e8cc.png#pic_center
[87d5c341e6aa4a5fb56b337cd380daa9.png]: https://img-blog.csdnimg.cn/87d5c341e6aa4a5fb56b337cd380daa9.png