synchronized 实现死锁

古城微笑少年丶 2022-01-22 10:07 293阅读 0赞

synchronized首先明确锁的是对象而不是方法代码，如果一个对象有两个方法，两个线程分别调用其中一个方法，如果锁传入的参数为 同一对象与不同对象，线程运行结果是不一样的  
死锁代码如下

package com.hanshow.wise.portal.center.controller.common;
    
    public class Test11 {
    	public static void main(String[] args) {
    		Person person = new Person();
    		MyThreadAA a = new MyThreadAA(person);
    		MyThreadAA b = new MyThreadAA(person);
    		new Thread(a, "张三").start();
    		new Thread(b, "李四").start();
    	}
    	
    }
    class MyThreadAA implements Runnable{
    	public Person person;
    	public static Person p1 = new Person();
    	public static Person p2 = new Person();
    	MyThreadAA (Person person) {
    		this.person = person;
    	}
    	
    	@Override
    	public void run() {
    		String str = Thread.currentThread().getName();
    		if (str.equals(person.name1)) {
    				synchronized (p1) {
    					try {
    						person.eat();
    						Thread.sleep(2000);
    						System.out.println(Thread.currentThread().getName());
    						synchronized (p2) {
    							person.sleep();
    						}
    						
    						
    					} catch (InterruptedException e) {
    						// TODO Auto-generated catch block
    						e.printStackTrace();
    					}
    				}
    			
    			
    		} else {
    				synchronized (p2) {
    					try {
    						person.sleep();
    						Thread.sleep(2000);
    						System.out.println(Thread.currentThread().getName());
    						synchronized (p1) {
    							person.eat();
    						}
    						
    					} catch (InterruptedException e) {
    						// TODO Auto-generated catch block
    						e.printStackTrace();
    					}
    			}
    			
    		}
    		
    	}
    	
    }
    
    class Person {
    	public String name1 = "张三";
    	public String name2 = "李四";
    	public void eat() {
    		System.out.println("吃饭饭");
    	}
    	public void sleep() {
    		System.out.println("睡觉觉");
    	}
    }