线程死锁示例

线程死锁：

package com.iotek.synchronizedtest;

public class DeadThread {

    /**
     * 线程死锁示例
     * 相互等待锁的释放,导致死锁,应避免同步块里面出现锁的嵌套!!!
     * @param args
     */
    public static void main(String[] args) {
        Example example = new Example();
        DieThread1 thread1 = new DieThread1(example);
        thread1.start();
        DieThread2 thread2 = new DieThread2(example);
        thread2.start();
        
    }

}

class DieThread1 extends Thread {
    private Example example = null;

    public DieThread1(Example example) {
        super();
        this.example = example;
    }

    @Override
    public void run() {
        example.method1();
    }
}

class DieThread2 extends Thread {
    private Example example = null;

    public DieThread2(Example example) {
        super();
        this.example = example;
    }

    @Override
    public void run() {
        example.method2();
    }
}

class Example {
    private Object obj1 = new Object();
    private Object obj2 = new Object();

    public void method1() {
        synchronized (obj1) {
            // 同步代码块,获取对象obj1的锁
            try {
                Thread.sleep(1000); // 线程等待
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (obj2) {
                // 获取对象obj1的锁的同时,获取obj2的锁
                System.out.println("method1");
            }
        }
    }

    public void method2() {
        synchronized (obj2) {
            // 同步代码块,获取对象obj2的锁
            try {
                Thread.sleep(1000); // 线程等待
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (obj1) {
                // 获取对象obj2的锁的同时,获取obj1的锁
                System.out.println("method2");
            }
        }
    }

}