死锁现象——计算机各领域都有的现象

多个线程相互等待对方释放资源，导致都无法执行的现象，是一种常见的现象

以下举例并且对代码进行解读

public class A {

private static Object lock1 = new Object();

private static Object lock2 = new Object();

public static void main(String[] args) {

    new Thread(){

//Thread并发线程

        @Override

        public void run(){

            synchronized (lock1){

                System.out.println("线程1得到了锁1");

//这里synchronized保证同一时刻只有一个线程达到临界区

                try {

                    Thread.sleep(1000);

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

                synchronized (lock2){

                    System.out.println("线程1得到锁2");

                }

            }

            System.out.println("线程1结束了");

        }

    }.start();

    new Thread(){

        @Override

        public void run(){

            synchronized (lock2){

                System.out.println("线程2得到了锁2");

                try {

                    Thread.sleep(1000);

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

                synchronized (lock1){

                    System.out.println("线程2得到锁1");

                }

            }

            System.out.println("线程2结束了");

        }

    }.start();

 }

  }

//三条线程会同时达到临界区，但是会因为锁的作用，都得到了执行下一步