Java死锁的例子-蒲公英云

Java死锁的例子

桃扇骨 2022-07-14 07:07 235阅读 0赞

1、一个Java死锁的程序

public class DeadLock {
    private String A = "A";
    private String B = "B";
    public static void main(String[] args) {
        new DeadLock().deadLock();
    }
    private void deadLock() {
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (A) {
                    try {
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    synchronized (B) {
                        System.out.println("Thread t1");
                    }
                }
            }
        });
        Thread t2 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (B) {
                    try {
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    synchronized (A) {
                        System.out.println("Thread t2");
                    }
                }
            }
        });
        t1.start();
        t2.start();
    }
}

2、编译运行Java程序

[root@cent01 javatest]# javac DeadLock.java 
[root@cent01 javatest]# java DeadLock

3、利用 jps 查看当前的Java程序

[root@cent01 ~]# jps
2672 Jps
2661 DeadLock

4、利用 jstack 查看死锁信息

[root@cent01 ~]# jstack 2661
Found one Java-level deadlock:
=============================
"Thread-1":
  waiting to lock monitor 0x092cba78 (object 0xa1847358, a java.lang.String),
  which is held by "Thread-0"
"Thread-0":
  waiting to lock monitor 0x092cadd0 (object 0xa1847380, a java.lang.String),
  which is held by "Thread-1"
Java stack information for the threads listed above:
===================================================
"Thread-1":
    at DeadLock$2.run(DeadLock.java:42)
    - waiting to lock <0xa1847358> (a java.lang.String)
    - locked <0xa1847380> (a java.lang.String)
    at java.lang.Thread.run(Thread.java:745)
"Thread-0":
    at DeadLock$1.run(DeadLock.java:24)
    - waiting to lock <0xa1847380> (a java.lang.String)
    - locked <0xa1847358> (a java.lang.String)
    at java.lang.Thread.run(Thread.java:745)
Found 1 deadlock.