package com.webgame.game.job;

import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;

/** * Deadlock detection * Date: 2019/7/30. * Author:chongxin */
public class DeadlockCheck {
    private static final ThreadMXBean mbean = ManagementFactory.getThreadMXBean();

    public static void checkForDeadlocks(a) {
        long[] ids = findDeadlockedThreads();
        if(ids ! =null && ids.length > 0) {
            ThreadInfo[] threadInfo = mbean.getThreadInfo(ids, true.true);
            for(ThreadInfo info : threadInfo) { System.out.println(info); }}}private static long[] findDeadlockedThreads() {
        if (mbean.isSynchronizerUsageSupported()) {
            return mbean.findDeadlockedThreads();
        } else {
            returnmbean.findMonitorDeadlockedThreads(); }}}Copy the code
package com.webgame.game.job;

import java.util.Timer;
import java.util.TimerTask;

public class DeadLockDemo extends Thread {
    private static Object obj1 = new Object();
    private static Object obj2 = new Object();
    private boolean flag;

    public DeadLockDemo(boolean flag){
        this.flag = flag;
    }

    @Override
    public void run(a){
        System.out.println(Thread.currentThread().getName() + "Run");

        if(flag){
            synchronized(obj1){
                System.out.println(Thread.currentThread().getName() + Obj1 has been locked);
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                synchronized(obj2){
                    // Not available
                    System.out.println("One second later,"+Thread.currentThread().getName()
                            + "Lock obj2"); }}}else{
            synchronized(obj2){
                System.out.println(Thread.currentThread().getName() + Obj2 has been locked);
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                synchronized(obj1){
                    // Not available
                    System.out.println("One second later,"+Thread.currentThread().getName()
                            + "Lock obj1"); }}}}public static void main(String[] args) throws InterruptedException {

        Thread t1 = new Thread(new DeadLockDemo(true), Thread 1 "");
        Thread t2 = new Thread(new DeadLockDemo(false), Thread 2 "");
        Timer timer = new Timer();
        timer.schedule(new TimerTask() {
            public void run(a) { DeadlockCheck.checkForDeadlocks(); }},2000 , 1000); t1.start(); t2.start(); }}Copy the code