Stop The World

import java.util.HashMap;

/** * Created by wb-xxd249566 on 2017/4/5. * -Xmx1g -Xms1g -Xmn512k -XX:+UseSerialGC -Xloggc:gc.log -XX:+PrintGCDetails */public class StopWorldTest {    public static class MyThread extends Thread{        HashMap map = new HashMap();

@Override        public void run() {            try {                while (true){                    if (map.size()*512/1024/1024>=550){                        map.clear();                        System.out.println("clean map");                    }                    byte[] b1;                    for (int i=0;i<100;i++){                        b1 = new byte[512];                        map.put(System.nanoTime(),b1);                    }                    Thread.sleep(1);                }            }catch (Exception e){

}        }    }

public static class PrintThread extends Thread{        public static final long startTime = System.currentTimeMillis();

@Override        public void run() {            try {                while (true){                    long t = System.currentTimeMillis()-startTime;                    System.out.println(t/1000+"."+t%1000);                    Thread.sleep(100);                }            }catch (Exception e){

}        }    }

public static void main(String[] args){        MyThread t = new MyThread();        PrintThread p = new PrintThread();        t.start();        p.start();    }}