Java 병렬 새 위젯의 Exchanger

import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.Exchanger;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

class ExchangerProducer implements Runnable {
    private List<Fat> holder;
    private Exchanger<List<Fat>> exchanger;
    public ExchangerProducer(Exchanger<List<Fat>> exchanger, List<Fat> holder) {
        this.exchanger = exchanger;
        this.holder = holder;
    }
    @Override
    public void run() {
        try {
            while(!Thread.interrupted()) {
                //    
                for (int i = 0;i < ExchangerDemo.size; i++) {
                    holder.add(new Fat());
                }
                //    
                holder = exchanger.exchange(holder);
            }
        } catch (InterruptedException e) {
        }
        System.out.println("Producer stopped.");
    }
}

class ExchangerConsumer implements Runnable {
    private List<Fat> holder;
    private Exchanger<List<Fat>> exchanger;
    private volatile Fat value;
    private static int num = 0;
    public ExchangerConsumer(Exchanger<List<Fat>> exchanger, List<Fat> holder) {
        this.exchanger = exchanger;
        this.holder = holder;
    }
    @Override
    public void run() {
        try {
            while(!Thread.interrupted()) {
                //    
                holder = exchanger.exchange(holder);
                //         
                for (Fat x : holder) {
                    num++;
                    value = x;
                    //        ，   CopyOnWriteArrayList      
                    holder.remove(x);
                }
                if (num % 10000 == 0) {
                    System.out.println("Exchanged count=" + num);
                }
            }
        } catch (InterruptedException e) {
            
        }
        System.out.println("Consumer stopped. Final value: " + value);
    }
}

public class ExchangerDemo {
    static int size = 10;
    static int delay = 5; // 
    public static void main(String[] args) throws Exception {
        ExecutorService exec = Executors.newCachedThreadPool();
        List<Fat> producerList = new CopyOnWriteArrayList<>();
        List<Fat> consumerList = new CopyOnWriteArrayList<>();
        Exchanger<List<Fat>> exchanger = new Exchanger<>();
        exec.execute(new ExchangerProducer(exchanger, producerList));
        exec.execute(new ExchangerConsumer(exchanger, consumerList));
        TimeUnit.SECONDS.sleep(delay);
        exec.shutdownNow();
    }
}

class Fat {
    private volatile double d;
    private static int counter = 1;
    private final int id = counter++;
    public Fat() {
        //         
        for (int i = 1; i<10000; i++) {
            d += (Math.PI + Math.E) / (double)i;
        }
    }
    public void print() {System.out.println(this);}
    public String toString() {return "Fat id=" + id;}
}

Exchanged count=10000
Exchanged count=20000
Exchanged count=30000
Exchanged count=40000
Exchanged count=50000
Exchanged count=60000
Exchanged count=70000
Exchanged count=80000
Consumer stopped. Final value: Fat id=88300
Producer stopped.