import java.util.concurrent.*;
class Chopstick //筷子
{
    private boolean taken=false;
    static int count=0;
    final int id=count++;
    public Chopstick() 
    {
    }
    public synchronized void take()
    {
        try
        {
            while(taken==true)
               wait();
            taken=true;
        }
        catch(InterruptedException e)
        {
            System.out.println("ssssssssssssssssssssssssssssss"+id);
        }
    }
    public synchronized void drop()
    {
        taken=false;
        notifyAll();
    }
}
class Philosopher implements Runnable  //哲学家
{
    private Chopstick left;
    private Chopstick right;
    private final int id;
    public Philosopher(Chopstick left,Chopstick right,int id)
    {
        this.left=left;
        this.right=right;
        this.id=id;
    }
    public void run()
    {
        try
        {
            while(!Thread.interrupted())
            {
                System.out.println(this+" is thinking!");
                TimeUnit.MILLISECONDS.sleep(100);
                System.out.println(this+" left!");
                left.take();
                System.out.println(this+" right!");
                right.take();
                System.out.println(this+" is eating!");
                TimeUnit.MILLISECONDS.sleep(200);
                left.drop();
                right.drop();
            }
        }
        catch(InterruptedException e)
        {
            System.out.println(this+" Interrupted");
        }
    }
    public String toString()
    {
        return "Philosopher "+id;
    }
}
public class DiningPhilosophers   //哲学家进餐
{
    public static void main(String[] args)throws Exception
    {
        int size=3;//当size为单数是为什么程序无法中断，而复数则可以。
        ExecutorService exec=Executors.newCachedThreadPool();
        Chopstick []chopsticks=new Chopstick[size];
        for(int i=0;i<size;i++)
        {
            chopsticks[i]=new Chopstick();
        }
        for(int i=0;i<size;i++)
        {
            exec.execute(new Philosopher(chopsticks[i],chopsticks[(i+1)%size],i));
        }
        TimeUnit.SECONDS.sleep(1);
        exec.shutdownNow();
    }
}
问题：当size为单数是为什么程序无法中断，而复数则可以。