import java.util.Date;

public class TestYield{
    public static void main(String[] args){
        Thread t1 = new MyThread(false);
        Thread t2 = new MyThread(true);
        Thread t3 = new MyThread(false);
        t1.start();
        t2.start();
        t3.start();
    }    
}

class MyThread extends Thread{
    private boolean flag;
    public MyThread(boolean flag){
        this.flag = flag;
    }
    public void setFlag(boolean flag){
        this.flag = flag;
    }
    public void run(){
        long start = new Date().getTime();
        for(int i=0;i<500;i++){
            if(flag)
                Thread.yield();
            System.out.print(this.getName() + ": " + i + "\t");
        }
        long end = new Date().getTime();
        System.out.println("\n" + this.getName() + "执行时间: " + (end - start) + "毫秒");
    }
}