使用与CyclicBarrier

Question

我试图在协调的方法场景 - 发送和接收中学习更多使用带有CyclicBarrier的join（）。基本代码来自之前的海报，我修改它以运行某个循环帐户（前10次）。代码为：

import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.BrokenBarrierException;

public class Test {

    public static void main(String[] args) {
        CyclicBarrier barrier = new CyclicBarrier(2);
        Receiver receiver = new Receiver(barrier);
        Sender sender = new Sender(barrier);

        Thread r = new Thread(receiver);
        Thread s = new Thread(sender);  
        r.start();
        s.start();
        try {
            r.join();
            s.join();       
        } catch (InterruptedException e) {
             e.printStackTrace();
        }
        System.out.println("It is over....");
    }
}

class Sender implements Runnable {

    private CyclicBarrier barrier;
    static boolean stop = false;
    private static int i = 1;
    public static int limit = 10 ;

    public Sender(CyclicBarrier barrier) {
        this.barrier = barrier;
    }

    @Override
    public void run() {
        while ( !stop ) {
            try {
                // Wait for notify.
                Thread.sleep(1);
                // Now do SEND.
                int j = getI();
                System.out.println(j);  
                System.out.println("SEND -" + j );
                barrier.await();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (BrokenBarrierException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }
    }

    public static int getI() {
        return i;
    }

    public static void setI(int i) {
        Sender.i = i;
    }
}

class Receiver implements Runnable {

    private CyclicBarrier barrier;    

    public Receiver(CyclicBarrier barrier) {
        this.barrier = barrier;
    }

    @Override
    public void run() {
        while ( Sender.getI() <= Sender.limit ) {   
            // Then notify.
            try {
                barrier.await();
                int k = Sender.getI();                              
                // Wait for ACK (the sleep just simulates that).
                System.out.println("ACK -" + k );
                Sender.setI(++k);
                if ( Sender.getI() > Sender.limit ) {
                    System.out.println(k);
                    Sender.stop = true;
       //           barrier.reset();
                }
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (BrokenBarrierException e) {
                e.printStackTrace();
            }
        }
    }
}

然而，我遇到了一个我无法解决的结果，并且与await（）的逻辑有点混淆。虽然结果似乎是我的预期，即SEND和ACK可选择10次。它实际上在SEND上运行了额外的时间，并且显然在第10次-ACK运行时将状态Sender.stop更改为true状态并没有“停止”Send-run（）中的while循环。另外，线程没有在10次（或11次）之后结束，因此我从未进入“它已经结束......”在main（）中打印出来。似乎这个过程挂在了某个地方。