CyclicBarrierDemo.java

package PracticeJavaHighConcurrency.chapter3;

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

/**
 * Created by 13 on 2017/5/4.
 */
public class CyclicBarrierDemo {
    public static class Soldier implements Runnable {
        private String soldier;
        private final CyclicBarrier cyclicBarrier;

        public Soldier(CyclicBarrier cyclicBarrier, String soldier) {
            this.soldier = soldier;
            this.cyclicBarrier = cyclicBarrier;
        }

        @Override
        public void run() {
            try {
                // 等待所有士兵到齐
                cyclicBarrier.await();
                doWork();
                // 等到所有士兵完成工作
                cyclicBarrier.await();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (BrokenBarrierException e) {
                e.printStackTrace();
            }

        }

        void doWork() {
            try {
                Thread.sleep(Math.abs(new Random().nextInt() % 10000));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(soldier + ": work done!");
        }
    }

    public static class BarrierRun implements Runnable {

        boolean flag;
        int N;

        public BarrierRun(boolean flag, int N) {
            this.flag = flag;
            this.N = N;
        }

        @Override
        public void run() {
            if (flag) {
                System.out.println("长官, 士兵" + N + "任务完成!");
            } else {
                System.out.println("长官, 士兵" + N + "到达指定地点!");
                flag = true;
            }
        }
    }


    public static void main(String args[]) {
        final int N = 10;
        Thread[] allSoldier = new Thread[N];
        boolean flag = false;
        CyclicBarrier cyclicBarrier = new CyclicBarrier(N, new BarrierRun(flag, N));
        System.out.println("长官:集合!");
        for (int i = 0; i < N; i++) {
            System.out.println("士兵" + i + "报道!");
            allSoldier[i] = new Thread(new Soldier(cyclicBarrier, "士兵" + i));
            allSoldier[i].start();
        }
    }
}