java多线程之CyclicBarrier
public class CyclicBarrierTest {
public static void main(String[] args) {
ThreadPoolExecutor poolExe = new ThreadPoolExecutor(100, 1000, 1, TimeUnit.SECONDS,
new LinkedBlockingDeque<Runnable>(100));
int count = 2;
// 考试开始铃声响起,考试开始
final CyclicBarrier student = new CyclicBarrier(count+1);
for (int i = 0; i < count; i++) {
Runnable runnable = new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
try {
System.out.println("考生" + Thread.currentThread().getName() + "在等待考试开始的铃声响起");
student.await();
System.out.println("考生听到铃声" + Thread.currentThread().getName() + "开始答题");
Thread.sleep((long) (Math.random() * 100));// 答题过程,真正的业务逻辑处理部分
System.out.println("考生" + Thread.currentThread().getName() + "交卷");
student.await();
} catch (Exception e) {
e.printStackTrace();
}
}
};
poolExe.execute(runnable); // 运动员开始任务
}
try {
// 答题时间
Thread.sleep((long) (Math.random() * 1000));
System.out.println("考场" + Thread.currentThread().getName() + "开始铃声即将响起");
student.await();
System.out.println("考场" + Thread.currentThread().getName() + "考试开始铃声响起");
student.await(); // 所有考生交卷
System.out.println("考场" + Thread.currentThread().getName() + "考试结束");
} catch (Exception e) {
e.printStackTrace();
}
poolExe.shutdown();
}
}
为什么会先执行/在等待考试开始的铃声响起 而不是 开始铃声即将响起
求大神解析