我尝试从其中一个教程中使用 CyclicBarrier 运行示例：当空打印机的队列为 3 时，服务人员应填充空打印机。但是当我运行代码时，似乎打印机在队列中填充了 2、3 或 4 个空打印机：
打印机 1 为空
打印机 12 为空
打印机 14 为空
打印机 13 为空
填充 [Printer1、Printer12、Printer14、Printer13]
打印机 2 为空
打印机 7 为空
填充 [打印机 2、打印机 7]
那么这个例子是错误的还是我对 CyclicBarrier 的理解？我认为队列应该正好是 3 个元素的大小。我应该在代码中添加什么来解决这个问题？提前致谢。
代码：
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.TimeUnit;
public class PrinterRecharger {
public static void main(String args[]) {
ServiceMan serviceMan = new ServiceMan(3);
for (int i = 0; i < 15; i++) {
new Thread(new Printer(serviceMan, "Printer" + (i + 1))).start();
}
}
}
class ServiceMan {
private CyclicBarrier queue;
private List<String> inQueue;
public ServiceMan(int hardWorking) {
inQueue = new ArrayList<String>();
queue = new CyclicBarrier(hardWorking, new Runnable() {
@Override
public void run() {
System.out.println("Filling " + inQueue);
inQueue.clear();
}
});
}
public void recharge(String name) {
try {
inQueue.add(name);
queue.await();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (BrokenBarrierException e) {
e.printStackTrace();
}
}
}
class Printer implements Runnable {
private String name;
private Random rand;
private ServiceMan serviceMan;
public Printer(ServiceMan serviceMan, String name) {
this.name = name;
this.serviceMan = serviceMan;
this.rand = new Random();
}
public void run() {
try {
while (true) {
TimeUnit.SECONDS.sleep(rand.nextInt(10));
System.out.println(name + " is empty");
serviceMan.recharge(name);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}