package concurrent;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
/**
 * 面試題：實現一個容器，提供兩個方法，一個size,一個add
 * 		寫兩個執行緒，執行緒1往自定義容器中新增十個元素，執行緒2實時監控容器中的數量，
 * 		在容器中元素個數為5的時候輸出並結束執行緒
 * 使用門閂，門閂初始為1，當變為0的時候門閂開啟，執行緒2就受到了通知，輸出並結束
 * @author BarryLee
 * @2018年11月6日@下午12:49:52
 */
public class TestCountDowmLauch {
	volatile List<Object> list = new ArrayList<>();
	void add(Object o) {
		list.add(o);
	}
	int size() {
		return list.size();
	}
	public static void main(String[] args) {
		CountDownLatch latch = new CountDownLatch(1);//
		TestCountDowmLauch container = new TestCountDowmLauch();// 自定義的容器
		new Thread(new Runnable() {
			@Override
			public void run() {
				if (container.size() != 5) {
					try {
						latch.await();
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
				System.out.println("thread2 - end");
			}
		}).start();

		new Thread(new Runnable() {
			@Override
			public void run() {
				for (int i = 0; i < 10; i++) {
					if (container.size() == 5) {
						latch.countDown();
					}
					try {
						TimeUnit.SECONDS.sleep(1);
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
					System.out.println("thread1 - add");
					container.add(new Object());
				}
			}
		}).start();
	}
}
/*
thread1 - add
thread1 - add
thread1 - add
thread1 - add
thread1 - add
thread2 - end
thread1 - add
thread1 - add
thread1 - add
thread1 - add
thread1 - add
*/