/**
 * This is description.
 * 面試題: 實(shí)現(xiàn)一個(gè)容器, 有兩個(gè)要求:
 * 1. add, size.
 * 2. 寫2個(gè)線程, 線程1添加10個(gè)元素到容器中, 線程2實(shí)現(xiàn)監(jiān)控元素個(gè)數(shù), 當(dāng)個(gè)數(shù)到達(dá)5個(gè)時(shí), 線程2給出提示并結(jié)束(線程2結(jié)束).
 * Container3利用wait和notify優(yōu)化Container2的while(true){...}死循環(huán).
 *
 * @author Chris Lee
 * @date 2019/3/16 9:59
 */
public class Container3 {
    volatile List<Object> list = new ArrayList<>(10);

    public void add(Object object) {
        list.add(object);
    }

    public int size() {
        return list.size();
    }

    public static void main(String[] args) {
        Container2 container1 = new Container2();
        Object lock = new Object();

        new Thread(() -> {
            synchronized (lock) {
                System.out.println("當(dāng)前線程名: " + Thread.currentThread().getName() + "啟動(dòng).");
                if (container1.size() != 5) {
                    try {
                        lock.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                System.out.println("當(dāng)前線程名: " + Thread.currentThread().getName() + "結(jié)束.");

            }

        }, "t2").start();

        try {
            TimeUnit.SECONDS.sleep(1);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        new Thread(() -> {
            synchronized (lock) {
                for (int i = 0; i < 10; i++) {
                    container1.add(new Object());
                    System.out.println("當(dāng)前線程名: " + Thread.currentThread().getName() + ", i = " + i);
                    if (container1.size() == 5) {
                        lock.notify();
                    }
                    try {
                        TimeUnit.SECONDS.sleep(1);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }, "t1").start();

    }
    /*
        當(dāng)前線程名: t2啟動(dòng).
        當(dāng)前線程名: t1, i = 0
        當(dāng)前線程名: t1, i = 1
        當(dāng)前線程名: t1, i = 2
        當(dāng)前線程名: t1, i = 3
        當(dāng)前線程名: t1, i = 4
        當(dāng)前線程名: t1, i = 5
        當(dāng)前線程名: t1, i = 6
        當(dāng)前線程名: t1, i = 7
        當(dāng)前線程名: t1, i = 8
        當(dāng)前線程名: t1, i = 9
        當(dāng)前線程名: t2結(jié)束.
     */

}

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資料:

1. 學(xué)習(xí)視頻: https://www.bilibili.com/video/av11076511/?p=1
2. 參考代碼: https://github.com/EduMoral/edu/tree/master/concurrent/src/yxxy
3. 我的代碼: https://github.com/ChrisLeejing/learn_concurrency.git