import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * 面试题：写一个固定容量的同步容器，实现get和put方法，并实现getCount方法，
 * 能够支持2个生产者线程和10个消费者线程之间的阻塞调用
 * 使用ReentrantLock实现
 */
public class ThreadTest2_Lock {
    static List lists = new CopyOnWriteArrayList();
    final Lock lock = new ReentrantLock();

    final Condition proLock = lock.newCondition();
    final Condition conLock = lock.newCondition();

    public void put(Object o) {
        try{
            lock.lock();
            while(lists.size() == 2){
                //生产者等待
                proLock.await();
            }
            lists.add(o);
            System.out.println("生产者：" + Thread.currentThread().getName() + "生产商品");
            //通知消费者消费
            conLock.signalAll();
        }catch (InterruptedException e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }

    public Object get() {
        try{
            lock.lock();
            while(lists.size() == 0){
                //生产者等待
                conLock.await();
            }
            Object o = lists.remove(0);
            System.out.println("消费者：" + Thread.currentThread().getName() + "消费商品");
            //通知生产者
            proLock.signalAll();
            return o;
        }catch (InterruptedException e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
        return null;
    }

    public int getCount() {
        return lists.size();
    }

    public static void main(String[] args) {
        ThreadTest2_Lock test2 = new ThreadTest2_Lock();
        //准备2个生产线程
        for (int i = 0; i < 2; i++) {
            new Thread(() -> {
                for (int j = 0; j < 5; j++) {
                    test2.put(new Object());
                }
            }, "pro" + i).start();
        }
        //准备10个消费线程
        for (int i = 0; i < 10; i++) {
            new Thread(() -> {
                for (int j = 0; j < 5; j++) {
                    test2.get();
                }
            }, "con" + i).start();
        }
    }
}