import java.util.concurrent.BlockingQueue;
  import java.util.concurrent.LinkedBlockingQueue;
// 生產(chǎn)消費(fèi)者模型——阻塞隊(duì)列
public class Demo20 {
    public static void main(String[] args) {
        // 創(chuàng)建一個(gè)阻塞隊(duì)列來(lái)作為交易場(chǎng)所
        BlockingQueue<Integer> queue = new LinkedBlockingQueue<>(10);
        Thread t1 = new Thread(() -> {
            int count = 0;
            while(true) {
                try {
                    queue.put(count);
                    System.out.println("生產(chǎn)元素:" + count);
                    count++;
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });
        Thread t2 = new Thread(() -> {
            while(true) {
                while(true) {
                    try {
                        Integer n = queue.take();
                        System.out.println("消費(fèi)元素:" + n);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
        t1.start();
        t2.start();
    }
}

class MyBlockQueue {
    // 使用string類(lèi)型的數(shù)組來(lái)保存元素，我們假設(shè)這里只存string
    private String[] items = new String[1000];
    //head表示指向隊(duì)列的頭部
    volatile private int head = 0;
    volatile private int tail = 0;
    volatile private int size = 0; // size表示元素個(gè)數(shù)
    private Object locker = new Object();
    public void put(String elem) throws InterruptedException {
        synchronized(locker) {
            while(size >= items.length) {
                //隊(duì)列已滿
                locker.wait();
                //return;
            }
            items[tail] = elem;
            tail++;
            if(tail >= items.length) {
                tail = 0;
            }
            //tail++和下面的if判斷可以替換成tail = (tail + 1) % (items.length)
            //但是站在CPU的角度來(lái)看,其實(shí)還是簡(jiǎn)單的if判斷比較快
            size++;
            locker.notify(); // 用來(lái)喚醒隊(duì)列為空的阻塞情況
        }
    }
    //出隊(duì)列
    public String take() throws InterruptedException {
        synchronized(locker) {
            while(size == 0) {
                locker.wait();
            }
            String elem = items[head];
            head++;
            if(head >= items.length) {
                head = 0;
            }
            size--;
            //使用notify來(lái)喚醒隊(duì)列阻塞滿的情況
            locker.notify();
            return elem;
        }
    }
}
public class Demo21 {
    public static void main(String[] args) {
        // 創(chuàng)建兩個(gè)線程分別表示消費(fèi)者和生產(chǎn)者
        MyBlockQueue queue = new MyBlockQueue();
        Thread t1 = new Thread(() -> {
           int count = 0;
           while(true) {
               try {
                   queue.put(count + "");
                   System.out.println("生產(chǎn)元素: " + count);
                   count++;
               } catch (InterruptedException e) {
                   e.printStackTrace();
               }
           }
        });
        Thread t2 = new Thread(() -> {
            while(true) {
                try {
                    String count = queue.take();
                    System.out.println("消費(fèi)元素: " + count);
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
        });
        t1.start();
        t2.start();
    }
}