package com.tl.skyLine.thread;
import java.util.concurrent.ArrayBlockingQueue;
/**
 * Created by tl on 17/3/3.
 */
public class BlockingQueueTest {
  //final成员变量表示常量，只能被赋值一次，赋值后值不再改变。
  private static final int queueSize = 5;
  private static final ArrayBlockingQueue<String> queue = new ArrayBlockingQueue<String>(queueSize);
  private static final int produceSpeed = 2000;//生产速度(越小越快)
  private static final int consumeSpeed = 10;//消费速度(越小越快)
  //生产者
  public static class Producer implements Runnable {
    @Override
    public void run() {
      while (true) {
        try {
          System.out.println("老板准备炸油条了，架子上还能放：" + (queueSize - queue.size()) + "根油条");
          queue.put("1根油条");
          System.out.println("老板炸好了1根油条，架子上还能放：" + (queueSize - queue.size()) + "根油条");
          Thread.sleep(produceSpeed);
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
    }
  }
  //消费者
  public static class Consumer implements Runnable {
    @Override
    public void run() {
      while (true) {
        try {
          System.out.println("A 准备买油条了，架子上还剩" + queue.size() + "根油条");
          queue.take();
          System.out.println("A 买到1根油条，架子上还剩" + queue.size() + "根油条");
          Thread.sleep(consumeSpeed);
          System.out.println("B 准备买油条了，架子上还剩" + queue.size() + "根油条");
          queue.take();
          System.out.println("B 买到1根油条，架子上还剩" + queue.size() + "根油条");
          Thread.sleep(consumeSpeed);
          System.out.println("C 准备买油条了，架子上还剩" + queue.size() + "根油条");
          queue.take();
          System.out.println("C 买到1根油条，架子上还剩" + queue.size() + "根油条");
          Thread.sleep(consumeSpeed);
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
    }
  }
  public static void main(String[] args) {
    Thread producer = new Thread(new Producer());
    Thread consumer = new Thread(new Consumer());
    producer.start();
    consumer.start();
  }
}

老板准备炸油条了，架子上还能放：5根油条
老板炸好了1根油条，架子上还能放：4根油条
A 准备买油条了，架子上还剩1根油条
A 买到1根油条，架子上还剩0根油条
B 准备买油条了，架子上还剩0根油条
老板准备炸油条了，架子上还能放：5根油条
老板炸好了1根油条，架子上还能放：4根油条
B 买到1根油条，架子上还剩0根油条
C 准备买油条了，架子上还剩0根油条
老板准备炸油条了，架子上还能放：5根油条
老板炸好了1根油条，架子上还能放：4根油条
C 买到1根油条，架子上还剩0根油条
A 准备买油条了，架子上还剩0根油条
老板准备炸油条了，架子上还能放：5根油条
老板炸好了1根油条，架子上还能放：4根油条
A 买到1根油条，架子上还剩0根油条
B 准备买油条了，架子上还剩0根油条
老板准备炸油条了，架子上还能放：5根油条
老板炸好了1根油条，架子上还能放：4根油条

public class BlockingQueue {
 private List queue = new LinkedList();
 private int limit = 10;
 public BlockingQueue(int limit){
  this.limit = limit;
 }
 public synchronized void enqueue(Object item)
 throws InterruptedException {
  while(this.queue.size() == this.limit) {
   wait();
  }
  if(this.queue.size() == 0) {
   notifyAll();
  }
  this.queue.add(item);
 }
 public synchronized Object dequeue()
 throws InterruptedException{
  while(this.queue.size() == 0){
   wait();
  }
  if(this.queue.size() == this.limit){
   notifyAll();
  }
  return this.queue.remove(0);
 }
}

/** Main lock guarding all access */ 
final ReentrantLock lock; 
/** Condition for waiting takes */ 
private final Condition notEmpty; 
/** Condition for waiting puts */ 
private final Condition notFull; 

public void put(E e) throws InterruptedException {
  checkNotNull(e);
  final ReentrantLock lock = this.lock;
  lock.lockInterruptibly();
  try {
    while (count == items.length)
      notFull.await();
    enqueue(e);
  } finally {
    lock.unlock();
  }
}

public E take() throws InterruptedException {
  final ReentrantLock lock = this.lock;
  lock.lockInterruptibly();
  try {
    while (count == 0)
      notEmpty.await();
    return dequeue();
  } finally {
    lock.unlock();
  }
}

private E dequeue() {
  // assert lock.getHoldCount() == 1;
  // assert items[takeIndex] != null;
  final Object[] items = this.items;
  @SuppressWarnings("unchecked")
  E x = (E) items[takeIndex];
  items[takeIndex] = null;
  if (++takeIndex == items.length)
    takeIndex = 0;
  count--;
  if (itrs != null)
    itrs.elementDequeued();
  notFull.signal();
  return x;
}