package com.expgiga.JUC;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
/**
 * 生產(chǎn)者消費者案例
 */
public class TestProductorAndConsumerForLock {
  public static void main(String[] args) {
    Clerk clerk = new Clerk();
    Productor productor = new Productor(clerk);
    Consumer consumer = new Consumer(clerk);
    new Thread(productor, "生產(chǎn)者A").start();
    new Thread(consumer, "消費者B").start();
    new Thread(productor, "生產(chǎn)者C").start();
    new Thread(consumer, "消費者D").start();
  }
}
//店員
class Clerk {
  private int product = 0;
  private Lock lock = new ReentrantLock();
  private Condition condition = lock.newCondition();
  //進貨方法
  public void get() {
    lock.lock();
    try {
      while (product >= 1) { //為了避免虛假喚醒，應該總是使用在循環(huán)中
        System.out.println("產(chǎn)品已滿！");
        try {
          condition.await();
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
      System.out.println(Thread.currentThread().getName() + " : " + ++product);
      condition.signalAll();
    } finally {
      lock.unlock();
    }
  }
  //賣貨方法
  public void sale() {
    lock.lock();
    try {
      while (product <= 0) {
        System.out.println("產(chǎn)品缺貨！");
        try {
          condition.await();
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
      System.out.println(Thread.currentThread().getName() + " : " + --product);
      condition.signalAll();
    } finally {
      lock.unlock();
    }
  }
}
//生產(chǎn)者
class Productor implements Runnable {
  private Clerk clerk;
  public Productor(Clerk clerk) {
    this.clerk = clerk;
  }
  @Override
  public void run() {
    for (int i = 0; i < 20; i++) {
      try {
        Thread.sleep(200);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
      clerk.get();
    }
  }
}
//消費者
class Consumer implements Runnable {
  private Clerk clerk;
  public Consumer(Clerk clerk) {
    this.clerk = clerk;
  }
  @Override
  public void run() {
    for (int i = 0; i < 20; i++) {
      clerk.sale();
    }
  }
}