java 多线程 java 中多线程生产者消费者问题仔细讲解

import java.util.concurrent.locks.*;

class BoundedBuffer {
  final Lock lock = new ReentrantLock();//对象锁
  final Condition notFull = lock.newCondition(); //生产者监视器
  final Condition notEmpty = lock.newCondition(); //消费者监视器

  //资源对象
  final Object[] items = new Object[10];
  //putptr生产者角标，takeptr消费者角标，count计数器(容器的实际长度)
  int putptr, takeptr, count;

  public void put(Object x) throws InterruptedException {
    //生产者拿到锁
   lock.lock();
   try {
     //当实际长度不满足容器的长度
    while (count == items.length) 
      //生产者等待
     notFull.await();
    //把生产者产生对象加入容器
    items[putptr] = x; 
    System.out.println(Thread.currentThread().getName()+"   put-----------"+count);
    Thread.sleep(1000);
    //如果容器的实际长==容器的长，生产者角标置为0
    if (++putptr == items.length) putptr = 0;
    ++count;
    //唤醒消费者
    notEmpty.signal();
   } finally {
     //释放锁
    lock.unlock();
   }
  }

  public Object take() throws InterruptedException {
   lock.lock();
   try {
    while (count == 0) 
      //消费者等待
     notEmpty.await();
    Object x = items[takeptr]; 
    System.out.println(Thread.currentThread().getName()+"   get-----------"+count);
    Thread.sleep(1000);
    if (++takeptr == items.length) takeptr = 0;
    --count;
    //唤醒生产者
    notFull.signal();
    return x;
   } finally {
     //释放锁
    lock.unlock();
   }
  } 
 }

class Consu implements Runnable{
  BoundedBuffer bbuf;

  public Consu(BoundedBuffer bbuf) {
    super();
    this.bbuf = bbuf;
  }

  @Override
  public void run() {
    while(true){
    try {
      bbuf.take() ;
    } catch (InterruptedException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    }
  }

}
class Produ implements Runnable{
  BoundedBuffer bbuf;
  int i=0;
  public Produ(BoundedBuffer bbuf) {
    super();
    this.bbuf = bbuf;
  }

  @Override
  public void run() {
    while(true){
      try {
        bbuf.put(new String(""+i++)) ;
      } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
  }

}



//主方法
class Lock1{
  public static void main(String[] args) {
    BoundedBuffer bbuf=new BoundedBuffer();
    Consu c=new Consu(bbuf);
    Produ p=new Produ(bbuf);
    Thread t1=new Thread(p);
    Thread t2=new Thread(c);
    t1.start();
    t2.start();
    Thread t3=new Thread(p);
    Thread t4=new Thread(c);
    t3.start();
    t4.start();
  }
}