通过简单实现一个阻塞队列了解ReentraintLock

MyBlockingQueue 代码

 

package com.kms.test;

import java.util.LinkedList;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;

public class MyBlockingQueue<E> {

	LinkedList<E> list;
	int size; // 队列大小，可指定，默认为16
	
	ReentrantLock lock = new ReentrantLock(); // 可重入锁
	Condition nonFull = lock.newCondition(); // 非满条件
	Condition nonEmpty = lock.newCondition(); // 非空条件
	
	MyBlockingQueue(){
		this(16);
	}
	
	MyBlockingQueue(int size){
		this.size = size;
		this.list = new LinkedList();
	}
	
	public void enqueue(E e) throws InterruptedException{
		lock.lock();
		try{
			while(list.size() == size){
				System.out.println("队列已满，当前数量为: "+list.size());
				nonFull.await();
			}
			list.add(e);
			System.out.println("入队: "+e);
			nonEmpty.signal(); // 非空，唤醒在nonEmpty条件上等待的线程
		}finally{
			lock.unlock();
		}
	}
	
	public E dequeue() throws InterruptedException{
		lock.lock();
		try{
			while(list.size() == 0){
				System.out.println("队列为空");
				nonEmpty.await();
			}
			E e = list.pop();
			System.out.println("出队: "+e);
			nonFull.signal(); // 唤醒在nonFull条件上等待的线程
			return e;
		}finally{
			lock.unlock();
		}
	}

}

　　

简单测试类

 

package com.kms.test;

public class Test7 {

    static MyBlockingQueue queue = new MyBlockingQueue<Integer>();

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        
        new Thread(new Runnable(){

            @Override
            public void run() {
                // TODO Auto-generated method stub
                try {
                    Thread.sleep(3000);
                } catch (InterruptedException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
                for(int i = 0; i < 3; i++){
                    try {
                        queue.dequeue();
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            
        }).start();
        
        for(int i = 0; i < 20; i ++){
            try {
                queue.enqueue(new Integer(i));
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

}

 

运行结果