ArrayBlockingQueue和LinkedBlockingQueue的区别

1.    队列中锁的实现不同

       ArrayBlockingQueue实现的队列中的锁是没有分离的，即生产和消费用的是同一个锁；

       LinkedBlockingQueue实现的队列中的锁是分离的，即生产用的是putLock，消费是takeLock

   
2.    在生产或消费时操作不同

       ArrayBlockingQueue实现的队列中在生产和消费的时候，是直接将枚举对象插入或移除的；

       LinkedBlockingQueue实现的队列中在生产和消费的时候，需要把枚举对象转换为Node<E>进行插入或移除，会影响性能

3.    队列大小初始化方式不同

       ArrayBlockingQueue实现的队列中必须指定队列的大小；

       LinkedBlockingQueue实现的队列中可以不指定队列的大小，但是默认是Integer.MAX_VALUE

   

注意:

1.    在使用LinkedBlockingQueue时，若用默认大小且当生产速度大于消费速度时候，有可能会内存溢出

2.    在使用ArrayBlockingQueue和LinkedBlockingQueue分别对1000000个简单字符做入队操作时，

       LinkedBlockingQueue的消耗是ArrayBlockingQueue消耗的10倍左右，
       即LinkedBlockingQueue消耗在1500毫秒左右，而ArrayBlockingQueue只需150毫秒左右。

ArrayBlockingQueue

final ReentrantLock lock;

LinkedBlockingQueue

/** Lock held by take, poll, etc */
private final ReentrantLock takeLock = new ReentrantLock();
/** Lock held by put, offer, etc */
private final ReentrantLock putLock = new ReentrantLock();

public class BlockingQueueLC<T> {
private List queue = new LinkedList<>();
private final int limit;
Lock lock = new ReentrantLock();
private Condition needNotEmpty = lock.newCondition();//不为空
private Condition needNotFull = lock.newCondition();//不为满

public BlockingQueueLC(int limit) {
this.limit = limit;
}

public void enqueue(T item) throws InterruptedException {
lock.lock();
try{
while(this.queue.size()==this.limit){
needNotFull.await();//1
}
this.queue.add(item);
needNotEmpty.signal();//2
}finally{
lock.unlock();
}
}

public  T dequeue() throws InterruptedException {
lock.lock();
try{
while(this.queue.size()==0){
needNotEmpty.await();//2
}
needNotFull.signal();//1
return (T) this.queue.remove(0);
}finally{
lock.unlock();
}
}
}

生产者消费者

package com.dongnaoedu;

/**
* Created by BF100 on 2018/1/30.
*/

import java.lang.Thread;

public class MyProducerComsumer {
private MyBlockingQueue queue = new MyBlockingQueue(3);
//    private BlockingQueue queue = new LinkedBlockingDeque(3);

class Car {
private String name;
private String price;

public Car(String name, String price) {
this.name = name;
this.price = price;
}
}

class Producer extends Thread {
@Override
public void run() {
while (true) {
try {
Car car = new Car("宝马", "888888");
queue.put(car);
System.err.println("生产者生产====" + car.toString());
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

class Comsumer extends Thread {
@Override
public void run() {
while (true) {
//                try {
Car car = (Car) queue.take();
System.err.println("消费者购买汽车" + car.toString());
//                } catch (Exception e) {
//                    e.printStackTrace();
//                }
}
}
}

public static void main(String[] args) {
MyProducerComsumer myProducerComsumer = new MyProducerComsumer();
Producer producer1 = myProducerComsumer.new Producer();
Producer producer2 = myProducerComsumer.new Producer();
Comsumer comsumer = myProducerComsumer.new Comsumer();
producer1.start();
producer2.start();
comsumer.start();
}

}