TransferQueue实例

时间 2019-11-07

标签 transferqueue 实例繁體版

原文原文链接

序

本文主要简介一下TransferQueue。html

TransferQueue

TransferQueue(java7引入)继承了BlockingQueue（BlockingQueue又继承了Queue）并扩展了一些新方法。生产者会一直阻塞直到所添加到队列的元素被某一个消费者所消费（不单单是添加到队列里就完事）。java

LinkedTransferQueue

LinkedTransferQueue其实是ConcurrentLinkedQueue、SynchronousQueue（公平模式）和LinkedBlockingQueue的超集。并且LinkedTransferQueue更好用，由于它不单单综合了这几个类的功能，同时也提供了更高效的实现。ide

对比SynchronousQueue

SynchronousQueue使用两个队列（一个用于正在等待的生产者、另外一个用于正在等待的消费者）和一个用来保护两个队列的锁。而LinkedTransferQueue使用CAS操做实现一个非阻塞的方法，这是避免序列化处理任务的关键。ui

使用场景

当咱们不想生产者过分生产消息时，TransferQueue可能很是有用，可避免发生OutOfMemory错误。在这样的设计中，消费者的消费能力将决定生产者产生消息的速度。.net

实例

public class LinkedTransferQueueDemo {
    static LinkedTransferQueue<String> lnkTransQueue = new LinkedTransferQueue<String>();
    public static void main(String[] args) {
        ExecutorService exService = Executors.newFixedThreadPool(2);
        Producer producer = new LinkedTransferQueueDemo().new Producer();
        Consumer consumer = new LinkedTransferQueueDemo().new Consumer();
        exService.execute(producer);
        exService.execute(consumer);
        exService.shutdown();
    }
    class Producer implements Runnable{
        @Override
        public void run() {
            for(int i=0;i<3;i++){
                try {
                    System.out.println("Producer is waiting to transfer...");
                    lnkTransQueue.transfer("A"+i);
                    System.out.println("producer transfered element: A"+i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    class Consumer implements Runnable{
        @Override
        public void run() {
            for(int i=0;i<3;i++){
                try {
                    System.out.println("Consumer is waiting to take element...");
                    String s= lnkTransQueue.take();
                    System.out.println("Consumer received Element: "+s);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

输出设计

Producer is waiting to transfer...
Consumer is waiting to take element...
producer transfered element: A0
Producer is waiting to transfer...
Consumer received Element: A0
Consumer is waiting to take element...
producer transfered element: A1
Producer is waiting to transfer...
Consumer received Element: A1
Consumer is waiting to take element...
Consumer received Element: A2
producer transfered element: A2

TransferQueue实例

序

TransferQueue

LinkedTransferQueue

对比SynchronousQueue

使用场景

实例

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