【操作系统】实现生产者消费者模型操作系统StevenL的博客-

最近在复习操作系统，随手写两种Java实现生产者消费者模型的方式
一、信号量

import java.util.Queue; import java.util.Random; import java.util.concurrent.ConcurrentLinkedQueue; import java.util.concurrent.Semaphore; class MessageQueue { private static final Semaphore FULL = new Semaphore(0); private static final Semaphore EMPTY = new Semaphore(10); // 初始队列为空 private static final Semaphore MUTEX = new Semaphore(1); // 互斥锁 private static final Random RAND_NUM_PRODUCER = new Random(System.currentTimeMillis()); private static final Queue<Integer> QUEUE = new ConcurrentLinkedQueue<>(); public void produce(){ try {             EMPTY.acquire();             MUTEX.acquire();             QUEUE.offer(RAND_NUM_PRODUCER.nextInt(100));             System.out.println("【生产】生产者：" + Thread.currentThread().getName() + "   当前队列：" + QUEUE.size()); } catch (InterruptedException e) {             e.printStackTrace(); }         FULL.release();         MUTEX.release(); } public void consume(){ try {             FULL.acquire();             MUTEX.acquire();             QUEUE.poll();             System.out.println("【消费】消费者：" + Thread.currentThread().getName() + "   当前队列：" + QUEUE.size()); } catch (InterruptedException e) {             e.printStackTrace(); }         EMPTY.release();         MUTEX.release(); } } 

二、Lock和Condition

import java.util.Queue; import java.util.Random; import java.util.concurrent.ConcurrentLinkedQueue; import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; class MessageQueue { private static final Lock LOCK = new ReentrantLock(); private static final Condition NOT_FULL = LOCK.newCondition(); private static final Condition NOT_EMPTY = LOCK.newCondition(); private static final int MAX_SIZE = 10; private static final Random RAND_NUM_PRODUCER = new Random(System.currentTimeMillis()); private static final Queue<Integer> QUEUE = new ConcurrentLinkedQueue<>(); public void produce() {         LOCK.lock(); try{ while(QUEUE.size() == MAX_SIZE){                 NOT_FULL.await(); }             QUEUE.offer(RAND_NUM_PRODUCER.nextInt(100));             System.out.println("【生产】生产者：" + Thread.currentThread().getName() + "   当前队列：" + QUEUE.size());             NOT_EMPTY.signalAll(); }catch (InterruptedException e){             e.printStackTrace(); }finally {             LOCK.unlock(); } } public void consume(){         LOCK.lock(); try{ while(QUEUE.size() == 0){                 NOT_EMPTY.await(); }             QUEUE.poll();             System.out.println("【消费】消费者：" + Thread.currentThread().getName() + "   当前队列：" + QUEUE.size());             NOT_FULL.signalAll(); }catch (InterruptedException e){             e.printStackTrace(); }finally {             LOCK.unlock(); } } } // 以下是测试代码 public class ProducerAndConsumer{ public static void main(String[] args) {         MessageQueue messageQueue = new MessageQueue();         Thread producer = new Thread(()->{ while(true) messageQueue.produce(); });         Thread consumer = new Thread(()->{ while(true) messageQueue.consume(); });         producer.start();         consumer.start(); } }