【Java多线程二】多路条件解决生产者消费者问题

Java  /  管理员 发布于 3年前   169

package com.tom;import java.util.LinkedList;import java.util.Queue;import java.util.concurrent.ThreadLocalRandom;import java.util.concurrent.locks.Condition;import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;class Plate<T> {    private final Lock lock = new ReentrantLock();    private final Condition PLATE_NOT_FULL = lock.newCondition();    private final Condition PLATE_NOT_EMPTY = lock.newCondition();    private final Queue<T> plates = new LinkedList<T>();    private int size;    public Plate(int size) {        this.size = size;    }    public void produce(T fruit) {        lock.lock();        try {            if (plates.size() >= size) {                try {                    System.out.println(Thread.currentThread().getName() + ", The plate is full..waiting to put into the plate");                    PLATE_NOT_FULL.await();                } catch (InterruptedException e) {                    e.printStackTrace();                }            }            System.out.println(Thread.currentThread().getName() + ", The plate is not full..put the fruit  into the plate: " + fruit);            plates.offer(fruit);            PLATE_NOT_EMPTY.signalAll();        } finally {            if (lock != null){                lock.unlock();            }        }    }    public T consume() {        T fruit = null;        lock.lock();        try {            if (plates.isEmpty()) {                try {                    System.out.println(Thread.currentThread().getName() + ", The plate is empty..waiting to consume");                    PLATE_NOT_EMPTY.await();                } catch (InterruptedException e) {                    e.printStackTrace();                }            }            fruit = plates.poll();            System.out.println(Thread.currentThread().getName() + ",The plate is not empty, consume the fruit: " + fruit);            PLATE_NOT_FULL.signalAll();        } finally {            if (lock != null){                lock.unlock();            }        }        return fruit;    }}public class ThreadCommunication {    private static volatile boolean shutdown = false;    public static void main(String[] args) {        final Plate<Integer> plate = new Plate<Integer>(8);        Thread[] consumers = new Thread[3];        for (int i = 0; i < consumers.length; i++) {            consumers[i] = new Thread() {                @Override                public void run() {                    while (!shutdown) {                        plate.consume();                        try {                            Thread.sleep(200);                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    }                }            };            consumers[i].start();        }        Thread[] producers = new Thread[2];        for (int i = 0; i < producers.length; i++) {            producers[i] = new Thread() {                @Override                public void run() {                    while (!shutdown) {                        plate.produce(ThreadLocalRandom.current().nextInt(100, 1000));                        try {                            Thread.sleep(100);                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    }                }            };            producers[i].start();        }        try {            Thread.sleep(6000);            shutdown = true;        } catch (InterruptedException e) {            e.printStackTrace();        }    }}