一切看起来都很好，但是当我运行时，结果如下:
Start Thread(1): Pro2
Start Thread(2): Pro1
Start Thread(1): Con1
Start Thread(2): Con2
Pro2 Produce: EWlmJdi2KK
Left:
Pro2:EWlmJdi2KK
---Left: 1---
Con2 Consume: EWlmJdi2KK
Left:
---Left: 0---
Pro2 Produce: Nx7QPyG7vs
Left:
Pro2:Nx7QPyG7vs
---Left: 1---
Pro2 Produce: xl85Zwr80a
Left: Pro2:Nx7QPyG7vs Pro2:xl85Zwr80a
---Left: 2---
在运行时间内始终是相同的生产者和消费者。
这是我的代码: Main.java:
package com.producer;
import org.apache.commons.lang3.RandomStringUtils;
public class Main {
public static void main(String[] args) {
ThreadSynchronized semaphore = new ThreadSynchronized();
ThreadSynchronized.Producer pro = semaphore.new Producer("1");
ThreadSynchronized.Consumer con = semaphore.new Consumer("2");
new Thread(pro, "Pro2").start();
new Thread(pro, "Pro1").start();
new Thread(con, "Con1").start();
new Thread(con, "Con2").start();
}
}
ThreadSynchronized.java:
package com.producer;
import java.util.LinkedList;
/**
* Created by SkyAo on 15/10/18.
*/
public class ThreadSynchronized {
private static int pid;
private static int cid;
public LinkedList<Item> items = new LinkedList<>();
private Item temp;
private int item;
private boolean flag = false;
class Producer implements Runnable {
private String name;
private int id;
public Producer(String name) {
this.name = name;
}
@Override
public void run() {
this.id = ++pid;
System.out.println("Start Thread(" + this.id + "): " + Thread.currentThread().getName());
while (true)
this.produce();
}
private synchronized void produce() {
try {
Thread.sleep((int)(Math.random()*5000)+3000);
if (items.size() < 5) {
items.add(new Item(this.id, Thread.currentThread().getName()));
temp = items.getLast();
System.out.println(temp.sourceName + " Produce: " + temp.semi);
System.out.println("Left: ");
for (Item item : items) {
System.out.println(item.sourceName + ":" + item.semi);
}
System.out.println("---Left: " + items.size() + "---");
} else {
super.wait();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
super.notifyAll();
}
}
}
class Consumer implements Runnable {
private String name;
private int id;
public Consumer(String name) {
this.name = name;
//this.id = ++cid;
}
@Override
public void run() {
this.id = ++cid;
System.out.println("Start Thread(" + this.id + "): " + Thread.currentThread().getName());
while (true)
this.consume();
}
private synchronized void consume() {
try {
Thread.sleep((int) (Math.random() * 5000) + 3000);
if (items.size() > 0) {
temp = items.removeFirst();
System.out.println(Thread.currentThread().getName() + " Consume: " + temp.semi);
System.out.println("Left: ");
for (Item item : items) {
System.out.println(item.sourceName + ":" + item.semi);
}
System.out.println("---Left: " + items.size() + "---");
} else {
super.wait();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
super.notifyAll();
}
}
}
}
我不知道发生了什么以及如何解决它，感谢您的帮助。
最佳答案
您以一种不寻常的方式构建了您的解决方案。通常，生产者和消费者本身并不同步，但对他们共享的资源的访问是同步的。
考虑这个例子。在这里，MyQueue 的实例是共享资源——它是具有同步方法的东西。生产者和消费者本身并不同步。
import java.util.LinkedList;
import java.util.List;
import java.util.Random;
class MyQueue {
private int capacity;
private List<Integer> queue = new LinkedList<>();
public MyQueue(int capacity) {
this.capacity = capacity;
}
public synchronized void enqueue(int item) throws InterruptedException {
while (queue.size() == this.capacity) {
wait();
}
System.out.println("Thread " + Thread.currentThread().getName() +
" producing " + item);
queue.add(item);
if (queue.size() == 1) {
notifyAll();
}
}
public synchronized int dequeue() throws InterruptedException {
int item;
while (queue.size() == 0) {
wait();
}
item = queue.remove(0);
System.out.println("Thread " + Thread.currentThread().getName() +
" consuming " + item);
if (queue.size() == (capacity - 1)) {
notifyAll();
}
return item;
}
}
public class ProducerConsumer {
private static class Producer implements Runnable {
private MyQueue queue;
private Random random = new Random();
public Producer(MyQueue queue) {
this.queue = queue;
}
public void run() {
try {
for (;;) {
queue.enqueue(random.nextInt());
Thread.sleep((int)(Math.random() * 3000) + 1000);
}
} catch (InterruptedException ex) {
System.out.println(Thread.currentThread().getName() +
" interrupted");
}
}
}
private static class Consumer implements Runnable {
private MyQueue queue;
public Consumer(MyQueue queue) {
this.queue = queue;
}
public void run() {
try {
for (;;) {
queue.dequeue();
Thread.sleep((int)(Math.random() * 5000) + 3000);
}
} catch (InterruptedException ex) {
System.out.println(Thread.currentThread().getName() +
" interrupted");
}
}
}
public static void main(String[] args) {
MyQueue queue = new MyQueue(10);
new Thread(new Producer(queue), "Producer 1").start();
new Thread(new Producer(queue), "Producer 2").start();
new Thread(new Consumer(queue), "Consumer 1").start();
new Thread(new Consumer(queue), "Consumer 2").start();
}
}
示例输出:
$ java ProducerConsumer
Thread Producer 1 producing 1380029295
Thread Consumer 1 consuming 1380029295
Thread Producer 2 producing 1449212482
Thread Consumer 2 consuming 1449212482
Thread Producer 2 producing -1845586946
Thread Producer 1 producing -1072820603
Thread Producer 1 producing 1224861300
Thread Producer 2 producing 507431251
Thread Consumer 2 consuming -1845586946
Thread Consumer 1 consuming -1072820603
Thread Producer 2 producing -1305630628
Thread Producer 1 producing 1413011254
Thread Producer 2 producing -222621018
Thread Consumer 2 consuming 1224861300
Thread Producer 1 producing -1628544536
Thread Consumer 1 consuming 507431251
关于java - 使用 Java(同步)的生产者/消费者模型，但始终运行相同的线程，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33195290/