Work Thread Design Pattern

模拟传送带工作模式

Channel 传送带

package com.dwz.concurrency2.chapter18;

import java.util.Arrays;
/**
 *    传送带
 */
public class Channel {
    private final static int MAX_REQUEST = 100;
    
    private final Request[] requestQueue;
    
    private int head;
    
    private int tail;
    
    private int count;
    
    private final WorkerThread[]  workerPool;
    
    public Channel(int workers) {
        this.requestQueue = new Request[MAX_REQUEST];
        this.head = 0;
        this.tail = 0;
        this.count = 0;
        this.workerPool = new WorkerThread[workers];
        this.init();
    }

    private void init() {
        for(int i = 0; i < workerPool.length; i++) {
            workerPool[i] = new WorkerThread("Worker-" + i, this);
        }
    }
    
    /**
     * push switch to start all of worker to work.
     */
    public void startWorker() {
        Arrays.asList(workerPool).forEach(WorkerThread::start);
    }
    
    public synchronized void put(Request request) {
        while (count >= requestQueue.length) {
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        
        this.requestQueue[tail] = request;
        this.tail = (tail + 1) % this.requestQueue.length;
        this.count++;
        this.notifyAll();
    }
    
    public synchronized Request take() {
        while (count <= 0) {
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        
        Request request = this.requestQueue[head];
        this.head = (this.head + 1) % this.requestQueue.length;
        this.count--;
        this.notifyAll();
        return request;
    }
}

Request 商品

package com.dwz.concurrency2.chapter18;
/**
 * 商品
 */
public class Request {
    private final String name;
    private final int number;
    
    public Request(String name, int number) {
        this.name = name;
        this.number = number;
    }
    
    public void execute() {
        System.out.println(Thread.currentThread().getName() + " executed " + this);
    }
    
    @Override
    public String toString() {
        return "Request=> No." + number + ", Name=>" + name;
    }
    
}

TransportThread 向传送带上搬运线程

package com.dwz.concurrency2.chapter18;

import java.util.Random;
/**
 * 向传送带上搬运
 */
public class TransportThread extends Thread {
    private final Channel channel;
    
    private static final Random random = new Random(System.currentTimeMillis());

    public TransportThread(String name, Channel channel) {
        super(name);
        this.channel = channel;
    }
    
    @Override
    public void run() {
        try {
            for(int i = 0; true; i++) {
                Request request = new Request(getName(), i);
                this.channel.put(request);
                Thread.sleep(random.nextInt(1000));
            }
        } catch (Exception e) {
        }
    }
}

WorkerThread 从传送带上带走的线程

package com.dwz.concurrency2.chapter18;

import java.util.Random;
/**
 *    从传送带上带走
 */
public class WorkerThread extends Thread {
    private final Channel channel;
    
    private static final Random random = new Random(System.currentTimeMillis());
    
    public WorkerThread(String name, Channel channel) {
        super(name);
        this.channel = channel;
    }
    
    @Override
    public void run() {
        while (true) {
            channel.take().execute();
            try {
                Thread.sleep(random.nextInt(1000));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

测试

package com.dwz.concurrency2.chapter18;

public class WorkerClient {
    public static void main(String[] args) {
        Channel channel = new Channel(5);
        channel.startWorker();
        
        new TransportThread("Alex", channel).start();
        new TransportThread("Jack", channel).start();
        new TransportThread("William", channel).start();
    }
}