netty12---线程池简单源码

package com.cn;

import java.io.IOException;
import java.nio.channels.Selector;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.atomic.AtomicBoolean;

import com.cn.pool.NioSelectorRunnablePool;

/**
 * 抽象selector线程基类
 */
public abstract class AbstractNioSelector implements Runnable {

    /**
     * 线程池
     */
    private final Executor executor;

    /**
     * 选择器
     */
    protected Selector selector;

    /**
     * 选择器wakenUp状态标记
     */
    protected final AtomicBoolean wakenUp = new AtomicBoolean();

    /**
     * 线程安全任务队列
     */
    private final Queue<Runnable> taskQueue = new ConcurrentLinkedQueue<Runnable>();

    /**
     * 线程名称
     */
    private String threadName;

    /**
     * 线程池管理对象
     */
    protected NioSelectorRunnablePool selectorRunnablePool;

    AbstractNioSelector(Executor executor, String threadName, NioSelectorRunnablePool selectorRunnablePool) {
        this.executor = executor;
        this.threadName = threadName;
        this.selectorRunnablePool = selectorRunnablePool;
        openSelector();
    }

    /**
     * 获取selector并启动线程，一个线程拥有了select才能为多个客服服务。
     */
    private void openSelector() {
        try {
            this.selector = Selector.open();
        } catch (IOException e) {
            throw new RuntimeException("Failed to create a selector.");
        }
        executor.execute(this);//像线程池中加入一个任务，并执行任务的run方法。运行当前任务，执行run方法。从线程池拿出一个线程执行这个任务。
    }

    @Override
    public void run() {

        Thread.currentThread().setName(this.threadName);//给当前线程付一个名字

        while (true) {
            try {
                wakenUp.set(false);

                select(selector);//接口，执行NioServerBoss或者NioServerWorker的select方法

                processTaskQueue();//执行完任务队列里面的任务

                process(selector);//接口，执行NioServerBoss或者NioServerWorker的process方法
            } catch (Exception e) {
                // ignore
            }
        }

    }

    /**
     * 注册一个任务并激活selector
     *
     * @param task
     */
    protected final void registerTask(Runnable task) {
        taskQueue.add(task);

        Selector selector = this.selector;

        if (selector != null) {
            if (wakenUp.compareAndSet(false, true)) {//wakenUp是不是false,是false就置为true，
                selector.wakeup();
            }
        } else {
            taskQueue.remove(task);
        }
    }

    /**
     * 执行队列里的任务
     */
    private void processTaskQueue() {
        for (;;) {
            final Runnable task = taskQueue.poll();
            if (task == null) {
                break;
            }
            task.run();//task是runnable元素
        }
    }

    /**
     * 获取线程管理对象
     * @return
     */
    public NioSelectorRunnablePool getSelectorRunnablePool() {
        return selectorRunnablePool;
    }

    /**
     * select抽象方法
         子类有重写
     */
    protected abstract int select(Selector selector) throws IOException;

    /**
     * selector的业务处理
       子类有重写
     */
    protected abstract void process(Selector selector) throws IOException;

}

package com.cn;

import java.io.IOException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.Executor;

import com.cn.pool.Boss;
import com.cn.pool.NioSelectorRunnablePool;
import com.cn.pool.Worker;
/**
 * boss实现类，每一个NioServerBoss再一个线程里面
 */
public class NioServerBoss extends AbstractNioSelector implements Boss{

    public NioServerBoss(Executor executor, String threadName, NioSelectorRunnablePool selectorRunnablePool) {
        super(executor, threadName, selectorRunnablePool);
    }

    @Override
    protected void process(Selector selector) throws IOException {
        Set<SelectionKey> selectedKeys = selector.selectedKeys();
        if (selectedKeys.isEmpty()) {
            return;
        }

        for (Iterator<SelectionKey> i = selectedKeys.iterator(); i.hasNext();) {
            SelectionKey key = i.next();
            i.remove();
            ServerSocketChannel server = (ServerSocketChannel) key.channel();
            // 新客户端
            SocketChannel channel = server.accept();
            // 设置为非阻塞
            channel.configureBlocking(false);
            // 获取一个worker
            Worker nextworker = getSelectorRunnablePool().nextWorker();//通过线程管理对象获取一个worker（runnable任务对象），
            // 注册新客户端接入任务，将新的连接请求交给worker。
            nextworker.registerNewChannelTask(channel);//往别的任务队列里面加任务
            //安卓里面，子线程不能改变UI，要改变就要向主线程的任务队列里面加任务。

            System.out.println("新客户端链接");
        }
    }

    public void registerAcceptChannelTask(final ServerSocketChannel serverChannel){
         final Selector selector = this.selector;
         registerTask(new Runnable() {
            @Override
            public void run() {
                try {
                    //注册serverChannel到selector
                    serverChannel.register(selector, SelectionKey.OP_ACCEPT);
                } catch (ClosedChannelException e) {
                    e.printStackTrace();
                }
            }
        });
    }

    @Override
    protected int select(Selector selector) throws IOException {
        return selector.select();
    }
}

package com.cn;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.Executor;

import com.cn.pool.NioSelectorRunnablePool;
import com.cn.pool.Worker;
/**
 * worker实现类，每一个NioServerWorker再一个线程里面
 */
public class NioServerWorker extends AbstractNioSelector implements Worker{

    public NioServerWorker(Executor executor, String threadName, NioSelectorRunnablePool selectorRunnablePool) {
        super(executor, threadName, selectorRunnablePool);
    }

    @Override
    protected void process(Selector selector) throws IOException {
        Set<SelectionKey> selectedKeys = selector.selectedKeys();
        if (selectedKeys.isEmpty()) {
            return;
        }
        Iterator<SelectionKey> ite = this.selector.selectedKeys().iterator();
        while (ite.hasNext()) {
            SelectionKey key = (SelectionKey) ite.next();
            // 移除，防止重复处理
            ite.remove();

            // 得到事件发生的Socket通道
            SocketChannel channel = (SocketChannel) key.channel();

            // 数据总长度
            int ret = 0;
            boolean failure = true;
            ByteBuffer buffer = ByteBuffer.allocate(1024);
            //读取数据
            try {
                ret = channel.read(buffer);
                failure = false;
            } catch (Exception e) {
                // ignore
            }
            //判断是否连接已断开
            if (ret <= 0 || failure) {
                key.cancel();
                System.out.println("客户端断开连接");
            }else{
                 System.out.println("收到数据:" + new String(buffer.array()));

                 //回写数据
                 ByteBuffer outBuffer = ByteBuffer.wrap("收到\n".getBytes());
                 channel.write(outBuffer);// 将消息回送给客户端
            }
        }
    }

    /**
     * 加入一个新的socket客户端
     */
    public void registerNewChannelTask(final SocketChannel channel){
         final Selector selector = this.selector;
         registerTask(new Runnable() {
            @Override
            public void run() {
                try {
                    //将客户端注册到selector中
                    channel.register(selector, SelectionKey.OP_READ);
                } catch (ClosedChannelException e) {
                    e.printStackTrace();
                }
            }
        });
    }

    @Override
    protected int select(Selector selector) throws IOException {
        return selector.select(60000);
    }

}

package com.cn;

import java.net.SocketAddress;
import java.nio.channels.ServerSocketChannel;

import com.cn.pool.Boss;
import com.cn.pool.NioSelectorRunnablePool;
/**
 * 服务类
 */
public class ServerBootstrap {

private NioSelectorRunnablePool selectorRunnablePool;

    public ServerBootstrap(NioSelectorRunnablePool selectorRunnablePool) {
        this.selectorRunnablePool = selectorRunnablePool;
    }

    /**
     * 监听端口
     * @param localAddress
     */
    public void bind(final SocketAddress localAddress){
        try {
            // 获得一个ServerSocket通道
            ServerSocketChannel serverChannel = ServerSocketChannel.open();
            // 设置通道为非阻塞
            serverChannel.configureBlocking(false);
            // 将该通道对应的ServerSocket绑定到port端口
            serverChannel.socket().bind(localAddress);

            //获取一个boss线程
            Boss nextBoss = selectorRunnablePool.nextBoss();
            //向boss注册一个ServerSocket通道
            nextBoss.registerAcceptChannelTask(serverChannel);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

package com.cn;

import java.net.InetSocketAddress;
import java.util.concurrent.Executors;
import com.cn.pool.NioSelectorRunnablePool;
/**
 * 启动函数
 */
public class Start {

    public static void main(String[] args) {

        //管理线程池的，初始化2个线程池，一个boss一个work，
        NioSelectorRunnablePool nioSelectorRunnablePool = new NioSelectorRunnablePool(Executors.newCachedThreadPool(), Executors.newCachedThreadPool());

        //获取服务类
        ServerBootstrap bootstrap = new ServerBootstrap(nioSelectorRunnablePool);

        //绑定端口
        bootstrap.bind(new InetSocketAddress(10101));

        System.out.println("start");
    }

}

package com.cn.pool;

import java.nio.channels.ServerSocketChannel;
/**
 * boss接口
 */
public interface Boss {

    /**
     * 加入一个新的ServerSocket，监听连接
     */
    public void registerAcceptChannelTask(ServerSocketChannel serverChannel);
}

package com.cn.pool;

import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
import com.cn.NioServerBoss;
import com.cn.NioServerWorker;
/**
 * selector线程管理者
 *
 *   线程池是有多个线程，每个线程里面有一个任务队列，线程run的时候会从任务队列取一个任务出来，执行任务的run方法，
          队列里面没有任务就阻塞等待新的任务进来。
 */
public class NioSelectorRunnablePool {

    /**
     * boss任务数组，boss用来监听端口的，
     */
    private final AtomicInteger bossIndex = new AtomicInteger();
    private Boss[] bosses;

    /**
     * worker任务数组，用来处理事件的，
     */
    private final AtomicInteger workerIndex = new AtomicInteger();
    private Worker[] workeres;

    //boss和worker是一个线程池
    public NioSelectorRunnablePool(Executor boss, Executor worker) {
        initBoss(boss, 1);//boss是一个线程池。
        initWorker(worker, Runtime.getRuntime().availableProcessors() * 2);
    }

    /**
     * 初始化boss线程池的runable任务数组
     * @param boss
     * @param count
     */
    private void initBoss(Executor boss, int count) {
        this.bosses = new NioServerBoss[count];
        //this.bosses是一个数组，里面是一个个的NioServerBoss，
        //NioServerBoss是runnable任务对象。runnable对象里面有线程池、选择器、线程名、线程管理者。
        //executor.execute(this);通过NioServerBoss里面的线程池把任务对象NioServerBoss自己运行起来。
        //所有的NioServerBoss任务对象都是通过boss线程池来调度的。
        for (int i = 0; i < bosses.length; i++) {
            bosses[i] = new NioServerBoss(boss, "boss thread " + (i+1), this);//this是NioSelectorRunnablePool线程池管理者。
            //boss thread 是任务runable的名字
        }
    }

    /**
     * 初始化worker线程池的runable任务数组
     * @param worker
     * @param count
     */
    private void initWorker(Executor worker, int count) {
        this.workeres = new NioServerWorker[2/*count*/];
        for (int i = 0; i < workeres.length; i++) {
            //所有的NioServerWorker任务对象都是通过worker线程池来调度的。
            workeres[i] = new NioServerWorker(worker, "worker thread " + (i+1), this);
        }
        //boss线程池里面有8个NioServerBoss.runable对象（8个大任务，开了8个线程），
        //每一个NioServerWorker再一个线程里面。8个NioServerBoss.runable对象一开始就去run，
        //每个NioServerBoss.runable对象里面有一个任务队列taskQueue，队列里面是一个个的Runnable对象。

        /*
        public static void main(String[] args) {
        //创建一个线程池，可回收的，没任务就回收了。newCachedThreadPool可以很大。60秒没任务就回收。
        ExecutorService pool = Executors.newCachedThreadPool();//线程池
        for(int i = 1; i < 5; i++){//4个任务，一个任务就是一个Runnable
            pool.execute(new Runnable() {//没有返回值
                @Override
                public void run() {
                    try {
                        Thread.sleep(5);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println("thread name: " + Thread.currentThread().getName());

                }
            });
            try {
                Thread.sleep(5);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        pool.shutdown();//任务执行完就关了。
        /*thread name: pool-1-thread-1
        thread name: pool-1-thread-2
        thread name: pool-1-thread-1
        thread name: pool-1-thread-2   线程执行完了会回收，不一定开4个线程*/
    }

    /**
     * 获取一个worker的runable任务,给每个work平均分配
     */
    public Worker nextWorker() {
         return workeres[Math.abs(workerIndex.getAndIncrement() % workeres.length)];
    }

    /**
     * 获取一个boss的runable任务
     */
    public Boss nextBoss() {
         return bosses[Math.abs(bossIndex.getAndIncrement() % bosses.length)];
    }
}

package com.cn.pool;

import java.nio.channels.SocketChannel;
/**
 * worker接口
 */
public interface Worker {

    /**
     * 加入一个新的客户端会话，监听客户端的处理
     */
    public void registerNewChannelTask(SocketChannel channel);

}