京东多线程编排框架AsyncTool-筱晶IT知识库

并行框架的使用背景

经常会有这样的调用场景:app(或web前端)调用后台的一个接口，该接口接到该请求后，需要调用其他多个微服务来获取数据，最终汇总一个最终结果返回给用户。

整如用户请求我的订单”，后台在收到请求后，就需要去调用用户详情RPC、商品详情RPC、库存RPC，优惠券等等很多个服务。有些服务是可以并行去请求的，但有些服务是依赖于某个服务的返回值的(如查库存、优惠券，就依赖于商品详情回复到达后才能去请求)。

CompleteableFuture VS AsyncTool

CompleteableFuture大家都用过，里面有supply、then、combine、allOf等等方法，都可以用来接收一个任务，最终将多个任务汇总成一个结果。

但有一个问题，你supply一个任务后，这个任务就黑盒了。如果你编排了很多个任务，每一个任务的执行情况，执行到哪一步了，每一步的执行结果情况，我们是不知道的。只能等它最终执行完毕后，最后汇总结果。

一个并行框架，它最好是对每一步的执行都能监控。每一步的执行结果，无论成功与失败，它应该有个回调，才算完整。拥有回调的任务，可以监控任务的执行状况，如果执行失败、超时，可以记录异常信息或者处理个性化的默认值。

CompleteableFuture中也有一些回调方法，例如：thenAccept()，whenComplete()，handle()，exceptionally()等，这些方法也能支持任务的回调，但是前提是任务执行了，才能完成回调。在某些场景中，有些任务单元是可能被SKIP跳过不执行的，不执行的任务也应该有回调。

AsyncTool方法说明

Worker的定义如下，实现IWorker，ICallback函数式接口，并重写下面的4个方法。

4个方法的说明如下：

Worker的定义如下，实现IWorker，ICallback函数式接口，并重写下面的4个方法。4个方法的说明如下：

begin()：Worker开始执行前，先回调begin()。
action()：Worker中执行耗时操作的地方，比如RPC接口调用。
result()：action()执行完毕后，回调result方法，可以在此处处理action中的返回值。
defaultValue()：整个Worker执行异常，或者超时，会回调defaultValue()，Worker返回默认值。

如果没有实现ICallback，会默认执行DefaultCallback的回调方法。DefaultCallback是一个空的回调，里面没有任何逻辑。

通过执行器类Async的beginWork方法提交任务执行。
- Timeout：全组任务超时时间设定，如果Worker任务超时，则Worker结果使用defaultValue()默认值。
- ExecutorService executorService：自定义线程池，不自定义的话，就走默认的COMMON_POOL。默认的线程池是不定长线程池。
- WorkerWrapper… workerWrapper：起始任务，可以是多个。注意不要提交中间节点的任务，只需要提交起始任务即可，编排的后续任务会自动执行。

定义几个测试worker：

package com.itjing.base.concurrency.jdasync;

import cn.hutool.core.date.SystemClock;
import cn.hutool.json.JSONUtil;
import com.jd.platform.async.callback.ICallback;
import com.jd.platform.async.callback.IWorker;
import com.jd.platform.async.worker.WorkResult;
import com.jd.platform.async.wrapper.WorkerWrapper;

import java.util.Map;

public class WorkerA implements IWorker<Integer, Integer>, ICallback<Integer, Integer> {

    /**
     * Worker开始的时候先执行begin
     */
    @Override
    public void begin() {
        System.out.println("A - Thread:" + Thread.currentThread().getName() + "- start --" + SystemClock.now());
    }

    /**
     * Worker中耗时操作在此执行RPC/IO
     * @param object      object
     * @param allWrappers 任务包装
     * @return
     */
    @Override
    public Integer action(Integer object, Map<String, WorkerWrapper> allWrappers) {
        Integer res = object + 1;
        return res;
    }

    /**
     * action执行结果的回调
     * @param success
     * @param param
     * @param workResult
     */
    @Override
    public void result(boolean success, Integer param, WorkResult<Integer> workResult) {
        System.out.println("A - param:" + JSONUtil.toJsonStr(param));
        System.out.println("A - result:" + JSONUtil.toJsonStr(workResult));
        System.out.println("A - Thread:" + Thread.currentThread().getName() + "- end --" + SystemClock.now());
    }

    /**
     * Worker异常时的回调
     * @return
     */
    @Override
    public Integer defaultValue() {
        System.out.println("A - defaultValue");
        return 101;
    }

}

package com.itjing.base.concurrency.jdasync;

import cn.hutool.core.date.SystemClock;
import cn.hutool.json.JSONUtil;
import com.jd.platform.async.callback.ICallback;
import com.jd.platform.async.callback.IWorker;
import com.jd.platform.async.worker.WorkResult;
import com.jd.platform.async.wrapper.WorkerWrapper;

import java.util.Map;

public class WorkerB implements IWorker<Integer, Integer>, ICallback<Integer, Integer> {

    /**
     * Worker开始的时候先执行begin
     */
    @Override
    public void begin() {
        System.out.println("B - Thread:" + Thread.currentThread().getName() + "- start --" + SystemClock.now());
    }

    /**
     * Worker中耗时操作在此执行RPC/IO
     *
     * @param object      object
     * @param allWrappers 任务包装
     * @return
     */
    @Override
    public Integer action(Integer object, Map<String, WorkerWrapper> allWrappers) {
        Integer res = object + 2;
        return res;
    }

    /**
     * action执行结果的回调
     *
     * @param success
     * @param param
     * @param workResult
     */
    @Override
    public void result(boolean success, Integer param, WorkResult<Integer> workResult) {
        System.out.println("B - param:" + JSONUtil.toJsonStr(param));
        System.out.println("B - result:" + JSONUtil.toJsonStr(workResult));

        System.out.println("B - Thread:" + Thread.currentThread().getName() + "- end --" + SystemClock.now());
    }

    /**
     * Worker异常时的回调
     *
     * @return
     */
    @Override
    public Integer defaultValue() {
        System.out.println("B - defaultValue");
        return 102;
    }
}

package com.itjing.base.concurrency.jdasync;

import cn.hutool.core.date.SystemClock;
import cn.hutool.json.JSONUtil;
import com.jd.platform.async.callback.ICallback;
import com.jd.platform.async.callback.IWorker;
import com.jd.platform.async.worker.WorkResult;
import com.jd.platform.async.wrapper.WorkerWrapper;

import java.util.Map;

public class WorkerC implements IWorker<Integer, Integer>, ICallback<Integer, Integer> {

    /**
     * Worker开始的时候先执行begin
     */
    @Override
    public void begin() {
        System.out.println("C - Thread:" + Thread.currentThread().getName() + "- start --" + SystemClock.now());
    }

    /**
     * Worker中耗时操作在此执行RPC/IO
     * @param object      object
     * @param allWrappers 任务包装
     * @return
     */
    @Override
    public Integer action(Integer object, Map<String, WorkerWrapper> allWrappers) {
        Integer res = object + 3;
        return res;
    }

    /**
     * action执行结果的回调
     * @param success
     * @param param
     * @param workResult
     */
    @Override
    public void result(boolean success, Integer param, WorkResult<Integer> workResult) {
        System.out.println("C - param:" + JSONUtil.toJsonStr(param));
        System.out.println("C - result:" + JSONUtil.toJsonStr(workResult));

        System.out.println("C - Thread:" + Thread.currentThread().getName() + "- end --" + SystemClock.now());
    }

    /**
     * Worker异常时的回调
     * @return
     */
    @Override
    public Integer defaultValue() {
        System.out.println("C - defaultValue");
        return 103;
    }
}

开发常见场景

串行场景

next写法：

public static void main(String[] args) {
    //引入Worker工作单元
    WorkerA workerA = new WorkerA();
    WorkerB workerB = new WorkerB();
    WorkerC workerC = new WorkerC();

    //包装Worker，编排串行顺序：C <- B <- A
    //C是最后一步，它没有next
    WorkerWrapper wrapperC = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerC")
    .worker(workerC)
    .callback(workerC)
    .param(3)//3+3
    .build();
    //B的next是C
    WorkerWrapper wrapperB = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerB")
    .worker(workerB)
    .callback(workerB)
    .param(2)//2+2
    .next(wrapperC)
    .build();
    //A的next是B
    WorkerWrapper wrapperA = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerA")
    .worker(workerA)
    .callback(workerA)
    .param(1)//1+1
    .next(wrapperB)
    .build();

    try {
        //Action
        Async.beginWork(1000, wrapperA);
    } catch (ExecutionException | InterruptedException e) {
        e.printStackTrace();
    }

    Async.shutDown();
}

depend写法：

public static void main(String[] args) throws ExecutionException, InterruptedException {
    //引入Worker工作单元
    WorkerA workerA = new WorkerA();
    WorkerB workerB = new WorkerB();
    WorkerC workerC = new WorkerC();
    //A没有depend
    WorkerWrapper wrapperA = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerA")
    .worker(workerA)
    .callback(workerA)
    .param(1)
    .build();

    //B的depend是A
    WorkerWrapper wrapperB = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerB")
    .worker(workerB)
    .callback(workerB)
    .param(2)
    .depend(wrapperA)
    .build();

    //C的depend是B
    WorkerWrapper wrapperC = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerC")
    .worker(workerC)
    .callback(workerC)
    .param(3)
    .depend(wrapperB)
    .build();
    //begin
    Async.beginWork(1000, wrapperA);
}

并行场景

public static void main(String[] args) {
    //引入Worker工作单元
    WorkerA workerA = new WorkerA();
    WorkerB workerB = new WorkerB();
    WorkerC workerC = new WorkerC();

    /**
     * 包装Worker，编排并行顺序
     */

    //A
    WorkerWrapper wrapperA = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerA")
    .worker(workerA)
    .callback(workerA)
    .param(1)//1+1
    .build();
    //B
    WorkerWrapper wrapperB = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerB")
    .worker(workerB)
    .callback(workerB)
    .param(2)//2+2
    .build();
    //C
    WorkerWrapper wrapperC = new WorkerWrapper.Builder<Integer, Integer>()
    .id("workerC")
    .worker(workerC)
    .callback(workerC)
    .param(3)//3+3
    .build();
    try {
        //3个WorkerWrapper一起begin
        Async.beginWork(1000, wrapperA, wrapperB, wrapperC);
    } catch (ExecutionException | InterruptedException e) {
        e.printStackTrace();
    }
}

阻塞等待 - 先串行，后并行

改造WorkerB、WorkerC的action:

public Integer action(Integer object, Map<String, WorkerWrapper> allWrappers) {
    WorkerWrapper workerA = allWrappers.get("workerA");
    System.out.println("获取workerA的结果：" + JSONUtil.toJsonStr(workerA));
    Integer res = 0;
    if (Objects.nonNull(workerA)) {
        Integer result = (Integer) workerA.getWorkResult().getResult();
        res = 2;
        res += result;
    } else {
        res = object + 2;
    }
    return res;
}

next写法：

public static void nextWork() {
    //引入Worker工作单元
    WorkerA workerA = new WorkerA();
    WorkerB workerB = new WorkerB();
    WorkerC workerC = new WorkerC();

    //C是最后一步，它没有next
    WorkerWrapper wrapperC = new WorkerWrapper.Builder<Integer, Integer>()
            .id("workerC")
            .worker(workerC)
            .callback(workerC)
            .param(null)//没有参数，根据A的返回值+3
            .build();
    //B是最后一步，它没有next
    WorkerWrapper wrapperB = new WorkerWrapper.Builder<Integer, Integer>()
            .id("workerB")
            .worker(workerB)
            .callback(workerB)
            .param(null)//没有参数，根据A的返回值+2
            .build();
    //A的next是B、C
    WorkerWrapper wrapperA = new WorkerWrapper.Builder<Integer, Integer>()
            .id("workerA")
            .worker(workerA)
            .callback(workerA)
            .param(1)//1+1
      			//next是B、C
            .next(wrapperB, wrapperC)
            .build();


    try {
        //Action
        Async.beginWork(1000, wrapperA);
    } catch (ExecutionException | InterruptedException e) {
        e.printStackTrace();
    }
}

depend写法：

//A没有depend，就是开始
WorkerWrapper wrapperA = new WorkerWrapper.Builder<Integer, Integer>()
        .id("workerA")
        .worker(workerA)
        .callback(workerA)
        .param(1)
        .build();

//C depend A
WorkerWrapper wrapperC = new WorkerWrapper.Builder<Integer, Integer>()
        .id("workerC")
        .worker(workerC)
        .callback(workerC)
        .param(null)
        .depend(wrapperA)
        .build();
//B depend A
WorkerWrapper wrapperB = new WorkerWrapper.Builder<Integer, Integer>()
        .id("workerB")
        .worker(workerB)
        .callback(workerB)
        .param(null)
        .depend(wrapperA)
        .build();

阻塞等待 - 先并行，后串行

改造WorkerA的action方法：

public Integer action(Integer object, Map<String, WorkerWrapper> allWrappers) {
    WorkerWrapper workerB = allWrappers.get("workerB");
    System.out.println("获取workerB的结果：" + JSONUtil.toJsonStr(workerB));
    WorkerWrapper workerC = allWrappers.get("workerC");
    System.out.println("获取workerC的结果：" + JSONUtil.toJsonStr(workerC));
    Integer res = null;
    if (Objects.nonNull(workerB) && Objects.nonNull(workerC)) {
        Integer resultB = (Integer) workerB.getWorkResult().getResult();
        Integer resultC = (Integer) workerC.getWorkResult().getResult();
        res = resultB + resultC;
    } else {
        res = object + 1;
    }
    return res;
}

next写法：

public static void nextWork() {

    //引入Worker工作单元
    WorkerA workerA = new WorkerA();
    WorkerB workerB = new WorkerB();
    WorkerC workerC = new WorkerC();

    //A是最后一步，没有next
    WorkerWrapper wrapperA = new WorkerWrapper.Builder<Integer, Integer>()
            .id("workerA")
            .worker(workerA)
            .callback(workerA)
            .param(null)//参数是null，A = B + C
            .build();

    //C next A
    WorkerWrapper wrapperC = new WorkerWrapper.Builder<Integer, Integer>()
            .id("workerC")
            .worker(workerC)
            .callback(workerC)
            .param(3)//3+3 = 6
            .next(wrapperA)
            .build();
    //B next A
    WorkerWrapper wrapperB = new WorkerWrapper.Builder<Integer, Integer>()
            .id("workerB")
            .worker(workerB)
            .callback(workerB)
            .param(2)//2+2 = 4
            .next(wrapperA)
            .build();

    try {new SynchronousQueue<Runnable>();
        //Action
        Async.beginWork(4000, wrapperB, wrapperC);
    } catch (ExecutionException | InterruptedException e) {
        e.printStackTrace();
    }
}

depend写法：

//C没有depend，是起始节点
WorkerWrapper wrapperC = new WorkerWrapper.Builder<Integer, Integer>()
        .id("workerC")
        .worker(workerC)
        .callback(workerC)
        .param(3)//3+3 = 6
        .build();
//B没有depend，是起始节点
WorkerWrapper wrapperB = new WorkerWrapper.Builder<Integer, Integer>()
        .id("workerB")
        .worker(workerB)
        .callback(workerB)
        .param(2)//2+2 = 4
        .build();

//A depend B,C
WorkerWrapper wrapperA = new WorkerWrapper.Builder<Integer, Integer>()
        .id("workerA")
        .worker(workerA)
        .callback(workerA)
        .param(null)//参数是null，A = B + C
        .depend(wrapperB, wrapperC)
        .build();

目录CONTENT

京东多线程编排框架AsyncTool

并行框架的使用背景

CompleteableFuture VS AsyncTool

AsyncTool方法说明

开发常见场景

串行场景

并行场景

阻塞等待 - 先串行，后并行

阻塞等待 - 先并行，后串行

评论区