MyRecursiveAction.java

package com.study.forkjoinpool;

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.RecursiveAction;

/**
 * 설명 :
 *
 * @author Hardy(조민국) / dev.mingood@dreamus.io
 * @since 2021. 01. 08
 */
class MyRecursiveAction extends RecursiveAction {

    private long workLoad;

    public MyRecursiveAction(long workLoad) {
        this.workLoad = workLoad;
    }

    @Override
    protected void compute() {
        String threadName = Thread.currentThread().getName();

        if (this.workLoad > 16) {
            System.out.println("[" + threadName + "] Splitting workLoad : " + this.workLoad);

            List<MyRecursiveAction> subtasks = new ArrayList<>(this.createSubtasks());

            for (MyRecursiveAction subtask : subtasks) {
                subtask.fork();
            }
        } else {
            System.out.println("Doing workLoad myself: " + this.workLoad);
        }
    }

    private List<MyRecursiveAction> createSubtasks() {
        List<MyRecursiveAction> subtasks = new ArrayList<>();

        MyRecursiveAction subtask1 = new MyRecursiveAction(this.workLoad / 2);
        MyRecursiveAction subtask2 = new MyRecursiveAction(this.workLoad / 2);

        subtasks.add(subtask1);
        subtasks.add(subtask2);
        return subtasks;
    }

}