我有一个递归批量任务，我将它放入ForkJoinPool线程池中执行。

public class SomeTask extends RecursiveAction {
    @Override
    protected void compute() {
       //Some recursive logic...
    }
}

public class Main {

    public static void main(String[] args) {
        startForkJoinPool();
    }

    private void startForkJoinPool() {
       SomeTask someTask = new SomeTask();

       ForkJoinPool pool = new ForkJoinPool(4);
       pool.invoke(someTask);
       pool.shutdown();
    }
}

现在我需要在另外两个并行线程中执行此逻辑。
我决定尝试使用ExecutorService线程池，当我将实体放入其中执行时，我发现它们不是并行执行的，而是其中一个线程在第一个线程的持续时间内处于停顿状态。

public class SomeTask extends RecursiveAction {
    @Override
    protected void compute() {
       //Some recursive logic...
    }
}

public class Main {

    public static void main(String[] args) {
        List<Thread> threadList = new ArrayList<>();
        threadList.add(new Thread(() -> startForkJoinPool()));
        threadList.add(new Thread(() -> startForkJoinPool()));

        ExecutorService executorService = Executors.newFixedThreadPool(2);
        threadList.forEach(executorService::execute);
        executorService.shutdown();
    }

    private void startForkJoinPool() {
       SomeTask someTask = new SomeTask();

       ForkJoinPool pool = new ForkJoinPool(4);
       pool.invoke(someTask);
       pool.shutdown();
    }
}

请告诉我，我做错了什么？提前非常感谢任何能给我指出正确方向的人。