Q:

Dispatch event occurs multiple times

I'm using a dispatch event in Symfony, And I don't understand because I have the kernel.response twice.
Controller:
/**
 * @Route("/evento", name="evento")
 */
public function eventoAction()
{
    $dispatcher = new EventDispatcher();
    $subscriber = new StoreSubriber();
    $dispatcher->addSubscriber($subscriber);
    $event = new FilterOrderEvent($order);
    $dispatcher->dispatch(StoreEvents::STORE_ORDER,$event);
    return $this->render('::event.html.twig');
}

Subscriber:
namespace AppBundle\Events;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;

class StoreSubriber implements EventSubscriberInterface
{

    public static function getSubscribedEvents()
    {
        return array(
            'kernel.request' => array(
                array('onKernelResponsePre', -10),
                array('onKernelResponseMid', 5),
                array('onKernelResponsePost', 0),
            ),
            'store.order' => array('onStoreOrder', 0),
        );
    }

    public function onKernelResponsePre(GetResponseEvent $event)
    {
        echo "<br>";
        echo "onKernelResponsePre";
    }

    public function onKernelResponseMid(GetResponseEvent $event)
    {
        echo "<br>";
        echo "onKernelResponseMid";
    }

    public function onKernelResponsePost(GetResponseEvent $event)
    {
        echo "<br>";
        echo "onKernelResponsePost";
    }

    public function onStoreOrder(FilterOrderEvent $event)
    {
        echo "<br>";
        echo "ORDER";
    }
}

service.yml:
services:
    user_check_token:
        class: AppBundle\Events\StoreSubriber
        tags:
            - { name: kernel.event_subscriber }

My Output:
onKernelResponseMid
onKernelResponsePost
onKernelResponsePre
ORDER
Events ( twig )

onKernelResponseMid
onKernelResponsePost
onKernelResponsePre

My question is, why am I seeing onKernelResponseMid, onKernelResponsePost, and onKernelResponsePre twice?

A:

I would say because you subscribed to the event twice.

First inside your eventoAction $dispatcher->addSubscriber($subscriber);
Second with Tagging your subscriber in your configuration tags: - { name: kernel.event_subscriber }

Try removing this $dispatcher->addSubscriber($subscriber); from eventoAction.
edit
other possible reasons

multiple kernel event event can fire for each request, symfony can do subrequest, anywhere during running the code. This can be also in twig like this: {{ render(controller('AcmeArticleBundle:Article:recentArticles') }}. As this is another real request the event will fire. To handle this you need to add conditions to your subscriber to filter only request which you want to handle
if you use prod environment clear cache as your twice registered subscriber can be cached.

edit 2
how to debug subrequest
To easily find out if there where any sub request going on, you can look in the web debug toolbar.

go to the fullpage view (click any section)
upper left corner find link "last 10" (meaning show last 10 requests)
at glance you should see how each request went one after another, with they urls and times, and possibility to go to that request full page debug.

This way you'll should be able to find if there are any subrequests and where they originated from.

