protected function unfinishedResponses()
    {
        $now = TimeSupport::now();
        $unfinishedReps = [];

        foreach ($this->reps as $pid=>$response)
        {
            if ($now >= $response->timeout)
            {
                $unfinishedReps[] = $response;
                $response->timeout = $now + $response->timeoutIncrease;
            }
        }

        return $unfinishedReps;
    }