WP: Run once function

run-once.php

<?php
/**
 * The main template file.
 *
 * @package WordPress
 */

function run_once($key){

    $test_case = get_option('run_once');
    if (isset($test_case[$key]) && $test_case[$key]){
        return false;
    }else{
        $test_case[$key] = true;
        update_option('run_once',$test_case);
        return true;
    }
}

/**
 * Funciones que sólo se ejecutarán una vez
 */
if (run_once('add_user_role')){
    //do you stuff and it will only run once

}