index.php

<?php

class Afterhours {

    private $_enabled = false;

    private $_jobs = array();

    private $_functions = array();


    public __construct() {

        $apiName = php_sapi_name();

        if (substr($apiName, 0, 3) === 'cgi' && function_exists('fastcgi_finish_request'))
            $this->_enabled = true;

    }

    public function addJob(string $functionName, array $args = array()) {

        $this->_jobs[] = array(
            'function' => $functionName,
            'args' => $args
        );

    }

    public function addFunction($name, $function) {

        if (!isset($this->_functions[$name]) && is_callable($function)) {

            $this->_functions[$name] = $function;

            return true;

        }

        return false;

    }

    public function runJobs($force = false) {

        if ($this->_enabled || $force) {

            if (function_exists('fastcgi_finish_request'))
                fastcgi_finish_request();

            foreach ($this->_jobs as $job) {

                $function = $this->_functions[$job['function']];
                $args = $job['args'];

                call_user_func_array($function, $args);

            }

        }

    }

}