singlton.php

<?php
class Singlton {

	// Singlton instance.
	static $instance = null;

	// Do not create multiples.
	private function __construct() {
	}

	/**
	 * Return singlton instance. Create if necessary.
	 * 
	 * @return Singlton
	 */
	public static function get_instance() {
		if ( null === self::$instance ) {
			self::$instance = new Singlton();
		}

		return self::$instance;
	}
}