<?php

class Triple
{
   const MAX = 3;
   private static $triples = array();
   private $id = null;
   private $message = null;

   private function __construct($id) {
      $this->id = $id;
      echo "An instance $id is generated.\n";
   }

   public function &getInstance() {
      $len = count(Triple::$triples);
      if ( $len < Triple::MAX ) {
         Triple::$triples[$len] = new Triple($len);
         return Triple::$triples[$len];
      } else {
         $id = mt_rand(0, (Triple::MAX - 1));
         echo "Slot full! obj $id is returned.\n";
         return Triple::$triples[$id];
      }
   }

   public function setMessage($msg) {
      $this->message = $msg;
   }

   public function getMessage() {
      return $this->id.": ".$this->message;
   }

}

?>