PHP Session Lifetime: A work around session.gc_maxlifetime

I needed to limit my session life time in a specific site running in my remote server. But could not set session.gc_maxlifetime. Also I know that session.gc_maxlifetime is not good! It is not reliable and it's tricky to get a different session max life time for each site running in your server.

So I made my own script that would clean session and cookies after a predefined number of minutes. Then all I had to do is to include this script in the start of my index.php:

// checks if session is idle for too much time
// if it is it will erase all session vars!
// if not it will update last activity time
// returns true if session was wiped
function session_check() {
 // time out in seconds
 $max_idle_time = 10 * 60;
 // name of session variable used to store last activity
 $sname = '_session_last_activity';
 $cleaned = false;

 // start session if it wasn't yet
 if (session_id() == '') session_start();

 // check if session variable is set
 if (isset($_SESSION[$sname])) {
  $t_old = $_SESSION[$sname];
  $t_now = mktime();
  // check if session expired
  if ($t_now - $t_old > $max_idle_time) {
   // wipe sessions
   session_unset();
   session_destroy();
   $_SESSION = array();
   // wipe cookies
   foreach ($_COOKIE as $key => $value) setcookie($key, '',
   time()-1);
   $cleaned = true;
  }
 }
 // create or refresh session
 $_SESSION[$sname] = mktime();

 return $cleaned;
}

// call funtion
if (session_check()) {
 // echo 'Session was just cleaned...';
}