function my_session_start($timeout = 1440) {
ini_set(‘session.gc_maxlifetime’, $timeout);
session_start();
 
if (isset($_SESSION[‘timeout_idle’]) && $_SESSION[‘timeout_idle’] < time()) {
session_destroy();
session_start();
session_regenerate_id();
$_SESSION = array();
}
 
$_SESSION[‘timeout_idle’] = time() + $timeout;
}
 

fonte: www.sastgroup.com