Symfony2: Manage user roles and authentication state

sf2-security.php

$token = $this->get('security.context')->getToken();
// do things that change user's roles
$token->setAuthenticated(false);

/* OR */

// Add new role
$user->addRole('ROLE_NEW');

// persist the user and it's new role to database 
// ...

// Generate new token with new roles
$token = new \Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken(
  $user,
  null,
  'main',
  $user->getRoles()
);