170:            lock( $contacts{$user_id} );
  DB<2> print is_shared($contacts{$user_id})
226839368
  DB<3> n
lock can only be used on shared values at get_contacts_pool_photos.pl line 170.
 at get_contacts_pool_photos.pl line 170
        main::get_contacts_pool_photos() called at get_contacts_pool_photos.pl line 93