LoadBalance of GeometryGrid is deactivated
When using a GeometryGrid
wrapper in parallel, it is surprising that the loadBalance(...)
functions are actually commented out. The effect is that the GridDefaultImplementation
is used, which means: no load balancing at all. This means, GeometryGrid
cannot be used with most grid managers that require a loadBalance()
call after setup (except if you call that function on the host grid directly).
The corresponding code, see https://gitlab.dune-project.org/core/dune-grid/-/blob/master/dune/grid/geometrygrid/grid.hh?ref_type=heads#L437 simply has an #if 0
without proper documentation why, since about 13y. So, no-one used GeometryGrid
in parallel since then?
In my opinion, the behavior is a bug. The proper behavior would be at least an error message if that function does not work with the GeometryGrid
wrapper. One aspect could probably be difficult: If a DiscreteCoordFunction
is used that is based on discrete data, then this data also needs to be communicated in the load-balancing step. But, I think, this could be implemented.