dolfin team mailing list archive

[Johan Hake <johan.hake@xxxxxxxxx>]

On Wednesday February 9 2011 23:19:10 Anders Logg wrote:
> B1;2600;0cOn Wed, Feb 09, 2011 at 11:03:28PM +0000, Garth N. Wells wrote:
> > On 09/02/11 22:43, Anders Logg wrote:
> > > On Wed, Feb 09, 2011 at 10:11:40AM -0800, Johan Hake wrote:
> > >> Hello!
> > >> 
> > >> I am pretty sure the reason the Macbot still complains (mesh unit
> > >> test) is that refine is broken for SWIG 2.0.
> > >> 
> > >> I think it is some premature destruction of a refined mesh. I would
> > >> suggest we implement a full shared_ptr version of the interface to
> > >> get around this problem. I have no clue of why it works for SWIG
> > >> 1.3.40. Probably because a faulty implementation.
> > >> 
> > >> I also suggest more developers upgrade to SWIG 2.0.1 and maybe one of
> > >> the linux build bots two? If it is only the Macbot that uses SWIG 2.0
> > >> it is easily to think it is some Mac specific error.
> > >> 
> > >> Johan
> > > 
> > > I plan to merge with main tomorrow if my buildbot is green. Then Marie
> > > also needs to merge (we have both touched refine.h/cpp). Then we can
> > > sort out the shared_ptrs.
> > 
> > I really don't get the approach to hierarchies. Mesh refinement was
> > simple, and now something simple has become complex (with bugs that are
> > hard to track down because of the introduced complexity).
> 
> I really don't understand what the problem is. Mesh refinement is just
> as simple as it used to be, the Mesh class itself is (almost) as
> simple as it used to be (one added inheritance), and the Hierarchical
> base class is also a very simple class (just stores two pointers for
> child and parent). All the complexity is in refine.cpp, which only
> kicks in if you do something like refine(variational_problem) or
> refine(function_space).
> 
> > This hierarchy business looks viral - now I get Swig warnings for
> > DirichleBC.
> > 
> > I would much rather keep basic classes simple, and have hierarchical
> > containers that can keep track of parent/child relationships. The
> > present approach seems to take a narrow/immediate view on the issue.
> 
> I think that would lead to more complex code. We would need to store
> quite a few different relationship trees separately from the objects.
> 
> The problems we see now are related to SWIG and correct use of
> shared_ptrs. We've had quite a few SWIG/shared_ptr problems in the
> past and figured out how to fix them. I'm sure we will handle this
> too.

I think we(TM) have figured it out now! 

Garth and you, have a point regarding Hierarchical causing a lot of trouble 
for the SWIG interface as we have a split implementation for SWIG 2.0 and 
1.3.X for the shared_ptr interface. But hopefully (Ubuntu 11.10?) we will be 
able to ditch 1.3.40 sometime.

Johan