On 10/02/11 07:19, 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 would like to remove the mesh refine functions, or re-write them. My objections to the current implementation are: - It forces a mesh hierarchy on users, even if this is not desired - It is not const-correct. - The 'parent' can go out of scope, leaving the 'child' with a dangling pointer. We should be very particular about const-correctness throughout (i.e. not use const_cast unless absolutely necessary) because it makes multi-threading *much* easier to develop. Garth > -- > Anders _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
