On 10/02/11 09:13, Anders Logg wrote: > On Thu, Feb 10, 2011 at 08:44:21AM +0000, Garth N. Wells wrote: >> >> >> 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 doesn't. Normal users will do > > mesh = refine(mesh); >
This doesn't work. I get a compile error. Garth > and then no hierarchy is stored (in C++). It would be very easy to add > a parameter "store_hierarchy" which defaults to false if that is > desired. > >> - It is not const-correct. > > I believe it is const-correct in Marie's branch. > >> - The 'parent' can go out of scope, leaving the 'child' with a dangling >> pointer. > > It shouldn't go out of scope since we use shared ptrs. It's the same > issue as everywhere else where we pass by reference and use > reference_to_no_delete_pointer. It's not special for the refinement > functions. > > -- > Anders > > >> 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 >> _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
