Im fine with the proposed removal - in general anyone outside the library deleting nodes deserves what they get! ;-)
On Nov 11, 2011, at 10:26 AM, "Roy Stogner" <[email protected]> wrote: > > We have virtual destructors for Node and its parent classes > (DofObject, TypeVector, Point, ReferenceCountedObject<Node>, and > ReferenceCounter) now, and the resulting vptr tacks on 8 bytes (4 on > 32-bit systems) to each Node in the mesh. Since there's no longer any > other virtual functions in those classes, the vptr ought to go away if > we make the destructor non-virtual, saving us a few megabytes of > memory on large problems. So I'm thinking of getting rid of the > virtual destructors. > > The problem is then that if anyone tries to delete a Node through a > pointer-to-parent-class (or delete any other ReferenceCountedObject > subclass through a pointer-to-RCO, or delete an Elem through a > pointer-to-DofObject...), it would be undefined behavior. Of course, > it would still be okay to delete a subclass of Elem, which will still > have its vptr regardless, through a pointer-to-Elem. > > I'm happy with the alternative solution of "don't ever delete a Node > through a pointer-to-parent-class, etc.", but if anyone else isn't > happy with that then please speak up and veto me. > > (Cc: to libmesh-users in case anyone's depending on that level of OOP > in their application code) > > > Sadly, although the above discussion is about efficiency, this issue > came up in the context of correctness: when generating MPI datatypes > for C++ classes with vptrs, you need to take the changed offsets into > account. Expect to see libMesh 0.7.2.1 out soon, with the new > exciting feature of "Parallel::*(Point&) actually works properly in > 3D"... > --- > Roy > > ------------------------------------------------------------------------------ > RSA(R) Conference 2012 > Save $700 by Nov 18 > Register now > http://p.sf.net/sfu/rsa-sfdev2dev1 > _______________________________________________ > Libmesh-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/libmesh-devel ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
