On Thu, Mar 13, 2014 at 09:36:42AM +0000, Garth N. Wells wrote: > > > On Thu, 13 Mar, 2014 at 9:23 AM, Johannes Ring <[email protected]> > wrote: > >On Wed, Mar 12, 2014 at 6:30 PM, Jan Blechta > ><[email protected]> wrote: > >> On Wed, 12 Mar 2014 17:19:31 +0100 > >> Benjamin Kehlet <[email protected]> wrote: > >> > >>> Hello! > >>> > >>> This code snippet > >>>----------------------------------------------------------------------- > >>> from dolfin import * > >>> > >>> m = Mesh() > >>> > >>> editor = MeshEditor() > >>> editor.open(m, 2, 2) > >>> editor.init_vertices(3) > >>> editor.add_vertex(0, Point(.0, .0)) > >>> editor.add_vertex(1, Point(1., .0)) > >>> editor.add_vertex(2, Point(0., 1.)) > >>> > >>> editor.init_cells(1) > >>> editor.add_cell(0, 0, 1, 2) > >>> editor.close() > >>> > >>> print MeshQuality.radius_ratio_min_max(m) > >>>----------------------------------------------------------------------- > >>> > >>> gives this error (when Dolfin is built with MPI support) > >> > >> Can't reproduce. > > > >I got the same error as Benjamin. > > I get the error too. > > Initialising MPI is a long-standing issue that we've been dodging. > The solution in other libraries is that the user makes a call at the > start of a program to initialise MPI. We have a sprinkling of > behind-the-scenes initialisation of MPI. It's not ideal to have > calls all over the place the initialise MPI. I'm not sure what the > best solution is to balance performance and simplicity.
Wouldn't it work to say that all classes that are parallel-aware need to initialize MPI? In this case the Mesh class. The cost should be virtually zero. I don't know what the cost is for calling MPI_Initialized() but we could add an extra flag in DOLFIN which is set when SubSystemsManager::init_mpi() is called so that a call to MPI_Initialized is not necessary when we know that we ourselves have actually initialized MPI explicitly before. -- Anders _______________________________________________ fenics mailing list [email protected] http://fenicsproject.org/mailman/listinfo/fenics
