feat(initial): added portable mfem build system

2026-09-05 07:11:05 -04:00
commit 6a54f2625e
49 changed files with 4344 additions and 0 deletions
--- a/examples/parallel_hypre.cpp
+++ b/examples/parallel_hypre.cpp
@@ -0,0 +1,80 @@
+#include <meson_mfem_template/config.hpp>
+#include <mfem.hpp>
+
+#include <cmath>
+#include <iostream>
+
+#if !MESON_MFEM_HAS_MPI || !MESON_MFEM_HAS_HYPRE
+#error "This example requires the MPI/Hypre capability"
+#endif
+
+int main(int argc, char **argv)
+{
+   mfem::Mpi::Init(argc, argv);
+   mfem::Hypre::Init();
+   const int rank = mfem::Mpi::WorldRank();
+   const char *device_name = argc > 1 ? argv[1] : "cpu";
+   mfem::Device device(device_name);
+
+   mfem::Mesh serial_mesh = mfem::Mesh::MakeCartesian2D(
+      8, 8, mfem::Element::QUADRILATERAL, true, 1.0, 1.0);
+   mfem::ParMesh mesh(MPI_COMM_WORLD, serial_mesh);
+   serial_mesh.Clear();
+
+   mfem::H1_FECollection elements(2, mesh.Dimension());
+   mfem::ParFiniteElementSpace space(&mesh, &elements);
+   mfem::Array<int> essential_boundary(mesh.bdr_attributes.Max());
+   essential_boundary = 1;
+   mfem::Array<int> essential_dofs;
+   space.GetEssentialTrueDofs(essential_boundary, essential_dofs);
+
+   mfem::ConstantCoefficient one(1.0);
+   mfem::ParLinearForm rhs(&space);
+   rhs.AddDomainIntegrator(new mfem::DomainLFIntegrator(one));
+   rhs.Assemble();
+
+   mfem::ParGridFunction solution(&space);
+   solution = 0.0;
+   mfem::ParBilinearForm diffusion(&space);
+   diffusion.AddDomainIntegrator(new mfem::DiffusionIntegrator(one));
+   diffusion.Assemble();
+
+   mfem::OperatorPtr matrix;
+   mfem::Vector linear_rhs;
+   mfem::Vector linear_solution;
+   diffusion.FormLinearSystem(
+      essential_dofs, solution, rhs, matrix, linear_solution, linear_rhs);
+
+   mfem::HypreBoomerAMG boomer_amg;
+   boomer_amg.SetPrintLevel(0);
+   mfem::CGSolver solver(MPI_COMM_WORLD);
+   solver.SetPreconditioner(boomer_amg);
+   solver.SetOperator(*matrix);
+   solver.SetRelTol(1e-10);
+   solver.SetAbsTol(0.0);
+   solver.SetMaxIter(300);
+   solver.SetPrintLevel(0);
+   solver.Mult(linear_rhs, linear_solution);
+   diffusion.RecoverFEMSolution(linear_solution, rhs, solution);
+
+#if MESON_MFEM_HAS_GSLIB
+   mfem::FindPointsGSLIB find_points(MPI_COMM_WORLD);
+#endif
+#if MESON_MFEM_HAS_SUNDIALS
+   mfem::CVODESolver cvode(MPI_COMM_WORLD, CV_BDF);
+#endif
+
+   const double local_norm = solution.Norml2();
+   double global_norm = 0.0;
+   MPI_Allreduce(&local_norm, &global_norm, 1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
+   if (rank == 0)
+   {
+      std::cout << "MFEM parallel Poisson: ranks=" << mfem::Mpi::WorldSize()
+                << " global_dofs=" << space.GlobalTrueVSize()
+                << " norm_sum=" << global_norm
+                << " device=" << device_name << '\n';
+   }
+   return solver.GetConverged() && std::isfinite(global_norm) && global_norm > 0.0
+             ? 0
+             : 2;
+}