Exemplo n.º 1
0
//-----------------------------------------------------------------------------
void OpenMpAssembler::assemble_cells_and_exterior_facets(
  GenericTensor& A,
  const Form& a, UFC& _ufc,
  std::shared_ptr<const MeshFunction<std::size_t>> cell_domains,
  std::shared_ptr<const MeshFunction<std::size_t>> exterior_facet_domains,
  std::vector<double>* values)
{
  Timer timer("Assemble cells and exterior facets");

  // Set number of OpenMP threads (from parameter systems)
  const int num_threads = parameters["num_threads"];
  omp_set_num_threads(num_threads);

  // Extract mesh
  const Mesh& mesh = a.mesh();

  // Compute facets and facet - cell connectivity if not already computed
  const std::size_t D = mesh.topology().dim();
  mesh.init(D - 1);
  mesh.init(D - 1, D);
  dolfin_assert(mesh.ordered());

  // Get connectivity
  const MeshConnectivity& connectivity = mesh.topology()(D, D - 1);
  dolfin_assert(!connectivity.empty());

  // Dummy UFC object since each thread needs to created its own UFC object
  UFC ufc(_ufc);

  // Form rank
  const std::size_t form_rank = ufc.form.rank();

  // Cell and facet integrals
  ufc::cell_integral* cell_integral = ufc.default_cell_integral.get();
  ufc::exterior_facet_integral* facet_integral
    = ufc.default_exterior_facet_integral.get();

  // Check whether integrals are domain-dependent
  bool use_cell_domains = cell_domains && !cell_domains->empty();
  bool use_exterior_facet_domains
    = exterior_facet_domains && !exterior_facet_domains->empty();

  // Collect pointers to dof maps
  std::vector<const GenericDofMap*> dofmaps;
  for (std::size_t i = 0; i < form_rank; ++i)
    dofmaps.push_back(a.function_space(i)->dofmap().get());

  // Vector to hold dof maps for a cell
  std::vector<ArrayView<const dolfin::la_index>> dofs(form_rank);

  // FIXME: Pass or determine coloring type
  // Define graph type
  std::vector<std::size_t> coloring_type = a.coloring(mesh.topology().dim());
  mesh.color(coloring_type);

  // Get coloring data
  std::map<const std::vector<std::size_t>,
           std::pair<std::vector<std::size_t>,
                     std::vector<std::vector<std::size_t>>>>::const_iterator
    mesh_coloring;
  mesh_coloring = mesh.topology().coloring.find(coloring_type);
  if (mesh_coloring == mesh.topology().coloring.end())
  {
    dolfin_error("OpenMPAssembler.cpp",
                 "perform multithreaded assembly using OpenMP assembler",
                 "Requested mesh coloring has not been computed");
  }

  // Get coloring data
  const std::vector<std::vector<std::size_t>>& entities_of_color
  = mesh_coloring->second.second;

  // If assembling a scalar we need to ensure each threads assemble
  // its own scalar
  std::vector<double> scalars(num_threads, 0.0);

  // UFC cell and vertex coordinates
  ufc::cell ufc_cell;
  std::vector<double> vertex_coordinates;

  // Assemble over cells (loop over colors, then cells of same color)
  const std::size_t num_colors = entities_of_color.size();
  for (std::size_t color = 0; color < num_colors; ++color)
  {
    // Get the array of cell indices of current color
    const std::vector<std::size_t>& colored_cells = entities_of_color[color];

    // Number of cells of current color
    const int num_cell_in_color = colored_cells.size();

    // OpenMP test loop over cells of the same color
    Progress p(AssemblerBase::progress_message(A.rank(), "cells"), num_colors);
#pragma omp parallel for schedule(guided, 20) firstprivate(ufc, ufc_cell, vertex_coordinates, dofs, cell_integral, facet_integral)
    for (int index = 0; index < num_cell_in_color; ++index)
    {
      // Cell index
      const std::size_t cell_index = colored_cells[index];

      // Create cell
      const Cell cell(mesh, cell_index);

      // Get integral for sub domain (if any)
      if (use_cell_domains)
        cell_integral = ufc.get_cell_integral((*cell_domains)[cell_index]);

      // Update to current cell
      cell.get_cell_data(ufc_cell);
      cell.get_vertex_coordinates(vertex_coordinates);

      // Get local-to-global dof maps for cell
      for (std::size_t i = 0; i < form_rank; ++i)
        dofs[i] = dofmaps[i]->cell_dofs(cell_index);

      // Get number of entries in cell tensor
      std::size_t dim = 1;
      for (std::size_t i = 0; i < form_rank; ++i)
        dim *= dofs[i].size();

      // Tabulate cell tensor if we have a cell_integral
      if (cell_integral)
      {
        ufc.update(cell, vertex_coordinates, ufc_cell,
                   cell_integral->enabled_coefficients());
        cell_integral->tabulate_tensor(ufc.A.data(),
                                       ufc.w(),
                                       vertex_coordinates.data(),
                                       ufc_cell.orientation);
      }
      else
        std::fill(ufc.A.begin(), ufc.A.end(), 0.0);

      // Assemble over external facet
      for (FacetIterator facet(cell); !facet.end(); ++facet)
      {
        // Only consider exterior facets
        if (!facet->exterior())
        {
          p++;
          continue;
        }

        // Get local facet index
        const std::size_t local_facet = cell.index(*facet);

        // Get integral for sub domain (if any)
        if (use_exterior_facet_domains)
        {
          // Get global facet index
          const std::size_t facet_index = connectivity(cell_index)[local_facet];
          facet_integral = ufc.get_exterior_facet_integral((*exterior_facet_domains)[facet_index]);
        }

        // Skip integral if zero
        if (!facet_integral)
          continue;

        // FIXME: Do we really need an update version with the local
        //        facet index?
        // Update UFC object
        ufc_cell.local_facet = local_facet;
        ufc.update(cell, vertex_coordinates, ufc_cell,
                  facet_integral->enabled_coefficients());

        // Tabulate tensor
        facet_integral->tabulate_tensor(ufc.A_facet.data(),
                                        ufc.w(),
                                        vertex_coordinates.data(),
                                        local_facet,
                                        ufc_cell.orientation);

        // Add facet contribution
        for (std::size_t i = 0; i < dim; ++i)
          ufc.A[i] += ufc.A_facet[i];
      }

      // Add entries to global tensor
      if (values && form_rank == 0)
        (*values)[cell_index] = ufc.A[0];
      else if (form_rank == 0)
        scalars[omp_get_thread_num()] += ufc.A[0];
      else
        A.add_local(&ufc.A[0], dofs);
    }

    p++;
  }

  // If we assemble a scalar we need to sum the contributions from each thread
  if (form_rank == 0)
  {
    const double scalar_sum = std::accumulate(scalars.begin(),
                                              scalars.end(), 0.0);
    A.add_local(&scalar_sum, dofs);
  }
}
Exemplo n.º 2
0
//-----------------------------------------------------------------------------
void OpenMpAssembler::assemble_interior_facets(
  GenericTensor& A,
  const Form& a, UFC& _ufc,
  std::shared_ptr<const MeshFunction<std::size_t>> domains,
  std::shared_ptr<const MeshFunction<std::size_t>> cell_domains,
  std::vector<double>* values)
{
  warning("OpenMpAssembler::assemble_interior_facets is untested.");

  // Extract mesh
  const Mesh& mesh = a.mesh();

  // Topological dimension
  const std::size_t D = mesh.topology().dim();

  dolfin_assert(!values);

  // Skip assembly if there are no interior facet integrals
  if (!_ufc.form.has_interior_facet_integrals())
    return;

  Timer timer("Assemble interior facets");

  // Set number of OpenMP threads (from parameter systems)
  omp_set_num_threads(parameters["num_threads"]);

  // Get integral for sub domain (if any)

  bool use_domains = domains && !domains->empty();
  bool use_cell_domains = cell_domains && !cell_domains->empty();
  if (use_domains)
  {
    dolfin_error("OpenMPAssembler.cpp",
                 "perform multithreaded assembly using OpenMP assembler",
                 "Subdomains are not yet handled");
  }

  // Color mesh
  std::vector<std::size_t> coloring_type = a.coloring(D - 1);
  mesh.color(coloring_type);

  // Dummy UFC object since each thread needs to created its own UFC object
  UFC ufc(_ufc);

  // Form rank
  const std::size_t form_rank = ufc.form.rank();

  // Collect pointers to dof maps
  std::vector<const GenericDofMap*> dofmaps;
  for (std::size_t i = 0; i < form_rank; ++i)
    dofmaps.push_back(a.function_space(i)->dofmap().get());

  // Vector to hold dofs for cells
  std::vector<std::vector<dolfin::la_index>> macro_dofs(form_rank);

  // Interior facet integral
  const ufc::interior_facet_integral* integral
    = ufc.default_interior_facet_integral.get();

  // Compute facets and facet - cell connectivity if not already computed
  mesh.init(D - 1);
  mesh.init(D - 1, D);
  dolfin_assert(mesh.ordered());

  // Get coloring data
  std::map<const std::vector<std::size_t>,
           std::pair<std::vector<std::size_t>,
                     std::vector<std::vector<std::size_t>>>>::const_iterator
    mesh_coloring;
  mesh_coloring = mesh.topology().coloring.find(coloring_type);

  // Check that requested coloring has been computed
  if (mesh_coloring == mesh.topology().coloring.end())
  {
    dolfin_error("OpenMPAssembler.cpp",
                 "perform multithreaded assembly using OpenMP assembler",
                 "Requested mesh coloring has not been computed");
  }

  // Get coloring data
  const std::vector<std::vector<std::size_t>>& entities_of_color
    = mesh_coloring->second.second;

  // UFC cells and vertex coordinates
  ufc::cell ufc_cell0, ufc_cell1;
  std::vector<double> vertex_coordinates0, vertex_coordinates1;

  // Assemble over interior facets (loop over colours, then cells of same color)
  const std::size_t num_colors = entities_of_color.size();
  for (std::size_t color = 0; color < num_colors; ++color)
  {
    // Get the array of facet indices of current color
    const std::vector<std::size_t>& colored_facets = entities_of_color[color];

    // Number of facets of current color
    const int num_facets = colored_facets.size();

    // OpenMP test loop over cells of the same color
    Progress p(AssemblerBase::progress_message(A.rank(), "interior facets"),
               mesh.num_facets());
#pragma omp parallel for schedule(guided, 20) firstprivate(ufc, ufc_cell0, ufc_cell1, vertex_coordinates0, vertex_coordinates1, macro_dofs, integral)
    for (int facet_index = 0; facet_index < num_facets; ++facet_index)
    {
      // Facet index
      const std::size_t index = colored_facets[facet_index];

      // Create cell
      const Facet facet(mesh, index);

      // Only consider interior facets
      if (facet.exterior())
      {
        p++;
        continue;
      }

      // Get integral for sub domain (if any)
      if (use_domains)
        integral = ufc.get_interior_facet_integral((*domains)[facet]);

      // Skip integral if zero
      if (!integral)
        continue;

      // Get cells incident with facet (which is 0 and 1 here is arbitrary)
      dolfin_assert(facet.num_entities(D) == 2);
      std::size_t cell_index_plus = facet.entities(D)[0];
      std::size_t cell_index_minus = facet.entities(D)[1];

      if (use_cell_domains && (*cell_domains)[cell_index_plus] < (*cell_domains)[cell_index_minus])
        std::swap(cell_index_plus, cell_index_minus);

      // The convention '+' = 0, '-' = 1 is from ffc
      const Cell cell0(mesh, cell_index_plus);
      const Cell cell1(mesh, cell_index_minus);

      // Get local index of facet with respect to each cell
      const std::size_t local_facet0 = cell0.index(facet);
      const std::size_t local_facet1 = cell1.index(facet);

      // Update UFC cell
      cell0.get_vertex_coordinates(vertex_coordinates0);
      cell0.get_cell_data(ufc_cell0, local_facet0);
      cell1.get_vertex_coordinates(vertex_coordinates1);
      cell1.get_cell_data(ufc_cell1, local_facet1);

      // Update to current pair of cells
      ufc.update(cell0, vertex_coordinates0, ufc_cell0,
                 cell1, vertex_coordinates1, ufc_cell1,
                 integral->enabled_coefficients());

      // Tabulate dofs for each dimension on macro element
      for (std::size_t i = 0; i < form_rank; i++)
      {
        // Get dofs for each cell
        const ArrayView<const dolfin::la_index> cell_dofs0
          = dofmaps[i]->cell_dofs(cell0.index());
        const ArrayView<const dolfin::la_index> cell_dofs1
          = dofmaps[i]->cell_dofs(cell1.index());

        // Create space in macro dof vector
        macro_dofs[i].resize(cell_dofs0.size() + cell_dofs1.size());

        // Copy cell dofs into macro dof vector
        std::copy(cell_dofs0.begin(), cell_dofs0.end(), macro_dofs[i].begin());
        std::copy(cell_dofs1.begin(), cell_dofs1.end(),
                  macro_dofs[i].begin() + cell_dofs0.size());
      }

      // Tabulate exterior interior facet tensor on macro element
      integral->tabulate_tensor(ufc.macro_A.data(),
                                ufc.macro_w(),
                                vertex_coordinates0.data(),
                                vertex_coordinates1.data(),
                                local_facet0,
                                local_facet1,
                                ufc_cell0.orientation,
                                ufc_cell1.orientation);

      // Add entries to global tensor
      std::vector<ArrayView<const la_index>>
        macro_dofs_p(macro_dofs.size());
      for (std::size_t i = 0; i < macro_dofs.size(); ++i)
        macro_dofs_p[i].set(macro_dofs[i]);
      A.add_local(ufc.macro_A.data(), macro_dofs_p);

      p++;
    }
  }
}
Exemplo n.º 3
0
//-----------------------------------------------------------------------------
void OpenMpAssembler::assemble_cells(
  GenericTensor& A, const Form& a,
  UFC& _ufc,
  std::shared_ptr<const MeshFunction<std::size_t>> domains,
  std::vector<double>* values)
{
  // Skip assembly if there are no cell integrals
  if (!_ufc.form.has_cell_integrals())
    return;

  Timer timer("Assemble cells");

  // Set number of OpenMP threads (from parameter systems)
  const std::size_t num_threads = parameters["num_threads"];
  omp_set_num_threads(num_threads);

  // Extract mesh
  const Mesh& mesh = a.mesh();

  // FIXME: Check that UFC copy constructor is dealing with copying
  // pointers correctly
  // Dummy UFC object since each thread needs to created its own UFC object
  UFC ufc(_ufc);

  // Form rank
  const std::size_t form_rank = ufc.form.rank();

  // Cell integral
  const ufc::cell_integral* integral = ufc.default_cell_integral.get();

  // Check whether integral is domain-dependent
  bool use_domains = domains && !domains->empty();

  // Collect pointers to dof maps
  std::vector<const GenericDofMap*> dofmaps;
  for (std::size_t i = 0; i < form_rank; ++i)
    dofmaps.push_back(a.function_space(i)->dofmap().get());

  // Vector to hold dof map for a cell
  std::vector<ArrayView<const dolfin::la_index>> dofs(form_rank);

  // Color mesh
  std::vector<std::size_t> coloring_type = a.coloring(mesh.topology().dim());
  mesh.color(coloring_type);

  // Get coloring data
  std::map<const std::vector<std::size_t>,
           std::pair<std::vector<std::size_t>,
                     std::vector<std::vector<std::size_t>>>>::const_iterator
    mesh_coloring;
  mesh_coloring = mesh.topology().coloring.find(coloring_type);
  if (mesh_coloring == mesh.topology().coloring.end())
  {
    dolfin_error("OpenMPAssembler.cpp",
                 "perform multithreaded assembly using OpenMP assembler",
                 "Requested mesh coloring has not been computed");
  }

  // Get coloring data
  const std::vector<std::vector<std::size_t>>& entities_of_color
    = mesh_coloring->second.second;

  // If assembling a scalar we need to ensure each threads assemble
  // its own scalar
  std::vector<double> scalars(num_threads, 0.0);

  // Assemble over cells (loop over colours, then cells of same color)
  const std::size_t num_colors = entities_of_color.size();
  Progress p("Assembling cells (threaded)", num_colors);
  for (std::size_t color = 0; color < num_colors; ++color)
  {
    // Get the array of cell indices of current color
    const std::vector<std::size_t>& colored_cells = entities_of_color[color];

    // Number of cells of current color
    const int num_cells = colored_cells.size();

    ufc::cell ufc_cell;
    std::vector<double> vertex_coordinates;

    // OpenMP test loop over cells of the same color
#pragma omp parallel for schedule(guided, 20) firstprivate(ufc, ufc_cell, vertex_coordinates, dofs, integral)
    for (int cell_index = 0; cell_index < num_cells; ++cell_index)
    {
      // Cell index
      const std::size_t index = colored_cells[cell_index];

      // Create cell
      const Cell cell(mesh, index);

      // Get integral for sub domain (if any)
      if (use_domains)
        integral = ufc.get_cell_integral((*domains)[cell]);

      // Skip integral if zero
      if (!integral)
        continue;

      // Update to current cell
      cell.get_cell_data(ufc_cell);
      cell.get_vertex_coordinates(vertex_coordinates);
      ufc.update(cell, vertex_coordinates, ufc_cell,
                 integral->enabled_coefficients());

      // Get local-to-global dof maps for cell
      for (std::size_t i = 0; i < form_rank; ++i)
        dofs[i] = dofmaps[i]->cell_dofs(index);

      // Tabulate cell tensor
      integral->tabulate_tensor(ufc.A.data(),
                                ufc.w(),
                                vertex_coordinates.data(),
                                ufc_cell.orientation);

      // Add entries to global tensor
      if (values && form_rank == 0)
        (*values)[cell_index] = ufc.A[0];
      else if (form_rank == 0)
        scalars[omp_get_thread_num()] += ufc.A[0];
      else
        A.add_local(ufc.A.data(), dofs);
    }
    p++;
  }

  // If we assemble a scalar we need to sum the contributions from each thread
  if (form_rank == 0)
  {
    const double scalar_sum = std::accumulate(scalars.begin(), scalars.end(),
                                              0.0);
    A.add_local(&scalar_sum, dofs);
  }
}