C++ MeshBase::is_serial方法代码示例

void LocationMap<T>::init(MeshBase& mesh)
{
  // This function must be run on all processors at once
  // for non-serial meshes
  if (!mesh.is_serial())
    parallel_only();

  START_LOG("init()", "LocationMap");

  // Clear the old map
  _map.clear();

  // Cache a bounding box
  _lower_bound.clear();
  _lower_bound.resize(LIBMESH_DIM, std::numeric_limits<Real>::max());
  _upper_bound.clear();
  _upper_bound.resize(LIBMESH_DIM, -std::numeric_limits<Real>::max());

  MeshBase::node_iterator       it  = mesh.nodes_begin();
  const MeshBase::node_iterator end = mesh.nodes_end();

  for (; it != end; ++it)
    {
      Node* node = *it;

      for (unsigned int i=0; i != LIBMESH_DIM; ++i)
        {
          // Expand the bounding box if necessary
          _lower_bound[i] = std::min(_lower_bound[i],
                                     (*node)(i));
          _upper_bound[i] = std::max(_upper_bound[i],
                                     (*node)(i));
        }
    }

  // On a parallel mesh we might not yet have a full bounding box
  if (!mesh.is_serial())
    {
      CommWorld.min(_lower_bound);
      CommWorld.max(_upper_bound);
    }

  this->fill(mesh);

  STOP_LOG("init()", "LocationMap");
}

void LocationMap<T>::init(MeshBase & mesh)
{
  // This function must be run on all processors at once
  // for non-serial meshes
  if (!mesh.is_serial())
    libmesh_parallel_only(mesh.comm());

  LOG_SCOPE("init()", "LocationMap");

  // Clear the old map
  _map.clear();

  // Cache a bounding box
  _lower_bound.clear();
  _lower_bound.resize(LIBMESH_DIM, std::numeric_limits<Real>::max());
  _upper_bound.clear();
  _upper_bound.resize(LIBMESH_DIM, -std::numeric_limits<Real>::max());

  for (auto & node : mesh.node_ptr_range())
    for (unsigned int i=0; i != LIBMESH_DIM; ++i)
      {
        // Expand the bounding box if necessary
        _lower_bound[i] = std::min(_lower_bound[i],
                                   (*node)(i));
        _upper_bound[i] = std::max(_upper_bound[i],
                                   (*node)(i));
      }

  // On a parallel mesh we might not yet have a full bounding box
  if (!mesh.is_serial())
    {
      mesh.comm().min(_lower_bound);
      mesh.comm().max(_upper_bound);
    }

  this->fill(mesh);
}

//--------------------------------------------------------------------------
void TopologyMap::init(MeshBase& mesh)
{
  // This function must be run on all processors at once
  // for non-serial meshes
  if (!mesh.is_serial())
    libmesh_parallel_only(mesh.comm());

  START_LOG("init()", "TopologyMap");

  // Clear the old map
  _map.clear();

  this->fill(mesh);

  STOP_LOG("init()", "TopologyMap");
}

void Partitioner::set_parent_processor_ids(MeshBase & mesh)
{
  // Ignore the parameter when !LIBMESH_ENABLE_AMR
  libmesh_ignore(mesh);

  LOG_SCOPE("set_parent_processor_ids()", "Partitioner");

#ifdef LIBMESH_ENABLE_AMR

  // If the mesh is serial we have access to all the elements,
  // in particular all the active ones.  We can therefore set
  // the parent processor ids indirecly through their children, and
  // set the subactive processor ids while examining their active
  // ancestors.
  // By convention a parent is assigned to the minimum processor
  // of all its children, and a subactive is assigned to the processor
  // of its active ancestor.
  if (mesh.is_serial())
    {
      // Loop over all the active elements in the mesh
      MeshBase::element_iterator       it  = mesh.active_elements_begin();
      const MeshBase::element_iterator end = mesh.active_elements_end();

      for ( ; it!=end; ++it)
        {
          Elem * child  = *it;

          // First set descendents

          std::vector<const Elem *> subactive_family;
          child->total_family_tree(subactive_family);
          for (unsigned int i = 0; i != subactive_family.size(); ++i)
            const_cast<Elem *>(subactive_family[i])->processor_id() = child->processor_id();

          // Then set ancestors

          Elem * parent = child->parent();

          while (parent)
            {
              // invalidate the parent id, otherwise the min below
              // will not work if the current parent id is less
              // than all the children!
              parent->invalidate_processor_id();

              for (unsigned int c=0; c<parent->n_children(); c++)
                {
                  child = parent->child_ptr(c);
                  libmesh_assert(child);
                  libmesh_assert(!child->is_remote());
                  libmesh_assert_not_equal_to (child->processor_id(), DofObject::invalid_processor_id);
                  parent->processor_id() = std::min(parent->processor_id(),
                                                    child->processor_id());
                }
              parent = parent->parent();
            }
        }
    }

  // When the mesh is parallel we cannot guarantee that parents have access to
  // all their children.
  else
    {
      // Setting subactive processor ids is easy: we can guarantee
      // that children have access to all their parents.

      // Loop over all the active elements in the mesh
      MeshBase::element_iterator       it  = mesh.active_elements_begin();
      const MeshBase::element_iterator end = mesh.active_elements_end();

      for ( ; it!=end; ++it)
        {
          Elem * child  = *it;

          std::vector<const Elem *> subactive_family;
          child->total_family_tree(subactive_family);
          for (unsigned int i = 0; i != subactive_family.size(); ++i)
            const_cast<Elem *>(subactive_family[i])->processor_id() = child->processor_id();
        }

      // When the mesh is parallel we cannot guarantee that parents have access to
      // all their children.

      // We will use a brute-force approach here.  Each processor finds its parent
      // elements and sets the parent pid to the minimum of its
      // semilocal descendants.
      // A global reduction is then performed to make sure the true minimum is found.
      // As noted, this is required because we cannot guarantee that a parent has
      // access to all its children on any single processor.
      libmesh_parallel_only(mesh.comm());
      libmesh_assert(MeshTools::n_elem(mesh.unpartitioned_elements_begin(),
                                       mesh.unpartitioned_elements_end()) == 0);

      const dof_id_type max_elem_id = mesh.max_elem_id();

      std::vector<processor_id_type>
        parent_processor_ids (std::min(communication_blocksize,
                                       max_elem_id));

      for (dof_id_type blk=0, last_elem_id=0; last_elem_id<max_elem_id; blk++)
//.........这里部分代码省略.........

void MetisPartitioner::partition_range(MeshBase & mesh,
                                       MeshBase::element_iterator beg,
                                       MeshBase::element_iterator end,
                                       unsigned int n_pieces)
{
  libmesh_assert_greater (n_pieces, 0);

  // We don't yet support distributed meshes with this Partitioner
  if (!mesh.is_serial())
    libmesh_not_implemented();

  // Check for an easy return
  if (n_pieces == 1)
    {
      this->single_partition_range (beg, end);
      return;
    }

  // What to do if the Metis library IS NOT present
#ifndef LIBMESH_HAVE_METIS

  libmesh_here();
  libMesh::err << "ERROR: The library has been built without"    << std::endl
               << "Metis support.  Using a space-filling curve"  << std::endl
               << "partitioner instead!"                         << std::endl;

  SFCPartitioner sfcp;
  sfcp.partition_range (mesh, beg, end, n_pieces);

  // What to do if the Metis library IS present
#else

  LOG_SCOPE("partition_range()", "MetisPartitioner");

  const dof_id_type n_range_elem = std::distance(beg, end);

  // Metis will only consider the elements in the range.
  // We need to map the range element ids into a
  // contiguous range.  Further, we want the unique range indexing to be
  // independent of the element ordering, otherwise a circular dependency
  // can result in which the partitioning depends on the ordering which
  // depends on the partitioning...
  vectormap<dof_id_type, dof_id_type> global_index_map;
  global_index_map.reserve (n_range_elem);

  {
    std::vector<dof_id_type> global_index;

    MeshCommunication().find_global_indices (mesh.comm(),
                                             MeshTools::create_bounding_box(mesh),
                                             beg, end, global_index);

    libmesh_assert_equal_to (global_index.size(), n_range_elem);

    MeshBase::element_iterator it = beg;
    for (std::size_t cnt=0; it != end; ++it)
      {
        const Elem * elem = *it;

        global_index_map.insert (std::make_pair(elem->id(), global_index[cnt++]));
      }
    libmesh_assert_equal_to (global_index_map.size(), n_range_elem);
  }

  // If we have boundary elements in this mesh, we want to account for
  // the connectivity between them and interior elements.  We can find
  // interior elements from boundary elements, but we need to build up
  // a lookup map to do the reverse.
  typedef std::unordered_multimap<const Elem *, const Elem *> map_type;
  map_type interior_to_boundary_map;

  {
    MeshBase::element_iterator it = beg;
    for (; it != end; ++it)
      {
        const Elem * elem = *it;

        // If we don't have an interior_parent then there's nothing
        // to look us up.
        if ((elem->dim() >= LIBMESH_DIM) ||
            !elem->interior_parent())
          continue;

        // get all relevant interior elements
        std::set<const Elem *> neighbor_set;
        elem->find_interior_neighbors(neighbor_set);

        std::set<const Elem *>::iterator n_it = neighbor_set.begin();
        for (; n_it != neighbor_set.end(); ++n_it)
          {
            // FIXME - non-const versions of the std::set<const Elem
            // *> returning methods would be nice
            Elem * neighbor = const_cast<Elem *>(*n_it);

#if defined(LIBMESH_HAVE_UNORDERED_MULTIMAP) ||         \
  defined(LIBMESH_HAVE_TR1_UNORDERED_MULTIMAP) ||       \
  defined(LIBMESH_HAVE_HASH_MULTIMAP) ||                \
  defined(LIBMESH_HAVE_EXT_HASH_MULTIMAP)
            interior_to_boundary_map.insert(std::make_pair(neighbor, elem));
#else
//.........这里部分代码省略.........

void CentroidPartitioner::partition_range(MeshBase & mesh,
                                          MeshBase::element_iterator it,
                                          MeshBase::element_iterator end,
                                          unsigned int n)
{
  // Check for an easy return
  if (n == 1)
    {
      this->single_partition_range (it, end);
      return;
    }

  // We don't yet support distributed meshes with this Partitioner
  if (!mesh.is_serial())
    libmesh_not_implemented();

  // Compute the element centroids.  Note: we used to skip this step
  // if the number of elements was unchanged from the last call, but
  // that doesn't account for elements that have moved a lot since the
  // last time the Partitioner was called...
  this->compute_centroids (it, end);

  switch (this->sort_method())
    {
    case X:
      {
        std::sort(_elem_centroids.begin(),
                  _elem_centroids.end(),
                  CentroidPartitioner::sort_x);

        break;
      }


    case Y:
      {
        std::sort(_elem_centroids.begin(),
                  _elem_centroids.end(),
                  CentroidPartitioner::sort_y);

        break;

      }


    case Z:
      {
        std::sort(_elem_centroids.begin(),
                  _elem_centroids.end(),
                  CentroidPartitioner::sort_z);

        break;
      }


    case RADIAL:
      {
        std::sort(_elem_centroids.begin(),
                  _elem_centroids.end(),
                  CentroidPartitioner::sort_radial);

        break;
      }
    default:
      libmesh_error_msg("Unknown sort method: " << this->sort_method());
    }

  // Make sure the user has not handed us an
  // invalid number of partitions.
  libmesh_assert_greater (n, 0);

  // Compute target_size, the approximate number of elements on each processor.
  const dof_id_type target_size = _elem_centroids.size() / n;

  for (dof_id_type i=0; i<_elem_centroids.size(); i++)
    {
      Elem * elem = _elem_centroids[i].second;

      // FIXME: All "extra" elements go on the last processor... this
      // could probably be improved.
      elem->processor_id() =
        std::min (cast_int<processor_id_type>(i / target_size),
                  cast_int<processor_id_type>(n-1));
    }
}

// ------------------------------------------------------------
// MetisPartitioner implementation
void MetisPartitioner::_do_partition (MeshBase& mesh,
				      const unsigned int n_pieces)
{
  libmesh_assert_greater (n_pieces, 0);
  libmesh_assert (mesh.is_serial());

  // Check for an easy return
  if (n_pieces == 1)
    {
      this->single_partition (mesh);
      return;
    }

// What to do if the Metis library IS NOT present
#ifndef LIBMESH_HAVE_METIS

  libmesh_here();
  libMesh::err << "ERROR: The library has been built without"    << std::endl
	        << "Metis support.  Using a space-filling curve"  << std::endl
	        << "partitioner instead!"                         << std::endl;

  SFCPartitioner sfcp;

  sfcp.partition (mesh, n_pieces);

// What to do if the Metis library IS present
#else

  START_LOG("partition()", "MetisPartitioner");

  const dof_id_type n_active_elem = mesh.n_active_elem();

  // build the graph
  // std::vector<int> options(5);
  std::vector<int> vwgt(n_active_elem);
  std::vector<int> part(n_active_elem);

  int
    n = static_cast<int>(n_active_elem),  // number of "nodes" (elements)
                                          //   in the graph
//    wgtflag = 2,                          // weights on vertices only,
//                                          //   none on edges
//    numflag = 0,                          // C-style 0-based numbering
    nparts  = static_cast<int>(n_pieces), // number of subdomains to create
    edgecut = 0;                          // the numbers of edges cut by the
                                          //   resulting partition

  // Set the options
  // options[0] = 0; // use default options

  // Metis will only consider the active elements.
  // We need to map the active element ids into a
  // contiguous range.  Further, we want the unique range indexing to be
  // independednt of the element ordering, otherwise a circular dependency
  // can result in which the partitioning depends on the ordering which
  // depends on the partitioning...
  std::map<const Elem*, dof_id_type> global_index_map;
  {
    std::vector<dof_id_type> global_index;

    MeshBase::element_iterator       it  = mesh.active_elements_begin();
    const MeshBase::element_iterator end = mesh.active_elements_end();

    MeshCommunication().find_global_indices (MeshTools::bounding_box(mesh),
					     it, end, global_index);

    libmesh_assert_equal_to (global_index.size(), n_active_elem);

    for (std::size_t cnt=0; it != end; ++it)
      {
	const Elem *elem = *it;
	libmesh_assert (!global_index_map.count(elem));

	global_index_map[elem]  = global_index[cnt++];
      }
    libmesh_assert_equal_to (global_index_map.size(), n_active_elem);
  }


  // build the graph in CSR format.  Note that
  // the edges in the graph will correspond to
  // face neighbors
  std::vector<int> xadj, adjncy;
  {
    std::vector<const Elem*> neighbors_offspring;

    MeshBase::element_iterator       elem_it  = mesh.active_elements_begin();
    const MeshBase::element_iterator elem_end = mesh.active_elements_end();

    // This will be exact when there is no refinement and all the
    // elements are of the same type.
    std::size_t graph_size=0;
    std::vector<std::vector<dof_id_type> > graph(n_active_elem);

    for (; elem_it != elem_end; ++elem_it)
      {
	const Elem* elem = *elem_it;

//.........这里部分代码省略.........