Reference documentation for deal.II version GIT b6bf1e606d 2022-08-11 15:25:02+00:00
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mpi_remote_point_evaluation.cc
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2 //
3 // Copyright (C) 2021 - 2022 by the deal.II authors
4 //
5 // This file is part of the deal.II library.
6 //
7 // The deal.II library is free software; you can use it, redistribute
8 // it, and/or modify it under the terms of the GNU Lesser General
9 // Public License as published by the Free Software Foundation; either
10 // version 2.1 of the License, or (at your option) any later version.
11 // The full text of the license can be found in the file LICENSE.md at
12 // the top level directory of deal.II.
13 //
14 // ---------------------------------------------------------------------
15 
16 #include <deal.II/base/config.h>
17 
21 
23 
24 #include <deal.II/fe/mapping.h>
25 
29 #include <deal.II/grid/tria.h>
30 
32 
33 
34 namespace Utilities
35 {
36  namespace MPI
37  {
38  template <int dim, int spacedim>
40  const double tolerance,
41  const bool enforce_unique_mapping,
42  const unsigned int rtree_level,
43  const std::function<std::vector<bool>()> &marked_vertices)
44  : tolerance(tolerance)
45  , enforce_unique_mapping(enforce_unique_mapping)
46  , rtree_level(rtree_level)
47  , marked_vertices(marked_vertices)
48  , ready_flag(false)
49  {}
50 
51 
52 
53  template <int dim, int spacedim>
55  {
56  if (tria_signal.connected())
57  tria_signal.disconnect();
58  }
59 
60 
61 
62  template <int dim, int spacedim>
63  void
65  const std::vector<Point<spacedim>> &points,
67  const Mapping<dim, spacedim> & mapping)
68  {
69 #ifndef DEAL_II_WITH_MPI
70  Assert(false, ExcNeedsMPI());
71  (void)points;
72  (void)tria;
73  (void)mapping;
74 #else
75  if (tria_signal.connected())
76  tria_signal.disconnect();
77 
78  tria_signal =
79  tria.signals.any_change.connect([&]() { this->ready_flag = false; });
80 
81  this->tria = &tria;
82  this->mapping = &mapping;
83 
84  std::vector<BoundingBox<spacedim>> local_boxes;
85  for (const auto &cell :
87  local_boxes.push_back(mapping.get_bounding_box(cell));
88 
89  // create r-tree of bounding boxes
90  const auto local_tree = pack_rtree(local_boxes);
91 
92  // compress r-tree to a minimal set of bounding boxes
93  const auto local_reduced_box =
94  extract_rtree_level(local_tree, rtree_level);
95 
96  // gather bounding boxes of other processes
97  const auto global_bboxes =
98  Utilities::MPI::all_gather(tria.get_communicator(), local_reduced_box);
99 
100  const GridTools::Cache<dim, spacedim> cache(tria, mapping);
101 
102  const auto data =
104  cache,
105  points,
106  global_bboxes,
107  marked_vertices ? marked_vertices() : std::vector<bool>(),
108  tolerance,
109  true,
110  enforce_unique_mapping);
111 
112  this->recv_ranks = data.recv_ranks;
113  this->recv_ptrs = data.recv_ptrs;
114 
115  this->send_ranks = data.send_ranks;
116  this->send_ptrs = data.send_ptrs;
117 
118  this->recv_permutation = {};
119  this->recv_permutation.resize(data.recv_components.size());
120  this->point_ptrs.assign(points.size() + 1, 0);
121  for (unsigned int i = 0; i < data.recv_components.size(); ++i)
122  {
123  AssertIndexRange(std::get<2>(data.recv_components[i]),
124  this->recv_permutation.size());
125  this->recv_permutation[std::get<2>(data.recv_components[i])] = i;
126 
127  AssertIndexRange(std::get<1>(data.recv_components[i]) + 1,
128  this->point_ptrs.size());
129  this->point_ptrs[std::get<1>(data.recv_components[i]) + 1]++;
130  }
131 
132  std::tuple<unsigned int, unsigned int> n_owning_processes_default{
134  std::tuple<unsigned int, unsigned int> n_owning_processes_local =
135  n_owning_processes_default;
136 
137  for (unsigned int i = 0; i < points.size(); ++i)
138  {
139  std::get<0>(n_owning_processes_local) =
140  std::min(std::get<0>(n_owning_processes_local),
141  this->point_ptrs[i + 1]);
142  std::get<1>(n_owning_processes_local) =
143  std::max(std::get<1>(n_owning_processes_local),
144  this->point_ptrs[i + 1]);
145 
146  this->point_ptrs[i + 1] += this->point_ptrs[i];
147  }
148 
149  const auto n_owning_processes_global =
150  Utilities::MPI::all_reduce<std::tuple<unsigned int, unsigned int>>(
151  n_owning_processes_local,
153  [&](const auto &a,
154  const auto &b) -> std::tuple<unsigned int, unsigned int> {
155  if (a == n_owning_processes_default)
156  return b;
157 
158  if (b == n_owning_processes_default)
159  return a;
160 
161  return std::tuple<unsigned int, unsigned int>{
162  std::min(std::get<0>(a), std::get<0>(b)),
163  std::max(std::get<1>(a), std::get<1>(b))};
164  });
165 
166  if (n_owning_processes_global == n_owning_processes_default)
167  {
168  unique_mapping = true;
169  all_points_found_flag = true;
170  }
171  else
172  {
173  unique_mapping = (std::get<0>(n_owning_processes_global) == 1) &&
174  (std::get<1>(n_owning_processes_global) == 1);
175  all_points_found_flag = std::get<0>(n_owning_processes_global) > 0;
176  }
177 
178  Assert(enforce_unique_mapping == false || unique_mapping,
179  ExcInternalError());
180 
181  cell_data = {};
182  send_permutation = {};
183 
184  std::pair<int, int> dummy{-1, -1};
185  for (const auto &i : data.send_components)
186  {
187  if (dummy != std::get<0>(i))
188  {
189  dummy = std::get<0>(i);
190  cell_data.cells.emplace_back(dummy);
191  cell_data.reference_point_ptrs.emplace_back(
192  cell_data.reference_point_values.size());
193  }
194 
195  cell_data.reference_point_values.emplace_back(std::get<3>(i));
196  send_permutation.emplace_back(std::get<5>(i));
197  }
198 
199  cell_data.reference_point_ptrs.emplace_back(
200  cell_data.reference_point_values.size());
201 
202  this->ready_flag = true;
203 #endif
204  }
205 
206 
207  template <int dim, int spacedim>
208  const std::vector<unsigned int> &
210  {
211  return point_ptrs;
212  }
213 
214 
215 
216  template <int dim, int spacedim>
217  bool
219  {
220  return unique_mapping;
221  }
222 
223 
224 
225  template <int dim, int spacedim>
226  bool
228  {
229  return all_points_found_flag;
230  }
231 
232 
233 
234  template <int dim, int spacedim>
235  bool
237  const unsigned int i) const
238  {
239  AssertIndexRange(i, point_ptrs.size() - 1);
240 
241  if (all_points_found_flag)
242  return true;
243  else
244  return (point_ptrs[i + 1] - point_ptrs[i]) > 0;
245  }
246 
247 
248 
249  template <int dim, int spacedim>
252  {
253  return *tria;
254  }
255 
256 
257 
258  template <int dim, int spacedim>
259  const Mapping<dim, spacedim> &
261  {
262  return *mapping;
263  }
264 
265 
266 
267  template <int dim, int spacedim>
268  bool
270  {
271  return ready_flag;
272  }
273 
274  } // end of namespace MPI
275 } // end of namespace Utilities
276 
277 #include "mpi_remote_point_evaluation.inst"
278 
virtual BoundingBox< spacedim > get_bounding_box(const typename Triangulation< dim, spacedim >::cell_iterator &cell) const
virtual MPI_Comm get_communicator() const
Signals signals
Definition: tria.h:2448
RemotePointEvaluation(const double tolerance=1e-6, const bool enforce_unique_mapping=false, const unsigned int rtree_level=0, const std::function< std::vector< bool >()> &marked_vertices={})
#define DEAL_II_NAMESPACE_OPEN
Definition: config.h:442
#define DEAL_II_NAMESPACE_CLOSE
Definition: config.h:443
IteratorRange< active_cell_iterator > active_cell_iterators() const
static ::ExceptionBase & ExcInternalError()
static ::ExceptionBase & ExcNeedsMPI()
#define Assert(cond, exc)
Definition: exceptions.h:1473
#define AssertIndexRange(index, range)
Definition: exceptions.h:1732
DistributedComputePointLocationsInternal< dim, spacedim > distributed_compute_point_locations(const GridTools::Cache< dim, spacedim > &cache, const std::vector< Point< spacedim >> &points, const std::vector< std::vector< BoundingBox< spacedim >>> &global_bboxes, const std::vector< bool > &marked_vertices, const double tolerance, const bool perform_handshake, const bool enforce_unique_mapping=false)
Definition: grid_tools.cc:5973
SymmetricTensor< 2, dim, Number > b(const Tensor< 2, dim, Number > &F)
std::vector< T > all_gather(const MPI_Comm &comm, const T &object_to_send)
void reinit(MatrixBlock< MatrixType > &v, const BlockSparsityPattern &p)
Definition: matrix_block.h:618
static const unsigned int invalid_unsigned_int
Definition: types.h:201
std::vector< BoundingBox< boost::geometry::dimension< typename Rtree::indexable_type >::value > > extract_rtree_level(const Rtree &tree, const unsigned int level)
RTree< typename LeafTypeIterator::value_type, IndexType, IndexableGetter > pack_rtree(const LeafTypeIterator &begin, const LeafTypeIterator &end)
const ::Triangulation< dim, spacedim > & tria