Reference documentation for deal.II version GIT relicensing-136-gb80d0be4af 2024-03-18 08:20:02+00:00
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tria_base.cc
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1// ------------------------------------------------------------------------
2//
3// SPDX-License-Identifier: LGPL-2.1-or-later
4// Copyright (C) 2015 - 2024 by the deal.II authors
5//
6// This file is part of the deal.II library.
7//
8// Part of the source code is dual licensed under Apache-2.0 WITH
9// LLVM-exception OR LGPL-2.1-or-later. Detailed license information
10// governing the source code and code contributions can be found in
11// LICENSE.md and CONTRIBUTING.md at the top level directory of deal.II.
12//
13// ------------------------------------------------------------------------
14
15
18#include <deal.II/base/mpi.templates.h>
21
24
27#include <deal.II/grid/tria.h>
30
32
33#include <algorithm>
34#include <cstdint>
35#include <fstream>
36#include <iostream>
37#include <limits>
38#include <numeric>
39
40
42
43namespace parallel
44{
45 template <int dim, int spacedim>
48 const MPI_Comm mpi_communicator,
49 const typename ::Triangulation<dim, spacedim>::MeshSmoothing
50 smooth_grid,
51 const bool check_for_distorted_cells)
52 : ::Triangulation<dim, spacedim>(smooth_grid,
53 check_for_distorted_cells)
54 , mpi_communicator(mpi_communicator)
55 , my_subdomain(Utilities::MPI::this_mpi_process(this->mpi_communicator))
56 , n_subdomains(Utilities::MPI::n_mpi_processes(this->mpi_communicator))
57 {
58#ifndef DEAL_II_WITH_MPI
59 Assert(false, ExcNeedsMPI());
60#endif
61 }
62
63
64
65 template <int dim, int spacedim>
67 void TriangulationBase<dim, spacedim>::copy_triangulation(
68 const ::Triangulation<dim, spacedim> &other_tria)
69 {
70#ifndef DEAL_II_WITH_MPI
71 (void)other_tria;
72 Assert(false, ExcNeedsMPI());
73#else
75
76 if (const ::parallel::TriangulationBase<dim, spacedim> *other_tria_x =
77 dynamic_cast<const ::parallel::TriangulationBase<dim, spacedim>
78 *>(&other_tria))
79 {
80 // release unused vector memory because we will have very different
81 // vectors now
84 }
85#endif
86 }
87
88
89
90 template <int dim, int spacedim>
92 std::size_t TriangulationBase<dim, spacedim>::memory_consumption() const
93 {
94 std::size_t mem =
96 MemoryConsumption::memory_consumption(this->mpi_communicator) +
99 number_cache.n_global_active_cells) +
100 MemoryConsumption::memory_consumption(number_cache.n_global_levels);
101 return mem;
102 }
103
104
105
106 template <int dim, int spacedim>
109 {
110 // release unused vector memory because the vector layout is going to look
111 // very different now
114 }
115
116
118 template <int dim, int spacedim>
121 : n_locally_owned_active_cells(0)
122 , n_global_active_cells(0)
123 , number_of_global_coarse_cells(0)
124 , n_global_levels(0)
125 {}
126
127
128
129 template <int dim, int spacedim>
131 unsigned int TriangulationBase<dim, spacedim>::n_locally_owned_active_cells()
132 const
133 {
134 return number_cache.n_locally_owned_active_cells;
135 }
136
137
138
139 template <int dim, int spacedim>
141 unsigned int TriangulationBase<dim, spacedim>::n_global_levels() const
142 {
143 return number_cache.n_global_levels;
144 }
145
146
148 template <int dim, int spacedim>
152 {
153 return number_cache.n_global_active_cells;
154 }
155
156
157
158 template <int dim, int spacedim>
160 MPI_Comm TriangulationBase<dim, spacedim>::get_communicator() const
161 {
162 return mpi_communicator;
163 }
165
166
167#ifdef DEAL_II_WITH_MPI
168 template <int dim, int spacedim>
170 void TriangulationBase<dim, spacedim>::update_number_cache()
171 {
172 number_cache.ghost_owners.clear();
173 number_cache.level_ghost_owners.clear();
174 number_cache.n_locally_owned_active_cells = 0;
175
176 if (this->n_levels() == 0)
177 {
178 // Skip communication done below if we do not have any cells
179 // (meaning the Triangulation is empty on all processors). This will
180 // happen when called from the destructor of Triangulation, which
181 // can get called during exception handling causing a hang in this
182 // function.
183 number_cache.n_global_active_cells = 0;
184 number_cache.n_global_levels = 0;
185 return;
186 }
187
188
189 {
190 // find ghost owners
191 for (const auto &cell : this->active_cell_iterators())
192 if (cell->is_ghost())
193 number_cache.ghost_owners.insert(cell->subdomain_id());
194
195 Assert(number_cache.ghost_owners.size() <
196 Utilities::MPI::n_mpi_processes(this->mpi_communicator),
198 }
199
200 if (this->n_levels() > 0)
201 number_cache.n_locally_owned_active_cells = std::count_if(
202 this->begin_active(),
204 this->end()),
205 [](const auto &i) { return i.is_locally_owned(); });
206 else
207 number_cache.n_locally_owned_active_cells = 0;
208
209 // Potentially cast to a 64 bit type before accumulating to avoid
210 // overflow:
211 number_cache.n_global_active_cells =
213 number_cache.n_locally_owned_active_cells),
214 this->mpi_communicator);
215
216 number_cache.n_global_levels =
217 Utilities::MPI::max(this->n_levels(), this->mpi_communicator);
218
219 // Store MPI ranks of level ghost owners of this processor on all
220 // levels.
221 if (this->is_multilevel_hierarchy_constructed() == true)
222 {
223 number_cache.level_ghost_owners.clear();
224
225 // if there is nothing to do, then do nothing
226 if (this->n_levels() == 0)
227 return;
229 // find level ghost owners
230 for (const auto &cell : this->cell_iterators())
231 if (cell->level_subdomain_id() != numbers::artificial_subdomain_id &&
232 cell->level_subdomain_id() != this->locally_owned_subdomain())
233 this->number_cache.level_ghost_owners.insert(
234 cell->level_subdomain_id());
235
236# ifdef DEBUG
237 // Check that level_ghost_owners is symmetric by sending a message
238 // to everyone
239 {
240 int ierr = MPI_Barrier(this->mpi_communicator);
241 AssertThrowMPI(ierr);
242
243 const int mpi_tag = Utilities::MPI::internal::Tags::
245
246 // important: preallocate to avoid (re)allocation:
247 std::vector<MPI_Request> requests(
248 this->number_cache.level_ghost_owners.size());
249 unsigned int dummy = 0;
250 unsigned int req_counter = 0;
251
252 for (const auto &it : this->number_cache.level_ghost_owners)
253 {
254 ierr = MPI_Isend(&dummy,
255 1,
256 MPI_UNSIGNED,
257 it,
258 mpi_tag,
259 this->mpi_communicator,
260 &requests[req_counter]);
261 AssertThrowMPI(ierr);
262 ++req_counter;
263 }
264
265 for (const auto &it : this->number_cache.level_ghost_owners)
266 {
267 unsigned int dummy;
268 ierr = MPI_Recv(&dummy,
269 1,
270 MPI_UNSIGNED,
271 it,
272 mpi_tag,
273 this->mpi_communicator,
274 MPI_STATUS_IGNORE);
275 AssertThrowMPI(ierr);
276 }
277
278 if (requests.size() > 0)
279 {
280 ierr = MPI_Waitall(requests.size(),
281 requests.data(),
282 MPI_STATUSES_IGNORE);
283 AssertThrowMPI(ierr);
284 }
285
286 ierr = MPI_Barrier(this->mpi_communicator);
287 AssertThrowMPI(ierr);
288 }
289# endif
290
291 Assert(this->number_cache.level_ghost_owners.size() <
292 Utilities::MPI::n_mpi_processes(this->mpi_communicator),
294 }
295
296 this->number_cache.number_of_global_coarse_cells = this->n_cells(0);
297
298 // reset global cell ids
299 this->reset_global_cell_indices();
300 }
302#else
303
304 template <int dim, int spacedim>
307 {
308 Assert(false, ExcNeedsMPI());
309 }
310
311#endif
312
313 template <int dim, int spacedim>
315 void TriangulationBase<dim, spacedim>::update_reference_cells()
316 {
317 // run algorithm for locally-owned cells
319
320 // translate ReferenceCell to unsigned int (needed by
321 // Utilities::MPI::compute_set_union)
322 std::vector<unsigned int> reference_cells_ui;
323
324 reference_cells_ui.reserve(this->reference_cells.size());
325 for (const auto &i : this->reference_cells)
326 reference_cells_ui.push_back(static_cast<unsigned int>(i));
327
328 // create union
329 reference_cells_ui =
330 Utilities::MPI::compute_set_union(reference_cells_ui,
331 this->mpi_communicator);
332
333 // transform back and store result
334 this->reference_cells.clear();
335 for (const auto &i : reference_cells_ui)
336 this->reference_cells.emplace_back(
338 }
339
340
341
342 template <int dim, int spacedim>
346 {
347 return my_subdomain;
348 }
349
350
351
352 template <int dim, int spacedim>
354 const std::set<types::subdomain_id>
356 {
357 return number_cache.ghost_owners;
358 }
359
360
361
362 template <int dim, int spacedim>
364 const std::set<types::subdomain_id>
366 {
367 return number_cache.level_ghost_owners;
368 }
369
370
371
372 template <int dim, int spacedim>
374 std::vector<types::boundary_id> TriangulationBase<dim, spacedim>::
375 get_boundary_ids() const
376 {
379 this->mpi_communicator);
380 }
381
382
383
384 template <int dim, int spacedim>
386 std::vector<types::manifold_id> TriangulationBase<dim, spacedim>::
387 get_manifold_ids() const
391 this->mpi_communicator);
392 }
393
394
395
396 template <int dim, int spacedim>
398 void TriangulationBase<dim, spacedim>::reset_global_cell_indices()
399 {
400#ifndef DEAL_II_WITH_MPI
401 Assert(false, ExcNeedsMPI());
402#else
403 if (const auto pst =
405 this))
406 if (pst->with_artificial_cells() == false)
407 {
408 // Specialization for parallel::shared::Triangulation without
409 // artificial cells. The code below only works if a halo of a single
410 // ghost cells is needed.
411
412 std::vector<unsigned int> cell_counter(n_subdomains + 1);
413
414 // count number of cells of each process
415 for (const auto &cell : this->active_cell_iterators())
416 cell_counter[cell->subdomain_id() + 1]++;
417
418 // take prefix sum to obtain offset of each process
419 for (unsigned int i = 0; i < n_subdomains; ++i)
420 cell_counter[i + 1] += cell_counter[i];
421
422 AssertDimension(cell_counter.back(), this->n_active_cells());
423
424 // create partitioners
425 IndexSet is_local(this->n_active_cells());
426 is_local.add_range(cell_counter[my_subdomain],
427 cell_counter[my_subdomain + 1]);
428 number_cache.active_cell_index_partitioner =
429 std::make_shared<const Utilities::MPI::Partitioner>(
430 is_local,
431 complete_index_set(this->n_active_cells()),
432 this->mpi_communicator);
433
434 // set global active cell indices and increment process-local counters
435 for (const auto &cell : this->active_cell_iterators())
436 cell->set_global_active_cell_index(
437 cell_counter[cell->subdomain_id()]++);
438
439 Assert(this->is_multilevel_hierarchy_constructed() == false,
441
442 return;
443 }
444
445 // 1) determine number of active locally-owned cells
446 const types::global_cell_index n_locally_owned_cells =
447 this->n_locally_owned_active_cells();
448
449 // 2) determine the offset of each process
451
452 const int ierr = MPI_Exscan(
453 &n_locally_owned_cells,
454 &cell_index,
455 1,
456 Utilities::MPI::mpi_type_id_for_type<decltype(n_locally_owned_cells)>,
457 MPI_SUM,
458 this->mpi_communicator);
459 AssertThrowMPI(ierr);
460
461 // 3) give global indices to locally-owned cells and mark all other cells as
462 // invalid
463 std::pair<types::global_cell_index, types::global_cell_index> my_range;
464 my_range.first = cell_index;
465
466 for (const auto &cell : this->active_cell_iterators())
467 if (cell->is_locally_owned())
468 cell->set_global_active_cell_index(cell_index++);
469 else
470 cell->set_global_active_cell_index(numbers::invalid_dof_index);
471
472 my_range.second = cell_index;
473
474 // 4) determine the global indices of ghost cells
475 std::vector<types::global_dof_index> is_ghost_vector;
476 GridTools::exchange_cell_data_to_ghosts<types::global_cell_index>(
477 static_cast<::Triangulation<dim, spacedim> &>(*this),
478 [](const auto &cell) { return cell->global_active_cell_index(); },
479 [&is_ghost_vector](const auto &cell, const auto &id) {
480 cell->set_global_active_cell_index(id);
481 is_ghost_vector.push_back(id);
482 });
483
484 // 5) set up new partitioner
485 IndexSet is_local(this->n_global_active_cells());
486 is_local.add_range(my_range.first, my_range.second);
487
488 std::sort(is_ghost_vector.begin(), is_ghost_vector.end());
489 IndexSet is_ghost(this->n_global_active_cells());
490 is_ghost.add_indices(is_ghost_vector.begin(), is_ghost_vector.end());
492 number_cache.active_cell_index_partitioner =
493 std::make_shared<const Utilities::MPI::Partitioner>(
494 is_local, is_ghost, this->mpi_communicator);
495
496 // 6) proceed with multigrid levels if requested
497 if (this->is_multilevel_hierarchy_constructed() == true)
498 {
499 // 1) determine number of locally-owned cells on levels
500 std::vector<types::global_cell_index> n_cells_level(
501 this->n_global_levels(), 0);
502
503 for (auto cell : this->cell_iterators())
504 if (cell->level_subdomain_id() == this->locally_owned_subdomain())
505 n_cells_level[cell->level()]++;
506
507 // 2) determine the offset of each process
508 std::vector<types::global_cell_index> cell_index(
509 this->n_global_levels(), 0);
510
511 int ierr = MPI_Exscan(
512 n_cells_level.data(),
513 cell_index.data(),
514 this->n_global_levels(),
515 Utilities::MPI::mpi_type_id_for_type<decltype(*n_cells_level.data())>,
516 MPI_SUM,
517 this->mpi_communicator);
518 AssertThrowMPI(ierr);
519
520 // 3) determine global number of "active" cells on each level
521 Utilities::MPI::sum(n_cells_level,
522 this->mpi_communicator,
523 n_cells_level);
524
525 // 4) give global indices to locally-owned cells on level and mark
526 // all other cells as invalid
527 std::vector<
528 std::pair<types::global_cell_index, types::global_cell_index>>
529 my_ranges(this->n_global_levels());
530 for (unsigned int l = 0; l < this->n_global_levels(); ++l)
531 my_ranges[l].first = cell_index[l];
532
533 for (auto cell : this->cell_iterators())
534 if (cell->level_subdomain_id() == this->locally_owned_subdomain())
535 cell->set_global_level_cell_index(cell_index[cell->level()]++);
536 else
537 cell->set_global_level_cell_index(numbers::invalid_dof_index);
538
539 for (unsigned int l = 0; l < this->n_global_levels(); ++l)
540 my_ranges[l].second = cell_index[l];
541
542 // 5) update the numbers of ghost level cells
543 std::vector<std::vector<types::global_dof_index>> is_ghost_vectors(
544 this->n_global_levels());
548 *this,
549 [](const auto &cell) { return cell->global_level_cell_index(); },
550 [&is_ghost_vectors](const auto &cell, const auto &id) {
551 cell->set_global_level_cell_index(id);
552 is_ghost_vectors[cell->level()].push_back(id);
553 });
554
555 number_cache.level_cell_index_partitioners.resize(
556 this->n_global_levels());
557
558 // 6) set up cell partitioners for each level
559 for (unsigned int l = 0; l < this->n_global_levels(); ++l)
560 {
561 IndexSet is_local(n_cells_level[l]);
562 is_local.add_range(my_ranges[l].first, my_ranges[l].second);
563
564 IndexSet is_ghost(n_cells_level[l]);
565 std::sort(is_ghost_vectors[l].begin(), is_ghost_vectors[l].end());
566 is_ghost.add_indices(is_ghost_vectors[l].begin(),
567 is_ghost_vectors[l].end());
568
569 number_cache.level_cell_index_partitioners[l] =
570 std::make_shared<const Utilities::MPI::Partitioner>(
571 is_local, is_ghost, this->mpi_communicator);
572 }
573 }
574
575#endif
576 }
577
578
579
580 template <int dim, int spacedim>
582 void TriangulationBase<dim, spacedim>::communicate_locally_moved_vertices(
583 const std::vector<bool> &vertex_locally_moved)
584 {
585 AssertDimension(vertex_locally_moved.size(), this->n_vertices());
586#ifdef DEBUG
587 {
588 const std::vector<bool> locally_owned_vertices =
590 for (unsigned int i = 0; i < locally_owned_vertices.size(); ++i)
591 Assert((vertex_locally_moved[i] == false) ||
592 (locally_owned_vertices[i] == true),
593 ExcMessage("The vertex_locally_moved argument must not "
594 "contain vertices that are not locally owned"));
595 }
596#endif
597
598 Point<spacedim> invalid_point;
599 for (unsigned int d = 0; d < spacedim; ++d)
600 invalid_point[d] = std::numeric_limits<double>::quiet_NaN();
601
602 const auto pack = [&](const auto &cell) {
603 std::vector<Point<spacedim>> vertices(cell->n_vertices());
604
605 for (const auto v : cell->vertex_indices())
606 if (vertex_locally_moved[cell->vertex_index(v)])
607 vertices[v] = cell->vertex(v);
608 else
609 vertices[v] = invalid_point;
610
611 return vertices;
612 };
613
614 const auto unpack = [&](const auto &cell, const auto &vertices) {
615 for (const auto v : cell->vertex_indices())
616 if (numbers::is_nan(vertices[v][0]) == false)
617 cell->vertex(v) = vertices[v];
618 };
619
620 if (this->is_multilevel_hierarchy_constructed())
622 std::vector<Point<spacedim>>>(
623 static_cast<::Triangulation<dim, spacedim> &>(*this),
624 pack,
625 unpack);
626 else
627 GridTools::exchange_cell_data_to_ghosts<std::vector<Point<spacedim>>>(
628 static_cast<::Triangulation<dim, spacedim> &>(*this),
629 pack,
630 unpack);
631 }
632
633
634
635 template <int dim, int spacedim>
637 std::weak_ptr<const Utilities::MPI::Partitioner> TriangulationBase<
638 dim,
639 spacedim>::global_active_cell_index_partitioner() const
640 {
641 return number_cache.active_cell_index_partitioner;
642 }
643
644
645
646 template <int dim, int spacedim>
648 std::weak_ptr<const Utilities::MPI::Partitioner> TriangulationBase<dim,
649 spacedim>::
650 global_level_cell_index_partitioner(const unsigned int level) const
651 {
652 Assert(this->is_multilevel_hierarchy_constructed(), ExcNotImplemented());
653 AssertIndexRange(level, this->n_global_levels());
654
655 return number_cache.level_cell_index_partitioners[level];
656 }
657
658
659
660 template <int dim, int spacedim>
664 {
665 return number_cache.number_of_global_coarse_cells;
666 }
667
668
669
670 template <int dim, int spacedim>
673 const MPI_Comm mpi_communicator,
674 const typename ::Triangulation<dim, spacedim>::MeshSmoothing
675 smooth_grid,
676 const bool check_for_distorted_cells)
677 : ::parallel::TriangulationBase<dim, spacedim>(
678 mpi_communicator,
679 smooth_grid,
680 check_for_distorted_cells)
681 {}
682
683
684
685 template <int dim, int spacedim>
687 void DistributedTriangulationBase<dim, spacedim>::clear()
688 {
690 }
691
692
693
694 template <int dim, int spacedim>
696 bool DistributedTriangulationBase<dim, spacedim>::has_hanging_nodes() const
697 {
698 if (this->n_global_levels() <= 1)
699 return false; // can not have hanging nodes without refined cells
700
701 // if there are any active cells with level less than n_global_levels()-1,
702 // then there is obviously also one with level n_global_levels()-1, and
703 // consequently there must be a hanging node somewhere.
704 //
705 // The problem is that we cannot just ask for the first active cell, but
706 // instead need to filter over locally owned cells.
707 const bool have_coarser_cell =
708 std::any_of(this->begin_active(this->n_global_levels() - 2),
709 this->end_active(this->n_global_levels() - 2),
710 [](const CellAccessor<dim, spacedim> &cell) {
711 return cell.is_locally_owned();
712 });
713
714 // return true if at least one process has a coarser cell
715 return Utilities::MPI::max(have_coarser_cell ? 1 : 0,
716 this->mpi_communicator) != 0;
717 }
718
719
720} // end namespace parallel
721
722
723
724/*-------------- Explicit Instantiations -------------------------------*/
725#include "tria_base.inst"
726
bool is_locally_owned() const
void add_range(const size_type begin, const size_type end)
Definition index_set.h:1792
Definition point.h:111
virtual void clear()
virtual void copy_triangulation(const Triangulation< dim, spacedim > &other_tria)
virtual std::size_t memory_consumption() const
virtual void update_reference_cells()
const std::set< types::subdomain_id > & level_ghost_owners() const
Definition tria_base.cc:365
virtual types::global_cell_index n_global_active_cells() const override
Definition tria_base.cc:151
const std::set< types::subdomain_id > & ghost_owners() const
Definition tria_base.cc:355
types::subdomain_id locally_owned_subdomain() const override
Definition tria_base.cc:345
virtual unsigned int n_global_levels() const override
Definition tria_base.cc:141
unsigned int n_locally_owned_active_cells() const
Definition tria_base.cc:131
virtual types::coarse_cell_id n_global_coarse_cells() const override
Definition tria_base.cc:663
virtual void update_number_cache()
Definition tria_base.cc:170
#define DEAL_II_NAMESPACE_OPEN
Definition config.h:502
#define DEAL_II_CXX20_REQUIRES(condition)
Definition config.h:177
#define DEAL_II_NAMESPACE_CLOSE
Definition config.h:503
Point< 3 > vertices[4]
Point< 2 > second
Definition grid_out.cc:4614
Point< 2 > first
Definition grid_out.cc:4613
unsigned int level
Definition grid_out.cc:4616
unsigned int cell_index
static ::ExceptionBase & ExcNotImplemented()
static ::ExceptionBase & ExcNeedsMPI()
#define Assert(cond, exc)
#define AssertDimension(dim1, dim2)
#define AssertThrowMPI(error_code)
#define AssertIndexRange(index, range)
static ::ExceptionBase & ExcInternalError()
static ::ExceptionBase & ExcMessage(std::string arg1)
IndexSet complete_index_set(const IndexSet::size_type N)
Definition index_set.h:1193
std::vector< bool > get_locally_owned_vertices(const Triangulation< dim, spacedim > &triangulation)
void exchange_cell_data_to_level_ghosts(const MeshType &mesh, const std::function< std::optional< DataType >(const typename MeshType::level_cell_iterator &)> &pack, const std::function< void(const typename MeshType::level_cell_iterator &, const DataType &)> &unpack, const std::function< bool(const typename MeshType::level_cell_iterator &)> &cell_filter=always_return< typename MeshType::level_cell_iterator, bool >{ true})
std::enable_if_t< std::is_fundamental_v< T >, std::size_t > memory_consumption(const T &t)
@ triangulation_base_fill_level_ghost_owners
TriangulationBase<dim, spacedim>::fill_level_ghost_owners()
Definition mpi_tags.h:101
T sum(const T &t, const MPI_Comm mpi_communicator)
unsigned int n_mpi_processes(const MPI_Comm mpi_communicator)
Definition mpi.cc:128
T max(const T &t, const MPI_Comm mpi_communicator)
std::vector< T > compute_set_union(const std::vector< T > &vec, const MPI_Comm comm)
const MPI_Datatype mpi_type_id_for_type
Definition mpi.h:1747
unsigned int n_cells(const internal::TriangulationImplementation::NumberCache< 1 > &c)
Definition tria.cc:14903
constexpr ReferenceCell make_reference_cell_from_int(const std::uint8_t kind)
const types::global_dof_index invalid_dof_index
Definition types.h:252
bool is_nan(const double x)
Definition numbers.h:530
const Iterator const std_cxx20::type_identity_t< Iterator > & end
Definition parallel.h:610
const Iterator & begin
Definition parallel.h:609
STL namespace.
Definition types.h:32
unsigned int global_cell_index
Definition types.h:121