#include <deal.II/base/mpi_compute_index_owner_internal.h>

Public Member Functions
void	reinit (const IndexSet &owned_indices, const MPI_Comm &comm)

unsigned int	dof_to_dict_rank (const types::global_dof_index i)

types::global_dof_index	get_index_offset (const unsigned int rank)

unsigned int	get_owning_rank_index (const unsigned int rank_in_owned_indices, const unsigned int guess=0)

Public Attributes
std::vector< unsigned int >	actually_owning_ranks

std::vector< unsigned int >	actually_owning_rank_list

types::global_dof_index	dofs_per_process

std::pair< types::global_dof_index, types::global_dof_index >	local_range

types::global_dof_index	local_size

types::global_dof_index	size

unsigned int	n_dict_procs_in_owned_indices

unsigned int	stride_small_size

Static Public Attributes
static const unsigned int	range_minimum_grain_size = 4096

Private Member Functions
void	partition (const IndexSet &owned_indices, const MPI_Comm &comm)

Detailed Description

Dictionary class with basic partitioning in terms of a single interval of fixed size known to all MPI ranks for two-stage index lookup.

Definition at line 157 of file mpi_compute_index_owner_internal.h.

Member Function Documentation

◆ reinit()

void Utilities::MPI::internal::ComputeIndexOwner::Dictionary::reinit	(	const IndexSet &	owned_indices,
		const MPI_Comm &	comm
	)

inline

Set up the dictionary by computing the partitioning from the global size and sending the rank information on locally owned ranges to the owner of the dictionary part.

Definition at line 225 of file mpi_compute_index_owner_internal.h.

◆ dof_to_dict_rank()

unsigned int Utilities::MPI::internal::ComputeIndexOwner::Dictionary::dof_to_dict_rank ( const types::global_dof_index i )

inline

Translate a global dof index to the MPI rank in the dictionary using dofs_per_process. We multiply by stride_small_size to ensure a balance over the MPI ranks due to the grain size.

Definition at line 446 of file mpi_compute_index_owner_internal.h.

◆ get_index_offset()

types::global_dof_index Utilities::MPI::internal::ComputeIndexOwner::Dictionary::get_index_offset ( const unsigned int rank )

inline

Given an MPI rank id of an arbitrary processor, return the index offset where the local range of that processor begins.

Definition at line 458 of file mpi_compute_index_owner_internal.h.

◆ get_owning_rank_index()

unsigned int Utilities::MPI::internal::ComputeIndexOwner::Dictionary::get_owning_rank_index	(	const unsigned int	rank_in_owned_indices,
		const unsigned int	guess = `0`
	)

inline

Given the rank in the owned indices from actually_owning_ranks, this returns the index of the rank in the actually_owning_rank_list.

Definition at line 473 of file mpi_compute_index_owner_internal.h.

◆ partition()

void Utilities::MPI::internal::ComputeIndexOwner::Dictionary::partition	(	const IndexSet &	owned_indices,
		const MPI_Comm &	comm
	)

inlineprivate

Compute the partition from the global size of the index space and the number of ranks.

Definition at line 497 of file mpi_compute_index_owner_internal.h.

Member Data Documentation

◆ range_minimum_grain_size

const unsigned int Utilities::MPI::internal::ComputeIndexOwner::Dictionary::range_minimum_grain_size = 4096

static

The minimum grain size for the ranges.

Definition at line 162 of file mpi_compute_index_owner_internal.h.

◆ actually_owning_ranks

std::vector<unsigned int> Utilities::MPI::internal::ComputeIndexOwner::Dictionary::actually_owning_ranks

A vector with as many entries as there are dofs in the dictionary of the current process, and each entry containing the rank of the owner of that dof in the IndexSet owned_indices. This is queried in the index lookup, so we keep an expanded list.

Definition at line 170 of file mpi_compute_index_owner_internal.h.

◆ actually_owning_rank_list

std::vector<unsigned int> Utilities::MPI::internal::ComputeIndexOwner::Dictionary::actually_owning_rank_list

A sorted vector containing the MPI ranks appearing in actually_owning_ranks.

Definition at line 176 of file mpi_compute_index_owner_internal.h.

◆ dofs_per_process

types::global_dof_index Utilities::MPI::internal::ComputeIndexOwner::Dictionary::dofs_per_process

The number of unknowns in the dictionary for on each MPI rank used for the index space splitting. For simplicity of index lookup without additional communication, this number is the same on all MPI ranks.

Definition at line 184 of file mpi_compute_index_owner_internal.h.

◆ local_range

std::pair<types::global_dof_index, types::global_dof_index> Utilities::MPI::internal::ComputeIndexOwner::Dictionary::local_range

The local range of the global index space that is represented in the dictionary, computed from dofs_per_process, the current MPI rank, and range_minimum_grain_size.

Definition at line 192 of file mpi_compute_index_owner_internal.h.

◆ local_size

types::global_dof_index Utilities::MPI::internal::ComputeIndexOwner::Dictionary::local_size

The actual size, computed as the minimum of dofs_per_process and the possible end of the index space. Equivalent to local_range.second - local_range.first.

Definition at line 199 of file mpi_compute_index_owner_internal.h.