Dune::Torus< CollectiveCommunication, d > Class Template Reference

#include <dune/grid/yaspgrid/torus.hh>

Classes
class	ProcListIterator

Public Types
typedef std::array< int, d >	iTupel
	type used to pass tupels in and out

Public Member Functions
	Torus ()
	constructor making uninitialized object
	Torus (CollectiveCommunication comm, int tag, iTupel size, const YLoadBalance< d > *lb)
	make partitioner from communicator and coarse mesh size
int	rank () const
	return own rank
iTupel	coord () const
	return own coordinates
int	procs () const
	return number of processes
const iTupel &	dims () const
	return dimensions of torus
int	dims (int i) const
	return dimensions of torus in direction i
CollectiveCommunication	comm () const
	return communicator
int	tag () const
	return tag used by torus
bool	inside (iTupel c) const
	return true if coordinate is inside torus
iTupel	rank_to_coord (int rank) const
	map rank to coordinate in torus using lexicographic ordering
int	coord_to_rank (iTupel coord) const
	map coordinate in torus to rank using lexicographic ordering
int	rank_relative (int rank, int dir, int cnt) const
	return rank of process where its coordinate in direction dir has offset cnt (handles periodic case)
int	color (const iTupel &coord) const
	assign color to given coordinate
int	color (int rank) const
	assign color to given rank
int	neighbors () const
	return the number of neighbors, which is \(3^d-1\)
bool	is_neighbor (iTupel delta, std::bitset< d > periodic) const
	return true if neighbor with given delta is a neighbor under the given periodicity
double	partition (int rank, iTupel origin_in, iTupel size_in, iTupel &origin_out, iTupel &size_out) const
	partition the given grid onto the torus and return the piece of the process with given rank; returns load imbalance More...
ProcListIterator	sendbegin () const
	first process in send list
ProcListIterator	sendend () const
	end of send list
ProcListIterator	recvbegin () const
	first process in receive list
ProcListIterator	recvend () const
	last process in receive list
void	send (int rank, void *buffer, int size) const
	store a send request; buffers are sent in order; handles also local requests with memcpy
void	recv (int rank, void *buffer, int size) const
	store a receive request; buffers are received in order; handles also local requests with memcpy
void	exchange () const
	exchange messages stored in request buffers; clear request buffers afterwards
double	global_max (double x) const
	global max
void	print (std::ostream &s) const
	print contents of torus object

Detailed Description

template<class CollectiveCommunication, int d>
class Dune::Torus< CollectiveCommunication, d >

Torus provides all the functionality to handle a toroidal communication structure:

• Map a set of processes (given by an MPI communicator) to a torus of dimension d. The "optimal" torus dimensions are determined by a coarse mesh. The maximum side length is minimized.
• Provide lists of neighboring processes and a method for nearest neighbor exchange using asynchronous communication with MPI. The periodic case is handled where one process might have to exchange several messages with the same process. (Logically, a process has always \(3^d-1\) neighbors, but several of these logical neighbors might be identical)
• Provide means to partition a grid to the torus.

Member Function Documentation

partition()

template<class CollectiveCommunication , int d>

double Dune::Torus< CollectiveCommunication, d >::partition ( int  rank, iTupel  origin_in, iTupel  size_in, iTupel &  origin_out, iTupel &  size_out  ) const

inline

partition the given grid onto the torus and return the piece of the process with given rank; returns load imbalance

Parameters

rank	rank of our processor
origin_in	global origin
size_in	global size
origin_out	origin of this processors interior
size_out	size of this processors interior

References Dune::Torus< CollectiveCommunication, d >::coord(), Dune::Torus< CollectiveCommunication, d >::rank(), Dune::Torus< CollectiveCommunication, d >::rank_to_coord(), and Dune::CollectiveCommunication< Communicator >::size().

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The documentation for this class was generated from the following file:

• dune/grid/yaspgrid/torus.hh