A group is a representation of a subset of the processes within a communicator. More...

#include <group.hpp>

Collaboration diagram for boost::mpi::group:

Classes
struct	group_free
	INTERNAL ONLY. More...

Public Member Functions
	group ()
	Constructs an empty group. More...

	group (const MPI_Group &in_group, bool adopt)
	Constructs a group from an `MPI_Group`. More...

optional< int >	rank () const
	Determine the rank of the calling process in the group. More...

int	size () const
	Determine the number of processes in the group. More...

template<typename InputIterator , typename OutputIterator >
OutputIterator	translate_ranks (InputIterator first, InputIterator last, const group &to_group, OutputIterator out)
	Translates the ranks from one group into the ranks of the same processes in another group. More...

	operator bool () const
	Determines whether the group is non-empty. More...

	operator MPI_Group () const
	Retrieves the underlying `MPI_Group` associated with this group. More...

template<typename InputIterator >
group	include (InputIterator first, InputIterator last)
	Creates a new group including a subset of the processes in the current group. More...

template<typename InputIterator >
group	exclude (InputIterator first, InputIterator last)
	Creates a new group from all of the processes in the current group, exluding a specific subset of the processes. More...

template<>
BOOST_MPI_DECL int *	translate_ranks (int first, int last, const group &to_group, int *out)
	INTERNAL ONLY. More...

template<>
BOOST_MPI_DECL group	include (int first, int last)
	INTERNAL ONLY. More...

template<>
BOOST_MPI_DECL group	exclude (int first, int last)
	INTERNAL ONLY. More...

Protected Attributes
shared_ptr< MPI_Group >	group_ptr
	The underlying MPI group. More...

Detailed Description

A group is a representation of a subset of the processes within a communicator.

The group class allows one to create arbitrary subsets of the processes within a communicator. One can compute the union, intersection, or difference of two groups, or create new groups by specifically including or excluding certain processes. Given a group, one can create a new communicator containing only the processes in that group.

Constructor & Destructor Documentation

boost::mpi::group::group ( )

inline

Constructs an empty group.

Referenced by exclude(), and include().

boost::mpi::group::group	(	const MPI_Group &	in_group,
		bool	adopt
	)

Constructs a group from an MPI_Group.

This routine allows one to construct a Boost.MPI group from a C MPI_Group. The group object can (optionally) adopt the MPI_Group, after which point the group object becomes responsible for freeing the MPI_Group when the last copy of group disappears.

Parameters

in_group	The `MPI_Group` used to construct this `group`.
adopt	Whether the `group` should adopt the `MPI_Group`. When true, the `group` object (or one of its copies) will free the group (via `MPI_Comm_free`) when the last copy is destroyed. Otherwise, the user is responsible for calling `MPI_Group_free`.

Member Function Documentation

template<typename InputIterator >

group boost::mpi::group::exclude	(	InputIterator	first,
		InputIterator	last
	)

Creates a new group from all of the processes in the current group, exluding a specific subset of the processes.

This routine creates a new group which includes all of the processes in the current group except those whose ranks are listed in the integer iterator range [first, last). Equivalent to MPI_Group_excl.

first The beginning of the iterator range of ranks to exclude.

last Past the end of the iterator range of ranks to exclude.

Returns: A new group containing all of the processes in the current group except those processes with ranks [first, last) in the current group.

References BOOST_MPI_CHECK_RESULT, and group().

template<>

BOOST_MPI_DECL group boost::mpi::group::exclude	(	int *	first,
		int *	last
	)

INTERNAL ONLY.

Specialization of group::exclude that handles the one case where we can avoid any memory allocation or copying before creating the group.

template<typename InputIterator >

group boost::mpi::group::include	(	InputIterator	first,
		InputIterator	last
	)

Creates a new group including a subset of the processes in the current group.

This routine creates a new group which includes only those processes in the current group that are listed in the integer iterator range [first, last). Equivalent to MPI_Group_incl.

first The beginning of the iterator range of ranks to include.

last Past the end of the iterator range of ranks to include.

Returns: A new group containing those processes with ranks [first, last) in the current group.

References BOOST_MPI_CHECK_RESULT, and group().

template<>

BOOST_MPI_DECL group boost::mpi::group::include	(	int *	first,
		int *	last
	)

INTERNAL ONLY.

Specialization of group::include that handles the one case where we can avoid any memory allocation or copying before creating the group.

boost::mpi::group::operator bool ( ) const

inline

Determines whether the group is non-empty.

Returns: True if the group is not empty, false if it is empty.

boost::mpi::group::operator MPI_Group ( ) const

inline

Retrieves the underlying MPI_Group associated with this group.

Returns: The MPI_Group handle manipulated by this object. If this object represents the empty group, returns MPI_GROUP_EMPTY.

optional<int> boost::mpi::group::rank ( ) const

Determine the rank of the calling process in the group.

This routine is equivalent to MPI_Group_rank.

Returns: The rank of the calling process in the group, which will be a value in [0, size()). If the calling process is not in the group, returns an empty value.

int boost::mpi::group::size ( ) const

Determine the number of processes in the group.

This routine is equivalent to MPI_Group_size.

Returns: The number of processes in the group.

template<typename InputIterator , typename OutputIterator >

OutputIterator boost::mpi::group::translate_ranks	(	InputIterator	first,
		InputIterator	last,
		const group &	to_group,
		OutputIterator	out
	)

Translates the ranks from one group into the ranks of the same processes in another group.

This routine translates each of the integer rank values in the iterator range [first, last) from the current group into rank values of the corresponding processes in to_group. The corresponding rank values are written via the output iterator out. When there is no correspondence between a rank in the current group and a rank in to_group, the value MPI_UNDEFINED is written to the output iterator.

Parameters

first	Beginning of the iterator range of ranks in the current group.
last	Past the end of the iterator range of ranks in the current group.
to_group	The group that we are translating ranks to.
out	The output iterator to which the translated ranks will be written.

Returns: the output iterator, which points one step past the last rank written.

References BOOST_MPI_CHECK_RESULT, boost::multiprecision::backends::i, boost::n, and boost::out.

template<>

BOOST_MPI_DECL int* boost::mpi::group::translate_ranks	(	int *	first,
		int *	last,
		const group &	to_group,
		int *	out
	)

INTERNAL ONLY.

Specialization of translate_ranks that handles the one case where we can avoid any memory allocation or copying.

Member Data Documentation

shared_ptr<MPI_Group> boost::mpi::group::group_ptr

protected

The underlying MPI group.

This is a shared pointer, so the actual MPI group which will be shared among all related instances of the group class. When there are no more such instances, the group will be automatically freed.

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

boost_1_57_0/boost/mpi/group.hpp

Classes

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation