MPI_COMM_COMPARE, MPI_Comm_compare

Purpose

Compares the groups and context of two communicators.

C synopsis

#include <mpi.h>
int MPI_Comm_compare(MPI_Comm comm1,MPI_Comm comm2,int *result);

C++ synopsis

#include mpi.h
int MPI::Comm::Compare(const MPI::Comm& comm1, const MPI::Comm& comm2);

FORTRAN synopsis

include 'mpif.h' or use mpi
MPI_COMM_COMPARE(INTEGER COMM1,INTEGER COMM2,INTEGER RESULT,INTEGER IERROR)

Parameters

comm1
     is the first communicator (handle) (IN)

comm2
     is the second communicator (handle) (IN)

result
     is an integer specifying the result. The defined values are:
     MPI_IDENT, MPI_CONGRUENT, MPI_SIMILAR, and MPI_UNEQUAL. (OUT)

IERROR
     is the FORTRAN return code. It is always the last argument.

Description

This subroutine compares the groups and contexts of two communicators. The
following is an explanation of each MPI_COMM_COMPARE defined value:

MPI_IDENT
     comm1 and comm2 are handles for the identical object

MPI_CONGRUENT
     the underlying groups are identical in constituents and rank order
     (both local and remote groups for intercommunications), but are
     different in context

MPI_SIMILAR
     the group members of both communicators are the same, but are
     different in rank order (both local and remote groups for
     intercommunication),

MPI_UNEQUAL
     if none of the above.

Errors

Invalid communicator(s)

MPI not initialized

MPI already finalized

Related information

     MPI_GROUP_COMPARE