oracular (3) MPI_Comm_compare.openmpi.3.gz

NAME

       MPI_Comm_compare  -  Compares two communicators.

SYNTAX

C Syntax

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

Fortran Syntax

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_COMM_COMPARE(COMM1, COMM2, RESULT, IERROR)
            INTEGER   COMM1, COMM2, RESULT, IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Comm_compare(comm1, comm2, result, ierror)
            TYPE(MPI_Comm), INTENT(IN) :: comm1, comm2
            INTEGER, INTENT(OUT) :: result
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       static int Comm::Compare(const Comm& comm1, const Comm& comm2)

INPUT PARAMETERS

       comm1     Comm1 (handle).

       comm2     Comm2 (handle).

OUTPUT PARAMETERS

       result    Result of comparison (integer).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_IDENT  results  if  and only if comm1 and comm2 are handles for the same object (identical groups and
       same contexts). MPI_CONGRUENT results if the underlying groups are identical  in  constituents  and  rank
       order;  these  communicators  differ  only  by  context. MPI_SIMILAR results of the group members of both
       communicators are the same but the rank order differs. MPI_UNEQUAL results otherwise.

ERRORS

       Almost all MPI routines return an error value; C routines as  the  value  of  the  function  and  Fortran
       routines in the last argument. C++ functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the  C++  exception  mechanism  will  be  used  to  throw  an
       MPI::Exception object.

       Before  the  error  value  is  returned,  the current MPI error handler is called. By default, this error
       handler aborts the MPI job, except for I/O function  errors.  The  error  handler  may  be  changed  with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values
       to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.