MPI_Topo_test(3)

NAME
MPI_Topo_test - Determines the type of topology (if any) associated with a communicator.

SYNTAX

C Syntax
#include <mpi.h>
int MPI_Topo_test(MPI_Comm comm, int *top_type)

Fortran Syntax
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_TOPO_TEST(COMM, TOP_TYPE, IERROR)
	INTEGER	COMM, TOP_TYPE, IERROR

Fortran 2008 Syntax
USE mpi_f08
MPI_Topo_test(comm, status, ierror)
	TYPE(MPI_Comm), INTENT(IN) :: comm
	INTEGER, INTENT(OUT) :: status
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror
		DOUBLE PRECISION MPI_Wtick()
		DOUBLE PRECISION MPI_Wtime()

INPUT PARAMETER

comm
    Communicator (handle).

OUTPUT PARAMETERS

top_type
    Topology type of communicator comm (choice).

IERROR
    Fortran only: Error status (integer).

DESCRIPTION
The function MPI_Topo_test returns the type of topology that is assigned to a communicator.

The output value top_type is one of the following:

    MPI_GRAPH		graph topology
    MPI_CART		Cartesian topology
    MPI_DIST_GRAPH	distributed graph topology
    MPI_UNDEFINED	no topology

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.

SEE ALSO
MPI_Graph_create
MPI_Cart_create