17.2.375. MPI_Topo_test

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

17.2.375.1. SYNTAX

17.2.375.1.1. C Syntax

#include <mpi.h>

int MPI_Topo_test(MPI_Comm comm, int *top_type)

17.2.375.1.2. Fortran Syntax

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

17.2.375.1.3. 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()

17.2.375.2. INPUT PARAMETER

  • comm: Communicator (handle).

17.2.375.3. OUTPUT PARAMETERS

  • top_type: Topology type of communicator comm (choice).

  • IERROR: Fortran only: Error status (integer).

17.2.375.4. 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

17.2.375.5. ERRORS

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.

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.