MPI_Topo_test(3) man page (version 3.1.6)

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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

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Table of Contents

• Name
• Syntax
• C Syntax
• Fortran Syntax
• Fortran 2008 Syntax
• Input Parameter
• Output Parameters
• Description
• Errors
• See Also

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Page last modified: 20-Mar-2020
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