MPI_Dist_graph_create - MPI_DIST_GRAPH_CREATE returns a handle to a new communicator to which the distributed graph topology information is attached.

SYNOPSIS

int MPI_Dist_graph_create(MPI_Comm comm_old, int n, int sources[],
int degrees[], int destinations[], int weights[],
MPI_Info info, int reorder, MPI_Comm *comm_dist_graph)

INPUT PARAMETERS

comm_old

- input communicator (handle)

n

- number of source nodes for which this process specifies edges (non-negative integer)

sources

- array containing the n source nodes for which this process specifies edges (array of non-negative integers)

degrees

- array specifying the number of destinations for each source node in the source node array (array of non-negative integers)

destinations

- destination nodes for the source nodes in the source node array (array of non-negative integers)

weights

- weights for source to destination edges (array of non-negative integers)

info

- hints on optimization and interpretation of weights (handle)

reorder

- the process may be reordered (true) or not (false) (logical)

OUTPUT PARAMETER

comm_dist_graph

- communicator with distributed graph topology added (handle)

THREAD AND INTERRUPT SAFETY

This routine is thread-safe. This means that this routine may be
safely used by multiple threads without the need for any user-provided
thread locks. However, the routine is not interrupt safe. Typically,
this is due to the use of memory allocation routines such as
malloc
or other non-MPICH runtime routines that are themselves not interrupt-safe.

NOTES FOR FORTRAN

All MPI routines in Fortran (except for
MPI_WTIME
and
MPI_WTICK
) have
an additional argument
ierr
at the end of the argument list.
ierr
is an integer and has the same meaning as the return value of the routine
in C. In Fortran, MPI routines are subroutines, and are invoked with the
call
statement.

All MPI objects (e.g.,
MPI_Datatype
,
MPI_Comm
) are of type
INTEGER
in Fortran.

ERRORS

All MPI routines (except
MPI_Wtime
and
MPI_Wtick
) return an error value;
C routines as the value of the function and Fortran routines in the last
argument. Before the value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job. The error handler
may be changed with
MPI_Comm_set_errhandler
(for communicators),
MPI_File_set_errhandler
(for files), and
MPI_Win_set_errhandler
(for
RMA windows). The MPI-1 routine
MPI_Errhandler_set
may be used but
its use is deprecated. The predefined error handler
MPI_ERRORS_RETURN
may be used to cause error values to be returned.
Note that MPI does
not
guarentee that an MPI program can continue past
an error; however, MPI implementations will attempt to continue whenever
possible.