NAME¶
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)
- 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 or MPI_UNWEIGHTED)
- 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.
- MPI_SUCCESS
- - No error; MPI routine completed successfully.
- MPI_ERR_ARG
- - Invalid argument. Some argument is invalid and is not
identified by a specific error class (e.g., MPI_ERR_RANK ).
- MPI_ERR_OTHER
- - Other error; use MPI_Error_string to get more
information about this error code.
LOCATION¶
dist_gr_create.c