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MPI_Comm_split_type - Creates new communicators based on colors
and keys.
#include <mpi.h>
int MPI_Comm_split_type(MPI_Comm comm, int split_type, int key,
MPI_Info info, MPI_Comm *newcomm)
INCLUDE ’mpif.h’
MPI_COMM_SPLIT_TYPE(COMM, SPLIT_TYPE, KEY, INFO, NEWCOMM, IERROR)
INTEGER COMM, SPLIT_TYPE, KEY, INFO, NEWCOMM, IERROR
- comm
- Communicator (handle).
- split_type
- Type of processes
to be grouped together (integer).
- key
- Control of rank assignment (integer).
- info
- Info argument (handle).
- newcomm
- New communicator
(handle).
- IERROR
- Fortran only: Error status (integer).
This function
partitions the group associated with comm into disjoint subgroups, based
on the type specied by split_type. Each subgroup contains all processes
of the same type. Within each subgroup, the processes are ranked in the
order defined by the value of the argument key, with ties broken according
to their rank in the old group. A new communicator is created for each subgroup
and returned in newcomm. This is a collective call; all processes must provide
the same split_type, but each process is permitted to provide different
values for key. An exception to this rule is that a process may supply the
type value MPI_UNDEFINED, in which case newcomm returns MPI_COMM_NULL.
- MPI_COMM_TYPE_SHARED
- This type splits the communicator into
subcommunicators, each of which can create a shared memory region.
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.
MPI_Comm_create
MPI_Intercomm_create
MPI_Comm_dup
MPI_Comm_free
MPI_Comm_split
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