plucky (3) MPI_Group_incl.openmpi.3.gz

SYNTAX

   C Syntax
          #include <mpi.h>

          int MPI_Group_incl(MPI_Group group, int n, const int ranks[],
              MPI_Group *newgroup)

   Fortran Syntax
          USE MPI
          ! or the older form: INCLUDE 'mpif.h'

          MPI_GROUP_INCL(GROUP, N, RANKS, NEWGROUP, IERROR)
              INTEGER GROUP, N, RANKS(*), NEWGROUP, IERROR

   Fortran 2008 Syntax
          USE mpi_f08

          MPI_Group_incl(group, n, ranks, newgroup, ierror)
              TYPE(MPI_Group), INTENT(IN) :: group
              INTEGER, INTENT(IN) :: n, ranks(n)
              TYPE(MPI_Group), INTENT(OUT) :: newgroup
              INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

       • group : Group (handle).

       •

         n (Number of elements in array ranks (and size of)
                newgroup)(integer).

       •

         ranks (Ranks of processes in group to appear in newgroup (array of)
                integers).

OUTPUT PARAMETERS

       •

         newgroup (New group derived from above, in the order defined by)
                ranks (handle).

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

DESCRIPTION

       The  function  MPI_Group_incl  creates  a  group group_out that consists of the n processes in group with
       ranks rank[0], …, rank[n-1]; the process with rank i in group_out is the process with  rank  ranks[i]  in
       group.   Each of the n elements of ranks must be a valid rank in group and all elements must be distinct,
       or else the program is erroneous. If n = 0, then group_out is MPI_GROUP_EMPTY.  This  function  can,  for
       instance, be used to reorder the elements of a group.

NOTE

       This implementation does not currently check to ensure that there are no duplicates in the list of ranks.

ERRORS

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

       Before the error value is returned, the current MPI  error  handler  associated  with  the  communication
       object  (e.g.,  communicator, window, file) is called.  If no communication object is associated with the
       MPI call, then the call is considered attached to MPI_COMM_SELF and will call the  associated  MPI  error
       handler.   When   MPI_COMM_SELF   is   not  initialized  (i.e.,  before  MPI_Init/MPI_Init_thread,  after
       MPI_Finalize, or when using the Sessions Model exclusively) the error raises the initial  error  handler.
       The  initial  error handler can be changed by calling MPI_Comm_set_errhandler on MPI_COMM_SELF when using
       the World model, or the mpi_initial_errhandler CLI argument to mpiexec or info  key  to  MPI_Comm_spawn/‐
       MPI_Comm_spawn_multiple.   If no other appropriate error handler has been set, then the MPI_ERRORS_RETURN
       error handler is called for MPI I/O functions and the MPI_ERRORS_ABORT error handler is  called  for  all
       other MPI functions.

       Open MPI includes three predefined error handlers that can be used:

       • MPI_ERRORS_ARE_FATAL Causes the program to abort all connected MPI processes.

       • MPI_ERRORS_ABORT An error handler that can be invoked on a communicator, window, file, or session. When
         called on a communicator, it acts as if MPI_Abort was called on  that  communicator.  If  called  on  a
         window  or file, acts as if MPI_Abort was called on a communicator containing the group of processes in
         the corresponding window or file. If called on a session, aborts only the local process.

       • MPI_ERRORS_RETURN Returns an error code to the application.

       MPI applications can also implement their own error handlers by calling:

       • MPI_Comm_create_errhandler then MPI_Comm_set_errhandler

       • MPI_File_create_errhandler then MPI_File_set_errhandler

       • MPI_Session_create_errhandler then MPI_Session_set_errhandler or at MPI_Session_init

       • MPI_Win_create_errhandler then MPI_Win_set_errhandler

       Note that MPI does not guarantee that an MPI program can continue past an error.

       See the MPI man page for a full list of MPI error codes.

       See the Error Handling section of the MPI-3.1 standard for more information.

       SEE ALSO:
          MPI_Group_compare

COPYRIGHT

       2003-2025, The Open MPI Community

                                                  Feb 17, 2025                                 MPI_GROUP_INCL(3)