NAME

       MPI_Keyval_create -  Greates a new attribute key

SYNOPSIS

       int MPI_Keyval_create(MPI_Copy_function *copy_fn,
                            MPI_Delete_function *delete_fn,
                            int *keyval, void *extra_state)

INPUT PARAMETERS

       copy_fn
              - Copy callback function for keyval

       delete_fn
              - Delete callback function for keyval

       extra_state
              - Extra state for callback functions

OUTPUT PARAMETERS

       keyval - key value for future access (integer)

NOTES

       Key values are global (available for any and all communicators).

       There  are  subtle  differences  between  C  and  Fortran that require that the copy_fn be
       written in the same language that MPI_Keyval_create is called from.  This should not be  a
       problem for most users; only programmers using both Fortran and C in the same program need
       to be sure that they follow this rule.

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.

DEPRECATED FUNCTION

       The MPI-2 standard deprecated a number of routines because MPI-2 provides better versions.
       This routine is one of those that was deprecated.  The routine may continue  to  be  used,
       but  new  code  should  use  the replacement routine.  The replacement for this routine is
       MPI_Comm_create_keyval .

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_INTERN
              -  This  error  is returned when some part of the MPICH implementation is unable to
              acquire memory.
       MPI_ERR_ARG
              - Invalid argument.  Some argument is invalid and is not identified by  a  specific
              error class (e.g., MPI_ERR_RANK ).

SEE ALSO

       MPI_Keyval_free, MPI_Comm_create_keyval

                                            11/12/2016                       MPI_Keyval_create(3)