NAME

       MPI_Type_create_keyval -  Create an attribute keyval for MPI datatypes

SYNOPSIS

       int MPI_Type_create_keyval(MPI_Type_copy_attr_function *type_copy_attr_fn,
                                MPI_Type_delete_attr_function *type_delete_attr_fn,
                                int *type_keyval, void *extra_state)

INPUT PARAMETERS

       type_copy_attr_fn
              - copy callback function for type_keyval (function)
       type_delete_attr_fn
              - delete callback function for type_keyval (function)
       extra_state
              - extra state for callback functions

OUTPUT PARAMETERS

       type_keyval
              - key value for future access (integer)

NOTES

       Default copy and delete functions are available.  These are
       MPI_TYPE_NULL_COPY_FN
              - empty copy function
       MPI_TYPE_NULL_DELETE_FN
              - empty delete function
       MPI_TYPE_DUP_FN
              - simple dup function

RETURN VALUE FROM ATTRIBUTE CALLBACKS

       The  MPI-2 versions of the attribute callbacks should return either MPI_SUCCESS on success or a valid MPI
       error code or class on failure.  The MPI standard is ambiguous on this point, but as MPI-2  provides  the
       routines MPI_Add_error_class and MPI_Add_error_code that allow the user to define and use MPI error codes
       and classes.

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_OTHER
              - Other error; use MPI_Error_string to get more information about this error code.

                                                   11/12/2016                          MPI_Type_create_keyval(3)