Register functions for user-defined data representations


int MPI_Register_datarep(ROMIO_CONST char *datarep,
                       MPI_Datarep_conversion_function *read_conversion_fn,
                       MPI_Datarep_conversion_function *write_conversion_fn,
                       MPI_Datarep_extent_function *dtype_file_extent_fn,
                       void *extra_state)

Input Parameters

data representation name (string)
function invoked to convert from file representation to native representation (function)
function invoked to convert from native representation to file representation (function)
function invoked to get the exted of a datatype as represented in the file (function)
pointer to extra state that is passed to each of the three functions


This function allows the user to provide routines to convert data from an external representation, used within a file, and the native representation, used within the CPU. There is one predefined data representation, external32. Please consult the MPI-2 standard for details on this function.

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.