int MPI_Attr_delete(MPI_Comm comm, int keyval)
int MPI_Attr_get(MPI_Comm comm, int keyval, void *attribute_val, int *flag)
int MPI_Attr_put(MPI_Comm comm, int keyval, void* attribute_val)
int MPI_DUP_FN(MPI_Comm oldcomm, int keyval, void *extra_state, void *attribute_val_in, void *attribute_val_out, int *flag)
int MPI_Keyval_create(MPI_Copy_function *copy_fn, MPI_Delete_function *delete_fn, int *keyval, void* extra_state)
int MPI_Keyval_free(int *keyval)
int MPI_NULL_COPY_FN(MPI_Comm oldcomm, int keyval, void *extra_state, void *attribute_val_in, void *attribute_val_out, int *flag)
int MPI_NULL_DELETE_FN(MPI_Comm comm, int keyval, void *attribute_val, void *extra_state)