MPI_Keyval_create(3)

NAME
     MPI_Keyval_create - Generates a new attribute key

SYNOPSIS
     C:

          #include <mpi.h>

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


     C++:

          #include <mpi.h>

          int Comm::Create_keyval(
          Comm::Copy_attr_function*comm_copy_attr_fn,
          Comm::Delete_attr_function*comm_delete_attr_fn,
          void*             extra_state)


     Fortran:

          INCLUDE "mpif.h" (or USE MPI)

          EXTERNAL copy_fn, delete_fn
          INTEGER keyval, extra_state, ierror

          CALL MPI_KEYVAL_CREATE(copy_fn, delete_fn, keyval, extra_state, ierror)


STANDARDS
     This release implements the MPI 1.2 standard, as documented by the MPI
     Forum in the spring 1997 release of MPI:  A Message Passing Interface
     Standard.

DESCRIPTION
     The MPI_Keyval_create routine generates a new attribute key.  This
     routine accepts the following parameters:

     copy_fn        Specifies the copy callback function for keyval

     delete_fn      Specifies the delete callback function for keyval

     extra_state    Specifies an extra state for callback functions
     keyval         Returns the key value for future access (integer)

     ierror         Specifies the return code value for successful completion,
                    which is in MPI_SUCCESS.  MPI_SUCCESS is defined in the
                    mpif.h file.

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

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