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MPI_Keyval_create(3) MPI MPI_Keyval_create(3)
MPI_Keyval_create - Greates a new attribute key
int MPI_Keyval_create(MPI_Copy_function *copy_fn,
int *keyval, void *extra_state)
- Copy callback function for keyval
- Delete callback function for keyval
- Extra state for callback functions
keyval - key value for future access (integer)
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
programers 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-
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
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
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.
- No error; MPI routine completed successfully.
- This error is returned when some part of the MPICH
implementation is unable to acquire memory.
- Invalid argument. Some argument is invalid and is not
identified by a specific error class (e.g., MPI_ERR_RANK ).