MPI_Win_create_keyval(3)

NAME
MPI_Win_create_keyval - Creates a keyval for a window.

SYNTAX

C Syntax
#include <mpi.h>
int MPI_Win_create_keyval(MPI_Win_copy_attr_function *win_copy_attr_fn,
	MPI_Win_delete_attr_function *win_delete_attr_fn,
	int *win_keyval, void *extra_state)

Fortran Syntax (see FORTRAN 77 NOTES)
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_WIN_CREATE_KEYVAL(WIN_COPY_ATTR_FN, WIN_DELETE_ATTR_FN,
	WIN_KEYVAL, EXTRA_STATE, IERROR)
	EXTERNAL WIN_COPY_ATTR_FN, WIN_DELETE_ATTR_FN
	INTEGER WIN_KEYVAL, IERROR
	INTEGER(KIND=MPI_ADDRESS_KIND) EXTRA_STATE

Fortran 2008 Syntax
USE mpi_f08
MPI_Win_create_keyval(win_copy_attr_fn, win_delete_attr_fn, win_keyval,
		extra_state, ierror)
	PROCEDURE(MPI_Win_copy_attr_function) :: win_copy_attr_fn
	PROCEDURE(MPI_Win_delete_attr_function) :: win_delete_attr_fn
	INTEGER, INTENT(OUT) :: win_keyval
	INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(IN) :: extra_state
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

win_copy_attr_fn
    Copy callback function for win_keyval (function).

win_delete_attr_fn
    Delete callback function for win_keyval (function).

extra_state
    Extra state for callback functions.

OUTPUT PARAMETERS

win_keyval
    Key value for future access (integer).

IERROR
    Fortran only: Error status (integer).

DESCRIPTION
The argument win_copy_attr_fn may be specified as MPI_WIN_NULL_COPY_FN or MPI_WIN_DUP_FN from either C, C++, or Fortran. MPI_WIN_NULL_COPY_FN is a function that serves only to return flag = 0 and MPI_SUCCESS. MPI_WIN_DUP_FN is a simple-minded copy function that sets flag = 1, returns the value of attribute_val_in in attribute_val_out, and returns MPI_SUCCESS.

The argument win_delete_attr_fn may be specified as MPI_WIN_NULL_DELETE_FN from either C, C++, or Fortran. MPI_WIN_NULL_DELETE_FN is a function that serves only to return MPI_SUCCESS.

The C callback functions are:

typedef int MPI_Win_copy_attr_function(MPI_Win oldwin, int win_keyval,
             void *extra_state, void *attribute_val_in,
             void *attribute_val_out, int *flag);

and

typedef int MPI_Win_delete_attr_function(MPI_Win win, int win_keyval,
             void *attribute_val, void *extra_state);

The Fortran callback functions are:

SUBROUTINE WIN_COPY_ATTR_FN(OLDWIN, WIN_KEYVAL, EXTRA_STATE,
	ATTRIBUTE_VAL_IN, ATTRIBUTE_VAL_OUT, FLAG, IERROR)
	INTEGER OLDWIN, WIN_KEYVAL, IERROR
	INTEGER(KIND=MPI_ADDRESS_KIND) EXTRA_STATE, ATTRIBUTE_VAL_IN,
		ATTRIBUTE_VAL_OUT
	LOGICAL FLAG

and

SUBROUTINE WIN_DELETE_ATTR_FN(WIN, WIN_KEYVAL, ATTRIBUTE_VAL,
	EXTRA_STATE, IERROR)
	INTEGER WIN, WIN_KEYVAL, IERROR
	INTEGER(KIND=MPI_ADDRESS_KIND) ATTRIBUTE_VAL, EXTRA_STATE

The C++ callbacks are:

typedef int MPI::Win::Copy_attr_function(const MPI::Win& oldwin,
	int win_keyval, void* extra_state, void* attribute_val_in,
	void* attribute_val_out, bool& flag);

and

typedef int MPI::Win::Delete_attr_function(MPI::Win& win, int win_keyval, void* attribute_val, void* extra_state);

FORTRAN 77 NOTES
The MPI standard prescribes portable Fortran syntax for the EXTRA_STATE argument only for Fortran 90. FORTRAN 77 users may use the non-portable syntax

     INTEGER*MPI_ADDRESS_KIND EXTRA_STATE

where MPI_ADDRESS_KIND is a constant defined in mpif.h and gives the length of the declared integer in bytes.

ERRORS
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.

Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.