NAME

       MPI_Keyval_free  -  Frees  attribute  key  for  communicator  cache  attribute  -- use of this routine is
       deprecated.

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Keyval_free(int *keyval)

Fortran Syntax

       INCLUDE 'mpif.h'
       MPI_KEYVAL_FREE(KEYVAL, IERROR)
            INTEGER   KEYVAL, IERROR

INPUT PARAMETER

       keyval    Frees the integer key value (integer).

OUTPUT PARAMETER

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       Note that use of this routine is deprecated as of MPI-2. Please use MPI_Comm_free_keyval instead.

       This deprecated routine is not available in C++.

       Frees an extant attribute key. This function sets the value of keyval to  MPI_KEYVAL_INVALID.  Note  that
       it  is  not erroneous to free an attribute key that is in use, because the actual free does not transpire
       until after all references (in other communicators on the process) to the  key  have  been  freed.  These
       references  need to be explicitly freed by the program, either via calls to MPI_Attr_delete that free one
       attribute instance, or by calls to MPI_Comm_free that free all attribute instances  associated  with  the
       freed communicator.

NOTE

       Key values are global (they can be used with any and all communicators).

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.

SEE ALSO

       MPI_Keyval_create
       MPI_Comm_free_keyval

4.1.6                                             Sep 30, 2023                                MPI_Keyval_free(3)