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