NAME

       MPI_Comm_delete_attr - Deletes attribute value associated with a key.

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Comm_delete_attr(MPI_Comm comm, int comm_keyval)

Fortran Syntax

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_COMM_DELETE_ATTR(COMM, COMM_KEYVAL, IERROR)
            INTEGER   COMM, COMM_KEYVAL, IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Comm_delete_attr(comm, comm_keyval, ierror)
            TYPE(MPI_Comm), INTENT(IN) :: comm
            INTEGER, INTENT(IN) :: comm_keyval
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       void MPI::Comm::Delete_attr(int comm_keyval)

INPUT/OUTPUT PARAMETER

       comm      Communicator from which the attribute is deleted (handle).

INPUT PARAMETER

       comm_keyval
                 Key value (integer).

OUTPUT PARAMETER

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_Comm_delete_attr  deletes  an attribute from cache by key. This function invokes the attribute delete
       function delete_fn specified when the comm_keyval was created.  The  call  will  fail  if  the  delete_fn
       function returns an error code other than MPI_SUCCESS.

       Whenever  a  communicator  is replicated using the function MPI_Comm_dup, all callback copy functions for
       attributes that are currently set are invoked (in arbitrary order). Whenever a  communicator  is  deleted
       using the function MPI_Comm_free, all callback delete functions for attributes that are currently set are
       invoked.

       This  function  is the same as MPI_Attr_delete but is needed to match the communicator-specific functions
       introduced in the MPI-2 standard. The use of MPI_Attr_delete is deprecated.

NOTES

       Note that it is not defined by the MPI standard what happens if the delete_fn callback invokes other  MPI
       functions.   In  Open  MPI,  it is not valid for delete_fn callbacks (or any of their children) to add or
       delete attributes on the same object on which the delete_fn callback is being invoked.

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.

4.1.6                                             Sep 30, 2023                           MPI_Comm_delete_attr(3)