NAME

       MPI_Comm_disconnect - Deallocates communicator object and sets handle to MPI_COMM_NULL.

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Comm_disconnect(MPI_Comm *comm)

Fortran Syntax

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

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Comm_disconnect(comm, ierror)
            TYPE(MPI_Comm), INTENT(INOUT) :: comm
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       void MPI::Comm::Disconnect()

INPUT/OUTPUT PARAMETER

       comm      Communicator (handle).

OUTPUT PARAMETER

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_Comm_disconnect  waits  for all pending communication on comm to complete internally, deallocates the
       communicator object, and sets the handle to MPI_COMM_NULL. It is a collective operation.

       It may not be called with the communicator MPI_COMM_WORLD or MPI_COMM_SELF.

       MPI_Comm_disconnect may be called only if all communication is complete and  matched,  so  that  buffered
       data can be delivered to its destination. This requirement is the same as for MPI_Finalize.

       MPI_Comm_disconnect  has the same action as MPI_Comm_free, except that it waits for pending communication
       to finish internally and enables the guarantee about the behavior of disconnected processes.

NOTES

       To disconnect two processes you may need to call MPI_Comm_disconnect, MPI_Win_free, and MPI_File_close to
       remove all communication paths between the two processes. Note that it may  be  necessary  to  disconnect
       several  communicators  (or  to  free  several  windows  or  files)  before  two processes are completely
       independent.

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_Comm_connect
       MPI_Comm_accept

4.1.6                                             Sep 30, 2023                            MPI_Comm_disconnect(3)