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