NAME

       MPI_Comm_get_parent -  Return the parent communicator for this process

SYNOPSIS

       int MPI_Comm_get_parent(MPI_Comm *parent)

OUTPUT PARAMETERS

       parent - the parent communicator (handle)

NOTES

       If a process was started with MPI_Comm_spawn or MPI_Comm_spawn_multiple , MPI_Comm_get_parent returns the
       parent intercommunicator of the current process. This  parent  intercommunicator  is  created  implicitly
       inside of MPI_Init and is the same intercommunicator returned by MPI_Comm_spawn in the parents.

       If the process was not spawned, MPI_Comm_get_parent returns MPI_COMM_NULL .

       After the parent communicator is freed or disconnected, MPI_Comm_get_parent returns MPI_COMM_NULL .

THREAD AND INTERRUPT SAFETY

       This  routine  is  both  thread-  and interrupt-safe.  This means that this routine may safely be used by
       multiple threads and from within a signal handler.

NOTES FOR FORTRAN

       All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have an additional argument ierr at the
       end of the argument list.  ierr is an integer and has the same meaning as the return value of the routine
       in C.  In Fortran, MPI routines are subroutines, and are invoked with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error value; C routines as the value of  the
       function  and Fortran routines in the last argument.  Before the value is returned, the current MPI error
       handler is called.  By default, this error handler aborts the MPI job.  The error handler may be  changed
       with    MPI_Comm_set_errhandler   (for   communicators),   MPI_File_set_errhandler   (for   files),   and
       MPI_Win_set_errhandler (for RMA windows).  The MPI-1 routine MPI_Errhandler_set may be used but  its  use
       is  deprecated.   The  predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be
       returned.  Note that MPI does not guarentee that an MPI program can continue past an error; however,  MPI
       implementations will attempt to continue whenever possible.

       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_ARG
              -  Invalid  argument.   Some  argument  is invalid and is not identified by a specific error class
              (e.g., MPI_ERR_RANK ).

                                                   11/12/2016                             MPI_Comm_get_parent(3)