NAME

       MPI_Comm_get_errhandler -  Get the error handler attached to a communicator

SYNOPSIS

       int MPI_Comm_get_errhandler(MPI_Comm comm, MPI_Errhandler *errhandler)

INPUT PARAMETERS

       comm   - communicator (handle)

OUTPUT PARAMETERS

       errhandler
              - error handler currently associated with communicator (handle)

NOTE ON IMPLEMENTATION

       The  MPI  Standard  was  unclear  on  whether  this  routine  required  the  user  to call
       MPI_Errhandler_free once for each call made to this routine in order  to  free  the  error
       handler.   After  some  debate,  the  MPI Forum added an explicit statement that users are
       required to call MPI_Errhandler_free when the return value from this routine is no  longer
       needed.   This  behavior  is  similar  to  the other MPI routines for getting objects; for
       example, MPI_Comm_group requires that the user call MPI_Group_free when the group returned
       by MPI_Comm_group is no longer needed.

THREAD AND INTERRUPT SAFETY

       This routine is thread and interrupt safe only if no MPI routine that updates or frees the
       same MPI object may be called concurrently with this routine.

       The MPI standard defined a thread-safe interface but this does not mean that all  routines
       may  be  called  without  any  thread locks.  For example, two threads must not attempt to
       change the contents of the same MPI_Info object concurrently.  The user is responsible  in
       this  case  for using some mechanism, such as thread locks, to ensure that only one thread
       at a time makes use of this routine.

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 guarantee 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 ).
       MPI_ERR_COMM
              - Invalid communicator.  A common error is to use a null  communicator  in  a  call
              (not even allowed in MPI_Comm_rank ).
       MPI_ERR_OTHER
              - Other error; use MPI_Error_string to get more information about this error code.

                                            2/22/2022                  MPI_Comm_get_errhandler(3)