NAME

       MPI_Abort -  Terminates MPI execution environment

SYNOPSIS

       #include <mpi.h>
       int MPI_Abort(MPI_Comm comm, int errcode)

INPUT PARAMETERS

       comm   - communicator of tasks to abort
       errcode
              - error code to return to invoking environment

NOTES

       Makes  a  "best  attempt"  to terminate all MPI processes associated with the communicator
       comm ; for non-IMPI jobs,  this  will  terminate  all  processes.   MPI_Abort  will  hang,
       however, if the LAM daemon on the node on which a rank was running has died.  For example,
       if a node gets powered off in the middle of an MPI run and MPI_Abort is  invoked,  it  may
       hang trying to contact the LAM daemon on the downed node.

       In the case of an IMPI job, in addition to terminating all local IMPI procs, this function
       will also send an abort message to the local IMPI host, which will, in turn send "closing"
       messages  to  all  the  other  IMPI hosts.  Their behavior upon receipt of these "closing"
       messages is implementation dependant.

       If the LAM IMPI host receives a premature "closing" message from a remote  IMPI  host,  it
       will  attempt  to  continue  processing.   Any new messages to that host will likely hang,
       however.

'ERRCODE' IS SPLIT INTO THREE SECTIONS

       lower 8 bits: error class
              - . next 9 bits: function enumeration (there are over 300 MPI functions; it takes 9
              bits to represent all possibilities)
       upper 15 bits: error code
              -  If  the error class is nonzero, the error code is the POSIX return value for the
              program (i.e., exit(error_code) is eventually called to terminate the program).  If
              the  error  class  is  zero,  errcode is returned as the POSIX return value for the
              program.

              This is mainly because MPI_Abort is used internally in LAM/MPI to  abort  MPI  upon
              error;  LAM  packs  all  three  pieces of data into the errcode.  Users who wish to
              return a specific value from the program

SHOULD USE SOMETHING SIMILAR TO

       return ((return_code << 17) + 1);

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.

MORE INFORMATION

       For  more information, please see the official MPI Forum web site, which contains the text
       of both the MPI-1 and MPI-2 standards.  These documents contain detailed information about
       each MPI function (most of which is not duplicated in these man pages).

       http://www.mpi-forum.org/

ACKNOWLEDGEMENTS

       The  LAM  Team  would  like the thank the MPICH Team for the handy program to generate man
       pages  ("doctext"  from  ftp://ftp.mcs.anl.gov/pub/sowing/sowing.tar.gz  ),  the   initial
       formatting, and some initial text for most of the MPI-1 man pages.

LOCATION

       abort.c