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

LAM/MPI 7.1.4                                       6/24/2006                                       MPI_Abort(3)