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