NAME¶
MPI_Abort - Terminates MPI execution environment
SYNOPSIS¶
#include <mpi.h>
int MPI_Abort(MPI_Comm comm, int errcode)
- 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.
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