Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

RedHat 9 (Linux i386) - man page for mpi_comm_compare (redhat section 3)

MPI_Comm_compare(3)						      LAM/MPI						       MPI_Comm_compare(3)

NAME
MPI_Comm_compare - Compares two communicators
SYNOPSIS
#include <mpi.h> int MPI_Comm_compare(MPI_Comm c1, MPI_Comm c2, int *result)
INPUT PARAMETERS
c1 - comm1 (handle) c2 - comm2 (handle)
OUTPUT PARAMETER
result - integer which is MPI_IDENT if the contexts and groups are the same, MPI_CONGRUENT if different contexts but identical groups, MPI_SIMILAR if different contexts but similar groups, and MPI_UNEQUAL otherwise USING 'MPI_COMM_NULL' WITH 'MPI_COMM_COMPARE' It is an error to use MPI_COMM_NULL as one of the arguments to MPI_Comm_compare . The relevant sections of the MPI standard are (2.4.1 Opaque Objects) A null handle argument is an erroneous IN argument in MPI calls, unless an exception is explicitly stated in the text that defines the function. (5.4.1. Communicator Accessors) <no text in MPI_COMM_COMPARE allowing a null handle>
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
If an error occurs in an MPI function, the current MPI error handler is called to handle it. By default, this error handler aborts the MPI job. The error handler may be changed with MPI_Errhandler_set ; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned (in C and Fortran; this error handler is less useful in with the C++ MPI bindings. The predefined error handler MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value needs to be recovered). Note that MPI does not guarantee that an MPI program can continue past an error. 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. The C++ bindings for MPI do not return error values; instead, error values are communicated by throwing exceptions of type MPI::Exception (but not by default). Exceptions are only thrown if the error value is not MPI::SUCCESS . Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI functions will return upon an error, there will be no way to recover what the actual error value was. MPI_SUCCESS - No error; MPI routine completed successfully. 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_ARG - Invalid argument. Some argument is invalid and is not identified by a specific error class. This is typically a NULL pointer or other such error.
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/sow- ing/sowing.tar.gz ), the initial formatting, and some initial text for most of the MPI-1 man pages.
LOCATION
ccmp.c
LAM
/MPI 6.5.8 11/10/2002 MPI_Comm_compare(3)