MPI_Comm_compare(3)                Open MPI                MPI_Comm_compare(3)



NAME
       MPI_Comm_compare  -  Compares two communicators.


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Comm_compare(MPI_Comm comm1, MPI_Comm comm2, int *result)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_COMM_COMPARE(COMM1, COMM2, RESULT, IERROR)
            INTEGER   COMM1, COMM2, RESULT, IERROR


C++ Syntax
       #include <mpi.h>
       static int Comm::Compare(const Comm& comm1, const Comm& comm2)


INPUT PARAMETERS
       comm1     Comm1 (handle).

       comm2     Comm2 (handle).


OUTPUT PARAMETERS
       result    Result of comparison (integer).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPI_IDENT results if and only if comm1 and comm2 are handles for the
       same object (identical groups and same contexts). MPI_CONGRUENT results
       if the underlying groups are identical in constituents and rank order;
       these communicators differ only by context. MPI_SIMILAR results of the
       group members of both communicators are the same but the rank order
       differs. MPI_UNEQUAL results otherwise.


ERRORS
       Almost all MPI routines return an error value; C routines as the value
       of the function and Fortran routines in the last argument. C++
       functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       Before the error value is returned, the current MPI error handler is
       called. By default, this error handler aborts the MPI job, except for
       I/O function errors. The error handler may be changed with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN
       may be used to cause error values to be returned. Note that MPI does
       not guarantee that an MPI program can continue past an error.





1.4.1                            Jan 14, 2010              MPI_Comm_compare(3)
