osx man page for mpi_comm_test_inter

MPI_Comm_test_inter(3OpenMPI)											     MPI_Comm_test_inter(3OpenMPI)

NAME
       MPI_Comm_test_inter  - Tests to see if a comm is an intercommunicator.

SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Comm_test_inter(MPI_Comm comm, int *flag)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_COMM_TEST_INTER(COMM, FLAG, IERROR)
	    INTEGER   COMM, IERROR
	    LOGICAL   FLAG

C++ Syntax
       #include <mpi.h>
       bool Comm::Is_inter() const

INPUT PARAMETER
       comm	 Communicator (handle).

OUTPUT PARAMETERS
       flag	(Logical.)

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION
       This  local routine allows the calling process to determine the type of a communicator. It returns true for an intercommunicator, false for
       an intracommunicator.

       The type of communicator also affects the value returned by three other functions.  When dealing with an intracommunicator (enables  commu-
       nication  within a single group), the functions listed below return the expected values, group size, group, and rank.  When dealing with an
       inter-communicator, however, they return the following values:

       MPI_Comm_size  Returns the size of the local group.
       MPI_Comm_group Returns the local group.
       MPI_Comm_rank  Returns the rank in the local group.

       To return the remote group and remote group size of an inter-communicator, use the  MPI_Comm_remote_group  and  MPI_Comm_remote_size  func-
       tions.

       The  operation  MPI_Comm_compare  is  valid for intercommunicators. Both communicators must be either intra- or intercommunicators, or else
       MPI_UNEQUAL results. Both corresponding local and remote groups must compare correctly to get the results MPI_CONGRUENT and MPI_SIMILAR. In
       particular, it is possible for MPI_SIMILAR to result because either the local or remote groups were similar but not identical.

       The following accessors provide consistent access to the remote group of an intercommunicator: MPI_Comm_remote_size, MPI_Comm_remote_group.

       The intercommunicator accessors (MPI_Comm_test_inter, MPI_Comm_remote_size, MPI_Comm_remote_group) are all local operations.

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++ func-
       tions 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.

SEE ALSO
       MPI_Comm_remote_group
       MPI_Comm_remote_size
       MPI_Intercomm_create
       MPI_Intercomm_merge

Open MPI 1.2							  September 2006				     MPI_Comm_test_inter(3OpenMPI)