MPICommtestinter(3OpenMPI) MPICommtestinter(3OpenMPI)

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


SSYYNNTTAAXX
CC SSyynnttaaxx
       #include 
       int MPICommtestinter(MPIComm comm, int *flag)


FFoorrttrraann SSyynnttaaxx
       INCLUDE 'mpif.h'
       MPICOMMTESTINTER(COMM, FLAG, IERROR)
            INTEGER   COMM, IERROR
            LOGICAL   FLAG


CC++++ SSyynnttaaxx
       #include 
       bool Comm::Isinter() const


IINNPPUUTT PPAARRAAMMEETTEERR
       comm      Communicator (handle).


OOUUTTPPUUTT PPAARRAAMMEETTEERRSS
       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 communica-
       tion 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:

       MPICommsize  Returns the size of the local group.
       MPICommgroup Returns the local group.
       MPICommrank  Returns the rank in the local group.

       To return the remote group and remote group size of an inter-communica-
       tor,  use the MPICommremotegroup and MPICommremotesize functions.

       The operation MPICommcompare is valid  for  intercommunicators.  Both
       communicators  must  be  either  intra-  or intercommunicators, or else
       MPIUNEQUAL results. Both corresponding local and  remote  groups  must
       compare  correctly to get the results MPICONGRUENT and MPISIMILAR. In
       particular, it is possible for MPISIMILAR 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: MPICommremotesize, MPICommremotegroup.

       The       intercommunicator       accessors       (MPICommtestinter,
       MPICommremotesize,  MPICommremotegroup) are all local operations.


EERRRROORRSS
       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::ERRORSTHROWEXCEPTIONS, 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
       MPICommseterrhandler; the predefined error handler MPIERRORSRETURN
       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
       MPICommremotegroup
       MPICommremotesize
       MPIIntercommcreate
       MPIIntercommmerge




Open MPI 1.2                    September 2006   MPICommtestinter(3OpenMPI)