Intracomm and Intercomm

public class Intracomm extends Comm {

  public Object clone() { ... }

  public Intracomm Create(Group group) throws MPIException {...}

  public Intracomm Split(int colour, int key) throws MPIException {...}

  // Collective communication

  public void Barrier() throws MPIException {...}

  public void Bcast(Object buffer, int offset, int count,
                    Datatype datatype, int root)
                                            throws MPIException {...}

  public void Gather(Object sendbuf, int sendoffset,
                     int sendcount, Datatype sendtype,
                     Object recvbuf, int recvoffset,
                     int recvcount, Datatype recvtype, int root) 
                                            throws MPIException {...}

  public void Gatherv(Object sendbuf, int sendoffset,
                      int sendcount, Datatype sendtype,
                      Object recvbuf, int recvoffset,
                      int [] recvcount, int [] displs,
                      Datatype recvtype, int root) 
                                            throws MPIException {...}

  public void Scatter(Object sendbuf, int sendoffset,
                      int sendcount, Datatype sendtype,
                      Object recvbuf, int recvoffset,
                      int recvcount, Datatype recvtype, int root) 
                                            throws MPIException {...}

  public void Scatterv(Object sendbuf, int sendoffset,
                       int [] sendcount, int [] displs,
                       Datatype sendtype,
                       Object recvbuf, int recvoffset,
                       int recvcount, Datatype recvtype, int root) 
                                            throws MPIException {...}

  public void Allgather(Object sendbuf, int sendoffset,
                        int sendcount, Datatype sendtype,
                        Object recvbuf, int recvoffset,
                        int recvcount, Datatype recvtype) 
                                            throws MPIException {...}

  public void Allgatherv(Object sendbuf, int sendoffset,
                         int sendcount, Datatype sendtype,
                         Object recvbuf, int recvoffset,
                         int [] recvcounts, int [] displs,
                         Datatype recvtype) throws MPIException {...}

  public void Alltoall(Object sendbuf, int sendoffset,
                       int sendcount, Datatype sendtype,
                       Object recvbuf, int recvoffset,
                       int recvcount, Datatype recvtype) 
                                            throws MPIException {...}

  public void Alltoallv(Object sendbuf, int sendoffset,
                        int [] sendcount, int [] sdispls,
                        Datatype sendtype,
                        Object recvbuf, int recvoffset,
                        int [] recvcount, int [] rdispls,
                        Datatype recvtype) throws MPIException {...}

  public void Reduce(Object sendbuf, int sendoffset,
                     Object recvbuf, int recvoffset,
                     int count, Datatype datatype,
                     Op op, int root) throws MPIException {...}

  public void Allreduce(Object sendbuf, int sendoffset,
                        Object recvbuf, int recvoffset,
                        int count, Datatype datatype,
                        Op op) throws MPIException {...}

  public void Reduce_scatter(Object sendbuf, int sendoffset,
                             Object recvbuf, int recvoffset,
                             int [] recvcounts, Datatype datatype,
                             Op op) throws MPIException {...}

  public void Scan(Object sendbuf, int sendoffset,
                   Object recvbuf, int recvoffset,
                   int count, Datatype datatype,
                   Op op) throws MPIException {...}


  // Topology Constructors

  public Graphcomm Create_graph(int [] index, int [] edges,
                                boolean reorder) 
                                            throws MPIException {...}

  public Cartcomm Create_cart(int [] dims, boolean [] periods,
                              boolean reorder) 
                                            throws MPIException {...}

  ...
}

public class Intercomm extends Comm {

  public Object clone() { ... }

  // Inter-communication

  public int Remote_size() throws MPIException {...}

  public Group Remote_group() throws MPIException {...}

  public Intracomm Merge(boolean high) throws MPIException {...}

  ...
}