Intracomm and Intercomm

public class Intracomm extends Comm {

  public Object clone() { ... }

  public Intracomm create(Group group) throws MPJException {...}

  public Intracomm split(int colour, int key) throws MPJException {...}

  // Collective communication

  public void barrier() throws MPJException {...}

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

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

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

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

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

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

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

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

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

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

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

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

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


  // Topology Constructors

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

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

  ...
}

public class Intercomm extends Comm {

  public Object clone() { ... }

  // Inter-communication

  public int remoteSize() throws MPJException {...}

  public Group remoteGroup() throws MPJException {...}

  public Intracomm merge(boolean high) throws MPJException {...}

  ...
}