Comm

public class Comm {

  // Communicator Management

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

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

  public Group Group() throws MPIException {...}
                                        // (see ``Group management'')

  public static int Compare(Comm comm1, Comm comm2)
                                            throws MPIException {...}

  public Object clone() {...}

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

  public boolean Is_null() {...}


  // Inter-communication

  public boolean Test_inter() throws MPIException {...}

  public Intercomm Create_intercomm(Comm local_comm, int local_leader,
                                    int remote_leader, int tag)
                                             throws MPIException {...}

  // Caching

  public Object Attr_get(int keyval) throws MPIException {...}


  // Blocking Send and Receive operations

  public void Send(Object buf, int offset, int count, 
                   Datatype datatype, int dest, int tag)
                                             throws MPIException {...}

  public Status Recv(Object buf, int offset, int count, 
                     Datatype datatype, int source, int tag)
                                             throws MPIException {...}


  // Communication Modes

  public void Bsend(Object buf, int offset, int count, 
                    Datatype datatype, int dest, int tag)
                                             throws MPIException {...}

  public void Ssend(Object buf, int offset, int count, 
                    Datatype datatype, int dest, int tag) 
                                             throws MPIException {...}

  public void Rsend(Object buf, int offset, int count, 
                    Datatype datatype, int dest, int tag) 
                                             throws MPIException {...}


  // Nonblocking communication

  public Request Isend(Object buf, int offset, int count, 
                       Datatype datatype, int dest, int tag) 
                                             throws MPIException {...}

  public Request Ibsend(Object buf, int offset, int count, 
                        Datatype datatype, int dest, int tag) 
                                             throws MPIException {...}

  public Request Issend(Object buf, int offset, int count, 
                        Datatype datatype, int dest, int tag) 
                                             throws MPIException {...}

  public Request Irsend(Object buf, int offset, int count, 
                        Datatype datatype, int dest, int tag) 
                                             throws MPIException {...}

  public Request Irecv(Object buf, int offset, int count, 
                       Datatype datatype, int source, int tag) 
                                             throws MPIException {...}


  // Probe and cancel

  public Status Iprobe(int source, int tag) throws MPIException {...}

  public Status Probe(int source, int tag) throws MPIException {...}


  // Persistent communication requests

  public Prequest Send_init(Object buf, int offset, int count, 
                            Datatype datatype, int dest, int tag) 
                                            throws MPIException {...}

  public Prequest Bsend_init(Object buf, int offset, int count, 
                             Datatype datatype, int dest, int tag) 
                                            throws MPIException {...}

  public Prequest Ssend_init(Object buf, int offset, int count, 
                             Datatype datatype, int dest, int tag) 
                                            throws MPIException {...}

  public Prequest Rsend_init(Object buf, int offset, int count, 
                             Datatype datatype, int dest, int tag) 
                                            throws MPIException {...}

  public Prequest Recv_init(Object buf, int offset, int count, 
                            Datatype datatype, int source, int tag) 
                                            throws MPIException {...}


  // Send-receive

  public Status Sendrecv(Object sendbuf, int sendoffset,
                         int sendcount, Datatype sendtype,
                         int dest, int sendtag,
                         Object recvbuf, int recvoffset,
                         int recvcount, Datatype recvtype,
                         int source, int recvtag) 
                                            throws MPIException {...}

  public Status Sendrecv_replace(Object buf, int offset,
                                 int count, Datatype datatype,
                                 int dest, int sendtag,
                                 int source, int recvtag) 
                                            throws MPIException {...}

  // Pack and unpack

  public int Pack(Object inbuf, int offset, int incount, 
                  Datatype datatype,
                  byte [] outbuf, int position)
                                            throws MPIException {...}

  public int Unpack(byte [] inbuf, int position,
                    Object outbuf, int offset, int outcount, 
                    Datatype datatype) throws MPIException {...}

  public int Pack_size(int incount, Datatype datatype) 
                                            throws MPIException {...}


  // Process Topologies

  int Topo_test() throws MPIException {...}


  // Environmental Management

  public void Errorhandler_set(Errhandler errhandler)
                                            throws MPIException {...}

  public Errhandler Errorhandler_get() throws MPIException {...}

  void Abort(int errorcode) throws MPIException {...}

  ...
}