Comm

public class Comm {

  // Communicator Management

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

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

  public Group group() throws MPJException {...}  // (section "Group management" of spec)

  public static int compare(Comm comm1, Comm comm2) throws MPJException {...}

  public Object clone() {...}

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


  // Inter-communication

  public boolean testInter() throws MPJException {...}

  public Intercomm createIntercomm(Comm localComm, int localLeader,
                                   int remoteLeader, int tag) throws MPJException {...}


  // Caching

  public Object attrGet(int keyval) throws MPJException {...}


  // Blocking Send and Receive operations

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

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


  // Communication Modes

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

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

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


  // Nonblocking communication

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

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

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

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

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


  // Probe and cancel

  public Status iprobe(int source, int tag) throws MPJException {...}

  public Status probe(int source, int tag) throws MPJException {...}


  // Persistent communication requests

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

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

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

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

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


  // 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 MPJException {...}

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

  // Pack and unpack

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

  byte[] pack(Object inbuf, int offset, int incount, Datatype datatype)
                      throws MPJException {...}

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

  public int packSize(int incount, Datatype datatype) throws MPJException {...}


  // Process Topologies

  int topoTest() throws MPJException {...}


  // Environmental Management

  public static void errorhandlerSet(Errhandler errhandler) throws MPJException {...}

  public static Errhandler errorhandlerGet() throws MPJException {...}

  void abort(int errorcode) throws MPJException {...}

  ...
}