package jicos.system;

import java.rmi.Remote;
import java.rmi.RemoteException;
/** Allows <CODE>ProductionNetwork</CODE>, <CODE>Producer</CODE>, and <CODE>Task</CODE> to interact with TaskServer.
 */
public interface TaskServer extends Remote
{
    /** Service name used in rmiregistry.
 */
    public static String NAME = "TaskServer";
    
    /** Not part of API.
     * @throws RemoteException This is a remote method.
     * @return ConsumerInfo - Please see {@link ConsumerInfo}.
     */    
    public SessionInfo getState() throws RemoteException;
	
    /** Producer gets a Task.
     * @return A Task object.
     * @param taskInfo The <CODE>TaskId</CODE> of the <CODE>Task</CODE> that was just completed by the <CODE>Producer</CODE>. A <CODE>null</CODE> value is used to convey that this is the 1st <CODE>getTask</CODE> request by this <CODE>Producer</CODE>: There is no <CODE>Task</CODE> that was just completed.
     * @throws RemoteException It is a <CODE>Remote</CODE> method.
     */    
    //public /*Task*/ void getTask ( TaskInfo taskInfo, Bag outbox ) throws RemoteException;
    
    public Task[] getTasks() throws RemoteException;

    public void registerChild( int child, TaskServer childServer ) 
           throws RemoteException;
    
    /** Not part of API.
     *
     * (<CODE>ProductionNetwork</CODE> registers a new <CODE>Consumer</CODE> as the
     * current owner of the <CODE>ProductionNetwork</CODE>;
     * reset state for new computation.)
     * @param consumerInfo Container of consumer information. Please see {@link ConsumerInfo}.
     * @throws RemoteException This is a Remote method.
     */
    public void registerClient ( SessionInfo sessionInfo ) 
           throws RemoteException;

    /** Not part of API.
     *
     * (Register Producer.)
     * @param p Remote reference to the producer.
     * @param i The container of information associated with a producer that is maintained by
     * the TaskServer.
     * @throws RemoteException This is a Remote method.
     * @return A container of consumer information. Please see {@link ConsumerInfo}.
     */
    public SessionInfo registerProducer ( Cell h, HostInfo i ) throws RemoteException;
	
     /** Set a value, <I>v</I>, for the <I>i</I>th argument of successor task <I>t</I>:
      * Pseudo-code: <CODE>t.inputs[i] = v;</CODE>
      * @param taskId of the task whose input is to be set.
      * @param index of inputs of the task whose input is to be set.
      * @param v is the argument value.
      * @throws RemoteException This is a Remote method.
      */
    public void setArg ( TaskId taskId, int index, Object v ) throws RemoteException;
    
    /** Not part of API.
     * @param initiator refers to the neighboring TaskServer that is proposing the new value for the Shared object.
     * @param shared The proposed new value.
     * @throws RemoteException This is a Remote method.
     */
    public void setShared ( Shared shared, int initiator ) throws RemoteException;

    /** Not part of the API.
     *
     * (Unregister owner of ProductionNetwork with TaskServer;
     * reset state for new computation.)
     * @throws RemoteException This is a Remote method.
     * @return ConsumerStatistics contains quantities of ProductionNetwork resources consumed.
     */
     //public SessionStatistics unregisterClient () throws RemoteException;

    /** Not part of API.
     *
     * (Unregister Host. Will not be used remotely until screensaver/daemon
     * incorporates it.)
     * @param p Remote reference to the Host that is unregistering.
     * @throws RemoteException This is a Remote method.
     */
    public void unregisterProducer ( Cell h ) throws RemoteException;
}