org.jcsp.lang
Class AltingConnectionServerImpl<T>

java.lang.Object
  extended by org.jcsp.lang.Guard
      extended by org.jcsp.lang.AltingConnectionServer<T>
          extended by org.jcsp.lang.AltingConnectionServerImpl<T>
All Implemented Interfaces:
ConnectionServer<T>

public class AltingConnectionServerImpl<T>
extends AltingConnectionServer<T>

This class does not need to be used by standard JCSP users. It is exposed so that the connection mechanism can be extended for custom connections.

Author:
Quickstone Technologies Limited

Field Summary
protected static int SERVER_STATE_CLOSED
          Server state.
protected static int SERVER_STATE_OPEN
          Server state.
protected static int SERVER_STATE_RECEIVED
          Server state.
 
Fields inherited from interface org.jcsp.lang.ConnectionServer
FACTORY
 
Constructor Summary
protected AltingConnectionServerImpl(AltingChannelInput<org.jcsp.lang.ConnectionMessage<T>> openIn, AltingChannelInput<org.jcsp.lang.ConnectionMessage<T>> furtherRequestIn)
          Constructs a new server instance.
 
Method Summary
protected  int getServerState()
           
 void reply(T data)
          Sends some data back to the client after a request has been received but keeps the connection open.
 void reply(T data, boolean close)
          Sends some data back to the client after a request has been received.
 void replyAndClose(T data)
          Sends some data back to the client and closes the connection.
 T request()
          Receives some data from a client once a connection has been established.
 
Methods inherited from class org.jcsp.lang.AltingConnectionServer
getAltingChannel, pending, setAltingChannel
 
Methods inherited from class org.jcsp.lang.Guard
schedule
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

SERVER_STATE_CLOSED

protected static final int SERVER_STATE_CLOSED
Server state. The server is initially CLOSED the first request will take it to the RECEIVED state. A reply will take it back to OPEN or CLOSED depending on the mode of reply. From the OPEN or CLOSED state a further request can occur.

See Also:
Constant Field Values

SERVER_STATE_OPEN

protected static final int SERVER_STATE_OPEN
Server state. The server is initially CLOSED the first request will take it to the RECEIVED state. A reply will take it back to OPEN or CLOSED depending on the mode of reply. From the OPEN or CLOSED state a further request can occur.

See Also:
Constant Field Values

SERVER_STATE_RECEIVED

protected static final int SERVER_STATE_RECEIVED
Server state. The server is initially CLOSED the first request will take it to the RECEIVED state. A reply will take it back to OPEN or CLOSED depending on the mode of reply. From the OPEN or CLOSED state a further request can occur.

See Also:
Constant Field Values
Constructor Detail

AltingConnectionServerImpl

protected AltingConnectionServerImpl(AltingChannelInput<org.jcsp.lang.ConnectionMessage<T>> openIn,
                                     AltingChannelInput<org.jcsp.lang.ConnectionMessage<T>> furtherRequestIn)
Constructs a new server instance. This must be called by a subclass which is responsible for creating the channels.

Method Detail

request

public T request()
          throws IllegalStateException
Receives some data from a client once a connection has been established. This will block until the client calls request(Object) but by establishing a connection.

Returns:
the Object sent by the client.
Throws:
IllegalStateException

reply

public void reply(T data)
           throws IllegalStateException
Sends some data back to the client after a request has been received but keeps the connection open. After calling this method, the server should call recieve() to receive a further request.

Parameters:
data - the data to send to the client.
Throws:
IllegalStateException

reply

public void reply(T data,
                  boolean close)
           throws IllegalStateException
Sends some data back to the client after a request has been received. The closed parameter indicates whether or not the connection should be closed. The connection will be closed iff close is true.

Parameters:
data - the data to send to the client.
close - boolean indicating whether or not the connection should be closed.
Throws:
IllegalStateException

replyAndClose

public void replyAndClose(T data)
                   throws IllegalStateException
Sends some data back to the client and closes the connection. This method will not block. After calling this method, the server may call accept() in order to allow another connection to this server to be established. If this method did not take any data to send back to the client, and the server was meant to call reply(Object) followed by a close(), then there would be a race hazard at the client as it would not know whether the connection had remained open or not.

Parameters:
data - the data to send back to client.
Throws:
IllegalStateException

getServerState

protected int getServerState()


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