hmi.bml.bridge
Class TCPIPRealizerBridgeClient

java.lang.Object
  hmi.bml.bridge.TCPIPRealizerBridgeClient

All Implemented Interfaces:

RealizerBridge, Runnable

public final class TCPIPRealizerBridgeClient
extends Object
implements RealizerBridge, Runnable

A RealizerBridge that uses a tcp/ip connection to provide transparent access to a BML Realizer running on a remote machine. The connection is "self-healing". Detailed documentation can be found in the project report.

Author:

Dennis Reidsma

Nested Class Summary

private class	TCPIPRealizerBridgeClient.FeedbackReader The process that reads feedback from the network connection, and puts it in the feedback queue.
private class	TCPIPRealizerBridgeClient.FeedbackRedirector The process that reads feedback from the feedback queue, and sends it to the BML feedback listeners.

Field Summary

private ConcurrentLinkedQueue<String>	bmlRequestQ Incoming BML Requests from the application are stored here.
private Socket	bmlSendSocket
private InetSocketAddress	bmlSendSocketAddress
private PrintWriter	bmlSendWriter
private static int	CONNECT_RETRY_WAIT
private Object	connectionLock Locking object for the states of the main networking loop.
private BMLFeedbackManager	fbManager
private static long	FEEDBACK_REDIRECT_WAIT_MILLI Sleeping time of the FeedbackRedirector if the feedback queue is empty
private Object	feedbackLock Locking object for the feedbacklisteners -- needed to avoid a situation where feedback is sent out simultaneously with setting the feedbacklisteners.
private ConcurrentLinkedQueue<BMLFeedback>	feedbackQ Incoming feedback from the server are stored here.
private TCPIPRealizerBridgeClient.FeedbackReader	feedbackReader
private Thread	feedbackReaderThread
private BufferedReader	feedbackReadReader
private ServerSocket	feedbackReadServerSocket
private Socket	feedbackReadSocket
private TCPIPRealizerBridgeClient.FeedbackRedirector	feedbackRedirector redirects feedback that has come in over the socket to the listeners
private Thread	feedbackRedirectorThread the thread under which the feedbackRedirector runs.
private boolean	isconnected Internal state var: true if a conenction to a server is active
private static org.slf4j.Logger	logger
private boolean	mustconnect Internal state var: true if a connect request has been given
private boolean	mustdisconnect Internal state var: true if a disconnect request has been given
private boolean	mustshutdown Internal state var: true if a shutdown request has been given
private long	nextMainLoopWait Waiting time for next run() loop.
private ServerInfo	serverInfo Internal state var: The ServerInfo for the connection that must be set up (see #mustconnect).
private static int	SOCKET_TIMEOUT

Constructor Summary

TCPIPRealizerBridgeClient()
Set the state variables to appropriate values, start the main processing loop, and start the processing loop that will deliver feedback messages to the BML Feedback listeners.

Method Summary

void	addListeners(BMLListener... bmlListeners) Listeners must be stored; they will get updates from the feedbackRedirectionThread
void	connect(ServerInfo serverInfo) May return before connection is actually made.
void	disconnect() Instigates disconnection procedure.
private void	doconnect() Attempt to connect to server, given ServerInfo.
private void	dodisconnect() Disconnect from server (if connected); close feedback reading thread; return when processes finished.
private void	dosendBML(String bmlRequest) Send given BML request.
private void	doshutdown() Disconnect.
private void	failConnect(String msg) Fail and don't try again
protected ServerInfo	getServerInfo()
boolean	isConnected() Returns true iff there is a connection to a server active (and has not been lost).
void	performBML(String bmlString) Add BML request to the queue and return.
private void	retryConnect(String msg) Error connecting, prepare to retry
void	run() The main loop!
void	shutdown() Instigates total shutdown.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

fbManager

private BMLFeedbackManager fbManager

logger

private static org.slf4j.Logger logger

FEEDBACK_REDIRECT_WAIT_MILLI

private static final long FEEDBACK_REDIRECT_WAIT_MILLI

Sleeping time of the FeedbackRedirector if the feedback queue is empty

See Also:

Constant Field Values

SOCKET_TIMEOUT

private static final int SOCKET_TIMEOUT

See Also:

Constant Field Values

CONNECT_RETRY_WAIT

private static final int CONNECT_RETRY_WAIT

See Also:

Constant Field Values

bmlRequestQ

private ConcurrentLinkedQueue<String> bmlRequestQ

Incoming BML Requests from the application are stored here. The main networking loop will get these requests and send them to the server if a connection is available.

connectionLock

private Object connectionLock

Locking object for the states of the main networking loop.

isconnected

private boolean isconnected

Internal state var: true if a conenction to a server is active

mustshutdown

private boolean mustshutdown

Internal state var: true if a shutdown request has been given

mustconnect

private boolean mustconnect

Internal state var: true if a connect request has been given

serverInfo

private ServerInfo serverInfo

Internal state var: The ServerInfo for the connection that must be set up (see #mustconnect).

mustdisconnect

private boolean mustdisconnect

Internal state var: true if a disconnect request has been given

nextMainLoopWait

private long nextMainLoopWait

Waiting time for next run() loop.

bmlSendSocketAddress

private InetSocketAddress bmlSendSocketAddress

bmlSendSocket

private Socket bmlSendSocket

bmlSendWriter

private PrintWriter bmlSendWriter

feedbackReadServerSocket

private ServerSocket feedbackReadServerSocket

feedbackReadSocket

private Socket feedbackReadSocket

feedbackReadReader

private BufferedReader feedbackReadReader

feedbackReader

private TCPIPRealizerBridgeClient.FeedbackReader feedbackReader

feedbackReaderThread

private Thread feedbackReaderThread

feedbackLock

private Object feedbackLock

Locking object for the feedbacklisteners -- needed to avoid a situation where feedback is sent out simultaneously with setting the feedbacklisteners.

feedbackRedirector

private TCPIPRealizerBridgeClient.FeedbackRedirector feedbackRedirector

redirects feedback that has come in over the socket to the listeners

feedbackRedirectorThread

private Thread feedbackRedirectorThread

the thread under which the feedbackRedirector runs.

feedbackQ

private ConcurrentLinkedQueue<BMLFeedback> feedbackQ

Incoming feedback from the server are stored here. The feedbackredirector loop will get tehm and send them to the BML FeedbackListeners.

Constructor Detail

TCPIPRealizerBridgeClient

public TCPIPRealizerBridgeClient()

Set the state variables to appropriate values, start the main processing loop, and start the processing loop that will deliver feedback messages to the BML Feedback listeners. The last loop, the one reading feedback from the socket, is not started until a connection is made.

Method Detail

disconnect

public void disconnect()

Instigates disconnection procedure. After disconnecting, client goes into a waiting state, and may be asked to connect to a server again at a later time.

connect

public void connect(ServerInfo serverInfo)

May return before connection is actually made. However, implementation guarantees that performBML request made AFTER connect request, will be sent over that connection (if the connection is successful)

getServerInfo

protected ServerInfo getServerInfo()

shutdown

public void shutdown()

Instigates total shutdown. May return from this method before shutdown is completed. Shutdown process will terminate all connections and threads for this client.

isConnected

public boolean isConnected()

Returns true iff there is a connection to a server active (and has not been lost).

addListeners

public void addListeners(BMLListener... bmlListeners)

Listeners must be stored; they will get updates from the feedbackRedirectionThread

Specified by:

addListeners in interface RealizerBridge

performBML

public void performBML(String bmlString)

Add BML request to the queue and return. Sending will happen in the main networking loop.

Specified by:

performBML in interface RealizerBridge

run

public void run()

The main loop!

Specified by:

run in interface Runnable

dodisconnect

private void dodisconnect()

Disconnect from server (if connected); close feedback reading thread; return when processes finished. Called from the run() loop.

doconnect

private void doconnect()

Attempt to connect to server, given ServerInfo. Start feedback reading loop. Log results. If successful, isconnected is true; else, clean up everything, try again enxt round with wait = 1000. Called from the run() loop.

failConnect

private void failConnect(String msg)

Fail and don't try again

retryConnect

private void retryConnect(String msg)

Error connecting, prepare to retry

doshutdown

private void doshutdown()

Disconnect. Clean up feedbackredirectionloop. Called from the run() loop.

dosendBML

private void dosendBML(String bmlRequest)

Send given BML request. If fail: drop request, fire off feedback, disconnect.