org.openflow.gui.net
Class BackendConnection<MSG_TYPE extends Message>

java.lang.Object
  java.lang.Thread
      org.openflow.gui.net.BackendConnection<MSG_TYPE>

All Implemented Interfaces:

java.lang.Runnable

public class BackendConnection<MSG_TYPE extends Message>
extends java.lang.Thread

Connects to a server instance to receive stats and send commands.

Author:

David Underhill

Nested Class Summary

class

BackendConnection.NetStats Statistics about this connection.

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

protected java.util.concurrent.ConcurrentHashMap<java.lang.Integer,OFGMessage>	outstandingStatefulPollRequests stateful messages which are being polled by the backend for us
protected java.util.concurrent.ConcurrentHashMap<java.lang.Integer,OFGMessage>	outstandingStatefulRequests messages which are expecting a stateful response
static boolean	PRINT_MESSAGES whether to print messages we send and receive
static int	RETRY_WAIT_MSEC_MAX maximum time to wait between tries to get connected

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

BackendConnection(MessageProcessor<MSG_TYPE> mp, java.lang.String ip, int port)
Connect to the server at the specified address and port.

Method Summary

boolean	isConnected() returns true if the connection to the server is currently alive
boolean	isShutdown() gets whether the connection has been shutdown yet
OFGMessage	popAssociatedStatefulRequest(int xid) Returns the request sent with the specified transaction ID, if any.
void	reconnect() tells the connection to disconnect and then connect again
void	run() The BackendConnection thread will connect to the server and then continuously read from the socket and pass on received messages to the protocol handler.
protected void	scrubExpiredStatefulRequests() Remove cached stateful requests which have been cached for longer than getRequestLifetime()
void	sendMessage(OFGMessage m) Tries to send a message and sets the transaction ID of the message to the next available transaction ID.
void	shutdown() tells the connection to shut down as soon as possible

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

PRINT_MESSAGES

public static final boolean PRINT_MESSAGES

whether to print messages we send and receive

See Also:

Constant Field Values

RETRY_WAIT_MSEC_MAX

public static final int RETRY_WAIT_MSEC_MAX

maximum time to wait between tries to get connected

See Also:

Constant Field Values

outstandingStatefulRequests

protected java.util.concurrent.ConcurrentHashMap<java.lang.Integer,OFGMessage> outstandingStatefulRequests

messages which are expecting a stateful response

outstandingStatefulPollRequests

protected java.util.concurrent.ConcurrentHashMap<java.lang.Integer,OFGMessage> outstandingStatefulPollRequests

stateful messages which are being polled by the backend for us

Constructor Detail

BackendConnection

public BackendConnection(MessageProcessor<MSG_TYPE> mp,
                         java.lang.String ip,
                         int port)

Connect to the server at the specified address and port.

Parameters:

ip - the IP where the server lives

port - the port the server listens on

Method Detail

run

public void run()

The BackendConnection thread will connect to the server and then continuously read from the socket and pass on received messages to the protocol handler. It will automatically try to reconnect if disconnected or if it fails to get connected.

Specified by:

run in interface java.lang.Runnable

Overrides:

run in class java.lang.Thread

shutdown

public void shutdown()

tells the connection to shut down as soon as possible

isShutdown

public boolean isShutdown()

gets whether the connection has been shutdown yet

isConnected

public boolean isConnected()

returns true if the connection to the server is currently alive

reconnect

public void reconnect()

tells the connection to disconnect and then connect again

sendMessage

public void sendMessage(OFGMessage m)
                 throws java.io.IOException

Tries to send a message and sets the transaction ID of the message to the next available transaction ID. If m is a POLL_REQUEST message, then the internal message's transaction ID is also set.

Throws:

java.io.IOException

popAssociatedStatefulRequest

public OFGMessage popAssociatedStatefulRequest(int xid)

Returns the request sent with the specified transaction ID, if any. The stateful request returned will no longer be remembered.

scrubExpiredStatefulRequests

protected void scrubExpiredStatefulRequests()

Remove cached stateful requests which have been cached for longer than getRequestLifetime()