Class DVNode

java.lang.Object
  Node
      DVNode

public class DVNode
extends Node

Distance Vector algorithm implementing node. If you want to tune the DV algorithm, this is the place.

Field Summary

Fields inherited from class Node

failed, lastHeardDelay, lastUpdatedSlot, neighbor, rand, uid

Constructor Summary

DVNode()

Method Summary

protected void	failureEvent() This method is invoked (by Node.java) when a previously running node goes down.
protected void	neighborFailureEvent(Node neighbor) Invoked when a timeout indicates that a neighbor node has failed.
protected void	processUpdate(UpdatePacket udp) Called for each update packet in this node's queue when it is selected to run during a time step.
protected void	recoveryEvent() This method is invoked (by Node.java) when a previously failed node comes back online.
protected void	startUpdate() When this node is selected to run during a time step, the "driver" code in Node.java: first calls this routine (startUpdate()) then with high, but not certain, probability calls processUpdate() for each update packet in the node's queue
protected void	stopUpdate() See comment before startUpdate().

Methods inherited from class Node

getRoutingTable, getUID, hasFailed, oracleComputeRoutingTable, oracleFillTable, sendUpdatePacket, setHasFailed, setupNeighborInformation, swapInQueues, takeStep, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

DVNode

public DVNode()

Method Detail

startUpdate

protected void startUpdate()

When this node is selected to run during a time step, the "driver" code in Node.java:

1. first calls this routine (startUpdate())
2. then with high, but not certain, probability calls processUpdate() for each update packet in the node's queue
3. (1) and (3) allow some flexibility in the implementation of different (sub)classes of node, without having to meddle with the code in Node.java.

   Specified by:

   startUpdate in class Node

processUpdate

protected void processUpdate(UpdatePacket udp)

Called for each update packet in this node's queue when it is selected to run during a time step.

Specified by:

processUpdate in class Node

stopUpdate

protected void stopUpdate()

See comment before startUpdate().

Specified by:

stopUpdate in class Node

failureEvent

protected void failureEvent()

This method is invoked (by Node.java) when a previously running node goes down.

You are honor bound to throw away any information your node may have cached when this happens. (Node.java will have already thrown out what it knows about, i.e., the routing table.)

Specified by:

failureEvent in class Node

recoveryEvent

protected void recoveryEvent()

This method is invoked (by Node.java) when a previously failed node comes back online. When the node failed, Node.java assigned it a new RoutingTable object, with the entries for all destinations set to "no next hop". You can/must do here anything you think is necessary.

Because the base implementation depends on the logging done by the RouterTable object, we must force all "no path to the destination" entries into it. We do that here. (Note that RouterTable.startLogging() has already been called (by startUpdate()) when control reaches this point.)

Node.java sets the routing table entry for this node to itself correctly when you return from this method.

Specified by:

recoveryEvent in class Node

neighborFailureEvent

protected void neighborFailureEvent(Node neighbor)

Invoked when a timeout indicates that a neighbor node has failed.

Specified by:

neighborFailureEvent in class Node