edu.umass.cs.protocoltask.examples.pingpong

Class PingPongProtocolTask

java.lang.Object

edu.umass.cs.protocoltask.examples.PingPongServer

edu.umass.cs.protocoltask.examples.pingpong.PingPongProtocolTask

All Implemented Interfaces:

ProtocolTask<java.lang.Integer,PingPongPacket.PacketType,java.lang.String>, Keyable<java.lang.String>

public class PingPongProtocolTask
extends PingPongServer

Author:

V. Arun

This example waits for numPings ping-pongs form any node in a specified set of nodes. Note that it does not wait for numPings ping-pongs from *all* nodes in the set.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_PINGS Max number of pings in PingPong example.

Fields inherited from class edu.umass.cs.protocoltask.examples.PingPongServer

myID

Constructor Summary

Constructors

Constructor and Description
PingPongProtocolTask(int id, java.util.Set<java.lang.Integer> nodes, int numPings)

Method Summary

Modifier and Type	Method and Description
java.lang.String	getKey() Start of overridden methods
MessagingTask[]	handleEvent(ProtocolEvent<PingPongPacket.PacketType,java.lang.String> event, ProtocolTask<java.lang.Integer,PingPongPacket.PacketType,java.lang.String>[] ptasks) The action handling the event may return messaging tasks that will be automatically handled by this interface.
java.lang.String	refreshKey()
MessagingTask[]	start() Actions executed in the beginning.

Methods inherited from class edu.umass.cs.protocoltask.examples.PingPongServer

getEventTypes

Methods inherited from class java.lang.Object

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

Field Detail

MAX_PINGS

public static final int MAX_PINGS

Max number of pings in PingPong example.

See Also:

Constant Field Values

Constructor Detail

PingPongProtocolTask

public PingPongProtocolTask(int id,
                            java.util.Set<java.lang.Integer> nodes,
                            int numPings)

Parameters:

id -

nodes -

numPings -

Method Detail

getKey

public java.lang.String getKey()

Start of overridden methods

Specified by:

getKey in interface Keyable<java.lang.String>

Overrides:

getKey in class PingPongServer

Returns:

The key.

refreshKey

public java.lang.String refreshKey()

Overrides:

refreshKey in class PingPongServer

handleEvent

public MessagingTask[] handleEvent(ProtocolEvent<PingPongPacket.PacketType,java.lang.String> event,
                                   ProtocolTask<java.lang.Integer,PingPongPacket.PacketType,java.lang.String>[] ptasks)

Description copied from interface: ProtocolTask

The action handling the event may return messaging tasks that will be automatically handled by this interface. This interface lets the protocol developer focus on event/action pairs without worrying about networking or scheduling optimizations. The parameter ptasks[0] returns a single protocol task if any spawned by this action. We need a unique key ***that is unique across all nodes*** in order to match incoming messages against the corresponding task. ProtocolExecutor automatically inserts this key in every message exchanged as part of the protocol task. The getKey method is necessitated by the Keyable interface in this class. A simple way to choose a String key that is unique across all nodes at a node is to use the current node's ID concatenated with a random number and/or the current time. A protocol task can also explicitly choose meaningful (i.e., not random or based on timestamps) names for tasks, but they still need to be unique across all nodes. Refer to the examples provided with the protocoltask package. A protocol task can be canceled from within the task, if necessary, by invoking ProtocolExecutor.cancel(this). But you probably have a bad design if you need to rely on this.

Specified by:

handleEvent in interface ProtocolTask<java.lang.Integer,PingPongPacket.PacketType,java.lang.String>

Overrides:

handleEvent in class PingPongServer

Returns:

Returns messaging tasks to be performed.

start

public MessagingTask[] start()

Description copied from interface: ProtocolTask

Actions executed in the beginning.

Specified by:

start in interface ProtocolTask<java.lang.Integer,PingPongPacket.PacketType,java.lang.String>

Overrides:

start in class PingPongServer

Returns:

Initial messaging task.