CSE 588, Interface to Simulator

Interface to Simulator

Debug

public static void Enable (char type);
Enable debug messages of a particular kind specified by type.
public static void Disable (char type);
Disable debug messages of a particular kind.
public static void SetEnabled (String types);
Enable debug messages of all types specified in the string.
public static boolean IsEnabled (char type);
Check if debug messages of a particular type are enabled.
public static void println (char type, String s);
Print a debug message s if messages of the specified type are enabled.

Timer

The Timer is accessed using Timer.global which is a static field inside the class Timer.
All client classes should extend the class TimerClient. This identifies them as clients and gives them access to monitor routines that work correctly with the timer. This also means that they have to define the Timeout method which is called by the timer when a timeout occurs.

The timer provides the following functionality:

public void CurrentSimTime ()
Return the current simulation time. Therefore, using Timer.global.CurrentSimTime() in your program would give you the current simulation time.
public TimeoutID SetTimeout (TimerClient client, long time, TimeUnit units, Object info)
Sets a timeout for the client at the specified time and associates info with the timeout. When the timeout actually occurs, the Timeout method defined by the client is called with the info parameter. Extending the TimerClient class forces the client to define the Timeoutmethod. An ID for the timeout is returned so that it can be later cancelled.
public void CancelTimeout (TimeoutID)
Cancels the timeout specified by the ID.
public void WaitUntil (TimerClient, long, TimeUnit)
Makes the client wait till the specified time. The client is resumed when the simulation time reaches the time specified by the client.
public void WaitFor (TimerClient, long, TimeUnit)
Similar to WaitUntil except that the client specified the time to wait for.

When a client extends the TimerClient class, it is provided the following functionality:

public void Timeout (Object info)
A prototype for the Timeout method that the client is expected to overwrite. This method is called by the timer when a timeout set by the client occurs.
public void Wait ()
When the client wants to wait for an event, it can use the Wait method defined in TimerClient. The Wait method is very similar to the wait() defined in Object class - it waits until someone does a Notify. However, clients are forbidden from using the wait method because it can leads to a deadlock when it interacts with our timer system.
public void Notify ()
Used to notify a client which is waiting. Similar to notify() which should never be used.

Network

The Network class provides the ability to send packets on the network. It provides the following method for sending packets:

public void TransmitPacket (NetworkPacket p);
Submit a packet to the network, for delivery to the client whose address is in the destinationAddr field of the packet. Blocks for whatever transmission time the network imposes.

In order to receive a packet, the client has to implement the interface PacketReceiver. This entails that the client has to define the following method.

public void PacketArrived (NetworkPacket p);
When a packet arrives from the network for the client, the above method is called. The client can do the processing of the packet in the PacketArrived method.

Reliability

The reliability package defines the interfaces ReliableSender and ReliableReceiver. Your implementations of the sliding window protocol should implement these interfaces.

Application

The application package provides an implementation of two application = one of which continuously sends data and the other receives data. You can use these applications without changing them.

project1

The project1 package sets up the network with the appropriate parameters.

The major part of the project would involve changing the provided stop-and-wait protocol implementation to the sliding window protocol application. For this you would mainly have to modify the files SAWSender.java and SAWReceiver.java.