gridsim.net
Class RateControlledScheduler

Object
  Thread
      Sim_entity
          RateControlledScheduler

All Implemented Interfaces:

PacketScheduler, Cloneable, Runnable

public class RateControlledScheduler
extends Sim_entity
implements PacketScheduler

RateControlledScheduler is an implementation of a rate-jitter controlling regulator. For more details refer to H. Zhang and D.Ferrari's INFOCOM '93 paper Rate-Controlled Static-Priority Queueing.

RateControlledScheduler can be used to control the bandwidth that is assigned to each class of user at a Router. This is a non-work conserving algorithm, which means that the router can remain idle even if there are packets in its queue.

At a RateControlledScheduler each class of users is assigned a certain percentage of bandwidth, and the scheduler makes sure that each class remains constrained within its bandwidth limits at all times.

Since:

GridSim Toolkit 4.0

Author:

Gokul Poduval & Chen-Khong Tham, National University of Singapore

Invariant:

$none

Nested Class Summary

Nested classes/interfaces inherited from class Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

RateControlledScheduler(String name, double baudRate, int numClasses)
Creates a new RateControlled packet scheduler with the specified name and baud rate (in bits/s).

RateControlledScheduler(String name, double baudRate, int routerID, int numClasses)
Creates a new RateControlled packet scheduler with the specified name and baud rate (in bits/s).

RateControlledScheduler(String name, int numClasses)
Creates a new RateControlled packet scheduler with the specified name.

Method Summary

void	body() Handles an incoming events coming from a specified Router
Packet	deque() The method deque() has to decide which queue is to be served next -- This method is not used
boolean	enque(Packet np) Puts a packet into the queue -- This method is not used
double	getBaudRate() Returns the baud rate of the egress port that is using this scheduler.
int	getNumClass() Gets the number of classes for prioritizing incoming packets
double[]	getRate() Gets the list of rates for each packet class
int	getRouterID() Gets the router ID that hosts this scheduler.
int	getSchedID() Gets the ID of this scheduler.
String	getSchedName() Gets the name of this scheduler.
boolean	isEmpty() Determines whether the scheduler is currently keeping any packets in its queue(s).
boolean	setBaudRate(double rate) Sets the baud rate that this scheduler will be sending packets at.
boolean	setRates(double[] rates) This method allows you to set different rates for different types of traffic.
boolean	setRouterID(int routerID) Sets the router ID that hosts this scheduler.
int	size() Determines the number of packets that are currently enqueued in this scheduler.

Methods inherited from class Sim_entity

add_generator, add_param, add_port, clone, get_id, get_name, get_port, get_port, get_stat, run, send_on, set_invisible, set_stat, sim_cancel, sim_completed, sim_current, sim_get_next, sim_get_next, sim_hold_for, sim_hold, sim_pause_for, sim_pause_for, sim_pause_until, sim_pause_until, sim_pause, sim_process_for, sim_process_for, sim_process_until, sim_process_until, sim_process, sim_putback, sim_schedule, sim_schedule, sim_schedule, sim_schedule, sim_schedule, sim_schedule, sim_select, sim_trace, sim_wait_for, sim_wait_for, sim_wait_for, sim_wait, sim_waiting, sim_waiting

Methods inherited from class 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 Object

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

Constructor Detail

RateControlledScheduler

public RateControlledScheduler(String name,
                               double baudRate,
                               int numClasses)
                        throws ParameterException

Creates a new RateControlled packet scheduler with the specified name and baud rate (in bits/s). The name can be useful for debugging purposes, but serves no functional purposes. Don't forget to set the rate for each packet class by using the setRates(double[]) method.

Parameters:

name - Name of this scheduler

baudRate - baud rate in bits/s of the port that is using this scheduler.

numClasses - number of classes for prioritizing a packet

Throws:

ParameterException - This happens when the name is null or the baud rate <= 0 or num of classes <= 0

Pre Condition:

name != null, baudRate > 0, numClasses > 0

Post Condition:

$none

RateControlledScheduler

public RateControlledScheduler(String name,
                               int numClasses)
                        throws ParameterException

Creates a new RateControlled packet scheduler with the specified name. The baud rate is left at 0, and should be set with PacketScheduler.setBaudRate(double) before the simulation starts. The name can be useful for debugging purposes, but serves no functional purposes. Don't forget to set the rate for each packet class by using the setRates(double[]) method.

Parameters:

name - Name of this scheduler

numClasses - number of classes for prioritizing a packet

Throws:

ParameterException - This happens when the name is null or the baud rate <= 0 or num of classes <= 0

Pre Condition:

name != null, numClasses > 0

Post Condition:

$none

RateControlledScheduler

public RateControlledScheduler(String name,
                               double baudRate,
                               int routerID,
                               int numClasses)
                        throws ParameterException

Creates a new RateControlled packet scheduler with the specified name and baud rate (in bits/s). The name can be useful for debugging purposes, but serves no functional purposes. Don't forget to set the rate for each packet class by using the setRates(double[]) method.

Parameters:

name - Name of this scheduler

baudRate - baud rate in bits/s of the port that is using this scheduler.

routerID - the router ID that hosts this packet scheduler

numClasses - number of classes for prioritizing a packet

Throws:

ParameterException - This happens when the name is null or router ID <= 0 or the baud rate <= 0 or num of classes <= 0

Pre Condition:

name != null, baudRate > 0, routerID > 0, numClasses > 0

Post Condition:

$none

Method Detail

getNumClass

public int getNumClass()

Gets the number of classes for prioritizing incoming packets

Returns:

number of classes

Pre Condition:

$none

Post Condition:

$none

getRate

public double[] getRate()

Gets the list of rates for each packet class

Returns:

the list of rates or null if empty

Pre Condition:

$none

Post Condition:

$none

body

public void body()

Handles an incoming events coming from a specified Router

Overrides:

body in class Sim_entity

Pre Condition:

$none

Post Condition:

$none

setRates

public boolean setRates(double[] rates)

This method allows you to set different rates for different types of traffic. Traffic of class n are assigned a rate of rates[n]. The higher the rate of a class, the better the service it receives. NOTE: Each rate must be a positive number.

Parameters:

rates - a linear array of the rates to be assigned to different classes of traffic.

Pre Condition:

rates != null

Post Condition:

$none

isEmpty

public boolean isEmpty()

Determines whether the scheduler is currently keeping any packets in its queue(s).

Specified by:

isEmpty in interface PacketScheduler

Returns:

true if no packets are enqueued, false otherwise

Pre Condition:

$none

Post Condition:

$none

size

public int size()

Determines the number of packets that are currently enqueued in this scheduler.

Specified by:

size in interface PacketScheduler

Returns:

the number of packets enqueud by this scheduler.

Pre Condition:

$none

Post Condition:

$none

getBaudRate

public double getBaudRate()

Returns the baud rate of the egress port that is using this scheduler. If the baud rate is zero, it means you haven't set it up.

Specified by:

getBaudRate in interface PacketScheduler

Returns:

the baud rate in bits/s

See Also:

PacketScheduler.setBaudRate(double)

Pre Condition:

$none

Post Condition:

$result >= 0

setBaudRate

public boolean setBaudRate(double rate)

Sets the baud rate that this scheduler will be sending packets at.

Specified by:

setBaudRate in interface PacketScheduler

Parameters:

rate - the baud rate of this scheduler (in bits/s)

Pre Condition:

rate > 0

Post Condition:

$none

getSchedName

public String getSchedName()

Gets the name of this scheduler.

Specified by:

getSchedName in interface PacketScheduler

Returns:

the name of this scheduler

Pre Condition:

$none

Post Condition:

$none

getSchedID

public int getSchedID()

Gets the ID of this scheduler.

Specified by:

getSchedID in interface PacketScheduler

Returns:

the ID of this scheduler or -1 if no ID is found

Pre Condition:

$none

Post Condition:

$none

setRouterID

public boolean setRouterID(int routerID)

Sets the router ID that hosts this scheduler.

Specified by:

setRouterID in interface PacketScheduler

Parameters:

routerID - the router ID that hosts this scheduler

Returns:

true if successful or false otherwise

Pre Condition:

routerID > 0

Post Condition:

$none

getRouterID

public int getRouterID()

Gets the router ID that hosts this scheduler.

Specified by:

getRouterID in interface PacketScheduler

Returns:

the router ID or -1 if no ID is found

Pre Condition:

$none

Post Condition:

$none

enque

public boolean enque(Packet np)

Puts a packet into the queue -- This method is not used

Specified by:

enque in interface PacketScheduler

Parameters:

np - A Packet to be enqued by this scheduler.

Returns:

true if enqued, false otherwise

Pre Condition:

pnp != null

Post Condition:

$none

deque

public Packet deque()

The method deque() has to decide which queue is to be served next -- This method is not used

Specified by:

deque in interface PacketScheduler

Returns:

the packet to be sent out or null if empty

Pre Condition:

$none

Post Condition:

$none