gridsim.net.fnb
Class FIFO

Object
  Thread
      Sim_entity
          FnbSCFQScheduler
              FIFO

All Implemented Interfaces:

PacketScheduler, Cloneable, Runnable

public class FIFO
extends FnbSCFQScheduler

This class implements the FIFO policy for the management of network buffers at routers. Its basic functionality is as follows:

• There is a FIFO object at each outport in routers.
• For each incoming packet that reaches that outport port, the policy decides whether it is enqueued or dropped. This is done by calculating the average buffer size and comparing it with two thresholds.
• If the packet is dropped, and it is not a junk packet, we must inform the user involved in the transmission about the dropping.

For more details, please refer to A. Caminero, A. Sulistio, B. Caminero, C. Carrion, and R. Buyya, Simulation of Buffer Management Policies in Networks for Grids, Proceedings of the 41th Annual Simulation Symposium (ANSS-41, IEEE CS Press, Los Alamitos, CA, USA), April 14-16, 2008, Ottawa, Canada.

Since:

GridSim Toolkit 4.2

Author:

Agustin Caminero

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

FIFO(String name, double baudRate, int max_buf_size, double queue_weight, boolean stats)
Creates a new FIFO policy with the specified name and baud rate (in bits/sec).

Method Summary

double	avgQueueSize() Calculate the avg queue size for the FIFO algorithm.
boolean	enque(Packet pnp) Checks queue size and puts a packet into the queue
double	getAvg() Returns the avg buffer size
protected void	initialize() This function initializes the parameters of FIFO policy
boolean	setBaudRate(double rate) Sets the baud rate that this scheduler will be sending packets at.
void	updateStats() Update the statistics of this scheduler to a file.

Methods inherited from class FnbSCFQScheduler

body, checkDroppedGlList, deque, getBaudRate, getCounterDroppedPkts, getMaxBufferSize, getMaxBufferSizeInPkts, getRouterID, getSchedID, getSchedName, increaseDroppedPktCounter, insertGlID_userID, insertPacketIntoQueue, isEmpty, makeRoomForPacket, pktListSize, resetCounterDroppedPkts, setBaudRateSCFQ, setMaxBufferSize, setRouterID, setWeights, size

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

FIFO

public FIFO(String name,
            double baudRate,
            int max_buf_size,
            double queue_weight,
            boolean stats)
     throws Exception

Creates a new FIFO policy with the specified name and baud rate (in bits/sec). The name can be useful for debugging purposes, but serves no functional purposes.

Parameters:

name - Name of this scheduler

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

max_buf_size - maximum buffer size for routers

queue_weight - this parameter reflects how important is the last

stats - whether we want to store stats or not

Throws:

Exception - This happens when the name is null or the baud rate <= 0

Pre Condition:

name != null, baudRate > 0

Post Condition:

$none

Method Detail

enque

public boolean enque(Packet pnp)

Checks queue size and puts a packet into the queue

Specified by:

enque in interface PacketScheduler

Specified by:

enque in class FnbSCFQScheduler

Parameters:

pnp - A Packet to be enqued by this scheduler.

Returns:

true if enqued, false otherwise

Pre Condition:

pnp != null

Post Condition:

$none

avgQueueSize

public double avgQueueSize()

Calculate the avg queue size for the FIFO algorithm.

Returns:

the average queue size of this queue, which has been calculated in this function

initialize

protected void initialize()

This function initializes the parameters of FIFO policy

Specified by:

initialize in class FnbSCFQScheduler

setBaudRate

public boolean setBaudRate(double rate)

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

Parameters:

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

Returns:

true if the baud rate has been set properly

Pre Condition:

rate > 0

Post Condition:

$none

getAvg

public double getAvg()

Returns the avg buffer size

Specified by:

getAvg in class FnbSCFQScheduler

Returns:

the average queue size, which was already calculated

updateStats

public void updateStats()

Update the statistics of this scheduler to a file.
The file name is schedulerName_Buffers.csv.
The format is "Clock, MAX_P, MIN_TH, MAX_TH, AVG, QUEUE_SIZE".
Note that for the FIFO, MAX_P, MIN_TH, and MAX_TH values are empty.

Specified by:

updateStats in class FnbSCFQScheduler