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unison/src/traffic-control/model/red-queue-disc.h
2016-03-08 22:00:35 -08:00

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright © 2011 Marcos Talau
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Marcos Talau (talau@users.sourceforge.net)
*
* Thanks to: Duy Nguyen<duy@soe.ucsc.edu> by RED efforts in NS3
*
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright (c) 1990-1997 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* PORT NOTE: This code was ported from ns-2 (queue/red.h). Almost all
* comments also been ported from NS-2.
* This implementation aims to be close to the results cited in [0]
* [0] S.Floyd, K.Fall http://icir.org/floyd/papers/redsims.ps
*/
#ifndef RED_QUEUE_DISC_H
#define RED_QUEUE_DISC_H
#include "ns3/packet.h"
#include "ns3/queue-disc.h"
#include "ns3/nstime.h"
#include "ns3/boolean.h"
#include "ns3/data-rate.h"
#include "ns3/nstime.h"
#include "ns3/random-variable-stream.h"
namespace ns3 {
class TraceContainer;
/**
* \ingroup traffic-control
*
* \brief A RED packet queue disc
*/
class RedQueueDisc : public QueueDisc
{
public:
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
/**
* \brief RedQueueDisc Constructor
*
* Create a RED queue disc
*/
RedQueueDisc ();
/**
* \brief Destructor
*
* Destructor
*/
virtual ~RedQueueDisc ();
/**
* \brief Stats
*/
typedef struct
{
uint32_t unforcedDrop; //!< Early probability drops
uint32_t forcedDrop; //!< Forced drops, qavg > max threshold
uint32_t qLimDrop; //!< Drops due to queue limits
} Stats;
/**
* \brief Drop types
*/
enum
{
DTYPE_NONE, //!< Ok, no drop
DTYPE_FORCED, //!< A "forced" drop
DTYPE_UNFORCED, //!< An "unforced" (random) drop
};
/**
* \brief Set the operating mode of this queue.
* Set operating mode
*
* \param mode The operating mode of this queue.
*/
void SetMode (Queue::QueueMode mode);
/**
* \brief Get the encapsulation mode of this queue.
* Get the encapsulation mode of this queue
*
* \returns The encapsulation mode of this queue.
*/
Queue::QueueMode GetMode (void);
/**
* \brief Get the current value of the queue in bytes or packets.
*
* \returns The queue size in bytes or packets.
*/
uint32_t GetQueueSize (void);
/**
* \brief Set the alpha value to adapt m_curMaxP.
*
* \param alpha The value of alpha to adapt m_curMaxP.
*/
void SetAredAlpha (double alpha);
/**
* \brief Get the alpha value to adapt m_curMaxP.
*
* \returns The alpha value to adapt m_curMaxP.
*/
double GetAredAlpha (void);
/**
* \brief Set the beta value to adapt m_curMaxP.
*
* \param beta The value of beta to adapt m_curMaxP.
*/
void SetAredBeta (double beta);
/**
* \brief Get the beta value to adapt m_curMaxP.
*
* \returns The beta value to adapt m_curMaxP.
*/
double GetAredBeta (void);
/**
* \brief Set the limit of the queue.
*
* \param lim The limit in bytes or packets.
*/
void SetQueueLimit (uint32_t lim);
/**
* \brief Set the thresh limits of RED.
*
* \param minTh Minimum thresh in bytes or packets.
* \param maxTh Maximum thresh in bytes or packets.
*/
void SetTh (double minTh, double maxTh);
/**
* \brief Get the RED statistics after running.
*
* \returns The drop statistics.
*/
Stats GetStats ();
/**
* Assign a fixed random variable stream number to the random variables
* used by this model. Return the number of streams (possibly zero) that
* have been assigned.
*
* \param stream first stream index to use
* \return the number of stream indices assigned by this model
*/
int64_t AssignStreams (int64_t stream);
protected:
/**
* \brief Dispose of the object
*/
virtual void DoDispose (void);
private:
virtual bool DoEnqueue (Ptr<QueueDiscItem> item);
virtual Ptr<QueueDiscItem> DoDequeue (void);
virtual Ptr<const QueueDiscItem> DoPeek (void) const;
virtual bool CheckConfig (void);
/**
* \brief Initialize the queue parameters.
*
* Note: if the link bandwidth changes in the course of the
* simulation, the bandwidth-dependent RED parameters do not change.
* This should be fixed, but it would require some extra parameters,
* and didn't seem worth the trouble...
*/
virtual void InitializeParams (void);
/**
* \brief Compute the average queue size
* \param nQueued number of queued packets
* \param m simulated number of packets arrival during idle period
* \param qAvg average queue size
* \param qW queue weight given to cur q size sample
* \returns new average queue size
*/
double Estimator (uint32_t nQueued, uint32_t m, double qAvg, double qW);
/**
* \brief Update m_curMaxP
* \param newAve new average queue length
* \param now Current Time
*/
void UpdateMaxP (double newAve, Time now);
/**
* \brief Check if a packet needs to be dropped due to probability mark
* \param item queue item
* \param qSize queue size
* \returns 0 for no drop/mark, 1 for drop
*/
uint32_t DropEarly (Ptr<QueueDiscItem> item, uint32_t qSize);
/**
* \brief Returns a probability using these function parameters for the DropEarly function
* \param qAvg Average queue length
* \param maxTh Max avg length threshold
* \param gentle "gentle" algorithm
* \param vA vA
* \param vB vB
* \param vC vC
* \param vD vD
* \param maxP max_p
* \returns Prob. of packet drop before "count"
*/
double CalculatePNew (double qAvg, double , bool gentle, double vA,
double vB, double vC, double vD, double maxP);
/**
* \brief Returns a probability using these function parameters for the DropEarly function
* \param p Prob. of packet drop before "count"
* \param count number of packets since last random number generation
* \param countBytes number of bytes since last drop
* \param meanPktSize Avg pkt size
* \param wait True for waiting between dropped packets
* \param size packet size
* \returns Prob. of packet drop
*/
double ModifyP (double p, uint32_t count, uint32_t countBytes,
uint32_t meanPktSize, bool wait, uint32_t size);
Stats m_stats; //!< RED statistics
// ** Variables supplied by user
Queue::QueueMode m_mode; //!< Mode (Bytes or packets)
uint32_t m_meanPktSize; //!< Avg pkt size
uint32_t m_idlePktSize; //!< Avg pkt size used during idle times
bool m_isWait; //!< True for waiting between dropped packets
bool m_isGentle; //!< True to increases dropping prob. slowly when ave queue exceeds maxthresh
bool m_isARED; //!< True to enable Adaptive RED
bool m_isAdaptMaxP; //!< True to adapt m_curMaxP
double m_minTh; //!< Min avg length threshold (bytes)
double m_maxTh; //!< Max avg length threshold (bytes), should be >= 2*minTh
uint32_t m_queueLimit; //!< Queue limit in bytes / packets
double m_qW; //!< Queue weight given to cur queue size sample
double m_lInterm; //!< The max probability of dropping a packet
Time m_targetDelay; //!< Target average queuing delay in ARED
Time m_interval; //!< Time interval to update m_curMaxP
double m_top; //!< Upper bound for m_curMaxP in ARED
double m_bottom; //!< Lower bound for m_curMaxP in ARED
double m_alpha; //!< Increment parameter for m_curMaxP in ARED
double m_beta; //!< Decrement parameter for m_curMaxP in ARED
Time m_rtt; //!< Rtt to be considered while automatically setting m_bottom in ARED
bool m_isNs1Compat; //!< Ns-1 compatibility
DataRate m_linkBandwidth; //!< Link bandwidth
Time m_linkDelay; //!< Link delay
// ** Variables maintained by RED
double m_vProb1; //!< Prob. of packet drop before "count"
double m_vA; //!< 1.0 / (m_maxTh - m_minTh)
double m_vB; //!< -m_minTh / (m_maxTh - m_minTh)
double m_vC; //!< (1.0 - m_curMaxP) / m_maxTh - used in "gentle" mode
double m_vD; //!< 2.0 * m_curMaxP - 1.0 - used in "gentle" mode
double m_curMaxP; //!< Current max_p
Time m_lastSet; //!< Last time m_curMaxP was updated
double m_vProb; //!< Prob. of packet drop
uint32_t m_countBytes; //!< Number of bytes since last drop
uint32_t m_old; //!< 0 when average queue first exceeds threshold
uint32_t m_idle; //!< 0/1 idle status
double m_ptc; //!< packet time constant in packets/second
double m_qAvg; //!< Average queue length
uint32_t m_count; //!< Number of packets since last random number generation
/**
* 0 for default RED
* 1 experimental (see red-queue.cc)
* 2 experimental (see red-queue.cc)
* 3 use Idle packet size in the ptc
*/
uint32_t m_cautious;
Time m_idleTime; //!< Start of current idle period
Ptr<UniformRandomVariable> m_uv; //!< rng stream
};
}; // namespace ns3
#endif // RED_QUEUE_DISC_H