pie-queue-disc.h

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/*
 * Copyright (c) 2016 NITK Surathkal
 *
 * 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
 *
 * Authors: Shravya Ks <shravya.ks0@gmail.com>
 *          Smriti Murali <m.smriti.95@gmail.com>
 *          Mohit P. Tahiliani <tahiliani@nitk.edu.in>
 */
 
/*
 * PORT NOTE: This code was ported from ns-2.36rc1 (queue/pie.h).
 * Most of the comments are also ported from the same.
 */
 
#ifndef PIE_QUEUE_DISC_H
#define PIE_QUEUE_DISC_H
 
#include "ns3/boolean.h"
#include "ns3/data-rate.h"
#include "ns3/event-id.h"
#include "ns3/nstime.h"
#include "ns3/queue-disc.h"
#include "ns3/random-variable-stream.h"
#include "ns3/timer.h"
 
#define BURST_RESET_TIMEOUT 1.5
 
class PieQueueDiscTestCase; // Forward declaration for unit test
 
namespace ns3
{
 
class TraceContainer;
class UniformRandomVariable;
 
class PieQueueDisc : public QueueDisc
{
  public:
    static TypeId GetTypeId();
 
    PieQueueDisc();
 
    ~PieQueueDisc() override;
 
    enum BurstStateT
    {
        NO_BURST,
        IN_BURST,
        IN_BURST_PROTECTING,
    };
 
    Time GetQueueDelay();
    int64_t AssignStreams(int64_t stream);
 
    // Reasons for dropping packets
    static constexpr const char* UNFORCED_DROP =
        "Unforced drop"; 
    static constexpr const char* FORCED_DROP =
        "Forced drop"; 
    static constexpr const char* UNFORCED_MARK =
        "Unforced mark"; 
    static constexpr const char* CE_THRESHOLD_EXCEEDED_MARK =
        "CE threshold exceeded mark"; 
 
  protected:
    void DoDispose() override;
 
  private:
    friend class ::PieQueueDiscTestCase; // Test code
    bool DoEnqueue(Ptr<QueueDiscItem> item) override;
    Ptr<QueueDiscItem> DoDequeue() override;
    bool CheckConfig() override;
 
    void InitializeParams() override;
 
    bool DropEarly(Ptr<QueueDiscItem> item, uint32_t qSize);
 
    void CalculateP();
 
    static const uint64_t DQCOUNT_INVALID =
        std::numeric_limits<uint64_t>::max(); 
 
    // ** Variables supplied by user
    Time m_sUpdate;            
    Time m_tUpdate;            
    Time m_qDelayRef;          
    uint32_t m_meanPktSize;    
    Time m_maxBurst;           
    double m_a;                
    double m_b;                
    uint32_t m_dqThreshold;    
    bool m_useDqRateEstimator; 
    bool
        m_isCapDropAdjustment; 
    bool m_useEcn;             
    bool m_useDerandomization; 
    double m_markEcnTh;        
    Time m_activeThreshold;    
    Time m_ceThreshold;        
    bool m_useL4s;             
 
    // ** Variables maintained by PIE
    double m_dropProb;        
    Time m_qDelayOld;         
    Time m_qDelay;            
    Time m_burstAllowance;    
    uint32_t m_burstReset;    
    BurstStateT m_burstState; 
    bool m_inMeasurement;     
    double m_avgDqRate;       
    Time m_dqStart;           
    uint64_t m_dqCount;       
    EventId m_rtrsEvent;      
    Ptr<UniformRandomVariable> m_uv; 
    double m_accuProb;               
    bool m_active;                   
};
 
}; // namespace ns3
 
#endif