cobalt-queue-disc.h

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2019 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
 *
 * Cobalt, the CoDel - BLUE - Alternate Queueing discipline
 * Based on linux code.
 *
 * Ported to ns-3 by: Vignesh Kannan <vignesh2496@gmail.com>
 *                    Harsh Lara <harshapplefan@gmail.com>
 *                    Jendaipou Palmei <jendaipoupalmei@gmail.com>
 *                    Shefali Gupta <shefaligups11@gmail.com>
 *                    Mohit P. Tahiliani <tahiliani@nitk.edu.in>
 *
 */
 
#ifndef COBALT_H
#define COBALT_H
 
#include "ns3/queue-disc.h"
#include "ns3/nstime.h"
#include "ns3/boolean.h"
#include "ns3/data-rate.h"
#include "ns3/simulator.h"
#include "ns3/string.h"
#include "ns3/traced-value.h"
#include "ns3/random-variable-stream.h"
#include "ns3/trace-source-accessor.h"
 
namespace ns3 {
 
#define REC_INV_SQRT_CACHE (16)
#define DEFAULT_COBALT_LIMIT 1000
 
class TraceContainer;
 
class CobaltQueueDisc : public QueueDisc
{
public:
  static TypeId GetTypeId (void);
 
  CobaltQueueDisc ();
 
  virtual ~CobaltQueueDisc ();
 
  Time GetTarget (void) const;
 
  Time GetInterval (void) const;
 
  int64_t GetDropNext (void) const;
 
  static constexpr const char* TARGET_EXCEEDED_DROP = "Target exceeded drop";  
  static constexpr const char* OVERLIMIT_DROP = "Overlimit drop";  
  static constexpr const char* FORCED_MARK = "forcedMark";  
  static constexpr const char* CE_THRESHOLD_EXCEEDED_MARK = "CE threshold exceeded mark";  
 
  double GetPdrop () const;
 
  int64_t AssignStreams (int64_t stream);
 
  int64_t Time2CoDel (Time t) const;
 
protected:
  virtual void DoDispose (void);
 
private:
  virtual bool DoEnqueue (Ptr<QueueDiscItem> item);
  virtual Ptr<QueueDiscItem> DoDequeue (void);
  virtual Ptr<const QueueDiscItem> DoPeek (void);
  virtual bool CheckConfig (void);
 
  virtual void InitializeParams (void);
 
  void NewtonStep (void);
 
  int64_t ControlLaw (int64_t t);
 
  void InvSqrt (void);
 
  void CacheInit (void);
 
  bool CoDelTimeAfter (int64_t a, int64_t b);
 
  bool CoDelTimeAfterEq (int64_t a, int64_t b);
 
  void CobaltQueueFull (int64_t now);
 
  void CobaltQueueEmpty (int64_t now);
 
  bool CobaltShouldDrop (Ptr<QueueDiscItem> item, int64_t now);
 
  // Common to CoDel and Blue
  // Maintained by Cobalt
  Stats m_stats;                          
 
  // Codel parameters
  // Maintained by Cobalt
  TracedValue<uint32_t> m_count;          
  TracedValue<int64_t> m_dropNext;       
  TracedValue<bool> m_dropping;           
  uint32_t m_recInvSqrt;                  
  uint32_t m_recInvSqrtCache[REC_INV_SQRT_CACHE] = {0};   
 
  // Supplied by user
  Time m_interval;                        
  Time m_target;                          
  bool m_useEcn;                          
  Time m_ceThreshold;                     
  bool m_useL4s;                          
  Time m_blueThreshold;                   
 
  // Blue parameters
  // Maintained by Cobalt
  Ptr<UniformRandomVariable> m_uv;        
  uint32_t m_lastUpdateTimeBlue;          
 
  // Supplied by user
  double m_increment;                     
  double m_decrement;                     
  double m_pDrop;                         
 
};
 
} // namespace ns3
 
#endif /* COBALT_H */