A Discrete-Event Network Simulator
API
cobalt-queue-disc.h
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1/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2/*
3 * Copyright (c) 2019 NITK Surathkal
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation;
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Cobalt, the CoDel - BLUE - Alternate Queueing discipline
19 * Based on linux code.
20 *
21 * Ported to ns-3 by: Vignesh Kannan <vignesh2496@gmail.com>
22 * Harsh Lara <harshapplefan@gmail.com>
23 * Jendaipou Palmei <jendaipoupalmei@gmail.com>
24 * Shefali Gupta <shefaligups11@gmail.com>
25 * Mohit P. Tahiliani <tahiliani@nitk.edu.in>
26 *
27 */
28
29#ifndef COBALT_H
30#define COBALT_H
31
32#include "ns3/queue-disc.h"
33#include "ns3/nstime.h"
34#include "ns3/boolean.h"
35#include "ns3/data-rate.h"
36#include "ns3/simulator.h"
37#include "ns3/string.h"
38#include "ns3/traced-value.h"
39#include "ns3/random-variable-stream.h"
40#include "ns3/trace-source-accessor.h"
41
42namespace ns3 {
43
44#define REC_INV_SQRT_CACHE (16)
45#define DEFAULT_COBALT_LIMIT 1000
46
47class TraceContainer;
48
60{
61public:
66 static TypeId GetTypeId (void);
67
74
80 virtual ~CobaltQueueDisc ();
81
87 Time GetTarget (void) const;
88
94 Time GetInterval (void) const;
95
101 int64_t GetDropNext (void) const;
102
103 static constexpr const char* TARGET_EXCEEDED_DROP = "Target exceeded drop";
104 static constexpr const char* OVERLIMIT_DROP = "Overlimit drop";
105 static constexpr const char* FORCED_MARK = "forcedMark";
106 static constexpr const char* CE_THRESHOLD_EXCEEDED_MARK = "CE threshold exceeded mark";
107
113 double GetPdrop () const;
114
123 int64_t AssignStreams (int64_t stream);
124
131 int64_t Time2CoDel (Time t) const;
132
133protected:
137 virtual void DoDispose (void);
138
139private:
140 virtual bool DoEnqueue (Ptr<QueueDiscItem> item);
141 virtual Ptr<QueueDiscItem> DoDequeue (void);
142 virtual Ptr<const QueueDiscItem> DoPeek (void);
143 virtual bool CheckConfig (void);
144
148 virtual void InitializeParams (void);
149
155 void NewtonStep (void);
156
166 int64_t ControlLaw (int64_t t);
167
171 void InvSqrt (void);
172
183 void CacheInit (void);
184
192 bool CoDelTimeAfter (int64_t a, int64_t b);
193
200 bool CoDelTimeAfterEq (int64_t a, int64_t b);
201
206 void CobaltQueueFull (int64_t now);
207
212 void CobaltQueueEmpty (int64_t now);
213
221 bool CobaltShouldDrop (Ptr<QueueDiscItem> item, int64_t now);
222
223 // Common to CoDel and Blue
224 // Maintained by Cobalt
226
227 // Codel parameters
228 // Maintained by Cobalt
234
235 // Supplied by user
238 bool m_useEcn;
240 bool m_useL4s;
242
243 // Blue parameters
244 // Maintained by Cobalt
247
248 // Supplied by user
249 double m_increment;
250 double m_decrement;
251 double m_pDrop;
252
253};
254
255} // namespace ns3
256
257#endif /* COBALT_H */
Cobalt packet queue disc.
Time m_ceThreshold
Threshold above which to CE mark.
uint32_t m_recInvSqrtCache[REC_INV_SQRT_CACHE]
Cache to maintain some initial values of InvSqrt.
Time m_target
target queue delay
static constexpr const char * CE_THRESHOLD_EXCEEDED_MARK
Sojourn time above CE threshold.
virtual Ptr< QueueDiscItem > DoDequeue(void)
This function actually extracts a packet from the queue disc.
bool CoDelTimeAfterEq(int64_t a, int64_t b)
Check if CoDel time a is successive or equal to b.
virtual Ptr< const QueueDiscItem > DoPeek(void)
Return a copy of the next packet the queue disc will extract.
double GetPdrop() const
Get the drop probability of Blue.
int64_t AssignStreams(int64_t stream)
Assign a fixed random variable stream number to the random variables used by this model.
virtual void DoDispose(void)
Dispose of the object.
virtual bool DoEnqueue(Ptr< QueueDiscItem > item)
This function actually enqueues a packet into the queue disc.
int64_t GetDropNext(void) const
Get the time for next packet drop while in the dropping state.
TracedValue< uint32_t > m_count
Number of packets dropped since entering drop state.
Stats m_stats
Cobalt statistics.
virtual bool CheckConfig(void)
Check whether the current configuration is correct.
double m_increment
increment value for marking probability
void CacheInit(void)
There is a big difference in timing between the accurate values placed in the cache and the approxima...
void CobaltQueueFull(int64_t now)
Called when the queue becomes full to alter the drop probabilities of Blue.
Time m_interval
sliding minimum time window width
double m_decrement
decrement value for marking probability
bool CobaltShouldDrop(Ptr< QueueDiscItem > item, int64_t now)
Called to decide whether the current packet should be dropped based on decisions taken by Blue and Co...
void InvSqrt(void)
Updates the inverse square root.
Time GetTarget(void) const
Get the target queue delay.
static constexpr const char * TARGET_EXCEEDED_DROP
Sojourn time above target.
int64_t Time2CoDel(Time t) const
Return the unsigned 32-bit integer representation of the input Time object.
bool CoDelTimeAfter(int64_t a, int64_t b)
Check if CoDel time a is successive to b.
double m_pDrop
Drop Probability.
virtual void InitializeParams(void)
Initialize the queue parameters.
CobaltQueueDisc()
CobaltQueueDisc Constructor.
int64_t ControlLaw(int64_t t)
Determine the time for next drop CoDel control law is t + m_interval/sqrt(m_count).
static constexpr const char * FORCED_MARK
forced marks by Codel on ECN-enabled
virtual ~CobaltQueueDisc()
Destructor.
Time m_blueThreshold
Threshold to enable blue enhancement.
uint32_t m_recInvSqrt
Reciprocal inverse square root.
Ptr< UniformRandomVariable > m_uv
Rng stream.
uint32_t m_lastUpdateTimeBlue
Blue's last update time for drop probability.
static constexpr const char * OVERLIMIT_DROP
Overlimit dropped packet.
Time GetInterval(void) const
Get the interval.
TracedValue< bool > m_dropping
True if in dropping state.
bool m_useEcn
True if ECN is used (packets are marked instead of being dropped)
TracedValue< int64_t > m_dropNext
Time to drop next packet.
void NewtonStep(void)
Calculate the reciprocal square root of m_count by using Newton's method http://en....
void CobaltQueueEmpty(int64_t now)
Called when the queue becomes empty to alter the drop probabilities of Blue.
bool m_useL4s
True if L4S is used (ECT1 packets are marked at CE threshold)
static TypeId GetTypeId(void)
Get the type ID.
Smart pointer class similar to boost::intrusive_ptr.
Definition: ptr.h:78
QueueDisc is an abstract base class providing the interface and implementing the operations common to...
Definition: queue-disc.h:181
Simulation virtual time values and global simulation resolution.
Definition: nstime.h:104
a unique identifier for an interface.
Definition: type-id.h:59
#define REC_INV_SQRT_CACHE
Every class exported by the ns3 library is enclosed in the ns3 namespace.
Structure that keeps the queue disc statistics.
Definition: queue-disc.h:186