A Discrete-Event Network Simulator
API
ns3::CobaltQueueDisc Class Reference

Cobalt packet queue disc. More...

#include "cobalt-queue-disc.h"

+ Inheritance diagram for ns3::CobaltQueueDisc:
+ Collaboration diagram for ns3::CobaltQueueDisc:

Public Member Functions

 CobaltQueueDisc ()
 CobaltQueueDisc Constructor. More...
 
virtual ~CobaltQueueDisc ()
 Destructor. More...
 
int64_t AssignStreams (int64_t stream)
 Assign a fixed random variable stream number to the random variables used by this model. More...
 
int64_t GetDropNext (void)
 Get the time for next packet drop while in the dropping state. More...
 
Time GetInterval (void)
 Get the interval. More...
 
double GetPdrop ()
 Get the drop probability of Blue. More...
 
Time GetTarget (void)
 Get the target queue delay. More...
 
int64_t Time2CoDel (Time t)
 Return the unsigned 32-bit integer representation of the input Time object. More...
 
- Public Member Functions inherited from ns3::QueueDisc
 QueueDisc (QueueDiscSizePolicy policy=QueueDiscSizePolicy::SINGLE_INTERNAL_QUEUE)
 Constructor. More...
 
 QueueDisc (QueueDiscSizePolicy policy, QueueSizeUnit unit)
 Constructor. More...
 
virtual ~QueueDisc ()
 
void AddInternalQueue (Ptr< InternalQueue > queue)
 Add an internal queue to the tail of the list of queues. More...
 
void AddPacketFilter (Ptr< PacketFilter > filter)
 Add a packet filter to the tail of the list of filters used to classify packets. More...
 
void AddQueueDiscClass (Ptr< QueueDiscClass > qdClass)
 Add a queue disc class to the tail of the list of classes. More...
 
int32_t Classify (Ptr< QueueDiscItem > item)
 Classify a packet by calling the packet filters, one at a time, until either a filter able to classify the packet is found or all the filters have been processed. More...
 
Ptr< QueueDiscItemDequeue (void)
 Extract from the queue disc the packet that has been dequeued by calling Peek, if any, or call the private DoDequeue method (which must be implemented by derived classes) to dequeue a packet, otherwise. More...
 
bool Enqueue (Ptr< QueueDiscItem > item)
 Pass a packet to store to the queue discipline. More...
 
QueueSize GetCurrentSize (void)
 Get the current size of the queue disc in bytes, if operating in bytes mode, or packets, otherwise. More...
 
Ptr< InternalQueueGetInternalQueue (std::size_t i) const
 Get the i-th internal queue. More...
 
QueueSize GetMaxSize (void) const
 Get the maximum size of the queue disc. More...
 
uint32_t GetNBytes (void) const
 Get the amount of bytes stored by the queue disc. More...
 
Ptr< NetDeviceQueueInterfaceGetNetDeviceQueueInterface (void) const
 
std::size_t GetNInternalQueues (void) const
 Get the number of internal queues. More...
 
std::size_t GetNPacketFilters (void) const
 Get the number of packet filters. More...
 
uint32_t GetNPackets (void) const
 Get the number of packets stored by the queue disc. More...
 
std::size_t GetNQueueDiscClasses (void) const
 Get the number of queue disc classes. More...
 
Ptr< PacketFilterGetPacketFilter (std::size_t i) const
 Get the i-th packet filter. More...
 
Ptr< QueueDiscClassGetQueueDiscClass (std::size_t i) const
 Get the i-th queue disc class. More...
 
virtual uint32_t GetQuota (void) const
 Get the maximum number of dequeue operations following a packet enqueue. More...
 
SendCallback GetSendCallback (void) const
 
const StatsGetStats (void)
 Retrieve all the collected statistics. More...
 
virtual WakeMode GetWakeMode (void) const
 When setting up the wake callbacks on the netdevice queues, it is necessary to determine which queue disc (the root queue disc or one of its children) should be activated when the netdevice wakes one of its transmission queues. More...
 
Ptr< const QueueDiscItemPeek (void)
 Get a copy of the next packet the queue discipline will extract. More...
 
void Run (void)
 Modelled after the Linux function __qdisc_run (net/sched/sch_generic.c) Dequeues multiple packets, until a quota is exceeded or sending a packet to the device failed. More...
 
bool SetMaxSize (QueueSize size)
 Set the maximum size of the queue disc. More...
 
void SetNetDeviceQueueInterface (Ptr< NetDeviceQueueInterface > ndqi)
 
virtual void SetQuota (const uint32_t quota)
 Set the maximum number of dequeue operations following a packet enqueue. More...
 
void SetSendCallback (SendCallback func)
 
- Public Member Functions inherited from ns3::Object
 Object ()
 Constructor. More...
 
virtual ~Object ()
 Destructor. More...
 
void AggregateObject (Ptr< Object > other)
 Aggregate two Objects together. More...
 
void Dispose (void)
 Dispose of this Object. More...
 
AggregateIterator GetAggregateIterator (void) const
 Get an iterator to the Objects aggregated to this one. More...
 
virtual TypeId GetInstanceTypeId (void) const
 Get the most derived TypeId for this Object. More...
 
template<typename T >
Ptr< T > GetObject (void) const
 Get a pointer to the requested aggregated Object. More...
 
template<typename T >
Ptr< T > GetObject (TypeId tid) const
 Get a pointer to the requested aggregated Object by TypeId. More...
 
void Initialize (void)
 Invoke DoInitialize on all Objects aggregated to this one. More...
 
bool IsInitialized (void) const
 Check if the object has been initialized. More...
 
- Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
 SimpleRefCount ()
 Default constructor. More...
 
 SimpleRefCount (const SimpleRefCount &o)
 Copy constructor. More...
 
uint32_t GetReferenceCount (void) const
 Get the reference count of the object. More...
 
SimpleRefCountoperator= (const SimpleRefCount &o)
 Assignment operator. More...
 
void Ref (void) const
 Increment the reference count. More...
 
void Unref (void) const
 Decrement the reference count. More...
 
- Public Member Functions inherited from ns3::ObjectBase
virtual ~ObjectBase ()
 Virtual destructor. More...
 
void GetAttribute (std::string name, AttributeValue &value) const
 Get the value of an attribute, raising fatal errors if unsuccessful. More...
 
bool GetAttributeFailSafe (std::string name, AttributeValue &value) const
 Get the value of an attribute without raising erros. More...
 
void SetAttribute (std::string name, const AttributeValue &value)
 Set a single attribute, raising fatal errors if unsuccessful. More...
 
bool SetAttributeFailSafe (std::string name, const AttributeValue &value)
 Set a single attribute without raising errors. More...
 
bool TraceConnect (std::string name, std::string context, const CallbackBase &cb)
 Connect a TraceSource to a Callback with a context. More...
 
bool TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
 Connect a TraceSource to a Callback without a context. More...
 
bool TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
 Disconnect from a TraceSource a Callback previously connected with a context. More...
 
bool TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
 Disconnect from a TraceSource a Callback previously connected without a context. More...
 

Static Public Member Functions

static TypeId GetTypeId (void)
 Get the type ID. More...
 
- Static Public Member Functions inherited from ns3::QueueDisc
static TypeId GetTypeId (void)
 Get the type ID. More...
 
- Static Public Member Functions inherited from ns3::Object
static TypeId GetTypeId (void)
 Register this type. More...
 
- Static Public Member Functions inherited from ns3::ObjectBase
static TypeId GetTypeId (void)
 Get the type ID. More...
 

Static Public Attributes

static constexpr const char * FORCED_MARK = "forcedMark"
 forced marks by Codel on ECN-enabled More...
 
static constexpr const char * OVERLIMIT_DROP = "Overlimit drop"
 Overlimit dropped packet. More...
 
static constexpr const char * TARGET_EXCEEDED_DROP = "Target exceeded drop"
 Sojourn time above target. More...
 
- Static Public Attributes inherited from ns3::QueueDisc
static constexpr const char * CHILD_QUEUE_DISC_DROP = "(Dropped by child queue disc) "
 Packet dropped by a child queue disc. More...
 
static constexpr const char * CHILD_QUEUE_DISC_MARK = "(Marked by child queue disc) "
 Packet marked by a child queue disc. More...
 
static constexpr const char * INTERNAL_QUEUE_DROP = "Dropped by internal queue"
 Packet dropped by an internal queue. More...
 

Protected Member Functions

virtual void DoDispose (void)
 Dispose of the object. More...
 
- Protected Member Functions inherited from ns3::QueueDisc
void DoInitialize (void)
 Check whether the configuration is correct and initialize parameters. More...
 
void DropAfterDequeue (Ptr< const QueueDiscItem > item, const char *reason)
 Perform the actions required when the queue disc is notified of a packet dropped after dequeue. More...
 
void DropBeforeEnqueue (Ptr< const QueueDiscItem > item, const char *reason)
 Perform the actions required when the queue disc is notified of a packet dropped before enqueue. More...
 
bool Mark (Ptr< QueueDiscItem > item, const char *reason)
 Marks the given packet and, if successful, updates the counters associated with the given reason. More...
 
- Protected Member Functions inherited from ns3::Object
 Object (const Object &o)
 Copy an Object. More...
 
virtual void NotifyNewAggregate (void)
 Notify all Objects aggregated to this one of a new Object being aggregated. More...
 
- Protected Member Functions inherited from ns3::ObjectBase
void ConstructSelf (const AttributeConstructionList &attributes)
 Complete construction of ObjectBase; invoked by derived classes. More...
 
virtual void NotifyConstructionCompleted (void)
 Notifier called once the ObjectBase is fully constructed. More...
 

Private Member Functions

void CacheInit (void)
 There is a big difference in timing between the accurate values placed in the cache and the approximations given by a single Newton step for small count values, particularly when stepping from count 1 to 2 or vice versa. More...
 
virtual bool CheckConfig (void)
 Check whether the current configuration is correct. More...
 
void CobaltQueueEmpty (int64_t now)
 Called when the queue becomes empty to alter the drop probabilities of Blue. More...
 
void CobaltQueueFull (int64_t now)
 Called when the queue becomes full to alter the drop probabilities of Blue. More...
 
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 Codel working parallely Returns true if the packet should be dropped, false otherwise. More...
 
bool CoDelTimeAfter (int64_t a, int64_t b)
 Check if CoDel time a is successive to b. More...
 
bool CoDelTimeAfterEq (int64_t a, int64_t b)
 Check if CoDel time a is successive or equal to b. More...
 
int64_t ControlLaw (int64_t t)
 Determine the time for next drop CoDel control law is t + m_interval/sqrt(m_count). More...
 
virtual Ptr< QueueDiscItemDoDequeue (void)
 This function actually extracts a packet from the queue disc. More...
 
virtual bool DoEnqueue (Ptr< QueueDiscItem > item)
 This function actually enqueues a packet into the queue disc. More...
 
virtual Ptr< const QueueDiscItemDoPeek (void)
 Return a copy of the next packet the queue disc will extract. More...
 
virtual void InitializeParams (void)
 Initialize the queue parameters. More...
 
void InvSqrt (void)
 
void NewtonStep (void)
 Calculate the reciprocal square root of m_count by using Newton's method http://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Iterative_methods_for_reciprocal_square_roots m_recInvSqrt (new) = (m_recInvSqrt (old) / 2) * (3 - m_count * m_recInvSqrt^2) More...
 

Private Attributes

TracedValue< uint32_t > m_count
 Number of packets dropped since entering drop state. More...
 
double m_decrement
 decrement value for marking probability More...
 
TracedValue< int64_t > m_dropNext
 Time to drop next packet. More...
 
TracedValue< bool > m_dropping
 True if in dropping state. More...
 
double m_increment
 increment value for marking probability More...
 
Time m_interval
 100 ms sliding minimum time window width More...
 
uint32_t m_lastUpdateTimeBlue
 Blue's last update time for drop probability. More...
 
uint32_t m_minBytes
 Minimum bytes in queue to allow a packet drop. More...
 
double m_Pdrop
 Drop Probability. More...
 
uint32_t m_recInvSqrt
 Reciprocal inverse square root. More...
 
uint32_t m_recInvSqrtCache [REC_INV_SQRT_CACHE] = {0}
 Cache to maintain some initial values of InvSqrt. More...
 
Stats m_stats
 Cobalt statistics. More...
 
Time m_target
 5 ms target queue delay More...
 
bool m_useEcn
 True if ECN is used (packets are marked instead of being dropped) More...
 
Ptr< UniformRandomVariablem_uv
 Rng stream. More...
 

Additional Inherited Members

- Public Types inherited from ns3::QueueDisc
typedef Queue< QueueDiscItemInternalQueue
 Internal queues store QueueDiscItem objects. More...
 
typedef std::function< void(Ptr< QueueDiscItem >)> SendCallback
 Callback invoked to send a packet to the receiving object when Run is called. More...
 
enum  WakeMode { WAKE_ROOT = 0x00, WAKE_CHILD = 0x01 }
 Used to determine whether the queue disc itself or its children must be activated when a netdevice wakes a transmission queue. More...
 

Detailed Description

Cobalt packet queue disc.


Introspection did not find any typical Config paths.

Cobalt uses CoDel and BLUE algorithms in parallel, in order to obtain the best features of each. CoDel is excellent on flows which respond to congestion signals in a TCP-like way. BLUE is far more effective on unresponsive flows.


Attributes

  • MaxSize: The maximum number of packets/bytes accepted by this queue disc.
  • MinBytes: The Cobalt algorithm minbytes parameter.
    • Set with class: ns3::UintegerValue
    • Underlying type: uint32_t 0:4294967295
    • Initial value: 1500
    • Flags: construct write read
  • Interval: The Cobalt algorithm interval
    • Set with class: ns3::TimeValue
    • Underlying type: Time –9223372036854775808.0ns:+9223372036854775807.0ns
    • Initial value: 100ms
    • Flags: construct write read
  • Target: The Cobalt algorithm target queue delay
    • Set with class: ns3::TimeValue
    • Underlying type: Time –9223372036854775808.0ns:+9223372036854775807.0ns
    • Initial value: 5ms
    • Flags: construct write read
  • UseEcn: True to use ECN (packets are marked instead of being dropped)
    • Set with class: BooleanValue
    • Underlying type: bool
    • Initial value: false
    • Flags: construct write read
  • Pdrop: Marking Probability
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 0
    • Flags: construct write read
  • Increment: Pdrop increment value
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 0.00390625
    • Flags: construct write read
  • Decrement: Pdrop decrement Value
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 0.000244141
    • Flags: construct write read

Attributes defined in parent class ns3::QueueDisc

TraceSources

TraceSources defined in parent class ns3::QueueDisc

Size of this type is 1608 bytes (on a 64-bit architecture).

Definition at line 59 of file cobalt-queue-disc.h.

Constructor & Destructor Documentation

◆ CobaltQueueDisc()

ns3::CobaltQueueDisc::CobaltQueueDisc ( )

CobaltQueueDisc Constructor.

Create a Cobalt queue disc

Definition at line 144 of file cobalt-queue-disc.cc.

References InitializeParams(), m_uv, and NS_LOG_FUNCTION.

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◆ ~CobaltQueueDisc()

ns3::CobaltQueueDisc::~CobaltQueueDisc ( )
virtual

Destructor.

Destructor

Definition at line 157 of file cobalt-queue-disc.cc.

References NS_LOG_FUNCTION.

Member Function Documentation

◆ AssignStreams()

int64_t ns3::CobaltQueueDisc::AssignStreams ( int64_t  stream)

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.

Parameters
streamfirst stream index to use
Returns
the number of stream indices assigned by this model

Definition at line 163 of file cobalt-queue-disc.cc.

References m_uv, NS_LOG_FUNCTION, and ns3::RandomVariableStream::SetStream().

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◆ CacheInit()

void ns3::CobaltQueueDisc::CacheInit ( void  )
private

There is a big difference in timing between the accurate values placed in the cache and the approximations given by a single Newton step for small count values, particularly when stepping from count 1 to 2 or vice versa.

Above 16, a single Newton step gives sufficient accuracy in either direction, given the precision stored.

The magnitude of the error when stepping up to count 2 is such as to give the value that should have been produced at count 4.

Definition at line 234 of file cobalt-queue-disc.cc.

References m_count, m_recInvSqrt, m_recInvSqrtCache, NewtonStep(), and REC_INV_SQRT_CACHE.

Referenced by InitializeParams().

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◆ CheckConfig()

bool ns3::CobaltQueueDisc::CheckConfig ( void  )
privatevirtual

Check whether the current configuration is correct.

Default objects (such as internal queues) might be created by this method to ensure the configuration is correct. This method is automatically called at simulation initialization time, and it is called before the InitializeParams () method. It is appropriate to promote parameter initialization to this method if it aids in checking for correct configuration.

See also
QueueDisc::InitializeParams
Returns
true if the configuration is correct, false otherwise

Implements ns3::QueueDisc.

Definition at line 296 of file cobalt-queue-disc.cc.

References ns3::QueueDisc::AddInternalQueue(), ns3::CreateObjectWithAttributes(), ns3::QueueDisc::GetMaxSize(), ns3::QueueDisc::GetNInternalQueues(), ns3::QueueDisc::GetNPacketFilters(), ns3::QueueDisc::GetNQueueDiscClasses(), NS_LOG_ERROR, and NS_LOG_FUNCTION.

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◆ CobaltQueueEmpty()

void ns3::CobaltQueueDisc::CobaltQueueEmpty ( int64_t  now)
private

Called when the queue becomes empty to alter the drop probabilities of Blue.

Definition at line 413 of file cobalt-queue-disc.cc.

References CoDelTimeAfter(), CoDelTimeAfterEq(), ControlLaw(), InvSqrt(), m_count, m_decrement, m_dropNext, m_dropping, m_lastUpdateTimeBlue, m_Pdrop, m_target, ns3::max(), NS_LOG_FUNCTION, and Time2CoDel().

Referenced by DoDequeue().

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◆ CobaltQueueFull()

void ns3::CobaltQueueDisc::CobaltQueueFull ( int64_t  now)
private

Called when the queue becomes full to alter the drop probabilities of Blue.

Definition at line 394 of file cobalt-queue-disc.cc.

References CoDelTimeAfter(), m_count, m_dropNext, m_dropping, m_increment, m_lastUpdateTimeBlue, m_Pdrop, m_target, ns3::min(), NS_LOG_FUNCTION, NS_LOG_LOGIC(), and Time2CoDel().

Referenced by DoEnqueue().

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◆ CobaltShouldDrop()

bool ns3::CobaltQueueDisc::CobaltShouldDrop ( Ptr< QueueDiscItem item,
int64_t  now 
)
private

Called to decide whether the current packet should be dropped based on decisions taken by Blue and Codel working parallely Returns true if the packet should be dropped, false otherwise.

Definition at line 432 of file cobalt-queue-disc.cc.

References CoDelTimeAfter(), ControlLaw(), FORCED_MARK, ns3::Time::GetSeconds(), ns3::UniformRandomVariable::GetValue(), InvSqrt(), m_count, m_dropNext, m_dropping, m_interval, m_Pdrop, m_target, m_useEcn, m_uv, ns3::QueueDisc::Mark(), ns3::max(), ns3::Simulator::Now(), NS_LOG_FUNCTION, NS_LOG_INFO, and Time2CoDel().

Referenced by DoDequeue().

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◆ CoDelTimeAfter()

bool ns3::CobaltQueueDisc::CoDelTimeAfter ( int64_t  a,
int64_t  b 
)
private

Check if CoDel time a is successive to b.

Parameters
aleft operand
bright operand
Returns
true if a is greater than b

Definition at line 185 of file cobalt-queue-disc.cc.

Referenced by CobaltQueueEmpty(), CobaltQueueFull(), and CobaltShouldDrop().

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◆ CoDelTimeAfterEq()

bool ns3::CobaltQueueDisc::CoDelTimeAfterEq ( int64_t  a,
int64_t  b 
)
private

Check if CoDel time a is successive or equal to b.

Parameters
aleft operand
bright operand
Returns
true if a is greater than or equal to b

Definition at line 191 of file cobalt-queue-disc.cc.

Referenced by CobaltQueueEmpty().

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◆ ControlLaw()

int64_t ns3::CobaltQueueDisc::ControlLaw ( int64_t  t)
private

Determine the time for next drop CoDel control law is t + m_interval/sqrt(m_count).

Here, we use m_recInvSqrt calculated by Newton's method in NewtonStep() to avoid both sqrt() and divide operations

Parameters
tCurrent next drop time
Returns
The new next drop time:

Definition at line 263 of file cobalt-queue-disc.cc.

References m_interval, m_recInvSqrt, NS_LOG_FUNCTION, ns3::ReciprocalDivide(), and Time2CoDel().

Referenced by CobaltQueueEmpty(), and CobaltShouldDrop().

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◆ DoDequeue()

Ptr< QueueDiscItem > ns3::CobaltQueueDisc::DoDequeue ( void  )
privatevirtual

This function actually extracts a packet from the queue disc.

Returns
0 if the operation was not successful; the item otherwise.

Implements ns3::QueueDisc.

Definition at line 354 of file cobalt-queue-disc.cc.

References CobaltQueueEmpty(), CobaltShouldDrop(), ns3::CoDelGetTime(), ns3::QueueDisc::DropAfterDequeue(), ns3::QueueDisc::GetInternalQueue(), ns3::QueueDisc::GetNBytes(), ns3::QueueDisc::GetNPackets(), m_dropping, NS_LOG_FUNCTION, NS_LOG_LOGIC(), and TARGET_EXCEEDED_DROP.

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◆ DoDispose()

void ns3::CobaltQueueDisc::DoDispose ( void  )
protectedvirtual

Dispose of the object.

Reimplemented from ns3::QueueDisc.

Definition at line 270 of file cobalt-queue-disc.cc.

References ns3::QueueDisc::DoDispose(), m_uv, and NS_LOG_FUNCTION.

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◆ DoEnqueue()

bool ns3::CobaltQueueDisc::DoEnqueue ( Ptr< QueueDiscItem item)
privatevirtual

This function actually enqueues a packet into the queue disc.

Parameters
itemitem to enqueue
Returns
True if the operation was successful; false otherwise

Implements ns3::QueueDisc.

Definition at line 328 of file cobalt-queue-disc.cc.

References CobaltQueueFull(), ns3::CoDelGetTime(), ns3::QueueDisc::DropBeforeEnqueue(), ns3::QueueDisc::GetCurrentSize(), ns3::QueueDisc::GetInternalQueue(), ns3::QueueDisc::GetMaxSize(), ns3::QueueDisc::GetNBytes(), ns3::QueueDisc::GetNPackets(), NS_LOG_FUNCTION, NS_LOG_LOGIC(), and OVERLIMIT_DROP.

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◆ DoPeek()

Ptr< const QueueDiscItem > ns3::CobaltQueueDisc::DoPeek ( void  )
privatevirtual

Return a copy of the next packet the queue disc will extract.

The implementation of this method is based on the qdisc_peek_dequeued function of the Linux kernel, which dequeues a packet and retains it in the queue disc as a requeued packet. The packet is not traced as requeued, nor is the total count of requeued packets increased. The packet is still considered to be part of the queue disc and the dequeue trace is fired when Dequeue is called and the packet is actually extracted from the queue disc.

This approach is especially recommended for queue discs for which it is not obvious what is the next packet that will be dequeued (e.g., queue discs having multiple internal queues or child queue discs or queue discs that drop packets after dequeue). Subclasses can however provide their own implementation of this method that overrides the default one.

Returns
0 if the operation was not successful; the packet otherwise.

Reimplemented from ns3::QueueDisc.

Definition at line 278 of file cobalt-queue-disc.cc.

References ns3::QueueDisc::GetInternalQueue(), ns3::QueueDisc::GetNBytes(), ns3::QueueDisc::GetNPackets(), NS_LOG_FUNCTION, and NS_LOG_LOGIC().

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◆ GetDropNext()

int64_t ns3::CobaltQueueDisc::GetDropNext ( void  )

Get the time for next packet drop while in the dropping state.

Returns
The time for next packet drop

Definition at line 215 of file cobalt-queue-disc.cc.

References m_dropNext.

◆ GetInterval()

Time ns3::CobaltQueueDisc::GetInterval ( void  )

Get the interval.

Returns
The interval

Definition at line 209 of file cobalt-queue-disc.cc.

References m_interval.

◆ GetPdrop()

double ns3::CobaltQueueDisc::GetPdrop ( )

Get the drop probability of Blue.

Returns
The current value of Blue's drop probability

Definition at line 152 of file cobalt-queue-disc.cc.

References m_Pdrop.

Referenced by CobaltQueueDiscDropTest::RunDropTest().

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◆ GetTarget()

Time ns3::CobaltQueueDisc::GetTarget ( void  )

Get the target queue delay.

Returns
The target queue delay

Definition at line 203 of file cobalt-queue-disc.cc.

References m_target.

◆ GetTypeId()

◆ InitializeParams()

void ns3::CobaltQueueDisc::InitializeParams ( void  )
privatevirtual

Initialize the queue parameters.

Implements ns3::QueueDisc.

Definition at line 171 of file cobalt-queue-disc.cc.

References CacheInit(), m_count, m_dropNext, m_dropping, m_lastUpdateTimeBlue, m_recInvSqrt, m_recInvSqrtCache, and NS_LOG_FUNCTION.

Referenced by CobaltQueueDisc().

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◆ InvSqrt()

void ns3::CobaltQueueDisc::InvSqrt ( void  )
private

Definition at line 250 of file cobalt-queue-disc.cc.

References m_count, m_recInvSqrt, m_recInvSqrtCache, NewtonStep(), and REC_INV_SQRT_CACHE.

Referenced by CobaltQueueEmpty(), and CobaltShouldDrop().

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◆ NewtonStep()

void ns3::CobaltQueueDisc::NewtonStep ( void  )
private

Calculate the reciprocal square root of m_count by using Newton's method http://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Iterative_methods_for_reciprocal_square_roots m_recInvSqrt (new) = (m_recInvSqrt (old) / 2) * (3 - m_count * m_recInvSqrt^2)

Definition at line 221 of file cobalt-queue-disc.cc.

References m_count, m_recInvSqrt, and NS_LOG_FUNCTION.

Referenced by CacheInit(), and InvSqrt().

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◆ Time2CoDel()

int64_t ns3::CobaltQueueDisc::Time2CoDel ( Time  t)

Return the unsigned 32-bit integer representation of the input Time object.

Units are microseconds

Parameters
tthe input Time Object
Returns
the unsigned 32-bit integer representation

Definition at line 197 of file cobalt-queue-disc.cc.

References ns3::Time::GetNanoSeconds().

Referenced by CobaltQueueEmpty(), CobaltQueueFull(), CobaltShouldDrop(), and ControlLaw().

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Member Data Documentation

◆ FORCED_MARK

constexpr const char* ns3::CobaltQueueDisc::FORCED_MARK = "forcedMark"
static

forced marks by Codel on ECN-enabled

Definition at line 105 of file cobalt-queue-disc.h.

Referenced by CobaltShouldDrop().

◆ m_count

TracedValue<uint32_t> ns3::CobaltQueueDisc::m_count
private

Number of packets dropped since entering drop state.

Definition at line 222 of file cobalt-queue-disc.h.

Referenced by CacheInit(), CobaltQueueEmpty(), CobaltQueueFull(), CobaltShouldDrop(), GetTypeId(), InitializeParams(), InvSqrt(), and NewtonStep().

◆ m_decrement

double ns3::CobaltQueueDisc::m_decrement
private

decrement value for marking probability

Definition at line 240 of file cobalt-queue-disc.h.

Referenced by CobaltQueueEmpty(), and GetTypeId().

◆ m_dropNext

TracedValue<int64_t> ns3::CobaltQueueDisc::m_dropNext
private

Time to drop next packet.

Definition at line 223 of file cobalt-queue-disc.h.

Referenced by CobaltQueueEmpty(), CobaltQueueFull(), CobaltShouldDrop(), GetDropNext(), GetTypeId(), and InitializeParams().

◆ m_dropping

TracedValue<bool> ns3::CobaltQueueDisc::m_dropping
private

True if in dropping state.

Definition at line 224 of file cobalt-queue-disc.h.

Referenced by CobaltQueueEmpty(), CobaltQueueFull(), CobaltShouldDrop(), DoDequeue(), GetTypeId(), and InitializeParams().

◆ m_increment

double ns3::CobaltQueueDisc::m_increment
private

increment value for marking probability

Definition at line 239 of file cobalt-queue-disc.h.

Referenced by CobaltQueueFull(), and GetTypeId().

◆ m_interval

Time ns3::CobaltQueueDisc::m_interval
private

100 ms sliding minimum time window width

Definition at line 229 of file cobalt-queue-disc.h.

Referenced by CobaltShouldDrop(), ControlLaw(), GetInterval(), and GetTypeId().

◆ m_lastUpdateTimeBlue

uint32_t ns3::CobaltQueueDisc::m_lastUpdateTimeBlue
private

Blue's last update time for drop probability.

Definition at line 236 of file cobalt-queue-disc.h.

Referenced by CobaltQueueEmpty(), CobaltQueueFull(), and InitializeParams().

◆ m_minBytes

uint32_t ns3::CobaltQueueDisc::m_minBytes
private

Minimum bytes in queue to allow a packet drop.

Definition at line 218 of file cobalt-queue-disc.h.

Referenced by GetTypeId().

◆ m_Pdrop

double ns3::CobaltQueueDisc::m_Pdrop
private

Drop Probability.

Definition at line 241 of file cobalt-queue-disc.h.

Referenced by CobaltQueueEmpty(), CobaltQueueFull(), CobaltShouldDrop(), GetPdrop(), and GetTypeId().

◆ m_recInvSqrt

uint32_t ns3::CobaltQueueDisc::m_recInvSqrt
private

Reciprocal inverse square root.

Definition at line 225 of file cobalt-queue-disc.h.

Referenced by CacheInit(), ControlLaw(), InitializeParams(), InvSqrt(), and NewtonStep().

◆ m_recInvSqrtCache

uint32_t ns3::CobaltQueueDisc::m_recInvSqrtCache[REC_INV_SQRT_CACHE] = {0}
private

Cache to maintain some initial values of InvSqrt.

Definition at line 226 of file cobalt-queue-disc.h.

Referenced by CacheInit(), InitializeParams(), and InvSqrt().

◆ m_stats

Stats ns3::CobaltQueueDisc::m_stats
private

Cobalt statistics.

Definition at line 216 of file cobalt-queue-disc.h.

◆ m_target

Time ns3::CobaltQueueDisc::m_target
private

5 ms target queue delay

Definition at line 230 of file cobalt-queue-disc.h.

Referenced by CobaltQueueEmpty(), CobaltQueueFull(), CobaltShouldDrop(), GetTarget(), and GetTypeId().

◆ m_useEcn

bool ns3::CobaltQueueDisc::m_useEcn
private

True if ECN is used (packets are marked instead of being dropped)

Definition at line 231 of file cobalt-queue-disc.h.

Referenced by CobaltShouldDrop(), and GetTypeId().

◆ m_uv

Ptr<UniformRandomVariable> ns3::CobaltQueueDisc::m_uv
private

Rng stream.

Definition at line 235 of file cobalt-queue-disc.h.

Referenced by AssignStreams(), CobaltQueueDisc(), CobaltShouldDrop(), and DoDispose().

◆ OVERLIMIT_DROP

constexpr const char* ns3::CobaltQueueDisc::OVERLIMIT_DROP = "Overlimit drop"
static

Overlimit dropped packet.

Definition at line 104 of file cobalt-queue-disc.h.

Referenced by DoEnqueue().

◆ TARGET_EXCEEDED_DROP

constexpr const char* ns3::CobaltQueueDisc::TARGET_EXCEEDED_DROP = "Target exceeded drop"
static

Sojourn time above target.

Definition at line 103 of file cobalt-queue-disc.h.

Referenced by DoDequeue().


The documentation for this class was generated from the following files: