A Trickle Timer following RFC 6206. More...

#include "trickle-timer.h"

Collaboration diagram for ns3::TrickleTimer:

Public Member Functions
	TrickleTimer ()
	Constructor. More...

	TrickleTimer (Time minInterval, uint8_t doublings, uint16_t redundancy)
	Constructor. More...

	~TrickleTimer ()
	Destructor. More...

int64_t	AssignStreams (int64_t streamNum)
	Assigns the stream number for the uniform random number generator to use. More...

void	ConsistentEvent ()
	Records a consistent event. More...

void	Enable ()
	Enable the timer. More...

Time	GetDelayLeft (void) const

uint8_t	GetDoublings (void) const
	Get the doublings of the timer. More...

Time	GetIntervalLeft (void) const

Time	GetMaxInterval (void) const
	Get the MaxInterval of the timer. More...

Time	GetMinInterval (void) const
	Get the MinInterval of the timer. More...

uint16_t	GetRedundancy (void) const
	Get the Redundancy constant of the timer. More...

void	InconsistentEvent ()
	Records an inconsistent event. More...

void	Reset ()
	Reset the timer. More...

template<typename FN >
void	SetFunction (FN fn)
	Set the function to execute when the timer expires. More...

template<typename MEM_PTR , typename OBJ_PTR >
void	SetFunction (MEM_PTR memPtr, OBJ_PTR objPtr)
	Set the function to execute when the timer expires. More...

void	SetParameters (Time minInterval, uint8_t doublings, uint16_t redundancy)
	Set the timer parameters. More...

void	Stop ()
	Stop the timer. More...


template<typename... Ts>
void	SetArguments (Ts &&... args)
	Set the arguments to be used when invoking the expire function. More...

Private Member Functions
void	IntervalExpire (void)
	Internal callback invoked when the interval expires. More...

void	TimerExpire (void)
	Internal callback invoked when the timer expires. More...

Private Attributes
uint16_t	m_counter
	Event counter. More...

Time	m_currentInterval
	Current interval. More...

TimerImpl *	m_impl
	The timer implementation, which contains the bound callback function and arguments. More...

EventId	m_intervalExpiration
	The future event scheduled to expire the interval. More...

Time	m_maxInterval
	Maximum interval. More...

Time	m_minInterval
	Minimum interval. More...

uint16_t	m_redundancy
	Redundancy constant. More...

uint64_t	m_ticks
	Interval span (i.e., exp2(doublings)). More...

EventId	m_timerExpiration
	The future event scheduled to expire the timer. More...

Ptr< UniformRandomVariable >	m_uniRand
	Object to generate uniform random numbers. More...

Detailed Description

A Trickle Timer following RFC 6206.

A Trickle Timer is a timer that varies its frequency between a minimum and a maximum, depending on events. It is typically used to exchange information in a highly robust, energy efficient, simple, and scalable manner.

The Trickle Timer has three parameters:

minInterval Minimum interval.
doublings Number of doublings to reach the maximum interval.
redundancy Redundancy constant.

The timer period is variable. It starts at minInterval, and it doubles the period length up to maxInterval = std::exp2 (doublings) * minInterval.

The period is reset to minInterval when an inconsistent event is detected (see TrickleTimer::InconsistentEvent).

The actual function fired by the timer is not called when a period expires. Rather, it is called in random moment between half of the actual period, and the end of actual the period. Moreover, the function is not fired if the timer did detect in the actual period a number of consistent events (see TrickleTimer::ConsistentEvent) greater than the redundancy constant. Setting the redundancy constant to zero disables this feature.

The Trickle Timer is mainly used to self-regulate the transmission of periodic information (e.g., Router Advertisements) in wireless networks - and particularly in LLNs. In these contexts the frequency of the timer is adjusted according to, e.g., RS multicast messages. Moreover, the redundancy constant can be used to avoid congestion in high density networks.

Please refer to RFC 6206 for a full description and discussion of the Trickle Timer.

Definition at line 73 of file trickle-timer.h.

Constructor & Destructor Documentation

◆ TrickleTimer() [1/2]

ns3::TrickleTimer::TrickleTimer ( )

Constructor.

Definition at line 30 of file trickle-timer.cc.

References m_maxInterval, m_minInterval, m_redundancy, m_ticks, and NS_LOG_FUNCTION.

◆ TrickleTimer() [2/2]

ns3::TrickleTimer::TrickleTimer	(	Time	minInterval,
		uint8_t	doublings,
		uint16_t	redundancy
	)

Constructor.

The maximum interval is set to std::exp2 (doublings) * minInterval.

Parameters

minInterval	Minimum interval.
doublings	Number of doublings to reach the maximum interval.
redundancy	Redundancy constant.

A zero value in the redundancy constant means that the suppression algorithm is disabled.

Definition at line 46 of file trickle-timer.cc.

References m_maxInterval, m_minInterval, m_redundancy, m_ticks, NS_ASSERT_MSG, and NS_LOG_FUNCTION.

◆ ~TrickleTimer()

ns3::TrickleTimer::~TrickleTimer ( )

Destructor.

Definition at line 64 of file trickle-timer.cc.

References ns3::EventId::Cancel(), m_impl, m_intervalExpiration, m_timerExpiration, and NS_LOG_FUNCTION.

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Member Function Documentation

◆ AssignStreams()

int64_t ns3::TrickleTimer::AssignStreams ( int64_t streamNum )

Assigns the stream number for the uniform random number generator to use.

Parameters

streamNum first stream index to use

Returns: the number of stream indices assigned by this helper

Definition at line 73 of file trickle-timer.cc.

References m_uniRand, and ns3::RandomVariableStream::SetStream().

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◆ ConsistentEvent()

void ns3::TrickleTimer::ConsistentEvent ( )

Records a consistent event.

Definition at line 195 of file trickle-timer.cc.

References m_counter, and NS_LOG_FUNCTION.

Referenced by ns3::tests::TrickleTimerTestCase::ConsistentEvent().

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◆ Enable()

void ns3::TrickleTimer::Enable ( )

Enable the timer.

Definition at line 167 of file trickle-timer.cc.

References ns3::UniformRandomVariable::GetInteger(), ns3::UniformRandomVariable::GetValue(), IntervalExpire(), m_counter, m_currentInterval, m_intervalExpiration, m_minInterval, m_ticks, m_timerExpiration, m_uniRand, NS_ASSERT_MSG, NS_LOG_FUNCTION, ns3::Simulator::Schedule(), and TimerExpire().

Referenced by ns3::tests::TrickleTimerTestCase::TestRedundancy(), and ns3::tests::TrickleTimerTestCase::TestSteadyState().

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◆ GetDelayLeft()

Time ns3::TrickleTimer::GetDelayLeft ( void ) const

Returns: The amount of time left until this timer expires.

This method returns zero if the timer has never been started.

Definition at line 140 of file trickle-timer.cc.

References ns3::Simulator::GetDelayLeft(), ns3::EventId::IsRunning(), m_timerExpiration, and NS_LOG_FUNCTION.

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◆ GetDoublings()

uint8_t ns3::TrickleTimer::GetDoublings ( void ) const

Get the doublings of the timer.

Returns: The doublings

Definition at line 107 of file trickle-timer.cc.

References m_ticks, and NS_LOG_FUNCTION.

Referenced by ns3::tests::TrickleTimerTestCase::TestRedundancy(), and ns3::tests::TrickleTimerTestCase::TestSteadyState().

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◆ GetIntervalLeft()

Time ns3::TrickleTimer::GetIntervalLeft ( void ) const

Returns: The amount of time left until this timer interval expires.

This method returns zero if the timer has never been started.

Definition at line 153 of file trickle-timer.cc.

References ns3::Simulator::GetDelayLeft(), ns3::EventId::IsRunning(), m_intervalExpiration, and NS_LOG_FUNCTION.

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◆ GetMaxInterval()

Time ns3::TrickleTimer::GetMaxInterval ( void ) const

Get the MaxInterval of the timer.

The timer MaxInterval is always std::exp2 (doublings) * minInterval

Returns: The MaxInterval

Definition at line 100 of file trickle-timer.cc.

References m_maxInterval, and NS_LOG_FUNCTION.

◆ GetMinInterval()

Time ns3::TrickleTimer::GetMinInterval ( void ) const

Get the MinInterval of the timer.

Returns: The MinInterval

Definition at line 93 of file trickle-timer.cc.

References m_minInterval, and NS_LOG_FUNCTION.

◆ GetRedundancy()

uint16_t ns3::TrickleTimer::GetRedundancy ( void ) const

Get the Redundancy constant of the timer.

Returns: The Redundancy

Definition at line 133 of file trickle-timer.cc.

References m_redundancy, and NS_LOG_FUNCTION.

◆ InconsistentEvent()

void ns3::TrickleTimer::InconsistentEvent ( )

Records an inconsistent event.

Definition at line 202 of file trickle-timer.cc.

References m_currentInterval, m_minInterval, NS_LOG_FUNCTION, and Reset().

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◆ IntervalExpire()

void ns3::TrickleTimer::IntervalExpire ( void )

private

Internal callback invoked when the interval expires.

Definition at line 253 of file trickle-timer.cc.

References ns3::UniformRandomVariable::GetValue(), m_counter, m_currentInterval, m_intervalExpiration, m_maxInterval, m_timerExpiration, m_uniRand, NS_LOG_FUNCTION, ns3::Simulator::Schedule(), and TimerExpire().

Referenced by Enable(), and Reset().

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◆ Reset()

void ns3::TrickleTimer::Reset ( )

Reset the timer.

Definition at line 212 of file trickle-timer.cc.

References ns3::EventId::Cancel(), ns3::UniformRandomVariable::GetValue(), IntervalExpire(), m_counter, m_currentInterval, m_intervalExpiration, m_minInterval, m_timerExpiration, m_uniRand, NS_LOG_FUNCTION, ns3::Simulator::Schedule(), and TimerExpire().

Referenced by InconsistentEvent(), ns3::tests::TrickleTimerTestCase::TestRedundancy(), and ns3::tests::TrickleTimerTestCase::TestSteadyState().

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◆ SetArguments()

template<typename... Ts>

void ns3::TrickleTimer::SetArguments ( Ts &&... args )

Set the arguments to be used when invoking the expire function.

Template Parameters

Ts	[deduced] Argument types.

Parameters

[in] args arguments

Definition at line 283 of file trickle-timer.h.

References m_impl, NS_FATAL_ERROR, and ns3::TimerImpl::SetArgs().

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◆ SetFunction() [1/2]

template<typename FN >

void ns3::TrickleTimer::SetFunction ( FN fn )

Set the function to execute when the timer expires.

Template Parameters

FN	[deduced] The type of the function.

Parameters

[in] fn The function

Store this function in this Timer for later use by Timer::Schedule.

Definition at line 268 of file trickle-timer.h.

References m_impl, and ns3::MakeTimerImpl().

Referenced by ns3::tests::TrickleTimerTestCase::TestRedundancy(), and ns3::tests::TrickleTimerTestCase::TestSteadyState().

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◆ SetFunction() [2/2]

template<typename MEM_PTR , typename OBJ_PTR >

void ns3::TrickleTimer::SetFunction	(	MEM_PTR	memPtr,
		OBJ_PTR	objPtr
	)

Set the function to execute when the timer expires.

Template Parameters

MEM_PTR	[deduced] Class method function type.
OBJ_PTR	[deduced] Class type containing the function.

Parameters

[in]	memPtr	The member function pointer
[in]	objPtr	The pointer to object

Store this function and object in this Timer for later use by Timer::Schedule.

Definition at line 275 of file trickle-timer.h.

References m_impl, and ns3::MakeTimerImpl().

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◆ SetParameters()

void ns3::TrickleTimer::SetParameters	(	Time	minInterval,
		uint8_t	doublings,
		uint16_t	redundancy
	)

Set the timer parameters.

The maximum interval is set to std::exp2 (doublings) * minInterval.

Parameters

minInterval	Minimum interval.
doublings	Number of doublings to reach the maximum interval.
redundancy	Redundancy constant.

A zero value in the redundancy constant means that the suppression algorithm is disabled.

Definition at line 80 of file trickle-timer.cc.

References m_maxInterval, m_minInterval, m_redundancy, m_ticks, NS_ASSERT_MSG, and NS_LOG_FUNCTION.

◆ Stop()

void ns3::TrickleTimer::Stop ( void )

Stop the timer.

This will reset the timer and cancel all the pending events.

Definition at line 231 of file trickle-timer.cc.

References ns3::EventId::Cancel(), m_counter, m_currentInterval, m_intervalExpiration, m_minInterval, m_timerExpiration, and NS_LOG_FUNCTION.

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◆ TimerExpire()

void ns3::TrickleTimer::TimerExpire ( void )

private

Internal callback invoked when the timer expires.

Definition at line 242 of file trickle-timer.cc.

References ns3::TimerImpl::Invoke(), m_counter, m_impl, m_redundancy, and NS_LOG_FUNCTION.

Referenced by Enable(), IntervalExpire(), and Reset().

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Member Data Documentation

◆ m_counter

uint16_t ns3::TrickleTimer::m_counter

private

Event counter.

Definition at line 249 of file trickle-timer.h.

Referenced by ConsistentEvent(), Enable(), IntervalExpire(), Reset(), Stop(), and TimerExpire().

◆ m_currentInterval

Time ns3::TrickleTimer::m_currentInterval

private

Current interval.

Definition at line 248 of file trickle-timer.h.

Referenced by Enable(), InconsistentEvent(), IntervalExpire(), Reset(), and Stop().

◆ m_impl

TimerImpl* ns3::TrickleTimer::m_impl

private

The timer implementation, which contains the bound callback function and arguments.

Definition at line 234 of file trickle-timer.h.

Referenced by SetArguments(), SetFunction(), TimerExpire(), and ~TrickleTimer().

◆ m_intervalExpiration

EventId ns3::TrickleTimer::m_intervalExpiration

private

The future event scheduled to expire the interval.

Definition at line 240 of file trickle-timer.h.

Referenced by Enable(), GetIntervalLeft(), IntervalExpire(), Reset(), Stop(), and ~TrickleTimer().

◆ m_maxInterval

Time ns3::TrickleTimer::m_maxInterval

private

Maximum interval.

Definition at line 244 of file trickle-timer.h.

Referenced by GetMaxInterval(), IntervalExpire(), SetParameters(), and TrickleTimer().

◆ m_minInterval

Time ns3::TrickleTimer::m_minInterval

private

Minimum interval.

Definition at line 243 of file trickle-timer.h.

Referenced by Enable(), GetMinInterval(), InconsistentEvent(), Reset(), SetParameters(), Stop(), and TrickleTimer().

◆ m_redundancy

uint16_t ns3::TrickleTimer::m_redundancy

private

Redundancy constant.

Definition at line 245 of file trickle-timer.h.

Referenced by GetRedundancy(), SetParameters(), TimerExpire(), and TrickleTimer().

◆ m_ticks

uint64_t ns3::TrickleTimer::m_ticks

private

Interval span (i.e., exp2(doublings)).

Definition at line 247 of file trickle-timer.h.

Referenced by Enable(), GetDoublings(), SetParameters(), and TrickleTimer().

◆ m_timerExpiration

EventId ns3::TrickleTimer::m_timerExpiration

private

The future event scheduled to expire the timer.

Definition at line 237 of file trickle-timer.h.

Referenced by Enable(), GetDelayLeft(), IntervalExpire(), Reset(), Stop(), and ~TrickleTimer().

◆ m_uniRand

Ptr<UniformRandomVariable> ns3::TrickleTimer::m_uniRand

private

Object to generate uniform random numbers.

Definition at line 251 of file trickle-timer.h.

Referenced by AssignStreams(), Enable(), IntervalExpire(), and Reset().

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

src/core/model/trickle-timer.h
src/core/model/trickle-timer.cc

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ TrickleTimer() [1/2]

◆ TrickleTimer() [2/2]

◆ ~TrickleTimer()

Member Function Documentation

◆ AssignStreams()

◆ ConsistentEvent()

◆ Enable()

◆ GetDelayLeft()

◆ GetDoublings()

◆ GetIntervalLeft()

◆ GetMaxInterval()

◆ GetMinInterval()

◆ GetRedundancy()

◆ InconsistentEvent()

◆ IntervalExpire()

◆ Reset()

◆ SetArguments()

◆ SetFunction() [1/2]

◆ SetFunction() [2/2]

◆ SetParameters()

◆ Stop()

◆ TimerExpire()

Member Data Documentation

◆ m_counter

◆ m_currentInterval

◆ m_impl

◆ m_intervalExpiration

◆ m_maxInterval

◆ m_minInterval

◆ m_redundancy

◆ m_ticks

◆ m_timerExpiration

◆ m_uniRand