#include <CClockSynchronizer.hpp>

Inheritance diagram for freedm::broker::CClockSynchronizer:

Public Member Functions
	CClockSynchronizer (boost::asio::io_service &ios)
	Initialize module. More...

boost::posix_time::ptime	GetSynchronizedTime () const
	Returns the synchronized time. More...

void	HandleIncomingMessage (boost::shared_ptr< const ModuleMessage > msg, CPeerNode peer)
	Processes incoming messages from other modules. More...

void	Run ()
	Starts the synchronization algorithm. More...

void	Stop ()
	Stops the syncrhonization algorithm. More...

Protected Member Functions
CPeerNode	GetMe ()
	Gets a CPeerNode representing this process. More...

std::string	GetUUID () const
	Gets the UUID of this process. More...

Private Types
typedef std::pair< double, boost::posix_time::ptime >	DecayingWeight
	Container for decaying weights. More...

typedef std::map< MapIndex, unsigned int >	LastResponseMap
	Last responses type. More...

typedef std::pair< std::string, std::string >	MapIndex
	Does the i,j referencing. More...

typedef std::map< MapIndex, boost::posix_time::time_duration >	OffsetMap
	Stores the relative offsets. More...

typedef std::map< MapIndex, QueryRecord >	QueryMap
	Stores the outstanding clock queries. More...

typedef std::pair< unsigned int, boost::posix_time::ptime >	QueryRecord
	Query Tuple. More...

typedef std::list< TimeTuple >	ResponseList
	Stores the response pairs. More...

typedef std::map< MapIndex, ResponseList >	ResponseMap
	Stores the challenge responses. More...

typedef std::map< MapIndex, double >	SkewMap
	Type used by skews. More...

typedef std::pair< boost::posix_time::ptime, boost::posix_time::ptime >	TimeTuple
	Tuples of challenge query/response stuff. More...

typedef std::map< MapIndex, DecayingWeight >	WeightMap
	Type used by the weights. More...

Private Member Functions
ModuleMessage	CreateExchangeMessage (unsigned int k)
	Generate the exchange message. More...

ModuleMessage	CreateExchangeResponse (unsigned int k)
	Generate the exchange response message. More...

void	Exchange (const boost::system::error_code &err)
	Sends clock exchange requests to other processes. More...

double	GetWeight (MapIndex i) const
	Gets the weight with a decay. More...

void	HandleExchange (const ExchangeMessage &msg, CPeerNode peer)
	Receiver for clock exchange requests. More...

void	HandleExchangeResponse (const ExchangeResponseMessage &msg, CPeerNode peer)
	Handler for clock exchange responses. More...

void	SetWeight (MapIndex i, double w)
	Sets the weight for a process. More...

Static Private Member Functions
static boost::posix_time::time_duration	DoubleToTD (double td)
	Turn a double into a time duration. More...

static ModuleMessage	PrepareForSending (const ClockSynchronizerMessage &message)
	Wraps a clock synchronizer message in a ModuleMessage. More...

static double	TDToDouble (boost::posix_time::time_duration td)
	Turn a time duration into a double. More...

Private Attributes
boost::asio::deadline_timer	m_exchangetimer
	Time for the exchange. More...

unsigned int	m_kcounter
	The current k for identifying the freshness. More...

boost::posix_time::ptime	m_lastinteraction
	Time between interactions. More...

LastResponseMap	m_lastresponse
	The last time a node responded. More...

boost::posix_time::time_duration	m_myoffset
	My offset. More...

double	m_myskew
	My skew. More...

OffsetMap	m_offsets
	Relative offsets. More...

QueryMap	m_queries
	Outstanding Clock Queries. More...

ResponseMap	m_responses
	Old responses. More...

SkewMap	m_skews
	Relative skews. More...

WeightMap	m_weights
	Relative weights. More...

Member Typedef Documentation

typedef std::pair< double, boost::posix_time::ptime > freedm::broker::CClockSynchronizer::DecayingWeight

private

typedef std::map< MapIndex, unsigned int > freedm::broker::CClockSynchronizer::LastResponseMap

private

typedef std::pair<std::string,std::string> freedm::broker::CClockSynchronizer::MapIndex

private

typedef std::map< MapIndex, boost::posix_time::time_duration > freedm::broker::CClockSynchronizer::OffsetMap

private

typedef std::map< MapIndex, QueryRecord > freedm::broker::CClockSynchronizer::QueryMap

private

typedef std::pair<unsigned int, boost::posix_time::ptime> freedm::broker::CClockSynchronizer::QueryRecord

private

typedef std::list< TimeTuple > freedm::broker::CClockSynchronizer::ResponseList

private

typedef std::map< MapIndex, ResponseList > freedm::broker::CClockSynchronizer::ResponseMap

private

typedef std::map< MapIndex, double > freedm::broker::CClockSynchronizer::SkewMap

private

typedef std::pair<boost::posix_time::ptime, boost::posix_time::ptime> freedm::broker::CClockSynchronizer::TimeTuple

private

typedef std::map< MapIndex, DecayingWeight > freedm::broker::CClockSynchronizer::WeightMap

private

Constructor & Destructor Documentation

freedm::broker::CClockSynchronizer::CClockSynchronizer ( boost::asio::io_service & ios )

explicit

CClockSynchronizer::CClockSynchronizer

Description:: Constructs the synchronizer object

Limitations:: none

Precondition:: None

Postcondition:: Read handlers are registered and the synchronizer is ready to begin

Parameters

ios	the broker's ioservice

Member Function Documentation

ModuleMessage freedm::broker::CClockSynchronizer::CreateExchangeMessage ( unsigned int k )

private

CClockSynchronizer::ExchangeMessage

Description:: Generates the challenge message, which requests a clock reading from another process.

Limitations:: none

Precondition:: None

Postcondition:: None

Parameters

k	A sequence number to use for this request, which is a monotonically increasing value for each receiver

Returns: A prepared exchange message.

ModuleMessage freedm::broker::CClockSynchronizer::CreateExchangeResponse ( unsigned int k )

private

CClockSynchronizer::ExchangeResponse

Description:: Generates the response message. Embeds the current clock reading and the offset table for this process in a message.

Limitations:: none

Precondition:: None

Postcondition:: None

Parameters

k	A sequence number to use for this request, which is a monotonically increasing value for each receiver

Returns: A prepared response message.

boost::posix_time::time_duration freedm::broker::CClockSynchronizer::DoubleToTD ( double td )

staticprivate

CClockSynchronizer::DoubleToTD

Description:: given a double td, convert it to a boost time_duration of roughly the same value (some losses for the accuracy of posix_time

Precondition:: None

Postcondition:: None

Parameters

td	the time duration (in seconds) to convert

Returns: a time duration that is roughly the same as td.

void freedm::broker::CClockSynchronizer::Exchange ( const boost::system::error_code & err )

private

CClockSynchronizer::Exchange

Description:: Makes clock reading requests to the other processes in the system.

Limitations:: none

Precondition:: None

Postcondition:: The query table is updated and the clock offset / skew is adjusted

Parameters

err	The reason this function was called.

CPeerNode IDGIModule::GetMe ( )

protectedinherited

GetMe

Description:: Gets a CPeerNode that refers to this process.

Returns: A CPeerNode referring to this process.

boost::posix_time::ptime freedm::broker::CClockSynchronizer::GetSynchronizedTime ( ) const

CClockSynchronizer::GetSynchronizedTime

Description:: Returns the time adjusted by the set offset

Limitations:: none

Precondition:: None

Postcondition:: None

Returns: The current time as decided by the synchronization algorithm

std::string IDGIModule::GetUUID ( ) const

protectedinherited

GetUUID

Description:: Gets this process's UUID.

Returns: This process's UUID

double freedm::broker::CClockSynchronizer::GetWeight ( MapIndex i ) const

private

CClockSynchronizer::GetWeight

Description:: Returns the confidence in the relative offset between 2 nodes

Limitations:: none

Precondition:: None

Postcondition:: None

Returns: The weight of a processes clock measurement.

void freedm::broker::CClockSynchronizer::HandleExchange	(	const ExchangeMessage &	msg,
		CPeerNode	peer
	)

private

CClockSynchronizer::HandleExchange

Description:: Responds to a clock reading request issued by a remote node.

Limitations:: none

Precondition:: None

Postcondition:: An exchange response is sent to the original sender.

Parameters

msg	The message from the remote node
peer	The peer sending the message.

void freedm::broker::CClockSynchronizer::HandleExchangeResponse	(	const ExchangeResponseMessage &	msg,
		CPeerNode	peer
	)

private

CClockSynchronizer::HandleExchangeResponse

Description:: Handles the clock reading response from the remote node

Limitations:: none

Precondition:: None

Postcondition:: Internal tables and state are updated, based on a linear regression created from this response and previous responses.

Parameters

msg	The message from the remote node
peer	The remote node.

void freedm::broker::CClockSynchronizer::HandleIncomingMessage	(	boost::shared_ptr< const ModuleMessage >	msg,
		CPeerNode	peer
	)

virtual

CClockSyncronizer::HandleIncoming Message

Description:: : Takes an incoming message, determines its type and passes it to the appropriate message handler.

Parameters

msg	the incoming message
peer	the node that sent this message (could be this DGI)

Implements freedm::broker::IDGIModule.

ModuleMessage freedm::broker::CClockSynchronizer::PrepareForSending ( const ClockSynchronizerMessage & message )

staticprivate

CClockSynchronizer::PrepareForSending

Description:: Wraps a ClockSynchronizerMessage in a ModuleMessage.

Parameters

message the message to prepare. If any required field is unset, an exception will be thrown.

Precondition:: None

Postcondition:: None

Returns: a ModuleMessage containing a copy of the ClockSynchronizerMessage

void freedm::broker::CClockSynchronizer::Run ( )

CClockSynchronizer::Run()

Description:: Schedule's the synchronizer's behavior and starts the synchronization algorithm.

Limitations:: none

Precondition:: None

Postcondition:: The exchange timer is set and the first round will run in QUERY_INTERVAL milliseconds

void freedm::broker::CClockSynchronizer::SetWeight	(	MapIndex	i,
		double	w
	)

private

CClockSynchronizer::setWeight

Description:: Updates the weights table

Limitations:: none

Precondition:: None

Postcondition:: None

Parameters

i	The weight to update
w	The amount of weight

void freedm::broker::CClockSynchronizer::Stop ( )

CClockSynchronizer::Stop()

Description:: Stops the clock synchronizer.

Limitations:: none

Precondition:: None

Postcondition:: The timer is canceled.

double freedm::broker::CClockSynchronizer::TDToDouble ( boost::posix_time::time_duration td )

staticprivate

CClockSynchronizer::TDToDouble

Description:: give a time duration td, convert it to a double which represents the number of seconds the time duration represents

Precondition:: None

Postcondition:: None

Parameters

td	the time duration to convert

Returns: a double of the time duration, in seconds.

Member Data Documentation

boost::asio::deadline_timer freedm::broker::CClockSynchronizer::m_exchangetimer

private

unsigned int freedm::broker::CClockSynchronizer::m_kcounter

private

boost::posix_time::ptime freedm::broker::CClockSynchronizer::m_lastinteraction

private

LastResponseMap freedm::broker::CClockSynchronizer::m_lastresponse

private

boost::posix_time::time_duration freedm::broker::CClockSynchronizer::m_myoffset

private

double freedm::broker::CClockSynchronizer::m_myskew

private

OffsetMap freedm::broker::CClockSynchronizer::m_offsets

private

QueryMap freedm::broker::CClockSynchronizer::m_queries

private

ResponseMap freedm::broker::CClockSynchronizer::m_responses

private

SkewMap freedm::broker::CClockSynchronizer::m_skews

private

WeightMap freedm::broker::CClockSynchronizer::m_weights

private

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

/home/docs/checkouts/readthedocs.org/user_builds/freedm/checkouts/latest/Broker/src/CClockSynchronizer.hpp
/home/docs/checkouts/readthedocs.org/user_builds/freedm/checkouts/latest/Broker/src/CClockSynchronizer.cpp

Public Member Functions

Protected Member Functions

Private Types

Private Member Functions

Static Private Member Functions

Private Attributes

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation