#include <StateCollection.hpp>

Inheritance diagram for freedm::broker::sc::SCAgent:

Public Member Functions
	SCAgent ()
	Constructor. 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< std::string, int >	StateVersion

Private Member Functions
CPeerNode	AddPeer (CPeerNode peer)
	Add a peer to peer set from a pointer to a peer node object. More...

CPeerNode	GetPeer (std::string uuid)
	Get a pointer to a peer from UUID. More...

void	HandleAccept (CPeerNode peer)
	Handle receiving messages. More...

void	HandleIncomingMessage (boost::shared_ptr< const ModuleMessage > msg, CPeerNode peer)
	Handles received messages. More...

void	HandleMarker (const MarkerMessage &msg, CPeerNode peer)

void	HandlePeerList (const gm::PeerListMessage &msg, CPeerNode peer)

void	HandleRequest (const RequestMessage &msg, CPeerNode peer)

void	HandleState (const StateMessage &msg, CPeerNode peer)

void	Initiate ()
	Initiator starts state collection. More...

void	SaveForward (StateVersion latest, const MarkerMessage &msg)
	Peer save local state and forward maker. More...

void	SendStateBack ()
	Peer sends collected states back to the initiator. More...

void	StateResponse ()
	Initiator sends collected states back to the request module. More...

void	TakeSnapshot (const std::vector< std::string > &devicelist)
	Save local state. More...

Static Private Member Functions
static ModuleMessage	PrepareForSending (const StateCollectionMessage &message, std::string recipient="sc")
	Wraps a StateCollectionMessage in a ModuleMessage. More...

Private Attributes
std::multimap< StateVersion, StateMessage >	collectstate
	collect states container and its iterator More...

std::multimap< StateVersion, StateMessage >::iterator	it

PeerSet	m_AllPeers
	all known peers More...

unsigned int	m_countdone
	count number of "Done" messages More...

unsigned int	m_countmarker
	count number of marker More...

unsigned int	m_countstate
	count number of states More...

StateMessage	m_curstate
	current state More...

StateVersion	m_curversion
	current version of marker More...

std::vector< std::string >	m_device

std::string	m_module
	module that request state collection More...

bool	m_NotifyToSave
	flag to indicate save channel message More...

std::string	m_scleader
	save leader More...

Detailed Description

Description:: Declaration of Chandy-Lamport Algorithm Each node that wants to initiate the state collection records its local state and sends a marker message to all other peer nodes. Upon receiving a marker for the first time, peer nodes record their local states and start recording any message from incoming channel until receive marker from other nodes (these messages belong to the channel between the nodes).

Member Typedef Documentation

typedef std::pair< std::string, int > freedm::broker::sc::SCAgent::StateVersion

private

Constructor & Destructor Documentation

freedm::broker::sc::SCAgent::SCAgent ( )

SCAgent

Description:: : Constructor for the state collection module.

Precondition:: PoxisMain prepares parameters and invokes module.

Postcondition:: Object initialized and ready to enter run state.

Limitations:: : None

Member Function Documentation

CPeerNode freedm::broker::sc::SCAgent::AddPeer ( CPeerNode peer )

private

AddPeer

Description:: Add a peer to peer set from a pointer to a peer node object m_AllPeers is a specific peer set for SC module.

Precondition:: m_AllPeers

Postcondition:: Add a peer to m_AllPeers

Parameters

peer

Returns: a pointer to a peer node

CPeerNode IDGIModule::GetMe ( )

protectedinherited

GetMe

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

Returns: A CPeerNode referring to this process.

CPeerNode freedm::broker::sc::SCAgent::GetPeer ( std::string uuid )

private

GetPeer

Description:: Get a pointer to a peer from UUID. m_AllPeers is a specific peer set for SC module.

Precondition:: m_AllPeers

Postcondition:: Add a peer to m_AllPeers

Parameters

uuid string

Returns: a pointer to the peer

std::string IDGIModule::GetUUID ( ) const

protectedinherited

GetUUID

Description:: Gets this process's UUID.

Returns: This process's UUID

void freedm::broker::sc::SCAgent::HandleAccept ( CPeerNode peer )

private

This function will be called to handle Accept messages from LoadBalancing. Normally, state collection can safely ignore these messages, but if they arrive during state collection's own phase, then there is a problem and they need to be added to the collected state.

Parameters

peer	the DGI that sent the message

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

privatevirtual

"Downcasts" incoming messages into a specific message type, and passes the message to an appropriate handler.

Parameters

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

Implements freedm::broker::IDGIModule.

void freedm::broker::sc::SCAgent::HandleMarker	(	const MarkerMessage &	msg,
		CPeerNode	peer
	)

private

SCAgent::HandleMarker

Description:: This function will be called to handle marker message.

Key:: sc.marker

Precondition:: Messages are obtained.

Postcondition:: parsing marker messages based on different conditions.

Interaction Peers:: Invoked by dispatcher, other SC

Parameters

msg	the received message
peer	the node

void freedm::broker::sc::SCAgent::HandlePeerList	(	const gm::PeerListMessage &	msg,
		CPeerNode	peer
	)

private

SCAgent::HandlePeerList

Description:: This function will be called to handle PeerList message.

Key:: any.PeerList

Precondition:: Messages are obtained.

Postcondition:: parsing messages, reset to default state if receiving PeerList from different leader.

Interaction Peers:: Invoked by dispatcher, other SC

Parameters

msg	the received message
peer	the node

void freedm::broker::sc::SCAgent::HandleRequest	(	const RequestMessage &	msg,
		CPeerNode	peer
	)

private

SCAgent::HandleRequest

Description:: This function will be called to handle state collect request message.

Key:: sc.request

Precondition:: Messages are obtained.

Postcondition:: start state collection by calling Initiate().

Parameters

msg,peer

void freedm::broker::sc::SCAgent::HandleState	(	const StateMessage &	msg,
		CPeerNode	peer
	)

private

SCAgent::HandleState

Description:: This function will be called to handle state message.

Key:: sc.state

Precondition:: Messages are obtained.

Postcondition:: parsing messages based on state or in-transit channel message.

Interaction Peers:: Invoked by dispatcher, other SC

Parameters

msg	the received message
peer	the node

void freedm::broker::sc::SCAgent::Initiate ( )

private

Initiate

Description:: Initiator redcords its local state and broadcasts marker.

Precondition:: Receiving state collection request from other module.

Postcondition:: The node (initiator) starts collecting state by saving its own states and broadcasting a marker out.

Device I/O:: TakeSnapshot()

Returns: Send a marker out to all known peers

Citation:: Distributed Snapshots: Determining Global States of Distributed Systems, ACM Transactions on Computer Systems, Vol. 3, No. 1, 1985, pp. 63-75

ModuleMessage freedm::broker::sc::SCAgent::PrepareForSending	(	const StateCollectionMessage &	message,
		std::string	recipient = `"sc"`
	)

staticprivate

Wraps a StateCollectionMessage in a ModuleMessage.

Parameters

message	the message to prepare. If any required field is unset, the DGI will abort.
recipient	the module (sc/lb/gm/clk etc.) the message should be delivered to

Returns: a ModuleMessage containing a copy of the StateCollectionMessage

void freedm::broker::sc::SCAgent::SaveForward	(	StateVersion	latest,
		const MarkerMessage &	msg
	)

private

SaveForward

Description:: SaveForward is used by the node to save its local state and send marker out.

Precondition:: Marker message is received.

Postcondition:: The node saves its local state and sends marker out.

Parameters

latest	the current marker's version
msg	the message tp semd

void freedm::broker::sc::SCAgent::SendStateBack ( )

private

SendStateBack

Description:: SendStateBack is used by the peer to send collect states back to initiator.

Precondition:: Peer has completed its collecting states in local side.

Postcondition:: Peer sends its states back to the initiator.

Limitation:: Currently, only sending back gateway value and channel transit messages.

void freedm::broker::sc::SCAgent::StateResponse ( )

private

StateResponse

Description:: This function deals with the collectstate and prepare states sending back.

Precondition:: The initiator has collected all states.

Postcondition:: Collected states are sent back to the request module.

Interaction Peers:: other SC processes

Returns: Send message which contains gateway values and channel transit messages

Limitation:: Currently, only gateway values and channel transit messages are collected and sent back.

void freedm::broker::sc::SCAgent::TakeSnapshot ( const std::vector< std::string > & devicelist )

private

TakeSnapshot

Description:: TakeSnapshot is used to collect local states.

Precondition:: The initiator starts state collection or the peer receives marker at first time.

Postcondition:: Save local state in container m_curstate

Limitation:: Currently, it is used to collect only the gateway values for LB module

Member Data Documentation

std::multimap<StateVersion, StateMessage> freedm::broker::sc::SCAgent::collectstate

private

std::multimap<StateVersion, StateMessage>::iterator freedm::broker::sc::SCAgent::it

private

PeerSet freedm::broker::sc::SCAgent::m_AllPeers

private

unsigned int freedm::broker::sc::SCAgent::m_countdone

private

unsigned int freedm::broker::sc::SCAgent::m_countmarker

private

unsigned int freedm::broker::sc::SCAgent::m_countstate

private

StateMessage freedm::broker::sc::SCAgent::m_curstate

private

StateVersion freedm::broker::sc::SCAgent::m_curversion

private

std::vector<std::string> freedm::broker::sc::SCAgent::m_device

private

std::string freedm::broker::sc::SCAgent::m_module

private

bool freedm::broker::sc::SCAgent::m_NotifyToSave

private

std::string freedm::broker::sc::SCAgent::m_scleader

private

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

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

Public Member Functions

Protected Member Functions

Private Types

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation