CODEX_Quorum::StaticByzantineQuorumSystem< N, T > Class Template Reference

A compile-time configured Byzantine quorum system. More...

#include <StaticByzantineQuorumSystem.h>

Inheritance diagram for CODEX_Quorum::StaticByzantineQuorumSystem< N, T >:

[legend]Collaboration diagram for CODEX_Quorum::StaticByzantineQuorumSystem< N, T >:

[legend]List of all members.

Public Member Functions
	StaticByzantineQuorumSystem (ResponseTracker *aRT)
	Constructor.
virtual	~StaticByzantineQuorumSystem ()
	Destructor. This clears out any remaining message buffers.
unsigned int	quorumSystemSize ()
unsigned int	quorumSize ()
unsigned int	faultsTolerated ()
bool	broadcastMessage (const Message &msg, ReturnVector &rets, ResponseCallback *cb)
	Send a message to all the servers in a QuorumSystem.
bool	unicastMessage (const MessageVector &msgs, ReturnVector &rets, ResponseCallback *cb=0)
	Send a server-specific message to each server in a QuorumSystem.
void	poll (MessageDispatcher &requestDispatcher, QuorumDispatcher &responseDispatcher)
void	setServer (unsigned int i, RemoteServer *server)
	Set a pointer to a RemoteServer for server slot i.
const RemoteServer *	server (unsigned int i) const
	A pointer to the RemoteServer for server slot i.
virtual unsigned char *	extractKey (const unsigned char *data)
	Forwards a request to ResponseTracker::extractKey().
virtual bool	keyRegistered (const unsigned char *key)
	Determines whether a key is registered with the ResponseTracker.
Protected Attributes
ResponseTracker *	m_responseTracker
	This is used to match responses to their associated requests.

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Detailed Description

template<int N, int T>
class CODEX_Quorum::StaticByzantineQuorumSystem< N, T >

A compile-time configured Byzantine quorum system.

Template parameters that must be supplied are the number of servers in the quorum system and the number of faults tolerated.

Definition at line 42 of file StaticByzantineQuorumSystem.h.

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Member Function Documentation

template<int N, int T> bool CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::broadcastMessage (  const Message &  msg, ReturnVector &  rets, ResponseCallback *  cb )  [virtual]

Send a message to all the servers in a QuorumSystem. This method only sends messages. It expects the vector rets to be initialized before calling. Repeated calls can be made until sufficient servers have been contacted. The subclass implementation should check the current values of rets before making connections. The message sent is also registered with the ResponseTracker, since broadcasts are generally requests awaiting replies. This can be prevented by passing a 0 callback. It is advisable in cases where the sender is part of the quorum system for there to be distinct outgoing and incoming server identifiers. For example, the first bit of the first byte might flag whether this is a request being sent by the server or a response to a request from the server. This prevents the request from being treated as a response to itself in ResponseTracker. All messages should have identifying information for the initiator of the request and a unique ID for the request. Parameters: msg  A message to broadcast to the QuorumSystem. rets  Vector of RemoteServerReturn%s to the message. cb  If not 0, the request is added to the ResponseTracker using cb as its message callback. This should only be done once for any given request. Returns: true if the broadcast was successfully sent to all servers. Implements CODEX_Quorum::QuorumSystem. Definition at line 161 of file StaticByzantineQuorumSystem.h. References CODEX_Quorum::QuorumSystem::extractKey(), CODEX_Quorum::ResponseTracker::insert(), CODEX_Quorum::ResponseInfo::map(), and CODEX_Quorum::RemoteServer::sendTo().

template<int N, int T> unsigned int CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::faultsTolerated (   )  [virtual]

Returns: The number of faults tolerated by this QuorumSystem. Implements CODEX_Quorum::QuorumSystem. Definition at line 154 of file StaticByzantineQuorumSystem.h. Referenced by CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::poll().

virtual bool CODEX_Quorum::QuorumSystem::keyRegistered (  const unsigned char *  key  )  [inline, virtual, inherited]

Determines whether a key is registered with the ResponseTracker. Returns: Whether the key passed in is registered. Definition at line 207 of file QuorumSystem.h. References CODEX_Quorum::QuorumSystem::m_responseTracker. Referenced by CODEX_Server::UnicastRequestHandler::handler(), and CODEX_Server::BroadcastRequestHandler::handler().

template<int N, int T> void CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::poll (  MessageDispatcher &  requestDispatcher, QuorumDispatcher &  responseDispatcher )  [virtual]

Bug: The wrong exception is thrown after a failed select(2). Bug: Something should probably be done when testing error_set returns true. Implements CODEX_Quorum::QuorumSystem. Definition at line 363 of file StaticByzantineQuorumSystem.h. References CODEX_Quorum::Message::buffer(), CODEX_Quorum::ResponseTracker::check(), CODEX_Quorum::QuorumSystem::extractKey(), CODEX_Quorum::ResponseInfo::failures(), CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::faultsTolerated(), CODEX_Quorum::RemoteServer::isset_fd(), CODEX_Quorum::Message::length(), CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::quorumSize(), CODEX_Quorum::RemoteServer::receiveFrom(), CODEX_Quorum::ResponseTracker::remove(), CODEX_Quorum::RemoteServer::set_fd(), and CODEX_Quorum::ResponseInfo::successes().

template<int N, int T> unsigned int CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::quorumSize (   )  [virtual]

Returns: The size of a quorum for this QuorumSystem. Implements CODEX_Quorum::QuorumSystem. Definition at line 146 of file StaticByzantineQuorumSystem.h. Referenced by CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::poll().

template<int N, int T> unsigned int CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::quorumSystemSize (   )  [virtual]

Returns: The number of servers in this QuorumSystem. Implements CODEX_Quorum::QuorumSystem. Definition at line 139 of file StaticByzantineQuorumSystem.h.

template<int N, int T> void CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::setServer (  unsigned int  i, RemoteServer *  server )

Set a pointer to a RemoteServer for server slot i. The StaticByzantineQuorumSystem takes ownership of the memory. Cleanup can be avoided by setting the server to 0 before destroying the object. Definition at line 494 of file StaticByzantineQuorumSystem.h. References CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::server(). Referenced by CODEX_Server::ServerState::addQuorumServer().

template<int N, int T> bool CODEX_Quorum::StaticByzantineQuorumSystem< N, T >::unicastMessage (  const MessageVector &  msgs, ReturnVector &  rets, ResponseCallback *  cb = 0 )  [virtual]

Send a server-specific message to each server in a QuorumSystem. This method only sends messages. It expects the vector rets to be initialized before calling. Repeated calls can be made until sufficient servers have been contacted. The subclass implementation should check the current values of rets before making connections. By default, the message sent is not registered with the ResponseTracker, since unicasts are not generally requests awaiting replies. This behavior can be changed by passing a callback object. It is advisable in cases where the sender is part of the quorum system for there to be distinct outgoing and incoming server identifiers. For example, the first bit of the first byte might flag whether this is a request being sent by the server or a response to a request from the server. This prevents the request from being treated as a response to itself in ResponseTracker. Parameters: msgs  A set of messages to unicast to the servers in the QuorumSystem. rets  Vector of RemoteServerReturn%s to the messages. cb  If not 0, the request is added to the ResponseTracker using cb as its message callback. This should only be done once for any given request. Returns: true if the unicasts were successfully sent to all servers. Implements CODEX_Quorum::QuorumSystem. Definition at line 252 of file StaticByzantineQuorumSystem.h. References CODEX_Quorum::QuorumSystem::extractKey(), CODEX_Quorum::ResponseTracker::insert(), CODEX_Quorum::ResponseInfo::map(), and CODEX_Quorum::RemoteServer::sendTo().

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

• StaticByzantineQuorumSystem.h

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