faudes::nDevice Class Reference

#include <iop_simplenet.h>

Classes
struct	ClientState
struct	ServerState

Public Member Functions
	nDevice (void)
virtual	~nDevice (void)
virtual void	Clear (void)
void	ServerAddress (const std::string &rAddr)
void	BroadcastAddress (const std::string &rAddr)
void	NetworkName (const std::string &rNetwork)
void	InsNode (const std::string &rNodeName)
void	InsNodeAddress (const std::string &rNode, const std::string &rAddress)
void	ClearNodes (void)
void	InsInputEvent (const std::string &event)
void	InsOutputEvent (const std::string &event)
virtual void	Compile (void)
virtual void	Start (void)
virtual void	Stop (void)
virtual void	Reset (void)
virtual void	WriteOutput (Idx output)
Public Member Functions inherited from faudes::vDevice
	vDevice (void)
virtual	~vDevice (void)
void	Name (const std::string &rName)
const std::string &	Name (void) const
void	Tolerance (Time::Type maxgap)
Time::Type	Tolerance (void)
virtual void	TimeScale (unsigned int scale)
virtual int	TimeScale (void)
virtual void	Configure (Idx event, const AttributeDeviceEvent &attr)
virtual void	Configure (const EventSet &rPhysicalEvents)
virtual const EventSet &	Outputs (void) const
virtual const EventSet &	Inputs (void) const
virtual bool	ResetRequest (void)
virtual DeviceState	Status (void)
virtual std::string	StatusString (void)
virtual void	FlushOutputs (void)
virtual Idx	ReadInput (void)
virtual Idx	PeekInput (void)
virtual bool	InputReady (void)
virtual bool	WaitInputs (Time::Type duration)
virtual bool	WaitInputsMs (long int duration)
virtual Time::Type	CurrentTime (void)
virtual long int	CurrentTimeMs (void)
virtual void	CurrentTime (Time::Type now)
virtual void	CurrentTimeMs (long int nowms)
virtual faudes_systime_t	FtuToSystemTime (Time::Type duration)
void	UseCondition (faudes_mutex_t *wmutex, faudes_cond_t *wcond)
void	UseBuffer (faudes_mutex_t *bmutex, std::deque< Idx > *bbuffer)
virtual std::string	EStr (Idx ev)
SampledDensityFunction	Performance (void)
void	ResetPerformance (void)
void	WritePerformance (void)
Public Member Functions inherited from faudes::Type
	Type (void)
	Type (const Type &rType)
virtual	~Type (void)
virtual Type *	New (void) const
virtual Type *	Copy (void) const
virtual const Type *	Cast (const Type *pOther) const
virtual Type &	Assign (const Type &rSrc)
Type &	operator= (const Type &rSrc)
virtual bool	Equal (const Type &rOther) const
bool	operator== (const Type &rOther) const
bool	operator!= (const Type &rOther) const
virtual const std::string &	TypeName (void) const
void	Write (const Type *pContext=0) const
void	Write (const std::string &pFileName, const std::string &rLabel="", const Type *pContext=0, std::ios::openmode openmode=std::ios::out|std::ios::trunc) const
void	Write (const std::string &pFileName, std::ios::openmode openmode) const
void	Write (TokenWriter &rTw, const std::string &rLabel="", const Type *pContext=0) const
virtual void	XWrite (const std::string &pFileName, const std::string &rLabel="", const Type *pContext=0) const
void	XWrite (const Type *pContext=0) const
void	XWrite (TokenWriter &rTw, const std::string &rLabel="", const Type *pContext=0) const
std::string	ToString (const std::string &rLabel="", const Type *pContext=0) const
std::string	ToText (const std::string &rLabel="", const Type *pContext=0) const
void	DWrite (const Type *pContext=0) const
void	DWrite (const std::string &pFileName, const std::string &rLabel="", const Type *pContext=0, std::ios::openmode openmode=std::ios::out|std::ios::trunc) const
void	DWrite (TokenWriter &rTw, const std::string &rLabel="", const Type *pContext=0) const
void	SWrite (TokenWriter &rTw) const
void	SWrite (void) const
std::string	ToSText (void) const
void	Read (const std::string &rFileName, const std::string &rLabel="", const Type *pContext=0)
void	FromString (const std::string &rString, const std::string &rLabel="", const Type *pContext=0)
void	Read (TokenReader &rTr, const std::string &rLabel="", const Type *pContext=0)

Protected Member Functions
virtual void	DoReadPreface (TokenReader &rTr, const std::string &rLabel="", const Type *pContext=0)
virtual void	DoWritePreface (TokenWriter &rTw, const std::string &rLabel="", const Type *pContext=0) const
Protected Member Functions inherited from faudes::vDevice
virtual void	DoWrite (TokenWriter &rTw, const std::string &rLabel="", const Type *pContext=0) const
virtual void	DoWriteConfiguration (TokenWriter &rTw, const std::string &rLabel="", const Type *pContext=0) const
virtual void	DoRead (TokenReader &rTr, const std::string &rLabel="", const Type *pContext=0)
virtual void	DoReadConfiguration (TokenReader &rTr, const std::string &rLabel="", const Type *pContext=0)
virtual long int	FtuToMs (Time::Type faudes_time)
virtual Time::Type	MsToFtu (long int real_time)
Protected Member Functions inherited from faudes::Type
void	DoAssign (const Type &rSrc)
bool	DoEqual (const Type &rOther) const
virtual void	DoXWrite (TokenWriter &rTw, const std::string &rLabel="", const Type *pContext=0) const
virtual void	DoDWrite (TokenWriter &rTw, const std::string &rLabel="", const Type *pContext=0) const
virtual void	DoSWrite (TokenWriter &rTw) const
virtual const TypeDefinition *	TypeDefinitionp (void) const
virtual Token	XBeginTag (const std::string &rLabel="", const std::string &rFallbackLabel="") const

Protected Attributes
TaNameSet< AttributeSimplenetEvent > *	pConfiguration
std::string	mNetwork
SimplenetAddress	mListenAddress
SimplenetAddress	mBroadcastAddress
SimplenetAddress	mEffectiveListenAddress
std::map< std::string, std::string >	mNetworkNodes
std::map< std::string, EventSet >	mInputSubscriptions
faudes_mutex_t	mMutex
faudes_thread_t	mThreadListen
bool	mStopListen
int	mListenSocket
int	mBroadcastSocket
std::map< int, ClientState >	mOutputClientStates
std::map< std::string, ServerState >	mInputServerStates
Protected Attributes inherited from faudes::vDevice
std::string	mDefaultLabel
std::string	mName
EventSet *	mpConfiguration
EventSet	mInputs
EventSet	mOutputs
DeviceState	mState
faudes_mutex_t	mWaitMutex
faudes_cond_t	mWaitCondition
faudes_mutex_t *	pWaitMutex
faudes_cond_t *	pWaitCondition
faudes_systime_t	mTimeZero
int	mTimeScale
Time::Type	mMaxSyncGap
std::deque< Idx >	mInputBuffer
std::deque< Idx > *	pInputBuffer
faudes_mutex_t	mBufferMutex
faudes_mutex_t *	pBufferMutex
bool	mResetRequest
faudes_systime_t *	mpPerformanceWaitEnter
faudes_systime_t *	mpPerformanceWaitExit
int	mPerformanceEndIterator
int	mPerformanceBeginIterator

Friends
void *	NDeviceListen (void *)
void *	NDeviceServer (void *)
void *	NDeviceReply (void *)

Additional Inherited Members
Public Types inherited from faudes::vDevice
enum	DeviceState { Down , StartUp , Up , ShutDown }
Static Public Member Functions inherited from faudes::vDevice
static vDevice *	FromTokenReader (TokenReader &rTr)
static vDevice *	FromFile (const std::string &rFileName)
static void	StopAll (void)

Detailed Description

An nDevice implements networked IO via a simple TCP/IP protocol.

Networking

The purpose of this implementation of networked discrete events is to provide a basis for case studies. However, simple networked events via nDevice must not be confused with ongoing research that addresses synchronisation and real time behaviour. We take a really pragmatic approach here.

Our network is identified by its network name. It consists a number of nodes, each identified by its node name. In the current implementation, each node knows about the entire network ie knows about all other nodes. Each node plays two roles:

• the server role to send event notifications, and
• the client role to receive event notifications.

In their server role, each node is configured to listen on its server port for incomming TCP connections. When a client (i.e. some other node in client role) connects to the TCP port, the server replies to a simple command set in order to allow the client to subscribe to the nodes output events. When the application executes an output event on the node, this is notified to all connected clients and the clients will interpret the event as an input reading. Vice versa, the each node itself has the role of a client and subscribes to relevant output events served by other nodes in their server role.

Protocol Details

The protocol for commands and notification is libFAUDES-token based and can be inspected eg via nc or telnet; see the shell script in the tutorial. Event notifications are sent spontaneous to all connected clients in the format <Notify> Ev </Notify>. Commands are accepted in the format <Cmd> Command </Cmd> and will be answered accordingly.

Command via TCP	Reply
<Cmd> Info </Cmd>	configuration of node as token string (<SimplenetDevice name="SimpleMachine"> ... </SimplenetDevice> )
<Cmd> Status </Cmd>	acknowledgement with status string (<Ack> Up </Ack>, <Ack> StartUp </Ack> or <Ack> ShutDown </Ack>, respectively; will not connect/reply while Down)
<Cmd> ResetRequest </Cmd>	no acknowledgement
<Subscribe> Ev_1 ... Ev_N </Subscribe>	subset of available events (e.g. <Subscribed> Ev_2 Ev_7 Ev_9 </Subscribed>)

A minimal alternative implementation for a node consists of (1) a TCP server that ignores all incomming messages and issues event notifications to any relevant events; and, (2) a TCP client that subscribes to all events and then listens to event notifications. All other commands are optional and may change in future revisions of this protocol.

Name Resolution

On the technical side, each node needs to figure the IP addresses incl TCP ports on which the other nodes provide their service. To ease configuration, this information is distributed by UDP datagrams. In order to locate the other nodes within the network, a node may broadcasts a network request datagramm. Each node that receives such a request, replies with an advert datagramm to provide its address. Thus, the simple net nodes rely on some underlying name resolution by DNS services, but node configuration itself refers to simple-net node names only. Since each node knows about the names of all participating nodes, each node will know when all connections are up.

By default, UDP broadcasts are addressed to 255.255.255.255:40000. Since routers are not meant to pass-on broadcasts, nDevice name resolution is restricted to one subnet. If the local host is connected to multiple subnets, you need to specify the relevant subset explicitly by setting the appropriate broadcast address, e.g. 192.168.2.255:40000. To restrict networks to the local machine, set the broadcast address to the loopback device 127.0.0.1:40000. To span a network accross multiple subnets, server addresses can be explicitly specified as an attribute in the node configuration; e.g. <Node> name="SimpleSupervisor" address="192.168.2.1:40000"</Node>. This is also the preferred fallback when address resolution fails for other reasons.

Broadcast via UDP	Reply
<Request> network reqnode </Request>	advertisement of networkname, nodename and ip-address:port, e.g., <Advert> SimpleLoop SimpleSupervisor 192.168.2.1:40000 </Advert>

File IO

For token IO, the nDevice reads and writes a section with label
"SimplenetDevice". There are no relevant attributes yet. Simple machine example:

<SimplenetDevice name="SimpleMachine"> 
 
<!-- Time scale in ms/ftiu -->
<TimeScale value="1000"/> 
 
<!-- IP address of this node, incl. server TCP port -->
<ServerAddress value="localhost:40000"/> 
 
<!-- Broadcaset address for node resolution (optional)
<BroadcastAddress value="255.255.255.255:40000"/> 
 
<!-- Network topology -->
<Network name="SimpleLoop"> 
<Node name="SimpleMachine"/> 
<Node name="SimpleSupervisor"/> 
</Network> 
 
<!-- Event configuration -->
<EventConfiguration> 
<Event name="alpha" iotype="input"/> 
<Event name="beta" iotype="output"/> 
<Event name="mue" iotype="output"/> 
<Event name="lambda" iotype="input"/> 
</EventConfiguration> 
 
</SimplenetDevice> 

Implementation Notes

The current status of the code is premature; network io assumes reasonably large buffers; thread/select mechanism is inefficient; exception handling wont work; etc etc

Definition at line 431 of file iop_simplenet.h.

Constructor & Destructor Documentation

nDevice()

faudes::nDevice::nDevice

(

void

)

Default constructor

Definition at line 265 of file iop_simplenet.cpp.

~nDevice()

faudes::nDevice::~nDevice ( void  )

virtual

Explicit destructor.

Definition at line 283 of file iop_simplenet.cpp.

Member Function Documentation

BroadcastAddress()

void faudes::nDevice::BroadcastAddress

(

const std::string &

rAddr

)

Set broadcast address for address resolution Note: you can only set the broadcast address while the device is down.

Parameters

rAddr

Address for UDP broadcasts e.g. "255.255.255.255:40000"

Exceptions

Exception

No valid address (id 551) (NOT IMPLEMENTED)

Definition at line 308 of file iop_simplenet.cpp.

Clear()

void faudes::nDevice::Clear ( void  )

virtual

Clear all configuration. This implies Stop().

Reimplemented from faudes::vDevice.

Definition at line 292 of file iop_simplenet.cpp.

ClearNodes()

void faudes::nDevice::ClearNodes

(

void

)

Add a node to the network configuration. Note: you can only configure the network while the device is down.

Definition at line 333 of file iop_simplenet.cpp.

Compile()

void faudes::nDevice::Compile ( void  )

virtual

Set up internal data structures

Reimplemented from faudes::vDevice.

Definition at line 358 of file iop_simplenet.cpp.

DoReadPreface()

void faudes::nDevice::DoReadPreface ( TokenReader &  rTr, const std::string &  rLabel = "", const Type *  pContext = 0  )

protectedvirtual

Actual method to read device configuration from tokenreader.

This method calls the base class to read the device name and the the timescale. It then reads address, networkid and nodes. Overall device configuration is consists of DoReadPreface, DoReadConfiguration and Compile. It isimplemented in vDevice. The label and context parameters are ignored.

Parameters

rTr	TokenReader to read from
rLabel	Section to read
pContext	Read context to provide contextual information

Exceptions

Exception

IO error (id 1)

Reimplemented from faudes::vDevice.

Definition at line 399 of file iop_simplenet.cpp.

DoWritePreface()

void faudes::nDevice::DoWritePreface ( TokenWriter &  rTw, const std::string &  rLabel = "", const Type *  pContext = 0  ) const

protectedvirtual

Actual method to write the device configuration to a TokenWriter.

This method calls the base class vDevice to write the device name and the time scale. It then writes network related data. The label and context parameters are ignored.

Parameters

rTw	Reference to TokenWriter
rLabel	Label of section to write
pContext	Read context to provide contextual information

Exceptions

Exception

IO errors (id 2)

Reimplemented from faudes::vDevice.

Definition at line 367 of file iop_simplenet.cpp.

InsInputEvent()

void faudes::nDevice::InsInputEvent

(

const std::string &

event

)

Insert event as input event. Note: you can only configure events while the device is down.

Parameters

event

Event by name.

Definition at line 339 of file iop_simplenet.cpp.

InsNode()

void faudes::nDevice::InsNode

(

const std::string &

rNodeName

)

Add a node to the network configuration. Note: you can only configure the network while the device is down.

Parameters

rNodeName

Node to participate in wthe network.

Definition at line 321 of file iop_simplenet.cpp.

InsNodeAddress()

void faudes::nDevice::InsNodeAddress	(	const std::string &	rNode,
		const std::string &	rAddress
	)

Add entry to node name resolution

Note: you can only configure the network while the device is down.

Parameters

rNode	Name of node to register
rAddress	Address incl port

Definition at line 327 of file iop_simplenet.cpp.

InsOutputEvent()

void faudes::nDevice::InsOutputEvent

(

const std::string &

event

)

Insert event as output event. Note: you can only configure event while the device is down.

Parameters

event

Event by name.

Definition at line 348 of file iop_simplenet.cpp.

NetworkName()

void faudes::nDevice::NetworkName

(

const std::string &

rNetwork

)

Set network name to participate. Note: you can only set the network name while the device is down.

Parameters

rNetwork

Name of network, e.g. "ElevatorNetwork"

Definition at line 315 of file iop_simplenet.cpp.

Reset()

void faudes::nDevice::Reset ( void  )

virtual

Reset device. Resets buffered input events and current time.

Reimplemented from faudes::vDevice.

Definition at line 1280 of file iop_simplenet.cpp.

ServerAddress()

void faudes::nDevice::ServerAddress

(

const std::string &

rAddr

)

Set server address of this node. Note: you can only set th server address while the device is down.

Parameters

rAddr

Address on which to run this server, e.g. "localhost:40000"

Exceptions

Exception

No valid address (id 551) (NOT IMPLEMENTED)

Definition at line 302 of file iop_simplenet.cpp.

Start()

void faudes::nDevice::Start ( void  )

virtual

Activate the device. This function enables output execution and input reading. It starts the background thread for incomming connections and tries to connect to relevant servers.

Exceptions

Exception

Not yet configured (id 551) Fatal network error (id 553) Fatal thread error (id 554)

Reimplemented from faudes::vDevice.

Definition at line 541 of file iop_simplenet.cpp.

Stop()

void faudes::nDevice::Stop ( void  )

virtual

Deactivate the device. This function disables output execution and input reading. It stops the backhround thread to provide connections and disconnects from any servers.

Reimplemented from faudes::vDevice.

Definition at line 639 of file iop_simplenet.cpp.

WriteOutput()

void faudes::nDevice::WriteOutput ( Idx  output )

virtual

Run output command.

Exceptions

Exception

unknown output event (id 65)

Implements faudes::vDevice.

Definition at line 490 of file iop_simplenet.cpp.

Friends And Related Function Documentation

NDeviceListen

void* NDeviceListen ( void *  )

friend

Definition at line 682 of file iop_simplenet.cpp.

NDeviceReply

void* NDeviceReply ( void *  )

friend

NDeviceServer

void* NDeviceServer ( void *  )

friend

Member Data Documentation

mBroadcastAddress

SimplenetAddress faudes::nDevice::mBroadcastAddress

protected

Simplenet: address for udp broadcast (255.255.255.255:40000

Definition at line 636 of file iop_simplenet.h.

mBroadcastSocket

int faudes::nDevice::mBroadcastSocket

protected

Background: udp broadcast socket (background only)

Definition at line 660 of file iop_simplenet.h.

mEffectiveListenAddress

SimplenetAddress faudes::nDevice::mEffectiveListenAddress

protected

Simplenet: effective address of my server port

Definition at line 639 of file iop_simplenet.h.

mInputServerStates

std::map<std::string,ServerState> faudes::nDevice::mInputServerStates

protected

Background: connection states to event servers (by node name)

Definition at line 683 of file iop_simplenet.h.

mInputSubscriptions

std::map<std::string,EventSet> faudes::nDevice::mInputSubscriptions

protected

Compiled data: map subscriptions

Definition at line 645 of file iop_simplenet.h.

mListenAddress

SimplenetAddress faudes::nDevice::mListenAddress

protected

Simplenet: address of my server incl port (localhost:40000)

Definition at line 633 of file iop_simplenet.h.

mListenSocket

int faudes::nDevice::mListenSocket

protected

Background: server socket to listen (background only)

Definition at line 657 of file iop_simplenet.h.

mMutex

faudes_mutex_t faudes::nDevice::mMutex

protected

Background: mutex for below shared variables

Definition at line 648 of file iop_simplenet.h.

mNetwork

std::string faudes::nDevice::mNetwork

protected

Simplenet: network id

Definition at line 630 of file iop_simplenet.h.

mNetworkNodes

std::map<std::string,std::string> faudes::nDevice::mNetworkNodes

protected

Simplenet: list of nodes in this network incl default addresses

Definition at line 642 of file iop_simplenet.h.

mOutputClientStates

std::map<int, ClientState> faudes::nDevice::mOutputClientStates

protected

Background: map sockets to connection states (shared)

Definition at line 671 of file iop_simplenet.h.

mStopListen

bool faudes::nDevice::mStopListen

protected

Background: request to join via flag (mutexed)

Definition at line 654 of file iop_simplenet.h.

mThreadListen

faudes_thread_t faudes::nDevice::mThreadListen

protected

Background: thread handle (global)

Definition at line 651 of file iop_simplenet.h.

pConfiguration

TaNameSet<AttributeSimplenetEvent>* faudes::nDevice::pConfiguration

protected

Overall configuration (with actual type)

Definition at line 627 of file iop_simplenet.h.

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

• iop_simplenet.h
• iop_simplenet.cpp