uavcan::NodeInfoRetriever Class Reference

#include <node_info_retriever.hpp>

Inheritance diagram for uavcan::NodeInfoRetriever:

Classes
struct	Entry
struct	GenericHandlerCaller
struct	NodeInfoRetrievedHandlerCaller

Public Types
enum	{ MaxNumRequestAttempts = 254 }
enum	{ UnlimitedRequestAttempts = 0 }

Public Member Functions
int	addListener (INodeInfoListener *listener)
unsigned	getNumListeners () const
uint8_t	getNumPendingRequests () const
uint8_t	getNumRequestAttempts () const
MonotonicDuration	getRequestInterval () const
void	invalidateAll ()
bool	isRetrievingInProgress () const
	NodeInfoRetriever (INode &node)
void	removeListener (INodeInfoListener *listener)
void	setNumRequestAttempts (const uint8_t num)
void	setRequestInterval (const MonotonicDuration interval)
int	start (const TransferPriority priority=TransferPriority::OneHigherThanLowest)
Public Member Functions inherited from uavcan::NodeStatusMonitor
NodeID	findNodeWithWorstHealth () const
template<typename Operator >
void	forEachNode (Operator op) const
void	forgetAllNodes ()
void	forgetNode (NodeID node_id)
NodeStatus	getNodeStatus (NodeID node_id) const
bool	isNodeKnown (NodeID node_id) const
	NodeStatusMonitor (INode &node)
int	start ()
virtual	~NodeStatusMonitor ()

Private Types
enum	{ DefaultNumRequestAttempts = 16 }
enum	{ DefaultTimerIntervalMSec = 40 }
typedef MethodBinder< NodeInfoRetriever *, void(NodeInfoRetriever::*)(const ServiceCallResult< protocol::GetNodeInfo > &)>	GetNodeInfoResponseCallback

Private Member Functions
Entry &	getEntry (NodeID node_id)
const Entry &	getEntry (NodeID node_id) const
void	handleGetNodeInfoResponse (const ServiceCallResult< protocol::GetNodeInfo > &result)
virtual void	handleNodeStatusChange (const NodeStatusChangeEvent &event)
virtual void	handleNodeStatusMessage (const ReceivedDataStructure< protocol::NodeStatus > &msg)
virtual void	handleTimerEvent (const TimerEvent &)
NodeID	pickNextNodeToQuery (bool &out_at_least_one_request_needed) const
void	startTimerIfNotRunning ()
Private Member Functions inherited from uavcan::TimerBase
MonotonicTime	getDeadline () const
MonotonicDuration	getPeriod () const
Scheduler &	getScheduler () const
bool	isRunning () const
void	startOneShotWithDeadline (MonotonicTime deadline)
void	startOneShotWithDelay (MonotonicDuration delay)
void	startPeriodic (MonotonicDuration period)
void	stop ()
	TimerBase (INode &node)

Private Attributes
Entry	entries_ [NodeID::Max]
ServiceClient< protocol::GetNodeInfo, GetNodeInfoResponseCallback >	get_node_info_client_
uint8_t	last_picked_node_
Multiset< INodeInfoListener * >	listeners_
uint8_t	num_attempts_
MonotonicDuration	request_interval_

Additional Inherited Members

Detailed Description

This class automatically retrieves a response to GetNodeInfo once a node appears online or restarts. It does a number of attempts in case if there's a communication failure before assuming that the node does not implement the GetNodeInfo service. All parameters are pre-configured with sensible default values that should fit virtually any use case, but they can be overriden if needed - refer to the setter methods below for details.

Defaults are pre-configured so that the class is able to query 123 nodes (node ID 1..125, where 1 is our local node and 1 is one node that implements GetNodeInfo service, hence 123) of which none implements GetNodeInfo service in under 5 seconds. The 5 second limitation is imposed by UAVCAN-compatible bootloaders, which are unlikely to wait for more than that before continuing to boot. In case if this default value is not appropriate for the end application, the request interval can be overriden via setRequestInterval().

Following the above explained requirements, the default request interval is defined as follows: request interval [ms] = floor(5000 [ms] bootloader timeout / 123 nodes) Which yields 40 ms.

Given default service timeout 1000 ms and the defined above request frequency 40 ms, the maximum number of concurrent requests will be: max concurrent requests = ceil(1000 [ms] timeout / 40 [ms] request interval) Which yields 25 requests.

Keep the above equations in mind when changing the default request interval.

Obviously, if all calls are completing in under (request interval), the number of concurrent requests will never exceed one. This is actually the most likely scenario.

Note that all nodes are queried in a round-robin fashion, regardless of their uptime, number of requests made, etc.

Events from this class can be routed to many listeners, INodeInfoListener.

Definition at line 91 of file node_info_retriever.hpp.

Member Typedef Documentation

GetNodeInfoResponseCallback

typedef MethodBinder<NodeInfoRetriever*, void (NodeInfoRetriever::*)(const ServiceCallResult<protocol::GetNodeInfo>&)> uavcan::NodeInfoRetriever::GetNodeInfoResponseCallback

private

Definition at line 101 of file node_info_retriever.hpp.

Member Enumeration Documentation

anonymous enum

anonymous enum

Enumerator
MaxNumRequestAttempts

Definition at line 95 of file node_info_retriever.hpp.

anonymous enum

anonymous enum

Enumerator
UnlimitedRequestAttempts

Definition at line 96 of file node_info_retriever.hpp.

anonymous enum

anonymous enum

private

Enumerator
DefaultNumRequestAttempts

Definition at line 159 of file node_info_retriever.hpp.

anonymous enum

anonymous enum

private

Enumerator
DefaultTimerIntervalMSec

Definition at line 160 of file node_info_retriever.hpp.

Constructor & Destructor Documentation

NodeInfoRetriever()

uavcan::NodeInfoRetriever::NodeInfoRetriever ( INode &  node )

inline

Definition at line 332 of file node_info_retriever.hpp.

Member Function Documentation

addListener()

int uavcan::NodeInfoRetriever::addListener ( INodeInfoListener *  listener )

inline

Adds one listener. Does nothing if such listener already exists. May return -ErrMemory if there's no space to add the listener.

Definition at line 386 of file node_info_retriever.hpp.

getEntry() [1/2]

Entry& uavcan::NodeInfoRetriever::getEntry ( NodeID  node_id )

inlineprivate

Definition at line 181 of file node_info_retriever.hpp.

getEntry() [2/2]

const Entry& uavcan::NodeInfoRetriever::getEntry ( NodeID  node_id ) const

inlineprivate

Definition at line 180 of file node_info_retriever.hpp.

getNumListeners()

unsigned uavcan::NodeInfoRetriever::getNumListeners ( ) const

inline

Definition at line 415 of file node_info_retriever.hpp.

getNumPendingRequests()

uint8_t uavcan::NodeInfoRetriever::getNumPendingRequests ( ) const

inline

Definition at line 454 of file node_info_retriever.hpp.

getNumRequestAttempts()

uint8_t uavcan::NodeInfoRetriever::getNumRequestAttempts ( ) const

inline

Number of attempts to retrieve GetNodeInfo response before giving up on the assumption that the service is not implemented. Zero is a special value that can be used to set unlimited number of attempts, UnlimitedRequestAttempts.

Definition at line 422 of file node_info_retriever.hpp.

getRequestInterval()

MonotonicDuration uavcan::NodeInfoRetriever::getRequestInterval ( ) const

inline

Request interval also implicitly defines the maximum number of concurrent requests. Read the class documentation for details.

Definition at line 432 of file node_info_retriever.hpp.

handleGetNodeInfoResponse()

void uavcan::NodeInfoRetriever::handleGetNodeInfoResponse ( const ServiceCallResult< protocol::GetNodeInfo > &  result )

inlineprivate

Definition at line 301 of file node_info_retriever.hpp.

handleNodeStatusChange()

virtual void uavcan::NodeInfoRetriever::handleNodeStatusChange ( const NodeStatusChangeEvent &  event )

inlineprivatevirtual

Called when a node becomes online, changes status or goes offline. Refer to uavcan.protocol.NodeStatus for the offline timeout value. Overriding is not required.

Reimplemented from uavcan::NodeStatusMonitor.

Definition at line 256 of file node_info_retriever.hpp.

handleNodeStatusMessage()

virtual void uavcan::NodeInfoRetriever::handleNodeStatusMessage ( const ReceivedDataStructure< protocol::NodeStatus > &  msg )

inlineprivatevirtual

Called for every received message uavcan.protocol.NodeStatus after handleNodeStatusChange(), even if the status code did not change. Overriding is not required.

Reimplemented from uavcan::NodeStatusMonitor.

Definition at line 283 of file node_info_retriever.hpp.

handleTimerEvent()

virtual void uavcan::NodeInfoRetriever::handleTimerEvent ( const TimerEvent &  event )

inlineprivatevirtual

Implement this method in your class to receive callbacks.

Implements uavcan::TimerBase.

Definition at line 231 of file node_info_retriever.hpp.

invalidateAll()

void uavcan::NodeInfoRetriever::invalidateAll ( )

inline

This method forces the class to re-request uavcan.protocol.GetNodeInfo from all nodes as if they have just appeared in the network.

Definition at line 370 of file node_info_retriever.hpp.

isRetrievingInProgress()

bool uavcan::NodeInfoRetriever::isRetrievingInProgress ( ) const

inline

These methods are needed mostly for testing.

Definition at line 452 of file node_info_retriever.hpp.

pickNextNodeToQuery()

NodeID uavcan::NodeInfoRetriever::pickNextNodeToQuery ( bool &  out_at_least_one_request_needed ) const

inlineprivate

Definition at line 199 of file node_info_retriever.hpp.

removeListener()

void uavcan::NodeInfoRetriever::removeListener ( INodeInfoListener *  listener )

inline

Removes the listener. If the listener was not registered, nothing will be done.

Definition at line 403 of file node_info_retriever.hpp.

setNumRequestAttempts()

void uavcan::NodeInfoRetriever::setNumRequestAttempts ( const uint8_t  num )

inline

Definition at line 423 of file node_info_retriever.hpp.

setRequestInterval()

void uavcan::NodeInfoRetriever::setRequestInterval ( const MonotonicDuration  interval )

inline

Definition at line 433 of file node_info_retriever.hpp.

start()

int uavcan::NodeInfoRetriever::start ( const TransferPriority  priority = TransferPriority::OneHigherThanLowest )

inline

Starts the retriever. Destroy the object to stop it. Returns negative error code.

Definition at line 347 of file node_info_retriever.hpp.

startTimerIfNotRunning()

void uavcan::NodeInfoRetriever::startTimerIfNotRunning ( )

inlineprivate

Definition at line 190 of file node_info_retriever.hpp.

Member Data Documentation

entries_

Entry uavcan::NodeInfoRetriever::entries_[NodeID::Max]

private

Definition at line 165 of file node_info_retriever.hpp.

get_node_info_client_

ServiceClient<protocol::GetNodeInfo, GetNodeInfoResponseCallback> uavcan::NodeInfoRetriever::get_node_info_client_

private

Definition at line 169 of file node_info_retriever.hpp.

last_picked_node_

uint8_t uavcan::NodeInfoRetriever::last_picked_node_

mutableprivate

Definition at line 173 of file node_info_retriever.hpp.

listeners_

Multiset<INodeInfoListener*> uavcan::NodeInfoRetriever::listeners_

private

Definition at line 167 of file node_info_retriever.hpp.

num_attempts_

uint8_t uavcan::NodeInfoRetriever::num_attempts_

private

Definition at line 175 of file node_info_retriever.hpp.

request_interval_

MonotonicDuration uavcan::NodeInfoRetriever::request_interval_

private

Definition at line 171 of file node_info_retriever.hpp.

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

• node_info_retriever.hpp