Subscriptions

Description

Subscribing to resources to read their values.

Event model

The event model allows even remote hosts to securely catch all events reported by the driver. This is important, if a sensor (e.g. a push button) may change its value very quickly, but event quick changes need to be processed. If this property cannot be guaranteed (e.g. because a host is temporarily down or the network connection lost), evens of type 'retDisconnected' and hopefully later 'retConnected' are dispatched, so that the subscriber is informed about this situation.

Collaboration diagram for Subscriptions:

Classes
class	CRcEvent
	Events delivered by a subscriber or to a driver. More...
class	CRcEventProcessor
	Event processor. More...
class	CRcEventTimer
	Timer that sends 'rceTimer' events over the event system. More...
class	CRcSubscriber
	Subscriber to follow an arbitrary set of resources. More...

Typedefs
typedef bool	FRcEventFunc(class CRcEventProcessor *, CRcEvent *, void *)
	Event processor callback function. Example: bool OnEventFunc (CRcEventProcessor *ep, CRcEvent *ev, void *data);

Enumerations
enum	ERcEventType {   rceNone = 0 , rceTimer , rceValueStateChanged , rceRequestChanged ,   rceDisconnected , rceConnected , rceDriveValue }
	Event type. More...

Enumeration Type Documentation

ERcEventType

enum ERcEventType

Event type.

Enumerator
rceNone	None (for dummy events)
rceTimer	[timer] Timer alarm
rceValueStateChanged	[subscriber] Value or state has changed
rceRequestChanged	[subscriber] Request has changed
rceDisconnected	[subscriber] Connection to resource was lost
rceConnected	[subscriber] Connection to resource is (re-)established
rceDriveValue	[driver] Drive a new value

Definition at line 1561 of file resources.H.