qOS::sm::signalPublisher Class Reference

An object to subscribe FSM(Finite State Machine) objects to specific user-defined signals. More...

#include <fsm.hpp>

Public Member Functions
	signalPublisher ()
bool	subscribeToSignal (stateMachine &m, sm::signalID s) noexcept
	Subscribe state machine to a particular signal.
bool	subscribeToSignal (stateMachine &m, sm::signalIDType s) noexcept
bool	unsubscribeFromSignal (stateMachine &m, sm::signalID s) noexcept
	Unsubscribe state machine from a particular signal.
bool	unsubscribeFromSignal (stateMachine &m, sm::signalIDType s) noexcept
bool	sendSignal (sm::signalID sig, void *sData=nullptr, bool isUrgent=false) noexcept
	Sends a signal to all its subscribers.
bool	sendSignal (sm::signalIDType sig, void *sData=nullptr, bool isUrgent=false) noexcept

Detailed Description

An object to subscribe FSM(Finite State Machine) objects to specific user-defined signals.

This object provides a mechanism to decouple signal producers from the signal consumers, so state-machine objects interested in certain signals subscribe to one or more Signals".

Constructor & Destructor Documentation

signalPublisher()

qOS::sm::signalPublisher::signalPublisher

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Member Function Documentation

sendSignal() [1/2]

bool qOS::sm::signalPublisher::sendSignal ( sm::signalID sig, void * sData = nullptr, bool isUrgent = false )

noexcept

Sends a signal to all its subscribers.

Note

If the signal queue is not available, an exclusion variable will be used.This means that the signal cannot be sent until the variable is empty. (the signal was handled by the state-machine engine).

Remarks

To enable the functionality of sending signals to subscribers, you must set the macros Q_FSM_PS_SIGNALS_MAX and Q_FSM_PS_SUB_PER_SIGNAL_MAX in the configuration file config.h

Warning

Data associated to the signal is not deep-copied to a queue or any buffer. It's only data pointer (address in memory) that is shallow-copied to a signal queue so it has to point to a globally accessible memory. If it pointed to a sender's local variable (from the stack) it would be invalid after sender returns from the function that sends the signal.

Note

The signal-queue event has the highest precedence.

Parameters

[in]	sig	The user-defined signal.
[in]	sData	The data associated to the signal.
[in]	isUrgent	If true, the signal will be sent to the front of the queue. (only if the there is a signal-queue available)

Returns

true if the provided signal was successfully delivered to the subscribers (if available), otherwise return false. false if there is a queue, and the signal cannot be inserted because it is full.

sendSignal() [2/2]

bool qOS::sm::signalPublisher::sendSignal ( sm::signalIDType sig, void * sData = nullptr, bool isUrgent = false )

inlinenoexcept

subscribeToSignal() [1/2]

bool qOS::sm::signalPublisher::subscribeToSignal ( stateMachine & m, sm::signalID s )

noexcept

Subscribe state machine to a particular signal.

Parameters

[in]	m	State-machine to be subscribed
[in]	s	Signal ID to which the subscriber FSM wants to subscribe.

Returns

Returns true on success, otherwise returns false.

subscribeToSignal() [2/2]

bool qOS::sm::signalPublisher::subscribeToSignal ( stateMachine & m, sm::signalIDType s )

inlinenoexcept

unsubscribeFromSignal() [1/2]

bool qOS::sm::signalPublisher::unsubscribeFromSignal ( stateMachine & m, sm::signalID s )

noexcept

Unsubscribe state machine from a particular signal.

Parameters

[in]	m	State-machine to be subscribed
[in]	s	Signal ID to which the subscriber FSM wants to unsubscribe.

Returns

Returns true on success, otherwise returns false.

unsubscribeFromSignal() [2/2]

bool qOS::sm::signalPublisher::unsubscribeFromSignal ( stateMachine & m, sm::signalIDType s )

inlinenoexcept