yasmin::StateMachine Class Reference

A class that implements a state machine with a set of states, transitions, and callback mechanisms for state changes. More...

#include <state_machine.hpp>

Inheritance diagram for yasmin::StateMachine:

Collaboration diagram for yasmin::StateMachine:

Public Member Functions
	StateMachine (std::set< std::string > outcomes)
	Construct a new StateMachine object.
void	add_state (std::string name, std::shared_ptr< State > state, std::map< std::string, std::string > transitions)
	Adds a state to the state machine with specified transitions.
void	add_state (std::string name, std::shared_ptr< State > state)
	Adds a state to the state machine without transitions.
void	set_start_state (std::string state_name)
	Sets the start state for the state machine.
std::string	get_start_state ()
	Retrieves the name of the start state.
std::map< std::string, std::shared_ptr< State > > const &	get_states ()
	Gets a constant reference to the map of states.
std::map< std::string, std::map< std::string, std::string > > const &	get_transitions ()
	Gets a constant reference to the map of transitions.
std::string	get_current_state ()
	Retrieves the current state name.
void	add_start_cb (StartCallbackType cb, std::vector< std::string > args={})
	Adds a callback function to be called when the state machine starts.
void	add_transition_cb (TransitionCallbackType cb, std::vector< std::string > args={})
	Adds a callback function for state transitions.
void	add_end_cb (EndCallbackType cb, std::vector< std::string > args={})
	Adds a callback function to be called when the state machine ends.
void	call_start_cbs (std::shared_ptr< yasmin::blackboard::Blackboard > blackboard, const std::string &start_state)
	Calls start callbacks with the given blackboard and start state.
void	call_transition_cbs (std::shared_ptr< yasmin::blackboard::Blackboard > blackboard, const std::string &from_state, const std::string &to_state, const std::string &outcome)
	Calls transition callbacks when transitioning between states.
void	call_end_cbs (std::shared_ptr< yasmin::blackboard::Blackboard > blackboard, const std::string &outcome)
	Calls end callbacks with the given blackboard and outcome.
void	validate (bool strict_mode=false)
	Validates the state machine configuration.
std::string	execute (std::shared_ptr< blackboard::Blackboard > blackboard) override
	Executes the state machine.
std::string	execute ()
	Executes the state machine using a default blackboard.
std::string	operator() ()
	Invokes the state machine using a default blackboard.
void	cancel_state () override
	Cancels the current state execution.
std::string	to_string ()
	Converts the state machine to a string representation.
Public Member Functions inherited from yasmin::State
	State (std::set< std::string > outcomes)
	Constructs a State with a set of possible outcomes.
std::string	operator() (std::shared_ptr< blackboard::Blackboard > blackboard)
	Executes the state and returns the outcome.
bool	is_canceled () const
	Checks if the state has been canceled.
bool	is_running () const
	Checks if the state is currently running.
std::set< std::string > const &	get_outcomes ()
	Gets the set of possible outcomes for this state.

Private Types
using	StartCallbackType
	Alias for a callback function executed before running the state machine.
using	TransitionCallbackType
	Alias for a callback function executed before changing the state.
using	EndCallbackType
	Alias for a callback function executed after running the state machine.

Private Attributes
std::map< std::string, std::shared_ptr< State > >	states
	Map of states.
std::map< std::string, std::map< std::string, std::string > >	transitions
	Map of transitions.
std::string	start_state
	Name of the start state.
std::string	current_state
	Name of the current state.
std::unique_ptr< std::mutex >	current_state_mutex
	Mutex for current state access.
std::atomic_bool	validated {false}
	Flag to indicate if the state machine has been validated.
std::vector< std::pair< StartCallbackType, std::vector< std::string > > >	start_cbs
	Start callbacks executed before the state machine.
std::vector< std::pair< TransitionCallbackType, std::vector< std::string > > >	transition_cbs
	Transition callbacks executed before changing the state.
std::vector< std::pair< EndCallbackType, std::vector< std::string > > >	end_cbs
	End callbacks executed before the state machine.

Additional Inherited Members
Protected Attributes inherited from yasmin::State
std::set< std::string >	outcomes
	The possible outcomes of this state.

Detailed Description

A class that implements a state machine with a set of states, transitions, and callback mechanisms for state changes.

The StateMachine class inherits from the State class and allows the registration of states with their respective transitions and callbacks for start, transition, and end events.

Member Typedef Documentation

EndCallbackType

using yasmin::StateMachine::EndCallbackType

private

Initial value:

 std::function<void(
      std::shared_ptr<yasmin::blackboard::Blackboard>, const std::string &,
      const std::vector<std::string> &)>

Alias for a callback function executed after running the state machine.

StartCallbackType

using yasmin::StateMachine::StartCallbackType

private

Initial value:

 std::function<void(
      std::shared_ptr<yasmin::blackboard::Blackboard>, const std::string &,
      const std::vector<std::string> &)>

Alias for a callback function executed before running the state machine.

TransitionCallbackType

using yasmin::StateMachine::TransitionCallbackType

private

Initial value:

 std::function<void(
      std::shared_ptr<yasmin::blackboard::Blackboard>, const std::string &,
      const std::string &, const std::string &,
      const std::vector<std::string> &)>

Alias for a callback function executed before changing the state.

Constructor & Destructor Documentation

StateMachine()

StateMachine::StateMachine

(

std::set< std::string >

outcomes

)

Construct a new StateMachine object.

Parameters

outcomes

A set of possible outcomes for the state machine.

Member Function Documentation

add_end_cb()

void StateMachine::add_end_cb	(	EndCallbackType	cb,
		std::vector< std::string >	args = {} )

Adds a callback function to be called when the state machine ends.

Parameters

cb	The callback function to execute.
args	Optional arguments to pass to the callback.

add_start_cb()

void StateMachine::add_start_cb	(	StartCallbackType	cb,
		std::vector< std::string >	args = {} )

Adds a callback function to be called when the state machine starts.

Parameters

cb	The callback function to execute.
args	Optional arguments to pass to the callback.

add_state() [1/2]

void StateMachine::add_state	(	std::string	name,
		std::shared_ptr< State >	state )

Adds a state to the state machine without transitions.

Parameters

name	The name of the state.
state	A shared pointer to the State object representing the new state.

add_state() [2/2]

void StateMachine::add_state	(	std::string	name,
		std::shared_ptr< State >	state,
		std::map< std::string, std::string >	transitions )

Adds a state to the state machine with specified transitions.

Parameters

name	The name of the state.
state	A shared pointer to the State object representing the new state.
transitions	A map of transitions where the key is the outcome and the value is the target state name.

Exceptions

std::logic_error	If the state is already registered or is an outcome.
std::invalid_argument	If any transition has empty source or target, or references unregistered outcomes.

add_transition_cb()

void StateMachine::add_transition_cb	(	TransitionCallbackType	cb,
		std::vector< std::string >	args = {} )

Adds a callback function for state transitions.

Parameters

cb	The callback function to execute.
args	Optional arguments to pass to the callback.

call_end_cbs()

void StateMachine::call_end_cbs	(	std::shared_ptr< yasmin::blackboard::Blackboard >	blackboard,
		const std::string &	outcome )

Calls end callbacks with the given blackboard and outcome.

Parameters

blackboard	A shared pointer to the blackboard.
outcome	The outcome when the state machine ends.

call_start_cbs()

void StateMachine::call_start_cbs	(	std::shared_ptr< yasmin::blackboard::Blackboard >	blackboard,
		const std::string &	start_state )

Calls start callbacks with the given blackboard and start state.

Parameters

blackboard	A shared pointer to the blackboard.
start_state	The name of the start state.

call_transition_cbs()

void StateMachine::call_transition_cbs	(	std::shared_ptr< yasmin::blackboard::Blackboard >	blackboard,
		const std::string &	from_state,
		const std::string &	to_state,
		const std::string &	outcome )

Calls transition callbacks when transitioning between states.

Parameters

blackboard	A shared pointer to the blackboard.
from_state	The state being transitioned from.
to_state	The state being transitioned to.
outcome	The outcome that triggered the transition.

cancel_state()

void StateMachine::cancel_state ( )

overridevirtual

Cancels the current state execution.

Reimplemented from yasmin::State.

execute() [1/2]

std::string StateMachine::execute

(

)

Executes the state machine using a default blackboard.

Returns

The outcome of the state machine execution.

execute() [2/2]

std::string StateMachine::execute ( std::shared_ptr< blackboard::Blackboard > blackboard )

overridevirtual

Executes the state machine.

Parameters

blackboard

A shared pointer to the blackboard used during execution.

Returns

The outcome of the state machine execution.

Exceptions

std::runtime_error

If the execution cannot be completed due to invalid states or transitions.

Reimplemented from yasmin::State.

get_current_state()

std::string StateMachine::get_current_state

(

)

Retrieves the current state name.

Returns

The name of the current state.

get_start_state()

std::string StateMachine::get_start_state

(

)

Retrieves the name of the start state.

Returns

The name of the start state.

get_states()

std::map< std::string, std::shared_ptr< State > > const & StateMachine::get_states

(

)

Gets a constant reference to the map of states.

Returns

A constant reference to the map of states.

get_transitions()

std::map< std::string, std::map< std::string, std::string > > const & StateMachine::get_transitions

(

)

Gets a constant reference to the map of transitions.

Returns

A constant reference to the map of transitions.

operator()()

std::string StateMachine::operator()

(

)

Invokes the state machine using a default blackboard.

Returns

The outcome of the state machine execution.

set_start_state()

void StateMachine::set_start_state

(

std::string

state_name

)

Sets the start state for the state machine.

Parameters

state_name

The name of the state to set as the start state.

Exceptions

std::invalid_argument

If the state name is empty or not registered.

to_string()

std::string StateMachine::to_string ( )

virtual

Converts the state machine to a string representation.

Returns

A string describing the state machine and its states.

Reimplemented from yasmin::State.

validate()

void StateMachine::validate

(

bool

strict_mode = false

)

Validates the state machine configuration.

Parameters

strict

Whether the validation is strict, which means checking if all state outcomes are used and all state machine outcomes are reached.

Exceptions

std::runtime_error

If the state machine is misconfigured.

Member Data Documentation

current_state

std::string yasmin::StateMachine::current_state

private

Name of the current state.

current_state_mutex

std::unique_ptr<std::mutex> yasmin::StateMachine::current_state_mutex

private

Mutex for current state access.

end_cbs

std::vector<std::pair<EndCallbackType, std::vector<std::string> > > yasmin::StateMachine::end_cbs

private

End callbacks executed before the state machine.

start_cbs

std::vector<std::pair<StartCallbackType, std::vector<std::string> > > yasmin::StateMachine::start_cbs

private

Start callbacks executed before the state machine.

start_state

std::string yasmin::StateMachine::start_state

private

Name of the start state.

states

std::map<std::string, std::shared_ptr<State> > yasmin::StateMachine::states

private

Map of states.

transition_cbs

std::vector<std::pair<TransitionCallbackType, std::vector<std::string> > > yasmin::StateMachine::transition_cbs

private

Transition callbacks executed before changing the state.

transitions

std::map<std::string, std::map<std::string, std::string> > yasmin::StateMachine::transitions

private

Map of transitions.

validated

std::atomic_bool yasmin::StateMachine::validated {false}

private

Flag to indicate if the state machine has been validated.

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

• yasmin/include/yasmin/state_machine.hpp
• yasmin/src/yasmin/state_machine.cpp