Class to handle asynchronous function calls. AsyncFunctionHandler is a class that allows the user to have a asynchronous call to the parsed method and be able to set some thread specific parameters. More...

#include <async_function_handler.hpp>

Public Member Functions
void	init (std::function< T(const rclcpp::Time &, const rclcpp::Duration &)> callback, int thread_priority=50)
	Initialize the AsyncFunctionHandler with the callback and thread_priority.

void	init (std::function< T(const rclcpp::Time &, const rclcpp::Duration &)> callback, std::function< bool()> trigger_predicate, int thread_priority=50)
	Initialize the AsyncFunctionHandler with the callback, trigger_predicate and thread_priority.

void	init (std::function< T(const rclcpp::Time &, const rclcpp::Duration &)> callback, const AsyncFunctionHandlerParams &params)

std::pair< bool, T >	trigger_async_callback (const rclcpp::Time &time, const rclcpp::Duration &period)
	Triggers the async callback method cycle.

T	get_last_return_value () const
	Get the last return value of the async callback method.

const rclcpp::Time &	get_current_callback_time () const
	Get the current callback time.

const rclcpp::Duration &	get_current_callback_period () const
	Get the current callback period.

void	reset_variables ()
	Resets the internal variables of the AsyncFunctionHandler.

bool	wait_for_trigger_cycle_to_finish ()
	Waits until the current async callback method trigger cycle is finished.

bool	pause_execution ()
	Pauses the execution of the async callback thread.

bool	is_initialized () const
	Check if the AsyncFunctionHandler is initialized.

void	join_async_callback_thread ()
	Join the async callback thread.

bool	is_running () const
	Check if the async worker thread is running.

bool	is_stopped () const
	Check if the async callback is triggered to stop the cycle.

bool	is_paused () const
	Check if the async callback thread is paused.

std::thread &	get_thread ()
	Get the async worker thread.

const std::thread &	get_thread () const
	Get the const version of async worker thread.

const AsyncFunctionHandlerParams &	get_params () const
	Get the parameters used to configure the AsyncFunctionHandler.

bool	is_trigger_cycle_in_progress () const
	Check if the async callback method is in progress.

void	stop_thread ()
	Stops the callback thread.

std::chrono::nanoseconds	get_last_execution_time () const
	Get the last execution time of the async callback method.

void	start_thread ()
	Initializes and starts the callback thread.

Detailed Description

template<typename T>
class realtime_tools::AsyncFunctionHandler< T >

Class to handle asynchronous function calls. AsyncFunctionHandler is a class that allows the user to have a asynchronous call to the parsed method and be able to set some thread specific parameters.

Member Function Documentation

◆ get_current_callback_period()

template<typename T >

const rclcpp::Duration & realtime_tools::AsyncFunctionHandler< T >::get_current_callback_period ( ) const

inline

Get the current callback period.

Returns: The current callback period

◆ get_current_callback_time()

template<typename T >

const rclcpp::Time & realtime_tools::AsyncFunctionHandler< T >::get_current_callback_time ( ) const

inline

Get the current callback time.

Returns: The current callback time

◆ get_last_execution_time()

template<typename T >

std::chrono::nanoseconds realtime_tools::AsyncFunctionHandler< T >::get_last_execution_time ( ) const

inline

Get the last execution time of the async callback method.

Returns: The last execution time of the async callback method in nanoseconds

◆ get_last_return_value()

template<typename T >

T realtime_tools::AsyncFunctionHandler< T >::get_last_return_value ( ) const

inline

Get the last return value of the async callback method.

Returns: The last return value of the async callback method

◆ get_params()

template<typename T >

const AsyncFunctionHandlerParams & realtime_tools::AsyncFunctionHandler< T >::get_params ( ) const

inline

Get the parameters used to configure the AsyncFunctionHandler.

Returns: The parameters used to configure the AsyncFunctionHandler

◆ get_thread() [1/2]

template<typename T >

std::thread & realtime_tools::AsyncFunctionHandler< T >::get_thread ( )

inline

Get the async worker thread.

Returns: The async callback thread

◆ get_thread() [2/2]

template<typename T >

const std::thread & realtime_tools::AsyncFunctionHandler< T >::get_thread ( ) const

inline

Get the const version of async worker thread.

Returns: The async callback thread

◆ init() [1/2]

template<typename T >

void realtime_tools::AsyncFunctionHandler< T >::init	(	std::function< T(const rclcpp::Time &, const rclcpp::Duration &)>	callback,
		int	thread_priority = `50`
	)

inline

Initialize the AsyncFunctionHandler with the callback and thread_priority.

Parameters

callback Function that will be called asynchronously If the AsyncFunctionHandler is already initialized and is running, it will throw a runtime error. If the parsed functions are not valid, it will throw a runtime error.

◆ init() [2/2]

template<typename T >

void realtime_tools::AsyncFunctionHandler< T >::init	(	std::function< T(const rclcpp::Time &, const rclcpp::Duration &)>	callback,
		std::function< bool()>	trigger_predicate,
		int	thread_priority = `50`
	)

inline

Initialize the AsyncFunctionHandler with the callback, trigger_predicate and thread_priority.

Parameters

callback	Function that will be called asynchronously.
trigger_predicate	Predicate function that will be called to check if the async callback method should be triggered or not.
thread_priority	Priority of the async worker thread.

Note: The parsed trigger_predicate should be free from any concurrency issues. It is expected to be both thread-safe and reentrant.

If the AsyncFunctionHandler is already initialized and is running, it will throw a runtime error. If the parsed functions are not valid, it will throw a runtime error.

◆ is_initialized()

template<typename T >

bool realtime_tools::AsyncFunctionHandler< T >::is_initialized ( ) const

inline

Check if the AsyncFunctionHandler is initialized.

Returns: True if the AsyncFunctionHandler is initialized, false otherwise

◆ is_paused()

template<typename T >

bool realtime_tools::AsyncFunctionHandler< T >::is_paused ( ) const

inline

Check if the async callback thread is paused.

Returns: True if the async callback thread is paused, false otherwise

◆ is_running()

template<typename T >

bool realtime_tools::AsyncFunctionHandler< T >::is_running ( ) const

inline

Check if the async worker thread is running.

Returns: True if the async worker thread is running, false otherwise

◆ is_stopped()

template<typename T >

bool realtime_tools::AsyncFunctionHandler< T >::is_stopped ( ) const

inline

Check if the async callback is triggered to stop the cycle.

Returns: True if the async callback is requested to be stopped, false otherwise

◆ is_trigger_cycle_in_progress()

template<typename T >

bool realtime_tools::AsyncFunctionHandler< T >::is_trigger_cycle_in_progress ( ) const

inline

Check if the async callback method is in progress.

Returns: True if the async callback method is in progress, false otherwise

◆ join_async_callback_thread()

template<typename T >

void realtime_tools::AsyncFunctionHandler< T >::join_async_callback_thread ( )

inline

Join the async callback thread.

If the async method is running, it will join the async thread. If the async method is not running, it will return immediately.

◆ pause_execution()

template<typename T >

bool realtime_tools::AsyncFunctionHandler< T >::pause_execution ( )

inline

Pauses the execution of the async callback thread.

If the async method is running, it will pause the async thread until the next trigger cycle. If the async method is not running, it will return immediately.

Note: This method is non real-time safe, as it uses a mutex to pause the thread.

Returns: True if the async callback thread was paused, false otherwise.

◆ reset_variables()

template<typename T >

void realtime_tools::AsyncFunctionHandler< T >::reset_variables ( )

inline

Resets the internal variables of the AsyncFunctionHandler.

A method to reset the internal variables of the AsyncFunctionHandler. It will reset the async callback return value, exception pointer, and the trigger status.

Note: This method should be invoked after catching an exception in the async callback thread, to be able to trigger the async callback method again.

◆ start_thread()

template<typename T >

void realtime_tools::AsyncFunctionHandler< T >::start_thread ( )

inline

Initializes and starts the callback thread.

If the worker thread is not running, it will start the async callback thread. If the worker thread is already configured and running, does nothing and returns immediately.

◆ stop_thread()

template<typename T >

void realtime_tools::AsyncFunctionHandler< T >::stop_thread ( )

inline

Stops the callback thread.

If the async method is running, it will notify the async thread to stop and then joins the async thread.

◆ trigger_async_callback()

template<typename T >

std::pair< bool, T > realtime_tools::AsyncFunctionHandler< T >::trigger_async_callback	(	const rclcpp::Time &	time,
		const rclcpp::Duration &	period
	)

inline

Triggers the async callback method cycle.

Parameters

time	Current time
period	Current period

Returns: A pair with the first element being a boolean indicating if the async callback method was triggered and the second element being the last return value of the async function. If the AsyncFunctionHandler is not initialized properly, it will throw a runtime error. If the callback method is waiting for the trigger, it will notify the async thread to start the callback. If the async callback method is still running, it will return the last return value from the last trigger cycle.

Note: If an exception is caught in the async callback thread, it will be rethrown in the current thread, so in order to have the trigger_async_callback method working again, the exception should be caught and the reset_variables method should be invoked.; In the case of controllers, The controller manager is responsible for triggering and maintaining the controller's update rate, as it should be only acting as a scheduler. Same applies to the resource manager when handling the hardware components.

◆ wait_for_trigger_cycle_to_finish()

template<typename T >

bool realtime_tools::AsyncFunctionHandler< T >::wait_for_trigger_cycle_to_finish ( )

inline

Waits until the current async callback method trigger cycle is finished.

If the async method is running, it will wait for the current async method call to finish.

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

realtime_tools/realtime_tools/include/realtime_tools/async_function_handler.hpp

Public Member Functions

Detailed Description

Member Function Documentation

◆ get_current_callback_period()

◆ get_current_callback_time()

◆ get_last_execution_time()

◆ get_last_return_value()

◆ get_params()

◆ get_thread() [1/2]

◆ get_thread() [2/2]

◆ init() [1/2]

◆ init() [2/2]

◆ is_initialized()

◆ is_paused()

◆ is_running()

◆ is_stopped()

◆ is_trigger_cycle_in_progress()

◆ join_async_callback_thread()

◆ pause_execution()

◆ reset_variables()

◆ start_thread()

◆ stop_thread()

◆ trigger_async_callback()

◆ wait_for_trigger_cycle_to_finish()