WaitSet policy that provides thread-safe synchronization for the wait set. More...

#include <thread_safe_synchronization.hpp>

Inheritance diagram for rclcpp::wait_set_policies::ThreadSafeSynchronization:

Collaboration diagram for rclcpp::wait_set_policies::ThreadSafeSynchronization:

[legend]

Protected Member Functions
	ThreadSafeSynchronization (rclcpp::Context::SharedPtr context)

	~ThreadSafeSynchronization ()=default

const std::array< std::shared_ptr< rclcpp::GuardCondition >, 1 > &	get_extra_guard_conditions ()
	Return any "extra" guard conditions needed to implement the synchronization policy. More...

void	interrupt_waiting_wait_set ()
	Interrupt any waiting wait set. More...

void	sync_add_subscription (std::shared_ptr< rclcpp::SubscriptionBase > &&subscription, const rclcpp::SubscriptionWaitSetMask &mask, std::function< void(std::shared_ptr< rclcpp::SubscriptionBase > &&, const rclcpp::SubscriptionWaitSetMask &) > add_subscription_function)
	Add subscription. More...

void	sync_remove_subscription (std::shared_ptr< rclcpp::SubscriptionBase > &&subscription, const rclcpp::SubscriptionWaitSetMask &mask, std::function< void(std::shared_ptr< rclcpp::SubscriptionBase > &&, const rclcpp::SubscriptionWaitSetMask &) > remove_subscription_function)
	Remove guard condition. More...

void	sync_add_guard_condition (std::shared_ptr< rclcpp::GuardCondition > &&guard_condition, std::function< void(std::shared_ptr< rclcpp::GuardCondition > &&)> add_guard_condition_function)
	Add guard condition. More...

void	sync_remove_guard_condition (std::shared_ptr< rclcpp::GuardCondition > &&guard_condition, std::function< void(std::shared_ptr< rclcpp::GuardCondition > &&)> remove_guard_condition_function)
	Remove guard condition. More...

void	sync_add_timer (std::shared_ptr< rclcpp::TimerBase > &&timer, std::function< void(std::shared_ptr< rclcpp::TimerBase > &&)> add_timer_function)
	Add timer. More...

void	sync_remove_timer (std::shared_ptr< rclcpp::TimerBase > &&timer, std::function< void(std::shared_ptr< rclcpp::TimerBase > &&)> remove_timer_function)
	Remove timer. More...

void	sync_add_client (std::shared_ptr< rclcpp::ClientBase > &&client, std::function< void(std::shared_ptr< rclcpp::ClientBase > &&)> add_client_function)
	Add client. More...

void	sync_remove_client (std::shared_ptr< rclcpp::ClientBase > &&client, std::function< void(std::shared_ptr< rclcpp::ClientBase > &&)> remove_client_function)
	Remove client. More...

void	sync_add_service (std::shared_ptr< rclcpp::ServiceBase > &&service, std::function< void(std::shared_ptr< rclcpp::ServiceBase > &&)> add_service_function)
	Add service. More...

void	sync_remove_service (std::shared_ptr< rclcpp::ServiceBase > &&service, std::function< void(std::shared_ptr< rclcpp::ServiceBase > &&)> remove_service_function)
	Remove service. More...

void	sync_add_waitable (std::shared_ptr< rclcpp::Waitable > &&waitable, std::shared_ptr< void > &&associated_entity, std::function< void(std::shared_ptr< rclcpp::Waitable > &&, std::shared_ptr< void > &&) > add_waitable_function)
	Add waitable. More...

void	sync_remove_waitable (std::shared_ptr< rclcpp::Waitable > &&waitable, std::function< void(std::shared_ptr< rclcpp::Waitable > &&)> remove_waitable_function)
	Remove waitable. More...

void	sync_prune_deleted_entities (std::function< void()> prune_deleted_entities_function)
	Prune deleted entities. More...

template<class WaitResultT >
WaitResultT	sync_wait (std::chrono::nanoseconds time_to_wait_ns, std::function< void()> rebuild_rcl_wait_set, std::function< rcl_wait_set_t &()> get_rcl_wait_set, std::function< WaitResultT(WaitResultKind wait_result_kind)> create_wait_result)
	Implements wait. More...

void	sync_wait_result_acquire ()

void	sync_wait_result_release ()

Protected Member Functions inherited from rclcpp::wait_set_policies::detail::SynchronizationPolicyCommon
	SynchronizationPolicyCommon ()=default

	~SynchronizationPolicyCommon ()=default

std::function< bool()>	create_loop_predicate (std::chrono::nanoseconds time_to_wait_ns, std::chrono::steady_clock::time_point start)

std::chrono::nanoseconds	calculate_time_left_to_wait (std::chrono::nanoseconds original_time_to_wait_ns, std::chrono::steady_clock::time_point start)

Protected Attributes
std::array< std::shared_ptr< rclcpp::GuardCondition >, 1 >	extra_guard_conditions_

rclcpp::wait_set_policies::detail::WritePreferringReadWriteLock	wprw_lock_

Detailed Description

WaitSet policy that provides thread-safe synchronization for the wait set.

This class uses a "write-preferring RW lock" so that adding items to, and removing items from, the wait set will take priority over reading, i.e. waiting. This is done since add and remove calls will interrupt the wait set anyways so it is wasteful to do "fair" locking when there are many add/remove operations queued up.

There are some things to consider about the thread-safety provided by this policy. There are two categories of activities, reading and writing activities. The writing activities include all of the add and remove methods, as well as the prune_deleted_entities() method. The reading methods include the wait() method and keeping a WaitResult in scope. The reading and writing activities will not be run at the same time, and one will block the other. Therefore, if you are holding a WaitResult in scope, and try to add or remove an entity at the same time, they will block each other. The write activities will try to interrupt the wait() method by triggering a guard condition, but they have no way of causing the WaitResult to release its lock.

Constructor & Destructor Documentation

◆ ThreadSafeSynchronization()

rclcpp::wait_set_policies::ThreadSafeSynchronization::ThreadSafeSynchronization ( rclcpp::Context::SharedPtr context )

inlineexplicitprotected

◆ ~ThreadSafeSynchronization()

rclcpp::wait_set_policies::ThreadSafeSynchronization::~ThreadSafeSynchronization ( )

protecteddefault

Member Function Documentation

◆ get_extra_guard_conditions()

const std::array<std::shared_ptr<rclcpp::GuardCondition>, 1>& rclcpp::wait_set_policies::ThreadSafeSynchronization::get_extra_guard_conditions ( )

inlineprotected

Return any "extra" guard conditions needed to implement the synchronization policy.

This policy has one guard condition which is used to interrupt the wait set when adding and removing entities.

◆ interrupt_waiting_wait_set()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::interrupt_waiting_wait_set ( )

inlineprotected

Interrupt any waiting wait set.

Used to interrupt the wait set when adding or removing items.

◆ sync_add_subscription()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_add_subscription	(	std::shared_ptr< rclcpp::SubscriptionBase > &&	subscription,
		const rclcpp::SubscriptionWaitSetMask &	mask,
		std::function< void(std::shared_ptr< rclcpp::SubscriptionBase > &&, const rclcpp::SubscriptionWaitSetMask &) >	add_subscription_function
	)

inlineprotected

Add subscription.

◆ sync_remove_subscription()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_remove_subscription	(	std::shared_ptr< rclcpp::SubscriptionBase > &&	subscription,
		const rclcpp::SubscriptionWaitSetMask &	mask,
		std::function< void(std::shared_ptr< rclcpp::SubscriptionBase > &&, const rclcpp::SubscriptionWaitSetMask &) >	remove_subscription_function
	)

inlineprotected

Remove guard condition.

◆ sync_add_guard_condition()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_add_guard_condition	(	std::shared_ptr< rclcpp::GuardCondition > &&	guard_condition,
		std::function< void(std::shared_ptr< rclcpp::GuardCondition > &&)>	add_guard_condition_function
	)

inlineprotected

Add guard condition.

◆ sync_remove_guard_condition()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_remove_guard_condition	(	std::shared_ptr< rclcpp::GuardCondition > &&	guard_condition,
		std::function< void(std::shared_ptr< rclcpp::GuardCondition > &&)>	remove_guard_condition_function
	)

inlineprotected

Remove guard condition.

◆ sync_add_timer()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_add_timer	(	std::shared_ptr< rclcpp::TimerBase > &&	timer,
		std::function< void(std::shared_ptr< rclcpp::TimerBase > &&)>	add_timer_function
	)

inlineprotected

Add timer.

◆ sync_remove_timer()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_remove_timer	(	std::shared_ptr< rclcpp::TimerBase > &&	timer,
		std::function< void(std::shared_ptr< rclcpp::TimerBase > &&)>	remove_timer_function
	)

inlineprotected

Remove timer.

◆ sync_add_client()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_add_client	(	std::shared_ptr< rclcpp::ClientBase > &&	client,
		std::function< void(std::shared_ptr< rclcpp::ClientBase > &&)>	add_client_function
	)

inlineprotected

Add client.

◆ sync_remove_client()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_remove_client	(	std::shared_ptr< rclcpp::ClientBase > &&	client,
		std::function< void(std::shared_ptr< rclcpp::ClientBase > &&)>	remove_client_function
	)

inlineprotected

Remove client.

◆ sync_add_service()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_add_service	(	std::shared_ptr< rclcpp::ServiceBase > &&	service,
		std::function< void(std::shared_ptr< rclcpp::ServiceBase > &&)>	add_service_function
	)

inlineprotected

Add service.

◆ sync_remove_service()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_remove_service	(	std::shared_ptr< rclcpp::ServiceBase > &&	service,
		std::function< void(std::shared_ptr< rclcpp::ServiceBase > &&)>	remove_service_function
	)

inlineprotected

Remove service.

◆ sync_add_waitable()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_add_waitable	(	std::shared_ptr< rclcpp::Waitable > &&	waitable,
		std::shared_ptr< void > &&	associated_entity,
		std::function< void(std::shared_ptr< rclcpp::Waitable > &&, std::shared_ptr< void > &&) >	add_waitable_function
	)

inlineprotected

Add waitable.

◆ sync_remove_waitable()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_remove_waitable	(	std::shared_ptr< rclcpp::Waitable > &&	waitable,
		std::function< void(std::shared_ptr< rclcpp::Waitable > &&)>	remove_waitable_function
	)

inlineprotected

Remove waitable.

◆ sync_prune_deleted_entities()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_prune_deleted_entities ( std::function< void()> prune_deleted_entities_function )

inlineprotected

Prune deleted entities.

◆ sync_wait()

template<class WaitResultT >

WaitResultT rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_wait	(	std::chrono::nanoseconds	time_to_wait_ns,
		std::function< void()>	rebuild_rcl_wait_set,
		std::function< rcl_wait_set_t &()>	get_rcl_wait_set,
		std::function< WaitResultT(WaitResultKind wait_result_kind)>	create_wait_result
	)

inlineprotected

Implements wait.

◆ sync_wait_result_acquire()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_wait_result_acquire ( )

inlineprotected

◆ sync_wait_result_release()

void rclcpp::wait_set_policies::ThreadSafeSynchronization::sync_wait_result_release ( )

inlineprotected

Member Data Documentation

◆ extra_guard_conditions_

std::array<std::shared_ptr<rclcpp::GuardCondition>, 1> rclcpp::wait_set_policies::ThreadSafeSynchronization::extra_guard_conditions_

protected

◆ wprw_lock_

rclcpp::wait_set_policies::detail::WritePreferringReadWriteLock rclcpp::wait_set_policies::ThreadSafeSynchronization::wprw_lock_

protected

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

include/rclcpp/wait_set_policies/thread_safe_synchronization.hpp

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ThreadSafeSynchronization()

◆ ~ThreadSafeSynchronization()

Member Function Documentation

◆ get_extra_guard_conditions()

◆ interrupt_waiting_wait_set()

◆ sync_add_subscription()

◆ sync_remove_subscription()

◆ sync_add_guard_condition()

◆ sync_remove_guard_condition()

◆ sync_add_timer()

◆ sync_remove_timer()

◆ sync_add_client()

◆ sync_remove_client()

◆ sync_add_service()

◆ sync_remove_service()

◆ sync_add_waitable()

◆ sync_remove_waitable()

◆ sync_prune_deleted_entities()

◆ sync_wait()

◆ sync_wait_result_acquire()

◆ sync_wait_result_release()

Member Data Documentation

◆ extra_guard_conditions_

◆ wprw_lock_