rclcpp::Waitable Class Reference

#include <waitable.hpp>

Inheritance diagram for rclcpp::Waitable:

Public Member Functions
virtual	~Waitable ()=default
virtual size_t	get_number_of_ready_subscriptions ()
	Get the number of ready subscriptions. More...
virtual size_t	get_number_of_ready_timers ()
	Get the number of ready timers. More...
virtual size_t	get_number_of_ready_clients ()
	Get the number of ready clients. More...
virtual size_t	get_number_of_ready_events ()
	Get the number of ready events. More...
virtual size_t	get_number_of_ready_services ()
	Get the number of ready services. More...
virtual size_t	get_number_of_ready_guard_conditions ()
	Get the number of ready guard_conditions. More...
virtual bool	add_to_wait_set (rcl_wait_set_t *wait_set)=0
	Add the Waitable to a wait set. More...
virtual bool	is_ready (rcl_wait_set_t *wait_set)=0
	Check if the Waitable is ready. More...
virtual void	execute ()=0
	Execute any entities of the Waitable that are ready. More...
bool	exchange_in_use_by_wait_set_state (bool in_use_state)
	Exchange the "in use by wait set" state for this timer. More...

Constructor & Destructor Documentation

~Waitable()

virtual rclcpp::Waitable::~Waitable ( )

virtualdefault

Member Function Documentation

get_number_of_ready_subscriptions()

virtual size_t rclcpp::Waitable::get_number_of_ready_subscriptions ( )

virtual

Get the number of ready subscriptions.

Returns a value of 0 by default. This should be overridden if the Waitable contains one or more subscriptions.

Returns

The number of subscriptions associated with the Waitable.

get_number_of_ready_timers()

virtual size_t rclcpp::Waitable::get_number_of_ready_timers ( )

virtual

Get the number of ready timers.

Returns a value of 0 by default. This should be overridden if the Waitable contains one or more timers.

Returns

The number of timers associated with the Waitable.

get_number_of_ready_clients()

virtual size_t rclcpp::Waitable::get_number_of_ready_clients ( )

virtual

Get the number of ready clients.

Returns a value of 0 by default. This should be overridden if the Waitable contains one or more clients.

Returns

The number of clients associated with the Waitable.

get_number_of_ready_events()

virtual size_t rclcpp::Waitable::get_number_of_ready_events ( )

virtual

Get the number of ready events.

Returns a value of 0 by default. This should be overridden if the Waitable contains one or more events.

Returns

The number of events associated with the Waitable.

Reimplemented in rclcpp::QOSEventHandlerBase.

get_number_of_ready_services()

virtual size_t rclcpp::Waitable::get_number_of_ready_services ( )

virtual

Get the number of ready services.

Returns a value of 0 by default. This should be overridden if the Waitable contains one or more services.

Returns

The number of services associated with the Waitable.

get_number_of_ready_guard_conditions()

virtual size_t rclcpp::Waitable::get_number_of_ready_guard_conditions ( )

virtual

Get the number of ready guard_conditions.

Returns a value of 0 by default. This should be overridden if the Waitable contains one or more guard_conditions.

Returns

The number of guard_conditions associated with the Waitable.

Reimplemented in rclcpp::executors::StaticExecutorEntitiesCollector, and rclcpp::experimental::SubscriptionIntraProcessBase.

add_to_wait_set()

virtual bool rclcpp::Waitable::add_to_wait_set ( rcl_wait_set_t *  wait_set )

pure virtual

Add the Waitable to a wait set.

Parameters

[in]

wait_set

A handle to the wait set to add the Waitable to.

Returns

true if the Waitable is added successfully, false otherwise.

Exceptions

rclcpp::execptions::RCLError

from rcl_wait_set_add_*()

Implemented in rclcpp::executors::StaticExecutorEntitiesCollector, rclcpp::QOSEventHandlerBase, and rclcpp::experimental::SubscriptionIntraProcessBase.

is_ready()

virtual bool rclcpp::Waitable::is_ready ( rcl_wait_set_t *  wait_set )

pure virtual

Check if the Waitable is ready.

The input wait set should be the same that was used in a previously call to add_to_wait_set(). The wait set should also have been previously waited on with rcl_wait().

Parameters

[in]

wait_set

A handle to the wait set the Waitable was previously added to and that has been waited on.

Returns

true if the Waitable is ready, false otherwise.

Implemented in rclcpp::experimental::SubscriptionIntraProcessBase, rclcpp::executors::StaticExecutorEntitiesCollector, rclcpp::QOSEventHandlerBase, and rclcpp::experimental::SubscriptionIntraProcess< MessageT, Alloc, Deleter, CallbackMessageT >.

execute()

virtual void rclcpp::Waitable::execute ( )

pure virtual

Execute any entities of the Waitable that are ready.

Before calling this method, the Waitable should be added to a wait set, waited on, and then updated.

Example usage:

// ... create a wait set and a Waitable
// Add the Waitable to the wait set
bool add_ret = waitable.add_to_wait_set(wait_set);
// ... error handling
// Wait
rcl_ret_t wait_ret = rcl_wait(wait_set);
// ... error handling
// Update the Waitable
waitable.update(wait_set);
// Execute any entities of the Waitable that may be ready
waitable.execute();

Implemented in rclcpp::experimental::SubscriptionIntraProcessBase, rclcpp::QOSEventHandler< EventCallbackT, ParentHandleT >, rclcpp::executors::StaticExecutorEntitiesCollector, and rclcpp::experimental::SubscriptionIntraProcess< MessageT, Alloc, Deleter, CallbackMessageT >.

exchange_in_use_by_wait_set_state()

bool rclcpp::Waitable::exchange_in_use_by_wait_set_state

(

bool

in_use_state

)

Exchange the "in use by wait set" state for this timer.

This is used to ensure this timer is not used by multiple wait sets at the same time.

Parameters

[in]

in_use_state

the new state to exchange into the state, true indicates it is now in use by a wait set, and false is that it is no longer in use by a wait set.

Returns

the previous state.

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

• include/rclcpp/waitable.hpp