rclcpp::ClientBase Class Reference

Inheritance diagram for rclcpp::ClientBase:

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Public Member Functions
RCLCPP_PUBLIC	ClientBase (rclcpp::node_interfaces::NodeBaseInterface *node_base, rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph)
RCLCPP_PUBLIC bool	take_type_erased_response (void *response_out, rmw_request_id_t &request_header_out)
	Take the next response for this client as a type erased pointer. More...
RCLCPP_PUBLIC const char *	get_service_name () const
	Return the name of the service. More...
RCLCPP_PUBLIC std::shared_ptr< rcl_client_t >	get_client_handle ()
	Return the rcl_client_t client handle in a std::shared_ptr. More...
RCLCPP_PUBLIC std::shared_ptr< const rcl_client_t >	get_client_handle () const
	Return the rcl_client_t client handle in a std::shared_ptr. More...
RCLCPP_PUBLIC bool	service_is_ready () const
	Return if the service is ready. More...
template<typename RepT = int64_t, typename RatioT = std::milli>
bool	wait_for_service (std::chrono::duration< RepT, RatioT > timeout=std::chrono::duration< RepT, RatioT >(-1))
	Wait for a service to be ready. More...
virtual std::shared_ptr< void >	create_response ()=0
virtual std::shared_ptr< rmw_request_id_t >	create_request_header ()=0
virtual void	handle_response (std::shared_ptr< rmw_request_id_t > request_header, std::shared_ptr< void > response)=0
RCLCPP_PUBLIC bool	exchange_in_use_by_wait_set_state (bool in_use_state)
	Exchange the "in use by wait set" state for this client. More...
RCLCPP_PUBLIC rclcpp::QoS	get_request_publisher_actual_qos () const
	Get the actual request publsher QoS settings, after the defaults have been determined. More...
RCLCPP_PUBLIC rclcpp::QoS	get_response_subscription_actual_qos () const
	Get the actual response subscription QoS settings, after the defaults have been determined. More...
void	set_on_new_response_callback (std::function< void(size_t)> callback)
	Set a callback to be called when each new response is received. More...
void	clear_on_new_response_callback ()
	Unset the callback registered for new responses, if any.

Protected Member Functions
RCLCPP_PUBLIC bool	wait_for_service_nanoseconds (std::chrono::nanoseconds timeout)
RCLCPP_PUBLIC rcl_node_t *	get_rcl_node_handle ()
RCLCPP_PUBLIC const rcl_node_t *	get_rcl_node_handle () const
RCLCPP_PUBLIC void	set_on_new_response_callback (rcl_event_callback_t callback, const void *user_data)

Protected Attributes
rclcpp::node_interfaces::NodeGraphInterface::WeakPtr	node_graph_
std::shared_ptr< rcl_node_t >	node_handle_
std::shared_ptr< rclcpp::Context >	context_
rclcpp::Logger	node_logger_
std::recursive_mutex	callback_mutex_
std::function< void(size_t)>	on_new_response_callback_ {nullptr}
std::shared_ptr< rcl_client_t >	client_handle_
std::atomic< bool >	in_use_by_wait_set_ {false}

Detailed Description

Definition at line 140 of file client.hpp.

Member Function Documentation

exchange_in_use_by_wait_set_state()

bool ClientBase::exchange_in_use_by_wait_set_state

(

bool

in_use_state

)

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

This is used to ensure this client 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.

Definition at line 194 of file client.cpp.

get_client_handle() [1/2]

std::shared_ptr< rcl_client_t > ClientBase::get_client_handle

(

)

Return the rcl_client_t client handle in a std::shared_ptr.

This handle remains valid after the Client is destroyed. The actual rcl client is not finalized until it is out of scope everywhere.

Definition at line 92 of file client.cpp.

Referenced by rclcpp::Client< ServiceT >::Client(), get_service_name(), service_is_ready(), and take_type_erased_response().

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get_client_handle() [2/2]

std::shared_ptr< const rcl_client_t > ClientBase::get_client_handle

(

)

const

Return the rcl_client_t client handle in a std::shared_ptr.

This handle remains valid after the Client is destroyed. The actual rcl client is not finalized until it is out of scope everywhere.

Definition at line 98 of file client.cpp.

get_request_publisher_actual_qos()

rclcpp::QoS ClientBase::get_request_publisher_actual_qos

(

)

const

Get the actual request publsher QoS settings, after the defaults have been determined.

The actual configuration applied when using RMW_QOS_POLICY_*_SYSTEM_DEFAULT can only be resolved after the creation of the client, and it depends on the underlying rmw implementation. If the underlying setting in use can't be represented in ROS terms, it will be set to RMW_QOS_POLICY_*_UNKNOWN. May throw runtime_error when an unexpected error occurs.

Returns

The actual request publsher qos settings.

Exceptions

std::runtime_error

if failed to get qos settings

Definition at line 200 of file client.cpp.

References rclcpp::QoSInitialization::from_rmw(), and rcl_client_request_publisher_get_actual_qos().

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get_response_subscription_actual_qos()

rclcpp::QoS ClientBase::get_response_subscription_actual_qos

(

)

const

Get the actual response subscription QoS settings, after the defaults have been determined.

The actual configuration applied when using RMW_QOS_POLICY_*_SYSTEM_DEFAULT can only be resolved after the creation of the client, and it depends on the underlying rmw implementation. If the underlying setting in use can't be represented in ROS terms, it will be set to RMW_QOS_POLICY_*_UNKNOWN. May throw runtime_error when an unexpected error occurs.

Returns

The actual response subscription qos settings.

Exceptions

std::runtime_error

if failed to get qos settings

Definition at line 219 of file client.cpp.

References rclcpp::QoSInitialization::from_rmw(), and rcl_client_response_subscription_get_actual_qos().

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get_service_name()

const char * ClientBase::get_service_name

(

)

const

Return the name of the service.

Returns

The name of the service.

Definition at line 86 of file client.cpp.

References get_client_handle(), and rcl_client_get_service_name().

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service_is_ready()

bool ClientBase::service_is_ready

(

)

const

Return if the service is ready.

Returns

true if the service is ready, false otherwise

Definition at line 104 of file client.cpp.

References rcl_node_s::context, get_client_handle(), rcl_context_is_valid(), RCL_RET_NODE_INVALID, RCL_RET_OK, and rcl_service_server_is_available().

Referenced by rclcpp::AsyncParametersClient::service_is_ready().

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set_on_new_response_callback()

void rclcpp::ClientBase::set_on_new_response_callback ( std::function< void(size_t)>  callback )

inline

Set a callback to be called when each new response is received.

The callback receives a size_t which is the number of responses received since the last time this callback was called. Normally this is 1, but can be > 1 if responses were received before any callback was set.

Since this callback is called from the middleware, you should aim to make it fast and not blocking. If you need to do a lot of work or wait for some other event, you should spin it off to another thread, otherwise you risk blocking the middleware.

Calling it again will clear any previously set callback.

An exception will be thrown if the callback is not callable.

This function is thread-safe.

If you want more information available in the callback, like the client or other information, you may use a lambda with captures or std::bind.

See also

rmw_client_set_on_new_response_callback

rcl_client_set_on_new_response_callback

Parameters

[in]

callback

functor to be called when a new response is received

Definition at line 299 of file client.hpp.

Referenced by clear_on_new_response_callback().

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take_type_erased_response()

bool ClientBase::take_type_erased_response	(	void *	response_out,
		rmw_request_id_t &	request_header_out
	)

Take the next response for this client as a type erased pointer.

The type erased pointer allows for this method to be used in a type agnostic way along with ClientBase::create_response(), ClientBase::create_request_header(), and ClientBase::handle_response(). The typed version of this can be used if the Service type is known,

See also

Client::take_response().

Parameters

[out]	response_out	The type erased pointer to a Service Response into which the middleware will copy the response being taken.
[out]	request_header_out	The request header to be filled by the middleware when taking, and which can be used to associte the response to a specific request.

Returns

true if the response was taken, otherwise false.

Exceptions

rclcpp::exceptions::RCLError

based exceptions if the underlying rcl function fail.

Definition at line 71 of file client.cpp.

References get_client_handle(), RCL_RET_CLIENT_TAKE_FAILED, RCL_RET_OK, and rcl_take_response().

Referenced by rclcpp::GenericClient::take_response(), and rclcpp::Client< ServiceT >::take_response().

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wait_for_service()

template<typename RepT = int64_t, typename RatioT = std::milli>

bool rclcpp::ClientBase::wait_for_service ( std::chrono::duration< RepT, RatioT >  timeout = std::chrono::duration<RepT, RatioT>(-1) )

inline

Wait for a service to be ready.

Parameters

timeout

maximum time to wait

Returns

true if the service is ready and the timeout is not over, false otherwise

Definition at line 213 of file client.hpp.

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

• rclcpp/include/rclcpp/client.hpp
• rclcpp/src/rclcpp/client.cpp