Subscription implementation, templated on the type of message this subscription receives. More...

#include <rclcpp/subscription.hpp>

Inheritance diagram for rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >:

Collaboration diagram for rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >:

[legend]

Public Types
using	SubscribedType = SubscribedT

using	ROSMessageType = ROSMessageT

using	MessageMemoryStrategyType = MessageMemoryStrategyT

using	SubscribedTypeAllocatorTraits = allocator::AllocRebind< SubscribedType, AllocatorT >

using	SubscribedTypeAllocator = typename SubscribedTypeAllocatorTraits::allocator_type

using	SubscribedTypeDeleter = allocator::Deleter< SubscribedTypeAllocator, SubscribedType >

using	ROSMessageTypeAllocatorTraits = allocator::AllocRebind< ROSMessageType, AllocatorT >

using	ROSMessageTypeAllocator = typename ROSMessageTypeAllocatorTraits::allocator_type

using	ROSMessageTypeDeleter = allocator::Deleter< ROSMessageTypeAllocator, ROSMessageType >

Public Types inherited from rclcpp::SubscriptionBase
using	IntraProcessManagerWeakPtr = std::weak_ptr< rclcpp::experimental::IntraProcessManager >

Public Member Functions
	Subscription (rclcpp::node_interfaces::NodeBaseInterface *node_base, const rosidl_message_type_support_t &type_support_handle, const std::string &topic_name, const rclcpp::QoS &qos, AnySubscriptionCallback< MessageT, AllocatorT > callback, const rclcpp::SubscriptionOptionsWithAllocator< AllocatorT > &options, typename MessageMemoryStrategyT::SharedPtr message_memory_strategy, SubscriptionTopicStatisticsSharedPtr subscription_topic_statistics=nullptr)
	Default constructor. More...

void	post_init_setup ([[maybe_unused]] rclcpp::node_interfaces::NodeBaseInterface *node_base, [[maybe_unused]] const rclcpp::QoS &qos, [[maybe_unused]] const rclcpp::SubscriptionOptionsWithAllocator< AllocatorT > &options)
	Called after construction to continue setup that requires shared_from_this().

bool	take (ROSMessageType &message_out, rclcpp::MessageInfo &message_info_out)
	Take the next message from the inter-process subscription. More...

template<typename TakeT >
std::enable_if_t< !rosidl_generator_traits::is_message< TakeT >::value &&std::is_same_v< TakeT, SubscribedType >, bool >	take (TakeT &message_out, rclcpp::MessageInfo &message_info_out)
	Take the next message from the inter-process subscription. More...

std::shared_ptr< void >	create_message () override
	Borrow a new message. More...

std::shared_ptr< rclcpp::SerializedMessage >	create_serialized_message () override
	Borrow a new serialized message. More...

void	disable_callbacks () override
	Disable callbacks from being called. More...

void	enable_callbacks () override
	Enable the callbacks to be called. More...

void	handle_message (std::shared_ptr< void > &message, const rclcpp::MessageInfo &message_info) override
	Check if we need to handle the message, and execute the callback if we do. More...

void	handle_serialized_message (const std::shared_ptr< rclcpp::SerializedMessage > &serialized_message, const rclcpp::MessageInfo &message_info) override

void	handle_loaned_message (void *loaned_message, const rclcpp::MessageInfo &message_info) override

void	return_message (std::shared_ptr< void > &message) override
	Return the borrowed message. More...

void	return_serialized_message (std::shared_ptr< rclcpp::SerializedMessage > &message) override
	Return the borrowed serialized message. More...

bool	use_take_shared_method () const

rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr	get_shared_dynamic_message_type () override

rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr	get_shared_dynamic_message () override

rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr	get_shared_dynamic_serialization_support () override

rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr	create_dynamic_message () override
	Borrow a new serialized message (this clones!) More...

void	return_dynamic_message ([[maybe_unused]] rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr &message) override

void	handle_dynamic_message ([[maybe_unused]] const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr &message, [[maybe_unused]] const rclcpp::MessageInfo &message_info) override

Public Member Functions inherited from rclcpp::SubscriptionBase
RCLCPP_PUBLIC	SubscriptionBase (rclcpp::node_interfaces::NodeBaseInterface *node_base, const rosidl_message_type_support_t &type_support_handle, const std::string &topic_name, const rcl_subscription_options_t &subscription_options, const SubscriptionEventCallbacks &event_callbacks, bool use_default_callbacks, DeliveredMessageKind delivered_message_kind=DeliveredMessageKind::ROS_MESSAGE)
	Constructor. More...

virtual RCLCPP_PUBLIC	~SubscriptionBase ()
	Destructor.

RCLCPP_PUBLIC void	bind_event_callbacks (const SubscriptionEventCallbacks &event_callbacks, bool use_default_callbacks)
	Add event handlers for passed in event_callbacks.

RCLCPP_PUBLIC const char *	get_topic_name () const
	Get the topic that this subscription is subscribed on.

RCLCPP_PUBLIC std::shared_ptr< rcl_subscription_t >	get_subscription_handle ()

RCLCPP_PUBLIC std::shared_ptr< const rcl_subscription_t >	get_subscription_handle () const

RCLCPP_PUBLIC const std::unordered_map< rcl_subscription_event_type_t, std::shared_ptr< rclcpp::EventHandlerBase > > &	get_event_handlers () const
	Get all the QoS event handlers associated with this subscription. More...

RCLCPP_PUBLIC rclcpp::QoS	get_actual_qos () const
	Get the actual QoS settings, after the defaults have been determined. More...

RCLCPP_PUBLIC bool	take_type_erased (void *message_out, rclcpp::MessageInfo &message_info_out)
	Take the next inter-process message from the subscription as a type erased pointer. More...

RCLCPP_PUBLIC bool	take_serialized (rclcpp::SerializedMessage &message_out, rclcpp::MessageInfo &message_info_out)
	Take the next inter-process message, in its serialized form, from the subscription. More...

RCLCPP_PUBLIC const rosidl_message_type_support_t &	get_message_type_support_handle () const

RCLCPP_PUBLIC bool	is_serialized () const
	Return if the subscription is serialized. More...

RCLCPP_PUBLIC DeliveredMessageKind	get_delivered_message_kind () const
	Return the delivered message kind. More...

RCLCPP_PUBLIC size_t	get_publisher_count () const
	Get matching publisher count. More...

RCLCPP_PUBLIC bool	can_loan_messages () const
	Check if subscription instance can loan messages. More...

RCLCPP_PUBLIC void	setup_intra_process (uint64_t intra_process_subscription_id, IntraProcessManagerWeakPtr weak_ipm)
	Implemenation detail.

RCLCPP_PUBLIC rclcpp::Waitable::SharedPtr	get_intra_process_waitable () const
	Return the waitable for intra-process. More...

RCLCPP_PUBLIC bool	exchange_in_use_by_wait_set_state (void *pointer_to_subscription_part, bool in_use_state)
	Exchange state of whether or not a part of the subscription is used by a wait set. More...

RCLCPP_PUBLIC std::vector< rclcpp::NetworkFlowEndpoint >	get_network_flow_endpoints () const
	Get network flow endpoints. More...

void	set_on_new_message_callback (const std::function< void(size_t)> &callback)
	Set a callback to be called when each new message is received. More...

void	clear_on_new_message_callback ()
	Unset the callback registered for new messages, if any.

void	set_on_new_intra_process_message_callback (const std::function< void(size_t)> &callback)
	Set a callback to be called when each new intra-process message is received. More...

void	clear_on_new_intra_process_message_callback ()
	Unset the callback registered for new intra-process messages, if any.

void	set_on_new_qos_event_callback (const std::function< void(size_t)> &callback, rcl_subscription_event_type_t event_type)
	Set a callback to be called when each new qos event instance occurs. More...

void	clear_on_new_qos_event_callback (rcl_subscription_event_type_t event_type)
	Unset the callback registered for new qos events, if any.

RCLCPP_PUBLIC bool	is_cft_supported () const
	Check if content filtered topic feature of the subscription instance is supported. More...

RCLCPP_PUBLIC bool	is_cft_enabled () const
	Check if content filtered topic feature of the subscription instance is enabled. More...

RCLCPP_PUBLIC void	set_content_filter (const std::string &filter_expression, const std::vector< std::string > &expression_parameters={})
	Set the filter expression and expression parameters for the subscription. More...

RCLCPP_PUBLIC rclcpp::ContentFilterOptions	get_content_filter () const
	Get the filter expression and expression parameters for the subscription. More...

virtual RCLCPP_PUBLIC void	return_dynamic_message (rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr &message)=0

virtual RCLCPP_PUBLIC void	handle_dynamic_message (const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr &message, const rclcpp::MessageInfo &message_info)=0

RCLCPP_PUBLIC bool	take_dynamic_message (rclcpp::dynamic_typesupport::DynamicMessage &message_out, rclcpp::MessageInfo &message_info_out)

Friends
class	rclcpp::node_interfaces::NodeTopicsInterface

Additional Inherited Members
Protected Member Functions inherited from rclcpp::SubscriptionBase
template<typename EventCallbackT >
void	add_event_handler (const EventCallbackT &callback, const rcl_subscription_event_type_t event_type)

RCLCPP_PUBLIC void	default_incompatible_qos_callback (QOSRequestedIncompatibleQoSInfo &info) const

RCLCPP_PUBLIC void	default_incompatible_type_callback (IncompatibleTypeInfo &info) const

RCLCPP_PUBLIC bool	matches_any_intra_process_publishers (const rmw_gid_t *sender_gid) const

RCLCPP_PUBLIC void	set_on_new_message_callback (rcl_event_callback_t callback, const void *user_data)

Protected Attributes inherited from rclcpp::SubscriptionBase
rclcpp::node_interfaces::NodeBaseInterface *const	node_base_

std::shared_ptr< rcl_node_t >	node_handle_

std::recursive_mutex	on_new_message_callback_mutex_

std::function< void(size_t)>	on_new_message_callback_ {nullptr}

std::shared_ptr< rcl_subscription_t >	subscription_handle_

std::shared_ptr< rcl_subscription_t >	intra_process_subscription_handle_

rclcpp::Logger	node_logger_

std::unordered_map< rcl_subscription_event_type_t, std::shared_ptr< rclcpp::EventHandlerBase > >	event_handlers_

bool	use_intra_process_

IntraProcessManagerWeakPtr	weak_ipm_

uint64_t	intra_process_subscription_id_

std::shared_ptr< rclcpp::experimental::SubscriptionIntraProcessBase >	subscription_intra_process_

const SubscriptionEventCallbacks	event_callbacks_

Detailed Description

template<typename MessageT, typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>
class rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >

Subscription implementation, templated on the type of message this subscription receives.

Definition at line 75 of file subscription.hpp.

Constructor & Destructor Documentation

◆ Subscription()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::Subscription	(	rclcpp::node_interfaces::NodeBaseInterface *	node_base,
		const rosidl_message_type_support_t &	type_support_handle,
		const std::string &	topic_name,
		const rclcpp::QoS &	qos,
		AnySubscriptionCallback< MessageT, AllocatorT >	callback,
		const rclcpp::SubscriptionOptionsWithAllocator< AllocatorT > &	options,
		typename MessageMemoryStrategyT::SharedPtr	message_memory_strategy,
		SubscriptionTopicStatisticsSharedPtr	subscription_topic_statistics = `nullptr`
	)

inline

Default constructor.

The constructor for a subscription is almost never called directly. Instead, subscriptions should be instantiated through the function rclcpp::create_subscription().

Parameters

[in]	node_base	NodeBaseInterface pointer that is used in part of the setup.
[in]	type_support_handle	rosidl type support struct, for the Message type of the topic.
[in]	topic_name	Name of the topic to subscribe to.
[in]	qos	QoS profile for Subcription.
[in]	callback	User defined callback to call when a message is received.
[in]	options	Options for the subscription.
[in]	message_memory_strategy	The memory strategy to be used for managing message memory.
[in]	subscription_topic_statistics	Optional pointer to a topic statistics subcription.

Exceptions

std::invalid_argument if the QoS is uncompatible with intra-process (if one of the following conditions are true: qos_profile.history == RMW_QOS_POLICY_HISTORY_KEEP_ALL, qos_profile.depth == 0 or qos_profile.durability != RMW_QOS_POLICY_DURABILITY_VOLATILE).

Definition at line 119 of file subscription.hpp.

References rclcpp::SubscriptionBase::get_actual_qos(), and rclcpp::SubscriptionBase::setup_intra_process().

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Member Function Documentation

◆ create_dynamic_message()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::create_dynamic_message ( )

inlineoverridevirtual

Borrow a new serialized message (this clones!)

Returns: Shared pointer to a rclcpp::dynamic_typesupport::DynamicMessage.

Implements rclcpp::SubscriptionBase.

Definition at line 472 of file subscription.hpp.

◆ create_message()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

std::shared_ptr<void> rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::create_message ( )

inlineoverridevirtual

Borrow a new message.

Returns: Shared pointer to the fresh message.

Implements rclcpp::SubscriptionBase.

Definition at line 280 of file subscription.hpp.

◆ create_serialized_message()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

std::shared_ptr<rclcpp::SerializedMessage> rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::create_serialized_message ( )

inlineoverridevirtual

Borrow a new serialized message.

Returns: Shared pointer to a rcl_message_serialized_t.

Implements rclcpp::SubscriptionBase.

Definition at line 290 of file subscription.hpp.

◆ disable_callbacks()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

void rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::disable_callbacks ( )

inlineoverridevirtual

Disable callbacks from being called.

This method will block, until any subscription's callbacks provided during construction currently being executed are finished.

Note: This method also temporary removes the on new message callback and all on new event callbacks from the rmw layer to prevent them from being called. However, this method will not block and wait until the currently executing on_new_[message]event callbacks are finished.

Reimplemented from rclcpp::SubscriptionBase.

Definition at line 305 of file subscription.hpp.

References rclcpp::SubscriptionBase::disable_callbacks().

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◆ enable_callbacks()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

void rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::enable_callbacks ( )

inlineoverridevirtual

Enable the callbacks to be called.

This method is thread safe, and provides a safe way to atomically enable the callbacks in a multithreaded environment.

Reimplemented from rclcpp::SubscriptionBase.

Definition at line 325 of file subscription.hpp.

References rclcpp::SubscriptionBase::enable_callbacks().

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◆ handle_message()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

void rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::handle_message	(	std::shared_ptr< void > &	message,
		const rclcpp::MessageInfo &	message_info
	)

inlineoverridevirtual

Check if we need to handle the message, and execute the callback if we do.

Parameters

[in]	message	Shared pointer to the message to handle.
[in]	message_info	Metadata associated with this message.

Implements rclcpp::SubscriptionBase.

Definition at line 340 of file subscription.hpp.

References rclcpp::MessageInfo::get_rmw_message_info().

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◆ return_message()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

void rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::return_message ( std::shared_ptr< void > & message )

inlineoverridevirtual

Return the borrowed message.

Parameters

[in,out] message message to be returned

Implements rclcpp::SubscriptionBase.

Definition at line 425 of file subscription.hpp.

◆ return_serialized_message()

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

void rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::return_serialized_message ( std::shared_ptr< rclcpp::SerializedMessage > & message )

inlineoverridevirtual

Return the borrowed serialized message.

Parameters

[in,out] message serialized message to be returned

Implements rclcpp::SubscriptionBase.

Definition at line 436 of file subscription.hpp.

◆ take() [1/2]

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

bool rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::take	(	ROSMessageType &	message_out,
		rclcpp::MessageInfo &	message_info_out
	)

inline

Take the next message from the inter-process subscription.

Data may be taken (written) into the message_out and message_info_out even if false is returned. Specifically in the case of dropping redundant intra-process data, where data is received via both intra-process and inter-process (due to the underlying middleware being unabled to avoid this duplicate delivery) and so inter-process data from those intra-process publishers is ignored, but it has to be taken to know if it came from an intra-process publisher or not, and therefore could be dropped.

See also: SubscriptionBase::take_type_erased()

Parameters

[out]	message_out	The message into which take will copy the data.
[out]	message_info_out	The message info for the taken message.

Returns: true if data was taken and is valid, otherwise false

Exceptions

any	rcl errors from rcl_take,

See also: rclcpp::exceptions::throw_from_rcl_error()

Definition at line 251 of file subscription.hpp.

References rclcpp::SubscriptionBase::take_type_erased().

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◆ take() [2/2]

template<typename MessageT , typename AllocatorT = std::allocator<void>, typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type, typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type, typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy< ROSMessageT, AllocatorT >>

template<typename TakeT >

std::enable_if_t< !rosidl_generator_traits::is_message<TakeT>::value && std::is_same_v<TakeT, SubscribedType>, bool > rclcpp::Subscription< MessageT, AllocatorT, SubscribedT, ROSMessageT, MessageMemoryStrategyT >::take	(	TakeT &	message_out,
		rclcpp::MessageInfo &	message_info_out
	)

inline

Take the next message from the inter-process subscription.

This version takes a SubscribedType which is different from the ROSMessageType when a rclcpp::TypeAdapter is in used.

See also: take(ROSMessageType &, rclcpp::MessageInfo &)

Definition at line 269 of file subscription.hpp.

References rclcpp::SubscriptionBase::take_type_erased().

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

rclcpp/include/rclcpp/subscription.hpp

Public Types

Public Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Subscription()

Member Function Documentation

◆ create_dynamic_message()

◆ create_message()

◆ create_serialized_message()

◆ disable_callbacks()

◆ enable_callbacks()

◆ handle_message()

◆ return_message()

◆ return_serialized_message()

◆ take() [1/2]

◆ take() [2/2]