#include "rosidl_runtime_c/service_type_support_struct.h"
#include "rcl/allocator.h"
#include "rcl/event_callback.h"
#include "rcl/macros.h"
#include "rcl/node.h"
#include "rcl/publisher.h"
#include "rcl/service_introspection.h"
#include "rcl/time.h"
#include "rcl/visibility_control.h"
#include "rmw/types.h"

Include dependency graph for service.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	rcl_service_s
	Structure which encapsulates a ROS Service. More...

struct	rcl_service_options_s
	Options available for a rcl service. More...

Typedefs
typedef struct rcl_service_impl_s	rcl_service_impl_t
	Internal rcl implementation struct.

typedef struct rcl_service_s	rcl_service_t
	Structure which encapsulates a ROS Service.

typedef struct rcl_service_options_s	rcl_service_options_t
	Options available for a rcl service.

Functions
RCL_PUBLIC RCL_WARN_UNUSED rcl_service_t	rcl_get_zero_initialized_service (void)
	Return a rcl_service_t struct with members set to `NULL`. More...

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t	rcl_service_init (rcl_service_t service, const rcl_node_t node, const rosidl_service_type_support_t type_support, const char service_name, const rcl_service_options_t *options)
	Initialize a rcl service. More...

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t	rcl_service_fini (rcl_service_t service, rcl_node_t node)
	Finalize a rcl_service_t. More...

RCL_PUBLIC RCL_WARN_UNUSED rcl_service_options_t	rcl_service_get_default_options (void)
	Return the default service options in a rcl_service_options_t. More...

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t	rcl_take_request_with_info (const rcl_service_t service, rmw_service_info_t request_header, void *ros_request)
	Take a pending ROS request using a rcl service. More...

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t	rcl_take_request (const rcl_service_t service, rmw_request_id_t request_header, void *ros_request)
	Backwards compatibility function to take a pending ROS request using a rcl service. More...

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t	rcl_send_response (const rcl_service_t service, rmw_request_id_t response_header, void *ros_response)
	Send a ROS response to a client using a service. More...

RCL_PUBLIC RCL_WARN_UNUSED const char *	rcl_service_get_service_name (const rcl_service_t *service)
	Get the topic name for the service. More...

RCL_PUBLIC RCL_WARN_UNUSED const rcl_service_options_t *	rcl_service_get_options (const rcl_service_t *service)
	Return the rcl service options. More...

RCL_PUBLIC RCL_WARN_UNUSED rmw_service_t *	rcl_service_get_rmw_handle (const rcl_service_t *service)
	Return the rmw service handle. More...

RCL_PUBLIC bool	rcl_service_is_valid (const rcl_service_t *service)
	Check that the service is valid. More...

RCL_PUBLIC RCL_WARN_UNUSED const rmw_qos_profile_t *	rcl_service_request_subscription_get_actual_qos (const rcl_service_t *service)
	Get the actual qos settings of the service's request subscription. More...

RCL_PUBLIC RCL_WARN_UNUSED const rmw_qos_profile_t *	rcl_service_response_publisher_get_actual_qos (const rcl_service_t *service)
	Get the actual qos settings of the service's response publisher. More...

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t	rcl_service_set_on_new_request_callback (const rcl_service_t service, rcl_event_callback_t callback, const void user_data)
	Set the on new request callback function for the service. More...

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t	rcl_service_configure_service_introspection (rcl_service_t service, rcl_node_t node, rcl_clock_t clock, const rosidl_service_type_support_t type_support, const rcl_publisher_options_t publisher_options, rcl_service_introspection_state_t introspection_state)
	Configure service introspection features for the service. More...

Function Documentation

◆ rcl_get_zero_initialized_service()

RCL_PUBLIC RCL_WARN_UNUSED rcl_service_t rcl_get_zero_initialized_service ( void )

Return a rcl_service_t struct with members set to NULL.

Should be called to get a null rcl_service_t before passing to rcl_service_init().

Returns: A structure with a zero initialized service.

Definition at line 55 of file service.c.

Referenced by rclcpp::GenericService::GenericService(), and rclcpp::Service< ServiceT >::Service().

Here is the caller graph for this function:

◆ rcl_send_response()

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t rcl_send_response	(	const rcl_service_t *	service,
		rmw_request_id_t *	response_header,
		void *	ros_response
	)

Send a ROS response to a client using a service.

It is the job of the caller to ensure that the type of the ros_response parameter and the type associate with the service (via the type support) match. Passing a different type to send_response produces undefined behavior and cannot be checked by this function and therefore no deliberate error will occur.

send_response() is an non-blocking call.

The ROS response message given by the ros_response void pointer is always owned by the calling code, but should remain constant during rcl_send_response().

This function is thread safe so long as access to both the service and the ros_response is synchronized. That means that calling rcl_send_response() from multiple threads is allowed, but calling rcl_send_response() at the same time as non-thread safe service functions is not, e.g. calling rcl_send_response() and rcl_service_fini() concurrently is not allowed. The message cannot change during the rcl_send_response() call. Before calling rcl_send_response() the message can change but after calling rcl_send_response() it depends on RMW implementation behavior. The same ros_response, however, can be passed to multiple calls of rcl_send_response() simultaneously, even if the services differ. The ros_response is unmodified by rcl_send_response().

Attribute	Adherence
Allocates Memory	No
Thread-Safe	Yes [1]
Uses Atomics	No
Lock-Free	Yes

[1] for unique pairs of services and responses, see above for more

Parameters

[in]	service	handle to the service which will make the response
[in,out]	response_header	ptr to the struct holding metadata about the request ID
[in]	ros_response	type-erased pointer to the ROS response message

Returns: RCL_RET_OK if the response was sent successfully, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_SERVICE_INVALID if the service is invalid, or; RCL_RET_TIMEOUT if a response reader is not ready yet, or; RCL_RET_ERROR if an unspecified error occurs.

Definition at line 384 of file service.c.

References rcl_service_s::impl, RCL_RET_ERROR, RCL_RET_INVALID_ARGUMENT, RCL_RET_OK, RCL_RET_SERVICE_INVALID, RCL_RET_TIMEOUT, rcl_service_get_options(), and rcl_service_is_valid().

Here is the call graph for this function:

◆ rcl_service_configure_service_introspection()

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t rcl_service_configure_service_introspection	(	rcl_service_t *	service,
		rcl_node_t *	node,
		rcl_clock_t *	clock,
		const rosidl_service_type_support_t *	type_support,
		const rcl_publisher_options_t	publisher_options,
		rcl_service_introspection_state_t	introspection_state
	)

Configure service introspection features for the service.

Enables or disables service introspection features for this service. If the introspection state is RCL_SERVICE_INTROSPECTION_OFF, then introspection will be disabled. If the state is RCL_SERVICE_INTROSPECTION_METADATA, the client metadata will be published. If the state is RCL_SERVICE_INTROSPECTION_CONTENTS, then the client metadata and service request and response contents will be published.

Attribute	Adherence
Allocates Memory	Yes
Thread-Safe	No
Uses Atomics	Maybe [1]
Lock-Free	Maybe [1]

[1] rmw implementation defined

Parameters

[in]	service	service on which to configure service introspection
[in]	node	valid rcl_node_t to use to create the introspection publisher
[in]	clock	valid rcl_clock_t to use to generate the introspection timestamps
[in]	type_support	type support library associated with this service
[in]	publisher_options	options to use when creating the introspection publisher
[in]	introspection_state	rcl_service_introspection_state_t describing whether introspection should be OFF, METADATA, or CONTENTS

Returns: RCL_RET_OK if the call was successful, or; RCL_RET_ERROR if the event publisher is invalid, or; RCL_RET_NODE_INVALID if the given node is invalid, or; RCL_RET_INVALID_ARGUMENT if the client or node structure is invalid,; RCL_RET_BAD_ALLOC if a memory allocation failed

Definition at line 471 of file service.c.

References rcl_service_options_s::allocator, rcl_service_s::impl, RCL_RET_BAD_ALLOC, RCL_RET_INVALID_ARGUMENT, RCL_RET_OK, RCL_RET_SERVICE_INVALID, and rcl_service_is_valid().

Referenced by rclcpp::Service< ServiceT >::configure_introspection().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rcl_service_fini()

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t rcl_service_fini	(	rcl_service_t *	service,
		rcl_node_t *	node
	)

Finalize a rcl_service_t.

After calling, the node will no longer listen for requests for this service. (assuming this is the only service of this type in this node).

After calling, calls to rcl_wait(), rcl_take_request(), and rcl_send_response() will fail when using this service. Additionally rcl_wait() will be interrupted if currently blocking. However, the given node handle is still valid.

Attribute	Adherence
Allocates Memory	Yes
Thread-Safe	No
Uses Atomics	No
Lock-Free	Yes

Parameters

[in,out]	service	handle to the service to be deinitialized
[in]	node	a valid (not finalized) handle to the node used to create the service

Returns: RCL_RET_OK if service was deinitialized successfully, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_SERVICE_INVALID if the service is invalid, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_ERROR if an unspecified error occurs.

Definition at line 234 of file service.c.

References rcl_service_options_s::allocator, rcl_service_s::impl, rcl_node_get_rmw_handle(), rcl_node_is_valid_except_context(), RCL_RET_ERROR, RCL_RET_INVALID_ARGUMENT, RCL_RET_NODE_INVALID, RCL_RET_OK, and RCL_RET_SERVICE_INVALID.

Referenced by rclcpp::GenericService::GenericService(), and rclcpp::Service< ServiceT >::Service().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rcl_service_get_default_options()

RCL_PUBLIC RCL_WARN_UNUSED rcl_service_options_t rcl_service_get_default_options ( void )

Return the default service options in a rcl_service_options_t.

The defaults are:

qos = rmw_qos_profile_services_default
allocator = rcl_get_default_allocator()

Definition at line 286 of file service.c.

References rcl_service_options_s::allocator, rcl_service_options_s::qos, and rcl_get_default_allocator.

Referenced by rclcpp::create_generic_service(), rclcpp::create_service(), and rcl_node_type_description_service_init().

Here is the caller graph for this function:

◆ rcl_service_get_options()

RCL_PUBLIC RCL_WARN_UNUSED const rcl_service_options_t* rcl_service_get_options ( const rcl_service_t * service )

Return the rcl service options.

This function returns the service's internal options struct. This function can fail, and therefore return NULL, if the:

service is NULL
service is invalid (never called init, called fini, or invalid)

The returned struct is only valid as long as the service is valid. The values in the struct may change if the service's options change, and therefore copying the struct is recommended if this is a concern.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	No
Uses Atomics	No
Lock-Free	Yes

Parameters

[in] service pointer to the service

Returns: options struct if successful, otherwise NULL

Definition at line 308 of file service.c.

References rcl_service_s::impl, and rcl_service_is_valid().

Referenced by rcl_send_response(), rcl_service_get_service_name(), and rcl_take_request_with_info().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rcl_service_get_rmw_handle()

RCL_PUBLIC RCL_WARN_UNUSED rmw_service_t* rcl_service_get_rmw_handle ( const rcl_service_t * service )

Return the rmw service handle.

The handle returned is a pointer to the internally held rmw handle. This function can fail, and therefore return NULL, if the:

service is NULL
service is invalid (never called init, called fini, or invalid)

The returned handle is made invalid if the service is finalized or if rcl_shutdown() is called. The returned handle is not guaranteed to be valid for the life time of the service as it may be finalized and recreated itself. Therefore it is recommended to get the handle from the service using this function each time it is needed and avoid use of the handle concurrently with functions that might change it.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	No
Uses Atomics	No
Lock-Free	Yes

Parameters

[in] service pointer to the rcl service

Returns: rmw service handle if successful, otherwise NULL

Definition at line 317 of file service.c.

References rcl_service_s::impl, and rcl_service_is_valid().

Here is the call graph for this function:

◆ rcl_service_get_service_name()

RCL_PUBLIC RCL_WARN_UNUSED const char* rcl_service_get_service_name ( const rcl_service_t * service )

Get the topic name for the service.

This function returns the service's internal topic name string. This function can fail, and therefore return NULL, if the:

service is NULL
service is invalid (never called init, called fini, or invalid)

The returned string is only valid as long as the service is valid. The value of the string may change if the topic name changes, and therefore copying the string is recommended if this is a concern.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	No
Uses Atomics	No
Lock-Free	Yes

Parameters

[in] service the pointer to the service

Returns: name string if successful, otherwise NULL

Definition at line 297 of file service.c.

References rcl_service_s::impl, and rcl_service_get_options().

Referenced by rclcpp::ServiceBase::get_service_name().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rcl_service_init()

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t rcl_service_init	(	rcl_service_t *	service,
		const rcl_node_t *	node,
		const rosidl_service_type_support_t *	type_support,
		const char *	service_name,
		const rcl_service_options_t *	options
	)

Initialize a rcl service.

After calling this function on a rcl_service_t, it can be used to take requests of the given type to the given topic using rcl_take_request(). It can also send a response to a request using rcl_send_response().

The given rcl_node_t must be valid and the resulting rcl_service_t is only valid as long as the given rcl_node_t remains valid.

The rosidl_service_type_support_t is obtained on a per .srv type basis. When the user defines a ROS service, code is generated which provides the required rosidl_service_type_support_t object. This object can be obtained using a language appropriate mechanism.

Todo:: TODO(wjwwood) write these instructions once and link to it instead

For C, a macro can be used (for example example_interfaces/AddTwoInts):

#include <rosidl_runtime_c/service_type_support_struct.h>
#include <example_interfaces/srv/add_two_ints.h>
const rosidl_service_type_support_t * ts =
  ROSIDL_GET_SRV_TYPE_SUPPORT(example_interfaces, srv, AddTwoInts);

For C++, a template function is used:

#include <rosidl_runtime_cpp/service_type_support.hpp>
#include <example_interfaces/srv/add_two_ints.h>
using rosidl_typesupport_cpp::get_service_type_support_handle;
const rosidl_service_type_support_t * ts =
  get_service_type_support_handle<example_interfaces::srv::AddTwoInts>();

The rosidl_service_type_support_t object contains service type specific information used to send or take requests and responses.

The topic name must be a c string which follows the topic and service name format rules for unexpanded names, also known as non-fully qualified names:

See also: rcl_expand_topic_name

The options struct allows the user to set the quality of service settings as well as a custom allocator which is used when initializing/finalizing the service to allocate space for incidentals, e.g. the service name string.

Expected usage (for C services):

#include <rcl/rcl.h>
#include <rosidl_runtime_c/service_type_support_struct.h>
#include <example_interfaces/srv/add_two_ints.h>
 
rcl_node_t node = rcl_get_zero_initialized_node();
rcl_node_options_t node_ops = rcl_node_get_default_options();
rcl_ret_t ret = rcl_node_init(&node, "node_name", "/my_namespace", &node_ops);
// ... error handling
const rosidl_service_type_support_t * ts =
  ROSIDL_GET_SRV_TYPE_SUPPORT(example_interfaces, srv, AddTwoInts);
rcl_service_t service = rcl_get_zero_initialized_service();
rcl_service_options_t service_ops = rcl_service_get_default_options();
ret = rcl_service_init(&service, &node, ts, "add_two_ints", &service_ops);
// ... error handling, and on shutdown do finalization:
ret = rcl_service_fini(&service, &node);
// ... error handling for rcl_service_fini()
ret = rcl_node_fini(&node);
// ... error handling for rcl_node_fini()

Attribute	Adherence
Allocates Memory	Yes
Thread-Safe	No
Uses Atomics	No
Lock-Free	Yes

Parameters

[out]	service	preallocated service structure
[in]	node	valid rcl node handle
[in]	type_support	type support object for the service's type
[in]	service_name	the name of the service
[in]	options	service options, including quality of service settings

Returns: RCL_RET_OK if service was initialized successfully, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ALREADY_INIT if the service is already initialized, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_BAD_ALLOC if allocating memory failed, or; RCL_RET_SERVICE_NAME_INVALID if the given service name is invalid, or; RCL_RET_ERROR if an unspecified error occurs.

Definition at line 86 of file service.c.

References rcl_service_options_s::allocator, rcl_service_s::impl, rcl_service_options_s::qos, RCL_CHECK_ALLOCATOR_WITH_MSG, rcl_node_get_rmw_handle(), rcl_node_is_valid(), rcl_node_resolve_name(), RCL_RET_ALREADY_INIT, RCL_RET_BAD_ALLOC, RCL_RET_ERROR, RCL_RET_INVALID_ARGUMENT, RCL_RET_NODE_INVALID, RCL_RET_OK, RCL_RET_SERVICE_NAME_INVALID, and RCL_RET_UNKNOWN_SUBSTITUTION.

Referenced by rclcpp::GenericService::GenericService(), rcl_node_type_description_service_init(), and rclcpp::Service< ServiceT >::Service().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rcl_service_is_valid()

RCL_PUBLIC bool rcl_service_is_valid ( const rcl_service_t * service )

Check that the service is valid.

The bool returned is false if service is invalid. The bool returned is true otherwise. In the case where false is to be returned, an error message is set. This function cannot fail.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	No
Uses Atomics	No
Lock-Free	Yes

Parameters

[in] service pointer to the rcl service

Returns: true if service is valid, otherwise false

Definition at line 425 of file service.c.

References rcl_service_s::impl.

Referenced by rcl_node_type_description_service_init(), rcl_send_response(), rcl_service_configure_service_introspection(), rcl_service_get_options(), rcl_service_get_rmw_handle(), rcl_service_request_subscription_get_actual_qos(), rcl_service_response_publisher_get_actual_qos(), rcl_service_set_on_new_request_callback(), rcl_take_request_with_info(), and rclcpp::Service< ServiceT >::Service().

Here is the caller graph for this function:

◆ rcl_service_request_subscription_get_actual_qos()

RCL_PUBLIC RCL_WARN_UNUSED const rmw_qos_profile_t* rcl_service_request_subscription_get_actual_qos ( const rcl_service_t * service )

Get the actual qos settings of the service's request subscription.

Used to get the actual qos settings of the service's request subscription. The actual configuration applied when using RMW_*_SYSTEM_DEFAULT can only be resolved after the creation of the service, 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_*_UNKNOWN. The returned struct is only valid as long as the rcl_service_t is valid.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	Yes
Uses Atomics	No
Lock-Free	Yes

Parameters

[in] service pointer to the rcl service

Returns: qos struct if successful, otherwise NULL

Definition at line 436 of file service.c.

References rcl_service_s::impl, and rcl_service_is_valid().

Referenced by rclcpp::ServiceBase::get_request_subscription_actual_qos().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rcl_service_response_publisher_get_actual_qos()

RCL_PUBLIC RCL_WARN_UNUSED const rmw_qos_profile_t* rcl_service_response_publisher_get_actual_qos ( const rcl_service_t * service )

Get the actual qos settings of the service's response publisher.

Used to get the actual qos settings of the service's response publisher. The actual configuration applied when using RMW_*_SYSTEM_DEFAULT can only be resolved after the creation of the service, 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_*_UNKNOWN. The returned struct is only valid as long as the rcl_service_t is valid.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	Yes
Uses Atomics	No
Lock-Free	Yes

Parameters

[in] service pointer to the rcl service

Returns: qos struct if successful, otherwise NULL

Definition at line 445 of file service.c.

References rcl_service_s::impl, and rcl_service_is_valid().

Referenced by rclcpp::ServiceBase::get_response_publisher_actual_qos().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rcl_service_set_on_new_request_callback()

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t rcl_service_set_on_new_request_callback	(	const rcl_service_t *	service,
		rcl_event_callback_t	callback,
		const void *	user_data
	)

Set the on new request callback function for the service.

This API sets the callback function to be called whenever the service is notified about a new request.

See also: rmw_service_set_on_new_request_callback for details about this function.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	Yes
Uses Atomics	Maybe [1]
Lock-Free	Maybe [1]

[1] rmw implementation defined

Parameters

[in]	service	The service on which to set the callback
[in]	callback	The callback to be called when new requests arrive, may be NULL
[in]	user_data	Given to the callback when called later, may be NULL

Returns: RCL_RET_OK if callback was set to the listener, or; RCL_RET_INVALID_ARGUMENT if service is NULL, or; RCL_RET_UNSUPPORTED if the API is not implemented in the dds implementation

Definition at line 454 of file service.c.

References rcl_service_s::impl, RCL_RET_INVALID_ARGUMENT, and rcl_service_is_valid().

Here is the call graph for this function:

◆ rcl_take_request()

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t rcl_take_request	(	const rcl_service_t *	service,
		rmw_request_id_t *	request_header,
		void *	ros_request
	)

Backwards compatibility function to take a pending ROS request using a rcl service.

This version takes a request ID only. See rcl_take_request_with_info() for a full explanation of what this does.

Parameters

[in]	service	the handle to the service from which to take
[in,out]	request_header	ptr to the struct holding the id of the request
[in,out]	ros_request	type-erased ptr to an allocated ROS request message

Returns: RCL_RET_OK if the request was taken, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_SERVICE_INVALID if the service is invalid, or; RCL_RET_BAD_ALLOC if allocating memory failed, or; RCL_RET_SERVICE_TAKE_FAILED if take failed but no error occurred in the middleware, or; RCL_RET_ERROR if an unspecified error occurs.

Definition at line 371 of file service.c.

References rcl_take_request_with_info().

Referenced by rclcpp::ServiceBase::take_type_erased_request().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rcl_take_request_with_info()

RCL_PUBLIC RCL_WARN_UNUSED rcl_ret_t rcl_take_request_with_info	(	const rcl_service_t *	service,
		rmw_service_info_t *	request_header,
		void *	ros_request
	)

Take a pending ROS request using a rcl service.

It is the job of the caller to ensure that the type of the ros_request argument and the type associate with the service, via the type support, match. Passing a different type to rcl_take produces undefined behavior and cannot be checked by this function and therefore no deliberate error will occur.

TODO(jacquelinekay) blocking of take? TODO(jacquelinekay) pre-, during-, and post-conditions for message ownership? TODO(jacquelinekay) is rcl_take_request thread-safe? TODO(jacquelinekay) Should there be an rcl_request_id_t?

The ros_request pointer should point to an already allocated ROS request message struct of the correct type, into which the taken ROS request will be copied if one is available. If taken is false after calling, then the ROS request will be unmodified.

If allocation is required when taking the request, e.g. if space needs to be allocated for a dynamically sized array in the target message, then the allocator given in the service options is used.

request_header is a pointer to pre-allocated a rmw struct containing meta-information about the request (e.g. the sequence number).

Attribute	Adherence
Allocates Memory	Maybe [1]
Thread-Safe	No
Uses Atomics	No
Lock-Free	Yes

[1] only if required when filling the request, avoided for fixed sizes

Parameters

[in]	service	the handle to the service from which to take
[in,out]	request_header	ptr to the struct holding metadata about the request
[in,out]	ros_request	type-erased ptr to an allocated ROS request message

Returns: RCL_RET_OK if the request was taken, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_SERVICE_INVALID if the service is invalid, or; RCL_RET_BAD_ALLOC if allocating memory failed, or; RCL_RET_SERVICE_TAKE_FAILED if take failed but no error occurred in the middleware, or; RCL_RET_ERROR if an unspecified error occurs.

Definition at line 326 of file service.c.

References rcl_service_s::impl, RCL_RET_BAD_ALLOC, RCL_RET_ERROR, RCL_RET_INVALID_ARGUMENT, RCL_RET_OK, RCL_RET_SERVICE_INVALID, RCL_RET_SERVICE_TAKE_FAILED, rcl_service_get_options(), and rcl_service_is_valid().

Referenced by rcl_take_request().

Here is the call graph for this function:

Here is the caller graph for this function:

Classes

Typedefs

Functions

Function Documentation

◆ rcl_get_zero_initialized_service()

◆ rcl_send_response()

◆ rcl_service_configure_service_introspection()

◆ rcl_service_fini()

◆ rcl_service_get_default_options()

◆ rcl_service_get_options()

◆ rcl_service_get_rmw_handle()

◆ rcl_service_get_service_name()

◆ rcl_service_init()

◆ rcl_service_is_valid()

◆ rcl_service_request_subscription_get_actual_qos()

◆ rcl_service_response_publisher_get_actual_qos()

◆ rcl_service_set_on_new_request_callback()

◆ rcl_take_request()

◆ rcl_take_request_with_info()