#include <rmw/names_and_types.h>
#include <rmw/get_topic_names_and_types.h>
#include <rmw/topic_endpoint_info_array.h>
#include "rcutils/time.h"
#include "rcutils/types.h"
#include "rosidl_runtime_c/service_type_support_struct.h"
#include "rcl/macros.h"
#include "rcl/client.h"
#include "rcl/node.h"
#include "rcl/visibility_control.h"

Include dependency graph for graph.h:

Macros
#define	rcl_get_zero_initialized_names_and_types rmw_get_zero_initialized_names_and_types
	Return a zero-initialized rcl_names_and_types_t structure.

#define	rcl_get_zero_initialized_topic_endpoint_info_array rmw_get_zero_initialized_topic_endpoint_info_array
	Return a zero-initialized rcl_topic_endpoint_info_t structure.

#define	rcl_topic_endpoint_info_array_fini rmw_topic_endpoint_info_array_fini
	Finalize a topic_endpoint_info_array_t structure.

Typedefs
typedef rmw_names_and_types_t	rcl_names_and_types_t
	A structure that contains topic names and types.

typedef rmw_topic_endpoint_info_t	rcl_topic_endpoint_info_t

typedef rmw_topic_endpoint_info_array_t	rcl_topic_endpoint_info_array_t
	An array of topic endpoint information.

Functions
rcl_ret_t	rcl_get_publisher_names_and_types_by_node (const rcl_node_t node, rcl_allocator_t allocator, bool no_demangle, const char node_name, const char node_namespace, rcl_names_and_types_t *topic_names_and_types)
	Return a list of topic names and types for publishers associated with a node. More...

rcl_ret_t	rcl_get_subscriber_names_and_types_by_node (const rcl_node_t node, rcl_allocator_t allocator, bool no_demangle, const char node_name, const char node_namespace, rcl_names_and_types_t *topic_names_and_types)
	Return a list of topic names and types for subscriptions associated with a node. More...

rcl_ret_t	rcl_get_service_names_and_types_by_node (const rcl_node_t node, rcl_allocator_t allocator, const char node_name, const char node_namespace, rcl_names_and_types_t *service_names_and_types)
	Return a list of service names and types associated with a node. More...

rcl_ret_t	rcl_get_client_names_and_types_by_node (const rcl_node_t node, rcl_allocator_t allocator, const char node_name, const char node_namespace, rcl_names_and_types_t *service_names_and_types)
	Return a list of service client names and types associated with a node. More...

rcl_ret_t	rcl_get_topic_names_and_types (const rcl_node_t node, rcl_allocator_t allocator, bool no_demangle, rcl_names_and_types_t *topic_names_and_types)
	Return a list of topic names and their types. More...

rcl_ret_t	rcl_get_service_names_and_types (const rcl_node_t node, rcl_allocator_t allocator, rcl_names_and_types_t *service_names_and_types)
	Return a list of service names and their types. More...

rcl_ret_t	rcl_names_and_types_init (rcl_names_and_types_t names_and_types, size_t size, rcl_allocator_t allocator)
	Initialize a rcl_names_and_types_t object. More...

rcl_ret_t	rcl_names_and_types_fini (rcl_names_and_types_t *names_and_types)
	Finalize a rcl_names_and_types_t object. More...

rcl_ret_t	rcl_get_node_names (const rcl_node_t node, rcl_allocator_t allocator, rcutils_string_array_t node_names, rcutils_string_array_t *node_namespaces)
	Return a list of available nodes in the ROS graph. More...

rcl_ret_t	rcl_get_node_names_with_enclaves (const rcl_node_t node, rcl_allocator_t allocator, rcutils_string_array_t node_names, rcutils_string_array_t node_namespaces, rcutils_string_array_t enclaves)
	Return a list of available nodes in the ROS graph, including their enclave names. More...

rcl_ret_t	rcl_count_publishers (const rcl_node_t node, const char topic_name, size_t *count)
	Return the number of publishers on a given topic. More...

rcl_ret_t	rcl_count_subscribers (const rcl_node_t node, const char topic_name, size_t *count)
	Return the number of subscriptions on a given topic. More...

rcl_ret_t	rcl_wait_for_publishers (const rcl_node_t node, rcl_allocator_t allocator, const char topic_name, const size_t count, rcutils_duration_value_t timeout, bool success)
	Wait for there to be a specified number of publishers on a given topic. More...

rcl_ret_t	rcl_wait_for_subscribers (const rcl_node_t node, rcl_allocator_t allocator, const char topic_name, const size_t count, rcutils_duration_value_t timeout, bool success)
	Wait for there to be a specified number of subscribers on a given topic. More...

rcl_ret_t	rcl_get_publishers_info_by_topic (const rcl_node_t node, rcutils_allocator_t allocator, const char topic_name, bool no_mangle, rcl_topic_endpoint_info_array_t publishers_info)
	Return a list of all publishers to a topic. More...

rcl_ret_t	rcl_get_subscriptions_info_by_topic (const rcl_node_t node, rcutils_allocator_t allocator, const char topic_name, bool no_mangle, rcl_topic_endpoint_info_array_t subscriptions_info)
	Return a list of all subscriptions to a topic. More...

rcl_ret_t	rcl_service_server_is_available (const rcl_node_t node, const rcl_client_t client, bool *is_available)
	Check if a service server is available for the given service client. More...

Typedef Documentation

◆ rcl_topic_endpoint_info_t

typedef rmw_topic_endpoint_info_t rcl_topic_endpoint_info_t

A structure that encapsulates the node name, node namespace, topic type, gid, and qos_profile or publishers and subscriptions for a topic.

Function Documentation

◆ rcl_get_publisher_names_and_types_by_node()

rcl_ret_t rcl_get_publisher_names_and_types_by_node	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		bool	no_demangle,
		const char *	node_name,
		const char *	node_namespace,
		rcl_names_and_types_t *	topic_names_and_types
	)

Return a list of topic names and types for publishers associated with a node.

The node parameter must point to a valid node.

The topic_names_and_types parameter must be allocated and zero initialized. This function allocates memory for the returned list of names and types and so it is the callers responsibility to pass topic_names_and_types to rcl_names_and_types_fini() when it is no longer needed. Failing to do so will result in leaked memory.

There may be some demangling that occurs when listing the names from the middleware implementation. If the no_demangle argument is set to true, then this will be avoided and the names will be returned as they appear to the middleware.

See also: rmw_get_topic_names_and_types for more details on no_demangle

The returned names are not automatically remapped by this function. Attempting to create publishers or subscribers using names returned by this function may not result in the desired topic name being used depending on the remap rules in use.

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for strings
[in]	no_demangle	if true, list all topics without any demangling
[in]	node_name	the node name of the topics to return
[in]	node_namespace	the node namespace of the topics to return
[out]	topic_names_and_types	list of topic names and their types

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_NODE_INVALID_NAME if the node name is invalid, or; RCL_RET_NODE_INVALID_NAMESPACE if the node namespace is invalid, or; RCL_RET_NODE_NAME_NON_EXISTENT if the node name wasn't found, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_subscriber_names_and_types_by_node()

rcl_ret_t rcl_get_subscriber_names_and_types_by_node	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		bool	no_demangle,
		const char *	node_name,
		const char *	node_namespace,
		rcl_names_and_types_t *	topic_names_and_types
	)

Return a list of topic names and types for subscriptions associated with a node.

The node parameter must point to a valid node.

The topic_names_and_types parameter must be allocated and zero initialized. This function allocates memory for the returned list of names and types and so it is the callers responsibility to pass topic_names_and_types to rcl_names_and_types_fini() when it is no longer needed. Failing to do so will result in leaked memory.

See also: rcl_get_publisher_names_and_types_by_node for details on the no_demangle parameter.

The returned names are not automatically remapped by this function. Attempting to create publishers or subscribers using names returned by this function may not result in the desired topic name being used depending on the remap rules in use.

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for strings
[in]	no_demangle	if true, list all topics without any demangling
[in]	node_name	the node name of the topics to return
[in]	node_namespace	the node namespace of the topics to return
[out]	topic_names_and_types	list of topic names and their types

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_NODE_INVALID_NAME if the node name is invalid, or; RCL_RET_NODE_INVALID_NAMESPACE if the node namespace is invalid, or; RCL_RET_NODE_NAME_NON_EXISTENT if the node name wasn't found, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_service_names_and_types_by_node()

rcl_ret_t rcl_get_service_names_and_types_by_node	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		const char *	node_name,
		const char *	node_namespace,
		rcl_names_and_types_t *	service_names_and_types
	)

Return a list of service names and types associated with a node.

The node parameter must point to a valid node.

The service_names_and_types parameter must be allocated and zero initialized. This function allocates memory for the returned list of names and types and so it is the callers responsibility to pass service_names_and_types to rcl_names_and_types_fini() when it is no longer needed. Failing to do so will result in leaked memory.

See also: rcl_get_publisher_names_and_types_by_node for details on the no_demangle parameter.

The returned names are not automatically remapped by this function. Attempting to create service clients using names returned by this function may not result in the desired service name being used depending on the remap rules in use.

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for strings
[in]	node_name	the node name of the services to return
[in]	node_namespace	the node namespace of the services to return
[out]	service_names_and_types	list of service names and their types

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_NODE_INVALID_NAME if the node name is invalid, or; RCL_RET_NODE_INVALID_NAMESPACE if the node namespace is invalid, or; RCL_RET_NODE_NAME_NON_EXISTENT if the node name wasn't found, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_client_names_and_types_by_node()

rcl_ret_t rcl_get_client_names_and_types_by_node	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		const char *	node_name,
		const char *	node_namespace,
		rcl_names_and_types_t *	service_names_and_types
	)

Return a list of service client names and types associated with a node.

The node parameter must point to a valid node.

The service_names_and_types parameter must be allocated and zero initialized. This function allocates memory for the returned list of names and types and so it is the callers responsibility to pass service_names_and_types to rcl_names_and_types_fini() when it is no longer needed. Failing to do so will result in leaked memory.

See also: rcl_get_publisher_names_and_types_by_node for details on the no_demangle parameter.

The returned names are not automatically remapped by this function. Attempting to create service servers using names returned by this function may not result in the desired service name being used depending on the remap rules in use.

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for strings
[in]	node_name	the node name of the services to return
[in]	node_namespace	the node namespace of the services to return
[out]	service_names_and_types	list of service client names and their types

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_NODE_INVALID_NAME if the node name is invalid, or; RCL_RET_NODE_INVALID_NAMESPACE if the node namespace is invalid, or; RCL_RET_NODE_NAME_NON_EXISTENT if the node name wasn't found, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_topic_names_and_types()

rcl_ret_t rcl_get_topic_names_and_types	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		bool	no_demangle,
		rcl_names_and_types_t *	topic_names_and_types
	)

Return a list of topic names and their types.

The node parameter must point to a valid node.

The topic_names_and_types parameter must be allocated and zero initialized. This function allocates memory for the returned list of names and types and so it is the callers responsibility to pass topic_names_and_types to rcl_names_and_types_fini() when it is no longer needed. Failing to do so will result in leaked memory.

See also: rcl_get_publisher_names_and_types_by_node for details on the no_demangle parameter.

The returned names are not automatically remapped by this function. Attempting to create publishers or subscribers using names returned by this function may not result in the desired topic name being used depending on the remap rules in use.

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for strings
[in]	no_demangle	if true, list all topics without any demangling
[out]	topic_names_and_types	list of topic names and their types

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_NODE_INVALID_NAME if the node name is invalid, or; RCL_RET_NODE_INVALID_NAMESPACE if the node namespace is invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_service_names_and_types()

rcl_ret_t rcl_get_service_names_and_types	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		rcl_names_and_types_t *	service_names_and_types
	)

Return a list of service names and their types.

The node parameter must point to a valid node.

The service_names_and_types parameter must be allocated and zero initialized. This function allocates memory for the returned list of names and types and so it is the callers responsibility to pass service_names_and_types to rcl_names_and_types_fini() when it is no longer needed. Failing to do so will result in leaked memory.

The returned names are not automatically remapped by this function. Attempting to create clients or services using names returned by this function may not result in the desired service name being used depending on the remap rules in use.

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for strings
[out]	service_names_and_types	list of service names and their types

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_names_and_types_init()

rcl_ret_t rcl_names_and_types_init	(	rcl_names_and_types_t *	names_and_types,
		size_t	size,
		rcl_allocator_t *	allocator
	)

Initialize a rcl_names_and_types_t object.

This function initializes the string array for the names and allocates space for all the string arrays for the types according to the given size, but it does not initialize the string array for each set of types. However, the string arrays for each set of types is zero initialized.

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

Parameters

[in,out]	names_and_types	object to be initialized
[in]	size	the number of names and sets of types to be stored
[in]	allocator	to be used to allocate and deallocate memory

Returns: RCL_RET_OK on success, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_BAD_ALLOC if memory allocation fails, or; RCL_RET_ERROR when an unspecified error occurs.

◆ rcl_names_and_types_fini()

rcl_ret_t rcl_names_and_types_fini ( rcl_names_and_types_t * names_and_types )

Finalize a rcl_names_and_types_t object.

The object is populated when given to one of the rcl_get_*_names_and_types() functions. This function reclaims any resources allocated during population.

The names_and_types parameter must not be NULL, and must point to an already allocated rcl_names_and_types_t struct that was previously passed to a successful rcl_get_*_names_and_types() function call.

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

Parameters

[in,out] names_and_types struct to be finalized

Returns: RCL_RET_OK if successful, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_node_names()

rcl_ret_t rcl_get_node_names	(	const rcl_node_t *	node,
		rcl_allocator_t	allocator,
		rcutils_string_array_t *	node_names,
		rcutils_string_array_t *	node_namespaces
	)

Return a list of available nodes in the ROS graph.

The node parameter must point to a valid node.

The node_names parameter must be allocated and zero initialized. node_names is the output for this function, and contains allocated memory. Use rcutils_get_zero_initialized_string_array() for initializing an empty rcutils_string_array_t struct. This node_names struct should therefore be passed to rcutils_string_array_fini() when it is no longer needed. Failing to do so will result in leaked memory.

Example:

rcutils_string_array_t node_names =
  rcutils_get_zero_initialized_string_array();
rcl_ret_t ret = rcl_get_node_names(node, &node_names);
if (ret != RCL_RET_OK) {
  // ... error handling
}
// ... use the node_names struct, and when done:
rcutils_ret_t rcutils_ret = rcutils_string_array_fini(&node_names);
if (rcutils_ret != RCUTILS_RET_OK) {
  // ... error handling
}

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	used to control allocation and deallocation of names
[out]	node_names	struct storing discovered node names
[out]	node_namespaces	struct storing discovered node namespaces

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_BAD_ALLOC if an error occurred while allocating memory, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_NODE_INVALID_NAME if a node with an invalid name is detected, or; RCL_RET_NODE_INVALID_NAMESPACE if a node with an invalid namespace is detected, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_node_names_with_enclaves()

rcl_ret_t rcl_get_node_names_with_enclaves	(	const rcl_node_t *	node,
		rcl_allocator_t	allocator,
		rcutils_string_array_t *	node_names,
		rcutils_string_array_t *	node_namespaces,
		rcutils_string_array_t *	enclaves
	)

Return a list of available nodes in the ROS graph, including their enclave names.

An rcl_get_node_names() equivalent, but including in its output the enclave name the node is using.

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

[1] RMW implementation in use may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	used to control allocation and deallocation of names
[out]	node_names	struct storing discovered node names
[out]	node_namespaces	struct storing discovered node namespaces
[out]	enclaves	struct storing discovered node enclaves

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_BAD_ALLOC if an error occurred while allocating memory, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_count_publishers()

rcl_ret_t rcl_count_publishers	(	const rcl_node_t *	node,
		const char *	topic_name,
		size_t *	count
	)

Return the number of publishers on a given topic.

The node parameter must point to a valid node.

The topic_name parameter must not be NULL, and must not be an empty string. It should also follow the topic name rules.

Todo:: TODO(wjwwood): link to the topic name rules.

The count parameter must point to a valid bool. The count parameter is the output for this function and will be set.

In the event that error handling needs to allocate memory, this function will try to use the node's allocator.

The topic name is not automatically remapped by this function. If there is a publisher created with topic name foo and remap rule foo:=bar then calling this with topic_name set to bar will return a count of 1, and with topic_name set to foo will return a count of 0. /sa rcl_remap_topic_name()

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	topic_name	the name of the topic in question
[out]	count	number of publishers on the given topic

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_count_subscribers()

rcl_ret_t rcl_count_subscribers	(	const rcl_node_t *	node,
		const char *	topic_name,
		size_t *	count
	)

Return the number of subscriptions on a given topic.

The node parameter must point to a valid node.

The topic_name parameter must not be NULL, and must not be an empty string. It should also follow the topic name rules.

Todo:: TODO(wjwwood): link to the topic name rules.

The count parameter must point to a valid bool. The count parameter is the output for this function and will be set.

In the event that error handling needs to allocate memory, this function will try to use the node's allocator.

The topic name is not automatically remapped by this function. If there is a subscriber created with topic name foo and remap rule foo:=bar then calling this with topic_name set to bar will return a count of 1, and with topic_name set to foo will return a count of 0. /sa rcl_remap_topic_name()

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	topic_name	the name of the topic in question
[out]	count	number of subscriptions on the given topic

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_wait_for_publishers()

rcl_ret_t rcl_wait_for_publishers	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		const char *	topic_name,
		const size_t	count,
		rcutils_duration_value_t	timeout,
		bool *	success
	)

Wait for there to be a specified number of publishers on a given topic.

The node parameter must point to a valid node. The nodes graph guard condition is used by this function, and therefore the caller should take care not to use the guard condition concurrently in any other wait sets.

The allocator parameter must point to a valid allocator.

The topic_name parameter must not be NULL, and must not be an empty string. It should also follow the topic name rules.

This function blocks and will return when the number of publishers for topic_name is greater than or equal to the count parameter, or the specified timeout is reached.

The timeout parameter is in nanoseconds. The timeout is based on system time elapsed. A negative value disables the timeout (i.e. this function blocks until the number of publishers is greater than or equals to count).

The success parameter must point to a valid bool. The success parameter is the output for this function and will be set.

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	to allocate space for the rcl_wait_set_t used to wait for graph events
[in]	topic_name	the name of the topic in question
[in]	count	number of publishers to wait for
[in]	timeout	maximum duration to wait for publishers
[out]	success	`true` if the number of publishers is equal to or greater than count, or `false` if a timeout occurred waiting for publishers.

Returns: RCL_RET_OK if there was no errors, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_TIMEOUT if a timeout occurs before the number of publishers is detected, or; RCL_RET_ERROR if an unspecified error occurred.

◆ rcl_wait_for_subscribers()

rcl_ret_t rcl_wait_for_subscribers	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		const char *	topic_name,
		const size_t	count,
		rcutils_duration_value_t	timeout,
		bool *	success
	)

Wait for there to be a specified number of subscribers on a given topic.

See also: rcl_wait_for_publishers

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	to allocate space for the rcl_wait_set_t used to wait for graph events
[in]	topic_name	the name of the topic in question
[in]	count	number of subscribers to wait for
[in]	timeout	maximum duration to wait for subscribers
[out]	success	`true` if the number of subscribers is equal to or greater than count, or `false` if a timeout occurred waiting for subscribers.

Returns: RCL_RET_OK if there was no errors, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_TIMEOUT if a timeout occurs before the number of subscribers is detected, or; RCL_RET_ERROR if an unspecified error occurred.

◆ rcl_get_publishers_info_by_topic()

rcl_ret_t rcl_get_publishers_info_by_topic	(	const rcl_node_t *	node,
		rcutils_allocator_t *	allocator,
		const char *	topic_name,
		bool	no_mangle,
		rcl_topic_endpoint_info_array_t *	publishers_info
	)

Return a list of all publishers to a topic.

The node parameter must point to a valid node.

The topic_name parameter must not be NULL.

When the no_mangle parameter is true, the provided topic_name should be a valid topic name for the middleware (useful when combining ROS with native middleware (e.g. DDS) apps). When the no_mangle parameter is false, the provided topic_name should follow ROS topic name conventions. In either case, the topic name should always be fully qualified.

Each element in the publishers_info array will contain the node name, node namespace, topic type, gid and the qos profile of the publisher. It is the responsibility of the caller to ensure that publishers_info parameter points to a valid struct of type rcl_topic_endpoint_info_array_t. The count field inside the struct must be set to 0 and the info_array field inside the struct must be set to null.

See also: rmw_get_zero_initialized_topic_endpoint_info_array

The allocator will be used to allocate memory to the info_array member inside of publishers_info. Moreover, every const char * member inside of rmw_topic_endpoint_info_t will be assigned a copied value on allocated memory.

See also: rmw_topic_endpoint_info_set_node_name and the likes. However, it is the responsibility of the caller to reclaim any allocated resources to publishers_info to avoid leaking memory.; rmw_topic_endpoint_info_array_fini

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for the array inside publishers_info
[in]	topic_name	the name of the topic in question
[in]	no_mangle	if `true`, `topic_name` needs to be a valid middleware topic name, otherwise it should be a valid ROS topic name
[out]	publishers_info	a struct representing a list of publisher information

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_BAD_ALLOC if memory allocation fails, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_subscriptions_info_by_topic()

rcl_ret_t rcl_get_subscriptions_info_by_topic	(	const rcl_node_t *	node,
		rcutils_allocator_t *	allocator,
		const char *	topic_name,
		bool	no_mangle,
		rcl_topic_endpoint_info_array_t *	subscriptions_info
	)

Return a list of all subscriptions to a topic.

The node parameter must point to a valid node.

The topic_name parameter must not be NULL.

When the no_mangle parameter is true, the provided topic_name should be a valid topic name for the middleware (useful when combining ROS with native middleware (e.g. DDS) apps). When the no_mangle parameter is false, the provided topic_name should follow ROS topic name conventions. In either case, the topic name should always be fully qualified.

Each element in the subscriptions_info array will contain the node name, node namespace, topic type, gid and the qos profile of the subscription. It is the responsibility of the caller to ensure that subscriptions_info parameter points to a valid struct of type rcl_topic_endpoint_info_array_t. The count field inside the struct must be set to 0 and the info_array field inside the struct must be set to null.

See also: rmw_get_zero_initialized_topic_endpoint_info_array

The allocator will be used to allocate memory to the info_array member inside of subscriptions_info. Moreover, every const char * member inside of rmw_topic_endpoint_info_t will be assigned a copied value on allocated memory.

See also: rmw_topic_endpoint_info_set_node_name and the likes. However, it is the responsibility of the caller to reclaim any allocated resources to subscriptions_info to avoid leaking memory.; rmw_topic_endpoint_info_array_fini

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for the array inside publishers_info
[in]	topic_name	the name of the topic in question
[in]	no_mangle	if `true`, `topic_name` needs to be a valid middleware topic name, otherwise it should be a valid ROS topic name
[out]	subscriptions_info	a struct representing a list of subscriptions information

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_BAD_ALLOC if memory allocation fails, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_service_server_is_available()

rcl_ret_t rcl_service_server_is_available	(	const rcl_node_t *	node,
		const rcl_client_t *	client,
		bool *	is_available
	)

Check if a service server is available for the given service client.

This function will return true for is_available if there is a service server available for the given client.

The node parameter must point to a valid node.

The client parameter must point to a valid client.

The given client and node must match, i.e. the client must have been created using the given node.

The is_available parameter must not be NULL, and must point a bool variable. The result of the check will be stored in the is_available parameter.

In the event that error handling needs to allocate memory, this function will try to use the node's allocator.

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

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	client	the handle to the service client being queried
[out]	is_available	set to true if there is a service server available, else false

Returns: RCL_RET_OK if the check was made successfully (regardless of the service readiness), or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

Macros

Typedefs

Functions

Typedef Documentation

◆ rcl_topic_endpoint_info_t

Function Documentation

◆ rcl_get_publisher_names_and_types_by_node()

◆ rcl_get_subscriber_names_and_types_by_node()

◆ rcl_get_service_names_and_types_by_node()

◆ rcl_get_client_names_and_types_by_node()

◆ rcl_get_topic_names_and_types()

◆ rcl_get_service_names_and_types()

◆ rcl_names_and_types_init()

◆ rcl_names_and_types_fini()

◆ rcl_get_node_names()

◆ rcl_get_node_names_with_enclaves()

◆ rcl_count_publishers()

◆ rcl_count_subscribers()

◆ rcl_wait_for_publishers()

◆ rcl_wait_for_subscribers()

◆ rcl_get_publishers_info_by_topic()

◆ rcl_get_subscriptions_info_by_topic()

◆ rcl_service_server_is_available()