rcl/rcl_action/include/rcl_action/action_client.h
William Woodall 0518125724 add wait_for_action_server() for action clients (#349)
Signed-off-by: William Woodall <william@osrfoundation.org>
2018-12-06 18:57:17 -08:00

742 lines
30 KiB
C

// Copyright 2018 Open Source Robotics Foundation, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef RCL_ACTION__ACTION_CLIENT_H_
#define RCL_ACTION__ACTION_CLIENT_H_
#ifdef __cplusplus
extern "C"
{
#endif
#include "rcl_action/types.h"
#include "rcl_action/visibility_control.h"
#include "rcl/macros.h"
#include "rcl/node.h"
/// Internal action client implementation struct.
struct rcl_action_client_impl_t;
/// Structure which encapsulates a ROS action client.
typedef struct rcl_action_client_t
{
struct rcl_action_client_impl_t * impl;
} rcl_action_client_t;
/// Options available for a rcl_action_client_t.
typedef struct rcl_action_client_options_t
{
/// Middleware quality of service settings for the action client.
rmw_qos_profile_t goal_service_qos;
rmw_qos_profile_t result_service_qos;
rmw_qos_profile_t cancel_service_qos;
rmw_qos_profile_t feedback_topic_qos;
rmw_qos_profile_t status_topic_qos;
/// Custom allocator for the action client, used for incidental allocations.
/** For default behavior (malloc/free), see: rcl_get_default_allocator() */
rcl_allocator_t allocator;
} rcl_action_client_options_t;
/// Return a rcl_action_client_t struct with members set to `NULL`.
/**
* Should be called to get a null rcl_action_client_t before passing to
* rcl_action_client_init().
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_action_client_t
rcl_action_get_zero_initialized_client(void);
/// Initialize a rcl_action_client_t.
/**
* After calling this function on a rcl_action_client_t, it can be used to send
* goals of the given type to the given topic using rcl_action_send_goal_request().
* If a goal request is sent to a (possibly remote) server and if the server
* sends a response, the client can access the response with
* rcl_take_goal_response() once the response is available.
*
* After a goal request has been accepted, the rcl_action_client_t associated with the
* goal can perform the following operations:
*
* - Send a request for the result with rcl_action_send_result_request().
* If the server sends a response when the goal terminates, the result can be accessed
* with rcl_action_take_result_response(), once the response is available.
* - Send a cancel request for the goal with rcl_action_send_cancel_request().
* If the server sends a response to a cancel request, the client can access the
* response with rcl_action_take_cancel_response() once the response is available.
* - Take feedback about the goal with rcl_action_take_feedback().
*
* A rcl_action_client_t can be used to access the current status of all accepted goals
* communicated by the action server with rcl_action_take_status().
*
* The given rcl_node_t must be valid and the resulting rcl_action_client_t is
* only valid as long as the given rcl_node_t remains valid.
*
* The rosidl_action_type_support_t is obtained on a per .action type basis.
* When the user defines a ROS action, code is generated which provides the
* required rosidl_action_type_support_t object.
* This object can be obtained using a language appropriate mechanism.
*
* \todo TODO(jacobperron) write these instructions once and link to it instead
*
* For C, a macro can be used (for example `example_interfaces/Fibonacci`):
*
* ```c
* #include <rosidl_generator_c/action_type_support_struct.h>
* #include <example_interfaces/action/fibonacci.h>
* const rosidl_action_type_support_t * ts =
* ROSIDL_GET_ACTION_TYPE_SUPPORT(example_interfaces, Fibonacci);
* ```
*
* For C++, a template function is used:
*
* ```cpp
* #include <rosidl_generator_cpp/action_type_support.hpp>
* #include <example_interfaces/action/fibonacci.h>
* using rosidl_typesupport_cpp::get_action_type_support_handle;
* const rosidl_action_type_support_t * ts =
* get_action_type_support_handle<example_interfaces::action::Fibonacci>();
* ```
*
* The rosidl_action_type_support_t object contains action type specific
* information used to send or take goals, results, and feedback.
*
* The topic name must be a c string that follows the topic and service name
* format rules for unexpanded names, also known as non-fully qualified names:
*
* \see rcl_expand_topic_name
*
* The options struct allows the user to set the quality of service settings as
* well as a custom allocator that is used when initializing/finalizing the
* client to allocate space for incidentals, e.g. the action client name string.
*
* Expected usage (for C action clients):
*
* ```c
* #include <rcl/rcl.h>
* #include <rcl_action/action_client.h>
* #include <rosidl_generator_c/action_type_support_struct.h>
* #include <example_interfaces/action/fibonacci.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_action_type_support_t * ts =
* ROSIDL_GET_ACTION_TYPE_SUPPORT(example_interfaces, Fibonacci);
* rcl_action_client_t action_client = rcl_action_get_zero_initialized_client();
* rcl_action_client_options_t action_client_ops = rcl_action_client_get_default_options();
* ret = rcl_action_client_init(&action_client, &node, ts, "fibonacci", &action_client_ops);
* // ... error handling, and on shutdown do finalization:
* ret = rcl_action_client_fini(&action_client, &node);
* // ... error handling for rcl_action_client_fini()
* ret = rcl_node_fini(&node);
* // ... error handling for rcl_node_fini()
* ```
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | Yes
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[out] action_client a preallocated, zero-initialized action client structure
* to be initialized
* \param[in] node valid rcl node handle
* \param[in] type_support type support object for the action's type
* \param[in] action_name the name of the action
* \param[in] options action_client options, including quality of service settings
* \return `RCL_RET_OK` if action_client was initialized successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_NODE_INVALID` if the node is invalid, or
* \return `RCL_RET_ALREADY_INIT` if the action client is already initialized, or
* \return `RCL_RET_BAD_ALLOC` if allocating memory failed, or
* \return `RCL_RET_ACTION_NAME_INVALID` if the given action name is invalid, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_client_init(
rcl_action_client_t * action_client,
rcl_node_t * node,
const rosidl_action_type_support_t * type_support,
const char * action_name,
const rcl_action_client_options_t * options);
/// Finalize a rcl_action_client_t.
/**
* After calling, the node will no longer listen for goals for this action client
* (assuming this is the only action client of this type in this node).
*
* After calling, calls to rcl_wait(), rcl_action_send_goal_request(),
* rcl_action_take_goal_response(), rcl_action_send_cancel_request(),
* rcl_action_take_cancel_response(), rcl_action_send_result_request(),
* rcl_action_take_result_response(), rcl_action_take_feedback(), and
* rcl_action_take_status(), will fail when using this action client.
*
* Additionally, rcl_wait() will be interrupted if currently blocking.
*
* The given node handle is still valid.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | Yes
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[inout] action_client handle to the action_client to be deinitialized
* \param[in] node handle to the node used to create the action client
* \return `RCL_RET_OK` if the action client was deinitialized successfully, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_NODE_INVALID` if the node is invalid, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_client_fini(rcl_action_client_t * action_client, rcl_node_t * node);
/// Return the default action client options in a rcl_action_client_options_t.
/**
* The defaults are:
*
* - goal_service_qos = rmw_qos_profile_services_default;
* - result_service_qos = rmw_qos_profile_services_default;
* - cancel_service_qos = rmw_qos_profile_services_default;
* - feedback_topic_qos = rmw_qos_profile_default;
* - status_topic_qos = rcl_action_qos_profile_status_default;
* - allocator = rcl_get_default_allocator()
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_action_client_options_t
rcl_action_client_get_default_options(void);
/// Check if an action server is available for the given action client.
/**
* This function will return true for is_available if there is an action server
* available for the given action client.
*
* The node parameter must not be `NULL`, and must point to a valid node.
*
* The client parameter must not be `NULL`, and 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.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | Yes
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Maybe [1]
* <i>[1] implementation may need to protect the data structure with a lock</i>
*
* \param[in] node the handle to the node being used to query the ROS graph
* \param[in] client the handle to the action client being queried
* \param[out] is_available set to true if there is an action server available, else false
* \return `RCL_RET_OK` if successful (regardless of the action server availability), or
* \return `RCL_RET_NODE_INVALID` if the node is invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_server_is_available(
const rcl_node_t * node,
const rcl_action_client_t * client,
bool * is_available);
/// Send a ROS goal using a rcl_action_client_t.
/**
* This is a non-blocking call.
*
* The caller is responsible for ensuring that the type of `ros_goal_request`
* and the type associate with the client (via the type support) match.
* Passing a different type produces undefined behavior and cannot be checked
* by this function and therefore no deliberate error will occur.
*
* The ROS goal message given by the `ros_goal_request` void pointer is always
* owned by the calling code, but should remain constant during execution of this
* function. i.e. Before and after calling rcl_action_send_goal_request() the
* `ros_goal_request` message can change, but it cannot be changed during the call to
* rcl_action_send_goal_request().
* The same `ros_goal_request` can be passed to multiple calls of this function
* simultaneously, even if the action clients differ.
*
* This function is thread safe so long as access to both the rcl_action_client_t
* and the `ros_goal_request` are synchronized.
* That means that calling rcl_action_send_goal_request() from multiple threads is allowed,
* but calling rcl_action_send_goal_request() at the same time as non-thread safe action
* client functions is not, e.g. calling rcl_action_send_goal_request() and
* rcl_action_client_fini() concurrently is not allowed.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | No
* Thread-Safe | Yes [1]
* Uses Atomics | No
* Lock-Free | Yes
* <i>[1] for unique pairs of clients and goals, see above for more</i>
*
* \param[in] action_client handle to the client that will make the goal request
* \param[in] ros_goal_request pointer to the ROS goal message
* \param[out] sequence_number pointer to the goal request sequence number
* \return `RCL_RET_OK` if the request was sent successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the client is invalid, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_send_goal_request(
const rcl_action_client_t * action_client,
const void * ros_goal_request,
int64_t * sequence_number);
/// Take a response for a goal request from an action server using a rcl_action_client_t.
/**
* \todo TODO(jacobperron) blocking of take?
*
* \todo TODO(jacobperron) pre-, during-, and post-conditions for message ownership?
*
* \todo TODO(jacobperron) is this thread-safe?
*
* The caller is responsible for ensuring that the type of `ros_goal_response`
* and the type associate with the client (via the type support) match.
* Passing a different type produces undefined behavior and cannot be checked
* by this function and therefore no deliberate error will occur.
*
* The caller must provide a pointer to an allocated message for the `ros_goal_response`.
* If the take is successful, this function will populate the fields of `ros_goal_response`.
* The ROS message given by the `ros_goal_response` void pointer is always
* owned by the calling code, but should remain constant during execution of this
* function. i.e. Before and after calling rcl_action_send_goal_response() the
* `ros_goal_response` message can change, but it cannot be changed during the call to
* rcl_action_send_goal_response().
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | No
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[in] action_client handle to the client that will take the goal response
* \param[out] response_header pointer to the goal response header
* \param[out] ros_goal_response pointer to the response of a goal request
* \return `RCL_RET_OK` if the response was taken successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_ACTION_CLIENT_TAKE_FAILED` if take failed but no error occurred
* in the middleware, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_take_goal_response(
const rcl_action_client_t * action_client,
rmw_request_id_t * response_header,
void * ros_goal_response);
/// Take a ROS feedback message for an active goal associated with a rcl_action_client_t.
/**
* The caller is responsible for ensuring that the type of `ros_feedback`
* and the type associate with the client (via the type support) match.
* Passing a different type produces undefined behavior and cannot be checked
* by this function and therefore no deliberate error will occur.
*
* \todo TODO(jacobperron) blocking of take?
*
* \todo TODO(jacobperron) pre-, during-, and post-conditions for message ownership?
*
* \todo TODO(jacobperron) is this thread-safe?
*
* `ros_feedback` should point to a preallocated ROS message struct of the
* correct type.
* If feedback is successfully taken, the feedback message is copied to into the
* `ros_feedback` struct.
*
* If allocation is required when taking the feedback, e.g. if space needs to
* be allocated for a dynamically sized array in the target message, then the
* allocator given in the action client options is used.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | Maybe [1]
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
* <i>[1] only if required when filling the feedback message, avoided for fixed sizes</i>
*
* \param[in] action_client handle to the client that will take action feedback
* \param[out] ros_feedback pointer to the ROS feedback message.
* \return `RCL_RET_OK` if the response was taken successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_BAD_ALLOC` if allocating memory failed, or
* \return `RCL_RET_ACTION_CLIENT_TAKE_FAILED` if take failed but no error occurred
* in the middleware, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_take_feedback(
const rcl_action_client_t * action_client,
void * ros_feedback);
/// Take a ROS status message using a rcl_action_client_t.
/**
* The caller is responsible for ensuring that the type of `ros_status_array`
* and the type associate with the client (via the type support) match.
* Passing a different type produces undefined behavior and cannot be checked
* by this function and therefore no deliberate error will occur.
*
* \todo TODO(jacobperron) blocking of take?
*
* \todo TODO(jacobperron) pre-, during-, and post-conditions for message ownership?
*
* \todo TODO(jacobperron) is this thread-safe?
*
* The caller is responsible for allocating the `ros_status_array` struct with a
* zero-initialization (the internal array should not be allocated).
* If there is a successful take, then `ros_status_array` is populated
* with the allocator given in the action client options.
* It is the callers responsibility to deallocate the `ros_status_array` struct using
* the allocator given in the action client options.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | Yes
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[in] action_client handle to the client that will take status message
* \param[out] ros_status_array pointer to ROS aciton_msgs/StatusArray message that
* will be populated with information about goals that have accepted the cancel request.
* \return `RCL_RET_OK` if the response was taken successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_BAD_ALLOC` if allocating memory failed, or
* \return `RCL_RET_ACTION_CLIENT_TAKE_FAILED` if take failed but no error occurred
* in the middleware, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_take_status(
const rcl_action_client_t * action_client,
void * ros_status_array);
/// Send a request for the result of a completed goal associated with a rcl_action_client_t.
/**
* This is a non-blocking call.
*
* The caller is responsible for ensuring that the type of `ros_result_request`
* and the type associate with the client (via the type support) match.
* Passing a different type produces undefined behavior and cannot be checked
* by this function and therefore no deliberate error will occur.
*
* The ROS message given by the `ros_result_request` void pointer is always
* owned by the calling code, but should remain constant during execution of this
* function. i.e. Before and after calling rcl_action_send_result_request() the
* `ros_result_request` message can change, but it cannot be changed during the call to
* rcl_action_send_result_request().
* The same `ros_result_request` can be passed to multiple calls of this function
* simultaneously, even if the action clients differ.
*
* This function is thread safe so long as access to both the rcl_action_client_t
* and the `ros_result_request` are synchronized.
* That means that calling rcl_action_send_result_request() from multiple threads is allowed,
* but calling rcl_action_send_result_request() at the same time as non-thread safe action
* client functions is not, e.g. calling rcl_action_send_result_request() and
* rcl_action_client_fini() concurrently is not allowed.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | No
* Thread-Safe | Yes [1]
* Uses Atomics | No
* Lock-Free | Yes
* <i>[1] for unique pairs of clients and result requests, see above for more</i>
* \param[in] action_client handle to the client that will send the result request
* \param[in] ros_result_request pointer to a ROS result request message
* \param[out] sequence_number pointer to the result request sequence number
* \return `RCL_RET_OK` if the request was sent successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_send_result_request(
const rcl_action_client_t * action_client,
const void * ros_result_request,
int64_t * sequence_number);
/// Take a ROS result message for a completed goal associated with a rcl_action_client_t.
/**
* \todo TODO(jacobperron) blocking of take?
*
* \todo TODO(jacobperron) pre-, during-, and post-conditions for message ownership?
*
* \todo TODO(jacobperron) is this thread-safe?
*
* The caller is responsible for ensuring that the type of `ros_result_response`
* and the type associate with the client (via the type support) match.
* Passing a different type produces undefined behavior and cannot be checked
* by this function and therefore no deliberate error will occur.
*
* The caller must provide a pointer to an allocated message for the `ros_result_response`.
* If the take is successful, this function will populate the fields of `ros_result_response`.
* The ROS message given by the `ros_result_response` void pointer is always
* owned by the calling code, but should remain constant during execution of this
* function. i.e. Before and after calling rcl_action_take_result_response() the
* `ros_result_response` message can change, but it cannot be changed during the call to
* rcl_action_take_result_response().
*
* If allocation is required when taking the result, e.g. if space needs to
* be allocated for a dynamically sized array in the target message, then the
* allocator given in the action client options is used.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | Maybe [1]
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
* <i>[1] only if required when filling the result response message, avoided for fixed sizes</i>
*
* \param[in] action_client handle to the client that will take the result response
* \param[out] response_header pointer to the result response header
* \param[out] ros_result_response preallocated, zero-initialized, struct where the ROS
* result message is copied.
* \return `RCL_RET_OK` if the response was taken successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_BAD_ALLOC` if allocating memory failed, or
* \return `RCL_RET_ACTION_CLIENT_TAKE_FAILED` if take failed but no error occurred
* in the middleware, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_take_result_response(
const rcl_action_client_t * action_client,
rmw_request_id_t * response_header,
void * ros_result);
/// Send a cancel request for a goal using a rcl_action_client_t.
/**
* This is a non-blocking call.
*
* The caller is responsible for ensuring that the type of `ros_cancel_request`
* and the type associate with the client (via the type support) match.
* Passing a different type produces undefined behavior and cannot be checked
* by this function and therefore no deliberate error will occur.
*
* The following cancel policy applies based on the goal ID and the timestamp provided
* by the `ros_cancel_request` message:
*
* - If the goal ID is zero and timestamp is zero, cancel all goals.
* - If the goal ID is zero and timestamp is not zero, cancel all goals accepted
* at or before the timestamp.
* - If the goal ID is not zero and timestamp is zero, cancel the goal with the
* given ID regardless of the time it was accepted.
* - If the goal ID is not zero and timestamp is not zero, cancel the goal with the
* given ID and all goals accepted at or before the timestamp.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | No
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[in] action_client handle to the client that will make the cancel request
* \param[in] ros_cancel_request pointer the ROS cancel request message
* \param[out] sequence_number pointer to the cancel request sequence number
* \return `RCL_RET_OK` if the response was taken successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_send_cancel_request(
const rcl_action_client_t * action_client,
const void * ros_cancel_request,
int64_t * sequence_number);
/// Take a cancel response using a rcl_action_client_t.
/**
* \todo TODO(jacobperron) blocking of take?
*
* \todo TODO(jacobperron) pre-, during-, and post-conditions for message ownership?
*
* \todo TODO(jacobperron) is this thread-safe?
*
* The caller is responsible for ensuring that the type of `ros_cancel_response`
* and the type associate with the client (via the type support) match.
* Passing a different type produces undefined behavior and cannot be checked
* by this function and therefore no deliberate error will occur.
* The caller is responsible for allocating the `ros_cancel_response` message
* with a zero-initialization (the internal array should not be allocated).
* If a successful response is taken, then `ros_cancel_response` is populated
* using the allocator given in the action client options.
* It is the callers responsibility to deallocate `ros_cancel_response` using
* the allocator given in the action client options.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | Yes
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[in] action_client handle to the client that will take the cancel response
* \param[out] request_header pointer to the cancel response header
* \param[out] ros_cancel_response a zero-initialized ROS cancel response message where
* the cancel response is copied.
* \return `RCL_RET_OK` if the response was taken successfully, or
* \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
* \return `RCL_RET_ACTION_CLIENT_INVALID` if the action client is invalid, or
* \return `RCL_RET_BAD_ALLOC` if allocating memory failed, or
* \return `RCL_RET_ACTION_CLIENT_TAKE_FAILED` if take failed but no error occurred
* in the middleware, or
* \return `RCL_RET_ERROR` if an unspecified error occurs.
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
rcl_ret_t
rcl_action_take_cancel_response(
const rcl_action_client_t * action_client,
rmw_request_id_t * response_header,
void * ros_cancel_response);
/// Get the name of the action for a rcl_action_client_t.
/**
* This function returns the action client's name string.
* This function can fail, and therefore return `NULL`, if the:
* - action client is `NULL`
* - action client is invalid (never called init, called fini, or invalid)
*
* The returned string is only valid as long as the action client 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.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | No
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[in] action_client the pointer to the action client
* \return name string if successful, otherwise `NULL`
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
const char *
rcl_action_client_get_action_name(const rcl_action_client_t * action_client);
/// Return the options for a rcl_action_client_t.
/**
* This function returns the action client's internal options struct.
* This function can fail, and therefore return `NULL`, if the:
* - action client is `NULL`
* - action client is invalid (never called init, called fini, or invalid)
*
* The returned struct is only valid as long as the action client is valid.
* The values in the struct may change if the action client's options change,
* and therefore copying the struct is recommended if this is a concern.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | No
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[in] action_client pointer to the action client
* \return options struct if successful, otherwise `NULL`
*/
RCL_ACTION_PUBLIC
RCL_WARN_UNUSED
const rcl_action_client_options_t *
rcl_action_client_get_options(const rcl_action_client_t * action_client);
/// Check that a rcl_action_client_t is valid.
/**
* The bool returned is `false` if `action_client` 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.
*
* <hr>
* Attribute | Adherence
* ------------------ | -------------
* Allocates Memory | No
* Thread-Safe | No
* Uses Atomics | No
* Lock-Free | Yes
*
* \param[in] action_client pointer to the rcl action client
* \return `true` if `action_client` is valid, otherwise `false`
*/
RCL_ACTION_PUBLIC
bool
rcl_action_client_is_valid(
const rcl_action_client_t * action_client);
#ifdef __cplusplus
}
#endif
#endif // RCL_ACTION__ACTION_CLIENT_H_