Fix rcl_action documentation (#380)

* Fix rcl_action_goal_info_t documentation

* Fix rcl_action_expire_goals documentation

* Fix information about thread safety

Signed-off-by: Jacob Perron <jacob@openrobotics.org>

rcl_action/include/rcl_action/action_server.h

@@ -354,11 +354,11 @@ rcl_action_send_goal_response(
  * rcl_ret_t ret = rcl_action_take_goal_request(&action_server, &goal_request);
  * // ... error handling
  * // If the goal is accepted, then tell the action server
- * // First, create and populate a goal info message (rcl type)
+ * // First, create a goal info message
  * rcl_action_goal_info_t goal_info = rcl_action_get_zero_initialized_goal_info();
- * ret = rcl_action_goal_info_init(&goal_info, &action_server);
+ * // ... populate goal_info.uuid (unique_identifier_msgs/UUID)
- * // ... error handling, and populate with goal ID and timestamp
+ * // ... populate goal_info.stamp (builtin_interfaces/Time)
- * ret = rcl_action_accept_new_goal(&action_server, &goal_info, NULL);
+ * rcl_action_goal_handle_t * goal_handle = rcl_action_accept_new_goal(&action_server, &goal_info);
  * // ... error_handling
  * // ... Populate goal response (client library type)
  * ret = rcl_action_send_goal_response(&action_server, &goal_response);
@@ -370,7 +370,7 @@ rcl_action_send_goal_response(
  * Attribute          | Adherence
  * ------------------ | -------------
  * Allocates Memory   | Yes
- * Thread-Safe        | Yes
+ * Thread-Safe        | No
  * Uses Atomics       | No
  * Lock-Free          | Yes
  *
@@ -602,7 +602,6 @@ rcl_action_send_result_response(
  *
  * \param[in] action_server handle to the action server from which expired goals
  *   will be cleared.
- * \param[in] expired_goals_allocator allocator to use to allocate expired_goals output
  * \param[inout] expired_goals the identifiers of goals that expired, or set to `NULL` if unused
  * \param[inout] expired_goals_capacity the allocated size of `expired_goals`, or 0 if unused
  * \param[out] num_expired the number of expired goals, or set to `NULL` if unused

rcl_action/include/rcl_action/types.h

@@ -104,11 +104,7 @@ typedef enum rcl_action_goal_event_t
   GOAL_EVENT_NUM_EVENTS
 } rcl_action_goal_event_t;
 
-/// Return a rcl_action_goal_info_t with members set to `NULL`.
+/// Return a rcl_action_goal_info_t with members set to zero values.
-/**
- * Should be called to get a null rcl_action_goal_info_t before passing to
- * rcl_action_goal_info_init().
- */
 RCL_ACTION_PUBLIC
 RCL_WARN_UNUSED
 rcl_action_goal_info_t

rcl_action/include/rcl_action/wait.h

@@ -122,7 +122,7 @@ rcl_action_wait_set_add_action_server(
  * Attribute          | Adherence
  * ------------------ | -------------
  * Allocates Memory   | No
- * Thread-Safe        | No
+ * Thread-Safe        | Yes
  * Uses Atomics       | No
  * Lock-Free          | Yes
  *
@@ -162,7 +162,7 @@ rcl_action_client_wait_set_get_num_entities(
  * Attribute          | Adherence
  * ------------------ | -------------
  * Allocates Memory   | No
- * Thread-Safe        | No
+ * Thread-Safe        | Yes
  * Uses Atomics       | No
  * Lock-Free          | Yes
  *