Update the documentation

Author: saikishor

controller_interface/include/controller_interface/controller_interface_base.hpp

@@ -202,8 +202,20 @@ class ControllerInterfaceBase : public rclcpp_lifecycle::node_interfaces::Lifecy
 
   std::shared_ptr<const rclcpp_lifecycle::LifecycleNode> get_node() const;
 
+  /**
+   * Get the current lifecycle state of the controller node.
+   * \note This method is not real-time safe and should not be called in the control loop.
+   * \note This method is thread safe.
+   * \returns lifecycle state of the controller node.
+   */
   const rclcpp_lifecycle::State & get_lifecycle_state() const;
 
+  /**
+   * Get the lifecycle id of the controller node that is cached internally
+   * to avoid calls to get_lifecycle_state() in the real-time control loop.
+   * \note This method is real-time safe and thread safe and can be called in the control loop.
+   * \returns lifecycle id of the controller node.
+   */
   uint8_t get_lifecycle_id() const;
 
   unsigned int get_update_rate() const;

hardware_interface/include/hardware_interface/hardware_component_interface.hpp

@@ -678,12 +678,17 @@ class HardwareComponentInterface : public rclcpp_lifecycle::node_interfaces::Lif
 
   /// Get life-cycle state of the hardware.
   /**
+   * \note This method is not real-time safe and should not be called in the control loop.
+   * \note This method is thread safe.
    * \return state.
    */
   const rclcpp_lifecycle::State & get_lifecycle_state() const { return lifecycle_state_; }
 
   /// Set life-cycle state of the hardware.
   /**
+   * Get the lifecycle id of the hardware component interface that is cached internally to avoid
+   * calls to get_lifecycle_state() in the real-time control loop.
+   * \note This method is real-time safe and thread safe and can be called in the control loop.
    * \return state.
    */
   void set_lifecycle_state(const rclcpp_lifecycle::State & new_state)