update rclcpp::Waitable API to use references and const (#2467)

Signed-off-by: William Woodall <[email protected]>

Author: wjwwood

rclcpp/include/rclcpp/event_handler.hpp

@@ -117,12 +117,12 @@ class EventHandlerBase : public Waitable
   /// Add the Waitable to a wait set.
   RCLCPP_PUBLIC
   void
-  add_to_wait_set(rcl_wait_set_t * wait_set) override;
+  add_to_wait_set(rcl_wait_set_t & wait_set) override;
 
   /// Check if the Waitable is ready.
   RCLCPP_PUBLIC
   bool
-  is_ready(rcl_wait_set_t * wait_set) override;
+  is_ready(const rcl_wait_set_t & wait_set) override;
 
   /// Set a callback to be called when each new event instance occurs.
   /**
@@ -294,7 +294,7 @@ class EventHandler : public EventHandlerBase
 
   /// Execute any entities of the Waitable that are ready.
   void
-  execute(std::shared_ptr<void> & data) override
+  execute(const std::shared_ptr<void> & data) override
   {
     if (!data) {
       throw std::runtime_error("'data' is empty");

rclcpp/include/rclcpp/executors/executor_notify_waitable.hpp

@@ -60,7 +60,7 @@ class ExecutorNotifyWaitable : public rclcpp::Waitable
    */
   RCLCPP_PUBLIC
   void
-  add_to_wait_set(rcl_wait_set_t * wait_set) override;
+  add_to_wait_set(rcl_wait_set_t & wait_set) override;
 
   /// Check conditions against the wait set
   /**
@@ -69,7 +69,7 @@ class ExecutorNotifyWaitable : public rclcpp::Waitable
    */
   RCLCPP_PUBLIC
   bool
-  is_ready(rcl_wait_set_t * wait_set) override;
+  is_ready(const rcl_wait_set_t & wait_set) override;
 
   /// Perform work associated with the waitable.
   /**
@@ -78,7 +78,7 @@ class ExecutorNotifyWaitable : public rclcpp::Waitable
    */
   RCLCPP_PUBLIC
   void
-  execute(std::shared_ptr<void> & data) override;
+  execute(const std::shared_ptr<void> & data) override;
 
   /// Retrieve data to be used in the next execute call.
   /**

rclcpp/include/rclcpp/experimental/subscription_intra_process.hpp

@@ -132,23 +132,22 @@ class SubscriptionIntraProcess
     );
   }
 
-  void execute(std::shared_ptr<void> & data) override
+  void execute(const std::shared_ptr<void> & data) override
   {
     execute_impl<SubscribedType>(data);
   }
 
 protected:
   template<typename T>
   typename std::enable_if<std::is_same<T, rcl_serialized_message_t>::value, void>::type
-  execute_impl(std::shared_ptr<void> & data)
+  execute_impl(const std::shared_ptr<void> &)
   {
-    (void)data;
     throw std::runtime_error("Subscription intra-process can't handle serialized messages");
   }
 
   template<class T>
   typename std::enable_if<!std::is_same<T, rcl_serialized_message_t>::value, void>::type
-  execute_impl(std::shared_ptr<void> & data)
+  execute_impl(const std::shared_ptr<void> & data)
   {
     if (!data) {
       return;

rclcpp/include/rclcpp/experimental/subscription_intra_process_base.hpp

@@ -60,7 +60,7 @@ class SubscriptionIntraProcessBase : public rclcpp::Waitable
 
   RCLCPP_PUBLIC
   void
-  add_to_wait_set(rcl_wait_set_t * wait_set) override;
+  add_to_wait_set(rcl_wait_set_t & wait_set) override;
 
   RCLCPP_PUBLIC
   virtual
@@ -72,7 +72,7 @@ class SubscriptionIntraProcessBase : public rclcpp::Waitable
   is_durability_transient_local() const;
 
   bool
-  is_ready(rcl_wait_set_t * wait_set) override = 0;
+  is_ready(const rcl_wait_set_t & wait_set) override = 0;
 
   std::shared_ptr<void>
   take_data() override = 0;
@@ -85,7 +85,7 @@ class SubscriptionIntraProcessBase : public rclcpp::Waitable
   }
 
   void
-  execute(std::shared_ptr<void> & data) override = 0;
+  execute(const std::shared_ptr<void> & data) override = 0;
 
   virtual
   bool

rclcpp/include/rclcpp/experimental/subscription_intra_process_buffer.hpp

@@ -101,16 +101,16 @@ class SubscriptionIntraProcessBuffer : public SubscriptionROSMsgIntraProcessBuff
   }
 
   void
-  add_to_wait_set(rcl_wait_set_t * wait_set) override
+  add_to_wait_set(rcl_wait_set_t & wait_set) override
   {
     if (this->buffer_->has_data()) {
       this->trigger_guard_condition();
     }
-    detail::add_guard_condition_to_rcl_wait_set(*wait_set, this->gc_);
+    detail::add_guard_condition_to_rcl_wait_set(wait_set, this->gc_);
   }
 
   bool
-  is_ready(rcl_wait_set_t * wait_set) override
+  is_ready(const rcl_wait_set_t & wait_set) override
   {
     (void) wait_set;
     return buffer_->has_data();

rclcpp/include/rclcpp/guard_condition.hpp

@@ -100,7 +100,7 @@ class GuardCondition
    */
   RCLCPP_PUBLIC
   void
-  add_to_wait_set(rcl_wait_set_t * wait_set);
+  add_to_wait_set(rcl_wait_set_t & wait_set);
 
   /// Set a callback to be called whenever the guard condition is triggered.
   /**
@@ -128,7 +128,9 @@ class GuardCondition
   std::recursive_mutex reentrant_mutex_;
   std::function<void(size_t)> on_trigger_callback_{nullptr};
   size_t unread_count_{0};
-  rcl_wait_set_t * wait_set_{nullptr};
+  // the type of wait_set_ is actually rcl_wait_set_t *, but it's never
+  // dereferenced, only compared to, so make it void * to avoid accidental use
+  void * wait_set_{nullptr};
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp

@@ -121,7 +121,7 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
       }
     }
     for (size_t i = 0; i < waitable_handles_.size(); ++i) {
-      if (waitable_handles_[i]->is_ready(wait_set)) {
+      if (waitable_handles_[i]->is_ready(*wait_set)) {
         waitable_triggered_handles_.emplace_back(std::move(waitable_handles_[i]));
       }
     }
@@ -235,7 +235,7 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
     }
 
     for (const std::shared_ptr<Waitable> & waitable : waitable_handles_) {
-      waitable->add_to_wait_set(wait_set);
+      waitable->add_to_wait_set(*wait_set);
     }
     return true;
   }

rclcpp/include/rclcpp/wait_result.hpp

@@ -277,7 +277,7 @@ class WaitResult final
       auto rcl_wait_set = wait_set.get_rcl_wait_set();
       while (next_waitable_index_ < wait_set.size_of_waitables()) {
         auto cur_waitable = wait_set.waitables(next_waitable_index_++);
-        if (cur_waitable != nullptr && cur_waitable->is_ready(&rcl_wait_set)) {
+        if (cur_waitable != nullptr && cur_waitable->is_ready(rcl_wait_set)) {
           waitable = cur_waitable;
           break;
         }

rclcpp/include/rclcpp/wait_set_policies/detail/storage_policy_common.hpp

@@ -375,7 +375,7 @@ class StoragePolicyCommon
         needs_pruning_ = true;
         continue;
       }
-      waitable_entry.waitable->add_to_wait_set(&rcl_wait_set_);
+      waitable_entry.waitable->add_to_wait_set(rcl_wait_set_);
     }
   }
 

rclcpp/include/rclcpp/waitable.hpp

@@ -101,6 +101,23 @@ class Waitable
   size_t
   get_number_of_ready_guard_conditions();
 
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Woverloaded-virtual"
+#endif
+  /// Deprecated.
+  /**
+   * \sa add_to_wait_set(rcl_wait_set_t &)
+   */
+  [[deprecated("Use add_to_wait_set(rcl_wait_set_t & wait_set) signature")]]
+  RCLCPP_PUBLIC
+  virtual
+  void
+  add_to_wait_set(rcl_wait_set_t * wait_set);
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
   /// Add the Waitable to a wait set.
   /**
    * \param[in] wait_set A handle to the wait set to add the Waitable to.
@@ -109,7 +126,24 @@ class Waitable
   RCLCPP_PUBLIC
   virtual
   void
-  add_to_wait_set(rcl_wait_set_t * wait_set) = 0;
+  add_to_wait_set(rcl_wait_set_t & wait_set);
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Woverloaded-virtual"
+#endif
+  /// Deprecated.
+  /**
+   * \sa is_ready(const rcl_wait_set_t &)
+   */
+  [[deprecated("Use is_ready(const rcl_wait_set_t & wait_set) signature")]]
+  RCLCPP_PUBLIC
+  virtual
+  bool
+  is_ready(rcl_wait_set_t * wait_set);
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
 
   /// Check if the Waitable is ready.
   /**
@@ -124,7 +158,7 @@ class Waitable
   RCLCPP_PUBLIC
   virtual
   bool
-  is_ready(rcl_wait_set_t * wait_set) = 0;
+  is_ready(const rcl_wait_set_t & wait_set);
 
   /// Take the data so that it can be consumed with `execute`.
   /**
@@ -178,6 +212,23 @@ class Waitable
   std::shared_ptr<void>
   take_data_by_entity_id(size_t id);
 
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Woverloaded-virtual"
+#endif
+  /// Deprecated.
+  /**
+   * \sa execute(const std::shared_ptr<void> &)
+   */
+  [[deprecated("Use execute(const std::shared_ptr<void> & data) signature")]]
+  RCLCPP_PUBLIC
+  virtual
+  void
+  execute(std::shared_ptr<void> & data);
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
   /// Execute data that is passed in.
   /**
    * Before calling this method, the Waitable should be added to a wait set,
@@ -203,7 +254,7 @@ class Waitable
   RCLCPP_PUBLIC
   virtual
   void
-  execute(std::shared_ptr<void> & data) = 0;
+  execute(const std::shared_ptr<void> & data);
 
   /// Exchange the "in use by wait set" state for this timer.
   /**