Added optional TimerInfo to timer callback (ros2#2343)

Signed-off-by: Alexis Tsogias <a.tsogias@cellumation.com>
Signed-off-by: Janosch Machowinski <J.Machowinski@cellumation.com>
Co-authored-by: Alexis Tsogias <a.tsogias@cellumation.com>
Co-authored-by: Janosch Machowinski <J.Machowinski@cellumation.com>

rclcpp/include/rclcpp/executor.hpp

@@ -465,7 +465,7 @@ class Executor
    */
   RCLCPP_PUBLIC
   static void
-  execute_timer(rclcpp::TimerBase::SharedPtr timer);
+  execute_timer(rclcpp::TimerBase::SharedPtr timer, const std::shared_ptr<void> & dataPtr);
 
   /// Run service server executable.
   /**

rclcpp/include/rclcpp/experimental/executors/events_executor/events_executor_event_types.hpp

@@ -15,6 +15,8 @@
 #ifndef RCLCPP__EXPERIMENTAL__EXECUTORS__EVENTS_EXECUTOR__EVENTS_EXECUTOR_EVENT_TYPES_HPP_
 #define RCLCPP__EXPERIMENTAL__EXECUTORS__EVENTS_EXECUTOR__EVENTS_EXECUTOR_EVENT_TYPES_HPP_
 
+#include <memory>
+
 namespace rclcpp
 {
 namespace experimental
@@ -34,6 +36,7 @@ enum ExecutorEventType
 struct ExecutorEvent
 {
   const void * entity_key;
+  std::shared_ptr<void> data;
   int waitable_data;
   ExecutorEventType type;
   size_t num_events;

rclcpp/include/rclcpp/experimental/timers_manager.hpp

@@ -86,7 +86,8 @@ class TimersManager
   RCLCPP_PUBLIC
   TimersManager(
     std::shared_ptr<rclcpp::Context> context,
-    std::function<void(const rclcpp::TimerBase *)> on_ready_callback = nullptr);
+    std::function<void(const rclcpp::TimerBase *,
+    const std::shared_ptr<void> &)> on_ready_callback = nullptr);
 
   /**
    * @brief Destruct the TimersManager object making sure to stop thread and release memory.
@@ -164,9 +165,10 @@ class TimersManager
    * the TimersManager on_ready_callback was passed during construction.
    *
    * @param timer_id the timer ID of the timer to execute
+   * @param data internal data of the timer
    */
   RCLCPP_PUBLIC
-  void execute_ready_timer(const rclcpp::TimerBase * timer_id);
+  void execute_ready_timer(const rclcpp::TimerBase * timer_id, const std::shared_ptr<void> & data);
 
   /**
    * @brief Get the amount of time before the next timer triggers.
@@ -527,7 +529,8 @@ class TimersManager
   void execute_ready_timers_unsafe();
 
   // Callback to be called when timer is ready
-  std::function<void(const rclcpp::TimerBase *)> on_ready_callback_ = nullptr;
+  std::function<void(const rclcpp::TimerBase *,
+    const std::shared_ptr<void> &)> on_ready_callback_ = nullptr;
 
   // Thread used to run the timers execution task
   std::thread timers_thread_;

rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp

@@ -368,7 +368,8 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
           ++it;
           continue;
         }
-        if (!timer->call()) {
+        auto data = timer->call();
+        if (!data) {
           // timer was cancelled, skip it.
           ++it;
           continue;
@@ -377,6 +378,7 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
         any_exec.timer = timer;
         any_exec.callback_group = group;
         any_exec.node_base = get_node_by_group(group, weak_groups_to_nodes);
+        any_exec.data = data;
         timer_handles_.erase(it);
         return;
       }

rclcpp/include/rclcpp/timer.hpp

@@ -18,6 +18,7 @@
 #include <atomic>
 #include <chrono>
 #include <functional>
+#include <optional>
 #include <memory>
 #include <sstream>
 #include <thread>
@@ -43,6 +44,12 @@
 namespace rclcpp
 {
 
+struct TimerInfo
+{
+  Time expected_call_time;
+  Time actual_call_time;
+};
+
 class TimerBase
 {
 public:
@@ -96,16 +103,20 @@ class TimerBase
    * The multithreaded executor takes advantage of this to avoid scheduling
    * the callback multiple times.
    *
-   * \return `true` if the callback should be executed, `false` if the timer was canceled.
+   * \return a valid shared_ptr if the callback should be executed,
+   *         an invalid shared_ptr (nullptr) if the timer was canceled.
    */
   RCLCPP_PUBLIC
-  virtual bool
+  virtual std::shared_ptr<void>
   call() = 0;
 
   /// Call the callback function when the timer signal is emitted.
+  /**
+   * \param[in] data the pointer returned by the call function
+   */
   RCLCPP_PUBLIC
   virtual void
-  execute_callback() = 0;
+  execute_callback(const std::shared_ptr<void> & data) = 0;
 
   RCLCPP_PUBLIC
   std::shared_ptr<const rcl_timer_t>
@@ -193,16 +204,17 @@ class TimerBase
   set_on_reset_callback(rcl_event_callback_t callback, const void * user_data);
 };
 
-
 using VoidCallbackType = std::function<void ()>;
 using TimerCallbackType = std::function<void (TimerBase &)>;
+using TimerInfoCallbackType = std::function<void (const TimerInfo &)>;
 
 /// Generic timer. Periodically executes a user-specified callback.
 template<
   typename FunctorT,
   typename std::enable_if<
     rclcpp::function_traits::same_arguments<FunctorT, VoidCallbackType>::value ||
-    rclcpp::function_traits::same_arguments<FunctorT, TimerCallbackType>::value
+    rclcpp::function_traits::same_arguments<FunctorT, TimerCallbackType>::value ||
+    rclcpp::function_traits::same_arguments<FunctorT, TimerInfoCallbackType>::value
   >::type * = nullptr
 >
 class GenericTimer : public TimerBase
@@ -250,27 +262,28 @@ class GenericTimer : public TimerBase
    * \sa rclcpp::TimerBase::call
    * \throws std::runtime_error if it failed to notify timer that callback will occurr
    */
-  bool
+  std::shared_ptr<void>
   call() override
   {
-    rcl_ret_t ret = rcl_timer_call(timer_handle_.get());
+    auto timer_call_info_ = std::make_shared<rcl_timer_call_info_t>();
+    rcl_ret_t ret = rcl_timer_call_with_info(timer_handle_.get(), timer_call_info_.get());
     if (ret == RCL_RET_TIMER_CANCELED) {
-      return false;
+      return nullptr;
     }
     if (ret != RCL_RET_OK) {
       throw std::runtime_error("Failed to notify timer that callback occurred");
     }
-    return true;
+    return timer_call_info_;
   }
 
   /**
    * \sa rclcpp::TimerBase::execute_callback
    */
   void
-  execute_callback() override
+  execute_callback(const std::shared_ptr<void> & data) override
   {
     TRACEPOINT(callback_start, reinterpret_cast<const void *>(&callback_), false);
-    execute_callback_delegate<>();
+    execute_callback_delegate<>(*static_cast<rcl_timer_call_info_t *>(data.get()));
     TRACEPOINT(callback_end, reinterpret_cast<const void *>(&callback_));
   }
 
@@ -282,7 +295,7 @@ class GenericTimer : public TimerBase
     >::type * = nullptr
   >
   void
-  execute_callback_delegate()
+  execute_callback_delegate(const rcl_timer_call_info_t &)
   {
     callback_();
   }
@@ -294,11 +307,26 @@ class GenericTimer : public TimerBase
     >::type * = nullptr
   >
   void
-  execute_callback_delegate()
+  execute_callback_delegate(const rcl_timer_call_info_t &)
   {
     callback_(*this);
   }
 
+
+  template<
+    typename CallbackT = FunctorT,
+    typename std::enable_if<
+      rclcpp::function_traits::same_arguments<CallbackT, TimerInfoCallbackType>::value
+    >::type * = nullptr
+  >
+  void
+  execute_callback_delegate(const rcl_timer_call_info_t & timer_call_info_)
+  {
+    const TimerInfo info{Time{timer_call_info_.expected_call_time, clock_->get_clock_type()},
+      Time{timer_call_info_.actual_call_time, clock_->get_clock_type()}};
+    callback_(info);
+  }
+
   /// Is the clock steady (i.e. is the time between ticks constant?)
   /** \return True if the clock used by this timer is steady. */
   bool
@@ -317,7 +345,8 @@ template<
   typename FunctorT,
   typename std::enable_if<
     rclcpp::function_traits::same_arguments<FunctorT, VoidCallbackType>::value ||
-    rclcpp::function_traits::same_arguments<FunctorT, TimerCallbackType>::value
+    rclcpp::function_traits::same_arguments<FunctorT, TimerCallbackType>::value ||
+    rclcpp::function_traits::same_arguments<FunctorT, TimerInfoCallbackType>::value
   >::type * = nullptr
 >
 class WallTimer : public GenericTimer<FunctorT>

rclcpp/src/rclcpp/executor.cpp

@@ -367,7 +367,7 @@ Executor::execute_any_executable(AnyExecutable & any_exec)
     TRACEPOINT(
       rclcpp_executor_execute,
       static_cast<const void *>(any_exec.timer->get_timer_handle().get()));
-    execute_timer(any_exec.timer);
+    execute_timer(any_exec.timer, any_exec.data);
   }
   if (any_exec.subscription) {
     TRACEPOINT(
@@ -530,9 +530,9 @@ Executor::execute_subscription(rclcpp::SubscriptionBase::SharedPtr subscription)
 }
 
 void
-Executor::execute_timer(rclcpp::TimerBase::SharedPtr timer)
+Executor::execute_timer(rclcpp::TimerBase::SharedPtr timer, const std::shared_ptr<void> & dataPtr)
 {
-  timer->execute_callback();
+  timer->execute_callback(dataPtr);
 }
 
 void
@@ -673,6 +673,7 @@ Executor::get_next_ready_executable(AnyExecutable & any_executable)
       if (entity_iter != current_collection_.timers.end()) {
         auto callback_group = entity_iter->second.callback_group.lock();
         if (callback_group && !callback_group->can_be_taken_from()) {
+          current_timer_index++;
           continue;
         }
         // At this point the timer is either ready for execution or was perhaps
@@ -681,14 +682,17 @@ Executor::get_next_ready_executable(AnyExecutable & any_executable)
         // it from the wait result.
         wait_result_->clear_timer_with_index(current_timer_index);
         // Check that the timer should be called still, i.e. it wasn't canceled.
-        if (!timer->call()) {
+        any_executable.data = timer->call();
+        if (!any_executable.data) {
+          current_timer_index++;
           continue;
         }
         any_executable.timer = timer;
         any_executable.callback_group = callback_group;
         valid_executable = true;
         break;
       }
+      current_timer_index++;
     }
   }
 

rclcpp/src/rclcpp/executors/static_single_threaded_executor.cpp

@@ -154,11 +154,15 @@ bool StaticSingleThreadedExecutor::execute_ready_executables(
     auto entity_iter = collection.timers.find(timer->get_timer_handle().get());
     if (entity_iter != collection.timers.end()) {
       wait_result.clear_timer_with_index(current_timer_index);
-      if (timer->call()) {
-        execute_timer(timer);
-        any_ready_executable = true;
-        if (spin_once) {return any_ready_executable;}
+      auto data = timer->call();
+      if (!data) {
+        // someone canceled the timer between is_ready and call
+        continue;
       }
+
+      execute_timer(std::move(timer), data);
+      any_ready_executable = true;
+      if (spin_once) {return any_ready_executable;}
     }
   }
 

rclcpp/src/rclcpp/experimental/executors/events_executor/events_executor.cpp

@@ -40,10 +40,12 @@ EventsExecutor::EventsExecutor(
   // The timers manager can be used either to only track timers (in this case an expired
   // timer will generate an executor event and then it will be executed by the executor thread)
   // or it can also take care of executing expired timers in its dedicated thread.
-  std::function<void(const rclcpp::TimerBase *)> timer_on_ready_cb = nullptr;
+  std::function<void(const rclcpp::TimerBase *,
+    const std::shared_ptr<void> &)> timer_on_ready_cb = nullptr;
   if (!execute_timers_separate_thread) {
-    timer_on_ready_cb = [this](const rclcpp::TimerBase * timer_id) {
-        ExecutorEvent event = {timer_id, -1, ExecutorEventType::TIMER_EVENT, 1};
+    timer_on_ready_cb =
+      [this](const rclcpp::TimerBase * timer_id, const std::shared_ptr<void> & data) {
+        ExecutorEvent event = {timer_id, data, -1, ExecutorEventType::TIMER_EVENT, 1};
         this->events_queue_->enqueue(event);
       };
   }
@@ -88,7 +90,7 @@ EventsExecutor::EventsExecutor(
       }
 
       ExecutorEvent event =
-      {notify_waitable_entity_id, waitable_data, ExecutorEventType::WAITABLE_EVENT, 1};
+      {notify_waitable_entity_id, nullptr, waitable_data, ExecutorEventType::WAITABLE_EVENT, 1};
       this->events_queue_->enqueue(event);
     });
 
@@ -314,7 +316,7 @@ EventsExecutor::execute_event(const ExecutorEvent & event)
     case ExecutorEventType::TIMER_EVENT:
       {
         timers_manager_->execute_ready_timer(
-          static_cast<const rclcpp::TimerBase *>(event.entity_key));
+          static_cast<const rclcpp::TimerBase *>(event.entity_key), event.data);
         break;
       }
     case ExecutorEventType::WAITABLE_EVENT:
@@ -463,7 +465,7 @@ EventsExecutor::create_entity_callback(
 {
   std::function<void(size_t)>
   callback = [this, entity_key, event_type](size_t num_events) {
-      ExecutorEvent event = {entity_key, -1, event_type, num_events};
+      ExecutorEvent event = {entity_key, nullptr, -1, event_type, num_events};
       this->events_queue_->enqueue(event);
     };
   return callback;
@@ -475,7 +477,7 @@ EventsExecutor::create_waitable_callback(const rclcpp::Waitable * entity_key)
   std::function<void(size_t, int)>
   callback = [this, entity_key](size_t num_events, int waitable_data) {
       ExecutorEvent event =
-      {entity_key, waitable_data, ExecutorEventType::WAITABLE_EVENT, num_events};
+      {entity_key, nullptr, waitable_data, ExecutorEventType::WAITABLE_EVENT, num_events};
       this->events_queue_->enqueue(event);
     };
   return callback;