construct TimerBase/GenericTimer with Clock

rclcpp/include/rclcpp/clock.hpp

@@ -99,6 +99,10 @@ class Clock
   bool
   ros_time_is_active();
 
+  RCLCPP_PUBLIC
+  rcl_clock_t *
+  get_clock_handle();
+
   RCLCPP_PUBLIC
   rcl_clock_type_t
   get_clock_type();

rclcpp/include/rclcpp/timer.hpp

@@ -23,6 +23,7 @@
 #include <type_traits>
 #include <utility>
 
+#include "rclcpp/clock.hpp"
 #include "rclcpp/function_traits.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/rate.hpp"
@@ -44,7 +45,7 @@ class TimerBase
   RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(TimerBase)
 
   RCLCPP_PUBLIC
-  explicit TimerBase(std::chrono::nanoseconds period);
+  explicit TimerBase(Clock::SharedPtr clock, std::chrono::nanoseconds period);
 
   RCLCPP_PUBLIC
   ~TimerBase();
@@ -85,6 +86,7 @@ class TimerBase
   bool is_ready();
 
 protected:
+  Clock::SharedPtr clock_;
   std::shared_ptr<rcl_timer_t> timer_handle_;
 };
 
@@ -95,11 +97,9 @@ using TimerCallbackType = std::function<void (TimerBase &)>;
 /// Generic timer templated on the clock type. Periodically executes a user-specified callback.
 template<
   typename FunctorT,
-  class Clock,
   typename std::enable_if<
-    (rclcpp::function_traits::same_arguments<FunctorT, VoidCallbackType>::value ||
-    rclcpp::function_traits::same_arguments<FunctorT, TimerCallbackType>::value) &&
-    Clock::is_steady
+    rclcpp::function_traits::same_arguments<FunctorT, VoidCallbackType>::value ||
+    rclcpp::function_traits::same_arguments<FunctorT, TimerCallbackType>::value
   >::type * = nullptr
 >
 class GenericTimer : public TimerBase
@@ -112,8 +112,10 @@ class GenericTimer : public TimerBase
    * \param[in] period The interval at which the timer fires.
    * \param[in] callback User-specified callback function.
    */
-  GenericTimer(std::chrono::nanoseconds period, FunctorT && callback)
-  : TimerBase(period), callback_(std::forward<FunctorT>(callback))
+  explicit GenericTimer(
+    Clock::SharedPtr clock, std::chrono::nanoseconds period, FunctorT && callback
+  )
+  : TimerBase(clock, period), callback_(std::forward<FunctorT>(callback))
   {
   }
 
@@ -165,7 +167,7 @@ class GenericTimer : public TimerBase
   virtual bool
   is_steady()
   {
-    return Clock::is_steady;
+    return clock_->get_clock_type() == RCL_STEADY_TIME;
   }
 
 protected:
@@ -174,8 +176,26 @@ class GenericTimer : public TimerBase
   FunctorT callback_;
 };
 
-template<typename CallbackType>
-using WallTimer = GenericTimer<CallbackType, std::chrono::steady_clock>;
+template<
+  typename FunctorT,
+  typename std::enable_if<
+    rclcpp::function_traits::same_arguments<FunctorT, VoidCallbackType>::value ||
+    rclcpp::function_traits::same_arguments<FunctorT, TimerCallbackType>::value
+  >::type * = nullptr
+>
+class WallTimer : public GenericTimer<FunctorT>
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(WallTimer)
+
+  explicit WallTimer(std::chrono::nanoseconds period, FunctorT && callback)
+  : GenericTimer<FunctorT>(
+      std::make_shared<Clock>(RCL_STEADY_TIME), period, std::move(callback))
+  {}
+
+protected:
+  RCLCPP_DISABLE_COPY(WallTimer)
+};
 
 }  // namespace rclcpp
 

rclcpp/src/rclcpp/clock.cpp

@@ -103,6 +103,12 @@ Clock::ros_time_is_active()
   return is_enabled;
 }
 
+rcl_clock_t *
+Clock::get_clock_handle()
+{
+  return &rcl_clock_;
+}
+
 rcl_clock_type_t
 Clock::get_clock_type()
 {

rclcpp/src/rclcpp/time_source.cpp

@@ -65,7 +65,7 @@ void TimeSource::attachNode(
   node_services_ = node_services_interface;
   // TODO(tfoote): Update QOS
 
-  const std::string & topic_name = "/clock";
+  const std::string topic_name = "/clock";
 
   rclcpp::callback_group::CallbackGroup::SharedPtr group;
   using rclcpp::message_memory_strategy::MessageMemoryStrategy;

rclcpp/src/rclcpp/timer.cpp

@@ -22,8 +22,10 @@
 
 using rclcpp::TimerBase;
 
-TimerBase::TimerBase(std::chrono::nanoseconds period)
+TimerBase::TimerBase(rclcpp::Clock::SharedPtr clock, std::chrono::nanoseconds period)
 {
+  clock_ = clock;
+
   timer_handle_ = std::shared_ptr<rcl_timer_t>(
     new rcl_timer_t, [ = ](rcl_timer_t * timer)
     {
@@ -38,8 +40,9 @@ TimerBase::TimerBase(std::chrono::nanoseconds period)
 
   *timer_handle_.get() = rcl_get_zero_initialized_timer();
 
+  rcl_clock_t * clock_handle = clock_->get_clock_handle();
   if (rcl_timer_init(
-      timer_handle_.get(), period.count(), nullptr,
+      timer_handle_.get(), clock_handle, period.count(), nullptr,
       rcl_get_default_allocator()) != RCL_RET_OK)
   {
     RCUTILS_LOG_ERROR_NAMED(