Publishing is slow in Docker with MutliThreadedExecutor

  ros2/rclcpp#1487

Signed-off-by: Tomoya.Fujita <Tomoya.Fujita@sony.com>

CMakeLists.txt

@@ -63,6 +63,7 @@ endfunction()
 custom_executable(rclcpp_1431)
 custom_executable(rclcpp_1454)
 custom_executable(rclcpp_1455)
+custom_executable(rclcpp_1487)
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" AND
     "${CMAKE_CXX_COMPILER_VERSION}" VERSION_LESS 6.0)

src/rclcpp_1487.cpp

@@ -0,0 +1,53 @@
+#include <chrono>
+#include <condition_variable>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <thread>
+
+#include "rclcpp/rclcpp.hpp"
+#include "std_msgs/msg/string.hpp"
+
+using namespace std::chrono_literals;
+
+/* This example creates a subclass of Node and uses std::bind() to register a
+* member function as a callback from the timer. */
+
+class MinimalPublisher : public rclcpp::Node
+{
+  public:
+    MinimalPublisher()
+    : Node("minimal_publisher"), count_(0)
+    {
+      publisher_ = this->create_publisher<std_msgs::msg::String>("topic", 10);
+      timer_ = this->create_wall_timer(
+        1ms, std::bind(&MinimalPublisher::timer_callback, this)); // 1kHz
+    }
+
+  private:
+    void timer_callback()
+    {
+      auto message = std_msgs::msg::String();
+      message.data = "Hello, world! " + std::to_string(count_++);
+      // RCLCPP_INFO(this->get_logger(), "Publishing: '%s'", message.data.c_str());
+      publisher_->publish(message);
+    }
+    rclcpp::TimerBase::SharedPtr timer_;
+    rclcpp::Publisher<std_msgs::msg::String>::SharedPtr publisher_;
+    size_t count_;
+  };
+
+  int main(int argc, char * argv[])
+  {
+    rclcpp::init(argc, argv);
+
+    rclcpp::executors::MultiThreadedExecutor exe;
+    // rclcpp::executors::SingleThreadedExecutor exe;
+
+    std::shared_ptr<MinimalPublisher> pub = std::make_shared<MinimalPublisher>();
+    exe.add_node(pub->get_node_base_interface());
+
+    exe.spin();
+    rclcpp::shutdown();
+    return 0;
+  }