use SteadyTimer (if available) for cleaning up inactive streams (#63)

* use SteadyTimer for cleaning up inactive streams

so that cleanup works correctly even if system time changes

SteadyTimer is available since roscpp 1.13.1

* possibility to use SteadyTimer on older ROS versions

when SteadyTimer has been backported to those...

Author: flixr

include/web_video_server/web_video_server.h

@@ -51,7 +51,11 @@ class WebVideoServer
   void cleanup_inactive_streams();
 
   ros::NodeHandle nh_;
+#if ROS_VERSION_MINIMUM(1, 13, 1) || defined USE_STEADY_TIMER
+  ros::SteadyTimer cleanup_timer_;
+#else
   ros::Timer cleanup_timer_;
+#endif
   int ros_threads_;
   int port_;
   std::string address_;

src/web_video_server.cpp

@@ -44,7 +44,11 @@ WebVideoServer::WebVideoServer(ros::NodeHandle &nh, ros::NodeHandle &private_nh)
     nh_(nh), handler_group_(
         async_web_server_cpp::HttpReply::stock_reply(async_web_server_cpp::HttpReply::not_found))
 {
+#if ROS_VERSION_MINIMUM(1, 13, 1) || defined USE_STEADY_TIMER
+  cleanup_timer_ = nh.createSteadyTimer(ros::WallDuration(0.5), boost::bind(&WebVideoServer::cleanup_inactive_streams, this));
+#else
   cleanup_timer_ = nh.createTimer(ros::Duration(0.5), boost::bind(&WebVideoServer::cleanup_inactive_streams, this));
+#endif
 
   private_nh.param("port", port_, 8080);
   private_nh.param("verbose", __verbose, true);