Clock publisher works in dedeciated thread

Assets/AWSIM/Scenes/Main/AutowareSimulation.unity

@@ -38,7 +38,7 @@ RenderSettings:
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   m_Sun: {fileID: 0}
-  m_IndirectSpecularColor: {r: 1537.125, g: 1904.5333, b: 2520.709, a: 1}
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 --- !u!157 &3
 LightmapSettings:
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   m_LocalPosition: {x: 0, y: 0, z: 0}
   m_LocalScale: {x: 1, y: 1, z: 1}
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@@ -3621,6 +3622,72 @@ MonoBehaviour:
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   timeScaleSlider: {fileID: 1153401690}
   versionText: {fileID: 988705868}
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+      propertyPath: m_Name
+      value: TimeSourceSelector
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Assets/AWSIM/Scripts/Clock/Scripts/DotNetSystemTimeSource.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Threading;
+using ROS2;
+
+namespace AWSIM
+{
+    /// <summary>
+    /// A thread-safe timesource class that provides the dot net system utc time.
+    /// </summary>
+    public class DotNetSystemTimeSource : ITimeSource
+    {
+        private DateTime prevDateTime;
+        private double time;
+
+        private readonly object lockObject = new object();
+
+        public DotNetSystemTimeSource()
+        {
+            prevDateTime = DateTime.UtcNow;
+            time = 0.0;
+        }
+
+        public void GetTime(out int seconds, out uint nanoseconds)
+        {
+            lock (lockObject)
+            {
+                DateTime currDateTime = DateTime.UtcNow;
+                TimeSpan timeSpan = currDateTime - prevDateTime;
+                prevDateTime = currDateTime;
+
+                time += timeSpan.TotalMilliseconds * 0.001f * TimeScaleProvider.TimeScale;
+                TimeUtils.TimeFromTotalSeconds(time, out seconds, out nanoseconds);
+            }
+        }
+    }
+
+}

Assets/AWSIM/Scripts/Clock/Scripts/TimeScaleProvider.cs

@@ -0,0 +1,44 @@
+using UnityEngine;
+
+namespace AWSIM
+{
+    /// <summary>
+    /// A thread-safe static class to provide the value of the time scale of the simulation.
+    /// </summary>
+    public static class TimeScaleProvider
+    {
+        private static readonly object lockObject = new object();
+
+        private static float timeScale = 1.0f;
+        public static float TimeScale
+        {
+            get
+            {
+                lock (lockObject)
+                {
+                    return timeScale;
+                }
+            }
+        }
+
+
+        #region [Public Methods]
+
+        /// <summary>
+        /// Synchronise the value of the timeScale variable with the Time.timeScale from the Unity thread.
+        /// </summary>
+        public static void DoUpdate()
+        {
+            lock(lockObject)
+            {
+                if (Mathf.Abs(Time.timeScale - timeScale) > 0.01f)
+                {
+                    timeScale = Time.timeScale;
+                }
+            }
+        }
+
+        #endregion
+    }
+}
+

Assets/AWSIM/Scripts/Clock/Scripts/TimeSourceProvider.cs

@@ -11,7 +11,8 @@ public static class TimeSourceProvider
         public enum TimeSourceType
         {
             UNITY,
-            SS2
+            SS2,
+            DOTNET
         }
 
         #region [Event]
@@ -94,6 +95,18 @@ public static void SetTimeSource(TimeSourceType type)
                 return;
             }
 
+            // dot net system time source
+            if(type == TimeSourceType.DOTNET)
+            {
+                if(currentTimeSource == null || !(currentTimeSource is DotNetSystemTimeSource))
+                {
+                    currentTimeSource = new DotNetSystemTimeSource();
+                    onTimeSourceChanged?.Invoke();
+                }
+
+                return;
+            }
+
             // default time source
             if(currentTimeSource == null || !(currentTimeSource is UnityTimeSource))
             {

Assets/AWSIM/Scripts/ROS/ClockPublisher.cs

@@ -1,7 +1,6 @@
-using System.Collections;
-using System.Collections.Generic;
 using UnityEngine;
 using ROS2;
+using System.Threading;
 
 namespace AWSIM
 {
@@ -16,7 +15,9 @@ public class ClockPublisher : MonoBehaviour
 
         IPublisher<rosgraph_msgs.msg.Clock> clockPublisher;
         rosgraph_msgs.msg.Clock clockMsg;
-        float timeScale = 1.0f;
+
+        Thread clockThread;
+        bool isRunning = false;
 
 
         #region [Life Cycle]
@@ -28,38 +29,56 @@ void Awake()
             clockMsg = new rosgraph_msgs.msg.Clock();
         }
 
+        void Start()
+        {
+            TimeScaleProvider.DoUpdate();
+            StartClockThread();
+        }
+
         void OnDestroy()
         {
+            StopClockThread();
             SimulatorROS2Node.RemovePublisher<rosgraph_msgs.msg.Clock>(clockPublisher);
         }
 
         #endregion
 
-        void Start()
+        #region [Clock Thread]
+
+        void StartClockThread()
         {
-            timeScale = Time.timeScale;
-            InvokeRepeating("PublishClock", 1.0f, timeScale/publishHz);
+            clockThread = new Thread(UpdateClock)
+            {
+                Name = "Clock"
+            };
+            isRunning = true;
+            clockThread.Start();
         }
 
-        void Update() 
+        void StopClockThread()
         {
-            if (Mathf.Abs(Time.timeScale - timeScale) > 0.01f)
+            isRunning = false;
+            if (clockThread != null && clockThread.IsAlive)
             {
-                timeScale = Time.timeScale;
-                OnTimeScaleChanged();
+                clockThread.Join();
             }
         }
 
-        void OnTimeScaleChanged()
+        void UpdateClock()
         {
-            CancelInvoke();
-            InvokeRepeating("PublishClock", 0.0f, timeScale/publishHz);
+            while(isRunning)
+            {
+                Thread.Sleep(1000 / publishHz);
+                PublishClock();
+            }
         }
 
         void PublishClock()
         {
             SimulatorROS2Node.UpdateROSClockTime(clockMsg.Clock_);
             clockPublisher.Publish(clockMsg);
         }
+
+        #endregion
     }
 }

Assets/AWSIM/Scripts/UI/DemoUI.cs

@@ -24,6 +24,9 @@ public void SetTimeScale(float timeScale)
         {
             Time.timeScale = timeScale;
             timeScaleText.text = "x " + timeScale.ToString("F2");
+
+            // synchronisation of new timescale value with TimeScaleProvider
+            TimeScaleProvider.DoUpdate();
         }
     }
-}
+}