feat: optimize game server tick loop performance

Ragon.Relay/Sources/Relay.cs

@@ -15,6 +15,7 @@
  */
 
 using System;
+using System.Diagnostics;
 using System.IO;
 using System.Threading;
 using Newtonsoft.Json;
@@ -40,9 +41,9 @@ namespace Ragon.Relay
       var configuration = JsonConvert.DeserializeObject<RelayConfiguration>(data);
       var serverType = RagonServerConfiguration.GetServerType(configuration.ServerType);
 
-      INetworkServer networkServer = new ENetServer();
+      INetworkServer networkServer;
       IServerPlugin plugin = new RelayServerPlugin();
-      
+
       switch (serverType)
       {
         case ServerType.ENET:
@@ -51,6 +52,9 @@ namespace Ragon.Relay
         case ServerType.WEBSOCKET:
           networkServer = new WebSocketServer();
           break;
+        default:
+          networkServer = new ENetServer();
+          break;
       }
 
       var serverConfiguration = new RagonServerConfiguration()
@@ -67,13 +71,30 @@ namespace Ragon.Relay
         ServerTickRate = configuration.ServerTickRate,
         ServerAddress = configuration.ServerAddress,
       };
-      
+
       var relay = new RagonServer(networkServer, plugin, serverConfiguration);
       relay.Start();
+
+      var sw = Stopwatch.StartNew();
+      var tickRateMs = 1000.0 / configuration.ServerTickRate;
+      var nextTickMs = tickRateMs;
+
       while (relay.IsRunning)
       {
         relay.Tick();
-        Thread.Sleep(1);
+
+        var sleepTime = nextTickMs - sw.Elapsed.TotalMilliseconds;
+        if (sleepTime > 0)
+        {
+          Thread.Sleep((int)sleepTime);
+        }
+
+        nextTickMs += tickRateMs;
+
+        if (nextTickMs < sw.Elapsed.TotalMilliseconds)
+        {
+          nextTickMs = sw.Elapsed.TotalMilliseconds + tickRateMs;
+        }
       }
 
       relay.Dispose();

Ragon.Server/Sources/RagonServer.cs

@@ -42,9 +42,7 @@ public class RagonServer : IRagonServer, INetworkListener
   private readonly Dictionary<ushort, RagonContext> _contextsByConnection;
   private readonly Dictionary<string, RagonContext> _contextsByPlayerId;
   private readonly ProjectRegistry _projectRegistry;
-  private readonly Stopwatch _timer;
   private readonly RagonLobbyDispatcher _lobbySerializer;
-  private readonly long _tickRate = 0;
   private bool _isRunning = false;
 
   public bool IsRunning => _isRunning;
@@ -66,13 +64,12 @@ public class RagonServer : IRagonServer, INetworkListener
     _scheduler = new RagonScheduler();
     _reader = new RagonBuffer();
     _writer = new RagonBuffer();
-    _tickRate = 1000 / _configuration.ServerTickRate;
-    _timer = new Stopwatch();
-    
+
     var contextObserver = new RagonContextObserver(_contextsByPlayerId);
     _scheduler.Run(new RagonActionTimer(SendRoomList, 2.0f));
     _scheduler.Run(new RagonActionTimer(SendPlayerUserData, 0.1f));
     _scheduler.Run(new RagonActionTimer(SendRoomUserData, 0.1f));
+    _scheduler.Run(new RagonActionTimer(SendTimestamp, 1.0f / _configuration.ServerTickRate));
     
     _serverPlugin.OnAttached(this);
 
@@ -98,19 +95,8 @@ public class RagonServer : IRagonServer, INetworkListener
   }
   public void Tick()
   {
-    if (_timer.ElapsedMilliseconds > _tickRate * 2)
-    {
-      _logger.Warning($"Slow performance: {_timer.ElapsedMilliseconds}");
-    }
-
-    if (_timer.ElapsedMilliseconds > _tickRate)
-    {
-      _timer.Restart();
-      _scheduler.Update(_timer.ElapsedMilliseconds / 1000.0f);
-
-      SendTimestamp();
-    }
-
+    var deltaTime = 1.0f / _configuration.ServerTickRate;
+    _scheduler.Update(deltaTime);
     _server.Update();
   }
 
@@ -129,8 +115,6 @@ public class RagonServer : IRagonServer, INetworkListener
     _server.Listen(this, networkConfiguration);
     _serverPlugin.OnAttached(this);
 
-    _timer.Start();
-
     _isRunning = true;
   }