Refactor ServerEntityEventManager event processing

Introduces async event processing with cancellation support using SemaphoreSlim and CancellationTokenSource. Improves client event handling logic, separates in-game and mid-round sync clients, and adds proper disposal of resources. Enhances robustness and maintainability of event management.

Barotrauma/BarotraumaServer/ServerSource/Networking/NetEntityEvent/ServerEntityEventManager.cs

@@ -123,29 +123,35 @@ namespace Barotrauma.Networking
 
         private readonly Task createEventTask;
 
+        private readonly CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
+        private readonly SemaphoreSlim eventSignal = new SemaphoreSlim(0);
+
         public ServerEntityEventManager(GameServer server)
         {
             events = new List<ServerEntityEvent>();
-
             this.server = server;
-
             bufferedEvents = new List<BufferedEvent>();
-
             uniqueEvents = new List<ServerEntityEvent>();
-
             pendingCreateQueue = new ConcurrentQueue<PendingCreateEvent>();
-
             lastWarningTime = -10.0;
-
             SEM = this;
 
-            createEventTask = Task.Run(async () => await CreateEventProcessorLoop());
+            createEventTask = Task.Run(() => CreateEventProcessorLoop(cancellationTokenSource.Token));
         }
-        private Task CreateEventProcessorLoop()
+
+        private async Task CreateEventProcessorLoop(CancellationToken token)
         {
-            while (true)
+            while (!token.IsCancellationRequested)
             {
-                ProcessPendingCreateEvents();
+                try
+                {
+                    await eventSignal.WaitAsync(100, token);
+                    ProcessPendingCreateEvents();
+                }
+                catch (OperationCanceledException)
+                {
+                    break;
+                }
             }
         }
 
@@ -209,10 +215,31 @@ namespace Barotrauma.Networking
 
             // enqueue and let background task handle the rest
             pendingCreateQueue.Enqueue(new PendingCreateEvent(entity, extraData));
+            
+            if (eventSignal.CurrentCount == 0)
+            {
+                eventSignal.Release();
+            }
         }
+
+        public void Dispose()
+        {
+            cancellationTokenSource.Cancel();
+            eventSignal.Release();
+            try
+            {
+                createEventTask?.Wait(2000);
+            }
+            catch (AggregateException) { }
+            finally
+            {
+                cancellationTokenSource.Dispose();
+                eventSignal.Dispose();
+            }
+        }
+
         public void Update(List<Client> clients)
         {
-
             foreach (BufferedEvent bufferedEvent in bufferedEvents)
             {
                 if (bufferedEvent.Character == null || bufferedEvent.Character.IsDead)
@@ -258,25 +285,45 @@ namespace Barotrauma.Networking
                 bufferedEvent.IsProcessed = true;
             }
 
-            var inGameClients = clients.FindAll(c => c.InGame && !c.NeedsMidRoundSync);
+            List<Client> inGameClients = null;
-            if (inGameClients.Count > 0)
+            List<Client> midRoundSyncClients = null;
+            Client ownerClient = null;
+            
+            foreach (var c in clients)
             {
-                lastSentToAnyone = inGameClients[0].LastRecvEntityEventID;
+                if (c.InGame)
-                lastSentToAll = inGameClients[0].LastRecvEntityEventID;
-
-                if (server.OwnerConnection != null)
                 {
-                    var owner = clients.Find(c => c.Connection == server.OwnerConnection);
+                    if (c.NeedsMidRoundSync)
-                    if (owner != null)
                     {
-                        lastSentToAll = owner.LastRecvEntityEventID;
+                        (midRoundSyncClients ??= new List<Client>()).Add(c);
+                    }
+                    else
+                    {
+                        (inGameClients ??= new List<Client>()).Add(c);
                     }
                 }
-                inGameClients.ForEach(c =>
+                if (server.OwnerConnection != null && c.Connection == server.OwnerConnection)
                 {
-                    if (NetIdUtils.IdMoreRecent(lastSentToAll, c.LastRecvEntityEventID)) { lastSentToAll = c.LastRecvEntityEventID; }
+                    ownerClient = c;
-                    if (NetIdUtils.IdMoreRecent(c.LastRecvEntityEventID, lastSentToAnyone)) { lastSentToAnyone = c.LastRecvEntityEventID; }
+                }
-                });
+            }
+
+            if (inGameClients != null && inGameClients.Count > 0)
+            {
+                lastSentToAnyone = inGameClients[0].LastRecvEntityEventID;
+                lastSentToAll = ownerClient?.LastRecvEntityEventID ?? inGameClients[0].LastRecvEntityEventID;
+
+                foreach (var c in inGameClients)
+                {
+                    if (NetIdUtils.IdMoreRecent(lastSentToAll, c.LastRecvEntityEventID)) 
+                    { 
+                        lastSentToAll = c.LastRecvEntityEventID; 
+                    }
+                    if (NetIdUtils.IdMoreRecent(c.LastRecvEntityEventID, lastSentToAnyone)) 
+                    { 
+                        lastSentToAnyone = c.LastRecvEntityEventID; 
+                    }
+                }
                 lastSentToAnyoneTime = events.Find(e => e.ID == lastSentToAnyone)?.CreateTime ?? Timing.TotalTime;
 
                 if (Timing.TotalTime - lastWarningTime > 5.0 &&
@@ -332,11 +379,21 @@ namespace Barotrauma.Networking
                 }
             }
 
-            var timedOutClients = clients.FindAll(c => c.Connection != GameMain.Server.OwnerConnection && c.InGame && c.NeedsMidRoundSync && Timing.TotalTime > c.MidRoundSyncTimeOut);
+            if (midRoundSyncClients != null)
-            foreach (Client timedOutClient in timedOutClients)
             {
-                GameServer.Log("Disconnecting client " + GameServer.ClientLogName(timedOutClient) + ". Syncing the client with the server took too long.", ServerLog.MessageType.Error);
+                foreach (var c in midRoundSyncClients)
-                GameMain.Server.DisconnectClient(timedOutClient, PeerDisconnectPacket.WithReason(DisconnectReason.SyncTimeout));
+                {
+                    if (NetIdUtils.IdMoreRecent(lastSentToAll, c.FirstNewEventID))
+                    {
+                        lastSentToAll = (ushort)(c.FirstNewEventID - 1);
+                    }
+                    
+                    if (c.Connection != GameMain.Server.OwnerConnection && Timing.TotalTime > c.MidRoundSyncTimeOut)
+                    {
+                        GameServer.Log("Disconnecting client " + GameServer.ClientLogName(c) + ". Syncing took too long.", ServerLog.MessageType.Error);
+                        GameMain.Server.DisconnectClient(c, PeerDisconnectPacket.WithReason(DisconnectReason.SyncTimeout));
+                    }
+                }
             }
 
             bufferedEvents.RemoveAll(b => b.IsProcessed);