Fix for hosting an in-game server (#719)

* Minimal fix for hosting an in-game server

* Further streamline server init data

Author: mibac138

Source/Client/Networking/HostUtil.cs

@@ -74,8 +74,8 @@ private static void PrepareLocalServer(ServerSettings settings, bool fromReplay)
                 localServer.startingTimer = TickPatch.Timer;
             }
 
-            localServer.initData =
-                ServerInitData.Deserialize(new ByteReader(ClientJoiningState.PackInitData(settings.syncConfigs)));
+            localServer.StartInitData().SetResult(
+                ServerInitData.Deserialize(new ByteReader(ClientJoiningState.PackInitData(settings.syncConfigs))));
         }
 
         private static void PrepareGame()

Source/Common/CommandHandler.cs

@@ -20,11 +20,11 @@ public void Send(CommandType cmd, int factionId, int mapId, byte[] data, ServerP
             {
                 bool debugCmd =
                     cmd == CommandType.DebugTools ||
-                    cmd == CommandType.Sync && server.initData!.DebugOnlySyncCmds.Contains(BitConverter.ToInt32(data, 0));
+                    cmd == CommandType.Sync && server.InitData!.DebugOnlySyncCmds.Contains(BitConverter.ToInt32(data, 0));
                 if (debugCmd && !CanUseDevMode(sourcePlayer))
                     return;
 
-                bool hostOnly = cmd == CommandType.Sync && server.initData!.HostOnlySyncCmds.Contains(BitConverter.ToInt32(data, 0));
+                bool hostOnly = cmd == CommandType.Sync && server.InitData!.HostOnlySyncCmds.Contains(BitConverter.ToInt32(data, 0));
                 if (hostOnly && !sourcePlayer.IsHost)
                     return;
 

Source/Common/MultiplayerServer.cs

@@ -47,10 +47,10 @@ static MultiplayerServer()
         public ActionQueue queue = new();
         public ServerSettings settings;
 
-        public ServerInitData? initData;
+        public ServerInitData? InitData => initDataSource.Task.ResultNowOrNull();
         private TaskCompletionSource<ServerInitData?> initDataSource = new();
         public InitDataState InitDataState =>
-            initData != null ? InitDataState.Complete :
+            InitData != null ? InitDataState.Complete :
             // started init data must've completed with null, meaning the client disconnected while waiting for the data,
             // so we are waiting again
             initDataSource.Task.IsCompleted ? InitDataState.Waiting :
@@ -250,22 +250,15 @@ public void RegisterChatCmd(string cmdName, ChatCmdHandler handler) =>
 
         public void HandleChatCmd(IChatSource source, string cmd) => chatCmdManager.Handle(source, cmd);
 
-        public Task<ServerInitData?> InitData() => initDataSource.Task;
+        public Task<ServerInitData?> InitDataTask() => initDataSource.Task;
 
         /// Can only start one init data at a time. A StartInitData is considered complete once
         /// TaskCompletionResult.SetResult is called. Until that time no new calls to StartInitData will succeed.
         public TaskCompletionSource<ServerInitData?> StartInitData()
         {
             if (InitDataState != InitDataState.Waiting)
                 throw new InvalidOperationException($"Can't start init data in state {InitDataState}");
-            var currInitDataSource = initDataSource = new TaskCompletionSource<ServerInitData?>();
-            currInitDataSource.Task.ContinueWith(task =>
-            {
-                if (currInitDataSource != initDataSource)
-                    ServerLog.Error("InitDataSource changed during StartInitData");
-                initData = task.Result;
-            }, TaskContinuationOptions.ExecuteSynchronously);
-            return currInitDataSource;
+            return initDataSource = new TaskCompletionSource<ServerInitData?>();
         }
     }
 

Source/Common/Networking/State/ServerJoiningState.cs

@@ -1,4 +1,5 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 
 namespace Multiplayer.Common;
 
@@ -13,7 +14,7 @@ protected override async Task RunState()
         HandleProtocol(await Packet(Packets.Client_Protocol));
         HandleUsername(await Packet(Packets.Client_Username));
 
-        while (await Server.InitData() is null && await EndIfDead())
+        while (await Server.InitDataTask() is null && await EndIfDead())
             if (Server.InitDataState == InitDataState.Waiting)
                 await RequestInitData();
 
@@ -105,9 +106,11 @@ private bool HandleClientJoinData(ByteReader data)
         var modCtorRoundMode = data.ReadEnum<RoundModeEnum>();
         var staticCtorRoundMode = data.ReadEnum<RoundModeEnum>();
 
-        if ((modCtorRoundMode, staticCtorRoundMode) != Server.initData!.RoundModes)
+        var serverInitData = Server.InitData ??
+                             throw new Exception("Server init data is null during handling of client join data");
+        if ((modCtorRoundMode, staticCtorRoundMode) != serverInitData.RoundModes)
         {
-            Player.Disconnect($"FP round modes don't match: {(modCtorRoundMode, staticCtorRoundMode)} != {Server.initData!.RoundModes}");
+            Player.Disconnect($"FP round modes don't match: {(modCtorRoundMode, staticCtorRoundMode)} != {serverInitData.RoundModes}");
             return false;
         }
 
@@ -129,7 +132,7 @@ private bool HandleClientJoinData(ByteReader data)
 
             var status = DefCheckStatus.Ok;
 
-            if (!Server.initData!.DefInfos.TryGetValue(defType, out DefInfo info))
+            if (!serverInitData.DefInfos.TryGetValue(defType, out DefInfo info))
                 status = DefCheckStatus.Not_Found;
             else if (info.count != defCount)
                 status = DefCheckStatus.Count_Diff;
@@ -146,10 +149,10 @@ private bool HandleClientJoinData(ByteReader data)
             Packets.Server_JoinData,
             Server.settings.gameName,
             Player.id,
-            Server.initData!.RwVersion,
+            serverInitData.RwVersion,
             MpVersion.Version,
             defsResponse.ToArray(),
-            Server.initData.RawData
+            serverInitData.RawData
         );
 
         return defsMatch;

Source/Common/Util/Extensions.cs

@@ -7,6 +7,7 @@
 using System.Reflection;
 using System.Security.Cryptography;
 using System.Text;
+using System.Threading.Tasks;
 
 namespace Multiplayer.Common
 {
@@ -128,6 +129,9 @@ public static float MaxOrZero<T>(this IEnumerable<T> items, Func<T, float> map)
         {
             return items.Max(i => (float?)map(i)) ?? 0f;
         }
+
+        public static T? ResultNowOrNull<T>(this Task<T> task) where T : class? =>
+            task.Status == TaskStatus.RanToCompletion ? task.Result : null;
     }
 
     public static class Utils