fix intermittent issue with game interface during connection loss with servers

Application/Application.csproj

@@ -24,7 +24,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Jint" Version="3.0.0-beta-2037" />
+    <PackageReference Include="Jint" Version="3.0.0-beta-2038" />
     <PackageReference Include="MaxMind.GeoIP2" Version="5.1.0" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="6.0.1">
       <PrivateAssets>all</PrivateAssets>

Application/IW4MServer.cs

@@ -792,8 +792,16 @@ namespace IW4MAdmin
         /// <returns></returns>
         async Task<List<EFClient>[]> PollPlayersAsync()
         {
+            var tokenSource = new CancellationTokenSource();
+            tokenSource.CancelAfter(TimeSpan.FromSeconds(5));
             var currentClients = GetClientsAsList();
-            var statusResponse = await this.GetStatusAsync(Manager.CancellationToken);
+            var statusResponse = await this.GetStatusAsync(tokenSource.Token);
+
+            if (statusResponse is null)
+            {
+                return null;
+            }
+            
             var polledClients = statusResponse.Clients.AsEnumerable();
 
             if (Manager.GetApplicationSettings().Configuration().IgnoreBots)
@@ -930,6 +938,11 @@ namespace IW4MAdmin
 
                     var polledClients = await PollPlayersAsync();
 
+                    if (polledClients is null)
+                    {
+                        return true;
+                    }
+
                     foreach (var disconnectingClient in polledClients[1]
                                  .Where(client => !client.IsZombieClient /* ignores "fake" zombie clients */))
                     {

Application/Misc/AsyncResult.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Threading;
+
+namespace IW4MAdmin.Application.Misc;
+
+public class AsyncResult : IAsyncResult
+{
+    public object AsyncState { get; set; }
+    public WaitHandle AsyncWaitHandle { get; set; }
+    public bool CompletedSynchronously { get; set; }
+    public bool IsCompleted { get; set; }
+}

Application/Misc/ScriptPlugin.cs

@@ -276,8 +276,8 @@ namespace IW4MAdmin.Application.Misc
             {
                 _logger.LogDebug("OnLoad executing for {Name}", Name);
                 _scriptEngine.SetValue("_manager", manager);
-                _scriptEngine.SetValue("getDvar", GetDvarAsync);
+                _scriptEngine.SetValue("getDvar", BeginGetDvar);
-                _scriptEngine.SetValue("setDvar", SetDvarAsync);
+                _scriptEngine.SetValue("setDvar", BeginSetDvar);
                 _scriptEngine.Evaluate("plugin.onLoadAsync(_manager)");
 
                 return Task.CompletedTask;
@@ -343,7 +343,8 @@ namespace IW4MAdmin.Application.Misc
         /// <param name="commands">commands value from jint parser</param>
         /// <param name="scriptCommandFactory">factory to create the command from</param>
         /// <returns></returns>
-        private IEnumerable<IManagerCommand> GenerateScriptCommands(JsValue commands, IScriptCommandFactory scriptCommandFactory)
+        private IEnumerable<IManagerCommand> GenerateScriptCommands(JsValue commands,
+            IScriptCommandFactory scriptCommandFactory)
         {
             var commandList = new List<IManagerCommand>();
 
@@ -410,7 +411,7 @@ namespace IW4MAdmin.Application.Misc
 
                         _scriptEngine.SetValue("_event", gameEvent);
                         var jsEventObject = _scriptEngine.Evaluate("_event");
-                        
+
                         dynamicCommand.execute.Target.Invoke(_scriptEngine, jsEventObject);
                     }
 
@@ -424,7 +425,7 @@ namespace IW4MAdmin.Application.Misc
 
                         throw new PluginException("A runtime error occured while executing action for script plugin");
                     }
-                    
+
                     catch (Exception ex)
                     {
                         using (LogContext.PushProperty("Server", gameEvent.Owner?.ToString()))
@@ -454,83 +455,71 @@ namespace IW4MAdmin.Application.Misc
             return commandList;
         }
 
-        private void GetDvarAsync(Server server, string dvarName, Delegate onCompleted)
+        private void BeginGetDvar(Server server, string dvarName, Delegate onCompleted)
         {
-            Task.Run(() =>
+            var tokenSource = new CancellationTokenSource();
+            tokenSource.CancelAfter(TimeSpan.FromSeconds(15));
+            
+            server.BeginGetDvar(dvarName, result =>
             {
-                var tokenSource = new CancellationTokenSource();
+                var shouldRelease = false;
-                tokenSource.CancelAfter(TimeSpan.FromSeconds(5));
-                string result = null;
-                var success = true;
                 try
                 {
-                    result = server.GetDvarAsync<string>(dvarName, token: tokenSource.Token).GetAwaiter().GetResult().Value;
+                    _onProcessing.Wait(tokenSource.Token);
-                }
+                    shouldRelease = true;
-                catch
+                    var (success, value) = (ValueTuple<bool, string>)result.AsyncState;
-                {
-                    success = false;
-                }
 
-                _onProcessing.Wait();
-                try
-                {
-                    onCompleted.DynamicInvoke(JsValue.Undefined,
-                        new[]
-                        {
-                            JsValue.FromObject(_scriptEngine, server), 
-                            JsValue.FromObject(_scriptEngine, dvarName),
-                            JsValue.FromObject(_scriptEngine, result),
-                            JsValue.FromObject(_scriptEngine, success), 
-                        });
-                }
-
-                finally
-                {
-                    if (_onProcessing.CurrentCount == 0)
-                    {
-                        _onProcessing.Release();
-                    }
-                }
-            });
-        }
-        private void SetDvarAsync(Server server, string dvarName, string dvarValue, Delegate onCompleted)
-        {
-            Task.Run(() =>
-            {
-                var tokenSource = new CancellationTokenSource();
-                tokenSource.CancelAfter(TimeSpan.FromSeconds(5));
-                var success = true;
-
-                try
-                {
-                    server.SetDvarAsync(dvarName, dvarValue, tokenSource.Token).GetAwaiter().GetResult();
-                }
-                catch
-                {
-                    success = false;
-                }
-
-                _onProcessing.Wait();
-                try
-                {
                     onCompleted.DynamicInvoke(JsValue.Undefined,
                         new[]
                         {
                             JsValue.FromObject(_scriptEngine, server),
-                            JsValue.FromObject(_scriptEngine, dvarName), 
+                            JsValue.FromObject(_scriptEngine, dvarName),
-                            JsValue.FromObject(_scriptEngine, dvarValue),
+                            JsValue.FromObject(_scriptEngine, value),
                             JsValue.FromObject(_scriptEngine, success)
                         });
                 }
 
                 finally
                 {
-                    if (_onProcessing.CurrentCount == 0)
+                    if (_onProcessing.CurrentCount == 0 && shouldRelease)
                     {
                         _onProcessing.Release();
                     }
                 }
-            });
+            }, tokenSource.Token);
+        }
+
+        private void BeginSetDvar(Server server, string dvarName, string dvarValue, Delegate onCompleted)
+        {
+            var tokenSource = new CancellationTokenSource();
+            tokenSource.CancelAfter(TimeSpan.FromSeconds(15));
+            
+            server.BeginSetDvar(dvarName, dvarValue, result =>
+            {
+                var shouldRelease = false;
+                try
+                {
+                    _onProcessing.Wait(tokenSource.Token);
+                    shouldRelease = true;
+                    var success = (bool)result.AsyncState;
+                    
+                    onCompleted.DynamicInvoke(JsValue.Undefined,
+                        new[]
+                        {
+                            JsValue.FromObject(_scriptEngine, server),
+                            JsValue.FromObject(_scriptEngine, dvarName),
+                            JsValue.FromObject(_scriptEngine, dvarValue),
+                            JsValue.FromObject(_scriptEngine, success)
+                        });
+                }
+                finally
+                {
+                    if (_onProcessing.CurrentCount == 0 && shouldRelease)
+                    {
+                        _onProcessing.Release();
+                    }
+                }
+            }, tokenSource.Token);
         }
     }
 

Application/RConParsers/BaseRConParser.cs

@@ -10,6 +10,7 @@ using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
 using Data.Models;
+using IW4MAdmin.Application.Misc;
 using Microsoft.Extensions.Logging;
 using static SharedLibraryCore.Server;
 using ILogger = Microsoft.Extensions.Logging.ILogger;
@@ -141,6 +142,30 @@ namespace IW4MAdmin.Application.RConParsers
             };
         }
 
+        public void BeginGetDvar(IRConConnection connection, string dvarName, AsyncCallback callback, CancellationToken token = default)
+        {
+            GetDvarAsync<string>(connection, dvarName, token: token).ContinueWith(action =>
+            {
+                if (action.Exception is null)
+                {
+                    callback?.Invoke(new AsyncResult
+                    {
+                        IsCompleted = true,
+                        AsyncState = (true, action.Result.Value)
+                    });
+                }
+
+                else
+                {
+                    callback?.Invoke(new AsyncResult
+                    {
+                        IsCompleted = true,
+                        AsyncState = (false, (string)null)
+                    });
+                }
+            }, token);
+        }
+
         public virtual async Task<IStatusResponse> GetStatusAsync(IRConConnection connection, CancellationToken token = default)
         {
             var response = await connection.SendQueryAsync(StaticHelpers.QueryType.COMMAND_STATUS, "status", token);
@@ -196,6 +221,31 @@ namespace IW4MAdmin.Application.RConParsers
             return (await connection.SendQueryAsync(StaticHelpers.QueryType.SET_DVAR, dvarString, token)).Length > 0;
         }
 
+        public void BeginSetDvar(IRConConnection connection, string dvarName, object dvarValue, AsyncCallback callback,
+            CancellationToken token = default)
+        {
+            SetDvarAsync(connection, dvarName, dvarValue, token).ContinueWith(action =>
+            {
+                if (action.Exception is null)
+                {
+                    callback?.Invoke(new AsyncResult
+                    {
+                        IsCompleted = true,
+                        AsyncState = true
+                    });
+                }
+
+                else
+                {
+                    callback?.Invoke(new AsyncResult
+                    {
+                        IsCompleted = true,
+                        AsyncState = false
+                    });
+                }
+            }, token);
+        }
+
         private List<EFClient> ClientsFromStatus(string[] Status)
         {
             List<EFClient> StatusPlayers = new List<EFClient>();

SharedLibraryCore/Interfaces/IRConParser.cs

@@ -55,6 +55,8 @@ namespace SharedLibraryCore.Interfaces
         /// <param name="token"></param>
         /// <returns></returns>
         Task<Dvar<T>> GetDvarAsync<T>(IRConConnection connection, string dvarName, T fallbackValue = default, CancellationToken token = default);
+        
+        void BeginGetDvar(IRConConnection connection, string dvarName, AsyncCallback callback, CancellationToken token = default);
 
         /// <summary>
         ///     set value of DVAR by name
@@ -65,6 +67,8 @@ namespace SharedLibraryCore.Interfaces
         /// <param name="token"></param>
         /// <returns></returns>
         Task<bool> SetDvarAsync(IRConConnection connection, string dvarName, object dvarValue, CancellationToken token = default);
+        
+        void BeginSetDvar(IRConConnection connection, string dvarName, object dvarValue, AsyncCallback callback, CancellationToken token = default);
 
         /// <summary>
         ///     executes a console command on the server

SharedLibraryCore/Utilities.cs

@@ -773,6 +773,11 @@ namespace SharedLibraryCore
         {
             return await server.RconParser.GetDvarAsync(server.RemoteConnection, dvarName, fallbackValue, token);
         }
+
+        public static void BeginGetDvar(this Server server, string dvarName, AsyncCallback callback, CancellationToken token = default)
+        {
+            server.RconParser.BeginGetDvar(server.RemoteConnection, dvarName, callback, token);
+        }
         
         public static async Task<Dvar<T>> GetDvarAsync<T>(this Server server, string dvarName,
             T fallbackValue = default)
@@ -808,6 +813,12 @@ namespace SharedLibraryCore
         {
             await server.RconParser.SetDvarAsync(server.RemoteConnection, dvarName, dvarValue, token);
         }
+
+        public static void BeginSetDvar(this Server server, string dvarName, object dvarValue,
+            AsyncCallback callback, CancellationToken token = default)
+        {
+            server.RconParser.BeginSetDvar(server.RemoteConnection, dvarName, dvarValue, callback, token);
+        }
         
         public static async Task SetDvarAsync(this Server server, string dvarName, object dvarValue)
         {
@@ -824,9 +835,17 @@ namespace SharedLibraryCore
             return await ExecuteCommandAsync(server, commandName, default);
         }
 
-        public static Task<IStatusResponse> GetStatusAsync(this Server server, CancellationToken token)
+        public static async Task<IStatusResponse> GetStatusAsync(this Server server, CancellationToken token)
         {
-            return server.RconParser.GetStatusAsync(server.RemoteConnection, token);
+            try
+            {
+                return await server.RconParser.GetStatusAsync(server.RemoteConnection, token);
+            }
+
+            catch (TaskCanceledException)
+            {
+                return null;
+            }
         }
 
         /// <summary>