Add "servermods" folder to ignored folders in backups

Caused by 72ddaf91.

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "dotnet-ef": {
-      "version": "7.0.0-rc.1.22426.7",
+      "version": "8.0.3",
       "commands": [
         "dotnet-ef"
       ]

Agent/Phantom.Agent.Minecraft/Instance/InstanceProcess.cs

@@ -1,5 +1,6 @@
 using Phantom.Utils.Collections;
 using Phantom.Utils.Processes;
+using Phantom.Utils.Tasks;
 
 namespace Phantom.Agent.Minecraft.Instance;
 
@@ -13,6 +14,7 @@ public sealed class InstanceProcess : IDisposable {
 	public bool HasEnded { get; private set; }
 
 	private readonly Process process;
+	private readonly TaskCompletionSource processExited = AsyncTasks.CreateCompletionSource();
 
 	internal InstanceProcess(InstanceProperties instanceProperties, Process process) {
 		this.InstanceProperties = instanceProperties;
@@ -46,16 +48,15 @@ public sealed class InstanceProcess : IDisposable {
 		OutputEvent = null;
 		HasEnded = true;
 		Ended?.Invoke(this, EventArgs.Empty);
+		processExited.SetResult();
 	}
 
 	public void Kill() {
 		process.Kill(true);
 	}
 
-	public async Task WaitForExit(CancellationToken cancellationToken) {
-		if (!HasEnded) {
-			await process.WaitForExitAsync(cancellationToken);
-		}
+	public async Task WaitForExit(TimeSpan timeout) {
+		await processExited.Task.WaitAsync(timeout);
 	}
 
 	public void Dispose() {

Agent/Phantom.Agent.Minecraft/Java/JavaRuntimeDiscovery.cs

@@ -1,7 +1,7 @@
 using System.Diagnostics;
 using Phantom.Common.Data.Java;
-using Phantom.Common.Logging;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Minecraft.Java;

Agent/Phantom.Agent.Minecraft/Launcher/BaseLauncher.cs

@@ -1,4 +1,5 @@
-using System.Text;
+using System.Collections.ObjectModel;
+using System.Text;
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Server;
@@ -11,6 +12,7 @@ public abstract class BaseLauncher : IServerLauncher {
 	private readonly InstanceProperties instanceProperties;
 
 	protected string MinecraftVersion => instanceProperties.ServerVersion;
+	protected string InstanceFolder => instanceProperties.InstanceFolder;
 
 	private protected BaseLauncher(InstanceProperties instanceProperties) {
 		this.instanceProperties = instanceProperties;
@@ -51,16 +53,14 @@ public abstract class BaseLauncher : IServerLauncher {
 		
 		var processConfigurator = new ProcessConfigurator {
 			FileName = javaRuntimeExecutable.ExecutablePath,
-			WorkingDirectory = instanceProperties.InstanceFolder,
+			WorkingDirectory = InstanceFolder,
 			RedirectInput = true,
 			UseShellExecute = false
 		};
 		
 		var processArguments = processConfigurator.ArgumentList;
 		PrepareJvmArguments(serverJar).Build(processArguments);
-		processArguments.Add("-jar");
-		processArguments.Add(serverJar.FilePath);
-		processArguments.Add("nogui");
+		PrepareJavaProcessArguments(processArguments, serverJar.FilePath);
 
 		var process = processConfigurator.CreateProcess();
 		var instanceProcess = new InstanceProcess(instanceProperties, process);
@@ -99,6 +99,12 @@ public abstract class BaseLauncher : IServerLauncher {
 
 	private protected virtual void CustomizeJvmArguments(JvmArgumentBuilder arguments) {}
 
+	protected virtual void PrepareJavaProcessArguments(Collection<string> processArguments, string serverJarFilePath) {
+		processArguments.Add("-jar");
+		processArguments.Add(serverJarFilePath);
+		processArguments.Add("nogui");
+	}
+
 	private protected virtual Task<ServerJarInfo> PrepareServerJar(ILogger logger, string serverJarPath, CancellationToken cancellationToken) {
 		return Task.FromResult(new ServerJarInfo(serverJarPath));
 	}

Agent/Phantom.Agent.Minecraft/Launcher/Types/ForgeLauncher.cs

@@ -0,0 +1,29 @@
+using System.Collections.ObjectModel;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Java;
+using Serilog;
+
+namespace Phantom.Agent.Minecraft.Launcher.Types; 
+
+public sealed class ForgeLauncher : BaseLauncher {
+	public ForgeLauncher(InstanceProperties instanceProperties) : base(instanceProperties) {}
+	
+	private protected override void CustomizeJvmArguments(JvmArgumentBuilder arguments) {
+		arguments.AddProperty("terminal.ansi", "true"); // TODO
+	}
+
+	protected override void PrepareJavaProcessArguments(Collection<string> processArguments, string serverJarFilePath) {
+		if (OperatingSystem.IsWindows()) {
+			processArguments.Add("@libraries/net/minecraftforge/forge/1.20.1-47.2.0/win_args.txt");
+		}
+		else {
+			processArguments.Add("@libraries/net/minecraftforge/forge/1.20.1-47.2.0/unix_args.txt");
+		}
+		
+		processArguments.Add("nogui");
+	}
+
+	private protected override Task<ServerJarInfo> PrepareServerJar(ILogger logger, string serverJarPath, CancellationToken cancellationToken) {
+		return Task.FromResult(new ServerJarInfo(Path.Combine(InstanceFolder, "run.sh")));
+	}
+}

Agent/Phantom.Agent.Minecraft/Phantom.Agent.Minecraft.csproj

@@ -11,8 +11,8 @@
   
   <ItemGroup>
     <ProjectReference Include="..\..\Common\Phantom.Common.Data\Phantom.Common.Data.csproj" />
-    <ProjectReference Include="..\..\Common\Phantom.Common.Logging\Phantom.Common.Logging.csproj" />
     <ProjectReference Include="..\..\Utils\Phantom.Utils\Phantom.Utils.csproj" />
+    <ProjectReference Include="..\..\Utils\Phantom.Utils.Logging\Phantom.Utils.Logging.csproj" />
   </ItemGroup>
 
 </Project>

Agent/Phantom.Agent.Minecraft/Properties/MinecraftServerProperties.cs

@@ -18,4 +18,5 @@ static class MinecraftServerProperties {
 	public static readonly MinecraftServerProperty<ushort> ServerPort = new UnsignedShort("server-port");
 	public static readonly MinecraftServerProperty<ushort> RconPort = new UnsignedShort("rcon.port");
 	public static readonly MinecraftServerProperty<bool> EnableRcon = new Boolean("enable-rcon");
+	public static readonly MinecraftServerProperty<bool> SyncChunkWrites = new Boolean("sync-chunk-writes");
 }

Agent/Phantom.Agent.Minecraft/Properties/ServerProperties.cs

@@ -5,11 +5,13 @@ namespace Phantom.Agent.Minecraft.Properties;
 public sealed record ServerProperties(
 	ushort ServerPort,
 	ushort RconPort,
-	bool EnableRcon = true
+	bool EnableRcon = true,
+	bool SyncChunkWrites = false
 ) {
 	internal void SetTo(JavaPropertiesFileEditor properties) {
 		MinecraftServerProperties.ServerPort.Set(properties, ServerPort);
 		MinecraftServerProperties.RconPort.Set(properties, RconPort);
 		MinecraftServerProperties.EnableRcon.Set(properties, EnableRcon);
+		MinecraftServerProperties.SyncChunkWrites.Set(properties, SyncChunkWrites);
 	}
 }

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutableDownloader.cs

@@ -1,8 +1,8 @@
 using System.Security.Cryptography;
 using Phantom.Common.Data.Minecraft;
-using Phantom.Common.Logging;
 using Phantom.Utils.Cryptography;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Phantom.Utils.Runtime;
 using Serilog;
 
@@ -16,32 +16,47 @@ sealed class MinecraftServerExecutableDownloader {
 	public event EventHandler? Completed;
 	
 	private readonly CancellationTokenSource cancellationTokenSource = new ();
-	private int listeners = 0;
+	
+	private readonly List<CancellationTokenRegistration> listenerCancellationRegistrations = new ();
+	private int listenerCount = 0;
 
 	public MinecraftServerExecutableDownloader(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath, MinecraftServerExecutableDownloadListener listener) {
 		Register(listener);
-		Task = DownloadAndGetPath(fileDownloadInfo, minecraftVersion, filePath);
+		Task = DownloadAndGetPath(fileDownloadInfo, minecraftVersion, filePath, new DownloadProgressCallback(this), cancellationTokenSource.Token);
 		Task.ContinueWith(OnCompleted, TaskScheduler.Default);
 	}
 
 	public void Register(MinecraftServerExecutableDownloadListener listener) {
-		++listeners;
-		Logger.Debug("Registered download listener, current listener count: {Listeners}", listeners);
+		int newListenerCount;
 		
-		DownloadProgress += listener.DownloadProgressEventHandler;
-		listener.CancellationToken.Register(Unregister, listener);
+		lock (this) {
+			newListenerCount = ++listenerCount;
+			
+			DownloadProgress += listener.DownloadProgressEventHandler;
+			listenerCancellationRegistrations.Add(listener.CancellationToken.Register(Unregister, listener));
+		}
+		
+		Logger.Debug("Registered download listener, current listener count: {Listeners}", newListenerCount);
 	}
 
 	private void Unregister(object? listenerObject) {
-		MinecraftServerExecutableDownloadListener listener = (MinecraftServerExecutableDownloadListener) listenerObject!;
-		DownloadProgress -= listener.DownloadProgressEventHandler;
+		int newListenerCount;
+		
+		lock (this) {
+			MinecraftServerExecutableDownloadListener listener = (MinecraftServerExecutableDownloadListener) listenerObject!;
+			DownloadProgress -= listener.DownloadProgressEventHandler;
 
-		if (--listeners <= 0) {
+			newListenerCount = --listenerCount;
+			if (newListenerCount <= 0) {
+				cancellationTokenSource.Cancel();
+			}
+		}
+		
+		if (newListenerCount <= 0) {
 			Logger.Debug("Unregistered last download listener, cancelling download.");
-			cancellationTokenSource.Cancel();
 		}
 		else {
-			Logger.Debug("Unregistered download listener, current listener count: {Listeners}", listeners);
+			Logger.Debug("Unregistered download listener, current listener count: {Listeners}", newListenerCount);
 		}
 	}
 
@@ -51,9 +66,19 @@ sealed class MinecraftServerExecutableDownloader {
 
 	private void OnCompleted(Task task) {
 		Logger.Debug("Download task completed.");
-		Completed?.Invoke(this, EventArgs.Empty);
-		Completed = null;
-		DownloadProgress = null;
+
+		lock (this) {
+			Completed?.Invoke(this, EventArgs.Empty);
+			Completed = null;
+			DownloadProgress = null;
+
+			foreach (var registration in listenerCancellationRegistrations) {
+				registration.Dispose();
+			}
+			
+			listenerCancellationRegistrations.Clear();
+			cancellationTokenSource.Dispose();
+		}
 	}
 
 	private sealed class DownloadProgressCallback {
@@ -68,15 +93,14 @@ sealed class MinecraftServerExecutableDownloader {
 		}
 	}
 
-	private async Task<string?> DownloadAndGetPath(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath) {
+	private static async Task<string?> DownloadAndGetPath(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath, DownloadProgressCallback progressCallback, CancellationToken cancellationToken) {
 		string tmpFilePath = filePath + ".tmp";
 
-		var cancellationToken = cancellationTokenSource.Token;
 		try {
 			Logger.Information("Downloading server version {Version} from: {Url} ({Size})", minecraftVersion, fileDownloadInfo.DownloadUrl, fileDownloadInfo.Size.ToHumanReadable(decimalPlaces: 1));
 			try {
 				using var http = new HttpClient();
-				await FetchServerExecutableFile(http, new DownloadProgressCallback(this), fileDownloadInfo, tmpFilePath, cancellationToken);
+				await FetchServerExecutableFile(http, progressCallback, fileDownloadInfo, tmpFilePath, cancellationToken);
 			} catch (Exception) {
 				TryDeleteExecutableAfterFailure(tmpFilePath);
 				throw;
@@ -94,8 +118,6 @@ sealed class MinecraftServerExecutableDownloader {
 		} catch (Exception e) {
 			Logger.Error(e, "An unexpected error occurred.");
 			return null;
-		} finally {
-			cancellationTokenSource.Dispose();
 		}
 	}
 

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutables.cs

@@ -1,7 +1,7 @@
 using System.Text.RegularExpressions;
 using Phantom.Common.Data.Minecraft;
-using Phantom.Common.Logging;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Minecraft.Server;

Agent/Phantom.Agent.Minecraft/Server/ServerStatusProtocol.cs

@@ -3,28 +3,12 @@ using System.Buffers.Binary;
 using System.Net;
 using System.Net.Sockets;
 using System.Text;
-using Phantom.Common.Logging;
-using Serilog;
+using Phantom.Common.Data.Instance;
 
 namespace Phantom.Agent.Minecraft.Server;
 
-public sealed class ServerStatusProtocol {
-	private readonly ILogger logger;
-
-	public ServerStatusProtocol(string loggerName) {
-		this.logger = PhantomLogger.Create<ServerStatusProtocol>(loggerName);
-	}
-
-	public async Task<int?> GetOnlinePlayerCount(int serverPort, CancellationToken cancellationToken) {
-		try {
-			return await GetOnlinePlayerCountOrThrow(serverPort, cancellationToken);
-		} catch (Exception e) {
-			logger.Error(e, "Caught exception while checking if players are online.");
-			return null;
-		}
-	}
-
-	private async Task<int?> GetOnlinePlayerCountOrThrow(int serverPort, CancellationToken cancellationToken) {
+public static class ServerStatusProtocol {
+	public static async Task<InstancePlayerCounts> GetPlayerCounts(ushort serverPort, CancellationToken cancellationToken) {
 		using var tcpClient = new TcpClient();
 		await tcpClient.ConnectAsync(IPAddress.Loopback, serverPort, cancellationToken);
 		var tcpStream = tcpClient.GetStream();
@@ -33,24 +17,22 @@ public sealed class ServerStatusProtocol {
 		tcpStream.WriteByte(0xFE);
 		await tcpStream.FlushAsync(cancellationToken);
 
-		short? messageLength = await ReadStreamHeader(tcpStream, cancellationToken);
-		return messageLength == null ? null : await ReadOnlinePlayerCount(tcpStream, messageLength.Value * 2, cancellationToken);
+		short messageLength = await ReadStreamHeader(tcpStream, cancellationToken);
+		return await ReadPlayerCounts(tcpStream, messageLength * 2, cancellationToken);
 	}
 
-	private async Task<short?> ReadStreamHeader(NetworkStream tcpStream, CancellationToken cancellationToken) {
+	private static async Task<short> ReadStreamHeader(NetworkStream tcpStream, CancellationToken cancellationToken) {
 		var headerBuffer = ArrayPool<byte>.Shared.Rent(3);
 		try {
 			await tcpStream.ReadExactlyAsync(headerBuffer, 0, 3, cancellationToken);
 
 			if (headerBuffer[0] != 0xFF) {
-				logger.Error("Unexpected first byte in response from server: {FirstByte}.", headerBuffer[0]);
-				return null;
+				throw new ProtocolException("Unexpected first byte in response from server: " + headerBuffer[0]);
 			}
 
 			short messageLength = BinaryPrimitives.ReadInt16BigEndian(headerBuffer.AsSpan(1));
 			if (messageLength <= 0) {
-				logger.Error("Unexpected message length in response from server: {MessageLength}.", messageLength);
-				return null;
+				throw new ProtocolException("Unexpected message length in response from server: " + messageLength);
 			}
 			
 			return messageLength;
@@ -59,35 +41,54 @@ public sealed class ServerStatusProtocol {
 		}
 	}
 
-	private async Task<int?> ReadOnlinePlayerCount(NetworkStream tcpStream, int messageLength, CancellationToken cancellationToken) {
+	private static async Task<InstancePlayerCounts> ReadPlayerCounts(NetworkStream tcpStream, int messageLength, CancellationToken cancellationToken) {
 		var messageBuffer = ArrayPool<byte>.Shared.Rent(messageLength);
 		try {
 			await tcpStream.ReadExactlyAsync(messageBuffer, 0, messageLength, cancellationToken);
-
-			// Valid response separator encoded in UTF-16BE is 0x00 0xA7 (§).
-			const byte SeparatorSecondByte = 0xA7;
-			
-			static bool IsValidSeparator(ReadOnlySpan<byte> buffer, int index) {
-				return index > 0 && buffer[index - 1] == 0x00;
-			}
-			
-			int separator2 = Array.LastIndexOf(messageBuffer, SeparatorSecondByte);
-			int separator1 = separator2 == -1 ? -1 : Array.LastIndexOf(messageBuffer, SeparatorSecondByte, separator2 - 1);
-			if (!IsValidSeparator(messageBuffer, separator1) || !IsValidSeparator(messageBuffer, separator2)) {
-				logger.Error("Could not find message separators in response from server.");
-				return null;
-			}
-
-			string onlinePlayerCountStr = Encoding.BigEndianUnicode.GetString(messageBuffer.AsSpan((separator1 + 1)..(separator2 - 1)));
-			if (!int.TryParse(onlinePlayerCountStr, out int onlinePlayerCount)) {
-				logger.Error("Could not parse online player count in response from server: {OnlinePlayerCount}.", onlinePlayerCountStr);
-				return null;
-			}
-			
-			logger.Debug("Detected {OnlinePlayerCount} online player(s).", onlinePlayerCount);
-			return onlinePlayerCount;
+			return ReadPlayerCountsFromResponse(messageBuffer.AsSpan(0, messageLength));
 		} finally {
 			ArrayPool<byte>.Shared.Return(messageBuffer);
 		}
 	}
+	
+	/// <summary>
+	/// Legacy query protocol uses the paragraph symbol (§) as separator encoded in UTF-16BE.
+	/// </summary>
+	private static readonly byte[] Separator = { 0x00, 0xA7 };
+	
+	private static InstancePlayerCounts ReadPlayerCountsFromResponse(ReadOnlySpan<byte> messageBuffer) {
+		int lastSeparator = messageBuffer.LastIndexOf(Separator);
+		int middleSeparator = messageBuffer[..lastSeparator].LastIndexOf(Separator);
+		
+		if (lastSeparator == -1 || middleSeparator == -1) {
+			throw new ProtocolException("Could not find message separators in response from server.");
+		}
+
+		var onlinePlayerCountBuffer = messageBuffer[(middleSeparator + Separator.Length)..lastSeparator];
+		var maximumPlayerCountBuffer = messageBuffer[(lastSeparator + Separator.Length)..];
+		
+		// Player counts are integers, whose maximum string length is 10 characters.
+		Span<char> integerStringBuffer = stackalloc char[10];
+		
+		return new InstancePlayerCounts(
+			DecodeAndParsePlayerCount(onlinePlayerCountBuffer, integerStringBuffer, "online"),
+			DecodeAndParsePlayerCount(maximumPlayerCountBuffer, integerStringBuffer, "maximum")
+		);
+	}
+	
+	private static int DecodeAndParsePlayerCount(ReadOnlySpan<byte> inputBuffer, Span<char> tempCharBuffer, string countType) {
+		if (!Encoding.BigEndianUnicode.TryGetChars(inputBuffer, tempCharBuffer, out int charCount)) {
+			throw new ProtocolException("Could not decode " + countType + " player count in response from server.");
+		}
+		
+		if (!int.TryParse(tempCharBuffer, out int playerCount)) {
+			throw new ProtocolException("Could not parse " + countType + " player count in response from server: " + tempCharBuffer[..charCount].ToString());
+		}
+		
+		return playerCount;
+	}
+	
+	public sealed class ProtocolException : Exception {
+		internal ProtocolException(string message) : base(message) {}
+	}
 }

Agent/Phantom.Agent.Rpc/ControllerConnection.cs

@@ -1,6 +1,6 @@
-using Phantom.Common.Logging;
-using Phantom.Common.Messages.Agent;
-using Phantom.Utils.Rpc;
+using Phantom.Common.Messages.Agent;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Rpc.Runtime;
 using Serilog;
 
 namespace Phantom.Agent.Rpc;
@@ -8,9 +8,9 @@ namespace Phantom.Agent.Rpc;
 public sealed class ControllerConnection {
 	private static readonly ILogger Logger = PhantomLogger.Create(nameof(ControllerConnection));
 
-	private readonly RpcConnectionToServer<IMessageToControllerListener> connection;
+	private readonly RpcConnectionToServer<IMessageToController> connection;
 	
-	public ControllerConnection(RpcConnectionToServer<IMessageToControllerListener> connection) {
+	public ControllerConnection(RpcConnectionToServer<IMessageToController> connection) {
 		this.connection = connection;
 		Logger.Information("Connection ready.");
 	}

Agent/Phantom.Agent.Rpc/KeepAliveLoop.cs

@@ -1,7 +1,7 @@
-using Phantom.Common.Logging;
-using Phantom.Common.Messages.Agent;
+using Phantom.Common.Messages.Agent;
 using Phantom.Common.Messages.Agent.ToController;
-using Phantom.Utils.Rpc;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Rpc.Runtime;
 using Serilog;
 
 namespace Phantom.Agent.Rpc;
@@ -11,22 +11,24 @@ sealed class KeepAliveLoop {
 
 	private static readonly TimeSpan KeepAliveInterval = TimeSpan.FromSeconds(10);
 
-	private readonly RpcConnectionToServer<IMessageToControllerListener> connection;
+	private readonly RpcConnectionToServer<IMessageToController> connection;
 	private readonly CancellationTokenSource cancellationTokenSource = new ();
 
-	public KeepAliveLoop(RpcConnectionToServer<IMessageToControllerListener> connection) {
+	public KeepAliveLoop(RpcConnectionToServer<IMessageToController> connection) {
 		this.connection = connection;
 		Task.Run(Run);
 	}
 
 	private async Task Run() {
 		var cancellationToken = cancellationTokenSource.Token;
-
-		Logger.Information("Started keep-alive loop.");
+		
 		try {
+			await connection.IsReady.WaitAsync(cancellationToken);
+			Logger.Information("Started keep-alive loop.");
+			
 			while (true) {
 				await Task.Delay(KeepAliveInterval, cancellationToken);
-				await connection.Send(new AgentIsAliveMessage());
+				await connection.Send(new AgentIsAliveMessage()).WaitAsync(cancellationToken);
 			}
 		} catch (OperationCanceledException) {
 			// Ignore.

Agent/Phantom.Agent.Rpc/RpcClientRuntime.cs

@@ -1,33 +1,32 @@
 using NetMQ;
 using NetMQ.Sockets;
-using Phantom.Common.Data.Agent;
 using Phantom.Common.Messages.Agent;
 using Phantom.Common.Messages.Agent.BiDirectional;
 using Phantom.Common.Messages.Agent.ToController;
-using Phantom.Utils.Rpc;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Rpc.Runtime;
 using Phantom.Utils.Rpc.Sockets;
-using Phantom.Utils.Tasks;
 using Serilog;
 
 namespace Phantom.Agent.Rpc;
 
-public sealed class RpcClientRuntime : RpcClientRuntime<IMessageToAgentListener, IMessageToControllerListener, ReplyMessage> {
-	public static Task Launch(RpcClientSocket<IMessageToAgentListener, IMessageToControllerListener, ReplyMessage> socket, AgentInfo agentInfo, IMessageToAgentListener messageListener, SemaphoreSlim disconnectSemaphore, CancellationToken receiveCancellationToken) {
-		return new RpcClientRuntime(socket, messageListener, disconnectSemaphore, receiveCancellationToken).Launch();
+public sealed class RpcClientRuntime : RpcClientRuntime<IMessageToAgent, IMessageToController, ReplyMessage> {
+	public static Task Launch(RpcClientSocket<IMessageToAgent, IMessageToController, ReplyMessage> socket, ActorRef<IMessageToAgent> handlerActorRef, SemaphoreSlim disconnectSemaphore, CancellationToken receiveCancellationToken) {
+		return new RpcClientRuntime(socket, handlerActorRef, disconnectSemaphore, receiveCancellationToken).Launch();
 	}
 
-	private RpcClientRuntime(RpcClientSocket<IMessageToAgentListener, IMessageToControllerListener, ReplyMessage> socket, IMessageToAgentListener messageListener, SemaphoreSlim disconnectSemaphore, CancellationToken receiveCancellationToken) : base(socket, messageListener, disconnectSemaphore, receiveCancellationToken) {}
+	private RpcClientRuntime(RpcClientSocket<IMessageToAgent, IMessageToController, ReplyMessage> socket, ActorRef<IMessageToAgent> handlerActor, SemaphoreSlim disconnectSemaphore, CancellationToken receiveCancellationToken) : base(socket, handlerActor, disconnectSemaphore, receiveCancellationToken) {}
 
-	protected override void RunWithConnection(ClientSocket socket, RpcConnectionToServer<IMessageToControllerListener> connection, ILogger logger, TaskManager taskManager) {
+	protected override async Task RunWithConnection(ClientSocket socket, RpcConnectionToServer<IMessageToController> connection) {
 		var keepAliveLoop = new KeepAliveLoop(connection);
 		try {
-			base.RunWithConnection(socket, connection, logger, taskManager);
+			await base.RunWithConnection(socket, connection);
 		} finally {
 			keepAliveLoop.Cancel();
 		}
 	}
 
-	protected override async Task Disconnect(ClientSocket socket, ILogger logger) {
+	protected override async Task SendDisconnectMessage(ClientSocket socket, ILogger logger) {
 		var unregisterMessageBytes = AgentMessageRegistries.ToController.Write(new UnregisterAgentMessage()).ToArray();
 		try {
 			await socket.SendAsync(unregisterMessageBytes).AsTask().WaitAsync(TimeSpan.FromSeconds(5), CancellationToken.None);

Agent/Phantom.Agent.Services/AgentFolders.cs

@@ -1,5 +1,5 @@
-using Phantom.Common.Logging;
-using Phantom.Utils.IO;
+using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Services;

Agent/Phantom.Agent.Services/AgentServices.cs

@@ -1,10 +1,11 @@
-using Phantom.Agent.Minecraft.Java;
+using Akka.Actor;
+using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Rpc;
 using Phantom.Agent.Services.Backups;
 using Phantom.Agent.Services.Instances;
 using Phantom.Common.Data.Agent;
-using Phantom.Common.Logging;
-using Phantom.Utils.Tasks;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Services;
@@ -12,19 +13,28 @@ namespace Phantom.Agent.Services;
 public sealed class AgentServices {
 	private static readonly ILogger Logger = PhantomLogger.Create<AgentServices>();
 	
+	public ActorSystem ActorSystem { get; }
+
 	private AgentFolders AgentFolders { get; }
-	private TaskManager TaskManager { get; }
+	private AgentState AgentState { get; }
 	private BackupManager BackupManager { get; }
 
 	internal JavaRuntimeRepository JavaRuntimeRepository { get; }
-	internal InstanceSessionManager InstanceSessionManager { get; }
+	internal InstanceTicketManager InstanceTicketManager { get; }
+	internal ActorRef<InstanceManagerActor.ICommand> InstanceManager { get; }
 
 	public AgentServices(AgentInfo agentInfo, AgentFolders agentFolders, AgentServiceConfiguration serviceConfiguration, ControllerConnection controllerConnection) {
+		this.ActorSystem = ActorSystemFactory.Create("Agent");
+		
 		this.AgentFolders = agentFolders;
-		this.TaskManager = new TaskManager(PhantomLogger.Create<TaskManager, AgentServices>());
+		this.AgentState = new AgentState();
 		this.BackupManager = new BackupManager(agentFolders, serviceConfiguration.MaxConcurrentCompressionTasks);
+		
 		this.JavaRuntimeRepository = new JavaRuntimeRepository();
-		this.InstanceSessionManager = new InstanceSessionManager(controllerConnection, agentInfo, agentFolders, JavaRuntimeRepository, TaskManager, BackupManager);
+		this.InstanceTicketManager = new InstanceTicketManager(agentInfo, controllerConnection);
+		
+		var instanceManagerInit = new InstanceManagerActor.Init(controllerConnection, agentFolders, AgentState, JavaRuntimeRepository, InstanceTicketManager, BackupManager);
+		this.InstanceManager = ActorSystem.ActorOf(InstanceManagerActor.Factory(instanceManagerInit), "InstanceManager");
 	}
 
 	public async Task Initialize() {
@@ -36,11 +46,13 @@ public sealed class AgentServices {
 	public async Task Shutdown() {
 		Logger.Information("Stopping services...");
 		
-		await InstanceSessionManager.DisposeAsync();
-		await TaskManager.Stop();
+		await InstanceManager.Stop(new InstanceManagerActor.ShutdownCommand());
 		
 		BackupManager.Dispose();
 		
+		await ActorSystem.Terminate();
+		ActorSystem.Dispose();
+		
 		Logger.Information("Services stopped.");
 	}
 }

Agent/Phantom.Agent.Services/AgentState.cs

@@ -0,0 +1,15 @@
+using System.Collections.Immutable;
+using Phantom.Agent.Services.Instances;
+using Phantom.Utils.Actor.Event;
+
+namespace Phantom.Agent.Services;
+
+sealed class AgentState {
+	private readonly ObservableState<ImmutableDictionary<Guid, Instance>> instancesByGuid = new (ImmutableDictionary<Guid, Instance>.Empty);
+	
+	public ImmutableDictionary<Guid, Instance> InstancesByGuid => instancesByGuid.State;
+	
+	public void UpdateInstance(Instance instance) {
+		instancesByGuid.PublisherSide.Publish(static (instancesByGuid, instance) => instancesByGuid.SetItem(instance.InstanceGuid, instance), instance);
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupArchiver.cs

@@ -3,8 +3,8 @@ using System.Diagnostics.CodeAnalysis;
 using System.Formats.Tar;
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Common.Data.Backups;
-using Phantom.Common.Logging;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Services.Backups;
@@ -25,7 +25,7 @@ sealed class BackupArchiver {
 	}
 
 	private bool IsFolderSkipped(ImmutableList<string> relativePath) {
-		return relativePath is ["cache" or "crash-reports" or "debug" or "libraries" or "logs" or "mods" or "versions"];
+		return relativePath is ["cache" or "crash-reports" or "debug" or "libraries" or "logs" or "mods" or "servermods" or "versions"];
 	}
 	
 	[SuppressMessage("ReSharper", "ConvertIfStatementToReturnStatement")]

Agent/Phantom.Agent.Services/Backups/BackupCompressor.cs

@@ -1,4 +1,4 @@
-using Phantom.Common.Logging;
+using Phantom.Utils.Logging;
 using Phantom.Utils.Processes;
 using Serilog;
 

Agent/Phantom.Agent.Services/Backups/BackupManager.cs

@@ -1,6 +1,6 @@
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Common.Data.Backups;
-using Phantom.Common.Logging;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Services.Backups;
@@ -67,6 +67,10 @@ sealed class BackupManager : IDisposable {
 				resultBuilder.Kind = BackupCreationResultKind.BackupCancelled;
 				logger.Warning("Backup creation was cancelled.");
 				return null;
+			} catch (TimeoutException) {
+				resultBuilder.Kind = BackupCreationResultKind.BackupTimedOut;
+				logger.Warning("Backup creation timed out.");
+				return null;
 			} catch (Exception e) {
 				resultBuilder.Kind = BackupCreationResultKind.UnknownError;
 				logger.Error(e, "Caught exception while creating an instance backup.");
@@ -76,6 +80,9 @@ sealed class BackupManager : IDisposable {
 					await dispatcher.EnableAutomaticSaving();
 				} catch (OperationCanceledException) {
 					// Ignore.
+				} catch (TimeoutException) {
+					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotRestoreAutomaticSaving;
+					logger.Warning("Timed out waiting for automatic saving to be re-enabled.");
 				} catch (Exception e) {
 					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotRestoreAutomaticSaving;
 					logger.Error(e, "Caught exception while enabling automatic saving after creating an instance backup.");
@@ -120,6 +127,7 @@ sealed class BackupManager : IDisposable {
 				BackupCreationResultKind.Success                            => "Backup created successfully.",
 				BackupCreationResultKind.InstanceNotRunning                 => "Instance is not running.",
 				BackupCreationResultKind.BackupCancelled                    => "Backup cancelled.",
+				BackupCreationResultKind.BackupTimedOut                     => "Backup timed out.",
 				BackupCreationResultKind.BackupAlreadyRunning               => "A backup is already being created.",
 				BackupCreationResultKind.BackupFileAlreadyExists            => "Backup with the same name already exists.",
 				BackupCreationResultKind.CouldNotCreateBackupFolder         => "Could not create backup folder.",

Agent/Phantom.Agent.Services/Backups/BackupScheduler.cs

@@ -1,11 +1,8 @@
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Agent.Minecraft.Server;
-using Phantom.Agent.Services.Instances;
-using Phantom.Agent.Services.Instances.Procedures;
+using Phantom.Agent.Services.Instances;
+using Phantom.Agent.Services.Instances.State;
 using Phantom.Common.Data.Backups;
-using Phantom.Common.Logging;
+using Phantom.Utils.Logging;
 using Phantom.Utils.Tasks;
-using Phantom.Utils.Threading;
 
 namespace Phantom.Agent.Services.Backups;
 
@@ -16,28 +13,24 @@ sealed class BackupScheduler : CancellableBackgroundTask {
 	private static readonly TimeSpan BackupFailureRetryDelay = TimeSpan.FromMinutes(5);
 
 	private readonly BackupManager backupManager;
-	private readonly InstanceProcess process;
-	private readonly IInstanceContext context;
+	private readonly InstanceContext context;
 	private readonly SemaphoreSlim backupSemaphore = new (1, 1);
-	private readonly int serverPort;
-	private readonly ServerStatusProtocol serverStatusProtocol;
 	private readonly ManualResetEventSlim serverOutputWhileWaitingForOnlinePlayers = new ();
+	private readonly InstancePlayerCountTracker playerCountTracker;
 	
 	public event EventHandler<BackupCreationResult>? BackupCompleted;
 
-	public BackupScheduler(TaskManager taskManager, BackupManager backupManager, InstanceProcess process, IInstanceContext context, int serverPort) : base(PhantomLogger.Create<BackupScheduler>(context.ShortName), taskManager, "Backup scheduler for " + context.ShortName) {
-		this.backupManager = backupManager;
-		this.process = process;
+	public BackupScheduler(InstanceContext context, InstancePlayerCountTracker playerCountTracker) : base(PhantomLogger.Create<BackupScheduler>(context.ShortName)) {
+		this.backupManager = context.Services.BackupManager;
 		this.context = context;
-		this.serverPort = serverPort;
-		this.serverStatusProtocol = new ServerStatusProtocol(context.ShortName);
+		this.playerCountTracker = playerCountTracker;
 		Start();
 	}
 
 	protected override async Task RunTask() {
 		await Task.Delay(InitialDelay, CancellationToken);
 		Logger.Information("Starting a new backup after server launched.");
-			
+		
 		while (!CancellationToken.IsCancellationRequested) {
 			var result = await CreateBackup();
 			BackupCompleted?.Invoke(this, result);
@@ -60,52 +53,28 @@ sealed class BackupScheduler : CancellableBackgroundTask {
 		}
 		
 		try {
-			var procedure = new BackupInstanceProcedure(backupManager);
-			context.EnqueueProcedure(procedure);
-			return await procedure.Result;
+			context.ActorCancellationToken.ThrowIfCancellationRequested();
+			return await context.Actor.Request(new InstanceActor.BackupInstanceCommand(backupManager), context.ActorCancellationToken);
+		} catch (OperationCanceledException) {
+			return new BackupCreationResult(BackupCreationResultKind.InstanceNotRunning);
 		} finally {
 			backupSemaphore.Release();
 		}
 	}
 
 	private async Task WaitForOnlinePlayers() {
-		bool needsToLogOfflinePlayersMessage = true;
-		
-		process.AddOutputListener(ServerOutputListener, maxLinesToReadFromHistory: 0);
-		try {
-			while (!CancellationToken.IsCancellationRequested) {
-				serverOutputWhileWaitingForOnlinePlayers.Reset();
-				
-				var onlinePlayerCount = await serverStatusProtocol.GetOnlinePlayerCount(serverPort, CancellationToken);
-				if (onlinePlayerCount == null) {
-					Logger.Warning("Could not detect whether any players are online, starting a new backup.");
-					break;
-				}
-
-				if (onlinePlayerCount > 0) {
-					Logger.Information("Players are online, starting a new backup.");
-					break;
-				}
-
-				if (needsToLogOfflinePlayersMessage) {
-					needsToLogOfflinePlayersMessage = false;
-					Logger.Information("No players are online, waiting for someone to join before starting a new backup.");
-				}
-
-				await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
-				
-				Logger.Debug("Waiting for server output before checking for online players again...");
-				await serverOutputWhileWaitingForOnlinePlayers.WaitHandle.WaitOneAsync(CancellationToken);
-			}
-		} finally {
-			process.RemoveOutputListener(ServerOutputListener);
+		var task = playerCountTracker.WaitForOnlinePlayers(CancellationToken);
+		if (!task.IsCompleted) {
+			Logger.Information("Waiting for someone to join before starting a new backup.");
 		}
-	}
-
-	private void ServerOutputListener(object? sender, string line) {
-		if (!serverOutputWhileWaitingForOnlinePlayers.IsSet) {
-			serverOutputWhileWaitingForOnlinePlayers.Set();
-			Logger.Debug("Detected server output, signalling to check for online players again.");
+		
+		try {
+			await task;
+			Logger.Information("Players are online, starting a new backup.");
+		} catch (OperationCanceledException) {
+			throw;
+		} catch (Exception) {
+			Logger.Warning("Could not detect whether any players are online, starting a new backup.");
 		}
 	}
 

Agent/Phantom.Agent.Services/Backups/BackupServerCommandDispatcher.cs

@@ -1,4 +1,5 @@
-using System.Text.RegularExpressions;
+using System.Collections.Immutable;
+using System.Text.RegularExpressions;
 using Phantom.Agent.Minecraft.Command;
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Utils.Tasks;
@@ -7,8 +8,26 @@ using Serilog;
 namespace Phantom.Agent.Services.Backups;
 
 sealed partial class BackupServerCommandDispatcher : IDisposable {
-	[GeneratedRegex(@"^\[(?:.*?)\] \[Server thread/INFO\]: (.*?)$", RegexOptions.NonBacktracking)]
+	[GeneratedRegex(@"^(?:(?:\[.*?\] \[Server thread/INFO\].*?:)|(?:[\d-]+? [\d:]+? \[INFO\])) (.*?)$", RegexOptions.NonBacktracking)]
 	private static partial Regex ServerThreadInfoRegex();
+	
+	private static readonly ImmutableHashSet<string> AutomaticSavingDisabledMessages = ImmutableHashSet.Create(
+		"Automatic saving is now disabled",
+		"Turned off world auto-saving",
+		"CONSOLE: Disabling level saving.."
+	);
+	
+	private static readonly ImmutableHashSet<string> SavedTheGameMessages = ImmutableHashSet.Create(
+		"Saved the game",
+		"Saved the world",
+		"CONSOLE: Save complete."
+	);
+	
+	private static readonly ImmutableHashSet<string> AutomaticSavingEnabledMessages = ImmutableHashSet.Create(
+		"Automatic saving is now enabled",
+		"Turned on world auto-saving",
+		"CONSOLE: Enabling level saving.."
+	);
 
 	private readonly ILogger logger;
 	private readonly InstanceProcess process;
@@ -32,18 +51,17 @@ sealed partial class BackupServerCommandDispatcher : IDisposable {
 
 	public async Task DisableAutomaticSaving() {
 		await process.SendCommand(MinecraftCommand.SaveOff, cancellationToken);
-		await automaticSavingDisabled.Task.WaitAsync(cancellationToken);
+		await automaticSavingDisabled.Task.WaitAsync(TimeSpan.FromSeconds(30), cancellationToken);
 	}
 
 	public async Task SaveAllChunks() {
-		// TODO Try if not flushing and waiting a few seconds before flushing reduces lag.
 		await process.SendCommand(MinecraftCommand.SaveAll(flush: true), cancellationToken);
-		await savedTheGame.Task.WaitAsync(cancellationToken);
+		await savedTheGame.Task.WaitAsync(TimeSpan.FromMinutes(1), cancellationToken);
 	}
 
 	public async Task EnableAutomaticSaving() {
 		await process.SendCommand(MinecraftCommand.SaveOn, cancellationToken);
-		await automaticSavingEnabled.Task.WaitAsync(cancellationToken);
+		await automaticSavingEnabled.Task.WaitAsync(TimeSpan.FromMinutes(1), cancellationToken);
 	}
 
 	private void OnOutput(object? sender, string? line) {
@@ -59,19 +77,19 @@ sealed partial class BackupServerCommandDispatcher : IDisposable {
 		string info = match.Groups[1].Value;
 
 		if (!automaticSavingDisabled.Task.IsCompleted) {
-			if (info == "Automatic saving is now disabled") {
+			if (AutomaticSavingDisabledMessages.Contains(info)) {
 				logger.Debug("Detected that automatic saving is disabled.");
 				automaticSavingDisabled.SetResult();
 			}
 		}
 		else if (!savedTheGame.Task.IsCompleted) {
-			if (info == "Saved the game") {
+			if (SavedTheGameMessages.Contains(info)) {
 				logger.Debug("Detected that the game is saved.");
 				savedTheGame.SetResult();
 			}
 		}
 		else if (!automaticSavingEnabled.Task.IsCompleted) {
-			if (info == "Automatic saving is now enabled") {
+			if (AutomaticSavingEnabledMessages.Contains(info)) {
 				logger.Debug("Detected that automatic saving is enabled.");
 				automaticSavingEnabled.SetResult();
 			}

Agent/Phantom.Agent.Services/Instances/IInstanceContext.cs

@@ -1,25 +0,0 @@
-using Phantom.Agent.Services.Instances.Procedures;
-using Phantom.Agent.Services.Instances.States;
-using Phantom.Common.Data.Instance;
-using Serilog;
-
-namespace Phantom.Agent.Services.Instances;
-
-interface IInstanceContext {
-	string ShortName { get; }
-	ILogger Logger { get; }
-	
-	InstanceServices Services { get; }
-	IInstanceState CurrentState { get; }
-
-	void SetStatus(IInstanceStatus newStatus);
-	void ReportEvent(IInstanceEvent instanceEvent);
-	void EnqueueProcedure(IInstanceProcedure procedure, bool immediate = false);
-}
-
-static class InstanceContextExtensions {
-	public static void SetLaunchFailedStatusAndReportEvent(this IInstanceContext context, InstanceLaunchFailReason reason) {
-		context.SetStatus(InstanceStatus.Failed(reason));
-		context.ReportEvent(new InstanceLaunchFailedEvent(reason));
-	}
-}

Agent/Phantom.Agent.Services/Instances/Instance.cs

@@ -1,187 +1,5 @@
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Services.Instances.Procedures;
-using Phantom.Agent.Services.Instances.States;
-using Phantom.Common.Data.Instance;
-using Phantom.Common.Data.Minecraft;
-using Phantom.Common.Data.Replies;
-using Phantom.Common.Logging;
-using Phantom.Common.Messages.Agent.ToController;
-using Serilog;
+using Phantom.Common.Data.Instance;
 
 namespace Phantom.Agent.Services.Instances;
 
-sealed class Instance : IAsyncDisposable {
-	private InstanceServices Services { get; }
-	
-	public InstanceConfiguration Configuration { get; private set; }
-	private IServerLauncher Launcher { get; set; }
-	private readonly SemaphoreSlim configurationSemaphore = new (1, 1);
-
-	private readonly string shortName;
-	private readonly ILogger logger;
-
-	private IInstanceStatus currentStatus;
-	private int statusUpdateCounter;
-	
-	private IInstanceState currentState;
-	public bool IsRunning => currentState is not InstanceNotRunningState;
-	
-	public event EventHandler? IsRunningChanged;
-	
-	private readonly InstanceProcedureManager procedureManager;
-
-	public Instance(string shortName, InstanceServices services, InstanceConfiguration configuration, IServerLauncher launcher) {
-		this.shortName = shortName;
-		this.logger = PhantomLogger.Create<Instance>(shortName);
-
-		this.Services = services;
-		this.Configuration = configuration;
-		this.Launcher = launcher;
-		
-		this.currentState = new InstanceNotRunningState();
-		this.currentStatus = InstanceStatus.NotRunning;
-		
-		this.procedureManager = new InstanceProcedureManager(this, new Context(this), services.TaskManager);
-	}
-
-	private void TryUpdateStatus(string taskName, Func<Task> getUpdateTask) {
-		int myStatusUpdateCounter = Interlocked.Increment(ref statusUpdateCounter);
-		
-		Services.TaskManager.Run(taskName, async () => {
-			if (myStatusUpdateCounter == statusUpdateCounter) {
-				await getUpdateTask();
-			}
-		});
-	}
-
-	public void ReportLastStatus() {
-		TryUpdateStatus("Report last status of instance " + shortName, async () => {
-			await Services.ControllerConnection.Send(new ReportInstanceStatusMessage(Configuration.InstanceGuid, currentStatus));
-		});
-	}
-
-	private void ReportAndSetStatus(IInstanceStatus status) {
-		TryUpdateStatus("Report status of instance " + shortName + " as " + status.GetType().Name, async () => {
-			if (status != currentStatus) {
-				currentStatus = status;
-				await Services.ControllerConnection.Send(new ReportInstanceStatusMessage(Configuration.InstanceGuid, status));
-			}
-		});
-	}
-
-	private void ReportEvent(IInstanceEvent instanceEvent) {
-		var message = new ReportInstanceEventMessage(Guid.NewGuid(), DateTime.UtcNow, Configuration.InstanceGuid, instanceEvent);
-		Services.TaskManager.Run("Report event for instance " + shortName, async () => await Services.ControllerConnection.Send(message));
-	}
-	
-	internal void TransitionState(IInstanceState newState) {
-		if (currentState == newState) {
-			return;
-		}
-
-		if (currentState is IDisposable disposable) {
-			disposable.Dispose();
-		}
-
-		logger.Debug("Transitioning instance state to: {NewState}", newState.GetType().Name);
-		
-		var wasRunning = IsRunning;
-		currentState = newState;
-		currentState.Initialize();
-
-		if (IsRunning != wasRunning) {
-			IsRunningChanged?.Invoke(this, EventArgs.Empty);
-		}
-	}
-
-	public async Task Reconfigure(InstanceConfiguration configuration, IServerLauncher launcher, CancellationToken cancellationToken) {
-		await configurationSemaphore.WaitAsync(cancellationToken);
-		try {
-			Configuration = configuration;
-			Launcher = launcher;
-		} finally {
-			configurationSemaphore.Release();
-		}
-	}
-
-	public async Task<LaunchInstanceResult> Launch(CancellationToken cancellationToken) {
-		if (IsRunning) {
-			return LaunchInstanceResult.InstanceAlreadyRunning;
-		}
-
-		if (await procedureManager.GetCurrentProcedure(cancellationToken) is LaunchInstanceProcedure) {
-			return LaunchInstanceResult.InstanceAlreadyLaunching;
-		}
-		
-		LaunchInstanceProcedure procedure;
-		
-		await configurationSemaphore.WaitAsync(cancellationToken);
-		try {
-			procedure = new LaunchInstanceProcedure(Configuration, Launcher);
-		} finally {
-			configurationSemaphore.Release();
-		}
-		
-		ReportAndSetStatus(InstanceStatus.Launching);
-		await procedureManager.Enqueue(procedure);
-		return LaunchInstanceResult.LaunchInitiated;
-	}
-
-	public async Task<StopInstanceResult> Stop(MinecraftStopStrategy stopStrategy, CancellationToken cancellationToken) {
-		if (!IsRunning) {
-			return StopInstanceResult.InstanceAlreadyStopped;
-		}
-		
-		if (await procedureManager.GetCurrentProcedure(cancellationToken) is StopInstanceProcedure) {
-			return StopInstanceResult.InstanceAlreadyStopping;
-		}
-		
-		ReportAndSetStatus(InstanceStatus.Stopping);
-		await procedureManager.Enqueue(new StopInstanceProcedure(stopStrategy));
-		return StopInstanceResult.StopInitiated;
-	}
-
-	public async Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		return await currentState.SendCommand(command, cancellationToken);
-	}
-
-	public async ValueTask DisposeAsync() {
-		await procedureManager.DisposeAsync();
-
-		while (currentState is not InstanceNotRunningState) {
-			await Task.Delay(TimeSpan.FromMilliseconds(250), CancellationToken.None);
-		}
-
-		if (currentState is IDisposable disposable) {
-			disposable.Dispose();
-		}
-		
-		configurationSemaphore.Dispose();
-	}
-
-	private sealed class Context : IInstanceContext {
-		public string ShortName => instance.shortName;
-		public ILogger Logger => instance.logger;
-		
-		public InstanceServices Services => instance.Services;
-		public IInstanceState CurrentState => instance.currentState;
-
-		private readonly Instance instance;
-		
-		public Context(Instance instance) {
-			this.instance = instance;
-		}
-
-		public void SetStatus(IInstanceStatus newStatus) {
-			instance.ReportAndSetStatus(newStatus);
-		}
-
-		public void ReportEvent(IInstanceEvent instanceEvent) {
-			instance.ReportEvent(instanceEvent);
-		}
-
-		public void EnqueueProcedure(IInstanceProcedure procedure, bool immediate) {
-			Services.TaskManager.Run("Enqueue procedure for instance " + instance.shortName, () => instance.procedureManager.Enqueue(procedure, immediate));
-		}
-	}
-}
+sealed record Instance(Guid InstanceGuid, IInstanceStatus Status);

Agent/Phantom.Agent.Services/Instances/InstanceActor.cs

@@ -0,0 +1,161 @@
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Services.Backups;
+using Phantom.Agent.Services.Instances.State;
+using Phantom.Common.Data.Backups;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Minecraft;
+using Phantom.Common.Data.Replies;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Actor.Mailbox;
+using Phantom.Utils.Logging;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
+	public readonly record struct Init(AgentState AgentState, Guid InstanceGuid, string ShortName, InstanceServices InstanceServices, InstanceTicketManager InstanceTicketManager, CancellationToken ShutdownCancellationToken);
+
+	public static Props<ICommand> Factory(Init init) {
+		return Props<ICommand>.Create(() => new InstanceActor(init), new ActorConfiguration { SupervisorStrategy = SupervisorStrategies.Resume, MailboxType = UnboundedJumpAheadMailbox.Name });
+	}
+
+	private readonly AgentState agentState;
+	private readonly CancellationToken shutdownCancellationToken;
+	
+	private readonly Guid instanceGuid;
+	private readonly InstanceServices instanceServices;
+	private readonly InstanceTicketManager instanceTicketManager;
+	private readonly InstanceContext context;
+	
+	private readonly CancellationTokenSource actorCancellationTokenSource = new ();
+
+	private IInstanceStatus currentStatus = InstanceStatus.NotRunning;
+	private InstanceRunningState? runningState = null;
+
+	private InstanceActor(Init init) {
+		this.agentState = init.AgentState;
+		this.instanceGuid = init.InstanceGuid;
+		this.instanceServices = init.InstanceServices;
+		this.instanceTicketManager = init.InstanceTicketManager;
+		this.shutdownCancellationToken = init.ShutdownCancellationToken;
+		
+		var logger = PhantomLogger.Create<InstanceActor>(init.ShortName);
+		this.context = new InstanceContext(instanceGuid, init.ShortName, logger, instanceServices, SelfTyped, actorCancellationTokenSource.Token);
+
+		Receive<ReportInstanceStatusCommand>(ReportInstanceStatus);
+		ReceiveAsync<LaunchInstanceCommand>(LaunchInstance);
+		ReceiveAsync<StopInstanceCommand>(StopInstance);
+		ReceiveAsyncAndReply<SendCommandToInstanceCommand, SendCommandToInstanceResult>(SendCommandToInstance);
+		ReceiveAsyncAndReply<BackupInstanceCommand, BackupCreationResult>(BackupInstance);
+		Receive<HandleProcessEndedCommand>(HandleProcessEnded);
+		ReceiveAsync<ShutdownCommand>(Shutdown);
+	}
+
+	private void SetAndReportStatus(IInstanceStatus status) {
+		currentStatus = status;
+		ReportCurrentStatus();
+	}
+
+	private void ReportCurrentStatus() {
+		agentState.UpdateInstance(new Instance(instanceGuid, currentStatus));
+		instanceServices.ControllerConnection.Send(new ReportInstanceStatusMessage(instanceGuid, currentStatus));
+	}
+
+	private void TransitionState(InstanceRunningState? newState) {
+		if (runningState == newState) {
+			return;
+		}
+
+		runningState?.Dispose();
+		runningState = newState;
+		runningState?.Initialize();
+	}
+	
+	public interface ICommand {}
+
+	public sealed record ReportInstanceStatusCommand : ICommand;
+	
+	public sealed record LaunchInstanceCommand(InstanceConfiguration Configuration, IServerLauncher Launcher, InstanceTicketManager.Ticket Ticket, bool IsRestarting) : ICommand;
+	
+	public sealed record StopInstanceCommand(MinecraftStopStrategy StopStrategy) : ICommand;
+	
+	public sealed record SendCommandToInstanceCommand(string Command) : ICommand, ICanReply<SendCommandToInstanceResult>;
+	
+	public sealed record BackupInstanceCommand(BackupManager BackupManager) : ICommand, ICanReply<BackupCreationResult>;
+	
+	public sealed record HandleProcessEndedCommand(IInstanceStatus Status) : ICommand, IJumpAhead;
+	
+	public sealed record ShutdownCommand : ICommand;
+
+	private void ReportInstanceStatus(ReportInstanceStatusCommand command) {
+		ReportCurrentStatus();
+	}
+	
+	private async Task LaunchInstance(LaunchInstanceCommand command) {
+		if (command.IsRestarting || runningState is null) {
+			SetAndReportStatus(command.IsRestarting ? InstanceStatus.Restarting : InstanceStatus.Launching);
+			
+			var newState = await InstanceLaunchProcedure.Run(context, command.Configuration, command.Launcher, instanceTicketManager, command.Ticket, SetAndReportStatus, shutdownCancellationToken);
+			if (newState is null) {
+				instanceTicketManager.Release(command.Ticket);
+			}
+			
+			TransitionState(newState);
+		}
+	}
+
+	private async Task StopInstance(StopInstanceCommand command) {
+		if (runningState is null) {
+			return;
+		}
+
+		IInstanceStatus oldStatus = currentStatus;
+		SetAndReportStatus(InstanceStatus.Stopping);
+		
+		if (await InstanceStopProcedure.Run(context, command.StopStrategy, runningState, SetAndReportStatus, shutdownCancellationToken)) {
+			instanceTicketManager.Release(runningState.Ticket);
+			TransitionState(null);
+		}
+		else {
+			SetAndReportStatus(oldStatus);
+		}
+	}
+
+	private async Task<SendCommandToInstanceResult> SendCommandToInstance(SendCommandToInstanceCommand command) {
+		if (runningState is null) {
+			return SendCommandToInstanceResult.InstanceNotRunning;
+		}
+		else {
+			return await runningState.SendCommand(command.Command, shutdownCancellationToken);
+		}
+	}
+	
+	private async Task<BackupCreationResult> BackupInstance(BackupInstanceCommand command) {
+		if (runningState is null || runningState.Process.HasEnded) {
+			return new BackupCreationResult(BackupCreationResultKind.InstanceNotRunning);
+		}
+		else {
+			SetAndReportStatus(InstanceStatus.BackingUp);
+			try {
+				return await command.BackupManager.CreateBackup(context.ShortName, runningState.Process, shutdownCancellationToken);
+			} finally {
+				SetAndReportStatus(InstanceStatus.Running);
+			}
+		}
+	}
+
+	private void HandleProcessEnded(HandleProcessEndedCommand command) {
+		if (runningState is { Process.HasEnded: true }) {
+			SetAndReportStatus(command.Status);
+			context.ReportEvent(InstanceEvent.Stopped);
+			instanceTicketManager.Release(runningState.Ticket);
+			TransitionState(null);
+		}
+	}
+
+	private async Task Shutdown(ShutdownCommand command) {
+		await StopInstance(new StopInstanceCommand(MinecraftStopStrategy.Instant));
+		await actorCancellationTokenSource.CancelAsync();
+		Context.Stop(Self);
+	}
+}

Agent/Phantom.Agent.Services/Instances/InstanceContext.cs

@@ -0,0 +1,12 @@
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Actor;
+using Serilog;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed record InstanceContext(Guid InstanceGuid, string ShortName, ILogger Logger, InstanceServices Services, ActorRef<InstanceActor.ICommand> Actor, CancellationToken ActorCancellationToken) {
+	public void ReportEvent(IInstanceEvent instanceEvent) {
+		Services.ControllerConnection.Send(new ReportInstanceEventMessage(Guid.NewGuid(), DateTime.UtcNow, InstanceGuid, instanceEvent));
+	}
+}

Agent/Phantom.Agent.Services/Instances/InstanceManagerActor.cs

@@ -0,0 +1,209 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Java;
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Minecraft.Launcher.Types;
+using Phantom.Agent.Minecraft.Properties;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Rpc;
+using Phantom.Agent.Services.Backups;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Minecraft;
+using Phantom.Common.Data.Replies;
+using Phantom.Utils.Actor;
+using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
+using Serilog;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed class InstanceManagerActor : ReceiveActor<InstanceManagerActor.ICommand> {
+	private static readonly ILogger Logger = PhantomLogger.Create<InstanceManagerActor>();
+
+	public readonly record struct Init(ControllerConnection ControllerConnection, AgentFolders AgentFolders, AgentState AgentState, JavaRuntimeRepository JavaRuntimeRepository, InstanceTicketManager InstanceTicketManager, BackupManager BackupManager);
+
+	public static Props<ICommand> Factory(Init init) {
+		return Props<ICommand>.Create(() => new InstanceManagerActor(init), new ActorConfiguration { SupervisorStrategy = SupervisorStrategies.Resume });
+	}
+	
+	private readonly AgentState agentState;
+	private readonly string basePath;
+
+	private readonly InstanceServices instanceServices;
+	private readonly InstanceTicketManager instanceTicketManager;
+	private readonly Dictionary<Guid, InstanceInfo> instances = new ();
+
+	private readonly CancellationTokenSource shutdownCancellationTokenSource = new ();
+	private readonly CancellationToken shutdownCancellationToken;
+
+	private uint instanceLoggerSequenceId = 0;
+
+	private InstanceManagerActor(Init init) {
+		this.agentState = init.AgentState;
+		this.basePath = init.AgentFolders.InstancesFolderPath;
+		this.instanceTicketManager = init.InstanceTicketManager;
+		this.shutdownCancellationToken = shutdownCancellationTokenSource.Token;
+
+		var minecraftServerExecutables = new MinecraftServerExecutables(init.AgentFolders.ServerExecutableFolderPath);
+		var launchServices = new LaunchServices(minecraftServerExecutables, init.JavaRuntimeRepository);
+
+		this.instanceServices = new InstanceServices(init.ControllerConnection, init.BackupManager, launchServices);
+		
+		ReceiveAndReply<ConfigureInstanceCommand, Result<ConfigureInstanceResult, InstanceActionFailure>>(ConfigureInstance);
+		ReceiveAndReply<LaunchInstanceCommand, Result<LaunchInstanceResult, InstanceActionFailure>>(LaunchInstance);
+		ReceiveAndReply<StopInstanceCommand, Result<StopInstanceResult, InstanceActionFailure>>(StopInstance);
+		ReceiveAsyncAndReply<SendCommandToInstanceCommand, Result<SendCommandToInstanceResult, InstanceActionFailure>>(SendCommandToInstance);
+		ReceiveAsync<ShutdownCommand>(Shutdown);
+	}
+
+	private string GetInstanceLoggerName(Guid guid) {
+		var prefix = guid.ToString();
+		return prefix[..prefix.IndexOf('-')] + "/" + Interlocked.Increment(ref instanceLoggerSequenceId);
+	}
+
+	private sealed record InstanceInfo(ActorRef<InstanceActor.ICommand> Actor, InstanceConfiguration Configuration, IServerLauncher Launcher);
+	
+	public interface ICommand {}
+	
+	public sealed record ConfigureInstanceCommand(Guid InstanceGuid, InstanceConfiguration Configuration, InstanceLaunchProperties LaunchProperties, bool LaunchNow, bool AlwaysReportStatus) : ICommand, ICanReply<Result<ConfigureInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record LaunchInstanceCommand(Guid InstanceGuid) : ICommand, ICanReply<Result<LaunchInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record StopInstanceCommand(Guid InstanceGuid, MinecraftStopStrategy StopStrategy) : ICommand, ICanReply<Result<StopInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record SendCommandToInstanceCommand(Guid InstanceGuid, string Command) : ICommand, ICanReply<Result<SendCommandToInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record ShutdownCommand : ICommand;
+
+	private Result<ConfigureInstanceResult, InstanceActionFailure> ConfigureInstance(ConfigureInstanceCommand command) {
+		var instanceGuid = command.InstanceGuid;
+		var configuration = command.Configuration;
+
+		var instanceFolder = Path.Combine(basePath, instanceGuid.ToString());
+		Directories.Create(instanceFolder, Chmod.URWX_GRX);
+
+		var heapMegabytes = configuration.MemoryAllocation.InMegabytes;
+		var jvmProperties = new JvmProperties(
+			InitialHeapMegabytes: heapMegabytes / 2,
+			MaximumHeapMegabytes: heapMegabytes
+		);
+
+		var properties = new InstanceProperties(
+			instanceGuid,
+			configuration.JavaRuntimeGuid,
+			jvmProperties,
+			configuration.JvmArguments,
+			instanceFolder,
+			configuration.MinecraftVersion,
+			new ServerProperties(configuration.ServerPort, configuration.RconPort),
+			command.LaunchProperties
+		);
+
+		IServerLauncher launcher = configuration.MinecraftServerKind switch {
+			MinecraftServerKind.Vanilla => new VanillaLauncher(properties),
+			MinecraftServerKind.Fabric  => new FabricLauncher(properties),
+			MinecraftServerKind.Forge   => new ForgeLauncher(properties),
+			_                           => InvalidLauncher.Instance
+		};
+
+		if (instances.TryGetValue(instanceGuid, out var instance)) {
+			instances[instanceGuid] = instance with {
+				Configuration = configuration,
+				Launcher = launcher
+			};
+				
+			Logger.Information("Reconfigured instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, instanceGuid);
+
+			if (command.AlwaysReportStatus) {
+				instance.Actor.Tell(new InstanceActor.ReportInstanceStatusCommand());
+			}
+		}
+		else {
+			var instanceInit = new InstanceActor.Init(agentState, instanceGuid, GetInstanceLoggerName(instanceGuid), instanceServices, instanceTicketManager, shutdownCancellationToken);
+			instances[instanceGuid] = instance = new InstanceInfo(Context.ActorOf(InstanceActor.Factory(instanceInit), "Instance-" + instanceGuid), configuration, launcher);
+				
+			Logger.Information("Created instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, instanceGuid);
+
+			instance.Actor.Tell(new InstanceActor.ReportInstanceStatusCommand());
+		}
+
+		if (command.LaunchNow) {
+			LaunchInstance(new LaunchInstanceCommand(instanceGuid));
+		}
+
+		return ConfigureInstanceResult.Success;
+	}
+
+	private Result<LaunchInstanceResult, InstanceActionFailure> LaunchInstance(LaunchInstanceCommand command) {
+		var instanceGuid = command.InstanceGuid;
+		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
+			return InstanceActionFailure.InstanceDoesNotExist;
+		}
+		
+		var ticket = instanceTicketManager.Reserve(instanceInfo.Configuration);
+		if (!ticket) {
+			return ticket.Error;
+		}
+
+		if (agentState.InstancesByGuid.TryGetValue(instanceGuid, out var instance)) {
+			var status = instance.Status;
+			if (status.IsRunning()) {
+				return LaunchInstanceResult.InstanceAlreadyRunning;
+			}
+			else if (status.IsLaunching()) {
+				return LaunchInstanceResult.InstanceAlreadyLaunching;
+			}
+		}
+		
+		instanceInfo.Actor.Tell(new InstanceActor.LaunchInstanceCommand(instanceInfo.Configuration, instanceInfo.Launcher, ticket.Value, IsRestarting: false));
+		return LaunchInstanceResult.LaunchInitiated;
+	}
+
+	private Result<StopInstanceResult, InstanceActionFailure> StopInstance(StopInstanceCommand command) {
+		var instanceGuid = command.InstanceGuid;
+		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
+			return InstanceActionFailure.InstanceDoesNotExist;
+		}
+        
+		if (agentState.InstancesByGuid.TryGetValue(instanceGuid, out var instance)) {
+			var status = instance.Status;
+			if (status.IsStopping()) {
+				return StopInstanceResult.InstanceAlreadyStopping;
+			}
+			else if (!status.CanStop()) {
+				return StopInstanceResult.InstanceAlreadyStopped;
+			}
+		}
+			
+		instanceInfo.Actor.Tell(new InstanceActor.StopInstanceCommand(command.StopStrategy));
+		return StopInstanceResult.StopInitiated;
+	}
+
+	private async Task<Result<SendCommandToInstanceResult, InstanceActionFailure>> SendCommandToInstance(SendCommandToInstanceCommand command) {
+		var instanceGuid = command.InstanceGuid;
+		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
+			return InstanceActionFailure.InstanceDoesNotExist;
+		}
+
+		try {
+			return await instanceInfo.Actor.Request(new InstanceActor.SendCommandToInstanceCommand(command.Command), shutdownCancellationToken);
+		} catch (OperationCanceledException) {
+			return InstanceActionFailure.AgentShuttingDown;
+		}
+	}
+
+	private async Task Shutdown(ShutdownCommand command) {
+		Logger.Information("Stopping all instances...");
+		
+		await shutdownCancellationTokenSource.CancelAsync();
+		
+		await Task.WhenAll(instances.Values.Select(static instance => instance.Actor.Stop(new InstanceActor.ShutdownCommand())));
+		instances.Clear();
+		
+		shutdownCancellationTokenSource.Dispose();
+		
+		Logger.Information("All instances stopped.");
+		
+		Context.Stop(Self);
+	}
+}

Agent/Phantom.Agent.Services/Instances/InstanceProcedureManager.cs

@@ -1,85 +0,0 @@
-using Phantom.Agent.Services.Instances.Procedures;
-using Phantom.Common.Data.Minecraft;
-using Phantom.Utils.Tasks;
-using Phantom.Utils.Threading;
-
-namespace Phantom.Agent.Services.Instances;
-
-sealed class InstanceProcedureManager : IAsyncDisposable {
-	private readonly record struct CurrentProcedure(IInstanceProcedure Procedure, CancellationTokenSource CancellationTokenSource);
-
-	private readonly ThreadSafeStructRef<CurrentProcedure> currentProcedure = new ();
-	private readonly ThreadSafeLinkedList<IInstanceProcedure> procedureQueue = new ();
-	private readonly AutoResetEvent procedureQueueReady = new (false);
-	private readonly ManualResetEventSlim procedureQueueFinished = new (false);
-
-	private readonly Instance instance;
-	private readonly IInstanceContext context;
-	private readonly CancellationTokenSource shutdownCancellationTokenSource = new ();
-
-	public InstanceProcedureManager(Instance instance, IInstanceContext context, TaskManager taskManager) {
-		this.instance = instance;
-		this.context = context;
-		taskManager.Run("Procedure manager for instance " + context.ShortName, Run);
-	}
-
-	public async Task Enqueue(IInstanceProcedure procedure, bool immediate = false) {
-		await procedureQueue.Add(procedure, toFront: immediate, shutdownCancellationTokenSource.Token);
-		procedureQueueReady.Set();
-	}
-
-	public async Task<IInstanceProcedure?> GetCurrentProcedure(CancellationToken cancellationToken) {
-		return (await currentProcedure.Get(cancellationToken))?.Procedure;
-	}
-
-	private async Task Run() {
-		try {
-			var shutdownCancellationToken = shutdownCancellationTokenSource.Token;
-			while (true) {
-				await procedureQueueReady.WaitOneAsync(shutdownCancellationToken);
-				while (await procedureQueue.TryTakeFromFront(shutdownCancellationToken) is {} nextProcedure) {
-					using var procedureCancellationTokenSource = new CancellationTokenSource();
-					await currentProcedure.Set(new CurrentProcedure(nextProcedure, procedureCancellationTokenSource), shutdownCancellationToken);
-					await RunProcedure(nextProcedure, procedureCancellationTokenSource.Token);
-					await currentProcedure.Set(null, shutdownCancellationToken);
-				}
-			}
-		} catch (OperationCanceledException) {
-			// Ignore.
-		}
-
-		await RunProcedure(new StopInstanceProcedure(MinecraftStopStrategy.Instant), CancellationToken.None);
-		procedureQueueFinished.Set();
-	}
-
-	private async Task RunProcedure(IInstanceProcedure procedure, CancellationToken cancellationToken) {
-		var procedureName = procedure.GetType().Name;
-
-		context.Logger.Debug("Started procedure: {Procedure}", procedureName);
-		try {
-			var newState = await procedure.Run(context, cancellationToken);
-			context.Logger.Debug("Finished procedure: {Procedure}", procedureName);
-
-			if (newState != null) {
-				instance.TransitionState(newState);
-			}
-		} catch (OperationCanceledException) {
-			context.Logger.Debug("Cancelled procedure: {Procedure}", procedureName);
-		} catch (Exception e) {
-			context.Logger.Error(e, "Caught exception while running procedure: {Procedure}", procedureName);
-		}
-	}
-
-	public async ValueTask DisposeAsync() {
-		shutdownCancellationTokenSource.Cancel();
-
-		(await currentProcedure.Get(CancellationToken.None))?.CancellationTokenSource.Cancel();
-		await procedureQueueFinished.WaitHandle.WaitOneAsync();
-
-		currentProcedure.Dispose();
-		procedureQueue.Dispose();
-		procedureQueueReady.Dispose();
-		procedureQueueFinished.Dispose();
-		shutdownCancellationTokenSource.Dispose();
-	}
-}

Agent/Phantom.Agent.Services/Instances/InstanceServices.cs

@@ -1,8 +1,7 @@
 using Phantom.Agent.Minecraft.Launcher;
 using Phantom.Agent.Rpc;
 using Phantom.Agent.Services.Backups;
-using Phantom.Utils.Tasks;
 
 namespace Phantom.Agent.Services.Instances;
 
-sealed record InstanceServices(ControllerConnection ControllerConnection, TaskManager TaskManager, PortManager PortManager, BackupManager BackupManager, LaunchServices LaunchServices);
+sealed record InstanceServices(ControllerConnection ControllerConnection, BackupManager BackupManager, LaunchServices LaunchServices);

Agent/Phantom.Agent.Services/Instances/InstanceSessionManager.cs

@@ -1,198 +0,0 @@
-using System.Collections.Immutable;
-using System.Diagnostics.CodeAnalysis;
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Agent.Minecraft.Java;
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Minecraft.Launcher.Types;
-using Phantom.Agent.Minecraft.Properties;
-using Phantom.Agent.Minecraft.Server;
-using Phantom.Agent.Rpc;
-using Phantom.Agent.Services.Backups;
-using Phantom.Common.Data;
-using Phantom.Common.Data.Agent;
-using Phantom.Common.Data.Instance;
-using Phantom.Common.Data.Minecraft;
-using Phantom.Common.Data.Replies;
-using Phantom.Common.Logging;
-using Phantom.Common.Messages.Agent.ToController;
-using Phantom.Utils.IO;
-using Phantom.Utils.Tasks;
-using Serilog;
-
-namespace Phantom.Agent.Services.Instances;
-
-sealed class InstanceSessionManager : IAsyncDisposable {
-	private static readonly ILogger Logger = PhantomLogger.Create<InstanceSessionManager>();
-
-	private readonly ControllerConnection controllerConnection;
-	private readonly AgentInfo agentInfo;
-	private readonly string basePath;
-
-	private readonly InstanceServices instanceServices;
-	private readonly Dictionary<Guid, Instance> instances = new ();
-
-	private readonly CancellationTokenSource shutdownCancellationTokenSource = new ();
-	private readonly CancellationToken shutdownCancellationToken;
-	private readonly SemaphoreSlim semaphore = new (1, 1);
-
-	private uint instanceLoggerSequenceId = 0;
-
-	public InstanceSessionManager(ControllerConnection controllerConnection, AgentInfo agentInfo, AgentFolders agentFolders, JavaRuntimeRepository javaRuntimeRepository, TaskManager taskManager, BackupManager backupManager) {
-		this.controllerConnection = controllerConnection;
-		this.agentInfo = agentInfo;
-		this.basePath = agentFolders.InstancesFolderPath;
-		this.shutdownCancellationToken = shutdownCancellationTokenSource.Token;
-
-		var minecraftServerExecutables = new MinecraftServerExecutables(agentFolders.ServerExecutableFolderPath);
-		var launchServices = new LaunchServices(minecraftServerExecutables, javaRuntimeRepository);
-		var portManager = new PortManager(agentInfo.AllowedServerPorts, agentInfo.AllowedRconPorts);
-
-		this.instanceServices = new InstanceServices(controllerConnection, taskManager, portManager, backupManager, launchServices);
-	}
-
-	private async Task<InstanceActionResult<T>> AcquireSemaphoreAndRun<T>(Func<Task<InstanceActionResult<T>>> func) {
-		try {
-			await semaphore.WaitAsync(shutdownCancellationToken);
-			try {
-				return await func();
-			} finally {
-				semaphore.Release();
-			}
-		} catch (OperationCanceledException) {
-			return InstanceActionResult.General<T>(InstanceActionGeneralResult.AgentShuttingDown);
-		}
-	}
-
-	[SuppressMessage("ReSharper", "ConvertIfStatementToReturnStatement")]
-	private Task<InstanceActionResult<T>> AcquireSemaphoreAndRunWithInstance<T>(Guid instanceGuid, Func<Instance, Task<T>> func) {
-		return AcquireSemaphoreAndRun(async () => {
-			if (instances.TryGetValue(instanceGuid, out var instance)) {
-				return InstanceActionResult.Concrete(await func(instance));
-			}
-			else {
-				return InstanceActionResult.General<T>(InstanceActionGeneralResult.InstanceDoesNotExist);
-			}
-		});
-	}
-
-	public async Task<InstanceActionResult<ConfigureInstanceResult>> Configure(InstanceConfiguration configuration, InstanceLaunchProperties launchProperties, bool launchNow, bool alwaysReportStatus) {
-		return await AcquireSemaphoreAndRun(async () => {
-			var instanceGuid = configuration.InstanceGuid;
-			var instanceFolder = Path.Combine(basePath, instanceGuid.ToString());
-			Directories.Create(instanceFolder, Chmod.URWX_GRX);
-
-			var heapMegabytes = configuration.MemoryAllocation.InMegabytes;
-			var jvmProperties = new JvmProperties(
-				InitialHeapMegabytes: heapMegabytes / 2,
-				MaximumHeapMegabytes: heapMegabytes
-			);
-
-			var properties = new InstanceProperties(
-				instanceGuid,
-				configuration.JavaRuntimeGuid,
-				jvmProperties,
-				configuration.JvmArguments,
-				instanceFolder,
-				configuration.MinecraftVersion,
-				new ServerProperties(configuration.ServerPort, configuration.RconPort),
-				launchProperties
-			);
-
-			IServerLauncher launcher = configuration.MinecraftServerKind switch {
-				MinecraftServerKind.Vanilla => new VanillaLauncher(properties),
-				MinecraftServerKind.Fabric  => new FabricLauncher(properties),
-				_                           => InvalidLauncher.Instance
-			};
-
-			if (instances.TryGetValue(instanceGuid, out var instance)) {
-				await instance.Reconfigure(configuration, launcher, shutdownCancellationToken);
-				Logger.Information("Reconfigured instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, configuration.InstanceGuid);
-
-				if (alwaysReportStatus) {
-					instance.ReportLastStatus();
-				}
-			}
-			else {
-				instances[instanceGuid] = instance = new Instance(GetInstanceLoggerName(instanceGuid), instanceServices, configuration, launcher);
-				Logger.Information("Created instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, configuration.InstanceGuid);
-
-				instance.ReportLastStatus();
-				instance.IsRunningChanged += OnInstanceIsRunningChanged;
-			}
-
-			if (launchNow) {
-				await LaunchInternal(instance);
-			}
-
-			return InstanceActionResult.Concrete(ConfigureInstanceResult.Success);
-		});
-	}
-
-	private string GetInstanceLoggerName(Guid guid) {
-		var prefix = guid.ToString();
-		return prefix[..prefix.IndexOf('-')] + "/" + Interlocked.Increment(ref instanceLoggerSequenceId);
-	}
-
-	private ImmutableArray<Instance> GetRunningInstancesInternal() {
-		return instances.Values.Where(static instance => instance.IsRunning).ToImmutableArray();
-	}
-
-	private void OnInstanceIsRunningChanged(object? sender, EventArgs e) {
-		instanceServices.TaskManager.Run("Handle instance running state changed event", RefreshAgentStatus);
-	}
-
-	public async Task RefreshAgentStatus() {
-		try {
-			await semaphore.WaitAsync(shutdownCancellationToken);
-			try {
-				var runningInstances = GetRunningInstancesInternal();
-				var runningInstanceCount = runningInstances.Length;
-				var runningInstanceMemory = runningInstances.Aggregate(RamAllocationUnits.Zero, static (total, instance) => total + instance.Configuration.MemoryAllocation);
-				await controllerConnection.Send(new ReportAgentStatusMessage(runningInstanceCount, runningInstanceMemory));
-			} finally {
-				semaphore.Release();
-			}
-		} catch (OperationCanceledException) {
-			// ignore
-		}
-	}
-
-	public Task<InstanceActionResult<LaunchInstanceResult>> Launch(Guid instanceGuid) {
-		return AcquireSemaphoreAndRunWithInstance(instanceGuid, LaunchInternal);
-	}
-
-	private async Task<LaunchInstanceResult> LaunchInternal(Instance instance) {
-		var runningInstances = GetRunningInstancesInternal();
-		if (runningInstances.Length + 1 > agentInfo.MaxInstances) {
-			return LaunchInstanceResult.InstanceLimitExceeded;
-		}
-
-		var availableMemory = agentInfo.MaxMemory - runningInstances.Aggregate(RamAllocationUnits.Zero, static (total, instance) => total + instance.Configuration.MemoryAllocation);
-		if (availableMemory < instance.Configuration.MemoryAllocation) {
-			return LaunchInstanceResult.MemoryLimitExceeded;
-		}
-
-		return await instance.Launch(shutdownCancellationToken);
-	}
-
-	public Task<InstanceActionResult<StopInstanceResult>> Stop(Guid instanceGuid, MinecraftStopStrategy stopStrategy) {
-		return AcquireSemaphoreAndRunWithInstance(instanceGuid, instance => instance.Stop(stopStrategy, shutdownCancellationToken));
-	}
-
-	public Task<InstanceActionResult<SendCommandToInstanceResult>> SendCommand(Guid instanceGuid, string command) {
-		return AcquireSemaphoreAndRunWithInstance(instanceGuid, async instance => await instance.SendCommand(command, shutdownCancellationToken) ? SendCommandToInstanceResult.Success : SendCommandToInstanceResult.UnknownError);
-	}
-
-	public async ValueTask DisposeAsync() {
-		Logger.Information("Stopping all instances...");
-		
-		shutdownCancellationTokenSource.Cancel();
-
-		await semaphore.WaitAsync(CancellationToken.None);
-		await Task.WhenAll(instances.Values.Select(static instance => instance.DisposeAsync().AsTask()));
-		instances.Clear();
-		
-		shutdownCancellationTokenSource.Dispose();
-		semaphore.Dispose();
-	}
-}

Agent/Phantom.Agent.Services/Instances/InstanceTicketManager.cs

@@ -0,0 +1,100 @@
+using Phantom.Agent.Rpc;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Agent;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Replies;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Tasks;
+using Serilog;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed class InstanceTicketManager {
+	private static readonly ILogger Logger = PhantomLogger.Create<InstanceTicketManager>();
+	
+	private readonly AgentInfo agentInfo;
+	private readonly ControllerConnection controllerConnection;
+	
+	private readonly HashSet<Guid> activeTicketGuids = new ();
+	private readonly HashSet<ushort> usedPorts = new ();
+	private RamAllocationUnits usedMemory = new ();
+
+	public InstanceTicketManager(AgentInfo agentInfo, ControllerConnection controllerConnection) {
+		this.agentInfo = agentInfo;
+		this.controllerConnection = controllerConnection;
+	}
+
+	public Result<Ticket, LaunchInstanceResult> Reserve(InstanceConfiguration configuration) {
+		var memoryAllocation = configuration.MemoryAllocation;
+		var serverPort = configuration.ServerPort;
+		var rconPort = configuration.RconPort;
+		
+		if (!agentInfo.AllowedServerPorts.Contains(serverPort)) {
+			return LaunchInstanceResult.ServerPortNotAllowed;
+		}
+
+		if (!agentInfo.AllowedRconPorts.Contains(rconPort)) {
+			return LaunchInstanceResult.RconPortNotAllowed;
+		}
+		
+		lock (this) {
+			if (activeTicketGuids.Count + 1 > agentInfo.MaxInstances) {
+				return LaunchInstanceResult.InstanceLimitExceeded;
+			}
+
+			if (usedMemory + memoryAllocation > agentInfo.MaxMemory) {
+				return LaunchInstanceResult.MemoryLimitExceeded;
+			}
+			
+			if (usedPorts.Contains(serverPort)) {
+				return LaunchInstanceResult.ServerPortAlreadyInUse;
+			}
+
+			if (usedPorts.Contains(rconPort)) {
+				return LaunchInstanceResult.RconPortAlreadyInUse;
+			}
+
+			var ticket = new Ticket(Guid.NewGuid(), memoryAllocation, serverPort, rconPort);
+			
+			activeTicketGuids.Add(ticket.TicketGuid);
+			usedMemory += memoryAllocation;
+			usedPorts.Add(serverPort);
+			usedPorts.Add(rconPort);
+			
+			RefreshAgentStatus();
+			Logger.Debug("Reserved ticket {TicketGuid} (server port {ServerPort}, rcon port {RconPort}, memory allocation {MemoryAllocation} MB).", ticket.TicketGuid, ticket.ServerPort, ticket.RconPort, ticket.MemoryAllocation.InMegabytes);
+
+			return ticket;
+		}
+	}
+
+	public bool IsValid(Ticket ticket) {
+		lock (this) {
+			return activeTicketGuids.Contains(ticket.TicketGuid);
+		}
+	}
+	
+	public void Release(Ticket ticket) {
+		lock (this) {
+			if (!activeTicketGuids.Remove(ticket.TicketGuid)) {
+				return;
+			}
+
+			usedMemory -= ticket.MemoryAllocation;
+			usedPorts.Remove(ticket.ServerPort);
+			usedPorts.Remove(ticket.RconPort);
+			
+			RefreshAgentStatus();
+			Logger.Debug("Released ticket {TicketGuid} (server port {ServerPort}, rcon port {RconPort}, memory allocation {MemoryAllocation} MB).", ticket.TicketGuid, ticket.ServerPort, ticket.RconPort, ticket.MemoryAllocation.InMegabytes);
+		}
+	}
+	
+	public void RefreshAgentStatus() {
+		lock (this) {
+			controllerConnection.Send(new ReportAgentStatusMessage(activeTicketGuids.Count, usedMemory));
+		}
+	}
+	
+	public sealed record Ticket(Guid TicketGuid, RamAllocationUnits MemoryAllocation, ushort ServerPort, ushort RconPort);
+}

Agent/Phantom.Agent.Services/Instances/PortManager.cs

@@ -1,58 +0,0 @@
-using Phantom.Common.Data;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances;
-
-sealed class PortManager {
-	private readonly AllowedPorts allowedServerPorts;
-	private readonly AllowedPorts allowedRconPorts;
-	private readonly HashSet<ushort> usedPorts = new ();
-
-	public PortManager(AllowedPorts allowedServerPorts, AllowedPorts allowedRconPorts) {
-		this.allowedServerPorts = allowedServerPorts;
-		this.allowedRconPorts = allowedRconPorts;
-	}
-
-	public Result Reserve(InstanceConfiguration configuration) {
-		var serverPort = configuration.ServerPort;
-		var rconPort = configuration.RconPort;
-		
-		if (!allowedServerPorts.Contains(serverPort)) {
-			return Result.ServerPortNotAllowed;
-		}
-
-		if (!allowedRconPorts.Contains(rconPort)) {
-			return Result.RconPortNotAllowed;
-		}
-		
-		lock (usedPorts) {
-			if (usedPorts.Contains(serverPort)) {
-				return Result.ServerPortAlreadyInUse;
-			}
-
-			if (usedPorts.Contains(rconPort)) {
-				return Result.RconPortAlreadyInUse;
-			}
-
-			usedPorts.Add(serverPort);
-			usedPorts.Add(rconPort);
-		}
-
-		return Result.Success;
-	}
-	
-	public void Release(InstanceConfiguration configuration) {
-		lock (usedPorts) {
-			usedPorts.Remove(configuration.ServerPort);
-			usedPorts.Remove(configuration.RconPort);
-		}
-	}
-
-	public enum Result {
-		Success,
-		ServerPortNotAllowed,
-		ServerPortAlreadyInUse,
-		RconPortNotAllowed,
-		RconPortAlreadyInUse
-	}
-}

Agent/Phantom.Agent.Services/Instances/Procedures/BackupInstanceProcedure.cs

@@ -1,29 +0,0 @@
-using Phantom.Agent.Services.Backups;
-using Phantom.Agent.Services.Instances.States;
-using Phantom.Common.Data.Backups;
-
-namespace Phantom.Agent.Services.Instances.Procedures;
-
-sealed record BackupInstanceProcedure(BackupManager BackupManager) : IInstanceProcedure {
-	private readonly TaskCompletionSource<BackupCreationResult> resultCompletionSource = new ();
-
-	public Task<BackupCreationResult> Result => resultCompletionSource.Task;
-
-	public async Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken) {
-		if (context.CurrentState is not InstanceRunningState runningState || runningState.Process.HasEnded) {
-			resultCompletionSource.SetResult(new BackupCreationResult(BackupCreationResultKind.InstanceNotRunning));
-			return null;
-		}
-
-		try {
-			var result = await BackupManager.CreateBackup(context.ShortName, runningState.Process, cancellationToken);
-			resultCompletionSource.SetResult(result);
-		} catch (OperationCanceledException) {
-			resultCompletionSource.SetCanceled(cancellationToken);
-		} catch (Exception e) {
-			resultCompletionSource.SetException(e);
-		}
-
-		return null;
-	}
-}

Agent/Phantom.Agent.Services/Instances/Procedures/IInstanceProcedure.cs

@@ -1,7 +0,0 @@
-using Phantom.Agent.Services.Instances.States;
-
-namespace Phantom.Agent.Services.Instances.Procedures;
-
-interface IInstanceProcedure {
-	Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken);
-}

Agent/Phantom.Agent.Services/Instances/Procedures/LaunchInstanceProcedure.cs

@@ -1,97 +0,0 @@
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Minecraft.Server;
-using Phantom.Agent.Services.Instances.States;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.Procedures;
-
-sealed record LaunchInstanceProcedure(InstanceConfiguration Configuration, IServerLauncher Launcher, bool IsRestarting = false) : IInstanceProcedure {
-	public async Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken) {
-		if (!IsRestarting && context.CurrentState is InstanceRunningState) {
-			return null;
-		}
-		
-		context.SetStatus(IsRestarting ? InstanceStatus.Restarting : InstanceStatus.Launching);
-
-		InstanceLaunchFailReason? failReason = context.Services.PortManager.Reserve(Configuration) switch {
-			PortManager.Result.ServerPortNotAllowed   => InstanceLaunchFailReason.ServerPortNotAllowed,
-			PortManager.Result.ServerPortAlreadyInUse => InstanceLaunchFailReason.ServerPortAlreadyInUse,
-			PortManager.Result.RconPortNotAllowed     => InstanceLaunchFailReason.RconPortNotAllowed,
-			PortManager.Result.RconPortAlreadyInUse   => InstanceLaunchFailReason.RconPortAlreadyInUse,
-			_                                         => null
-		};
-
-		if (failReason is {} reason) {
-			context.SetLaunchFailedStatusAndReportEvent(reason);
-			return new InstanceNotRunningState();
-		}
-		
-		context.Logger.Information("Session starting...");
-		try {
-			InstanceProcess process = await DoLaunch(context, cancellationToken);
-			return new InstanceRunningState(Configuration, Launcher, process, context);
-		} catch (OperationCanceledException) {
-			context.SetStatus(InstanceStatus.NotRunning);
-		} catch (LaunchFailureException e) {
-			context.Logger.Error(e.LogMessage);
-			context.SetLaunchFailedStatusAndReportEvent(e.Reason);
-		} catch (Exception e) {
-			context.Logger.Error(e, "Caught exception while launching instance.");
-			context.SetLaunchFailedStatusAndReportEvent(InstanceLaunchFailReason.UnknownError);
-		}
-		
-		context.Services.PortManager.Release(Configuration);
-		return new InstanceNotRunningState();
-	}
-
-	private async Task<InstanceProcess> DoLaunch(IInstanceContext context, CancellationToken cancellationToken) {
-		cancellationToken.ThrowIfCancellationRequested();
-
-		byte lastDownloadProgress = byte.MaxValue;
-
-		void OnDownloadProgress(object? sender, DownloadProgressEventArgs args) {
-			byte progress = (byte) Math.Min(args.DownloadedBytes * 100 / args.TotalBytes, 100);
-
-			if (lastDownloadProgress != progress) {
-				lastDownloadProgress = progress;
-				context.SetStatus(InstanceStatus.Downloading(progress));
-			}
-		}
-
-		var launchResult = await Launcher.Launch(context.Logger, context.Services.LaunchServices, OnDownloadProgress, cancellationToken);
-		if (launchResult is LaunchResult.InvalidJavaRuntime) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.JavaRuntimeNotFound, "Session failed to launch, invalid Java runtime.");
-		}
-		else if (launchResult is LaunchResult.CouldNotDownloadMinecraftServer) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotDownloadMinecraftServer, "Session failed to launch, could not download Minecraft server.");
-		}
-		else if (launchResult is LaunchResult.CouldNotPrepareMinecraftServerLauncher) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotPrepareMinecraftServerLauncher, "Session failed to launch, could not prepare Minecraft server launcher.");
-		}
-		else if (launchResult is LaunchResult.CouldNotConfigureMinecraftServer) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotConfigureMinecraftServer, "Session failed to launch, could not configure Minecraft server.");
-		}
-		else if (launchResult is LaunchResult.CouldNotStartMinecraftServer) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotStartMinecraftServer, "Session failed to launch, could not start Minecraft server.");
-		}
-
-		if (launchResult is not LaunchResult.Success launchSuccess) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.UnknownError, "Session failed to launch.");
-		}
-
-		context.SetStatus(InstanceStatus.Running);
-		context.ReportEvent(InstanceEvent.LaunchSucceded);
-		return launchSuccess.Process;
-	}
-
-	private sealed class LaunchFailureException : Exception {
-		public InstanceLaunchFailReason Reason { get; }
-		public string LogMessage { get; }
-
-		public LaunchFailureException(InstanceLaunchFailReason reason, string logMessage) {
-			this.Reason = reason;
-			this.LogMessage = logMessage;
-		}
-	}
-}

Agent/Phantom.Agent.Services/Instances/Procedures/SetInstanceToNotRunningStateProcedure.cs

@@ -1,17 +0,0 @@
-using Phantom.Agent.Services.Instances.States;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.Procedures;
-
-sealed record SetInstanceToNotRunningStateProcedure(IInstanceStatus Status) : IInstanceProcedure {
-	public Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken) {
-		if (context.CurrentState is InstanceRunningState { Process.HasEnded: true }) {
-			context.SetStatus(Status);
-			context.ReportEvent(InstanceEvent.Stopped);
-			return Task.FromResult<IInstanceState?>(new InstanceNotRunningState());
-		}
-		else {
-			return Task.FromResult<IInstanceState?>(null);
-		}
-	}
-}

Agent/Phantom.Agent.Services/Instances/State/InstanceLaunchProcedure.cs

@@ -0,0 +1,86 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Instance;
+
+namespace Phantom.Agent.Services.Instances.State;
+
+static class InstanceLaunchProcedure {
+	public static async Task<InstanceRunningState?> Run(InstanceContext context, InstanceConfiguration configuration, IServerLauncher launcher, InstanceTicketManager ticketManager, InstanceTicketManager.Ticket ticket, Action<IInstanceStatus> reportStatus, CancellationToken cancellationToken) {
+		context.Logger.Information("Session starting...");
+
+		Result<InstanceProcess, InstanceLaunchFailReason> result;
+
+		if (ticketManager.IsValid(ticket)) {
+			try {
+				result = await LaunchInstance(context, launcher, reportStatus, cancellationToken);
+			} catch (OperationCanceledException) {
+				reportStatus(InstanceStatus.NotRunning);
+				return null;
+			} catch (Exception e) {
+				context.Logger.Error(e, "Caught exception while launching instance.");
+				result = InstanceLaunchFailReason.UnknownError;
+			}
+		}
+		else {
+			context.Logger.Error("Attempted to launch instance with an invalid ticket!");
+			result = InstanceLaunchFailReason.UnknownError;
+		}
+
+		if (result) {
+			reportStatus(InstanceStatus.Running);
+			context.ReportEvent(InstanceEvent.LaunchSucceeded);
+			return new InstanceRunningState(context, configuration, launcher, ticket, result.Value, cancellationToken);
+		}
+		else {
+			reportStatus(InstanceStatus.Failed(result.Error));
+			context.ReportEvent(new InstanceLaunchFailedEvent(result.Error));
+			return null;
+		}
+	}
+
+	private static async Task<Result<InstanceProcess, InstanceLaunchFailReason>> LaunchInstance(InstanceContext context, IServerLauncher launcher, Action<IInstanceStatus> reportStatus, CancellationToken cancellationToken) {
+		cancellationToken.ThrowIfCancellationRequested();
+
+		byte lastDownloadProgress = byte.MaxValue;
+
+		void OnDownloadProgress(object? sender, DownloadProgressEventArgs args) {
+			byte progress = (byte) Math.Min(args.DownloadedBytes * 100 / args.TotalBytes, 100);
+
+			if (lastDownloadProgress != progress) {
+				lastDownloadProgress = progress;
+				reportStatus(InstanceStatus.Downloading(progress));
+			}
+		}
+
+		switch (await launcher.Launch(context.Logger, context.Services.LaunchServices, OnDownloadProgress, cancellationToken)) {
+			case LaunchResult.Success launchSuccess:
+				return launchSuccess.Process;
+
+			case LaunchResult.InvalidJavaRuntime:
+				context.Logger.Error("Session failed to launch, invalid Java runtime.");
+				return InstanceLaunchFailReason.JavaRuntimeNotFound;
+
+			case LaunchResult.CouldNotDownloadMinecraftServer:
+				context.Logger.Error("Session failed to launch, could not download Minecraft server.");
+				return InstanceLaunchFailReason.CouldNotDownloadMinecraftServer;
+
+			case LaunchResult.CouldNotPrepareMinecraftServerLauncher:
+				context.Logger.Error("Session failed to launch, could not prepare Minecraft server launcher.");
+				return InstanceLaunchFailReason.CouldNotPrepareMinecraftServerLauncher;
+
+			case LaunchResult.CouldNotConfigureMinecraftServer:
+				context.Logger.Error("Session failed to launch, could not configure Minecraft server.");
+				return InstanceLaunchFailReason.CouldNotConfigureMinecraftServer;
+
+			case LaunchResult.CouldNotStartMinecraftServer:
+				context.Logger.Error("Session failed to launch, could not start Minecraft server.");
+				return InstanceLaunchFailReason.CouldNotStartMinecraftServer;
+
+			default:
+				context.Logger.Error("Session failed to launch.");
+				return InstanceLaunchFailReason.UnknownError;
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/State/InstanceLogSender.cs

@@ -1,14 +1,14 @@
 using System.Collections.Immutable;
 using System.Threading.Channels;
 using Phantom.Agent.Rpc;
-using Phantom.Common.Logging;
 using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Logging;
 using Phantom.Utils.Tasks;
 
-namespace Phantom.Agent.Services.Instances;
+namespace Phantom.Agent.Services.Instances.State;
 
 sealed class InstanceLogSender : CancellableBackgroundTask {
-	private static readonly BoundedChannelOptions BufferOptions = new (capacity: 64) {
+	private static readonly BoundedChannelOptions BufferOptions = new (capacity: 100) {
 		SingleReader = true,
 		SingleWriter = true,
 		FullMode = BoundedChannelFullMode.DropNewest
@@ -22,7 +22,7 @@ sealed class InstanceLogSender : CancellableBackgroundTask {
 	
 	private int droppedLinesSinceLastSend;
 
-	public InstanceLogSender(ControllerConnection controllerConnection, TaskManager taskManager, Guid instanceGuid, string loggerName) : base(PhantomLogger.Create<InstanceLogSender>(loggerName), taskManager, "Instance log sender for " + loggerName) {
+	public InstanceLogSender(ControllerConnection controllerConnection, Guid instanceGuid, string loggerName) : base(PhantomLogger.Create<InstanceLogSender>(loggerName)) {
 		this.controllerConnection = controllerConnection;
 		this.instanceGuid = instanceGuid;
 		this.outputChannel = Channel.CreateBounded<string>(BufferOptions, OnLineDropped);
@@ -36,14 +36,14 @@ sealed class InstanceLogSender : CancellableBackgroundTask {
 		try {
 			while (await lineReader.WaitToReadAsync(CancellationToken)) {
 				await Task.Delay(SendDelay, CancellationToken);
-				await SendOutputToServer(ReadLinesFromChannel(lineReader, lineBuilder));
+				SendOutputToServer(ReadLinesFromChannel(lineReader, lineBuilder));
 			}
 		} catch (OperationCanceledException) {
 			// Ignore.
 		}
 
 		// Flush remaining lines.
-		await SendOutputToServer(ReadLinesFromChannel(lineReader, lineBuilder));
+		SendOutputToServer(ReadLinesFromChannel(lineReader, lineBuilder));
 	}
 
 	private ImmutableArray<string> ReadLinesFromChannel(ChannelReader<string> reader, ImmutableArray<string>.Builder builder) {
@@ -61,9 +61,9 @@ sealed class InstanceLogSender : CancellableBackgroundTask {
 		return builder.ToImmutable();
 	}
 
-	private async Task SendOutputToServer(ImmutableArray<string> lines) {
+	private void SendOutputToServer(ImmutableArray<string> lines) {
 		if (!lines.IsEmpty) {
-			await controllerConnection.Send(new InstanceOutputMessage(instanceGuid, lines));
+			controllerConnection.Send(new InstanceOutputMessage(instanceGuid, lines));
 		}
 	}
 

Agent/Phantom.Agent.Services/Instances/State/InstancePlayerCountTracker.cs

@@ -0,0 +1,140 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Rpc;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Tasks;
+using Phantom.Utils.Threading;
+
+namespace Phantom.Agent.Services.Instances.State;
+
+sealed class InstancePlayerCountTracker : CancellableBackgroundTask {
+	private readonly ControllerConnection controllerConnection;
+	private readonly Guid instanceGuid;
+	private readonly ushort serverPort;
+	private readonly InstanceProcess process;
+
+	private readonly TaskCompletionSource firstDetection = AsyncTasks.CreateCompletionSource();
+	private readonly ManualResetEventSlim serverOutputEvent = new ();
+
+	private InstancePlayerCounts? playerCounts;
+
+	public InstancePlayerCounts? PlayerCounts {
+		get {
+			lock (this) {
+				return playerCounts;
+			}
+		}
+		private set {
+			EventHandler<int?>? onlinePlayerCountChanged;
+			lock (this) {
+				if (playerCounts == value) {
+					return;
+				}
+				
+				playerCounts = value;
+				onlinePlayerCountChanged = OnlinePlayerCountChanged;
+			}
+
+			onlinePlayerCountChanged?.Invoke(this, value?.Online);
+			controllerConnection.Send(new ReportInstancePlayerCountsMessage(instanceGuid, value));
+		}
+	}
+
+	private event EventHandler<int?>? OnlinePlayerCountChanged;
+
+	private bool isDisposed = false;
+
+	public InstancePlayerCountTracker(InstanceContext context, InstanceProcess process, ushort serverPort) : base(PhantomLogger.Create<InstancePlayerCountTracker>(context.ShortName)) {
+		this.controllerConnection = context.Services.ControllerConnection;
+		this.instanceGuid = context.InstanceGuid;
+		this.process = process;
+		this.serverPort = serverPort;
+		Start();
+	}
+
+	protected override async Task RunTask() {
+		// Give the server time to start accepting connections.
+		await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
+
+		serverOutputEvent.Set();
+		process.AddOutputListener(OnOutput, maxLinesToReadFromHistory: 0);
+		
+		while (!CancellationToken.IsCancellationRequested) {
+			serverOutputEvent.Reset();
+
+			PlayerCounts = await TryGetPlayerCounts();
+			
+			if (!firstDetection.Task.IsCompleted) {
+				firstDetection.SetResult();
+			}
+
+			await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
+			await serverOutputEvent.WaitHandle.WaitOneAsync(CancellationToken);
+			await Task.Delay(TimeSpan.FromSeconds(1), CancellationToken);
+		}
+	}
+
+	private async Task<InstancePlayerCounts?> TryGetPlayerCounts() {
+		try {
+			var result = await ServerStatusProtocol.GetPlayerCounts(serverPort, CancellationToken);
+			Logger.Debug("Detected {OnlinePlayerCount} / {MaximumPlayerCount} online player(s).", result.Online, result.Maximum);
+			return result;
+		} catch (ServerStatusProtocol.ProtocolException e) {
+			Logger.Error(e.Message);
+			return null;
+		} catch (Exception e) {
+			Logger.Error(e, "Caught exception while checking online player count.");
+			return null;
+		}
+	}
+
+	public async Task WaitForOnlinePlayers(CancellationToken cancellationToken) {
+		await firstDetection.Task.WaitAsync(cancellationToken);
+
+		var onlinePlayersDetected = AsyncTasks.CreateCompletionSource();
+
+		lock (this) {
+			if (playerCounts is { Online: > 0 }) {
+				return;
+			}
+			else if (playerCounts == null) {
+				throw new InvalidOperationException();
+			}
+
+			OnlinePlayerCountChanged += OnOnlinePlayerCountChanged;
+
+			void OnOnlinePlayerCountChanged(object? sender, int? newPlayerCount) {
+				if (newPlayerCount == null) {
+					onlinePlayersDetected.TrySetException(new InvalidOperationException());
+					OnlinePlayerCountChanged -= OnOnlinePlayerCountChanged;
+				}
+				else if (newPlayerCount > 0) {
+					onlinePlayersDetected.TrySetResult();
+					OnlinePlayerCountChanged -= OnOnlinePlayerCountChanged;
+				}
+			}
+		}
+
+		await onlinePlayersDetected.Task;
+	}
+
+	private void OnOutput(object? sender, string? line) {
+		lock (this) {
+			if (!isDisposed) {
+				serverOutputEvent.Set();
+			}
+		}
+	}
+
+	protected override void Dispose() {
+		lock (this) {
+			isDisposed = true;
+			playerCounts = null;
+		}
+
+		process.RemoveOutputListener(OnOutput);
+		serverOutputEvent.Dispose();
+	}
+}

Agent/Phantom.Agent.Services/Instances/State/InstanceRunningState.cs

@@ -1,35 +1,41 @@
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Agent.Minecraft.Launcher;
 using Phantom.Agent.Services.Backups;
-using Phantom.Agent.Services.Instances.Procedures;
 using Phantom.Common.Data.Backups;
 using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Replies;
 
-namespace Phantom.Agent.Services.Instances.States;
+namespace Phantom.Agent.Services.Instances.State;
 
-sealed class InstanceRunningState : IInstanceState, IDisposable {
+sealed class InstanceRunningState : IDisposable {
+	public InstanceTicketManager.Ticket Ticket { get; }
 	public InstanceProcess Process { get; }
 
 	internal bool IsStopping { get; set; }
 
+	private readonly InstanceContext context;
 	private readonly InstanceConfiguration configuration;
 	private readonly IServerLauncher launcher;
-	private readonly IInstanceContext context;
+	private readonly CancellationToken cancellationToken;
 
 	private readonly InstanceLogSender logSender;
+	private readonly InstancePlayerCountTracker playerCountTracker;
 	private readonly BackupScheduler backupScheduler;
 
 	private bool isDisposed;
 
-	public InstanceRunningState(InstanceConfiguration configuration, IServerLauncher launcher, InstanceProcess process, IInstanceContext context) {
+	public InstanceRunningState(InstanceContext context, InstanceConfiguration configuration, IServerLauncher launcher, InstanceTicketManager.Ticket ticket, InstanceProcess process, CancellationToken cancellationToken) {
+		this.context = context;
 		this.configuration = configuration;
 		this.launcher = launcher;
-		this.context = context;
+		this.Ticket = ticket;
 		this.Process = process;
+		this.cancellationToken = cancellationToken;
 
-		this.logSender = new InstanceLogSender(context.Services.ControllerConnection, context.Services.TaskManager, configuration.InstanceGuid, context.ShortName);
+		this.logSender = new InstanceLogSender(context.Services.ControllerConnection, context.InstanceGuid, context.ShortName);
+		this.playerCountTracker = new InstancePlayerCountTracker(context, process, configuration.ServerPort);
 
-		this.backupScheduler = new BackupScheduler(context.Services.TaskManager, context.Services.BackupManager, process, context, configuration.ServerPort);
+		this.backupScheduler = new BackupScheduler(context, playerCountTracker);
 		this.backupScheduler.BackupCompleted += OnScheduledBackupCompleted;
 	}
 
@@ -39,7 +45,7 @@ sealed class InstanceRunningState : IInstanceState, IDisposable {
 		if (Process.HasEnded) {
 			if (TryDispose()) {
 				context.Logger.Warning("Session ended immediately after it was started.");
-				context.EnqueueProcedure(new SetInstanceToNotRunningStateProcedure(InstanceStatus.Failed(InstanceLaunchFailReason.UnknownError)), immediate: true);
+				context.Actor.Tell(new InstanceActor.HandleProcessEndedCommand(InstanceStatus.Failed(InstanceLaunchFailReason.UnknownError)));
 			}
 		}
 		else {
@@ -58,13 +64,17 @@ sealed class InstanceRunningState : IInstanceState, IDisposable {
 			return;
 		}
 
+		if (cancellationToken.IsCancellationRequested) {
+			return;
+		}
+		
 		if (IsStopping) {
-			context.EnqueueProcedure(new SetInstanceToNotRunningStateProcedure(InstanceStatus.NotRunning), immediate: true);
+			context.Actor.Tell(new InstanceActor.HandleProcessEndedCommand(InstanceStatus.NotRunning));
 		}
 		else {
 			context.Logger.Information("Session ended unexpectedly, restarting...");
 			context.ReportEvent(InstanceEvent.Crashed);
-			context.EnqueueProcedure(new LaunchInstanceProcedure(configuration, launcher, IsRestarting: true));
+			context.Actor.Tell(new InstanceActor.LaunchInstanceCommand(configuration, launcher, Ticket, IsRestarting: true));
 		}
 	}
 
@@ -72,19 +82,24 @@ sealed class InstanceRunningState : IInstanceState, IDisposable {
 		context.ReportEvent(new InstanceBackupCompletedEvent(e.Kind, e.Warnings));
 	}
 
-	public async Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
+	public async Task<SendCommandToInstanceResult> SendCommand(string command, CancellationToken cancellationToken) {
 		try {
 			context.Logger.Information("Sending command: {Command}", command);
 			await Process.SendCommand(command, cancellationToken);
-			return true;
+			return SendCommandToInstanceResult.Success;
 		} catch (OperationCanceledException) {
-			return false;
+			return SendCommandToInstanceResult.UnknownError;
 		} catch (Exception e) {
 			context.Logger.Warning(e, "Caught exception while sending command.");
-			return false;
+			return SendCommandToInstanceResult.UnknownError;
 		}
 	}
 
+	public void OnStopInitiated() {
+		backupScheduler.Stop();
+		playerCountTracker.Stop();
+	}
+	
 	private bool TryDispose() {
 		lock (this) {
 			if (isDisposed) {
@@ -94,11 +109,10 @@ sealed class InstanceRunningState : IInstanceState, IDisposable {
 			isDisposed = true;
 		}
 
+		OnStopInitiated();
 		logSender.Stop();
-		backupScheduler.Stop();
 		
 		Process.Dispose();
-		context.Services.PortManager.Release(configuration);
 		
 		return true;
 	}

Agent/Phantom.Agent.Services/Instances/State/InstanceStopProcedure.cs

@@ -1,51 +1,46 @@
 using System.Diagnostics;
 using Phantom.Agent.Minecraft.Command;
 using Phantom.Agent.Minecraft.Instance;
-using Phantom.Agent.Services.Instances.States;
 using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Minecraft;
 
-namespace Phantom.Agent.Services.Instances.Procedures;
+namespace Phantom.Agent.Services.Instances.State;
 
-sealed record StopInstanceProcedure(MinecraftStopStrategy StopStrategy) : IInstanceProcedure {
+static class InstanceStopProcedure {
 	private static readonly ushort[] Stops = { 60, 30, 10, 5, 4, 3, 2, 1, 0 };
 
-	public async Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken) {
-		if (context.CurrentState is not InstanceRunningState runningState) {
-			return null;
-		}
-
+	public static async Task<bool> Run(InstanceContext context, MinecraftStopStrategy stopStrategy, InstanceRunningState runningState, Action<IInstanceStatus> reportStatus, CancellationToken cancellationToken) {
 		var process = runningState.Process;
-
 		runningState.IsStopping = true;
-		context.SetStatus(InstanceStatus.Stopping);
 
-		var seconds = StopStrategy.Seconds;
+		var seconds = stopStrategy.Seconds;
 		if (seconds > 0) {
 			try {
 				await CountDownWithAnnouncements(context, process, seconds, cancellationToken);
 			} catch (OperationCanceledException) {
 				runningState.IsStopping = false;
-				return null;
+				return false;
 			}
 		}
 
 		try {
 			// Too late to cancel the stop procedure now.
+			runningState.OnStopInitiated();
+			
 			if (!process.HasEnded) {
 				context.Logger.Information("Session stopping now.");
 				await DoStop(context, process);
 			}
 		} finally {
 			context.Logger.Information("Session stopped.");
-			context.SetStatus(InstanceStatus.NotRunning);
+			reportStatus(InstanceStatus.NotRunning);
 			context.ReportEvent(InstanceEvent.Stopped);
 		}
 
-		return new InstanceNotRunningState();
+		return true;
 	}
 
-	private async Task CountDownWithAnnouncements(IInstanceContext context, InstanceProcess process, ushort seconds, CancellationToken cancellationToken) {
+	private static async Task CountDownWithAnnouncements(InstanceContext context, InstanceProcess process, ushort seconds, CancellationToken cancellationToken) {
 		context.Logger.Information("Session stopping in {Seconds} seconds.", seconds);
 
 		foreach (var stop in Stops) {
@@ -66,7 +61,7 @@ sealed record StopInstanceProcedure(MinecraftStopStrategy StopStrategy) : IInsta
 		return MinecraftCommand.Say("Server shutting down in " + seconds + (seconds == 1 ? " second." : " seconds."));
 	}
 
-	private async Task DoStop(IInstanceContext context, InstanceProcess process) {
+	private static async Task DoStop(InstanceContext context, InstanceProcess process) {
 		context.Logger.Information("Sending stop command...");
 		await TrySendStopCommand(context, process);
 
@@ -74,7 +69,7 @@ sealed record StopInstanceProcedure(MinecraftStopStrategy StopStrategy) : IInsta
 		await WaitForSessionToEnd(context, process);
 	}
 
-	private async Task TrySendStopCommand(IInstanceContext context, InstanceProcess process) {
+	private static async Task TrySendStopCommand(InstanceContext context, InstanceProcess process) {
 		using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(5));
 		try {
 			await process.SendCommand(MinecraftCommand.Stop, timeout.Token);
@@ -82,16 +77,17 @@ sealed record StopInstanceProcedure(MinecraftStopStrategy StopStrategy) : IInsta
 			// Ignore.
 		} catch (ObjectDisposedException e) when (e.ObjectName == typeof(Process).FullName && process.HasEnded) {
 			// Ignore.
+		} catch (IOException e) when (e.HResult == -2147024664 /* The pipe is being closed */) {
+			// Ignore.
 		} catch (Exception e) {
 			context.Logger.Warning(e, "Caught exception while sending stop command.");
 		}
 	}
 
-	private async Task WaitForSessionToEnd(IInstanceContext context, InstanceProcess process) {
-		using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(55));
+	private static async Task WaitForSessionToEnd(InstanceContext context, InstanceProcess process) {
 		try {
-			await process.WaitForExit(timeout.Token);
-		} catch (OperationCanceledException) {
+			await process.WaitForExit(TimeSpan.FromSeconds(55));
+		} catch (TimeoutException) {
 			try {
 				context.Logger.Warning("Waiting timed out, killing session...");
 				process.Kill();

Agent/Phantom.Agent.Services/Instances/States/IInstanceState.cs

@@ -1,6 +0,0 @@
-namespace Phantom.Agent.Services.Instances.States;
-
-interface IInstanceState {
-	void Initialize();
-	Task<bool> SendCommand(string command, CancellationToken cancellationToken);
-}

Agent/Phantom.Agent.Services/Instances/States/InstanceNotRunningState.cs

@@ -1,9 +0,0 @@
-namespace Phantom.Agent.Services.Instances.States;
-
-sealed class InstanceNotRunningState : IInstanceState {
-	public void Initialize() {}
-
-	public Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		return Task.FromResult(false);
-	}
-}

Agent/Phantom.Agent.Services/Rpc/ControllerMessageHandlerActor.cs

@@ -0,0 +1,101 @@
+using Phantom.Agent.Services.Instances;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Replies;
+using Phantom.Common.Messages.Agent;
+using Phantom.Common.Messages.Agent.BiDirectional;
+using Phantom.Common.Messages.Agent.ToAgent;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Rpc.Runtime;
+using Serilog;
+
+namespace Phantom.Agent.Services.Rpc;
+
+public sealed class ControllerMessageHandlerActor : ReceiveActor<IMessageToAgent> {
+	private static ILogger Logger { get; } = PhantomLogger.Create<ControllerMessageHandlerActor>();
+
+	public readonly record struct Init(RpcConnectionToServer<IMessageToController> Connection, AgentServices Agent, CancellationTokenSource ShutdownTokenSource);
+	
+	public static Props<IMessageToAgent> Factory(Init init) {
+		return Props<IMessageToAgent>.Create(() => new ControllerMessageHandlerActor(init), new ActorConfiguration { SupervisorStrategy = SupervisorStrategies.Resume });
+	}
+	
+	private readonly RpcConnectionToServer<IMessageToController> connection;
+	private readonly AgentServices agent;
+	private readonly CancellationTokenSource shutdownTokenSource;
+
+	private ControllerMessageHandlerActor(Init init) {
+		this.connection = init.Connection;
+		this.agent = init.Agent;
+		this.shutdownTokenSource = init.ShutdownTokenSource;
+		
+		ReceiveAsync<RegisterAgentSuccessMessage>(HandleRegisterAgentSuccess);
+		Receive<RegisterAgentFailureMessage>(HandleRegisterAgentFailure);
+		ReceiveAndReplyLater<ConfigureInstanceMessage, Result<ConfigureInstanceResult, InstanceActionFailure>>(HandleConfigureInstance);
+		ReceiveAndReplyLater<LaunchInstanceMessage, Result<LaunchInstanceResult, InstanceActionFailure>>(HandleLaunchInstance);
+		ReceiveAndReplyLater<StopInstanceMessage, Result<StopInstanceResult, InstanceActionFailure>>(HandleStopInstance);
+		ReceiveAndReplyLater<SendCommandToInstanceMessage, Result<SendCommandToInstanceResult, InstanceActionFailure>>(HandleSendCommandToInstance);
+		Receive<ReplyMessage>(HandleReply);
+	}
+
+	private async Task HandleRegisterAgentSuccess(RegisterAgentSuccessMessage message) {
+		Logger.Information("Agent authentication successful.");
+
+		void ShutdownAfterConfigurationFailed(Guid instanceGuid, InstanceConfiguration configuration) {
+			Logger.Fatal("Unable to configure instance \"{Name}\" (GUID {Guid}), shutting down.", configuration.InstanceName, instanceGuid);
+			shutdownTokenSource.Cancel();
+		}
+		
+		foreach (var configureInstanceMessage in message.InitialInstanceConfigurations) {
+			var result = await HandleConfigureInstance(configureInstanceMessage, alwaysReportStatus: true);
+			if (!result.Is(ConfigureInstanceResult.Success)) {
+				ShutdownAfterConfigurationFailed(configureInstanceMessage.InstanceGuid, configureInstanceMessage.Configuration);
+				return;
+			}
+		}
+
+		connection.SetIsReady();
+		
+		await connection.Send(new AdvertiseJavaRuntimesMessage(agent.JavaRuntimeRepository.All));
+		agent.InstanceTicketManager.RefreshAgentStatus();
+	}
+
+	private void HandleRegisterAgentFailure(RegisterAgentFailureMessage message) {
+		string errorMessage = message.FailureKind switch {
+			RegisterAgentFailure.ConnectionAlreadyHasAnAgent => "This connection already has an associated agent.",
+			RegisterAgentFailure.InvalidToken                => "Invalid token.",
+			_                                                => "Unknown error " + (byte) message.FailureKind + "."
+		};
+
+		Logger.Fatal("Agent authentication failed: {Error}", errorMessage);
+		
+		PhantomLogger.Dispose();
+		Environment.Exit(1);
+	}
+	
+	private Task<Result<ConfigureInstanceResult, InstanceActionFailure>> HandleConfigureInstance(ConfigureInstanceMessage message, bool alwaysReportStatus) {
+		return agent.InstanceManager.Request(new InstanceManagerActor.ConfigureInstanceCommand(message.InstanceGuid, message.Configuration, message.LaunchProperties, message.LaunchNow, alwaysReportStatus));
+	}
+	
+	private async Task<Result<ConfigureInstanceResult, InstanceActionFailure>> HandleConfigureInstance(ConfigureInstanceMessage message) {
+		return await HandleConfigureInstance(message, alwaysReportStatus: false);
+	}
+
+	private async Task<Result<LaunchInstanceResult, InstanceActionFailure>> HandleLaunchInstance(LaunchInstanceMessage message) {
+		return await agent.InstanceManager.Request(new InstanceManagerActor.LaunchInstanceCommand(message.InstanceGuid));
+	}
+
+	private async Task<Result<StopInstanceResult, InstanceActionFailure>> HandleStopInstance(StopInstanceMessage message) {
+		return await agent.InstanceManager.Request(new InstanceManagerActor.StopInstanceCommand(message.InstanceGuid, message.StopStrategy));
+	}
+
+	private async Task<Result<SendCommandToInstanceResult, InstanceActionFailure>> HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
+		return await agent.InstanceManager.Request(new InstanceManagerActor.SendCommandToInstanceCommand(message.InstanceGuid, message.Command));
+	}
+
+	private void HandleReply(ReplyMessage message) {
+		connection.Receive(message);
+	}
+}

Agent/Phantom.Agent.Services/Rpc/MessageListener.cs

@@ -1,88 +0,0 @@
-using Phantom.Common.Data.Instance;
-using Phantom.Common.Data.Replies;
-using Phantom.Common.Logging;
-using Phantom.Common.Messages.Agent;
-using Phantom.Common.Messages.Agent.BiDirectional;
-using Phantom.Common.Messages.Agent.ToAgent;
-using Phantom.Common.Messages.Agent.ToController;
-using Phantom.Utils.Rpc;
-using Phantom.Utils.Rpc.Message;
-using Serilog;
-
-namespace Phantom.Agent.Services.Rpc;
-
-public sealed class MessageListener : IMessageToAgentListener {
-	private static ILogger Logger { get; } = PhantomLogger.Create<MessageListener>();
-
-	private readonly RpcConnectionToServer<IMessageToControllerListener> connection;
-	private readonly AgentServices agent;
-	private readonly CancellationTokenSource shutdownTokenSource;
-
-	public MessageListener(RpcConnectionToServer<IMessageToControllerListener> connection, AgentServices agent, CancellationTokenSource shutdownTokenSource) {
-		this.connection = connection;
-		this.agent = agent;
-		this.shutdownTokenSource = shutdownTokenSource;
-	}
-
-	public async Task<NoReply> HandleRegisterAgentSuccess(RegisterAgentSuccessMessage message) {
-		Logger.Information("Agent authentication successful.");
-
-		void ShutdownAfterConfigurationFailed(InstanceConfiguration configuration) {
-			Logger.Fatal("Unable to configure instance \"{Name}\" (GUID {Guid}), shutting down.", configuration.InstanceName, configuration.InstanceGuid);
-			shutdownTokenSource.Cancel();
-		}
-		
-		foreach (var configureInstanceMessage in message.InitialInstanceConfigurations) {
-			var result = await HandleConfigureInstance(configureInstanceMessage, alwaysReportStatus: true);
-			if (!result.Is(ConfigureInstanceResult.Success)) {
-				ShutdownAfterConfigurationFailed(configureInstanceMessage.Configuration);
-				return NoReply.Instance;
-			}
-		}
-
-		await connection.Send(new AdvertiseJavaRuntimesMessage(agent.JavaRuntimeRepository.All));
-		await agent.InstanceSessionManager.RefreshAgentStatus();
-		
-		return NoReply.Instance;
-	}
-
-	public Task<NoReply> HandleRegisterAgentFailure(RegisterAgentFailureMessage message) {
-		string errorMessage = message.FailureKind switch {
-			RegisterAgentFailure.ConnectionAlreadyHasAnAgent => "This connection already has an associated agent.",
-			RegisterAgentFailure.InvalidToken                => "Invalid token.",
-			_                                                => "Unknown error " + (byte) message.FailureKind + "."
-		};
-
-		Logger.Fatal("Agent authentication failed: {Error}", errorMessage);
-		
-		PhantomLogger.Dispose();
-		Environment.Exit(1);
-
-		return Task.FromResult(NoReply.Instance);
-	}
-	
-	private Task<InstanceActionResult<ConfigureInstanceResult>> HandleConfigureInstance(ConfigureInstanceMessage message, bool alwaysReportStatus) {
-		return agent.InstanceSessionManager.Configure(message.Configuration, message.LaunchProperties, message.LaunchNow, alwaysReportStatus);
-	}
-	
-	public async Task<InstanceActionResult<ConfigureInstanceResult>> HandleConfigureInstance(ConfigureInstanceMessage message) {
-		return await HandleConfigureInstance(message, alwaysReportStatus: false);
-	}
-
-	public async Task<InstanceActionResult<LaunchInstanceResult>> HandleLaunchInstance(LaunchInstanceMessage message) {
-		return await agent.InstanceSessionManager.Launch(message.InstanceGuid);
-	}
-
-	public async Task<InstanceActionResult<StopInstanceResult>> HandleStopInstance(StopInstanceMessage message) {
-		return await agent.InstanceSessionManager.Stop(message.InstanceGuid, message.StopStrategy);
-	}
-
-	public async Task<InstanceActionResult<SendCommandToInstanceResult>> HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
-		return await agent.InstanceSessionManager.SendCommand(message.InstanceGuid, message.Command);
-	}
-
-	public Task<NoReply> HandleReply(ReplyMessage message) {
-		connection.Receive(message);
-		return Task.FromResult(NoReply.Instance);
-	}
-}

Agent/Phantom.Agent/AgentKey.cs

@@ -1,8 +1,8 @@
 using NetMQ;
 using Phantom.Common.Data;
-using Phantom.Common.Logging;
 using Phantom.Utils.Cryptography;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent;

Agent/Phantom.Agent/GuidFile.cs

@@ -1,6 +1,6 @@
 using System.Text;
-using Phantom.Common.Logging;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent;

Agent/Phantom.Agent/Program.cs

@@ -5,25 +5,26 @@ using Phantom.Agent.Rpc;
 using Phantom.Agent.Services;
 using Phantom.Agent.Services.Rpc;
 using Phantom.Common.Data.Agent;
-using Phantom.Common.Logging;
 using Phantom.Common.Messages.Agent;
 using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Logging;
 using Phantom.Utils.Rpc;
 using Phantom.Utils.Rpc.Sockets;
 using Phantom.Utils.Runtime;
-using Phantom.Utils.Tasks;
 
 const int ProtocolVersion = 1;
 
 var shutdownCancellationTokenSource = new CancellationTokenSource();
 var shutdownCancellationToken = shutdownCancellationTokenSource.Token;
 
+ProgramCulture.UseInvariantCulture();
+ThreadPool.SetMinThreads(workerThreads: 2, completionPortThreads: 1);
+
 PosixSignals.RegisterCancellation(shutdownCancellationTokenSource, static () => {
 	PhantomLogger.Root.InformationHeading("Stopping Phantom Panel agent...");
 });
 
-ThreadPool.SetMinThreads(workerThreads: 2, completionPortThreads: 1);
-
 try {
 	var fullVersion = AssemblyAttributes.GetFullVersion(Assembly.GetExecutingAssembly());
 
@@ -52,15 +53,17 @@ try {
 	
 	PhantomLogger.Root.InformationHeading("Launching Phantom Panel agent...");
 	
-	var rpcConfiguration = new RpcConfiguration(PhantomLogger.Create("Rpc"), PhantomLogger.Create<TaskManager>("Rpc"), controllerHost, controllerPort, controllerCertificate);
+	var rpcConfiguration = new RpcConfiguration("Agent", controllerHost, controllerPort, controllerCertificate);
 	var rpcSocket = RpcClientSocket.Connect(rpcConfiguration, AgentMessageRegistries.Definitions, new RegisterAgentMessage(agentToken, agentInfo));
 
 	var agentServices = new AgentServices(agentInfo, folders, new AgentServiceConfiguration(maxConcurrentBackupCompressionTasks), new ControllerConnection(rpcSocket.Connection));
 	await agentServices.Initialize();
 
+	var rpcMessageHandlerInit = new ControllerMessageHandlerActor.Init(rpcSocket.Connection, agentServices, shutdownCancellationTokenSource);
+	var rpcMessageHandlerActor = agentServices.ActorSystem.ActorOf(ControllerMessageHandlerActor.Factory(rpcMessageHandlerInit), "ControllerMessageHandler");
+	
 	var rpcDisconnectSemaphore = new SemaphoreSlim(0, 1);
-	var rpcMessageListener = new MessageListener(rpcSocket.Connection, agentServices, shutdownCancellationTokenSource);
-	var rpcTask = RpcClientRuntime.Launch(rpcSocket, agentInfo, rpcMessageListener, rpcDisconnectSemaphore, shutdownCancellationToken);
+	var rpcTask = RpcClientRuntime.Launch(rpcSocket, rpcMessageHandlerActor, rpcDisconnectSemaphore, shutdownCancellationToken);
 	try {
 		await rpcTask.WaitAsync(shutdownCancellationToken);
 	} finally {

Agent/Phantom.Agent/Variables.cs

@@ -1,6 +1,6 @@
 using Phantom.Agent.Minecraft.Java;
 using Phantom.Common.Data;
-using Phantom.Common.Logging;
+using Phantom.Utils.Logging;
 using Phantom.Utils.Runtime;
 
 namespace Phantom.Agent;

Common/Phantom.Common.Data.Web/Agent/Agent.cs

@@ -0,0 +1,15 @@
+using MemoryPack;
+using Phantom.Common.Data.Agent;
+
+namespace Phantom.Common.Data.Web.Agent;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record Agent(
+	[property: MemoryPackOrder(0)] Guid AgentGuid,
+	[property: MemoryPackOrder(1)] AgentConfiguration Configuration,
+	[property: MemoryPackOrder(2)] AgentStats? Stats,
+	[property: MemoryPackOrder(3)] IAgentConnectionStatus ConnectionStatus
+) {
+	[MemoryPackIgnore]
+	public RamAllocationUnits? AvailableMemory => Configuration.MaxMemory - Stats?.RunningInstanceMemory;
+}

Common/Phantom.Common.Data.Web/Agent/AgentConfiguration.cs

@@ -0,0 +1,19 @@
+using MemoryPack;
+using Phantom.Common.Data.Agent;
+
+namespace Phantom.Common.Data.Web.Agent;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record AgentConfiguration(
+	[property: MemoryPackOrder(0)] string AgentName,
+	[property: MemoryPackOrder(1)] ushort ProtocolVersion,
+	[property: MemoryPackOrder(2)] string BuildVersion,
+	[property: MemoryPackOrder(3)] ushort MaxInstances,
+	[property: MemoryPackOrder(4)] RamAllocationUnits MaxMemory,
+	[property: MemoryPackOrder(5)] AllowedPorts? AllowedServerPorts = null,
+	[property: MemoryPackOrder(6)] AllowedPorts? AllowedRconPorts = null
+) {
+	public static AgentConfiguration From(AgentInfo agentInfo) {
+		return new AgentConfiguration(agentInfo.AgentName, agentInfo.ProtocolVersion, agentInfo.BuildVersion, agentInfo.MaxInstances, agentInfo.MaxMemory, agentInfo.AllowedServerPorts, agentInfo.AllowedRconPorts);
+	}
+}

Common/Phantom.Common.Data.Web/Agent/AgentWithStats.cs

@@ -1,22 +0,0 @@
-using MemoryPack;
-using Phantom.Common.Data.Agent;
-
-namespace Phantom.Common.Data.Web.Agent;
-
-[MemoryPackable(GenerateType.VersionTolerant)]
-public sealed partial record AgentWithStats(
-	[property: MemoryPackOrder(0)] Guid Guid,
-	[property: MemoryPackOrder(1)] string Name,
-	[property: MemoryPackOrder(2)] ushort ProtocolVersion,
-	[property: MemoryPackOrder(3)] string BuildVersion,
-	[property: MemoryPackOrder(4)] ushort MaxInstances,
-	[property: MemoryPackOrder(5)] RamAllocationUnits MaxMemory,
-	[property: MemoryPackOrder(6)] AllowedPorts? AllowedServerPorts,
-	[property: MemoryPackOrder(7)] AllowedPorts? AllowedRconPorts,
-	[property: MemoryPackOrder(8)] AgentStats? Stats,
-	[property: MemoryPackOrder(9)] DateTimeOffset? LastPing,
-	[property: MemoryPackOrder(10)] bool IsOnline
-) {
-	[MemoryPackIgnore]
-	public RamAllocationUnits? AvailableMemory => MaxMemory - Stats?.RunningInstanceMemory;
-}

Common/Phantom.Common.Data.Web/Agent/IAgentConnectionStatus.cs

@@ -0,0 +1,27 @@
+using MemoryPack;
+
+namespace Phantom.Common.Data.Web.Agent;
+
+[MemoryPackable]
+[MemoryPackUnion(0, typeof(AgentIsOffline))]
+[MemoryPackUnion(1, typeof(AgentIsDisconnected))]
+[MemoryPackUnion(2, typeof(AgentIsOnline))]
+public partial interface IAgentConnectionStatus {}
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record AgentIsOffline : IAgentConnectionStatus;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record AgentIsDisconnected([property: MemoryPackOrder(0)] DateTimeOffset LastPingTime) : IAgentConnectionStatus;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record AgentIsOnline : IAgentConnectionStatus;
+
+public static class AgentConnectionStatus {
+	public static readonly IAgentConnectionStatus Offline = new AgentIsOffline();
+	public static readonly IAgentConnectionStatus Online = new AgentIsOnline();
+
+	public static IAgentConnectionStatus Disconnected(DateTimeOffset lastPingTime) {
+		return new AgentIsDisconnected(lastPingTime);
+	}
+}

Common/Phantom.Common.Data.Web/EventLog/EventLogEventType.cs

@@ -1,24 +1,24 @@
 namespace Phantom.Common.Data.Web.EventLog;
 
 public enum EventLogEventType {
-	InstanceLaunchSucceded,
+	InstanceLaunchSucceeded,
 	InstanceLaunchFailed,
 	InstanceCrashed,
 	InstanceStopped,
 	InstanceBackupSucceeded,
 	InstanceBackupSucceededWithWarnings,
-	InstanceBackupFailed,
+	InstanceBackupFailed
 }
 
 public static class EventLogEventTypeExtensions {
 	private static readonly Dictionary<EventLogEventType, EventLogSubjectType> SubjectTypes = new () {
-		{ EventLogEventType.InstanceLaunchSucceded, EventLogSubjectType.Instance },
+		{ EventLogEventType.InstanceLaunchSucceeded, EventLogSubjectType.Instance },
 		{ EventLogEventType.InstanceLaunchFailed, EventLogSubjectType.Instance },
 		{ EventLogEventType.InstanceCrashed, EventLogSubjectType.Instance },
 		{ EventLogEventType.InstanceStopped, EventLogSubjectType.Instance },
 		{ EventLogEventType.InstanceBackupSucceeded, EventLogSubjectType.Instance },
 		{ EventLogEventType.InstanceBackupSucceededWithWarnings, EventLogSubjectType.Instance },
-		{ EventLogEventType.InstanceBackupFailed, EventLogSubjectType.Instance },
+		{ EventLogEventType.InstanceBackupFailed, EventLogSubjectType.Instance }
 	};
 
 	static EventLogEventTypeExtensions() {

Common/Phantom.Common.Data.Web/Instance/Instance.cs

@@ -5,11 +5,13 @@ namespace Phantom.Common.Data.Web.Instance;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record Instance(
-	[property: MemoryPackOrder(0)] InstanceConfiguration Configuration,
-	[property: MemoryPackOrder(1)] IInstanceStatus Status,
-	[property: MemoryPackOrder(2)] bool LaunchAutomatically
+	[property: MemoryPackOrder(0)] Guid InstanceGuid,
+	[property: MemoryPackOrder(1)] InstanceConfiguration Configuration,
+	[property: MemoryPackOrder(2)] IInstanceStatus Status,
+	[property: MemoryPackOrder(3)] InstancePlayerCounts? PlayerCounts,
+	[property: MemoryPackOrder(4)] bool LaunchAutomatically
 ) {
-	public static Instance Offline(InstanceConfiguration configuration, bool launchAutomatically = false) {
-		return new Instance(configuration, InstanceStatus.Offline, launchAutomatically);
+	public static Instance Offline(Guid instanceGuid, InstanceConfiguration configuration, bool launchAutomatically = false) {
+		return new Instance(instanceGuid, configuration, InstanceStatus.Offline, PlayerCounts: null, launchAutomatically);
 	}
 }

Common/Phantom.Common.Data.Web/Users/AuthenticatedUserInfo.cs

@@ -0,0 +1,24 @@
+using System.Collections.Immutable;
+using MemoryPack;
+
+namespace Phantom.Common.Data.Web.Users;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record AuthenticatedUserInfo(
+	[property: MemoryPackOrder(0)] Guid Guid,
+	[property: MemoryPackOrder(1)] string Name,
+	[property: MemoryPackOrder(2)] PermissionSet Permissions,
+	[property: MemoryPackOrder(3)] ImmutableHashSet<Guid> ManagedAgentGuids
+) {
+	public bool CheckPermission(Permission permission) {
+		return Permissions.Check(permission);
+	}
+
+	public bool HasAccessToAgent(Guid agentGuid) {
+		return ManagedAgentGuids.Contains(agentGuid) || Permissions.Check(Permission.ManageAllAgents);
+	}
+
+	public ImmutableHashSet<Guid> FilterAccessibleAgentGuids(ImmutableHashSet<Guid> agentGuids) {
+		return Permissions.Check(Permission.ManageAllAgents) ? agentGuids : agentGuids.Intersect(ManagedAgentGuids);
+	}
+}

Common/Phantom.Common.Data.Web/Users/LogInSuccess.cs

@@ -4,8 +4,7 @@ using MemoryPack;
 namespace Phantom.Common.Data.Web.Users;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
-public sealed partial record LogInSuccess (
-	[property: MemoryPackOrder(0)] Guid UserGuid,
-	[property: MemoryPackOrder(1)] PermissionSet Permissions,
-	[property: MemoryPackOrder(2)] ImmutableArray<byte> Token
+public sealed partial record LogInSuccess(
+	[property: MemoryPackOrder(0)] AuthenticatedUserInfo UserInfo,
+	[property: MemoryPackOrder(1)] ImmutableArray<byte> AuthToken
 );

Common/Phantom.Common.Data.Web/Users/Permission.cs

@@ -14,6 +14,9 @@ public sealed record Permission(string Id, Permission? Parent) {
 		return Register(id, this);
 	}
 
+	public const string ManageAllAgentsPolicy = "Agents.ManageAll";
+	public static readonly Permission ManageAllAgents = Register(ManageAllAgentsPolicy);
+	
 	public const string ViewInstancesPolicy = "Instances.View";
 	public static readonly Permission ViewInstances = Register(ViewInstancesPolicy);
 	

Common/Phantom.Common.Data.Web/Users/UserActionFailure.cs

@@ -0,0 +1,5 @@
+namespace Phantom.Common.Data.Web.Users;
+
+public enum UserActionFailure {
+	NotAuthorized
+}

Common/Phantom.Common.Data.Web/Users/UserInstanceActionFailure.cs

@@ -0,0 +1,25 @@
+using MemoryPack;
+using Phantom.Common.Data.Replies;
+
+namespace Phantom.Common.Data.Web.Users;
+
+[MemoryPackable]
+[MemoryPackUnion(0, typeof(OfUserActionFailure))]
+[MemoryPackUnion(1, typeof(OfInstanceActionFailure))]
+public abstract partial record UserInstanceActionFailure {
+	internal UserInstanceActionFailure() {}
+	
+	public static implicit operator UserInstanceActionFailure(UserActionFailure failure) {
+		return new OfUserActionFailure(failure);
+	}
+	
+	public static implicit operator UserInstanceActionFailure(InstanceActionFailure failure) {
+		return new OfInstanceActionFailure(failure);
+	}
+}
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record OfUserActionFailure([property: MemoryPackOrder(0)] UserActionFailure Failure) : UserInstanceActionFailure;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record OfInstanceActionFailure([property: MemoryPackOrder(0)] InstanceActionFailure Failure) : UserInstanceActionFailure;

Common/Phantom.Common.Data/Agent/AgentInfo.cs

@@ -4,8 +4,8 @@ namespace Phantom.Common.Data.Agent;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record AgentInfo(
-	[property: MemoryPackOrder(0)] Guid Guid,
-	[property: MemoryPackOrder(1)] string Name,
+	[property: MemoryPackOrder(0)] Guid AgentGuid,
+	[property: MemoryPackOrder(1)] string AgentName,
 	[property: MemoryPackOrder(2)] ushort ProtocolVersion,
 	[property: MemoryPackOrder(3)] string BuildVersion,
 	[property: MemoryPackOrder(4)] ushort MaxInstances,

Common/Phantom.Common.Data/AuthToken.cs

@@ -14,9 +14,7 @@ public sealed partial class AuthToken {
 	private readonly byte[] bytes;
 
 	internal AuthToken(byte[]? bytes) {
-		if (bytes == null) {
-			throw new ArgumentNullException(nameof(bytes));
-		}
+		ArgumentNullException.ThrowIfNull(bytes);
 
 		if (bytes.Length != Length) {
 			throw new ArgumentOutOfRangeException(nameof(bytes), "Invalid token length: " + bytes.Length + ". Token length must be exactly " + Length + " bytes.");

Common/Phantom.Common.Data/Backups/BackupCreationResultKind.cs

@@ -1,15 +1,16 @@
 namespace Phantom.Common.Data.Backups;
 
 public enum BackupCreationResultKind : byte {
-	UnknownError,
-	Success,
-	InstanceNotRunning,
-	BackupCancelled,
-	BackupAlreadyRunning,
-	BackupFileAlreadyExists,
-	CouldNotCreateBackupFolder,
-	CouldNotCopyWorldToTemporaryFolder,
-	CouldNotCreateWorldArchive
+	UnknownError = 0,
+	Success = 1,
+	InstanceNotRunning = 2,
+	BackupTimedOut = 3,
+	BackupCancelled = 4,
+	BackupAlreadyRunning = 5,
+	BackupFileAlreadyExists = 6,
+	CouldNotCreateBackupFolder = 7,
+	CouldNotCopyWorldToTemporaryFolder = 8,
+	CouldNotCreateWorldArchive = 9
 }
 
 public static class BackupCreationResultSummaryExtensions {

Common/Phantom.Common.Data/Instance/IInstanceEvent.cs

@@ -4,7 +4,7 @@ using Phantom.Common.Data.Backups;
 namespace Phantom.Common.Data.Instance;
 
 [MemoryPackable]
-[MemoryPackUnion(0, typeof(InstanceLaunchSuccededEvent))]
+[MemoryPackUnion(0, typeof(InstanceLaunchSucceededEvent))]
 [MemoryPackUnion(1, typeof(InstanceLaunchFailedEvent))]
 [MemoryPackUnion(2, typeof(InstanceCrashedEvent))]
 [MemoryPackUnion(3, typeof(InstanceStoppedEvent))]
@@ -14,7 +14,7 @@ public partial interface IInstanceEvent {
 }
 
 [MemoryPackable(GenerateType.VersionTolerant)]
-public sealed partial record InstanceLaunchSuccededEvent : IInstanceEvent {
+public sealed partial record InstanceLaunchSucceededEvent : IInstanceEvent {
 	public void Accept(IInstanceEventVisitor visitor) {
 		visitor.OnLaunchSucceeded(this);
 	}
@@ -49,7 +49,7 @@ public sealed partial record InstanceBackupCompletedEvent([property: MemoryPackO
 }
 
 public static class InstanceEvent {
-	public static readonly IInstanceEvent LaunchSucceded = new InstanceLaunchSuccededEvent();
+	public static readonly IInstanceEvent LaunchSucceeded = new InstanceLaunchSucceededEvent();
 	public static readonly IInstanceEvent Crashed = new InstanceCrashedEvent();
 	public static readonly IInstanceEvent Stopped = new InstanceStoppedEvent();
 }

Common/Phantom.Common.Data/Instance/IInstanceEventVisitor.cs

@@ -1,7 +1,7 @@
 namespace Phantom.Common.Data.Instance;
 
 public interface IInstanceEventVisitor {
-	void OnLaunchSucceeded(InstanceLaunchSuccededEvent e);
+	void OnLaunchSucceeded(InstanceLaunchSucceededEvent e);
 	void OnLaunchFailed(InstanceLaunchFailedEvent e);
 	void OnCrashed(InstanceCrashedEvent e);
 	void OnStopped(InstanceStoppedEvent e);

Common/Phantom.Common.Data/Instance/IInstanceStatus.cs

@@ -9,9 +9,10 @@ namespace Phantom.Common.Data.Instance;
 [MemoryPackUnion(3, typeof(InstanceIsDownloading))]
 [MemoryPackUnion(4, typeof(InstanceIsLaunching))]
 [MemoryPackUnion(5, typeof(InstanceIsRunning))]
-[MemoryPackUnion(6, typeof(InstanceIsRestarting))]
-[MemoryPackUnion(7, typeof(InstanceIsStopping))]
-[MemoryPackUnion(8, typeof(InstanceIsFailed))]
+[MemoryPackUnion(6, typeof(InstanceIsBackingUp))]
+[MemoryPackUnion(7, typeof(InstanceIsRestarting))]
+[MemoryPackUnion(8, typeof(InstanceIsStopping))]
+[MemoryPackUnion(9, typeof(InstanceIsFailed))]
 public partial interface IInstanceStatus {}
 
 [MemoryPackable(GenerateType.VersionTolerant)]
@@ -32,6 +33,9 @@ public sealed partial record InstanceIsLaunching : IInstanceStatus;
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record InstanceIsRunning : IInstanceStatus;
 
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record InstanceIsBackingUp : IInstanceStatus;
+
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record InstanceIsRestarting : IInstanceStatus;
 
@@ -46,22 +50,35 @@ public static class InstanceStatus {
 	public static readonly IInstanceStatus NotRunning = new InstanceIsNotRunning();
 	public static readonly IInstanceStatus Launching = new InstanceIsLaunching();
 	public static readonly IInstanceStatus Running = new InstanceIsRunning();
+	public static readonly IInstanceStatus BackingUp = new InstanceIsBackingUp();
 	public static readonly IInstanceStatus Restarting = new InstanceIsRestarting();
 	public static readonly IInstanceStatus Stopping = new InstanceIsStopping();
 	
 	public static IInstanceStatus Invalid(string reason) => new InstanceIsInvalid(reason);
 	public static IInstanceStatus Downloading(byte progress) => new InstanceIsDownloading(progress);
 	public static IInstanceStatus Failed(InstanceLaunchFailReason reason) => new InstanceIsFailed(reason);
+
+	public static bool IsLaunching(this IInstanceStatus status) {
+		return status is InstanceIsDownloading or InstanceIsLaunching or InstanceIsRestarting;
+	}
+
+	public static bool IsRunning(this IInstanceStatus status) {
+		return status is InstanceIsRunning or InstanceIsBackingUp;
+	}
+	
+	public static bool IsStopping(this IInstanceStatus status) {
+		return status is InstanceIsStopping;
+	}
 	
 	public static bool CanLaunch(this IInstanceStatus status) {
 		return status is InstanceIsNotRunning or InstanceIsFailed;
 	}
 
 	public static bool CanStop(this IInstanceStatus status) {
-		return status is InstanceIsDownloading or InstanceIsLaunching or InstanceIsRunning;
+		return status.IsRunning() || status.IsLaunching();
 	}
 
 	public static bool CanSendCommand(this IInstanceStatus status) {
-		return status is InstanceIsRunning;
+		return status.IsRunning();
 	}
 }

Common/Phantom.Common.Data/Instance/InstanceConfiguration.cs

@@ -7,13 +7,12 @@ namespace Phantom.Common.Data.Instance;
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record InstanceConfiguration(
 	[property: MemoryPackOrder(0)] Guid AgentGuid,
-	[property: MemoryPackOrder(1)] Guid InstanceGuid,
-	[property: MemoryPackOrder(2)] string InstanceName,
-	[property: MemoryPackOrder(3)] ushort ServerPort,
-	[property: MemoryPackOrder(4)] ushort RconPort,
-	[property: MemoryPackOrder(5)] string MinecraftVersion,
-	[property: MemoryPackOrder(6)] MinecraftServerKind MinecraftServerKind,
-	[property: MemoryPackOrder(7)] RamAllocationUnits MemoryAllocation,
-	[property: MemoryPackOrder(8)] Guid JavaRuntimeGuid,
-	[property: MemoryPackOrder(9)] ImmutableArray<string> JvmArguments
+	[property: MemoryPackOrder(1)] string InstanceName,
+	[property: MemoryPackOrder(2)] ushort ServerPort,
+	[property: MemoryPackOrder(3)] ushort RconPort,
+	[property: MemoryPackOrder(4)] string MinecraftVersion,
+	[property: MemoryPackOrder(5)] MinecraftServerKind MinecraftServerKind,
+	[property: MemoryPackOrder(6)] RamAllocationUnits MemoryAllocation,
+	[property: MemoryPackOrder(7)] Guid JavaRuntimeGuid,
+	[property: MemoryPackOrder(8)] ImmutableArray<string> JvmArguments
 );

Common/Phantom.Common.Data/Instance/InstanceLaunchFailReason.cs

@@ -2,10 +2,6 @@
 
 public enum InstanceLaunchFailReason : byte {
 	UnknownError                           = 0,
-	ServerPortNotAllowed                   = 1,
-	ServerPortAlreadyInUse                 = 2,
-	RconPortNotAllowed                     = 3,
-	RconPortAlreadyInUse                   = 4,
 	JavaRuntimeNotFound                    = 5,
 	CouldNotDownloadMinecraftServer        = 6,
 	CouldNotConfigureMinecraftServer       = 7,

Common/Phantom.Common.Data/Instance/InstancePlayerCounts.cs

@@ -0,0 +1,9 @@
+using MemoryPack;
+
+namespace Phantom.Common.Data.Instance;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public readonly partial record struct InstancePlayerCounts(
+	[property: MemoryPackOrder(0)] int Online,
+	[property: MemoryPackOrder(1)] int Maximum
+);

Common/Phantom.Common.Data/Minecraft/MinecraftServerKind.cs

@@ -2,5 +2,6 @@
 
 public enum MinecraftServerKind : ushort {
 	Vanilla = 1,
-	Fabric = 2
+	Fabric = 2,
+	Forge = 3
 }

Common/Phantom.Common.Data/Optional.cs

@@ -0,0 +1,10 @@
+using MemoryPack;
+
+namespace Phantom.Common.Data;
+
+[MemoryPackable]
+public readonly partial record struct Optional<T>(T? Value) {
+	public static implicit operator Optional<T>(T? value) {
+		return new Optional<T>(value);
+	}
+}

Common/Phantom.Common.Data/Replies/ConfigureInstanceResult.cs

@@ -3,3 +3,12 @@
 public enum ConfigureInstanceResult : byte {
 	Success
 }
+
+public static class ConfigureInstanceResultExtensions {
+	public static string ToSentence(this ConfigureInstanceResult reason) {
+		return reason switch {
+			ConfigureInstanceResult.Success => "Success.",
+			_                               => "Unknown error."
+		};
+	}
+}

Common/Phantom.Common.Data/Replies/InstanceActionFailure.cs

@@ -0,0 +1,20 @@
+namespace Phantom.Common.Data.Replies;
+
+public enum InstanceActionFailure : byte {
+	AgentDoesNotExist,
+	AgentShuttingDown,
+	AgentIsNotResponding,
+	InstanceDoesNotExist
+}
+
+public static class InstanceActionFailureExtensions {
+	public static string ToSentence(this InstanceActionFailure failure) {
+		return failure switch {
+			InstanceActionFailure.AgentDoesNotExist    => "Agent does not exist.",
+			InstanceActionFailure.AgentShuttingDown    => "Agent is shutting down.",
+			InstanceActionFailure.AgentIsNotResponding => "Agent is not responding.",
+			InstanceActionFailure.InstanceDoesNotExist => "Instance does not exist.",
+			_                                          => "Unknown error."
+		};
+	}
+}

Common/Phantom.Common.Data/Replies/InstanceActionGeneralResult.cs

@@ -1,8 +0,0 @@
-namespace Phantom.Common.Data.Replies;
-
-public enum InstanceActionGeneralResult : byte {
-	None,
-	AgentShuttingDown,
-	AgentIsNotResponding,
-	InstanceDoesNotExist
-}

Common/Phantom.Common.Data/Replies/InstanceActionResult.cs

@@ -1,41 +0,0 @@
-using MemoryPack;
-
-namespace Phantom.Common.Data.Replies;
-
-[MemoryPackable(GenerateType.VersionTolerant)]
-public sealed partial record InstanceActionResult<T>(
-	[property: MemoryPackOrder(0)] InstanceActionGeneralResult GeneralResult,
-	[property: MemoryPackOrder(1)] T? ConcreteResult
-) {
-	public bool Is(T? concreteResult) {
-		return GeneralResult == InstanceActionGeneralResult.None && EqualityComparer<T>.Default.Equals(ConcreteResult, concreteResult);
-	}
-
-	public InstanceActionResult<T2> Map<T2>(Func<T, T2> mapper) {
-		return new InstanceActionResult<T2>(GeneralResult, ConcreteResult is not null ? mapper(ConcreteResult) : default);
-	}
-
-	public string ToSentence(Func<T, string> concreteResultToSentence) {
-		return GeneralResult switch {
-			InstanceActionGeneralResult.None                 => concreteResultToSentence(ConcreteResult!),
-			InstanceActionGeneralResult.AgentShuttingDown    => "Agent is shutting down.",
-			InstanceActionGeneralResult.AgentIsNotResponding => "Agent is not responding.",
-			InstanceActionGeneralResult.InstanceDoesNotExist => "Instance does not exist.",
-			_                                                => "Unknown result."
-		};
-	}
-}
-
-public static class InstanceActionResult {
-	public static InstanceActionResult<T> General<T>(InstanceActionGeneralResult generalResult) {
-		return new InstanceActionResult<T>(generalResult, default);
-	}
-
-	public static InstanceActionResult<T> Concrete<T>(T? concreteResult) {
-		return new InstanceActionResult<T>(InstanceActionGeneralResult.None, concreteResult);
-	}
-
-	public static InstanceActionResult<T> DidNotReplyIfNull<T>(this InstanceActionResult<T>? result) {
-		return result ?? General<T>(InstanceActionGeneralResult.AgentIsNotResponding);
-	}
-}

Common/Phantom.Common.Data/Replies/LaunchInstanceResult.cs

@@ -5,5 +5,9 @@ public enum LaunchInstanceResult : byte {
 	InstanceAlreadyLaunching = 2,
 	InstanceAlreadyRunning   = 3,
 	InstanceLimitExceeded    = 4,
-	MemoryLimitExceeded      = 5
+	MemoryLimitExceeded      = 5,
+	ServerPortNotAllowed     = 6,
+	ServerPortAlreadyInUse   = 7,
+	RconPortNotAllowed       = 8,
+	RconPortAlreadyInUse     = 9
 }

Common/Phantom.Common.Data/Replies/SendCommandToInstanceResult.cs

@@ -1,6 +1,7 @@
 namespace Phantom.Common.Data.Replies;
 
 public enum SendCommandToInstanceResult : byte {
-	UnknownError,
-	Success
+	UnknownError = 0,
+	Success = 1,
+	InstanceNotRunning = 2
 }

Common/Phantom.Common.Data/Result.cs

@@ -0,0 +1,108 @@
+using System.Diagnostics.CodeAnalysis;
+using MemoryPack;
+using Phantom.Utils.Result;
+
+namespace Phantom.Common.Data;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial class Result<TValue, TError> {
+	[MemoryPackOrder(0)]
+	[MemoryPackInclude]
+	private readonly bool hasValue;
+	
+	[MemoryPackOrder(1)]
+	[MemoryPackInclude]
+	private readonly TValue? value;
+	
+	[MemoryPackOrder(2)]
+	[MemoryPackInclude]
+	private readonly TError? error;
+
+	[MemoryPackIgnore]
+	public TValue Value => hasValue ? value! : throw new InvalidOperationException("Attempted to get value from an error result.");
+	
+	[MemoryPackIgnore]
+	public TError Error => !hasValue ? error! : throw new InvalidOperationException("Attempted to get error from a success result.");
+	
+	private Result(bool hasValue, TValue? value, TError? error) {
+		this.hasValue = hasValue;
+		this.value = value;
+		this.error = error;
+	}
+
+	public bool Is(TValue expectedValue) {
+		return hasValue && EqualityComparer<TValue>.Default.Equals(value, expectedValue);
+	}
+
+	public TOutput Into<TOutput>(Func<TValue, TOutput> valueConverter, Func<TError, TOutput> errorConverter) {
+		return hasValue ? valueConverter(value!) : errorConverter(error!);
+	}
+
+	public Result<TValue, TNewError> MapError<TNewError>(Func<TError, TNewError> errorConverter) {
+		return hasValue ? value! : errorConverter(error!);
+	}
+
+	public Utils.Result.Result Variant() {
+		return hasValue ? new Ok<TValue>(Value) : new Err<TError>(Error);
+	}
+
+	public static implicit operator Result<TValue, TError>(TValue value) {
+		return new Result<TValue, TError>(hasValue: true, value, default);
+	}
+	
+	public static implicit operator Result<TValue, TError>(TError error) {
+		return new Result<TValue, TError>(hasValue: false, default, error);
+	}
+
+	public static implicit operator bool(Result<TValue, TError> result) {
+		return result.hasValue;
+	}
+}
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial class Result<TError> {
+	[MemoryPackOrder(0)]
+	[MemoryPackInclude]
+	private readonly bool hasValue;
+	
+	[MemoryPackOrder(1)]
+	[MemoryPackInclude]
+	private readonly TError? error;
+
+	[MemoryPackIgnore]
+	public TError Error => !hasValue ? error! : throw new InvalidOperationException("Attempted to get error from a success result.");
+
+	private Result(bool hasValue, TError? error) {
+		this.hasValue = hasValue;
+		this.error = error;
+	}
+
+	public bool TryGetError([MaybeNullWhen(false)] out TError error) {
+		if (hasValue) {
+			error = default;
+			return false;
+		}
+		else {
+			error = this.error!;
+			return true;
+		}
+	}
+
+	public static implicit operator Result<TError>([SuppressMessage("ReSharper", "UnusedParameter.Global")] Result.OkType _) {
+		return new Result<TError>(hasValue: true, default);
+	}
+
+	public static implicit operator Result<TError>(TError error) {
+		return new Result<TError>(hasValue: false, error);
+	}
+
+	public static implicit operator bool(Result<TError> result) {
+		return result.hasValue;
+	}
+}
+
+public static class Result {
+	public static OkType Ok { get; }  = new ();
+
+	public readonly record struct OkType;
+}

Common/Phantom.Common.Messages.Agent/AgentMessageRegistries.cs

@@ -1,25 +1,26 @@
-using Phantom.Common.Data.Replies;
-using Phantom.Common.Logging;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Replies;
 using Phantom.Common.Messages.Agent.BiDirectional;
 using Phantom.Common.Messages.Agent.ToAgent;
 using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Logging;
 using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent;
 
 public static class AgentMessageRegistries {
-	public static MessageRegistry<IMessageToAgentListener> ToAgent { get; } = new (PhantomLogger.Create("MessageRegistry", nameof(ToAgent)));
-	public static MessageRegistry<IMessageToControllerListener> ToController { get; } = new (PhantomLogger.Create("MessageRegistry", nameof(ToController)));
+	public static MessageRegistry<IMessageToAgent> ToAgent { get; } = new (PhantomLogger.Create("MessageRegistry", nameof(ToAgent)));
+	public static MessageRegistry<IMessageToController> ToController { get; } = new (PhantomLogger.Create("MessageRegistry", nameof(ToController)));
 	
-	public static IMessageDefinitions<IMessageToAgentListener, IMessageToControllerListener, ReplyMessage> Definitions { get; } = new MessageDefinitions();
+	public static IMessageDefinitions<IMessageToAgent, IMessageToController, ReplyMessage> Definitions { get; } = new MessageDefinitions();
 
 	static AgentMessageRegistries() {
 		ToAgent.Add<RegisterAgentSuccessMessage>(0);
 		ToAgent.Add<RegisterAgentFailureMessage>(1);
-		ToAgent.Add<ConfigureInstanceMessage, InstanceActionResult<ConfigureInstanceResult>>(2);
-		ToAgent.Add<LaunchInstanceMessage, InstanceActionResult<LaunchInstanceResult>>(3);
-		ToAgent.Add<StopInstanceMessage, InstanceActionResult<StopInstanceResult>>(4);
-		ToAgent.Add<SendCommandToInstanceMessage, InstanceActionResult<SendCommandToInstanceResult>>(5);
+		ToAgent.Add<ConfigureInstanceMessage, Result<ConfigureInstanceResult, InstanceActionFailure>>(2);
+		ToAgent.Add<LaunchInstanceMessage, Result<LaunchInstanceResult, InstanceActionFailure>>(3);
+		ToAgent.Add<StopInstanceMessage, Result<StopInstanceResult, InstanceActionFailure>>(4);
+		ToAgent.Add<SendCommandToInstanceMessage, Result<SendCommandToInstanceResult, InstanceActionFailure>>(5);
 		ToAgent.Add<ReplyMessage>(127);
 		
 		ToController.Add<RegisterAgentMessage>(0);
@@ -30,16 +31,13 @@ public static class AgentMessageRegistries {
 		ToController.Add<InstanceOutputMessage>(5);
 		ToController.Add<ReportAgentStatusMessage>(6);
 		ToController.Add<ReportInstanceEventMessage>(7);
+		ToController.Add<ReportInstancePlayerCountsMessage>(8);
 		ToController.Add<ReplyMessage>(127);
 	}
 
-	private sealed class MessageDefinitions : IMessageDefinitions<IMessageToAgentListener, IMessageToControllerListener, ReplyMessage> {
-		public MessageRegistry<IMessageToAgentListener> ToClient => ToAgent;
-		public MessageRegistry<IMessageToControllerListener> ToServer => ToController;
-
-		public bool IsRegistrationMessage(Type messageType) {
-			return messageType == typeof(RegisterAgentMessage);
-		}
+	private sealed class MessageDefinitions : IMessageDefinitions<IMessageToAgent, IMessageToController, ReplyMessage> {
+		public MessageRegistry<IMessageToAgent> ToClient => ToAgent;
+		public MessageRegistry<IMessageToController> ToServer => ToController;
 
 		public ReplyMessage CreateReplyMessage(uint sequenceId, byte[] serializedReply) {
 			return new ReplyMessage(sequenceId, serializedReply);

Common/Phantom.Common.Messages.Agent/BiDirectional/ReplyMessage.cs

@@ -7,12 +7,4 @@ namespace Phantom.Common.Messages.Agent.BiDirectional;
 public sealed partial record ReplyMessage(
 	[property: MemoryPackOrder(0)] uint SequenceId,
 	[property: MemoryPackOrder(1)] byte[] SerializedReply
-) : IMessageToController, IMessageToAgent, IReply {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleReply(this);
-	}
-
-	public Task<NoReply> Accept(IMessageToAgentListener listener) {
-		return listener.HandleReply(this);
-	}
-}
+) : IMessageToController, IMessageToAgent, IReply;

Common/Phantom.Common.Messages.Agent/IMessageToAgent.cs

@@ -1,7 +1,3 @@
-using Phantom.Utils.Rpc.Message;
+namespace Phantom.Common.Messages.Agent;
 
-namespace Phantom.Common.Messages.Agent;
-
-public interface IMessageToAgent<TReply> : IMessage<IMessageToAgentListener, TReply> {}
-
-public interface IMessageToAgent : IMessageToAgent<NoReply> {}
+public interface IMessageToAgent {}

Common/Phantom.Common.Messages.Agent/IMessageToAgentListener.cs

@@ -1,16 +0,0 @@
-using Phantom.Common.Data.Replies;
-using Phantom.Common.Messages.Agent.BiDirectional;
-using Phantom.Common.Messages.Agent.ToAgent;
-using Phantom.Utils.Rpc.Message;
-
-namespace Phantom.Common.Messages.Agent;
-
-public interface IMessageToAgentListener {
-	Task<NoReply> HandleRegisterAgentSuccess(RegisterAgentSuccessMessage message);
-	Task<NoReply> HandleRegisterAgentFailure(RegisterAgentFailureMessage message);
-	Task<InstanceActionResult<ConfigureInstanceResult>> HandleConfigureInstance(ConfigureInstanceMessage message);
-	Task<InstanceActionResult<LaunchInstanceResult>> HandleLaunchInstance(LaunchInstanceMessage message);
-	Task<InstanceActionResult<StopInstanceResult>> HandleStopInstance(StopInstanceMessage message);
-	Task<InstanceActionResult<SendCommandToInstanceResult>> HandleSendCommandToInstance(SendCommandToInstanceMessage message);
-	Task<NoReply> HandleReply(ReplyMessage message);
-}

Common/Phantom.Common.Messages.Agent/IMessageToController.cs

@@ -1,7 +1,3 @@
-using Phantom.Utils.Rpc.Message;
+namespace Phantom.Common.Messages.Agent;
 
-namespace Phantom.Common.Messages.Agent;
-
-public interface IMessageToController<TReply> : IMessage<IMessageToControllerListener, TReply> {}
-
-public interface IMessageToController : IMessageToController<NoReply> {}
+public interface IMessageToController {}

Common/Phantom.Common.Messages.Agent/IMessageToControllerListener.cs

@@ -1,17 +0,0 @@
-using Phantom.Common.Messages.Agent.BiDirectional;
-using Phantom.Common.Messages.Agent.ToController;
-using Phantom.Utils.Rpc.Message;
-
-namespace Phantom.Common.Messages.Agent;
-
-public interface IMessageToControllerListener {
-	Task<NoReply> HandleRegisterAgent(RegisterAgentMessage message);
-	Task<NoReply> HandleUnregisterAgent(UnregisterAgentMessage message);
-	Task<NoReply> HandleAgentIsAlive(AgentIsAliveMessage message);
-	Task<NoReply> HandleAdvertiseJavaRuntimes(AdvertiseJavaRuntimesMessage message);
-	Task<NoReply> HandleReportAgentStatus(ReportAgentStatusMessage message);
-	Task<NoReply> HandleReportInstanceStatus(ReportInstanceStatusMessage message);
-	Task<NoReply> HandleReportInstanceEvent(ReportInstanceEventMessage message);
-	Task<NoReply> HandleInstanceOutput(InstanceOutputMessage message);
-	Task<NoReply> HandleReply(ReplyMessage message);
-}

Common/Phantom.Common.Messages.Agent/Phantom.Common.Messages.Agent.csproj

@@ -6,8 +6,8 @@
   </PropertyGroup>
   
   <ItemGroup>
-    <ProjectReference Include="..\Phantom.Common.Logging\Phantom.Common.Logging.csproj" />
     <ProjectReference Include="..\Phantom.Common.Data\Phantom.Common.Data.csproj" />
+    <ProjectReference Include="..\..\Utils\Phantom.Utils.Logging\Phantom.Utils.Logging.csproj" />
     <ProjectReference Include="..\..\Utils\Phantom.Utils.Rpc\Phantom.Utils.Rpc.csproj" />
   </ItemGroup>
 

Common/Phantom.Common.Messages.Agent/ToAgent/ConfigureInstanceMessage.cs

@@ -1,16 +1,15 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Replies;
+using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Agent.ToAgent;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record ConfigureInstanceMessage(
-	[property: MemoryPackOrder(0)] InstanceConfiguration Configuration,
-	[property: MemoryPackOrder(1)] InstanceLaunchProperties LaunchProperties,
-	[property: MemoryPackOrder(2)] bool LaunchNow = false
-) : IMessageToAgent<InstanceActionResult<ConfigureInstanceResult>> {
-	public Task<InstanceActionResult<ConfigureInstanceResult>> Accept(IMessageToAgentListener listener) {
-		return listener.HandleConfigureInstance(this);
-	}
-}
+	[property: MemoryPackOrder(0)] Guid InstanceGuid,
+	[property: MemoryPackOrder(1)] InstanceConfiguration Configuration,
+	[property: MemoryPackOrder(2)] InstanceLaunchProperties LaunchProperties,
+	[property: MemoryPackOrder(3)] bool LaunchNow = false
+) : IMessageToAgent, ICanReply<Result<ConfigureInstanceResult, InstanceActionFailure>>;

Common/Phantom.Common.Messages.Agent/ToAgent/LaunchInstanceMessage.cs

@@ -1,13 +1,11 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Replies;
+using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Agent.ToAgent;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record LaunchInstanceMessage(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid
-) : IMessageToAgent<InstanceActionResult<LaunchInstanceResult>> {
-	public Task<InstanceActionResult<LaunchInstanceResult>> Accept(IMessageToAgentListener listener) {
-		return listener.HandleLaunchInstance(this);
-	}
-}
+) : IMessageToAgent, ICanReply<Result<LaunchInstanceResult, InstanceActionFailure>>;

Common/Phantom.Common.Messages.Agent/ToAgent/RegisterAgentFailureMessage.cs

@@ -1,14 +1,9 @@
 using MemoryPack;
 using Phantom.Common.Data.Replies;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToAgent;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record RegisterAgentFailureMessage(
 	[property: MemoryPackOrder(0)] RegisterAgentFailure FailureKind
-) : IMessageToAgent {
-	public Task<NoReply> Accept(IMessageToAgentListener listener) {
-		return listener.HandleRegisterAgentFailure(this);
-	}
-}
+) : IMessageToAgent;

Common/Phantom.Common.Messages.Agent/ToAgent/RegisterAgentSuccessMessage.cs

@@ -1,14 +1,9 @@
 using System.Collections.Immutable;
 using MemoryPack;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToAgent;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record RegisterAgentSuccessMessage(
 	[property: MemoryPackOrder(0)] ImmutableArray<ConfigureInstanceMessage> InitialInstanceConfigurations
-) : IMessageToAgent {
-	public Task<NoReply> Accept(IMessageToAgentListener listener) {
-		return listener.HandleRegisterAgentSuccess(this);
-	}
-}
+) : IMessageToAgent;

Common/Phantom.Common.Messages.Agent/ToAgent/SendCommandToInstanceMessage.cs

@@ -1,5 +1,7 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Replies;
+using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Agent.ToAgent;
 
@@ -7,8 +9,4 @@ namespace Phantom.Common.Messages.Agent.ToAgent;
 public sealed partial record SendCommandToInstanceMessage(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid,
 	[property: MemoryPackOrder(1)] string Command
-) : IMessageToAgent<InstanceActionResult<SendCommandToInstanceResult>> {
-	public Task<InstanceActionResult<SendCommandToInstanceResult>> Accept(IMessageToAgentListener listener) {
-		return listener.HandleSendCommandToInstance(this);
-	}
-}
+) : IMessageToAgent, ICanReply<Result<SendCommandToInstanceResult, InstanceActionFailure>>;

Common/Phantom.Common.Messages.Agent/ToAgent/StopInstanceMessage.cs

@@ -1,6 +1,8 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
+using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Agent.ToAgent;
 
@@ -8,8 +10,4 @@ namespace Phantom.Common.Messages.Agent.ToAgent;
 public sealed partial record StopInstanceMessage(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid,
 	[property: MemoryPackOrder(1)] MinecraftStopStrategy StopStrategy
-) : IMessageToAgent<InstanceActionResult<StopInstanceResult>> {
-	public Task<InstanceActionResult<StopInstanceResult>> Accept(IMessageToAgentListener listener) {
-		return listener.HandleStopInstance(this);
-	}
-}
+) : IMessageToAgent, ICanReply<Result<StopInstanceResult, InstanceActionFailure>>;

Common/Phantom.Common.Messages.Agent/ToController/AdvertiseJavaRuntimesMessage.cs

@@ -1,15 +1,10 @@
 using System.Collections.Immutable;
 using MemoryPack;
 using Phantom.Common.Data.Java;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record AdvertiseJavaRuntimesMessage(
 	[property: MemoryPackOrder(0)] ImmutableArray<TaggedJavaRuntime> Runtimes
-) : IMessageToController {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleAdvertiseJavaRuntimes(this);
-	}
-}
+) : IMessageToController;

Common/Phantom.Common.Messages.Agent/ToController/AgentIsAliveMessage.cs

@@ -1,11 +1,6 @@
 using MemoryPack;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
-public sealed partial record AgentIsAliveMessage : IMessageToController {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleAgentIsAlive(this);
-	}
-}
+public sealed partial record AgentIsAliveMessage : IMessageToController;

Common/Phantom.Common.Messages.Agent/ToController/InstanceOutputMessage.cs

@@ -1,6 +1,5 @@
 using System.Collections.Immutable;
 using MemoryPack;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToController;
 
@@ -8,8 +7,4 @@ namespace Phantom.Common.Messages.Agent.ToController;
 public sealed partial record InstanceOutputMessage(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid,
 	[property: MemoryPackOrder(1)] ImmutableArray<string> Lines
-) : IMessageToController {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleInstanceOutput(this);
-	}
-}
+) : IMessageToController;

Common/Phantom.Common.Messages.Agent/ToController/RegisterAgentMessage.cs

@@ -1,7 +1,6 @@
 using MemoryPack;
 using Phantom.Common.Data;
 using Phantom.Common.Data.Agent;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToController;
 
@@ -9,8 +8,4 @@ namespace Phantom.Common.Messages.Agent.ToController;
 public sealed partial record RegisterAgentMessage(
 	[property: MemoryPackOrder(0)] AuthToken AuthToken,
 	[property: MemoryPackOrder(1)] AgentInfo AgentInfo
-) : IMessageToController {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleRegisterAgent(this);
-	}
-}
+) : IMessageToController;

Common/Phantom.Common.Messages.Agent/ToController/ReportAgentStatusMessage.cs

@@ -1,6 +1,5 @@
 using MemoryPack;
 using Phantom.Common.Data;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToController;
 
@@ -8,8 +7,4 @@ namespace Phantom.Common.Messages.Agent.ToController;
 public sealed partial record ReportAgentStatusMessage(
 	[property: MemoryPackOrder(0)] int RunningInstanceCount,
 	[property: MemoryPackOrder(1)] RamAllocationUnits RunningInstanceMemory
-) : IMessageToController {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleReportAgentStatus(this);
-	}
-}
+) : IMessageToController;

Common/Phantom.Common.Messages.Agent/ToController/ReportInstanceEventMessage.cs

@@ -1,6 +1,5 @@
 using MemoryPack;
 using Phantom.Common.Data.Instance;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToController;
 
@@ -10,8 +9,4 @@ public sealed partial record ReportInstanceEventMessage(
 	[property: MemoryPackOrder(1)] DateTime UtcTime,
 	[property: MemoryPackOrder(2)] Guid InstanceGuid,
 	[property: MemoryPackOrder(3)] IInstanceEvent Event
-) : IMessageToController {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleReportInstanceEvent(this);
-	}
-}
+) : IMessageToController;

Common/Phantom.Common.Messages.Agent/ToController/ReportInstancePlayerCountsMessage.cs

@@ -0,0 +1,10 @@
+using MemoryPack;
+using Phantom.Common.Data.Instance;
+
+namespace Phantom.Common.Messages.Agent.ToController;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record ReportInstancePlayerCountsMessage(
+	[property: MemoryPackOrder(0)] Guid InstanceGuid,
+	[property: MemoryPackOrder(1)] InstancePlayerCounts? PlayerCounts
+) : IMessageToController;

Common/Phantom.Common.Messages.Agent/ToController/ReportInstanceStatusMessage.cs

@@ -1,6 +1,5 @@
 using MemoryPack;
 using Phantom.Common.Data.Instance;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToController;
 
@@ -8,8 +7,4 @@ namespace Phantom.Common.Messages.Agent.ToController;
 public sealed partial record ReportInstanceStatusMessage(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid,
 	[property: MemoryPackOrder(1)] IInstanceStatus InstanceStatus
-) : IMessageToController {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleReportInstanceStatus(this);
-	}
-}
+) : IMessageToController;

Common/Phantom.Common.Messages.Agent/ToController/UnregisterAgentMessage.cs

@@ -1,11 +1,6 @@
 using MemoryPack;
-using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.Agent.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
-public sealed partial record UnregisterAgentMessage : IMessageToController {
-	public Task<NoReply> Accept(IMessageToControllerListener listener) {
-		return listener.HandleUnregisterAgent(this);
-	}
-}
+public sealed partial record UnregisterAgentMessage : IMessageToController;