Fix this

build/Version.props

@@ -3,8 +3,8 @@
     <!-- This is the authorative version list -->
     <!-- Integration tests will ensure they match across the board -->
     <TgsCoreVersion>4.2.1</TgsCoreVersion>
-    <TgsApiVersion>6.2.0</TgsApiVersion>
-    <TgsClientVersion>6.1.0</TgsClientVersion>
+    <TgsApiVersion>6.3.0</TgsApiVersion>
+    <TgsClientVersion>6.2.0</TgsClientVersion>
     <TgsDmapiVersion>5.1.1</TgsDmapiVersion>
     <TgsControlPanelVersion>0.4.0</TgsControlPanelVersion>
     <TgsHostWatchdogVersion>1.1.0</TgsHostWatchdogVersion>

src/Tgstation.Server.Api/Models/ErrorCode.cs

@@ -471,5 +471,11 @@ namespace Tgstation.Server.Api.Models
 		/// </summary>
 		[Description("Cannot set both softShutdown and softReboot at once!")]
 		DreamDaemonDoubleSoft,
+
+		/// <summary>
+		/// Attempted to launch DreamDaemon on a user account that had the BYOND pager running.
+		/// </summary>
+		[Description("Cannot start DreamDaemon headless with the BYOND pager running!")]
+		DeploymentPagerRunning,
 	}
 }

src/Tgstation.Server.Host/Components/Session/SessionControllerFactory.cs

@@ -201,7 +201,7 @@ namespace Tgstation.Server.Host.Components.Session
 					if (launchParameters.SecurityLevel == DreamDaemonSecurity.Trusted)
 						await byondLock.TrustDmbPath(ioManager.ConcatPath(basePath, dmbProvider.DmbName), cancellationToken).ConfigureAwait(false);
 
-					CheckPagerIsNotRunning();
+					await CheckPagerIsNotRunning(cancellationToken).ConfigureAwait(false);
 
 					var accessIdentifier = cryptographySuite.GetSecureString();
 
@@ -403,10 +403,24 @@ namespace Tgstation.Server.Host.Components.Session
 		/// <summary>
 		/// Make sure the BYOND pager is not running.
 		/// </summary>
-		void CheckPagerIsNotRunning()
+		/// <param name="cancellationToken">The <see cref="CancellationToken"/> for the operation.</param>
+		/// <returns>A <see cref="Task"/> representing the running operation.</returns>
+		async Task CheckPagerIsNotRunning(CancellationToken cancellationToken)
 		{
-			if (platformIdentifier.IsWindows && processExecutor.IsProcessWithNameRunning("byond"))
-				throw new JobException("Cannot start DreamDaemon headless with the BYOND pager running!");
+			if (!platformIdentifier.IsWindows)
+				return;
+
+			using var otherProcess = processExecutor.GetProcessByName("byond");
+			if (otherProcess == null)
+				return;
+
+			var otherUsernameTask = otherProcess.GetExecutingUsername(cancellationToken);
+			using var ourProcess = processExecutor.GetCurrentProcess();
+			var ourUserName = await ourProcess.GetExecutingUsername(cancellationToken).ConfigureAwait(false);
+			var otherUserName = await otherUsernameTask.ConfigureAwait(false);
+
+			if(otherUserName.Equals(ourUserName, StringComparison.Ordinal))
+				throw new JobException(ErrorCode.DeploymentPagerRunning);
 		}
 	}
 }

src/Tgstation.Server.Host/System/IProcessExecutor.cs

@@ -18,17 +18,23 @@
 		IProcess LaunchProcess(string fileName, string workingDirectory, string arguments = null, bool readOutput = false, bool readError = false, bool noShellExecute = false);
 
 		/// <summary>
-		/// Get a <see cref="IProcess"/> by <paramref name="id"/>
+		/// Get a <see cref="IProcess"/> representing the running executable.
 		/// </summary>
-		/// <param name="id">The <see cref="IProcess.Id"/></param>
-		/// <returns>The <see cref="IProcess"/> represented by <paramref name="id"/> on success, <see langword="null"/> on failure</returns>
+		/// <returns>The current <see cref="IProcess"/>.</returns>
+		IProcess GetCurrentProcess();
+
+		/// <summary>
+		/// Get a <see cref="IProcess"/> by <paramref name="id"/>.
+		/// </summary>
+		/// <param name="id">The <see cref="IProcess.Id"/>.</param>
+		/// <returns>The <see cref="IProcess"/> represented by <paramref name="id"/> on success, <see langword="null"/> on failure.</returns>
 		IProcess GetProcess(int id);
 
 		/// <summary>
-		/// Check if a <see cref="IProcess"/> with a given <paramref name="name"/> is running.
+		/// Get a <see cref="IProcess"/> with a given <paramref name="name"/>.
 		/// </summary>
-		/// <param name="name">The name of the process without the extension.</param>
-		/// <returns><see langword="true"/> if the process is running, <see langword="false"/> otherwise.</returns>
-		bool IsProcessWithNameRunning(string name);
+		/// <param name="name">The name of the process executable without the extension.</param>
+		/// <returns>The <see cref="IProcess"/> represented by <paramref name="name"/> on success, <see langword="null"/> on failure.</returns>
+		IProcess GetProcessByName(string name);
 	}
 }

src/Tgstation.Server.Host/System/ProcessExecutor.cs

@@ -1,6 +1,5 @@
 using Microsoft.Extensions.Logging;
 using System;
-using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
@@ -83,23 +82,15 @@ namespace Tgstation.Server.Host.System
 				return null;
 			}
 
-			try
-			{
-				return new Process(
-					processFeatures,
-					handle,
-					AttachExitHandler(handle),
-					null,
-					null,
-					null,
-					loggerFactory.CreateLogger<Process>(),
-					true);
-			}
-			catch
-			{
-				handle.Dispose();
-				throw;
-			}
+			return CreateFromExistingHandle(handle);
+		}
+
+		/// <inheritdoc />
+		public IProcess GetCurrentProcess()
+		{
+			logger.LogTrace("Getting current process...");
+			var handle = global::System.Diagnostics.Process.GetCurrentProcess();
+			return CreateFromExistingHandle(handle);
 		}
 
 		/// <inheritdoc />
@@ -231,13 +222,50 @@ namespace Tgstation.Server.Host.System
 		}
 
 		/// <inheritdoc />
-		public bool IsProcessWithNameRunning(string name)
+		public IProcess GetProcessByName(string name)
 		{
+			logger.LogTrace("GetProcessByName: {0}...", name ?? throw new ArgumentNullException(nameof(name)));
 			var procs = global::System.Diagnostics.Process.GetProcessesByName(name);
+			global::System.Diagnostics.Process handle = null;
 			foreach (var proc in procs)
-				proc.Dispose();
+				if (handle == null)
+					handle = proc;
+				else
+				{
+					logger.LogTrace("Disposing extra found PID: {0}", proc.Id);
+					proc.Dispose();
+				}
 
-			return procs.Any();
+			if (handle == null)
+				return null;
+
+			return CreateFromExistingHandle(handle);
+		}
+
+		/// <summary>
+		/// Create a <see cref="IProcess"/> given an existing <paramref name="handle"/>.
+		/// </summary>
+		/// <param name="handle">The <see cref="global::System.Diagnostics.Process"/> to create a <see cref="IProcess"/> from.</param>
+		/// <returns>The <see cref="IProcess"/> based on <paramref name="handle"/>.</returns>
+		private IProcess CreateFromExistingHandle(global::System.Diagnostics.Process handle)
+		{
+			try
+			{
+				return new Process(
+					processFeatures,
+					handle,
+					AttachExitHandler(handle),
+					null,
+					null,
+					null,
+					loggerFactory.CreateLogger<Process>(),
+					true);
+			}
+			catch
+			{
+				handle.Dispose();
+				throw;
+			}
 		}
 	}
 }

tests/Tgstation.Server.Tests/Instance/WatchdogTest.cs

@@ -12,6 +12,7 @@ using Tgstation.Server.Api.Models;
 using Tgstation.Server.Client;
 using Tgstation.Server.Client.Components;
 using Tgstation.Server.Host.Components.Interop;
+using Tgstation.Server.Host.IO;
 using Tgstation.Server.Host.System;
 
 namespace Tgstation.Server.Tests.Instance
@@ -102,7 +103,7 @@ namespace Tgstation.Server.Tests.Instance
 			using var ourProcessHandler = new ProcessExecutor(
 				new PlatformIdentifier().IsWindows
 					? (IProcessFeatures)new WindowsProcessFeatures(Mock.Of<ILogger<WindowsProcessFeatures>>())
-					: new PosixProcessFeatures(Mock.Of<ILogger<PosixProcessFeatures>>()),
+					: new PosixProcessFeatures(Mock.Of<IIOManager>(), Mock.Of<ILogger<PosixProcessFeatures>>()),
 				Mock.Of<ILogger<ProcessExecutor>>(),
 				LoggerFactory.Create(x => { }))
 				.GetProcess(ddProc.Id);