Move all code related to single instance logic to separate class (#2871)

ILSpy/App.xaml.cs

@@ -24,7 +24,6 @@ using System.Linq;
 using System.Reflection;
 using System.Runtime.Loader;
 using System.Text;
-using System.Threading;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Documents;
@@ -47,7 +46,6 @@ namespace ICSharpCode.ILSpy
 	{
 		internal static CommandLineArguments CommandLineArguments;
 		internal static readonly IList<ExceptionData> StartupExceptions = new List<ExceptionData>();
-		internal static Mutex SingleInstanceMutex;
 
 		public static ExportProvider ExportProvider { get; private set; }
 		public static IExportProviderFactory ExportProviderFactory { get; private set; }
@@ -64,38 +62,14 @@ namespace ICSharpCode.ILSpy
 
 			var cmdArgs = Environment.GetCommandLineArgs().Skip(1);
 			App.CommandLineArguments = new CommandLineArguments(cmdArgs);
+
 			bool forceSingleInstance = (App.CommandLineArguments.SingleInstance ?? true)
 				&& !MiscSettingsPanel.CurrentMiscSettings.AllowMultipleInstances;
 			if (forceSingleInstance)
 			{
-				bool isFirst;
+				SingleInstanceHandling.ForceSingleInstance(cmdArgs);
-				try
-				{
-					SingleInstanceMutex = new Mutex(initiallyOwned: true, @"Local\ILSpyInstance", out isFirst);
-				}
-				catch (WaitHandleCannotBeOpenedException)
-				{
-					isFirst = true;
-				}
-				if (!isFirst)
-				{
-					try
-					{
-						SingleInstanceMutex.WaitOne(10000);
-					}
-					catch (AbandonedMutexException)
-					{
-						// continue, there is no concurrent start happening.
-					}
-				}
-				cmdArgs = cmdArgs.Select(FullyQualifyPath);
-				string message = string.Join(Environment.NewLine, cmdArgs);
-				if (SendToPreviousInstance("ILSpy:\r\n" + message, !App.CommandLineArguments.NoActivate))
-				{
-					ReleaseSingleInstanceMutex();
-					Environment.Exit(0);
-				}
 			}
+
 			InitializeComponent();
 
 			Resources.RegisterDefaultStyles();
@@ -114,20 +88,6 @@ namespace ICSharpCode.ILSpy
 			ILSpyTraceListener.Install();
 		}
 
-		internal static void ReleaseSingleInstanceMutex()
-		{
-			var mutex = SingleInstanceMutex;
-			SingleInstanceMutex = null;
-			if (mutex == null)
-			{
-				return;
-			}
-			using (mutex)
-			{
-				mutex.ReleaseMutex();
-			}
-		}
-
 		static Assembly ResolvePluginDependencies(AssemblyLoadContext context, AssemblyName assemblyName)
 		{
 			var rootPath = Path.GetDirectoryName(typeof(App).Assembly.Location);
@@ -210,22 +170,6 @@ namespace ICSharpCode.ILSpy
 			base.OnStartup(e);
 		}
 
-		string FullyQualifyPath(string argument)
-		{
-			// Fully qualify the paths before passing them to another process,
-			// because that process might use a different current directory.
-			if (string.IsNullOrEmpty(argument) || argument[0] == '/')
-				return argument;
-			try
-			{
-				return Path.Combine(Environment.CurrentDirectory, argument);
-			}
-			catch (ArgumentException)
-			{
-				return argument;
-			}
-		}
-
 		void DotNet40_UnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs e)
 		{
 			// On .NET 4.0, an unobserved exception in a task terminates the process unless we mark it as observed
@@ -282,67 +226,6 @@ namespace ICSharpCode.ILSpy
 		}
 		#endregion
 
-		#region Pass Command Line Arguments to previous instance
-		bool SendToPreviousInstance(string message, bool activate)
-		{
-			string ownProcessName;
-			using (var ownProcess = Process.GetCurrentProcess())
-			{
-				ownProcessName = ownProcess.ProcessName;
-			}
-
-			bool success = false;
-			NativeMethods.EnumWindows(
-				(hWnd, lParam) => {
-					string windowTitle = NativeMethods.GetWindowText(hWnd, 100);
-					if (windowTitle.StartsWith("ILSpy", StringComparison.Ordinal))
-					{
-						string processName = NativeMethods.GetProcessNameFromWindow(hWnd);
-						Debug.WriteLine("Found {0:x4}: '{1}' in '{2}'", hWnd, windowTitle, processName);
-						if (string.Equals(processName, ownProcessName, StringComparison.OrdinalIgnoreCase))
-						{
-							IntPtr result = Send(hWnd, message);
-							Debug.WriteLine("WM_COPYDATA result: {0:x8}", result);
-							if (result == (IntPtr)1)
-							{
-								if (activate)
-									NativeMethods.SetForegroundWindow(hWnd);
-								success = true;
-								return false; // stop enumeration
-							}
-						}
-					}
-					return true; // continue enumeration
-				}, IntPtr.Zero);
-			return success;
-		}
-
-		unsafe static IntPtr Send(IntPtr hWnd, string message)
-		{
-			const uint SMTO_NORMAL = 0;
-
-			CopyDataStruct lParam;
-			lParam.Padding = IntPtr.Zero;
-			lParam.Size = message.Length * 2;
-			fixed (char* buffer = message)
-			{
-				lParam.Buffer = (IntPtr)buffer;
-				IntPtr result;
-				// SendMessage with 3s timeout (e.g. when the target process is stopped in the debugger)
-				if (NativeMethods.SendMessageTimeout(
-					hWnd, NativeMethods.WM_COPYDATA, IntPtr.Zero, ref lParam,
-					SMTO_NORMAL, 3000, out result) != IntPtr.Zero)
-				{
-					return result;
-				}
-				else
-				{
-					return IntPtr.Zero;
-				}
-			}
-		}
-		#endregion
-
 		void Window_RequestNavigate(object sender, RequestNavigateEventArgs e)
 		{
 			ILSpy.MainWindow.Instance.NavigateTo(e);

ILSpy/MainWindow.xaml.cs

@@ -581,7 +581,7 @@ namespace ICSharpCode.ILSpy
 			{
 				hwndSource.AddHook(WndProc);
 			}
-			App.ReleaseSingleInstanceMutex();
+			SingleInstanceHandling.ReleaseSingleInstanceMutex();
 			// Validate and Set Window Bounds
 			Rect bounds = Rect.Transform(sessionSettings.WindowBounds, source.CompositionTarget.TransformToDevice);
 			var boundsRect = new System.Drawing.Rectangle((int)bounds.Left, (int)bounds.Top, (int)bounds.Width, (int)bounds.Height);

ILSpy/SingleInstanceHandling.cs

@@ -0,0 +1,154 @@
+// Copyright (c) 2022 AlphaSierraPapa for the SharpDevelop Team
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Threading;
+
+namespace ICSharpCode.ILSpy
+{
+	internal static class SingleInstanceHandling
+	{
+		internal static Mutex SingleInstanceMutex;
+
+		internal static void ForceSingleInstance(IEnumerable<string> cmdArgs)
+		{
+			bool isFirst;
+			try
+			{
+				SingleInstanceMutex = new Mutex(initiallyOwned: true, @"Local\ILSpyInstance", out isFirst);
+			}
+			catch (WaitHandleCannotBeOpenedException)
+			{
+				isFirst = true;
+			}
+			if (!isFirst)
+			{
+				try
+				{
+					SingleInstanceMutex.WaitOne(10000);
+				}
+				catch (AbandonedMutexException)
+				{
+					// continue, there is no concurrent start happening.
+				}
+			}
+			cmdArgs = cmdArgs.Select(FullyQualifyPath);
+			string message = string.Join(Environment.NewLine, cmdArgs);
+			if (SendToPreviousInstance("ILSpy:\r\n" + message, !App.CommandLineArguments.NoActivate))
+			{
+				ReleaseSingleInstanceMutex();
+				Environment.Exit(0);
+			}
+		}
+
+		internal static string FullyQualifyPath(string argument)
+		{
+			// Fully qualify the paths before passing them to another process,
+			// because that process might use a different current directory.
+			if (string.IsNullOrEmpty(argument) || argument[0] == '/')
+				return argument;
+			try
+			{
+				return Path.Combine(Environment.CurrentDirectory, argument);
+			}
+			catch (ArgumentException)
+			{
+				return argument;
+			}
+		}
+
+		internal static void ReleaseSingleInstanceMutex()
+		{
+			var mutex = SingleInstanceMutex;
+			SingleInstanceMutex = null;
+			if (mutex == null)
+			{
+				return;
+			}
+			using (mutex)
+			{
+				mutex.ReleaseMutex();
+			}
+		}
+
+		#region Pass Command Line Arguments to previous instance
+		internal static bool SendToPreviousInstance(string message, bool activate)
+		{
+			string ownProcessName;
+			using (var ownProcess = Process.GetCurrentProcess())
+			{
+				ownProcessName = ownProcess.ProcessName;
+			}
+
+			bool success = false;
+			NativeMethods.EnumWindows(
+				(hWnd, lParam) => {
+					string windowTitle = NativeMethods.GetWindowText(hWnd, 100);
+					if (windowTitle.StartsWith("ILSpy", StringComparison.Ordinal))
+					{
+						string processName = NativeMethods.GetProcessNameFromWindow(hWnd);
+						Debug.WriteLine("Found {0:x4}: '{1}' in '{2}'", hWnd, windowTitle, processName);
+						if (string.Equals(processName, ownProcessName, StringComparison.OrdinalIgnoreCase))
+						{
+							IntPtr result = Send(hWnd, message);
+							Debug.WriteLine("WM_COPYDATA result: {0:x8}", result);
+							if (result == (IntPtr)1)
+							{
+								if (activate)
+									NativeMethods.SetForegroundWindow(hWnd);
+								success = true;
+								return false; // stop enumeration
+							}
+						}
+					}
+					return true; // continue enumeration
+				}, IntPtr.Zero);
+			return success;
+		}
+
+		unsafe static IntPtr Send(IntPtr hWnd, string message)
+		{
+			const uint SMTO_NORMAL = 0;
+
+			CopyDataStruct lParam;
+			lParam.Padding = IntPtr.Zero;
+			lParam.Size = message.Length * 2;
+			fixed (char* buffer = message)
+			{
+				lParam.Buffer = (IntPtr)buffer;
+				IntPtr result;
+				// SendMessage with 3s timeout (e.g. when the target process is stopped in the debugger)
+				if (NativeMethods.SendMessageTimeout(
+					hWnd, NativeMethods.WM_COPYDATA, IntPtr.Zero, ref lParam,
+					SMTO_NORMAL, 3000, out result) != IntPtr.Zero)
+				{
+					return result;
+				}
+				else
+				{
+					return IntPtr.Zero;
+				}
+			}
+		}
+		#endregion
+	}
+}