Data commit

Task/Determine-if-only-one-instance-is-running/C-sharp/determine-if-only-one-instance-is-running-1.cs

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+using System;
+using System.Net;
+using System.Net.Sockets;
+
+class Program {
+    static void Main(string[] args) {
+        try {
+            TcpListener server = new TcpListener(IPAddress.Any, 12345);
+            server.Start();
+        }
+
+        catch (SocketException e) {
+            if (e.SocketErrorCode == SocketError.AddressAlreadyInUse) {
+                Console.Error.WriteLine("Already running.");
+            }
+        }
+    }
+}

Task/Determine-if-only-one-instance-is-running/C-sharp/determine-if-only-one-instance-is-running-2.cs

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+// Use this class in your process to guard against multiple instances
+//
+// This is valid for C# running on Windows, but not for C# with Linux.
+//
+using System;
+using System.Threading;
+
+/// <summary>
+/// RunOnce should be instantiated in the calling processes main clause
+/// (preferably using a "using" clause) and then calling process
+/// should then check AlreadyRunning and do whatever is appropriate
+/// </summary>
+public class RunOnce : IDisposable
+{
+	public RunOnce( string name )
+	{
+		m_name = name;
+		AlreadyRunning = false;
+
+		bool created_new = false;
+
+		m_mutex = new Mutex( false, m_name, out created_new );
+
+		AlreadyRunning = !created_new;
+	}
+
+	~RunOnce()
+	{
+		DisposeImpl( false );
+	}
+
+	public bool AlreadyRunning
+	{
+		get { return m_already_running; }
+		private set { m_already_running = value; }
+	}
+
+	private void DisposeImpl( bool is_disposing )
+	{
+		GC.SuppressFinalize( this );
+
+		if( is_disposing )
+		{
+			m_mutex.Close();
+		}
+	}
+
+	#region IDisposable Members
+
+	public void Dispose()
+	{
+		DisposeImpl( true );
+	}
+
+	#endregion
+
+	private string m_name;
+	private bool m_already_running;
+	private Mutex m_mutex;
+}
+
+class Program
+{
+    // Example code to use this
+    static void Main( string[] args )
+    {
+        using ( RunOnce ro = new RunOnce( "App Name" ) )
+        {
+            if ( ro.AlreadyRunning )
+            {
+                Console.WriteLine( "Already running" );
+                return;
+            }
+
+            // Program logic
+        }
+    }
+}