initial commit

Quasar.Client/Utilities/SingleInstanceMutex.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Threading;
+
+namespace Quasar.Client.Utilities
+{
+    /// <summary>
+    /// A user-wide mutex that ensures that only one instance runs at a time.
+    /// </summary>
+    public class SingleInstanceMutex : IDisposable
+    {
+        /// <summary>
+        /// The mutex used for process synchronization.
+        /// </summary>
+        private readonly Mutex _appMutex;
+
+        /// <summary>
+        /// Represents if the mutex was created on the system or it already existed.
+        /// </summary>
+        public bool CreatedNew { get; }
+
+        /// <summary>
+        /// Determines if the instance is disposed and should not be used anymore.
+        /// </summary>
+        public bool IsDisposed { get; private set; }
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="SingleInstanceMutex"/> using the given mutex name.
+        /// </summary>
+        /// <param name="name">The name of the mutex.</param>
+        public SingleInstanceMutex(string name)
+        {
+            _appMutex = new Mutex(false, $"Local\\{name}", out var createdNew);
+            CreatedNew = createdNew;
+        }
+
+        /// <summary>
+        /// Releases all resources used by this <see cref="SingleInstanceMutex"/>.
+        /// </summary>
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        /// <summary>
+        /// Releases the mutex object.
+        /// </summary>
+        /// <param name="disposing"><c>True</c> if called from <see cref="Dispose"/>, <c>false</c> if called from the finalizer.</param>
+        protected virtual void Dispose(bool disposing)
+        {
+            if (IsDisposed)
+                return;
+
+            if (disposing)
+            {
+                _appMutex?.Dispose();
+            }
+
+            IsDisposed = true;
+        }
+    }
+}