Pushing missing changes

MediaBrowser.Common/Extensions/NamedLock.cs

@@ -0,0 +1,97 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Common.Extensions
+{
+    /// <summary>
+    /// Class NamedLock
+    /// </summary>
+    public class NamedLock : IDisposable
+    {
+        /// <summary>
+        /// The _locks
+        /// </summary>
+        private readonly Dictionary<string, SemaphoreSlim> _locks = new Dictionary<string, SemaphoreSlim>();
+
+        /// <summary>
+        /// Waits the async.
+        /// </summary>
+        /// <param name="name">The name.</param>
+        /// <returns>Task.</returns>
+        public Task WaitAsync(string name)
+        {
+            return GetLock(name).WaitAsync();
+        }
+
+        /// <summary>
+        /// Releases the specified name.
+        /// </summary>
+        /// <param name="name">The name.</param>
+        public void Release(string name)
+        {
+            SemaphoreSlim semaphore;
+
+            if (_locks.TryGetValue(name, out semaphore))
+            {
+                semaphore.Release();
+            }
+        }
+
+        /// <summary>
+        /// Gets the lock.
+        /// </summary>
+        /// <param name="filename">The filename.</param>
+        /// <returns>System.Object.</returns>
+        private SemaphoreSlim GetLock(string filename)
+        {
+            SemaphoreSlim fileLock;
+            lock (_locks)
+            {
+                if (!_locks.TryGetValue(filename, out fileLock))
+                {
+                    fileLock = new SemaphoreSlim(1,1);
+                    _locks[filename] = fileLock;
+                }
+            }
+            return fileLock;
+        }
+
+        /// <summary>
+        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+        /// </summary>
+        public void Dispose()
+        {
+            Dispose(true);
+        }
+
+        /// <summary>
+        /// Releases unmanaged and - optionally - managed resources.
+        /// </summary>
+        /// <param name="dispose"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
+        protected virtual void Dispose(bool dispose)
+        {
+            if (dispose)
+            {
+                DisposeLocks();
+            }
+        }
+
+        /// <summary>
+        /// Disposes the locks.
+        /// </summary>
+        private void DisposeLocks()
+        {
+            lock (_locks)
+            {
+                foreach (var semaphore in _locks.Values)
+                {
+                    semaphore.Dispose();
+                }
+
+                _locks.Clear();
+            }
+        }
+    }
+}