Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Runtime.Caching/System/Caching/SqlChangeMonitor.cs

@@ -0,0 +1,41 @@
+// <copyright file="SqlChangeMonitor.cs" company="Microsoft">
+//   Copyright (c) 2009 Microsoft Corporation.  All rights reserved.
+// </copyright>
+using System;
+using System.Data.SqlClient;
+using System.Globalization;
+namespace System.Runtime.Caching {
+    public sealed class SqlChangeMonitor : ChangeMonitor {
+        private String _uniqueId;
+        private SqlDependency _sqlDependency;
+ 
+        public override String UniqueId { get { return _uniqueId; } }
+ 
+        private SqlChangeMonitor() {} // hide default .ctor
+ 
+        public SqlChangeMonitor(SqlDependency dependency) {
+            if (dependency == null) {
+                throw new ArgumentNullException("dependency");
+            }
+            bool dispose = true;
+            try {
+                _sqlDependency = dependency;
+                _sqlDependency.OnChange += new OnChangeEventHandler(OnDependencyChanged);
+                _uniqueId = Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
+                dispose = false;
+            }
+            finally {
+                InitializationComplete();
+                if (dispose) {
+                    Dispose();
+                }
+            }
+        }
+ 
+        protected override void Dispose(bool disposing) {}
+ 
+        private void OnDependencyChanged(Object sender, SqlNotificationEventArgs e) {
+            OnChanged(null);
+        }
+    }
+}