Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/rx/Rx/NET/Source/Tests.System.Reactive/DispatcherHelpers.cs

@@ -0,0 +1,71 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+#if !NO_WINDOWS_THREADING
+using System;
+using System.Threading;
+using System.Windows.Threading;
+
+namespace ReactiveTests
+{
+    static class DispatcherHelpers
+    {
+        public static DispatcherWrapper EnsureDispatcher()
+        {
+#if DESKTOPCLR
+            var dispatcher = new Thread(Dispatcher.Run);
+            dispatcher.IsBackground = true;
+            dispatcher.Start();
+
+            while (Dispatcher.FromThread(dispatcher) == null)
+                Thread.Sleep(10);
+
+            var d = Dispatcher.FromThread(dispatcher);
+
+            while (d.BeginInvoke(new Action(() => { })).Status == DispatcherOperationStatus.Aborted) ;
+
+            return new DispatcherWrapper(d);
+#else
+            return new DispatcherWrapper(System.Windows.Deployment.Current.Dispatcher);
+#endif
+        }
+    }
+
+    class DispatcherWrapper
+    {
+        private Dispatcher _dispatcher;
+
+        public DispatcherWrapper(Dispatcher dispatcher)
+        {
+            _dispatcher = dispatcher;
+        }
+
+        public Dispatcher Dispatcher { get { return _dispatcher; } }
+
+        public void InvokeShutdown()
+        {
+#if !USE_SL_DISPATCHER
+            _dispatcher.InvokeShutdown();
+#endif
+        }
+
+        public static implicit operator Dispatcher(DispatcherWrapper wrapper)
+        {
+            return wrapper._dispatcher;
+        }
+
+#if !USE_SL_DISPATCHER
+        public event DispatcherUnhandledExceptionEventHandler UnhandledException
+        {
+            add { _dispatcher.UnhandledException += value; }
+            remove { _dispatcher.UnhandledException -= value; }
+        }
+#endif
+
+        public void BeginInvoke(Action action)
+        {
+            _dispatcher.BeginInvoke(action);
+        }
+    }
+}
+
+#endif