Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Web/Util/ISyncContext.cs

@@ -0,0 +1,23 @@
+//------------------------------------------------------------------------------
+// <copyright file="ISyncContext.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.Util {
+    using System;
+
+    // Used to perform some pre-processing that needs to take place around a callback
+    // in order to set up the appropriate synchronization primitives.
+
+    internal interface ISyncContext {
+
+        // Used by AppVerifier to make sure we're not trying to use a freed request.
+        // This property getter must never throw but may return null if the context
+        // has been freed or the request has finished.
+        HttpContext HttpContext { get; }
+
+        ISyncContextLock Enter();
+
+    }
+}