Imported Upstream version 4.3.2.467

Former-commit-id: 9c2cb47f45fa221e661ab616387c9cda183f283d
2016-02-22 11:00:01 -05:00
parent f302175246
commit f3e3aab35a
4097 changed files with 122406 additions and 82300 deletions
--- a/external/referencesource/mscorlib/system/AppContext/AppContextSwitches.cs
+++ b/external/referencesource/mscorlib/system/AppContext/AppContextSwitches.cs
@@ -0,0 +1,82 @@
+// ==++==
+// 
+//   Copyright (c) Microsoft Corporation.  All rights reserved.
+// 
+// ==--==
+
+namespace System
+{
+    using System;
+    using System.Runtime.CompilerServices;
+
+    internal static class AppContextSwitches
+    {
+        private static int _noAsyncCurrentCulture;
+        public static bool NoAsyncCurrentCulture
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                return GetCachedSwitchValue(AppContextDefaultValues.SwitchNoAsyncCurrentCulture, ref _noAsyncCurrentCulture);
+            }
+        }
+
+        private static int _throwExceptionIfDisposedCancellationTokenSource;
+        public static bool ThrowExceptionIfDisposedCancellationTokenSource
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                return GetCachedSwitchValue(AppContextDefaultValues.SwitchThrowExceptionIfDisposedCancellationTokenSource, ref _throwExceptionIfDisposedCancellationTokenSource);
+            }
+        }
+
+        private static int _preserveEventListnerObjectIdentity;
+        public static bool PreserveEventListnerObjectIdentity
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                return GetCachedSwitchValue(AppContextDefaultValues.SwitchPreserveEventListnerObjectIdentity, ref _preserveEventListnerObjectIdentity);
+            }
+        }
+
+        //
+        // Implementation details
+        //
+
+        private static bool DisableCaching { get; set; }
+
+        static AppContextSwitches()
+        {
+            bool isEnabled;
+            if (AppContext.TryGetSwitch(@"TestSwitch.LocalAppContext.DisableCaching", out isEnabled))
+            {
+                DisableCaching = isEnabled;
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal static bool GetCachedSwitchValue(string switchName, ref int switchValue)
+        {
+            if (switchValue < 0) return false;
+            if (switchValue > 0) return true;
+
+            return GetCachedSwitchValueInternal(switchName, ref switchValue);
+        }
+
+        private static bool GetCachedSwitchValueInternal(string switchName, ref int switchValue)
+        {
+            bool isSwitchEnabled;
+            AppContext.TryGetSwitch(switchName, out isSwitchEnabled);
+
+            if (DisableCaching)
+            {
+                return isSwitchEnabled;
+            }
+
+            switchValue = isSwitchEnabled ? 1 /*true*/ : -1 /*false*/;
+            return isSwitchEnabled;
+        }
+    }
+}