Imported Upstream version 4.3.2.467

Former-commit-id: 9c2cb47f45fa221e661ab616387c9cda183f283d

mcs/class/corlib/coreclr/WaitHandleExtensions.cs

@@ -0,0 +1,45 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+//
+
+using Microsoft.Win32.SafeHandles;
+using System.Security;
+
+namespace System.Threading
+{
+    public static class WaitHandleExtensions
+    {
+        /// <summary>
+        /// Gets the native operating system handle.
+        /// </summary>
+        /// <param name="waitHandle">The <see cref="System.Threading.WaitHandle"/> to operate on.</param>
+        /// <returns>A <see cref="System.Runtime.InteropServices.SafeHandle"/> representing the native operating system handle.</returns>
+        [SecurityCritical]
+        public static SafeWaitHandle GetSafeWaitHandle(this WaitHandle waitHandle)
+        {
+            if (waitHandle == null)
+            {
+                throw new ArgumentNullException("waitHandle");
+            }
+
+            return waitHandle.SafeWaitHandle;
+        }
+
+        /// <summary>
+        /// Sets the native operating system handle
+        /// </summary>
+        /// <param name="waitHandle">The <see cref="System.Threading.WaitHandle"/> to operate on.</param>
+        /// <param name="value">A <see cref="System.Runtime.InteropServices.SafeHandle"/> representing the native operating system handle.</param>
+        [SecurityCritical]
+        public static void SetSafeWaitHandle(this WaitHandle waitHandle, SafeWaitHandle value)
+        {
+            if (waitHandle == null)
+            {
+                throw new ArgumentNullException("waitHandle");
+            }
+
+            waitHandle.SafeWaitHandle = value;
+        }
+    }
+}