Imported Upstream version 2.0.0.11353upstream/2.0.0.11353

1 files changed, 23 insertions, 0 deletions

diff --git a/src/mscorlib/shared/Interop/Windows/Kernel32/Interop.WriteFile_SafeHandle_IntPtr.cs b/src/mscorlib/shared/Interop/Windows/Kernel32/Interop.WriteFile_SafeHandle_IntPtr.cs
new file mode 100644
index 0000000000..69651ca1ca
--- /dev/null
+++ b/src/mscorlib/shared/Interop/Windows/Kernel32/Interop.WriteFile_SafeHandle_IntPtr.cs
@@ -0,0 +1,23 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.Win32.SafeHandles;
+using System;
+using System.Runtime.InteropServices;
+
+internal partial class Interop
+{
+    internal partial class Kernel32
+    {
+        // Note there are two different WriteFile prototypes - this is to use 
+        // the type system to force you to not trip across a "feature" in 
+        // Win32's async IO support.  You can't do the following three things
+        // simultaneously: overlapped IO, free the memory for the overlapped 
+        // struct in a callback (or an EndWrite method called by that callback),
+        // and pass in an address for the numBytesRead parameter.
+
+        [DllImport(Libraries.Kernel32, SetLastError = true)]
+        internal static extern unsafe int WriteFile(SafeHandle handle, byte* bytes, int numBytesToWrite, out int numBytesWritten, IntPtr mustBeZero);
+    }
+}