1 files changed, 21 insertions, 0 deletions
diff --git a/src/mscorlib/corefx/Interop/Unix/System.Native/Interop.Fcntl.cs b/src/mscorlib/corefx/Interop/Unix/System.Native/Interop.Fcntl.cs
new file mode 100644
index 0000000000..23b48a4f5d
--- /dev/null
+++ b/src/mscorlib/corefx/Interop/Unix/System.Native/Interop.Fcntl.cs
@@ -0,0 +1,21 @@
+// 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 System;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class Sys
+    {
+        internal enum LockType : short
+        {
+            F_WRLCK = 1,    // exclusive or write lock
+            F_UNLCK = 2     // unlock
+        }
+        
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_LockFileRegion", SetLastError=true)]
+        internal static extern int LockFileRegion(SafeHandle fd, long offset, long length, LockType lockType);
+    }
+}