From 233c58ca964e15e6ce1e756940ec59819d797edf Mon Sep 17 00:00:00 2001
From: Ian Hays <ianha@microsoft.com>
Date: Thu, 17 Nov 2016 15:36:31 -0800
Subject: [PATCH] Add Unix FileStream Lock/Unlock

Implements FileStream Lock/Unlock by calling the SystemNative functions for fcntl F_SETLK
---
 .../corefx/Interop/Unix/System.Native/Interop.Fcntl.cs | 18 ++++++++++++++++++
 src/mscorlib/corefx/System/IO/FileStream.Unix.cs       |  6 ++----
 src/mscorlib/mscorlib.shared.sources.props             |  1 +
 3 files changed, 21 insertions(+), 4 deletions(-)
 create mode 100644 src/mscorlib/corefx/Interop/Unix/System.Native/Interop.Fcntl.cs

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 0000000..1dc003b
--- /dev/null
+++ b/src/mscorlib/corefx/Interop/Unix/System.Native/Interop.Fcntl.cs
@@ -0,0 +1,18 @@
+// 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
+    {
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_LockFileRegion", SetLastError=true)]
+        internal static extern int LockFileRegion(SafeHandle fd, long offset, long length);
+        
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_UnlockFileRegion", SetLastError=true)]
+        internal static extern int UnlockFileRegion(SafeHandle fd, long offset, long length);
+    }
+}
diff --git a/src/mscorlib/corefx/System/IO/FileStream.Unix.cs b/src/mscorlib/corefx/System/IO/FileStream.Unix.cs
index ece1923..f11f97c 100644
--- a/src/mscorlib/corefx/System/IO/FileStream.Unix.cs
+++ b/src/mscorlib/corefx/System/IO/FileStream.Unix.cs
@@ -801,8 +801,7 @@ namespace System.IO
         /// <param name="length">The range to be locked.</param>
         private void LockInternal(long position, long length)
         {
-            // TODO #5964: Implement this with fcntl and F_SETLK in System.Native
-            throw new PlatformNotSupportedException();
+            CheckFileCall(Interop.Sys.LockFileRegion(_fileHandle, position, length));
         }
 
         /// <summary>Allows access by other processes to all or part of a file that was previously locked.</summary>
@@ -810,8 +809,7 @@ namespace System.IO
         /// <param name="length">The range to be unlocked.</param>
         private void UnlockInternal(long position, long length)
         {
-            // TODO #5964: Implement this with fcntl and F_SETLK in System.Native
-            throw new PlatformNotSupportedException();
+            CheckFileCall(Interop.Sys.UnlockFileRegion(_fileHandle, position, length));
         }
 
         /// <summary>Sets the current position of this stream to the given value.</summary>
diff --git a/src/mscorlib/mscorlib.shared.sources.props b/src/mscorlib/mscorlib.shared.sources.props
index 2fdfa01..98fee90 100644
--- a/src/mscorlib/mscorlib.shared.sources.props
+++ b/src/mscorlib/mscorlib.shared.sources.props
@@ -1250,6 +1250,7 @@
     <UnixInteropSources Include="$(CoreFxSourcesRoot)\Interop\Unix\System.Native\Interop.Close.cs" />
     <UnixInteropSources Include="$(CoreFxSourcesRoot)\Interop\Unix\System.Native\Interop.GetCwd.cs" />
     <UnixInteropSources Include="$(CoreFxSourcesRoot)\Interop\Unix\System.Native\Interop.GetUnixName.cs" />
+    <UnixInteropSources Include="$(CoreFxSourcesRoot)\Interop\Unix\System.Native\Interop.Fcntl.cs" />
     <UnixInteropSources Include="$(CoreFxSourcesRoot)\Interop\Unix\System.Native\Interop.FLock.cs" />
     <UnixInteropSources Include="$(CoreFxSourcesRoot)\Interop\Unix\System.Native\Interop.FSync.cs" />
     <UnixInteropSources Include="$(CoreFxSourcesRoot)\Interop\Unix\System.Native\Interop.FTruncate.cs" />
-- 
2.7.4