[2020-02][System.Native] Handle ReadDir EINTR (#21029)mono-6.12.0.140

* [System.Native] Handle ReadDir EINTR

Handle EINTR for opendir/readdir/closedir.

Because of how thread aborts work, we must loop in managed.
A thread abort will break syscalls and return EINTR, but mono will not raise a
ThreadAbortException until a pinvoke returns.

(Despite the documentation, opendir/readdir/closedir sometimes return EINTR on
macOS Big Sur.)

Related to https://github.com/mono/mono/issues/20799

* bump corefx

* [System] on unix, include Interop.ReadDir.Mono.cs

on mac it's in corlib, on unix and android it's in System, for some reason

* Add newline

Co-authored-by: Alexander Köplinger <alex.koeplinger@outlook.com>

6 files changed, 51 insertions, 0 deletions

diff --git a/external/corefx b/external/corefx
-Subproject 38e9a9317c2cf78611506c491cf27c5fddf9828
+Subproject 9174bbeb7e1e4d3dc51f4f82243cbf4c62c61ef
diff --git a/mcs/class/System/corefx.unix.sources b/mcs/class/System/corefx.unix.sources
index a56c61a881c..1a1092ae760 100644
--- a/mcs/class/System/corefx.unix.sources
+++ b/mcs/class/System/corefx.unix.sources
@@ -1,5 +1,6 @@
 corefx/Unix/Interop.cs
 corefx/Unix/Interop.Read.cs
+
 ../../../external/corefx/src/Common/src/Interop/Unix/*.cs
 
 ../../../external/corefx/src/Common/src/Interop/Unix/System.Net.Security.Native/Interop.NetSecurityNative.cs
diff --git a/mcs/class/System/monodroid_System.dll.sources b/mcs/class/System/monodroid_System.dll.sources
index d837f60135d..706ee92f36a 100644
--- a/mcs/class/System/monodroid_System.dll.sources
+++ b/mcs/class/System/monodroid_System.dll.sources
@@ -19,3 +19,5 @@ Mono.Btls/MonoBtlsX509LookupAndroid.cs
 ../../../external/corefx/src/Common/src/Interop/Unix/System.Native/Interop.Poll.cs
 ../../../external/corefx/src/Common/src/Interop/Unix/System.Native/Interop.Open.cs
 ../../../external/corefx/src/Common/src/Interop/Unix/System.Native/Interop.Close.cs
+
+../corlib/corefx/Interop.ReadDir.Mono.cs
diff --git a/mcs/class/System/unix_net_4_x_System.dll.sources b/mcs/class/System/unix_net_4_x_System.dll.sources
index 1264e8ac0b5..a47b0ce3636 100644
--- a/mcs/class/System/unix_net_4_x_System.dll.sources
+++ b/mcs/class/System/unix_net_4_x_System.dll.sources
@@ -15,3 +15,5 @@
 ../../../external/corefx/src/Common/src/Interop/Unix/System.Native/Interop.Close.cs
 ../../../external/corefx/src/Common/src/System/Net/ContextAwareResult.Unix.cs
 Internal.Cryptography/OidLookup.Managed.cs
+
+../corlib/corefx/Interop.ReadDir.Mono.cs
diff --git a/mcs/class/corlib/corefx/Interop.ReadDir.Mono.cs b/mcs/class/corlib/corefx/Interop.ReadDir.Mono.cs
new file mode 100644
index 00000000000..b5fb5495d64
--- /dev/null
+++ b/mcs/class/corlib/corefx/Interop.ReadDir.Mono.cs
@@ -0,0 +1,45 @@
+// 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_OpenDir", SetLastError = true)]
+		internal static extern IntPtr OpenDir_native(string path);
+
+		[DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_ReadDirR", SetLastError = false)]
+		internal static extern unsafe int ReadDirR_native(IntPtr dir, byte* buffer, int bufferSize, out DirectoryEntry outputEntry);
+
+		[DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_CloseDir", SetLastError = true)]
+		internal static extern int CloseDir_native(IntPtr dir);
+
+		internal static IntPtr OpenDir (string path) {
+			IntPtr result;
+			do {
+				result = OpenDir_native (path);
+			} while (result == IntPtr.Zero && Marshal.GetLastWin32Error () == (int) Interop.Error.EINTR);
+			return result;
+		}
+
+		internal static int CloseDir (IntPtr dir) {
+			int result;
+			do {
+				result = CloseDir_native (dir);
+			} while (result < 0 && Marshal.GetLastWin32Error () == (int) Interop.Error.EINTR);
+			return result;
+		}
+
+		internal static unsafe int ReadDirR (IntPtr dir, byte* buffer, int bufferSize, out DirectoryEntry outputEntry) {
+			int result;
+			do {
+				result = ReadDirR_native (dir, buffer, bufferSize, out outputEntry);
+			} while (result == (int) Interop.Error.EINTR);
+			return result;
+		}
+	}
+}
diff --git a/mcs/class/corlib/unix_build_corlib.dll.sources b/mcs/class/corlib/unix_build_corlib.dll.sources
index a3ebc60f09c..1106989dfca 100644
--- a/mcs/class/corlib/unix_build_corlib.dll.sources
+++ b/mcs/class/corlib/unix_build_corlib.dll.sources
@@ -27,6 +27,7 @@
 ../../../external/corefx/src/Common/src/Microsoft/Win32/SafeHandles/SafeDirectoryHandle.Unix.cs
 
 corefx/DriveInfoInternal.Unix.cs
+corefx/Interop.ReadDir.Mono.cs
 
 ../../../external/corefx/src/Common/src/CoreLib/Interop/Unix/System.Native/Interop.GetRandomBytes.cs
 ../../../external/corefx/src/Common/src/CoreLib/Interop/Unix/System.Native/Interop.ReadDir.cs