From f11b28372597c20643d9a6494f7a7bb1f35c539e Mon Sep 17 00:00:00 2001
From: Ian Hays <ianha@microsoft.com>
Date: Thu, 30 Jun 2016 11:16:33 -0700
Subject: [PATCH] Add locks to WinRT Console Color functions

Commit migrated from https://github.com/dotnet/corefx/commit/a09e463dbe562603417b45855efdab55023eb2d3
---
 src/libraries/System.Console/src/System/Console.cs |  2 ++
 .../System.Console/src/System/ConsolePal.Unix.cs   | 15 ++++-----
 .../System.Console/src/System/ConsolePal.WinRT.cs  | 38 +++++++++++++++++-----
 3 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/src/libraries/System.Console/src/System/Console.cs b/src/libraries/System.Console/src/System/Console.cs
index 59149252..8b023a1 100644
--- a/src/libraries/System.Console/src/System/Console.cs
+++ b/src/libraries/System.Console/src/System/Console.cs
@@ -193,6 +193,8 @@ namespace System
 
         public static bool CapsLock { get { return ConsolePal.CapsLock; } }
 
+        internal const ConsoleColor UnknownColor = (ConsoleColor)(-1);
+
         public static ConsoleColor BackgroundColor
         {
             get { return ConsolePal.BackgroundColor; }
diff --git a/src/libraries/System.Console/src/System/ConsolePal.Unix.cs b/src/libraries/System.Console/src/System/ConsolePal.Unix.cs
index 994610b..acf288a 100644
--- a/src/libraries/System.Console/src/System/ConsolePal.Unix.cs
+++ b/src/libraries/System.Console/src/System/ConsolePal.Unix.cs
@@ -125,9 +125,8 @@ namespace System
             }
         }
 
-        private const ConsoleColor UnknownColor = (ConsoleColor)(-1);
-        private static ConsoleColor s_trackedForegroundColor = UnknownColor;
-        private static ConsoleColor s_trackedBackgroundColor = UnknownColor;
+        private static ConsoleColor s_trackedForegroundColor = Console.UnknownColor;
+        private static ConsoleColor s_trackedBackgroundColor = Console.UnknownColor;
 
         public static ConsoleColor ForegroundColor
         {
@@ -145,8 +144,8 @@ namespace System
         {
             lock (Console.Out) // synchronize with other writers
             {
-                s_trackedForegroundColor = UnknownColor;
-                s_trackedBackgroundColor = UnknownColor;
+                s_trackedForegroundColor = Console.UnknownColor;
+                s_trackedBackgroundColor = Console.UnknownColor;
                 WriteResetColorString();
             }
         }
@@ -504,7 +503,7 @@ namespace System
         /// </summary>
         private static void RefreshColors(ref ConsoleColor toChange, ConsoleColor value)
         {
-            if (((int)value & ~0xF) != 0 && value != UnknownColor)
+            if (((int)value & ~0xF) != 0 && value != Console.UnknownColor)
             {
                 throw new ArgumentException(SR.Arg_InvalidConsoleColor);
             }
@@ -515,12 +514,12 @@ namespace System
 
                 WriteResetColorString();
 
-                if (s_trackedForegroundColor != UnknownColor)
+                if (s_trackedForegroundColor != Console.UnknownColor)
                 {
                     WriteSetColorString(foreground: true, color: s_trackedForegroundColor);
                 }
 
-                if (s_trackedBackgroundColor != UnknownColor)
+                if (s_trackedBackgroundColor != Console.UnknownColor)
                 {
                     WriteSetColorString(foreground: false, color: s_trackedBackgroundColor);
                 }
diff --git a/src/libraries/System.Console/src/System/ConsolePal.WinRT.cs b/src/libraries/System.Console/src/System/ConsolePal.WinRT.cs
index 4853d07..a1558d0 100644
--- a/src/libraries/System.Console/src/System/ConsolePal.WinRT.cs
+++ b/src/libraries/System.Console/src/System/ConsolePal.WinRT.cs
@@ -82,26 +82,46 @@ namespace System
             set { throw new PlatformNotSupportedException(); }
         }
 
-        private const ConsoleColor UnknownColor = (ConsoleColor)(-1);
-        private static ConsoleColor s_trackedForegroundColor = UnknownColor;
-        private static ConsoleColor s_trackedBackgroundColor = UnknownColor;
+        private static ConsoleColor s_trackedForegroundColor = Console.UnknownColor;
+        private static ConsoleColor s_trackedBackgroundColor = Console.UnknownColor;
 
         public static ConsoleColor ForegroundColor
         {
-            get { return s_trackedForegroundColor; }
-            set { s_trackedForegroundColor = value; }
+            get
+            {
+                return s_trackedForegroundColor;
+            }
+            set
+            {
+                lock (Console.Out) // synchronize with other writers
+                {
+                    s_trackedForegroundColor = value;
+                }
+            }
         }
 
         public static ConsoleColor BackgroundColor
         {
-            get { return s_trackedBackgroundColor; }
-            set { s_trackedBackgroundColor = value; }
+            get
+            {
+                return s_trackedBackgroundColor;
+            }
+            set
+            {
+                lock (Console.Out) // synchronize with other writers
+                {
+                    s_trackedBackgroundColor = value;
+                }
+            }
         }
 
         public static void ResetColor()
         {
-            s_trackedForegroundColor = UnknownColor;
-            s_trackedBackgroundColor = UnknownColor;
+            lock (Console.Out) // synchronize with other writers
+            {
+                s_trackedForegroundColor = Console.UnknownColor;
+                s_trackedBackgroundColor = Console.UnknownColor;
+            }
         }
 
         public static bool NumberLock { get { throw new PlatformNotSupportedException(); } }
-- 
2.7.4