Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/OSEnvironmentHelper.cs

@@ -0,0 +1,109 @@
+//----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//----------------------------------------------------------------------------
+
+namespace System.ServiceModel
+{
+    using System.Runtime;
+
+    static class OSEnvironmentHelper
+    {        
+        private static readonly OSVersion currentVersion;
+        private static readonly byte currentServicePack;
+
+        static OSEnvironmentHelper()
+        {
+            currentServicePack = (byte)Environment.OSVersion.Version.MajorRevision;
+
+            int major = Environment.OSVersion.Version.Major;
+            int minor = Environment.OSVersion.Version.Minor;
+
+            if ((major < 5) || ((major == 5) && (minor == 0)))
+            {
+                currentVersion = OSVersion.PreWinXP;
+            }
+            if ((major == 5) && (minor == 1))
+            {
+                currentVersion = OSVersion.WinXP;
+            }
+            else if ((major == 5) && (minor == 2))
+            {
+                currentVersion = OSVersion.Win2003;
+            }
+            else if ((major == 6) && (minor == 0))
+            {
+                currentVersion = OSVersion.WinVista;
+            }
+            else if ((major == 6) && (minor == 1))
+            {
+                currentVersion = OSVersion.Win7;
+            }
+            else if ((major == 6) && (minor == 2))
+            {
+                currentVersion = OSVersion.Win8;
+            }
+            else if ((major > 6) ||
+                    ((major == 6) && (minor > 2)))
+            {
+                currentVersion = OSVersion.PostWin8;
+            }
+            else
+            {
+                // This should only be possible if major == 5 and minor > 2
+                Fx.Assert(false, "Unknown OS");
+                currentVersion = OSVersion.Unknown;
+            }
+
+        }
+
+        internal static bool IsVistaOrGreater
+        {
+            get
+            {
+                return IsAtLeast(OSVersion.WinVista);
+            }
+        }
+
+        internal static bool IsApplicationTargeting45
+        {
+            get
+            {
+#pragma warning disable 0618
+                return System.Net.WebSockets.WebSocket.IsApplicationTargeting45();
+#pragma warning restore 0618
+            }
+        }
+
+
+        internal static int ProcessorCount
+        {
+            get
+            {
+                return Environment.ProcessorCount;
+            }
+        }
+
+        internal static bool IsAtLeast(OSVersion version)
+        {
+            return IsAtLeast(version, 0);
+        }
+
+        static bool IsAtLeast(OSVersion version, byte servicePack)
+        {
+            Fx.Assert(version != OSVersion.Unknown, "Unknown OS");
+
+            if (servicePack == 0)
+            {
+                return version <= currentVersion;
+            }
+
+            // If a SP value is provided and we have the same OS version, compare SP values
+            if (version == currentVersion)
+            {
+                return servicePack <= currentServicePack;
+            }
+
+            return version < currentVersion;
+        }
+    }
+}