Imported Upstream version 1.0.0.9127upstream/1.0.0.9127

1 files changed, 28 insertions, 0 deletions

diff --git a/src/mscorlib/corefx/System/Buffers/TlsOverPerCoreLockedStacksArrayPool.Unix.cs b/src/mscorlib/corefx/System/Buffers/TlsOverPerCoreLockedStacksArrayPool.Unix.cs
new file mode 100644
index 0000000000..8a1d006b12
--- /dev/null
+++ b/src/mscorlib/corefx/System/Buffers/TlsOverPerCoreLockedStacksArrayPool.Unix.cs
@@ -0,0 +1,28 @@
+// 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 Microsoft.Win32;
+using System.Runtime.CompilerServices;
+
+namespace System.Buffers
+{
+    internal sealed partial class TlsOverPerCoreLockedStacksArrayPool<T>
+    {
+        /// <summary>Get an identifier for the current thread to use to index into the stacks.</summary>
+        private static int ExecutionId
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                // On Unix, CurrentProcessorNumber is implemented in terms of sched_getcpu, which
+                // doesn't exist on all platforms.  On those it doesn't exist on, GetCurrentProcessorNumber
+                // returns -1.  As a fallback in that case and to spread the threads across the buckets
+                // by default, we use the current managed thread ID as a proxy.
+                int id = CurrentProcessorNumber;
+                if (id < 0) id = Environment.CurrentManagedThreadId;
+                return id;
+            }
+        }
+    }
+}