first commit

LibreHardwareMonitor-0.9.4/LibreHardwareMonitorLib/Hardware/ThreadAffinity.cs

@@ -0,0 +1,69 @@
+// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
+// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+// Copyright (C) LibreHardwareMonitor and Contributors.
+// Partial Copyright (C) Michael Möller <mmoeller@openhardwaremonitor.org> and Contributors.
+// All Rights Reserved.
+
+using System;
+using LibreHardwareMonitor.Interop;
+
+namespace LibreHardwareMonitor.Hardware;
+
+internal static class ThreadAffinity
+{
+    /// <summary>
+    /// Initializes static members of the <see cref="ThreadAffinity" /> class.
+    /// </summary>
+    static ThreadAffinity()
+    {
+        ProcessorGroupCount = Software.OperatingSystem.IsUnix ? 1 : Kernel32.GetActiveProcessorGroupCount();
+
+        if (ProcessorGroupCount < 1)
+            ProcessorGroupCount = 1;
+    }
+
+    /// <summary>
+    /// Gets the processor group count.
+    /// </summary>
+    public static int ProcessorGroupCount { get; }
+
+    /// <summary>
+    /// Sets the processor group affinity for the current thread.
+    /// </summary>
+    /// <param name="affinity">The processor group affinity.</param>
+    /// <returns>The previous processor group affinity.</returns>
+    public static GroupAffinity Set(GroupAffinity affinity)
+    {
+        if (affinity == GroupAffinity.Undefined)
+            return GroupAffinity.Undefined;
+
+        if (Software.OperatingSystem.IsUnix)
+        {
+            if (affinity.Group > 0)
+                throw new ArgumentOutOfRangeException(nameof(affinity));
+
+            ulong result = 0;
+            if (LibC.sched_getaffinity(0, (IntPtr)8, ref result) != 0)
+                return GroupAffinity.Undefined;
+
+            ulong mask = affinity.Mask;
+            return LibC.sched_setaffinity(0, (IntPtr)8, ref mask) != 0
+                ? GroupAffinity.Undefined
+                : new GroupAffinity(0, result);
+        }
+
+        ulong maxValue = IntPtr.Size == 8 ? ulong.MaxValue : uint.MaxValue;
+        if (affinity.Mask > maxValue)
+            throw new ArgumentOutOfRangeException(nameof(affinity));
+
+        var groupAffinity = new Kernel32.GROUP_AFFINITY { Group = affinity.Group, Mask = (UIntPtr)affinity.Mask };
+
+        IntPtr currentThread = Kernel32.GetCurrentThread();
+
+        return Kernel32.SetThreadGroupAffinity(currentThread,
+                                               ref groupAffinity,
+                                               out Kernel32.GROUP_AFFINITY previousGroupAffinity)
+            ? new GroupAffinity(previousGroupAffinity.Group, (ulong)previousGroupAffinity.Mask)
+            : GroupAffinity.Undefined;
+    }
+}