Initial commit

srcs/RobotNet10/Commons/RobotNet10.Realtime/CpuAffinity.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace RobotNet10.Realtime;
+
+/// <summary>
+/// Provides CPU affinity management for Linux real-time applications.
+/// </summary>
+public class CpuAffinity : IDisposable
+{
+    private LinuxNative.cpu_set_t _cpuSet;
+    private bool _disposed = false;
+
+    /// <summary>
+    /// Initializes a new instance of CpuAffinity.
+    /// </summary>
+    public CpuAffinity()
+    {
+        LinuxNative.CPU_ZERO(ref _cpuSet);
+    }
+
+    /// <summary>
+    /// Adds a CPU to the affinity set.
+    /// </summary>
+    /// <param name="cpu">CPU number (0-based)</param>
+    public void AddCpu(int cpu)
+    {
+        if (cpu < 0 || cpu >= LinuxNative.CPU_SETSIZE)
+        {
+            throw new ArgumentOutOfRangeException(nameof(cpu), 
+                $"CPU number must be between 0 and {LinuxNative.CPU_SETSIZE - 1}");
+        }
+        LinuxNative.CPU_SET(cpu, ref _cpuSet);
+    }
+
+    /// <summary>
+    /// Removes a CPU from the affinity set.
+    /// </summary>
+    /// <param name="cpu">CPU number (0-based)</param>
+    public void RemoveCpu(int cpu)
+    {
+        if (cpu < 0 || cpu >= LinuxNative.CPU_SETSIZE)
+        {
+            throw new ArgumentOutOfRangeException(nameof(cpu), 
+                $"CPU number must be between 0 and {LinuxNative.CPU_SETSIZE - 1}");
+        }
+        LinuxNative.CPU_CLR(cpu, ref _cpuSet);
+    }
+
+    /// <summary>
+    /// Checks if a CPU is in the affinity set.
+    /// </summary>
+    /// <param name="cpu">CPU number (0-based)</param>
+    /// <returns>True if CPU is in the set, false otherwise</returns>
+    public bool IsCpuSet(int cpu)
+    {
+        if (cpu < 0 || cpu >= LinuxNative.CPU_SETSIZE)
+        {
+            return false;
+        }
+        return LinuxNative.CPU_ISSET(cpu, ref _cpuSet) != 0;
+    }
+
+    /// <summary>
+    /// Gets the number of CPUs in the affinity set.
+    /// </summary>
+    public int CpuCount => LinuxNative.CPU_COUNT(ref _cpuSet);
+
+    /// <summary>
+    /// Gets all CPUs in the affinity set.
+    /// </summary>
+    /// <returns>List of CPU numbers</returns>
+    public List<int> GetCpus()
+    {
+        var cpus = new List<int>();
+        for (int i = 0; i < LinuxNative.CPU_SETSIZE; i++)
+        {
+            if (IsCpuSet(i))
+            {
+                cpus.Add(i);
+            }
+        }
+        return cpus;
+    }
+
+    /// <summary>
+    /// Sets CPU affinity for the current thread.
+    /// </summary>
+    /// <param name="cpus">List of CPU numbers to set</param>
+    public static void SetAffinity(params int[] cpus)
+    {
+        var affinity = new CpuAffinity();
+        foreach (var cpu in cpus)
+        {
+            affinity.AddCpu(cpu);
+        }
+        affinity.Apply();
+    }
+
+    /// <summary>
+    /// Applies the CPU affinity to the current thread.
+    /// </summary>
+    public void Apply()
+    {
+        if (_disposed)
+        {
+            throw new ObjectDisposedException(nameof(CpuAffinity));
+        }
+
+        IntPtr cpusetsize = new IntPtr(LinuxNative.CPU_SETSIZE / 8); // Size in bytes
+        int result = LinuxNative.sched_setaffinity(0, cpusetsize, ref _cpuSet);
+        if (result != 0)
+        {
+            LinuxNative.ThrowLastError("sched_setaffinity");
+        }
+    }
+
+    /// <summary>
+    /// Gets the current CPU affinity for the current thread.
+    /// </summary>
+    /// <returns>CpuAffinity object representing current affinity</returns>
+    public static CpuAffinity GetAffinity()
+    {
+        var cpuSet = new LinuxNative.cpu_set_t();
+        IntPtr cpusetsize = new IntPtr(LinuxNative.CPU_SETSIZE / 8);
+        int result = LinuxNative.sched_getaffinity(0, cpusetsize, ref cpuSet);
+        if (result != 0)
+        {
+            LinuxNative.ThrowLastError("sched_getaffinity");
+        }
+
+        var affinity = new CpuAffinity();
+        affinity._cpuSet = cpuSet;
+        return affinity;
+    }
+
+    /// <summary>
+    /// Clears all CPUs from the affinity set.
+    /// </summary>
+    public void Clear()
+    {
+        LinuxNative.CPU_ZERO(ref _cpuSet);
+    }
+
+    public void Dispose()
+    {
+        if (!_disposed)
+        {
+            _disposed = true;
+        }
+    }
+}
+