/*

  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) 2010-2014 Michael Möller <mmoeller@openhardwaremonitor.org>

*/

using System;

using System.Runtime.InteropServices;

namespace OpenHardwareMonitor.Hardware {

  internal static class ThreadAffinity {

    public static ulong Set(ulong mask) { 

      if (mask == 0)

        return 0;

      int p = (int)Environment.OSVersion.Platform;

      if ((p == 4) || (p == 128)) { // Unix

        ulong result = 0;

        if (NativeMethods.sched_getaffinity(0, (IntPtr)Marshal.SizeOf(result), 

          ref result) != 0)          

          return 0;

        if (NativeMethods.sched_setaffinity(0, (IntPtr)Marshal.SizeOf(mask), 

          ref mask) != 0)

          return 0;

        return result;

      } else { // Windows

        UIntPtr uIntPtrMask;

        try {

          uIntPtrMask = (UIntPtr)mask;

        } catch (OverflowException) {

          throw new ArgumentOutOfRangeException("mask");

        }

        return (ulong)NativeMethods.SetThreadAffinityMask(

          NativeMethods.GetCurrentThread(), uIntPtrMask);

      }

    }

    private static class NativeMethods {      

      private const string KERNEL = "kernel32.dll";

      [DllImport(KERNEL, CallingConvention = CallingConvention.Winapi)]

      public static extern UIntPtr

        SetThreadAffinityMask(IntPtr handle, UIntPtr mask);

      [DllImport(KERNEL, CallingConvention = CallingConvention.Winapi)]

      public static extern IntPtr GetCurrentThread();       

      private const string LIBC = "libc";

      [DllImport(LIBC)]

      public static extern int sched_getaffinity(int pid, IntPtr maskSize,

        ref ulong mask);

      [DllImport(LIBC)]

      public static extern int sched_setaffinity(int pid, IntPtr maskSize,

        ref ulong mask);  

    }  

  }

}