/// <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; if (LibC.sched_setaffinity(0, (IntPtr)8, ref mask) != 0) { return(GroupAffinity.Undefined); } return(new GroupAffinity(0, result)); } UIntPtr uIntPtrMask; try { uIntPtrMask = (UIntPtr)affinity.Mask; } catch (OverflowException) { throw new ArgumentOutOfRangeException(nameof(affinity)); } var groupAffinity = new Kernel32.GROUP_AFFINITY { Group = affinity.Group, Mask = uIntPtrMask }; IntPtr currentThread = Kernel32.GetCurrentThread(); try { if (Kernel32.SetThreadGroupAffinity(currentThread, ref groupAffinity, out Kernel32.GROUP_AFFINITY previousGroupAffinity)) { return(new GroupAffinity(previousGroupAffinity.Group, (ulong)previousGroupAffinity.Mask)); } return(GroupAffinity.Undefined); } catch (EntryPointNotFoundException) { if (affinity.Group > 0) { throw new ArgumentOutOfRangeException(nameof(affinity)); } ulong previous = (ulong)Kernel32.SetThreadAffinityMask(currentThread, uIntPtrMask); return(new GroupAffinity(0, previous)); } }