dotnet 进程优先级调整，Support Linux or Windows

Windows: 进程变更到最大优先级

Linux: 进程变换为：

PR rt（实时模式-进程）

NI -20（最高优先级）

使用方法：

Priority.AdjustToHighestPriority();

源码实现： 

namespace MyServer.Utilits
{
    using System;
    using System.Diagnostics;
    using System.Runtime.InteropServices;
    using System.Security;

    public static unsafe class Priority
    {
        [Dllimport("libc", EntryPoint = "getpid", CallingConvention = CallingConvention.Cdecl)]
        private static extern int getpid();

        [Dllimport("libc", EntryPoint = "setpriority", CallingConvention = CallingConvention.Cdecl)]
        private static extern int setpriority(int which, int who, int prio);

        [Dllimport("libc", EntryPoint = "sched_get_priority_max", CallingConvention = CallingConvention.Cdecl)]
        private static extern int sched_get_priority_max(int policy);

        [Dllimport("libc", EntryPoint = "sched_setscheduler", CallingConvention = CallingConvention.Cdecl)]
        private static extern int sched_setscheduler(int __pid, int __policy, sched_param* __param);

        [Dllimport("kernel32", EntryPoint = "SetPriorityClass", CallingConvention = CallingConvention.StdCall)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool SetPriorityClass(IntPtr hProcess, uint dwPriorityClass);

        private const uint HIGH_PRIORITY_CLASS = 128;
        private const int PRIO_PROCESS = 0;
        private const int SCHED_FIFO = 1;
        private const int SCHED_RR = 2;

        
        [StructLayout(LayoutKind.Sequential)]
        private struct sched_param
        {
            public int sched_priority;
        };

        [SecurityCritical]
        [SecuritySafeCritical]
        public static void AdjustToHighestPriority()
        {
            if (Environment.OSVersion.Platform == PlatformID.Win32NT)
            {
                IntPtr hProcess = Process.GetCurrentProcess().Handle;
                SetPriorityClass(hProcess, HIGH_PRIORITY_CLASS);
            }
            else
            {
                
                setpriority(PRIO_PROCESS, 0, -20);

                
                sched_param param_;
                param_.sched_priority = sched_get_priority_max(SCHED_FIFO); // SCHED_RR
                sched_setscheduler(getpid(), SCHED_RR, ¶m_);
            }
        }
    }
}