连续监视线程的CPU使用情况

Question

我需要一个线程在Windows服务，它不断监测CPU的使用(也许每5秒)。如果CPU使用率较低，则应激活其他线程。

我已经从这个SO Question中找到了一个示例CPU使用监控代码(我在下面的文章中也给出了)。这是控制台应用程序的代码，为了保持Timer正常运行，用户在最后使用Console.ReadLine();。

CPU使用控制台应用程序：

using System;
using System.Diagnostics;
using System.Timers;
using System.Threading;
using System.Collections.Generic;

namespace CPUPerformanceMonitor
{
    class MonitoringApplication
    {
        protected static PerformanceCounter cpuCounter;
        protected static PerformanceCounter ramCounter;

        public static void TimerElapsed(object source, ElapsedEventArgs e)
        {
            float cpu = cpuCounter.NextValue();
            float ram = ramCounter.NextValue();
            Console.WriteLine(string.Format("CPU Value: {0}, ram value: {1}", cpu, ram));
        }

        public static void Main()
        {
            cpuCounter = new PerformanceCounter();
            cpuCounter.CategoryName = "Processor";
            cpuCounter.CounterName = "% Processor Time";
            cpuCounter.InstanceName = "_Total";

            ramCounter = new PerformanceCounter("Memory", "Available MBytes");

            try
            {
                System.Timers.Timer t = new System.Timers.Timer(1200);
                t.Elapsed += new ElapsedEventHandler(TimerElapsed);
                t.Start();
                Thread.Sleep(10000);
            }
            catch (Exception e)
            {
                Console.WriteLine("catched exception");
            }

            while (true) //Another sample BAD way to keep the timer alive
            { }

            //Console.ReadLine(); //just to keep the time alive
        }
    }
}

问题：如何在Windows应用程序中实现它.我是说，我怎样才能维持这条线。

My Windows-服务结构：

我调用线程回调方法OnStart()。这个线程回调方法调用类CPUMonitor的CPUMonitor方法(它包含Timer的代码)。

    public void CPUMonitorinigThreadCallback()
    {
        //If nothing is there in this function, the thread will start up and then immediately shutdown. To deal with this situation, use "_shutdownEvent"
        //The while loop checks the ManualResetEvent to see if it is "set" or not.
        while (!_shutdownEvent.WaitOne(0))
        {
            // Replace the Sleep() call with the work you need to do
            //Sleep(1000);
            objCPUMonitor.StartCPUMonitorinig();
        }

    }

Answer 1

要将其实现为Service类型，您必须考虑输出性能数据的位置和方式。使用Windows，我可以建议创建另一个应用程序或覆盖，然后在Service结束更新时显示这些值。这可以使用共享内存、文件、数据库、windows消息泵、std out等来完成。

考虑到这些因素，您实际上可以通过创建一个service对象来开始您的服务：

public class MeService : ServiceBase
{
    // for the ability to redirect stream
    [DllImport("Kernel32.dll", SetLastError = true) ]
    public static extern int SetStdHandle(int device, IntPtr handle); 

    // entry point
    public static void Main(string[] args)
    {
        ServiceBase[] ServicesToRun;
        ServicesToRun = new ServiceBase[]
        {
            new MeService()
        };
        ServiceBase.Run(ServicesToRun);
    }

    PerformanceObject pObject; // object to retrieve and return performance status
    IContainer components;
    FileStream fStream;
    public MeService()
        : base()
    {
        components = new Container(); // initialize components holder
        ServiceName = "MeService"; // set your service name
    }

    // Here check for custom commands on your service
    protected override void OnCustomCommand(int command)
    {
        if(command == 1)
        {
            // redirect stream
            fStream = new FileStream("<path_to_your_out_file>", <FileMode.Here>, <FileAccess.Here>);
            IntPtr streamHandle = fStream.Handle;
            SetStdHandle(-11, handle); // DWORD -11  == STD OUT
        }
        else if(command == 1337 && pObject != null) // example command
        {
            // write string.Format("CPU Value: {0}, ram value: {1}", cpu, ram);
            // into your service's std out
            Console.WriteLine(pObject.GetPerformance()); 
        }
        base.OnCustomCommand(command);
    }

    // whenever service starts create a fresh performance counter object
    protected override void OnStart(string[] args) // will be called when service starts
    {
        pObject = new PerformanceObject();
    }

    // called whenever service is stopped
    protected override void OnStop()
    {
        // remove performance counter object 
        pObject.Dispose();
        pObject = null;
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            if (components != null)
            {
                components.Dispose();
            }

            if (pObject != null)
            {
                pObject.Dispose();
            }
        }
        base.Dispose(disposing);
    }
}

现在，在完成这些操作之后，您可以创建“显示”应用程序。这应该将服务的std重定向到它自己的读取器，使您能够从该流中读取。

class Program
{
    static void Main(string[] args)
    {
        FileStream fileStream = new FileStream("<PATH_TO_THE_SAME_FILE_AS_SERVICE>", <FileMode.Here>, <FileAccess.Here>);
        // create service controller that will control "MeService" service
        ServiceController Controller = new ServiceController("MeService");
        if (Controller.Status == ServiceControllerStatus.Stopped)
        {
            Controller.Start();
        }

        while (Controller.Status != ServiceControllerStatus.Running)
        ;

        Controller.ExecuteCommand(1); // redirect the stream.           

        string command = string.Empty;
        while( ( command = Console.ReadLine() ) != "exit" )
        {
            if(command == "refresh")
            {
                if (Controller.Status == ServiceControllerStatus.Running)
                {
                    Controller.ExecuteCommand(1337);
                    string performance = fileStream.ReadLine();
                    Console.WriteLine(performance);
                } 
            }
        }
    }
}

现在，您所要做的就是在服务中创建一个安装文件，并创建您已经拥有的PerformanceObject，但是您必须修改它，以便在上面的代码段中使用它。