有没有办法通过。net / c#找到CPU核数?

PS:这是一个直接的代码问题,不是一个“我应该使用多线程吗?”的问题!: -)


当前回答

一种选择是从注册中心读取数据。 MSDN文章主题:http://msdn.microsoft.com/en-us/library/microsoft.win32.registry.localmachine(v=vs.71).aspx)

处理器,我相信可以在这里,HKEY_LOCAL_MACHINE\硬件\描述\系统\中央处理器

    private void determineNumberOfProcessCores()
    {
        RegistryKey rk = Registry.LocalMachine;
        String[] subKeys = rk.OpenSubKey("HARDWARE").OpenSubKey("DESCRIPTION").OpenSubKey("System").OpenSubKey("CentralProcessor").GetSubKeyNames();

        textBox1.Text = "Total number of cores:" + subKeys.Length.ToString();
    }

我相当肯定大多数系统上都有这个注册表项。

我想把我的0.02美元投进去。

其他回答

来自。net Framework源代码

你也可以在Kernel32.dll上使用PInvoke来获得它

下面的代码或多或少来自System的SystemInfo.cs。网址来源:

[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct SYSTEM_INFO
{
  public ushort wProcessorArchitecture;
  public ushort wReserved;
  public uint dwPageSize;
  public IntPtr lpMinimumApplicationAddress;
  public IntPtr lpMaximumApplicationAddress;
  public IntPtr dwActiveProcessorMask;
  public uint dwNumberOfProcessors;
  public uint dwProcessorType;
  public uint dwAllocationGranularity;
  public ushort wProcessorLevel;
  public ushort wProcessorRevision;
}

internal static class SystemInfo 
{
    static int _trueNumberOfProcessors;
    internal static readonly IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);    

    [DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
    internal static extern void GetSystemInfo(out SYSTEM_INFO si);

    [DllImport("kernel32.dll")]
    internal static extern int GetProcessAffinityMask(IntPtr handle, out IntPtr processAffinityMask, out IntPtr systemAffinityMask);

    internal static int GetNumProcessCPUs()
    {
      if (SystemInfo._trueNumberOfProcessors == 0)
      {
        SYSTEM_INFO si;
        GetSystemInfo(out si);
        if ((int) si.dwNumberOfProcessors == 1)
        {
          SystemInfo._trueNumberOfProcessors = 1;
        }
        else
        {
          IntPtr processAffinityMask;
          IntPtr systemAffinityMask;
          if (GetProcessAffinityMask(INVALID_HANDLE_VALUE, out processAffinityMask, out systemAffinityMask) == 0)
          {
            SystemInfo._trueNumberOfProcessors = 1;
          }
          else
          {
            int num1 = 0;
            if (IntPtr.Size == 4)
            {
              uint num2 = (uint) (int) processAffinityMask;
              while ((int) num2 != 0)
              {
                if (((int) num2 & 1) == 1)
                  ++num1;
                num2 >>= 1;
              }
            }
            else
            {
              ulong num2 = (ulong) (long) processAffinityMask;
              while ((long) num2 != 0L)
              {
                if (((long) num2 & 1L) == 1L)
                  ++num1;
                num2 >>= 1;
              }
            }
            SystemInfo._trueNumberOfProcessors = num1;
          }
        }
      }
      return SystemInfo._trueNumberOfProcessors;
    }
}

我正在寻找同样的事情,但我不想安装任何nuget或服务包,所以我找到了这个解决方案,这是相当简单和直接的, 使用这个讨论,我认为运行WMIC命令并获得该值会很容易,下面是c#代码。你只需要使用系统。管理名称空间(以及用于进程等的更多标准名称空间)。

string fileName = Path.Combine(Environment.SystemDirectory, "wbem", "wmic.exe");
string arguments = @"cpu get NumberOfCores";

Process process = new Process
{
    StartInfo =
    {
        FileName = fileName,
        Arguments = arguments,
        UseShellExecute = false,
        CreateNoWindow = true,
        RedirectStandardOutput = true,
        RedirectStandardError = true
    }
};

process.Start();

StreamReader output = process.StandardOutput;
Console.WriteLine(output.ReadToEnd());


process.WaitForExit();
int exitCode = process.ExitCode;
process.Close();

你可以使用这个类:

public static class CpuCores
{
    private static int cores = 0;
    
    public static int Number
    { 
        get
        {
            if (cores > 0) return cores;

            RegistryKey key = Registry.LocalMachine.OpenSubKey(@"SYSTEM\CurrentControlSet\Control\Class\" +
                "{50127dc3-0f36-415e-a6cc-4cb3be910b65}");
            if (key == null)
            {
                cores = Environment.ProcessorCount;
                return cores;
            }
            string[] subkeys = key.GetSubKeyNames();
            key.Close();
            cores = 0;
            if (subkeys != null && subkeys.Length > 0) foreach (string s in subkeys)
            {
                if (s.Length != 4) continue;
                int n;
                if (int.TryParse(s, out n) && ++n > cores) cores = n;
            }
            if (cores <= 0) cores = Environment.ProcessorCount;
            return cores;
        } 
    }
}
Environment.ProcessorCount

(文档)

环境。ProcessorCount应该提供本地机器上的核数。