为什么我无法获取线程的 ProcessorAffinity？

Question

我正在制作 CPU 使用统计的程序。我有一个列表Processes, each one with its Process.Threads. For each thread, I want to know its current affinity to know which CPU Core it is binded to, but ProcessThread.ProcessAffinity只能设置...不能读取！

为什么？有没有办法获取这些信息？

此外，我可以不调用低级 Win32 函数而只调用 .NET Standards 来获取它吗？

Answer 1

在@oliver-rogier 的提示下，我设法通过使用函数设置掩码（从 C++ 导入）来完成。如文档中所述：

Return value

If the function succeeds, the return value is the thread's previous affinity mask.

[DllImport(@"kernel32.dll", SetLastError = true)]
static extern IntPtr SetThreadAffinityMask(IntPtr hThread, IntPtr dwThreadAffinityMask);


public static IntPtr GetThreadAffinityMask(uint threadId)
{
    Thread.BeginThreadAffinity();

    // get the handle
    IntPtr hThread = OpenThread(ThreadAccess.SET_INFORMATION | ThreadAccess.QUERY_INFORMATION, false, threadId);
    if (hThread == INVALID_HANDLE_VALUE)
    {
        var err = GetLastError();
        return IntPtr.Zero;
    }

    // there is no "get" for affinity mask, but the "set" function returns the mask before the operation
    // so first set a temp mask to obtain the current one
    IntPtr old = SetThreadAffinityMask(hThread, new IntPtr((int)Math.Pow(2, Environment.ProcessorCount)) - 1);
    if (old == IntPtr.Zero)
    {
        var err = GetLastError();
        return old;
    }

    // then restore the original value
    SetThreadAffinityMask(hThread, old);

    CloseHandle(hThread);
    Thread.EndThreadAffinity();

    return old;
}

为什么我无法获取线程的 ProcessorAffinity？

Why I can't get the ProcessorAffinity of a thread?

c#

process

cpu

affinity