SpinLock抛出SynchronizationLockException

Question

我正在尝试使用SpinLock,但是当我调用SpinLock.Exit()时,即使是单线程控制台应用程序中的这个最基本的代码也会引发以下异常

System.Threading.SynchronizationLockException was unhandled by user code
  Message=The calling thread does not hold the lock.  Source=mscorlib

这是完整的源代码......

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace ConsoleApplication48
{
    class Program
    {
        static readonly SpinLock SpinLock = new SpinLock();
        static void Main(string[] args)
        {
            bool lockTaken = false;
            try
            {
                SpinLock.Enter(ref lockTaken);
                if (lockTaken)
                    Console.WriteLine("Lock taken");
            }
            finally
            {
                if (lockTaken)
                    SpinLock.Exit();
            }
            Console.WriteLine("Done");
        }
    }
}

Answer 1

SpinLock是一个结构体,您正在从只读字段中读取它.C#规范说,在这种情况下,为了调用潜在的变异函数,必须将结构复制到可变局部变量.这发生在封面下.

您对进入和退出的呼叫发生在锁的新副本上.因此,Enter正在解锁锁定.

不要让SpinLock变量只读,因为它正在变异.