如何检测多线程使用？

Question

是否足以比较ManagedThreadId创建对象时和调用方法以验证它是否未在多线程场景中使用？

public class SingleThreadSafe
{
    private readonly int threadId;
    public SingleThreadSafe()
    {
        threadId = Thread.CurrentThread.ManagedThreadId;
    }

    public void DoSomethingUsefulButNotThreadSafe()
    {
        if(threadId!=Thread.CurrentThread.ManagedThreadId)
        {
            throw new InvalidOperationException(
                "This object is being accessed by a thread different than the one that created it. " +
                " But no effort has been made to make this object thread safe.");
        }
        //Do something useful, like use a previously established DbConnection
    }
}

我的直觉在线程方面经常是错误的,所以我想检查一下我是否应该记住边缘情况.

Answer 1

不，这还不够！

托管线程 ID可以由 CLR重用，因此即使调用线程与用于构造对象的线程不同，也if(threadId!=Thread.CurrentThread.ManagedThreadId)可以返回。false

您想要实现的目标可以通过参考比较来实现：

if (!object.ReferenceEquals(Thread.CurrentThread, ThreadThatCreatedThis))
// ...

编辑 ：

然而MSDN说：

ManagedThreadId 属性的值不会随时间变化，即使承载公共语言运行时的非托管代码将线程实现为纤程也是如此。

http://msdn.microsoft.com/en-us/library/system.threading.thread.managedthreadid%28v=vs.110%29.aspx