How to detect cross thread access in .NET (enforce thread affinity)?

Question

I\'m writing a special data structure that will be available in a .NET library and one of the features of this data structure is that is will be thread safe provided that only o

Answer 1

When I run into this situation I use a class I wrote called ThreadAffinity. It's entire purpose is to record the current thread and throw on invalid accesses from a different thread. You have to manually do the check but it encapsulates the small amount of work for you.

class Foo {
  ThreadAffinity affinity = new ThreadAffinity();

  public string SomeProperty {
    get { affinity.Check(); return "Somevalue"; }
  }
}

Class

[Immutable]
public sealed class ThreadAffinity
{
    private readonly int m_threadId;

    public ThreadAffinity()
    {
        m_threadId = Thread.CurrentThread.ManagedThreadId;
    }

    public void Check()
    {
        if (Thread.CurrentThread.ManagedThreadId != m_threadId)
        {
            var msg = String.Format(
                "Call to class with affinity to thread {0} detected from thread {1}.",
                m_threadId,
                Thread.CurrentThread.ManagedThreadId);
            throw new InvalidOperationException(msg);
        }
    }
}

Blog post on the subject:

• http://blogs.msdn.com/jaredpar/archive/2008/02/22/thread-affinity.aspx