Question

Is the snippet below “safe” for performing some initialization once in a multithreaded program?

I’m a bit worried that boxing/unboxing might cause some problem…

private static object initialized = false;

public static void Initialize()
{
  lock (initialized)
  {
    if ((bool)initialized == false)
    {
      DoInitialization();
      initialized = true;
    }
  }
}

Note that I can’t just do the initialization from Main or some other single threaded context.

Answer 1

You are right – that’s not going to work because you are reassigning the object you are locking on.

You can do this with two seperate members – an object to lock on that is assigned only once, and then a boolean that you can read or assign to (after you have locked).

You may also want to consider if a singleton would be appropriate here.