如何在一个静态方法中锁定类的私有静态字段，然后在其他实例方法中释放它？

Question

I have a private static field in my Controller class in an MVC web application.

I have a static method in that controller that assigns some value to that static field, I want to apply lock on that static field until some other instance method in the controller uses the value stored in the static field and then releases it.

How can I do this ?

DETAILS:

I have a controller named BaseController having a static ClientId field as follows and two methods as follows:-

public static string ClientId = "";

static void OnClientConnected(string clientId, ref Dictionary<string, object> list)
        {
            list.Add("a", "b");
// I want the ClientId to be locked here, so that it can not be accessed by other requests coming to the server and wait for ClientId to be released:-
            BaseController.clientId = clientId; 
        }

public ActionResult Handler()
        {
            if (something)
            {
                // use the static ClientId here
            }
// Release the ClientId here, so it can now be used by other web requests coming to the server.
            return View();
        }

Answer 1

You can't just use a lock to wait you need an AutoResetEvent (or equivalent). Something like this may prove useful :

// Provide a way to wait for the value to be read;
// Initially, the variable can be set.
private AutoResetEvent _event = new AutoResetEvent(true);

// Make the field private so that it can't be changed outside the setter method
private static int _yourField;

public static int YourField {
    // "AutoResetEvent.Set" will release ALL the threads blocked in the setter.
    // I am not sure this is what you require though.
    get { _event.Set(); return _yourField; }

    // "WaitOne" will block any calling thread before "get" has been called.
    // except the first time
    // You'll have to check for deadlocks by yourself
    // You probably want to a timeout in the wait, in case
    set { _event.WaitOne(); _yourField = value; }
}