A Question About C# and Static Classes and Functions

Question

I've seen a lot of discussion about this subject on here.

If i have a static class w/ static methods that connects to a database or a server, is it a bad idea to use this in a multi-user environment (like a web page)? Would this make a new user's tread wait for previous users' threads to finish their calls before accepting a new one?

What would be the implications of this with multi-threading, also?

Thx!

Answer 1

If each static method is fully responsible for acquiring its resources and then disposing its resources within the scope of the method call (no shared state), then you shouldn't have any problem with threading that you wouldn't have using instance classes. I would suggest, however, that the bigger problem is that a reliance on public static methods (in static or non-static classes) creates many other design problems down the road.

• First of all, you're binding very tightly to an implementation, which is always bad.
• Second, testing all of the classes that depend on your static methods becomes very difficult to do, because you're locked to a single implementation.
• Third, it does become very easy to create non-thread safe methods since static methods can only have static state (which is shared across all method calls).

Answer 2

Static methods do not have any special behaviour in respect to multithreading. That is, you can expect several "copies" of the method running at the same time. The same goes for static variables - different threads can access them all at once, there is no waiting there. And unless you're careful, this can create chaos.