Will calling close() on my WCF service release all resources?

Question

Will calling close on my WCF service kill all resources or set them up for GC or should I set it to null also?

Answer 1

You only need to set a variable to null if it's going to be reachable for a long time afterwards. Say, a field on a long-lived object, or a static field. This holds in general, not just for WCF.

Answer 2

This is not so much a WCF question as a .NET question; see also

http://stackoverflow.com/questions/2785/setting-objects-to-null-nothing-after-use-in-dot-net

http://stackoverflow.com/questions/328743/is-disposing-this-object-enough-or-do-i-need-to-do-more

http://stackoverflow.com/questions/328743/is-disposing-this-object-enough-or-do-i-need-to-do-more

http://stackoverflow.com/questions/456551/in-the-disposebool-method-implementation-shouldnt-one-set-members-to-null

Answer 3

Firstly, WCF proxies are IDisposable, so you can kind of use using:

using(var proxy = new MyProxy()) { // see below - not quite enough
   // use proxy
}

Unfortunately, WCF also has a buggy Dispose() implementation that regularly throws exceptions. However, here's a really cool trick to get it to work correctly. I also blogged about this myself, but I think the first link is a lot better.

So: use IDisposable and using, but use it with caution (in this case).

Setting a field usually makes no difference. There are a few edge-cases (such as variables captured by multiple delegates, static fields, long-life objects, etc), but in general leave it alone. In particular, do not do this, as this can theoretically extend the life:

if(field != null) field = null; // BAD