Comments on: HttpContext idiom for Windows Communication Foundation.

By: Valeriu Caraulean

Valeriu Caraulean — Fri, 29 Oct 2010 16:35:26 +0000

Hmm, since you pointed me, reviewed the code and you’re probably right.
I think it will be safer to add a lock around creation of the context.
For the time we had this code in production we haven’t felt any suspicious behavior, probably because it was in a not too active endpoint.

By: Job Vermeulen

Job Vermeulen — Fri, 29 Oct 2010 11:16:05 +0000

Are you sure this is thread-safe?

By: Job Vermeulen

Job Vermeulen — Fri, 29 Oct 2010 11:13:08 +0000

Thanks for this very clean solution, I’ve found some other ideas to create this but this one rocks

By: Valeriu Caraulean

Valeriu Caraulean — Sat, 18 Apr 2009 21:00:52 +0000

@vince
For us, the anwer was “you don’t”.
We don’t keep the state between calls. Our services are steless. And, so far, we’re happy with it…

Back to keeping the state, if your serivice is instantiated “Per Call” you will not have any context between calls. But you can use “Per Session” mode on your services. This way, between calls you’ll have same InstanceContext (and/or the OperationContext, I don’t remember now, sorry).

But if your question was really about “persisting” data to some durable storage, the database does it well.

By: vince

vince — Sat, 18 Apr 2009 17:35:12 +0000

Ok, the context works. But how do you persist the data between calls to the service. Items are cleared on each call. I have no idea how this session works on WCF.

By: Valeriu Caraulean

Valeriu Caraulean — Thu, 19 Mar 2009 13:42:33 +0000

I haven’t working with WCF for a while and I don’t remember details, but probably you’re right…

By: shlomi

shlomi — Thu, 19 Mar 2009 13:31:33 +0000

Found the solution – instead of using InstanceContext extension – use OperationContext extension. I think this is also more appropriate to what you meant.

public class WcfOperationContext : IExtension
{
private readonly IDictionary items;

private WcfOperationContext()
{
items = new Hashtable();
}

public IDictionary Items
{
get { return items; }
}

public static WcfOperationContext Current
{
get
{
WcfOperationContext context = OperationContext.Current.Extensions.Find();
if (context == null)
{
context = new WcfOperationContext();
OperationContext.Current.Extensions.Add(context);
}
return context;
}
}

public void Attach(OperationContext owner) { }

public void Detach(OperationContext owner) { }

}

By: shlomi

shlomi — Thu, 19 Mar 2009 13:14:03 +0000

What would you do if your WCF service is singleton?
(the items remains in the dictionary regardsless of the WCF request context, as in HttpContext).

Thanks,
Shlomi