Getting HttpContext from BackgroundWorker process

I have an ASP.NET site and I've been doing some work refactoring code t开发者_运维问答o try to remove some long running processes (in the order of an hour) from the actual http Request by creating a BackgroundWorker and sending the work off to that to process. This was running fine on cutdown tests but when I applied the logic to the real code I found problems accessing Session variables from the code running in the Background Worker. It seems that the HttpContext object that was passed has a null session and if I ask for HttpContext.Current I get null back.

I'm assuming that this is because they are in a different thread and that the session and HttpContext.Current are both reliant on being in the same thread. Is there any way I can get access to the Session from the background worker or am I stuck with finding all the variables I need from session and putting them in an usable data structure and then putting them back in session (if appropriate) afterwards? It obviously complicates the refactor massively if I need to do this so I'd rather not.

Thanks for any thoughts you might have. I'm open to other suggestions on how I might do this other than BackgroundWorker processes (which were suggested to me in another question).

I'm not sure of all of your requirements, but you may be able to get away with using the Application Cache instead of the Session if you're not looking for the long process to be tied to an individual user's request.

If so, I would try swapping out your use of Session to:

HttpRuntime.Cache.Set("CacheKeyName");
HttpRuntime.Cache.Get("CacheKeyName");

Here's an MSDN link that sheds some light on this. The text in particular is :

If an asynchronous action method calls a service that exposes methods by using the BeginMethod/EndMethod pattern, the callback method (that is, the method that is passed as the asynchronous callback parameter to the Begin method) might execute on a thread that is not under the control of ASP.NET. In that case, HttpContext.Current will be null, and the application might experience race conditions when it accesses members of the AsyncManager class such as Parameters. To make sure that you have access to the HttpContext.Current instance and to avoid the race condition, you can restore HttpContext.Current by calling Sync() from the callback method.