ASP.NET check on thread status on long running thread?

Question

I have a situation where user requests to do a long running process. I planing to start it on another thread in code-behind and return message to user "processing". Then every couple of seconds or so I will poll(via asynch call) the thread for its status. When thread is done I want to show success message.

Question, how do I poll a thread once the original request is complete?

As far as I understand, Page object will spin off a separate thread. When request is complete, the Page object is no longer there...but what about that thread? How do I get the status of that thread that I created?

Answer 1

Well, you'll need some way of identifying the request. If you want to be able to scale this out to multiple machines, you should look at storing the request ID and current status in a database (or some similarly accessible-from-anywhere storage).

If you don't care about that situation and you're not worried about AppDomain recycling, you could just have a singleton dictionary from request ID to status - but consider making it automatically flush itself after some period if the client just goes away and doesn't check the status.

(Of course it doesn't have to be a true singleton - it could be some shared resource provided with dependency injection, but the point is it needs to be shared somehow so you can get at it from the new request.)

You could also potentially use a session-backed object - again with caveats about multi-server web sites and AppDomain recycling.