Access HttpContext.Current from different threads

Question

I have a C# ASP.NET application which starts about 25 different threads running some methods in a class called SiteCrawler.cs.

In HttpContext.Current.Session I want to save the result of the search made by the user and present it to the user when all the threads are finished running. My problem is that the HttpContext.Current object is null in the spawned threads because it doesn't exist there.

What other options do I have to save user/session specific data without using session because of the limitations when the application is multithreaded?

I have tried to search around every inch of Stackoverflow to find a solution but without any luck....

Answer 1

In my application there are a lot of code that uses HttpContext.Current and I can not modify that code.

worker.DoWork() from sample below uses that code. And I had to run it in separate thread.

I came to the following solution:

 HttpContext ctx = HttpContext.Current;  Thread t = new Thread(new ThreadStart(() =>                 {                     HttpContext.Current = ctx;                     worker.DoWork();                 }));  t.Start();  // [... do other job ...]  t.Join(); 

Answer 2

Have a look at this article by Fritz Onion: Use Threads and Build Asynchronous Handlers in Your Server-Side Web Code. It's quite long, but your requirement is not too trivial.

Also K. Scott Allen posted a somewhat shorter article about this very issue: Working With HttpContext.Current