Do ASP.NET Requests always BeginRequest and EndRequest on the same thread?

Question

Does BeginRequest and EndRequest for an ASP.NET HttpApplication always occur on the exact same thread for a given HTTP request from a client?

The reason I ask is tha

Answer 1

No, as per Richard's answer.

As an aside, you're supposed to "share" variables between HTTP Modules via HttpContext.Current.Items. In the case of [ThreadStatic], due to thread agility in ASP.NET it's not guaranteed that your code will start and finish on the same thread. So, ThreadStatic isn't such a great idea in ASP.NET.

It's worth saying that EndRequest will always execute with the same HttpContext.

This seems to be the definitive post on using [ThreadStatic] verses HttpContext http://piers7.blogspot.co.nz/2005/11/threadstatic-callcontext-and_02.html

Scott Hanselman also posted on the subject:
http://www.hanselman.com/blog/ATaleOfTwoTechniquesTheThreadStaticAttributeAndSystemWebHttpContextCurrentItems.aspx

And Jon Skeet has a good SO answer here too:
CallContext vs ThreadStatic