I have now found out that ASP.NET does lock all requests if you use sessions (e.g. here), meaning that if there are 2 concurrent requests then one has to wait until the first one is finished. I have few questions with regards to that as I was not able to find the answers:
- If session is not used (turned off in IIS), does it still do this locking?
- What is the algorithm that is used to determine if the locking is needed? Is it simply locking ALL requests if session is turned on? Does it try to analyze the code to see if session is used there?
- Does it affect non aspx requests like css, javascript, custom handlers and such?
