Just a problem faced in asp.net using MVC architecture. I was suppose to open popup window to send email from a webpage. It was working fine, however I wanted to do not wait till popup complete sending email function and user can work on another tasks in main parent window. However it was not working and I have to wait till child finishes sending email.
So I was trying to execute concurrent requiests, however session was not permitting to do it. If two different users make concurrent requests to access separate session is achievaable. But if I am trying two concurrent requests for the same session by using same sessionid, it was waiting till first request is finished and vice-versa. So it was adding exclusive lock on the information is freed becaus the first request exceeds the lock time-out.
However I wanted to provide such a functionality in my website, I searched and found a solution. To resolve this issue we need to set EnableSessionState value in the @Page directive to Read-only, means a request for the read-only session information does not result in an exclusive lock on Session data. But read-only requests for session data may still have to wait for a lock set by a read-write request for session to clear.
This was one good setting we have learned in asp.net. Hope it will be helpful to others too. You can read more about ASP.Net Session State on: ASP.NET Session State Overview