HttpModules life in ASP.NET MVC - asp.net-mvc

Question

I find a code about counting online users in Asp.Net. I add it to my MVC project but its not working. There is a custom Httpmodule that has a Init() function and it is being called in every request. where is the problem.
init() must be run one time for all application lifecycle , but it is running on every request.
This code run well on asp.net but because of init() method run in every request it is not working on MVC.
public class OnlineUsersModule : IHttpModule
{
private static Int32 _sessionTimeOut = 20; // Set Default to 20 Minutes
private static List<OnlineUserInfo> _onlineUsers = null;
public static List<OnlineUserInfo> OnlineUsers
{
get
{
CleanExpiredSessions();
return _onlineUsers;
}
}
private static void CleanExpiredSessions()
{
_onlineUsers.RemoveAll(delegate(OnlineUserInfo user)
{
return user.SessionStarted.AddMinutes(_sessionTimeOut) < DateTime.Now;
});
}
#region IHttpModule Members
public void Init(HttpApplication context)
{
_onlineUsers = new List<OnlineUserInfo>();
// Get the Current Session State Module
SessionStateModule module = context.Modules["Session"] as SessionStateModule;
module.Start += new EventHandler(Session_Start);
}
private void Session_Start(object sender, EventArgs e)
{
HttpRequest Request = HttpContext.Current.Request;
HttpApplicationState Application = HttpContext.Current.Application;
HttpSessionState Session = HttpContext.Current.Session;
// Get Session TimeOut
_sessionTimeOut = HttpContext.Current.Session.Timeout;
Application.Lock();
OnlineUserInfo user = new OnlineUserInfo();
user.SessionId = Session.SessionID;
user.SessionStarted = DateTime.Now;
user.UserAgent = !String.IsNullOrEmpty(Request.UserAgent)
? Request.UserAgent : String.Empty;
user.IPAddress = !String.IsNullOrEmpty(Request.UserHostAddress)
? Request.UserHostAddress : String.Empty;
if (Request.UrlReferrer != null)
{
user.UrlReferrer = !String.IsNullOrEmpty(Request.UrlReferrer.OriginalString)
? Request.UrlReferrer.OriginalString : String.Empty;
}
else
{
user.UrlReferrer = String.Empty;
}
if (HttpContext.Current.User.Identity.IsAuthenticated)
{
user.CurrentUser = HttpContext.Current.User;
}
// Add the New User to Collection
_onlineUsers.Add(user);
Application.UnLock();
}
public void Dispose()
{
}
#endregion
}
public class OnlineUserInfo
{
public String UserAgent { get; set; }
public String SessionId { get; set; }
public String IPAddress { get; set; }
public String UrlReferrer { get; set; }
public DateTime SessionStarted { get; set; }
public IPrincipal CurrentUser { get; set; }
public override string ToString()
{
StringBuilder sb = new StringBuilder();
sb.AppendFormat("UserAgent = {0} | ", UserAgent);
sb.AppendFormat("SessionId = {0} | ", SessionId);
sb.AppendFormat("IPAddress = {0} | ", IPAddress);
sb.AppendFormat("UrlReferrer = {0} | ", UrlReferrer);
sb.AppendFormat("SessionStarted = {0}", SessionStarted);
return sb.ToString();
}
}
Also I think there is one more problem. when i add breakpoint to init() method, after push F10 it goes to start of init() means there is other threads that try to run init() is it a problem?

Answer 1

HttpModules live in a pool. The ASP.NET process creates and initializes a (configurable) number of them when your app starts up and places it in a pool.
Then every time a request comes in an instance is taken from the pool and assigned to service the request. There is no initialization at this time. When the processing of the request is completed, the instance is placed back in the pool for later use.
Under heavy load the system can decide to create more instances of HttpModules
HTH

Answer 2

Maybe you are using Cassini and recompiling your application every time by hitting F5 which creates the illusion that the Init method is called on every request.