🚀 go-pugleaf

Hi all ,

I have a class like this , for controlling user access in our ASP.NET
application.

////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////
using System.Collections;
using System.Threading;

public class LoggedInUserManager
{

 private static Hashtable _loggedUsers  = new Hashtable();

 private static ReaderWriterLock _readWriteLock   = new ReaderWriterLock()

 private const int WAIT_TIME = 10000 ;


 public static void AddUser(int usn, string sessId  )
 {
  _readWriteLock.AcquireWriterLock(WAIT_TIME);
  try
  {
   if ( _loggedUsers.Contains(usn))
   {
    _loggedUsers.Remove(usn);
   }
   _loggedUsers.Add(usn, sessId);
  }
  catch{}
  finally
  {
   _readWriteLock.ReleaseWriterLock();
  }

 }



 public static void RemoveUser(int usn )
 {
  _readWriteLock.AcquireWriterLock(WAIT_TIME);
  try
  {
   _loggedUsers.Remove(usn);
  }
  catch{}
  finally
  {
   _readWriteLock.ReleaseWriterLock();
  }

 }



 public static bool CanContinue(int usn , string  sessionId  )
 {
  bool  result ;
  _readWriteLock.AcquireReaderLock(WAIT_TIME);
  try
  {
   result = _loggedUsers.Contains(usn) &&
_loggedUsers(usn).Equals(sessionId);
  }
  catch{}
  finally
  {
   _readWriteLock.ReleaseReaderLock();
  }
  return result;
 }


}
////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////

This class is used to restrict a user logging in to the system
simultaneously.
If he tries so , his first session will be reset.

There can be maximum 150 users in our site at a time. They usually loggin at
morning and logoff at evening.
 So there will be a minimum 300 (AddUser() & RemoveUser()) updations for the
_loggedUsers collection
and  indefinite number of reading of the _loggedUsers collection. (On each
page load CanContinue() is called ).

I want to know , is there any pitfalls in the above class  ?
How we can avoid them ?
Any alternate solution ?  (Initially we were using Application.Lock() , but
Marc told me that it will lock the entire application object , we are
looking for alternatives.)
Pls give your valuable suggestions.

Thanks in advance.

Regards
        Sunil