1 Reply Latest reply on Apr 4, 2008 6:26 AM by Newsgroup_User

    Locking and Objects

    josheby Level 1
      I have been looking up a lot of information on locking shared-scope variables lately, because I dont really do it at all and I probably should. My question revolves around something else I had posted about a couple of days ago about creating objects in the session scope.

      I have user.cfc that holds information such as username. etc... I have methods such as getFirstName(), getLastName(), and setUser(userID). These variables are references as #Session.User.getFirstName()# as expected.

      My question is, since this is a session variable... should it be locked before access?
        • 1. Re: Locking and Objects
          Level 7
          jeby wrote:
          > My question is, since this is a session variable... should it be locked before
          > access?
          >

          Probably not very often. You should not have to do a lock when you are
          just reading values. And you would only need to do a lock when changing
          a value in your object if you are concerned about race conditions.
          Which for session variables are relatively rare.

          If you where dealing with an object stored in the Application or Server
          scope then there would be a much greater chance for race conditions to
          occur. Thus you would generally be more concerned about locking
          modifying code for these types of objects.

          In early versions of ColdFusion there where memory leak problems with
          these persisted scopes and the work around was to always lock every
          thing. This issue has long been resolved, but the old cannon of locking
          all the time still persists.

          But there can be serious performance, scalability and throughput issues
          to over locking your application. So the better pratice is to only lock
          when there is a reason to lock.