How can I push data to a user session?

I need to push changes to my app's session scopes in real time. Each user in session in my app has a similar struct to this:

session.user = 
{
   name = "Foo",
   mojo = "100"
};

Users can modify each others' "mojo." For example, if user Foo received 10 mojo points, and he now has 110, I need to update his session.user.mojo to reflect the additional "mojo" received. I need to modi开发者_StackOverflow中文版fy his session struct, in other words.

Example 2: User in session 1 does something where user in session 2 receives "mojo." The session.user.mojo in session 2 needs to be updated to reflect this change.

Some info:

1. The inital mojo value is pulled from the database and stored in the session when a user logs in.

2. "Mojo" updates always take place in the database. "Mojo" stored in the session is used to govern user privileges.

What are my options? Is this even possible? I have absolutely no idea on how to do something like that.

UPDATE I don't want pass the updated values back to the user (the data will refresh when the user navigates between pages). I only want to change them in the appropriate user's session scope.

This answer is ColdFusion 9 specific.

Cache user data (e.g. cachePut()) by user ID, and keep track of their user ID in session. Every update to mojo should retrieve the user data in cache - if present - and update it there as well. Finally, if this is a multi-server environment, setup messaging between the machines that broadcasts the user ID of any change to mojo, servers receiving the message then update their own cached user data.

What this buys you is limiting the amount of database activity that goes on, pretty good liveness, and makes the mojo value available globally, which has the added benefit of being available for purposes other than the user session (e.g. another user can review their profile to see the mojo score).

If you really need to change vars in a particular Session, there's no built-in way to do that. Maybe you can abstract out the logic, instead of accessing the mojo from Session, always access mojo from DB?

update: Why session? How about a big struct in Application scope, and use userID or sessionID as key, and mojo as value? You can also store a timestape like lastUpdated and delete the ones that has not been updated to reclaim your memory. Then from time to time, update your DB? Or... update your DB async if u're worry about performance.