Changes to the listen event.

I am giving a heads up to everyone that I have made modifications to the listen event on the test servers (not live yet). Messages can now only trigger one listen event, even if they match the criteria for more than one listen callback. For example:

default
{
    state_entry()
    {
        llListen(0, "", "", "");
        llListen(0, "", llGetOwner(), "");
    }

    listen(integer channel, string name, key id, string mesg)
    {
        llSay(0, name + ": " + mesg);
    }
}

Currently, if the owner says something, both callbacks would match and the listen event would be fired twice. With the new changes, the listen event would just trigger once.

Is anyone relying on the current behavior? I can't think of a good reason to have the listen event trigger more than once for any given message, but I'm just giving out a heads up just in case. =)

Don,
Thanks for the advanced notice. I can't think of any reason to trigger listen() more than once, but I am constantly amazed at all of the great scripts people come up with. At any rate, keep up the great work, thanks again for the heads up, and when do you expect the listen changes to be moved to production?

McW

Most likely in 1.5.6

Good change. I've been bitten by this before.

Once again, Don knows what we want and makes it so.

Where's the llRezObjectRight function, Don?

Tiger: In 1.5.6 =D

Thanks for the heads up Don. Personally, I don't mind either behaviour and I don't rely on either.

I assume you're making this change as an optimization. I do have a question, though.

It's common belief that an excessive number of listeners causes lag. I hear that this behaviour was significantly improved in 1.5, although I have not personally verified it.

Many people, including myself, often write/re-write scripts to minimize the number of listeners we use (ie. have a listener script and pass listen events to other scripts via link messages), but this often comes at the price of simplicity and modularity.

Is this practice now obsolete?

That's a really good question, Francis. What's easier on the sim, Don, two llListens, or an llListen with an IF/ELSE?

WOOHOO

You da man, Don!

Don,

I like this change.

I can't think of any example of why people would need this, that couldn't be solved by moving around / copying procedures.

Sounds good to me. No problem here. Thanks Don!

What about Francis' question? People have bounced around that question for a long time.

Awsome, thank you so much for the heads up on this. I myself don't rely on the current way it works and actualy would find that annoying to happen.

So I'd so go ahead and change it.

Any situation that would call for someone to use more than one Listen, could and probably should be done with if statments within the listen event instead.

I too am curious about Francis' question.

I'm not sure if this is valid but I'm gonna throw it out there anyway.

What about new scripters who accidentally open multiple llListens? Without the result duplicating is there anything to indicate to them that they have too many listens open (which eat up server resources)?

I know that once a certain ammount of listens are opened an error occurs, but if this limit isn't reached then there would be no indication of wasted resources.

FWIW, this wont break any of my code, I think.

Azelda

Makes sense to me and I have no problems with it.

Not that I have many scripts running in SL, (I do have a few)... this would not negatively impact me.

Hammer down!

Great idea, but Rysidian has a valid point I think.



currently, there seem to be a lot of people scripting who don't know how to use llListen. My suggestion is that if you do this there should also be a corrisponding addition of...

llGetNumberOfListens()
or
llGetListenList()
or
llListenRemove(-1) //Remove All Listens.

llListenRemove( LISTEN_ALL ); or similar would be rather nice.

Azelda

agreas with Rickard Roentgen & Azelda Garcia

Gladly Welcomed