2009/10/8 Kassen <signal.automatique@gmail.com>

...When the shred a UGen was defined in exits the UGen will be disconnected from anything it connected to (I'm not sure everything that connects to the Ugen on the other end will also be disconected but that doesn't matter much here). Because of this the DAC will no longer poll it for new samples so it won't take any CPU anymore. This, in adition to calculation order, is the big advantage of the "pull through" model we use for the UGens.

Here's a simple program that defines a SinOsc and plays it in its own shred. After 3.5 seconds, the shred is killed (and we know that it has exited since its heartbeat / printing stops), yet the sound plays on.
=============
fun void playit() {
    SinOsc s => dac;
    while (true) {
    <<< now / 1::second, "playing..." >>>;
    1::second => now;
    }
}

spork ~ playit() @=> Shred @ _player;
3.5::second => now;
<<< now / 1::second, "terminating shred..." >>>;
_player.exit();
<<< now / 1::second, "waiting before exiting" >>>;
7.5::second => now;
<<< now / 1::second, "exiting!" >>>;
============
produces
bash-3.2$ chuck ~/Projects/Chuck/Tests/shred_exit.ck
0.000000 playing...
1.000000 playing...
2.000000 playing...
3.000000 playing...
3.500000 terminating shred...
3.500000 waiting before exiting
4.000000 playing...
11.000000 exiting!
===========
[Digression: why the heck does playit() print out "4.00 playing..." when it was terminated at t=3.5? That may be because an exit() doesn't take effect until the next time a shred blocks. If so, that would be a nice thing to document.]

I think what you meant was "When the shred a UGen was defined in exits *NORMALLY* the UGen will be disconnected from anything it connected to..." To test that, we simply let the player shred exit (without unchucking the dac):
===========
fun void playit() {
    SinOsc s => dac;
    <<< now / 1::second, "playit playing" >>>;
    1::second => now;
    <<< now / 1::second, "playit exiting" >>>;
}

spork ~ playit();
7.5::second => now;
<<< now / 1::second, "finished" >>>;
===========
And yep, sure enough, the sound stops after 1 second.

So the moral of the story: if you terminate a shred via exit(), it does NOT get the benefit of a standard shred clean-up.

Perhaps "cleanup of a terminated shred" should be added to the someday-nice-to-have wish list.

Cheers,

- Rob