One way to get around the "shreds killing their children" (oh my God the children!) problem could be to have some main sporker shred that's always running and then use a queue and an event like this:

Event sporkEvent;

sporkableQueue;

fun void sporker() {

Sporkable @ sporkable;

while(true) {

sporkEvent => now;

sporkableQueue.popFirst() @=> sporkable;

while (sporkable != null) {

spork ~ sporkable.main();

}

}

}

spork ~ sporker();

fun void sporkShred(Sporkable @ sporkable) {

sporkableQueue.addLast(sporkable);

sporkEvent.signal();

}

...so instead of sporking directly you call sporkShred(sporkable), some instance of a subclass of Sporkable with a suitable main() implementation. Of course you need to implement the queue as well.

/Stefan

On Sat, Aug 30, 2008 at 5:28 AM, mike clemow <gelfmuse@gmail.com> wrote:

Actually, I should tell you all that I took a look at my code from the past week and it's a heinous example of software design.  While I'm rewriting this travesty, I leave open the question about methods of managing concurrent processes in Chuck.

Cheers,
Michael

On Fri, Aug 29, 2008 at 7:01 PM, mike clemow <gelfmuse@gmail.com> wrote:

Hi everyone,

So, I've been struggling to find a method to leverage the concurrency model in Chuck and I keep running up against the same issue: my guts tell me to do things that I can't do because of fact that child processes are alive only as long as the parent and the fact that objects are only passed by reference.

Let me unpack this for you.  I'm building a granular synthesis class library for Chuck.  Most everything is being cast as one of two types of objects:

1) Forkable - a process that takes parameters and can be run or sporked 
2) Forker - an object that knows how run a process and will fork it out for you.

In order to get over the fact that functions are not (yet) datatypes in Chuck which can be passed to other functions, I'm basically following the example that Kassen, Mike, et al. were discussing in this forum topic:

http://electro-music.com/forum/viewtopic.php?highlight=functor&t=23546

My problems always seem to rise from the fact that every Forker (whose job it is to fork a process) also has to be aware of how long that process is going to take or else run the risk of dying before it's child has completed.  This leads to infinite passing of responsibility for time and every Forker seems to also need to be a Forkable and have it's own Forker, et cetera ad inifinitum.  At higher and higher levels of abstraction, finding the duration of a process BEFORE it runs and figuring out how to handle it, is requiring more and more analysis and feels...  for lack of a better word, "wrong" to me.

This is compounded by the fact that the objects I'm passing into these functions (methods of other objects) can only be passed by reference and it's increasingly difficult to set-and-forget these processes, since they constantly reference other global objects.  The passing by reference is fine, but I find myself wishing I had the choice to make a copy.

Now, it's entirely probable that I just haven't caught on yet and am going about this process in a completely backward way.  Does anyone here run into similar issues and (even better) have good methods of avoiding them?

One idea I have considered is to make a Forker a looping process that receives Events as input, rather than an object with methods.  As this would require a(nother) complete re-write, I'm stalling.  ;-)

So, how do you manage your concurrent processes in Chuck?

Cheers,
Michael

PS: Love dynamic Arrays!  Can't wait for those SC/Smalltalk-like array methods!


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