Re: [Vala] Bug in async methods?

[rastersoft <raster rastersoft com>]

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I've been watching the source code generated by Vala and the key is here:

    _data_->result = 1;
    if (_data_->_state_ == 0) {
        g_simple_async_result_complete_in_idle (_data_->_async_result);
    } else {
        g_simple_async_result_complete (_data_->_async_result);
    }

What do you think about a decorator or something similar to allow to use
async functions without main loop, just using always
g_simple_async_result_complete() in those cases?

I ask this because I'm using Vala to do simulations, using an
architecture similar to SimPy (this is, based on async methods) and it
would be much more convenient to be able to work that way in those cases.

El 23/10/12 00:22, Jim Nelson escribió:
> It would take me a bit of time to explain async (I've thought about blogging about it), but the short
answer is: Vala's async and yield keywords are designed to use MainLoop
to schedule code execution.
> You don't *have* to use them to do asynchronous work, but they are
certainly convenient.
> -- Jim
>
> On Mon, Oct 22, 2012 at 3:19 PM, rastersoft <raster rastersoft com> wrote:
>
> Yes, you are right: I created a main loop, called run(), and the
callback got called.
> Anyway, I don't understand why is not possible to ensure that the end
callback gets called even without a main loop :?
> Thanks!
>
> El 23/10/12 00:03, Jim Nelson escribió:
> > For async to work properly, you
> must run the GLib MainLoop. MainLoop is where your async closure
> for test_function.begin() is called. It's where all callbacks are
> scheduled, actually.
>
>
>
> > The only reason this works is that in the case of DO_YIELD
> you stash the test_function.callback and then call it back. That's
> why you're seeing "End callback called 1".
>
>
>
> > A better way to do this is to (a) get rid of ext_callback and
> (b) call "new GLib.MainLoop().run()" right before the "return 0"
> in main(). Without actually modifying the code (i.e. I'm doing
> this off the top of my head), that should work.
>
>
>
> > -- Jim
>
>
>
> > On Mon, Oct 22, 2012 at 2:47 PM, rastersoft
> <raster rastersoft com> wrote:
>
>
>
> > Hi all:
>
>
>
> > I was working with async methods, and found something odd: if
> I call an
>
> > async method, but, for whatever reason, I never call YIELD
> inside, the
>
> > end callback function is never called.
>
>
>
> > I attach an example: by compiling it with
>
>
>
> > valac -D DO_YIELD -o test_async test_async.vala --pkg=gio-2.0
>
>
>
> > will do a YIELD inside the async function. But when compiled
> with
>
>
>
> > valac -o test_async test_async.vala --pkg=gio-2.0
>
>
>
> > will not. In the former case you can see how "End callback
> called 1" is
>
> > printed, because the callback for the end is called; but in
> the later,
>
> > it's not printed.
>
>
>
> > Is that a bug? If not, why does it work that way?
>
>
>
> > Thanks.

- -- 
Nos leemos
                 RASTER    (Linux user #228804)
raster rastersoft com              http://www.rastersoft.com

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