Re: [Vala] Bug in async methods?

[Jim Nelson <jim yorba org>]

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:

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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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