On Fri, Nov 19, 2010 at 13:25:11 +0100, pancake wrote:
> you are using coroutines which are not designed to "run stuff in
> background".
>
> coroutines are designed to run collaborative code which hangs if one of the
> parts doesn't pass the token when necessary.
>
> You have to use threads, or an idle task if you have a mainloop.
Async methods are NOT coroutines(*). They ARE transformation of functions to
let them finish in response to an event in the main loop (idle or not).
Oh, and avoid threads as long as you can -- synchronization is a LOT of
trouble. And running another main loop in the other thread to get
spawn_async_with_pipes working there is even more.
> On 11/19/10 08:34, James Moschou wrote:
> >Hello,
> >
> >I want to perform a series of tasks one after the other, but in the
> >background. So I have:
> >
> >async bool perform_tasks () {
> > bool result = yield task1 ();
> > if (result)
> > result = yield task2 ();
> > if (result)
> > result = yield task3 ();
> >
> > Idle.add (perform_tasks.callback)
You can attach the .callback to any event source in the same way. So e.g.
when data arrive from the process or the child terminates etc.
> > yield;
> > return result;
> >}
> >
> >more or less.
> >
> >One of the tasks however spawns a new process, and I'm not sure how
> >the callback from this process is supposed to fit into Vala's way of
> >doing async programming, i.e. Process.spawn_async_with_pipes () isn't
> >actually an "async" method.
But it's easy to wrap it in one. Just spawn_async_with_pipes and arrange the
.callback to be called when results are available and yield.
(*) They are not coroutines, because they are not running in parallel with
the caller. The not yet implemented generator functions would be coroutines.
--
Jan 'Bulb' Hudec <[email protected]>
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