Re: [Discuss] Make a thinner Glib/GTK+ to fit tiny device better

[cee1 <fykcee1 gmail com>]

2015-10-17 1:26 GMT+08:00 Emmanuele Bassi <ebassi gmail com>:
> Hi;
>
> On 16 October 2015 at 18:15, cee1 <fykcee1 gmail com> wrote:
>
> > The idea here is trying to make a thinner event loop.
>
> You keep using that word, "thin". I don't think it means what you
> think it means.
>
> You have consistently failed to bring any measurement, or any metric,
> that would allow you (or anybody else) to identify what's the current
> state of GLib, and how would we identify a "thinner" version of GLib.
>
> Saying that you want a "lightweight" version of GLib is pointless, if
> you also don't define a system of measurement that defines what
> "lightweight" even means.
Yeah, a profile/measurement is necessary when discuss '*thin*'. While
on the other hand, IMHO, comparing similar libraries which deploying
different approaches may inspire some ideas. Here, as an example: the
COW approach to remove duplication, a simpler event loop ...

Quite frankly, GMainLoop seems a little complicated to me, especially
compared with the event handling in GCD[1]. Hence, I'm wondering
whether I can combine an external event loop without GMainContext
involved.


> > I'm wondering is it a thinner and cleaner implementation, that
> > GTK+/GIO/etc provide hooks and let client or utility/glue library use
> > these hooks to put GTK+/GIO/etc into their event loop.
>
> The idea is to have a fd-based interface that lets you extract a
> (pollable) descriptor from GMainContext, and additional main loops can
> poll on that; see the (lengthy) discussion on:
> https://bugzilla.gnome.org/show_bug.cgi?id=699132
Thanks for pointing out this patch out :)

In this patch, the iteration of the event loop is
poller->funcs->iterate(), take epoller as an example, which will then:

1. Invoke g_main_loop_prepare_poll() to invoke GSource.prepare, and
notify epoller to update epoll_fd through "add_fd / modify_fd /
remove_fd" in context_update_poller().

2. Do epoll()

3. Invoke g_main_loop_process_poll() to run GSource.check and GSource.dispatch.

It is a big step to utilize scalable event loop implementation, while
still a little complicated...



---
1. https://github.com/cee1/cee1.archive/blob/master/documents/libdispatch-event.pdf

- Regards,

cee1