Re: [Qemu-devel] [PATCH 03/14] qio: introduce qio_channel_add_watch_full()

[Daniel P . Berrangé]

On Wed, Feb 28, 2018 at 08:44:24PM +0800, Peter Xu wrote:
> On Wed, Feb 28, 2018 at 09:08:45AM +0000, Daniel P. Berrangé wrote:
> > On Wed, Feb 28, 2018 at 01:06:22PM +0800, Peter Xu wrote:
> > > It's a more powerful version of qio_channel_add_watch(), which supports
> > > non-default gcontext.  It's stripped from the old one, then we have
> > > g_source_get_id() to fetch the tag ID to keep the old interface.
> > > 
> > > Note that the new API will return a gsource, meanwhile keep a reference
> > > of it so that callers need to unref them explicitly.
> > 
> > I don't really like this. Having qio_channel_add_watch and
> > qio_channel_add_watch_full with differing return values is
> > really very surprising. They should be functionally identical,
> > except for the extra context arg.
> 
> Yeah it's not nice, but I do need the GSource and the tag ID does not
> help in the series.
> 
> An alternative would be that I modify qio_channel_add_watch() to
> return GSource too.  Is there an third choice that you could suggest?

Given you have the id + GMainContext you can just acquire the GSource,
if needed, using g_main_context_find_source_by_id.

Regards,
Daniel
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