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From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <8d991abc-a37e-8e6f-68fc-6e3bd52bd98a@redhat.com>
Date: Fri, 2 Mar 2018 16:53:19 +0100
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Subject: Re: [Qemu-devel] [PATCH v2 03/15] qio: introduce
 qio_channel_add_watch_{full|source}
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To: "=?UTF-8?Q?Daniel_P._Berrang=c3=a9?=" <berrange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>, qemu-devel@nongnu.org, Juan Quintela <quintela@redhat.com>, =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= <marcandre.lureau@redhat.com>, Markus Armbruster <armbru@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, "Dr . David Alan Gilbert" <dgilbert@redhat.com>

On 02/03/2018 16:44, Daniel P. Berrang=C3=A9 wrote:
>> Just a small thing, this is a bit inconsistent with the rest of the
>> GSource API, where the g_source_attach is usually left to the caller
>> when a function returns GSource *.
> The APIs which return a GSource in glib typically don't even set the
> callback function - we already cover that scenario with the
> qio_channel_create_watch APIs.
>=20
> GLib doesn't typically have APIs which return a GSource after the
> mix of creating the watch, setting callback & attaching to context.

True, on the other hand it's annoying for qio_channel_create_watch
because of the function pointer case.  So I suggested a mix of creating
the watch and setting the callback.

Having a function that takes a GMainContext and returns a tag is fine, to=
o.

Paolo

> They all just return the watch ID value.
>=20
> So I think this proposal is ok as it is as there's no real precedence.
>=20
> Alternatively we could simply do without this API entirely. It is
> trivial enough for the code that needs a GSource to get iuse the
> normal qio_channel_add_watch|watch_full APIs, and then lookup the
> GSource themselves - only one extra line of code in the callers.