qio: introduce qio_channel_add_watch_{full|source}

Firstly, introduce an internal qio_channel_add_watch_full(), which
enhances qio_channel_add_watch() that context can be specified.

Then add a new API wrapper qio_channel_add_watch_source() to return a
GSource pointer rather than a tag ID.

Note that the _source() call will keep a reference of GSource so that
callers need to unref them explicitly when finished using the GSource.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2 files changed