Re: [Qemu-devel] [RFC 0/9] QContext: QOM class to support multiple event loops

[Paolo Bonzini]

Il 06/05/2013 20:35, mdroth ha scritto:
> In the case of the former, I think a wrapper around GLib that we can
> instantiate from the command-line line and query properties like TIDs
> from is necessary for robust control over event loops and CPU resources.
> We get this essentially for free with QOM, so I think it makes sense to
> use it.
> 
> In the case of the latter I'm not too sure. Without the QSource
> abstraction there isn't much reason not to use the native GLib
> interfaces on the underlying GSources/GMainContexts directly. In which
> case GlibQContext would only need to be a container of sorts with some
> minor additions like spawning an event thread for itself.
> 
> If we ever did need to switch it out in favor of a non-GLib
> implementation, it should be a mostly mechanical conversion of
> GSource->QSource and adding some wrappers around
> g_main_context_prepare/check/etc.

I'm not sure it is that easy, but I agree entirely with everything else.

> Also along that line, if we're taking the approach of not adding
> infrastructure/cruft until we actually have a plan to use it, it probably
> makes sense to make QContext a concrete class implemented via GLib, and we
> can move the GLib stuff to a sub-class later if we ever end up with another
> QContext implementation.
> 
> Does this seem reasonable?

Yes, very much.

Paolo