Re: [Qemu-devel] [PATCH] event_notifier: move to top-level directory

[Anthony Liguori]

On 09/27/2011 10:28 AM, Jan Kiszka wrote:
> On 2011-09-27 17:17, Stefan Hajnoczi wrote:
> > On Tue, Sep 27, 2011 at 3:26 PM, Avi Kivity<address@hidden>  wrote:
> > > Has no business in hw/.
> > >
> > > Signed-off-by: Avi Kivity<address@hidden>
> > > ---
> > >   hw/event_notifier.c =>  event_notifier.c |    1 -
> > >   hw/event_notifier.h =>  event_notifier.h |    0
> > >   2 files changed, 0 insertions(+), 1 deletions(-)
> > >   rename hw/event_notifier.c =>  event_notifier.c (98%)
> > >   rename hw/event_notifier.h =>  event_notifier.h (100%)
> >
> > Yay.  Now perhaps we can kill qemu_eventfd(), whose users are
> > typically poking around with write(2) and read(2) when really they
> > could use the high-level event_notifier.h API.
>
> EventNotifiers will have to be superseded by something more generic
> first. It's not fully covering the use cases of cpus.c and
> posix-aio-compat.c.

Actually, for posix-aio, we can just switch to using g_idle_add().  g_idle_add() 
uses g_source_attach which is thread safe.  g_idle_add() gives you a thread safe 
mechanism to defer a piece of work to the main loop which is really what we want 
here.

This can actually be made to work with sync I/O emulation too by having another 
GMainLoop in the sync I/O loop although I thought I recalled a patch series to 
remove that stuff.

Kevin/Stefan, what's the plans for sync I/O emulation?

See untested patch below.

Regards,

Anthony Liguori

> Jan

0001-posix-aio-compat-use-g_idle_add.patch
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