[Qemu-devel] Re: [PATCH] QMP: Emit asynchronous events on all QMP monitors

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 15 Jan 2010 08:34:02 -0600
Adam Litke <agl@us.ibm.com> wrote:

> When using a control/QMP monitor in tandem with a regular monitor, asynchronous
> messages can get lost depending on the order of the QEMU program arguments.
> QEMU events issued by monitor_protocol_event() always go to cur_mon.  If the
> user monitor was specified on the command line first (or it has ,default), the
> message will be directed to the user monitor (not the QMP monitor).
> Additionally, only one QMP session is currently able to receive async messages.
> 
> To avoid this confusion, scan through the list of monitors and emit the message
> on each QMP monitor.
> 
> Signed-off-by: Adam Litke <agl@us.ibm.com>
> 
> diff --git a/monitor.c b/monitor.c
> index 134ed15..06c8bf0 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -334,13 +334,10 @@ void monitor_protocol_event(MonitorEvent event, QObject *data)
>  {
>      QDict *qmp;
>      const char *event_name;
> -    Monitor *mon = cur_mon;
> +    Monitor *mon;
>  
>      assert(event < QEVENT_MAX);
>  
> -    if (!monitor_ctrl_mode(mon))
> -        return;
> -
>      switch (event) {
>          case QEVENT_DEBUG:
>              event_name = "DEBUG";
> @@ -373,7 +370,12 @@ void monitor_protocol_event(MonitorEvent event, QObject *data)
>          qdict_put_obj(qmp, "data", data);
>      }
>  
> -    monitor_json_emitter(mon, QOBJECT(qmp));
> +    QLIST_FOREACH(mon, &mon_list, entry) {
> +        if (!monitor_ctrl_mode(mon))
> +            return;
> +
> +        monitor_json_emitter(mon, QOBJECT(qmp));
> +    }

 The function will return on the first !QMP Monitor, the
right QLIST_FOREACH() body is:

if (monitor_ctrl_mode(mon)) {
 monitor_json_emitter(mon, QOBJECT(qmp));
}

 I'll ACK the respin.

>      QDECREF(qmp);
>  }
>  
> 
>