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Date: Wed, 16 Mar 2011 13:06:54 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: Re: [Qemu-devel] Re: [PATCH 00/15] QAPI Round 1 (core code generator)
	(v2)
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>, Avi Kivity <avi@redhat.com>, Adam Litke <agl@us.ibm.com>, Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org

On 03/16/2011 11:31 AM, Paolo Bonzini wrote:
> On 03/16/2011 05:03 PM, Anthony Liguori wrote:
>> So for an event, you just need to do:
>>
>> { 'signal': 'vnc-connected', 'data': { 'client': 'VncClientInfo' } }
>>
>> And you can add new fields to the VncClientInfo structure as much as
>> you'd like without worrying about breaking the C ABI.
>
> So why couldn't you automatically wrap the events data field in a 
> structure (e.g. vnc-connected events receive a VncConnectedEventData*)?

You could, but is it really necessary or even useful?

I don't see signals as being any different than function calls.  You 
could do the same thing for function calls.

A good example is the vnc-connected event.  I didn't post the full 
event, it's reall:

{ ' signal': 'vnc-connected', 'data': { 'client': 'VncClientInfo', 
'server': 'VncServerInfo' } }

You could add an automatic structure around these two members but that 
makes the C interface quite a bit more awkward for no obvious gain.

Regards,

Anthony Liguori

> Paolo
>