Re: [Qemu-devel] [PATCH 1/3] qmp/hmp: Add QMP getfd command that returns fd

["Daniel P. Berrange" <berrange@redhat.com>]

On Wed, Jun 06, 2012 at 10:04:23AM -0400, Corey Bryant wrote:
> 
> 
> On 06/05/2012 02:30 PM, Luiz Capitulino wrote:
> >On Mon,  4 Jun 2012 09:10:08 -0400
> >Corey Bryant<coreyb@linux.vnet.ibm.com>  wrote:
> >
> >>This patch adds QMP support for the getfd command using the QAPI framework.
> >>Like the HMP getfd command, it is used to pass a file descriptor via
> >>SCM_RIGHTS.  However, the QMP getfd command also returns the received file
> >>descriptor, which is a difference in behavior from the HMP getfd command,
> >>which returns nothing.
> >
> >I have a few comments regarding the qapi conversion below, but something
> >important to discuss is that returning an int the way you're doing it is
> >certainly incompatible.
> 
> Thanks for your feedback.
> 
> >
> >Today, we return a dict on success:
> >
> >  { "return": {} }
> >
> >But this patch changes it to:
> >
> >  { "return": 42 }
> >
> >There are two ways to do this without breaking compatibility:
> >
> >  1. Add a new command (say get-file-descriptor)
> 
> What do you think about using getfd2 for the command name?  I'm
> thinking getfd2 may be more obvious that it corresponds to closefd.
> That assumes we'll use the same array internally to store fds and
> closefd can be used to close the fd opened by
> get-file-descriptor/getfd2.

How about calling it 'passfd' instead ?  I have always thought
the name 'getfd' to be a little wierd really, since we're not
getting an FD from QEMU, we're passing it one that we have.

Regards,
Daniel
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