Re: IM33: Modifying and/or sending messages received

From: Stickley, John <john_stickley@mentorg.com>
Date: Wed Nov 10 2004 - 06:35:22 PST

Per,

Bojsen, Per wrote:

> Hi John,
>
> > I carefully reviewed this thread and thought about it a bit.
> > One thing I think we still want to do is keep SceMiMessageData
> > construction and re-use to be something managed by the user.
>
> And this implies you believe reuse of input messages at least
> should be allowed, right?

johnS:
Absolutely !

>
> > On the one hand, I think this would be useful to receive
> > an output message and within the same receive callback function
> > tweek a couple of fields and turn it right around and send
> > back to H/W on an input port.
>
> While this could be useful, the definition of the receive callback
> strongly suggests modifying the message is not supported due to
> the const message argument. Of course, there will be implementations
> that would allow casting away const'ness and modifying the message,
> but that would be non-portable. So it seems we are forced to
> accept that the standard does not condone modifying output messages
> and given that, reuse of output messages have limited value. After
> all, one can always copy the contents of the message to another
> one. In fact, we could define a SceMiMessageData copy constructor
> to make it convenient for the user.
>
> So it seems to make sense to ban reuse of output messages which gives
> implementations that extra degree of freedom in choosing message
> internals.

johnS:
I'm OK with this. You're right, that was the intent of putting const
there.

<eom>

>
> Per
>
> --
> Per Bojsen Email: <bojsen@zaiqtech.com>
> Zaiq Technologies, Inc. WWW: http://www.zaiqtech.com
> 78 Dragon Ct. Tel: 781 721 8229
> Woburn, MA 01801 Fax: 781 932 7488
>

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Received on Wed Nov 10 06:36:13 2004

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