Re: Using OMS from Carbon under OS9
Re: Using OMS from Carbon under OS9
- Subject: Re: Using OMS from Carbon under OS9
- From: Jeff Evans <email@hidden>
- Date: Thu, 24 Oct 2002 20:58:23 -0700
Kurt et al:
Even with the Carbon Event model there are responsiveness problems under
OS9 with Virtual Memory- for musical purposes at least. QuickTime has a
palpable delay in response if VM is on, regardless of event model. There are
no such problems to speak of under OSX, even though in effect VM is always
on there. So the Carbon Event model doesn't seem to help in this regard,
under OS9.
For me it's too late to defer a "full" transition to Carbon - that's
done. But I think that as a general principle it would be good to have a
general, agreed-upon, standard and government-approved way to use Apple's
official OS9 MIDI system - OMS - from Carbon.
Yours, Jeff
>
on 10/24/02 6:58 PM, Jeff Evans <email@hidden> wrote:
>
>
> Welll, I don't know - Carbonizing the project caused changes throughout; a
>
> whole lot of structural changes to use the Carbon events model and much
>
> more, and in this case there are a lot of new features folded into the
>
> Carbonized version. I think most people are going to find it impractical to
>
> maintain two separate piles of source code for Carbon and non-Carbon; if
>
> that's the least pain we're in trouble.
>
>
Maybe it is possible to defer that transition to "full" Carbon until you are
>
willing to discontinue OS 9 support? I for one am using my pre-carbon event
>
code in my non-carbon, carbon CFM, and carbon Mach-O builds. I am kind of
>
stuck here for now because I am somewhat committed to PowerPlant, which has
>
not yet gone to the carbon event model.
>
>
I know that my event handling is less cpu efficient as a result, but not
>
enough to create any problems with midi or audio functionality (as far as I
>
can tell). Using the enhanced (non-polling) mouse tracking calls instead of
>
StillDown etc is perhaps the only semi-obligatory difference for carbon
>
verus non. I would be curious about other people's experience or advice
>
here. (I have not yet tested on a single-CPU system.) Various
>
responsiveness problems that I was experiencing some months back seem to
>
have dissappeared with Jaguar, and I attribute that to the changes in
>
thread/priority standards that took place.
>
>
> On the other hand, it's easy to compile specifically separate Mach and
>
> OS9 products using the same Carbon source, so that the Mach build has access
>
> to CoreMIDI. The changes for the non-Mach version are trivial except for
>
> this OMS issue.
>
> I haven't figured out the shared library approach yet & I still wonder
>
> if it really would float. Has anyone actually done that? Doug suggests it;
>
> another correspondent is starting to try it.
>
>
>
> Jeff
>
>
>
>
>
>> The least pain approach is to build two different versions of the
>
>> program: One non-Carbon for OMS and one Mach-O...
>
>>
>
>>> Sorry that I jumped right from the pre-Carbon world to writing
>
>>> everything Mach-O native on X and don't have any experience with
>
>>> Carbon development on 9.
>
>>>
>
>>> I know there's a way others have done this, but I don't know what it
>
>>> is. It might involve packaging the OMS glue into a shared library.
>
>>>
>
>>> Doug
>
>>>
>
>>>
>
>>> On Thursday, Oct 24, 2002, at 11:55 US/Pacific, Jeff Evans wrote:
>
>>>
>
>>>> And a request: Solving the MIDI problem for OS9 is pretty important for
>
>>>> apps that have a large customer base still using 9 but want to become
>
>>>> compatible with X. It would be great if Apple could provide some sample
>
>>>> code for accomplishing this trick - with the author of OMS present at
>
>>>> Apple
>
>>>> perhaps this is not too unreasonable a hope?
>
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