[PD-dev] Using PD funcs from inside a threaded external

[B. Bogart]

Thanks for all the comments.

I'm now added wrapped outlet calls with sys_lock() and sys_unlock().

The reason I was getting a constant segfault in listconfig (and not in
the other functions) was that I was calling the thread function, not the
wrapper!

So I've checked gphoto into svn, under "bbogart".

Lots of extra features to add, but this is a decent base that allows a
linux user to control a supported PTP camera from PD.

Should I put a sys_lock() and sys_unlock() for each post() and error() call?

Feel free to tinker with it, writing the "TODO" now.

.b.

Mathieu Bouchard wrote:
> On Thu, 19 Mar 2009, B. Bogart wrote:
>> Mathieu Bouchard wrote:
>>> Afaik, this will do the rough equivalent of a [delay 0] across threads,
>>> so that your (Ben's) thread's execution is inserted between two t_clock
>>> events ([delay], [metro], etc.)
>> Does this mean that rendering/audio in PD will be interrupted during
>> this time of global locking?
> 
> Well, in the same way that when a [delay] or a [metro] outputs a bang it
> "interrupts" the rendering. But those events are never nested nor
> overlapping in real time, so a block always finishes computation before
> something else happens, and a message sent from [delay] always gets
> "fully processed" before something else happens, and so on. It wouldn't
> be much different from what you'd get if you turned the 2nd thread into
> a separate server that you'd communicate with using [netsend], really.
> 
> The only thing is that sometimes, pd runs in the 2nd thread, but that
> doesn't make so much of a difference, as pd is then not running in the
> 1st thread at the same time. The question is not which thread is in use,
> but how many of them at a time.
> 
> Replacing the lock by a message queue could have had some advantages,
> but it's more work.
> 
>> Ah! I would only need to lock while before I do the PD calls right?
>> sys_lock();
>> outlet_symbol();
>> sys_unlock();
>> ?
> 
> Exactly.
> 
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