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

[Mathieu Bouchard]

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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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal, Québec