Re: [fluid-dev] [PATCH] sampledata caching

[Kjetil Matheussen]

On 10.10.2012 08:05, David Henningsson wrote:
> On 10/09/2012 11:13 AM, Kjetil Matheussen wrote:
> > Hi,
> >
> > I'm embedding FluidSynth as an instrument in the Radium music editor
> > (http://users.notam02.no/~kjetism/radium).
> >
> > It works fine (thanks for the great work!), but the memory usage was
> > sometimes shockingly high because fluidsynth reloads
> > entire soundfonts for every new synth, even if the soundfont was 
> > already
> > used in a different synth.
> >
> > Maybe I have misunderstood something, but instead of spending 
> > several
> > more hours trying to figure out if I had misunderstood
> > something, I modified fluidsynth to cache already loaded sampledata 
> > from
> > soundfonts.
> >
> > Here's the patch:
> > http://users.notam02.no/~kjetism/fluid_defsfont_patch.diff
> >
> > Please let me know if there's anything that's needed to do in order 
> > for
> > you to use it.
> >
> > I also have a question: Can delete_fluid_defsfont and
> > fluid_defsfont_load_sampledata be called from different threads at 
> > the
> > same time?
> > In so, we also need a lock protecting the global list of cached 
> > sampledata.
>
> Hi Kjetil and thanks for your patch!
>
> You're correct in your last sentence - as of how it works today, I'd
> say fluidsynth client software expects to be able to call
> fluid_defsfont_* in parallel. So yes, it needs to be protected.

Great, I'll fix that.

> Another thing we need to verify is that the sampledata is read-only
> once it's been bigendian converted. If it is not, chances are that 
> two
> threads would both modify the sampledata, causing problems.

Okay. I'll see if there's any trouble changing the sampledata field 
from short* to const short*.


> Element - you've been more into this part of FluidSynth than I, would
> you mind confirming that the sampledata is strict read-only and there
> are no hacks that change it?
>
> // David