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

[David Henningsson]

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.

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.

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