Re: Paralellizing Lilypond [was: Re: Sibelius Software UK office shutsdown]

[Han-Wen Nienhuys]

On Sat, Aug 11, 2012 at 9:21 AM, Joseph Rushton Wakeling
<address@hidden> wrote:
>>> What counts as a "chunk" for the -djob-count option?  It's not clear from
>>> the
>>> 2.15 usage manual.
>>
>>
>> I believe it would be a compilable file.
>
>
> Useful to know, thank you!
>
> ... but I think it emphasizes my real point: this puts the onus on the user
> to split up a project into independently-compilable units.  I think that
> it's worth having Lilypond try and automatically identify independent units,
> which could have knock-on benefits in terms of minimizing rebuild times for
> scores.

It would be nice if this were automatically splittable, but the
reality is that GUILE has no meaningful multithreading support at the
interpreter level, so almost mutating operation has the potential to
be a race condition.

Short of rewriting LilyPond from scratch, I don't see how we can get
parallelism within a file; that doesn't stop you from inventing
something that uses includes and some preprocessing to render
subsections of a melody, and then stitch the result together in a
postprocessing phase.

--
Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen