Parallel Guile code called from parallel C code

Parallel Guile code called from parallel C code

[pablo]

Hello everyone,
I have a question about calling parallel Guile functions from a
parallel C program.

Suppose the situation is such that there is a parallel C program and
two threads which call Guile functions and that these Guile functions
use future to go parallel.

The Guile doc says "Internally, a fixed-size pool of threads is used
to evaluate futures, (...) the pool contains one thread per available
CPU core, minus one, to account for the main thread."

Then how does this work in the situation I described? Do the two
concurrent parallel Guile functions use threads from the same pool or
is there actually two pool? (ie. does each C threads calling a Guile
function have an independent Guile environment regarding the possible
parallelization of the Guile function itself?)


I'm not sure my question is very clear, sorry if it's not the case :-S.

Thanks!

--
Pablo.
http://pablo.rauzy.name/

Re: Parallel Guile code called from parallel C code

[Ludovic Courtès]

Hi,

pablo <r@uzy.me> skribis:

> The Guile doc says "Internally, a fixed-size pool of threads is used
> to evaluate futures, (...) the pool contains one thread per available
> CPU core, minus one, to account for the main thread."
>
> Then how does this work in the situation I described? Do the two
> concurrent parallel Guile functions use threads from the same pool or
> is there actually two pool? (ie. does each C threads calling a Guile
> function have an independent Guile environment regarding the possible
> parallelization of the Guile function itself?)

There’s a single thread pool per Guile instance.  See ice-9/futures.scm:
there’s a global variable holding a list of threads, basically.

HTH,
Ludo’.