Re: 01/02: Re-implement (ice-9 streams) in terms of (srfi srfi-41)

[Ludovic Courtès]

Mark H Weaver <address@hidden> skribis:

> address@hidden (Ludovic Courtès) writes:
>
>> Perhaps the right thing would be to just fix SRFI-45 promises to be
>> thread-safe, no?
>
> This would slow down the fastest implementation of promises we could
> hope for by an order of magnitude, at least on non-Intel platforms.
>
> This in turn would severely limit the set of applications for which
> SRFI-45 promises and SRFI-41 streams would be efficient enough to
> consider.

Good point.

The other side of the problem is that non-thread-safe promises also
limit the set of contexts they can be used in.  (I remember relying on
the fact that core promises were thread-safe quite a few times.)

Anyway, I withdraw my suggestion.

BTW, I just realized that core promises use fat mutexes, which is
unfortunate.  Using plain pthread mutexes would make them faster, and
costing nothing in single-threaded programs on glibc systems.  Perhaps
that’s something we should try?

> If most of the Guile community wants to persue this strategy of building
> thread synchronization into primitives that could otherwise be extremely
> cheap, then I'd better withdraw from this community.

Mark, please let’s assume good faith and avoid gratuitous confrontation.
Clearly, in this case, we are focusing on different concerns of the
matter, and that is fine.

Last month Andy attempted to start the port thread-safety discussion
again explicitly asking for your feedback, and thinking about ways to
move forward:
<http://lists.gnu.org/archive/html/guile-devel/2015-02/msg00010.html>.
I think there’s a chance we could take into account both the concerns
that Andy raised and those that you raised, so let’s not miss it.

Thanks,
Ludo’.