[pypy-dev] pypy paris sprint report day 3.25

[Michael Hudson]

After the excrutiatingly entertaining consortium meeting/break day
yesterday, we resumed this morning with a status meeting.

The stackless group reported good progress, having compiled a working
pypy-c with stackless support and implemented stack overflow detection
for non-stackless builds.  Unfortunately for the stackless builds,
several CPOython tests expect infinite recursion to result in an error
-- and do so fairly quickly, i.e. in less time than it takes to fill
the entire heap with stack frames.  This group's work is basically
done for this sprint, although Anders and Christian are going to work
on compliancy testing with the new pypy-c.  While waiting for builds
targeting compliancy tests, they are also going to investigate
reorganizing code generation to improve locality.

The ootype group is also progressing well.  The RTyper has mostly been
refactored to be independent of the targeted type system and work is
continuing on implementing the new OOType type system alongside the
existing LLType target.  This group will be continuing, although with
somehwat different membership -- Michael joining and half of each of
Samuele and Arre leaving.

Michael and Andrew's work on the PPC backend has progressed to the
point where essentially any function that only manipulates integers
can be translated (with an exceedingly stupid register allocator).
Further work depends to a large extent on the llinterpreter work (see
below) so this work will wait until after the sprint.  Andrew is
moving to work on implementing a Numeric-a-like for PyPy, together
with Ludovic.

The LLInterpreter grouplette (Carl and 0.5 Armins and a little Holger)
did not produce much code since there are many decisions to be made
and the implications of these decisions are not understood.  A
discussion group of Carl, Armin, Samuele, Holger, Christian and Arre
will try to shine lights into these shadows, and report after lunch.

Valentino and Amaury are going to implement the socket module.  This
is a step towards allowing Valentino to run Twisted on PyPy and thus
make him very happy.

This sprint is working in quite a different way to previous sprints --
there is lots of discussion which isn't new, but the farming off of
discussion to groups of 5-6 people who present a report to the larger
group is a novelty and seems to be working well (15+ people is too
many for a focussed technical discussion).  Another difference is a
less strict emphasis on "pair" programming -- or, if you like, we are
still pair programming but we have redefined "pair" to mean a group of
two to six programmers :)

Cheers,
mwh & cfbolz

-- 
  Linux: Horse. Like a wild horse, fun to ride. Also prone to
  throwing you and stamping you into the ground because it doesn't
  like your socks.         -- Jim's pedigree of operating systems, asr