[pypy-dev] The Work Plan Re: STM proposal funding

[Armin Rigo]

Hi Andrew, hi all,

On Wed, Mar 28, 2012 at 18:23, Andrew Francis <andrewfr_ice at yahoo.com> wrote:
>>Indeed, and it was around 2007, so I expect the authors to have been
>>involved in completely different things for quite some time now...
>>But I could try to contact them anyway.
>
> Communications is good :-)

I'm also thinking about writing a short paper collecting things I said
and think on various blog posts.  A kind of "position paper".  What do
others think of this idea?

> My PyPy knowledge is still sketchy but I am changing that.  I do understand
> the Twisted reactor model
>  (thanks to my 2008 Pycon Talk) so I could follow discussions in that area.
> Is this discussed on IRC?

This is not discussed a lot right now.  But it is apparently
relatively easy to adapt the epoll-based Twisted reactor to use the
'transaction' module.  (Again, this module is present in the stm-gc
branch; look for lib_pypy/transaction.py for the interface, and
pypy/module/transaction/* for the Python implementation on top of STM
as exposed by RPython.)  This 'transaction' module is also meant to be
used directly, for example in this kind of Python code:

    for n in range(...):
        do_something(n)

If each call to do_something() has "reasonable chances" to be
independent from other calls, and if the order doesn't matter, then it
can be rewritten as:

    for n in range(...):
        transaction.add(do_something, n)
    transaction.run()

In addition, each transaction can add more transactions that will be
run after it.  So if you want to play with lib_pypy/stackless.py to
add calls to 'transaction', feel free :-)  Maybe it will show that a
slightly different API is required from the 'transaction' module; I
don't really know so far.


A bientôt,

Armin.