[zeromq-dev] pyzmq ctypes

[MinRK]

Hello,


This is very cool!

Once you have send/recv, you should be mostly there.  In PyPy, there's
not much of a reason for most of the rest of the code to not be pure
Python.

Most of the challenging code in pyzmq has to do with non-copying sends
and/or buffer-interface providing objects.

For non-copying sends, refcounting is a lot of the tricky bits, and I
don't know how that would change in PyPy which is very different in
that regard.  The main point is that if you do:

s.send(buffer) # or memoryview

both Python and libzmq hold a reference to the buffer, and you have to
ensure that neither will free the memory when it's done if the other
still holds its reference.

Much of the buffer-interface difficulty comes from our decision to
support Python 2.5 and 3.x, which makes dealing with the ever-changing
C-API a pain.  With PyPy, you may not have to deal with that at all,
and I don't know anything about how PyPy handles memoryviews/buffers
with respect to ctypes.

The only other non-trivial Cython code is the MonitoredQueue device,
but if you drop support for the in-process Thread version, there's no
reason not to rewrite it in Python if your target is PyPy, which
should be quite straightforward (or rewrite it as a pure-C extension
function and call it with ctypes).

-MinRK

On Wed, May 25, 2011 at 07:56, Pieter Hintjens <ph at imatix.com> wrote:
> On Wed, May 25, 2011 at 4:14 PM, Daniel Holth <dholth at gmail.com> wrote:
>> By popular demand (one person asked) the "Release Early" edition of
>> pyzmq-ctypes is at https://bitbucket.org/dholth/pyzmqctypes
>
> :-) A vote of 1 is still infinitely better than silence.
>
>> Unlike the Cython version, this binding works in pypy. A file called _zmq.py
>> contains most of the goodies. It implements most of the low-level ZeroMQ API
>> and a tiny bit of the pyzmq wrapper. A serious contributor might want to
>> incorporate the pyzmq unit tests and hack until they run, or go in a
>> different direction by wraping libzapi.
>
> It's now called czmq, but it'd be interesting to have feedback on how
> easy/hard it is to wrap. Although the goal isn't to get czmq used by
> language bindings, it's a model for other APIs that would be aimed at
> general binding reuse.
>
> -Pieter
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