Re: [Pytables-users] threading/GIL

[Francesc A. <fa...@ca...>]

Hi Andrew,

A Dimecres 15 Desembre 2004 03:49, Andrew Straw va escriure:
> I enclose a small patch (against CVS HEAD) which demonstrates how to=20
> release the GIL during potentially long operations.  I think all=20
> potentially long operations (basically most of the C H5* functions)=20
> should be bracketed by these statements.

Done. I've applied your patch, and besides, looked at the places where
potentially long operations would happen and backeted them by
BEGIN_ALLOW_THREADS/END_ALLOW_THREADS. After some work (some variables
passed to the C functions were Python objects), all the tests units pass
fine.

The patched version is already in CVS HEAD.

> For example purposes, I've only tracked down this single operation.  If=20
> you'd like any more explanation/justification/etc., please let me know=20
> and I'll do my best.

I think it would be interesting if you can provide some (small) example on
how you can speed-up your I/O by using threading. I can manage to put that
example (or similar) in the chapter of "Optimization Tips" in PyTables
manual. By the way, do you think that doing multithreading on a single-CPU
machine would made some processes more efficient? I mean, if you have a
thread for reading and other for processing the read data, perhaps you can
get some speed-up (while I doubt it, that would be just great).

Thanks for your contribution!

=2D-=20
=46rancesc Altet
Who's your data daddy? =A0PyTables