[Numpy-discussion] Cython-based OpenMP-accelerated quartic polynomial solver

[Sturla Molden]

On 01/10/15 02:32, Juha Jeronen wrote:


> Sounds good. Out of curiosity, are there any standard fork-safe
> threadpools, or would this imply rolling our own?

You have to roll your own.

Basically use pthreads_atfork to register a callback that shuts down the 
threadpool before a fork and another callback that restarts it. Python's 
threading module does not expose the pthreads_atfork function, so you 
must call it from Cython.

I believe there is also a tiny atfork module in PyPI.

> So maybe it would be better, at least at first, to make a pure-Cython
> version with no attempt at multithreading?

I would start by making a pure Cython version that works correctly. The 
next step would be to ensure that it releases the GIL. After that you 
can worry about parallel processing, or just tell the user to use 
threads or joblib.


Sturla