[Numpy-discussion] Numpy arrays shareable among related processes (PR #7533)

[Antoine Pitrou]

On Thu, 12 May 2016 23:14:36 +0000 (UTC)
Sturla Molden <sturla.molden at gmail.com> wrote:
> Antoine Pitrou <solipsis at pitrou.net> wrote:
> 
> > Can you define "expensive"?
> 
> Slow enough to cause complaints on the Cython mailing list.

What kind of complaints? Please be specific.

> > Buffer acquisition itself only calls a single C callback and uses a
> > stack-allocated C structure. It shouldn't be "expensive".
> 
> I don't know the reason, only that buffer acquisition from NumPy arrays
> with typed memoryviews

Again, what have memoryviews to do with it?  "Acquiring a buffer" is
just asking the buffer provider (the Numpy array) to fill a Py_buffer
structure's contents.  That has nothing to do with memoryviews.

When writing C code to interact with buffer-providing objects, you
usually don't bother with memoryviews at all.  You just use a Py_buffer
structure.

Regards

Antoine.