Re: [Libusb-devel] Patch: Changed calls to malloc+memset into calloc

[Tim R. <ti...@pr...>]

Michael Plante wrote:
> Tim Roberts wrote:
>>> Windows does not use the zero-page technique.
> I'm not sure this is true.  It might be more accurate to say that the C
> Runtime Library doesn't make any assumptions about the page.

You are exactly right -- my statement was too broad.  The Windows kernel
certainly uses the zero-page copy-on-write concept, but the CRT does not
assume it.

The whole zero-page thing can only help calloc if the allocation is
large enough to require whole pages.  Most libusb allocations are for
structures, which are small.  Such allocations will be sharing a page
with other heap residents, so it has to do a memset.

-- 
Tim Roberts, ti...@pr...
Providenza & Boekelheide, Inc.