Subject: Re: ancillary data alignment and binary backward compatibility: please pick one
To: None <itojun@iijlab.net>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: tech-net
Date: 02/28/2000 10:02:41
On Mon, 28 Feb 2000 21:32:23 +0900
itojun@iijlab.net wrote:
> second multipart attachment:
> - use sysctl to get alignment constraint for CMSG_ALIGN().
> - no dependency from sys/socket.h to machine/param.h.
> - CMSG_xx are non-constant. you can't do the following:
> char foo[CMSG_SPACE(int)];
> - old compiled binary is okay on new kernel, even if they sees
> different defined in machine/param.h.
> - extra function calls on CMSG_ALIGN(). (we can decrease them by
> making static variable visible, I thought it would be safer to
> keep it inside function)
I think I vote for this one, too.
Note that in the case of an automatic variable, CMSG_SPACE(...) will
still work because of a GCC extension.
BTW, make sure to make the copyright date correct :-), and bump the libc
minor.
-- Jason R. Thorpe <thorpej@nas.nasa.gov>