Date: Mon, 6 Dec 1999 03:29:10 +1100 (EST) From: Bruce Evans <bde@zeta.org.au> To: Marcel Moolenaar <marcel@scc.nl> Cc: Martin Cracauer <cracauer@cons.org>, freebsd-arch@freebsd.org Subject: Re: cvs commit: src/sys/i386/include signal.h Message-ID: <Pine.BSF.4.10.9912060309170.2007-100000@alphplex.bde.org> In-Reply-To: <384A3D54.3DFE76D6@scc.nl>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, 5 Dec 1999, Marcel Moolenaar wrote: > Martin Cracauer wrote: > > Decisions in order of importance: > > - Do you accept bumping mcontext_t to 512 bytes? > > No, I'll accept ucontext_t to be bumped to a nice round number (say 512 > bytes) and have the extra space used by mcontext_t :-) I don't want a round number (except maybe to a cache line or -mpreferred-stack boundary). Leaving space at the end of ucontext_t alone doesn't work because it is discontiguous with uc_mcontext. Leaving space in the middle of ucontext_t would be little better. OTOH, any expansion of mcontext_t while it is in the middle of ucontext_t would break binary compatibility. I think mcontext_t should go at the end of ucontext_t and most extensions should be in mcontext_t (just leave a few spares in ucontext_t and try not to use them). We would have to break binary compatibility again to move mcontext_t :-(. > > > - Do you like the bitmap scheme? > > Yes. It's quite common. Yes. > in mcontext_t: > ! int mc_fpemul[16]; /* Additional FPU emulator > status */ > ! int __morespare__[63]; /* For later additions, total = > 512 */ > > There's no need to rub it in :-) I prefer `__spare__' to make it clear > that it's not a regular field. I think Bruce would like you to use > `sc_spare'... I like struct member names to have prefixes. Prefixes are almost required in API headers to limit namespace pollution. When you have a prefix, using underscores is just and obfuscation. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.10.9912060309170.2007-100000>