Date: Mon, 19 Nov 2012 19:13:33 +0100 From: Andre Oppermann <andre@freebsd.org> To: mdf@FreeBSD.org Cc: Gleb Smirnoff <glebius@freebsd.org>, src-committers@freebsd.org, svn-src-user@freebsd.org Subject: Re: svn commit: r243215 - user/andre/tcp_workqueue/sys/sys Message-ID: <50AA76CD.3070904@freebsd.org> In-Reply-To: <CAMBSHm_eu-z6fuxTL2bdavQeBjOcE1zvS5h4itGa%2BP%2BiQhqrrA@mail.gmail.com> References: <201211181217.qAICH7aH021497@svn.freebsd.org> <20121119114510.GQ38060@FreeBSD.org> <50AA3529.2030300@freebsd.org> <CAMBSHm_eu-z6fuxTL2bdavQeBjOcE1zvS5h4itGa%2BP%2BiQhqrrA@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 19.11.2012 18:01, mdf@FreeBSD.org wrote: > On Mon, Nov 19, 2012 at 5:33 AM, Andre Oppermann <andre@freebsd.org> wrote: >> On 19.11.2012 12:45, Gleb Smirnoff wrote: >>> >>> On Sun, Nov 18, 2012 at 12:17:07PM +0000, Andre Oppermann wrote: >>> A> Author: andre >>> A> Date: Sun Nov 18 12:17:07 2012 >>> A> New Revision: 243215 >>> A> URL: http://svnweb.freebsd.org/changeset/base/243215 >>> A> >>> A> Log: >>> A> Add mtodo(m, o, t) macro taking an additional offset into >>> A> the mbuf data section before the casting to type 't'. >>> >>> IMHO, argument order of (m, t, o) is more intuitive, since >>> matches order of mtod(). >> >> >> Yes, but that looks rather horrible and counter-intuitive: >> >> th = mtodo(m, struct tcphdr *, 20); >> >> vs. >> >> th = mtodo(m, 20, struct tcphdr *); >> >> Reads m->m_data at offset 20 is struct tcphdr. >> >> Naming it mtood() wasn't convincing either. ;-) > > Why a cast at all? Perpetuating the mistake of mtod()'s casting isn't > necessary. mtod() can't be fixed for source reasons, but the new one > doesn't need to cast. Since C automatically casts from void * to any > other pointer, the code gets shorter (usually) too: > > th = mtodo(m, 20); m->m_data is caddr_t which is "char *" > Not that I care much, it's just if we're having a bikeshed I have my > favorite colors. :-) -- Andre
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?50AA76CD.3070904>