From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <nhorman@tuxdriver.com> Received: from smtp.tuxdriver.com (charlotte.tuxdriver.com [70.61.120.58]) by dpdk.org (Postfix) with ESMTP id 6E63F5F17 for <dev@dpdk.org>; Fri, 9 Mar 2018 16:17:11 +0100 (CET) Received: from cpe-2606-a000-111b-40b7-640c-26a-4e16-9225.dyn6.twc.com ([2606:a000:111b:40b7:640c:26a:4e16:9225] helo=localhost) by smtp.tuxdriver.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.63) (envelope-from <nhorman@tuxdriver.com>) id 1euJlJ-0008VU-UC; Fri, 09 Mar 2018 10:17:01 -0500 Date: Fri, 9 Mar 2018 10:16:16 -0500 From: Neil Horman <nhorman@tuxdriver.com> To: Ferruh Yigit <ferruh.yigit@intel.com> Cc: John McNamara <john.mcnamara@intel.com>, Marko Kovacevic <marko.kovacevic@intel.com>, Thomas Monjalon <thomas@monjalon.net>, dev@dpdk.org Message-ID: <20180309151616.GC19004@hmswarspite.think-freely.org> References: <20180117215802.90809-2-ferruh.yigit@intel.com> <20180309112531.292163-1-ferruh.yigit@intel.com> <20180309123651.GB19004@hmswarspite.think-freely.org> <b12988d0-cb4a-2dcb-c20a-37cfbdf73eda@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <b12988d0-cb4a-2dcb-c20a-37cfbdf73eda@intel.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-Spam-Score: -2.9 (--) X-Spam-Status: No Subject: Re: [dpdk-dev] [PATCH v4] ethdev: return named opaque type instead of void pointer X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Fri, 09 Mar 2018 15:17:11 -0000 On Fri, Mar 09, 2018 at 01:00:35PM +0000, Ferruh Yigit wrote: > On 3/9/2018 12:36 PM, Neil Horman wrote: > > On Fri, Mar 09, 2018 at 11:25:31AM +0000, Ferruh Yigit wrote: > >> "struct rte_eth_rxtx_callback" is defined as internal data structure and > >> used as named opaque type. > >> > >> So the functions that are adding callbacks can return objects in this > >> type instead of void pointer. > >> > >> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com> > >> Acked-by: Stephen Hemminger <stephen@networkplumber.org> > >> --- > >> v2: > >> * keep using struct * in parameters, instead add callback functions > >> return struct rte_eth_rxtx_callback pointer. > >> > >> v4: > >> * Remove deprecation notice. LIBABIVER already increased in this release > >> --- > >> doc/guides/rel_notes/deprecation.rst | 7 ------- > >> lib/librte_ether/rte_ethdev.c | 6 +++--- > >> lib/librte_ether/rte_ethdev.h | 13 ++++++++----- > >> 3 files changed, 11 insertions(+), 15 deletions(-) > >> > > This doesn't quite make sense to me. If rte_eth_rxtx_callback is defined as an > > internal data structure, then it shouldn't be used as part of the prototype for > > an exported function, as the structure will then no longer be a internal data > > structure, but rather part of the public ABI. > > "struct rte_eth_rxtx_callback" is internal data structure. And application > should not access elements of this structure. > > "struct rte_eth_rxtx_callback;" is defined in the public header, so applications > can use it as opaque type. > > It is possible that both "add" and "remove" APIs use "void *" and API itself can > cast it. But the inconsistency was "add" related APIs return "void *" and > "remove" related APIs require a parameter in "struct rte_eth_rxtx_callback *" type. > > While unifying the usage, "struct rte_eth_rxtx_callback *" preferred against > "void *", because named opaque type documents intention/usage better. > > Thanks, > ferruh > I get what you're saying about rte_eth_rxtx_callback being an internals structure (or its intent is to be an internal structure), but it doesn't seem to hold up to the header file layout. rte_eth_rxtx_callback is defined in rte_ethdev_core.h which according to the makefile, is listed as a symlinked file, and therefore available for external applications to include. This negates the intended opaque nature of the struct. I think before you do this, you want to rectify that. Neil > > > > Neil > > > >