From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 78CF7A04F6; Wed, 11 Dec 2019 14:11:35 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id AAC272C6A; Wed, 11 Dec 2019 14:11:34 +0100 (CET) Received: from smtp.tuxdriver.com (charlotte.tuxdriver.com [70.61.120.58]) by dpdk.org (Postfix) with ESMTP id 227D423D for ; Wed, 11 Dec 2019 14:11:33 +0100 (CET) Received: from 2606-a000-111b-43ee-0000-0000-0000-115f.inf6.spectrum.com ([2606:a000:111b:43ee::115f] helo=localhost) by smtp.tuxdriver.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.63) (envelope-from ) id 1if1lg-0006Nu-BP; Wed, 11 Dec 2019 08:11:09 -0500 Date: Wed, 11 Dec 2019 08:11:03 -0500 From: Neil Horman To: Ferruh Yigit Cc: "Kinsella, Ray" , Thomas Monjalon , David Marchand , Luca Boccassi , Christian Ehrhardt , Timothy Redaelli , Kevin Traynor , dpdk-dev , Bruce Richardson , "Laatz, Kevin" , Andrew Rybchenko , Neil Horman Message-ID: <20191211131103.GA19627@hmswarspite.think-freely.org> References: <5df1a33b-b338-bde1-6834-e8b5fbe65a04@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5df1a33b-b338-bde1-6834-e8b5fbe65a04@intel.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Spam-Score: -2.9 (--) X-Spam-Status: No Subject: Re: [dpdk-dev] How to manage new APIs added after major ABI release? X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Dec 10, 2019 at 11:56:28AM +0000, Ferruh Yigit wrote: > Hi, > > With new process, the major ABI releases will be compatible until it is > deprecated (until next LTS for now), > like current ABI version is 20 in DPDK_19.11 and DPDK versions until DPDK_20.11 > will be ABI compatible with this version. > > But if we introduce a new API after major ABI, say in 20.02 release, are we > allowed to break the ABI for that API before DPDK_20.11? > > If we allow it break, following problem will be observed: > Assume an application using .so.20.1 library, and using the new API introduced > in 20.02, lets say foo(), > but when application switches to .so.20.2 (released via DPDK_20.05), application > will fail because of ABI breakage in foo(). > > I think it is fair that application expects forward compatibility in minor > versions of a shared library. > Like if application linked against .so.20.2, fair to expect .so.20.3, .so.20.4 > etc will work fine. I think currently only .so.20.0 is fully forward compatible. > > If we all agree on this, we may need to tweak the process a little, but before > diving into implementation details, I would like to be sure we are in same page. > Yes, I agree with the assertion. Once an ABI is fixed, it must be compatible with all future minor releases subsequent to the fixing of that ABI, until the next major update. That is to say, once you release ABI_20, all minor updates 20.01, 20.02, etc must be compatible with ABI_20 until such time as ABI_21 is released. Neil > > Thanks, > ferruh >