From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12033C433B4 for ; Fri, 23 Apr 2021 14:44:35 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6370461462 for ; Fri, 23 Apr 2021 14:44:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6370461462 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47436 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lZx2n-0006JB-4d for qemu-devel@archiver.kernel.org; Fri, 23 Apr 2021 10:44:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53198) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZx2A-0005gG-VU for qemu-devel@nongnu.org; Fri, 23 Apr 2021 10:43:54 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:21124) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZx28-0003Ur-5i for qemu-devel@nongnu.org; Fri, 23 Apr 2021 10:43:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619189031; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=K6KE3/0KnUbn738NGUpgX9Vf7aV7k0xs3SsrgDjFx1o=; b=GQ1LatQCLIl4FYjwXfS23SclNEwhh/RW0ZQYU5uC3bLjtklLnWq5Ne+acKjMdoyiqJ6UBV DpwRkRvR7vUWU+ZtcTs0pYWbIEgFG7+uhcpe+v/CS2v95swfgel5g4um9JZDp2t/FXbN1d QmcdugtYRKSUeKTL/j/3NWmbO493wfU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-405-wuD_DdyNNTKaTNssQVB1qA-1; Fri, 23 Apr 2021 10:43:47 -0400 X-MC-Unique: wuD_DdyNNTKaTNssQVB1qA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 715F5343A6; Fri, 23 Apr 2021 14:43:46 +0000 (UTC) Received: from merkur.fritz.box (ovpn-114-199.ams2.redhat.com [10.36.114.199]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7D45219D9B; Fri, 23 Apr 2021 14:43:41 +0000 (UTC) Date: Fri, 23 Apr 2021 16:43:40 +0200 From: Kevin Wolf To: Vladimir Sementsov-Ogievskiy Subject: Re: [PATCH v3 08/36] util: add transactions.c Message-ID: References: <20210317143529.615584-1-vsementsov@virtuozzo.com> <20210317143529.615584-9-vsementsov@virtuozzo.com> MIME-Version: 1.0 In-Reply-To: <20210317143529.615584-9-vsementsov@virtuozzo.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: fam@euphon.net, qemu-block@nongnu.org, qemu-devel@nongnu.org, armbru@redhat.com, stefanha@redhat.com, mreitz@redhat.com, jsnow@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 17.03.2021 um 15:35 hat Vladimir Sementsov-Ogievskiy geschrieben: > Add simple transaction API to use in further update of block graph > operations. > > Supposed usage is: > > - "prepare" is main function of the action and it should make the main > effect of the action to be visible for the following actions, keeping > possibility of roll-back, saving necessary things in action state, > which is prepended to the action list (to do that, prepare func > should call tran_add()). So, driver struct doesn't include "prepare" > field, as it is supposed to be called directly. > > - commit/rollback is supposed to be called for the list of action > states, to commit/rollback all the actions in reverse order > > - When possible "commit" should not make visible effect for other > actions, which make possible transparent logical interaction between > actions. > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > include/qemu/transactions.h | 63 ++++++++++++++++++++++++ > util/transactions.c | 96 +++++++++++++++++++++++++++++++++++++ > MAINTAINERS | 6 +++ > util/meson.build | 1 + > 4 files changed, 166 insertions(+) > create mode 100644 include/qemu/transactions.h > create mode 100644 util/transactions.c > > diff --git a/include/qemu/transactions.h b/include/qemu/transactions.h > new file mode 100644 > index 0000000000..e7add9637f > --- /dev/null > +++ b/include/qemu/transactions.h > @@ -0,0 +1,63 @@ > +/* > + * Simple transactions API > + * > + * Copyright (c) 2021 Virtuozzo International GmbH. > + * > + * Author: > + * Vladimir Sementsov-Ogievskiy > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see . > + * > + * > + * = Generic transaction API = > + * > + * The intended usage is the following: you create "prepare" functions, which > + * represents the actions. They will usually have Transaction* argument, and > + * call tran_add() to register finalization callbacks. For finalization > + * callbacks, prepare corresponding TransactionActionDrv structures. > + * > + * Than, when you need to make a transaction, create an empty Transaction by Then > + * tran_create(), call your "prepare" functions on it, and finally call > + * tran_abort() or tran_commit() to finalize the transaction by corresponding > + * finalization actions in reverse order. > + */ > + > +#ifndef QEMU_TRANSACTIONS_H > +#define QEMU_TRANSACTIONS_H > + > +#include > + > +typedef struct TransactionActionDrv { > + void (*abort)(void *opaque); > + void (*commit)(void *opaque); > + void (*clean)(void *opaque); > +} TransactionActionDrv; > + > +typedef struct Transaction Transaction; > + > +Transaction *tran_new(void); > +void tran_add(Transaction *tran, TransactionActionDrv *drv, void *opaque); > +void tran_abort(Transaction *tran); > +void tran_commit(Transaction *tran); > + > +static inline void tran_finalize(Transaction *tran, int ret) > +{ > + if (ret < 0) { > + tran_abort(tran); > + } else { > + tran_commit(tran); > + } > +} > + > +#endif /* QEMU_TRANSACTIONS_H */ > diff --git a/util/transactions.c b/util/transactions.c > new file mode 100644 > index 0000000000..d0bc9a3e73 > --- /dev/null > +++ b/util/transactions.c > @@ -0,0 +1,96 @@ > +/* > + * Simple transactions API > + * > + * Copyright (c) 2021 Virtuozzo International GmbH. > + * > + * Author: > + * Sementsov-Ogievskiy Vladimir > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see . > + */ > + > +#include "qemu/osdep.h" > + > +#include "qemu/transactions.h" > +#include "qemu/queue.h" > + > +typedef struct TransactionAction { > + TransactionActionDrv *drv; > + void *opaque; > + QSLIST_ENTRY(TransactionAction) entry; "next" is a bit more conventional as a name, but by far not as much as I thought, so no objection. With the than/then typo fixed: Reviewed-by: Kevin Wolf