From patchwork Wed Sep 11 16:42:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 1161129 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 ozlabs.org (Postfix) with ESMTPS id 46T74B1sVPz9sNF for ; Thu, 12 Sep 2019 02:42:48 +1000 (AEST) Received: from localhost ([::1]:53638 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i85hc-0001Le-6S for incoming@patchwork.ozlabs.org; Wed, 11 Sep 2019 12:42:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41837) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i85h3-0001LS-1n for qemu-devel@nongnu.org; Wed, 11 Sep 2019 12:42:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i85h2-00005s-54 for qemu-devel@nongnu.org; Wed, 11 Sep 2019 12:42:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21733) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i85h1-00005J-W3 for qemu-devel@nongnu.org; Wed, 11 Sep 2019 12:42:08 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5656730024DA for ; Wed, 11 Sep 2019 16:42:07 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-117-243.ams2.redhat.com [10.36.117.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 55DE560C18; Wed, 11 Sep 2019 16:42:06 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, pbonzini@redhat.com, berrange@redhat.com, quintela@redhat.com Date: Wed, 11 Sep 2019 17:42:00 +0100 Message-Id: <20190911164202.31136-2-dgilbert@redhat.com> In-Reply-To: <20190911164202.31136-1-dgilbert@redhat.com> References: <20190911164202.31136-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Wed, 11 Sep 2019 16:42:07 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 1/3] rcu: Add automatically released rcu_read_lock variant 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: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" RCU_READ_LOCK_AUTO takes the rcu_read_lock and then uses glib's g_auto infrastrcture (and thus whatever the compilers hooks are) to release it on all exits of the block. Note this macro has a variable declaration in, and hence is not in a while loop. Signed-off-by: Dr. David Alan Gilbert --- include/qemu/rcu.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/qemu/rcu.h b/include/qemu/rcu.h index 22876d1428..6a25b27d28 100644 --- a/include/qemu/rcu.h +++ b/include/qemu/rcu.h @@ -154,6 +154,18 @@ extern void call_rcu1(struct rcu_head *head, RCUCBFunc *func); }), \ (RCUCBFunc *)g_free); +typedef char rcu_read_auto_t; +static inline void rcu_read_auto_unlock(rcu_read_auto_t *r) +{ + rcu_read_unlock(); +} + +G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(rcu_read_auto_t, rcu_read_auto_unlock) + +#define RCU_READ_LOCK_AUTO g_auto(rcu_read_auto_t) \ + _rcu_read_auto = 'x'; \ + rcu_read_lock(); + #ifdef __cplusplus } #endif