From patchwork Wed Oct 28 15:01:02 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Denis V. Lunev" X-Patchwork-Id: 537400 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3D99D1402B9 for ; Thu, 29 Oct 2015 02:02:13 +1100 (AEDT) Received: from localhost ([::1]:38610 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZrSEt-0005Mm-AD for incoming@patchwork.ozlabs.org; Wed, 28 Oct 2015 11:02:11 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37378) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZrSED-0004CO-RJ for qemu-devel@nongnu.org; Wed, 28 Oct 2015 11:01:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZrSE5-0003Bo-SI for qemu-devel@nongnu.org; Wed, 28 Oct 2015 11:01:29 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:40354 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZrSDx-00038I-6K; Wed, 28 Oct 2015 11:01:13 -0400 Received: from hades.sw.ru ([10.30.8.132]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id t9SF15Vk000526; Wed, 28 Oct 2015 18:01:08 +0300 (MSK) From: "Denis V. Lunev" To: Date: Wed, 28 Oct 2015 18:01:02 +0300 Message-Id: <1446044465-19312-2-git-send-email-den@openvz.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1446044465-19312-1-git-send-email-den@openvz.org> References: <1446044465-19312-1-git-send-email-den@openvz.org> X-detected-operating-system: by eggs.gnu.org: OpenBSD 3.x X-Received-From: 195.214.232.25 Cc: "Denis V. Lunev" , Paolo Bonzini , qemu-devel@nongnu.org, Stefan Hajnoczi , qemu-stable@nongnu.org Subject: [Qemu-devel] [PATCH 1/4] fifolock: create rfifolock_is_locked helper X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 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-bounces+incoming=patchwork.ozlabs.org@nongnu.org This helper is necessary to ensure locking constraints. Signed-off-by: Denis V. Lunev CC: Stefan Hajnoczi CC: Paolo Bonzini --- include/qemu/rfifolock.h | 1 + util/rfifolock.c | 9 +++++++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/include/qemu/rfifolock.h b/include/qemu/rfifolock.h index b23ab53..2c00c4b 100644 --- a/include/qemu/rfifolock.h +++ b/include/qemu/rfifolock.h @@ -50,5 +50,6 @@ void rfifolock_init(RFifoLock *r, void (*cb)(void *), void *opaque); void rfifolock_destroy(RFifoLock *r); void rfifolock_lock(RFifoLock *r); void rfifolock_unlock(RFifoLock *r); +int rfifolock_is_locked(RFifoLock *r); #endif /* QEMU_RFIFOLOCK_H */ diff --git a/util/rfifolock.c b/util/rfifolock.c index afbf748..8ac58cb 100644 --- a/util/rfifolock.c +++ b/util/rfifolock.c @@ -48,7 +48,7 @@ void rfifolock_lock(RFifoLock *r) /* Take a ticket */ unsigned int ticket = r->tail++; - if (r->nesting > 0 && qemu_thread_is_self(&r->owner_thread)) { + if (r->nesting > 0 && rfifolock_is_locked(r)) { r->tail--; /* put ticket back, we're nesting */ } else { while (ticket != r->head) { @@ -69,10 +69,15 @@ void rfifolock_unlock(RFifoLock *r) { qemu_mutex_lock(&r->lock); assert(r->nesting > 0); - assert(qemu_thread_is_self(&r->owner_thread)); + assert(rfifolock_is_locked(r)); if (--r->nesting == 0) { r->head++; qemu_cond_broadcast(&r->cond); } qemu_mutex_unlock(&r->lock); } + +int rfifolock_is_locked(RFifoLock *r) +{ + return qemu_thread_is_self(&r->owner_thread); +}