From patchwork Wed Dec 5 20:44:40 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 203942 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id EE4662C00F3 for ; Thu, 6 Dec 2012 07:45:35 +1100 (EST) Received: from localhost ([::1]:48281 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TgLqX-0000iB-VH for incoming@patchwork.ozlabs.org; Wed, 05 Dec 2012 15:45:33 -0500 Received: from eggs.gnu.org ([208.118.235.92]:52572) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TgLq5-0000Lo-L6 for qemu-devel@nongnu.org; Wed, 05 Dec 2012 15:45:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TgLq4-0001LR-Cl for qemu-devel@nongnu.org; Wed, 05 Dec 2012 15:45:05 -0500 Received: from mail-ea0-f173.google.com ([209.85.215.173]:49597) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TgLq4-0001D6-6D for qemu-devel@nongnu.org; Wed, 05 Dec 2012 15:45:04 -0500 Received: by mail-ea0-f173.google.com with SMTP id i13so2322945eaa.4 for ; Wed, 05 Dec 2012 12:45:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=UbU+j0T9gE6xWzL1pnZCIRTrPo0bwUE5uDgEXlyNzok=; b=gUoNcFMyYcAjn/rZVArGYeCfimU6fzgydfCPj7bvwntKORD0WCtLsIebxCZWJ6XUJr iBAU8USgI8337MudO05wXJJbzBZQMnvfpPkkQeXU4TB9nqfXizF16Roz6V1Ss0y0T9YH cOn9haT9qTYQYPviPBL4qUlU4R8xvrJDX/LBrHw3qdh14SLqaM0klyGVTyPhvaIlAw8c W/XdkiCOHNmu4PwTDaWrNsUCEKSZbJYZDUONFyNsYgj8F2INrIDKE8YZgyRaK4fW0qih fm9LqS8ZhgvW5x4LphzSiyCAArJa+tnaCmMevOXGOsGODWN1drfKA7xPNa05XSXLLc2X RcCw== Received: by 10.14.3.8 with SMTP id 8mr14366840eeg.40.1354740303746; Wed, 05 Dec 2012 12:45:03 -0800 (PST) Received: from yakj.usersys.redhat.com (93-34-219-150.ip51.fastwebnet.it. [93.34.219.150]) by mx.google.com with ESMTPS id a44sm11396163eeo.7.2012.12.05.12.45.02 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 05 Dec 2012 12:45:03 -0800 (PST) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 5 Dec 2012 21:44:40 +0100 Message-Id: <1354740282-20679-10-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.0.1 In-Reply-To: <1354740282-20679-1-git-send-email-pbonzini@redhat.com> References: <1354740282-20679-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 209.85.215.173 Cc: aliguori@us.ibm.com, afaerber@suse.de Subject: [Qemu-devel] [PATCH 09/11] qdev: drop extra references at creation time 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 qdev_free and qbus_free have to do unparent+unref, because nobody else drops the initial reference (the one included by object_initialize) before them. For device_init_func and do_device_add, this is trivially correct, since the DeviceState goes out of scope. For qdev_create, qdev_try_create and qbus_init, it is a bit more tricky. What we are doing here is just assuming that the caller knows what it's doing, and won't call qdev_free/qbus_free while the device is still there. This is a pretty reasonable assumption and (behind the scenes) is also what GObject/GTK does. GTK actually has a "floating reference" that goes away as soon as the caller does gtk_container_add or something like that, but in the end qbus_init and qdev_try_create are already adding the new object to its qdev parent! So in the end the two solutions are the same. Signed-off-by: Paolo Bonzini --- hw/qdev-monitor.c | 5 ++++- hw/qdev.c | 5 ++--- vl.c | 1 + 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c index a1b4d6a..ed62fd3 100644 --- a/hw/qdev-monitor.c +++ b/hw/qdev-monitor.c @@ -578,6 +578,7 @@ int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data) { Error *local_err = NULL; QemuOpts *opts; + DeviceState *dev; opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, &local_err); if (error_is_set(&local_err)) { @@ -589,10 +590,12 @@ int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data) qemu_opts_del(opts); return 0; } - if (!qdev_device_add(opts)) { + dev = qdev_device_add(opts); + if (!dev) { qemu_opts_del(opts); return -1; } + object_unref(OBJECT(dev)); return 0; } diff --git a/hw/qdev.c b/hw/qdev.c index dcd39b3..9f4fd92 100644 --- a/hw/qdev.c +++ b/hw/qdev.c @@ -142,7 +142,7 @@ DeviceState *qdev_try_create(BusState *bus, const char *type) } qdev_set_parent_bus(dev, bus); - + object_unref(OBJECT(dev)); return dev; } @@ -269,7 +269,6 @@ void qdev_init_nofail(DeviceState *dev) void qdev_free(DeviceState *dev) { object_unparent(OBJECT(dev)); - object_unref(OBJECT(dev)); } void qdev_machine_creation_done(void) @@ -441,6 +440,7 @@ void qbus_init(BusState *bus, DeviceState *parent, const char *name) QLIST_INSERT_HEAD(&bus->parent->child_bus, bus, sibling); bus->parent->num_child_bus++; object_property_add_child(OBJECT(bus->parent), bus->name, OBJECT(bus), NULL); + object_unref(OBJECT(bus)); } else if (bus != sysbus_get_default()) { /* TODO: once all bus devices are qdevified, only reset handler for main_system_bus should be registered here. */ @@ -487,7 +487,6 @@ BusState *qbus_create(const char *typename, DeviceState *parent, const char *nam void qbus_free(BusState *bus) { object_unparent(OBJECT(bus)); - object_unref(OBJECT(bus)); } static char *bus_get_fw_dev_path(BusState *bus, DeviceState *dev) diff --git a/vl.c b/vl.c index a3ab384..71c339c 100644 --- a/vl.c +++ b/vl.c @@ -2052,6 +2052,7 @@ static int device_init_func(QemuOpts *opts, void *opaque) dev = qdev_device_add(opts); if (!dev) return -1; + object_unref(OBJECT(dev)); return 0; }