From patchwork Fri Jan 25 11:46:58 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 215671 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 6DBD82C0093 for ; Sat, 26 Jan 2013 00:25:23 +1100 (EST) Received: from localhost ([::1]:52594 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TyjHV-0006Ht-HE for incoming@patchwork.ozlabs.org; Fri, 25 Jan 2013 08:25:21 -0500 Received: from eggs.gnu.org ([208.118.235.92]:51998) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TyjHH-0006Fg-G8 for qemu-devel@nongnu.org; Fri, 25 Jan 2013 08:25:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TyjHC-0005uX-1k for qemu-devel@nongnu.org; Fri, 25 Jan 2013 08:25:07 -0500 Received: from mail-qc0-f181.google.com ([209.85.216.181]:35075) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tyhkm-0005Cg-5Q for qemu-devel@nongnu.org; Fri, 25 Jan 2013 06:47:28 -0500 Received: by mail-qc0-f181.google.com with SMTP id x40so122005qcp.26 for ; Fri, 25 Jan 2013 03:47:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:sender:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references; bh=cO2SwASf8QLE12T6IUVhD3uAJ2vT5BAfqJdZR1p6+X0=; b=GQwtUTP8/WHR3tlXT/elc+6x6jD73x/2vyDElVtNOi8leklrilvGeKXPhhey3qh29B vDXz7jmJJtAae1GreOK3USqMHTOQyN2bKAKREuvKUyMVztcoRQyzLmE89Tm2+/01BBi8 6ybkvg8cLIdpoKGXBDCDlvDRGigjbISGV1SrgvQGvi4dJ4Ky4vMKaQkrt6tdh7NLEqmr AT6N18c6cDpLGoyzScVlU8P0eHpSZ6AozM+ePsEnKl9z28RLMugbF9PHbr9Il0Yv3Jrg JNMgAnIyrYO1XBMrtwDlXuSfA7PwSjzKXJTz0CqA09RhSNDpsd3qo312b/HhygLXrl91 gLuQ== X-Received: by 10.224.60.12 with SMTP id n12mr5548670qah.23.1359114447586; Fri, 25 Jan 2013 03:47:27 -0800 (PST) Received: from yakj.usersys.redhat.com (93-34-179-137.ip50.fastwebnet.it. [93.34.179.137]) by mx.google.com with ESMTPS id eg9sm419389qab.7.2013.01.25.03.47.25 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 25 Jan 2013 03:47:26 -0800 (PST) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Fri, 25 Jan 2013 12:46:58 +0100 Message-Id: <1359114420-16149-11-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.1 In-Reply-To: <1359114420-16149-1-git-send-email-pbonzini@redhat.com> References: <1359114420-16149-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 209.85.216.181 Cc: afaerber@suse.de Subject: [Qemu-devel] [PATCH v3 10/12] 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 4e2a92b..4f9a6eb 100644 --- a/hw/qdev-monitor.c +++ b/hw/qdev-monitor.c @@ -591,6 +591,7 @@ 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)) { @@ -602,10 +603,12 @@ 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 381d56c..b0b2265 100644 --- a/hw/qdev.c +++ b/hw/qdev.c @@ -143,7 +143,7 @@ DeviceState *qdev_try_create(BusState *bus, const char *type) } qdev_set_parent_bus(dev, bus); - + object_unref(OBJECT(dev)); return dev; } @@ -268,7 +268,6 @@ 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) @@ -428,6 +427,7 @@ static void qbus_realize(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. */ @@ -474,7 +474,6 @@ 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 4ee1302..b096144 100644 --- a/vl.c +++ b/vl.c @@ -2233,6 +2233,7 @@ static int device_init_func(QemuOpts *opts, void *opaque) dev = qdev_device_add(opts); if (!dev) return -1; + object_unref(OBJECT(dev)); return 0; }