Date: Fri, 07 Dec 2012 15:08:34 +0100 From: Dimitry Andric <dim@FreeBSD.org> To: Mark Atkinson <atkin901@gmail.com> Cc: kde-freebsd@kde.org, freebsd-current@FreeBSD.org Subject: Re: problems with threads/destructors in -current with llvm/clang Message-ID: <50C1F862.2010501@FreeBSD.org> In-Reply-To: <50C1E81A.1040107@FreeBSD.org> References: <k9qjml$ri7$1@ger.gmane.org> <50C1E81A.1040107@FreeBSD.org>
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On 2012-12-07 13:59, Dimitry Andric wrote:
> On 2012-12-06 18:12, Mark Atkinson wrote:
>> Short backstory, I had recently upgraded my workstation to the latest
>> current which included clang as default cc now.
> ...
>> qdbus under kde segfaults in malloc with a huge recursion stack:
...
> This is a bug in qdbus; it uses a global static QDBusConnection object,
> and the order in which global destructors are called is undefined:
...
> The global static QDBusConnection object should be replaced by a
> singleton, as suggested here:
Here is an alternative solution, where the QDBusConnection object is
just a local variable in main(), and passed around as a const reference.
To make the destructors work properly, I also replaced the exit() calls
in main() with return statements.
With this patch (placed in /usr/ports/devel/dbus-qt4/files), qdbus
starts up and exits normally for me. I did not do any other rigorous
testing, though. :)
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name="patch-tools__qdbus__qdbus__qdbus.cpp"
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filename="patch-tools__qdbus__qdbus__qdbus.cpp"
--- tools/qdbus/qdbus/qdbus.cpp.orig 2012-04-26 21:45:51.000000000 +0200
+++ tools/qdbus/qdbus/qdbus.cpp 2012-12-07 14:46:43.000000000 +0100
@@ -54,7 +54,6 @@ QT_BEGIN_NAMESPACE
Q_DBUS_EXPORT extern bool qt_dbus_metaobject_skip_annotations;
QT_END_NAMESPACE
-static QDBusConnection connection(QLatin1String(""));
static bool printArgumentsLiterally = false;
static void showUsage()
@@ -111,7 +110,7 @@ static void printArg(const QVariant &v)
}
}
-static void listObjects(const QString &service, const QString &path)
+static void listObjects(const QString &service, const QString &path, const QDBusConnection &connection)
{
// make a low-level call, to avoid introspecting the Introspectable interface
QDBusMessage call = QDBusMessage::createMethodCall(service, path.isEmpty() ? QLatin1String("/") : path,
@@ -144,13 +143,13 @@ static void listObjects(const QString &s
if (child.tagName() == QLatin1String("node")) {
QString sub = path + QLatin1Char('/') + child.attribute(QLatin1String("name"));
printf("%s\n", qPrintable(sub));
- listObjects(service, sub);
+ listObjects(service, sub, connection);
}
child = child.nextSiblingElement();
}
}
-static void listInterface(const QString &service, const QString &path, const QString &interface)
+static void listInterface(const QString &service, const QString &path, const QString &interface, const QDBusConnection &connection)
{
QDBusInterface iface(service, path, interface, connection);
if (!iface.isValid()) {
@@ -204,7 +203,7 @@ static void listInterface(const QString
}
}
-static void listAllInterfaces(const QString &service, const QString &path)
+static void listAllInterfaces(const QString &service, const QString &path, const QDBusConnection &connection)
{
// make a low-level call, to avoid introspecting the Introspectable interface
QDBusMessage call = QDBusMessage::createMethodCall(service, path.isEmpty() ? QLatin1String("/") : path,
@@ -229,7 +228,7 @@ static void listAllInterfaces(const QStr
if (child.tagName() == QLatin1String("interface")) {
QString ifaceName = child.attribute(QLatin1String("name"));
if (QDBusUtil::isValidInterfaceName(ifaceName))
- listInterface(service, path, ifaceName);
+ listInterface(service, path, ifaceName, connection);
else {
qWarning("Invalid D-BUS interface name '%s' found while parsing introspection",
qPrintable(ifaceName));
@@ -253,7 +252,7 @@ static QStringList readList(QStringList
return retval;
}
-static int placeCall(const QString &service, const QString &path, const QString &interface,
+static int placeCall(const QString &service, const QString &path, const QString &interface, const QDBusConnection &connection,
const QString &member, const QStringList& arguments, bool try_prop=true)
{
QDBusInterface iface(service, path, interface, connection);
@@ -291,7 +290,7 @@ static int placeCall(const QString &serv
proparg += interface;
proparg += member;
proparg += args.first();
- if (!placeCall(service, path, "org.freedesktop.DBus.Properties", "Set", proparg, false))
+ if (!placeCall(service, path, "org.freedesktop.DBus.Properties", connection, "Set", proparg, false))
return 0;
}
fprintf(stderr, "Cannot find '%s.%s' in object %s at %s\n",
@@ -387,7 +386,7 @@ static int placeCall(const QString &serv
QStringList proparg;
proparg += interface;
proparg += member;
- if (!placeCall(service, path, "org.freedesktop.DBus.Properties", "Get", proparg, false))
+ if (!placeCall(service, path, "org.freedesktop.DBus.Properties", connection, "Get", proparg, false))
return 0;
}
if (err.type() == QDBusError::ServiceUnknown)
@@ -448,6 +447,7 @@ int main(int argc, char **argv)
QCoreApplication app(argc, argv);
QStringList args = app.arguments();
args.takeFirst();
+ QDBusConnection connection(QLatin1String(""));
bool connectionOpened = false;
while (!args.isEmpty() && args.at(0).startsWith(QLatin1Char('-'))) {
@@ -481,7 +481,7 @@ int main(int argc, char **argv)
QDBusConnectionInterface *bus = connection.interface();
if (args.isEmpty()) {
printAllServices(bus);
- exit(0);
+ return 0;
}
QString service = args.takeFirst();
@@ -491,22 +491,22 @@ int main(int argc, char **argv)
return 0;
}
fprintf(stderr, "Service '%s' is not a valid name.\n", qPrintable(service));
- exit(1);
+ return 1;
}
if (args.isEmpty()) {
- listObjects(service, QString());
- exit(0);
+ listObjects(service, QString(), connection);
+ return 0;
}
QString path = args.takeFirst();
if (!QDBusUtil::isValidObjectPath(path)) {
fprintf(stderr, "Path '%s' is not a valid path name.\n", qPrintable(path));
- exit(1);
+ return 1;
}
if (args.isEmpty()) {
- listAllInterfaces(service, path);
- exit(0);
+ listAllInterfaces(service, path, connection);
+ return 0;
}
QString interface = args.takeFirst();
@@ -521,14 +521,13 @@ int main(int argc, char **argv)
}
if (!interface.isEmpty() && !QDBusUtil::isValidInterfaceName(interface)) {
fprintf(stderr, "Interface '%s' is not a valid interface name.\n", qPrintable(interface));
- exit(1);
+ return 1;
}
if (!QDBusUtil::isValidMemberName(member)) {
fprintf(stderr, "Method name '%s' is not a valid member name.\n", qPrintable(member));
- exit(1);
+ return 1;
}
- int ret = placeCall(service, path, interface, member, args);
- exit(ret);
+ return placeCall(service, path, interface, connection, member, args);
}
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