diff options
author | Thiago Macieira <thiago.macieira@intel.com> | 2016-09-06 11:41:00 -0700 |
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committer | Thiago Macieira <thiago.macieira@intel.com> | 2016-09-16 04:11:54 +0000 |
commit | ebf0b121084822ce754c14ed7255bde0f90bf42f (patch) | |
tree | e9a4dca4498580c43f0a2ad39eb75ed093210393 /src | |
parent | 469d68b344380c1a9ccef95bb784b39a436a7634 (diff) |
Make QDBusConnectionPrivate::relaySignal be called in the right thread
This function sends D-Bus messages directly (in huntAndEmit), so it
should only be called from the QDBusConnectionManager thread. Somehow, I
missed this in the Qt 5.6 refactoring of QtDBus.
Being called in the wrong thread means that there's a visible behavior
change compared to Qt 5.5: if the user code sent a method call or method
return/error and then emitted a signal, we'd have two threads racing to
send the D-Bus messages. This was observed in Telepathy-Qt code: certain
signals arrived before a method return, even though they were clearly
emitted by a queued QMetaObject::invokeMethod.
In addition to that, we have has an internal problem (though not
observed): the libdbus-1 timer and socket callbacks would be called in
the wrong thread and we no longer have protection against that.
Unit testing not possible since this is a race condition.
Change-Id: I9e96ecd4f6aa4ff0ae08fffd1471d002142613d6
Reviewed-by: Gustavo Pichorim Boiko <gustavo.boiko@canonical.com>
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>
Diffstat (limited to 'src')
-rw-r--r-- | src/dbus/qdbusintegrator.cpp | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/src/dbus/qdbusintegrator.cpp b/src/dbus/qdbusintegrator.cpp index 878a58294c..c2cf7f41e4 100644 --- a/src/dbus/qdbusintegrator.cpp +++ b/src/dbus/qdbusintegrator.cpp @@ -1257,6 +1257,7 @@ void QDBusConnectionPrivate::relaySignal(QObject *obj, const QMetaObject *mo, in break; } + checkThread(); QDBusReadLocker locker(RelaySignalAction, this); QDBusMessage message = QDBusMessage::createSignal(QLatin1String("/"), interface, QLatin1String(memberName)); @@ -2368,12 +2369,9 @@ void QDBusConnectionPrivate::registerObject(const ObjectTreeNode *node) connector->connectAllSignals(node->obj); } - // disconnect and reconnect to avoid duplicates - connector->disconnect(SIGNAL(relaySignal(QObject*,const QMetaObject*,int,QVariantList)), - this, SLOT(relaySignal(QObject*,const QMetaObject*,int,QVariantList))); connect(connector, SIGNAL(relaySignal(QObject*,const QMetaObject*,int,QVariantList)), this, SLOT(relaySignal(QObject*,const QMetaObject*,int,QVariantList)), - Qt::DirectConnection); + Qt::ConnectionType(Qt::QueuedConnection | Qt::UniqueConnection)); } } |