From e354bdc5cbe33621def2b200f01d6376291570fc Mon Sep 17 00:00:00 2001 From: Dave Andrews Date: Mon, 22 Aug 2016 22:34:06 -0400 Subject: Fix asynchronous method calls on QObjects in different threads Use QMetaMethod::invoke without a return for void method calls, which allows making asynchronous method calls onto QObjects in different affinities than the QWebChannel that's emitting them. Also adds a unit test called testAsyncObject that intentionally places a QObject in a different affinity and then tests calls into it from the QWebChannel's synchronous publisher. Task-number: QTBUG-47678 Change-Id: I6c35ee54f764c0fc1b0431fb0774aa7e75039abf Reviewed-by: Dave Andrews Reviewed-by: Milian Wolff --- src/webchannel/qmetaobjectpublisher.cpp | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) (limited to 'src') diff --git a/src/webchannel/qmetaobjectpublisher.cpp b/src/webchannel/qmetaobjectpublisher.cpp index cd6ad70..85a9b35 100644 --- a/src/webchannel/qmetaobjectpublisher.cpp +++ b/src/webchannel/qmetaobjectpublisher.cpp @@ -368,22 +368,26 @@ QVariant QMetaObjectPublisher::invokeMethod(QObject *const object, const int met for (int i = 0; i < qMin(args.size(), method.parameterCount()); ++i) { arguments[i].value = toVariant(args.at(i), method.parameterType(i)); } - // construct QGenericReturnArgument QVariant returnValue; - if (method.returnType() != qMetaTypeId() && method.returnType() != qMetaTypeId()) { + if (method.returnType() == QMetaType::Void) { + // Skip return for void methods (prevents runtime warnings inside Qt), and allows + // QMetaMethod to invoke void-returning methods on QObjects in a different thread. + method.invoke(object, + arguments[0], arguments[1], arguments[2], arguments[3], arguments[4], + arguments[5], arguments[6], arguments[7], arguments[8], arguments[9]); + } else { + QGenericReturnArgument returnArgument(method.typeName(), returnValue.data()); + // Only init variant with return type if its not a variant itself, which would // lead to nested variants which is not what we want. - // Also, skip void-return types for obvious reasons (and to prevent a runtime warning inside Qt). - returnValue = QVariant(method.returnType(), 0); - } - QGenericReturnArgument returnArgument(method.typeName(), returnValue.data()); - - // now we can call the method - method.invoke(object, returnArgument, + if (method.returnType() != QMetaType::QVariant) + returnValue = QVariant(method.returnType(), 0); + method.invoke(object, returnArgument, arguments[0], arguments[1], arguments[2], arguments[3], arguments[4], arguments[5], arguments[6], arguments[7], arguments[8], arguments[9]); - + } + // now we can call the method return returnValue; } -- cgit v1.2.1 From 7cb2d467c3421eced44ae7b887b8738cc68595fc Mon Sep 17 00:00:00 2001 From: Dave Andrews Date: Mon, 22 Aug 2016 22:43:55 -0400 Subject: Fix asynchronous signals from QObjects in different threads Switches the signal listener in QWebChannel from using Qt::DirectConnection to Qt::AutoConnection to relay signals from QObjects in different affinities than the QWebChannel. Also adds a unit test in testAsyncObject() to verify that QWebChannel no longer crashes when receiving such a signal, and that such objects can be added and removed dynamically. Task-number: QTBUG-51366 Change-Id: I51a4886286fec9257a21ea95360c1ea8889a584a Reviewed-by: Dave Andrews Reviewed-by: Milian Wolff --- src/webchannel/signalhandler_p.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src') diff --git a/src/webchannel/signalhandler_p.h b/src/webchannel/signalhandler_p.h index 971c1c9..0f99c5c 100644 --- a/src/webchannel/signalhandler_p.h +++ b/src/webchannel/signalhandler_p.h @@ -178,7 +178,7 @@ void SignalHandler::connectTo(const QObject *object, const int signalI } // otherwise not yet connected, do so now static const int memberOffset = QObject::staticMetaObject.methodCount(); - QMetaObject::Connection connection = QMetaObject::connect(object, signal.methodIndex(), this, memberOffset + signalIndex, Qt::DirectConnection, 0); + QMetaObject::Connection connection = QMetaObject::connect(object, signal.methodIndex(), this, memberOffset + signalIndex, Qt::AutoConnection, 0); if (!connection) { qWarning() << "SignalHandler: QMetaObject::connect returned false. Unable to connect to" << object << signal.name() << signal.methodSignature(); return; -- cgit v1.2.1