18 files changed, 177 insertions, 422 deletions

diff --git a/src/core/aspects/aspects.pri b/src/core/aspects/aspects.pri
index ced33f310..5e8327192 100644
--- a/src/core/aspects/aspects.pri
+++ b/src/core/aspects/aspects.pri
@@ -4,8 +4,7 @@ SOURCES += \
         $$PWD/qabstractaspect.cpp \
         $$PWD/qaspectengine.cpp \
         $$PWD/qaspectfactory.cpp \
-        $$PWD/qaspectmanager.cpp \
-        $$PWD/qaspectthread.cpp
+        $$PWD/qaspectmanager.cpp
 
 HEADERS += \
         $$PWD/qabstractaspect.h \
@@ -13,8 +12,7 @@ HEADERS += \
         $$PWD/qabstractaspect_p.h \
         $$PWD/qaspectengine_p.h \
         $$PWD/qaspectfactory_p.h \
-        $$PWD/qaspectmanager_p.h \
-        $$PWD/qaspectthread_p.h
+        $$PWD/qaspectmanager_p.h
 
 INCLUDEPATH += $$PWD
 
diff --git a/src/core/aspects/qaspectengine.cpp b/src/core/aspects/qaspectengine.cpp
index 222c4c2af..2e7e51247 100644
--- a/src/core/aspects/qaspectengine.cpp
+++ b/src/core/aspects/qaspectengine.cpp
@@ -47,7 +47,6 @@
 #include <QtCore/QMetaObject>
 
 #include <Qt3DCore/private/corelogging_p.h>
-#include <Qt3DCore/private/qaspectthread_p.h>
 #include <Qt3DCore/private/qaspectmanager_p.h>
 #include <Qt3DCore/private/qchangearbiter_p.h>
 #include <Qt3DCore/private/qeventfilterservice_p.h>
@@ -74,6 +73,7 @@ QAspectEnginePrivate *QAspectEnginePrivate::get(QAspectEngine *q)
 
 QAspectEnginePrivate::QAspectEnginePrivate()
     : QObjectPrivate()
+    , m_aspectManager(nullptr)
     , m_postman(nullptr)
     , m_scene(nullptr)
     , m_initialized(false)
@@ -185,8 +185,7 @@ QAspectEngine::QAspectEngine(QObject *parent)
     d->m_scene = new QScene(this);
     d->m_postman = new QPostman(this);
     d->m_postman->setScene(d->m_scene);
-    d->m_aspectThread = new QAspectThread(this);
-    d->m_aspectThread->waitForStart(QThread::HighestPriority);
+    d->m_aspectManager = new QAspectManager(this);
 }
 
 /*!
@@ -206,11 +205,6 @@ QAspectEngine::~QAspectEngine()
     for (auto aspect : aspects)
         unregisterAspect(aspect);
 
-    // Wait for thread to have completed it's final loop of execution
-    d->m_aspectThread->aspectManager()->quit();
-    d->m_aspectThread->wait();
-
-    delete d->m_aspectThread;
     delete d->m_postman;
     delete d->m_scene;
 }
@@ -225,15 +219,12 @@ void QAspectEnginePrivate::initNodeTree(QNode *node)
 
 void QAspectEnginePrivate::initialize()
 {
-    QChangeArbiter *arbiter = m_aspectThread->aspectManager()->changeArbiter();
+    m_aspectManager->initialize();
+    QChangeArbiter *arbiter = m_aspectManager->changeArbiter();
     m_scene->setArbiter(arbiter);
     QChangeArbiter::createUnmanagedThreadLocalChangeQueue(arbiter);
-    QMetaObject::invokeMethod(arbiter,
-                              "setPostman",
-                              Q_ARG(Qt3DCore::QAbstractPostman*, m_postman));
-    QMetaObject::invokeMethod(arbiter,
-                              "setScene",
-                              Q_ARG(Qt3DCore::QScene*, m_scene));
+    arbiter->setPostman(m_postman);
+    arbiter->setScene(m_scene);
     m_initialized = true;
 #if QT_CONFIG(qt3d_profile_jobs)
     m_commandDebugger->setAspectEngine(q_func());
@@ -263,14 +254,14 @@ void QAspectEnginePrivate::shutdown()
 
     // Cleanup the scene before quitting the backend
     m_scene->setArbiter(nullptr);
-    QChangeArbiter *arbiter = m_aspectThread->aspectManager()->changeArbiter();
+    QChangeArbiter *arbiter = m_aspectManager->changeArbiter();
     QChangeArbiter::destroyUnmanagedThreadLocalChangeQueue(arbiter);
     m_initialized = false;
 }
 
 void QAspectEnginePrivate::exitSimulationLoop()
 {
-    m_aspectThread->aspectManager()->exitSimulationLoop();
+    m_aspectManager->exitSimulationLoop();
 }
 
 /*!
@@ -285,12 +276,8 @@ void QAspectEngine::registerAspect(QAbstractAspect *aspect)
     // AspectManager::registerAspect is called in the context
     // of the AspectThread. This is turns call aspect->onInitialize
     // still in the same AspectThread context
-    aspect->moveToThread(d->m_aspectThread);
     d->m_aspects << aspect;
-    QMetaObject::invokeMethod(d->m_aspectThread->aspectManager(),
-                              "registerAspect",
-                              Qt::BlockingQueuedConnection,
-                              Q_ARG(Qt3DCore::QAbstractAspect*, aspect));
+    d->m_aspectManager->registerAspect(aspect);
 }
 
 /*!
@@ -327,10 +314,7 @@ void QAspectEngine::unregisterAspect(QAbstractAspect *aspect)
 
     // Tell the aspect manager to give the aspect a chance to do some cleanup
     // in its QAbstractAspect::onUnregistered() virtual
-    QMetaObject::invokeMethod(d->m_aspectThread->aspectManager(),
-                              "unregisterAspect",
-                              Qt::BlockingQueuedConnection,
-                              Q_ARG(Qt3DCore::QAbstractAspect*, aspect));
+    d->m_aspectManager->unregisterAspect(aspect);
 
     // Remove from our collection of named aspects (if present)
     const auto it = std::find_if(d->m_namedAspects.begin(), d->m_namedAspects.end(),
@@ -455,14 +439,9 @@ void QAspectEngine::setRootEntity(QEntityPtr root)
     // TODO: Pass the creation changes via the arbiter rather than relying upon
     // an invokeMethod call.
     qCDebug(Aspects) << "Begin setting scene root on aspect manager";
-    QMetaObject::invokeMethod(d->m_aspectThread->aspectManager(),
-                              "setRootEntity",
-                              Qt::BlockingQueuedConnection,
-                              Q_ARG(Qt3DCore::QEntity*, root.data()),
-                              Q_ARG(QVector<Qt3DCore::QNodeCreatedChangeBasePtr>, d->m_creationChanges));
+    d->m_aspectManager->setRootEntity(root.data(), d->m_creationChanges);
     qCDebug(Aspects) << "Done setting scene root on aspect manager";
-
-    d->m_aspectThread->aspectManager()->enterSimulationLoop();
+    d->m_aspectManager->enterSimulationLoop();
 }
 
 /*!
diff --git a/src/core/aspects/qaspectengine_p.h b/src/core/aspects/qaspectengine_p.h
index 2d7d0fe93..9c042b5a5 100644
--- a/src/core/aspects/qaspectengine_p.h
+++ b/src/core/aspects/qaspectengine_p.h
@@ -65,7 +65,7 @@ namespace Qt3DCore {
 class QEntity;
 class QNode;
 class QAspectEngine;
-class QAspectThread;
+class QAspectManager;
 class QPostman;
 class QScene;
 
@@ -84,7 +84,7 @@ public:
     Q_DECLARE_PUBLIC(QAspectEngine)
 
     QAspectFactory m_factory;
-    QAspectThread *m_aspectThread;
+    QAspectManager *m_aspectManager;
     QPostman *m_postman;
     QScene *m_scene;
     QSharedPointer<QEntity> m_root;
diff --git a/src/core/aspects/qaspectmanager.cpp b/src/core/aspects/qaspectmanager.cpp
index e9642116a..a028e38cb 100644
--- a/src/core/aspects/qaspectmanager.cpp
+++ b/src/core/aspects/qaspectmanager.cpp
@@ -61,6 +61,8 @@
 #include <Qt3DCore/private/qtickclock_p.h>
 #include <Qt3DCore/private/qtickclockservice_p.h>
 
+#include <QtCore/QCoreApplication>
+
 #if defined(QT3D_CORE_JOB_TIMING)
 #include <QElapsedTimer>
 #endif
@@ -69,6 +71,26 @@ QT_BEGIN_NAMESPACE
 
 namespace Qt3DCore {
 
+namespace  {
+
+class RequestFrameEvent : public QEvent
+{
+public:
+    RequestFrameEvent()
+        : QEvent(static_cast<QEvent::Type>(RequestFrameEvent::requestEventType))
+    {}
+
+    static int eventType() { return RequestFrameEvent::requestEventType; }
+
+private:
+    static int requestEventType;
+};
+
+int RequestFrameEvent::requestEventType = QEvent::registerEventType();
+
+} // anonymous
+
+
 /*!
     \class Qt3DCore::QAspectManager
     \internal
@@ -80,14 +102,9 @@ QAspectManager::QAspectManager(QObject *parent)
     , m_jobManager(new QAspectJobManager(this))
     , m_changeArbiter(new QChangeArbiter(this))
     , m_serviceLocator(new QServiceLocator())
-    , m_waitForEndOfSimulationLoop(0)
-    , m_waitForStartOfSimulationLoop(0)
-    , m_waitForEndOfExecLoop(0)
-    , m_waitForQuit(0)
+    , m_simulationLoopRunning(false)
 {
     qRegisterMetaType<QSurface *>("QSurface*");
-    m_runSimulationLoop.fetchAndStoreOrdered(0);
-    m_runMainLoop.fetchAndStoreOrdered(1);
     qCDebug(Aspects) << Q_FUNC_INFO;
 }
 
@@ -102,15 +119,26 @@ QAspectManager::~QAspectManager()
 void QAspectManager::enterSimulationLoop()
 {
     qCDebug(Aspects) << Q_FUNC_INFO;
-    m_runSimulationLoop.fetchAndStoreOrdered(1);
+    m_simulationLoopRunning = true;
 
-    // Wake up QAspectThread's event loop
-    thread()->eventDispatcher()->wakeUp();
+    // Retrieve the frame advance service. Defaults to timer based if there is no renderer.
+    QAbstractFrameAdvanceService *frameAdvanceService =
+            m_serviceLocator->service<QAbstractFrameAdvanceService>(QServiceLocator::FrameAdvanceService);
+
+    // Start the frameAdvanceService
+    frameAdvanceService->start();
+
+    // We are about to enter the simulation loop. Give aspects a chance to do any last
+    // pieces of initialization
+    qCDebug(Aspects) << "Calling onEngineStartup() for each aspect";
+    for (QAbstractAspect *aspect : qAsConst(m_aspects)) {
+        qCDebug(Aspects) << "\t" << aspect->objectName();
+        aspect->onEngineStartup();
+    }
+    qCDebug(Aspects) << "Done calling onEngineStartup() for each aspect";
 
-    // We wait for the setRootEntity on the aspectManager to have completed
-    // This ensures we cannot shutdown before the aspects have had a chance
-    // to be initialized
-    m_waitForStartOfSimulationLoop.acquire(1);
+    // Trigger event loop
+    requestNextFrame();
 }
 
 // Main thread (called by QAspectEngine)
@@ -119,7 +147,7 @@ void QAspectManager::exitSimulationLoop()
     qCDebug(Aspects) << Q_FUNC_INFO;
 
     // If this fails, simulation loop is already exited so nothing to do
-    if (!m_runSimulationLoop.testAndSetOrdered(1, 0)) {
+    if (!m_simulationLoopRunning) {
         qCDebug(Aspects) << "Simulation loop was not running. Nothing to do";
         return;
     }
@@ -141,17 +169,26 @@ void QAspectManager::exitSimulationLoop()
     for (QAbstractAspect *aspect : qAsConst(m_aspects))
         aspect->d_func()->onEngineAboutToShutdown();
 
+    // Process any pending changes from the frontend before we shut the aspects down
+    m_changeArbiter->syncChanges();
 
-    qCDebug(Aspects) << "exitSimulationLoop waiting for exec loop to terminate";
-    // Wait until the simulation loop is fully exited and the aspects are done
-    // processing any final changes and have had onEngineShutdown() called on them
-    m_waitForEndOfSimulationLoop.acquire(1);
+    // Give aspects a chance to perform any shutdown actions. This may include unqueuing
+    // any blocking work on the main thread that could potentially deadlock during shutdown.
+    qCDebug(Aspects) << "Calling onEngineShutdown() for each aspect";
+    for (QAbstractAspect *aspect : qAsConst(m_aspects)) {
+        qCDebug(Aspects) << "\t" << aspect->objectName();
+        aspect->onEngineShutdown();
+    }
+    qCDebug(Aspects) << "Done calling onEngineShutdown() for each aspect";
+
+
+    m_simulationLoopRunning = false;
     qCDebug(Aspects) << "exitSimulationLoop completed";
 }
 
 bool QAspectManager::isShuttingDown() const
 {
-    return !m_runSimulationLoop.load();
+    return !m_simulationLoopRunning;
 }
 
 /*!
@@ -184,7 +221,7 @@ void QAspectManager::shutdown()
     // Aspects must be deleted in the Thread they were created in
 }
 
-// QAspectThread:: queued invoked by QAspectEngine::setRootEntity
+// MainThread called by QAspectEngine::setRootEntity
 void QAspectManager::setRootEntity(Qt3DCore::QEntity *root, const QVector<Qt3DCore::QNodeCreatedChangeBasePtr> &changes)
 {
     qCDebug(Aspects) << Q_FUNC_INFO;
@@ -251,118 +288,6 @@ void QAspectManager::unregisterAspect(Qt3DCore::QAbstractAspect *aspect)
     qCDebug(Aspects) << "Completed unregistering aspect";
 }
 
-void QAspectManager::exec()
-{
-    // Gentlemen, start your engines
-    QEventLoop eventLoop;
-
-    // Enter the engine loop
-    qCDebug(Aspects) << Q_FUNC_INFO << "***** Entering main loop *****";
-    while (m_runMainLoop.load()) {
-        // Process events until we're told to start the simulation loop
-        while (m_runMainLoop.load() && !m_runSimulationLoop.load())
-            eventLoop.processEvents(QEventLoop::AllEvents | QEventLoop::WaitForMoreEvents);
-
-        if (!m_runSimulationLoop.load())
-            break;
-
-        // Retrieve the frame advance service. Defaults to timer based if there is no renderer.
-        QAbstractFrameAdvanceService *frameAdvanceService =
-                m_serviceLocator->service<QAbstractFrameAdvanceService>(QServiceLocator::FrameAdvanceService);
-
-        // Start the frameAdvanceService
-        frameAdvanceService->start();
-
-        // We are about to enter the simulation loop. Give aspects a chance to do any last
-        // pieces of initialization
-        qCDebug(Aspects) << "Calling onEngineStartup() for each aspect";
-        for (QAbstractAspect *aspect : qAsConst(m_aspects)) {
-            qCDebug(Aspects) << "\t" << aspect->objectName();
-            aspect->onEngineStartup();
-        }
-        qCDebug(Aspects) << "Done calling onEngineStartup() for each aspect";
-        m_waitForStartOfSimulationLoop.release(1);
-
-        // Only enter main simulation loop once the renderer and other aspects are initialized
-        while (m_runSimulationLoop.load()) {
-            qint64 t = frameAdvanceService->waitForNextFrame();
-
-            // Distribute accumulated changes. This includes changes sent from the frontend
-            // to the backend nodes. We call this before the call to m_scheduler->update() to ensure
-            // that any property changes do not set dirty flags in a data race with the renderer's
-            // submission thread which may be looking for dirty flags, acting upon them and then
-            // clearing the dirty flags.
-            //
-            // Doing this as the first call in the new frame ensures the lock free approach works
-            // without any such data race.
-#if QT_CONFIG(qt3d_profile_jobs)
-            const quint32 arbiterId = 4096;
-            JobRunStats changeArbiterStats;
-            changeArbiterStats.jobId.typeAndInstance[0] = arbiterId;
-            changeArbiterStats.jobId.typeAndInstance[1] = 0;
-            changeArbiterStats.threadId = reinterpret_cast<quint64>(QThread::currentThreadId());
-            changeArbiterStats.startTime = QThreadPooler::m_jobsStatTimer.nsecsElapsed();
-#endif
-            m_changeArbiter->syncChanges();
-#if QT_CONFIG(qt3d_profile_jobs)
-            changeArbiterStats.endTime = QThreadPooler::m_jobsStatTimer.nsecsElapsed();
-            QThreadPooler::addJobLogStatsEntry(changeArbiterStats);
-#endif
-
-            // For each Aspect
-            // Ask them to launch set of jobs for the current frame
-            // Updates matrices, bounding volumes, render bins ...
-#if defined(QT3D_CORE_JOB_TIMING)
-            QElapsedTimer timer;
-            timer.start();
-#endif
-            m_scheduler->scheduleAndWaitForFrameAspectJobs(t);
-#if defined(QT3D_CORE_JOB_TIMING)
-            qDebug() << "Jobs took" << timer.nsecsElapsed() / 1.0e6;
-#endif
-
-            // Process any pending events
-            eventLoop.processEvents();
-        } // End of simulation loop
-
-        // Process any pending changes from the frontend before we shut the aspects down
-        m_changeArbiter->syncChanges();
-
-        // Give aspects a chance to perform any shutdown actions. This may include unqueuing
-        // any blocking work on the main thread that could potentially deadlock during shutdown.
-        qCDebug(Aspects) << "Calling onEngineShutdown() for each aspect";
-        for (QAbstractAspect *aspect : qAsConst(m_aspects)) {
-            qCDebug(Aspects) << "\t" << aspect->objectName();
-            aspect->onEngineShutdown();
-        }
-        qCDebug(Aspects) << "Done calling onEngineShutdown() for each aspect";
-
-        // Wake up the main thread which is waiting for us inside of exitSimulationLoop()
-        m_waitForEndOfSimulationLoop.release(1);
-    } // End of main loop
-    qCDebug(Aspects) << Q_FUNC_INFO << "***** Exited main loop *****";
-
-    m_waitForEndOfExecLoop.release(1);
-    m_waitForQuit.acquire(1);
-}
-
-void QAspectManager::quit()
-{
-    qCDebug(Aspects) << Q_FUNC_INFO;
-
-    Q_ASSERT_X(m_runSimulationLoop.load() == 0, "QAspectManagr::quit()", "Inner loop is still running");
-    m_runMainLoop.fetchAndStoreOrdered(0);
-
-    // Wake up QAspectThread's event loop if needed
-    thread()->eventDispatcher()->wakeUp();
-
-    // We need to wait for the QAspectManager exec loop to terminate
-    m_waitForEndOfExecLoop.acquire(1);
-    m_waitForQuit.release(1);
-
-    qCDebug(Aspects) << Q_FUNC_INFO << "Exiting";
-}
-
 const QVector<QAbstractAspect *> &QAspectManager::aspects() const
 {
     return m_aspects;
@@ -383,7 +308,81 @@ QServiceLocator *QAspectManager::serviceLocator() const
     return m_serviceLocator.data();
 }
 
+/*!
+    \internal
+    \brief Drives the Qt3D simulation loop in the main thread
+ */
+bool QAspectManager::event(QEvent *e)
+{
+    if (e->type() == RequestFrameEvent::eventType()) {
+
+        // Process current frame
+        processFrame();
+
+        // Request next frame if we are still running
+        if (m_simulationLoopRunning)
+            requestNextFrame();
+    }
+
+    return QObject::event(e);
+}
+
+void QAspectManager::requestNextFrame()
+{
+    qCDebug(Aspects) << "Requesting new Frame";
+    // Post event in the event loop to force
+    // next frame to be processed
+    qApp->postEvent(this, new RequestFrameEvent());
+}
+
+void QAspectManager::processFrame()
+{
+    qCDebug(Aspects) << "Processing Frame";
+
+    // Retrieve the frame advance service. Defaults to timer based if there is no renderer.
+    QAbstractFrameAdvanceService *frameAdvanceService =
+            m_serviceLocator->service<QAbstractFrameAdvanceService>(QServiceLocator::FrameAdvanceService);
+
+    const qint64 t = frameAdvanceService->waitForNextFrame();
+
+    // Distribute accumulated changes. This includes changes sent from the frontend
+    // to the backend nodes. We call this before the call to m_scheduler->update() to ensure
+    // that any property changes do not set dirty flags in a data race with the renderer's
+    // submission thread which may be looking for dirty flags, acting upon them and then
+    // clearing the dirty flags.
+    //
+    // Doing this as the first call in the new frame ensures the lock free approach works
+    // without any such data race.
+#if QT_CONFIG(qt3d_profile_jobs)
+    const quint32 arbiterId = 4096;
+    JobRunStats changeArbiterStats;
+    changeArbiterStats.jobId.typeAndInstance[0] = arbiterId;
+    changeArbiterStats.jobId.typeAndInstance[1] = 0;
+    changeArbiterStats.threadId = reinterpret_cast<quint64>(QThread::currentThreadId());
+    changeArbiterStats.startTime = QThreadPooler::m_jobsStatTimer.nsecsElapsed();
+#endif
+    // TO DO: Having this done in the main thread actually means aspects could just
+    // as simply read info out of the Frontend classes without risk of introducing
+    // races. This could therefore be removed for Qt 6.
+    m_changeArbiter->syncChanges();
+#if QT_CONFIG(qt3d_profile_jobs)
+    changeArbiterStats.endTime = QThreadPooler::m_jobsStatTimer.nsecsElapsed();
+    QThreadPooler::addJobLogStatsEntry(changeArbiterStats);
+#endif
+
+    // For each Aspect
+    // Ask them to launch set of jobs for the current frame
+    // Updates matrices, bounding volumes, render bins ...
+#if defined(QT3D_CORE_JOB_TIMING)
+    QElapsedTimer timer;
+    timer.start();
+#endif
+    m_scheduler->scheduleAndWaitForFrameAspectJobs(t);
+#if defined(QT3D_CORE_JOB_TIMING)
+    qDebug() << "Jobs took" << timer.nsecsElapsed() / 1.0e6;
+#endif
+}
+
 } // namespace Qt3DCore
 
 QT_END_NAMESPACE
-
diff --git a/src/core/aspects/qaspectmanager_p.h b/src/core/aspects/qaspectmanager_p.h
index de978b8e9..1c07ab797 100644
--- a/src/core/aspects/qaspectmanager_p.h
+++ b/src/core/aspects/qaspectmanager_p.h
@@ -95,9 +95,6 @@ public Q_SLOTS:
     void registerAspect(Qt3DCore::QAbstractAspect *aspect);
     void unregisterAspect(Qt3DCore::QAbstractAspect *aspect);
 
-    void exec();
-    void quit();
-
 public:
     const QVector<QAbstractAspect *> &aspects() const;
     QAbstractAspectJobManager *jobManager() const;
@@ -105,19 +102,20 @@ public:
     QServiceLocator *serviceLocator() const;
 
 private:
+    bool event(QEvent *event) override;
+    void requestNextFrame();
+    void processFrame();
+
     QVector<QAbstractAspect *> m_aspects;
     QEntity *m_root;
     QVariantMap m_data;
     QScheduler *m_scheduler;
     QAbstractAspectJobManager *m_jobManager;
     QChangeArbiter *m_changeArbiter;
-    QAtomicInt m_runSimulationLoop;
-    QAtomicInt m_runMainLoop;
     QScopedPointer<QServiceLocator> m_serviceLocator;
-    QSemaphore m_waitForEndOfSimulationLoop;
-    QSemaphore m_waitForStartOfSimulationLoop;
-    QSemaphore m_waitForEndOfExecLoop;
-    QSemaphore m_waitForQuit;
+    bool m_mainLoopRunning;
+    bool m_simulationLoopRunning;
+
 };
 
 } // namespace Qt3DCore
diff --git a/src/core/aspects/qaspectthread.cpp b/src/core/aspects/qaspectthread.cpp
deleted file mode 100644
index 31715b04e..000000000
--- a/src/core/aspects/qaspectthread.cpp
+++ /dev/null
@@ -1,99 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the Qt3D module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qaspectthread_p.h"
-
-#include <QtCore/QMutexLocker>
-
-#include <Qt3DCore/private/qaspectmanager_p.h>
-#include <Qt3DCore/private/corelogging_p.h>
-
-QT_BEGIN_NAMESPACE
-
-namespace Qt3DCore {
-
-QAspectThread::QAspectThread(QObject *parent)
-    : QThread(parent),
-      m_aspectManager(nullptr),
-      m_semaphore(0)
-{
-    qCDebug(Aspects) << Q_FUNC_INFO;
-}
-
-QAspectThread::~QAspectThread()
-{
-}
-
-void QAspectThread::waitForStart(Priority priority)
-{
-    qCDebug(Aspects) << "Starting QAspectThread and going to sleep until it is ready for us...";
-    start(priority);
-    m_semaphore.acquire();
-    qCDebug(Aspects) << "QAspectThead is now ready & calling thread is now awake again";
-}
-
-void QAspectThread::run()
-{
-    qCDebug(Aspects) << "Entering void QAspectThread::run()";
-
-    m_aspectManager = new QAspectManager;
-
-    // Load and initialize the aspects and any other core services
-    // Done before releasing condition to make sure that Qml Components
-    // Are exposed prior to Qml Engine source being set
-    m_aspectManager->initialize();
-
-    // Wake up the calling thread now that our worker objects are ready for action
-    m_semaphore.release();
-
-    // Enter the main loop
-    m_aspectManager->exec();
-
-    // Clean up
-    m_aspectManager->shutdown();
-
-    // Delete the aspect manager while we're still in the thread
-    delete m_aspectManager;
-
-    qCDebug(Aspects) << "Exiting void QAspectThread::run()";
-}
-
-} // namespace Qt3DCore
-
-QT_END_NAMESPACE
diff --git a/src/core/aspects/qaspectthread_p.h b/src/core/aspects/qaspectthread_p.h
deleted file mode 100644
index 8ae9ff86d..000000000
--- a/src/core/aspects/qaspectthread_p.h
+++ /dev/null
@@ -1,88 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the Qt3D module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QT3DCORE_QASPECTTHREAD_P_H
-#define QT3DCORE_QASPECTTHREAD_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists for the convenience
-// of other Qt classes.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <Qt3DCore/qt3dcore_global.h>
-#include <QtCore/QSemaphore>
-#include <QtCore/QThread>
-
-
-QT_BEGIN_NAMESPACE
-
-namespace Qt3DCore {
-
-class QAspectManager;
-
-class QAspectThread : public QThread
-{
-    Q_OBJECT
-public:
-    explicit QAspectThread(QObject *parent = 0);
-    ~QAspectThread();
-
-    void waitForStart(Priority priority);
-
-    QAspectManager *aspectManager() const { return m_aspectManager; }
-
-protected:
-    void run() override;
-
-private:
-    QAspectManager *m_aspectManager;
-    QSemaphore m_semaphore;
-};
-
-} // namespace Qt3DCore
-
-QT_END_NAMESPACE
-
-#endif // QT3DCORE_QASPECTTHREAD_P_H
diff --git a/src/core/qchangearbiter_p.h b/src/core/qchangearbiter_p.h
index 1f453ff56..c7d96b593 100644
--- a/src/core/qchangearbiter_p.h
+++ b/src/core/qchangearbiter_p.h
@@ -109,8 +109,8 @@ public:
     void sceneChangeEventWithLock(const QSceneChangePtr &e) override; // QLockableObserverInterface impl
     void sceneChangeEventWithLock(const QSceneChangeList &e) override; // QLockableObserverInterface impl
 
-    Q_INVOKABLE void setPostman(Qt3DCore::QAbstractPostman *postman);
-    Q_INVOKABLE void setScene(Qt3DCore::QScene *scene);
+    void setPostman(Qt3DCore::QAbstractPostman *postman);
+    void setScene(Qt3DCore::QScene *scene);
 
     QAbstractPostman *postman() const final;
     QScene *scene() const;
diff --git a/src/core/services/qdownloadhelperservice.cpp b/src/core/services/qdownloadhelperservice.cpp
index 4cd89c5d0..deddf3ae0 100644
--- a/src/core/services/qdownloadhelperservice.cpp
+++ b/src/core/services/qdownloadhelperservice.cpp
@@ -39,10 +39,10 @@
 
 #include "qdownloadhelperservice_p.h"
 #include "qdownloadnetworkworker_p.h"
+#include <QtCore/QThread>
 #include <Qt3DCore/QAspectEngine>
 #include <Qt3DCore/private/qabstractserviceprovider_p.h>
 #include <Qt3DCore/private/qaspectengine_p.h>
-#include <Qt3DCore/private/qaspectthread_p.h>
 #include <Qt3DCore/private/qaspectmanager_p.h>
 #include <Qt3DCore/private/qservicelocator_p.h>
 
@@ -196,7 +196,7 @@ QString QDownloadHelperService::urlToLocalFileOrQrc(const QUrl &url)
 QDownloadHelperService *QDownloadHelperService::getService(QAspectEngine *engine)
 {
     auto enginePrivate = Qt3DCore::QAspectEnginePrivate::get(engine);
-    return enginePrivate->m_aspectThread->aspectManager()->serviceLocator()->downloadHelperService();
+    return enginePrivate->m_aspectManager->serviceLocator()->downloadHelperService();
 }
 
 bool QDownloadHelperService::isLocal(const QUrl &url)
diff --git a/src/input/backend/eventsourcesetterhelper.cpp b/src/input/backend/eventsourcesetterhelper.cpp
index bbc7ea54c..fe800a1a4 100644
--- a/src/input/backend/eventsourcesetterhelper.cpp
+++ b/src/input/backend/eventsourcesetterhelper.cpp
@@ -56,21 +56,21 @@ EventSourceSetterHelper::EventSourceSetterHelper(InputHandler *inputHandler)
 {
 }
 
-// Aspect thread
+// Main thread
 void EventSourceSetterHelper::setEventFilterService(Qt3DCore::QEventFilterService *service)
 {
-    QMutexLocker lock(&m_mutex);
     m_service = service;
 }
 
-// Any thread
+// Main thread
 void EventSourceSetterHelper::setEventSource(QObject *eventSource)
 {
     if (eventSource && m_lastEventSource != eventSource) {
-        QMetaObject::invokeMethod(this,
-                                  "setEventSourceHelper",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_ARG(QObject*, eventSource));
+        if (m_service) {
+            m_service->initialize(eventSource);
+            m_inputHandler->registerEventFilters(m_service);
+            m_lastEventSource = eventSource;
+        }
     }
 }
 
@@ -83,17 +83,6 @@ void EventSourceSetterHelper::unsetEventSource(QObject *eventSource)
     }
 }
 
-// Main Thread
-void EventSourceSetterHelper::setEventSourceHelper(QObject *eventSource)
-{
-    QMutexLocker lock(&m_mutex);
-    if (m_service) {
-        m_service->initialize(eventSource);
-        m_inputHandler->registerEventFilters(m_service);
-        m_lastEventSource = eventSource;
-    }
-}
-
 } // Input
 
 } // Qt3DInput
diff --git a/src/input/backend/eventsourcesetterhelper_p.h b/src/input/backend/eventsourcesetterhelper_p.h
index 48418f1b9..b8800d8a6 100644
--- a/src/input/backend/eventsourcesetterhelper_p.h
+++ b/src/input/backend/eventsourcesetterhelper_p.h
@@ -75,14 +75,10 @@ public:
     // Called from aspect thread
     void setEventFilterService(Qt3DCore::QEventFilterService *service);
 
-    // Called from any thread
+    // Called from main thread
     void setEventSource(QObject *eventSource);
     void unsetEventSource(QObject *eventSource);
 
-private Q_SLOTS:
-    // Called in main thread
-    void setEventSourceHelper(QObject *);
-
 private:
     Qt3DCore::QEventFilterService *m_service;
     InputHandler *m_inputHandler;
diff --git a/src/input/backend/inputhandler.cpp b/src/input/backend/inputhandler.cpp
index 18559e9d4..9484909ab 100644
--- a/src/input/backend/inputhandler.cpp
+++ b/src/input/backend/inputhandler.cpp
@@ -127,58 +127,55 @@ void InputHandler::unregisterEventFilters(Qt3DCore::QEventFilterService *service
 // Called by the keyboardEventFilter in the main thread
 void InputHandler::appendKeyEvent(const QT_PREPEND_NAMESPACE(QKeyEvent) &event)
 {
-    QMutexLocker lock(&m_mutex);
     m_pendingKeyEvents.append(event);
 }
 
-// Called by QInputASpect::jobsToExecute (aspectThread)
+// Called by QInputASpect::jobsToExecute (Main Thread)
 QList<QT_PREPEND_NAMESPACE(QKeyEvent)> InputHandler::pendingKeyEvents()
 {
-    QMutexLocker lock(&m_mutex);
     return std::move(m_pendingKeyEvents);
 }
 
-// Called by QInputASpect::jobsToExecute (aspectThread)
+// Called by QInputASpect::jobsToExecute (Main Thread)
 void InputHandler::clearPendingKeyEvents()
 {
-    QMutexLocker lock(&m_mutex);
     m_pendingKeyEvents.clear();
 }
 
+// Main Thread
 void InputHandler::appendMouseEvent(const QT_PREPEND_NAMESPACE(QMouseEvent) &event)
 {
-    QMutexLocker lock(&m_mutex);
     m_pendingMouseEvents.append(event);
 }
 
+// Main Thread
 QList<QT_PREPEND_NAMESPACE(QMouseEvent)> InputHandler::pendingMouseEvents()
 {
-    QMutexLocker lock(&m_mutex);
     return std::move(m_pendingMouseEvents);
 }
 
+// Main Thread
 void InputHandler::clearPendingMouseEvents()
 {
-    QMutexLocker lock(&m_mutex);
     m_pendingMouseEvents.clear();
 }
 
 #if QT_CONFIG(wheelevent)
+// Main Thread
 void InputHandler::appendWheelEvent(const QT_PREPEND_NAMESPACE(QWheelEvent) &event)
 {
-    QMutexLocker lock(&m_mutex);
     m_pendingWheelEvents.append(event);
 }
 
+// Main Thread
 QList<QT_PREPEND_NAMESPACE (QWheelEvent)> Qt3DInput::Input::InputHandler::pendingWheelEvents()
 {
-    QMutexLocker lock(&m_mutex);
     return std::move(m_pendingWheelEvents);
 }
 
+// Main Thread
 void InputHandler::clearPendingWheelEvents()
 {
-    QMutexLocker lock(&m_mutex);
     m_pendingWheelEvents.clear();
 }
 #endif
@@ -253,7 +250,6 @@ QVector<Qt3DCore::QAspectJobPtr> InputHandler::mouseJobs()
 #if QT_CONFIG(wheelevent)
     const QList<QT_PREPEND_NAMESPACE(QWheelEvent)> wheelEvents = pendingWheelEvents();
 #endif
-
     for (const HMouseDevice &cHandle : qAsConst(m_activeMouseDevices)) {
         MouseDevice *controller = m_mouseDeviceManager->data(cHandle);
 
diff --git a/src/input/backend/mousedevice.cpp b/src/input/backend/mousedevice.cpp
index 128988637..e285783b7 100644
--- a/src/input/backend/mousedevice.cpp
+++ b/src/input/backend/mousedevice.cpp
@@ -150,6 +150,7 @@ void MouseDevice::updateWheelEvents(const QList<QT_PREPEND_NAMESPACE (QWheelEven
 }
 #endif
 
+// Main Thread
 void MouseDevice::updateMouseEvents(const QList<QT_PREPEND_NAMESPACE(QMouseEvent)> &events)
 {
     // Reset axis values before we accumulate new values for this frame
diff --git a/src/logic/executor.cpp b/src/logic/executor.cpp
index 6134e801e..1c428db47 100644
--- a/src/logic/executor.cpp
+++ b/src/logic/executor.cpp
@@ -64,8 +64,6 @@ void Executor::clearQueueAndProceed()
     // If the semaphore is acquired, release it to allow the logic job and hence the
     // manager and frame to complete and shutdown to continue.
     m_nodeIds.clear();
-    if (m_semaphore->available() == 0)
-        m_semaphore->release();
 }
 
 void Executor::enqueueLogicFrameUpdates(const QVector<Qt3DCore::QNodeId> &nodeIds)
@@ -92,16 +90,12 @@ bool Executor::event(QEvent *e)
 void Executor::processLogicFrameUpdates(float dt)
 {
     Q_ASSERT(m_scene);
-    Q_ASSERT(m_semaphore);
     const QVector<QNode *> nodes = m_scene->lookupNodes(m_nodeIds);
     for (QNode *node : nodes) {
         QFrameAction *frameAction = qobject_cast<QFrameAction *>(node);
         if (frameAction && frameAction->isEnabled())
             frameAction->onTriggered(dt);
     }
-
-    // Release the semaphore so the calling Manager can continue
-    m_semaphore->release();
 }
 
 } // namespace Logic
diff --git a/src/logic/executor_p.h b/src/logic/executor_p.h
index e33ff842e..27b9c60c8 100644
--- a/src/logic/executor_p.h
+++ b/src/logic/executor_p.h
@@ -87,7 +87,6 @@ public:
     explicit Executor(QObject *parent = 0);
 
     void setScene(Qt3DCore::QScene *scene) { m_scene = scene; }
-    void setSemephore(QSemaphore *semaphore) { m_semaphore = semaphore; }
     void clearQueueAndProceed();
 
 public Q_SLOTS:
@@ -100,7 +99,6 @@ protected:
 private:
     QVector<Qt3DCore::QNodeId> m_nodeIds;
     Qt3DCore::QScene *m_scene;
-    QSemaphore *m_semaphore;
 };
 
 } // namespace Logic
diff --git a/src/logic/manager.cpp b/src/logic/manager.cpp
index e10ace592..3d096a342 100644
--- a/src/logic/manager.cpp
+++ b/src/logic/manager.cpp
@@ -56,10 +56,8 @@ namespace Logic {
 
 Manager::Manager()
     : m_logicHandlerManager(new HandlerManager)
-    , m_semaphore(1)
     , m_dt(0.0f)
 {
-    m_semaphore.acquire();
 }
 
 Manager::~Manager()
@@ -69,8 +67,6 @@ Manager::~Manager()
 void Manager::setExecutor(Executor *executor)
 {
     m_executor = executor;
-    if (m_executor)
-        m_executor->setSemephore(&m_semaphore);
 }
 
 void Manager::appendHandler(Handler *handler)
@@ -93,6 +89,7 @@ bool Manager::hasFrameActions() const
     return m_logicHandlers.count() > 0;
 }
 
+// Called from Job Thread
 void Manager::triggerLogicFrameUpdates()
 {
     Q_ASSERT(m_executor);
@@ -107,7 +104,6 @@ void Manager::triggerLogicFrameUpdates()
     // release the semaphore when it has completed its work.
     m_executor->enqueueLogicFrameUpdates(m_logicComponentIds);
     qApp->postEvent(m_executor, new FrameUpdateEvent(m_dt));
-    m_semaphore.acquire();
 }
 
 } // namespace Logic
diff --git a/src/logic/manager_p.h b/src/logic/manager_p.h
index 918bd57e0..e4fa08a47 100644
--- a/src/logic/manager_p.h
+++ b/src/logic/manager_p.h
@@ -95,7 +95,6 @@ private:
     QVector<Qt3DCore::QNodeId> m_logicComponentIds;
     QLogicAspect *m_logicAspect;
     Executor *m_executor;
-    QSemaphore m_semaphore;
     float m_dt;
 };
 
diff --git a/tests/benchmarks/render/jobs/tst_bench_jobs.cpp b/tests/benchmarks/render/jobs/tst_bench_jobs.cpp
index 454cb9f6a..b1597b095 100644
--- a/tests/benchmarks/render/jobs/tst_bench_jobs.cpp
+++ b/tests/benchmarks/render/jobs/tst_bench_jobs.cpp
@@ -48,7 +48,6 @@
 #include <Qt3DCore/private/qaspectjobmanager_p.h>
 #include <Qt3DCore/private/qaspectengine_p.h>
 #include <Qt3DCore/private/qaspectmanager_p.h>
-#include <Qt3DCore/private/qaspectthread_p.h>
 #include <Qt3DCore/private/qnodevisitor_p.h>
 #include <Qt3DCore/private/qnodecreatedchangegenerator_p.h>
 #include <QQmlComponent>