47 files changed, 283 insertions, 301 deletions
diff --git a/src/plugins/qmltooling/qmldbg_profiler/qqmlprofilerservice.cpp b/src/plugins/qmltooling/qmldbg_profiler/qqmlprofilerservice.cpp
index 614890a8fd..c84ba7269a 100644
--- a/src/plugins/qmltooling/qmldbg_profiler/qqmlprofilerservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_profiler/qqmlprofilerservice.cpp
@@ -92,11 +92,11 @@ void QQmlProfilerServiceImpl::engineAboutToBeAdded(QJSEngine *engine)
 
     QMutexLocker lock(&m_configMutex);
     if (QQmlEngine *qmlEngine = qobject_cast<QQmlEngine *>(engine)) {
-        QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(qmlEngine);
-        QQmlProfilerAdapter *qmlAdapter = new QQmlProfilerAdapter(this, enginePrivate);
+        QQmlProfilerAdapter *qmlAdapter
+                = new QQmlProfilerAdapter(this, QQmlEnginePrivate::get(qmlEngine));
         addEngineProfiler(qmlAdapter, engine);
         QQmlProfilerAdapter *compileAdapter
-                = new QQmlProfilerAdapter(this, &(enginePrivate->typeLoader));
+                = new QQmlProfilerAdapter(this, QQmlTypeLoader::get(engine));
         addEngineProfiler(compileAdapter, engine);
     }
     QV4ProfilerAdapter *v4Adapter = new QV4ProfilerAdapter(this, engine->handle());
diff --git a/src/qml/jsapi/qjsengine_p.h b/src/qml/jsapi/qjsengine_p.h
index 0ab893d02a..c1f7895549 100644
--- a/src/qml/jsapi/qjsengine_p.h
+++ b/src/qml/jsapi/qjsengine_p.h
@@ -35,9 +35,11 @@ class Q_QML_EXPORT QJSEnginePrivate : public QObjectPrivate
     Q_DECLARE_PUBLIC(QJSEngine)
 
 public:
-    static QJSEnginePrivate* get(QJSEngine*e) { return e->d_func(); }
+    static QJSEnginePrivate *get(QJSEngine*e) { return e->d_func(); }
     static const QJSEnginePrivate* get(const QJSEngine*e) { return e->d_func(); }
-    static QJSEnginePrivate* get(QV4::ExecutionEngine *e);
+    static QJSEngine *get(QJSEnginePrivate *e) { return e->q_func(); }
+    static const QJSEngine *get(const QJSEnginePrivate *e) { return e->q_func(); }
+    static QJSEnginePrivate *get(QV4::ExecutionEngine *e);
 
     QJSEnginePrivate() = default;
     ~QJSEnginePrivate() override;
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 82e653a645..1f27ca1f1e 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -856,6 +856,10 @@ ExecutionEngine::ExecutionEngine(QJSEngine *jsEngine)
 
 ExecutionEngine::~ExecutionEngine()
 {
+#if QT_CONFIG(qml_network)
+    delete networkAccessManager;
+#endif
+    m_typeLoader.reset();
     qDeleteAll(m_extensionData);
     delete m_multiplyWrappedQObjects;
     m_multiplyWrappedQObjects = nullptr;
@@ -884,6 +888,15 @@ ExecutionEngine::~ExecutionEngine()
 #endif
 }
 
+#if QT_CONFIG(qml_network)
+QNetworkAccessManager *ExecutionEngine::getNetworkAccessManager()
+{
+    if (!networkAccessManager)
+        networkAccessManager = typeLoader()->createNetworkAccessManager(nullptr);
+    return networkAccessManager;
+}
+#endif
+
 #if QT_CONFIG(qml_debug)
 void ExecutionEngine::setDebugger(Debugging::Debugger *debugger)
 {
@@ -2194,13 +2207,10 @@ ExecutionEngine::Module ExecutionEngine::registerNativeModule(
         return Module();
 
     QQmlRefPointer<CompiledData::CompilationUnit> cu;
-    if (m_qmlEngine) {
-        // Make sure the type loader doesn't try to resolve the module anymore.
-        // If some other code requests that same module, we need to produce the same CU.
-        cu = QQmlEnginePrivate::get(m_qmlEngine)->typeLoader.injectModule(url, unit);
-    } else {
-        cu = QQml::makeRefPointer<CompiledData::CompilationUnit>(unit);
-    }
+
+    // Make sure the type loader doesn't try to resolve the module anymore.
+    // If some other code requests that same module, we need to produce the same CU.
+    cu = typeLoader()->injectModule(url, unit);
 
     QQmlRefPointer<ExecutableCompilationUnit> newModule = insertCompilationUnit(std::move(cu));
 
@@ -2956,11 +2966,4 @@ int ExecutionEngine::registerExtension()
     return registrationData()->extensionCount++;
 }
 
-#if QT_CONFIG(qml_network)
-QNetworkAccessManager *QV4::detail::getNetworkAccessManager(ExecutionEngine *engine)
-{
-    return engine->qmlEngine()->networkAccessManager();
-}
-#endif // qml_network
-
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index 764a796f9d..8c1c12e543 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -57,16 +57,8 @@ QT_BEGIN_NAMESPACE
 
 #if QT_CONFIG(qml_network)
 class QNetworkAccessManager;
-
-namespace QV4 {
-struct QObjectMethod;
-namespace detail {
-QNetworkAccessManager *getNetworkAccessManager(ExecutionEngine *engine);
-}
-}
-#else
-namespace QV4 { struct QObjectMethod; }
 #endif // qml_network
+namespace QV4 { struct QObjectMethod; }
 
 // Used to allow a QObject method take and return raw V4 handles without having to expose
 // 48 in the public API.
@@ -176,9 +168,9 @@ public:
     template<typename TypeLoader = QQmlTypeLoader>
     TypeLoader *typeLoader()
     {
-        if (m_qmlEngine)
-            return TypeLoader::get(m_qmlEngine);
-        return nullptr;
+        if (!m_typeLoader)
+            m_typeLoader = std::make_unique<TypeLoader>(this);
+        return m_typeLoader.get();
     }
 
     enum JSObjects {
@@ -359,7 +351,8 @@ public:
     FunctionObject *thrower() const { return reinterpret_cast<FunctionObject *>(jsObjects + ThrowerObject); }
 
 #if QT_CONFIG(qml_network)
-    QNetworkAccessManager* (*networkAccessManager)(ExecutionEngine*)  = detail::getNetworkAccessManager;
+    QNetworkAccessManager *getNetworkAccessManager();
+    QNetworkAccessManager *networkAccessManager = nullptr;
 #endif
 
     enum JSStrings {
@@ -866,6 +859,7 @@ private:
     void *m_xmlHttpRequestData = nullptr;
 #endif
 
+    std::unique_ptr<QQmlTypeLoader> m_typeLoader;
     QQmlEngine *m_qmlEngine = nullptr;
 
     QQmlDelayedCallQueue m_delayedCallQueue;
diff --git a/src/qml/jsruntime/qv4qmlcontext.cpp b/src/qml/jsruntime/qv4qmlcontext.cpp
index baef0b4864..4d29d6b890 100644
--- a/src/qml/jsruntime/qv4qmlcontext.cpp
+++ b/src/qml/jsruntime/qv4qmlcontext.cpp
@@ -201,7 +201,7 @@ ReturnedValue QQmlContextWrapper::getPropertyAndBase(const QQmlContextWrapper *r
     if (context->imports() && (name->startsWithUpper() || context->valueTypesAreAddressable())) {
         // Search for attached properties, enums and imported scripts
         QQmlTypeNameCache::Result r = context->imports()->query<QQmlImport::AllowRecursion>(
-                name, QQmlTypeLoader::get(ep));
+                name, v4->typeLoader());
 
         if (r.isValid()) {
             if (hasProperty)
diff --git a/src/qml/qml/ftw/qqmlthread_impl.cpp b/src/qml/qml/ftw/qqmlthread_impl.cpp
index 7a5e40e995..1114e71e29 100644
--- a/src/qml/qml/ftw/qqmlthread_impl.cpp
+++ b/src/qml/qml/ftw/qqmlthread_impl.cpp
@@ -224,6 +224,12 @@ bool QQmlThread::isThisThread() const
     return d->isCurrentThread();
 }
 
+bool QQmlThread::isParentThread() const
+{
+    // The thread() of the QQmlThread is its parent thread.
+    return d->thread()->isCurrentThread();
+}
+
 QThread *QQmlThread::thread() const
 {
     return const_cast<QThread *>(static_cast<const QThread *>(d));
diff --git a/src/qml/qml/ftw/qqmlthread_p.h b/src/qml/qml/ftw/qqmlthread_p.h
index 75d2efca4d..b373ee988d 100644
--- a/src/qml/qml/ftw/qqmlthread_p.h
+++ b/src/qml/qml/ftw/qqmlthread_p.h
@@ -38,6 +38,7 @@ public:
     void wait();
 
     bool isThisThread() const;
+    bool isParentThread() const;
 
     // Synchronously invoke a method in the thread
     template<typename Method, typename ...Args>
diff --git a/src/qml/qml/ftw/qqmlthread_stub.cpp b/src/qml/qml/ftw/qqmlthread_stub.cpp
index d65ebc7db6..0c30bce848 100644
--- a/src/qml/qml/ftw/qqmlthread_stub.cpp
+++ b/src/qml/qml/ftw/qqmlthread_stub.cpp
@@ -71,6 +71,11 @@ bool QQmlThread::isThisThread() const
     return d->thread()->isCurrentThread();
 }
 
+bool QQmlThread::isParentThread() const
+{
+    return d->thread()->isCurrentThread();
+}
+
 void QQmlThread::internalCallMethodInThread(Message *message)
 {
     internalCallMethodInMain(message);
diff --git a/src/qml/qml/qqml.cpp b/src/qml/qml/qqml.cpp
index c55064c600..c12e64b7ce 100644
--- a/src/qml/qml/qqml.cpp
+++ b/src/qml/qml/qqml.cpp
@@ -116,8 +116,8 @@ QQmlAttachedPropertiesFunc qmlAttachedPropertiesFunction(QObject *object,
                                                          const QMetaObject *attachedMetaObject)
 {
     QQmlEngine *engine = object ? qmlEngine(object) : nullptr;
-    return QQmlMetaType::attachedPropertiesFunc(engine ? QQmlEnginePrivate::get(engine) : nullptr,
-                                                attachedMetaObject);
+    return QQmlMetaType::attachedPropertiesFunc(
+            engine ? QQmlTypeLoader::get(engine) : nullptr, attachedMetaObject);
 }
 
 QObject *qmlAttachedPropertiesObject(QObject *object, QQmlAttachedPropertiesFunc func, bool create)
@@ -507,7 +507,7 @@ int qmlTypeId(const char *uri, int versionMajor, int versionMinor, const char *q
        Types; internal code should use QQmlMetaType API.
     */
     QQmlEngine engine;
-    QQmlTypeLoader *typeLoader = &QQmlEnginePrivate::get(&engine)->typeLoader;
+    QQmlTypeLoader *typeLoader = QQmlTypeLoader::get(&engine);
     auto loadHelper = QQml::makeRefPointer<LoadHelper>(
             typeLoader, uri, qmlName, QQmlTypeLoader::Synchronous);
     const QQmlType type = loadHelper->type();
@@ -2615,8 +2615,7 @@ bool AOTCompiledContext::loadAttachedLookup(uint index, QObject *object, void *t
     QV4::Scoped<QV4::QQmlTypeWrapper> wrapper(scope, lookup->qmlTypeLookup.qmlTypeWrapper);
     Q_ASSERT(wrapper);
     *static_cast<QObject **>(target) = qmlAttachedPropertiesObject(
-                object, wrapper->d()->type().attachedPropertiesFunction(
-                    QQmlEnginePrivate::get(qmlEngine())));
+                object, wrapper->d()->type().attachedPropertiesFunction(scope.engine->typeLoader()));
     return true;
 }
 
diff --git a/src/qml/qml/qqmlapplicationengine.cpp b/src/qml/qml/qqmlapplicationengine.cpp
index 221153b7f1..108312a859 100644
--- a/src/qml/qml/qqmlapplicationengine.cpp
+++ b/src/qml/qml/qqmlapplicationengine.cpp
@@ -15,8 +15,8 @@ using namespace Qt::Literals::StringLiterals;
 
 QT_BEGIN_NAMESPACE
 
-QQmlApplicationEnginePrivate::QQmlApplicationEnginePrivate(QQmlEngine *e)
-    : QQmlEnginePrivate(e)
+QQmlApplicationEnginePrivate::QQmlApplicationEnginePrivate()
+    : QQmlEnginePrivate()
 {
     uiLanguage = QLocale().bcp47Name();
 }
@@ -126,7 +126,7 @@ void QQmlApplicationEnginePrivate::startLoad(QAnyStringView uri, QAnyStringView
     const QQmlType type = componentPriv->loadHelperType();
 
     if (type.sourceUrl().isValid()) {
-        const auto qmlDirData = typeLoader.getQmldir(type.sourceUrl());
+        const auto qmlDirData = QQmlTypeLoader::get(q)->getQmldir(type.sourceUrl());
         const QUrl url = qmlDirData->finalUrl();
         // A QRC URL coming from a qmldir cannot contain a relative path
         Q_ASSERT(url.scheme() != "qrc"_L1 || url.path().startsWith('/'_L1));
@@ -296,7 +296,7 @@ void QQmlApplicationEnginePrivate::updateTranslationDirectory(const QUrl &url)
   order to load a QML file.
 */
 QQmlApplicationEngine::QQmlApplicationEngine(QObject *parent)
-: QQmlEngine(*(new QQmlApplicationEnginePrivate(this)), parent)
+: QQmlEngine(*(new QQmlApplicationEnginePrivate), parent)
 {
     QJSEnginePrivate::addToDebugServer(this);
 }
diff --git a/src/qml/qml/qqmlapplicationengine_p.h b/src/qml/qml/qqmlapplicationengine_p.h
index fa74de876f..45107deb43 100644
--- a/src/qml/qml/qqmlapplicationengine_p.h
+++ b/src/qml/qml/qqmlapplicationengine_p.h
@@ -28,7 +28,7 @@ class Q_QML_EXPORT QQmlApplicationEnginePrivate : public QQmlEnginePrivate
 {
     Q_DECLARE_PUBLIC(QQmlApplicationEngine)
 public:
-    QQmlApplicationEnginePrivate(QQmlEngine *e);
+    QQmlApplicationEnginePrivate();
     ~QQmlApplicationEnginePrivate();
     void ensureInitialized();
     void init();
diff --git a/src/qml/qml/qqmlbuiltinfunctions.cpp b/src/qml/qml/qqmlbuiltinfunctions.cpp
index d0a30e7113..9b2bbd8dd0 100644
--- a/src/qml/qml/qqmlbuiltinfunctions.cpp
+++ b/src/qml/qml/qqmlbuiltinfunctions.cpp
@@ -1374,7 +1374,7 @@ QObject *QtObject::createQmlObject(const QString &qml, QObject *parent, const QU
         return nullptr;
     }
 
-    QQmlRefPointer<QQmlTypeData> typeData = QQmlEnginePrivate::get(engine)->typeLoader.getType(
+    QQmlRefPointer<QQmlTypeData> typeData = v4Engine()->typeLoader()->getType(
                 qml.toUtf8(), resolvedUrl, QQmlTypeLoader::Synchronous);
 
     if (!typeData->isCompleteOrError()) {
@@ -1738,10 +1738,10 @@ QVariant QtObject::enumStringToValue(QJSValue enumType, QJSValue string)
     QQmlType type = enumWrapper->d()->type();
     int enumIndex = enumWrapper->d()->enumIndex;
     QString keyString = string.toString();
-    auto &typeLoader = QQmlEnginePrivate::get(m_engine->qmlEngine())->typeLoader;
+    auto *typeLoader = m_engine->typeLoader();
     int value = enumWrapper->d()->scoped
-            ? type.scopedEnumValue(&typeLoader, enumIndex, keyString, &ok)
-            : type.unscopedEnumValue(&typeLoader, enumIndex, keyString, &ok);
+            ? type.scopedEnumValue(typeLoader, enumIndex, keyString, &ok)
+            : type.unscopedEnumValue(typeLoader, enumIndex, keyString, &ok);
 
     if (ok)
         return value;
@@ -1773,10 +1773,10 @@ QVariant QtObject::enumValueToString(QJSValue enumType, QJSValue value)
     QQmlType type = enumWrapper->d()->type();
     int enumIndex = enumWrapper->d()->enumIndex;
     int keyValue = value.toInt();
-    auto &typeLoader = QQmlEnginePrivate::get(m_engine->qmlEngine())->typeLoader;
+    auto *typeLoader = m_engine->typeLoader();
     QString key = enumWrapper->d()->scoped
-            ? type.scopedEnumKey(&typeLoader, enumIndex, keyValue, &ok)
-            : type.unscopedEnumKey(&typeLoader, enumIndex, keyValue, &ok);
+            ? type.scopedEnumKey(typeLoader, enumIndex, keyValue, &ok)
+            : type.unscopedEnumKey(typeLoader, enumIndex, keyValue, &ok);
 
     if (ok)
         return key;
@@ -1805,11 +1805,11 @@ QVariant QtObject::enumValueToStrings(QJSValue enumType, QJSValue value)
     QQmlType type = enumWrapper->d()->type();
     int enumIndex = enumWrapper->d()->enumIndex;
     int keyValue = value.toInt();
-    auto &typeLoader = QQmlEnginePrivate::get(m_engine->qmlEngine())->typeLoader;
+    auto *typeLoader = m_engine->typeLoader();
     Scope scope(m_engine);
     QStringList keys = enumWrapper->d()->scoped
-            ? type.scopedEnumKeys(&typeLoader, enumIndex, keyValue, &ok)
-            : type.unscopedEnumKeys(&typeLoader, enumIndex, keyValue, &ok);
+            ? type.scopedEnumKeys(typeLoader, enumIndex, keyValue, &ok)
+            : type.unscopedEnumKeys(typeLoader, enumIndex, keyValue, &ok);
 
     if (ok)
         return keys;
diff --git a/src/qml/qml/qqmlcomponent.cpp b/src/qml/qml/qqmlcomponent.cpp
index 1dc73b9321..6ba59fad9e 100644
--- a/src/qml/qml/qqmlcomponent.cpp
+++ b/src/qml/qml/qqmlcomponent.cpp
@@ -467,8 +467,7 @@ QQmlComponent::~QQmlComponent()
         if (d->m_engine && !d->m_typeData->isCompleteOrError()) {
             // In this case we have to send it to the type loader thread to be dropped. It will
             // manipulate its "waiting" lists that other blobs may be using concurrently.
-            QQmlEnginePrivate::get(d->m_engine)->typeLoader.drop(
-                    QQmlDataBlob::Ptr(d->m_typeData.data()));
+            QQmlTypeLoader::get(d->m_engine)->drop(QQmlDataBlob::Ptr(d->m_typeData.data()));
         }
         d->m_typeData.reset();
     }
@@ -725,7 +724,7 @@ void QQmlComponent::setData(const QByteArray &data, const QUrl &url)
 
     d->m_url = url;
 
-    QQmlRefPointer<QQmlTypeData> typeData = QQmlEnginePrivate::get(d->m_engine)->typeLoader.getType(data, url);
+    QQmlRefPointer<QQmlTypeData> typeData = QQmlTypeLoader::get(d->m_engine)->getType(data, url);
 
     if (typeData->isCompleteOrError()) {
         d->fromTypeData(typeData);
@@ -824,8 +823,7 @@ void QQmlComponentPrivate::loadUrl(const QUrl &newUrl, QQmlComponent::Compilatio
     QQmlTypeLoader::Mode loaderMode = (mode == QQmlComponent::Asynchronous)
             ? QQmlTypeLoader::Asynchronous
             : QQmlTypeLoader::PreferSynchronous;
-    QQmlRefPointer<QQmlTypeData> data
-            = QQmlEnginePrivate::get(m_engine)->typeLoader.getType(m_url, loaderMode);
+    QQmlRefPointer<QQmlTypeData> data = QQmlTypeLoader::get(m_engine)->getType(m_url, loaderMode);
 
     if (data->isCompleteOrError()) {
         fromTypeData(data);
@@ -1420,9 +1418,8 @@ void QQmlComponentPrivate::prepareLoadFromModule(
     if (m_loadHelper)
         m_loadHelper->unregisterCallback(this);
 
-    QQmlTypeLoader *typeLoader = &QQmlEnginePrivate::get(m_engine)->typeLoader;
     // LoadHelper must be on the Heap as it derives from QQmlRefCount
-    m_loadHelper = QQml::makeRefPointer<LoadHelper>(typeLoader, uri, typeName, mode);
+    m_loadHelper = QQml::makeRefPointer<LoadHelper>(QQmlTypeLoader::get(m_engine), uri, typeName, mode);
 }
 
 void QQmlComponentPrivate::completeLoadFromModule(QAnyStringView uri, QAnyStringView typeName)
diff --git a/src/qml/qml/qqmlcontext.cpp b/src/qml/qml/qqmlcontext.cpp
index 39dacb80f4..f7d1c95292 100644
--- a/src/qml/qml/qqmlcontext.cpp
+++ b/src/qml/qml/qqmlcontext.cpp
@@ -453,8 +453,9 @@ QJSValue QQmlContext::importedScript(const QString &name) const
 {
     Q_D(const QQmlContext);
 
-    QQmlTypeNameCache::Result r = d->m_data->imports()->query(name, QQmlTypeLoader::get(engine()));
-    QV4::Scope scope(engine()->handle());
+    QV4::ExecutionEngine *v4 = engine()->handle();
+    QQmlTypeNameCache::Result r = d->m_data->imports()->query(name, v4->typeLoader());
+    QV4::Scope scope(v4);
     QV4::ScopedObject scripts(scope, d->m_data->importedScripts());
     return scripts ? QJSValuePrivate::fromReturnedValue(scripts->get(r.scriptIndex))
                    : QJSValue(QJSValue::UndefinedValue);
diff --git a/src/qml/qml/qqmlcustomparser.cpp b/src/qml/qml/qqmlcustomparser.cpp
index c16d4911ae..6eddb07b41 100644
--- a/src/qml/qml/qqmlcustomparser.cpp
+++ b/src/qml/qml/qqmlcustomparser.cpp
@@ -221,7 +221,7 @@ QQmlTypeLoader *QQmlCustomParser::typeLoader() const
     if (!engine && !validator)
         return nullptr;
 
-    return validator ? validator->typeLoader() : &engine->typeLoader;
+    return validator ? validator->typeLoader() : QQmlTypeLoader::get(engine);
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmldatablob_p.h b/src/qml/qml/qqmldatablob_p.h
index 8874c2c395..82e430eb2d 100644
--- a/src/qml/qml/qqmldatablob_p.h
+++ b/src/qml/qml/qqmldatablob_p.h
@@ -60,6 +60,7 @@ public:
     void startLoading();
 
     QQmlTypeLoader *typeLoader() const { return m_typeLoader; }
+    void resetTypeLoader() { m_typeLoader = nullptr; }
 
     Type type() const;
 
@@ -116,10 +117,17 @@ public:
     }
 
     template<typename Loader = QQmlTypeLoader>
+    void assertEngineThreadIfRunning() const
+    {
+        const Loader *loader = m_typeLoader;
+        Q_ASSERT(!loader || !loader->thread() || loader->thread()->isParentThread());
+    }
+
+    template<typename Loader = QQmlTypeLoader>
     void assertEngineThread() const
     {
         const Loader *loader = m_typeLoader;
-        Q_ASSERT(loader && loader->engine() && loader->engine()->thread()->isCurrentThread());
+        Q_ASSERT(loader && loader->thread() && loader->thread()->isParentThread());
     }
 
 protected:
diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index cc13b5006d..f4c3cfb1f2 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -509,7 +509,7 @@ void QQmlEnginePrivate::init()
   Create a new QQmlEngine with the given \a parent.
 */
 QQmlEngine::QQmlEngine(QObject *parent)
-: QJSEngine(*new QQmlEnginePrivate(this), parent)
+: QJSEngine(*new QQmlEnginePrivate, parent)
 {
     Q_D(QQmlEngine);
     d->init();
@@ -538,7 +538,15 @@ QQmlEngine::QQmlEngine(QQmlEnginePrivate &dd, QObject *parent)
 QQmlEngine::~QQmlEngine()
 {
     Q_D(QQmlEngine);
-    handle()->inShutdown = true;
+
+#if QT_CONFIG(qml_worker_script)
+    // Delete the workerscript engine early
+    // so that it won't be able to use the type loader anymore.
+    delete std::exchange(d->workerScriptEngine, nullptr);
+#endif
+
+    QV4::ExecutionEngine *v4 = handle();
+    v4->inShutdown = true;
     QJSEnginePrivate::removeFromDebugServer(this);
 
     // Emit onDestruction signals for the root context before
@@ -555,7 +563,7 @@ QQmlEngine::~QQmlEngine()
     delete d->rootContext;
     d->rootContext = nullptr;
 
-    d->typeLoader.invalidate();
+    v4->typeLoader()->invalidate();
 
     // QQmlGadgetPtrWrapper can have QQmlData with various references.
     qDeleteAll(d->cachedValueTypeInstances);
@@ -612,8 +620,6 @@ QQmlEngine::~QQmlEngine()
  */
 void QQmlEngine::clearComponentCache()
 {
-    Q_D(QQmlEngine);
-
     // Contexts can hold on to CUs but live on the JS heap.
     // Use a non-incremental GC run to get rid of those.
     QV4::MemoryManager *mm = handle()->memoryManager;
@@ -622,8 +628,9 @@ void QQmlEngine::clearComponentCache()
     mm->runGC();
     mm->gcStateMachine->timeLimit = std::move(oldLimit);
 
-    handle()->trimCompilationUnits();
-    d->typeLoader.clearCache();
+    QV4::ExecutionEngine *v4 = handle();
+    v4->trimCompilationUnits();
+    v4->typeLoader()->clearCache();
     QQmlMetaType::freeUnusedTypesAndCaches();
 }
 
@@ -641,9 +648,9 @@ void QQmlEngine::clearComponentCache()
  */
 void QQmlEngine::trimComponentCache()
 {
-    Q_D(QQmlEngine);
-    handle()->trimCompilationUnits();
-    d->typeLoader.trimCache();
+    QV4::ExecutionEngine *v4 = handle();
+    v4->trimCompilationUnits();
+    v4->typeLoader()->trimCache();
 }
 
 /*!
@@ -695,8 +702,7 @@ QQmlContext *QQmlEngine::rootContext() const
 */
 QQmlAbstractUrlInterceptor *QQmlEngine::urlInterceptor() const
 {
-    Q_D(const QQmlEngine);
-    return d->typeLoader.urlInterceptors().last();
+    return QQmlTypeLoader::get(this)->urlInterceptors().last();
 }
 #endif
 
@@ -711,8 +717,7 @@ QQmlAbstractUrlInterceptor *QQmlEngine::urlInterceptor() const
 */
 void QQmlEngine::addUrlInterceptor(QQmlAbstractUrlInterceptor *urlInterceptor)
 {
-    Q_D(QQmlEngine);
-    d->typeLoader.addUrlInterceptor(urlInterceptor);
+    QQmlTypeLoader::get(this)->addUrlInterceptor(urlInterceptor);
 }
 
 /*!
@@ -725,8 +730,7 @@ void QQmlEngine::addUrlInterceptor(QQmlAbstractUrlInterceptor *urlInterceptor)
 */
 void QQmlEngine::removeUrlInterceptor(QQmlAbstractUrlInterceptor *urlInterceptor)
 {
-    Q_D(QQmlEngine);
-    d->typeLoader.removeUrlInterceptor(urlInterceptor);
+    QQmlTypeLoader::get(this)->removeUrlInterceptor(urlInterceptor);
 }
 
 /*!
@@ -735,8 +739,7 @@ void QQmlEngine::removeUrlInterceptor(QQmlAbstractUrlInterceptor *urlInterceptor
  */
 QUrl QQmlEngine::interceptUrl(const QUrl &url, QQmlAbstractUrlInterceptor::DataType type) const
 {
-    Q_D(const QQmlEngine);
-    return d->typeLoader.interceptUrl(url, type);
+    return QQmlTypeLoader::get(this)->interceptUrl(url, type);
 }
 
 /*!
@@ -744,8 +747,7 @@ QUrl QQmlEngine::interceptUrl(const QUrl &url, QQmlAbstractUrlInterceptor::DataT
  */
 QList<QQmlAbstractUrlInterceptor *> QQmlEngine::urlInterceptors() const
 {
-    Q_D(const QQmlEngine);
-    return d->typeLoader.urlInterceptors();
+    return QQmlTypeLoader::get(this)->urlInterceptors();
 }
 
 QSharedPointer<QQmlImageProviderBase> QQmlEnginePrivate::imageProvider(const QString &providerId) const
@@ -770,8 +772,7 @@ QSharedPointer<QQmlImageProviderBase> QQmlEnginePrivate::imageProvider(const QSt
 */
 void QQmlEngine::setNetworkAccessManagerFactory(QQmlNetworkAccessManagerFactory *factory)
 {
-    Q_D(QQmlEngine);
-    d->typeLoader.setNetworkAccessManagerFactory(factory);
+    QQmlTypeLoader::get(this)->setNetworkAccessManagerFactory(factory);
 }
 
 class QQmlEnginePublicAPIToken {};
@@ -783,16 +784,7 @@ class QQmlEnginePublicAPIToken {};
 */
 QQmlNetworkAccessManagerFactory *QQmlEngine::networkAccessManagerFactory() const
 {
-    Q_D(const QQmlEngine);
-    return d->typeLoader.networkAccessManagerFactory().get(QQmlEnginePublicAPIToken());
-}
-
-QNetworkAccessManager *QQmlEnginePrivate::getNetworkAccessManager()
-{
-    Q_Q(QQmlEngine);
-    if (!networkAccessManager)
-        networkAccessManager = typeLoader.createNetworkAccessManager(q);
-    return networkAccessManager;
+    return QQmlTypeLoader::get(this)->networkAccessManagerFactory().get(QQmlEnginePublicAPIToken());
 }
 
 /*!
@@ -809,9 +801,7 @@ QNetworkAccessManager *QQmlEnginePrivate::getNetworkAccessManager()
 */
 QNetworkAccessManager *QQmlEngine::networkAccessManager() const
 {
-    // ### Qt7: This method is clearly not const since it _creates_ the network access manager.
-    Q_D(const QQmlEngine);
-    return const_cast<QQmlEnginePrivate *>(d)->getNetworkAccessManager();
+    return handle()->getNetworkAccessManager();
 }
 #endif // qml_network
 
@@ -1066,7 +1056,7 @@ QJSValue QQmlEngine::singletonInstance<QJSValue>(QAnyStringView uri, QAnyStringV
     Q_D(QQmlEngine);
 
     auto loadHelper = QQml::makeRefPointer<LoadHelper>(
-            &d->typeLoader, uri, typeName, QQmlTypeLoader::Synchronous);
+            QQmlTypeLoader::get(this), uri, typeName, QQmlTypeLoader::Synchronous);
     const QQmlType type = loadHelper->type();
 
     if (!type.isSingleton())
@@ -1610,8 +1600,7 @@ void QQmlEnginePrivate::cleanupScarceResources()
 */
 void QQmlEngine::addImportPath(const QString& path)
 {
-    Q_D(QQmlEngine);
-    d->typeLoader.addImportPath(path);
+    QQmlTypeLoader::get(this)->addImportPath(path);
 }
 
 /*!
@@ -1631,8 +1620,7 @@ void QQmlEngine::addImportPath(const QString& path)
 */
 QStringList QQmlEngine::importPathList() const
 {
-    Q_D(const QQmlEngine);
-    return d->typeLoader.importPathList();
+    return QQmlTypeLoader::get(this)->importPathList();
 }
 
 /*!
@@ -1649,8 +1637,7 @@ QStringList QQmlEngine::importPathList() const
   */
 void QQmlEngine::setImportPathList(const QStringList &paths)
 {
-    Q_D(QQmlEngine);
-    d->typeLoader.setImportPathList(paths);
+    QQmlTypeLoader::get(this)->setImportPathList(paths);
 }
 
 
@@ -1667,8 +1654,7 @@ void QQmlEngine::setImportPathList(const QStringList &paths)
 */
 void QQmlEngine::addPluginPath(const QString& path)
 {
-    Q_D(QQmlEngine);
-    d->typeLoader.addPluginPath(path);
+    QQmlTypeLoader::get(this)->addPluginPath(path);
 }
 
 /*!
@@ -1682,8 +1668,7 @@ void QQmlEngine::addPluginPath(const QString& path)
 */
 QStringList QQmlEngine::pluginPathList() const
 {
-    Q_D(const QQmlEngine);
-    return d->typeLoader.pluginPathList();
+    return QQmlTypeLoader::get(this)->pluginPathList();
 }
 
 /*!
@@ -1698,8 +1683,7 @@ QStringList QQmlEngine::pluginPathList() const
   */
 void QQmlEngine::setPluginPathList(const QStringList &paths)
 {
-    Q_D(QQmlEngine);
-    d->typeLoader.setPluginPathList(paths);
+    QQmlTypeLoader::get(this)->setPluginPathList(paths);
 }
 
 #if QT_CONFIG(library)
@@ -1720,9 +1704,8 @@ void QQmlEngine::setPluginPathList(const QStringList &paths)
 */
 bool QQmlEngine::importPlugin(const QString &filePath, const QString &uri, QList<QQmlError> *errors)
 {
-    Q_D(QQmlEngine);
     QQmlTypeLoaderQmldirContent qmldir;
-    QQmlPluginImporter importer(uri, QTypeRevision(),  &qmldir, &d->typeLoader, errors);
+    QQmlPluginImporter importer(uri, QTypeRevision(),  &qmldir, QQmlTypeLoader::get(this), errors);
     return importer.importDynamicPlugin(filePath, uri, false).isValid();
 }
 #endif
@@ -1907,16 +1890,6 @@ QJSValue QQmlEnginePrivate::singletonInstance<QJSValue>(const QQmlType &type)
     return value;
 }
 
-bool QQmlEnginePrivate::isTypeLoaded(const QUrl &url) const
-{
-    return typeLoader.isTypeLoaded(url);
-}
-
-bool QQmlEnginePrivate::isScriptLoaded(const QUrl &url) const
-{
-    return typeLoader.isScriptLoaded(url);
-}
-
 void QQmlEnginePrivate::executeRuntimeFunction(const QUrl &url, qsizetype functionIndex,
                                                QObject *thisObject, int argc, void **args,
                                                QMetaType *types)
@@ -1985,7 +1958,7 @@ QV4::ExecutableCompilationUnit *QQmlEnginePrivate::compilationUnitFromUrl(const
         return unit.data();
     }
 
-    auto unit = typeLoader.getType(url)->compilationUnit();
+    auto unit = v4->typeLoader()->getType(url)->compilationUnit();
     if (!unit)
         return nullptr;
 
diff --git a/src/qml/qml/qqmlengine_p.h b/src/qml/qml/qqmlengine_p.h
index 322f4d6812..4d923c983f 100644
--- a/src/qml/qml/qqmlengine_p.h
+++ b/src/qml/qml/qqmlengine_p.h
@@ -100,7 +100,6 @@ class Q_QML_EXPORT QQmlEnginePrivate : public QJSEnginePrivate
 {
     Q_DECLARE_PUBLIC(QQmlEngine)
 public:
-    explicit QQmlEnginePrivate(QQmlEngine *q) : typeLoader(q) {}
     ~QQmlEnginePrivate() override;
 
     void init();
@@ -137,10 +136,7 @@ public:
     QUrl baseUrl;
 
     QQmlObjectCreator *activeObjectCreator = nullptr;
-#if QT_CONFIG(qml_network)
-    QNetworkAccessManager *getNetworkAccessManager();
-    QNetworkAccessManager *networkAccessManager = nullptr;
-#endif
+
     mutable QRecursiveMutex imageProviderMutex;
     QHash<QString,QSharedPointer<QQmlImageProviderBase> > imageProviders;
     QSharedPointer<QQmlImageProviderBase> imageProvider(const QString &providerId) const;
@@ -149,8 +145,6 @@ public:
     void referenceScarceResources();
     void dereferenceScarceResources();
 
-    QQmlTypeLoader typeLoader;
-
     QString offlineStoragePath;
 
     // Unfortunate workaround to avoid a circular dependency between
@@ -166,9 +160,6 @@ public:
     // These methods may be called from any thread
     QString offlineStorageDatabaseDirectory() const;
 
-    bool isTypeLoaded(const QUrl &url) const;
-    bool isScriptLoaded(const QUrl &url) const;
-
     template <typename T>
     T singletonInstance(const QQmlType &type);
 
@@ -181,14 +172,15 @@ public:
     static void warning(QQmlEnginePrivate *, const QQmlError &);
     static void warning(QQmlEnginePrivate *, const QList<QQmlError> &);
 
-    inline static QV4::ExecutionEngine *getV4Engine(QQmlEngine *e);
     inline static QQmlEnginePrivate *get(QQmlEngine *e);
     inline static const QQmlEnginePrivate *get(const QQmlEngine *e);
-    inline static QQmlEnginePrivate *get(QQmlContext *c);
-    inline static QQmlEnginePrivate *get(const QQmlRefPointer<QQmlContextData> &c);
     inline static QQmlEngine *get(QQmlEnginePrivate *p);
+    inline static const QQmlEngine *get(const QQmlEnginePrivate *p);
     inline static QQmlEnginePrivate *get(QV4::ExecutionEngine *e);
 
+    inline static QQmlEnginePrivate *get(QQmlContext *c);
+    inline static QQmlEnginePrivate *get(const QQmlRefPointer<QQmlContextData> &c);
+
     static QList<QQmlError> qmlErrorFromDiagnostics(const QString &fileName, const QList<QQmlJS::DiagnosticMessage> &diagnosticMessages);
 
     static bool designerMode();
@@ -319,13 +311,6 @@ inline void QQmlEnginePrivate::dereferenceScarceResources()
     }
 }
 
-QV4::ExecutionEngine *QQmlEnginePrivate::getV4Engine(QQmlEngine *e)
-{
-    Q_ASSERT(e);
-
-    return e->handle();
-}
-
 QQmlEnginePrivate *QQmlEnginePrivate::get(QQmlEngine *e)
 {
     Q_ASSERT(e);
diff --git a/src/qml/qml/qqmlfileselector.cpp b/src/qml/qml/qqmlfileselector.cpp
index 903f67637f..4bd54fa95c 100644
--- a/src/qml/qml/qqmlfileselector.cpp
+++ b/src/qml/qml/qqmlfileselector.cpp
@@ -167,7 +167,7 @@ QQmlFileSelector* QQmlFileSelector::get(QQmlEngine* engine)
     }
 
     const QUrl nonEmptyInvalid(QLatin1String(":"));
-    const auto interceptors = enginePrivate->typeLoader.urlInterceptors();
+    const auto interceptors = QQmlTypeLoader::get(engine)->urlInterceptors();
     for (QQmlAbstractUrlInterceptor *interceptor : interceptors) {
         const QUrl result = interceptor->intercept(
                     nonEmptyInvalid, QQmlAbstractUrlInterceptor::UrlString);
diff --git a/src/qml/qml/qqmlmetatype.cpp b/src/qml/qml/qqmlmetatype.cpp
index 7491ce90e1..4a37c446e8 100644
--- a/src/qml/qml/qqmlmetatype.cpp
+++ b/src/qml/qml/qqmlmetatype.cpp
@@ -1154,13 +1154,13 @@ QMetaType QQmlMetaType::listValueType(QMetaType metaType)
         return QMetaType {};
 }
 
-QQmlAttachedPropertiesFunc QQmlMetaType::attachedPropertiesFunc(QQmlEnginePrivate *engine,
-                                                                const QMetaObject *mo)
+QQmlAttachedPropertiesFunc QQmlMetaType::attachedPropertiesFunc(
+        QQmlTypeLoader *typeLoader, const QMetaObject *mo)
 {
     QQmlMetaTypeDataPtr data;
 
     QQmlType type(data->metaObjectToType.value(mo));
-    return type.attachedPropertiesFunction(engine);
+    return type.attachedPropertiesFunction(typeLoader);
 }
 
 QMetaProperty QQmlMetaType::defaultProperty(const QMetaObject *metaObject)
diff --git a/src/qml/qml/qqmlmetatype_p.h b/src/qml/qml/qqmlmetatype_p.h
index 9e5a79630c..01ce721781 100644
--- a/src/qml/qml/qqmlmetatype_p.h
+++ b/src/qml/qml/qqmlmetatype_p.h
@@ -178,8 +178,8 @@ public:
     static QObject *toQObject(const QVariant &, bool *ok = nullptr);
 
     static QMetaType listValueType(QMetaType type);
-    static QQmlAttachedPropertiesFunc attachedPropertiesFunc(QQmlEnginePrivate *,
-                                                             const QMetaObject *);
+    static QQmlAttachedPropertiesFunc attachedPropertiesFunc(
+            QQmlTypeLoader *typeLoader, const QMetaObject *);
     static bool isInterface(QMetaType type);
     static const char *interfaceIId(QMetaType type);
     static bool isList(QMetaType type);
diff --git a/src/qml/qml/qqmlnotifyingblob.cpp b/src/qml/qml/qqmlnotifyingblob.cpp
index fc46ae942f..f3581b6b5c 100644
--- a/src/qml/qml/qqmlnotifyingblob.cpp
+++ b/src/qml/qml/qqmlnotifyingblob.cpp
@@ -19,7 +19,7 @@ void QQmlNotifyingBlob::registerCallback(Callback *callback)
 
 void QQmlNotifyingBlob::unregisterCallback(Callback *callback)
 {
-    assertEngineThread();
+    assertEngineThreadIfRunning();
     Q_ASSERT(m_callbacks.contains(callback));
     m_callbacks.removeOne(callback);
     Q_ASSERT(!m_callbacks.contains(callback));
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index 5da9c3118d..0c69d48c33 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -840,10 +840,10 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *bindingProper
         QV4::ResolvedTypeReference *tr = resolvedType(binding->propertyNameIndex);
         Q_ASSERT(tr);
         QQmlType attachedType = tr->type();
-        QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(engine);
+        QQmlTypeLoader *typeLoader = QQmlTypeLoader::get(engine);
         if (!attachedType.isValid()) {
-            QQmlTypeNameCache::Result res = context->imports()->query(
-                    stringAt(binding->propertyNameIndex), QQmlTypeLoader::get(enginePrivate));
+            QQmlTypeNameCache::Result res
+                    = context->imports()->query(stringAt(binding->propertyNameIndex), typeLoader);
             if (res.isValid())
                 attachedType = res.type;
             else
@@ -856,7 +856,7 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *bindingProper
                                 context->url()));
 
         QObject *qmlObject = qmlAttachedPropertiesObject(
-                _qobject, attachedType.attachedPropertiesFunction(enginePrivate));
+                _qobject, attachedType.attachedPropertiesFunction(typeLoader));
         if (!qmlObject) {
             recordError(binding->location,
                         QStringLiteral("Could not create attached properties object '%1'")
@@ -866,7 +866,8 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *bindingProper
 
         const size_t objectIndex = sharedState->allCreatedObjects.size();
         sharedState->allCreatedObjects.push_back(qmlObject);
-        const QQmlType attachedObjectType = QQmlMetaType::qmlType(attachedType.attachedPropertiesType(QQmlEnginePrivate::get((engine))));
+        const QQmlType attachedObjectType
+                = QQmlMetaType::qmlType(attachedType.attachedPropertiesType(typeLoader));
         const int parserStatusCast = attachedObjectType.parserStatusCast();
         QQmlParserStatus *parserStatus  = nullptr;
         if (parserStatusCast != -1)
diff --git a/src/qml/qml/qqmlproperty.cpp b/src/qml/qml/qqmlproperty.cpp
index 3fc8fac6c5..51b73bb3f6 100644
--- a/src/qml/qml/qqmlproperty.cpp
+++ b/src/qml/qml/qqmlproperty.cpp
@@ -248,12 +248,11 @@ void QQmlPropertyPrivate::initProperty(QObject *obj, const QString &name,
             // Types must begin with an uppercase letter (see checkRegistration()
             // in qqmlmetatype.cpp for the enforcement of this).
             if (typeNameCache && !pathName.isEmpty() && pathName.at(0).isUpper()) {
-                QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(engine);
-                QQmlTypeLoader *typeLoader = QQmlTypeLoader::get(enginePrivate);
+                QQmlTypeLoader *typeLoader = QQmlTypeLoader::get(engine.data());
                 QQmlTypeNameCache::Result r = typeNameCache->query(pathName, typeLoader);
                 if (r.isValid()) {
                     if (r.type.isValid()) {
-                        QQmlAttachedPropertiesFunc func = r.type.attachedPropertiesFunction(enginePrivate);
+                        QQmlAttachedPropertiesFunc func = r.type.attachedPropertiesFunction(typeLoader);
                         if (!func) return; // Not an attachable type
 
                         currentObject = qmlAttachedPropertiesObject(currentObject, func);
@@ -269,7 +268,7 @@ void QQmlPropertyPrivate::initProperty(QObject *obj, const QString &name,
                         if (!r.type.isValid())
                             return; // Invalid type in namespace
 
-                        QQmlAttachedPropertiesFunc func = r.type.attachedPropertiesFunction(enginePrivate);
+                        QQmlAttachedPropertiesFunc func = r.type.attachedPropertiesFunction(typeLoader);
                         if (!func)
                             return; // Not an attachable type
 
diff --git a/src/qml/qml/qqmltype.cpp b/src/qml/qml/qqmltype.cpp
index aa7327ffa0..89f9df7078 100644
--- a/src/qml/qml/qqmltype.cpp
+++ b/src/qml/qml/qqmltype.cpp
@@ -710,12 +710,6 @@ QTypeRevision QQmlType::metaObjectRevision() const
     return d ? d->revision : QTypeRevision();
 }
 
-QQmlAttachedPropertiesFunc QQmlType::attachedPropertiesFunction(
-        QQmlEnginePrivate *enginePrivate) const
-{
-    return attachedPropertiesFunction(&enginePrivate->typeLoader);
-}
-
 QQmlAttachedPropertiesFunc QQmlType::attachedPropertiesFunction(QQmlTypeLoader *typeLoader) const
 {
     if (const QQmlTypePrivate *base = d ? d->attachedPropertiesBase(typeLoader) : nullptr)
@@ -723,11 +717,6 @@ QQmlAttachedPropertiesFunc QQmlType::attachedPropertiesFunction(QQmlTypeLoader *
     return nullptr;
 }
 
-const QMetaObject *QQmlType::attachedPropertiesType(QQmlEnginePrivate *enginePrivate) const
-{
-    return attachedPropertiesType(&enginePrivate->typeLoader);
-}
-
 const QMetaObject *QQmlType::attachedPropertiesType(QQmlTypeLoader *typeLoader) const
 {
     if (const QQmlTypePrivate *base = d ? d->attachedPropertiesBase(typeLoader) : nullptr)
diff --git a/src/qml/qml/qqmltype_p.h b/src/qml/qml/qqmltype_p.h
index 70155637d1..c1108581b1 100644
--- a/src/qml/qml/qqmltype_p.h
+++ b/src/qml/qml/qqmltype_p.h
@@ -108,10 +108,7 @@ public:
     QTypeRevision metaObjectRevision() const;
     bool containsRevisionedAttributes() const;
 
-    QQmlAttachedPropertiesFunc attachedPropertiesFunction(QQmlEnginePrivate *enginePrivate) const;
     QQmlAttachedPropertiesFunc attachedPropertiesFunction(QQmlTypeLoader *typeLoader) const;
-
-    const QMetaObject *attachedPropertiesType(QQmlEnginePrivate *enginePrivate) const;
     const QMetaObject *attachedPropertiesType(QQmlTypeLoader *typeLoader) const;
 
     int parserStatusCast() const;
diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index a3b1e84e05..d4d711332b 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -35,8 +35,10 @@
 
 #include <functional>
 
-#define ASSERT_LOADTHREAD() Q_ASSERT(thread() && thread()->isThisThread())
-#define ASSERT_ENGINETHREAD() Q_ASSERT(engine()->thread()->isCurrentThread())
+#define ASSERT_LOADTHREAD() \
+    Q_ASSERT(thread() && thread()->isThisThread())
+#define ASSERT_ENGINETHREAD() \
+    Q_ASSERT(!engine()->jsEngine() || engine()->jsEngine()->thread()->isCurrentThread())
 
 QT_BEGIN_NAMESPACE
 
@@ -413,7 +415,7 @@ void doInitializeEngine(
     if (thread && thread->isThisThread())
         thread->initializeEngine(iface, uri);
     else
-        iface->initializeEngine(data->engine(), uri);
+        iface->initializeEngine(data->engine()->qmlEngine(), uri);
 }
 
 void QQmlTypeLoader::initializeEngine(QQmlEngineExtensionInterface *iface, const char *uri)
@@ -647,11 +649,10 @@ void QQmlTypeLoader::clearQmldirInfo()
 }
 
 static void initializeConfiguredData(
-        const QQmlTypeLoaderConfiguredDataPtr &data, QQmlEngine *engine)
+        const QQmlTypeLoaderConfiguredDataPtr &data, QV4::ExecutionEngine *engine)
 {
-    QV4::ExecutionEngine *v4 = engine->handle();
-    data->diskCacheOptions = v4->diskCacheOptions();
-    data->isDebugging = v4->debugger() != nullptr;
+    data->diskCacheOptions = engine->diskCacheOptions();
+    data->isDebugging = engine->debugger() != nullptr;
     data->initialized = true;
 }
 
@@ -1201,7 +1202,7 @@ static QStringList parseEnvPath(const QString &envImportPath)
 /*!
 Constructs a new type loader that uses the given \a engine.
 */
-QQmlTypeLoader::QQmlTypeLoader(QQmlEngine *engine)
+QQmlTypeLoader::QQmlTypeLoader(QV4::ExecutionEngine *engine)
     : m_data(engine)
 {
     QQmlTypeLoaderConfiguredDataPtr data(&m_data);
@@ -1724,6 +1725,15 @@ void QQmlTypeLoader::setQmldirContent(const QString &url, const QString &content
         qmldir->setContent(url, content);
 }
 
+template<typename Blob>
+void clearBlobs(QHash<QUrl, QQmlRefPointer<Blob>> *blobs)
+{
+    std::for_each(blobs->cbegin(), blobs->cend(), [](const QQmlRefPointer<Blob> &blob) {
+        blob->resetTypeLoader();
+    });
+    blobs->clear();
+}
+
 /*!
 Clears cached information about loaded files, including any type data, scripts
 and qmldir information.
@@ -1745,10 +1755,10 @@ void QQmlTypeLoader::clearCache()
     threadData->importQmlDirCache.clear();
 
     QQmlTypeLoaderSharedDataPtr data(&m_data);
-    data->typeCache.clear();
+    clearBlobs(&data->typeCache);
+    clearBlobs(&data->scriptCache);
+    clearBlobs(&data->qmldirCache);
     data->typeCacheTrimThreshold = QQmlTypeLoaderSharedData::MinimumTypeCacheTrimThreshold;
-    data->scriptCache.clear();
-    data->qmldirCache.clear();
     data->importDirCache.clear();
 
     // The thread will auto-restart next time we need it.
diff --git a/src/qml/qml/qqmltypeloader_p.h b/src/qml/qml/qqmltypeloader_p.h
index 757c5412bc..d207acdf34 100644
--- a/src/qml/qml/qqmltypeloader_p.h
+++ b/src/qml/qml/qqmltypeloader_p.h
@@ -129,24 +129,24 @@ public:
         QQmlMetaType::CachedUnitLookupError m_cachedUnitStatus = QQmlMetaType::CachedUnitLookupError::NoError;
     };
 
-    QQmlTypeLoader(QQmlEngine *);
+    QQmlTypeLoader(QV4::ExecutionEngine *engine);
     ~QQmlTypeLoader();
 
     template<
             typename Engine,
             typename EnginePrivate = QQmlEnginePrivate,
-            typename = std::enable_if_t<std::is_same_v<Engine, QQmlEngine>>>
+            typename = std::enable_if_t<std::is_base_of_v<QJSEngine, Engine>>>
     static QQmlTypeLoader *get(Engine *engine)
     {
-        return get(EnginePrivate::get(engine));
+        return engine->handle()->typeLoader();
     }
 
     template<
             typename Engine,
-            typename = std::enable_if_t<std::is_same_v<Engine, QQmlEnginePrivate>>>
+            typename = std::enable_if_t<std::is_base_of_v<QJSEnginePrivate, Engine>>>
     static QQmlTypeLoader *get(Engine *engine)
     {
-        return &engine->typeLoader;
+        return Engine::get(engine)->handle()->typeLoader();
     }
 
     static void sanitizeUNCPath(QString *path)
@@ -298,7 +298,7 @@ private:
     };
 
     QQmlTypeLoaderThread *thread() const { return m_data.thread(); }
-    QQmlEngine *engine() const { return m_data.engine(); }
+    QV4::ExecutionEngine *engine() const { return m_data.engine(); }
 
     void startThread();
     void shutdownThread();
diff --git a/src/qml/qml/qqmltypeloaderdata.cpp b/src/qml/qml/qqmltypeloaderdata.cpp
index 4fcece621c..6743cc4d41 100644
--- a/src/qml/qml/qqmltypeloaderdata.cpp
+++ b/src/qml/qml/qqmltypeloaderdata.cpp
@@ -10,9 +10,8 @@
 
 QT_BEGIN_NAMESPACE
 
-QQmlTypeLoaderLockedData::QQmlTypeLoaderLockedData(QQmlEngine *engine)
+QQmlTypeLoaderLockedData::QQmlTypeLoaderLockedData(QV4::ExecutionEngine *engine)
     : m_engine(engine)
-{
-}
+{}
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmltypeloaderdata_p.h b/src/qml/qml/qqmltypeloaderdata_p.h
index fa63a81003..dc2cf7f549 100644
--- a/src/qml/qml/qqmltypeloaderdata_p.h
+++ b/src/qml/qml/qqmltypeloaderdata_p.h
@@ -148,20 +148,20 @@ class QQmlTypeLoaderLockedData
 
     Q_DISABLE_COPY_MOVE(QQmlTypeLoaderLockedData)
 public:
-    QQmlTypeLoaderLockedData(QQmlEngine *engine);
+    QQmlTypeLoaderLockedData(QV4::ExecutionEngine *engine);
 
     QQmlTypeLoaderThread *thread() const { return m_thread; }
 
     void createThread(QQmlTypeLoader *loader)
     {
-        Q_ASSERT(m_engine->thread()->isCurrentThread());
+        Q_ASSERT(isCurrentJsEngineThread());
         m_thread = new QQmlTypeLoaderThread(loader);
         m_thread->startup();
     }
 
     void deleteThread()
     {
-        Q_ASSERT(m_engine->thread()->isCurrentThread());
+        Q_ASSERT(isCurrentJsEngineThread());
         Q_ASSERT(m_thread);
 
         // Shut it down first, then set it to nullptr, then delete it.
@@ -171,13 +171,23 @@ public:
         delete std::exchange(m_thread, nullptr);
     }
 
-    QQmlEngine *engine() const
+    QV4::ExecutionEngine *engine() const
     {
-        Q_ASSERT(m_engine->thread()->isCurrentThread());
+        Q_ASSERT(isCurrentJsEngineThread());
         return m_engine;
     }
 
 private:
+    bool isCurrentJsEngineThread() const
+    {
+        if (QJSEngine *jsEngine = m_engine->jsEngine())
+            return jsEngine->thread()->isCurrentThread();
+
+        // If we can't determine the thread, assume it's the right one
+        return true;
+    }
+
+
     QQmlTypeLoaderSharedData m_sharedData;
     QQmlTypeLoaderThreadData m_threadData;
     QQmlTypeLoaderConfiguredData m_configuredData;
@@ -185,7 +195,7 @@ private:
     QQmlTypeLoaderNetworkAccessManagerData m_networkAccessManagerData;
 #endif
 
-    QQmlEngine *m_engine = nullptr;
+    QV4::ExecutionEngine *m_engine = nullptr;
     QQmlTypeLoaderThread *m_thread = nullptr;
 };
 
diff --git a/src/qml/qml/qqmltypeloaderthread.cpp b/src/qml/qml/qqmltypeloaderthread.cpp
index 39a88de0c8..0fe5bf83b9 100644
--- a/src/qml/qml/qqmltypeloaderthread.cpp
+++ b/src/qml/qml/qqmltypeloaderthread.cpp
@@ -141,8 +141,8 @@ void QQmlTypeLoaderThread::initializeExtensionMain(QQmlExtensionInterface *iface
                                                 const char *uri)
 {
     // We can use m_engine because we're on the engine thread.
-    QQmlEngine *engine = m_loader->engine();
-    Q_ASSERT(engine->thread() == QThread::currentThread());
+    QQmlEngine *engine = m_loader->engine()->qmlEngine();
+    Q_ASSERT(engine && engine->thread() == QThread::currentThread());
     iface->initializeEngine(engine, uri);
 }
 
@@ -150,8 +150,8 @@ void QQmlTypeLoaderThread::initializeEngineExtensionMain(QQmlEngineExtensionInte
                                                 const char *uri)
 {
     // We can use m_engine because we're on the engine thread.
-    QQmlEngine *engine = m_loader->engine();
-    Q_ASSERT(engine->thread() == QThread::currentThread());
+    QQmlEngine *engine = m_loader->engine()->qmlEngine();
+    Q_ASSERT(engine && engine->thread() == QThread::currentThread());
     iface->initializeEngine(engine, uri);
 }
 
diff --git a/src/qml/qml/qqmltypewrapper.cpp b/src/qml/qml/qqmltypewrapper.cpp
index c56ed6e59d..826748dca1 100644
--- a/src/qml/qml/qqmltypewrapper.cpp
+++ b/src/qml/qml/qqmltypewrapper.cpp
@@ -82,12 +82,12 @@ QQmlType Heap::QQmlTypeWrapper::type() const
 }
 
 QQmlTypeNameCache::Result Heap::QQmlTypeWrapper::queryNamespace(
-        const QV4::String *name, QQmlEnginePrivate *enginePrivate) const
+        const QV4::String *name, QV4::ExecutionEngine *engine) const
 {
     Q_ASSERT(kind() == Namespace);
     Q_ASSERT(n.typeNamespace);
     Q_ASSERT(n.importNamespace);
-    return n.typeNamespace->query(name, n.importNamespace, QQmlTypeLoader::get(enginePrivate));
+    return n.typeNamespace->query(name, n.importNamespace, engine->typeLoader());
 
 }
 
@@ -155,7 +155,7 @@ const QMetaObject *QQmlTypeWrapper::metaObject() const
         return metaObjectCandidate;
     }
 
-    return type.attachedPropertiesType(QQmlEnginePrivate::get(engine()->qmlEngine()));
+    return type.attachedPropertiesType(engine()->typeLoader());
 }
 
 QObject *QQmlTypeWrapper::object() const
@@ -164,13 +164,12 @@ QObject *QQmlTypeWrapper::object() const
     if (!type.isValid())
         return nullptr;
 
-    QQmlEnginePrivate *qmlEngine = QQmlEnginePrivate::get(engine()->qmlEngine());
     if (type.isSingleton())
-        return qmlEngine->singletonInstance<QObject *>(type);
+        return QQmlEnginePrivate::get(engine()->qmlEngine())->singletonInstance<QObject *>(type);
 
     return qmlAttachedPropertiesObject(
             d()->object,
-            type.attachedPropertiesFunction(qmlEngine));
+            type.attachedPropertiesFunction(engine()->typeLoader()));
 }
 
 QObject* QQmlTypeWrapper::singletonObject() const
@@ -184,14 +183,14 @@ QObject* QQmlTypeWrapper::singletonObject() const
 
 QVariant QQmlTypeWrapper::toVariant() const
 {
-    QQmlEnginePrivate *e = QQmlEnginePrivate::get(engine()->qmlEngine());
     const QQmlType type = d()->type();
 
     if (!isSingleton()) {
         return QVariant::fromValue(qmlAttachedPropertiesObject(
-                d()->object, type.attachedPropertiesFunction(e)));
+                d()->object, type.attachedPropertiesFunction(engine()->typeLoader())));
     }
 
+    QQmlEnginePrivate *e = QQmlEnginePrivate::get(engine()->qmlEngine());
     if (type.isQJSValueSingleton())
         return QVariant::fromValue<QJSValue>(e->singletonInstance<QJSValue>(type));
 
@@ -323,15 +322,15 @@ ReturnedValue QQmlTypeWrapper::virtualGet(const Managed *m, PropertyKey id, cons
                             = w->d()->typeNameMode() == Heap::QQmlTypeWrapper::IncludeEnums;
                     if (includeEnums && name->startsWithUpper()) {
                         bool ok = false;
-                        int value = enumForSingleton(&enginePrivate->typeLoader, name, type, &ok);
+                        int value = enumForSingleton(v4->typeLoader(), name, type, &ok);
                         if (ok)
                             return QV4::Value::fromInt32(value).asReturnedValue();
 
-                        value = type.scopedEnumIndex(&enginePrivate->typeLoader, name, &ok);
+                        value = type.scopedEnumIndex(v4->typeLoader(), name, &ok);
                         if (ok)
                             return createEnumWrapper(v4, scope, type, value, true);
 
-                        value = type.unscopedEnumIndex(&enginePrivate->typeLoader, name, &ok);
+                        value = type.unscopedEnumIndex(v4->typeLoader(), name, &ok);
                         if (ok)
                             return createEnumWrapper(v4, scope, type, value, false);
                     }
@@ -362,15 +361,15 @@ ReturnedValue QQmlTypeWrapper::virtualGet(const Managed *m, PropertyKey id, cons
 
             if (name->startsWithUpper()) {
                 bool ok = false;
-                int value = type.enumValue(&enginePrivate->typeLoader, name, &ok);
+                int value = type.enumValue(v4->typeLoader(), name, &ok);
                 if (ok)
                     return QV4::Value::fromInt32(value).asReturnedValue();
 
-                value = type.scopedEnumIndex(&enginePrivate->typeLoader, name, &ok);
+                value = type.scopedEnumIndex(v4->typeLoader(), name, &ok);
                 if (ok)
                     return createEnumWrapper(v4, scope, type, value, true);
 
-                value = type.unscopedEnumIndex(&enginePrivate->typeLoader, name, &ok);
+                value = type.unscopedEnumIndex(v4->typeLoader(), name, &ok);
                 if (ok)
                     return createEnumWrapper(v4, scope, type, value, false);
 
@@ -378,8 +377,7 @@ ReturnedValue QQmlTypeWrapper::virtualGet(const Managed *m, PropertyKey id, cons
 
             } else if (w->d()->object) {
                 QObject *ao = qmlAttachedPropertiesObject(
-                        object,
-                        type.attachedPropertiesFunction(QQmlEnginePrivate::get(v4->qmlEngine())));
+                        object, type.attachedPropertiesFunction(v4->typeLoader()));
                 if (ao)
                     return QV4::QObjectWrapper::getQmlProperty(
                                 v4, context, w->d(), ao, name, QV4::QObjectWrapper::AttachMethods,
@@ -394,7 +392,7 @@ ReturnedValue QQmlTypeWrapper::virtualGet(const Managed *m, PropertyKey id, cons
         // Fall through to base implementation
 
     } else if (w->d()->kind() == Heap::QQmlTypeWrapper::Namespace) {
-        const QQmlTypeNameCache::Result r = w->d()->queryNamespace(name, enginePrivate);
+        const QQmlTypeNameCache::Result r = w->d()->queryNamespace(name, v4);
         if (r.isValid()) {
             if (r.type.isValid()) {
                 return create(scope.engine, object, r.type, w->d()->typeNameMode());
@@ -442,9 +440,8 @@ bool QQmlTypeWrapper::virtualPut(Managed *m, PropertyKey id, const Value &value,
     QQmlType type = w->d()->type();
     if (type.isValid() && !type.isSingleton() && w->d()->object) {
         QObject *object = w->d()->object;
-        QQmlEngine *e = scope.engine->qmlEngine();
         QObject *ao = qmlAttachedPropertiesObject(
-                object, type.attachedPropertiesFunction(QQmlEnginePrivate::get(e)));
+                object, type.attachedPropertiesFunction(scope.engine->typeLoader()));
         if (ao)
             return QV4::QObjectWrapper::setQmlProperty(
                         scope.engine, context, ao, name, QV4::QObjectWrapper::NoFlag, value);
@@ -521,8 +518,8 @@ static ReturnedValue instanceOfQObject(
         if (!theirDData->compilationUnit)
             return Encode(false);
 
-        QQmlEnginePrivate *qenginepriv = QQmlEnginePrivate::get(engine->qmlEngine());
-        QQmlRefPointer<QQmlTypeData> td = qenginepriv->typeLoader.getType(typeWrapper->d()->type().sourceUrl());
+        QQmlRefPointer<QQmlTypeData> td
+                = engine->typeLoader()->getType(typeWrapper->d()->type().sourceUrl());
         if (CompiledData::CompilationUnit *cu = td->compilationUnit())
             myQmlType = QQmlMetaType::metaObjectForType(cu->metaType());
         else
@@ -663,7 +660,7 @@ ReturnedValue QQmlTypeWrapper::virtualResolveLookupGetter(const Object *object,
 
         if (name->startsWithUpper()) {
             bool ok = false;
-            QQmlTypeLoader *typeLoader = &QQmlEnginePrivate::get(engine->qmlEngine())->typeLoader;
+            QQmlTypeLoader *typeLoader = engine->typeLoader();
             int value = type.enumValue(typeLoader, name, &ok);
             if (ok) {
                 lookup->qmlEnumValueLookup.ic.set(engine, This->internalClass());
@@ -698,8 +695,7 @@ ReturnedValue QQmlTypeWrapper::virtualResolveLookupGetter(const Object *object,
             // Fall through to base implementation
         } else if (w->d()->object) {
             QObject *ao = qmlAttachedPropertiesObject(
-                    w->d()->object,
-                    type.attachedPropertiesFunction(QQmlEnginePrivate::get(engine->qmlEngine())));
+                    w->d()->object, type.attachedPropertiesFunction(engine->typeLoader()));
             if (ao) {
                 // ### QTBUG-126877: Optimize this case
                 lookup->call = QV4::Lookup::Call::GetterQObjectPropertyFallback;
@@ -876,7 +872,7 @@ ReturnedValue QQmlEnumWrapper::virtualGet(const Managed *m, PropertyKey id, cons
     int index = resource->d()->enumIndex;
 
     bool ok = false;
-    auto *typeLoader = &QQmlEnginePrivate::get(v4->qmlEngine())->typeLoader;
+    auto *typeLoader = v4->typeLoader();
     int value = resource->d()->scoped ? type.scopedEnumValue(typeLoader, index, name, &ok)
                                       : type.unscopedEnumValue(typeLoader, index, name, &ok);
     if (hasProperty)
diff --git a/src/qml/qml/qqmltypewrapper_p.h b/src/qml/qml/qqmltypewrapper_p.h
index 454bcf7584..9e20be17ac 100644
--- a/src/qml/qml/qqmltypewrapper_p.h
+++ b/src/qml/qml/qqmltypewrapper_p.h
@@ -72,7 +72,7 @@ struct QQmlTypeWrapper : FunctionObject {
     void warnIfUncreatable() const;
 
     QQmlTypeNameCache::Result queryNamespace(
-            const QV4::String *name, QQmlEnginePrivate *enginePrivate) const;
+            const QV4::String *name, QV4::ExecutionEngine *engine) const;
 
     QV4QPointer<QObject> object;
 
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index d2d663bfc3..f5eb50449d 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -1670,7 +1670,8 @@ struct QQmlXMLHttpRequestCtor : public FunctionObject
         Scope scope(f->engine());
         const QQmlXMLHttpRequestCtor *ctor = static_cast<const QQmlXMLHttpRequestCtor *>(f);
 
-        QQmlXMLHttpRequest *r = new QQmlXMLHttpRequest(scope.engine->networkAccessManager(scope.engine), scope.engine);
+        QQmlXMLHttpRequest *r = new QQmlXMLHttpRequest(
+                scope.engine->getNetworkAccessManager(), scope.engine);
         Scoped<QQmlXMLHttpRequestWrapper> w(scope, scope.engine->memoryManager->allocate<QQmlXMLHttpRequestWrapper>(r));
         ScopedObject proto(scope, ctor->d()->proto);
         w->setPrototypeUnchecked(proto);
diff --git a/src/qmlmeta/types/qqmlbind.cpp b/src/qmlmeta/types/qqmlbind.cpp
index 0902778fe7..f82fb2d938 100644
--- a/src/qmlmeta/types/qqmlbind.cpp
+++ b/src/qmlmeta/types/qqmlbind.cpp
@@ -1000,8 +1000,7 @@ void QQmlBindPrivate::decodeBinding(
 
             QQmlContext *context = qmlContext(q);
             QObject *attachedObject = qmlAttachedPropertiesObject(
-                    q, attachedType.attachedPropertiesFunction(
-                               QQmlEnginePrivate::get(context->engine())));
+                    q, attachedType.attachedPropertiesFunction(QQmlTypeLoader::get(context->engine())));
             if (!attachedObject) {
                 qmlWarning(q).nospace() <<"Could not create attached properties object '"
                                         << attachedType.typeName() << "'";
diff --git a/src/qmlworkerscript/qquickworkerscript.cpp b/src/qmlworkerscript/qquickworkerscript.cpp
index dbb8281a99..14cd783c32 100644
--- a/src/qmlworkerscript/qquickworkerscript.cpp
+++ b/src/qmlworkerscript/qquickworkerscript.cpp
@@ -105,7 +105,11 @@ public:
     WorkerDestroyEvent() : QEvent(QEvent::Type(WorkerEventType::Destroy)) {}
 };
 
-struct WorkerScript : public QV4::ExecutionEngine::Deletable
+struct WorkerScript
+    : public QV4::ExecutionEngine::Deletable
+#if QT_CONFIG(qml_network)
+    , public QQmlNetworkAccessManagerFactory
+#endif
 {
     WorkerScript(QV4::ExecutionEngine *);
     ~WorkerScript() = default;
@@ -113,7 +117,7 @@ struct WorkerScript : public QV4::ExecutionEngine::Deletable
     QQuickWorkerScriptEnginePrivate *p = nullptr;
     QQuickWorkerScript *owner = nullptr;
 #if QT_CONFIG(qml_network)
-    QScopedPointer<QNetworkAccessManager> scriptLocalNAM;
+    QNetworkAccessManager *create(QObject *parent) final;
 #endif
 };
 
@@ -222,6 +226,10 @@ QV4::ExecutionEngine *QQuickWorkerScriptEnginePrivate::workerEngine(int id)
     WorkerScript *script = workerScriptExtension(engine);
     script->owner = owner;
     script->p = this;
+#if QT_CONFIG(qml_network)
+    // Eagerly create a network access manager that can outlive the parent engine.
+    engine->getNetworkAccessManager();
+#endif
     *it = engine;
     return engine;
 }
@@ -305,7 +313,7 @@ void QQuickWorkerScriptEnginePrivate::reportScriptException(WorkerScript *script
 
 QQuickWorkerScriptEngine::QQuickWorkerScriptEngine(QQmlEngine *parent)
     : QThread(parent)
-    , d(new QQuickWorkerScriptEnginePrivate(&QQmlEnginePrivate::get(parent)->typeLoader))
+    , d(new QQuickWorkerScriptEnginePrivate(QQmlTypeLoader::get(parent)))
 {
     connect(d, SIGNAL(stopThread()), this, SLOT(quit()), Qt::DirectConnection);
     QMutexLocker locker(&d->m_lock);
@@ -348,17 +356,17 @@ WorkerScript::WorkerScript(QV4::ExecutionEngine *engine)
     engine->globalObject->put(workerScriptName, api);
 
 #if QT_CONFIG(qml_network)
-    engine->networkAccessManager = [](QV4::ExecutionEngine *engine) {
-        WorkerScript *workerScript = workerScriptExtension(engine);
-        if (!workerScript->scriptLocalNAM) {
-            workerScript->scriptLocalNAM.reset(
-                    workerScript->p->m_typeLoader->createNetworkAccessManager(workerScript->p));
-        }
-        return workerScript->scriptLocalNAM.get();
-    };
+    engine->typeLoader()->setNetworkAccessManagerFactory(this);
 #endif // qml_network
 }
 
+#if QT_CONFIG(qml_network)
+QNetworkAccessManager *WorkerScript::create(QObject *parent)
+{
+    return p->m_typeLoader->createNetworkAccessManager(parent);
+}
+#endif
+
 int QQuickWorkerScriptEngine::registerWorkerScript(QQuickWorkerScript *owner)
 {
     const int id = d->m_nextId++;
diff --git a/src/quick/util/qquickpixmapcache.cpp b/src/quick/util/qquickpixmapcache.cpp
index 347e0e3936..3f412bf84a 100644
--- a/src/quick/util/qquickpixmapcache.cpp
+++ b/src/quick/util/qquickpixmapcache.cpp
@@ -443,7 +443,7 @@ QNetworkAccessManager *QQuickPixmapReader::networkAccessManager()
 {
     if (!accessManager) {
         Q_ASSERT(readerThreadExecutionEnforcer());
-        accessManager = QQmlEnginePrivate::get(engine)->typeLoader.createNetworkAccessManager(
+        accessManager = QQmlTypeLoader::get(engine)->createNetworkAccessManager(
                 readerThreadExecutionEnforcer());
     }
     return accessManager;
diff --git a/src/quicktemplates/qquickspinbox.cpp b/src/quicktemplates/qquickspinbox.cpp
index 8b8f1c4d51..ececf39883 100644
--- a/src/quicktemplates/qquickspinbox.cpp
+++ b/src/quicktemplates/qquickspinbox.cpp
@@ -432,9 +432,8 @@ QString QQuickSpinBoxPrivate::evaluateTextFromValue(int val) const
     if (engine && textFromValue.isCallable()) {
         QJSValue loc;
 #if QT_CONFIG(qml_locale)
-        QV4::ExecutionEngine *v4 = QQmlEnginePrivate::getV4Engine(engine);
         loc = QJSValuePrivate::fromReturnedValue(
-                v4->fromData(QMetaType::fromType<QLocale>(), &locale));
+                engine->handle()->fromData(QMetaType::fromType<QLocale>(), &locale));
 #endif
         text = textFromValue.call(QJSValueList() << val << loc).toString();
     } else {
@@ -451,9 +450,8 @@ int QQuickSpinBoxPrivate::evaluateValueFromText(const QString &text) const
     if (engine && valueFromText.isCallable()) {
         QJSValue loc;
 #if QT_CONFIG(qml_locale)
-        QV4::ExecutionEngine *v4 = QQmlEnginePrivate::getV4Engine(engine);
         loc = QJSValuePrivate::fromReturnedValue(
-                v4->fromData(QMetaType::fromType<QLocale>(), &locale));
+                engine->handle()->fromData(QMetaType::fromType<QLocale>(), &locale));
 #endif
         value = valueFromText.call(QJSValueList() << text << loc).toInt();
     } else {
diff --git a/src/quicktemplates/qquickstackelement.cpp b/src/quicktemplates/qquickstackelement.cpp
index 141fa1819d..04f1d92d8d 100644
--- a/src/quicktemplates/qquickstackelement.cpp
+++ b/src/quicktemplates/qquickstackelement.cpp
@@ -207,14 +207,13 @@ void QQuickStackElement::initialize(RequiredProperties *requiredProperties)
     if (!properties.isUndefined()) {
         QQmlEngine *engine = qmlEngine(view);
         Q_ASSERT(engine);
-        QV4::ExecutionEngine *v4 = QQmlEnginePrivate::getV4Engine(engine);
-        Q_ASSERT(v4);
-        QV4::Scope scope(v4);
+        QV4::Scope scope(engine->handle());
+        Q_ASSERT(scope.engine);
         QV4::ScopedValue ipv(scope, properties.value());
         QV4::Scoped<QV4::QmlContext> qmlContext(scope, qmlCallingContext.value());
-        QV4::ScopedValue qmlObject(scope, QV4::QObjectWrapper::wrap(v4, item));
+        QV4::ScopedValue qmlObject(scope, QV4::QObjectWrapper::wrap(scope.engine, item));
         QQmlComponentPrivate::setInitialProperties(
-            v4, qmlContext, qmlObject, ipv, requiredProperties, item,
+            scope.engine, qmlContext, qmlObject, ipv, requiredProperties, item,
             component ? QQmlComponentPrivate::get(component)->creator() : nullptr);
         properties.clear();
     }
diff --git a/tests/auto/qml/qqmlengine/tst_qqmlengine.cpp b/tests/auto/qml/qqmlengine/tst_qqmlengine.cpp
index 86de5c3f32..0d83f9a33c 100644
--- a/tests/auto/qml/qqmlengine/tst_qqmlengine.cpp
+++ b/tests/auto/qml/qqmlengine/tst_qqmlengine.cpp
@@ -461,12 +461,14 @@ public:
 
     Q_INVOKABLE bool isTypeLoaded(QString file)
     {
-        return QQmlEnginePrivate::get(engine)->isTypeLoaded(tst_qqmlengine::instance()->testFileUrl(file));
+        return QQmlTypeLoader::get(engine)
+                ->isTypeLoaded(tst_qqmlengine::instance()->testFileUrl(file));
     }
 
     Q_INVOKABLE bool isScriptLoaded(QString file)
     {
-        return QQmlEnginePrivate::get(engine)->isScriptLoaded(tst_qqmlengine::instance()->testFileUrl(file));
+        return QQmlTypeLoader::get(engine)
+                ->isScriptLoaded(tst_qqmlengine::instance()->testFileUrl(file));
     }
 
     Q_INVOKABLE void beginIncubation()
@@ -1113,22 +1115,22 @@ void tst_qqmlengine::componentFromEval()
 void tst_qqmlengine::qrcUrls()
 {
     QQmlEngine engine;
-    QQmlEnginePrivate *pEngine = QQmlEnginePrivate::get(&engine);
+    QQmlTypeLoader *typeLoader = QQmlTypeLoader::get(&engine);
 
     {
-        QQmlRefPointer<QQmlTypeData> oneQml(pEngine->typeLoader.getType(QUrl("qrc:/qrcurls.qml")));
+        QQmlRefPointer<QQmlTypeData> oneQml(typeLoader->getType(QUrl("qrc:/qrcurls.qml")));
         QVERIFY(oneQml.data() != nullptr);
         QVERIFY(!oneQml->backupSourceCode().isValid());
-        QQmlRefPointer<QQmlTypeData> twoQml(pEngine->typeLoader.getType(QUrl("qrc:///qrcurls.qml")));
+        QQmlRefPointer<QQmlTypeData> twoQml(typeLoader->getType(QUrl("qrc:///qrcurls.qml")));
         QVERIFY(twoQml.data() != nullptr);
         QCOMPARE(oneQml.data(), twoQml.data());
     }
 
     {
-        QQmlRefPointer<QQmlTypeData> oneJS(pEngine->typeLoader.getType(QUrl("qrc:/qrcurls.js")));
+        QQmlRefPointer<QQmlTypeData> oneJS(typeLoader->getType(QUrl("qrc:/qrcurls.js")));
         QVERIFY(oneJS.data() != nullptr);
         QVERIFY(!oneJS->backupSourceCode().isValid());
-        QQmlRefPointer<QQmlTypeData> twoJS(pEngine->typeLoader.getType(QUrl("qrc:///qrcurls.js")));
+        QQmlRefPointer<QQmlTypeData> twoJS(typeLoader->getType(QUrl("qrc:///qrcurls.js")));
         QVERIFY(twoJS.data() != nullptr);
         QCOMPARE(oneJS.data(), twoJS.data());
     }
diff --git a/tests/auto/qml/qqmlimport/tst_qqmlimport.cpp b/tests/auto/qml/qqmlimport/tst_qqmlimport.cpp
index 25275a4028..0f1956c0cd 100644
--- a/tests/auto/qml/qqmlimport/tst_qqmlimport.cpp
+++ b/tests/auto/qml/qqmlimport/tst_qqmlimport.cpp
@@ -104,7 +104,7 @@ void tst_QQmlImport::envResourceImportPath()
     qputenv("QML_IMPORT_PATH", envPaths.join(QDir::listSeparator()).toUtf8());
 
     QQmlEngine engine;
-    const QStringList importPaths = QQmlEnginePrivate::get(&engine)->typeLoader.importPathList();
+    const QStringList importPaths = QQmlTypeLoader::get(&engine)->importPathList();
 
     for (const QString &path : envPaths)
         QVERIFY((importPaths.contains(path.startsWith(u':') ? QLatin1String("qrc") + path : path)));
diff --git a/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp b/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
index b1e1a8c8db..2197a1b372 100644
--- a/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
+++ b/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
@@ -1161,7 +1161,7 @@ void tst_qqmlincubator::garbageCollection()
 
     // turn the last strong reference to the incubator into a weak one and collect
     QV4::WeakValue weakIncubatorRef;
-    weakIncubatorRef.set(QQmlEnginePrivate::getV4Engine(&engine), QJSValuePrivate::asReturnedValue(&strongRef));
+    weakIncubatorRef.set(engine.handle(), QJSValuePrivate::asReturnedValue(&strongRef));
     strongRef = QJSValue();
     incubatorVariant.clear();
 
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 09c7e75966..f8081b697e 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -2755,8 +2755,7 @@ void tst_qqmllanguage::scriptStringWithoutSourceCode()
     QUrl url = testFileUrl("scriptString7.qml");
     QScopedPointer<const QV4::CompiledData::Unit, FreeUnitData> readOnlyQmlUnit;
     {
-        QQmlEnginePrivate *eng = QQmlEnginePrivate::get(&engine);
-        QQmlRefPointer<QQmlTypeData> td = eng->typeLoader.getType(url);
+        QQmlRefPointer<QQmlTypeData> td = QQmlTypeLoader::get(&engine)->getType(url);
         Q_ASSERT(td);
         QVERIFY(!td->backupSourceCode().isValid());
 
diff --git a/tests/auto/qml/qqmlmetatype/tst_qqmlmetatype.cpp b/tests/auto/qml/qqmlmetatype/tst_qqmlmetatype.cpp
index c0fa508acf..e7356cc2b0 100644
--- a/tests/auto/qml/qqmlmetatype/tst_qqmlmetatype.cpp
+++ b/tests/auto/qml/qqmlmetatype/tst_qqmlmetatype.cpp
@@ -602,7 +602,7 @@ void tst_qqmlmetatype::unregisterAttachedProperties()
 
         const QQmlType attachedType = QQmlMetaType::qmlType("QtQuick/KeyNavigation",
                                                             QTypeRevision::fromVersion(2, 2));
-        QCOMPARE(attachedType.attachedPropertiesType(QQmlEnginePrivate::get(&e)),
+        QCOMPARE(attachedType.attachedPropertiesType(QQmlTypeLoader::get(&e)),
                  attachedType.metaObject());
 
         QScopedPointer<QObject> obj(c.create());
diff --git a/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp b/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
index 69dbd6179b..40c7b5d519 100644
--- a/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
+++ b/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
@@ -57,8 +57,8 @@ void tst_qqmltranslation::translation()
 
     if (verifyCompiledData) {
         QQmlContext *context = qmlContext(object.get());
-        QQmlEnginePrivate *engine = QQmlEnginePrivate::get(context->engine());
-        QQmlRefPointer<QQmlTypeData> typeData = engine->typeLoader.getType(context->baseUrl());
+        QQmlRefPointer<QQmlTypeData> typeData
+                = QQmlTypeLoader::get(context->engine())->getType(context->baseUrl());
         QVERIFY(!typeData->backupSourceCode().isValid());
         QV4::CompiledData::CompilationUnit *compilationUnit = typeData->compilationUnit();
         QVERIFY(compilationUnit);
@@ -122,8 +122,8 @@ void tst_qqmltranslation::idTranslation()
 
     {
         QQmlContext *context = qmlContext(object.get());
-        QQmlEnginePrivate *engine = QQmlEnginePrivate::get(context->engine());
-        QQmlRefPointer<QQmlTypeData> typeData = engine->typeLoader.getType(context->baseUrl());
+        QQmlRefPointer<QQmlTypeData> typeData
+                = QQmlTypeLoader::get(context->engine())->getType(context->baseUrl());
         QVERIFY(!typeData->backupSourceCode().isValid());
         QV4::CompiledData::CompilationUnit *compilationUnit = typeData->compilationUnit();
         QVERIFY(compilationUnit);
diff --git a/tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp b/tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp
index 02435f7cdd..995867ea9f 100644
--- a/tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp
+++ b/tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp
@@ -109,14 +109,14 @@ void tst_QQMLTypeLoader::loadComponentSynchronously()
 void tst_QQMLTypeLoader::trimCache()
 {
     QQmlEngine engine;
-    QQmlTypeLoader &loader = QQmlEnginePrivate::get(&engine)->typeLoader;
+    QQmlTypeLoader *loader = QQmlTypeLoader::get(&engine);
     QVector<QQmlTypeData *> releaseLater;
     QVector<QV4::CompiledData::CompilationUnit *> releaseCompilationUnitLater;
     for (int i = 0; i < 256; ++i) {
         QUrl url = testFileUrl("trim_cache.qml");
         url.setQuery(QString::number(i));
 
-        QQmlTypeData *data = loader.getType(url).take();
+        QQmlTypeData *data = loader->getType(url).take();
 
         // Backup source code should be dropped right after loading, even without cache trimming.
         QVERIFY(!data->backupSourceCode().isValid());
@@ -142,9 +142,9 @@ void tst_QQMLTypeLoader::trimCache()
         QUrl url = testFileUrl("trim_cache.qml");
         url.setQuery(QString::number(i));
         if (i % 5 == 0)
-            QVERIFY(loader.isTypeLoaded(url));
+            QVERIFY(loader->isTypeLoaded(url));
         else if (i < 128)
-            QVERIFY(!loader.isTypeLoaded(url));
+            QVERIFY(!loader->isTypeLoaded(url));
         // The cache is free to keep the others.
     }
 
@@ -159,13 +159,13 @@ void tst_QQMLTypeLoader::trimCache2()
 {
     QScopedPointer<QQuickView> window(new QQuickView());
     window->setSource(testFileUrl("trim_cache2.qml"));
-    QQmlTypeLoader &loader = QQmlEnginePrivate::get(window->engine())->typeLoader;
+    QQmlTypeLoader *loader = QQmlTypeLoader::get(window->engine());
     // in theory if gc has already run this could be false
     // QCOMPARE(loader.isTypeLoaded(testFileUrl("MyComponent2.qml")), true);
     window->engine()->collectGarbage();
     QTest::qWait(1);    // force event loop
     window->engine()->trimComponentCache();
-    QCOMPARE(loader.isTypeLoaded(testFileUrl("MyComponent2.qml")), false);
+    QCOMPARE(loader->isTypeLoaded(testFileUrl("MyComponent2.qml")), false);
 }
 
 // test trimming the cache of an item that contains sub-items created via incubation
@@ -173,8 +173,8 @@ void tst_QQMLTypeLoader::trimCache3()
 {
     QScopedPointer<QQuickView> window(new QQuickView());
     window->setSource(testFileUrl("trim_cache3.qml"));
-    QQmlTypeLoader &loader = QQmlEnginePrivate::get(window->engine())->typeLoader;
-    QCOMPARE(loader.isTypeLoaded(testFileUrl("ComponentWithIncubator.qml")), true);
+    QQmlTypeLoader *loader = QQmlTypeLoader::get(window->engine());
+    QCOMPARE(loader->isTypeLoaded(testFileUrl("ComponentWithIncubator.qml")), true);
 
     QQmlProperty::write(window->rootObject(), "source", QString());
 
@@ -185,7 +185,7 @@ void tst_QQMLTypeLoader::trimCache3()
 
     window->engine()->trimComponentCache();
 
-    QCOMPARE(loader.isTypeLoaded(testFileUrl("ComponentWithIncubator.qml")), false);
+    QCOMPARE(loader->isTypeLoaded(testFileUrl("ComponentWithIncubator.qml")), false);
 }
 
 void tst_QQMLTypeLoader::checkSingleton(const QString &dataDirectory)
@@ -739,8 +739,8 @@ static void getCompilationUnitAndRuntimeInfo(QQmlRefPointer<QV4::ExecutableCompi
                                              QList<int> &runtimeFunctionIndices, const QUrl &url,
                                              QQmlEngine *engine)
 {
-    QQmlTypeLoader &loader = QQmlEnginePrivate::get(engine)->typeLoader;
-    auto typeData = loader.getType(url);
+    QQmlTypeLoader *loader = QQmlTypeLoader::get(engine);
+    auto typeData = loader->getType(url);
     QVERIFY(typeData);
     QVERIFY(!typeData->backupSourceCode().isValid());
 
diff --git a/tools/qmlplugindump/main.cpp b/tools/qmlplugindump/main.cpp
index c6c96dcd90..36907a7edf 100644
--- a/tools/qmlplugindump/main.cpp
+++ b/tools/qmlplugindump/main.cpp
@@ -142,12 +142,13 @@ void collectReachableMetaObjects(QObject *object, QSet<const QMetaObject *> *met
     }
 }
 
-void collectReachableMetaObjects(QQmlEnginePrivate *engine, const QQmlType &ty, QSet<const QMetaObject *> *metas,  const QmlVersionInfo& info)
+void collectReachableMetaObjects(
+        QQmlTypeLoader *typeLoader, const QQmlType &ty, QSet<const QMetaObject *> *metas,
+        const QmlVersionInfo& info)
 {
     collectReachableMetaObjects(ty.baseMetaObject(), metas, info, ty.isExtendedType());
-    if (ty.attachedPropertiesType(engine) && matchingImportUri(ty, info)) {
-        collectReachableMetaObjects(ty.attachedPropertiesType(engine), metas, info);
-    }
+    if (ty.attachedPropertiesType(typeLoader) && matchingImportUri(ty, info))
+        collectReachableMetaObjects(ty.attachedPropertiesType(typeLoader), metas, info);
 }
 
 /* When we dump a QMetaObject, we want to list all the types it is exported as.
@@ -197,13 +198,14 @@ QByteArray convertToId(const QMetaObject *mo)
 
 
 // Collect all metaobjects for types registered with qmlRegisterType() without parameters
-void collectReachableMetaObjectsWithoutQmlName(QQmlEnginePrivate *engine, QSet<const QMetaObject *>& metas,
-                                               QMap<QString, QList<QQmlType>> &compositeTypes, const QmlVersionInfo &info) {
+void collectReachableMetaObjectsWithoutQmlName(
+        QQmlTypeLoader *typeLoader, QSet<const QMetaObject *>& metas,
+        QMap<QString, QList<QQmlType>> &compositeTypes, const QmlVersionInfo &info) {
     const auto qmlAllTypes = QQmlMetaType::qmlAllTypes();
     for (const QQmlType &ty : qmlAllTypes) {
         if (!metas.contains(ty.baseMetaObject())) {
             if (!ty.isComposite()) {
-                collectReachableMetaObjects(engine, ty, &metas, info);
+                collectReachableMetaObjects(typeLoader, ty, &metas, info);
             } else if (matchingImportUri(ty, info)) {
                 compositeTypes[ty.elementName()].append(ty);
             }
@@ -211,13 +213,10 @@ void collectReachableMetaObjectsWithoutQmlName(QQmlEnginePrivate *engine, QSet<c
     }
 }
 
-QSet<const QMetaObject *> collectReachableMetaObjects(QQmlEngine *engine,
-                                                      QSet<const QMetaObject *> &noncreatables,
-                                                      QSet<const QMetaObject *> &singletons,
-                                                      QMap<QString, QList<QQmlType>> &compositeTypes,
-                                                      const QmlVersionInfo &info,
-                                                      const QList<QQmlType> &skip = QList<QQmlType>()
-                                                      )
+QSet<const QMetaObject *> collectReachableMetaObjects(
+        QQmlEngine *engine, QSet<const QMetaObject *> &noncreatables,
+        QSet<const QMetaObject *> &singletons, QMap<QString, QList<QQmlType>> &compositeTypes,
+        const QmlVersionInfo &info, const QList<QQmlType> &skip = QList<QQmlType>())
 {
     QSet<const QMetaObject *> metas;
     metas.insert(&Qt::staticMetaObject);
@@ -233,7 +232,7 @@ QSet<const QMetaObject *> collectReachableMetaObjects(QQmlEngine *engine,
         if (!ty.isComposite()) {
             if (const QMetaObject *mo = ty.baseMetaObject())
                 qmlTypesByCppName[mo->className()].insert(ty);
-            collectReachableMetaObjects(QQmlEnginePrivate::get(engine), ty, &metas, info);
+            collectReachableMetaObjects(QQmlTypeLoader::get(engine), ty, &metas, info);
         } else {
             compositeTypes[ty.elementName()].append(ty);
         }
@@ -302,7 +301,7 @@ QSet<const QMetaObject *> collectReachableMetaObjects(QQmlEngine *engine,
         }
     }
 
-    collectReachableMetaObjectsWithoutQmlName(QQmlEnginePrivate::get(engine), metas, compositeTypes, info);
+    collectReachableMetaObjectsWithoutQmlName(QQmlTypeLoader::get(engine), metas, compositeTypes, info);
 
     return metas;
 }
@@ -535,7 +534,8 @@ public:
         QByteArray attachedTypeId;
     };
 
-    void dump(QQmlEnginePrivate *engine, const QMetaObject *meta, bool isUncreatable, bool isSingleton)
+    void dump(QQmlTypeLoader *typeLoader, const QMetaObject *meta,
+              bool isUncreatable, bool isSingleton)
     {
         qml->writeStartObject("Component");
 
@@ -548,7 +548,7 @@ public:
         for (const QQmlType &type : types) {
             const QMetaObject *extendedObject = type.extensionFunction() ? type.metaObject() : nullptr;
             QByteArray attachedTypeId;
-            if (const QMetaObject *attachedType = type.attachedPropertiesType(engine)) {
+            if (const QMetaObject *attachedType = type.attachedPropertiesType(typeLoader)) {
                 // Can happen when a type is registered that returns itself as attachedPropertiesType()
                 // because there is no creatable type to attach to.
                 if (attachedType != meta)
@@ -1355,7 +1355,8 @@ int main(int argc, char *argv[])
     if (relocatable)
         dumper.setRelocatableModuleUri(pluginImportUri);
     for (const QMetaObject *meta : std::as_const(nameToMeta)) {
-        dumper.dump(QQmlEnginePrivate::get(&engine), meta, uncreatableMetas.contains(meta), singletonMetas.contains(meta));
+        dumper.dump(QQmlTypeLoader::get(&engine), meta, uncreatableMetas.contains(meta),
+                    singletonMetas.contains(meta));
     }
 
     QMap<QString, QList<QQmlType>>::const_iterator iter = compositeTypes.constBegin();