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  1. Qt
  2. QTBUG-102025

QML WorkerScript supports only one thread

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    • Linux/X11

      The QML WorkerScript type will always reuse one thread, namely the QQmlEnginePrivate::workerScriptEngine thread (from the main/gui thread), no matter how many times the type is instantiated. This seems to be by design, though I don't really understand why. Now, either the design is wrong after all, or the documentation needs to be updated to clearly state that. From reading the documentation at least I got the impression that there's one thread per WorkerScript instance.

      Here is a very quick and dirty hack that provides the behavior that I would expect: 

      --- a/src/qmlworkerscript/qquickworkerscript.cpp
+++ b/src/qmlworkerscript/qquickworkerscript.cpp
@@ -623,10 +623,7 @@ QQuickWorkerScriptEngine *QQuickWorkerScript::engine()
             return nullptr;
         }
 
-        QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(engine);
-        if (enginePrivate->workerScriptEngine == nullptr)
-            enginePrivate->workerScriptEngine = new QQuickWorkerScriptEngine(engine);
-        m_engine = qobject_cast<QQuickWorkerScriptEngine *>(enginePrivate->workerScriptEngine);
+        m_engine = new QQuickWorkerScriptEngine(engine);
         Q_ASSERT(m_engine);
         m_scriptId = m_engine->registerWorkerScript(this);

       

        For Gerrit Dashboard: QTBUG-102025
        # Subject Branch Project Status CR V
        405968,1 WIP: Investigate impact of 1 thread (QQWSEngine) per WorkerScript dev qt/qtdeclarative Status: NEW -2 0

            qtqmlteam Qt Qml Team User
            bweimer Bernd Weimer
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              Created:
              Updated:

                There is 1 open Gerrit change