After some further investigation I can now confirm that one of the leak
is caused by the following code in QQmlObjectCreator::createInstance(),
qqmlobjectcreator.cpp:
*sharedState->allJavaScriptObjects = QV4::QObjectWrapper::wrap(v4,
instance);
++sharedState->allJavaScriptObjects;
But the reason is still unknown
On Sun, Nov 15, 2015 at 10:19 PM, Liang Jian wrote:
> Hello everyone, I checkout qt 5.6 branch yesterday in my windows 10
> x64 machine, I build it and run my program and see many leaks. Then I use C++
> Memory Validator to find the source of the leaks, I can now confirm the
> leaked objects are QtSharedPointer::ExternalRefCountData which are created
> in QQmlObjectCreator::createInstance(), qqmlobjectcreator.cpp Line 1049,
> below is the call stack printed by C++ Memory Validator:
>
>Qt5Cored.dll QtSharedPointer::ExternalRefCountData::getAndRef :
> [d:\qt5\qtbase\src\corelib\tools\qsharedpointer.cpp Line 1337]
>
>Qt5Qmld.dll QWeakPointer::QWeakPointer :
> [d:\qt5\qtbase\src\corelib\tools\qsharedpointer_impl.h Line 706]
>
>Qt5Qmld.dll QPointer::QPointer :
> [d:\qt5\qtbase\src\corelib\kernel\qpointer.h Line 65]
>
>Qt5Qmld.dll QQmlObjectCreator::createInstance :
> [d:\qt5\qtdeclarative\src\qml\qml\qqmlobjectcreator.cpp Line 1049]
> 1044 : QQmlData *ddata = QQmlData::get(instance,
> /*create*/true);
> 1045 : ddata->rootObjectInCreation = true;
> 1046 :
> sharedState->rootContext->isRootObjectInCreation = false;
> 1047 : }
> 1048 :
> 1049 : sharedState->allCreatedObjects.push(instance);
> 1050 : } else {
> 1051 : Q_ASSERT(typeRef->component);
> 1052 : Q_QML_OC_PROFILE(sharedState->profiler,
> profiler.update(typeRef->component->fileName(),
> 1053 : context->url(), obj->location.line,
> obj->location.column));
> 1054 : if
> (typeRef->component->compilationUnit->data->isSingleton())
>Qt5Qmld.dll QQmlObjectCreator::create :
> [d:\qt5\qtdeclarative\src\qml\qml\qqmlobjectcreator.cpp Line 197]
>
>Qt5Qmld.dll QQmlComponentPrivate::beginCreate :
> [d:\qt5\qtdeclarative\src\qml\qml\qqmlcomponent.cpp Line 863]
>
>Qt5Qmld.dll QQmlComponent::beginCreate :
> [d:\qt5\qtdeclarative\src\qml\qml\qqmlcomponent.cpp Line 812]
>
>Qt5Qmld.dll QQmlComponent::create :
> [d:\qt5\qtdeclarative\src\qml\qml\qqmlcomponent.cpp Line 772]
>
>Qt5Quickd.dll QQuickView::continueExecute :
> [d:\qt5\qtdeclarative\src\quick\items\qquickview.cpp Line 486]
>
>Qt5Quickd.dll QQuickViewPrivate::execute :
> [d:\qt5\qtdeclarative\src\quick\items\qquickview.cpp Line 127]
>
>Qt5Quickd.dll QQuickView::setSource :
> [d:\qt5\qtdeclarative\src\quick\items\qquickview.cpp Line 256]
>
>
> All the leaked QtSharedPointer::ExternalRefCountData objects are
> allocated in the line
> sharedState->allCreatedObjects.push(instance);
> then some other code path will also use QPointer (contained in some
> structures allocated by v4mm) to track the same object 'instance' and I
> guess the QPointer wasn't properly destructed which will cause the
> QtSharedPointer::ExternalRefCountData
> not deleted.
> I have investigated this issue for nearly one day, but I can't find
> which code cause the leak, this is a non-trivial leak, I hope somebody can
> help to find the source of the leak. thanks!
>
>
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