WinUI 0.5: Unexpected C++ exceptions.

[Noemata]

Describe the bug

WinUI 3 - Project Reunion 0.5, is generating C++ exceptions for a C# managed app.

With WinUI 3 Preview 4, I was not seeing any C++ exceptions for the same project that is now migrated over to 0.5.

Repo is located here: https://github.com/Noemata/FakePOS

Steps to reproduce the bug

Steps to reproduce the behavior:

1. Run app.

Expected behavior
I was expecting the same behavior as I was seeing with WinUI 3 Preview 4.

I made the mistake of telling VS to load debug symbols. I think it may have affected my load/execution speed.

After disabling exceptions as shown below:

The exceptions are no longer thrown, but I was not seeing this before. Also, execution speed seems to be much slower now. Please advise.

Version Info

NuGet package version:
[WinUI 3 - Project Reunion 0.5 Preview: 0.5.0-prerelease]

Windows app type:

UWP	Win32
No	Yes

Windows 10 version	Saw the problem?
October 2020 Update (19042)	Yes

Device form factor	Saw the problem?
Desktop	Yes

[StephenLPeters]

@Noemata could you provide a callstack as well? :) It could be a manifestation of an issue with MRT where trying to load a resource that doesn't exist returns an error where before it was treated as okay. Tough to say without a callstack. In that case it would be a known issue (although I'm not sure its on github). @alwu-msft FYI

[Noemata]

Here's the entire call stack, right up until the exception (I am curious why you wouldn't use the repo provided):

[External Code]	

Microsoft.UI.Xaml.Controls.dll!winrt::throw_hresult(struct winrt::hresult) Unknown
Microsoft.UI.Xaml.Controls.dll!winrt::impl::consume_Microsoft_UI_Xaml_Media_IAcrylicBrushStatics::BackgroundSourceProperty(void) Unknown
Microsoft.UI.Xaml.Controls.dll!<lambda_0a1437f4f9e4e85de4e92d9eedff3a11>::<lambda_invoker_cdecl>(struct winrt::Windows::Graphics::Display::IDisplayInformationStatics const &) Unknown
Microsoft.UI.Xaml.Controls.dll!winrt::impl::factory_cache_entrywinrt::Windows::Graphics::Display::DisplayInformation,winrt::Windows::Graphics::Display::IDisplayInformationStatics::call<winrt::Windows::Graphics::Display::DisplayInformation (__cdecl*)(winrt::Windows::Graphics::Display::IDisplayInformationStatics const &)>() Unknown
Microsoft.UI.Xaml.Controls.dll!MaterialHelper::GetNoiseBrushImpl() Unknown
Microsoft.UI.Xaml.Controls.dll!MaterialHelper::GetNoiseBrush(void) Unknown
Microsoft.UI.Xaml.Controls.dll!AcrylicBrush::EnsureNoiseBrush(void) Unknown
Microsoft.UI.Xaml.Controls.dll!AcrylicBrush::CreateAcrylicBrush() Unknown
Microsoft.UI.Xaml.Controls.dll!AcrylicBrush::UpdateAcrylicBrush() Unknown
Microsoft.UI.Xaml.Controls.dll!std::_Func_impl_no_alloc<<lambda_5b13b3b6091b667131bdae3712af62d3>,void,winrt::com_ptr const &,bool>::_Do_call() Unknown
Microsoft.UI.Xaml.Controls.dll!std::_Func_class<void,struct winrt::com_ptr const &,bool>::operator()(struct winrt::com_ptr const &,bool) Unknown
Microsoft.UI.Xaml.Controls.dll!event_base<class event<class std::function >,class std::function,class std::function >::operator()<struct winrt::com_ptr,bool>(struct winrt::com_ptr const &,bool const &) Unknown
Microsoft.UI.Xaml.Controls.dll!(void)() Unknown
Microsoft.UI.Xaml.Controls.dll!MaterialHelper::UpdatePolicyStatus() Unknown
Microsoft.UI.Xaml.Controls.dll!std::_Func_impl_no_alloc<<lambda_f38bc1e85e37f8d661e19832411993ab>,void>::_Do_call() Unknown
Microsoft.UI.Xaml.Controls.dll!winrt::impl::delegate<winrt::Windows::Foundation::EventHandlerwinrt::Windows::Foundation::IInspectable,<lambda_f1ce5351e36cddf637b056ff8b430e0c>>::Invoke() Unknown
Microsoft.ui.xaml.dll!DirectUI::CEventSourceBase<DirectUI::IUntypedEventSource,ABI::Windows::Foundation::IEventHandler<IInspectable *>,IInspectable,IInspectable>::Raise() Unknown
Microsoft.ui.xaml.dll!DirectUI::DXamlCore::OnRenderingEvent() Unknown
Microsoft.ui.xaml.dll!DirectUI::DXamlCore::RaiseEvent() Unknown
Microsoft.ui.xaml.dll!CCoreServices::CallPerFrameCallback() Unknown
Microsoft.ui.xaml.dll!CCoreServices::NWDrawTree() Unknown
Microsoft.ui.xaml.dll!CCoreServices::NWDrawMainTree() Unknown
Microsoft.ui.xaml.dll!CWindowRenderTarget::Draw() Unknown
Microsoft.ui.xaml.dll!CXcpBrowserHost::OnTick() Unknown
Microsoft.ui.xaml.dll!CXcpDispatcher::Tick() Unknown
Microsoft.ui.xaml.dll!CXcpDispatcher::OnReentrancyProtectedWindowMessage() Unknown
Microsoft.ui.xaml.dll!CXcpDispatcher::ProcessMessage() Unknown
Microsoft.ui.xaml.dll!CXcpDispatcher::WindowProc() Unknown
Microsoft.ui.xaml.dll!CDeferredInvoke::DispatchQueuedMessage() Unknown
Microsoft.ui.xaml.dll!Microsoft::WRL::Details::DelegateArgTraits<long (__cdecl ABI::Windows::Foundation::ITypedEventHandler_impl<ABI::Windows::Foundation::Internal::AggregateType<ABI::Microsoft::System::DispatcherQueueTimer *,ABI::Microsoft::System::IDispatcherQueueTimer *>,IInspectable >::)(ABI::Microsoft::System::IDispatcherQueueTimer *,IInspectable *)>::DelegateInvokeHelper<Microsoft::WRL::Implements<Microsoft::WRL::RuntimeClassFlags<2>,ABI::Windows::Foundation::ITypedEventHandler<ABI::Microsoft::System::DispatcherQueueTimer *,IInspectable *>,Microsoft::WRL::FtmBase>,<lambda_fbe4f38be23425399af0724cc79ee2d3> &,1,ABI::Microsoft::System::IDispatcherQueueTimer *,IInspectable *>::Invoke() Unknown
CoreMessagingXP.dll!Microsoft::WRL::Details::DelegateArgTraits<long ( Windows::Foundation::ITypedEventHandler_impl<struct Windows::Foundation::Internal::AggregateType<class Microsoft::System::DispatcherQueueTimer *,struct Microsoft::System::IDispatcherQueueTimer *>,struct IInspectable >::)(struct Microsoft::System::IDispatcherQueueTimer *,struct IInspectable *)>::DelegateInvokeHelper<struct Microsoft::WRL::Implements<struct Microsoft::WRL::RuntimeClassFlags<2>,struct Windows::Foundation::ITypedEventHandler<class Microsoft::System::DispatcherQueueTimer *,struct IInspectable *>,class Microsoft::WRL::FtmBase>,class <lambda_67362a0a5709a7b3d634a36a54ed7d36>,-1,struct Microsoft::System::IDispatcherQueueTimer *,struct IInspectable *>::Invoke(struct Microsoft::System::IDispatcherQueueTimer *,struct IInspectable *) Unknown
CoreMessagingXP.dll!Microsoft::WRL::InvokeTraits<-2>::InvokeDelegates<class <lambda_00d64a5d69eb8cd85a8562b0747f7e4a>,struct Windows::Foundation::ITypedEventHandler<class Microsoft::System::DispatcherQueueTimer *,struct IInspectable *> >(class <lambda_00d64a5d69eb8cd85a8562b0747f7e4a>,class Microsoft::WRL::Details::EventTargetArray *,class Microsoft::WRL::EventSource<struct Windows::Foundation::ITypedEventHandler<class Microsoft::System::DispatcherQueueTimer *,struct IInspectable *>,struct Microsoft::WRL::InvokeModeOptions<-2> > *) Unknown
CoreMessagingXP.dll!Microsoft::System::DispatcherQueueTimer::TimerCallback(void ) Unknown
CoreMessagingXP.dll!CFlat::SehSafe::Execute<<lambda_654db17c35df07198786f0867aa10de6>>() Unknown
CoreMessagingXP.dll!Microsoft::CoreUI::Dispatch::TimeoutHandler::ImportAdapter$(class CFlat::Box$1<struct CFlat::FunctionPointerAndUserData$1<long ()(void *)> > *) Unknown
CoreMessagingXP.dll!Microsoft::CoreUI::Dispatch::TimeoutManager::Callback_OnDispatch(void) Unknown
CoreMessagingXP.dll!Microsoft::CoreUI::Dispatch::Dispatcher::Callback_DispatchNextItem(void) Unknown
CoreMessagingXP.dll!Microsoft::CoreUI::Dispatch::EventLoop::Callback_RunCoreLoop(enum Microsoft::CoreUI::Dispatch::RunMode) Unknown
CoreMessagingXP.dll!Microsoft::CoreUI::Dispatch::SystemCoreMessaging::Callback_OnGroupDispatch(enum Microsoft::CoreUI::Dispatch::SystemCoreMessaging$GroupPriority,struct CFlat::Ref) Unknown
CoreMessagingXP.dll!Microsoft::CoreUI::Dispatch::SystemCoreMessaging::NoContext_GroupDispatchHandler(enum Microsoft::CoreUI::Dispatch::SystemCoreMessaging$GroupPriority,void *) Unknown
CoreMessagingXP.dll!Microsoft::CoreUI::Dispatch::SystemCoreMessaging::NoContext_NormalPriorityDispatchHandler(void *) Unknown
CoreMessaging.dll!Microsoft__CoreUI__DispatchGroupHandler$CallbackThunk(class System::Delegate *) Unknown
CoreMessaging.dll!Microsoft::CoreUI::DispatchGroupHandler::Invoke() Unknown
CoreMessaging.dll!Microsoft::CoreUI::Dispatch::EventLoop::Callback_RunCoreLoop() Unknown
CoreMessaging.dll!Microsoft::CoreUI::Dispatch::UserAdapter::OnUserDispatch() Unknown
CoreMessaging.dll!Microsoft::CoreUI::Dispatch::UserAdapter_DoWork() Unknown
CoreMessaging.dll!Microsoft::CoreUI::Dispatch::UserAdapter_WindowProc() Unknown
user32.dll!UserCallWinProcCheckWow() Unknown
user32.dll!DispatchClientMessage() Unknown
user32.dll!__fnDWORD�() Unknown
ntdll.dll!KiUserCallbackDispatcherContinue�() Unknown
win32u.dll!NtUserGetMessage�() Unknown
user32.dll!GetMessageW() Unknown
Microsoft.ui.xaml.dll!DirectUI::FrameworkApplication::RunDesktopWindowMessageLoop(void) Unknown
Microsoft.ui.xaml.dll!DirectUI::FrameworkApplication::StartDesktop() Unknown
Microsoft.ui.xaml.dll!DirectUI::FrameworkApplicationFactory::Start() Unknown
[External Code]
[Inline Frame] hostpolicy.dll!coreclr_t::execute_assembly(int) Line 89 C++
hostpolicy.dll!run_app_for_context(const hostpolicy_context_t & context, int argc, const wchar_t * * argv) Line 246 C++
hostpolicy.dll!run_app(const int argc, const wchar_t * * argv) Line 275 C++
hostpolicy.dll!corehost_main(const int argc, const wchar_t * * argv) Line 408 C++
hostfxr.dll!execute_app(const std::wstring & impl_dll_dir, corehost_init_t * init, const int argc, const wchar_t * * argv) Line 146 C++
[Inline Frame] hostfxr.dll!?A0xd51c85dd::read_config_and_execute(const std::wstring &) Line 520 C++
hostfxr.dll!fx_muxer_t::handle_exec_host_command(const std::wstring & host_command, const host_startup_info_t & host_info, const std::wstring & app_candidate, const std::unordered_map<enum known_options,std::vector<std::wstring,std::allocatorstd::wstring>,known_options_hash,std::equal_to,std::allocator<std::pair<enum known_options const ,std::vector<std::wstring,std::allocatorstd::wstring>>>> & opts, int argc, const wchar_t * * argv, int argoff, host_mode_t mode, wchar_t * result_buffer, int buffer_size, int * required_buffer_size) Line 1001 C++
hostfxr.dll!fx_muxer_t::execute(const std::wstring host_command, const int argc, const wchar_t * * argv, const host_startup_info_t & host_info, wchar_t * result_buffer, int buffer_size, int * required_buffer_size) Line 566 C++
hostfxr.dll!hostfxr_main_startupinfo(const int argc, const wchar_t * * argv, const wchar_t * host_path, const wchar_t * dotnet_root, const wchar_t * app_path) Line 50 C++
FakePOS.exe!exe_start(const int argc, const wchar_t * * argv) Line 236 C++
FakePOS.exe!wmain(const int argc, const wchar_t * * argv) Line 302 C++
[External Code]

[Noemata]

Note by using this repo: https://github.com/Noemata/FakePOS

You have a direct A/B comparison between the same code in UWP (without WinUI) and WinUI desktop. 99% percent of the code is shared. I was quite impressed with WinUI 3 Preview 4 in terms of overall compatibility and its apparent momentum forward.

Things have regressed in some areas with Reunion-0.5. Ultimately, I expect all but the namespace conditional code to work in this sample!

I suggest you start lowering the bar for WinUI xx, and exceed expectations while you still can.

I've given you Microsoft's own corporate LOB sample, packaged up more correctly as a migrated app. Use it.

[riverar]

This repros on supported downlevel OSes 100%, would consider as a blocker for 3.0 GA.

[anawishnoff]

Hi @Noemata, you should see a fix for this bug in the upcoming WinUI 3/Project Reunion 0.8 Preview, which you can expect soon. Thanks for filing this!

[Noemata]

@anawishnoff , thank you.