Asynchronous programming question in holographic app template

Yixun

Hi,
I have a question about asynchronous programming in holographic app template.
In SpinningCubeRenderer::CreateDeviceDependentResources(), the resources are loaded and created asynchronously. The variable m_loadingComplete is used to denote the resources have been loaded and created as shown below.
// Once the cube is loaded, the object is ready to be rendered.
createCubeTask.then([this] ()
{
m_loadingComplete = true;
});

However, this variable is also accessed in SpinningCubeRenderer::Update(const DX::StepTimer& timer) in the main GUI thread as follows:
// Loading is asynchronous. Resources must be created before they can be updated.
if (!m_loadingComplete)
{
return;
}

I am confused why there is no synchronization for this variable?

Thanks.

YL

AmerAmer

createCubeTask.then is a two step process. First it executes the createCubeTask on separate thread and when completed it continues to .then() lambda expression which sets the m_loadingComplete to true. Put a debug point there. You'll see it execute once the task is done.

Yixun

You mean the second task i.e. the lambda expression is executed in the rendering thread, so no need synchronization?

AmerAmer

Yes, the original thread continues.