Re: WebWorker and Device

Yes, the spec will support single device with many workers and many
canvases. The GPUDevice and other objects will be cloneable.

But we do not have any support in Chrome yet for multiple workers, and for
that matter I'm not sure if multi-canvas is tested, so we should test to
make sure we don't break it.

I'm surprised the per-device overhead is so high; I don't think it should
be. I guess we have something else to investigate there.

On Sat, Apr 18, 2020, 2:31 PM Robert Conde <jaha84@gmail.com> wrote:

> Using chrome canary, I've been playing with using multiple webgpu canvases
> in the same page. If I make a separate get adapter/device call for each
> canvas it has a very high overhead (at least on Windows the gpu process was
> 1.7 GB for 20 canvases each drawing a single triangle). Using a single
> shared device across all canvases works and greatly alleviates the
> problem.It also made initialization of each canvas significantly faster.
>
> As of now offscreen canvas support for webgpu is not implemented in chrome
> (https://bugs.chromium.org/p/chromium/issues/detail?id=1064109). However,
> I was setting up a demo just to confirm this was still broken and to have a
> test to periodically try. I found that I would get a "GPUDevice object
> could not be cloned." error trying to pass the GPUDevice to the worker. The
> GPUDevice can't be passed to transfer because it's not transferable (but
> this seemed like the wrong thing to do anyhow).
>
> So mainly what I'm trying to understand is whether sharing a single device
> instance with multiple workers is meant to be supported somehow from a
> webgpu perspective.
>
> Thanks,
> Rob Conde
>