WebGPU: Return useful information in wgpuAdapterGetProperties

[austinEng]

Currently, the implementation returns empty strings in all of the vendorName, architecture, device, name, etc.. fields. It should be implemented by forwarding the fields from GPUAdapterInfo

@kainino0x

[beaufortfrancois]

I'd be happy to implement this.

FYI I naively thought it would be as simple as something like this:

   wgpuAdapterGetProperties: (adapterId, properties) => {
-    {{{ gpu.makeCheckDescriptor('properties') }}}
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.vendorID, '0', 'i32') }}};
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.vendorName, '0', 'i32') }}};
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.architecture, '0', 'i32') }}};
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.deviceID, '0', 'i32') }}};
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.name, '0', 'i32') }}};
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.driverDescription, '0', 'i32') }}};
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.adapterType, gpu.AdapterType.Unknown, 'i32') }}};
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.backendType, gpu.BackendType.WebGPU, 'i32') }}};
-    {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.compatibilityMode, '0', 'i32') }}};
+    var adapter = WebGPU.mgrAdapter.get(adapterId);
+    {{{ runtimeKeepalivePush() }}}
+    adapter["requestAdapterInfo"]().then((info) => {
+      {{{ runtimeKeepalivePop() }}}
+      {{{ gpu.makeCheckDescriptor('properties') }}}
+      {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.vendorID, '0', 'i32') }}};
+
+      var vendorNameSize = lengthBytesUTF8(info.vendor) + 1;
+      var vendorNamePtr = _malloc(vendorNameSize);
+      stringToUTF8(info.vendor, vendorNamePtr, vendorNameSize);
+
+      {{{ makeSetValue('properties', C_STRUCTS.WGPUAdapterProperties.vendorName, 'vendorNamePtr', '*') }}};
...

But it turns out it's not. @kainino0x Any idea why this code does not work? I assume it's because of the async nature of it. All the code in this file using promises have callback while this one has not.

[kainino0x]

Hm, right... I forgot that it was async in JS but sync in C.

I think to make this work we would need to have wgpuInstanceRequestAdapter actually do both requestAdapter AND requestAdapterInfo, then store off the results in case wgpuAdapterGetProperties is called later. I'm not sure if this is what we had in mind. It would work, but would make wgpuInstanceRequestAdapter slightly slower, and also would unnecessarily access fingerprintable info that the page may not actually need.

Alternatives would be:

• Make it async in C
• Somehow include in the wgpuInstanceRequestAdapter call whether you want to retrieve the properties or not

Filed https://github.com/webgpu-native/webgpu-headers/issues/266

[beaufortfrancois]

Once https://github.com/emscripten-core/emscripten/pull/22031/ is merged, I'll update wgpuAdapterGetProperties as well as it's very similar.

[beaufortfrancois]

You can follow WIP at https://github.com/beaufortfrancois/emscripten/compare/info...beaufortfrancois:emscripten:properties?expand=1

[kainino0x]

I don't think we need to fix GetProperties, we are going to remove it anyway. Better to just tell people to use the new GetInfo if they want this data - I think it's probably stable at this point.

[beaufortfrancois]

What are the next steps then? Shall we remove it from webgpu.h first, then deprecate its support in Emscripten and Dawn?

[kainino0x]

Yes, I think:

• Remove it from webgpu.h
• Optionally add a warnOnce in Emscripten (it never worked anyway though so it doesn't really matter)
• Add a deprecation warning in Dawn

[beaufortfrancois]

• Remove it from webgpu.h

I've started https://github.com/webgpu-native/webgpu-headers/pull/305

• Optionally add a warnOnce in Emscripten (it never worked anyway though so it doesn't really matter)

I've started https://github.com/emscripten-core/emscripten/pull/22088

• Add a deprecation warning in Dawn

I'll work on that then

[beaufortfrancois]

• Add a deprecation warning in Dawn

I'll work on that then

Here's the WIP CL: https://dawn-review.googlesource.com/c/dawn/+/193043

[beaufortfrancois]

I believe we can close this issue as next time we upstream changes in Emscripten, getProperties won't be there anymore according to https://github.com/emscripten-core/emscripten/issues/21552#issuecomment-2319481925 @kainino0x What do you think?

[kainino0x]

Agreed, thanks!