Handling of GPU crashes on wasm: wgpu panics on WebGL2 but continues on WebGPU

[maximetinu]

Hi !

I am experiencing inconsistent behavior between WebGL2 and WebGPU in the event of a GPU crash, and I'm unsure if it's expected

When a GPU crash occurs on wasm, wgpu apps using WebGPU keep working as usual, just without graphics, and the console logs a warning like ⚠️ GPU connection lost

However, wgpu apps using WebGL2 panic, usually by an Error in Queue::submit: Validation Error. Caused by: Not enough memory left (the actual panic depends on the reason they lost access to the GPU I presume.

Repro steps

• This can can be reproduced using any wasm examples that support both WebGL2 and WebGPU
• In Google Chrome, a GPU Crash can be simulated by writing chrome://gpucrash in the address bar (see debug section at chrome://about/ for reference)

I recorded a couple of videos showcasing this behaviour in the "Shadow" example of the repo, running on wasm with the command from the readme cargo xtask run-wasm --bin wgpu-examples ...

• WebGL2 panics
• WebGPU doesn't panic

Describe the solution you'd like
So, in other web game engines using webgl2 rendering, like Babylon.js, they can keep working without graphics after a fatal error like this happens, and they can even recover from it. That means that, if such web game engines were using wgpu and webgpu, they would not have to implement this by themselves, which is great.

In the case of Babylon.js:

this is where they got this feature request:

• WebGL lost context autorecover BabylonJS/Babylon.js#10163

and this is the PR that implemented it:

• Fix context lost/restore handling BabylonJS/Babylon.js#10173

So, my question is:

Can wgpu implement a similar resilience for WebGL2 as well, or is this behaviour an inherent limitation of lower level actors like glow or WebGL2 itself?

If the latter, feel free to close the issue as won't do. Thx! 😄

[Wumpf]

generally wgpu panics in a lot of cases today where it shouldn't and instead call into the error handlers. Some of it is hard to address but others easier so it really depends on the panic you're getting.

For the quoted error I'm a bit surprised though - I trust you installed error handlers?

[Wumpf]

Actually, now that I think of it we don't "opt into panic" on WebGPU and just let the implementation (chrome in this case) decide what happens then. Whereas on everything wgpu-core (native + webgl) we panic on errors unless an error handler is installed.

This has been around for very long now. Doubting this is a good default 🤔

[maximetinu]

For the quoted error I'm a bit surprised though - I trust you installed error handlers?

In my real app, yes I did, and I'm only logging the uncaptured errors as warnings instead of panics. It prevented most of the crashes for this reason. However, minority of them still panic because of some unwrap inside of glow

In the videos I'm posting above, I'm running the wgpu examples and they panic, do they have error handlers installed? I will try to install them, and check if that prevent the panic when GPU crashes.

[cwfitzgerald]

We need to properly hook upa default error handler that panics to match behavior.