tfjs 3.4.0 regression: wasm causes browser hang

[vladmandic]

tfjs 3.4.0 was just released and unfortunately wasm module is somewhat broken

to be precise, tfjs-backend-wasm.wasm and tfjs-backend-wasm-simd.wasm seem to work (although haven't tested in depth)
what's definitely broken is tfjs-backend-wasm-threaded-simd.wasm

and symptoms are simple - complete browser hang,
up to a point where browser window is nonresponsive to close requests and requires a hard kill

to reproduce:

• enable WebAssembly SIMD support in chrome://flags
• enable WebAssembly threads support in chrome://flags
• set backend to wasm
• run any model inference

this used to work in all recent versions of tfjs

environment: tfjs 3.4.0 on windows 10 with chrome 89 or edge 89

[rthadur]

#4796 this might be related , will try to test in my local as well and update , thank you

cc @mattsoulanille

[lina128]

I test in my local, the problem is gone after turning off the SIMD flag in chrome. We are working on a fix. Thank you for reporting the bug!

[pyu10055]

@mattsoulanille This maybe related to the recent changes to bazel wasm build, #4769

[vladmandic]

any updates on this one? as much as i'd love to use tfjs 3.4.0 due to support of tf2, this is a blocker for me.

[mattsoulanille]

No updates yet, but I've been able to reproduce it. I agree with Ping that this is likely related to changes made in #4769, and I'm taking a look.

[vladmandic]

@mattsoulanille - thanks - 'taking a look' is an update, just wanted to know what's going on as it's a blocker for me.